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BACKGROUND OF THE INVENTION
The present invention relates generally to hair treatment aids and more particularly to protective hoods for use in rinsing the hair.
There are many processes associated with the grooming of human hair that require treating the hair with some type of liquid. Examples of such processes are applying solutions for a permanent, shampooing, and coloring. Because the types of liquids used in these processes can cause discomfort to the person requiring the treatment or can stain clothing, it is desirable to provide a means of isolating the scalp area from the face, neck and clothing of the person being treated.
The application of a permanent also requires Providing a means of retaining heat within the hair to activate the permanent solutions. In the past, a covering similar to a shower cap has been used in the application of permanent solutions to retain heat while the permanent is setting. These caps can, however, be messy and difficult to remove because they provide no means of rinsing the hair prior to removal. Furthermore, once the cap is removed, the client's head must be tilted rearward to a sink to rinse the hair. This can be difficult and uncomfortable for the client because the application of a permanent normally requires that heavy, bulky rollers be placed in the hair. The weight of these rollers and the fluid absorbed by the hair during the process can put a great strain on the client's neck if the client is required to lean backward.
There is also a need for an easy way of treating the hair of handicapped persons. Should a client be disabled or bedridden, it may be difficult or impossible to rinse the hair by having the client lean rearward toward a sink.
What is needed is a hair rinsing hood that provides protection of the facial, neck and clothing area of the client while at the same time providing for a neat and easy way of rinsing the hair without requiring the client to lean backward over a sink.
SUMMARY OF THE INVENTION
An improved hair rinsing hood according to one embodiment of the present invention comprises a flexible scalp covering including a pliable upper scalp covering portion, a pliable lower liquid directing portion sealingly connected to the upper scalp portion, an access port for the application of rinse water or other liquid, a discharge port located at the lower end of the lower liquid directing portion, and means for sealingly securing the enclosure about the head. Another feature of the present invention is a collapsible upper scalp covering portion that forms a tight fitting cap about the head.
Yet another feature of the present invention is a trailing sheet depending rearward and downward from the lower liquid directing portion for conveying liquids to a drain. A further feature of the present invention is means for opening and closing the access port thus providing rinsing access to the scalp.
It is an object of the present invention to provide an improved hair rinsing hood that may be sealingly secured about the head. Another object of the present invention is to provide a collapsible scalp covering that may be used to retain heat near the scalp.
A further object of the present invention is to provide a means of rinsing the hair which allows a client or patient to remain seated upright while the hair is rinsed. Related objects and advantages of the present invention will be apparent from the following description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front perspective view of the preferred embodiment of the hair rinsing hood incorporating the present invention.
FIG. 2 is a rear perspective view of the hood of FIG. 1.
FIG. 3 is a front perspective view of an alternate embodiment of the hair rinsing hood incorporating the present invention.
FIG. 4 is a rear perspective view of the hood of FIG. 3 depicting the invention as it appears when used as a heat barrier during the application of a hair permanent.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated device, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates.
Referring to FIGS. 1 and 2 there is shown a hair rinsing hood 10 as it would appear after the application of a permanent solution or other liquid treatment, just prior to rinsing the hair. The upper portion of hair rinsing hood 10 consists of a four part scalp covering portion 11a-11d in one specific embodiment. Parts 11a and 11c form the side walls of the scalp covering portion. Part 11b has a zipper connected thereto and is shaped to form the upper front of the scalp covering portion. Part 11d forms the remainder of the scalp covering portion and is located at the upper rear of the scalp covering portion. The four parts 11a through 11d may be stitched, glued or heat sealed together so as to form a water impermeable barrier. It should be noted that scalp covering portions 11a-11d could also consist of a single piece form fitted and contoured to the head. This portion of the hood as well as the remaining components can be manufactured of any pliable water resistant material such as vinyl or other plastic.
At the upper front of scalp covering portion 11b is an access port 12. Access port 12 can be opened or closed to allow access to the scalp 13 from the front of client. In the preferred embodiment of the invention, a zipper 13 is provided for opening and closing access port 12. Zipper 13 can be made of nylon to prevent rusting or other adverse reactions with chemicals used in the hair treatment.
The use of a zipper in this manner allows for varying the size of the opening in access port 12. The hair stylist can open the zipper, insert a rinsing nozzle, and close the zipper around the nozzle to limit the amount of overspray. It should be noted that the invention also contemplates the use of two zipper slides for the opening wherein the slides would open in opposite directions allowing for more flexibility in the location of the opening.
In an alternate embodiment of the invention shown in FIGS. 3 and 4, access port 12' is provided with an interlocking profile fastener 14 which would allow access port 12' to be opened or closed. Interlocking profile fastener 14 is comprised of male and female resilient interlocking components such as those used in resealable plastic bags. Fastener 14 can be made of plastic and can be integrally formed into or with scalp covering portion 11b. The use of such an interlocking profile fastener 14 would facilitate opening the access port at a specific location.
Scalp covering portions 11a, 11b, and 11c are sealingly connected at their outside edges to a fluid directing portion 15 by means of seams 16. These seams may be formed by heat sealing or stitching. If the seams are stitched, the use of polyester thread is recommended to avoid rotting. Likewise, polyester thread is recommended at all other areas that require stitching.
An elastic band 17 is disposed about the front pheriphery of fluid directing portion 15. The elastic band 17 provides a means of sealingly securing the enclosure about the head. In the preferred embodiment, hook and loop type fastener 18 is disposed at the front portion of the fluid directing portion 15. This adjustment mechanism allows for release of the elastic band to facilitate removal of the cap and for adjustment to fit a particular client's head.
Fluid directing portion 15 is essentially a sheet of pliable material that may be placed with one end of the sheet draping into a sink to convey rinse water runoff from the scalp area to a drain. It should be noted that rinse water could also be collected and deposited into a conduit connected to fluid directing portion 15 for conveyance into a drain.
Located at the rear of scalp covering portion 11 is a secondary access port 19 that provides rinsing access to the back portion of the client's head and scalp. Secondary access port 19 is shown in its open position in FIG. 1. Secondary access port 19 resembles the opening of a bag wherein scalp covering portions 11a-11d and fluid directing portion 15 form the sidewalls of the bag and the scalp 13 of the client forms the base. Secondary access port 19 may be closed by drawing upper scalp covering portion 11 downwardly near the rear edge. Configuring the hood in a this manner prevents rinse water spray that has entered the hood through access port 12 from being jettisoned out the rear of the hood. Also, arranging the hood in this manner causes rinse water to be deflected downwardly toward fluid directing portion 15.
An alternate embodiment of the invention is shown in FIGS. 3 and 4. The alternate embodiment has many similar features of the previously described embodiment. Such similar features are labeled as 11' for an element similar to 11, etc. In the alternate embodiment, scalp covering portion 11' is provided with pleats 20 which facilitate folding scalp covering portion 11' tightly over the scalp. Configuring the hood in this manner allows heat to be retained during the application of the permanent solution or other treatment. FIG. 4 illustrates hair rinsing hood secured in a heat retaining configuration by a second elastic elastic band 21 and a second hook and loop fastener 22. The second hook and loop fastener 22 may be released after application of the permanent solution or other treatment to allow for rinsing of the scalp in a manner similar to that described above.
The present invention is particularly useful in the application of a permanent. The client's hair is first pretreated and rolled with curlers. Next, hair rinsing hood 10 is secured about the scalp and is adjusted to form a tight seal by manipulating the hook and loop fastener 18. Hair treatment chemicals are then applied to the hair via access port 12 and secondary access port 19. Secondary access port 19 also provides the beautician with access to the scalp so that the beautician may use his or her hands to massage the scalp and fully introduce the treatment. Scalp portion 11a-11d is then folded downwardly so as to form a tight seal with the scalp and secured with secondary hook and loop fastener 22.
After the passage of a designated period of time which for the particular treatment such as may be required for setting of the permanent, secondary hook and loop fastener 22 is released and scalp covering portion 11 is moved upwardly. Access port 12 is then opened and a spray rinser 23 is used to rinse the hair treatment chemicals out of the hair near the front portion of the scalp. The rinsing fluid and the chemicals flow along the scalp toward the rear of hair rinsing hood 10 and are conveyed by fluid directing portion 15 toward a drain.
Once the front portion of the scalp is sufficiently rinsed, access port 12 is closed and secondary access port 19 is opened so as to provide access to the rear portion of the scalp. A rinsing spray is then applied to the rear portion of the scalp by way of secondary access port 19. The rinse water and hair treatment chemicals are collected near the bottom of hair rinsing hood 10 and are conveyed toward a drain via fluid directing portion 15. After the scalp is sufficiently rinsed it may be shampooed with hair rinsing hood 10 in place by using the access port 12 and secondary access port 14.
It should be noted that fluid directing portion 15 may be relatively rigid in the form of a scoop to control the flow of water. Fluid directing portion 15 may also be long enough so as that the client may remain seated upright while the hair is rinsed. The client is, therefore, subjected to much less stress and strain during the entire procedure because he or she may be able to remain seated in an upright position. It should also be noted that the entire hair rinsing hood can be formed of multiple pieces connected together or can be formed of one sheet folded over and attached with a zipper opening cut in the front.
While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiment has been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected.
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A hair rinsing hood is provided that utilizes a sealable front access port and a discharge port to facilitate the rinsing of hair after the application of a permanent, hair coloring, shampoo, etc. The hood is collapsible so that it may be drawn close to the scalp to form a tight fitting cap about the head. The hood includes a trailing sheet which extends rearwardly and downwardly from the hood for conveying liquids to a drain.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to the field of proteomic analysis, and is especially related to providing methods for matching proteins analyzed by mass spectrometry to known amino acid sequences in a database.
[0003] 2. Description of Related Art
[0004] Tandem mass spectrometry (“MS/MS”) techniques have been proven for analyzing peptides. In tandem mass spectrometry, the peptide is applied to a first mass spectrometer which serves to select, from a mixture of peptides, a target peptide of a particular mass or molecular weight. The target peptide is then activated or fragmented to produce a mixture comprising the intact peptide and various component fragments, typically peptides of smaller mass. This mixture is then applied to a second mass spectrometer which generates a fragment spectrum. This fragment spectrum will typically be expressed in the form of a bar graph having a plurality of peaks, each peak indicating the mass/charge ratio of a detected fragment.
[0005] The fragment spectrum can then be used to identify the target peptide. Previous approaches have typically involved using the fragment spectrum as a basis for hypothesizing one or more candidate amino acid sequences. This procedure has typically involved human analysis by a skilled researcher, although at least one automated procedure has been described John Yates, III, et al, Techniques In Protein Chemistry II (1991), pp. 477-485, incorporated herein by reference. The candidate sequences can then be compared with known amino acid sequences of various proteins in the protein sequence libraries.
[0006] Genome sequencing efforts have yielded a vast amount of raw DNA sequence information, which in turn has yielded a vast amount of protein sequence information. As the amount of protein sequence information increases, so does the amount of information related to their implied digest and fragmentation products.
[0007] Two circumstances have combined to make speed an important consideration in the identification of peptides through database searching with mass spectrometry fragmentation spectra.
[0008] The first circumstance is that the database of known peptides is growing rapidly. One cause of this growth in known peptides is the growth in the number of known proteins being catalogued in databases; this results in the number of their implied digest products correspondingly increasing. A second cause is that the human genome has been sequenced and many other genomes are being sequenced; these genomes likewise imply large numbers of peptides through their theoretical translation and digestion.
[0009] The second circumstance is that there are more fragmentation spectra being produced from unknown peptides. In this sort of situation, capability or capacity itself leads in turn to increased demand. The several new techniques for the automated collection of fragmentation spectra have led to the popularity of high throughput experiments with peptides.
[0010] The new techniques for the automated collection of fragmentation spectra include the capability of new MS machines for the automated selection of candidate peptides for fragmentation from the continuous input from an LC column. Another new technique is the ICAT protocol for collecting thousands of peptides from expressed genes. By combining these two techniques, approximately a thousand fragmentation spectra can be produced within a three hour run of the machine. The MALDI technique also lends itself to high throughput.
[0011] Interpretation of the fragment spectra so as to produce candidate amino acid sequences is time-consuming, often inaccurate, highly technical and in general can be performed only by a few laboratories with extensive experience in tandem mass spectrometry. Reliance on human interpretation often means that analysis is relatively slow and lacks objectivity. Approaches based on peptide mass mapping are limited to peptide masses derived from an intact homogenous protein generated by specific and known proteolytic cleavage and thus are not generally applicable to mixtures of proteins.
[0012] One impediment to high throughput protein identification by mass spectroscopy is the presence of modifications on proteins that effect their mass, leading to wasted query mass ratios and unintended hits. Methods in the prior art for addressing this problem employ the complementary y-ion to a b-ion, and vice versa, because if the modification is in the ion, it isn't in its complement, and vice versa. One unfortunate side effect of this method is that by doubling the number of query mass ratios, the noise level is also doubled. See Clauser K R, et al, Proc Natl Acad Sci USA 92: 5072-6 (1995).
[0013] There is a need for increased speed and flexibility in peptide identification, leading to increased sensitivity and selectivity, which can facilitate high-throughput peptide identification projects. These projects in turn may lead to new beneficial drug discoveries, better understanding of biological processes, and consequentially better products and methods for maintaining health and benefiting agriculture.
[0014] Furthermore, there is a need for increased sensitivity and selectivity in high-throughput identification of peptides.
[0015] Furthermore, there is a need to minimize the effect of peptide modifications on high-throughput identification of peptides.
[0016] Furthermore, when the mass of a modification is known, there is a need to employ this mass information to enhance the robustness of identification of a modified query peptide.
[0017] Finally, there is a need for enhanced speed as well as robustness when identifying query proteins containing the most common types of modifications.
BRIEF SUMMARY OF THE INVENTION
[0018] A detailed description of each of these elements and the operation of the method is provided below. All references cited herein are incorporated by reference in their entirety.
[0019] In one aspect, the invention relates to a method for comparing a query peptide to a plurality of database peptides using mass spectrometry data from the query peptide and a pre-calculated peptide index.
[0020] In another aspect, the invention relates to a method for increasing sensitivity and selectivity in the identification of peptides from their mass spectrometry fragmentation spectra by identifying the various categories of hits and optimizing a set of weights assigned to these categories.
[0021] In another aspect, the invention relates to a method for minimizing the deleterious effect of a modification of a query peptide when comparing the modified query peptide to a plurality of database peptides.
[0022] In another aspect, the invention relates to a method for employing the mass information of a known modification of a query peptide to enhance the robustness of its identification.
[0023] In another aspect, the invention relates to a method for increasing the speed of identifying a modified query peptide by comparing the modified query peptide to a plurality of database peptides augmented by a plurality of modified database peptides.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] [0024]FIG. 1 presents a flowchart illustrating the preparation of an index table in one embodiment of the invention.
[0025] [0025]FIG. 2 presents a flowchart illustrating the searching of an index table in one embodiment of the invention.
DETAILED DESCRIPTION OF INVENTION
[0026] Definitions
[0027] For the purposes of this invention, “peptide” refers to a sequence of amino acids. A “peptide database” refers to a list of peptides. A “peptide index” refers to identification information for locating a specific peptide in a peptide database. In one embodiment, a peptide index refers to an offset value from the beginning of the database.
[0028] For the purposes of this invention, an “initial string” of a peptide refers to a subsequence of the peptide beginning at the peptide's first amino acid. Similarly, a “terminal string” of a peptide refers to a subsequence of the peptide ending at the peptide's last amino acid. Both the initial string and terminal string may refer to the entire peptide.
[0029] For the purposes of this invention, when a peptide is fragmented and the charge is retained on the N-terminal cleavage fragment, the resulting ion is labelled as a “b-ion”. Similarly, if the charge is retained on the C-terminal cleavage fragment, it is labelled a “y-ion”. Masses for b-ions are calculated by summing the amino acid masses and adding the mass of a proton. Masses for y-ions are calculated by summing, from the C-terminal, the masses of the amino acids and adding the mass of water and a proton.
[0030] For the purposes of this invention, the mass of a peptide is the sum of the masses of its constituent amino acids. The set of “initial masses” of a peptide consists of the masses of all of its possible initial strings. Similarly the set of “terminal masses” of a peptide consists of the masses of all its possible terminal strings. The set of “associated masses” of a peptide consists of the union of the set of initial masses and the set of terminal masses. Except as otherwise noted, the terms “mass,” “mass ratio” and “mass/charge ratio” are used interchangeably for the purposes of this invention.
[0031] The set of “predicted mass ratios” of a peptide is the set of mass/charge values expected to result from performing a mass spectrometry measurement on a sample of the peptide.
[0032] For the purposes of this invention, the “index table” refers to a data structure whose records are indexed by discrete mass values and whose fields contain references to the associated peptides responsible for those values. The “allowed values” of an index table refers to the range of allowable values for the table's index. The “row” of an index table refers to a record, and a “column” refers to a field.
[0033] For the purposes of this invention, the “query peptide” refers to a peptide to be compared against a peptide database. A “query spectrum” is a mass spectrometry fragmentation spectrum of a sample of the query peptide comprising a plurality of mass/charge values. For the purposes of this invention, a query spectrum does not include any intensity values from the mass spectrometry data. The set of “query masses” and “query mass ratios” refers to a set of masses derived from the query spectrum. The subset of “primary query masses” and “primary query mass ratios” are those derived directly from peaks in the fragmentation spectrum. The subset of “complementary query masses” and “complementary query mass ratios” are those calculated by subtracting the primary query masses from the mass of the full query peptide.
[0034] For the purposes of this invention, a “hit” represents a peptide index located at a mass value of the index table, wherein the absolute difference between mass value and the a query mass is smaller than a predefined tolerance value.
[0035] For the purposes of this invention, a “peak mass ratio” is a query mass ratio derived by adjusting a measured mass/charge ratio for its putative isotope patterns and/or charge.
[0036] For the purposes of this invention, a “modification” is a change in the mass ratio of a peptide, either by one of its amino acids being changed, or by its N-terminal or C-terminal group being changed. An amino acid may be modified by being phosphorylated, glycosylated, or replaced with a different amino acid. The “location” of a modification is the location of the modified amino acid. For the purposes of this invention, the “spectral range” of a peptide ranges from zero to the molecular weight of the unmodified peptide.
[0037] For the purposes of this invention, the “difference mass” of a modified query peptide refers to the difference between the molecular weight of the modified query peptide and the molecular weight of the unmodified query peptide. For example, if the modification were a phosphorylation, the difference mass would be the mass of the phosphoryl group. The “modification mass ratio” refers to the mass/charge ratio of the first modified b-ion of a modified peptide.
[0038] Basic Search Method Using a Pre-calculated Index Table
[0039] The search methods of this invention require the pre-calculation of an index table. The index table is indexed by mass in discrete increments within a range of allowed values. For example, an index table could contain the values from 0.01 to 30,000 Daltons, in increments of 0.01 Dalton, resulting in a 3,000,000-row table.
[0040] Referring to FIG. 1, generation of the index table involves selecting a peptide from the peptide database (Step 100 ), calculating the set of associated masses for the peptide (Step 110 ) and for each associated mass, placing a peptide index into the row in the index table corresponding to that mass (Step 120 ). Steps 100 - 120 are then repeated for each peptide in the peptide database (Step 130 ).
[0041] Referring to FIG. 2, a search involves comparing the set of query masses against the set of all associated masses for all peptides in the peptide database. In one embodiment, a search involves generating mass spectrometry data from the query peptide (Step 200 ), identifying a peak from the spectrum and determining its mass (Step 210 ), looking up the entry in the index table corresponding to that mass (Step 220 ), and incrementing the scores of all peptides in the database having the same associated mass (Step 230 ). Steps 200 - 230 are then repeated for every peak in the spectrum (Step 240 ). Finally, those peptides with the greatest number of hits are identified.
[0042] It is possible to create an index table that is both efficient with respect to both memory and speed. In one embodiment, the index table is calculated in two passes. In the first pass, the number of entries for each row is calculated. Based on the number of entries in each row, the proper amount of memory for that row is allocated. In the second pass, the rows are populated with peptide indices referencing the peptides responsible for the associated masses corresponding to each row.
[0043] In one embodiment, a search is performed as follows: A score value is allocated and initialized for each peptide in the peptide database. For each query mass, the corresponding row in the index table is referenced, all of the peptide indices in the row are looked up, and all score values associated with those peptide indices are incremented.
[0044] A further embodiment employs a tolerance value for matching a query mass to a mass associated to a peptide in the peptide database. A query mass can hit an initial mass if the difference between the query mass and the expected N-terminal mass of the associated initial string is within a tolerance of the initial mass. Similarly, a query mass can hit an terminal mass if the difference between the query mass and the expected C-terminal mass of the associated terminal string is within a tolerance of the terminal mass. In this embodiment, a search is performed as follows: As in the previous example, a score value is allocated and initialized for each peptide in the peptide database. However in addition to referencing the row corresponding to the query mass, all neighboring rows within the specified tolerance are also referenced. In a manner similar to the previous example, all of the peptide indices in all of the referenced rows are looked up, and all score values associated with those peptide indices are incremented.
[0045] Weighted Search Method: Categories of Hits
[0046] In one embodiment, the search method employs a set of weighting factors to the various categories of peaks in the query spectrum, as experimental data indicate that some categories of peaks may yield more predictive hits than others. Peaks in the query spectrum may be categorized by several criteria. One such criterion is the type of ion which produced the peak, such as a y-ion, b-ion, a-ion, or immonium ion. Another criterion is whether the peak is a primary or complementary peak.
[0047] In mass spectrometry, a sample of a peptide is fragmented into a plurality of subfragment ions, and the mass/charge ratios of these ions are determined. Categories of subfragment ions are well known in the art, including y-ions, b-ions, a-ions, and immonium ions. For example, it has been observed that y-ions are about twice as common as b-ions in some common settings in common machines. Thus, the number of hits involving predicted y-ions should be more predictive than the number of hits involving predicted b-ions. Consequently, if the hits from those more predictive categories are weighted more heavily the ensuing query peptide identification may be more likely to be true.
[0048] In this embodiment, a set of ion types is selected. In a preferred embodiment, the set of singly-charged y-ions and b-ions is selected. Then the set of all possible subfragment ions is calculated for each peptide in the peptide database, the predicted mass/charge ratio is calculated for each subfragment ion, and the peptide index is populated according to the set of predicted mass/charge ratios as described in the section above.
[0049] In this embodiment, the query spectrum is examined for peaks corresponding to ions of the selected set of ion types. The set of query mass ratios is determined by selecting those peaks believed to correspond to the selected set of ion types.
[0050] Sometimes the mass ratio of the peak itself is a query mass ratio, as when the isotope pattern that this peak belongs to suggests that it has a single charge. When the isotope pattern suggests that the ion giving rise to the peak has a charge of 2, then its mass ratio multiplied by 2, minus the mass of hydrogen, may be used as a query mass ratio. Similarly, when the isotope pattern suggests other charges, the mass ratio of the peak is adjusted to the equivalent singly charged, mono-isotopic mass ratio before it is used as a query mass ratio.
[0051] The set of query mass ratios can be divided into primary and complementary query mass ratios. Those derived directly from the query spectrum are referred to as the set of primary query mass ratios. In one embodiment, a complementary query mass ratio C is calculated according to the following formula:
C=Q+ 2 H−P
[0052] where Q is the molecular weight of query peptide, H is the mass of hydrogen, and P is the primary query mass ratio. The set of query mass ratios comprises the union of the sets of primary and complementary mass ratios.
[0053] Determining an Optimal Set of Weights
[0054] Because the quality of data in a fragmentation spectrum can vary from peak to peak, searching a peptide database with data derived from a fragmentation spectrum often fails to produce matches with sufficient specificity and sensitivity. In one embodiment, this invention categorizes peaks from the fragmentation spectrum according to their perceived quality and assigns higher weights to higher quality peaks. For example, the quality of a peak can vary according to whether the peak represents a y-ion or a b-ion; specifically, since y-ions tend to be twice as prevalent as b-ions in common machines at common settings, it follows that the number of hits involving y-ions should be roughly twice as predictive as those of b-ions. In another example, the quality of a peak can also vary proportionally to its intensity.
[0055] In one embodiment, the weights that are assigned to each category of peak are calculated through the use of learning examples. A learning example comprises a query spectrum for which the correct peptide is known. The weights assigned to the categories are adjusted and tuned on the learning examples so that the known answer among the database peptides stands out from the crowd of possibilities most sharply.
[0056] In an illustrative example, suppose there are n peptides in the peptide database, that there are m categories of hits, that H ij is the number of hits in category j for peptide i, and that W j is the weighting value for category j. In this example, X l is the score for peptide i and is calculated as follows:
X i = ∑ j W j * H i , j
[0057] The average score, {overscore (X)}, is calculated as follows:
X _ = 1 n ∑ i X i
[0058] The population variance, σ 2 , for {overscore (X)} is calculated as follows:
σ 2 = ( 1 n ) ∑ i ( X i - X _ ) 2
[0059] In a learning sample, the query peptide is known and is present in the peptide database at position q. Let X q be the score calculated for the query peptide. Define the normal deviate, D, as follows:
D = X q - X _ σ
[0060] A desirable set of weights is one that distinguishes the score for the correct match, in this case X q , from all other scores. In this example, therefore, it is desirable to set the weights to maximize D.
[0061] In one method for determining optimal weights, a covariance value C ab is used. The value C ab represents the covariance between categories a and b, and is calculated as follows:
C a b = ( 1 n ) ∑ i ( H i a - X _ ) ( H i b - X _ )
[0062] It follows that the variance calculation described above can also be expressed in terms of the weights and the covariance:
σ 2 = ∑ a = 1 m ∑ b = 1 m W a W b C a b
[0063] Taking the derivative with respect to a specific weight value W k yields:
∂ σ 2 ∂ W k = 2 ∑ b = 1 m W b C b k
[0064] Similarly, the partial derivative of N 2 with respect to a specific weight value W k can be expressed as:
∂ N 2 ∂ W k = σ 2 2 ( X q - X _ ) ( H q k - X _ k ) - ( X q - X _ ) 2 2 ∑ a = 1 m W a C a k ( σ 2 ) 2
[0065] Setting this to zero, and simplifying by assuming that X q ≠{overscore (X)}, we get:
σ 2 ( H q k - X _ k ) = ( X q - X _ ) ∑ a = 1 m W a C a k ∑ a = 1 m W a C a k = σ 2 ( H q k - X _ k ) ( X q - X _ )
[0066] Using vector and matrix notation, and defining the vector d such that:
d
a
=H
qa
−{overscore (X)}
a
[0067] Then:
W C = ( σ 2 X q - X _ ) d W = ( σ 2 X q - X _ ) d C - 1
[0068] This equation can be solved to yield an optimal set of weights for the learning example q.
[0069] The invention uses a set of learning examples to determine a set of weights to use for subsequent unknown peptides. For each learning example, a set of optimal weights is calculated and normalized so the sum of their squares is 1. Then the average over the set of learning examples of each of these normalized weights is used in searches with new unknown peptides. A desirable set of weights are those which maximize the normal deviate.
[0070] Once a set of weights is determined, the weights are employed in assaying unknown query spectra, having the reasonable hope that they improve identification of an unknown query peptide. In one embodiment, separate index tables are created for predicted mass ratios of different ion types. In an alternate embodiment, separate index tables are created for primary and complementary mass ratios. In these embodiments, each index table has a weight associated with it. During the search, score values are incremented. The score value for each index table is then multiplied by its weight. Finally, the score values for each peptide in the peptide database are summed across index tables.
[0071] In a further embodiment, separate index tables are created for separate, orthogonal criteria. For example, separate index tables can be created according to whether the query mass ratio represents a b-ion or a y-ion, and whether query mass ratio represents a peak mass ratio or a complement mass ratio. In this example, four separate index tables are created: one for b-ions, one for y-ions, one for peak mass ratios, and one for complement mass ratios. Comparing a query peptide to these tables results in four separate counts. Each count is then multiplied by the table's corresponding weight, and all weighted counts are summed to produced a weighted score for the query protein.
[0072] Minimizing the Effect of Peptide Modifications
[0073] Many peptides contain modifications such as post-translational modifications, including phosporylation and glycosylation. Other modifications include substitution of amino acids and changes in the N-terminal or C-terminal group. Such modifications change the peptide's mass, making it difficult for that peptide to be identified through mass spectrometry. Specifically, such modifications result in some of the ions of the query peptide being chemically different from the corresponding ions of the unmodified peptide. Hence some of the query mass ratios will not match their predicted mass ratios. When the location of the modification is unknown, then it is also unknown which ions and their measured mass/charge ratios have been effected by the modification. Experimental evidence indicates that when there is a modification of an unknown query peptide, about half of the query peptide's mass ratios are observed to not correspond to a predicted mass ratio for the correct peptide. That is, about half of the query masses of a modified query peptide are not expected to distinguish the correct peptide from the other peptides. These modified query masses are not only wasted, in that they do not contribute to the score of the correct database peptide, but are actually harmful, in that they increase the scores of incorrect database peptides. In one embodiment, this invention identifies modified query masses.
[0074] The difference between the molecular weight of the modified query peptide and that of the unmodified query peptide is called the “difference mass.” If the difference mass is not known, then the modified mass ratios in the query spectrum should be excluded from comparison. In the case where the difference mass is known, that information should be used to adjust the query mass ratios, thus increasing the selectivity and sensitivity of the search. In one embodiment, the query mass ratios are adjusted by subtracting the difference mass from them.
[0075] In one embodiment, the search method identifies the modified query masses of a modified query protein by dividing the spectral range of the query peptide into intervals and performing separate searches for each interval. In a further embodiment, these modified query masses are excluded from comparison with the peptide index. In an alternate embodiment, these modified query masses are adjusted before being used for comparison with the peptide index.
[0076] The range from zero to the unmodified query peptide's mass is called the spectral range. Given the mass of a query peptide, all query mass ratios higher than the predicted mass can be ascribed to modification. In one embodiment, the spectral range is divided into intervals, and separate searches are performed over each interval.
[0077] In one embodiment, the query peptide's spectral range is divided into m equal intervals. Consider one such interval from mass j to mass k, and assume that the modification mass ratio lies in the [j,k] interval. By assuming that the modification lies in the [j,k] interval, a set of modified query mass ratios can be identified. These identified mass ratios can then be dropped from comparison if the difference mass is unknown, or adjusted if the difference mass is known. Different sets of mass ratios can be identified, for example one set can be identified by comparing to predicted b-ion mass ratios, and another set can be identified by comparing to predicted y-ion mass ratios. Specifically, all the query mass ratios greater than k are dropped or adjusted when looking for hits against predicted b-ion mass ratios; all the query mass ratios greater than molecular weight (2H−j) are dropped or adjusted when looking for hits against predicted y-ion mass ratios
[0078] In this embodiment, after the query peptide's spectral range is divided into m intervals, a separate search is performed on each interval with each search assuming that the query peptide's modification lies in that search's interval. After performing the separate searches, the scores from each search are summed up, and the peptide with the highest score over all of the searches is determined to be the best match to the query peptide.
[0079] The method of this embodiment increases the sensitivity and specificity of a modified query protein search by altering the distribution of hits in the search process. To understand the expected advantage of identifying modified query mass ratios in the search process, it is first neccessary to examine the expected distribution of hits in a normal search where one interval covers the whole modified query peptide.
[0080] Suppose a query peptide is compared to a peptide database consisting of k peptides. A histogram F can be constructed wherein F b represents the number of database peptides receiving b hits. The fraction of peptides in the database receiving b hits, D b , can be calculated thus:
D b = F b k
[0081] If the search is defined as a number of trials wherein each query mass represents a trial, and if success is defined as the query mass hitting a peptide in the peptide index, then D (and F) can be seen to follow a binomial distribution. The variance of a binomial distribution is proportional to the number of trials; specifically the variance of the binomial distribution (n,p), where n is the number of trials and p is the probability of success per trial, is np(1−p). In other words, the variance of D (and F) is proportional to the number of query mass ratios used in the search. A desirable probability density of D (and F) represents a small number of sequences receiving a high number of hits, providing a sharp contrast between a true hit and noise. The binomial distribution approaches this ideal for lower values of n, especially for small values of p. Limiting a search to a short interval reduces the number of query mass ratios, or n, which in turn leads to a more useful probability density function for D (and F).
[0082] In an illustrative example, two searches are performed and the results are used to calculate the histogram vectors H1 and H2. In this example, assuming that H1 and H2 are uncorrelated, it follows that H1 and H2 are random variables with the same density functions as F and D, above. Now assume that the first search consists of n query masses and the second search consists of 2n query masses. It follows that the variance of the H2 is twice that of H1. Therefore, because searching over a smaller interval reduces the number of query masses, interval searches have a smaller variance than searches over the entire peptide.
[0083] For larger peptide databases, that is, for increasing values of k, the difference becomes even more pronounced. Although the underlying density, D, remains constant, the raw values in the histogram F increases proportionally to k, resulting in a closer approximation to the desired binomial distribution. By dividing the peptide into m intervals and performing m searches, the size of the peptide database is effectively increased by a factor of m. Thus, the method described herein performs the dual purpose of designed a desirable probability density function for the results, as well as making the results correlate more closely to the desired function. However, an expected disadvantage to performing m searches and effectively increasing the number of peptides in the peptide database by a factor of m is that this approach also increases F by a factor of m, raising the tail of the distribution and slowing its dropoff.
[0084] When the number of intervals is small, one doesn't drop as many modified query masses as when the number of intervals is larger. But as one does more searches, the disadvantage described above increases. Experimental evidence indicates that 6 is about the optimal number of intervals to use. The location in the tail of the number of hits on the correct peptide, and the manner of decay of the tail have been estimated. Experimental evidence indicates that for m˜6, the expected advantage of eliminating modified query masses outweighs the expected disadvantages by a factor of 30. Experimental evidence further indicates that for m˜6, the expected advantage of adjusting modified query masses outweighs the expected disadvantages by a factor of 5000.
[0085] In one embodiment, the number of query masses in an interval is further reduced by identifying and eliminating modified query masses. For example, as illustrated above, if half of the query masses are eliminated, the variance of the resulting distribution is halved.
[0086] In an alternate embodiment, the modified query masses are identified and then adjusted. In a further embodiment, the modified query masses are adjusted by subtracting the known difference mass. Although the adjusted modified query masses are not eliminated from comparison, their hits to peptide database are more likely to be correct than if left unadjusted. The method of this embodiment can be seen as a way to double the number of correct hits for a modified query protein.
[0087] Although the examples herein describe analysis of a singly-modified protein, one of ordinary skill in the art can readily comprehend how the described methods can easily be extended to analyze proteins containing two or more modifications.
[0088] Adding Modifed Peptides to the Peptide Database
[0089] In one embodiment, this invention provides a method for increasing the likelihood that an unknown modified query peptide will be correctly identified by adding appropriately modified peptides to the peptide database before proceeding with the construction of the index table.
[0090] It is well established in the art that the most common modifications to peptides apply only to certain amino acids. For example, only serine, threonine, and tyrosine are receptive to phosphorylation. Similarly, only cysteine and methionine are commonly oxidized. It is also well established in the art that some point mutations of amino acids are more common than others. For example, glutamate is often seen to be substituted for glutamine, and asparate for asparagine. Consequently, when a small set of common modifications is considered, the number of possible modifications of a given peptide in a peptide database is relatively small. For example, the average peptide with a molecular weight between 600 and 2,000 daltons has two phosphorylation sites. By this calculation, adding singly-phosphorylated peptide variants to a peptide database will increase its size by a factor of 3.
[0091] Experimental evidence indicates that three specific modifications account for the majority of modified peptides measured in tandem mass spectrometers: oxidation of methionine, mutation of glutamine to glutamate, and mutation of asparagine to aspartate. For one peptide database, it has been calculated that adding variant peptides incorporating these three classes of modification would increase the database's size by 40% to 150%. It is important to note that the size of the index table is mostly invariant relative to the size of the peptide database used to generate it, i.e. the larger peptide database does not result in a significantly larger index table. Nor is the speed of the search significantly affected by the more heavily populated index table. Therefore, a modest increase in the calculation time of the index table can result in improved sensitivity and selectivity of a search without having a noticable impact on searching speed.
[0092] Equivalents
[0093] The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The foregoing embodiments are therefore to be considered in all respects illustrative, rather than limiting, of the invention described herein. Scope of the invention is thus indicated by the appended claims, rather than by the foregoing description, and all variants which fall within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.
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The present invention provides methods for matching a sample of an unknown query peptide to a database of known peptides. The methods described herein allow for the rapid, sensitive, and selective identification of an unknown query peptide, which enables the development of high throughput protein identification. The methods described herein also allow for mass spectrometry data for a query peptide to be categorized and weighted according to its quality. Furthermore, the methods described herein provide robust identification of modified query proteins by either anticipating modifications or adjusting for modified peptide masses.
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FIELD OF THE INVENTION
[0001] The invention relates to a method and apparatus for the removal of undesirable materials on the wall of an earth formation so as to allow the measurement of formation characteristics such as pressure. More particularly, the invention relates to a device that creates a wave discharge by pulsing a volume of fluid so as to produce a resonant oscillation in the fluid. The wave discharge is directed in the form of a concentrated beam against at least partially non-permeable membranes formed on the earth wall of a borehole in order to remove these materials from the wall of the borehole. Still more particularly, the described device creates oscillations that produce the wave discharge by using a Helmholtz resonance frequency in pulsing a fluid volume. The wave discharge will disintegrate mudcake formed on the earth formation borehole wall to allow the unobstructed measurement of formation pressure within the formation.
BACKGROUND OF THE INVENTION
[0002] The efficient recovery of subterranean hydrocarbons such as oil and gas is assisted by obtaining reliable data about the physical conditions in a formation of interest. For example, a target formation typically includes hydrocarbon fluids that are under high pressure. Accurately measuring the formation pressure where such pressurized materials reside promotes safe and cost-effective operations in nearly all phases of hydrocarbon recovery. However, techniques for measuring formation pressure must overcome a number of technical challenges. One obstacle to pressure measurement is the mudcake that drilling mud tends to deposit on the wall of the wellbore.
[0003] A wellbore is typically filled with a drilling fluid such as water or a water-based or oil-based drilling fluid. The density of the drilling fluid is usually increased by adding certain types of solids that are suspended in solution. Drilling fluids containing solids are often referred to as drilling muds. The drilling fluids cool and lubricate the drill bit and carry the cuttings uphole to the surface. The solids in drilling fluids also increase the hydrostatic pressure of the wellbore fluids. By selecting drilling fluids weighted to a particular density, the column of drilling fluids creates a pressure downhole, which is greater than the pressure of the fluids in the formation. When the drilling fluid pressure is greater than the formation fluid pressure, the well is said to be in an over balanced condition. Conversely, if the formation pressure is greater than the fluid column, then the well is said to be in an under balanced condition. Control of formation fluids flowing into the well under high pressure minimizes the risk of a well blowout.
[0004] While an over balanced condition prevents well blowouts, it also has disadvantages, such as increased drilling costs due to slower penetration into the formation. Drilling fluid pressure in excess of formation pressure slows the penetration of the drill bit into the formation. In certain well environments it is preferred to maintain a neutral or slightly under balanced condition so as to achieve drilling speeds faster than those achieved while drilling in an over balanced condition. Drilling Practices Manual, Preston Moore, P. 18-22 Pennwell Publishing, 1974. Consequently, it is desirable to maintain a neutral balance or a slightly under balanced condition to maximize drilling penetration into the formation.
[0005] Drilling fluids create a mudcake as they flow into a formation by depositing solids on the inner wall of the wellbore. The mudcake on the wall of the wellbore tends to act like a filter and tends to isolate the high-pressure fluids of the wellbore from the relatively lower pressures of the formation. The mudcake helps prevent excessive loss of drilling fluid into the formation. The static pressure in the wellbore and the surrounding formation is typically referred to as hydrostatic pressure. Pressure in the formation beyond the mudcake gradually tapers off with increasing radial distance outward from the wellbore.
[0006] The measurement of formation pressures during drilling operations assists in locating strata most likely to produce hydrocarbons efficiently. Typically after the borehole is drilled, the well is logged by lowering a package of sensors downhole that gather data about the formation. Pressure data is useful in judging when a formation contains hydrocarbons and when such a formation may economically produce hydrocarbons. Often a wellbore may pass through more than one hydrocarbon-bearing formation, and formation pressure data assists the drilling engineer in determining whether to halt or continue drilling.
[0007] Further, the ability to monitor formation pressure during drilling is important to the desired practice of continuously adjusting the drilling mud density. This facilitates drilling through the maximum amount of formation in the shortest amount of time.
[0008] To maintain the proper condition during drilling, whether neutral, over balanced or under balanced, it is necessary to measure the pressure of the formation fluids at the vicinity of the drill bit. However, the dynamic environment near the drill bit makes measurement of the formation fluids particularly difficult during logging while drilling (LWD) operations. In addition, the mudcake that forms on the wall of the borehole presents a further difficulty in determining formation fluid pressure at the bit during drilling. This mudcake forms a relatively non-permeable barrier between the instrument on the one side and the formation fluids on the other. The mudcake barrier hinders accurate measurement of the pressure of the formation fluids.
[0009] Prior art sensors are generally not capable of measuring formation fluid pressure during drilling. Consequently, rig personnel must closely monitor the drilling fluids flowing from the borehole for signs of increased formation fluid pressure. This often entails temporarily halting the drilling operation to allow pressure measurement of the formation. Once the drilling fluids show evidence of formation fluids flowing up the borehole, drilling is stopped and corrective measures are taken. However, this approach has particular drawbacks; and, it would be desirable to determine formation fluid pressure at the bit during drilling.
[0010] One such prior art instrument is a reservoir description tool (RDT) such as that disclosed in U.S. Pat. No. 5,644,076 (the '076 patent) entitled “Wireline Formation Tester Supercharge Correction Method”, incorporated herein by reference in its entirety. The RDT of the '076 patent includes a pressure sensing element mounted within a chamber of a housing having a piston to create a vacuum within the housing chamber. Hydraulic pads force the housing against the borehole wall; and, as the piston retracts to create a pressure reduction, a drawdown pressure removes the mudcake lining from the borehole wall. Fluids in the formation then enter the housing chamber allowing the pressure-sensing element to take a pressure reading. This tool allows only stationary measurements because drawdown pressure requires a tight seal between the housing and the borehole wall. This is undesirable because, aside from being time consuming, stationary measurements provide only discrete data points, not a continuous log. The drawback to discrete data points is that the fluid pressure between the discrete data points may vary dramatically and unpredictably.
[0011] Another borehole tool for removing the mudcake to measure the pressure of the formation fluids is disclosed in U.S. Pat. No. 5,969,241 (the '241 borehole tool) incorporated herein by reference. The '241 borehole tool measures pressure from within the borehole. A portion of the borehole wall is isolated from the surrounding borehole fluids by placing the chamber of the '241 borehole tool against the borehole wall. The chamber comprises a recess in an exterior surface of the '241 borehole tool. This patent describes an acoustic horn as the mechanism by which to excite fluids in a chamber. The mudcake present on the isolated portion of the borehole wall is disintegrated by an ultrasonic transducer, actuated by a piezoelectric stack, housed within the chamber. A pressure gauge then measures the pressure of the chamber to indicate the pressure of the earth formation.
[0012] Such a prior art tool also has deficiencies. For example, this borehole tool is inefficient because its vibrational energy does not transfer directly to the fluid. The vibrating born is limited in the efficiency by which it transfers electrical energy to acoustical wave energy. Excitation of the piezoelectric stack creates a longitudinal wave resonance within the ultrasonic transducer. As the ultrasonic transducer resonates longitudinally, the vibrational energy is transferred to the fluid. However, the mechanical coupling of the ultrasonic transducer to the fluid is poor, thus much of the vibrational energy imparted by the piezoelectric stack remains in the ultrasonic transducer. This inefficient energy transfer is expected to reduce the vibrational energy available to break down the mudcake. Further, such tools are not compact and are not easily installed in the drill string, which must pass through the confined area of the borehole.
[0013] Notwithstanding the foregoing described prior art, there remains a need for a device that possesses the features of efficiently transferring vibrational energy to create a focused wave discharge that may be used to remove mudcake from a borehole wall. Further, it is desired that such a device may be utilized so as to minimize any interruption to the drilling process. It is also desired that such a tool be capable of use on different down hole assemblies such as wire line operations and near the drill bit in drilling operations. Additionally, the tool should be able to take pressure measurements on a continuous or near-continuous basis as the drill string descends the well bore.
SUMMARY OF THE INVENTION
[0014] The present invention overcomes the aforementioned deficiencies of the prior art by providing a device that generates rhythmic pressure pulsations within a fluid-filled chamber, thereby producing a pressure wave discharge, which exits through an orifice of the chamber in a focused beam. The pulsations produced by the device include Helmholtz resonant frequencies for the geometry of the chamber; Helmholtz resonant frequencies efficiently transfer energy from pulse elements of the device to the fluids in the chamber. The device directs pressure waves in the fluids in the chamber through an orifice that focuses the waves against the borehole wall in the form of a concentrated beam. The wave discharge removes mudcake from the borehole wall, thereby opening a passage from the interior of the formation to the device chamber. In this manner pressure transducers associated with the device may accurately measure pressure from the formation. The device of the present invention operates with a speed that allows it to be used on a continuous to near-continuous basis. If disposed on a drill string, the drilling operation need not be slowed or halted in order for the present acoustic jet to function. Further the device may be used on both wireline operations and drilling operations.
[0015] The pressure reading tool of the present invention overcomes the deficiencies of the prior art by applying a fundamentally different approach to the removal of mudcake from borehole walls. For example, the '241 borehole tool induces vibrational frequencies in an acoustic horn to transfer the vibratory energy to the fluid. The tool of the present invention induces a resonance in the fluid itself. Thus, the poor energy transfer between the acoustic horn and fluid is eliminated. Further, the tool of the present invention concentrates and focuses the wave energy so as to minimize the loss of energy while simultaneously maximizing the energy brought to bear against the borehole wall.
[0016] One embodiment of the present invention includes pressure reading tool having a housing with an interior chamber and an orifice extending from the chamber to the exterior of the housing. A pulse member with a magnetostrictive ring and excitation source is disposed within the housing chamber to produce a highly agitated fluid discharge through the orifice. The magnetostrictive ring, chamber volume, and orifice may be designed to cooperate to induce Helmholtz resonance frequencies in the fluid in the chamber to thereby enhance the agitation of the fluid discharge. A sheathing may be used to encapsulate the pulse member to protect it from contact with the fluid. A dampening element may also be interposed between the pulse member and housing to isolate vibration.
[0017] In operation, the tool is disposed in the wall of the drill stem having a drill bit for penetrating the formation and forming a borehole. An impermeable membrane in the form of mudcake forms on the borehole wall due to the drilling fluids. A portion of the borehole wall is isolated by placing the tool against the borehole wall. The pulse member is actuated to modulate the chamber volume to produce agitated fluids within the chamber. The fluids are agitated at a high frequency within the chamber. The tool directs a stream of pressure waves through the orifice and against the impermeable membrane to remove the impermeable membrane. A pressure transducer communicates with the chamber to read the pressure of the formation fluids. These pressure readings are communicated with the surface to direct the drilling of the bit through the formation. The readings may be continuous while drilling.
[0018] Thus, the present invention comprises a combination of features and advantages that enable it to overcome various problems of prior art pressure measuring devices. The various characteristics described above, as well as other features, objects, and advantages, will be readily apparent to those skilled in the art upon reading the following detailed description of the preferred embodiments of the invention, and by referring to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] For a detailed description of a preferred embodiment of the present invention, reference will now be made to the accompanying drawings, which form a part of the specification, and wherein:
[0020] [0020]FIG. 1 is a cross-sectional close-up view of a drill string and well bore;
[0021] [0021]FIG. 2 is a cross-sectional view of a preferred embodiment of the present invention;
[0022] [0022]FIG. 3 is a cross-sectional close-up view of the preferred embodiment of FIG. 2; and
[0023] [0023]FIG. 4 is a cross-sectional view of three pressure reading tools positioned in three stabilizer blades of a down hole assembly.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0024] It should be appreciated that the invention may be embodied in many different forms. There are shown in the drawings, and herein will be described in detail, specific embodiments of the present invention. However, the present disclosure is an exemplification of the principles of the invention. It is not intended to limit the invention to the particular illustrated embodiments, which can be modified in the practice of the invention. For example the present invention may be used while logging on a wireline cable or in logging while drilling. The present invention is particularly advantageous in logging while drilling as further described below. The term “logging” is used herein in its broadest sense to include recording any type of data representing characteristics of the formation as a function of depth, including particularly the measurement of formation fluid pressure.
[0025] Referring initially to FIG. 1, there is shown the use of an embodiment of the present invention for logging while drilling. The pressure reading tool 60 is shown disposed in a bottom hole assembly 10 for drilling a borehole 12 . The borehole 12 extends from the surface down through a plurality of different earth formations such as exemplary formation 14 . Formation 14 may include various formation fluids 16 such as water, gas and hydrocarbons. These formation fluids 16 are under pressure. The logging while drilling embodiment of the bottom hole assembly 10 includes various members including a drill collar or drill stem 18 with a drill bit 20 connected thereto. It can be seen that the drill bit 20 is penetrating the formation 14 at the bottom 22 of the borehole 12 .
[0026] Drilling fluids 24 are pumped down through the drill string on which the bottom hole assembly 10 is disposed, to the bottom 22 of the borehole 12 and then return up the annulus 26 , formed by the drill string and wall 28 of borehole 12 , to the surface. The drilling fluids 24 lubricate and cool the bit 20 and remove the cuttings to the surface. As the column of drilling fluids circulates through borehole 12 , some of the drilling fluid solids 24 accumulate on wall 28 of borehole 12 forming a mudcake 30 . Mudcake 30 forms a relatively impermeable membrane between the drilling fluids and earth formation 14 . A pressure drop typically occurs across mudcake 30 .
[0027] The present pressure reading tool 60 is schematically shown disposed in aperture 32 of one of the drilling string members, such as drill stem 18 . Alternatively, the tool may be disposed on various pieces of downhole machinery. For example, in the embodiment shown in FIG. 4 pressure reading tools are placed in stabilizer blades 40 . Alternatively, the pressure reading tools may be placed on the drill stem 18 or on the drill collar. Alternatively, pressure reading tools may be positioned on a dedicated piece of machinery that is itself attached to the drill string. Similarly, the tool may be employed on a wireline.
[0028] While FIG. 1 portrays a single pressure reading tool disposed within the drilling apparatus, it should also be understood that more than one such tool may be included in any particular down hole assembly. For example, in one embodiment three pressure reading tools are disposed within the same drill collar or drill stem. As shown in FIG. 4, a particular drill collar has three stabilizer blades 40 . There is a tool of the present invention disposed in each of the three stabilizer blades. In that embodiment, each of the three tools is at the same horizontal position on the drill stem; however, each tool is separated radially. In this manner, the three tools record formation pressure from sections of the formation at differing azimuthal positions. In an alternative embodiment a drill collar or drill stem may be arrayed with multiple tools at differing horizontal positions. There is an advantage associated with the use of multiple pressure reading tools. As the number of such tools increases, so does the chance of successfully obtaining an accurate formation pressure reading at a particular location. Conditions inherent in drilling, such as the vibrations and mechanical shocks found in the drilling environment, raise the possibility that mechanical equipment such as the pressure reading tool may be rendered inoperable. Likewise, a poor seal between the borehole wall 28 and orifice 76 of the tool may affect the pressure reading taken by the tool. In both these instances, the placement of multiple tools on the drill string increases the chance of a successful reading.
[0029] In both FIG. 1 and FIG. 4 tool 60 is directed radially outward toward mudcake 30 . In this manner, tool 60 produces and directs a wave discharge for removing the mudcake to allow the measurement of formation fluid pressure while drilling as hereinafter described in detail.
[0030] Referring now to FIG. 2, there is shown a preferred embodiment of the tool 60 , which includes a pressure reader 64 , a housing 66 , and pulse device 70 for producing an agitated fluid discharge using Helmholtz resonance frequencies, thus enabling pressure readings of the earth formation. Housing 66 is generally defined by a cylindrical wall 82 , an outer cap 74 , and an inner cap 75 . The generally hollow interior of housing 66 forms a chamber 84 . Chamber 84 itself is generally cylindrical in shape, as it is defined by cylindrical wall 82 , outer cap 74 , and inner cap 75 . Outer cap 74 includes an orifice 76 . Outer cap 74 may be at least partially hardened against frictional wear caused by movement across borehole wall 28 . Hardening of outer cap 74 may be through a surface treatment or a “wear plate” mounted on outer cap 28 . Inner cap 75 is adjacent the inside diameter of drill stem 18 and includes a conduit 78 at its center, which is substantially opposite orifice 76 in outer cap 74 . Inner cap 75 also includes one or more feed-through holes 80 , 81 for receiving electrical conduits 83 , 85 . Outer cap 74 or inner cap 75 may be removable to allow access to chamber 84 .
[0031] The tool has been described as having a chamber with a generally cylindrical interior geometry. While such a shape is believed to be advantageous for the transfer of energy from an electrical form to an acoustic form, the chamber may nevertheless assume other configurations. Any chamber geometry is possible, including, but not limited to, conical, spherical, cubic, rectangular, tetragonal, pyramid-shaped, elliptical, ovoid, parabolic, and polygonal.
[0032] Conduit 78 is also preferably substantially opposite orifice 76 . While this is believed advantageous, alternative placements of conduit 78 are also possible. For example, conduit 78 could be placed in cylindrical wall 82 . Also, conduit 78 could be placed in an off-center position on inner cap 75 . These examples are for illustrative purposes only and are not meant to be limiting.
[0033] According to the embodiment as shown in FIG. 2, outer cap 74 is curved so as to follow the shape of borehole wall 28 . Outer cap 74 would be disposed adjacent the borehole wall. In this embodiment, outer cap 74 may be hardened to withstand the contact with borehole wall 28 . In alternative embodiment, however, outer cap 74 is positioned some distance from borehole wall 28 so as to avoid direct contact with borehole wall 28 . As shown in FIG. 4, the pressure reading tool is positioned in a stabilizer blade of the downhole assembly. In this configuration, stabilizer blade 40 contacts borehole wall. Outer cap 74 is slightly recessed so that it does not directly contact borehole wall. In the configuration of FIG. 4, outer cap 74 need not assume a curved shape; nor does it need to be hardened.
[0034] Preferably, housing 66 is sufficiently compact to fit into a drill collar, drill stem 18 , stabilizer blade 40 , or wireline device. The pressure reading tool may be preassembled and installed as a unit in a machined or precut aperture 32 of a selected drill piece. Some known attachment means may be used in order to affix the pressure reading tool to the drill piece. Known attachment methods include, but are not limited to, a pressure fitting, pins, threading, bolting or gluing. Preferably, a threaded lock ring 42 , shown in FIG. 4, secures the pressure reading tool to the drill piece. The body of housing 66 may also seal aperture 32 so as to prevent the interior of the drill string passing fluids to or from the exterior of the drill string. This is preferably accomplished by o-ring seals 44 . Material selection for housing 66 is largely driven by downhole environment conditions. Generally, a corrosion resistant steel will provide the necessary ruggedness for borehole applications. Acceptable materials include steels such as 17-4PH or MP-35N.
[0035] Referring now to FIGS. 2 and 3, cylindrical wall 82 of chamber 84 is preferably at least partially lined with dampening element 86 . Preferably, dampening element 86 is made of a relatively soft material such as lead. Because tool 60 may be used along with an array of wireline instruments, it is preferred that the operation of tool 60 be dampened to prevent the transmission of vibrations along the drill string. This serves to minimize interference with other drill string instruments. Thus, cylindrical wall 82 of chamber 84 is lined on its interior preferably with a layer of lead to absorb much of the vibrations. In lieu of a lining, dampening element 86 may be a lead ring formed to seat at least partially along interior cylindrical wall 82 . It is emphasized that these are only two non-limiting examples of elements suitable for dampening. It is also emphasized that the dampening element is a convenient feature and may not be essential to the satisfactory operation of tool 60 . Alternatively any members that constitute housing 66 such as cylindrical wall 82 , outer cap 74 , and inner cap 75 may be selected of a material and dimension sufficient to perform any needed dampening function.
[0036] Pulse device 70 is disposed within chamber 84 and comprises a member or members that can physically oscillate in response to a signal. In the preferred embodiment of FIG. 2, pulse device is a generally annular or ring-shaped member disposed within chamber 84 . Pulse device 70 seats substantially contiguously along the interior surface of cylindrical wall 82 , or, if present, along the interior surface of dampening element 86 . Preferably, pulse device 70 extends along the length of cylindrical wall 82 such that the ends of pulse device 70 rest against the interior surfaces of outer cap 74 and inner cap 75 .
[0037] In the preferred embodiment, pulse device 70 seats substantially contiguously along the interior surface of cylindrical wall 82 . In this manner, the physical oscillations of pulse device 70 efficiently transfer energy to fluid in chamber 84 at all positions along the interior surface of pulse device 70 . However, it is possible to configure pulse device 70 in an alternative manner. For example, rather than being configured as a single, ring-shaped body, pulse device 70 could comprise any number of discrete units, of any geometry. These separate units could be placed at different locations within chamber 84 . A plurality of individual pulse device units could approximate the form and function of a ring-shaped pulse device when such individual units are placed in proximity to one another along the interior surface of cylindrical wall 82 . Alternatively, discrete pulse device units could be placed on the interior surfaces of outer cap 74 and inner cap 75 . Additionally, pulse device units could even be placed at some interior position of chamber 84 . If housing 66 is selected such that it defines chamber 84 to have a non-cylindrical geometry, then pulse device 70 may also have an alternative configuration and placement in the chamber. It would also be possible, and would be within the scope of this invention, to construct housing 66 with recesses or voids so as to have a honeycombed configuration. In such a configuration, pulse device units could be disposed within the recesses of housing 66 .
[0038] Pulse device 70 may itself be composed of separate elements. In the ring-shaped, preferred embodiment, shown in FIG. 3, pulse device 70 has pulse elements 88 at its core. Excitation source 90 wraps around pulse elements 88 , and sheathing 72 excitation source 90 . Sheathing 72 thus forms the external surfaces of the preferred pulse device 70 .
[0039] Sheathing 72 is preferably made of an elastomeric material to insulate the pulse device 70 from harmful contact with borehole fluids and particulates. Accordingly, the material for sheathing 72 should be selected to provide a impermeable barrier between the borehole environment and pulse device 70 . Another consideration in material selection is the need to efficiently couple the energy of pulse device 70 to the fluid in chamber 84 . Thus, sheathing 72 should be a resilient medium that provides efficient transfer of pulsing motion from pulse device 70 to the fluid. Generally, the modulus of elasticity of the material for sheathing 72 should be closer to that of rubber than that of steel. Materials with relatively high material stiffness will tend to limit the motion of pulse device 70 . Rubber meets the requirements of elasticity and impermeability. Other materials such as Teflon may also be designed to have the requisite material properties. Further, sheathing 72 also provides a resilient support for pulse device 70 in housing chamber 84 . Preferably, the thickness of sheathing 72 should secure pulse device 70 within housing 66 without unduly impeding the oscillating motion of pulse device 70 .
[0040] Still referring to FIG. 3, pulse device 70 includes a plurality of pulse elements 88 wrapped within excitation source 90 . Pulse elements 88 physically distort in response to an excitation signal. As pulse elements 88 physically distort, the volume of chamber 84 rhythmically increases and decreases, thereby producing a pulsation of the fluid within chamber 84 . Preferably, pulse elements 88 are a ring of magnetostrictive elements capable of radial oscillatory expansion and contraction when activated. Excitation source 90 can include windings that are capable of transferring magnetic flux signals. Magnetic flux is the excitation signal that causes magnetostrictive elements to physically distort. The windings of excitation source 90 are wrapped around the magnetostrictive elements and exit housing 66 via housing feed-through holes 80 , 81 . Outside the housing, the wires may connect with an external signal source. While feed-through holes 80 , 81 allow the winding wires of excitation source 90 to exit, it is otherwise sealed to segregate fluid within chamber 84 . Pressure boots may provide one mechanism by which to make the electrical connection from wiring to the pressure reading tool.
[0041] Alternatively, pulse elements 88 may be a plurality of piezoelectric elements. As with the magnetostrictive ring, the piezoelectric elements are formed into an annular or ring shape. A preferred piezoelectric material is PZT-5A Piezoelectric Material, available from EDO Corporation, Salt Lake City, Utah, 84115. Whether piezoelectric elements or magnetostrictive elements are used depends on the demands of a particular application. For example, it is generally understood that piezoelectric elements are more brittle than magnetostrictive elements and may be more easily damaged. However, a particular situation may require the higher frequency oscillations that are more efficiently provided by piezoelectric elements. In any event, magnetostrictive and piezoelectric elements are given as illustrative examples of a material that can produce harmonic pulsation of the fluids in chamber 84 . Pulse elements 88 are not intended to be limited to these two materials.
[0042] Orifice 76 will focus the pressure wave discharge into a concentrated beam. However, one skilled in the art will understand that the profile of orifice 76 can be easily modified for alternate fluid discharges. Thus, nearly any profile may be utilized for chamber 84 and orifice 76 . If a Helmholtz chamber is desired, the resulting volume and geometry must satisfy the Helmholtz resonance frequency requirements. In certain downhole applications, it is foreseeable that it may not be possible to design housing 66 to create Helmholtz resonance frequencies. In such cases, it will be apparent to one skilled in the art to adjust the geometry of housing 66 and orifice 76 to produce an agitated fluid discharge.
[0043] A Screen 68 is preferably positioned within chamber 84 on outer cap 74 proximate to orifice 76 . Screen 68 can prevent borehole particulates from entering chamber 84 . When the fluid in chamber 84 is vibrated, fluid in the immediate vicinity of orifice 76 develops the highest fluid velocity. It is preferable not to restrict such fluid movement. However, if screen 68 is placed too far from orifice 76 , it may allow borehole particulates to enter chamber 84 and damage pulse device 70 . Preferably, screen 68 is placed to allow the highest velocity fluid movement through orifice 76 . Further, screen 68 includes a plurality of openings designed to minimize impedance to fluid movement. Preferably, screen 68 is formed of stainless steel and secured to outer cap 74 . While particulates capable of damaging tool 60 are often present in a borehole environment, it is emphasized that satisfactory operation of tool 60 is not dependant on the presence of screen 68 .
[0044] A pressure reader 64 is mounted to housing 66 . Conduit 78 provides fluid communication between pressure reader 64 and chamber 84 . Pressure reader 64 preferably includes a threaded portion that may engage mating threads within conduit 78 . Alternatively, pressure reader 64 may be secured to housing 66 by some alternative means. Because conduit 78 provides access to chamber 84 , the fluids in chamber 84 pass through conduit 78 and contact a surface of pressure reader 64 such that the pressure of the fluids can be measured. It is preferable to locate pressure reader 64 as closely as possible to chamber 84 . A remotely mounted pressure reader 64 requires a longer conduit 78 , which may be more susceptible to plugging by borehole particulates. Commercially available pressure transducers can be utilized as the pressure reader 64 in the present invention. One such pressure transducer is a strain gage based pressure transducer manufactured by Paine, Inc. Quartz gage pressure transducers are more accurate and may be used. Such devices are usually more bulky and thus of limited suitability to borehole applications.
[0045] While it is not essential to the invention, in the preferred tool 60 , the geometry of housing 66 , chamber 84 , orifice 76 , and pulse device 70 are selected to produce Hehnholtz resonance frequencies in the fluid expected to be encountered in the drilling environment. Helmholtz resonance is a well-known scientific principle. The shape and design of Helrnholtz cavities or Helrnholtz resonators is also known in the industry. One kind of Helmholtz resonator is an enclosed cavity of fluid with an open port. If the volume of fluid in the cavity is compressed, the fluid attempts to spring back to its original volume. Physical oscillations in the fluid within a ported cavity tend to resonate at specific frequencies.
[0046] The natural resonant frequency for a spherical Helmholtz resonator ported with a cylindrical neck in an atmospheric environment may be represented by the following equation:
f r = c 2 π A LV
[0047] where
[0048] c=speed of sound in the fluid
[0049] V=cavity volume
[0050] A=cross sectional area of the neck, and
[0051] L=lengthoftheneck
[0052] This equation necessarily changes as the fluid is changed from air to another medium. Likewise, as other factors such as the geometry of the chamber and neck become more complicated, the classical equation breaks down. Hence the selection of an optimal frequency in the pressure reading tool must also be guided by trial-and-error methods. Given the changing environment in an active wellbore arising from factors such as changing pressures and the changing densities of fluids present in the wellbore, it is sometimes necessary to design a resonating chamber that can function across a variety of frequencies.
[0053] A preferred design of the present invention was tested in laboratory conditions. The fluid was a drilling mud with density of approximately 1500 kg/m 3 . The speed of sound in this material was estimated at 1500 m/s. At approximately 42 kHz the preferred embodiment of the present invention displayed a relatively low impedance while retaining good sound pressure levels. At this frequency the design was found to generate a cylindrical standing wave in laboratory testing.
[0054] One preferred embodiment of pressure reading tool 60 previously described has the following dimensions. The diameter of the chamber 84 in the fully assembled tool, i.e., the chamber diameter as defined when pulse device 70 is in place, is approximately 1.10 in. The diameter of chamber 84 with pulse device 70 removed is approximately 1.75 in. No dampening element 86 was present. The annular pulse device 70 thus has a ring thickness of approximately of 0.325 in. The depth of chamber 84 is approximately 1.00 inch. Outer cap 74 has a thickness of approximately 0.250. Inner cap 75 has a thickness of approximately 0.50 in. The cylindrical interior wall is approximately 0.25 in. thick. Orifice 76 , centered in outer cap 74 , has an opening diameter, measured at the exterior wall of outer cap 74 , of approximately 0.50 in.; and orifice 76 widens toward the interior of chamber 84 at an angle of approximately 28°.
[0055] In this preferred embodiment, pulse device 70 , with an annular ring thickness of approximately 0.325 in., was further designed as follows. Sheathing 72 was as long as the interior length of chamber 84 , approximately 1.00 in., and assumed the ring thickness of the pulse device 70 , approximately 0.325 in. An annular-shaped magnetostrictive assembly, composed of a magnetostrictive ring with windings, was approximately 0.75 in. long and approximately 0.10 in. in thickness. The magnetostrictive assembly formed the interior of pulse device 70 . The magnetostrictive assembly had an interior diameter of approximately 1.30 in. and an exterior diameter of approximately 1.50 in. Given the differences in diameters, the magnetostrictive assembly was thus placed in sheathing 72 in a slightly off center position. The distance from the interior surface of sheathing 72 to the interior surface of the magnetostrictive assembly was approximately 0.20 in. However, the distance from the exterior surface of sheathing 72 to the exterior surface of the magnetostrictive assembly was approximately 0.25 in. In the assembled pulse device the magnetostrictive assembly was placed equidistant from the interior surfaces of outer cap 74 and inner cap 75 , approximately 0.125 in. from each.
[0056] In operation, rig personnel will install preferred tool 60 into a drilling structure such as a drill stem 18 , on a stabilizer blade 40 , or drill collar. The appropriate electrical connections are made to link pulse device 70 with a signal source. Pressure reader 64 may also be linked with an appropriate display device or recording device, usually located at a control point on the surface. Such a link is preferably done through an electronic data connection.
[0057] To take pressure readings during LWD, the assembled tool is lowered into borehole 12 . When the drill string approaches a formation region of interest, several steps will take place. Of initial importance is the seal between orifice 76 of tool 60 and borehole wall 28 . The measuring of formation pressure with the pressure reading tool is best accomplished when the tool is placed firmly against the formation wall. In one embodiment, the face, or outer cap 74 , of tool 60 is curved so as to make full contact against the curved face of the borehole wall 28 . Outer cap 74 seals against borehole wall 28 and traps fluids, such as drilling fluids within chamber 84 . Alternatively, where outer cap 74 is recessed relative to stabilizer blade 40 , it is stabilizer blade 40 or alternate drill string structure that forms a seal with borehole wall 28 . A tight seal is provided between preferred tool 60 and borehole wall 28 to ensure that pressure reader 64 receives the pressure of formation 14 , and not the fluids in borehole 12 . Placement of multiple tools on a drill string, each tool placed at a differing radial position, increases the probability that the orifice of at least one such tool will be in sufficiently sealed contact with the borehole wall to assure an accurate pressure reading.
[0058] The procedure for obtaining a pressure reading continues with electrical signals of a chosen frequency or frequencies delivered to tool 60 . These signals activate pulse device 70 at a corresponding mechanical frequency. Activation of pulse device 70 causes it to oscillate, thereby imparting a rhythmic expansion and contraction of the volume of chamber 84 . The rhythmic expansion and contraction of the volume in chamber 84 imparts pressure waves in the fluid. This wave energy flows through the only point of discharge, orifice 76 . Orifice 76 focuses the wave discharge into a concentrated beam. Because the pulsation frequency causes the fluid to resonate at a Helmholtz frequency, pulse device 70 efficiently transfers energy to the fluid discharge.
[0059] The near instantaneous result is a flow of wave energy expelled from the tool. Orifice 76 directs the wave discharge toward borehole wall 28 layered with mudcake 30 . The fluid pulsations strike mudcake 30 , flush away the mudeake 30 , and thereby restore permeability to borehole wall 28 .
[0060] At this point electrical signals to the tool can stop, and the fluid oscillation thereby ceases. The necessary period is allowed for the hydrocarbons in formation 14 to pressurize tool chamber 84 . The time period needed to pressurize chamber 84 will vary depending on factors such as the permeability of the formation and the pressure in the formation. The fluids in formation 14 seep through borehole wall 28 and into chamber 84 through orifice 76 . With hydraulic communication established via conduit 78 , chamber 84 and orifice 76 , pressure reader 64 can measure formation fluid pressure. As is known in the art, it is possible to estimate formation pressure without the need for the pressure to equalize between that of the formation and that of the chamber. Pressure reader 64 transmits the pressure data to the surface.
[0061] The tool allows for continuous or near-continuous readings of formation pressure. In the logging while drilling embodiment, the movement of the drill string downward as drilling progresses also moves the tool vertically downward. However, the tool receives pressure readings from a given point on the borehole wall prior to the time that the tool descends past this point of the borehole wall. The tool clears mudcake from the borehole wall and records the formation pressure associated with the cleared area of borehole wall, prior to the orifice moving past that cleared point. Once the orifice does descend past a point on the borehole wall that has been cleared and measured for pressure, the process can begin anew. At a new, lower point on the borehole wall, the tool clears mudcake and again records formation pressure. The points of pressure measurement can be closely spaced so as to allow recording of pressure data in a continuous or near-continuous fashion. In this manner the tool will take formation pressure readings at a series of points, in an ongoing fashion, while the drill string makes its normal descent in the formation. There is no need to halt drilling in order to make these pressure readings.
[0062] Preferred tool 60 provides a direct reading of formation fluid pressure that can be used to adjust the borehole pressure. That is, rig personnel can select a borehole pressure that prevents formation fluid from invading the borehole 12 without creating an excessive borehole pressure that slows drilling speed. Referring back to FIG. 1, during LWD, preferred tool 60 can be linked with a downhole telemetry system 100 to transmit formation pressure data uphole. For example, downhole telemetry system 100 could include control circuitry 102 to energize preferred tool 60 and a drive circuitry/transmitter 104 to receive pressure data from preferred tool 60 to transmit the pressure data to the surface. Drive circuitry/transmitter 104 may utilize a mud siren to transmit data in the form of pressure pulses in the drilling mud flowing uphole. Monitors 106 on the surface receive and process the pressure data transmitted by downhole telemetry system 100 . Such a system could be configured to provide continuous transmission of pressure data. Alternatively, the drive circuitry could be designed to transmit pressure data only after a threshold pressure is sensed by pressure transducer. In any event, data transmission systems for LWD in the prior art are well known, and one of ordinary skill in the art will understand how to relay pressure readings obtained from preferred tool 60 to monitoring systems on the surface. Further, one of ordinary skill in the art will know how to modify drilling mud to create a specific borehole pressure.
[0063] A similar approach is followed for deploying preferred tool 60 during wireline logging operations. For wireline logging, a preferred tool 60 is usually one of several tools in a package lowered downhole. Thus, preferred tool 60 may transmit pressure data via the wireline cable to the surface. A continuous log requires that preferred tool 60 be dragged along borehole wall 28 . While it is believed that tool 60 will remove mudcake nearly instantaneously, a similarly instantaneous pressure reading may not be possible. A lag time may be involved with wireline logging. Lag time calculations are discussed in the '076 patent referenced above and incorporated by reference in its entirety. Thus, pressure reader 64 provides pressure data that allows an accurate reading of formation fluid pressure even though the fluid pressure in chamber 84 and formation 14 have not equalized.
[0064] While preferred embodiments of this invention have been shown and described, modifications thereof can be made by one skilled in the art without departing from the scope or teaching of this invention. The embodiments described herein are exemplary only and are not limiting. Accordingly, the scope of protection is not limited to the embodiments described herein, but is only limited by the claims that follow, the scope of which shall include all equivalents of the subject matter of the claims. In the claims, the recitation of steps in a sequential order is not intended to require that the steps be performed in that order, unless explicitly so stated.
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The pressure reading tool includes a housing with an interior chamber and an orifice extending from the chamber to the exterior of the housing. A pulse member with a magnetostrictive ring and an excitation source are disposed within the chamber to produce a highly agitated fluid discharge through the orifice. The magnetostrictive ring, chamber volume, and orifice cooperate to induce Helmholtz resonance frequencies in the fluid in the chamber to thereby enhance the agitation of the fluid discharge. A sheathing encapsulates the pulse member to protect it from contact with the fluid. A dampening element is also interposed between the pulse member and housing to isolate vibration.
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CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority to U.S. Patent Application Publication No. 2012/0104024, filed on Oct. 29, 2010, entitled “REFRIGERATOR WITH BEVERAGE DISPENSER CLEANING SYSTEM,” the disclosure of which is hereby incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
The present invention generally relates to a beverage dispenser. More particularly, but not exclusively, the present invention relates to a refrigerator beverage dispenser having a cleaning subsystem.
BACKGROUND OF THE INVENTION
The background of the invention is discussed in the context of a beverage dispenser used in a refrigerator. The present invention is not to be limited to this specific context. Refrigerators have long been used to dispense fluid such as water. More recently it has been desirous to provide refrigerators with beverage dispensers. One of the problems of dispensing beverages from a refrigerator relates to keeping the beverage dispensing system clean. Failure to keep a beverage dispensing system clean may adversely affect its use. In addition failure to clean may lend to flavor contamination. Yet users may not be willing to take the steps necessary to properly clean a beverage dispenser.
What is needed is an apparatus and method for a refrigerator with a beverage dispensing system which is easy and convenient to clean.
BRIEF SUMMARY OF THE INVENTION
Therefore it is a primary, object, feature, or advantage of the present invention to improve over the state of the art.
It is a further object, feature, or advantage of the present invention to provide a refrigerator with a beverage dispensing system capable of self-cleaning.
Another object, feature, or advantage of the present invention is to provide a refrigerator with a beverage dispensing system which is easy and convenient for a user to operate.
One or more of these and/or other objects, features, or advantages of the present invention will become clear from the specification and claims that follow. No single embodiment need exhibit each and every object, feature, or advantage.
A still further object, feature, or advantage of the present invention is to assist in preventing flavor contamination.
According to one aspect of the present invention a method of using a refrigerator with a beverage dispensing system is provided The method includes providing a refrigerator having a refrigerator cabinet and a beverage dispenser operatively connected to the refrigerator cabinet. The method further includes receiving an indicia from a user to dispense a beverage. The method further includes dispensing the beverage and circulating a cleaning fluid through the fluid line or the fluid enhancement line for cleaning after dispensing.
These and other aspects, objects, and features of the present disclosure will be understood and appreciated by those skilled in the art upon studying the following specification, claims, and appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front elevation view of a refrigerator with a beverage dispenser.
FIG. 2 is a schematic representation of the refrigerator beverage dispenser.
FIG. 3 is a schematic representation of the refrigerator beverage dispenser cleaning system.
FIG. 4 is a schematic representation of the refrigerator beverage dispenser with a cleaning subsystem.
FIG. 5 is a schematic representation of the refrigerator beverage dispenser with a cleaning subsystem and drain.
FIG. 6 is a schematic representation of the refrigerator beverage dispenser with a permanent cleaning subsystem and drain.
FIG. 7 is a schematic representation of the refrigerator beverage dispenser with a permanent cleaning subsystem.
FIGS. 8A-B represent a cleaning cartridge for use in a cleaning subsystem of a beverage dispenser.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 illustrates a refrigerator 10 having a fresh food compartment 14 and a freezer compartment 12 . A fresh food compartment door 18 provides access to the fresh food compartment 14 . The freezer compartment door 16 provides access to the freezer compartment 12 . The refrigerator 10 includes a beverage dispensing system 20 which is shown at the door 16 . The beverage dispenser 20 may include a user interface with control buttons 84 which enable a user to select a preferred dispensing operation. Of course, other types of user interfaces may be provided. A first nozzle 90 in the dispenser 20 may deliver a flow of fluid downward. A second nozzle 92 adjacent the first nozzle 90 in the dispenser 20 may also deliver a flow of enhanced fluid downward. In FIG. 1 , the refrigerator 10 is shown in a side-by-side configuration. Of course, the refrigerator 10 may take on other configurations as well, such as a bottom mount freezer configuration.
FIG. 2 illustrates a first embodiment which shows the beverage dispenser 20 and associated components for beverage dispensing. The beverage dispenser 20 includes a fluid supply 22 and a fluid enhancement component 24 . The fluid supply 22 is controlled by a valve 36 . The fluid supply may supply conditioned or unconditioned fluid, such as, unfiltered fluid, filtered fluid, carbonated fluid, uncarbonated fluid, water, or filtered water. The fluid lines 34 and 38 provide paths to the beverage mixer 32 . The fluid enhancement component 24 may be housed within a BIB (bag-in-box), a cartridge, a bottle, or any other type of fluid enhancement container. The fluid enhancement component 24 may connect directly into the pump 26 or via the liquid enhancement line 46 or otherwise. The fluid enhancement component 24 may be drawn through the pump 26 . The pump 26 is one component of a pumping mechanism 72 . The pumping mechanism 72 also may include a motor 28 which actuates the pump 26 and may also be easily separated from the pump 26 . The pump 26 may be easily removed by a consumer. The pump 26 may also be disassembled and cleaned by the consumer either by hand or in a dishwasher. The pump 26 may also be attached to a replaceable cartridge and disposed of or returned and cleaned when the cartridge is refilled. As shown in FIG. 2 , the fluid supply 22 and the fluid enhancement component 24 are introduced at a beverage mixer 32 via supply lines 38 and 48 , respectively. The fluid and fluid enhancement may then mix an output to a cup 52 via a beverage mixer line 58 . The beverage mix line 58 is operatively connected to the nozzle 92 , such as shown in FIG. 1 . The fluid supply valve 36 and the pumping mechanism 72 may be controlled by the control unit 30 in a manner such that a predetermined ratio of the fluid enhancement from the fluid enhancement component 24 to the fluid from the fluid supply 22 is delivered to the beverage mixer 32 . Hence, whenever a beverage is requested via the beverage dispenser 20 user interface, the control unit 30 receives this input request and dispenses the selected beverage.
FIG. 3 illustrates another embodiment which shows the beverage dispenser 20 and associated components for beverage dispensing. The beverage dispenser 20 includes the fluid supply 22 and the fluid enhancement component 24 . The fluid supply 22 is controlled by the valve 36 . The fluid lines 34 and 38 provide a path to the beverage mixer 32 . The fluid enhancement component 24 may be housed within a BIB (bag-in-box), a cartridge, a bottle, or any other type of fluid enhancement container. The fluid enhancement component 24 flows through the pump 26 and the lines 42 , 46 respectively via the valve 44 . The fluid enhancement component 24 may connect directly into valve 44 or via the fluid enhancement line 46 . The beverage mixing system may utilize a manifold wherein the fluid enhancement component 24 , the fluid supply 22 , the beverage mixer 32 and the pumping mechanism 72 are interconnected without the use of the various fluid lines. The fluid enhancement component 24 is drawn through the pump 26 . The pump 26 is one component of the pumping mechanism 72 . Pumping mechanism 72 also has a motor 28 which actuates the pump 26 and also may be easily separated from the pump 26 . The pump 26 is designed to be easily removable for replacement. The fluid supply 22 and the fluid enhancement component 24 are introduced at the beverage mixer 32 via the supply lines 38 and 48 respectively. The two fluids are then mixed and output to a cup 52 via a beverage mix line 58 . The beverage mix line 58 is mated to the nozzle 92 , refer to FIG. 1 . The fluid supply valve 36 and the pumping mechanism 72 may be controlled by the control unit 30 in a manner such that a predetermined ratio of the fluid enhancement to fluid is delivered to the beverage mixer 32 . Hence, whenever a beverage is requested via the user interface of the beverage dispenser 20 , the control unit 30 receives this input request and dispenses the selected beverage. The pumping mechanism 72 , and more specifically the pump 26 is cleaned of residue from the fluid enhancement component 24 by flushing the lines 46 , 48 and 58 with a small amount of the fluid from the fluid supply 22 . The fluid is dispensed into the cup 52 after the initial beverage is mixed. This additional amount of fluid may have a minimum impact on the taste of the mixed beverage. Alternatively, instead of a beverage mixer 32 , fluid supply 22 and fluid enhancement 24 may be delivered directly to cup 52 .
FIG. 4 illustrates another embodiment wherein a cleaning cartridge or a cleaning subsystem 50 which may be swapped into the same position as the fluid enhancement 24 as they share the same configuration. The pumping mechanism 72 , and more specifically the pump 26 may be cleaned of residues from the fluid enhancement component 24 by directing the cleaning solution within the cleaning subsystem 50 through the line 42 , the valve 44 , and the lines 46 and 48 which are operatively connected to the pump 26 . The control unit 30 may then direct the fluid supply 22 to flow through the lines 34 , 40 , 46 , 48 and 58 by actuating the valves 36 and 44 , and through the pumping mechanism 72 to rinse all the lines and the pump 26 of the cleaning solution. The control unit 30 may alert the consumer via the beverage dispenser 20 display 86 when the pump 26 should be cleaned or the consumer may independently initiate a cleaning cycle for the pump 26 by pressing the control button 84 associated with initiating a cleaning cycle. In either example, the consumer may place the cup 52 beneath the beverage dispenser nozzle 92 to collect cleaning solution for disposal.
FIG. 5 illustrates another embodiment wherein a cleaning cartridge or a cleaning subsystem 50 which may be swapped into the same position as the fluid enhancement 24 as they share the same configuration. The pumping mechanism 72 and more specifically the pump 26 may be cleaned of residues from the fluid enhancement component 24 by directing the cleaning solution within the cleaning subsystem 50 through the line 42 , the valve 44 , and the lines 46 and 48 which are operatively connected to the pump 26 . The control unit 30 may then direct the fluid supply 22 to flow through the lines 34 , 40 , 46 , 48 and 58 by actuating the valves 36 and 44 , and through the pumping mechanism 72 to rinse all the lines and the pump 26 of the cleaning solution. The control unit 30 may alert the consumer via the beverage dispenser 20 display 86 when the pump 26 should be cleaned or the consumer may independently initiate a cleaning cycle for the pump 26 by pressing the control button 84 associated with initiating a cleaning cycle. In either example, the consumer may place a cup beneath the beverage dispenser nozzle 92 or the consumer may allow the cleaning solution to flow directly into a plumbed drain or a non-plumbed drain 54 .
FIG. 6 illustrates another embodiment wherein a cleaning cartridge or a cleaning subsystem 50 is positioned next to the fluid enhancement component 24 instead of being swapped into and out of the same position as the fluid enhancement component 24 , refer to FIG. 5 . The pumping mechanism 72 and more specifically the pump 26 may be cleaned of residues from the fluid enhancement component 24 by directing the cleaning solution within the cleaning subsystem 50 through the line 62 , valve 44 , line 46 , pump 26 and line 48 which feeds beverage mixer 32 and dispenses via line 58 . The control unit 30 may then direct the fluid within fluid supply 22 to flow through lines 34 , 40 , 46 , 48 and 58 by actuating valves 36 and 44 , and pumping mechanism 72 to rinse the lines and pump 26 of the cleaning solution. The control unit 30 may alert the consumer via the beverage dispenser display 86 when the pump 26 should be cleaned or the consumer may independently initiate a cleaning cycle for the pump 26 pressing the control button 84 associated with initiating a cleaning cycle. In either example, the consumer may place the cup 52 beneath the beverage dispenser nozzle 92 to collect cleaning solution for disposal. Or a plumbed or non-plumbed drain 54 may be implemented for removing the cleaning solution as opposed to the cup 52 .
FIG. 7 illustrates another embodiment wherein a cleaning cartridge or a cleaning subsystem 50 is positioned next to the fluid enhancement component 24 instead of being swapped into and out of the same position as the fluid enhancement 24 , refer to FIG. 5 . Referring to FIG. 8A , a cleaning subsystem 50 contains the unused cleaning solution 78 and the used cleaning solution 80 which are separated by a flexible divider 82 to form a first chamber 83 and a second chamber 85 . The cleaning solution 78 from the first chamber 83 enters the beverage dispensing system 20 via a check valve 74 through a line 62 . The used cleaning solution 80 returns to the second chamber 85 of the cleaning subsystem 50 through the line 68 via a check valve 76 . The pumping mechanism 72 , and more specifically the pump 26 may be cleaned of residue from the fluid enhancement component 24 by directing the cleaning solution 78 within the cleaning subsystem 50 through the line 62 , the valve 44 , the line 46 , the pump 26 and the line 48 which feeds the beverage mixer 32 and continues via the line 64 to the valve 66 which directs the flow path to the line 68 and returns the used cleaning solution 80 to the cleaning subsystem 50 . The control unit 30 may then direct the fluid within the fluid supply 22 to flow through the lines 34 , 40 , 46 , 48 , 64 and 68 by actuating the valves 36 , 44 , 66 and the pumping mechanism 72 to rinse all the lines and the pump 26 of the cleaning solution 78 . The flexible divider 82 may be seen extending due to the inflow of used cleaning solution 80 and the fluid rinse within the area vacated by the unused cleaning solution 78 , refer to FIG. 8B The control unit 30 may alert the consumer via the beverage dispenser display 86 when the pump 26 should be cleaned or the consumer may independently initiate a cleaning cycle for the pump 26 pressing the control button 84 associated with initiating a cleaning cycle.
Thus, a beverage dispenser which provides for easy and convenient cleaning has been disclosed.
The invention has been shown and described above with the preferred embodiments, and it is understood that many modifications, substitutions, and additions may be made which are within the intended spirit and scope of the invention. The present invention is not to be limited to any specific embodiment described herein.
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A method of using a refrigerator with a beverage dispensing system is provided. A refrigerator having a refrigerator cabinet and a beverage dispenser is operatively connected to the refrigerator cabinet, receiving an indicia from a user to dispense a beverage received through a fluid line and fluid enhancement received through a fluid enhancement line, dispensing the beverage, and circulating a cleaning fluid through the fluid line or the fluid enhancement line for cleaning after dispensing.
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REFERENCE TO RELATED APPLICATIONS
[0001] This application relates to and claims the priority benefit of U.S. provisional application 62/325,467, filed on Apr. 21, 2016.
FIELD OF THE INVENTION
[0002] The present invention relates generally to methods for preparing meat products, and more specifically to methods for preparing uncooked meat products.
BACKGROUND OF THE INVENTION
[0003] Throughout the centuries, man has developed many different methods for preserving food products. Meat products are difficult to preserve safely without cooling, refrigeration or freezing.
[0004] “Biltong” is a Dutch name given to a variety of dried, cured meat, which originated in South Africa. Many different types of meat may be used in the preparation of Biltong, such as beef, game meats, ostrich fillets and the like. Typically, Biltong is prepared by cutting raw fillets of meat into strips, following the grain of the muscle, or flat pieces sliced across the grain. It is similar to beef jerky in that they are both spiced, dried meats. The typical ingredients, taste and production processes differ, the main difference being that biltong is sliced and then hung and dried. Typical production times are around a fortnight.
[0005] U.S. Pat. No. 6,383,549 B1 relates to a food snack comprising light, crispy wafers of dried minced food, typically dried minced meat and a process for making the food snack. The process includes the steps of dicing and mincing the food, feeding the food into a sausage casing, freezing the food in the casing, cutting the food into slices and drying the slices.
[0006] Chinese patent no. CN 103330236 A describes a new high-fat (30-50%) biltong product and preparation method thereof. Their disclosed biltong comprises pork, duck, fish meat, salt 4-7%, white sugar, gourmet powder, and other ingredients. Their process includes a short heating stage (1-2 minutes immersion in boiling water) followed by placing in the soil for 18-20 minutes. The invention further discloses a preparation method of the biltong; the preparation method comprises the following steps: selecting material, cleaning, dis-acidifying, sterilizing, adding condiment, and smudging. The biltong provided by the invention not only can conform to an eating habit of Chinese, but also can meet requirements of appearance, nutrition and safety of export to meat product, and meanwhile, the preparation method of the biltong is not limited by seasons, environment and temperature, so that industrialized and large-scale industrial production can be formed.
[0007] There thus remains a need to provide safe and time-efficient methods for preparing cured meat products.
SUMMARY OF THE INVENTION
[0008] It is an object of some aspects of the present invention to provide safe methods for preparing cured meat products.
[0009] It is another object of some aspects of the present invention to provide reduced-time methods for preparing cured meat products.
[0010] In some embodiments of the present invention, improved methods and cured products are provided for animal consumption.
[0011] In some embodiments of the present invention, improved methods and cured products are provided, fit for human consumption.
[0012] The present invention provides methods for preparing hygienic dried meat products and biltong hygienic dried meat products, the method comprising cutting uncooked meat into uncooked meat slices, immersing said meat slices in a vinegar solution for up to twenty minutes to form soaked meat slices, air drying the soaked meat slices for less than seventy two hours to form the biltong hygienic dried meat product having at least 100,000 fold less microbes than the uncooked meat.
[0013] The present invention will be more fully understood from the following detailed description of the preferred embodiments thereof, taken together with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The invention will now be described in connection with certain preferred embodiments with reference to the following illustrative figures so that it may be more fully understood.
[0015] With specific reference now to the figures in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of the preferred embodiments of the present invention only and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the invention. In this regard, no attempt is made to show structural details of the invention in more details than is necessary for a fundamental understanding of the invention, the description taken with the drawings making apparent to those skilled in the art how the several forms of the invention may be embodied in practice.
[0016] In the drawings:
[0017] FIG. 1 is a simplified flow chart of a method for preparing a meat product, in accordance with an embodiment of the present invention.
[0018] FIG. 2 is a simplified flow chart of a method for preparing a meat product from a mixture of minced or emulsified meat with other ingredients, in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0019] In the detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be understood by those skilled in the art that these are specific embodiments and that the present invention may be practiced also in different ways that embody the characterizing features of the invention as described and claimed herein.
Raw Material Handling and Storing
[0020] The raw materials may include one or more of:
[0021] a. Duck
[0022] b. Water Buffalo
[0023] c. Lamb
[0024] d. Beef
[0025] e. Kangaroo
[0026] f. Other type of animal meat
[0027] Meat can be processed either fresh or frozen and in the form of solid meat, ground meat, or emulsified meat.
[0028] Reference is now made to FIG. 1 , which is a simplified flow chart 100 of a method for preparing a meat product from solid meat, in accordance with an embodiment of the present invention.
[0029] In a first cutting step 102 , a meat product is cut into slices.
[0030] When processing any of the meat (called herein “materials”) any exterior vacuum seal bags and any other packaging that the material is delivered in are removed.
[0031] When processing any of the beef, buffalo, kangaroo and or lamb, most or all of the skin, fat, sinew, cartilage, veins, bones and any other tissue that is not muscle meat is removed and disposed of. This should preferably leave only muscle meat, but at the same time one should exercise best efforts to reduce any loss or waste of actual muscle meat during the cleaning process. Alternatively, some fat tissue can be left without being removed pre-drying. In this case, the final outcome of the drying process may depend on the type of animal meat. For example, beef fat will likely solidify under room temperature while lamb fat will likely remain liquefied or semi-liquefied under room temperature. A person skilled in the art should be able to determine how much fat to be left on the animal meat pre-drying depending on the meat type and desired outcome.
[0032] Thereafter, in cutting step 102 , the muscle meat is cut into steak slices. According to some embodiments, these are thin slices. According to one embodiment, the slices are no thicker or thinner than (three eights) 0.375 inches or (nine and a half) 9.525 millimeters with an allowable tolerance of 2% plus or minus.
[0033] According to another embodiment the slices are from (¼) inches or 0.635 centimeters thick up to three eights (⅜) of an inch or 0.952 centimeters with an allowable tolerance of no more than 2% plus or minus.
Duck Breast and Tenderloin
[0034] Duck will either arrive as duck breast with or without skin or duck tenderloin.
[0035] If received as duck tenderloin, no cleaning or further cutting is necessary as the desired sizes are already satisfied.
[0036] If the duck arrives as duck breast the breast may or may not contain skin, if the breast contains skin then the skin and any sinew or fat is removed from the breast.
[0037] The breast is then sliced in half lengthwise (butterfly) effectively creating two breasts.
[0038] Thereafter, in cutting step 102 , the muscle meat is cut into steaks slices.
[0039] According to some embodiments, these are thin slices. According to one embodiment, the slices are no thicker or thinner than 0.564 inches or 14.32 millimeters with an allowable tolerance of 2% plus or minus.
[0040] When processing kangaroo meat or other types of meat that arrive in the form of trim (trim is considered to be off cuts that are typically collected and packaged as bulk in 5-25 kilo bags or boxes), the meat must be frozen and then cut into steak slices that are no thicker or thinner than (three eights) 0.375 inches or (nine point five two five) 9.525 millimeters with an allowable tolerance of 2% plus or minus.
[0041] In an immersing step 104 , the cut slices are immersed in an aqueous solution. According to some embodiments, the aqueous solution is an acidic solution.
[0042] According to some further embodiments, the aqueous solution is a vinegar solution.
[0043] According to some further embodiments, the aqueous solution is a 5% acid vinegar solution. The vinegar solution may be any commercially available vinegar solution, such as apple cider vinegar, wine vinegar, malt vinegar, other types of vinegar, acetic acid solution and combinations thereof.
[0044] According to some further embodiments, the aqueous solution is a 5% apple cider vinegar solution. The apple cider is selected for its taste, smell, and nutritional value. However, other types of vinegar can be used.
[0045] According to some further embodiments, once all of the meat is sliced or reduced down to size, then it is treated with only apple cider vinegar which is no less than a 5% acidity level.
[0046] There is provided enough apple cider vinegar to cover all of the meat leaving no meat exposed to the outside elements, where the meat is completely submerged underneath the vinegar.
[0047] The vinegar is discarded after one use. Each batch of meat requires a new batch of vinegar further insuring that the acidity level is maintained at no more or less than 5%.
[0048] The meat slices are immersed for at least ten minutes, at least fifteen minutes, at least 18 minutes or up to twenty minutes. The meat slices should not be removed from the vinegar for any time before 15 minutes have passed and should not be left to soak in the vinegar for more than 20 minutes. Soaking the slices for more than twenty minutes may leave a residual smell therein.
[0049] The soaked slices are then dried in a drying step 106 . Various options may be used for drying, including hanging laying to dry, air drying, sun drying or combinations thereof.
[0050] For example, the soaked slices may be placed on a stainless steel baking sheet with holes punctured in the baking sheet allowing enough air flow to reach at least 95% of the meat. Alternatively, the soaked slices may be hung individually on meat hooks. Each piece of meat shall not touch another and shall maintain enough space between each piece where there is enough space for proper airflow to pass between each individual piece.
[0051] Once the soaked meat has properly been hung or placed on a baking sheet or rack the meat shall be placed in a room where the temperature shall be maintained at within a temperature range of 28-45 degrees Celsius, or preferably 28-33 degrees Celsius. The humidity moisture level to be maintained under 40%, preferably, in the range of 25-35%, or more preferably, in the range of 30%-35% humidity.
[0052] The meat slices are left undisturbed under these drying conditions for no less than 40 hours and no more than 75 hours. More preferably, the drying time should be between 48-60 hours. After the time period has elapsed the meat slices are removed from the room and shall not be reintroduced into any temperature less than room temperature. The dried sliced meat is now considered to be a finished product, ready for packaging.
[0053] The dried product is tested in quality control for water activity, pH and bacterial count. The water activity in three different samples was found to be in the range of 0.45-0.70. The pH was found to be in the range of 5.0-5.5. The E. coli, Listeria monocytogenes and Salmonella counts were all zero (negative). The term “hygienic” herein is used to denote a product devoid of bacterial contamination.
[0054] The protein percent was found to be in the range of 65-85%. The fat content was found to be in the range of 3-25% and the moisture content (forced oven) was found to be in the range of 5-16% (all on a weight/weight basis).
[0055] In the case of minced meat the fat content may, according to some embodiments, be greater. For example, the protein percent may be in the range of 40-85% and the fat content may be in the range of 5-60%. Thus, the minced meat product may have a higher calorific value than the non-minced meat product. For example, the minced meat product may have a calorific value in the range of 4000-6000 Kcal/kg, whereas the non-minced meat product typically has a calorific value of 3000-5000 Kcal/kg.
[0056] In a packaging step, 108 , the dried sliced meat is packaged. In some cases, the dried sliced meat is removed off the baking sheets and/or the meat hooks using a pair of stainless talons. Optionally, using other cutting tools, the dried sliced meat is further cut down the product into pieces that are no smaller than 1 inch wide by 1 inch in length and no larger than 2 inches wide by 2 inches in length. According to other embodiments, the pieces are at least 2 inches wide by 2 inches in length and no larger than 3 inches wide by 3 inches in length. And in other cases, the meat pieces are further cut down to smaller pieces, for example, to 9 mm slices to be used as bites for training small and older dogs. And yet in other cases, the meat pieces are further ground down to granules or particles to be used in applications such as cat treats.
[0057] All finished products shall not be reintroduced or come in to contact with raw meat or materials or tools that are or where used in the manufacturing of raw meat unless the materials or tools have been completely disinfected and now appear dry.
[0058] The cut down products shall then be packaged in each of its respective bags.
[0059] Kangaroo shall only be packaged in bags with the kangaroo label affixed to it.
[0060] Buffalo shall only be packaged in bags with the buffalo label affixed to it.
[0061] Beef shall only be packaged in bags with the beef label affixed to it.
[0062] Duck shall only be packaged in bags with the duck label affixed to it.
[0063] Lamb shall only be packaged in bags with the lamb label affixed to it.
[0064] Further, different packaging bags may be used to package the meat with different cuts or different product lines.
[0065] With an allowable tolerance of no more than 3.5%, the dried slice meat product is filled into bags, with products based on the weight located on the label on the upper right hand corner (“weight”). For example a 60 gram packaging cannot be filled with less than 60 grams of product however a 60 gram bag can be filled over the amount stated but not to exceed an allowable overage of 3.5% therefore not to exceed 62.1 grams of product on a 60 gram packaging.
[0066] In the event that the meat is processed as ground or emulsified, additional steps are taken to prepared the meat as shown in FIG. 2 . First, uncooked meat is ground, emulsified, or similarly processed to ground meat or meat pulp ( 201 ), then the meat is optionally mixed with any desired ingredients ( 202 ), including spices, seasonings, vegetables, cheese, other desirable additives or combinations of additives. Once the mix recipe is satisfactory, then an acidic solution is added to the mixture ( 203 ). The amount of acidic solution is below 30% by weight in the final mixture. In one embodiment, an apple cider vinegar of 5% acidity is added below 20% by weight. Then the mixture is frozen to blocks ( 204 ). The frozen blocks of meat or meat mixture then are processed including cutting to slices ( 205 ) and drying the slices( 206 ) similar to the process with solid animal meat.
Further Packaging
[0067] Oxygen Absorbers:
[0068] According to some embodiments, the purchaser shall deliver oxygen absorbers, each box contains 75 bags and each bag contains 20 absorbers, this combination shall vary depending on what combination the supplier sends to the purchaser.
[0069] The absorbers have a limited shelf life once the bag is open and the absorbers are exposed to the air.
[0070] Sealing:
[0071] Each package is sealed individually with a seal bar using an impulse sealer or a heat sealer, the location of the seal is across the top of the packaging directly above a zipper of the packaging and underneath of the hanging hole, and the manufacturer will make sure each packaging is properly sealed.
[0072] The references cited herein teach many principles that are applicable to the present invention. Therefore the full contents of these publications are incorporated by reference herein where appropriate for teachings of additional or alternative details, features and/or technical background.
[0073] It is to be understood that the invention is not limited in its application to the details set forth in the description contained herein or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Those skilled in the art will readily appreciate that various modifications and changes can be applied to the embodiments of the invention as hereinbefore described without departing from its scope, defined in and by the appended claims.
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The present invention provides methods for preparing hygienic dried meat products and biltong hygienic dried meat products, the method includes cutting uncooked meat into uncooked meat slices, immersing said meat slices in a vinegar solution for up to twenty minutes to form soaked meat slices, air drying the soaked meat slices for less than 72 hours to form the biltong hygienic dried meat product having at least 100,000 fold less microbes than the uncooked meat.
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FIELD OF THE INVENTION
The present invention pertains to a modular bridge section for a floating bridge according to the preamble of the principal claim.
BACKGROUND OF THE INVENTION
A bridge section with one detachable lower chord structure each in the area of a side wall of a box girder has been known from WO 93/21390. The arrangement is designed in this way in order for the lower chord structure to be able to be detached in a simple manner from the box girder by pulling out laterally the short horizontal connecting pin.
It is disadvantageous that the lower chord structure is subject not only to tension, but also to bending. In addition, the connecting pins of the lower chord structure are subject to both horizontal and vertical forces. The horizontal forces are generated from the tensile forces, which are introduced into the coupling elements. The vertical forces are generated from the difference in height between the connections at the box girder and the positions of the coupling holes. These vertical forces are superimposed by transverse forces arising from the load on the bridge.
In addition, it must be pointed out that this bridge section has a detachable lower chord structure for a bridge on two supports and also an integrated lower chord structure. When this bridge section is used for a floating bridges, the first-named lower chord structure shall be removed in order to reduce the redundant weight.
SUMMARY AND OBJECTS OF THE INVENTION
The primary object of the present invention is to design a lower chord structure, specially for bridge sections of floating bridges, such that the connections of such a lower chord structure at the box girder are designed optimally.
The lower chord structure shall always remain in the bridge section and shall not be detachable, as in the bridge module according to the above-described state of the art.
The object described is accomplished according to the claims in a lower chord structure of the type described in the introduction by the lower chord structure being mounted floatingly, i.e., flexibly, in the loaded state only between the end stops, which are arranged in the vicinity of the coupling elements.
The advantages achieved by the present invention are mainly that only the difference between the two tensile forces in the lower chord structure are introduced into the box girder via one of the two end stops.
This end stop transmitting the differential force is located at the end of the lower chord structure, namely, at the opposite end, where the stronger tensile force is introduced into the lower chord structure.
Furthermore, provisions are made according to one embodiment of the present invention for the end stop
to be arranged vertically,
to be able to be designed as a cylindrical bolt,
or to have a square shaft with two round pins,
and for it to be preferably mounted in both blind holes in the box girder
and in a clamp, wherein the clamp is rigidly connected to the box girder.
It is achieved as a result that
1. the lower chord structure is not subject to bending, because the force is transmitted in the end stops via a double-shear connection;
2. no water can enter the interior of the box girder via a bolt clearance and pin clearance that may have developed when the bridge section is used in a floating bridge, and
3. the clamps have not only a load transmission function, but they also secure the cylindrical end stop against falling out at the same time.
It is preferably also provided according to the present invention that the broad side of the rectangular beam tie is arranged in the plane of the bottom of the box girder.
The present invention offers a possibility of designing the bottom of the box girder such that the tensile forces introduced by the vertical end stops are locally transmitted in the area of the coupling elements only in the case of the arrangement of a lower chord structure between the longitudinal side walls. These tensile forces are weaker than the maximally occurring tensile forces in the lower chord structure. The rest of the area of the box girder bottom now has only the task of keeping the box girder water-tight when it is used as a floating bridge section and no additional fillings are arranged in the interior of the box girder.
The use of the modular bridge section according to the present invention is not limited to the use in floating bridges. It may, of course, also be used for bridges on supports while maintaining the features according to the present invention.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which preferred embodiments of the invention are illustrated.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a view of a longitudinal section of a box girder with cylindrical end stops for the lower chord structure;
FIG. 2 is a horizontal view along the box girder bottom on the lower chord structure according to FIG. 1;
FIG. 3 is a longitudinal sectional view of a box girder with square, shaft-like stops for the lower chord structure;
FIG. 4 is a horizontal view along the box girder bottom on the lower chord structure according to FIG. 3.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings, FIG. 1 shows a vertical longitudinal section of a box girder 1 with a deck 2 that is load-bearing for vehicular travel, with side walls 3 and with a lower chord structure 5 under the bottom 4 of the box girder 1. The chord structure having means in the material of the chord structure for transmitting tensile forces.
Cylindrical end stops 6, 6' are arranged in the vicinity of the coupling elements 7, 7' of the lower chord structure 5. The rectangular beam tie 8, which connects the coupling elements 7, 7' to one another, has one or more elongated holes 9, 9' in the area of the coupling elements 7, 7'. A cylindrical end stop 6, 6' is passed through each elongated hole 9, 9'. The end stops 6, 6' are mounted in the box girder 1 and in a clamp 11, 11' fastened to the box girder 1, preferably in blind holes 13, 13' in the box girder 1 and in holes 14, 14' in the clamp 11, 11'. It is achieved as a result that no bending moments develop in the lower chord structure 5 due to the double-shear connection and the wall of the hole in the connection structure is kept low.
The blind holes 13, 13' have a larger diameter than the hole 14, 14' in the clamp 11, 11'. The cylindrical stop 6, 6' is mounted captively as a result.
An intended clearance between the box girder 1 and the clamps 11, 11', which makes possible a free longitudinal movement of the rectangular beam tie 8 in the loaded state, is recognizable.
To make possible a horizontal displacement of the coupling elements 7, 7', which is equal to the elongation of the beam tie 8, the horizontal bolts 12, 12' are arranged above the coupling elements 7, 7' in the longitudinal direction of the beam tie 8. The bolts 12, stops 6, holes 13 and clamps 11 form a mounting means for creating a floating or sliding connection between the chord structure and the box girder in a loaded state of the chord structure. The mounting means transmits a difference in tensile forces at ends of said chord to the box girder.
FIG. 2 shows a horizontal view along the box girder bottom 4 on the lower chord structure 5 in the unloaded state. It can be recognized how the cylindrical end stops 6, 6' are now in contact with the inner surfaces 10, 10' of the elongated holes 9, 9'. The elongated holes 9, 9' are at least as long as the maximum elongation of the beam tie 8 at the maximally occurring tensile force in the lower chord structure 5.
FIG. 3 shows a vertical longitudinal section of a box girder 1' with a deck 2' that is load-bearing for vehicular travel, with side walls 3' and with a lower chord structure 5' under the bottom 4' of the box girder 1'.
End stops 6", 6'" are arranged at the transition point 15, 15' between the coupling element 7", 7'" and the beam tie 8' in the vicinity of the coupling elements 7", 7'" of the lower chord structure 5'.
The broad side B z of the preferably rectangular beam tie 8' is smaller than the broad side B k of the coupling elements 7", 7'". In the unloaded state of the lower chord structure 5', the projecting surfaces 18, 18' of the two coupling elements 7", 7'" are in contact with the square shafts 16 of the end stops 6", 6'", which shafts are located on both sides of the beam tie 8'. Each square shaft 16 has two round pins 17, 17', which are mounted in the box girder 1' as well as in a clamp 11", 11'" connected to the box girder 1'. The advantage of this mounting of the pins is that the end stops 6", 6'" are always in contact with the projecting surfaces 18, 18' and thus they generate weak contact pressures.
The round pins 17 of the end stops 6", 6'" are mounted in respective blind holes 13", 13'" of the box girder 1', and the round pins 17 are mounted in holes 14", 14'" of the clamps 11", 11'". The end stop 6", 6'" is secured against falling out by the square shaft 16.
An intended clearance between the box girder 1' and the clamps 11", 11'", which makes possible a free longitudinal movement of the rectangular beam tie 8' in the loaded state, is clearly recognizable.
Horizontal displacement of the coupling elements 7", 7'", which is equal to the elongation of the beam tie 8', is possible due to the arrangement of the horizontal bolts 12", 12'" above the coupling elements 7", 7'" in the longitudinal direction of the beam tie 8'.
FIG. 4 shows a horizontal view along the box girder bottom 4' on the lower chord structure 5' in the unloaded state. It can be recognized that each of the two end stops 6", 6'" arranged on both sides of the beam tie 8' is arranged in the immediate vicinity of the transition point 15, 15' of the coupling element 7", 7'" with the beam tie 8'.
The two projecting surfaces 18, 18' of the coupling element 7, 7' are in contact with the square shafts 16, 16' of the end stops 6", 6'" in the unloaded state of the lower chord structure 5'.
While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.
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A modular bridge section including one or more box girders, wherein at least one box girder 1, 1' is equipped with at least one lower chord structure 5, 5', which is mounted floatingly at or in the box girder 1, 1' in the loaded state only between the end stops 6, 6', 6", 6'", which are arranged in the vicinity of the coupling elements 7, 7, 7", 7'".
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application relates to and claims the benefit and priority to Spanish Patent Application No. P201230068, filed Jan. 18, 2012.
FIELD
[0002] The present invention relates to an assistance device for operating a pedal of a motor vehicle and to a pedal comprising the assistance device.
BACKGROUND
[0003] Pedals comprising assistance devices which aid in improving the effort which a driver must exert on the shoe of a pedal for operating a servobrake or a clutch are known in the automotive industry.
[0004] U.S. Publication No. 2005/0252334A1 describes a clutch pedal assembly comprising a spring and a cam fixed to a support on which the pedal acts, such that the cam, having a specific profile, compresses the spring during the stroke of the pedal.
[0005] European Publication No. EP480602A1 describes a pedal having an arm, the end of which presses a leaf spring element as it moves between the resting position and the clutch or active position.
[0006] Spanish Patent No. ES20205415T3 describes an assistance device comprising a profile integral with the pedal and delimited by an angular sector cooperating with a rolling means suitable for moving according to a substantially horizontal direction through the action of an elastic means.
SUMMARY OF THE DISCLOSURE
[0007] According to some implementations an assistance device is provided that comprises a profile coupled to an arm of the pedal, elastic means coupled to a support of the pedal and rolling means acting on the profile operated by the elastic means, exerting additional force on the arm of the pedal, between a resting position of the pedal and an active position of the pedal. The assistance device further comprises a lever which is arranged pivotally coupled to the support and at one of the ends of which the rolling means and the elastic means are coupled.
[0008] The elastic means exert stress on the lever, the stress being transmitted through the rolling means against the profile. The arrangement of the elastic means with respect to the rolling means reduces, or otherwise minimizes contact forces among the various components to reduce friction that can result in high hysteresis which can be seen in the force necessary for moving the pedal.
[0009] The configuration of the assistance device also reduces the number of necessary elements.
[0010] These and other advantages and features will be more evident in view of the figures and the detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 shows a perspective view of a pedal assembly of a motor vehicle with an assistance device according one implementation.
[0012] FIG. 2 shows another perspective view of the pedal assembly shown in Figure
[0013] FIG. 3 shows an exploded view of the pedal assembly shown in FIG. 1 .
[0014] FIG. 4 shows a side view of the pedal assembly shown in FIG. 1 in an initial or resting position.
[0015] FIG. 5 shows a side view of the pedal assembly shown in FIG. 1 in a position with zero assistance force.
[0016] FIG. 6 shows a side view of the pedal assembly shown in FIG. 1 in a position with maximum assistance force.
[0017] FIG. 7 shows a side view of the pedal assembly shown in FIG. 1 in a position with residual assistance force.
[0018] FIG. 8 shows a diagram of the force generated on a shoe of the pedal assembly shown in FIG. 1 according to one implementation.
[0019] FIG. 9 shows a perspective view of a profile according to one implementation.
[0020] FIG. 10 shows a section of the profile shown in FIG. 9 according to plane IX.
[0021] FIG. 11 shows a perspective view of a profile according to another implementation.
[0022] FIG. 12 shows a section of the profile shown in FIG. 11 according to plane XII
[0023] FIG. 13 shows a diagram of the force generated on a shoe of the pedal assembly shown in FIG. 1 with the profile shown in FIG. 11 .
[0024] FIG. 14 shows a perspective view of a profile according to another implementation.
[0025] FIG. 15 shows a section of the profile shown in FIG. 14 according to plane XIV.
[0026] FIG. 16 shows a diagram of the force generated on a shoe of the pedal shown in FIG. 1 with the profile shown in FIG. 14 .
[0027] FIG. 17 shows a perspective view of a profile according to another implementation.
[0028] FIG. 18 shows a section of the profile shown in FIG. 17 according to plane XVII.
[0029] FIG. 19 shows a diagram of the force generated on a shoe of the pedal shown in FIG. 1 with the profile shown in FIG. 17 .
DETAILED DESCRIPTION
[0030] FIGS. 1 to 7 show a clutch or brake pedal 1 adapted to a motor vehicle which comprises a support 20 , an arm 13 pivotal with respect to the support 20 , and a shoe 14 arranged at one end of the arm 13 , operable by a user. The pedal 1 further comprises a non-depicted actuating rod which is arranged coupled to the arm 13 through a coupling 15 and which transmits an activation force F,F′,F″ exerted on the shoe 14 by the driver, to a non-depicted actuator, primarily a servobrake or a clutch.
[0031] According to one implementation the pedal 1 comprises a shaft 50 through which the arm 13 is coupled to the support 20 , the shaft 50 traversing the support 20 through holes 21 , shown in FIG. 3 , and an end 11 of the arm 13 , the arm 13 being pivotal between an initial or resting position shown in FIG. 4 and a final active position or a position with the operated pedal shown in FIG. 7 .
[0032] The pedal 1 comprises an assistance device 10 which cooperates in transmitting force to the actuator via the arm 13 such that from a position of the arm 13 with respect to the support 20 , called a position with zero force shown in FIG. 5 and depicted by means of point B in a diagram of force/movement shown in FIG. 8 , the activation force F′ which must be exerted by the driver on the shoe 14 to further move the arm 13 and operate the actuator is less than the force which would have to be exerted if the pedal 1 did not include the assistance device 10 .
[0033] The assistance device 10 is arranged articulated to the arm 13 and to the support 20 . The assistance device 10 comprises a profile 30 coupled to the arm 13 , elastic means 35 coupled to the support 20 , rolling means 45 , 46 adapted for contacting profile 30 and a lever 40 which is arranged pivotally coupled to the support 20 and at one of the ends of which the rolling means 45 , 46 and the elastic means 35 are coupled. The rolling means 45 , 46 act on the profile 30 pressed by the lever 40 which is in turn operated by the elastic means 35 exerting additional force on the arm 13 during the stroke of the arm 13 between the resting position and the active position.
[0034] The lever 40 comprises two sets of substantially parallel surfaces 41 , 43 at each end. The lever 40 includes a coupling 42 extending from each surface 41 in a manner substantially orthogonal to the parallel surfaces 41 at one of the ends. The coupling 42 extends outwardly from the lever 40 . In the implementations shown in the figures, the coupling 42 has a substantially cylindrical geometry.
[0035] The support 20 in turn comprises two substantially parallel walls 24 each of which comprises a housing 22 , 23 wherein the respective coupling 42 of the lever 40 is housed, configuring a pivoting attachment between the lever 40 and the support 20 . The housing 22 , 23 comprises a first part 23 with a substantially circular section and a second part 22 continuous to the first part 23 , communicating the first part 23 with the outside, allowing the insertion of the coupling 42 in the first part 23 . The second part 22 has a width less than the diameter of the first part 23 , allowing, on one hand, easily inserting the coupling 42 in the first part 23 and on the other hand, preventing the coupling 42 from being easily released from the support 20 once the lever 40 is coupled to the support 20 .
[0036] According to some implementations the lever 40 comprises, at the opposite end, a projection 44 which is arranged fixed on one of the parallel surfaces 43 arranged at said opposite end and through which the free end of the lever 40 is fixed to the support 20 through the elastic means. In the implementation shown, the projection 44 is substantially disc-shaped.
[0037] In some implementation the elastic means comprises a spring 35 , one of the ends 36 of which is arranged fixed to the support 20 and the other end 37 to the lever 40 . In the implementation shown, the spring 35 is a helical spring, in other implementations other elastic means may be used. In the implementations shown in the figures, the ends 36 , 37 of the spring 35 are substantially hook-shaped, being inserted in grooves 25 b , 44 b arranged respectively in an extension 25 of the support 20 and in the projection 44 coupled to the lever 40 . The grooves 25 b , 44 b extend perimetric to the extension 25 of the support 20 and to the projection 44 . The spring 35 is arranged forming an angle with respect to the lever 40 , said angle being in some implementations as close as possible to 90°, such that the spring 35 is prevented from generating high radial compression forces in the lever 40 , which may cause reactions and therefore friction in the coupling of the end 42 of the lever with the support 20 .
[0038] According to some implementations the rolling means comprises a wheel 45 which is arranged in contact with a rolling surface 32 of the profile 30 during the movement of the arm 13 . The rolling means may comprise at least one stop element 46 which extends continuously from a face of the wheel 45 and which laterally guides the movement of the wheel 45 along the rolling surface 32 together with a guide surface 33 of the profile 30 , preventing the accidental decoupling of the wheel 45 with respect to the rolling surface 32 . According to some implementations the stop element 46 is disc-shaped and is arranged coaxial to the wheel 45 .
[0039] In the implementations shown in the figures, the rolling means comprises two stop elements 46 each of which extends continuously from a face of the wheel 45 and coaxial to the wheel 45 . Likewise, the profile 30 comprises two guide surfaces 33 each of which extends continuously from the rolling surface 32 . The two guide surfaces 33 are arranged substantially parallel to one another and substantially orthogonal to the rolling surface 32 , as shown in FIG. 10 .
[0040] The projection 44 is arranged substantially coaxial to the rolling means. Therefore, the force exerted by the elastic means 35 is successfully transmitted as directly as possible to the rolling surface 32 , reducing losses by friction.
[0041] FIGS. 4 to 7 show the pedal 1 in different positions each of which corresponds respectively with points A, B, C and D depicted in FIG. 8 showing the reaction force generated by the assistance device 10 on the shoe 14 depending on the movement of the arm 13 of the pedal 1 .
[0042] Therefore, the pedal 1 first starts from an initial position shown in FIG. 4 in which the spring 35 pulls the lever 40 such that the lever 40 exerts pressure on the wheel 45 against the rolling surface 32 of the profile 30 integral with or otherwise removably coupled to the arm 13 of the pedal 1 . From this position, depicted in FIG. 8 by means of point A, and to the position with zero force shown in FIG. 5 and depicted in FIG. 8 by means of point B, the driver must exert a progressive force F on the shoe 14 in order to operate the actuator. During the stroke between both positions, the force F exerted on the shoe 14 must be greater than the case in which the pedal 1 does not include an assistance device 10 because it must overcome the moment generated by the force F 1 exerted by the wheel 45 on the profile 30 .
[0043] In the position with zero force shown in FIG. 5 , the assistance device 10 does not exert any reaction on the arm 13 of the pedal 1 , the force F′ exerted by the driver on the shoe 14 being similar to the case in which the pedal 1 does not include an assistance device 10 because the force F 2 exerted by the wheel 45 on the profile 30 does not generate reaction in the shoe 14 .
[0044] FIG. 6 shows the pedal 1 in a position with maximum reaction force which corresponds with point C of FIG. 8 . Therefore, from the position with zero reaction force to the position with maximum reaction force, the driver must exert a force F″ on the shoe 14 in order to operate the actuator, the force F″ being less than the force which must be exerted by the driver in the event that the pedal 1 does not include the assistance device 10 because the force F 3 exerted by the wheel 45 on the profile 30 generates a reaction favoring the movement of the shoe 14 .
[0045] Finally, FIG. 7 shows the pedal 1 in a position with residual reaction force which corresponds with point D of FIG. 8 . From the position with maximum reaction force, the driver must exert a force F″′ on the shoe 14 in order to operate the actuator, the force F″′ being gradually greater than the force F″ which must be exerted in the position with maximum reaction force but less than the force which must be exerted in the event that the assistance device 10 is not included because the force F 4 exerted by the wheel 45 on the profile 30 generates a reaction favoring the movement of the shoe 14 , even though it is less than that in the preceding movement.
[0046] The rolling surface 32 of the profile 30 has a curved trajectory suitable for generating forces F 1 , F 2 , F 3 and F 4 for a desired operation of the assistance device 10 .
[0047] Different profiles 30 ; 60 ; 70 ; 80 such as those shown in FIGS. 8 to 19 with their respective characteristic curves, can be used for different types of vehicles and drives depending on the operation requirements of the pedal 1 . Different performances of the pedal 1 adapted to each individual vehicle/drive can thus be obtained by just replacing the profile 30 ; 60 ; 70 ; 80 , keeping the rest of the parts common. In the implementation shown in FIGS. 14 to 16 , the assistance device 10 acts before the assistance device 10 of FIGS. 4 to 8 so that the maximum reaction force of the assistance device 10 is obtained in a shorter stroke of the arm 13 , whereby the driver can tell sooner that he/she must exert less effort on the shoe 14 and in the final sector of the stroke of the arm 13 , the assistance device 10 does not act in a manner which can be perceived by the user, which can be beneficial in certain vehicles and drives.
[0048] FIGS. 11 to 13 show an implementation of the profile 60 of the assistance device 10 which is characterized in that, throughout the entire stroke of the arm 13 , the force exerted by the driver on the shoe 14 is greater than that which would be necessary if the pedal 1 did not include an assistance device 10 . The assistance device 10 comprising the profile 60 causes said arm 13 to tend to return to the resting position throughout the entire stroke of the arm 13 .
[0049] FIGS. 17 to 19 show another implementation of the profile 80 of the assistance device 10 in which the force exerted by the driver on the shoe 14 is greater than that which would be necessary if the pedal 1 did not include an assistance device 10 only throughout a first sector of the stroke of the arm 13 , whereas subsequently, the assistance device 10 does not act in a manner which can be perceived by the user.
[0050] In order to obtain an optimized, readily interchangeable pedal 1 , the pedal 1 can be adapted to any requirement for use by modifying the profile. To that end, the pedal 1 may comprise a profile 30 ; 60 ; 70 ; 80 which is arranged removable to the arm 13 of the pedal 1 , said profile 30 ; 60 ; 70 ; 80 being readily interchangeable. To that end, the profile 30 ; 60 ; 70 ; 80 may comprise a housing 34 ; 64 ; 74 ; 84 collaborating with a projection 12 protruding from the arm 13 of the pedal 1 for fixing the profile 30 ; 60 ; 70 ; 80 to the arm 13 . The projection 12 shown in FIG. 3 has a substantially T-shaped cross-section. The projection 12 may comprise a first substantially rectangular part 12 a, defined by width d 1 , extending continuously to the arm 13 and a second part 12 b with a substantially rectangular section defined by width d 2 and continuous to the first part 12 a. The width d 1 of the first part 12 a is less than the width d 2 of the second part 12 b. The housing 34 ; 64 ; 74 ; 84 of the profile 30 ; 60 ; 70 ; 80 extends longitudinally along the profile 30 ; 60 ; 70 ; 80 , communicating with the outside through a groove 31 ; 61 ; 71 ; 81 having a width d 3 ;d 3 ′;d 3 ″;d 3 ″′, shown in FIGS. 9 , 12 , 15 and 18 , greater than the width dl of the first part 12 a of the projection 12 . The housing 34 ; 64 ; 74 ; 84 has a substantially rectangular section defined by width d 4 ;d 4 ′;d 4 ″;d 4 ″′ such that the second part 12 b of the projection 12 is tightly housed in the respective housing 34 ; 64 ; 74 ; 84 .
[0051] Elements 62 ; 72 ; 82 correspond in a like manner to element 32 described above. Elements 63 ; 73 ; 83 correspond in a like manner to element 33 described above.
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A pedal assembly having an assistance device. In some implementations the assistance device comprises a profile fixed to the arm of a pedal, the arm of the pedal being pivotally coupled to a support. The profile includes an elongate curved surface that is acted upon by a spring-actuated lever attached to the support. In operation as the pedal arm is moved between a rest position and one or more active positions, the lever applies a force to the arm through the profile by acting upon on one or more portions of the elongate curved surface, the direction of the force applied to the arm being dependent upon the portion of the elongate curved surface being acted upon by the lever.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates in general to offshore drilling and production equipment, and in particular to a subsea well system for monitoring the pressure in a non-producing string of casing through the completion system.
2. Description of the Prior Art
A subsea well that is capable of producing oil or gas will have a conductor housing secured to a string of conductor pipe which extends some short depth into the well. A wellhead housing lands in the conductor housing. The wellhead housing is secured to an outer or first string of casing, which extends through the conductor to a deeper depth into the well. Depending on the particular conditions of the geological strata above the target zone (typically, either an oil or gas producing zone or a fluid injection zone), one or more additional casing strings will extend through the outer string of casing to increasing depths in the well until the well is cased to the final depth. Each string of casing is supported at the upper end by a casing hanger. The casing hanger lands in and is supported by the wellhead housing.
In some shallow wells and in some fluid injection wells, only one string of casing is set within the outer casing. Where only one string of casing is set within the outer casing, only one casing hanger, the production casing hanger, is landed in the wellhead housing. In this case, the space between the outer or first string of casing and the second or production string of casing is isolated by a casing hanger packoff that seals between the wellhead housing and the production casing hanger.
The more typical case is where multiple strings of casing are suspended within the wellhead housing to achieve the structural support for the well to the depth of the target zone. Where multiple strings of casing must be set within the outer casing, multiple casing hangers are landed in the wellhead housing, each set above the previous one in the wellhead housing. Between each casing hanger and the wellhead housing, a casing hanger packoff is set to isolate each annular space between strings of casing. The last string of casing extends into the well to the final depth, this being the production casing. The strings of casing between the outer casing and the production casing are intermediate casing strings.
When drilling and running strings of casing in the well, it is critical that the operator maintains pressure control of the well. This is accomplished by establishing a column of fluid with predetermined fluid density inside the well. During drilling operations, this fluid is circulated down into the well through the inside of the drillstring out the bottom of the drillstring and back to the surface. This column of density-controlled fluid balances the downhole pressure in the well. When setting casing, the casing is run into the pressure balanced well. A blowout preventer system is employed during drilling and running strings of casing in the well as a further safety system to ensure that the operator maintains pressure control of the well. The blowout preventer system is located above the wellhead housing by running it on drilling riser to the wellhead housing.
When each string of casing is suspended from the casing hanger in the wellhead housing, a cement slurry is flowed through the inside of the casing, out of the bottom of the casing, and back up the outside of the casing to a predetermined point. An open fluid communication passage in the casing hanger leading from the casing annulus to the casing interior would adversely affect the flow path of the cement slurry. This could also cause well pressure control problems for the operator under certain conditions.
In a subsea well capable of producing oil or gas, the production fluids flow through perforations made in the, production casing at the producing zone. A string of tubing extends to the producing zone within the production casing to provide a pressure-controlled conduit through which the well fluids are produced. At some point above the producing zone, a packer seals the space between the production casing and the tubing to ensure that the well fluids flow through the tubing to the surface. The tubing is supported by a tubing hanger assembly that lands and locks above the production casing hanger, either in the wellhead housing, in a tubing hanger spool or in a horizontal or spool tree (further described below).
Subsea wells capable of producing oil or gas can be completed with various arrangements of the production control valves in an assembly generally known as a tree. Trees with the arrangement of production control valves located vertically above and in line with the production tubing are generally called christmas trees. Trees with the arrangement of production control valves offset from the production tubing are generally called horizontal or spool trees.
For wells completed with a christmas tree, the tubing hanger assembly lands in the wellhead housing above the production casing hanger. Alternatively, the tubing hanger assembly lands in a tubing hanger spool, which tubing hanger spool is landed and locked to the wellhead housing. For wells completed with a horizontal or spool tree, the horizontal tree locks and seals on the wellhead housing. A tubing hanger assembly locks and seals in the horizontal tree. When either a tubing hanger spool or horizontal tree is located on the wellhead housing, the blowout preventer system is landed on the tubing hanger spool or horizontal tree, respectively.
The tubing hanger assembly in each of the above subsea well systems normally has a flow passage for communication with the annulus surrounding the tubing. This passage allows for monitoring pressure above the packer between the interior of the production casing and the interior of the tubing. In some cases the well can also be produced through this annulus flow passage. Virtually all producing wells monitor pressure in the annulus flow passage between the interior of the production casing and the interior of the tubing.
A sealed annulus locates between the production casing and the next larger string of casing. Normally there should be no pressure in the annulus between the production casing and the next larger string of casing, because the annular space between the production casing and the next larger string of casing is ordinarily cemented at its lower end and sealed with a packoff at the production casing hanger end. Pressure build up in the annulus between the production casing and the next larger string of casing could collapse a portion of the production casing, compromising the structural and pressure integrity of the well. Monitoring pressure in the annulus between the production casing and the next larger string of casing of a subsea well is shown in patents, however, it is not done commercially to applicant's knowledge. Improvements are desired.
SUMMARY OF THE INVENTION
In a subsea well with a tree assembly including either a tubing hanger spool or a horizontal tree, the annulus pressure between the production casing and the next larger string of casing is monitored through communication passages external to the tubing hanger. A communication passage extends through the production casing hanger from the exterior of the production casing hanger below the casing hanger packoff to an outlet in the interior of the production casing hanger. A port closure sleeve threads to the interior of the production casing hanger.
The port closure sleeve seals on both sides of the communication passage outlet in the interior of the production casing hanger. With the port closure sleeve located as described, the communication passage between the exterior of the production casing hanger and the bore of the production casing is isolated. The port closure sleeve as designed can be removed after the tree assembly is installed. After the tree assembly is installed, a lower end of a tubing hanger orientation sleeve mates in the interior of the production casing hanger. The tubing hanger orientation sleeve seals on its exterior surface with the interior of the production casing hanger at a point below the communication passage outlet in the interior of the production casing hanger. The tubing hanger orientation sleeve lands in the tree assembly. The tubing hanger orientation sleeve seals on its exterior surface with the interior of the tree assembly. A space between the tubing hanger orientation sleeve and the wellhead housing is created through which casing annulus pressure can communicate with a communication passage in the tree assembly.
The communication passages communicate pressure in the annulus of the production casing to the exterior of the tree assembly. A communication line extends to monitoring equipment at the surface for monitoring the pressure in the annulus of the production as described.
In one embodiment, the tree assembly includes as part of its assembly a horizontal tree. The horizontal tree lands on the wellhead housing. A tubing hanger orientation sleeve lands in the horizontal tree and mates to the interior of the production casing hanger. The tubing hanger orientation sleeve isolates a space between the exterior of the tubing hanger orientation sleeve and the interior of the wellhead housing to link the communication passage in the production casing hanger with the communication passage in the horizontal tree.
In another embodiment, the tree assembly includes as part of its assembly a tubing hanger spool. The tubing hanger spool lands on the wellhead housing, with the tree mounted to the upper end of the tubing hanger spool. The tubing hanger orientation sleeve lands in the tubing hanger spool and mates to the interior of the production casing hanger. In this configuration, the tubing hanger orientation sleeve is not necessarily oriented to the tubing hanger spool, although it may be. The tubing hanger orientation sleeve isolates a space between the exterior of the tubing hanger orientation sleeve and the interior of the wellhead housing to link the communication passage in the production casing hanger with the communication passage in the tubing hanger spool. The communication passage in the tubing hanger spool communicates pressure to the exterior of the tubing hanger spool. A communication line extends to monitoring equipment at the surface for monitoring the pressure.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a sectional view of a subsea wellhead assembly constructed in accordance with this invention, shown prior to installation of a tree assembly.
FIG. 2 is an enlarged sectional view of a portion of the subsea wellhead assembly of FIG. 1 .
FIG. 3 is a sectional view of a first embodiment of a subsea well assembly constructed in accordance with this invention.
FIG. 4 is a sectional view of a second embodiment of a subsea well assembly constructed in accordance with this invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, one configuration for the subsea wellhead assembly includes a conductor housing 11 , which will locate at the sea floor. Conductor housing 11 is a large tubular member that is secured to a string of conductor pipe 13 . Conductor pipe 13 extends some short depth into the well and is typically 30 or 36 inches in diameter.
A wellhead housing 15 lands in the conductor housing 11 . Wellhead housing 15 is a high pressure tubular member having an interior surface 16 and an exterior surface 18 . Wellhead housing 15 secures to a first string of casing 17 , normally 20 inches in diameter, which extends through the conductor pipe 13 to a deeper depth into the well. Normally, first string of casing 17 is cemented in place.
An intermediate casing hanger 25 and intermediate casing 27 are installed in wellhead housing 15 and casing 17 . The intermediate casing hanger 25 lands on a lower shoulder in the interior surface of the wellhead housing 15 below the production casing hanger 19 . The intermediate casing hanger 25 is sealed by an intermediate casing hanger packoff 26 to the interior surface 16 of the wellhead housing 15 . Intermediate casing hanger 25 secures to a string of intermediate casing 27 , typically between 10 and 16 inches in diameter, with larger diameter than the production casing 23 , and with smaller diameter than the first string of casing 17 . Intermediate casing 27 extends between the first string of casing 17 and the production casing 23 to an intermediate depth. Normally, intermediate casing 27 is cemented in place.
A production casing hanger 19 having an interior surface and an exterior surface lands on a shoulder on the intermediate casing hanger 25 . Production casing hanger 19 is sealed by a production casing hanger packoff 21 to the interior surface 16 of the wellhead housing 15 . Production casing hanger 19 secures to a string of production casing 23 , typically between 7 and 16 inches in diameter. Production casing 23 extends through the intermediate string of casing 17 to a final depth of the well. Normally, production casing 23 is cemented in place.
A production casing annulus 29 exists in the space surrounding the production casing 23 . Production casing annulus 29 also surrounds production casing hanger 19 up to production casing hanger packoff 21 . Normally, there would be only nominal, atmospheric pressure in the production casing annulus 29 . Only a lower portion of production casing 23 is exposed to well pressure and this exposure is through perforations (not shown). A packer (not shown) will locate in production casing 23 above these perforations to seal the well pressure within the lower portion of production casing 23 . Pressure other than atmospheric exists in production casing annulus 29 only when a leak occurs.
A communication passage 31 extends laterally through production casing hanger 19 from exterior surface to interior surface. This passage allows fluid communication between the production casing annulus 29 and the interior surface of production casing hanger 19 .
While pumping cement down the casing, cement returns through flowby slots 32 should not enter the bore of casing hanger 19 . When production casing 23 is being installed, fluid communication between the interior surface and the exterior surface is not desired. As depicted in FIG. 2, communication passage 31 may be sealed from fluid communication prior to completion by using a port closure sleeve 33 with upper and lower seals 34 . Seals 34 locate above and below communication passage 31 . Port closure sleeve 33 is threadably connected to production casing hanger 19 . Port closure sleeve 33 has an interior surface and an exterior surface. A slot 39 in the interior surface of port closure sleeve 33 allows a tool (not shown) to unscrew the port closure sleeve 33 from the production casing hanger 19 and remove the port closure sleeve 33 through a tree assembly (not shown in FIG. 2) installed on the wellhead housing 15 , prior to running tubing.
Referring to FIG. 3, a horizontal tree assembly 41 , including a tree 43 and later a tubing hanger 44 , lands on wellhead housing 15 . Tree 43 is lowered with drillpipe. The tree assembly 41 includes a vertical bore 35 with lateral production outlet 36 connected to a valve 37 , lateral annulus outlet 38 from below the tubing hanger and connected to a valve 40 , and workover port 30 from above the tubing hanger 44 , connected to the annulus outlet 38 and connected to a valve 32 . After installing the tree 43 on the wellhead housing 15 and prior to installing the tubing hanger 44 , a retrieval tool (not shown) is lowered through the riser into engagement with port closure sleeve 33 and retrieves port closure sleeve 33 through the bore of tree 43 . A tubing hanger orientation sleeve 53 having an exterior surface lands in a shoulder 55 in tree 43 . The tubing hanger orientation sleeve 53 is also in sealing engagement with the tree 43 . A pin 57 located on the exterior surface of tubing hanger orientation sleeve 53 orients to a slot 56 in tree 43 . The tubing hanger orientation sleeve 53 has an interior helical cam 46 and slot 48 that mates with the tubing hanger pin 50 for aligning the tubing hanger 44 with the tree 43 . Tubing hanger 44 , which is connected to a string of tubing 52 , lands, locks, and seals in tree 43 . As the tubing hanger 44 lands, it rotates to proper orientation by the interaction of the pin 50 on the cam 46 and into the slot 48 .
Tree 43 has a lower interior surface that locates above the wellhead housing 15 and faces downward. A tree communication passage 47 extends upward from lower interior surface 45 . Tree communication passage 47 has a lateral portion 47 A that leads to an outlet (not shown) on the exterior of the tree 51 .
The tubing hanger orientation sleeve 53 has a lower end that sealingly mates in the interior surface or bowl of the production casing hanger 19 . Tubing hanger orientation sleeve 53 seals on the interior surface of the production casing hanger 19 at a point below communication passage 31 . Communication passage 31 is exposed to an annular space surrounding orientation sleeve 53 . Tubing hanger orientation sleeve 53 also seals in an interior surface 59 of tree 43 above the lower interior surface 45 . A fluid communication space 61 is thus created through which production casing annulus 29 can communicate with tree communication passage 47 .
In operation, the tree 43 lands, locks and seals on the wellhead housing 15 . A retrieval tool lowered through the riser and blowout preventer system retrieves the port closure sleeve 33 . The tubing hanger orientation sleeve 53 lands in the tree 43 , is rotated until the pin 57 locates in the slot 56 . In this position, the tubing hanger orientation sleeve 53 seals in the production casing hanger 19 below the communication passage 31 and in the tree 43 , thereby creating a pressure-isolated, fluid communication space 61 between the production casing annulus 29 and the tree communication passage 47 . The tubing hanger 44 , along with a string of tubing, lands in the tree 43 , orients with the tubing hanger orientation sleeve 53 as described above, and locks and seals to the tree 43 . In this position, the tubing hanger 44 provides pressure-isolated communication between the production bore and the production outlet in the tree 43 . Pressure in casing annulus 29 communicates through port 31 , space 61 and tree communication passage 47 .
In the embodiment of FIG. 4, a tree assembly 63 , including tubing hanger spool 65 , a tubing hanger 64 , and a tree 66 , lands on wellhead housing 15 . Tree 66 , unlike the first embodiment, is not a horizontal tree. Tubing hanger 64 lands, locks, seals, and orients in tubing hanger spool 65 rather than in tree 66 . Tree 66 lands on tubing hanger spool 65 after tubing hanger 64 is installed. Tubing hanger spool 65 has a lower interior surface 67 that locates above the wellhead housing 15 and faces downward. A tubing hanger spool communication passage 69 extends upward from lower interior surface 67 . Tubing hanger spool communication passage 69 has a lateral portion 69 A that leads to an outlet on the exterior of the tubing hanger spool 65 .
A spanner sleeve 73 having an exterior surface 75 lands in a shoulder 77 in tubing hanger spool 65 . Spanner sleeve 73 mates in the interior surface 20 of the production casing hanger 19 . Spanner sleeve 73 seals on the interior surface 20 of the production casing hanger 19 at a point below communication passage 31 . Spanner sleeve 73 also seals in an interior surface 79 of tubing hanger spool 65 above the lower interior surface 67 . A fluid communication space 81 is thus created through which production casing annulus 29 can communicate with tubing hanger spool communication passage 69 .
The invention has significant advantages. The communication passages enable pressure from the production casing annulus to be communicated to the exterior of the wellhead housing, without penetrating the wellhead housing and without complicating the tubing hanger with additional ports and seals. The system allows the production casing annulus pressure to be monitored when either a horizontal tree system or a tubing spool and conventional tree system are installed, without use of different production casing hanger and port closure sleeve components or tools. While the invention has been shown in only two of its forms, it should be apparent to those skilled in the art that it is not so limited but is susceptible to various changes without departing from the scope of the invention.
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A subsea wellhead and completion system which provides for monitoring pressure in the annulus of the production casing through communication passages that are pressure-isolated from tubing annulus passages and production fluid passages. The communication passages route production casing annulus fluid pressure from the production casing annulus through the production casing hanger to a communication passage provided between the wellhead housing and an isolation sleeve that spans and seals between the production casing hanger and the tree and then through the tree to an outlet on external diameter of the tree and thence to monitoring equipment located typically at the rig. A removable closure member is located in the production casing hanger to isolate the communication passage during drilling operations. This closure member is removed after drilling operations are concluded and after the tree is installed, but before the isolation sleeve and tubing hanger are landed.
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I. FIELD OF THE INVENTION
[0001] The present invention relates generally to TV-centric home entertainments systems.
II. BACKGROUND OF THE INVENTION
[0002] Home networks including TVs that may communicate with various devices such as disk players, digital video recorders (DVR), personal computers, and the like can be difficult for non-technical users to set up and manage. Indeed, even technical users often encounter frustration in setting up and managing home networks.
[0003] Among the difficulties in managing home networks is that of resource management. For example, it might happen that a movie a user wishes to view on his TV is available on both a DVD player and a DVR, but the user typically has no way of knowing which device would be optimum to use from a bandwidth standpoint. Indeed, bandwidth considerations can change over time, as playing a movie from the DVD player might at one point in time result in the most optimum network bandwidth allocation while at a later point in time the optimum bandwidth allocation might be achieved by playing the same movie from the DVR.
[0004] Moreover, as intimated by the discussion above, it can happen that the network contains more than one storage device, and that duplicate copies if the same piece of content might be stored on more than one device. This might be desirable in some cases and undesirable in others, but regardless, users typically have little or no tools to help them manage home entertainment network storage. With the above critical recognitions in mind, the invention herein is provided.
SUMMARY OF THE INVENTION
[0005] In a home network including at least one TV with TV processor and at least first and second sources of audio/video communicating with the TV over respective first and second paths, a method is provided that includes using bandwidth information about each path and/or using QoS information about each path, outputting an optimum one of the paths.
[0006] In non-limiting implementations the network may also include at least two storage sinks, and the method can include using storage capacity information about each sink to indicate an optimum one of the sinks. The TV can display a map to execute the indicating step, or the TV, in response to user input to play audio/video that is available on both sources, can automatically select the source associated with the optimum path. The user may be permitted to select a path/sink on the map.
[0007] In another aspect, a system has a TV displaying a network map representing a home network, and a user input device manipulable to navigate the map and to select icons on the map representing components in the system for a user-desired task. The map can change the appearance of at least one icon and/or path between icons to provide visible indication of advantageous component and/or path selection for executing the task.
[0008] One component can be a personal computer communicating with non-audio/video peripherals in a computer network. The TV communicates with at least one audio/video component in a TV network, and the computer network and TV network can be physically implemented using at least one common communication path. In this non-limiting embodiment, a common communication protocol can be used between the TV and PC, in which case the TV can be given arbiter rights to manage bandwidth for audio/video data transmissions in the TV network and the PC can be given arbiter rights to manage bandwidth for non-audio/video data transmissions in the computer network.
[0009] In yet another aspect, a TV processor associated with a TV can have code means for comparing first and second bandwidths and/or first and second quality of service (QoS) indications of respective first and second communication paths in a home network. The processor can also have code means for outputting an optimum path based on the means for comparing.
[0010] The details of the present invention, both as to its structure and operation, can best be understood in reference to the accompanying drawings, in which like reference numerals refer to like parts, and in which:
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a block diagram of a non-limiting TV-centric system in accordance with the invention; and
[0012] FIGS. 2-4 are screen shots showing non-limiting network maps that can be displayed on the TV.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0013] Referring initially to FIG. 1 , a non-limiting home entertainment system is shown, generally designated 10 , which includes a TV housing 12 holding TV components including a TV display 14 , a TV tuner 16 , and a TV processor 18 . The TV tuner 16 may receive input from a set-top box (STB) 20 that, as indicated in FIG. 1 , can be part of the housing 12 or alternatively can be in a housing separate from the housing 12 . In any case, the STB 20 receives TV signals from one or more sources 22 such as but not limited to satellite receivers, cable system head ends, broadcast receiver antennae, etc. Depending on the nature of the signal, it may be sent directly to the display 14 from the tuner 16 or sent first through the processor 18 for subsequent display. It is to be understood that the tuner 16 may be in the STB 20 to output signals to the TV in analog format (e.g., CVBS, Y/C, or RGB) and/or digital format (e.g., DVI, HDMI, IEEE 1394 (referred to as iLink), USB, or some other appropriate format.)
[0014] The non-limiting embodiment shown in FIG. 1 illustrates that the present TV can be connected to a plurality of external systems and networks, it being understood that in some implementations not all the components shown in FIG. 1 need be used. In essence FIG. 1 shows a comprehensive TV-centric system for completeness.
[0015] In one embodiment, the TV processor 18 may communicate with a digital living network association (DLNA) system 24 . Also connected to the DLNA system 24 can be various components including but not limited to a disk player such as a DVD player 26 or Blu-Ray disk player and a digital video recorder (DVR, also known as a personal video recorder (PVR)) 28 . Information including multimedia streams such as TV programs and movies can be exchanged between the TV processor 18 and the DVD player 26 and PVR 28 in accordance with DLNA principles known in the art.
[0016] Plural LAN interfaces may be included in the TV to provide both wired and wireless interfaces. These may take the form of an Ethernet across the various physical interfaces such as but not limited to IEEE 802.3 wired, IEEE 802.11x wireless, or virtual Ethernet across coaxial cable or across the home's AC power line connection.
[0017] Accordingly, a wired local area network (LAN) interface 30 may be provided in the TV housing 12 and connected to the TV processor 18 , so that the TV processor 18 can communicate with components on a wire LAN, implemented in some embodiments as an Ethernet. These components may include a personal computer 32 or other computer, and the computer 32 can communicate with computer network peripheral equipment such as but not limited to a printer 34 , a scanner 36 , and a security camera 38 . All or parts of the computer network may overlap with the various networks with which the TV processor 18 communicates as discussed more fully below.
[0018] In addition to Ethernet links, the LAN may include one or more wireless links 40 , so that the PC 32 (and, hence, the TV processor 18 ) may communicate with wireless components such as a vehicle-mounted global position satellite (GPS) receiver 42 . Without limitation, the wireless link 40 , like other wireless links herein, may be, e.g., an 802.11 link, a Wi-Fi link, a Bluetooth link, an IR link, an ultrasonic link, etc.
[0019] In some implementations, a pre-existing LAN might exist in the form of twisted pair wiring, coaxial wiring, power line, etc. in a house, and it might be desired to use the pre-existing LAN for the TV components to establish a shared network. In such a case, the physical media is shared between the PC 32 and TV processor 18 with associated components. In one embodiment, the TV components can use a first protocol such as a proprietary protocol while the PC 32 and associated peripherals can use a different, second protocol, so that communication interference is avoided. Alternatively, if a common protocol is used, undesirable devices from the TV standpoint (such as, e.g., the printer 34 and scanner 36 ) can be removed from the TV network so that, for example, they do not appear on the below-described TV network maps.
[0020] When the same protocol is used between the TV processor 18 and the PC 32 , the TV processor 18 can be given arbiter rights to manage bandwidth for audio/video data transmissions in the network, and the PC 32 can be given arbiter rights to manage bandwidth for non-audio/video data transmissions. Also, the TV processor 18 may “see” the PC 32 in the TV network but this does not mean that the PC 32 necessarily recognizes the TV components to be part of its network. A router hub may be used in the case of a IEEE 802.3 LAN to accommodate various network devices and enable both wired and wireless devices to communicate at a common point, i.e., a wireless access point communicates wirelessly to various devices and via 10/100BaeT bridged through the router hub to the wired devices. This hub in effect is represented inside the TV housing 12 along the bottom.
[0021] Apart from the wireless link 40 of the LAN with which the TV processor 18 may communicate, a wireless communication interface 44 may be in the TV housing 12 and may communicate with the TV processor 18 as shown. The wireless communication interface may wirelessly communicate with various components such as but not limited to a video game console 46 , such as a Sony Playstation®, and another TV 48 that might be located in, e.g., another room.
[0022] The processor 18 may also communicate with a computer modem 50 in the TV housing 12 as shown. The modem 50 may be connected to the Internet 52 , so that the TV processor 18 can communicate with a web-based system server 54 and a web-based data vault 56 .
[0023] In addition to the wireless communication interface 44 and the modem 50 , the TV processor 18 may communicate with a radiofrequency identifier (RFID) interface 60 in the housing 12 or attached thereto using, e.g., a uniform serial bus (USB) cable, to facilitate communication in accordance with RFID principles known in the art between the TV processor 18 and an RFID-enabled network appliance 62 having an RFID device 63 mounted on it or connected to it. Furthermore, the TV processor 18 can, through an infrared interface 64 , receive user commands from a remote control device 66 that transmits IR signals, it being understood that the remote control device 66 may alternately use RF, in which case the interface 64 would be an RF interface.
[0024] FIG. 1 also shows that the TV can have a data storage 69 . The storage 69 may be flash or ROM or RAM in the TV and/or it may be a removable memory device such as a Sony Memory Stick®.
[0025] Among the recognitions made herein, it may happen that in some implementations, the TV shown above may not have a hard disk drive (HDD) and/or the PVR 28 may not be available or the correct digital rights management information may be unavailable for recording a program to disk. Accordingly, as shown in FIG. 2 the TV processor 18 may cause to be presented on the TV display 14 a topography map, generally designated 68 , that is essentially a user interface that a user can operate on by means of the remote control device 66 to map a HDD in the PC 32 to the TV to thereby allow the user to load content received by the TV onto the PC HDD for later reliable streaming. The PC 32 may also transcode multimedia streams from a codec that might be incompatible with the TV to another, compatible codec. Note that the map 68 shown in FIG. 2 need not show all of the components illustrated in FIG. 1 , but can illustrate some or all of the components in the system as desired for simplification. Content stored on the HDD of the PC 32 may later be played back on the TV display 14 . Also, content from non-TV sources, e.g., from the DVD player 26 , may be sent to the PC 32 HDD for storage.
[0026] To operate the UI that is represented by the map 68 , a user can manipulate buttons on the remote control device 66 to navigate around the map, clicking on a component with a button designating the component as a “source” and then moving the cursor over the desired “sink” component (in the case shown, the PC) and clicking on a “sink” button to indicate that recording from the source to the sink is to be undertaken. This is but one non-limiting example of how the map 68 can be used to send content from the TV and/or DVD player 26 to the home PC 32 .
[0027] The map 68 can be created by the TV processor 18 automatically, upon initial connection and perhaps also on every subsequent energization, “discovering” networked devices in accordance with network discovery principles known in the art. Or, a user may be permitted to manually input data to construct the map 68 using the remote control device 66 .
[0028] FIG. 3 shows a screen shot that can be presented on the display 14 to provide a network map 70 that can be used as a user interface for determining an optimum path for a desired function. With more specificity, using the map 70 , a user can select a source and sink device for, e.g., playing a multimedia stream and then be presented with information pertaining to a “best” arrangement that can depend on bandwidth considerations, quality of service (QoS) considerations, and device capabilities.
[0029] To illustrate, assume the following hypothetical. A user can move the cursor over each icon shown in FIG. 3 to cause a drop-down menu to appear, showing the capabilities of that device. Assume that it is the user's intentions to find and play “movie A”, and that when the cursor is over the DVD icon, the PVR icon, and the TV internet server icon, a menu appears indicating that “movie A” is stored on the associated component. When the cursor is over the display and TV icons, assume that a menu appears indicating the capabilities of the display, e.g., “HD” or “SD”.
[0030] Should the user input “movie A”, the display in FIG. 4 can appear, in which, depending on determinations made by the TV processor 18 , some icons representing components that are completely unsuitable for sourcing “movie A” given its format (such as the CD icon) or playing “movie A” given its format (such as the “other TV” icon) are removed from the map 70 entirely while other icons representing components that can source or play, albeit suboptimally, “movie A” (such as the “game console” icon and “display 1 ” icon) are lowlighted. In lieu of or in addition to icon lowlighting or removal, path lines between icons can be lowlighted or removed.
[0031] Thus, only icons (and/or path lines) representing components that can adequately source or play the selection remain on, and a “best” path may be highlighted, e.g., all three source icons (DVD, PVR, and TV server) shown in FIG. 4 remain on, only a single sink icon (“display 2 ”) remains on, and if bandwidth considerations or quality of service considerations or storage space considerations or other operational considerations indicate that streaming “movie A” from the DVD to the display 2 is the optimum path, that path can be highlighted. In this way, the user knows what the optimal source/sink arrangement is for the desired stream.
[0032] In determining a best path based on bandwidth considerations, the following non-limiting heuristics can be used. The bandwidth required for streaming a movie in the format selected (e.g., HD) is compared to the measured or estimated bandwidths that are available between the TV and each potential source as measured or estimated during initial power-on or periodically by the TV and/or source. Sources communicating with the TV over paths with insufficient bandwidth are eliminated. If two or more sources communicate with the TV over paths that have sufficient bandwidth, the “best” source can be determined to be the one that can source the movie with the least impact on the remainder of the network. For example, if a DVD player shares part of the same physical network as a PC and the PC is turned on, indicating that streaming from the DVD player could reduce PC network bandwidth, then an alternate source such as the PVR (assuming it has sufficient bandwidth) may be selected. All of these determinations may be made by, e.g., the TV processor transparently to the user.
[0033] Likewise, QoS can be used to determine the best path. If the difference in QoS between two paths exceeds a threshold, for instance, the path having the best QoS can be selected; otherwise (i.e., if QoS is about equal), the path with the greatest bandwidth is indicated as being optimal. Or, QoS may be a subsidiary consideration to use, if, for example, bandwidth is primary and two paths are found to have approximately equal bandwidths. In this case, the path having the best QoS can be indicated as being “best”. Some combination of bandwidth and QoS might always be used by weighting both bandwidth and QoS from each available path and combining them, and then indicating as the optimal path the one with the “best” combination.
[0034] Similar heuristics can be applied in reverse, i.e., for storing content in the network, by determining remaining storage capacity in the various storage devices, whether a particular device stores data from more than one source or is dedicated to a single source, etc. As an example, if a TV show is to be recorded and both the HDD of the PC and the PVR are available, if both devices have approximately the same remaining capacity as reported to, e.g., the TV, storage on the PVR might be indicated as being optimal in that the PVR usually is dedicated to the TV while the PC HDD must also store data from the PC and other components. On the other hand, if the PVR is almost full and the PC HDD almost entirely free, storage on the PC HDD might be indicated as being optimal. This is but one non-limiting example of how a network processor such as a TV processor might use storage capacity information pulled from or pushed by network devices to indicate optimum storage sinks and thus aid the user in network management.
[0035] Thus, the TV processor 18 , in conjunction with the above-described network maps, allows users to select optimum sources and sinks in the system 10 to display particular multimedia streams, and to prioritize and schedule more than one event. For instance, a user can undertake the above-described hypothetical selection of “movie A”, store it to memory in the TV for playback at a scheduled future time, and then schedule another event (e.g., record “TV program B”) for an overlapping period. The TV processor 18 in such as case could, in some implementations, recalculate the “movie A” arrangement in light of the desire to record “TV program B” to ensure that bandwidth, storage space, QoS, etc. remain optimized.
[0036] In undertaking the above, the TV processor 18 can discover the other components shown in FIG. 1 to generate one or more of the non-limiting network maps described above. The TV may “pull” storage capacity and bandwidth information from each component, or the components might automatically and periodically “push” this information to the TV.
[0037] In any case, when the TV is first taken out of the box by the user and turned on, the TV processor 18 can in some implementations automatically search for networks and other connections, e.g., Ethernets, DLNA networks, etc., obtain bandwidth/storage capacity/QoS/other network management information, and then inform the user as to what capabilities exist, showing, if desired, the map on the display 14 . Appropriate configuration of the TV and network is then automatically executed, relieving the user of the sometimes confusing chore of “setting up” the home network.
[0038] Instead of indicating to the user the “best” path it is to be understood that the TV processor 18 may simply automatically select a source of audio/video having the optimal bandwidth/QoS and/or select the best storage sink having the optimal storage capacity.
[0039] While the particular TV-CENTRIC SYSTEM is herein shown and described in detail, it is to be understood that the subject matter which is encompassed by the present invention is limited only by the claims.
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Home network resources and communication paths are managed using network path bandwidths, network storage capacities, and quality of service.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates to coffee brewing machines. More particularly, although not exclusively, the invention relates to a domestic appliance capable of producing a hot liquid coffee beverage having a layer of fine bubbles or coffee crème at its surface.
[0002] Many coffee drinkers enjoy coffee having a layer of coffee crème at the liquid surface. This is a layer of fine bubbled froth produced by the coffee extract in hot water. This is to be distinguished from frothed milk as might be applied to café latte or cappuccino for example. Coffee beverages purchased from commercial establishments usually have a crème layer and this is perceived as an indication of a high quality coffee.
[0003] It is very difficult to achieve a crème layer when brewing one's own coffee at home or in the office without use of expensive commercial equipment.
OBJECTS OF THE INVENTION
[0004] It is an object of the present invention to overcome or substantially ameliorate the above disadvantage and/or more generally to provide an improved coffee machine with a crème production facility.
DISCLOSURE OF THE INVENTION
[0005] There is disclosed herein a coffee-making machine, comprising:
[0006] a nozzle from which an airborne stream of liquid containing coffee extract is ejected under pressure,
[0007] a funnel downstream of the nozzle for receiving the ejected coffee extract and draining it substantially without retention, and
[0008] a frothing member positioned in or upstream of the funnel and against which the airborne stream of liquid from the nozzle impinges directly and by which air is entrained in the liquid.
[0009] Preferably, the coffee-making machine further comprises a spout that extends from the funnel and through which the liquid is dispensed.
[0010] Preferably, the coffee-making machine further comprises a chamber upstream of the nozzle and into which a ground coffee-containing pouch is received.
[0011] Preferably, the frothing member comprises a plate having an aperture therethrough.
[0012] Alternatively, the frothing member comprises a plate having a plurality of apertures therethrough.
[0013] Preferably, the frothing member in attached to or formed integrally with the funnel.
[0014] Preferably, the frothing member is detachable from the funnel.
[0015] Preferably, the plate extends normally to the stream of liquid ejected by the nozzle.
[0016] There is further disclosed herein a coffee-making machine, comprising:
[0017] a nozzle through which a stream of liquid containing coffee extract is ejected under pressure, the nozzle having an air-entry aperture through which air enters the nozzle to mix with the stream of liquid as it passes through the nozzle.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Preferred forms of the present invention will now be described by way of example with reference to the accompanying drawings, wherein:
[0019] FIG. 1 which is a schematic cross-sectional elevation of the key components of a coffee-making machine that are relevant for the production of a coffee crème layer in a cup of coffee produced by the machine, and
[0020] FIG. 2 is a schematic cross-sectional elevation of an alternative apparatus for the production of a coffee crème layer.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0021] In FIG. 1 of the accompanying drawing there is depicted schematically a coffee-making machine 10 and a cup 11 to which the coffee beverage is to be dispensed. Many components of the machine are not depicted in the drawing because they are known in the art. Some of these features include a liquid reservoir, a heater for heating water from the reservoir and an electric pump for pumping the water under pressure to a delivery line 12 .
[0022] The delivery line 12 delivers hot pressurised water to a sealed chamber 13 in which a paper-encased ground coffee pouch 14 is received. A closure mechanism (not shown) seals the chamber 13 .
[0023] In the bottom of the chamber there is provided a small nozzle 15 from which coffee extract-containing heated water is ejected downwardly in a vertical stream. This stream is directed into a space containing air, hence the stream can be said to be “airborne”. The nozzle is small in diameter (typically about 0.8 mm) and serves two fundamental functions. The first function is to produce the high-velocity liquid jet and the second function is to regulate the flow rate of water through the chamber 13 . This obviates the requirement for a mechanical or optical flow-metering device in or upstream of the delivery line 12 to deactivate the pump when the cup 11 is anticipated to be full. In the present embodiment, a simple digital timer deactivates the pump when the cup is near-full.
[0024] Situated beneath the chamber 13 is a funnel 16 having an outlet spout 17 via which the coffee beverage is dispensed to the cup 11 .
[0025] Located within the funnel 16 and surrounded by air is a frothing member 18 that extends upwardly from the floor 21 of the funnel 16 . In the depicted embodiment, the frothing member comprises a flat horizontal plate 19 having a plurality of vertical apertures 20 therethrough. The frothing member might be moulded integrally with the funnel 16 , or manufactured as a separate attachment. Manufacturing the frothing member as a separate attachment simplifies moulding of the combined funnel and frothing member. Also, if the frothing member is detachable from the funnel 16 it can be easily removed for cleaning, or removed by users who do not wish to make coffee with a crème layer. To facilitate removal, the frothing member might slot into the funnel 16 , or be attached thereto by screws or other fastening devices.
[0026] In use, heated water is pumped via the delivery line 12 through the chamber 13 whereupon coffee extract from the ground coffee beans within the pouch 14 forms a liquid jet upon passing from the nozzle 15 . This liquid jet passes through the airspace and impinges forcefully and downwardly upon the plate 19 of the frothing member 18 . Some of the liquid jet will be forced through at least one of the vertical apertures 20 and some of the liquid jet will deflect from the upper surface of the plate 19 and fall into the funnel 16 . The frothing member will never be submerged as the funnel is designed to pass liquid immediately to the cup without retaining it. The upper opening of the funnel is sealed and therefore any splashes of liquid will not escape through the top of the funnel to the surrounding bench space. The liquid jet undergoes significant turbulence and sheer forces as it encounters the frothing member. This results in the formation of fine bubbles which are then carried away with the flow of liquid across the floor 21 of the funnel 16 and then through the spout 17 to the cup 11 to thereby create a coffee crème layer upon the coffee in the cup 11 .
[0027] The frothing member would typically be made of hard plastics material, stainless steel or brass for example.
[0028] It could be formed as a moulding, casting or pressing, or might be in the form of a single- or multiple-layered mesh.
[0029] In FIG. 2 there is depicted an alternative embodiment which does not rely upon a frothing member against which the airborne stream of liquid from the nozzle impinges. Instead, the nozzle 15 is formed as a spray head having a small aperture. When the coffee extract exits the nozzle 15 it forms a fine spray 21 which then forms a foam layer upon the floor 21 of the funnel and then flows under gravity through the spout 17 for dispensation to form a crème.
[0030] 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, rather than being a fixed structure, the frothing member might be made movable, such as for example by being rotatably mounted upon an axle, or resiliently mounted upon a spring. Furthermore, instead of being attached to the funnel, the frothing member might depend from the bottom surface of the pressure chamber. It might even be formed integrally with the nozzle.
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A coffee-making machine includes: a nozzle from which an airborne stream of liquid containing coffee extract is ejected under pressure, a funnel downstream of the nozzle for receiving the ejected coffee extract and draining it substantially without retention, and a frothing member positioned in or upstream of the funnel and against which the airborne stream of liquid from the nozzle impinges directly and by which air is entrained in the liquid.
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BACKGROUND OF THE INVENTION
This invention relates generally to solar power systems. More particularly, the present invention relates to solar power systems having a tracking system for accurately pointing a solar collector at the sun throughout the day.
Early solar power systems included solar tracking systems employing two independent drives to tilt the solar collector about two axes. The first, an elevation axis, allowed the collector to be tilted within an angular range of about ninety degrees between “looking at the horizon” and “looking straight up”. The second, an azimuth axis, is required to allow the collector to track from east to west. The required range of angular rotation depends on the earth's latitude at which the solar collector is installed. For example, in the tropics the angular rotation needs more than 360 degrees.
These early solar power tracking systems generally used electric drives having high ratio gear reducers to turn the collector in the direction of the sun. Error in the gear reducers or linkage between the motor and collector, such as backlash and non-linearly, detracted from the accuracy. When high accuracy was required, the gear reducers were very expensive.
These conventional solar power systems occasionally suffered damage from high winds. Thus, it is known to place the solar collector in a wind stow position and avoid damage when winds exceed the design specifications. “Wind stow” is an attitude of the collector that presents the smallest “sail” area to the wind. Generally, a wind sensor was used trigger a command for the elevation actuator to point the collector straight up. The electric elevation actuators and high ratio speed reducers utilized by these systems were very slow to put the collector into wind stow, sometimes taking as long as forty-five minutes. If movement to the wind stow position was initiated at a low threshold value of the wind, to account for the long lead time, the efficiency of the solar power station was adversely affected. If efficiency was optimized by increasing the threshold value of wind required to initiate movement to the wind stow position, a rapidly increasing wind would cause damage to the solar collector.
U.S. Pat. No. 6,123,067 proposed a solar power system that had an exoskeleton structure secured to the rear surface of the solar collection device and that is pivotally secured about a horizontal axis to the front end of an azimuth platform assembly. A hydraulic elevation actuator is pivotally mounted in the azimuth platform assembly about a horizontal axis and the front end of its piston rod is pivotally connected to the rear surface of the solar collection device, allowing the solar collection device to be pivoted approximately 90 degrees between a vertical operating position and a horizontal storage position. Primary and a secondary azimuth hydraulic actuator are used to rotate the collection device for tracking the sun. It was believed that such a tracking system would require less time to move the solar collector to the wind stow position. However, the solar collector of such a solar power system can not be scaled up significantly.
SUMMARY OF THE INVENTION
Briefly stated, the invention in a preferred form is a solar power station which comprises a solar panel assembly having a substantially planar solar panel. Multiple towers are individually extendable from a bottom position to an extended position. Each of the towers has an upper end and a main bearing structure pivotally mounting the solar panel assembly to the tower upper end. Selectively moving one or more of the towers rotates the solar panel about one or both of the axes of the solar panel, such that the solar panel is maintained at an optimal orientation for collecting solar power.
Preferably, the solar power station includes first, second and third towers, the first tower being longitudinally spaced from the second tower and the third tower being laterally spaced from the first and second towers.
The main bearing structure of the towers includes a main slide bearing box mounted to the tower upper end. A main support shaft extends longitudinally through the main slide bearing box, and is longitudinally and rotationally movable relative to the main slide bearing box. For the first and second towers, first and second support boxes are mounted on the main support shaft first and second end portions, respectively, and to the solar panel assembly. For the third tower, first and second secondary slide bearing boxes are longitudinally mounted on the main support shaft first and second end portions. First and second secondary support shafts extend laterally through the first and secondary slide bearing boxes, respectively. First and second support boxes are mounted on the first and second end portions, respectively, of each of the first and second secondary support shafts, and to the solar panel assembly.
The main slide bearing box includes a lower mounting assembly fixedly mounted to the tower upper end and an upper bearing assembly having a longitudinal opening for receiving the main support shaft. The upper bearing assembly is pivotally mounted to the lower mounting assembly about the lateral axis.
The solar power station includes a controller for actuating movement of the towers between the bottom and extended positions. The solar power station may include an earthquake senor, the controller withdrawing all of the towers to the bottom position when the detected ground vibration rises above a predetermined level. The solar power station may include a wind senor, the controller withdrawing all of the towers to the bottom position when the detected wind force rises above a predetermined level.
Each of the towers comprises a plurality of vertically stacked floors, including a ground floor and at least one upper floor. Each of the floors includes an arrangement of robots (R 1 , R 2 , R 3 , R 4 ) and a connecting framework of push and pull steel frames (F 1 , F 2 ). The robots of each floor are connected to each vertically adjacent floor. The robots (R 1 , R 2 , R 3 , R 4 ) and steel frames (F 1 , F 2 ) are organized in groups (HR 1 , HR 2 , HR 3 , VR 1 , VR 2 , VR 3 , VR 4 ), the associated robots and steel frames of each group being connected together. The R 1 robots include hydraulic jacks for moving the towers between the bottom and extended positions. The hydraulic jacks of the R 1 robots of the ground floor include springs.
The ground floor further includes a base member, an upper plate, multiple spring devices disposed between the base member and the upper plate, and multiple poles. Each of the poles extends vertically, from a foot mounted to the base member, through an opening in the upper plate. During a strong wind or an earthquake, the upper plate moves vertically upward or downward along the pole whereby the spring devices absorb shock energy generated by lateral forces exerted on the tower by the wind or the earthquake.
The ground floor further includes an outer, space frame ring forming a framework mounted to the base member and having multiple of brackets disposed above the upper plate. Each of the brackets has an opening for receiving a one of the poles, whereby the space frame ring constrains horizontal deflection of the poles.
Each upperfloor includes an upper plate, with openings for receiving the poles. The robots of each upper floor are connected to the upper plate of the respective floor and the upper plate of the floor vertically below the respective floor.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention may be better understood and its numerous objects and advantages will become apparent to those skilled in the art by reference to the accompanying drawings in which:
FIG. 1 is a rear perspective view of a solar power station system in accordance with the invention, showing the system positioned for capturing sunlight at sunrise;
FIG. 2 is a rear perspective view of the solar power station system of FIG. 1 , showing the system positioned for capturing sunlight at noon;
FIG. 3 is a rear perspective view of the solar power station system of FIG. 1 , showing the system positioned for capturing sunlight at sundown;
FIG. 4 is a front perspective view of the solar power station system of FIG. 1 , showing the system being positioned in a first direction of rotation;
FIG. 5 is a side perspective view of the solar power station system of FIG. 4 ;
FIG. 6 is an enlarged perspective view of the support box, the support shaft, and the slide bearing box of the first or second towers of FIG. 1 ;
FIG. 7 is an enlarged bottom view of the support box and the support shaft of FIG. 6 ;
FIG. 8 is an enlarged perspective view of the support box and the support shaft of FIG. 6 ;
FIG. 9 is a cross-section view taken along line IX-IX of FIG. 7 ;
FIG. 10 is a cross-section view taken along line X-X of FIG. 7 ;
FIG. 11 is an exploded view of the piston shock absorber of FIG. 10 ;
FIG. 12 is an enlarged front view of the slide bearing box of FIG. 6 ;
FIG. 13 is a cross-section view taken along line XIII-XIII of FIG. 12 ;
FIG. 14 is an enlarged cross-section view of the turnable compression bearing of FIG. 13 ;
FIG. 15 is an enlarged cross-section view taken along line XV-XV of FIG. 13 ;
FIG. 16 is an enlarged perspective view of the main slide bearing box, the main support shaft, the secondary slide bearing boxes, the secondary support shafts, and the support boxes of the third tower of FIG. 1 ;
FIG. 17 is an enlarged bottom view of the support box of FIG. 16 ;
FIG. 18 is a cross-section view taken along line XVIII-XVIII of FIG. 17 ;
FIG. 19 is a cross-section view taken along line XIX-XIX of FIG. 17 ;
FIG. 20 is an enlarged front view of one of the secondary slide bearing boxes of FIG. 16 ;
FIG. 21 is a side view of the secondary slide bearing boxes of FIG. 20 ;
FIG. 22 is an enlarged side view of the main slide bearing box of FIG. 16 ;
FIG. 23 is a front view of the main slide bearing box of FIG. 22 ;
FIG. 24 is a top view of the solar power station of FIG. 1 , with the solar panel assembly removed;
FIG. 25 is a top view of the solar power station of FIG. 2 , with the solar panel assembly removed;
FIG. 26 is a top view of the solar power station of FIG. 3 , with the solar panel assembly removed;
FIGS. 27 a , 27 b and 27 c are simplified side views, partly in cross-section of the main bearing structure of the first or second tower, with the main bearing structure unexposed to an external horizontal force ( FIG. 27 a ), with the main bearing structure exposed to an external horizontal force from the right ( FIG. 27 b ), and with the main bearing structure exposed to an external horizontal force from the left ( FIG. 27 c );
FIG. 28 is a simplified perspective view of the robots of a typical tower floor;
FIG. 29 is an enlarged view of the HR 1 and VR 1 groups of FIG. 28 ;
FIG. 30 is an enlarged view of the HR 3 group of FIG. 28 ;
FIG. 31 is an enlarged view of the VR 3 group of FIG. 28 ;
FIG. 32 is an enlarged view of the HR 2 group of FIG. 28 ;
FIG. 33 is an enlarged view of the VR 2 group of FIG. 28 ;
FIGS. 34 a - 34 d are enlarged views of one of the intersections of group HR 2 and group VR 2 of one of the upper floors of FIG. 28 , showing the HR 2 and VR 2 groups withdrawn ( FIGS. 34 a and 34 c ) and extended ( FIGS. 34 b and 34 d );
FIGS. 35 a to 35 c are enlarged views of a robot R 1 , showing the robot R 1 in the extended position ( FIG. 35 a ), showing the robot R 1 in the extended position, with one of the horizontal roller frames and corresponding pair of jacks removed ( FIG. 35 b ), showing the robot R 1 in the retracted position ( FIG. 35 c ), and showing the robot R 1 in the retracted position, with one of the horizontal roller frames and corresponding pair of jacks removed ( FIG. 35 d );
FIGS. 36 a to 36 c are enlarged views of a robot R 4 , showing the robot R 4 in the extended position ( FIG. 36 a ), showing the robot R 4 in the extended position, with one of the horizontal roller frames and corresponding pair of jacks removed ( FIG. 36 b ), showing the robot R 4 in the retracted position ( FIG. 36 c ), and showing the robot R 4 in the retracted position, with one of the horizontal roller frames and corresponding pair of jacks removed ( FIG. 36 d );
FIGS. 37 a to 37 c are enlarged views of a robot R 3 , showing the robot R 3 in the extended position ( FIG. 37 a ), showing the robot R 3 in the extended position, with one of the horizontal roller frames and corresponding pair of jacks removed ( FIG. 37 b ), showing the robot R 3 in the retracted position ( FIG. 37 c ), and showing the robot R 3 in the retracted position, with one of the horizontal roller frames and corresponding pair of jacks removed ( FIG. 37 d );
FIGS. 38 a to 38 c are enlarged views of a robot R 5 , showing the robot R 5 in the extended position ( FIG. 38 a ), showing the robot R 5 in the extended position, with one of the horizontal roller frames and corresponding pair of jacks removed ( FIG. 38 b ), showing the robot R 5 in the retracted position ( FIG. 38 c ), and showing the robot R 5 in the retracted position, with one of the horizontal roller frames and corresponding pair of jacks removed ( FIG. 38 d );
FIG. 39 is an exploded view of a Robot R 1 /Robot R 5 ;
FIG. 40 is an enlarged exploded view of the lock set of the Robot R 1 /Robot R 5 of FIG. 39 ;
FIG. 41 is an enlarged exploded view of the cable reel of the Robot R 1 /Robot R 5 of FIG. 39 ;
FIG. 42 is an enlarged view of the cable lock of FIG. 41 ;
FIG. 43 is an enlarged view of the cable fastener of FIG. 39 ;
FIG. 44 is an exploded view of a Robot R 2 ;
FIG. 45 is an enlarged perspective view of a space frame ring of one of the towers;
FIG. 46 is an exploded perspective view of the space frame ring of FIG. 45 ;
FIG. 47 is a sectional view of the space frame ring of FIG. 45 ;
FIG. 48 is an exploded view of the first two floors of one of the towers;
FIG. 49 is a perspective view of one of the towers;
FIG. 50 is an enlarged view of the VR 4 group of FIG. 28 ;
FIGS. 51 a and 51 b are enlarged views of one of the intersections of group HR 2 and group VR 2 of the ground floor of FIG. 28 , showing the HR 2 and VR 2 groups withdrawn ( FIG. 51 a ) and extended ( FIG. 51 b );
FIGS. 52 a to 52 f are enlarged views of a robot R 2 , showing the robot R 2 in the extended position ( FIG. 52 a ), showing the robot R 2 in the extended position, with one of the horizontal roller frames and one upper clipper and one lower clipper of the second pair of clipper assemblies removed ( FIG. 52 b ), showing the robot R 2 in the retracted position ( FIG. 52 c ), showing the robot R 2 in the retracted position, with one of the horizontal roller frames and one upper clipper and one lower clipper of the second pair of clipper assemblies removed ( FIG. 52 d ), showing the robot R 2 in the retracted position, with the upper transverse frame removed ( FIG. 52 e ), and showing the robot R 2 in the extended position, with the upper transverse frame removed ( FIG. 52 f ); and
FIG. 53 is a functional block diagram of the solar power station control system.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference to the drawings wherein like numerals represent like parts throughout the several figures, a solar power station in accordance with the present invention is generally designated by the numeral 10 . The solar power station 10 includes three, substantially identical, dynamic steel truss towers 12 , 14 , 16 supporting a solar panel assembly 18 . Supports 20 20 at the ground floor stabilize and support each of the towers 12 , 14 , 16 . It should be appreciated that the solar panel assembly 18 is positioned to optimize collection of sunlight and that the operating description provided below is for illustration purposes only. The operation of the towers 12 , 14 , 16 for orienting the solar panel assembly 18 depends on the topography, latitude and longitude of the installation site.
The solar power station 10 shown in FIGS. 1-3 is installed such that the planar solar panel 19 of the solar panel assembly 18 of FIG. 1 is positioned to receive sun light at sunrise, the solar panel assembly 18 of FIG. 2 is positioned to receive sun light at noon, and the solar panel assembly 18 of FIG. 3 is positioned to receive sun light at sundown. To optimize collection of the solar power, the solar panel assembly 18 is positioned perpendicular (or as close as possible) to the direction of the sunlight. To properly position the solar panel assembly 18 at dawn, the first and third towers 12 , 16 are at a bottom position 22 and the second tower 14 is at a fully extended position 24 . As the sun rises to the noontime position, the first and third towers 12 , 16 are extended from the bottom position 22 . The first tower 12 is extended at a greater rate than the third tower 16 , causing the solar panel assembly 18 to rotate about the longitudinal and lateral axes RA 1 and RA 2 . When the sun is at the noontime position, the first tower 12 has been extended to the fully extended position 24 , the third tower 16 has been extended to an intermediate position 26 (between the bottom position 22 and the fully extended position 24 ), and the second tower 14 has been held fixed in the fully extended position 24 . As the sun falls to sundown, the second and third towers 14 , 16 are withdrawn from the fully extended position 24 and the intermediate position 26 , respectively. The second tower 14 is withdrawn at a greater rate than the third tower 16 , causing the solar panel assembly 18 to further rotate about axis RA 1 and RA 2 . At sundown, the second and third towers 14 , 16 have been withdrawn to the bottom position 22 and the first tower 12 has been held fixed in the fully extended position 24 .
FIGS. 4 and 5 illustrate operation of the towers 12 , 14 , 16 to orient the solar panel assembly 18 substantially opposite to the solar panel assembly 18 shown in FIGS. 1-3 for a site location where the light path to the solar power station 10 is opposite to that shown in FIGS. 1-3 . In FIGS. 4 and 5 , the second tower 14 is positioned at the fully extended position 24 , the first tower 12 is positioned at a first intermediate position 26 (proximate to the bottom position), and the third tower 16 is positioned at a second intermediate position 26 ′ (proximate to the fully extended position). FIGS. 1-5 also illustrate the range of motion that may be required to optimize exposure of the solar panel assembly 18 of a solar power station 10 installed on a moveable object, for example a ship.
The main bearing structures 28 , 28 ′ of the first and second towers 12 , 14 are best illustrated by referring FIGS. 6-15 . Each of the bearing structures 28 , 28 ′ includes a slide bearing box 30 , a support shaft 32 extending through the slide bearing box 30 , and first and second support boxes 34 , 36 mounted at either end of the support shaft 32 . The support shaft 32 is a solid steel shaft. The first and second end portions 38 , 40 of the support shaft 32 are pinned within receptacles 42 of the first and second support boxes 34 , 36 by steel bars 44 . A steel plate 46 is removably mounted in each support box by bolts and nuts 48 to further limit axial movement of the support shaft 32 within the receptacle 42 . A steel frame 50 is fixedly mounted to a base plate 52 , preferably by welds.
The second support box 36 has a shock absorber 54 disposed within an inner chamber 56 ( FIGS. 10 and 11 ). The shock absorber 54 includes a compression bracket 58 at the front of the shock absorber structure. The compression bracket 58 may include a circular, turnable, steel plate 60 sandwiched between two layers of compression bearing 62 . A recessed bolt and nut 64 mounts a plastic compression cushion 66 to the steel plate 60 . Four recessed channels 68 are equidistantly disposed around the periphery of the compression bracket 58 . A piston ring 70 welded to the end of compression bracket 58 has four recessed channels corresponding to the compression bracket channels 68 . The piston ring 70 includes an axial cylinder 72 through which the support shaft 32 passes. The piston ring 70 and compression bracket 58 are reciprocable within a cylinder block 74 . The inner surface of the cylinder block 74 has at least one, axially extending rib 76 that is received within one of the compression bracket channels 68 and piston ring channels to prevent the piston ring 70 and compression bracket 58 from rotating within the cylinder block 74 . Four shock absorbers 78 are radially spaced within the cylinder block 74 . One end of each shock absorber 78 is mounted to a strut 80 , extending from the end face of compression bracket 58 , by a pin 82 and the other end of each shock absorber 78 is mounted to a strut 84 , extending from the support box base plate 86 , by a pin 82 . Each shock absorber 78 includes a heavy duty spring 88 .
With reference to FIGS. 12-15 , the slide bearing box 30 includes an upper bearing assembly 90 and a lower mounting assembly 92 . The bearing assembly 90 includes a slide bearing 94 having a circular shape complimentary to that of the support shaft 32 . The slide bearing 94 is mounted within a box assembly 96 that is mounted to a base plate 98 by bolts and nuts. An upper bearing plate structure 100 extends downwardly from the base plate 98 . An upper structural frame 102 welded to the box assembly 96 and the base plate 98 and a lower structural frame 104 welded to the upper bearing plate structure 100 and the base plate 98 provide additional structural integrity.
The mounting assembly 92 includes a lower bearing plate structure 106 that extends upwardly from a base plate 108 , with a support frame 110 welded to the lower bearing plate structure 106 and the base plate 108 providing additional structural integrity. The base plate 108 is mounted to a truss platform 112 by bolts and nuts.
The upper and lower bearing plate structures 100 , 106 each include multiple bearing plates 114 , 116 , with each of the bearing plates 114 , 116 having a bearing surround opening 118 extending therethrough. The bearing plates 116 of the lower bearing plate structure 106 are disposed between bearing plates 114 of the upper bearing plate structure 100 such that the bearing plate openings 118 are aligned. A solid, cylindrical shaft 120 passes through openings 118 in each of the bearing plates 114 , 116 to connect the bearing assembly 90 to the mounting assembly 92 ( FIG. 14 ). A compression bearing 122 is positioned between each plate 114 , 116 of the upper and lower bearing plate structures 100 , 106 , with the shaft 120 extending through apertures 124 in each of the compression bearings 122 .
The main bearing structures 126 of the third tower 16 are best illustrated by referring FIGS. 16-23 . The bearing structure 126 includes a main slide bearing box 128 , a main support shaft 130 extending through the main slide bearing box 128 , a secondary slide bearing box 132 mounted at each end of the main support shaft 130 , two secondary support shafts 134 extending through each of the secondary slide bearing boxes 132 , and support boxes 136 mounted at either end of the secondary support shafts 134 . The two secondary slide bearing boxes 132 are substantially identical, the four secondary support shafts 134 are substantially identical, and all of the support boxes 136 are substantially identical. All of the support shafts 130 , 134 are solid steel shafts.
With reference to FIGS. 17-19 , the first and second end portions 138 , 140 of each secondary support shafts 134 are pinned within receptacles 142 of the support boxes 136 by steel bars 144 . A steel plate 146 is removably mounted in each support box 136 by bolts and nuts to further limit axial movement of the secondary support shafts 134 within the receptacle 142 . A steel frame 148 is fixedly mounted to a base plate 150 , preferably by welds.
With reference to FIGS. 20-21 , the secondary slide bearing box 132 includes an upper bearing assembly 152 and a lower support assembly 154 . The bearing assembly 152 includes two slide bearings 156 having a circular shape complimentary to that of the secondary support shafts 134 . The slide bearings 156 are each mounted within a box assembly 158 , mounted to a base plate 160 by bolts and nuts, such that the axes 162 of the slide bearings 156 are parallel. The first and second end portions 164 , 166 of the main support shaft 130 are each pinned within a receptacles 168 of the support assembly 154 of one of the secondary slide bearing boxes 132 by a steel bar 170 . A steel plate 172 is removably mounted in each support assembly 154 by bolts and nuts to further limit axial movement of the main support shaft 130 within the receptacle 168 . An upper structural frame 174 welded to the box assemblies 158 and the base plate 160 and a lower structural frame 176 welded to the support assembly 154 and the base plate 160 provide additional structural integrity. A 3-dimensional steel truss is mounted to the top of each bearing assembly 152 to connect the two secondary slide bearing boxes 132 ( FIG. 16 ).
With reference to FIGS. 22-23 , the main slide bearing box 128 includes an upper bearing assembly 180 , a lower mounting assembly 182 , and a base assembly 184 . The bearing assembly 180 includes a slide bearing 186 having a circular shape complimentary to that of the main support shaft 130 . The slide bearing 186 is mounted within a box assembly 188 that is mounted to a base plate 190 by bolts and nuts. An upper bearing plate structure 192 extends downwardly from the base plate 190 . An upper structural frame 194 welded to the box assembly 188 and the base plate 190 and a lower structural frame 196 welded to the upper bearing plate structure 192 and the base plate 190 provide additional structural integrity. The mounting assembly 182 includes a lower bearing plate structure 198 that extends upwardly from a base plate 200 , with a support frame 202 welded to the lower bearing plate structure 198 and the base plate 200 providing additional structural integrity. The base assembly 180 of the third tower 16 also includes a rotatable compressor bracket.
The upper and lower bearing plate structures 192 , 198 each include multiple bearing plates 204 , 206 , with each of the bearing plates 204 , 206 having a bearing surround opening 208 , extending therethrough. The bearing plates 206 of the lower bearing plate structure 198 are disposed between bearing plates 204 of the upper bearing plate structure 192 such that the bearing plate openings 208 are aligned. A solid, cylindrical shaft 212 passes through openings 208 in each of the bearing plates 204 , 206 to connect the bearing assembly 180 to the mounting assembly 182 . A compression bearing 214 is positioned between each plate 204 , 206 of the upper and lower bearing plate structures 192 , 198 , with the shaft 212 extending through apertures 216 in each of the compression bearings 214 .
The base assembly 184 includes a rotatable compression bracket 218 mounted within a steel support frame 220 . The compression bracket 218 includes a steel plate 222 disposed between upper and lower compression bearings 224 , 226 . The steel plate 222 is mounted to the base plate 200 of the mounting assembly 182 by recessed bolts and nuts. The support frame 220 is mounted to a truss platform 228 by bolts and nuts.
FIGS. 24-26 also show the subject solar power station 10 as the solar panel assembly 18 is being positioned to receive sun light at sunrise ( FIG. 24 ), the solar panel assembly 18 is being positioned to receive sun light at noon ( FIG. 25 ), and the solar panel assembly 18 is being positioned to receive sun light at sundown ( FIG. 26 ). In FIG. 24 , the first tower 12 is being extended 230 from the bottom position, as the second and third towers are held at the bottom position. The sliding bearing 94 of the first tower 12 moves 232 within the slide bearing box 30 from the right to left (with reference to the Figures), until the first tower 12 is fully extended. The sliding bearing 94 of the second tower 14 is maintained 234 at a rest position. The main slide bearing box upper bearing assembly 180 of the third tower 16 rotates clockwise 236 about the main slide bearing box shaft 212 , the compression bracket 218 rotates clockwise 238 , and the secondary support shafts 134 move 240 within the secondary slide bearing boxes 132 to compensate for the movement of the first tower 12 relative to the second and third towers 14 , 16 .
In FIG. 25 , the first tower 12 is retracted to the bottom position, as the second and third towers 14 , 16 are held at the bottom position. The sliding bearing 94 of the first tower 12 further moves 244 within the slide bearing box 30 from left to right, until the first tower 12 is fully retracted. The sliding bearing 94 of the second tower 14 is maintained 246 at the rest position. The main slide bearing box upper bearing assembly 180 of the third tower 16 rotates counter-clockwise 248 about the main slide bearing box shaft 212 , the compression bracket 218 rotates counter-clockwise 250 , and the secondary support shafts 134 move 252 within the secondary slide bearing boxes 132 to compensate for the movement of the first tower 12 relative to the second and third towers 14 , 16 .
In FIG. 26 , the second tower 14 is extended 254 from the bottom position, as the first and third towers 12 , 16 are held at the bottom position. The sliding bearing 94 of the second tower 14 moves 256 within the slide bearing box 30 from left to right, until the second tower 14 is fully extended. The sliding bearing 94 of the first tower 12 is maintained 258 at the rest position. The main slide bearing box upper bearing assembly 180 of the third tower 16 rotates counter-clockwise 260 about the main slide bearing box shaft 212 , the compression bracket 218 rotates counter-clockwise 262 , and the secondary support shafts 134 move 264 within the secondary slide bearing boxes 132 to compensate for the movement of the second tower 14 relative to the first and third towers 12 , 16 .
It should be appreciated that in the event that an earthquake senor 266 ( FIG. 53 ) detects ground vibration above a predetermined level, or a wind sensor 267 detects a wind force above a predetermined level, the hydraulic jack control 268 will withdraw all oil so that the three towers 12 , 14 , 16 are withdrawn to the bottom position, as shown in FIG. 25 . This minimizes the moment arm of the towers 12 , 14 , 16 , reducing the oscillation effect on the solar power station 10 . The shock absorbers 54 of the first and second towers 12 , 14 also absorb the horizontal component of vibration produced by external force such as wind and earthquake.
As shown in FIG. 27 a , the shock absorbers 54 of the second support boxes 36 of the first and second towers 12 , 14 maintain the second support boxes 36 at a nominal contact distance 270 from the side of the associated slide bearing box 30 when the main bearing structures 28 , 28 ′ are not exposed to an external horizontal force.
When the main bearing structures 28 , 28 ′ are exposed to an external horizontal force 272 from the right (as shown in FIG. 27 b ), the force 272 moves 274 the first and second support boxes 34 , 36 and the support shaft 32 of both main bearing structures 28 , 28 ′ to the left. The spring 88 of the shock absorber 54 of the second support box 36 of main bearing structure 28 of the first tower 12 is compressed and the spring 88 of the shock absorber 54 of the second support box 34 of main bearing structure 28 ′ of the second tower 14 is extended, absorbing the force 272 . At the point where force 272 and the compression force of the spring 88 of main bearing structure 28 and the tension force of the spring 88 of main bearing structure 28 ′ are at equilibrium, the second support box 36 of the first tower 12 is at a minimum contact distance 276 from the side of the associated slide bearing box 30 and the second support box 36 of the second tower 14 is at a maximum contact distance 278 from the side of the associated slide bearing box 30 . When the force 272 is removed, the compression force of the spring 88 of main bearing structure 28 and the tension force of the spring 88 of main bearing structure 28 ′ return the first and second support boxes 34 , 36 and the support shaft 32 of both main bearing structures 28 , 28 ′ to the positions shown in FIG. 27 a.
Similarly, when main bearing structures 28 , 28 ′ are exposed to an external horizontal force 280 from the left (as shown in FIG. 27 c ), the force 280 moves 282 the first and second support boxes 34 , 36 and the support shaft 32 of both main bearing structures 28 , 28 ′ to the right. The spring 88 of the shock absorber 54 of the second support box 36 of main bearing structure 28 ′ of the second tower 14 is compressed and the spring 88 of the shock absorber 54 of the second support box 36 of main bearing structure 28 of the first tower 12 is extended, absorbing the force 280 . At the point where force 280 and the compression force of the spring 88 of main bearing structure 28 ′ and the tension force of the spring 88 of main bearing structure 28 are at equilibrium, the second support box 36 of the second tower 14 is at a minimum contact distance 284 from the side of the associated slide bearing box 30 and the second support box 36 of the first tower 12 is at a maximum contact distance 286 from the side of the associated slide bearing box 30 . When the force 280 is removed, the compression force of the spring 88 of main bearing structure 28 ′ and the tension force of the spring 88 of main bearing structure 28 return the first and second support boxes 34 , 36 and the support shaft 32 of both main bearing structures 28 , 28 ′ to the positions shown in FIG. 27 a.
Each of the towers 12 , 14 , 16 includes multiple, vertically stacked floors 288 ( FIG. 28 ). Each floor 288 includes an arrangement of robots R 1 , R 2 , R 3 , R 4 and a connecting framework of push and pull steel frames F 1 , F 2 . More specifically, the robots R 1 , R 2 , R 3 , R 4 and steel frames F 1 , F 2 are organized in groups, HR 1 , HR 2 , HR 3 , VR 1 , VR 2 , VR 3 , VR 4 , with the associated robots and steel frames of each group being connected together. The robots R 1 , R 2 , R 3 , R 4 of each intermediate floor 288 are connected to associated robots in each floor 288 , 288 ″ above it and each floor 288 , 288 ′ below it. Groups HR 1 and VR 1 are identical, each including three R 3 robots and four R 4 robots. The HR 2 and VR 2 groups are almost identical, each including three R 1 robots, one R 2 robot, and one R 4 robot. HR 2 also includes four double deck steel frames F 1 , while VR 2 also includes three single deck steel frames F 2 and one double deck steel frame F 1 . The HR 3 group includes three R 1 robots and two R 3 robots. The VR 3 group includes four R 1 robots and three R 3 robots. The VR 4 group includes three R 1 robots and one R 4 robot. For the ground floor 288 ′, the R 1 robots are vibration hydraulic jacks with springs, while for all of the other floors 288 , the R 1 robots are hydraulic jacks.
With reference to FIGS. 45 to 49 , the ground floor 288 ′ includes an outer, space frame ring 596 which is designed to resist lateral force exerted on the towers 12 , 14 , 16 by strong wind or earthquakes, and thereby prevent tension, bearing and torsion forces from pulling the robot groups HR 1 , HR 2 , HR 3 , VR 1 , VR 2 , VR 3 , VR 4 out of the space frame ring 596 . The space frame ring 596 comprises a framework including supporting members 598 , first bracing members 600 , vertical members 602 , second bracing members 604 , first gusset plates 606 , horizontal members 608 , second gusset plates 610 , and bracket 612 that are fastened together by bolts and nuts. The footing of supporting members 598 and the footing of vertical members 602 are fastened to a base member 614 which is in turn fastened to the foundation 616 , preferably by nuts and bolts. A solid rod or pole 618 extends vertically upward from a foot fixed within a bottom flange 620 mounted to the base member 614 , through a lower spring 622 , an upper flange 624 having a lower flange half 626 and an upper flange half 628 , an upper plate 630 clamped between the lower and upper flange halves ( 626 , 628 ), an upper spring 632 , to a head fixed within an opening in the bracket 612 . The top end of the upper spring 632 engages the lower surface of the bracket 612 and the bottom end of the upper spring 632 engages the top surface of the upper flange half 628 . The top end of the lower spring 622 engages the lower surface of the lower flange half 626 and the bottom end of the lower spring 632 engages the top surface of the bottom flange 620 . In the event of a strong wind or earthquake, the upper plate 630 can move vertically upward and downward along the pole 618 such that the upper and lower springs 632 622 absorb the shock energy generated by lateral forces exerted on the tower by the wind or the earthquake.
FIGS. 48 and 49 illustrate the ground floor 288 ′ and a typical floor connection. The ground floor base member 614 is connected to the tie beam members 634 of the upper plate 630 by the ground floor pole 618 , which is mounted to the piling or foundation 616 and extends through the upper flange 624 mounted to the upper plate 630 . The ground floor robot groups HR 1 , HR 2 , HR 3 , VR 1 , VR 2 , VR 3 , VR 4 are mounted to the tie beam members 636 of the ground floor base member 614 and to the tie beam members 634 of upper plate 630 of the ground floor 288 ′. The tie beam members 634 are mounted to the upper plate 630 by gusset plates and by bolts and nuts or welds. The connections for the upper floors 288 are the same as described above for the ground floor 288 ′, where the upper plate 630 of each lower floor acts as the base member of each subsequent floor. For example, the robot groups HR 1 , HR 2 , HR 3 , VR 1 , VR 2 , VR 3 , VR 4 of the second floor are mounted to the tie beam members 634 of the upper plate 630 of the ground floor 288 ′ and to the tie beam members 634 ′ of the upper plate 630 ′ of the second floor.
FIG. 29 is an enlarged view of the HR 1 and VR 1 groups of FIG. 28 . Each HR 1 and VR 1 group includes four R 4 robots 640 , 642 , 644 , 646 and three R 3 robots 648 , 650 , 652 . FIG. 30 is an enlarged view of the HR 3 group of FIG. 28 . Each HR 3 group includes three R 1 robots 654 , 656 , 658 and two R 3 robots 660 , 662 . FIG. 31 is an enlarged view of the VR 3 group of FIG. 28 . Each VR 3 group includes four R 1 robots 664 , 666 , 668 , 670 and three R 3 robots 672 , 674 , 676 . FIG. 32 is an enlarged view of the HR 2 group of FIG. 28 . Each HR 2 group includes three R 1 robots 318 , 322 , 326 , one R 4 robot 332 , and one R 2 robot 678 . FIG. 33 is an enlarged view of the VR 2 group of FIG. 28 . Each VR 2 group includes three R 1 robots 334 , 336 , 338 , one R 4 robot 340 , and one R 2 robot 680 . FIG. 50 is an enlarged view of the VR 4 group of FIG. 28 . Each VR 4 group includes three R 1 robots 334 ′, 336 ′, 338 ′ and one R 4 robot 340 ′.
The R 1 , R 2 , R 3 , and R 4 robots all have a horizontal roller frame 290 , 292 , 304 , 308 on each side of the robot. The R 1 robots also have a pair of hydraulic jacks 294 is mounted to each of the horizontal roller frames 290 . More specifically, a first end 298 of both hydraulic jacks 296 of each pair 294 is mounted to the first end 300 of the respective horizontal roller frame 290 .
For the HR 1 and VR 1 groups ( FIG. 29 ), the R 3 robots are disposed between the R 4 robots, with the first ends 306 of the horizontal roller frames 304 of the R 3 robots being connected to the first ends 310 of the horizontal roller frames 308 of the adjacent R 4 robots.
For the HR 3 group ( FIG. 30 ), the R 3 robots are disposed between the R 1 robots, with the first ends 306 of the horizontal roller frames 304 of the R 3 robots being connected to the first ends 300 of the horizontal roller frames 290 of the adjacent R 1 robots, and a pair of hydraulic jacks 294 being disposed between the R 1 robot and the R 3 robot.
For the VR 3 group ( FIG. 31 ), the R 3 robots are disposed between the R 1 robots, with the first ends 306 of the horizontal roller frames 304 of the R 3 robots being connected to the first ends 300 of the horizontal roller frames 290 of the adjacent R 1 robots, and a pair of hydraulic jacks 294 being disposed between the R 1 robot and the R 3 robot.
For the HR 2 group ( FIG. 32 ), the three R 1 robots 318 , 322 , 326 are adjacent, one R 4 robot 332 is disposed at one end of the group of R 1 robots, and one R 2 robot 678 mounted to R 1 robot 318 . The first ends 302 of the extended double deck steel frame segments 291 of the horizontal roller frames 292 of the R 2 robot are connected to the first ends 300 of the horizontal roller frames 290 of R 1 robot 318 . A first end 312 of a first double deck steel frame F 1 314 is connected to the second end 316 of the horizontal roller frames 290 of the first R 1 robot 318 and the second end 320 of the first steel frame F 1 314 is connected to the first end 300 of the horizontal roller frames 290 of the second R 1 robot 322 . Similarly, the first end 312 of the second steel frame F 1 324 is connected to the second end 316 of the horizontal roller frames 290 of the second R 1 robot 322 , the second end 320 of the second steel frame F 1 324 is connected to the first end 300 of the horizontal roller frames 290 of the third R 1 robot 326 , the first end 312 of the third steel frame F 1 328 is connected to the second end 316 of the horizontal roller frames 290 of the third R 1 robot 326 , and the second end 320 of the third steel frame F 1 328 is connected to the second end 330 of the horizontal roller frames 308 of the R 4 robot 332 .
The VR 2 group ( FIG. 33 ) and VR 4 group ( FIG. 50 ) are very similar, each of the groups having three adjacent R 1 robots 334 , 336 , 338 , 334 ′, 336 ′, 338 ′ and one R 4 robot 340 , 340 ′ that is disposed at one end of the group of R 1 robots. A first end 342 of a first single deck steel frame F 2 344 is connected to the second end 316 of the horizontal roller frames 290 of the first R 1 robot 334 , 334 ′ and the second end 346 of the first steel frame F 2 344 is connected to the first end 300 of the horizontal roller frames 290 of the second R 1 robot 336 , 336 ′. Similarly, the first end 342 of the second steel frame F 2 348 is connected to the second end 316 of the horizontal roller frames 290 of the second R 1 robot 336 , 336 ′, the second end 346 of the second steel frame F 2 348 is connected to the first end 300 of the horizontal roller frames 290 of the third R 1 robot 338 , 338 ′, the first end 342 of the third steel frame F 2 350 is connected to the second end 316 of the horizontal roller frames 290 of the third R 1 robot 338 , 338 ′, and the second end 346 of the third steel frame F 2 350 is connected to the second end 330 of the horizontal roller frames 308 of the R 4 robot 340 , 340 ′. The VR 2 group ( FIG. 33 ) also has one R 2 robot 680 disposed at the second end of the group of R 1 robots, with the first ends 302 of the extended double deck steel frame segments 291 of the horizontal roller frames 292 of the R 2 robot being connected to the first ends 300 of the horizontal roller frames 290 of R 1 robot 334 .
As shown in FIGS. 34 a - 34 d , the single deck steel frames F 2 of the VR 2 groups passes through the gap 351 formed by the steel members 352 of the double deck steel frames F 1 of the HR 2 groups. In FIGS. 34 b and 34 d , hydraulic fluid has been pumped into the hydraulic jacks 296 of the HR 1 , HR 2 , HR 3 , VR 1 , VR 2 , VR 3 and VR 4 groups, pushing the second ends 354 of the hydraulic jacks 296 away from each other and thereby pushing the floors away from each other. This causes the towers to extend from the bottom position 22 . As the second ends 354 of the hydraulic jacks 296 are pushed away from each other, the horizontal roller frames 290 , 308 move 356 from right to left direction, the VR 1 , VR 3 and HR 2 groups producing movement in the X direction and the HR 1 , HR 3 , VR 4 and VR 2 groups producing movement in the Y direction ( FIG. 1 ). In FIGS. 34 a and 34 c , hydraulic fluid has been released from the hydraulic jacks 296 of the HR 1 , HR 2 , HR 3 , VR 1 , VR 2 , VR 3 and VR 4 groups, allowing the weight of the floor to push the second ends 354 of the hydraulic jacks 296 towards each other, causing the towers to retract to the bottom position 22 .
With reference to FIGS. 51 a and 51 b , the arrangement of the VR 2 and HR 2 groups of the ground floor 288 ′ is the same as described above, except that the hydraulic jacks of robots R 1 are replaced with a vibration hydraulic jack with spring 484 . The ground floor 288 ′ has a special function. When a great wind force or earthquake occurs, the ground floor hydraulic jacks with springs 484 will absorb the energy. If the vibration force exceeds the absorption capacity of the hydraulic jacks with springs 484 at their rest supporting stage, the vibration force will push the robot groups in HR 2 and VR 2 down from top to bottom level, the horizontal roller frames 292 , 290 , 308 move from left to right. Finally the R 1 robot transfers the energy force through the push and pull frame F 1 and F 2 to the adjacent R 1 robots and into the R 2 robot. The HR 2 group transfers the x-direction force to the end of group, at the same time the VR 2 group transfers the y-direction force to the end of group. The floorwill be pushed down uniformly to the same level at the same time until the hydraulic jacks with springs 484 of the HR 2 and VR 2 groups absorb all the energy. When the vibration force is removed, the hydraulic jacks with springs 484 will push the HR 2 and VR 2 groups back to original position.
FIGS. 35-43 are external and internal views of robots R 1 , R 3 , R 4 and R 5 showing the relationship of the robot components as they move from the bottom position to the extended position. Movement of the robots R 1 , R 3 , R 4 and R 5 is controlled by the hydraulic jacks. For robots R 1 , each hydraulic jack 296 has a first end 298 connected to a shaft extending through the side of horizontal roller frame 290 and a second end 354 having a base 358 . For robots R 5 , each vibration hydraulic jack with spring 484 has a first end 486 connected to a shaft extending through the side of horizontal roller frame 488 and a second end 490 having a base 492 .
An upper arm 360 , 388 , 420 , 452 has a first end connected to an upper clipper 362 , 390 , 422 , 454 and the second end connected to a roller 364 , 392 , 424 , 456 and a lower arm 366 , 394 , 426 , 458 has a first end connected to a lower clipper 368 , 396 , 428 , 460 and a second end connected to the roller 364 , 392 , 424 , 456 . Each horizontal roller frame 290 , 308 , 304 , 488 includes two frame members 369 , 398 , 430 , 462 that are mounted together at each end by a pair of mounting members 371 , 400 , 432 , 464 . The roller 364 , 392 , 424 , 456 extends through a slot 370 , 402 , 434 , 466 formed between the two frame members 369 , 398 , 430 , 462 and is locked therein by a washer 372 , 404 , 436 , 468 mounted to the roller 364 , 392 , 424 , 456 .
When the robots are extended, the upper clipper 362 , 390 , 422 , 454 is pushed upward and lower clipper 368 , 396 , 428 , 460 is pushed downward, and the upper arm 360 , 388 , 420 , 452 and lower arm 366 , 394 , 426 , 458 urge roller 364 , 392 , 424 , 456 away from the first end 300 , 310 , 306 , 494 of the horizontal roller frame 290 , 308 , 304 , 488 toward the second end 316 , 330 , 307 , 496 of the horizontal roller frame 290 , 308 , 304 , 488 . An upper cable clevis 374 , 406 , 438 , 470 is fixed on the shaft between the upper base 376 , 408 , 440 , 472 and the upper clipper 362 , 390 , 422 , 454 and a lower cable clevis 378 , 410 , 442 , 474 is fixed on the shaft between the lower base 380 , 412 , 444 , 476 and the lower clipper 368 , 396 , 428 , 460 . A first end of secondary cable 382 , 414 , 446 , 478 is fastened to the main cable 384 , 416 , 448 , 480 by a clip 385 ( FIG. 43 ) and the second end is fastened to the retractable cable reel 386 , 418 , 450 , 482 .
When the robots retract, the upper clipper 362 , 390 , 422 , 454 is pushed downward, the lower clipper 368 , 396 , 428 , 460 is pushed upward, and the secondary cable 382 , 414 , 446 , 478 is rolled onto the retractable cable roller 386 , 418 , 450 , 482 , pulling the secondary cables 382 , 414 , 446 , 478 and the main cables 384 , 416 , 448 , 480 .
FIG. 40 shows a locking device 548 for locking the upper clipper 362 to the lower clipper 368 . The locking device 548 includes a shaft 550 that is reciprocally moved by a hydraulic jack 552 . The end of the hydraulic jack 552 is mounted to the shaft 550 by a pin 554 that passes through a pair of angles 556 and a slot in the jack shaft 558 . The angles 556 are mounted to the shaft 550 . The jack body 560 is mounted to the lower clipper 368 by a pin 562 that passes through plates 564 , mounted to another pair of angles 566 , and the jack body 560 . The angles 566 are mounted to the guide 568 . Three guides 568 , 570 , 572 are mounted to the lower clipper 368 and one guide 574 is mounted to the upper clipper 362 for guiding and receiving the shaft 550 . The shaft 550 extends through the first and second guides 568 , 570 in both the unlocked and locked positions. When Robot R 1 and R 4 are in the bottom position, the fourth guide 574 mounted to the upper clipper 362 aligns with the first, second and third guides 568 , 570 , 572 mounted to the lower clipper 368 . At this time, the hydraulic jack 552 may be actuated to extend the jack shaft 558 and the shaft 550 through the fourth guide 574 and into the third guide 572 , thereby locking the upper clipper 362 to the lower clipper 368 . To extend Robot R 1 and R 4 , the hydraulic jack 552 must again be actuated to withdraw the jack shaft 558 and the shaft 550 from the third and fourth guides 572 , 574 .
As shown in FIG. 41 , the cable reel 386 , 418 , 450 , 482 , includes a pair of coil springs 576 , 578 . Each coil spring 576 , 578 has a first end fixed to a wall of an internal cylinder 580 of recess wheel 582 by bolt and nut that pass through the recess wheel 582 and then fix to the shaft 584 , the second end is fixed to the external cylinder 586 by bolt and nut. The internal and external cylinders 580 , 586 are mounted to a center nut 588 . The center nut 588 has a recess 590 having an opening 592 through which passes the secondary cable 382 , 414 , 446 , 478 . A lock 594 holds the secondary cable 382 , 414 , 446 , 478 .
FIGS. 44 and 52 are external and internal views of robot R 2 showing the relationship of the robot components as they move from the bottom position to the extended position. Movement of the robots R 2 is controlled by the hydraulic jacks of the robots R 1 .
Robot R 2 comprises a first pair of clipper assemblies 497 , each of the clipper assemblies 497 including an upper arm 498 having a first end connected to an upper clipper 500 and a second end connected to a roller 502 , and a lower arm 504 having a first end connected to a lower clipper 506 and a second end connected to the roller 502 . The roller extends through a slot formed in each horizontal roller frame 292 . The second end 301 of the extended double deck frame F 1 291 is connected to the roller 502 . The first ends of the upper and lower clippers 500 , 506 each have a base 508 , 510 and the second ends of the upper and lower clippers 500 , 506 are each connected to a shaft 512 , 514 by a slot plate 516 . Slot plate 516 is mounted to the second end 518 of horizontal roller frame 292 by fixed plate 520 and bracket frame 522 by bolts and nuts. The shafts 512 , 514 are locked to the slot plate 516 by round disk lockers. The upper clipper 500 is fixed to an upper transverse frame 524 and the lower clipper 504 is fixed to a lower transverse frame 526 .
Robot R 2 also comprises a second pair of clipper assemblies 528 , each of the clipper assemblies 528 including upper and lower clippers 530 , 532 . The first ends of the upper and lower clippers 530 , 532 each have a base 534 , 536 and the second ends of the upper and lower clippers 530 , 532 are each connected to a shaft 538 , 540 by a pair of slot plates 542 . Slot plates 542 are mounted to the first end 302 of horizontal roller frame 292 by fixed plate 544 and by bolts and nuts. The shafts 538 , 540 are locked to the slot plate 542 by round disk lockers. The upper clipper 530 is fixed to an upper transverse frame 524 ′ and the lower clipper 532 is fixed to a lower transverse frame 526 ′.
When the robots are extended, the upper clippers 500 , 530 are pulled upward and lower clippers 506 , 532 are pulled downward, and the upper arm 498 and lower arm 504 urge roller 502 away from the first end 302 of the horizontal roller frame 292 toward the second end of the horizontal roller frame 292 ( FIG. 52 ). When the extended double deck frame F 1 291 engages the panel 546 connected to the horizontal roller 502 , the robot R 2 has reached its maximum extension and the floor is locked at the maximum height, preventing over extension of the robots.
While preferred embodiments have been shown and described, various modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustration and not limitation.
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A solar power station includes a solar panel assembly, having a substantially planar solar panel, and first, second and third towers. Each of the towers includes multiple vertically stacked floors and a main bearing structure pivotally mounting the solar panel assembly to the tower upper end. Each of the floors includes an arrangement of robots that are connected to each vertically adjacent floor. At least some of the robots including hydraulic jacks. A controller selectively actuates the hydraulic jacks, such that each of the towers is individually extendable from a bottom position to an extended position. Selectively moving one or more of the towers rotates the solar panel about one or both of the axes, whereby the solar panel is maintained at an optimal orientation for collecting solar power.
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TECHNICAL FIELD OF THE INVENTION
It is an object of the instant invention to provide a new woven ribbon, notably for a belt, thong, strap, handbag handle or watch wristlet, at least one extremity of which is designed to be secured at an adjustable distance to a buckle with a tang.
BACKGROUND TO THE INVENTION
At the present time when one makes an object or an article, such as those which have just been mentioned, using a woven ribbon, one does not content himself with making holes in this ribbon to permit passage of the tang.
Indeed, in order to enable the tang to be easily introduced into the holes at all times without risk of missing them, and to enable the fabric to stand up effectively to the pulling of the tang, it is necessary for the material to be composed of very stiff and very close-woven threads.
It is correct to say that it is always desirable or necessary for the object or article in question to be sufficiently stiff widthways, but not lengthways.
DESCRIPTION OF THE PRIOR ART
As a result, a fabric is chosen which makes it possible to fulfil this dual requirement of rigidity in width and pliancy in length, subsequently adopting one of the two following possibilities:
The first is to actually pierce holes in the woven ribbon and to surround these with eyelets.
The second is to fix to the end of the ribbon a band in a more resistant material then said ribbon, for example in natural or synthetic leather, and to pierce holes therein.
These two solutions have two disadvantages in common: they notably increase the cost of the object or the article and they do not permit a fine adjustment of the length thereof due to the relatively long gaps which must, nevertheless, be provided between the holes.
In addition, the first solution has another disadvantage. Namely, by interrupting the continuity of the position of the warp and weft threads, the holes weaken the mechanical resistance of the ribbon.
It has previously been proposed in French patent No. 1 512 865 which was filed on Feb. 28, 1967 to produce a ribbon having weft threads arranged substantially equidistantly along the width and warp threads along the length thereof and to provide a straight longitudinal zone totally devoid of warp threads for the passage of a tang and this specifically in order to eliminate the disadvantages of the first solution mentioned above. However the prior proposal suffers from the disadvantage that it does not give any details regarding the nature of the threads and the special mode or modes of weaving which must be employed in order to make the ribbon in question meet all the stated requirements. This earlier ribbon may, according to the inventor thereof, have any structure, but it is quite clear that this is not true. If this were so, ribbons of this type or articles made using them would doubtless have been on the market for a long time.
BRIEF SUMMARY OF THE INVENTION
It is an object of the instant invention to provide a solution which makes it possible to develop and improve the underlying concept of French patent No. 1 512 865 to an effective realization thereof.
It is also an object of the instant invention to provide a ribbon which may be manufactured in very large numbers and at a very low cost price.
These objects are achieved according to the invention, by providing a ribbon which also comprises weft threads and warp threads disposed respectively along the width and along the length thereof, and which also presents in a narrow part of its width at least one zone adapted to be secured to the buckle with a tang in which the weaving is less closely woven than elsewhere, but without the warp threads necessarily being absent form this zone, the weft threads being threads which are at least partially composed of synthetic material and which are appreciable stiffer than the warp threads. Moreover, the ribbon is woven in such a way that the weft threads are joined in pairs of adjacent threads by the warp threads.
The weft threads thus confer to the ribbon the desired stiffness in width and the warp threads its pliancy in length.
Moreover, there are two advantages in joining the weft threads in pairs:
Firstly, these pairs are more resistant to the pulling of the tang than if they were regularly distributed along the direction of the length of the ribbon, as is the case in the above mentioned French patent.
Secondly, in this manner one creates small spaces between the pairs into which the tang can easily penetrate, while continuing to provide the possibility of virtually continuous adjustment along the length of the ribbon.
As regards the weft threads, it is often preferable to use solid threads entirely of synthetic material, but one can also in certain cases resort to composite threads composed of a core of natural fiber and a sheath of synthetic material.
As regards the warp threads the choice is very great. One may for example use threads composed of very fine clusters of fibers and/or slightly twisted, natural or artificial fibers.
In addition, to obtain a less close-woven weave in the narrow part one can for example arrange that the warp threads in that portion are less close to one another than in the other parts or that the weft threads pass in this area from the same side as the warp threads.
If one opts for the solution which consists in not providing warp threads in the narrow part one can weave on both sides thereof a warp thread that is solid, thin and stiff or a pair of adjacent threads of this type which pass alternately from one side to the other of consecutive pairs of weft threads. In so doing, one accentuates the stiffness of the weft threads in the central region of the ribbon and one prevents the other warp threads, which are much more pliant, from spreading into the narrow part.
Finally, it is obvious that one can very greatly vary the appearance of the ribbon by using threads of different colours and different modes of weaving.
Other features and advantages of the ribbon according to the invention will appear from a study of the following description of four possible embodiments which are chosen simply for purposes of example and which are particularly well adapted for use in a watch wristlet.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of a first embodiment of the invention;
FIG. 1A is a sectional view taken along line A--A of FIG. 1;
FIG. 1B is a sectional view taken along line B--B of FIG. 1;
FIG. 2 is a plan view of a second embodiment of the invention;
FIG. 2A is a sectional view taken along line A--A of FIG. 2;
FIG. 2B is a sectional view taken along line B--B of FIG. 2;
FIG. 3 is a plan view of a third embodiment of the invention;
FIG. 3A is a sectional view taken along line A--A of FIG. 3;
FIG. 4 is a plan view of a fourth embodiment of the invention; and,
FIG. 5 illustrates a portion of a wristlet utilizing the invention.
DETAILED DESCRIPTION OF THE INVENTION
The weft of the ribbon shown in FIG. 1 is composed of a single thread 1 which is continuous, thin, solid and of a resilient synthetic material. The thread 1 is folded back on itself succesively on each of the edges of the ribbon in turn as is apparent in particular at 2 and 3, on the edge of the underside of the ribbon. In so doing it forms pairs of adjacent weft threads 4, 5, all regularly spaced as is evident from FIG. 1A. Every other pair is visible.
The warp of the ribbon is formed of two superimposed layers of threads, each formed of very fine fibers that are in clusters and/or slightly twisted. Only those in the upper layer such as threads 6 and 7 are visible in FIG. 1. As shown in FIGS. 1A and 1B the warp thread 6 of the upper layer passes alternately above three consecutive pairs of adjacent weft threads, such as 4 1 , 5 1 , 4 2 , 5 2 , and 4 3 5 3 then under the next pair of weft threads. Alternate threads of this upper layer pass over and under the same pairs of adjacent weft threads as the thread 6. As shown in FIG. 1B, the thread 7 passes alternately under the pair of adjacent weft threads 4 2 , 5 2 which is located in the middle of those over which the thread 6 passes, then over the three following consecutive pairs of adjacent weft threads 4 3 , 5 3 , 4 4 , and 5 4 and 4 5 , 5 5 As shown in FIGS. 1A and 1B warp threads 30 and 31 of the lower layer each passes alternately over the pair of adjacent weft threads located in the middle of those over which there passes a warp thread of the upper layer, then under the three following pairs of adjacent weft threads. Thus, in FIG. 1A warp thread 30 passes over the pair of weft threads 4 2 , 5 2 and then under the pairs of weft threads 4 3 , 5 3 , 4 4 , 5 4 , and 4 5 , 5 5 while in FIG. 1B warp thread 31 passes over the pair of weft threads 4, 5 and then under the pairs of weft threads 4 1 , 5 1 , 4 2 , 5 2 and 4 3 , 5 3 . The parts of the warp threads of the lower layer which pass over a pair of adjacent weft threads are covered by the warp threads of the upper layer which pass over this same pair of weft threads, as well as over the two neighbouring pairs. Similarly, the warp threads of the lower layer which pass under three successive pairs of adjacent weft threads hide the parts of the warp threads of the upper layer which pass under a single pair of the adjacent weft threads.
The warp threads are closely packed together except for the two threads 8 and 9 which are located in the middle of the width of the ribbon. As shown in FIG. 1 the space which they occupy is almost as wide as that occupied by three other adjacent warp threads.
A tang 32 (FIG. 5) to which one of the ends of the described ribbon is designed to be secured and which is located in the middle of the width of the ribbon may thus create a path between the two warp threads 8, 9 and between the two consecutive pairs of adjacent weft threads without damaging either the one or the other of these groups of threads. Since the pairs of consecutive weft threads are relatively close to one another, the described ribbon facilitates fine adjustment of its active length.
The ribbon of FIG. 2 is mainly distinguished from that of FIG. 1 by the fact that it presents, in the middle of its width, a narrow part 10 which is solely occupied by weft threads 11. The tang 32 (FIG. 5) to which one extremity of the ribbon is designed to be secured, naturally engages itself in the free spaces between threads 11. Although threads 11 are made up of segments, folded back in zig zag form all along the ribbon, of a single and same thread, identical to that of FIG. 1 they are grouped here in triplets 12 of consecutive pairs of adjacent threads as shown in FIG. 2A. Pairs of a triplet 12 are closer to each other than are the triplets amongst themselves. This is shown in FIG. 2A where the pairs of a triplet 12 are closer together than the distance between the right-most pair of triplet 12 the left-most pair of the next triplet 12 1 .
The nature and the weave of the warp threads 13 are identical to those of FIG. 1. Nevertheless, two means are provided to prevent the warp threads 13 from spreading into the part 10 of the ribbon and to confer to the weft threads of this part 10 a stiffness enabling them to suitably resist the pulling forces exerted thereon by the tang, to which one extremity of the ribbon is designed to be secured.
The first of these means consists of a pair of adjacent warp threads 14 that are solid, thin and stiff, of synthetic material, and which extend the length of each of the edges of part 10. Each thread 14 passes alternately from one to the other side of the consecutive pairs of adjacent weft threads.
The second means consists of the special weaving of the two warp threads 15, 16 alongside threads 14, on each side of the part 10. The thread 15 (FIG. 2A) passes successively from one to the other side of the consecutive triplets 12, 12 1 . The thread 16 (FIG. 2B) passes in turn from one to the other side of each consecutive pair of adjacent weft threads. The threads 15, 16 are of the same nature as the threads 13.
The embodiment shown in FIG. 3 is mainly distinguished from that of FIG. 2 by the fact that the two layers of warp threads 15 1 , 16 1 of different colors, pass simultaneously and from place to place from one side to the other of the weft as shown in FIG. 3A. The ribbon therefore presents segments 17, 18 of alternating colors.
In this case, and as is shown in FIG. 3, the two adjacent solid, thin and stiff warp threads 14 which extend along one edge and the other edge of the narrow median part 19 of the ribbon, pass the one from the one side and the other from the other side of successive pairs 20 of adjacent weft threads 21, 22 which, in this embodiment, are regularly spaced amongst each other.
In the embodiment shown in FIG. 4 the weaving is identical to that in FIG. 2. On both sides of the narrow central part 23 of the ribbon there is, however, only one single, solid, thin and stiff warp thread 24 which passes successively from one side to the other of the consecutive pairs of adjacent weft threads. Moreover, some warp threads from the central zone 25 of the ribbon have visibly the same color as the weft threads, so as to camouflage these latter which occupy the narrow part 23, whereas the outer warp threads, zones 26 and 27, have a different color.
The ribbon of this last embodiment illustrates another very simple way of varying the appearance.
In the four embodiments shown in the drawing, the central part of the ribbon which is less close-woven naturally extends the full length of the ribbon. It is, nevertheless, possible to limit this special weave to that zone of the ribbon which is specifically designed to be secured to the tang in question. For this purpose it is sufficient to pass the weft threads of this zone on the same side of the two, three or four warp threads located in the middle of the width of the ribbon or between the same warp threads of the two superimposed layers. The tang could then pass through this zone of the ribbon, engaging between the weft threads and the free warp threads in the weft without risk of damaging either the one or the other of these threads.
Generally, the fixing of a buckle 34 having a tang 32, as illustrated in FIG. 5, to one extremity of the ribbon according to the invention presents no difficulty. It suffices to engage this extremity of the ribbon in the buckle or a part thereof, to fold it over the rest of the ribbon and to fix it to the latter, for example by means of one or several rivets. It can also be fixed thereto by fusing, sewing or glueing. If all the threads of the ribbon and the buckle are of a synthetic material, the extremity of the ribbon may even be fused directly onto the buckle.
Moreover, when the invention is used for example in the manufacture of watch wristlets it is not essential to limit the weave to each strand of the individual strap. One can also weave a long band, the width of which is a multiple of that of the strands of the wristlet to be manufactured providing at various places across this band narrow parts where the weave is less close-woven than elsewhere, as described above, the spacing of which corresponds to the width of the wristlets, and then to cut these latter into the said band of the desired length.
If the weft thread is of an entirely synthetic material, the widthwise cutting of the strands of the wristlets may advantageously be effected under heat, for example, ultrasonically. This procedure would at the same time effect the fusing together of the extremities of the weft threads along the edges of the wristlet.
If, on the other hand, these threads are mixed, that is if they are composed of a natural fiber core, for example cotton, sheathed in synthetic material, for example PVC, the cutting could be effected by high frequency, which would at the same time ensure the fusing together of the ends of these threads.
The fixing of the strands of the wristlet to the lugs of the watch casing can be effected in analagous manner to those described above, to a buckle. The strand of the wristlet extending from the watch casing to the buckle with tang does not of course need to present a straight central part that is less close-woven except in order to preserve the continuity in the appearance of the wristlet.
What has been said above with regard to the manufacture per se of watch wristlets can naturally apply to the production of other articles.
Moreover, it is quite clear that the invention also applies to ribbons designed to be associated with buckles having several tangs.
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A ribbon comprises weft threads (11) and warp threads (13) arranged respectively along the width and the length thereof and presenting in a narrow part (10) of its width at least one zone designed to be secured to a buckle, in which the weave is less close-woven than elsewhere to permit virtually continuous adjustment along its length. The weft threads are threads which are at least partially made from synthetic material and which are appreciably stiffer than the warp threads. The weft threads are joined in pairs of adjacent threads by the warp threads.
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BACKGROUND OF THE INVENTION
The present invention refers to a screening apparatus for sorting and classifying fluid flows, and in particular to a bar screen, especially for sorting fiber suspensions, and being of the type having a plurality of parallel bar-shaped screen elements mounted on cross bars for forming a screen area and defining slotted screening perforations therebetween which extend essentially transversal to the direction of the fluid flow.
It is known to provide bar screens with triangular screen elements, with their top surface, which faces the incoming fiber suspension, being levelled or flat so as to form a plane screen area. Practice has shown however, that the provision of irregular screening surfaces is advantageous for improving the screening capacity and sorting quality because of the hydrodynamic effect of the screen and the generation of so-called microturbulences. It was thus proposed to slantingly position the screen elements so that their top surface is angled relative to the screen area. In this manner, an approximately stepped screening surface is created.
For manufacturing reasons, the angle of inclination of the screen elements is limited so that the depth of the thus non-levelled screening surface is also limited. Theoretically, the depth could be increased by expanding the width of the screen element, however, such measure would result in a loss of free surface area, thus causing a reduced throughput. Moreover, a slanted arrangement of the screen elements in order to attain an irregular screening area is disadvantageous because it results at the outlet side of the screen in an asymmetric flow space which adversely affects the fluid flow and causes pressure losses.
SUMMARY OF THE INVENTION
It is thus an object of the present invention to provide an improved screening apparatus obviating the afore-stated drawbacks.
It is another object of the present invention to provide an improved screening apparatus which includes screen elements of relative great depth without necessitating an inclination of the screen elements.
These objects and others which will become apparent hereinafter are attained in accordance with the present invention by providing the top surface of each screen element with at least one projection which extends in longitudinal direction of the screen element and transversely to the screen area.
The projections may be of any suitable configuration, such as e.g. of rectangular, triangular or serrated cross section, of circular arc shape, nose-like or finger-like configuration, in order to create screen elements with irregular screening surface and without requiring a slanted attachment of the screen elements to the cross bars.
According to another feature of the present invention, at least one wall section of opposing wall sections of two neighboring screen elements, which define the screening slot, extends transversely to the screen area. In this manner, a rapid and undesired expansion of the width of the slot and a deterioration of the sorting quality due to progressing wear of the edges of the screen elements at the inlet side of the screening slot are eliminated or at least greatly diminished.
According to a modification of this embodiment, both opposing wall sections of neighboring screen elements extend transversely to the screen area and at least partly overlap each other so that the screening slot is defined in the overlapping area by two parallel wall sections. This design of the screen elements allows the screening slot to remain constant during wear and tear of the edges at the inlet side into the screening slot, until the overlapping sections of the opposing wall sections are worn off.
BRIEF DESCRIPTION OF THE DRAWING
The above and other objects, features and advantages of the present invention will now be described in more detail with reference to the accompanying drawing in which:
FIG. 1 is a fragmentary schematic partly sectional view of a conventional screening apparatus provided with a plurality of screen elements;
FIGS. 2-5 are fragmentary schematic views of various embodiments of a screening apparatus in accordance with the present invention;
FIGS. 6 and 7 are fragmentary schematic illustrations of two neighboring screen elements, showing in detail the slot area formed between neighboring screen elements; and
FIG. 8 is a fragmentary schematic partly sectional view of a screening apparatus illustrating an exemplified attachment of screen elements to respective cross bars.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Throughout all the Figures, the same or corresponding elements are always indicated by the same reference numerals.
Referring now to the drawing and in particular to FIG. 1, there is shown a fragmentary schematic partly sectional view of a conventional bar screen, generally designated by reference numeral 1 and including a plurality of bar-shaped screen elements 2 which are of essentially triangular cross section and mounted on respective cross bars 4 at an angle a relative to the vertical. By positioning the screen elements 2 at such an inclination, their top surface 8, which faces the fiber suspension to be screened, is thus not levelled so as to improve the screening capacity and the screening quality. For manufacturing reasons, the angle a is limited to a maximum of about 15° so that also the depth h is limited. Even though an increase of the depth h may theoretically be possible by increasing the width of the screen elements 2, such a modification is disadvantageous as it would result in a loss of free surface area and thus would adversely affect the throughput and overall efficiency of the screen. In addition, the inclination of the screen elements 2 causes at the outlet side of the screen elements 2 an asymmetric flow space which leads to pressure losses.
Turning now to FIGS. 2-5, there are shown fragmentary schematic partly sectional views of various embodiments of a screening apparatus in accordance with the present invention, generally designated by reference numeral 10. The screening apparatus 10 includes a plurality of parallel bar-shaped screen elements 12 which are mounted without inclination upon suitable cross bars 14 (only one is shown), with neighboring screen elements 12 defining a screening slot or perforation 16 therebetween. The attachment of the screen elements 12 to the cross bars 14 may be done through welding or through form-fitting connection, as will be described in more detail with reference to FIG. 8.
Each screen element 12 includes a plane or levelled top surface 18 which faces the fiber suspension and is provided with a projection 20 in form of ribs or beads or the like, which extends in longitudinal direction of the screen elements 12, i.e. transversely to the screen area 22. Thus, the screen elements 12 are provided with irregular screening surface, with the depth h being significantly increased, without necessitating an inclination of the screen elements 12 relative to the cross bars 14.
In FIG. 2, the projections 20 are of circular arc shaped configuration and completely cover the top surface 18. In FIG. 3, the projection 20 of the screen elements 12 is formed by a central rib of rectangular cross section while in FIG. 4, the projections 20 are configured in form of a rectangular triangle or in form of a saw tooth and define a slanted surface 40. In FIG. 5, the projections 20 are of triangular cross section, defining a slanted surface 40 and a further slanted surface 42 of sharper inclination. Persons skilled in the art will understand that FIGS. 2-5 show only examples of possible configurations of the projections 20, and other configurations may certainly be conceivable.
In the embodiments according to FIGS. 4 and 5, the screen elements 12 have asymmetric cross section, allowing a versatile arrangement of the screen elements 12. For example, in FIG. 4, the left and central screen elements are mounted to the cross bar 14 with the slanted surface 40 ascending toward the left while the slanted surface 40 of the right screen element 12 ascends toward the right. In FIG. 5, the installation of the screen elements 12 is such that the slanted surface 40 of the left and right screen elements 12 ascends toward the right while the slanted surface 40 of the central screen element 12 ascends toward the left. Thus, when providing the screen elements with asymmetric configuration, as shown in the non-limiting examples of FIGS. 4 and 5, the effective screen area can be selectively designed by differently positioning neighboring screen elements 12 i.e. through turning the screen elements 12 by 180° about the longitudinal axis of the screen element.
Referring now to FIG. 6, there is shown a fragmentary schematic illustration of two neighboring screen elements 12, showing in detail the area of the screening slot 16 between neighboring screen elements 12 for sorting and classifying a fluid flow e.g. a fiber suspension incoming and flowing in direction of arrow F. Each screen element 12 is provided with a slanted top surface 18 which extends at an angle β to the screen area 22, with the center axis 44 of the screen element 12 being oriented at an angle of 90° to the screen area 22. Thus, the screen elements 22 are mounted to the respective cross bars (not shown) without inclination.
Each screen element 12 has one side face which includes a plane vertical wall section 32 extending parallel to the midplane 44 and downwards from the top surface 18 over a certain length and is connected to an inwardly slanted wall section 28 which describes an angle φ 2 with a vertical (i.e. with the prolongation of the wall section 32). At its lower end, the wall section 28 is connected to a side face 30 which extends at an angle φ 1 to the vertical and leads to the top surface 18.
The screening slot 16 is defined between the wall section 32 of one screen element 12 (in FIG. 6, the right screen element) and the upper wall section of side face 30 of a neighboring screen element 12 (in FIG. 6, the left screen element). Defined at the junction of side face 30 and top surface 18 of the left screen element 12 is an upstream edge C which bounds the inlet to slot 16 and extends above a downstream edge B defined at the junction of the wall section 28 and wall section 32 of the right screen element 12. In opposition to corner point C of the left screen element 12 is point A of the right screen element 12, which point A is spaced by a distance h from the screen area 22.
During operation and progressing wear of upstream edge C, the slot 16 expands only at the side of the left screen element 12 because upstream edge C is opposed by a straight or flat wall section 32 which extends transversely to the screen area 22, and thus parallels the midplane 38 of slot 16. Only, when wear of the left screen element has progressed beyond the downstream edge B, i.e. downwards in FIG. 6 will the slot 16 expand at both sides.
By providing the wall section 32 parallel to the midplane 38 and in opposition of the upstream edge C of the neighboring screen element, the expansion or enlargement of the slot 16 can be kept within narrow limits during progressing wear.
Referring now to FIG. 7, there is shown a modification of the screening apparatus for sorting and classifying a fluid flow e.g. a fiber suspension flowing in direction of arrow R, with screen elements 12 being provided with parallel and straight wall sections 24, 26 which extend over a certain length from each end of the top surface 18 in direction toward the cross bars (not shown) and are respectively connected to the converging side faces 28 and 30 which define an angle φ 1 and φ 2 with a vertical upon the screen area 22 and thus with the midplanes 44 and midplane 38. Like in the embodiment of FIG. 6, the top surface 18 is slanted and extends at an angle β relative to the screen area 22, without inclination of the screen elements 12 so that their midplanes 44 are normal to the screen area 22.
Both wall sections 24, 26 extend transversely to the screen area 22 and thus parallel the midplanes 44 of the screen elements 12 and the midplane 38 of the screening slot 16 as formed between neighboring screen elements 12. As shown in FIG. 7, the slot 16 is defined between successive screen elements 12 by the wall sections 26 and 30 of one screen element 12 (left screen element in FIG. 7) and by the wall sections 24 and 28 of the neighboring screen element 12 (right screen element in FIG. 7).
As shown in FIG. 7, the opposing wall sections 26 and 24 slightly overlap each other in direction of the fluid flow through that screening slot as indicated by arrow P, with the right screen element 12 defining a downstream edge C at the junction of the wall section 24 with the wall section 28, and with the left screen element 12 defining a upstream edge A at the junction of the top surface 18 with the wall section 26, whereby the upstream edge A is arranged slightly ahead of the downstream edge C. The distance between the upstream edge A and downstream edge C may be in the range of a few tenth of millimeters to about 1 millimeter, preferably between 0.2 to 0.8 mm, with a distance of 0.5 mm being particularly preferred in flow direction P.
When the upstream edge A starts to wear off, the width of the slot 16 remains constant until the upstream edge A is opposite the downstream edge C. Upon further wear, the overlap of wall sections 26 and 24 is eliminated, and the corner point A shifts below the downstream edge C. Even though, the slot 16 now expands, the expansion is slow and occurs only at the side of the right screen element 12 in correspondence with the inclination of wall section 28 because downstream edge C is opposed by the straight or flat wall section 26 which extends transversely to the screen area 22 and thus parallel to the midplane 38 of slot 16. Only, when wear of the left screen element has progressed beyond the downstream edge B will the slot 16 expand at both sides in accordance with the inclination of wall sections 28 and 30.
Suitably, the height of wall section 26 may be in the range of 0.2-0.8 mm or greater while the height of wall section 24 may be equal or greater than height h.
The parallel arrangement of wall section 26 which represents a wear surface essentially eliminates a rapid expansion of the screening slot through wear.
In the exemplified embodiments of FIGS. 6 and 7, the angle β about 10°-30°, preferably about 15°, the width of the slot 16 is about 0.05 to about 1 mm, the angles β 1 and φ 2 are about 10°-20°, preferably about 15°, the width of each bar-shaped screen element 12 is about 1.5-4 mm and the height of each screen element 12 is about 2.5-7 mm. The height h can be determined by the width b of the screen element 12 and the angle β.
Turning now to FIG. 8, there is shown a fragmentary partly sectional view of a screening apparatus illustrating an exemplified attachment of the screen elements 12 to respective cross bars 14. FIG. 8 illustrates an example of a form-fitting attachment, with each screen element 12 including a profiled base 34, e.g. of dovetail cross section, which engages a complementary indentation 36 in the cross bars 14. Persons skilled in the art will understand that the screen elements may also be attached to the cross bars by other suitable means.
While the invention has been illustrated and described as embodied in a screening apparatus, 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.
What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims:
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A screening apparatus, in particular a bar screen for sorting and classifying fluid flows, especially fiber suspensions includes parallel bar-shaped screen elements mounted on cross bars and defining slotted screening perforations therebetween. At its top surface facing the fluid flow, each screen element is provided with a projection in form of a rib or bead or the like of different cross section to provide an irregular screening surface. The screening slot between neighboring screen elements is defined by at least one wall section which extends parallel to the midplane of the screening slot in order to reduce an expansion of the slot due to wear.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This is a continuation of U.S. patent application Ser. No. 13/663,609, filed Oct. 30, 2012 (issuing as U.S. Pat. No. 8,528,631 on Sep. 10, 2013), which was a continuation of U.S. patent application Ser. No. 13/438,053, filed Apr. 3, 2012, (issuing as U.S. Pat. No. 8,297,348 on Oct. 30, 2012), which was a continuation of U.S. patent application Ser. No. 13/074,327, filed Mar. 29, 2011 (issued as U.S. Pat. No. 8,146,663 on Apr. 3, 2012), which was a continuation of U.S. patent application Ser. No. 12/724,846, filed Mar. 16, 2010, (issued as U.S. Pat. No. 7,913,760 on Mar. 29, 2011), which application was a continuation of U.S. patent application Ser. No. 11/778,956, filed Jul. 17, 2007 (issued as U.S. Pat. No. 7,681,646 on Mar. 23, 2010) which was a continuation-in-part of U.S. patent application Ser. No. 11/751,740, filed May 22, 2007 (issued as U.S. Pat. No. 7,533,720 on May 19, 2009) which was a non-provisional of U.S. Provisional Patent Application Ser. No. 60/829,990, filed Oct. 18, 2006 and U.S. Provisional Patent Application Ser. No. 60/803,055, filed May 24, 2006.
Each of these applications are incorporated herein by reference. Priority of each of these applications is hereby claimed.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable
REFERENCE TO A “MICROFICHE APPENDIX”
Not applicable
BACKGROUND
In top drive rigs, the use of a top drive unit, or top drive power unit is employed to rotate drill pipe, or well string in a well bore. Top drive rigs can include spaced guide rails and a drive frame movable along the guide rails and guiding the top drive power unit. The traveling block supports the drive frame through a hook and swivel, and the driving block is used to lower or raise the drive frame along the guide rails. For rotating the drill or well string, the top drive power unit includes a motor connected by gear means with a rotatable member both of which are supported by the drive frame.
During drilling operations, when it is desired to “trip” the drill pipe or well string into or out of the well bore, the drive frame can be lowered or raised. Additionally, during servicing operations, the drill string can be moved longitudinally into or out of the well bore.
The stem of the swivel communicates with the upper end of the rotatable member of the power unit in a manner well known to those skilled in the art for supplying fluid, such as a drilling fluid or mud, through the top drive unit and into the drill or work string. The swivel allows drilling fluid to pass through and be supplied to the drill or well string connected to the lower end of the rotatable member of the top drive power unit as the drill string is rotated and/or moved up and down.
Top drive rigs also can include elevators are secured to and suspended from the frame, the elevators being employed when it is desired to lower joints of drill string into the well bore, or remove such joints from the well bore.
At various times top drive operations, beyond drilling fluid, require various substances to be pumped downhole, such as cement, chemicals, epoxy resins, or the like. In many cases it is desirable to supply such substances at the same time as the top drive unit is rotating and/or moving the drill or well string up and/or down, but bypassing the top drive's power unit so that the substances do not damage/impair the unit. Additionally, it is desirable to supply such substances without interfering with and/or intermittently stopping longitudinal and/or rotational movement by the top drive unit of the drill or well string.
A need exists for a device facilitating insertion of various substances downhole through the drill or well string, bypassing the top drive unit, while at the same time allowing the top drive unit to rotate and/or move the drill or well string.
One example includes cementing a string of well bore casing. In some casing operations it is considered good practice to rotate the string of casing when it is being cemented in the wellbore. Such rotation is believed to facilitate better cement distribution and spread inside the annular space between the casing's exterior and interior of the well bore. In such operations the top drive unit can be used to both support and continuously rotate/intermittently reciprocate the string of casing while cement is pumped down the string's interior. During this time it is desirable to by-pass the top drive unit to avoid possible damage to any of its portions or components.
The following U.S. patents are incorporated herein by reference: U.S. Pat. Nos. 4,722,389 and 7,007,753.
While certain novel features of this invention shown and described below are pointed out in the annexed claims, the invention is not intended to be limited to the details specified, since a person of ordinary skill in the relevant art will understand that various omissions, modifications, substitutions and changes in the forms and details of the device illustrated and in its operation may be made without departing in any way from the spirit of the present invention. No feature of the invention is critical or essential unless it is expressly stated as being “critical” or “essential.”
BRIEF SUMMARY
The apparatus of the present invention solves the problems confronted in the art in a simple and straightforward manner. One embodiment relates to an assembly having a top drive arrangement for rotating and longitudinally moving a drill or well string. In one embodiment is provided a swivel apparatus, the swivel generally comprising a mandrel and a sleeve with a packing configuration, the swivel being especially useful for top drive rigs.
In one embodiment the sleeve can be rotatably and sealably connected to the mandrel. The swivel can be incorporated into a drill or well string, enabling string sections both above and below the sleeve to be rotated in relation to the sleeve. Additionally, the swivel provides a flow path between the exterior of the sleeve and interior of the mandrel while the drill string is being rotated and/or being moved in a longitudinal direction (up or down). The interior of the mandrel can be fluidly connected to the longitudinal bore of the casing or drill string thereby providing a flow path from the exterior of the sleeve to the interior of the casing/drill string.
In one embodiment is provided a method and apparatus for servicing a well wherein a swivel is connected to a top drive unit for conveying pumpable substances from an external supply through the swivel for discharge into the well string and bypassing the top drive unit.
In another embodiment is provided a method of conducting servicing operations in a well bore, such as cementing, comprising the steps of moving a top drive unit rotationally and/or longitudinally to provide longitudinal movement and/or rotation in the well bore of a well string suspended from the top drive unit, rotating the drill or well string and supplying a pumpable substance to the well bore in which the drill or well string is manipulated by introducing the pumpable substance at a point below the top drive power unit and into the well string.
In other embodiments are provided a swivel placed below the top drive unit can be used to perform jobs such as spotting pills, squeeze work, open formation integrity work, kill jobs, fishing tool operations with high pressure pumps, sub-sea stack testing, rotation of casing during side tracking, and gravel pack or frack jobs. In still other embodiments a top drive swivel can be used in a method of pumping loss circulation material (LCM) into a well to plug/seal areas of downhole fluid loss to the formation and in high speed milling jobs using cutting tools to address down hole obstructions. In other embodiments the top drive swivel can be used with free point indicators and shot string or cord to free stuck pipe where pumpable substances are pumped downhole at the same time the downhole string/pipe/free point indicator is being rotated and/or reciprocated. In still other embodiments the top drive swivel can be used for setting hook wall packers and washing sand.
In still other embodiments the top drive swivel can be used for pumping pumpable substances downhole when repairs/servicing is being done to the top drive unit and rotation of the downhole drill string is being accomplished by the rotary table. Such use for rotation and pumping can prevent sticking/seizing of the drill string downhole. In this application safety valves, such as TIW valves, can be placed above and below the top drive swivel to enable routing of fluid flow and to ensure well control.
The drawings constitute a part of this specification and include exemplary embodiments to the invention, which may be embodied in various forms.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
For a further understanding of the nature, objects, and advantages of the present invention, reference should be had to the following detailed description, read in conjunction with the following drawings, wherein like reference numerals denote like elements and wherein:
FIGS. 1A and 1B are a schematic views showing a top drive rig with one embodiment of a top drive swivel incorporated in the drill string;
FIG. 2 is a perspective view of one embodiment of a top drive swivel;
FIG. 3 is a sectional view of a mandrel which can be incorporated in the swivel of FIG. 2 ;
FIG. 4 is a perspective view of a sleeve, clamp, and torque arm which can be incorporated into the swivel of FIG. 2 ;
FIG. 5 is an exploded view of the sleeve, clamp, and torque arm of FIG. 4 ;
FIG. 6 is a cutaway perspective view of the swivel of FIG. 2 ;
FIGS. 7A and 7B include a sectional view of the swivel of FIG. 2 along with an enlarged sectional view of the packing area;
FIG. 8 is an exploded view of a set of packing which can be incorporated into the swivel of FIG. 2 ;
FIG. 9 is a perspective view of a spacer;
FIG. 10 is a top view of the spacer of FIG. 9 ;
FIG. 11A is a sectional side view of the spacer of FIG. 9 ;
FIG. 11B is an enlarged sectional side view of the spacer of FIG. 9 ;
FIG. 12 is a perspective view of a female backup ring;
FIG. 13 is a top view of the female backup ring of FIG. 12 ;
FIG. 14A is a sectional side view of the female backup ring of FIG. 12 ;
FIG. 14B is an enlarged sectional side view of the female backup ring of FIG. 12 ;
FIG. 15 is a perspective view of a seal ring;
FIG. 16 is a top view of the seal ring of FIG. 15 ;
FIG. 17A is a sectional side view of the seal ring of FIG. 15 ;
FIG. 17B is an enlarged sectional side view of the seal ring of FIG. 15 ;
FIG. 18 is a perspective view of a rope seal;
FIG. 19 is a top view of the rope seal of FIG. 18 ;
FIG. 20A is a sectional side view of the rope seal of FIG. 18 ;
FIG. 20B is an enlarged sectional side view of the rope seal of FIG. 18 ;
FIG. 21 is a perspective view of a seal ring;
FIG. 22 is a top view of the seal ring of FIG. 21 ;
FIG. 23A is a sectional side view of the seal ring of FIG. 21 ;
FIG. 23B is an enlarged sectional side view of the seal ring of FIG. 21 ;
FIG. 24 is a perspective view of a seal ring;
FIG. 25 is a top view of the seal ring of FIG. 24 ;
FIG. 26A is a sectional side view of the seal ring of FIG. 24 ;
FIG. 26B is an enlarged sectional side view of the seal ring of FIG. 24 ;
FIG. 27 is a perspective view of a male backup ring;
FIG. 28 is a top view of the male backup ring of FIG. 27 ;
FIG. 29A is a sectional side view of the male backup ring of FIG. 27 ;
FIG. 29B is an enlarged sectional side view of the male backup ring of FIG. 27 ;
FIGS. 30A and 30B include a sectional view of another embodiment of the swivel of FIG. 2 along with an enlarged sectional view of the packing area;
FIG. 31 is an exploded view of a set of packing which can be incorporated into the swivel of FIG. 30A ;
FIG. 32 is a perspective view of a spacer;
FIG. 33 is a top view of the spacer of FIG. 32 ;
FIG. 34A is a sectional side view of the spacer of FIG. 32 ;
FIG. 34B is an enlarged sectional side view of the spacer of FIG. 32 ;
FIG. 35 is a perspective view of a female backup ring;
FIG. 36 is a top view of the female backup ring of FIG. 35 ;
FIG. 37A is a sectional side view of the female backup ring of FIG. 35 ;
FIG. 37B is an enlarged sectional side view of the female backup ring of FIG. 35 ;
FIG. 38 is a perspective view of a seal ring;
FIG. 39 is a top view of the seal ring of FIG. 38 ;
FIG. 40A is a sectional side view of the seal ring of FIG. 38 ;
FIG. 40B is an enlarged sectional side view of the seal ring of FIG. 38 ;
FIG. 41 is a perspective view of a rope seal;
FIG. 42 is a top view of the rope seal of FIG. 41 ;
FIG. 43A is a sectional side view of the rope seal of FIG. 41 ;
FIG. 43B is an enlarged sectional side view of the rope seal of FIG. 41 ;
FIG. 44 is a perspective view of a seal ring;
FIG. 45 is a top view of the seal ring of FIG. 44 ;
FIG. 46A is a sectional side view of the seal ring of FIG. 44 ;
FIG. 46B is an enlarged sectional side view of the seal ring of FIG. 44 ;
FIG. 47 is a perspective view of a seal ring;
FIG. 48 is a top view of the seal ring of FIG. 47 ;
FIG. 49A is a sectional side view of the seal ring of FIG. 47 ;
FIG. 49B is an enlarged sectional side view of the seal ring of FIG. 47 ;
FIG. 50 is a perspective view of a male backup ring;
FIG. 51 is a top view of the male backup ring of FIG. 50 ;
FIG. 52A is a sectional side view of the male backup ring of FIG. 50 ;
FIG. 52B is an enlarged sectional side view of the male backup ring of FIG. 50 .
DETAILED DESCRIPTION
Detailed descriptions of one or more preferred embodiments are provided herein. It is to be understood, however, that the present invention may be embodied in various forms. Therefore, specific details disclosed herein are not to be interpreted as limiting, but rather as a basis for the claims and as a representative basis for teaching one skilled in the art to employ the present invention in any appropriate system, structure or manner.
FIGS. 1A and 1B are schematic views showing a top drive rig 1 with one embodiment of a top drive swivel 30 incorporated into drill string 20 . FIG. 1A shows a rig 1 having a top drive unit 10 . Rig 1 comprises supports 16 , 17 ; crown block 2 ; traveling block 4 ; and hook 5 . Draw works 11 uses cable 12 to move up and down traveling block 4 , top drive unit 10 , and drill string 20 . Traveling block 4 supports top drive unit 10 . Top drive unit 10 supports drill string 20 .
During drilling operations, top drive unit 10 can be used to rotate drill string 20 which enters wellbore 14 . Top drive unit 10 can ride along guide rails 15 as unit 10 is moved up and down. Guide rails 15 prevent top drive unit 10 itself from rotating as top drive unit 10 rotates drill string 20 . During drilling operations drilling fluid can be supplied downhole through drilling fluid line 8 and gooseneck 6 .
As shown in FIG. 1B , during operations swivel 30 can be connected to rig 1 through clamp 600 and torque arm 630 . Torque are 630 can be pivotally connected to swivel 30 and can resist rotational movement of swivel sleeve 150 relative to rig 1 . Torque arm 630 can be slidably connected to rig 1 to allow a certain amount of longitudinal movement of swivel 30 with drill string 20 .
At various times top drive operations, beyond drilling fluid, require substances to be pumped downhole, such as cement, chemicals, epoxy resins, or the like. In many cases it is desirable to supply such substances at the same time as top drive unit 10 is rotating and/or moving drill or well string 20 up and/or down and bypassing top drive unit 10 so that the substances do not damage/impair top drive unit 10 . Additionally, it is desirable to supply such substances without interfering with and/or intermittently stopping longitudinal and/or rotational movements of drill or well string 20 being moved/rotated by top drive unit 10 . This can be accomplished by using top drive swivel 30 .
Top drive swivel 30 can be installed between top drive unit 10 and drill string 20 . One or more joints of drill pipe 18 can be placed between top drive unit 10 and swivel 30 . Additionally, a valve can be placed between top drive swivel 30 and top drive unit 10 . Pumpable substances can be pumped through hose 31 , swivel 30 , and into the interior of drill string 20 thereby bypassing top drive unit 10 . Top drive swivel 30 is preferably sized to be connected to drill string 20 such as 4½ inch (11.43 centimeter) IF API drill pipe or the size of the drill pipe to which swivel 30 is connected to. However, cross-over subs can also be used between top drive swivel 30 and connections to drill string 20 . Two sizes for swivel 30 will be addressed in this application—a 4½ inch (11.43 centimeter) version and a 6⅝ inch (16.83 centimeter) version.
FIG. 2 is a perspective view of one embodiment of a swivel 30 . Swivel 30 can be comprised of mandrel 40 and sleeve 150 . Sleeve 150 can be rotatably and sealably connected to mandrel 40 . Accordingly, when mandrel 40 is rotated, sleeve 150 can remain stationary to an observer insofar as rotation is concerned. As will be discussed later inlet 200 of sleeve 150 is and remains fluidly connected to a the central longitudinal passage 90 of mandrel 40 . Accordingly, while mandrel 40 is being rotated and/or moved up and down pumpable substances can enter inlet 200 and exit central longitudinal passage 90 at lower end 60 of mandrel 40 .
FIG. 3 is a sectional view of mandrel 40 which can be incorporated in swivel 30 . Mandrel 40 can be comprised of upper end 50 and lower end 60 . Central longitudinal passage 90 can extend from upper end 50 through lower end 60 . Lower end 60 can include a pin connection 80 or any other conventional connection. Upper end 50 can include box connection 70 or any other conventional connection. Mandrel 40 can in effect become a part of drill string 20 . Sleeve 150 can fit over mandrel 40 and become rotatably and sealably connected to mandrel 40 . Mandrel 40 can include shoulder 100 to support sleeve 150 . Mandrel 40 can include one or more radial inlet ports 140 fluidly connecting central longitudinal passage 90 to recessed area 130 . Recessed area 130 preferably forms a circumferential recess along the perimeter of mandrel 40 and between packing support areas 131 , 132 . In such manner recessed area 130 will remain fluidly connected with radial passage 190 and inlet 200 of sleeve 150 (see FIGS. 6 and 7A ).
Mandrel 40 takes substantially all of the structural load from drill string 20 . In one embodiment the overall length of mandrel 40 is preferably 52 and 5/16 inches (132.87 centimeters). Mandrel 40 can be machined from a single continuous piece of heat treated steel bar stock. NC50 is preferably the API Tool Joint Designation for the box connection 70 and pin connection 80 . Such tool joint designation is equivalent to and interchangeable with 4½ inch (11.43 centimeter) IF (Internally Flush), 5 inch (12.7 centimeter) XH (Extra Hole) and 5½ inch (13.97 centimeter) DSL (Double Stream Line) connections. Additionally, it is preferred that the box connection 70 and pin connection 80 meet the requirements of API specifications 7 and 7G for new rotary shouldered tool joint connections having 6⅝ inch (16.83 centimeters) outer diameter and a 2¾ inch (6.99 centimeter) inner diameter. The Strength and Design Formulas of API 7G—Appendix A provides the following load carrying specification for mandrel 40 of top drive swivel 30 : (a) 1,477,000 pounds (6,570 kilo newtons) tensile load at the minimum yield stress; (b) 62,000 foot-pounds (84 kilo newton meters) torsional load at the minimum torsional yield stress; and (c) 37,200 foot-pounds (50.44 kilo newton meters) recommended minimum make up torque. Mandrel 40 can be machined from 4340 heat treated bar stock.
In another embodiment, Mandrel 40 takes substantially all of the structural load from drill string 20 . In one embodiment the overall length of mandrel 40 is preferably 67 and 13/16 inches (172.24 centimeters). Mandrel 40 can be machined from a single continuous piece of heat treated steel bar stock. 6⅝ inch (16.83 centimeters) FH is preferably the API Tool Joint Designation for the box connection 70 and pin connection 80 . Additionally, it is preferred that the box connection 70 and pin connection 80 meet the requirements of API specifications 7 and 7G for new rotary shouldered tool joint connections having 8½ inch (21.59 centimeter) outer diameter and a 4¼ inch (10.8 centimeter) inner diameter. The Strength and Design Formulas of API 7G—Appendix A provides the following load carrying specification for mandrel 40 of top drive swivel 30 : (a) 2,094,661 pounds (9,318 kilo newtons) tensile load at the minimum yield stress; (b) 109,255 foot-pounds (148.1 kilo newton meters) torsion load at the minimum torsional yield stress; and (c) 65,012 foot-pounds (88.14 kilo newton meters) recommended minimum make up torque. Mandrel 40 can be machined from 4340 heat treated bar stock.
To reduce friction between mandrel 40 and packing units 305 , 405 and increase the life expectancy of packing units 305 , 405 , packing support areas 131 , 132 can be coated and/or sprayed welded with a materials of various compositions, such as hard chrome, nickel/chrome or nickel/aluminum (95 percent nickel and 5 percent aluminum) A material which can be used for coating by spray welding is the chrome alloy TAFA 95MX Ultrahard Wire (Armacor M) manufactured by TAFA Technologies, Inc., 146 Pembroke Road, Concord N.H. TAFA 95 MX is an alloy of the following composition: Chromium 30 percent; Boron 6 percent; Manganese 3 percent; Silicon 3 percent; and Iron balance. The TAFA 95 MX can be combined with a chrome steel. Another material which can be used for coating by spray welding is TAFA BONDARC WIRE-75B manufactured by TAFA Technologies, Inc. TAFA BONDARC WIRE-75B is an alloy containing the following elements: Nickel 94 percent; Aluminum 4.6 percent; Titanium 0.6 percent; Iron 0.4 percent; Manganese 0.3 percent; Cobalt 0.2 percent; Molybdenum 0.1 percent; Copper 0.1 percent; and Chromium 0.1 percent. Another material which can be used for coating by spray welding is the nickel chrome alloy TAFALOY NICKEL-CHROME-MOLY WIRE-71T manufactured by TAFA Technologies, Inc. TAFALOY NICKEL-CHROME-MOLY WIRE-71T is an alloy containing the following elements: Nickel 61.2 percent; Chromium 22 percent; Iron 3 percent; Molybdenum 9 percent; Tantalum 3 percent; and Cobalt 1 percent. Various combinations of the above alloys can also be used for the coating/spray welding. Packing support areas 131 , 132 can also be coated by a plating method, such as electroplating. The surface of support areas 131 , 132 can be ground/polished/finished to a desired finish to reduce friction and wear between support areas 131 , 132 and packing units 305 , 415 .
FIG. 4 is a perspective view of a sleeve 150 , clamp 600 , and torque arm 630 which can be incorporated into swivel 30 . FIG. 5 is an exploded view of the components shown in FIG. 4 . FIG. 6 is a cutaway perspective view of swivel 30 . FIG. 7A is a sectional view of swivel 30 taken along the line 7 A- 7 A of FIG. 6 .
FIG. 6 is an overall perspective view (and partial sectional view) of top drive swivel 30 . Sleeve 150 is shown rotatably connected to mandrel 40 . Bearings 145 , 146 allow sleeve 150 to rotate in relation to mandrel 40 . Packing units 305 , 405 sealingly connect sleeve 150 to mandrel 40 . Retaining nut 800 retains sleeve 150 on mandrel 40 . Inlet 200 of sleeve 150 is fluidly connected to central longitudinal passage 90 of mandrel 40 . Accordingly, while mandrel 40 is being rotated and/or moved up and down pumpable substances can enter inlet 200 and exit central longitudinal passage 90 at lower end 60 of mandrel 40 . Recessed area 130 forms a peripheral recess between mandrel 40 and sleeve 150 . The fluid pathway from inlet 200 to outlet at lower end 60 of central longitudinal passage 90 is as follows: entering inlet 200 ; passing through radial passage 190 ; passing through recessed area 130 ; passing through one of the plurality of radial inlet ports 40 ; passing through central longitudinal passage 90 ; and exiting mandrel 40 through central longitudinal passage 90 at lower end 60 and pin connection 80 .
Sleeve 150 can include central longitudinal passage 180 extending from upper end 160 through lower end 170 . Sleeve 150 can also include radial passage 190 and inlet 200 . Inlet 200 can be attached by welding or any other conventional type method of fastening such as a threaded connection. If welded the connection is preferably heat treated to remove residual stresses created by the welding procedure. Lubrication port 210 (not shown) can be included to provide lubrication for interior bearings. Packing ports 220 , 230 can also be included to provide the option of injecting packing material into the packing units 305 , 405 . A protective cover 240 can be placed around packing port 230 to protect packing injector 235 . Optionally, a second protective cover can be placed around packing port 220 . Sleeve 150 can include a groove 691 for insertion of a key 700 . FIG. 7A illustrates how central longitudinal passage 90 is fluidly connected to inlet 200 through radial passage 190 .
Sleeve 150 slides over mandrel 40 . Bearings 145 , 146 rotatably connect sleeve 150 to mandrel 40 . Bearings 145 , 146 are preferably thrust bearings although many conventionally available bearing will adequately function, including conical and ball bearings. Packing units 305 , 405 sealingly connect sleeve 150 to mandrel 40 . Inlet 200 of sleeve 150 is and remains fluidly connected to central longitudinal passage 90 of mandrel 40 . Accordingly, while mandrel 40 is being rotated and/or moved up and down pumpable substances can enter inlet 200 and exit central longitudinal passage 90 at lower end 60 of mandrel 40 . Recessed area 130 forms a peripheral recess between mandrel 40 and sleeve 150 . The fluid pathway from inlet 200 to outlet at lower end 60 of central longitudinal passage 90 is as follows: entering inlet 200 (arrow 201 ); passing through radial passage 190 (arrow 202 ); passing through recessed area 130 (arrow 202 ); passing through one of the plurality of radial inlet ports 140 (arrow 202 ), passing through central longitudinal passage 90 (arrow 203 ); and exiting mandrel 40 via lower end 60 at pin connection 80 (arrows 204 , 205 ).
Sleeve 150 is preferably fabricated from 4140 heat treated round mechanical tubing having the following properties: (120,000 psi (827,400 kilo pascal) minimum tensile strength, 100,000 psi (689,500 kilo pascal) minimum yield strength, and 285/311 Brinell Hardness Range). In one embodiment the external diameter of sleeve 150 is preferably about 11 inches (27.94 centimeters). Sleeve 150 preferably resists high internal pressures of fluid passing through inlet 200 . Preferably top drive swivel 30 with sleeve 150 will withstand a hydrostatic pressure test of 12,500 psi (86,200 kilo pascal). At this pressure the stress induced in sleeve 150 is preferably only about 24.8 percent of its material's yield strength. At a preferable working pressure of 7,500 psi (51,700 kilo pascal), there is preferably a 6.7:1 structural safety factor for sleeve 150 .
To minimize flow restrictions through top drive swivel 30 , large open areas 140 are preferred. Preferably each area of interest throughout top drive swivel 30 is larger than the inlet service port area 200 . Inlet 200 is preferably 3 inches having a flow area of 4.19 square inches (27.03 square centimeters). In one embodiment the flow area of the annular space between sleeve 150 and mandrel 40 is preferably 20.81 square inches (134.22 square centimeters). The flow area through the plurality of radial inlet ports 140 is preferably 7.36 square inches (47.47 square centimeters). The flow area through central longitudinal bore 90 is preferably 5.94 square inches 38.31 square centimeters).
Retainer nut 800 can be used to maintain sleeve 150 on mandrel 40 . Retainer nut 800 can threadably engage mandrel 40 at threaded area 801 . Set screw 890 can be used to lock in place retainer nut 800 and prevent nut 800 from loosening during operation. A set screw 890 (not shown for clarity) can threadably engages retainer nut 800 through bore 900 (not shown for clarity) and sets in one of a plurality of receiving portions 910 formed in mandrel 40 . Retaining nut 800 can also include grease injection fitting 880 for lubricating bearing 145 . A wiper ring 271 (not shown for clarity) can be set in area 270 protects against dirt and other items from entering between the sleeve 150 and mandrel 40 . A grease ring 291 (not shown for clarity) can be set in area 290 for holding lubricant for bearing 145 .
Bearing 146 can be lubricated through a grease injection fitting 211 and lubrication port 210 (not shown for clarity).
FIGS. 4 and 5 best show clamp 600 which can be incorporated into top drive swivel 30 . FIG. 5 is an exploded view of clamp 600 . Clamp 600 can comprises first portion 610 , second portion 620 , and third portion 625 . First, second, and third portions 610 , 620 , 625 can be removably attached by plurality of fasteners 670 , 680 . Key 700 can be inserted in keyway 690 of clamp 600 . A corresponding keyway 691 is included in sleeve 150 of top drive swivel 30 . Keyways 690 , 691 and key 700 prevent clamp 600 from rotating relative to sleeve 150 . A second key 720 can be installed in keyways 710 , 711 . Third, fourth, and additional keys/keyways can be used as desired.
Shackles can be attached to clamp 600 to facilitate handing top drive swivel 30 when clamp 600 is attached. Torque arm 630 can be pivotally attached to clamp 600 and allow attachment of clamp 600 (and sleeve 150 ) to a stationary part of top drive rig 1 preventing sleeve 150 from rotating while drill string 20 is being rotated by top drive 10 (and top drive swivel 30 is installed in drill string 20 ). Torque arm 630 can be provided with holes for attaching restraining shackles. Restrained torque arm 630 prevents sleeve 150 from rotating while mandrel 40 is being spun. Otherwise, frictional forces between packing units 305 , 405 and packing support areas 131 , 135 of rotating mandrel 40 would tend to also rotate sleeve 150 . Clamp 600 is preferably fabricated from 4140 heat treated steel being machined to fit around sleeve 150 .
FIG. 8 shows a blown up schematic view of packing unit 305 . FIG. 7B shows a sectional view through packing area 305 . Packing unit 305 can comprise female packing end 330 ; packing ring 340 , packing lubrication ring 350 , packing ring 360 , packing ring 370 , and packing end 380 . Packing unit 305 sealing connects mandrel 40 and sleeve 150 . Packing unit 305 can be encased by packing retainer nut 310 , spacer 320 , and shoulder 156 of protruding section 155 . Packing retainer nut 310 can be a ring which threadably engages sleeve 150 at threaded area 316 . Packing retainer nut 310 and shoulder 156 squeeze packing unit 305 to obtain a good seal between mandrel 40 and sleeve 150 . Set screw 315 can be used to lock packing retainer nut 310 in place and prevent retainer nut 310 from loosening during operation. Set screw 315 can be threaded into bore 314 and lock into receiving area 317 on sleeve 150 . Packing unit 405 (shown in FIG. 7A ) can be constructed substantially similar to packing unit 305 . The materials for packing unit 305 and packing unit 405 can be similar.
Spacer 320 can comprise, first end 322 , second end 324 , internal surface 326 , and external surface 328 . Spacer 320 can be sized based on the amount of squeezed to be applied to packing unit 305 when packing retainer nut 310 is tightened. It is preferably fabricated or machined from bronze.
Packing end 330 is preferably a female packing end comprised of a bearing grade peak or stiffened bronze material. Female packing ring or end 330 can comprise tip 332 with concave portion 331 . Concave portion 331 can have an angle of about 130 degrees at its center. Tip 332 can include side 333 , recessed area 334 , peripheral groove 337 and inner diameter 335 . Recessed area 334 and inner diameter 335 can be configured to minimize contact of female packing ring or end 330 with mandrel 40 . Instead, contact will be made between packing ring 340 and mandrel 40 . It is believed that minimizing contact between female packing ring or end 330 and mandrel 40 will reduce heat buildup from friction and extend the life of the packing unit. It is also believed that packing ring 340 performs the great majority of sealing against high pressure fluids (such as pressures above about 3,000 or about 4,000 psi (20,700 kilo pascals or 27,600 kilo pascals)). It is also believed that packing rings 370 and/or 360 perform the majority of sealing against lower pressure fluids. Female packing ring 330 can include a plurality of radial ports 336 fluidly connecting peripheral groove 337 with interior groove 338 to allow packing injected to evenly distribute around ring and into the actual sealing rings.
Packing ring 340 can comprise tip 342 , base 344 , internal surface 346 , and external surface 348 . Tip 342 can have an angle of about 120 degrees to have an non-interference fit with tip 332 of female packing end 330 which is at about 130 degrees Base 344 can have an angle of about 120 degrees. Packing ring 340 is preferably a “Vee” packing ring—comprised of bronze filled teflon such as that supplied by CDI material number 714. Tip 342 of packing ring 340 is made at about 120 degrees (which is blunter than the conventional 90 degree tips) in an attempt to limit the braking effect (e.g., caused by expansion of recessed area 334 of the female packing ring or end 330 which would cause side 333 of female packing ring to contact mandrel 40 ) on mandrel 40 when longitudinal force is applied through the packing. Base 344 being at about 120 degrees is believed to assist in causing packing ring 340 to bear against mandrel 40 , and not side 333 of female packing ring 330 .
Packing lubrication ring 350 , preferably includes at least one rope seal such as a Garlock ½ inch (or 7/16 inch or ⅜ inch) (1.27 centimeters, or 1.11 centimeters, or 0.95 centimeters) section 8913 Rope Seal. Rope seals have surprisingly been found to extend the life of other seals in the packing unit. This is thought to be by secretion of lubricants, such as graphite, during use over time. Although shown in a “Vee” type shape, rope seals typically have a square cross section and form to the shape of the area to which they are confined. Here, lubrication ring 350 is shown after be shaped by packing rings 340 and 360 .
Packing ring 360 can comprise tip 362 , base 364 , internal surface 366 , and external surface 368 . Tip 362 can have an angle of about 90 degrees. Base 364 can have an angle of about 120 degrees. 90 degrees for the tip and 120 degrees for the base are conventional angles. The larger angle for the base allows thermal expansion of the tip in the base. Packing ring 360 is preferably a “Vee” packing ring—comprised of hard rubber such as that supplied by CDI material number 850 or viton such as that supplied by CDI material number 951.
Packing rings 360 , 370 can have substantially the same geometric construction. Packing ring 370 can comprise tip 372 , base 374 , internal surface 376 , and external surface 378 . Tip 372 can have an angle of about 90 degrees. Base 374 can have an angle of about 120 degrees. 90 degrees for the tip and 120 degrees for the base are conventional angles. The larger angle for the base allows thermal expansion of the tip in the base. Packing ring 370 is preferably a “Vee” packing ring—comprised of teflon such as that supplied by CDI material number 711.
In an alternative embodiment both packing rings 360 and 370 are“Vee” packing rings—comprised of teflon such as that supplied by CDI material number 711.
In another alternative embodiment packing ring 370 can be a “Vee” packing ring—comprised of hard rubber such as that supplied by CDI material number 850 or viton such as that supplied by CDI material number 951; and Packing ring 360 can be a “Vee” packing ring—comprised of teflon such as that supplied by CDI material number 711.
Male packing end or ring 380 can comprise tip 382 , base 384 , internal surface 386 , and external surface 388 . Tip 382 can have an angle of about 90 degrees. Packing end 380 is preferably an aluminum bronze male packing ring.
Various alternative materials for packing rings can be used such as standard chevron packing rings of standard packing materials.
Using the above packing configuration it has been surprisingly found that packing life in a displacement job at high pressure can be extended from about 45 minutes to about 10 hours, at rotation speeds of about 30, about 40, about 50, and about 60 revolutions per minute.
In installing packing units 305 , 405 , it has been found that the packing units should first be compressed in a longitudinal direction between sleeve 150 and a dummy cylinder (the dummy cylinder serving as mandrel 40 ) before sleeve 150 is installed on mandrel 40 . This is because a certain amount of longitudinal compression of packing units 305 , 405 will occur when fluid pressure is first exerted on these packing units. This longitudinal compression will be taken up by the respective packing retainer nuts 310 . However, using a dummy cylinder allows the individual packing retainer nuts 310 to cause pre-fluid pressure longitudinal compression on packing units 305 , 405 , but still allow the seals to maintain an internal diameter consistent with the external diameter of mandrel 40 . Such a procedure can avoid the requirement of resetting the individual packing retainer nuts 310 after fluid pressure is applied to the packing units causing longitudinal compression.
Female packing ring or end 330 can include a packing injection option. Injection fitting 225 can be used to inject additional packing material such as teflon into packing unit 305 . Head 226 for injection fitting 225 can be removed and packing material can then be inserted into fitting 225 . Head 226 can then be screwed back into injection fitting 225 which would push packing material through fitting 225 and into packing port 220 . The material would then be pushed into packing ring or end 330 . Packing ring or end 330 can comprise a plurality of radial ports 336 , outer peripheral groove 337 , and inner peripheral groove 338 . The material would proceed through outer groove 337 , through the plurality of radial ports 336 , and through inner peripheral groove 338 causing a sealing effect. The interaction between injection fitting 235 and packing unit 405 can be substantially similar to the interaction between injection fitting 225 and packing unit 305 . A conventionally available material which can be used for packing injection fittings 225 , 235 is DESCO™ 625 Pak part number 6242-12 in the form of a 1 inch by ⅜ inch (2.54 centimeter by 0.95 centimeter) stick and distributed by Chemola Division of South Coast Products, Inc., Houston, Tex.
Injection fittings 225 , 235 have a dual purpose: (a) provide an operator a visual indication whether there has been any leakage past either packing units 305 , 405 and (b) allow the operator to easily inject additional packing material and stop seal leakage without removing top drive swivel 30 from drill string 20 .
FIGS. 30A through 50 show an alternative packing arrangement for packing units 305 , 405 . In this alternative arrangement spacer 420 can include a plurality of radial ports for injecting packing filler material.
FIG. 31 shows a blown up schematic view of packing unit 405 . FIG. 30B shows a sectional view through packing unit 405 . Packing unit 405 can comprise female packing end 430 ; packing ring 440 , packing lubrication ring 450 , packing ring 460 , packing ring 470 , and packing end 480 . Packing unit 405 sealing connects mandrel 40 and sleeve 150 . Packing unit 405 can be encased by packing retainer nut 310 , spacer 420 , and shoulder 156 of protruding section 155 . Packing retainer nut 310 can be a ring which threadably engages sleeve 150 at threaded area 316 . Packing retainer nut 310 and shoulder 156 squeeze packing unit 405 to obtain a good seal between mandrel 40 and sleeve 150 . Set screw 315 can be used to lock packing retainer nut 310 in place and prevent retainer nut 310 from loosening during operation. Set screw 315 can be threaded into bore 314 and lock into receiving area 317 on sleeve 150 . An upper packing unit can be constructed substantially similar to packing unit 405 . The materials for packing unit 405 and upper packing unit can be similar.
Spacer 420 can comprise, first end 421 , second end 422 , internal surface 423 , and external surface 424 . Spacer 420 can be sized based on the amount of squeezed to be applied to packing unit 405 when packing retainer nut 310 is tightened. It is preferably fabricated or machined from bronze.
Packing end 430 is preferably a female packing end comprised of a bearing grade peak or stiffened bronze material. Female packing ring or end 430 can comprise tip 432 with concave portion 431 . Concave portion 431 can have an angle of about 130 degrees at its center. Tip 442 can include side 433 , recessed area 44 , peripheral groove 47 and inner diameter 445 . Recessed area 434 and inner diameter 435 can be configured to minimize contact of female packing ring or end 430 with mandrel 40 . Instead, contact will be made between packing ring 440 and mandrel 40 . It is believed that minimizing contact between female packing ring or end 430 and mandrel 40 will reduce heat buildup from friction and extend the life of the packing unit. It is also believed that packing ring 440 performs the great majority of sealing against high pressure fluids (such as pressures above about 3,000 or about 4,000 psi)(20,700 kilo pascals or 27,600 kilo pascals). It is also believed that packing rings 470 and/or 460 perform the majority of sealing against lower pressure fluids.
Packing ring 440 can comprise tip 442 , base 444 , internal surface 446 , and external surface 448 . Tip 442 can have an angle of about 120 degrees to have an non-interference fit with tip 432 of female packing end 430 which is at about 130 degrees Base 444 can have an angle of about 120 degrees. Packing ring 440 is preferably a “Vee” packing ring—comprised of bronze filled teflon such as that supplied by CDI material number 714. Tip 442 of packing ring 440 is made at about 120 degrees (which is blunter than the conventional 90 degree tips) in an attempt to limit the braking effect (e.g., caused by expansion of recessed area 434 of the female packing ring or end 430 which would cause side 433 of female packing ring to contact mandrel 40 ) on mandrel 40 when longitudinal force is applied through the packing. Base 444 being at about 120 degrees is believed to assist in causing packing ring 440 to bear against mandrel 40 , and not side 433 of female packing ring 430 .
Packing lubrication ring 450 , preferably includes at least one rope seal such as a Garlock ½ inch (or 7/16 inch or ⅜ inch) (1.27 centimeters, or 1.11 centimeters, or 0.95 centimeters) section 8913 Rope Seal. Rope seals have surprisingly been found to extend the life of other seals in the packing unit. This is thought to be by secretion of lubricants, such as graphite, during use over time. Although shown in a “Vee” type shape, rope seals typically have a square cross section and form to the shape of the area to which they are confined. Here, lubrication ring 450 is shown after being shaped by packing rings 440 and 460 .
Packing ring 460 can comprise tip 462 , base 464 , internal surface 466 , and external surface 468 . Tip 462 can have an angle of about 90 degrees. Base 464 can have an angle of about 120 degrees. 90 degrees for the tip and 120 degrees for the base are conventional angles. The larger angle for the base allows thermal expansion of the tip in the base. Packing ring 460 is preferably a “Vee” packing ring—comprised of hard rubber such as that supplied by CDI material number 850 or viton such as that supplied by CDI material number 951.
Packing rings 460 , 470 can have substantially the same geometric construction. Packing ring 470 can comprise tip 472 , base 474 , internal surface 476 , and external surface 478 . Tip 472 can have an angle of about 90 degrees. Base 474 can have an angle of about 120 degrees. 90 degrees for the tip and 120 degrees for the base are conventional angles. The larger angle for the base allows thermal expansion of the tip in the base. Packing ring 470 is preferably a “Vee” packing ring—comprised of teflon such as that supplied by CDI material number 711.
In an alternative embodiment both packing rings 460 and 470 are“Vee” packing rings—comprised of teflon such as that supplied by CDI material number 711.
In another alternative embodiment packing ring 470 can be a “Vee” packing ring—comprised of hard rubber such as that supplied by CDI material number 850 or viton such as that supplied by CDI material number 951; and Packing ring 460 can be a “Vee” packing ring—comprised of teflon such as that supplied by CDI material number 711.
Male packing end or ring 480 can comprise tip 482 , base 484 , internal surface 486 , and external surface 488 . Tip 482 can have an angle of about 90 degrees. Packing end 480 is preferably an aluminum bronze male packing ring.
Various alternative materials for packing rings can be used such as standard chevron packing rings of standard packing materials.
The following is a list of reference numerals:
LIST FOR REFERENCE NUMERALS
(Part No.)
(Description)
Reference Numeral
Description
1
rig
2
crown block
3
cable means
4
travelling block
5
hook
6
gooseneck
7
swivel
8
drilling fluid line
10
top drive unit
11
draw works
12
cable
13
rotary table
14
well bore
15
guide rail
16
support
17
support
18
drill pipe
19
drill string
20
drill string or work string
30
swivel
31
hose
40
swivel mandrel
50
upper end
60
lower end
70
box connection
80
pin connection
90
central longitudinal passage
100
shoulder
110
interior surface
120
external surface (mandrel)
130
recessed area
131
packing support area
132
packing support area
140
radial inlet ports (a plurality)
145
bearing
146
bearing
150
swivel sleeve
155
protruding section
156
shoulder
157
shoulder
158
packing support area
159
packing support area
160
upper end
170
lower end
180
central longitudinal passage
190
radial passage
200
inlet
201
arrow
202
arrow
203
arrow
204
arrow
205
arrow
210
lubrication port
211
grease injection fitting
220
packing port
225
injection fitting
226
head
230
packing port
235
injection fitting
240
cover
250
upper shoulder
260
lower shoulder
270
area for wiper ring
271
wiper ring (preferably Parker
part number 959-65)
280
area for wiper ring
281
wiper ring (preferably Parker
part number 959-65)
290
area for grease ring
291
grease ring (preferably Parker part
number 2501000 Standard Polypak)
300
area for grease ring
301
grease ring (preferably Parker part
number 2501000 Standard Polypak)
305
packing unit
310
packing retainer nut
314
bore for set screw
315
set screw for packing retainer nut
316
threaded area
317
set screw for receiving area
320
spacer
322
first end
324
second end
326
internal surface
328
external surface
330
female packing end and packing
injection ring
331
concave portion
332
tip
333
side
334
recessed area
335
inner diameter
336
radial port
337
peripheral groove
338
interior groove
340
packing ring
342
tip
344
base
346
internal surface
348
external surface
350
packing ring
360
packing ring
362
tip
364
base
366
internal surface
368
external surface
370
packing ring
372
tip
374
base
376
internal surface
378
external surface
380
packing end
382
tip
384
base
386
internal surface
388
external surface
405
packing unit
410
packing retainer nut
414
bore for set screw
415
set screw for packing retainer nut
416
threaded area
417
set screw for receiving area
420
spacer and packing injection ring
421
first end
422
second end
423
internal surface
424
external surface
437
radial port
438
peripheral groove
439
interior groove
430
female packing end
431
concave portion
432
tip
433
side
434
recessed area
435
inner diameter
436
external diameter
440
packing ring
442
tip
444
base
446
internal surface
448
external surface
450
packing ring
460
packing ring
462
tip
464
base
466
internal surface
468
external surface
470
packing ring
472
tip
474
base
476
internal surface
478
external surface
480
packing end
482
tip
484
base
486
internal surface
488
external surface
600
clamp
605
groove
610
first portion
620
second portion
625
third portion
630
torque arm
650
shackle
660
shackle
670
plurality of fasteners
680
plurality of fasteners
690
keyway
691
keyway
700
key
710
keyway
711
keyway
720
key
All measurements disclosed herein are at standard temperature and pressure, at sea level on Earth, unless indicated otherwise. All materials used or intended to be used in a human being are biocompatible, unless indicated otherwise.
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 methods differing from the type described above. 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 set forth in the appended claims. The foregoing embodiments are presented by way of example only; the scope of the present invention is to be limited only by the following claims.
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For use with a top drive power unit supported for connection with a well string in a well bore to selectively impart longitudinal and/or rotational movement to the well string, a feeder for supplying a pumpable substance such as cement and the like from an external supply source to the interior of the well string in the well bore without first discharging it through the top drive power unit including a mandrel extending through a sleeve which is sealably and rotatably supported thereon for relative rotation between the sleeve and mandrel. The mandrel and sleeve have flow passages for communicating the pumpable substance from an external source to discharge through the sleeve and mandrel and into the interior of the well string below the top drive power unit. The unit can include a packing injection system and novel seal configuration.
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BACKGROUND OF THE INVENTION
This invention relates to a builder machanism for textile machines. More particularly, it relates to an improved, extremely compact builder mechanism of the electromechanical type which controls the extents of reciprocatory vertical movements of machine elements which layer fibrous strands onto cops, such as the movements of ring rails in spinning machines or the movements of roving spindles in speed frames. The present builder includes an electromechanical control means concentric to a builder shaft which is interconnected with a reversible drive means for the aforesaid machine elements, the present control means including a differential gearing assembly which effects with time of machine operation incremental angular advancements of switch components interconnected with the drive means to effect reversals by means of pick gear and pick gear pawl members also disposed concentric to the builder shaft's axis. By such concentric construction, the present builder is extremely compact and imparts the advantage of being installed or removed from the builder shaft as a unit for maintenance in extremely short time intervals with concomitant economic benefits of reducing unproductive intervals of machine downtime for such maintenance.
In contast, mechanical builder mechanisms conventionally employed effect control over the change in reversals of reciprocatory elements of most ring spinning or roving machines through the use of a builder cam interconnected by mechanical elements to the builder shaft to effect required stepped advancements of the points of reciprocatory reversals in vertical movement of the strand layering elements. Typical of such prior art constructions are the builders shown, for example, in U.S. Pats. Nos. 678,408; 2,982,487; 3,072,350; 3,325,109; and 3,369,764.
Attempts have been made to move away from the all mechanical type builder mechanisms in order to provide certain advantages. Among these are the electromechanical builder mechanisms which possess the potential to provide a more instantaneous control response in the patterning of reciprocatory stroke reversals than the all mechanical systems, thus to hold forth the promise of providing a more precise patterning of strand layers on a cop than mechanical mechanisms which are limited in this regard because of time lags induced in the transmission of movement by multiple mechanical linkages. Typical ones of proposed electromechanical builders are disclosed by U.S. Pats. Nos. 3,097,475; 3,367,588; 3,461,747; 3,477,654; 3,484,050; and 3,547,363.
In such prior art mechanical and electromechanical builder mechanisms it is to be readily noted that their components are fixed to and distributed among a plurality of shafts or other supporting elements which are spaced apart or otherwise physically disassociated from one another. Such arrangements can provide disadvantages and problems in that various components may be located where they may, for example, be exposed to unauthorized tampering and/or to damage, as from accidental impacts, lint accumulations, and the like. Additionally, such arrangements may impede an operator's ready access for adjustment of certain components which normally must be adjusted when it is desired to change the configuration or "build" of the strand packages to be produced. Further and perhaps most importantly, such arrangements tend to provide extended machine downtimes for maintenance work which would be required, such as to remedy malfunctions of the builder mechanism especially when occurring for some unapparent and not immediately ascertainable reason. Thus, with prior art arrangements the textile machine may remain idle while each of the various control components of the builder mechanism is individually removed and examined to locate the source of malfunction, and until the malfunctioning component is identified and replaced. Such idle intervals may be of several hours to several days in duration because of the difficulties involved in removing the separated components, their examination and replacement. This has imposed substantial economic disadvantages by removing the machine from production for these prolonged intervals. A yet further economic disadvantage present in prior art constructions resides in the requirement for substantial space to house these builder mechanisms with their dispersed components. With the ever increasing rise in costs of already expensive floor space in commercial textile mills, the economic disadvantages inherent in such prior art mechanisms are manifest.
OBJECTS OF THE INVENTION
Thus it is an object of the invention to provide a very compact builder mechanism for textile machines, wherein the control adjustment components of which are readily accessible and the builder mechanism as an entity is quickly removable and replaceable as a unit.
Other desirable objects of the invention will become apparent through the explanations which follow.
SUMMARY OF THE INVENTION
The present invention provides, in association with an electromechanical builder mechanism of the type having reversing-switch components mounted in adjacent relationship to an oscillatorily-movable builder shaft for movement along arcuate paths of travel concentric with such shaft, of pick-mechanism components which also are all mounted in adjacent relationship to such shaft and which are intermittently driven from said shaft along paths of travel concentric therewith at desired intermittent times to advance the angular positions of certain of the switching components about the shaft axis and thereby cause desired advancement of the reciprocatory strokes of the ring rails of the spinning machine with which the builder mechanism is associated. The aforesaid pick mechanism includes a differential gearing assembly and a pick gear each disposed in concentric relationship to the axis of the oscillatorily-movable shaft, and further includes means carried by and movable in unison with such shaft about its axis for at desired times imparting a driving input to the differential gearing assembly through the pick gear. In a preferred embodiment of the invention the aforesaid means for imparting a driving input to the pick gear comprises pawl means which may be and preferably is carried by an arm affixed to the oscillatorily-movable shaft and supporting other switching components for oscillatory movement in unison with said shaft about its axis. Such arm may and preferably does also comprise part of means for effecting return movement of certain control components of the builder mechanism about the axis of the builder shaft during wind-down of the ring rails of the spinning machine following each package-forming operation, which return movement is facilitated by then-transpiring free rotation of a normally-restrained control gear of the differential gearing assembly.
By adjustment of the positions of appropriate components of the builder mechanism about the axis of the builder shaft, which adjustment can be readily effected, the length of the reciprocatory strokes of the spinning-machine ring rails, and/or the magnitude of the advancement or "gain" of such strokes may be varied as desired.
DESCRIPTION OF THE DRAWINGS
Still other objects and benefits of the invention will be in part apparent and in part pointed out specifically hereinafter in the following description of an illustrative embodiment thereof, which should be read in conjunction with the accompanying drawings in which:
FIG. 1 is a schematic end-elevational view of the ring rails of a textile spinning machine and of the means, including a builder mechanism in accordance with the present invention, for imparting vertical movement to such ring rails;
FIG. 2 is an enlarged front elevational view, taken approximately in the direction of the arrows 2--2 of FIG. 1, of a cover plate for and some associated control components of the builder mechanism control means;
FIG. 3 is a further enlarged front elevational view of the builder mechanism control means, showing those control components thereof behind the cover plate illustrated in FIG. 2;
FIG. 4 is a composite side elevational view, taken approximately in the direction of the arrows 4--4 of FIGS. 2 and 3 and enlarged with respect to FIG. 2, of builder mechanism control components shown in FIGS. 2 and 3.
FIG. 5 is a view taken approximately along the line 5--5 through the builder mechanism control components of FIG. 3 and showing the same partially in vertical section and partially in side elevation; and
FIG. 6 is a schematic representative of a filling-wind yarn-package that is produceable by the builder mechanism.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The textile spinning machine 10 fragmentarily and schematically shown in FIG. 1 includes vertically movable ring rails 12,12' and a builder mechanism 14 having a center shaft 16 extending through a gear box 18 and driveable in opposite directions by reversible drive means 20 controlled by control means 22 disposed adjacent one end portion, illustratively the right end portion as viewed in FIG. 1, of shaft 16. A drum 24 upon the opposite end portion of shaft 16 (the left end portion, as viewed in FIG. 1) is connected by a chain 26, or other elongate flexible member, to another drum 28 mounted thereabove upon a windlass shaft 30 which in turn is conventionally connected to ring rails 12,12' as by means of drums 32,32' and associated tapes 34,34'. Windlass shaft 30 is also connected as by a drum 36 and associated chain 38 or the like to suitable biasing means (not shown) which partially counter-balances the weight of ring rails 12,12'. The foregoing innerconnection therebetween causes ring rails 12,12' to move either upwardly or downwardly in response to rotation of builder shaft 16, and illustratively is such that the ring rails move upwardly when shaft 16 is rotated in a counterclockwise direction, as viewed from the direction of the arrows 2--2 of FIG. 1, and are moved downwardly when shaft 16 is rotated in a clockwise direction.
For the production by machine 10 of filling-wind packages, such as the one 39 illustrated in FIG. 6, builder shaft 16 should be driven by drive means 30 through oscillatory strokes which are progressively advanced in a counterclockwise direction about the shaft axis, thereby causing ring rails 12,12' to be moved through vertical reciprocatory strokes which progressively advance upwardly. To "wind-down" rails 12,12' at the completion of a package builder operation, builder shaft 16 should be rotated in a clockwise direction by drive means 20. The aforesaid and other desired results are produced by the builder control means 22 associated with the right end portion of shaft 16, as viewed in FIG. 1, and more specifically illustrated in FIGS. 2-5, to which reference is now made.
Control means 22 includes switching components illustratively in the form of a plurality of encapsulated and magnetically-actuable reed switches 40,42,44,46 and 48, and a pair of switch-actuating magnet elements 50,52. Magnets 50,52 are respectively affixed to opposite ends of a stud 54 (see particularly FIG. 4) carried by and extending through the outer end portion of an arm member 56 fixedly but adjustably secured adjacent its inner end, as by a set screw 58 (FIG. 5), to the terminal end-portion of shaft 16. Rotation of shaft 16 causes simultaneous angular movement of magnets 50,52 along arcuate paths of travel concentric with and radially spaced from the shaft axis. Plate members 43, 60 (see particularly FIG. 3), the latter having an arcuate slot 62 therein, are mounted, in a manner described more fully hereinafter, for angular movement about shaft 16. Reed switches 40, 42 are respectively carried by plates 43, 60 for angular movement in unison along an arcuate path of travel concentric with the axis of shaft 16 and in laterally-spaced adjacent relationship to the arcuate path of travel of magnet 50 upon the rear end of the stud 54 carried by arm 56. Switches 40, 42 are each effective, when actuated during regular package-building operation of machine 10 by proximity of magnet 50 thereto, to effect reversal of drive means 20 and thus reversal of the directions of movement of shaft 16 and ring rails 12, 12'. The angular spacing between switches 40, 42 therefore determines the length of the oscillatory or reciprocatory strokes of movement of shaft 16 and ring rails 12, 12' during normal package-building operation of machine 10, and angular advancement of the positions of such switches 40, 42 about the axis of shaft 16 causes corresponding advancement of strokes of movement of shaft 16 and ring rails 12, 12'.
The remaining reed switches 44, 46 and 48 are all carried by a cover plate 64 (FIGS. 2 and 4) pivotally or otherwise removably mounted in any suitable manner adjacent the free end of shaft 16. Plate 64 has arcuate slots 65 therein which mount such switches for angular adjustive movement along arcuate paths of travel concentric with the projected axis of shaft 16 and in laterally-adjacent spaced relationship to the angular path of travel of the magnet 52 upon the forward end of the stud 54 carried by arm 56. Actuation of switch 44 by magnet 52 at the completion of each package-building operation then causes drive means 20 to rotate shaft 16 in a clockwise direction, thus "winding down" ring rails 12, 12'. Actuation of switch 48 by magnet 52 terminates the foregoing rotation of shaft 16 by drive means 20 and its angular position is therefore determinative of the lowered position to which rails 12, 12' are "wound down". For a brief period of time at the commencement of a package-building operation by a spinning machine, the ring rails are normally caused to undergo a "jogging motion" movement through reciprocatory strokes of preselected desired lenth. Switch 42 establishes the lower limit of such "jogging motion" strokes, as well as the lower limits of the normal package-building strokes of the ring rail. However, the upper limit of the "jogging motion" strokes is established not by switch 40, which is disabled during the jogging operaton, but rather by switch 46, which is actuable by magnet 52. The length of the "jogging motion" strokes may therefore be adjusted as desired by varying the position of switch 46 longitudinally of its associated slot 65. Upon completion of the jogging operation, control of drive means 20 is again assumed by switches 40, 42 and magnet 50.
The above-described features of builder mechanism 14 are generally similar to ones disclosed in prior U.S. Pat. Nos.
3,811,628 and/or 3,861,130, to which reference may be made for a more detailed explanation if desired.
In accordance with one aspect of the present invention, to be now described, improved means are provided in closely adjacent concentric relationship to shaft 16 for effecting periodic advancement of switches 40,42 in a counterclockwise direction about the axis of such shaft during package-building operation of machine 10, and for effecting clockwise return movement of such switches about the shaft axis during and in response to the "winding-down" clockwise rotation of shaft 16 at the completion of each package-building operation.
As shown in FIGS. 3-5, such means includes a pick gear 66, a pick-gear shroud member 68, a pick-gear pawl 70 (shown only in FIGS. 3 and 4), and a differential gearing assembly 72 having ring gears 74, 76 and planetary gearing including a planet carrier 80 mounting at least one planetary gear 82. All of the aforesaid components are disposed in concentric relationship to that portion of builder center shaft 16 intermediate gear box 18 and arm 56, for movement at desired times along arcuate paths of travel concentric with the axis of such shaft. As is best shown in FIG. 5, the sleeve-like hub portion of planet carrier 80 is journaled upon the aforesaid portion of shaft 16 and extends along substantially its entire length between gear box 18 and arm 56. Releasable retaining rings 81 encircle the hub portion of planet carrier 30, adjacent its opposite end portions, and restrain axial movement of the gears 74, 76, 66 which are supported upon the hub portion of planet carrier 80. Ring gears 74, 76 are independently journaled upon the hub of planet carrier 80, for rotation relative such hub in spaced adjacent relationship to each other and with their internal gear teeth in innermeshing relationship with planet gear 82. Pick gear 66 is keyed or otherwise fixedly secured to that end portion of the hub of planet carrier 80 adjacent arm 56. Pick-gear pawl 70, best shown in FIG. 4, is pivotally mounted adjacent the periphery of pick gear 66 by a stud 84 carried by arm 56. A spring 86 (FIGS. 3 & 4) biases the free end of pawl 70 toward the periphery of pick gear 66. The hub portion of shroud 68 is fixedly but adjustably secured, as by means of a set-screw 88, upon the hub of ring gear 76 for rotative movement therewith about the axis of shaft 16. Switch-mounting plates 43, 60 are respectively secured as by bolts 93, 89 to the forward most radical face of ring gear 76. Bolt 89 extends through the arcuate slot 62 within plate 60. This permits the arcuate distance between the switches 42, 40, respectively carried by plates 43, 60, to be readily adjusted when and as desired by simply loosening bolt 89 and adjusting the arcuate position of plate 89 relative to plate 43. Lastly, a stud member 90 projects forwardly from gear 76, for a purpose to be subsequently described.
For controlling the freedom of the aforesaid components for rotative movement in certain desired respects, there are provided in association therewith restraining means including a pawl 91 (FIGS. 3 and 5), and drag means including two annular discs 92,94. Pawl 91, which as indicated in FIG. 5 may for more reliable operation comprise plural elements of slightly differing lengths, is pivotally mounted upon the uppermost one of a plurality of studs 96 carried by and projecting forwardly from the face of the gear box 18. The free end of pawl 91 engages teeth provided about an adjacent part of the peripheral surface of ring gear 74. Such engagement prohibits counterclockwise rotation of ring gear 74, but permits its clockwise rotation. Studs 96 also serve to support disc 92, which is formed of material having a relatively high coefficient of friction, between radially-extending surfaces provided upon the confronting faces of ring gears 74,76. Engagement between friction disc 92 and the aforesaid surfaces of ring gears 74,76 is maintained by the second disc 94 and biasing means associated therewith. Disc 94 loosely encircles that portion of the hub of planet carrier 80 intermediate pick gear 66 and the adjacent radial surfaces of the hubs of ring gear 76 and shroud member 68. Pin elements 98 (FIG. 5) project forwardly from disc 94 into cooperating bores provided within the rearward radial face of pick gear 66, and secure disc 94 and pick gear 66 for rotary movement in unison with one another while permitting movement of disc 94 in the axial direction of shaft 16. Housed within suitable recesses also provided in the rearward radial face of pick gear 66 are a plurality of compression springs 100, one of which is shown in FIG. 5, which bias disc 94 into engagement with the adjacent radial faces of the hubs of ring gear 76 and shroud 68. Such engagement in turn biases ring gear 76 against friction disc 92, and maintains frictional engagement of such friction disc with both ring gears 74,76. The magnitude of the frictional engagement of disc 92 with ring gears 74,76 is such as to prevent machine vibration and the like from causing "creeping" rotary movement of the ring gears, and particularly ring gear 76 and the components secured to it, at those times during which differential gearing assembly 72 is not being driven and its components are intended to remain stationary. On the other hand, the magnitude of the aforesaid frictional engagement between disc 92 and ring gears 74,76 is sufficiently small as to permit rotative movement of gear 76 relative to gear 74 when assembly 72 is positively driven.
Referring now particularly to FIG. 3, assembly 72 is periodically positively driven during normal package-building operation of machine 10. The solid and phantom-line showings in FIG. 3 of switch-plate 43 arm 56, switch-plate 60, shroud 68 and ring gear 76 respectively represent positions occupied by such components during initial and terminal phases of a package-building operation by machine 10. As indicated by the double-headed arrow upon arm 56, and as previously described, such arm oscillates to and fro between reversing switches 40,42 under the impetus of the oscillatory movement imparted to shaft 16 by drive means 20 and the reversals of its driving input which are effected by the alternating proximity-actuation of reed switches 40,42 by magnet 50 (FIG. 4) carried by arm 56. During the final counterclockwise part of each oscillatory stroke of movement of arm 56 the pawl 70 which is carried by such arm, and which normally rides upon the shroud 68 overlying the adjacent portion of the peripheral surface of pick gear 66, is advanced past the leading end (the uppermost end, as viewed in FIG. 3) of shroud 68. The free end of pawl 70 thereupon engages the toothed periphery of pick gear 66 and, under the impetus of that final counterclockwise rotation of shaft 16 and arm 56 occurring immediately prior to actuation of switch 40 by magnet 50 (FIG. 4), imparts limited counterclockwise rotative movement -- the magnitude of which is determined by the adjustive angular position in which set screw 88 (FIG. 5) secures shroud 68 to the hub of ring gear 76 -- to pick gear 66. Since pick gear 66 is keyed or otherwise suitably affixed to the hub of planet carrier 80 of differential gearing assembly 72, the aforesaid rotation of the pick gear causes counterclockwise rotation of planet carrier 80 and ensuing clockwise rotation of the planet gear or gears 82 carried thereby and meshing with the internal gear teeth of ring gears 74,76. Inasmuch as pawl 91 prohibits counterclockwise rotation of ring gear 74, which constitutes the "control" gearing member of assembly 72, the net effect of the foregoing driving input into assembly 72 from shaft 16 to produce a limited angular advancement, in a counterclockwise direction, or "output" ring gear 76 and the components carried by and movable with it; i.e., shroud 68, plates 43, 60, switches 40, 42, and stud 90. The magnitude of such angular advancement of ring gear 76 and the aforesaid associated components is of course much less than the magnitude of the pick-gear rotation which produced it, due to the fact that the internal gear teeth upon the respective ring gears 74, 76 differ only slightly in number.
Due to the aforesaid advancement of switch plates 43, 60, and more particularly due to the advancement of the reed switches 40, 42 carried thereby and determinative of the extremities of each stroke of oscillatory movement of shaft 16 and arm 56, the next-ensuing one of such strokes will be correspondingly advanced in a counterclockwise angular direction about the axis of shaft 16, causing upward advancement of the then simultaneously-ensuing reciprocatory stroke of ring rails 12, 12' (FIG. 1). Similar stepped advancements of the components continue to occur until the package-building operation is completed, at which time ring rails 12, 12' will occupy their uppermost positions and arm 56 and ring gear 76, together with the components carried by and movable in unison with such ring gear, will occupy extreme counterclockwise positions adjacent those indicated in phantom lines in FIG. 3. Actuation of cover-plate reed switch 44 (FIGS. 2 & 4) by magnet 52 (FIGS. 3 & 4) then causes drive means 20 to rotate shaft 16 in a clockwise direction and thus "wind-down" ring rails 12, 12'. Such movement of shaft 16 and ring rails 12, 12' is haulted by magnet 52 actuating cover-plate reed switch 48 (FIGS. 2 and 4) when arm 56 has been rotated back to its initial angular position (not shown, but adjacent in a counterclockwise direction to the solid-line showing of arm 56 in FIG. 3).
During the above-described "wind-down" movements of shaft 16 and arm 56 in a clockwise direction, arm 56 engages the stud 90 carried by and projecting forwardly from ring gear 76 and, under the impetus of such engagement, rotates ring gear 76 and the additional components carried by it (i.e., shroud 68, switch plate 43, 60, and switches 40, 42) back to their original angular positions shown in solid lines in FIG. 3. This return movement of ring gear 76 in a clockwise direction occurs without overstressing any components of differential gearing assembly 72 due to the fact that pawl 91 permits clockwise rotation of ring gear 74 at such time, as a consequence of which planet carrier 80 remains substantially stationary. The return movement of ring gear 76 and the components carried by it is of course not dependent upon the "wind-down" step being initiated by switch 44. Such return movement would still transpire in the described manner if "wind-down" were initiated in other ways, as by a switch actuable by a yardage-counter (not shown) or one manually operable by a machine-operator. It would also still transpire if the clockwise rotation of shaft 16 were producted manually, as by the provision of a hand-crank (not shown) driveably engagable therewith. However wind-down of rails 12, 12' might be initiated or produced, it will therefore be apparent that at the completion thereof all components of builder control means 22 will be properly positioned for the next package building operation of machine 10.
The compact arrangement of all components of builder control means 22 adjacent an end portion of shaft 16 is desirable for various reasons. It permits the control components and adjacent portion of shaft 16 to be housed within a locked compartment of an end-cabinet (not shown) of machine 10 where they are shielded from lint and dirt and are secure from unauthorized tampering, but are all readily accessible to authorized personnel for purposes of adjustment or the like. In the latter connection, adjustment of the lengths of the package-building strokes of movement of shaft 16 and ring rails 12, 12' may be readily effected by varying the angular distance between switches 40, 42. As previously described, this is accomplished simply by loosening bolt 89, moving plate 60 relative to plate 43, and then retightening bolt 89. Adjustment of the "gain" effected by control means 22 may be realized with equal ease in the manner previously noted; i.e., by loosening set-screw 88 (FIG. 5) and varying the angular position of shroud 68 about the hub of ring gear 76. At such time as set-screw 58 is loosened, it will also be appreciated that all components of the present mechanism may, if desired, be removed completely from shaft 16 simple by sliding the same forwardly past the shaft's free end. This capability greatly facilitates installation, inspection and maintenance of the builder mechanism.
While a preferred embodiment of the invention has been specifically shown and described, this was for purposes of illustration only, and not for purposes of limitation, the scope of the invention being in accordance with the following claims.
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All control components of the builder mechanism and its pick motion device are concentrically arranged about the builder shaft of a textile machine in such manner that the builder mechanism can readily be removed from the builder shaft as an entity for replacement, inspection, repair or substitution of parts, creating a compact construction of great durability and easy maintenance. Such concentrically disposed components include electromechanical control means for at prescribed times effecting directional reversals and stepped advancements of the points of movement reversals of the builder shaft with a differential gearing assembly which produces incremental angular advancements of switch components about the axis shaft when driven by pick-gear wheel and pick-gear pawl members thereof.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This is a continuation-in-part of identically titled application Ser. No. 12/714,672, filed Mar. 1, 2010.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention is broadly concerned with decorative cover assemblies designed to cover a propane tank (e.g., a standard 20 lb. household tank) and to present the three-dimensional appearance or likeness of a sports-related item, such as athletic headgear or athletic balls. More specifically, the invention is directed to such cover assemblies which may be separate from a propane tank or integrated therewith, and which may be formed of any suitable material, such as metal or synthetic resin. Exemplary cover assemblies in accordance with the invention may be solid, hollow, or inflatable.
[0004] 2. Description of the Prior Art
[0005] A tailgate party is a social event held on or around the open tailgates of vehicles. Tailgating traditionally involves consuming beverages and grilling food. Tailgate parties often occur in the parking lots of stadiums and arenas before, during, and after sporting events. For example, tailgate parties have become particularly popular in the U.S. as social gatherings that take place in stadium parking lots before football games. As an adjunct to such parties, tailgaters have flags, pennants, outerwear such as shirts, jackets, and caps, and all manner of other items, bearing the logo and/or name of their favorite team. Such team identification is deemed essential by tailgate participants.
[0006] Dedicated tailgaters sometimes have elaborate portable equipment for grilling of foods. Thus, many tailgaters have portable propane grills making use of one or more standard household propane tanks. These tanks are generally white in color and are positioned beneath the grill. As such, the tanks are unsightly and do not contribute to the festive atmosphere of a tailgate party. Various covers have been provided in the past for coolers and barbecue grills.
[0007] Additionally, flexible cloth-type covers for propane tanks have been proposed, which do not provide a definite, three-dimensional shape. See U.S. Pat. Nos. 4,705,085, 5,622,261, 6,237,787, 6,386,384, 6,401,951, and 6,866,159; U.S. Design Pat. Nos. D289,598, D351,971, D442,818, D486,551, D516,365, D572,478, D577,096, D577,097, D577,791, and D599,625; U.S. Published Patent Applications Nos. 2002/0175193, 2005/0205180, and 2007/0068957; Foreign Patent Publications Nos. AU2009100673 and GB2441056; and non-patent literature items entitled Baseball Jersey Grill Cover, BBQ Covers-Mustard Bottle, and Propane Tanks Cover.
[0008] It would therefore be a boon to tailgaters if unattractive and innocuous propane tanks could be decorated in a manner consistent with a tailgate party scheme, and particularly to give the appearance or likeness of a sports-related item consistent with the tailgate party theme.
SUMMARY OF THE INVENTION
[0009] The present invention addresses the problem outlined above, and provides decorated propane tanks with sports-related themes. In some embodiments, cover assemblies for propane tanks are provided, each comprising a decorative body having wall structure designed to surround a propane tank with a substantially rigid outer wall configured to present a three-dimensional likeness or appearance of a sports-related item. The wall structure may also include an inner wall designed to mate with a propane tank (i.e., the inner wall is configured to rest upon or otherwise be supported by a propane tank wall). The cover assembly may be separable from a propane tank, can be integrated with the tank, or the tank may be formed with the decorative surface aspects, such that there is no separate tank. The outer surface of the cover assembly is typically designed to give the three-dimensional likeness or appearance of things such as athletic headgear, athletic footwear, athletic balls, or other athletic equipment.
[0010] As noted, the cover assemblies have substantially rigid outer walls defining the corresponding sports-related item, and preferably the entirety of the decorative bodies are of substantially rigid construction. The bodies have upper margins below the valve associated with the propane tank. In this fashion, the valve may be connected to a barbecue grill, for example, without interference by the cover assemblies. Thus, the propane tank can be used in the usual fashion with the cover assemblies of the invention in place. Moreover, the cover assemblies of the invention are not inflatable, as in the case of certain prior art covers; it is believed that such inflatable designs would not provide the degree of verisimilitude that can be achieved with the substantially rigid designs of the invention.
[0011] As used herein, with reference to the cover assembly bodies of the invention “three-dimensional” means that a given cover assembly body presents a contoured or concavo-convex outer surface, preferably with portions of the outer surface spaced a significant distance (preferably at least about one-half inch, and most preferably at least about one inch) from the proximal propane tank wall. Such three-dimensional cover assemblies thus are distinctly different from conventional two-dimensional images printed on a simple flexible tank cover or the like.
[0012] Hence, in the case of a cover assembly body having a simulated athletic headgear outer surface, the headgear is broadly selected from the group consisting of athletic helmets, caps, and hats, e.g., helmets for racing, football, lacrosse, baseball batting, rodeo, fencing, skiing and other winter sports, bicycling, hockey, and boxing. In the case of athletic footwear, the cover assembly body may present the three-dimensional appearance of footwear for soccer, football, hockey, basketball, track, skiing, boxing, golf, ballet, and bicycling. A wide variety of athletic cover assembly bodies may give the three-dimensional appearance of a simulated athletic ball, for example balls selected from the group consisting of baseballs, basketballs, cricket balls, tennis balls, footballs, rugby balls, lacrosse balls, baoding balls, billiard balls, table tennis balls, bowling balls, handballs, soccer balls, wiffle balls, polo balls, golf balls, racquet balls, beach balls, and volley balls. Other cover assembly bodies giving the three-dimensional appearance of simulated sports-related items may include covers giving the three-dimensional appearance of athletic apparel selected from the group consisting of jerseys, shirts, jackets, shorts, pants, stockings, pads, and gloves, hockey pucks, curling stones, racquets, mallets, baseball bats, hockey sticks, and basketball nets. In short, the scope of the present invention is limited only by the imagination of the fabricator.
[0013] It will also be appreciated that, in most instances, the outer surface of a given cover assembly would also include the name and/or logo of a specific team or athlete. In this way, the user can both decorate an otherwise bland-looking propane tank, while also proclaiming loyalty to the user's favorite team or athlete.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a front perspective view of the combination of a standard household propane tank with a detachable, dual section cover assembly in accordance with the invention and presenting the likeness of an automobile racing helmet, wherein the cover assembly is mounted on the tank;
[0015] FIG. 2 is a rear perspective view similar to that of FIG. 1 , but illustrating the surface structure of the cover assembly opposite that of FIG. 1 ;
[0016] FIG. 3 is a plan view of the combination depicted in FIG. 1 ;
[0017] FIG. 4 is a partial sectional view of the combination depicted in FIG. 1 ;
[0018] FIG. 5 is an exploded view of the combination of FIG. 1 , illustrating the cover assembly in its open configuration before being mounted on to the propane tank;
[0019] FIG. 6 is a front perspective view of an integrated propane tank and cover assembly in accordance with the invention, the cover assembly presenting the likeness of a football helmet;
[0020] FIG. 7 is an elevational view of the assembly of FIG. 6 ;
[0021] FIG. 8 is a rear perspective view of the assembly of FIG. 6 ;
[0022] FIG. 9 is a plan view of the assembly of FIG. 6 ;
[0023] FIG. 10 is front perspective view of a combination comprising a standard household propane tank with a unitary, one-piece cover assembly in accordance with the invention releasably mounted on the tank, the cover assembly presenting the likeness of a racing helmet;
[0024] FIG. 11 is an elevational view of the combination illustrated in FIG. 10 ;
[0025] FIG. 12 is a partial sectional view of the combination illustrated in FIG. 10 ;
[0026] FIG. 13 is a vertical sectional view of the one-piece cover assembly separate from the tank;
[0027] FIG. 14 is a front perspective view of the combination comprising a standard household propane tank with a hollow molded cover assembly in accordance with the invention mounted on the tank, with the cover assembly presenting the likeness of a football helmet;
[0028] FIG. 15 is an elevational view of the combination illustrated in FIG. 14 ;
[0029] FIG. 16 is partial sectional view of the combination of FIG. 14 ;
[0030] FIG. 17 is a vertical sectional view of the hollow molded cover assembly of FIG. 14 , shown separate from the tank; and
[0031] FIG. 18 is a perspective view of a combination comprising a standard household propane tank with a cover assembly in accordance with the invention mounted on the tank, the cover assembly presenting the likeness of a basketball.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0032] Turning now to FIGS. 1-5 , a combination 30 is illustrated including a standard household propane tank 32 and a detachable, two-piece cover assembly 34 . The tank 32 (see FIG. 4 ) includes an upright hollow propane-holding container 36 having a circular base 38 and rounded upper and lower shouldered walls 40 , 42 . A standard propane tank valve 44 is secured at the top of the tank and extends above the wall 40 , with a carrying and connection cage 46 disposed partially about the valve 44 . It will be appreciated that the tank 32 is itself wholly conventional.
[0033] The cover assembly 34 in this embodiment is made up of a rigid body preferably formed of an appropriate synthetic resin material and having front and rear sections 48 and 50 which are hingedly interconnected by means of hinge structure 52 . The edges of the sections 48 and 50 opposite hinge structure 52 are provided with mating latch structures 54 and 56 . As best seen in FIG. 5 , the inner surface 58 of the cover assembly 34 is made up of front and rear section inner surfaces 60 and 62 . These surfaces are designed to substantially surround the tank 32 and are further provided with a number of inwardly extending engagement blocks 64 . As illustrated in FIG. 4 , the blocks 64 are designed to firmly engage the wall of container 36 so as to prevent inadvertent axial or rotational movement of the cover assembly 34 relative to tank 32 . It will further be observed that the cover assembly sections 48 and 50 cooperatively present an upper margin defining upper opening 66 , which is disposed about cage 46 and valve 44 , and a lower margin defining lower opening 68 , which extends about the lower portion of tank 32 .
[0034] In this embodiment, the outer surface 70 of the assembly 34 , made up of substantially rigid front and rear walls 72 and 74 , gives the three-dimensional likeness and appearance of an automobile racing helmet. Thus, the front wall 72 has a simulated visor 76 presenting concavo-convex surfaces, as well as a downwardly and outwardly extending chin section 78 . In use, the cover assembly 34 is opened as depicted in FIG. 5 , and closed about the tank 32 so that the latch structures 54 and 56 mate and engage. Removal of the cover assembly is accomplished by opening the latch structures and swinging the cover sections 48 and 50 apart.
[0035] FIGS. 6-9 illustrate another embodiment in the form of a combination 80 made up of an integrated propane tank 82 and cover assembly 84 . In this case, the assembly 84 has a body presenting a rigid wall defining outer surface 86 , giving the three-dimensional appearance or likeness of a football helmet. The latter has a rounded surface characteristic of football helmets, along with simulated ear holes 88 and an outwardly projecting mask 90 . The combination 80 further includes an upper valve 44 and cage 46 , as previously described. Internally, the combination 80 may have a standard household propane tank, as described above, with the cover assembly 84 welded or otherwise permanently secured to the tank.
[0036] FIGS. 10-13 illustrate another form of the invention made of a combination 92 having a standard propane tank 32 , described previously, and a molded, one-piece, substantially rigid, synthetic resin cover assembly 94 . As best seen in FIGS. 12 and 13 , the cover assembly 94 has a body presenting upper margin defining an upper opening 96 designed to surround and remain below cage 46 and valve 44 , and a lower margin defining lower opening 98 . The inner surface 100 of the assembly 94 is configured to closely mate with the outer wall of container 36 and shoulder 40 . The assembly 94 may thus be installed on tank 32 simply by positioning the lower opening 98 above the tank and sliding the cover assembly 94 onto the tank to assume the position shown in FIG. 12 . The cover can of course also be readily removed from the tank 32 by reversing this procedure. The cover assembly 94 can be fabricated from any suitable synthetic resin material, such as compressible polyurethane 102 . The outer skin or surface 104 thereof is configured to give the three-dimensional likeness or appearance of an automotive racing helmet, as in the case of the first embodiment.
[0037] FIGS. 14-16 depict another embodiment, in the form of combination 106 again comprising a standard propane tank 32 and a cover assembly 108 . The latter is in the form of a body having an inner wall 110 , an outer wall 112 , an upper margin defining upper opening 114 , and a lower margin defining lower opening 116 . Thus, the cover assembly 108 is a unitary, substantially rigid structure, similar to the cover assembly 94 . The inner wall 110 is designed to closely mate with the outer surfaces of tank 32 , whereas the outer wall 112 gives the three-dimensional likeness or appearance of a football helmet, including simulated ear holes 118 and an outwardly projecting face mask 120 . In this instance, however, the cover assembly 108 is a substantially rigid, hollow body presenting air space 122 between the inner and outer walls 110 and 112 , and can be conveniently produced by standard rotary molding or other conventional techniques. The use of assembly 108 is the same as that described with respect to unitary cover assembly 94 , i.e., the cover 108 can be positioned above a tank 32 and slid into place, as shown in FIG. 16 .
[0038] FIG. 18 illustrates a combination 142 comprising a standard propane tank 32 and a cover assembly 144 . The assembly 144 has a substantially rigid body of unitary, one-piece construction as in earlier embodiments. Thus, the cover assembly 144 includes an inner surface (not shown) configured to mate with the outer surface of tank 32 and has upper and lower margins respectively defining openings 146 , 148 allowing the assembly to be positioned over the tank 32 . In this instance, the outer surface 150 of the assembly 144 presents the three-dimensional appearance of a basketball having simulations of typical sections and intervening seams. The cover assembly 144 may be hollow or filled.
[0039] It will thus be appreciated that the present invention provides a wide array of sports-related propane tank covers and combinations, which may be sectionalized, as illustrated in FIGS. 1-5 , or unitary, as depicted in FIGS. 6-18 . Alternately, combined assemblies can be made wherein the tank and cover assembly are unitized, as illustrated in FIGS. 6-9 .
[0040] Furthermore, while the invention has been illustrated in the context of standard household propane tanks, the principles of the invention can be equally applied to larger or differently-configured propane tanks. Thus, the term “propane tank” as used herein should be understood to embrace all shapes and sizes of propane tanks. Additionally, the cover assemblies may be separate from or used with any size or shape of propane tank, or a propane tank may be fabricated from two or more sections by welding the sections together, wherein at least some of the sections have preformed surface design features in accordance with the invention, so that the completed tank has the likeness or appearance of a sports-related item. It will be appreciated that this form of the invention does not make use of a pre-existing or pre-formed propane tank.
[0041] As noted previously, the cover assemblies of the invention are characterized by substantially rigid outer walls configured to closely resemble a sports-related item. In many preferred forms, the entireties of the assemblies are of substantially rigid design.
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Three-dimensional, sports-related cover assemblies ( 34, 84, 94, 108, 126, 144 ) for propane tanks ( 32 ) are provided in order to permit sport- or team-related decoration of the tanks ( 32 ). The cover assemblies ( 34, 84, 94, 108, 126, 144 ) may be separable from the tanks ( 32 ) or may be integrated and unitized with the tanks ( 32 ). The assemblies ( 34, 84, 94, 108, 126, 144 ) have substantially rigid, contoured or concavo-convex outer walls presenting surfaces ( 70, 86, 104, 112, 130, 150 ), which are configured to give the three-dimensional likeness or appearance of a sports-related item, such as athletic head gear, footwear, balls, or other equipment.
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BACKGROUND OF THE INVENTION
A new flow system is invented to remove or to reduce flow separation and its induced turbulence and cavitation.
BACKGROUND-DESCRIPTION OF PRIOR ART
Turbulence created in pipe elbows causes increased erosion, noise, vibration, and stress cracking. If an elbow is located too close to a check valve, it can cause chattering and damage to the valve seat. In the case of a nuclear power plant, it can threaten the safety of the plant. In a condenser cooling system, the turbulence causes uneven flow in the cooling water box, in turn reducing the heat transfer effectiveness. Erosion of an elbow in a wet steam line or in refinery piping carrying catalyst particulates can cause unexpected down time. In nuclear power plants, sometimes a double blanket "tee" is used to dampen the fluid impact during turns. Others have used a Vortex ball to absorb the impact energy in areas which normally have a high rate of erosion. Thickening the wall and using stainless steel 316, Titanium and Chrome-Moly are common patch-up solutions currently. Other methods of turning vanes in wind tunnels and critical flow systems are required to eliminate some of the large-scale turbulence, but small-scale turbulence still exists. The methods in prior art may make the pipe system more safe or elongate the maintenance period, but the inherent problems of elbow-induced turbulence have never been removed. This is a very complicated fluid mechanics problem which involves potential flow, compressibility, and viscous flow. The turbulence is a result of rotation of the flow by the elbow, with the law of nature trying to return to a homogenized state in a short time. The prior art "fixes" did not address the cause of the turbulence; hence, have not been very successful.
SUMMARY OF THE INVENTION
My invention resulted from theoretical study and by reducing the problem to a geometrical problem known as rotational transformation in a magnetic confinement system of plasmas, first incorporated in the Stellarator, and used in many other areas of magnetic geometry with a stable plasma confinement. My invention recognizes the mathematic similarity of fluid flow streamlines and magnetic flux lines and their associated problems. When a magnetic flux tube is bent with a certain radius of curvature, the inner radius will have magnetic flux compressed, and the outer radius expanded. This induces a phenomena called Gradient (B). Plasma confined in such a field will be lost in a phenomena called Gradient (B) drift. This plasma with its loss of pressure and directed kinetic energy is similar to fluid flow and its elbow-induced turbulence. The rotational transformation in a magnetic field is a mathematic solution in that the magnetic flux is being rotated about the flux tube axis so that the flux lines going through a bend will have equal length.
In fluid flow, viscosity and pressure head are involved. The rotational transformation as invented here requires a pre-rotator before the fluid enters the elbow. The invented system is called the Cheng Laminar Flow Elbow System, which consists of a pre-rotator and a matched elbow as a set. The pre-rotator is designed so that the flow streamlines going through the turn of an elbow will have equal length. The objectives of the present invention are:
(a) to reduce elbow-induced turbulence;
(b) to reduce pressure loss through an elbow;
(c) to provide a uniform flow field so that no acceleration or deceleration will be induced, most important in two-phase flow or particle laden flow streams;
(d) to remove cavitation and erosion in pipe flows;
(e) to increase pipe flow efficiency; and
(f) to increase the quietness of piping systems.
The advantages of the present invention are:
(1) The system has no moving parts.
(2) The system is independent of fluid flow velocity.
(3) The system is rigid and has little blockage to the flow.
(4) The system can be monitored for effectiveness in pressure drops of the elbow and across the pre-rotator.
(5) The system in larger pipe sizes can be installed on site.
(6) The system reduces turbulence-induced vibration and stress cracking of pipes.
(7) The system reduces erosion of pipe in two-phase flow.
(8) The system increases pressure loss in the reverse direction; therefore, reduces water hammer problem.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an illustration of the actual flow streamline as viewed in experimental photographs of injected dye flowing through pipes and FIG. 1A is a sectional view of the pipe shown in FIG. 1.
FIG. 2 is an illustration of pressure distribution and secondary flow in a 90° turn elbow and its pressure distribution at the outer wall of the elbow and the inner wall of the elbow to indicate the cause of induced secondary flow in the separation.
FIG. 3 is an illustration of sub-cooled water feed pumps through an elbow that go through a vapor phase cavitation and recovery cycle in accordance with FIG. 2.
FIG. 4 is an illustration of equal streamline length flow desired to achieve rotational transformation mathematically.
FIGS. 5A-5C, hereafter collectively referred to as FIG. 5, illustrate the pre-rotator ahead of the elbow and the mathematical relationship between the turning radius, the pipe diameter and the total angle of turns.
FIGS. 6A and 6B, hereafter collectively referred to as FIG. 6 illustrate a head-on and side view of a prerotator according to a rotational transformed solution that totally compensates the rotation induced by elbow flows.
FIGS. 7A and 7B, hereafter collectively referred to as FIG. 7, illustrate the comparison of an elbow with rotational turning vane versus without rotational turning vane as real experimental results from a reduction in practice.
FIG. 8 is a description of the turning vane angle and the radius of the turning vane relating to the diameter of the particulate size or steam droplet size and the flow velocity such that the particle will not be separated from the main flow.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 illustrates the streamlines inside a pipe with an elbow. The streamline shape was photographed through a movie picture, and the streamlines were injected with colored dyes in a transparent Lucite pipe 10. The streamlines are bunched together at 12. As we can see, the streamlines are separate from the wall in the upper corner, and also separate from the wall on the inside corner. The cross section of the pipe 14 downstream Of the elbow is depicted as cross section A/A. Cross section A/A is the smallest area the flow has contracted to.
The cross sectional view of the pipe is shown separately in FIG. 1a. The shaded area 16 is shaped like a half moon. The contraction is similar to an orifice plate, and the streamline pulling from the outside wall of the pipe had never been observed by anyone prior to our experiment. The reason the streamline is pulling away from the outside wall is because the contraction due to acceleration of the fluid through a smaller area has to follow a certain streamline pattern, and the acceleration to the small area causes the fluid to separate from the outside wall. This separation region also causes accumulation of droplets and particulates, and is damaging to pipes. The separation of the inside wall of the elbow generates turbulence, cavitation, stress and noise downstream of the elbow. These two separation regions and the necessity for their removal was the focus of my invention.
FIG. 2 further illustrates the pressure measurement across the inner and outer wall of an elbow through a liquid fluid at a relatively high speed. The elbow pressure is measured at the locations on the inside wall labeled 1, 2, 3, 4, 5; and on the outside wall labeled as 1, A and 5. Here B coincides with position 3. The cross section AB is shown at the bottom of FIG. 2. The pressure distribution measured was a classical case; for instance, the outside of the pipe on the upper part of the curve, which is normalized by the kinetic head and pressure head, starts at 1, and increases to a higher level at point A. This is due to the stagnation and the centrifugal force, which then accelerates the fluid from A to position 5; therefore, the pressure drops dramatically. This acceleration is due to the contraction of the fluid after the elbow. On the other hand, the pressure distribution on the inside of the elbow turn starts from point 1, gradually decreases to point 2, then to a minimal point 3, then recovers to point 4 and point 5. This low-pressure dip relative to the position at the opposite side, point A, creates a very large pressure gradient, which is the reason the droplets or other particulates can be accelerated by this pressure gradient to hit the wall and cause erosions. Also, the drop in pressure will cause cavitation if the fluid contains low volatile materials rather than a pure gas.
At point 1, the water pressure is high; therefore, it's called subcooled water below the boiling temperature of the fluid. The pressure and the boiling temperature curve is shown as a curve separating the points 1, 2, 3, 4, 5. The points 1, 2, 3, 4, 5 correspond to the points 1, 2, 3, 4, 5 in FIG. 2. When the pressure is dropped from point 1 to point 2, which reaches the boiling temperature of the water under a lower pressure, the water is ready to be flashed into steam, which will continue to drop the pressure to point 3, which is clearly the vapor and steam phase. This is known as cavitation. It could happen not necessarily in a heated water situation. It is also caused by dissolved gas in water. The pressure is then recovered from point 3 to reach the condensation point under a lower temperature at point 4, then point 2. Because some of the latent heat is consumed during the evaporation, the temperature is dropped dramatically from point 2 to point 3, and usually the temperature fluctuates in that separation region. The pressure is continually recovered from point 4 to point 5 to complete the whole turn of the fluid through the elbow. However, the damage of the elbow is created in the region of point 2 to point 3, and point 3 to point 4, which not only has cavitation, but also temperature turbulence fatigue, which causes temperature stress fatigue and also chemical stress fatigue.
In FIG. 4, the elbow system 18 would require a different streamline pattern a depicted by 20. The streamline would require the same length starting from cross section AA, and would reach cross section BB at the same time and at the same velocity by designing a pre-rotational flow according to the rotational transformation formula. In general, the streamline is more complicated than this; however, this illustrates a typical 90 degree turn elbow only. A feature of the pre-rotator under the rotational transformation rule is that the streamline started on the outermost wall of the pipe, after going through the elbow, reaches the innermost wall of the elbow, and the streamline on the innermost wall of the elbow will reach the outermost position after going through the elbow. The inside streamlines generally have no change in position; in other words, no rotation occurs at the center lines. It was demonstrated later by the pre-rotator design, according to rotational transformation, that if the turning vane is designed properly, the fluid will have a rotation above the center line and also perpendicular to the center line, creating a compound curve to compensate for the rotation due to the elbow. The reason it requires two components of rotation to compensate for one rotation is due to the vector analysis of three-dimensional Curl functions. The Curl function requires the cross product of a vector, normally consisting of two terms; therefore, the pre-rotator has to be designed accordingly to make the total compensation work. Experimentally, my invention shows that when the pre-rotator is properly designed, the fluid is pre-rotated entering the elbow and going through the elbow, reaching position BB. From thereon, the fluid stops rotation all by itself, and the fluid in the pipe is going straight beyond that point. In other words, turbulence is not generated through the elbow, and cavitation on the inside and outside is totally eliminated. The velocity of the fluid going through the elbow maintains a constant pace without acceleration or deceleration, which is the main cause of the droplets carried by the fluid to be separated from the main bodies.
FIG. 5 is an illustration of the pre-rotator and its relationship to the, elbow turns. The pre-rotator 26 is located in the pipe 24 ahead of the elbow 22 connected to pipe flange 24A. The relationship of the turning angle will be shown later; however, the relationship relates to the geometry of the elbow 22 according to the diameter of the elbow D and the turning radius R 10 . 28 is the center of the rotation of the elbow.
FIG. 6A illustrates the results of a typical geometry viewed in the direction of the fluid flow, and also on the side. As one can see by the direction of the fluid flow, as shown in FIG. 6B, wherein the fluid flowing through a pipe has a central axis the turning vanes which are symmetrically oriented around the fluid flow axis, each vane has a compound curvature that is a result of the rotation in the axial direction and also in the R direction. In the axial direction, the angle is called a Theta, and on the side view, we can see the fluid goes into the turning vane without any angle of attack, coming out with a maximum angle of turn, Theta max, and the radius for the fluid to reach the Theta max is called R 30 . According to simplified mathematical calculations under rotational transformation, the Theta max is equal to one quarter the pipe diameter divided by the radius of the turn (R 10 ) times the total inclusion angle of the turn (Phi). For any angle in between the center line to the outer edge (Theta 1), simply substitute the pipe diameter with the appropriate diameter (D1). The projected view would have a compound curve, as shown in cross section AA. The radius of curvature R 30 is arbitrary if no two-phase flow problem is considered. It is also a critical design parameter when wet steam is flowing through the turning vane. Separate droplets or particles will be carried by the stream under a relatively small velocity to the stream, called a slip stream, such that the centrifugal force should be smaller than the slip stream so the particles will be rotating with the fluid instead of separating from the streamline and hitting the wall. The radius (R 30 ) relates to the maximum diameter of the particle the stream is carrying.
FIG. 7 is a set of actual experimental measurements of the same elbow with and without rotational transformed turning vanes ahead of the elbow. 7a is the pressure distribution measured on the inside and outside wall of the elbow. The pressure is measured by pressure taps and manometer boards. It can be shown that the pressure distribution is very uniform from the inside and outside of the pipe flows, in contrast to FIG. 7b, where the pressure is increased on the outside wall and is also creating almost a suction on the inside wall. This is the classical case as depicted in FIGS. 2 and 3. On the other hand, 7a's deviation in pressure through the elbow has been totally removed. The pressure loss of flow in an elbow is usually measured in the industry in terms of the equivalent pipe length for the same pressure loss according to the diameter of the pipe. Typical pressure losses for industrial application flow Reynolds numbers in an elbow are equivalent to a 30 diameter length of straight pipe. On the other hand, in the case of 7a, the pressure loss is almost the same as a straight pipe; therefore, an equivalent length of pressure loss is significantly reduced. This not only saves energy in plant operations, but removes the turbulence it generates and the cavitation and other things causing a piping system to be damaged. This certainly has consequences of saving energy and creating safety for thermal power plants, as well as nuclear power plants.
FIG. 8 shows the section of a turning vane 30 at the maximum turning angle. The turning radius is R 30 . The velocity of the flow stream is V f , and the diameter of the largest particle or droplets carried by the stream is d. The relative velocity going across the streamline is V v . The radius R 30 is designed such that the largest particle carried by the stream will not hit the wall, or at least will minimize the percentage of the largest droplet carried by the fluid to hit the turning vane wall. Mathematically, the reason the particle can be carried by the bulk of the stream is that the relative velocity of the particle and the stream is very small. The viscous force, which is the reason that the particles are carried by the fluid stream, can be quantified through the drag coefficient, as measured by the Reynolds number, based on the relative streams and the diameter of the particles. The larger the Reynolds number, the smaller the drag forces. The Reynolds number is a function of the density, the velocity and the particle diameter divided by the viscosity of the fluid; therefore, basically the formula as given is that the drag coefficient in the region allows particles to be carried by the stream, called Stoke's flow regime. The drag coefficient (C o ) is equal to 30 divided by the Reynolds number (R ed ). The drag force is equal to 15 times the density of the fluid (ρ f ), the main velocity of the stream (V f 2 ) times Pi, times the diameter (d) of the particulates squared, divided by the Reynolds number (R ed ). Basically, this sets up a very unstable situation such that the larger the Reynolds number, the smaller will be the drag forces. In other words, the particulate can be carried by the stream as long as the relative velocity of the particles with respect to the fluid is small. When the particle is accelerated away from the stream, the relative velocity becomes increased, and the Reynolds number also is increased. This in turn reduces the drag forces to hold onto the particle, which can cause an unstable runaway situation. The centrifugal force, however, caused by the turning vane can be shown in the equation as F c .f. equals the density of the particulates (ρ s ) times 4 Pi divided by 3, the diameter cubed times the relative velocity squared divided by the radius of curvature of the turning vane (R 30 ). If the Reynolds number chosen still has a relatively large viscous force to retain the particles, then we can determine the relationship between the diameter and the turning radius of the vane designs. If we equate the viscous force drag and the centrifugal force to obtain a Reynolds number, we will find the equation as shown should be less than 100 to retain the relatively high viscous forces within the Stoke's flow regime. This Reynolds number, it turns out, is independent of the flow stream velocity, but is equal to the density of the solid to the density of fluid ratio, and the particulate size divided by the turning radius (R 30 ). This will be the criteria I use to design the turning vanes for two-phase flow.
As is evidenced from the description of the figures, a number of the drawings were derived from actual experimental test results, and from those results, the advantage of my invention becomes obvious. For example, through my design, the rotational transformed turning vane is a geometrical effect independent of the velocity of flow through the pipe system; therefore, the turning angle does not have to be changed in various operations of higher or lower velocities within the same pipe system. On the other hand, it also is true that the turning vane design is not an arbitrary design such that just rotating some fluid flow with certain plates would make the whole system work. The system has been tested in water tunnels extensively with a velocity range varied to a factor of 100. It definitely shows that the separation region of the elbow has been totally removed and the turbulence induced by the pipe flow has been removed. This in turn reduces the contraction area or removes the contraction area downstream of the elbow, hence, it reduces the pressure loss caused by flow through an elbow. It is also known that if the turning angle is larger than desired, then the fluid will continue to rotate after the elbow. On the one hand, the cavitation and the pressure loss due to the elbow is being removed; and on the other hand, the blockade due to the turning vanes is increased, so the turning vane design will have a trade-off between the pressure loss across the turning vane versus pressure reduced from removing the contraction area of the turning vane. Therefore, the maximum turning angle should be based on the formula given as follows:
Theta Max=1/4D/R.sub.10 ×Phi
Therefore, the maximum turning angle should not be more than what I have recommended. However, due to the trade-off of pressure losses, the maximum turning angle can be less than what I have shown in the formula. If the fluid is highly viscous or of very high velocity, then a careful trade-off between the pressure loss induced by the turning vane versus pressure reduction due to the turning vane would have to occur. It is also shown that the turning vane design is a compound surface whereby the fluid is rotated about the axis, and in the meantime, rotating perpendicular to the axis. The entrance into the rotation perpendicular to the axis will depend on the droplet size criteria, so a gentle entrance curve is recommended. The surprising results due to the flow in the reverse direction with this turning vane are that the fluid will experience angle of attack on entrance, therefore causing more resistance, making the piping system seem like a one-directional flow device. This has a benefit of reducing the water hammer effect caused by sudden increase or sudden drop or close of valves downstream of pipe systems.
SUMMARY, RAMIFICATIONS AND SCOPE
The summary of my invention is the discovery under the fundamental fluid dynamic principle that under the rotational transformation calculation of Curl function, that a turning vane can be designed to compensate the forced rotation of fluid through an elbow. The geometrical relationship of the turn in terms of the diameter of the pipe and the turning radius therefore relating to the turning vane design has been an important discovery, and verification experimentally has borne the theory out. The scope of the invention is trying to eliminate cavitation, turbulence induced by the elbow flow, erosion due to these phenomena in pipe flows, and application to two-phase flows that the fluid can carry droplets or particulates in its streams. The scope of the invention is not only to reduce the pressure loss and increase the energy efficiency of pipe systems, but also to reduce noise generated and the weight of the piping systems, and enhance the safety of such systems.
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A means and method of design and installation of a pre-rotator ahead of an elbow are disclosed in order to eliminate or reduce elbow-induced turbulence in pipe flows. Experimental verification was conducted, and noise and pressure loss for flow around the elbow can be substantially reduced.
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BACKGROUND OF THE INVENTION
The present invention relates to the flux for build-up welding, particularly suitable for "A Method for a Build-up Welding of Different Metals" for which a patent application has already been submitted by the same applicant of the present application under the same date.
As for the build-up welding of different metals, the band-like electrode submerged arc welding has hitherto been regarded as a superb welding method because it provides an excellently welded metal having less penetration with a high melting rate of electrode. However, A method for a build-up welding of different metals is still superior to the abovesaid conventional arc welding in all respects in that it provides a build-up-welded metal having a good yield of alloy elements with less penetration by using a thick and broad band-like electrode.
The embodiment of the invention according to the copending application abovementioned is proceeded with in the following manner: a flux powder is uniformly distributed over a horizontally disposed base metal to a substantially uniform thickness, and into the said flux, is continuously fed an electrode towards the base metal with an electric current applied therethrough. The flux between the free end of the electrode and the base metal is melted by an arc generated therebetween. and, once the flux has been melted, the arc disappears so that the melted flux is heated by the electric current supplied therethrough to such a high temperature as to melt both the electrode and the base metal, so the droplets of the electrode fall onto the melted base metal to form a deposite on it, thereby, upon movement of the electrode horizontally in the direction perpendicular to the width of the electrode, beads are formed on the base metal by the subsequent melting of the flux due to the Joule heat generated by an electric current flowing through the melted flux.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a flux which is suitable for use in the method for the build-up welding of different metals according to the copending patent application as aforementioned.
A flux according to the present invention is characterized in that it mainly comprises of 50- 90% by weight of calcium fluoride and 10- 40% of alumina and not more than 20% of additives selected from one or more of compounds consisting of the group of 0.5-7.0% of iron oxide, 2-10% of silica, 1-17% of manganese oxide and 2-10% of chrome oxide.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Following is a detailed explanation of the chemical components of the flux according to the present invention and grounds for their respective ranges in weight %:
Calcium fluoride and alumina composing the main components of the flux according to the present invention are the indispensable elements for realizing one of the features of the abovesaid invention according to the copending patent application that an electric current is applied through the melted slag without generating an arc so that the melted slag melts both the electrode and the base metal to be build-up-welded by the Joule heat, thereby a convection of the melted slag is generated to make the droplets of the electrode become intimate with the melted base metal so that a fine smooth bead with less penetration is formed. In this case, if the content of calcium fluoride is above 90%, the electric conductivity of the melted slag becomes so high that a smooth bead is hard to obtain because of the shortage of Joule heat, on the contrary, if the content of calcium fluoride is below 50%, the electric conductivity becomes so low that an arc occurs.
As alumina is added to calcium fluoride, the electric conductivity becomes low so that the generation of heat due to Joule heat becomes large, but, if the content of alumina is less than 10%, a smooth bead is hard to obtain because of the small generation of heat, while, if the content of alumina is more than 40%, an arc occurs. Further, in embodying the method for a build-up welding according to the copending patent application as abovesaid, it is impossible to obtain a smooth, fine bead by a mere mixture of calcium fluoride and alumina combined in the abovesaid ratio, and it has been found to be indispensable that, when the stability of the welding operation and the detachability of the slag are taken into consideration, the following oxides should be added:
Iron oxide to improve the electric conductivity and fluidity of the melted slag and the intimacy of the melted base metal with the droplets of the electrode, adjust the straightness of the toes of the bead. However, such effects fail to show themselves if the content of iron oxide is below 0.5%; on the contrary, if its content is above 7%, the fluidity of the melted slag and the intimacy of the droplets with the melted base metal become too good to obtain a fine smooth bead, besides, the purity of the build-up metal deteriorates.
Silica to improve the appearance of the bead, adjust both toes of the bead and improve the detachability of the slag, but such effects are unobservable if its content is below 2%; whereas on the contrary, with the content above 10%, an undesired arc tends to occur.
Manganese oxide to not only improve the appearance of the bead and the detachability of the slag, but also to increase the yield of manganese in the electrode; however, with its content less than 1%, such effects are not displayed; whereas on the contrary, if it is more than 17%, the adjustment of the components of the build-up metal becomes difficult since the content of manganese becomes excessive in the build-up metal.
Chrome oxide to reduce the fluidity of the melted slag, adjust the shape of the bead and improve the appearance of the bead, but if its content is less than 2%, such effects are not observable; whereas on the contrary, if it is above 10%, the detachability of the slag deteriorates.
Further, by taking into consideration on the detachability of the slag, it is preferable to add zirconium oxide in the range below 5%.
The following examples of embodiment will serve to illustrate the invention, although it should be understood that these examples are not intended to limit the scope of the invention.
EXAMPLE 1
a. Flux:
After a mixture comprising 66% by weight of calcium fluoride, 27% of alumina, 2% of iron oxide and 5% of silica is melted together, it is ground into powder after it has solidified.
b. Chemical composition of the band-like electrode (thickness of 0.4 mm, width of 75 mm): 0.025% C, 0.65% Si, 1.69% Mn, 9.9% Ni, 18.8% Cr, balance Fe.
c. Chemical composition of the base metal: 0.12% C, 0.29% Si, 1.38% Mn, 0.11% Ni, 0.25% Cr, balance Fe.
d. Welding conditions:
Using an welding condition of 1,400 A(DCRP), 22 V, 120 mm/min. DC-constant voltage characteristics, one-layer, build-up Welding was performed for austenite stainless steel (corresponding to the Japanese Industrial Standard: JIS 304); a beautiful, smooth bead, a build-up thickness of 5.5 to 6 mm, was obtained.
The chemical composition of the build-up-welded metal is shown in Table 1.
Table 1______________________________________Chemical composition of thebuild-up-welded metal in Example 1(%)______________________________________C Si Mn Ni Cr Fe0.027 0.29 1.38 9.8 18.5 Balance______________________________________
EXAMPLE 2
a. Flux:
After a mixture comprising, 64% by weight of calcium fluoride, 17% of alumina, 5% of iron oxide, 4% of silica, 3% of manganese oxide, 5% of chrome oxide and 2% of zirconium oxide is melted together, it is ground into powder after it has solidified.
b. Chemical composition of the band-like electrode (having a thickness of 1 mm and a width of 75 mm): 0.025% C, 0.19% Si, 1.78% Mn, 10.9% Ni, 20.5% Cr, 0.98% Nb, 0.08% Mo, balance Fe.
c. Chemical composition of the base metal: 0.14% C, 0.21% Si, 0.54% Mn, 0.10% Ni, 2.45% Cr, 0.90% Mo, balance Fe.
d. Welding conditions:
Under an electric current of 1,400 A (DCRP) and voltage of 22 V, using a direct current electric source having a constant voltage characteristic, at the speed of 120 mm/min, one layer of the austenite stainless steel (corresponding to the Japanese Industrial Standard: JIS 347) was build-up-welded, a beautiful, smooth bead of the build-up-welded metal having a thickness of 5-6 mm being obtained.
The chemical composition of the build-up-welded metal is shown in Table 2.
Table 2______________________________________Chemical composition of thebuild-up-welded metal in Example 2(%)______________________________________C Si Mn Ni Cr Nb Mo Fe0.035 0.40 1.95 10.1 19.5 0.88 0.14 balance______________________________________
EXAMPLE 3
a. Flux:
After a mixture comprising 55% by weight of calcium fluoride, 30% of alumina, 2% of iron oxide, 5% of silica, 5% of manganese oxide and 3% of zirconium oxide is melted together, it is ground into powder after it has solidified.
b. Chemical composition of the band-like electrode (having a thickness of 0.4 mm and a width of 50 mm): 0.06% C, 0.35% Si, 0.40% Mn, 0.10% Ni, 14.0% Cr, balance Fe.
c. Chemical composition of the base metal: 0.20% C, 0.23% Si, 0.72% Mn, 0.13% Ni, 0.07% Cr, balance Fe.
d. Welding conditions:
Under an electric current of 900 A (DCRP) and voltage of 28 V using a direct current electric source having a constant voltage characteristic, at the speed of 120 mm/min, one layer of a martensite base stainless steel (corresponding to the Japanese Industrial Standard: JIS 410) was build-up-welded, a beautiful, smooth bead of the build-up-welded metal having a thickness of 4.5-5.5 mm being obtained.
The chemical composition of the build-up-welded metal is given in Table 3.
Table 3______________________________________Chemical composition of thebuild-up-welded metal(%)______________________________________C Si Mn Ni Cr Fe0.06 0.30 0.95 0.12 12.8 balance______________________________________
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A flux particularly adapted to the carrying out of a method for a build-up welding proposed by the present applicant essentially comprises, by weight, 50 to 90% of calcium fluoride and 10 to 40% of alumina with an addition of one or more compounds selected from the group consisting of 0.5 to 7% of iron oxide, 2 to 10% silica, 1 to 17% of manganese oxide and 2 to 10% of chrome oxide.
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FIELD OF THE INVENTION
[0001] The present invention concerns a laying-down system for building together with plant for the primal cutting-up of meat items, namely half carcasses of pigs. The invention also concerns a fully-automatic system for the primal cutting-up of meat items, namely half carcasses of pigs, and comprising a laying-down module, a vision-based detection system for the determination of relevant fix points on meat items, a calculation unit with interface for the controlling of a positioning module and a sawing module. Moreover, the invention concerns a method based on a vision system for primal cutting-up of meat items.
BACKGROUND OF THE INVENTION
[0002] The dividing-up of half pig carcasses is traditionally carried out by an operator placed at a conveyor belt on which the carcasses pass, in that he manually corrects (pulls/pushes) the half carcass in position for a saw (circular knife) which is disposed above the conveyor belt. With this method, use is made of an operator and a saw for each cut which is made in the half carcasses.
[0003] The way in which the correction of the half carcasses is typically carried out is that a line laser marker mounted on the individual saws irradiates the conveyor band immediately in front of the saw in an imaginary line through the blade of the saw, and the operator uses this laser beam in moving the half carcass manually so that this is sawn through in the desired place.
[0004] The above-mentioned method has several disadvantages. In the first place, the operator's work is monotonous and physically demanding, and operators who carry out this work are worn-out by the work after a relatively short period. Secondly, the positioning of the cut is based on the subjective judgment of the individual operator, so that the accuracy can fall with changing operators, inattention on the part of the operator, or if he has difficulty in maintaining the necessary concentration over longer periods of time. Thirdly, the definition of the correct knife positioning can change during the course of the production, which necessitates verbal communication of the changed requirements out to a number of operators, which involves possibilities of error.
[0005] Efforts have been made to automate the above-mentioned method, for example in DK B 161 656 there is disclosed a semi-automatic plant of the kind whereby an operator moves a position-provider coupled to a laser beam to the positions on the half carcass where he judges that the cuts shall be placed. When the laser beam irradiates the place of the cut, the operator activates an operating element, whereby the position of the position-provider is read into a control system. The positions of the cutting places are used to position the half carcasses and the subsequent saws, so that the different cuts are effected in accordance with the judgment of the operator. The publication also discloses a method for arranging the individual half carcasses so that their lengthways axes are positioned at right-angles to the feeding direction. With the said system, it is thus possible for human errors of judgment to be made in connection with the positioning which determines the cuts which are to be carried out in the half carcasses.
[0006] In DK T3 0 594 528, a system is disclosed by which, with the help of mechanical measuring of the half carcasses, it can carry out a tri-partition of these (ham and fore-end cuts). The arranging of the half carcasses to the correct angle takes place in connection with the measuring of fix points in the pig carcass, in that this is drawn over the surface of the conveyor by means of the mechanical measuring means.
[0007] The above-mentioned methods are based either on manual or mechanical localization of the fix points which form the starting point for the cutting-up positions.
[0008] DK B1 167 462 discloses a vision system for the determination of said fix points on the half of an animal carcass, said vision system being coupled to a computer for the implementation of picture analysis which, after the determination of the position of fix points in a manner which is not specified, is said to send control signals to mechanisms which are not further described, and which on the basis of the positioning of the fix points carry out the arranging of the carcass and of the system's tools for the cutting-up of said carcass.
[0009] However, several different patents and patent applications are to be found which deal with actual vision analyses of meat products, partly with the view of classifying meat products, e.g. for determining the market value, and partly to be able to determine the position of certain structures. Among these there are two German publications, DE C2 41 31 556 and DE A1 41 09 345, to which reference is made when, in connection with the present invention application, vision analysis/determination of fix points on half carcasses is discussed. The precondition for the present invention is thus that the position of the fix points on half carcasses, which are used as starting point for the determination of the individual cuts, takes place by means of said vision system. The vision system comprises a video camera which takes a picture of the half carcass while this passes under the camera on a conveyor. The camera is coupled to a computer, which with specially-developed software recognizes the contours and inner structure of the half carcass, such as e.g. vertebrae in the spine and the pubis. Hereafter, with great accuracy the computer calculates the positions of the individual fix points in relation to a given zero line. By means of the computer together with suitable interface and actuators, the positioning of the fix points in relation to the zero line can subsequently be used for effecting mutual positioning of the half carcasses/saws with starting point in a beforehand desired positioning of the cuts in relation to said positioning of said fix points. The positioning can take place either by effecting a displacement of the saws (saw blades) in the lateral direction, still with the blades arranged parallel with the transport direction, and/or by using conveyor plant which can be displaced in the transverse direction by means of actuators.
[0010] The above-mentioned method and system is particularly suitable for use when an ordinary “industrial cut” is to be made (double cut where the fore-end and hams are separated from the central piece) at right-angles to the lengthways direction of the carcass, where the half carcasses are transported with the lengthways direction arranged at right-angles to the direction of transport, and where the parting cuts are placed in relation to the positions of the fix points by positioning of the half carcasses on sideways-displaceable conveyors, and positioning of the saws in the sideways direction.
[0011] If only a ham cut is to be carried out, which is sometimes known as a “Belgian cut”, also in the following, it will not be possible to use the above-mentioned method for automatic parting of the carcass, in that a Belgian cut is effected as an inclined cut in relation to the lengthways direction of the carcass, though still in relation to the positioning of the relevant fix point on the half carcass. When carrying out the parting with this type of cut, it has thus hitherto been necessary to effect the cutting manually with manually-operated saws with laser marking of the positioning of the cut, in that the cut which is carried out here shall extend at an angle in relation to the direction of transport. Neither is the above-mentioned method particularly suitable when it is preferred to carry out an optimized industrial cut, which often involves the placing of the cuts at an angle which deviates from right-angles to the lengthways direction of the carcass.
[0012] These problems are further aggravated when the production rate has to be increased. Typically, a slaughter line as described above will be able to handle 3-500 carcasses an hour, but it is desirable to be able to have an automatic cutting system which can handle 1000-1200 carcasses or more per hours. One of the key problems in increasing the production rate is that the compromise between cutting quality and speed appears to be somewhere in the vicinity of about 0.4 meters per second for cutting speed. At higher cutting speeds a number of undesirable effects appear, such as crushing of bones whereby bone splinters can contaminate the finished meat items, the cut surfaces can be covered by fat which has been pulled out from the meat item to be cut, which is undesirable in the quality of the finished meat products. Furthermore, the carcasses can be forced into a undesirable position in relation to the rest of the cutting proceedings when the saws engage larger bones and the like. Furthermore, in order to be able to adjust the saws in relation to fixed points on the meat in order to carry out the desired cuts, it is advantageous that the saws come to a stand-still such that the gyroscopic effect of the saws will not have any influence on the positioning. By increasing the production speed it can be difficult to provide the necessary period of rest time for the saws in order to adjust them precisely.
SUMMARY OF THE INVENTION
[0013] For solving the above-mentioned problems and especially for providing a system with a high capacity a system is disclosed for primal cutting-up of meat items, comprising a laying-down module, a vision detection system for the relevant fix points on meat items, a calculation unit with an interface for the controlling of a positioning module controlling a saw module, wherein:
[0014] a) the laying down-module comprises two overlapping conveyors having substantially the same transport direction and transport plane:
[0015] 1) a first conveyor comprising spaced tracks which are synchronously driven, and on which conveyor substantially U-shaped laying-down fixtures are arranged, and that the lowest points on at least two outermost of said fixtures are lying on a line oriented substantially at right-angles to the transport direction, and that at least a section of said first conveyor overlapping a second conveyor has a downward sloping section in the transport direction;
[0016] 2) and a second conveyor comprising spaced tracks arranged in the spaces between the tracks of said first conveyor, such that meat items placed in the U-shaped laying down fixtures on the sloping portion of said first conveyor will engage the tracks of said second conveyor and thereby be transported in the transport direction by said second conveyor.
[0017] b) the vision detection system comprises a camera which camera is connected with a computer with vision detection software, for determining fix points on the meat items passing the camera, which fix points are related to a zero line in relation to which the positioning module controls the saw module;
[0018] c) the fix points relation to the zero line is fed to a calculating unit, which calculating unit feeds input to a control unit controlling actuators, which actuators adjusts the saw modules vertical and horizontal position in relation to the input of the fix points of the meat items.
[0019] The systems as set out above does not require the carcass to have any stops from it is positioned in the U-shaped laying-down fixtures until they are cut in the sawing station. This in itself provides for increased production. Furthermore, due to the vision detection system identifying fixed points on the meat items such that any tolerances in the placing of the meat items in the U-shaped laying-down fixtures will be compensated by moving the saw instead of moving the carcasses. The transport time from the vision detection system to the saws is used in order to adjust the saws according to the data collected by the vision detection system. In this manner it is possible to greatly increase the production as all movements are kept to a minimum, especially on the heavy items which is, in this case, the meat item. Furthermore, as the meat item tends to be slippery, a rapid movement of the U-shaped laying-down fixtures in a lateral direction relative to the transport direction can cause the U-shaped laying-down modules to conduct the required movement, but sliding on the meat item such that the meat items does not move the same increments as required by the vision detection system, whereby an optimum cut is not achieved.
[0020] By moving the saws, which are completely independent of the meat items, it can be assured that an optimum cut will be achieved at all times in that the meat items are not moved except from in the transport direction from the time when the vision detection system detects the fixed points and does the calculation for placing the saws in the most optimum position in order to achieve the desired cuts
[0021] With the U-shaped laying-down fixtures, it is hereby achieved that the meat item/half carcass, after receipt by being successively fed forwards by the suspension conveyor, is placed in the low points of the fixtures, so that before the laying-down on the laying-down conveyor, these are arranged so that the half carcass in the under-supporting points defined by the low points of the two outermost fixtures is lying in a line which is arranged substantially at right-angles to the transport direction of the laying-down conveyor. There is hereby achieved a very uniform positioning and orientation of the transported carcasses, which by the vertical downwards-directed displacement of the fixtures subsequently places the half carcasses in this position on the laying-down conveyor for transport in the further cutting-up process. Moreover, it will not always be certain that the low point in the centermost fixture lies on the line which can be drawn between the two outermost fixtures.
[0022] Moreover, with this construction of the laying-down module, it will be possible to place the two outermost fixtures in a manner in which they are displaced from each other, so that the line between the low points of these fixtures deviates from right-angles to the transport direction of the laying-down conveyor. With this embodiment, the changing of this angle can take place only by constructional intervention, which hardly satisfies the demands concerning flexibility which are placed in connection with the primal cutting-up of meat items, namely in the carrying out of optimized industrial primal cutting up.
[0023] The subsequent sub-claims 2-7 disclose how said demands for speed and flexibility can be increased.
[0024] In a further advantageous embodiment is disclosed a system wherein the U-shaped laying down fixtures are provided with adjustment means for carrying out a relatively horizontal displacement of the substantially U-shaped laying-down fixtures in the spaces between the tracks of said second conveyor, so that the line between the lowest points of the laying-down fixtures and the transport direction of the conveyors forms an angle which can deviate from right-angles relative to the transport direction of the laying down conveyor.
[0025] In practice, this possibility of fine adjustment will be sufficient in connection with the carrying out of optimized industrial cuts, where most often there is a need only to achieve smaller relative displacements between the low points of the two outermost fixtures in order for the line between these to form an angle which deviates from right-angles to the transport direction of the laying-down conveyor.
[0026] In a still further preferred embodiment a system wherein an angling-out mechanism driven by a drive mechanism is provided on a frame of the system, by means of which the laying down fixtures are horizontally displaceable between an angled-out position where lowest points of the laying down fixtures are on a line at a right angle to the transport direction of the first conveyor, and an angled-out where said line forms another, pre-selected angle in relation to the transport direction.
[0027] On the other hand, if a subsequent ham cut (“Belgian cut”) is to be made, it will be necessary to place the fixtures, possibly with the adjustment means as described above in conjunction with the angling-out mechanism, whereby the laying-down fixtures are relatively displaced by an actual movement each time a meat item is received from the suspension conveyor, so that the low points of the two outermost fixtures are lying on a line which forms a predetermined angle in relation to the transport direction, so that the carcasses in this position are placed on the laying-down conveyor at an inclined angle, and in this position are transported further by the laying-down conveyor to subsequent steps in the process.
[0028] Furthermore, in a still further advantageous embodiment the said saw module comprises at least two independently controllable saws which saws by means of actuators may be horizontally and vertically adjusted with respect to fix points on the meat items determined by the vision detection system, and a third conveyor positioned under the saws, for transporting the meat items through the saw module.
[0029] In a further advantageous embodiment of the invention the third conveyor position under the saw comprises one or more parallel tracks substantially parallel to said first and second conveyors and that the tracks are of the pattern chain type having cone tops. By providing the third conveyor with the so-called cone tops or the like it is assured that a good grip, i.e. a high friction, will be provided between the meat items being transported on the conveyor and the conveyor itself, whereby the sliding will be avoided and, furthermore, the high production rate can be attained.
[0030] In a further advantageous embodiment each track of said third conveyor may be elevated or lowered separately from a neighboring track. This is again an important feature of the system in that by being able to elevate a track and thereby bringing the carcass closer to the saw the actual transport time of the saw can be minimized and, furthermore, it can easily by achieved that it is assured that the saw goes all the way through the meat item and thereby a clean cut is achieved.
[0031] It will be obvious that the laying-down module will be able to be arranged for receiving half carcasses for primal cutting-up which are transported successively in pairs on the suspension conveyor.
[0032] The advantages of the system should be obvious, i.e. providing such a system includes a laying-down module with all of the associated advantages and there is hereby achieved a fully-automatic system for primal parting of meat items, which practically speaking enables automatically-implemented parting of meat items in accordance with any desired cut positioning, and which also allows continuous optimization of the cut positioning, not only in relation to average considerations concerning the determination of fix points on a series of transported meat items/carcasses, but optimization in relation to fix-point determinations carried out on each individual meat item, and subsequent placing of the ideal cut line on the basis of empirical ideal cut lines for a meat item with size and fix-point placing determined by the vision detection system.
[0033] The invention is also directed towards a method based on a vision detection system for primal parting of meat items comprising the following steps:
[0034] a) the receiving of meat items fed successively onto a laying-down module by two overlapping conveyors having substantially the same transport direction and transport plane:
[0035] 1) a first conveyor comprising spaced tracks which are synchronously driven, and on which conveyor substantially U-shaped laying-down fixtures are arranged, and that the lowest points on at least two outermost of said fixtures are lying on a line oriented substantially at right-angles to the transport direction, and that at least a section of said first conveyor overlapping a second conveyor has a downward sloping section in the transport direction;
[0036] 2) and a second conveyor comprising spaced tracks arranged in the spaces between the tracks of said first conveyor, such that meat items placed in the U-shaped laying down fixtures on the sloping portion of said first conveyor will engage the tracks of said second conveyor and thereby be transported in the transport direction by said second conveyor by a suspension conveyor with lengthways axes of the meat items oriented substantially at right-angles to a transport directions of the laying-down module;
[0037] b) the positioning of the meat items at the laying-down and angle positioning module meat items positioned with the lengthways axes to a preferred angle in relation to a right-angle with respect to the transport direction of the laying-down conveyor;
[0038] c) feeding the meat items on the laying-down module in the transport direction toward to a vision detection system comprising a camera which camera is connected with a computer with vision detection software, for determining fix points on the meat items passing the camera, which fix points are related to a zero line in relation to which the positioning module controls the saw module;
[0039] d) taking pictures of the meat items with the vision detection system for the determination of fixed points on said meat items;
[0040] e) feeding the fixed points position in relation to a zero line to a calculating unit, which calculating unit feeds input to a control unit controlling actuators, which actuators adjusts the saw modules vertical and horizontal position in relation to the input of the fix points of the meat items;
[0041] f) feeding of the meat items to a third conveyor at a saw module and
[0042] g) the parting of the meat items by cutting-up with the saw during transport of the meat items by said third conveyor of the saw module.
[0043] The method according to the invention is based on the use of the above-mentioned known vision system for detection of the fix points which form the basis for the positioning of the parting cuts, no matter whether these are standard industrial cuts or ham cuts (“Belgian cuts”), or other special cuts such as optimized industrial cuts used in the primal cutting-up, so that manual handling in the cutting-up process is avoided, and also so that human errors in connection with the placing of the cuts are eliminated. In this connection it should be mentioned that the angles V 1 and V 2 can assume the value zero (typically with industrial parting cuts).
[0044] Further advantageous embodiments comprise that the meat items are transported successively in pairs on a suspension conveyor to the laying-down module, and wherein the taking of pictures by the vision system for determination of the fixed points are taken of at least a first of the two meat items of the pairs.
[0045] And in a still further advantageous embodiment the meat items are half carcasses.
[0046] With the invention, use is thus made of the fact that the calculation of the positioning of the fix point in relation to the zero line can be carried out no matter whether the half carcasses arrive at the picture-taking section with the lengthways direction arranged at right-angles to the transport direction, or at an angle which deviates from right-angles.
[0047] Whether the half carcasses arrive at the picture-taking section with lengthways direction at right-angles to the direction of transport, or at an angle which deviates from this, is thus determined on the basis of how the primal cutting-up of the half carcasses is to be carried out by the saw module, the blades of which are oriented parallel with the transport direction. If, for example, a traditional industrial cut is to be effected, where the half carcass is divided with a fore-end cut and/or a rear-end cut, it is normally preferred that the half carcass is conveyed into the cutting plant (and herewith to the picture-taking section) with the lengthways direction arranged at right-angles to the transport direction, after which said cut is effected in relation to the pubis and especially the armpit, typically so that upon passage of the positioning module, the half carcass is positioned in relation to the cutting line of the ham saw, with starting point in the positioning of the pubis, and the cut line of the saw system's fore-end saw is lined up in relation to the position of the armpit.
[0048] If a “Belgian cut” (ham cut) is to be effected, it is preferred that the half carcass be conveyed into the cutting plant (and herewith to the picture-taking section) with lengthways direction oriented at an inclined angle in relation to the transport direction, after which the cut is effected solely in relation to the position of the pubis, which is made possible by the laying-down module according to the invention.
[0049] With the combination between the use of a vision-controlled positioning and cutting-up system and the laying-down module according to the invention, with the invention there is achieved a fully-automatic and very precise cutting-up of half carcasses which shall be parted with Belgian cuts (ham cuts) and optimized industrial cuts, in that the half carcasses are laid down on the laying-down conveyor with the lengthways direction of the carcass at a pre-selected angle in relation to the transport direction, corresponding to the preferred angle with which the cutting-up with Belgian cuts, or optimized industrial cuts, is carried out with a cutting system which has saw blades arranged parallel with the transport direction.
BRIEF DESCRIPTION OF THE DRAWINGS
[0050] In the following, the invention is explained in more detail with reference to the drawing, where
[0051] [0051]FIG. 1 is a schematic plan view of a fully-automatic vision-controlled cutting-up system with laying-down modules according to the invention, and comprising an angle-positioning system,
[0052] [0052]FIG. 2 is a detail view of the procedure of laying-down half carcasses in the laying-down module,
[0053] [0053]FIGS. 3 a and 3 b are detail side views of the laying-down module according to the invention,
[0054] [0054]FIG. 4 is a plan view of FIG. 5 showing the angling-out mechanism,
[0055] [0055]FIG. 5 is a schematic plan view of the system shown in FIG. 1 in the carrying out of Belgian cuts,
[0056] [0056]FIG. 6 is the same as FIG. 5, but where industrial cuts are carried out,
[0057] [0057]FIG. 7 shows a schematic view of a preferred system, and
[0058] [0058]FIG. 8 shows a schematic view of a cross section of a saw module.
DETAILED DESCRIPTION
[0059] [0059]FIG. 1 shows a schematic view of an embodiment of a fully-automatic cutting-up system for primal parting of half carcasses of pigs. The system is intended for adjustment for carrying out practically all types of known, desired primal parting cuts.
[0060] In the embodiment shown, the cutting-up system comprises a laying-down module 2 , a vision system 4 (with associated calculation unit and interface for actuators which are not shown in detail, in that this is considered to be known technique), placed over a positioning module 6 , and a saw module 8 . Above the laying-down module 2 , there extends a laying-down conveyor 10 (cf. FIG. 2) for the successive delivery of related half carcasses 12 to the laying-down module 2 .
[0061] As indicated in FIG. 1, and as shown clearly in FIGS. 2, 3A, 3 B and 4 , the laying-down module 2 comprises a set of substantially U-shaped laying-down fixtures 14 which are laterally reversed in relation to each other. As will appear from FIGS. 3A and 3B, the fixtures 14 are suspended on a vertically-displaceable base frame 16 between two outer positions, where the upper sides of the fixtures are lying at a level above the laying-down module's conveyor 18 , and respectively where the uppermost parts of the fixtures 14 are lying at a level below the surface of the conveyor belt.
[0062] As will appear from FIG. 1, the conveyor 18 is divided into four tracks/belts 20 , 22 , 24 , 26 , which are mutually spaced apart by the spaces 21 , 23 , 25 . The breadth of the tracks/belts is determined respectively by a preferred total belt breadth of the conveyor 18 , and by the distance between the individual hoops in the fixtures 14 . The individual belts are moved in a synchronous manner in the transport direction of the conveyor. The transport direction of the conveyor and the transport direction of the whole of the cutting-up system is indicated by the arrow 28 in FIG. 1.
[0063] The fixtures 14 are also connected to an angling-out mechanism 30 cf. FIG. 4 mounted on a base frame 16 . The angling-out mechanism is connected with the fixtures 14 via rod connections 32 with pivot link 34 , which in turn stand in connection with an actuator in the form of a displaceable piston 36 , the displacement of which causes a mutually reversed displacement in the lateral direction of the anchoring points for the U-shaped fixtures, so that the line 40 which is described by the low points 38 of the U-shaped fixtures 14 is displaced from a direction at right-angles to the transport direction 28 of the conveyor, so that this line forms an angle V 1 or V 2 which deviates from right-angles. The angling-out mechanism also comprises adjustment mechanisms 42 for fine adjustment of the angular displacement.
[0064] It should be noted that the angling-out mechanism 30 can be completely omitted, providing that the system is intended for use only for the carrying out of industrial parting cuts or optimized industrial cuts, where the meat items/carcasses 12 are laid down on the conveyor 18 in a position where the low points 38 of the outermost U-shaped hoops in the laying-down fixtures 14 are lying on a line at right-angles to the transport direction 28 of the conveyor, possibly with a small angular deviation adjusted by means of the adjustment mechanism 42 , for carrying out an optimized industrial cut. If it is desired to effect industrial parting cuts only, the adjustment mechanism 42 can also be omitted.
[0065] In FIG. 2 it is shown how the half carcasses 12 are laid down on the laying-down module 2 from a laying-down conveyor 10 . The half carcasses 12 are laid down on the raised fixtures 14 which are disposed in the receiving position above the belts 20 , 22 , 24 , 26 of the conveyor. The half carcasses 12 are hooked off the conveyor 10 , which is determined by the length of the half carcasses. Moreover, the half carcasses are transported in pairs to and subsequently laid down in the fixtures 14 .
[0066] The positioning module 6 comprises two conveyors 44 , 46 placed in extension of each other, where above the conveyor 44 closest to the laying-down module 2 there is placed a vision camera 4 . By means of a known technique, the conveyors 44 , 46 are displaceable in the sideways direction by not-shown actuators, as indicated by the arrows 48 , 50 . The actuators for the sideways displacement of the conveyors 44 , 46 are controlled by a computer (not shown).
[0067] The saw module 8 comprises a ham saw 52 and a sideways-displaceable fore-end saw 54 . The saw blades are oriented parallel with the transport direction 28 in the cutting plant, and have an extent so that the edges extend a distance down below the surface of the conveyor belt 56 , 58 of the saw module.
[0068] The fully-automatic primal cutting-up system's laying-down module 2 , positioning system 6 , vision system 4 and saw module 8 , are all connected to a computer (not shown) which, on the basis of the vision system's picture analysis, calculates the actual positioning of the fix points for the positioning of the parting cuts for the desired cutting-up, in relation to a zero line. Hereafter, the half carcasses 12 are moved in by sideways displacement of the positioning conveyor's belts 44 , 46 , preferably so that the placing of the ham cut, which is determined by the position of the pubis, is positioned in relation to the saw-blade line 60 for the ham saw 52 , after which the fore-end saw is displaced in the sideways direction in relation to the desired placing of the fore-end parting cut, which is typically determined on the basis of the position of the ulna. Hereafter, the half carcasses are transferred through the saw module during the carrying out of the parting cuts.
[0069] In connection with fully-automatic parting with “Belgian cuts”, which comprises only a single inclined ham cut in between the groin of the carcass and across the carcass towards the ham, it will be necessary to use the angling-out mechanism 30 , so that the lengthways direction of the carcass is arranged at an angle V 2 in relation to the direction of transport through the saw line 60 for the ham saw 52 of the saw module.
[0070] However, a certain angling-out of the half carcasses 12 is also required, though less than the angling-out with the “Belgian cut”, when carrying out a traditional industrial parting cut, which comprises two cuts, i.e. the ham cut and the fore-end cut along the saw lines 60 , 62 . The changeover for this purpose can quickly be carried out by means of the angle adjustment mechanism 42 .
[0071] In FIGS. 5A to 5 H it is shown how the parting of half carcasses 12 with the “Belgian cut” is carried out with a fully-automatic cutting system. In FIG. 5A, a first pair of half carcasses 12 arrive at the laying-down module 2 in the fixtures 14 (not shown for the sake of clarity), after which an angling-out (FIG. 5B) is carried out by the angling-out mechanism 30 (FIG. 4) and a subsequent lowering of the fixtures 14 (cf. FIG. 3B). The first of the two half carcasses 12 is fed in the transport direction 28 on to the positioning conveyor 44 (FIG. 5C), where the vision system 4 takes a picture of the half carcass, and this is sent to a picture analysis unit (not shown) which determines relevant fix points on the carcass for the positioning of the parting cuts, after which (FIG. 5D) the half carcass 12 is transferred to the positioning conveyor 46 where a positioning of the carcass 12 is carried out in relation to the saw line 60 for the ham saw 52 . At the same time, the second half carcass 12 is fed in under the vision system 4 for the taking of a picture. Hereafter, the foremost positioned half carcass 12 is fed (FIG. 5E) forwards towards the saw module's saw 52 , and the next pair of half carcasses 12 ′ are received in the laying-down module 2 , and the sawing of the foremost half carcass is started (FIG. 5F) at the same time that the positioning of the second half carcass is effected by the sideways displaceable conveyor 46 in the positioning module 6 , and the next pair of half carcasses 12 ′ are angled-out in the laying-down module 2 . After positioning of the second half carcass 12 , this is fed into the saw module 8 (FIG. 5G) where sawing-up is commenced along the line 60 . At the same time, the foremost half carcass 12 ′ of the next pair of half carcasses is fed to the vision system 4 on the conveyor 44 for the taking of a picture. With the sawing of the rearmost half carcass 12 (FIG. 5H) of the first pair of half carcasses 12 , the foremost half carcass 12 ′ of the second pair of half carcasses 12 ′ is positioned by the sideways displaceable conveyor 46 at the same time that the second half carcass is photographed by the vision system on the conveyor 44 . Hereafter, the procedures as described above are repeated.
[0072] FIGS. 6 A- 6 G show fully-automatic cutting-up when carrying out a traditional industrial cut, without angle positioning at the laying-down module 2 , but where in the same manner as described above there is carried out a fix-point determination by the vision system 4 (FIG. 6B), a subsequent positioning in the sideways direction (FIG. 6C) for the cut line 60 for the ham saw 52 , and a simultaneous positioning of the fore-end saw 54 , followed by the feeding of the foremost half carcass 12 to the saw module 8 (FIG. 6D, positioning of the second half carcass 12 (FIG. 6E), and at the same time as the arrival of the next pair of half carcasses 12 ″ in the laying-down module 2 . The only difference in the implementation of the sequences for the industrial cut is that here there is also carried out a positioning of the cut line 62 for the fore-end saw 54 on the basis of a further fix point determined by the vision system, and that as opposed to the implementation of the ham cut, use is made of the fore-end saw.
[0073] There is thus disclosed a fully-automatic primal cutting system for carrying out “Belgian cuts” and ordinary industrial cuts, possibly effected in an angle-positioned implementation as a so-called optimized industrial cut.
[0074] In FIG. 7 is illustrated a system for primal cutting-up of meat items, where rather high production targets can be achieved.
[0075] At a target capacity of 1200 pigs an hour, a pig shall be positioned every third second. Turning now to FIG. 7, the carcasses which are already divided in two, are brought to the first conveyor 63 and positioned in the U-shaped laying-down fixtures 14 attached to the first conveyor 63 .
[0076] The first conveyor 63 comprises a number of spaced parallel tracks which are synchronously driven. Furthermore, the first conveyor 63 is overlapping a second conveyor 64 . In the overlap the first conveyor has a downwardly sloping section such that the carcasses being held in the U-shaped fixtures 14 will be transferred to the second conveyor 64 as the fixtures 14 are transported below the level of the second conveyor 64 such that the second conveyor will engage the carcasses and provide for the further transport.
[0077] As a carcass is transferred on the second conveyor 64 it will be transported past a vision detection system comprising a camera 65 . The camera will send an image to a calculating unit (not shown) which will have an optical recognition system software such that particular fixed points on the meat items have been pre-programmed into the system such that when the camera forwards the picture of the meat item passing on the conveyor 64 , characteristic fixed points on the meat items can be determined. The calculating unit thereafter forwards this information to actuators (not shown) which actuators adjust the saw module 66 . The arrow 67 indicates the cutting direction, i.e. the direction of movement of the saw module 66 . Connected to the saw module is also a third conveyor 68 , which will be further explained with reference to FIG. 8.
[0078] It should be noted that only a limited amount of U-shaped laying-down fixtures 14 has been indicated on the first conveyor, but in practice, fixtures 14 will be arranged as closely as possible on the first conveyor in order to achieve the productivity aimed at.
[0079] Tests have shown that the downward movement 67 of the saw module is in the vicinity of 200 mm, where the maximum cutting speed in order to achieve an acceptable quality of the cut and in order to avoid problems with bone crushing, fat distortion etc. is 400 mm per second. This leaves the time for performing the cut through the meat item to be approximately half a second, and the necessary time for pulling the saw back up is about 0.25 second.
[0080] The vision recognition analysis and the calculations as well as the adjustment of the actuators requires 0.25 second. Furthermore, it is assumed that the transport speed will be 1000 mm per second and that the distance a carcass has to travel from it is delivered till a new one is placed is approximately 700 mm. This leaves a transport time of 0.7 second for the entire carcass through the system for primal cutting-up as disclosed above.
[0081] In order to have enough time to position the saw module, the transport time minus the vision analysis time leaves 0.45 second for positioning of the saw module.
[0082] Adding all the separate steps a cycles time for each carcass is approximately 1.2 seconds. This, in turn, leaves a theoretical capacity for the systems as described above at 1500 whole pigs per hour. As the target was 1200 pigs an hour, there is a little slack in the system. At the capacity of 1200 pigs an hour, a pig needs to be placed every third second in the U-shaped positioning fixtures 14 . This can be achieved with a system as described above. Assuming that the normal distance between pigs is 1500 mm, which is traditional today, the speed of the first conveyor shall be 0.5 meters per second. This speed is so relatively low compared to what is customary that it is possible to have a variable speed, for example by means of a frequency converter coupled to the driving means of the first conveyor such that the speed when the carcass is positioned in the U-shaped fixture can be lowered, whereby a higher precision can be achieved such that less adjustment of the saw module is necessary.
[0083] In FIG. 8 is illustrated a cross section through the saw module comprising saws 66 and a third conveyor 68 . The saws 66 can be manipulated by means of actuators controlled by the calculating unit reacting in response to information received via the vision detection system in a vertical direction 67 and a horizontal direction 69 generally perpendicular to the transport direction of the first, second and third conveyor.
[0084] The third conveyor 68 is, like the other two conveyors in the system, built up of a number of parallel, separate tracks. In the conveyor 68 of the saw module each track can be elevated or lowered in relation to any other track of the third conveyor such that a height difference can be created between two neighboring tracks. In this manner it can be achieved that two tracks 70 , 71 are elevated and a third track 72 is lowered such that the cutting by the saw 66 can be further improved and that it can be assured that a complete cut throughout the meat items by the saw 66 can be achieved.
[0085] As the vision detection system is stationary in respect to the third conveyor 68 , information regarding the fixed points, which is already fed to the calculating unit, will also be used in controlling which tracks 70 - 72 of the conveyor 68 will be elevated, respectively lowered, in order to create a gap underneath the saw 66 which is to perform the cut.
[0086] Although the invention has been described with respect to a number of specific embodiments the invention is only to be limited by the scope of the appended claims.
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In the primal cutting-up of half carcasses of animals ( 12 ), vision systems are known whereby the determination of one or more fix points on the carcasses takes place, and where on the basis of the position of these points a visualization of the ideal cut line is effected. But the primal cutting-up of carcasses ( 12 ) has hitherto been carried out with manually-operated saws on the basis of operator evaluation. However, the use of manually-operated saws involves the possibility of deviations in relation to the ideal cut line, and the manual work is very monotonous and fatiguing for the operators.
There is thus disclosed a system as well as a laying-down module ( 2 ) and a vision-based system for automatic primal cutting-up of half carcasses, comprising a laying-down module with a laying-down conveyor ( 18 ), and a laying-down and angle-positioning module ( 6 ) with sideways displaceable conveyors for positioning of a relevant carcass ( 12 ) for sawing-up in a subsequent saw module ( 8 ), and a method for the execution of automatic primal cutting-up of meat items, namely half carcasses of animals.
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STATEMENT OF RELATED APPLICATIONS
[0001] This application claims foreign priority benefits under 35 USC 119(a)-(d) or (f), or 365(b) on German patent application number 10344239.1, filed on 23 Sep. 2003.
BACKGROUND OF THE INVENTION
[0002] 1. Technical Field
[0003] The invention relates to a method for determining atomic isotope masses in mass spectrometry, atomic isotope ratios being determined from molecular isotope ratios measured by means of an isotope mass spectrometer—ion correction, the determination of the atomic ratios being carried out by setting up and solving a system of equations which describes relationships between the atomic and the molecular ratios, and the system of equations having to have at least as many independent equations as there are atomic ratios.
[0004] 2. Prior Art
[0005] In gas isotope mass spectrometry, gas molecules which are composed of a plurality of different atoms are measured in most cases. In this case, the ratios between various molecular isotope masses are measured. Atomic isotope ratios are mentioned when the mass ratios of two isotopes of a specific atom are to be designated. On the other hand, molecular isotopolog ratios are mentioned when the mass ratios of specific isotopologs at the molecular level are designated.
[0006] The determination of molecular isotopolog ratios is usually less desired than the determination of atomic isotope ratios.
[0007] In order to determine the atomic ratios from the molecular isotopolog ratios, it is known to set up various equations which describe theoretical and empirical relationships between the respective ratios. These equations are then solved individually and in a complicated manner for the atomic ratios sought and under certain circumstances each individual equation is solved numerically. If, during a further isotope mass measurement, other atoms or molecules play a part, new equations have to be set up and these in turn have to be solved individually. These steps have to be carried out independently for each type of gas which is measured or is to be measured.
BRIEF SUMMARY OF THE INVENTION
[0008] It is therefore an object of the present invention to specify a method in which at least one drawback of the prior art is avoided, the intention being in particular for a flexible possible determination, less susceptible to error, of the atomic isotope ratio to be possible.
[0009] This object is achieved by a method of the type mentioned at the beginning in which the entire system of equations is linearized by means of suitable numerical methods in a first step, in particular by means of a Taylor expansion or similar method, and in which the linearized system of equations is subsequently solved as a whole without transforming the individual equations.
[0010] The method according to the invention can advantageously be applied to all gases, the addition of further ratios being simply possible.
[0011] In a further refinement of the invention, in order to standardize the measurements, molecular ratios are determined from standard values of atomic ratios—inverse ion correction, the same linearized system of equations being used both for the inverse ion correction and for the ion correction.
[0012] The invention is also directed to an apparatus for determining atomic isotope masses in a mass spectrometer, in particular a computer, having an input interface, a computing unit and an output interface, it being possible for data about molecular isotope ratios which can be measured by means of an isotope mass spectrometer to be transmitted to the computer unit via the input interface, it being possible for atomic isotope ratios to be determined from the data about molecular isotope ratios in accordance with a method described in the present invention, and it being possible for the atomic isotope ratios to be output via the output interface.
[0013] Finally, the invention is directed to a computer program for determining atomic isotope masses in mass spectrometry, one of the methods described in the present application being implemented in a program by means of a suitable programming language.
[0014] Further features of the present invention emerge from the appended claims and the following description of a practical exemplary embodiment
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0015] In order to explain the method according to the invention, in the following text, by using the example of CO 2 , the method used hitherto in the prior art will be compared with the method according to the invention. In this case, under I, first of all general relationships of the method of the prior art will be explained, under II the new method according to the invention will be presented, and under III exemplary calculations will be carried out by using practical data.
[heading-0016] I. General Relationships of the Conventional Method
[0017] In gas isotope mass spectrometry, measurements are often made on gas molecules which are composed of a number of different atoms. In each case, the ratios between different masses are measured on a molecular basis. However, the atomic isotope ratios are relevant to the end results and also the international standard and reference substances.
[heading-0018] 1. Ion Correction
[0019] In the measurement of CO 2 , for example, the ratios of the intensities of the mass 45 to the intensity of the mass 44 (R45) and of the intensities of the mass 46 to the intensity of the mass 44 (R46) are determined.
[0020] However, these molecular ratios are composed of the atomic ratios sought:
R 13{circumflex over (=)}((amount of 13 C) divided by (amount of 12 C)),
R 17{circumflex over (=)}((amount of 17 O) divided by (amount of 16 O)) and
R 18{circumflex over (=)}((amount of 18 O) divided by (amount of 16 O)).
[0021] In specific terms:
the mass 44 consists only of 12 C 16 O 2 , the mass 45 of 12 C 16 O 17 O, 13 C 16 O 2 , and 12 C 16 O 17 O, the mass 46 of 12 C 16 O 18 O, 13 C 17 O 16 O and 12 C 17 O 2 .
[0025] The masses 47 and 48 can likewise be composed of atomic ratios. The total frequency is, however, low, so that these masses are generally not measured.
[0026] It is easy to derive, and known from the literature, that:
R 45 =R 13+2* R 17
R 46=2* R 18+2* R 13* R 17 +R 17 2
[0027] In order to obtain the R13 and R18 sought (in rare cases also R17) from the known R45 and R46, information is obviously missing here. One remedy is provided by the following relationship being applied
R 17 =K*R 18 λ
[0028] This equation cannot be derived exactly but is at best semi-empirical. There is generally disagreement about the factors K and λ. K can also be calculated from the R18 and R17 of the international standard in accordance with
K = R17 Standard R18 Standard λ
[0029] However, R17 of the international standard is likewise not very accurately determined. In any case, the parameters are uncertain; the generally accepted parameters will probably still be revised frequently in the future.
[0030] These equations are they were transformed manually to form the equation
0=−3 K 2 ( R 18) 2λ +2 K R 45 R 18 λ +2 R 18 −R 46
with only one unknown; this is solved numerically, for example in accordance with a Newton-Raphson algorithm; this gives R18 and then R13 in accordance with
R 13 =R 45−2 K R 18 λ
[0032] For other parameters of the semi-empirical equation, the result is possibly completely different final formulae to be solved, for example for λ=0.5
R 18=0.5*( R 46−2 R 17 R 13 −R 17 2 )
2. Inverse Ion Correction
[0034] For the standardization, the first step in the data evaluation, it is necessary to convert the known or defined atomic ratios into the molecular ratios (inverse ion correction). This is carried out by insertion into the above system of equations, which means that different equations are used for ion correction and inverse ion correction. The disadvantage in this case, apart from the susceptibility of this procedure to error, is that possible changes, for example the introduction of further gases (see above), bring with them changes in both systems of equations.
[heading-0035] 3. Other Gases
[0036] For each gas, the above relationships must be and are derived separately and in a complicated manner. The disadvantage in the existing method is, in particular, the fact that for each type of gas the derivation of the final formula must be carried out independently, which is time-consuming and susceptible to error.
[0037] The method is also inflexible for one and the same gas, since any (parameter) changes in the initial equations must be made directly in the software source code in the case of a software implementation of the method. Furthermore, for the inverse ion correction, it is necessary to use a different system of equations from that of the ion correction, which is likewise time-consuming and susceptible to error.
[heading-0038] II. New Method
[heading-0039] 1. General Approach
[0040] With the general gas
A 1 n1 A 2 n2 A 3 n3 A 4 n4 . . .
where the A i are the individual elements, with i as a natural number (i∈IN), n i (i=0, 1 , 2, 3 . . . or i∈IN 0,) the chemical stoichiometric numbers, and m i (i∈IN) the mass of the lightest isotope of the element A i , it is true that:
0 = ∑ i = 1 i max n i R ( m i + 1 ) - R ( 1 + ∑ i = 1 i max n i m i )
0 = ∑ i = 1 i max n i R ( m i + 2 ) + ∑ i = 1 i max n i R ( m i + 1 ) ∑ j = 1 i max nj R ( m j + 1 ) + ∑ i = 1 i max Pos ( n i - 1 ) R ( m i + 1 ) 2 - R ( 2 + ∑ i = 1 i max n i m i )
0 = ∑ i = 1 i max n i R ( m i + 3 ) + ∑ i = 1 i max n i R ( m i + 2 ) ∑ j = 1 i max njR ( m j + 1 ) + ∑ i = 1 i max n i R ( m i + 1 ) ( ∑ j = i i max njR ( m j + 1 ) ∑ k = j i max njR ( m j + 1 ) ) + ∑ i = 1 i max Pos ( n i - 1 ) R ( m i + 1 ) 2 ∑ j = 1 i max n j R ( m j + 1 ) + ∑ i = 1 i max Pos ( n i - 2 ) R ( m i + 1 ) 3 - R ( 3 + ∑ i = 1 i max n i m i ) etc …
In this case, R(x) are the ratios of the mass x (atomic or molecular) divided by the mass of the main isotope.
The function Pos(x) is defined as
Pos ( x )=1 for x> 0
0 for x≦0
[0044] The system of equations is simpler for real cases than it appears, since most terms are either 0 or are so small that they may be disregarded without any loss of accuracy (example: one constituent of carbon is always 14C, but only in frequencies of 1e−10 of the main isotope, and can therefore be set equal to 0 without any loss of accuracy).
[0045] It is also entirely possible that, of the possible molecular masses or ratios, in spite of an adequate abundance (frequency), only a selection can be measured for metrological reasons.
[0046] In the general case, the system of equations is under-defined, possibly on account of the above restrictions, and is further supplemented with one or more equations of the form
0 =f[R ( m i +n ), R ( m i +m ), R ( m i +k ) . . . ]
where f can be any desired, general functional rule.
[0048] It is critical that the number of atomic ratios used in the system of equations must be at least as large as the number of independent equations.
[0049] Each of the equations of the system of equations must, furthermore, be continuous and capable of continuous differentiation
[0050] This system of equations can also be represented in a simplified manner in vector notation as
F ( {right arrow over (R mol, )} {right arrow over (R at, )})= 0
[0051] In accordance with the new method, this system of equations is now no longer transformed individually (that is to say newly each time for each type of gas, measured masses, etc,) into an equation to be solved numerically but is solved as a whole. This can be done by various methods.
[0052] Preference is given to a Newton or pseudo Newton method, for example Newton-Kantorowitsch. In this case, the effort on computation is quite low because of the fast iteration, and therefore the speed of the calculations is high.
[0053] Alternative methods are, for example, gradient methods or fixed point iterations.
[heading-0054] 2. Ion Correction
[0055] For the ion correction, the molecular ratios are known from the measurement.
F({right arrow over (R mol, )}{right arrow over (R at, )})
must therefore be sold for the atomic ratios. The first step consists in the linearisation of the general nonlinear system equations with the effect of a Taylor expansion around an initial vector {right arrow over (R at 0 )}
F ( R mol → , R at , → ) ≈ ⅆ F ⅆ R at , → * ( R at , → - R at 0 → ) + F ( R mol , → R at 0 → )
[0057] The initial vector is ideally but, because of the fast convergence of this method, not necessarily, close to the actual ratios. This can be expediently be achieved by the known elementary ratios of the standard being used as a starting point.
ⅆ F ⅆ R at , → ,
the derivative of the function with respect to the factor of the atomic ratios means that the system of equations is derived separately for each individual vector element. The result can be formulated most elegantly in matrix notation.
[0059] The formation of the derivatives can be carried out exactly in a few cases (if the system of equations consists only of polynomials, for example), but in the general case numerically or by using approximation values. Because of the generality of the approach, an arbitrary numerical method is recommended.
[0060] One expedient method is for a slope vector to be calculated for each vector element in accordance with the following formula:
δ F → δ R at , j = F ( R mol , → R at , i = j , → , [ R at , j ( 1 + δ ] ) ) - F ( R mol , → R at , i = j , → , [ R at , j ( 1 - δ ) ] ) 2 δ R at , j , j = 1 , 2 , 3 …
[0061] As can be seen immediately, the linearized form of the equation can also be written in matrix notation (what is known as the Jacobi matrix).
[0062] This linearized equation can be solved in accordance with the known Gauss algorithm; the solution is taken as an initial vector for the next iteration step.
[0063] If appropriate, it is possible to continue to use the derivative determined at first in the following iteration steps; the iteration proceeds faster if the derivative is determined anew each time.
[0064] Since this method then generally converges at least at the square of the convergence speed, for example 5 iteration steps are often adequate; however, a threshold value for the change between two successive iterations steps is worth recommending as a stop criterion for the convergence.
[heading-0065] 3. Inverse Ion Correction
[0066] One important advantage of the method according to the invention resides in the fact that, for the “inverse” ion correction (the calculation of the molecular ratios with given atomic ratios, necessary for the standardization), the same system of equations and the same algorithm as for the ion correction can be used. The system of equations merely has to be solved for the molecular ratios, not for the atomic ratios as in the case of the ion correction.
[0067] For the inverse ion correction, the number of equations is typically, but not necessarily, higher than the number of variables. In this case, one line which consists only of zeros is obtained in the matrix
ⅆ F ⅆ R at , → .
This line is then left out for the following calculations (see example).
III. Exemplary Calculation
[0070] In the following text, by using practical numerical values, the conventional and the new method are compared in exemplary calculations.
[heading-0071] 1. Conventional Method (Using the Example of CO 2 )
[0072] The system of equations for CO 2 , using the parameters K and k from J. Sandrock, A. Studley, J. M. Hayes, Anal. Chem 1985 (57), 1444-1448, is:
0 =R 13+2 *R 17 −R 45
0=0 *R 18+2 *R 13 *R 17 +R 17 2 −R 46
0 =K*R 18 λ −R 17 with K= 0.0099235 and λ=0.516
Inverse Ion Correction
[0074] The usual primary standard is VPDB (“Vienna PDB”: PDB for Pee Dee Belemite, a fossil found at the Pee Dee River; since this has recently no longer been available, the standard is now defined by the IAEA in Vienna (therefore “Vienna”)); for the CO 2 generated from this, the following atomic ratios can be applied:
R13 st =0.0112372
R17 st =0.000410850
R18 st =0.002088349
[0075] Substitution in the equations
R 45 std =R 13 std +2 *R 17 std
R 46 std =2 *R 18 std +2 *R 13 std *R 17 sdt +R 17 std 2
yields
R45 st =0.0120589
R46 st =0.0041861
Ion Correction
[0078] The starting point, as in the new method explained below, will be molecular ratios which are 10 parts per thousand above those of the standard, that is to say
R45 sa =0.012179489
R46 sa =0.4227961409e−2
[0079] For the ion correction, the system of equations must be transformed for this specific case; it follows that
0=−0.00029542755675( R 18) 1032 +20.0099235 R 45 R 18 0.516 +2 R 18− R 46
with only one unknown; this is solved numerically for R18, for example, in accordance with a Newton-Raphson algorithm. The individual steps in this algorithm will not be discussed here, since this is known in the prior art.
[0081] The result for R18 is R18=0.0021092068
[0082] R13 also results from the transformed system of equations, specifically as
R 13 =R 45−0.019847 *R 18 0.516
that is to say R13=0.001135356448
2. New Method (Using the Example of CO 2 )
[0085] In the case of CO 2 , according to the general approach:
A 1 =C; A 2 =O n 1 =1; n 2 =2 m 1 =12;m 2 =16
and thus, from the general system of equations explained above
0=1* R (12+1)+2* R (16+1)− R (1+12+2*16)
0=1* R( 12+2)+2* R ( R (16+2)+1* R (12+1)*(2* R (17))+0* R (12+1) 2 +1 *R (17+1) 2 −R (2+12+2*16)
[0090] From this, it then follows that
0 =R 13+2* R 17 −R 45
0=2* R 18+2* R 13* R 17 +R 17 2 −R 46
[0091] The third equation needed to solve this system of equations with two unknowns is taken from the literature, specifically
0 = K * R18 λ - R17 with K = 0.0099235 and λ = 0.516
[0092] These three equations and the atomic ratios for the standard are all that is needed.
[0093] Here, too, it will be assumed that the standard gas contains the same isotope ratios as the gas generated from VPDB
R13 st =0.0112372
R17 st =0.000410850
R18 st =0.002088349
Inverse Ion Correction
[0095] By using this, first of all the molecular ratios for the standard are calculated. Since there are 3 independent equations but only 2 unknowns, the system of equations is even over-defined.
[0096] The atomic ratios of the standard are known, the molecular ratios have to be calculated by means of linearisation.
[0097] As mentioned, the system of equations is
0 =R 13+2* R 17 −R 45
0=2* R 18+2* R 13* R 17 +R 17 2 −R 46
0 =K*R 18 −R 17 with K= 0.0099235 and λ=0.516
or
0=0.0112372+2*0.000410850 −R 45
0=2*0.002088349+2*0.0112372*0.000410850+0.0004108502 −R 46
0=0.516* R 18 0.0099235 −R 17
[0099] These equations are differentiated numerically in accordance with the above scheme with respect to an initial vector of the molecular ratios. As the initial vector of the molecular ratio, it is recommended to derive this from that from the atomic ratios
R45 0 =R13 st =0.0112372
R 46 0 =2* R 18 st =0.004176698
δ is assumed to be 1e−3 in this example.
[0101] As an example, differentiate the first equation with respect to R45
δ F → δ R45 = ( .8329372 e - 3 - .8104628 e - 3 .224744 e - 7 0 - 0 .224744 e - 7 0 - 0 .224744 e - 7 ) = ( 1 0 0 )
[0102] Differentiation with respect to R46 is carried out in an analogous way, the linearized form of the system of equations is then (in matrix form)
( - 1 0 0 - 1 0 0 ) * [ ( R45 st R46 st ) - ( 0.0112372 0.004176698 ) ] + ( 0.0008217 0.00219756484465 ) = ( 0 0 )
[0103] The third line of the matrix consists only of the zeros, and is therefore left out:
( - 1 0 0 - 1 ) * [ ( R45 st R46 st ) - ( 0.0112372 0.004176698 ) ] + ( 0.0008217 0.00219756484465 ) = ( 0 0 )
[0104] If this is solved in accordance with the Gauss algorithm, it follows that
R45 st =0.0120589
R 46 st =0.4186100405 e− 2
[0105] Since the original system of equations is already strictly linear with respect to R45 and R46, the final result already follows in the first iteration step.
[heading-0106] Ion Correction
[0107] According to a measurement listed by way of example, the measured molecular ratios are to be in each case 10 parts per thousand higher than the standard values, that is to say
R45 sa =0.012179489
R 46 sa =0.4227961409 e− 2
[0108] Using the initial values (here, as recommended above, the values known from the standard are used)
R13 sa,0 =0.0112372
R17 sa,0 =0.000410850
R18 sa,0 =0.002088349
[0109] The form of the system of equations linearized in accordance with the above rule is
( 1 2 0 0.0008217 .23296 e - 1 2 0 - 1 .1015149221 ) * [ ( 0.0112372 0.000410850 0.002088349 ) - ( R13 R17 R18 ) ] + ( .120589 e - 3 .4186100404 e - 4 .271 e - 10 ) = ( 0 0 0 )
[0110] The factor 0.271e−10 is different from zero only because of rounding errors.
[0111] Using this, the result of the first iteration is
R 13=0.1135355425 e− 1,
R 17=0.4129673746 e− 3,
R 18=0.2109207035 e− 2
[0112] Of the further iterations, only the final results are reproduced here:
[heading-0113] 2nd Iteration
R 13=0.1135356448 e− 1,
R 17=0.4129622625 e− 3,
R 18=0.2109206842 e− 2
3rd Iteration
R 13=0.1135356448 e− 1,
R 17=0.4129622624 e− 3,
R 18=0.2109206842 e− 2
[0115] Even after 3 iterations, in this example the final value has been reached within the context of the computing accuracy used here for R13 and R18 (no longer any changes between the last two iteration steps).
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A method for determining atomic isotope masses in mass spectrometry, atomic isotope ratios being determined from molecular isotope ratios measured by means of an isotope mass spectrometer—ion correction, the determination of the atomic ratios being carried out by setting up and solving a system of equations which describes relationships between the atomic and the molecular ratios, and the system of equations having to have at least as many independent equations as there are atomic ratios. The entire system of equations is linearized by means of suitable numerical methods in a first step, in particular by means of a Taylor expansion or similar method, and in which the linearized system of equations is subsequently solved as a whole without transforming the individual equations.
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The present invention relates generally to hair trimmers, and more particularly to hair trimmers configured for trimming beards and moustaches to obtain a neat and well-groomed appearance. Functionally, the present trimmer is designed to minimize arm strain resulting from use of the trimmer; to enable the user to have a relatively unobstructed view of the area being trimmed; and also to provide light to the area being trimmed. Structurally, the present hair trimmer includes: a rotating head that is configured to be rotated at an inclined angle with respect to the rest of the trimmer; a main body that extends generally linearly except for an offset portion near the upper end; and/or a light for illuminating the area being trimmed. While the majority of the following discussion relates to the trimming of beards and moustaches, it should be noted that many of the features of the present invention may also be applicable to other forms of trimmers or clippers, such as those used for cutting the hair upon the scalp, those used for shearing animals, those used for shaving a patient in preparation for surgery, etc.
BACKGROUND OF THE INVENTION
In order to obtain a neat and well-groomed appearance, a person wearing a beard and/or a moustache will normally wish to trim his facial hair occasionally. Presently, there are trimmers available which are combined with electric shavers, as well as stand alone electric beard/moustache trimmers. Commonly, these trimmers have a cutting head (in which one blade reciprocates against another) that is fixed in a single position and extends from the front of the unit. For cutting the hair to a uniform length, one may use an attachment comb that spaces the cutting head from the skin by a specified distance. Typically, it is suggested that the trimmers be used to cut the hair against the grain, i.e., opposite to the direction in which the hair naturally grows.
One problem with many currently available beard trimmers relates to the relationship between the cutting head and the handle (or main body) of the unit. Oftentimes the user must position his hand and arm in potentially uncomfortable or awkward positions in order to have the cutting head aligned in the desired position with the face and/or the neck. In addition to the potential discomfort, the positioning of the trimmer unit may place the body of the unit, the user's hand, or the user's arm (or possibly all three) directly in front of the area where the hair is being trimmed, all of which obstruct the user's view of the area being trimmed and make trimming more difficult. An unobstructed view is especially important when edging around the peripheries of the beard, moustache, and sideburns in order to create edge lines that are clean and crisp.
Another problem with many currently available trimmer units also relates to the user's lack of the ability to adequately see the area where the hair is being cut. Customarily, the light in a bathroom (where the majority of beard grooming most likely takes place) originates from an overhead light source. Once again, the user's hand and the trimmer unit can possibly hinder the user from obtaining an adequate view of the area being trimmed. In this instance, the trimmer unit and the user's hand may create shadows that prevent the area being trimmed from being adequately illuminated by the overhead light. This problem is magnified in the underchin area where the chin itself creates a shadow and reduces the visibility in this area.
Thus, in light of these problems, among others, a first object of the present invention is to provide an improved hair trimmer of a design that does not require the user to position his hand in a potentially uncomfortable or awkward manner.
A second object of the present invention is to provide an improved hair trimmer which is ergonomically designed to minimize potentially awkward hand positioning by including an offset portion near the top of the main body of the unit, which otherwise extends generally linearly to define a longitudinal axis.
Another object of the present invention is to provide an improved hair trimmer in which the user may select the alignment of the cutting surface so that his view of the area being trimmed is not obstructed by his hand or the trimmer body.
An additional object of the present invention is to provide an improved hair trimmer in which the cutting surface may be positioned at preselected orientations by rotating the blade housing with respect to the main body of the trimmer.
Another object of the present invention is to provide an improved hair trimmer with a rotatable blade housing that enables the user to place the cutting surface in a properly aligned position, while still being able to comfortably hold the main body of the trimmer.
An additional object of the present invention is to provide an improved hair trimmer that can be comfortably held by the user with his elbow in a relaxed position near his body while edging around the beard, moustache, and sideburns. The present invention is intended to permit the user to edge while the plane of the blades are held nearly perpendicular to the main longitudinal axis of the trimmer body, with this main longitudinal axis being positioned substantially vertically. In this manner, the user is holding the trimmer unit in a comfortable position with adequate visibility of the area being trimmed.
A related object of the present invention is to provide an improved hair trimmer that enables the user to hold the unit in a comfortable position while using the unit to cut the beard by stroking upwards under the chin and above the cheekbones, especially when the trimmer unit used without an attachment comb.
Still another object of the present invention is to provide an improved hair trimmer that is equipped with a light for illuminating the area where the hair is being trimmed.
An additional object of the present invention is to provide an improved hair trimmer that is equipped with both a light and a rotatable blade housing.
Yet another object of the present invention is to provide an improved hair trimmer in which the cutting surface is angled so that the user's hand and arm are placed in a more comfortable position when the trimmer is used to cut hair with the grain of hair growth. It has been found that a neater looking trimmed beard may be obtained by trimming the beard with the grain, contrary to the generally accepted practice of trimming the beard against the grain. While some conventional trimmers may be capable of trimming the hair with the grain, using a conventional trimmer for trimming with the grain generally results in some awkward hand and arm positioning because many conventional trimmers are primarily designed for trimming against the grain.
Although trimming the hair against the grain may result in each hair actually being trimmed to a uniform length, trimming with the grain results in the appearance that each hair is trimmed to a uniform length. This may be true, in part, because of the manner in which hair grows. While hair generally grows in one direction, there will be certain strands that grow with a more random orientation. When trimming against the grain, all of the strands of hair will be lifted and trimmed to substantially the same length. The hair will then settle back into its original state near the skin, with some hairs being out of alignment. These hairs will be angled in relation to the other hairs, and thus will appear to have been cut shorter or longer than the other hairs, although they have actually been cut to the same length as the other hairs. This phenomenon results in the beard having a somewhat ragged look.
In contrast, if the beard is cut with the grain, a neater and more even looking appearance can be obtained, even though each strand of hair has not actually been cut to exactly the same length. When cutting the beard with the grain, those strands of hair that are growing out of alignment (relative to the majority of the hair growth) are cut to a different than those strands that are aligned. In this manner, when the unaligned strands return to their original state, and are angled with respect to the majority of the strands in that area, all of the strands of hair will appear to have been cut to a uniform length, resulting in the desired neat and well-groomed look.
Still another object of the present invention is to provide an improved hair trimmer configured with internal components that enable the above objects to be realized.
These and other objects of the present invention are discussed or will be apparent from the following detailed description of the present invention.
BRIEF SUMMARY OF THE INVENTION
The above-listed objects are met or exceeded by the present hair trimmer, which includes a cutting surface that extends at an angle from a blade housing, and where the blade housing is rotatable with respect to the main body of the hair trimmer. Preferably, the main body of the trimmer includes an upper portion that is somewhat offset from the remainder of the main body. The interface between the blade housing and the main body of the trimmer is inclined with respect to the primary longitudinal axis of the trimmer so that when the blade housing is rotated, the cutting surface extends outwardly to predetermined angles (with respect to the primary longitudinal axis). These predetermined angles have been selected to provide maximum comfort with respect to hand and arm positioning, especially when cutting the beard with the grain of hair growth. These preselected angles also improve the visibility of the area being trimmed by placing the trimmer body and the user's hand and arm in areas that do not obstruct the view of the area being trimmed. Further improvement in visibility is obtained by the addition of a light near the cutting surface, where the light is used to illuminate the area about to be trimmed.
More specifically, the present invention provides a hair trimmer that includes a main body extending between an upper end portion and a lower end portion and further includes a front side and a rear side. The main body defines a primary longitudinal axis that extends substantially linearly between the upper end portion and the lower end portion, except for an offset portion located near the upper end portion. Alternatively, the offset portion may be omitted. A blade housing is rotatably attached to the upper end of the main body such that the blade housing is rotatable with respect to the main body. The blade housing is defined by an attached side and a free side that is located opposite to the attached side. An interface plane is defined between the main body and the blade housing. The interface plane extends at an interface angle that is oblique to the primary longitudinal axis. The present hair trimmer further includes a cutting mechanism that is seated upon the free side of the blade housing. The cutting mechanism includes a cutting surface for engaging and severing hair. As an additional feature, the present hair trimmer may be also equipped with a light for illuminating the area about to be trimmed. Furthermore, the present hair trimmer is also designed to be used, with the benefits as described, either with or without an attachment comb.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
A preferred embodiment of the present invention is described herein with reference to the drawings wherein:
FIG. 1 is an elevational side view of an embodiment of the present hair trimmer;
FIG. 1A is an elevational view of an alternative embodiment of the present hair trimmer
FIG. 2 is an elevational side view of an embodiment of the present hair trimmer with an attachment comb attached thereto, and where the blade housing is oriented so that the cutting surface of the blades is directed toward the front of the trimmer (i.e., towards the right-hand side of the figure);
FIG. 3 is an elevational side view similar to the view of FIG. 2 (including the optional attachment comb), except that the blade housing has been rotated 180° so that the cutting surface of the blades is now directed toward the rear of the trimmer (i.e., towards the left-hand side of the figure);
FIG. 4 is an elevational view of the front of an embodiment of the present hair trimmer, including the optional attachment comb, in which the blade housing is rotated so that the cutting surface is directed towards the front of the trimmer;
FIG. 5 is a partially cut-away view of an embodiment of the present hair trimmer;
FIG. 6 is an enlarged view of the portion of FIG. 5 indicated with letter A;
FIG. 7 is an enlarged cut-away view of the blade housing of FIG. 5;
FIG. 8 is a front view of the main body of an embodiment of the present hair trimmer, with the front side portion of the main body removed to show the internal components therein; and
FIG. 9 is a rear view of a portion of the main body of an embodiment of the present hair trimmer with the rear side portion removed to show the internal components therein.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to FIG. 1, an embodiment the present hair trimmer is generally designated 10, and includes three main components--a main body 12, a blade housing 14, and a cutting mechanism 16 (shown partially in hidden lines). Briefly, the blade housing 14 is configured to be rotated with respect to the main body 12, and defines an interface plane at the interface 18 between these two sections. The cutting mechanism 16 is a preferably a detachable sub-assembly of a stationary blade 20 and a reciprocating blade 22 (FIG. 7), in which the interaction of the cutting teeth of these two blades form a cutting surface 24 that can engage and sever the hair. The cutting surface 24 is defined as the area where the teeth of the reciprocating blade 22 overlap the teeth of the stationary blade 20, a configuration known to those of ordinary skill in the art. The cutting surface 24 is an area within the cutting plane 34, which is described below. An additional feature of the present invention is the inclusion of a light 26 for illuminating the area where the hair is being cut.
When reviewing the present specification, it should be understood that directional terms such as bottom, top, upwardly, downwardly, left, right, etc. have been used for convenience and clarity when referring to the drawing figures only, and are not intended to be read as limitations on the invention or on the operation of the invention.
As shown in FIG. 1, the main body 12 is essentially divided by a primary longitudinal axis 32 into a front side 28 and a rear side 30. It should be noted that when referring to the front side and the rear side, these terms are not intended to imply that the main body 12 is necessarily separated into two parts along the primary longitudinal axis 32, except where specifically described as such. Instead, these terms have been used for directional reference when viewing the drawing figures.
The primary longitudinal axis 32 may also be extended into three dimensions to form a primary longitudinal plane that extends perpendicular to the two dimensional view shown in FIG. 1, where the primary longitudinal plane defined divides the front side 28 and the rear side 30. It should be noted that there is a blade angle α defined between the interface 18 and a cutting plane 34, which is the plane defined by the two mating surfaces of the generally parallel cooperating blades--the stationary blade 20 and the reciprocating blade 22 (FIG. 7). The blade angle α is preferably in the approximate range of between 15° and 45°, and is more preferably about 30°.
To better orient the blade angle α with respect to the main body 12, the main body may include an offset portion 33. The offset portion 33 is offset from the primary longitudinal axis 32 to extend along a secondary axis 35. An offset angle θ is defined between the primary longitudinal axis 32 and the secondary axis 35. Preferably, the offset angle θ is in the range of approximately between 150° and 170°, with approximately 160° being most preferred. It should be noted that the secondary axis 35 is preferably perpendicular to the interface 18.
Some of the benefits of the present invention are also realized where the offset angle θ is 180°, as shown in the alternate embodiment of FIG. 1A. In this alternate embodiment, there is no offset portion, and the primary longitudinal axis 32 defined by the main body 12 is completely linear. One of the main benefits realized in this alternate embodiment is that the blade housing 14 can be rotated so that the controls, such as the switch actuator 45, can be located on either the same side as the cutting surface 24, or on the side opposite to the cutting surface. In this manner the user may select the more comfortable location of the controls for different applications.
Referring back to FIG. 1, one important feature of the present invention is that the interface 18 between the top portion of the main body 12 and the rotatable blade housing 14 is oblique with respect to the primary longitudinal axis 32. This angle, defined as interface angle β, is preferably in the approximate range of between 55° and 85°. More preferably, interface angle β is approximately 70°. The inclusion of oblique interface angle β, in combination with the blade angle α, enables the user to rotate the blade housing 14 to orient the cutting surface 24 between a set range of different predetermined cutting surface angles with respect to the primary longitudinal axis 32. The location of this cutting surface angle has been designated as angle γ in FIG. 1.
Angle γ is important because this angle governs where the main body 12 will be positioned as the trimmer 10 is being used. Normally, as the cutting surface 24 is moved about the areas of the face and neck being trimmed, the user attempts to maintain a relatively constant angle between the cutting plane 34 and the surface being trimmed. This angle is normally termed the approach angle. To maintain a constant approach angle for all of the differently oriented surfaces of the face and neck, the user must continuously adjust the inclination of the main body 12. As the cutting surface angle γ is the relationship between the cutting plane 34 and the primary longitudinal axis 32 of the main body 12, the cutting surface angle γ determines in which direction the main body 12 will extend when cutting different areas of the face and neck. Accordingly, the cutting surface angle γ determines whether the main body 12 will obstruct the view of the area being trimmed, and also whether or not the trimmer 10 can be held in a position that is not awkward for the user.
Of particular importance are the values for the cutting surface angle γ that result when the cutting surface 24 is aligned with either the front side 28 or the rear side 30 because these are the alignments that will most likely be used most often. Turning now to FIGS. 2 and 3, views are shown in which the cutting surface 24 is aligned with the front side 28 (FIG. 2) and the rear side 30 (FIG. 3). Incidentally, FIGS. 2 and 3 also include depictions of an attachment comb 36 with the present hair trimmer 10. Attachment combs are known to those skilled in the art for maintaining a constant approach angle, and also for keeping the cutting surface 24 at a constant distance from the skin.
Returning now to the cutting surface angle γ, it should be noted that two vastly different cutting surface angles are created when the blade housing 14 is rotated 180°. When the cutting surface 24 is aligned with the front side 28 (FIG. 2), the cutting surface angle γ is preferably in the range of approximately between 30° and 60°, with 45° being most preferred. However, when the cutting surface 24 is aligned with the rear side 30 (FIG. 3), the cutting surface angle γ is preferably in the range of approximately between 75° and 85°, with 80° being most preferred. These two cutting surface angles have been chosen to provide the user with two optimal cutting surface angles for cutting the differently oriented areas of the beard with the grain of hair growth (as opposed to against the grain, as conventionally taught).
When using the optional comb 36, an additional angle φ is also defined (FIGS. 2 and 3). Angle φ is the angle defined between the primary longitudinal axis 32 and a line defined by a comb periphery 37. When using comb 36, the comb periphery 37 is frequently the surface that the user slides along the skin of the area being trimmed. Accordingly, angle φ is an important angle related to the direction that the main body 12 of the trimmer 10 will extend when the comb periphery 37 is moved along the surface of the face and neck. In the embodiment shown in the Figures, angle φ is about 90° when the blade surface 24 is facing the front side 28 (FIG. 2), and about 135° when the blade surface 24 is facing the rear side 30 (FIG. 3). An approximate range for angle φ when the blade housing 14 is rotated as shown in FIG. 2 is between 80° and 120°. When the blade housing 14 is rotated as shown in FIG. 3, a suggested approximate range for angle φ is between 125° and 155°.
When cutting with the optional comb 36 along an area of the face or neck that has a certain orientation, such as the generally horizontal orientation under the chin, the user may select the large cutting surface angle γ (and associated large angle φ of FIG. 3, which results in the main body 12 being comfortably held. However, when trimming in another area, such as near the rear of the jawline, the small cutting surface angle γ (and associated small angle φ) of FIG. 2 may provide a less awkward gripping position.
It should also be noted that the present hair trimmer 10 is also ergonomically designed for comfortable hand and arm positioning and improved visibility when edging or otherwise utilizing the trimmer without the optional comb 36. One example of such use is when the user rotates the blade housing 14 into the FIG. 3 position and removes the comb 36 to edge the sideburns, moustache, or beard. With the blade housing 14 rotated into this position, the angle γ between the primary longitudinal axis 32 and the cutting plane 34 is approximately 80° in the preferred embodiment. Thus, edging can be performed with the cutting plane 34 nearly horizontal and the primary longitudinal axis 32 extending essentially vertically. With the trimmer 10 in this position, the user's elbow is in a relaxed position close to the body, and the cutting surface 24 is just slightly angled upwardly with respect to the horizon to enable the user maximum visibility of the area being trimmed. A second example of a comfortable use of the present trimmer 10 when rotated to the FIG. 3 position without the comb is for trimming under the chin by stroking upwardly. The ergonomic benefits for this use are similar to those realized when edging, as described directly above.
In order to maintain the blade housing 14 at a certain rotational position with respect to the main body 12, a pivot lock 38 is provided. In a preferred embodiment, the pivot lock 38 locks the blade housing in either the FIG. 2 position or the FIG. 3 position. The pivot lock 38 can be depressed to enable the blade housing to be rotated to the opposite position than that currently held.
Referring now to FIGS. 5 and 8, the pivot lock 38 is attached to a locking arm 49. This locking arm 49 is normally engaged within a detent 51 (FIG. 5 only) that is located on the blade housing 14. In the preferred embodiment, there are two detents 51 located on opposite sides of an inner circumference of the blade housing 14, where one detent locks the blade housing into the FIG. 2 position and the other detent locks the blade housing into the FIG. 3 position. To unlock the pivot lock 38 in order to rotate the blade housing 14, the pivot lock is simply pressed inwardly, and the locking arm 49 then disengages from the detent 51, which action allows rotation. The blade housing 14 may then be rotated to the opposite position, and the locking arm 49 can be engaged into the opposite detent.
With the present invention, the two optimal cutting surface angles (of FIGS. 2 and 3) are preset so that the user need not make constant adjustments to determine the proper angle. However, for those users that may desire a more customized surface angle γ for certain hard to reach areas, it is also contemplated that the rotatable blade housing 14 may also be configured to be stopped at positions other than those shown in FIGS. 2 and 3. When stopped at one of these intermediate positions, the cutting surface 24 will also be inclined at a different angular orientation than those obtained when the stopped at either the FIG. 2 position or the FIG. 3 position.
In accordance with another important aspect of the present invention, a light 26 may also be provided upon the blade housing 14. Preferably, the light 26 is located just below the cutting surface 24 so that it can illuminate the area where the hair is being cut. It should be noted that the light 26 is fixed to the blade housing 14 so that it rotates therewith. Thus, the light 26 will always be positioned below the cutting surface 24, regardless of the manner in which the blade housing 14 has been rotated with respect to the main body 12.
Turning now to FIGS. 5-9, a description of the internal components of the present hair trimmer 10 will be provided. As shown in FIG. 5, a battery 39 provides power for a motor 40. The battery 39 may be any type of suitable power source, and is preferably rechargeable through a jack 41. An LED 43 is preferably provided to indicate when the battery 39 is in need of a charge. A capacitor 47 and other electronic components associated with rechargeable power sources known to those skilled in the art are shown in FIG. 8. Power is directed from the battery 39 to the motor 40 by turning a switch actuator 45 to the "on" position.
The motor 40 is furnished with a rotating shaft 42. An eccentric cam 44 is fixed upon the rotating shaft 42. The eccentric cam 44 is seated in an elongated slot that is located in a cam follower 48 (FIG. 7). The cam follower 48 is fixed to the reciprocating blade 22. Below the reciprocating blade 22 is the stationary blade 20. The reciprocating blade 22 is biased against the stationary blade 20 by a tension spring 46. Thus, when the cam eccentric 44 turns in the slot of the cam follower 48, this eccentric rotational movement is translated into reciprocating movement that oscillates the reciprocating blade 22 with respect to the stationary blade 20. In this manner, the cutting surface 24 is defined at the point where the teeth of both blades 20 and 22 contact each other.
While one form of cutting mechanism has been shown and described, it is contemplated that other types of blade arrangements may also be used with the present hair trimmer, such as, but not limited to, simplified blade arrangements in which the cutting mechanism 16 consists primarily of a reciprocating blade and a stationary blade that affixes directly to the blade housing along with a means for guiding and applying tension to the moving blade.
Turning now to both FIG. 5 and FIG. 6, which is an enlarged view of area "A" shown in FIG. 5, a description will be provided of the manner in which the blade housing 14 may be rotated with respect to the main body 12. The blade housing 14 and the main body 12 each include complementary L-shaped flanges 52 and 54, respectively. These L-shaped flanges 52, 54 engage with each other to restrain the axial movement of the blade housing with respect to the main body 12. However, as these portions of the blade housing 14 and the main body 12 each have a circular cross-section, the blade housing is free to rotate with respect to the main body. To reduce the radial and axial "play" between these two components during relative rotation, an o-ring 56 may be seated within an o-ring groove 58 in one of the L-shaped flanges. The o-ring 56 also serves to absorb production tolerances and to seal the interface 18. During assembly of the trimmer 10, the two L-shaped flanges 52, 54 may be interlocked by placing the blade housing 14 upon either one of the sides of the main body 14 (i.e. either the front side 28 or the rear side 30) and then the remaining side of the main body 14 is fixed in place to complete the assembly.
FIGS. 7 through 9 provide the best views on how the current is transferred from the battery 39, which is preferably located within the main body 12, to the light 26, which is located on the relatively rotatable blade housing 14. The light 26 includes a light bulb 60, which is seated within a light bulb housing area 62. To protect the light bulb 60 from damage and to better diffuse the light, a light lens 64 (also referred to as a diffuser) is provided. The light lens 64 serves to diffuse the light over a wider area to better illuminate the surface being trimmed. The light lens 64 also prevents hair and other foreign matter from collecting within the light bulb housing area 62. A pair of light bulb leads 66, 68 deliver current to the light bulb 60.
Another important aspect of the present invention is the inclusion of a slip ring 70. The slip ring 70 serves as the link for conveying power across the interface 18 between the main body 12 and the relatively rotatable blade housing 14. The slip ring 70 is fixed with respect to the blade housing 14. Each of the two light bulb leads 66, 68 are electrically connected through the slip ring 70 to a different one of a pair of concentric circles of conductive material, 72, 74. Keep in mind that the two concentric circles 72, 74 are located on the slip ring 70 on the main body side of the interface 18, while the two light bulb leads 66,68 are located on the slip ring on the blade housing side of the interface. Positioned within the main housing are two light contacts 76, 78. Light contact 76 makes an electrical connection with concentric circle 72. The tip 77 of light contact 76 continuously makes sliding contact with the concentric circle 72, even as the concentric circle (and the slip ring 70) are rotated along with the blade housing 14. The tip 77 is preferably curved so that it is slightly biased into the concentric circle 72 to maintain contact therewith. The light contact 78 is similarly slightly biased into continuous electrical contact with the other concentric circle, concentric circle 74, with the tip of light contact 78 preferably being curved in the direction opposite to the curve of tip 77 to minimize potential contact between light contact 76 and light contact 78.
The electrical circuit for the light 26 is primarily defined between the battery 39, which is preferably connected through flexible wires (not shown), or other known means for making electrical contact, with a switch 102 (FIG. 8). The switch 102 is in turn connected to the light contacts 76, 78, which are connected, respectively, to the concentric circles 72, 74 of the slip ring 70. Finally, the concentric circles 72, 74 are also electrically connected to the light leads 68, 66, where the circuit is completed through the light bulb 60.
The present hair trimmer 10 preferably includes two different operating modes: a first mode for trimming without the light and a second mode for trimming with the light. Thus, with the addition of the "off" mode, the switch actuator 45 should preferably be configured as a three-way switch (off, on without light, and on with light). Upon sliding the switch actuator 45 axially, a saddle-shaped member 80 that straddles the motor 40 is moved axially an equal distance as the switch actuator. The saddle shaped member 80 is slidably seated upon a frame 81 via two tabs 83 that ride along a corresponding pair of notches 85 in the frame 81. The notches 85 and the tabs 83 cooperate to prevent the saddle shaped member 80 from being moved too far in the axial direction within the frame 81.
As shown in FIG. 8, the saddle-shaped member 80 includes a pair of arms 82, 84 that make sliding contact with a three-way detent element 86. The three-way detent element 86 is fixed within the main body 12, and is preferably attached to the underside of the motor 40. Thus, the three-way detent 86 element serves to secure both the saddle shaped member 80 and the switch actuator 45 in one of three positions--a first position as shown in FIG. 8; a second position in which the arms 82, 84 are seated within the indented portions 88, 90; and a third position in which the arms 82, 84 are seated upon the inclined portions 92, 94.
When the switch actuator 45 is moved to the "on" position, a first arm 96 on the saddle-shaped member 80 engages a first limit switch 98 and turns on the motor 40. Upon further axial movement of the saddle-shaped member 80 to the "on with light" position, a second arm 100 engages a second limit switch 102, which switches the light bulb 60 to an illuminated state. It should be noted that the second limit switch 102 should be spaced from the first limit switch 98 so that both limit switches are not engaged with the initial movement of the switch actuator 45.
Upon movement of the switch actuator in the reverse direction, the second limit switch 102 is deactivated upon movement from the "on with light" position to the merely "on" position (without the light), and the first limit switch 98 is deactivated next when moving from the "on" position to the "off" position. It should be noted that other configurations for the three way switch are also contemplated as being within the scope of present invention.
While a particular embodiment of the present hair trimmer with a rotatable blade housing and a light has been shown and described, it will be appreciated by those skilled in the art that changes and modifications may be made thereto without departing from the invention in its broader aspects and as set forth in the following claims.
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A hair trimmer that includes a main body extending between an upper end portion and a lower end portion and further includes a front side and a rear side. The main body defines a primary longitudinal axis that extends substantially linearly between the upper end portion and the lower end portion. A blade housing is rotatably attached to the upper end of the main body such that the blade housing is rotatable about the primary longitudinal axis with respect to said main body. The blade housing is defined by an attached side and a free side that is opposite to the attached side. An interface plane is defined between the main body and the blade housing. The interface plane extends at an interface angle that is oblique to the primary longitudinal axis. The present hair trimmer further includes a cutting mechanism that is removably seated upon the said free side of the blade housing. The cutting mechanism includes a cutting surface for engaging and severing hair. As an additional feature, the present hair trimmer may be also equipped with a light for illuminating the area about to be trimmed.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of co-pending U.S. patent application Ser. No. 11/124,594, filed on May 9, 2005, which claims the benefit of priority of Provisional Application Ser. No. 60/571,640, filed May 17, 2004.
BACKGROUND OF THE INVENTION
[0002] This invention presents an energy converter to recover and combine diverse motor vehicle energy sources for supplying compressed working fluid to a motor vehicle prime mover, wherein a liquefied air portion of the working fluid provides pre-compression cooling of an atmospheric air portion thereof; the liquefied air being made by recovered energy, stored and transferred between vehicles and between vehicles and stationary sites.
[0003] Increased fuel mileage and range in conjunction with low grade fuels has long been a goal of automotive design, to make driving more economical, to conserve fossil fuels, and to reduce emission of combustion products. Recovery and combining of vehicle energy sources as available, including kinetic (deceleration and shock), wind resistance, and solar radiation, is not described in the prior art. In addition, coordinated storage and transfer of recovered energy using pneumatic, cryogenic and electric systems is not described in the prior art. Recovery of only the deceleration component of kinetic energy, coordinated with electrical transfer between batteries and generators, is used in lightweight hybrid vehicles to provide limited performance improvement. Relevant vehicle energy recovery and consumption devices described in the prior art have disadvantages, as follows:
[0004] (a) U.S. Pat. No. 1,671,033 to Kimura (1928) describes a transmission with an electric generator and battery storage for recovery of vehicle deceleration, the component of vehicle kinetic energy in the direction of travel. The recovered energy, normally dissipated by engine compression and vehicle braking, is stored in batteries and used for limited electrical power assist. Deceleration energy is not completely recoverable due in part to insufficient battery capacity.
[0005] (b) U.S. Pat. No. 3,688,859 to Hudspeth and Lunsford (1972) describes compressors connected between the frame and axles of a vehicle for recovery of shock, the upward component of vehicle kinetic energy. The recovered energy, normally dissipated by shock absorbers, is used for limited pneumatic power assist. Shock energy is not completely recoverable due to compression heating.
[0006] (c) U.S. Pat. No. 6,138,781 to Hakala (2000) describes an electric generator for recovery of vehicle wind energy. The recovered energy, normally dissipated by vehicle drag force, is used for limited electrical power assist. Potential wind energy recovery is not realized because air from a wind recovery device is discharged to relatively high wake pressure. In addition, aerodynamic vehicle shapes are often used to reduce drag loss at the expense of vehicle function, such as carrying capacity.
[0007] (d) U.S. Pat. No. 5,725,062 to Fronek (1998) describes the use of a solar photo-voltaic panel atop a vehicle for recovery of solar energy radiating to a vehicle. The recovered energy, normally dissipated to the atmosphere, is used for limited electrical power assist. Solar radiation to a vehicle is not completely recoverable due in part to insufficient battery capacity.
[0008] (e) U.S. Pat. No. 4,182,960 to Reuyl (1980) describes transfer of electrical energy between vehicles and stationary sites. Solar energy recovered at a site is stored in batteries to provide power to the site and a portion is transferred to, and stored in batteries in a hybrid gas turbine-electric vehicle. The gas turbine can provide power to the site via an electric generator to supplement site solar energy. Battery storage problems include space and weight limitation, trade-off between battery life and energy discharged, replacement handling, charge time, and ventilation.
[0009] Research programs at the University of Washington (“Ultra-Low Emission Liquid Nitrogen Automobile” Knowlen, Mattick, Hertzberg, and Bruckner, SAE-1999-0102932, 1999) and the University of North Texas (“Cryogenic Heat Engines for Powering Zero Emission Vehicles”, Ordonez, Plummer, and Reidy, IMEECE2001/PID-25620, 2001) describe a liquefied gas system to supply liquid nitrogen for on-board storage and use in zero emissions vehicles powered by ambient temperature heat engines. Transfer of liquefied gas between vehicles and from vehicles to stationary sites, for use thereof, is not described in the prior art. Liquefied gas transfer problems include boil-off and fill and drain connection.
[0010] (f) The prior art describes several types of gas liquefiers including; vapor-compression, magnetic, Stirling cycle and thermo-acoustic, for stationary application. State-of-the-art air liquefiers require compression work of approximately 2.5 times the heat removed per 2.2 kg (1 lb) of air liquefied.
[0011] (g) Gas turbine engine powered vehicles are described in the prior art and were produced by Rover and by Chrysler Corporation during the 1950's and 1960's. Gas turbine engines require high turbine inlet temperature to provide acceptable thermal efficiency. Other problems include high compression work, high turbine blade and exhaust gas temperature, and expensive heat exchangers. Operation is characterized by falling efficiency with load and compression braking is unavailable. Low grade fuels such as kerosene can be burned, however emissions are high due to high fuel consumption and formation of compounds at high temperature.
[0012] (h) U.S. Pat. No. 4,294,323 to Boese (1981) describes a gas expander using cryogenic liquid working fluid. Cryogenic expanders have low specific expansion energy due to heat input at ambient temperature. Research programs at the University of Washington (“Ultra-Low Emission Liquid Nitrogen Automobile” Knowlen, Mattick, Hertzberg, and Bruckner, SAE-1999-0102932, 1999) and at the University of North Texas (“Cryogenic Heat Engines for Powering Zero Emission Vehicles”, Ordonez, Plummer, and Reidy, IMEECE201/PID-25620, 2001) describe development of liquid nitrogen expanders with emphasis on maximizing output by designing for quasi-isothermal expansion. Expanders have limited usefulness in lightweight, short range, low speed vehicles for zero emission urban use.
[0013] (i) U.S. Pat. No. 3,525,874 to Toy (1970) describes a hybrid gas turbine-electric prime mover, and U.S. Pat. No. 3,566,717 to Berman (1971) describes a hybrid transmission for parallel operation of a combustion engine and an electric motor. Recovered deceleration energy, normally dissipated by engine compression and vehicle braking, is stored in batteries and used for power assist in hybrid vehicles. Combustion engine efficiency is low, and deceleration is not completely recoverable due in part to insufficient battery capacity.
SUMMARY OF THE INVENTION
[0014] It is an object of the present invention, therefore, to provide systems for recovery of energy dissipated by a motor vehicle, as well as solar radiation.
[0015] It is another object of the present invention to provide systems for storage and transfer of recovered energy.
[0016] It is still another object of the present invention to provide systems for efficient consumption of recovered energy.
[0017] It is yet another object of the present invention to provide a prime mover capable of burning renewable fuel with improved emissions.
[0018] In keeping with these objects and others, which may become apparent the present invention seeks to provide a unified energy system to recover, store, transfer and consume energy dissipated by motor vehicles, or otherwise available thereto. In essence, combining recoverable energy sources as available yields greater benefit than when taken individually. For example, full potential of a gas turbine is realized using recovered energy to provide the compressed air requirement.
[0019] Combined recovery of vehicle energy sources including kinetic (deceleration and shock), wind resistance, and solar radiation to compress atmospheric air provides substantial vehicle power assist. Recovery is by compression of atmospheric air for consumption as working fluid in vehicle prime movers. Liquefied air is imported to the vehicle as a form of energy storage by providing pre-compression cooling of prime mover working fluid. In addition, a liquefier makes supplementary liquefied air using excess recovered energy, such as during high speed driving when vehicle wind resistance, a function of the third power of speed, predominates. Excess liquefied air is transferred from the vehicle for use in other vehicles or at stationary sites. The recoverable portion of energy dissipated by a vehicle, estimated in accordance with standard highway driving cycle US-06, is: deceleration, 25%; wind resistance, 10%; shock, 10%. In addition 91 kg (200 lb) of imported liquefied air effectively increases the recovered total by 25% and clear day solar radiation adds another 8%. Energy recovery by diverse means enhances performance over a wide range of driving conditions, providing a three-fold increase in prime mover efficiency, because prime mover compression by recovered energy is a virtual energy loss. Accordingly, advantages of the present invention are illustrated as follows:
[0020] (a) A feature of the energy system in accordance with the present invention lies in providing an energy recovery transmission for recovery of vehicle deceleration energy by compression of atmospheric air.
[0021] (b) Another feature of the energy system in accordance with the present invention lies in providing energy recovery shock absorbers with cryogenic cooling for efficient compression of atmospheric air.
[0022] (c) Another feature of the energy system in accordance with the present invention lies in providing an energy recovery turbine to drive an atmospheric air compressor. The turbine operates on the difference between wind impact pressure and wake pressure at high suction locations behind an air dam, the windshield/roof intersection, and other leading edges. Vehicle shapes are designed for the best use of recovered wind energy as it effects vehicle cost, carrying capacity and style.
[0023] (d) Another feature of the energy system in accordance with the present invention lies in providing an energy recovery solar-electric panel to drive an atmospheric air compressor. Energy is recovered during parking, stopping and driving of a vehicle.
[0024] (e) Another feature of the energy system in accordance with the present invention lies in providing air compression and liquefied air storage of recovered energy, plus capability to transfer liquefied air between vehicles or between vehicles and stationary sites. In addition air compression provides vehicle braking assist.
[0025] (f) Another feature of the energy system in accordance with the present invention lies in providing an on-board vehicle air liquefier to liquefy suitably pure atmospheric air. Required liquefier compression is equivalent to that of state-of-the-art liquefiers, however work input using recovered vehicle energy is a virtual energy loss.
[0026] (g) Another feature of the energy system in accordance with the present invention lies in providing an efficient gas turbine prime mover. Compression, using recovered vehicle energy above approximately 25% turbine load, is a virtual energy loss. Pre-compression cooling of working fluid with liquefied air enables reduced turbine inlet and exhaust temperatures. Heat input is from a renewable fuel, such as methanol. Efficiency is relatively constant over the load range and low fuel consumption lowers emissions while expanding fuel choices.
[0027] (h) Another feature of the energy system in accordance with the present invention lies in providing a quasi-isothermal liquefied air expander for urban driving. Compression work, using recovered vehicle energy, is a virtual energy loss.
[0028] (i) Still another feature of the energy system in accordance with the present invention lies in providing a gas turbine/air expander with virtual compression to power a hybrid vehicle. The gas turbine operates independently and efficiently over a wide load range. The expander and gas turbine operate in parallel with the added benefit of turbine exhaust heat recovery into the working fluid of the expander. The expander operates independently during urban driving when the gas turbine is least efficient.
[0029] Other general and more specific objects and advantages of the present invention will in part be obvious and will in part appear from the drawings and description which follows.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] Objects and advantages of the present invention will become apparent from the following when read in conjunction with the accompanying drawings and reference numerals list, wherein solid lines connecting components indicate fluid flow, arrows indicate flow direction, and dashed lines indicate electrical connection:
[0031] FIG. 1 is a schematic illustration showing connection of components of an energy recovery, storage, transfer and consumption system in a motor vehicle.
[0032] FIG. 2 is a schematic illustration of one of four shock compressors connected in the motor vehicle of FIG. 1 .
[0033] FIG. 3 is a schematic illustration of a solar electric panel connected to drive an air compressor in the motor vehicle of FIG. 1 .
REFERENCE NUMERALS
[0000]
FIG. 1 :
10 vehicle (typical)
11 gas turbine engine
12 air expander
13 transmission-generator drive
14 shaft
15 rear wheel-axle assembly
16 motor controller
17 motor-compressor
18 axial wind drive
19 clutch
20 motor-compressor shaft
21 windshield
22 air dam
23 compartment
24 air duct
25 compressed air tank
26 air liquefier
27 liquefier intake valve
28 liquid air tank
29 vent valve
30 liquid air fill valve
31 liquid air drain valve
32 liquid air pump
33 evaporator
34 header
35 pumped air valve
36 compressed air valve
37 throttle
38 expander valve
39 gas turbine
40 combustor
41 recuperator
42 fuel tank
43 fuel pump
44 heating jacket
FIG. 2 :
45 shock compressor drive
46 front wheel-axle assembly
FIG. 3 :
47 solar photo-voltaic panel
DESCRIPTION OF PREFERRED EMBODIMENTS
[0075] FIG. 1 illustrates a preferred embodiment of the energy recovery, storage, transfer and consumption system of the present invention installed in a motor vehicle 10 . An engine 11 combined with an air expander 12 by a transmission-generator drive 13 provides prime mover propulsion to the vehicle via a shaft 14 and a rear wheel-axle assembly 15 . Deceleration energy is recovered by drive 13 , which is electrically connected to a motor controller 16 to power a motor-compressor 17 . Wind energy is recovered by an axial wind drive 18 connected to motor-compressor 17 through a clutch 19 , which provides torque to a motor-compressor shaft 20 when wind energy is sufficient. Drive 18 operates on the difference between impact pressure and wake suction pressure behind a windshield 21 and an air dam 22 . Impact air pressurizes a compartment 23 and discharges through an air duct 24 . Motor-compressor 17 compresses air into a compressed air tank 25 . An air liquefier 26 draws atmospheric air through a liquefier intake valve 27 and discharges liquefied air to a liquefied air tank 28 while venting through a vent valve 29 . Liquefied air is transferred to the vehicle into tank 28 through a liquefied air fill valve 30 and transferred from the vehicle through a liquefied air drain valve 31 .
[0076] Liquefied air is pressurized by a liquefied air pump 32 and vaporizes while cooling atmospheric air in an evaporator 33 . The cooled air is pressurized by motor-compressor 17 , mixed with the vaporized air in a header 34 , and the mixture delivered to the engine and the expander under control of a pumped air valve 35 and a compressed air valve 36 . The ratio of expander air to combustion air is controlled by a throttle 37 and an expander valve 38 .
[0077] Engine 11 is a gas turbine 39 connected to a combustor 40 and a recuperator 41 . Fuel is stored in a fuel tank 42 and pressurized by a fuel pump 43 . Combustion products from the recuperator pass through a heating jacket 44 of the expander to atmosphere.
[0078] Evaluation of vehicle highway performance is based on US-06 (Supplemental Federal Test Procedure) for 6 hours at average speed of 77 km/hr (48 mph). US-06 is the most aggressive real highway driving cycle and illustrates the combination of deceleration drive 13 and wind drive 18 . Methanol fuel is selected because it is renewable, air requirements are low due to oxygen content, and large scale production is enabled by use in high efficiency engines. With an initial fill of 91 kg (200 lb) of liquefied air, “gasoline equivalent mileage” is 25 km/l (150 mpg) and liquefied air consumption is 113 kg (250 lb), for a distance 463 km (288 ml).
[0079] Evaluation of vehicle urban performance is based on LA-92 (California Air Resources Board) for 4 hours at average speed of 40 km/hr (25 mph). LA-92 is the most aggressive real urban driving cycle and illustrates operation when vehicle speed is too low for effective recovery of wind energy. Efficient operation is with engine 11 off, expander 12 operating on air from tank 25 , and wind drive 18 disengaged by clutch 19 . With an initial fill of 91 kg (200 lb) of liquefied air, “liquefied air equivalent mileage” is 1.9 km/kg (0.53 ml/lb) for a distance 161 km (100 ml).
[0080] Drive 13 recovers deceleration energy while prime mover air consumption drops, providing electrical power to motor-compressor 17 and liquefier 26 based on pressure in tank 25 . Drive 18 recovers wind energy during forward motion of the vehicle above approximately 56 km/hr (35 mph) due to difference of 2.5 velocity heads between vehicle impact pressure and wake suction pressure behind windshield 21 and air dam 22 . Excess wind energy for liquefied air production is recovered at an increasing rate, proportional to the third power of vehicle speed. Estimated deceleration recovery is 75% of vehicle acceleration and estimated wind recovery is 25% of vehicle wind resistance.
[0081] Quasi-isentropic motor-compressor 17 normally maintains expander and engine air pressure in tank 25 at 300 K (540 R), 4 mPa (40 atm) with valve 27 and 30 closed and valves 35 and 36 open. Estimated efficiency of the motor-compressor is 80%.
[0082] Air liquefier 26 operates on over-pressure in tank 25 to deliver 23 kg (50 lb) of liquefied air to tank 28 during 6 hours of US-06 driving with valve 29 open and valves 27 and 30 closed. Estimated liquefaction energy is 1395 kj/kg (600 btu/lb) of liquefied air produced; approximately twice the ideal and one-half the energy input of commercial liquefiers.
[0083] Combined engine 11 and expander 12 deliver up to 71 kW (95 hp) to meet US-06 vehicle acceleration. Engine output is 15100 kJ/kg (6500 btu/lb) of fuel with an air-fuel ratio of 15, and turbine inlet temperature is 1500 K (2700 R) at 4.0 mPa (40 atm). Methanol consumption is 1.5 kg/hr (3.3 lb/hr) with total liquefied air of 19 kg/hr (42 lb/hr). Engine exhaust gas, including latent heat of condensable products, maintains jacket 45 inlet air temperature of 444 K (800 R) at 4.0 mPa (40 atm), and exhaust temperature of 300 K (540 R). Expander output is 1400 kJ/kg (600 btu/lb) of liquefied air, and drops by 50% with the engine off and no exhaust heating. Estimated engine and expander efficiencies are 85%.
[0084] FIG. 2 illustrates an embodiment of the present invention for recovery of vehicle shock energy. A four shock compressor drive 45 (typical), connected to each end of rear wheel-axle assembly 15 and to each end of a front wheel-axle assembly 46 , provides compressed air from evaporator 33 into tank 25 .
[0085] Drive 45 recovers an additional 9% of US-06 driving resistance, increasing fuel mileage of the FIG. 1 configuration by 12% and liquefier output by 58%. Air from evaporator 33 at 94 K (170 R) is compressed into tank 25 at 300 K (540 R), 4 mPa (40 atm) by action of the shock compressor drive due to reciprocating wheel-axle motion. Recovered shock energy is estimated at 30% of rolling resistance, a function of road surface roughness, vehicle speed, and tire pressure, as well as bearing friction.
[0086] FIG. 3 illustrates an embodiment of the present invention for recovery of solar radiation by a solar photo-voltaic panel 47 atop the vehicle. Electrical output from the panel to controller 16 powers motor-compressor 17 and liquefier 26 .
[0087] Panel 47 recovers an equivalent 8% of US-06 driving resistance, increasing fuel mileage of the FIG. 1 configuration by 8% and liquefier output by 48%. Because energy recovery also occurs during vehicle inactivity, liquefier output accumulates. Recovered energy is based on a representative 4.6 m2 (50 ft2), 20% efficient panel in sun. Atmospheric air is compressed into tank 25 at 300 K (540 R), 4 mPa (40 atm).
[0088] Although the description above contains many specifics, these should not be construed as limiting the scope of the invention, but only to provide illustrations of some of the preferred embodiments of this invention. For example;
[0089] The energy recovery, storage, transfer and consumption system of the present invention can be used in trucks and other vehicle types using any suitable fuel or working fluid.
[0090] Deceleration, wind, shock and solar energy can be recovered in combination to provide mechanical or electrical drive of prime mover working fluid compressors or other vehicle components.
[0091] Electric batteries can be used to supplement energy storage.
[0092] Vapor-compression, two phase expansion, magnetic, thermo-acoustic, thermoelectric and Stirling liquefiers can be used, and emissions features such as air separation for constituent liquefaction can be added. A liquefier expansion-engine can be used for power assist of vehicle components.
[0093] Diesel or other engine types can be used separately or in combination with a gas expander as series or parallel hybrid prime movers. A gas turbine engine can have performance features such as working fluid reheat; and emissions features such as separation of carbon dioxide from combustion products, support of combustion by oxygen enriched air, and combustion cooling by water, nitrogen or other fluid. A gas expander can have performance features such as injection of heat transfer fluid to increase temperature and improve expansion isothermicity of the working fluid.
[0094] Thus the scope of the invention should be determined by the appended claims and their legal equivalents, rather than the examples given.
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An energy conversion apparatus using recovered energy sources including motor vehicle kinetic energy and wind resistance, supplemented by liquefied air transferred to the vehicle and by solar radiation thereto. The energy sources are combined, as available, to drive a compressor for supplying intake working fluid of a motor vehicle prime mover.
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This invention relates to the production of surface-patterned materials, and, more particularly, to a method of producing surface-patterned materials, such as pile fabrics, having multiple surface heights by application of pressurized heated fluid streams to selected surface areas thereof. The invention also includes patterned products produced by such method.
BACKGROUND OF THE INVENTION
It is known to impart visual surface changes to pile fabrics containing thermoplastic pile yarns by directing pressurized heated fluid streams, such as air or steam, into selected areas of the pile surface of the fabric to thermally modify and change the visual appearance of the pile yarns in such areas. U.S. Pat. No. 3,613,186 discloses apparatus for producing pattern effects in pile fabrics by directing heated pressurized air into the fabric from a row of jets mounted in a long heater block which may be moved into two directions over the fabric which also may be moving. Air is supplied to the heater jets through individual air supply lines from an elongate air manifold, and a manually operated valve is provided in each supply line to permit certain of the jets to be cut off, or the air flow thereto to be altered, to change the particular design to be applied to the fabric. Heated air streams striking the pile fabric surface are stated to produce sculptured effects in the thermosplastic surface components thereof, and the pattern is produced by movement of the jets and/or fabric in directions related to each other.
Other apparatus for applying heated pressurized fluid streams to the surface of pile fabrics to alter their surface appearance are disclosed in U.S. Pat. Nos. 2,241,,222; 3,010,179; and 3,585,098. Generally such prior art apparatus provide a continuous flow of the heated fluid streams into the moving fabric during the patterning operation, and the pattern is obtained by relative movement of the fabric and stream applicator manifold during the treating operation.
In hot fluid stream patterning of pile fabrics and other substrate materials having thermally modifiable surface components, highly precise control of the pressure, temperature and direction of the streams striking the substrate material is required to obtain corresponding uniformity and preciseness in the resultant surface pattern formed in the material. If the heated fluid streams are discharged from a row of discharge outlets disposed across a moving pile fabric, unless the temperature and pressure of all streams across the width of the fabric is controllable, variations can occur in the shrinkage and compaction of the pile yarns contacted thereby, resulting in undesirable pattern irregularities in the fabric product.
Difficulties are encountered in maintaining precise control of the pressure and temperature of individual heated fluid streams when their rate of flow is controlled by use of conventional valves located directly in the heated fluid stream supply lines. For example, if the streams are discharged through individual jets having individual manually adjustable valves and a common heater for heating the jets, as in prior U.S. Pat. No. 3,613,186, it can be appreciated that when the rate of air fluid flow through one of the jets is varied by its manual control valve, the temperature of the air stream striking the fabric may increase or decrease because of the change in air flow through the heater. In like manner, if certain jets are completely cut off, the temperature of the heater block will tend to increase in that area, causing an increase in the temperature of the streams from the adjacent jets.
Recently, apparatus has been developed for more precise and uniform control of temperature and pressure of pressurized heated fluid streams to enable more precise and intricate patterning of relatively moving substrate materials, such as textile pile fabrics. Such apparatus comprises an elongate pressurized heated air distribution manifold having a row of heated air discharge channels located in closely spaced relation across the path of the moving substrate material to discharge heated air streams in the material surface. Air is supplied to the manifold through a bank of individual heater units which are controlled to introduce the air into the manifold at a uniform temperature at uniformly spaced locations across its full width. Flow directing baffles provided within the manifold uniformly distribute the incoming air as it flows across the manifold to the discharge channels, and the air is thus discharged therefrom in streams of uniform temperature and pressure.
Flow of the heated air through the discharge channels of the above-described manifold is controlled by the use of pressurized cool air which is delivered by individual cool air supply lines into each channel to block the passage of heated air flow therethrough. Each cool air supply line is provided with an individual control valve, and the cool air control valves are selectively opened or closed in response to signal information from a pattern source, such as a computer program, to block or allow the flow of heated air streams to strike the woving fabric in selected areas and impart a pattern thereto. Depending upon the pattern control information, the surface pattern applied to the fabric can be selectively varied in both lengthwise and widthwise direction of the fabric movement.
In use of such improved apparatus to pattern pile fabrics containing thermoplastic pile yarns, the pressurized air streams which strike selected surface areas of the moving fabric uniformly longitudinally shrink and compact the pile yarns into the fabric in such areas to form precise grooves of uniform depth, with the length of the grooves and their spacing in the fabric being controlled by the pattern control information sent to the cool air valves to produce a precise surface pattern characterized by untreated high pile areas and uniformly thermally treated low pile height areas.
BRIEF OBJECTS OF THE INVENTION
It is an object of the present invention to provide a method of patterning a substrate material containing thermally modifiable surface components by application of pressurized heated fluid streams to selected surface areas of the material to achieve multiple surface height pattern effects therein.
It is another object to provide a method of heated fluid stream patterning of pile fabrics in accordance with pattern control information, wherein the heated fluid streams striking the fabric are controlled in temperature to provide fabric patterns characterized by areas of high, low and intermediate pile heights.
It is a further object to provide novel multiple height surface-patterned materials, such as pile fabrics, by heated stream thermal modification of the surface components thereof.
BRIEF DESCRIPTION OF THE INVENTION
The present invention is directed to a method of precisely patterning thermally modifiable substrate material surfaces by use of the above described improved heated fluid stream patterning apparatus, wherein increased patterning capabilities are obtained. More specifically, the method of the present invention provides for multiple height surface patterning of substrates, particularly pile fabrics containing thermoplastic yarn components, by controlling the temperature of the pressurized fluid striking selected surface areas thereof, such that high, low, and intermediate surface height patterns may be produced in the substrate, while minimizing pattern irregularities resulting from uncontrolled pressure and temperature variations in the streams.
It has been found that the temperature of fluid in a particular stream striking a selected surface area of a pile fabric during its relative movement may be varied to provide greater or less thermal shrinkage and compaction of the pile yarns by introducing controlled amounts of a cooler fluid into the heated air stream such that controlled amounts of cooler fluid are blended with the heated fluid to lower its temperature by a desired amount. Depending upon the temperature of the pressurized fluid striking a selected pile surface area, the pile yarns therein are correspondingly shrunk and compacted to varying degrees, thereby producing patterned pile fabrics characterized by high, low, and intermediate heights of pile in the fabric surface. Such effect can be achieved both in lengthwise and widthwise direction of the fabric and provides broader patterning capabilities with a high degree of precision and accuracy than is believed to have been attainable heretofore.
BRIEF DESCRIPTION OF THE FIGURES OF THE DRAWINGS
The above as well as other objects of the present invention will become more apparent, and the invention will be better understood, from the following detailed description thereof, when taken together with the accompanying drawings, in which:
FIG. 1 is a schematic side elevation view of apparatus for pressurized heated fluid stream treatment of a moving substrate material which may be employed to impart a desired surface pattern thereto in accordance with the method of the present invention;
FIG. 2 is an enlarged partial sectional elevation view of the heated fluid distributing manifold assembly of the apparatus of FIG. 1, taken along a section line of the manifold assembly indicated by the line II--II in FIG. 6.
FIG. 3 is a front elevation view of end portions of the fluid distributing manifold assembly of FIG. 1 looking in the direction of arrow III in FIG. 2;
FIG. 4 is an enlarged broken away sectional view of the fluid stream distributing manifold housing of the manifold assembly illustrated in FIG. 2;
FIG. 5 is an enlarged broken away sectional view of an end portion of the fluid stream distributing manifold housing looking in the direction of arrows V--V in FIG. 4;
FIG. 6 is a plan view of end portions of the manifold assembly of FIG. 2, with portions thereof broken away;
FIG. 7 is a diagrammatic representation of the patterning control components for activating and deactivating the flow of the pressurized heated fluid streams from the manifold assembly of FIGS. 1-6; and
FIG. 8 is a cross-sectional representation of pile fabric treated in accordance with the method of the present invention, and illustrating the multiple height patterning of the yarn components of the same.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Referring more specifically to the drawings, FIG. 1 shows, diagrammatically, an overall side elevation view of apparatus for pressurized heated fluid stream patterning of a moving substrate material in accordance with the method of the present invention. The apparatus includes a main support frame with end frame support members, one of which 10 is illustrated in FIG. 1. Mounted for rotation to the end members of the frame are a plurality of guide rolls which direct an indefinite length textile pile fabric 12 containing thermoplastic pile yarns from a fabric supply roll 14, past a pressurized heated fluid treating unit, generally indicated at 16. After treatment, the fabric is collected in continous manner on a take-up roll 18. As shown, the pile fabric 12 from supply roll 14 passes over an idler roll 20 and is fed by a pair of driven rolls 22, 24 to a main driven fabric support roll 26 to pass the pile surface of the fabric closely adjacent the heated fluid discharge outlets of a fluid distributing manifold assembly 30 disposed across the path of fabric movement. The treated fabric 12 thereafter passes over driven guide rolls 32, 34 and an idler roll 36 to the take up roll 18 for collection.
As schematically illustrated in FIG. 1, the fluid treating unit 16 includes a source of compressed fluid, such as an air compressor 38, which supplies pressurized air to an elongate air header pipe 40. Header pipe 40 communicates by a series of air lines 42 spaced uniformly along its length with a bank of individual electrical heaters indicated generally at 44. The heaters 44 are arranged in parallel along the length of manifold assembly 30 and supply heated pressurized air thereto through short, individual heated air lines, indicated at 46, which communicate with assembly 30 uniformly along its full length. Air supply to the fluid distributing manifold assembly 30 is controlled by a master control valve 48, pressure regulator valve 49, and individual precision control valves, such as needle valves 50, located in each heater air supply line 42. The heaters are controlled in suitable manner, as by temperature sensing means located in the outlet lines 46 of each heater, with regulation of air flow and electrical power to each of the heaters to maintain the heated fluid at a uniform temperature and pressure as it passes into the manifold assembly along its full length. Typically, for patterning most textile pile fabrics containing thermoplastic pile yarns, the heaters heat the air entering the manifold assembly to a uniform temperature of between about 700° F.-750° F.
Manifold assembly 30 is disposed across the full width of the path of movement of fabric 12 and closely adjacent the pile surface to be treated. Although the length of the manifold assembly may vary, typically in the treatment of textile fabric materials, the length of the manifold assembly may be 76 inches or more to accommodate fabrics of up to about 72 inches in width.
As illustrated in FIGS. 1 and 6, the elongate manifold assembly 30 and the bank of heaters 44 are supported at their ends on the end frame support members 10 of the main support frame by support arms 52 which are pivotally attached to end members 10 to permit movement of the assembly 30 and heaters 44 away from the surface of the fabric 12 and fabric supporting roller 26 during periods when the movement of the fabric through the treating apparatus may be stopped.
Details of the heated fluid-distributing manifold assembly 30 may be best described by reference to FIGS. 2-6 of the drawings. As seen in FIG. 2, which is a partial sectional elevation view through the assembly, taken along line II--II of FIG. 6, the manifold assembly 30 comprises a first large elongate manifold housing 54 and a second smaller elongate manifold housing 56 secured in fluid tight relationship therewith by a clamping means generally indicated at 58. The manifold housings 54, 56 extend across the full width of the fabric 12 adjacent its path of movement. Clamping means 58 comprises a plurality of manually-operated clamps 60 spaced along the length of the housings. Each clamp includes a first portion 62 fixedly attached, as by welding, to the first manifold housing 54, and a second movable portion 64 pivotally attached to fixed portion 62 by a manually operated handle and linkage mechanism 66. Second portion 64 of clamp 60 includes an adjustable threaded bolt and nut assembly 68 with elongate presser bars 70 which apply pressure to manifold housing 56 through a plurality of spacer blocks 72 which are attached to the surface of housing 56 at spaced locations along its length (FIG. 6).
As best seen in FIG. 2, first elongate manifold housing 54 is of generally rectangular cross-sectional shape, and includes a pair of spaced plates forming side walls 74, 76 which extend across the full width of the path of fabric movement, and elongate top and bottom wall plates 78, 80 which define an elongate fluid-receiving compartment 81, the ends of which are sealed by end wall plates 82 suitably bolted thereto. Communicating with bottom wall plate 80 through fluid inlet openings (one of which, 83, is shown in FIG. 2), spaced uniformly therealong are the air supply lines 46 from each of the electrical heaters 44. The side walls 74, 76 of the housing are connected to top wall plate 78 in suitable manner, as by welding, and the bottom wall plate 80 is removably attached to side walls 74, 76 by bolts 84 to permit access to the housing compartment 81. The plates and walls of the housing 54 are formed of suitable high strength material, such as stainless steel, or the like.
As best seen in FIGS. 2, 4 and 6, upper wall plate 78 of manifold housing 54 is of relatively thick construction and is provided with a plurality of air flow passageways 86 which are disposed in uniformly spaced relation along the plate in two rows to communicate the housing compartment 81 with a central elongate channel 88 in the outer face of plate 78 which extends between the passageways along the length of the plate. As seen in FIG. 6, the passageways in one row are located in staggered, spaced relation to the passageways in the other row to provide for uniform distribution of pressurized air into the central channel 88 while minimizing strength loss of the elongate plate 78 in the overall manifold assembly.
As seen in FIG. 2, located in manifold housing 54 and suitably attached to the bottom wall plate 80 of the housing, as by threaded bolts (not shown), is an elongate channel-shaped baffle plate 92 which extends along the length of the housing compartment 81 in overlying relation to wall plate 80 and the spaced air inlet openings 83 to define a fluid-receiving chamber in the compartment having side openings or slots 94 adjacent wall plate 80 to direct the incoming heated air from the bank of heaters in a generallfy reversing path of flow through compartment 81. Disposed above channel-shaped baffle plate 92 in housing compartment 81 between the air inlet openings and air outlet passgeways 86 is an elongate filter member 96 which consists of a perforated generally J-shaped plate 98 with filter screen 100 disposed thereabout. Filter member 96 extends the length of the first manifold housing compartment 81 and serves to filter foreign particles from the heated pressurized air during its passage therethrough. Access to the housing compartment by way of removable bottom wall plate 80 permits periodic cleaning and/or replacement of the filter member, and the filter member is maintained in position in the compartment by frictional engagement with the side walls 74, 76 to permit its quick removal from and replacement in the housing compartment.
As seen in FIGS. 2 and 4, the smaller fluid stream distributing manifold housing 56 comprises first and second opposed elongate wall members 102, 104, each of which has an elongate recess 108 therein. Wall members 102, 104 are disposed in spaced, coextensive parallel relation with their recesses 108 in facing relation to form upper and lower wall portions of a fluid-receiving compartment 110 of the second manifold housing 56. Ends of the second housing compartment 110 are closed by end plates 111 (FIG. 3). The opposed wall members 102, 104 are maintained in spaced relation by an elongate front shim plate 112 which has a plurality of parallel, elongate notches 114 (FIG. 5) in one side edge thereof, and a rear elongate shim plate 116 disposed between the opposed faces of the wall members in fluid tight engagement therewith. As seen in FIGS. 2-4, the notched edge of shim plate 112 is disposed between the first and second wall members along the front elongate edge portions thereof to form with wall members 102, 104, a plurality of parallel heated air discharge outlet channels 115 which direct heated pressurized air from the second manifold compartment 110 in narrow, discrete streams at a substantially right angle into the surface of the moving fabric substrate material 12. Dowel pins 117 (FIGS. 2 and 4) spaced along housing compartment 110 facilitate alignment of shim plate 112 between wall members 102, 104. Typically, in treatment of pile fabrics containing thermoplastic pile yarn or fiber components, the discharge channels 115 of manifold 56 may be 0.012 inch wide and uniformly spaced on 0.1 inch centers, with 756 discharge channels being located in a row along a 76 inch long manifold assembly. For precise control of the heated air streams striking the fabric, the manifold stream discharge outlets are preferably maintained between about 0.020 to 0.030 inch from the fabric surface being treated.
Lower wall member 104 of the second manifold housing 56 is provided with a plurality of spaced air inlet openings 118 (FIGS. 2 and 4) which communicate with the elongate channel 88 of the first manifold housing 54 along its length to receive pressurized heated air from the first manifold housing into the second manifold housing 56 compartment 110. Wall members 102, 104 of the second manifold housing are connected at spaced locations by a plurality of threaded bolts 120 and the second manifold housing is maintained in fluid tight relation with its shim members and with the elongate channel 88 of the first manifold housing by the adjustable clamps 60. Guide means, comprising a plurality of short guide bars 122 attached to the second manifold housing 56 and received in guide bar openings of brackets 124 attached to the first manifold housing 54, ensure proper alignment of the first and second manifold housings during their attachment by the quick-release clamps.
Each of the heated air discharge outlet channels 115 of the second manifold housing 56 which direct streams of air into the surface of fabric 12 is provided with an air tube 126 (FIGS. 2 and 3) which communicates at a right angle to the discharge axis of the channel to introduce pressurized cool air into the channel in accordance with pattern control information, as will be explained. Air passing through the air tubes 126 may be cooled by a water jacket 127 (FIGS. 2 and 4) which is provided with cooling water from a suitable source, not shown. As seen in FIG. 1, pressurized unheated air is supplied from compressor 38 through a master control valve 128, pressure regulator valve 129, and air line 130 to cool air header pipe 132. Header pipe 132 is connected by a plurality of air supply lines 134 to an array of solenoid-operated, off-on control valves, v, located in a control valve box 136, with a control valve provided for each of the cool air tubes 126 and connected thereto by an individual cool air supply line 137 to control flow of cool air therethrough. These individual control valves are electrically operated to open or close for desired periods of time in response to electrical signals from a pattern control device, illustrated at 138, to selectively introduce pressurized cool air into the individual hot air discharge channels 115 during movement of the fabric.
As seen in FIGS. 2-4, located in the lower wall member 104 of manifold housing 56 between each of the pressurized heated air discharge outlet channels 115 is an air outlet tube 140. Each outlet tube 140 is in continuous communication with the heated air compartment 110 of housing 56 by a passageway 142 to continously bleed-off a portion of heated pressurized air from the housing compartment 110 and direct the same away from the surface of the moving fabric 12 (FIG. 4). The bleed-off of hot air heats the wall portions of the manifold housing 56 and the shim plate 112 to counteract cooling of the same by the pressurized cool air introduced into the channels for blocking the heated air streams.
A preferred form of pattern control mechanism 138 for opening and closing the cool air control valves to block the flow of selected heated pressurized air streams onto the fabric, or to blend cool air with the heated air for multiple height patterning in accordance with the present invention, is illustrated diagrammatically in FIG. 7 of the drawings. As seen, operatively attached to the rotating support shaft of the driven fabric support roll 26 is a transducer 50, such as a Litton Model 70 Optical Rotary Pulse Generator. Transducer 150 translates rotary motion of the fabric roll 26, and thus linear movement of the pile fabric 12 past the hot air discharge manifold, into a series of electrical pulses which are fed to a pattern storage and control unit 152. Unit 152 may typically be a conventional EPROM unit (Eraseable, Programmable, Read-Only Memory), such as an Intel Model P-2708 EPROM, into which pattern information in the form of binary logic is stored. Each pulse from the transducer 150 is translated into electrical pattern signals by the EPROM which are sent to selected of the cold air valves in valve box 136, to open or close the same and correspondingly control the flow of cold pressurized air via line 137 into the hot air discharge channels of the manifold assembly 30. Typically, the transducer 150 may produce forty signal pulses per inch of fabric movement, such that any of the valves controlling the pressurized cool air may be opened or closed as many as 40 times per linear inch of fabric surface passing the hot air stream manifold assembly 30. The pattern control circuitry may include time delay means to allow cool air to flow for fractional parts of a transducer pulse cycle, i.e., for time periods equivalent to less than 0.025 linear inches of fabric travel.
In use of the above described apparatus to pattern a pile fabric containing thermoplastic yarn components to produce a high and uniformly low surface pattern effect therein, the temperature and pressure of the heated air in the manifold assembly is set at a desired level, depending upon the thermal characteristics of the fabric to be treated, the speed of the fabric surface past the hot air discharge manifold, and the maximum depth of the grooves, i.e., shrinkage and compaction of the pile yarns, desired. Typically, in the treatment of polyester pile fabrics at a fabric speed of movement of between six to eight yards per minute, the temperature of the heated air in the manifold assembly may be between 700°-750° F., and the pressure between 11/2 to 4 psig.
During fabric movement, pattern information from the EPROM opens selected of the cold air valves at predetermined intervals established by fabric movement (signals from transducer 150) to block the flow of selected of the heated air streams and to thereby produce no effect in the pile surface height, or closes the valves to allow selected of the heated air streams to strike the fabric to longitudinally shrink and compact the pile yarns therein, thus forming narrow grooves of precise width and uniform depth. Because the temperature and pressure of the heated streams are maintained substantially constant across the width of the manifold, all of the grooves formed by full flow of heated air from the manifold into the fabric surface will be of uniform depth.
In accordance with the present invention, it has been found that if selected of the cold air control valves are rapidly opened and closed during fabric movement past the hot air distributing manifold 30, the small amounts of cold air introduced into the hot air streams do not block the passage of the hot air stream, but blend with the hot air leaving the manifold discharge channels to reduce the temperature of the stream by a controllable amount, dependent upon the amount of cold air which is blended into the hot air stream. Thus, it can be seen that the temperature of each of the hot air streams striking the fabric may be varied in a controlled manner to cause corresponding controlled variation in the amount of pile shrinkage, i.e., height reduction, in the area of the fabric contacted by the streams to produce a surface effect having high, low and various intermediate levels of pile therein.
The following specific example illustrates how the method of the present invention may be carried out with the apparatus hereinabove described. A continuous length 100% polyester knit pile fabric having a fabric thickness of 0.090 inches is passed through the fluid-stream treating apparatus of FIG. 1 at a linear speed of 8 yards per minute. The temperature of the heated air in the hot air manifold 30 is maintained at 700° F. and the discharge outlets of the manifold are set at a distance of 0.030 inches from the pile surface of the fabric. The heated air pressure in the manifold is 31/2 psig and the cooler air pressure in the cold air header pipe 132 is maintained at 20 psig. The transducer unit 150 transmits 40 signal pulses per inch of fabric travel past manifold 30 to the EPROM unit 152, and the EPROM unit is provided with a suitable pattern program to translate the pulses into electrical signals to open and close selected of the cold air valves in accordance with the desired pattern to be applied to the fabric.
FIG. 8 schematically illustrates, in vertical cross section, a widthwise portion of the polyester pile fabric 160 treated under the above conditions. As illustrated, four narrow grooves 161-164 have been formed in the pile surface in the direction of fabric movement past the hot air discharge manifold, with the pile yarns in the grooves being longitudinally shrunk and compacted by varying amounts. Portions of the pile fabric surface between the grooves have not been treated by contact with the hot air streams, and thus retain the normal pile height level of the fabric before treatment. In such areas, the cold air streams are continuously discharged into the hot air discharge channels of the manifold 30 to block the passage of heated air streams into the surface of the fabric.
The left hand groove 161, containing pile yarns of slightly reduced pile height, is formed by opening the cool air valve associated with the hot air discharge channel forming the groove in short pulses of approximately 10 milliseconds, separated by intervals of 5 milliseconds, to introduce incremental amounts of cool air into the heated air stream. Groove 162 is formed by introducing 5 millisecond pulses of cool air into the heated air discharge channel forming the groove separated by intervals of 5 milliseconds, while groove 163 is formed by introducing 5 millisecond pulses of cool air separated by intervals of 10 millisecond duration. The right hand most groove 164 is formed by maintaining the cool air control valve associated therewith closed during movement of the fabric, thereby permitting the full effect of the heated air stream to strike the fabric surface.
Thus, it can be seen that by precise control of the introduction of cool air into the heated air discharge channels of the manifold assembly, a pile surface pattern effect characterized by high, low and intermediate pile height areas is produced, with temperature regulation of the heated air streams by the cool air producing the desired effect in the fabric surface.
Although the apparatus for practicing the method of the present invention has been described as including a hot air discharge manifold 30 with notched shim plate 112 forming a plurality of separate heated air discharge channels located in spaced relation across the moving substrate material, a manifold may be constructed without a notched shim plate to provide an elongate continuous heated air discharge slot, with the cold air supply tubes 126 communicating with the continuous slot at spaced locations along the length of the manifold. In such an arrangement, the discrete stream or streams of heated air are formed by blocking selected portions of the elongate discharge slot with cold air, and multiple height patterning is accomplished by rapidly introducing small controlled amounts of cold air into the discharge stream or streams at selected locations along the slot to vary the temperature of the air striking the fabric.
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A method of producing surface height patterned materials by application of streams of pressurized, heated fluid into surface areas of a relatively moving material having thermally modifiable surface components. The heated fluid streams are selectively activated and deactivated in accordance with pattern information to strike selected surface areas of the material to thermally shrink and compact the surface areas by a desired amount. Heated fluid stream flow is controlled by use of cooler pressurized fluid which is selectively directed into the heated fluid stream flow to block the same from striking the surface of the moving material. The temperature of selected of the heated fluid streams striking the material is controllably varied by rapidly introducing small amounts of cooler fluid which blend into the heated streams to correspondingly vary the height reduction of the surface of the material.
The method is particularly suited for production of patterned pile fabrics containing thermoplastic pile yarn components, whereby the height of the pile yarns in the areas contacted by the streams may be reduced by varying amounts, depending upon the pattern-controlled introduction of cooler fluid into the heated fluid streams.
Multiple height, surface-patterned products produced by the aforementioned method are also disclosed.
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FIELD OF INVENTION
[0001] The present invention generally relates to protective headgear useful in rough stock riding. More particularly, this invention relates to lightweight protective headgear useful to riders of rough stock in rodeo competitions including bull riding, bareback horse riding, and bucking bronco riding.
BACKGROUND OF THE PRIOR ART
[0002] Rodeo competitors generally do not use protective headgear in rough stock riding competitions, including professional, collegiate, high school and youth rodeos. As such, rodeo competitors often suffer serious injuries to the head and face at distressingly high frequencies. These injuries are often caused by ground impact as a result of falling off the animals and collisions with the animals, which are endemic to the sport. Starting July 1995, the National High School Rodeo Association, the organization which governs high school rodeo competition, has strongly suggested that suitable headgear should be worn by rodeo rough stock competitors. The professional and collegiate rodeos may soon follow this suggestion upon its success.
[0003] The causes of head and face injuries that may be incurred in rough stock riding are well-known in the industry. These injuries include injuries to the head and face by high velocity ground impact when thrown from or falling off an animal, by being stomped on or horn hooked by an animal after a rider has fell or been thrown to the ground, by smashing a rider's face into the back of a bucking animal's head, by blows of an animal's horn to a rider's head, or by being hit in the head from a fence or chute gate. Each one of these, and particularly the combination of all of these types of injuries are particularly unique to the sport and require unique equipment to suitably protect a rider.
[0004] Protective headgears that are currently being produced for some sports, including bicycling, hockey, boxing, motorcycling, football, baseball, and lacrosse, are not suitable as a protective headgear for rodeo competition. Rodeo rough stock riding competition imposes unique requirements on protective headgear that is not satisfied by the currently available protective headgears. For example, baseball helmets typically only protect the side of a wearer's head. Hockey masks typically are provided with a clear faceplate that can render the helmet uncomfortably hot, particularly when worn in off-ice environments. The face guard of a hockey mask would hinder a rough stock rider's ability to perform because the rider would not be able to attain a chin tuck position, as needed by rough stock riders. Biking helmets typically protect only the top of a wearer's head. Finally, football and boxing helmets have gaps that leave a wearer's face partially exposed to objects that could poke through the gaps. The unique requirements of rough stock riding are likewise derived from the additional requirements that the rodeo competitor must compete effectively, there are weight limitations on the headgear so as to promote effective competition, and the protective headgear provides safety to the rider during competition. Currently available protective headgears are not suitable for rodeo competition because they interfere with the ability of the rider to compete effectively, they are too heavy, they have too many obstructions within the rider's field of vision, and they do not provide adequate protection from the animal's horns and hooves. Thus, there is a present need for protective headgear that is specifically designed for the rodeo rough stock riding competitor that not only protects the rider, but also permits the rider to feel unfettered and unrestricted so that the protective headgear does not diminish his performance.
SUMMARY OF THE INVENTION
[0005] The present invention is directed toward protective head gear which provides head protection for rodeo rough stock riding competitors without diminishing the rider's performance. The headgear of this invention is comprised of a lightweight and tough protective helmet, a lightweight, yet sturdy, detachable face guard which is firmly attached to the helmet but detaches when the face guard is caught by an animal's hoof or horn so as to avoid injuries caused by the twisting and pulling of the rider's neck and has horizontal bars spaced no more than approximately 1″, and preferably ⅞″, apart, and a hard shell chin guard that is optionally, but preferably, loosely attached to the face guard and has a shock absorbing foam insert.
[0006] The protective headgear of the present invention is distinguished from currently available protective headgears by several critical features which permit the rodeo competitor to compete without restricting or interfering with the rider's performance while continuing to protect the rider from head injuries caused by falls and collisions with the rough stock animal.
[0007] First, the face guard of the present invention does not protrude below the rider's chin. The required stance of the rodeo rough stock rider while mounted on the animal during the competition is to tightly tuck his chin down to his chest. Thus, the present invention allows the rider to tuck his chin tightly against his chest, in accordance with the required riding position.
[0008] Second, the face guard of the present invention has only one vertical bar in the rider's field of vision, the center vertical bar which bisects the face guard. The objects within the rider's field of vision must be minimized so that the rider's performance is not diminished. This center vertical bar of the present invention is necessary for additional support of the horizontal bars, such that the horizontal bars are not substantially flexed during the impact of an animal's horns. The only other vertical bars, the side vertical bars, are at the sides of the protective headgear, which corresponds to the location of the rider's temples. These side vertical bars have no impact in the rider's field of vision.
[0009] Third, the face guard of the present invention has more protective cage than the face guards of other currently available protective headgears, thereby protecting the rider's head area from impact on all sides. The cage of the present invention includes an angled out portion at its bottom area to allow the rider to attain the chin tuck position.
[0010] Significantly, the protective horizontal bars are spaced no more than approximately 1″, and preferably ⅞″, apart in order to stop a hoof or horn from entering the face guard. It has been found that in the sport of bull riding at all levels, whether professional, collegiate, high school, or youth, the end or tip of a bulls horn must be larger than the diameter of a half dollar, or approximately 1¼″ diameter.
[0011] The protective headgear of the present invention also includes a hard shell chin guard which is optionally, but preferably, loosely attached to the face guard and has a shock absorbing foam insert. Finally, the headgear's materials and components are selected so that the total weight of the headgear of the present invention is less than 40 ounces, preferably less than 30 ounces. According to the inventor's personal experience, rough stock riding performance deteriorates when the rider uses a protective headgear that weighs more than 40 ounces.
[0012] These and other features, aspects, and advantages of the present invention are presented in the following description, claims and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWING
[0013] FIG. 1 is a side perspective view of the headgear with the face guard and chin guard assemblies attached.
[0014] FIG. 2 is a detailed view of the attachment of the face guard assembly to the helmet.
[0015] FIG. 3 is a frontal perspective view of the headgear with the face guard and chin guard assemblies attached.
[0016] FIG. 4 is a detailed view of the straps used for the face guard and chin guard assemblies.
DETAILED DESCRIPTION OF THE INVENTION
[0017] As illustrated in FIG. 1 , the protective headgear of the present invention is comprised of a helmet 1 , a face guard 2 , and a chin guard 3 .
[0018] The helmet 1 of the present headgear invention can be the protective helmet used by ice hockey linesman produced by I-Tech Company or an equivalent helmet. The helmet 1 protects and encases the top, sides, and back of the rider's head including the top half of the rider's temple area and ears. Typically, the helmet 1 is molded from a light, but mechanically tough, and strong engineered polymer. The inside of the helmet 1 is typically lined with foam padding at appropriate locations to cushion the rider's head against impact shocks and blows. The helmet 1 typically weighs about 16 ounces.
[0019] Also as illustrated in FIG. 1 , the face guard 2 is a structurally rigid grid comprised of horizontal and vertical wire or bar stock, typically 3/16″ diameter titanium, or other suitable strong material, such as light metal or plastic bar stock. The horizontal bars are attached to the right and left sides of the frame 8 of the face guard. In one preferred embodiment, the horizontal and vertical bars are curved so that face guard 2 is shaped to fit over the rider's face such that it cups the rider's face and nose. The face guard 2 of the present invention has more protective cage than the face guards of other currently available protective headgears, thereby making the face guard 2 stronger and protecting the rider's head area from impact on all sides. The cage of the present invention includes an angled out portion at its bottom area to allow the rider to attain the chin tuck position. The face guard 2 has structural strength to protect the rider's face from high velocity ground impact when thrown from or falling off an animal, being stomped on or horn hooked by an animal after a rider has fell or been thrown to the ground, smashing of a rider's face into the back of a bucking animal's head, blows of an animal's horn into a rider's head, or being hit in the head by a fence or chute gate. If a face guard material that is prone to corrosion is selected, then it is preferred that the bar stock be treated or coated with a rust protective material, such as zinc, plastic, paint, or powder coat.
[0020] The face guard 2 has a horizontal bar spacing, the space between horizontal bars 10 and 11 , that does not exceed more than approximately 1″, and preferably ⅞″, apart. Typically, any horns of any bull used in competition at any level must be blunted to the size of a half dollar, or approximately 1¼″ diameter. The bar spacing of the instant invention would minimize the tip of a bull's horn from protruding into the face guard 2 to an extent that could harm a competitor. It has been found that any greater spacing than 1″ could permit a bull's horn, even blunted to 1¼″ diameter, to protrude sufficiently to contact the rider. The protective headgear of the present invention has only one center vertical bar 5 in the rider's line of sight, which vertically bisects the rider's face at his nose. Preferably, center vertical bar 5 is also curved to fit around a wearer's face. The center vertical bar 5 is attached to the frame 8 of the face guard and to each horizontal bar. Center vertical bar 5 inhibits objects, such as a bull's horn, that may protrude between all horizontal bars from substantially flexing said horizontal bars upon impact. The face guard 2 has vertical side bars 6 , 7 , other vertical bars, that are not located in the rider's line of sight. These vertical side bars 6 , 7 are formed as L shaped bars that are welded to the side and the top portion of the frame 8 of the face guard 2 . The vertical side bars 6 , 7 help brace the face guard 2 from a frontal or side impact blow in the event of a foreign obstacle striking the face guard with significant force.
[0021] Since the spacing between all horizontal bars shall not exceed more than approximately 1″, and preferably ⅞″, and the tip of a bull's horn must be equal to or greater than the size of a half dollar, approximately 1¼″ diameter, the face guard 2 with its vertical side bars 6 , 7 and its center vertical bar 5 would minimize harmful penetration of the tip of a bull's horn within the interior space of the protective headgear.
[0022] The total weight of the protective headgear is less than approximately 40 ounces, and preferably less than approximately 30 ounces. The helmet 1 weighs about 16 ounces, thus leaving about 14 to 24 ounces for the face guard 2 . The preferred material for the face guard 2 is 3/16″ titanium bar stock which provides adequate strength and adds only about 14 to 16 ounces to the protective headgear, making the total weight of the protective headgear about 30 to 32 ounces, which is ideal. Alternatively, but less preferable, steel bar stock may be used to construct the face guard 2 . The steel face guard 2 weighs about 20 to 24 ounces, which would make the total weight of the protective headgear about 36 to 40 ounces, which is still acceptable.
[0023] The face guard 2 is detachably attached to the helmet 1 . First, the face guard 2 is detachably attached to the helmet by straps 22 , 23 , which wrap around the bottom of vertical side bars 6 , 7 , using snap buttons 24 , 25 . These snap buttons 24 , 25 are located on the front side of straps 22 , 23 and attach to straps 22 , 23 . The back ends of straps 22 , 23 are detachably attached to the helmet 1 using belt buckle type fasteners which double as a female snap 26 , 27 . Second, additional straps 29 , 30 with snap buttons 14 , 15 , 16 a , 16 b are also used to detachably attach the face guard 2 to the helmet 1 . Snap buttons 14 , 15 are detachably attached to the end portion of straps 29 , 30 , once straps 29 , 30 have looped around the top side of the frame 8 of the face guard 2 . Snap buttons 16 a , 16 b are detachably attached to the top potion of helmet 1 . Finally, the frame 8 of the face guard 2 is also removably secured to stabilizer brackets 20 , 21 . The stabilizer brackets 20 , 21 are preferably made of a strong stainless steel material designed with a gripping pinching force to stabilize the face guard 2 near the temporal regions at the top on both sides of the frame 8 of the face guard 2 . If the rider becomes dislodged and the face guard 2 is hooked by the animal's horns or entangled in the animal's hooves causing the jerking motion of the rider's head, the face guard 2 would detach from the helmet 1 by automatically unsnapping snap buttons 24 , 25 , 26 , 27 , as a result of the jerking motion, so that straps 22 , 23 , 29 , 30 can slide away from the helmet 1 and the face guard 2 automatically is removed from stabilizer brackets 20 , 21 . This detachable feature precludes injuries to the rider's neck caused by the jerking motions.
[0024] Finally, the chin guard 3 is made of hard shell plastic and a suitable shock resistant compressible foam insert that is mounted inside the chin guard 3 . The chin guard 3 is loosely and adjustably secured to the face guard 2 by two or more adjustable straps 41 , 42 that fit around vertical side bars 6 , 7 at the lower right and left sides of the face guard 2 .
[0025] While the preferred embodiment of the present invention and its advantages have been described in detail, it is appreciated that various changes, substitutions and alterations can be made without departing from the scope and spirit of the invention as defined by the following claims.
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A protective headgear specifically for rodeo rough stock riding competition that protect the riders from serious injuries to the head and neck area. The protective headgear includes a helmet, a detachable face guard having horizontal bars spaced no more than approximately 1″, and preferably, ⅞″ apart, and a hard shell chin guard that preferably is loosely and adjustably attached to the face guard. Features of the protective headgear that make it suitable for rodeo competition include a detachable face guard that does not protrude below the chin to permit the rider to assume the required rough stock riding position in which the rider tucks his chin firmly down into his chest and horizontal bars with spacing that does not exceed approximately 1″, and preferably, ⅞″ apart.
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FIELD OF THE INVENTION
[0001] The present invention relates to adhesive materials and in particular to an adhesive material for bonding of glass to glass
[0002] The invention has been developed primarily for use of bonding glass smooth plates and will be described hereinafter with reference to this application. However, it will be appreciated that the invention is not limited to this particular field of use.
BACKGROUND OF THE INVENTION
[0003] Glass is a nonporous adherend, and therefore adhesive products in the market, which contain water or solvent will not be suitable for glass bonding applications.
[0004] The UV curable and heat-setting resin adhesives are widely used. These can be used for glass adhesive bonding. In specialist locations such as dentist surgeries or laboratories or in specialist glass engineering workshops such UV sources are available as an expensive time directional beam apparatus. However in a general sense this is commercially not feasible as it is not possible to sell a UV source with every tube of adhesive sold in the market for home or industrial users.
[0005] Further the UV curable and heat-setting resin adhesives are not generally eco-friendly and are permanent.
[0006] The present invention seeks to provide an improved adhesive, which will overcome or substantially ameliorate at least one or more of the deficiencies of the prior art, or to at least provide an alternative.
[0007] It is to be understood that, if any prior art information is referred to herein, such reference does not constitute an admission that the information forms part of the common general knowledge in the art, in Australia or any other country.
SUMMARY OF THE INVENTION
[0008] According to a first aspect of the present invention, a new adhesive is provided by a Hotmelt Phosphazene-Based Clear Adhesive Material (PN-CAM) comprising: a) Hexachlorocyclotriphosphazene; b) Bisphenol A; and c) methyl 4-hydroxybenzoate. Preferably the equation of relative amounts of each component in mole ratio for the PN-CAM is substantially: (a:b:c) is [1:1:4].
[0009] Preferably the Hotmelt phosphazene-based clear adhesive material has the Bisphenols molecule link cyclotriphosphazene molecules and preferably the aromatic ester groups directly bond to cyclotriphosphazene molecules.
[0010] According to a second aspect of the present invention, a new adhesive is provided by Hotmelt phosphazene-based clear adhesive material wherein the PN-CAM is fine powder, low porosity and low flow properties wherein the product is transportable and usable with addition of low intensity heat to form a glass to glass transparent bond. Preferably the PN-CAM in glass to glass bond is recyclable back to a fine powder, by a solvent wherein the product is re-usable with addition of low intensity heat to form a glass to glass transparent bond.
[0011] The new adhesive can be used for inclusion of this product PN-CAM in the bonding of two glass surfaces including the steps of:
i) Clean all glass surfaces, and ensuring they are dry, smooth and structurally sound. ii) Apply the product PN-CAM to the glass to be bonded iii) Expose the glass surface to source of heat till the powder melts and flows; iv) Force the second glass plate placed on top of the molten, against the other glass plate to remove all trapped air. v) Leave the bonded glass plates to cool down to room temperature.
[0017] The invention also provides a method of forming hotmelt phosphazene-based clear adhesive material including the steps of:
i) adding a solution of bisphenol dropwise over a short period to a stirring solution of hexachlorocyclotriphosphazene. ii) Stirring the mixture for extended period iii) subjected to refluxing condition over a short period iv) Filtering off preciptitated salt with the filtrate evaporated to dryness under reduced pressure. v) dissolving the obtained material in distilled 1,4-dioxane vi) adding in drops to sodium 4-methoxycarbonylphenoxide formed from the reaction of methyl 4-hydroxybenzoate and sodium hydride refluxed in 100 mL of 1,4-dioxane for extended period vii) refluxing the combination with continuous stirring for extended period. viii) Removing formed sodium chloride and the filtrate evaporated to dryness. ix) Reconstituting the residue in methylene chloride and the resulting solution washed with distilled water x) receiving and drying the organic layer over anhydrous MgSO4, with the solution filtered and the solvent removed under reduced pressure. xi) Drying the product in vacuum oven
wherein a faint yellow to colorless transparent solid Hotmelt Phosphazene-Based Clear Adhesive Material (PN-CAM) material with a percentage yield of 90% was obtained.
[0029] It can be seen that the invention provides the benefit of PN-CAM being a hot-melt adhesive used for adhering glass-glass smooth plates, no treatment such as chemical etching or sandblasting is required to be made at the surface of the glass before applying the adhesive. This is a very specialized glass adhesive material that can be reusable, it is possible to use it again and again and again (just heat collect and apply) recycling process (no product in the market possesses such feature), other glass adhesive product in the market require extra attention during application because once they are dried (cured), they are permanent.
[0030] PN-CAM provides good adhesive strength, high optical transparency for bonded glass plates where a very thin adhesive layer of about 0.016 mm is applied between the plates.
[0031] PN-CAM possess unique adhesive properties such as odorless, colorless, transparent, solvent- and fillers-free, thermoplastic, moderate melting (softening) temperature, durable and uncross-linkable. These conditions are seldom met by commercially available adhesive polymeric materials, where most of them are cross-linkable and don't afford an ability of dis-bonding and re-bonding after setting and often contain carcinogenic materials and/or solvents.
[0032] PN-CAM is thermally stable and it is resistance to the mooxidative degradation up to 380° C.
[0033] PN-CAM is a UV light resistance and it has a long-term durability i.e. no yellowing or photodegradation observed when it is exposed to intensive wavelength of Ultraviolet (U.V) light (covering the λ 313 nm) for about 600 hours then the PN-CAM provides high optical transparency in the visible wavelengths at the range of 400-700 nm.
[0034] PN-CAM when applied between two glass plates it shows void-free and invisible glueline between the bonded glass plates. PN-CAM is a water proof adhesive.
[0035] PN-CAM is soluble in common organic solvents, such as acetone, methyl ethyl ketone, 1,4-dioxane, tetrahydrofuran, chloroform, methylene chloride, tetrachlorocarbon, benzene and toluene.
[0036] PN-CAM provides excellent adhesive strength for bonding smooth glass plates, (the adhesive strength exceeds substrate strength, i.e. the bond was stronger than the glass).
[0037] Unlike other product in the market, this product is solvent free and its eco-friendly.
[0038] Other aspects of the invention are also disclosed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0039] Notwithstanding any other forms which may fall within the scope of the present invention, a preferred embodiment/preferred embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings in which:
[0040] FIG. 1 is a chemical equation of a resultant Hotmelt Phosphazene-Based Clear Adhesive Material (PN-CAM) in accordance with a preferred embodiment of the present invention;
[0041] FIG. 2 is a chemical equation diagrammatic synthesis steps of products of FIG. 1 ;
[0042] FIG. 3 is a diagrammatic flow diagram of synthesis steps of FIG. 2 ;
[0043] FIG. 4 is a FTIR spectrum of product created from synthesis steps of FIG. 2 ;
[0044] FIG. 5 is a 31 P NMR spectrum of product created from synthesis steps of FIG. 2 ;
[0045] FIG. 6 is a 1 H NMR spectrum of product created from synthesis steps of FIG. 2 ;
[0046] FIG. 7 is a 13 C NMR spectrum of product created from synthesis steps of FIG. 2 ;
[0047] Table 1 is a FTIR, 1 H-NMR spectral data, and other properties of product created from synthesis steps of FIG. 2 ;
[0048] Table 2 is a 13 C NMR spectral data of product created from synthesis teps of FIG. 2 ;
[0049] FIG. 8 is a DSC thermogram of product created from synthesis steps of FIG. 2 ;
[0050] FIG. 9 : TG curve of product in N 2 gas created from synthesis steps of FIG. 2 ;
[0051] FIG. 10 is a TG curve of product in O 2 gas created from synthesis steps of FIG. 2 ;
[0052] Table 3 is a summary of the thermal properties of product in N 2 and O 2 Gas created from synthesis steps of FIG. 2 ;
[0053] FIG. 11 is a FTIR spectra of samples UV-irradiated with a HPM-15 lamp for different irradiation times
[0054] Table 4 is a test result of adhesive strength of product over glass specimen
[0055] Table 5 is a test result of optical properties of product at various wavelengths
[0056] FIG. 12 is a UV-vis spectra of the blank microscopic slide and adhesive product created from synthesis steps of FIG. 2 ;
[0057] FIG. 13 is a diagrammatic view of a plurality of glass plates being bonded by the resultant Hotmelt Phosphazene-Based Clear Adhesive Material (PN-CAM) in accordance with a preferred embodiment of the present invention
[0058] FIG. 14 is a diagrammatic view of an example of use of bonded glass to glass plates such as for spectacles and bifocals or trifocals by altering optics with different shaped plates.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0059] The general chemical molecular structure for the final product shown in FIG. 1 which we gave a name as: the Hotmelt Phosphazene-Based Clear Adhesive Material (PN-CAM) has the main three components for PN-CAM are a) Hexachlorocyclotriphosphazene b) Bisphenol A c) methyl 4-hydroxybenzoate. The equation of relative amounts of each component in mole ratio for the PN-CAM is (a:b:c) is [1:1:4].
[0060] The range of composition for main ingredients of the hotmelt phosphazene based clear adhesive material (PN-CAM) that still work to form effective PN-CAM is the range in mole ratio of (a:b) that still can be worked is [1:1.20] meaning about 20% excess for material Bisphenol A (component b).
[0061] The adequate amount of component (c), means the amount that is enough to make component (a) is fully substituted. Theoretically four moles of component (c) is an optimal amount that makes one mole of component (a) is fully substituted. For this step we can use even more than 4 moles and the excess will never effect the reaction. This because component (a) will never react (takes) more than four moles of component (c) to make the former fully substituted (see the molecular structure of phosphazene-base clear adhesive material, given in FIG. 1 ).
[0062] Synthesis of Hotmelt Phosphazene-Based Clear Adhesive Material
[0063] As shown in FIGS. 1 and 2 the Synthesis of Phosphazene-based clear adhesive material is generally undertaken by the steps of firstly adding a solution of bisphenol dropwise over a short period to a stirring solution of hexachlorocyclotriphosphazene and stirring the mixture for extended period.
[0064] Second step is to subject to refluxing condition over a short period, filtering off precipitated salt with the filtrate evaporated to dryness under reduced pressure and dissolving the obtained material in distilled 1,4-dioxane.
[0065] A third, step is to add in drops to sodium 4-methoxycarbonylphenoxide formed from the reaction of methyl 4-hydroxybenzoate and sodium hydride refluxed in 100 mL of 1,4-dioxane for extended period.
[0066] Fourthly reflux the combination with continuous stirring for extended period.
[0067] A fifth step is to remove formed sodium chloride and the filtrate evaporated to dryness. Reconstitute the residue in methylene chloride and the resulting solution washed with distilled water and receive and dry the organic layer over anhydrous MgSO4, with the solution filtered and the solvent removed under reduced pressure.
[0068] Finally drying the product in vacuum oven to obtain solid Hotmelt Phosphazene-Based Clear Adhesive Material (PN-CAM)
[0069] Looking at the process in more detail, to a stirring solution of hexachlorocyclotriphosphazene (PN) (10.0 g 0.02 mol) in 100 mL of freshly distilled THF (inside a 250 mL 2-necked round bottom flask fitted with a reflux condenser, a magnetic stirrer, and placed in an oil bath).
[0070] A solution of bisphenol A (7.07 g, 0.023 mol) in 50 mL of freshly distilled THF and triethylamine (17.0 mL, 0.12 mol) was added dropwise via a dropping funnel over a period of 15 minutes.
[0071] The content of the flask stirred for 10 hours and subsequently, subjected to refluxing condition for 30 minutes.
[0072] Triethylamine hydrochloride salt that precipitated was filtered off. The filtrate was evaporated to dryness under reduced pressure.
[0073] The obtained material was dissolved in 100 mL freshly distilled 1,4-dioxane and carefully added via a dropping funnel to sodium 4-methoxycarbonylphenoxide formed from the reaction of methyl 4-hydroxybenzoate (12.78 g, 0.08 mol) and sodium hydride (2.0 g, 0.08 mole) refluxed in 100 mL of 1,4-dioxane for 2 hours
[0074] The content of the flask was refluxed with continuous stirring for 10 hours.
[0075] Sodium chloride that formed was removed by suction filtration and the filtrate evaporated to dryness.
[0076] The residue was reconstituted in 200 mL of methylene chloride and the resulting solution washed with distilled water (75 mL).
[0077] The organic layer was received and dried over anhydrous MgSO 4 , the solution was filtered and the solvent removed under reduced pressure.
[0078] The product was then dried at 100° C. in vacuum oven for 2 hours.
[0079] A Faint yellow to colorless transparent solid material with a percentage yield of 90% was obtained.
[0080] Structural Analysis of Product
[0081] As detailed FIGS. 2 and 3 show the synthesis steps in forming the Phosphazene-based clear adhesive material of FIG. 1 .
[0082] The particular characteristics of this material as formed by the defined process provides a material with unexpected properties that make it particularly useful in the glass to glass bonding process.
[0083] in The FTIR spectrum of product depicted in FIG. 4 shows the characteristic bands of the phosphazene ring, mainly at 1273, 1211 cm −1 assigned to the asymmetric and symmetric stretching of P═N group, respectively and at 1161 cm −1 assigned to the stretching PO—C bond (of PO—Ar groups). The absorption frequencies of C═O appeared at 1720 cm −1 .
[0084] The 31 PNMR spectrum reveals a single broad resonance at δ 9.2 ppm as shown in FIG. 5 , which indicates a complete replacement of the residual chlorines by ester groups.
[0085] Assignments of the related peaks in the FTIR, 1 H NMR spectrum ( FIG. 6 ), and other data of the product are given in Table 1, and 13 C NMR spectrum given in FIG. 7 and data are tabulated in Table 2.
Thermal Analysis
[0086] DSC analysis: The sample was annealed at heating rate of 10° C./min (for both heating and cooling). For the first scan, the sample was heated from −20° C. to at least 200° C. and hold for about 3 minutes before cooled (at 10° C./min) back to −20° C. The second scan was performed after 2-3 minutes of waiting time then heated up to 200° C.
[0087] The glass transition temperatures (Tg) was determined from the inflection point of the DSC thermogram of the second scan. The thermogram in FIG. 8 shows clear sole endothermic transitions appeared at 63° C. corresponding to Tg.
[0088] The thermal gravimetric analysis (TGA) curve in atmosphere of nitrogen and oxygen gas showed good thermal stability, indicated by the absence of any significant weight loss up to 350° C. as illustrated in FIGS. 9 and 10 .
[0089] In both atmospheres, the thermograms showed one major decomposition step occurred at 380° C., this indicate that the product is thermally very stable even under tough conditions of stream oxygen gas.
[0090] The total weight loss under nitrogen and oxygen were 53% and 60% respectively. A summary of the thermal analysis data is presented in Table 3.
Photo Stability
[0091] Referring to FIG. 11 , the UV irradiation process of product was performed on a weatherometer (type Q-Panel) with a low-pressure mercury (LPM) lamp (type UVB-313 EL made in USA, 40 w, the main emission wavelength covered the 313 nm range).
[0092] The FTIR spectra of product after long time of irradiation by UV light (100, 200, 300, and 600 hrs) does not show any changes of the characteristics peaks in comparison to the spectrum before irradiation. The carbonyl peak of the ester groups at 1725 cm −1 was not shifted or changed, also no new peak was observed in the spectra indicating that there are no changes in the microstructure of the product even with increasing UV-irradiation time to 600 hours.
Tensile Shear Strength
[0093] Measurements of the tensile shear strength (adhesive strength) of a single-lap bonded joint was carried out according to the standard DIN EN 1465 using INSTRON 1195 Tensiometer with pulling rate of 2 mm/min and maximum applied force of 200 kg at room temperature using glass test plates with the dimensions of (100×25 mm).
[0094] As shown in FIG. 13 , the thickness of the adhesive layer between the two glass plats was found to be ≈0.016 mm (±0.003 mm) for all specimens and an average of five readings was taken for calculating the (Fmax) value with standard deviation of ≈±6.60.
[0095] The adhesive strength was found to be 3.74 MPa, this strength of bonded joint is likely, due to the interaction surface between the active hydroxy sites on glass with the polar methoxycarbonylphenoxy group, data are given in Table 4.
Optical Characteristics
[0096] Hotmelt Phosphazene-based clear adhesive material exhibits good optical transparency at various wavelengths as illustrated in Table 5. The UV cut-off wavelength (λ cut-off ) of the blank microscopic slides ref. (used as a reference for comparison) at 289 nm whereas that of product was about 300 nm and its wavelength of 80% transparency (λ 80% ) was 364 nm.
[0097] In comparison to the transparency of blank slid, the maximum transparency of at least 90% was observed within the wavelengths of the visible light at the range of 400-700 nm, as shown in FIG. 12 , also given in this spectrum the spectrum of the blank microscopic slide as a reference for comparison and other spectroscopic data are given in Table 5.
Alternative Synthesis Procedures for PN-CAM:
[0098] The First Alternative Method of Preparation (Procedure)
[0099] To a stirring solution of hexachlorocyclotriphosphazene (PN) (10.0 g, 0.02 mol) in of freshly distilled THF (inside a 250 mL 2-necked round bottom flask fitted with a reflux condenser, a magnetic stirrer, and placed in an oil bath).
[0100] A solution of bisphenol A (7.07 g, 0.023 mol) in 50 mL of freshly distilled THF and triethylamine (17.0 mL, 0.12 mol) was added dropwise via a dropping funnel over a period of 15 minutes.
[0101] The content of the flask stirred for 10 hours and subsequently, subjected to refluxing condition for 30 minutes.
[0102] Triethylamine hydrochloride salt that precipitated was filtered off. The filtrate was evaporated to dryness under reduced pressure.
[0103] The obtained product was dissolved in 100 mL of freshly distilled 1,4-dioxane inside a 250 mL round bottom flask and then a solution of methyl 4-hydroxybenzoate (12.78 g, 0.084 mol) of and triethylamine (34 mL, 0.24 mol) in 50 ml of 1,4-dioxane was added via a dropping funnel over a period of 10 minutes. The content of the flask was refluxed with continuous stirring for 30 hours.
[0104] The triethylamine hydrochloride salt that formed was removed by suction filtration and the filtrate evaporated to dryness.
[0105] The residue was reconstituted in 150 mL of methylene chloride and the resulting solution washed with distilled water (75 mL).
[0106] The organic layer was received and dried over anhydrous Na 2 SO 4 , the solution was filtered and the solvent removed under reduced pressure.
[0107] The solid product was washed with hot methanol. The product was then dried at 100° C. under reduced pressure (0.03 Torr) for 6 hours.
[0108] A Faint yellow solid material with a percentage yield of 80% was obtained.
[0109] The Second Alternative Method of Preparation (Procedure)
[0110] Bisphenol A (7.07 g, 0.023 mol) and sodium metal or sodium hydride (1.0 g, 0.046 mol) in 50 mL of dry THF was stirred and refluxed for three hours inside a 200 mL round bottom flask fitted with a reflux condenser, a magnetic stirrer, and placed in an oil bath. The di-sodium salt of Bisphenol A formed after 3 hours of stirring and refluxing, then the content of the flask was cooled down to room temperature.
[0111] To this mixture (di-sodium salt of Bisphenol A) a solution of hexachlorocyclotriphosphazene (10.0 g, 0.02 mol) in 50 mL of freshly distilled THF was added portion wise.
[0112] The content of the flask stirred for two hours and then subjected for refluxing conditions for 10 hours
[0113] The Sodium chloride that formed was removed by suction filtration and the filtrate evaporated to dryness.
[0114] The obtained product was dissolved in 100 of freshly distilled 1,4-dioxane inside a 250 mL round bottom flask and a solution of methyl 4-hydroxybenzoate (35.01 g, 0.23 mol) and triethylamine (48 mL, 0.34 mol) in 50 ml of 1,4-dioxane was added via a dropping funnel over a period of 10 minutes. The content of the flask was refluxed with continuous stirring for 30 hours.
[0115] The residue was reconstituted in 150 mL of methylene chloride and the solution washed with distilled water (75 mL).
[0116] The organic layer was received and dried over anhydrous Na 2 SO 4 , the solution was filtered and the solvent removed under reduced pressure.
[0117] The solid product was washed with hot methanol. The product was then dried at 100° C. under reduced pressure (0.03 Torr) for 6 hours.
[0118] A Faint yellow solid material with a percentage yield of 80% was obtained.
[0119] Note here that in all reaction steps the solvents THF and 1,4-dioxane were dried over sodium metal and freshly distilled before used.
[0120] Use of the Material
Example 1
Use as Glass Bonding
[0121] Installation of this product PN-CAM (procedure for application) in a particular form and in a particular way starts with all glass surfaces must be clean, dry, smooth and structurally sound. For every 10 cm2 apply 50 mg powder (PN-CAM) (5 mg cm2). Expose the glass surface to source of heat (light burner such as cigarette lighter) between 200°-350° C. while the heat source exposed to the glass surface (bottom), and on top still the powder (melt and flow). Because this product is amorphous therefore, we cannot define the melting point. When the second glass plate placed on top of the molten, the two plates will be twisted with force against each other to remove all trapped air (air bubbles). Leave the bonded glass plates to cool down to room temperature.
[0122] In the recycling process: To recover the adhesive material, center the two plates over the burner till the two plates separated, then immerse the plats for few minutes in any common solvent such as acetone, THF, chloroform, methylene chloride, methyl ethyl ketone, then evaporate the solvent under reduced pressure and collect the adhesive powder again PN-CAM.
[0123] Adhesives for bonding glass and related substrates are selected based on polarity, available functional groups, and compatibility. The polymeric materials used to bond glass are generally transparent, colorless and do not change the optical characteristics of the glass, heat-setting resins, thermally stable, water and UV resistant, fillers and solvent free.
[0124] Because glass is a non-porous adherend, therefore, any adhesive containing water or solvent will not be suitable for bonding applications.
[0125] The most useful polymeric adhesive materials are polyvinyl butyral, phenolic butyral, phenolic nitrile, styrene-modified polyesters and styrene monomer based adhesives, thermosetting epoxies and acrylics are also used. Most of glass adhesive bonding materials are either UV curable or heat setting resin.
[0126] Most of the glass adhesive resins are either cross-linked or thermosets when cured, therefore after setting, their ability for disbonding and rebonding virtually becomes almost impossible. This because, the chemical structure as well as the molecular weight and composition of the polymer materials are altered when they subjected to curing conditions.
[0127] Hotmelt Phosphazene-based clear adhesive material doesn't contain cross-linkable terminal groups at it structure; therefore the product neither undergoes crosslink reaction nor changes of the molecular structure or degradation of the molecular weight when they subjected to curing conditions.
[0128] Phosphazene-based clear adhesive material is a hot-melt adhesive used for adhering glass-glass smooth plats, no treatment such as chemical etching or sandblasting is required to be made at the surface of the glass before applying the adhesive.
[0129] Hotmelt Phosphazene-based clear adhesive material:
a) provides good adhesive strength, high optical transparency for bonded glass plates where a very thin adhesive layer of about 0.016 mm is applied between the plates. b) possesses unique adhesive properties such as odorless, colorless, transparent, solvent- and fillers-free, thermoplastic, moderate melting (softening) temperature, durable and uncross-linkable. These conditions are seldom met by commercially available adhesive polymeric materials, where most of them are cross-linkable and don't afford an ability of dis-bonding and re-bonding after setting. c) is thermally stable and it is resistance to thermooxidative degradation up to 380° C. d) is a UV light resistance and it has a long-term durability i.e. no yellowing or photodegradation observed when it is exposed to intensive wavelength of Ultraviolet (U.V) light (covering the λ 313 nm) of for about 600 hours e) provides high optical transparency in the visible wavelengths at the range of 400-700 nm. f) when applied between two glass plates it shows void-free and invisible glueline between the bonded glass plates. g) is a water proof adhesive. h) is soluble in common organic solvents, such as acetone, methyl ethyl ketone, 1,4-dioxane, tetrahudrofuran, chloroform, methylene chloride, tetrachlorocarbon, benzene and toluene. i) provides excellent adhesive strength for bonding smooth glass plates, (the adhesive strength exceeds substrate strength, i.e. the bond was stronger than the glass). j) bonded mechanism to the glass plates is based on the surface interaction between the active polar sites on glass with the polar groups present in chemical structure of the adhesive material. k) is specifically used for bonding (adhering) glass-glass surfaces.) l) has paramount importance for specific glass industrial applications such as bonding of lenses, photo frames, decorative glass bevel windows, liquid crystals displays and glass display cabinets. m) can be used to glue glass on glass, as in mosaics, or for simply fixing broken glass. This adhesive is ideal for crystal, and both clear and colored glass. n) comes off of skin easily and will not glue fingers together like many super glues. This is the ideal glue for glass if children will be doing the gluing o) is safe to use compare to other commercially available adhesive materials in the market especially those containing volatile carcinogenic solvents. p) is Eco friendly and can be simply recovered after use by dissolving it into suitable solvent yet maintaining its original properties. q) manufacturing procedure is cheap and can be easily produced in industrial scale
Examples
[0147] The new adhesive material can be used for several applications including for replacement a cracked screen (with—without) digitizer for, iphones, Ipad, samsung galaxy S3, tablets and others. (The screen/glass part, it doesn't look like it is glass but for Samsung S3 it is glass). The transparency after use will be almost 90%. This can be achieved by melting/softening the adhesive glue powder.
[0148] A second use is for spectacles as shown in FIG. 14 . These days, most people choose line-free progressive lenses, conventional bifocals and trifocals have some advantages over progressives. In particular, bifocal and trifocal lenses usually provide wider lens areas for reading and computer work than progressive lenses. Also, there are many special-purpose bifocal and trifocal lens designs available, including special glasses for computers.
[0149] A third use is for manufacturing a water tight containers such as Home aquarium or to glue glass on glass, as in mosaics, or for simply fixing broken glass. This adhesive is ideal for crystal, and both clear and colored glass. It comes off of skin easily and will not glue fingers together like many super glues.
[0150] Glass Patch clear adhesive film can be formed that holds broken glass together for safer and more secure place such as classrooms.
Interpretation
Embodiments
[0151] 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.
[0152] Similarly it should be appreciated that in the above description of example 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 of Specific Embodiments are hereby expressly incorporated into this Detailed Description of Specific Embodiments, with each claim standing on its own as a separate embodiment of this invention.
[0153] 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.
Different Instances of Objects
[0154] As used herein, unless otherwise specified the use of the ordinal adjectives “first”, “second”, “third”, etc., to describe a common object, merely indicate that different instances of like objects are being referred to, and are not intended to imply that the objects so described must be in a given sequence, either temporally, spatially, in ranking, or in any other manner.
Specific Details
[0155] 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.
TERMINOLOGY
[0156] In describing the preferred embodiment of the invention illustrated in the drawings, specific terminology will be resorted to for the sake of clarity. However, the invention is not intended to be limited to the specific terms so selected, and it is to be understood that each specific term includes all technical equivalents which operate in a similar manner to accomplish a similar technical purpose. Terms such as “forward”, “rearward”, “radially”, “peripherally”, “upwardly”, “downwardly”, and the like are used as words of convenience to provide reference points and are not to be construed as limiting terms.
Comprising and Including
[0157] In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word “comprise” or variations such as “comprises” or “comprising” are used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.
[0158] Any one of the terms: including or which includes or that includes as used herein is also an open term that also means including at least the elements/features that follow the term, but not excluding others. Thus, including is synonymous with and means comprising.
Scope of Invention
[0159] Thus, while there has been described what are believed to be the preferred embodiments of the invention, those skilled in the art will recognize that other and further modifications may be made thereto without departing from the spirit of the invention, and it is intended to claim all such changes and modifications as fall within the scope of the invention. For example, any formulas given above are merely representative of procedures that may be used. Functionality may be added or deleted from the block diagrams and operations may be interchanged among functional blocks. Steps may be added or deleted to methods described within the scope of the present invention.
[0160] Although the invention has been described with reference to specific examples, it will be appreciated by those skilled in the art that the invention may be embodied in many other forms.
INDUSTRIAL APPLICABILITY
[0161] It is apparent from the above, that the arrangements described are applicable to the adhesives and bonding industries.
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The present invention relates to preparation of clear adhesive material. The Phosphazene-based clear adhesive material which comprised of cyclophosphazene, biphenols and aromatic ester groups possess especial optical and thermal characteristics. When adequate amount of Phosphazene-based clear adhesive material applied between two glass surfaces, it affords high optical transparency of at least 90% in the visible wavelengths at the range of 400-700 nm and good adhesive strength, thermo and photo oxidative stability. Phosphazene-based clear adhesive material is a thermoplastic and it offers a possibility of repeatedly disbonding and re-bonding of glass plats once exposed to heat.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an image display device, more particularly to a head mounted display device.
2. Description of Related Art
In conventional arts, various types of head mounting devices (HMD) have been proposed, as shown in “Journal of Nippon Virtual Reality Society”; “Special issue on HMD”, December 1998, Vol. 3, No. 2, pages 5 to 41, for example. They are largely classified in two types: one is an eyepiece optical type comprising a display element and eyepiece lenses that magnifies it directly; another is an eyepiece relay type by which a displayed image is focused once by a relay optical system and then the imaging surface is magnified by an eyepiece lens system. Eyephone 02 sold by VPL Company magnifies and displays an LCD (liquid crystal display element) in 86,000 pixels and thereby realizes 80 degree of the field angle for the purpose of wider field angle. However, the LCD in 86,000 pixels is not sufficient in view of resolution.
Further, other devices are proposed such as a device with 50 degree of the field angle by eccentric optical system in which a concave mirror is used and a device developed by Canon Corporation that realizes 43.5 degree of the field angle by an eyepiece relay system in which a free curved prism is used for a mirror. Olympus Optics Company also realizes 80 degree of the field angle for which a sheet of eccentric concave mirror is used. Further, Datavisor 80 by N-Vision Company as a HMD with wide field of view and high resolution realizes 80 degree in one eye and 120 degree in both eyes of the field of view. Also other example realizes 100 degree of the field of view by using two LCDs for one eye.
An example in Nara, Ifukube, Ino, Takahashi, and Yamamoto: “Affect on posture control by sight movement stimulus by wide field of view HMD” in papers of Nippon Virtual Reality Society, 1996, Vol. 1, pages 33 to 39 realizes 140 degree of the field of view by an eyepiece optical system by using two LCDs for one eye. However, it is said that field of view of human is 150 degree by one eye and 180 degree or more by both eyes horizontally. Therefore, the conventional studies mentioned above have not offered sufficient field of view.
An example in Inami, Kawakami, Yanagida, Maeda, and Tachi: “Wide field view stereoscopic display by Maxwell optical system” in papers of Nippon Virtual Reality Society, 1999, Vol. 4, No. 1, pages 287 to 294 realizes 110 degree of the maximum field of view in one eye by Maxwell optical system in which a half mirror and concave mirror are used, thereby wider field is given in comparison with the conventional art mentioned above. In this optical system, however, has a problem that, since a diameter of pupil affects the field of view, the brighter becomes a light source, the narrower becomes the field of view because of contraction of the diameter of the pupil.
SUMMARY OF THE INVENTION
As described above, it is pointed out as one of the problems that the field of view according to the head mounted display devices currently used is narrow. Therefore, an object of the present invention is to realize a head mounted display device with 120 degree of the field of view in one eye and 180 degree or more in both eyes horizontally while keeping at least the resolution same with the conventional art.
The wide field of view head mounting device according to the present invention includes: a display element displaying an image; a dioptric system for projecting a displayed image on said display element, and a catoptric system with a concave mirror and convex mirror, wherein said display element, said dioptric system and said catoptric system are arranged in a relative relationship in such a manner that a light of the displayed image on said display element is projected to said convex mirror through said dioptric system, a reflected light of the projected light on said convex mirror arrives at said concave mirror as an incident light, and a virtual image of a beam of reflected light of the incident light on said concave mirror is observed at a predetermined position for an observing pupil.
The wide field of view head mounted display device according to the present invention can realize a wide field of view in a compact device since the light of the displayed image on the display element is projected on the convex mirror through the dioptric system, and then the reflected light of the projected light on the convex mirror arrives as an incident light at the concave mirror allowing the wide field of view, and a virtual image of the beam of reflected light of the incident light on the concave mirror is observed at the predetermined position for the observing pupil In this connection, said concave mirror and convex mirror can be lightened if the mirror is made of an acrylic resin polished to mirror finish, for example.
In the wide field of view head mounting device according to the present invention, said convex mirror may be a mirror of hyperboloid of two sheets and either focus point of the mirror of hyperboloid of two sheets may be at a position of a lenticular principal point of said dioptric system. Further, said convex mirror may be a parabolic mirror and a projected light from said dioptric system may consists of parallel rays of light, or said convex mirror may be a spherical mirror. Furthermore, according to the wide field of view head mounted display device of the present invention, said concave mirror may be a spherical mirror and said convex mirror may be a half mirror, or said concave mirror may be an ellipsoidal mirror.
Further, the wide field of view head mounted display device of the present invention may be equipped with a physical relationship changing means to change at least two relative optical positions of said display element, said dioptric system and said catoptric system, whereby at least two relative optical positions of said display element, said dioptric system and said catoptric system can be adjusted to present a fine image.
According to the wide field of view head mounted display device of the present invention, a half mirror may be placed between said display element and said dioptric system and also an imaging element may be placed to pick up an image of said observing pupil corresponding to the half mirror. With such a constitution, an image can be presented without any effect of eclipse by an iris around a pupil due to change of the position of observing pupil, by changing at least two relative optical positions of the display element, dioptric system, and catoptric system by said physical relationship changing means.
BRIEF DESCRIPTION OF DRAWINGS
FIGS. 1 a and 1 b an explanatory views respectively showing a device of example 1 according to the present invention viewed from a side and upper direction;
FIGS. 2 a and 2 b arm explanatory views respectively showing a device of example 2 according to the present invention viewed from a side and upper direction;
FIGS. 3 a and 3 b are explanatory views respectively showing a device of example 3 according to the present invention viewed from a side and upper direction;
FIGS. 4 a and 4 b are explanatory views respectively showing a device of example 4 according to the present invention viewed from a side and upper direction;
FIGS. 5 a and 5 b are explanatory views respectively showing a device of example 5 according to the present invention viewed from a side and upper direction;
FIGS. 6 a and 6 b are explanatory views respectively showing a device of example 6 according to the present invention viewed from a side and upper direction;
FIG. 7 a is an explanatory view showing a device of example 7 according to the present invention viewed from a side, and FIG. 7 b is an explanatory view showing the movement of the lens 2 of the device of example 7 according to the present invention viewed from an upper direction;
FIG. 8 is an explanatory view showing an essential part of a device of example 8 according to the present invention viewed from a side direction;
FIG. 9 a is an explanatory view showing a device of example 9 according to the present invention viewed from a side, and FIG. 9 b is an explanatory view showing the movement of the lens 2 of the device of example 9 according to the present invention viewed from upper direction; and
FIG. 10 is an explanatory view showing a device of example 10 according to the present invention viewed from a side direction.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Now referring to attached drawings, the examples as embodiments according to the present invention are explained in detail. FIGS. 1 to 10 show a construction of the respective example for one eye according to the wide field of view head mounted display device of the present invention.
EXAMPLE 1
FIGS 1 a and 1 b are explanatory views to show the device of example 1 according to the present invention in combination of a convex hyperboloidal mirror and a concave ellipsoidal mirror viewed respectively from a side and upper direction (or position). A beam of light from a LCD (liquid crystal display element) 1 as a display element is projected as an incident light on a convex hyperboloidal mirror 3 by a lens 2 of a dioptric system. The principal point of the lens 2 is located at a focus B of the hyperboloidal mirror 3 . When one of the focuses of the concave ellipsoidal mirror 4 is coincided with a focus A of the hyperboloidal mirror 3 , a light component reflected on a line connecting an intersecting point of the incident light with the hyperboloidal mirror 3 and the focus A of the hyperboloidal mirror 3 goes toward another focus C of the ellipsoidal mirror 4 upon reflection thereupon. That is, a virtual image is formed on the same axis with the reflected light at an opposite side to the reflected light from the ellipsoidal mirror 4 . Therefore, by allocating the focus C at a predetermined position of an observing pupil 5 , an image can be presented in a manner to observe a virtual image.
EXAMPLE 2
FIGS. 2 a and 2 b are explanatory views to show the device of example 2 according to the present invention in combination of a convex parabolic mirror and a concave ellipsoidal mirror viewed respectively from a side and upper direction. A beam of light from the LCD 1 as a display element is projected as an incident light on a convex parabolic mirror 6 by the lens 2 of a dioptric system. The lens 2 in this case constitutes a dioptric system such as a telecentric lens, for example, by which rays of incident light are projected as parallel rays. When one of the focuses of the concave ellipsoidal mirror 4 is coincided with a focus D of the parabolic mirror 6 , a light component reflected on a line connecting an intersecting point of the incident light with the parabolic mirror 6 and the focus D of the parabolic mirror 6 goes toward another focus C of the ellipsoidal mirror 4 upon reflection thereupon. That is, a virtual image is formed on the same axis with the reflected light at an opposite side to the reflected light from the ellipsoidal mirror 4 . Therefore, by allocating the focus C at a predetermined position of an observing pupil 5 , an image can be presented in a manner to observe a virtual image.
EXAMPLE 3
FIGS. 3 a and 3 b are explanatory views to show the device of example 3 according to the present invention in combination of a convex spherical mirror and a concave ellipsoidal mirror viewed respectively from a side and upper direction A beam of light from the LCD 1 as a display element is projected as an incident light on a convex spherical mirror 7 by the lens 2 of a dioptric system. When one of the focuses of the concave ellipsoidal mirror 4 is coincided with a center E of the spherical mirror 7 , a light component reflected on a line connecting an intersecting point of the incident light with the spherical mirror 7 and the center E of the spherical mirror 7 goes toward another focus C of the ellipsoidal mirror 4 upon reflection thereupon. That is, a virtual image is formed on the same axis with the reflected light at an opposite side to the reflected light from the ellipsoidal mirror 4 . Therefore, by allocating the focus C at a predetermined position of an observing pupil 5 , an image can be presented in a manner to observe a virtual image
EXAMPLE 4
FIGS. 4 a and 4 b are explanatory views to show the device of example 4 according to the present invention in combination of a convex hyperboloidal mirror and a concave spherical mirror viewed respectively from a side and upper direction. A beam of light from the LCD 1 as a display element is projected as an incident light on the convex hyperboloidal mirror 3 by the lens 2 of a dioptric system. The principal point of the lens 2 is placed at a focus B of the hyperboloidal mirror 3 . When the center of a concave spherical mirror 8 is coincided with a focus A of the hyperboloidal mirror 3 , a light component reflected on a line connecting an intersecting point of the incident light with the hyperboloidal mirror 3 and the focus A of the hyperboloidal mirror 3 goes toward the center of the spherical mirror 8 upon reflection thereupon. That is, a virtual image is formed on the same axis with the reflected light at an opposite side to the reflected light from the spherical mirror 8 . Therefore, by allocating the focus A at a predetermined position of an observing pupil 5 and making the hyperboloidal mirror 3 a half mirror, an image can be presented.
EXAMPLE 5
FIGS. 5 a and 5 b are explanatory views to show the device of example 5 according to the present invention in combination of a convex parabolic mirror and a concave spherical mirror viewed respectively from a side and upper direction. A beam of light from the LCD 1 as a display element is projected as an incident light on a convex parabolic mirror 6 by the lens 2 of a dioptric system. The lens 2 in this case constitutes a dioptric system such as a telecentric lens, for example, by which rays of incident light are projected as parallel rays. When the center of the concave spherical mirror 8 is coincided with a focus D of the parabolic mirror 6 , a light component reflected on a line connecting an intersecting point of the incident light with the parabolic mirror 6 and the focus D of the parabolic mirror 6 goes toward the center of the spherical mirror 8 upon reflection thereupon. That is, a virtual image is formed on the same axis with the reflected light at an opposite side to the reflected light from the spherical mirror 8 . Therefore, by allocating the focus C at a predetermined position of an observing pupil 5 and making the parabolic mirror 6 a half mirror, an image can be presented.
EXAMPLE 6
FIGS. 6 a and 6 b are explanatory views to show the device of example 6 according to the present invention in combination of a convex spherical mirror and concave spherical mirror viewed respectively from a side and upper direction A beam of light from the LCD 1 as a display element is projected as an incident light on the convex spherical mirror 7 by the lens 2 of a dioptric system. When the center of the concave spherical mirror 8 is coincided with the center F of the convex spherical mirror 7 , a light component reflected on a line connecting an intersecting point of the incident light with the convex spherical mirror 7 and the center F of the convex spherical mirror 7 goes toward the center F of the concave spherical mirror 8 upon reflection thereupon. That is, a virtual image is formed on the same axis with the reflected light at an opposite side to the reflected light from the concave spherical mirror 8 . Therefore, by allocating the center C of the concave spherical mirror 8 at a predetermined position of an observing pupil 5 and making the convex spherical mirror 7 a half mirror, an image can be presented
EXAMPLE 7
FIG. 7 a is an explanatory view to show a device of example 7 according to the present invention viewed from a side, by which a relative positional relationship of a display element, a dioptric system and a catoptic system can be changed. FIG. 7 b is an explanatory view of the movement of the lens 2 of the device of example 7 viewed from an upper direction. In addition to the constitution of the examples above (the constitution shown in FIG. 1 if shown), the device of this example is equipped with a lens moving mechanism 9 as a physical relationship changing means that is a piezo-actuator, for example, this mechanism 9 changing the position of the lens 2 of the dioptric system to the three dimensional direction along axes x, y, and z as shown, and a LCD moving mechanism 10 as a physical relationship changing mechanism that is a piezo-actuator, for example, this mechanism 10 changing the position of the LCD 1 as a display element to the three dimensional direction along axes x, y and z as in the similar case of the lens 2 .
In the device of this example 7, when the LCD moving mechanism 10 changes the position of the LCD 1 to the direction along x and/or y axis only for a distance less than one pitch of the pixels (half pitch, for example), by displacement of the pixels, the same effect as when number of pixels is increased can be obtained without movement of a position of the observing pupil 5 due to movement of the optical system, thereby resolution can be enhanced. Also the change of position of the LCD 1 along z axis causes the focused point to change, and the focused point can be coincided with the observing position of an observer, thereby a fine image can be presented. Also the change of the position of the lens 2 to the direction along x, y and/or z axis by the lens moving mechanism 9 displaces the projected position, and the displacement of pixels brings enhanced resolution similarly. When the lens 2 is moved, whether the lens 2 is displaced to up and down or left and right, the constitution of the optical system including the catoptric system is changed and a light projected from the LCD 1 reflects on a concave mirror preventing itself from passing through a focus of the concave mirror, whereby the position of the observing pupil 5 is displaced a little bit from the position of the focus of the concave mirror and thereby eclipse by the iris can be dissolved. Appropriate control of moving quantity of the lens 2 at the same time of the dissolution of the eclipse makes high resolution possible in accordance with the above. Depending on difference of the lens position, it is preferable to distort the image projected from the LCD 1 in conformity with the optical system.
EXAMPLE 8
FIG. 8 is an explanatory view of essential parts of the device of example 8 according to the present invention, by which a positional relationship of a display element and a dioptric system can be changed optically. In the device of this example, a transparent plate 11 comprising a conductive optical transparent material is disposed between the LCD 1 and lens 2 , as shown, in lieu of or in addition to the mechanical moving mechanisms 9 , 10 in the constitution of the example 7 above. Since refraction rate or orientation of this transparent plate 11 changes when a power is applied, the relative positional relationship of the LCD 1 and the lens 2 can be changed optically depending on number or thickness of the transparent plate 11 . Thereby resolution can be enhanced without changing the positional relationship between the lens 2 and the reflection mirror.
EXAMPLE 9
FIG. 9 a is an explanatory view of the device of the example 9 viewed from a side, enabling to pick-up an image of the pupil by a half mirror. FIG. 9 b is an explanatory view showing from the upper direction the movement of the lens 2 of the device of the example 9. This device of this example is equipped with a half mirror 12 disposed between the LCD 1 and the lens 2 , and lens 13 and an imaging element 14 positioned at the side of the half mirror 12 in addition to the constitution of the example above (the constitution shown in FIG. 7 if shown), the lens 13 magnifying an image of an observing pupil 5 , and the imaging element 14 picking-up the image of it, thereby observation of the center of the pupil is made possible. With this constitution, by controlling the position of the lens 2 to the convex mirror 3 by the lens moving mechanism 9 in order for the position of the pupil to be a center of the imaging element 14 , an image without eclipse can be presented.
EXAMPLE 10
FIG. 10 is also an explanatory view of the device of example 10 viewed from a side by which a pupil portion can be picked-up by a half mirror. The device of this example is equipped with the transparent plate 11 comprising a conductive optical transparent material disposed between the convex mirror 3 and the lens 2 in lieu of the lens moving mechanism 9 in the constitution of the example 9 shown in FIG. 9 . Since refraction rate or orientation of this conductive transparent plate 11 changes when a power is applied, the relative positional relationship among the reflection mirror and the couple of lens 2 and LCD 1 can be changed optically depending on number or thickness of the transparent plate 11 . With this constitution, by selecting the thickness of the conductive transparent plate 11 in order for the position of the pupil to be at a center of the imaging element 14 , an image without eclipse can be presented.
Any of the concave reflection mirrors (ellipsoidal mirror 4 and spherical mirror 8 ) in any of the examples has a size to bring 120 degree field of view horizontally per one eye and 180 or more degree by both eyes, and 60 degree field of view vertically per one eye. And any of the convex reflection mirrors (hyperboloidal mirror 3 , parabolic mirror 6 and spherical mirror 7 ) in any of the examples has a size capable of projecting the reflected lights to substantially all area of the concave reflection mirrors above.
The present invention has been described above based on the examples shown in the drawings. However, the present invention is not limited to the examples above and can be modified as needed within the scope of the claims.
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Provided is a wide field of view head mounted display device capable of presenting 120 degree field of view per one eye and 180 or more by both eyes horizontally while keeping resolution at least to the same extent of the conventional art. The wide field of view head mounted display device includes: a LCD 1 for displaying an image; a lens 2 for projecting an image displayed on the LCD 1 ; and a catoptric system with a concave mirror 4 and a convex mirror 3 . The LCD 1 and the lens 2 , the concave mirror 4 and convex mirror 3 are positioned in a relative relationship to observe by an observing pupil 5 at a predetermined position a virtual image of a beam of reflected light as an incident light on the concave mirror 4 when the light of displayed image on the LCD 1 is projected to the convex mirror 3 through the lens 2 and a reflected light of the projected light at the convex mirror 3 arrives as the incident light at the concave mirror 4.
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FIELD OF THE INVENTION
1. Background Of The Invention
This invention concerns an apparatus and method to remotely ignite very lean fuel air mixtures, with the aid of an ignition chamber, which is arranged in a main combustion chamber of an internal combustion engine. The ignition chamber is connected to the main combustion chamber through transfer channels, preferably arranged tangentially, whereby rich fuel air admixture or additional fuel is brought into the ignition chamber through valve gears. The invention further concerns a spark plug construction suited to the above discussed procedure, particularly for gas engines, which is equipped with transfer channels, preferably arranged tangentially, leading to the main combustion chamber; it is further equipped with a valve controlled supply channel which brings in rich fuel air admixture or additional fuel.
It is known that in order to ignite fuel air mixtures leaned, respectively weakened with either air and/or exhaust gas, in internal combustion engines to utilize ignition chamber or turbulence chambers known as pre-combustion chambers. Systems with homogeneous loads which have proven themselves with medium excess air ratios are shown, for instance, in the U.S. Pat. No. 1,127,512 or the West German Pat. No. 29 16 285. To achieve ignition, the mixture is pressed from the main combustion chamber into the chamber equipped with a spark plug during the compression stroke.
It is known from the literature, that in order to ignite a mixture which has been leaned considerably, additional fuel or a rich fuel air mixture must be brought into the chamber according to a so-called stratified charge concept (for instance VDI-Z, Vol 18, 1976, p. 885 ff or from the periodical Automobil-Industrie 4, 1976, p. 23 ff.). These two well known procedures require an extravagant injection of a very small quantity, respectively an additional carburating unit with complicated valve gear control. In order to eliminate this expense, it was suggested in West German application No. 24 50 980, to use valves which are controlled independently through the chamber pressure.
The high thermic load on the valve which is connected to the pre-combustion chamber and controlled with the chamber pressure is a big disadvantage for the procedure as it is known, that very high temperatures occur in the pre-combustion chamber.
Another disadvantage lies in the face that the mixing of the additional fuel, respectively admixture which is being added into the pre-combustion chamber is either insufficient or too slow, which creates uneven ignition and, therefore, uneven power transformation in the main combustion chamber.
SUMMARY AND OBJECTS OF THE INVENTION
It is an object of the invention to develop a method as mentioned above, and to develop a spark plug construction which would be suitable to achieve the inventive method through which an improved mixing of the additional fuel or the admixture in the ignition chamber can be achieved, whereby the temperatures which occur in the supply channel would be lower when compared to temperatures which results from known procedures.
According to the invention, a solution is provided through a method whereby the admixture or the additional fuel is brought to the main combustion chamber into the outlet area of at least one transfer channel or directly into at least one transfer channel. Further, the solution is made possible by a spark plug for which at least one outlet of the supply channel was arranged outside the ignition chamber in the area of at least one transfer channel.
Due to the discharge of the additional fuel or the admixture directly in front of at least one transfer channel of the ignition chamber, this additional fuel, respectively the admixture is pressed into the ignition chamber through the transfer channel or channels during the compression stroke whereby a good intermixing with the extremely lean mixture of the main combustion chamber, as well as a homogeneous ignition mixture is achieved due to the extended flow path to the point of ignition and the turbulence created due to the narrow channels through which it has to flow. An Optimum mixture is achieved with transfer channels opening tangentially into an ignition chamber which is utilized as a swirl chamber. Another advantage is achieved in that during the combustion stroke only the very lean mixture of the main combustion is pressed into the supply channel which has a much lower temperature when compared to the mixture of a precombustion chamber. The valves, connections, grid structures, exit valves, etc. which can be found therein, are, therefore, exposed to a much lower range of temperatures. Therefore, these design components can be designed more simply as well as more cheaply both as far as construction and material are concerned and have a markedly improved life span.
Through the measures listed in the sub-claims, favorable developments and improvements of the techniques listed in claim 1 and of the spark plug described in claim 4 are possible.
It is advantageous to have the supply channel located lateral to the ignition chamber and to have it open before an outlet of a transfer channel or at least in a transfer channel. From these places, the additional fuel or the admixture can be brought into the ignition chamber easily and without major losses.
An automatic ball valve is a particularly well suited valve to control the input of the additional fuel or the admixture. This ball valve is arranged in the combustion chamber outlet and/or the outside outlet of the supply channel and/or externally connected to the supply channel. Therefore, one or more valves can be utilized, either singly or in multiples switched one after the other to increase safety and input accuracy. If utilized in that manner, a valve arranged in or at the outlet of the supply channel suffers a minimum temperature load. It is also possible to utilize an electronically controlled solenoid valve at the outside outlet of the supply channel or in the supply line to this outlet, through which an even more exact dosage is possible.
An automatic valve in the supply channel arranged in series in front of the solenoid valve prevents an overload of the dosage through the hot mixture.
In order to add the additional fuel of the admixture directly into at least one transfer channel, it is suitably connected via a connecting channel to a valve utilized as a 3/2 way valve which is arranged at the combustion chamber side outlet of the supply channel, whereby the supply channel is connected to the connecting channel in a first valve position with a largely closed combustion chamber side valve outlet and, in a second valve position, the supply channel is closed. Thus, it is technically easy to mount the valve which can be regulated by means of its larger cross section directly above the main combustion chamber.
If several transfer channels are utilized directly to improve the mixture and the supply of the additional fuel or admixture, it is practical to form a ring chamber in the plug housing and connect it at one side to the supply channels. A suitable flow result is achieved by shaping the transfer channels like a Venturi nozzle, because this results in additional suction action.
A nozzle-like discharge outlet of the supply channels main combustion chamber side prevents the additional fuel or the admixture from penetrating as a jet too far into the interior of the main combustion chamber. The nozzle-like discharge forms a supply gas cloud in front of an opening of at least one transfer channel due to the very fine spraying action. In this manner, a sufficiently rich mixture can be achieved in the ignition chamber with a minimum amount of added additional fuel or admixture.
It has further proven to be advantageous to at least partially equip the supply channel with instruments to let off heat. This is preferred to be a grid type texture or a bar equipped with longitudinal grooves and/or longitudinal channels with good heat conductivity. The hot mixture which might have been introduced into the supply channel may be cooled in that manner through these instruments conducting off heat so that a valve or similar item placed behind it is not exposed to too high a temperature. In addition, these instruments also act as a flame trap device.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects obtained by its uses, reference is made to the accompanying drawings and descriptive matter in which preferred embodiments of the invention are illustrated.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a partial sectional view of a spark plug with a valve arranged on the outside according to a first embodiment of the invention;
FIG. 2 is a horizontal view through the spark plug shown in FIG. 1, along the lines of intersection I--I;
FIG. 3 is a partial cross sectional view of a spark plug construction with a valve arranged on an exit opening of the supply channel according to a second embodiment of the invention;
FIG. 4 is a partial cross sectional view of a spark plug construction with a valve arranged at the entrance opening of the supply channel according to a third embodiment of the invention;
FIG. 5 is a partial cross sectional view of a nozzle-like discharge outlet on the supply channel;
FIG. 6 is a horizontal cross-sectional view through the discharge outlet shown in FIG. 5;
FIG. 7 is a horizontal cross-sectional view of an alternative design of the discharge opening shown in FIG. 6;
FIG. 8, is a partial cross sectional view of a spark plug construction with a grid type texture in the supply channel;
FIG. 9 is a horizontal cross sectional view through a bar in the supply channel furnished with longitudinal grooves in order to let off heat;
FIG. 10 is a partial cross sectional view of a spark plug construction with an outlet of the supply channel in a transfer channel;
FIG. 11 is a horizontal cross sectional view through the spark plug construction shown in FIG. 10 taken along the line of intersection II--II in the direction of the arrows; and,
FIG. 12 is a partial cross sectional view of transfer channel in the shape of a Venturi nozzle of the embodiment of FIG. 10.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a first embodiment of a spark plug construction screwed into the wall 10 of a cylinder head as is commonly known. The spark plug construction includes a housing 12 furnished with an external thread 11, which is shown schematically in the lower area of FIG. 1. In the upper area of this housing 12 the construction is shaped as a hexagon 13, in order to guarantee screwing in and out with a wrench. The spark plug body includes an insulating body 14 which is built into this housing 12 which, in turn, surrounds a bar shaped connecting electrode 15, packing and insulating it. Electrode 15 reaches as far as the ignition chamber 16. This ignition chamber 16 is formed through an ignition chamber housing 17 which is set into the housing 12 through an appropriate opening.
The chamber housing 17 is firmly connected to housing 12, above all screwed in, welded in, pressed in, etc. and extends partially at the bottom of the housing 12 of the spark plug. In the ignition chamber 16, the connecting electrode 15 is furnished with an ignition electrode 18 oriented laterally whereby a spark gap is formed between it and a suitable arranged counter electrode 19 of the ignition chamber housing 17. Naturally, this spark gap forming electrodes can be in another, equally suitable shape.
As can be seen in connection with FIG. 2, the ignition chamber housing 17 in its lower area exhibits four transfer channels 21 which run diagonally downward to the main combustion chamber 20, exiting tangentially into the ignition chamber 16. In addition, it is equipped with an additional transfer channel 22 which progresses downward axially. In the upper area the ignition chamber housing 17 exhibits an enlarged step 23, whereby the spark gap is located in the extended area of the ignition chamber 16. This results in a particularly good flow pattern and a homogeneous mixture. However, more simply constructed ignition chambers could be used.
In order to simplify matters, the transfer channels 21 in FIG. 1 are shown in a way which is customary for a radial course. In spite of this, they do end tangentially in the ignition chamber 16 as shown in FIG. 2.
A supply channel 24 which is present in housing 12 of the spark plug ends on the combustion chamber side in the area directly before the opening of a transfer channel 21. It is equipped on the outside with a connection thread 25.
A valve body 26 is screwed into it, which on its opposite end, is equipped with a connecting nipple 27 for a connecting hose which is not shown. The valve body 26 can be equipped with either a valve which can be automatically pressure controlled or a solenoid valve. It is also possible to use an auto-regulated valve exclusively in the valve body 26, while a solenoid valve can be attached to its other end in the connecting hose at some further distance.
The mode of action of the design example shown in FIG. 1 consists of the fact that additional fuel or a rich fuel air admixture is added to the valve body 26 through its connecting nipple 27 under a particular pressure. In case of the preferred utilization in a gas engine, this consists of either a gas or a gas mixture. Of course, it can also be utilized for gasoline engines or diesel engines.
If only one auto-regulated valve is planned for valve body 26, a negative differential pressure is created between every two compression strokes through which the additional fuel or admixture can get to the main combustion chamber through the supply channel 24 while the valve is being opened. The amount necessary for this purpose is quite small, for instance less than 1% of the main fuel amount.
During the compression stroke which follows, the valve in valve body 26 closes and the additional fuel which comes into the main combustion chamber immediately in front of a transfer channel 21, is pressed via this transfer channel 21 into the ignition chamber 16. Due to its tangential entry, it results in turbulence and an excellent inter-mixing with the other, very lean fuel air mixture of the main combustion chamber is achieved. Since the path to the spark gap is quite long, a very homogeneous mixture with good ignition qualities is therefore present in the area of this spark gap, which, after successful ignition, gets to the main combustion chamber in an explosive fashion through the transfer channels 21, 22. It enters the main combustion chamber as highly heated gas jets or torch jets which there ignite the lean fuel air mixture.
Since the addition of additional fuel or admixture is necessary only immediately prior to a compression stroke, the input time interval can be optimized through a solenoid valve in or in front of the valve body 26. This can be closed through an ignition signal for instance, and can be kept in closed position based on a time interval dependent on the number of revolutions. A similar procedure is known from electronic gasoline injection. An alternative method might be to close the valve through an ignition signal for its assigned spark plug and to open it again through an ignition signal for the spark plug of another cylinder or through a crank shaft mark.
The second embodiment shown in FIG. 3, is shown with an auto regulated valve 28 on the chamber side outlet of supply channel 24. The spark plug, which is otherwise constructed in the same manner, is shown only partially. Corresponding construction units or areas are marked with identical numbers. The valve 28 is housed in the enlarged outlet of the supply channel 24, for instance pressed in or screwed in. A freely movable, spherically shaped valve element 30 is placed in a valve chamber 29. If the pressure in the main combustion chamber surpasses the pressure of the additional fuel, this valve element 30 is pressed against the upper valve seat 31, thus preventing invasion of the hot mixture from the main combustion chamber into the supply channel 24.
If pressure conditions are reversed, the valve element 30 is placed against the lower outlet 32 which is located opposite the valve seat 31, whereby additional fuel or admixture can pass by the valve element 30 through by-pass grooves 33. By-pass channels in the valve housing can be used instead of the by-pass grooves 33.
The third embodiment shown in FIG. 4 is equipped with an auto regulated valve 34 attached to the outside end of the supply channel 24 in the housing 12 of the spark plug. In its turn, this valve is equipped with a special valve element 38 arranged in a valve chamber 35 which is pressed against a valve seat 36 found on the outside end with the aid of a spring 37.
The pressure of the mixture present in the main combustion chamber pushes the valve element 38 in the direction of the spring power. If pressure in the main combustion chamber is low, the valve element 38 is lifted off the valve seat 36 against the pressure of the spring 37 due to the pressure of the additional fuel or admixture, which creates a passage through the valve 34.
Because of the more temperature sensitive spring 37, an arrangement of the valve 34 on the outside end of the supply channel 24 is planned. Basically, the mounting location of valves 28 and 34 can be exchanged freely, whereby valves such as these can also be placed in the valve body 26. Of course, just one such valve 28, respectively 34 is sufficient, however, it is possible to switch several valves in series, for instance as shown in FIGS. 3 and 4, valve 28 at the combustion chamber side opening and valve 34 at the outside opening of supply channel 24. In addition, in all cases, an additional solenoid valve can additionally be switched in series.
According to FIG. 5, the combustion chamber side outlet of the supply channel 24 can be equipped with nozzle-like discharge opening 39. In this instance, a disc, respective cylinder-shaped outlet part 40 is set into the enlarged outlet of the supply channel 24. It is either pressed or screwed in and, as shown in FIG. 6, it exhibits a number of axial channels 41, which are shaped as axial borings.
This prevents an exiting jet emerging from supply channel 24 which is too hard or which might reach too far. The additional fuel or admixture exists through this outlet opening in a fine spray, broadly distributed and distributes itself in front of the outlet of the assigned transfer channel 21.
As shown in FIG. 7, outside longitudinal grooves 43 can be used as channels for an outlet opening 42 in an alternate design. FIG. 8 shows an area of the supply channel 24 in a partial cross section into which a grid texture 44 with good heat conductivity was set. Instead of a grid texture, webbed structures or other structures with narrow through-passage openings may be used as well, for instance, a bar 45 with outside longitudinal grooves 46. A cross section of such a design as shown in FIG. 9
Such devices serve for better heat release of hot exhaust gases or mixtures which might have been pressed into the supply channel 24. On the one hand, they provide better protection of a valve located on the outside end of supply channel 24, and at the same time, provide excellent security against flame flash-back.
The embodiment shown in FIGS. 10 and 11 are again equipped with a valve 47 at the combustion chamber side opening of the supply channel 24. A freely movable spherical valve body 49 is mounted in its valve chamber 48. This valve element has an upper valve seat 50 which prevents invasion by gases into the supply channel 24 from the combustion chamber, and a lower valve seat 51 which prevents invasion by additional fuel or admixtures of the main combustion chamber. The lower valve seat 51 is equipped with an opening 52 to the main combustion chamber which means that the valve can be operated from the main combustion chamber pressure through this opening 52.
In its approximate center area, the valve chamber 48 is connected to a ring chamber 53 which partly passes through housing 12 and partly through the ignition chamber housing 17 and which extends over an angle of approximately 90°. Two connecting channels 54 pass from this ring chamber 53 to two transfer channels 21. They end in their approximate center areas. This enables the direct addition of additional fuel or admixture into the transfer channels 21 which, during the compression stroke, in then pressed through the lean mixture into the ignition chamber 16 and inter-mixed. In this manner additional fuel of admixture can be added directly into bypass channels 21. The valve control continues through the pressure in the main combustion chamber.
In a simplified design version in a change from the example shown, the valve chamber 48 can be connected with a transfer channel 21 through only one connecting channel 54. The ring chamber 53 can also extend over a larger angle area so that additional connection channels 54 for additional transfer channels 21 can be planned.
It has proven to be particularly advantageous to construct the transfer channels 21 in the manner of a Venturi nozzle as shown in FIG. 12. Here remaining additional fuel or admixture is sucked out of the connecting channel 54 connected to its most narrow part while a very lean mixture is flowing through the transfer channel. Another result is an even better mixing action.
Even if additional fuel or admixture is added directly into the main combustion chamber in front of the outlets or transfer channels 21, a similar design with a ring chamber in housing 12 can be planned, whereby one single supply channel 24 opens into this ring channel from the outside and, from this ring channel, several continuing supply channels open out in front of the outlets of the transfer channels 21 in the main combustion chamber.
While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.
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A method and a spark plug construction to ignite very lean fuel air mixtures with the aid of an ignition chamber with separate ignition, which is arranged in the main combustion chamber of an internal combustion engine, connected to the main combustion chamber 20 through transfer channels 21. Transfer channels may be provided which proceed tangentially, whereby rich fuel air admixtures or additional fuel is brought, valve timed, to the area of at least one transfer channel 21 outside the ignition chamber through a supply channel 24. During a compression stroke the very lean mixture in the main combustion chamber is pressed into the ignition chamber 16 through the transfer channels, which results in a very good intermixing with the additional fuel or the admixture due to the turbulent movement through the transfer channels 21 and the long path to the spark gap. This guarantees a very safe ignition.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to device processing and, in particular, to semiconductor processing.
2. Art Background
The selective etching of materials in processes such as semiconductor device processing is often required. For example, it is desirable in certain situations, such as in the production of appropriately configured gate oxides, to remove a region of silicon essentially without causing significant damage to an underlying or adjacent region of a silicon oxide, e.g., silicon dioxide. Processes such as plasma etching and reactive ion etching are often utilized to accomplish these results. In these techniques a gas is typically introduced in proximity to the body to be etched and a plasma is established in the gaseous medium producing molecular fragments, atoms, and ions. The resulting energetic entities produced by the plasma are directed towards the substrate and through various mechanisms remove the impacted material. By a particular choice of processing conditions and gases the rate of removal of a given material is, to an extent, controlled relative to the removal rate of other materials.
While in many situations etching involving energetic entities is advantageously employed, it is not without associated difficulties. The energetic particles produced in the plasma often affect even materials which are not etched at a substantial rate by, for example, inducing pitting or by unacceptably modifying surface electronic states. Pitting and electronic state modification for many device applications are not desirable since they often lead to defective device structures and thus device failure. Additionally, the use of a plasma also often leads to the deposition of contaminating materials onto the substrate surface. These contaminating materials, such as compounds produced from the plasma gas, and/or non-volatile metals from the reaction vessel, e.g., aluminum, either degrade device properties or hinder subsequent processing procedures.
Wet etching, i.e., use of a liquid based chemical that rapidly reacts with the material to be etched as compared to its rate of reaction with underlying or masked adjacent materials, is an alternative to plasma etching. Again, although wet chemical etching is advantageously employed in many procedures, it too is not without difficulties. For example, wet chemical etching leads to difficulties in handling and disposal of the associated chemicals. Additionally, if the temperature and concentration of the reagents are not carefully maintained, inconsistent results are obtained. Inconsistent results also arise from the wet etchant failing to reach micron features due to surface tension effects.
Although in many circumstances etching techniques, e.g., plasma etching and wet chemical etching, exhibit a degree of selectivity between the material being etched and adjoining material, this level of selectivity is generally not particularly high. For typical etching systems, selectivity, i.e., the rate of etching of the desired region relative to underlying or unmasked adjacent regions of different compositions, is not greater than 20 to 1. However, there are many applications, for example, the selective removal of silicon filaments from extremely thin silicon dioxide gates in high-speed field effect transistors, that require selectivity which is greater than 100 to 1.
Xenon difluoride in the absence of a plasma has been shown to produce selective etching between silicon dioxide and silicon. (See H. F. Winters et al, Applied Physics Letters, 34, 70 (1979).) However, rare gas halides are generally unstable and relatively costly. As a result, the use of rare gas halides is not a particularly satisfactory solution to the problems associated with other procedures. Therefore, common etching procedures have shortcomings and are not sufficiently selective for some important applications.
SUMMARY OF THE INVENTION
High selectivity, i.e., selectivity greater than 40 to 1, indeed greater than 100 to 1, is achieved in the etching of a variety materials as compared to underlying or unmasked adjacent regions of a second material by the use of polyatomic halogen fluorides either alone, as mixtures, or combined with inert gases, e.g., argon. For example, materials such as silicon, non-oxidic molybdenum compositions, non-oxidic tantalum compositions, e.g., tantalum, tantalum nitride, (materials represented by the formula Ta x N y where x>o and y≧o) and tantalum silicide, are readily etched as compared to a tantalum oxide, a silicon oxide, or a silicon nitride. The excellent selectivity of the invention is achieved in the absence of a plasma and without liquid etchants. In particular, materials such as BrF 5 , BrF 3 , ClF 3 , and IF 5 , have been found to produce this result. In contrast, diatomic halogen fluorides such as F 2 , ClF, and Cl 2 either (1) do not etch materials such as silicon or tantalum compositions, e.g., the silicide, nitride or elemental metal at all or (2) demonstrate extremely low etch rates. The selective etching achieved is quite useful in many device applications such as for the processing of gate oxides in field effect transistors, or for the production of tantalum nitride thin film resistors in conjunction with tantalum oxide thin film capacitors in hybrid, film integrated circuits. Additionally, the selectivity in the case of silicon is particularly advantageous for cleaning silicon deposits from the walls of chemical vapor deposition reactors.
DETAILED DESCRIPTION
Selective etching is accomplished by simply subjecting the body to be etched to a composition including a polyatomic halogen fluoride in gaseous form. (In this context, a polyatomic molecule is considered one with three or more atoms.) In general, non-oxidic compositions such as silicon, tantalum compositions, e.g., tantalum, tantalum nitrides, tantalum silicides, molybdenum, molybdenum compositions, e.g., molybdenum silicide, tungsten, and tungsten compositions such as tungsten silicide, are typically selectively etched by polyatomic halogen fluorides as compared to a second material if these compositions have a reaction rate of at least 1×10 14 molecules per cm 2 per sec as compared to a rate of at least 40 times smaller for that of the second material and provided that only volatile fluoride products, i.e., fluorides with vapor pressures at 26 degrees C. that are greater than 0.001 Torr, are formed. In contrast silicon nitride, the oxides of silicon, the oxides of tantalum, and the oxides of molybdenum and their mixtures that do not have these properties are essentially unetched. The number of fluorine atoms in the polyatomic halogen fluoride is not significant, provided they are present in conjunction with a non-fluorine, halogen atom. For example, polyatomic halogen fluorides such as BrF 5 , BrF 3 , ClF 3 , and IF 5 produce the desired degree of selectivity. (Although these compositions are commercially available, the source of these compounds is not critical and it is possible to generate them even in situ through reactions such as fluorination of bromine gas before etching. See N. V. Sidgwick, The Chemical Elements and Their Compounds, (London: Oxford University Press, 1952).)
The material to be etched is contacted with the appropriate gas simply by, in one embodiment, introducing this gas into a vessel containing the material. For example, it is possible to evacuate the chamber and then backfill it with any of the polyatomic halogen fluorides. (The use of the term polyatomic halogen fluoride includes not only polyatomic halogen fluoride gases but mixtures of polyatomic halogen fluoride gases.) Alternatively, it is possible to mix the polyatomic halogen fluoride with another gas, e.g., an inert gas, and introduce this mixture into the vessel. (An inert material is one which does not substantially react with the polyatomic halogen fluoride and which also does not react with the substrate in a way which retards the selectivity of the halogen fluoride.) Typically, with or without an inert gas, partial pressures of polyatomic halogen fluorides in the range 1 mTorr to 1 atm are employed. Generally, polyatomic halogen fluoride partial pressures less than 1 mTorr yield extremely low etch rates while partial pressures significantly higher than 1 atm lead to undesirably fast etch rates with the related difficulties in processing control, and thus are not preferred. High partial pressures also have a tendency to lead to the codensation of the product fluorides from the etching process.
Etching is continued until the desired thickness of material is removed. Typical etch rates of materials such as silicon and tantalum compositions for polyatomic halogen fluoride partial pressures in the range 0.1 to 10 Torr are respectively 50 to 5000 Å/min and 200 to 3000 Å/min. Therefore, quite nominal etching times are required for material thicknesses less than 100 μm. For most applications etching is limited to only a portion of a substrate through conventional lithography such as the use of patterned organic resists. However, as discussed, if, for example, a silicon region is to be etched, exposed regions of a silicon oxide need not be masked. After the etching is performed, the device is completed by conventional techniques such as described by S. Sze, VLSI Technology, (McGraw Hill, 1983) in the case of integrated circuits and by R. W. Berry et al, Thin Film Technology, (New York: R. E. Krieger Publishing Company, 1979) in the case of hybrid, film integrated circuits.
The cleaning of deposition equipment, e.g., CVD reactors is similarly performed by introducing the previously discussed concentrations of polyatomic halogen fluorides into the reactor. Etching is continued until the contamination, e.g., silicon, which is formed on the reactive walls--typically quartz or glass walls--is removed. Again for silicon deposits having thicknesses in the range 5 Å to 100 μm, nominal etching times are required.
The following examples are illustrative of the invention.
EXAMPLE 1
A hybrid, film integrated circuit on an alumina substrate was etched utilizing a polyatomic halogen fluoride. This circuit contained both thin film capacitors and resistors. The former were fabricated with anodically grown Ta 2 O 5 as the dielectric, a Ta composition containing 13 to 16 atomic percent nitrogen as the bottom electrode and Au as the counterelectrode. The resistors were defined by a photoresist pattern generated on a thin Ta 2 N film deposited after the capacitor anodization step.
The hybrid, film integrated circuit structure was placed on the sample holder of an aluminum chamber. The chamber was evacuated utilizing a mechanical roughing pump and booster stage to a pressure of approximately 5 mTorr. A flow of ClF 3 was then introduced into the chamber while vacuum pumping of the chamber was continued. The ClF 3 flow was adjusted to produce a pressure in the chamber of approximately 5 Torr. The ClF 3 flow was maintained for approximately 3 minutes and then terminated. Inspection of the hybrid, film integrated circuit with an optical microscope indicated that the tantalum nitride was completely removed in regions where it had been contacted by the gas while exposed regions of gold or tantalum oxide were essentially untouched. The regions of tantalum nitride underlying the photoresist were not affected by the ClF 3 nor was the photoresist significantly removed.
EXAMPLE 2
The procedure of Example 1 was followed except that BrF 3 was utilized as the etchant gas. The results were the same as those of Example 1.
EXAMPLE 3
The procedure of Example 1 was followed except the etching was done at a total pressure of 1 atm. This pressure was established by preparing a mixture of ClF 3 diluted to 5 percent in helium. The chamber was purged with a flow of argon and a sufficient flow of the helium/chlorine trifluoride mixture was introduced into the chamber and continued so that the measured pressure in the chamber remained at approximately 1 atm. Additionally, the sample was heated to a temperature of 86 degrees C. utilizing a resistively heated substrate holder. This heating was utilized to ensure that any products produced from the etching procedure were not deposited onto the hybrid, film integrated circuit.
EXAMPLE 4
An n-type silicon wafer measuring 3 inches in diameter and having its major surface in the (100) crystallographic plane was masked with a 1 μm thick pattern of silicon dioxide. This pattern was formed from squares of silicon dioxide 5 mm on a side covering the entire water surface and separated from each adjoining square by a 285 micron wide region of the silicon substrate. Samples typically measuring 3 mm on a side were cleaved from the masked wafer. The samples were cleaned by sequential rinses in methylene chloride, acetone, and methanol and then dipped in a 50 percent HF aqueous solution to remove any native oxide. Before use, the sample was rinsed in deionized water and blown dry in clean nitrogen.
The sample was placed on the sample holder of an aluminum chamber. The apparatus was evacuated to a pressure of approximately 5 mTorr and the sample was maintained at a temperature of approximately 23 degrees C. utilizing the resistively heated sample holder. A flow of BrF 3 was introduced into the chamber and was regulated to produce a pressure in the chamber of approximately 1 Torr. After approximately 5 minutes, the BrF 3 flow was terminated, the reactor was again evacuated, and the apparatus was then backfilled with 1 atm of helium.
The sample was removed from the etching apparatus and was immersed in a 50 percent aqueous HF solution for sufficient time to remove the silicon oxide masked material. The samples were then inspected utilizing an optical microscope. This inspection indicated that etch depths of approximately 25 microns were observed in exposed regions of the silicon wafer. This corresponded to an etch rate of approximately 5 microns per minute.
EXAMPLE 5
To measure the etch rate of silicon dioxide in BrF 3 , the same experiment as in Example 4 was performed except the treatment time was extended to 30 minutes. The thickness of the silicon oxide mask was measured before and after gas exposure utilizing a Nanospec optical thickness monitor. There was no detectable change in thickness of the oxide mask. (The smallest detectable thickness change for the measuring equipment was approximately 2 Å per minute per Torr.)
EXAMPLE 6
An n-type silicon wafer measuring 4 inches in diameter and having its major surface in the (100) crystallographic plane was entirely masked with a 1 μm thick layer of silicon dioxide. A 1 μm thick layer of TaSi 2 was then deposited over the silicon dioxide. Samples measuring 1 cm on a side were cleaved from the wafer. The samples were cleaned in sequential rinses in methylene chloride, acetone and methanol and blown dry with clean nitrogen. The samples were placed on the sample holder of an aluminum chamber. The apparatus was evacuated to a pressure of 5 mTorr and the samples were maintained at a temperature of approximately 80 degrees C. A flow of BrF 3 was established and regulated to produce a pressure of 5 Torr of BrF 3 in the chamber. After approximately 2 minutes, the BrF 3 flow was terminated, the reactor was again evacuated, and the apparatus was then backfilled with 1 atm of helium. All TaSi 2 was totally removed from the entire surface of the silicon dioxide layer.
EXAMPLE 7
The procedure of Example 6 was followed except Ta was deposited on the 1 μm thick silicon dioxide. The Ta layer was subjected to ClF 3 at a pressure of 1 Torr for a period of 2 minutes while maintaining the sample at 70 degrees C. This film was totally removed from the entire surface of the silicon dioxide layer.
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A highly selective--greater than 100 to 1--etch for silicon, tantalum, tantalum silicide and tantalum nitride is achieved by using polyatomic halogen fluorides. The selectivity is achievable without employing plasmas or wet etching.
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BACKGROUND AND FIELD OF INVENTION
In a large number of industrial processes one can observe the emission towards the atmosphere of gaseous flows containing organic solvents from painting, spraying, drying processes, furnaces and so on. The conditioning technologies available nowadays to solve this problem, since the regulations enforced by the various regional authorities state particularly low limits, may be summarized in two families:
Adsorption on Activated Carbon
It has the following drawbacks: it is impossible to find commercial activated carbons adapted to systematically adsorb different types of solvents present in the same flow;--possible desorption of a solvent already fixed in a flow which does not include it;--difficulty in regenerating said carbons with the resulting problem of their disposal as "toxic wastes";--in case said carbons get saturated with flammable solvents and problems for the/intrinsic safety of the plant itself.
Thermal After-Burning
The drawbacks experienced are the following:--it is necessary to raise the temperature of the flow by an outside fuel addition with particularly high associated operation costs;--possible formation of positively toxic chemical compounds within the flow, caused by high temperatures.
SUMMARY OF THE INVENTION
Taking the above into account, the Applicant has provided a new treatment suited to remove the above drawbacks, with the purpose of reaching the following benefits:--low operating costs measured in terms of the energy needed to destroy the solvents (by oxidation). The oxidation takes place at ambient temperature (approximately 20° C.);--approximately uniform effectiveness in the oxidation of both aromatic and aliphatic organic compounds;--no production of solid toxic wastes;--no generation of gaseous positively toxic compounds, or more toxic than the substances to be destroyed.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a schematic perspective view of the processing unit useful for the claimed treatment.
FIG. 2 is a chromatographic representation of the concentrations of waste gases present in a sample of effluent gas prior to the oxidation treatment of the present invention as described in the experimental Example below.
FIG. 3 is a chromatographic representation of the concentrations of waste gases present in a sample of effluent gas after the oxidation treatment of the present invention as described in the experimental Example below.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The gaseous matter carrying the organic solvents to be destroyed enters, at a temperature ranging from 180° C. to 40° C., the processing unit, shown schematically in the attached FIG. 1, which substantially comprises two stages:
First Stage, or Ionizing Stage
This portion substantially comprises metal plates 1 lying parallel to the flow and spaced apart from each other in such a way as to maximize the corona discharge generation. The plates are subjected to high voltages ranging from 15000 to 30000 V and from 500 to 1500 Hz in frequency, provided by a high voltage generator 3 in order to enhance the ionizing effect on the gaseous flow. The spacing between the plates is such as to get the highest possible electrical field intensity allowable for the gaseous flow subject to treatment. The plate length is related to the flow velocity, in that it determines the effective processing time. The electronic apparatus is provided with all the automatic controls and safety features necessary to make the plant operation safe and reliable.
Second Stage, or Catalytic Stage
The solvents carried by the gaseous substance undergo a first destructive treatment, while proceeding through the ionizing stage, for about 50% of the upstream contents. Free radicals are formed, in particular, which are able to develop their reactivity while contacting catalyst 2 comprised of oxides of metals such as Cr, V and metals of Group VIII, such as for instance Fe, Ni, and so on, whereby oxidation of the remaining portion takes place. The final result of this operation, if it were pushed to the extreme, would be the degradation of the solvents with production of carbon dioxide and steam. Since the cost of a plant increases exponentially versus the required efficiency, the system will be set up, with the objective of satisfying the limitations of the presently enforced law regulations, in such a way that there will still be traces of the solvent in the effluent. The results obtained by means of this equipment have been proved through laboratory research, where gas-chromatograms of the effluent were produced, in the original conditions and after processing through the system described herein. Example the laboratory tests were performed on a gaseous effluent containing xylene, toluene, butylacetate, butyl alcohol, methylisobutylketone (MIBK), methylethylketone (MEK), ethylacetate, and hexane. Tests were carried out at room temperature (about 20° C.), and the effluent processing time was approximately 1 sec (difference between inlet-outlet of the purifying unit) for a volume flowrate of 7 1/min. The gas-chromatograph used included a C20M column 6 meters long, with the following operating conditions:
starting isotherm: 12 minutes at 100° C.;
gradient: 5° C. min
final isotherm: 160° C.
The chromatograms shown in FIGS. 2 and 3 are relative to the effluent before and after the oxidation treatment of this invention.
Before the Treatment (see FIG. 2)
The concentrations are listed in the following Table.
______________________________________ CONCEN- PEAK NO. TIME AREA TRAT.______________________________________Hexane 1 5.113 16423 5.6459Ethylacetate 2 15.507 6735 2.3154Methylethylketone 3 16.948 9418 3.2378Methylisobutylketone 4 22.738 41716 14.341Butyl Alcohol 5 24.808 67515 23.2101Butylacetate 6 25.513 34325 11.8001Toluene 7 28.72 41240 14.1773Xylenes 8 30.46 73514 25.2724After the Treatment(see FIG. 3).Hexane 1 5.092 15041 34.6862Ethylacetate 2 15.232 2977 6.8658Methylethylketone 3 16.682 2718 6.2675Methylisobutylketone 4 22.522 1463 3.3732Butyl Alcohol 5 24.607 7200 16.6042Butylacetate 6 25.317 4270 9.8472Toluene 7 28.548 5232 12.0663Xylenes 8 30.292 3614 8.3343______________________________________
As it can be seen when comparing the height of the peaks and the extent of the related areas before and after the treatment, the quantities of organic components still present at the outlet are drastically reduced compared to the starting ones. For the tests that were performed the following reductions were obtained:
Xylenes:--95%; Toluene:--83%; Butylacetate:--87%; Butyl Alcohol:--89%; MIBK:--96%; MEK:--70%; Ethylacetate:--55%.
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A vapour and gaseous effluent purification process wherein the gaseous flow is made to proceed between metal plates (1) subjected to oscillating electrical high voltages and then over a porous siliceous mass (2) having adsorbed therein an oxidation catalyst active at room temperature.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method and apparatus for applying screw threads to a screw blank, the threads having a unique orientation. More specifically, the invention is directed to a device and method of cutting threads into a screw wherein the threads increase in cutting angle from the point to the top of the screw body. Furthermore, the screw core increases in diameter over the same length.
2. Description of the Prior Art
Screws have been utilized for a considerable period of time for the fastening of various objects to each other. Screws are particularly utilized for creating a joinder between two materials through the use of cutting threads which securely mount the shaft of the screw into a mounting substrate. Traditional screw threads cut a helical path through the substrate in an even and parallel form in order to maximize the binding characteristic of the screw while creating as little damage as possible to the substrate when the screw is inserted. While most screws are regular in the orientation of their threads and the sizing thereof, several screws have been developed which enjoy unique and irregular screw thread and core patterns.
A number of screws have been proposed which utilize a tapered central core in which the core of the screw and possibly the threads attached thereto has a smaller overall diameter at the point of the screw than at the head of the screw. This cone-shaped object is utilized for piercing and self-threading applications in which the screw is driven directly into a substrate without the need for a pilot hole or other starting techniques.
One shortcoming of screws having equally spaced and parallel threads is that the screw develops no compressive force on the substrate. While this is generally beneficial when utilized with a fragile substrate or an application in which the members to be joined are correctly oriented prior to insertion of the screw, in some applications it would be advantageous to develop a compressive force on the substrate exerted by the screw. This has been achieved in Lasner, a co-pending application, entitled "BONE SCREW WITH IMPROVED THREADS", bearing Ser. No. 07/618,500, filed Nov. 27, 1990, now U.S. Pat. No. 5,120,171. In this reference, a screw having threads which are progressively canted over the length of the screw is disclosed. The screw utilizes a tapered central core which is narrower at the point end and wider at the head end. The screw threads are angled at the point end in a fashion roughly perpendicular to the longitudinal axis of the screw core. As the threads progress along the screw core from the point end to the head end, the angle of the threads gradually increases from the nearly perpendicular with respect to the core surface to form a series of increasing obtuse angles with respect thereto. This screw develops a compressive force on the substrate material as it is inserted as the increasing cant of the threads over the length of the screw develops an increasing force on the substrate as they enter into it. An increasing continuum of compressive force is therefore developed along the longitudinal axis of the screw with the least amount of compressive force being present at the point end and the most compressive force being present at the head end. The reference does not, however, describe a method or apparatus for creating such threads on a traditional screw blank.
Screws may generally be manufactured in one of two ways. The first is to create a mold and cast a screw in the shape of the mold. The second is to begin with a screw blank and cut the threads into the blank utilizing a lathe or similar device. Even with the cast embodiment, an original prototype must be utilized to create the mold and no method or apparatus has been previously described which is capable of creating progressively canted threads along a screw body. Furthermore, while cutting devices have been proposed which permit the cutting of a tapered screw core with or without tapered threads thereon, no method or apparatus has been proposed which achieves the manufacturer of a screw having a tapered core and threads of varying cant.
What is lacking in the art, therefore, is a cutting device which is capable of variably cutting screw threads into a screw blank and which may further apply such threads to a screw blank having a tapered core.
SUMMARY OF THE INVENTION
A cutting device and method for its operation are disclosed in which a two step process is utilized to apply variably canted threads to a screw blank. A conventional cutting lathe is modified according to the specification herein in order to achieve the desired result. The lathe is provided with a conventional hydraulically operated adjustable cutting support attached thereto. A typical lathe suitable for this operation is the Doall 13, model number 112M 590. The hydraulic cutting armature is also commercially available as the True Trace 2055A.
The adjustable cutting armature is traditionally utilized to cut variably surfaced shapes into a cylindrical workpiece while it is being rotated on the lathe. The armature is generally adjustable with respect to the workpiece in terms of both distance and angle of cutting attack. A guide plate is generally mounted upon the lathe adjacent the armature, which is guided therealong to produce a particular pattern. The pattern is provided to scale on the guide plate and the armature is abutted to the guide plate during operation. As the armature moves along the guide plate the pattern thereof is inscribed, to scale, into the workpiece.
The armature is pivotable to permit cutting at particular angles into the surface of a workpiece but is generally not pivoted during the cutting operation. A secondary guide has been developed and is utilized in producing a controlled variable pivot of a cutting head pivotably mounted on the cutting armature during its progression along the body of the workpiece. The secondary guide is rigidly mounted to the cutting head and precisely controls its movement during the cutting operation. This produces a cutting operation having dual movement characteristics. The cutting armature and cutting head are moved longitudinally along the axis of the workpiece and the cutting head is simultaneously rotated about its pivot point to create a change in cutting angle over the length of this screw blank body. It is this particular dual movement capability that permits the production of the variably canted threads.
In order to produce the variably canted threads on a screw body having a tapered core, a preliminary cutting operation is first performed on the screw blank according to the traditional operation of the adjustable cutting support in which the cutting depth of the armature is changed over the course of the cutting operation. While well known in the prior art, this preliminary cutting step permits the combination of the tapered core of the screw body and the variably canted threads.
These and other advantages and features of the present invention will be more fully understood with reference to the presently preferred embodiments thereof and to the appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric view of the assembled apparatus having a workpiece in place.
FIG. 2 is a top plan view of a portion of the apparatus showing a preliminary cutting operation.
FIG. 3 is a top plan view of a portion of the apparatus displaying the secondary guide mechanism and the rotation of the adjustable cutting armature.
FIG. 4 is a top plan view of a portion of the apparatus illustrating the rotation of the adjustable cutting apparatus when compared with FIG. 3.
FIG. 5 is an isometric view of the cutting head of the apparatus.
FIG. 6 is a top plan view of the workpiece undergoing the cutting operation producing the variably canted threads.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 1, a lathe 5 is provided with a number of customized modifications. The lathe itself, however, is a standard model utilized for the turning of small objects. The lathe generally includes a number of electronic controls for setting the speed of cutting, time of rotation and other operating parameters which are not illustrated in the Figure nor will be described here. It is assumed that these features are generally well known to those skilled in the art and the description of their operation is unnecessary. In operation, the utilization of the lathe itself is through the utilization of common turning techniques and the operation of the machine is essentially unchanged. The lathe is generally provided with a movable carriage 10 supported upon a support rod 15 and a drive rod 20. The carriage 10 is adapted to be displaced longitudinally along support rod 15 which is generally cylindrical in cross-section to permit the sliding of the carriage therealong. The drive rod 20 is a threaded rod which threadably engages the carriage 10 and is utilized to displace the carriage 10 longitudinally with respect to the work piece. The drive rod 20 is motorized in a conventional manner and is controllably turned through the operation of the lathe 5. As the threaded drive rod 20 rotates, the carriage 10 is controllably displaced through the operation of the threads.
Mounted upon the carriage 10 is an adjustable cutting armature which is also a commercially available item. The adjustable cutting armature 35 is hydraulically operated and is fed through hydraulic lines 46 from a pumping mechanism which is not displayed in the Figure.
The adjustable cutting armature 35 is utilized according to its intended purpose with the only modification thereto being the adaptation of a specialized cutting head which is mounted in an appropriate place on its top surface. In general, the operation of the adjustable cutting armature 35 is such that it is slidably mounted upon the carriage 10. The armature has an elongated portion upon which a traveler wheel 45 is mounted. The traveler wheel 45 engages an adjustable cutting guide 40 mounted upon the lathe. In operation, the adjustable cutting armature is position upon the carriage 10 with the cutting head 50 mounted thereon. The adjustable cutting guide 40 is mounted upon the lathe and the traveler wheel 45 is positioned adjacent thereto. As the carriage 10 travels along support rod 15 through the operation of drive rod 20, the traveler wheel 45 is moved along the edge surface of adjustable cutting guide 40. Adjustable cutting guide 40 has a pattern engraved along the edge thereof, which is to be replicated by the cutting head 50 on the workpiece. As the traveler wheel 45 moves along the pattern edge of adjustable cutting guide 40, the adjustable cutting armature is slidably displaced on carriage 10 and consequently adjusts the position of cutting head 50 relative to the workpiece, or screw 55 in this particular case. Adjustable cutting guide 40 is sized proportionally to correctly position the cutting head 50 on the smaller workpiece. In this way, an overall cutting pattern may be engraved upon the workpiece. In this particular embodiment, the adjustable cutting armature 35 is utilized to achieve the tapered central core on the screw workpiece as will be described more fully with reference to this specific cutting operation and FIG. 2.
The lathe 5 is provided with a left chuck 25 and a right chuck 30, as shown in FIG. 1, in order to support and rotate the workpiece, or screw 55 as shown in FIG. 1. The lathe and chuck mechanism operate in a conventional fashion with the chuck spinning at a desired velocity. The force to the chucks is provided through a conventional motoring gear system which is well known to those skilled in the art, and is included in the preassembled lathe device. The screw 55 is firmly clamped along the longitudinal axis of the chuck, such that it is rotated with a minimum amount of eccentricity.
Referring now to FIG. 2, a portion of the device is illustrated which is particularly directed to the orientation of the cutting head and the workpiece during a preliminary cutting operation. This preliminary cutting operation is generally according to the teachings of the prior art for production of a tapered screw core. As previously illustrated with reference to FIG. 1, the carriage 10 is mounted upon support rod 15 and drive rod 20 which is threaded t longitudinally displace carriage 10 with respect to the workpiece or screw 55 as particularly illustrated in FIG. 2. Carriage 10 has adjustable cutting armature 35 slidably mounted thereupon, although the sliding element is not displayed. Hydraulic lines 46 provide hydraulic power to the adjustable cutting armature 35 to control its relative motion. Cutting head 50 is rotatably affixed to adjustable cutting armature 35 and is positioned such that it abuts the screw 55 during the cutting operation. For the purposes of this preliminary operation, the cutting head 50 is rigidly fixed with respect to the adjustable cutting armature 35.
The screw 55 is mounted within the chucks 25 and 30 and is provided with head and tip bosses 56 and 57, respectively, for mounting within the chucks. The tip boss is later removed to create a pointed end while the head boss 56 becomes either a portion of the screw shaft or is removed to create the head of the screw. As illustrated in FIG. 2, the threads 65 of screw 55 have already been cut according to a preliminary cutting step which is optionally utilized to create a tapered screw core 60 having threads of varying thickness and a core of varying diameter. As can be seen in FIG. 2, the diameter of the screw core 60 is considerably smaller at the end adjacent tip boss 57 as that adjacent head boss 56. Consequently, the depth of the threads is larger at the tip end of the screw 55 but the threads themselves are thicker at the head end of the screw. Thread thickness 80 is therefore dependent upon the location of the thread along the longitudinal axis of the screw 55 and decreases in a uniform and linear relationship from end to end.
Each of the threads has a leading thread face 70 and a trailing thread face 75. For the purposes of this discussion, the leading thread face 70 shall be designated that facing the tip end of the screw 55 and the trailing thread face 75 shall be that facing the head end of the screw 55. As can be seen in FIG. 2, the leading thread faces of each thread are all parallel to each other as are the trailing thread faces while the distance between them for each thread revolution increases from tip to head.
This cutting operation is achieved through the use of the adjustable cutting armature 35 and adjustable cutting guide 40. With further references to both FIGS. 1 and 2, a triangular adjustable cutting guide 40 is utilized to produce this particular thread effect. The cutting operation is begun at the tip end of the screw blank and the traveler wheel 45 of the adjustable cutting armature 35 is at the lowest point of the triangularly shaped adjustable cutting guide 40. As the cutting operation commences and the carriage 10 and adjustable cutting armature 35 are displaced leftwardly, that is, from tip to head end of the screw 55 along support rod 15, the adjustable cutting armature 35 is withdrawn in a linear continuous fashion, perpendicular to its longitudinal displacement, to create a shallower cut in the screw 55 as the cutting operation proceeds. This is caused by the triangularly shaped adjustable cutting guide 40 upon which the traveler wheel 45 rests. As the traveler wheel 45 moves along the patterned edge of the adjustable cutting guide 40, it is forced outwardly by the triangular shape thereof. This force is translated to the cutting head 50 which mimics the triangular pattern of the adjustable cutting guide 40 in its cut into screw 55. The effect of this movement is illustrated in FIG. 2 in the tapered central core 60 of screw 55 and the widening thread thickness 80 as one proceeds from the tip end to the head end of the screw 55. It is to be specifically noted that this particular tapering preliminary step is optional and is utilized to produce the tapered cone embodiment of the screw. If a non-tapered screw were desired having the variably canted threads described previously, the preliminary step would be utilized with a straight adjustable cutting guide 40 rather than the triangular embodiment described previously.
FIG. 3 illustrates the secondary guide 82 which produces the second movement characteristic of adjustable cutting armature 35 to produce the variably canted threads. As illustrated in FIG. 3, carriage 10 is again mounted with adjustable cutting armature 35 thereon. Adjustable cutting armature 35 is fixed for this operation on carriage 10. Secondary guide 82 is utilized, however, to create a secondary rotational pivoting motion of cutting head 50 simultaneous to the longitudinal displacement of the carriage 10 and cutting head 50 during the cutting operation with respect to the workpiece. This is achieved through the combination of several elements which provide a controlled pivoting motion. The lathe 5 is provided with a planar bulkhead area adjacent to the mounting of the workpiece and the traveling area of carriage 10. Upon this planar area, a pivot stop 95 and a pivot fulcrum 90 are permanently mounted. Inserted between the pivot stop 95 and pivot fulcrum 90 is a pivot bar 85 which is abutting both pivot stop 95 and pivot fulcrum 90. Pivot bar 85 is otherwise freely movable and is not affixed in any way to pivot stop 95, pivot fulcrum 90 or lathe 5. Pivot bar 85 is affixed to cutting head 50 through a connecting rod 105 which is rigid and permanently mounted to both pivot bar 85 and cutting head 50. A rotation surface 100 is provided at one end of pivot stop 95 to control the movement of pivot bar 85 during the cutting operation. Changes in the curvature of rotation surface 100 are utilized to adjust the beginning cutting angle, end cutting angle and rate of change between those parameters.
The operation of the secondary guide 82 is further illustrated with reference to both FIGS. 3 and 4. As shown in FIG. 3, carriage 10, during the cutting operation, is moved leftwardly according to the triple arrow in order to achieve a two step cutting operation of the screw 55 (not shown). In a conventional cutting operation, as with the preliminary operation described with reference to FIG. 2, the cutting head 50 would be oriented perpendicularly to the longitudinal axis of the screw in order to achieve a regular parallel threaded surface. The purpose of secondary guide 82 is to pivotably rotate cutting head 50 with relation to adjustable cutting armature 35 during the longitudinal displacement of carriage 10 according to the triple arrow. This rotational movement is indicated by the single arrows in FIG. 3. As carriage 10 and cutting head 50 are displaced leftwardly according to the triple arrow, pivot rod 85 is urged against pivot stop 95 because of the rigid connection of connecting rod 105 between cutting head 50 and pivot bar 85. Pivot bar 85 is further restrained by pivot fulcrum 90 such that as it is urged against pivot stop 95, it is forced into a circular rotational motion as illustrated by the double arrow of FIG. 3. As carriage 10 and cutting head 50 move leftwardly according to the triple arrow, pivot bar 85 is rotated rightwardly in a circular manner according to the double arrow. Pivot bar 85 is rotated along rotation surface 100 because of the presence of pivot fulcrum 90, as shown in FIGS. 3 and 4. As shown in FIG. 4, the double arrow indicates the rotation of pivot bar 85 away from pivot stop 95 and around the curved rotational surface 100. The curvature characteristics of rotation surface 100 are therefore utilized to determine the rate of change of rotation of adjustable cutting armature 35 and head 50. A more gently rounded rotation surface 100 will cause a more gradual rotation of adjustable cutting armature 35, while a sharp drop off in rotation surface 100 will cause a rapid rotation of cutting armature 35. This rotation is further illustrated in FIG. 4 which indicates the rotation of cutting head 50 on adjustable cutting armature 35 through single arrows and the change in position thereof with respect to FIG. 3 through the use of a chain line. It should be specifically noted that at all times pivot bar 85 is restrained from movement away from its abutting position with respect to pivot stop 95 by pivot fulcrum 90. In this way, a controlled rotational motion of cutting head 50 is achieved which is directly attributable to and proportional with the movement of carriage 10 in along the longitudinal axis of the screw. The effect of this dual characteristic motion will be further explained with reference to FIG. 6.
Refering now to FIG. 5, cutting head 50 is shown as pivotably mounted to adjustable cutting armature 35. A connecting rod mounting hole 155 is provided to engage and restrain connecting rod 105, as illustrated in FIGS. 3 and 4. Cutting head 50 is comprised of a rotational cutting head base 110, cutting head adapter 120, slidably mounted on said rotational cutting head base 110 and adjustable in a first dimension with in cutting base slot 115, cutting insert support 135, where is slidably mounted on said cutting head adapter 120 and adjustable in a second dimension within cutting head adapter slot 130, cutting insert 132, and cutting insert support locking means 145 for firmly affixing the cutting insert 132 to the cutting insert support 135. Cutting head base slot 115 and cutting head adapter slot 130 are generally perpendicular to each other, permitting relative movement of cutting the cutting insert 132 in two dimensions.
Referring now to FIG. 6, the screw 55 is illustrated following the second cut, producing the variably canted threads 65. The screw 55 is again mounted within the chucks 25 and 30 by the respective bosses 56 and 57. The screw 55 has first been cut according to the previous description with reference to FIG. 2. If the device has been adapted according to the previous description, the screw 55 need not be removed from the chucks between cutting operations. The cutting head 50 is released from its fixed position, and the adjustable cutting armature 35 is fixed if the non-tapered embodiment is to be produced. If a tapered screw core 60 is to be produced, then the triangular adjustable cutting guide 40 is again utilized so that the adjustable cutting armature will follow the same cutting pattern during the second cut as the first.
The cutting insert 132 is placed adjacent the leading face 70 of the first thread nearest the tip boss 57. The carriage 10 is moved longitudinally from the tip end of the screw to the head end. As previously described, the cutting insert 132, mounted in cutting head 50, is rotated as well as displaced longitudinally by the secondary guide 82. This causes the cutting insert to change its orientation with relation to the longitudinal axis of the screw 55 during the cutting operation. At point A, as shown in FIG. 6, the cutting insert 132, which has been exaggerated in the Figure for clarity, is positioned nearly identically to its starting, or first position. As the carriage 10 and cutting insert 132 move longitudinally along the length of the screw 55, the cutting insert is rotated through positions B and C, as illustrated in FIG. 6. This change of cutting angle of cutting insert 132 causes a change in the shape of the groove cut into the screw 55. The cant of each successive thread 65 with forms the walls of the groove is therefore continuously varied along the longitudinal axis of the screw 55. The rate of change of the angle of the cutting insert 132's attack on the screw 55 is adjusted through the curvature characteristics of rotation surface 100, as described with reference to FIGS. 3 and 4.
While a present preferred embodiment of the invention is described, it is to be distinctly understood that the invention is not limited thereto but may be otherwise embodied and practiced within the scope of the following claims.
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A cutting device and method for its operation are utilized to apply variably canted threads to a screw blank. A conventional cutting lathe is provided with a conventional hydraulically operated adjustable cutting support attached thereto. A guide plate is generally mounted upon the lathe adjacent the armature, which is guided therealong to produce a particular pattern in the workpiece. The armature is pivotable to permit cutting at particular angles into the surface of a workpiece. A secondary guide is utilized in producing a controlled variable pivot of the cutting armature during its progression along the body of the workpiece. The secondary guide is rigidly mounted to the adjustable cutting armature and precisely controls its movement during the cutting operation, producing a cutting operation having dual movement characteristics. The cutting armature is moved longitudinally along the axis of the workpiece which simultaneously rotating about its pivot point to create a change in cutting angle over the length of this screw blank body. In order to produce the variably canted threads on a screw body having a tapered core, a preliminary cutting operation is first performed on the screw blank according to the traditional operation of the adjustable cutting support in which the cutting depth of the armature is changed over the course of the cutting operation. This preliminary cutting step permits the combination of the tapered core of the screw body and the variably canted threads.
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RELATED APPLICATIONS
This application claims priority to provisional application Ser. No. 60/347,973 filed Nov. 13, 2001 and incorporated herein by reference.
BACKGROUND OF THE INVENTION
A. Field of Invention
This application pertains to a device for tensioning the cord used for operating a roller blind or other similar window covering, and more particularly to a tensioning device that is adapted to adjust the tension automatically to adjust for changes in the physical characteristics of the cord.
B. Description of the Prior Art
Window coverings such as roller blinds, vertical and horizontal Venetian blinds, and so on, are typically operated by control cords that can be pulled in one direction or another. While many window coverings use a cord with two ends, systems are also popular that use a cord forming a closed loop. However, such systems are alleged ti be potentially dangerous to children. Therefore, interested organizations (such as the American National Standards Institute (ANSI) and the Window Covering Manufacturers Association (WCMA)) have developed a specification, in conjunction with the Consumer Products Safety Commission (CPSC), requiring such closed loop cord control systems to be secured by a tensioning device. The tensioning device is used externally of the window covering and is arranged so that it applies a tension in the cord within a predetermined range.
These tensioning devices are extremely effective in minimizing the danger to infants and young children resulting from the improper use of these cords. However, one problem with them is that during installation they must be carefully adjusted because if too much tension is applied, the window covering becomes difficult to operate and the additional stress on the window covering components results in a high wear and tear and reduced useful life. In fact, under certain conditions if the tension is high enough, the window covering may stop operating.
Strict instructions are normally provided to installers on how to install the window covering and the tensioning device. However, these instructions are frequently ignored, especially if the installer is the homeowner and not a professional.
A further problem in existing tensioning devices is that a high tension may develop after the tensioning device is installed due to changes in the physical characteristics of cord. For example, if the cord is made of knit or braided material, its fibers may shrink due to age, temperature and/or humidity changes, resulting in an increased tension.
OBJECTIVES AND SUMMARY OF THE INVENTION
In view of the disadvantages of the prior art, it is an objective of the present invention to provide a tensioning device that adjusts automatically to maintain tension in a continuous cord to a predetermined level.
A further objective is to provide a tensioning device that can be installed easily and quickly without requiring any special tools or techniques.
Yet another objective is to provide a tensioning device that does not require any extensive redesign, changes of components or other increased costs.
Other objectives and advantages of the invention shall become apparent from the following description.
Briefly, a tensioning device adapted to tension a cord loop of a window treatment apparatus includes a housing; a cord guide disposed in said housing and adapted to receive a portion of the cord loop; a biasing member adapted to bias said cord guide to apply tension on said cord loop; and locking means adapted to lock said cord guide in an installation position, said locking means being removable to allow said cord guide to tension said cord loop. The locking means includes a tab removably inserted into said cord guide. The tab may be a flexible tab extending through said housing and said cord guide. In one embodiment, rails defining a path of movement for said cord guide are disposed within said housing, the cord guide being adapted to shift up and down in the housing along the guide to selectively increase or decrease the tension on the cord loop.
In another embodiment, the cord guide includes a pulley rotatably disposed in said housing.
In another aspect of the invention, the tensioning device includes a housing having two housing portions; a cord guide movably disposed within said housing and adapted to receive a cord loop; a biasing spring coupled to said cord guide and adapted to apply a biasing force on said cord guide to thereby tension said cord loop; and a locking tab extending through said housing, said locking tab being constructed and arranged to lock said cord guide against movement during installation, said locking tab being removable to release said biasing spring.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a perspective view of a window covering with a first prior art tensioning device;
FIGS. 2 a and 2 b show perspective views of other prior art tensioning devices without springs;
FIGS. 3A-3C show a side elevational view of a prior art tensioning device with a spring and a pulley in an unmounted position, a mounted and operational position and a mounted and inoperational position, respectively;
FIG. 4 shows an exploded view of a tensioning device constructed in accordance with this invention;
FIG. 5 shows a side elevational cross sectional view of a tensioning device constructed in accordance with this invention;
FIG. 6 shows a front perspective elevational view of a tensioning device constructed in accordance with this invention with the housing closed;
FIG. 7 shows a rear perspective elevational view of a tensioning device constructed in accordance with this invention, with the housing closed.
FIGS. 8A-8C show a side elevational view of a tensioning device without a pulley constructed in accordance with the present invention in a mounted, a mounted intermediate, and a mounted final position, respectively;
FIG. 9 shows a perspective view of an alternate embodiment of the invention with a pulley;
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a typical installation of a window treatment apparatus with tensioning means. The window treatment apparatus 10 consists in this case of a folded panel 12 hanging from a cassette 14 . The cassette 14 is secured to a window frame 16 . Incorporated within the cassette 14 there is a mechanism (not shown) which is not part of this invention and which is activated or operated by a cord loop 18 . The cord loop passes through a tension device 20 also secured to the window frame 16 and is adapted to provide tension in cord loop 18 . FIGS. 2A and 2B show two types of tension devices 20 A and 20 B which do not utilize springs or any other active means of generating tension in the loop cord 18 . Hence, the tension in the loop cord 18 is controlled only by the position of the tension devices on the frame 16 . If this position is not selected properly, or if the loop cord 18 shrinks over time, the tension within the loop will increase, possibly to a level that may render the apparatus 10 inoperable.
FIGS. 3A-3C show a more advanced tensioning device 20 C for tensioning cord loop 18 . The device 20 C includes a housing 22 supported by a bracket 24 . Inside the housing there is provided a pulley 26 biased in the downward direction by a spring 28 . The cord loop 18 is trained around the pulley, as shown. FIG. 3A shows the tension device 20 C before installation, with the spring 28 being relaxed. FIG. 3B shows the device 20 C installed. Normally, the device 20 C is positioned so that the pulley 26 is raised slightly and pushes upwardly against the spring 28 . In this position, the tension in cord loop 18 is dependent on the force generated by the spring 28 . However, if the device 20 C is installed too low and/or if the cord loop 18 shrinks excessively, the pulley 26 is raised sufficiently to squeeze the spring 28 tightly up against the top 30 of housing 22 . Under these conditions, the spring 28 is in effect disabled and the tension within the cord loop 18 may be high enough to interfere with the operation of, or even disable the respective apparatus. A tensioning device of this type is disclosed in U.S. Pat. No. 6,311,756, incorporated herein by reference.
A tensioning apparatus constructed in accordance with the present invention is shown in FIGS. 4-8. In this embodiment, the apparatus 120 includes a housing 122 formed of two housing parts 122 A, 122 B. A through hole 123 passes through the housing parts 122 A, 122 B. A bracket 24 is constructed and arranged to be mounted on a window frame. A straight pin 25 is used to attach housing 122 to the bracket 24 by passing the pin 25 through holes 123 and 125 in bracket 24 .
Within the housing 122 there is provided a cord guide 126 . Guide 126 is substantially semicircular with an annular groove 127 for accommodating the cord loop 18 . The cord guide 126 is associated with a spring 128 . More particularly, groove 129 are provided to allow the cord guide 126 to move up and down within the housing 122 . A spring 128 is disposed between the cord guide 126 and a top 130 portion of housing 122 . As in the embodiment of FIGS. 3A-3C, the cord guide is biased downwardly by the spring 128 . Preferably, housing part 122 A is formed with tracks 131 . The cord guide 126 is constructed so that it can move up and down on the tracks 131 within the housing 122 .
Importantly, the housing part 122 B is formed with a horizontal slot 132 . A similar slot 134 is provided in the cord guide 126 and a third slot 136 is formed in the housing part 122 A as shown. The cord guide 126 can be positioned between the housing portions 122 A, 122 B so that the three slots 132 , 134 , 136 are aligned to receive and accommodate a tab 140 . As seen in FIG. 4, the tab 140 is formed of a front portion 142 which is relatively flat and an intermediate portion 144 and a rear portion 146 . The front and rear portions 142 , 146 are substantially parallel and the intermediate portion 144 is perpendicular to the end portion and is sized and shaped to fit through slots 132 , 134 , 136 . The front portion 142 is large enough so that it can be imprinted with some instructions.
When the tensioning device 120 is completely assembled, the front and rear portions 142 , 146 of tab 140 are abutting the housing portions 122 B, 122 A, respectively, with the intermediate portion 144 extending through the housing portions 122 B, 122 A and the cord guide 126 , as seen in FIGS. 7 and 8. As shown in FIG. 5, in this position the cord guide 126 is pushing upwardly against the spring 128 so that the spring is somewhat compressed. Thus, tab 140 defines an installation position for the cord guide 126 in which the guide can travel a large distance vertically upward before coil 128 is completely compressed.
The tensioning device 120 is shipped with the tab 140 in place and the cord guide 126 locked in the installation position, as defined above, and shown in FIG. 8 A. When the tensioning device 120 is received, it is first installed on its bracket 24 while the tab 140 is in place, as shown in FIG. 8 B. The installer is instructed to insure that the bracket should be positioned to insure that the cord loop 18 is relatively taught, not loose. Because the tab 140 prevents movement of the cord guide 126 , the spring 128 does not yet apply any force on the cord loop 18 .
The tab 140 is made of an elastic material so that as the front portion 142 is pulled forward, the rear portion 144 is bent and can be retrieved through the slots 132 , 134 , 136 . The tab 140 can be made of paper or plastic. Once the tensioning device 120 is properly installed, the tab 140 is removed, as shown in FIG. 8 C. As soon as the tab is removed, the cord guide 126 is pushed down by the spring 128 thereby tensioning the cord loop 18 to the proper level. Moreover, if the cord loop 18 gets shorter because of shrinkage or other reason, the cord guide 126 automatically rises to compensate for this effect. However, because in its initial or installation position, the cord guide 126 is positioned at the bottom of the housing 120 , there is sufficient room in the housing to allow the cord guide 126 to rise applying excessive tension on the cord loop 18 and disabling the whole apparatus.
In the embodiment of FIGS. 4-8, the cord guide 126 provides groove 127 through which the cord loop 18 can slip. In order to reduce friction, the cord guide 126 can incorporate a pulley 126 A, as shown in FIG. 9 . The pulley 126 A is formed with a slot 134 A to accommodate a tab as described above. In addition, as shown in FIG. 9, instead of a compression-type spring 18 , a tension spring 28 A can be used to bias the pulley 126 downwardly. Of course, a similar tension spring 28 A may also be used for the embodiments of FIGS. 4-8.
The pulley 126 A is rotatably supported by a bracket 133 which is then connected to the end of spring 128 A. The slot 134 A may be provided in the bracket 133 rather than the pulley 126 A.
The tensioning device described herein is advantageous because it insures that the cord loop is properly tensioned at installation. Moreover, if the tension on the cord loop changes, for example, due to changes in the physical characteristics of the cord loop, the device automatically adjusts itself by allowing the cord guide or pulley to shift.
The tab can also be made of a relatively stiff material, in which case it is inserted into the housing through the slots and can be selectively removed therefrom without necessary bending any of its portions.
While the invention has been described with reference to several particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles of the invention. Accordingly, the embodiments described in particular should be considered as exemplary, not limiting, with respect to the following claims.
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A tensioning device for the cord loop of a window treatment apparatus includes a cord guide disposed in a housing, a biasing element such as a spring and a locking member that locks the cord guide into an installation position. During installation, the cord guide is fixed so that it cannot move and does not affect the tensioning of the cord. After installation, the locking member is removed and the cord guide can move in one direction or another to properly tension the cord.
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FIELD OF THE INVENTION
The present invention relates generally to non-chromate coatings for metals. More particularly, the present invention relates to a non-chromate coating for aluminum and Galvalume (a trademark of Bethlehem Steel for zinc - aluminum galvanized steel) which improves the adhesion of siccative coatings to the surface. The present invention provides a dried in place coating which is particularly effective at treating aluminum to be formed.
BACKROUND OF THE INVENTION
The purposes of the formation of a chromate conversion coating on the surface of metals are to provide corrosion resistance, improve adhesion of coatings and for aesthetic reasons. The conversion coating improves adhesion of coating layers such as paints, inks, lacquers and plastic coating. A chromate conversion coating is typically provided by contacting metals with an aqueous composition containing hexavalent or trivalent chromium ions, phosphate ions and fluoride ions. Growing concerns exist regarding the pollution effects of the chromates and phosphates discharged into rivers and waterways by such processes. Because of high solubility and the strongly oxidizing character of hexavalent chromium ions, conventional chromate conversion processes require extensive waste treatment procedures to control their discharge. In addition, the disposal of the solid sludge from such waste treatment procedures is a significant problem.
Chromate free pre-treatment coatings based upon complex fluoacids and salts and metals such as cobalt and nickel are known in the art. U.S. Pat. No. 3,468,724 which issued to Reinhold discloses a composition for coating ferriferous and zinc metal which comprises a metal such as nickel or cobalt and an acid anion selected from the group sulfate, chloride, sulfamate, citrate, lactate, acetate and glycolate at a pH from 0.1 to 4.
While chromate free pretreatment coatings based upon complex fluoacids and polyacrylic acids are known in the art, they have not enjoyed widespread commercial acceptance. U.S. Pat. No. 4,191,596 which issued to Dollman et al, discloses a composition for coating aluminum which comprises a polyacrylic acid and H 2 ZrF 6 , H 2 TiF 6 or H 2 SiF 6 . The '596 disclosure is limited to a water soluble polyacrylic acid or water dispersible emulsions of polyacrylic acid esters in combination with the described metal acids at a pH of less than about 3.5.
PCT Publication No. WO 85/05131 discloses an acidic aqueous solution to be applied to galvanized metals which contains from 0.1 to 10 grams/liter of a fluoride containing compound and from 0.015 to 6 grams/liter of a salt of cobalt, copper, iron, magnesium, nickel, strontium or zinc. Optionally, a sequesterant and a polymer of methacrylic acid or esters thereof can be present.
U.S. Pat. No. 4,921,552 which issued to Sander et. al. discloses a non-chromate coating for aluminum which is dried in place and which forms a coating having a gravimetric weight of from about 6 to 25 milligrams per square foot. The aqueous coating composition consists essentially of more than 8 grams per liter dihydro-hexafluozirconic acid, more than 10 grams per liter of water soluble acrylic acid and homopolymers thereof, and more than 0.17 grams per liter hydrofluoric acid.
A process for applying a protective coating to aluminum, zinc and iron is disclosed in U.S. Pat. No. 3,682,713 to Ries et al. The coating consists essentially of from 0.1 to 15 grams per liter of complex fluorides of boron, titanium, zirconium and iron, from 0.1 to 10 grams per liter of free fluoride ions and from 0.5 to 30 grams per liter an oxidizing agent such as sodium N-nitrobenzene sulfomate. The solution has a pH of from 3.0 to 6.8 and is free of phosphoric acid, oxalic acid and chromic acid.
U.S. Pat. No. 4,136,073 which issued to Muro et al., discloses a composition and process for the pretreatment of aluminum surfaces using an aqueous acidic bath containing a stable organic film forming polymer and a soluble titanium compound. The disclosed polymers include vinyl polymers and copolymers derived from monomers such as vinyl acetate, vinylidene chloride, vinyl chloride, acrylic polymers derived from monomers such as acrylic acid, methacrylic acid, acrylic esters, methacrylic esters and the like; amino alkyl, epoxy, urethane-polyester, styrene and olifinic polymers and copolymers; and natural and synthetic rubbers.
SUMMARY OF THE INVENTION
The present invention provides a composition for and method of treating the surface of metals to provide for the formation of a coating which increases the adhesion properties of the metal surface. The coating formed by the present invention may be dried in place or rinsed. The composition of the present invention comprises: (a) a dihydro-hexafluorozirconic or dihydro-hexafluortitanic acid such as fluozirconic acid or fluotitanic acid, (b) a water soluble polymer selected from acrylic acid and homopolymers and copolymers thereof, and (c) a molybdate such as ammonium molybdate.
The invention also provides a method forming a dried in place conversion coating on a metal surface with an aqueous solution. The coating formed by the method of the present invention is effective at improving the adhesion properties of metals such as aluminum and Galvalume.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present inventors have discovered that an improved coating on articles of Galvalume or aluminum or alloys thereof can be formed by an aqueous coating solutions comprising a water soluble polymer selected from acrylic acid and homopolymers and copolymers thereof, a dihydro-hexafluozirconic acid or dihydro-hexafluotitanic acid and a molybdate. The combination was found to provide an aqueous pretreatment agent for the treatment of aluminum and Galvalume which provides for an improved adhesion of later applied coatings when the treatment is dried in place. The treatment of the present invention can optionally be rinsed after application as by a water bath or shower.
Useful polymers within the scope of the present invention include water soluble as well as water dispersible polymers. Preferrably, the polymer is a homopolymer of acrylic acid and it is believed that water soluble copolymers of acrylic acid will also be effective. In the preferred embodiment, the polymer is polyacrylic acid having a molecular weight of about 5,000 to about 500,000. The polymer comprises from about 10 to 60 weight percent of the aqueous acidic composition of the present invention.
The aqueous acidic composition of the present invention also includes a dihydro-hexafluozirconic or dihydro-hexafluotitanic acid. It is believed that fluosilicic acids would be similarly effective. The fluozirconic or fluotitanic acid comprises from about 10 to 60 weight percent of the aqueous acidic composition of the present invention.
The aqueous acidic composition of the present invention also includes a molybdate such as ammonium molybdate. The molybdate comprises from about 0.2 to 20 weight percent of the aqueous acidic composition of the present invention.
The composition of the present invention provides an effective dried in place conversion coating solution. The composition is preferably supplied as a concentrate to be diluted for use. The concentrate may comprise from about 10 to 60% by weight the fluozirconic or fluotitanic acid component, from about 0.2 to 20% by weight the molybdate component, and from about 10 to about 60% by weight the polyacrylic acid component and the balance water. The concentrated solution may be diluted to from about 1 to 50% by volume in water prior to use. The pH of the resulting dilution is about pH 2. The pH of the dilution may be adjusted upward by the addition of an alkali such as ammonium hydroxide. Application of the composition to a metal surface may be through any conventional process including spray, immersion and roll coating.
The effectiveness of the composition and method of the present invention is demonstrated by the following examples. In these examples, the effectiveness was evaluated with a variety of adhesion tests familiar to those skilled in the art. Lacquered metal performance was evaluated by: gathering adhesion data after 15 minutes exposure to boiling Dowfax 2A1 surfactant (available from Dow Chemical Co.); delamination tests after two hours autoclave (15 psi and 115° C.) exposure to 1% lactic acids; and blistering resistance after a 24 hour exposure to 0.5% hydrochloric acid at 65° C. These tests are rated on a 0 to 10 scale.
Table 1 summarizes the treatments tested in the examples.
TABLE 1______________________________________Treat-ment Description______________________________________A dihydro-hexafluozirconic acidB dihydro-hexafluozirconic acids + soluble copolymers of acrylic acidC Composition of Present Invention (5% dilution)D Composition of Present Invention (pH 4, 5% dilution)E dihydro-hexafluozirconic acids + soluble copolymers of acrylic acid (tannin modified)F dihydro-hexafluozirconic acids + soluble copolymers of acrylic acid (pH 2.9)G dihydro-hexafluozirconic acids + soluble copolymers of acrylic acid (pH 2.9 post rinse)H dihydro-hexafluozirconic acid/phosphate/post rinsedI dihydro-hexafluotitanic acid/tannin/phosphate and rinsedJ chromium chromate (fluoride activated) post rinsedK complex oxide post rinsedL chromium phosphate (fluoride activated) post rinsed______________________________________
EXAMPLE 1
Aluminum alloy 5182 was cleaned with Betz DC-1675, a commercial alkaline cleaner available from Betz Laboratories, Inc., Trevose, Pa. Cleaning was followed by spray application of a variety of non-chromate treatments to the aluminum test panels. The applied solutions were allowed to dry in place. The treated test panels were coated with Dexter 8800A04M, a can end lacquer available from The Dexter Corporation. Table 2 summarizes the adhesion results.
TABLE 2______________________________________Treatment Feathering Lactic Acid HCl______________________________________A 9.9 0 10.0B 9.9 0 3.0C 9.9 8.0 10.0D 9.9 1.0 10.0______________________________________
EXAMPLE 2
Aluminum alloy 5052 was cleaned with Betz DC-1675 a commercial alkaline cleaner available from Betz Laboratories, Inc. Cleaning was followed by spray application of a variety of non-chrome treatments. The applied solutions were allowed to dry in place. The treated test panels were coated with a pigmented lacquer available from Valspar of Pittsburgh, Pa. Table 3 summarizes the adhesion test results.
TABLE 3______________________________________Treatment Lactic Acid HCl______________________________________A 10.0 8.0B 10.0 8.0C 10.0 10.0D 10.0 10.0______________________________________
EXAMPLE 3
Aluminum alloy 5182 was alkaline cleaned with Betz DC-1675 and treated by spray application of a variety of non-chrome treatments. The applied solutions were allowed to dry in place. The treated test panels were coated with Valspar 9835 a can end lacquer. In addition to the tests described above, the lacquered metal was formed into can lids and exposed to Diet Coke, Sprite, and beer for 30 days. This pack test evaluates lacquered metal under true beverage exposure conditions. After exposure, the lids were removed from the can bodies and inspected for blistering and adhesion loss. Table 4 summarizes the adhesion test results.
TABLE 4______________________________________Treatment Featherinq Lactic Acid HCl Pack Test______________________________________E 6.6 8.0 -- 2F 5.8 0.0 -- 2G 9.0 0.0 -- 0H 9.5 9.5 10.0 6I 9.8 9.5 5.5 4C 9.9 10.0 7.5 8D 10.0 9.5 7.5 2L 9.8 7.5 10.0 10______________________________________
EXAMPLE 4
The aluminum loading effect of treatment D was evaluated by processing over 700 square feet of aluminum alloy 5182 in 8 liters of treatment D on an aluminum foil line. Metal samples were taken at selected intervals and the aluminun content of the treatment solution was also measured. The metal samples were coated with Valspar Universal Lacquer 9835. The coated samples were evaluated as described above. Table 5 summarizes the test results.
TABLE 5______________________________________AluminumFt.sup.2Treated PPM in bath Feathering Lactic Acid HCl______________________________________ 0 66 9.9 9.5 10.0100 80 9.8 9.5 7.0233 133 9.8 9.5 8.0411 185 9.7 9.5 8.0605 206 9.5 10.0 6.0777 219 9.9 10.0 7.0______________________________________
EXAMPLE 5
The treatment of the present invention was also tested as a treatment for Galvalume. Chrome passivated Bethlehem Steel Galvalume was cleaned with a commercial alkaline cleaner (Betz Kleen 4004 available from Betz Laboratories, Inc., Trevose, Pa.). The alkaline cleaning was both with and without brushing. The cleaned test panels were treated with a variety of chrome treatments which were dried in place. For comparison purposes, several cleaned test panels were treated with a conventional chromate treatment (Treatment J) and chrome sealed with a dilute chromium solution. All of the treated panels were painted with an epoxy primer (Dexter 9X447) and top coated with a silicanized polyester paint (Dexter 79X3135). Performance was rated by T-bend, cross-hatch reverse impact (60 inch pounds) adhesion and neutral salt fog (ASTM B117). Table 6 summarizes the test results.
TABLE 6______________________________________ Neutral SaltTreatment T-Bend X-Hatch Scribe Field______________________________________J no brushing 2 3B 10 10K no brushing 2 3B 9 10C no brushing 2 3B 9 10C no brushing 2 3B 9 10J with brushing 2 3B 10 10K with brushing 2 3B 10 10C with brushing 2 3B 10 10C with brushing 2 2B 9 10______________________________________
The above examples show that the treatment composition of the present invention is more effective than known non-chrome pretreatments on aluminum and nearly matches known chrome pretreatments on aluminum. On Galvalume, the treatment composition of the present invention is as effective as known chrome pretreatments.
While the present invention has been described with respect to particular embodiments thereof, it is apparent that numerous other forms and modifications of the invention will be obvious to those skilled in the art. The appended claims and this invention generally should be construed to cover all such obvious forms and modifications which are within the true spirit and scope of the present invention.
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A non-chromate pretreatment for aluminum and zinc-aluminum galvanized steel is disclosed which comprises a polyacrylic acid or homopolymers and copolymers thereof, a molybdate, and a dihydrohexafluo acid.
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CROSS REFERENCE
This is a U.S. patent application of U.S. provisional application 60/811,925, filed Jun. 8, 2006 for a Apparatus and Method for Coil Cooling, which is hereby fully incorporated by reference.
FIELD OF THE INVENTION
The present invention relates to a portable cooling device including an air source, such as a fan, that provides air flow, and a shroud for directing air flow from the air source at an article, particularly (a) a coil of material or (b) a non-coil metal article such a sheet, plate or ingot, having a temperature greater than the ambient room temperature. The cooling device provides cooling efficiency by directing the air from the air source at an increased velocity to a desirable area or areas on a surface of the object, thereby increasing heat transfer from the object. The cooling device shroud includes an air directing surface that influences the direction of air flow across the object in a desired pattern. Methods for preparing cooling devices and for cooling objects, particularly coils, are also described.
BACKGROUND OF THE INVENTION
In the metallurgical or metalworking field, sheets or pieces of a metal or metal alloy are processed in any number of ways that can raise the temperature of the sheet above the temperature of the ambient room temperature. The processed sheets are subsequently rolled into a coil. For example, sheets that have been treated using a cold rolling process can reach temperatures above 200° C. during the process. Heat treatments utilized to treat sheets include, but are not limited to, continuous annealing/solution heat treatment (SHT) and batch annealing. During a continuous annealing/SHT process, the sheet is uncoiled and then first passed through a furnace section and then a quench section. For some metals or alloys, the sheet comes off the quench at higher than room temperature. During batch annealing, the entire coil is placed in a furnace where it is heated to a predetermined temperature and held for a predetermined period of time, such as several hours, after which the coil is removed and allowed to cool.
Following a procedure such as, but not limited to, one of the above described procedures, it is often necessary to cool the sheet coils to ambient room temperature either as a final step prior to storing/shipping or the like, or in preparation for a subsequent step in a manufacturing sequence.
One current practice in the art is to provide forced air cooling by positioning an axial flow fan adjacent a coil and directing air flow at the coil. The air flow is generally perpendicular to the horizontal axis of the coil at the surface of the coil end, and the velocity of air is limited by the air exit velocity of the fan. When the coil has a hollow core or center, some of the air passes through the coil center and therefore does not contribute significantly to coil cooling. Furthermore, some of the air passes along the outside of the coil diameter and also does not provide efficient heat transfer.
SUMMARY OF THE INVENTION
The cooling device of the present invention comprises an air source and a shroud connected to the air source. The shroud includes an air directing surface having one or more apertures in an arrangement adapted to direct air from the air source at a predetermined area or areas on a surface of an article, such as a coil or a non-coil article, preferably of a metal or metal alloy. The shroud is utilized to direct air flow across a surface of the article to achieve more efficient cooling when compared to using the air source alone. In one embodiment, the shroud design increases the air velocity to a value greater than the velocity exit value from the air source such as a fan. In a further embodiment, the shroud includes an adaptor that allows the device to be utilized on a coil without a core, on a coil with a core, or with a coil having a mill spool which extends out beyond the plane of the coil sidewall or end. The adaptor prevents air from passing through the center of the coil.
In one embodiment, a cooling device having an air source is provided. A shroud of the device is positioned adjacent one lateral end of a coil, wherein air from the air source is directed through one or more apertures of an air directing surface of the shroud onto a surface of the coil, preferably near the inner diameter of the coil. The air flows in a gap between the surface of the coil and the air directing surface of the shroud toward the outer diameter of the coil, escaping along the end of the shroud or outer diameter of the coil. In another embodiment, the shroud air directing surface has an outer perimeter formed as an annulus, preferably having a diameter similar to the diameter of the coil. In a preferred embodiment, the adaptor of the shroud prevents air from flowing through the center of the coil.
It is, therefore, an object of the present invention to provide a cooling device that is mobile, portable, and can be easily positioned in relation to a coil in order to cool the coil for further handling or processing or a combination thereof.
A further object of the present invention is to provide a cooling device and method for utilizing the cooling device that improves heat transfer and cooling efficiency when compared to the prior art practice of providing forced air cooling by directing air from an axial flow fan at the lateral end of a coil.
Yet another object of the present invention is to provide a cooling device that is adapted to be utilized on a coil free of a core, on a coil with a core, or on a coil having a mill spool which extends out beyond the plane of an end of a coil.
Still another object of the present invention is to provide a shroud that can be easily retrofitted to an existing fan.
It is a further object of the present invention to provide a cooling device that utilizes air from an air source, increases the velocity of the air exiting the air source, and directs the air at a location near the inner diameter of a coil and subsequently along the surface of the coil.
Accordingly, one aspect of the present invention is a cooling device for use in cooling an article, comprising an air source that provides air flow, and a shroud that receives air flow from the air source and is adapted to direct the air onto a surface of the article, wherein the shroud includes a receiver that is connected to an air exhaust outlet of the air source, wherein the shroud includes an air directing surface having one or more apertures through which air flows out of the shroud, and wherein the one or more apertures have a total cross-sectional area that is less than a cross-sectional area of the air exhaust outlet.
Another aspect of the present invention is a cooling device for use in cooling a coil of material, comprising an air source that provides air flow through an air exhaust outlet, and a shroud connected to the air source that receives air from the air source exhaust outlet and is adapted to expel the air through one or more apertures of an air directing surface of the shroud, wherein the shroud includes an adaptor connected to the air directing surface of the shroud and adapted to substantially seal a core of the coil to prevent air flow through the core.
Still another aspect of the present invention is a method for cooling a coil, comprising the steps of providing a coil of material at a temperature above an ambient temperature, providing a cooling device comprising an air source that provides air flow and a shroud that receives air flow from the air source and is adapted to direct the air onto a surface of the coil, wherein the shroud includes a receiver that is connected to an air exhaust outlet of the air source, wherein the shroud includes an air directing surface having one or more apertures through which air flows out of the shroud, positioning the air directing surface of the cooling device adjacent an end of the coil, and directing air from the cooling device onto the coil end to cool the coil, wherein a velocity of the air exiting the one or more apertures is greater than a velocity of the air exiting the air exhaust outlet.
Yet another aspect of the invention is a cooling device for use in cooling an article, comprising an air source that provides air flow; and a shroud that receives air flow from the air source and is adapted to direct the air onto a surface of the article, wherein the shroud includes a receiver that is connected to an air exhaust outlet of the air source, wherein the shroud includes an air directing surface having one or more apertures through which air flows out of the shroud, wherein the air directing surface is substantially planar radially outward of an adaptor connected to the air directing surface and wherein the air directing surface is adapted to be positioned substantially parallel to a plane formed by an end of the article.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood and other features and advantages will become apparent by reading the Detailed Description of the Invention, taken together with the drawings, wherein:
FIG. 1 is a side elevational view, in partial cross-section, of one embodiment of a cooling device of the present invention positioned adjacent to the lateral end of a coil;
FIG. 2 is a partial side elevational schematic view of the cooling device of the present invention, particularly illustrating air flow through apertures of the device onto a surface of a coil;
FIG. 3 is an elevational front view of one embodiment of a shroud of a cooling device of the present invention taken through line 3 - 3 of FIG. 1 , particularly illustrating an air directing surface having apertures through which air can flow; and
FIG. 4 is a side elevational view, in partial cross-section, of one embodiment of a cooling device of the present invention having a flexible shroud, positioned adjacent to the lateral end of a coil.
DETAILED DESCRIPTION OF THE INVENTION
This description of preferred embodiments is to be read in connection with the accompanying drawings, which are part of the entire written description of this invention. In the description, corresponding reference numbers are used throughout to identify the same or functionally similar elements. Relative terms such as “horizontal,” “vertical,” “up,” “down,” “top” and “bottom” as well as derivatives thereof (e.g., “horizontally,” “downwardly,” “upwardly,” etc.) should be construed to refer to the orientation as then described or as shown in the drawing figure under discussion. These relative terms are for convenience of description and are not intended to require a particular orientation unless specifically stated as such. Terms including “inwardly” versus “outwardly,” “longitudinal” versus “lateral” and the like are to be interpreted relative to one another or relative to an axis of elongation, or other axis, as appropriate. Terms concerning attachments, coupling and the like, such as “connected” and “interconnected,” refer to a relationship wherein structures are secured or attached to one another either directly or indirectly through intervening structures, as well as both movable or rigid attachments or relationships, unless expressly described otherwise. The term “operatively connected” is such an attachment, coupling or connection that allows the pertinent structures to operate as intended by virtue of that relationship.
Referring now to the drawings, the cooling device 10 of the present invention includes an air source 20 operatively connected to a base 50 in one embodiment as shown in FIG. 1 . Air source 20 is utilized to generate or create air flow at a velocity for use by cooling device 10 . Air source 20 is generally a fan having a housing 22 , an air intake 23 , and an air exhaust outlet 24 . Air source 20 further includes a motor 25 operatively connected to housing 22 . Motor 25 is preferably an electric motor operatively connected to an electrical switch. In one embodiment, motor 25 is operable at one or more different speeds.
An impeller or propeller 26 is operatively connected to an output shaft of motor 25 . Propeller 26 includes one or more fan blades utilized to draw air into air intake 23 and expel the same through air exhaust outlet 24 . The described air source 20 is known to those of ordinary skill in the art and is commercially available from sources such as Universal Fan and Blower of Bloomfield, Ontario, Canada and Continental Fan of Buffalo, N.Y., USA. There are generally no limitations regarding the horsepower of the fan, so long as the desired air flow is provided to cool a coil 100 . A fan having a horsepower of less than 10 is utilized in this application in one embodiment to maintain ease of portability. In a preferred embodiment, an air source is utilized that is capable of maintaining relatively low flow rates at medium to high pressure without stalling or overloading, with an appropriate shroud design.
During use, a motor switch is actuated and motor 25 is energized, thereby producing rotation of propeller 26 . The rotation of propeller 26 draws air inwardly through air intake 23 and discharges the air through exhaust outlet 24 .
While the air source 20 described hereinabove is generally known in the art as an axial flow fan, any other air source such as a blower, a pump such as a rotary or centrifugal pump, a compressor, centifugal-blower or fan, tube-axial fan, or mixed flow fan, or the like can be utilized to provide a desired volume of air at a desired velocity to shroud 30 of cooling device 10 .
Shroud 30 is connected to air source 20 and receives air expelled from exhaust outlet 24 , as shown in FIG. 2 . Receiver 32 of shroud 30 extends around a perimeter of air exhaust outlet 24 and channels air through one or more internal guide vanes 33 into interior 34 of shroud 30 . The connection between receiver 32 of shroud 30 and air exhaust outlet 24 or housing 22 of air source 20 is airtight or substantially airtight in order to provide efficiency of airflow through cooling device 10 . Any means known in the art can be utilized to connect shroud 30 to air source 20 , such as a pressure fit, a latch, fasteners such as screws or nuts and bolts, adhesive, or the like, with a latch being preferred. In one embodiment, receiver 32 is an annular rim or flange conforming to the perimeter of air exhaust outlet 24 which typically has an annular opening.
Shroud 30 includes a body 36 that extends between receiver 32 to the shroud air directing surface 40 as shown in FIGS. 1 and 2 . Shroud body 36 as illustrated is formed as a frustoconical structure. A first end of body 36 , namely at receiver 32 forms a plane that is generally parallel to a plane at the second end of body 36 at air directing surface 40 . Body 36 is not limited to the frustoconical shape shown, but can have any other desired configuration so long as receiver 32 is connected to air directing surface 40 . Accordingly, body 36 can be cylindrical, rectangular, square, or the like, or combinations thereof. The function of body 36 is to transfer air received from air exhaust outlet 24 through apertures 42 of air directing surface 40 .
In a preferred embodiment, the direction of air flow 60 is changed from horizontal, i.e. the direction of air flow entering outlet 24 from air source 20 , towards a direction substantially perpendicular or perpendicular thereto, such as shown in FIG. 2 , in a gradual fashion to minimize the pressure drop and maximize the air velocity through the shroud 30 . Air flow channeling and directing is particularly important in an application utilizing an axial fan which typically does not develop high pressure. Use of guide vanes 33 attached to the shroud 30 to help direct the air flow, such as shown in FIG. 2 is preferred in one embodiment. Cap or adaptor 44 , as described hereinbelow, can also be contoured to aid in directing air flow. Known design principles of fluid dynamics can be applied to design the shape required for each application. In one embodiment, one or more air directing vanes such as spiral swirl vanes 43 , as shown in FIG. 3 , are incorporated on the coil side of the shroud 30 to increase the contact time and contact area of the cooling air with the coil 100 .
In a preferred embodiment, several straight or curvilinear vanes 43 , preferably of the same width as projection 46 , are attached to the air directing surface 40 and extend from the edge of the air exit openings towards the outer diameter or perimeter 48 and cause the air to take a curving path across the coil face. Also, the distance maintained between the coil 100 and the shroud 30 is very important in the process for cooling a coil 100 , and depends on the fan characteristics, i.e. pressure vs. flow, generally known as the fan characteristics curve. Accordingly, the distance between the coil 100 and shroud 30 , such as at air directing surface 40 , can be varied depending on the application.
In a further embodiment, shroud 30 is a substantially solid structure, but can include flexible elements in order to provide a desired air flow to a coil 100 . Portions of the shroud 30 can be formed of generally any suitable material offering a desired rigidity or form, including, but not limited to, a polymer, a rubber, or an elastomer, either thermoplastic or thermoset, such as PVC; or any suitable metal. A requirement of shroud 30 is that the material chosen must be suitable in order to withstand and substantially not deform, degrade or the like, at the temperature of the coil 100 to be cooled, for a period of time.
As stated herein above, shroud 30 includes air directing surface 40 connected to body 36 . Air directing surface 40 is adapted to be placed in close proximity to a coil 100 as illustrated in FIG. 1 in order to aid in heat transfer and cooling of the coil to a preferred temperature such as room temperature. Air directing surface 40 has a configuration adapted to direct air flow across a surface of the coil, preferably between coil lateral end surface 102 and the outer surface of air directing surface 40 .
Air directing surface 40 includes one or more apertures 42 . As illustrated in FIG. 3 , a plurality of apertures 42 are shown arranged around an adaptor 44 in the radial interior portion of air directing surface 40 . Any number of apertures can be utilized with, generally from 1 to about 16, desirably about 6 to about 10, and preferably about 8 apertures present. It is desirable in one embodiment of the present invention that the cross-sectional area of all of the apertures present on air directing surface 40 be less than the cross-sectional area of the air exhaust outlet 24 in order to provide an increase in air velocity through the apertures collectively when compared to air exhaust outlet 24 in order to provide improved heat transfer between the air and the coil, according to heat transfer theory.
In a preferred embodiment, a plurality of apertures 42 are spaced around the circumference of adaptor 44 . In this alignment, the air flowing out of apertures 42 is directed onto the interior portion of lateral end surface 102 of coil 100 adjacent to spool 104 thereof. As illustrated in FIG. 2 , air flow travels along lateral end surface 102 radially outwardly toward the outer diameter of coil 100 . The size and number of apertures are matched to the fan characteristics curve and shroud design. In one embodiment, the total area of the apertures ranges generally from about 50% to about 90%, desirably about 60% to about 70%, and preferably about 66% of the area of the air exhaust outlet 24 . The area of an imaginary annular cylinder extending between the coil end and the shroud at the outer diameter of the apertures is preferably 1 to 3 times less and most preferably 1.5 times less than the total area of the apertures. In a preferred embodiment, adaptor 44 includes projection 46 extending outwardly from air directing surface 40 and is adapted to be placed near and preferably abutted against coil 100 . Preferably, projection 46 is substantially annular, or annular with a perimeter thereof extending completely around the coil core or mill spool 104 . The diameter of the projection is dependent on the size of the core or mill spool 104 . Accordingly, air is prevented from passing through the core of coil 100 or mill spool 104 about which coil 100 is wound. Projection 46 is further adapted to allow for a portion of a coil core such as a mill spool to be situated therein, should the mill spool 104 extend beyond the end of the coil 100 .
Perimeter 48 of air directing surface 40 is preferably annular although it is to be understood that other shapes or designs can be utilized. Annular perimeter 48 is utilized as the same is complimentary to the shape of lateral end surface 102 of coil 100 which is also typically annular. In one embodiment, an annular perimeter 48 has a diameter that is about 5% less than the diameter of a coil 100 , and at a minimum, is about 66% of the distance between the coil inner diameter and the coil outer diameter. The cooling device is situated adjacent the coil in one embodiment such that the area of the imaginary annular cylinder extending between the coil and the shroud at the outer diameter of the apertures 42 is preferably about 20% to about 60% of the area of exhaust outlet 24 .
Base 50 or other suitable mount is utilized to support air source 20 and shroud 30 . The structure of base 50 is not critical, so long as the air source 20 and shroud 30 are supported and allowed to perform their intended functions. In one embodiment as illustrated in FIG. 1 , base 50 includes one or more legs interconnected by a frame 54 . In a preferred embodiment, base 50 includes one or more wheels 56 that are operatively connected to frame 54 , or leg 52 as shown in FIG. 1 . Wheels 56 of base 50 allow cooling device 10 to be portable and easily moved to a desired position in relation to a coil or other object to be cooled. Wheels, if any, are provided with a lock to prevent the fan from moving away from the coil due to pressure in a preferred embodiment. Base 50 is constructed of any suitable materials or combinations of materials including, but not limited to, metal, polymer, wood, or the like.
In one embodiment such as shown in FIG. 4 , a cooling device 210 is provided having a shroud 230 having at least a portion thereof that is flexible. When shroud body 236 or other portion of shroud 230 is flexible, on either all or a part thereof, various materials can be utilized, including, but not limited to, plastic or fabric such as fabric including ducting with a support such as a spiral-wound spring-wire, or the like.
Flexible shroud 230 includes a receiver 232 that is connected to air exhaust outlet 224 of axial fan 220 to receive air therefrom and direct air into interior 234 of shroud 230 . As described above, axial fan 220 includes an air inlet 223 , motor 225 and propeller 226 . The end of flexible shroud 230 generally opposite axial fan 220 is detachably connected to an air directing surface 240 via a locking mechanism 245 that permits quick disassembly for ease of handling. Air directing surface includes an adaptor 244 and one or more projections 246 of adaptor 244 that can be operatively attached to a spool plug component that optionally extends outwardly from the coil. The adaptor 244 can be moved towards or away from the coil to make a desired seal with the spool 104 . As also described hereinabove, air directing surface 240 includes one or more apertures 242 that direct air into the coil 100 . Air directing surface 240 can include one or more air directing vanes as described hereinabove.
Adaptor 244 in one embodiment as shown in FIG. 4 has an elongated, preferably annular, projection 246 that extends into mill spool 104 , that is also typically annular. The elongated projection 246 has a length sufficient to support air directing surface 240 on coil 100 . In a preferred embodiment, the elongated projection 246 has an outer diameter slightly less than the inner diameter of mill spool 104 for a snug or friction fit.
Adaptor 244 provides support for air directing surface 240 and can rest on mill spool 104 or otherwise be operatively connected thereto.
The flexible shroud 230 advantageously allows the cooling device 210 to be utilized on coils having different core heights above a ground surface. For example, in one embodiment, air directing surface 240 is operatively connected to a core of a coil to be cooled such as shown in FIG. 4 , with the core situated at a particular height above the ground surface due to the radius of the coil as well as the height of any object the coil is situated on, if any. Depending on the height of the air directing surface 240 operatively connected to the coil, the end of flexible shroud 230 opposite receiver 230 is moved upward or downward and subsequently connected to air directing surface 240 using locking mechanism 245 . Accordingly, depending on the height of the core above a ground surface, the outer surface of flexible shroud body 236 between receiver 232 and air directing surface 240 can have a curved appearance.
Cooling device 210 includes a base 250 that supports air source 220 . In one embodiment, base 250 includes one or more wheels 256 operatively connected to frame 254 or leg 252 such as shown in FIG. 4 . As described hereinabove, wheels 256 can be provided with a lock to prevent the fan 220 from moving away from the coil 100 .
In order to utilize cooling device 10 of the present invention, cooling device 10 is moved into a desired position in relation to a coil 100 , such as illustrated in FIGS. 1 and 2 . Preferably, projection 46 is aligned over or around spool 104 of coil 100 forming a seal to prevent air flow therethrough. Air source 20 is actuated and air flows through air exhaust outlet 24 into interior 34 of body 36 of shroud 30 . Air flows out of interior 34 through one or more apertures 42 toward lateral end surface 102 of coil 100 . Since the air flow cannot deeply penetrate lateral end surface 102 , the forced air continues to flow radially outward toward the outer diameter of coil 100 between air directing surface 40 and lateral end surface 102 . The air flow is generally perpendicular to the horizontal axis of the coil. Shroud 30 increases air velocity from the air source, thereby increasing the heat transfer. In an alternative embodiment, the power required for the air source 20 may be reduced for equivalent cooling capacity since utilization of the cooling air is more efficient. Shroud 30 and base 50 can be easily retrofitted to existing air source 20 .
Articles that can be cooled by the present invention include any material, such as a coil or a non-coil article, preferably a metal or metal alloy. Non-coil metal articles include examples such as a sheet, plate, or ingot. Sheet material utilized to form coil 100 can have any thickness. However, in general air cooling of the type desired herein is most efficient with thinner material due to the larger number of windings per coil. Air gaps and surface roughness between laps tend to provide an insulating effect. The more of these discontinuities there are, the more heat movement and thus cooling is favored in the axial direction. In a preferred embodiment, coil 100 is aluminum or an aluminum alloy. Generally any of the numerous one or more 1xxx through 9xxx series alloy articles such as, but not limited to, sheets, plates, coils, and ingots according to the Aluminum Association Designation for Wrought Aluminum Alloys can be utilized. Coil 100 preferably has a side surface 106 having a perimeter that is circular, although side surfaces of other configurations which are not circular, but are substantially circular, oval, or the like can also be utilized. As described herein, coil 100 can have a center or core comprising a spool 104 that is hollow or solid. Coil 100 can be wound upon a mill spool 104 which can be of any suitable composition such as steel, aluminum or fiber. While coil 100 can generally have any diameter, typical diameters range from about 76.2 cm (30 inches) to about 25.40 cm (100 inches), and spools typically vary between about 20.3 cm (8 inches) to about 122 cm (48 inches), but can be smaller or larger.
In accordance with the patent statutes, the best mode and preferred embodiment have been set forth, the scope of the invention is not limited thereto, but rather by the scope of the attached claims.
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A cooling device including an air source, preferably a fan, that provides air flow and a shroud for directing air flow from the air source at an object, particularly a coil of material, preferably a metal or metal alloy having a temperature greater than the ambient room temperature. The cooling device provides cooling efficiency by directing the air from the air source at an increased velocity to a desirable area or areas on an end surface of the object, thereby increasing heat transfer from the object. The cooling device shroud includes an air directing surface that influences the direction of air flow across the object in a desired pattern. Methods for preparing cooling devices and for cooling objects are also described.
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This application is a divisional of U.S. application Ser. No. 09/586,616, filed Jun. 2, 2000, which is a continuation of International Application No. PCT/CA98/01126, entitled “BREATHING MASK FOR A HELMET”, filed on Dec. 3, 1998. The International Application claims priority to Canadian Patent Application No. 2,223,345, entitled “BREATHING MASK FOR A HELMET”, which was filed on Dec. 3, 1997, the entire contents of which are hereby incorporated by reference in their entirety.
FIELD OF THE INVENTION
The invention relates to a breathing mask for a helmet which is particularly well suited for use when the temperature is below a certain point, i.e. the point under which the breath of an operator condenses inside the helmet and causes the advent of water on the lens of the eyeglasses of the operator or on the shield of the helmet.
BACKGROUND OF THE INVENTION
A prior art helmet comprises a first part which protects the head of a wearer, as a conventional helmet; a second part, which is integrated with and forms a projection with the first part and protects the lower part of the face of the wearer, more particularly the jaw; and a shield, which is situated between an upper front section of the first part and an upper section of the second part to protect the face of the wearer.
Due to its structure, the helmet has a small interior chamber where the wearer can breath. This interior chamber is usually insulated from the atmosphere to protect the wearer from cold air. At a certain temperature, air which contains saturated particles of water will condense and create condensation. Because the temperature of the lens of the eyeglasses of the operator wearing the helmet or the shield of the helmet can reach the condensation point of the breath of the wearer, water will form on the eyeglass lens or on the shield.
In order to avoid the problem of condensation, it is possible to open the shield to allow outside air to flow into the helmet until condensation is eliminated. This however presents a problem in that the wearer may be exposed to cold air which is uncomfortable and may be dangerous to health. Furthermore, the wearer has to use one hand to open the shield which may be hazardous when he or she is steering the vehicle being driven. The shield could also involuntarily close by impact or sudden movement. Thus, there is a need to provide a device which is capable of avoiding or eliminating the condensation created inside a full face helmet.
A prior art helmet provides some protection against sun rays. However, the shield of a prior art helmet is either clear or tinted and no adjustment of the tint is possible. On a bright sunny day, the wearer of a prior art helmet must also wear tinted eyeglasses to protect himself against the intensity of light if the shield of his helmet is clear. In changing weather conditions, the wearer may have to put the tinted eyeglasses on and off as the intensity of light changes. Thus, there is also a need to provide a helmet adapted to adjust the protection of the eyes of the wearer from sun rays.
OBJECTS AND STATEMENT OF THE INVENTION
It is an object of the present invention to provide a breathing mask for a helmet which reduces the formation of water on the lens of eyeglasses or the shield of the helmet.
It is an object of the present invention to provide a helmet that overcomes or at least reduces the deficiencies associated with a prior art helmet.
It is another object of the present invention to provide a helmet comprising a breathing mask which reduces the formation of water on the lens of eyeglasses or the shield of the helmet.
A further object of the invention is to provide a helmet including a tinted inner shield which is adapted to adjust the protection of the eyes of the wearer from sun rays as he or she requires.
As embodied and broadly described herein, the invention provides a breathing mask adapted to fit the contours of the face of a wearer, said breathing mask adapted to be mounted to a helmet, said breathing mask comprising at least one breathing channel through which air may circulate and a binding member; said at least one breathing channel adaptable to said helmet and said binding member adapted to connect and secure said breathing mask to said helmet, and to position said breathing mask in relation to said face.
As embodied and broadly described herein, the invention provides a helmet adapted to receive and retain a breathing mask, said helmet comprising:
a head portion;
a jaw shield mounted to said head portion, said jaw shield including at least one passage adapted to receive an exterior end of said breathing channel,
a binding member adapted to secure said breathing mask to said helmet, whereby the breathing mask is substantially hermetically adapted to the face of the wearer and the breath of the wearer may be expelled from inside said jaw shield.
In a preferred embodiment of the present invention the novel helmet comprises a head portion adapted to protect the head of the operator, a shield portion comprising a jaw shield adapted to protect the lower portion of the face of the wearer or operator; the shield portion being mounted to the head portion and adapted to move from an open position to a closed position and a optional latching mechanism which locks the jaw shield of the shield portion to the head portion. The optional latching mechanism is actuated with two lever buttons located at the front of the jaw shield and sufficiently close to one another so that one hand can actuate both buttons and in the same movement pull the jaw shield from the closed position to the open position. The jaw shield has passages that are connected, when the jaw shield is in the closed position, to a breathing mask through flexible tubes thereby linking the breathing mask to the outside through which the wearer may breath and the moisture content of his or her expelled breath can circulate and be evacuated. This arrangement prevent or at least greatly reduces condensation and fogging of the eye shield of the shield portion and of the eyeglasses of the wearer.
The breathing mask comprises a mask body, surrounding the nose and mouth of the wearer and including a port on each side adjacent the mouth; a flexible tube which connects said port to said passage when said face portion is in the closed position, a binding member adapted to secure said breathing mask to said helmet, and resilient straps.
The binding member connects said breathing mask to the helmet, wherein said breathing mask is substantially hermetically adapted to the face of the wearer and the breath is restricted from entering the inside chamber. The binding member is preferably a snap-holder located at one end of the flexible tubes. The binding member may also be a hook and loop (velcro) device, a clip or a strap; all these elements being capable of connecting and securing the breathing mask to the head portion of the helmet.
Advantageously, the shield portion further comprises an eye shield including a see-through shield and a tinted shield; said tinted shield being movable from a first position to a second position, said tinted shield adapted, in said first position, to be housed and partially hidden inside an upper chamber, and in said second position, to be in front of the eyes of the wearer whereby said tinted shield protects the eyes of the wearer from intense light. The tinted shield includes a lever protruding from a narrow slot of the upper chamber, this lever is adapted to maneuver said tinted shield from said first position to said second position.
As embodied and broadly described herein, the invention also provides a filter for a breathing mask comprising a thin layer of material adapted to isolates the skin of a wearer from said breathing mask, said layer of material shaped to fit a given contour of said breathing mask.
Another object of the invention is to provide a filter adapted to be positioned between the mask body and the face of the wearer whereby said filter isolates the skin of the wearer from the breathing mask. Advantageously, the filter is a supple thin cloth of felt-like material.
As embodied and broadly described herein, the invention also provides a breathing mask kit comprising:
a mask body adapted to fit the contours of the face of a wearer, said mask body including at least one port;
at least one hollow flexible tube including an interior end and an exterior end;
a binding member including an aperture; said binding member adapted to secure said breathing mask to a helmet and to align said aperture with a passage on said helmet;
said interior end being adapted to engage said at least one port of said mask body and said exterior end being adapted to engage said aperture of said binding member whereby when said at least one hollow flexible tube is engaged to said at least one port of said mask body and to said aperture of said binding member, said at least one hollow flexible tube acts as a conduit through which the breath of a wearer may circulate.
Other objects and features of the invention will become apparent by reference to the following description and the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
A detailed description of the preferred embodiments of the present invention is provided herein below, by way of example only, with reference to the accompanying drawings, in which:
FIG. 1 is a perspective view of a full face helmet constructed in accordance with the invention;
FIG. 2 is a side elevational view of a full face helmet constructed in accordance with the invention;
FIG. 3 is a perspective exploded view of a breathing mask constructed in accordance with the invention;
FIG. 4 is a front elevational view of the breathing mask constructed in accordance with the invention;
FIG. 5 is a side elevational view of the full face helmet showing the full face helmet in an open position worn by a wearer with the breathing mask partially removed;
FIG. 6 is a side elevational view of a full face helmet in an open position worn by a wearer with the breathing mask put on;
FIG. 7 is a side elevational view of a full face helmet worn by a wearer with the jaw shield lowered into the closed position and the shield in the open position;
FIG. 8 is a front elevational view of the full face helmet constructed in accordance with the invention;
FIG. 9 is a side elevational view of the eye shield removed from the full face helmet; and
FIG. 10 is a side elevational view of the full face helmet showing the motion of the shield portion.
In the drawings, preferred embodiments of the invention are illustrated by way of examples. It is to be expressly understood that the description and drawings are only for the purpose of illustration and are an aid for understanding. They are not intended to be a definition of the limits of the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Referring now to the drawings, FIGS. 1 and 2 illustrate the novel helmet which is generally designated by the reference number 10 . The helmet 10 comprises a head portion 12 , a shield portion 13 pivoting about axis A, and having a pair of passages 16 through which the breath of a wearer may circulate, a see-through shield 18 , an inside chamber 20 , a breathing mask 22 , and a pair of lever buttons 23 located at the front of the shield portion 13 . The shield portion 13 comprises a jaw shield 14 pivotally connected to the head portion 12 , pivoting about axis A, and having a pair of passages 16 through which the breath of a wearer may circulate and an eye shield 52 that has a see-through shield 18 .
With reference to FIGS. 3 and 4, the breathing mask 22 comprises a mask body 24 preferably made of a supple material so as to embrace the contours of the face. The mask body 24 preferably features a port 26 on both sides, adjacent to the mouth of the wearer. Flexible tubes 28 are provided to connect the ports 26 to the passages 16 of the jaw shield 14 (FIGS. 1 and 2 ). As can be seen in FIG. 3, the flexible tube 28 has an interior end 30 and an exterior end 32 . The interior end 30 is adapted to be engaged into port 26 and the exterior end 32 is adapted to be hermetically connected with the passage 16 . The flexible tube 28 is assembled to the mask body 24 by inserting the last rib of the interior end 30 into port 26 . The exterior end 32 is inserted through the aperture 46 of the snap-holder 36 so that the exterior end 32 protrudes through the aperture 46 of snap-holder 36 . The exterior end 32 is provided with an annular lip 31 in order to create an hermetic seal with the passage 16 of the jaw shield 14 when these two components ( 32 and 16 ) are aligned. The flexible tube 28 is also preferably made of a supple material and features an array of ribs enabling the flexible tube 28 to assume various lengths for ease of assembly and to provide freedom of movement when the breathing mask 22 is put on or taken off. The flexible tubes 28 are of course hollow to provide adequate circulation of air.
A filter 70 adapted to fit inside the breathing mask 22 is provided optionally to isolate the skin of the wearer from the mask body 24 . The filter 70 is a supple thin layer of material like a cloth or a felt, adapted to permit airflow while stopping dust particles. The material is preferably soft so as not to irritate the skin of the wearer. The filter 70 is positioned inside the mask body 24 before the breathing mask 22 is put on. It may be discarded after use and replaced by a new one or it may be re-used as often as one wishes. The filter 70 features an opening 72 , for example a V-shaped opening, which facilitates the installation of the filter 70 into the mask body 24 and prevents folding of the filter 70 when positioned over the nose of the wearer. Folding of the filter 70 could allow the breath to escape into the inside chamber 20 . Advantageously, the filter 70 protects the skin of the wearer from possible irritation when the breathing mask 22 is worn for an extended period of time. This filter 70 also serves as an hygienic device if the full face helmet 10 is to be used by more than one person.
A frontal cover 34 is mounted to the front portion of the mask body 24 in order to hold, and maintain in position, a pair of resilient straps 40 . The resilient straps 40 are engaged at each end to slender apertures 48 of the snap-holders 36 . The resilient straps 40 are provided to adjust the length of each flexible tube 28 thereby adjusting the distance between the mask body 24 and the snap-holders 36 . The adjustment is achieved by setting the length of the resilient straps 40 using standard buckles 45 . From FIG. 3, it can be seen that snap-holders 36 are elongated components featuring at one end, a substantially circular aperture 46 , a pair of slender apertures 48 and at the other end, a snap button 38 .
Referring to FIG. 5, the head portion 12 comprises a pair of side covers 80 fastened to the side of the head portion 12 featuring an aperture 82 which opens onto a snap 84 on which the snap button 38 of the snap-holder 36 will be engaged. The side covers 39 features a second aperture 86 shown in dotted lines configured to receive an optional latching mechanism 90 also shown in dotted lines which locks the jaw shield 14 to the head portion 12 when the jaw shield 14 is in the closed position. Each of the side covers 39 has a curved section 88 provided to fit the circular contour 37 of the snap-holder 36 . The combination of configuration of the circular contour 37 of the snap-holders 36 and of the curved section 88 of the side covers 39 enables proper positioning of the snap-holders 36 in relation to the head portion 12 , to the jaw shield 14 and more specifically, to the passages 16 when the jaw shield 14 is in the closed position. FIG. 7 shows how the passage 16 and the circular aperture 46 of the snap-holders 36 are aligned when the jaw shield 14 is in the closed position.
To put the full face helmet 10 on with the breathing mask 22 , the wearer must have the jaw shield 14 in the opened position. As shown in FIG. 5, the wearer first attaches one of the snap-holders 36 to the head portion 12 and then puts the head portion 12 over his or her head. The filter 70 previously described may be positioned inside the mask body 24 before the breathing mask 22 is put on. Advantageously, the filter 70 protects the skin of the wearer from possible irritation when the breathing mask 22 is worn for an extended period of time. Once the filter is positioned inside the breathing mask 22 , the wearer then puts the breathing mask 22 over his mouth and nose and engages the remaining snap-holder 36 to the other side of the head portion 12 as shown in FIG. 6 . FIG. 6 also shows the filter 70 installed thereby isolating the skin of the wearer from the mask body 24 and preventing any direct contact between the skin and the mask body 24 .
Referring to FIG. 7, once the breathing mask 22 is installed, the wearer can lower the jaw shield 14 . In the fully closed position, the optional latching mechanism 90 located on both sides of the jaw shield 14 engages the aperture 86 of the side covers 39 thereby locking the jaw shield 14 onto the head portion 12 and preventing the jaw shield 14 from unduly opening because of a wind gust or from an impact at which time, it is critical that the jaw shield 14 remains properly positioned in order to efficiently protect the wearer. The locking mechanism 90 may be disengaged by simply pressing simultaneously the two lever buttons 23 located at the front of the jaw shield 14 . The two lever buttons 23 are actuated by pressing them in the direction illustrated by the arrows in FIG. 8 . Advantageously, the lever buttons 23 are positioned close enough to each other so that they can be actuated with a single hand. This feature is very useful at times when the wearer wishes to raise the jaw shield 14 while driving a vehicle. It could be dangerous to let go of the steering even for a short period of time. This feature allows him or her to keep one hand on the steering while raising the jaw shield 14 . Moreover, once the two lever buttons 23 are pressed and the latching mechanism 90 is disengaged, the same two lever buttons 23 serve as gripping elements enabling the hand to apply the necessary force to raise the jaw shield 14 .
As shown in FIG. 7, the wearer may also choose to keep the jaw shield 14 in the closed position and instead, raise the eye shield 52 which is pivotally mounted to the jaw shield 14 . The eye shield 52 comprises the see-through shield 18 and two small handle grips 54 located at the bottom of the eye shield 52 which enable the wearer to take hold of the eye shield 52 in order to raise it. Referring to FIG. 9, the eye shield 52 advantageously features a jagged surface 55 surrounding the pivoting points which enable the eye shield 52 to be partially opened and remain in a partially opened position due to the added friction provided by the jagged surface 55 .
Referring now to FIGS. 9 and 10, the eye shield 52 also advantageously comprises an upper chamber 56 in which a tinted shield 58 is housed and adapted to be raised or lowered with a lever 60 guided by a narrow slot 62 (FIG. 8 ). The tinted shield 58 is pivotally mounted to the eye shield 52 as the dotted lines in FIG. 9 show. The tinted shield 58 is an integral part of eye shield 52 ; if the eye shield 52 is raised or lowered, the tinted shield 58 will follow the motion. The tinted shield 58 is provided to protect the eyes of the wearer from sun rays or reflexions. The tinted shield 58 , in the closed position, is hidden away inside upper chamber 56 . To lower the tinted shield 58 , the wearer simply has to grip the lever 60 and pull it downward in order for the tinted shield 58 to come over the eyes of the wearer as shown by the dash-dot-dash arrows of FIGS. 9 and 10. The tinted shield 58 comes down inside the full face helmet 10 providing an excellent protection against sun rays. The tinted shield 58 thereby allows a practical adjustment means for eyes protection against sun rays or bright reflexions. Because it is never in contact with the exterior elements, the tinted shield 58 is protected and remains almost always clean and free of scratches.
Referring back to FIGS. 1 and 2, the full face helmet 10 also includes an air entry 63 located at the front of the jaw shield 14 that can be controlled by a gate 64 to permit or restrict air flow into the inside chamber 20 of the fill face helmet 10 . Another air passage 65 is provided at the back of the full face helmet 10 also featuring a gate 66 to permit or restrict air flow into the full face helmet 10 .
The above description of preferred embodiments should not be interpreted in a limiting manner since other variations, modifications and refinements are possible within the spirit and scope of the present invention. The scope of the invention is defined in the appended claims and their equivalents.
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A breathing mask is provided for a helmet which reduces the formation of water on the lens of the eyeglasses of the wearer or on the shield of the helmet. The helmet comprises a head portion, a shield portion, and a breathing mask. The shield portion comprises a jaw shield and an eye shield. The breathing mask is hermetically adapted to the face of the wearer to evacuate the wearer's breath outside the helmet through breathing channels. The jaw shield can be pivotally opened or closed and is locked to the head portion in the closed position. The eye shield is pivotally connected to the head portion and includes a see-through shield and a tinted shield. The tinted shield can be lowered inside the helmet to protect the wearer from sun rays and reflexions.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a Continuation in Part of U.S. patent application Ser. No. 11/115,188, filed Apr. 27, 2005, which in turn claims the benefit of U.S. Provisional Application No. 60/565,532, filed on Apr. 27, 2004. The disclosures of these references are hereby incorporated by reference herein in their entirety.
BACKGROUND
[0002] The subject matter of this disclosure relates to providing building cooling, dehumidification, and fresh air ventilation through a range of outdoor and indoor conditions.
[0003] New U.S. homes that are built in compliance with ASHRAE Standard 90.2, Energy Star, and other energy efficiency programs have lower cooling loads than in the past, and because they are of tighter construction, they frequently require mechanical ventilation as prescribed by ASHRAE Standard 62.2. In humid climates, the ventilation air often requires more dehumidification than can typically be provided by air conditioners, because typical air conditioners in energy-efficient homes have short run times during many cooling load hours. Short run times typically limit latent cooling capacity, since less air passes over the cold evaporator coil. Failure to control excessive indoor humidity has contributed to problems with indoor mold. This issue has become increasingly expensive for homeowners and builders as mold-related property damage and class action lawsuits have risen steadily.
[0004] Vapor compression cooling systems (air conditioners) that are in use in most homes and other buildings provide a mix of sensible cooling (lowering the air temperature) and latent cooling (removing moisture). Typically, the sensible heat ratio (“SHR”, the sensible cooling capacity divided by the total cooling capacity) for most residential cooling systems ranges from 0.7 to 0.8. In humid conditions, this SHR is often too high to maintain temperature and relative humidity in the ideal ranges of 74°-78° F., and 40-60%, respectively. Some vapor compression cooling systems lower the airflow rate through the evaporator coil to reduce the SHR under humid conditions, but re-evaporation of condensate retained on the coil at system shutdown still limits the SHR, particularly when systems cycle frequently, as they do under low load conditions. Such residential cooling systems are “split systems”, with an outdoor condensing unit that includes the compressor, condensing coil, and condenser fan, and a separate indoor unit that includes an evaporator coil, expansion device, and system blower. Two refrigerant lines join the outdoor and indoor components.
[0005] Furthermore, a stand-alone dehumidifier is frequently used in humid climates to control indoor humidity. Because heat from the condenser is added to indoor air, the dehumidifier often increases the sensible cooling load, the air conditioner run time, and overall energy consumption. A preferred approach to dehumidification in the cooling season is to dehumidify indoor air by rejecting condenser heat to outside air instead of to the indoor space.
[0006] In the prior art, various strategies have been proposed to control both temperature and humidity. For example, U.S. Pat. No. 6,170,271 B1 shows a concept with two separate refrigerant loops: a first loop with the evaporator in the supply air stream and the condenser outdoors, for sensibly cooling the air stream; and a second “latent cooling” loop with the evaporator just downstream of the first evaporator, and with the condenser downstream of the second evaporator. This approach is similar to combining an air conditioner and a dehumidifier, but with the added benefits of requiring only one indoor blower and cabinet. A smaller second evaporator can be used because the air has been pre-cooled in the first evaporator. However, all heat from the second loop is added to the supply air, with associated energy penalties. In the embodiment, having the dehumidifier condenser located outside the supply air stream, the system is still penalized by the cost of requiring dual compressors, additional refrigerant piping, and condensers. Various other design configurations appear in the patent literature and are aimed at more precisely controlling both sensible and latent loads.
[0007] Another strategy having dual refrigerant loops is shown in U.S. Pat. No. 6,705,093 B1, which uses two condensing units that share an evaporator coil whose tubing pattern maintains separation of the two loops. One of the two loops has a sub-cooling coil. This approach adds substantial cost to a conventional system with a single refrigerant loop. Another approach to increasing latent cooling is shown in U.S. Pat. No. 6,427,454 B1. This design selectively causes a portion of the return air to bypass the evaporator coil, which lowers the coil temperature and increases moisture condensation on the coil. However, this approach is unlikely to succeed in the market, as it is comparable to lowering the blower speed, but with higher initial costs and without the energy savings associated with reducing blower speed.
[0008] U.S. Pat. No. 6,123,147 shows a retrofit system that adds a hot water reheat coil connected to a residential water heater located downstream of the evaporator. Like other “reheat” designs, this approach decreases the SHR by making the cooling system run longer. However, the economics of such a system will be poor because gas water heating is substituted for waste heat already available from the condensing side of the refrigerant system. Thus, this approach is like driving a vehicle using the accelerator and brake simultaneously. Other strategies, such as that disclosed in U.S. Pat. No. 5,791,153, apply desiccant-based enthalpy wheels to increase latent cooling. These designs require added components to recharge the desiccant and therefore may not be cost-effective.
[0009] Of the major product lines in the U.S. marketplace, only the Carrier® Infinity™ series and the Lennox™ SignatureStat™ controller claim features that control both temperature and humidity.
[0010] In the “packaged” air conditioning market with products usually applied to non-residential buildings, Lennox™ markets a patented Humiditrol® line that includes refrigerant control valves and a “hot gas” reheat coil for more precise humidity control. Carrier® markets the MoistureMiser™ that uses a “sub-cooling” coil for the same purpose. In both cases the strategy is to add some heat from the condenser side of the refrigerant system back into the supply air stream (downstream of the evaporator) to reduce the net cooling rate, as well as reducing supply air relative humidity. Such systems must run longer to satisfy the cooling load, and the longer run time removes more moisture at the evaporator. Adding more length to the coil on the condenser side also reduces the liquid refrigerant temperature into the evaporator, which increases evaporator capacity and therefore drops the evaporator temperature, increasing the rate of moisture removal. Lennox™ claims superior dehumidification performance because the higher heat output of the “hot gas” approach causes longer cooling cycles, thus removing more moisture compared to the sub-cooling approach.
[0011] These non-residential products use a “single-package” configuration, and no “split system” units currently include the “reheat coil” features described above. In fact, the Lennox™ hot gas approach is only workable in a single package device, as the system would require an extra pair of refrigerant lines to be applied in a “split system” configuration because refrigerant must flow first to the indoor reheat coil, then back to the condenser, then to the indoor expansion device. The Carrier® sub-cooling approach would not require an extra line set in a split system configuration because the refrigerant flows directly from the sub-cooling coil to the expansion device. However, the approach only provides two stages of dehumidification, and therefore cannot sufficiently control humidity when sensible loads are very low and latent loads are high.
SUMMARY
[0012] Although the vapor compression systems disclosed above, and others, use hot gas and sub-cooling reheat coils to reduce the SHR in single-package units, a system that dynamically combines features by applying multiple dehumidification stages in a split system configuration is desired. Such a system could maintain desired temperature and humidity conditions, even in the absence of cooling loads, through the full range of climatic conditions in the U.S. and elsewhere.
[0013] A desirable indoor comfort system for humid climates may use minimal added components to a conventional split air conditioning system, but may have the capability of dehumidifying even in a “neutral” condition wherein the building needs neither heating nor cooling. Using a single refrigerant loop with a supplemental reheat coil to achieve this condition may provide that the evaporator and the reheat coil have equal and opposite heat transfers to the air stream. The outdoor coil is then rejecting a heat quantity equal to the compressor input energy. A low indoor airflow rate is desirable to maximize latent cooling, taking care not to freeze the evaporator coil.
[0014] In various exemplary embodiments, the systems and methods according to this disclosure provide automatic, dynamic control of indoor relative humidity and temperature to achieve specified conditions by applying multiple stages of dehumidification. Various aspects of the exemplary embodiment include the capability to remove moisture from outside ventilation air supplied to maintain indoor air quality at times when no heating or cooling is needed. Exemplary embodiments have the ability to maintain a specified indoor relative humidity through a wide range of climates and seasonal conditions. For economic viability, such systems may be readily integrated with conventional heating and cooling components, applying the fan, coil, and condensing unit to both sensible cooling and dehumidification functions.
[0015] In various exemplary embodiments, the systems and methods according to this disclosure surpass the efficiency of air conditioners combined with stand-alone dehumidifiers by rejecting condenser heat developed in the dehumidification process to outdoors instead of indoors.
[0016] In various exemplary embodiments, the systems and methods according to this disclosure reduce energy use and startup time by regulating fan speed and properly managing refrigerant in the disclosed systems.
[0017] In various exemplary embodiments, the systems and methods according to this disclosure allow refrigerant to be evenly distributed into various circuits of the evaporator to improve efficiency.
[0018] In various exemplary embodiments, the systems and methods according to this disclosure efficiently and effectively dehumidify outside ventilation air supplied to buildings for the purpose of maintaining indoor air quality.
[0019] In various exemplary embodiments, the systems and methods according to this disclosure combine indoor cooling and dehumidification components into a single unit to facilitate installation and reduce cost.
[0020] In various exemplary embodiments, the systems and methods according to this disclosure reduce the re-evaporation of moisture into the supply air by controlling fan operation on startup and shutdown.
[0021] These and other objects and advantages of the disclosed systems and methods will be apparent in light of the following disclosure, claims and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] Various exemplary embodiments will be described, in detail, with reference to the following drawings in which like reference numerals refer to like elements and wherein:
[0023] FIG. 1 illustrates a schematic diagram of a first exemplary embodiment of refrigeration and control components according to this disclosure showing alternate refrigeration flow paths associated with various dehumidification stages;
[0024] FIG. 2 illustrates a schematic diagram of the first exemplary embodiment of refrigeration and control components according to this disclosure showing first alternate refrigeration flow paths associated with various dehumidification stages;
[0025] FIG. 3 illustrates a schematic diagram of the first exemplary embodiment of refrigeration and control components according to this disclosure showing second alternate refrigeration flow paths associated with various dehumidification stages;
[0026] FIG. 4 illustrates a schematic diagram of a second exemplary embodiment of refrigeration and control components according to this disclosure showing an alternate arrangement of components associated with various dehumidification stages;
[0027] FIG. 5 illustrates a table of configurations of solenoid valves in various dehumidification stages (operating modes) of the refrigeration and control components shown in FIG. 4 ;
[0028] FIG. 6 illustrates a schematic diagram of the second exemplary embodiment of refrigeration and control components according to this disclosure showing alternate refrigeration flow paths associated with various dehumidification stages; and
[0029] FIG. 7 illustrates a schematic diagram of the second exemplary embodiment of refrigeration and control components according to this disclosure showing alternate refrigeration flow paths associated with various dehumidification stages.
DETAILED DESCRIPTION OF EMBODIMENTS
[0030] Exemplary embodiments of the systems and methods described in this disclosure comprise sets of vapor compression cooling components that can respond to a full range of sensible and latent cooling loads, and control components with appropriate logic for automatically maintaining indoor temperature and relative humidity within close tolerances. Exemplary embodiments of the disclosed systems and methods can condition (1) re-circulated indoor air, (2) outside ventilation air supplied to buildings to maintain indoor air quality, or (3) a mixture of the two. Exemplary components of such systems may include a two-speed compressor, a condensing coil, a condenser fan, a variable speed indoor blower, an evaporator coil, a reheat coil, a refrigerant receiver, thermostatic expansion valves, solenoid valves for switching refrigerant flow, check valves, “pressure-differential check valves” (PDCV's), temperature and humidity sensors, and controls for selecting operating modes for the system based on known or sensed conditions.
[0031] FIG. 1 shows a first exemplary embodiment of an integrated dehumidification system 100 . The system comprises an outdoor condensing unit 1 , an indoor unit 40 , refrigerant lines 7 and 13 that connect the condensing unit 1 and the indoor unit 40 , and a control system 30 .
[0032] The condensing unit 1 includes a compressor 2 , condensers 3 , a cabinet 4 , and a condenser fan 5 driven by a condenser fan motor 6 . Major components of the indoor unit 40 include an evaporator coil 12 , a reheat coil 8 , a blower 21 driven by variable speed motor 22 , automatic valves 14 and 15 , and an enclosing cabinet 41 . The indoor unit also includes PDCV's and refrigerant lines as will be discussed with respect to the specific dehumidification stages below. The control system 30 includes a thermostat 33 that includes sensors for indoor temperature 31 and humidity 32 , temperature sensors for leaving air temperature 37 a and evaporator coil temperature 37 b , logic board 34 , and condenser fan relay 35 in the outdoor condensing unit 1 .
[0033] In this exemplary embodiment, the integrated dehumidification system 100 includes four dehumidification modes. A “Stage 1 dehumidification” mode has the lowest latent cooling capability and the highest SHR and may use a refrigerant flow schematic similar to that for a conventional split air conditioning system.
[0034] Stage 1 may be triggered by a call for sensible cooling by the thermostat. In stage 1, low pressure refrigerant vapor is compressed to a superheated, high pressure vapor state in the compressor 2 of the outdoor condensing unit 1 . The vapor then passes through the condenser coils 3 where the vapor condenses to a liquid state, giving up heat, before leaving the outdoor condensing unit 1 through the refrigerant line 7 . During this process, the condenser fan 5 , driven by the fan motor 6 , induces outdoor airflow across the condenser coils 3 to discharge heat to outdoor air. Although FIG. 1 shows two condenser coils 3 in parallel, other configurations, including, for example, a single “wrap-around” coil are contemplated.
[0035] After the liquid refrigerant enters the indoor unit 40 through the refrigerant line 7 , the liquid refrigerant passes through an open automatic control valve 14 . In this exemplary embodiment, there are multiple parallel paths through lines 9 , 17 , 19 , and 42 , toward the evaporator coil 12 through which the liquid refrigerant may flow. In each of these paths, however, there may be either a check valve 36 or PDCV's 16 a , 16 b . These various valves may have pressure drop settings higher than the downstream pressure drops between the entering refrigerant line 7 and an expansion device 11 . In this embodiment, after passing through the automatic control valve 14 , the refrigerant flow proceeds through the line segment 23 into the liquid receiver 10 , then through another open automatic control valve 15 via the line segment 20 , and on through the expansion device 11 . The expansion device 11 restricts refrigerant flow and causes high pressure liquid to begin a change of state from liquid to a low pressure gas. From the expansion device 11 , the refrigerant enters the evaporator coil 12 where the change of state is completed. As the refrigerant evaporates though the evaporator coil 12 , the refrigerant absorbs heat from the air stream 26 driven through the air path 18 across the evaporator coil 12 by the indoor blower 21 powered by the blower motor 22 . The heat absorbed by the refrigerant results in cooling of the air stream 26 . If the surfaces of the evaporator coil 12 are cooler than the dew point temperature of the air stream 26 , moisture will condense on the coil 12 and drip into a drain pan 27 from which it can be drained through condensate drain 28 . From the evaporator 12 , the low pressure refrigerant vapor returns through the refrigerant line 13 to the compressor 2 of the outdoor condensing unit 1 .
[0036] If the indoor temperature continues to climb, or if Stage 1 capacity is insufficient to satisfy the cooling call after a specified period of time, the compressor 2 will be switched to a higher speed with the system fan maintaining, for example, 350-400 cfm per ton until the cooling call is satisfied (temperature setpoint is reached).
[0037] If the indoor relative humidity (RH) increases to within a set differential of a user's set point (e.g. 50% minus a 2% differential, or 48%), the integrated dehumidification system 100 will shift to “Stage 2 dehumidification.” In Stage 2 dehumidification, the fan will modulate the airflow downward to increase latent cooling (moisture removal), and the speed of the fan is controlled proportional to the deviation of indoor RH from the RH setpoint. If the indoor RH exceeds the RH setpoint during this cycle, the fan will modulate to a lower airflow rate that will maintain the evaporator coil 12 between certain temperature limits, for example, a range of between 30 and 32° F., to facilitate increased moisture removal, while still providing sensible cooling. If indoor humidity later drops below the RH setpoint minus the differential, the control system 30 can return the operating speed of the blower motor 22 to the normal speed (350 to 400 cfm per ton).
[0038] FIG. 2 shows the refrigerant flow in the indoor condensing unit 40 when a “Stage 3 dehumidification” mode is in operation for the first exemplary embodiment. Stage 3 dehumidification enhances indoor air moisture removal while providing some sensible cooling. The condition of indoor air could be referred to as slightly humid, with the indoor temperature slightly below the cooling setpoint. Stage 3 is activated when the indoor RH is greater than the RH setpoint and the indoor temperature is within a set differential, for example within 2° F. of, the thermostat cooling temperature setting.
[0039] In Stage 3, warm refrigerant flowing from the condensing unit 1 adds heat to the supply air stream and sub-cools the refrigerant as it passes through the reheat coil 8 , thus lowering the sensible heating capacity while removing moisture via the evaporator coil 12 . The sub-cooled refrigerant improves the performance of the evaporator coil 12 .
[0040] In Stage 3, automatic control valve 14 may remain open, and the refrigerant flow passes through the receiver 10 , as in Stages 1 and 2. The refrigerant then flows through the line segment 42 toward the reheat coil 8 , rather than through the line segment 20 toward the evaporator coil 12 , because the automatic control valve 15 in the line segment 20 is now closed. A PDCV 16 a which may require approximately 5 psi of pressure to overcome its spring force is located between the refrigerant line 7 and the intersection of the line segments 42 and 9 to prevent the refrigerant from flowing directly into the reheat coil 8 in the first three dehumidification stages. A check valve 36 in the line segment 19 prevents bypassing of the reheat coil 8 from the line segment 23 above the receiver 10 to the line segment 17 toward the expansion device 11 . From the exit of the reheat coil 8 , all refrigerant flows through the line segment 17 and through PDCV 16 b to the expansion device 11 and the evaporator coil 12 before completing the circuit back to the compressor 2 of the outdoor condensing unit 1 through the refrigerant line 13 .
[0041] In this circuit, the liquid refrigerant from the condenser 3 (see FIG. 1 ) is sub-cooled in the reheat coil 8 . This process increases dehumidification mostly by adding heat back into the air stream 26 downstream of the evaporator coil 12 , which reduces the cooling delivery rate, causing the cooling and dehumidification system 100 to run longer to satisfy the cooling load, and reduces the supply air relative humidity. Longer operation with a constant surface temperature pattern for the evaporator coil 12 results in more moisture removal as long as part of the surface of the evaporator coil 12 is colder than the dew point temperature of the entering air stream 26 . This circuit offers an additional dehumidification benefit by sub-cooling the liquid refrigerant below the condensing temperature to lower the evaporating temperature, thus increasing the rate of moisture removal. The control system 30 (see FIG. 1 ) implements Stage 3 dehumidification by closing the automatic control valve 15 .
[0042] In Stage 3, the compressor 2 will operate at low speed and the system fan control logic can incrementally adjust the airflow to maintain the evaporator coil temperature close to a freezing point of moisture, for example, between 30 and 32° F.
[0043] A “Stage 4 dehumidification” mode operation is shown in FIG. 3 for the first embodiment. The purpose of this mode is to remove moisture from indoor air while providing little cooling or heating to the indoor air. The condition of indoor air could be referred to as slightly humid, with the indoor temperature considerably below a cooling setpoint. In this condition (cool and humid), it is undesirable to provide any sensible cooling since the indoor space will become too cool. The temperature of the air supplied to the space in this stage will be very close to the return air temperature.
[0044] Stage 4 will be activated if the indoor RH is greater than the RH setpoint and the indoor temperature is more than a set differential below the thermostat cooling temperature setting, for example more than 2° F. below the temperature setting. Supply airflow is regulated by varying the speed of the system fan in the same manner as in Stage 3, and the compressor will be operated at low speed.
[0045] In Stage 4, the automatic control valve 15 is opened and the automatic control valve 14 is closed so that the incoming refrigerant flow from the outdoor condensing unit 1 (see FIG. 1 ) is forced through the line segment 9 with a PDCV 16 a into the reheat coil 8 . The refrigerant flow then proceeds through a low pressure drop check valve 36 in line segment 19 before entering the receiver 10 . The PDCV 16 b may impose a greater pressure drop in line segment 17 than the sum of the pressure drops in the lines or segments 19 , 20 , the receiver 10 , and the open valve 15 . As a result, refrigerant flow is forced through the receiver 10 . From the receiver 10 , the refrigerant flow proceeds through the open automatic control valve 15 in the line segment 20 and through the expansion device 11 before entering the evaporator coil 12 . With the receiver 10 downstream of the reheat coil 8 , the refrigerant can partially condense in the reheat coil 8 because the refrigerant will preferentially condense in the coldest available location. Because the reheat coil 8 is in the low temperature air stream 26 leaving the evaporator coil 12 , the reheat coil 8 will typically be cooler than the condensing coil 3 (see FIG. 1 ) located outdoors. As a result, the refrigerant partially condenses in the reheat coil 8 , delivering more reheat than was available in Stage 3.
[0046] In Stage 4 the condenser fan is cycled on and off to maintain a supply air temperature that approximates the indoor air temperature and to prevent significant sensible cooling or heating of the supply air. Therefore, it is possible to operate in Stage 4 without either cooling or heating the supply air stream. This stage provides maximum latent cooling while minimizing sensible cooling of the air stream. In this “neutral” dehumidification case, sufficient condensing occurs in the reheat coil 8 to balance the cooling delivered at the evaporator coil 12 , and the heat being discharged at the condensing unit 1 equals the equivalent heat input of the compressor 2 (see FIG. 1 ). In contrast, a conventional dehumidifier adds all heat, including the compressor input heat, to the space in which it is enclosed.
[0047] System operation may switch from Stage 3 to Stage 4 as needed to prevent overcooling the space. This switching from Stage 3 to Stage 4 may be based on indoor temperature relative to a thermostat cooling setpoint. When the indoor RH falls to the RH setpoint, the system may shut off.
[0048] On startup in any of the stages, a set amount of time may be allowed to elapse before the system fan is activated. This may aid in ensuring that the evaporator coil is cold when air begins to be supplied, and holds moisture on the coil so it is not immediately re-evaporated into the supply air stream, which would cause an increase in indoor relative humidity.
[0049] FIG. 4 shows a second exemplary embodiment 200 that may provide improved refrigerant control and reduced energy use. This second exemplary embodiment uses many components described above for the first exemplary embodiment. This embodiment also supports 4 stages of dehumidification. Combinations of open and closed solenoid valves, as shown in FIG. 5 , may allow for selection of these stages. The 4 stages of the second embodiment perform similar functions to those of the first embodiment, and all of the additional controls and adaptions regarding, for example, fan speeds, compressor operation options and methods and controls for selection of a specific dehumidification stage, described for the first embodiment, may be applied to this second embodiment in any combination.
[0050] The second embodiment differs from the first embodiment in general in respect to the positioning and use of receiver 210 in the refrigerant circuits in order to improve refrigerant management and maintain proper subcooling in the various stages. In Stages 1 and 2 the refrigerant, rather than flowing through the receiver 210 , passes through open valve 214 and side port distributor 220 to reach evaporator 212 . The arrows in FIG. 4 indicate the flow of refrigerant in this embodiment for Stages 1 and 2.
[0051] Further, as can be seen, in this second embodiment the receiver 210 is not in the flow path of the refrigerant through the system, but the open valves 215 and 217 connect receiver 210 and reheat coil 208 to the low pressure side port of distributor 220 , insuring that only low pressure vapor remains in receiver 210 and reheat coil 208 , thereby retaining refrigerant in that part of the system to cause refrigerant back up and maintaining correct subcooling in condenser 203 . Distributor 220 evenly distributes refrigerant from the receiver and reheat coil into the passages of evaporator 212 .
[0052] An exemplary flow scheme for the refrigerant in Stage 3 for the second embodiment is shown in FIG. 6 . In Stage 3 of this embodiment, the open solenoid valve 216 causes refrigerant to flow from condenser coil 203 first through the reheat coil 208 . PDCV 230 has a higher pressure drop setting than PDCV 231 so the refrigerant flows through PDCV 231 , rather than PDCV 230 . From PDCV 231 , the refrigerant flows through solenoid valve 214 and the expansion valve 218 to the evaporator 212 . The closed valve 215 prevents refrigerant flow to receiver 210 . The warm liquid refrigerant flowing through reheat coil 208 adds heat to the supply air and is subcooled, increasing the capacity and moisture removal capability of evaporator coil 212 , the combined effect of which is less sensible and more latent cooling.
[0053] Further, the solenoid valve settings in the second embodiment in Stage 3 allow liquid refrigerant to discharge into the evaporator through a side port distributor 220 to maintain correct subcooling (solenoid valves 214 , 216 , 217 open, solenoid valve 215 closed). The distributor 220 attempts to ensure the refrigerant is evenly distributed into the various circuits of the evaporator 212 to improve efficiency.
[0054] An exemplary flow scheme for the refrigerant in Stage 4 for this embodiment is shown in FIG. 7 . As in Stage 3, the open solenoid valve 216 causes liquid refrigerant to flow through the reheat coil 208 . However, solenoid valve 217 is closed, isolating receiver 210 from the low pressure port of distributor 220 , and allowing high pressure liquid refrigerant that drains from reheat coil 208 to collect in receiver 210 . This high pressure liquid is forced through open solenoid valve 214 and into TXV 218 . Cold air from evaporator 212 keeps reheat coil 208 at a lower temperature than condenser 203 , attracting refrigerant vapor to preferentially condense in reheat coil 208 , adding further heat to the supply air stream. As in the first embodiment, condenser fan motor 206 is cycled in this embodiment to maintain a supply air temperature that is close to the indoor air temperature.
[0055] The second exemplary embodiment also includes features to reduce energy use and startup time. Although not specifically discussed above, these features may also be incorporated, at least in part, into the first embodiment. To reduce energy use and startup time, it is important to attempt to ensure that the refrigerant is properly controlled, allowing the system to quickly reach a state of equilibrium. For example, in the second embodiment when a cooling or humidity call is satisfied, all automatic valves ( 214 through 217 ) close and the compressor 202 continues to operate, pumping refrigerant out of the evaporator 212 . When the refrigerant pressure in the evaporator 212 falls below a specified pressure setting of a low pressure cutoff switch 240 located in the condensing unit 201 , the condensing unit 201 controls shut off the compressor 202 . On startup, in any of the stages, solenoid valve 214 opens allowing refrigerant to flow through TXV 218 and into evaporator 212 where it changes state to a gas, raising the pressure at the compressor suction line, and closing the low pressure switch 240 . This triggers the compressor 202 to operate.
[0056] With the multiple stage dehumidification strategies described here, it is possible to satisfy both temperature and humidity targets in indoor spaces through a full range of outdoor, indoor, and ventilation conditions. With control of the condensing unit fan, the system can even dehumidify in the absence of cooling loads or can deliver heat while dehumidifying, if desired. In each stage of the dehumidification operation, the system can operate at maximum potential efficiency by rejecting the most heat possible to the outdoor environment while satisfying the indoor temperature and humidity targets. For example, Stage 4 provides an SHR of approximately 0-10%; Stage 3 provides an SHR of approximately 40-60%; Stage 2 provides an SHR of approximately 60-70%; and Stage 1 provides an SHR of approximately 70-90%.
[0057] Although the systems and methods according to this disclosure have been shown and described with respect to preferred embodiments, it should be understood that various changes and omissions in the form and detail of components, processes, and structural inter-relationships may be made without departing from the spirit and scope of the disclosure. For example, the system has been described assuming an air-cooled condenser. However, the multi-stage dehumidification strategies described may be applied with water-cooled condensers or storage-type condensers such as hydronic or direct refrigerant ground-loops.
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A dynamic system controls indoor relative humidity and temperature to achieve specified conditions by applying multiple stages of dehumidification. In addition to a stage that increases dehumidification by reducing the speed of the indoor blower, the system uses a reheat coil and multiple valves that allow the reheat coil to function as either a subcooling coil or a partial condenser. Thus the system can maintain specified indoor temperature and humidity conditions even at times when no heating or cooling is needed. The system may have an outdoor condensing unit including a compressor and a condenser operably connected via refrigerant lines to an indoor unit to form a “split system” refrigerant loop.
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This is a continuation-in-part of application Ser. No. 08/079,874, filed Jun. 23, 1993, and now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to closure fasteners and more particularly, to a slidably removable hasp and staple wherein both the hasp and the clasp can be completely removed from the closure fastener when the fastener is in an open condition.
2. Description of the Prior Art
Closure fasteners are known in numerous forms, one of the most common being a hasp and a cooperating staple. For example, U.S. Pat. No. 702,605, issued Jun. 17, 1902 to August Voight, and U.S. Pat. No. 2,046,078, issued Jun. 30, 1936 to William H. Marshall, each show a conventional hasp and matingly engageable staple fixedly attachable to a door and threshold, respectively. A problem associated with the hasp and staple is as follows: when not in use, the hasp moves freely to extend transversely from its respective mounting surface and the staple extends rigidly from its respective mounting surface, both of which present potential harm to persons in the proximity of the same.
A combination hasp and staple which are readily removable from their respective mounting surfaces could reduce the risk of harm which may otherwise be present in the vicinity of a hasp and staple in an uncoupled condition. Applicant proposes a hasp and staple which slidably engage fixed mounts such that the two are captively retained when they are coupled to support a lock and which slidably disengage so as to be stored when uncoupled. U.S. Pat. No. 513,667, issued Jan. 30, 1894 to John L. Buckingham, discloses a sliding staple for hasps comprising a housing or a support provided with a longitudinal slot through which the staple is designed to project and slide freely. The staple is carried by a plate which is of sufficient width to extend under the upper or outer wall of the support to restrict its displacement along a longitudinal axis. U.S. Pat. No. 513,668, issued Jan. 30, 1894, also to John L. Buckingham, discloses a hasp having a first portion provided with holes for receiving screws. Opposite sides of the first portion are provided with flanges for cooperatively receiving a second portion. A pin protrudes from the first portion which engages and moves freely in a first slot in the second portion. A second slot is provided for the reception of the staple. Unlike applicant's instant invention, to be described hereinafter, the aforementioned staple and hasp disclosed by Buckingham are displaceable to compensate for the expansion and contraction of the structure in which the same are applied. Neither the staple nor the hasp may be readily removed.
A closure fastener of the hasp and staple type, wherein the hasp can be readily removed, are shown in U.S. Pat. No. 3,317,230, issued May 2, 1967 to Raymond R. Demrick et al., U.S. Pat. No. 3,927,544, issued Dec. 23, 1975 to Jack Klein, and Netherlands Pat. No. 65,151, issued Feb. 15, 1950 to Eras.
A closure fastener of the hasp and staple type wherein the staple can be readily removed is shown in U.S. Pat. No. 1,473,080, issued Nov. 6, 1923 to Calhoun Collins.
Alternative forms of a hasp and staple are shown in U.S. Pat. No. 4,403,799, issued Sep. 13, 1983 to Robert S. Kafka et al., and U.S. Pat. No. 4,316,626, issued Feb. 23, 1982 also to Robert S. Kafka et al., each of which disclose a flush mount hasp rigidly attached to a door. The hasp extends beyond the door edge to cooperatively engage a foldable, upstanding staple. The staple is rigidly attached to the door jam adjacent to the door. Because the hasp is rigidly attached to the latch so as to extend beyond the edge thereof, it is inclined to subject individuals to potential injury, especially when the door is not in a closed position. The rigid attachment of the hasp to the door clearly appears to present a greater risk of injury when the hasp and the staple are uncoupled and the door is in an opened position.
Another form of clasp and hasp fastener is shown in U. S. Pat. No. 3,796,071, issued Mar. 12, 1974 to Alois Crepinsek, showing a clasp 33 slidably cooperating with a hasp 30 and covering same when closed. The Crepinsek clasp, as shown in FIGS. 9 and 10, has smoothly rounded edges to minimize injuries.
Fasteners of the hasp and staple type formed from sheet metal are shown in U.S. Pat. No. 1,623,050, issued Apr. 5, 1927 to Peter Frantz, U.S. Pat. No. 1,805,401, issued May 12, 1931 to Edward K. Janney, and U.S. Pat. No. 2,790,664, issued Apr. 30, 1957 to Benjamin E. Bramley et al.
Hasp and staple type fasteners having pivotally mounted sheet metal hasps are shown in U.S. Pat. 722,344, issued Mar. 10, 1903 to Reuben D. Wirt, U.S. Pat. No. 1,222,649, issued Apr. 17, 1917 to Ianthus E. Marshall, U.S. Pat. No. 1,734,655, issued Nov. 5, 1929 to Eugene C. Turner, and U.S. Pat. No. 1,988,185, issued Jan. 15, 1935 to Henry M. Borden.
Further known fasteners of the hasp and staple type having sheet metal locking springs as shown in U.S. Pat. No. 878,047, issued Feb. 4, 1908 to George F. Darracott, U.S. Pat. No. 1,842,385, issued Jan. 26, 1932 to Otto A. Boesel, British Pat. No. 279,611, issued Nov. 3, 1927 to Skeldings et al., and on page 152 of a Popular Mechanics Publication, published August, 1956, in an article titled, "Self Locking of Hasp Prevented".
Applicant's instant invention would be ideal for use in areas involving tight quarters, such as in trailers and in boats, and would truly be advantageous for use on structures positioned at eye level, such as cabinets and the like. None of the above patents, taken either singly or in combination, is seen to describe the instant invention as claimed.
SUMMARY OF THE INVENTION
The present invention is a closure fastener comprising a hasp assembly and a cooperating staple assembly. The closure fastener may be formed from plastic, metal, metal alloy or a combination thereof. All of the parts of the closure fastener can be stamped, forged or cast from suitable material. Stainless steel is preferred since it is tough, presents a pleasing appearance, and resists chemical attack. However, carbon steel which has a protective coating of rust preventing material such as thermoplastic, rubber, enamel, or an electroplated nobel metal (i.e. silver, gold, and platinum) can be employed. A suitable alloy is bronze (i.e. an alloy of copper and tin). Also suitable plastic which can be molded, extruded, or cast in suitable form can be employed. Polyethylene and polypropylene are preferred materials which can be easily extruded. Polycarbonate plastic is a preferred molded plastic material. Metal and plastic components made from sintered powder technology can also be employed. Austenitic steel noted for extreme hardness can further be employed. The material employed is of suitable thickness to resist breaking under normal use. The hasp assembly includes a hasp which slidably engages a hasp mount via a tongue pivotally attached to the hasp. The staple assembly includes a staple rigidly attached to a base which slidably engages a staple mount. Upon coupling the hasp and the staple, and applying a lock to the staple, the tongue and the base are captively retained such that the two are prevented from being removed from their respective mounts until the lock is removed, and the hasp and staple are uncoupled. The same mount may be used for the staple and the hasp. This mount is formed from a single piece of sheet metal suitably bent into a channel-like shape. The hasp mount and the staple mount are rigidly secured to adjacent portions of a door and a door frame. The mounts may be of closed box-like configuration to present smooth edges to prevent any inadvertent snagging of the edges thereof by a person when installing the mounts or when passing by the installed mounts. As an alternative, the tongue and the base may be provided with a hook and their respective mounts may each include a biasing mechanism to bias the hooks into engagement therewith. In this embodiment, the tongue and the base each must be intentionally released regardless of whether the hasp and staple are coupled. As a further alternative, the staple may be formed from a single U-shaped piece of sheet metal which has been suitably bent upon itself to form an integral staple with a pair of tabs joined back to back, the tabs being apertured to receive a shank of a padlock therethrough. The staple also has a front base from which the tabs extend and which is integrally joined to a back base by a curved bight portion. The bases are of unequal lengths. The back base is longer than the front base. The back base is adapted to slidably engage within a mount to releasably fasten the staple thereto. The curved bight portion of the staple prevents the staple from being removed from the mount when a padlock is in place within the apertures in the tabs to lock the staple and an associated hasp of the fastener together. Yet another embodiment of the staple is formed from a piece of stiff wire which has been bent into a U-shape having a bight portion for engagement with an associated pivoted hasp and shank of a padlock. The wire staple has a pair of free ends which are fixedly secured to an associated J-shaped base having a bight portion and parallel leg portions of unequal lengths. Metallic welding, brazing, and soldering can be employed to fixedly secure the free ends of a metallic wire staple to a metallic base. Ultra sonic welding can be employed to fixedly secure the staple and the base together when the wire staple and base are formed of plastic.
Accordingly, it is a principal object to provide a closure fastener comprising a hasp and staple which are readily removable from their respective mounting surfaces.
It is another object that the hasp and staple slidably engage respective mounts during attachment to and detachment therefrom.
It is a further object that the hasp have a tongue pivotally attached thereto and the staple have a base attached thereto, wherein the tongue and the base slidably engage their respective mounts.
Still another object is that upon coupling the hasp and the staple and applying a lock to the staple, the hasp and the staple are captively retained such that the two are prevented from being removed from their respective mounts.
Yet another object is to provide a closure fastener in which the hasp and the base each include a hook, and their respective mounts each include a biasing mechanism to bias the hooks into engagement with their respective mounts, whereupon the hasp and the staple must each be intentionally released from their mounts regardless as to whether the hasp and staple are coupled together.
Another object of the invention is to provide a universal mount which can be employed to mount both a staple and a hasp of a closure fastener in a slidable readily releasable manner.
Still another object of the invention is to provide a channel-like universal mount for a hasp and a staple of a closure fastener which is formed from bent sheet metal.
Yet another object of the invention is to provide a universal mount for a closure fastener which, when mounted, has smooth external edges to prevent snagging of an article thereon.
Another object of the invention is to provide a universal mount for a fastener which is formed from a zigzag piece of flexible sheet metal having an elongated base with opposed tabs extending from opposite sides thereof in a staggered manner so that one tab forms a lower back portion of the mount and the other tab forms an upper back portion of the mount. The tabs are apertured to receive fasteners therethrough and have sufficient flexibility so that the mount can be fastened on an uneven surface.
A further object of the invention is to provide a hasp which has a pivotally mounted tongue which slidably engages within a universal mount to removably retain the hasp in a desired position.
Yet another object of the invention is to provide a hasp wherein the hasp has a tongue which is of greater length than an associated mount so that the hasp cannot be removed from the associated mount when securely fastened to an associated staple.
A further object of the invention is to provide a staple of a closure fastener wherein the staple is integrally formed from a U-shaped sheet of bendable sheet metal.
Still another object of the invention is to provide a staple of a closure fastener wherein the staple has a pair of tabs integrally joined in back to back relation and each tab is provided with opposed aligned apertures of sufficient size to receive a shackle of a padlock therethrough.
Another object of the invention is to provide a staple of a closure fastener wherein the staple has an apertured tab projecting from a front base portion which is integrally joined to a rear base portion in a hook-like manner.
Yet another object of the invention is to provide a staple of a closure fastener wherein the staple has a base which slidably engages within an associated mount and has greater length than the mount so that the staple cannot be removed from the mount when it is locked within an associated hasp by a padlock.
Still another object of the invention is to provide a staple of a closure fastener wherein the staple has a pair of bases of unequal lengths joined by a smoothly curved bight portion.
Another object of the invention is to provide a staple of a closure fastener wherein the staple has a base portion which has a pair of spaced flexible tabs which slidably and frictionally engage edge portions of an associated mount so that the staple can be retained at a desired position relative to the associated mount.
Yet another object of the invention is to provide a universal mount for a closure fastener wherein the mount has a base which is provided with openings therein to accommodate fasteners to securely fasten the mount to an associated surface of a door and door jamb of a cabinet, such as a school locker.
Another object of the invention is to provide a closure fastener fabricated from bendable stainless steel.
A further object of the invention is to provide a closure fastener fabricated from plastic material.
Yet a still further object of the invention is to provide a closure fastener fabricated from parts which can all be stamped, forged or cast.
Another object of the invention is to provide a closure fastener fabricated from parts which can all be stamped, forged or cast from metallic material.
A still further object of the invention is to provide a closure fastener fabricated in part from plastic material and in part from metallic material.
Still another object of the invention is to provide a mount for a closure fastener wherein the mount has a plurality of openings therein on opposite faces thereof, one set of openings being of sufficient size to receive a shank of a screwdriver therein, and the other set of openings being of sufficient size to snugly receive mounting screws therethrough.
A further object of the invention is to provide a mount for a closure fastener wherein the mount has openings therein to accommodate screw fasteners having convex heads, the openings being concave so that screw heads will fit flush.
It is an object of the invention to provide improved elements and arrangements thereof in an apparatus for the purposes described which is inexpensive, dependable, and fully effective in accomplishing its intended purposes.
These and other objects of the present invention will become readily apparent upon further review of the following specification and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded perspective view of a hasp and cooperating staple according to a first mode of the present invention.
FIG. 2 is a perspective view of the hasp and staple shown in FIG. 1.
FIG. 3 is an environmental perspective view of the hasp and staple shown in FIG. 2.
FIG. 4 is an exploded perspective view of an alternative hasp and cooperating staple according to a second mode of the present invention.
FIG. 5 is a side elevational view of the hasp and staple shown in FIG. 4.
FIG. 6 is an exploded perspective view of a hasp and cooperating staple according to a third mode of the present invention.
FIG. 7 is a perspective view of the hasp and staple shown in FIG. 6 in open condition.
FIG. 8 is a perspective view of the hasp and staple shown in FIG. 6 in a closed condition.
FIG. 9A is a front view of a universal mount for both the hasp and the staple.
FIG. 9B is a top view of the universal mount of FIG. 9A.
FIG. 9C is a back view of the universal mount of FIG. 9B showing the tabs which are bent to form the back of the mount.
FIG. 9D s a top plan view of the blank from which the universal mount of FIG. 9B is formed.
FIG. 9E is a perspective view of the universal mount formed from the blank of FIG. 9D.
FIG. 10A ms a rear view of a staple of the invention.
FIG. 10B a left side elevational view of the staple of FIG. 10A.
FIG. 10C is a perspective view of the staple.
FIG. 10D is a top plan view of the blank from which the staple of FIG. 10C is formed.
FIG. 11A is a perspective view of a piece of wire used to form a hoop of a staple.
FIG. 11B is a perspective view of the wire of FIG. 11A when formed into a hoop of a staple.
FIG. 12 is a perspective view of the wire hoop of FIG. 11A attached to a flat base to form a staple.
FIG. 13 is a perspective view of a wire hoop of FIG. 11A attached to a J-shaped base to form a staple.
Similar reference characters denote corresponding features consistently throughout the attached drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The first embodiment of the present invention, as shown in FIGS. 1 through 3, is a closure fastener 10 preferably fabricated substantially of plastic, metal or a metal alloy. A suitable metal for forming the closure fastener is stainless steel. The fastener 10 comprises a hasp assembly 12 and a cooperating staple assembly 14. The hasp assembly 12 includes a hasp 16, a tongue 18 pivotally attached to a pivotal end of the hasp 16, and a hasp mount 20 for releasably receiving the tongue 18. The staple assembly 14 includes a staple 22, a base 24 rigidly attached to staple 22, and a staple mount 26 for releasably receiving the base 24.
The hasp 16 is a substantially rectangular planar member having a slot 28 longitudinally disposed in a locking end thereof, the locking end being located opposite the pivotal end. The slot 28 facilitates in receiving the staple 22 therethrough when the hasp and staple assemblies 12, 14 are cooperatively engaging one another. The dimensions of the hasp 16 are dependent on the structure (shown in FIG. 3) to which it is attached.
The tongue 18 is a substantially rectangular planar member. The dimensions of the tongue 18 are such that the tongue 18 slidably engages the hasp mount 20. The tongue 18 is pivotally attached to the pivotal end of the hasp 16 via a hinge linkage 30. The hinge linkage 30 is offset to permit the hasp 16 to close flush against the hasp mount 20 upon engagement of the hasp and staple assemblies 12, 14.
The hasp mount 20 is comprised of a planar panel having inwardly directed folds 32 along the opposing longitudinal sides thereof. Oppositely disposed channels 34 are bounded by the folds 32. The channels 34 cooperatively receive the longitudinal sides 36 of the tongue 18. The hasp mount 20 further includes a plurality of bores 38, shown more clearly in FIGS. 4 and 5, the bores 38 preferably being countersunk. Each bore 38 accommodates a threadable fastener 52, as shown in FIG. 5, for rigidly attaching the hasp mount 20 to a supporting surface D (shown in FIG. 3). Bores 40 are also provided in the top or the exposed surface of the hasp mount 20 which provide access to the bores 38 in the bottom of the hasp mount 20 to permit the fasteners 52 to be applied through the bores 38 in the bottom of the hasp mount 20.
The staple 22 is shown as a substantially U-shaped member attached integrally to the base 24. It should be understood that a substantially square piece of stock having an aperture therein may be employed in the place of the U-shaped member. The staple 22 may be forged from metallic material or stamped or cast from plastic or metallic material. The staple 22 includes an aperture 42 passing therethrough providing a passage for a shackle of a lock L, as shown in FIG. 3.
Similar to the hasp mount 20, the staple mount 26 is comprised of a planar panel having inwardly directed folds 44 along the opposing longitudinal sides thereof. Oppositely disposed channels 46 are bounded by the folds 44. The channels 46 cooperatively receive the longitudinal sides 48 of the base 24. The staple mount 26 also includes a plurality of bores 50 for accommodating threadable fasteners 52 (shown in FIG. 5) for rigidly attaching the staple mount 26 to its respective supporting surface J (shown in FIG. 3). An opening 41 is provided in the top or the exposed surface of the staple mount 26 which provides access to the bores 50 in the bottom of the staple mount 26 to permit the fasteners 52 to be applied through the bores 50.
As shown in FIGS. 1 and 2, the tongue 18 slidably engages the hasp mount 20 and the base 24 slidably engages the staple mount 26. The staple mount 26 includes a laterally extending member 8 which facilitates in limiting the travel of the base 24 of the staple assembly 14 therethrough.
In use, as is shown in FIG. 3, the hasp mount 20 is mounted to a movable portion D, such as a door of a structure to which it is secured, and the staple mount 26 is mounted to a stationary portion J, such as a door jam of the structure to which it is secured, or vice versa. The tongue 18 of the hasp assembly 12 is slidably inserted into the hasp mount 20 and the base 24 of the staple assembly 14 is slidably inserted into the staple mount 26. The hasp 16 is pivotally displacable to permit the staple 22 to be received by the slot 28. The shackle S of a lock L is passed through the aperture 42 in the staple 22 to maintain the same in engagement with the hasp 16. With the lock L applied, the tongue 18 and the base 24 are captively retained, that is to say, prevented from being removed from their respective mounts 20, 26, and the fasteners 52, as shown in FIG. 5, are inaccessible.
Alternative embodiments of the closure fasteners 60, 90 are shown in FIGS. 4 and 5. The hasp assembly 62 of one of the alternative closure fasteners 60, as shown in particular in FIG. 4, includes a tongue 64 having a hook 66 which engages the terminal end of the hasp mount 68. The hook 66 is formed integrally with the tongue 64 by bending the lateral edge of the leading end of the tongue 64 so as to permit the inside corner of the bend to engage the terminal end of the hasp mount 68. The hasp mount 68 includes a piece of spring material 70 formed from plastic or metal which applies a biasing force against the tongue 64. Upon engaging the tongue 64 with the hasp mount 68, the hook 66 is biased against the interior wall of the passage through the hasp mount 68. At the juncture where the hook 66 exits the passage through the terminal end of the hasp mount 68, the tongue 64 is biased such that the hook 66 engages the terminal end of the hasp mount 68. The hook 66 retains the tongue 64 in engagement with the hasp mount 68 until the tongue 64 is intentionally released. The tongue 64 may be released simply by applying a force against the tongue 64 in opposition to the force of the spring material 70 which, in turn, displaces the hook 66 out of engagement with the terminal end of the hasp mount 68, enabling the tongue 64 to be slidably released from the hasp mount 68.
Similar to the hasp assembly 62, the staple assembly 80 includes a base 82 having a hook 84 which engages the terminal end of the staple mount 86. The staple mount 86 includes a piece of spring material 88 formed from plastic or metal which applies a biasing force against the hook 84 to engage the hook 84 with the terminal end of the staple mount 86. The base 82 may be released by applying a force against the base 82 in opposition to the biasing force of the piece of spring material 88, in turn, displacing the hook 84 and enabling the base 82 to be released from the staple mount 86.
The staple mount 86 further includes a stop 54 extending beyond its terminal end for limiting the travel of the base 82 relative to the staple mount 86. The stop 54 is formed from a cantilevered portion of the planar panel which forms the staple mount 86. The cantilevered portion is bent so as to extend parallel to and a predetermined distance from the opening 56 at the terminal end of the staple mount 86. The travel of the base 82 relative to the staple mount 86 is limited through the contact of the leading end of the base 82 with the stop 54. The hasp mount 92 of the other alternative closure fastener 90, as shown in FIG. 5, may also be provided with a similar stop 94 extending beyond its terminal end for limiting the travel of the tongue 64 relative to the hasp mount 92.
Additional alternative embodiments of the closure fasteners 60,90 are shown in FIGS. 6 to 10. The hasp assembly 98 shown in FIGS. 6 to 8 includes a tongue 18 pivotally secured to front plate 16. The pivot connection is shown at 30 and includes a non-removable pintle pin and associated pintles integrally formed on the tongue 18 and associated plate 16. The tongue 18 is formed of greater length than an associated hasp mount 200 so that the hasp cannot be removed from the hasp mount when the closure fastener is fastened by a conventional padlock of the type shown at L in FIG.3. Tongue 16 has an elongated slot 28 therein for reception of prong 103 of an associated staple and has a rounded edge 29 as shown in FIGS. 6 and 7, to facilitate gripping thereof by the fingers of a user.
The staple assembly 100 shown in FIGS. 6 to 8 and 10A-D is formed from a sheet metal blank of stainless steel (FIG. 10D) and includes a prong 103 with an opening 102 therein of sufficient size to receive a shackle of a padlock. As shown in FIG. 10D the sheet metal blank is generally U-shaped and has a central bend portion 109 which when bent outwardly from the plane of the blank at the lateral bend portions 111 and 113 forms a tongue 103 engageable within slot 28, as shown in FIG. 8. The staple 100 has bend portions 107 and 112, as shown in FIG. 10D, which when bent into the plane of the blank form a pair of tabs 106 and 110 which underlie portions 104 and 108 of the staple. Tabs 106 and 110 are of a greater length than associated portions 104 and 108 of mount 200 (FIGS. 6 and 7) to prevent the staple 100 from being removed from an associated mount 200 when the staple 100 is secured in a fastened condition by an associated padlock. Tabs 106 and 110 are spaced slightly from each other, and the outside edges of these tabs slidably and frictionally bear against opposed inside surfaces of the channel formed by edges 202 and 204 of associated mount 200. All bends are arcuately made so as to have smooth external surfaces to prevent injury to a person installing the closure fastener.
The mount 200 for the staple 100 and clasp 98 is formed from a bendable sheet metal blank as shown in FIG. 9D. Dotted lines 210 and 212 indicate where the blank is bent to form an open channel with side walls 202 and 204. The blank is of generally zigzag configuration with a front portion having openings 400 therein and opposed staggered tabs 206 and 208 which when bent into the plane of the blank form the back of the mount 200. The opposed staggered positions of tabs 206 and 208 wherein these tabs 206 and 208 extend integrally from opposite edges 204 and 202 of the mount 200, as clearly shown in FIGS. 9C and 9D, precludes a thief from using a tool (such as a screw driver or crow bar) to peel back edges 202 of mounts 200 and ripping a fastened closure fastener off a surface of a structure to which it is attached to pilfer the contents therein. Openings 400 are of sufficient size so as to readily accommodate the shank of a screw driver (not shown) so that a screw driver can readily be employed to drive fastening screws (not shown) extending through openings 401 and 402 formed in tabs 206 and 208. The surface of the openings 401 and 402 associated with a fastening screw are concave to accommodate a convex head formed on the screw so that the fastening screw heads will be flush with tabs 206 and 208. Scoring of the sheet metal blanks can be used to indicate the locations where the blanks are bent and the apertures are punched out and to facilitate bending and punching of the sheet metal in such a manner as to leave smooth surfaces on the exterior thereof.
An alternative method of forming the staple hoop is shown in FIGS. 11A and 11B. A length of straight wire 300 of suitable stiffness is bent at its midpoint to form a hoop 302 of a staple to form an open bight with generally parallel legs which terminate in free ends 304 and 306. Wire 300 can be of bendable plastic or metal, Suitable materials are polypropylene, copper, and steel. A protective rubber coating (not shown) can be applied over the wire 300 to prevent chemical reaction such as oxidation (i.e. rusting) of a metal wire. The rubber coating when applied will also provide a soft, smooth surface to prevent injury to a person handling the staple and prevent a metallic staple from making a clinking sound when carried with coins in a pocket of a user.
Additional alternative embodiments of the staple for the closure fastener are shown in FIGS. 12 and 13. Wire hoop 302 is fixedly attached at free ends 304 and 306 to a suitable base 308 in FIG. 12 and 312 in FIG. 13 to form a closed hoop for reception of a hasp thereover and a padlock therethrough as shown in FIG. 3. Adhesive, brazing, electric heat welding, and ultrasonic welding (not shown) can be employed to rigidly secure the ends 304 and 306 of the hoop 302 to an associated base.
Base 308 of the staple shown in FIG. 12 has a stop 310 secured thereto to prevent removal of loop 302 from an associated base 26 in FIG. 1, 86 in FIG. 4, and 200 in FIG. 6 when the staple is secured in a fastened condition by an associated padlock L. Stop 310 is formed from a strip of material of the same thickness as base 308 which has been fixedly secured to an edge of the base 308 by suitable adhesive or welding (not shown). Base 308 can have a slippery surface such as wax or high gloss paint thereon (not shown) to facilitate removal from said staple from an associated staple mount when the closure fastener is in an unlocked condition. Base 308 can have a friction surface thereon such as ribbed rubber or sandpaper (not shown) to retain the staple in a desired position relative to an associated staple mount to facilitate use thereof by a handicapped person such as a one armed user.
Base 312 of the staple shown in FIG. 13 is joined to a parallel positioned base 313 of greater length than base 312 by a bend which forms a stop 314 to prevent removal of loop 302 of the staple base 313 from an associated staple mount when the closure fastener is in a closed locked condition. Base 313 has a surface which can have a smooth or a rough surface thereon for suitable engagement with an associated staple mount as described above in conjunction with the base 308 of the staple shown in FIG. 12.
It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims.
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A closure fastener comprising a hasp and a cooperating staple. The hasp is slidably engageable with a mount and the staple is slidably engageable with another mount. Upon coupling the hasp and the staple and applying a lock thereto, the hasp and the staple are captively retained such that the two are prevented from disengaging from their respective mounts. Alternatively, the hasp and the staple are provided with a hook and the mounts each include a biasing mechanism to bias the hooks into engagement with their respective mounts. In this arrangement, the hasp and the staple must each be intentionally released from their respective mounts. In each embodiment, a stop mechanism is provided to limit the travel of tongue and the base through their respective mounts. The hasp and staple can be formed made from sheet metal blanks. The mount for the staple and hasp can be formed as a universal mount from a zigzag shaped sheet metal blank. The staple can be formed from a U-shaped sheet metal blank. All the parts of the closure fastener can be stamped or cast from plastic or metal or forged from metallic material.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a pipe coupling apparatus which is useful for making connection to a pipe or which, when used in pairs, can be used to join two pieces of pipe or the like. More particularly, this invention relates to a pipe coupling apparatus which is particularly useful for making underwater pipe connections and which can be operated remotely by the use of hydraulic fluids.
2. Description of the Prior Art
Most prior art pipe coupling devices either had hydraulically actuated seal means for effecting a seal between a coupling and a pipe without any gripping means or had gripping means for effecting locking of the coupling with the pipe without any seal means. Subsequent to that, there developed a type of pipe coupling which was hydraulically actuated which combined both seal means and gripping means which were hydraulically actuated, but which actuation was by the same system. The following U.S. patents are generally illustrative of this type of apparatus, and they include U.S. Pat. Nos. 3,393,926, 3,704,033 and 3,830,526. Couplings of the type taught in these patents have been very useful in certain installations and have been considered superior to certain prior art couplings. However, they are not suitable in all installations and all working conditions, and there developed a need for an improved underwater hydraulically actuated pipe coupling in which the seal means could be separately actuated from the gripping means and wherein the two could be separately actuated and operated to accommodate variations in size, pipeline pressures and external environmental conditions.
SUMMARY OF THE INVENTION
It is, therefore, an object of this invention to provide an improved pipe coupling device which is particularly adaptable for use underwater and which overcomes certain of the prior art problems discussed above.
By way of summary, this invention is for a pipe coupling having a housing arranged for mounting over the external surface of a pipe to which connection is to be made. The housing has deformable resilient annular seals mounted in the housing for sealing between the housing and the pipe upon actuation thereof. Thrust means in the form of a thrust sleeve or the like are included for applying axial force to the seal means to thereby deform the seal means to the sealing position. Actuation means are operably connected between the thrust means and the housing for urging the thrust means axially whereby the thrust means deforms the seal means to the sealing position. The apparatus also includes means operably associated with the housing and the thrust means for retaining the seal means in the actuated or sealing position.
The invention further includes within the housing a pair of spaced apart tapered and axially facing annular bowl surfaces on the internal surface thereof with the bowl surfaces being axially spaced apart from the aforesaid seal means. A plurality of circumferentially spaced apart wedge shaped gripping slips are supported in the housing in camming relationship with each of the bowl surfaces and arranged for gripping contact with the bowl and camming axially along the adjacent bowl surface. Annular spring means are mounted adjacent the blunt ends of the slips in each of the plurality of slips for applying a biasing force to the slips to thereby urge and cam the slips to the gripping position and to continuously urge said slips into gripping contact with the pipe. Means are included for applying hydraulically actuated force to the spring means to thereby axially compress the spring means and to thereby urge the slips to the gripping position.
The actuation means for actuating the thrust means includes a plurality of hydraulic cylinder and piston assemblies detachably connected to the housing and thrust means whereby the same may be removed after installation of the pipe coupling and reused. One form of thrust means is an annular sleeve having one axial end arranged to abutt against the end of the seal means to effect deformation thereof. The retaining means preferably takes the form of wedging or locking means carried by the sleeve and arranged for engaging the internal surface of the housing upon actuation to thereby lock the sleeve in the fixed position and, hence, lock the seals in a sealing position.
Preferably, the spring means are in the form of a rubber or other elastomeric ring which can store energy when subjected to axial compression. The means for applying hydraulic actuated forces to the spring means preferably includes the plurality of circumferentially spaced apart cylinders provided in the housing with each of the cylinders having two pistons mounted for axial movement therein and means for applying pressurized fluid to the cylinders to urge the pistons axially apart to effect or apply an axial force to the spring means discussed above.
Reference to the drawings will further explain the invention wherein:
FIG. 1 is a partial longitudinal central sectional view of one preferred embodiment of the invention showing the various elements in the unactuated positions.
FIG. 2 is a view similar to FIG. 1 but showing the gripping and seal means actuated into engagement with the pipe to which connection is to be made.
FIG. 3 is a perspective view of the coupling shown in FIGS. 1 and 2 and showing the setting clamp for actuating the seal means.
FIG. 4 is a cross-sectional view taken generally along Line 4--4 of FIG. 2.
FIG. 5 is a fragmentary and enlarged view of the locking means for locking the seals in the sealed position.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, the numeral 11 generally designates the coupling housing and the numeral 12 generally designates the pipe to which a connection is to be made. The right end of housing 11 as shown in FIGS. 1 and 2, is generally shown as being attached by welding or the like to an attaching sub 13 which, in turn, may be connected to a conventional flange or a tilted flange which, in turn, may be connected to a similar coupling device arranged for connecting to an adjacent piece of pipe. Alternatively, sub 13 may be connected to other innerconnecting means such as a member of a ball and socket coupling or the like. In making an underwater connection between two axially spaced apart pipe ends, it would be contemplated that each of the pipes to be connected would have mounted thereon a coupling of the type shown in FIGS. 1 and 2, with the couplings then being innerconnected by attaching means connected by welding or the like to the respective attaching subs 13. Hence, the usual installation for innerconnecting two pipes would be by the use of two couplings of the type as shown in FIGS. 1 and 2. However, for purposes of this application only, one of the couplings will be explained and described herein.
Housing 11 includes a portion identified as compression bowl 14 which has an inner annular axially tapered compression bowl surface 15 which forms a camming surface for gripping means to be described hereinafter. Housing 11 also includes a portion identified as tension bowl 20 which has on the inner diameter thereof an annular axially tapered tension bowl surface 21 which may be described as generally facing compression bowl surface 15 and arranged for camming engagement with additional gripping means which will be described hereinafter. Housing 11 also includes another portion which may be described as sealing sub 24 which carries sealing means in the form of a plurality of rubber or other elastomeric packing rings 25 having interposed therebetween a metal test ring 26 having a channel 27 about the exterior thereof which communicates with a plurality of radially extending ports 28 extending therethrough. Communication to channel 27 and ports 28 is via conduits 29 formed in the body of sub 24, which connects with plug 30, as shown. The tool may be provided with one or more such conduits 29 and plugs 30 spaced circumferentially about the housing 11, whereby fluids may be injected thereinto from a plurality of locations and through which evacuation of fluids from the setting system may be effected when that is desired.
The right furthermost packing ring 25, as shown in FIGS. 1 and 2, is arranged to abutt against annular shoulder 34 which is formed by an annular radially inwardly extending portion of sub 24 as shown in FIGS. 1 and 2. The leftmost one of the packing rings 25, as shown in FIGS. 1 and 2, is arranged for axial abuttment thereagainst by cylindrical locking sleeve 37. The opposite end of sleeve 37 has attached thereto an annularly enlarged portion forming packing flange 38. Hence, upon axial movement of sleeve 37 to the right, as shown in FIGS. 1 and 2, relative to housing 11, packing rings 25 are axially compressed and radially deformed into sealing engagement with pipe 12 as shown in FIG. 2. Once set in the position shown in FIG. 2, the sealing effect of packing rings 25 can be tested by applying fluid pressure through injector plug 30, conduit 29, channel 27 and ports 28.
In the event of failure of packing rings 25 to hold the desired pressure, the arrangement of the tool is such that the seals 25 could be deactuated and repaired or replaced, as will be described hereinafter. If it is determined that the packing and sealing is satisfactory, the testing fluid, such as hydraulic fluid, could be substituted with a hard-setting fluid, such as epoxy resin, to provide additional re-enforcing means for the packing rings 25 to insure continued sealing thereof.
As perhaps best seen in FIG. 5, the locking means for locking the seal means in the sealed position will now be described. Sleeve 37 is provided with an annular outwardly facing U-shaped channel 41 in which is mounted an annular split-ring 42. The external surface of ring 42 is provided with a plurality of gripping teeth 43 which are arranged for engagement with matching gripping teeth 44 formed on the internal surface of housing 11 at a position generally adjacent to teeth 43 when actuated. Split-ring 42 also has a plurality of longitudinally extending recesses 45 circumferentially spaced thereabout which are spaced and arranged for axial alignment with a plurality of axially extending bores 46 formed in sleeve 37. Each of the bores 46 is arranged to receive in threaded engagement therewith a ring retainer pin 50, the forward end of which is arranged to be received in one of the recesses 45.
Thus assembled, split-ring 42 is held in the retracted position. It is to be understood that split-ring 42 is generally oversized with respect to recess 41, wuch that upon release thereof, it will spring radially outwardly whereby gripping teeth 43 will grip mating teeth 44 as described above. Hence, in assembling the tool, split-ring 42 is mounted in recess 41 and held in the radially retracted position by insertion retainer pins 50 extending through recesses 45. Once sleeve 37 has been actuated to the right, as shown in FIGS. 2 and 5, to thereby set packing rings 25 as described above, pins 50 may be withdrawn which thus permits split-ring 42 to expand radially outward into engagement with teeth 44, thereby locking sleeve 37 in the actuated position and packing rings 25 in the sealed position. The axial outward end of housing 11 has an annular radially inwardly facing channel or recess 35 in which is received an O-ring 36 to effect sealing between the external surface of sleeve 37 and the end of housing 11.
In some instances, it may be desirable to deactuate the aforesaid setting means and seals, and this is accomplished by use of a plurality of set screws 51 which are provided in a plurality of radially extending threaded bores 52 circumferentially spaced about in matching alignment with pins 50 and recesses 45. By threading set screws 51 radially inwardly to the position shown in FIG. 5, split-ring 42 is thereby urged radially inwardly, thereby disengaging gripping teeth 43 and 44. At this point, alternate ones of set screws 51 may be withdrawn and the adjacent retainer pins 50 reinserted into the respective recesses 45, after which additional set screws 51 may be removed and additional pins 50 reinserted such that all set screws 51 have been removed radially outward and all pins 50 have been moved into the retaining position, whereby split-ring 42 is retained in the non-actuated position. At this point, sleeve 37 can be removed axially from the housing to permit changing or servicing of the packing rings 25, for example, with removing housing 11 from pipe 12.
Referring now to FIG. 3 in particular, the setting means for effecting setting of the aforesaid described seal means will now be described. These setting means generally take the form of removable setting clamp 55 which is formed at one end with a generally U-shaped compression member 56, which is arranged for mounting about flange 38 and supported thereby. It will be observed that member 56 has an annular shoulder 57 which is arranged to abutt against the axial end of the flange 38 to thereby apply compression force thereto.
The opposite end of claim 55 includes another U-shaped compression member 59 which is similar to member 56 and arranged to similarly engage a shoulder 60 formed on the radially outward surface of housing 11, as shown in FIG. 1. Compression member 56 has two lugs 62 attached thereto and spaced at 180 ° from each other and member 59 has two similar lugs 63 attached thereto and similarly spaced. Compression means in the form of two hydraulic cylinder and piston assemblies 65 are attached between each lug 62 and lug 63, as shown in FIG. 5, by means of pins and attaching brackets 66 supported on each of the ends of assemblies 65. Hence, upon application of hydraulic fluid to assemblies 65 to the appropriate sides of the hydraulic pistons therein, a compression force is created which causes compression members 56 and 59 to be drawn together, which in turn causes locking sleeve 37 to be moved axially relative to housing 11, thereby compressing packing rings 25 to the position shown in FIG. 2. In order to assure appropriate parallel alignment of compression members 56 and 59, they are provided with circumferentially spaced guide holes in which are supported a pair of guide rods 67 which assure continued parallel alignment of members 56 and 59 during the actuation step discussed above.
When locking sleeve 37 has been actuated to the desired position and packing rings 25 have been sufficiently axially compressed and radially deformed, then retainer pins 50 may be removed, thereby permitting split ring 42 to expand radially outwardly whereby gripping teeth 43 engage mating gripping teeth 44, to thereby lock sleeve 37 in housing 11 as shown in FIG. 2. Thereafter, pressure can be relieved on hydraulic cylinder and piston assemblies 55, and setting clamp 55 removed for subsequent use on another coupling.
Referring now to FIGS. 1 and 2 in particular, the pipe gripping means of the coupling will be described in greater detail. Compression bowl surface 15 has supported adjacent thereto and spaced circumferentially thereabout in camming engagement therewith a plurality of wedge shaped pipe gripping slips 71, each of which is provided with gripping teeth 72 on the radially inward sides thereof for gripping engagement with pipe 12 upon actuation thereof. Each slip 71 is provided with a longitudinal slot 74 through which is mounted a cap screw 75 which is threaded into compression bowl 14 as shown. Each slot 74 is dimensioned such that it forms shoulders which engage the cap of a cap screw 75, such that each slip 71 is maintained in camming contact with compression bowl surface 15. Hence, upon application of an axial force against the blunt or butt end of each of the slips 71, the slips 71 are thereby urged axially and cammed radially inwardly into gripping engagment with pipe 12, as shown in FIG. 2.
The blunt or butt ends of each of the slips 71 has spaced adjacent thereto a metal compression ring 79 which may be somewhat deformable to accommodate variation in distance of travel of each of the slips 71 during setting thereof, and/or may be dimensioned for slight tilting to accommodate such variation in slip movement.
Ring 79 has mounted axially adjacent thereto spring means in the form of a rubber or other elastomeric compensator ring 80 which is arranged for storing energy when compressed axially, such that it not only transmits axial force but stores energy to maintain a constant bias pressure against compression ring 79. Compensator ring 80 has also mounted adjacent the other side thereof another metal compression ring 81 which is similar to ring 79. The other side of ring 81 is arranged for abutting against the ends of a plurality of longitudinally extending pistons 84, each of which is mounted in one of a plurality of axially extending cylinders 85 provided in circumferentially spaced about positions within housing 11. Upon movement of pistons 84 axially to the right, as shown in FIGS. 1 and 2, metal ring 81, compensator ring 80 and metal ring 79 are urged axially against slips 71, causing the same to be cammed to the previously described setting or gripping position with pipe 12. Because of the compressible nature of compensator ring 80, energy is stored therein during the aforesaid compression which maintains a constant bias force against the blunt ends of each of the slips 71, as shown in FIG. 2.
Tension bowl surface 21 also has mounted radially adjacent thereto another plurality of slips 86 which are identical with slips 71 previously described and each are held in camming engagement with tension bowl surface 21 by a cap screw 87, the same as slips 71 are held in position by cap screws 75. The butt ends of slips 86 have spaced axially adjacent thereto an assemblage comprising a metal ring 88, a rubber or elastomeric compensator ring 89 and another metal ring 90, the construction and operation of which are identical with the previously described rings 79, 80 and 81 and are arranged for applying axial force to slips 86 to thereby actuate the same to gripping engagement with pipe 12 as shown in FIG. 2.
Ring 90 is arranged for abuttment by another plurality of pistons 91, each of which is mounted in one of the cylinders 85 and co-axially aligned with one of the previously described pistons 84. Stated otherwise, each of eh cylinders 85 has two pistons 84 and 91 mounted therein and arranged for axial movement in opposite directions to thereby cause actuation of both pluralities or groups of slips 71 and 86 to the set position.
Housing 11 is provided with an annular conduit 94 which extends circumferentially therein and which communicates radially outwardly through port 95 to an injection plug 96 and radially inwardly through a plurality of ports 97, each of which communicates to one of the cylinders 85 at a point intermediate the adjacent ends of pistons 91 and 84. Housing 11 is also provided with another plug which is identical with plug 96 but spaced at 180 ° circumferentially therefrom which can be used as a bleeder plug to bleed any fluids from cylinders 85 should that be desirable.
Upon application of hydraulic fluid pressure through injector plug 96, port 95, conduit 94 and ports 97 to cylinders 85, the pistons 91 and 84 in each of the cylinders 85 are urged axially apart to effect setting of the slips as described above. Should it become desirable to evacuate the hydraulic fluid and substitute a settable epoxy resin, then the aforesaid bleeder plug can be opened and the hydraulic fluid flowed out while the exposy resin is flowed through injector plug 96 under the required pressure to keep the slips set. Upon setting of the epoxy resin in this instance, the slips are permanently held in the set position, thereby effecting a permanent connection with pipe 12.
By having compression bowl surface 15 and tension bowl surface 21 facing each other and by having slips 71 and 86 constructed and operated as described above, there is provided a coupling which will withstand both tension and compression forces which may be applied axially between housing 11 and pipe 12. In other words, when housing 11 and pipe 12 are submitted to axial compression forces, slips 71 by their contact with compression bowl surface 15 resist such force. When housing 11 and pipe 12 are subjected to axial tension forces, slips 86 by their cooperation with tension bowl surface 21, resist such force, with the result that the tool can withstand both tension and compression without failure or without dislodgement of the slips. Further, by having the spring means in the form of the compensator rings 80 and 89, the respective slips are always under a biasing force which constantly maintains each of the slips in a set position, further insuring the continued operation thereof without failure. It is to be understood that the size and hardness of compensator rings 80 and 89 may be varied depending upon the dimensions of the tool, the line pressure expected in the pipeline and the pressure exerted by the external environment, and these variations can be made without effecting sealing of housing 11 with pipe 12 which is provided by separate sealing means in the form of packing rings 25 previously described.
In operation of the coupling, housing 11 is mounted on pipe 12 generally in the unactuated position as shown in FIG. 1, with the removable setting clamp 55 mounted thereover as shown in FIG. 3. With pipe 12 inserted into housing 11 to the extent shown in FIG. 2, the coupling step can be completed then by applying hydraulic pressure to the proper ends of hydraulic cylinder piston assemblies 65, which in turn causes a compression force on sleeve 37, causing the same to move axially to the right as shown in FIG. 2, thereby axially compressing and radially deforming packing rings 25 to the sealing position shown in FIG. 2. Once such sealing has been effected, testing thereof can be accomplished as described above by the application of another pressurized fluid through injector plug 30. In the event it is determined that the seal is not functioning for some reason, sleeve 37 may be removed in the manner previously described and new packing rings 25 substituted if required, with the necessity of removing housing 11 from pipe 12.
The gripping means are actuated by the application of fluid pressures such as hydraulic pressure through injector plug 96 which is described above causes each of the pistons 91 and 84 in each of the cylinders 85 to apply hydraulic actuated force to thereby set each of the plurality of slips 71 and 86 as described above. If a permanent connection is desired, then the hydraulic fluid can be removed through the previously described bleeder plug and epoxy resin introduced through injector plug 96.
It will thus be observed that this invention provides a coupling which has seal means and actuation means therefor which are separate from the gripping means and the actuation means therefor. The arrangement of the gripping means are such that the tool can resist tension and compression forces both, and partial failure of one system will not impair the effective operation of the other system. Moreover, the arrangement of the sealing system is such that it can be repaired should a malfunction develop without disturbing the gripping system.
While in the foregoing sequence, the seal means were described as being actuated first, it is to be understood that the gripping system could be actuated first and thereafter the sealing system actuated or for that matter, the two could be actuated simultaneously with each other. However, simultaneous actuation is not required since each has separate actuation means operable by separate pressurized fluids which may or may not be from the same source. Moreover, the invention provides a removable setting clamp which may be demounted from the coupling and used for actuating the seal means on other couplings, thereby saving an expense.
Further modifications and alternative embodiments of the apparatus and method of this invention will be apparent to those skilled in the art in view of this description. Accordingly, this description is to be construed as illustrative only and is for the purpose of teaching those skilled in the art the manner of carrying out the invention. It is to be understood that the forms of the invention herewith shown and described are to be taken as the presently preferred embodiment. Various changes may be made in the shape, size and arrangement of parts. For example, equivalent elements or materials may be substituted for those illustrated and described herein, parts may be reversed, and certain features of the invention may be utilized independently of the use of other features, all as would be apparent to one skilled in the art after having the benefit of this description of the invention.
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A hydraulically actuated coupling for effecting a connection to a pipe member or the like which has axially spaced apart pluralities of oppositely biased gripping slips which are continuously urged into gripping engagement between the housing and the pipe. This arrangement permits the pipe coupling to withstand both tension and compression forces thereon and to continuously maintain slips in positive engagement with the pipe. The coupling also has separate seal means which are separately operated by a thrust member which applies axial force to thereby radially deform elastomeric seal members into sealing engagement between the pipe and the housing. The separate actuation means for the slips and for the seal means provides a more fail-safe coupling and one which can be adapted to various pipe sizes and pressure requirements.
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This is a division of application, Ser. No. 667,624 filed Mar. 17, 1976, now U.S. Pat. No. 4,049,574, which was a division of Ser. No. 473,489, filed Mar. 28, 1974, now U.S. Pat. No. 3,989,585.
BACKGROUND OF THE INVENTION
The present invention relates to improved process for the preparation of maleic anhydride from normal C 4 hydrocarbons by the reaction of oxygen with the hydrocarbon in vapor phase over a particular novel catalyst.
The production of dicarboxylic acid anhydride by catalytic oxidation of hydrocarbons is well known. The current principal route for the production of maleic anhydride is the catalytic oxidation of benzene. The direct production of maleic anhydride from the C 4 hydrocarbons has been desirable in the past, but is now even more desirable in view of the particular world shortage of benzene. It can be readily appreciated that direct oxidation of C 4 hydrocarbons would be a hydrocarbon conservation, since for each mol of maleic anhydride prepared from benzene, one mole of benzene, molecular weight 78 is consumed whereas for each mol of the C 4 only 54 to 58 mol weight of hydrocarbon is consumed. The benzene process has consistently produced high conversions and selectivities. Although processes for the oxidation of aliphatic hydrocarbons are reported in the literature, there are certain defects and inadequacies in these processes such as short catalyst life and low yields of product. Furthermore, although many of the prior art methods are generically directed to "aliphatic" hydrocarbons, they are in all practical aspects directed to unsaturated aliphatic hydrocarbons.
A more desirable process for producing maleic anhydride would be a direct oxidation of n-butane. There are several advantages. Principal among these is the greater availability of n-butane as compared to n-butenes or butadiene. Also n-butenes may have higher economic petrochemical utilization than the n-butanes, which are now, often wastefully burned as cheap fuel.
In an early series of patents one of the present inventors developed a unique group of vanadium-phosphorus, oxidation catalysts, i.e., U.S. Pat. Nos. 3,156,705; 3,156,706; 3,255,211; 3,255,212; 2,255,213; 2,288,721; 3,351,565; 3,366,648; 3,385,796 and 3,484,384. These processes and catalysts proved highly efficient in the oxidation of n-butenes to maleic anhydride.
SUMMARY OF THE INVENTION
It has now been discovered that vanadium-phosphorus-oxygen complex type catalyst modified with copper and a Me component, are excellent oxidation catalysts for the conversion of n-C 4 hydrocarbons to maleic anhydride. Surprisingly, the present catalysts are excellent for the direct oxidation of n-butane to maleic anhydride. In addition to n-butane, n-butene, and butadiene can also be used as feeds. The catalyst contains only a minor amount of copper and the Me component. The Me component is generally a metal or metalloid element.
The precise structure of the present complex catalyst has not been determined, however, the complex may be represented by formula
VP.sub.a Cu.sub.b Me.sub.c O.sub.x
wherein Me is Te, Zr, Ni, Ce, W, Pd, Ag, Mn, Cr, Zn, Mo, Re, Sm, La, Hf, Ta, Th, Co, U, Sn, or mixtures thereof, a is 0.90 to 1.3, b is 0.005 to 0.3 and c is 0.001 preferably 0.005 to 0.25. This representation is not an empirical formula and has no significance other than representing the atom ratio of the active metal components of the catalyst. The x in fact has no determinate value and can vary widely depending on the combinations within the complex. That there is oxygen present is known and the O x is representative of this. A more specific group of Me components is Te, Zr, Ni, Ce, W, Pd, Ag, Mn, Cr, Mo, Re, Hr, Ta, Th, Co, U, Sn or mixtures thereof.
A more preferable catalyst is one wherein Me is Te, Ni, Ce, Cr, Mo, Re, Hf, Ta, U, or mixtures thereof.
In one embodiment of the present invention the catalyst complex comprises vanadium-phosphorus, copper, a second metal, Me, and an alkali or alkaline earth metal, (Alk-metal) of group IA or IIA of the Periodic Table of Elements.* This complex may be represented by the configuration
VP.sub.a Cu.sub.b Me.sub.c Alk.sub.d O.sub.x
wherein Me, a, b, c, and x are as described above and Alk is a metal selected from the group of elements of Groups IA and IIA of the Periodic Table of Elements, and d is 0.001 to 0.1. Particular Group IA and IIA elements for the present invention are Li, Na, K, Rb, Cs, Be, Mg, Ca, Sr and Ba. Even more preferably Li, Na, Mg and Ba.
DETAILED DESCRIPTION OF THE INVENTION
The catalyst may be prepared in a number of ways. The catalyst may be prepared by dissolving the vanadium, phosphorus, copper, Me and Group IA and IIA components (referred to herein as alk metals) in a common solvent, such as hot hydrochloric acid and thereafter depositing the solution onto a carrier. The catalyst may also be prepared by precipitating the metal compounds, either with or without a carrier, from a colloidal dispersion of the ingredients in an inert liquid. In some instances the catalyst may be deposited as molten metal compounds onto a carrier; however, care must be taken not to vaporize off any of the ingredients such as phosphorus. The catalyst may also be prepared by heating and mixing anhydrous forms of phosphorus acids with vanadium compounds, copper compounds, Me compounds, and the alk - metal compound. The catalysts may be used as either fluid bed or fixed bed catalyst. In any of the methods of preparation heat may be applied to accelerate the formation of the complex. Although some methods of catalyst preparation are preferred, any method may be used which results in the formation of the catalyst complex containing the specified ratios of vanadium, copper, Me elements, phosphorus and alk metal.
One method to obtain catalysts which produce high yields of maleic anhydride upon oxidation of C 4 hydrocarbons is whereby the catalyst complex is formed in solution and deposited as a solution onto the carrier. According to one solution method, the vanadium is present in solution with an average valence of less than plus 5 in the finally formed complex in solution. Preferably the vanadium has an average valency of less than plus 5 at the time the solution of catalyst complex is deposited onto the carrier, if a carrier is used. The reduced vanadium with a valence of less than 5 may be obtained either by initially using a vanadium compound wherein the vanadium has a valence of less than 5 such as vanadyl chloride, or by initially using a vanadium compound with a valence of plus 5 such as V 2 O 5 and thereafter reducing to the lower valence with, for example, hydrochloric acid during the catalyst preparation to form the vanadium oxysalt, vanadyl chloride, in situ. The vanadium compound may be dissolved in a reducing solvent, such as hydrochloric acid, which solvent functions not only to form a solvent for the reaction, but also to reduce the valence of the vanadium compound to a valence of less than 5. For example, a vanadium compound, a copper compound, a tellurium compound, phosphorus compound and alk metal compound may be dissolved in any order in a suitable reducing solvent and the formation of the complex allowed to take place. Preferably, the vanadium compound is first dissolved in the solvent and thereafter the phosphorus, copper, tellurium and alk metal compounds are added. The reaction to form the complex may be accelerated by the application of heat. The deep blue color of the solution shows the vanadium has an average valence of less than 5. The complex formed is then, without a precipitation step, deposited as a solution onto a carrier and dried. In this procedure, the vanadium has an average valence of less than plus 5, such as about plus 4, at the time it is deposited onto the carrier. Generally, the average valence of the vanadium will be between about plus 2.5 and 4.6 at the time of deposition onto the carrier.
When the above described solution method is employed, reduding agents for the vanadium may be either organic or inorganic. Acids such as hydrochloric, hydrobromic, acetic, oxalic, malic, citric, formic and mixtures thereof such as a mixture of hydrochloric and oxalic may be used. Sulphur dioxide may be used. Less desirably, sulfuric and hydrofluoric acids may be employed. Other reducing agents which may be employed, but which have not been given as desirable catalysts are organic aldehydes such as formaldehyde and acetaldehyde; alcohols such as pentaerythritol, diacetone alcohol and diethanol amine. Additional reducing agents are such as hydroxyl amines, hydrazine, and nitric oxide. Nitric acid and similar oxidizing acids which would oxidize the vanadium from a valence of 4 to 5 during the preparation of the catalyst should be avoided. Generally the reducing agents form oxysalts of vanadium. For example, if V 2 O 5 is dissolved in hydrochloric or oxalic acid, the corresponding vanadium oxysalts are produced. These vanadium oxysalts should have as the salt forming anion an anion which is more volatile than the phosphate anion.
According to this method, the time at which the copper, Me and metal compounds are incorporated into the solution is not critical so long as it is in solution before the catalyst complex is coated onto the carrier. The copper, Me and alk metal compounds may be added after the vanadium compound and the phosphorus compound have been reacted or may be added either before, at the same time or after either the vanadium or phosphorus compound has been added.
Any vanadium, copper, Me, phosphorus and alk metal compounds may be used as starting materials which when the compounds are combined and heated to dryness in air at a temperature of, for example, 300°-350° C. will leave as a deposit a catalyst complex having relative proportions within the described ranges. In the solution methods, preferred are vanadium, copper, Me, phosphorus and alk metal compounds which are essentially completely soluble in boiling aqueous hydrochloric acid at 760 mm. of mercury, containing 37 percent by weight hydrochloric acid. Generally, phosphorus compounds are used which have as the cation an ion which is more volatile than the phosphate anion, for example. H 3 PO 4 . Also, generally any vanadium, copper of Me compound which has as an anion an anion which is either the phosphate ion or an ion which is more volatile than the phosphate anion, for example, vanadyl chloride, copper (II) chloride or tellurium tetrachloride may be used.
In this method, the catalyst complex containing vanadium, copper, Me, phosphorus and Group I or IIA elements may be formed by simply causing the combination of each of the ingredient components in a solution or dispersion. Heat may be applied to accelerate the formation of the complex and one method of forming the complex is by causing the ingredients to react under reflux conditions at atmospheric pressure. Under reflux conditions this solution reaction generally takes about one to two hours.
Although the catalysts prepared by this method may be separately formed and used as pellets, it may be more economical and practical to deposit this material on a carrier such as aluminum oxide, silica or niobium oxide. Before the carrier is combined with the catalyst the solution of catalyst is preferably concentrated to a solution which contains from about 30 to 80 percent volatiles and better results have been obtained when there is from about 50 to 70 percent volatiles by weight. The carrier may be added to the catalyst solution or the catalyst solution may be poured onto the carrier. Less desirably, the Alundum or other carrier may be present during the whole course of reactions to provide the desired vanadium-oxygen phosphorus-alkali metal complex. After the catalyst complex has been coated onto the carrier, the vanadium may be converted to a more active form by heating in the presence of an oxidizing gas.
Another example of the catalyst preparation is to mix with heating at a temperature of about 100° C. to 600° C. an anhydrous phosphoric acid such as ortho-phosphoric acid, pyrophosphoric acid, triphosphoric acid or metaphosphoric acid with a vanadium compound such as vandium pentoxide or ammonium metavanadate, a copper compound such as copper (II) chloride, a Me compound such as tellurium tetrachloride and an alkali such as potassium chloride. After the exothermic reaction between the ingredients the catalyst may be used. The reaction mixture may be formed onto carriers or shaped into forms such as pellets prior to the reaction to form the catalyst.
Another example of the preparation of the catalyst complex is to dissolve the copper, Me and alk metal compounds and a vanadium compound such as ammonium metavanadate or vanadium pentoxide in an aqueous solution of phosphoric acid. After the components have been dissolved the solution is heated until precipitation occurs. The precipitant can then be dried and used as a catalyst, or a carrier may be combined with the liquid phase either before or after the precipitation.
In the various methods of preparation any vanadium, copper, Me, phosphorus and alk metal compounds may be used as starting materials which when the compounds are combined and heated to dryness in air at a temperature of, for example, 300°-350° C. will leave as a deposit a catalyst complex having relative proportions within the above described ranges.
A new method of catalyst preparation which is simple, easy to handle and avoids some of the problems of these prior methods has been devised by Dr. Ralph O. Kerr, one of the coinventors herein. In this method a solution of the vanadium component is prepared by adding a portion of the reducing agent, such as oxalic acid and isopropanol solution to be employed, to a solution of water and phosphoric acid and heating this mixture to a temperature generally of around 50°-80° C. A vanadium compound such as V 2 O 5 is added incrementally to this heated mixture with stirring. The blue solution which indicates vanadium of average valency less than 5, is maintained by added increments of the remaining oxalic acid - isopropanol solution. After concentration of this solution, solutions of copper, alkali and alkaline earth metals and the Me components are added to vanadium solution and this resultant solution concentrated to a paste-like consistancy, which may be coated on a carrier or mixed with a carrier, heated at moderate temperatures, i.e., 250°-500° C. for a few minutes to several hours and prepared in pellets or chips.
The alk-metal may suitably be introduced as compounds such as alkali and alkaline earth metal salts with examples being lithium acetate, lithium bromide, lithium carbonate, lithium chloride, lithium hydroxide, lithium iodide, lithium oxide, lithium sulfate, lithium orthophosphate, lithium meta-vanadate, potassium sulfate, potassium chloride, potassium hydroxide, sodium chloride, sodium hydroxide, rubidium nitrate, ceasium chloride, beryllium nitrate, beryllium sulfate, magnesium sulfate, magnesium bromide, magnesium carbonate, calcium carbonate, calcium chromite, strontium chloride, strontium chromate, barium acetate, barium chlorate, barium tellurate, radium carbonate and the like. Mixtures of two or more alk metal compounds may be used, such as a mixture of lithium hydroxide and sodium chloride or a mixture of lithium chloride and potassium chloride. Preferred alk-metal elements are lithium, sodium and potassium, and mixtures thereof, with lithium being particularly preferred. When the above-described solution method of catalyst preparation is employed, the alkali metal compound will suitably be an alkali metal compound which either has a phosphate anion as the anion, that is a compound such as lithium phosphate, or a compound which has an anion which is more volatile than the phosphate anion.
As the source of phosphorus, various phosphorus compounds may be used, such as metaphosphoric acid, triphosphoric acid, pyrophosphoric acid, ortho-phosphoric acid, phosphorus pentoxide, phosphorus oxyiodide, ethyl phosphate, methyl phosphate, amine phosphate, phosphorus pentachloride, phosphorus trichloride, phosphorus oxybromide and the like.
Suitable copper compounds are the various compounds such as the copper halides, phosphates, oxides, carbonates, sulfates, nitrates, acetates, hydrides, and so forth. Metallic copper may be used. Generally copper compounds are used which either have the phosphate anion as the anion or which have an anion which is more volatile then the phosphate anion. Copper compounds which are soluble in hydrochloric acid are preferred. Compounds such as cuprous oxide, cupric oxide, cuprous chloride, cuprous sulfate, cuprous or cupric sulfide, cupric lactate, cupric nitrate, cupric phosphate, cuprous bromide, cuprous carbonate, cupric sulfate, cupric oxychloride, cuprous hydroxide, cuprous sulfite, cupric acetate, and the like, are useful as starting materials.
The Me component (including Te) is also suitably introduced by employing the various compounds thereof such as the acetates, carbonates, chlorides, bromides, oxides, hydroxides, nitrates, chromates, chromites tellurates, sulfides, phosphates and the like. These compounds are entirely conventional and those of ordinary skill in the art know these materials and can readily determine suitable compounds to prepare the catalyst, with little, if any, experimentation. A few illustrative compounds are tellurium tetrachloride, nickel chloride, cerium (III) nitrate, tungsten dioxide, silver nitrate, manganese (II) sulfate, chromium sulfate, zinc oxalate, rhenium oxide, samarium oxalate, lanthanum hydroxide, thorium nitride, cobalt (II) orthostannate, uranyl sulfate, iron (III) oxide, tin (IV sulfate, boron trichloride, and similar compounds.
Suitable vanadium compounds useful as starting materials are compounds such as vanadium pentoxide, ammonium metavanadate, vanadium trioxide, vanadyl chloride, vanadyl dichloride, vanadyl trichloride, vanadium sulfate, vanadium phosphate, vanadium tribromide, vanadyl formate, vanadyl oxalate, metavanadic acid, pyrovanadic acid, and the like. Mixtures of the various vanadium, Me, phosphorus and copper compounds may be used as starting materials to form the described catalyst complex.
One preferred species of the present vanadium - phosphorus - oxygen complex catalyst contains a minor amount of copper, tellurium and an element or compound of Group IA of the Periodic Table of elements. The catalyst contains vanadium, phosphorus, copper, tellurium and the Group IA component and oxygen chemically bonded together as a complex. Lithium is the preferred Group IA element for use in this species.
Copper is present in minor amounts but in a relatively wide range of about 0.04 to 0.20 atom of copper per atom of vanadium. The copper may be considered an "active" along with vanadium, in that it is undergoing oxidation and reduction. Phosphorus, on the other hand, is a vanadium modifier and tellurium may serve the same purpose in regard to copper. These components of the complex catalyst may serve other functions or may be characterized by others in a different manner, however, the characterization provided above may aid in understanding the mechanism of this catalyst.
The tellurium is present in an amount of 0.001 to 0.2 atom per atom of vanadium and is apparently essential to moderate the activity of catalyst complex, i.e., probably the copper component.
The function of the Group IA element is not completely understood but superior results are obtained when the catalyst contains these elements. Longer useful catalyst life has been observed when the IA element is present, probably due, at least in part, to the partially stabilizing effect of the alkali on phosphorus, copper and tellurium.
The atomic ratio of the total atoms of Group IA elements to vanadium should be about 0.003 to 0.08 atom of alkali per atom of vanadium. The preferred amount of alkali is about 0.01 to 0.04 atom per atom of vanadium.
For the P-V-Cu-Te-IA species and ratios of Cu to V thereof defined above the amount of phosphorus present is critical and has been determined to be 1.05 to 1.2 atoms of phosphorus per atom of vanadium. The preferred amount of phosphorus is in the very narrow range of 1.10 to 1.15 atoms per atom of vanadium. Amounts of phosphorus outside of the broadest range specified have given low yields of maleic anhydride. Within the preferred range of phosphorus content, catalyst gives superior results.
A catalyst support, if used, provides not only the required surface for the catalyst, but gives physical strength and stability to the catalyst meterial. The carrier or support normally has a low surface area as usually measured, from about 0.001 to about 5 square meters per gram. A desirable form of carriers is one which has a dense non-absorbing center and a rough enough surface to aid in retaining the catalyst adhered thereto during handling and under reaction conditions. The carrier may vary in size but generally is from about 21/2 mesh to about 10 mesh in the Tyler Standard screen size. Alundum particles as large as 1/4 inch are satisfactory. Carriers much smaller than 10 to 12 mesh normally cause an undesirable pressure drop in the reactor, unless the catalysts are being used in a fluid bed apparatus. Very useful carriers are Alundum and silicion carbide or Carborundum. Any of the Alundums or other inert alumina carriers of lower surface may be used. Likewise, a variety of silicon carbides may be employed. Silica gel may be used.
Other materials which can serve as carriers are Nb 2 O 5 , WO 3 , Sb 2 O 3 and mixtures of these and other supports. The support material is not necessarily inert, that is, the particular support may cause an increase in the catalyst effiency by its chemical or physical nature of both.
The amount of the catalyst complex on the carrier is usually in the range of about 15 to about 95 weight percent of the total weight of complex plus carrier and preferably in the range of 50 to 90 weight percent and more preferably at least about 60 weight percent on the carrier. The amount of the catalyst complex deposited on the carrier should be enough to substantially coat the surface of the carrier and this normally is obtained with the ranges set forth above. With more absorbent carriers, larger amounts of material will be required to obtain essentially complete coverage of the carrier. In a fixed bed process the final particle size of the catalyst particles which are coated on a carrier will also preferably be about 21/2 to about 10 mesh size. The carriers may be of a variety of shapes, the preferred shape of the carriers is in the shape of cylinders or spheres. Although more economical use of the catalyst on a carrier in fixed beds is obtained, as has been mentioned, the catalyst may be employed in fluid bed systems. Of course, the particle size of the catalyst used in fluidized beds is quite small, usually varying from about 10 to about 150 microns, and in such systems the catalyst normally will not be provided with a carrier but will be formed into the desired particle size after drying from solution.
Inert diluents such as silica may be present in the catalyst, but the combined weight of the essential active ingredients of vanadium, oxygen, phosphorus, copper, Me, and alk metal should preferably consist essentially of at least about 50 weight percent of the composition which is coated on the carrier, if any, and preferably these components are at least about 75 weight percent of the composition coated on the carrier, and more preferably at least about 95 weight percent.
The oxidation of the n-C 4 hydrocarbon to maleic anhydride may be accomplished by contacting e.g. n-butane, in low concentations in oxygen with the described catalyst. Air is entirely satisfactory as a source of oxygen, but synthetic mixtures of oxygen and diluent gases, such as nitrogen, also may be employed. Air enriched with oxygen may be employed.
The gaseous feed stream to the oxidation reactors normally will contain air and about 0.5 to about 2.5 mol percent hydrocarbons such as n-butane. About 1.0 to about 1.5 mol percent of the n-C 4 hydrocarbon are satisfactory for optimum yield of product for the process of this invention. Although higher concentrations may be employed, explosive hazards may be encountered. Lower concentrations of C 4 , less than about 1 percent, of course, will reduce the total yields obtained at equivalent flow rates and thus are not normally economically employed. The flow rate of the gaseous stream through the reactor may be varied within rather wide limits but a preferred range of operations is at the rate of about 50 to 300 grams of C 4 per liter of catalyst per hour and more preferably about 100 to about 250 grams of C 4 per liter of catalyst per hour. Residence times of the gas stream will normally be less than about 4 seconds, more preferably less than about one second, and down to a rate where less efficient operations are obtained. The flow rates and residence times are calculated at standard conditions of 760 mm. of mercury and at 25° C. A preferred feed for the catalyst of the present invention for conversion to maleic anhydride is a n-C 4 hydrocarbon comprising a predominant amount of n-butane and more preferably at least 90 mol percent n-butane.
A variety of reactors will be found to be useful and multiple tube heat exchanger type reactors are quite satisfactory. The tubes of such reactors may vary in diameter from about 1/4 inch to about 3 inches, and the length may be varied from about 3 to about 10 or more feet. The oxidation reaction is an exothermic reaction and, therefore, relatively close control of the reaction temperature should be maintained. It is desirable to have the surface of the reactors at a relatively constant temperature and some medium to conduct heat from the reactors is necessary to aid temperature control. Such media may be Woods metal, molten sulfur, mercury, molten lead, and the like, but it has been found that eutectic salt baths are completely satisfactory. One such salt bath is a sodium nitrate-sodium nitrite-potassium nitrate eutectic constant temperature mixture. An additional method of temperature control is to use a metal block reactor whereby the metal surrounding the tube acts as a temperature regulating body. As will be recognized by the man skilled in the art, the heat exchange medium may be kept at the proper temperature by heat exchangers and the like. The reactor or reaction tubes may be iron, stainless steel, carbon-steel, nickel, glass tubes such as Vycor and the like. Both carbon-steel and nickel tubes have excellent long life under the conditions of the reactions described herein. Normally, the reactors contain a preheat zone of an inert material such as 1/4 inch Alundum pellets, inert ceramic balls, nickel balls or chips and the like, present at about one-half to one-tenth the volume of the active catalyst present.
The temperature of reaction may be varied within some limits, but normally the reaction should be conducted at temperatures within a rather critical range. The oxidation reaction is exothermic and once reaction is underway, the main purpose of the salt bath or other media is to conduct heat away from the walls of the reactor and control the reaction. Better operations are normally obtained when the reaction temperature employed in no greater than about 100° C. above the salt bath temperature. The temperature on the reactor, of course, will also depend to some extent upon the size of the reactor and the C 4 concentration. Under usual operating conditions, in compliance with the preferred procedure of this invention, the temperature in the center of the reactor, measured by thermocouple, is about 375° C. to about 550° C. The range of temperature preferably employed in the reactor, measured as above, should be from about 400° C. to about 515° C, and the best results are ordinarily obtained at temperatures from about 420° C. to about 470° C. Described another way, in terms of salt bath reactors with carbon steel reactor tubes about 1.0 inch in diameter, the salt bath temperature will usually be controlled between about 350° C. to about 550° C. Under normal conditions, the temperature in the reactor ordinarily should not be allowed to go above about 470° C. for extended lengths of time because of decreased yields and possible deactivation of the novel catalyst of this invention.
The reaction may be conducted at atmospheric, super-atmospheric or below atmospheric pressure. The exit pressure will be at least slightly higher than the ambient pressure to insure a positive flow from the reaction. The pressure of the inert gases must be sufficiently high to overcome the pressure drop through the reactor.
The maleic anhydride may be recovered by a number of ways well known to those skilled in the art. For example, the recovery may be by direct condensation or by adsorption in suitable media, with subsequent separation and purification of the maleic anhydride.
In the following examples, two types of reactors were employed. The results of the tests in the two reactors are qualitatively comparable. i.e., an increase in maleic anhydride yield in the smaller equipment will be reflected in the larger equipment, although the absolute members are different.
"A" Reactor
The "A" reactor comprised a 4-tube cylindrical brass block (8" O.D. × 18") reactor made of alloy 360. The block was heated by two 2500 watt (220 volt) cartridge heaters controlled by means of a 25 amp. thermoelectric proportional controller with automatic reset. Prior to its insulation, the block was tightly wound with a coil of 3/8" copper tubing. This external coil was connected to a manifold containing water and air inlets for cooling of the reactor block. The reactors were made of a 304 stainless steel tube, 1.315" O.D. and 1.049" I.D., 231/2" long, containing a centered 1/8" O.D. stainless steel thermocouple well. The lower end of the reactor was packed with a 1" bed of 3 mm pyrex head. The next 12" of the reactor were packed with catalyst (1/8"× 1/8" pellets or 6-12 mesh granules) followed by about a 10"40 bed of 3 mm pyrex beads. The gas streams are separately metered into a common line entering the top of the reactor. The reaction vapors are passed through two 2000 ml. gas scrubbing bottles containing 800 ml of water. The vapors from the scubbers then go through a wet test meter and are vented. The inlet gases are sampled before entering the reactor and after the water scrubbers. The feed is normally 0.5 to 1.8 mol % C 4 , e.g., n-butane, in air, adjusted to maintain a desired temperature. In addition, operating temperature can be further controlled by dilution of the air with an inert gas.
The inlet gases and water scrubbed outlet gases were analyzed by gas chromatography using the peak area method. Butane, carbon dioxide and any olefins or diolefins present in the gas streams were determined using a 1/4" column with a 5' foresection, containing 13 wt.% vacuum pump oil on 35/80 mesh chromosorb, followed by a 40' section containing 26 wt. % of a 70-30 volume ratio of propylene carbonate to 2,4-dimethylsulfolane on 35/80 mesh chromosorb. The analysis was conducted at room temperature with hydrogen as the carrier gas (100 ml/minute). Carbon monoxide was analyzed on a 1/4" column with a 3' foresection of activated carbon followed by a 6' section of 40/50 mesh 5A molecular sieves. This analysis was run at 35° C with helium as the carrier gas (20 psi).
The water scrub solutions were combined and diluted to 3000 ml. in a volumetric flask. An aliquot of this solution was titrated with 0.1 N sodium hydroxide solution to determine maleic acid (first end point) and weak acids in solution and titrated to determine the carbonyls, using hydroxylamine hydrochloride.
"B" Reactor
The "B" reactor employed 300 milliliters of catalyst packed in a 3 foot carbon steel tube, 3/4 inch inside diameter, with inert 1/4 inch Alundum pellets on top of the catalyst material to a height 1/3 of the height of the catalyst. Some runs in the "B" procedure were carried out in larger reactors however, the results as reported herein are equivalent with the 3' reactor.
The reactors were encased in a 7% sodium nitrate -40% sodium nitrite -53% potassium nitrite eutectic mixture constant temperature salt bath. The reactor was slowly warmed to 400° (250°-270° C air passing over catalyst) while passing a gas stream containing 0.5 to 0.7 mol percent n-butane and air over the catalyst beginning at about 280° C. The reactor outlet was maintained at 1 p.s.i.g. After the reactor had reached 400° C., the catalyst was aged by passing the n-butane - air mixture therethrough for 24 hours. The n-butane - air and temperature was increased to obtain a maximum throughput. The n-butane in the feed is increased to 1.0-1.5 mol percent to obtain 80-90% conversion. The salt bath is operated at a maximum of 420° C. The maximum throughput is achieved in relation to the maximum salt bath temperature and a maximum hot spot of about 450° C. The hot spot is determined by a probe through the center of the catalyst bed. The temperature of the salt bath can be adjusted to achieve the desired relationship between the conversion and flow rates of the n-C 4 - air mixture. The flow rate is adjusted to about 85% conversion and the temperature relations given above. Generally, flow rates of about 30 to 75 grams of hydrocarbon feed per liter hour are used. The exit gases were cooled to about 55°-60° C. at about 1/2 p.s.i.g. Under these conditions, about 30 -50% of the maleic anhydride condenses out of the gas stream. A water scrubber recovery and subsequent dehydration and fractionation were used to recover and purify the remaining malic anhydride in the gas stream after condensation. The combined maleic anhydride recovered is purified and recovered at a temperature of about 140° - 145° C. overhead and 145° C. bottoms temperatures in a fractionator. The purified product had a purity of 99.9+ percent maleic anhydride.
EXAMPLE 1
The following procedure was employed in preparing the various catalysts modified to achieve the variation in atomic ratios recited in the Examples.
Typical Method of Preparation
(90 pts VP 1 .185 Cu 0 .072 Te 0 .018 Li 0 .017 O x -- 10 pts Nb 2 O 5 )
(a) v 2 o 5 = 118.17 g 1.300 mole V
oxalic acid = 120 g
isopropanol = 120 ml
Water = 2200 ml.
H 3 po 4 (85%) = 177.67 g 1.541 mole P.
(b) cuCl 2 = 12.5 g 0.0936 mole Cu
LiCl = 0.94 g 0.0221 mole Li
Water = 50 ml. Other Alk-metal compounds can be used in addition to or in place of LiCl.
(C) TeO 2 = 3.73 g 0.0234 mole Te
Hcl = 10 ml. In addition to TeO 2 or in place thereof the other metal components (Me) of the catalyst are dissolved herein.
(D) Nb 2 O 5 = 26.5 g.
Solutions "B" and "c" was prepared by gently warming on a hot plate.
Solution "A" was prepared as follows:
Approximately 1/2 of the oxalic acid and isopropanol are added to the water along with the phosphoric acid. The 4-liter beaker is stired on a magnetically stirred hot plate. When the solution reaches 75° C it is maintined at this temperature and the V 2 O 5 is added in small increments maintaining a blue vanadyl phosphate solution. The remaining oxalic acid and isopropanol are added as needed to maintain the blue solution. This solution is then concentrated to a volume of 700 ml. and is then transferred to a large evaporating dish and the "B" and "C" solutions added. Stirring is continued and the solution is concentrated to a paste like consistency. The Nb 2 O 5 is added and slurried with the paste. It is then dried in an oven at 130° C. overnight. It is broken up and calcined at 350° C. in an air atmosphere for 6 hours. It is then either used as a chip (6-8 mesh) or ground and compressed into 1/8"× 1/8" tablets.
The term "yield" used herein means conversion × selectivity.
Examples A1-A3
These examples were carried out in the "A" reactor. The effect of several catalyst supports were evaluated. The catalyst composition is represented by the atom ratio VP 1 .2 Cu 0 .026 Te 0 .026 Li 0 .039 O x . Temperature conditions, wt. percent catalyst, conversions and results are given in Table I.
Table I.__________________________________________________________________________ Wt.% Reactor Hot Spot Butane % S Mol % yld.Ex. Support Cat. Temp. ° C Temp. ° C Conv. % M.A. M.A.__________________________________________________________________________A1 Nb.sub.2 O.sub.5 70 450 483 83.61 42.12 35.22A2 PAC.sup.2 70 450 467 59.32 56.05 33.25A3 Celite.sup.3 70 450 470 51.93 49.13 25.51__________________________________________________________________________ .sup.1 Based on total wt. of catalyst and support. .sup.2 PAC = Phosphoric acid carrier. .sup.3 Celite = Johns Manville No. 545 Celite calcined at 1000° C.
EXAMPLES A4 to A13
These examples demonstrate various Me components found suitable in the VP a Cu b Me c Alk d O x type catalysts of the present invention. In a large number of these examples, Te and a second Me component are employed. The method of preparation is that described in Example 1. The active components are specified for each example in atom ratio (except for oxygen) in Table II. The support and total weight % of catalyst and temperatures and results are provided in Table II also. The "A" apparatus and procedure were used. All catalysts were on stream for at least 100 hours when data was taken on results.
EXAMPLES B1 to B10
Using the apparatus and procedure "B" the variation in P ratio was examined. The data presented below in Table III tends to demonstrate the preferred range of atom ratio of phosphorus to vanadium for the species of complex comprising phosphorus, vanadium, copper, tellurium and an alkali or alkaline earth metal (with or without additional Me components). The feed was n-butane (≅ 99% n-butane).
Examples B1 - B3 demonstrate P/V atomic ratios within (B1 and B2) and above (B3) the preferred range. Other comparisons tending to show the detrimental effect of too little phosphorus relative to vanadium are present in examples B4, B5, and B8 and B10. The significance of the preferred range of P/V atomic ratio, i.e., 1.05 to 1.2 for the P, V, Cu, Te, Alk-metal O composition is seen to hold even when other components are added, as disclosed, or the amount of carrier is varied.
EXAMPLES B11 to B15
Employing the procedure and apparatus "B" a series of runs with related catalyst complex demonstrates the advantage of high weight percent of catalyst complex to carrier. The temperature of the reaction is considerably reduced when the carrier is reduced, while the product distribution to maleic anhydride remains high. This data is shown in Table IV. The feed was ≅ 99% n-butane.
EXAMPLES B16 to B34
These examples demonstrate various of the species of the pesent inventions and clearly indicate the scope. The catalyst are prepared according to example 1 and the procedure and equipment of reactor "B" were employed. The results are given in Table V. The feed was ≅ 99% n-butane. All catalysts were on stream for at least 300 hours when data was taken.
TABLE II.__________________________________________________________________________ Wt.% Reactor Hot Spot Butane.sup. % Selectivity Mol %ExampleCatalyst Complex Support Catalyst Temp. ° C. Temp. ° C. Conv. % M.A. Yld__________________________________________________________________________ M.A.A4 VP.sub.1.2 Cu.sub.0.026 Te.sub.0.026 Li.sub.0.039 O.sub.x Nb.sub.2 O.sub.5 70 450 483 83.61 42.12 32.82A5 VP.sub.1.2 Cu.sub.0.026 Te.sub.0.026 Ni.sub.0.025 Li.sub.0.039O.sub.x Nb.sub. 2 O.sub.5 70 450 474 62.21 52.76 35.22A6 VP.sub.1.2 Cu.sub.0.026 Te.sub.0.026 Cc.sub.0.026 Li.sub. 0.039O.sub.x Nb.sub.2 O.sub.5 70 430 466 61.18 47.86 29.28A7 VP.sub.1.2 Cu.sub.0.026 Cc.sub.0.026 Li.sub.0.039 O.sub.x Nb.sub.2 O.sub.5 70 420 445 59.43 49.12 29.19A8 VP.sub.1.2 Cu.sub.0.026 Te.sub.0.026 Ni.sub.0.03 Li.sub.0.039O.sub.x None 70 450 482 63.83 46.36 29.59A9 VP.sub.1.2 Cu.sub.0.026 Te.sub.0.026 W.sub.0.056 Li.sub. 0.039O.sub.x Nb.sub.2 O.sub.5 70 440 491 52.43.sup.2 45.09 23.64 A10 VP.sub.1.2 Cu.sub.0.026 Cr.sub.0.026 Te.sub.0.052 Li.sub.0.039O.sub.x None 70 420 450 84.75 52.17 44.22 A11 VP.sub.1.185 Cu.sub.0.072 Te.sub.0.018 Na.sub.0.017 O.sub.x Nb.sub.2 O.sub.5 10 440 463 73 48 35 A12 VP.sub.1.185 Cu.sub.0.072 Te.sub.0.018 Ba.sub.0.017 Nb.sub.2 O.sub.5 10 440 465 64 44 28 A13 VP.sub.1.185 Cu.sub.0.072 Te.sub.0.018 Mg.sub.0.937 Nb.sub.2 O.sub.5 10 440 457 73 41 30__________________________________________________________________________ .sup.1 N-butane purity 99 mol % .sup.2 Feed contained 1 part air, 2 parts N.sub.2.
TABLE III__________________________________________________________________________Atom Wt. %Ratio Nb.sub.2 O.sub.5 Temperature ° C Product Yield Mol %ExampleP/V Carrier Salt Bath Hot Spot CO + CO.sub.2 MA Unreacted Butane__________________________________________________________________________B1.sup.11.1 50 435 447 36.5 48.5 11.5B2.sup.21.13 50 446 475 29 40.5 27B3.sup.31.25 50 442 445 37.4 48.2 20B4.sup.40.90 40 447 457 52.6 15.2 32B5.sup.51.1 15 419 444 34.7 48.6 16B6.sup.60.90 50 437 445 53 3.3 45B7.sup.71.11 10 438 460 31.7 51.2 13.5B8.sup.81.0 40 420 425 38 6.6 55B9.sup.91.16 2 437 448 41.2 42.7 16.1 B10.sup.100.90 50 430 445 54 1.8 45Footnote: Table of Catalyst Complex Compositions of Table IIIAtomic Ratios Wt. % andFootnoteV.sub.2 O.sub.5 P.sub.2 O.sub.5 CuO TcO.sub.3 Li.sub.2 O Additional Components__________________________________________________________________________(.sup.1)44 50 3.0 1.0 2.0 None(.sup.2)43.46 48.94 2.2 2.2 3.3 None(.sup.3)42 52 3.5 .5 2.0 None(.sup.4)48.5 43.69 2.2 2.2 3.3 Cr.sub.2 O.sub.3 2 wt. %(.sup.5)45 49.5 1.5 1.5 1.0 CrO.sub.3 0.4 wt. %(.sup.6)48.5 43.69 2.2 2.2 3.3 Co.sub.2 O.sub.3 2 wt. %(.sup.7)44.8 49.7 3.0 1.5 1.0 CoCl.sub.2 ·6H.sub.2 O 1.1 wt. %(.sup.8)46.1 46.1 2.2 2.2 3.3 WO.sub.3 10 wt. %(.sup.9)43.8 50.7 3.0 1.5 1.0 WO.sub.3 13 wt. %(.sup.10)48.5 43.7 2.2 2.2 3.3 MnO.sub.2 2 wt. %__________________________________________________________________________
TABLE IV__________________________________________________________________________Wt. % Actives Based Temperature Atomicon Total Weight of ° C Ratio Yield Mol %ExampleActives and Carrier.sup.(6) Salt Hot Spot P/V CO + CO.sub.2 MA Unreacted Butane__________________________________________________________________________B11.sup.150 446 475 1.13 29 40.5 27B12.sup.250 435 447 1.14 36.5 48.5 11.5B13.sup.380 411 432 1.10 35 52.8 13.1B14.sup.4 92.5 427 436 1.18 29.4 53.6 15B15.sup.595 423 -- 1.11 31.9 53.4 15Footnote to Table IV Catalyst Complex CompositionAtomic Ratios (No Additives)Footnote V.sub.2 O.sub.5 P.sub.2 O.sub.5 CuO TcO.sub.3 Li.sub.2 O__________________________________________________________________________(.sup.1) 43.46 48.94 2.2 2.2 3.3(.sup.2) 44 50 3.0 1.0 2.0(.sup.3) 45 49.5 3.0 1.5 1.0(.sup.4) 41.86 49.63 6.0 1.5 1.0(.sup.5) 44.8 49.7 3.0 1.5 1.0__________________________________________________________________________ .sup.(6) Carrier Nb.sub.2 O.sub.5 -
TABLE V__________________________________________________________________________Wt. % Catalyst Complex Temperature YieldCar- Atomic Ratio ° C Mol % UnreactedEx. rier.sup.(1) V.sub.2 O.sub.5 P.sub.2 O.sub.5 CuO TcO.sub.3 Li.sub.2 O Wt. % Salt Hot Spot CO + CO.sub.2 MA Butane__________________________________________________________________________B16 55.sup.(2) 43 52 2.5 1.5 2.0 -- 440 447 29 28 43B17 15 45 49.5 3.0 1.5 1.0 CrO.sub.3 0.5% 419 444 34.7 48.6 16B18 7.5 45.5 50.5 3.0 0 1.0 MnO.sub.2 0.8% 407 438 28.6 53.6 17.7B19 7.5 45.5 50.5 3.0 0 1.0 MoO.sub.3 1.0% 408 450 30 51.5 18B20 7.5 43.6 50.6 5.0 0 .8 Mo0.sub.3 --0.55% Ni.sub.2 O.sub.3 --0.3% 407 422 28 52.5 19B21 20 42 42.5 3.0 1.5 1.0 Sb.sub.2 O.sub.3 --15% 412 428 45 31.5 24B22 15 45 49.5 3.0 1.5 1.0 NH.sub.4 ReO.sub.4 --0.67% 430 443 35.7 57.4 6.9B23 2 43.8 50.7 3.0 1.5 1 WO.sub.3 13% 437 448 41.2 42.7 16.1B24 0 43 51 3.0 1.0 2.0 SnO.sub.2 50% 447 455 44 40.7 15.2B25 10 44.8 49.7 3.0 1.5 1.0 Ni.sub.2 O.sub.3 0.85% 415 452 30.9 51.3 18B26 7.5 43.1 50.1 5.0 1.0 0.8 Ni.sub.2 O.sub.3 --0.3% Re.sub.2 0.sub.7 403.3% -- 31.2 53.4 15.4 MoO.sub.3 --0.6%B27 7.5 43.5 50.5 5.0 0 1.0 PdCl.sub.2 --0.09% 425 445 33.3 48.7 18B28 7.5 44.7 50.3 5.0 0 0 Ag.sub.2 O--0.9% 436 442 56 24 20B29 7.5 44.7 50.3 5.0 0 0 CeO.sub.2 --0.9% 406 430 33 46.5 21B30 0 43.3 50.2 4.5 1.0 1.0 Ni.sub.2 O.sub.3 --0.6% Ta.sub.2 O.sub.5 430% 457 31 50 19B31 7.5 44.7 50.3 5.0 0 0 HfO.sub.2 2% 399 438 25.5 50 23B32 7.5 44.7 50.3 5.0 0 0 UO.sub.2 0.9% 411 447 31 51 19B33 15 45 49.5 3.0 1.5 1.0 Z.sub.1 OSO.sub.4 1.4% 424 445 39.6 50.1 10.2B34 7.5 44.7 50.3 5.0 0 0 ThO.sub.2 2.16% 419 450 30.0 47.5 24B35 7.5 44.7 50.3 5.0 0 0 HfO.sub.2 2.2 BaO 1% 408 423 34 47 18__________________________________________________________________________ .sup.(1) Unless specified otherwise the carrier is Nb.sub.2 O.sub.5 .sup.(2) Carrier is WO.sub.3
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A catalyst complex useful for converting normal C 4 hydrocarbons to maleic anhydride in vapor phase comprising as components vanadium, phosphorus, copper, an element selected from the group of Te, Zr, Ni, Ce, W, Pd, Ag, Mn, Cr, Zn, Mo, Re, Sm, La, Hf, Ta, Th, Co, U, and Sn, preferably with an alkali or alkaline earth metal.
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FIELD OF THE INVENTION
[0001] This invention relates to a fuel cell operating on a hydrogen-rich organic fuel that is initially in a liquid form directly fed via diffusion into the anode; but the fuel turns into a vapor form when it comes in contact with the catalyst phase in the anode. The diffusion process is preferably driven by a capillarity force without using a liquid delivery pump. The invention specifically relates to a local vapor fuel cell (LVFC) such as a methanol vapor fuel cell (MVFC) or ethanol vapor fuel cell (EVFC).
BACKGROUND OF THE INVENTION
[0002] A fuel cell is a device which converts the chemical energy into electricity. A fuel cell differs from a battery in that the fuel and oxidant of a fuel cell are supplied from sources that are external to the cell, which can generate power as long as the fuel and oxidant are supplied. A particularly useful fuel cell for powering portable electronic devices is a direct methanol fuel cell (DMFC) in which the fuel is a liquid methanol/water mixture and the oxidant is air or oxygen. Protons are formed by oxidation of methanol and water at the anode (fuel electrode) and pass through a proton-exchange membrane (or polymer electrolyte membrane, PEM) from the anode to the cathode (oxidant electrode). Electrons produced at the anode in the oxidation reaction flow in the external circuit to the cathode, driven by the difference in electric potential between the anode and cathode and can therefore do useful work.
[0003] The electrochemical reactions occurring in a direct methanol fuel cell which contains an acid electrolyte are:
Anode: CH 3 OH+H 2 O→CO 2 +6H + +6e − (1)
Cathode: 3/2O 2 +6H + +6e − →3H 2 O (2)
Overall: CH 3 OH+3/2O 2 →CO 2 +2 H 2 O (3)
[0004] The DMFC and other proton-exchange membrane fuel cells (PEMFCs) use a hydrated sheet of a perfluorinated acid-based ionomer membrane as a solid electrolyte. The electrodes each typically containing a catalyst phase (usually a thin catalyst layer) are intimately bonded to each side of the membrane. This membrane is commercially available from either DuPont (under the trade name Nafion®) or from Dow Chemical. Many catalysts to promote methanol oxidation (Reaction 1) have been evaluated. Examples include: (1) noble metals, (2) noble metal alloys, (3) alloys of noble metals with non-noble metals, (4) chemisorbed layers on Pt, (5) platinum with inorganic material, and (6) redox catalysts. Based on literature reports, Pt—Ru appears to be the best methanol-oxidation catalyst in acidic electrolytes.
[0005] The methanol/water feed to a DMFC may be in the liquid or vapor phase. If fuel cells using liquid fuel are available in small size, they would be able to power small-sized electronic devices for a long time. However, conventional DMFCs require pumps and blowers to feed liquid fuel to the fuel cell (e.g., S. Surampudi, et al., U.S. Pat. No. 6,248,460, Jun. 19, 2001). The resulting power system is complex in structure and large in size. One way to overcome this problem is to utilize capillary action to feed liquid fuel, without using a liquid delivery pump.
[0006] However, a fuel cell of this type still has the following disadvantages: (1) poor performance due to low electrode reactivity and (2) low fuel utilization efficiency due to methanol cross-over from the anode through the electrolyte membrane to the cathode. This problem of methanol crossing over without being reacted is relatively more severe in a fuel cell with a pressurizing pump than in one without a pump.
[0007] It is believed that methanol vapor cells that operate at higher temperatures are advantageous in that the step of methanol ionization to produce protons (e.g., Reaction (1)) proceeds more rapidly in these cells (e.g., as suggested in A. A. Kulikovsky, et al. “Two-dimensional simulation of direct methanol fuel cell,” in Journal of the Electrochemical Society, 147 (3) (2000) 953-959). Presumably, a higher temperature results in a higher catalytic electrode activity and the faster reaction leads to a reduction in fuel cross-over. However, in the conventional DMFC of a vapor feed type, methanol (as a liquid fuel) is introduced by a pump into a vaporizer which vaporizes methanol with the resulting methanol vapor then being fed to the fuel cell by a blower. Unconsumed methanol vapor discharged from the outlet of the fuel electrode is recycled to the methanol tank through a condenser. This process needs a complex system (including a pump, a vaporizer, a blower, and a condenser) and, hence, is not suitable for powering small-sized electronic devices.
[0008] Tomimatsu, et al. (U.S. Pat. No. 6 , 447 , 941 , Sep. 10, 2002) disclosed a fuel cell in the form of stacked unit cells each having a power generating section composed of a fuel electrode, an oxidant electrode, and an electrolyte plate held therebetween. The unit cells are placed on top of one another. In this fuel cell, a liquid fuel is introduced into each unit cell by the capillary action and evaporated in each unit cell in a fuel evaporating layer, so that the fuel electrode is supplied with the evaporated fuel. This is a very interesting fuel cell design since it makes use of the two sound approaches: liquid feed by capillary action and vapor state reaction. However, the fuel cell configuration is still too complex since each unit cell contains, among other layers, separate anode, liquid-permeating, and fuel evaporating layers. Too many layers make the fuel cell more tedious to make and more costly.
[0009] One object of the present invention is to provide a simpler configuration for a fuel cell that operates primarily on an organic fuel vapor. A specific object of the present invention is to provide a fuel cell that operates on a diffusion-fed methanol/water liquid fuel, which is then vaporized in situ at or near the anode catalyst prior to being ionized to produce protons.
[0010] From a systems standpoint, fuel cell operation on liquid methanol-water mixture containing some of the corresponding vapor is more advantageous. Therefore, another object of the present invention is to provide a fuel cell that operates on an organic fuel such as methanol that is at least partially vaporized when in contact with the anode catalyst.
BRIEF SUMMARY OF THE INVENTION
[0011] The present invention provides a light-weight, compact fuel cell that is well-suited to powering portable electronic devices. The invented local vapor fuel cell (LVFC) is composed of one or several unit cells that are physically stacked together and are electrically connected in series to provide a desired voltage level. Each unit cell comprises (A) an anode receiving a liquid fuel from a liquid fuel source substantially through diffusion; (B) an electrolyte plate (or proton exchange membrane, PEM) having a first surface adjacent to the anode; and (C) a cathode adjacent to a second surface of the electrolyte plate and opposite to the anode. The anode is provided with a heating environment to at least partially vaporize the liquid fuel inside the anode to produce fuel vapor near or at the catalyst phase. The catalyst phase ionizes the fuel vapor or the vapor-liquid mixture to produce protons that migrate through the PEM (e.g., a polymer electrolyte membrane) to the cathode side. The catalyst phase preferably forms a thin layer adjacent to the electrolyte plate.
[0012] A special feature of the presently invented LVFC is that the fuel (e.g., methanol/water mixture) is supplied initially in a liquid form into the anode primarily via diffusion, preferably under the action of a capillary force. To accomplish this function, the anode may be made to comprise a porous fuel-permeating material being in fluid communication with a liquid fuel source and receiving the liquid fuel therefrom. However, the liquid fuel is vaporized, partially or completely, just before or when it comes in contact with a catalyst. This heated environment allows the fuel vapor or vapor-liquid mixture to react at a higher temperature in a more efficient manner for proton generation. The heating environment may receive the heat generated by the electrochemical reactions occurring at the cathode. Alternatively or additionally, the heating environment may receive the heat from joule heating by passing a current through the anode. This current may flow through a thin wire that is preferably localized in the vicinity of the catalyst phase. The current may be provided intermittently on demand with the assistance of a temperature sensor and a control circuit. Other preferred embodiments of the present invention include several configurations of multiple-cell fuel cell devices with each of these cells exhibiting the aforementioned features.
[0013] The LVFC that relies on a heating element to provide additional heat to help locally vaporize the liquid fuel at the anode catalyst phase is hereinafter referred to as an extrinsically controlled LVFC or actively controlled LVFC. The FVFC that relies primarily on the internally generated heat due to electrode reactions is referred to as an intrinsically controlled LVFC or passively controlled LVFC. The advantages of such an extrinsically controlled LVFC includes:
(1) The amount of electrical power needed to generate the local joule heat represents only a very small fraction of the total amount of power that a fuel cell can provide. The resulting improvement in the power output considerably more than compensates for the power loss that is required to locally vaporize the fuel. (2) Since the heat is generated locally to vaporize the liquid fuel near the anode, there is very little heat loss to the outside environment. By contrast, the current direct methanol fuel cell of a direct vapor feed type requires a vaporizer and a blower to deliver the vaporized fuel from the vaporizer to the fuel cell body through a pipe. This procedure is prone to heat energy loss. Besides, the combined vaporizer-blower-pipe makes the fuel cell bulky and heavy. (3) The vaporous fuel at a higher temperature means a faster and more efficient catalytic reaction at the anode catalyst site. This reaction condition promotes essentially full conversion of the fuel into the desired electrons and protons, thereby minimizing methanol crossover from the anode to the cathode side through the electrolyte. A reduced methanol crossover implies not only a higher electro-oxidation of methanol-water fuel at the anode, but also less methanol “poisoning” of the cathode catalyst which allows better contacts between oxygen and the cathode catalysts. (4) The liquid fuel feeding via capillarity pressure-driven diffusion of liquid fuel through the anode makes it possible to have a highly compact fuel cell assembly due to the fact that no liquid fuel pump or vapor fuel blower is needed in the LVFC.
[0018] The above extrinsically controlled LVFC, in practice, needs a temperature sensor, a heating element, and a simple temperature-controlling circuit. The intrinsically controlled LVFC has the following added advantage:
(5) The fuel cell geometry (size and shape) and material compositions involved can be selected in such a manner that the methanol-water fuel is in a vaporous state locally at the anode catalyst phase, but in a liquid state at other locations of the anode side. The needed heat comes primarily from the inherent electrode reactions. This feature will allow an intrinsically controlled LVFC to enjoy the same advantages (3) and (4) cited above for the extrinsically controlled LVFC, but without having to implement a temperature sensor, heater, and temperature controlling circuit.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 A cross sectional view showing the components of a prior-art fuel cell that operates on fuel vapor.
[0021] FIG. 2 A cross sectional view showing the structure of the components of a fuel cell containing anode catalysts that operate locally on a fuel vapor or vapor-liquid mixture.
[0022] FIG. 3 A perspective view showing the components of the fuel cell of the present invention.
[0023] FIG. 4 A cross sectional view showing the structure of the components of a fuel cell wherein the anode contains a heating element to help vaporize the fuel.
[0024] FIG. 5 The voltage-current responses of two fuel cells.
DETAILED DESCRIPTION OF THE INVENTION
[0025] In order to best illustrate the features and advantages of the presently invented fuel cells, relevant prior-art fuel cells will be briefly discussed first. An example of prior-art fuel cells that operate on organic fuel vapor is presented in FIG. 1 (Tomimatsu, et al., U.S. Pat. No. 6,447,941, Sep. 10, 2002). This cross sectional view of the structure includes an electrolyte plate 1 , which is held between a fuel electrode (anode) 2 and an oxidant electrode (cathode) 3 . The electrolyte plate 1 , the anode 2 , and the cathode 3 constitute the power generating section 4 . The anode 2 and the cathode 3 are made of an electrically conductive porous material so that they allow the passage of fuel and oxidant gas as well as electrons.
[0026] This prior-art fuel cell contains a fuel-permeating layer 6 and a separate fuel evaporating layer 7 . Layer 6 introduces liquid fuel into the fuel cell by the capillary action. The fuel evaporating layer 7 is interposed between the anode 2 and the liquid fuel-permeating layer 6 .
[0027] Layer 7 evaporates the liquid fuel which is introduced into the fuel cell and feeds the fuel in the form of vapor to the anode 2 , which is another separate layer. Layers 2 , 1 , and 3 together form a 26 power-generating section 4 . Layers 3 , 1 , 2 , 7 , 6 together constitute a “unit cell”. Several of these unit cells are placed on top of another consecutively, with a separator 5 interposed between them, so that they constitute a stack 9 which is the fuel cell proper. The grooves 8 through which the oxidant gas is supplied are formed continuously in that surface of the separator 5 which is in contact with the cathode 3 .
[0028] It is clear that this prior-art fuel cell, although much simplified over other existing fuel cells, still has a relatively complex configuration and has too many layers. By contrast, we have 6 integrated the fuel-permeating layer, the fuel evaporating layer, and the anode layer into just one anode layer 12 ( FIG. 2 ). Preferably, the catalyst phase in the anode layer 12 is arranged to be in a close proximity to or in an intimate contact with the electrolyte layer 11 . The catalyst phase may be essentially a thin layer (of a nanometer thickness) at the edge of the anode layer 12 facing the electrolyte layer 11 . In such an arrangement, the reaction heat generated by the inherent electro-chemical reactions can easily reach the catalyst phase to help vaporize the fuel that has permeated to the vicinity of the catalyst. It is not necessary to vaporize all the liquid fuel that has permeated into the anode layer, only the portion close to or in contact with the catalyst (hence, the name “local vapor fuel cell”).
[0029] It may be noted that, in the aforementioned prior-art fuel cell ( FIG. 1 ), the fuel permeating layer 6 is isolated or separated from the reaction electrodes in such a distance that it cannot effectively receive the reaction heat generated by the cell reactions. The prior-art inventors also failed to recognize that a fuel vapor-liquid mixture works nearly as well as a pure vapor in the anode reaction for proton production, which we surprisingly found to be the case. It is desirable to select the electrolyte layer thickness and other reaction conditions such that the catalyst phase is heated by the reaction heat to a temperature significantly higher than 64° C. (the boiling point of methanol) in the case of using methanol/water mixture as the liquid fuel. The local reaction temperature at the anode catalyst for the methanol fuel cell is preferably in the range of 80-150° C., but most preferably in the range of 95-130° C. Although a higher temperature is generally preferred for a higher efficiency, an excessively high local temperature can spill over to other portions of the anode, making it more difficult to maintain the fuel in other portions of the anode (than the catalyst layer area) in a liquid state.
[0030] Alternatively, one may choose to introduce a thin metal wire or conductive fiber (e.g., 24 in FIG. 4 ) into the catalyst side of the anode layer to help vaporize the liquid fuel in the vicinity of the catalyst phase ( 26 in FIG. 4 ). A small amount of current may be allowed to flow through this wire or fiber to produce joule heat. A minute temperature sensor element (e.g., a thin thermocouple wire) may be placed inside the anode to monitor the catalyst phase temperature. Temperature monitoring and control devices or circuits are well-known in the art. Such a combined heating element-sensor arrangement is advantageous in that additional heat may be supplied to vaporize more fuel on demand (e.g., when needed, more current may be supplied to the external load by vaporing the fuel at a faster rate and allowing the reactions to proceed at a higher temperature). With such an added adaptability, the fuel cell essentially becomes a smart, actively controlled power source. A simple logic circuit may be added as a part of the fuel cell voltage regulator or control circuit that is normally installed in a fuel cell for electronic device applications.
[0031] In one special fuel cell design of Tomimatsu, et al., there is a combined fuel permeating-evaporating member, which has a fuel permeating portion and a fuel evaporating portion. However, this combined layer has to be made to contain specially machined holes and are complex in configuration. This requirement makes this layer and the whole fuel cell assembly more difficult and costly to produce despite the notion that this combination makes it possible to decrease the thickness of the member, as compared with the case where each of these fuel permeating member and the fuel evaporating member are formed of individual members separately.
[0032] As a means to feed liquid fuel to the anode layer 12 from a fuel source, there is formed a liquid fuel passage 20 along at least one side of the stack 19 ( FIG. 2 ). Upon introduction into the liquid fuel passage 20 , the liquid fuel is fed to the fuel permeating material of the anode layer 12 by the capillary action from the side of the stack 19 . In order to supply liquid fuel to the fuel permeating material by the capillary action, the fuel cell is constructed such that the liquid fuel which has been introduced into the liquid fuel passage 20 comes in direct contact with the end surface of the anode layer 12 .
[0033] The separator 15 (when existing) and the anode layer 12 (including the fuel permeating material therein) are each made of an electrically conductive material so that they function as a current collector to transmit electrons generated in the fuel cell. The fuel cell in this example ( FIG. 2 ) has the separator 15 which functions also as a channel to permit the oxidant gas to flow therethrough into the cathode. The advantages of using the multi-purpose separator 15 include a size reduction and reduction in the number of parts used.
[0034] The liquid fuel passage 20 may be constructed such that the liquid fuel is introduced from a fuel source (not shown) into the fuel permeating material of the anode layer 12 by the capillary action. One way to supply liquid fuel from the fuel source to the liquid fuel passage 20 is to permit the liquid fuel to drop spontaneously by gravity and to enter the liquid fuel passage 20 . This gravitational method offers the advantage of assuring the introduction of the liquid fuel into the liquid fuel passage 20 , although it requires that the fuel source be positioned above the top of the stack 19 . Another method is to introduce the liquid fuel from the liquid fuel source by the capillary action of the liquid fuel passage 20 . This method does not require that the joint between the liquid fuel source and the liquid fuel passage 20 (or the fuel entrance of the liquid fuel passage 20 ) be arranged above the top of the stack 19 . When combined with the gravitational method, this method offers the advantage of being free to install the fuel source at any place or orientation. The liquid fuel passage 20 may be formed on one side or both sides of the stack 19 .
[0035] The fuel source described above may be made detachable from the fuel cell proper, so that the fuel cell can be run for a prolonged period of time by intermittently replenishing the fuel source. The feeding of the liquid fuel from the fuel source to the liquid fuel passage 20 may be accomplished by gravity or by pressure in the source. An alternative feeding method is to extract the liquid fuel by the capillary action of the liquid fuel passage 20 .
[0036] The structure of the fuel permeating material in the anode layer is not specifically restricted as far as it permits the liquid fuel to permeate through it by the capillary action. It may be made of a porous material, cotton, non-woven fabric, highly porous paper, or woven cloth of fibers. The fuel permeating material draws liquid fuel into it by the capillary action. For the effective use of the capillary action, the fuel-permeating porous material should be formed such that its pores are interconnected and its pores have an adequate pore diameter. The porous material may have any pore diameter which is not specifically restricted, as long as it permits the liquid fuel to be drawn into the liquid fuel passage 20 . However, the pore diameter is preferably 0.01 to 150 μm in view of the capillary action of the liquid fuel passage 20 . Furthermore, the pore volume as an index of pore continuity should preferably be 20 to 90% of the porous material. With a pore diameter smaller than 0.01 μm, it becomes difficult for liquid fuel to diffuse through the pores; this could be understood from the well-known Darcy's Law that describes the diffusion behavior of a liquid through a porous medium. With a pore diameter larger than 150 μm the porous material is poor in its capillary action. With a pore volume less than 20%, the porous material has closed pores in a higher proportion and hence is poor in its capillary action. With a pore volume fraction greater than 90%, the porous material has a higher proportion of continuous pores but is poor in strength and present difficulties in fabrication. Practically, the pore diameter should preferably be 0.5 to 100 μm and the pore volume fraction should preferably be 30 to 75%.
[0037] Liquid fuel feeding grooves 21 may be formed in the surface of the separator 15 (serving also as the channel) in contact with the fuel permeating material of the anode layer 12 , as shown in FIG. 3 . The capillary action of these grooves may be used to draw liquid fuel into the fuel permeating material also through the capillary action. In this case, the liquid fuel passage 20 should be formed such that the open ends of the liquid fuel feeding grooves 21 come into direct contact with the liquid fuel passage 20 (indicated in FIG. 2 , but not FIG. 3 ). Alternatively, it is possible to use the capillary action of the liquid fuel feeding grooves 21 in combination with the capillary action of the porous material constituting the fuel permeating material of the anode layer 12 .
[0038] It may be noted that the liquid fuel feeding grooves 21 are not specifically restricted in configuration as long as they are capable of producing an adequate capillary action. However, they should be formed such that their capillary action is smaller than that of the fuel permeating material of the anode layer. Otherwise, the liquid fuel will not be fed from the liquid fuel passage 20 to the fuel permeating material. The liquid fuel feeding grooves 21 are intended to extract liquid fuel from the liquid fuel passage 20 by their capillary action. Therefore, they should be formed such that their capillary action is greater than that of the liquid fuel passage 20 in the case where the liquid fuel is introduced from the fuel source into the liquid fuel passage 20 by its capillary action. Thus, the configuration of the liquid fuel feeding grooves 21 should be formed in accordance with the configurations of the porous material constituting the fuel permeating material of the anode layer 12 and the liquid fuel passage 20 .
[0039] The separator 15 serving also as the channel is provided with the liquid fuel feeding grooves 21 extending in the horizontal direction, as mentioned above. This construction permits the liquid fuel to be fed from the entire surface of the end of the anode 12 to the fuel permeating material inside the anode layer and also permits the liquid fuel to be fed in the lateral direction across the anode layer through the grooves 21 . This makes it possible to feed liquid fuel more smoothly from the liquid fuel passage 20 to the fuel permeating material.
[0040] In the aforementioned example, the separator 15 serving also as the channel is provided with both the oxidant gas feeding grooves 18 and the liquid fuel feeding grooves 21 . Alternatively, the anode layer 12 and the cathode 13 may be individually provided with channels. In this case, one set of channels should be separated from another set of channels by an electrically conductive plate to block the passage of gas, or the holes on the surface of at least one set of channels should be closed, so that the liquid fuel is separated from the oxidant gas. In order to decrease the number of parts used and to reduce the size of the fuel cell, it is desirable to use the separator containing both types of channels.
[0041] The examples described above are directed to a fuel cell which has the stacks 19 (each composed of a power generating section 14 ) which are placed on top of the other, with each stack separated by the separator 15 . However, the fuel cell of the present invention does not necessarily need the separator channels. In this case, the oxidant gas feeding grooves 18 may be continuous ones formed in the surface in contact with the cathode.
[0042] In another embodiment of the present invention, the fuel cell may have a liquid fuel-holding portion positioned on the anode (in contact with one of the two primary or larger-area surfaces of the anode, rather than on one end or both ends of the anode). In this case, the fuel cell comprises (a) a cathode, (b) an electrolyte plate disposed on the cathode, (c) an anode disposed on the electrolyte plate and configured to be supplied with a liquid fuel, and (d) a liquid fuel-holding portion disposed on the anode. The anode is provided with a heating environment to at least partially vaporize the liquid fuel inside the anode and the anode further comprises a catalyst phase to ionize the fuel in a vapor or vapor-liquid mixture form to produce protons. Other features and operating methods of this fuel cell are similar to those discussed earlier in other embodiments.
EXAMPLE 1
[0043] A fuel cell was prepared as follows: Graphite flakes were subjected to a ball-milling treatment to obtain fine particles of several microns in size. These fine particles were mixed with a phenolic resin to obtain a slurry mixture. Chopped carbon fibers were then mixed with the slurry mixture to prepare a composite, which was then molded at a temperature of 250° C. for one hour with a hot press and then partially carbonized first at 350° C. and then at 600° C. for approximately two hours. These treatments lead to the formation of a thin, highly porous carbon structure having an average pore diameter of 60 μm and a porosity of approximately 65%. A sheet of this carbon composite structure was coated on one side with a Pt—Ru catalyst to give an anode of 32 mm×32 mm in dimensions. A carbon cloth was coated with a platinum black catalyst to give a cathode also of 32 mm×32 mm. A polymer electrolyte membrane, poly(perfluorosulfonic acid) ionomer, was held between the anode and the cathode, with the catalyst layers in contact with the electrolyte membrane. The assembly was joined together by hot-pressing at 120° C. for 5 minutes under a pressure of 100 kg/cm 2 , to give a power generating section. The resulting assembly was held between a cathode holder and an anode holder, the former having oxidant gas feeding grooves each having a depth of 2 mm and a width of 1 mm. The obtained unit cell has a reaction area of 10 cm 2 . The fuel cell was supplied with a methanol/water mixture at an 1:1 molar ratio as a liquid fuel. The liquid fuel was introduced by the capillary action through the side of the anode. The air at 1 atm as an oxidant gas was fed into the gas channels at a flow rate of 100 mL/min so that the fuel cell generated electricity at 76° C. This fuel cell gave a current-voltage characteristic as shown in Curve A of FIG. 5 .
COMPARATIVE EXAMPLE 1
[0044] A fuel cell of the prior-art type was prepared as follows. An assembly for the power generating section was prepared in the same way as in Example 1. However, the power generating section was further combined with a fuel evaporating layer and a fuel permeating layer as shown in FIG. 1 . The fuel evaporating layer is a porous carbon plate having an average pore diameter of 100μ and a porosity of 70%. The fuel permeating layer is a porous carbon plate having an average pore diameter of 5 μm and a porosity of 40%. The liquid fuel cell thus obtained was supplied with a methanol-water mixture mixed at a 1:1 molar ratio as a liquid fuel. The liquid fuel was introduced by the capillary action through the side of the anode. The air at 1 atm as an oxidant gas was fed into the gas channels at a flow rate of 100 mL/min so that the fuel cell generated electricity at 79° C. (measured at the catalyst/electrolyte interface). This fuel cell gave a current-voltage characteristic as indicated in Curve B of FIG. 5 .
[0045] The two curves shown in FIG. 5 demonstrate that the fuel cells in both examples produce a stable output voltage until the current reaches about 5 amps. This implies that it may not be necessary to have separate liquid fuel-permeating and fuel-vaporizing layers (that would make the fuel cell more bulky, heavy and expensive). It appears that as long as the catalyst phase works primarily with a fuel vapor, the fuel cell is capable of achieving a high reactivity and low methanol cross-over (from the anode to the cathode side).
EXAMPLE 2
[0046] A series of fuel cells were prepared and operated in the same way as in Example 1, with the exception that a thin copper wire was introduced into and out of the anode at a location very close to the polymer electrolyte layer (and, hence, close to the catalyst layer). A desired amount of current was fed into this zone to vary the fuel temperature between approximately 64° C. (the boiling point of methanol) and 130° C. (30° above 100° C., the boiling point of water) while the exterior temperature was maintained at a relatively low level by blowing a cool air to the fuel cell while in operation. It was found that, in general, the higher the reaction temperature, the more stable the voltage was. A higher local temperature near the catalyst phase implies not only a higher vapor content, but also a higher electrolytic reaction rate at the anode (Reaction 1). Both factors are in favor of a more stable voltage response as a function of current by way of an increased reactivity (faster and more efficient fuel conversion) and reduced chance of fuel cross-over.
[0047] It may be noted that, although the examples given herein are based on the methanol/water mixture as the liquid fuel, the presently invented fuel cell is not limited to this particular type of fuel. The present fuel cell can operates on any organic fuel that has a high hydrogen content (e.g., ethanol and hexane) and can be fed in a liquid form into the anode through diffusion and then vaporized locally at the catalyst phase. For instance, the ethanol/water mixture can be used in the fuel cell when the catalyst zone is heated to a temperature above 78° C., up to approximately up to 130° C. with poly(perfluorosulfonic acid) being the PEM used. This upper temperature appears to be limited by the working temperature of the polymer electrolyte. With a more thermally stable polymer electrolyte membrane, such as sulfonated polyimide, the vapor fuel temperature can be pushed even higher. A temperature up to 150° C. (approximately 50 degrees above the boiling temperature of water) was found to work well.
[0048] Hence, another embodiment of the present invention is a fuel cell which comprises (A) an anode comprising a catalyst phase and receiving a liquid fuel from a liquid fuel source (with the liquid fuel having a minimum boiling point T b (min) and a maximum boiling point T b (max)); (B) an ion exchange electrolyte having a first surface adjacent to the anode; and (C) a cathode adjacent to a second surface of the electrolyte. In this fuel cell, the anode is provided with a heating environment inside the anode to ensure that the catalyst phase operates at a temperature between T b (min) and approximately [T b (max)+50 degrees C.] to ionize the fuel to produce ions that move across the ion exchange electrolyte.
[0049] It is known that water has a boiling point of 100° C., methanol has a boiling point of approximately 64°, and ethanol has a boiling point of approximately 78.5° C. For a fuel cell fed with a mixture of water and methanol, the catalyst phase operates on methanol in a vaporous state and water in substantially liquid state if the local temperature is in the range of 64° C. and 100° C. Both methanol and water will be substantially vaporized if the catalyst temperature exceeds 100° C. It is particularly advantageous to allow the catalyst phase to operate at a local temperature of slightly higher than 100° C., but preferably not higher than 130° C. with an ion exchange electrolyte comprising poly(perfluorosulfonic acid) as the primary ion-conducting medium. For the ethanol/water mixture, the catalyst operating temperature is in the range of 78° C. and 150° C., but preferably in the range of 100° C. and 130° C. For a three-component mixture (water+methanol+ethanol), the catalyst operating temperature is in the range of 64° C. and 150° C., preferably in the range of 78° C. and 130° C., but most preferably between 100° C. and 130° C.
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A local vapor fuel cell, comprising (A) an anode receiving a liquid fuel from a liquid fuel source substantially through diffusion; (B) an electrolyte plate having a first surface adjacent to the anode; and (C) a cathode adjacent to a second surface of the electrolyte plate and opposite to the anode. The anode is provided with a heating environment to at least partially vaporize the liquid fuel inside the anode and the anode further comprises a catalyst phase to ionize the fuel in a vapor or vapor-liquid mixture form to produce protons. The electro-catalytic reaction at the anode is more efficient with a vapor phase or vapor-liquid mixture than with liquid fuel alone. The invented fuel cell is compact in size and light in weight and, hence, is particularly useful for powering small microelectronic devices such as a notebook computer, a personal digital assistant, a mobile phone, and a digital camera.
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CROSS REFERENCE TO RELATED APPLICATION
This is a continuation of U.S. patent application Ser. No. 09/821,920, filed Mar. 30, 2001, entitled “Method and Apparatus for Installing and Upgrading an Application in a Computer System”, now issued as U.S. Pat. No. 7,458,074, which is herein incorporated by reference. This application claims priority under 35 U.S.C. §120 of U.S. patent application Ser. No. 09/821,920, filed Mar. 30, 2001, now issued as U.S. Pat. No. 7,458,074.
FIELD OF THE INVENTION
The present invention generally relates to methods of installing, configuring, and upgrading programs within a computer system, and application programs for facilitating these methods. More particularly, the present invention relates to a simpler method of installing, upgrading, and configuring databases using an instruction processing program.
BACKGROUND OF THE INVENTION
The development of the Electronic Discrete Variable Automatic Computer (EDVAC) computer system of 1948 is often cited as the beginning of the computer era. Since that time, computer systems have evolved into extremely complicated devices. To be sure, today's computers are more sophisticated than early systems such as the EDVAC. Fundamentally speaking, though, the most basic requirements levied upon computer systems have not changed. Now, as in the past, a computer system's job is to access, manipulate, and store information. This fact is true regardless of the type or vintage of computer system.
Many large organizations own thousands of individual computers, which are located throughout the organization's facilities. Each individual computer manipulates information by following a detailed set of instructions, commonly called a “program” or “software.” These programs frequently require changes (“updates,” “upgrades,” or “fixes”) to correct errors (“bugs”) in the program and to add new functionality. That is, users frequently want to change the particular set of instructions to be performed by the computer to add new features and to fix bugs.
One problem with conventional upgrading techniques is that each upgrade must be performed on each copy of the program. Thus, if a business has 2000 copies of a particular piece of software, each upgrade procedure must be performed 2000 times. This can require a substantial investment of time. This problem is compounded because, as software systems have increased in complexity, the level of experience and the time required to perform each upgrade has also increased. Today, even relatively simple changes to the programs can require large amounts of time by highly skilled employees.
Organizations also need to add (“install”) new software programs onto their existing computers from time to time. Like conventional upgrade methods, conventional software installation methods often required that a highly technically sophisticated employee physically go to each computer and add the new software. Again, for a large organization, this consumes substantial resources.
One partial solution to these problems required the developer of a particular piece of software to create an external application that upgrades the primary software. This new “installation program” is then distributed to each end user and executed. However, these programs are difficult to create, and as a result, divert scarce development resources away from the primary software program. Installation programs are also relatively large, which can significantly increase the computer resources necessary to perform the upgrade.
Accordingly, a need exists for a simpler method for installing and upgrading software on a computer system.
SUMMARY OF THE INVENTION
The present invention uses simple data objects that allow the computer system to upgrade itself, requesting user input only when needed. These data objects can be created quickly and are easily modified to suit each individual installation. They can also provide the ability to remotely track the progress of an installation by maintaining start and completion times as properties of themselves. In addition, each upgrade object can include prerequisite information, which allows the upgrade to be performed by independent processes if the prerequisites have been completed.
One aspect of the present invention is a method of upgrading a computer program on a computer system, the computer system including an instruction processing program. One embodiment of this method comprises receiving an upgrade object associated with the computer program, the upgrade object including an instruction set adapted for use by the instruction processing program, and executing the instruction set with the instruction processing program. Another embodiment of this method comprises creating an upgrade object associated with the computer program, the upgrade object including an instruction set adapted for use by the instruction processing program; transmitting the upgrade object to the computer system; and instructing an end user to execute the instruction set with the instruction processing program.
Another aspect of the present invention is a method of installing a computer program on a computer system, the computer system including an instruction processing program. One embodiment of this method comprises receiving an installation object associated with the computer program, the installation object including an instruction set adapted for use by the instruction processing program, and executing the instruction set with the instruction processing program. Another embodiment of this method comprises creating an installation object associated with the computer program, the installation object including an instruction set adapted for use by the instruction processing program; transmitting the installation object to the computer system; and instructing an end user to execute the instruction set with the instruction processing program.
Still another aspect of the present invention is a computer program product, one embodiment of which comprises an upgrade object configured to upgrade a software program on a computer system having an instruction processing program, the upgrade object including an instruction set capable of causing the instruction processing program to perform one or more upgrade tasks, and a signal bearing media bearing the upgrade object.
One feature and advantage of the present invention is that it allows end users to install and upgrade software with minimal intervention and with little required expertise. The present invention also allows software developers to create and distribute upgrades quicker and easier. These and other features, aspects, and advantages will become better understood with reference to the following description, appended claims, and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of a computer system.
FIG. 2 is a diagram showing one upgrade object embodiment.
FIG. 3 is a flowchart depicting one embodiment of the present invention adapted for use in upgrading a database in the Lotus® Notes® program.
DETAILED DESCRIPTION
FIG. 1 depicts a computer 100 embodiment having a processor 110 connected to a main memory 120 , a mass storage interface 130 , an I/O interface 140 , and a network interface 145 via a system bus 160 . The mass storage interface 130 connects one or more mass storage devices 155 , such as a hard disk drive, to the system bus 160 . The input/output (“I/O”) interface 140 connects one or more input/output devices 165 , such as a keyboard, to the system bus 160 . The network interface 150 connects the computer 100 to other computers 100 (not shown) over an appropriate communication medium 170 , such as the Internet. The memory 120 contains an operating system 175 , a program to be upgraded 180 , a communication program 185 , and a script processing program 190 .
FIG. 2 shows one embodiment of an upgrade object 200 . This upgrade object 200 comprises a release field 210 , a control information field 220 , a description field 230 , and step code field 240 . The control information field 220 comprises a title field 233 , a step number field 224 , a prerequisites field 226 , a concurrent step field 228 , and a release field 229 . The description field 230 includes a human readable explanation 235 of what the actions that upgrade object 200 will perform. The step code field 240 comprises a plurality of instructions 242 (“script”) in text format, which are capable of being converted into a machine-useable form (“compiled”) and executed by the script processing program 190 ( FIG. 1 ).
In operation, the present invention provides a method of installing, upgrading, and maintaining software in which the end user has a very small role in the total picture. In the embodiment shown in FIGS. 1-2 , a system administrator will first install (or instruct the end users to install) the program to be upgraded 180 , the communications program 185 , the script processing program 190 onto each individual computer 100 . These programs may be installed using conventional methods, such as using a special purpose installation program stored on a suitable storage medium.
When the system administrator determines that it is necessary to upgrade the program 180 , the system administrator will prepare a group of upgrade objects 200 and will send the objects 200 to the end user. Each upgrade object 200 contains a logically related group of tasks, some of which may require user interaction and some of which may be entirely automatic. A typical upgrade will use between three and ten upgrade objects 200 .
In response to receiving the upgrade objects 200 , the end user will instruct the script processing program 190 residing on his computer to begin compiling and executing the instructions contained in the first upgrade object's step code field 240 . The script processing program 190 will then check to make sure any necessary prerequisites have been met and will begin to execute the instructions contained in the step code field 240 , prompting the end user as needed. After completing the instructions in the first object 200 , the script processing program 190 will record that the particular upgrade object 200 was successfully completed and will report this information back to the system administrator. The script processing program 190 will then repeat these actions on the next upgrade object 200 , until all of the upgrade objects 200 associated with the upgrade have been completed.
The communications program 185 can be any device capable of receiving the upgrade objects from the system administrator and providing the script instructions 242 to the script processing program 190 . Suitable programs include, but are not limited to, electronic mail programs and file transfer protocol programs. Electronic mail programs may be particularly desirable because the system administrator may initiate the upgrade process shown in FIG. 3 by simply mailing the upgrade objects 200 to the end user.
The script processing program 190 may be any apparatus capable of reading the script instructions 242 and causing the computer 100 to perform the corresponding tasks. In many embodiments, the scripting program will compile the script instructions 242 into the preferred form for the particular computer 100 that receives the object. One suitable script processing program 190 is the Lotus® Notes® program produced by Lotus Development Corporation of Cambridge, Mass. This program is desirable because it provides electronic mail functions, allows end users to compile and execute scripts sent via electronic mail, and is already fully developed. Thus, the system administrator does not need to develop and install special purpose scripting and communication software to practice the invention.
In this embodiment, the release field 210 will contain a release value. Each object 200 in the upgrade package will share a common release value. This release value can be an explicit property, like a text field with specific value, or it can be implied by some other mechanism, such as being distributed with a group of instructions. The step number field in this embodiment contains a sequence number. Like the release value, the sequence number can be an explicit field like a number field, or can be implied by some other method. The prerequisites in the prerequisites field 226 list what previous upgrades must have been performed and/or what hardware or software is required to perform the upgrade. Those skilled in the art will recognize that these prerequisites may frequently implied from and/or duplicative of the sequence number 204 . However, some embodiments may use the prerequisites to allow some steps to be run out of order. These embodiments may be particularly desirable if one of the steps in the upgrade requires the computer 100 to access a particular outside resource.
Some upgrade object 200 embodiments may also include a start time field and an end time field, (not shown). These fields may be desirable for use in managing the instruction set. Some object embodiments may also contain an instruction type field (not shown). This field may be desirable to distinguish between instructions that require user action and instructions that may be performed entirely automatically. Those skilled in the art will recognize that this information by also be implied by the contents of the script.
FIG. 3 is a flowchart depicting one embodiment of the present invention adapted for use in upgrading a Lotus® Notes® program database called “Pipeline.” At block 300 , the system administrator and/or the end user will install the communication program 185 and script processing program 190 on the end user's computer 100 . When the system administrator determines that the end user's computer needs upgrading or additional software, the system administrator sends a group of installation objects to the end user at block 301 . Also at block 301 , the end user will initiate the “AutoInstall” function. This function is contained within the existing script processing program, and will cause it to begin compiling and executing the script. In the specific embodiment shown in FIG. 3 , the AutoInstall function is an action either in a Lotus® Notes® program view or document.
At block 302 , the AutoInstall function will locate the first data object in the instruction set, which in this specific embodiment is a simple Lotus® Notes® document. Before continuing with the Lotus® Notes® object, it is determined at block 303 whether the object has already been started elsewhere. If the object has been started, the end user chooses (at block 304 ) whether to skip this object and continue to the next object (i.e., return to block 302 ), or to repeat this block. If the instruction has not previously been started or the user has decided to repeat it, the object is then checked at block 305 to be sure the prerequisites have been met. If the prerequisites have not been met, the installation fails and the system administrator is notified at block 306 . If the prerequisites have been met, the object is time-stamped and the type of instruction is determined at block 307 . If it is a manual instruction, the text of the instruction is presented to the end user at block 308 . If it is an automatic instruction, the text of the instruction is interpreted and executed at block 309 . In this embodiment, the LotusScript® EXECUTE statement is used to accomplish this block. Once the instruction has been completed, the instruction is time-stamped at block 310 , then checked to see if it is the last instruction. If it is the last instruction, the user is notified at block 312 of a successful installation and the function terminates. If it is not the last block, the process is continued on the next instruction object at block 302 .
Referring again to FIG. 1 , the processor 110 in the computer 100 may be constructed from one or more microprocessors and/or integrated circuits. Processor 110 executes program instructions stored in main memory 120 . Main memory 120 stores programs and data that the processor 110 may access. When computer 100 starts up, the processor 110 initially executes the program instructions that make up the operating system 124 . The operating system 175 is a sophisticated program that manages the resources of the computer 100 . Some of these resources are the processor 110 , the main memory 120 , the mass storage interface 130 , the input/output interface 140 , the network interface 150 , and the system bus 160 .
The I/O interface 140 directly connects the system bus 160 to one or more I/O devices 165 , such as a keyboard, mouse, or cathode ray tube. Note, however, that while the I/O interface 140 is provided to support communication with one or more I/O devices 165 , some computer 100 embodiments do not require an I/O device 165 because all needed interaction with other computers 100 occurs via network interface 150 .
Although the computer 100 is shown to contain only a single processor 110 and a single system bus 160 , those skilled in the art will appreciate that the computer 100 may have multiple processors 110 and/or multiple buses 160 . In addition, the interfaces may also each include a separate, fully programmed microprocessor. These embodiments may be desirable because the interface processors can off-load compute-intensive processing from processor 110 . However, those skilled in the art will appreciate that the present invention applies equally to computers 100 that simply use I/O adapters to perform similar functions.
The network interface 150 is used in this embodiment to connect other computers and/or devices to the computer 100 across a network 170 . The present invention applies equally no matter how the computer 100 may be connected to other computers and/or devices, regardless of whether the network connection 170 is made using present-day analog and/or digital techniques or via some networking mechanism of the future. In addition, many different network protocols can be used to implement the communication between the computers and/or devices. One suitable network protocol is the Transmission Control Protocol/Internet Protocol (“TCP/IP”).
The mass storage interface 130 in this embodiment directly connects the system bus 160 to one or more mass storage devices 155 . The mass storage devices 155 , in turn, may be any apparatus capable of storing information on and/or retrieving information from a mass storage medium 195 . Suitable mass storage devices 155 and mediums 155 include, without limitation, hard disk drives, CD-ROM disks and drives, DVD disks and drives, tapes and tape drives. Additionally, although the mass storage device 155 is shown directly connected to the system bus 160 , embodiments in which the mass storage device 155 is located remote from the computer 100 are also within the scope of the present invention.
Although the present invention has been described in detail with reference to certain examples thereof, it may be also embodied in other specific forms without departing from the essential spirit or attributes thereof. For example, the present invention may be used to install new programs onto the computer 100 and/or to delete unnecessary programs from the computer 100 . It may also be used to initiate periodic maintenance tasks, such as defragmenting the hard disk drive, scanning the computer 100 for computer viruses, backing up data, and the like. The present invention, and components thereof, are also capable of being distributed as a program product in a variety of forms, and applies equally regardless of the particular type of signal bearing media used to actually carry out the distribution. Examples of suitable signal bearing media include, without limitation: recordable type media, such as floppy disks and CD-RW disks, CD-ROM, DVD, and transmission type media, such as digital and analog communications links. In addition, some embodiments may replace or supplement the text script 242 in FIG. 2 with binary code. These embodiments may be desirable because they may require fewer resources from the end user's computer.
The present invention offers numerous advantages over conventional installation and upgrade methods. For example, the end user will only need to perform actions for one or two steps in the typical process. This allows relatively inexperienced end users to perform the upgrade and/or installation, rather than more experienced system administrators. Embodiments of the present invention also provide for automatic reporting and user interaction if an error occurs during the upgrade process. These embodiments may be desirable because they provide the system administrator with a detailed list of which upgrades have been installed on each computer and, in the case of an error, at what step in the upgrade process the error occurred. This information can help the system administrator diagnose what caused the error. In addition, embodiments of the present invention allow the system administrator to use functionality already present on the end user's computer 100 , which decreases the effort required to prepare the upgrade objects and reduces the size of the resulting objects. That is, because the upgrade objects 200 in these embodiments use functionality present in the script processing program 190 , the upgrade object 200 can be smaller and simpler than the installation programs used in the prior art. This feature also allows the system administrator to create generic upgrade objects 200 and to rely upon the script processing program 190 to customize the resulting upgrade for the end user's computer 100 .
The accompanying figures and this description depicted and described embodiments of the present invention, and features and components thereof. It is desired that the embodiments described herein be considered in all respects as illustrative, not restrictive, and that reference be made to the appended claims for determining the scope of the invention.
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A method of distributing and executing upgrade/installation instructions as data objects. These instructions can then be completed automatically requesting user interaction only when required. This method would allow someone with little knowledge of the application and/or internal implementation of said application to perform an upgrade to the application.
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RELATED APPLICATIONS
[0001] This application is related to the following co-pending U.S. Patent Applications filed on the same day as the present application and having the same assignee: “On-Chip Adaptive Voltage Compensation,” (Docket No. RPS9 2006 0231 US1); “Using Temperature Data for Instruction Thread Direction,” (Docket No. RPS9 2006 0263 US1); “Using Performance Data for Instruction Thread Direction,” (Docket No. RPS9 2006 0262 US1); “Using IR Drop Data for Instruction Thread Direction,” (Docket No. RPS9 2006 0261 US1); “Integrated Circuit Failure Prediction,” (Docket No. RPS9 2006 0260 US1); “Instruction Dependent Dynamic Voltage Compensation,” (Docket No. RPS9 2006 0259 US1); “Temperature Dependent Voltage Source Compensation,” (Docket No. RPS9 2006 0258 US1); and “Digital Adaptive Voltage Supply,” (Docket No. RPS9 2006 0256 US1); each assigned to the IBM Corporation and herein incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Technical Field
[0003] The present invention relates in general to a system and method for regulating cooling of integrated circuits. In particular, the present invention relates to a system and method for regulating fan speed based on measured temperatures of integrated circuit.
[0004] 2. Description of the Related Art
[0005] Integrated circuits require heat dissipation or cooling. Some integrated systems provide cooling by merely allowing the integrated circuit generated heat to dissipate in the surrounding atmosphere or by aid of heat sinks. Other cases require external devices to provide cooling assistance. Commonly, integrated circuits are mounted on printed circuit boards that are contained within a chassis having a fan mounted to providing airflow through the chassis, in order to cool the integrated circuits.
[0006] Present practice is to provide a single speed fan in a chassis. However, as integrated circuits advance in technology and clock frequency increases, cooling becomes more of a concern. Therefore, in some systems, variable speed fans have been provided. A typical way to implement the cooling with a variable speed fan is to connect a veritable speed fan to a thermostat, which measures the air temperature inside of a chassis. Based on the ambient air temperature, the fan speed can be adjusted to provide cooling.
[0007] However, the ambient air temperature is not the best measure of the heat of a specific integrated circuit sense. A computer system contains several integrated circuits. Each integrated circuit has its own heat that needs to be dissipated. Certain integrated circuits, such as central processing units or CPUs, require a greater amount of cooling than other integrated circuits in the system. Again, it is not uncommon to provide these CPU integrated circuits with heat sinks or even a fan mounted on the integrated circuit. Thermal diodes have been used in chips to measure junction temperature of provide signals for fan speed control. Some integrated circuits provide a digital output of the temperature signal for controlling fans. However, a need exists to provide a more flexible control of cooling based upon temperature data obtained on the integrated circuit devices.
SUMMARY
[0008] In accordance with the present invention, a method for controlling the speed of a cooling fan provided to cool an integrated circuit in which includes the steps of receiving a voltage from a thermal diode, addressing a table of digital temperatures by incrementing the address of the table entries every clock cycle of a circuit clock, converting the addressed data to a second voltage representing temperature, comparing the first voltage, but the second voltage, providing a resulting temperature when both the first and second voltages are equal, and adjusting the fan speed accordingly.
[0009] In one embodiment of the present invention, a method for controlling fan speed, including the steps of measuring temperature using several thermal diodes located upon the surface of a single integrated circuit, and determining if the measured temperatures are with and a predetermined temperature range, where the average of the temperatures is used to control the fan speed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The present invention may be better understood, and its numerous objects, features, and advantages made apparent to those skilled in the art by referencing the accompanying drawings.
[0011] FIG. 1 is a schematic diagram of a simple embodiment of the temperature measurement circuit;
[0012] FIG. 2 is a schematic diagram of a second embodiment of the temperature measurement circuit;
[0013] FIG. 3 is a schematic diagram of the two ring oscillator circuit that provides input for the frequency response measurement and provides the IR drop measurement;
[0014] FIG. 4 is a schematic diagram of the preferred embodiment of the adaptive voltage compensation circuit;
[0015] FIG. 5 is a flow chart representing the operation of the adaptive voltage compensation circuit;
[0016] FIG. 6 is a block diagram of an adaptive voltage supply system connected to a fan speed controller and a fan;
[0017] FIG. 7 is a diagram illustrating a single integrated circuit containing several cores that each included adapter power supply; and
[0018] FIG. 8 as a flow chart detailing the procedure executed by the fan speed controller.
DETAILED DESCRIPTION
[0019] The following is intended to provide a detailed description of an example of the invention and should not be taken to be limiting of the invention itself. Rather, any number of variations may fall within the scope of the invention, which is defined in the claims following the description.
[0020] The present invention provides a cooling mechanism including a fan speed controller that operates off of data obtained from an adaptive voltage system. The adaptive voltage system is contained upon the integrated circuit surface itself. In one embodiment of the invention, individual and adaptive voltage systems are contained within each core of a Baltic or integrated circuit. A common application would provide an integrated circuit having multiple CPUs, where each CPU is a core. Each of the adaptive voltage systems contained within each core would provide an input to a fan speed controller that would be connected to a fan to provide cooling for the computer system or for the individual integrated circuit itself.
[0021] What follows is a discussion of the adaptive voltage supply, followed by an explanation of how data obtained from the adaptive voltage supply is used to regulate cooling. In the preferred embodiment of the adaptive voltage supply, three physical condition measurements are made. The first is temperature, which is measured by a thermal diode on the surface of the integrated circuit. The second is the IR (voltage) drop measured by two ring oscillator circuits and the third is the frequency performance of the integrated circuit measured by a single loop oscillator compared to stored predetermined performance values.
[0022] The complete control signal provided to the voltage regulation circuit is:
[0000] Total Vdd scaling=Frequency response scaling+Temperature related Vdd scaling+IR drop related scaling
[0023] All of the measurement circuits are contained on the surface of this integrated circuit device in the preferred embodiment. These measurements are then used to scale an input control signal to a voltage regulation circuit also contained on the surface of the integrated circuit device or alternatively on another integrated circuit. The output of this voltage regulation device provides the integrated circuit operating voltage (chip Vdd). Thus the voltage supplied to the integrated circuit can be adjusted to either save power or increase performance dynamically during the operation of the chip by under program control. Further the integrated circuit voltage and, therefore, performance can be changed in anticipation of operating environment changes such as a sleep state or the execution of instructions requiring higher circuit performance.
[0024] This is a dynamic method of varying voltage that takes into account the specifics of the semiconductor manufacturing process, temperature and IR drop effects simultaneously. This method uses available on-chip data to compute adjustment in voltage necessary to either meet target performance or decrease power consumption. The two goals are met using the same circuit. Another advantage of using this method is the flexibility it offers to the users in terms of programmability. On chip voltage can be artificially varied by writing into special registers which provide values used by the power management circuitry to provide the supply voltage Vdd. This feature can be helpful when expecting instructions that require high circuit performance, essentially providing an “on-Demand” performance capability. In other words, to provide on request, additional circuit supply voltage to increase circuit performance.
[0025] This method is not limited to a specific technology or type of circuit. It can be applied to a broad type of integrated circuits, especially those that need to deliver higher performance at lower power consumption.
[0026] This method also offers reduction in test time for identifying yield and voltage per module. It is a dynamic solution unlike previous static solutions (fuses, etc) that takes into account effects of IR drop.
[0027] FIG. 1 is a schematic diagram of one embodiment of the thermal measurement circuit 125 shown connected to the voltage regulation circuit which provides the integrated circuit voltage source (Chip Vdd). This measurement circuit includes a current source 100 connected to the voltage source. This current source 100 is also connected by a line 103 to a thermal diode 102 also connected to ground. The voltage across the thermal diode 102 indicates the measured temperature of this integrated circuit. This thermal voltage signal is provided over line 103 to an analog comparator 106 . The output of the comparator 106 is connected to an address counter 110 providing an address to a digital to analog (D to A) converter 114 . The operating range for a thermal diode is commonly zero to 125° C. The address counter 110 includes a look up table with 128 entries. These entries correspond to 0 to 127 degrees C. Initially, the address counter 110 starts at zero degrees and increments upward each clock cycle. Each address is provided to the D to A converter 114 over line 112 . In operation, the analog comparator 106 compares the output of the D to A converter 114 with the measured thermal voltage provided by the thermal diode 102 . When the address counter 110 provides an output representing the same temperature as the thermal diode 102 , the output voltage from the D to A converter 110 will be the same voltage as that provided by the thermal diode 102 . The output of the analog comparator 106 will then be zero. The address counter 110 will then stop incrementing and provide a signal over line 116 to a delay lookup table (LUT) circuit 118 . This value on line 116 is a digital signal representing the temperature measured by the thermal diode 102 . This thermal voltage value is used to address a corresponding delay value in the delay lookup table circuit 118 . The delay lookup table in circuit 118 is a table of pulse width values computed by a simulation of the performance of the integrated circuit. Each value represents the expected delay value computed for the temperature range of 0 to 127 degrees C. for expected integrated circuit performance.
[0028] To measure the process on the substrate, a ring oscillator connected to a temperature compensated voltage source (ex: a bandgap reference) is used. In this case, for a given temperature, the pulse width produced by the ring oscillator is a function of the process on the substrate since temperature and voltage are constant. By using a bandgap reference, the voltage applied to a ring oscillator can be kept constant. But the temperature of the substrate depends upon internal and external operating conditions and it cannot be held constant. To eliminate the effects of varying temperature, another scheme is used in this invention.
[0029] First, a target predicted circuit performance number (pcpn) is chosen. This number represents the expected circuit performance based on expected semiconductor manufacturing process. This number represents circuit performances expected under nominal applied voltage across the entire operating temperature range. For this pcpn, a simulation of the ring oscillator supplied by a constant voltage from a bandgap reference is carried out for the entire operating temperature range. This simulation yields pulse widths that are generated at a fixed voltage and pcpn values where only the temperature is varied across the entire operating temperature range. If the substrate pcpn is identical to the desired target performance, then the substrate would also yield identical pulse widths for each value of the operating temperature range.
[0030] If the substrate pcpn is different than the desired target performance, then the pulse widths produced by the substrate will be either shorter or longer than those produced by simulation depending upon whether the substrate pcpn was faster or slower than the desired target performance. So a comparison has to be made between the pulse width generated by the ring oscillator on the substrate with a simulated value of the pulse with at the value of the substrate temperature at a fixed voltage. The expected pulse width values at the desired target process for each temperature value within the desired operating temperature range are stored in a Look Up Table (LUT) (for example, 118 in FIG. 1 ) that is addressed by the current substrate temperature, i.e. based on the substrate temperature, the address pointer points to an entry in the LUT that contains the expected pulse width from the ring oscillator circuit at the desired process corner at a fixed bandgap voltage. For this invention, the operating temperature range is 0° C. to 127° C. and this range is divided into 128 steps of 1° C. each. This requires 128 entries in the LUT, one entry corresponding to each 1° C. rise in temperature.
[0031] This resulting pulse width value from the delay lookup table circuit 118 provides a voltage scaling signal in digital form which is converted to an analog voltage signal by D to A converter 122 . This scaling voltage signal is provided to a voltage regulator 130 over line 124 . The operation result of the circuit 125 would be to increase or decrease the resulting voltage of regulator circuit 130 (chip Vdd) based upon the measured temperature of the integrated circuit measured by thermal diode 102 .
[0032] FIG. 2 is a second embodiment of the thermal measurement circuit illustrated in FIG. 1 . The temperature measurement circuit 225 of FIG. 2 includes two current sources 200 and 202 which are selectively connected to a thermal diode 208 through a switch 204 connected by line 206 . The diode is actually made up of a lateral PNP device fabricated in CMOS technology. The collector and base of this device are shorted leaving the diode between base and emitter.
[0033] Digital temperature sensors are based on the principle that the base-emitter voltage, V BE , of a diode-connected transistor is inversely proportional to its temperature. When operated over temperature, V BE exhibits a negative temperature coefficient of approximately −2 mV/° C. In practice, the absolute value of V BE varies from transistor to transistor. To nullify this variation, the circuit would have to calibrate each individual transistor. A common solution to this problem is to compare the change in V BE of the transistor when two different current values are applied to the emitter of the transistor.
[0034] Temperature measurements are made using a diode that is fed by 2 current sources, one at a time. Typically the ratio of these current sources is 10:1. The temperature measurement requires measuring the difference in voltage across the diode produced by applying two current sources.
[0035] Line 206 is connected to a “sample and hold” circuit 209 to sample and hold a voltage output of the thermal diode 208 . The address counter circuit 222 operates identically to the address counter, circuit 110 of FIG. 1 previously discussed. Address counter circuit 222 increments an address every clock cycle which provides a digital signal representing the temperature range of zero to 127° C. over line 220 to the D to A converter 218 which converts this digital signal representing temperature to a voltage. This voltage signal is provided on line 215 to a second sample and hold circuit 213 . Both the sample of the hold circuits 209 and 213 will sample and hold their respective voltages for the comparator 212 so that continuing small variations in temperature from the thermal diode 208 will not adversely affect the operation of this temperature measurement circuit 225 . Upon reaching the measured temperature, the comparator 212 will provide a zero output over line 216 to the address counter 222 which provides a digital signal representing the measured temperature on line 224 to the delay lookup table circuit 226 . The operation of the delay lookup table circuit 226 providing a digital delay value on line 228 to the D to A converter 230 is the same as previously discussed for the measurement circuitry 125 in FIG. 1 .
[0036] FIG. 3 is a schematic diagram of the IR drop measurement circuit 325 which provides voltage scaling signal to a voltage regulator circuit 326 . A band gap voltage source 300 is connected to a ring oscillator circuit 304 . The ring oscillator circuit 304 consists of an odd number of inverters 302 connected in a loop or ring. The band gap source is obtained from the physical integrated circuit itself and is nominally 1.23 V. A second ring oscillator circuit 306 connected to the chip voltage source provides an output on line 314 . The band gap ring oscillator provides an output on line 312 . A phase detector 308 is connected to lines 312 and 314 to determine the difference or delay between the pulses provided by the two ring oscillator circuits 304 and 306 . The phase detector 308 provides a voltage magnitude output and a voltage polarity output on lines 316 and 318 respectively which in combination represent the delay difference between the ring oscillator circuits 304 and 306 . Lines 316 and 318 are input to a comparator 310 which provides a voltage scaling signal on line 322 to the voltage regulator 326 . It should be understood that this voltage scaling signal on line 322 is based solely upon the IR drop of the integrated circuit. Based on the voltage scaling signal of line 322 , voltage regulator 326 provides the appropriate chip Vdd value. In the preferred embodiment, the two ring oscillator circuits 304 and 306 should be located in close proximity to each other so that the effects of any irregularities across the surface of the integrated circuit will be minimized.
[0037] The frequency response of the integrated circuit (or performance of the integrated circuit) can be measured by using the output of a band gap voltage connected ring oscillator 304 on line 305 of FIG. 3 and the lookup table containing known delay values based on chip temperature from circuit 226 or FIG. 2 . This is illustrated in combination with the IR drop measurement of circuit 325 and the temperature measurement of circuit 225 in FIG. 4 . In the IR drop measurement circuit 325 , the band gap connected ring oscillator 304 provides a second signal connected to an integrator circuit 414 , which takes the pulse signal from the band gap connected ring oscillator 304 of circuit 325 and converts it into a voltage which is then provided to difference circuit 416 . Another input line 415 to the difference circuit 416 is compared to the delay voltage signal output from the D to A converter 230 representing the expected delay based on the measured temperature. The output of this difference circuit 416 represents a voltage indicative of the integrated circuit frequency response or performance of the integrated circuit. More specifically, this signal provided to multiplexer 418 represents the actual integrated circuit performance compared to the expected integrated circuit performance for that temperature. If the expected delay signal on line 415 is less than the delay signal from integrator circuit 414 , the chip is performing below expectations and the voltage Vdd should be increased. Conversely, if the expected delay on line 415 is greater than the delay signal from integrator circuit 414 , the chip is performing above expectations and the voltage Vdd could be lowered to save power.
[0038] FIG. 4 also illustrates the preferred embodiment of the invention combining the temperature measurement circuit 325 output, the IR drop measurement circuit 325 output with the frequency response measurement as discussed above. In this embodiment, the temperature measurement circuit includes a lookup table address register 400 connected to the address counter 210 by line 402 to provide an initial address or to provide an artificially changed temperature that would result in an artificially changed voltage scaling signal. Also, the lookup table data register 406 is provided that may provide a directed input into the delay lookup table 226 . This can be used to provide entries into the delay lookup table or provide bypass data output directly to multiplexer 410 which is input to the D to A converter 230 . In this manner, a programmer could directly control the delay value, which is used to compute the voltage scaling signal on line 428 . The output of the D to A converter 230 is provided on line 415 directly to the difference circuit 416 and to the multiplexer 418 . In this manner the multiplexer 418 may bypass the difference circuit 416 and only provide the temperature dependant table delay value to the driver 420 . The driver 420 is connected to a register 408 by line 438 which can be used to control the amount of signal output on line 424 to the summing circuit 426 . Likewise, in circuit 325 , register 432 provides on line 434 , a signal that can be used to vary the amount of the scaling signal output from the circuit 325 to the summing circuit 426 . The output from summing circuit 426 is the voltage scaling signal on line 428 and is provided to the voltage regulator 436 which in turn provides the integrated circuit voltage (chip Vdd) 440 .
[0039] FIG. 5 is a process flow chart representing the operation of the invention. It is important understand, that FIG. 5 is not a flow chart representing software execution but of a simultaneous process producing the voltage scaling signal previously discussed in the operation of the different functional units of the present invention. The discussion of this flowchart of FIG. 5 will also reference FIGS. 2 , 3 and 4 respectively. In the start phase 500 , path 524 illustrates the simultaneous operation of the different aspects of this invention. In step 502 , the thermal diode 208 provides an output voltage indicating the measured circuit temperature on line 506 to process block 504 . Process block 504 represents the operation of the address counter 222 , the D to A converter 218 and the voltage comparator 212 (of FIG. 2 ) in determining a digital signal representative of the circuit temperature as previously discussed. Referring to FIG. 5 , this digital temperature is provided on path 530 to the delay lookup table in step 506 which provides a digital signal representative of the delay on path 534 to the D to A conversion step 508 resulting in the delay signal voltage provided to the comparator 514 over path 536 .
[0040] Returning to path 524 , the frequency response value measured in block 510 is provided in path 528 to both the integration block 512 and to the compare block 520 by line 538 as discussed in FIG. 4 . The integration circuit 414 of FIG. 4 provides the frequency response measurement signal to the compare block 514 over path 542 which is then compared to the delay signal on path 536 . This result of this comparison is provided on path 544 . Returning to path 524 , the measurement of the IR drop from the ring oscillator 306 connected to the chip voltage supply is compared with the ring oscillator 304 connected to the bandgap voltage source in step 520 . The output on path 540 represents the IR drop portion of the voltage scaling signal and is combined in step 516 to produce the overall voltage scaling signal 546 provided to the regulator 436 in step 522 . It is important understand that this voltage scaling signal results from the combination of the measurements for temperature, IR drop and circuit frequency response.
[0041] Regulation of fan speed by data from the adaptive voltage supply
[0042] FIG. 6 is a block diagram of an adaptive voltage supply. That includes an adaptive power management unit (PMU) 622 , a fan speed controller 628 connected by line 626 to a fan 624 . In FIG. 6 , the temperature sensor, 604 is similar to the temperature sensing circuit of FIG. 2 , which includes the data provided to a pulse width table 608 from line 606 . The pulse width table 608 is similar to the delay lookup tables 226 of FIG. 2 . In the embodiment shown in FIG. 6 , the pulse width table is connected by line 620 to a data register 610 which provides data to and from the pulse width table 608 , to the PMU 622 by line 690 and to the fan speed controller 628 by line 630 . As discussed in FIG. 4 , the data register 610 provides data on line 620 to multiplexer 612 as does the pulse width table 608 through line 664 . The output of the multiplexer 612 is provided on line 614 to the D to A converter 618 as previously discussed in FIG. 4 . As was discussed in FIG. 3 , FIG. 6 also includes a bandgap reference circuit 618 and chip Vdd reference circuit 632 . The D to A converter 618 provides the expected pulse width data to the difference circuit 665 which also receives the bandgap reference pulse width from the bandgap reference circuitry 618 provided on line 644 . This difference signal is provided on line 667 to the driver 672 . In the embodiment shown in FIG. 6 , a process weight register 668 is included to provide a weight value on line 670 to the driver 672 to either increase or decrease the effect of this measured difference the two pulse widths. Register 668 is also connected to the PMU 622 . The bandgap reference circuit 618 is also connected to a difference circuit 642 on line 644 along with the chip Vdd reference signal from circuit 632 connected by line 634 . This signal, as previously discussed, is provided on line 642 to driver 638 and represents the IR drop value. Similarly to register 668 , a register 636 is provided that contains a weighting efficient to either increase or decrease the effect of the IR drop value in the control of the voltage supply output. This register 636 is connected to the driver 638 by line 648 . Additionally, register 636 is connected to the PMU 622 by line 684 . Returning to driver 672 , the output of this driver 672 on line 674 is provided to a summing circuit 654 and to a process sensor register 676 . The process sensor register 676 stores the data representing the process performance data and is provided on line 682 the PMU 622 .
[0043] The summing circuit, 654 also receives the IR drop data from driver 638 on line 652 and the output of the summing circuit 654 is provided on line 650 to a driver 658 which is also connected by line 661 to a regulator register 660 having a coefficient providing how much influence this circuit will provide to voltage supply output or Vdd provided to the overall integrated circuit or integrated circuit core. This weight register 660 provides a connection on line 682 to the PMU 622 .
[0044] However for the purposes of fan speed control, only the data that is present in the data register 610 is needed from the adaptive voltage supply circuit of FIG. 6 .
[0045] FIG. 7 illustrates another embodiment of the present invention, where a single integrated circuit device 700 includes several cores such as 702 , 704 , 706 and 708 . Commonly, the cores would be central processing unit CPU cores. In the embodiment shown, core 704 has been exploded in the diagram to core 710 and includes an adaptive power supply circuit 712 . In one embodiment, each of the cores of the integrated circuit 700 would also include individual adaptive power supply circuits per core. Therefore, each adaptive power supply for each core would provide temperature values to the fan speed controller 716 even though only a single temperature line from adaptive power supply 712 is shown on line 714 . In this manner, the fan speed controller can regulate the fan speed and thus the cooling for the integrated circuit by individual measurements of core temperatures for each core. The fan speed controller then regulates the fan speed based on the collective and/or individual core temperatures.
[0046] FIG. 8 is a flow chart representing the procedure executed with on the fan speed controller previously discussed. The process is started at 800 and progresses through line 802 to start a timer 804 . The operation of the timer is to allow periodic adjustments to the fan speed. In one embodiment, the timer resets every 1000 clock cycles of the CPU. Once the timer is started, the process continues on line 806 to a decision 808 to determine if the temperature measured from the adaptive power supply or supplies are below a minimum temperature value. If yes, this procedure continues on line 810 to block 824 where the fan is turned off or alternatively, set to a low fan speed. The procedure continues on line 826 .
[0047] Returning to decision 808 , if the measured temperature is not below a minimum temperature, the process continues on line 812 to decision 814 to determine if the temperature is below a high temperature value. If so, the process continues on line 822 to block 828 where multiple core temperature values are examined and the core temperature values below the minimum temperature of decision 808 are discarded. The procedure continues on line 830 to block 832 where the remaining core temperatures are averaged. The procedure continues on line 834 to block 836 where the fan speed is set according to the average of these remaining core temperatures. It should be understood by those skilled in the art that a simple coefficient could be multiplied by the average of core temperatures to obtain a signal value to be provided to the fan to regulate the fan speed. Upon exiting block 836 , the procedure continues on line 826 . Returning to decision 814 , if the temperature is not below the high of block 818 , the highest temperature of a any individual core is determined. The procedure continues on line 820 to block 838 where the fan speed is then set according to this highest core temperature. The procedure exits block 838 on line 826 which is connected to decision 840 . In decision 840 , it is determined whether the timer has timed out. If not, the procedure just loops back over line 842 until the timer does timeout. In this manner, a small interval of time is provided for a constant fan speed and the effect of cooling to take place. Once the timer has timed out, the process continues on line 844 back to start the timer again in block 804 .
[0048] While this discussed embodiment shows only a single voltage control circuit on the integrated circuit, it should be apparent that multiple voltage control circuits may be utilized to provide different voltages to different portions of the integrated circuit.
[0049] While particular embodiments of the present invention have been shown and described, it will be obvious to those skilled in the art that, based upon the teachings herein, that changes and modifications may be made without departing from this invention and its broader aspects. Therefore, the appended claims are to encompass within their scope all such changes and modifications as are within the true spirit and scope of this invention. Furthermore, it is to be understood that the invention is solely defined by the appended claims. It will be understood by those with skill in the art that if a specific number of an introduced claim element is intended, such intent will be explicitly recited in the claim, and in the absence of such recitation no such limitation is present. For non-limiting example, as an aid to understanding, the following appended claims contain usage of the introductory phrases “at least one” and “one or more” to introduce claim elements. However, the use of such phrases should not be construed to imply that the introduction of a claim element by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim element to inventions containing only one such element, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an”; the same holds true for the use in the claims of definite articles.
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Measurement circuit components are included in an integrated circuit fabricated on a semiconductor substrate. A method is provided for controlling the speed of a cooling fan provided to cool an integrated circuit in which includes the steps of receiving a voltage from a thermal diode, addressing a table of digital temperatures by incrementing the address of the table entries every clock cycle of a circuit clock, converting the addressed data to a second voltage representing temperature, comparing the first voltage to the second voltage, providing a resulting temperature when both the first and second voltages are equal, and adjusting the fan speed accordingly.
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This is a divisional of co-pending application Ser. No. 07/293,842 filed on Jan. 5, 1989, now U.S. Pat. No. 4,898,614, patented Feb. 6, 1990.
BACKGROUND OF THE INVENTION
This invention relates to a polish formulation including a zwitterionic aminofunctional siloxane which imparts to the surface containing the polish a film forming capacity which functions to sheet water coming into contact with the surface rather than to bead the water as has been the case with prior formulations.
Polishes are used to produce a glossy finish on a surface as well as to prolong the useful life of the surface. The gloss provided by the polish is the result of components in the polish which leave a coating and that function to smooth and clean the surface. Floor polish, furniture polish, and shoe polish, rely upon a deposited film. Car and boat polish formulations result in a glossy and protective film and contain abrasives for removing weathered paint and soil as well as old built-up polish. Metal polish contains ingredients for abrasive smoothing of the surface being treated and for surface cleaning, as well as component that function to remove and retard the build-up of tarnish.
Motor vehicle polish is formulated in order to remove road film and oxidized paint, and to provide a continuous glossy film which resists water and its removal by water and car wash detergents. Such vehicle polishes contain several major functional ingredients including an abrasive. The abrasive, however, must be mild enough to avoid scratching of the painted surface, and representative of such mild acting materials are, for example, fine grades of aluminum silicate, diatomaceous earth, and various silicas. Straight and branched chain aliphatic hydrocarbons are employed to facilitate the detergency of the polish against oil based traffic soils and debris, and provide the solvency characteristics necessary in the production of a stable formulation. These hydrocarbons also control the drying rate of the formulation. Wax constitutes another polish ingredient and is one of the two film forming materials in the polish. The wax is spread and leveled and produces a high luster following buffing of the surface. Blends of soft and hard wax are often employed in order to facilitate ease of buffing and the durability of the polish against environmental antagonists. Exemplary waxes are paraffin wax, microcrystalline petroleum wax, carnauba wax, candella vegetable wax, montan coal derived was, and synthetic polymeric waxes such as oxidized polyethylene.
Silicone materials are included in polishes as the other film forming ingredient. Such silicone materials also function as lubricants for easing the application of the polish as well as its buffing, and act as release agents for dried abrasive. The silicone materials spread easily and provide a uniform high gloss and with it water repellency. Such materials typically are dimethylsilicones, however, aminofunctional silicone products are becoming more prevalent. The aminofunctional products result in films having increased resistance to removal from the surface by detergents and the environment believed to be the result of their ability to plate out on a painted surface and to crosslink and bond to that surface.
A car polish may also contain an emulsifier, a thickener, and a stabilizer, for the production of a homogeneous stable product of desired consistency. Such polishes may be solid in form, semisolid, presoftened, or liquid. The polish, for example, can be solvent based or an emulsion, and in either case is a liquid, semi-solid or solid in construction. Typically, liquid emulsions include ten to fifteen weight percent of an abrasive, ten to thirty weight percent of solvent, two to fifteen weight percent of a silicone material, and up to about four weight percent wax. In an emulsion paste formulation, the wax ingredient is increased in level from three to twenty-five weight percent.
In U.S. Pat. No. 3,956,353, issued May 11, 1976, there is disclosed the reaction product of an aminofunctional silane and a cyclic acid anhydride. These products are limited, however, to vinyl benzyl functional amines whereas the materials of the present invention differ in the amine group, and do not require such a substitution. Such products further are not disclosed to be useable in a polish formulation as such, but are aqueous or alcohol coupling agent compositions, in contrast to the polish composition disclosed in the present invention. Polishes, it should be noted, require polymers with significant dimethyl character for solubility, as are the aminofunctional siloxane zwitterions of the present invention. The reaction products in U.S. Pat. No. 3,956,353, however, are low molecular weight monomer materials. Polish formulations containing silicone materials are disclosed in U.S. Pat. No. 3,508,933, issued Apr. 28, 1970, in U.S. Pat. No. 3,836,371, issued Sept. 17, 1974, and in U.S. Pat. No. 3,890,271, issued June 17, 1975. While these silicone materials are characterized as being aminofunctional siloxanes, they are not zwitterionomers as are the compositions of the present invention, and it is not believed to be known to employ zwitterionomers in polish formulations. What appears to be a zwitterion in a polish in Japanese Publication No. 8029/80 is actually an amido acid. Such acids are low molecular weight hard solids in contrast to the high molecular weight fluids of the present invention. Further, the function of such amido acids is to increase the luster or shine of a polish, rather than to cause water to sheet as in the present invention. Zwitterionomers are not new as exemplified by U.S. Pat. No. 4,525,567, issued June 25, 1985, to Campbell et al, however, the zwitterionomers of Campbell et al. are characterized as being sultone based zwitterionomers whereas the zwitterionomers of the present invention are sulfur free amine cyclic-anhydride based zwitterionomers in contrast thereto. Further, the zwitterionomers of the present invention are lactone free in contrast to Campbell et al. A further distinction exists between the instant invention and that of Campbell et al, in that in Campbell et al, there is disclosed a low cost process of making the zwitterions by combining OH endblocked polydimethylsiloxane, a functional silane, and an acid catalyst. In the present invention, however, the zwitterionomers can be prepared from fully-premade aminofunctional siloxane polymers which are not silicon functional. As such, the compositions of the present invention provide new and unique advantages over typical prior art polish formulations which will become apparent hereinafter.
SUMMARY OF THE INVENTION
This invention relates to a polish formulation containing as components thereof at least one member selected from the group consisting of waxes, solvents, surfactants, thickening agents, abrasives, dyes, odorants, and other ingredients normally used in making polishes. The improvement includes incorporating therein a composition which is the reaction product of a cyclic acid anhydride and an aminofunctional siloxane selected from the group consisting of (A) a blend or reaction product of a hydroxyl endblocked polydimethylsiloxane having a viscosity in the range of about 10 to 15,000 cs at twenty-five degrees centigrade, and a silane selected from the group consisting of those having the general formulae R" n (R'O) 3-n Si(CH 2 ) 3 NHR"' and R" n (R'O) 3-n SiRNHCH 2 CH 2 NH 2 wherein R"' is a hydrogen atom or a methyl radical, R" is a monovalent hydrocarbon radical free of aliphatic unsaturation and contains from one to six carbon atoms, n has a value of from zero to two, R' is an alkyl radical containing from one to four carbon atoms, and R is a divalent hydrocarbon radical free of aliphatic unsaturation and contains three to four carbon atoms, (B) a blend or reaction product of a hydroxyl endblocked polydimethylsiloxane having a viscosity in the range of about 10 to 15,000 cs at twenty-five degrees centigrade, a silane selected from the group consisting of those having the general formula (R 1 O) 3 --SiR 2 NHR 3 and (R 1 O) 3 --SiR 2 NHCH 2 CH 2 NH 2 wherein R 1 is an alkyl radical containing from one to four carbon atoms, R 2 is a divalent hydrocarbon radical free of aliphatic unsaturation and contains from three to four carbon atoms, and R 3 is selected from the group consisting of the hydrogen atom and the methyl radical, and a silane having the general formula X 3 SiZ wherein X is selected from the group consisting of alkoxy and acyloxy radicals containing from one to four carbon atoms, and Z is nonhydrolyzable radical selected from the group consisting of hydrocarbon radicals, halogenated hydrocarbon radicals, and radicals composed of carbon, hydrogen, and oxygen atoms, wherein the oxygen atoms are present in hydroxyl groups, ester groups, or ether linkages, there being from one to ten carbon atoms in the Z radical, and (C) a blend or reaction product of a polydimethylsiloxane having a viscosity in the range of about one to 15,000 cs at twenty-five degrees centigrade, and a silane selected from the group consisting of those having the general formulae R" n (R'O) 3-n Si(CH 2 ) 3 NHR"' and R" n (R'O) 3-n SiRNHCH 2 CH 2 NH 2 wherein R"' is a hydrogen atom or a methyl radical, R" is a monovalent hydrocarbon radical free of aliphatic unsaturation and contains from one to six carbon atoms, n has a value of from zero to two, R' is an alkyl radical containing from one to four carbon atoms, and R is a divalent hydrocarbon radical free of aliphatic unsaturation and contains three to four carbon atoms. (C) above is a specific species and a trimethylsilyl endblocked aminofunctional siloxane produced by incorporating conventional trimethylsilyl functional silanes or siloxanes into the aminofunctional siloxanes.
In a specific embodiment of the present invention, the acid anhydride is selected from the group consisting of succinic anhydride, maleic anhydride, phthalic anhydride, and carbon dioxide. The reaction product is an aminofunctional siloxane zwitterion having the structural formula: ##STR1## where Me is methyl, x is an integer of from about forty to about four hundred, y is an integer of from about one to about twenty, and R 4 is ethylene, vinylidene, or phenylene. x is preferably 188 and y is ten.
The zwitterionic aminofunctional siloxane can, if desired, be further reacted with a strong acid resulting in an equilibrium of the zwitterion and a conjugate acid base pair of the zwitterion and the acid; for which the extent of conjugate acid base pair formation depends upon the pKa of the strong acid and the dielectric strength of the solvent. In such case, the strong acid is selected from the group consisting of hydrochloric, hydrobromic, hydriodic, nitric, perchloric, phosphoric, and organic acids. The organic acid is selected from the group consisting of acetic, propionic, butyric, valeric, caproic, benzoic, halo-substituted benzoic, and nitro-substituted benzoic. The conjugate acid base pair of the zwitterion and the strong acid has the structural formula: ##STR2## where Me is methyl, x is an integer of from about forty to about four hundred, y is an integer of from about one to about twenty, A is an anion and the conjugate base of the strong acid, and R 4 is ethylene, vinylidene, or phenylene. x again is preferably 188 and y is ten.
The invention is further directed to a method of sheeting water on a surface in which there is applied to the surface before the surface is exposed to water a polish formulation containing as components thereof the ingredients enumerated above.
The invention is also directed to a method of making an aminofunctional siloxane zwitterionomer comprising reacting an acid anhydride with an aminofunctional siloxane selected from the group consisting of (A) and (B) as set forth and detailed above.
Still further, the present invention relates to an aminofunctional zwitterionomeric siloxane compound which is a reaction product of an acid anhydride with an aminofunctional siloxane selected from the group consisting of (A) and (B) again as defined hereinabove.
It is therefore an object of the present invention to provide a new and novel type of polish formulation particularly adapted for use on motor vehicles in which water coming into contact with such surfaces is sheeted and drained away rather then being beaded and repelled as has been the practice of prior art formulations in the past. A particular advantage to this approach is that vehicles need not be washed following every period of rain as has been the case due to spots caused by the beads. Instead, with the sheeting action of the compositions of the present invention, this disadvantage is overcome, and rain is sheeted away from vehicle surfaces without leaving behind the unaesthetic appearance of rings containing debris.
These and other features, objects, and advantages, of the herein described instant invention, should become more apparent when taken in conjunction with the following detailed description thereof.
DETAILED DESCRIPTION OF THE INVENTION
A surfactant is a compound that reduces surface tension when dissolved in a liquid. Surfactants exhibit combinations of cleaning, detergency, foaming, wetting, emulsifying, solubilizing, and dispersing properties. They are classified depending upon the charge of the surface active moiety. In anionic surfactants, the moiety carries a negative charge as in soap. In cationic surfactants, the charge is positive. In non-ionic surfactants, there is no charge on the molecule, and in amphoteric surfactants, solubilization is provided by the presence of positive and negative charges linked together in the molecule. A zwitterion is a special category and is a molecule that exists as a dipolar ion rather than in the un-ionized form. The molecule is neutral overall but has a large charge separation like an amino acid. Zwitterions are also known as hybrid ions, and internal or intramolecular salts. In the case of amino acids, they are electrolytes having separated weakly acidic and weakly basic groups. For example, while shown as H 2 N--R--COOH, in aqueous solution .sup.⊕ H 3 N--R--COO - is the actual species where an internal proton transfer from the acidic carboxyl to the basic amino site is complete. The uncharged species has separate cationic and anionic sites but the positive and the negative ions are not free to migrate. Thus, it is a complex ion that is both positively and negatively charged. Alkyl betaines are also representative of zwitterions and are a special class of zwitterion where there is no hydrogen atom bonded to the cationic site. Some silicones are also zwitterions and it is this special category of silicone zwitterion to which the present invention relates.
The zwitterionomeric aminofunctional siloxane compositions of the present invention may be prepared in accordance with the following schematic: ##STR3##
It should be noted in the above schematic that formula (I) denotes an aminofunctional siloxane, formula (II) denotes the zwitterionomer of the present invention, and formula (III) indicates the conjugate acid base pair of the zwitterionomer and the strong acid (HA). Formula (I) is generically described as an aminofunctional siloxane selected from the group consisting of reaction products of (A) a blend or reaction product of a hydroxyl endblocked polydimethylsiloxane having a viscosity in the range of about 10 to 15,000 cs at twenty-five degrees centigrade, and a silane selected from the group consisting of those having the general formulae R" n (R'O) 3-n Si(CH 2 ) 3 NHR"' and R" n (R'O) 3-n SiRNHCH 3 CH 2 NH 2 wherein R"' is a hydrogen atom or a methyl radical, R" is a monovalent hydrocarbon radical free of aliphatic unsaturation and contains from one to six carbon atoms, n has a value of from zero to two, R' is an alkyl radical containing from one to four carbon atoms, and R is a divalent hydrocarbon radical free of aliphatic unsaturation and contains three to four carbon atoms, (B) a blend or reaction product of a hydroxyl endblocked polydimethylsiloxane having a viscosity in the range of about 10 to 15,000 cs at twenty-five degrees centigrade, a silane selected from the group consisting of those having the general formulae (R 1 O) 3 --SiR 2 NHR 3 and (R 1 O) 3 --SiR 2 NHCH 2 CH 2 NH 2 wherein R 1 is an alkyl radical containing from one to four carbon atoms, R 2 is a divalent hydrocarbon radical free of aliphatic unsaturation and contains from three to four carbon atoms, and R 3 is selected from the group consisting of the hydrogen atom and the methyl radical, and a silane having the general formula X 3 SiZ wherein X is selected from the group consisting of alkoxy and acyloxy radicals containing from one to four carbon atoms, and Z is a nonhydrolyzable radical selected from the group consisting of hydrocarbon radicals, halogenated hydrocarbon radicals, and radicals composed of carbon, hydrogen, and oxygen atoms, wherein the oxygen atoms are present in hydroxyl groups, ester groups, or ether linkages, there being from one to ten carbon atoms in the Z radical, and (C) a blend or reaction product of a polydimethylsiloxane having a viscosity in the range of about one to 15,000 cs at twenty-five degrees centigrade, and a silane selected from the group consisting of those having the general formulae R" n (R'O) 3-n Si(CH 2 ) 3 NHR"' and R" n (R'O) 3-n SiRNHCH 2 CH 2 NH 2 wherein R"' is a hydrogen atom or a methyl radical, R" is a monovalent hydrocarbon radical free of aliphatic unsaturation and contains from one to six carbon atoms, n has a value of from zero to two, R' is an alkyl radical containing from one to four carbon atoms, and R is a divalent hydrocarbon radical free of aliphatic unsaturation and contains three to four carbon atoms. Such compositions are described in more or less detail in U.S. Pat. No. 3,508,933, issued Apr. 28, 1970, in U.S. Pat. No. 3,836,371, issued Sept. 17, 1974, and in U.S. Pat. No. 3,890,271, issued June 17, 1975. The preparation of these compositions and their use in polishes is also detailed in the aforementioned patents, the disclosures of which are incorporated herein by reference thereto. Particular of such compositions prepared and falling within the scope of the present invention is set forth in Table I.
TABLE I______________________________________Compound (I) x y______________________________________A 45.75 2.25B 69.25 3.75C 96 2D 188 10E 295.9 2.1F 400 8______________________________________
In the above schematic, the acid anhydride which is reacted with compositions of formula (I) is selected from the group consisting of succinic anhydride, maleic anhydride, phthalic anhydride, itaconic anhydride, or other cyclic anhydrides, and carbon dioxide, with the first named anhydride being the preferred material for use herein.
The resulting reaction product indicated by formula (II) in the foregoing schematic is an aminofunctional siloxane zwitterionomer having the structural formula: ##STR4## where Me is methyl, x is an integer of from about forty to about four hundred, y is an integer of from about one to about twenty, and R 4 is ethylene, vinylidene, or phenylene. x is preferably 188 and y is ten. The zwitterionic aminofunctional siloxane of formula (II) is further reacted with a strong acid (HA) resulting in an equilibrium of the zwitterion (II) and a conjugate acid base pair indicated by formula (III) of the zwitterion (II) and the acid (HA) which depends upon the pKa of the strong acid and the dielectric strength of the polish solvent. The strong acid (HA) is selected from the group consisting of hydrochloric, hydrobromic, hydriodic, nitric, perchloric, phosphoric, and organic acids, wherein the organic acid may be one of the group consisting of acetic, propionic, butyric, valeric, caproic, benzoic, halo-substituted benzoic, and nitro-substituted benzoic. The resulting formula (III) as shown above of the conjugate acid base pair of the zwitterion (II) and the strong acid (HA) has the structural formula: ##STR5## where again Me is methyl, x is a integer of from about forty to about four hundred, y is an integer of from about one to about twenty, A is an anion, and R 4 is ethylene, vinylidene, or phenylene. x is preferably 188 and y is ten. This is a specific embodiment of the present invention, and is not a requirement that the conjugate composition (III) be formed in every instance. However, it should be noted that where the conjugate (III) is formed, it necessitates the presence in the formulation of an acid. The equilibrium reached between the zwitterionomer (II) and the conjugate (III) depends on the strength of the acid. Where the acid is strong, the conjugate (III) predominates. Where the acid is weaker, the zwitterionomer predominates. As noted hereinbefore, such equilibrium depends upon the pKa of the strong acid and the dielectric strength of the solvent. Preferred solvents in accordance with the present invention are ethanol and toluene, for example.
The zwitterionic aminofunctional siloxane of formula (II) can also be further reacted with a basic compound resulting in an equilibrium of the zwitterion (II) and a conjugate acid base pair indicated by formula (IV) of the zwitterion (II) and the basic compound which depends upon the relative pKa's of the base B and the basic sites of the zwitterion, and the dielectric strength of the medium. The strong base is selected from the group consisting of organic amines, hydroxides, and lewis bases. The resulting formula (IV) as shown below of the conjugate acid base pair of the zwitterion (II) and the basic compound has the structural formula: ##STR6## where again Me is methyl, x is an integer of from about forty to about four hundred, y is an integer of from about one to about twenty, BH is a cation and a protonated base, and R 4 is ethylene, vinylidene, or phenylene. x is preferably 188 and y is ten. This is a specific embodiment of the present invention, and is not a requirement that the conjugate composition (IV) be formed in every instance. However, it should be noted that where the conjugate (IV) is formed, it necessitates the presence in the formulation of a basic compound such as dibutyl amine. The equilibrium reached between the zwitterionomer (II) and the conjugate (IV) depends on the strength of the base. Where the base is strong, the conjugate (IV) predominates. Where the base is weaker, the zwitterionomer predominates. As noted hereinbefore, such equilibrium depends upon the relative pKa'3 s of the strong base and zwitterion, and the dielectric strength of the solvent.
The aminofunctional siloxanes of the formula (I) type may also be prepared by an alternate method from that set forth in U.S. Pat. No. 3,508,993, U.S. Pat. No. 3,836,371, and U.S. Pat. No. 3,890,271, aforementioned. In the alternate method, the starting material is methyldimethoxy ethylenediaminoisobutyl silane of the formula:
CH.sub.3 (CH.sub.3 O).sub.2 SiCH.sub.2 CH(CH.sub.3)CH.sub.2 NHCH.sub.2 CH.sub.2 NH.sub.2
This aminofunctional silane is distilled to an active concentration of between about 95-99%. The silane is hydrolyzed with three moles of water added to one mole of the silane. The material is batch distilled at atmospheric pressure and at a temperature of about one hundred and thirty degrees centigrade. Methanol and residual water are then removed by vacuum stripping to yield an aminofunctional hydrolyzate. The aminofunctional hydrolyzate is added to a mixture of polydimethylsiloxane of viscosity of 1.5 centistokes, a dimethylcyclic of the formula (Me 2 SiO) n where n is three, four, or five, and a catalyst such as potassium hydroxide or potassium silanolate. This mixture is equilibriated to a polymer by agitation and heat at about one hundred-fifty degrees centigrade. The mixture is cooled to about 80-90 degrees centigrade or lower and the catalyst is neutralized by the addition of acetic acid accompanied with mixing. The non-volatile content is increased by stripping of the volatiles under vacuum, followed by filtration of the material in a pre-coated plate and frame filter for the purpose of removing any haze in order to obtain a clarified product. A typical example of this procedure is set forth below.
EXAMPLE I
Into a round bottom flask was added 3,482,8 grams of a dimethylcyclic, 439.2 grams of hydrolyzate, 78.4 grams of polydimethylsiloxane of viscosity of 1.5 cs, and 38.3 grams of potassium silanolate catalyst. The contents of the flask were mixed under a nitrogen atmosphere for twenty minutes. Heat was applied to the flask and the contents were maintained at one hundred-fifty degrees centigrade for four hours. The mixtures was cooled to thirty-three degrees centigrade. The catalyst was neutralized by the addition to the flask of 2.14 grams of acetic acid. The fluid was stirred overnight and filtered. The resulting product was water clear and had a viscosity of 354 cs. The product contained five mol percent amine and was identified as the material set forth in Table I where x=188 and y=10.
EXAMPLE II
Example I was repeated in order to produce an aminofunctional siloxane of the formula (I) type. Zwitterionic aminofunctional siloxanes materials of the formula (II) type were obtained by separately dissolving succinic anhydride in dimethoxyethane in order to provide a ten weight percent solution of the anhydride. The succinic anhydride was added from a dropping funnel to the contents of the flask containing the formula (I) type aminofunctional siloxane, and the solution was heated with stirring at about fifty-five degrees centigrade and under a nitrogen flow. The mixture was vacuum distilled at about twenty millimeters of mercury or less under a nitrogen atmosphere at one hundred-twenty degrees centigrade for about forty-five minutes or until the vapor reached about eighty degrees centigrade, to remove all of the dimethoxyethane and yielding the zwitterionomer. The resulting zwitterionomer was distilled to a solids content of about eighty-eight percent. This example was repeated producing zwitterionomers having amine mol percentages ranging from about 0.5 mol percent to about eight mol percent.
The zwitterionic aminofunctional siloxanes of the present invention, were formulated into polishes in place of the aminofunctional siloxanes employed in U.S. Pat. Nos. 3,508,933, 3,836,371, and 3,890,271, causing water coming into contact with the surface treated, to sheet rather than to bead, as is conventional with prior art polish formulations. The polishes so formulated were applied both to actual vehicle surfaces as well as test panels. Water contacting the treated surfaces sheeted water and was noted by visual observation. Thus, prior art polishes lay down a film, but the film is a water beading film, in contrast to the water sheeting film obtained when the zwitterionomeric compositions of the present invention are employed. In either case, a film is formed by applying the polish to the surface to be treated and by rubbing in the polish onto the surface and allowing the solvent to evaporate, leaving behind the film. Inclusion of the zwitterionomers of the present invention, however, sheets the water, whereas omission beads the water. A distinct advantage of a water sheeting film is that, in contrast to a film that beads the water, the water sheeting film will not collect dust and debris following a rain as do water beading films, which necessitate that the surface be washed once more in order to remove the spots and rings caused by the water beading type of film. The water sheeting films of the present invention are of general application including such surfaces as motor vehicles, boats and navigable crafts, wood surfaces, plastic surfaces, and fiber surfaces. The films produce a high gloss, are durable, and are easy to apply.
It will be apparent from the foregoing that many other variations and modifications may be made in the structures, compounds, compositions, and methods described herein without departing substantially from the essential features and concepts of the present invention.
Accordingly, it should be clearly understood that the forms of the invention described herein are exemplary only and are not intended as limitations on the scope of the present invention.
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A polish formulation containing as components at least one member selected from the group consisting of waxes, solvents, surfactants, thickening agents, abrasives, dyes, odorants, and other ingredients normally used in making polishes, and as an improvement incorporating a composition which is the reaction product of an acid anhydride and an aminofunction siloxane. The resulting zwitterionic aminofunctional siloxane can, if desired, be further reacted with a strong acid to provide an equilibrium of the zwitterion and a conjugate acid base pair of the zwitterion and the acid. The invention also includes a method of sheeting water on a surface with the polish, a method of making an aminofunctional siloxane zwitterionomer, and an aminofunctional zwitterionomeric siloxane compound which is the reaction product.
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FIELD OF THE INVENTION
[0001] This invention relates to a method and apparatus for encoding/decoding image data. It is particularly applicable to the encoding/decoding of images that can be separated into their constituent parts as may be used in composite picture systems used in law enforcement, artistic creations, recreation and education.
BACKGROUND
[0002] It is known in the art to create images on the basis of components that are assembled to form a complete image. For example, a common technique for synthesizing single images of faces involves horizontally dividing the image of a face into bands for different features or the face such as hair, eyes, nose, mouth, and chin, respectively. Paper strips containing exemplary features are then be combined to form a composite drawing of a face. Yet another example involves a program element running on a computing platform which allows a user to select individual components and combining them on a pre-selected face. In a typical interaction, the user first selects the shape of the face then eyes, nose, mouth and other components and combines them to form a facial image. Many variations on this theme can be used as described in Kakiyama et al. U.S. Pat. No. 5,600,767, Yoshino et al. U.S. Pat. No. 5,644,690, Sato et al. U.S. Pat. No. 5,537,662 and Belfer et al. U.S. Pat. No. 5,649,086 whose contents are hereby incorporated by reference. For example, the Sato et al. Patent, entitled Electronic Montage composing apparatus, describes a system for creating a montage image of a face using a plurality of basic parts stored in a library.
[0003] In constructing an image, pictorial entities are selected from a library of pictorial entities as assembled into images. These images may then be stored on a computer readable medium commonly referred to as a database or repository. Often, the storage of an image requires significant amounts of memory, often necessitating large repositories. For example, a composite picture system used in a police department often requires maintaining records of thousands of individuals. The images are typically stored in files in some graphical format such as a “bitmap”, “gif” or “jpeg” are other format. Although such encoding schemes provide a compressed representation of the image, the memory required for storing the image remains significant. In addition, compression methods of the type described above generally degrade the quality of the image. The size and quality of images is also particularly significant when the images are transmitted from one site to another via a digital link. For example, a given police station may transmit a composite picture to another police station in order to share information about a given suspect.
[0004] Thus, there exists a need in the industry to refine the process of encoding images such as to reduce the memory requirements for storage and the bandwidth required for the transmission of the image.
SUMMARY OF THE INVENTION
[0005] The invention provides a novel method and an apparatus for encoding images.
[0006] For the purpose of the specification, the expression “basic elements” is used to describe a part of a specific image. In the preferred embodiment, a basic element is comprised of a pictorial entity conditioned by a set of image qualifiers. Examples of pictorial entities in a facial image are noses, eyes, mouths and eyebrows. In the preferred embodiment, pictorial entities are grouped into classes. For example, in composite picture system, all nose pictorial entities are grouped into the “NOSE” class and all the eye pictorial entities are grouped in the “EYE” class. Each class of pictorial entities is associated to a set of image qualifiers that are used to condition the pictorial entities in the associated class. The image qualifiers may include position qualifiers, zoom qualifiers, color qualifier and the likes.
[0007] For the purpose of this specification, the basic elements used in the special case of a facial image are referred to as “basic morphological elements”.
[0008] For the purpose of this specification, the word “symbol” is used to designate a representation of an object, image, qualifier or the likes. In a specific example, a symbol may be an index mapped to a memory location storing data elements such as a pictorial entity or image qualifier.
[0009] According to a broad aspect, the invention provides, a computer readable storage medium comprising a program element suitable for use on a computer having a memory. The program element is operative to create a first input to receive a set of element codes. The element codes characterized a portion of an image and included at least one symbol. A given symbol is a representation of a certain characteristic of the portion of the element code. A given symbol can acquire a set of possible values indicative of variations of the certain characteristic with which it is associated. The program element is also operative to create a second input to receive code factors associated to respective symbols of the set of element codes. A given code factor is assigned a value that exceeds the highest value that the symbol with which it is associated can acquire. The program element is operative to process the set of element codes to derive an image code. The image code is a compressed digital representation of the image, and is derived at least in part on the basis of the plurality of code factors. The image code can then be released as the output.
[0010] In a preferred embodiment, the image code is a number in a given base. Preferably, a large base is used in order to obtain a reduced number of characters in the image code.
[0011] In a preferred embodiment of the invention, the encoding method and apparatus is integrated into a picture system. The picture system creates images on the basis of images of basic individual parts, herein referred to as basic elements. In the preferred embodiment, the picture system includes a library of pictorial entities and qualifiers, an image builder unit, an encoding unit, a decoding unit and a factor table.
[0012] Each basic element in an image is assigned a unique identifier, herein referred to as element code. The element code contains information data elements, herein referred to as symbols. In a specific embodiment, the element code for each basic element includes a symbol that characterizes the pictorial element. In a preferred embodiment, the element code includes a plurality if symbols. In a specific example two (2) symbols are used namely an pictorial entity symbol and a position qualifier symbol. The element code may contain additional symbols without detracting from the spirit of the invention. For example symbols representative of other image qualifiers may be used such as color, zoom and other image effects may be used. An image is constructed by a set of basic elements. The basic elements present in a given facial image are said be “active” in the given image. The set of active elements is stored in a data structure suitable for that purpose. In a specific example this data structure is an image data table. The image data table stores for each class a record, each record containing a set of fields, each field describing the active pictorial entity and qualifiers.
[0013] The number variations in each of the symbols for each of the classes is stored in a table, herein referred to as a code factor table. The code factor table provides information about the number of possible variations in an image. For each class, the code factor table stores a record, each record containing a set of fields, each field describing a maximum factor. The maximum factor in the code factor table is the largest identifier used for the given factor. Each symbol in the image data table is mapped to a factor in the code factor table.
[0014] According to another broad aspect, the invention provides an apparatus for encoding an image, the image comprising a set of basic elements, each basic element of the set of basic elements being associated to an element code. An encoding unit receiving as input the code factors and the element codes. The encoding unit processes the set of element codes to derive an image code, the image code being a compressed digital representation of the image derived at least in part on the basis of said plurality of code factors. The encoding unit then outputs the image code.
[0015] According to another broad aspect, the invention provides a method for encoding an image, the image comprising a set of basic elements, each basic element of the set of basic elements being associated to an element code. A processing step receives as input the code factors and the element codes to derive an image code. The image code is a compressed digital representation of the image derived at least in part on the basis of said plurality of code factors. The image code is the released.
[0016] In a preferred embodiment, the image code can be used to reproduce the image described by the image code. Image data may be obtained by combining the code factors and the image code with a decoding device. The image data is obtained by applying the inverse operations in the reverse order than those applied in the encoding process to the image code.
[0017] The image code allows each image to be described with a very small number of characters permitting the rapid transmission of the image over a data transmission medium. The receiving device has a decoding unit that is capable of extracting data information from the image code.
[0018] According to another broad aspect, the invention provides a method, apparatus and computer readable medium for decoding an image, the image comprising a set of basic elements, each basic element of the set of basic elements being associated to an element code. A processing step receives as input the code factors and the image code to derive the element codes. The element codes are then released.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] These and other features of the present invention will become apparent from the following detailed description considered in connection with the accompanying drawings. It is to be understood, however, that the drawings are designed for purposes of illustration only and not as a definition of the limits of the invention for which reference should be made to the appending claims.
[0020] [0020]FIG. 1 shows an apparatus including an embodiment of the invention;
[0021] [0021]FIG. 2 shows a high-level block diagram of functional units of the image system including an image encoder in accordance with the spirit of the invention;
[0022] [0022]FIG. 3 shows a high-level block diagram of functional units of the image system including an image decoder in accordance with the spirit of the invention;
[0023] [0023]FIG. 4 shows a detailed block diagram of the encoding process in accordance with the spirit of the invention;
[0024] [0024]FIG. 5 shows a detailed block diagram of the decoding process in accordance with the spirit of the invention;
[0025] [0025]FIGS. 6 a and 6 b show flow diagrams for the creation of an image and the facial code in accordance with an embodiment of the invention;
[0026] [0026]FIG. 7 shows an alternative apparatus including an embodiment of the invention;
[0027] [0027]FIG. 8 shows apparatuses including an embodiment of the invention connected by a data transmission medium.
DETAILED DESCRIPTION
[0028] In the preferred embodiment, the encoding method and apparatus in accordance with the invention is integrated into a picture system for creating images on the basis of images of individual parts, herein referred to as basic elements. For the sake of simplicity, the specification will describe an embodiment of the invention integrated into a composite picture system. It is to be understood that the encoding method and apparatus may be used in systems for creating images on the basis of individual constituent parts other than a composite picture system without detracting from the spirit of the invention.
[0029] In a preferred embodiment, as shown in FIG. 1, the composite picture system includes a general-purpose digital computer including a processor 100 linked to a machine-readable storage element 108 that may be in the form of a mass storage device such as a hard-drive, a CD-ROM or any other suitable storage medium. The system further includes a device for visualizing the facial image such as a computer monitor 110 or a printing device. The preferred embodiment also provides data input on which a user interface 112 is supported in order to allow the user to select through a touch screen, keyboard, pointing device or other input means, the individual basic morphological elements and to view the combined result on the display screen 110 . The latter 110 is likely to be part of the data input. Optionally, the system further provides a data transmission medium 114 such as a telephone line, LAN, digital cable, optical cable, wireless transmission device or any other suitable means for transmitting an image from the general purpose digital computer to a receiving device. The computer readable medium 108 storing the composite picture system includes of a set of modules namely a library of pictorial entities and image qualifiers 104 and program instructions 102 interacting with the library of pictorial entities and image qualifiers to create a facial image. The computer readable medium 108 may also include symbols where each symbol is associated to a respective one of the pictorial entities and image qualifiers in the library of pictorial entities and image qualifiers 104 . The computer readable medium further comprising a set of code factors, each code factor being associated to a set of symbols, a given code factor being larger that the largest symbol in the set with which it is associated. The computer readable medium further comprises an encoding program element 116 to encode a facial image.
[0030] In the preferred embodiment the composite picture system comprises an electronic library of pictorial entities and image qualifiers 104 . Each pictorial entity in the library is an image of a facial part or an accessory such as glasses, earrings or other. The pictorial entities in the library 104 are organized into morphological classes, each class describing a part of the face. In a preferred embodiment, the following basic morphological classes are used: hairstyle, forehead, eyebrows, eyes, nose, mouth, chin, moustache, beard, wrinkles and glasses. The pictorial entities are stored on a computer readable medium. The images may be compressed in a format suitable for graphical storage such as a bitmap (BMP), GIF of JPEG file format. Other file formats may be used here without detracting from the spirit of the invention.
[0031] In the preferred embodiment, each pictorial entity is identified with a pictorial entity symbol. Typically, the pictorial entity symbol is a sequence of alphanumeric characters. The pictorial entity symbols are stored on a computer readable medium in the database of symbols. Each image qualifier in the library is a characteristic of a corresponding class. The image qualifiers in the library 104 may be organized into qualifier types, each qualifier type describing a certain characteristic of the pictorial entity. In a preferred embodiment, the following qualifier types are used: position and color. Other image qualifiers such as zoom and the likes may be used without detracting from the spirit of the invention. The image qualifiers are stored on a computer readable medium. In the preferred embodiment, each image qualifier is identified with an image qualifier symbol. Typically, the image qualifier symbol is a sequence of alphanumeric characters. The image qualifier symbols are stored on a computer readable medium in the database of symbols.
[0032] In a preferred embodiment, a basic morphological element includes a pictorial entity and a set of image qualifiers. The image qualifiers condition the pictorial entity to alter the visual effect of the latter. For example the image qualifier may modify the position, color zoom or any other visual effect of the pictorial entity. The purpose of the specification, the expression “basic morphological element” is used to refer to the pictorial entity conditioned by the image qualifiers. Each basic morphological element is associated to an element code. The element code contains a set of symbols. In a specific example, the element code for each basic morphological element includes two (2) symbols namely a pictorial entity symbol and a position qualifier symbol. The pictorial entity symbol identifies the pictorial entity within a given class in the library of pictorial entities and image qualifiers. Preferably, the pictorial entities of a given class are each assigned a unique symbol. The symbols need not be consecutive provided they can be ordered and the largest symbol assigned to a pictorial entity of a given class can be determined. The position qualifier symbol provides information on the position of the pictorial entity in the facial image. Preferably, the number of possible positions for a pictorial entity of a given class is predetermined. In a specific example, there may be 5 possible positions for the eyes in a facial image. Each position is assigned a position qualifier symbol such as a number from 1 to 5 and each position qualifier symbol corresponds to a position the pictorial entity with which it is associated can acquire. The element code may contain additional symbols without detracting from the spirit of the invention. For example, the element code may contain a “zoom” qualifier indicating the zoom level of the pictorial entity.
[0033] A facial image is constructed by a set of basic morphological elements. The basic morphological element present in a given facial image is said be “active” in the given image. The set of active basic morphological elements is stored in a data structure suitable for that purpose. In a specific example this data structure is an image data table. The image data table stores for each class a record. Each records describes an element code, each record containing a set of fields, each field describing the pictorial entity symbol, position qualifier symbol and any other symbol. The entries in the image data table are referred to as active element symbols. The table below shows a specific example of an image data table.
Pictorial entity Position qualifier Class symbol symbol EYES 34 2 LIPS 2 1 GLASSES 111 17
[0034] As shown above, a basic morphological element of class “EYES” with a pictorial entity symbol “34” which is positioned at position “2” is active in the facial image.
[0035] The number variations in each of the symbols for each of the classes is stored in a table, herein referred to as a code factor table. The code factor table provides information about the number of possible variations in a facial image. For each class, the code factor table stores a record, each record containing a set of fields, each field describing a maximum factor. The maximum factor in the code factor table is the largest symbol assigned to an image qualifier or pictorial entity for a given class. Alternatively, the maximum factor is larger that the largest symbol assigned to an image qualifier or pictorial entity for a given class. This will best be understood in conjunction with a specific example. The table below shows an example of a code factor table.
Maximum pictorial Maximum position Class entity factor qualifier factor EYES 900 5 LIPS 600 26 GLASSES 200 23
[0036] In the above table, there are three classes namely “EYES”, “LIPS” and “GLASSES” having “900”, “600” and “200” pictorial entities respectively as their maximum factor. In this specific example, the pictorial entities are assigned numerical symbols no larger that the maximum factor for each respective class. In the case where pictorial entities are not assigned consecutive numerical symbols, the second column would contain the largest pictorial entity symbol assigned to the pictorial entities of the respective class. The third column includes the maximum position qualifier factor. Class “LIPS” for example has “26” as is maximum position qualifier factor. In this specific example, positions for the individual pictorial entities are pre-determined. Each pre-determined position is given a numerical position symbol that is between 1 and the maximum position qualifier factor in the code factor table.
[0037] As shown in FIG. 2, a facial code 206 for a given facial image may be created by combining the code factors 200 and the image data 202 with an encoding device 204 . In a preferred embodiment, the encoding device 204 derives the facial code in accordance with the process described in FIG. 4.
[0038] The facial code is first initialized at a based value 400 . Preferably, this base value is zero (0). Following this, the encoding method begins with the first class of the pictorial entities 402 and the first symbol of the element code of the class 404 . The facial code is first multiplied 406 by the corresponding factor value in the code factor table. An example in conjunction with the factor table below will better illustrate this step 406 .
Maximum pictorial Maximum position Class entity factor qualifier factor EYES 900 5 LIPS 600 26 GLASSES 200 23
[0039] If class “EYES” for the pictorial entity is being considered, then the facial code is multiplied by the pictorial entity factor “900”. Following this, the pictorial entity symbol from the image data table is added 408 to the facial code. An example in conjunction with the image data table below will better illustrate this step 408 .
Pictorial entity Position qualifier Class symbol symbol EYES 34 2 LIPS 2 1 GLASSES 111 17
[0040] If class “EYES” for pictorial entity is being considered, then the pictorial entity symbol “34” is added to the facial code. The system then proceeds to step 410 that checks if there are any symbols remaining for the current class. In the affirmative, the system proceeds to step 412 that determines which symbol to consider next. In the example above, the following symbol to consider is the position qualifier symbol. The system then restarts at step 406 . In the event that all symbols for the current class have been processed, step 410 is answered in the negative and the system proceeds to step 414 . Step 414 checks if there are any classes remaining. In the affirmative the system proceeds to step 416 that determines which class to consider next. In the example above, the next class to consider is the “LIPS” class. The system then restarts at step 404 with the first symbol of the element code of the new class. In the event that all classes have been processed, step 414 is answered in the negative and the system proceeds to step 418 with the complete facial code.
[0041] As a variant, the facial code may be further comprise version number information for the purpose of differentiating between different version numbers of the composite picture system. This in turn permits to insure that a composite picture system using the facial code produced by the process described above is not induced in error if its version is not the same than that of the composite picture system that created the image. In a specific example, the version number information is integrated to the facial code by multiplying the code by a specific number.
[0042] In the preferred embodiment, the facial code is a number in a given base. Preferably, a large base is used in order to obtain a reduced number of characters in the facial code. In a specific example, the facial code is a number in base “62” with characters {0-9, a-z, A-Z}. Other bases may be used without detracting from the spirit of the invention. It is to be noted that the computations in steps 406 and 408 of the encoding process may result in very large numbers in the order of 10E+66 or bigger for large systems. It may therefore be preferable to provide some specialized functions for the computation of the multiplication and addition operations for these numbers in order to avoid the possibility of overflow. The implementation of such computations will be readily available to the person skilled in the art to which this invention pertains.
[0043] As a variant, characters in the facial code that may be visually confusing are replaced by non-alphanumeric characters. For instance the letter “O” and the number “0” are similar in appearance as are the letter “I”, the letter “l” and the digit “1”. In a specific example, the characters in the facial code that may be visually confusing are replaced by non-alphanumeric characters such as “+”, “=”, “@” and so once the code is computed.
[0044] In a preferred embodiment, the facial code can be used to reproduce the facial image described by the facial code. As shown in FIG. 3, facial image data 304 may be obtained by combining the code factors 200 and the facial code 302 with a decoding device 300 . The facial image data 304 is obtained by applying the inverse operations in the reverse order than those applied in the encoding process to the facial code. In a preferred embodiment, the decoding device 300 derives the facial image data 804 in accordance with the process described in FIG. 5.
[0045] The facial code is first obtained 500 . Following this, the decoding process begins with the last class of the pictorial entities 502 and the last symbol of the element code of that class 504 . The facial code is first divided 506 by the factor value in the code factor table associated to the symbol being considered. An example in conjunction with the factor table below will better illustrate this step 506 .
Maximum pictorial Maximum position Class entity factor qualifier factor EYES 900 5 LIPS 600 26 GLASSES 200 23
[0046] If a class “GLASSES” for the position qualifier is being considered, then the facial code is divided by the factor “23”. Following this, the remainder of the division performed in step 506 is stored as the corresponding position qualifier symbol in the image data table 508 . The system then proceeds to step 510 that checks if there are any symbols remaining for the current class. In the affirmative, the system proceeds to step 512 that determines which symbol to consider next. In the example above, the following symbol to consider is the pictorial entity symbol. The system then restarts at step 506 . In the event that all symbols for the current class have been processed, step 510 is answered in the negative and the system proceeds to step 514 . Step 514 checks if there are any classes remaining. In the affirmative the system proceeds to step 516 that determines which class to consider next. In the example above, the next class to consider is the “LIPS” class. The system then restarts at step 504 with the last symbol of the element code of the new class. In the event that all classes have been processed, step 514 is answered in the negative and the system proceeds to step 518 with the image data table including the complete description of the image described by the facial code. The image data table can then be used by the composite picture system to access the library of pictorial entities and image qualifiers 104 and produce a facial image.
[0047] As shown in FIG. 3, the image data 304 is stored in an image data table that can be accessed by an image builder unit 306 . The image builder unit 306 accesses the library of pictorial entities and image qualifiers 104 of the composite picture system to extract the pictorial entities specified by the image data. The image builder also extracts the image qualifiers specified by the image data and is operative to condition the pictorial entities on the basis of the these extracted image qualifiers. Following this the builder unit 300 outputs an image which may be displayed to the user of the composite picture system. Extracting data elements from a database on the basis of symbols is well known in the art to which this invention pertains.
[0048] In the event that the facial code comprises version number information, the reverse operation used to imbed the version number in the facial code is applied to the facial code during the decoding process. In a specific example where the version number information is integrated in the facial code by multiplying the code by a specific number, the decoding process involves dividing the facial code by that number.
[0049] In the event that characters in the facial code that may be visually confusing were replaced by non-alphanumeric characters, the reverse operation is performed on the facial code.
[0050] An example of a typical interaction will better illustrate the functionality of the encoding module implemented by the program instructions 102 of composite picture system and using the data components 104 106 .
[0051] In a typical interaction, as shown in FIG. 6 a, once the composite picture system is activated 600 , the user selects a set of pictorial entities 602 through a user interface. The interface to the composite picture system may be a keyboard, pointing device, touch screen or any other suitable input means. The received input may be an address of the memory location where a given pictorial entity is located or some other way of identifying it. The selection is entered in the image data table in association with corresponding qualifier symbols. Preferably, the pictorial entities in a given class as assigned default qualifier symbols. Once the system has received the request, the entries in the image data table are used to locate in the library of pictorial entities and image qualifiers, the entries corresponding with the received input. When pictorial entity or image qualifier is selected it is considered to be active. Following this, the selected pictorial entities and image qualifiers are combined to form a facial image. The combination is performed by positioning each active pictorial entity in a same frame at the location specified by the position qualifier in the image data table. The system then displays the facial image to allow the user to view it 604 . Alternatively, after each selection of a pictorial entity, the systems displays it to allow the user to view the image as it stands with the current selection of pictorial entities. At condition 606 , if the user is satisfied with the appearance of the facial image, the composite picture is complete 610 . The completeness of the image may be indicated by a user inputting a command indicative that the image is complete. The image data table is then processed by the encoding process to compute the facial code 612 . The user of the system may then make use of the facial image and facial code as he pleases. For example, the user may print the resulting facial image, he may store the image by storing the facial code computed at step 612 or he may transmit the image to an external site by transmitting the facial code. In the event that the user is not satisfied with the appearance of the facial image, condition 606 is answered in the negative and the user may modify the facial image 608 . The modification of the facial image may comprise different operations. For example, the user may replace a pictorial entity by another of the same class; he may remove a pictorial entity all together; the element may be displaced in the vertical or horizontal direction. In a specific example, the user interface may include a means, such as arrows in the user interface, for displacing the pictorial entities in the vertical and horizontal directions. The arrows may be linked to functional modules that modify the position of the selected image in the screen. When the pictorial entity is displaced, the corresponding position qualifier symbol in the image table is also modified such as to reflect to current positioning of the pictorial entity. The user may select via a pointing device or other input means the element he wishes to displace in the facial image. The user then uses the displacement arrows to position the pictorial entity in the desired position in the facial image. Many variations in the user interface are possible and implementations different from the one presented above do not detract from the spirit of the invention. For every modification performed in step 608 , the image data table is updated accordingly. Once the facial image has been modified by selecting a revised set of pictorial entities and image qualifiers, the latter are combined to form a facial image. The system then displays the facial image as described in the image data table to allow the user to view it at step 604 . Alternatively, after each selection of a pictorial entity or and image qualifier, the systems displays it to allow the user to view the updated image as it stands with the current selection. The process continues until the user is satisfied with the image and condition 606 is answered in the affirmative the system proceeds to step 610 .
[0052] As a variant, as shown in FIG. 6 b, the facial code may be computed incrementally as the user selects pictorial entities and image qualifiers and modifies the facial image. Following step 602 , the image data table is processed 652 by the encoding unit to compute the facial code corresponding to the data in the image data table. The facial image may then be modified in accordance with steps 604 606 and 608 described previously. Following step 608 , the image data table is reprocessed by the encoding unit 650 to compute the facial code corresponding to the updated data in the image data table. In this variant, the facial code for the image being created is computed as the user creates the image. Once the use stops entering new modifications, the code is readily computed without the need for the user to input a command indicative that the image is complete.
[0053] In another typical interaction, the composite picture system may receive as input the facial code describing a facial image. Using this facial code, the composite picture system reconstructs the facial image. Therefore, the user interface may also include a means for entering the facial codes. The facial code is first decoded by the process described in connection with FIG. 5. The decoding process produces an image data table containing information for generating the facial image. The system accesses the library of pictorial entities and image qualifiers and extracts the pictorial entities and image qualifiers corresponding to the data contained in the image data table. The image is then displayed to the user which may make use of it as he please by modifying it, storing it, printing it or transmitting it.
[0054] [0054]FIG. 7 shows an alternative embodiment of an apparatus including an embodiment of the invention. Such an apparatus comprises a user interface 706 such as a touch screen, mouse, keyboard are any other suitable input means for communicating with the user of the image system. The user interface communicates with an image builder unit 702 operative to generate graphical data on the bases of a given set of input data elements. The image builder unit may be implements on a general purpose computing platform running an application software of may be a dedicated CPU unit programmed specifically for the purpose of generating images. The Image builder unit 702 communicates with an output unit 704 such as a display unit or a printer unit to send the generated graphical data for output to the user. The image builder unit also communicates with a library of pictorial entities and image qualifiers 700 . The library of pictorial entities and image qualifiers 700 may be implemented on a computer readable medium such as a hard disk, CD-ROM, non-volatile RAM or any other suitable device. The image builder unit 708 also communicates with a computer readable medium including image data 708 . The image data specifies the pictorial entities that are active in the given image as well as any other relevant image qualifier such as position and zooming. The image data 708 may also be modified by the image builder unit 702 to update its entries on the basis of inputs received by the image builder unit 702 from the user through the user interface 706 . The image data 708 can be accessed by and encoder 710 operative to encode the image data according to the process described in this specification. The encoder may be implemented on a general purpose computing platform running an application software in accordance with the process described or may be a dedicated CPU unit programmed specifically for the purpose of encoding image data. The encoder 710 outputs the image code. The encoder may further communicate with a communication unit 716 such as a modem, network card or any other suitable communication devices suitable for transmitting data information over a communication channel 718 . The image data 708 can be accessed by a decoder 714 operative to decode an image code according to the process described in this specification. The decoder 714 may be implemented on a general purpose computing platform running an application software in accordance with the process described or may be a dedicated CPU unit programmed specifically for the purpose of decoding image codes. The decoder 714 outputs the image data that is inputted to the computer readable medium containing image data. The decoder may further communicate with the communication unit 716 in order to receive image codes. The encoder 710 and decoder 714 also communicate with a computer readable medium including element code factors 712 .
[0055] The facial code produced by the process described above allows each facial image to be described with a very small number of characters compared to a graphical representation permitting the rapid transmission of the composite picture over data transmission medium. For example, as shown in FIG. 8, a police station at site A 804 using an embodiment of the invention can transmit the entire composite picture of a suspect to police station at site B 802 by simply sending the facial code for that facial image either verbally or through an electronic communication means 800 . At the reception, police station at site B 800 enters the code into the composite picture system that displays the composite picture. The data transmission medium 800 between site A 802 and site B 804 may be a telephone line with a set of modems, and Ethernet connection, the Internet or any other communication medium suitable for the transfer of data. In the above example, site A 804 and site B 802 have on their local site a composite picture system of the type described in FIG. 1 or FIG. 7 of the drawings. A copy of the library of pictorial entities and image qualifiers is stored at each site and only the code needs to be transferred. Advantageously, the invention further allows the storage of a facial image by storing the facial code only on a computer readable medium. This may result in substantial savings in terms of memory requirements for storing the images since only a single instance of each pictorial entity and image qualifier needs he stored, the instance being in the library of pictorial entities and image qualifiers.
[0056] Although the present invention has been described in considerable detail with reference to certain preferred versions thereof, other versions are possible. For example, the method and apparatus described may be used in a system to encode a given image provided the image is build on the basis of constituent parts. In these types of application the library of pictorial entities and image qualifiers would include the appropriate set of pictorial entities and image qualifiers. Therefore, the spirit and scope of the appended claims should not be limited to the description of the preferred versions contained herein.
[0057] The reader's attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.
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The invention relates to a method and an apparatus for encoding images, more particularly to an encoding unit in conjunction with a library of pictorial entities and image qualifiers. The method and apparatus provide encoding an image by using a code factor table in conjunction with a set of element codes. The resulting image code allows the set pictorial elements of an image and their associated image qualifiers to be represented by a compact code uniquely representing a given configuration of pictorial elements. The use of the resulting image code facilitates the transmission and storage of images requiring only the code to be sent or stored. The invention further provides a computer readable medium comprising a program element that direct a computer to implement the encoding process.
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FIELD OF THE INVENTION
The present invention relates to a radar level gauge intended for measuring with a close-range low-power radar a distance to a surface of a content in a container relatively to a measuring position, which is located above the surface and fixed in relation to a lower boundary of said container.
BACKGROUND
Pulsed RLG (radar level gauging) is becoming a more widely spread method for industrial level gauging, due to its simple and cost effective microwave components. The pulse in a pulsed RLG can be modulated by a carrier frequency (typically 6 or 24 GHz), or be an unmodulated DC pulse. In the latter case, it is common to use some kind of transmission line (coaxial line, twin line, etc.), sometimes referred to as a probe, is usually used to guide the electro-magnetic signal through the material in the tank where it is reflected by one or more interface surfaces (such as air/liquid) between different parts of the tank content. In the former case a transmission line or wave guide can also be used, but generally an antenna is used to form a vertical radar beam which is reflected at possible interface surfaces.
Pulsed radars typically apply different types of directional coupling. An example of a directional coupler including high speed sampling capabilities is described in U.S. Pat. No. 5,517,198. Directional coupling divides the available power between transmission line and receiving line, thus introducing significant attenuation of both transmitted and received signals, degrading the sensitivity of the system. This is in particular a problem for systems using a DC pulse, since the choice of directional coupler is limited by the extreme bandwidth of such a pulse, which includes also large wavelengths.
For this and other reasons, pulsed systems therefore typically have lower sensitivity compared to frequency modulated continuous wave (FMCW) radar. The sensitivity (ability to detect weak reflections) is an important virtue for any RLG as a high sensitivity may enable the use of a smaller antenna or a longer transmission line, all other parameters held constant.
One way to provide a directional coupling without sensitivity losses is to use a circulator, such as a ferrite circulator. However, such solutions are expensive, and their performance is typically temperature dependent, making them unsuitable for use in radar level gauges.
SUMMARY OF THE INVENTION
It is an object of the present invention to cost efficiently improve the sensitivity of pulsed radar level gauge systems.
This and other objects are achieved by a RLG system according to the introduction, comprising a power supply interface for receiving electrical power to said radar level gauge, a communication interface for presenting externally of said radar level gauge information based on said distance, a transmitter for generating and transmitting an electromagnetic transmitter pulse, a signal medium interface connectable to means for directing said transmitter pulse towards said surface and for receiving a reception pulse reflected back from said surface, a fastening structure for securing said signal medium interface in said measuring position, receiver for receiving said reception pulse, a switch enabling connection of said transmitter and said receiver, respectively, with said signal medium interface, and controller circuitry for controlling the operation of said switch and for determining said distance, said switch being adapted to connect said signal medium interface to said transmitter while said transmitter pulse is transmitted, and to connect said signal medium interface to said receiver while said reflected pulse is received, said switch having a switching time short enough to enable short distance detection.
According to this design, the directional coupler, that previously was arranged between the transmitter and the signal medium interface, has been replaced by a switch. By controlling the switch, the signal medium interface is connected only to the transmitter during the transmission of the pulse, and only to the receiver during reception of the reflected pulse. In this way, signal losses can be reduced significantly compared to prior solutions, where the signal medium interface at all times was connected to both the transmitter and the receiver. Typically, 10 dB improvements have been experienced, which for practical hardware solutions may correspond to 2–3 times longer maximum measuring distance for an antenna system, or maybe 20 meters longer maximum measuring distance for a transmission line system.
By this design, all power of the transmitted pulse will be guided to the tank, at the same time as all power of the reflected pulse will be directed to the receiver. As mentioned, conventional transmission line systems use some kind of power splitter, reducing the amplitude by 50% in each direction, typically resulting in 6+6 dB attenuation compared to the invention.
The switching time of the switch is short enough to enable short distance detection. A radar level gauge typically measures distances in the range from up to several tenths of meters down to fractions of a meter, sometimes only a few centimeters.
A conceptually different solution, implemented with a switch instead of e.g. a directional coupler, is known from more traditional pulse radar, e.g. surveillance radar at sea. Here, the switch is used to switch between transmission of relatively high power signals (kW or MW) and reception of the much weaker radar reflections. These high power signals make it necessary to include even further attenuation between the switch and a receiver circuitry in order not to risk damaging the receiver circuitry. Further, as the switch must be designed to handle the relatively high power levels, it will, as a consequence, be relatively slow. The switching time of such a switch causes a considerable dead zone (in which the distance to be measured is to short to be recorded by the radar), i.e. the distance covered by signal during the time required to switch the switch, typically in the order of ten meters. As such dead zones are completely unacceptable in the field of radar level gauging, such solutions have been considered as unrealistic in this field. According to the invention, however, a system with an acceptable dead zone has been realized.
In order to obtain a sufficiently short dead zone, the switch should have a very short switching time, in the order of ns. Preferably, the switching time is shorter than 20 ns. Such a short switching time can only be realized by a switch without moving parts, comprising very small scale components, either discrete components or in the form of an integrated circuit, and this limited size of the switch makes it unable to handle powers greater than a few Watts. However, in a typical RLG system, the transmitted power is significantly less than one Watt, preferably less than 20 mW, and normally limited to a few mW, or even μW. Thus, the limited power capacity of the switch is not a problem.
In the inventive RLG, it is advantageous to provide for a small signal attenuation between the switch and the receiver, in order to provide higher signal input strength to the receiver for enhancing measuring capability. This RLG should preferably include no significant further attenuation/isolation between the transmitter and receiver than that introduced by the switch itself.
The controller circuitry can be adapted to detect when a pulse is transmitted from the transmitter, and in response to said detection, operate the switch to connect the signal medium interface to the receiver.
Preferably, the controller circuitry is further arranged to operate the switch to again connect the interface to the transmitter after a predetermined period of time. Typically, this period should be shorter than the time between transmission of consecutive pulses from the signal generator.
The controller circuitry is preferably adapted to control the operation of said switch so as to allow determining a value of said distance less than one half of a meter.
In order to ensure that no reflection pulse reaches the switch before it has been switched over to the receiver, the radar level gauge can further comprises a delay feed line between the switch and the signal medium interface. Such a delay feed line can be accomplished e.g. by a coaxial cable of a certain length or conductive patterns on a printed circuit board. The signal time delay between said microwave switch and said signal medium interface preferably allows determining a value of said distance less than one meter, or less than one half a meter. The signal time delay can be equal to or greater than half of a switching time of said switch.
If a satisfactory switching time can be obtained, the switch can be adapted to realize pulse generation, by connecting the signal medium interface to a DC voltage for a period of time equal to the desired pulse width and then disconnecting it. Such operation of the switch will eliminate the need for a separate signal generator, thus simplifying the system.
If the switch has an adequate switching time, it may also be used to realize sampling, or at least pre-sampling, of the reflected signal.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other aspects of the present invention will be described in more detail with reference to the appended drawings, illustrating presently preferred embodiments.
FIG. 1 shows schematically a radar level gauge system.
FIG. 2 shows a section view of another radar level gauge system.
FIG. 3 shows a block diagram of a transceiver according to a first embodiment of the invention.
FIG. 4 shows a block diagram of a transceiver according to a second embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows schematically a radar level gauge (RLG) system 1 in which a method according to the invention may be advantageously used. The system 1 is arranged to perform measurements of a process variable in a tank, such as the level of an interface 2 between two (or more) materials 3 , 4 in the tank 5 . Typically, the first material 3 is a content stored in the tank, e.g. a liquid such as gasoline, while the second material 4 is air or some other atmosphere. In that case, the RLG will enable detection of the level of the surface of the content in the tank. Note that different tank contents have different impedance, and that the electromagnetic waves will not propagate through any material in the tank. Typically, therefore, only the level of a first liquid surface is measured, or a second liquid surface if the first liquid is sufficiently transparent.
The system 1 comprises a transceiver 10 , controlled by a processor 11 to transmit electromagnetic signals to a signal medium interface 12 in the tank 5 . The signals can be DC pulses with a length of about 2 ns or less, with a frequency in the order of MHz, at average power levels in the mW or μW area. Alternatively, the pulses can be modulated on a carrier wave of a GHz frequency.
In the case illustrated in FIG. 1 , where the signals are DC pulses, and in some case also when modulated pulses are used, the signal medium interface 12 is connected to a wave guiding structure 6 extending into the content of the tank. The wave guiding structure can be a hollow wave guide or some sort of probe, such as a coaxial wire probe, a twin wire probe, or a single wire probe (also referred to as a surface wave guide). Electromagnetic waves transmitted along the structure 6 will be reflected by any interface 2 between materials in the tank, and the reflection will be transmitted back to the signal medium interface 12 .
Alternatively, as shown in FIG. 2 , and as is normally the case where the pulse is modulated on a high frequency carrier wave, the signal medium interface 12 is connected to a radar antenna 7 , arranged to emit the transmitted waves to freely propagate into the tank, and to receive waves that are reflected by any interface 2 between materials in the tank.
As shown in FIG. 2 , the tank can be provided with a fastening structure 8 securing the signal medium interface 12 in a measuring position fixed relative the bottom of the tank 5 . The fastening structure is preferably coupled to a feed through structure 9 in the upper boundary of the tank 5 . As shown in FIG. 2 , this feed through structure 9 can be wave guide provided with a gas tight sealing 14 capable of withstanding temperature, pressure, and any chemicals contained in the tank.
A reflection pulse received by the signal medium interface is fed back to the transceiver 10 , where it is sampled and digitalized in a process controlled by the processor 11 . A digitalized, sampled time domain reflectometry (TDR) signal 15 based on the reflected signal is communicated back to the processor 11 . The signal 15 can be expanded in time, allowing for use of conventional hardware for conditioning and processing.
The processor 11 is provided with software for analyzing the TDR signal in order to determine a process variable in the tank, typically the level of the surface 2 . The processor 11 is further connected to a memory 16 , typically comprising a ROM (e.g. an EEPROM) for storing pre-programmed parameters, and a RAM for storing additional software code executable by the microprocessor 11 . The processor can also be connected to a user interface 17 .
FIG. 3 shows the transceiver 10 in FIG. 1 in greater detail. The signals are transmitted by a transmitter here in the form of a pulse generator 21 , and received by the sample and hold circuit 22 of a receiver 23 . The receiver 23 further comprises an amplifier 24 and an A/D-converter 25 . A microwave switch 26 is provided to connect the signal medium interface 12 in the tank to either the transmitter 21 (state A) or the receiver 23 (state B).
In the illustrated example, the switch is a microwave monolithic IC (MMIC), here a single pole, double throw (SPDT) switch, having a switching time of around 10 ns. An example of such a switch is the HMC197 from Hittite Microwave Corporation. Other types of switches may be used, both formed as an IC and comprising discrete components.
The switch 26 is controlled by controller circuitry which can be implemented as a separate controller 27 , as indicated in FIG. 2 , or be implemented directly in the processor 11 . The pulse generator 21 , sample and hold circuit 22 and controller 27 are all provided with oscillation signals 28 , 30 from the processor 11 . The output 15 of the A/D-converter is fed back to the processor 11 .
The operation of the transceiver 10 will be described in the following.
The transmitter 21 generates pulses with a duration in the order of ns, here 1 ns, with a frequency in the order of MHz, here 2 MHz. For this purpose, the transmitter is provided with a high frequency (e.g. 2 MHz) clock signal 28 . Each pulse is transmitted to the signal medium interface 12 via the switch 26 , which is in state A. As mentioned, the clock signal 28 is also supplied to the controller 27 , which is triggered to provide a switching signal 29 to the switch 26 at the same time as a pulse is generated by the pulse generator. After a time period corresponding to the switching time of the switch 26 , typically much longer than the pulse itself, the switch 26 is thus switched to state B, connecting the signal medium interface 12 to the receiver 23 .
During the time after the pulse is generated, but before the switch 26 has been switched to state B, the receiver will be unable to receive any signals (resulting in a blind zone or dead zone). In order for reliable operation of the system, it is desirable that no reflected signal reaches the switch 26 during this blind zone, and the switching time is preferably made as short as possible. With components available at the time of the invention, a switching time of 10 ns was considered sufficiently short and reasonably cost efficient.
The transmitter pulse is guided to the signal medium interface 12 in the tank, and is then directed towards the surface 2 by a wave guiding structure (as shown in FIG. 1 ) or by an antenna (as shown in FIG. 2 ). The electromagnetic waves are reflected against the surface 2 , and a reception pulse is returned to the signal medium interface, and via switch 26 connected to the receiver 23 . The sample and hold circuit 22 samples the signal, using an oscillation signal 30 (e.g. in the order of 2 MHz) received from the processor 11 . The signal is then amplified by amplifier 24 and digitalized by A/D-converter 25 . The result, a time domain reflectometry (TDR) signal 15 , is supplied to the processor 11 , where it is analyzed by suitable methods to determine a process variable, such as the level of the surface 2 in the tank.
In a case where the switching time of the switch 26 is deemed too long in relation to the expected arrival time of the reception pulse, a delay feed line 13 can be provided between the switch 26 and the signal medium interface 12 in the tank. This delay feed line can be adapted to delay the reception pulse from the tank, thus allowing for a slower switch. The delay feed line 13 can be realized by e.g. a coaxial cable, or a pattern on a printed circuit board. Typically, the extra delay provided by such a delay feed line is in the order of the switching time of the switch 26 , and as an example, a 2–3 m long section of coaxial cable would allow for a switching time around 20 ns.
The controller 27 is adapted to return switch 26 to state A (again connecting the signal medium interface 12 to the transmitter 21 ) after a predetermined period of time, not exceeding the time between consecutive pulses. Here, where the pulse frequency is 2 MHz (time between pulses 500 ns), the controller is thus set to switch the switch back to state A after less than 500 ns. Depending on the application, it may be advantageous to keep the switch in state B for as long as possible, in which case the period is close to the time between pulses (here 500 ns). Alternatively, however, the period is set much shorter, and may for example be only around half of the time between pulses. The controller 27 can employ an internal timer to determine when to switch back to state A, or it can use the clock signal 28 .
An alternative embodiment is shown in FIG. 4 , where elements identical to the elements in FIG. 3 have been given identical reference numerals. The pulse generator has here been omitted, and the clock signal 28 is connected only to the controller 27 ′, which controls the switch 26 ′ to act as a transmitter. The A terminal of the switch is connected to a DC voltage.
During operation, the switch 26 ′ is kept in state B for most of the time. At the arrival of a clock pulse on line 28 , the switch is switched to state A, connecting the DC voltage to the signal medium interface 12 . The controller is then adapted to immediately switch the switch back to state B, resulting in a DC pulse transmitted to the signal medium interface 12 , this pulse having a pulse width equal to the switching time of the switch.
In order to make this embodiment realistic, the switch should be faster than the 10 ns mentioned above, and should typically be in the order of 1 ns, in order to provide pulses with the desired pulse width.
As an additional aspect of the inventive concept, the switch 26 can be used to perform sampling of the reflected signal. Depending on the switching time of the switch 26 , such sampling may be combined with that of the sample and hold circuit 22 , or, with a sufficiently fast switch 26 , completely eliminate the circuit 22 from the design. Such a sampling function of the switch 26 would also be controlled by the controller 27 , which should be adapted to connect the receiver 23 to the signal medium interface 12 intermittently, so that each connection instant corresponds to one sample.
It should be noted that a number of variations of the above described embodiments are possible within the scope of the appended claims. For example, all the components of the radar level gauge system described above are not compulsory, but may be excluded or substituted. Also, additional components may be included if and when deemed advantageous. Other types of switches than the above described may be used to realize the invention, as long as they have a satisfactory switching characteristics.
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A radar level gauge (RLG), intended for measuring with a close-range low-power radar a distance to a content surface in a container relatively to a measuring position, which is located above the surface and fixed in relation to a lower boundary of said container. The RLG comprises a transmitter for transmitting an electromagnetic transmitter pulse, a signal medium interface connectable to means for directing said transmitter pulse towards said surface and for receiving a reception pulse reflected back from said surface, and a receiver for receiving said reception pulse. A switch connects said signal medium interface to said transmitter while said transmitter pulse is transmitted, and said signal medium interface to said receiver while said reflected pulse is received, the switch having a switching time short enough to enable short distance detection.
According to this design, signal losses can be reduced significantly compared to prior solutions.
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FIELD OF THE INVENTION
The present invention relates to methods and systems for protecting a person's. More specifically, the invention relates to methods and systems that employ a computer network which automatically processes, stores and manages a person's identity at the request of the user and protects that identity in transactions.
BACKGROUND OF THE INVENTION
Identity theft has become a growing epidemic in the United States and in the rest of the world. Many people have become victim to identity theft which resulted in the loss of money, time, credit and privacy. The incidence of identity theft increased 20% in 2001-2002 and 80% in 2002. Identity theft costs individuals and businesses billions of dollars each year. Yet there is no method or system to stop it.
Nearly 85% of all victims find out about their identity theft case in a negative manner. Only 15% of victims find out due to a proactive action taken by a business. The average time spent by victims is about 600 hours, an increase of more than 300% over previous studies. And it is taking far longer to eliminate negative information from credit reports. The emotional impact of identity theft has been found to parallel that of victims of violent crime.
In 2003, the Federal Trade Commission (FTC) found that over twenty-seven million Americans had been victims of identity theft in the previous five year, including approximately ten million people, or 4.6% of the population, in 2002.
In 2002, over three million consumers or 1.5% of the population discovered that new accounts had been opened, and other frauds such as renting an apartment or home, obtaining medical care or employment, had been committed in their name. Over six million had experienced their existing accounts compromised by an identity theft. A staggering ten million individuals were victims of identity theft.
Fifty-two percent of all ID theft victims, approximately 5 million people in the last year, discovered that they were victims of identity theft by monitoring their accounts.
In 2002, identity theft losses to businesses and financial institutions totaled over forty-seven billion dollars and consumer victims reported five billion dollars in out-of-pocket expenses. In those cases, the loss to businesses and financial institutions was $10,200 per victim totaling $32.9 billion. Individual victims lost an average of $1,180 for a total of $3.8 billion.
Where the thieves solely used a victim's established accounts, the loss to businesses was $2,100 per victim totaling $14.0 billion. For all forms of identity theft, the loss to business was $4,800 and the loss to consumers was $500, on average.
The major concern of identity theft is the ease with which it occurs. Typically, identity thieves obtain the Social Security number and name of an individual. That's often all that is needed for identity theft. In addition, they also might obtain credit card numbers and hijack existing accounts. Other pieces of information useful to identity thieves are dates of birth, mother's maiden name, and driver's license number.
Many of these pieces of information can be obtained by simply stealing a person's wallet or going through a person's garbage. In addition, many identity thieves are going through the internet and obtaining the information needed to obtain a person's identity. Many internet sites require registration which includes personal information.
Furthermore, these companies and organizations collect the information and store the information in a database that could be sold or traded to other entities. As time goes on, a person's personal information could be obtained by hundreds of businesses and entities. A hacker or disgruntled employee may at any point obtain that information for the purpose of identity theft.
In addition to online identity theft, the use of credit cards at merchant stores is another avenue of identity theft. In providing credit card information, the credit card holder also provides the name, billing address, and other information an identity thief can use to assume someone's identity.
There are many forms of identify theft, the most common form of identity theft is financial identity theft. This is when someone obtains the Social Security number (SSN) and perhaps a few other pieces of information about an individual, and uses that information to impersonate them and obtain credit in their name. The imposter might apply for credit, rent an apartment, get phone service, buy a car—and then not pay the bills, giving the victim a bad credit rating. Victims must then spend months and typically years regaining their financial health.
Another form of identity theft is criminal identity theft. Here, the imposter in this crime provides the victim's information instead of his or her own when stopped by law enforcement. Eventually when the warrant for arrest is issued it is in the name of the person issued the citation—yours.
Yet another form of identity theft is identity cloning. In this crime the imposter uses the victim's information to establish a new life. They work and live as you. Examples: Illegal aliens, criminals avoiding warrants, people hiding from abusive situations or becoming a “new person” to leave behind a poor financial history.
Finally, there is business or commercial identity theft. Businesses are also victims of identity theft. Typically the perpetrator gets credit cards or checking accounts in the name of the business. The business finds out when unhappy suppliers send collection notices or their business rating score is affected.
Currently, there exists no efficient process eliminate identity theft from occurring. In fact, there exists very few and limited laws to protect consumers from identity theft. From a legislative perspective, one of the main problems is that no federal law governs—or even limits—the use or disclosure of someone's SSN among private entities. This leaves private companies free to deny anyone credit, service or membership for refusing to furnish a SSN. Simultaneously, and contrary to popular belief, the Social Security Administration has no power to control how private entities use their account numbers.
The result is an extremely vulnerable system that puts the entire burden of protection on the consumer. With no power to control how their SSN is kept, used or distributed, many are left simply to sit and wait for an ID thief to strike.
Unfortunately, there is a gaping hole under existing law for preventing ID theft schemes. Although fraudulently using an individual's identity information is a crime, the after-the-fact approach currently in place does little to protect consumers from identity theft before it occurs.
Current identity theft “solutions” offer help to consumers after the crime has occurred. Businesses—typically credit agencies—offer identity theft insurance which include monetary reimbursement for financial losses, time lost, and attorney's fees. These businesses and entities also offer legal assistance or guidelines for the consumer in obtaining his or her identity back and to stop the use of their identity by others. There are no businesses or entities that offer services to individuals to help protect them from identity theft before it occurs.
Further, an individual voluntarily gives out their personal data in the course of the day: from registering internet domains to obtaining credit to purchasing items over the internet, in person, or by phone. To function in society, one must provide this information.
Once a person's personal information is out there, there is no getting it back. Many companies share information and data and, as a result, we are continually bombarded by spam, mail solicitations, numerous marketing calls and all other unwanted contacts by organizations simply because, at some point, we wanted to buy something!
In short, it would be an advancement in the art of privacy protection to provide methods and systems which would greatly reduce the act of identity theft as well as other forms of annoyances caused by the release of a person's personal information, while maintaining the confidentiality and security of the individual. More specifically, to control a person's identity while using the internet, credit card, or in any transaction in which a person's identity might be obtained.
SUMMARY OF THE INVENTION
The above-mentioned needs are encompassed in the present invention in which processes and systems, and software implementing these processes, greatly protect a person's identity. Typical individuals provide personal data in many situations as stated previously. In many cases, in order to conduct business or to apply for a service, an individual must provide his personal data. The present invention greatly reduces the harm from providing such personal data, such harm as identity theft, unwanted marketing calls, spam, and so on.
The processes and systems according to the present invention are advantageously implemented using a plurality of computers and/or servers that communicate together, typically a computer network or system. In some cases, human assistance may be necessary to facilitate the process and system.
The inventive processes and systems that enable a requester to obtain a secondary identification employ one or more centralized data processing centers, comprising one or more computers or computer systems, in communication with remote computers or computer systems employed by the various requesters. The data processing center is also in electronic communication with providers from whom a secondary identification is to be requested. To help ensure compliance, the data processing center may electronically communicate with one or more telephone calling centers that employ individuals assigned to contact a specific requestor while that requestor receives an electronic communication from the data processing center. The data processing center may also be in electronic communication with a data conversion device, such as a scanner or fax machine, used to convert a paper record into an appropriate electronic form.
The inventive processes and systems generally include four basic steps and subsystems. First, a request for a secondary identification electronically received from a requester by a data processing center. Second, the data processing center electronically transmits the request to the appropriate subsystems. Third, the sub-systems produce a secondary identification. Fourth, the data processing center matches up the secondary identification with the primary identification and the corresponding request, creates a copy of the secondary identification, and transmits the copy of the secondary identification to the requester via a secured connection.
In the first step and subsystem, the initial request from the requester to the data processing system is typically generated by means of a computerized request form using software designed to generate standard forms for that requester. As the request form is generated, a request identification code, such as a serial number, is generated for each request. After the data processing center receives the request, it performs sub-processes to create a secondary identification.
In the second step and subsystem, the data processing center transmits each request to the one or more of the requested services such as the secondary email, secondary postal mail and secondary phone services.
The data processing center may also transmit the request to a quality control center at or about the same time it transmits the request to the services, if needed. A designated individual within the quality control center then places a telephone call to, or otherwise initiates communication with the service, preferably to an individual in close proximity to the computer, fax machine or other device that receives the request.
In the third step and subsystem, the secondary identification is created by sub-processes as described below. The sub-processes include but are not limited to the creation of a secondary identification of a secondary postal address, the creation of a secondary email address, and the creation and obtaining a secondary phone number. In the above-mentioned sub-processes, one or more than one may be requested by the requester. The data processing center communicates with the requester in obtaining and managing the secondary identification, and associating the requestor's actual or primary identification and the secondary identification.
Further, the data processing center also will store the requestor's primary identification and secondary identification in a secure network to protect the information from outside tapping. In addition, the database created will be accessible to government agencies as required by law via secure connection.
In the fourth step, the data processing center transmits an electronic or facsimile copy of the requested secondary identification to the requester.
In one embodiment of the present invention, the secondary identification will be created for the requestor for purposes of protecting the requestor's identity from identity thieves and spammers. The requester, while surfing the internet, will be protected from unwanted advertisement, spam, and solicitation to their email address, home address and/or phone. The communications, spam or solicitations by electronic means will be sent to the requestor's secondary email address, which will be automatically forwarded to the requestor's primary email address or deleted. At the requestor's choosing, a new secondary email account may be created and the previous secondary email terminated. The purpose of the above is to protect the requestor's email address from the flooding of his primary email address once his secondary email address has been compromised. Further, all communications, solicitations and/or junk mail sent by postal mail or express mail service will be sent to the requestor's secondary postal address at a post office box. The requester may request the mail to be forwarded to his primary postal address or to be discarded or to be scanned and forwarded to his primary email address. Finally, any phone communication and/or solicitation will be sent to the requestor's secondary phone number which will consist of a voicemail system that will be accessible by the requester, or, if the requestor so chooses, to be forward via wave file or similar format to the requestor's primary email address, or deleted.
In another embodiment of the present invention, the above discussed components will be used in the issuance of a credit card or privacy credit card. A requester may choose to obtain a credit card with privacy protection, the requestor's primary identification is sent to a credit issuing-bank in which the requestor is either approved or rejected for credit. If the requestor is approved for credit, the requestor is issued with a credit card. Concurrently, the requester is given a secondary identification as discussed above. Once a requestor's secondary identification is created, the data processing center swaps the requestor's primary identification with the secondary identification in the issuing bank's database. If the issuing bank's database is programmed to store both the secondary identification and primary identification, then both will be stored with the bank. Otherwise, the issuing bank will store the secondary identification with access to the data processing center to obtain the requestor's primary identification.
In addition, the credit card will consist of a transaction privacy feature in which the monthly statement will be sent by electronic means with the option of either only disclosing the total sum due or all transactions in the billing period. The requestor may enter into his credit card account and obtain the transaction history of his credit card for any billing period. The purpose of this feature is to obtain privacy in the requestor's transactions from other sources.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by the practice of the invention. The features and advantages of the invention may be realized and obtained by means of the instruments and combinations particularly pointed out in the appended claims. These and other features of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth below.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates an exemplary system that provides a suitable operating environment for the present invention;
FIG. 2 is a schematic diagram illustrating the exemplary system or network for processing requests for a secondary identification according to the invention;
FIG. 3 is a flow diagram depicting an exemplary process by which requests for a secondary identification may be processed;
FIG. 4 is a flow diagram depicting an exemplary sub process for generating and obtaining a secondary address and mailbox;
FIG. 5 is a flow diagram depicting an exemplary sub process for generating and obtaining a secondary email address;
FIG. 6 is a flow diagram depicting an exemplary sub process for generating and obtaining a secondary phone number;
FIG. 7 is a schematic diagram illustrating the exemplary system or network for processing requests for credit according to the invention;
FIG. 8 is a flow diagram depicting an exemplary process which requests for credit may be processed.
DETAILED DESCRIPTION OF THE INVENTION
In the following detailed description and in several figures of the drawings, like elements are identified with like reference numerals.
I. Introduction and Definitions
The present invention relates to processes and systems for requesting and obtaining a secondary identification (2 nd ID), as well as software for implementing these processes. Such processes and systems greatly streamline the ability to obtain a secondary identification on behalf of a requester. The process and systems according to the present invention are advantageously implemented using a set of computers which communicate together, typically a computer network or system. Such communication may be by direct link, by the Internet, or a combination thereof.
Some of the tasks may require human assistance to locate, process, and send certain information, which is then further processed by means of the computer network, typically a data processing center.
The term “data processing center” shall refer to a computer system that is essentially a computerized clearing house for receiving and processing requests, communicating the requests with other entities, receiving data, and then sending information to one or more parties authorized to receive the information. The data processing center may be located at a single location or constitute a system of computers at different locations that are networked together. While preferably computerized and automated as much as possible, the functions carried out by the data processing center may require some human intervention.
The term “requester” shall refer to any party that is making a request for a secondary identification or a privacy card. There is, however, no restriction as to who may constitute a “requester”. Thus, the requester may be the party actually making the request, or an employee, agent, or affiliate of the requesting party.
The term “issuing bank” shall refer to any individual or entity that may issue a credit card.
The term “access to”, in the context of a provider having “access” to a record, shall refer to any situation in which an agency has or may obtain access to a requested primary identification. Access may be actual or prospective.
II. Systems for Requesting and Providing a Secondary Identification
A. Basic Operating System.
The present invention extends to methods and systems for requesting and obtaining a secondary identification and/or a privacy credit card. By way of general background, the embodiments of the present invention may comprise or be implemented, at least in part, using special purpose or general purpose computers including various computer hardware, as discussed in greater detail below.
Embodiments within the scope of the present invention also include computer-readable media for carrying or having computer-executable instructions or data structures stored thereon. Such computer-readable media can be any available media that can be accessed by a general purpose or special purpose computer. By way of example, and not limitation, such computer-readable media may include random access memory (RAM), read only memory (ROM), electrically erasable programmable read only memory (EEPROM), compact disc read only memory (CD-ROM), digital video disc (DVD), or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to carry or store desired program codes in the form of computer-executable instructions or data structures and which can be accessed by a general purpose or special purpose computer. When information is transferred or provided over a network or another communications connection (either hardwired, wireless, or a combination of hardwired or wireless) to a computer, the computer properly views the connection as a computer-readable medium. Thus, any such connection is properly termed a computer-readable medium, as would be any medium for transmitting a propagated signal. Combinations of the above should also be included within the scope of computer-readable media. In addition to computer-readable media, computer-executable instructions or data structures may be partly or wholly provided to or sent from a computer in the form of a propagated wave, typically by means of one or more communications connections between two or more computers. Computer-executable instructions comprise, for example, instructions and data which cause a general purpose computer, special purpose computer, or special purpose processing device to perform a certain function or group of functions.
FIG. 1 and the following discussion are intended to provide a brief, general description of a suitable computing environment in which the invention may be implemented. Although not required, the invention will be described in the general context of computer-executable instructions, such as program modules, being executed by computers in network environments. Generally, program modules include routines, programs, objects, components, data structures, etc., that perform particular tasks or implement particular abstract data types. Computer-executable instructions, associated data structures, and program modules represent examples of the program-code means for executing steps of the methods disclosed herein. The particular sequences of such executable instructions or associated data structures represent examples of corresponding acts for implementing the functions described in such steps.
Those skilled in the art will appreciate that the invention may be practiced in network computing environments with many types of computer system configurations, including personal computers (PCs), hand-held devices, multi-processor systems, microprocessor-based or programmable consumer electronics, networked PCs, minicomputers, mainframe computers, and the like. The invention may also be practiced in distributed computing environments where tasks are performed by local and remote processing devices that are linked (either by hardwired links, wireless links, or by a combination of hardwired or wireless links) through a communications network. In a distributed computing environment, program modules may be located in both local and remote memory storage devices.
With reference to FIG. 1 , an exemplary system for implementing the invention includes a general purpose computing device in the form of a conventional computer system 10 , which, in its broadest sense, includes components hardwired or otherwise associated together within a conventional computer box, bundle, or subsystem illustrated by item number 12 , together with user interface, communications, and other devices and features located externally to, physically separated from, or otherwise spaced apart relative to the computer bundle or subsystem 12 . By way of example, and not limitation, a conventional computer bundle or subsystem 12 includes a processing unit 14 , a system memory 16 , and a system bus 18 that couples various system components including the system memory 16 to the processing unit 14 . The system bus 18 may be any of several types of bus structures including a memory bus or memory controller, a peripheral bus, and a local bus using any of a variety of bus architectures. The system memory includes read only memory (ROM) 20 and random access memory (RAM) 22 . A basic input/output system (BIOS) 24 , containing the basic routines that help transfer information between elements within the computer system 10 , such as during start-up, may be stored in ROM 20 .
The computer system 10 , typically the computer bundle or subsystem 12 , may also include a magnetic hard disk drive 26 for reading from and writing to a magnetic hard disk 28 , a magnetic disk drive 30 for reading from or writing to a removable magnetic storage device 32 , and an optical disk drive 34 for reading from or writing to a removable optical disk 36 such as a CD-ROM, digital versatile disk, a laser disk, or other optical media. The magnetic hard disk drive 26 , magnetic disk drive 30 , and optical disk drive 34 are connected to the system bus 18 by a hard disk drive interface 38 , a magnetic disk drive-interface 40 , and an optical drive interface 42 , respectively. The drives and their associated computer-readable media provide nonvolatile storage of computer-executable instructions, data structures, program modules, and other data for the computer 10 . Although the exemplary environment described herein employs a magnetic hard disk 28 , a removable magnetic disk 32 , and a removable optical disk 36 , other types of computer readable media for storing data can be used, including magnetic cassettes, flash memory cards, Bernoulli cartridges, RAMs, ROMs, and the like. For purposes of the specification and the appended claims, the term “computer readable medium” may either include one or a plurality of computer readable media, working alone or independently, so long as they singly or collectively form part of a recognizable system for carrying out the processes of the invention.
Program code comprising one or more program modules may be stored on the hard disk 28 , magnetic disk 32 , optical disk 36 , ROM 20 , or RAM 22 , including an operating system 44 , one or more application programs 46 , other program modules 48 , and program data 50 . A user may enter commands and information into the computer bundle or subsystem 12 by means of a keyboard 52 , a pointing device (e.g., “mouse”) 54 , or other input devices (not shown), such as a microphone, joy stick, game pad, satellite dish, scanner, video player, camera, or the like. These and other input devices are often connected to the processing unit 14 through a serial port interface 56 coupled to the system bus 18 . Alternatively, these and other devices 58 may be connected by other interfaces 60 , such as a parallel port, a sound adaptor, a decoder, a game port or a universal serial bus (USB). Non-exhaustive examples of “other devices 58” include scanners, bar code readers, external volatile and nonvolatile memory or storage devices, audio devices, video devices, and microphones. A monitor 62 or another display device is also connected to the system bus 18 via an interface, such as a video adapter 64 . In addition to the monitor 62 , computers typically include other output devices (generally depicted as “other devices 58”), such as speakers and printers.
The computer system 10 may operate in or involve a networked environment using logical connections to one or more remote computers, such as remote computers 64 a and 64 b . Remote computers 64 a and 64 b may each be another personal computer, a server, a router, a network PC, a peer device or other common network node, and typically include many or all of the elements described above relative to the computer system 10 , although only memory storage devices 66 a and 66 b and their associated application programs 68 a and 68 b have been illustrated in FIG. 1 . The logical connections depicted in FIG. 1 include a local area network (LAN) 70 and a wide area network (WAN) 72 that are presented here by way of example and not limitation. Such networking environments are commonplace in office-wide or enterprise-wide computer networks, intranets, and the global computer network or “Internet”.
When used in a LAN networking environment, the computer bundle or subsystem 12 is connected to the local network 70 through a network interface or adapter 74 . When used in a WAN networking environment, the computer bundle or subsystem 12 may include a modem 76 , a wireless link, or other means for establishing communications over the wide area network 72 , such as the Internet. The modem 76 , which may be internal or external, is typically connected to the system bus 18 via the serial port interface 56 . In a networked environment, program modules depicted relative to the computer bundle or subsystem 12 , or portions thereof, may be stored in a remote memory storage device (e.g., remote storage devices 66 a and 66 b ). It will be appreciated that the network connections shown are exemplary, and other means of establishing communications over wide area network 72 may be used.
Although computer components are commonly arranged in the form depicted in FIG. 1 , with some components of the computer system 10 physically located within, and other components physically located outside, the computer bundle or subsystem 12 , it will readily be appreciated that the terms “computer” and “computer system” should be broadly understood to include any or all of the foregoing components in any desired configuration which facilitate carrying out the inventive methods and systems disclosed herein. The terms “computer” and “computer system” may therefore include other common features or components not depicted in FIG. 1 .
In addition to the foregoing computer system, the inventive networks may include components such as fax machines, scanners, printers, copy machines and any other device or component that may be necessary to facilitate the retrieval and copying of the requested records. One level of human intervention may also be necessary to process or carry out certain steps such as entering into a transaction between the requester and the person authorizing the release of the records, signing of the authorization form by the client or other authorized person, one or more agents of the provider who receives and processes the request for the record, and the person who ultimately reviews the record to determine whether the transaction dependant on the record should go forward. To help ensure compliance, one or more calling centers in communication with the data processing center may be assigned the task of initiating a personal communication, such as a telephone call, with a representative of the provider that has access to the requested record. In short, the exemplary descriptions of computer systems and other hardware are given by way of example only and not by limitation.
B. The Data Processing Center.
The systems according to the present invention for requesting, obtaining, and providing a secondary identification are controlled or directed by one or more data processing centers in communication with one or more postal centers, one or more phone companies, one or more email service providers, optionally, one or more call centers. The centralized function or role of the data processing center according to the present invention is illustrated in FIG. 2 .
As depicted in FIG. 2 , a system for processing requests for a secondary identification according to the present invention includes, as its main information and control hub, one or more data processing centers 102 . The data processing center 102 is substantially or wholly automated by means of one or more computer systems that are able to receive and analyze information, make decisions, and send information as needed to carry out the processes disclosed herein. The data processing center 102 is in communication with one or more requesters 104 , and one or more providers 200 . The data processing center 102 may include any hardware peripheral to the computer system that will facilitate the process of requesting, obtaining, and providing a secondary identification. The data processing center 102 may involve human intervention to carry out one or more of the tasks described herein.
In a typical scenario, a requester 104 enters a request which requires the obtaining, processing, and delivery of a secondary identification to the requester. For the requestor to obtain a secondary identification, the requestor must provide his personal identification such as name, postal address, and/or email address. The means for generating and sending the request will typically include a computer, or one or more optional devices such as a printer, an electronic signature device, a fax machine, a scanner and the like.
The request is typically generated and sent in electronic form, such as in the form of a hypertext markup language (HTML) document or by means of an application program interface (API), discussed more fully below. The request 150 may either be digitally signed, and therefore in digital form from the outset, or it may be a manually signed document that is scanned, digitized, and sent as a graphic file from the requestor 104 to the data processing center 102 (e.g., by means of a fax machine).
The means of the services 200 for receiving the bundled request, or one or more of the individual components thereof, may include one or more fax machine, telephones, computers, hand-held telecommunications devices, or other communication receiving means. At present, a typical means for receiving the request is a computer, together with a telephone for optional receipt of a telephone call from the call center 100 . In order to streamline the process by which the data processing center 102 is able to communicate or transmit the request to the services 200 , a service interface module may be advantageously employed. The provider interface module allows service providers 200 to log in on a regular basis and determine if and what services have been requested through the data processing center 102 . This potentially eliminates the need for phone calls from the call center 114 .
The call center 114 may include one or more fax machines, computers, telephones, or other means for receiving the request from the data processing center 102 . The call center 100 typically employs a number of individuals who are assigned the task of providing secondary notification 102 to each service 200 to ensure compliance of the request 150 by the service providers 200 . The call center advantageously includes a computerized system for assigning each request to a particular individual caller, preferably one having a pre-established relationship with the service provider 200 to which the request 150 has been or will be sent. Of course, it is certainly within the scope of the invention to provide any system that assigns any caller to any particular provider as desired.
The data processing center 102 advantageously includes storage means, such as one or more magnetic disks or tapes, volatile and nonvolatile memory devices, optical storage devices, and the like for storing the encrypted copy of the secondary identification and personal identification, preferably in the form of a searchable digital database for later access and retrieval. In the case where the service provider 200 can communicate with the data processing center 102 by means of a provider interface module, the service provider 200 may be able to determine whether a requested service has already been copied and stored within the digital database. Moreover, the searchable digital database may be made accessible to the service provider 200 to allow the service provider 200 to quickly pull up a the personal identification and the secondary identification.
The data processing center 102 includes means for sending a secure copy 152 of the secondary identification to the requestor 104 and/or other authorized party such as identity theft protection service 106 , or such as one or more networked computers. The data processing center may also include means for sending a tangible copy 152 of the requested secondary identification to the requester 104 or other authorized party, such as one or more fax machines or a conventional mail carrier.
In order to provide the ability for a requester to periodically check the status of a particular request, a status check module may be provided by the data processing center 102 . The status check module may also allow a requester to determine if there is a problem or informality that might be causing delay in processing the request, such as the need to supply or obtain additional information.
As illustrated in FIG. 3 , a flow diagram depicting an exemplary process 210 for obtaining a secondary identification from the primary identification of a requester. In a first step, a requester generates a request for a secondary identification. The requester submits the requestor's name, email address, postal address and/or phone number to the data processing center 102 . The data processor then performs the sub-processes that will be described below to obtain a secondary postal address, a secondary email, a secondary phone number and/or any other service.
After obtaining a secondary postal address, a secondary email, secondary phone number and/or other secondary identification from the sub-processes, the data processing center will store the secondary identification information along with the requestor's primary identification information in a secure system. The data process center 102 then will send the secondary identification information to the requestor via secure connection.
As illustrated in FIG. 4 , a flow diagram depicting an exemplary sub-process 220 of obtaining a secondary postal address for a requester from a primary postal address obtained from the requester. In a first step, the data processing center obtains the primary postal address from the requester. The data processing center in the next step obtains a postal address from a mail service provider such as a public postal service or a private postal service. Examples of private postal services are United Parcel Service (UPS) or Mailbox Etc. In obtaining a secondary postal address for the requestor, the data processing center 102 performs an algorithm to determine an appropriate postal address convenient to the requester.
The data processing center 102 obtains a secondary postal address by obtaining a post office box at one of the above-mentioned postal centers. The requestor may determine the size of the post office box and may also request an option of automatic forwarding of mail from their secondary postal address to their primary postal address. Another option for the requester is to authorize the post office box provider to periodically empty the post office box. In addition, the requester may authorize the scanning of the mail which will be forwarded to the requestor's primary email address.
The next step in FIG. 4 , the data processing center 102 stores the secondary postal address of the requester along with primary postal address. The data processing center 102 then sends the secondary postal address information to the requester via a secure connection and/or process.
As illustrated in FIG. 5 , a flow diagram depicting an exemplary sub-process of obtaining a secondary email for a requestor. In the first step, a requestor requests a secondary email from the data processing center 102 . The data processing center 102 obtains a secondary email from an email database and server. The data processing center 102 associates the secondary email with the primary email. The secondary email address is sent to the requester via a secure connection and/or process.
As illustrated in FIG. 6 , a flow diagram depicting an exemplary sub-process 220 of obtaining a secondary phone number for a requester. In a first step, a requester requests a secondary phone number from the date processing center 102 . The data processing center then requests a phone number from a telephone service provider. The data processing center 102 then registers the secondary phone number. The requester can either request the creation of a voicemail system to retrieve messages or the automatic forwarding of voicemails to the requestor's computer via email. The voicemail messages will be sent in a wave format or similar format. The data processing center 102 then sends a secondary phone number to the requester via secure connection and/or process.
If the creation of a secondary identification is in use for purpose of obtaining a privacy credit card, the data processing center 102 will require a primary telephone number from the requester.
The above-mentioned services in FIGS. 4 , 5 , and 6 are performed simultaneously or individually depending on the services requested by the requestor. Further, the secondary identification which includes the secondary email, postal address, and phone number, may be sent to the requestor in one or more transactions via a secure connection and/or process.
FIG. 7 is an exemplary illustration of another embodiment of the invention in which the requestor is requesting a credit card with the information contained in the credit card is the requestor's secondary identification. In FIG. 7 , the requester sends a communication to the data processing center 102 to obtain a credit card with said secondary identification. The data processing center 102 sends communication to the credit card issuing bank to obtain approval for a credit card. Simultaneously or subsequently, the data processing center obtains a secondary postal address, email, and phone number as discussed previously. Upon approval of credit, the data processing center 102 transmits a copy of requestor's secondary identification along with the approval of credit via secure connection and/or process.
The data processing center swaps with the credit issuing bank the primary identification and secondary identification. Thus, the requestor's privacy credit card contains only the secondary identification and none of the requestor's primary identification. FIG. 8 illustrates the process in a detailed form.
As illustrated in FIG. 8 , a flow diagram depicting an exemplary process for obtaining a credit card containing the secondary identification of the requester. In the first step, the requester provides data required by the credit issuing bank to process the application for credit approval. The data required may be the requestor's social security number, birth date, address, email address, phone number, driver license number, or any other identifying information needed by the credit issuing bank, which includes one or more of the listed identifying information previously described. The requester transmits the above-mentioned data to the data processing center 102 .
The data processing center 102 receives the requestor's primary data via internet or other form of communication. The data processing center 102 transmits the primary data to the credit issuing bank. The credit issuing bank processes the application with the supplied primary data information provided by the requester. The credit issuing bank then either approves or rejects the credit application and transmits the approval or denial of said application to the data processing center 102 for further processing.
If the credit issuing bank rejects requestor's application for credit, the data processing center 102 transmits the notice of rejection to the requester and the transaction is terminated.
If the credit issuing bank approves the requestor's application for credit, the data processing center then processes the requestor's primary identification to obtain a secondary identification as discussed above. The data processing center 102 transmits the primary identification data, i.e. postal address, email, and phone number, to sub-process 200 . The primary identification and secondary identification are stored in association with one another.
The data processing center 102 , then swaps the requestor's primary identification with the requestor's secondary identification in the credit issuing bank's database. If the credit issuing bank's database is capable of storing both the primary and secondary identification of the requester, both identifications may be stored at the credit issuing bank's database. If the above scenario, the credit issuing bank will set the requestor's secondary identification as the primary identification on the credit card.
In another scenario, in which the credit issuing bank's database can not store both the primary and secondary identification, the data processing center 102 will swap the requestor's primary identification stored in the credit issuing bank's database with the requester secondary identification.
Upon completion of the transmission of the requestor's secondary identification to the credit issuing bank, the credit card is issued to the requestor. The data processing center 102 than transmits the secondary identification via secure connection and/or process.
The secondary identification created for those obtaining a privacy credit card have the same options and choices as previously detailed above in the secondary identification description. In addition, the privacy credit card also consists of a transaction privacy feature if elected by the requester. This feature allows the requester to obtain the billing statement of the credit card by electronic means in which the only information transmitted is the total bill with none of the billing statements transactions included. The requester may log into the credit card account, if the requestor so chooses, to obtain the transaction history for said billing period.
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The present invention relates to a method to the creation and management of a secondary identification to avoid identify theft. Identity theft may occur over the internet, the purchase of goods and services by credit, and many other forms not yet known. The present invention creates a secondary identification for a person by creating one or more of the following secondary identifications which include a secondary email address, a secondary postal address, a secondary phone number, and any other identifying secondary information. The present invention describes methods and systems to create a secondary identification. Further, the present invention may be used to create a credit card containing the requestor's secondary identification.
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SUMMARY OF THE INVENTION
This invention is concerned with novel N-substituted 2-oxo-3-benzothiazoline derivatives. It also relates to the use of these compounds in regulating the growth of leguminous plants. The invention further relates to the use of the novel 2-oxo-3-benzothiazoline derivatives in plant growth regulant compositions.
DETAILED DESCRIPTION OF THE INVENTION
The compounds employed in the present invention are 2-oxo-3-benzothiazoline derivatives of the formula ##STR3## wherein R is selected from the group consisting of ##STR4## potassium and sodium cations; n is an integer of from 1 to 2; and m is an integer of from 1 to 2.
When R is potassium or sodium cation, a salt is formed; the preferred salt is the one formed when potassium is the cation.
Compunds of the invention wherein R is potassium or sodium cation can be formed by mixing 3-(hydroxy-methyl)-2-benzothiazolinone or 3-(2-hydroxy-ethyl)-2-benzothiazolinone with carbon disulfide and a hydroxide, such as KOH or NaOH, and allowing the resulting mixture to react. When potassium hydroxide is used the reaction can be illustrated as follows: ##STR5##
Example 1 illustrates the above process in greater detail.
EXAMPLE 1
To a stirred charge containing 0.25 mol of 3-(2-hydroxyethyl)-2-benzothiazolinone in 500 ml of carbon disuflide, 16.5 g (0.25 mol) of potassium hydroxide was added in small portions at 20°-25° C. over a 10 minute period. After stirring at 25°-30° C. for 24 hours, 600 ml of ethyl ether was added, and stirring continued for 15 minutes. The product xanthic acid, O-[2-(2-oxo-3-benzothiazolinyl)-ethyl]ester, S-potassium salt, was collected by filtration and air-dried at 25°-30° C. The data is summarized below:
______________________________________Compound % % NNo. 1 Yield Calc'd Found______________________________________ ##STR6## 99 4.52 4.47______________________________________
s-potassium O-[2-(2-oxobenzothiazoline-3-yl) ethyl]-xanthic acid and S-potassium O-[(2-oxobenzothiazolin-3-yl)-methyl] xanthic acid can be used to prepare compounds of the invention wherein R is --(CH 2 ) m CN and ##STR7## and where m and n have the values previously assigned, according to the following general reactions: According to the above reactions, compounds of the invention were prepared as illustrated in Examples 2 and 3.
EXAMPLE 2
To a stirred slurry containing 31 g (0.1 mol) of S-potassium O-[2-(2-oxo-3-benzothiazolinyl)ethyl] xanthic acid in 400 ml of water 8.5 g (0.11 mol) of chloroacetonitrile was added in one portion. The reaction mixture was stirred at 25°-30° C. for two days. After the addition of 600 ml of ethyl ether, stirring was continued for 30 minutes. The impurities were removed by filtration. The separated ether layer of the filtrate was washed with water until neutral to litmus and dried over sodium sulfate. The ether was removed in vacuo at maximum temperature of 80°-90° C. at 1-2 mm. Carbonodithioic Acid, S-(Cyanomethyl)ester, O-[2-(2-oxo-3-benzothiazolinyl)ethyl] ester, a dark amber viscous liquid, was obtained in 35% yield.
__________________________________________________________________________Compound % % N % SNo. 2 Yield Calc'd Found Calc'd Found__________________________________________________________________________ ##STR8## 35 9.02 9.90 30.99 30.12__________________________________________________________________________
example 3
to a stirred solution containing 31 g (0.1 mol) of S-potassium O-[2-(2-oxo-3-benzothiazolinyl)ethyl] xanthic acid in 500 ml of water, a solution containing 12.6 g (0.055 mol) of ammonium persulfate in 100 ml of water was added dropwise at 0°-10° C. over a 20 minute period. After stirring at 0°-10° C. for 1.5 hours, the solid was collected by filtration, washed with water until neutral and air-dried at 25°-30° C., Formic acid, thiono-, bis-, 1,1'-dithio-, bis[2-(2-oxo-3-benzothiazolinyl)ethyl] ester, mp 151°-4° C. with decomposition, was obtained in 67% yield. After recrystallization from DMF, Compound 3 melted at 158°-160° C. with decomposition.
__________________________________________________________________________Compound % % N % SNo. 3 Yield Calc'd Found Calc'd Found__________________________________________________________________________ ##STR9## 67 5.18 5.24 35.58 35.44__________________________________________________________________________
as noted above, the compounds of the present invention have been found to be effective in the regulation of leguminous plant growth; the preferred legume is soybean (Glycine max).
The terms "plant growth regulant effect", "plant growth regulation" or words to that effect, are used in this specification and in the claims to mean the causation by the chemicals of the present invention, of a variety of plant responses which achieve a promotion, inhibition or modification of any plant physiological or morphological process. It should additionally be recognized that various plant responses may also result from a combination or sequence of both physiological and morphological factors. Such plant responses are most readily observed as changes in size, shape, color or texture of the treated plant or any of its parts. The above changes may be characterized as an acceleration or retardation of plant growth, stature reduction, leaf or canopy alternation, increased branching, increased fruit set, accelerated fruit set and the like. While many of these modifications are desirable in and of themselves, most often it is their effect on the economic result that is of most importance. For example, a reduction in stature of the plant permits the growing of more plants per unit area.
It is to be understood that the regulation of desirable leguminous crop plants in accordance with the instant invention does not include the total inhibition or the killing of such plants. Although phytotoxic amounts of the materials disclosed herein might be employed to exert a herbicidal (killing) action, it is contemplated here to employ only plant regulating amounts of such materials in order to modify the normal sequential development of the treated plant to agricultural maturity. The application of a plant regulating amount may be applied to plants in sequence at various stages of the plants' development to obtain various desirable responses. As may be expected, and as is apparent to those skilled in the art, such plant regulating amounts will vary, not only with the material selected, but also with the modifying effect desired, the species of plant and its stage of development, the plant growth medium and whether a permanent or transitory effect is sought.
In accordance with this invention, it has been found that desirable modification of leguminous crop plants is achieved by applying the above-described plant regulants to the "plant" or plant "habitat". The term "plant" is understood herein to include the seeds, emerging seedlings, roots, stems, leaves, flowers, fruits or other plant parts. The term "habitat" is understood herein to mean the environment of the plant such as the plant growing medium, e.g., the soil.
In accordance with the practice of the invention, several plant growth regulating compositions were formulated by mixing various N-substituted 2-oxo-3-benzothiazoline compounds as the active ingredient, with acetone containing TWEEN 20 surfactant. The compositions thus formulated exhibited plant regulatory properties as illustrated by the test set forth in Example 4.
EXAMPLE 4
A number of soybean plants, variety Corsoy, are grown from seeds in aluminum pans in the greenhouse for a period of approximately one week to the primary leaf stage. The plants are thinned to three uniform plants in each pan and the height of each plant in the pan is measured to the terminal bud and the average height is noted. One pan containing three soybean plants is used for each chemical treatment and three pans are not treated and used as a control. The composition of active ingredient, acetone and TWEEN 20 surfactant was applied to the pan of growing plants by overhead spray at a rate equivalent to the desired rate of active ingredient per acre. The treated pans, along with the control pans, are maintained in a greenhouse and watered from below on a sand bench and fertilized with a uniform portion of a water-soluble balanced fertilizer.
Two weeks after application of the chemical, the average height of the soybean plants in the treated pan is again measured as above and the difference in the average height before and two weeks after application represent the increase in the development of the treated pans. This development in growth of the treated plants is compared to the average increase in growth of the plants in the control pans during the same period of time. A variation of 25% or more in the development of at least two-thirds of the treated plants when compared to the development of the control plants demonstrates that the chemical is an effective plant regulant. Thus, a chemical is considered active when the treated plants manifest a decrease in growth of at least 25% less than that of the control plants, i.e., stature reduction, or an increase in growth in excess of 25% of that of the control plants, i.e., growth stimulation.
Table III below summarizes the results and observations made in accordance with Example 4 when the N-substituted 2-oxo-3-benzothiazolines of the invention were utilized as the active ingredient at several rates. Some slight phytotoxicity was noted, especially at the higher application rates.
Table III______________________________________Compounds RATEof Lbs/AcreExample (Kilos/hectare) Response______________________________________1 6.0 (6.72) Stature reduction, leaf distor- tion, thick leaf texture, inhi- bition of apical development, slight leaf burn. 6.0 (6.72) Leaf distortion, altered canopy, thick leaf texture. 3.0 (3.36) Leaf distortion. 1.2 (1.34) No response noted.3 6.0 (6.72) Stature reduction, axillary bud development, leaf distortion, thick leaf texture, inhibition of apical development, slight leaf burn. 3.0 (3.36) Leaf distortion, inhibition of apical development, slight leaf burn.______________________________________
Further plant growth regulating activity was demonstrated when the novel N-substituted 2-oxo-3-benzothiazolines of the present invention were tested according to the procedure described in Example 5.
EXAMPLE 5
A number of soybean plants, variety Williams, are grown from seeds in plastic pots in the greenhouse for a period of one week at which time the plants are thinned to one plant per pot. When the second trifoliate leaf (three weeks) was fully expanded, the plants were treated with a solution of the active ingredient in acetone and water. Aqueous Tween 20 is used as a surfactant.
When the fifth trifoliate leaf (four to five weeks) was fully expanded, the treated plants were compared with the non-treated control plants and the observations recorded.
Table V below summarizes the results and observations made in accordance with the above procedure.
TABLE IV______________________________________Compounds RATEof Lbs/AcreExample (Kilos/hectare) Response______________________________________1 2.5 (2.80) Stature reduction, stem distor- tion, leaf alteration, altered canopy, decreased dry matter accumulation. 0.5 (0.56) Decreased dry matter accumulation. 0.1 (0.11) Decreased dry matter accumulation.2 *2.5 (2.80) Leaf distortion, altered canopy, leaf alteration, leaf inhibition, slight leaf burn, decreased dry matter accumulation. *0.5 (0.58) Leaf alteration, decreased dry matter accumulation. *0.1 (0.11) Decreased dry matter accumulation.3 2.5 (2.80) Leaf alteration, slight leaf burn, decreased dry matter accumulation. 0.5 (0.56) Leaf alteration, decreased dry matter accumulation. 0.1 (0.11) Decreased dry matter accumulation.______________________________________ *Data combined from two tests.?
Compound 1 was further tested according to the procedure described in Example 6.
EXAMPLE 6
Individual soybean plants, variety Corsoy, are grown from seed in 6-inch pots containing a good grade of top soil. Two pots of 4 week old plants (3-4 trifoliate stage) and two pots of 6-week old plants (5-6 trifoliate stage) are used for each application of the chemical. An overhead spray of an aqueous composition of the chemical is applied to the pots at an equivalent rate as indicated below. Two to four sets of plants which received no chemical application are included and serve as controls. All of the pots are maintained under good growing conditions and are watered and fertilized with a uniform amount of a water-soluble balanced fertilizer. Two weeks after the application of the chemical, the growth responses of the treated plants are compared with that of the control plants. The total height of the plant is measured to the tip of the terminal bud. A variation of 15 percent in the average total height of the treated plants, when compared to the average total height of the control plants, demonstrates that the chemical is an effective plant growth regulator. These observations are repeated at four weeks after chemical application as a further evaluation of plant regulatory activity. The observations made on 4-week and 6-weekold plants, at 2 and 4 weeks form a composite evaluation.
Observations made utilizing the test procedure of Example 6 are summarized in Table V.
TABLE V______________________________________Compound RATEof Lbs/AcreExample (Kilos/hectare) observations______________________________________1 1.0 (1.12) Enhanced pod set. 2.5 (2.80) Early pod set, enhanced pod set, leaf distortion. 5.0 (5.60) Early pod set, enhanced pod set, leaf distortion, leaf inhibition, axillary bud inhibition.______________________________________
In selecting the appropriate time and rate of application of the active ingredient, it will be recognized that precise rates will also be dependent upon the desired response, mode of application, plant variety, soil conditions and various other factors known to those skilled in the art. While a rate of up to 11.2 kilos per hectare may be used, rates below 6.72 kilos per hectare are preferred. In addition, it will be recognized that single or multiple applications may be used to exert the desired response.
In the practice of the invention, the active ingredient can be used alone or in combination with materials referred to in the art as adjuvants, in either liquid or solid form. To prepare such compositions, the active ingredient is admixed with an adjuvant including diluents, extenders, carriers and conditioning agents to provide compositions in the form of finely-divided particulate solids, granules, pellets, wettable powders, dusts, solutions and aqueous dispersions or emulsions. Thus, the active ingredient can be used with an adjuvant such as a finely-divided particulate solid, a solvent liquid or organic origin, water, a wetting agent, dispersing agent or emulsifying agent or any suitable combination of these.
Illustrative finely-divided solid carries and extenders which are useful in plant growth regulating compositions of this invention include the talcs, clays, pumice, silica, diatomaceous earth, quartz, Fullers, earth, sulfur, powdered cork, powdered wood, walnut flour, chalk, tobacco dust, charcoal and the like. Typical liquid diluents include Stoddard solvent, acetone, alcohols, glycols, ethyl acetate, benzene and the like. The plant growth regulating compositions of this invention, particularly liquids and wettable powders, usually contain one or more surface-active agents in amounts sufficient to render a given composition readily dispersible in water or in oil. The term "surface-active agent" is understood to include wetting agents, dispersing agents, suspending agents and emulsifying agents. Such surface-active agents are well known and reference is made to U.S. Pat. No. 2,547,724, columns 3 and 4, for detailed examples of the same.
Generally, the active ingredients are applied in the form of a composition containing one or more adjuvants which aid in the uniform distribution of the active ingredient. The application of liquid and particulate solid compositions of the active ingredient can be carried out by conventional techniques utilizing, for example, spreaders, power dusters, boom and band sprayers and spray dusters. The composition can also be applied from airplanes as a dust or spray.
Compositions of this invention generally contain from about 5 to 95 parts active ingredient, about 1 to 50 parts surface-active agent and about 4 to 94 parts solvents, all parts being by weight based on the total weight of the composition.
Although this invention has been described with respect to specific modifications, the details thereof are not to be construed as limitations, for it will be apparent that various equivalents, changes and modifications may be resorted to without departing from the spirit and scope thereof and it is understood that such equivalent embodiments are intended to be included herein.
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The present invention relates to compounds of the formula ##STR1## wherein R represents ##STR2## and potassium and sodium cathions; n is an integer of from 1 to 2; and m is an integer of from 1 to 2. The invention relates to the use of said compounds in a method of regulating leguminous plant growth as well as to plant growth regulant compositions.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to reaction products of allantoin and formaldehyde and, more particularly, to such products which contain very low levels of free formaldehyde (<0.1%), while retaining advantageous, long-lasting anti-microbial properties, particularly against the organism B. cepacia.
[0003] 2. Description of the Prior Art
[0004] Berke, P. A., in U.S. Pat. No. 3,248,285 described a reaction product of allantoin and formaldehyde (Germall® 115) from the reactants in a mole ratio of 1:1.5, respectively; and in U.S. Pat. No. 4,271,176 and Reissue 32,848, (Germall® II) in a mole ratio of 1:4. However, during recent evaluations using modern C 13 NMR techniques, these reaction products were found to contain 0.5% to 1.0% of free formaldehyde. This amount was considered in the past to be necessary to retain its anti-microbial activity; although now it is recognized that a considerable amount of free formaldehyde in the product is disadvantageous from a safety (irritation) and environmental standpoints.
[0005] Accordingly, it is an object of this invention to prepare reaction products of allantoin and formaldehyde which have long-lasting anti-microbial properties with the presence therein of only very low levels of free formaldehyde (i.e. <0.1%).
[0006] Another object of the invention is to provide a method of making such effective reaction products.
[0007] Still another object of this invention is to provide a synergistic combination of such products with other known fungicides to obtain broad spectrum activity against bacteria and fungi, yeast, molds, and the like.
SUMMARY OF THE INVENTION
[0008] This invention relates to a reaction product of allantoin and formaldehyde,
made in a molar ratio of about 1:2.75-1:3.25, preferably 1:3, respectively, preferably under controlled pH (5.0 to 7.0) and temperature (40° to 60° C.) conditions, which contains substantially no free formaldehyde (<0.1%), with advantageous long-lasting, broad spectrum anti-microbial properties, particularly against the organism B. cepacia.
[0010] What has been discovered herein is that reaction products of allantoin and formaldehyde result in free formaldehyde being present in equilibrium with methylene diol and N-methylol. Unexpectedly, it was discovered that N-methylol and methylene diol, work in synergy to act as long-lasting anti-microbial agents, i.e. both can slowly react to provide anti-microbial protection against a wide range of microbes, including the difficult to kill B. cepacia , while free formaldehyde is present in very low concentrations (<0.1 %) in equilibrium with methylene diol.
[0011] Both equilibrium moieties can react with the amide moieties of allantoin to form several N-methylol of the allantoin compounds, which are stabilized by H-bonding; however they can slow hydrolyzed in water to give the methylene diol intermediate, which can react with amide to form N-methylols.
DETAILED DESCRIPTION OF THE INVENTION
[0012] The following examples describe preparation of Comparative Reaction Products (CRP) for (A) Germall® 115 (1:1.5); at low caustic levels; and (B) at high caustic levels; and (C) Germall® II (1:4), low caustic and (D) high caustic; and Invention Reaction Products (IRP) Germall® III (1:3), (A) laboratory and (B) commercial runs, with only enough caustic to neutralize the formic acid present in the Formalin solution.
Comparative Reaction Products
A. GERMALL® 115
1:1.5
[0013]
Allantoin
15.8 g (0.1 mole)
Formalin (37%)
12.2 g (0.15 mole)
Water
28.5 ml
[0014] The above mixture was refluxed for one hour to form a clear solution.
B. GERMALL® 115 (High Caustic)
1:1.5
[0015]
Allantoin
600 g (3.8 mole)
Formalin (37%)
450 g (5.5 mole)
Sodium Hydroxide
123 g
[0016] Refluxed for one hour to form a clear solution. Concentrated acetic acid was added to adjust the Ph to 4.0. Removed water to give a white powder.
C. GERMALL® II
1:4
[0017]
Allantoin
1053 g (6.66 mole)
Formalin (37%)
2160 g (26.64 mole)
[0018] The white suspension was heated to 85° C. and held for an additional hour; upon cooling a clear solution was obtained. Removed water under reduced pressure to give a white powder.
D. GERMALL® II
1 :4
[0019]
Allantoin
158.1 g (1.0 mole)
Formalin (37%)
324.2 g (3.99 mole)
Sodium Hydroxide 10%
32.0 g (0.08 mole)
[0020] Refluxed at 85° C. for one hour. The clear colorless solution obtained was dried under reduced pressure to give solid white powder residue.
Comparative Test Results
[heading-0021] Activity against yeast and mold:
[0022] 0.3% test solutions.
C. Albican A. Niger ATCC TEST SOLUTIONS ATTC1023 9642(for 3 Days) 0.3% Germall ® 115 (Exs. A/B) + + 0.3% Germall ® II(Exs. C/D) − − + Growth − No Growth
Invention Reaction Product
A. (Laboratory Scale) (GERMALL® III)
1:3
[0023]
Allantoin
1616 g (10.23 mole)
Formalin LM*(37%)
2488 g (30.68 mole)
Sodium Hydroxide 50%
24 g
*LM = low methanol (<0.5%) Borden Chemicals
[0024] Mixed and heated at 60° C. for 3 hours to give a clear solution. The Ph of the product was adjusted to 7.2 with the sodium hydroxide solution to neutralize formic acid in Formaline and the solution was spray dried to give a free-flowing, white powder.
Invention Reaction Product
B. (Commercial Scale) (GERMALL® III)
1:3
[0025]
Allantoin.wet cake
2095 lbs (10.23 mole)
Formalin LM (37%)
2488 lbs (30.68 mole)
Sodium Hydroxide 50%
23.6 lbs
Ph
6.5-7.0
Reaction Temp
40-60° C.
[0026] The resultant mixture then was further reacted at 85° C. for 3 hours to give a clear solution at pH 7.2. The solution was spray dried to remove water and other volatile by-products to give a free-flowing, white powder.
[0027] A study was conducted to determine the level of methylene diol in the reaction products versus the number of equivalents of formaldehyde added during formation. These results are based on quantitative 13C-NMR analysis and summarized in Table 1 below.
TABLE 1 Number of Equivalents Formaldehyde/Allantoin ppm Methylene Diol 4.00 3545 3.50 1916 3.25 1385 3.00 790 2.75 583 2.50 340 1.50 250
[0028]
TABLE 2
BIOACTIVITY OF GERMALL ® COMPOUNDS
INVENTION
EXS. PRESERVATIVE
ORGANISM
STATIC
CIDAL
IRP - Germall ® III (1:3)
Staph aureus
300 ppm
1250 ppm
E. coli
300 ppm
1250 ppm
P. aeruginosa
300 ppm
600 ppm
B. cepacia
150 ppm
300 ppm
C. albicans
>5000 ppm
—
A. niger
2500 ppm
2500 ppm
CRP - Germall ® II (1:4)
Staph aureus
300 ppm
1250 ppm
E. coli
600 ppm
1250 ppm
P. aeruginosa
600 ppm
1250 ppm
B. cepacia
150 ppm
600 ppm
C. albicans
5000 ppm
>5000 ppm
A. niger
2500 ppm
2500 ppm
CRP - Germall ® 115
Staph aureus
1250 ppm
2500 ppm
(1:1.5)
E. coli
1250 ppm
2500 ppm
P. aeruginosa
1250 ppm
2500 ppm
B. cepacia
600 ppm
1250 ppm
C. albicans
>5000 ppm
A. niger
5000 ppm
5000 ppm
Protocol
Minimum Inhibitory Concentration (MIC) Test Method
[heading-0029] Scope
[0030] The purpose of this test procedure is to screen experimental compounds for anti-microbial activity.
[heading-0031] Principle
[0032] The measurement of the lowest effective concentration of an anti-microbial or anti-microbial blend is important for recommending use concentrations. The MIC test is an in vitro tube dilution procedure used to identify effective concentrations of anti-microbials. In this test, the experimental compound is diluted by serial concentrations into nutrient culture media. Test organisms are then inoculated into the anti-microbial solutions.
[0033] If the experimental compound is effective, there is no growth observed in the test dilution tubes and they are clear. If the experimental compound is not effective, the test dilution tubes are cloudy, indicating growth. This test will determine static as well as cidal activity concentrations.
[heading-0034] Materials
[none]
1. Laminar flow hood (Baker Sterilgard SG 400)
2. 18×150 mm culture tubes
3. Stock antimicrobial solution
4. Media: Trypticase soy broth (BBL 11043) and AOAC Letheen broth (BBL 10914)
5. Test organisms: Staphylococcus aureus ATCC 6538 , Escherichia coli ATCC 8739 , Pseudomonas aeruginosa ATCC 9027 , Burkholderia cepacia ATCC 25416 , Candida albicans ATCC 10231, and Aspergillus niger ATCC 16404.
6. Spectrophotometer (Spectronic 20D, Milton Roy)
Minimum Inhibitory Concentration Test
[heading-0041] Procedure
[none]
1. Antimicrobial stock solutions are prepared at predetermined concentrations (i.e., 10% through 0.07%) depending on the test material. Serial doubling dilutions are made as follows. Each culture tube contains 5 mls of trypticase soy broth. Five mls of the stock solution are added to the first tube and vortexed. 5 mls are then removed and placed into the second tube, (and so on, until the last tube). At the final test concentration, 5 mls of the broth/antimicrobial mixture is decanted out.
2. The test organisms are prepared as with any organism inoculum (MLM 100-3, MLM 100-4, and MLM 100-5). A saline suspension of each organism is prepared. The bacterial organisms and the yeast are a standardized at a concentration of 1×10 6 cfu/ml. The mold inoculum is approximately 1×10 5 cfu/ml.
3. Inoculate each culture tube with 0.10 mls of organism inoculum and vortex.
4. Incubate bacterial tubes for 24 hours at 35° C. Incubate yeast or mold tubes for 48 hours at 25° C. Read for growth; turbid tubes for bacteria and yeast; mold clearly visible tubes. This is the minimum inhibitory concentration (static activity).
5. After the tubes are read, transfer all “clear” tubes and the first cloudy (growth) tube into Letheen broth containing neutralizers. Incubate the Letheen broth tubes for 48 hours at the bacterial or fungal incubation temperatures. Read for growth; turbid tubes for bacteria and yeast; mold clearly visible in mold tubes. This is the cidal activity concentration.
Discussion
[0048] The cidal activity of an anti-microbial can be rapidly screened by means of a MIC test before further evaluation tests, such as longer preservative efficacy tests, are performed. This test is a tube serial dilution procedure limited only by the water solubility of the material. Where anti-microbial materials are slightly insoluble, leaving the TSB broth turbid, a procedure modification can be made. Tubes are incubated for 24 hours (bacteria) or 48 hours (fungi) but instead of transfer to Letheen broth, the TSB tubes are streaked onto Letheen agar. The agar plates are then incubated appropriately and then read for absence or presence of growth. Depending on the degree of insolubility, a measure of cidal activity may be the only parameter measured.
[0049] Anti-microbial neutralization is important in this screening test. Letheen broth or agar contains neutralizers but if these do not neutralize the anti-microbial adequately, others can be added. These are to be determined prior to testing.
[0050] Aseptic technique is important in any microbiological procedure. All functional operations are performed under the laminar flow hood with use of sterile pipettes, tubes and media to eliminate cross-contamination. Surface sanitizers (i.e., alcohol) are used on the work surface before and after each operation. Ample time is allowed for recirculation of air within the sterile chamber of the hood.
[0051] The bioactivity data show particular effectiveness against the organism cepacia B . (cidal=300 ppm vs. 600 ppm and 1250 ppm for Germall® II and Germall® 115, respectively). However, if desired, even broader spectrum antibacterial activity can be achieved by combination products with the invention composition whose formulations are given below.
Invention Combination Products
Combination Blends (By Weight)
[0052]
(1)
Germall ® III
20-30%
MP - methyl paraben
8-12%
PP - propyl paraben
2-4%
PG - propylene glycol
q.s. 100
(2)
Germall ® III
40-45%
IPBC - iodopropynyl butyl carbamate
0.5-5%
PG - propylene glycol
qs 100
(3)
Germall ® III
98.5-99.5%
IPBC - iodopropynyl butyl carbamate
0.5-1.5%
(Powder)
Preservative Activity (Challenge Test)
[0053] A typical cosmetic emulsion was prepared for microbiological challenge testing and predetermined admixtures of a methylol compound and IPBC were added at various use levels. The emulsion thus prepared had the following composition:
Nonionic Emulsion (Unpreserved Control)
[0054]
Phase
Ingredient
% wt.
A
Water
69.80
A
Carbomer
10.00
B
Octyl Palmitate
5.00
B
Cetearyl alcohol and Ceteareth-20
2.00
B
Glyceryl Stearate and Laureth-23
2.50
B
Mineral Oil
5.00
C
Triethanolamine (99%)
0.20
D
Preservative
0.00
E
Hydrolyzed Collagen
0.50
E
Water
5.00
Total
100.00
Procedure:
Heat Phase A to 75° C. Heat Phase B to 75° C.
Add Phase B to Phase A. Mix until uniform.
Add Phase C. Remove heat.
Add Phase D at the appropriate temperature.
Add Phase E at 40° C.
Continue mixing to 30° C.
Standard Screening Emulsions
[0062]
% wt.
Phase A
Stearic Acid
5.00
Mineral Oil
2.50
Cetyl Alcohol
1.00
Lareth-5 and Ceteth-5 and
0.50
Oleth-5 and Steareth-5
Glycerol Monostearate and
1.50
Polyoxyethylene Stearate
Phase B
Deionized Water
88.0
Triethanolamine 99%
1.00
Citric Acid 30% aqueous solution
0.60
Preservative Admixture
qs
[0063] To prepare the emulsion, Phases A and B were heated separately to 75°-80° C. Phase A then was added to Phase B with mixing. The mixture then was cooled to 55°-60° C. At this point the desired amount of the preservative admixture was added and the product was cooled to 50° C. while stirring. The citric acid solution then was added to adjust the pH and the mixture was stirred until a temperature of 30° C. was reached.
[0064] The challenge tests were carried out using the following microorganisms: SA, ECOLI, PSA, PC, AN and CAN, in this manner. 50 g aliquots of the test emulsion containing various amounts of the preservative admixture were inoculated with approximately 10 7 -10 8 of the challenge organisms. The test samples then were stirred to disperse the challenge inoculum. The samples were incubated and assayed at 48 hours, 7, 14, 21 and 28 days. The assays were performed on 1 g of the test sample by serially diluting 10 1 to 10 6 of the original concentration. The plating medium for bacteria was Letheen agar and for fungi it was low pH Mycophil agar with Tween 20. Each plated sample was incubated for 48 hours at 37° C. for bacteria, 5 days at 25° C. for mold, and 3 days at 25° C. for fungi. After incubation, readings of the number of colonies per milliliter (cfu/ml) were made. At 21 days the test product was reinoculated with half of the original inoculum. The data is presented in Tables 3-11 below.
Challenge Tests
[0065]
TABLE 3
COMPARISON OF ACTIVITY OF GERMALL III TO GERMALL II AND 115
(SCREENING EMULSION)
Preservative
Conc.
Organism
48 hrs
7 days
14 days
21 days
28 days
Germall II
1000 ppm
SA
<10
<10
<10
<10
<10
EC
<10
<10
<10
<10
<10
PSA
<10
<10
<10
<10
<10
BC
<10
<10
<10
<10
<10
CAN
160,000
78,000
63,000
260,000
210,000
AN
<10
<10
<10
<10
<10
Germall III
1000 ppm
SA
<10
<10
<10
<10
<10
EC
<10
<10
<10
<10
<10
PSA
<10
<10
<10
<10
<10
BC
<10
<10
<10
<10
<10
CAN
160,000
380,000
380,000
810,000
640,000
AN
<10
<10
<10
<10
<10
Germall 115
2000 ppm
SA
3000
<10
<10
<10
<10
EC
490
<10
<10
<10
<10
PSA
<10
<10
<10
<10
<10
BC
<10
<10
<10
<10
<10
CAN
230,000
2,000,000
650,000
1,500,000
1,200,000
AN
<10
<10
<10
<10
<10
Germall II
2000 ppm
SA
<10
<10
<10
<10
<10
EC
<10
<10
<10
<10
<10
PSA
<10
<10
<10
<10
<10
BC
<10
<10
<10
<10
<10
CAN
150
9,600
48,900
490,000
210,000
AN
<10
<10
<10
<10
<10
Germall III
2000 ppm
SA
<10
<10
<10
<10
<10
EC
<10
<10
<10
<10
<10
PSA
<10
<10
<10
<10
<10
BC
<10
<10
<10
<10
<10
CAN
6000
195,000
460,000
690,000
1,070,000
AN
<10
<10
<10
<10
<10
Unpreserved
0
SA
2,100,000
57,000
90
<10
68,000
EC
37,000
96,000
96,000
43,000
790,000
PSA
70
4600
500
10,100
170,000
BC
2,100,000
860,000
1,520,000
3,520,000
>10E6
CAN
1,100,000
168,000
67,000
270,000
460,000
AN
700,000
56,000
44,000
190,000
320,000
[0066]
TABLE 4
COMPARISON OF ACTIVITY OF GERMALL III TO GERMALL II AND 115
(NONIONIC EMULSION)
Preservative
Conc.
Organism
48 hrs
7 days
14 days
21 days
28 days
Germall III
2000 ppm
SA
<10
<10
<10
<10
<10
EC
<10
<10
<10
<10
<10
PSA
<10
<10
<10
<10
<10
BC
<10
<10
<10
<10
<10
CAN
820,000
1,680,000
1,350,000
700,000
>1E6
AN
<10
<10
<10
<10
<10
Germall II
2000 ppm
SA
<10
<10
<10
<10
<10
EC
<10
<10
<10
<10
<10
PSA
<10
<10
<10
<10
<10
BC
<10
<10
<10
<10
<10
CAN
320,000
720,000
650,000
730,000
>1E6
AN
<10
<10
<10
<10
<10
Germall 115
2000 ppm
SA
1,500
<10
<10
<10
<10
EC
52,000
<10
<10
<10
<10
PSA
<10
<10
<10
<10
<10
BC
<10
<10
<10
<10
<10
CAN
>1E6
>1E6
>1E6
700,000
>1E6
AN
<10
20
390
370
>1E4
Germall III
4000 ppm
SA
<10
<10
<10
<10
<10
EC
<10
<10
<10
<10
<10
PSA
<10
<10
<10
<10
<10
BC
<10
<10
<10
<10
<10
CAN
24,000
>1E6
>1E6
730,000
>1E6
AN
<10
<10
<10
<10
<10
Germall II
4000 ppm
SA
<10
<10
<10
<10
<10
EC
<10
<10
<10
<10
<10
PSA
<10
<10
<10
<10
<10
BC
<10
<10
<10
<10
<10
CAN
50
10,000
620,000
460,000
>1E6
AN
<10
<10
<10
<10
<10
Germall 115
4000 ppm
SA
<10
<10
<10
<10
<10
EC
1,500
<10
<10
<10
<10
PSA
<10
<10
<10
<10
<10
BC
<10
<10
<10
<10
<10
CAN
1,060,000
1,000,000
>1E6
>1E6
>1E6
AN
<10
<10
<10
<10
<10
Unpreserved
0
SA
>1E6
6,300
>1E4
<10
>1E4
EC
>1E6
900,000
>1E4
>1E4
>1E4
PSA
20,000
>1E6
>1E4
>1E4
>1E4
BC
>1E6
>1E6
>1E4
>1E4
>1E4
CAN
>1E6
>1E6
>1E4
>1E4
>1E4
AN
500,000
510,000
>1E4
>1E4
>1E4
[0067]
TABLE 5
COMPARISON OF ACTIVITY OF GERMALL III TO GERMALL II AND 115
(SCREENING EMULSION)
Preservative
Conc.
Organism
48 hrs
7 days
14 days
21 days
28 days
Germall III
250 ppm
SA
69,000
<10
<10
<10
<10
EC
11,000
<10
<10
<10
<10
PSA
<10
<10
<10
<10
<10
BC
200
<10
<10
<10
<10
CAN
430,000
120,000
70,000
150,000
850,000
AN
100,000
200
70
40
1,300
Germall II
250 ppm
SA
55,000
<10
<10
<10
<10
EC
5500
<10
<10
<10
<10
PSA
<10
<10
<10
<10
<10
BC
<10
<10
<10
<10
<10
CAN
290,000
170,000
71,000
46,000
680,000
AN
50,000
<10
<10
<10
100
Germall 115
250 ppm
SA
117,000
30
<10
<10
1,500
EC
40,000
20
<10
<10
3600
PSA
<10
320
>1E4
>1E6
>1E6
BC
11,000
>1E6
>1E6
>1E6
>1E6
CAN
1,090,000
270,000
1,120,000
770,000
>1E6
AN
90,000
20,000
20,000
29,000
300,000
Germall III
500 ppm
SA
38,000
<10
<10
<10
<10
EC
18,000
<10
<10
<10
<10
PSA
<10
<10
<10
<10
<10
BC
<10
<10
<10
<10
<10
CAN
100,000
210,000
310,000
270,000
>1E6
AN
9000
<10
<10
<10
<10
Gemall II
500 ppm
SA
17,000
<10
<10
<10
<10
EC
610
<10
<10
<10
<10
PSA
<10
<10
<10
<10
<10
BC
<10
<10
<10
<10
<10
CAN
170,000
100,000
90,000
320,000
930,000
AN
40
<10
<10
<10
<10
Germall 115
500 ppm
SA
140,000
<10
<10
<10
<10
EC
24,000
<10
<10
<10
<10
PSA
<10
<10
<10
<10
<10
BC
<10
<10
<10
<10
<10
CAN
290,000
760,000
790,000
1,210,000
>1E6
AN
130,000
1,000
40
290
80,000
Unpreserved
0
SA
>1E6
34,000
6,800
20
>1E4
EC
18,000
4,900
>1E4
>1E4
>1E4
PSA
50
>1E4
>1E4
>1E4
>1E4
BC
>1E6
>1E6
>1E4
>1E4
>1E4
CAN
970,000
270,000
>1E4
>1E4
>1E4
AN
150,000
280,000
>1E4
>1E4
>1E4
[0068]
TABLE 6
COMPARISON OF ACTIVITY OF GERMALL PLUS AND GERMALL III/IPBC
(SCREENING EMULSION)
Preservative
Conc.
Organism
48 hrs
7 days
14 days
21 days
28 days
Germall Plus
SA
<10
<10
<10
<10
<10
Germall II
1980
EC
<10
<10
<10
<10
<10
IPBC
20
PSA
<10
<10
<10
<10
<10
BC
<10
<10
<10
<10
<10
CAN
<10
<10
<10
<10
<10
AN
<10
<10
<10
<10
<10
Germall III
1980
SA
<10
<10
<10
<10
<10
IPBC
20
EC
<10
<10
<10
<10
<10
PSA
<10
<10
<10
<10
<10
BC
<10
<10
<10
<10
<10
CAN
<10
<10
<10
<10
<10
AN
<10
<10
<10
<10
100
Germall III
1960
SA
<10
<10
<10
<10
<10
IPBC
40
EC
<10
<10
<10
<10
<10
PSA
<10
<10
<10
<10
<10
BC
<10
<10
<10
<10
<10
CAN
<10
<10
<10
<10
<10
AN
<10
<10
<10
<10
<10
Unpreserved
SA
580,000
3200
180
<10
>1E4
EC
5,200
70,000
>1E4
>1E4
>1E4
PSA
18,000
40,000
>1E4
>1E4
>1E4
BC
>1E6
>1E6
>1E4
>1E4
>1E4
CAN
>1E6
200,000
>1E4
>1E4
>1E4
AN
210,000
270,000
>1E4
>1E4
>1E4
[0069]
TABLE 7
COMPARISON OF ACTIVITY OF LIQUID GERMALL PLUS AND
GERMALL III/IPBC-LIQ (SCREENING EMULSION)
Preservative
Conc.
Organism
48 hrs
7 days
14 days
21 days
28 days
LiqGermPlus
SA
<10
<10
<10
<10
<10
Germall II
790
EC
<10
<10
<10
<10
<10
IPBC
10
PSA
<10
<10
<10
<10
<10
BC
<10
<10
<10
<10
<10
CAN
8,000
<10
<10
<10
<10
AN
<10
<10
<10
<10
<10
LiqGermPlus
SA
<10
<10
<10
<10
<10
Germall II
1580
EC
<10
<10
<10
<10
<10
IPBC
20
PSA
<10
<10
<10
<10
<10
BC
<10
<10
<10
<10
<10
CAN
<10
<10
<10
<10
<10
AN
<10
<10
<10
<10
100
Germall III
790
SA
<10
<10
<10
<10
<10
IPBC
10
EC
<10
<10
<10
<10
<10
Liquid
PSA
<10
<10
<10
<10
<10
BC
<10
<10
<10
<10
<10
CAN
26,000
<10
<10
<10
<10
AN
<10
<10
<10
<10
<10
Germall III
1580
SA
<10
<10
<10
<10
<10
IPBC
20
EC
<10
<10
<10
<10
<10
Liquid
PSA
<10
<10
<10
<10
<10
BC
<10
<10
<10
<10
<10
CAN
<10
<10
<10
<10
<10
AN
<10
<10
<10
<10
<10
Unpreserved
0
SA
580,000
3200
180
<10
>1E4
EC
5200
70,000
>1E4
>1E4
>1E4
PSA
18,000
40,000
>1E4
>1E4
>1E4
BC
>1E6
>1E6
>1E4
>1E4
>1E4
CAN
>1E6
200,000
>1E4
>1E4
>1E4
AN
210,000
270,000
>1E4
>1E4
>1E4
[0070]
TABLE 8
COMPARISON OF ACTIVITY OF GERMALL PLUS AND GERMALL III/IPBC
(SCREENING EMULSION)
Preservative
Conc.
Organism
48 hrs
7 days
14 days
21 days
28 days
Germall Plus
SA
42,000
<10
<10
<10
<10
Germall II
495
EC
40
<10
<10
<10
<10
IPBC
5
PSA
<10
<10
<10
<10
<10
BC
<10
<10
<10
<10
<10
CAN
48,000
<10
<10
<10
<10
AN
100
<10
<10
<10
<10
Germall Plus
SA
300
<10
<10
<10
<10
Germall II
990
EC
<10
<10
<10
<10
<10
IPBC
10
PSA
<10
<10
<10
<10
<10
BC
<10
<10
<10
<10
<10
CAN
<10
<10
<10
<10
<10
AN
<10
<10
<10
<10
<10
Germall III
495
SA
46,000
<10
<10
<10
<10
IPBC
5
EC
25,000
<10
<10
<10
<10
PSA
<10
<10
<10
<10
<10
BC
<10
<10
<10
<10
<10
CAN
11,000
<10
<10
<10
<10
AN
<10
<10
<10
<10
<10
Germall III
990
SA
24,000
<10
<10
<10
<10
IPBC
10
EC
1,000
<10
<10
<10
<10
PSA
19,000
<10
<10
<10
<10
BC
>1E6
<10
<10
<10
<10
CAN
2,500
<10
<10
<10
<10
AN
<10
<10
<10
<10
<10
Germall III
490
SA
23,000
<10
<10
<10
<10
IPBC
10
EC
900
<10
<10
<10
<10
PSA
18,000
<10
<10
<10
<10
BC
>1E6
<10
<10
<10
<10
CAN
2800
<10
<10
<10
<10
AN
<10
<10
<10
<10
<10
Germall III
980
SA
2,700
<10
<10
<10
<10
IPBC
20
EC
<10
<10
<10
<10
<10
PSA
<10
<10
<10
<10
<10
BC
<10
<10
<10
<10
<10
CAN
<10
<10
<10
<10
<10
AN
<10
<10
<10
<10
<10
Unpreserved
0
SA
>1E6
54,000
4,400
20
>1E4
EC
80,000
67,000
>1E4
>1E4
>1E4
PSA
2,000
4200
>1E4
>1E4
>1E4
BC
>1E6
>1E6
>1E4
>1E4
>1E4
CAN
990,000
320,000
>1E4
>1E4
>1E4
AN
380,000
170,000
>1E4
>1E4
>1E4
[0071]
TABLE 9
COMPARISON OF ACTIVITY OF LIQUID GERMALL PLUS AND
GERMALL III/0.5% OR 0.8% IPBC (SCREENING EMULSION)
Preservative
Conc.
Organism
48 hrs
7 days
14 days
21 days
28 days
LiqGermPlus
SA
110,000
<10
<10
<10
<10
Germall II
195
EC
2,600
<10
<10
<10
<10
IPBC
2.5
PSA
<10
<10
<10
<10
<10
BC
<10
<10
<10
<10
<10
CAN
240,000
120
<10
<10
>1E4
AN
230
<10
<10
<10
<10
LiqGermPlus
SA
2,800
<10
<10
<10
<10
Germall II
390
EC
1100
<10
<10
<10
<10
IPBC
5
PSA
<10
<10
<10
<10
<10
BC
<10
<10
<10
<10
<10
CAN
11,000
<10
<10
<10
20
AN
<10
<10
<10
<10
100
Germall III
195
SA
260,000
<10
<10
<10
<10
IPBC
2.5
EC
4,300
<10
<10
<10
<10
Liquid
PSA
<10
<10
<10
<10
<10
BC
<10
<10
<10
<10
<10
CAN
150,000
<10
<10
<10
>1E4
AN
200
<10
<10
<10
<10
Germall III
390
SA
170,000
<10
<10
<10
<10
IPBC
5
EC
2,500
<10
<10
<10
<10
Liquid
PSA
<10
<10
<10
<10
<10
BC
<10
<10
<10
<10
<10
CAN
50,000
<10
<10
<10
>1E4
AN
<10
<10
<10
<10
<10
Germall III
195
SA
70,000
<10
<10
<10
<10
IPBC
4
EC
1400
<10
<10
<10
<10
Liquid
PSA
<10
<10
<10
<10
<10
BC
<10
<10
<10
<10
<10
CAN
41,000
<10
<10
<10
40
AN
<10
<10
<10
<10
<10
Germall III
390
SA
76,000
<10
<10
<10
<10
IPBC
8
EC
3,400
<10
<10
<10
<10
Liquid
PSA
<10
<10
<10
<10
<10
BC
<10
<10
<10
<10
<10
CAN
14,000
<10
<10
<10
<10
AN
<10
<10
<10
<10
<10
Unpreserved
0
SA
>1E6
54,000
4,400
20
>1E4
EC
80,000
67,000
>1E4
>1E4
>1E4
PSA
2,000
4200
>1E4
>1E4
>1E4
BC
>1E6
>1E6
>1E4
>1E4
>1E4
CAN
990,000
320,000
>1E4
>1E4
>1E4
AN
380,000
170,000
>1E4
>1E4
>1E4
[0072]
TABLE 10
COMPARISON OF ACTIVITY OF GERMABEN II AND GERMABEN III
(SCREENING EMULSION)
Preservative
Use Level
Organism
8 hrs
7 days
14 days
21 days
28 days
Germaben II
0.30%
SA
480
<10
<10
<10
<10
EC
<10
<10
<10
<10
<10
PSA
<10
<10
<10
<10
<10
BC
<10
<10
<10
<10
<10
CAN
20,000
100
2,600
380,000
380,000
AN
<10
<10
<10
<10
<10
Germaben II
0.75%
SA
<10
<10
<10
<10
<10
EC
<10
<10
<10
<10
<10
PSA
<10
<10
<10
<10
<10
BC
<10
<10
<10
<10
<10
CAN
<10
<10
<10
<10
<10
AN
<10
<10
<10
<10
100
Germaben III
0.30%
SA
7,000
<10
<10
<10
<10
EC
<10
<10
<10
<10
<10
PSA
<10
<10
<10
<10
<10
BC
<10
<10
<10
<10
<10
CAN
14,000
120
>1E4
470,000
190,000
AN
<10
<10
<10
<10
<10
Germaben III
0.75%
SA
<10
<10
<10
<10
<10
5
EC
<10
<10
<10
<10
<10
PSA
<10
<10
<10
<10
<10
BC
<10
<10
<10
<10
<10
CAN
<10
<10
<10
<10
<10
AN
<10
<10
<10
<10
<10
Unpreserved
0
SA
>1E6
46,000
>1E4
60
>1E4
EC
>1E6
170,000
>1E4
>1E4
>1E4
PSA
690
24000
>1E4
>1E4
>1E4
BC
>1E6
>1E6
>1E4
>1E4
>1E4
CAN
440,000
>1E4
>1E4
>1E4
>1E4
AN
87,000
>1E4
>1E4
>1E4
>1E4
[0073]
TABLE 11
COMPARISON OF ACTIVITY OF GERMABEN IIE AND GERMABEN IIIE
(SCREENING EMULSION)
Preservative
Use Level
Organism
48 hrs
7 days
14 days
21 days
28 days
Germaben IIE
0.30%
SA
580
<10
<10
<10
<10
EC
<10
<10
<10
<10
<10
PSA
<10
<10
<10
<10
<10
BC
<10
<10
<10
<10
<10
CAN
1,600
<10
<10
<10
<10
AN
<10
<10
<10
<10
<10
Germaben IIE
0.75%
SA
<10
<10
<10
<10
<10
EC
<10
<10
<10
<10
<10
PSA
<10
<10
<10
<10
<10
BC
<10
<10
<10
<10
<10
CAN
<10
<10
<10
<10
<10
AN
<10
<10
<10
<10
<10
Germaben IIIE
0.30%
SA
270
<10
<10
<10
<10
EC
<10
<10
<10
<10
<10
PSA
<10
<10
<10
<10
<10
BC
<10
<10
<10
<10
<10
CAN
4,000
<10
<10
<10
90
AN
<10
<10
<10
<10
<10
Germaben IIIE
0.75%
SA
<10
<10
<10
<10
<10
EC
<10
<10
<10
<10
<10
PSA
<10
<10
<10
<10
<10
BC
<10
<10
<10
<10
<10
CAN
<10
<10
<10
<10
<10
AN
<10
<10
<10
<10
<10
Discussion of Challenge Testing Results
[0074] The 28 day challenge results reported in Tables 3-11 above demonstrate the effectiveness of the preservative composition of the invention in a use emulsion composition against a wide range of bacteria and fungi organisms.
[0075] While the invention has been described with particular reference to certain embodiments thereof, it will be understood that changes and modifications may be made which are within the skill of the art. Accordingly, it is intended to be bound only by the following claims, in which:
|
This invention relates to a reaction product of allantoin and formaldehyde made in a molar ratio of about 1:2.75-1:3.25, preferably 1:3, respectively, preferably under controlled pH (5.0 to 7.0) and temperature (40° to 85° C., preferably 50-60° C.) conditions, which product contains free formaldehyde (<0.1%), and methylene diol of about 580-1385 ppm, preferably at a pH of 7.2, with advantageous long-lasting, anti-microbial properties, particularly against the organism B. cepacia , and in combination products with parabens and iodopropynyl butyl carbamate (IPBC).
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is the U.S. national phase of PCT/EP2014/068498 filed Sep. 1, 2014, which claims priority of European Patent Application 13182780.0 filed Sep. 3, 2013.
FIELD OF THE INVENTION
[0002] The invention refers to a process and assembly for determining the radius, and diameter respectively, of a soil element which can be produced, more particularly by jet grouting.
BACKGROUND OF THE INVENTION
[0003] To consolidate the ground, for example by underpinning, or for sealing the ground, for example underneath dams or excavation pits, use is made of injection technology which is also known as jet grouting. Jet grouting is a soil grouting method wherein an energy-rich cutting jet consisting of water and a cement suspension is used to cut and erode the soil contained in the region of the borehole. The cutting jet which can also be surrounded by air is injected into the soil at high exit speeds. The eroded soil is repositioned and mixed with cement suspension. Part of the mixture is flushed through the annular space of the borehole towards the mouth of the borehole. This method can be used to produce construction elements of very different geometric shapes. Depending on the type of soil, the process applied and the liquid used, the width of erosion of the jet in the ground can be anything up to 2.5 metres.
[0004] The jet grouting process is used in special foundation engineering. Because of the nature of the process, the process of producing consolidated ground columns does not allow any visual monitoring. As a result, any non-uniformities in the soil structure or changes in the process parameters in the course of production can lead to a lesser quality of the ground column produced. This is the reason why, as a rule, trial columns are produced and analyzed prior to the start of the actual jet grouting work. There are different prior art methods of determining the diameter of a ground column produced by jet grouting, for instance thermal diameter measurements or hydrophone recordings.
[0005] From DE 195 21 639 A1 a method of monitoring a high-pressure injection process is known. A high-pressure injection rod with an exit nozzle for a high-pressure jet is driven into the soil. By lifting and simultaneously rotating the rod, the soil is cut open by the high-pressure jet and mixed with injection material. During the jetting operation, the soil vibrations in the vicinity of the high-pressure injection rod are recorded by a hydrophone. For this purpose, a gauge is driven into the soil in the surroundings of the high-pressure injection rod at a distance which corresponds to the expected range of the high-pressure jet. Said gauge is a pipe which is closed at its lower end, which is filled with water forming an incompressible medium and in which the hydrophone is guided. During the jetting operation, the hydrophone is guided at the level of the exit nozzle so that it is reached by the high-pressure jet exiting radially relative to the high-pressure injection rod. The resulting soil vibrations are converted to an analogue signal. In this way, it is possible to obtain information on the range of the high-pressure jet, which information is used to specifically vary the parameters of the jetting process.
[0006] From AT 505 438 A1 a method of determining the radial expansion and the content of hydraulically bonding materials of members produced by jet grouting (DSV members) is known. For this purpose, a first temperature curve is measured in a predeterminable period of time in a first range of the DSV-body; said temperature curve is then compared with reference curves. These measured temperature curves then allow to draw conclusions regarding the measurements and strength of the DSV column produced.
[0007] Thermal temperature determining methods require long preparatory periods of time, and there exists a further disadvantage in that an immediate evaluation cannot take place. The method of determining a diameter by means of a geophone can only be used down to a certain depth which, depending on the type of soil, amounts to approximately 8 to 15 metres. Furthermore, the rod and microphone have to be lifted synchronously, which requires additional technical facilities and which also leads to measuring inaccuracies if the two pieces of equipment are lifted at different speeds.
SUMMARY OF THE INVENTION
[0008] It is an object of the present invention to propose an improved process of determining the radius or diameter of ground columns produced, more particularly by jet grouting, which can be carried out quickly and can also be used down to great depths. Furthermore, it is an object of the invention to propose a suitable assembly for determining the radius or diameter of ground columns.
[0009] The objective is achieved by providing a process for determining the radius of a ground member produced by jet grouting, comprising the following process stages:
[0000] introducing at least one level rod into the ground; lowering a jet grouting tool, wherein a defined distance between the level rod and the jet grouting tool, more particularly, is smaller than the maximum range of the jet; lifting the jet grouting tool while carrying out rotational or pivoting movements, while the jet is activated, wherein, while the jet passes the level rod, vibrations are generated at the level rod; and recording a signal which represents the vibrations at the at least one level rod by means of a sensor which, more particularly is fixed to the level rod.
[0010] An advantage is that the process can be carried out at the same time as the ground member is produced. Already during or immediately after the ground member has been produced it is possible to evaluate the measured results which allow conclusions regarding the radius and/or diameter of the body. Overall, the process can be carried out quickly and in a simple way. A further advantage is that said process is also suitable for obtaining reliable measurements at greater depths in excess of 10 metres. The process of recording vibrations takes place while the jet grouting tool injects injection material into the soil. In the context of the present disclosure, a maximum range of the jet, more particularly, is meant to refer to a range up to which the injection material penetrates the soil and at which vibrations can be measured at the level rod.
[0011] The jet grouting tool is suitable for producing full columnar, half-columnar or lamellae-like ground elements which can also be referred to as ground improving members or ground columns. The shape of the ground elements can be achieved by suitably controlling the jet grouting tool. For producing a column, respectively of a substantially circular-cylindrical member, the jet grouting tool is continuously rotated around its axis of rotation. Accordingly, half-columnar members can be produced by pivoting the jet grouting tool to and fro around the axis of rotation while the tool is being lowered, respectively lifted. Lamellae can be produced by introducing suspension by the jet grouting tool partially at different depths. The vibrations generated at the level rod permit conclusions regarding the depth of penetration of the injection material in this circumferential region in which the level rod is arranged relative to the axis of rotation of the jet grouting tool. The information on the radius in said circumferential region can be used to calculate the diameter of the column, if necessary. When producing a half-column or a lamella, there is no need to determine the diameter because said members extend only over part of the circumferential region around the axis of rotation.
[0012] Independently of the shape of the ground member to be produced, said process is suitable for reliably determining whether the jet, respectively the suspension, has reached the required radial range starting from the jet grouting tool. When rotating or pivoting the jet grouting tool around its own axis, the jet passes the level rod once per rotation or once per pivoting movement. If the jet is strong enough, the jet, when passing, hits the level rod, which generates vibrations. Such vibrations can be recorded by suitable sensors and evaluated by an evaluation unit, thus allowing conclusions regarding the radial depth of penetration of the jet in the ground. If the jet does not comprise the required strength ensuring that the depth of penetrations reaches the level rod, either the vibrations are less pronounced or there are no vibrations, which means that the radius of the ground column is smaller than the distance between the drilling axis and the level rod.
[0013] The process sequence is preferably such that first the at least one level rod is introduced into the ground and subsequently, the jet grouting tool is lowered at a defined distance from the at least one level rod up to the depth required for the production of the ground column. However, in principle, the reversed sequence is also conceivable, i.e. first the jet grouting rod is lowered and then one or several level rods is/are introduced at a defined distance from the jet grouting tool. After the jet grouting tool has been lowered down to the final depth, the jet is activated and the tool is lifted while being rotated or pivoted. While the tool is being rotated and lifted, an injection material is ejected out of one or several nozzles under high pressure and high speeds. Said injection material erodes the surrounding soil. Simultaneously with the erosion of the soil, a cement suspension is introduced under pressure, and as a result of the process-related turbulences, it is mixed in situ in the immediate production region. In a modified version of the process, it is also possible that the jet is activated during the lowering operation. In this case, the at least one level rod has to be introduced into the ground first. The operating pressure of the jet medium is preferably in excess of 200 bar. The exit speed of the jet medium can be in excess of 100 m/s. Depending on the type of soil, the type of process and the liquid used, the erosion width of the jet in the building ground can amount to anything up to 2.5 meters from the borehole.
[0014] The injection material can be adjusted to the subsoil conditions and to the required operating result, respectively selected accordingly. The injection material can be liquids, water, suspensions, cement loam and for chemical means in the form of solutions and/or emulsions. To consolidate the subsoil, for instance in the case of underpinning or sealing work, a suspension of water and bonding agents is used in particular. The bonding agent can be, more particularly, mortar, cement, ultra fine cement, silicate gel or even plastic solutions. To increase the erosion factor and thus the range, the jet can additionally be surrounded by compressed air via an annular nozzle. The hardening of the bonding agent results in the formation of a half-columnar, columnar or lamellae-like ground improvement member.
[0015] According to a preferred embodiment, two level rods are introduced into the soil, wherein both rods are circumferentially offset relative to the jet grouting tool, more particularly so as to be arranged on opposed sides. By using two level rods it is possible to reliably determine whether the jet and, respectively, the ground column to be produced, comprises the required radial extension or diameter around the circumference of the drilling tool. If two level rods are used, these are preferably arranged diametrically opposed relative to the borehole, i.e. they are offset relative to one another by substantially 180°, with this value comprising certain angular deviations of up to ±10°. Needless to say it is also conceivable to use three or more rods which preferably should be uniformly circumferentially distributed around the borehole to be produced.
[0016] The at least one level rod is arranged at a distance from the axis of the jet grouting tool, i.e. of the borehole to be produced, which distance preferably amounts to at least 0.75 meters and/or a maximum of 1.25 metres. If several level rods are used, it is proposed according to an advantageous embodiment that at least two of the level rods comprise different distances from the borehole to be produced. By selecting different distances for the first level rod and the second level rod respectively from the borehole, the diameter of the ground column to be produced can be reliably determined and controlled, respectively. Thus, a first distance of a first level indicting rod can be selected to be identical to or slightly larger than the required radius of the ground column; the second level rod can be set to a second distance which is greater than the first distance. If then the drilling tool is rotated while the jet is activated, with vibrations being determined at the first level rod, whereas no vibrations or only slight vibrations occur at the second level rod, it can be concluded that the radius of the ground column is located in the annular region between the first and the second level rod. More particularly, the two level rods can be arranged relative to the borehole in such a way that the difference between the first distance (of the first level indicting rod relative to the drilling axis) and the second distance (of the second level rod relative to the drilling axis) amounts to at minimum of 5 to 10 cm and/or a maximum of 15 to 20 cm.
[0017] The sensor used for recording vibrations is preferably arranged at the upper end of the respective level rod, which, more particularly projects from the ground. In the context of the present disclosure, “upper end”, more particularly refers to the rod portion which is positioned above the ground edge and can therefore easily be reached for the purpose of fixing the associated sensor to it. During the vibration recording process, the sensor remains in a fixed position at the level rod. The respective sensor is connected to the associated level rod in such a way that any vibrations or structure-borne sound of the level rod are transmitted directly to the sensor, i.e. without any intermediate medium such as water. For instance, the sensor can be clamped or bolted to the rod or form-fittingly connected thereto, or in any other way releasably fastened thereto, so that the jetting-related vibrations can easily be transmitted from the level rod to the sensor. The sensors are connected to an electronic unit which is able to further process and store the vibration signals. According to an advantageous embodiment, the sensor used is a vibration sensor, more particularly a piezo sensor, with other vibration sensors not being excluded.
[0018] According to a further advantageous embodiment there is provided a process stage for converting the recorded vibration signals into acoustic signals by the electronic unit. The advantage of acoustic signals is that these can be easily processed and visualised by standard market-related audio software. Each circulating movement of the level rod can be represented by a peak, so that the size and regularity of the peaks allow conclusions regarding the strength of contact between the jet and the level rod. The acoustic signals can be recorded and evaluated immediately. The signals can be indicated by an indicator such as a monitor.
[0019] According to an advantageous embodiment, at least one parameter which is used for variably setting the maximum radial range of the jet can be controlled as a function of the recorded vibration signals. More particularly, the parameter(s) can already be controlled during said process, which means that the recorded information can be used immediately for controlling and influencing the production of the ground column. Parameters suitable for influencing the depth of penetration of the jet and thus the radius (and diameter respectively) of the ground column are, more particularly the rotational speed and/or the lifting speed and/or the jet pressure of the jet grouting tool.
[0020] Furthermore, the above objective is achieved by providing an assembly for determining the radius of a ground column produced by the jet grouting process, which assembly comprises: at least one level rod which can be introduced into the ground; a sensor which is connected to the level rod and which is able to record vibrations of the level rod; a jet grouting tool for producing a ground column; and an electronic unit which is connected to the sensor and which is able to further process data recorded by the sensor.
[0021] By means of the inventive assembly the advantages mentioned in connection with the proposed process can be achieved, to which reference is hereby made. Accordingly, said assembly, in an advantageous way, allows the measured values to be evaluated immediately and/or directly after the completion of the ground column, with these measured results allowing accurate conclusions regarding the radius and diameter respectively of the ground column.
[0022] According to a preferred embodiment, there are provided several level measuring indicators of which each comprises a vibration sensor. The at least one level rod is preferably provided in the form of a metal rod. Metal is advantageous in that its degree of conductivity of body-borne sound is high, as a result of which the vibration signal which is generated by the jet hitting the rod can easily be transmitted to the sensor. More particularly, the level rod can be provided in the form of a solid component which can easily transmit vibrations, but it is understood that a tubular member can also be used as a level rod. The vibration sensors can be piezo sensors for example which are fixed to the upper end of the rod and can record rod vibrations. More particularly, the piezo sensors can record accelerations which result from the vibrations the level rod. To that extent, an acceleration recorded by the piezo sensors constitutes a physical parameter which represents a vibration of the level rod. The vibrations of the level rod are transmitted via the direct connection with the sensor to said sensor. During the vibration recording process the sensor remains fixed to the level rod and in a stationary position. At the end of the vibration process, the sensor can be removed from the level rod.
[0023] According to an advantageous embodiment it is proposed that the electronic unit comprises a converter unit by means of which a vibration signal of the respective level rod can be converted into an acoustic signal. Furthermore, it is proposed to provide an evaluation device and/or an indicating device by means of which the acoustic signals can be evaluated or indicated.
[0024] The jet grouting tool can form part of a drilling device which carries the tool and by means of which the tool can be introduced into the ground.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] A preferred embodiment will be described below with reference to the drawing wherein
[0026] FIG. 1A illustrates a side view of the inventive assembly;
[0027] FIG. 1B illustrates a plan view of the inventive assembly;
[0028] FIG. 1C illustrates a front view of the inventive assembly showing a lowered jet grouting tool;
[0029] FIG. 2A illustrates distances of the level rods;
[0030] FIG. 2B illustrates the jet grouting tool in a first rotational position;
[0031] FIG. 2C illustrates the jet grouting tool in a second rotational position;
[0032] FIG. 3 shows an inventive process for determining the radius of a ground column produced by the jet grouting process; and
[0033] FIG. 4 shows an evaluation of vibration data based on the vibration signals recorded in accordance with the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0034] FIG. 1A - FIG. 4 will be described jointly below. They show an assembly 2 and a process for carrying out a process for determining the diameter of ground columns produced by a jet grouting process, respectively for determining the range of the jet of a jet grouting process. The assembly 2 comprises a jet grouting tool 3 and one or several level rods 4 with vibration sensors 5 , as well as an electronic unit 6 for evaluating vibration signals.
[0035] The jet grouting tool 3 forms part of drilling device 7 which is positioned on a ground surface 8 . A leader 9 is attached to the drilling device 7 . Said leader 9 comprises a longitudinally movable carrier device (slide) for carrying a jet grouting rod 10 for the jet grouting tool 3 . The jet grouting tool 3 comprises one or several exit nozzles 11 via which an injection material can be ejected through the jet grouting rod 10 into the in-situ soil 12 , and possibly a drilling crown 13 which is arranged at the end of the jet grouting rod 10 .
[0036] The jet grouting rod 10 is longitudinally movably connected to the leader mast 4 via the carrying device. At the upper end of the jet grouting rod 10 there is provided a flushing head 14 which can be moved vertically at the leader mast 4 , as well as a rotary drive 15 which serves to rotatably or pivotably drive the jet grouting rod 10 . The flushing head 14 which is also referred to a swivel serves to connect feed pipes for introducing the injection material. The injection material can be suspensions consisting of water and a bonding agent such as cement; optionally, they can also be surrounded by air. For the purpose of lowering the jet grouting tool 3 into the ground, the flushing head 14 and the jet grouting rod 10 are moved downwards.
[0037] Furthermore, the assembly 2 comprises level rods 4 , 4 ′ of which there are provided two in the present embodiment. Each level rod 4 , 4 ′ comprises a vibration sensor 5 , 5 ′ by means of which a signal representing vibrations can be recorded. For instance such a signal can be the body-borne sound or the vibrations, respectively accelerations of the level rod 4 , 4 ′ which are generated when a jet 16 hits the level rod 4 , 4 ′. The vibration sensors 5 , 5 ′ are attached to the respective level rod 4 , 4 ′ in such a way that the vibrations are transmitted directly from the rod to the sensor. During the process of recording the vibrations, the sensors 5 , 5 ′ remain stationary fixed in position at the respective level rod 4 , 4 ′. The vibration indicating sensors 5 , 5 ′ are each arranged at the upper end of the associated level rod 4 , 4 ′, which end can be for instance the free end of the rod 4 , 4 ′, as shown, or, generally speaking, it can be the rod portion which projects from the ground. The sensors 5 , 5 ′ are electronically connected to the electronic unit 6 to which the vibration signals are passed. In the present embodiment, the electronic connection is effected by electric lines 17 , but a wireless connection is also conceivable. The level rods 4 , 4 ′ are provided in the form of metal rods which can easily transmit vibrations or body-borne sound from regions in the ground to the region of the respective sensor 5 , 5 ′. The vibration sensors can be provided in the form of piezo sensors for example.
[0038] The electronic unit 6 comprises a converter device by means of which a vibration signal of the level rod 4 , 4 ′ can be converted into an acoustic signal. Furthermore, it can comprise an evaluation unit by means of which the acoustic signals can be evaluated. An audio analyser can be used to derive audio spectra from the vibration signals. An indicating device 18 (display) can be used to visualise the derived information. For this purpose, the electronic unit can comprise a peak/level indicator for example for the vibration sensor(s). The acoustic signals and the audio spectra respectively can optionally be stored by a recording unit, more particularly in a sound-data format such as MP3. Such data can be transmitted to a computer by means of a suitable interface such as a universal serial bus (USB).
[0039] The process is carried out as follows: during a first process stage S 10 the level rods 4 , 4 ′ are introduced into the ground. In the present embodiment there are provided two level rods 4 , 4 ′ which, in the assembly according to FIG. 1A-1C , are arranged at the same distance from the drilling axis A of the borehole to be produced. Alternatively, the distances of the two level rods from the axis of the ground member to be produced can differ, as shown in FIG. 2A-C , where the first distance B of the first level rod 4 is selected so as to be slightly longer than the required radius R of the ground column; the second distance B′ of the second level rod 4 ′ is again slightly longer than the first distance B. By positioning the level rods 4 , 4 ′ at different distances from the axis A, the diameter of the ground column to be produced can be determined and controlled particularly reliably because it is possible to obtain measurements for the different depths of penetration.
[0040] Irrespective of the distances among each other, the level rods 4 , 4 ′—with reference to the borehole and the axis A of the ground member to be produced—are preferably arranged such that their position at least corresponds to the radius R of the ground member to be produced, respectively to the penetration depth of the jet, i.e. it can be equal to or greater than the radius R. The distances B, B′ between the respective level rod and the borehole to be produced can range between 0.75 and 1.25 metres.
[0041] In the course of the next process stage S 20 , the jet grouting tool 3 , while rotating around its axis, is lowered into the ground down to its end depth T which marks the lower end point of the ground member to be produced. In principle, the jet grouting tool 3 can also be introduced into the soil without carrying out a rotational movement. The lowered condition of the jet grouting tool is shown in FIG. 1C . After the jet grouting tool 3 has reached the required end depth T, the ground member is produced.
[0042] The ground member is produced during process stage S 30 while the vibration signals are recorded at the same time. For this purpose, the jet grouting tool 3 is pulled upwards while rotating at the same time, more particularly up to the point of reaching the ground edge 8 , wherein, while the tool 3 is being pulled up, an injection material exits under a high pressure from one or several nozzles 11 , while eroding the surrounding ground and being mixed with same. After the bonding agent contained in the injection material has hardened, a ground member 19 is present which, for the sake of clarity, is shown in dashed lines in FIG. 1A-1C .
[0043] The rotational movement of the jet grouting tool 3 is defined by a phase angle φ as a function of time t. FIG. 2B shows the jet grouting tool 3 in a first rotational position in which the nozzle 11 respectively the jet 16 is arranged in a circumferential region between the two level rods 4 , 4 ′. In FIG. 2C , the jet grouting tool 3 has been rotated further around the drilling axis A, wherein, in the shown position, the jet 16 hits the first level rod 4 , thereby generating a vibration in the process. After the level rod 4 has been rotated further by 180°, the jet 16 points towards the second level rod 4 ′. Because the latter is further away from the tool axis A, either only slight or no vibrations can be measured here. The process is carried out from the bottom to the top. During the rotational and pulling movement of the jet grouting tool 3 —with an activated jet—vibrations of the level rods 4 , 4 ′ are recorded by the vibration sensors 5 , 5 ′.
[0044] In a subsequent process stage S 40 , the recorded vibration signals are further processed and evaluated by the electronic unit 6 , respectively by a computer connectable thereto.
[0045] Such an evaluation of the vibration signals is shown in FIG. 4 . In the upper row, a first vibration signal P 4 is shown as a function of time, which vibration signal 4 was determined from the vibrations recorded at the first level rod 4 . In the lower row a second vibration signal P 4 ′ is shown which is based on the vibrations recorded at the second level rod 4 ′. The diagrammatically illustrated acoustic vibrations signals allow conclusions regarding the depth of penetration of the jet 16 , whereby conclusions can be drawn regarding the diameter of the ground column produced.
[0046] If, for example, vibrations are determined at the first level rod 4 which is arranged so as to be closer to the jet grouting tool 3 , whereas no vibrations are recorded at the second level rod 4 ′ which is positioned further away from the second level rod 4 ′, it can be concluded that the radius of the ground column is positioned in the annular region between the first and the second level rod 4 , 4 ′. In the example shown in FIG. 2A-C , the first level rod is arranged at a distance of approximately 90 cm from the drilling axis and from the jet grouting tool respectively, whereas the second distance of the second level rod amounts to approximately 110 cm. It is understood that the level rods can also comprise the same distance from the axis A or that they can comprise distances from axis A which deviate from the values mentioned.
[0047] The inventive method of determining the depth of penetration of the jet of a jet grouting tool, and, respectively, the radius of ground columns produced by the jet grouting process, is advantageous overall in that it is possible to simultaneously record vibration data while producing the ground column and, optionally, evaluate same. Thus, the parameters affecting the depth of penetration of the jet can be controlled/changed quickly, so that the ground column to be produced comprises a high degree of dimensional accuracy. Reliable measurements can also be achieved in greater depths.
LIST OF REFERENCE NUMBERS
[0000]
2 assembly
3 jet grouting tool
4 level rod
5 sensor
6 electronic unit
7 drilling tool
8 ground surface
9 leader
10 jet grouting tool
11 exit nozzle
12 ground
13 drilling crown
14 flushing head/swivel
15 rotary drive
16 jet
17 pipeline
18 indicating device
19 ground member
A axis of rotation/column axis
B distance
R radius
T depth
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The invention relates to a method for determining the radius of a pile in the ground that can be produced by means of a jet-grouting process, comprising the steps of: introducing at least one level-measuring stick into the ground; sinking a jet-grouting tool ( 3 ) down to a defined distance from the level-measuring stick ( 4 ), the distance being less than a maximum range R of the grouting jet; pulling the jet-grouting tool ( 3 ) while performing a rotating or swivelling motion with the grouting jet activated, thereby producing vibrations as the grouting jet passes the level-measuring stick ( 4 ); and recording a signal representative of the vibrations at the at least one level-measuring stick ( 4 ) by means of a sensor ( 5 ) that is fastened to the level-measuring stick ( 4 ). The invention also relates to a corresponding arrangement ( 2 ) for determining the radius of a pile in the ground that can be produced by means of a jet-grouting process.
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FIELD OF THE INVENTION
[0001] The present invention relates to magnetic write heads and more particularly to a write head having a laminated trailing return pole structure for improved performance.
BACKGROUND OF THE INVENTION
[0002] The heart of a computer's long term memory is an assembly that is referred to as a magnetic hard disk drive. The magnetic hard disk drive includes a rotating magnetic disk, write and read heads that are suspended by a suspension arm adjacent to a surface of the rotating magnetic disk and an actuator that swings the suspension arm to place the read and write heads over selected circular tracks on the rotating disk. The read and write heads are directly located on a slider that has an air bearing surface (ABS). The suspension arm biases the slider toward the surface of the disk, and when the disk rotates, air adjacent to the disk moves along with the surface of the disk. The slider flies over the surface of the disk on a cushion of this moving air. When the slider rides on the air bearing, the write and read heads are employed for writing magnetic transitions to and reading magnetic transitions from the rotating disk. The read and write heads are connected to processing circuitry that operates according to a computer program to implement the writing and reading functions.
[0003] The write head can include a coil that passes through a magnetic yoke that includes a write pole located between leading and trailing return poles. Current conducted to the coil layer induces a magnetic flux in the pole pieces which causes a write field to emit from the write pole for the purpose of writing a magnetic transition in tracks on the moving media, such as in circular tracks on the rotating disk. The write field passes through a magnetically soft under-layer of the magnetic media and returns to the return poles where it is sufficiently spread out and weak that it does not erase the previously recorded bit.
[0004] In the quest for every increased data capacity and data rate, researchers have sought means for improving the performance of such magnetic write heads. Such an increase in performance can include maximizing the write field strength as well as minimizing the time necessary to switch the magnetic polarization of the poles of the magnetic write head (e.g. maximizing switching speed).
SUMMARY OF THE INVENTION
[0005] The present invention provides a perpendicular magnetic write head having a laminated return pole structure for improved magnetic performance. The return pole includes magnetic layers that are each separated from one another by a non-magnetic layer that terminates at a location that is recessed from the air bearing surface, thereby allowing the magnetic layers to contact one another at the air bearing surface while being separated from one another in a region removed from the air bearing surface.
[0006] The laminated structure of the return pole prevents eddy current formation, thereby improving the performance of the write head. If the non-magnetic lamination layers were allowed to extend all of the way to the air bearing surface a magnetic fringing field would extend from the ends of the magnetic layers in order to form a flux closure path between adjacent magnetic layers. This would then lead to stray field formation and inadvertent writing to the magnetic media. This is prevented by terminating the non-magnetic layers at a location, that is recessed from the air bearing surface.
[0007] These and other features and advantages of the invention will be apparent upon reading of the following detailed description of preferred embodiments taken in conjunction with the Figures in which like reference numerals indicate like elements throughout.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] For a fuller understanding of the nature and advantages of this invention, as well as the preferred mode of use, reference should be made to the following detailed description read in conjunction with the accompanying drawings which are not to scale.
[0009] FIG. 1 is a schematic illustration of a disk drive system in which the invention might be embodied;
[0010] FIG. 2 is an ABS view of a slider, taken from line 2 - 2 of FIG. 1 , illustrating the location of a magnetic head thereon; and
[0011] FIG. 3 is a side cross sectional view of a magnetic write head according to an embodiment of the invention; and
[0012] FIG. 4 is an enlarged cross sectional view of a magnetic write head according to an alternate embodiment of the invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0013] The following description is of the best embodiments presently contemplated for carrying out this invention. This description is made for the purpose of illustrating the general principles of this invention and is not meant to limit the inventive concepts claimed herein.
[0014] Referring now to FIG. 1 , there is shown a disk drive 100 embodying this invention. As shown in FIG. 1 , at least one rotatable magnetic disk 112 is supported on a spindle 114 and rotated by a disk drive motor 118 . The magnetic recording on each disk is in the form of annular patterns of concentric data tracks (not shown) on the magnetic disk 112 .
[0015] At least one slider 113 is positioned near the magnetic disk 112 , each slider 113 supporting one or more magnetic head assemblies 121 . As the magnetic disk rotates, slider 113 moves radially in and out over the disk surface 122 so that the magnetic head assembly 121 can access different tracks of the magnetic disk where desired data are written. Each slider 113 is attached to an actuator arm 119 by way of a suspension 115 . The suspension 115 provides a slight spring force which biases slider 113 against the disk surface 122 . Each actuator arm 119 is attached to an actuator means 127 . The actuator means 127 as shown in FIG. 1 may be a voice coil motor (VCM). The VCM comprises a coil movable within a fixed magnetic field, the direction and speed of the coil movements being controlled by the motor current signals supplied by controller 129 .
[0016] During operation of the disk storage system, the rotation of the magnetic disk 112 generates an air bearing between the slider 113 and the disk surface 122 which exerts a force on the slider. The air bearing thus counter-balances the slight spring force of suspension 115 and supports the slider 113 off and slightly above the disk surface by a small, substantially constant spacing during normal operation.
[0017] The various components of the disk storage system are controlled in operation by control signals generated by control unit 129 , such as access control signals and internal clock signals. Typically, the control unit 129 comprises logic control circuits, storage means and a microprocessor. The control unit 129 generates control signals to control various system operations such as drive motor control signals on line 123 and head position and seek control signals on line 128 . The control signals on line 128 provide the desired current profiles to optimally move and position slider 113 to the desired data track on disk 112 . Write and read signals are communicated to and from write and read heads 121 by way of recording channel 125 .
[0018] With reference to FIG. 2 , the orientation of the magnetic head 121 in a slider 113 can be seen in more detail. FIG. 2 is an ABS view of the slider 113 , and as can be seen the magnetic head including an inductive write head and a read sensor, is located at a trailing edge of the slider. The above description of a typical magnetic disk storage system and the accompanying illustration of FIG. 1 , are for representation purposes only. It should be apparent that disk storage systems may contain a large number of disks and actuators, and each actuator may support a number of sliders.
[0019] FIG. 3 shows a magnetic write head 300 according to an embodiment of the invention. The write head includes a lower or leading magnetic return pole (P 1 ) 302 , a write pole structure (P 2 ) 306 , and an upper or trailing return pole structure (P 3 ) 308 . The leading return pole 302 can be connected with the write pole structure by a magnetic back gap layer 310 .
[0020] The write pole structure 306 can include a main write pole 312 that is located between first and second shaping layers 314 , 316 . The main write pole 312 extends to the ABS, but the first and second shaping layers 314 , 316 stop short of the ABS. The main write pole 312 can be separated from the first and second shaping layer 314 , 316 by thin non-magnetic layers 318 , 320 , which can be, for example, alumina. Alternatively, the non-magnetic layers 320 , 318 could be eliminated so that the write pole 312 contacts both of the shaping layers 314 , 316 . In addition, one of the shaping layers 314 , 316 could be eliminated so that there is only one shaping layer.
[0021] A trailing magnetic shield 322 may be provided to improve the field gradient of the write field emitted from the write pole 312 . The trailing magnetic shield 322 is separated from the trailing edge of the write pole 312 by a thin, non-magnetic trailing gap layer 324 . A non-magnetic fill layer 326 such as alumina may be provided to fill the space behind the trailing shield 322 . The trailing shield 322 is magnetically connected with the trailing return pole 308 .
[0022] The write head 300 also includes a write coil 328 . The write coil 328 can be constructed of a non-magnetic, electrically conductive material such as Cu and can be constructed as a pair of pancake coils or as a helical coil. The lower portion of the write coil 328 is embedded in a lower insulation layer 330 that can be a material such as alumina. The upper portion of the write pole 328 is embedded in an upper insulation layer 332 that can be a material such as hard baked photoresist, or could be alumina like the lower insulation layer 330 .
[0023] When an electrical current flows through the write coil, a magnetic field is induced around the turns of the write coil. This causes a magnetic flux to flow through the write pole structure 306 , resulting in a magnetic write field 334 being emitted from the tip of the write pole 312 in a direction that is substantially perpendicular to the ABS and to the surface of the media 112 and which locally magnetizes a hard magnetic layer 336 of the magnetic media 112 . The majority of the write field 334 then travels through a magnetically softer under-layer 338 and through an air gap between 344 and 322 to the trailing magnetic shield 322 . The flux return path continues with return pole 308 , 340 ( a ), 340 ( b ), 320 , 314 , 322 . Therefore, reducing the flux return reluctance, such as 308 , 340 ( a ), 340 ( b ) is beneficial in enhancing the writing switch time.
[0024] At high data rate, the eddy current increases the flux reluctance of 308 , 340 ( a ), 340 ( b ) significantly. One way to improve the performance of the write head 300 is to reduce the eddy current loss in the trailing return pole 308 , 340 ( a ), 340 ( b ) such as by forming the majority of the return path with lamination such as 340 ( a ) and 340 ( b ).
[0025] To this end, the trailing return pole 308 is constructed as a laminated structure having magnetic layers 340 ( a ), 340 ( b ) that are separated from one another by a thin layer of non-magnetic, dielectric material such as alumina 342 , which can be deposited by a process such as atomic layer deposition, chemical vapor deposition, sputter deposition or ion beam deposition. The magnetic layers 340 ( a ), 340 ( b ) can be constructed of a high Bsat material such as CoFe, NiFe, which is preferably formed by electroplating.
[0026] A laminated pole structure can cause unintended writing to the magnetic media 112 if the pole 308 is laminated all of the way to the ABS. If the lamination structure were to extend all of the way to the ABS, a flux closure path would exist at the ABS forming a magnetic field at the ABS that has a component that is perpendicular to the surface of the magnetic media. This of course would be unacceptable.
[0027] The present invention solves this problem by terminating the non-magnetic layer 342 at some point short of the ABS. Therefore, while the magnetic layers 340 ( a ), 340 ( b ) are separated from one another in regions removed from the ABS, they are in contact with one another near the ABS.
[0028] FIG. 3 shows a laminated trailing return pole structure 308 that has only two magnetic layers 340 ( a ), 340 ( b ) and one non-magnetic lamination layer 342 . This is, however, by way of example only as there could be any number of laminations. However, the cost and complexity of constructing the write head 300 increases with increasing number of laminations. In another embodiment of the invention, as shown in FIG. 4 , a write head 400 is shown having a trailing return pole 402 that has several laminations. In this embodiment the trailing return pole 402 has 4 magnetic layers 340 ( a ), 340 ( b ), 340 ( c ), 340 ( d ), although the return pole could have any number of magnetic layers 340 and non-magnetic layers 342 , such as three magnetic layers 340 or five or more magnetic layers 340 . Each magnetic layer 340 is separated from an adjacent magnetic layer (in a region removed from the ABS) by a non-magnetic layer 342 ( a ), 342 ( b ), 342 ( c ). As with the previously described embodiment, the non-magnetic layers 342 ( a ), 342 ( b ), 342 ( c ) terminate short of the ABS, so that magnetic layers 340 ( a - d ) contact one another in the region near the ABS. Again, this structure avoids forming magnetic fields at the ABS (which might write to the media) while still preventing the formation of eddy currents in the trailing return pole.
[0029] In order to construct a write head according to the invention, a first magnetic layer ( 340 ( a ) of FIG. 3 or 4 ) is formed by electroplating. An ion milling is then performed to remove the electroplating seed layer used to facilitate the electroplating process. Then, a thin non-magnetic layer such as alumina is deposited by a method such as sputtering, ion beam deposition, atomic vapor deposition or chemical vapor deposition. This non-magnetic layer is formed to terminate short of the ABS plane by either a liftoff process or by depositing the non-magnetic layer full film, forming a mask structure over the non-magnetic layer and then ion milling. Then, a second layer of magnetic material is formed by electroplating and another ion milling is performed to remove the seed layer that was used in the second electroplating process. This series of steps can be repeated as often as needed depending on the number of laminations desired.
[0030] While various embodiments have been described above, it should be understood that they have been presented by way of example only, and not limitation. Other embodiments falling within the scope of the invention may also become apparent to those skilled in the art. Thus, the breadth and scope of the invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.
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A perpendicular magnetic write head having a laminated trailing return pole structure that reduces magnetic eddy currents in the return pole for improved write head efficiency. The trailing magnetic return pole includes multiple magnetic layers. Each magnetic layer is separated from an adjacent magnetic layer of the return pole by a non-magnetic layer. The non-magnetic layer terminates at a region that is removed from the air bearing surface in order to allow contact between the magnetic layers at the ABS, thereby preventing stray magnetic fields from emitting from the magnetic layers of the write pole.
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CROSS-REFERENCE TO RELATED APPLICATION
This is a continuation, under 35 U.S.C. §120, of copending International Application No. PCT/EP2010/062805, filed Sep. 1, 2010, which designated the United States; this application also claims the priority, under 35 U.S.C. §119, of German Patent Application DE 10 2009 041 090.2, filed Sep. 14, 2009; the prior applications are herewith incorporated by reference in their entirety.
BACKGROUND OF THE INVENTION
Field of the Invention
The present invention relates to a device for treating exhaust gas containing soot particles, in particular with a so-called electrostatic filter or electric filter, as well as a suitable method for converting soot particles of an exhaust gas. The invention is used, in particular, in the treatment of exhaust gases of mobile internal combustion engines in the field of automobiles, in particular in the treatment of exhaust gases resulting from diesel fuel.
A multiplicity of different concepts for eliminating soot particles from exhaust gases of mobile internal combustion engines have already been discussed. In addition to wall-flow filters which are alternately closed, open secondary flow filters and gravity precipitators, etc., systems have already been proposed in which the particles in the exhaust gas are charged electrically and then deposited by using electrostatic attraction forces. Those systems are known, in particular, by the term “electrostatic filter” or “electric filter.”
Generally (a plurality of) discharge electrodes and collector electrodes, positioned in the exhaust line, are proposed for such electric filters. In that context, for example, a central discharge electrode which runs approximately centrally through the exhaust line and a surrounding lateral surface of the exhaust line as a collector electrode are used to form a capacitor. Through the use of that configuration of the discharge electrode and the collector electrode, an electrical field is formed transversely with respect to the direction of flow of the exhaust gas, wherein the discharge electrode can be operated, for example, with a high voltage which is in the range of approximately 15 kV. As a result, in particular corona discharges can be formed through which the particles which flow through the electrical field with the exhaust gas are charged in a unipolar fashion. As a result of that charging, the particles migrate to the collector electrode due to electrostatic Coulomb forces.
In addition to systems in which the exhaust line is embodied as a collector electrode, systems are also known in which the collector electrode is embodied, for example, as a wire mesh. In that context, the accumulation of particles on the wire mesh serves the purpose of combining the particles, where appropriate, with further particles in order to therefore form an agglomeration. The exhaust gas which flows through the mesh or grid then carries the relatively large particles along with it again and carries them to conventional filter systems.
Even if the systems described above have heretofore proven suitable for the treatment of soot particles, at least in trials, the implementation of that concept for series production in motor vehicles presents serious challenges. That applies, in particular, with respect to the greatly fluctuating, at times very heavy, soot load in the exhaust gas, as well as the desired retrofitability of such a system for currently existing exhaust systems. In addition, it is necessary to take into account the fact that the improved performance of such exhaust systems in terms of the elimination of soot particles also makes it necessary to perform (periodic or continuous) regeneration of the filter systems, involving the soot being converted into gaseous components.
With respect to the regeneration of filter systems, it is also known, in addition to the intermittent regeneration by brief heating, that is to say burning off of the soot (catalytically motivated oxidative conversion), to convert soot through the use of nitrogen dioxide (NO 2 ). The advantage of continuous regeneration with nitrogen dioxide is that the conversion of soot can already take place in that case at significantly lower temperatures (in particular lower than 250° C.). For that reason, continuous regeneration is preferred in many applications. However, that leads to the problem that it is necessary to ensure that the nitrogen dioxide in the stream of exhaust gas comes into contact to a sufficient degree with the deposited soot particles.
In that context, there are also technical difficulties in the implementation of continuous operation of such exhaust systems in motor vehicles, wherein the different loadings of the internal combustion engines lead to different streams of exhaust gas, compositions of exhaust gas and temperatures.
SUMMARY OF THE INVENTION
It is accordingly an object of the invention to provide a device and a method for treating exhaust gas containing soot particles, which overcome the hereinafore-mentioned disadvantages and at least partially solve the highlighted problems of the heretofore-known devices and methods of this general type. In particular, the intention is to describe a device for treating exhaust gas containing soot particles, which similarly makes a large precipitation effect available for soot particles and which can be satisfactorily regenerated. The intention is also to specify a corresponding method for converting soot particles of an exhaust gas. The device and the method are to be easily integrated into existing mobile exhaust systems and are to be equally capable of being manufactured cost-effectively.
With the foregoing and other objects in view there is provided, in accordance with the invention, a device for treating exhaust gas containing soot particles. The device comprises at least one source of nitrogen dioxide or oxygen, at least one ionization element for ionizing soot particles, at least one neutralization element for neutralizing electrically charged soot particles, at least one surface precipitator having an inlet region, an outlet region and a plurality of channels through which the exhaust gas can flow, the channels extending between the inlet region and the outlet region, and at least one deposition inhibitor disposed at least partially at the inlet region for inhibiting deposition of electrically charged soot particles.
The device proposed herein may, in particular, be part of an exhaust system of a motor vehicle which has a diesel engine. However, the device can also be made available as a modular kit for an exhaust system.
Accordingly, firstly a nitrogen dioxide source is provided. Such a nitrogen dioxide source is, for example, a catalytic converter which assists (together with other components of the exhaust gas, in particular oxygen) the conversion of nitrogen oxides (in particular nitrogen monoxide NO) contained in the exhaust gas into nitrogen dioxide. Basically, a plurality of such nitrogen dioxide sources may also be present, but this is not absolutely necessary. The nitrogen dioxide source can usually be implemented with a catalytic converter which has a honeycomb body with a coating, wherein the coating has platinum, rhodium, palladium or the like. The nitrogen dioxide source is therefore connected downstream of the internal combustion engine, and is therefore located at least partially in the exhaust system.
While the nitrogen dioxide source is usually preferably used in relatively “cold exhaust systems” (for example diesel engine applications), an oxidative conversion of the soot particles with oxygen from an oxygen source can also be carried out at relatively high temperatures (for example gasoline engine applications). For example, the internal combustion engine itself or a so-called secondary air input, that is to say, in particular, the feeding in of an oxygen-containing gas into the exhaust line, is preferably considered as an oxygen source. If appropriate, chemical conversion with a catalyst can also generate oxygen, so that this can also be considered as an oxygen source.
In particular, a device which alternatively has at least one nitrogen dioxide source or at least one oxygen source upstream of the surface precipitator in the exhaust line is preferred.
Furthermore, at least one ionization element for ionizing soot particles is provided. It is preferred in this case that the exhaust gas firstly reaches the nitrogen dioxide source before it reaches the section of the device with the at least one ionization element. The ionization element preferably includes an ionization electrode or a multiplicity of ionization electrodes. The at least one ionization element is connected to a voltage source, in particular to a high voltage source. It is also possible to regulate the voltage through the use of a control unit. Basically, a direct-current voltage source or an alternating-current voltage source can be made available.
Furthermore, at least one neutralization element for neutralizing electrically charged soot particles is provided. The at least one neutralization element carries out at least the task of feeding electrical charge to the electrically charged soot particles or discharging it therefrom (depending on the electrical charge), as a result of which, when contact occurs with the electrically charged soot particles, electrical neutralization or de-ionization of the soot particles takes place. The number of ionization elements and neutralization elements basically does not have to correspond, but it may be expedient that they do.
An electrical field is usually formed between the at least one ionization element and the at least one neutralization element. This electrical field extends, in particular, in the direction of the exhaust system and/or in the direction of flow of the exhaust gas, wherein the exhaust gas firstly reaches the at least one ionization element and later the at least one neutralization element. As a result, the at least one ionization element and the at least one neutralization element are offset with respect to one another in the direction of flow of the exhaust gas, in particular at a distance of several centimeters such as, for example, at least 5 cm, at least 15 cm or even at least 30 cm.
Furthermore, at least one surface precipitator is provided. The surface precipitator is distinguished by having a plurality of channels through which the exhaust gas flows, and by the channels extending between an inlet region and an outlet region. Basically, it would be possible to form a surface precipitator which only has two channels, but an embodiment in which a plurality of channels are provided, for example at least 30, at least 50 or even at least 100 channels, is preferred. The term “surface precipitator” is intended to express the fact that a surface which is very large (in particular also in relation to its volume) is made available for the accumulation of soot particles. In contrast to known variants, in which, where possible, the soot particles were agglomerated one on top of the other in a tightly limited space, the objective in this case is to distribute the soot particles over a large area over the surfaces of the channel walls which are formed by the channels. However, this does not rule out the possibility of the soot particles being deposited, for example, also in the interior of a porous channel wall. In particular, the external and internal surfaces of the channel walls can therefore in this case be considered to be surfaces which are suitable for the depositing of soot. A “channel” is understood herein to be, in particular, a delimited flow path having an extent which is clearly longer than its diameter, wherein the diameter is, in particular, significantly greater than the customary sizes of the soot particles. Even if it is sufficient for some purposes to form separate and discrete channels, communicating channels can nevertheless also be made available in which an exchange of partial streams of exhaust gas (for example through openings in the channel walls) is made possible. Providing channels with an extent of, for example, at least 5 cm, but preferably even at least 10 cm, which are, in particular, relatively small in cross section, readily permits the individual channels or surface precipitator to be configured in a way which is adapted to the flow profile.
However, in order to ensure that in fact there is no accumulation of soot particles in just one plane perpendicularly with respect to the direction of flow (as in the case of a grid or screen), at least one deposition inhibitor for electrically charged soot particles is provided at least partially at the inlet region. This inhibitor carries out the function of preventing deposition (exclusive or predominant) of the electrically charged soot particles in the inlet region. In this context, the deposition inhibitor can be configured in such a way that it is configured only for some of the channels or configured differently for the channels. The deposition inhibitor can, on one hand, relate to the surface precipitator itself, but it is also possible for the at least one deposition inhibitor to act on the stream of exhaust gas and therefore bring about a changed routing of the stream of exhaust gas through the surface precipitator. For this purpose, the at least one deposition inhibitor can be formed in a slightly offset fashion directly at the inlet region and/or starting from the inlet region in the direction of the outlet region. Under certain circumstances it is also possible for such a deposition inhibitor also to be provided for at least some of the channels from the inlet region to the outlet region. The configuration and/or distribution of the at least one deposition inhibitor for electrically charged soot particles in the surface inhibitor is to be selected in such a way that soot particles are deposited as uniformly as possible on the channel walls of the multiplicity of channels (and not only on the front face). This leads, in particular, to a situation in which the deposited soot particles are disposed over a large surface, that is to say at a relatively large distance from one another, even in the case of a briefly increased soot load of the exhaust gas. This provides, in a particular way, the possibility of regenerating the soot particles there continuously with nitrogen dioxide. This is promoted by the fact that the exhaust gas, which is conducted through the channels over a relatively long flow path and at a short distance from the channel wall, has the possibility of bringing about a conversion with small particles which are relatively free there. This results in a situation in which, in particular, an undesired drop of pressure over the surface inhibitors is avoided as the load with soot particles increases, since particularly effective continuous regeneration of the surface precipitator is carried out.
In accordance with another preferred feature of the invention, the at least one neutralization element is formed in the vicinity of the outlet region of the at least one surface precipitator. This is intended to mean, in particular, that the at least one neutralization element forms part of the outlet region, wherein it may be, in particular, part of the surface precipitator, may be positioned in (electrical) contact therewith or else may be disposed downstream thereof in the direction of flow. The at least one neutralization element can accordingly be accommodated in the surface precipitator, but a separate, downstream refinement of the at least one neutralization element is also possible. If the at least one neutralization element is an integral component of the surface precipitator, the surface precipitator simultaneously performs the function of neutralization, with the result that ultimately electrically neutral soot particles are deposited on the surfaces of the surface precipitator. If the at least one neutralization element can be formed downstream of the surface precipitator, the latter can be embodied in the manner of a conventional collector electrode in order to form the electrical field through the surface precipitator. The channels are then configured, in particular, in such a way that the electrically charged soot particles impinge on the channel wall due to the electrical forces.
It is preferred that the ionization element be disposed upstream of the surface precipitator in the direction of flow of the exhaust gas, as a result of which ionization of the soot particles occurs upstream of the surface precipitator. It is particularly preferred if the ionization element is disposed at a distance of at least 5 cm, in particular of at least 10 cm, upstream of the surface precipitator. The surface precipitator therefore does not serve to perform ionization but rather basically only as a collector for the soot particles which are already ionized (upstream).
In accordance with a further particularly preferred feature of the invention, the at least one surface precipitator is embodied as a honeycomb body. Such honeycomb bodies can basically be constructed with different materials, in particular also with metallic and/or ceramic components. The manufacturing methods for such honeycomb bodies have been known for many years and the honeycomb bodies have proven particularly suitable in terms of formation of contact between the stream of exhaust gas and the walls in the channels. In this case, the honeycomb body can have (only) open and/or (partially) closed channels. Basically, it is preferred that the channels extend substantially linearly and parallel to one another (such as, for example, in the case of an extruded honeycomb body), but this is not absolutely necessary. The channels and/or the channel walls can also be embodied with structures (grooves, knobs, sliding surfaces, etc.) in order to implement an additional improvement of the formation of contact between the retained soot particles and the nitrogen dioxide from the exhaust gas. As a result, the structure extends from the channel wall into the channels and, in particular, constricts the channel cross section. The channel walls may be impermeable and/or permeable to gas in this case, with it being possible to implement the latter by porosity of the material and/or by openings (for example holes).
In accordance with an added feature of the invention, various refinements of the at least one deposition inhibitor can be assigned to the channels. That is to say in other words, in particular, that during operation the at least one deposition inhibitor results in different deposition regions of the individual channels being influenced chronologically and/or spatially. Deposition inhibitors can therefore be embodied differently in the region of the centrally disposed channels than the deposition inhibitors in the channels in the edge region of the surface precipitator. Alternatively or cumulatively, it is possible to embody the deposition inhibitors near the inlet region differently than in the region of the outlet region for a number of channels. If the surface precipitator is itself a neutralization element, it is therefore possible to implement different electrical conductivity of the channel wall in particular in the profile direction of the channels and/or as a function of the position of the channels, as a result of which the embodiment of the electrical field and therefore the effect of the Coulomb's forces on the electrically charged soot particles is adapted.
In accordance with an additional feature of the invention, the at least one deposition inhibitor extends in various axial zones of the channels. Consequently, in some of the channels, a deposition inhibitor may be embodied from the inlet region to several millimeters into a channel, but it is also possible for the deposition inhibitor to extend as far as the outlet region. In this context, a plurality of deposition inhibitors (of the same type and/or different) can also be provided in the respective channels.
In accordance with yet another feature of the invention, the at least one deposition inhibitor is formed by various channel forms or shapes. In this specific embodiment of the surface precipitator, in particular if the latter constitutes a neutralization element, it should be made possible that the probability of impacting and/or the depositing capability and/or the flow paths for soot particles be adapted to the flow profile of the exhaust gas and/or the exhaust gas volume flow. This is intended, in particular to counteract a situation in which different quantities of particles are made to flow into the channels. Instead, it is possible to implement a situation in which there are differing (and on average therefore uniform) flows into the channels given different streams of exhaust gas. The term “channel shape” therefore includes considering its cross section and the profile shape of the channel. Different channel shapes are provided, in particular, when the channels differ in one of the following properties: size (diameter) of the channel cross section, shape of the channel cross section, inclination of the channel profile, curvature of the channel profile, widening of the channel profile, constriction of the channel profile, position and/or type of the structures of the channel walls, etc.
In accordance with yet a further feature of the invention, channels in which there is a central flow are made at least larger or more structured than channels in which there is an off-center flow. This means, in other words, that relatively large channel cross sections and/or a smaller channel density is provided in the central region of the surface precipitator, and/or in the region thereof in which there is a central flow, than in the region of the surface precipitator which is off-center or near the edge. Alternatively or cumulatively to this, it is possible for the channel walls of the channels in which there is a central flow to be embodied to a relatively large degree with structures, that is to say with respect to the size of the structures, the frequency of the structures, etc. This measure takes into account, in particular, the fact that the pressure loss of the exhaust gas increases quadratically with the mass flow of exhaust gas as it flows through the surface precipitator. The provision of structures in the central region then leads to a situation in which overproportionally large parts of the stream of exhaust gas are also conducted into the edge regions for this part, with the result that in total approximately the same flow can be detected in the channels.
In accordance with yet an added feature of the invention, the at least one deposition inhibitor can be formed by at least one electrical insulator. In particular, ceramic coating is possible for this purpose. The coating can also be applied, for example, on metal surfaces. Alternatively, separate components which form an electrical insulator can also be added.
In accordance with yet an additional feature of the invention, it is basically also possible for the at least one surface precipitator to have, as a basic material, an electrical insulator which forms a deposition inhibitor, that is to say in other words, that the surface precipitator itself has at least partially no electrical conductivity. Then, in particular, by taking into account the channel shape (for example twisted and/or structured channels) or the concept of the surface precipitator (for example wall-flow filter with alternately closed channels) it is possible to ensure that the particles can be deposited on or in this basic material.
In accordance with again another feature of the invention, in order to also achieve the selective desposition of particles in a uniform fashion in this case over the entire surface of the surface precipitator, it is possible to integrate electrical conductivity, for example in such a way that the surface precipitator has at least one neutralization element, wherein the at least one neutralization element is embodied differently in the channels. Consequently, electrically conductive materials can be disposed in and/or on the basic material of the surface precipitator and are connected to an electrical ground. This can be achieved by correspondingly electrically conductive conductors, fibers, particles and the like (which are, if appropriate, in contact with one another). In particular, metal inlays are suitable for this purpose.
The surface precipitator preferably has porous channel walls which are formed in particular, with sintered material, ceramic, silicon carbide (SiC) or mixtures thereof. This is particularly preferably an (at least partially) extruded honeycomb body.
With the objects of the invention in view, there is also provided a method for converting soot particles of an exhaust gas. The method comprises:
a) providing at least nitrogen dioxide or oxygen in the exhaust gas; b) ionizing soot particles with an electrical field; c) depositing electrically charged soot particles on inner channel walls of at least one surface precipitator; and d) placing at least nitrogen dioxide or oxygen in contact with the soot particles deposited on the inner channel walls of the at least one surface precipitator.
As a result, in particular continuous regeneration of soot particles is also specified with the device proposed according to the invention. For this reason it is also necessary to point out that the features which are presented with respect to the devices can be used to explain the method, and vice-versa. It is also necessary to note that the steps a) and b) can be carried out in succession and/or simultaneously, wherein emphasis is placed on the respective effect on a partial stream of exhaust gas. It is preferred that all of the steps a) to d) be carried out continuously during the operation of a mobile internal combustion engine. Furthermore it is preferred that step a) alternatively includes the provision/generation of nitrogen dioxide or oxygen within the exhaust line.
In accordance with another mode of the method of the invention, the flow behavior of the exhaust gas through the channels of the at least one surface precipitator or the configuration of the electrical field is varied as a function of an exhaust gas parameter. If appropriate, it is also possible to carry out both measures simultaneously or alongside one another. The flow behavior can be changed independently, for example by correspondingly configuring the surface precipitator with the result that there is a flow through different channels given differing flow behavior. However, it is also possible to perform active variation in that, for example, the frequency and/or field strength of the electrical field are regulated. In particular, the temperature, the mass flow, the volume flow and/or the flow speed of the exhaust gas are considered as exhaust gas parameters. Of course, other characteristic values of the operation of the internal combustion engine can also be used as an alternative thereto or additionally in order to draw conclusions about a corresponding exhaust gas parameter.
In accordance with a further mode of the invention, the method serves preferably to perform continuous regeneration of the at least one surface precipitator. For this purpose, the soot is placed in contact with nitrogen dioxide which has been generated upstream in the flow of exhaust gas, and is chemically converted. For a further explanation, recourse can be made to the so-called CRT method (CRT=Continuous Regeneration Trap) which is disclosed, for example, in European Patent Application EP 0 341 832, corresponding to U.S. Pat. No. 4,902,487.
In accordance with a concomitant mode of the invention, a method is also preferred in which the electrically charged soot particles are deposited uniformly on all of the channels of the at least one surface precipitator. This is to be understood, in particular, as meaning that the device and/or the surface precipitator is configured in such a way that the probability of deposition of the electrically charged soot particles on all of the inner channel faces of the surface precipitator is substantially the same. The measures which are to be taken, if appropriate, to achieve this have already been presented above.
The invention is preferably used in a motor vehicle having an internal combustion engine, in particular a diesel engine, with a downstream exhaust system which has a device according to the invention. For this purpose, the motor vehicle has, for example, a control unit for operating this device with the method according to the invention, wherein the control unit is configured, in particular through the use of corresponding software, to implement the operation according to the invention during the operation of the motor vehicle. If appropriate, the control unit can interact with sensors of the exhaust system and/or of the internal combustion engine and/or stored data models in order to adapt this system.
Other features which are considered as characteristic for the invention are set forth in the appended claims, noting that the features which are disclosed individually in the claims can be combined with one another in any desired technologically appropriate way and indicate further embodiments of the invention.
Although the invention is illustrated and described herein as embodied in a device and a method for treating exhaust gas containing soot particles, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, 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 SEVERAL VIEWS OF THE DRAWING
FIG. 1 is a diagrammatic, longitudinal-sectional view of a first embodiment variant of a device according to the invention;
FIG. 2 is an enlarged, fragmentary, longitudinal-sectional view of a first embodiment variant of a surface precipitator;
FIG. 3 is a fragmentary, longitudinal-sectional view of a second variant of a surface precipitator;
FIG. 4 is a fragmentary, longitudinal-sectional view of a third embodiment variant of a surface precipitator;
FIG. 5 is a longitudinal-sectional view of a further embodiment variant of the device;
FIG. 6 is a diagram illustrating the method according to the invention;
FIG. 7 is an illustration of attraction forces acting on a soot particle; and
FIG. 8 is a longitudinal-sectional view of a further embodiment variant of a surface precipitator.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the figures of the drawings in detail and first, particularly, to FIG. 1 thereof, there is seen a first exemplary embodiment of a device 1 according to the invention. In this case, exhaust gas flows in a flow direction 31 through an exhaust system, which is illustrated herein in an approximately tubular shape, although that is not significant. The exhaust gas contains soot particles 2 . The exhaust gas with the soot particles 2 is firstly conducted through a nitrogen dioxide source 3 , in particular through a honeycomb-shaped catalytic converter with a platinum coating. This nitrogen dioxide source converts nitrogen monoxides (NO) contained in the exhaust gas into nitrogen dioxides (NO 2 ), as a result of which the proportion of nitrogen dioxides in the exhaust gas is increased (making up, in particular, at least 25% by weight or even at least 50% by weight of the entire nitrogen oxides). The exhaust gas which is prepared in this way flows on to an (individual) surface precipitator or collector 6 . The surface precipitator 6 has an inlet region 8 and an outlet region 9 . Linear channels 7 , which extend parallel to one another, run between the inlet region 8 and the outlet region 9 . The channels 7 are embodied in this case (partially) with a catalytic coating 18 , but this is not absolutely necessary.
Before the exhaust gas reaches the surface precipitator 6 , it enters an electrical field which is formed through the use of an ionization element 4 upstream of the surface precipitator 6 and a neutralization element 5 at the outlet region 9 of the surface precipitator 6 . In the illustrated case, the neutralization element 5 is integrated into the channel walls of the surface precipitator 6 . In order to prevent electrically charged soot particles from impacting directly on the front face of a honeycomb body in the vicinity of the inlet region 8 , and so that the channels 7 themselves no longer serve for the accumulation of soot particles, a deposition inhibitor 10 is formed in the vicinity of the inlet region 8 . This deposition inhibitor 10 actually reduces or prevents accumulation there. Different refinements of this deposition inhibitor 10 are also presented with reference to the following figures.
FIG. 2 shows, for example, details of a surface precipitator having a multiplicity of channels 7 which are bounded by channel walls 17 . As a result, in particular, a so-called honeycomb body 11 is formed. In order to prevent the soot particles from being deposited only in the inlet region 8 of the honeycomb body 11 , an electrical insulator 15 (embodied in the manner of a coating on the channel walls) is provided there as a deposition inhibitor. This figure also indicates that the embodiment of the deposition inhibitor or, as shown herein, of the electrical insulator, can relate to different zones 12 of the channels 7 . The zones 12 can therefore differ from one another, in particular in terms of their extent and/or position.
FIG. 3 shows an embodiment variant of a honeycomb body 11 which is formed with conically and/or tapering/widening channels 7 . While the channel shape 13 in FIG. 2 is, for example, substantially round and is constant over its length, the cross section in the case of the conical channel shape changes in its longitudinal direction. Due to the changed channel cross sections, the flow can also be influenced in this case and/or deposition of soot particles can also be achieved in the rear part of the honeycomb body 11 . An oxygen source 32 is also indicated in purely schematic form upstream of this honeycomb body 11 . It is possible to integrate this oxygen source 32 into an exhaust system, for example instead of the nitrogen dioxide source.
Furthermore, a refinement of the honeycomb body 11 in which the channel walls 17 are embodied with a basic material which acts as an electrical insulator 15 , for example ceramic or silicon carbide, is shown therein. However, in order to nevertheless motivate a movement of the soot particles to the channel walls 17 on the basis of Coulomb's forces, the channel walls 17 (which can, if appropriate, also be porous) have electrical conductors 30 , for example in the manner of a reinforcement, embedded fibers, etc. The attraction force from the channel wall 17 to the soot particles therefore becomes stronger over the length of the channels 7 , and/or this attraction force is smaller in the inlet region 8 . This axially staggered conductivity can occur on a zone-by-zone basis in this case, with the result that in each case approximately the same conductivity is provided over predefined zones 12 , but the transition can also be stepless or continuous.
FIG. 4 illustrates further details of a honeycomb body 11 as a surface precipitator, wherein the channels 7 have different channel shapes 13 . In a center 24 , that is to say in a region of the surface precipitator 6 in which there is a central flow, the channel cross section 7 is relatively large. If the channel shape 13 is considered in the direction of a radius 27 , it is to be noted that the cross section of the channels is smaller in the region of an edge 25 , that is to say a region in which there is an off-center flow. In addition, it is noted that (only) the channels 7 in the region of the center 24 have structures 14 . These structures build up a relatively large pressure drop, in particular as the flow speed of the exhaust gas increases or the volume flow of the exhaust gas becomes larger, as a result of which the exhaust gas is also conducted to a greater extent in radially outer channels. These measures contribute, in particular, to bringing about uniform loading with soot particles and uniform provision of nitrogen dioxide for the deposited soot particles.
FIG. 5 shows a further exemplary embodiment of the device 1 according to the invention. A left-hand partial region of the figure illustrates again how the exhaust gas containing soot particles 2 flows through the nitrogen dioxide source 3 in the flow direction 31 , as a result of which more nitrogen dioxide is formed. In turn, an electrical field 16 is formed below, but this time through the use of an ionization electrode 28 which serves as an ionization element 4 and a ground electrode 29 which is disposed downstream of the surface precipitator 6 and serves as a neutralization element. Consequently, the surface precipitator 6 is completely located in the electrical field 16 .
The surface precipitator 6 illustrated therein is, in particular, a conventional wall-flow filter made of ceramic or silicon carbide, the channels of which are alternately closed, as a result of which in each case flow dead ends are formed. However, the channels 7 do not, as illustrated therein, have to extend parallel to a central axis 26 of the honeycomb body. Alternately positioned stoppers or plugs 23 , which are provided for the closure, can constitute a corresponding deposition inhibitor for electrically charged soot particles or be embodied as such. The channel walls are embodied in this case in a porous and/or gas-permeable fashion, with the result that the soot particles are filtered out. If electrical conductivity is present in such a surface precipitator 6 , for example as a result of direct contact with the ground electrode 29 and with a corresponding configuration of the honeycomb body, a correspondingly selected conduction of the electrical charge should also take place. For this purpose, it is proposed that the honeycomb body be surrounded by a mat 21 which brings about a sufficient distance 22 from the housing 19 in order to avoid a voltage rollover from the surface precipitator 6 to the housing 19 . If the honeycomb body is metallic and has its own casing 20 , the same applies.
FIG. 6 is an illustration of individual method steps. In this case, in a first step, nitrogen oxides (NO x ) and/or nitrogen monoxide (NO) is converted into nitrogen dioxide (NO 2 ) through the use of the nitrogen dioxide source (and/or a corresponding catalytic coating). Furthermore, the soot particles (PM) or some of the soot particles are ionized, as a result of which they have a purely electrical charge. The electrically charged soot particles (PM + ) are then deposited uniformly on a channel wall with the aid of corresponding electrostatic attraction forces, which takes place very uniformly where possible. The soot particles (PM + /PM) which are spaced apart to a greater extent and are, if appropriate, still electrically charged or even already neutralized, are freely accessible to the generated nitrogen dioxide (NO 2 ), as a result of which simple and effective regeneration of the deposition surface and/or of the filter material is made possible. Catalysts can also be used in supportive fashion for this conversion process. After the conversion of the soot particles, the gaseous residues such as, for example, carbon dioxide (CO 2 ) and elementary nitrogen (N 2 ) are removed from the surface precipitator.
FIG. 7 is an exemplary and illustrative view of the effect of the surface precipitator 6 on the soot particle 2 . The soot particle 2 accordingly flies, for example in the flow direction 31 , through pores 33 of the surface precipitator 6 , while being electrically charged in the process. Due to the potential toward the surface precipitator 6 , this soot particle 2 does not fly linearly onward (as indicated by dashes) but instead experiences a deflection 34 and comes to bear on the surface precipitator 6 . The soot particle 2 can then be correspondingly converted there.
FIG. 8 shows details of a further embodiment variant of a surface precipitator according to the invention with a multiplicity of channels 7 which are bounded by channel walls 17 . As a result, in particular, a so-called honeycomb body 11 is formed. The honeycomb body 11 is formed from an insulating material, preferably ceramic. In order to bring about a preferred deposition of soot particles in the honeycomb body 11 , even downstream of the inlet region 8 of the honeycomb body 11 , electrical conductors 30 , which extend to different degrees in the direction of the inlet region 8 in different zones 12 of the honeycomb body, are provided in the honeycomb body which is embodied as an electrical insulator 15 .
The invention provides, in particular, uniform deposition of the soot particles and continuous regeneration of the surface precipitator.
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A method for converting soot particles of an exhaust gas includes providing at least nitrogen dioxide or oxygen in the exhaust gas, ionizing soot particles with an electric field, depositing electrically charged soot particles on inner channel walls of at least one surface precipitator, and bringing at least nitrogen dioxide or oxygen into contact with the deposited soot particles on the inner channel walls of the at least one surface precipitator. A device for carrying out the method includes at least one surface precipitator having a plurality of channels through which the exhaust gas can flow and extending between an inlet region and an outlet region, and at least one deposit inhibitor for electrically charged soot particles provided in at least part of the inlet region, especially allowing the soot particles to be evenly deposited and the surface precipitator to be continuously regenerated.
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BACKGROUND OF THE INVENTION
This invention relates to the degassing of a pulp slurry following oxygen bleaching. Bleaching is employed to delignify and whiten brown stock from a wood digestion process.
In recent years oxygen has often been used as the bleaching agent, in place of the chlorine that was formerly the principal chemical used. The use of oxygen reduces the effluent from the bleaching step. Bleaching processes employing oxygen are disclosed in U.S. Pat. Nos. 3,814,664, 3,832,276, 3,963,561, 3,964,962, and 4,022,654, all of which are hereby incorporated by reference. None of these, however, mentions the problems that can occur in the subsequent processing of an aqueous wood fiber slurry that has been oxygen-bleached. Degassing of residual oxygen could occur at an inopportune moment in such subsequent processing and cause the wood fibers to rise to the surface of the slurry, thereby forming a mat of such fibers, which hinders further processing.
Methods of removing gases from pulp slurries are suggested in U.S. Pat. Nos. 3,432,036 and 3,807,142. In the former, a number of hydrocyclones and a large vacuum tank are needed, which require a substantial capital outlay and a large amount of energy to maintain the vacuum. In the latter patent, a cyclone-type separator is used, but in actual operation, this type of separator has been found ineffective in removing residual oxygen.
SUMMARY OF THE INVENTION
Briefly, the present invention requires the use of an impeller that imparts a substantially radial flow to the pulp slurry. It is believed that the shear and high rate of energy dissipation provided by such a radial-flow impeller overcomes the interfacial forces between the fine bubbles of residual oxygen and the fibers in the slurry and allows the bubbles to agglomerate and degas.
The successful use of such an impeller to separate residual oxygen is surprising in view of the teaching in U.S. Pat. No. 3,832,276 (column 3, lines 21 to 45) that agitation can be used to disperse oxygen in a pulp slurry. Use of this invention prevents unexpected and inopportune degassing and the associated problems, and reduces the amount of defoamer required in subsequent processing.
BRIEF DESCRIPTION OF THE DRAWINGS
In order to more fully explain the present invention, the following drawings are provided in which:
FIG. 1 is a side sectional view of a degassing vessel employing one embodiment of the present invention;
FIGS. 2 through 5 show several radial-flow impellers; and
FIG. 6 is a block flow diagram showing the use of the present invention in an oxygen-bleaching sequence.
These drawings are provided for illustrative purposes and should not be construed to limit the scope of the invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention employs a radial-flow impeller to remove a significant portion of the residual oxygen from a wood fiber slurry following an oxygen-bleaching step. As used herein, a "radial-flow impeller" is one that imparts a "substantially radial flow" to the fluid. An impeller imparts a "substantially radial flow" when at least 50%, and, preferably, 80%, of the total flow leaving the tip(s) of the impeller is in the plane of the impeller's rotation. (See, for example, "Suspension of Solids" by J. E. Lyons in "Mixing," Vol. II (edited by V. W. Uhl and J. B. Gray), Academic Press, 1967, hereby incorporated by reference, for further discussion of radial-flow impellers.)
"Significant portion" of the residual oxygen means at least 50% of such oxygen. Preferably, at least 70% of the residual oxygen is removed through use of the present invention.
"Residual oxygen" is that which remains in the slurry after gross separation of oxygen and slurry following the oxygen-bleaching step. Such gross separation may be accomplished by conventional means in a section of the bleaching vessel, in a separate vapor-liquid separator, or in a section of a vessel employing the present invention. Preferably, at least some of the gross separation occurs in the top section of a vessel having a radial-flow impeller, in accordance with the present invention.
The amount of residual oxygen in the untreated slurry may be great as 350 ppm by weight of the slurry, usually up to 150 ppm, but preferably not greater than 100 ppm. The residual oxygen may be dissolved in the slurry, or entrained therein as fine gas bubbles, or both. Usually, 50 to 60% of the residual oxygen will be in the form of entrained bubbles, but it may be more or less, depending on the particular equipment configuration and operating conditions.
The consistency (fiber weight concentration) of the slurry is broadly from 0.01 to 10% and generally from 0.5 to 3.0% and the viscosity usually from 1 to 100 centipoises. Both hardwood and softwood pulps may be degassed using the present invention. Typical hardwoods are aspen, beech, birch, and maple; typical softwoods are spruce, pine, and fir. Generally, softwood pulps have longer fibers than hardwood pulps (longer fibers entrain greater volumes of residual oxygen).
In practicing the present invention, the slurry is fed to a vessel following an oxygen-bleaching step. The vessel may be of any shape or size but should provide a residence time for the slurry of from one second to thirty minutes, usually from 15 seconds to ten minutes, and, preferably, from thirty seconds to five minutes.
The radial-flow impeller may be of any shape and more than one may be used. Preferably, an "axial-flow impeller," which imparts a substantially axial flow to the slurry, is employed in the same vessel. Its function is to maintain top to bottom circulation of the slurry and prevent formation of a fiber mat on top of the liquid. An impeller imparts "substantially axial flow" when at least 50% of the flow leaving the tip(s) of the impeller is perpendicular to the plane of the impeller's rotation.
The tank, impeller(s), and other equipment in contact with the slurry may be of any materials of construction that are suitable for use under the prevailing operating conditions, particularly the slurry pH and temperature. Generally, mild steel or 304 stainless steel is used.
The liquid height (H) in the vessel should be from 50% to 200% of the vessel diameter (T), and, preferably, from 75 to 150% of T. (By "diameter" the equivalent diameter is meant. Formulas for calculating the equivalent diameter of vessels having non-circular cross sections are well-known.)
If an axial-flow impeller is used, in addition to the radial-flow impeller, it should be located above the radial-flow impeller and at a depth of from 10 to 50% of H and, preferably, at a depth of from 25 to 40% of H. (The depth is measured down from the average liquid height during operation.) In this case the radial-flow impeller (the lower impeller) would be located at a depth of from 50% of H down to a depth equal to H minus D (where D equals the diameter of the impeller) and, preferably, at a depth of from 60% of H down to H minus D. (For example, if H were ten feet and D were 3 feet, the radial-flow impeller would preferably be at a depth of from 6 feet to 7 feet.) The diameters of the impellers should range from 10% of T to 50% of T and, preferably, from 20% to 40% of T.
If only a radial-flow impeller is used, it should be located at a depth of from 20% of H down to H minus D and, preferably, from 40% of H down to H minus D. Its diameter should be from 10% to 75% of T and, preferably, from 20% to 50% of T.
The one or more impellers employed are usually driven by the same rotating means, although they need not be. The rotating means is usually an electric motor. Horsepower requirements vary depending on the slurry consistency, wood species, and number, size, and shape of the impellers, and range from 0.1 to 50 horsepower (U.S.) per thousand gallons (U.S.) of slurry. Usually from 0.25 to 10 horsepower per thousand gallons is used and, preferably, from 0.5 to 5 horsepower per thousand gallons.
Turning now to the drawings, FIG. 1 is a side cut-away view of degassing vessel 10 employing the present invention. Pulp slurry from an oxygen-bleaching vessel enters at nozzle 12. Nozzle 12 is tangentially positioned on the vessel to create a swirling motion in the slurry, thereby aiding the gross separation of oxygen from the slurry inside the vessel. The gas exits at nozzle 14. The fiber slurry, containing the residual oxygen, drops into the agitation portion 16 of the vessel, where residual gas is removed. The degassed slurry exits at nozzle 18.
Radial-flow impeller 20 and axial-flow impeller 22 are mounted on vertical shaft 24, which is attached to rotating means not shown. Four vertical baffles 26 (only two of which are shown) are symmetrically located in the vessel and prevent vortex formation, which represents a loss of energy (energy for vortex formation does not cause shear and the resultant degassing).
FIGS. 2, 3, 4, and 5 are perspective views of four radial-flow impellers. In all cases blades or paddles 28 are mounted on shaft 30.
FIG. 6 is a schematic flow diagram of oxygen-bleaching-oxygen-removal steps. Unbleached pulp 32 is fed by screw feeder 34 to equipment represented by box 36, where the pulp is mixed with recycle filtrate 48 and oxygen and caustic 50, and bleached. Effluent 38 is combined with slip-stream 40 of recycle filtrate, the flow is throttled to reduce pressure, and the mixture is fed to gas separation vessel 10, shown in detail in FIG. 1. Degassing occurs in vessel 10, as described above. Oxygen exits at overhead 42 and degassed pulp slurry 44 exits at the bottom. Pressure washer 46 separates the pulp from the filtrate. Most of the water is recycled (streams 40 and 48), the remainder (stream 52) being purged.
In order to further illustrate the present invention, the following examples are provided. These, however, should not be construed to limit the claims.
EXAMPLE I
A hardwood pulp slurry having a consistency of approximately 1.3% and containing approximately 100 ppm by weight oxygen, a portion of it in the form of bubbles (average diameter of 100 to 200 microns), was fed to a twenty-four inch diameter tank. The slurry was agitated with an eight-inch diameter, flat blade, disc turbine impeller mounted on a coaxial shaft rotated at about 200 rpm by a one-third horsepower air-driven motor. The flow induced by the impeller was at least 90% radial. Residence time in the tank was 1.5 minutes, and the average liquid height was 6 inches above the impeller (total liquid height of 22 inches). Four two-inch wide vertical baffles were symmetrically mounted in the tank. Samples of the fiber slurry entering and exiting the tank were taken.
To determine degassing efficiency, a plunger formed by covering a perforated disc with a wire screen filter cloth was moved down through the slurry sample using constant pressure. A pulp mat formed below the plunger surface, and filtrate was forced up through the pulp mat and filter cloth. Filtration time was assumed to be directly related to the quantity of air in the test sample.
The sample of untreated slurry entering the tank required forty seconds to filter. For calculational purposes this time was taken as equivalent to 0% degassing. When the resulting pulp mat was reslurried in the filtrate and stirred to remove trapped gas to provide a sample that was 100% degassed, refiltration required twenty seconds. The discharge sample, which had been processed in accordance with the present invention, required only twenty-five seconds to filter. Measured against the 0% and 100% end-points, twenty-five seconds is equivalent to a 75% degassing efficiency.
COMPARATIVE EXAMPLE
Example I was repeated, except that an 8.7 inch diameter propeller was used instead of the radial-flow impeller. The flow induced was at least 90% axial, that is, less than 10% radial. A sample of test tank effluent required slightly over thirty-four seconds to filter, indicating a degassing efficiency of only 28%. Thus, under identical conditions, the use of a radial-flow impeller results in substantially greater degassing of the pulp slurry (75% efficiency with the radial-flow impeller vs. only 28% with the propeller).
EXAMPLE II
Example I was repeated with a softwood pulp slurry having a consistency of 1.3%. The 100% and 0% degassing times for this system were determined as in Example I. A sample of slurry treated in the vessel filtered at a rate indicating that a 71% degassing efficiency was achieved through use of the present invention.
Variations and modifications of the present invention will be apparent to those skilled in the art. The claims are intended to cover all such modifications and variations as fall within the true spirit and scope of this invention.
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A method for removing residual oxygen from an aqueous slurry of pulp that has been oxygen-bleached is disclosed. The slurry, usually containing no more than 3 weight percent fiber, is agitated by a radial-flow impeller, which imparts a substantially radial flow to the slurry. If the residual oxygen is not removed, it may degas at an inopportune moment during later processing (for example, washing) and carry some of the wood fibers to the surface of the slurry, thereby forming a foamy mat, which hinders further processing.
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BACKGROUND OF THE INVENTION
This invention relates to compositions particularly suited for the formation of refractory monoliths, and in particular to such a composition for forming a ramming mix for use as a cooler plate packing material in blast furnaces.
Monolithic or monolith forming refractories are special mixes or blends of dry granular or stiffly plastic refractory materials, with which virtually joint free linings are formed. They embrace a wide range of mineral compositions and vary greatly in their physical and chemical properties. In various types of furnaces, monolithic refractories are used to advantage over brick construction. The use of monolithic refractories enables the installation to be made in a relatively short period of time whereby any delays resulting from a required manufacture of special brick shapes may be avoided. Further, the use of monolithic refractories frequently eliminate difficult brick laying tasks. The use of monolithic refractories is of particularly importance in the maintenance of furnaces. Substantial repairs may be made with a minimum loss of time, and in some instances, even during continued operation of the furnace.
A ramming mix is one type of composition typically used to create a monolith. One application of a ramming mix involves the use thereof as a cooler plate packing material in blast furnaces. Requirements for the ramming mix to satisfy the needs of this particular application include relatively high thermal conductivity, a dried cold crushing strength of at least 1000 psi, reheat stability at 1000° F., ramming mix or platic consistency, a relatively high degree of water insolubility, and a curing temperature not exceeding 250° F. Although some ramming mixes satisfy one or more of the required properties, the ramming mix of the present invention satisfies all of the properties. Further, the present ramming mix is sold as a single component and has a four-month shelf life.
SUMMARY OF THE INVENTION
Accordingly, it is an object of this invention to provide a ramming mix particularly suitable for use as a cooler plate packing material in blast furnaces and having the following properties:
(1) relatively high thermal conductivity;
(2) dried cold crushing strength of at least 1000 psi;
(3) reheat stability at 1000° F. (linear shrinkage not exceeding 1.5%);
(4) ramming mix or plastic consistency;
(5) a relatively high degree of water insolubility; and
(6) a curing temperature not exceeding 250° F.
The above objective is attained in a monolithic refractory batch composition comprising, by weight, 50-75% relatively large grain flake graphite; 5-30% relatively micronized flake graphite; approximately 20% ball clay, said batch further containing, based on its total weight, 10-25% liquid phenolic resin in combination with an alcoholic solvent, and 0.5-2% resin curing agent.
DESCRIPTION OF THE PREFERRED EMBODIMENT
A commercial need was identified for a refractory to be used as a packing material for a blast furnace shell and cooler plate, having the following properties:
(1) thermal conductivity of 75 Btu/ft 2 --Hr.°F/in. at 1500° F. (in the "fast" direction);
(2) dried cold crushing strength of at least 1000 psi;
(3) reheat stability at 1000° F.; and
(4) ramming mix or plastic consistency.
As used herein, the term "fast" direction is the measurement of conductivity in a direction taken perpendicular to that in which the material is pressed in applying the same, while the "slow" direction corresponds to measurement of the thermal conductivity in the direction taken parallel to that in which the material is pressed or rammed.
Initially, it is presupposed that a monolith refractory based on silicon carbide and/or flake graphite could be produced to meet the above requirements. Initial work included evaluation of a series of bench scale mixes consisting of silicon carbide, graphite and clay. This was done to determine the effect, if any, that the addition or elimination of graphite to a commercial ramming mix would have on the Mix's plastic consistency. Referring to Tables I and II, poor plastic properties and reduced crushing strength in Mixes E, E-1 and F corresponded to the inclusion of flake graphite in amounts exceeding 12.5%. Mix A had the highest cold crushing strength (900 psi) after drying. The thermal conductivity of a ramming mix containing 10% flake graphite, was 45.8 Btu/ft 2 --Hr.°/in. at 1500° F. in the "fast" direction. Consequently, it was assumed that the thermal conductivity of Mixes D through G would not meet the desired goal of at least 75 Btu/ft 2 --Hr.°F./in.
TABLE I__________________________________________________________________________ Mix Designation: A A-1 A-2 B B-1 C C-1 D__________________________________________________________________________Mix:Silicon Carbide -8/+16 mesh 40%-16/+30 mesh 5%-30/+50 mesh 10%-50/+100 mesh 5%Silicon Carbide DCF 30 30 35 25 25 20 20 151631 Flake Graphite -- -- -- -- -- -- -- 10Mexaloy Graphite -- -- -- -- -- -- -- --M & D Ball Clay 10 -- -- 15 -- 20 -- 15Jackson Ball Clay -- 10 -- -- 15 -- 20 --SPV Volclay -- -- 5 -- -- -- -- --Plus Additions:Silicanit 2%Water (for pressing) 7.3 6.8 8.8 7.7 7.8 8.1 8.0 8.6Water (for storage) 10.3 7.9 9.8 12.7 10.8 9.6 9.0 10.6Bulk Density, pcf (Av. 3)After Heating 18 Hrs. at 250° F.: 156 158 150 155 155 154 152 147After Heating 5 Hrs. at 2000° F.:* 156 156 149 152 152 150 148 144Apparent Porosity, % (Av. 3) 20.1 19.4 23.0 20.9 20.7 21.6 22.7 22.6After Heating 5 Hrs. at 2000° F.:*Reheat 2000° F. (Av. 3)*Linear Change: -0.3. -0.2 +0.2 ±0.2 ±0.3 ±0.3 -0.3 -0.3Volume Change: -0.8 -0.2 -0.2 -0.4 -0.3 -0.3 -0.7 -0.8Cold Crushing Strength, psi 900 890 740 730 740 640 600 630After Heating 18 Hrs. at 250° F.Workability (Storage Data) 40 40 35 37 43 37 39 3314# wt. as Made for PressingTempered for Storage 43 50 50 50 45 43 44 46 (5# wt.) (5# wt.) (5# wt.)After One Week 29 26 32 56 31 31 30 33 (5# wt.) (5# wt.)After One Month 42 21 24 55 50 24 23 33After Two Months 33 22 25 49 39 21 19 33After Three Months 37 16 24 44 35 18 15 38__________________________________________________________________________ *Reducing conditions.
TABLE II__________________________________________________________________________ Mix Designation: D-1 D-2 E E-1 E-2 F G__________________________________________________________________________Silicon Carbide -8/+16 mesh 40%-16/+30 mesh 5%-30/+50 mesh 10%-50/+100 mesh 5%Silicon Carbide DCF 15 20 12.5 12.5 15 15 151631 Flake Graphite 10 -- 12.5 12.5 -- 15 --Mexaloy Graphite -- 10 -- -- 15 -- 15M & D Ball Clay -- -- 15 -- -- 10 10Jackson Ball Clay 15 -- -- 15 -- -- --SPV Volclay -- 10 -- -- 10 -- --Plus Additions:Silicanit 12%Carboxymethyl Cellulose -- -- -- -- -- 0.75 0.75Water (for pressing) 8.5 9.7 8.5 8.6 10.0 12.6 13.5Water (for storage) 10.0 11.2 10.0 10.1 11.1 14.6 15.5Bulk Density, pcf (Av. 3)After Heating 18 Hrs. at 250° F.: 146 144 145 144 140 131 125After Heating 5 Hrs. at 2000° F.:* 143 142 142 141 137 129 124Apparent Porosity, % (Av. 3) 22.8 23.8 23.2 23.1 25.1 30.1 32.1After Heating 5 Hrs. at 2000° F.:*Reheat 2000° F. (Av. 3)*Linear Change: -0.2 -0.4 ±0.2 -0.2 -0.2 -0.1 ±0.4Volume Change: -0.5 -0.5 -0.4 -0.7 -0.4 -0.5 -0.4Cold Crushing Strength, psi 600 750 540 510 600 560 280After Heating 18 Hrs. at 250° F.Workability (Storage Data) 35 30 32 39 32 35 3514 # wt. as Made for PressingTempered for Storage 50 43 43 50 46 46 46After One Week 43 36 26 36 38 36 38After One Month 34 33 29 39 38 52 50After Two Months 31 32 28 34 35 60+ 60+After Three Months 30 32 28 35 37 -- --__________________________________________________________________________ *Reducing conditions.
Referring to Table III, there is shown the results of the testing of a second series of mixes. The second series of mixes, labeled H through L, were made from a batch including silicon carbide, clay and increased amounts of either Mexaloy, micronized amorphous, or micronized flake graphite. These mixes also contained a powdered pitch addition to improve crushing strength after drying. Mixes I, K and L included micronized flake graphite. These mixes required additional quantities of water for forming the monolith and consequently, the density of the monolith was significantly reduced. The thermal conductivity of Mix H and J was determined to be 30 Btu/ft 2 --Hr.°F./in. in the "slow" direction. None of these mixes proved commercially acceptable.
TABLE III__________________________________________________________________________ Mix Designation: H I J K L__________________________________________________________________________Mix:Silicon Caribde -8/+16 mesh 40% 40% 40% 40% 28%-16/+30 mesh 5 5 10 5 10-30/+50 mesh 10 10 5 10 4-50/+100 mesh -- 5 -- 5 --Silicon Carbide, DCF -- 5 -- -- --Ashbury Micronized Graphite #505 30 -- -- -- 30Ashbury Micronized Graphite #FG -- 20 -- 27 10Mexaloy Graphite -- -- 40 -- --Powdered Pitch 10 10 10 10 8M & D Ball Clay 5 5 5 --SPV Volclay -- -- -- 3 --Plus Additions:Silicanit 2%Water (for pressing) 10 12 12 14 14Water (for storage) 13 21 16 23 23Bulk Density, pcf (Av. 3) As Made: 134 127 134 120 124After Heating 18 Hrs. at 250° F.: 124 116 120 107 110After Heating 5 Hrs. at 2000° F.:* 118 112 114 -- --Method of Forming: 21/8" × 2 1/2" Cylinders Pressed at 1000 psiCold Crusing Strength, psi (Av. 3)After Heating 18 Hrs. at 250° F. 930 650 950 370 690After heating 18 Hrs. at 400° F. 1380 1190 1120 670 1090Workability (Storage Data) 29 35 42 25 295# wt. as Made:After One Week 25 30 41 24 23After One Month 49 62 27 19 20 (14# wt.)After Two Months 40 20 60 17 50 (14# wt.) (14# wt.) (14# wt.)__________________________________________________________________________ *Reducing conditions.
Additional mixes were prepared (M, N, O, P and R) as indicated in Table IV. These mixes were prepared as resin bonded, flake graphite plastics. These mixes contained 80 to 100% flake graphite (Asbury 3166A and Asbury micronized FG) with additions of alumina (M) or ball clay (N, O and P). The resin required to bring these mixes to a plastic consistency ranged from 35 to 50%. These mixes were pressable, but laminations and severe cracking occurred after drying of the pressed specimen.
TABLE IV______________________________________ Mix Designation: M N O P R______________________________________Mix:Asbury 3166A 50% 55% 60% 55% 60%GraphiteAsbury Micronized 30 30 30 30 410Flake Graphite, FGM & D Ball Clay -- 15 10 15 --A-17 Alumina 20 -- -- -- --Plus Additions:ML-53 Resin 35 35 -- -- --RL-2302 Resin -- -- -- 50 50RM 441 Resin -- -- 35 -- --Stadex 4.0 4.0 4.0 4.0 4.0Darvon C 0.10 0.10 0.10 0.10 0.10Method of Forming: Six inch bars were pressed at 1000 psiObservation: None of these mixes had good compaction properties and laminations resulted after pressing.Bulk Density, pcf 100 93 102 100 93After Drying 18Hrs. at 500° F.______________________________________
Additional mixes (X, Y and Z) were prepared as ramming mixes having reduced binder additions. These mixes are described in detail in Table V. Mixes Y and Z (100% flake graphite) contained reduced amounts of liquid resin, while Mix X contained water. Mix Y, having the 20% addition of ball clay, provided a mix with the best rammability. The thermal conductivity of Mix Y in the "slow" direction was 55.0 Btu/ft 2 --Hr.°F./in. at 1500° F. In contrast, Mix X had a thermal conductivity value of 35.0 Btu/Ft 2 --Hr.°F./in. at 1500° F. in the "slow" direction. The thermal conductivity for Mix Y was also determined in the "fast" direction. This was done by continuously ramming a large block of material and then cutting nine-inch straights from the block. The thermal conductivity was measured perpendicular to the direction of ramming. The thermal conductivity value for Mix Y in the "fast" direction was 82.6 Btu/Ft. 2 --Hr.°F./in. at 1500° F. This represents a difference of 27.5 Btu/Ft. 2 --Hr.°F./in. over the thermal conductivity value of the same mix in the "slow" direction.
TABLE V______________________________________ Mix Designation: X Y Z______________________________________Mix:Asbury 3166A 40% 50% 50%Flake GraphiteAsbury Micronized 30 30 50Flake Graphite FGM & D Ball Clay 20 20 --Powdered Pitch 10 -- --Plus Additions:RM441 Liquid Resin -- 21 30Water 18 -- --Stadex 4 4 4Darvon C 0.10 0.10 0.10Bulk Density, pcf(Av. 3) As Made:After Heating 18 Hrs. 110 117 102at 500° F.After Heating 5 Hrs. 90 108 86at 1500° F.*Forming Pressure, psi: 1000 2000 1000Appearance After Some lamina- Good com- SevereForming: tions oc- paction laminations curred in properties occurred in shape pressed 9" straightsCold Crushing Strength 650 1310 440psi (Av. 3) After Heat-ing 18 Hrs. at 500° F.:Linear Change, %After Heating 18 Hrs. -0.8 -0.4 --at 500° F.After Heating 5 Hrs. -- -1.2 --at 1500° F.:*Observed StorageBehavior:After 1 week Good Good --After 1 month Good Good --After 2 months -- Good --Bulk Density, pcf (Av. 3) -- 103 --After RammingContinuously:After Ramming and -- 93 --Heating 18 Hrs.at 500° F.Appearance afterRamming And Drying at500° F. (Mix Y only) Cut samples from large rammed blocks were essentially lamination free. The brick were submitted for Thermal Conductivity Determination in the "Fast Direction".______________________________________ *Reducing conditions.
After heating at 1500° F., Mix Y had a linear change of -1.2% and a volume change of -3.8%. Table VI illustrates a comparison of the thermal conductivity between mixes H, J, X and Y.
Based upon the test work, it was determined that Mix Y would represent the best candidate for a graphite based high conductivity ramming mix. A sample of the mix was tested, with the evaluation of the test indicating that the mix was commercially satisfactory in all respects, except that it had a relatively high degree of water solubility and required a higher than desired resin curing temperature of 500° F. It was decided to conduct additional testing to develop a high thermal conductivity mix having a high degree of water insolubility and a curing temperature of about 250° F. Mix Y was used as the starting basis for the additional test work.
TABLE VI__________________________________________________________________________Thermal Conductivity on Selected Mixes*Mix Designation:H J X Y YSlow Direction Slow Direction Slow Direction Slow Direction Fast DirectionMean Thermal Mean Thermal Mean Thermal Mean Thermal Mean ThermalTempera-Conduc- Tempera- Conduc- Tempera- Conduc- Tempera- Conduc- Tempera- Conduc-ture (°F.)tivity ture (°F.) tivity ture (°F.) tivity ture (°F.) tivity ture (°F.) tivity__________________________________________________________________________ 323 23.73 323 25.40 311 24.59 306 50.16 311 84.891065 26.03 1050 27.51 1146 26.74 1154 46.0 1165 82.581805 33.98 1792 33.30 1781 38.94 1838 56.66 689 85.941455 31.56 1445 32.07 1426 36.59 1471 56.44 225 88.961089 28.86 1089 30.07 1044 35.05 1088 55.04 720 26.88 717 27.96 660 36.00 699 54.19 243 24.48 249 25.96 224 34.94 236 56.23__________________________________________________________________________ *Argon Atmosphere Btu/Ft.sup.2 -Hr. °F./in.
Table VII illustrates the test work conducted on additional mixes AA-EE. A resorcinol type resin and various powdered phenolic resins were added to the mixes in an attempt to achieve the best water insoluble cure. Water solubility was measured by determining the weight loss of cured samples that were exposed to boiling water for six hours. Initial tests indicated that Mix EE, which contained RL-2302 resin manufactured by Borden Chemical Company (RL-2302 resin was formerly sold as ML-25R resin), showed the best water insolubility (lowest weight loss). RL-2302 resin is a phenolic resin which can be thermoset by the addition of a curing agent. As curing agent either hexamethylenetetramine ("hexa") or stadex were used. The curing agents caused the resin to thermoset at relatively low temperatures at about 250° F. An alcoholic solvent such as ethylene glycol was also used in some instances.
TABLE VII______________________________________ Mix Designation: AA BB CC DD EE______________________________________Mix:Asbury 3166A 50 50 50 50 50Flake GraphiteAsbury FG110 30 30 30 30 30Micronized Flake GraphiteM & D Ball Clay 20 20 20 20 20Plus Additions:RM441 Resin (65% solids) 25 -- -- -- --RL-2304 Resin -- 22 -- -- --SD 5132 Powdered Resin -- -- 10 -- --SD 5144 Powdered Resin -- -- -- 15 --RL-2302 Resin -- -- -- -- 22Ethylene Glycol -- 8 -- -- 12Water -- -- 20 20 --Hexa 1.6 1.4 1.0 -- 1.8Stadex -- -- -- 4.0 --Method of Forming: 1.5" × 1.5" Dia Cylinders Were Pressed at 1000 psiBulk Density, pcf After 117 116 107 106 115Pressing at 1000 psi:After Drying 18 109 108 -- -- 108Hrs. at 180° F.After Drying 12 -- 107 -- -- 108Hrs. at 250° F.*Cold Crushing Strength psiAfter Drying18 Hrs. at 180° F.: -- 1190 -- -- 1050After Drying18 Hrs. at 250° F.: -- 1420 -- -- 1370Water Solubility Test, %Weight LossAfter Drying at 180° F. and 6.3 4.2 Dissolved 2.4Boiling 6 Hrs.After Drying at 250° F. and 4.5 2.8 2.5 3.5 2.3Boiling 6 Hrs.______________________________________
Additional tests were conducted as illustrated in Table VIII with newly prepared mixes FF-JJ. These mixes were all made with RL-2302 resin. In these mixes, the amount of Asbury FG micronized graphite was varied in the mix to determine the effect on rammability, pore size, and ultimately, thermal conductivity. A Mercury porosimetry test, conducted on Mixes GG, II and JJ, determined that Mix II had the smallest average pore diameter (5 microns). The thermal conductivity of Mix II was determined perpendicular to the direction of ramming (high thermal conductivity value or "fast" direction) and parallel to the direction of ramming (low thermal conductivity value or "slow" direction).
TABLE VIII______________________________________ Mix Designation: FF GG HH II JJ______________________________________Mix:Asbury 3166A 55 60 65 70 80Flake GraphiteAsbury FG110 25 20 15 10 --Micronized FlakeGraphiteM & D Ball Clay 20 20 20 20 20Plus Additions:RL-2302 Resin 22 22 18 16 14Ethylene Glycol 7 2.5 3 3 2.5Hexa 1.8 1.8 1.8 1.5 1.2Method of Forming: 1.5" × 1.5" Dia Cylinders Were Pressed at 100 psiBulk Density, pcfAfter Ramming and -- -- -- 112 98Drying at 250° F.After Pressing at 112 114 116 117 121100 psi:After Drying 18 108 111 112 113 116Hrs. at 180° F.After Drying 18 108 110 112 112 111Hrs. at 250° F.*After Heating -- -- -- 109 --5 Hrs. at 1000° F.Apparent Porosity, % -- 15.6 15.6 17.1 17.0After Ramming andDrying 18 Hrs.at 250° F.Average Pore Dia., -- 8.5 -- 5.0 6.3Microns (MercuryPorosimetry)After Ramming andDrying 18 Hrs. at250° F.Cold CrushingStrength psiAfter Drying 1070 1850 1840 1740 1930at 180° F.After Drying 1550 1920 2160 1800 2720250° F.Linear Change, %After Drying at -- -0.7 -0.2 -0.3 -0.6250° F.After Heating -- -- -- -1.0 --5 Hrs. at 1000° F.,ReducingVolume Change, %After Drying at -- -0.7 -0.2 -0.2 -0.3250° F.After Heating 5 Hrs. -- -- -- -3.0 --at 1000° F., ReducingWater Solubility% Weight LossAfter Drying at 2.1 3.8 4.8 4.9 4.6180° F., andBoiling 6 Hrs.After Drying at 1.3 0.7 0.7 0.6 0.4250° F., andBoiling 6 Hrs.______________________________________
Table IX illustrates the comparative testing conducted on these mixes.
Mix II had the best ramming and compaction properties compared to other mixes. Its degree of water insolubility after curing at 180° F. and 250° F. was improved compared to previously developed mixes. The thermal conductivity of this material was 168.3 Btu/Ft 2 --Hr.°F./in. compared to 84.9 Btu/Ft 2 --Hr.°F./in. for previously developed Mix Y ("fast" direction). Mix JJ had a thermal conductivity of 69.4 Btu/Ft 2 --Hr.°F./in. Mix II had improved thermal conductivity compared to mixes Y and JJ due to better ramming properties, increased rammed density, and smaller average pore size. Mix II therefore achieved the best overall commercial characteristics as a ramming mix for packing around blast furnace cooler plates. Mix II has high conductivity, high cold crushing strength (in excess of 1500 psi after heating at 250° F.), a high degree of water insolubility and good ramming properties.
TABLE IX__________________________________________________________________________Thermal Conductivity (Argon Atmosphere)Mix Designation:Y* Y* II** II** JJ**Fast Direction Slow Direction Fast Direction Slow Direction Fast DirectionMean Thermal Mean Thermal Mean Thermal Mean Thermal Mean ThermalTempera-Conduc- Tempera- Conduc- Tempera- Conduc- Tempera- Conduc- Tempera- Conduc-ture (°F.)tivity ture (°F.) tivity ture (°F.) tivity ture (°F.) tivity ture (°F.) tivity__________________________________________________________________________311 84.9 306 50.2 312 168.3 309 54.2 310 69.41165 82.6 1154 46.0 1201 139.6 1180 50.5 1226 65.5689 85.9 699 54.2 709 143.0 709 53.7 733 69.3225 89.0 236 56.2 258 152.0 244 55.6 242 76.7__________________________________________________________________________ *Test Samples were cured at 500° F. **Test Samples were coked at 1000° F. ***Test Samples were cured at 250° F.
Table X illustrates the Taylor Standard Series screen analysis of Mix II.
TABLE X______________________________________Mix Designation: II______________________________________Screen Analysis% Held on8 mesh10 mesh14 --20 --28 2 235 848 2865 22 58100 10150 -- 10200 2270 --325 -- 2Minus 325 mesh 28 28______________________________________
While the preferred embodiment of the present invention has been described and illustrated, the invention should not be limited thereto, but may be otherwise embodied within the scope of the following claims.
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A monolithic refractory composition having relatively high thermal conductivity and a relatively high degree of water insolubility consisting essentially of, by weight, 50-75% coarse grain flake graphite; 5-30% fine grain flake graphite; and the remainder crude clay; and the addition based upon the total weight of said mix of 10-25% liquid phenolic resin in combination with an alcoholic solvent, and a resin curing agent.
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BACKGROUND OF THE INVENTION
[0001] The invention relates generally to filter elements and, more specifically, to a novel, non-obvious filter element having a magnetic array for assisting in the removal of ferrous particles from a fluid flow.
[0002] In the process of making hydraulic components, such as gears, pumps, motors, valves and cylinders, ferrous metal particles are produced that contaminate the fluids used in the manufacturing process. These ferrous particles can result in decreased life of the fluid system. Current ISO standards require the removal of particles down to the level of 4 microns. Filters capable of removing particulate contaminants down to 4 microns are expensive and often must be combined into a bank of filter elements in parallel or series to handle the amount of fluid flow that must be processed. When filtering oil used in manufacturing processes, magnetic are known for use in removing ferrous contaminants, including even sub-micron sized contaminants, from the fluid flow. Typically, these magnetic filters are a one-time expense and can be placed upstream of traditional filter media to help extend the life of the standard filter, thus reducing overall costs of operation.
[0003] In operational systems, such as engines, transmissions, and mobile construction equipment hydraulic systems, iron based contaminates will be generated in the normal wear and tear of operation, Typically, these metal contamination particles are relatively hard and can induce wear in a system. Many times these systems are operated outside in cold environments and putting in a fine filter medium to trap effectively these fine particles can have a negative impact on performance due to the increased pressures from the high viscosity of low temperature oil. Therefore, the filters used tend to be higher in absolute micron rating which allows larger contaminants to flow through the system and ultimately leads to lower component life. Magnetic filters can dramatically improve the filtration of the oil to much finer filtering without the cold weather bypass restrictions of a standard filter.
SUMMARY OF THE INVENTION
[0004] The present invention is a filter element having a magnetic array and which is designed to trap the most abrasive contaminates, which are ferrous based, from a fluid system with a low service cost. The filter element has an outer cylindrical can and a coaxial inner liner with a plurality of axial magnets extending substantially the length of the liner interposed in a cylindrical array either between the liner and the outer can or around the outer can. In contrast to known filters, the magnets are thus placed inside the metal can and so are more effective at trapping ferrous contaminants. The ferrous based contaminates are attracted to the liner by the magnets and held. When it is time to service the magnetic filter, the liner is removed to either be washed and reused, or simply thrown away if the liner can be made cheaply enough. The design should be modular in nature such that multiple filters can be stacked in parallel circuits to slow the flow down to maximize the contaminant removal. In some installations, the parallel system is placed in front of the standard filter to act as both an absolute filter as well as an indicator when to service the system. Other versions could be made to target specific markets such as diesel engines used in transportation and logistics, as well as other markets.
[0005] In a preferred embodiment, a spiral baffle is placed inside the filter to increase the flow path of fluid through the filter, thereby also increasing residence time in the filter, and to direct the higher density contaminants toward the liner at outer wall of the filter where the magnetic filed is the strongest and where trapping of the ferrous contaminants is most effective. An advantage of the spiral flow path is that it has a constant cross-sectional area which eliminates restrictions in the fluid flow path. Alternatively, an insert which induces a vortical flow of the fluid along the axis of the filter can be used.
[0006] In another preferred embodiment, the magnets are arranged in pairs of alternating polarity. Alternatively, they may be arranged in a spaced relationship with adjacent magnets having alternating polarity.
[0007] In another preferred embodiment, multiple filter elements of the present invention are arranged in series to increase the holding capacity of trapped contaminants. Alternatively, multiple magnetic filter elements of the present invention may be arranged in parallel arrays that will slow down the fluid flow through each element, thereby increasing the residence time in each element to allow more time for trapping of the ferrous contaminants. The stacked and parallel arrays can be combined with a filter having standard filtering medium to catch non-ferrous contaminants for absolute filtration capability. The standard filter can then use a pressure differential detection across the filer medium to indicate when to check the magnetic array filter elements for cleaning.
[0008] In another embodiment, an air purge can be used to push fluid out of the array to facilitate changing of the filter elements.
[0009] In an alternative embodiment, the stacked arrays of the standard filter element and the magnetic array filter elements of the present invention may be assembled in two parallel circuits such that one side of the two parallel circuits can be serviced while the other side remains operational.
[0010] There is, accordingly, an interest in developing a magnetic arrays filter element with more effective trapping characteristics and which can be more easily serviced.
BRIEF DESCRIPTION OF THE FIGURES
[0011] FIG. 1 is a cross-sectional view of a filter element of the present invention wherein an insert which induces a vortex in the fluid flow is used.
[0012] FIG. 2 is an exploded view of the embodiment of FIG. 1 .
[0013] FIG. 3 is a perspective view of a filter element of the present invention wherein a spiral-shaped insert is used to direct the fluid in a spiral flow pattern inside the filter element.
[0014] FIG. 4 is an exploded view of the embodiment of FIG. 3 .
[0015] FIG. 5 is a cross-sectional view of the embodiment of FIG. 3 .
[0016] FIGS. 6 a and 6 b are alternative arrangements of magnets of the filter elements of the present invention.
[0017] FIG. 7 a is a side view of an alternative embodiment of the filter of a filter of the present invention; FIG. 7 b is a cross-sectional view of the filter of FIG. 7 a ; FIG. 7 c is a partially exploded view of the filter of FIG. 7 a wherein the outer pressure wall has been removed to show the interior of the filter.
DESCRIPTION OF THE INVENTION
[0018] Illustrated in FIGS. 1 and 2 , generally at 10 , is a preferred embodiment of a filter element of the present invention. The filter element 10 includes a cylindrical filter housing 12 to which is affixed a top plate 14 and a bottom plate 16 . A non-ferrous liner 18 is received in a close fit inside the housing 12 . An insert 20 extends from the top plate 14 axially down the housing 12 , terminating above the bottom plate 16 . The insert 20 includes a central return tube 22 . Fluid is directed into the filter element 10 through a port 24 in the top plate 14 and is returned to the exterior of the filter element 10 via the return tube 22 . The insert 20 preferably has a plurality of radially extended plates 26 that act to introduce a flow pattern to fluid inside the filter element 10 . Encircling the exterior of the filter housing 12 are a plurality of annular rings of magnets 28 which will act to attract ferrous contaminants present in the fluid where they will be held against the liner 18 .
[0019] In certain embodiments, it may be desirable to induce a predetermined flow pattern of the fluid inside the filter element 10 so as to improve the filtering efficiency of the filter element 10 . For example, inducing a vortex in the fluid around the longitudinal axis will increase the residence time of the fluid inside the filter element 10 and will also cause a centripetal force that will urge the higher density ferrous contaminants toward the liner 18 and arrays of magnets 28 . The vortex can be induced by angling of the port 24 and by selecting a shape and placement of the plates 26 that will help maintain the vortical flow.
[0020] Illustrated in FIGS. 3 and 4 , generally at 110 is an alternative embodiment of the present invention filter element. The filter element 110 includes a cylindrical filter housing 112 to which is affixed a top plate 114 and a bottom plate 116 . A non-ferrous liner 118 is received in a close fit inside the housing 112 . An insert 120 extends from the top plate 114 axially down the housing 112 , terminating above the bottom plate 116 . The insert 120 includes a central return tube 122 . Fluid is directed into the filter element 110 through a port 124 in the top plate 114 and is returned to the exterior of the filter element 110 via the return tube 122 . The insert 120 has helical fighting 126 to induce a spiral flow pattern to fluid inside the filter element 110 . Encircling the exterior of the filter housing 112 are a plurality of annular rings of magnets 128 which will act to attract ferrous contaminants present in the fluid where they will be held against the liner 118 . The helical fighting 126 acts to increase the residence time of fluid inside the filter element 110 and creates a centripetal force that will urge higher density ferrous contaminants into proximity of the liner 118 and magnet arrays 128 .
[0021] A further preferred embodiment is illustrated generally at 210 in FIG. 5 . It is similar to filter element 110 except that the magnet arrays 228 , including individual magnets 130 , have been placed inside the filter housing 112 but outside the non-ferrous liner 118 . By placing the magnet arrays 228 inside the filter housing 112 , any shielding effect of the filter housing 112 will be eliminated and the capture of ferrous contaminants improved. If desired, a plurality of openings can be created in the liner 118 , preferably not in the areas of the magnets 130 , to allow the pressure to equalize on either side of the liner 118 .
[0022] The individual magnets 130 may be arranged in at least two different ways. The magnets may be arranged in adjacent pairs of alternating polarity, as illustrated in FIG. 6 a and similar to that described in U.S. Pat. No. 7,662,282 (which is incorporated herein in its entirety by this reference), or as individual magnets spaced apart from each other with alternate magnets having opposite polarity, as illustrated in FIG. 6 b.
[0023] In certain applications, it may be preferable to provide a port in the bottom plate 16 , 116 through which compressed gas can be directed into the filter housing 12 , 112 , to assist in purging fluid from the filter 10 , 110 .
[0024] An alternative embodiment is illustrated in FIGS. 7 a - 7 c, wherein the filter is illustrated generally at 210 . The filter 210 includes a filter housing or pressure vessel wall 212 to which is affixed a top plate 214 and a bottom plate 216 . A non-ferrous liner 218 is received in a close fit inside the housing 212 . An insert 220 is comprised of a central, closed spacer tube 222 about which are arranged in a vertically spaced, stacked relationship a plurality of spacer plates 224 . Each spacer plate 224 has a partial annular shape wherein a portion of an otherwise annular piece of material has been removed, as at 226 in FIG. 7 c . The arrangement of the removed sections 226 alternate from one side of the filter 210 for odd-numbered spacer plates 224 to the opposite side of the filter 210 for even-numbered spacer plates 224 .
[0025] Oil to be filtered is introduced into the filter 210 at inlet 230 and is removed from the filter 210 at outlet 232 . The path of the oil inside the filter 210 is determined by the arrangement of the removed sections 226 of the stacked spacer plates 224 . Since the removed sections 226 alternate sides of the filter 210 as described, the oil is forced to go from one side of the filter 210 to the other side as it encounters each spacer plate 224 . The path of the oil through the filter 210 is thus increased as is the residence time it spends near the circumferential periphery of the filter 210 . The oil thus has a stepped flow path in contrast to the spiral flow path of the filter 10 . A series of magnet arrays 228 , similar to those described in the other embodiments are arranged outside the filter housing 212 and will serve to trap ferrous contaminants against the non-ferrous liner 218 . An advantage of the embodiment filter 210 is that the stacked spacer plates can be easily and inexpensively manufactured, for example, by laser cutting.
[0026] The foregoing description and drawings comprise illustrative embodiments of the present inventions. The foregoing embodiments and the methods described herein may vary based on the ability, experience, and preference of those skilled in the art. Merely listing the steps of the method in a certain order does not constitute any limitation on the order of the steps of the method. The foregoing description and drawings merely explain and illustrate the invention, and the invention is not limited thereto, except insofar as the claims are so limited. Those skilled in the art who have the disclosure before them will be able to make modifications and variations therein without departing from the scope of the invention.
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A filter for removing ferrous particles from a fluid. The filter has an outer filter housing and a non-ferrous liner inside the housing. A plurality of magnets are longitudinally extended at intervals outside the liner. An insert inside the liner imparting a directional flow to the fluid inside the filter whereby ferrous particles in the fluid are trapped by the magnets and held against the non-ferrous line.
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BACKGROUND OF THE INVENTION
This application is based upon and claims priority of Japanese Patent Applications No. 2001-081908 filed on Mar. 22, 2001 and No. 2001-102934 filed on Apr. 2, 2001, the contents being incorporated herein by reference.
1. Field of the Invention
The present invention relates to a position detector and an attitude detector.
2. Description of Related Art
In this field of the art, especially in a robot vision, game machine and pointing device, various methods of detecting a position on a screen have been proposed. The typical one of the methods detects the desired position on the basis of the image of a standard or marks on the screen taken by a camera.
Examples of the above position detector are disclosed in Japanese Patent Publication Nos. Hei 6-35607, Hei 7-121293 and Hei 11-319316.
Also, a system for adjusting a video projector has been well known, in which a video camera captures a test pattern image displayed on a screen. However, if the video projector and the video camera have different vertical scanning frequencies from each other, a flickering pattern of bright and dark bands would be caused in the image taken by the video camera. In order to solve the problem, various proposals have been made, such as in Japanese Patent Publication Nos. Hei 5-30544, Hei 8-317432 and Hei 11-184445.
For example, Japanese Patent Publication No. Hei 11-184445 discloses an imaging system in which the timing of the start and the end of photographing in a video camera is controlled by generating a shutter control signal in accordance with the vertical synchronizing signal of a display apparatus.
However, there have been problems and disadvantages still left in the related arts, especially as to the convenience, accuracy or quickness of the detection.
SUMMARY OF THE INVENTION
In order to overcome the problems and disadvantages, the invention provides a position detector for detecting a position on a given plane. The position detector comprises a first controller for displaying a target point on the given plane and a second controller for displaying a known standard on the given plane in the vicinity of the target point with the location of the standard being known. The position detector further comprises an image sensor having an image plane on which an image that includes an image of the standard is formed, the image plane having a predetermined position. Also in the position detector according to the present invention, an image processor identifies the image of the standard on the image plane, and a processor calculates a position of a point on the given plane corresponding to the predetermined position on the image plane using parameters of an attitude of the image plane relative to the given plane based on the identified image of the standard.
Thus, the known standard can always be sensed on the image plane of the image sensor as long as the target point is aimed at even if the field angle of the image sensor is not so wide.
The above advantage is typical in accordance with a detailed feature of the present invention. In the detailed feature, the first controller displays the target point at different positions on the given plane, and the second controller displays the known standard at different positions on the given plane in correspondence to the different positions of the target point. Alternatively, the first controller displays one of different target points on the given plane, and the second controller displays the known standard in the vicinity of the one of the different target points on the given plane. Thus, the known standard always keeps up with the target no matter where the aimed target point is located or moved on the given plane.
According to another feature of the present invention, the known standard includes an asymmetric pattern. For example, the asymmetric pattern includes four marks forming a rectangle, one of the four marks being distinguishable from the others. This makes it possible to determine the rotary attitude of the image plane of the image sensor relative to the given plane.
According to still another feature of the present invention, the known standard includes a first standard and a second standard sequentially displayed on the given plane, wherein the image sensor senses a first image that includes an image of the first standard and a second image that includes an image of the second standard, and wherein the processor includes a calculator that calculates the difference between the first image and the second image to identify the image of the standard. In more detail, the processor determines whether the difference is positive or negative at the identified standard.
According to a further feature of the present invention the first standard and the second standard include a plurality of marks, respectively, the marks of the second standard being located at the same positions as the marks of the first standard with the pattern formed by the marks in the second standard being a reversal of that in the first standard.
The above features give the standard a high advantage in the detection thereof as well as the realization of its asymmetry.
According to another feature of the present invention, the first controller forms an image by scanning the given plane, the target point is displayed as a part of the image formed by the scanning, and the second controller displays the known standard as a part of the image formed by the scanning.
In more detail, the image sensor reads out the sensed image upon the termination of at least one period of the scanning.
According to another detailed feature the known standard includes the first standard and the second standard sequentially displayed on the given plane, the second controller starts displaying the second standard upon the initiation of the scanning after the image sensor completes the reading out of the sensed image that includes the first standard.
The above features are advantageous for the image sensor to sense the image on the given plane in synchronism with the scanning of the given plane by the first controller.
The above features and advantages according to the present invention are not only applicable to the position detector, but also to an attitude detector in its essence. Further, the above features and advantages relating to synchronization of the function of the image sensor with the scanning of the given plane is not only applicable to the position detector or the attitude detector, but also to a detector in general for detecting a standard on a given plane in its essence.
Other features and advantages according to the invention will be readily understood from the detailed description of the preferred embodiment in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 represents a perspective view of the first embodiment of a shooting game machine.
FIG. 2 represents a block diagram of the embodiment according to the present invention.
FIG. 3 represents a detailed block diagram of image processor 50 .
FIG. 4 represents a perspective view of controller 100 .
FIG. 5 represents a cross sectional view of the optical system in the controller 100 .
FIG. 6 represents a flowchart of the basic operation of the shooting game according to the present invention.
FIG. 7 shows the manner of calculating the coordinate of the target point.
FIG. 8 represents the image q taken by the controller 100 .
FIG. 9 is to explain the coordinate conversion.
FIG. 10 is an explanation of the spatial relationship between X-Y-Z coordinate and X*-Y* coordinate.
FIG. 11 represents the pair of standard images Kt 1 and Kt 2 both with four marks.
FIG. 12 represents a flowchart of the functions of sensing image
FIG. 13 represents sensed image q taken by CCD 101 of controller 100 .
FIG. 14 represents timing charts of the function of controller 100 in sensing images.
FIG. 15 represents a flowchart of the function of controller 100 .
FIG. 16 represents the image signals for the four marks.
FIG. 17 represents an illustration of images for explaining the identification of the mark position.
FIG. 18 represents a flowchart for identifying the mark positions.
FIG. 19 represents the projected image on the wide screen
FIG. 20 represents a timing chart of the second embodiment.
FIG. 21 represents a flowchart of the function of controller 100 according to the second embodiment.
FIG. 22 represents a timing chart of the function of controller 100 according to the third embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[First Embodiment]
FIG. 1 represents a perspective view of the first embodiment of a shooting game machine on the basis of the position and attitude detecting system according to the present invention. Projector 130 projects on wide screen 110 a scene according to the shooting game story.
Projected scene 111 includes target object A, which is a flying object, as well as a standard image including four detection marks mQ 1 , mQ 2 , mQ 3 , mQ 4 surrounding target object A, the positions of the detection marks relative to target object A being predetermined in the projected scene 111 . The player at point PS in front of wide screen 110 is to shoot the target object A at a predetermined point Ps with controller 100 formed as a gun, controller 100 serving as a sensor of the position and attitude detecting system.
In FIG. 1 , the respective centers of gravity of the four marks are defined as characteristic points mQ 1 , mQ 2 , mQ 3 and mQ 4 , which in combination form a rectangular. The position of image on the screen is identified with X*-Y* coordinate named “screen coordinate” with its origin at predetermined point Ps.
Though four detection marks are adopted as the standard image in the above embodiment, any alternative may be adopted as the standard as long as it can define a rectangle.
FIG. 2 represents a block diagram of the embodiment according to the present invention, in which the manner of sensing image is explained.
Controller 100 includes objective lens 102 , image sensor 101 such as CCD (hereinafter referred to as CCD 101 ), trigger switch 103 for the player to take the picture on CCD 101 upon shooting the target, A/D converter 104 for converting the output of CCD 101 into digital image data, timing generator 105 for generating various clock signals necessary for CCD 101 to sense the image, synchronization signal detector 106 for picking up only the vertical synchronization signals among image signals transmitted to the image projector, and interface 107 for communicating with main body 120 of the game machine (or the personal computer). Though controller 100 also includes other conventional elements, such as power source, they are omitted from FIG. 2 for simplification.
The image signal taken by controller 100 is output from interface 107 for transmission to interface 121 of main body 120 . As interface 107 and 121 , various wired or wireless means may be adopted, such as USB, IEEE1294, IrDA or Bluetooth or the like. If main body 120 is provided with the conventional video board within the housing, the analog signal generated by CCD 101 may be directly input into main body 120 since such a video board normally includes an A/D converter.
Main body 120 includes timing generator 123 for synchronization with image signal, display controller 124 for controlling the video signal on display, and image processor 50 , which processes image according to a predetermined program. Image processor according to the embodiment carries out the extraction of the four marks and necessary calculations thereon for detecting the position of target object.
Display controller 124 outputs video signal to projector 130 at the same cycle as the vertical synchronization signals generated by timing generator 123 .
Synchronizing signal detector 106 located within controller 100 in the embodiment may be modified to locate within main body 120 .
The display according to the embodiment, in which projector 130 projects image on wide screen 110 , may modified to be replaced by a cathode ray tube (CRT) display, a liquid crystal device (LCD) display, or the like.
FIG. 3 represents a detailed block diagram of image processor 50 .
In FIG. 3 , image processor 50 includes characteristic point detector 51 , position calculator 6 and image generator 9 .
Characteristic point detector 51 includes difference calculator 511 for extracting marks characterizing a rectangle on the basis of a difference between a pair of standard images of different illumination. Characteristic point detector 51 also includes a binary processor 512 .
Mark identifier 513 is for calculating the coordinate of the center of gravity of each mark and distinguishes a mark from the others.
Position calculator 52 includes attitude calculator 521 for calculating the attitude of the wide screen relative to controller 100 and target point calculator 522 for calculating the coordinate of the target object.
Hit comparator 8 judges whether or not one of the objects is shot in one of its portions by means of comparing the position of each portion in each object with the position calculated by coordinate calculator 522 . Hit comparator 8 is informed of positions of all portions in all objects to identify the shot object with its specific portion.
Image generator 9 superimposes the relevant objects on the background virtual reality space for display on screen 110 by projector 130 . In more detail, image generator 9 includes movement memory 91 for storing a movement data predetermined for each portion of each object, the movement data being to realize a predetermined movement for any object if it is shot in any portion. Further included in image generator 9 is coordinate calculator 92 for converting a movement data selected from movement memory 91 into a screen coordinate through the perspective projection conversion viewed from an image view point, i.e. an imaginary camera view point, along the direction defined by angles α, γ and ψ. Image generator superimposes the calculated screen coordinate on the data of the background virtual reality space by means of picture former 93 , the superimposed data thus obtained being stored in frame memory 94 .
Picture former 93 controls the picture formation of the objects and the background virtual reality space in accordance with the advance of the game. For example, a new object will appear in the screen or an existing object will move within the screen in accordance with the advance of the game.
The superimposed data of objects and the background virtual reality space temporarily stored in frame memory 94 is combined with the scroll data to form a final frame image data to be projected on screen 110 by projector 130 .
FIG. 4 represents a perspective view of controller 100 .
In FIG. 4 , the controller 100 has the shutter release button 103 of a camera 100 to be transmitted toward the target for visually pointing the target point on the screen plane. The sighting device 200 is the light beam emitter or the optical finder for the purpose of aiming the target point so that the target point is sensed at the predetermined point on the image sensing plane of CCD 101 .
Controller 100 further has control buttons 14 , 15 to have an object character jump or go up and down, or backward and forward, which is necessary for advancing the game. Input/output interface 3 processes the image data by A/D converter, and transfers the result to image processor.
FIG. 5 represents a cross sectional view of the optical system in the controller 100 using the light beam emitter as the sighting device 200 . If a power switch is made on, the laser beam is emitted at light source point 200 A and collimated by collimator 200 B to advance on the optical axis of camera lens 102 toward rectangular plane 110 by way of mirror 200 C and semitransparent mirror 13 A. Camera 100 includes objective lens 102 and CCD 101 for sensing image through semitransparent mirror 13 A, the power switch of the laser being made off when the image is sensed by camera 100 . Therefore, mirror 13 A may alternatively be a full refractive mirror, which is retractable from the optical axis when the image is sensed by camera 100 .
The followings will give the explanation of the manner of detecting the position and attitude.
(a) Position Calculation
Position calculator calculates a coordinate of a target point Ps on a screen plane defined by characteristic points, the screen plane being located in a space.
FIG. 6 represents a flowchart of the basic operation of the shooting game according to the present invention.
In step S 100 , the main power of the controller is turned on. In step S 101 , the target point on a screen plane having the plurality of characteristic points is aimed so that the target point is sensed at the predetermined point on the image sensing plane of CCD 101 . According to the first embodiment, the predetermined point is specifically the center of image sensing plane of CCD 101 at which the optical axis of the objective lens 102 of camera intersects.
In step S 102 , the image is taken in response to shutter switch (trigger switch) 103 of the camera 100 with the image of the target point at the predetermined point on the image sensing plane of CCD 101 .
In step S 103 , the characteristic points defining the rectangular plane are identified each of the characteristic points being the center of gravity of each of predetermined marks, respectively. The characteristic points are represented by coordinate q 1 , q 2 , q 3 and q 4 on the basis of image sensing plane coordinate.
Step S 104 is for processing the rotational parameters for defining the attitude of the screen plane in a space relative to the image sensing plane, and step S 105 is calculating the coordinate of the target point on the screen plane, which will be explained later in detail.
In step S 106 , the coordinate of position of the target point is compared with the coordinate of position calculated in step S 105 to find whether the distance from the position calculated by the processor to the position of the target point is less than a limit. In other words it is judged in step S 106 whether or not one of the objects is shot in one of its portions. If no object is shot in any of its portions in step S 106 , the flow returns to step S 101 to wait for next trigger by the player since it is shown in step 106 that the player fails in shooting the object.
If it is judged in step 106 that one of the objects is shot in one of its portions, the flow advances to step S 107 , where a predetermined movement is selected in response to the identified shot portion. In more detail, in step S 107 , the movement data predetermined for the shot portion is retrieved from movement memory 91 to realize the movement for the shot portion. If such movement data includes a plurality of polygon data for a three-dimensional object, a movement with high reality of the object is realized by means of selecting the polygon data in accordance with the attitude calculated in step S 104 .
In step S 108 the data of movement of the target given through step S 109 is combined with the data of position and direction of the player given through step for forming a final image to be displayed on screen 110 by projector 130 . The data of position of the player will give a high reality of the change in the target and the background space on screen 110 in accordance with the movement of the player relative to screen 110 .
FIG. 7 shows the manner of calculating the coordinate of the target point and corresponds to the details of step 105 in FIG. 6 .
FIG. 8 represents the image q taken by the controller 100 . In FIG. 8 image of target point Ps is in coincidence with predetermined point Om, which is the origin of the image coordinate. Characteristic points q 1 , q 2 , q 3 and q 4 are the images on the image sensing plane of the original of characteristic points mQ 1 , mQ 2 , mQ 3 and mQ 4 on the rectangular plane represented by X*-Y* coordinate.
(a1) Attitude Calculation
Now, the attitude calculation, which is the first step of position calculation, is to be explained in conjugation with the flow chart in FIG. 7 .
The parameters for defining the attitude of the given plane with respect to the image sensing plane are rotation angle γ around X-axis, rotation angle ψ around Y-axis, and rotation angle α or β around Z-axis.
Referring to FIG. 7 , linear equations for lines q 1 q 2 , q 2 q 3 , q 3 q 4 and q 4 q 1 are calculated on the basis of coordinates for detected characteristic points q 1 , q 2 , q 3 and q 4 in step S 201 , lines q 1 q 2 , q 2 q 3 , q 3 q 4 and q 4 q 1 being defined between neighboring pairs among characteristic points q 1 , q 2 , q 3 and q 4 , respectively. In step S 202 , vanishing points T 0 and S 0 are calculated on the basis of the liner equations.
The vanishing points defined above exist in the image without fail if a rectangular plane is taken by a camera. The vanishing point is a converging point of lines. If lines q 1 q 2 and q 3 q 4 are completely parallel with each other, the vanishing point exists in infinity.
According to the first embodiment, the plane located in a space is a rectangular having two pairs of parallel lines, which cause two vanishing points on the image sensing plane, one vanishing point approximately on the direction along the X-axis, and the other along the Y-axis.
In FIG. 8 , the vanishing point approximately on the direction along the X-axis is denoted with S 0 , and the other along the Y-axis with T 0 . Vanishing point T 0 is an intersection of lines q 1 q 2 and q 3 q 4 .
In step S 203 , linear vanishing lines OmS 0 and OmT 0 , which are defined between vanishing points and origin Om, are calculated.
Further in step S 203 , vanishing characteristic points qs 1 , qs 2 , qt 1 and qt 2 , which are intersections between vanishing lines OmS 0 and OmT 0 and lines q 3 q 4 , q 1 q 2 , q 4 q 1 and q 2 q 3 , respectively, are calculated.
The coordinates of the vanishing characteristic points are denoted with qs 1 (Xs 1 ,Ys 1 ), qs 2 (Xs 2 ,Ys 2 ), qt 1 (Xt 1 ,Yt 1 ) and qt 2 (Xt 2 ,Yt 2 ). Line qt 1 qt 2 and qs 1 qs 2 defined between the vanishing characteristic points, respectively, will be called vanishing lines as well as OmS 0 and OmT 0 .
Vanishing lines qt 1 qt 2 and qs 1 qs 2 are necessary to calculate target point Ps on the given rectangular plane. In other words, vanishing characteristic points qt 1 , qt 2 , qs 1 and qs 2 on the image coordinate (X-Y coordinate) correspond to points T 1 , T 2 , S 1 and S 2 on the plane coordinate (X*-Y* coordinate) in FIG. 1 , respectively.
If the vanishing point is detected in infinity along X-axis of the image coordinate in step S 202 , the vanishing line is considered to be in parallel with X-axis.
Instep S 204 , image coordinate (X-Y coordinate) is converted into X′-Y′ coordinate by rotating the coordinate by angle β around origin Om so that X-axis coincides with vanishing line OmS 0 . Alternatively, image coordinate (X-Y coordinate) may be converted into X″-Y″ coordinate by rotating the coordinate by angle α around origin Om so that Y-axis coincides with vanishing line OmT 0 . Only one of the coordinate conversions is necessary according to the first embodiment.
FIG. 9 is to explain the coordinate conversion from X-Y coordinate to X′-Y′ coordinate by rotation by angle β around origin Om with the clockwise direction is positive. FIG. 9 also explains the alternative case of coordinate conversion from X-Y coordinate to X″-Y″ coordinate by rotating the coordinate by angle α.
The coordinate conversion corresponds to a rotation around Z-axis of a space (X-Y-Z coordinate) to determine one of the parameters defining the attitude of the given rectangular plane in the space.
By means of the coincidence of vanishing line qs 1 qs 2 with X-axis, lines mQ 1 mQ 2 and mQ 3 mQ 4 are made in parallel with X-axis.
In step S 205 , characteristic points q 1 , q 2 , q 3 and q 4 and vanishing characteristic points qt 1 , qt 2 , qt 3 and qt 4 on the new image coordinate (X′-Y′ coordinate) are related to characteristic points mQ 1 , mQ 2 , mQ 3 and mQ 4 and points T 1 , T 2 , S 1 and S 2 on the plane coordinate (X*-Y* coordinate). This is performed by perspective projection conversion according to the geometry. By means of the perspective projection conversion, the attitude of the given rectangular plane in the space (X-Y-Z coordinate) on the basis of the image sensing plane is calculated. In other words, the pair of parameters, angle ψ around Y-axis and angle γ around X-axis for defining the attitude of the given rectangular plane are calculated.
In step S 206 , the coordinate of target point Ps on the plane coordinate (X*-Y* coordinate) is calculated on the basis of the parameters gotten in step S 205 . The details of the calculation to get the coordinate of target point Ps will be discussed later in section (a2).
Perspective projection conversion is for calculating the parameters (angles ψ and angle γ) for defining the attitude of the given rectangular plane relative to the image sensing plane on the basis of the four characteristic points identified on image coordinate (X-Y coordinate).
FIG. 10 is an explanation of the spatial relationship between X-Y-Z coordinate (hereinafter referred to as “image coordinate”) representing the equivalent image sensing plane in a space and X*-Y* coordinate (hereinafter referred to as “plane coordinate”) representing the given rectangular plane. Z-axis of image coordinate intersects the center of the equivalent image sensing plain perpendicularly thereto and coincides with the optical axis of the objective lens. View point O for the perspective projection conversion is on Z-axis apart from origin Om of the image coordinate by f. Rotation angle γ around X-axis, rotation angle ψ around Y-axis, and two rotation angles α and β both around Z-axis are defined with respect to the image coordinate, the clockwise direction being positive for all the rotation angles. With respect to view point O, Xe-Ye-Ze coordinate is set for perspective projection conversion, Ze-axis being coincident with Z-axis and Xe-axis and Ye-axis being in parallel with which will X-axis and Y-axis, respectively.
Equations (1) and (2) are conclusion of defining angle γ an ψ which are the other two of parameters for defining the attitude of the given rectangular plane relative to the image sensing plane. The value for tan γ given by equation (1) can be practically calculated by replacing tan ψ by the value calculated through equation (2). Thus,all of the three angles β, γ and ψ are obtainable.
tan γ = - 1 tan ϕ · X t1 ′ Y t1 ′ ( 1 ) tan ϕ = Y 1 ′ - Y t1 ′ X t1 ′ Y 1 ′ - X 1 ′ - Y t1 ′ · f ( 2 )
In the case of equations (1) and (2), at least one coordinate of characteristic point q 1 (X′ 1 , Y′ 1 ), at least one coordinate of a vanishing characteristic point qt 1 (X′t 1 , Y′t 1 ) and distance f are only necessary to get angles γ and ψ.
(a2) Coordinate Calculation
Now, the coordinate calculation for determining the coordinate of the target point on the given rectangular plane is to be explained. The position of target point Ps on given rectangular plane 110 with the plane coordinate (X*-Y* coordinate) in FIG. 1 is calculated by coordinate calculator 522 in FIG. 3 on the basis of the parameters for defining the attitude of the given rectangular plane obtained by attitude calculator 521 .
The coordinate of the target point Ps on the given rectangular plane can be expressed as in the following equation (3) using ratio m=OmS 1 /OmS 2 and ratio n=OmT 1 /OmT 2 .
P s ( u , v ) = ( m m + 1 · U max , n n + 1 · V max ) ( 3 ) m = O m S 1 _ O m S 2 _ = | X s1 ′ | | X s2 ′ | · | X s2 ′ · tan ϕ + f | | X s1 ′ · tan ϕ + f | ( 4 ) n = O m T 1 _ O m T 2 _ = | X t1 ′ | | X t2 ′ | · | f · tan ϕ - X t2 ′ | | f · tan ϕ - X t1 ′ | ( 5 )
(b) Characteristic Point Detection
The function of the characteristic point detector is as follows:
(b1) The Standard Image
According to the embodiment, the mark is extracted by means of the difference method, For the difference method, a pair of standard images of different illumination are prepared, the images being displayed according to the time sharing. In the embodiment, the pair of standard images consists of a first image and a second image both with four marks, the color of which differs between green in the first state and black in the second state.
FIG. 11 represents the pair of standard images Kt 1 and Kt 2 both with four marks.
FIG. 11A represents first standard image Kt 1 , in which the upper-left mark is green in the first state and the others are black in the second state. On the other hand, FIG. 11B represents second standard image Kt 2 , in which the upper-left mark is black in the second state and the others are green in the first state. The relationship of the four marks is reversed between first standard image Kt 1 and second standard image Kt 2 . Further, one of the marks is distinguishable from the other three, which causes an asymmetry color arrangement of the four marks.
The one mark of the color different from those of the other three marks makes it possible to determine the rotary attitude of the image plane of CCD 101 relative to wide screen 110 . Further, only two colors, i.e., black and green, are used to represent all the marks in the pair of standard images, CCD 101 can easily extract the four marks without any difficulty of sensing a color difficult to detect, which removes conditions necessary for successful extraction of the marks.
(b2) Sensing of the Projected Standard Image
FIG. 12 represents a flowchart of the functions of sensing image to detecting the characteristic points. In the flowchart, steps S 301 and S 302 correspond to the sensing of the image projected on the wide screen. Steps S 303 to S 308 correspond to the difference calculation to the characteristic points detection, which will be referred to in subparagraph (b3).
The first standard image Kt 1 is projected on the wide screen and sensed by the image sensor in step S 301 , while the second standard image Kt 2 is projected on the wide screen and sensed by the image sensor in step S 302 .
As shown in FIG. 1 , the target object is projected on the wide screen. If a player operates trigger switch 103 with controller 100 aimed at a specific portion of the target object, step S 301 and step S 302 are successively carried out to sense the four marks located at a predetermined position relative to the target object.
FIG. 13 represents sensed image q taken by CCD 101 of controller 100 located at point Ps in FIG. 1 . Detected point Ps is set at the center of the sensed image, which is the origin of image coordinate X-Y and coincides with a specific point of the target object, e.g., a wing of the flying object, if the specific point is correctly aimed.
According to the embodiment, the marks are prepared and indicated at a predetermined position adjacent to the target object in conformity with the advance of game story.
FIG. 14 represents timing charts of the function of controller 100 in sensing images. FIG. 14( a ) represents the timing of START pulse for starting the image sensing, which is generated when trigger switch 103 of controller 100 is operated by a player. START pulse is input into timing generator 105 and also into main body 120 through interfaces 107 and 121 . FIG. 14( b ) represents the timing of PJ signal, which is a composite video signal formed by adding vertical synchronization signals to the video signal transmitted from main body 120 to projector 130 . FIG. 14( c ) represents the timing of VDp signal, which is the vertical synchronization signal component extracted from the composite video signal transmitted from main body 120 . Main body 120 transmits to projector 130 the video signal for projecting the first standard image during period Tv between t 1 and t 2 directly following the generation of START pulse.
FIG. 14( d ) represents the timing of RST pulse, which is the reset pulse for CCD 101 . Timing generator 105 generates and transmits RST pulse to CCD 101 at time t 1 in synchronism with VDp signal. Following RST pulse, CCD 101 starts to sense the projected first standard image. FIG. 14( e ) represents the timing of RD start pulse to start reading out the accumulated charge on CCD. Timing generator 105 generates RD start pulse at time t 2 with period Tv passed after the transmission of RST pulse to CCD 101 . RD start pulse causes RD out signal in FIG. 14( f ) for reading out the accumulated charge on CCD 101 , RD out signal going on for time Tc. Then main body 120 repeats to generate PJ signals for a period three times as long as Tv, which continues the projection of the first standard image until time t 3 . The projection of the first standard image by projector 130 is substituted by that of the second standard image at time t 3 , which starts with the first period Tv until time t 4 .
As in FIG. 14( d ) on the other hand, timing generator 105 generates and transmits to CCD 101 RST pulse at time t 3 to remove unnecessary charges. Then the charge on CCD 101 is read out during time Tc in FIG. 14( f ) starting with time t 4 when RD start pulse in FIG. 14( e ) is generated in synchronism with VDp pulse in FIG. 14( c ). The first standard image is not necessarily continued to be projected for a period three times as long as Tv, but to be projected for the first period Tv in a modified embodiment.
FIG. 15 represents a flowchart of the function of controller 100 . The flow begins with the operation of trigger switch 103 , which causes START pulse as in FIG. 14( a ) to be transmitted to timing generator 105 and main body 120 . Step S 401 wait for a first VDp signal for the projection of the first standard image. When the first VDp signal comes at time t 1 , the flow advances to step S 402 , in which main body 120 transmits PJ signal to projector 130 for projecting the first standard image. In step S 403 , timing generator 105 generates and transmits RST pulse to CCD 101 for removing unnecessary charges. In step S 404 , CCD 101 is exposed to the first standard image. The exposure is continued until the generation of the second VDp signal is detected in step S 405 . In step S 406 , when the exposure time is over at time t 2 , timing generator 105 generates and transmits RD start pulse as in FIG. 14( e ) to CCD 101 , which causes the reading out of the charge on CCD 101 during period time Tc.
If it is detected that the fourth VDp signal comes at time t 3 in step S 407 , the flow advances to step S 408 , in which main body 120 switches the projection of the first standard image into the second standard image. In step S 409 , timing generator 105 generates and transmits RST pulse to CCD 101 . In step 410 , CCD 101 is exposed to the second standard image. The exposure is continued until the generation of the fifth VDp signal is detected in step S 411 . In step S 412 , when the second exposure time is over at time t 4 , timing generator 105 generates and transmits RD start pulse as in FIG. 14( e ) to CCD 101 , which causes the reading out of the second standard image form CCD 101 during time Tc.
(b3) Difference Method and Characteristic Point Detection
Referring back to FIG. 12 , difference method is carried out in steps S 303 on the basis of difference between the first standard image gotten in step S 301 and the second standard image gotten in step S 302 .
FIG. 16 represents the image signals for the four marks, in which FIG. 16A represents the first standard image with marks mQ 1 , mQ 2 , mQ 3 and mQ 4 , FIG. 16B the second standard image with the four marks, and FIG. 16C the difference between the first and second images.
In step 304 of the flowchart in FIG.12 , the portions relating to the four marks are extracted from the difference in FIG. 16C by means of the binarization with respect to a predetermined threshold level. In step S 305 , the sign of the extracted portion of difference in FIG. 16C is determined for each mark between plus sign and minus sign, which is recorded for each mark.
In step S 306 , the position of center of gravity for each of the extracted marks is calculated. And, the individual positions of the four marks are identified in step S 307 on the basis of the position of center of gravity calculated in step S 306 and the sign recorded in step S 305 . In other words, mark mQ 4 can be distinguished from the other marks my means of the plus sign thereof different from the minus sign of the others. And, the other three marks can be identified in accordance with the predetermined arrangement as in FIG. 11 if mark mQ 4 is once identified. If the individual positions of the marks are identified through step S 307 , the flow goes to step S 308 to close the function.
FIG. 17 represents an illustration of images for explaining the identification of the mark position, in which FIG. 17A represents the projected image on the wide screen. On the other hand, FIG. 17B represents the sensed image taken by CCD 101 of controller 100 , in which the origin of X-Y coordinate is the position to be calculated on the basis of the identified mark positions.
FIG. 18 represents a flowchart for identifying the mark positions. The flow starting with step S 500 makes the identification of mQ 4 in step S 501 . In step S 502 , three formulas are calculated to represent three straight lines h 1 , h 2 and h 3 defined between the position of mQ 4 and the other three mark positions, respectively. With respect to the other three mark positions in this stage, no one can tell which is which.
In step S 503 , three formulas are calculated to represent three straight lines g 1 , g 2 and g 3 defined between all possible pairs among the other three mark positions, respectively.
In step S 504 , all possible intersections between one group of straight lines h 1 to h 3 and the other groups of straight lines g 1 to g 3 are calculated. In step 505 , the positions of the calculated intersections are compared with the four mark positions to find out intersection mg located at a position other than the four mark positions.
And, a pair of straight lines causing intersection mg is found out in step S 506 . Thus, straight line h 2 and straight line g 3 are identified as the pair of straight lines causing intersection mg. Then mQ 2 can be identified on line h 2 on the other side of mg than mQ 4 in step S 507 .
With respect to mQ 1 and mQ 3 on straight line g 3 , discrimination is made in steps S 508 and S 509 to tell which is which. In step S 508 , one of the remaining mark positions is selected so that the coordinates of the selected mark position are substituted for x and y of the formula, y=a2x+b2 representing straight line h 2 . And, it is tested in step S 509 whether or not the following conditions are both fulfilled:
y>a 2 x+b 2 and a 2>0
If the answer is affirmative, the flow goes to step S 510 for determining that the mark position selected in step S 508 is mQ 3 . On the other hand, the flow goes to step S 511 for determining that the mark position selected in step S 508 is mQ 1 if the answer is negative.
Thus, the last one mark position can be identified, and the flow is closed in step S 512 .
According to the present invention, the four marks necessary for calculating the aimed position, which is the origin of X-Y coordinate in the sensed image taken by CCD 101 , is located close to the target object in the projected image. And the positions of the four marks are shifted along with the movement of the target object over the wide screen. Accordingly, the four marks can always be sensed on the image plane of CCD 101 as long as the player aims the target object with controller 100 even if the field angle of objective lens 102 is not so wide.
FIG. 19 represents the projected image on the wide screen in various cases for explaining the above feature. FIG. 19A represents a case in which flying object A as the target object is located in the upper-right portion of the wide screen, characteristic points mQ 1 , mQ 2 , mQ 3 and mQ 4 being located close to flying object. FIG. 19B represents a case in which flying object A moves toward the lower-left direction, characteristic points mQ 1 , mQ 2 , mQ 3 and mQ 4 keeping up flying object A. FIG. 19C represents a case in which spire B of a steeple as another target object is located in the central portion of the wide screen, characteristic points mQ 1 , mQ 2 , mQ 3 and mQ 4 being located not close to flying object A, but to spire B. This means that the player does not aim at flying object A, but at spire in the case of FIG. 19C .
For changing the target object to be aimed at, controller 100 includes a selector button for the player to designate one of the selectable target objects. Alternatively, an automatic designation of the target object is possible by means of automatically identifying a target object within the field angle of objective lens 102 . Such identification is possible by having each of the target objects flicker with a predetermined different frequency. Thus, the target object coming into the field angle of objective lens 102 is identified in dependence on its frequency of flicker to automatically change the designation of the target object with characteristic points mQ 1 , mQ 2 , mQ 3 and mQ 4 located close thereto.
In all the cases in FIG. 19 , the positions of the characteristic points are known no matter where the characteristic points located. Thus, the point where the player aims with controller 100 can be calculated as long as controller 100 senses the characteristic points.
[Second Embodiment]
Ordinary game machine outputs video signal with display scan frequency of 50 to 80 Hz (i.e., display scan period Tv of 1/50sec. to 1/80sec.) On the other hand, it takes time Tc (e.g., 1/50sec for PAL or 1/60sec. for NTSC in the case of ordinary video signal) for CCD to output signal for one entire image.
If period Tv does not so differ from time Tc with the former being shorter than the latter, the period three times as long as Tv for projecting the first standard image is sufficient for CCD to output the sensed first standard image as in the first embodiment.
On the contrary, a period two times as long as Tv for projecting the first standard image may be sufficient for CCD to output the sensed first standard image if period Tv is relatively longer than time Tc. This may also be possible if time Tc is successfully shortened so as to be shorter than period Tc. Thus, the projection of the first standard image by projector 130 may be substituted by that of the second standard image after a lapse of the period two times as long as Tv. The second embodiment in FIG. 20 is prepared to realize such a prompt substitution of the first standard image by the second standard image succeeding the termination of time Tc.
FIG. 20( a ) to FIG. 20( f ) are similar to FIG. 14( a ) to FIG. 14( f ). In the second embodiment, however, RD end pulse as in FIG. 20( g ) to be generated from timing generator 105 at time t 5 upon the termination of reading out the sensed image from CCD is added. RD end pulse in FIG. 20( g ) has main body 120 substitute the projection of the first standard image by that of the second standard image at time t 3 , at which the fist VDp pulse in FIG. 20( c ) comes after the generation of RD end pulse at time t 5 . Further, RD end pulse in FIG. 20( g ) causes main body 120 to generate RST pulse in FIG. 20( d ).
In the case of FIG. 20 itself, the substitution of the first standard image by the second standard image succeeds the period three times as long as Tv, which is similar to FIG. 14 , because period Tv is shorter than time Tc. If period Tv is made relatively longer than time Tc, however, the substitution of the first standard image by the second standard image would promptly succeed the period two times as long as Tv according to the second embodiment. According to the second embodiment, an additional controlling cable connects between controller 110 and main body 120 to transmit RD end pulse.
The prompt substitution of the first standard image by the second standard image succeeding the termination of reading out the sensed first standard image from CCD is also possible by modifying the first embodiment, in which RD end pulse and the cable for transmitting it as in the second embodiment are not necessary. In such a modification, main body 120 in the first embodiment includes a switch for changing the repetition of generating PJ signals from the period three times as long as Tv to a period two times as long as Tv if period Tv is relatively longer than time Tc. In other words, step S 407 in FIG. 15 is modified to detect whether the third VDp signal (instead of the fourth VDp signal) comes if period Tv is relatively longer than time Tc.
FIG. 21 represents a flowchart of the function of controller 100 according to the second embodiment. Steps S 601 to S 606 from the projection of the first standard image to the reading out of the charge on CCD 101 are similar to steps S 401 to S 406 in FIG. 15 .
In step S 607 a , it is checked whether or not the reading out of the charge on CCD is over. If the reading out is over at time t 5 , the flow advances to step S 607 b , in which timing generator 105 generates RD end pulse as in FIG. 20( g ) for transmitting it through interfaces 107 and 121 to main body 120 . In response to RD end pulse, the flow waits for the next VDp signal in step S 608 . If it is detected that the next VDp signal comes at time t 3 in step S 608 , the flow advances to step S 609 , in which main body 120 switches the projection of the first standard image into the second standard image.
In step S 610 , timing generator 105 generates and transmits RST pulse to CCD 101 . In step 611 , CCD 101 is exposed to the second standard image. The exposure is continued until the generation of the next VDp signal is detected in step S 612 . In step S 613 , when the second exposure time is over at time t 4 , timing generator 105 generates and transmits RD start pulse as in FIG. 20( e ) to CCD 101 , which causes the reading out of the second standard image form CCD 101 during time Tc.
[Third Embodiment]
In the first and second embodiments, CCD 101 is exposed to the standard image for period Tv, which is one display scan period. However, in the case of CCD of lower sensitivity, the exposure for only one display scan period would be insufficient for getting the expected level of image signal. The third embodiment is designed with such a case taken into consideration.
FIG. 22 represents a flowchart of the function of controller 100 according to the third embodiment. FIG. 22( a ) to FIG. 20( g ) can be understood in the similar manner to that in FIG. 20( a ) to FIG. 20( g ) in the second embodiment.
In the third embodiment, however, timing generator 105 is modified to generate RD start pulse at time t 2 with period two times as long as Tv passed after the transmission of RST pulse to CCD 101 as in FIG. 22( e ). Thus, CCD 101 is exposed to the standard image with double amount of light, which increases the level of image signal with undesired influence of flicker modulated. According to the concept of the third embodiment, timing generator 105 may be further modified to generate RD start pulse with period three or more times as long as Tv if CCD requires more amount of light exposed.
According to the present invention, various types of further modification of the embodiment are possible. For example, the four detection marks forming a rectangular may be modified into other type of geometric pattern. Or, the first and second standard images of different illumination may be modified into a pair of standard images of different contrast.
As in FIG. 15 or FIG. 20 or FIG. 22 , the embodiment according to the present invention designs CCD to be exposed for display scan period Tv or a period integer times as long as Tv. Thus, the detection marks or the like can be completely sensed by CCD without being chipped regardless of the location thereof in the wide screen. This makes it possible for the detection marks or the like to be located close to the target object in the projected image no matter where the target object is located in the wide screen.
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A position detector displays a target on a given plane and adds a standard on the given plane in the vicinity of the target with the location of the standard known. An image of the given plane is formed on an image plane of an image sensor with an image of the standard included, a point in the image of the given plane which is formed at a predetermined position of the image plane corresponding to the point to be detected. An image processor identifies the image of the standard on the image plane to calculate the position of the point to be detected. The standard includes asymmetric pattern. The standard includes a first standard and a second standard sequentially added on the given plane, the difference being calculated accompanied with the plus sign or the minus sign. The image on the given plane is formed by means of a scanning, the image sensor reads out the sensed image upon the termination of at least one period of the scanning. The second standard is added upon the initiation of the scanning after the completion of reading out of the image of the first standard.
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This application claims the benefit of Italian Application No. SV99A000036 filed Nov. 5, 1999 and PCT/EP00/10795 filed Nov. 2, 2000.
BACKGROUND OF THE INVENTION
The invention relates to a damping corrugator roll, comprising an outer toothed surface, whose teeth extend over a certain axial length of the roll, support means allowing rotation about the axis of the roll, and rotary drive means.
The invention particularly relates to a corrugator roll of the above type, provided in combination with an upper corrugator roll, parallel and tangent to said lower roll, both rolls being part of a corrugator unit for paper sheets, in corrugated board fabrication.
As a rule, the upper corrugator roll has a greater diameter and is rotatably driven, but it also has peripheral skirt teeth, whereby it meshes with the teeth of the lower corrugator roll, which runs idle and is rotatably dragged along by the upper corrugator roll.
In prior art machines, a severe problem is the very high level of noise generated by the corrugator unit. This noise is caused by the generation of vibrations and oscillations, mainly in the lower corrugator roll, which, according to current manufacturing trends, is smaller than the upper corrugator roll, hence more exposed to the excitation of vibrations.
There may be different kinds of vibrations, i.e. they may depend on flexures transverse to the axis of rotation, or on torsional flexures, i.e. in the circumferential direction with respect to the axis of the roll. Vibrations also depend of the shape of the corrugator teeth of the two rolls which, in combination with the paper feed, cause the vibratory motion of the roll. Due to the considerable axial lengths of rolls, the vibratory and/or oscillatory effects are particularly felt in the center part of the roll, i.e. far from the support constraints at the ends thereof. Also, in this center part, the vibratory and/or oscillatory effects are relatively out of control and dependent on the features of the processed paper.
Prior art damping means can absorb or damp at least part of the vibrations at the end constraints of the lower corrugator roll, but definitely cannot handle neither systematic nor casual oscillations or vibrations (the latter due to modified features of the paper being processed) at the center part of the corrugator roll. Therefore, a relatively poor damping effect is always obtained, whereby to date a still high level of noise is generated by corrugator units, such that it requires expensive and complex acoustical treatments on machines.
Moreover, vibrations and/or oscillations cause functional problems, such as the need to limit the production rate because the poor vibration dampening causes a loss of attachment between the layers of the corrugated board and a smaller flute width.
SUMMARY OF THE INVENTION
The invention has the object to provide a damped, particularly lower corrugator roll, so that, by simple and relatively inexpensive arrangements, the drawbacks of prior art rolls can be obviated, by effectively damping the generation of vibrations and/or oscillations, hence by drastically reducing the noise effect and the functional drawbacks due to poor damping.
The invention achieves the above objects by providing a corrugator roll as described hereinbefore, comprising:
A cylindrical core which is supported for free rotation at its ends and whereon a toothed peripheral cylindrical jacket is supported in a floatable manner by an interposed or bearing material.
The bearing or interposed material may consist of a fluid, such as a gas, a liquid, a highly viscous liquid or, for instance, having a pasty consistency, or of a solid material having a highly hysteretic elastic behavior.
The characteristics of the gaseous, liquid or pasty fluid shall be such that the friction coefficient of said materials with respect to the surfaces in contact therewith, that is the outer skirt of the core and the inner skirt of the floating jacket, will increase as the relative speed between the floating jacket and the cylindrical core increases.
The interposed or bearing fluids may be provided under pressure, at atmospheric pressure, or in conditions of negative pressure with respect to external atmospheric pressure. This depends on the conditions of use.
It may be also provided that the jacket and the cylindrical core form, e.g. by using rotary sealing heads, a sealed hollow space wherein the interposed material is introduced and replaced from time to time after a predetermined number of operating hours.
Alternatively, the sealed hollow space formed by the tubular cylindrical jacket and by the cylindrical core may have inlets and outlets for automatic feeding of or filling up with the interposed material, in this case fluid, or for generating a continuous or batch circulation of said fluid, which can provide balanced dynamic conditions in the hollow space as regards pressure and quantity of fluid. At the same time, the circulation of fluid ensures a constant renewal thereof, for instance with respect to the maintenance of a predetermined temperature or of a predetermined mixture composition or condition, or of any other parameter that can be affected by the use and restored by service treatments.
Advantageously, the sealing means at the heads of the tubular toothed cylindrical jacket are such that they allow, by using yielding members, the jacket to be moved at least transverse to the core.
The cylindrical jacket has lower weight and inertia values as compared with the central core.
Depending on the length, the length to diameter ratio of the lower roll, i.e. of the jacket of the lower roll is higher than 10. The jacket shall be relatively thin, but anyway have a sufficient thickness to allow paper processing.
As a rule, the diameter to thickness ratio is of 8/1 to 15/1, preferably of about 10/1.
For diameters and lengths commonly used in corrugator machines, the thickness of the jacket may range from 10 to 100 mm, particularly from 20 to 50 mm, preferably from 25 to 35 mm.
The hollow space or chamber, or the difference between the outside diameter of the core and the inside diameter of the jacket is of 0,1 to 5 mm, also depending on the diameter and length of the jacket as well as on the type of interposed material.
The outer jacket can be made of any suitable material, also composite or in two, three or more layers.
For instance, the material to be used can be steel or other metals, preferably after undergoing hardening treatments, such as quenching or coating with hard layers, e.g. made of tungsten carbide, hard chromium or titanium nitrides.
The invention is based on the acknowledgement that, during operation, the vibrations in the floating jacket cause variations in the bearing thickness (thickness of the hollow space between the floating jacket and the cylindrical core), hence in the bearing fluid. Bearing thickness deformations cause variations in the relative speed of the filling or bearing material, hence variations in the friction coefficient, which have the effect of damping the motions and stresses that generate vibratory motions.
The arrangement according to the invention leads to unexpected advantages in combination with bthe toothed corrugator rolls. An effectively damping lower corrugator roll is the most appetizing and required thing in the field. A drastic reduction of the noise generated by vibrations would allow to reduce economic and construction efforts for acoustical treatments. Yet, the floating suspension of the lower corrugator roll does not require to account for the specificity of shapes or profiles of the corrugator teeth, since such floating suspension allows a wide adaptability to the teeth shapes, as regards both noise generation and functional effectiveness of the corrugator unit. More particularly it has to be noted that the teeth of corrugator rolls cooperating with each other are not designed to lead to a homocinetic kind of motion. This means that the way two corrugator rolls cooperate with each other is not similar to the way as two gears cooperate with each other, since the teeth are designed in order to corrugate sheets of paper without damaging the paper. The corrugator rolls are affected not only by vibration modes due their own motion but also by vibrations which are induced by the teeth and the paper being treated. The bearing fluid or material interposed between the core of the roll and the toothed jacket has shown a high speed of reacting to the induced vibrations thus leading to an effective damping of the vibrations which was unexpected in the technical field on the light of the actual knowledge.
Further unexpected advantages consist in the fact that the bering fluid or material leads to a uniform distribution of the pressure exerted by the corrugator roll over its entire length. This effect allows to avoid particular shaping of the corrugator roll with respect to a cylindrical form. Furthermore, the supports at the ends of the corrugator roll are less stressed than in then case of the known corrugator rolls. Thanks to the above advantages also the frequency of regeneration of the corrugator rolls is reduced, lowering costs for the manufacturers and obviating to have a production line stopped for longer time. It has to be noted that corrugator rolls are very large and big so that it is not quite simple to send the rolls back to the manufacturer for regeneration. Also the regeneration treatment is expensive and time consuming.
A particular advantage appears applying the contruction of the corrugator roll according to the present invention in combination with a corrugator unit, particularly for sheets or webs of paper, or similar, of the type comprising at least two rolls having a toothed or corrugated surface and being mutually engaged and pushed against each other by a predetermined pressure or force, the mutual compression between rolls being exerted over the whole axial length of the rolls through mechanical or magnetic means as described in EP 98112227.8.
In this case a cradle made of a series of several wheels or belts. Particular advantages results in a corrugator unit of the above mentioned kind in which one of the at least two corrugator rolls has a smaller diameter than the other roll.
The damping effectiveness obtained by the roll according to the invention also allows to improve the functionality of the corrugator unit, e.g. with reference to the possibility of increasing the corrugated board production rate, without incurring in manufacturing defects, such as gluing defects and/or variations in flute width.
The invention also relates to further improvements, which form the subject of the dependent claims.
The characteristics of the invention and the advantages derived therefrom will appear more clearly from the following description of a non-limiting embodiment, illustrated in the annexed drawings, in which:
DESCRIPTION OF THE DRAWINGS
FIGS. 1 and 2 are a schematic axial sectional view and a schematic transverse sectional view respectively of a roll according to the invention.
FIG. 3 is an axial sectional view of an embodiment of a roll according to the invention.
FIG. 4 is an axial sectional view of the outer toothed cylindrical jacket.
FIG. 5 is an axial sectional view of the sealing heads of the cylindrical jacket.
FIG. 6 is a view of the cylindrical core.
FIG. 7 shows a general corrugator unit with a pair of toothed rolls, an upper and a lower roll.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIGS. 1, 2 and 7 , a corrugator unit comprises a pair of peripherally toothed meshed corrugator rolls 1 and 2 . One corrugator roll, the upper one 1 , has a relatively great diameter and is rotatably supported and driven at its ends. The second corrugator roll, the lower one 2 , has a considerably smaller diameter and is supported in a pressure cradle, composed of belts, pairs of rollers, or else. The lower corrugator roll 2 is pushed with a predetermined force against the upper corrugator roll 1 .
FIGS. 1 and 2 are very schematic views of the construction principle of the lower corrugator roll according to the present invention. This roll consists of a cylindrical core 102 , which has rotary support extensions 202 at its ends, whereby the cylindrical core 102 is mounted for free rotation onto the support frame, for instance of the corrugator unit. The cylindrical core 102 is held inside a cylindrical jacket 302 , whose inside diameter is greater than the outside diameter of the cylindrical core, thereby forming a cylindrical hollow space 402 between said two parts. In principle, the hollow space cannot be closed at the end sides. Further, if the jacket 302 has partial or complete heads 502 through which the extensions 202 for support of the cylindrical core 102 extend, then these heads shall be elastically coupled to the core supporting extensions 202 , i.e. so that the tubular cylindrical jacket 302 can move transverse to the cylindrical core, at least within the limits of the order of magnitude of the vibrations to be damped. This is shown by the elements denoted with numeral 602 .
The hollow space 402 can simply contain air at atmospheric pressure, or at different over- or underpressures, or mixtures of gases, liquid fluids or mixtures of liquid fluids, having different, preferably high viscosity values, or highly viscous, or pasty materials, such as fat, or the like.
Liquid fluids may include water, oil, mixtures of water and oil, plastic polymers in liquid form, and any type of liquid having the physical characteristics fit for the purpose.
Alternatively, the space 402 can be filled with a solid plastic material of the elastic type, particularly having a highly hysteretic elasticity.
The fluid materials held in the hollow space 402 preferably have such characteristics as to generate friction coupling between the jacket 302 and the core 102 , the friction coefficient being such that it increases as the rotation speed difference between the core and the jacket increases.
Then, the tubular jacket 302 rotates freely around the core, substantially floating on an intermediate bearing layer. The jacket is rotatably driven by the upper corrugator roll 1 against which it is pushed, for instance by the belts 8 . The core is also rotatably dragged along by the jacket, by being coupled thereto through the fluid or solid bearing substance. The rotation of the core is necessary for the storage of a sufficient inertia, which would not be possessed by the jacket alone. Inertia is required to ensure that the motion conditions of the jacket are as independent as possible from small variables of the product or operating conditions.
The fluid or other mass provides the translation of the jacket vibrations into local variations of width of the hollow space and hence into local variations of speed or local gradients of speed, which locally generate an increase of friction, hence the absorption of the energy caused by vibrations, whereupon the latter are at least partially damped.
The cylindrical core 102 is generally made of solid steel. The jacket may be made of steel or of any other metal, preferably after undergoing surface hardening treatments, such as quenching or coating with layers of a hard material, e.g. tungsten carbide, hard chromium, etc. and/or titanium nitrides.
The thickness of the jacket varies with its diameter, the latter being subject to restrictions based on the length. Generally, with length to diameter ratios higher than 10, the diameter to thickness ratio of the jacket is of 8:1 to 15:1, particularly of 10:1. For usual roll lengths, thickness may range from 10 to 100 mm, particularly from 20 to 50, especially from 25 to 35 mm.
The hollow space must not be excessively thick. It can have a thickness of 0.1 to 5 mm.
With reference to FIGS. 3 to 5 , a definitely non-limiting construction embodiment of the invention concept is shown.
The cylindrical core 102 , with the extensions 202 thereof, is slipped into a jacket element 302 , which has an inner layer 3 made of a highly hysteretic elastic plastic material. Said material is preshaped to hold the heads 4 for rotatably sealing the jacket, while allowing transverse staggering movements.
Advantageously, the layer 3 at the heads of the jacket 302 may have a recess for housing the sealing heads 4 , which are properly positioned and locked therein with the desired sealing effect. These heads have no support function on the jacket 302 but are only used to contain substances, fluids or liquids held in the hollow space.
The inner plastic layer 3 can have the function of directly damping vibrations.
In combination with said plastic layer and the core 102 , a hollow space may be provided which is filled with air or another fluid, particularly with a viscous liquid.
In this case, the elastic or viscous vibration absorption behavior may be calibrated by combining two or more layers for bearing the jacket 302 .
The layer 3 may also be made of metal while the hollow space alone may be filled with the bearing fluid.
As shown in the figures, and particularly in FIGS. 3 and 5, the heads 4 may have in this case inlets and/or outlets 104 for the bearing and/or interposed fluid. These can be simply used for occasionally filling and/or topping up the hollow space 402 with the bearing fluid. Alternatively, the fluid may be made to permanently circulate between a storage tank and the hollow space, thereby allowing adjustment of the physical and/or composition parameters of the fluid, e.g. by adjusting temperature when the roll is in use.
Obviously, the illustrated constructions are not intended to restrict the previously disclosed principle of the invention and can be extended to further types of rolls, both for board production industry and for other sectors, having equal problems.
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A damping corrugator roll comprises an outer toothed surface, whose teeth extend over a certain axial length of the roll ( 2 ), support means ( 202 ) allowing rotation about the axis of the roll, and rotary drive means ( 1 ), characterized in that it comprises a cylindrical core which is supported for free rotation at its ends, and whereon a toothed peripheral cylindrical jacket is supported by and interposed or bearing material.
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RELATED APPLICATIONS
[0001] This application is a continuation-in-part of co-pending U.S. patent application Ser. No. 387,909, filed on Jul. 31, 1989 and Ser. No. 444,189 filed on Nov. 30, 1989. The present invention relates to a surgical suture guide used to control the dimension and/or shape of a suture line placed during surgical repair of an organ or body part. In particular, the present invention relates to a combination of a flexible suture guide releasably attached to a rigid holder for controlling the spacing and placement of surgical sutures.
BACKGROUND OF THE INVENTION
[0002] During surgical repair of an organ or other body part, the surgeon typically makes an incision to open the organ. Upon closure of the surgical wound, sutures are placed in the various layers of tissue to draw the two edges of the wound together so that the healing process can reform a smooth and competent surface. However, sutures often tear through the tissue if they are subjected to stress, thus damaging the surgical closure of the wound. It would be desirable in many instances to have a means for lending permanent support to strengthen and support the wall of the organ into which the surgical incision has been placed. Alternatively, in many instances it would be preferred to have a biodegradable suture guide.
[0003] In many cases, the incision is not a straight line, but is shaped to conform to an anatomical requirement, making it difficult for the surgeon to balance the tension on the sutures to form the desired shape. In a number of instances the suture line is substantially curvilinear and it is of utmost importance that the suture line maintain a predetermined dimension. For example, when two blood vessels, or other vessels, such as intestines, are sutured together, the need exists for some means of preventing the suture line from constricting the vessel so as to create a potential point of blockage. Similar problems arise during bowel and bronchial resection. As another example, when the surgeon is reducing the size of a stomach by surgical means, the need exists for a means to assure that the reshaped organ will have a particular circumferential dimension and that the pleats used to reduce the size of the organ are evenly distributed so as to avoid formation of areas of reduced flexibility along the suture line. In other situations, such as in cosmetic surgery, the surgeon may desire to assure that the suture line is limited to a predetermined length.
[0004] In all of these situations, it is desirable to use a suture guide to aid the surgeon in achieving the desired dimension of the surgical closure and/or to rigidly support the area where the sutures are placed, thus avoiding the danger that the sutures will tear through the tissue or that the suture line will act like a draw string and undesirably bunch up the tissue.
[0005] These problems are particularly acute in the surgical procedure known as annuloplasty wherein any of a number of types of prostheses have been used in surgical correction of deformed mitral or bicuspid heart valves.
[0006] Diseases and certain natural defects to heart valves can impair the functioning of the cusps of the valves in preventing regurgitation of blood from the ventricle into the atrium when the ventricle contracts. For example, rheumatic fever and bacterial inflammations of the heart tissue can distort or dilate the valvular annulus, thus resulting in displacement of the cusps away from the center of the valve and causing leakage of blood during ventricle contraction.
[0007] Two techniques, generally known as annuloplasty, are- used to reshape the distended and/or deformed valve annulus. In the technique known as “plication,” the circumference of the valve annulus is reduced by implanting a rigid or semi-rigid prosthetic ring of reduced circumference about the base of the annulus while the annulus is pleated to reduce its circumference to that of the ring. In the technique known as “reconstruction”, the circumference of the annulus is not reduced, but the annulus is restructured into an elongate shape. To accomplish this goal, a rigid or semi-rigid ring having the same circumference as the annulus but in an elongate or elliptical shape is surgically implanted about the base of the valve. Both plication and restructuring are intended to eliminate the gap in the closure of the distended valve by bringing back together the tips of the valve cusps.
[0008] Many different types of prostheses have been developed for use in annuloplasty surgery. In general, prostheses are annular or partially annular shaped members that fit about the base of the valve annulus. Initially the prostheses were designed as rigid frame members, or “rings”, of metallic or other rigid materials that flex little, if at all, during the normal opening and closing of the valve. Since a normal heart valve annulus continuously flexes during the cardiac cycle, a rigid ring prosthesis interferes with this movement and thereby restricts movement of the valve itself. Sutures used to implant rigid ring prostheses consequently undergo stresses sufficient to tear the sutures loose. Examples of rigid annuloplasty ring prostheses are disclosed in U.S. Pat. No. 3,656,185, issued to Carpentier on Apr. 18, 1972; and U.S. Pat. No. 4,164,046, issued to Cooley on Aug. 14, 1979.
[0009] Others have suggested the use of completely flexible annuloplasty ring prostheses. Examples of completely flexible ring prostheses are disclosed in U.S. Pat. No. 4,290,151, issued to Massana on Sep. 22, 1981, and are discussed in the articles of Carlos D. Duran and Jose Luis M. Ubago, “Clinical and Hemodymanic Performance of a Totally Flexible Prosthetic Ring for Atrioventricular Valve Reconstruction”, 5 Annals of Thoracic Surgery , (No. 5), 458-463, (November 1976) and M. Puig Massana et al, “Conservative Surgery of the Mitral Valve Annuloplasty on a New Adjustable Ring”, Cardiovascular Surgery 1980, 30-37, (1981).
[0010] Flexible prostheses generally include an inner support member formed from a flexible material. This support member is wrapped in woven, biocompatible cloth material. Realignment of the valve cusps during opening and closing of the valve is obtained by the proper suturing of the ring about the valve annulus. However, completely flexible ring prostheses provide almost no support to the suture area during the precarious implant procedure. Even though the surgeon attempts to evenly distribute the sutures along the periphery of the valvular annulus, during implant the drawstring effect of the sutures tends to bunch the material covering the flexible ring so that the sutures also bunch together at localized areas around the ring. This phenomenon, known as multiple plications in the heart valve annulus, causes rigid areas around the annulus. Thus, the flexible ring actually ends by imparting areas of rigidity and thereby distorts the valve annulus during the opening and closing of the valve despite the desired reduction in circumference of the valvular annulus.
[0011] To overcome some of the drawbacks of rigid ring prostheses, still further types of annuloplasty prostheses have been designed to allow for adjustment of the ring circumference, either by the surgeon during implant, or automatically as the implanted. ring moves during the opening and closing of the valve. This type of adjustable prosthesis is typically designed in combination with a rigid, or at least partially rigid, frame.
[0012] An example of a self adjusting ring prosthesis is taught in U.S. Pat. No. 4,489,446, issued to Reed on Dec. 25, 1984. To provide for self adjustment of the prosthetic annul-us, two reciprocating rigid metal pieces form the frame. U.S. Pat. No. 4,602,911, issued to Ahmadi et al. and U.S. Pat. No. 4,042,979, issued to Angell on Aug. 23, 1977, provide further adjustable ring protheses having a mechanism for adjusting the circumference of the ring. But due to rigidity of the frame members, the self-adjusting prostheses do not overcome many of the disadvantages of other types of rigid ring prostheses.
[0013] U.S. Pat. No. 4,055,861, issued to Carpentier on Nov. 1, 1977, teaches an annuloplasty ring prosthesis having a flexibility between the completely flexible rings discussed above and the various types of rigid ring. The ring of Carpentier is deformable to an equal degree and simultaneously in all directions and preferably has the elasticity of an annular bundle of 2 to 8 turns of a cylindrical bristle of poly(ethylene terephthalate).
[0014] While rigid and semi-rigid annuloplasty rings eliminate the bunching caused by flexible rings, the restrictive nature of such rings is generally detrimental to the valve's ability to open and close normally. It thus remains an object of the invention to provide a surgical means for reshaping a deformed or dilated heart valve annulus having none of the above described drawbacks associated with known annuloplasty ring prostheses.
[0015] For use in annuloplasty of heart valves, as in other applications, it is desirable that a suture guide be entirely flexible, light weight, and compliant while having sufficient strength to withstand stress placed upon the sutures sewn through and around it. However, an entirely flexible suture guide cannot prevent bunching of the tissue in the draw-string effect described above and thus cannot assure that the suture line and the tissue into which it is placed will maintain any desired dimension, for example, a desired circumference. Therefore the need exists for a means of temporarily providing rigidity and fixed dimension to the suture guide during the surgery, but rendering the suture-guide freely flexible once the surgery has been accomplished.
DESCRIPTION OF THE DRAWINGS
[0016] The present invention may be better understood and the advantages will become apparent to those skilled in the art by reference to the accompanying drawings, wherein like reference numerals refer to like elements in the several figures, and wherein:
[0017] [0017]FIG. 1 is a perspective exploded view of a flexible suture guide mounted on a rigid holder assembly in accordance with an embodiment of the invention
[0018] [0018]FIG. 1A is a top view in partial cross-section of a length of a flexible suture guide in accordance with the present invention.
[0019] [0019]FIG. 1B is a top view in partial cross-section of the flexible suture guide of the present invention sutured into a ring configuration.
[0020] [0020]FIG. 2 is an exploded view of the guide mount portion and lower part of the handle portion of the holder assembly of FIG. 1 without the suture guide.
[0021] [0021]FIG. 3 is a perspective view of a flexible suture guide of the present invention mounted on the assembled guide mount and lower handle portions seen in FIG. 2.
[0022] [0022]FIG. 4 is a cross-sectional view of the assembled guide mount and lower handle portions of FIG. 3 along line 4 - 4 .
[0023] [0023]FIG. 5 is a top view of the guide mount seen in FIG. 3 with a flexible suture guide tautly secured thereto.
[0024] [0024]FIG. 6 is a perspective view of a guide mount in accordance with another embodiment of the invention.
[0025] [0025]FIG. 7 is a cross-sectional view of a suture guide having a lenticular cross-sectional shape in accordance with another embodiment of the invention.
[0026] [0026]FIG. 8 is a side perspective sectional view of a handle assembly in accordance with another embodiment of the invention.
[0027] [0027]FIG. 9 is a bottom view of the handle extension of FIG. 8.
[0028] [0028]FIG. 10 is a top view of the housing of FIG. 8.
[0029] [0029]FIG. 11 is a perspective view of a suture guide holder in accordance with another embodiment of the invention.
[0030] [0030]FIG. 12 is an exploded view of the guide mount portion and lower handle portion of the suture guide holder of FIG. 11.
[0031] [0031]FIG. 13 is a top view of the guide mount portion of the suture guide holder of FIG. 11.
[0032] [0032]FIG. 14 is a perspective view of a linear suture guide holder in accordance with another embodiment of the invention.
[0033] [0033]FIG. 15 is a perspective view of the suture guide holder of FIG. 14 with a suture guide attached.
[0034] [0034]FIG. 16 is a perspective view of a circular suture guide holder in accordance with another embodiment of the invention.
[0035] [0035]FIG. 17 is a perspective view of the suture guide holder of FIG. 16 with a suture guide attached.
[0036] [0036]FIG. 18 is a cross-sectional view of the suture guide and holder of FIG. 17 taken along line 18 - 18 .
SUMMARY OF THE INVENTION
[0037] The present invention overcomes the above discussed disadvantages by providing an assembly for holding a substantially flexible suture guide in a substantially taut position for placing a suture line having a predetermined dimension. When attached to the holder assembly, the flexible suture guide assumes a shape or geometry, such as a circumference, that conforms to the shape or geometry of that portion of the body organ or vessel that is being sutured. The holder assembly can be formed to hold the suture guide in any desired shape, whether straight, curvilinear, or a combination of the two and the suture guide can be either biodegradable or permanently implantable. Thus the surgeon undertaking reconstructive surgery is aided in achieving a suture line of any desired shape, geometry and/or dimension.
[0038] The assembly includes a holder portion having a surface against which the suture guide is positioned and held tautly in a fixed shape, geometry and/or dimension. More particularly, the holder assembly includes a body having an outwardly facing surface, generally flat, against which the suture guide is tautly positioned so that the suture guide assumes the shape, geometry and/or dimension desired for the suture line. Preferably, this surface is formed with at least one depression for receiving a portion of the suture guide. The assembly further includes a detachable handle and a mechanism for releasably binding the suture guide to the surface.
[0039] The flexible suture guide used with the assembly of the invention comprises a generally elongated flexible body element having an internal flexible rib encased within a biocompatible covering, such as a woven cloth material. The suture guide can be formed of either biodegradable or non-biodegradable materials depending upon whether its purpose is to serve as a permanent support to prevent tearing out of the sutures placed through it or whether the suture-supporting function is to be a temporary one. In addition to its function as a post-surgical support for sutures, during surgery when used in combination with the holder disclosed herein, the suture guide serves as a rigid support and template by which the surgeon controls the length of the finished suture line. For instance, if the task is to suture together two ends of a bowel from which a section has been removed, the combination of suture guide and holder assure that the circumference of the surgical jointure is substantially similar to the circumference of the nearby regions of the colon, rather than smaller or larger.
[0040] Therefore, the holder device is designed to lend a temporary rigidity or tautness to the suture guide while lending to it a shape selected to facilitate the suturing task. For instance, when the task is to place a line of sutures around the circumference of a curvilinear surface, the holder is designed to fit around at least a portion of the circumference while holding the suture guide against the said circumference to aid the surgeon in making a surgical jointure that does not distort the said circumference.
[0041] In use, the suture guide is releasably retained against the outwardly facing body surface by a means for releasable attachment, for example one or more threads, pieces of Velcro™, and the like, placed so that the suture guide lies along and temporarily substantially assumes the shape of the body. The means for attachment may also be a biodegradable adhesive having the capacity to firmly attach the suture guide to the holder body for sufficient time to complete the surgery, but having the capacity to dissolve or be dissolved once the suture line has been placed. In one embodiment, the thread attaches the suture guide to the body surface at least at two points, for example at its extreme ends, by passing at least partially through the suture guide and about the body, i.e., by means of an in and out stitch or stitches.
[0042] The means for releasable attachment of the suture guide to the body must be such that the suture guide can be released from the body once the suture line has been placed by the surgeon without disturbing the sutures sufficiently to cause dislocation or tearing of the sutures through the tissue. For example, if the means for releasable attachment is one or more threads, a portion of the thread(s) affixing the suture guide to the body can be positioned to be cut by scissors, or the like, to freely release the suture guide from the body. When the thread or threads are cut or otherwise ruptured, the suture guide is freely released from the body.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0043] The present invention is directed to a holder assembly for holding a substantially flexible, implantable suture guide in a substantially taut position for suturing along a suture line having a desired shape or dimension, such as the desired circumference to which an enlarged heart valve annulus is to be reduced by the formation of pleats about the base of the valve annulus. The suture guide of the invention is formed from a freely flexible rib encased within a woven cloth covering. In use, the flexible suture guide of the invention is held taut by the holder assembly and in a configuration determined by the shape of the holder assembly while the surgeon uses the support provided by the taut suture guide to evenly place the sutures and to draw the tissue by means of the sutures passed through the suture guide into a suture line having a shape substantially similar to that of the suture guide and holder. For example, for use in annuloplasty, the holder assembly can be C-shaped so that the suture guide temporarily affixed thereto assumes a C-shaped configuration. The suture guide can then be sutured to the base of a heart valve annulus so as to restrict the circumference of a dilated and/or deformed valve annulus to a more normal one. When the suture guide is released from the holder, it will assume any shape that that portion of the body organ or vessel assumes in accordance with the dynamic function of the organ or vessel.
[0044] Generally the guide mount assembly includes a guide support formed with a shape similar to that of the desired suture line, as in the above example wherein the holder assembly is in the general shape of the valve annulus about which the suture guide is to be surgically placed to assist in holding pleats in the walls of the annulus. The suture guide is mounted along at least a portion of this guide support, for example along a straight or a curved portion.
[0045] The holder assembly allows the surgeon to properly position the suture guide while the suture guide is used to draw the sutures and associated tissue into the desired configuration during the suturing process. The freely flexible suture guide is given temporary rigidity during surgery by the detachable holder assembly, thus lending precision to the surgeon in controlling the placement and location of the stitches in the suture line. In an annuloplasty, for example, the potential for forming multiple plications as the circumference of the valve annulus is adjusted is thus greatly reduced.
[0046] Referring now to FIG. 1A, the suture guide 10 is an elongate, flexible member of a predetermined dimension. Due to its flexibility, the length of suture guide 10 can be manipulated to assume any desired shape, ie., circular, C-shaped, straight, curvilinear or a combination of curvilinear and straight segments. In FIG. 1B, suture guide 10 is shown as shaped into a ring by suturing the two ends together with sutures 11 . As shown in FIG. 1A, suture guide 10 comprises a substantially flexible inner rib 14 encased within covering 16 .
[0047] Rib 14 comprises a flat, rod-like or tubular piece of biocompatible resilient, flexible material, such as mylar or silicone rubber. Rib 14 can also contain a substance opaque to x-rays, for example, about 10 to 15 weight percent, preferably 13 weight percent, of barium sulfate so that the location of the suture guide can be determined in post-operative x-rays. The outer covering 16 is formed from any biocompatible material having sufficient strength to serve as an anchor to sutures without tearing and sufficient flexibility to be formed into a tight covering for rib 14 without restricting flexibility of suture guide 10 . Preferably, the outer covering 16 is a woven cloth having a nap to encourage tissue ingrowth, for example a dacron velour. This outer covering 16 is tightly wrapped and sewn about frame 14 so as to completely encase it. The thickness of the outer cloth 16 is sufficient to allow the surgeon to pass a suture therethrough.
[0048] [0048]FIG. 1 shows an exploded view of one embodiment of a holder assembly to which a suture guide is mounted, as seen generally at 12 and 10 respectively. The holder assembly 12 includes a guide mount assembly 18 and handle assembly 40 comprising a handle 42 and housing 44 .
[0049] [0049]FIGS. 2 through 5 illustrate in greater detail the guide mount assembly 18 and how the suture guide 10 is mounted thereon. Guide mount assembly 18 includes a guide support 20 . For illustrative purposes, the suture guide assembly 18 here shown is one intended for use in plication of a distended heart valve annulus. Therefore facing edge of guide support 20 is generally C-shaped or annular, having a shape and circumferential dimension similar to that the surgeon desires to achieve in the human heart annulus by means of annuloplasty surgery. More particularly, support 20 is generally lenticular, having a C-shaped portion 28 , with its ends connected by a straight side 30 .
[0050] The suture guide 10 is fitted into a groove or trough 32 located about the curved C-shaped portion 28 of the guide support 20 Trough 32 is dimensioned to receive a portion of the suture guide 10 , as best seen in FIG. 4. The positioning of the suture guide 10 within the trough 32 conforms guide 10 to the shape of the guide support 20 while exposing a substantial portion of the covering 16 outside of the trough 32 to allow the surgeon to pass a suture therethrough.
[0051] In the embodiment shown in FIGS. 2 - 5 , the guide mount assembly 18 also includes a central support hub 22 to which the guide support 20 is attached by a multiplicity of integrally formed spokes, preferably three, one of which is seen at 24 . The arrangement of mount assembly 18 including, in this instance, a curved guide support 20 with hub 22 and spokes 24 , allows the surgeon to visually observe the heart valve during the suturing process. Central support hub 22 is formed with an annular groove 36 . This groove 36 is formed proximate that end 34 of hub 22 opposite guide support 20 , and defines a post member 38 . That portion of hub 22 remaining on the side of the groove 36 opposite the guide support 20 , and hub end 34 , includes an inwardly tapering peripheral surface, as seen generally at 35 . The hub 22 also includes an open bore 37 through which is fitted a cylindrical plug 39 . The plug 39 is dimensioned to extend out from both sides of the bore 37 . The purpose of tapered surface 35 , and the plug 39 will be described hereinafter.
[0052] As is further seen in FIG. 1, the handle assembly 40 includes an elongated handle 42 having end 54 mounted to housing 44 . While housing 44 may be integrally formed at the end 54 of the post 42 , preferably end 54 is formed with outwardly facing threads that threadably mate with threads formed along a surface of an opening 59 formed in the top of the housing 44 . The opposite end of post 42 is formed with an external etched surface 52 to assist the surgeon in gripping post 42 . In another embodiment, end 54 of post 42 and opening 59 of housing 44 can be formed so that end 54 can be press fit into opening 59 .
[0053] Housing 44 is a thimble-shaped structure having a circular wall 60 defining a cavity 46 . As seen better in FIG. 4, cavity 46 is open at one side, seen generally as opening 45 . The inner surface of the circular wall 60 inwardly converges a short distance from the opening 45 . The cavity 46 is generally wide enough at the open side 45 to snugly receive hub 22 , but the plug 39 extends sufficiently outward from hub 22 to prevent passage through open side 45 into cavity 46 . Wall 60 is formed with two J-shaped notches, seen at 48 and 49 in FIGS. 2 and 3. These J-shaped notches 48 and 49 are formed and positioned to respectively receive the ends of the plug 39 extending outward from the hub 22 . The shape of the notches 48 and 49 defines a landing 50 between the long and short legs of each notch.
[0054] Handle assembly 40 is coupled to the guide mount assembly 18 by inserting end 34 of the hub 22 into the cavity 46 , with one of the outwardly extending ends of the plug 39 passing through a respective one of the J-shaped notches 48 and 49 . The tapered surface 35 of the hub 22 engages the inwardly tapering surface of the wall 60 . This causes a slight compression of the hub end 34 , resulting in a spring force. The spring force acts to restrain the movement of the outwardly extending ends of the plug 39 through the larger legs of the J-shaped notches 48 and 49 . Additional exertion moves the ends of plug 39 through the larger legs of J-shaped notches 48 and 49 , with rotation of handle 40 passing the outward ends of plug 39 across the landings 50 and into the smaller leg of the J-shaped notches 48 and 49 .
[0055] The spring force established by the slight compression of the hub end 34 maintains the coupling between housing 44 and guide mount assembly 18 . The handle 40 is decoupled from the guide mount assembly 18 by reversing the described procedure.
[0056] One embodiment of the means for releasably attaching suture guide 10 to guide support 20 of guide mount assembly 18 is seen in FIG. 5. Guide support 20 is formed with two apertures 66 and 68 extending through guide support 20 and communicating with groove 32 . The exact positioning of apertures 66 and 68 is not critical. As illustrated, apertures 66 and 68 are formed along the straight portion of guide support 20 , at a location proximate two of the spokes 24 .
[0057] One end 71 of a cord or suture thread 70 is passed through one of the apertures, as illustrated hole 66 , and tied off on guide support 20 . The other end 73 of suture 70 is passed through the body of suture guide 10 from one end to the other. This end 73 is then passed first through hole 68 and then through and tied off at hole 66 . After suture guide 10 is sutured into position during surgery, ire., about the valve annulus, that portion of the suture 70 between apertures 66 and 68 is snipped or cut in two. Suture 70 passes-out of suture guide 10 by withdrawing the handle assembly 12 .
[0058] In accordance with another embodiment (not shown), the first end 71 is tied off at hole 66 , with the second end 73 passed first through one end of the suture guide 10 , and then brought back across and passed through the other end of suture guide 10 , through hole 68 and again tied off at hole 66 . Removal of suture 70 is accomplished by snipping the suture in two at any point between the two holes and withdrawing it.
[0059] An alternative embodiment of the guide mount assembly so as seen in FIG. 6 includes a guide support 82 having an open C-shaped side 84 but no straight side joining the ends of the C. Except for the stated difference in shape of the guide support 82 , guide mount assembly 80 in FIG. 6 includes elements similar to those described for the suture guide of FIG. 5 (as is indicated by the prime of the previously provided element number), and will be described in no further detail herein. In this embodiment of guide mount assembly 80 , the means for releasably attaching the suture guide to the guide support is a suture (not shown) positioned by tying off as described above across an open space between holes 68 ′ and 66 ′ (not shown).
[0060] In a preferred embodiment of the invention, the handle assembly 40 is tethered to the guide mount assembly 18 . As seen in FIG. 1, this tethering is performed by connecting one end of a lanyard, seen generally at 100 , to the handle assembly 40 and the other end of the lanyard 100 to the guide support 20 , for instance to one of spokes 24 . Lanyard 100 allows a surgeon to detach the handle assembly 40 from the guide support 20 during the suturing procedure to get a clearer view of the surgical site. By tethering handle 40 to the guide mount assembly 18 , the risk of the surgeon leaving the guide support 20 in the patient after completion of the surgical procedure is greatly reduced. Lanyard 100 also allows the surgeon to easily remove the guide support 20 after the handle has been detached.
[0061] In a still further preferred embodiment, a handle assembly 40 is modified to house a spool of suture or string that acts like a tether for the guide mount assembly. The tether is attached at opposite ends to the handle assembly and the guide mount assembly respectively and automatically spools out of the handle assembly when the handle is disconnected from the guide mount assembly.
[0062] This preferred embodiment is better seen in the several FIGS. 8 through 10. The lower portion of a handle assembly in accordance with this embodiment is seen in FIG. 8 at 90 . Handle assembly 90 includes a housing 92 , a handle extension 94 , and a handle post 96 .
[0063] Housing 92 includes a pair of opposing J-shaped notches 98 and 99 that function similarly to the J-shaped notches 48 and 49 described above. The handle extension 94 is fastened to the lower end of the handle post 96 in any suitable manner. As shown, the handle extension 94 includes at one end a bore 102 for receiving the lower end 104 of the handle post 96 . End 104 of the handle post may be held in bore 102 by welding, stamping, or by providing the respective members with interlocking threaded surfaces. Accordingly, neither of these structures of the handle assembly 90 will be discussed in any greater detail.
[0064] The main distinction to the previously described embodiment is that the handle assembly 90 is formed to carry a spool of suture, seen generally at 106 . This suture spool 106 is housed in a bore 112 formed in the handle extension 94 . Handle extension 94 and housing 92 are formed to releasably fit together. Handle extension 94 and housing 92 include mating collars 108 and 110 , respectively. Collar 108 is formed with a groove 114 that receives a tongue 116 extending upward from collar 110 . Tongue 116 is formed with a central aperture 122 , and two opposing cut-aways 118 and 120 that extend out in opposite directions from this aperture 122 .
[0065] Each of the collars 108 and 110 possesses four apertures. Apertures 126 - 129 of collar 108 align with apertures 130 - 133 of collar 110 when the handle extension 94 and housing 92 are fitted together.
[0066] Suture spool 106 comprises a length of suture wound into a cylindrical configuration along lower end 104 of handle post 96 , which fits into bore 112 . The opposite ends of this suture length are tied to the tongue 116 and the handle extension 94 . One end of the suture is drawn through the central aperture of 122 and tied to tongue 116 , as seen at 115 . The opposite end of the suture is drawn through an opening 124 extending from the bore 112 through the handle extension 94 and is tied around the handle extension 94 , as seen at 117 . It should be noted that for the purpose of this invention, the meaning of the term “suture” shall include any cord, string or filamentous material useful for tethering the housing 92 to the handle extension 94 .
[0067] Handle extension 94 and housing 92 are fitted together by placing the tongue 116 into the groove 114 . Sutures are run through aligned apertures to hold the handle extension 94 and housing 92 together. For example, one suture 134 is passed through apertures 126 and 127 of handle extension 94 and apertures 130 and 131 of housing 92 , while a second suture 136 is passed through apertures 128 and 129 of handle extension 94 and apertures 132 and 133 of housing 92 .
[0068] The handle assembly 90 of this embodiment is coupled to the guide mount assembly 18 as stated above. The handle post 96 is removed from the housing 92 by cutting the sutures 134 and 136 and pulling the handle extension 94 away from the housing 92 . Pulling away the handle post 96 unravels the suture spool 106 . After the suture guide is-sutured into position along the suture line, i.e., about a heart valve annulus, the suture(s) holding the guide mount assembly to the suture guide is cut. The guide mount assembly is then removed by pulling on the handle post 96 .
[0069] In another embodiment of the invention, shown in FIGS. 11 - 13 , handle assembly 140 is also modified to house a spool of suture or string that acts like a tether for the guide mount assembly 142 . Referring to FIG. 11, handle assembly 140 , includes housing 144 , handle post 146 , and an enlarged handle portion 148 . Handle post 146 is preferably made of a malleable metal or other material that allows the surgeon to bend the handle to the desired angle while using the suture guide holder assembly. The enlarged handle portion 148 allows the surgeon to grip the handle more easily and also makes it easier for the surgeon to maneuver the suture guide holder into the surgery site. Housing 144 is releasably attached to guide mount 150 as will be described in more detail with reference to FIG. 12. Suture guide 152 is releasably attached to guide mount 150 by threads or sutures (not shown) in a manner which will be described with reference to FIG. 13.
[0070] Referring to FIG. 12, housing 144 includes bore 154 for receiving handle post 146 . The end of handle post 146 may be held in bore 154 by a press fit or friction fit, by welding, or by providing the respective members with interlocking threaded surfaces. Housing 144 also includes a pair of opposing slots 156 for receiving dog ears 158 of the suture spool 160 . Suture spool 160 includes a length of suture or thread 162 wound into a cylindrical configuration along spindle post 164 . One end of the suture 162 is tied to an aperture (not shown) in upper end 166 of suture spool 160 . The other end of suture 162 is affixed to hub 168 of guide mount 150 . Specifically, suture 162 passes down through aperture 170 , up through aperture 172 , and is tied off at aperture 112 . The lower end of spindle post 164 has a pair of opposing notches 174 formed therein which are sized to be received by bore 176 of hub 168 . Spindle post 164 , therefore, is press fit or friction fit into bore 176 .
[0071] Suture spool 160 is housed within the interior cavity (not shown) of housing 144 and is held in place when dog ears 158 snap fit into opposing slots 156 . Housing 144 with suture spool 160 in place is then releasably attached to guide mount 150 by sutures or threads 178 and 180 shown in FIG. 11. Suture 180 passes through a pair of apertures 182 in housing 144 and a pair of apertures 184 in guide mount 150 as illustrated by dotted lines 186 in FIG. 12. Suture 178 passes through a pair of apertures 188 in housing 144 and a pair of apertures 190 in guide mount 150 as shown by dotted lines 192 in FIG. 12.
[0072] Once the suture guide and guide mount assembly has been placed at the surgery site, the surgeon can remove the handle if desired by cutting sutures or threads 178 and 180 at the location of the cutting guides 194 and 196 shown in FIGS. 11 and 12. Cutting guides 194 and 196 consist of a raised platform with a shallow groove 195 formed therein through which the suture passes and a deeper groove 197 formed in the platform perpendicular to the shallow groove through which scissors or other cutting tools can be inserted to clip or cut the suture at that location. When the sutures are cut and the handle is removed, spool 160 remains within housing 144 and suture 162 remains attached to hub 168 . As the handle is pulled away from the guide mount, the suture or thread spools off spindle post 164 thereby providing a tether for removal of the guide mount after the suture guide has been detached from the guide mount and the surgery has been completed.
[0073] Referring to FIG. 13, suture guide 152 is releasably attached to guide mount 150 by sutures or threads 198 , 200 and 202 . Suture 198 is tied off at aperture 204 and then passes through one end of the suture guide and up through aperture 206 over cutting guide 208 down through aperture 206 again, through suture guide 152 , through aperture 209 , then up through aperture 210 where the other end of suture 198 is tied off. Suture 200 is at one end tied off through aperture 210 and then passes under the guide mount 150 through aperture 211 , through suture guide 152 and up through aperture 212 , across cutting guide 214 and back down through aperture 212 . Suture 200 then passes through suture guide 152 again, through aperture 215 and up through aperture 216 where it is tied off. Finally, suture 202 is tied off at one end at aperture 216 and passes under suture guide 150 through aperture 217 , through suture guide 152 , up through aperture 218 , across cutting guide 220 , down through aperture 218 again where it passes through suture guide 152 and up through aperture 222 where it is tied off.
[0074] Apertures 224 and 226 disposed in guide mount 150 at opposite ends of the suture guide 152 are used to temporarily attach each end of suture guide 152 to each end of the guide mount 150 to hold the suture guide in place during the process of threading sutures 198 , 200 and 202 through the apertures of the guide mount and the suture guide. Once the threading of sutures 198 , 200 and 202 is complete, the sutures at 224 and 226 are then removed. The sutures at 224 and 226 are shown for illustration purposes in FIG. 11 at 223 and 225 .
[0075] Referring to FIG. 13, cutting guides 208 , 214 and 220 consist of a raised platform with a shallow groove 228 formed therein through which the suture passes and a deeper groove 230 formed in the platform perpendicular to the shallow groove through which a cutting tool may pass in order to cut the suture at the location lying over the deeper groove. The deeper groove is closed at one end by a stop 232 so that the tip of the cutting tool or scissors cannot pass beyond that point. This stop prevents the cutting tool from dipping down into the open space 234 between the spokes of guide mount 150 and accidentally cutting the tissue of the patient.
[0076] When the surgeon is ready to release the suture guide from the suture guide mount 150 he merely snips the sutures 198 , 200 and 202 by passing the cutting tool into the cutting groove of the cutting guides. When the sutures have been snipped at all three locations, the guide mount can be retrieved by pulling on the tether or otherwise removing it and sutures 198 , 200 and 202 are removed with the guide mount 150 since they are tied off on the guide mount.
[0077] Referring to FIGS. 14 through 18, there are shown two additional embodiments of suture guide holders for holding a suture guide. FIGS. 14 and 15 illustrate a linear suture guide holder for placing a linear suture guide. FIGS. 16, 17 and 18 illustrate a circular or ring-shaped suture guide holder for placing a circular suture guide.
[0078] Referring to FIG. 14, the linear suture guide holder has a detachable handle 240 of the type shown in FIG. 2 and linear-shaped guide mount 242 . However, the handle embodiment with the tether illustrated in FIGS. 8 and 12 could also be used. Guide mount 242 has a linear groove or trough 244 into which suture guide 246 is fitted as shown in FIG. 15. Apertures 248 formed in guide mount 242 are used to suture the suture guide to the guide mount as shown in FIG. 15. Guide mount 242 also includes cutting guides 252 and 254 at each end of the guide mount.
[0079] Suture guide 246 is tautly secured to the linear guide mount 242 by suture 250 . One end of suture 250 is tied off at aperture 248 a , passes through suture guide 246 up through aperture 248 b cross cutting guide 252 down through aperture 248 c through suture guide 246 up through aperture 248 d where it is tied to a second length of suture 256 . Suture 256 is threaded down through aperture 248 e through suture guide 246 up through aperture 248 f across cutting guide 254 down through aperture 248 g through suture guide 246 and up through aperture 248 h where it is tied off. Thus, as in previous embodiments, when the surgeon is ready to release the suture guide from the suture guide holder, he merely inserts the cutting tool in the cutting grooves 252 and 254 and cuts sutures 250 and 256 at that location. Suture 250 and 256 are then removed with the suture guide mount 242 . The linear suture guide shown in FIGS. 14 and 15 would be used for any surgical procedure in which the incision is a substantially straight line. The suture guide mount 242 can be any desired length and the suture guide 246 can extend the full length of the suture guide mount 242 as shown in FIG. 15 or could be of a shorter length and sutured to just a portion of suture guide mount 242 . If the surgeon desires a suture guide with a hook or curved end, the suture guide could extend around the edge of suture guide mount 242 to provide one or two curved or hooked ends.
[0080] Referring to FIG. 16, there is shown a circular suture guide holder which would be useful for suturing two blood vessels or other vessels, such as intestines, together. It would also be useful for bowel and bronchial resection. The suture guide holder has a handle 260 which in this embodiment is not shown to be detachable. However, any of the various handle embodiments illustrated previously could be utilized, including the tethering concepts. The suture guide mount 258 is ring shaped with a groove or trough 260 formed on the interior cylindrical surface of the ring. The groove or trough 260 is shaped to receive a circular suture guide 261 as shown in FIG. 17. Suture guide mount 258 has a plurality of apertures 262 evenly spaced about its circumference for use in suturing the suture guide 261 to the suture guide holder as shown in FIG. 17. Suture 264 is threaded through the apertures and through the suture ring in a manner similar to that described with reference to FIGS. 14 and 15 and will not be further be described in connection with this embodiment. Suture 264 can be clipped at two locations such as at 266 and 268 in order release the suture guide from the suture guide holder. Alternatively, cutting guides can be provided as shown in the embodiments previously described and illustrated.
[0081] [0081]FIG. 18 shows a cross section of the suture guide holder with the suture guide attached thereto taken along line 18 - 18 of FIG. 17. FIG. 18 illustrates how groove 260 engages suture guide 261 and depicts rib 263 and the outer covering 265 of the suture guide.
[0082] Various shaped suture guide holders, C-shaped, linear and circular, have been described and illustrated in the figures, however, in accordance with the present invention, the suture guide holder can be constructed in any desired shape depending on the surgical procedure involved. For example, the suture guide holder could be curvilinear for stomach reduction surgery or for certain cosmetic surgeries when it is necessary to place a suture line along an eyelid or an ear.
[0083] While the preferred embodiments have been described, various modifications and substitutions may be made thereto without departing from the scope of the invention. Accordingly, it is to be understood that the invention has been described by way of illustration and not limitation.
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An assembly for holding a substantially flexible suture guide of predetermined length in a substantially taut position used to achieve a suture line having a dimension equal to the length of the suture guide, such as the circumference about a heart valve annulus. The assembly includes a rigid suture guide holder having a surface against which the length of suture guide is releasably positioned. The guide holder can have a shape or geometry, such as a circumference or circumferential segment, equivalent to the shape or geometry of the intended suture line. The shape of the guide holder can therefore be selected to hold the suture guide in the shape most advantageous to placing the desired suture line. The assembly further includes a mechanism for releasably binding the suture guide to the surface of the holder and a detachable handle extendibly attached to the holder by means of a lanyard so that the handle can be detached to afford an unobstructed view of the surgical site, but cannot be removed from the surgical site until the holder has also been removed.
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BACKGROUND OF THE INVENTION
The present invention relates to filament switching devices and in particular to a switching device which is designed to be compactly mounted within the screw base of a conventional electric lamp.
It is known to operate a pair of incandescent filaments so that upon failure of a primary filament an automatic switching device substitutes a secondary filament for the failed primary. A known multi-filament lamp employs a fusible conductor which restrains a spring-leaf contact. Upon failure of a primary filament the surge of current associated with failure ruptures that fusible conductor, releasing the spring-leaf contact and causing it to substitute the secondary filament for the failed primary filament. In another known example of such devices, an insulator which separates a pair of contacts breaks down upon failure of a primary filament and allows these contacts to close and substitute a secondary filament for the failed primary filament.
These known filament switching devices have generally required significant amounts of space within the screw base of a light bulb. Accordingly, manufacturers of light bulbs would require specialized machinery to handle an enlarged screw base. Moreover, the enlargement of the screw base would result in a longer lamp or in a bulb shortened to account for the enlarged screw base. Such a change in dimension or shape can be unacceptable in certain applications. Another practical impediment to successful implementation of a filament switching device has been containment of the fragments resulting from the fusing of the fusible conductor. Known devices have not had provisions for preventing such hot fused fragments from striking the fragile glass bulb. Such inadvertent contact on the glass bulb can cause its breakage which results in air leakage. Therefore, any attempt to commercialize a light bulb having an automatically switched pair of filaments would be unsuccessful.
The present invention avoids such problems and disadvantages by mounting a cantilevered and a fixed contact within a frame having a floor which branches in two directions. Since the frame branches in two directions it can fit around the evacuation tube of a conventional light bulb and thus compactly fit within the conventional screw base of such a bulb. These contacts are employed to automatically substitute another filament for a failed filament. Accordingly, a reliable light bulb can be efficiently and inexpensively manufactured using the conventional size screw base, exhaust tubing, and dual filament mount.
Moreover, since fabrication of a dual filament light bulb is commonplace, the present switching device can be reaily incorporated into existing manufacturing lines without redesign or modification of the dual filament bulbs. Also, since its screw base need not be elongated or enlarged the lamp can maintain its standard length and shape.
Since any incandescent filament has an inherently limited life, the effective life of an incandescent lamp according to the present invention can be doubled without sacrifice in luminous efficacy. This is a significant achievement, since any appreciable extension in filament life of commercial lamps necessitates lowering of the operating temperature of the filament which inevitably decreases luminous efficacy. Therefore, the so-called long life bulbs available commercially are undesirable for energy conservation. But redundancy provides reliability, which is extremely important for applications where it is prohibitively expensive or impractical to routinely rep;ace the light bulbs. Exemplary prior art are U.S. Pat. Nos. 2,049,338 and 2,217,794.
In one embodiment, the frame of the switching device branches in two directions but is bridged by a cross-piece which thereby forms a central passageway. This passageway is sized to receive the evacuation tube so that the switching device is mechanically self-aligning and compactly mounted within the associated screw base. It is also preferable that the frame of the switching device be a pair of complimentary shells shaped to fit together and encompass the fusible conductor, thereby entrapping fused fragments which may issue therefrom.
Preferably, the frame of the switching device contains the cantilevered contact in one branch and the fusible conductor in the other branch. This cantilevered contact can be designed to swing transversely to the axis of the evacuation tube. This latter feature insures that the switching device compactly fits within a conventional screw base.
SUMMARY OF THE INVENTION
In accordance with the illustrative embodiment demonstrating features and advantages of the present invention there is provided in an electric light, a filament switching device. This electric light has a translucent bulb sealing at least two filaments. These filaments are coupled by lead wires into a screw base. The above mentioned filament switching device includes a frame, a fixed contact, a cantilevered contact, a fusible conductor and a holding means. The frame has a floor which branches in two directions. The fixed and cantilevered contacts are attached to the frame. The cantilevered contact is operable to deflect laterally over the floor of the frame. This cantilevered contact is positioned to flex upon separation from the fixed contact. The frame has a holding means for restraining one end of the fusible conductor. Its other end is connected to the free end of the cantilevered contact. This holding means is operable, through the fusible conductor, to separate the cantilevered contact from the fixed contact.
According to an associated method, also in accordance with the present invention, there is provided a method for assembling an electric light. This electric light has a translucent bulb with an axial evacuation tube. The bulb seals a pair of filaments that are coupled by two pairs of lead wires to a screw base by means of the filament switching device. This switching device is mounted in a frame that branches in two directions. The method includes the steps of positioning the frame to straddle the evacuation tube. The method also includes connecting one of the lead wires from each of the pair of filaments to the device. Another step is mounting the screw base on the bulb to encircle the frame.
BRIEF DESCRIPTION OF THE DRAWINGS
The above brief description as well as other objects, features and advantages of the present invention will be more fully appreciated by reference to the following detailed description of the presently preferred but nonetheless illustrative embodiment in accordance with the present invention, when taken in conjunction with the accompanying drawings wherein:
FIG. 1 is an elevational view of a conventional monofilament bulb as known in the prior art;
FIG. 2 is an elevational view of a conventional screw base associated with the apparatus of FIG. 1, as known in the prior art;
FIG. 3 is an elevational view of a conventional dual filament 3-way light bulb as known in the prior art;
FIG. 4 is a fragmentary elevational view along lines 4--4 of FIG. 3;
FIG. 5 is an elevational view, partly in section, of a switching device according to the present invention mounted on a screw base and bulb as shown in FIGS. 2-4;
FIG. 6 is an exploded view of the switching device of FIG. 5;
FIG. 7 is an exploded view of the apparatus of FIG. 5; and
FIG. 8 is a schematic representation of the electrical connections associated with the apparatus of FIG. 5.
FIG. 9 is a modification of FIG. 6.
FIG. 10 is a perspective view of a switching device which is an alternate to that of FIG. 6;
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, a conventional translucent bulb 10 is shown fragmented to expose an evacuation tube 12. This known device has an evacuation tube 12 which is flattened at its upper end 16 to provide a mounting base for imbedded lead wires 18 and 20 which support incandescent filament 14. Referring to FIG. 2 there is shown a conventional dual terminal screw base to which the lead wires of the incandescent bulb of FIG. 1 are typically connected. One terminal of screw base 22 is axial eyelet 24 which is a concentric metal button. The other terminal of screw base 22 consists of metal shell 26 into which are formed threads 28.
Referring to FIG. 3, a conventional dual filament incandescent light bulb is illustrated. Bulb 29 houses a pair of filaments 30 and 32 which are mounted on lead wire pair 34 and 36 and lead wire pair 38 and 40, respectively. These lead wires are shown imbedded within evacuation tube 42 at its upper press 44. Referring to FIG. 4, a fragmentary elevational view along lines 4--4 of FIG. 3 is given. This view clearly illustrates the spacing between the lead wires 34 and 38. It is to be understood that lead wires 36 and 40 similarly are spaced but are hidden herein by lead wires 34 and 38, respectively. It can also be clearly seen from this figure that the press 44 of evacuation tube 42 has a split or forked cross-section.
Referring to FIGS. 5 and 7, these figures show the installation of switching device 50 within screw base 22 adjacent bulb 29. It will be noted that bulb 29 is the dual filament bulb of FIG. 3. It will also be observed that when fully assembled, evacuation tube 42 is encompassed by switching device 50, in this embodiment. It can also be observed herein that screw base 22 mounts eyelet 24 on insulating layer 52 which caps a tapered insulator 54. Insulator 54 has a tapered axial aperture 56 through which lead wire 58 is routed. The metal shell 26 is bonded to bulb 29 by cement 60.
A placing member 62 (FIG. 7) is shown as part of the conventional assembly apparatus used in a production line to assemble screw base 22 and its associated switching device 50 to bulb 29. Bulb 29 is held in place by conventional fixture 64.
Referring now to FIG. 6, an exploded view is given of the switching device previously illustrated in simplified form in FIGS. 5 and 7. A frame is shown herein as a pair of complementary shells, comprising base 70 which can be sealed by a cover 72. In this embodiment shells 70 and 72 fit together to form a hollow chamber having two orthogonal branches. However, it will be appreciated that for other embodiments the frame can have other branched shapes including closed shapes such as a hollow toroid having a central aperture sized to receive the previously described evacuation tube. FIG. 10 shows such a toroidal frame wherein components corresponding to components in FIG. 6 have reference numerals increased by one hundred. In this embodiment of FIG. 6 the frame includes a crosspiece 74 which spans the two orthogonal branches of cover 72. Essentially, cover 72 is an "L" shaped plate having depending therefrom, two joined orthogonal walls 76 and 78. The purpose of the crosspiece 74 is to form a small, triangular opening with the "L" shape frame through which the exhaust tubing 42 is positioned, and to restrict any lateral movement of the frame, which might otherwise interfere with the installation of the lamp base during assembly. In addition, cover 72 has three downwardly depending tabs 80, 82 and 84 which hold cover 72 in position when mounted upon base 70. Base 70 has a floor 86 that has a general "L" shape. Floor 86 has four upstanding walls integrally attached to its edges, except for edges 88 and 90.
Mounted in side slit 92 is a fixed contact shown herein as a bent metallic tab 94 whose outer portion is connected to previously illustrated lead wire 40. It will be appreciated that other means for mounting tab 94 are possible including adhesive. In the embodiment of FIG. 9, an upright peg 92A in floor 86A, adjacent to an inside corner of frame 70A behind which bent tab 94A can be mounted. A moveable contact is shown in FIG. 6 as a continuous metal strip comprising a leading strip segment 96 and an oblique strip segment 98. Segments 96 and 98 are formed from a continuous strip which is bent into a U-shaped clip 100 at its mid-section. Clip 100 is slipped over edge 102 of frame 70. It will be appreciated, however, that in some embodiments oblique segment 98 may be omitted and that cantilevered segment 96 can be affixed in alternate manners including adhesive mounting or an upright peg as previously described in connection with fixed contact 94. Segments 96 and 98 are shown in a retracted or open position. These two segments would, if unrestrained, swing so that segment 96 electrically contacts fixed contact 94. However, segments 96 and 98 are held and restrained in the position illustrated by means of a fusible conductor, shown herein as thin wire 104. Conductor 104 is connected between the free end of cantilevered contact 96 and lead wire 36. A holding means is shown herein as aperture 106 in cover 72. Lead wire 36, and thus conductor 104 and contact 96, are restrained in the position illustrated by means of aperture 106 in cover 72. Essentially, the upright portion of lead wire 36 is routed through aperture 106 which then restrains that lead wire from lateral movement. Accordingly, so long as conductor 104 is intact, cantilevered contact 96 is restrained from deflecting back into electrical contact with fixed contact 94. It will be appreciated that other means for restraining conductor 104 are possible. For example, the end of conductor 104 opposite the free end of cantilevered contact 96, may be connected to a terminal which is molded into a side wall of base 70. When assembled, lead wire 58 is routed through matching notch 108 in cover 72.
When cover 72 is placed atop base 70, it and its walls 76 and 78 seal base 70 so that fragments from fusible conductor 104 are captured. Accordingly, fused fragments from conductor 104 cannot come into contact with an evacuated glass bulb and crack it. This is of great importance for otherwise the molten metal upon contact with the glass will likely crack the glass, cause leakage of air into the bulb and thus, burn out the filament.
FIG. 8 is a schematic representation of the connection between filaments 30 and 32 to the previously described switching device and screw base. One terminal each of filaments 30 and 32 are connected to the metal shell 26 of screw base 22. Each remaining terminal of filaments 30 and 32 is connected to one end of fusible conductor 104 and fuse element 110, respectively. The other ends of conductors 104 and 110 are connected to cantilevered contact 96 and fixed contact 94, respectively. Fusible conductor 104 has been previously described. Fuse element 110 is similarly constructed and is welded in series with filament 32. Cantilevered contact 96 is also connected to the eyelet 24 of screw base 22.
To facilitate an understanding of the foregoing apparatus, its operation will be briefly described. As manufactured cantilever contact 96 is in the position shown in FIGS. 6 and 8. Accordingly, an electrical connection exists from eyelet 24 (FIG. 8) through fusible conductor 104 to one terminal of filament 30, the other terminal of filament 30 being commonly connected to the threaded metal shell 26 of screw base 22 (FIG. 8). It is well known that filament failure is frequently preceded by a gradual thinning of the cross-sectional area of the filament. Such thinning can be caused by migration of gasseous impurities towards a "hot" spot on the filament. Such a thinned cross-section causes a localized high resistance which creates a localized hot spot. At failure, as the filament separates a plasma state exists and thus causes a high flux of current to suddenly rush across the point of rupture. Accordingly, the fusible conductor is overheated and melted by the high current flowing through it. Accordingly, conductor 104 ruptures and allows cantilevered contact 96 to swing into contact with fixed contact 94. The swing of cantilevered contact 96 is motivated by release of its internal tension as well as the urging from oblique segment 98. Upon rupture of conductor 104 the connection between eyelet 24 and filament 30 terminates. Upon closure of contacts 94 and 96, eyelet 24 is connected through fusible conductor 110 to one terminal of filament 32. The other terminal of filament 32 being commonly connected to metal shell 26, current flows through filament 32. This sequence completes the substitution of filament 30 with filament 32.
Upon a similar failure of filament 32, an inrush of current melts fuse element 110. The melting of this conductor protects the main power lines and prevents excessive current.
The manufacture of the foregoing apparatus can be achieved with conventional hardware and manufacturing implements. Moreover, many of the components will be common to conventional lamps.
Referring to FIGS. 6 and 7, assembly proceeds by fitting switching device 50 over evaucation tube 42 while connecting lead wires 40 and 36 to fixed contact 94 and fusible conductor 104, respectively, within device 50. Next a connection is made between eyelet 24 of screw base 22 to cantilever contact 96 of device 50. Thus connected the remaining two lead wires 34 and 38 are connected to the threaded metal shell 26 of screw base 22. Finally, the screw base 22 is cemented onto the neck of bulb 10 in a conventional fashion. Thus assembled the device is ready for use and will operate in the manner previously described.
It is to be appreciated that modifications and alterations can be implemented with respect to the apparatus just described. For example, various materials can be used to fabricate the frame and its contact. It is anticipated that molded plastic or other insulators can be used to fabricate the frame. Moreover, the specific shape and dimensions of the various components can be altered as a matter of design. In addition, it is expected that the cantilevered contact can be motivated by its internal tension or alternatively, by a permanent magnet. In addition, various other materials of different dimensions can be substituted to provide the desired size, shape, wear, power handling capability, temperature stability, sensitivity to current surges etc. Obviously many other modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as previously described.
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A filament switching device is arranged to be mounted within the screw base of a conventional, dual-filament, incandescent light bulb. The device has a frame which branches around the evacuation tube of the bulb thereby allowing sufficient room for switching components within the device and yet avoiding interference with the evacuation tube of the bulb. Mounted within the frame of the switching device is a fixed contact and a cantilevered contact. The cantilevered contact can swing in a direction transverse to the evacuation tube to make electrical contact with the fixed contact. The cantilevered contact is held separated from the fixed contact by a fusible conductor. Upon failure of one of the filaments in the bulb a surge of current flows through the fusible conductor, parting it and allowing the cantilevered contact to swing into electrical contact with the fixed contact. This swing of the cantilevered contact substitutes the failed filament with the other filament.
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TECHNICAL FIELD OF THE INVENTION
[0001] The present invention relates to a multiple output magnetic sensor that can be used to sense multiple positions of an object. Such a sensor can be used, for example, to indicate the half-latch and full-latch positions of an automobile door.
BACKGROUND OF THE INVENTION
[0002] It is desirable and sometimes necessary to sense the positions of various devices that can assume multiple positions. one such device is the door of an automobile. The latches of such doors typically have half-latch and full-latch positions. When the door is in the full-latch position, the latch is fully engaged and the door in its fully closed position. When the door is in the half-latch position, the door in not in its fully closed position but the latch is sufficiently engaged to prevent the door from opening without further intervention by an operator. When the door is in neither the full-latch position nor the half-latch position, the door is open.
[0003] There are several reasons to sense these door latch positions. For example, the driver of an automobile can be notified when a door is in the full-latch position, or is in the half-latch position, or is open. Alternatively, power assist doors are being contemplated in which a motor or actuator is used to pull the door tightly closed to, for example, better shut out exterior noise. In this case, it is desirable to sense the half-latch position of the door in order to energize the motor so that it pulls the door to the full-latch position, and to then sense the full-latch position in order to prevent further pulling by the motor.
[0004] Hall sensors have been used to sense the position of objects by.detecting the presence or absence of a magnetic field. Thus, a small magnet may be attached to an object whose position is be sensed, and the magnetic field of the magnet is detected by the Hall sensor in order to determine the position of the object. If the circuit that processes the signal from the Hall sensor is configured for uni-polar operation and has a digital output, the sensor will turn on when the magnetic field from the magnet exceeds a pre-defined threshold and will be off the rest of the time (ignoring the effects of hysteresis). Therefore, the circuit will only be able to detect when the object is in a certain discrete position.
[0005] In applications requiring the detection of multiple positions, such as the automobile door application discussed above, an encoded signal is frequently utilized. However, if only one Hall sensor is to be used to detect multiple positions, a complex time based extrapolation algorithm is required to determine the multiple positions.
[0006] To avoid the use of such an algorithm, a separate discrete Hall sensor can be used to detect each of the various positions of the object. However, the use of multiple Hall sensors increases the cost of the position detection system. In high volume industries such as the automobile industry, the cost can bercome significant.
[0007] The present invention relates to a multiple position sensor that overcomes one or more of these or other problems.
SUMMARY OF THE INVENTION
[0008] According to one aspect of the present invention, a door position sensing system comprises a door claw, a receiver, and a processor. The door claw has first and second transmitters mounted thereon. The receiver is mounted so as to receive signals transmitted by the first and second transmitters. The processor is responsive to the receiver to provide outputs indicating first and second positions of a door corresponding to the first and second transmitters.
[0009] According to another aspect of the present invention, a system comprises a mounting structure having a periphery, a first magnet, a second magnet, and a magnetic field sensor. The first magnet has a first North pole and a first South pole, and the first magnet is mounted on the mounting structure at the periphery such that the first North pole faces the periphery and the first South pole faces away from the periphery. The second magnet has a second North pole and a second South pole, and the second magnet is mounted on the mounting structure at the periphery such that the second South pole faces the periphery and the second North pole faces away from the periphery. The magnetic field sensor senses the first and second magnets upon relative movement between the magnetic sensor and the mounting structure.
[0010] According to still another aspect of the present invention, a door latch claw comprises a door claw plate having a periphery, a first transmitter mounted on the door claw plate at the periphery to transmit a signal indicative of a half-latch position of the door claw plate, and a second transmitter mounted on the door claw plate at the periphery to transmit a signal indicative of a full-latch position of the door claw plate.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] These and other features and advantages will become more apparent from a detailed consideration of the invention when taken in conjunction with the drawings in which:
[0012] [0012]FIG. 1 illustrates an automobile providing an exemplary application for the present invention;
[0013] [0013]FIG. 2 illustrates a partial door assembly for the automobile of FIG. 1;
[0014] [0014]FIG. 3 illustrates the position of a door claw that is part of a door.latch for the door of FIG. 2 and that is shown in a door open position;
[0015] [0015]FIG. 4 illustrates the position of the door claw of FIG. 3 when the door claw is in a door half-latch position;
[0016] [0016]FIG. 5 illustrates the position of the door claw of FIG. 3 when the door claw is in a door full-latch position;
[0017] [0017]FIG. 6 illustrates an exemplary processing circuit that processes signals emitted by transmitters mounted on the door claw of FIG. 3; and,
[0018] [0018]FIG. 7 shows a relative arrangement of transmitters and signals produced by the door claw and processing circuit shown in FIGS. 3-6.
DETAILED DESCRIPTION
[0019] As illustrated in FIG. 1, an automobile 10 has a door 12 which can be latched in half-latch and full-latch positions by a door latch 14 . As shown in FIG. 2, the door latch 14 includes a door claw 16 mounted to the door 12 and a striker 18 mounted to a post 20 of the frame of the automobile 10 .
[0020] The door claw 16 is shown in more detail in FIGS. 3, 4, and 5 . The door claw 16 comprises a door claw plate 22 that is supported by the door 12 of the automobile 10 and in turn supports first and second magnets 24 and 26 . The door claw plate 22 . has a periphery 28 , and the door claw plate 22 supports the first and second magnets 24 and 26 at the periphery 28 . The door claw plate 22 also has a recess 40 that engages the striker 18 mounted on the post 20 of the frame of the automobile 10 . Thus, as the door 12 is closed, the striker 18 enters the recess 40 , engages the door claw plate 22 , and rotates the door claw plate 22 about an axis of rotation 42 .
[0021] Also mounted on the frame of the automobile 10 is a printed circuit board 44 supporting a Hall sensor 46 and a processing circuit 48 comprising one or more electronic and/or electrical components. The printed circuit board 44 electrically couples the Hall sensor 46 to the processing circuit 48 . The printed circuit board 44 is mounted on the automobile frame so that the Hall sensor 46 senses the magnetic fields of the first and second magnets 24 and 26 as the first and second magnets 24 and 26 move past the Hall sensor 46 during rotation of the door claw plate 22 .
[0022] [0022]FIG. 3 shows the position of the door claw 16 when the door 12 is fully open, i.e., not in either the half-latch position or the full-latch position. As the door 12 of the automobile 10 closes, the striker 18 mounted to the post 20 of the frame of the automobile 10 enters the recess 40 and begins rotating the door claw 16 about the axis of rotation 42 . When the door claw 16 rotates to its half-latch position, the door claw 16 is in the position shown in FIG. 4 where the first magnet 24 is in close proximity to the Hall sensor 46 . As the door 12 of the automobile 10 continues to close, the striker 18 mounted to the post 20 of the frame of the automobile 10 continues to rotate the door claw 16 about the axis of rotation 42 . When the door claw 16 rotates to its full-latch position such that the door 12 of the automobile 10 is fully closed, the door claw 16 is in the position shown in FIG. 5 where the second magnet 26 is in close proximity to the Hall sensor 46 .
[0023] The Hall sensor 46 senses the presence of the first and second magnets 24 and 26 and provides corresponding output signals to the processing circuit 48 . Based on these outputs signals from the Hall sensor 46 , the processing circuit 48 provides half-latch and full-latch outputs to indicate the half-latch and full-latch positions of the door claw 16 .
[0024] [0024]FIG. 6 illustrates an exemplary arrangement for the processing circuit 48 , and FIG. 7 illustrates the relative orientation and position of the first and second magnets 24 and 26 to produce half-latch and full-latch outputs from the processing circuit 48 . As shown in FIG. 7, the first magnet 24 may be mounted on the door claw 16 with the North pole of the first magnet 24 at the periphery 28 . On the other hand, the second magnet 26 may be mounted on the door claw 16 with the South pole of the second magnet 26 at the periphery 28 .
[0025] With this orientation of the first and second magnets 24 and 26 , the Hall sensor 46 provides a positive going signal in response to the first magnet 24 and a negative going signal in response to the second magnet 26 . As shown in FIG. 6, the processing circuit 48 includes a non-inverting first operational amplifier 50 having its positive input coupled to the output of the Hall sensor 46 , and an inverting second operational amplifier 52 having its negative input coupled to the output of the Hall sensor 46 .
[0026] Accordingly, as the door claw 16 rotates from its door open position shown in FIG. 3 to its half-latch position shown in FIG. 4, the first operational amplifier 50 produces an output pulse 54 indicating that the door 12 has moved into the half-latch position. Then, as the door claw 16 rotates from its half-latch position shown in FIG. 4 to its full-latch position shown in FIG. 5, the second operational amplifier 52 subsequently produces an output pulse 56 indicating that the door 12 has moved into the full-latch position.
[0027] As can be seen, both of the output pulses 54 and 56 are shown with a positive polarity. However, both of the output pulses 54 and 56 may have the same negative polarity, or one of the output pulses 54 and 56 may have a positive polarity and the other of the output pulses 54 and 56 may have a negative polarity.
[0028] Moreover, the output pulses may be either voltage pulses or current pulses. Furthermore, instead of providing output pulses on separate pins (the outputs of the first and second operational amplifiers 50 and 52 ), pulses may be provided on a single pin, in which case, the pulses may be distinguished by different voltage or current levels. Accordingly, the outputs can be two voltage outputs with either different or same polarities, two current outputs with either different or same polarities, one voltage output with several voltage levels, and/or one current output with several current levels. Additionally, an interface can be provided where the information is transmitted serially (for example, using pulse width modulated signals associated with particular sensed conditions).
[0029] Certain modifications of the present invention have been discussed above. Other modifications of the present invention will occur to those practicing in the art of the present invention. For example, as described above, the first and second magnets 24 and 26 mounted on the door claw 16 have corresponding magnetic fields, and the Hall sensor 46 is mounted so as to sense the magnetic fields of the first and second magnets 24 and 26 . The first and second magnets 24 and 26 may be viewed as magnetic field transmitters, and the Hall sensor 46 may be viewed as a magnetic field receiver. Other types of transmitters may be mounted on the door claw 16 to transmit signals indicating the position of the door claw 16 . For example, the transmitters mounted on the door claw 16 may be electromagnetic transmitters, optical transmitters, sonic-transmitters, RF transmitters, etc. The sensor such as the Hall sensor 46 must be suitably chosen to complement the particular transmitter.
[0030] Also, as described above, the Hall sensor 46 is stationary with respect to the first and second magnets 24 and 26 . However, in some applications, the first and second magnets 24 and 26 may be stationary with respect to the Hall sensor 46 .
[0031] Accordingly, the description of the present invention is to be construed as illustrative only and is for the purpose of teaching those skilled in the art the best mode of carrying out the invention. The details may be varied substantially without departing from the spirit of the invention, and the exclusive use of all modifications which are within the scope of the appended claims is reserved.
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A door position sensing system includes a door claw having first and second magnets mounted thereon, and a Hall sensor mounted so as to sense the magnetic fields of the first and second magnets. The first magnet is mounted in a door half-latch position, and the second magnet is mounted in a door full-latch position. A processor is responsive to the Hall sensor to provide outputs indicating the half-latch and full-latch positions of a door. The processor may also be arranged to indicate a door open position when neither magnet is near the sensor.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention is a system that provides for the remote sensing of a low vehicle tire pressure condition and the generation of a signal indicating the presence of the low pressure condition. This invention is also a sensor for use in the system.
2. Description of the Prior Art
Systems for remotely monitoring vehicle tire pressure were developed many decades ago and inventors have been improving on them ever since. Tire pressure monitoring systems will be required in passenger vehicles sold in the US beginning with model year 2008. The requirements for those systems are spelled out in the TREAD Act and have been known for some time.
SUMMARY OF THE INVENTION
The present invention is based on the discovery of an elegantly simple and reliable system for monitoring tire pressure and providing a signal in the event that a low tire pressure condition has been sensed or that a tire pressure sensor is not functioning. The system comprises a sensor for mounting in each tire to be monitored and an associated transceiver antenna coil that is mounted near each monitored tire. Each sensor comprises a pressure switch and a circuit that includes an antenna coil and a reference capacitor which establish a reference resonant frequency for the circuit. The circuit also includes an additional capacitor, hereinafter referred to as a condition capacitor, that is inactive when the pressure switch is in a first state and is actively connected in parallel with the reference capacitor when the pressure switch is in a second state. When the pressure switch is in the first state and the condition capacitor is inactive, the sensor circuit will have a first resonant frequency and, when the pressure switch is in the second state and the condition capacitor is actively connected in the sensor circuit, it will have a second resonant frequency that is different from the first resonant frequency. Each transceiver antenna coil is operatively associated with an exciter circuit that generates an AC electromagnetic field across the transceiver antenna coil and with a detector circuit that is operable to demodulate information communicated passively by the sensor that reflects its resonant frequency. Preferably, each transceiver antenna coil is sequentially activated so that a single sensor is interrogated or polled at a given time. In this way, a signal may be correlated with a particular tire reflecting the state of the pressure switch in the sensor on that tire.
Accordingly, it is an object of this invention to provide a reliable tire pressure monitoring system comprising a sensor and a transceiver antenna for each tire.
It is another object of the invention to provide a wheel mounted sensor that operates reliably and without power internal to the sensor such as might be provided by batteries.
It is yet another object of the invention to provide a tire pressure monitoring system that includes a sensor that cooperates with a transceiver to produce a first signal indicating that the system is operable and a second signal that indicates either that a low pressure condition has been sensed or that the system has somehow become inoperable.
It is a further object of this invention to provide a sensor including a pressure switch that is bi-stable and will change from a first state to a second state when a low tire pressure condition is detected and will remain in the second state until there is a substantial increase in the tire pressure.
These and other objects and advantages of the invention will be apparent from the following detailed description of the invention including the preferred embodiments, reference being made therein to the attached drawing figures.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic representation of a sensor and an associated transceiver according to the present invention.
FIG. 2 is a generalized graph showing the resonant frequency of the sensor when the pressure switch is in a first state and the resonant frequency of the sensor when the pressure switch is in a second state.
FIG. 3 is a schematic representation of the system applied to a four wheeled vehicle in a configuration that will identify the condition of each sensor independently of the condition of the other three sensors.
FIG. 4 is a perspective view of a sectioned in-line embodiment of a sensor according to the present invention.
FIG. 5 is another perspective view of the in-line sensor shown in FIG. 4 .
FIG. 6 is a perspective view of a multiple chambered embodiment of a sensor according to the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now in more detail to the drawing figures, FIG. 1 shows a schematic diagram of a tire pressure monitoring system according to the invention, indicated generally at 10 , for a single wheel. The system 10 comprises a transceiver 12 and a sensor 14 . The transceiver 12 , or a portion of it, is adapted to be mounted on the vehicle, for example, in or adjacent to the wheel well associated with the tire in which the pressure is to be monitored. The sensor 14 is adapted to be mounted inside of a tire or at least associated with the tire so that a portion of the sensor is exposed to the ambient pressure inside of the tire.
The transceiver 12 comprises an exciter circuit 16 that is operable to generate an AC electromagnetic field across an antenna coil 18 . The transceiver 12 further comprises a detector circuit 20 that is operable to demodulate signals produced or induced in the sensor 14 .
The sensor 14 has a circuit that comprises an antenna coil 22 and a reference capacitor 26 . When alternating current passes through the transceiver antenna coil 18 , the sensor antenna coil 22 will be inductively coupled to the transceiver antenna coil 18 and alternating current will be induced to flow through the sensor antenna coil 22 . The circuit comprising the sensor antenna coil 22 and the reference capacitor 26 will have a resonant frequency which is referred to herein as a reference resonant frequency.
The sensor circuit also includes a condition capacitor 28 and a pressure switch 30 . The pressure switch 30 is bi-stable meaning that it is only stable in two distinct conditions or positions and not in between those two positions or conditions. This should not be construed to mean that the switch might not be a tri-stable switch that is stable in only three positions or a switch that is stable in more than three positions. It does mean that when the switch changes from a first state to a second state that it will remain in the second state despite relatively minor fluctuations in the ambient pressure.
When the pressure switch 30 is in a first state, the condition capacitor 28 is inactive and inoperable in the sensor circuit and does not affect the resonant frequency of the sensor circuit. In this embodiment, when the pressure switch 30 is in the first state, the resonant frequency of the sensor circuit will be a condition resonant frequency. When the pressure switch 30 is in a second state, the condition capacitor 28 is actively connected in parallel with the reference capacitor 26 , the resonant frequency of the sensor circuit will be the reference resonant frequency and that will be different than the condition resonant frequency. This is shown, in general terms, in the plots in FIG. 2 . The solid line plot is a stylized representation of the impedance of the sensor circuit with the pressure switch 30 in the second state and the condition capacitor 28 in parallel with the reference capacitor 26 , at various frequencies. The sensor circuit with the condition capacitor 28 connected in parallel with reference capacitor 26 has a Reference resonance frequency R(RF), which is the frequency at which the impedance of the circuit is highest. This Reference resonant frequency C(RF) is detectable by the transceiver 12 and provides a positive indication that the transceiver 12 and the sensor 14 are operative and that the pressure switch 30 is in the second state. When the pressure switch 30 is in its first state and the condition capacitor 28 is out of the sensor circuit and not in parallel with the reference capacitor 26 , the resonant frequency of the sensor circuit will be, for example, as shown in FIG. 2 , a Condition resonant frequency R(RF) shown in a dashed line in FIG. 2 . The Reference resonant frequency R(RF) will be lower than the Condition resonant frequency C(RF) in the case where the pressure switch 30 is open and the condition capacitor 28 is not in the sensor circuit in parallel with the reference capacitor 26 . A frequency detector in the detector 20 can detect the frequency of the signal resulting from the induced current flowing in the sensor circuit and thereby provide a signal indicating whether the resonant frequency coincides with the Reference resonant frequency or the Condition resonant frequency.
Referring now to FIG. 3 , a system, indicated generally at 32 , for monitoring the tire pressure in four tires of a vehicle is illustrated schematically. First, second, third and fourth tire sensors 34 , 36 , 38 and 40 corresponding generally with sensor 14 ( FIG. 1 ) are provided in the system 32 . Each sensor is associated with a corresponding transceiver antenna coil. First sensor 34 is adjacent to a first transceiver antenna coil 42 . Second sensor 36 is adjacent to a second transceiver antenna coil 44 . Third sensor 38 is adjacent to a third transceiver antenna coil 46 . Fourth sensor 40 is adjacent to a fourth transceiver antenna coil 48 . The transceiver antenna coils 42 , 44 , 46 and 48 are operably and, preferably sequentially, connected through a multiplexer 50 to a transceiver detector 52 and an exciter 54 . The multiplexer 50 is operable to selectively and sequentially connect the detector 52 and the exciter 54 to the various transceiver antenna coils 42 , 44 , 46 and 48 under the control of a selector 56 . The multiplexer 50 provides the capability for a single sensor to be activated or interrogated or polled at a time so that a sensor signal received by a given transceiver antenna can be correlated and associated with a particular tire.
Referring now to FIGS. 4 and 5 , an embodiment of a sensor according to the present invention is indicated generally at 58 . The sensor 58 comprises an antenna coil 60 mounted on a printed circuit board 62 which, in turn, is mounted at one end of a sensor body 64 The printed circuit board 62 includes at least a first capacitor (not shown) and a second capacitor (not shown) although, if desired, one or both capacitors could be mounted outside of the printed circuit board 62 . The coil 60 is physically and electrically connected to the printed circuit board 62 at junctions 66 . When a pressure switch in the sensor 58 is in a second state, the first capacitor, which corresponds with the reference capacitor 26 ( FIG. 1 ) and the second capacitor, which corresponds with the condition capacitor 28 ( FIG. 1 ), are electrically connected, parallel with each other and in series with the coil 60 . When the pressure switch is in a first state, just the first capacitor is electrically connected in series with the coil 60 in the sensor circuit.
The sensor 58 includes a pressure switch comprising a pressure membrane 68 that is mounted in a cavity in the sensor body 64 between two seals comprising a first O-ring 70 and a second O-ring 72 . The membrane 68 and the O-rings 70 and 72 are held in place by an externally threaded ring 74 which cooperates with internal threads 76 in the sensor body 64 . The membrane 68 together with the O-ring 72 and an adjacent portion of the sensor body 64 define a reference pressure chamber 78 . A central passageway 80 in the sensor body 64 houses a central conductor 82 which is subject to electrical contact with the membrane 68 , at one end, and is electrically connected at the other end to the printed circuit board 62 through a junction 84 . The central passageway 80 is sealed by or around the central conductor 82 so that the pressure chamber 78 is a sealed chamber except for an initialization passageway 86 that extends from the pressure chamber 78 to the outside of the sensor body 64 . Before the sensor 58 is ready for use, the pressure chamber 78 can be pressurized to a reference pressure, through the initialization passageway 86 , and the passageway 86 can then be sealed so that the reference pressure is maintained in the pressure chamber 78 .
The membrane 68 is a bi-stable, snap action diaphragm membrane, so-called because of its properties when it is exposed to pressure differentials on either side of it. In service, the membrane will be exposed, on one side, to the pressure in the reference pressure chamber 78 and, on the other side, to ambient pressure prevailing inside of a tire. The membrane 68 has a central region 88 that is generally flat and is surrounded by an extremely shallow, conically-shaped region 90 . Outside of the region 90 , there is another, generally flat, ring-shaped region 92 . The membrane is preferably made of a conductive material and, preferably, a springy, corrosion-resistant material such as stainless steel having a minimal thickness, such as about two thousandths of an inch, so that it is very flexible. With the perimeter of the membrane 68 constrained between the O-rings 70 and 72 , the membrane 68 will try to assume one of two neutral positions or states for it. One neutral position or state, referred to herein as the first state, is shown in FIG. 4 where the central region 88 is spaced from the central conductor 82 . In the other neutral position or state, referred to hereinafter as the second state, the central region 88 of the membrane 68 is in contact with the central conductor 82 , as shown in FIG. 5 .
It is preferred that the membrane 68 be conductive, as shown in FIGS. 4 and 5 . The membrane 68 cooperates with the sensor circuit to determine whether or not the condition capacitor (not shown) will be in or out of the sensor circuit. The membrane 68 is electrically connected to the printed circuit board 62 through a conductor 94 that extends from a printed circuit board junction 96 to the membrane 68 . When the pressure membrane 68 is in the second state, it contacts the central conductor 82 and the printed circuit board junctions 84 and 96 are electrically connected. In this case, the condition capacitor will be in the sensor circuit in parallel with the reference capacitor. Pressure inside of the tire acting on one side of the membrane 68 , when high enough, will maintain the membrane 68 in the second position or state. When the pressure in the tire is no longer high enough to maintain the membrane in the second position or state, the membrane 68 will snap into the first position or state, electrically disconnecting junctions 84 and 96 and preventing the condition capacitor from acting in parallel with the reference capacitor, thereby changing the resonant frequency of the sensor circuit from the reference resonant frequency to the condition resonant frequency. The sensor 58 can be designed so that the membrane 68 will snap from the second position or state into the first position or state at a desired threshold, for example, 75 percent of the recommended tire pressure as required under the TREAD Act. One important characteristic of the sensor 58 and, specifically, the membrane 68 in the sensor 58 , is that once the membrane 68 snaps into the first position or state, it will maintain that position or state despite fluctuations in the pressure inside of the tire. In other words, oscillation of the membrane between positions or states, at or near the threshold pressure, is positively avoided by the snap action membrane. It can be designed to stay in the first position or state even when the pressure in the tire increases by one, two, three or more psig. There would be some advantage if the sensor membrane was designed to snap back from the first position or state to the second position or state when the pressure in the tire reaches the recommended tire pressure, thereby changing the sensor 58 back to the second state indicating that the tire pressure is okay.
An alternative embodiment of a sensor according to the invention is indicated at 100 in FIG. 6 . The sensor 100 comprises a housing 102 with a central aperture or bore 104 for housing a valve (not shown) for inflating a tire associated with the sensor. A valve would extend through the bore 104 , downwardly in FIG. 6 , and extend out of the rim on which the sensor was mounted so that the housing 102 would be positioned inside of the rim. The sensor 100 further comprises a pressure switch indicated generally at 106 and comprising a snap action pressure membrane 108 . A sensor antenna coil 110 is mounted on the opposite side of the central aperture 104 from the pressure switch and it is electrically connected to a reference capacitor 112 . A condition capacitor (not shown) is housed within the housing 102 and is connected in the manner described above with reference to FIGS. 4 and 5 for the condition capacitor. In fact, the sensor 100 operates just the same way as the sensor 58 ( FIGS. 4 and 5 ).
It will be appreciated that various changes and modifications are possible from the specific details of the invention shown in the attached drawing figures and described above with reference thereto, and such changes and modifications can be made without departing from the spirit thereof as defined in the attached claims. For example, in place of a snap action membrane, a pressure switch membrane might be stable in three positions and the third position might enable or disable an additional circuit component to provide a further signal indicating the state of the pressure switch. For example, a second condition capacitor might be employed in a sensor circuit in a sensor having a tri-stable pressure membrane. Further, the sensor can take other forms not specifically described herein. The sensor can be mounted on the rim of a tire, on or with a valve for the tire or otherwise so long as ambient pressure inside of the tire is in communication with one side of the pressure membrane.
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A system for monitoring tire pressure and producing a first signal in the event that a low tire pressure condition has been sensed and a second, different signal in the event that a low tire pressure condition has not been sensed and a third signal in the event that the system is not operable. The system comprises a sensor for each tire and an associated transceiver antenna coil. Each sensor comprises a pressure switch and a circuit that has a first resonant frequency when the pressure switch is in a first state and a second, different resonant frequency when the switch is in a second state. An excited circuit associated with each transceiver antenna coil generates an AC electromagnetic field across the transceiver antenna coil and a detector circuit is operable to demodulate information communicated passively by the sensor that reflects its resonant frequency.
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BACKGROUND OF THE INVENTION
The present invention relates generally to display systems and, more specifically, to light-transmissive display systems that become visible when illuminated.
In the world of consumer electronic devices, there has been an ever-present demand for improved appearance, improved functionality, and improved aesthetics. Industrial design has become a highly skilled profession that focuses on fulfilling this need for enhanced consumer product appearance, functionality, and aesthetics.
Much of the aesthetic appeal of an electronic device or other consumer product may quickly be compromised if there are too many display elements, lights, and indicators, or if too much of the visible display area is occupied by display elements that are not needed or relevant at all times. When not needed, these “passive” or inactivated visual display elements may remain perceptible to the user, even though in the “off” state. This is not only displeasing from an aesthetic standpoint, but it can be an annoying distraction that interferes with the perception and understanding of other visual display elements that are of greater importance or should be observed at a given moment.
Therefore, it can be seen that there is a need to present displays, lights, and other visual indicators for a user in a manner that is readily understandable, yet uncluttered and aesthetically pleasing.
SUMMARY
In one aspect, a display system comprises a housing having an interior surface and an exterior surface; a light source located within the housing; and a plurality of micro perforations disposed to extend from the interior surface to the exterior surface of the housing, wherein the plurality of micro perforations pass through the housing at different angles with respect to a plane of the exterior surface of the housing.
In another aspect, an electronic computing apparatus comprises a plurality of micro perforations disposed to extend from an interior surface to an exterior surface of a housing of the electronic computing device, the plurality of micro perforations including at least a first set of micro perforations disposed at a first angle relative to an external plane of the housing, and a second set of micro perforations disposed at a second angle relative to the external plane of the housing.
In a further aspect, a mobile computing device comprises a computing device capable of receiving, processing, and outputting data; a plurality of keys having a key top coupled to the computing device and configured to generate touching signals; a plurality of micro perforations disposed to extend from an interior surface to an exterior surface of a key top on the keys; and a light source under each of the plurality of the key tops.
These and other features, aspects and advantages of the present invention will become better understood with reference to the following drawings, description and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a front view of a notebook personal computer according to an exemplary embodiment;
FIG. 1B is a close up view of a front cover of the notebook personal computer according to the exemplary embodiment shown in FIG. 1A ;
FIG. 1C is a close up view of a part of a keyboard of the notebook personal computer according to the exemplary embodiment shown in FIG. 1A ;
FIG. 1D is a close up view of a plurality of micro perforations on the front cover of the notebook personal computer according to the exemplary embodiment shown in FIG. 1A ;
FIG. 2A is a side view of a notebook personal computer according to the exemplary embodiment of FIG. 1A ;
FIG. 2B is a cross sectional view of a back cover of the upper housing at one angle with a lower housing of FIG. 1A ;
FIG. 2C is a cross sectional view of a back cover of the upper housing at another angle with a lower housing of FIG. 1A ;
FIG. 2D is a cross sectional view of a back cover of the upper housing at yet another angle with a lower housing of FIG. 1A ;
FIG. 2E is a plan view of an exterior surface of the back cover of the upper housing according to an exemplary embodiment of FIG. 1A ;
FIG. 2F is a plan view of an exterior surface of the back cover of the upper housing according to another exemplary embodiment; and
FIG. 2G is a plan view of an exterior surface of the back cover of the upper housing according to yet another exemplary embodiment.
DETAILED DESCRIPTION OF EMBODIMENTS
The following detailed description is of the best currently contemplated modes of carrying out exemplary embodiments. The description is not to be taken in a limiting sense, but is made merely for the purpose of illustrating the general principles, since the scope of the embodiments is best defined by the appended claims.
Various inventive features are described below that can each be used independently of one another or in combination with other features.
Broadly, exemplary embodiments comprise an aesthetically pleasing visual display that may be backlit. More specifically, exemplary embodiments may provide visual displays that may include a micro perforated and backlit display having alternative display capabilities. Such displays may be used on electronic or other personal devices. A plurality of micro perforations may be arranged into an overall pattern. Each micro perforation may have a diameter of about 100 microns or less, which is not visible unless seen very closely. In some embodiments, a first set of micro perforations may be cut at a first angle through a back cover of a lid of a laptop computer, for example, and a second set of micro perforations may be cut at a second angle through the back cover. When a user opens the lid, a logo pattern at the back cover of the lid may change as light passing through the first set of micro perforations that may be visible at a first angle of the lid and light passing through the second set of micro perforations that may be visible at a second angle of the lid. In some embodiments, a plurality of micro perforations may be formed through a key top of a keyboard.
Referring to FIG. 1A , a notebook PC 10 may comprise an upper housing 110 , such as a display unit, and a lower housing 120 , such as a system unit, for example. The upper housing 110 and the lower housing 120 may be connected via a linking member 122 , such as a hinge member. The notebook PC 10 may be a laptop computer system, such as one of the ThinkPad® series of personal computers sold by Lenovo (US) Inc. of Morrisville, N.C., or a workstation computer, such as the ThinkStation®, which is sold by Lenovo (US) Inc. of Morrisville, N.C.
The notebook PC 10 may include a processor (not shown) within the lower housing 120 . A liquid crystal display (LCD) 114 , which may be a touch sensitive screen, for example, may be disposed on a front cover 111 of the upper housing 110 . The liquid crystal display 114 may be coupled to be operable by the processor to display data to a user of the notebook PC 10 .
The upper housing 110 and the lower housing 120 may move pivotally around the linking member 122 . The upper housing 110 may be rotatable relative to the lower housing 120 . The lower housing 120 may include a top cover 126 and an input device, such as a keyboard 124 .
Referring to FIG. 1B , the top cover 126 may include a visual display, such as the Lenovo® logo 182 and ThinkPad® logo 192 . Although the visual display is in the form of a logo, it will be readily appreciated that a wide variety of shapes, sizes, and types of visual displays may be used, and that such displays may be logos, trademarks, texts, advertisements, or other general types of patterns or displays. An exemplary embodiment may be used for visual displays on other items, such as, cell phones, smart phones, Global Positioning Systems (GPS), or electronic dictionaries, for example. In addition, an exemplary embodiment may also be used for visual displays on other items that may not be electronic devices, as will be readily appreciated, and all such other users are specifically contemplated.
The Lenovo® logo 182 and the ThinkPad® logo 192 may comprise a pattern of numerous micro perforations 194 formed in the material of the top cover 126 . The Lenovo® logo 182 and the ThinkPad® logo 192 can be, for example, a micro perforated and backlit display having a different surface finish than the rest of top cover 126 . The backlit display may be illuminated by a light source 220 (shown in FIG. 2B ), such as light emitting diodes (LEDs), disposed within the lower housing 120 , behind the micro perforations in the top cover 126 .
In exemplary embodiments, micro perforations formed in the top cover 126 for such a display may be small enough so that they cannot be readily distinguished from the base material surface by the naked human eye, but are large enough so that light may pass therethrough and be seen by the naked human eye when such light is provided behind the micro perforations. In general, such micro perforations may extend from one side of the base material to another side, such that light may pass therethrough. Such micro perforations may be about 50 microns or less in diameter, and typically about 20 to 30 microns in diameter. It is thought that a diameter of about 30 microns or less tends to result in such micro perforations being “invisible” to the naked eye for most observers.
Such micro perforation patterns may be formed on a surface of an opaque base object where the subject visual display is desired. Although metallic surfaces are used frequently, such as, stainless steel, aluminum, titanium, copper, magnesium and the like, for example, other base objects that are readily amenable to the formation of such micro perforations may be used.
Micro perforations may be cut by lasers at slanted angles such that a user may see the Lenovo® logo 182 , but not the ThinkPad® logo 192 from a first direction 180 . In the same way, a user may see the ThinkPad® logo 192 but not the Lenovo® logo 182 from a second direction 190 .
Referring to FIG. 1C , the keyboard 124 may comprise a plurality of keys 128 . Each of keys 128 may have a key top 130 and side walls 132 . A plurality of the key tops 130 may be coupled to the notebook PC 10 to generate touching signals. An alphabet letter 134 , such as “Y”, may be formed by a pattern of micro perforations formed on the top cover 128 . Other characters, such as Japanese Hiragana or Katakana letters 136 , such as “ ”) may be formed by a pattern of micro perforations on the side walls 132 of the keys 128 . Under the key top 130 , there may exist a light source 220 (shown in FIG. 2B ), such as light emitting diodes (LEDs), for example. The LEDs may be turned on by a user pushing a key or button on the keyboard 124 , or on some other place on the notebook 10 , to emit light rays through micro perforations so that users may see the Japanese Hiragana or Katakana letters when they want to input Japanese characters. In another exemplary embodiment, Japanese Hiragana or Katakana letters 136 may be disposed on the top cover 128 of the key top 130 .
Referring to FIGS. 2A-2B , the upper housing 110 of the notebook PC 10 may further include a back cover 210 and a backlight 220 for the LCD 114 . The back cover 210 may include an interior surface 240 and an exterior surface 230 . The upper housing 110 may comprise a plurality of micro perforations 212 disposed to extend from the interior surface 240 to the exterior surface 230 . The plurality of micro perforations 212 may be arranged into a plurality of patterns. The plurality of micro perforations 212 may be arranged at different angles with respect to the backlight 220 or a plane of the exterior surface 230 of the upper housing 110 . In other words, a first set of micro perforations may be disposed at a first angle relative to the plane of the exterior surface and a second set of micro perforations may be disposed at a second angle relative to the plane of the exterior surface. A third set of micro perforations may be disposed at a third angle relative to the external plane of the housing. Therefore, when viewed from a first viewing angle, the user may see, for example, light passing through the first set of micro perforations. When viewed from a second viewing angle, the user may see, for example, light passing through the second set of micro perforations. When viewed from a third viewing angle, the user may see, for example, light passing through the third set of micro perforations.
At least a portion of the plurality of micro perforations 212 may include one or more various translucent particles, such as resins 214 , for example. The resins 214 inside the micro perforations may be selected to have different optical characteristics such that, when the backlight 220 emits light rays through the resins inside each of micro perforations, users may see various colors of light rays coming out of the micro perforations.
In operation of an exemplary embodiment, FIGS. 2B-2D show the upper housing 110 being opened at different angles comparable to the lower housing 120 . A logo pattern 290 on the back cover 210 of the upper housing 110 may change in designs or colors when the user rotates the upper housing 110 relative to the lower housing 120 .
Referring now to FIGS. 2E-2G , an exemplary animation effect provided across the back cover 210 is shown according to an exemplary embodiment of the present invention. A logo 290 may be positioned statically on the back cover 210 . As the back cover 210 is viewed at different angles by the viewer (for example as described with reference to FIGS. 2B-2D ), a graphic (for example a stripe) may first back light an area of the back cover 210 including the logo 290 ( FIG. 2E ). As the viewing angle changes, the backlighting may move the graphic over the logo 290 ( FIG. 2F ) and may appear to move across the back cover 210 until the graphic is no longer on the logo 290 ( FIG. 2G ).
Although the use of a micro perforated and backlit display is quite aesthetically pleasing to a user, there is typically no perceptible display or item when the light source is turned off. Although this may be preferable for some applications, it may be desirable for the backlit display item to be seen in some way even when the light source is turned off. For example, a logo or other trademark may be an item that a manufacturer might want on display at all times. Of course, a wide variety of other instances may also exist, such as advertisements, disclaimers, and other texts, for example. In such instances, it is desirable that the micro perforated and backlit display have alternative display capabilities when the backlight source is turned off. For example, the resins 214 inside the micro perforations may be replaced by fluorescent or phosphorescent dyes that may glow in the dark.
It should be understood, of course, that the foregoing relate to exemplary embodiments of the invention and that modifications may be made without departing from the spirit and scope of the invention as set forth in the following claims.
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A computer system, a display system, a method of graphic illumination is provided to give a user an improved appearance, functionality, and aesthetics. A display system may comprise a housing, a light source, and a plurality of micro perforations. The housing may have an interior surface and an exterior surface. The light source may be located within the housing. The plurality of micro perforations may be disposed to extend from the interior surface to the exterior surface of the housing. The plurality of micro perforations may pass through the housing at different angles with respect to a plane of the exterior surface of the housing.
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FIELD OF THE INVENTION
This invention relates to a method and apparatus to deliver both heat and moisture to a web of paper and more particularly to a method and apparatus for atomizing water with steam to improve the production and paper qualities of a papermaking machine.
DESCRIPTION OF THE PRIOR ART
In the modern production of paper, a continuous fiber/water slurry is formed as a moving web on a paper machine. As the slurry moves down the paper machine the water is removed to leave the fiber which forms the paper sheet.
The paper machine has several sections. The first section drains the water under the influences of gravity and vacuum on the Fourdrinier table. After the Fourdrinier table a web is produced with sufficient strength to be self-supporting to feed itself into a second or press section.
The second section of the paper machine presses the paper web and squeezes the water from the sheet. This section typically consists of a series of rolls forming press nips through which the paper web is fed. After pressing removes all the water that it can, the remaining moisture in the web must be evaporated.
The third section of the paper machine, normally referred to as the dryer, evaporates the remaining moisture in the paper web down to the final level desired for the grade of paper being produced.
At the end of the paper machine is a calender that adds gloss and smoothness to the paper surface. If the paper surface requires higher gloss and smoothness than that which can be achieved by the normal on-machine calendering then off-machine supercalendering is further applied to the paper surface.
During the production of paper it is important that a consistent quality be produced and maintained. The moisture profile in the cross-machine direction (CD) is one of many important qualities of paper products. It is not only important that the overall moisture level be controlled, but also that the moisture distribution throughout the sheet be controlled both in the direction that the sheet is moving known as the machine direction (MD) and in the CD. Variation in moisture content of the sheet will often affect paper quality as much or even more than the absolute moisture content.
There are numerous influences on the paper machine that can cause variation of the moisture content especially in the CD. Wet or dry edges and characteristic moisture profiles are common occurrences on paper machines. As with the moisture content of the sheet, similar problems exist for sheet gloss profile and smoothness distribution in the CD. Thus a number of profiling systems have been developed to offer control of the paper quality during paper production.
Steam showers are conventional profiling systems that work by selectively delivering steam onto the paper web during production. Profiling steam showers deliver a variable distribution of steam in zones across the paper web. The amount of steam passing through each zone of a steam shower is adjusted through an actuator located in that zone.
Steam showers are widely used on the Fourdrinier table to help drainage and increase production. In the press section, steam is added before the press nips to increase the temperature of the web. The added temperature makes the water removal by pressing much more effective as the added moisture removal is much greater than the added moisture due to steam condensation. Profiling steam showers are also used in the calendering process to improve gloss and smoothness of the paper products.
Moisture spray systems are also conventional profiling systems normally used in the evaporating sections of paper machines. The water spray systems are designed to apply a profile of moisture spray in the cross-machine direction to counter an undesirable moisture profile in the paper web. These systems consist of a series of flow-controlling actuators capable of independently adjusting the amount of spray in discrete adjacent zones in the CD.
In addition to the actuator, another key component in moisture spray systems is the spray nozzle. The nozzle is the device that breaks the water particles into fine droplets. These nozzles typically use a separate air pressure line to produce the droplets.
Steam showers basically add moisture and heat to the web by impinging hot steam on to the surface of paper. The latent energy in the steam is released when steam condensation occurs on the paper surface, and causes the web temperature to rise. Steam condensation continues until a certain temperature on the paper surface is reached. Higher web temperature implies less viscosity of the moisture, and consequently less resistance to the dewatering of the press section. It is the added heat that contributes to the improvement of machine runnability and efficiency, and consequently to the increase of the paper production.
Profiling steam showers are also used to improve moisture content in the web. However the resulting benefits are limited due to the capability of the paper sheet to condense steam on to its surface. As mentioned before, steam will not condense on the paper surface if the surface temperature is too high, instead it bounces back into the environment and is wasted.
Water spray systems directly add moisture to the paper surface to improve the moisture profile. Before spraying water to the web, the water is normally heated to the temperature of the web to prevent any by-effects due to the temperature disturbance. Compared to steam shower systems, water spray systems have more freedom for moisture manipulation. However the water spray systems have limited effects on the temperature rise of the web. Therefore, water sprays are generally used for quality improvements while steam showers are used for improving both production and quality.
The apparatus and method of the present invention was developed in order to overcome the shortcomings of both steam showers and water spray systems. The present invention combines the advantages of steam showers with that of water spray systems. The method involves impinging a predetermined mixture of steam and spray on to the web for both production and quality improvement. The predetermined mixture contains carefully calculated moisture and heat for a specific application without the limits arising from only a steam shower or only a water spray.
The novel apparatus involves using existing actuator nozzle modules that are able to use steam to break water into fine droplets. The actuator controls the moisture content in the mixture. The heat of the mixture can be controlled by adjusting the steam pressure and the amount of superheating of the steam.
Typically, there are two types of actuators that can be used in the apparatus of the present invention. One converts a control signal to a linear movement. The linear movement is then employed to adjust proportionally an opening area in a valve mechanism. The flow amount passing through this valve is therefore controllable in a linear fashion by keeping the upstream flow pressure constant, and the varying opening area at the valve determines the flow rate.
The other actuator type is referred to as the regulator type. The regulator-type actuator regulates the flow pressure feeding a constant opening based on a controlling reference pneumatic pressure. The varying pressure feeding the constant orifice determines the flow rate.
The regulator-type actuator is especially effective for applications requiring small flow control. It can be appreciated that precisely adjusting the opening of a small orifice is very difficult. Thus it is much easier to keep the opening of the small orifice untouched while regulating the flow pressure feeding that orifice. Another advantage of the regulator type actuator is its capability to fully close the valve when needed. Therefore the regulator-type actuator is used for the novel apparatus of the present invention because of its superior performance.
SUMMARY OF THE INVENTION
A method of wetting and heating webs of paper or other hygroscopic material. The method comprises:
(a) supplying a steam stream that is the combination of a swirling steam stream, one straight steam stream and another straight steam stream;
(b) providing a mixture of a liquid atomized by said supplied steam stream and said steam stream, said mixture having both moisture and heat; and
(c) absorbing in a web of hygroscopic material advancing across the mixture of said atomized liquid and said steam stream said mixture moisture and heat.
A method of wetting and heating webs of paper or other hygroscopic material using an atomizing nozzle. The method comprises:
(a) forming in the nozzle a steam stream that is the combination of a swirling steam stream, one straight steam stream and another straight steam stream;
(b) providing a mixture of a liquid atomized by said formed steam stream and said steam stream, said mixture having both moisture and heat; and
(c) absorbing in a web of hygroscopic material advancing across the mixture of said atomized liquid and said steam stream said mixture moisture and heat.
A method of wetting and heating webs of paper or other hygroscopic material. The method comprises:
(a) arranging at least first and second atomizing nozzles in an array wherein the at least first and second nozzles are adjacent to each other;
(b) forming in each of the at least first and second nozzles a steam stream that is the combination of a swirling steam stream, one straight steam stream and another straight steam stream;
(c) providing to each of said at least first and second nozzles a mixture of a liquid atomized by said formed steam stream and said formed steam stream, said mixture having both moisture and heat; and
(d) absorbing in a web of hygroscopic material advancing across the mixture of said atomized liquid and said steam stream said mixture moisture and heat.
A method of wetting and heating webs of paper or other hygroscopic material using an atomizing nozzle. The method comprises:
(a) creating an array of the atomizing nozzles;
(b) forming in each of the nozzles a steam stream that is the combination of a swirling steam stream, one straight steam stream and another straight steam stream;
(c) providing to each of said nozzles a mixture of a liquid atomized by said formed steam stream and said formed steam stream, said mixture having both moisture and heat; and
(d) absorbing in a web of hygroscopic material advancing across the mixture of said atomized liquid and said steam stream said mixture moisture and heat.
An apparatus for atomizing a liquid with steam. The apparatus comprises:
(a) a housing having a steam discharging outlet and a liquid discharging outlet aligned flush with each other;
(b) a first nozzle in the housing for producing at the steam discharging outlet and along a predetermined axis a steam stream that is the combination of a swirling steam stream, one straight steam stream and another straight steam stream;
(c) a second nozzle disposed in said first nozzle for producing at said liquid discharging outlet a controlled stream of liquid, said steam stream atomizing said stream of liquid external to said housing; and
(d) a steam stream divider disposed in the first nozzle and outside of the second nozzle, the steam stream divider maintaining the concentricity of the steam stream and the controlled liquid stream.
An apparatus for atomizing a liquid with steam. The apparatus comprises:
(a) a first nozzle for producing in the apparatus and along a predetermined axis a steam stream that is the combination of a swirling steam stream, one straight steam stream and another straight steam stream;
(b) a second nozzle disposed in the first nozzle for producing in the apparatus a controlled stream of liquid, the steam stream atomizing the stream of liquid external to the apparatus; and
(c) a steam stream divider disposed in the first nozzle and outside of the second nozzle, the steam stream divider maintaining the concentricity of the steam stream and the controlled liquid stream.
An apparatus comprising:
one or more nozzles, each of the nozzles atomizing a flow of liquid by a steam stream that is the combination of a swirling steam stream, one straight steam stream and another straight steam stream to thereby provide both moisture and steam to a web of hygroscopic material.
DESCRIPTION OF THE DRAWING
FIG. 1 shows a segment of the preferred embodiment for the steam water spray of the present invention.
FIG. 2 shows an actuator nozzle module that is used in the preferred embodiment of FIG. 1 .
FIG. 3 shows an embodiment for the regulator type actuator that is part of the actuator nozzle module of FIG. 2 .
FIG. 4 shows an embodiment for the nozzle portion of the actuator nozzle module of FIG. 2 .
FIG. 5 shows an enlargement of the stream divider of FIG. 4 for the steam-atomizing nozzle.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a segment of the preferred embodiment for the steam water spray system 1 of the present invention. System 1 consists of a plurality of actuator nozzle modules 10 mounted on a plate 6 across the paper web in the CD. A common water chamber 2 in sealed communication with a water supply unit (not shown) feeds pressurized water to each actuator nozzle module 10 through a hole (not shown) in the plate 6 . A water return pipe 5 recycles unused water back to a water tank (not shown) of the water supply unit. A common steam chamber 3 in sealed communication with a steam preparation system (not shown) feeds pressurized steam to each actuator nozzle module 10 through another hole (not shown) in the plate 6 . A remotely generated pneumatic signal of 6 PSIG to 30 PSIG sent through air tubes 4 controls the water volume flow passing through each actuator nozzle module 10 .
Referring now to FIG. 2 there is shown an embodiment for integrated actuator nozzle module 10 . Module 10 consists of an atomizing nozzle 22 and a regulator-type actuator 20 . Nozzle 22 includes a port 28 which is in sealed communication with the common water chamber 2 through the plate 6 of FIG. 1 . The port 28 receives pressurized water from the water chamber 2 and then feeds that water to the regulator type actuator 20 .
The actuator 20 regulates the water pressure between 0 PSIG and 24 PSIG feeding a pair of orifices 12 and 14 and a water nozzle 26 downstream of the orifices. The feeding pressure and the sizes of the orifices 12 and 14 and the water nozzle 26 fully determine the water volume flow through the module 10 .
There are two pressure ports 18 and 16 in the water passage. The pressure port 18 is located upstream of the pair of orifices 12 and 14 , while the other port 16 is linked to the space between the two orifices 12 and 14 . The pressure measurements at the two pressure ports 16 and 18 can, as will be described below, be used to monitor the status of the two orifices 12 and 14 and the water nozzle 26 .
Preferably, steam is feed into a channel 70 of the atomizing nozzle 22 through a port 30 which is in sealed communication with the common steam chamber 3 through the plate 6 of FIG. 1 . Steam in the channel 70 then splits into three streams: one stream through a circumferential gap 72 around the water nozzle 26 , another stream through a flat gap 76 adjacent to the nozzle exit, and yet another stream through two off-center orifices 86 . The separated streams then mix again in a mixing chamber 74 before emitting to the environment through an annulus 78 around the water nozzle 26 . Steam passing through the two off-centered orifices 86 in opposite directions creates a swirling component of the mixed flow in the mixing chamber 74 . This swirling component does not exist in conventional steam showers.
When the valve of the actuator 10 is fully closed, there is no water flow through the nozzle 22 and the actuator module 10 delivers only steam to the web. As is described below in connection with FIG. 3 which shows a preferred embodiment for the regulator type actuator 20 , a valve stem 46 which is attached to a piston 44 combined with a valve seat 48 forms a valve at the source water inlet.
The steam water spray system 1 of the present invention is superior to conventional steam showers, because of the added swirling component in the steam jet. The swirling movement allows the steam to easily penetrate the boundary layer formed by the air carried by the moving web. Improved contact between the steam and the paper surface increases the efficiency of the steam treatment.
When the valve of the actuator 10 opens, water passing the valve feeds into the water nozzle 26 . The steam jet emitting through the annulus 78 acts as atomizing fluid in this case. The use of the combination of three steam streams in the mixing chamber 74 before emitting steam to the environment results in a moisture distribution that is mostly suitable to the profiling applications. Another benefit of the three atomizing streams is that the resulting size of the water droplets are effectively appropriate for paper rewet application. It is found that the three-stream atomizing nozzle can produce averaged droplets as small as 50 microns.
Alternatively, a plurality of steam valves upstream of the port 30 (not shown) can be used to regulate the steam volume flow feeding the atomizing nozzle 22 . This configuration allows, as does conventional steam showers, temperature profiling across the web in the CD. However, the added water associated with the present invention extends the range of moisture manipulation of a conventional steam shower. The capability of regulating steam volume flow also adds size control to droplets produced by the atomizing nozzle. As is well known, the more the atomizing fluid flow, the smaller the droplets produced by an atomizing nozzle.
The steam atomizing of the present invention provides when compared to air atomizing benefits to the spray system. As is well known the large water volume flow for heavy grade paper requires more atomizing fluid flow to atomize the water. For a nozzle with fixed geometry, more atomizing flow indicates a higher atomizing pressure. It is much more expensive to compress air to a pressure higher than 15 PSIG, because of the difference in cost between the air blower that is capable of compressing the air up to 15 PSIG and the compressor needed to compress the air to pressures higher than 15 PSIG. However, steam with a pressure higher than 15 PSIG is readily available in any paper mill.
Another benefit of using steam to atomize water is the expected reduction in droplet size. Latent energy in the steam heats the atomized water and consequently reduces the viscosity of the water. Lower viscosity results in smaller resistance to the atomizing process and therefore smaller droplets in the spray.
The regulator-type actuator 20 of FIG. 2 is described in commonly owned U.S. Pat. No. 6,394,418 for “Bellows Actuator for Pressure and Flow Control”, the disclosure of which is incorporated herein by reference.
Referring now to FIG. 3 there is shown an embodiment for the regulator-type actuator 20 .
Actuator 20 consists of an internal chamber 32 and an external chamber 34 separated by a flexible metal bellows 36 . The external chamber 34 is the space formed by actuator body 40 , the bellows 36 , the end piece 42 and the piston 44 . The control air inlet 24 feeds into the external chamber 34 . The internal chamber 32 is the space formed by the water inlet end piece 42 , the bellows 36 and the piston 44 . The source water inlet 50 in sealed communication with the water port 28 of FIG. 2 feeds into the internal chamber 32 . A valve stem 46 attached to the piston 44 combined with a valve seat 48 forms a valve at the source water inlet 50 . A spray water outlet 52 directs the water to the double orifices 12 and 14 and the nozzle orifice 26 through the water inlet 62 of FIG. 4 .
Initial setup of the actuator 20 involves compressing the metal bellows 36 a predetermined amount and attaching the valve stem 46 such that the valve orifice 54 is closed at this pre-compressed setting. In addition, the water inlet end piece 42 and the piston 44 are designed to diametrically guide each other in their relative movement as well as act as an anti-squirm guide for the bellows 36 .
The actuator 20 works to control the pressure fed to the double orifices 12 and 14 and the nozzle orifice 26 using the pneumatic control air pressure at the port 24 as a reference. Source water is fed to the source water inlet 50 at a pressure in excess of the maximum desired pressure for the spray nozzle 22 . Control air is fed to the metal bellows 36 through actuator body 40 .
The air pressure in the external chamber 34 acts against the effective area of the bellows 36 and creates an operating force, which is resisted by three opposing forces. The first opposing force is formed by the spring action of the pre-compressed metal bellows 36 . The second opposing force is formed by the pressure of the source water acting against the relatively small area of the valve orifice 54 opening. The third opposing force is formed by the spray water pressure in the internal chamber 32 acting against the effective area of the bellows 36 . The first two reactive forces are substantially small or constant which allows changes to the control air pressure to predictably affect the pressure of the water feeding the double orifices 12 and 14 and the nozzle orifice 26 . The actuator 20 operates on a balance of these forces.
If the control air pressure is less than the kickoff pressure of 6 PSIG, determined by the amount of pre-compression of the bellows 36 , the valve stem 46 remains against the valve seat 48 and no water passes through the valve orifice 54 . The double orifices 12 and 14 and nozzle orifice 26 downstream receive no water pressure to feed them.
When the control air pressure exceeds the kickoff pressure of the actuator 20 , the valve stem 46 is pushed down by the piston and water flows through the valve orifice 54 into the internal chamber 32 and out to the double orifices 12 and 14 and nozzle orifice 26 . The double orifices 12 and 14 and the nozzle orifice 26 downstream allow water flow through it but also offer resistance to such flow. Thus the pressure in the internal chamber 32 builds.
As the pressure in the internal chamber 32 increases, the sum of the opposing forces increase until it matches the force of the control air pressure in the external chamber 34 . A balance point between control force and reactive opposite force results in regulated water pressure of between 0 PSIG and 24 PSIG, proportional to the pneumatic control pressure of between 6 PSIG and 30 PSIG. The regulated water pressure and the size of the double orifices 12 and 14 determine the flow rate passing through the actuator nozzle module.
A brief description of the mechanism of the actuator nozzle modules 10 is needed before one can fully understand how the actuator nozzle module 10 works. The atomizing nozzle 22 used in module 10 is described in U.S. patent application Ser. No. 10/001,408 (“the '408 Application”) filed on Oct. 22, 2001 for “Spraying Nozzle For Rewet Showers”, the disclosure of which is incorporated herein by reference. The atomizing nozzle 22 uses a combination of three air streams to break the water into small droplets and produce an appropriate moisture profile that is suitable for paper quality improvement applications.
Referring now to FIG. 4 , there is shown an embodiment for the nozzle portion 22 of the actuator nozzle unit 10 . The nozzle portion consists of a nozzle body 56 , a double orifice device 12 and 14 , a water nozzle tube 58 , a stream divider 82 and a steam cap 60 . The nozzle body 56 also serves as a mounting base for the actuator 20 . The source water inlet 28 on the nozzle body 56 is connected to the source water inlet 50 of FIG. 3 to the actuator 20 . The spray water outlet 52 from the actuator 20 of FIG. 3 is aligned with the regulated water inlet 62 on the nozzle body 56 . Water from the actuator 20 feeds into the water inlet 62 , passing through the double orifices 12 and 14 , and finally emits from the water nozzle 26 .
Atomizing steam feeds into the steam chamber 70 formed by the nozzle body 56 , the water tube 58 , the stream divider 82 and the steam cap 60 through the atomizing steam inlet 30 . The atomizing steam in the steam channel 70 is then separated into three different flow streams by using the cylindrical stream divider 82 an enlargement of which is shown in FIG. 5 . One of the streams passing through the holes 98 (shown in FIG. 5 ) drilled towards the central axis of the cylindrical stream divider 82 gets into the chamber 80 formed by the water tube 58 and the stream divider 82 . This stream then flows into the gap 72 between the divider 82 and the water tube 58 before it enters the mixing chamber 74 to form the first steam stream around the water tube 58 .
There are two flat surfaces 96 (shown in FIG. 5 ) machined from the cylindrical outer surface of the stream divider 82 and located on one end of the divider 82 . The two flat surfaces are located opposite to each other. Two steam channels 84 are formed between the two flat surfaces 96 on the stream divider 82 and the inner surface of the steam cap 60 . The two steam channels 84 are connected to the steam channel 70 . Atomizing steam in channels 84 are used for the second and the third streams.
The second steam stream passes through the two holes 86 drilled off-center on the two flat surfaces 96 of the stream divider 82 and flows tangentially into the mixing chamber 74 . The two off-centered holes 86 are aligned in opposite directions so that swirling flow is produced in the mixing chamber 74 around the first steam stream. The size of the two orifices 86 and the steam pressure in the channel 70 determine the strength of the swirl in the mixing chamber 74 . The swirl determines the spray pattern of the final jet, especially the width of the final jet.
The third steam stream is generated by atomizing steam in the two steam channels 84 passing through the gap 76 formed between the steam cap 60 and the steam divider 82 . A ring 88 is used to control the width of the gap 76 , and consequently the shape of the resulting spray profile. The third stream passes through the gap 76 , bends towards the chamfered surface 90 on the steam cap 60 due to the Coanda effect. The Coanda effect indicates that flow tends to attach to a solid surface. The third stream wraps the swirling flow and the first stream within it in the mixing chamber 74 . The combination of the three streams rushes out of the annulus 78 around the water jet emitting from nozzle orifice 26 .
There are several benefits associated with the design of the three-stream nozzle. One of the benefits is the efficiency of the atomizing nozzle. When the third stream bends at the chamfer 90 of the steam cap 60 , an area with low pressure is created near the chamfer 90 of the steam cap 60 also due to the Coanda effect. This low pressure in chamber 74 created by the third stream reduces the resistance on both the first steam stream and the swirling second stream. This reduction of the resistance indicates that exactly the same spray pattern (particle size and mass profile) that is created by the three air streams used in the atomizing nozzle described in the '408 Application can also be created with relatively low atomizing steam source pressure.
Another benefit of the atomizing nozzle design is that the design allows control of the two slopes of the water mass profile generated by the nozzle. The third stream which is a result of the design adds axial momentum to the outer region of the swirl that steepens the two slopes on the outer edges of the profile and makes the profile closer to an ideal square in shape.
Yet another benefit of the atomizing nozzle design arises from the additional shearing force produced by the mixing atomizing steam streams. Larger water particles in the swirl move away from the center of the jet faster due to the greater centrifugal force. The shearing force created in the mixing range of the third stream and the swirl breaks those particles into even smaller particles. The resulting spray has a more uniform particle size distribution across the whole profile.
Still yet another benefit of the nozzle design is also efficiency related. The swirl generated by the two off-centered holes 86 in the mixing chamber 74 is compressed in the convergent area formed by the chamfer 90 on the steam cap 60 . The tangential velocity in the swirl increases dramatically during the compression. The chamfer 90 of the steam cap 60 drags the tangential velocity to zero on the chamfer surface. The friction on the chamfer surface dissipates the strength of the swirl and causes inefficiency in the nozzle. The third stream located between the swirl and the chamfer surface acts as a cushion for the swirl and preserves the vortical strength of the swirl.
As was described above, the pressure measurements at ports 16 and 18 in the water passage (see FIG. 2 and FIG. 4 ) can be used to monitor the status of the flow control orifices 12 and 14 and water orifice 26 . This monitoring is described in U.S. Pat. No. 6,460,775, for “Flow Monitor for Rewet Showers” the disclosure of which is incorporated herein by reference.
The monitoring capability of this actuator nozzle unit 10 is achieved by pressure measurement at two pressure ports 16 and 18 of FIG. 2 . As is shown in FIG. 2 there is a pressure port 16 located right between the two orifices 12 and 14 . There is also another pressure port 18 upstream of the two orifices 12 and 14 that monitors the regulated water pressure from the actuator 20 included in the module 10 . The upstream pressure measured is compared with the pneumatic control pressure sent to the actuator 20 through port 24 . This comparison results in the performance diagnosis of the actuator 20 .
The pressure measured between the two orifices 12 and 14 in combination with the pressure measured upstream can be used to monitor the status of the double orifices 12 , 14 and the water orifice 26 . Orifice monitoring is achieved by using a double orifice technique. The double orifice technique is based on the fact that there is always a pressure drop when a moving fluid passes an orifice. The pressure change at port 16 between the orifices 12 and 14 is monitored over time comparing to the upstream pressure at port 18 . The pressure between the double orifices 12 , 14 should be a portion of the upstream pressure, and the ratio of the two pressures is a constant regardless of flow conditions, if there is no geometrical variation in the flow passage.
If the upstream orifice 12 of the double orifices is partially blocked, the measured pressure between the double orifices 12 and 14 will be lower than normal. A zero pressure measurement between the orifices 12 and 14 indicates full blockage at the upstream orifice 12 during normal operation. When wearing occurs to the upstream orifice 12 , increasing pressure should be expected between the double orifices 12 and 14 . Similarly, a blockage at the downstream orifice 14 or the water nozzle 26 resists the flow more and consequently a higher pressure should occur between the orifices 12 and 14 . When the downstream orifice 14 is fully blocked, the pressure between the two orifices 12 and 14 equals the upstream pressure. Downstream orifice wearing results in a pressure drop.
In short, a pressure drop between the orifices 12 and 14 indicates either blockage at the upstream orifice 12 or wearing downstream. Pressure increasing between the orifices 12 and 14 implies that there is either wearing at the upstream orifice 12 or blockage downstream. Although there is no way to tell which orifice has caused the variation in the measured pressure one should be able to conclude that it is time to change the orifices. The double orifices 12 and 14 can be designed as one component for easy replacement.
The nozzle orifice 26 , which affects the droplet size from the nozzle 22 , is the same for all applications. Orifice diameters of the double orifices 12 , 14 determine the maximum water flow capacity for each individual application. For most of the applications, the nozzle orifice 26 is much larger than the flow orifice diameter. Therefore the pressure drop through the water orifice 26 is substantially less than the pressure drop through any one of the two orifices 12 , 14 . A relatively large pressure value at the port 16 makes precise pressure measurement there easier. That is why the monitoring technique uses two orifices 12 , 14 instead of one in the design. In practice, the diameters of the two orifices 12 , 14 can be either identical or different.
It is to be understood that the description of the preferred embodiment(s) is (are) intended to be only illustrative, rather than exhaustive, of the present invention. Those of ordinary skill will be able to make certain additions, deletions, and/or modifications to the embodiment(s) of the disclosed subject matter without departing from the spirit of the invention or its scope, as defined by the appended claims.
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An apparatus and method to use steam to atomize water to produce a mixture of moisture and heat for application to the web of a paper machine for both production improvement and paper quality control. The method allows independent droplet size and heat control in the mixture, resulting in flexibility that can not be offered by conventional steam showers or water spray systems individually. In one embodiment the apparatus consists of a plurality of actuator nozzle modules which control the water volume flow feeding the nozzle through a pneumatic pressure signal. Pressurized steam feeding the nozzle is used to break the water into fine droplets. The resulting nozzle spray is a mixture of moisture in fine water droplets and steam vapor, and heat stored in the steam. Alternatively, a plurality of steam valves can be used to regulate the steam volume flow feeding each atomizing nozzle.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates, generally, to electronic musical instruments and, in preferred embodiments, to electronic musical instruments having the capability of detecting the amount of displacement of a pedal or of other movable members.
2. Description of Related Art
In electronic musical instruments, displacement sensors are used as sensors to detect the amount of displacement of, for example, a pedal.
Examples of prior methods for the detection of the amount of displacement are described below.
Method 1: This is a method in which, for example, a displacement sensor is configured with a rubber sensor that changes shape in conformance with the amount that a pedal is stepped on and a sensor sheet that is pressed by the rubber sensor as the rubber sensor changes shape. The resistance value of the sensor sheet changes in conformance with the area of the sheet that is pressed.
Method 2: This is a method in which the resistance value of a volume control changes in conformance with the amount that a pedal is stepped on.
The determination of the amount of displacement is possible with the use of any of the methods discussed above. However, in those cases where the displacement of a pedal is detected, the displacement sensor is required to have the durability to withstand the force that is repeatedly applied from the pedal over a long period of time. Each of the methods mentioned above has problems such as those described below.
In Method 1, when the rubber sensor is used over a long period of time and its shape is repeatedly changed in conformance with the stepping operation of the pedal, the rubber sensor becomes deformed in shape such that it becomes impossible to accurately detect the amount that the pedal has been stepped on.
In Method 2, when the volume control is used for a long period of time, the mechanical sliding portion is abraded and that becomes a problem.
SUMMARY OF THE DISCLOSURE
Therefore, it is an advantage of embodiments of the present invention to provide an apparatus and method for providing a displacement sensor that has superior mechanical durability and that can withstand use over a long period of time.
An embodiment of the present invention that achieves the object described above is characterized in that the displacement sensor is furnished with a sensor structure, such as a sensor sheet, for which the resistance value changes in conformance with the area that has been pressed and a coil spring that has a conical shape. The wider end of said conical shape is in contact with the previously mentioned sensor sheet and increases the area of pressing of said sensor sheet in proportion to the compression of the spring.
The coil spring with which an embodiment of the present invention is furnished possesses durability with respect to the compression force that is received from the object that is displaced. In addition, since the displacement sensor is furnished with a structure in which the mechanical rubbing portion that is the cause of abrasion is excluded, the mechanical durability is superior and long-term use is possible.
In addition, it is preferable that an embodiment of the present invention be one in which the above mentioned sensor sheet is furnished with a sheet material that possesses electrical conductivity and with an electrode pattern that is disposed opposite the previously mentioned sheet material and is formed by radial segments extending between the center of the sensor sheet and its periphery.
The direction over which the cone shaped coil spring presses the sensor sheet as the spring is compressed is from the outer periphery of the sensor sheet toward the center of the sensor sheet. The degree to which the spring presses the sensor sheet is in proportion to the compression of the coil spring. Since the electrode pattern described above is formed along the direction over which the spring presses the sensor sheet, the resistance value of the above mentioned sensor sheet changes with good efficiency due to the compression of the coil spring.
As has been explained above, an embodiment of the present invention is superior in mechanical durability compared to the displacement sensors of the past and can withstand use for a long period of time.
These and other objects, features, and advantages of embodiments of the invention will be apparent to those skilled in the art from the following detailed description of embodiments of the invention, when read with the drawings and appended claims.
BRIEF DESCRIPTION OF THE FIGURES
FIGS. 1 a and 1 b are oblique view drawings that show a first preferred embodiment of the displacement sensor of the present invention;
FIGS. 2 a and 2 b are drawings that shows the range in which, when the conical coil spring is compressed and changes shape, the printed resistor sheet is pressed and comes into contact with a substrate having a conductive pattern, such as a printed carbon substrate, due to the shape change;
FIG. 3 is a lateral drawing that shows a partial cross-section of the state in which the displacement sensor has been mounted in the pedal system of an electronic musical instrument;
FIG. 4 is a lateral drawing that shows a partial cross-section of the state in which the displacement sensor has been mounted between the upper cymbal and the lower cymbal of an electronic high hat cymbal;
FIGS. 5 a and 5 b are lateral drawings that show an enlarged cross-section of the state in which the displacement sensor is mounted between the upper cymbal and the lower cymbal;
FIGS. 6 a and 6 b are oblique view drawing that show a second preferred embodiment of the displacement sensor of the present invention;
FIGS. 7 a and 7 b are schematic drawings that show the state in which a portion of the resistive pattern of the base film has come into contact with the metal pattern on the obverse surface of the substrate; and
FIG. 8 is a drawing that shows the change in the distance between the contacted portions of the two locations shown in FIG. 7 that accompanies the increase in the portion of the conical coil spring that is pushed and impacted on by the base film.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the following description of preferred embodiments, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. It is to be understood that other embodiments may be utilized and structural changes may be made without departing from the scope of the preferred embodiments of the present invention.
An explanation will be given below regarding preferred embodiments of the present invention while referring to the drawings.
First, an explanation will be given regarding a first preferred embodiment of the present invention.
FIGS. 1( a ) and 1 ( b ) are oblique view drawings that show a first preferred embodiment of the displacement sensor of the present invention.
FIG. 1( a ) is an exterior oblique view drawing seen from diagonally above the displacement sensor 1 and FIG. 1( b ) is a disassembled oblique view drawing of the displacement sensor.
The displacement sensor 1 that is shown in FIGS. 1( a ) and 1 ( b ) comprises a conical coil spring 11 , a circular cushion sheet 12 , a sensor structure, such as circular sensor sheet section 13 , and a fixing frame 14 .
The fixing frame 14 has a cylindrical concave portion 14 e.
The sensor sheet 13 is configured with resistive material, such as the circular printed resistor sheet 131 , and a substrate having a conductive pattern, such as the circular printed carbon substrate 132 , on which the circular printed resistor sheet is superposed. On the printed carbon substrate 132 , there is a square shaped protuberant section 132 c and this is arranged such that, when the printed resistor sheet 131 is superposed on the printed carbon substrate 132 , the protuberant section 132 c extends beyond the printed resistor sheet 131 .
The printed resistor sheet 131 is made from a plastic and like materials, and a conductive ink such as carbon and the like is uniformly printed on the surface that faces the printed carbon substrate 132 .
There is a spacer 131 a between the printed resistor sheet 131 and the printed carbon substrate 132 , and it is arranged such that, when the two are superposed and the conical coil spring 11 is not compressed, there is no direct contact. The spacer 131 a is in the shape of a ring and is placed on the peripheral edge section of the printed resistor sheet 131 facing the printed carbon substrate 132 . Incidentally, the spacer 131 a may also be disposed in the center section in addition to the peripheral edge section of the printed resistor sheet 131 .
The printed carbon substrate 132 is a printed board on which two independent electrode patterns, the inner peripheral pattern 132 b and the outer peripheral pattern 132 a , which are formed with copper foil or other electrically conductive material, are disposed.
The inner peripheral pattern 132 b comprises a ring shaped pattern that is disposed in the center of the substrate 132 and a branch form pattern that extends in a radial shape from the outer periphery of the ring shaped pattern toward the outer periphery of the substrate 132 . In addition, in the midst of the branch form pattern, a linear pattern extends from the end section of the pattern that is located closest to the previously discussed protuberant section 132 c to the protuberant section 132 c and becomes the electrical terminal 132 e of the inner peripheral pattern.
Also, carbon or another electrically conductive material is printed on the surface of the inner peripheral pattern 132 b.
The outer peripheral pattern 132 a comprises a ring shaped pattern that is disposed on the outer periphery of the substrate 132 and a branch form pattern that extends from the inner circumference of the ring shaped pattern toward the center of the substrate 132 . The branch form pattern of the outer peripheral pattern 132 a is disposed between the branch form pattern of the inner peripheral pattern 132 b such that the former branch form pattern does not come into contact with the latter branch form pattern. The ring shaped pattern of the outer peripheral pattern 132 a is disconnected in one place near the protuberant section 132 c such that the pattern does not intersect with the terminal 132 e of the inner peripheral pattern. The linear pattern extends to the protuberant section 132 c from one end of this pattern that is disconnected and becomes the electrical terminal 132 d of the outer peripheral pattern. In addition, carbon or another electrically conductive material is printed on the surface of the outer peripheral pattern 132 a in the same manner as the inner peripheral pattern 132 b.
The printed carbon substrate 132 , the printed resistor sheet 131 , and the cushion sheet 12 are received in the concave portion 14 e of the fixing frame 14 in that order, the printed carbon substrate 132 received first. In addition, the conical coil spring 11 is set into the concave portion 14 e of the fixing frame 14 , the wider end 11 a of the conical coil spring 11 first, and the wider end 11 a of the conical coil spring 11 is in contact with the cushion sheet 12 .
With regard to the protuberant section 132 c of the printed carbon substrate 132 , when the substrate 132 is accommodated in the fixing frame 14 , the protuberant section 132 c is set into the notched section 14 c that is disposed in the outer wall of the fixing frame 14 , and by this means, the rotation of the substrate 132 within the fixing frame 14 is prevented.
In the displacement sensor that is shown in FIG. 1( a ), the attaching hole 1 a is disposed in a position that is concentric with the axis of the conical coil spring 11 . This attaching hole 1 a is a hole that passes through all of the components that are shown in FIG. 1( b ) in their accommodated state from top to bottom from the cushion sheet 12 through the fixing frame 14 .
The displacement sensor 1 is used in order to detect, for example, the displacement of a pedal. In this case, the displacement sensor 1 is mounted in a position that is between the pedal and the facing bottom plate. In addition, the bottom surface of the displacement sensor 1 is in contact with the bottom plate and the front end section of the conical coil spring 11 is in contact with the pedal. When the pedal is stepped on, the displacement sensor 1 is subjected to a compression force from the tip section 11 b of the conical coil spring 11 . The conical coil spring 11 is compressed and changes shape due to this compression force.
One portion of the conical coil spring that has been compressed changes shape. This portion presses and impacts on the cushion sheet 12 . A portion of the printed resistor sheet 131 that is below the cushion sheet 12 is pressed onto the printed carbon substrate 132 .
An advantage of using a cushion sheet 12 made of a elastic material such as rubber is, when a pressing force is applied to the surface of the cushion sheet 12 at one point, the pressing force spreads and is also transmitted to the area around the one point to which it was applied.
Since the conical coil spring 11 presses the printed resistor sheet 131 onto the printed carbon substrate 132 through the cushion sheet 12 , the force of the wire material of the conical coil spring on the printed resistor sheet 131 is made more uniform than if the sheet were directly pressed by the conical coil spring 11 . The pressing force that has been made uniform is transmitted to the printed carbon substrate 132 .
Due to the fact that a portion of the printed resistor sheet 131 is pressed onto the printed carbon substrate 132 , the conductive ink that has been printed on the surface of the printed resistor sheet 131 and the carbon that has been printed on the surface of the inner peripheral pattern 132 b and the outer peripheral pattern 132 a of the printed carbon substrate 132 come into contact.
At this time, the current that flows in the outer peripheral pattern 132 a passes through the carbon that has been printed on the surfaces of both patterns and the conductive ink that has been printed on the surface of the printed resistor sheet 131 and flows into the inner peripheral pattern 132 b . Accordingly, the carbon and the conductive ink through which the current passes become an electrical resistance between both patterns.
When the pedal is stepped on further, the compression that is applied to the displacement sensor 1 increases and the compression shape change of the conical coil spring 11 becomes greater.
When the compression shape change becomes greater, the portions of the printed resistor sheet 131 that up to that point have not been in contact with the printed carbon substrate 132 , are pressed onto the printed carbon substrate 132 . As a result, the current also flows through the portions that have newly come into contact and, since the width of the path for the current that flows from the outer peripheral pattern 132 a to the inner peripheral pattern 132 b becomes broader, the electrical resistance between the two patterns decreases. The value of the electrical resistance is transmitted to, for example, the control section of the electronic musical instrument (not shown in the drawing) and the like as the amount that the pedal has been stepped on.
FIGS. 2 a and 2 b are drawings that show the range in which, when the conical coil spring 11 is compressed and changes shape, the printed resistor sheet 131 is pressed and comes into contact with the printed carbon substrate 132 due to the compression shape change.
When the displacement sensor 1 is subjected to the compression force to the tip section 11 b of the conical coil spring 11 in a direction along the center axis of the conical coil spring 11 , the conical coil spring 11 changes shape. As the conical coil spring 11 compresses, it presses and impacts on the cushion sheet 12 that is shown in FIG. 1 .
FIG. 2( a ) is a lateral drawing that shows the shape of the conical coil spring 11 when the spring is pressed weakly by a small compression force P 0 that is applied to the tip section 11 b of the conical coil spring 11 , the shape of the conical coil spring 11 when the spring is pressed to a medium degree by a medium level compression force P 1 , and the shape of the conical coil spring 11 when the spring is pressed strongly by a large compression force P 2 .
FIG. 2( b ) is a drawing that shows the range in which the printed resistor sheet 131 , which had been isolated from the printed carbon substrate 132 by the spacer 131 a , is pressed onto and comes into contact with the printed carbon substrate 132 by the conical coil spring that is shown in FIG. 2( a ).
The S 0 that is shown in FIG. 2( b ) indicates the narrow range in which the printed resistor sheet 131 comes into contact with the printed carbon substrate 132 due to the conical coil spring 11 being pressed weakly by the small compression force P 0 . S 1 indicates the medium range in which the printed resistor sheet 131 comes into contact with the printed carbon substrate 132 due to the conical coil spring 11 being pressed at a medium level by the compression force P 1 , and S 2 indicates the wide range in which the printed resistor sheet 131 comes into contact with the printed carbon substrate 132 due to the conical coil spring 11 being pressed strongly by the large compression force P 2 .
Next, an explanation will be given of an example in which the displacement sensor 1 is used in order to detect the displacement of a pedal in the pedal system of an electronic musical instrument as a first utilization example of the present invention.
FIG. 3 is a lateral drawing that shows a partial cross-section of the state in which the displacement sensor 1 has been mounted in the pedal system 2 of an electronic musical instrument.
The pedal 22 of the pedal system 2 that is shown in FIG. 3 is supported by the bottom plate 21 so that it can swing and, together with this, is impelled upward by the compression coil spring 26 that has been disposed between the pedal 22 and the bottom plate 21 . The upper end of the compression coil spring 26 is fixed to the back surface of the pedal 22 , and the lower end of the compression coil spring 26 is supported through the intervening support plate 27 by the butterfly nut 25 that has been screwed onto the bolt 28 that has been disposed standing on the bottom plate 21 . When the butterfly nut 25 is turned by hand, the butterfly nut 25 moves in the vertical direction and the degree of compression of the compression coil spring 26 is adjusted by means of the position of the butterfly nut 25 , adjusting the operating weight of the pedal 22 .
The lower part of the shaft that is shown in FIG. 3 passes through the pass-through hole (not shown in the drawing) that has been disposed in the shaft fixing block 210 which has been further fixed to the fixed plate 29 that has been fixed to the pedal 22 , and the tube 211 that has been fixed to the lower surface of the shaft fixing block 210 and extends between the pedal 22 and the bottom plate 21 . In addition, the upper part of the shaft 23 is linked to the controlled section of the electronic musical instrument-(not shown in the drawing) that is operated by the pedal system 2 .
At this time, the displacement sensor 1 is mounted by being set in the pass-through hole 1 a in the protuberant section 21 a that has been disposed on the bottom plate 21 in a position that is opposite the plate 23 a that is attached to the lower end of the shaft 23 .
When the pedal 22 is stepped on, the plate 23 a on the lower end of the shaft 23 presses downward and pushes on the tip section 11 b of the conical coil spring 11 of the displacement sensor 1 . Since the conical coil spring 11 that is pressed by the tip section 11 b is compressed, the electrical resistance of the displacement sensor 1 changes. The value of the electrical resistance is transmitted to the control section of the electronic musical instrument (not shown in the drawing) as the amount that the pedal 22 of the pedal system 2 is stepped on.
The initial angle adjustment bolt 212 is furnished on the left part of the pedal system 2 of FIG. 3 and the fixed plate 29 , which is fixed to the pedal 22 , extends to the lower end of the initial angle adjustment bolt 212 . The height H of the pedal 22 is adjusted by turning the initial angle adjustment bolt and changing the height h of the head of the bolt.
In addition, the shaft fixing bolt 24 is furnished in the shaft fixing block 210 that is shown in FIG. 3 and presses the shaft 23 that passes through from the side fixing the shaft 23 . By changing the length L of the portion of the lower end of the shaft 23 that protrudes from the tube 211 , the amount of change in the electrical resistance of the displacement sensor 1 with respect to the change in the amount that the pedal is stepped on is adjusted.
With the displacement sensors of the past, as one example, a rubber sensor is used on the portion that is compressed by the plate 23 a on the lower end of the shaft 23 , and when used continuously for a long period of time and repeatedly compressed, there is a problem that the shape of the rubber sensor itself becomes deformed and there is a danger that it will become impossible to accurately detect the amount that the pedal has been stepped on. However, with the embodiment of the displacement sensor 1 of the present invention, since a coil spring that is durable with respect to compression and changes in shape in conformance with the degree to which it is compressed is used, the sensor can be used for a long period of time compared to the displacement sensors of the past.
Next, an explanation will be given of an example of the use of the displacement sensor 1 to detect the displacement of the cymbals of an electronic high hat cymbal as a second utilization example of the present invention.
FIG. 4 is a lateral drawing that shows a partial cross-section of the state in which the displacement sensor 1 has been mounted between, for example, the upper cymbal 37 and the lower cymbal 36 of the electronic high hat cymbal 3 .
The electronic high hat cymbal 3 is configured with the upper cymbal 37 , the lower cymbal 36 , the extension rod 34 , which is linked to the upper cymbal, the hollow shaft section 35 , which is linked to the lower cymbal, the spring 38 , which is set into the inside lower end of the hollow shaft section 35 , the stepping type pedal 31 , the joint 32 , which is linked to the extension rod 34 and the pedal 31 , and the legs 33 , which are linked to the hollow shaft section 35 .
The upper part of the extension rod 34 is linked to the upper cymbal 37 , the lower part is linked to the pedal 31 through the joint 32 , and connecting and detaching is repeated from the upper part of the upper cymbal 37 in conformance with the stepping operation for the pedal 31 . Incidentally, the linkage of the upper cymbal 37 to the extension rod 34 will be discussed later.
The hollow shaft section 35 comprises the upper hollow shaft 351 and the lower hollow shaft 352 , which has an inside diameter that is greater that the outside diameter of the upper hollow shaft 351 . The upper hollow shaft 351 is inserted into the lower hollow shaft 352 and the height of the lower cymbal 36 is determined by the depth to which the upper hollow shaft 351 is inserted into the lower hollow shaft. Incidentally, the joint section 352 a is disposed on the lower end of the lower hollow shaft 352 . The inside diameter of the joint section 352 a is made somewhat narrow and supports the spring 38 that is set inside from the bottom.
The lower section of the extension rod 34 passes through the upper hollow shaft 351 and the lower hollow shaft 352 and, together with this, also passes through the spring 38 that has been set inside the lower hollow shaft 352 . Since due to the fact that the spring 38 is held between the lower surface of the joint section 34 a of the extension rod 34 and the joint section 352 a of the lower hollow shaft 352 , the extension rod 34 is always lifted upward, and when a stepping operation of the pedal 31 is not being carried out, the upper cymbal 37 and the lower cymbal 36 are separated at a prescribed interval.
FIG. 5 is a lateral drawing that shows an enlarged cross-section of the state in which the displacement sensor 1 is mounted between the upper cymbal 37 and the lower cymbal 36 .
FIG. 5( a ) is a lateral drawing in which the separated state of the upper cymbal 37 and the lower cymbal 36 are shown in cross-section, and FIG. 5( b ) is a lateral drawing that shows in cross-section the state in which, as a result of the upper cymbal 37 and the lower cymbal 36 having been brought into contact, the displacement sensor 1 is subjected to a compression force in the vertical direction, and the conical coil spring 11 of the displacement sensor 1 is compressed and changes shape. If the two cymbals are arranged in a different configuration, then the displacement sensor 1 may be subjected to a compression force in an accordingly different direction.
The upper felt washer 40 , the lower felt washer 39 , the upper nut 42 , the lower nut 41 , the fixing component 43 , and the securing bolt 44 , provided in order, link the upper cymbal 37 to the extension rod 34 .
The fixing component 43 is formed with the lower bolt 43 a extending on the lower surface of the upper block 43 b and-the pass-through hole 43 c is disposed in the center in order for the extension rod 34 to pass through. The upper nut 42 is screwed onto the lower bolt 43 a of the fixing component 43 until the nut connects with and is stopped by the upper block 43 b of the fixing component 43 . The lower bolt 43 a of the fixing component 43 is inserted through the pass-through holes that are disposed respectively in, from the bottom of the upper nut 42 , the upper felt washer 40 , the upper cymbal 37 , and the lower felt washer 39 . By additionally screwing the lower nut 41 onto the lower bolt 43 a from the lower side of the lower felt washer 39 , the upper cymbal 37 is fixed by the fixing component 43 .
The tip section 351 b of the upper hollow shaft 351 has the felt 45 held between the shaft bearer 351 a and the lower cymbal 36 is supported from the bottom by the upper hollow shaft 351 by the insertion of the shaft into the pass-through hole that is disposed in the center of the lower cymbal 36 .
The upper part of the extension rod 34 passes through center of the conical coil spring 11 of the displacement sensor 1 and the displacement sensor 1 attachment hole 1 a at the upper part of the upper hollow shaft 351 that supports the lower cymbal 36 and additionally, passes through the pass-through hole 43 c of the fixing component 43 with which the upper cymbal 37 is fixed. The tip section 11 b of the conical coil spring 11 of the displacement sensor 1 is in contact with the tip section 351 b of the upper hollow shaft 351 , and the bottom surface 14 d of the displacement sensor 1 is in contact with the lower end section 43 d of the fixing component 43 .
The upper block 43 b of the fixing component 43 with which the upper cymbal 37 has been fixed is furnished with the securing bolt 44 that presses the extension rod 34 that passes through from the side and fixes the extension rod 34 . The upper cymbal 37 is linked to the extension rod 34 through the fixing component 43 by means of the securing bolt 44 .
When the upper cymbal 37 , which is linked to the extension rod 34 by the fixing component 43 , moves downward in conformance with the stepping on the pedal 31 that is shown in FIG. 4 , the displacement sensor 1 is subjected to a compression force on the bottom surface 14 d from the lower end section 43 d of the fixing component 43 that moves as a single unit with the upper cymbal 37 . On the other hand, since the tip section 11 b of the conical coil spring 11 , which lies on the other end of the displacement sensor 1 , is in contact with the tip section 352 b of the upper hollow shaft 351 , which supports the lower cymbal 36 , and does not move, the conical coil spring of the displacement sensor 1 is compressed by the compression force that has been applied to the bottom surface 14 d of the displacement sensor 1 . The electrical resistance of the displacement sensor 1 changes due to this compression. The value of the electrical resistance is transmitted to the control section of the electronic high hat cymbal (not shown in the drawing) as the amount of displacement of the upper cymbal 37 of the electronic high hat cymbal 3 .
As has been explained above, the displacement of the upper cymbal in conformance with the stepping operation of the pedal 31 of the high hat cymbal 3 that is shown in FIG. 4 can be detected using the displacement sensor 1 of the present invention.
Incidentally, in those cases where the displacement sensor 1 is mounted on the electronic high hat cymbal 3 , since it is possible to attach the electronic high hat cymbal 3 and the displacement sensor 1 to an ordinary acoustic high hat stand without the addition of any other special components, in those cases where the user already possesses an acoustic high hat, an acoustic high hat stand can be used. Then, it is possible to plan for a reduction of the mounting expense.
Next, an explanation will be given regarding a second preferred embodiment of the present invention.
FIG. 6 is an oblique view drawing that shows a second preferred embodiment of the displacement sensor of the present invention.
FIG. 6( a ) is an exterior oblique view drawing seen from diagonally above the displacement sensor 5 and FIG. 6( b ) is a disassembled oblique view drawing of the displacement sensor 5 . The displacement sensor 5 that is shown in FIG. 6 here is furnished with the same conical coil spring and fixing frame as the conical coil spring 11 and fixing frame 14 with which the displacement sensor 1 that is shown in FIG. I is furnished but is furnished with components between the conical coil spring and fixing frame that are different from the components that are furnished between the conical coil spring 11 and the fixing frame 14 of the displacement sensor 1 that is shown in FIG. 1 . The displacement sensor 5 , except for the areas in which the components with which the sensor is furnished differ from those of the displacement sensor 1 that is shown in FIG. 1 , has a structure that is the same as that of the displacement sensor 1 that is shown in FIG. 1 . Therefore, for the components that are the same as the components of the displacement sensor 1 that is shown in FIG. 1 , (the conical coil spring 11 and the fixing frame 14 ), the same keys are assigned and shown in FIG. 6 , and an explanation of these components and that duplicates a structure that is equivalent to that of the displacement sensor 1 that is shown in FIG. 1 has been omitted.
The displacement sensor 5 that is shown in FIG. 6 is furnished with the base film 511 and the substrate 512 between the conical coil spring 11 and the fixing frame 14 . These two components comprise the sensor sheet 51 .
The base film 511 and the substrate 512 respectively have the protuberant sections 511 a _ 1 and 512 c and, when the base film 511 and the substrate 512 are accommodated in the fixing frame 14 , the protuberant sections 511 a _ 1 and 512 c are in a mutually superposed state set into the concave portion 14 e of the fixing frame 14 . Because of this, the base film 511 and the substrate 512 are prevented from turning in the fixing frame 14 and the relative positional relationships between the two are maintained.
The pressing film 511 b is furnished with the two bridge sections 511 b _ 1 and 511 b _ 2 along the center line of the circular plastic sheet 511 a . The pressing film 511 b , which is affixed to the circular plastic sheet 511 a , forms the thick convex portion of the pressing film 511 b on the conical coil spring 11 side surface of the base film 511 . When the conical coil spring 11 is compressed, a portion of the conical coil spring 11 pushes and impacts particularly strongly against the two bridge sections 511 b _ 1 and 511 b _ 2 and, as a result, the area below the portion of these two bridge sections 511 b _ 1 and 511 b _ 2 of the base film 511 that is pressed and impacted by the conical coil spring 11 is pressed strongly on the substrate 512 .
The conductive pattern 511 c is printed with a conductive ink such as carbon and the like on the substrate 512 side surface of the plastic sheet 511 a and is a ring shaped pattern that surrounds the attachment hole 1 a of the displacement sensor 5 .
The resistive pattern 511 d is a pattern in which a resistive material such as carbon and the like is printed superposed on the conductive pattern 511 c described above on the substrate 512 side surface of the plastic sheet 511 a . The resistive pattern 511 d is furnished with the branch shaped patterns 511 d _ 1 and 511 d _ 2 that faces the outer edge of the plastic sheet 511 a from the ring shaped pattern that is superposed on the conductive pattern 511 c under the two bridge sections 511 b _ 1 and 511 b _ 2 of the pressing film 511 b . When the conical coil spring 11 is compressed, a portion of each of the two branch shaped patterns 511 d _ 1 and 511 d _ 2 is pressed onto the substrate 512 through the above mentioned two bridge sections 511 b _ 1 and 511 b _ 2 .
The spacer film 511 e is affixed on the resistive pattern 511 d on the substrate 512 side surface of the plastic sheet 511 a . The two openings 511 e _ 1 and 511 e _ 2 are disposed in two locations in positions that correspond to the two branch shaped patterns 511 d _ 1 and 511 d _ 2 of the resistive pattern 511 d described above. When the conical coil spring is compressed, the two branch shaped patterns 511 d _ 1 and 511 d _ 2 are pressed onto the substrate 512 through the openings 511 e _ 1 and 511 e _ 2 in the two corresponding locations. However, it should be noted that, in a state in which the conical coil spring 11 is not compressed, the two branch shaped patterns 511 d _ 1 and 511 d _ 2 described above are separated from the substrate only by the thickness of the spacer film 511 e.
The substrate 512 is configured with a circular base material on which a metal pattern is disposed on both sides. On the spacer film 511 e side obverse surface, the two metal patterns 512 a and 512 b , which are mutually independent, are disposed in positions that correspond respectively to the two branch shaped patterns 511 d _ 1 and 511 d _ 2 of the resistive pattern 511 d . On the other hand, on the reverse surface, the two terminal patterns 512 d and 512 e, which extend to the protuberant section 512 c of the substrate 512 and form electrical terminals on the protuberant section 512 c , are disposed respectively below the two branch shaped patterns 511 d _ 1 and 511 d _ 2 described above. In addition, the two branch shaped patterns 511 d _ 1 and 511 d _ 2 described above are respectively conducted through by through holes not shown in the drawing to the corresponding terminal patterns 512 d and 512 e . When the conical coil spring 11 is compressed, a portion of each of the two branch shaped patterns 511 d _ 1 and 511 d _ 2 described above comes into contact respectively with the corresponding metal pattern 512 a and 512 b.
In the same manner as the displacement sensor of the first preferred embodiment discussed previously, the displacement sensor 5 of the second preferred embodiment also is used, for example, in order to detect the displacement of a pedal and the like. In this case, when the conical coil spring 11 is compressed by stepping on the pedal, as was discussed above, a portion of the resistive pattern 511 d of the base film 511 comes into contact with the metal patterns 512 a and 512 b on the obverse surface of the substrate 512 . At this time, when the current is conducted through the metal patterns 512 a and 512 b and flows between the terminal patterns 512 d and 512 e on the reverse surface of the substrate 512 , the current flows passing through the resistive pattern 511 d described above, the ring shaped pattern on the resistive pattern 511 d , and the conductive pattern 511 c described above that is printed on the plastic sheet 511 a on which the patterns are superposed. Accordingly, the resistive pattern 511 d and the conductive pattern 511 c through which the current passes become an electrical resistance between the terminal patterns 512 d and 512 e.
FIGS. 7( a ) and 7 ( b ) are schematic drawings that show the state in which a portion of the resistive pattern of the base film has come into contact with the metal pattern on the obverse surface of the substrate.
In FIG. 7( a ), the condition is shown in which, in a case in which the displacement sensor 5 is utilized to detect the displacement of, for example, a pedal and the like, the conical coil spring 11 is compressed by the pedal being stepped on, the base film 511 is pushed and impacted on by a portion of the conical coil spring 11 and, in addition, a portion of the base film 511 is pushed and impacted on by the obverse side of the substrate 511 through the openings 511 e _ 1 and 511 e _ 2 of the spacer film 511 e . By this means, as was discussed above, a portion of the resistive pattern 511 d comes into contact with the metal patterns 512 a and 512 b on the obverse surface of the substrate 512 .
In FIG. 7( b ), the two metal patterns 512 a and 512 b on the obverse surface of the substrate 512 and the resistive pattern 511 d , which is in contact with these metal patterns 512 a and 512 b , are shown. As discussed above, when the base film 511 is pushed and impacted on by the substrate 512 , a portion of each of the branch shaped patterns 511 d _ 1 and 511 d _ 2 of the resistive pattern 511 d come into contact, respectively, with the corresponding metal patterns 512 a and 512 b . In addition, the portions of the resistive pattern 511 d that are in between these two locations (excluding 511 d _ 5 ), the contact portions 511 d _ 3 and 512 d _ 4 , which are indicated by the diagonal lines in FIG. 7( b ), and the conductive pattern 511 c become an electrical resistance between the metal patterns 512 a and 512 b as well as between the terminal patterns 512 d and 512 e that are shown in FIG. 6 .
When the pedal described above is stepped on further and the conical coil spring 11 is further compressed, the portions of the resistive pattern 511 d that, up to this point, have not been in contact with the metal patterns 512 a and 512 b also are pressed on by the metal patterns 512 a and 512 b . As a result, the distance La+Lb between the two locations described above, the contacted portions 511 d _ 3 and 511 d _ 4 , is shortened and the value of the electrical resistance described above is reduced.
FIG. 8 is a drawing that shows the change in the distance between the contacted portions of the two locations shown in FIG. 7 that accompanies the increase in the portion of the conical coil spring that is pushed and impacts on the base film.
In FIG. 8 , the condition in which the conical coil spring 11 is weakly pressed with a small compression force P 0 and the base film is slightly pushed and impacted on by the conical coil spring 11 is shown. At this time, the portion that corresponds to the long distance La 0 +Lb 0 between the contacted portions described above of the resistive pattern 511 d (refer to FIG. 7 ) becomes the electrical resistance between the terminal patterns 512 d and 512 e that are shown in FIG. 6 and the value of the electrical resistance is large. In addition, when the compression force that is applied to the conical coil spring 11 is increased and becomes the medium level compression force P 1 , the base film is pushed and impacted on to a medium degree by the conical coil spring 11 and the value of the electrical resistance described above becomes a medium level value that is proportional to the medium level distance La 1 +Lb 1 shown in FIG. 8 . When the compression force that is applied to the conical coil spring 11 is increased and becomes the large compression force P 2 , a larger portion of the base film is pushed and impacted on by the conical coil spring 11 and the value of the electrical resistance described above becomes a small value that is proportional to the short distance La 2 +Lb 2 shown in FIG. 8 .
That is to say, when the displacement of a pedal such as that discussed above is detected by means of the utilization of the displacement sensor 5 , in the same manner as in the first preferred embodiment discussed previously, the value of the electrical resistance is transmitted to, for example, the control section of the electronic musical instrument (not shown in the drawing) and the like as the amount that the pedal has been stepped on.
The second preferred embodiment, in the same manner as in the first preferred embodiment discussed previously, is utilized to detect the displacement of the pedal of the pedal system 2 of an electronic musical instrument shown in FIG. 3 or to detect the displacement of the cymbal in the electronic high hat cymbal 3 shown in FIG. 4 and FIG. 5 and the like. However, with regard to these kinds of utilization embodiments for the second preferred embodiment described above, since they are the same as the utilization embodiments of the first preferred embodiment for which explanations were given referring to FIG. 3 through FIG. 5 , the duplicated explanations have been omitted.
In addition, as has been discussed previously, by means of the first preferred embodiment, advantageous results are that durability is increased with the use of a coil spring and that, when the displacement sensor 1 is installed in the electronic high hat cymbal 3 that is shown in FIG. 4 , the installation expenses are reduced. It need scarcely be said that advantageous results that are the same as these advantageous results can also be obtained by means of the displacement sensor 5 of the second preferred embodiment of the present invention.
Incidentally, in the above preferred embodiments, as illustrations of the sensor sheet of the present invention, an example in which a printed carbon substrate 132 and a printed resistor sheet 131 having as conductive ink such as carbon and the like printed uniformly on a strong plastic sheet such as polyester have been combined, and an example in which a substrate 512 having metal patterns disposed on both surfaces and a base film 511 having a resistive pattern 511 d printed on a plastic sheet have been combined were given. However, the sensor sheet in the embodiments of the present invention is not limited to these examples and, for example, a pressure sensitive printed resistor sheet in which the resistance value changes in accordance with the pressing force and the like may be used.
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An apparatus for detecting the displacement of a movable member of an electronic musical instrument. The apparatus has superior mechanical durability compared to displacement sensors of the past and can withstand long-term use. The apparatus includes a sensor that provides a detectable electrical characteristic having a value and a spring that, when compressed upon displacement of the movable member acts with the sensor, causing the value of the electrical characteristic to change. The value of the electrical characteristic represents the amount of displacement of the movable member and is used by a controller of the electronic musical instrument.
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PRIORITY CLAIM
[0001] This application claims priority from European patent application No. 06290555.9, filed Apr. 5, 2006, which is incorporated herein by reference.
TECHNICAL FIELD
[0002] An embodiment of the present invention relates to wireless communication systems using multi-antennas techniques, commonly referred to as Multi-Input Multi-Output techniques and noted MIMO.
[0003] More precisely, a first embodiment of the invention relates to a method of decoding a received signal function at least of a noise term matrix, of a channel matrix, and of a first and second symbols belonging to at least a signal constellation.
[0004] A second embodiment of the invention relates to a corresponding receiver.
BACKGROUND
[0005] Multi-antennas techniques have become very popular to increase the throughput and/or the performance of wireless communications systems, especially in third-generation mobile communications networks, in new generations of wireless local area networks like Wi-Fi (Wireless Fidelity), and in broadband wireless access systems like WiMAX (Worldwide Interoperability for Microwave Access).
[0006] In MIMO systems, transmitter Tx, as well as receiver Rx are equipped with multiple antennas. As illustrated in FIG. 1 , the transmitter Tx and the receiver Rx are both equipped, for example, with respectively a first and a second transmit antennas, Tx 1 and Tx 2 , and a first and a second receive antennas, Rx 1 and Rx 2 .
[0007] Among the numerous schemes proposed in the literature for transmissions using multiple antennas, spatial multiplexing model is one of the most popular ones which have been included in the specification of the WiMAX standard based on OFDMA (Orthogonal Frequency-Division Multiple Access).
[0008] In spatial multiplexing for transmission over two transmit antennas, Tx 1 and Tx 2 , a signal s is fed into the transmitter Tx, which performs, for example, coding and modulation to provide two independent complex modulation symbols: a first symbol s 1 and a second symbol s 2 . Each symbol belongs to a given signal constellation according to the modulation technique used, as well known by skilled in the art person. These two symbols, s 1 and s 2 , are then simultaneously and respectively transmitted on the first and second transmit antennas, Tx 1 and Tx 2 , during a time slot t corresponding to a given symbol period, through a channel defined by its channel matrix H. The transmit signal s can be expressed mathematically in a vector form, as it is exactly done for example in the WiMAX standard specification, as:
s = [ s 1 s 2 ] .
[0009] At the receiver side, the symbols are captured by the two receive antennas, Rx 1 and Rx 2 , and demodulation and decoding operations are performed. The received signal y, received during time slot t, can be theoretically expressed in matrix form as:
y = [ y 1 y 2 ] = [ h 11 h 12 h 21 h 22 ] [ s 1 s 2 ] + [ n 1 n 2 ] = Hs + n , ( 1 )
where:
y 1 and y 2 respectively represent the signals received on the first and the second receive antennas; n 1 and n 2 respectively represent the noise terms affecting the signals on the first and second receive antenna; and the coefficients h ij represent the propagation channel response (attenuation and phase) between the j th transmit antenna Txj and the i th receive antenna Rxi, j and i being integers.
[0013] To recover the transmitted signal s from the received signal y, the receiver Rx seeks, among all the possible transmitted symbols belonging to the signal constellation used at the transmitter side for the first symbol s 1 and the second symbol s 2 , the most probable transmitted signal ŝ given the received signal y.
[0014] Such a model is very general and encompasses in particular:
Single-carrier transmission using spatial multiplexing such as for instance the BLAST (Bell-Labs Layered Space-Time) system described in the article entitled “layered space-time architecture for wireless communication in a fading environment when using multi-elements antennas”, in Bell Labs Technology Journal, Autumn 1996, which is incorporated by reference. OFDM (Orthogonal Frequency Division Multiplexing) and OFDMA transmissions using spatial multiplexing in which case the model applies on a subcarrier per subcarrier basis; CDMA (Code Division Multiple Access) transmissions using spatial multiplexing in which case the model applies for instance after classical rake receiver.
[0018] Further, the description focuses on devices capable of receiving such spatially multiplexed signals.
[0019] Designing practical receivers for signals transmitted using the spatial multiplexing remains a real challenge. Indeed, designing an optimal receiver, that is to say a receiver minimizing the probability of decoding error on an estimated transmitted signal, is not trivial to be done in practice though its solution can be very simply stated: the most probable transmitted signal ŝ given the received signal y is the one minimizing the following Euclidean norm m(s)=∥y−Hs∥ 2 (2).
[0020] Let us note
s ^ = [ s ^ 1 s ^ 2 ] ,
where m(ŝ)=∥y−Hŝ∥ 2 is the minimum of the Euclidean norm m(s) and, ŝ 1 and ŝ 2 are respectively the most probable transmitted first and second symbols.
[0021] This minimization can theoretically be achieved by using the Maximum Likelihood (ML) method, which includes performing an exhaustive search over all the possible transmitted symbols belonging to the signal constellation, to find the most probable transmitted signal ŝ minimizing the Euclidean norm.
[0022] But this requires a receiver capable of testing M 2 symbols hypotheses, where M is the size of the signal constellation used at the transmitter Tx side for the first and second symbols s 1 and s 2 , and unfortunately, this becomes rapidly impossible or impractical due to the huge number of hypotheses to be tested. For instance, 4096 and 65536 hypotheses have to be tested for respectively a 64-QAM (Quadrature Amplitude Modulation) and 256-QAM constellations.
[0023] Several receivers have been proposed in the literature to try to solve this intricate problem at a reasonable complexity, yet all suffer from rather limited performance.
[0024] Among the most important ones, several receivers are based on interference cancellation approaches, or on iterative detection.
[0025] For example, the application US2005/0265465 concerning “MIMO decoding” and which is incorporated by reference, proposes a receiver which decodes iteratively the symbols sent via each transmit antenna. In each stage of processing, the receiver estimates a first symbol, removes the estimated first symbol of the received signal to give a first interference-cancelled received signal, soft-estimates a second symbol from the first interference-cancelled received signal, and provides a symbol estimate error term, for example by computing the probability of error in decoding the symbols. The decoding may be iterated a number of times.
[0026] But the performance of such a receiver is far from optimal since it is prone to error propagation phenomenon, and tends to increase the latency of the decoder since the decoder shall perform several decoding passes before providing an estimate of the transmitted signal.
SUMMARY
[0027] One embodiment of the invention is a method and a receiver exempt from at least one of the drawbacks previously mentioned. In particular, the proposed embodiment is substantially a method and a receiver capable of optimally receiving a spatially multiplexed signal with neither implementing an exhaustive search nor sacrificing optimality as in prior art techniques.
[0028] For this purpose, an embodiment of the invention is a method of decoding a received signal function at least of a noise term matrix, of a channel matrix, and of a first and second symbols belonging to at least a signal constellation.
[0029] The channel matrix comprises a first and a second columns, said first column comprising components representing the propagation channel response (attenuation and phase) between a first transmit antenna and at least a first and a second receive antennas, said second column comprising components representing the propagation channel response between a second transmit antenna and at least the first and second receive antennas.
[0030] A method according to an embodiment of the invention comprises at least the steps of:
selecting a set of possible values of the first symbol belonging to the signal constellation; for each selected value of the first symbol performing the steps of:
estimating the value of the second symbol using the value of the first symbol, to generate an estimated value of the second symbol given the first one; and calculating an Euclidean distance between the received signal and a virtually received signal defined by the first symbol with said selected value and by the second symbol with said estimated value;
selecting the minimal Euclidean distance among the Euclidean distances respectively calculated for the different selected values belonging to the set or a subset of said set; and selecting decoded first and second symbols as a function of the selected minimum Euclidean distance.
[0037] Therefore, the complexity of the method, according to an embodiment of the invention, is only linear in the constellation size rather than exponential.
[0038] The method can be used with different constellations, and with an arbitrary number of receive antennas.
[0039] The method may further comprise, before performing the step of estimating the value of the second symbol, at least the steps of:
calculating a first quantity equal to the complex conjugate of the second column multiplied by the received signal; calculating a second quantity equal to the complex conjugate of the second column multiplied by the first column; and calculating a third quantity equal to the complex conjugate of the second column multiplied by said second column.
[0043] Preferably, the step of estimating the value of the second symbol comprises at least the steps of:
generating an intermediate signal representative of the received signal in which the contribution of the first symbol is subtracted; and taking a decision on the value of the second symbol according to the intermediate signal.
[0046] For example, the decision on the value of the second symbol is taken by sending the intermediate signal to a threshold detector, which generates the estimated value of the second symbol according to the intermediate signal.
[0047] For example, the decision on the value of the second symbol is taken by using a look-up table to find the estimated value of the second symbol.
[0048] The set may include all the values of the first symbol belonging to the signal constellation.
[0049] The set may be selected inside a sphere belonging to the signal constellation, centered on the received signal and the radius of which is equal to a predefined value ρ.
[0050] The sphere may be such that |s 1 −ε 1 | 2 ≦ρ 2 l|l 22 | 2 , l 22 being the component of the last line and column of an upper triangular matrix obtained by performing at least a QR decomposition of the channel matrix, ε 1 being a component of a vector equal to the inverse of the channel matrix multiplied by the received signal, and s 1 being the value of the first symbol.
[0051] The first symbol may be defined by a plurality of symbolic bits, each symbolic bit being designated by its rank and being equal to 0 or 1.
[0052] The step of selecting the minimal Euclidean distance may be performed for a plurality of subsets, each subset including all the possible values of the first symbol in which the symbolic bit of a predetermined rank has a predetermined value.
[0053] The method may further comprise the steps of:
calculating a first soft symbol
s 1 soft = c 1 H y - c 1 H c 2 s 2 ML c 1 H c 1 , c 1 H
being the complex conjugate of the first column, and s 2 ML being the value of the second symbol corresponding to said estimated value;
calculating a second soft symbol
s 2 soft = c 2 H y - c 2 H c 1 s 1 ML c 2 H c 2 , c 2 H
being the complex conjugate of the second column, and s 1 ML being the value of the first symbol corresponding to said estimated value,
c 2 and c 1 being respectively the first and second columns, and y being the received signal.
[0056] Therefore, a method according to an embodiment of the invention may be implemented with a more reduced complexity by sacrificing optimality.
[0057] Another embodiment of the invention is a receiver implementing one or more of the embodiments of the methods described above.
[0058] Thus, spatially multiplexed signals may be received optimally, and a method being not iterative, it does not increase the receiver latency as iterative receivers do.
BRIEF DESCRIPTION OF THE DRAWINGS
[0059] Features and advantages of one or more embodiments of the invention will appear more clearly from the following description, given by way of example only, with reference to the accompanying drawings, wherein:
[0060] FIG. 1 is a diagram of a multi-antennas wireless communication system;
[0061] FIG. 2 shows a conceptual bloc diagram of a part of the receiver according to a first embodiment of the invention;
[0062] FIG. 3 shows a bloc diagram of another part of the receiver according to a second embodiment of the invention; and
[0063] FIG. 4 is a flow chart showing the general steps to be performed according to an embodiment of the invention.
DETAILED DESCRIPTION
[0064] In a wireless communication, in which receiver Rx and transmitter Tx are equipped, for example, with respectively two receive antennas Rx 1 , Rx 2 and two transmit antennas Tx 1 , Tx 2 , as illustrated in FIG. 1 , the receiver Rx contains a spatial multiplexer decoder that is capable of performing the detection of a spatially multiplexing signal.
[0065] To describe the spatial multiplexing decoding according to an embodiment of the invention, let
c 1 = [ h 11 h 21 ] and c 2 = [ h 12 h 22 ]
designate respectively a first and second columns of the channel matrix H.
[0066] With this notation, equation (1) can be rewritten as:
y=c 1 s 1 +c 2 s 2 +n (3);
and equation (2) becomes:
m ( s 1 ,s 2 )=∥ y−c 1 s 1 −c 2 s 2 ∥ 2 (4).
[0068] According to a first embodiment of the invention, and referring to FIGS. 2 and 4 , the complexity of the Maximum Likelihood (ML) receiver can be reduced by seeking the Maximum Likelihood (ML) estimate of the second symbol S 2 for each value of the first symbol s 1 belonging to the signal constellation, without having to make an exhaustive search.
[0069] This can be performed as follows: for each of the M possible values of the fist symbol s 1 , subtract the contribution of this first symbol to the received signal y, for example by computing:
r 2 ( s 1 )= y−c 1 s 1 (5).
[0070] This signal can be expressed in terms of second symbol s 2 as:
r 2 ( s 1 )= c 2 s 2 +n (6).
[0071] Thus, to make a decision on the second symbol s 2 , that is to say to estimate ( 02 ) the value of the second symbol s 2 from equation (6), we next compute an intermediate signal:
z 2 ( s 1 )= c 2 H r 2 ( s 1 )= c 2 H y−c 2 H c 1 s 1 (7),
where the superscript H denotes complex conjugate.
[0073] Equation (7) can then be expressed as:
z 2 ( s 1 )= c 2 H c 2 s 2 +c 2 H n=∥ c 2 ∥ 2 s 2 +c 2 H n (8),
[0074] The decision on the second symbol s 2 is made by sending the intermediate signal z 2 (s 1 ), for example, to a threshold detector Q, also called symbol detector or threshold comparator, as well known by skilled in the art person, to generate an estimated value of the second symbol s 2 according to the intermediate signal z 2 (s 1 ).
[0075] The decision on the second symbol s 2 can also be achieved by using a simple look-up table, though the invention is not limited to these particular implementations.
[0076] In this way, for each possible value of the first symbol s 1 , an estimated value of the second symbol s 2 knowing the value of the first symbol s 1 , is taken without having to perform an exhaustive search over all the possible values of the second symbol s 2 belonging to the constellation used to transmit the second symbol s 2 . This estimated value of the second symbol s 2 knowing the value of the first symbol s 1 is denoted as s 2 ML |s 1 in the following.
[0077] Once the estimated value s 2 ML |s 2 is determined for each possible value of the first symbol s 1 , the following metrics are calculated ( 03 ):
m ( s 1 ) = y - H [ s 1 s 2 ML ❘ s 1 ] 2 = r 2 ( s 1 ) - c 2 ( s 2 ML ❘ s 1 ) 2 . ( 8 )
[0078] Each metric corresponds to the Euclidean distance between the received signal y and a noiseless signal defined as the product of the channel matrix H by the symbol vector formed of the estimated value s 2 ML |s 1 and the corresponding value of the first symbol s 1 .
[0079] Finally, the receiver selects ( 04 , 05 ) the minimal Euclidean distance among the Euclidean distances calculated, and the most probable transmitted signal ŝ, denotes
s ^ = [ s 1 s 2 ML ❘ s 1 ] ,
defined by the estimated value s 2 ML |s 1 and the corresponding value of the first symbol s 1 , which minimize the Euclidean distance m(s 1 ) with respect to the M possible values of the first symbol s 1 .
[0080] It can be shown that such a receiver provides the same symbol estimation as the exhaustive search, though its complexity is not exponential in the constellation size, but linear or near linear. This way of reducing an exponential search as an enumeration over only one of the two dimensions is not a common mechanism and is one of the specificities of an embodiment of the invention.
[0081] Particularly, it is completely different of an iterative approach where the first symbol s 1 would be estimated using a suboptimal hard decision based on c 1 H y=c 1 H c 1 s 1 +n 1 , where n 1 =c 1 H c 2 s 2 +c 1 H n, and then subtracted to estimate the value of the second symbol s 2 using a second error prone hard decision based on c 2 H y=c 2 H c 2 s 2 +c 2 H c 1 (s 1 −ŝ 1 )+n 2 where n 2 =c 2 H n.
[0082] In a second embodiment of the invention, and with reference to FIG. 3 , rather than computing r 2 (s 1 ) according to equation (5) for each possible value of the first symbol s 1 and multiplying it by c 2 H to get the intermediate signal z 2 (s 1 ) as indicated by equation (7), the receiver first computes a first quantity u=c 2 H y calculated only once per symbol period and used in equation (7) for all possible values of the first symbol s 1 , and a second quantity v=c 2 H c 1 and a third quantity w=c 2 H c 2 , which are independent of the first and second symbols values, and which remain unchanged as long as the channel responses do not change.
[0083] Once these three quantities are calculated, the intermediate signal z 2 (s 1 ) is computed for each of the M possible values of the first symbol s 1 , where z 2 (s 1 )=u−vs 1 in this case.
[0084] The intermediate signal z 2 (s 1 ) is then used to determine the estimated value s 2 ML |s 1 of the second symbol as in the first embodiment.
[0085] The minimization on the first symbol s 1 of the metric m(s 1 ) can be equivalently performed, according to the first or the second embodiment, by minimizing:
m ′ ( s 1 ) = c 2 H ( y - H [ s 1 s 2 ML ❘ s 1 ] ) 2 ,
which can be easily obtained by using the third quantity w as:
m′(s 1 )=∥z 2 (s 1 )−w(s 2 ML |s 1 )∥ 2 , to reduces the receiver complexity.
[0087] The receiver may perform the same operations as in the first or second embodiment, but in the reverse order. Specifically, it cancels the contribution of the second symbol s 2 on the received signal y for all of the M possible values of the second symbol s 2 , multiplies the resulting signal r 1 (s 2 ) by c 1 H to get the intermediate signal z 1 (s 2 ) and then, it determines the best estimated value of the first symbol s 1 by sending the intermediate signal z 1 (s 2 ) to the threshold detector Q or by using the look-up table.
[0088] Actually, it can be shown that first and second embodiments give the same results, that is to say, the most probable transmitted signal
s ^ = [ s 1 ML ❘ s 2 s 2 ] = [ s 1 s 2 ML ❘ s 1 ]
is the same, whether the receiver is run one way or the other. This property can be exploited to minimize the receiver complexity when the constellations used for the first symbol s 1 and the second symbol s 2 are not of the same size. Indeed, when the transmitted constellations are different, the receiver can choose to perform the enumeration either on the first symbol s 1 or on the second symbol s 2 so as to choose the most favourable case to reduce the complexity.
[0089] In a fourth embodiment, if the receiver complexity remains too high, it is possible to reduce the complexity of the proposed receiver further by limiting the number of hypotheses tested during the enumeration of the first or second symbol to a number of values inside a sphere belonging to the constellation, centered on the received signal y and the radius of which is equal to a predefined value ρ. The sphere is, for example, a one-dimensional sphere which is simply an interval.
[0090] The first step of this reduced enumeration will thus be to perform a QR decomposition of the channel matrix H:H H H=R H R,where R is an upper triangular matrix:
R = [ r 11 r 12 0 r 22 ]
[0091] In this case, if we denote as:
ɛ = [ ɛ 1 ɛ 2 ] = H - 1 y ,
by noting that m(s)=∥y−Hs∥ 2 =(ε−s) H H H H(ε−s)=∥R(ε−s)∥ 2 , the enumeration over the second symbol s 2 can be limited to the values of the constellation that are such that |s 2 −ε 2 | 2 ≦ρ 2 /|r 22 | 2 , where the predefined value ρ is chosen according to the desired trade-off between performance and complexity. For large values of the predefined value ρ, all hypotheses will be tested and the receiver will be optimal, while for small values of the predefined value ρ, a smaller number of hypotheses are enumerated and the estimation may not be optimal.
[0092] The estimated value of the first symbol is, for example, calculated as in the first or second embodiment, with respect to the values of the second symbol belonging to the sphere.
[0093] It is also possible to use the same principle to limit the search when the first symbol s 1 is used for the enumeration by switching the column of the channel matrix H to get the matrix G=[c 2 ,c 1 ] and by computing its QR decomposition as G H G=L H L where L is upper triangular
L = [ l 11 l 12 0 l 22 ]
[0094] In that case, the enumeration over the first symbol s 1 may be limited to the constellation symbols for which is |s 1 −ε 1 | 2 ≦ρ 2 /|l 22 | 2 holds.
[0095] It is also possible to first compute the matrix L and R, and to perform the enumeration depending on the relative value of l 22 and r 22 . This suboptimal low-cost version of the receiver constitutes another embodiment of the invention.
[0096] In most communications systems, an error correcting code (ecc) well known by those skilled in the art, for example block code or convolutional code or turbo-code, may be used together with an interleaver to add protection on the bits of information to be transmitted, in order to improve the transmission reliability. Thus first and second symbols s 1 and s 2 are defined by a plurality of symbolic bits, according to the modulation used. Each symbolic bit is designated by its rank and is equal to 0 or 1. These symbolic bits represent the bits of information to be transmitted which have been for example coded, interleaved, and mapped.
[0097] The interleaver can either operate after the bit to complex symbol mapping (symbol interleaver) or before (bit interleaver).
[0098] The receiver can then be modified to directly provide metrics to a decoder using for example a Viterbi algorithm, as known by those skilled in the art.
[0099] In this case, in a fifth embodiment of the invention, according to one of the embodiments presented previously, the selection of the minimal Euclidean distance is performed for a plurality of subsets, each subset including all the possible values of the first symbol s 1 in which the symbolic bit of a predetermined rank has a predetermined value.
[0100] For example, let's consider that the first symbol is defined by a first and a second symbolic bits b 0 and b 1 .
[0101] In the case of bit interleaver, the bit metric, calculated by the receiver for a given value, for instance 0, of the first symbolic bit b 0 carried by the first symbol s 1 , can be obtained as:
m ( b 0)=min s1:b0=0 ∥y−Hs ∥ 2 ,
where the notation min s1:b0=0 indicates that the minimization is not performed on the set of all possible values of the constellation, but on a subset corresponding to first symbols such that the symbolic bit b 0 has value 0. The search can be performed based on the set of M metrics m(s 1 ) as:
m ( b 0)=min s 1 :b=0 m ( s 1 ).
[0102] The receiver also calculates the following bit metrics:
m(b 0 )=min s1:b0=1 ∥y−Hs∥ 2 , where the minimization is performed on a subset corresponding to first symbols such that the symbolic bit b 0 has value 1; m(b 1 )=min s1:b1=0 ∥y−Hs∥ 2 , where the minimization is performed on a subset corresponding to first symbols such that the symbolic bit b 1 has value 0; and
m(b 1 )=min s1:b1=1 ∥y−Hs∥ 2 , where the minimization is performed on a subset corresponding to first symbols such that the symbolic bit b 1 has value 1.
[0106] These four bit metrics are then fed to the decoder, to generate the transmitted bits of information.
[0107] Similarly, bit metrics can be obtained for symbolic bits carried by the second symbols s 2 as:
m ( b 0)=min s 2 :b0=0 m ( s 2 )
m ( b 0)=min s 2 :b0=1 m ( s 2 )
m ( b 1)=min s 2 :b1=0 m ( s 2 )
m ( b 1)=min s 2 :b1=1 m ( s 2 )
[0108] Similarly, in the case of symbol interleaver, the metrics for a given value of the first symbol s 1 or the second symbol s 2 , can be directly obtained as described in the first, second or third embodiment.
[0109] In a sixth embodiment of the invention, the receiver can also provide a first soft symbol
s 1 soft = c 1 H y - c 1 H c 2 s 2 ML c 1 H c 1
and a second soft symbol
s 2 soft = c 2 H y - c 2 H c 1 s 1 ML c 2 H c 2 ,
from which bit or symbol metrics could be easily derived by a skilled in the art person.
[0110] For example, s 2 soft and s 1 soft are respectively the estimated value of the second symbol and the corresponding value of the first symbol forming the most probable transmitted signal ŝ.
[0111] An embodiment of the invention also applies to systems with more than two receive antennas. In this case, the received signal may be expressed as:
y = [ y 1 ⋮ y N ] = [ h 11 h 12 ⋮ ⋮ h N 1 h N 2 ] [ s 1 s 2 ] + [ n 1 n 2 ] = Hs + n ,
where N is the number of receive antennas.
[0113] By changing the definitions of c 1 and c 2 to:
c 1 = [ h 11 ⋮ h N 1 ] and c 2 = [ h 12 ⋮ h N 2 ] ,
all of the steps of the embodiments described previously remain the same as for N=2.
[0115] From the foregoing it will be appreciated that, although specific embodiments of the invention have been described herein for purposes of illustration, various modifications may be made without deviating from the spirit and scope of the invention.
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An embodiment of a method for decoding a received signal function of at least a channel matrix H, and of a first and second symbols s 1 and s 2 belonging to a signal constellation. The method comprises the steps of:
selecting a set of values of the first symbol s 1 in the signal constellation; for each selected value of the first symbol s 1 :
estimating the value of the second symbol s 2 to generate an estimated value of the second symbol; calculating an Euclidean distance between the received signal and a noiseless signal defined by the first symbol with said selected value and by the second symbol with said estimated value; selecting the minimal Euclidean distance among the Euclidean distances respectively calculated for the different selected values of the set of possible values of the first symbol; and selecting decoded first and second symbols corresponding to the selected minimum Euclidean distance.
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This application is a continuation-in-part of application Ser. No. 08/133,009, filed Oct. 15, 1993, now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates to a compressed air dusting gun and more specifically, to a gun which includes a pressure discharge valve oscillating within a predetermined frequency range.
The application of compressed air for removal of dirt and cleaning purposes is a well known and extensively used technique. In order to produce a concentrated and controllable air jet, the usual design includes a pistol-like tool equipped with an oblong air nozzle and a built-in shut-off valve. The shut-off valve is manually operated via a pawl or similar trigger mechanism mounted in connection with the handle of the dusting gun. When the trigger mechanism is activated, a concentrated air jet is discharged through the nozzle and by pointing this air jet on the object to be cleaned, it is possible to loosen and blast off foreign matter, such as dust, earth, oily coats. The ability of the air jet to loosen old dirt and adherent coatings of various kinds depends on the dynamic pressure exerted by the jet, i.e. primarily the jet velocity. The greater the velocity, the better the cleaning effect.
However, the jet velocity is limited to the available air pressure source, usually on the order of 6 bar, and consequently, an increase in the cleaning effect can only be achieved by increasing the air flow. Especially for the purpose of removal of adherent thick accumulations, the air consumption may easily be disproportionately large and the cleaning method therefore uneconomical.
DE Publication No. 1,099,760 (Odendahl) describes a known dusting gun for compressed air which consists of a valve designed with a longitudinally displaceable oblong valve body whose one end is in sealing contact against a valve seat shutting off the air flow through the gun under the influence of a compression spring, and whose other end is embodied as a piston, which is displaceably inserted into a closed cylinder. One side of the piston is in contact with the air duct in the dusting gun downstream of the valve via a longitudinal bore through the valve body and whose other side is in connection with the pressure side upstream of the valve through an adjustable regulator. The inlet to and the outlet from the dusting gun are shaped as a Laval nozzle. The regulator may be adjusted so that the movement of the piston is in resonance with the natural frequency of the pressure column in the system.
This known dusting gun is complicated in its construction. It is difficult to adjust and the velocity of the air is oscillating in a region from somewhat below to somewhat above the Mach region.
SUMMARY OF THE INVENTION
It is a purpose of the present invention to describe a blast gun for compressed air without the drawbacks of known prior art which is simple in construction and which has a high cleaning effect and high efficiency. According to the invention, this is achieved by designing the dusting gun as described and claimed hereinafter.
The dusting gun of the invention employs an oscillating shut-off valve with the effect that the compressed air, instead of being ejected as a continuous air jet through the nozzle, is divided into a series of short pressure pulses, more specifically, a pulsating air stream with periodically repeated pressurized discharges. These periodical pressure discharges, by way of example with frequencies in the range of 2-50 Hz, involve a time related concentration of the pressure energy of the air so that the peak value of the dynamic pressure of the air in each individual pulse is increased as compared to the dynamic pressure that would be achieved if the same volume of air is ejected continuously through a nozzle. The dynamic pressure in the air jet determines the ability of the air to loosen adherent accumulations from the surface to be cleaned.
In addition to the greater dynamic pressure, it has been discovered that the pulsating air jet also has the effect of setting the impurities in vibrating motion under the influence of the air pulses. In the case of certain types of impurities and coats, practice has shown that this effect contributes to increasing the cleaning action of the dusting gun as the vibrations cooperate in loosening the substances so that the cleaning operation is much faster, more thorough, and more economical with regard to the consumption of compressed air. The dusting gun according to the invention is therefore able to replace traditional high pressure continuous flow cleaning or water-based jet cleaning, with the advantages this entails, both with regard to economy and environmental protection.
According to the invention, the piston seal is made of Teflon® brand PTFE or a similar material and further in accord with this design, the sealing arrangement satisfies the demand for low friction and ease of valve actuation. An expedient measure is the manufacture of the valve seat or the valve body itself with a rubber or other elastic coating, such as polyurethane or synthetic rubber, with a view to reduce noise level and to assure long life of the valve.
The dusting gun, according to the invention, can, like any ordinary compressed air dusting gun, be combined with an ejector for the supply of liquid or granular material together with the air. The combination of pulsating compressed air and an additive consisting of a granular agent for cleaning or a liquid cleaning solution provides a significant increase in the cleaning result. This option is proposed for special cases where a significant increase in cleaning efficiency is demanded.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view of a compressed air dusting gun according to the invention;
FIG. 2 is an enlarged cross-sectional view of a jet nozzle of the dusting gun taken along the lines II—II of FIG. 1;
FIG. 3 is an enlarged longitudinal cross-sectional view of the oscillatory shut-off valve of the dusting gun taken along the lines III—III of FIG. 1;
FIG. 4 illustrates a modification of the invention with a nozzle pipe for use with the addition of a liquid simultaneously supplied with the compressed air;
FIG. 5 illustrates a further modification of the invention with a nozzle pipe intended for sand blasting;
FIG. 6 is a side elevational view of a nozzle pipe with accommodations for two different liquids supplied simultaneously with the compressed air.
DETAILED DESCRIPTION OF THE INVENTION
In the embodiment shown in the drawing FIG. 1, the dusting gun consists essentially of a handle section 1 in the form of a pistol grip with a trigger lever 2 and trigger guard 3 , an extension barrel 4 , and an exchangeable nozzle pipe 5 . The cross-section of the nozzle pipe has an exchangeable nozzle bit 6 . The nozzle bit is shown separately in FIG. 2 . The handle section 1 extends in a longitudinal direction and contains a shut-off valve, not shown in detail, which is opened by operating the trigger lever 2 , and an oscillatory pressure discharge valve. The pressure discharge valve is built into the portion of the handle section 1 a . The air connection to the dusting gun takes place through a coupling 7 . The nozzle pipe 5 is mounted on the extension barrel 4 by means of a knurled pipe union nut 8 .
FIG. 3 is a cross-sectional view of the oscillatory pressure discharge valve showing the structure in detail. The components of the pressure discharge valve are the portions of handle section 1 a , forming a cylindrical housing and a seat portion 1 b , valve stem having a seat 9 , at one end of valve body 10 . The valve body is embodied in the shape of an oblong, rotationally symmetric body portion extending in a longitudinal direction. The forward end of the valve body is formed as a cone-shaped part 11 with a tight fit against the seat 9 . A rubber coating 11 a is vulcanized onto the cone-shaped part 11 . The opposite end of the valve body 10 includes a piston 12 which is mounted in cylinder 13 . Between the piston 12 and the cone-shaped part 11 , the valve body consists of an oblong cylindrical shaft portion 14 .
A longitudinal bore in the valve body 15 serves to connect the portion 13 a of cylinder 13 to an air duct 16 having a generally cylindrical cross-section and thus to the extension barrel 4 and the nozzle pipe 5 . The valve body is held close in its seat by a compression spring coil 17 inserted in the cylinder 13 behind the piston 12 and a rear portion of the cylinder.
The portion 13 b of the cylinder in front of piston 12 is connected via an eccentrically positioned longitudinal bore 18 to an air chamber 19 which is located behind the valve stem and thus on the pressure side. The direction of flow through the shut-off valve is shown with arrows 20 .
The piston 12 of the valve body is fitted with a low-friction sealing ring composed of a Teflon® brand PTFE disk 21 and an O-ring 22 . The O-ring serves as a supporting disk for the Teflone® ring which, through its contact against the cylinder wall, ensures a tight fit of the piston. Valve dimension, size and weight of the valve body, spring characteristics, the flow duct's cross-sectional area, etc. are configured so that the desired oscillatory effect is self generated immediately on the opening of the air flow, i.e. by activation of the trigger lever 2 .
The mode of operation of the oscillating shut-off valve is as follows. In the normal starting position, the valve body is held against the valve seat in its closed sealing position by the coil spring 17 . When compressed air is admitted, the pressure is increased on one side of the piston and when the pressure exceeds the spring force, the valve opens which results in a momentary discharge of compressed air and a drop in the pressure. The valve closes again under the influence of the spring 17 and the cycle is repeated. Oscillation continues as long as compressed air is admitted to the valve. The valve thus causes an automatic alternating opening and closing, under the influence of the static and dynamic pressures of the compressed air, of the passage of air in the dusting gun.
The oscillation action of the valve body presupposes a suitable balanced condition between the valve dimension, the mass of the valve body (the moving mass) and the characteristics of the spring. It is also essential that the valve body move freely, i.e. with low friction. The oscillation frequency depends on these factors in combination with the pressure of the compressed air. Frequencies in the range of 2-50 Hz have been tested and found effective for cleaning applications.
During the oscillatory motion of the valve body, the passage of the compressed air through the valve seat is opened and closed and this gives rise to the desired air pulses with cyclically repeated pressure discharges. The pressure impacts from the pressure discharges are transmitted through the valve seat and through the extension barrel 4 , the nozzle pipe 5 , and the nozzle 6 .
By exchanging the nozzle pipe 5 , the dusting gun can be fitted with ejectors of various kinds. FIG. 4 shows a conventional device for combining a mixture of air and liquid. The liquid is supplied via a hose 23 . The nozzle pipe of the dusting gun is designated 24 .
The device for combining the moisture alternatively serve as a means for drawing from a supply of liquid by suction. The liquid will then be drawn into the device from a reservoir (not shown) by normal vacuum effect when compressed air is directed through the nozzle.
Thus, it is contemplated that the volume of liquid, for example, water, is adjustable from a minimum (zero) and upwards to a predetermined maximum in such a way that the ejector can preferably function by the injector effect proper, i.e. self-priming, and alternatively, by a supply of liquid at a positive pressure which is generated by a pump or a pressurized reservoir.
Both as a device for combining and as an ejector, the quantity of liquid is adjustable by means of a flow restriction valve positioned at the intake opening of the ejector nozzle. The flow restriction valve is operated via a finger union nut 23 a.
FIG. 5 illustrates an ejector for use in sand blasting. The sand is drawn into the nozzle by the ejector through a tubular lance 25 . By regulation of the suction air through the suction hose, the flow of sand can be regulated to meet actual needs. Regulation is done by means of an air flow valve (volume regulation valve) 25 a built into the upper end of the sand supply lance 25 .
FIG. 6 depicts in side elevation a device 26 which, in addition to an air admission conduit 27 , has two additional connectors 28 and 29 for admixture of water and liquid chemicals, respectively. This design makes it possible to mix air, water and chemicals, as needed. This combination is useful in connection with jobs requiring disinfection or the addition of solvents for cleaning grease.
The device 26 can be used in the following combinations:
1) air only (both liquid intakes are plugged or otherwise closed),
2) air and adjustable volume of water,
3) air and adjustable volume of water and adjustable volume of chemicals,
4) air and adjustable volume of chemicals,
5) air and water soluble chemical and adjustable chemical,
6) air drying after cleaning with water/chemicals.
Further, the ejector may include a built-in control valve for the liquid designed for activation, i.e. opening, under the influence of the air pressure in the ejector and nozzle, when the dusting gun is activated by pressing on the trigger.
A series of tests have been carried out with the blast gun according to the invention.
Upstream the blast gun 1 and upstream the nozzle 6 manometers, A and B respectively, for measuring the static pressures were connected. Further, the air consumption was measured.
The tests were carried out with different lengths of the extension barrel 4 , with a 6 mm diameter nozzle, with a 10 mm diameter nozzle, and without a nozzle.
On the following page, Exhibit A, shows the results from one of the tests. The cleaning effects are calculated as the kinetic energy, ½ mv 2 , of the air at the nozzle 6 .
EXHIBIT A
Cleaning
Access pressure A
pressure B
Air consumption
effect
p 1 bar
p 2 bar
m 3 /min.
KW
a. Length of barrel 4: 100 cm
Diameter - - 4: ⅜″
Diameter - nozzle 6: 6 mm.
6.0
2.48
1.20
2.41
7.0
3.32
1.49
6.36
8.0
4.34
1.80
14.72
b. Length of barrel 4: 100 cm
Diameter - - 4: ⅜″
Diameter - nozzle 6: 10 mm.
4.9
1.13
1.99
5.10
c. Length of barrel 4: 100 cm
Diameter - - 4: ⅜″
Nozzle removed.
4.0
0
1.89
≈0
The invention is not limited to the above shown and described embodiment. Other types of oscillatory pressure discharge valves are also possible. The primary purpose of the invention is the conversion of the static energy of the compressed air into a pulsating, concentrated air jet with high dynamic energy content in each of the individual pressure discharges.
It is clear from the tests that the cleaning effect for a selected nozzle is increased with increasing air pressure.
Further, it appears from the test that the size of the nozzle must be proportional to the volume of air.
It also appears from the test that if an air flow restriction, such as a nozzle, is not used, there is no cleaning effect.
The test in which no nozzle was used was carried out while the blast gun was working. If the blast gun is stopped and the nozzle removed, it is not possible to start the blast gun. That is probably one of the reasons why an adjusting valve 22 - 24 has to be installed in the prior art (Odendahl) blast gun.
Compared with the prior art blast gun, the blast gun according to the instant invention is simpler in its construction and is easier to operate.
The improved benefits are notably:
1. High cleaning effect.
2. High efficiency.
3. It is sturdy and dependable and easy to operate.
4. It is simple in construction and therefore inexpensive to manufacture.
5. Extension barrels of a length of 250 cm or more may be used without the cleaning effect being substantially reduced.
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A dusting gun for removal of dirt and for cleaning purposes, where dirt, dust, oil and other loose or firmly sticking coats are removed with compressed air. The dusting gun comprises an oscillating pressure discharge valve which causes splitting up of the air flow into periodically repeated pressure discharges. The oscillating valve acts automatically under the influence of the static and dynamic pressures of the compressed air and is designed to oscillate with a frequency in the range of 2-50 Hz. The oscillating valve is connected to a nozzle by an elongated air duct.
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BACKGROUND OF THE INVENTION
This invention was made with Government support under Contract No. N68786-89-D-1661 awarded by the Department of the Navy. The Government has certain rights in this invention.
This invention pertains generally to the field of laser-based optical communication systems, and, more particularly, to a method for enhancing the transmission and reception of optical pulses, while protecting the security of the information conveyed by said pulses.
In laser communications systems, laser power is often at a premium. To best take advantage of the maximum laser power to be available in each pulse, a pulsed modulation technique is normally utilized. Because of other factors involved (i.e., the frequency with which these pulses can be generated, thermal considerations, etc.), the pulse modulation normally chosen is Pulse Position Modulation (PPM). The basis of PPM is that the information symbol to be transmitted determines the position of a transmitted pulse within some well defined, fixed time window. This time window is commonly referred to as a "frame." Often times, even though the total power available from the laser is expended in each pulse, the received energy may not be much greater than the background noise of the communications channel. In point of fact, the received signal may be at a level lower than the incoming noise. This generally yields a signal-to-noise ratio (SNR) below a level required to accurately demodulate the received pulses into their original information symbols. In fact, for security reasons, it is desirable in many cases that the received pulse energy be artificially reduced (by lowering transmitter power if required) to such a low SNR that any third party attempting to eavesdrop on a communications session will find it difficult to detect the very fact that communications are occurring at all.
Prior solutions to the problem of detecting and demodulating optical pulses in an environment with a low SNR either have required an excessive amount of hardware or have lacked effective security for the information transmitted.
SUMMARY OF THE INVENTION
A principal object of the present invention is to provide an efficient, secure method for the transmission of optical pulses.
A further object of the invention is to provide a method by which a number of individual pulses may be summed together at the receiving end of a communication link in such a way as to improve the effective SNR of the resultant summed pulse to an amount sufficient for accurate demodulation.
Still a further object of the invention is to provide a method for generating a number of pulses based upon a single information symbol for the purposes of appropriately modulating a laser.
In a first aspect of the invention, a system for secure communication between transmitting and receiving devices in a laser communications system using pulse position modulation, comprises a transmitter means to modulate and a receiver means to demodulate a transmission utilizing a protocol in which a number N (where N≧1) of optical pulses represents each symbol to be transmitted. A transmission is initiated with a trigger event. Thereafter, a multi-pulse synchronization signal is transmitted as the first symbol of each transmission, the first pulse of said synchronization symbol being transmitted within a first time frame after said trigger. A buffer in said receiver receives and stores the first of said N frames of said synchronization symbol. Each subsequently received frame of said N frames of said synchronization symbol is added to data previously stored in said buffer. A frame template is calculated from the stored pulse data of said first N pulses in said buffer and from said synchronization symbol protocol. The calculated frame template is used for reception of subsequent message symbols, which will have been transmitted in N frames per symbol.
In a second aspect of the invention, the system includes an algorithm for the synchronization symbol format which pseudo-randomly positions each of said N-1 pulses after said first pulse within its frame by offsetting the start time of its pulse by a predetermined amount of time, with reference to the start time of said first frame.
In a third aspect of the invention, the system also includes an algorithm for the message symbol format which pseudo-randomly positions each of said N-1 pulses after said first pulse within its frame by offsetting its pulse position from that of said first frame such that the separations of said pulses vary from frame to frame within a symbol, and said algorithmically determined position of any pulse falls within the live time of its frame.
In a fourth aspect of the invention, a method for secure communication of data between transmitting and receiving devices in a laser communication system using pulse position modulation, comprises the steps of: selecting a number N (where N≧1) of pulses to represent each symbol to be transmitted; selecting a pulse position format for each pulse of said N pulses of a synchronization symbol, such that each of said N pulses appears to be pseudo-randomly positioned within its frame; selecting a pulse position format for each pulse of said N pulses of each message symbol, such that each of said N pulses is pseudo-randomly positioned within its frame; selecting a trigger event to signal the start of a transmission; wherein said number of pulses, symbol formats, and trigger event being known by both transmitter and receiver; initializing a transmission with a trigger signal; transmitting a synchronization symbol having N pulses, in N sequential frames, one pulse per frame, to a receiving device immediately after a trigger event; receiving and storing the first frame of pulse data of said synchronization symbol in a buffer of said receiving device; and adding each subsequently received frame of pulse data of said synchronization symbol to pulse data previously stored in said buffer, such that the sum of said N frames is said synchronization pulse; calculating a frame template, from the stored pulse data of said first N pulses in said buffer and from said selected synchronization symbol format, for subsequent message symbols; and transmitting each subsequent message symbol in N frames per symbol, in said calculated frame template, the first of said frames of each message symbol being stored in said buffer, and subsequent frames being added to said stored data, such that the summed data in said buffer after receipt of said Nth frame of each message symbol represents the message symbol.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an illustration of a single optical pulse time frame, as used in the preferred embodiment of this invention;
FIG. 2 is a diagrammatic representation of the format of a multiple-pulse synchronization symbol, illustrating the positions of its optical pulses within time frames as transmitted and their correlation for summing, according to the method of the present invention;
FIG. 3 is a diagrammatic representation of the format of a multiple-pulse message symbol, illustrating the positions of its optical pulses within time frames as transmitted and their correlation for summing, according to the method of the present invention; and
FIGS. 4 and 5 are exploded timing diagrams for two additional message symbols, according to the format of FIG. 3.
DESCRIPTION OF THE PREFERRED EMBODIMENT
This invention pertains to an optical communications system using Pulse Position Modulation (PPM) in which a number N of individual optical pulses are used to represent each transmitted symbol. Unlike the standard one pulse per symbol format, as is normally the case in PPM, the method of this invention requires N pulses to represent a symbol. The N received optical pulses in a symbol must be summed together in some manner to improve the effective SNR of the resultant summed pulse at the receiver to a level sufficient for accurate demodulation, that is, to a value sufficient to achieve decoding with a reasonable error rate. For this purpose, it is necessary to provide a method for generating a number of optical pulses based upon a single information symbol for the purposes of appropriately modulating a laser. For all examples in this specification, N is assumed to be 4. As will be discussed later, the value for N may, in fact, be virtually any number desired.
FIG. 1 illustrates a single time frame 10, comprising a period of dead time 12, during which no optical pulse is transmitted, and a period of live time 14, during which an optical pulse may be transmitted. The live time 14 of each frame is further subdivided into a number of bins 16, each bin 16 comprising a number of clock cycles, and capable of containing a single optical pulse. Typically, only one pulse per frame is transmitted in Pulse Position Modulation, its significance being determined by the relative position of the bin in the frame in which it is transmitted. By definition, that pulse is transmitted in the middle of the bin 16. Since the method of this invention uses N optical pulses to represent each symbol, a group of N frames is required for transmission of each symbol.
For purposes of communications security, it is further desired that the optical pulses appear to be randomly located within their respective frames. This is because an interested third party could perform a simple averaging operation over windows of fixed size and recover the transmitted information almost as easily as the two communicating parties. Thus, the relative locations of the pulses within a symbol frame group and from symbol to symbol must vary in a manner which appears to be random to any third party. The manner in which this pseudo-randomization is achieved is discussed below in connection with the Synchronization Symbol Format and the Message Symbol Format sections of this specification.
In any communications system, some means must be provided for establishing communication initially. There are two general classifications for initialization procedures, cooperative and noncooperative. It can be shown that a noncooperative scheme is likely to be very difficult to implement as compared to a cooperative scheme. In addition, there are several cooperative schemes that would appear to interested third parties to be noncooperative. Since it can be shown that this later point is true, then, given the relative complexities involved, the cooperative approach will result in a practical, realizable system. Hence, the method of the present uses such a cooperative initialization mode.
In the noncooperative mode of operation, the demodulator must "see" the pulse stream without any a prior knowledge as to the time at which said stream began emanating from the modulator. To achieve this means: that the data stream must be self synchronizing and that the demodulator must be capable of detecting any of a number of possible character patterns (i.e., must search for a number of patterns simultaneously); or a synchronization symbol(s) must be periodically transmitted. If the first condition applies, the amount of hardware required quickly becomes prohibitive. Buffer memories on the order of a frame in length for each pattern to be searched plus the analysis hardware for each buffer, or hardware with sufficient speed to be used on multiple buffers, implies a large amount of power and board space. Another important drawback is the fact that if the patterns are in some sense self-synchronizing over the length of a message, then they are more easily detected by interested third parties.
If the technique of periodic transmission of synchronization pulses is used in a noncooperative (or cooperative) mode, then security is degraded by the extra time the transmitter is firing to transmit those extra synchronization symbol pulses. Also the message itself, or some recognizable portion thereof which could be the synchronization symbols, must be sent enough times (repetitively) to assure the link is established and that at least one complete message has been received. Additionally, the hardware requirements for this scheme are also sizable. In fact the amount of memory required can be an amount on the same order as the previous case. To be constantly looking for a specific pattern requires N buffers of a frame in size where N is approximately equal (though not necessarily equal) to the number of pulses in a symbol.
The amount of memory required in both of these cases for the noncooperative mode of initialization is proportional either to the number of patterns to be searched, which should be large to enhance security, or to the number of pulses per synchronization symbol, which could be large. The amount of hardware can be reduced to a relatively small, fixed amount, through the use of a cooperative link initiation scheme.
The cooperative mode of initialization works by timing both the transmit and receive ends of the uplink from a common reference point. If the demodulator knows within some small window of time when it will "see" the pulses of the first symbol and it knows what the pattern of the first symbol is, then it can start demodulating from the beginning of a message. This means that only one synchronization symbol need be sent for each individual message. Also, each message need only be sent once in the minimum case. The method of this invention utilizes such a common reference point, or trigger pulse, as will be explained with reference to FIG. 2.
Several events can be used as the triggering mechanism:
1) The normally receiving end of the communications link could transmit a pulse, or group of pulses, a trigger, to the normally transmitting end of the link. The round trip delay (which is the sum of the total photon travel time plus trigger processing time plus responding laser firing time) is generally calculable. The total time is not important. What matters is the time uncertainty. If this uncertainty is less than one-half (1/2) of the uplink frame dead time, the demodulator can uniquely decode the synchronization symbol pulse sequence.
2) If real Time Of Day (TOD) clocks are available to both the modulator and demodulator, and if the absolute time differential between these two clocks is within one-half (1/2) of the uplink frame dead time, then transmissions can occur on a scheduled basis.
3) If some third party (other than an eavesdropper) transmits a trigger signal to both the modulator and demodulator, then transmission can begin anytime following the trigger event up to the point at which the reference oscillators within the two communicating units drift too far apart in terms of clock cycle slips.
4) The modulator could first transmit a pulse or several pulses with sufficient SNR to allow the demodulator to achieve synchronization. This technique greatly degrades the security goal and is mentioned only for completeness.
Whichever technique is used, the demodulator is required to sum a single fixed pattern of pulses, as will be explained later in reference to FIG. 2. This, in turn, requires a single buffer memory whose size is determined solely by the incoming sample rate and the maximum frame length with which the system must operate. The amount of memory is not affected by the number of pulses in a symbol. Thus, assuming the following:
A) 15 MHz sampling rate, and:
B) 8 bit samples, and:
C) 100 mS maximum frame time, yields: 15e6*0.1=1.5 Mbytes of memory. This is 1% of the memory required by a comparable noncooperative system.
FIG. 2 is an exploded diagrammatic representation of the timing format of a multiple-pulse synchronization symbol, illustrating the positions of its N optical pulses within a group of N time frames as transmitted and the correlation of these N optical pulses for summing, according to the method of the present invention. Since N=4 in this example, FIG. 2 illustrates a group 20 of four frames 22a, 22b, 22c, and 22d, each of said frames containing a single pulse, the four pulses, shown as up-arrows 23a, 23b, 23c and 23d, representing one synchronization symbol. In the preferred embodiment of this invention, the synchronization symbol format, that is, the locations of each of said pulses within their respective frames, is known to both ends of the uplink. This synchronization symbol pattern (format) may change based upon some prearranged algorithm at some time interval. However, at any given time, the specific pattern used must be known to both ends of the communications link.
FIG. 2 also illustrates the synchronization acquisition technique for the multiple pulse/symbol modulation format, according to the preferred embodiment of the invention. The initiating event can be a trigger pulse 24, or an equivalent such as time of day (TOD), as discussed above, trigger pulse 24 being time-aligned as closely as possible to the center 26 of the dead time 21 of the first frame 22a of group 20 (with possibly a known, fixed offset). Trigger pulse 24 opens an aperture 27 during which the receiver looks for consecutive frames of pulse data. A fixed time after the trigger event 24, the demodulator begins storing data in its correlation buffer 25. Thus, the start of this storage process will also be time aligned as closely as possible to the center 26 of the dead time of the first frame, which is the beginning of aperture 27. This initial storage will continue for one full frame, 22a. At the end of this time, data for the second frame 22b is beginning to be received. However, since the synchronization symbol format is known by the receiving end of the link, the receiver also knows that pulse 23b, which will appear in the second frame 22b, has been shifted by a known offset from the position of pulse 23a already received in the first frame 22a. In the illustration of FIG. 2, the sequence of offsets used for the second, third and fourth frames is -4, +1, and -3 respectively, calculated from the opening of aperture 27 at the center of dead time 26 of frame 22a. Therefore, the data (pulse 23b) in the second frame 22b is added to the stored data (pulse 23a) in the correlation buffer 25 from the first frame 22a, with a time shift equal to the relative time shift of the two pulses. Subsequent frames are added to this sum in like manner, until N frames have been received and added. In the exploded timing diagram of FIG. 2, frames 22a-22d are shown in alignment with the first frame of aperture 27 and correlation buffer 25, the alignment of frames 22b-22d being adjusted for the offsets from frame 22a. This diagrammatic representation shows that pulses 23a-23d are then aligned for summing. The resultant summed pulse 28 in correlation buffer 25 is the synchronization symbol.
At the end of the last synchronization frame, the summing buffer 25 should contain what amounts to a reconstructed version of a frame that might have been transmitted if the link were operating in a single pulse/symbol mode. However, this frame is bounded not by the transmitted frame boundaries, but by the boundaries of the local buffer 25. The composite pulse 28 that resulted from the summing operation was known to represent a real pulse whose absolute position in a real frame is known to the demodulator. A calculated frame template 29, which is a reconstructed version of the first frame of the originally transmitted group 20 of frames, can now be developed. Further, since by definition the transmitter always transmits a pulse in the center of a bin, this calculated frame template 29 is accurate to within the ability of the demodulator to determine the center of the pulse.
If the number of pulses per symbol is large enough, or the sampling rate is sufficiently low, software would be able to determine this position, i.e. the center of the pulse, to within a few clock cycles. If, on the other hand, such is not the case, data reduction via peak detection and Time of Arrival (TOA) of the detected peaks can be used to reduce the effective data rate. If the latter is the case, then the accuracy of determining pulse position is reduced to some fraction of the pulse width.
As the distance from the boundaries of the reconstructed frame 29 to the summed pulse 28 can be determined, and the distance from the summed pulse 28 to the boundary of summing buffer memory 25 can be determined, the offset of aperture 27 can be calculated. This offset is calculated to the same degree of accuracy as the center of the bin containing the summed pulses was previously calculated. This capability is important, because it determines the setting of the message pulse search aperture described in the following paragraphs.
It is important to note that the synchronization pulse decoding may be done in a maximum likelihood manner, rather than with threshold decoding.
FIG. 3 is an exploded diagrammatic representation of the timing format of a multiple-pulse message symbol, illustrating the positions of its N optical pulses within a group of N time frames as transmitted and the correlation of these N optical pulses for summing, according to the method of the present invention. Since N=4 in this example, FIG. 3 illustrates a group 30 of four frames 32a, 32b, 32c, and 32d, each of said frames containing a single pulse, the four pulses, shown as up-arrows 33a, 33b, 33c and 33d, representing one message symbol. The message symbol format of FIG. 3 at first glance appears to be identical with the synchronization symbol format of FIG. 2. However, unlike the fixed pulse locations in the synchronization symbol format, the message symbol is defined by the following set of rules:
1) The separations between pulses in a symbol are known to both ends of the communications link.
2) These separations vary from pulse to pulse within a symbol.
3) The separations are algorithmically determined by an algorithm available to both ends of the communications link. This sequence is referred to as the symbol pattern.
4) The symbol patterns vary from symbol to symbol.
5) The sequencing of the symbol patterns is algorithmically determined.
6) The sequencing algorithm is known to both ends of the communications link.
7) The location of the first pulse of a symbol within its frame determines the value of that symbol.
8) If, due to the location of the first pulse of a symbol, any subsequent pulse within that same symbol should be determined to need to be generated in the dead time of a frame of yet a third pulse, the out of bounds pulse will be generated in its own associated frame's live time in a location determined by the following formula:
New location=(Location of first pulse+Pulse separation value) modulo live time size in bins.
Following the rules given above, and by choosing a suitable algorithm for pulse pattern generation, an apparently random pulse pattern containing a decodable structure will result.
The exploded timing diagram of FIG. 3 also illustrates the process of message pulse decoding. Though similar to synchronization pulse decoding, there is one major difference. The pulse search aperture 37 is open only for the live time 31 of each frame 32a-32d. This is required because, given the rules previously listed, the absolute offsets of message symbol pattern generation between pulses 33a-33d are not always known. What is known is their offset modulo the live time in numbers of bins. Thus, in contrast to synchronization pulse summing, message pulse summing proceeds using wrap around of the incoming data into the summing buffer 35. The dotted line sections of frame live times 31 shown in FIG. 3 represent this modulo operation.
Without discussing the mathematical considerations involved, the pulses 33a-33d again align in the summing buffer 35, thus enabling the reconstruction of a summed pulse 38 representing the specific character sent. Since the pulse position within the summing buffer 35 can be determined, and the boundaries of buffer 35 align with the live times 31 of the frames 32a-32d, the absolute position of the summed pulse 38 in the reconstructed, i.e. calculated, frame template 39 can be determined, thus yielding the transmitted symbol.
Referring back to FIG. 1, therein each of the eight bins 16 represents one of the letters A through H. Thus, the message symbol in FIG. 3 is B. FIGS. 4 and 5 present the timing diagrams for two additional message symbols A and H.
A few other points are derived from this decoding scheme. First, this demodulation method involves maximum likelihood with a possible addition. If the number of pulses per symbol is large enough, sufficient processing can take place to compare the relative quality of several of the largest pulses in the reconstructed frame. As an example, suppose there appear two pulses of close to equal magnitude in a frame. In normal maximum liklihood decoding, the largest pulse would be declared the correct one and that would be that. However, if the largest pulse were not bin centered (possibly even straddling two bins), and the second largest pulse was bin centered, then there is some probability that the bin centered pulse is in fact the correct one. This probability is dependent upon the offset of the questionable pulse from the center of its best fit bin.
A second ramification of this decoding process is that link synchronization can be maintained without the periodic use of a synchronization signal. The first synchronization symbol is required to yield an initial point of reference. However because, by definition, the transmitter always places pulses in the center of their bins, then the decoder can use this information to adjust the message pulse search apertures depending upon the apparent offset of the reconstructed pulse from a bin center. If the setability of the two modulator/demodulator master clocks is sufficiently fine, then the drift between them can be kept to a low enough level across a symbol that the aperture-to-aperture starting adjustments need not be very great,
For example, given:
A) Frame size=100 mS
B) Pulses per symbol=100
C) Clock frequency=15 MHz
The drift of one clock cycle=1/15e6=67 nS. The symbol time=0.1*100=10 seconds. Thus, the setability required to maintain drift between the two clocks must be at least=67e-9(10*2)=3.3e-9. This is a value available in a number of ovenized crystal oscillators.
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A system for secure communication between transmitting and receiving devices in a laser communications system using pulse position modulation, has a transmitter means to modulate and a receiver means to demodulate a transmission utilizing a protocol in which a number N (N≧1) of optical pulses represents each symbol to be transmitted. A transmission is initiated with a trigger event. Thereafter, a multi-pulse synchronization signal is transmitted as the first symbol of each transmission, the first pulse of said synchronization symbol being transmitted within a first time frame after said trigger. A buffer in said receiver receives and stores the first of said N frames of said synchronization symbol. Each subsequently received frame of said N frames of said synchronization symbol is added to data previously stored in said buffer. A frame template is calculated from the stored pulse data of said first N pulses in said buffer and from said synchronization symbol protocol. The calculated frame template is used for transmission of subsequent message symbols, which are then transmitted in N frames per symbol. The system includes an algorithm for the synchronization symbol format which pseudo-randomly positions each of said N-1 pulses after said first pulse within its frame by offsetting the start time of its frame by a predetermined amount of time, with reference to the start time of said first frame. The system also includes an algorithm for the message symbol format which pseudo-randomly positions each of said N-1 pulses after said first pulse within its frame by offsetting its pulse position from that of said first frame such that the separations of said pulses vary from frame to frame within a symbol, and said algorithmically determined position of any pulse falls within the live time of its frame.
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BACKGROUND OF THE DISCLOSURE
The present invention relates to acoustical control media which can be formed in panels or the like for use in noise reduction.
There exists a great variety of acoustical material used, in for example, sound absorbing panels forming room dividers in offices, ceiling tile, and the like. The existant structure typically relies on either the sound absorptive properties of a very low density typically fiberglass material useful in absorbing higher frequency components of undesired noise. Frequently, in connection with such fill materials, solid barriers also are employed for blocking high and low frequency energy. High density perforated surface material has been employed also and in some cases in combination with cellular chambers to provide resonant cavities at the audible spectrum for absorbing lower frequency components of acoustical energy. Representative of such prior art are U.S. Pat. Nos. 3,132,714; 3,166,149; 3,211,253; 3,384,199; 3,448,823; 3,502,171; 3,712,846; 3,949,827; 4,155,211. A discussion of the mathematical principles associated with perforated panels is provided in an article entitled "Sound Absorption by Structures with Perforated Panels" by Jacques Brillouin, published in Sound and Vibration in July 1968.
Although the prior art structures provide noise reduction at either the upper or lower end of the frequency spectrum and some efforts have been made to broaden the bandwidth of the sound absorptive or controlling properties of acoustical panels employing for example a combination of techniques, existant structure has not provided the degree of noise isolation desirable in modern offices in which room dividing acoustical panels are employed to divide an office space into individual work areas. In this environment, a relatively small decible change in noise reduction provides a significant increase in privacy for the work areas. Typically to improve low frequency attenuation the thickness of a given sound absorptive panel is increased. It is desirable however to provide as thin an acoustical panel as possible to conserve space as well as provide an aesthetically pleasing appearance.
SUMMARY OF THE PRESENT INVENTION
The acoustical control media of the present invention provides improved broad band reduction of noise by providing an air impervious septum and a perforated panel of medium density material spaced therefrom. In the preferred embodiment the medium density panel is perforated with spaced apertures having a perforation ratio in the neighborhood of about 0.04. In one embodiment of the invention the space between the septum and the medium density material is filled with a low density material. According to another aspect of the invention a panel of medium density material is provided and is bonded to a relatively thin acoustically transparent mat to improve tackability to the panel.
In applications such as acoustical panels employed in offices, a septum is provided and is spanned on opposite sides by the low density material and a perforated panel which can, if desired, be covered by a decorative fabric which is acoustically transparent.
These and other features, advantages and objects of the present invention will become apparent to those skilled in the art upon reading the following description thereof together with reference to the drawings in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a fragmentary perspective view of one embodiment of the present invention;
FIG. 2 is a cross-sectional view of the structure shown in FIG. 1 taken along the section lines II--II of FIG. 1;
FIG. 3 is an enlarged view of the portion of FIG. 2 circled and identified by the reference III;
FIG. 4 is a fragmentary perspective view of an alternative embodiment of the present invention;
FIG. 5 is a cross-sectional view of the structure shown in FIG. 4 taken along the section lines V--V of FIG. 4;
FIG. 6 is a perspective view of an acoustical panel embodying the present invention; and
FIG. 7 is a fragmentary cross-sectional view of a portion of the structure shown in FIG. 6 taken along section lines VII--VII of FIG. 6.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring initially to FIG. 1 there is shown a section of the acoustical control media of the present invention which includes a septum 10 made of an air impervious material such as wood, steel, chipboard or fibreboard or other relatively high density air impervious material which in the preferred embodiment was about 0.060 inches thick although other thicknesses could be used. Positioned in abutting relationship to septum 10 is a relatively thick layer of low density sound absorptive material 12 comprising for example, in the preferred embodiment, fiberglass bat material having a thickness of 7/8 of an inch and having a density in the range of about 0.5 to 3 pounds per cubic feet. On the outer surface which faces the source of sound energy to be absorbed or reduced, is a relatively thin layer 14 of a medium density sound absorptive material which in the preferred embodiment is perforated. Layer 14 may comprise a sound absorptive fiberous board 15 that ranges in density from 6-14 pounds per cubic foot. Bonded to the outer surface of material 15 is an acoustically transparent fiberglass mat 17 such as a speciality mat No. 7112 commercially available from Johns-Manville Products Corporation. The material 15 in the preferred embodiment had a thickness of approximately 1/4 of an inch and was made of commercially available fiberglass board. Uniformally spaced and extending through layer 14 including material 15 and mat 17 is a plurality of apertures 16 which in the preferred embodiment comprises round holes formed through the layer at equal spacing intervals. The apertures 16 have a size and spacing such that the perforation ratio defined by the hole area divided by the total panel area is about 0.04. Examples of perforations to provide this perforation ratio is 1/8 inch holes equally spaced at 1/2 inch centers, 3/16 inch holes spaced at 3/4 inch centers, and 1/4 inch holes spaced at 1 inch centers, which provide perforation ratios of 0.045, 0.043, and 0.041 respectively. Mat 14 of the preferred embodiment has a density which provides tackability such that, if desired, objects can be secured to an acoustical panel formed of this construction. The outer mat 17, although increasing the structural rigidity and tackability of the layer 14 does not interfere with the transmission of acoustical energy to the medium density material.
The acoustical control media of the preferred embodiment of the invention substantially uniformly reduces noise in the range of 200 H z to about 5 KH z and tests in the range between 400 H z and 2 KH z indicate that the noise reduction at a 12 foot test position is in the neighborhood of at least 21 NIC F ' measured according to the Public Building Service Test Method PBSC.2, (May 1975 revision) procedure III-S category B; primary flanking configuration. This construction has been found to also increase the attenuation of voice frequency energy in the range of about 500 to 1600 H z to improve office privacy when used in acoustical panels dividing an area into office spaces.
FIGS. 4 and 5 show an alternative embodiment of the present invention in which a decorative fabric cover layer 20 is applied to the outer surface of the acoustical control media. The decorative cloth 20 is acoustically transparent and substantially air pervious (i.e. has at least 30% open space). As shown in FIGS. 6 and 7, the acoustical control media can be employed in an acoustical panel 30 of the type employed for the separation of office space into individual work areas. Panel 30 includes a frame 32 extending around the periphery thereof and in the preferred embodiment includes a base 34 through which electrical conductors provide electrical service for the offices defined by these separating panels. The construction of the panel frame can generally be of the type disclosed in U.S. Pat. No. 4,203,639 issued May 20, 1980 and assigned to the present assignee. The acoustical media of the present invention can as seen in FIG. 7 be provided on opposite sides of the septum 10 to provide sound isolation between opposite sides of such a panel. Naturally, the acoustical control media of the present invention can take forms other than panels shown in FIG. 6 and for example can be fabricated as wall hangings, walls, ceilings, or other shapes and sizes used for reducing acoustical energy transmission or reflection. The thickness of perforated material 14 can be varied so long as the density of the material falls within the desired range as does the perforation ratio. The middle layer 12 of low density material could in some instances be left as a void and the depth or density of the filler material or the depth of the void can be varied within reasonable ranges.
According to one aspect of the present invention an acoustical panel is provided of medium density material with or without perforations to which there is bonded a relatively thin fibrous mat. This construction is shown in FIG. 3 comprising a backing material 15 preferably of a fibrous nature and having a density of from about 6 to 14 pounds per cubic foot. Its thickness can be selected for a desired application. This material is manufactured commercially by compressing under heat a significantly thicker and less dense material to provide the desired medium density backing material. Mat 17 is of the same commercially available type described above and has a thickness of about 0.030 inches and is essentially transparent. It has been discovered that the two materials can be bonded together by pressing layer 15 together with mat 17 at a temperature of about 350° F. The resin binder typically in or added to the backing material is sufficient to provide a secure bond between the mat and the medium density backing material. The combination provides a tackable (i.e. structural member to which items can be fastened) and acoustically absorptive material which can be used in combination with the septum and/or low density filler material as in the preferred embodiment of the invention or by itself for less critical acoustically related applications.
It will become apparent to those skilled in the art that these and other modifications to be preferred embodiments of the invention as described herein can be made without departing from the spirit or scope of the invention as defined by the appended claims.
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An acoustical control media includes an air impervious septum adjacent which there is positioned a relatively thick layer of low density filler material on the outside of which there is provided a relatively thin panel of medium density perforated material. The acoustical media so formed can be used in acoustical panels employed to separate work areas in an office and in such applications decorative coverings can be provided over the perforated layer. The structure so formed provides improved broad bandwidth absorption of acoustical energy.
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RELATED APPLICATIONS
This application is a national phase application filed under 35 USC §371 of PCT Application No. PCT/GB2010/052188 with an International filing date of Dec. 22, 2010 which claims priority of EP Patent Application 09275132.0 filed Dec. 23, 2009 and GB Patent Application 0922443.7 filed Dec. 23, 2009. Each of these applications is herein incorporated by reference in their entirety for all purposes.
FIELD OF THE INVENTION
This invention relates to air vehicle mounted transmitting and/or receiving equipment which includes transmitting and/or receiving devices used for observation, surveillance, reconnaissance, targeting, monitoring, inspection, measurement or like purposes, and associated fairings for use with such devices, herein collectively referred to as transmitting and/or receiving equipment.
BACKGROUND OF THE INVENTION
Where devices used for observation etc are employed on an aircraft, then it is desirable to have a good field of view. For observation cameras, this good field of view has been achieved by mounting the camera on an enclosed gimbal or turret on the underside of the aircraft, so that the camera is protruding from the underside of the aircraft and can swivel about one or more axes. This mounting provides a good field of view in all directions—forwardly in the usual direction of travel of the aircraft, rearwardly in a direction facing away from the usual direction of travel, and at intermediate positions. Such cameras are already available for helicopter use, for example under the name Wescam MX-20 and so development costs are saved if these “off-the-shelf” devices can be employed.
One drawback of having a protruding camera is that it increases aerodynamic drag significantly when the aircraft is travelling at speed. This is not too problematic for relatively slow moving aircraft such as helicopters or lighter than air aircraft, but where increased air speed is required then the drag becomes a significant problem. It is not practical to retract the camera into the aircraft fuselage if it is in use.
Unmanned air vehicles (UAVs), are generally used for observation. So, cameras fitted to such air vehicles are in use for the majority of their flight, and so retracting the camera is not practicable, and in any event generally precluded for reasons of space and weight. Thus the camera needs to be exposed for use, in a drag-inducing position. Similar considerations apply to equipment designed to transmit a beam of radiation as well as or instead of receiving, and the term “field of view” should be interpreted correspondingly.
SUMMARY OF THE INVENTION
In a first aspect the present invention provides transmitting and/or receiving equipment mounted or mountable to a fuselage of an air vehicle, the fuselage including, when viewed fore to aft, an underside having a generally linear initial portion, a further generally linear aft portion which is lower than the initial portion, and an intermediate portion between the initial and aft portions, the equipment is mounted or mountable to the intermediate portion such that the initial portion is forward of the equipment, and the aft portion is aft of the equipment, the equipment comprises: a device for transmitting and/or receiving allowing at least a forward field of view for the transmitting and/or receiving, said device being mounted or mountable at the intermediate portion such that it extends away from the fuselage; and a fairing mounted or mountable to the fuselage at the intermediate portion adjacent said device at a rearward side of the device for reducing aerodynamic drag, said fairing being retractable, collapsible or repositionable to afford the device a rearward, or more effective rearward, field of view for said transmitting and/or receiving.
In an embodiment, the fairing is of a generally tapering shape having a taller end adjacent or proximal the device and a thinner or shorter end away or distal from the device. Thereby, the fairing acts to reduce drag caused by the device alone, by reducing turbulent flow at the rear of the device.
In an embodiment, the fairing is retractable, at least partially into the fuselage.
Preferably, the fairing is retractable by means of pivoting at a hinge at its thinner end.
Preferably, the device has a horizontal width and the fairing, at least at its proximal end is approximately the same width as the device.
Preferably, the device has a cylindrical region including an axis which extends generally downwardly in use, and the fairing, at its proximal end, has, in horizontal section, a concave region for accepting part of the cylindrical region.
Additionally, the fairing's proximal end may be formed with a radius having a centre of arc approximately at the hinge.
Conveniently, the fairing includes an outer wall and is hollow and may include a stiffening frame, preferably formed from members extending generally transversely to the wall.
Where the fairing is retractable, it may include a retraction mechanism. Said mechanism may include an electric drive and bar arrangement. Such an arrangement may include two bars pivotally interconnected at adjacent ends, a first of the bars being driveable in rotation by rotation of the electric drive, and a second of the bars being further pivotally connected to the fairing. Where such a mechanism is employed, the rotation of the drive will cause the first of the bars to rotate about the rotational axis of the drive, and will thus cause the second bar to move with the first bar and thus pivot the fairing about the hinge.
The mechanism may include a gearbox.
In an embodiment, the two bar arrangement includes an overcentering spring which resists movement of the mechanism at least when the bars are positioned in a fairing-retracted position.
The invention extends to an air vehicle including equipment according to the invention as defined above, mounted to a fuselage of the vehicle.
In an embodiment, said fuselage includes an underside having a generally linear initial portion, when viewed fore to aft, forward of said equipment, a further generally linear aft portion, aft of said equipment which is lower than the initial portion, and an intermediate portion between the initial and aft portions, said equipment being mounted at said intermediate portion.
Preferably, said intermediate portion is smoothly curved and the fairing is retractable into the intermediate portion, and when so retracted has approximately the same outer profile as the intermediate portion.
The invention extends to any novel feature defined herein, or any novel combination of features defined herein.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention can be put into effect in numerous ways, one embodiment only being described below, with reference to the drawings wherein:
FIG. 1 shows an embodiment of air vehicle equipment including a fairing deployed in a drag-reducing capacity;
FIG. 2 shows the equipment shown in FIG. 1 , wherein the fairing is in a semi-retracted position;
FIG. 3 shows the equipment shown in FIG. 1 , wherein the fairing is fully retracted;
FIGS. 4 , 5 and 6 show side views of the equipment illustrated in the previous figures, fitted to a UAV, in different positions.
DETAILED DESCRIPTION
Referring to FIG. 1 , a portion 5 of an air vehicle fuselage is schematically illustrated. Transmitting and/or receiving equipment 1 is illustrated also and is described in more detail below. The portion 5 has an under surface 6 to which is attached a transmitting and/or receiving device, in this instance an observation device, in the form of an electro-optical turret. The turret 7 , in this embodiment, includes a gimbal-mounted observation camera 9 , capable of being manipulated for rotation about a vertical rotation axis z and also a horizontal axis x. This manipulation allows the camera within the turret to have a field of view in any direction. Of most concern is a view in the direction of arrow F which is the intended forward direction of travel of the air vehicle to which the turret 7 is fitted.
In order to reduce aerodynamic drag created by the turret 7 when the air vehicle is travelling in the direction of arrow F, a fairing 10 is mounted to the fuselage 5 in a position which would otherwise be occupied by turbulent air from the turret 7 as the air vehicle travels in the direction of arrow F. However, the fairing 10 when so fitted, obscures, or partially obscures, the view of the camera in the turret 7 when the camera is manipulated to view in the general direction of arrow R, i.e. a rearward view. In order to mitigate this problem, the fairing 10 can be retractable, collapsible, or re-positionable, so that the rearward view is not obscured permanently. In this case, the fairing 10 is retractable for storage within the fuselage 5 , at least while the camera is viewing rearwardly.
The fairing 10 has a generally tapering shape including a taller end 12 (taller in the direction parallel to the axis z) which is adjacent the turret 7 , and a thinner end 14 distal from the turret 7 . The fairing 10 is attached to the fuselage 5 by means of a piano hinge 16 at the thinner end 14 . In the position shown in FIG. 1 , the width perpendicular to the x axis of the taller end 12 is approximately equal to the width of the turret. This means that the fairing provides good reduction of drag. In order that the fairing can be positioned as close as possible to the turret 7 , the taller end 12 includes a concave region 18 such that the cylindrical form of the turret 7 is accepted into the concavity 18 . In addition, the taller end 12 is generally curved and has a centre of arc approximately at the pivot axis of the hinge 16 .
The fairing 10 is attached to a retraction mechanism shown generally at reference 20 . This mechanism includes an electric drive 22 having an integral gear box 24 , which drives a shaft 26 about arc y of approximately 180°. In the fairing-deployed position shown in FIG. 1 , a pair of first bars 28 are positioned such that they are generally co-linear with a pair of second respective bars 30 pivotally attached to the free ends of the first bars 28 . In this position the bars 28 and 30 force the fairing 10 generally away from the shaft 26 and into the said deployed position. Any free movement in the mechanism is resisted by springs 32 attached, at their one end to the bars 30 and at their other end to the fairing 10 . In this position, the bars 28 and 30 gives a line of force which exerts little or no torque on the shaft 26 because the connecting points of first and second bars are in general alignment with the axis of the shaft 26 and the attachment points at the fairing 10 . The alignment is such that the bars have a slight overcentre action and are held in place by springs 32 . The gearbox 24 may, in addition, have sufficient internal friction to resist or prevent unpowered rotation of the shaft 26 , for example caused by air pressure acting on the fairing 10 .
In this view it can be seen that the fairing 10 has an outer wall 34 and a hollow interior. The outer wall 34 is stiffened by a stiffening frame 36 which extends generally perpendicular to the wall 34 .
FIG. 2 shows the fairing 10 in a semi-retracted position following the rotation of the shaft 26 in the direction of arrow Y for approximately 90°. In this position it will be noted that the bars 30 and 28 are now at a relative angle of approximately 90° also. The movement of the shaft 26 causes the fairing 10 to move in the direction of arrow A, about hinge 16 . In this figure, the concavity 18 is more clearly visible.
FIG. 3 shows the fairing 10 in its fully retracted position within the fuselage 5 .
It will be noted that the bars 28 and 30 are again generally co-linear following further rotation of the shaft 26 in the direction of arrow Y. In this position, the springs 32 illustrated in FIG. 1 urge the bars 30 toward the shaft 26 . Since the bars 30 are slightly cranked an overcentre mechanism is again provided in the retracted position and consequently the bars 28 and 30 are urged into their fairing-retracted positions illustrated by means of the springs 32 .
In FIG. 3 the curvature 8 of the fuselage 5 is apparent at a region where the fairing 10 is retracted. This curvature is explained in more detail below. FIG. 4 shows a UAV front section 2 , incorporating the fuselage 5 , to which has been fitted the transmitting and/or receiving equipment 1 . The exposed turret 7 is visible which has a field of view both forwards F and rearwards R. The drag reducing fairing 10 is illustrated in its deployed and operative position, behind the turret 7 .
FIG. 5 shows the same view as that shown in FIG. 4 except that the fairing is partially retracted into the fuselage of the UAV 2 .
FIG. 6 shows the same view as that shown in FIG. 4 except that the fairing is now fully retracted.
In FIGS. 4 , 5 and 6 the contour of the underside 6 of the fuselage 5 is not linear where the equipment 1 is mounted. The fuselage is shaped with an initial generally linear portion 3 , in a direction fore to aft, and then curves downwardly immediately aft of the turret 7 mounting at curved intermediate portion 8 , at the point where the fairing 10 is located. The fuselage then straightens to another aft linear portion 4 , aft of the equipment 1 . The initial and aft portions are generally parallel. Thus a slopped or stepped fuselage is provided, which slopes smoothly downwardly immediately aft of the turret 7 . The reason for this sloped or stepped arrangement is to draw the fuselage down aft of the fairing 10 in order to reduce flow separation at the fairing 10 . The offset or stepped distance X is less than the height Y of the turret 7 , but greater than ½ Y. This gives an adequate field of view for the camera of the turret 7 , or for other transmitting and/or receiving device, but still reduces flow separation. The lower surface 11 ( FIG. 6 ) of the fairing 10 follows approximately the curved portion 8 when the fairing 10 is retracted.
A linear or generally straight underside has been found to produce turbulence at higher airspeeds, downstream of the turret 7 , and a fairing fitted to such a straight underside, would need to be approximately twice as long as the fairing 10 illustrated in order for that long fairing to have a similar affect on flow, if the underside were not sloped or stepped as shown.
Although one embodiment only of the invention has been described and illustrated, it will be readily apparent to the skilled addressee that many variants, modifications, additions or omissions are possible within the scope of the invention. For example, a generally cylindrical observation turret 7 has been illustrated which includes a hemispherical end. However, other transmitting and/or receiving devices could be used which have different shapes. For example, a spherical, elliptical or other rounded shape could be employed. Equally, a flat sided shape could be used. Equally a fairing having a different shape to that illustrated could be employed. Although the invention has been described in relation to turrets which include a camera 9 , it will be readily apparent that devices other than cameras could be employed, for example infra-red detection devices or other electro-magnetic radiation sensors could be employed. Accordingly the term “transmitting and/or receiving” should be broadly interpreted herein to include not only the transmitting and/or receiving of light, but also transmitting and/or receiving of non-visible electromagnetic spectra, the detection or emission of other media such as air pressure waves and the receiving of returning emitted signals, or the like. The associated expression “field of view” should thus be interpreted accordingly. The term “air vehicle” used herein should be interpreted widely to include any air-borne object. The turret 7 and fairing 10 in the embodiment illustrated do not touch in use, although a fairing which touches the turret or other transmitting and/or receiving device is possible within the ambit of the invention.
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Disclosed is an air vehicle mounted or mountable transmitting and/or receiving equipment including a transmitting and/or receiving turret allowing at least a forward field of view, the device being mounted or mountable on a fuselage such that it extends away from the fuselage to which it is mounted; and a fairing mounted to the fuselage adjacent the device at a rearward side of the device for reducing aerodynamic drag, the fairing being retractable by, for example, an electrically driven mechanism, to afford the device a rearward (arrow R), or more effective rearward, field of view for transmitting and/or receiving.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application claims priority to and the benefit of co-pending U.S. Provisional Application Set. No. 61/261,882, filed Nov. 17, 2009, the full disclosure of which is hereby incorporated by reference herein.
1. FIELD OF THE INVENTION
This invention relates in general to production of oil and gas wells, and in particular to an automated vent system that prevents overpressure within an annulus in a wellhead assembly.
2. DESCRIPTION OF RELATED ART
Systems for producing oil and gas from subsea wellbores typically include a wellhead assembly that includes a wellhead housing attached at a wellbore opening, where the wellbore extends through one or more hydrocarbon producing formations. Casing and a tubing hanger are landed within the housing for supporting casing and production tubing inserted into the wellbore. The wellhead assembly may include strings of concentrically arranged casing, such as conductor pipe, surface casing, and an inner casing. Generally, the inner casing goes deeper than the conductor pipe and surface casing and lines the wellbore to isolate the wellbore from the surrounding formation. Tubing typically lies concentric within the inner casing and provides a conduit for producing the hydrocarbons entrained within the formation. Annuli are defined between each pair of adjacent concentric tubulars, where each annulus is sealed from pressure communication with any of the other annuli. If an annulus becomes unexpectedly pressurized, such as from a leak or thermal expansion of fluids contained and constrained within the annuli, a pressure differential will develop across a tubular wall adjacent the pressurized annulus. Thus a need exists to periodically monitor the pressure in certain tubular members in well installations, both on land and at sea.
Checking the pressure in the inner wellhead housing would indicate whether or not any casing leakage or thermal loading has occurred. Subsea wells do not monitor pressure because installing a pressure sensor requires drilling a hole through the sidewall of the inner wellhead housing, which is operationally non-preferred from a pressure integrity standpoint. Further, because of the harsh and corrosive environments often encountered in petroleum well installations, an installed pressure sensor may succumb to the damaging effects and no longer perform.
SUMMARY OF THE INVENTION
Disclosed herein is a wellhead assembly that includes a pressure vent device that vents between concentric annuli when the pressure differential reaches or exceeds a pre-designated value. In an example embodiment the wellhead assembly includes an inner annulus set in a wellbore that is surrounded by an outer annulus. A tubular is between the inner and outer annuli that has a relief valve set in a sidewall. When closed, the relief valve forms a pressure seal between the inner annulus and outer annulus. The relief valve can selectively opened to allow venting from the higher pressure of the inner annulus and outer annulus. After the inner and outer annuli are substantially pressure equalized, the relief valve then closes. A designated pressure differential between the inner annulus and outer annulus can cause the relief valve to open. In an example embodiment, the relief valve includes a valve seat having a surface in pressure communication with one of the inner annulus or the outer annulus and that is biased to a closed position by a spring. The wellhead assembly may also include a passage leading through the wellhead from one of the annuli. Optionally, a pressure sensor can be set in one of the inner annulus or outer annulus. In an alternative embodiment, the inner annulus can be a tubing annulus and the outer annulus can be a casing annul us and the pressure relief valve allows flow from the casing annulus to the tubing annulus when in the open position. In an alternate example, the wellhead assembly includes a blocking sleeve selectively mounted within one of the annuli and into sealing contact with a vent side of the relief valve to block flow through the relief valve.
Also disclosed herein is a method of managing wellbore annulus pressure, in an example embodiment the method involves suspending a tubular in the wellbore that creates an inner annulus in the tubular and an outer annulus around the tubular. In the example method the tubular has a vent valve set in its sidewall, the vent valve opens in response to a pressure difference across the sidewall of the tubular. The pressure difference can be created when one of the inner annulus or outer annulus experiences an increase in pressure. The vent valve opens when the pressure difference is above a designated pressure differential. When open, pressure vents across the tubular to equalize the pressure in the inner and outer annuli. Thus when the pressure difference between the annuli falls below a set value, the vent valve closes. This example can also include monitoring pressure in the inner or outer annulus via non-intrusive means. The inner annulus can be a tubing annulus and the outer annulus can be a casing annulus. In an example embodiment, the annulus having a higher pressure is the outer annulus. In an alternative step, a bridging sleeve may be set in the tubular adjacent the vent valve to override the vent valve function. The wellhead assembly can include a vent passage for venting flow from the inner or outer annulus having the higher pressure through a wellhead and out of the wellbore.
An alternative embodiment of a wellhead assembly is described herein that is set over a well. Tubing is suspended in the well and circumscribed by a string of inner casing, that is surrounded by a string of outer casing. The tubing and inner and outer casings define an inner annulus between the tubing and inner casing and an outer annulus between the inner and outer strings casing. Also included is a pressure relief valve set in a passage in a side wall of the inner casing that blocks flow through the passage when a pressure difference between the inner annul us and outer annulus is less than a designated pressure differential and is selectively moveable out of the passage when a pressure difference between the inner annulus and outer annulus is greater than a designated pressure differential so that flow communicates through the passage from the outer annulus to the inner annulus. Optionally included with the wellhead assembly is a tubing annuls passage leads from the inner annuls and to an exterior of the wellhead assembly. Yet further optionally, a pressure sensor can be included in one of the inner annulus or outer annulus. Communication between the outer annulus and the exterior of the wellhead assembly may be limited to a flow path through the pressure relief valve. A blocking sleeve can be included that is selectively installable within the tubing annulus and into sealing contact with a side of the passage (during for instance a planned well workover).
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic partial cross sectional view of an embodiment of a wellhead assembly having an automated vent system.
FIG. 2 is a schematic side sectional view of a vent valve in, a closed position.
FIG. 3 illustrates the vent valve of FIG. 2 in a open position.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 provides a side partial cross-sectional view of an embodiment of a wellhead assembly 10 in accordance with the present disclosure. The wellhead assembly 10 can be used with a subsea well for controlling production fluid from within a hydrocarbon producing wellbore 11 . An outer wellhead housing 12 is provided having an annular outer conductor pipe 14 extending from its bottom end into formation 15 intersected by the wellbore. Coaxially disposed within the outer wellhead housing 12 is a high pressure/inner wellhead housing 16 . A string of surface casing 18 depends downward from the inner wellhead housing 16 and coaxial within the outer conductor pipe 14 . An outer annulus 19 is formed between the outer conductor pipe 14 and surface casing 18 .
The wellhead housing 16 coaxially circumscribes a tubing hanger 20 and production tubing 22 supported by the tubing hanger 20 . A casing hanger 24 is also coaxially landed on a shoulder 26 within the wellhead housing 16 . The shoulder 26 is formed on the inner radius of the wellhead housing 16 and projects inward towards the wellhead assembly axis A X . Casing 28 , which is supported from the bottom end of the casing hanger 24 , depends downward circumscribing the production tubing 22 . The casing 28 defines a casing annulus 30 between it and the wellhead housing 16 and surface casing 18 . A tubing annulus 32 is defined between the casing 28 and tubing 22 . A seal 34 is shown disposed, in the space between the casing hanger 24 and high pressure housing 16 , thereby isolating the casing annulus 30 from the tubing annulus 32 .
A typical production tree 36 is shown mounted on the upper end of the high pressure housing 16 ; although this may take many alternative forms and is not intrinsic to the disclosure. The production tree 36 includes a main bore 38 that is axially formed through the production tree 36 and in fluid communication with the production tubing 22 . A sealingly engaged sleeve 39 projects between the upper end of the tubing hanger 20 and the main bore 38 . The main bore 38 is selectively opened or closed with a swab valve 40 shown disposed at its upper end. A production port 42 projects laterally from the main bore 38 through the outer circumference of the production tree 36 . Flow through the production port 42 is regulated with an inline wing valve 44 .
The pressure rating of the outer conductor pipe 14 and outer wellhead housing 12 is less than the surface casing 18 and high pressure wellhead housing 16 . Pressure rating of the intermediate casing 28 is compatible with the pressure rating of the surface casing 18 and often higher. However, a leak may occur in the intermediate casing 28 or associated seals (typified by 34 ) and/or (most probably) thermal transients can cause undue pressure to become present in the annulus 30 . Under some conditions, this can cause collapse of the casing 28 (i.e. if caused by thermal transient conditions) or rupture of surface casing 18 releasing wellbore fluids directly to the adjacent environment in the latter case
An optional pressure sensor 50 is shown mounted on the outer conductor pipe 14 . The pressure sensor 50 would typically be a non-intrusive device, capable of monitoring pressure level in the annulus 30 without being in direct communication with the annulus 30 . An example of a sensor 50 is depicted in U.S. Pat. No. 5,492,017 assigned to the assignee of the present application. Measurements made by the pressure sensor 50 can be conveyed to the controller 48 via a communication link 51 connected between the sensor 50 and controller 48
A vent valve 52 is illustrated that selectively allows communication through the intermediate casing 28 between the outer annulus 30 and inner annulus 32 . In this embodiment, the vent valve 52 operates as a pressure relief valve and opens at a specific set pressure to allow communication between the casing annulus 30 and tubing annulus 32 . An embodiment of the vent valve 52 is shown in a side sectional view in FIG. 2 , wherein the valve 52 includes a cylindrical body 70 set in a port 71 formed through the casing 28 . The valve 52 may also be mounted in a special casing sub or coupling (not shown). In the embodiment of FIG. 2 , the body 70 has an inner end substantially flush, with the internal surface of the casing 28 facing the tubing annulus 32 . An outer end of the body 70 projects into the casing annulus 30 .
Still referring to FIG. 2 , a valve seat 72 is shown coaxially provided in the body 70 set in a profiled channel on the side of the body 70 in the casing annulus 30 . The valve seat 72 mid section is cylindrical having an open end facing the casing 28 . The valve seat 72 includes an “L” shaped flange that projects radially outward from the open end of the mid section and then extends axially away from the mid section and towards the casing 28 . A ring shaped metal seal 74 is set in the body 70 in a groove 75 shown circumscribing the mid section of the valve seat 72 to form a sealing surface between the valve seat 72 and body 70 . An annular cavity 76 is shown in the body 70 oriented transverse to the casing 28 ; a spring 77 is disposed in the cavity 76 . The spring 77 extends between the end of cavity 76 proximate the casing 28 and to the portion of the valve seat 72 projecting radially outward from the opening at the mid-section. Thus when compressed, the spring 77 pushes the valve seat 72 away from the casing 28 .
A channel 78 is formed in the side of the seal 74 opposite the casing annulus 30 thereby defining a space 79 between the seal 74 and bottom of the groove 75 . Flow passages 80 are shown in the body 70 that provide communication between the space 79 and the tubing annulus 32 . The sealing interface between the seal 74 and valve seat 72 and body 70 as shown in FIG. 2 blocks pressure communication between the space 79 and the casing annulus 30 . The passages 80 in the body 70 puts the side of the valve seat 72 facing the casing 28 in pressure communication with the tubing annulus 32 . The valve seat 72 is therefore exposed to any pressure differentials that may occur between the casing annulus 30 and tubing annulus 32 . Thus if the pressure in the casing annulus 30 sufficiently exceeds the pressure in the tubing annulus 32 , so that a resultant force is applied to the valve seat 72 that overcomes the force in the spring 77 . As depicted in the schematic of FIG. 3 , the pressure differential will push the valve seat 72 inward and compress the spring 77 A. Continued movement of the valve seat 72 eventually moves the mid-section of the valve seat 72 past the seal 74 thereby removing the sealing interface between the valve seat 72 and seal 74 . As such, the casing annulus 30 is in pressure communication with the tubing annulus 32 via a path that that travels through the space 79 and passage 80 . The path allows the higher pressurize fluid in the casing annulus 30 to flow through the valve 52 A to the tubing annulus 32 .
Fluid flow during venting from the casing annulus 30 to the tubing annulus 32 reduces the pressure in the casing annulus 30 ; and also reduces the pressure differential between the easing annulus 30 and the tubing annulus 32 . Removing the pressure different allows the spring 77 to reseat the valve seat 72 and reinstate the sealing interface as illustrated in FIG. 2 . This would be typified by a nominal relief setting of 500 psi on the valve, the actual value being predetermined by operator preference.
In one example of use, when pressure in the casing annulus 30 approaches a designated pressure that may potentially damage wellbore assembly 10 hardware, the vent valve 52 , automatically reverts to the open position of FIG. 3 (casing annulus 30 vented into tubing annulus 32 ) until pressure in the casing annulus 30 is below a potentially damaging pressure. The casing annulus 30 is vented until the pressure therein is no greater than 500 pounds per square inch (or some other value of the pressure setting of the valve 52 ) less than the minimum differential rating of the wellhead assembly 10 and surface casing 18 when considered together. Optionally, the pressure could be reduced yet further (for instance down to ambient pressure) in an attempt to compensate for a slow leak downhole past for instance a production packer (not shown) or tubing joint.
As a contingency, later in field life if desired, during for instance recompletion, the vent valve 52 can be overridden by installation of a contingency “patch” or sleeve 64 ( FIG. 1 ) inside the intermediate casing 18 , bridging the vent assembly. The blocking sleeve 64 is shown coaxially within the casing 28 and illustrated at an axial location adjacent the vent valve 52 . This sleeve 64 may be set in a number of ways that are typified by casing patch technology, more recent versions of this being as typified by expandable tubular systems, wherein metal casing is plastically deformed to expand out radially into contact with the casing inner diameter.
In an alternative embodiment, the production tree 36 includes an annulus line 82 that extends from the tubing annulus 32 , through the tubing hanger 20 , and to the annular space 84 between the tubing hanger 20 and the production tree 36 . The annulus line 82 has a valve that can be opened to bleed off pressure it receives from the pressurized (or leaking) casing annulus 30 in an example of use, the valve 52 allows flow only from the casing annulus 30 to the tubing annulus 32 , and not vice-versa. As indicated above, the casing annulus 30 is closed and sealed at its supper end by the seal 34 , also referred to as a casing hanger packoff. Optionally, the production tree 36 could be in a horizontal configuration, in which case the tubing annulus line 82 would bypass the tubing hanger 20 .
While the invention has been shown or described in only some of its forms, it should be apparent to those skilled in the art that it is not so limited, but is susceptible to various changes without departing from the scope of the invention. For example, the vent valve 52 can be of the form found in Fenton et al. U.S. Pat. No. 6,840,323, which is assigned to the assignee of the present application and incorporated by reference herein. Optionally, the vent valve 52 can be made of a valve member urged closed by a resilient member, such as a spring, that compresses in response to a designated pressure differential.
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A wellbore tubular set concentrically between an inner an and outer annulus has a pressure relief valve that opens when pressure in the outer annulus exceeds pressure in the inner annulus by an amount that can damage the tubular. The relief valve closes and reseats when the pressure differential is reduced to below the damaging threshold. The relief valve can include a spring for reseating the valve. A pressure gauge can be included within the outer annulus for monitoring whether or not the relief valve is operating properly.
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BACKGROUND
Stretching is a form of physical exercise in which a specific skeletal muscle or muscle group is deliberately elongated, often by abduction from the torso, in order to improve the muscle's felt elasticity and reaffirm comfortable muscle tone. The result of stretching is a feeling of increased muscle control, flexibility and range of motion. Stretching is also used therapeutically to alleviate cramps. Increasing flexibility through stretching is one of the basic tenets of physical fitness. It is common for athletes to Stretch before and after exercise in order to reduce injury and increase performance.
Yoga involves the stretching of major muscle groups, some of which require a high level of flexibility to perform, for example the lotus position. Stretching can strengthen muscles, and in turn strong muscles are important to stretching safely and effectively. Stretching can be dangerous when performed incorrectly. There are many techniques for stretching in general, but depending on which muscle group is being stretched, some techniques may be ineffective or detrimental, even to the point of causing permanent damage to the tendons, ligaments and muscle fiber. The physiological nature of stretching and theories about the effect of various techniques are therefore subject to heavy inquiry.
There are many beneficial stretches that can improve range of motion (ROM) in athletes, especially runners. Certain stretching techniques and protocols prevent injuries when performed (within 15 minutes) prior to exercise. It is also suggested that one stretching exercise may not be enough to prevent all types of injury, and therefore, multiple stretching exercises should be used to gain the full effects of stretching. It has also been suggested that proprioceptive neuromuscular facilitation (PNF) stretching yield the greatest change in range of motion, especially short-term benefits. Reasoning behind the biomechanical benefit of PNF stretching points to muscular reflex relaxation found in the musculotendinous unit being stretched. Others suggest that PNF benefits are due to influence on the joint where the stretch is felt.
Stretching can be used for various purposes including: preparation, maintenance and development. Preparatory Stretching is focused on getting the muscles ready for exercise. The aim of preparatory stretching is to help prepare the muscles for exercise, this will reduce the risk of injury and improve performance during the exercise. Preparatory stretches should be performed after a warm up exercise and should be focused on the muscle groups that are going to be used during the exercise session.
Maintenance stretching is generally performed after a main exercise session. The purpose of maintenance stretching is to return the muscles back to their normal length. Stretching after your main exercise session is one of the most neglected areas of fitness. Looking after a body's flexibility by stretching will reduce the risk of injury, muscle tension, the risk of lower back pain and improve muscle coordination.
Developmental Stretching is also generally performed at the end of an exercise session. Developmental Stretches focus on increasing the muscle length or muscle flexibility. Developmental stretches are an excellent way of increasing your flexibility, usually performed after the main exercise session they are designed to improve your range of movement. Developmental stretching can be used to correct posture, reduce muscle cramps and gain more flexibility.
Most stretching is performed by moving the body in specific ways to elongate target muscles. In some cases, a hand may be needed to grasp another portion of the body and stretch a muscle. In other cases, the individual may lean against a stationary object to elongate the target muscle.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front elevational view of a motorized stretching machine built in accordance with the preferred embodiment of the present invention with its foot rest apparatus in an elevated position.
FIG. 2 is a front elevational view of a motorized stretching machine built in accordance with an embodiment of the present invention with the foot rest apparatus in a lowered position.
FIG. 3 is a front sectional view of the lower portion of a motorized stretching machine built in accordance with an embodiment of the present invention with the foot rest apparatus in a lowered position.
FIG. 4 is a front sectional view of the upper portion of a motorized stretching machine built in accordance with an embodiment of the present invention.
FIG. 5 is a front perspective view of a motorized stretching machine built in accordance with an embodiment of the present invention with a user's foot on its foot rest pad.
FIG. 6 is a front perspective view of a motorized stretching machine built in accordance with an embodiment of the present invention with a user's foot in its loop belt.
FIG. 7 is a front perspective view of a motorized stretching machine built in accordance with an embodiment of the present invention with a user grasping a cord handle.
FIG. 8 is a front elevational view of a motorized stretching machine built in accordance with an alternate embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings and in particular FIGS. 1, 2, 3, 4, 5, 6, and 7 , a motorized stretching machine 100 built in accordance with the preferred embodiment of the present invention is defined by a freestanding, elongated base frame 110 having a two proximal frame members 111 and two distal frame members 112 , each of which extend vertically between a base stand 113 and a top section 114 . Attached to the each of the proximal frame members 111 is a hand grip frame 120 defining a plurality of grip bars 121 arranged with as polygon with two crossbars, a lateral hand bar 122 , and a front hand bar 123 . Extending in front of the motorized stretching machine 100 from the bottom of each proximal frame member 111 is a rigid foot stand 130 that includes a sloped front 131 and a substantially flat top 132 .
Integral with the motorized stretching machine 100 is a motorized assembly which defines an electric motor 140 mounted to the top section 114 , a slide track 141 oriented substantially vertically between the electric motor 140 and the base stand 113 , and a foot rest apparatus 142 slidably disposed on the slide track 141 . In the preferred embodiment, the foot rest apparatus 142 is coupled with a cable 143 that extends from a spool (not shown) inside the electric motor 140 . Accordingly, operating the electric motor 140 to rotate in a first direction causes the foot rest apparatus 142 to rise towards the electric motor 140 while operating the electric motor 140 to rotate in a second, opposing direction causes the foot rest apparatus 142 to be lowered away from the electric motor 140 towards the base stand 113 .
It is appreciated that in some embodiments, the electric motor 140 may additionally include an internal gearing system so as to enable the speed or torque of the electric motor's rotation of the cable 143 around the spool to be controlled or to cause the foot rest apparatus 142 to be held in place when the motor 140 is off.
The slide track 141 operates as a guide rail along which the foot rest apparatus 142 is moved vertically between the electric motor 140 to the base stand 113 . In the preferred embodiment, the slide track 141 defines two discrete pole members which each extend from the electric motor 140 to the base stand 113 in a substantially parallel orientation relative to the distal frame members 112 . In such an embodiment, the foot rest apparatus 142 is coupled to each pole member of the slide track 141 , thereby preventing the foot rest apparatus 142 from revolving or twisting while stationary or while being moved by the electric motor 140 .
In one embodiment, the slide track 141 is oriented such that it tilts at set angle between 3% and 15% from the bottom of the slide track 141 to the top of the slide track 141 (being further from the user at the top than the bottom). Advantageously, this tilted slide track 141 allows a user to obtain the maximum stretch because as the user's leg raises, it does not extend as much horizontally. In one embodiment, the slide track tilts at a 10% or 12% angle. In other embodiments, the slide track 141 is oriented such that it tilts at set angle between 5% and 15%, 8% and 12%, 5% and 10%, or 7% and 15%.
In some embodiments, the slide track 141 angle is adjustable.
In the preferred embodiment, the foot rest apparatus 142 includes a base section 142 ′ having a foot rest pad 143 , a loop belt 144 which hangs from the front of the base section 142 ′, a plurality of step bars 145 positioned above the foot rest pad 143 , and a lower cord 146 which extends vertically from the bottom of the base section 142 ′. In some embodiments, two cord handles 147 is attached to the end of the lower cord 146 opposite its attachment to the base section 142 ′.
In the preferred embodiment, a base pulley 115 is disposed on the base stand 113 and is operative to receive the lower cord 146 , thereby allowing the direction of operation of the lower cord 146 to be changed so as to operate along a substantially horizontal plane.
It is contemplated that the electric motor 140 is manually operated through a plurality of push buttons 148 operative as biased, momentary push-button switches, disposed in various locations on the elongated base frame 110 , hand grip frames 120 , and/or foot stands 130 , including on both the left and right sides, respectively, thereon. As such, it is appreciated that the elongated base frame 110 , hand grip frames 120 , and foot stands 130 include internal electrical wiring which operatively connect a power source, defined in the illustrated embodiment as an electrical cord 149 , the electric motor 140 , and each of the push buttons 148 .
In an embodiment, the push buttons 148 can be color coded. For example, in an embodiment green buttons are pressed to cause the foot rest apparatus 142 to rise and red buttons are pressed to cause the foot rest apparatus 142 to be lowered. In other embodiments any other color scheme can be used to indicate the operative features of the stretching machine.
In other embodiments, the locations of the buttons can indicate the associated control function. For example, a push button 148 the right side foot stand 130 may cause the foot rest apparatus 142 to rise (as such, a “retract push button”) and push button 148 the left side foot stand 130 may cause the foot rest apparatus 142 to be lowered (as such, a “deploy push button”). Such may be implemented with or without color coding.
It is appreciated that by including push buttons 148 on the elongated base frame 110 , hand grip frames 120 , and foot stands 130 , a user will generally be able to operate the foot rest apparatus 142 no matter what area of the body is being stretched. For example, push buttons 148 in certain locations may be more or less accessible to a user doing upper or lower back stretches.
In typical embodiments, the push buttons 148 operate as push to make electrical switches. In some embodiments, the electrical motor 140 only operates while the push button 148 is pressed. In other embodiments, the electrical motor 140 includes a programmable timer function which allows it to automatically operate for a set period of time once one of the push buttons 148 has been actuated. For example, in such an embodiment, a user can press one of the push buttons 148 to cause the motor 140 to either hold the foot rest apparatus 142 in place or move the foot rest apparatus 142 in a desired direction for a set duration (such as 10 or 15 seconds), allowing a user to hold a desired stretch for the duration without having to hold the push button 148 .
While the push buttons 148 generally define biased momentary switches, in some embodiments, the push buttons 148 may operate as a toggle on/off switch.
When in use, a user can stand in front of motorized stretching machine 100 and place his foot in the loop belt 144 or on the foot rest pad 143 then hold onto one or two of the hand grip frames 120 . The user can then press one of the retract push buttons 148 to cause the motor 140 to retract the cable 143 upwards to stretch the user's leg and leg muscles. When the user wishes to stop the movement, he/she can release the push button 148 . When the user wishes to return to a normal position, the user can press one of the deploy push buttons 148 to cause the motor 140 to unspool the cable 143 to lower the user's foot out of the stretched position. Below are some possible stretches that can be performed with the motorized stretching machine 100 . In general, the machine is used with the user standing or seated in front of the motorized stretching machine 100 .
Stretching Gluteus Maximus Muscles. This stretch can start with the user standing sideways with the body approximately perpendicular to the front of the motorized stretching machine 100 , facing the left hand grip frame 120 to stretch the left gluteus maximum muscle. The user brings his/her left leg into the loop belt 144 or on the foot rest pad 143 (while in the lowered position) and may hold onto a bar on the left hand grip frame 120 in the middle torso height. By pressing one of the retract push buttons 148 , the user starts to feel the stretching into the gluteus maximus as the foot rest apparatus 142 raises. The body position relative to the machine can be switched to stretch the right gluteus maximum muscle.
Stretching Lower Back Muscles. As illustrated in FIG. 7 , this stretch can start with the user sitting down in front of the machine and placing the right and left foot on the corresponding foot stands 130 on the front edge of the motorized stretching machine 100 . A user the holds the cord handle 147 with one or both hands in order to be pulled forward. The user can control the stretch (namely, raise and lower the foot rest apparatus 142 ) by using the push buttons 148 on the foot stands 130 with the right or left foot.
Stretching Latissmus Dorsi Muscles. This stretch can start with the user sitting down and possibly placing the right and left foot on the corresponding foot stands 130 . The user can hold the loop belt 144 and optionally the hand grip frame 120 opposite the side to be stretched, controlling the foot rest apparatus 142 by using the push buttons 148 on the foot stands 130 .
Stretching Hamstring Muscles. As illustrated in FIG. 6 , this stretch can start with the user directly facing the machine, holding onto the right and left hand grip frames 120 with the respective hand, and placing foot of the target leg on the loop belt 144 . The foot rest apparatus 142 can then be raised to actuate the stretch using the push buttons 148 on the hand grip frames 120 .
Stretching Abductor Magnus Muscles. As illustrated in FIG. 5 , this stretch can start with the user standing sideways in front of the motorized stretching machine 100 . The user places their right foot onto the foot rest pad 143 . The user can hold the left side hand grip frame 120 with both hands. The foot rest apparatus 142 can then be raised to actuate the stretch using the push buttons 148 on the hand grip frame 120 . The body position is reversed to stretch the left abductor magnus muscles.
Stretching Quadriceps Muscles. This stretch can start with the user facing away from the motorized stretching machine 100 . The user must place one foot behind their body into the loop belt 144 and the user's left hand can grasp the left hand grip frame 120 at a lower torso height and the user's right hand can grasp the right hand grip frame 120 at a lower torso height. The user must hold onto the hand grip frame 120 and use the push buttons 148 thereon to control the stretch.
Stretching Hip Muscles. This stretch can start with the user facing forward. The user places one foot on the loop belt 144 , bending the knee forward and holding the hand grip frame 120 while pushing the push buttons 148 thereon to control the stretch.
Stretching Chest Muscles. This stretch can start with the user facing away from the motorized stretching machine 100 . The user holds right and left hand grip frames 120 while slowly leaning further away from the machine until the user feels the stretch.
Stretching Calf Muscles. This stretch can start with the user facing forward and placing one foot on top of the foot stand 130 . By lowering the heal, the user will feel the stretch.
Suspended Stretch for Several Muscles Groups. This stretch can start with the user facing forward. The user can place both feet on the foot rest pad 143 , holds onto right and left hand grip frame 120 and pushes a retract push button 148 to the desired level of stretch. Once user is satisfied with current stretch, he can obtain a different stretch by reaching for opposite sides of the hand grip frame 120 while the user's feet remain suspended on the foot rest pad to engage different muscles group stretches, such as Latissmus dorsi, Shoulder Muscles, neck, Oblique Muscles and triceps.
Referring now to FIG. 8 , in an alternate embodiment of the motorized stretching machine 200 , a single elongated foot bar 230 is used in place of the dual rigid foot stands.
In all embodiments, it is generally contemplated that the hand grip frames provide the user full stability and control while stretching. The hand grip frames also allow the user to engage several different muscles groups at the same time instead of just focusing on one muscle group. While the hand grip frames generally include a left side mounted on the left side of the slide track and a right side mounted to the right side of the slide track, it is contemplated that other orientations may be employed. The hand grip frame can include a plurality of bars that extend horizontally relative to the left and right sides of the slide track. In one embodiment, the hand grip frame can have the following horizontal grip bars: upper, upper middle, lower middle and lower. The hand grip frame can also include vertical grip bars that extend parallel to the slide track and are coupled to the ends of the horizontal members as well additional grip bars on a wider portion of the frame that extend from the left and right sides of the plurality of grip bars that extend horizontally.
The foot rest apparatus is generally an elongated horizontal structure that moves vertically along the slide track and includes features that provide multiple user options. For example, many embodiments the foot rest apparatus include a foot rest pad and a loop belt. The user may choose to use either the pad or belt depending upon the type of stretching being performed. The pad can be a padded structure that rests on top of a base section of the foot rest. The pad can allow a user to place a foot on top of the foot rest comfortably while the foot rest moves vertically along the slide track. The user can also put his or her foot in the belt below the foot rest. The belt can be a flexible structure that can be made of fabric, webbing, plastic, rubber or any other suitable material or structure. The belt is generally coupled to the bottom of the foot rest, but may be attached in other areas. The user may place a foot in the belt which can partially surround the foot. The belt may also be padded to improve the comfort to the user.
The motor can be any type of suitable electric motor including: synchronous and asynchronous DC motors and AC motors. In an embodiment, the motor can be a stepper motor which is similar to a three-phase AC synchronous motors. Unlike a synchronous motor, in its application, the stepper motor may not rotate continuously; instead, it “steps”—starts and then quickly stops again—from one position to the next as field windings are energized and de-energized in sequence. Depending on the sequence, the rotor may turn forwards or backwards, and it may change direction, stop, speed up or slow down arbitrarily at any time. Simple stepper motor drivers entirely energize or entirely de-energize the field windings, leading the rotor to “cog” to a limited number of positions; more sophisticated drivers can proportionally control the power to the field windings, allowing the rotors to position between the cog points and thereby rotate extremely smoothly. This mode of operation is often called micro-stepping. Computer controlled stepper motors are one of the most versatile forms of positioning systems, particularly when part of a digital servo-controlled system. Stepper motors can be rotated to a specific angle in discrete steps.
The slide track is generally a track that supports the foot rest and guides the foot rest apparatus as it slides vertically relative to the elongated base frame of the motorized stretching machine. The slide track can include linear-motion bearings that will allow the foot rest to move smoothly with minimal friction. A linear-motion bearing or linear slide is a bearing designed to provide free motion in one dimension. There are many different types of linear motion bearings including rolling element bearings, ball bearing slides, plain bearings, dove tail slides.
A rolling-element bearing is generally composed of a sleeve-like outer ring and several rows of balls retained by cages. The cages were originally machined from solid metal and were quickly replaced by stampings. It features smooth motion, low friction, high rigidity and long life. They are economical, and easy to maintain and replace.
Ball bearing slides offer smooth precision motion along a single-axis linear design, aided by ball bearings housed in the linear base, with self lubrication properties that increase reliability. Ball bearing slides are commonly constructed from materials such as aluminum, hardened cold rolled steel and galvanized steel, ball bearing slides can consist of two linear rows of ball bearings contained by four rods and located on differing sides of the base, which support the carriage for smooth linear movement along the ball bearings.
Roller slides also known as crossed roller slides are linear slides that provide low friction linear movement. Roller slides consist of a stationary linear base and a moving carriage, roller slides work similarly to ball bearing slides, except that the bearings housed within the carriage are cylinder-shaped instead of ball shaped. In an embodiment, the rollers crisscross each other at a 90° angle and move between the four semi-flat and parallel rods that surround the rollers. The rollers can be between “V” grooved bearing races, one being on the top carriage and the other on the base. The travel of the carriage ends when it meets the end cap, a limiting component. Typically, carriages are constructed from aluminum and the rods and rollers are constructed from steel, while the end caps are constructed from stainless steel.
Plain bearings are very similar in design to rolling-element bearings, except they slide without the use of ball bearings. Plain bearings can run on hardened steel or stainless steel shafting (raceways), or can be run on hard anodized aluminum or soft steel or aluminum. The specific type of polymer/fluoro-polymer will determine what hardness is allowed.
Dovetail slides, or dovetail way slides are typically constructed from cast iron, but can also be constructed from hard-coat aluminum, stainless steel or other suitable materials Like any bearing, a dovetail slide is composed of a stationary linear base and a moving carriage. A dovetail carriage can have a V-shaped, or dovetail-shaped protruding channel which locks into the linear base's correspondingly shaped groove. Once the dovetail carriage is fitted into its base's channel, the carriage is locked into the channel's linear axis and allows free linear movement. When a platform is attached to the carriage of a dovetail slide, a dovetail table is created, offering extended load carrying capabilities,
Since dovetail slides have such a large surface contact area, a greater force is required to move the saddle than other linear slides, which results in slower acceleration rates. Dovetail slides are capable of long travel, dovetail slides are more resistant to shock than other bearings, and they are mostly immune to chemical, dust and dirt contamination.
In another embodiment, the motor can be coupled to a threaded rod that extends along the slide track. The foot rest apparatus can have a corresponding threaded mechanism that engages the threaded rod. The motor can spin the rod in a first direction which causes the foot rest to rise or spin in the opposite direction which causes the foot rest to be lowered. In other embodiments, other mechanisms can be coupled to the motor to move the foot rest apparatus.
The base frame and hand grip frames of the motorized stretching machine can be fabricated from any suitable bar stock material that can be securely fastened together. In an embodiment, the base frame and hand grip frames can be made of metal pipe or tubing that is strong enough to support the weight of a user and of a diameter that is comfortable to grip. The pipes/tubing can be any suitable metal, plastic or composite material, such as steel, copper, aluminum, PVC, Kevlar, carbon fiber, etc. The preferred diameter of the grip bars of the hand grip frames can be about ½ inch to 2 inches in diameter. The pipes/tubes can be cut to the required lengths and then coupled together in an appropriate manner to create the hand grip frame. For example, metal pipe pieces can be welded or fastened together to create the hand grip frame. Alternatively, plastic or composite pipe pieces can be bonded, fastened or molded together to create the hand grip frame.
The push buttons are coupled to the electric motor and the electrical power source so that when any push button is pressed, the electrical power is supplied to the motor to cause the motor to generate rotate in a first or second opposing direction. If a DC motor and power supply are being used, the switches can apply the DC power in a first polarity to the DC motor when the raise button is pressed and conversely, a second polarity that is opposite the first polarity to the DC motor when the lower button is pressed. If both the raise and lower buttons are both pressed simultaneously, the electrical system can stop power from being applied to the DC motor and also prevent an electrical power supply short circuit.
In other embodiments, the motor can be stepper motor that is coupled to a control computer. The computer can be configured to provide specific operating controls to the stepper motor such as movement speed limitations, movement distance limitations, etc. The limitations can be set for all users or set for individual users and can provide an additional safe guard against improper use. For example, the system can be configured to move the foot rest apparatus at a first speed but slow the foot rest apparatus down as it approaches the movement distance limits of a designated user.
It is appreciated that the motorized stretching machine can assist in activities ranging from rehabilitation and physical therapy to competitive athletics.
It is contemplated that in alternate embodiment, the motor may be integrated with or adjacent to the base stand as opposed to the top section.
In some embodiments, one or both foot stands are constructed as a fixed member without any integrated or connected push buttons.
In some embodiments, an integrated vertical measurement scale is positioned adjacent to the slide track and running parallel thereto. An example of such a scale is illustrated in FIG. 1 as reference number 150 . It is contemplated that a single scale may be provided on one of the slide tracks, or dual scales may be provided, with each adjacent to the slide track on disposed on either side of the cable. In one embodiment, measurement markings are included on the one or both of the actual slide track.
The present invention has been shown and described herein in what is considered to be the most practical and preferred embodiment. It is recognized, however, that departures may be made therefrom within the scope of the invention and that obvious modifications will occur to a person skilled in the art.
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A motorized stretching machine for enabling a user to perform stretches targeting areas throughout their body includes a metal base frame with an integral slide track on which a motor driven foot rest apparatus is mounted, a plurality of hand grip frames that enables many different hand grips, and a plurality of foot stands. A plurality of push buttons are disposed in various locations on the right side and left side to allow the user to control the operation of the motor driven foot rest apparatus. The varied positioning of the push buttons facilitates full control during stretches and full stability because the user can hold onto other parts of the machine to assist with balance while actuating the motor control buttons. Advantageously, the overall design helps users engage selected muscle groups without losing balance or flexing any other muscles so the user can enjoy a full stretch.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This patent application is based upon, and claims the benefit of, Provisional U.S. Patent No. 60/245,149, Attorney Docket No. 00P9024US, entitled VIDEO-SUPPORTED VIRTUAL PLANT DESIGN (VPA), filed Nov. 3, 2000, the disclosures of which are incorporated by reference herein in their entirety.
FIELD OF THE INVENTION
[0002] This invention relates to computer-assisted installation of equipment in rooms.
BACKGROUND OF THE INVENTION
[0003] Buyers and/or suppliers of equipment need to plan where to put said equipment in their existing/new/in-planning facilities. For instance, during the construction of manufacturing plants, and after the civil construction of the plant building is already completed, the design engineer plans the positioning of the many components of the factory (manufacturing machines, storage areas, . . . ), within the physical constraints imposed by the completed structure. Another example is the installation of MRI (magnetic resonance imaging) machines in hospital rooms. In this case, the manufacturer needs to plan the way to get the machine into the right room on the right floor (the basement for instance) and to plan where to place the machine in the room. The problem is constrained by the fact that a MRI machine produces a strong magnetic field and that no metallic equipment should be within its reach. A third example would be maintenance and repair work in electricity-generating plants (gas plants, etc. . . . ). Maintenance equipment needs to be brought in (temporarily). Equipment that has to be replaced needs to be brought out. The replacing equipment needs to be brought in. All this equipment movement has to be planned. Planners need to check that there is enough room to move said equipment as planned.
SUMMARY OF THE INVENTION
[0004] Disclosed is a room planning and design system, comprising a virtual room space comprising a virtual representation of a physical room space, an object library of virtual objects, said virtual objects comprising virtual representations of equipment, machines and objects that may be placed in a room, a user interface comprising a first user interface component for selecting said virtual objects from said virtual library and positioning them in said virtual room space, a second user interface component for manipulating the positions and orientations of said virtual objects within said virtual room space, a workspace comprising a physical model of said physical room space, physical marker objects substantially scaled to said workspace for manual placement and orientation of said markers objects in said workspace, one or more detectors for detecting information regarding the positioning of said marker objects in said workspace and transmitting said information to a visualization module, and said visualization module adapted to receive said information from said detectors and utilize said information for positioning said virtual objects within said virtual room space.
[0005] In another aspect of the system, said detected information comprises the positioning of said marker objects comprises both the placement and orientation of said marker objects, and said visualization model utilizes said information to both place and orient said virtual objects within said virtual room space.
[0006] In another aspect of the system, said physical room space is a factory plant.
[0007] In another aspect of the system, said physical room space is a medical facility.
[0008] In another aspect of the system, at least one of said virtual objects is an MRI machine.
[0009] In another aspect of the system, said object library of virtual objects comprises data stored in a computer-readable media.
[0010] In another aspect of the system, each said virtual object further comprises data regarding the motion of said virtual object, useable by the user to animate said virtual object on said visual display.
[0011] Another aspect of the system further comprises a third user interface component for permitting the user to virtually move about said virtual room space.
[0012] In another aspect of the system, said workspace is a table.
[0013] In another aspect of the system, said detector comprises at least one camera.
[0014] In another aspect of the system, said marker objects further comprise markings thereon that yield identification information to said detector.
[0015] In another aspect of the system, said marker objects further comprise markings thereon that yield orientation information to said detector.
[0016] Disclosed is a method of room planning and design, comprising obtaining a virtual room space comprising a virtual representation of a physical room space, loading an object library comprising virtual objects, selecting an virtual object, receiving positioning information from a user through a workspace comprising a physical model of said physical room space, positioning said virtual object in said virtual room space in accordance with said positioning information, and wherein said receiving of positioning information from a workspace comprises receiving from a detector the positioning of marker object manually positioned within said workspace by the user.
[0017] Another aspect of the system further comprises the step of selecting an active working plane for said positioning of said virtual object.
[0018] Disclosed is a program storage device, readable by machine, tangible embodying a program of instructions executable by the machine to perform method steps for room planning and design, said method steps comprising obtaining a virtual room space comprising a virtual representation of a physical room space, loading an object library comprising virtual objects, selecting an virtual object, receiving positioning information from a user through a workspace comprising a physical model of said physical room space, positioning said virtual object in said virtual room space in accordance with said positioning information, and wherein said receiving of positioning information from a workspace comprises receiving from a detector the positioning of marker object manually positioned within said workspace by the user.
[0019] Another aspect of the system further comprises the step of selecting an active working plane for said positioning of said virtual object.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] [0020]FIG. 1 shows a flowchart of an embodiment of the invention.
[0021] [0021]FIG. 2 shows a display of a virtual room space containing virtual objects (pieces of equipment).
[0022] [0022]FIGS. 3 a and 3 b show a physical model of the room space.
[0023] [0023]FIGS. 4 a through 4 d shows the building up of a virtual room space with virtual equipment.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0024] Referring to FIGS. 1 and 2, there is shown a flowchart of a preferred embodiment of the invention, which begins with preferably a 3D virtual representation of the physical room, though the methods of this invention may be applied to simple 2D floor plan representations. When starting up, the current state of the physical room or of the room design is displayed on a display device, generally a computer monitor. A typical display is shown in FIG. 2. This might include walls, steel construction, etc. The user of the system might be a design engineer, a plant designer, a maintenance planner, a room planner, a planner of the installation of new equipment in a room, etc. The user needs to add various virtual objects (for instance pieces of equipment) to the virtual representation of the room space until the room (new or updated) design is complete. Several users can also use the system simultaneously. Our system is a collaborative user interface that helps the user(s) better visualize different possible designs and optimally position each of the room objects, thereby aiding room design. The system will preferably permit the user to virtually move around the plant, to get information about each virtual object in the virtual room 210 , to manipulate said objects and to control 3D animations. When the designer has placed all the room components, he can export the positions, orientations and scaling of the complete model to a CAD-system. The complete design can also visualized in 3D using Virtual Reality or Augmented Reality techniques. Virtual objects can also be visualized in real images of the physical room.
[0025] A preferred process flow of the invention, which will be executed on a computer or equivalent processing device, begins with obtaining the virtual plant or room space 100 , which may be inputted through known electronic or computer means as a collection of coordinate points or 3D model files (VRML or CAD) or other useful formats known to the literature. Next, an object library is loaded 110 and a working plane selected 120 . The working plane determines the vertical height at which objects will be inserted into the virtual room space.
[0026] The object library contains the virtual objects (for instance pieces of equipment) that may be placed in the virtual room space. It may be a collection of custom objects for the job at hand or a collection of generic stock objects for general use. The user selects 130 the object he now wishes to work on. The system puts itself into position input mode 140 . It waits for input from the user 150 . Positioning information is received 160 from the user. Positioning information may only comprise placement (i.e., location) information, but in a preferred embodiment will also comprise orientation information. The 3D model of the object is recovered from the library 170 by a first user interface component. Then the virtual object is positioned 180 into the virtual world according to the information gathered in 160 . Alternatively, the system may select a default position and then allow the user to manipulate the placement of the object.
[0027] Node 190 is a selection box wherein the user may continue to move around the object through another user interface component until he is satisfied with it's positioning, or he may select a different object and begin moving it around. He may also choose to move to a different working plane or simply exit to node 199 . The choice by default could be to continue positioning without querying the user until the user gives a specific input (keyboard input, mouse click, menu choice, etc. . . . ) that indicates that he/she is done with positioning.
[0028] [0028]FIGS. 3 a and 3 b show the preferred input device of the invention. A surface 300 is provided that acts as a physical model of the layout of the room space. This surface may be as complex and detailed or as simple as desired. It could simply be a flat table surface, possibly with a visible grid coordinate system 310 and perhaps either an overlay of the floor plan of the room, or a projection thereof (not shown). A detector 320 is provided, such as a video camera or other detection means that may collect information on the positioning (i.e., placement and/or orientation) of physical objects placed on the table 300 . Markers 330 may be placed at the corners or other places of the workspace to delineate the space. This would aid the system in mapping the physical workspace above surface 300 to the virtual room space. Objects known to the system (flat 2D markers, 3D objects with or without markers, props, etc. . . . ) 340 may then be manually placed and moved about or above the surface of the workspace 300 and detected by the detector 320 . These “marker objects” being moved in the workspace 340 will preferably have markings or other identifiers on them to allow the detector to determine certain information, such as orientation and identity. Hence, a cross might be set up to represent a drill press, a circle a lathe, and so forth. Alternatively, the marker objects can have such distinctive shapes that they can be easily differentiated by the system without the need for added markings or identifiers for that purpose.
[0029] When the user moves these 2D markers or 3D markers or 3D objects 340 on the surface 300 , detector 320 perceives it. For example, using a camera detector, the system may use known image processing techniques to determine from the camera images the positioning of the markers on or above the desk at regular time intervals. This information is then sent to a visualization module of the system, which uses this information to move and animate the different components of the room represented by the marker objects. This gives the designer an easy-to-use intuitive way to interact with the virtual room space. By moving marker objects on the desk and associating these objects with components of the 3D room model, the designer can easily test different positions of an object in the 3D room model. In the same way, the designer can also define possible motions, animations, and trajectories for mobile objects (for instance, forklifts). One further advantage of such an interface is that it is collaborative: several people can discuss the positioning of equipment in a room (for instance machines in a factory or equipment in a hospital) and jointly interact with the 3D model through the interface provided by this system.
[0030] In this set-up, we can use marker objects made out of any material (wood, paper, plastic). The objects can have a variety of shape and markings, as long as they are known to the system and the system can differentiate between them. We can use a standard camera that takes images in the visible spectrum or, alternatively, we can use a camera equipped with a ring of infrared-emitting diodes and a filter that allows only infrared light in. With such a camera, markings made out of retro-reflective material need to be pasted onto the marker objects to differentiate them. The system could also use several cameras simultaneously (cameras observing the workspace from different angles)
[0031] Referring to FIGS. 4 a through 4 d , there is shown the building up of a virtual room space through the manipulations of real objects on a table by the user. In FIG. 4 a a virtual object is chosen and recovered from the virtual library ( 400 ), either by direct input by the user or by image processing identification of markings on a marker object on the table. The positioning of the marker object in the physical workspace is detected and used to position the first chosen virtual object 210 a into the virtual room space. In FIG. 4 c we see a second virtual object 210 b added to the virtual room space 200 , according to the positioning of another real-world marker object on the table (or any other surface or space that defines the physical workspace). Any of these virtual objects may also rotate in the next detector interval if the user has changed the orientation of the corresponding physical object.
[0032] Referring to FIG. 4 c , we see how a third virtual object 210 c may be positioned on a different level. Even thought the real-world surface may be of only one height, the user may direct the system to change the height of the active plane 200 ′ so that the active plane 200 ′ is now displaced from the original active plane. The third chosen marker object will be the same physical height as the other objects on the table, but in the virtual world, it can be seen that the corresponding third virtual object 210 c is at a different level than the other objects. This can be seen on the display by the user as he manipulates the objects on the table.
[0033] As can be seen, the invention provides an easy-to-use tool for planning the installation of equipment and/or the design of a room. It can be used collaboratively by several people simultaneously. It can also be used in a distributed set-up, between users having a teleconference from different sites. A physical workspace (a tabletop for instance) is associated to the virtual space of the room that is being planned. A 3D visualization tool shows the virtual layout of the room. The physical workspace is equipped with detectors. Real physical objects are used to embody virtual objects in the physical workspace. By moving these physical objects in the workspace, the user can move the virtual objects in the virtual room. Thus the movements and installations of objects in rooms can be planned in an easy and quick way.
[0034] The 3D visualization part of our system incorporates all the object positioning functionality discussed so far, but preferably also a user inter component enabling the user to virtually move about in the virtual world as it is created, manipulating and animating the virtual objects therein.
[0035] A preferred embodiment of the system of the invention will therefore utilize a camera system and a 3D visualization tool (a “3D browser”) and will provide the following functionality:
[0036] Selection of the working plane in the 3D browser
[0037] Calibration of the working plane to a planar surface observed by the camera(s) (using a homography)
[0038] Selection of the virtual objects/assignment of real-wold marker objects to 3D virtual objects
[0039] Translation and rotation of virtual objects by moving the corresponding marker objects in the workspace observed by the camera(s)
[0040] Calibration of the camera(s) using calibration patterns (optional)
[0041] Navigation through a menu associated with each 3D virtual object
[0042] Switch between relative and absolute 3D coordinates
[0043] Export of object coordinates and scale to other systems (VRML-based, CAD-based, etc. . . . )
[0044] The methods of the invention may be implemented as a program of instructions, readable and executable by machine such as a computer, and tangibly embodied and stored upon a machine-readable medium such as a computer memory device.
[0045] It is to be understood that all physical quantities disclosed herein, unless explicitly indicated otherwise, are not to be construed as exactly equal to the quantity disclosed, but rather as about equal to the quantity disclosed. Further, the mere absence of a qualifier such as “about” or the like, is not to be construed as an explicit indication that any such disclosed physical quantity is an exact quantity, irrespective of whether such qualifiers are used with respect to any other physical quantities disclosed herein.
[0046] While preferred embodiments have been shown and described, various modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustration only, and such illustrations and embodiments as have been disclosed herein are not to be construed as limiting to the claims.
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Disclosed is a room planning and design system, comprising a virtual room space comprising a virtual representation of a physical room space, an object library of virtual objects, said virtual objects comprising virtual representations of equipment, machines and objects that may be placed in a room, a user interface comprising a first user interface component for selecting said virtual objects from said virtual library and positioning them in said virtual room space, a second user interface component for manipulating the positions and orientations of said virtual objects within said virtual room space, a workspace comprising a physical model of said physical room space, physical marker objects substantially scaled to said workspace for manual placement and orientation of said markers objects in said workspace, one or more detectors for detecting information regarding the positioning of said marker objects in said workspace and transmitting said information to a visualization module, and said visualization module adapted to receive said information from said detectors and utilize said information for positioning said virtual objects within said virtual room space.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to computer graphics, and more particularly to the generation of planar maps of three-dimensional surfaces.
2. Related Art
The problem of flattening a three dimensional (3-D) surface into a two-dimensional (2-D) domain is age old and takes several forms.
For example, one of the central concerns of cartography is the representation of a sphere as a planar map. As is well known, it is impossible to represent such a surface in 2-D without distortion and discontinuity. In a Mercator projection, for example, Greenland appears much larger than it really is in relation to more southern countries. Cartographers mitigate this problem either by cutting the surface of the globe into segments, thus trading off increased discontinuity for decreased distortion, or by using other projections which trade off size distortions for shape distortions.
Other application areas involve surface flattening, or the inverse problem, the construction of 3-D surfaces from originally flat components. An example of flattening involves taking the hide of an animal and creating flat pieces of leather or fur. An example of the inverse process is the construction of apparel such as shoes and garments out of pieces of leather, fur, or cloth. Going in either direction involves stretching/shrinking (distortion) and the alteration of discontinuity/continuity (e.g., by cutting or sewing).
The problem of correspondences between flat and curved surfaces arises in computer graphics software. A technique known as texture mapping is used to give 3-D surfaces character and realism. Whenever there exists a mapping from a 3-D surface to a 2-D region, an arbitrary image can be identified with the 2-D region so that rendered attributes of the surface (e.g., color, shininess, displacement) are controlled by the image's values. An image used in this way is called a texture map.
For 3-D surfaces such as bicubic patches, the mapping from surface to a 2-D region is intrinsic. However, for 3-D surfaces composed of polygons, an a priori mapping does not exist. The construction of such mappings, known as parameterization, has been a problem in computer graphics for several years because without a parameterization a polygonal surface is not amenable to texture mapping. Parameterization is equivalent to flattening.
Some conventional parameterization methods involve 1) selecting a boundary on a 3-D surface, 2) mapping the boundary to a planar convex polygon, and 3) using relaxation methods to calculate a mapping of interior points of the surface to interior points of the convex polygon. To visualize this process, imagine the 3-D surface to be a rubber sheet whose boundary is stretched around the perimeter of the polygon.
A drawback with these methods is that the planar convex polygon (e.g., a circle or square) does not necessarily reflect the shape of the surface boundary, thus increasing the possibility that the mapping will introduce shape distortions, particularly in polygons close to the boundary. A need therefore exists for an improved system and method for creating a planar boundary which inherits the geometry of a given surface boundary.
SUMMARY OF THE INVENTION
Briefly stated, the present invention is directed to a system and method for generating planar maps which reflect the distances and angles of a 3-D surface, where the user can manually adjust the balance between discontinuity and distortion.
A preferred embodiment of the present invention includes receiving a 3-D surface, defining a surface boundary on the 3-D surface, and generating a planar map based on the 3-D surface and the defined surface boundary. An edge-and-angle proportional mapping is preferably used to map the surface boundary to a map boundary. Those surface vertices not forming the surface boundary are then relaxed to create the map vertices not forming the map boundary.
A feature of the present invention is that a user selectively adjusts the balance between discontinuity and distortion in the planar map.
Another feature is that the present invention allows for the creation of planar maps such that each point on the 3-D surface corresponds to a unique point on the planar map. As a result, operations may be performed on the simpler 2-D planar map rather than the more complex 3-D map, and the result of the operations may be uniquely mapped to the 3-D surface.
Another feature of the present invention is that the majority of the vertices on a 3-D surface are mapped automatically, even though the user maintains a high degree of control over the mapping process via altering the 3-D surface boundary.
Another feature of the present invention is that user-selected map vertices may be pinned to a user-selected location, and held fixed while a conventional relaxation technique is applied. This provides the user with a greater degree of control over the relaxation process.
Another feature of the present invention is that a map boundary interpolation can be performed to generate alternate planar maps. These alternate planar maps may be superior in some respect to non-interpolated planar maps.
Further features and advantages of the invention, as well as the structure and operation of various embodiments of the invention, are described in detail below with reference to the accompanying drawings. In the drawings, like reference numbers generally indicate identical, functionally similar, and/or structurally similar elements. The drawing in which an element first appears is indicated by the leftmost digit(s) in the corresponding reference number.
BRIEF DESCRIPTION OF THE FIGURES
The present invention will be described with reference to the accompanying drawings, wherein:
FIG. 1 is a block diagram of a digital computer environment within which the present invention is used;
FIG. 2 is a flowchart illustrating the functions performed according to the present invention;
FIG. 3A depicts an example 3-D surface;
FIG. 3B depicts an example 3-D surface with a defined boundary;
FIG. 3C depicts an example 3-D surface with a modified (cut) boundary;
FIG. 4A depicts an example planar map of the example 3-D surface with no cuts;
FIG. 4B depicts an example distortionless planar map of the example 3-D surface after cuts;
FIG. 5 is a flowchart detailing the generation of planar maps;
FIG. 6 is a flowchart detailing boundary mapping;
FIG. 7 is a flowchart detailing a preferred embodiment of an edge-and-angle proportional boundary mapping;
FIG. 8A illustrates a first step in a preferred embodiment of an edge-and-angle proportional boundary mapping;
FIG. 8B illustrates a second step in a preferred embodiment of an edge-and-angle proportional boundary mapping;
FIG. 8C illustrates a third step in a preferred embodiment of an edge-and-angle proportional boundary mapping;
FIG. 8D depicts a map boundary generated according to a preferred embodiment of an edge-and-angle proportional boundary mapping;
FIG. 9 is a flowchart detailing relaxation and pinning;
FIG. 10A depicts an example planar map with a distorted map primitive;
FIG. 10B depicts an example planar map after a map vertex has been moved and pinned; and
FIG. 11A depicts an example self-crossing map boundary generated according to a preferred embodiment of an edge-and-angle proportional boundary mapping (source boundary);
FIG. 11B depicts an example map boundary generated according to an edge-proportional boundary mapping (target boundary);
FIG. 11C depicts an example map boundary generated according to an interpolation between a source boundary and a target boundary; and
FIG. 12 is a flowchart detailing the map boundary interpolation method.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Overview of the Environment
FIG. 1 is a block diagram of a digital computer environment 100 within which the present invention is used. A user 102 interacts with a computer system 104 according to conventional user interface techniques. The present invention is preferably implemented as computer readable program code 108 stored on a computer usable medium 110 , accessed via a communication link 112 . Computer system 104 operates under the control of computer readable program code 108 .
Computer system 104 represents any computer system known to those skilled in the art with sufficient capability (i.e., both memory and processing power) to execute computer readable program code 108 . Examples of computer system 104 include, but are not limited to, a microcomputer, workstation, or terminal connected to a central processor.
Computer usable medium 110 is any digital memory capable of storing computer readable program code 108 . Examples of computer usable medium 110 include, but are not limited to, hard disks (both fixed and portable), floppy disks, and CD-ROMs.
Communication link 112 provides the communication pathway between computer system 104 and computer usable medium 110 . Communication link 112 includes, but is not limited to, parallel cables, local area networks, wide area networks, the Internet, and any other combination of electrical equipment designed to pass an electrical signal from one point to another.
User 102 communicates with computer system 104 according to conventional user input/output (I/O) techniques. Computer system 104 (under the control of computer readable program code 108 ) provides output to user 102 according to the present invention via video displays and audio messages, for example. User 102 provides input to computer system 104 via a keyboard, mouse, joystick, voice recognition, or any other type of input device known to those skilled in the art.
The present invention is preferably implemented as computer readable program code 108 . Computer readable program code 108 provides the instructions necessary for computer system 104 to execute the functionality described below. Those skilled in the art will recognize that computer readable program code 108 might be implemented in any computer language (e.g., C) acceptable to computer system 104 .
The present invention is described below in terms of computer graphics displays and operations performed upon these displays. Example graphical displays are provided, along with flowcharts which describe various operations performed on the displays. Those skilled in the art will readily recognize how to implement the graphical displays and operations on those displays as computer readable program code 108 .
Over View of the Invention
The purpose of this section is to provide an overview of the functionality encompassed by the present invention. FIG. 2 is a flowchart 200 describing functions performed by computer system 104 under the control of computer readable program code 108 according to the present invention, and the relative order in which these functions preferably occur. Those skilled in the art will recognize that these steps might equivalently be performed in different sequence, and still achieve the results described below.
In step 202 , computer system 104 receives a 3-D surface. FIG. 3A depicts an example 3-D surface 300 . The functionality of the present invention is described below as operations on 3-D surface 300 —those skilled in the art will recognize how these operations would apply to any arbitrary 3-D surface. Those skilled in the art will also recognize that 3-D surface 300 can be received from any digital memory accessible via communication link 112 , not just computer usable medium 110 .
3-D surface 300 includes one or more surface primitives 302 . A surface primitive 302 is a planar region bounded by surface edges 304 . A surface vertex 306 is the point at which two or more surface edges 304 meet. Consider 3-D surface 300 . Surface vertices 306 are labeled with a single digit number between 1 and 8, and will be referred to, e.g., as surface vertex 1. Surface edges 304 will be referred to herein with reference to the surface vertices 306 each particular edge connects. For example, surface edge 304 connecting surface vertex 2 and 6 will be referred to as surface edge 2-6. Similarly, surface primitives 302 will be referred to with reference to the surface vertices 306 surrounding each particular surface primitive. For example, surface primitive 302 bounded by surface vertices 1, 2, 6, and 5 will be referred to as surface primitive 1-2-6-5 (shown in FIG. 3A as the shaded region). 3-D surface 300 is an “open-topped” box-surface vertices 1 and 3 are not connected, and surface primitives 1-2-3 and 1-3-4 do not exist. 3-D surface 300 therefore includes five surface primitives 302 , eight surface vertices 306 , and twelve surface edges 304 .
Returning to FIG. 2, in step 204 , a surface boundary is defined on 3-D surface 300 . The surface boundary is used by the present invention to generate a planar map from 3-D surface 300 , as is described in detail below. A surface boundary is a closed path along 3-D surface 300 composed of surface edges 304 and surface vertices 306 . In FIG. 3B, four surface edges (4-1, 1-2, 2-3, and 3-4) and four surface vertices (1, 2, 3, and 4) form surface boundary 308 , which will be referred to herein as surface boundary 1-2-3-4.
In step 206 , a planar map is generated based on the 3-D surface received in step 202 , given the surface boundary defined in step 204 . FIG. 4A depicts an example planar map 400 . As with 3-D surfaces, planar map 400 includes map primitives 402 , map edges 404 , map vertices 406 , and a map boundary 408 made up of four map edges (1-2, 2-3, 3-4, and 4-1) and four map vertices (1, 2, 3, and 4). However, planar map 400 is defined in two dimensions (i.e., planar map 400 is defined in a single plane) whereas 3-D surface 300 is defined in three dimensions. The same naming conventions described above with respect to 3-D surface 300 will be followed with respect to planar map 400 .
Planar map 400 must satisfy the following restrictions: each point on 3-D surface 300 must map to a unique point on planar map 400 , and the connectivity of 3-D surface must be maintained in planar map 400 . The uniqueness restriction ensures that each element (i.e., vertex, edge, and primitive) of the 3-D surface corresponds in a one-to-one fashion with one element of the planar map. Map vertices 406 correspond in one-to-one fashion with surface vertices 306 , map edges 404 correspond to surface edges 304 , and so on. For example, map vertex 2 corresponds to surface vertex 2, map edge 2-1 corresponds to surface edge 2-1, map primitive 1-2-6-5 corresponds to surface primitive 1-2-6-5 (both are represented as shaded regions), and map boundary 1-2-3-4 corresponds to surface boundary 1-2-3-4. In order to satisfy this restriction, none of the map primitives 402 may overlap, otherwise the point of overlap would correspond to multiple locations on 3-D surface 300 . However, it is not required that shapes or sizes be maintained, i.e., a map edge may be longer or shorter than the corresponding surface edge and a map primitive may be of a different shape and size than the corresponding surface primitive.
It is this one-to-one correspondence that makes planar map 400 a useful representation of 3-D surface 300 . Consider an embodiment where planar map 400 represents a region of a texture map for a 3-D graphical surface in a computer graphics system. When planar map 400 satisfies the above restriction, the texture region within map primitive 402 will appear only on the corresponding surface primitive 302 , though the texture may be distorted due to any differences in shape between the primitives. Those skilled in the art will recognize additional advantages of ensuring this unique one-to-one correspondence between the 3-D surface and the planar map.
In addition to requiring one-to-one correspondence, planar map 400 must also maintain the connectivity of 3-D surface 300 . That is, map edges 404 and map vertices 406 must be interconnected in the same way that the corresponding surface edges 304 and surface vertices 306 are interconnected. For example, in FIG. 3B, surface vertex 4 is connected (via a single surface edge) to surface vertices 1, 3, and 8. Map vertex 4 must therefore be connected (via a single map edge) to map vertices 1, 3, and 8, as shown in FIG. 4 A. Again, it is not required that the edges be the same length, nor is it required that the primitives be the same shape.
Returning to FIG. 2, flowchart 200 indicates that program flow proceeds from step 206 back to step 204 . According to the current invention, the surface boundary 308 defined in the first iteration of step 204 can be modified in subsequent iterations. Once surface boundary 308 has been modified, a new planar map is generated in step 206 . This iteration may be repeated as many times as necessary to achieve a desired planar mapping of the received 3-D surface.
The following sections provide detailed descriptions of steps 204 and 206 . Defining the surface boundary is described first, followed by the generation of planar maps.
Defining the Surface Boundary
In step 204 , a surface boundary is defined on the 3-D surface. The 3-D surface received in step 202 may have a pre-defined surface boundary, depending on the particular application. Thus, on a first iteration through the method illustrated in flowchart 200 , the surface boundary may need to be defined in its entirety (if the 3-D surface has no pre-defined boundary), or user 102 may wish to modify the pre-defined surface boundary if one is present. On subsequent iterations, in step 204 user 102 may modify the surface boundary defined in the previous iteration. Thus, step 204 encompasses specifying surface boundary 308 in its entirety and/or modifying an existing surface boundary 308 .
Where a surface boundary must be specified in its entirety, user 102 preferably traces the desired surface boundary 308 directly onto the displayed image of 3-D surface 300 using a mouse, trackball, joystick, or any other appropriate user input device. Those skilled in the art will recognize that standard graphical user interface (GUI) techniques might be employed to implement this tracing function. However, those skilled in the art will also recognize that methods other than manual definition could be used for defining surface boundary 308 , such as an automated method which defines surface boundary 308 based on some arbitrary criteria.
Once surface boundary 308 has been defined, user 102 thereafter preferably modifies surface boundary 308 using “cutting” and “sewing” operations. Cutting 3-D surface 300 refers to splitting a surface edge adjacent to surface boundary 308 , such that the modified surface boundary 308 now traces through the split edge. For example, FIG. 3C depicts 3-D surface 300 with a surface boundary 308 modified by a cutting operation. Here, user 102 has cut 3-D surface 300 from surface vertex 4 to surface vertex 8. Cutting operations will be described herein with reference to the surface vertices through which the cut passes. For example, the cut depicted in FIG. 3C would be described as a cut 4-8.
As a result of the cutting operation, an additional surface vertex and surface edge has been created. Surface vertex 4 has been split into surface vertex 4a and 4b, and two surface edges (4a-8 and 4b-8) now exist where there was only one (4-8). The modified boundary on 3-D surface 300 is now indicated by surface boundary 1-2-3-4a-8-4b. FIG. 3C depicts surface vertices 4a and 4b as being spaced apart for illustrative purposes only. Surface vertices generated as the result of a cutting operation actually occupy the same point in 3-D space, as do the split surface edges.
Sewing refers to an operation which is the opposite of cutting, i.e., user 102 may rejoin surface edges and surface vertices which have been split as the result of a cutting operation. Sewing operations will be also described herein with reference to the affected surface vertices.
Cutting a 3-D surface allows, in many instances, a less distorted planar map to be generated. Consider FIGS. 3B and 4A. Planar map 400 is a 2-D mapping of 3-D surface 300 . As can be seen, the shapes of map primitives 402 are distorted as compared to their corresponding surface primitives 302 . This distortion is due to the restrictions placed on planar map 400 (i.e., uniqueness and connectivity). Those skilled in the art will recognize the desirability of producing planar maps where each map primitive accurately reflects the shape of the corresponding surface primitive. For example, map primitive 1-2-6-5 (shown as the shaded map primitive in FIG. 4A) would ideally have the same shape as surface primitive 1-2-6-5 (shown as the shaded primitive in FIG. 3 B). However, as can be seen, these shapes are similar but not identical. The measure of this difference in shape will be referred to as distortion.
Given the restrictions on planar map 400 , it is generally not possible to produce a distortionless planar map of a 3-D surface. Consider 3-D surface 300 . Clearly, it is not possible to “flatten out” this open-topped box to a distortionless planar map while maintaining connectivity and one-to-one correspondence. However, it would be possible if one were to cut the box along certain of the edges. The box could then be unfolded and laid flat, while maintaining connectivity and one-to-one correspondence.
FIG. 4B depicts a distortionless planar map 400 generated according to the present invention where user 102 performed the following cuts to 3-D surface 300 in step 204 : 4-8, 8-7, 8-5, and 5-6. As shown in FIG. 4B, map boundary 1-4b-8c-5b-6-5a-8b-7-8a-4a-3-2 results from this series of cuts. Now, for example, map primitive 4a-3-7-8a and surface primitive 4-3-7-8 have an identical shape, as do the other four primitives. Those skilled in the art will recognize that further cuts will not further decrease the distortion, as planar map 400 is already distortionless. Connectivity is also maintained, as each cut creates an extra surface vertex and surface edge, which may then be separated and laid flat. Thus, cutting operations in some instances will decrease distortion in planar map 400 .
However, distortion is not the only measure of interest. Those skilled in the art will also recognize that the discontinuities introduced by the cuts are not desirable for some applications. In the present context, a discontinuity refers to the situation where the map primitives corresponding to adjoining surface primitives do not adjoin because of a cut. For example, surface primitive 4-3-7-8 adjoins (i.e., shares an edge with) surface primitive 1-4-5-8; however, their corresponding map primitives 4a-3-7-8a and 6-7-8b-5a do not adjoin because of cut 7-8. Planar map 400 has greater discontinuity in FIG. 4B than in FIG. 4A, but less distortion.
This illustrates the fundamental tradeoff between discontinuity and distortion. Cutting 3-D surface 300 increases the discontinuity of planar map 400 but decreases the distortion. Those skilled in the art will recognize that the particular application to which the present invention is applied will determine the appropriate balance between distortion and discontinuity. The iterative approach of the present invention allows user 102 to achieve a desired balance by varying the number of cuts made to 3-D surface 300 .
Generation of Planar Maps
Once 3-D surface 300 has been received, and surface boundary 308 defined, a planar map is then generated in step 206 . FIG. 5 depicts a flowchart 500 illustrating step 206 in greater detail. Planar map generation is fundamentally a two step process: boundary mapping and relaxation. In step 502 , surface boundary 308 (see FIG. 3 B), which is defined in three dimensions, is mapped according to the present invention to 2-D map boundary 408 (see FIG. 4 A). In step 506 , conventional relaxation techniques are then applied to the remainder of the surface vertices (those surface vertices 306 not forming surface boundary 308 ) to form map vertices 406 . These steps are described in detail in the following two sub-sections.
Steps 504 and 508 describe an extension to the basic planar mapping described in steps 502 and 506 , whereby the map boundary created in step 502 is interpolated with another map boundary created according to a conventional boundary mapping technique. This extension is discussed in detail below.
Boundary Mapping
FIG. 6 depicts a flowchart 600 illustrating step 502 (mapping surface boundary 308 to map boundary 408 ) in greater detail. In step 602 , the surface angle is calculated at each surface vertex 306 on surface boundary 308 . For example, referring to FIG. 3B, the surface angle is calculated at surface vertices 1, 2, 3, and 4. The surface angle is calculated at each surface vertex 306 by determining the angle between the two boundary edges which meet at the surface vertex, where the angle is calculated traveling along 3-D surface 300 .
For example, at surface vertex 4, the surface angle is equal to the angle separating surface edges 1-4 and 3-4 traveling along 3-D surface 300 . To calculate the angle traveling along 3-D surface 300 , the angle between surface edges 4-1 and 4-8 must be added to the angle between surface edges 4-8 and 3-4. Each of these angles is 90 degrees, so the surface angle at surface vertex 4 is 180 degrees. Similarly, at surface vertex 1, the surface angle is the total of the angle between surface edges 1-4 and 1-5 (90 degrees), and the angle between surface edges 1-5 and 1-2 (135 degrees, totaling 225 degrees). The surface angle at surface vertex 2 is 90 degrees, and 225 degrees at surface vertex 3.
In step 604 , the length of each surface edge forming surface boundary 308 is calculated. For example, in FIG. 3B, the length of surface edges 1-4, 1-2, 2-3, and 3-4 are calculated.
In step 606 , map boundary 408 is created, where the planar angle at each map vertex 406 along map boundary 408 is proportional to the surface angle at the corresponding surface vertex 306 . Similarly, the length of each map edge along map boundary 408 is proportional to the length of the corresponding surface edge along surface boundary 308 . Step 606 is therefore called an “edge-and-angle proportional” mapping.
The term “proportional” as used herein indicates approximate proportionality by a factor common to all the planar/surface angle relationships, k a , and a factor common to all the map/surface edge relationships, k e . For example, the planar angle at map vertex 4 is approximately equal to k a times the surface angle at surface vertex 4, the planar angle at map vertex 1 is approximately equal to k a times the surface angle at surface vertex 1, and so on for the remainder of the corresponding planar/surface angle relationships along map boundary 408 . Similarly, the length of map edge 3-4 is approximately equal to k e times the length of surface edge 3-4, the length of map edge 4-1 is approximately equal to k e times the length of surface edge 4-1, and so on for the remainder of the corresponding map/surface edge relationships along map boundary 408 .
Those skilled in the art will recognize that various approaches might be followed for calculating planar angles and map edge lengths which are proportional to surface angles and surface edge lengths. FIG. 7 depicts a flowchart 700 which illustrates a preferred edge-and-angle proportional mapping method. Reference will also be made to FIGS. 8A-8D which graphically illustrate these operations on surface boundary 308 as defined in FIG. 3 B. Note that these illustrations are meant for explanatory purposes only—in a preferred embodiment, the calculations take place within computer system 104 and only the final result (FIG. 8D) is displayed to user 102 .
In step 702 , the planar angles of map boundary 408 are set equal to the corresponding surface angles calculated in step 602 , and the map edge lengths of map boundary 408 are set equal to the corresponding edge lengths calculated in step 604 . FIG. 8A depicts map boundary 408 at this stage of the edge-and-angle proportional mapping. The planar angle at each map vertex 406 is the angle between the two map edges 404 which meet at the map vertex in the plane in which map boundary 408 is defined. For example, map vertex 3 has a planar angle 802 as shown in FIG. 8 A. Planar angle 802 is set equal to the surface angle calculated at surface vertex 3, i.e., 225 degrees. Planar angle 808 indicates the angle between map edges 1-2 and 2-3—the dashed line indicates the angular position of map edge 2-3 relative to map edge 1-2—which is set equal to the surface angle calculated at surface vertex 2, i.e., 90 degrees.
In step 704 , the planar angles of map boundary 408 are adjusted in prorata fashion so that their sum is π(n−2), where n is the number of map edges forming map boundary 408 . The appropriate angle proportionality factor, k a , for achieving this angle sum is computed according to the following equation: k a = π ( n - 2 ) α tot
where α tot =sum of planar angles on map boundary The planar angle at each map vertex along map boundary 408 is multiplied by k a ; proportionality, as described above, is therefore maintained. FIG. 8B depicts map boundary 408 after planar angles 802 , 804 , 806 , and 808 have been adjusted. Note that at this step in the mapping, the map edge lengths along map boundary 408 are equal to the corresponding surface edge lengths, and are therefore proportional (i.e., k e =1).
In FIG. 8B, note that map boundary 408 remains open. As noted above, one constraint on boundaries, both surface and map, is that they be closed. Therefore, in step 706 , map vertices 406 are appropriately displaced so as to close map boundary 408 . According to the present invention, map vertices 406 are displaced in a computationally efficient manner while maintaining edge and angle proportionality.
In a preferred embodiment, each map vertex 406 is displaced in the same direction, by an amount determined by the position of the vertex on map boundary 408 . Referring to FIG. 8C, map boundary 408 is shown as being open at map vertex 2 (shown between map edges 3-2 and 1-2, though by definition map vertex 2 only exists at the intersection of these two map edges). Map boundary 408 is closed by displacing the end of map edge 3-2 (at map vertex 2) according to a displacement vector 810 . The magnitude and direction of displacement vector 810 are equal to the magnitude and direction of the displacement necessary to close map boundary 408 . As shown in FIG. 8D, map vertex 2 is now properly displayed at the juncture of map edges 3-2 and 1-2.
The remainder of the map vertices on map boundary 408 are also displaced. In a preferred embodiment, each displacement vector is calculated according to the following formula: D _ i = ( L i L tot ) D _ where D _ i displacement vector at i th map vertex D _ displacement vector at map boundary opening L i length of map boundary at i th map vertex L tot total length of map boundary
Referring to FIG. 8C, {overscore (D)} is illustrated as displacement vector 810 (the displacement necessary to close map boundary 408 ), {overscore (D)} 1 is illustrated as displacement vector 816 , {overscore (D)} 4 is illustrated as displacement vector 814 , and {overscore (D)} 3 is illustrated as displacement vector 812 .
The remaining map vertices (3, 4, and 1) are displaced according to displacement vectors given by the above formula. L tot is the total length of map boundary 408 (i.e., sum of the length of map edges 1-2, 1-4, 4-3, and 3-2). L i is the length along map boundary 408 where map vertex i (i.e., the map vertex for which a displacement vector is being calculated) is positioned. For example, at map vertex 3, L 3 is equal to the sum of the length of map edges 1-2, 1-4, and 4-3. This sum is divided by the total length of map boundary 408 and multiplied by {overscore (D)} to determine {overscore (D)} 3 (displacement vector 812 ). At map vertex 4, L 4 is equal to the sum of the length of map edges 1-2 and 1-4. This sum is divided by the total length of map boundary 408 and multiplied by {overscore (D)} to determine {overscore (D)} 4 (displacement vector 814 ).
FIG. 8D depicts map boundary 408 after the map vertices have been displaced according to displacement vectors 810 , 812 , 814 , and 816 , as shown in FIG. 8 C. As required, map boundary 408 is now closed. Those skilled in the art will recognize that many different approaches might be taken to close map boundary 408 , and still achieve the same effect of maintaining edge and angle proportionality while minimizing computational costs. This closing of map boundary 408 completes step 706 in FIG. 7, step 606 in FIG. 6, and step 502 in FIG. 5 .
Those skilled in the art will also recognize that alternative approaches exist for creating an edge-and-angle proportional boundary in step 606 . One alternative approach is to simulate a system of rods whose lengths are proportional to the surface edge lengths. Each adjacent pair of rods is connected with an angular spring whose rest angle is the surface angle, and which delivers a force proportional to the departure from that angle. The simulated system is allowed to relax while constrained to a plane. The resulting configuration of rods is the map boundary.
Relaxation & Pinning
Returning to FIG. 5, now that surface boundary 308 has been mapped to map boundary 408 , in step 506 a conventional relaxation technique is applied to the remainder of the surface vertices 306 , i.e., those surface vertices 306 not on surface boundary 308 . Relaxation techniques are well known to those skilled in the art, such as the techniques described in Matthias Eck et al., “Multiresolution Analysis of Arbitrary Meshes,” Computer Graphics (SIGGRAPH '95 Proceedings), 1995, pp. 175-76 (ACM-0-89791-701-4/95/008), which is incorporated herein by reference. Relaxation may be analogized to a configuration of springs with one spring placed along each surface edge 304 not on surface boundary 308 . Surface boundary 308 is treated like a rigid framework within which surface vertices 306 are then allowed to relax, forming map vertices 406 in their rest position (i.e., the position of minimum energy).
Referring to example 3-D surface 300 in FIG. 3B, and example planar map 400 in FIG. 4A, a conventional relaxation technique is applied to surface vertices 5, 6, 7, and 8 to form the corresponding map vertices 5, 6, 7, and 8. FIG. 4A depicts a likely result of applying a conventional relaxation technique to surface vertices 5, 6, 7, and 8.
FIG. 9 is a flowchart 900 which illustrates step 506 in further detail. Once surface boundary 308 has been mapped to map boundary 408 in step 502 , a relaxation technique is applied to those surface vertices not on the surface boundary in step 902 (as described above), forming those map vertices 406 not on map boundary 408 .
According to a preferred embodiment, in step 904 user 102 has the option of performing a “pinning” operation. If user 102 desires to perform a pinning operation, program flow continues to step 906 . Otherwise, program flow returns to step 204 in FIG. 2, where user 102 is once again able to define surface boundary 308 .
In step 906 , user 102 selects one or more map vertices and pins them to a particular location(s). Pinning refers to modifying the position (in the 2-D plane in which the planar map is defined) of the selected map vertices 406 and fixing the new position so that when the relaxation technique is again applied in step 902 , the “pinned” map vertices are held in place. As a result, those map vertices which are pinned, like those which are on map boundary 408 , are treated like a rigid framework and the remainder of the map vertices are allowed to relax.
FIG. 10A depicts an example planar map 1000 which will be used to illustrate the pinning operation. For purposes of this example, assume that a surface boundary (not shown) defined on a 3-D surface (not shown) was mapped to map boundary 408 (as shown in FIG. 10A) in step 502 . Assume further that a relaxation technique was applied in step 902 to those surface vertices not on the surface boundary, forming map vertices 5, 6, 7, and 8. Those skilled in the art will recognize that, for many purposes, map primitive 1-5-8-4 might be of little use given its small size. For example, assume that planar map 1000 represents a texture map in a computer graphics system, and that map primitive 1-5-8-4 is too small to be useful and is a distorted representation of the corresponding surface primitive 1-5-8-4 (not shown). User 102 may manually correct for these problems using pinning.
According to a preferred embodiment, user 102 uses a pointing device (e.g., mouse, joystick, trackball) available with computer system 104 to “drag” map vertex 8 to a new position, such that the redefined map primitive 1-5-8-4 is less distorted and has an increased area. As shown in FIG. 10B, user 102 has dragged map vertex 8 to a new position. Now, map primitive 1-5-8-4 has a larger area and, presumably, is more representative of surface primitive 1-5-8-4 (i.e., less distortion).
Map vertex 8 has now been pinned to the new location shown in FIG. 10 B. When program flow again returns to step 902 (after all pinning is complete), a relaxation technique is applied to map vertices 5, 6, and 7, which will likely relax to a new configuration (depending on the particular configuration and relaxation technique used). Map vertices 1,2,3, and 4 are held rigid because they are on map boundary 408 , and map vertex 8 is held rigid because it has been pinned.
Program flow continues back to step 904 , where user 102 again has the option to perform additional pinning. In this manner, user 102 may continue altering planar map 1000 until a desired result is achieved. Those skilled in the art will recognize the advantages of this approach, particularly given extremely complex planar maps with thousands of map vertices. Often, it is desirable to iteratively modify these complex planar maps by pinning key map vertices and relaxing the rest, until each map primitive has an acceptable shape and size.
Map Boundary Interpolation
The edge-and-angle proportional mapping method described above can generate planar maps having undesirable qualities. For example, the aforementioned methods can generate a map boundary which crosses itself (“self-crossing” boundary). Self-crossing map boundaries are undesirable because it is no longer true that all points on a 3-D surface map to a unique point on the planar map-the self-crossing map boundary creates an overlap region where a single point on the planar map corresponds to two or more points on the 3-D surface. Another example of an undesirable planar map is one that contains areas which are unacceptably distorted. Those skilled in the art will recognize other instances where the aforementioned methods produce undesirable planar maps.
Returning to FIG. 5, steps 504 and 508 describe an extension to the mapping methods described above whereby the map boundary generated in step 502 is interpolated with a different map boundary generated according to a conventional boundary mapping technique. This interpolation can alleviate some of the undesirable effects mentioned above.
Alternatively, the interpolation described in steps 504 and 508 can be used even where the aforementioned methods generated an acceptable planar map to provide an alternate, possibly superior in some respect(s), planar map.
For purposes of illustration, assume that step 502 has created a self-crossing map boundary, as depicted in FIG. 11A, based on a 3-D surface (not shown) with a defined surface boundary. Map edge 1s-2s crosses map edge 5s-6s and map edge 2s-3s crosses map edge 4s-5s. This map boundary will be referred to as the source map boundary 1102 .
In step 504 , program flow continues on to step 508 where interpolation is to be performed, or to step 506 where the interpolation is not to be performed. In a preferred embodiment, user 102 determines whether or not map boundary interpolation will be performed. Those skilled in the art will recognize that this determination could also be made automatically. For example, in an alternate embodiment interpolation is automatically performed whenever a self-crossing boundary is detected (according to conventional numerical techniques).
In those instances where map boundary interpolation is to be performed, program flow proceeds to step 508 . FIG. 12 is a flowchart illustrating step 508 in greater detail. In step 1202 , another planar map is generated according to a conventional boundary mapping method.
Any conventional boundary mapping method may be used in step 1202 . For example, an edge proportional boundary mapping method can be used. Edge proportional methods map the surfaces vertices on the surface boundary to the perimeter of a pre-selected geometric shape in proportion to the length of the surface edges forming the surface boundary. Edge proportional methods produce map boundaries which are convex, a property which is particularly useful, for example, when the interpolation is used to correct for a self-crossing map boundary generated in step 502 , as will be described below. Convex boundaries, by definition, do not self-cross.
For purposes of illustration, assume that an edge proportional method is used in step 1202 . FIG. 11B depicts an example map boundary generated by applying an edge proportional method to the same 3-D surface used to generate source map boundary 1102 . In a preferred embodiment, the pre-selected geometric shape is a rectangle 1112 , though other shapes may be used. All of the surface vertices on the surface boundary are mapped onto rectangle 1112 . The distance between them, measured along the rectangle perimeter, is proportional to the length of the surface edge connecting the vertices-the resulting map boundary is therefore “edge proportional.”
These distances are calculated by multiplying the total length of the rectangle perimeter by the length of the surface edge, and dividing that product by the total length of the surface boundary. Once map vertices 1108 are placed, they are connected to form map edges 1110 . For example, in FIG. 11B map vertices 1108 are first placed along rectangle 1112 , where the distances between map vertices 1108 are calculated as described above. Once map vertices 1108 are placed, map edges 1110 are created in “connect-the-dots” fashion. This map boundary will be referred to as the target map boundary 1104 .
In step 1204 , source map boundary 1102 and target map boundary 1104 are interpolated to form a new map boundary. According to a preferred embodiment, the interpolation is computed as follows:
new — angle i =source — angle i (1−α)+ target — angle i *α
new — length i =source — length i (1−α)+ target — length i *α
The interpolation parameter α controls the relative weight accorded source map boundary 1102 and target map boundary 1104 . The source and target map boundaries have the same number of map vertices (and map edges) because they were generated using the 3-D surface and surface boundary. Referring to FIGS. 11A and 11B, source map boundary 1102 has six map vertices 1s to 6s and target map boundary 1104 map vertices 1t to 6t(“s” and “t” designate source and target).
FIG. 11C depicts an interpolated map boundary 1110 , which is interpolation of source map boundary 1102 and target map boundary 1104 according to the formula above. The planar angle at each map vertex on the interpolated map boundary is equal to the weighted average of the planar angles at the corresponding map vertices on the source and target map boundaries, where the relative weighting is determined by interpolation parameter α. For example, the planar angle at map vertex in (new_angle 1 ) is calculated by multiplying (1−α) times the planar angle at map vertex Is (source_angle 1 ) and adding a times the planar angle at map vertex It (target_angle 1 ). Similarly, the length of map edge 1n-2n (new_length 1 ) is calculated by multiplying (1−α) times the length of map edge 1s-2s (source length 1 ) and adding a times the length of map edge 1t-2t (target_length 1 ).
As shown in FIG. 11C, interpolated map boundary 1106 is no longer a self-crossing boundary. However, this result is not guaranteed in every case, depending on the particular boundaries involved and the value chosen for the interpolation parameter α. If α is chosen such that the source map boundary is too heavily weighted (small α), the resulting interpolated map boundary may still be self-crossing. A non-self-crossing map boundary can eventually be achieved by increasing the value of α, thereby increasing the weight given to the target map boundary.
The interpolation parameter α is preferably selected by user 102 . However, those skilled in the art will recognize that a could be pre-set (ie., 0.5, which accords equal weight to the source and target map boundaries) or chosen automatically based on any one of a variety of criteria.
This preferred interpolation is easy to implement and requires very little processing time. However, those skilled in the art will recognize that more sophisticated interpolations could be used at the cost of additional complexity and processing time. The fundamental idea remains the same: interpolating a source map boundary generated by an edge-and-angle proportional method with a target map boundary generated by any other conventional method.
Referring to FIG. 11C, interpolated map boundary 1110 is not closed at map vertex 6n. The preferred interpolation described above does not guarantee that the interpolated map boundary will be closed-in general the interpolated map boundary will not be closed. Therefore, in step 1206 the interpolated map boundary is closed by displacing the map vertices in the same manner as described above with respect to step 706 in FIG. 7 .
Conclusion
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. 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 and their equivalents.
The previous description of the preferred embodiments is provided to enable any person skilled in the art to make or use the present invention. While the invention has been particularly shown and described with reference 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.
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Planar texture maps which reflect the distances and angles of a 3-D surface are generated. A user is permitted to manually adjust the balance between discontinuity and distortion. The user selectively modifies the 3-D surface, and by doing so adjusts the balance between discontinuity and distortion in the planar map. Each point on the 3-D surface corresponds to a unique point on the planar map. Operations may therefore be performed on the simpler 2-D planar map rather than the more complex 3-D map, and the result of the operations may be uniquely mapped to the 3-D surface. Further, the majority of the vertices on a 3-D surface are mapped automatically, even though the user maintains a high degree of control over the mapping process via altering the 3-D surface boundary. User-selected map vertices may be pinned to a user-selected location, and held fixed while a conventional relaxation technique is applied. This provides the user with a greater degree of control over the relaxation process.
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CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of U.S. patent application Ser. No. 541,773 filed on Jun. 21, 1990, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the field of medical devices. In particular, the present invention related to power supply systems for transcutaneous energy transfer (TET) devices. Even more particularly, the present invention relates to an improvement in TET devices which simplifies such devices and improves their energy transfer efficiency.
2. Description of the Related Art
A TET device is a device for providing electrical power to an implanted mechanical or electrical medical device, such as prosthetic hearts and ventricular assist devices, without having to breach the skin to lead conducting wires therethrough.
An example of a TET device is shown in U.S. Pat. No. 4,665,896 (LaForge et al) dated May 19, 1987. That patent shows a blood pump system powered by a TET device having an external primary winding and an implanted secondary winding. It is designed to be regulated to a precise degree, the power delivered to an implanted medical device. However, it is not concerned with power transfer efficiency across the skin.
U.S. Pat. No. 4,408,607 (Maurer) dated Oct. 11, 1983, on the other hand, describes a TET device which charges an implanted capacitor. Power is then drawn by a implanted medical device from the capacitor. Maurer does not require particularly efficient TET efficiency, it will be understood, because it utilizes TET technology to provide an induced voltage to charge a capacitor. An efficient capacitor is, under Maurer's proposal, much more crucial than efficient TET. Moreover, the Maurer patent relates to very small power levels-on the order of those obtainable with a fairly small implanted capacitor. With Maurer's parallel tuned circuit, Q will fall at high loads levels.
In U.S. Pat. No. 4,741,339 of May 3, 1988, Harrison et al describe a TET with improved coupling between internal and external inductive coils. The means for achieving such improved coupling proposed by Harrison includes a circuit electrically coupled to the primary coil, tuned to increase the quality factor of the primary transmitter circuit which includes the primary coil. Harrison, as well is concerned with very low power levels, and accordingly, does not have application to a system designed to provide a power source for an artificial heart.
BRIEF DESCRIPTION OF THE DRAWINGS
The object of the present invention is to provide a simple means of increasing power transmission efficiency levels in a TET device to over 80%--higher than in previous TET devices. The present invention accomplishes this result without the need for complex and expensive additional circuitry.
In one broad aspect, the present invention relates to an improved transcutaneous energy transfer (TET) device comprising: (i) a primary winding for placement at a skin surface, said primary winding being electrically connectable to an external DC power source; (ii) a secondary winding for implantation under said skin surface, coupled with said primary winding to define a transcutaneous transformer; (iii) a field effect transistor (FET) arranged in series with said primary winding to switch said primary winding across said external DC power supply for a predetermined period of time; and (iv) a tuning capacitor linked to said primary winding parallel to said FET whereby said primary winding, when said FET is turned off after said predetermined period, will resonate at its natural frequency obviating the effect of component drift in values of other electronic components of the TET device.
In another broad aspect, the present invention relates to a bidirectional communications link for the transfer of data across a boundary layer by means of infrared (IR) signal transmission and reception, said link including at least one IR transmitter on one side of boundary layer, and at least one IR receiver on the other side of said boundary layer, the improvement that comprises providing at lesat three said transmitters on one side of said boundary layer, arranged in a circular pattern, opposite said receiver on the other side of said boundary layer, said receiver being substantially at the centre of said circular pattern.
In drawings which illustrate the present invention by way of example:
FIG. 1A is a schematic of the transcutaneous energy transfer (TET) device of the present invention;
FIG. 1B is a waveform diagram comparing the voltage controlled oscillator waveform (WA) and the TET transformer excitation waveform (WB);
FIG. 2 is a detail in schematic form of the circuit of the implanted portion of the TET device shown in FIG. 1;
FIG. 3 is a cross sectional schematic of the configuration of the primary and secondary coils according to the present invention;
FIG. 4 is a schematic representation of the arrangement of infrared (IR) components in the internal and external modules;
FIG. 5 is a graph plotting received IR signal against the distance between the transmitter and the receiver; and
FIG. 6 is a simplified block diagram of the IR telemetry system employed in the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIGS. 1 and 2, it will first be appreciated that the present invention is a transformer designed to induce A.C. current in a subcutaneous winding, for transformation to DC to power of a medical device. AC current is induced in L2, the secondary winding which may be, for instance, a torus core, wound with Litzendraht (Litz) wire implanted just under the skin S with electrical leads connected to a medical device requiring electrical power. A similar primary winding L1 is located in alignment with the secondary winding, on the skin surface.
Primary winding L1 is connected to a capacitor 11 that is connected to the negative of a DC input bus. Winding L1 is also connected to a field effect transistor (FET) 10, as indicated in FIG. 1A. FET 10 is controlled by FET driver 20, said shown in FIG. 1A. Driver 20 receives inputs from voltage controlled oscillator 21, soft start control 22 and low voltage shutdown 23, also as shown in FIG. 1A, to produce waveform WA shown in FIGS. 1A and 1B.
Power transfer may be considered to take place in two phases, a storage phase and a resonant phase. During the storage phase, energy is stored in the primary coil using a field effect transistor (FET) to switch the coil directly across the DC input supply. The FET is selected for its very low "on" resistance to minimize the conduction losses.
In FIGS. 1A and 1B, the FET 10 is driven by a waveform WA which is generated by the voltage controlled oscillator. The period T1 represents the time when the FET 10 is turned on (on time). During this time the primary coil L1 is connected directly across the DC input power bus causing the current in L1 to rise as a linear function of time. At the end of T1 (beginning of T2) the FET 10 is turned off allowing L1 to resonate with capacitor 11. The period T2 is adjusted so that L1 when resonating with capacitor 11 is allowed to complete one half cycle of oscillation plus about 10 percent of its cycle time, i.e. T2 is approximately Tp/2+Tp/10 as shown in FIG. 1B, as the short gap following Tp/2. The diode D1 prevents the waveform WB from going negative during the time period T2-Tp/2, as illustrated in FIG. 1B.
The peak voltage Vp across the primary coil L1 is determined by the peak current attained at the end of T1, and the impedance of L1 at the circuit resonant frequency. T1 and T2 do not have a fixed relationship, their ratio will depend upon the required Vp to achieve the desired voltage transfer ratio from DC in to DC out. The primary coil L1 is turned to a frequency slightly greater than 2/T2. Some variation in the turned frequency can be tolerated providing Tp/2≦T2 and Tp/2>(2.T2)/3. This latter condition is somewhat load dependant but typically variations in the resonant frequency of the primary of ±10% can be tolerated. Because the TET transformer has a low coupling coefficient (<0.5) it is possible to tune the primary and secondary coils to quite different frequencies. As previously stated the primary coil is allowed to resonate at its natural frequency (as tuned by C11) while the secondary coil is turned to the VCO frequency 1/T3 where T3=T1+T2. Waveform WB (FIG. 1B) represents the TET transformer excitation waveform which is non sinusoidal and consequently harmonic rich. The secondary coil is tuned to the fundamental and will reject harmonics according to the Q factor of the secondary circuit. The secondary coil is series tuned by capacitor 13 (see FIG. 2) thus the Q factor of the secondary circuit is dependant on the load resistance. When the load resistance is high (lightly loaded) the Q is low and so harmonic rejection will be less effective. Consequently increased levels of harmonic voltages will appear across the load resistance and contribute to the DC load voltage. This is undesirable since the output DC voltage will have a strong dependence on load conditions. In order to significantly reduce this effect C14 was introduced to stabilise the Q against load variations. The load is now considered as being composed of C14 in parallel with the actual load resistance. Under no load conditions C14 comprises the entire load maintaining an acceptable Q and preventing excessive voltages reaching the DC output. Thus C14 acts as a Q stabiliser. A low loss silver-mica capacitor has been employed to minimise 1 2 R losses and maintain a high power transfer efficiency at all power levels from 5 to 50 watts delivered power. The implanted portion of the TET of the present invention, including the secondary coil has a duty cycle of about 0.75, and the resonant frequency of the secondary coil is lower than that of the external portion, including the primary coil L1. This arrangement results in what shall hereinafter be referred to as "dual resonance".
The resonant phase is terminated when the voltage across the FET reaches zero. At this point, the FET is again turned on to begin a new energy storage phase. Since the FET is only turned on close to a zero voltage crossing, switching losses in the FET are minimized. This enables the TET operating frequency to be increased over previous designs. Operating at higher frequencies permits smaller capacitors to be used for energy storage and smaller magnetic components for the transformer.
In addition, the use of a single ended quasi-resonant drive for the primary coil enables this circuit to tolerate variations in the transformer coupling due to coil separation. In previous designs, the primary transformer current increased as coupling was reduced, theoretically approaching infinity as the coupling reached zero. Thus it was necessary to include special circuitry to turn off the primary coil driver under such conditions. This additional circuitry is not required in the present design since a constant maximum stored energy operating mode is employed.
This mode of operation also allows the TET to tolerate induction losses due to adjacent conducting masses. In previous designs, the TET would shut down under such conditions, ceasing power transfer. The present design copes with this situation by reducing power transfer efficiency, shutting down only in extreme situations.
The use of the Litz wire contributes to the overall efficiency of the TET, which is over 80% for a wide range of load conditions. The Litz wire is composed of many individually insulated strands which are bunched in a particular way to reduce eddy current losses. There are five bunches of five bunches of three bunches of 23 strands in the Litz wire giving a total of (5×5×3×23=) 1,725 strands. The increased surface area of the Litz wire contributes to the reduction in the losses in the coils.
As can be seen in FIG. 2, the AC current is induced in secondary winding L2 which resonates with capacitor 12. The AC is converted to DC by means of a simple circuit including a complimentary resonant capacitor 14 to further enhance the transmission efficiency of the TET systems. The secondary tuned circuit is series turned with 13 to the fundamental. As a consequence of series tuning the Q of this circuit will be dependent on the loading conditions. The load resistance can be viewed as the loss element in the tuned circuit. Because the excitation waveform is non-sinusoidal it contains harmonics which will alter the effective voltage transfer ratio of the TET device (DC to DC) as the Q of the secondary circuit changes with load. The second capacitor in the secondary tuned circuit provides a reactive load to the secondary coil under light or no load conditions. Its effect is to maintain a sufficiently high Q in the secondary circuit (which would be zero under no load conditions) to reject harmonics in the power waveform. This feature stabilises the DC output on the secondary side which would become excessive under light or no load conditions.
The inclusion of this load sensitive tuning tends to stabilize the voltage transfer ratio of the TET against load variations. This is achieved by modifying the resonant frequency of the secondary circuit as the load varies. This improves load regulation, and permits operation of the secondary circuit without complex feedback regulation.
Turning to FIG. 3, the configuration of the primary and secondary coils is illustrated. It will be understood in previous TET designs, the implanted secondary coil is substantially encircled by the torus-like primary coil which sits on the skin surface. This arrangement permits fairly accurate emplacement of the primary coil over the secondary, and means that there is very little change in coupling co-efficient if the primary and secondary coils are moved slightly, as can easily happen in normal use. The problem with this type of arrangement is that it is very sensitive to inductive influences, and the proximity of a large metal object will result in a complete shutdown of energy transfer.
The present invention however, provides a coil configuration that is relatively insensitive (about 12% power loss) to the presence of metallic objects. As can be seen from FIG. 3, the present transformer employs a primary coil having a shallow bell shaped profile which covers the secondary coil. This results in a design which is relatively insensitive to inductive interference by adjacent conducting objects. The present method of electronic power transfer is also more tolerant to inductive interference and thus the overall TET system enables the energy transfer to tolerate close contact with a metallic surface. When a large metallic plate is brought into close contact with the TET primary coil, (limited only by the insulation thickness of said primary) energy transfer efficiency falls by only about 12%. A similar situation applied to the prior systems would result in a complete shutdown of energy transfer.
The dome shaped construction of the secondary coil L2 (see FIGS. 1A, 2 and 3) assists in coupling stabilisation and also mechanical alignment of the primary coil L1 (see FIGS. 1A and 3). The internal space that this affords is utilised to house the internal AC-DC converter 13, which results in a number of significant advantages: (1) Power dissipation in the AC-DC converter is better distributed by the large copper mass of the secondary coil. (2) This power no longer contributes to the increased temperature of the internal electronic controller. (3) High frequency, high voltage AC induced in the secondary coil and transmitted directly to the AC/DC converter is kept within the secondary coil, physically isolated from sensitive electronics that may also be implanted. (4) The interconnecting wires from the AC-DC converter corrected to the secondary coil (see FIG. 1A) to the electronics and pump module of an implanted artificial heart (not illustrated) carry DC and are not part of the tuned secondary circuit. This reduces the effect on the resistance of the DC circuit and thereby increases the efficiency of the effective tuned secondary coil circuit and enables conventional smaller gauge stranded wire (not Litz) to be used to carry the DC from the coil to the electronics.
In a typical embodiment, the primary coil will be about 90 mm in diameter, with a depth of 23 mm, and the secondary coil will be 66 mm in diameter, with a depth of 24 mm.
The mechanical design of the power transfer coils allows the placement of an infrared data communications module in the top centre of each coil (see FIG. 3). The infrared components for the internal module are mounted on small circular circuit card coaxially positioned within the internal power coil. The external IR components are similarly mounted within the primary coil.
Since a bidirectional communication link across the skin was required, the best arrangement of transmitter and receiver was investigated. FIG. 4 shows the chosen arrangement of IR components on each circular card.
Each photo-receiver is placed coaxially within a triad of diode emitters. The emission centres of the three transmitters are placed with a 120° separation on a 5 mm diameter circle centred on the receiver active point. This arrangement provides a symmetrical radiation pattern around the receiver and increases the tolerance of the IR link to coil misalignment by enlarging the radiation pattern. The diode transmitters are connected in series resulting in virtually no increase in the power demand from the supply. A further advantage of this arrangement is evident in the transmission loss versus transmitter-receiver separation. FIG. 5 shows the stabilisation effect on the IR transmission curve as the emitters and receiver are separated in air. For separations less than 5 mm the receiver is lying between the opposing transmitters, receiving IR at an oblique angle. As the separation increases a minimum is reached at about 5 mm. The location of this minimum is related to the radiant intensity pattern of the chosen transmitters. Beyond this the received signal rises as the intensity distributions of the three transmitter diodes merge. A peak in the received signal occurs at about 15 mm and then decays as the transmitter diodes begin to appear as a single point source. The thickness of the covering skin is expected to lie in the range of 5 mm to 15 mm.
The system operates at 9600 band in full duplex with an overall character error count of <10 -6 . The mean current drive to the diodes is approximately 20 mA. The system is insensitive to noise from transient currents of 3 Amperes flowing in the adjacent power transfer coils. An IR transmitter-receiver axial separation of up to 150 mm can be tolerated in air without a significant increase in data errors. This is sufficient for transmission through a skin layer of 5 mm to 15 mm. Porcine skin was found to have an effective attenuation of 6-10 dB in comparison to the same separation in air. Fresh cadaver skin was found to have an attenuation in the range 6-20 dB for skin thickness of 5-15 mm.
A simplified block diagram of the full duplex FSK system is illustrated in FIG. 6. Each half of the system is composed of a single chip modulator, a single chip demodulator and a single chip active filter. Binary data from the internal processor is frequency shift keyed between 20 kHz and 30 kHz using the XR2206 modulator manufactured by EXAR. This part was chosen because it is able to produce a low distortion sine wave output and requires a minimum of external components. The output of this chip has an adjustable DC offset which provides a forward bias current for the infrared diodes. The external FSK modulator is an identical circuit but adjusted to operate at 90 and 100 kHz.
The FSK demodulator on the internal side is an XR2211 and provides a logic level output which is directly connected to the internal processor. This chip was chosen because of its large dynamic range (10 mv to 3 v rms), and its ability to operate from a single 5 volt supply. Because of the close proximity of the IR transmitter and receiver of adjacent channels, channel crosstalk is very high. Channel separation was achieved using a two stage Chebychev filter providing an inter-channel rejection of 45 dB.
It is to be understood that the examples described above are not meant to limit the scope of the present invention. It is expected that numerous variants will be obvious to the person skilled in the TET art, without any departure from the spirit of the present invention. The appended claims, properly construed, form the only limitation upon the scope of the present invention.
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An improved transcutaneous energy transfer (TET) device comprises a primary winding for placement on or near a skin surface, and a secondary winding for implantation under said skin surface. A field effect transistor (FET) is arranged to switch said primary coil across an external DC power supply. A tuning capacitor is linked to said primary coil whereby said primary coil, when said FET is turned off, will resonate at its natural frequency thereby compensating for drift in component values and reducing power transfer sensitivity to component drift. In an alternative aspect of the invention, a bidirectional communications link is provided for the transfer of data across a boundary layer by infrared signals. A plurality of transmitters are arranged in a circular pattern on one side of the boundary layer, whereas a receiver is positioned within the circular pattern along the opposite side of the boundary layer.
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BACKGROUND OF THE INVENTION
[0001] a. Field of the Invention
[0002] The instant invention relates to catheters. In particular, the instant invention relates to cardiac catheters, and further relates to catheters that are especially suited to ablation of cardiac tissue. The catheters of the present invention comprise slotted openings at their distal end, each slotted opening is arranged around the circumference of the catheter shaft and covers at least about 25% of the circumference of the catheter shaft. These slotted ablation catheters allow for effective ablation lesions to be created in a wide variety of cardiac tissue orientation.
[0003] b. Background Art
[0004] Catheters are commonly used by physicians to perform a wide variety of medical procedures on various locations in the body that would otherwise be inaccessible without more invasive procedures. In the cardiac field, catheters are frequently used for angioplasty (to open clogged blood vessels), to ablate cardiac tissue to help restore a more regular heartbeat in arrhythmia patients, or to monitor various electrical activity. Such cardiac catheters are typically tubular in shape and may comprise various electrodes, wires, optical fibers, and/or passageways for carrying and delivering fluid to cardiac tissue, depending on the purpose for which the catheter is meant.
[0005] As illustrated in FIG. 1 , a typical human heart 30 includes a right ventricle 98 , a right atrium 94 , a left ventricle 100 and a left atrium 104 . The right atrium is in fluid communication with the superior vena cava 92 and the inferior vena cava 96 . The interatrial septum separates the right atrium from the left atrium. The tricuspid valve contained within the atrioventricular septum provides a fluid flow path between the right atrium with the right ventricle. On the inner wall of the right atrium where it is connected with the left atrium is a thin walled, recessed area, referred to as the fossa ovalis. Between the fossa ovalis and the tricuspid valve is the opening or ostium for the coronary sinus. The coronary sinus is the large epicardial vein which accommodates most of the venous blood which drains from the myocardium into the right atrium.
[0006] In a normally functioning heart, contraction and relaxation of the heart muscle (myocardium) takes place in an organized fashion as electrochemical signals pass sequentially through the myocardium from the sinoatrial (SA) node (not shown) located in the right atrium to the atrialventricular (AV) node (not shown) and then along a well defined route which includes the His-Purkinje system into the left and right ventricles. Initial electric impulses are generated at the SA node and conducted to the AV node. The AV node lies near the ostium of the coronary sinus in the interatrial septum in the right atrium. The His-Purkinje system begins at the AV node and follows along the membranous interatrial septum toward the tricuspid valve through the atrioventricular septum and into the membranous interventricular septum. At about the middle of the interventricular septum, the His-Purkinje system splits into right and left branches which straddle the summit of the muscular part of the interventricular septum.
[0007] Arrhythmia is an abnormal heart rhythm that occurs in some individuals. Certain types of arrhythmia lead to significant patient discomfort and even death. Pathological causes for some arrhythmias are difficult to diagnose, but are believed to be due to stray circuits within the left and/or right atrium of the heart. These circuits or stray electrical signals are believed to interfere with the normal electrochemical signals passing from the SA node to the AV node and into the ventricles. Efforts to alleviate these problems in the past have included significant usage of various drugs. In some circumstances drug therapy is ineffective and frequently is plagued with side effects such as dizziness, nausea, and vision problems.
[0008] An increasingly common medical procedure for the treatment of certain types of arrhythmia involves the ablation of tissue in the heart to cut off the path for stray or improper electrical signals. Such procedures are typically performed with an ablation catheter. Typically, the ablation catheter is inserted in an artery or vein in the leg, neck, or arm of the patient and threaded, sometimes with the aid of a guidewire or introducer, through the vessels until a distal tip of the ablation catheter reaches the desired location in the heart. The ablation catheters commonly used to perform these ablation procedures produce lesions in cardiac tissue. The resulting lesions electrically isolate or render the tissue non-contractile at particular points. The lesion partially or completely blocks the stray electrical signals to lessen or eliminate atrial fibrillations.
[0009] The energy necessary to ablate cardiac tissue and create a permanent lesion can be provided from a number of different sources. Direct current through a laser, microwave, ultrasound, and other forms of energy have been utilized to perform ablation procedures. Because of problems associated with the use of DC current, however, radiofrequency (RF) has become one of the preferred sources of energy for ablation procedures. In addition to radiofrequency ablation catheters, thermal ablation catheters have been disclosed. During thermal ablation procedures, a heating element, secured to the distal end of a catheter, heats thermally conductive fluid, which fluid then contacts the human tissue to raise its temperature for a sufficient period of time to ablate the tissue.
[0010] In some conventional ablation procedures, the ablation catheter includes a single distal electrode secured to the tip of the ablation catheter to produce small lesions wherever the tip contacts tissue. To produce a linear lesion, the tip may be dragged slowly along the tissue during energy application. Increasingly, however, cardiac ablation procedures utilize multiple electrodes affixed to the catheter body to form multiple lesions.
[0011] One difficulty in obtaining an adequate ablation lesion using conventional ablation catheters is the constant movement of the heart, especially when there is an erratic or irregular heart beat. Another difficulty in obtaining an adequate ablation lesion is caused by the inability of conventional catheters to obtain and retain uniform contact with the cardiac tissue across the entire length of the ablation electrode surface. Without such continuous and uniform contact, any ablation lesions formed may not be adequate.
[0012] Another difficulty encountered with existing ablation catheters is assurance of adequate tissue contact. Current techniques for creating continuous linear lesions in endocardial applications include, for example, dragging a conventional catheter on the tissue, using an array electrode, or using pre-formed electrodes. These catheter designs either require significant technical skill on the part of the physician in guiding and placing the catheter by sensitive steering mechanisms. Further, all of these devices comprise rigid electrodes that do not always conform to the tissue surface, especially when sharp gradients and undulations are present, such as at the ostium of the pulmonary vein in the left atrium and the isthmus of the right atrium between the inferior vena cava and the tricuspid valve. Consequently, continuous linear lesions are difficult to achieve. A need exists for an improved catheter, particularly, a catheter design that achieves cardiac ablation effectively and independently of the orientation of target tissue. A need also exists for a catheter that addresses the vast anatomical differences found in the heart, especially, the left atrium and pulmonary veins.
BRIEF SUMMARY OF THE INVENTION
[0013] The present invention relates to a catheter for treating tissue. The catheter of the present invention comprises at least one slotted opening, spanning at least 25% of the circumference of the catheter, perpendicular to the axis of the catheter, at the catheter's distal end. Energy, heat, fluids and/or medicaments may be supplied through at least one slotted opening to treat tissue proximal or distal to such slotted opening.
[0014] One object of the disclosed invention is to provide an improved ablation catheter for forming linear lesions in tissue, including tissue within the human heart and the pulmonary veins. This and other objects are provided by the ablation catheter that is disclosed by the present invention. The ablation catheter of the present invention is capable of making improved lesions in a variety of tissue. The ablation catheter is particularly useful for ablating cardiac tissue regardless of its orientation. The distal portion of the ablation catheter comprises at least one slotted opening, the slotted opening spanning at least 25% of the circumference of the catheter. The ablation catheter is adapted to provide RF energy, conductive fluid, and/or heat through the slotted opening(s), to proximal or distal cardiac tissue. As such, the catheter may be used to ablate, for example, both the pulmonary veins and the left atrium. In some embodiments of the present invention, the ablation catheter has a curved distal end.
[0015] Disclosed herein is an ablation catheter for ablating tissue. The ablation catheter includes a catheter shaft having a proximal portion and a distal portion. The distal portion is adapted to be inserted into a body having tissue to be treated and is disposed remotely from the proximal portion. The distal portion includes a plurality of slotted openings located on a circumference of the distal portion. The slotted openings are adapted to deliver conductive fluid to the tissue to be ablated, and the plurality of slotted openings are arranged along the circumference of the catheter shaft (perpendicular to the main axis of the catheter), such that each slotted opening spans at least about 25% of the circumference of the distal portion of the catheter shaft. The ablation catheter also includes a lumen disposed within the distal portion, and the lumen is adapted to carry a conductive medium (e.g., saline). The ablation catheter also includes an electrode disposed within the distal portion of the catheter shaft, which electrode is adapted to supply ablation energy to the conductive fluid. The ablation catheter may optionally include a fluid manifold along at least a portion of the electrode. The fluid manifold may include tubing made of polyvinyl alcohol foam, expanded polytetrafluoroethylene, or a combination thereof. Optionally, the distal portion includes one or more curved sections, which may be created using one or more shape memory wires. In one configuration, the slotted openings may span about 33% of the circumference of the distal portion of the catheter shaft.
[0016] Also disclosed herein is a catheter for treating tissue, the catheter comprising a catheter shaft that has a proximal portion and a distal portion. The distal portion is adapted to be inserted into a body having tissue to be treated and has at least one slotted opening located on a circumference of the distal portion. The slotted opening is adapted to introduce a therapeutic energy, heat, fluid, or medicament to the tissue to be treated. The slotted opening is arranged perpendicular to the axis of the distal portion and spans about one third to about two thirds of the circumference of the distal portion of the catheter shaft. The distal portion of the catheter may optionally have at least one lumen adapted to carry a conductive medium. The distal portion of the catheter may also optionally have an electrode and a conductive medium manifold running along a portion of the electrode, the conductive medium manifold having a plurality of passage ways through which a conductive medium may pass. The distal portion of the catheter may also optionally have a lumen adapted to carry a conductive medium from the proximal portion to at least one slotted opening, and a metal electrode mounted within the lumen, wherein the metal electrode is adapted to supply ablation energy to the conductive medium. The metal electrode may be a platinum flat wire adapted to be connected to an RF generator by an electrical lead that extends through at least a portion of the distal portion of the catheter shaft. The disclosed catheter may have at least one curved section at its distal portion. The disclosed catheter may further have a shape memory wire at its distal portion. The shape memory wire may be located within a second lumen extending along the distal portion of the catheter shaft.
[0017] Also disclosed herein is an ablation catheter for ablating tissue, the ablation catheter having a catheter shaft having a proximal portion and a distal portion. The distal portion of the ablation catheter is adapted to be inserted into a body having tissue to be treated. The distal portion has a plurality of slotted openings located on a circumference of the distal portion, each slotted opening spanning at least about 90° of the circumference of the distal portion. The ablation catheter also has a metal electrode disposed within the distal portion, the electrode being adapted to supply ablation energy through the slotted openings to the tissue to be ablated. In one configuration, the ablation catheter also has a fluid manifold along at least a portion of the metal electrode and the slotted openings are adapted to deliver conductive fluid to the tissue to be ablated. The fluid manifold may have tubing made of a porous polymer. The slotted openings of the ablation catheter may span about 120° to about 240° of the circumference of the distal portion.
[0018] Disclosed herein are also methods for treating cardiac arrhythmia. In one such method, an ablation catheter is inserted into a patient having cardiac tissue to be treated. The ablation catheter has a proximal portion and a distal portion, the distal portion comprising a plurality of slotted openings, adapted to introduce ablative energy to the cardiac tissue to be treated. The slotted openings of the ablation catheter are located on a circumference of the distal portion and span between about 90° and about 270° of the circumference of the catheter shaft. The ablation catheter also has an electrode disposed within the distal portion, the electrode has a fluid manifold along at least a portion of the electrode, and the electrode is adapted to be connected to an ablative energy source. The plurality of slotted openings permit the catheter to ablate tissue in both the posterior wall of the left atrium and the pulmonary vein. The ablation catheter is placed along the catheter tissue to be treated. An ablative energy is applied to the ablation catheter to form lesions on the cardiac tissue.
[0019] In another disclosed method, tissue that is in at least two different orientations within a body is simultaneously ablated using an ablation catheter of the present invention. The ablation catheter is inserted into a patient having tissue to be ablated, the ablation catheter having a proximal portion and a distal portion, the distal portion having a plurality of slotted openings. The slotted openings are adapted to introduce ablative energy to the tissue to be treated and are located on a circumference of the distal portion. Each slotted opening spans between about 33% and about 67% of the circumference of the catheter shaft. The ablation catheter has an electrode disposed within the distal portion, the electrode is adapted to be connected to an ablative energy source. The ablation catheter is placed along the tissue to be treated and ablative energy is applied to form lesions simultaneously on tissue that is in at least two different orientations.
[0020] The catheters of the present invention, with the slotted openings on their distal portions, are effective for treating a wide variety of tissue in a wide variety of orientations. The ablation catheter of the present invention can simultaneously create lesions in pulmonary veins and on atrial walls. The ablation catheter of the present invention is also effective for simultaneously creating lesions on the posterior wall of the left atrium and in the pulmonary veins. The catheters of the present invention thus save treatment time because the catheter does not have to be rearranged between treatments and one catheter accommodates vast anatomical differences in various tissue surfaces, especially in various cardiac surfaces.
[0021] The foregoing and other aspects, features, details, utilities, and advantages of the present invention will be apparent from reading the following description and claims, and from reviewing the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] FIG. 1 is a partial cut away diagram of a human heart.
[0023] FIG. 2 is an isometric view of an ablation catheter assembly according to the present invention.
[0024] FIG. 3A is a fragmentary view of a distal portion of a catheter.
[0025] FIG. 3B is a fragmentary view of a distal portion of another catheter.
[0026] FIG. 3C is a fragmentary view of a distal portion of a catheter according to the present invention.
[0027] FIG. 3D is a fragmentary view of a distal portion of a catheter according to the present invention.
[0028] FIG. 4A is a cross-sectional view of the distal portion of the catheter depicted in FIG. 3A .
[0029] FIG. 4B is a cross-sectional view of the distal portion of the catheter depicted in FIG. 3B .
[0030] FIG. 4C is a cross-sectional view of the distal portion of the catheter depicted in FIG. 3C .
[0031] FIG. 4D is a cross-sectional view of the distal portion of the catheter depicted in FIG. 3D .
[0032] FIG. 5A is a fragmentary view of the distal portion of a curved ablation catheter, looking perpendicular to the longitudinal axis of the catheter shaft.
[0033] FIG. 5B is a fragmentary view of the distal portion of the ablation catheter depicted in FIG. 5A , looking from the top of the distal portion down the longitudinal axis of the catheter shaft.
[0034] FIG. 6A is a fragmentary view of the distal portion of another curved ablation catheter, looking perpendicular to the longitudinal axis of the catheter shaft.
[0035] FIG. 6B is a fragmentary view of the distal portion of the ablation catheter depicted in FIG. 6A , looking from the top of the distal portion down the longitudinal axis of the catheter shaft.
[0036] FIG. 7A is a fragmentary view of the distal portion of a curved ablation catheter according to the present invention, looking perpendicular to the longitudinal axis of the catheter shaft.
[0037] FIG. 7B is a fragmentary view of the distal portion of the ablation catheter depicted in FIG. 7A , looking from the top of the distal portion down the longitudinal axis of the catheter shaft.
[0038] FIG. 8 is an isometric view of the ablation catheter depicted in, for example, FIGS. 7A and 7B , creating lesions on opposing vessel walls.
[0039] FIG. 9 is an isometric view of a heart with portions of the atria and ventricles broken away to reveal positioning of the ablation catheter depicted in, for example, FIGS. 7A and 7B , creating lesions in the left atrium.
[0040] FIG. 10 is an isometric view of a heart with portions of the atria and ventricles broken away to reveal positioning of the ablation catheter depicted in FIG. 9 creating lesions in the left superior pulmonary vein
[0041] FIG. 11 is an isometric view of a heart with portions of the atria and ventricles broken away to reveal position of the ablation catheter depicted in FIG. 9 creating lesions in both the left atrial wall and the left superior pulmonary vein simultaneously.
DETAILED DESCRIPTION OF THE INVENTION
[0042] In general, the instant invention relates to a catheter for treating tissue. As is well known in the art, the catheter of the present invention has a catheter shaft with a proximal portion and a distal portion. FIGS. 3A and 3B show configurations for the distal portion of catheters known in the art. As is shown in FIG. 3A , the distal portion 190 of some catheters currently in use has a plurality of portholes 200 giving access to the inside of the catheter 225 . Depending on the use for which such catheter is intended, the inside of the catheter may comprise a lumen for carrying conductive media or various medicaments, an electrode, a manifold, or any other equipment or substances necessary for treating tissue the catheter is intended to treat. Energy, heat, and/or medicaments may be supplied through the slotted openings to treat tissue proximal to such slotted opening. FIG. 3B shows another configuration for the distal portion 190 of a catheter known in the art. In the configuration of FIG. 3B , the distal portion 190 has a vertical slit 250 running parallel to the axis of the catheter shaft and exposing the inside of the catheter 225 . FIGS. 4A and 4B further show a cross section of the known catheter configurations shown in FIGS. 3A and 3B .
[0043] FIG. 3C shows one embodiment of a catheter of the present invention. The distal portion 190 of the catheter shaft has at least one slotted opening 300 located on a circumference of the distal portion of the catheter. The slotted opening 300 spans at least about 25% (i.e., about 90°) of the catheter circumference. In one preferred embodiment, the distal portion comprises a plurality of slotted openings 300 and each slotted opening spans approximately 33% (i.e., about 120°) of the catheter circumference. The slotted openings 300 may span up to about two thirds (about 240°) of the catheter circumference, three quarters (270°) of the catheter circumference, or more. Preferably, the slotted openings will not affect the structural integrity of the catheter shaft. As illustrated in FIG. 3C , however, the present invention provides a catheter that can be used to treat multiple tissue surfaces having multiple orientations. This is a significant advantage over the prior art.
[0044] FIG. 3D shows another embodiment of a catheter of the present invention. The distal portion 190 has a plurality of sets of slotted openings 301 and 302 located on a circumference of the distal portion of the catheter. Each slotted opening spans at least about 25% of the circumference of the catheter. As illustrated in FIG. 3D , however, the present invention provides invention may be made of a variety materials. In a preferred embodiment of the ablation catheter of the present invention, catheter comprises a metal electrode (e.g., platinum). In a further preferred embodiment, the electrode is a platinum flat wire adapted to be connected to an RF generator by an electrical lead that extends through at least a portion of the distal portion of the catheter shaft.
[0045] FIG. 2 is an isometric view looking downwardly at an ablation catheter assembly 10 according to the present invention. In this embodiment of the catheter assembly 10 , an ablation catheter 18 comprising a catheter shaft 22 having a proximal portion 24 and a distal portion 12 is used in combination with one or more guiding introducers 26 , 28 to facilitate formation of lesions on tissue, for example, cardiovascular tissue. As depicted in FIG. 2 , the ablation catheter 18 may be used in combination with an inner guiding introducer 28 and an outer guiding introducer 26 . Alternatively, a single guiding introducer may be used or a precurved transeptal sheath may be used instead of one or more guiding introducers. In general, the introducer, introducers, or precurved sheath are shaped to facilitate placement of the ablation catheter 18 at the tissue to be ablated. Thus, for example, the introducer or the introducers or the transeptal sheath make it possible to navigate to the heart and through its complex physiology to reach specific tissue to be ablated. When the ablation catheter 18 has a specific configuration like the curved configuration depicted in FIGS. 2 , 5 A, 5 B, 6 A, 6 B, 7 A, and 7 B, the shape of the introducers 26 , 28 , if used, may change somewhat when the distal portion 12 of the ablation catheter 18 is retracted into the introducers 26 , 28 . A conductive fluid medium (e.g., hypertonic saline) contacting the electrode and the tissue to be ablated may comprise a virtual electrode, eliminating the need for direct contact between the electrode and the tissue to be ablated.
[0046] As further described in U.S. Pat. Nos. 7,122,034 and 7,101,362, and U.S. patent application Ser. No. 11/328,565, (all of which are incorporated herein by reference in their entireties) curved configuration catheters preferably have a catheter shaft comprising at least one curved section. The curved section may be formed by a memory wire within a lumen disposed within the catheter. Such catheters may comprise dual lumen systems to separate the memory wire from an electrode or multiple electrodes.
[0047] FIG. 5A depicts an embodiment of a known ablation catheter with a curved configuration at its distal end. The distal portion 190 of this catheter comprises a plurality of portholes 200 along the length of the curved distal portion 190 , the portholes 200 face outward and perpendicular to the axis 205 of the catheter shaft. FIG. 5B shows the catheter of FIG. 5A viewed from the top of the distal portion down the longitudinal axis of the catheter shaft, showing the portholes 200 in outward alignment from the curved distal portion 190 .
[0048] FIG. 6A depicts an embodiment of another known ablation catheter with a curved configuration at its distal end. The distal portion 190 of this catheter comprises a plurality of portholes 200 along the length of the curved distal portion 190 , the portholes 200 facing upward, or forward, along the axis 205 of the catheter shaft. FIG. 6B shows the catheter of FIG. 6A viewed from the top of the distal portion down the longitudinal axis of the catheter shaft, showing the portholes 200 in upward alignment on the curved distal portion 190 .
[0049] The present invention is effective for simultaneously creating lesions in pulmonary veins and on atrial walls. The present invention is also effective for simultaneously creating lesions in the posterior wall of the left atrium and in the pulmonary veins.
[0050] FIG. 7A depicts an embodiment of an ablation catheter according to the present invention. The curved distal portion 190 comprises at least one slotted opening 300 . The slotted opening 300 spans at least about 25% of the circumference of the catheter and may be located at any point along the circumference of the catheter shaft. In one preferred embodiment, the distal portion 190 of the catheter comprises a plurality of slotted openings, each slotted opening spanning about 33% of the circumference of the catheter. In a further preferred embodiment, as shown in FIG. 7A , the plurality of slotted openings cover at least a portion of the upper forward surface of the catheter shaft and at least a portion of the outward surface of the catheter shaft. The slotted openings of the ablation catheters of the present invention create expanded access to the electrode 350 within the catheter from a variety of geometries. The configurations of the curved ablation catheters of the present invention are thus able to treat a variety of tissue regardless of tissue orientation. These novel curved ablation catheters with slotted openings can effectively form lesions in, for example, both the pulmonary veins and the posterior wall of the left atrium.
[0051] In one embodiment of the ablation catheter of the present invention, as shown in FIG. 7A , the slotted openings 300 have square ends 320 , but the slotted openings 300 may also have rounded ends or ends of any other functional geometry. The slotted openings 300 may also be of any desired width and may span two thirds of the catheter circumference or more. Preferably, the slotted openings are configured to not affect the structural integrity of the catheter shaft. In one preferred embodiment of the present invention, the novel catheter has a distal end with a plurality of slotted openings, 300 , the slotted openings 300 have rounded ends and may be preferably from about 0.5 mm to about 3.0 mm in width. The slotted openings 300 on the distal portion 190 of the catheter may each be of equal arc length and width or may have differing arc lengths and/or widths.
[0052] The catheter shaft of the curved ablation catheter of the present invention may be made of a variety of materials, including without limitation, polymeric materials such as PELLETHANE, polypropylene, oriented polypropylene, polyethylene, crystallized polyethylene terephthalate, polyethylene terephthalate, polyester, and polyvinyl chloride. The distal portion of the curved ablation catheter may also have only one curved portion or may have a plurality of curved portions to form, for example, a “C” shape or a circular shape.
[0053] As shown in FIGS. 8-11 , the curved ablation catheters of the present invention may be used to treat cardiac arrhythmias. In one embodiment of such a method of the present invention, as shown in FIG. 10 , the distal portion 12 of the ablation catheter 18 has been inserted into the left superior pulmonary vein 50 . While the ablation catheter 18 is in the pulmonary vein, the electrode would be activated to create the desired lesion in the left superior pulmonary vein 50 . FIG. 9 shows the same ablation catheter as depicted in FIG. 10 being used to form lesions on the posterior wall of the left atrium 104 . FIG. 11 further shows the same ablation catheter forming lesions on the posterior wall of the left atrium 104 and on the left superior pulmonary vein 50 at the same time. FIG. 8 shows the same ablation catheter as depicted in FIGS. 9 and 10 , forming lesions on vessel walls 400 and 410 of varied geometry. FIG. 8 illustrates the ability of the present invention to address the vast anatomical differences in the cardiac area. The present invention allows for these anatomical differences because the electrode will function effectively regardless of the orientation of the tissue. As illustrated in FIG. 8 , the present invention can be used to ablate tissue in multiple regions that are oriented differently, and the invention can do so with a single treatment. For example, as shown in FIG. 8 , the ablation catheter of the present invention can treat a vertical vessel wall 410 and a horizontal vessel wall 400 at the same time. This constitutes a significant advantage over the prior art.
[0054] In one preferred embodiment, an RF electric current emanating from a metal electrode disposed within the catheter passes through the conductive fluid medium (e.g., saline) contained in a lumen in the catheter through the slotted openings and into the adjacent tissue. The conductive fluid medium may experience ohmic heating as it flows along the metal electrode and out the slotted openings. Ablation energy is delivered to the tissue via the conductive medium. Thus, a lesion is formed in the tissue by the RF energy. Lesion formation may also be facilitated by the conductive fluid medium, which may have been heated by ohmic heating to a sufficiently high temperature to facilitate or enhance lesion formation, flowing out the slotted openings. While the RF energy is being conducted into the adjacent tissue, the heated conductive fluid medium convectively affects the temperature of the tissue. In order to form a sufficient lesion, it is desirable to raise the temperature of the tissue to at least 50° C. for an appropriate length of time (e.g., one minute). Thus, sufficient RF energy must be supplied to the metal electrode to produce this lesion-forming temperature in the adjacent tissue for the desired duration.
[0055] Although preferred embodiments of this invention have been described above with a certain degree of particularity, those skilled in the art could make numerous alterations to the disclosed embodiments without departing from the spirit or scope of this invention. For example, the slotted openings can be of any width and any number, arranged in any variety of proximity from one to the next. The catheters of the present invention may also comprise a combination of slotted openings along the circumference of the catheter, perpendicular to the axis of the catheter, and long slits running along the axis of the catheter. Further, all directional references (e.g., upward, downward, outward, left, and right) are only used for identification purposes to aid the reader's understanding of the present invention, and do not create limitations, particularly as to the position, orientation, or use of the invention. It is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative only and not limiting. Changes in detail or structure may be made without departing from the spirit of the invention as defined in the appended claims.
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A catheter for treating tissue is disclosed, the catheter having slotted openings on a circumference of its distal portion, wherein each slotted opening spans at least about 25% of the circumference of the catheter. The disclosed catheter is capable of treating a variety of tissue in a variety of configurations. For example, in an ablation catheter of the disclosed invention, the slotted openings on the distal portion allow the ablation catheter to create effective lesions in both the pulmonary veins and the posterior wall of the left atrium. The ablation catheter preferably carries a conductive medium to help deliver ablation energy (e.g., RF) to the tissue being ablated. The configuration of the catheter permits ablation to be conducted in many varieties and geometric orientations independently of the tissue orientation. Also disclosed is a method of ablating tissue using catheter with slotted openings.
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BACKGROUND OF INVENTION
[0001] The present invention relates generally to air filters and more particularly to an improved grease trap air filter to be used as a heat transfer mechanism. The present invention relates to a combined system which simultaneously filters grease and particulate from hot fumes and transfers heat to a fluid circulating inside the system. The heated fluid may then be used to supply heat for other purposes, such as heating water or air.
[0002] During the operation of commercial or institutional kitchens, a significant amount of valuable heat energy is lost as a result of hot fumes and/or air being vented to the atmosphere. These hot fumes are generated from cook stoves, hot plates, deep fat fryers, and other cooking apparatus. As a result of such extreme heat and variety of particulates generated during cooking, it is necessary for the comfort and health of kitchen workers to exhaust these fumes, usually on a continuous basis, through flue chimneys or similar venting devices. This process effectively replaces the hot kitchen air with cooler, clean outside air. Although this circulation process is necessary to provide a constant source of clean air to the kitchen environment, this venting practice is both inefficient and uneconomical, especially in colder climates where the cost to heat internal air and water is significant.
[0003] A further problem encountered in commercial kitchens is the filtering of grease and other particulates entrained in the hot fumes generated during the cooking of foods. If improperly filtered, this grease can cause fouling and the eventual malfunction of air ventilation systems, as well as create fire hazards if allowed to accumulate. Accordingly, hot fume air filters, which are normally located in fume hoods over cooking surfaces, are generally required to be cleaned daily, or at a minimum of 2-3 times a week. This tedious cleaning process is both time consuming and expensive.
[0004] The use of heat exchangers to capture thermal energy above cooking surfaces has been known for years. These designs, however, position the heat exchangers substantially downstream of existing grease filters. This approach is unfavorable for at least three reasons. First, these designs are inefficient since the heat exchanger is located downstream of the grease filter and a significant distance from the heat source. Thus, valuable thermal energy is lost by absorption into the grease filter and through general dissipation prior to the heat reaching the exchanger. Second, the grease filters currently being used upstream of the heat exchangers significantly impede air flow, especially when congested with grease, hence reducing the efficiency of the air ventilation system and heat transfer efficiency. Third, when the heat source is turned off, the grease quickly solidifies on the prior filters, which usually include heat exchange fins, and requires cleaning for both safety and efficiency. Finally, despite the existence of these kinds of heat exchangers generally, many existing kitchens fail to incorporate any kind of heat exchanger due to integration costs. Retrofitting existing kitchen equipment with heat exchanger systems may require an entirely new flue hood assembly and substantial piping and accessories. This conversion is both time consuming and expensive. While some improvements have been made to combine a filter and heat exchanger, such as in U.S. Pat. No. 5,456,244, there remains room for improvement in the art. For instance, there is room for a filter unit having simplified construction, using less material and providing more complete heat transfer than prior devices.
SUMMARY OF INVENTION
[0005] Embodiments of the present invention include systems and methods related to filter units having simplified construction, using less material and providing more complete heat transfer than prior devices.
[0006] An embodiment of a filter unit according to the present invention comprises a housing including a cavity, and a heat exchanger disposed substantially within the cavity. Through the housing is provided at least one entrance aperture provided on an upstream side of the heat exchanger. On the downstream side of the heat exchanger, opposite the upstream side, at least one baffle is provided on the housing. Also on the downstream side of the heat exchanger, at least one exit aperture is provided through the housing. The at least one baffle is aligned with the at least one entrance aperture, such that when a gas is drawn through the at least one entrance aperture and across the heat exchanger, the baffle redirects the gas towards the heat exchanger prior to the gas leaving the cavity through the at least one exit aperture.
[0007] According to one aspect of a filter unit according to the present invention, the housing comprises a base and a cover. The base may include a substantially planar base wall having a base wall perimeter and a plurality of lateral sidewalls coupled to the base wall perimeter substantially encircling the base cavity. The at least one entrance aperture may be formed through the base wall. The base wall perimeter may be substantially rectilinear.
[0008] According to another aspect of a filter unit according to the present invention, the base may further include at least one fin member extending at least partially across one of the at least one entrance aperture into the cavity at an oblique angle relative to the base wall. The base may include a pair of fin members extending partially across each entrance aperture into the cavity at an oblique angle relative to the base wall.
[0009] According to yet another aspect of a filter unit according to the present invention, the cover may include a substantially planar cover plate having a cover plate perimeter and at least one lateral cover sidewall coupled to and extending at an oblique angle from the cover plate, the at least one lateral cover sidewall adapted to extend into the housing cavity, where the at least one exit aperture is formed through the cover plate.
[0010] According to still another aspect of a filter unit according to the present invention, wherein the heat exchanger may include a first header pipe extending between a first end and a second end and a second header pipe spaced from the first header pipe, the second header pipe extending between a third end and a fourth end. At least one of the first and second ends and/or at least one of the third and fourth ends may be closed. At least one fluid flow conduit may be disposed between and in fluid communication with the first header pipe and the second header pipe, wherein the header pipes and at least one fluid flow conduit define a fluid cavity. A first fluid port may be provided on the first header pipe in fluid communication with the fluid cavity, and a second fluid port may be provided on the second header pipe in fluid communication with the fluid cavity.
[0011] According to a further aspect of a filter unit according to the present invention, the first and second header pipes may be substantially longitudinally straight pipes disposed at least substantially parallel to each other.
[0012] According to a still further aspect of a filter unit according to the present invention, a plurality of fluid flow conduits may be provided at least substantially parallel to each other and at least substantially orthogonal to the header pipes.
[0013] According to another aspect of a filter unit according to the present invention, a heat exchanger may include a heat-conductive material at least partially coated with a reduced friction material, such as polytetrafluoroethylene.
[0014] A system according to the present invention includes a cooking surface including a heat source and an exhaust system adapted to draw in gasses that are disposed above the cooking surface, the exhaust system providing a gas flow path for the gasses. Disposed in the gas flow path is a filter unit that includes a housing including a cavity and a first heat exchanger disposed substantially within the cavity, the first heat exchanger including a fluid input port and a fluid output port. At least one entrance aperture may be provided through the housing on an upstream side of the first heat exchanger, and at least one baffle may be provided on the housing on a downstream side of the first heat exchanger, the downstream side being oppositely disposed of the upstream side. Through the housing, on the downstream side of the first heat exchanger, at least one exit aperture is provided. The at least one baffle is aligned with the at least one entrance aperture, such that when the gasses are drawn through the at least one entrance aperture and across the first heat exchanger, the baffle redirects the gasses towards the first heat exchanger prior to the gasses leaving the cavity through the at least one exit aperture. The system further includes fluid supply coupled to the input port and a drain line coupled at a drain upstream end to the output port and at a drain downstream end to one or more of a storage tank and a second heat exchanger.
[0015] According to another aspect of a system according to the present invention, the second heat exchanger is selected from the group consisting of: a radiator adapted to heat an indoor space, a length of heat-conductive tubing disposed in or below a walking surface, and a length of heat-conductive tubing disposed on a roof of a building.
[0016] According to yet another aspect of a system according to the present invention, the drain line is coupled to the second heat exchanger and a third heat exchanger. Each of the second heat exchanger and the third heat exchanger may be selected from the group consisting of: a radiator adapted to heat an indoor space, a length of heat-conductive tubing disposed in or below a walking surface, and a length of heat-conductive tubing disposed on a roof of a building.
[0017] According to a further aspect of a system according to the present invention, the cooking surface may be disposed substantially parallel to horizontal level, the filter unit further comprising a substantially planar base wall arranged at an oblique angle relative to the cooking surface. The angle is preferably from about 10 degrees to about 60 degrees, and more preferably about 12 degrees to about 45 degrees.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is a perspective view of an embodiment of a filter unit according to the present invention.
[0019] FIG. 2 is a partial assembly view of the embodiment of FIG. 1 .
[0020] FIG. 3 cross-sectional view taken along line 3 - 3 of FIG. 1 .
[0021] FIG. 4 is a side elevation view of an embodiment of a heat exchanger included in the embodiment of FIG. 1 .
[0022] FIG. 5 is a perspective view of an embodiment of a bottom filter housing included in the embodiment of FIG. 1 .
[0023] FIG. 6 is a perspective view of an embodiment of a top filter housing included in the embodiment of FIG. 1 .
[0024] FIG. 7A is a partial cutaway view of a first embodiment of an open system utilizing an embodiment of a filter unit according to the present invention.
[0025] FIG. 7B is a partial cutaway view of a second embodiment of an open system utilizing an embodiment of a filter unit according to the present invention.
[0026] FIG. 8 is a partial cutaway view of a first embodiment of a closed system utilizing an embodiment of a filter unit according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0027] Although the disclosure hereof is detailed and exact to enable those skilled in the art to practice the invention, the physical embodiments herein disclosed merely exemplify the invention which may be embodied in other specific structures. While the preferred embodiment has been described, the details may be changed without departing from the invention, which is defined by the claims.
[0028] Turning now to the figures, FIG. 1 depicts an embodiment 100 of a filter unit, or cartridge, according to the present invention. The filter unit 100 comprises a housing 110 and a heat exchanger 170 . The housing 110 generally surrounds the heat exchanger 170 and may be comprised of one or more pieces. The preferred housing is preferably two pieces including a base 112 and a cover 114 . The base 112 may be formed in a configuration that is substantially a parallelepiped with an open top 116 . If formed as such, the base 112 includes a base wall 118 and a plurality of lateral sidewalls 120 . The base 112 may be formed from a cruciform shape that is stamped or otherwise formed out of a generally planar sheet material, such as sheet stainless steel of a desired thickness. Once stamped, the lateral sidewalls 120 may be bent towards each other, thus forming a base cavity 122 . Alternatively, the sidewalls 120 may be coupled to the base wall 118 , such as by welding. There may be a gap 122 a between adjacent sidewalls 120 or the gap 122 a may be closed with a sealant or welded. Additionally or alternatively, the plurality of sidewalls 120 may be formed as a unitary member, such as in a ring formation, and coupled to the base wall 118 .
[0029] The base wall 118 is preferably perforate, including one or more air portals 124 formed therethrough, to allow air to pass into the base cavity 122 through the base wall 118 . Various shapes of the base wall 118 are contemplated, although a generally planar, rectilinear shape is preferred for ease of manufacture and installation. In addition, such shape is easily adaptable to be utilized with filter assembly units, or exhaust hoods, that are presently provided in commercial cooking settings. Furthermore, it is preferred that the shape of the filter unit 100 be at least laterally symmetrical, such that the unit may be inserted into a given hood or exhaust assembly in a plurality of orientations, so as to provide ease of connectivity. Indeed, the filter unit is preferably rotationally symmetrical in at least one plane.
[0030] The openings 124 formed in the base wall 118 of the base 112 preferably perform at least a slight nozzling function on air entering the housing 110 . This may be accomplished by an arrangement of pairs of fins 126 adapted to extend from the openings 124 towards each other. In other words, a pair of fins 126 a , 126 b may be provided for each aperture 124 , wherein each fin 126 extend into the base cavity 122 and toward the associated fin 126 in the respective pair. Thus, each opening is preferably wider at its upstream side 124 a and narrower at its downstream side 124 b. The fins 126 may be formed from the same material as the base wall 118 , and indeed may be stamped and formed from the same piece of material as the base wall 118 , and then bent into the base cavity 122 . Additionally or alternatively, the fins 126 may be provided as separate components that are preferably stationarily coupled with respect to the base wall 118 . If provided as separate components, two fins 126 may be provided as coupled together, perhaps as a unitary member including a fin plate 126 c disposed between the two fins 126 . The fin plate 126 c may be include a substantially planar surface extending along a length, proximate end portions of which are secured to the base wall 118 . The preferred nozzling function provided by the arranged fins 126 focuses the airflow towards a baffle 138 that is included on the cover 114 , or that is at least disposed on the opposite side of the heat exchanger 170 from the fins 126 , and therefore assist in the collection of grease particles. Also as later discussed, the direction of airflow creates a turbulent airflow to increase exposure time of the air with the heat exchanger 170 . Accordingly, it is preferred that no direct airflow path is created through the filter assembly 110 , or a majority of the airflow therethrough is not direct. Rather, one or more tortuous airflow paths 201 are created thereby allowing for a turbulent flow that exposes the heated air to the heat exchanger 170 for a sufficient amount of time to allow for adequate heat exchange to a fluid contained therein.
[0031] Also on the base 112 , one or more retainer tabs 128 are preferably formed on at least one of the lateral side members 120 , preferably on two opposing lateral side members 120 . A preferred retainer tab 128 is a punched extrusion from the lateral side member 120 so as to form a spring type retention force. Also provided on the base 112 is at least one and preferably a plurality of handles 130 , which may be formed in a variety of ways. Preferably, the handles 130 are provided in opposing positions on the assembly 100 to allow for balanced insertion and removal of the filter unit 100 . The preferred handles 130 are full or partial wire loop handles that are suspended from handle brackets 132 that may be formed integrally with or coupled to the base wall 118 .
[0032] In addition to acting as a heat exchanger, a filter unit 100 according to the present invention may serve as an air filter which assists in the collection of grease particles, which is especially advantageous to be used over commercial cooking surfaces. To aid in the drainage of collected grease particles, the base 112 may be provided with one or more drain holes 133 formed therethrough. A plurality of drain holes 133 is preferred, and they may be formed along the juncture of one or more of the lateral side members 120 and the base wall 118 .
[0033] The cover 114 preferably generally comprises a plate 134 , and may further include one or more lateral side members 136 extending from the plate 134 . The side members 136 may be provided in a length 136 a that allows insertion of the side members 136 between header pipes 172 of the heat exchanger 170 . Furthermore, the side members 136 may be formed with one or more heat exchanger interfaces 136 b, which may contact and/or surround a portion of the heat exchanger 170 to maintain position during and after installation. The cover 114 may be formed as a symmetrical shape that may be inserted into the base 112 in a plurality of orientations. Formed integrally with or coupled to the plate 134 are one or more baffles 138 that are disposed opposite the apertures 126 formed in the base 112 so as to assist in creating the tortuous air flow path through the filter unit 100 . The baffles 138 are preferably arranged to act as a one or more diffusers, such that the upstream side 140 a of openings 140 disposed between the baffles 138 is smaller than the downstream side 140 b. The baffles 138 may be formed similar or identical to the unitary fin members, discussed above. It is thought that the nozzle effect provided by the base 112 and the diffuser effect on the cover 114 actually assist in the creation of the tortuous airflow path 150 to aid in the collection of grease and to maximize or assist in the heat transfer to fluid in the heat exchanger 170 .
[0034] The filter base 112 and cover 114 assemblies are preferably formed from stainless steel, though other materials are certainly contemplated, such as aluminum, copper, steel and others. A plastic housing could also be used, but is not generally preferred due to a desirability of durability in cleaning and repair. Further, plastic has demonstrated affections for grease, which may be caused by its insulative properties, and therefore it may require more frequent cleaning.
[0035] The heat exchanger 170 is preferably formed from two header pipes 172 , which may be provided in a parallel arrangement, and a plurality of fluid flow conduits 174 , which also may be provided in a parallel arrangement, extending between the two header pipes 172 . The heat exchanger 170 is preferably sized so as to be positioned substantially within the base cavity 122 . Such arrangement provides a fluid flow chamber 176 within the header pipes 172 and conduits 174 , through which a preferred fluid may be caused to flow. A preferred fluid may be a potable fluid, such as water or propylene glycol. Alternatively, a serpentine fluid flow chamber arrangement could be used. However, in the provided embodiment, less structural material may be required due to increased air exposure time to the heat exchanger 170 caused by the tortuous airflow paths. While the heat exchanger 170 could be formed asymmetrically, it is preferably at least rotationally symmetrical in at least one plane, such that it may be inserted into the base cavity 122 in a plurality of orientations. In a preferred embodiment, each header 172 is provided with a fluid port 178 in fluid communication with the fluid flow chamber 176 . The ports 178 may be provided with threads 179 or other coupling mechanism, such as a standard fluid quick connect coupling, to be connected to a fluid supply or drain. Preferably, as shown, the ports 178 are provided on opposite ends of their respective header 172 . Vibration pads 180 may be provided on one or more components of the filter unit 100 . Preferably, a plurality of pads 180 is adhered to each header pipe 172 in the heat exchanger 170 . The vibration pads 180 are adapted to cooperate with the base wall 118 to prevent a rattling of two or more of the components.
[0036] A preferred material for one or more, and preferably a majority, of the components of the heat exchanger is copper, which may be coated with a non-stick material, such as a paint including polytetrafluoroethylene, available as a Teflon® material, available from E.I. du Pont de Nemours and Company of Wilmington, Del. The non-stick material may be painted onto the desired heat exchanger components. Another acceptable material for the heat exchanger headers 172 and conduits 174 is steel tube, which may also be painted with a non-stick material.
[0037] In use, a filter unit 100 according to the present invention is inserted into a filter housing or holding unit above a cooking surface. As can be seen in the cross section of FIG. 3 , the combination of the fins 126 and baffles 138 create tortuous, or non-sightline fluid flow paths 150 for exhaust air to enter through the base wall 118 and exit through the cover plate 134 . The air paths 150 are directed around the fluid flow conduits 174 included in the heat exchanger 170 . Accordingly, a majority of the conduits 174 are exposed directly to heated air flow, and not just a portion thereof. Such exposure combined with the turbulent nature of the airflow mechanism helps with the efficiency of the device.
[0038] Generally, systems and methods according to the present invention may be used to collect heat generated by a cooking surface, which would otherwise be wasted as exhaust, and transfer such heat to other locations for use in an open or closed circulation system. As can be seen in FIG. 7A , one or more filter units 100 may be installed in an exhaust housing 200 , preferably above a cooking surface 202 . While the filter 100 could be installed at any desirable angle, such as parallel to horizontal level, it is preferably installed at an angle 204 relative to horizontal level, the angle 204 being disposed at between about 12 degrees and about 45 degrees for most efficient drainage of collected oil particles, thus disposing the longitudinal dimension of the fins 124 and baffles 138 at approximately such angle.
[0039] Collected oil may drain out of the provided drain holes 133 and into one or more grease traps 203 . As further shown in FIG. 7 , a plurality of filter units 100 may be coupled together to form an expanded filter unit. The units 100 may be coupled in series, as shown, or in parallel. If coupled in series, a coupler 205 may be connected at one end to a drain port 178 of one filter unit 100 A and at the other end to a supply port 178 of a subsequent filter unit 100 B, and so on. If coupled in parallel, a supply port 178 on each unit 100 is coupled to a fluid supply line and a drain port 178 on each unit 100 can be coupled to a
[0040] A system utilizing the filter unit(s) 100 of the present invention may be an open system, such as when the heated fluid is removed from the system and put to some other use, such as dishwashing, or it is stored for future use. FIG. 7A depicts an open system. Water or other desirable fluid may be provided by gravity pressure, such as from an elevated supply tank 210 or municipal water supply, or it may be pumped to the system. Conduit 212 and standard connections may be used to couple the water supply to a first filter unit 100 A. The fluid is allowed to flow through one or more filter units 100 , and then drain into a storage tank 214 for future use, such as being pumped to a dishwasher, hot water supply in a restroom, or used for other purposes.
[0041] An enhanced open system can be seen in FIG. 7B . In addition to the storage tank 214 , the enhanced system may include a water heating tank 216 and a recirculating pump 218 . The plumbing diagram of Figure 7 B will be readily understood by a person having ordinary skill in the art, as including various check valves 220 and shut-off valves 222 in desired positions. One advantage to this enhanced system is that if fluid usage is not keeping up with the supply of heated fluid, fluid stored in the storage tank 214 may be recirculated to keep it warm in the event of demand increase. The recirculating pump 218 may be selectively activated and deactivated, such as on a time schedule or based upon a measured temperature of the fluid in the storage tank 214 falling below a predetermined threshold.
[0042] Additionally or alternatively, the system may be a closed system, where the goal may be to transfer the heat from the exhaust gases and put the heat to use elsewhere. An example of a closed system is shown in FIG. 8 . In this system, water or other fluid is introduced into the closed system and substantially all of any residual air is purged. The fluid may be pumped through the system by an inline pump 310 , through conduit 212 and through one or more filter units 100 . After traveling through the one or more filter units 100 , in which the fluid was heated by exhaust from the cooking surface 202 , the fluid may then be caused to travel through one or more additional heat exchangers. For instance, the fluid may be pumped through a radiator 312 to heat a room. Additionally or alternatively, the fluid may be pumped through a roof heat exchanger 314 disposed along the edge of the roof 316 of the building in which the system is housed, to prevent ice damming. Additionally or alternatively, the fluid may be pumped through a sidewalk heat exchanger 318 disposed beneath or embedded in a concrete or other external walkway 320 to reduce the buildup of ice thereon. It is to be appreciated that the function of a system according to the present invention may be changed depending upon the time of year. For instance, in summer months, it may not be desirable to use a closed system for heating purposes as described. In such situations, the fluid may remain static and the filter units 100 may simply be used to collect oil particulates from the exhaust air. Alternatively, the closed system could be changed to an open system in the summer months, thereby providing hot water for use.
[0043] The foregoing is considered as illustrative only of the principles of the invention. Furthermore, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described. While the preferred embodiment has been described, the details may be changed without departing from the invention, which is defined by the claims.
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An embodiment of filter unit heat exchanger according to the present invention provides improved operability and manufacturability. Such device may include a housing substantially surrounding a heat exchange assembly. Provided through the housing are one or more tortuous fluid flow paths used to direct airflow therethrough around portions of the heat exchange assembly for efficient operation. The tortuous path(s) may be provided by one or more nozzle apertures on an input side of the housing and one or more diffuser apertures on an output side of the housing, where the nozzle apertures and diffuser apertures are offset to cause desired airflow deflection. The filter unit may include desired symmetries so as to improve manufacturability and/or installation.
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GOVERNMENT RIGHTS
The invention was made with Government support under contracts F29601-96-C-0097 and F29601-98-C-0165 awarded by the United States Air Force. The Government has certain rights in the invention.
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation in part of U.S. application Ser. No. 08/963,366 filed Nov. 3, 1997, now U.S. Pat. No. 5,960,942, which claimed the benefit of U.S. Provisional Application No. 60/030,086, filed Nov. 5, 1996.
BACKGROUND
1. Field of Invention
This invention relates to pulse tube refrigerators, including pulse tube cryocoolers, more particularly to pulse tube refrigerators having fluidic devices that dynamically resist flow while simultaneously extracting heat.
BACKGROUND
2. Description of Prior Art
Pulse tube refrigerators are a variation on a class of regenerative refrigerators that includes Stirling cycle and Gifford-McMahon refrigerators. Stirling and Gifford-McMahon refrigerators use displacers to move a fluid (usually helium) through their regenerators and reject heat through a single heat exchanger location. Distinguishing characteristics of the pulse tube refrigerator arc that it has no mechanical displacer; that the pulse tube itself is a nearly adiabatic space in which the temperature of the working fluid is stratified; and that it rejects heat through two separate warm heat exchangers (hereinafter referred to as the warm heat exchanger and the aftercooler).
Pulse tube refrigerators operate by compressing and expanding fluid in conjunction with fluid movement through heat exchangers. In the prior art orifice pulse tube refrigerator shown in FIG. 1, an orifice connects the warm end of the pulse tube to a reservoir, allowing some fluid to flow from the pulse tube through a warm heat exchanger into the reservoir when pressure in the pulse tube is higher than the pressure in the reservoir, and to return by the same route when pressure in the pulse tube falls below pressure in the reservoir. Reservoir mean pressure is typically similar to mean pressure in the pulse tube.
The orifice and reservoir serve to control flows at the warm end of the pulse tube so that they are not in phase with flows at the cold end. That is, the flow at the warm end from the pulse tube toward the reservoir occurs at all times when pressure in the pulse tube is higher than pressure in the reservoir. Thus, flow from pulse tube to reservoir continues even after flow into the cold end of the pulse tube has ceased and outflow has begun.
Similarly, when pressure in the reservoir is higher than the pressure in the pulse tube, fluid flows from the reservoir to the pulse tube. That is true not only when fluid is leaving the cold end of the pulse tube and pressure in the pulse tube is falling but also during the first part of the subsequent inflow of fluid at the cold end of the pulse tube until pressure in the pulse tube equals and exceeds the pressure in the reservoir.
Over the cycle in an orifice pulse tube, the flows, in sequence, are as follows:
1. Inflows to the pulse tube at both ends;
2. Continued inflow at the cold end; outflow at the warm end;
3. Outflow at the cold end; continued outflow at the warm end; and
4. Continued outflow at the cold end; inflow at the warm end (after which the cycle repeats).
The effect of the orifice is thus to control phasing of fluid flows in the pulse tube relative to pulse tube pressures, alternately forcing warm, compressed fluid through the warm heat exchanger and expanded, cold fluid through the cold heat exchanger.
Performance of the orifice pulse tube can be improved by connecting the compressor to the warm end of the pulse tube with a bypass as shown in FIG. 2. The bypass transfers some fluid from the compressor directly to the pulse tube, thereby decreasing the amount of fluid that emerges from the cold end of the regenerator into the pulse tube during the part of the cycle in which fluid is being compressed and thereby warmed adiabatically. Similarly, the bypass removes warm fluid from the pulse tube during the portion of the cycle during which fluid is leaving the pulse tube at the cold end. That permits cold fluid to linger longer in the cold end of the pulse tube while it is being cooled adiabatically.
The purpose and effect of an orifice is the same whether or not a bypass is used. The standard prior art orifice used to control flow between pulse tube and reservoir is a small hole or a narrow tube through which the fluid must pass. In laboratory work, the orifice is typically a needle valve that permits the aperture of the orifice to be adjusted, but adjustable valves are not satisfactory for commercial products that must operate unattended. An orifice fashioned by drilling a hole or by installing a capillary tube must be designed and built to very fine tolerances, which is difficult and expensive.
A standard method of removing heat from the warm end of a pulse tube refrigerator is through a stack of copper screens that are packed into the warm end of the pulse tube and brazed to the pulse tube wall. Heat transferred from the working fluid travels along the wires of the screens and into the pulse tube wall, where it is removed. That arrangement is not optimal, particularly in large pulse tubes. Heat has a long distance to travel through the narrow conduction paths of wires to get from the center of the heat exchanger to the pulse tube wall. Moreover, fluid returning to the pulse tube from the reservoir is cooling adiabatically as pressure falls, and its temperature may momentarily fall below the temperature of the warm heat exchanger, causing the screens to function as regenerators, releasing heat back to the fluid. This regenerative effect is unwanted and degrades performance. In any event, heat exchangers of this type require painstaking care in their construction.
Warm heat exchangers made of stacked screens serve a second purpose, which is to straighten and distribute flow into the pulse tube. However, that function is not essential; diffusers also distribute flow, but without the objectionable regenerative characteristics of screens.
SUMMARY OF THE INVENTION
This invention improves upon both the orifice and the warm heat exchanger of orifice pulse tubes and double-inlet pulse tubes by combining their function in fluidic devices that dynamically resist flow while simultaneously extracting heat in an efficient manner from the fluid flowing through them. By eliminating screen-type warm heat exchangers, this invention greatly reduces losses due to regenerative effects in the orifice flow. In effect, this invention uses the work that is otherwise dissipated in the orifice of a pulse tube refrigerator to dynamically enhance heat rejection. Key components of this invention are fluidic devices that combine flow resistance with high capacity for heat transfer. These devices can be easily made to relatively loose tolerances. These devices can be diodes that are directional, so that they provide effects similar to check valves, but with no moving parts. By arranging diodes to force circulation through a loop, regenerative effects can be reduced and fluid returned to the pulse tube can be cooler than it would be in a prior art orifice pulse tube refrigerator, thereby improving performance of the pulse tube refrigerator.
This invention benefits pulse tube refrigerators that employ a pressure wave that varies significantly from sinusoidal. The performance of an orifice pulse tube cryocooler (low temperature refrigerator) can be improved by altering the timing of the pressure wave that compresses and expands the fluid in the pulse tube, allowing a disproportionate amount of time for flow through the warm heat exchanger after the fluid in the pulse tube has been compressed. See G. Thummes, F. Giebeler, C. Heiden, "Effect of Pressure Wave Form on Pulse Tube Refrigerator Performance", Cryocoolers 8, (R. G. Ross, Jr., ed.), Plenum Press 1995, p. 383. However, altering the pressure wave also alters flows through the orifice to the reservoir. A long period of dwell at high pressure increases mean pressure in the reservoir relative to mean pressure in the pulse tube, resulting in non-optimal flow phasing. By employing the fluidic diodes of this invention to make flow from pulse tube to reservoir more difficult than the return flow from reservoir to pulse tube, the adverse effect of high pressure dwell on phasing can be counteracted.
OBJECTS AND ADVANTAGES
Several objects and advantages of this invention are:
(a) To provide a single component that replaces both the orifice and the warm heat exchanger of an orifice pulse tube refrigerator.
(b) To provide a single component that replaces both the orifice and the warm heat exchanger of an orifice pulse tube refrigerator and that causes the refrigerator to operate more efficiently.
(c) To provide a single component that replaces both the orifice and the warm heat exchanger of an orifice pulse tube refrigerator and that causes the refrigerator to reach a lower temperature.
(d) To provide a single component that replaces both the orifice and the warm heat exchanger of an orifice pulse tube refrigerator and that causes the refrigerator to achieve more refrigeration at a specified temperature.
(e) To provide a pumped loop that improves heat rejection at the warm end of an orifice pulse tube refrigerator by reducing regenerative effects of the warm heat exchanger and that causes the refrigerator to operate more efficiently.
(f) To provide a pumped loop that improves heat rejection at the warm end of an orifice pulse tube refrigerator by reducing regenerative effects of the warm heat exchanger and that causes the refrigerator to reach a lower temperature.
(g) To provide a pumped loop that improves heat rejection at the warm end of an orifice pulse tube refrigerator by reducing regenerative effects of the warm heat exchanger and that causes the refrigerator to achieve more refrigeration at a specified temperature.
(h) To provide a less expensive alternative to prior art orifices and warm heat exchangers.
(i) To provide a more rugged and reliable alternative to prior art orifices and warm heat exchangers.
(j) To provide compensation for time of flow in a pulse tube refrigerator employing a pressure wave with high pressure dwell in order to maintain mean reservoir pressure at the level of mean pulse tube pressure.
Other 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 drawing, in which preferred embodiments of the invention are illustrated by way of example. It is to be expressly understood, however, that the drawing is for illustration and description only and is not intended as a definition of the limits of the invention.
Certain terminology and derivations thereof may be used in the following description for convenience in reference only, and will not be limiting. For example, words such as "upward," "downward," "left," and "right" would refer to directions in the drawings to which reference is made unless otherwise stated. Similarly, words such as "inward" and "outward" would refer to directions toward and away from, respectively, the geometric center of a device or area and designated parts thereof. References in the singular tense include the plural, and vice versa, unless otherwise noted.
BRIEF DESCRIPTION OF DRAWINGS
Drawing Figures
FIG. 1 is a schematic view of a prior art orifice-type pulse tube refrigerator.
FIG. 2 is a schematic view of a prior art orifice-type pulse tube refrigerator with a secondary inlet bypass.
FIG. 3 is a schematic perspective view of a prior art vortex diode.
FIG. 4A is a schematic perspective view of a prior art vortex tube.
FIG. 4B is a broken cross sectional representation of a prior art vortex tube equipped with prior art vortex generator.
FIG. 4C is a an orthogonal cross section of the prior art vortex tube and vortex generator of FIG. 4B, taken along line 4C--4C of FIG. 4B.
FIG. 4D is a cross section of a prior art vortex tube equipped with prior art vortex generator with a tangential entrance to annular manifold.
FIG. 5 is a schematic perspective view of a constant-rotation double diode of the present invention.
FIG. 6 is a schematic perspective view of a constant-rotation, reversible flow vortex tube of the present invention.
FIG. 7 is a schematic perspective view of a constant-rotation, reversible flow vortex tube of the present invention equipped with a venturi at the intersection of the cold return duct and main duct.
FIG. 8 is a schematic perspective view of a constant-rotation double vortex tube of the present invention.
FIG. 9 is a schematic perspective view of a constant-rotation double vortex tube of the present invention equipped with vortex diodes in the cold passages.
FIG. 10 is a schematic perspective view of a constant-rotation double vortex tube of the present invention equipped with venturis at the intersections of the cold return ducts and the main ducts.
FIG. 11 is a schematic view of an embodiment of a pulse tube refrigerator of the present invention with a diode loop and a directly-connected reciprocating compressor.
FIG. 12 is a schematic view of an alternate embodiment of a pulse tube refrigerator of the present invention with a constant-rotation double diode and a directly-connected reciprocating compressor.
FIG. 13 is a schematic view of another alternate embodiment of a pulse tube refrigerator of the present invention with a constant-rotation double vortex tube and a directly-connected reciprocating compressor.
FIG. 14 is a schematic view of another alternate embodiment of a pulse tube refrigerator of the present invention with a compressor, accumulators, valves and a fluidic diode.
FIG. 15 is a schematic view of a prior art blind vortex tube showing flow in the direction employed in prior art.
FIG. 16 is a schematic view of another alternate embodiment of the present invention, employing a blind vortex tube.
FIG. 17 is a sectional view of a preferred arrangement of a combination of blind vortex tube and pulse tube of the present invention.
______________________________________Reference Numerals In Drawings______________________________________1-1a orifice pulse tube refrigerator10 pulse tube12 warm fluid14 cold fluid16 plug of stratified fluid20 reservoir22 orifice24 bypass tube26 bypass orifice28 warm heat exchanger30 cold heat exchanger32 regenerator34 aftercooler40 piston-type compressor/expander44 compression/expansion space60 vortex diode62 race64-64c tangential passage66 axial hole70 vortex tube refrigerator72-72c vortex chamber74 hot exhaust port76-76b cold exhaust vent78b-78c vortex generator79b-79c annular manifold82b-82c main duct164 tangential passage168 constant-rotation double diode172 vortex chamber264 tangential passage269 constant-rotation reversible flow vortex tube272 vortex chamber276 cold exhaust vent282 main duct284 cold return duct364 tangential passage369 constant-rotation reversible flow vortex tube372 vortex chamber376 cold exhaust vent382 main duct384 cold return duct390 venturi464 tangential passage472 vortex chamber474 hot exhaust port476 cold exhaust vent480 constant-rotation double vortex tube482 main duct484 cold return duct560 vortex diode564 tangential passage566 axial hole572 vortex chamber574 hot exhaust port576 cold exhaust vent580 constant-rotation double vortex tube582 main duct584 cold return duct664 tangential passage672 vortex chamber674 hot exhaust port676 cold exhaust vent680 constant-rotation double vortex tube682 main duct684 cold return duct690 venturi701 pulse tube refrigerator710 pulse tube718 diffuser720 reservoir728 warm heat exchanger730 cold heat exchanger732 regenerator734 aftercooler740 piston-type compressor/expander744 compression/expansion space752 duct760-760a vortex diode764-764a tangential passage786 diffuser tee787 reservoir tee788 loop801 pulse tube refrigerator810 pulse tube818 diffuser820 reservoir830 cold heat exchanger832 regenerator834 aftercooler840 piston-type compressor/expander864-864a tangential passage868 constant-rotation double diode872 vortex chamber901 pulse tube refrigerator910 pulse tube918 diffuser920 reservoir930 cold heat exchanger932 regenerator934 aftercooler940 piston-type compressor/expander964-964a tangential passage972 vortex chamber976-976a cold exhaust vent980 constant-rotation double vortex tube984-984a cold return duct1001 pulse tube refrigerator1010 pulse tube1018 diffuser1020 reservoir1030 cold heat exchanger1032 regenerator1034 aftercooler1050 compressor1054 high pressure accumulator1056 low pressure accumulator1058 valve1060 vortex diode1101 blind vortex tube1114 cold fluid1164 tangential passage1172 vortex chamber1176 cold exhaust port1190 central core of fluid1192 shell of hot, rotating fluid1194 blind end1196 open end1198 cold throat1201 blind vortex tube1210 pulse tube1215 jet of fluid1216 outer shell of fluid1220 reservoir1264 tangential passage1272 vortex chamber1276 cold exhaust port1294 blind end1296 open end1298 cold throat1301 pulse tube refrigerator cold head1302 connecting tube1303 blind vortex tube1304 warm end housing1306 cooling fins1308 cold end housing1310 pulse tube1311 diffuser nozzle1312 multi-function part1313 cold end1314 warm end1316 transition zone1317 regenerator manifold1320 reservoir1330 cold heat exchanger1332 annular regenerator1334 flow channel1364 connecting tube1372 vortex chamber1376 cold exhaust port1378 vortex generator1379 annular space1398 cold throat______________________________________
It is to be noted that, for convenience, the last two positions of the reference numerals of alternative embodiments of the invention duplicate those of the numerals of the embodiment of FIG. 1, where reference is made to similar or corresponding parts. However, it should not be concluded merely from this numbering convention that similarly numbered parts are equivalents.
DETAILED DESCRIPTION OF THE INVENTION
A prior art orifice pulse tube refrigerator 1 is illustrated schematically in FIG. 1. A piston-type compressor/expander 40 having a compression/expansion space 44 sends an oscillating pressure wave through aftercooler 34, regenerator 32, and cold heat exchanger 30 into a pulse tube 10. The pulse tube 10 communicates with a reservoir 20 through an orifice 22 in its warm end, which may be a hole, a capillary tube or an adjustable valve. Warm fluid 12, typically helium, passes through a warm heat exchanger 28 as it flows back and forth through the orifice 22 between the pulse tube 10 and the reservoir 20. The orifice 22 controls the amount of flow to and from the reservoir 20. At the other end of the pulse tube 10, cold fluid 14 passes back and forth between pulse tube 10 and regenerator 32 through a cold heat exchanger 30. Warm fluid 12 and cold fluid 14 are separated by a plug of stratified fluid 16 that oscillates back and forth in the pulse tube 10 but never leaves it. That plug of stratified fluid 16 contains a strong temperature gradient.
FIG. 2 is a schematic illustration of a prior art orifice pulse tube refrigerator 1a with bypass 24 (sometimes called a "double-inlet pulse tube refrigerator"). It is similar to the prior art orifice pulse tube refrigerator 1 illustrated in FIG. 1 except that the compression/expansion space 44 of the piston-type compressor/expander 40 communicates with the warm end of the pulse tube 10 through a bypass tube 24 containing a bypass orifice 26, which may be a hole, capillary tube, or adjustable valve that limits flow through the bypass tube 24.
FIG. 3 is a schematic perspective illustration of a prior art fluidic vortex diode 60 with its cover removed. The race 62 of the diode is a disk-shaped chamber. The chamber or race 62 has two openings: the axial hole 66 and the tangential passage 64. The tangential passage comprises means for injecting fluid tangentially into the vortex race or chamber (as do other tangential passages discussed below). Fluid can flow through the diode from one opening to the other in either direction, but the vortex diode 60 offers more resistance to flow that enters the race 62 from the tangential passage 64 and exits through the axial hole 66 than to flow that passes through the diode in the opposite direction. More elaborate diodes with multiple tangential passages and carefully sculpted tangential passages and axial holes are equivalent. Other fluidic diodes that resist flow in one direction more strongly than flow in the opposite direction are also equivalent.
FIG. 4A is a schematic, perspective illustration of a prior art vortex tube refrigerator 70, also known as a Ranque vortex tube, a Hilsch tube or a Ranque-Hilsch tube. A vortex chamber 72 has three openings: a tangential passage 64a, one or more hot exhaust ports 74 and a cold exhaust vent 76. In operation, fluid enters the vortex chamber 72 through the tangential passage 64a and exits in two streams. Inside the vortex chamber 72, the fluid that enters through the tangential passage rotates rapidly. The outer portion of the rotating fluid spirals down toward the hot exhaust ports 74, where a stream of warm fluid 12 exits. An inner core of rotating fluid moves from the end of the vortex chamber 72 that is adjacent to the hot exhaust ports 74 upward toward the opposite end of the vortex chamber 72, where a stream of cold fluid 14 exits through the cold exhaust vent 76.
FIGS. 4B and 4C illustrate an alternative and equivalent prior art method of introducing fluid into a vortex chamber 72b. Fluid is introduced through a main duct 82b into an annular manifold 79b from which it passes through multiple tangential passages 64b drilled through a vortex generator ring 78b that is concentric with and which forms the end of the vortex chamber 72b. A stream of cold fluid exits through the cold exhaust vent 76b.
FIG. 4D illustrates an alternative method of arranging the main duct 82c of a prior art annular manifold 79c, which otherwise is similar in construction to the manifolds of FIGS. 4B and 4C. The entrance to the annular manifold 79c from the main duct 82c is tangential. As before, fluid reaches the vortex chamber 72c through tangential passages 64c in the vortex generator 78c.
FIG. 5 is a schematic, perspective illustration of a novel constant-rotation double diode 168 of this invention. The constant-rotation double diode comprises a vortex chamber 172 into which two tangential passages 164 feed fluid alternately from each end. The tangential passages 164 are oriented so that they cause the fluid in the vortex chamber 172 to rotate the same direction regardless of which of the two tangential passages is feeding fluid into the vortex chamber 172. When fluid is entering the vortex chamber 172 through a tangential passage 164 at one end, it is exiting the vortex chamber 172 through the other tangential passage 164 at the other end. In the process of exiting, the rotating fluid must make a sharp reversal in direction, which creates a large pressure drop between the fluid in the vortex chamber 172 and the exiting fluid in the tangential passage 164 through which it exits. A constant-rotation double diode 168 thus acts as a flow impedance or dynamic orifice, resisting flow through it. A constant-rotation double diode also acts as a high capacity heat exchanger by forcing convection between the swirling fluid and the walls of the vortex chamber 172. Thus, warm fluid entering from a pulse tube is rapidly cooled as it spirals through the vortex chamber 172. Heat is removed from the exterior wall of the vortex chamber 172 by known means such as a water jacket (not shown).
FIG. 6 is a schematic perspective view of a novel constant-rotation reversible flow vortex tube 269. It is similar to the constant-rotation double diode 168 of FIG. 5 in that tangential passages 264 at each end are oriented to force fluid in the vortex chamber 272 to rotate in the same direction without regard to which tangential passage 264 the fluid enters the vortex chamber 272 through. The constant-rotation reversible flow vortex tube 269 differs from the constant-rotation double diode 168 shown in FIG. 5 in that it has a cold exhaust vent 276 at one end and a cold return duct 284 that connects to the tangential passage 264 at the junction of the tangential passage 264 and main duct 282 at the opposite end of the vortex chamber 272.
FIG. 7 is a schematic perspective view of another novel constant-rotation reversible flow vortex tube 369, which is of the general type shown in FIG. 6 except that the cold exhaust vent 376 and the cold return duct 384 leading from the vortex chamber 372 are connected to the tangential passage 364 at the junction of that passage and main duct 382 through the suction side of a venturi 390.
FIG. 8 is a schematic illustration of a novel constant-rotation double vortex tube 480 of this invention. A constant-rotation double vortex tube 480 is a double-ended version of a constant-rotation reversible flow vortex tube 269, 369 as shown in FIGS. 6 and 7. In the vortex chamber 472 of the constant-rotation double vortex tube 480, there are two tangential passages 464, one at each end of the vortex chamber 472. The two tangential passages 464 are oriented so that fluid in the vortex chamber 472 will always be driven to rotate in the same direction regardless of which tangential passage 464 fluid enters through. In each instance, fluid entering from a main duct 482 passes through a tangential passage 464 that becomes a hot exhaust port 474 when flow is going the other direction. Fluid that enters the vortex chamber 472 through a tangential passage 464 forces some fluid to leave the vortex chamber, hot, through the hot exhaust port 474 at the opposite end of the vortex chamber 472. The entering fluid also forces fluid to leave the vortex chamber 472, cold, through the cold exhaust vent 476 and its associated cold return duct 484 adjacent to the tangential passage 464 through which fluid is entering the vortex chamber 472.
FIG. 9 and FIG. 10 are schematic perspective views of methods of ensuring that most of the fluid approaching the constant-rotation double vortex tube 580, 680 through a main duct 582, 682 will enter the vortex chamber 572, 672 through a tangential passage 564, 664 (on fluid exit, alternately referred to as the hot exhaust port 574, 674, respectively) rather than by back-flow through a cold return duct 584, 684 and cold vent 576, 676. As shown in FIG. 9, each cold exhaust vent 576 leads to the axial hole 566 of a vortex diode 560. In FIG. 9, each of the vortex diodes 560 is connected to the main duct 582 at the opposite end of the vortex chamber 572 through a cold return duct 584. In FIG. 10, the vortex diodes 560 are replaced by venturis 690 that are placed at the junctions of main ducts 682, tangential passages 664 and cold return ducts 684 at both ends of the vortex chamber 672.
FIG. 11 is a schematic illustration of a new improved pulse tube refrigerator 701 of this invention. A piston-type compressor 740, having compression/expansion space 744, is connected through an aftercooler 734 to a regenerator 732, which is connected to a cold heat exchanger 730 connected to a pulse tube 710. The latter tube is connected to a diffuser 718 connected to a tee 786, to which is attached a loop 788 of other components. Attached to one side (the lower side in FIG. 11) of the diffuser tee 786 is a first vortex diode 760 oriented to allow freer flow from the pulse tube 710 by way of tangential passage 764 to the reservoir 720 than in the opposite direction. Attached to the other (upper) side of the diffuser tee 786 by another tangential passage 764a is a second vortex diode 760a oriented to allow freer flow from the reservoir 720 to the pulse tube 710 than in the opposite direction. The two vortex diodes 760, 760a are connected to each other with a duct 752 in which a reservoir tee 787 branches off to the reservoir 720. A warm heat exchanger 728 may optionally be included between the diffuser 718 and the lower vortex diode 760 that is oriented to favor flow from the pulse tube 710 toward the reservoir 720.
FIG. 12 is a schematic illustration of a novel pulse tube refrigerator 801 of this invention. A piston-type compressor 840 is connected through an aftercooler 834 to a regenerator 832. The regenerator is connected to a cold heat exchanger 830 connected to a pulse tube 810, which is, in turn, connected to a diffuser 818 connected by a first tangential passage 864. The latter passage leads to a constant-rotation double diode 868 having a vortex chamber 872. The vortex chamber is connected by a second tangential passage 864a to a reservoir 820.
FIG. 13 is a schematic illustration of another new pulse tube refrigerator 901 of this invention. A piston-type compressor 940 is connected through an aftercooler 934 to a regenerator 932 connected to a cold heat exchanger 930. The cold heat exchanger 930 is connected to a pulse tube 910 connected to a diffuser 918, which is connected to a constant-rotation double vortex tube 980 connected to a reservoir 920. The diffuser 918 leads to a first tangential passage 964 attached near the upper, or first, end of a vortex chamber 972. Branching off of the first tangential passage is a first cold return duct 984, which leads to a lower cold exhaust vent 976, which, in turn, leads into the axial center of the lower, or second, end of the vortex chamber 972. Due to its location on the second end of the vortex chamber, the lower cold exhaust vent 976 will be referred to as the "second" such vent. A first (upper) cold exhaust vent 976a leads to a second cold return duct 984a, which duct meets a second tangential passage 964a connected to the reservoir 920.
FIGS. 4A, 5, 6, 7, 8, 9, 10, 12, 13, 15 and 16 are schematic, and each greatly exaggerates the diameter of the respective vortex chamber relative to its length. The ratio of length to diameter in vortex chambers of effective devices may be of the order of 20 to 1 or greater.
FIG. 14 is a schematic illustration of another new pulse tube refrigerator 1001 of this invention. A compressor 1050 is connected to a high pressure accumulator 1054 through an aftercooler 1034 and to a low pressure accumulator 1056. The high pressure accumulator 1054 and the low pressure accumulator 1056 are connected to a valve 1058 that can alternately connect the high pressure accumulator 1054 and the low pressure accumulator 1056 to a regenerator 1032 connected to a cold heat exchanger 1030. This exchanger is connected to a pulse tube 1010, connected to a diffuser 1018, connected to a vortex diode 1060, which is connected, in turn, to a reservoir 1020.
Operation--FIGS. 1 to 14
The cooling capacity of a pulse tube refrigerator is expressed in terms of the amount of heat that can be absorbed at the cold heat exchanger. The amount of heat that can be absorbed is directly determined by the amount of heat that is rejected at the warm end of the pulse tube. Effective heat rejection at the warm end is thus a key to good pulse tube performance.
To achieve good heat rejection at the warm end of the pulse tube, the flow of fluid through the orifice must be in proper phase relative to flows into and out of the pulse tube at its cold end. The orifice 22 of an orifice pulse tube refrigerator 1 as shown in FIG. 1 has the primary purpose of adjusting phasing of the flow at the warm end of the pulse tube 10. The bypass 24 of the double-inlet pulse tube refrigerator 1a as shown in FIG. 2 further adjusts phasing by altering the flow and thus the phasing at the cold end of the pulse tube 10.
As noted as background above, the warm heat exchangers of prior art orifice pulse tube refrigerators are commonly stacks of copper screens braised to the pulse tube walls. The wires of the screens do double duty, conducting heat to the pulse tube's walls and acting as flow-straighteners to insure that a uniform front of fluid emerges from the heat exchanger and enters the pulse tube. Although useful as flow distributors, stacked screens are not essential for that purpose. A well-designed diffuser can move fluid into and out of the end of a pulse tube with little loss due to turbulent mixing. Screens have the disadvantage of acting, in part, as regenerators and re-heating fluid that returns to the pulse tube 10 from the reservoir 20 of prior art pulse tube refrigerators shown in FIGS. 1 and 2. Diffusers 718, 818, 918, and 1018 (FIGS. 11-14) have far less regenerative effect.
This invention improves upon both the orifice and the warm heat exchanger of orifice pulse tubes and double-inlet pulse tubes by combining their function in fluidic devices that dynamically resist flow while simultaneously extracting heat from the fluid flowing through them. By eliminating screen-type warm heat exchangers, this invention greatly reduces losses due to regenerative effects in the orifice flow. In effect, this invention uses the work that is otherwise dissipated in the orifice of a pulse tube refrigerator to dynamically enhance heat rejection. Key components of this invention are fluidic devices that combine flow resistance with high capacity for heat transfer.
The prior art vortex diode 60 as shown in FIG. 3 resists flow in one direction more strongly than in the other. That is because, when fluid enters the race 62 from the tangential passage 64, it is forced into a continuous turn as it proceeds around the race. Inertia of the fluid tends to hold the fluid on the outer circumference of the race 62, resisting its movement toward the axial hole 66 where the fluid eventually exits. When flow moves in the opposite direction, however, it enters the race 62 through the axial hole 66 and passes more or less straight and unimpeded out through the tangential passage 64.
The "diodicity" of a vortex diode can be expressed in terms of the relative flow in each direction for a given pressure difference between the entrance and exit points. For a given geometry and pressure difference, diodicity is determined primarily by the specific gravity of the fluid and its viscosity; high specific gravity and low viscosity produce the highest diodicity. Helium, the preferred fluid in cryocoolers, has a very low specific gravity, even when highly compressed. Although its viscosity is likewise low, limited diodicity is attainable with helium in the pressure and pressure-drop regime in which pulse tube refrigerators operate. However, diodicity ratios in the range of 2:1 are readily obtainable with helium in pulse tube applications, and those ratios are sufficient for the purposes of this invention.
The prior art vortex tube refrigerator 70 shown in FIG. 4A, like the prior art vortex diode 60 shown in FIG. 3, injects fluid tangent to the wall of a circular chamber, creating a rapidly-rotating vortex. The vortex tube differs from the vortex diode in using a long vortex chamber 72 in place of a squat race 62 and in having two exits: one or more hot exhaust ports 74, each of which is at the periphery of the vortex chamber 72 and the cold exhaust vent 76, which is axial to the vortex chamber 72 and of smaller diameter. A tangential passage 64a enters the vortex chamber near the cold end and the vortex flow proceeds down the vortex chamber to the warm end where a portion of the flow 12 exits through the hot exhaust ports 74 and the remainder returns in the center of the vortex chamber, exiting as a cold stream 14 through a cold exhaust vent 76. By adjusting the flow at the hot exhaust ports 74, it is possible to control both the flow and the temperature of the fluid passing through the cold exhaust vent 76 in ways known in the vortex tube art.
This invention takes advantage of a vortex tube's capacity to separate a flow of fluid into two streams, one hotter than the incoming stream and the other colder. Since the hot fluid is in the outer layers of the vortex, it readily transfers heat to the walls of the vortex chamber 72 (or 72b, 72c), where that heat can be removed. When the hot and cold streams are recombined, the net energy in the fluid has been reduced and the temperature of the recombined fluid lowered relative to the temperature of a stream that had simply passed through an orifice. The fluid can be supercooled. That is, it can be cooled even though the stream entering through the tangential passage 64a is cooler than the wall of the vortex chamber 72 so long as the warm outer layer of fluid in the vortex chamber 72 is warmer than the wall of the vortex chamber 72.
FIG. 4A shows fluid entering a vortex chamber 72 through a single tangential passage 64a. A more effective method of creating a vortex in the vortex chamber is to introduce fluid into the vortex chamber 72b through several tangential passages fed from an annular manifold 79b as shown in the prior art arrangement illustrated in FIGS. 4B and 4C. That arrangement can be further improved as shown in FIG. 4D by introducing fluid tangentially into the annular manifold through an offset main duct 82c.
As shown in FIG. 4A, the prior art vortex tube refrigerator 70 is a one-way device; a flow continually enters the tangential passage 64, maintaining a continuous vortex in the vortex chamber 72. The arrangement shown in FIG. 4A is not appropriate for reversing flow; the vortex would be disturbed if flow were to periodically reverse, entering the vortex chamber 72 at the hot exhaust ports 74 and the cold exhaust vent 76 while exiting the vortex chamber 72 at the tangential passage 64.
The constant-rotation double diode 168 shown in FIG. 5 maintains constant-rotation of fluid in a vortex chamber 172 despite reversing flow by orienting tangential passages 164 at both ends so that they force rotation in the same direction regardless of which tangential passage fluid enters the vortex chamber 172 through. Although a constant-rotation double diode 168 does not separate a stream of cold fluid from a stream of warm fluid, it does act as a simple, effective impedance and heat exchanger.
The constant-rotation reversible-flow vortex tube 269 shown in FIG. 6 also maintains constant-rotation of fluid in a vortex chamber 272 as in the constant-rotation double diode 168 illustrated in FIG. 5. However, a constant-rotation reversible-flow vortex tube 269 also separates the flow in one direction into two streams, one hot and one cold. When flow enters the vortex chamber through the tangential passage 264 adjacent to the cold exhaust vent 276, the cold stream through cold return duct 284 combines with a warm stream emerging from vortex chamber 272 through tangential passage 264 at the opposite end as the streams enter main duct 282.
The venturi 390 shown in FIG. 7 serves as means for facilitating fluid flow out of the cold exhaust vent 376 through a cold return duct 384 toward the venturi 390 regardless of which direction fluid is flowing in the tangential passages 364.
The constant-rotation double vortex tube 480 shown in FIG. 8 acts as a vortex tube with flows in both directions. Tangential passages 464 connect with the vortex chamber 472 at both ends, oriented so that flow through each tangential passage 464 forces rotation in the same direction. In both directions of flow in the main ducts 482, a cold stream is tapped off from the center of the vortex and combined with a warm stream in main duct 482, downstream from the vortex chamber 472.
In the embodiment of the constant-rotation double vortex tube 580 shown in FIG. 9, cold exhaust 576 at each end of the vortex chamber 572 is connected to a vortex diode 560, arranged so that fluid flows easily from the vortex chamber 572 through the vortex diode 560 to a cold return duct 584, but only enters vortex chamber 572 through a cold exhaust vent 576 with difficulty. Like the venturi 390 of the device of FIG. 7, the vortex diodes 560 comprise means for facilitating fluid flow out the cold exhaust vents 576 through cold return ducts 584 toward the main ducts 582 regardless of which direction fluid is flowing in the tangential passages 564.
In the embodiment shown in FIG. 10, fluid enters the constant-rotation double vortex tube 680 alternately through each of the main ducts 682, and exits from the other. The entering flow goes into the vortex chamber 672 through a tangential passage 664 rather than through a cold exhaust vent 676 because a venturi 690, comprising another form of fluid flow direction-facilitating means, at the confluence of the main duct 682, tangential passage 664 and cold return duct 684 constantly draws fluid through the cold return duct 684 toward the venturi 690 regardless of the direction of flow in the main ducts 682. When flows in the main ducts 682 reverse, all of the flows in the various passages and ducts of the constant-rotation vortex tube 680 also reverse, excepting only the direction of rotation of flow inside the vortex chamber 672, and the flows in the cold return ducts 684, which remain the same.
In each direction of flow in a constant-rotation double vortex tube 480, 580, 680, the separation of an outer layer of hot fluid from a core of cold fluid rotating inside the respective vortex chamber permits heat to be transferred from fluid to the inner wall of the vortex chamber and rejected from the outer wall of the vortex chamber to a suitable heat sink. The rapidly-rotating vortices in both vortex diodes and vortex tubes generate forced convection that makes these devices extremely efficient heat exchangers.
In addition to its function as a heat exchanger, a constant-rotation double vortex tube 480, 580, 680 illustrated in FIGS. 8, 9 and 10, respectively, offers substantial resistance to fluid flow between one main duct 482, 582, 682 and the other. By proper sizing of the constant-rotation double vortex tube, it can be made to provide an optimal degree of flow restriction between a pulse tube and an associated reservoir. It can thus serve the function of both orifice and warm heat exchanger, performing the combined functions more efficiently than they are performed by separate components in prior art pulse tube refrigerators.
FIG. 11 illustrates a method of incorporating vortex diodes into a pulse tube refrigerator to serve both as heat exchangers and as a flow impedance that replaces an orifice. Two vortex diodes 760, 760a are incorporated in a loop 788 connected to a diffuser 718 at the warm end of a pulse tube 710. One vortex diode 760 is oriented to favor flow away from the pulse tube 710, and the other vortex diode 760a is oriented to favor flow back to the pulse tube 710. The loop 788 is connected through a tee 787 to a reservoir 720, which could also be made integral with loop 788. Optionally, a warm heat exchanger 728 (not shown) may be placed between the diffuser and the vortex diode that favors flow away from the pulse tube 710. In operation, both vortex diodes 760, 760a resist flow in both directions, but their diodicity pumps some fluid around the loop 788, permitting the vortex diode that receives the major flow from the pulse tube 710 to trap some hot fluid in the loop, where its heat can be rejected. As a result, the diode that favors flow returning to the pulse tube 710 remains cooler, and regenerative effects are minimized. Although the diode arrangement is shown in FIG. 11 in conjunction with a piston-type compressor 740 it can also be used with other types of compressors.
FIG. 12 illustrates a preferred embodiment of the invention using the constant-rotation double diode 168 as shown in FIG. 5. A constant-rotation double diode 868 of appropriate flow resistance is interposed between a diffuser 818 and reservoir 820 of a pulse tube refrigerator 801, simultaneously serving the functions of both an orifice and a warm heat exchanger. Note that fluid is tangentially injected into the vortex chamber 872 through the tangential passage 864 when fluid is flowing from the pulse tube 810 to the reservoir 820. Fluid also is tangentially injected into the vortex chamber 872 when fluid is flowing from the reservoir 820 to the pulse tube 810--in this case through the tangential passage 864a. Other applications of fluidic devices to pulse tube refrigerators could involve injecting fluid tangentially into the vortex chamber only in one direction of overall flow or the other.
FIG. 13 illustrates a preferred embodiment of the invention using a constant-rotation double vortex tube 480 as shown in FIG. 8. A constant-rotation double vortex tube 980 designed for appropriate flow resistance is interposed between the diffuser 918 and reservoir 920 of an orifice pulse tube refrigerator 901, simultaneously serving the functions of both an orifice and a warm heat exchanger. In the orifice pulse tube refrigerator 901, constant-rotation double vortex tubes 580, 680 as shown in FIGS. 9 and 10 may also be substituted for the version shown in FIG. 8 and FIG. 13.
FIG. 14 illustrates a preferred embodiment of the invention using a vortex diode 1060 in conjunction with a compressor 1050 with high pressure accumulator 1054, low pressure accumulator 1056 and valve 1058. With this arrangement, it is possible to create an asymmetrical pressure wave in the pulse tube that results in a long flow of hot, high pressure fluid from pulse tube 1010 to reservoir 1020 and a short return flow of lower pressure fluid from reservoir 1020 to pulse tube 1010 by methods known to the art. If an ordinary orifice is used between the pulse tube 1010 and reservoir 1020, the effect is to pump up pressure in the reservoir 1020 during the long period of inflow. The short period of outflow does not return pressure in the reservoir 1020 to its original level, and the mean pressure in the reservoir 1020 remains higher than the mean pressure in the pulse tube 1010, which adversely affects phasing of flows. By substituting a vortex diode 1060 for the orifice, flow from pulse tube 1010 to reservoir 1020 may be more strongly resisted than flow from reservoir 1020 back to pulse tube 1010. In that way, the mean pressure in the reservoir 1020 may be equalized with the mean pressure in the pulse tube 1010 and optimal phasing may be maintained. Again in this configuration, the vortex diode 1060 may serve the function of both orifice and warm heat exchanger.
FIG. 15 is a schematic illustration of a blind vortex tube 1101 of prior art. As in the prior art vortex tube shown in FIGS. 4A, 4B, 4C and 4D, fluid enters vortex chamber 1172 through tangential passage 1164, forcing it into a spiral motion inside vortex chamber 1172. Unlike vortex tube 70 shown in FIG. 4A, blind vortex tube 1101 shown in FIG. 15 has no hot exhaust port 74 as shown in FIG. 4A. Instead, all of the flow that enters vortex chamber 1172 of blind vortex tube 1101 as shown in FIG. 15 exits through cold exhaust port 1176. In operation, the inertia of fluid entering vortex chamber 1172 of blind vortex tube 1101 through tangential passage 1164 holds that fluid against the wall of vortex chamber 1172 and prevents it from immediately exiting through cold exhaust port 1176. Instead, the fluid entering vortex chamber 1172 spirals toward blind end 1194 of vortex chamber 1172, losing some of its rotational velocity by means of friction with the wall of vortex chamber 1172. The friction heats the wall of vortex chamber 1172. As rotational speed of the fluid decreases, the inertial force pressing outer shell of hot, rotating fluid 1192 against the wall of vortex chamber 1172 likewise decreases and fluid begins to move toward the axis of vortex chamber 1172. Starting near blind end 1194 of vortex chamber 1172, a central core of fluid 1190 moves toward cold exhaust port 1176 in a stream that passes through the center of outer shell of hot, rotating fluid 1192. During that passage, hot molecules of fluid are stripped from central core of fluid 1190, making outer shell of hot, rotating fluid 1 192 hotter and central core of fluid 1190 colder. If the fluid is helium, and if heat deposited by outer shell of hot, rotating fluid 1192 is continually removed from the wall of vortex chamber 1172, cold fluid 1114 emerging from cold exhaust port 1176 will be colder than the wall of vortex chamber 1172 and colder than the fluid first entering vortex chamber 1172 through tangential passage 1164.
FIG. 16 illustrates schematically how a prior art blind vortex tube of FIG. 15 can be connected between pulse tube 10 and reservoir 20 of prior art orifice pulse tube refrigerator of FIG. 1 in a novel way to serve as both heat exchanger and flow impedance. Cold throat 1298 in FIG. 16 is a diffuser nozzle that merges into the warm end of a pulse tube (not shown). In operation, flow through cold exhaust port 1276 reverses cyclically, with an equal mass of fluid passing through in each direction during each cycle. The direction of flow illustrated in FIG. 16 is the opposite of the direction of flow that causes blind vortex tube 1101 of FIG. 15 to function as normally intended. For any other purpose for which a blind vortex tube might be used, it would not make sense to operate a blind vortex tube with flow as shown in FIG. 16. However, in the special case of a pulse tube refrigerator, both the direction of flow shown in FIG. 15 and the direction of flow shown in FIG. 16 are advantageous. When flow is as shown in FIG. 16, fluid entering vortex chamber 1272 is hot. That is because flow in that direction occurs only when fluid in the pulse tube has been compressed to a pressure above that of the reservoir, causing its temperature to rise. As shown in FIG. 16, the tapering wall of cold throat 1298 constricts the flow as it moves from pulse tube 1210 toward cold exhaust port 1276, increasing the velocity of that flow and creating a jet of fluid 1215 that moves toward blind end 1294 of vortex chamber 1272. As jet of fluid 1215 moves toward blind end 1294 of vortex chamber 1272, it widens, losing energy and reversing direction to return toward open end 1296 of vortex chamber 1272, where it passes to reservoir 1220 through tangential passage 1264. In the direction of flow shown in FIG. 16, jet of fluid 1215 entering vortex chamber 1272 is warmer than the wall of vortex chamber 1272, and outer shell of fluid 1216 flowing along the wall of vortex chamber 1272 rejects heat to that wall.
When flow in blind vortex tube 1201 of FIG. 16 reverses, and fluid enters vortex chamber 1272 through tangential passage 1264 as shown in FIG. 15, that fluid is close to the temperature of the wall of vortex chamber 1272. Pressure in the reservoir of an orifice pulse tube cooler typically varies little over a cycle, and the temperature of the fluid in the reservoir is not significantly affected by pressure changes. However, once fluid enters vortex chamber 1272 through tangential passage 1264, blind vortex tube operates in the usual manner and the portion of the fluid flow in close contact with the wall of vortex chamber 1272 becomes hot and rejects heat to that wall, as described above.
Thus, the surprising effect is that a single blind vortex tube, with its cold exhaust port connected to the pulse tube of an orifice pulse tube cooler and its tangential passage connected to a reservoir, works effectively as a heat-rejecting heat exchanger with flow in both directions, and can deliver fluid to the pulse tube at a temperature below that of the heat sink (i.e. below the temperature of the wall of the vortex chamber), which no ordinary heat exchanger can do.
FIG. 17 is a sectional view of a preferred arrangement of pulse tube refrigerator cold head 1301 combining a blind vortex tube and a pulse tube in accordance with the present invention. In the arrangement shown in FIG. 17, warm end housing 1304 is sealed or bonded to cold end housing 1308. Warn end housing 1304 has cooling fins 1306 to reject heat. Cold end housing 1308 is a thin-walled tube fashioned from material with low thermal conductivity. Cold heat exchanger 1330 absorbs heat through the wall of cold end housing 1308. Pulse tube 1310 and annular regenerator 1332 are coaxial, with annular regenerator 1332 surrounding pulse tube 1310, thus putting cold heat exchanger 1330 at a more convenient location than cold heat exchanger 30 shown in FIG. 1. Blind vortex tube 1303 and pulse tube 1310 are neatly integrated as shown in FIG. 17, with the same multi-function part 1312 functioning as diffuser/nozzle for the pulse tube and as cold throat 1398 for the vortex tube and incorporating vortex generator 1379. Vortex chamber 1372 is a drilled or molded cavity in warm end housing 1304, which is fabricated from a material with good heat conducting properties, such as aluminum. Flow between a compressor (not shown) and regenerator 1332 is distributed by regenerator manifold 1317, which connects to the compressor through several evenly-spaced flow channels 1334, of which just one is shown. Those flow channels are drilled or cast in warm end housing 1304.
In operation of the preferred embodiment cold head 1301 shown in FIG. 17, when pressure in the compressor is high, fluid flows through flow channels 1334 into regenerator manifold 1317 into annular regenerator 1332, forcing fluid in the cold end of annular regenerator 1332 through cold heat exchanger 1330 into diffuser nozzle 1311 which is integral with pulse tube 1310. Fluid entering cold end 1313 of pulse tube 1310 forces fluid in pulse tube 1310 toward warm end 1314, where fluid is forced through cold throat 1398, which injects fluid through cold port 1376 into vortex chamber 1372 in a jet, as shown in FIG. 16. That flow, in turn, forces fluid out through vortex generator 1378 into annular space 1379 from which it flows through connecting tube 1364 to a reservoir 1320 (illustrated schematically).
In operation of the preferred embodiment shown in FIG. 17, when pressure in the compressor is low, fluid flows from the reservoir 1320 through connecting tube 1364 to annular space 1379 where it enters vortex chamber 1372 through vortex generator 1378. Fluid entering vortex chamber 1372 behaves as shown in FIG. 15, passing through diffuser nozzle 1398 into warm end 1314 of pulse tube 1310. Fluid entering warm end 1314 of pulse tube 1310 forces cold fluid out of cold end 1313 of pulse tube 1310 into cold heat exchanger 1330, and into the cold end of annular regenerator 1332. Fluid entering annular regenerator 1332 from cold heat exchanger 1330 forces fluid out of the other end of annular regenerator 1332, through regenerator manifold 1317 and into flow channels 1334 by which fluid is returned to the compressor.
Cold heads embodying the arrangement of FIG. 17 can be proportioned for use with either a high-speed Stirling compressor or G-M compressor equipped with a suitable low-speed valve. The arrangement shown in FIG. 17 does not preclude use of a prior art "inertance tube" (not shown) connected between the cold head and the reservoir 1320. Neither does it preclude use of a bypass as shown in the double inlet pulse tube refrigerator illustrated in FIG. 2.
Although coaxial pulse tube coolers are known in prior art, typical arrangements connect a reservoir to the warm end of the pulse tube along the axial centerline. In that arrangement, warm fluid enters an annular space from the side and is distributed unevenly around the pulse tube to the warm end of an annular regenerator. In the arrangement shown in FIG. 17, flow to and from vortex generator 1378 is normal to the axis of pulse tube 1310; flow from pulse tube 1310 to the reservoir changes direction 90 degrees at vortex generator 1378, allowing the compressor to connect through connecting tube 1302 to warm end housing 1304 on its axial centerline. Regenerator manifold 1317 is connected to the compressor through several, evenly-spaced, flow channels 1334 cut through the warm end housing 1304. Thus, flow between regenerator 1332 and the compressor can be axial without conflicting with flow at the warm end of the pulse tube. By dividing flow between several flow passages 1334, evenly spaced and diverging radially, the regenerator manifold 1317 can be supplied with equal, symmetrical flow. Even flow distribution in the annular regenerator is essential for good regenerator performance, which is, in turn, critical for good system performance.
Vortex diodes behave much like electrical resistors; they may be arranged either in series or in parallel. In all cases where a vortex diode is called for, multiple diodes may be used. To increase flow resistance, diodes may be stacked in series with the axial hole of the first diode connected to the tangential passage of the next, and so on. To decrease flow resistance, vortex diodes may be arranged in parallel by connecting the tangential passages of several diodes to the same fluid source and the axial holes of each to the same outlet.
Ramifications and Scope
The advantages of the pulse tube refrigerator itself are well known. The present invention improves the thermodynamic performance of orifice pulse tube refrigerators, including double-inlet pulse tube refrigerators, by improving direct heat transfer at the warm end of the pulse tube and reducing regenerative heat transfer in the warm heat exchanger. This invention also improves the performance of pulse tube refrigerators with pressure waves that dwell at high pressure by maintaining the optimal relationship between mean pressure in the pulse tube and mean pressure in the reservoir.
The above disclosure is sufficient to enable one of ordinary skill in the art to practice the invention, and provides the best mode of practicing the invention presently contemplated by the inventor. Although the description above contains many specificities, these should not be construed as limiting the scope of the invention but merely as providing illustrations of some of the presently preferred embodiments of this invention. For example, although some of the drawings show a piston-type compressor/expander as the compressor, any other type of compressor or compressor and valve arrangement that can generate a pressure wave is equivalent, including thermal acoustic devices known to the pulse tube refrigerator art. Although many of the drawings show as a tangential passage a tube that intersects the wall of a vortex chamber, vortex generators such as are illustrated in FIGS. 4B, 4C and 4D are equivalent. Other types of fluidic diodes are equivalent to vortex diodes. Tesla's diode, considered to be the first true fluidic device, described in U.S. Pat. No. 1,329,559 is an example.
Thus, the scope of the invention should be determined by the appended claims and their legal equivalents, rather than by the examples given.
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Fluidic devices, including blind vortex tubes, constant-rotation double diodes and constant-rotation double vortex tubes, are disclosed with which to construct pulse tube refrigerators, including ones having diode loops, constant-rotation double diodes, constant-rotation double vortex tubes, and asymmetrical diode stacks. Present orifice pulse tube refrigerators use an orifice connected at the warm end of the pulse tube to a reservoir. The orifice and reservoir serve to control flows at the warm end of the pulse tube so that they are not in phase with flows at the cold end. Present heat exchangers at the warm end suffer inefficiencies due to heat-regenerative effects caused by return flows through the orifice. The fluidic devices disclosed herein create dynamic replacement orifices for pulse tube refrigerators that also serve as efficient heat exchangers and supercoolers with minimal regenerative characteristics.
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RELATED APPLICATION
This application claims the benefit of U.S. Provisional Application No. 60/695,233, filed on Jun. 29, 2005, the entire teachings of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
Many abrasive products include abrasive particles in a binder, for example, abrasive particles bound to paper in sandpaper, or a bonded abrasive article such as a grinding wheel, formed of abrasive particles and a binder.
Desirable characteristics for such binders include binding strength, toughness, flexibility, ease of curing, ease of additive incorporation such as colorants, minimal cost, and the like. Abrasive binders having one or more such characteristics can exhibit longer abrading lifetime, better abrading performance, decreased random scratch formation on a workpiece due to particle movement, and the like.
Numerous binders have been employed or attempted in abrasive products, for example, phenolic resins, aminoplast resins having pendant α, β-unsaturated carbonyl groups, urethane resins, epoxy resins, urea-formaldehyde resins, isocyanurate resins, melamine-formaldehyde resins, acrylate resins, acrylated isocyanurate resins, acrylated urethane resins, acrylated epoxy resins, bismaleimide resins, hide glue, cellulosics, latices, casein, soy proteins, sodium alginate, polyvinyl alcohol, polyvinylacetate, polyacrylester, and polyethylene vinylacetate, polystyrene-butadiene, mixtures thereof, and the like.
However, there is still a need in the art for abrasive binders with improved properties.
SUMMARY OF THE INVENTION
It is now found that polythiol additives provide improved properties for abrasive resin binders.
An abrasive product includes a plurality of abrasive particles and a resin cured with a polythiol group.
A method of preparing the abrasive product includes contacting the plurality of abrasive particles with a curable composition that includes a resin and a polythiol group, and curing the curable composition to produce the abrasive product.
A method of abrading a work surface includes applying an abrasive product to a work surface in an abrading motion to remove a portion of the work surface. The abrasive product includes an abrasive material embedded in a crosslinked resin, the crosslinked resin including crosslinks by a polythiol crosslinking group.
A formaldehyde resin is crosslinked by the polythiol group.
A curable composition includes the formaldehyde resin and the polythiol crosslinker.
A method of crosslinking the formaldehyde resin includes reacting the polythiol crosslinker with the formaldehyde resin.
In particular embodiments, a crosslinked resin is selected from phenol-formaldehyde, melamine-formaldehyde, and urea-formaldehyde, the resin crosslinked by a polythiol group having at least three thiol moieties, the polythiol group being at least about 1% of the crosslinked resin by weight, wherein compared to the same resin without the polythiol group, the crosslinked resin satisfies at least one criterion selected from the group consisting of the crosslinked resin has increased transparency, the crosslinked resin has an increased storage modulus, the crosslinked resin has an increased loss modulus, and the crosslinked resin has a decreased tan δIn particular embodiments, an abrasive product comprises abrasive particles embedded in this resin.
The disclosed cured resins, such as crosslinked resins, are color stable compared to other resins. For example, the typical darkening observed in phenolic resins can be mitigated with polythiol crosslinking, without the use of melamine, allowing transparent resins capable of being used in applications that benefit from transparency, for example, use with colorants, or the like.
The disclosed resins have improved mechanical properties, for example, increased average storage modulus, increased average loss modulus decreased average tan δ, and the like. The improved mechanical properties can lead to improved applications such as in abrasive products. For example, in coated abrasives such as sandpaper, the disclosed resins can result in a product that retains abrasive grains better leading to decreased random scratch formation, is more flexible leading to less cracking/embrittlement which can improve the lifetime and performance of the product, or can sustain a greater normal cutting force for the same lifetime, and the like.
In addition, the use of disclosed cured resins, such as crosslinked resins, can significantly improve a coated abrasive's flexibility while simultaneously improving the interfacial adhesion, for example, between the make and backing layer.
Without wishing to be bound by theory, it is believed that the polythiol can improve the properties of the cured resins, such as crosslinked resins, in several ways. The polythiol is believed to act as a chain transfer agent, which can slow down high polymerization rates of resins when reacted with the polythiol. Curing of some resins without the polythiol is believed to proceed immediately, or nearly so, to high-molecular weight, “vitrified” polymers that can have poor conversion percentages and poor mechanical properties. The polythiol is believed to result in higher percent conversion of some resin monomers, resulting in intermolecular chain extension, avoiding some of the vitrification effects and leading to better properties. Also, it is believed that rotational freedom around the —S— moiety can relieve stress around abrasive grains, which can improve mechanical properties.
BRIEF DESCRIPTION OF THE DRAWINGS
The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee.
FIG. 1 is a diagram of a coated abrasive product 100 that includes a support substrate 102 , such as sandpaper, emery cloth, or the like.
FIG. 2 is a photograph showing samples of phenolic resin with 0%, 5%, 10%, and 20% by weight of the polythiol pentaerythritol tetra-(3-mercaptopropionate).
FIGS. 3A and 3B shows two otherwise identical coated abrasives containing a fluorescent orange dye. FIG. 3A contains a phenolic resin binder with no polythiol crosslinker. FIG. 3B contains the phenolic resin binder crosslinked with 10% by weight of the polythiol pentaerythritol tetra-(3-mercaptopropionate).
FIG. 4 shows a “grain shadowing” effect which is believed to occur during ultraviolet curing of coated abrasive 100 .
FIG. 5 is a graph of the ultraviolet absorbance of a long wavelength photoinitiator of the invention 500 , a short-wavelength initiator 502 , and three different abrasive grains 504 , 506 , and 508 .
FIGS. 6A , 6 B, and 6 C, respectively, show improved mechanical properties of increased average storage modulus, increased average loss modulus, and decreased average tan δ measured over a temperature range of −150 degrees C. to 250 degrees C. for a trimethylolpropane triacrylate/tris (2-hydroxy ethyl)isocyanurate triacrylate resin crosslinked with the polythiol pentaerythritol tetra-(3-mercaptopropionate) compared to the same trimethylolpropane triacrylate/tris (2-hydroxy ethyl)isocyanurate triacrylate resin without polythiol.
FIG. 7 is a photograph showing an undesirable random scratch in a workpiece finish.
FIGS. 8A and 8B are photographs that show the difference in surface finish of a workpiece between a coated abrasive with 70/30 ratio of trimethylolpropane triacrylate/tris (2-hydroxy ethyl) isocyanurate triacrylate (TMPTA/ICTA resin) crosslinked with the polythiol pentaerythritol tetra-(3-mercaptopropionate) ( 8 A) compared to an abrasive having the same resin without polythiol ( 8 B).
FIGS. 9A and 9B are photographs of coated abrasives after identical use conditions. FIG. 9A is a photograph of a coated abrasive with (TMPTA/ICTA resin) crosslinked with the polythiol pentaerythritol tetra-(3-mercaptopropionate); FIG. 9B a photograph of an abrasive having the same resin without the polythiol.
DETAILED DESCRIPTION OF THE INVENTION
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.
The disclosed embodiments are generally related to polythiol groups in combination with polymers and resins, in particular employed as binders incorporated into abrasive products.
In one aspect, the present invention is directed to an abrasive product that includes a resin cured with a polythiol group. In some embodiments, the cured resin includes a resin crosslinked with the polythiol group.
As used herein, an uncured or uncrosslinked “resin” is a composition for curing or crosslinking comprising one or more components selected from monomers, oligomers, and polymers, and may optionally contain other additives such as colorants, stabilizers, plasticizers, fillers, solvents, antiloading agents, or the like. Generally, a resin includes a mixture of partially polymerized components that harden upon curing, which is typically the result of a crosslinking reaction. The cured or uncrosslinked resin can be cured by initiation with light, electron beam radiation, acid, base, heat, combinations thereof, or the like to form the crosslinked resin. Typically in the invention, the uncured or uncrosslinked resins, such as aldehyde resins, are cured or crosslinked with a polythiol group.
As used herein, a “polythiol crosslinker” or “polythiol group” is an organic moiety and includes at least two thiol (—SH) groups; when crosslinked, the thiols are in the form of a sulfur ether group —S—. Polythiols can be monomers oligomers or polymers having 2, 5, 10, 20, 50, 100 or more thiol groups. Generally, a polythiol group comprises from 2 to 6 thiol groups. In one embodiment, the polythiol group is a non-polymeric organic compound. As used herein, the “non-polymeric ” organic compound means that the organic compound includes either no repeating unit, or not more than 10 repeats (preferably not more than 5 repeats) of a repeating unit which a polymer typically includes. In a specific embodiment, the polythiol group is a trithiol or tetrathiol. In a more specific embodiment, the trithiol or tetrathiol is non-polymeric (i.e., a monomer or an oligomer). In a preferred embodiment, the polythiol group can be selected from trimethylolpropane tri(3-mercaptopropionate), trimethylolpropane tri(2-mercaptoacetate), pentaerythritol tetra(3-mercaptopropionate), pentaerythritol tetra(2-mercaptoacetate), polyol-3-mercaptopropionates, polyol-2-mercaptoacetates, polyester-3-mercaptopropionates, polyester-2-mercaptoacetates, ethoxylated trimethylolpropane tri(3-mercaptopropionate), also known under the trade name ETTMP 1300 (Chemical Abstract Service Registry No. 345352-19-4), other polyolesterthiols, other polyolthiols, or the like. In a more preferred embodiment, the polythiol includes pentaerythritol tetra-(3-mercaptopropionate) C(CH 2 OOCCH 2 CH 2 —SH) 4 ). Numerous polythiols are commercially available from BRUNO BOCK Chemische Fabrik GmbH & Co. KG, Marschacht Germany.
In a specific embodiment, the resin to be cured or crosslinked includes an aldehyde resin, preferably a formaldehyde resin, crosslinked with a polythiol group. As used herein, the uncured or uncrosslinked “aldehyde resin” includes polymeric or partially polymerized compositions that are formed by condensation reactions of an aldehyde with nucleophiles, such as amino compounds or phenolic compounds, generating water as a byproduct. As used herein, the “amino compound” means a monomeric compound having at least one amino group (—NH 2 ). Examples of the amino compounds that can be employed in the invention include urea; aminotriazines such as melamine; and mixtures thereof. As used herein, the “phenolic compound” means a monomeric compound having at least one phenolic unit. Examples of the phenolic compounds that can be employed in the invention include phenol; alkyl phenols, such as cresols (e.g., o-cresol, m-cresol and p-cresol), xylenols (e.g., 2,4-xylenol), cardinols, ethyl phenols, propyl phenols, hexyl phenols, nonyl phenols or cahew nut shell liquid; alkenyl phenols, such as isopropenyl phenol; polyhydric phenols, such as resorcin; aryl phenols, such as phenylphenol; a phenolic diol, such as CH 2 (C 6 H 4 OH) 2 or C(CH 3 ) 2 (C 6 H 4 OH) 2 ; and mixtures thereof. As used herein, the “aldehyde” means an organic compound having at least one aldehyde group or a functional group that can be converted to an aldehyde group, which is capable of reacting with a phenolic compound as described above. Examples of such aldehydes include formaldehyde; formaldehyde yielding materials such as paraformaldehyde; acetaldehyde; furfural; butyraldehyde; and mixtures thereof.
In a more specific embodiment, the resin to be cured or crosslinked includes a phenol-aldehyde, a melamine-aldehyde, a urea-aldehyde resin, or a mixture thereof. In an even more specific embodiment, the resin to be cured or crosslinked includes a phenol-formaldehyde, a melamine-formaldehyde, a urea-formaldehyde resin, or a mixture thereof. In some preferred embodiments, the resin to be cured or crosslinked includes a phenol-formaldehyde resin. Specific examples of such phenol-formaldehyde that can be employed in the invention can be found in the art, for example, in U.S. Pat. Nos. 4,130,550; 4,289,814; and 4,578,425, the entire teachings of which are incorporated herein by reference.
In another specific embodiment, the resin to be cured or crosslinked includes an thiol-ene polymer wherein the thiol-ene polymer is cured or crosslinked with the polythiol group, or in other words the thiol moieties of the thiol-ene polymer include the thiol groups of the polythiol group. In particular embodiments, the resin to be cured or crosslinked includes trimethylolpropane triacrylate or tris (2-hydroxy ethyl) isocyanurate triacrylate.
In yet another embodiment, the resin to be cured or crosslinked includes or is further combined with an optionally crosslinked or crosslinkable component selected from phenolic resins, aminoplast resins having pendant α, β-unsaturated carbonyl groups, urethane resins, epoxy resins, urea-formaldehyde resins, isocyanurate resins, melamine-formaldehyde resins, acrylate resins, acrylated isocyanurate resins, acrylated urethane resins, acrylated epoxy resins, bismaleimide resins, hide glue, cellulosics, latices, casein, soy proteins, sodium alginate, polyvinyl alcohol, polyvinylacetate, polyacrylester, and polyethylene vinylacetate, polystyrene-butadiene, and mixtures thereof.
Generally, the polythiol group can form from at least about 1% to about 99% of the cured or crosslinked resin by weight, typically at least about 5%, more typically from about 5% to about 50%, particularly from about 5% to about 40%, or specifically from about 10% to about 40%.
The abrasive articles of the invention include coated abrasive articles, lapping or structured abrasive articles, bonded abrasive articles, and nonwoven abrasive articles.
In one embodiment, the abrasive articles of the invention are coated abrasive articles. Typically, the coated abrasive articles of the invention include a support substrate having a first major surface and a second major surface; an abrasive material, such as a plurality of abrasive particles; a resin binder which adheres the plurality of abrasive particles to the first major surface of the substrate, and optionally a peripheral coat comprising an antiloading component. The abrasive material, such as abrasive grains, particles or agglomerate thereof, can be present in one layer (e.g., resin-abrasive layer) or in two layers (e.g., make coat and size coat) of the coated abrasive articles. The coated abrasive articles of the invention include a resin binder cured or crosslinked with a polythiol, as described above, in at least one layer selected from the group consisting of binder-abrasive layer, backsize coat, presize coat, make coat, size coat and supersize coat. Such resin binder can generally be formed by curing a resin binder composition that includes an uncrosslinked resin or a partially crosslinked resin, and a polythiol group, as described above.
In some specific embodiments, the coated abrasive articles of the invention include a support substrate having a first major surface and a second major surface; a plurality of abrasive particles; a resin binder which adheres the plurality of abrasive particles to the first major surface of the substrate, which can be termed a make coat. In one example, such a make coat can be formed by impregnating the support substrate with a resin binder without abrasive grains. Optionally, depending upon their specific applications, the coated abrasive products can further include other coats, for example, a size coat, a supersize coat, or the like. In these embodiments, abrasive materials can be applied separately by gravity, electrostatic deposition or in air stream, or as slurry together with the polyurethane adhesive compositions.
In other specific embodiments, the support substrate may be impregnated with a resin-abrasive slurry that includes an abrasive material, such as abrasive particles, and a resin binder, to form a binder-abrasive layer, depending upon the required aggressiveness of the finished coated abrasive tools, as described above.
The suitable support substrates for the coated abrasive articles of the invention include any number of various materials conventionally used as substrates in the manufacture of coated abrasives, such as paper, cloth, film, polymeric foam, fiber, vulcanized fiber, woven and nonwoven materials, metal, wood, plastic, ceramic, or the like, or a combination of two or more of these materials or treated versions thereof. The substrate may also be a laminate of paper/film, cloth/paper, film/cloth, or the like. Substrates can have varying degrees of flexibility, from relatively flexible thin paper, film, cloth, or the like, to relatively rigid metal, ceramic, wood, or the like. The choice of substrate material will depend on the intended application of the abrasive article. The strength of the substrate should be sufficient to resist tearing or other damage in use, and the thickness and smoothness of the substrate should allow achievement of the product thickness and smoothness desired for the intended application.
The substrate in a coated abrasive article may have an optional saturant/size coat, a presize coat and/or a backsize coat. Such coats can be employed to seal the substrate and/or to protect the yam or fibers in the substrate. If the substrate is a cloth material, at least one of these coats may be required. The addition of the presize coat or backsize coat may additionally result in a “smoother” surface on either the front and/or the back side of the substrate.
Additionally, an antistatic material may be included in any of these cloth treatment coats. The addition of an antistatic material can reduce the tendency of the coated abrasive article to accumulate static electricity when sanding wood or wood-like materials. Additional details concerning antistatic substrates and substrate coats (treatments) can be found in, for example, U.S. Pat. Nos. 5,108,463; 5,137,542 (Buchanan, et al.); U.S. Pat. No. 5,328,716 (Buchanan); and U.S. Pat. No. 5,560,753 (Buchanan, et al.).
The substrate may also be a fibrous reinforced thermoplastic, for example, as disclosed in U.S. Pat. No. 5,417,726 (Stout, et al.), or an endless spliceless belt, for example, as disclosed in U.S. Pat. No. 5,573,619 (Benedict, et al.). Likewise, the substrate may be a polymeric substrate having hooking stems projecting therefrom, for example, as disclosed in U.S. Pat. No. 5,505,747 (Chesley, et al.). Similarly, the substrate may be a loop fabric, for example, as described in U.S. Pat. No. 5,565,011 (Follett, et al.).
In some instances, it may be preferred to incorporate a pressure sensitive adhesive onto the back side of the coated abrasive such that the resulting coated abrasive can be secured to a back up pad. Representative examples of pressure sensitive adhesives suitable for this invention include latex crepe, rosin, acrylic polymers and copolymers, including polyacrylate ester, e.g., polybutylacrylate, vinyl ethers, e.g., polyvinyl n-butyl ether, alkyd adhesives, rubber adhesives, e.g., natural rubber, synthetic rubber, chlorinated rubber, and mixtures thereof. A preferred pressure sensitive adhesive is an isooctylacrylate:acrylic acid copolymer.
The coated abrasive can be in the form of a roll of abrasive discs, as described in U.S. Pat. No. 3,849,949 (Steinhauser, et al.). The coated abrasive may be converted into a variety of different shapes and forms such as belts, discs, sheets, tapes, daisies and the like. The belts may contain a splice or a joint, alternatively the belts may be spliceless such as that taught in U.S. Pat. No. 5,573,619 (Benedict, et al.).
Alternatively, the coated abrasive may contain a hook and loop type attachment system to secure the coated abrasive to the back up pad. The loop fabric may be on the back side of the coated abrasive with hooks on the back up pad. Alternatively, the hooks may be on the back side of the coated abrasive with the loops on the back up pad.
A hook and loop type attachment system is further described in U.S. Pat. No. 4,609,581 (Ott), U.S. Pat. No. 5,254,194 (Ott, et al.) and U.S. Pat. No. 5,505,747 (Chesley, et al.). Alternatively, the make coat precursor may be coated directly onto the loop fabric, for example, as disclosed in U.S. Pat. No. 5,565,011 (Follett, et al.).
It is also feasible to adhere the abrasive particles to both a major or working surface and the opposite surface of a substrate. The abrasive particles can be the same or different from one another. In this aspect, the abrasive article is essentially two sided; one side can contain a plurality of abrasive particles which are different from a plurality of abrasive particles on the other side. Alternatively, one side can contain a plurality of abrasive particles having a different particle size than those on the other side. In some instances, this two sided abrasive article can be used in a manner in which both sides of the abrasive article abrade at the same time. For example, in a small area such as a corner, one side of the abrasive article can abrade the top workpiece surface, while the other side can abrade the bottom workpiece surface.
Nonwoven abrasives are included within the scope of the invention. Nonwoven abrasives are described generally in U.S. Pat. No. 2,958,593 (Hoover, et al.) and U.S. Pat. No. 4,991,362 (Heyer, et al.).
Bonded abrasive articles are also within the scope of the invention. A bonded abrasive article typically includes a resin binder which adheres abrasive particles together in the form of a molded product, e.g., a grinding wheel, a sharpening stone, or the like. The bonded abrasive article can consist of the abrasive and the resin cured with the polythiol group, described above, or can optionally be bonded or molded to a support, such as a handle, an axel, a wheel, or the like. Bonded abrasive articles are generally described in U.S. Pat. No. 4,800,685 (Haynes). In accordance with the present invention, an antiloading component is present in a peripheral coating over at least a portion of the resin binder or in the matrix of the bonded abrasive articles.
FIG. 1 is a diagram of a coated abrasive product 100 that includes a support substrate 102 , such as paper. The resin cured with a polythiol group, as described above, can be present in one or more coats or layers such as a make coat 104 , a size coat 106 , a supersize coat 108 at the support substrate 102 , or the like. Typically, the cured resin can bind the abrasive particles 110 at the support substrate to form an abrasive coating at the support substrate. The coated abrasive can optionally include an optional filler 112 .
The substrate 102 can be rigid or flexible, porous or nonporous, and the like. For example, in various embodiments the support substrate can be a lofty, nonwoven web; a rigid substrate; a flexible substrate having a major surface; or the like. In particular embodiments, the support substrate is flexible, and the cured resin substantially conforms to the flexure of the substrate.
In some cases, supersize coat 108 can be deposited with or without a binder. Generally, the function of supersize coat 108 is to place on a surface of coated abrasive materials an additive that provides special characteristics, such as enhanced grinding capability, surface lubrication, anti-static properties or anti-loading properties. Examples of suitable grinding aids are those that include KBF 4 . Examples of suitable lubricants for supersize coat 108 include lithium stearate and sodium laurel sulfate. Examples of suitable anti-static agent include alkali metal sulfonates, tertiary amines and the like. Examples of suitable anti-loading agents include metal salts of fatty acids, for example, zinc stearate, calcium stearate and lithium stearate and the like. Anionic organic surfactants can also be used effective anti-loading agents. A variety of examples of such anionic surfactants and antiloading compositions including such an anionic surfactant are described in U.S. Patent Application Publication No. 2005/0085167 A1, the entire teachings of which are incorporated herein by reference. Other examples of suitable anti-loading agents include inorganic anti-loading agents, such as metal silicates, silicas, metal carbonates and metal sulfates. Examples of such inorganic anti-loading agents can be found in WO 02/062531 and U.S. Pat. No. 6,835,220, the entire teachings of which are incorporated herein by reference.
In particular embodiments, the abrasive product can include an optional compliant energy dispersing layer 114 , which can be between the support substrate 102 and the abrasive coating 104 (as shown) or the support substrate 102 can be between the abrasive coating 104 and compliant energy dispersing layer 114 . In some embodiments, the support substrate can be made of a material that provides both the support substrate function and the compliant energy dispersing function in a single layer, e.g., an elastomeric polymer film, or the like. The compliant energy dispersing layer is believed to at least in part mitigate the effects of abrading action force which is believed to tend to cause the abrasive particles to be released from the cured or crosslinked resin binder. Thus, a product with a compliant energy dispersing layer compared to an otherwise identical product without such a layer can have improved abrasion performance, improved abrasion lifetime, or the like.
The abrasive product can include a colorant, for example, dyes or pigments. Generally, a portion of the colorant can be visible through the cured resin, such as the crosslinked resin, for example, in some embodiments, a portion of the colorant is included in the cured resin, in an optional support substrate, and/or in a coating between the optional support substrate and the cured resin. In particular embodiments, the colorant can include organic polycyclic dyes, organic monoazo dyes, organic diazo dyes, organometal complexes, inorganic pigments such as metal oxides or complexes. Dye can fall into Perinone, anthraquinone, azo dye complexes and thioindigoid.
A fluorescent colorant is a dye or pigment containing a fluorescent organic molecule. Detailed descriptions of fluorescent colorants can be found in Zollinger, H., “Color Chemistry: Synthesis, Properties, and Applications of Organic Dyes and Pigments”, 2 nd Ed., VCH, New York, 1991, the entire teachings of which are incorporated herein by reference. As used herein, a fluorescent colorant can be, for example, a xanthene, thioxanthene, fluorene (e.g., fluoresceins, rhodamines, eosines, phloxines, uranines, succineins, sacchareins, rosamines, and rhodols), napthylamine, naphthylimide, naphtholactam, azalactone, methine, oxazine, thiazine, benzopyran, coumarin, aminoketone, anthraquinone, isoviolanthrone, anthrapyridone, pyranine, pyrazolone, benzothiazene, perylene, or thioindigoid. More preferably, a fluorescent colorant is selected from the group consisting of xanthenes, thioxanthenes, benzopyrans, coumarins, aminoketones, anthraquinones, isoviolanthrones, anthrapyridones, pyranines, pyrazolones, benzothiazenes, thioindigoids and fluorenes. Most preferably, the fluorescent colorant is a thioxanthene or thioxanthene.
One skilled in the art knows that for many commercially available colorants, the specific chemical structure of individual derivatives within a class, e.g., thioxanthene derivatives, may not be publicly available. Thus, specific fluorescent colorants are typically referred to by Colour Index (C.I.) name, as defined in “Colour Index International”, 4 th Ed. American Association of Textile Chemists and Colorists, Research Triangle Park, NC, 2002. The Colour Index is also available online at www.colour-index.org. The entire teachings of the Colour Index are incorporated herein by reference.
Examples of preferred fluorescent colorants include C.I. Solvent Orange 63 (Hostasol Red GG, Hoechst AG, Frankfurt, Germany), C.I. Solvent Yellow 98 (Hostasol Yellow 3G, Hoechst AG, Frankfurt, Germany), and C.I. Solvent Orange 118 (FL Orange SFR, Keystone Aniline Corporation, Chicago, Ill.).
The amount of colorant that can be employed depends on the particulars of the intended use, the characteristics of the colorant, the other components in the composition, and the like. One skilled in the art will know how to judge these details to determine the amount of colorant for a particular use. Typically, the amount of colorant will be a weight fraction of the total colorant composition of between about 0.01 and about 2%, more preferably between about 0.05 and about 0.5%, and most preferably, about 0.2%.
In specific embodiments, the colorant is red, orange, yellow, green, blue, indigo, or violet. In specific embodiments, the colorant is fluorescent, for example, fluorescent red, fluorescent orange (blaze orange), fluorescent yellow, fluorescent green, or the like. In some preferred embodiments, the colorant is fluorescent orange (blaze orange).
In various embodiments, particularly in some embodiments including the presence of a colorant, the cured or crosslinked resin does not include melamine.
In various embodiments, the colorant can be employed to identify the abrasive product, e.g., for commercial branding, for usage indication such as wet, dry, wood, metal, or the like, or for identification of grit size, or the like
In various embodiments, the colorant can be formed as a printed pattern, for example, to show a logo, an identifying description, a part number, a usage instruction, a safety warning, a wear indicator, a swarf loading indicator, or the like. For example, an abrasive loaded with swarf or an abrasive that is worn can be less effective, thus making a wear indicator or swarf loading indicator useful for indicating to a user that a change in abrasive to improve effectiveness. As used herein, “swarf” refers to abraded workpiece material that can “load” or remain in contact with the abrasive, tending to reduce the effectiveness of the abrasive.
In some embodiments, the cured resin can be cured, e.g., crosslinked, by a photoinitiator having, at a wavelength of 350 nm or longer, an absorption value greater than 0.1, generally greater than 0.15, typically greater than 0.2, more typically greater than 0.25, or particularly greater than 0.3.
Typically, the absorption value at a wavelength 350 nm or longer is over a wavelength range of at least about 10 nm, more typically at least about 25 nm, particularly at least about 40 nm, or in specific embodiments about 50 nm. The wavelength range can be located beginning at 350 nm or greater, typically located between 350 nm and 800 nm, more typically between 350 nm and 500 nm, or in some embodiments between 350 nm and 450 nm. In particular embodiments, the wavelength range can be located between 350 nm and 400 nm, typically beginning at 350 nm.
In some embodiments, the cured resin can be cured, e.g., crosslinked, by a photoinitiator selected from bis-acylphosphine oxide and α-hydroxyketone.
In some embodiments, the abrasive product includes abrasive grains that can be, at least in part, transparent to ultraviolet light, e.g., having, at a wavelength of 350 nm or longer, an absorption value less than 0.9, generally less than 0.8, typically less than 0.7, more typically less than 0.6, or particularly less than 0.5. Typically, the absorption value at a wavelength 350 nm or longer is over a wavelength range of at least about 10 nm, more typically at least about 25 nm, particularly at least about 40 nm, or in specific embodiments about 50 nm.
Likewise, in some embodiments, the abrasive product includes a support substrate that can be transparent to ultraviolet light.
Also, in various embodiments, the cured or crosslinked resin and/or the abrasive product can include an ultraviolet transparent filler e.g., a filler that transmits more ultraviolet light than standard opaque fillers such as calcium carbonate and silica. In particular embodiments, the ultraviolet transparent filler is aluminum trihydrate.
In various embodiments, the abrasive products of the invention can have improved properties, particularly in comparison to a product that is otherwise identical.
In some embodiments, the cured resins of the invention, such as the crosslinked resins, transmit more visible light compared to a resin that is otherwise identical but is not cured with a polythiol group. As used herein, “visible light” is the range of wavelengths from about 400 nm to about 800 nm. The transparency of the cured resin can be measured using a standard visible spectrometer on an appropriately prepared standard sample. For example, two samples formed as identically dimensioned thin films can be compared and the respective percent transmittance values measured.
In some embodiments, the cured resins of the invention, such as the crosslinked resins, can have a decreased average tan δ in a temperature range from about −150 degrees C. to 250 degrees C. compared to a resin that is otherwise identical but is not cured with a polythiol group.
In some embodiments, the abrasive products of the invention can exhibit decreased random scratch formation compared to an abrasive product that is otherwise identical except the cured resin, i.e., the product includes an otherwise identical resin but not cured with a polythiol.
In some embodiments, an abrasive product of the invention, including the resin cured with the polythiol group, has increased flexibility, for example by at least about 5% or by at least about 10%, compared to an abrasive product that is otherwise identical except the cured resin, i.e., the product includes an otherwise identical resin but not cured with a polythiol. Flexibility can be measured by suitable methods known in the art, for example, by the use of a Frank Stiffness meter available from Karl Frank in Germany or Gurley Precision Instruments in U.S.A. Typically, flexibility test with such a Frank Stiffness meter measures the amount of force required to bend a sample over a fixed radius to a standard angle, such as between 10 degrees to 60 degrees in 5 degree increments. This can be done in both wrap and weft directions of the sample. The slope of a plot of % force (y-axis) versus angle (x-axis) for each sample yields what is known as the as the “Flex Slope.” The higher the flex slope generally indicates a stiffer product.
In yet some embodiments, in an abrasive product of the invention that includes the resin cured with a polythiol group, such as the resin crosslinked with a polythiol group, the cured resin provides increased interfacial adhesion strength, for example by at least about 5% or by at least about 10%, compared to an otherwise identical resin but not cured with a polythiol. Interfacial adhesion strength (or peel force) can be determined by suitable methods known in the art, for example, through the use of an Instron Tensile tester. For example, in such a test using an Instron Tensile tester, the backing material of a coated abrasive product that includes a make coat including the crosslinked resin is bonded to another member of essentially equal stiffness. The force required to adhesively separate the make coat layer from the backing material is measured. The ratio of the peel force to flex slope is generally a measure of the adhesive strength of the make coat to the backing material, where greater values represented greater adhesion.
The coated abrasive products of the invention can be used for sanding, grinding or polishing various surfaces of, for example, steel and other metals, wood, wood-like laminates, plastics, fiberglass, leather or ceramics.
In another aspect, the present invention includes a curable composition that includes a formaldehyde resin and a polythiol group. Feature and examples, including preferred examples, of the formaldehyde resin and the polythiol group are as described above. In some embodiments, the curable composition further include the thiol-ene polymer described above, wherein the thiol-ene polymer can be cured, such as crosslinked, with the polythiol group. In other embodiments, the curable composition further includes or is further combined with an optionally crosslinked or crosslinkable component selected from phenolic resins, aminoplast resins having pendant α, β-unsaturated carbonyl groups, urethane resins, epoxy resins, urea-formaldehyde resins, isocyanurate resins, melamine-formaldehyde resins, acrylate resins, acrylated isocyanurate resins, acrylated urethane resins, acrylated epoxy resins, bismaleimide resins, hide glue, cellulosics, latices, casein, soy proteins, sodium alginate, polyvinyl alcohol, polyvinylacetate, polyacrylester, and polyethylene vinylacetate, polystyrene-butadiene, and mixtures thereof. Optionally, the curable compositions of the invention can further include colorants, fillers and additives, depending upon their specific applications. Examples of the colorants, fillers and additives are as described above.
The present invention also includes a formaldehyde resin crosslinked by a polythiol group. Feature and examples, including preferred examples, of the formaldehyde resin and the polythiol group are as described above.
EXEMPLIFICATION
Example 1
Preparation of Crosslinked Phenol Resins
Crosslinked resins for the following examples were prepared by combining a standard commercially available (e.g., Oxychem, Borden, Bakelite -Hexion-, Durez and Dynea) phenol formaldehyde resole resin with the polythiol pentaerythritol tetra-(3-mercaptopropionate) as a percent of total weight ranging among 0%, 5%, 10%, and 20% by weight. The mixture was first dried for 2 hours at 200° F. and then cured at 250° F. for 5 hours to cure, for example crosslink, the resin.
Coated abrasives for the following examples were prepared by combining one of the above uncrosslinked resins with epoxy acrylate resin coated at 1.6 lbs ream (23.7 gsm) abrasive grains (P180 grit BFRPL aluminum oxide) and applying to a 5-mil polyethylene terepthalate surface treated film in a continuous coating process. The coated mixture was cured as above to crosslink the resin, thus fixing the abrasive coat to the substrate. Other optional additives were added as noted in particular examples.
Example 2
The Disclosed Crosslinked Phenol Resins Improve Transparency
FIG. 2 is a photograph showing samples of phenolic resin with 0%, 5%, 10%, and 20% by weight of the polythiol pentaerythritol tetra-(3-mercaptopropionate). As can be seen, transparency of samples of phenolic resin with 0%, 5%, 10%, and 20% by weight of the polythiol pentaerythritol tetra-(3-mercaptopropionate) increased with the increase of the percentage of polythiol, suggesting that the percentage of polythiol correlates with increasing transparency. For example, the sample with 0 wt % of the polythiol pentaerythritol tetra-(3-mercaptopropionate) was almost black, while the sample with 20 wt % of the polythiol pentaerythritol tetra-(3-mercaptopropionate) was very bright yellow-orange.
FIGS. 3A and 3B shows two otherwise identical coated abrasives containing a fluorescent orange dye. FIG. 3A contains a phenolic resin binder cured without the polythiol group. FIG. 3B contains the phenolic resin binder cured with 10% by weight of the polythiol pentaerythritol tetra-(3-mercaptopropionate). As can be seen in FIGS. 3A and 3B , the coated abrasive with the phenolic resin binder cured without the polythiol group was much darker than the coated abrasive with the phenolic resin binder cured with the polythiol group.
Example 3
The “Grain Shadowing” Effect is Overcome by the Disclosed Abrasives
Certain resins can be cured with ultraviolet light irradiation when photoinitiators are employed. FIG. 4 shows a “grain shadowing” effect which is believed to occur during ultraviolet curing of coated abrasive 100 . This effect is believed to impair the curing and thus the performance of abrasives bound with such resins. The short-wavelength ultraviolet light 402 can be obscured by abrasive grains 110 , which can shadow portions of the resin in make coat 104 and size coat 106 in region 404 shadowed by the grain, preventing it from curing properly and binding grains 104 to substrate 102 . Without wishing to be bound by theory, in various embodiments, it is believed that the “grain shadowing” effect can be mitigated by employing a photoinitiator which has an absorption in a wavelength region where the abrasive grains are at least partially transparent, employing ultraviolet transparent fillers such as aluminum trihydrate which can increase scattering and/or diffusion of light to reduce shadowing, employing a photoinitiator that has an absorbance at longer wavelength where the longer wavelength light diffuses more readily around the abrasive particles to reduce shadowing, employing ultraviolet transparent substrate in coated abrasives whereby the resin can be cured by ultraviolet light directed at the other side of the substrate from the coating being cured, or the like.
Example 4
The Photoinitiators Employed in the Disclosed Abrasives Absorb Light Transmitted by the Abrasive Grains, Improving Curing
FIG. 5 is a graph of the ultraviolet absorbance of a long wavelength photoinitiator of the invention 500 , a short-wavelength initiator 502 , and three different abrasive grains 504 , 506 , and 508 . As can be seen, if short-wavelength initiator 502 is employed, there can be significant shadowing by the abrasive grains, particularly grain 504 . By employing long wavelength photoinitiator 500 , the system can be irradiated with light in a wavelength region above the major absorbance of the grain, e.g., 350 nanometers for grain 504 , where photoinitiator 500 has greater absorbance than short-wavelength initiator 502 . Also, the abrasive grains can have comparatively lower absorption than in the absorption band of short-wavelength initiator 502 , particularly grain 504 .
Example 5
Thiol Crosslinked Resins Have Improved Mechanical Properties
Samples of cured polymer for mechanical analysis were prepared by mixing a 70/30 ratio of trimethylolpropane triacrylate/tris (2-hydroxy ethyl) isocyanurate triacrylate or TMPTA/ICTA resin (Sartomer 368D, Sartomer, Exton, Pa.) with photoinitiator, aluminum trihydrate filler, pentaerythritol tetra-(3-mercaptopropionate), and then casting films on untreated Mylar followed by ultraviolet curing in a Fusion lab unit (Fusion UV Systems, Inc, Gaithersburg, Md.) containing both a 600 w/inch and 300 w/inch power supply utilizing a “V” and “D” bulbs respectively to cure the samples @30 FPM. The samples were removed from the Mylar film and trimmed and cleaned to provide samples suitable to dynamic mechanical analysis (DMA) testing (˜ 1/16″ thick X ¼″ wide X 1″ long).
A sinusoidal force was applied to the above samples and the resulting sinusoidal deformation was monitored. The ratio of the dynamic stress to the dynamic strain yields the complex modulus, E*, which can be further broken down to yield the storage modulus, E′, and the loss modulus, E″. The storage modulus refers to the ability of a material to store energy and can be related to the stiffness of the material. The loss modulus can represent the heat dissipated by the sample as a result of the material's given molecular motions and can reflect the damping characteristics of the polymer. The ratio of the loss and storage modulus is the value tan δ. Because of the viscoelastic nature of polymers, these viscoelastic properties (E′, E″ and tan δ) can be a function of temperature as well as time.
FIGS. 6A , 6 B, and 6 C, respectively, show improved mechanical properties of increased average storage modulus, increased average loss modulus, and decreased average tan δ measured over a temperature range of −150 degrees C. to 250 degrees C. for a trimethylolpropane triacrylate/tris(2-hydroxy ethyl)isocyanurate triacrylate resin crosslinked with the polythiol pentaerythritol tetra-(3-mercaptopropionate) compared to the same trimethylolpropane triacrylate/tris(2-hydroxy ethyl)isocyanurate triacrylate resin without polythiol.
Example 6
The Disclosed Abrasive Products Have Improved Finishing Properties
FIG. 7 is a photograph showing an undesirable random scratch in a workpiece finish. Without wishing to be bound by theory, it is believed that such random scratches occur due to poor adhesion of abrasive particles resulting from poor mechanical properties of the resin binder.
FIGS. 8A and 8B are photographs that show the difference in surface finish of a workpiece between a coated abrasive with (TMPTA/ICTA resin) crosslinked with the polythiol pentaerythritol tetra-(3-mercaptopropionate) ( 8 A) compared to an abrasive having the same resin without polythiol ( 8 B). As can be seen, the polythiol abrasive appears to have a smoother finish with fewer deep random scratches.
This apparent difference can be quantified. In particular, the polythiol abrasive has improved (reduced) values for surface roughness parameters Ra, Rz, and Rt, as shown in Table 1.
TABLE 1 Abrasive product Ra Rz Rt Polythiol 0.31 2.87 3.95 No polythiol 0.90 4.47 9.22
The surface roughness parameters are measured over an assessment length comprising a straight path taken by a probe (e.g., a mechanical or optical probe) that measures variation in the surface. Ra is the average roughness value over the assessment length on the surface, which describes the average peak height and valley depth or average amplitude of a surface. Rz is an ISO 10 point height parameter, which describes the height difference between the 5 highest peaks and 5 lowest valleys in the assessment length. Rt is a measure of roughness maximum or “topmost roughness” relating the difference between the highest peak and the lowest valley over the entire assessment length.
Example 7
The Disclosed Abrasive Products Have Improved Durability
FIGS. 9A and 9B are photographs of coated abrasives after identical use conditions. FIG. 9A is a photograph of a coated abrasive with (TMPTA/ICTA resin) crosslinked with the polythiol pentaerythritol tetra-(3-mercaptopropionate); FIG. 9B a photograph of an abrasive having the same resin without polythiol. As can be seen, the resin without polythiol is comparatively rougher and more degraded, with many apparently loosened or missing abrasive grains compared to the coated abrasive with polythiol.
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 scope of the invention encompassed by the appended claims. Further, each U.S. patent previously identified above has its teachings incorporated herein.
Example 8
The Disclosed Abrasive Products Have Improved Flexibility and Adhesion
The polythiol modifier (PTM) modified coated abrasive structures were evaluated for flexibility, peel strength and adhesion in this example. Test samples were prepared under the same process conditions, maintaining coat weights constant, while varying the amount of PTM in either the make or size layer from 0 to 10%, as detailed below.
PTM Coated Abrasive Composition and Process
Coated abrasive structures for the flexibility and adhesion tests were produced by coating a continuous web of finished cloth with 24 pounds per ream (330 ft 2 ) of a phenol formaldehyde make formulation which containing 5.70% PTM. All components and corresponding levels are detailed in Table 2. The web with the make coat was then followed by an electrostatic deposition process applying 32 pounds per ream of a BFRPL aluminum oxide grain. This partial structure of make coated web and grain was then dried in an oven for two hours at 80° C. to impart drying and them B-staging of the phenol formaldehyde prepolymer.
TABLE 2 PTM Modified Make Formulation Make Formulation Component Vendor Percentage Filler NYAD Wollast 325 NYCO 34% Wet Witcona 1260 Witco 0.10% Resin, Single Comp 94-908 Durez 57% Nalco 2341 Defoamer Nalco 0.10% PET-3MP (PTM) Bruno Bloc 5.70% Water — 3.10%
The coated abrasive structures were then coated with 13 pounds per ream of a phenol formaldehyde size coat. The detailed composition of the size coat is presented in Table 3. The web was again transported through a drier which had a dry bulb temperature setting of 120° C. for a period of two hours.
TABLE 3 PTM Modified Size Formulation Size Formulation Component Vendor Percentage White Dye E-8046 Acrochem Corp 0.70% Wet Witcona 1260 Witco 0.20% Solmod Tamol 165A Rohm & Haas 0.90% Filler Syn Cryolite Solvay 42.40% Resin Single Comp 94-908 Durez 48.30% Nalco 2341 Defoamer Nalco 0.10% PET-3MP Polythiol (PTM) Bruno Bloc 2.50% Dye Unisperse Black Ciba 0.20% Water 4.80%
The material was then wound onto a core which forms a roll. The roll of coated abrasive product was then placed into a large convection oven to undergo a post curing step in which the oven temperature was 125° C. for 12 hours.
Flexibility, Adhesion and Peel Tests
Flexibility was ascertained using a Frank Stiffness meter available from Karl Frank in Germany. This test measured the amount of force required to bend the sample between 10 degrees to 60 degrees in 5 degree increments. The slope of a plot of % force (y-axis) versus angle (x-axis) for each sample yields what is known as the as the “Flex Slope.” The higher the flex slope generally indicates a stiffer product. Three (3) test sample pieces, each of which was 1″ wide×3″ long, were used.
Peel force was determined through the use of an Instron Tensile tester. For this mechanical property, the coated abrasive web was bonded to another member of equal stiffness through the use of a high strength, two part epoxy adhesive. The force required to adhesively separate the make coat layer from the backing material was measured through a constraint T-peel on an Instron Tensile tester with a cross head speed of 1.00 inch per minute. The ratio of the peel force to flex slope was a measure of the adhesive strength of the make coat to finished cloth coating substrate, where greater values represented greater adhesion.
Data generated from the Frank Stiffness and Instron Peel Tests are presented in Table 4. From this table the average flex slope for 0% PTM sample was 1.26 with an average peel to flex ratio of 21.1. With 5% addition of PTM to the make coat, the flex slope decreased by 11% with a corresponding increase in the peel to flex ration to 23.0 or 10%. Therefore the increase in product flexibility was observed with a corresponding increase in peel adhesion. This was unexpected, because typically the more flexible product possesses lower peel adhesion values. Incremental addition of PTM to the size layer did not significantly affect the flexibility or adhesion properties of the structure. These results indicate that the presence of PTM in the make layer can significantly improve a coated abrasive's flexibility while simultaneously improving the interfacial adhesion between the make and backing layer.
TABLE 4
Effect of PTM on flex slope and peel strength values.
Test #
Flex Slope
Make PTM
Size PTM
Peel
Peel To Flex
1
1.38
0
0
25.91
18.78
2
1.14
0
0
25.72
22.56
3
1.27
0
0
28.21
22.21
4
1.17
10
0
NA
NA
5
1.17
10
0
25.12
21.47
6
1.09
10
0
26.53
24.34
7
1.02
10
5
25.42
24.92
8
1.05
10
5
27.74
26.42
9
1.04
10
5
24.96
24.00
10
1.14
10
10
27.08
23.76
11
1.09
10
10
24.51
22.48
12
1.14
10
10
27.81
24.39
13
1.23
5
0
25.35
20.61
14
1.21
5
0
26.05
21.53
15
1.23
5
0
26.18
21.28
16
1.14
5
5
26.85
23.55
17
1.18
5
5
24.99
21.17
18
1.21
5
5
25.57
21.13
19
1.21
5
10
23.83
19.69
20
1.17
5
10
23.94
20.46
21
1.2
5
10
25.58
21.32
EQUIVALENTS
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 scope of the invention encompassed by the appended claims.
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An abrasive product includes a plurality of abrasive particles and a resin cured with a polythiol group. A method of preparing the abrasive product includes contacting the plurality of abrasive particles with a curable composition that includes a resin and a polythiol group, and curing the curable composition to produce the abrasive product. A method of abrading a work surface includes applying an abrasive product to a work surface in an abrading motion to remove a portion of the work surface. A curable composition includes a formaldehyde resin and a polythiol group. A formaldehyde resin is crosslinked by a polythiol group. A method of crosslinking the formaldehyde resin includes reacting the polythiol group with the formaldehyde resin.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates to multi-link suspension systems for wheeled vehicles. A wheel suspension's function is, primarily, to isolate the vehicle body and its occupants from the road. However, a suspension system must also control the wheel relative to the vehicle body during braking, cornering and acceleration. These two requirements conflict to a certain extent and usually a compromise has to be made between comfort and road-holding.
[0002] One particular problem addressed by the present invention is that of minimizing the twisting forces about the wheel axle that are induced under braking or when a wheel hits a bump in the road surface.
[0003] US 57,658,58 describes a four-link suspension system which aims to provide improved stability over rough terrain. The systems includes an upper arm, front and rear lateral links and a forwardly extending radius rod. The rear lateral link supports a coil spring while a shock absorber is separately supported on the axle housing so that a compression (or expansion) stroke of the shock absorber does not affect “wind-up” forces applied to the axle housing by the coil spring.
[0004] EP-A-1123821 discloses a five-link suspension system which aims to avoid significant longitudinal spring travel in the rubber mounts of the links due to “wind-up” effects during braking. The system comprises three transverse links and two longitudinal links for connecting a wheel carrier to the vehicle body. One longitudinal link extends forwards from the wheel carrier and the other longitudinal link extends rearwards from the wheel carrier. The separation of the wheel centre from the wheel carrier attachment point of the forward longitudinal link (measured in the vertical direction) is greater than the distance from said attachment point to the ground. This ensures a favourable relationship between forces and moments.
[0005] While these known systems might provide reasonable ride and handling characteristics in certain circumstances, they have the disadvantage of taking up a lot of space.
SUMMARY OF THE INVENTION
[0006] In accordance with a first aspect, the present invention provides a suspension system for a wheeled vehicle, said system comprising four links for connecting a wheel carrier to the vehicle, wherein said links comprise an upper arm, two transverse links and a longitudinal link which extends forwardly of the wheel carrier, and characterised in that the distance between the wheel carrier attachment point of the longitudinal link and wheel centre measured in the vertical direction is greater than the distance between said attachment point and the point of contact of the wheel and the ground.
[0007] In accordance with a second aspect, the present invention provides a wheeled vehicle incorporating the suspension system in accordance with the first aspect.
[0008] By adjusting the distances between the longitudinal link's attachment point and wheel centre and this attachment point and the ground, the invention provides the advantage over the known four-link arrangement mentioned above of minimizing unwanted “wind up” movements. That is to say that this characterising feature lessens the torque around the effective centre of rotation of the wheel carrier (hub) under braking forces or when the wheel hits a bump. This feature provides the desirable characteristics of a low recession rate (i.e. a low compliance fore and aft) and a high stiffness at the tyre contact patch.
[0009] Preferably, the upper arm is a transverse upper wishbone, attached to the wheel carrier above wheel centre. The use of an upper wishbone link gives reduced levels of wheel carrier (or hub) rotation compared with that of the five-link design of the known system mentioned above since the axis of rotation of the link is mainly fore and aft rather than mainly lateral. The reduced hub rotation is a benefit for a number of the kinematic and elastokinematic characteristics including toe change with suspension vertical travel.
[0010] The invention gives the added benefit of reducing the overall spacing of the suspension system fore and aft since in the five link system mentioned above, the level of hub rotation is a function of the length of the front and rear links.
[0011] Another benefit of the wishbone link over five-link arrangements is that is there is one less knuckle attachment (mounting point). A further benefit of the wishbone link is that it provides a suitable mounting point for a stabiliser bar and improves anti-squat characteristics.
[0012] Rotational stiffness around the longitudinal link's attachment point to the wheel carrier depends upon the compliance of the wishbone's rearward connection to the vehicle body. Preferably, the bush used at this rearward connection point has a softer rate in the inboard direction than the outboard direction. This ensures high stiffness under braking for good control of the suspension geometry. Bush mouldings having such characteristics are well-known. The closer the wishbone is positioned to wheel centre, in the vertical direction, the stiffer the bush can be made.
[0013] The attachment point of the longitudinal link at the wheel carrier may be in line with wheel centre or forward thereof (measured in a horizontal direction).
[0014] One of the transverse links may be connected to the wheel carrier forward of wheel centre, while the other transverse link is connected to the wheel carrier rearward of wheel centre (measured in a horizontal direction), with both links being lower links, connected to the wheel carrier below wheel centre. Alternatively, both transverse links may be lower links, with one link being connected to the wheel carrier forward of wheel centre and the other link being connected to the wheel carrier substantially in line with wheel centre.
[0015] In further alternative arrangements, one of the transverse links is attached to the wheel carrier forward of and above wheel centre or forward and in line with wheel centre while the other transverse link is attached to the wheel carrier below wheel centre.
[0016] One of the transverse links may be configured to support a coil spring or a coil spring and damper assembly or an air spring unit.
[0017] The improved packaging efficiency of the present invention helps to maximize rear seat occupancy and boot or trunk package space and shape as well as minimizing the impact of the suspension layout on the body structure. Manufacturing costs can also be less.
[0018] While links are referred to herein as either “transverse” or “longitudinal”, it is to be understood that a “transverse” link may have a comparatively small longitudinal component and a “longitudinal” link may have a comparatively small transverse component.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Some embodiments of the invention will now be described, by way of example only, with reference to the drawings of which;
[0020] FIGS. 1 to 4 show four different perspective views of four suspension links forming a rear suspension for a wheeled vehicle in accordance with a first embodiment.
[0021] FIGS. 5 and 6 show two different perspective views of four suspension links forming a rear suspension for a wheeled vehicle in accordance with a second embodiment.
[0022] Axes X, Y and Z indicate the angle of view, with the X direction pointing towards the rear of the vehicle.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0023] Referring to FIGS. 1 to 4 , the rear suspension of this first embodiment comprises an upper transverse wishbone 1 , a transverse toe link 2 , a transverse control link 3 and a lower, forwardly extending longitudinal link 4 . Each of these four links 1 to 4 is mounted between a wheel carrier 5 and the vehicle body or sub-frame (not shown). The wheel carrier 5 is attached to a rear axle 6 of the vehicle.
[0024] As is customary, the wheel carrier is also mounted to the vehicle body by means of some spring-loaded device (not shown) to allow vertical movement of the wheel carrier with respect to the vehicle body.
[0025] The upper wishbone 1 has a single mounting point 7 at one end where it is connected to the wheel carrier 5 , and a pair of mounting points 8 , 9 at its other end for connection to the vehicle body.
[0026] Referring to FIGS. 2 and 3 , the rearward mounting point 9 is provided with a resilient bush 10 which has a comparatively soft spring rate in the inboard direction C and a comparatively stiff spring rate in the outboard direction D.
[0027] The lower, longitudinal link 4 is mounted to the wheel carrier 5 at a position forward of wheel centre and at a distance ‘A’ from wheel centre measured in the vertical direction that is greater than the distance ‘B’ of this mounting position from the point of contact of the wheel (tyre) (denoted by reference numeral 11 in FIG. 4 ) and the ground 12 .
[0028] The transverse toe link 2 is mounted below and rearward of wheel centre.
[0029] The transverse control link 3 is mounted substantially in line with wheel centre.
[0030] Referring now to FIGS. 5 and 6 , a rear suspension for a vehicle comprises an upper arm 13 in the form of a transverse wishbone, a transverse toe link 14 , a transverse control link 15 and a lower, forwardly extending longitudinal link 16 . Each of the four links are arranged so that they may be mounted at one of their ends to a wheel carrier 17 and at their other ends, to the vehicle body or sub-frame (not shown).
[0031] The transverse toe link 14 is a lower link, being connected to the wheel carrier 17 substantially in line with wheel centre. The toe link 14 is further provided with a recess 18 substantially half way along its length for supporting an air spring assembly (not shown).
[0032] The transverse control link 15 is a lower link and connected to the wheel carrier forward of wheel centre.
[0033] A resilient bush 19 is fitted to the rearward mounting point of the wishbone 13 and has a softer spring rate in the inboard direction than in the outboard direction.
[0034] The lower, longitudinal link 16 is mounted to the wheel carrier 17 at a position forward of wheel centre and at a distance from wheel centre measured in the vertical direction that is greater than the distance of this position from the point of contact between the tyre (supported by the wheel carrier 17 ) and the ground.
[0035] Both the above embodiments achieve improved packaging efficiency and minimal twisting forces under braking by virtue of their geometry.
[0036] Although the above embodiments have been described for use as a rear suspension system, they could equally well be applied to a front suspension system.
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A multi-linked suspension arrangement suitable for the rear wheel of a vehicle comprises an upper wishbone, two transverse links, and a forwardly extending lower longitudinal link. The geometry minimises hub rotation during braking while minimizing packaging space and maximising rear seat and boot space.
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BACKGROUND OF THE INVENTION
It is sometimes necessary to apply a relatively long label to the periphery of an article such that the label covers more than one face or side of the article. It is common practice to apply long labels of this type to cylindrical articles using wrap around labeling techniques. A wrap around label applicator is shown, by way of example, in Crankshaw U.S. Pat. No. 4,124,429.
One problem in applying long labels to the peripheral or side wall of an article is in properly orienting the article with respect to the label. If the article and label are slightly angularly misaligned at the leading edge of the label, the trailing portion of the label will be displaced substantially from its desired location on the article. This kind of labeling is even more difficult when the peripheral wall of the article is noncylindrical or irregular in shape.
Crankshaw et al. U.S. Pat. No. 4,201,621 shows a device for accurately orienting irregularly shaped articles with respect to a label applicator. The label applicator applies the label to the article while the article is held in a predetermined orientation. This patented construction functions extremely well; however, as disclosed in the patent, only relatively small labels are applied to a single side or panel of the article to be labeled. Thus, this patent does not disclose how to utilize the article orienting device in a way to permit long labels to be applied to two or more sides or panels of the article.
SUMMARY OF THE INVENTION
This invention provides a label applicator which accurately applies long labels to the peripheral wall of articles. The long labels may cover any number of panels of the article, and the articles to be labeled may have a peripheral wall of cylindrical or noncylindrical configuration. As used herein, a panel of an article to be labeled means a side or face of the peripheral wall.
The label applicator of this invention can advantageously include means for releasably retaining a label at a label retaining station and label dispensing means for dispensing labels onto the label retaining means. To orient the article to be labeled, the label applicator includes a rotatable wheel having a peripheral surface, at least a portion of which is resiliently deformable, and guide means adjacent the peripheral surface of the wheel for urging an article against the peripheral surface to resiliently deform the peripheral surface sufficiently to hold the article in a desired orientation at the label retaining station.
A leading portion of the label on the label retaining means is blown onto the article while the article is held in the desired orientation. A trailing portion of the label remains retained on the label retaining means. Accordingly, movement of the article past the label retaining station pulls the trailing portion of the label from the label retaining means. Means downstream of the label retaining station applies the trailing portion of the label to the article. Preferably, such means rotates the article.
Because the label is to be applied to more than one panel of the article and only one panel can face the label retaining means, only the leading portion of the label is blown onto the article. The trailing portion of the label, which is to be applied to other panels of the article, is first pulled from the label retaining means by movement of the article and applied to the article downstream of the label retaining station.
The label retaining means preferably includes a perforate face and means for releasably retaining the label against the perforate face by differential fluid pressure. The perforate face has a leading portion through which air can be supplied under pressure to blow the leading portion of the label onto the article and a trailing portion for releasably retaining a trailing portion of the label. To prevent blowing portions of the label against the resilient wheel, it is necessary that the air blast be of relatively short duration. However, there is danger that the re-establishment of the vacuum pressure at the leading portion of the face would seal off the perforations within the leading portion of the face, in which event, the label might be so securely coupled to the leading and trailing portions of the face that it would hold the label and the article against movement. To avoid this problem, the leading portion of the face is preferably concave. This spaces the leading portion of the face sufficiently from the leading portion of the label and provides end openings for this space so that the return of vacuum pressure to the leading portion of the face cannot result in label and article retention.
The leading and trailing portions of the perforate face function differently as described above. Although these different functions could be embodied in a single unitary, perforate face, it is preferred to utilize leading and trailing enclosures having leading and trailing perforate face sections, respectively. One advantage of the dual enclosures is that the trailing enclosure can be a standard vacuum box of the type used commonly in other label applicators for label retention. The leading enclosure can be smaller than the trailing enclosure and is the only enclosure which needs to be provided with means for blowing air for label transfer purposes. In a preferred implementation, the leading enclosure is partly received in an opening in the guide means which cooperates with the wheel, and the leading face section is shorter in the general direction of movement of the articles than the trailing face section.
Although the wheel and guide means can be used to orient articles having a peripheral wall of cylindrical or noncylindrical configuration, they are of particular advantage in orienting articles having a peripheral wall of noncylindrical configuration. Accordingly, the wheel and guide can be eliminated, if desired, when cylindrical articles are to be labeled. The other features of this invention are particularly applicable to the multiple panel labeling of articles having a noncylindrical peripheral wall, although these features can also be employed for the labeling of cylindrical articles.
The invention, together with additional features and advantages thereof, may best be understood by reference to the following description taken in connection with the accompanying illustrative drawing.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a fragmentary top plan view of a label applicator constructed in accordance with the teachings of this invention.
FIG. 2 is an exploded isometric view of the leading enclosure.
FIG. 3 is a sectional view of the leading enclosure illustrating how the concave face section thereof is not sealed off by the label.
FIG. 4 is a fragmentary isometric view illustrating the structure of the label applicator adjacent the label applying station.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows a label applicator 11 for applying labels to articles 13 which are moved along a horizontal path past a label retaining station 15 by any suitable means, such as a conveyor 17. Although the label applicator 11 may use various different kinds of label dispensing means, in the embodiment illustrated, labels 19 are releasably adhered to an elongated backing strip or web 21 by a pressure sensitive adhesive. The web 21 is wound on a supply reel 23 and passes over rollers (not shown), peeling bars 25 and 27 to a take-up reel 29. In passing over the peeling bar 27, the web 21 is folded into a reverse bend, and the label 19 is separated from the web. The movement of the web 21 over the peeling bar 27 is controlled in a conventional manner, and the peeling bar 25 is used to contain a portion of the sensing apparatus which controls movement of the backing strip.
The label 19 removed from the web 21 is releasably retained at the label retaining station 15 by label retaining means which, in the embodiment illustrated, includes a trailing enclosure 31 and a leading enclosure 33 suitably mounted along with the supply reel 23, the peeling bars 25 and 27 and the take-up reel 29 on supporting structure 35 of the label applicator. The trailing enclosure 31 is preferably a conventional vacuum box having a trailing perforate face section 37 (FIG. 4).
The leading enclosure 33 may be of various different constructions which can provide it with a leading perforate face section 39 (FIG. 4) having openings 41 which can alternately be supplied with air at vacuum pressure to assist in releasably retaining the label 19 or air under a positive pressure for transferring a leading portion 43 of the label 19 to the article 13 at the label retaining station 15. In the embodiment illustrated, the leading enclosure 33 includes a main body 45 (FIGS. 2 and 3) having the leading face section 39 thereon and passages 47 extending through the body from a chamber 49 formed between the body and a cover plate 51 and the openings 41. As best seen in FIG. 3, the face section 39 is concave. The cover plate 51 is releasably attached to the main body 45 in any suitable way, such as by threaded fasteners 53. A threaded opening 55 in the cover plate 51 enables the chamber 49 to be coupled via a conduit 57 through a control valve 59 to a source of vacuum pressure 61 and a source of air under pressure 63. The source of vacuum pressure 61 is also coupled to the trailing enclosure 31.
The leading enclosure 33 can be mounted on a post 65, which forms a portion of the supporting structure 35, by extending the post 65 through a bore 67 of the body 45. The angular and axial positions of the leading enclosure 33 about and along the post 65 can be adjusted, and the leading enclosure can be fixed in position by set screws 69 (FIG. 3).
To orient the articles 13, the label applicator 11 includes a wheel 71 rotatably mounted on the supporting structure 35 for rotational movement about a vertical rotational axis 73 (FIG. 1). The wheel 71 has a cylindrical peripheral surface 75, and at least an outer annular region 77 of the wheel is soft, flexible and resiliently deformable. For example, the wheel 71 may be constructed in the same manner as the corresponding wheel of Crankshaw U.S. Pat. No. 4,201,621. The wheel 71 is rotated counterclockwise as viewed in FIG. 1 by a motor 78.
The wheel 71 cooperates with guide means to hold the article 13 at the label retaining station 15 in a desired orientation. Although the guide means can be of different constructions, in the embodiment illustrated, it comprises a guide 79 (FIGS. 1 and 4) which includes linear guide bars 81 rigidly joined together by posts 83 along one edge of the conveyor 17 and having an opening in the form of an elongated slot 85 between them. The upper guide bar 81 is shown broken away in FIG. 4 to expose the enclosure 33, and a portion of the outline of the guide bar is shown in dashed lines. As shown in FIG. 4, the portion of the leading enclosure 33 and the leading face section 39 are received within the slot 85. The presence of the article 13 at the label retaining station 15 is sensed in a conventional manner by the article interrupting a beam of light from a source 87 directed toward photocell 89. The source 87 and the photocell 89 are suitably mounted on the supporting structure by a bracket 91 in any suitable manner.
In the embodiment illustrated, the label applicator 11 also includes a wrap around apparatus 93, which may be of conventional construction. The wrap around apparatus 93 includes a rail 95 mounted for movement on posts 97 which are in turn suitably mounted on brackets 98 of the supporting structure 35. The rail 95 is resiliently urged toward the articles 13 by springs 99 on the posts 97, respectively. The rail 95 comprises a rigid member 101, and a resilient cushion of suitable resilient foam 103 carried by the rigid member and facing the articles 13.
The wrap around apparatus 93 also includes an endless belt 105 mounted on a drive pulley 107 and idler pulleys 109. Thus, the belt 105 can be driven in the direction of the arrow "A" in FIG. 1. Also as shown in FIG. 1, the cushion 103 and the belt 105 are spaced apart sufficiently to accommodate passage of the articles 13 between them.
In use, the conveyor 17 moves the articles 13 in the direction of the arrow "A" in FIG. 1, and a label 19, which has been removed from the backing strip 21 by the peeler bar 27, is releasably retained due to differential pressure against the face sections 37 and 39 which combine to form a perforate face. When retained in this manner, the leading portion 43 of the label 19 is retained against the leading face section 39, and a trailing portion 110 of the label is retained against the trailing face section 37 by differential fluid pressure. The wheel 71 is continuously rotated counterclockwise by the motor 78 to give it a tangential velocity approximately equal to the velocity of the articles 13 which are continuously moved past the label retaining station 15 by the conveyor 17.
As one of the articles 13 nears the label retaining station 15, the bars 81 urge the article against the peripheral surface 75 to deform the peripheral surface and the annular region 77 sufficiently to hold the article 13 in a desired orientation. When the leading edge of the article 13 at the label retaining station 15 is sensed by the photocell 89, the valve 59 is switched from the source of vacuum 61 to the source of air under pressure 63 to provide a short duration blast of air under pressure through the conduit 57 and the openings 41 of the leading enclosure 33. Vacuum pressure is continuously applied from the source of vacuum 61 to the trailing enclosure 31. Accordingly, the leading portion 43 of the label is blown from the leading face 39 against the confronting panel of the article 13 while the subatmospheric pressure continues to retain the trailing portion 110 of the label 19 against the trailing face section 37.
The article 13 moves continuously with the conveyor 17, and as a result, pulls the label 19 from the trailing face section 37. The article 13 with the label 19 attached to only one face thereof proceeds to the wrap around apparatus 93 which rotates the article 13 in the direction of the arrow "B" in accordance with known wrap around techniques to apply the trailing portion 110 of the label to the other panels of the article. In the embodiment illustrated, the articles 13 have a generally rectangular peripheral wall, and the label 19 is applied to four sides or panels of the rectangular peripheral wall. Because the article 13 is accurately held at a desired orientation at the label retaining station, the leading portion 43 of the label is accurately attached to the confronting panel of the article.
The blast of air from the leading enclosure 39 must be of short duration, otherwise, as the article 13 moved along the conveyor 17, the label 19 might be blown against the wheel 71. Accordingly, the vacuum must return to the openings 41 rather quickly. FIG. 3 illustrates how the concave face section 39 provides a gap 111 between the label 19 and the openings 41, with the opposite ends of this gap being open. Accordingly, the vacuum is unable to suck the label 19 against the face 39 so as to prevent the article 13 from pulling the label 19 completely off of the face sections 37 and 39. In the embodiment illustrated, the concave face section 39 is curved; however, the concave configuration could be formed by any desired number of curved and/or flat sections.
Although exemplary embodiments of the invention have been shown and described, many changes, modifications and substitutions may be made by one having ordinary skill in the art without necessarily departing from the spirit and scope of this invention.
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A label applicator for labeling articles moving along a path which includes a label retaining device for retaining labels at a label retaining station, a label dispenser for dispensing labels onto the label retaining device, a rotatable wheel for use in orienting articles at the label retaining station, a label transfer device for blowing a leading portion of the label on the label retaining means onto an article at the label retaining station while allowing a trailing portion of the label to remain on the label retaining device so that movement of the article past the label retaining station pulls the trailing portion of the label from the label retaining device, and a label wrap device downstream of the label retaining station for applying the trailing portion of the label to the article.
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REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation-in-part to U.S. application Ser. No. 10/892,509, filed Jul. 14, 2004, which is a continuation of U.S. Pat. No. 6,770,695, issued Aug. 3, 2004, which claims priority to U.S. provisional patent application No. 60/223,624, filed Aug. 7, 2000. Each of the foregoing references is herein incorporated by reference in their entirety.
BACKGROUND OF THE INVENTION
[0002] The repair of bone defects and augmentation of existing bone often require the use of permanent bio-resorbable materials. Such materials may include autogenous bone graft, allogeneic graft, allogeneic bone graft, or alloplastic materials inclusive of various calcium phosphate ceramics, calcium phosphate cements, calcium sulfate materials, bioglass materials, and composites or other combinations thereof. Calcium sulfate, which is a form of plaster of paris, is a fully bioresorbable material which, for sometime, has been commonly used in cement and pellet form to repair bone defects.
[0003] When calcium sulfate is used as a cement to fill a bone void, fracture, or other defect, this material dissolves at a rapid rate, i.e., approximately one millimeter per week from the exterior of the cement towards the center thereof. Research of the present inventors has shown that this material causes precipitation of calcium phosphate deposits as it is resorbed at the surgical site. These precipitates, it has been shown, stimulate and direct the formation of new bone. On the other hand, it is important for purposes of optimal result that calcium sulfate, calcium phosphate, or any other bone repair material stay at the surgical site for a considerable period of time in order to inhibit soft tissue filling of the defect and to stimulate bone repair. However, currently used calcium sulfate materials are typically resorbed by human bone within two to seven weeks, depending upon the calcium sulfate form and the particular surgical site, which cannot be retained at the site for longer periods. As noted, such material is resorbed faster than it can be replaced by new bone thereby reducing its value to both patient and practitioner.
[0004] As such, the principal concern and difficulty expressed by practitioners (such as orthopedics or maxiofacial surgeons) are that calcium sulfate materials bio-resorb or dissolve too rapidly at a surgical or a recipient site, and, thereby, outpace the formation of new bone in human patients. Therefore, a need arises for improved calcium sulfate based compositions which can resorb at the recipient site in a rate desirably matching the rate bone growth.
SUMMARY OF THE INVENTION
[0005] The present invention relates to an implant composition having controlled resorption rate in vivo for stimulating bone growth, a particle used in such a composition, methods of making such implant compositions, and a calcium sulfate putty/paste.
[0006] In one aspect of the present invention, an implant composition having controlled resorption rate comprises a calcium sulfate compound, polymer containing particles, and a setting agent for setting the calcium sulfate compound and the polymer containing particles into a heterogeneous solid composition. Upon setting, the calcium sulfate compound forms a matrix and the polymer containing particles settled within the matrix.
[0007] In another aspect, the present invention comprises a method of using implant materials to make the inventive implant composition for bone augmentation and bone defect reparation. The method comprises the steps of: (a) mixing a calcium sulfate compound and polymer containing particles with a setting agent into a mixture, (b) applying the mixture, either by filling in a recipient site with the mixture, or by coating the mixture on a surface of a surgical implant prior to introducing the surgical implant into the recipient site, and (c) setting the mixture into a heterogeneous solid composition.
[0008] In a further aspect, the present invention relates to a kit of implant materials for bone augmentation and bone defect reparation. The kit comprises (a) dry powder of a calcium sulfate compound, and (b) polymer containing particles. The kit can further comprise a setting agent packed in a container, and instructions on how to use the kit for preparing the implant composition.
[0009] In another aspect of the present invention, a bone-growth stimulating particle is presented, a plurality of which for use together for forming a resorbable implant. The particle includes a size between about 425-850 μm in diameter and comprises a calcium sulfate compound and a resorbable polymer in a weight ratio of about 96:4 (for example).
[0010] In yet another aspect of the present invention, a bone-growth stimulating composition for forming a resorbable implant includes a plurality of particles having a size between about 425-850 μm in diameter and including a first calcium sulfate compound and a resorbable polymer in a weight ratio of about 96:4.
[0011] In yet another aspect of the invention, a bone-growth stimulating putty/paste for forming a resorbable implant is provided and comprises calcium sulfate powder, a plurality of polymer containing particles and a plasticizer/thickener. Such plasticizers/thickeners include at least one of, for example, carboxymethylcellulose, hydroxymethylcellulose, hydroxyethylcellulose, hydroxypropyl methylcellulose, hydroxyethylcellulose polyvinyl alcohol, polyvinyl pyrrolidone, hyaluronate and chitin derivatives such as chitosan.
[0012] The polymer containing particles in some embodiments of the putty may include a weight ratio of calcium sulfate to resorbable polymer of about 96:4 (or other weight ratio as presented in other embodiments of the present disclosure. In addition, a weight ratio of the polymer containing particles to the plasticizer/thickener may be between about 65:35 to 90:10.
[0013] Some of the putty material embodiments may also include, in addition to the polymer containing particles and plasticizer/thickener, a calcium sulfate powder, and a weight ratio of polymer containing particles to calcium sulfate to the plasticizer/thickener may be between about 60:30:10 to about 75:15:10.
[0014] In yet another aspect of the invention, a method for manufacturing particles for use in forming a resorbable implant for stimulating bone growth is provided and includes rotating calcium sulfate powder in a drum at a first predetermined drum speed, a first spraying of a resorbable polymer solution at a first predetermined rate on the calcium sulfate powder over a first predetermined period of time and drying the resulting particles.
[0015] It is accordingly an object of some of the embodiments of the present invention to provide an implant composition for the repair and augmentation of bone defects.
[0016] It is another object of some of the embodiments of the invention to provide an implant composition having controllable resorption rate in vivo, wherein the rate of resorption can be substantially matched to the rate of bone growth in a specific medical or dental application.
[0017] It is a further object of some of the embodiments of the invention to provide implant materials and a method for making the implant composition.
[0018] The above and yet other objects and advantages of the present invention will become apparent from the hereinafter set forth Brief Description of the Drawings and Detailed Description of the Invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 is a schematic view of an implant composition of one embodiment of the present invention immediately after introduction into a recipient site, showing the heterogeneous solid implant composition.
[0020] FIG. 2 is a view, sequential to that of FIG. 1 , showing a first phase of bioresorption of the implant composition at the recipient site.
[0021] FIG. 3 is a view sequential to that of FIG. 2 showing the beginning of resorption of the polymer containing particles of the implant composition.
[0022] FIG. 4 is a view, sequential to that of FIG. 3 , showing the end result of the bioresorption of the implant composition, which results stimulated bone growth with diminishing level of the implant composition.
[0023] FIG. 5 is a cross-sectional schematic view of the implant composition of the present invention used with a surgical implant which has buttress threads.
[0024] FIGS. 6 and 7 show a cross-sectional schematic view and a top view, respectively, of the implant composition of the present invention used with a surgical implant which has a smooth exterior surface.
[0025] FIG. 8 is a graph illustrating the half-life of some of the implant composition materials according to some of the embodiments of the present invention.
[0026] FIG. 9 is a degradation profile of an implant composition material according to one embodiment of the present invention.
[0027] FIG. 10A is an image of a bone having an implant composition material according to one embodiment of the present invention, four weeks after implantation.
[0028] FIG. 10B is an image of a bone having an implant composition material comprising pure calcium sulfate four weeks after implantation.
[0029] FIG. 11 is an enlarged image of a bone having an implant composition material according to one embodiment of the present invention, four weeks after implantation, with corresponding SRM graphs, illustrating that both calcium sulfate and calcium phosphate are present.
[0030] FIG. 12A is an image illustrating the histological response of a bone having an implant composition material according to one embodiment of the present invention at four weeks after implantation.
[0031] FIG. 12B is an enlarged image illustrating the histological response of the implant composition material according to the embodiment shown in FIG. 12A , illustrating a particle 1202 of the bone composition material, illustrating cells being attached to the particle and bone forming around the particle at four weeks after implantation.
[0032] FIG. 13A is an image of a bone having an implant composition material according to one embodiment of the present invention after eight weeks from implantation, illustrating bone growth in areas just outside the filler material.
[0033] FIG. 13B is an image of an implant composition material comprising pure calcium sulfate implant eight weeks after implantation, illustrating that most of the original calcium sulfate has been degraded with very little bone growth.
[0034] FIG. 14A is an image illustrating the histological response of a bone having an implant composition material according to one embodiment of the present invention at eight weeks after implantation.
[0035] FIG. 14B is an image illustrating the histological response of a bone having an implant composition material comprising pure calcium sulfate at eight weeks after implantation.
[0036] FIG. 15A is a planar X-ray of a bone having an implant composition material according to one embodiment of the present invention at eight weeks after implantation.
[0037] FIG. 15B is a micro CT slice from the bone of FIG. 15A
[0038] FIG. 15C is a micro CT slice of a bone having an implant composition material comprising pure calcium sulfate implant at eight weeks after implantation.
[0039] FIG. 16 is an image of a bone having an implant composition material according to one embodiment of the present invention of the present invention at sixteen weeks after implantation.
[0040] FIG. 17A is a micro CT image of a bone having an implant composition material according to one embodiment of the present invention at sixteen weeks after implantation.
[0041] FIG. 17B is an image of a micro CT slice of the same implant shown in FIG. 17A .
[0042] FIG. 18A an image illustrating the histological response of a bone having an implant composition material according to one embodiment of the present invention at 16 weeks after implantation.
[0043] FIG. 18B is an enlarged image of that of FIG. 18A .
DETAILED DESCRIPTION OF THE INVENTION
[0044] In one aspect of the present invention, an implant composition having controlled resorption rate comprises a calcium sulfate compound, polymer containing particles, and a setting agent for setting the calcium sulfate compound and the polymer containing particles into a heterogeneous solid composition. Upon setting, the calcium sulfate compound forms a matrix (M) and the polymer containing particles (P) settled within the matrix. FIG. 1 shows a cross-sectional schematic view of the heterogeneous solid implant composition before resorption occurs.
[0045] In another aspect, the present invention comprises a method of using implant materials to make the inventive implant composition for bone augmentation and bone defect reparation. The method comprises the steps of: (a) mixing a calcium sulfate compound and polymer containing particles with a setting agent into a mixture, (b) filing a recipient site with the mixture, and (c) setting the mixture into a heterogeneous solid composition.
[0046] The calcium sulfate compound preferably is a dry powder of preferably calcium sulfate hemihydrate, having a particle size between about sub-micron to about 20 microns. Suitable setting agents include water, alkaline metal salt solutions such as a saline solution, and an accelerant aqueous solution containing potassium salt. The setting agents set the implant materials into a heterogeneous solid composition, or a multiphasic cement with different speeds. The speed of setting can be controlled from seven minutes to one hour, depending on the setting agent used as well as desired surgical application. Among various setting agents, potassium salt solutions result in the fastest setting. For the purpose of the present invention, an aqueous solution containing potassium or sodium ions are preferably used. Most preferably, an aqueous solution containing potassium ions can be used. Suitable examples of potassium salts include potassium sulfate, potassium phosphate, and potassium fluoride. The concentration of potassium ion controls the speed of setting, the higher it is the faster the setting process. Preferably, the concentration of the potassium ions is in a range from about 0.01 molar to about 0.5 molar.
[0047] The polymer containing particles (P) comprises a calcium sulfate compound, and at least one resorbable polymer. The calcium sulfate compound in the polymer containing particles can be calcium sulfate dihydrate, also called preset calcium sulfate, or calcium sulfate hemihydrate, also called unset calcium sulfate, or a mixture thereof. In one embodiment, the calcium sulfate compound is mixed with a resorbable polymer to form the particles. The amount of resorbable polymer used in the particles controls resorption rate of the implant composition when it is implanted in a recipient site. In an alternative embodiment, the calcium sulfate compound of the particles is encapsulated in a coating (C) of a resorbable polymer, as shown in FIG. 1 . In this case, thickness of the resorbable polymer coating controls resorption rate of the implant composition in a recipient site. The thickness of the resorbable polymer coating is from about 2 microns to about 50 microns. For polymers that are only expected to last for a short time, a thin layer can be applied. For fast-resorbing coatings, or coatings expected to last for a long time, a thick coating can be applied. Furthermore, the resorbable polymer coating is not required to be a complete encapsulation. It has been observed that small local incomplete coatings, or coatings with defects (accidentally or intentionally), function as initial resorption sites of the polymer containing particles. An analogous situation can be found in time release medicine. It is known that medical pills with small controlled defects (drilled or molded) in polymer coatings are sometimes used to control drug release rates. A broad range of particle sizes can be used in the implant composition. The particle size can be determined depended on a particular application, and recipient site. For example, small particles are more suitable for dental fillings. On the other hand, larger pallets are more suitable for repairing bone fracture. Preferably, the particle size is more than 20 microns in diameter since when the particles are smaller than 20 microns, they may cause a negative foreign body response due to activation of macrophages.
[0048] In an additional embodiment, the particles can be made having combined characteristics of the two types of particles described above. Herein, the particles can include mixed calcium sulfate compound and a resorbable polymer, which are, additionally, encapsulated with a resorbable polymer coating.
[0049] In a further embodiment, the implant composition comprises two different types of polymer containing particles that have different rates of resorption. Such particles can, for example, be particles coated with different polymers, combinations of coated and mixed polymers, or particles with coating of different thickness, a typical range being 0.5 to 100 micrometers.
[0050] A wide variety of resorbable polymers can be used for the implant composition of the present invention. Suitable resorbable polymers include aliphatic polyesters of alpha-hydroxy acid derivatives, such as polyactides, polyglycolides, polydioxanone, and poly .epsilon.-caprolactone; hydrophobic polymers, such as carnuba waxes and their derivatives; water soluble polymers, such as poly(desaminotyrosyl-tyrosine ethyl ester carbonate), hereinafter poly (DTE carbonate) and their derivatives; and therapeutic polymers, such as those containing salicylate. A specific type of resorbable polymer can be selected depending on the purpose of applications, expected bone growth speed of a particular surgical site, and environment or condition of a recipient site. For the purpose of the present invention, polyactides, polyglycolides and poly (DTE carbonate) are used preferably. It is known that polyactides, including D and L isomers, and DL copolymers of polylactic acid, have a long time history in their use as biomedical devices. These polymers are readily available commercially. The polyglycolides and poly (DTE carbonate) have also been used for bone reparation.
[0051] In general, resorbable polymers resorb slower in vivo than calcium sulfate compounds. Therefore, the amount of resorbable polymer used in the particles, mixed or coated, controls resorption rate of the implant composition when it is implanted in a recipient site. The polymer containing particles can comprise about 0.1% to about 50% (w/w) of a resorbable polymer, with about 1.5% defining the best mode. When the amount of a resorbable polymer is too high, it may cause a negative body, that is, immune response. When used as a coating only, the above (w/w) range is about 0.1% to about 22%. The rate of resorption of the implant composition can be controlled of between three (3) and twenty eight (28) weeks (for example), depending on the types and amount of polymer(s) used.
[0052] In an additional embodiment, the present invention relates to a method of preparing the polymer containing particles. The polymer containing particles can be prepared by two methods: (1) a surface coating process, and (2) bulk mixing of polymer and calcium sulfate. In the surface coating process, preformed calcium sulfate particles are mixed with a polymer solution. The polymer solution forms a liquid coating on the calcium sulfate particles, and is allowed to dry and to form a polymer surface coating on the particles. The coating thickness and amount of penetration into the calcium sulfate depend on the concentration of polymer in the solution, and viscosity of the solution. Examples of suitable organic solvent can be used to dissolve the polymer and make the polymer solution include acetone and chloroform. In the bulk mixing method, a fine granular form of a polymer is mixed with a granular form of calcium sulfate. The mixture is then pressed or rolled into larger particles.
[0053] In another embodiment of the present invention, the polymer containing particles may be made as follows. A dilute L-polylactide (PPLA) solution is prepared by dissolving PLLA in methylene chloride (or other similar solvent). The PLLA solution may then be sprayed on calcium sulfate powder (e.g., calcium sulfate hemihydrate) in a rotating drum machine (e.g., Freund GX-20 Granurex). The mixture may then be rotated until small pellets are formed. The pellets may then be air dried for several hours, and then may be sieved. Pellets of between 425 to 850 microns are produced, and preferably, particles sized between about 425 to about 600 microns. A preferred weight ratio of calcium sulfate to PLLA (by weight) is between about 83:17 to about 97:3, with a most preferred weight ratio of about 96:4.
[0054] Specifically, polymer containing particles of a size outlined above may be made as follows. First, the rotating drum mechanism is preheated to between about 40° C. and 80° C., and preferably about 50° C. Calcium sulfate hemihydrate powder is added to the drum and the drum is then rotated between about 200 and 400 RPM, and preferably at about 350 RPM (either prior to, during or after addition of the calcium sulfate). A PLLA solution is sprayed onto the calcium sulfate powder at approximately 60 grams per minute (±10 grams per minute) between about 10-20 minutes, and preferably for about 15 minutes. The drum speed is then increased 10-20%, or between about 300 to about 500, and preferably to about 400 RPM, and the PLLA solution is then sprayed onto the calcium sulfate/PPLA solution mixture at a rate of about 40 grams per minute (±10 grams per minute) for between about 100-300 minutes, and preferably about 200 minutes. Formed particles are then air dried in the drum and rotor speed is decreased between about 25-50%, or between about 200-300 RPM, and preferably to about 250 RPM (generally between about 50-80 minutes, and preferably for about 60 minutes). The dried particles are preferably substantially free of the solvent used in the PLLA solution. The particles may then be removed, and the drum mechanism cooled thereafter by rotating the drum at about 250 RPM for about 10 minutes or however much longer it takes to cool down the drum.
[0055] In one example of the above embodiment, a preferred weight ratio of calcium sulfate to polymer is about 96:4. For example, a PLLA solution of 30.6 grams of PLLA dissolved in about 7619.4 grams of methylene chloride (or other similar solvent) is sprayed onto 574.5 grams of calcium sulfate. In this example, only about 70-80% (and preferably about 77%) of the PLLA solution need be sprayed onto the calcium sulfate to obtain the weight ratio of about 96:4 calcium sulfate to PLLA (and, in one aspect, a most preferred weight ratio of about 95.75:4.25), which corresponds to about 77.2% of the PLLA. This weight ratio corresponds to a material which substantially, and more preferably, completely degrades in about 16 weeks in vivo (according to some embodiments of the invention).
[0056] FIG. 8 is a graph illustrating the half-life of pure calcium sulfate ( 502 ), polymer-containing particles corresponding to a calcium sulfate to PLLA weight ratio of 97:3 ( 504 ), polymer-containing particles corresponding to a calcium sulfate to PLLA weight ratio of 90:10 ( 506 ), and polymer-containing particles corresponding to a calcium sulfate to PLLA weight ratio of about 83:17 ( 508 ). Although not shown, a material having a calcium sulfate to PLLA weight ratio of about 96:4 includes a typical half-life of about 70 days, with only 10% of the material being left after 135 days (the 10% of material that is left will most likely be calcium phosphate). As can be seen, the 83:17 weight ratio polymer containing particles show considerable longer half-life over calcium sulfate or any of the other two weight ratio examples listed or pure calcium sulfate.
[0057] In still other embodiments, polymer containing particles may be made by first creating calcium sulfate particles of between about 700 to 1000 microns first and thereafter coating the particles. Such calcium sulfate particles may be created by making a calcium sulfate mixture, which may be made by mixing calcium sulfate with distilled (preferably) water in a weight ratio of about 1 gram of calcium sulfate to about three-tenths (0.3) grams of water. This mixture may then be pressed molded into 700-1000 microns (for example) and then dried. Such particles may then be coated with a PLLA/methylene chloride (solvent) solution (e.g., the solution listed above) and allowed to dry. The weight ratio of calcium sulfate to PLLA for such polymer containing particles may be between about 83:17 to about 97:3.
[0058] Some embodiments of the present invention are directed to a calcium sulfate putty having polymer containing particles. One such embodiment comprises a mixture of polymer containing calcium sulfate particles according to any of the embodiments noted in the present disclosure (e.g., calcium Sulfate(CS)/PLLA composite) and a plasticizer/thickener, in a weight ratio of CS/PLLA:plasticizer/thickener of between about 65:35 to 90:10, and preferably about 85:15. Such plasticizers/thickeners may include, for example, at least one of carboxymethylcellulose, hydroxymethylcellulose, hydroxyethylcellulose, hydroxypropyl methylcellulose, hydroxyethylcellulose polyvinyl alcohol, polyvinyl pyrrolidone, hyaluronate and chitin derivatives such as chitosan.
[0059] Another such embodiment may comprise the polymer containing calcium sulfate particles, a separate calcium sulfate powder and a plasticizer/thickener in a weight ratio of CS/PLLA:CS:plasticizer/thickener between about 60:30:10 to about 75:15:10, and preferably about 70:20:10. Such material may also be prepackaged for sale and use.
[0060] FIG. 1 to FIG. 4 illustrate the resorption process of the implant composition of the present invention, according to some embodiments of the invention, and the mechanism of controlled resorption rate for a proper stimulation of bone growth. FIG. 1 shows the structure of the heterogeneous solid implant composition after the mixture of calcium sulfate compound, polymer encapsulated particles, and the setting agent is being applied in a recipient site, and set into a heterogeneous solid composition. FIG. 2 shows the first phase of bioresorption of the implant composition. The calcium sulfate compound in the matrix resorbs first, that is, the first two to four weeks (generally) after implantation, thereby forming a porous system which will fill with granulation tissue (G) during said timeframe. The process of resorbing calcium sulfate forms deposits of calcium phosphate (CP) which has function to encourage early bone in-growth (B).
[0061] FIG. 3 shows the second phase of the resorption, i,e., resorption of the polymer containing particles. This generally occurs as early as four weeks or as late as twenty weeks after applying the implant composition, depending upon the particular formulation of the composition and application. In the example, as reflected in FIG. 3 , the polymer coating has partially broken down allowing resorption of the encapsulated calcium sulfate compound. Therein, the resorbing calcium sulfate compound produces deposits of calcium phosphate (CP) as in the first phase of resorption (see FIG. 2 ), and additional bone in-growth will occur.
[0062] FIG. 4 shows the end result of the resorption of the implant composition. This occurs generally as early as six weeks or as late as twenty four weeks depending upon the particular formulation of the composition and application (for example). By this time only residual amount of polymer material remains and full bone in-growth has occurred. In addition, most calcium phosphate deposits have been removed by bone remodeling, only a small amount of calcium phosphate deposits within the original particles can still be visible in new bone growth. It is understood that bone remodeling is a natural process that normally occurs very slowly. Remodeling occurs as new bone is constantly formed by osteoblasts and removed by osteoclasts. The balance of the two processes represents an equilibrium that determines how much bone is present at any given time. However, remodeling is rapid during healing, and virtually all of the immature bone that is formed during early healing is remodeled and replaced by more mature bone. The calcium phosphate deposits formed by the dissolving calcium sulfate are similar to bone mineral, and are also remodeled and replaced by more mature bone during this period of time.
[0063] The implant composition of the present invention can be used for the repair, augmentation, and other treatment of bone. The implant composition possesses significant advantages over existing calcium sulfate cements and pellets used clinically for bone repair and regeneration. More particularly, current calcium sulfate materials are typically resorbed by human bone within two to seven weeks, depending upon the calcium sulfate form and the particular surgical site, however, cannot be retained at the site for longer periods. As noted, such material is resorbed faster than it can be replaced by new bone thereby reducing its value to both patient and practitioner. The implant composition of the present invention can be designed to resorb in phases in accordance with the needs of a specific surgical application and environment of a recipient site, therein allowing substantial control of resorption rate. The resorption rate can be controlled, for example, between eight and twenty four weeks (for example), which substantially matches the rate of bone growth.
[0064] On the other hands, since methods involving separate use of calcium sulfate and polymeric components have long been established as safe and fully bioresorbable, clinical utilities and feasibility of the present invention are apparent. In particular, the implant composition of the present invention can be applied in dentistry for bone repairing and augmentation with or without a surgical implant.
[0065] FIG. 5 shows an example of using the implant composition of the present invention with a surgical implant. As shown, a surgical implant 10 is furnished at a surgical site 12 for the purpose of establishing bio-integration with surrounding bone tissue 14 . An implant of the type of implant 10 includes buttress treads 16 (or other threading) and an integral collar 18 which comprises an upper part 20 and a lower part 22 . Located above bone tissue 14 is a cortical bone layer 24 , an optional bio-resorbable barrier layer 26 (described below) and a gum or soft tissue layer 28 . The implant composition 30 of the present invention is filled in between bone tissue 14 and surgical implant 10 as an osseo-stimulative. It is to be understood that the implant composition can be applied to implant 10 before insertion into the osseotomy site or can be applied to the site 12 , prior to insertion of the implant. Further, any of the surfaces of implant 10 inclusive of parts 20 and 22 of the collar 18 can be provided with cell growth stimulative microgeometry in accordance with our co-pending application Ser. No. 09/500,038. When a surgical implant exhibits an entirely smooth external geometry, as is the case with an implant 50 in FIG. 6 , an osseo-stimulative surface 52 ( FIG. 7 ) made of the implant composition of the present invention is more suitable when physically adhered to the implant at a pre-operative site. It is, however, to be appreciated that a paste of the implant composition can be applied to an osseotomy site in combination with use of implant 50 and its osseo-stimulative surface 52 .
EXAMPLE
[0066] In vitro degradation profiles polymer-containing particles according to an embodiment of the present invention having calcium sulfate to PLLA weight ratio of about 96:4 (hereinafter referred to as “BoneGen-TR”) and pure calcium sulfate were determined. One-twentieth of a gram of each material was weighed, wrapped in porous nylon mesh, and weighed again to determine the weight of the nylon mesh. It was then incubated in simulated body fluid (SBF) for one hour, removed from SBF, air-dried, and weighed again. This weight was considered the baseline weight to perform future calculations and to determine degradation profiles for each of the materials. Samples were then incubated in the SBF, removed from the fluid every fourth day, air-dried, and weighed. The SBF was then discarded and the test materials were again incubated in fresh SBF. Samples were weighed until three (3) consecutive readings showed no loss of weight.
[0067] In vivo studies: BoneGen-TR pellets were sterilized by gamma radiation. The bone response to BoneGen-TR and pure calcium sulfate was studied in a rabbit tibial intramedullary canal model. Twelve New Zealand White rabbits were used in this study. A surgical incision was made over the antero-medial aspect of the proximal tibia below the tibial plateau to gain access to the proximal intramedullary canal. The periosteum was elevated and a 3.0 mm diameter opening was made in the cortex using a 1.0 mm bur bit and 2.0 mm and 3.0 mm spade bits. Each defect was packed with BoneGen-TR or a pure calcium sulfate control (SurgiPlaster), filling the intramedullary canal with 0.3-0.5 ml of the material using a small funnel and delivery system. The site was closed by suturing the periosteum over the bone opening and suturing the subcutaneous, and cutaneous layers with interrupted resorbable sutures. Animals were sacrificed at 4 weeks (5 animals), 8 weeks (5 animals) and 16 weeks (2 animals). Based on previous experience and published literature, pure calcium sulfate (SurgiPlaster) degrades completely by 4-5 weeks and, hence, it was not implanted in animals to be sacrificed at 16 weeks.
[0068] Analysis of Specimens: After sacrifice, gross examination of the implant area was performed. The portion of the tibia with the specimens was harvested after sacrifice. These samples were first imaged using a high resolution Faxitron x-ray system. The specimens were then preserved in 70% ethanol and dehydrated in increasing concentrations of ethyl alcohol. Phosphate buffered formalin was not used because the phosphate buffer can cause formation of artifactual mineral deposits. Ethanol adequately preserves the tissue, stops dissolution of the CS component, and preserves mineral structure. They were finally infiltrated and embedded in hard poly (methyl) methacrylate (PMMA).
[0069] Micro Computed Tomography analysis (MicroCT): Embedded and unembedded samples were examined using a Scanco 40 microCT system (Scanco Medical, Geneva, Switzerland). Samples were analyzed at 70 kvp, with 150 ms dwell timer and 12 μm resolution. Planar images were used to examine local bone response, degradation of the test materials, and in some cases, to measure volumetric amounts of bone present.
[0070] Sectioning of Embedded Specimens: A Buehler Isomet™ low speed saw and Isocut® diamond wafering blade were used to obtain histological sections 300 μthick. These sections were then polished to a 1200 grit finish and examined using both scanning electron microscope (in back scattered electron imaging and x-ray microanalysis modes) and light histopathology.
[0071] Backscattered Electron Imaging (BEI) and X-ray Microprobe (XRM) Analysis: BEI (examined under Hitachi S3500N scanning electron microscope) mode provides information about microscopic structure and density of the specimens. This allows visualization of bone formation and remodeling as well as changes in the test materials. XRM (Princeton Gamma Tech IMIX system with PRISM light element detector) was used to analyze changes in the chemical composition of test materials.
[0072] Histopathological Analysis: The cut sections were mounted on Plexiglas slides and ground down to 50-
[0073] 80 μthick sections. A Stevenel's Blue and Van Giesons Picro-Fuschin differential tissue staining protocol (SVG) was used for staining the sections. SVG stains soft tissue green-blue, muscle blue-green, cartilage violetblue and mineralized tissue red to orange. The stained sections were also examined microscopically using both transmitted and incident light for any significant tissue response to the implanted test materials. The sections were then photographed at various magnifications using an Olympus SZ10 compound stereomicroscope with attached Olympus microphotography equipment.
[0074] Results: In Vitro Degradation of BoneGen-TR: BoneGen-TR underwent slower degradation as compared to pure calcium sulfate. Previous studies of the in vitro degradation of pure calcium sulfate demonstrate complete degradation by the end of 4 or 5 weeks. BoneGen-TR underwent almost linear degradation with a half life of approximately 75 days. See FIG. 9 illustrating the BoneGen-TR degradation profile.
[0075] In vivo results: 4 week observations. Pure calcium sulfate implants were completely degraded at the 4-week time point. This material left behind some residual calcium phosphate deposits at this time point and developed very little bone in-growth in this type of animal model. Faxitron x-rays, scanning electron micrographs, and histopathology showed that BoneGen-TR degraded at a significantly slower rate than the pure calcium sulfate and showed little degradation at 4 weeks ( FIG. 1 ). SEM and corresponding XRM evaluation of BoneGen-TR implants showed that most of the implant was still calcium sulfate. But calcium phosphate was detected at the interface of the BoneGen-TR implant and surrounding bone. Histological analysis showed that osteoblast cells attached to the BoneGen-TR pellets and bone formed around individual BoneGen-TR pellets. Formation of calcium phosphate at the interface of the BoneGen-TR implant and bone and attachment of cells to individual BoneGen-TR pellets are two important early signs of a good bone response to BoneGen-TR.
[0076] FIG. 10A is a Faxitron image of BoneGen-TR at 4 weeks, illustrating that it has not undergone much degradation at 4 weeks. In contrast, a Faxitron image of pure calcium sulfate implant at 4 weeks, shown in FIG. 10B , illustrates that most of the original pure calcium sulfate implant degraded and hence is not visible. Very little bone formation is observed.
[0077] FIG. 11 is a SEM of BoneGen-TR implant at 4 weeks with corresponding XRM. Most of the implant is still calcium sulfate, but calcium phosphate is observed at the interface.
[0078] FIGS. 12A-12B illustrate photos of a histological response to BoneGen-TR at 4 weeks. In FIG. 12A , BoneGen-TR pellets are still present, but they are breaking down, with some bone in-growth being apparent. FIG. 12B illustrates a high magnification view illustrating cells attaching to BoneGen-TR and bone forming around individual pellets.
[0079] 8 week observations. At the end of 8 weeks, BoneGen-TR pellets were seen slowly degrading. Significant quantities of new bone were observed on the surfaces of the BoneGen-TR pellets (see FIG. 13A ). Calcium phosphate formation at the periphery of the implant was observed on faxitron images and histological slides. Micro CT showed most of the original defect was filled with mineral. The original BoneGen-TR implant and newly formed calcium phosphate contributed to this mineral. Pure calcium sulfate implants were completely degraded (see FIG. 13B ). No trace of original implant was observed at 8 weeks. At the same time, only small amounts of bone were formed in the defects filled with pure calcium sulfate implants. Histological pictures showed that the defects were filled with soft tissue and a minimal amount of bone.
[0080] FIG. 14A illustrates histological response to BoneGen-TR pellets at 8 weeks. As shown, bone is present towards the periphery of implant. Most of the BoneGen-TR pellets are still present. Some of the pellets are converting to calcium phosphate and hence pick-up dark stain. FIG. 14B illustrates the histological response to pure calcium sulfate implant at 8 weeks, illustrating dark soft tissue mass with some dark staining mineral; bone is present in only small amounts.
[0081] Planar x-ray and thick slices ( FIGS. 15A and 15B ) of the BoneGen-TR implants, obtained at 8 weeks using micro CT, showed that most of the defect was filled with mineral deposits, pellets, and bone. Mineral fill was 51.4% ( FIG. 15A ); however, it is difficult to distinguish BoneGen-TR pellets from new calcium phosphate mineral deposits because they have similar densities. FIG. 15B illustrates a micro CT thick slice from same BoneGen-TR sample as shown in FIG. 15A . It showed 48.6% fill with the same components. FIG. 15C is a micro CT thick slice of a pure calcium sulfate implant at 8 weeks; new bone inside canal with cortex removed. It shows very little bone formation.
[0082] 16 week observations. The most interesting results were obtained at 16 weeks post implantation. At this time point, most of the BoneGen-TR implant was degraded; it left behind proliferating new bone which was seen on faxitron and micro CT as shown in FIG. 16 . Planar x-ray and thick slices ( FIGS. 17A-17B ) obtained using micro CT showed that most of the mineral deposits observed in defects filled with BoneGen-TR samples at 8 weeks were resorbed and the defects were filled with immature trabecular bone. Bone formation in the defect was measured up to 22%. There is typically very little bone formed in the rabbit intramedullary canal. Considering this fact, the amount of bone observed in the defect is extremely significant. Specifically, as shown in FIG. 17A , mineral fill observed in FIG. 15A has resorbed and is filled with immature trabecular bone; 17.35% of the total area was filled with bone. In FIG. 17B , a micro CT thick slice of the same BoneGen-TR sample illustrates new bone inside canal with cortex removed. Bone pattern is sometimes observed in the form of nodules or ghosts of the BoneGen-TR pellets.
[0083] These observations were confirmed histologically. The original BoneGen-TR implant was completely degraded and the defect was filled with newly formed bone and calcium phosphate mineral. FIGS. 18A-18B illustrate the histological response to BoneGen-TR at 16 weeks: no BoneGen-TR pellets are observed. The dark staining area is calcium phosphate formed as a result of BoneGen-TR degradation interspersed with bone. Significant amounts of new bone are present. Bone grows from the endosteum towards the center of the medullary canal. In these sections it has not yet reached the center of the canal, but there is significant bone filling.
[0084] Conclusions: This study has demonstrated that:
BoneGen-TR is completely degradable in vitro and in vivo. It is biodegradable and osteoconductive. It elicits a benign cellular and tissue response at early and late time points. When implanted in the body, it degrades and facilitates the formation of new bone in the defect.
[0089] Whereas pure calcium sulfate implants were completely degraded within 4 weeks and encouraged only small amounts of bone formation, BoneGen-TR implants took 16 weeks to degrade and stimulated vigorous bone formation into the defects without any adverse tissue response. Based on these observations, it can be concluded that BoneGen-TR is a safe and efficacious bone graft material.
[0090] The implant materials of the present invention can be sold as a kit. The kit can comprise dry powder of calcium sulfate compound, one or more types of polymer containing particles. The kit can further comprise a setting agent packed in a container. The kit can also include instructions on how to prepare the implant mixture, apply it in a recipient site and set it into the solid implant composition.
[0091] While there has been shown and described the preferred embodiment of the instant invention it is to be appreciated that the invention may be embodied otherwise than is herein specifically shown and described and that, within said embodiment, certain changes may be made in the form and arrangement of the parts without departing from the underlying ideas or principles of this invention as set forth herewith.
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A bone-growth stimulating composition for forming a resorbable implant, methods for making such a composition and a corresponding putty/paste material. In some embodiments of the invention, such a material includes a plurality of particles having a predetermined size and comprising a first calcium sulfate compound and a resorbable polymer in a predetermined weight ratio. Methods for making such a material include rotating calcium sulfate powder in a drum at a first predetermined drum speed, spraying of a resorbable polymer solution at a predetermined rate on the calcium sulfate powder over a predetermined period of time and drying the resulting particles. Such compositions allow resorption rates of the implant composition in vivo to be controlled, and my vary between eight and twenty-four weeks (for example), which can be matched to substantially correspond to a rate of bone growth in a particular application. The implant composition of the present invention can be used for the repair, augmentation, and other treatment of bone.
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RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Patent Application No. 61/526,835 filed Aug. 24, 2011 by the same inventor and entitled “Trash Container with Easily Removable Bag.” This application also claims priority to U.S. Provisional Patent Application No. 61/667,445 filed Jul. 3, 2012 by the same inventor and entitled “Trash Container with Easily Removable Bag and Interlocking Ring.” U.S. Provisional Patent Application Nos. 61/526,835 and 61/667,445 are hereby incorporated by reference in their entireties, including the drawings, as if repeated herein in their entireties.
BACKGROUND
[0002] The present invention relates generally to trash containers, and more particularly to a trash container having a liner for accepting a plastic bag.
[0003] Removing a plastic trash bag from a garbage container becomes difficult primarily due to a vacuum seal that is formed between the bag and the container. Lifting a trash-filled bag from the container typically creates a vacuum between the bag and the container bottom and sides. Difficulty increases for the elderly and the physically impaired when trying to lift weight due to the filled bag while simultaneously fighting this vacuum. Additionally, even if the vacuum is minimal or eliminated, friction between the bag and the container sill inhibits bag removal, as many containers are relatively light weight and simply lift off of the floor along with attempts to lift the bag from within. A lack of sturdiness of most containers can further inhibit the separation of bag and container, as the container is difficult to hold in a non-flexing posture. Complicating this problem is the need to solve the problem without increasing the cost of the trash container, as consumers will not pay for increased costs associated with a trash can. Therefore, what is needed is an inexpensive trash container that solves the aforesaid problems.
SUMMARY OF THE INVENTION
[0004] The present invention solves these and other problems by providing trash container with a user actuated release mechanism that releases the container from the base allowing lifting of the container off the base without the filled trash bag, thereby leaving the filled trash bag disposed on the base of the trash can. The trash container of the present invention enables removal of the trash bag without requiring lifting of the filled trash bag to the top of the trash container. In this manner, the filled trash bag can be dragged or lifted slightly when being taken out to the curbside for pickup.
[0005] According to one aspect of the present invention, an exemplary embodiment of a trash container includes a cylindrical liner that attaches to a base unit. The liner and the base unit are locked together via an actuating mechanism. The actuating mechanism locks the liner to the base unit when the liner is lowered onto the base unit and force is applied to the top of the liner. When the user applies a small force, the actuating mechanism “clicks” to lock the liner to the base. Once locked to the base, the liner can accept a plastic bag, into which garbage is placed over time. A foot operated release disengages the actuating mechanism so that the liner is released from the base. Then, the liner may be easily lifted from the base unit leaving the garbage filled plastic bag sitting on the base unit. A foot operated release pushes a rod that engages the actuating mechanism rotating the actuating mechanism outside of the liner, thereby releasing the liner from the base. When the liner is lowered, pressure applied to the top of the liner depresses the foot operated release, thereby enabling the actuating mechanism to rotate into a recess or slot in the liner that accepts the actuating mechanism. Once the actuating mechanism is properly inside the recess or slot, the actuating mechanism provides a “click” indicating that the liner is properly placed on the base and locked in position, so a plastic bag may then be introduced into the liner.
[0006] According to another aspect of the present invention, a trash container is provided with an interlocking ring that engages with a door, which can be opened when the interlocking ring is removed. In this manner, the filled trash bag can be dragged or lifted slightly when being taken out to the curbside for pickup.
[0007] According to another aspect of the present invention, an exemplary embodiment of a trash container includes an inner liner upon which a trash bag sits. The inner liner fits inside the outer container, but is somewhat smaller in height to enable a filled trash bag to be easily lifted over the top of the inner liner. An interlocking ring fits over the top of the door so that the door cannot be removed while the ring remains in place. Once the ring is removed, the door can be operated. The door can be hinged at the side, at the bottom or at the top. Alternatively, the door can be formed to slide into place. A foot pedal enables the user to open the lid of the trash container to place trash in the bag.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 depicts an exemplary embodiment of trash container according to one aspect of the present invention as shown in a side view.
[0009] FIG. 2 depicts the exemplary embodiment of the trash container from FIG. 1 as shown in a top view.
[0010] FIG. 3 depicts another exemplary embodiment of a trash container according to another aspect of the present invention shown in a top view.
[0011] FIG. 4 depicts another exemplary embodiment of a trash container according to another aspect of the present invention shown in a side view.
[0012] FIG. 5 depicts the base unit of the exemplary embodiment of FIGS. 3-4 shown in a top view.
[0013] FIG. 6 depicts another exemplary embodiment of trash container according to yet another aspect of the present invention.
[0014] FIG. 7 depicts yet another exemplary embodiment of trash container according to still another aspect of the present invention.
[0015] FIG. 8 depicts yet another exemplary embodiment of a trash container according to yet another aspect of the present invention.
DETAILED DESCRIPTION
[0016] Turning to FIG. 1 , shown therein is an exemplary embodiment of a trash can 10 according to one aspect of the present invention. The trash can 10 includes a liner or container 11 that attaches to a base unit 12 .
[0017] A lid (not shown) may be placed on the liner 11 . The lid should be designed to fit the shape of the liner 11 . A typical foot operated lid may be used along with the trash container 11 of the present invention. Alternatively, a lid that is removed manually may be employed.
[0018] The base unit 12 includes at least a foot operated release mechanism or pedal 13 to enable the user to release the base unit 12 from the container 11 . The base unit 12 is also designed to fit the shape of the liner 11 .
[0019] An actuating mechanism 14 is used to enable the container 11 to be locked to the base 12 and to be released from the base 12 . The actuating mechanism 14 couples with the foot pedal 13 to accept a force from a user to release the container 11 from the base 12 . The foot pedal 13 is affixed to the base unit 12 via a pin (not shown) at the center of the foot pedal 13 that enables the lever 13 to move up and down at each end. The weight of the container 11 is sufficient to maintain the lever 13 in a position whereby the portion of the foot pedal 13 that accepts the user's foot is normally in the upwards position. Pressing one's foot on the foot pedal 13 moves the foot pedal 13 to its lowest or bottom position at the end that engages with the foot. The opposite end then moves upward. The upward movement of the opposite end of the foot pedal 13 moves a vertical rod 15 upwards. When the foot is removed from the foot pedal 13 , the opposite end of the foot pedal 13 then returns to the downward or bottom position, thereby moving the vertical rod 15 downwards. Thus, depressing the foot pedal 13 moves the rod 15 upwards and removing the foot from the foot pedal 13 enables the rod 15 to return to its lowest position.
[0020] One end of the rod 15 engages with a rotating actuator 14 , which rotates one direction as the rod 15 moves vertically upwards and rotates the opposite direction as the vertical rod 15 moves downwards. The rotating actuator 14 is spring loaded so that absent any pressure from the vertical rod 15 , the rotating actuator 14 remains engaged with its corresponding recess or slot 16 in the container 11 . The rotating actuator 14 is shaped to fit into a slot or recess 16 disposed in the side of container 11 . Multiple rotating actuators 14 may be employed to provide symmetry to the lock. Two actuators 14 are preferable, however, one will suffice.
[0021] The container 11 used in the present invention may be cylindrical in shape or have a square cross-section, or any other shape without departing from the scope of the present invention. The container 11 includes one or more recesses or slots 16 disposed in the sides of the container 11 . The location of the one or more recesses or slots 16 is preferably towards the end of the container 11 that engages with the base unit 12 , as this decreases the length of the rod 15 or mechanism that transfers the foot applied force from the base unit 12 up to the point at which the locking mechanism 14 engages with the slots or recesses 16 in container 11 .
[0022] The liner and the base unit are locked together via the actuating mechanism 14 . The actuating mechanism 14 locks the liner 11 to the base unit 12 when the liner 11 is lowered onto the base unit 12 and force is applied to the top of the liner 11 . When the user applies a small force, the actuating mechanism 14 “clicks” to lock the liner 11 to the base 12 . Once locked to the base 12 , the liner 11 can accept a plastic bag (not shown), into which garbage is placed over time. A foot operated release 13 disengages the actuating mechanism 14 from the liner 11 so that the liner 11 is released from the base 12 . Then, the 11 liner may be easily lifted from the base unit 12 leaving the garbage filled plastic bag sitting on the base unit. A foot operated release 13 pushes a rod 15 that engages the actuating mechanism 14 rotating the actuating mechanism 14 outside of the slots or recesses 16 in liner 11 , thereby releasing the liner 11 from the base 12 . When the liner 11 is lowered, pressure applied to the top of the liner 11 depresses the foot operated release 13 , thereby enabling the actuating mechanism 14 to rotate into a recess or slot 16 in the liner 11 that accepts the actuating mechanism 14 . Once the actuating mechanism 14 is properly inside the recess or slot 16 , the actuating mechanism 14 provides a “click” indicating that the liner 11 is properly placed on the base 12 and locked in position, so a plastic bag may then be introduced into the liner 11 .
[0023] Turning to FIG. 3 , shown therein is another exemplary embodiment of a trash container 30 according to the present invention shown in a front view. Embodiment 30 employs a button 31 on the top of the container 30 to release the locks 36 that enable removal of the can cylinder 33 from the base 34 , similar to the pedals in the embodiment of FIGS. 1-2 . Lock actuator platform 35 lowers when can cylinder 33 engages which rotates locks 36 into locking position 37 . Rod 32 connects button 31 to actuating mechanism (not shown) in base 35 .
[0024] Turning to FIG. 4 , shown therein is a side view of the embodiment 30 of FIG. 3 with the actuator button 31 disposed on top of the can cylinder 33 . Rod 32 which is hidden inside the can cylinder engages the actuating mechanism when the can cylinder 33 is placed in the base 34 . Recesses 37 are where the locks 36 engage.
[0025] Turning to FIG. 5 , shown therein is base 34 with a top button as in the embodiments of FIGS. 3-4 shown in a top view. In this view, lock actuator platform 35 can be seen as well as location 38 where the rod penetrates the base 34 to engage the actuating mechanism (not shown).
[0026] When the cylinder 33 is lowered onto the base 34 , the spring tensioned platform(s) 35 are pushed down causing the locks 36 to rotate into the engaged position thereby locking the cylinder in place in recesses 37 . Depressing the button or pedal, releases the locks 36 and also allows the platform(s) 35 to return to the upper position when the cylinder 33 is removed.
[0027] Alternatively, when the cylinder 33 is lowered onto the base 34 , the button or pedal is depressed which actuates a rod 32 that moves the locks 36 into the engaged position locking the cylinder 33 into place. Depressing the button or pedal again, releases the locks so the cylinder 33 can be removed.
[0028] The trash container of the present invention may employ various actuating mechanisms (e.g., foot operated or hand operated) in many possible locations (e.g., top or bottom) without departing from the scope of the present invention.
[0029] Turning to FIG. 6 , shown therein is an exemplary embodiment of a trash can 60 according to one aspect of the present invention. The trash can 60 includes a liner 61 upon which a trash bag (not shown) rests. The trash can 60 employs a hinged door 62 , which is hinged on the side. An interlocking trash bag control ring 63 is used to place on top of the hinged door 62 in interlocking groove 64 so that the door 62 cannot be opened while the ring 63 remains in place. The ring 63 has an upper lip around its circumference that interlocks with groove 64 on the can allowing the ring 63 to fit snugly around the top of the can. The interlocking feature serves the purpose of keeping the door from opening unintended as more and more trash is stuffed into the trash bag. The ring 63 is of varying heights depending on the size of the trash can. The ring 63 also holds the trash bag in an open and upright position so that trash can be easily put into the trash bag and so that the trash bag does not fall into the base of the can. Trash bag slack can also be taken up by inserting the excess bag into the back of the ring through a hole 65 in the ring wall.
[0030] A lid fits on the top of the interlocking ring and is designed to fit the shape of the outer container. A typical foot operated lid may be used along with the trash container of the present invention. Alternatively, a lid that is removed manually may be employed.
[0031] Turning to FIG. 7 , shown therein is an exemplary embodiment of a trash can 70 according to one aspect of the present invention. This embodiment 70 employs a slide in door panel 71 that slides into place along sliding groove 72 . The door panel 71 is locked in place via locking ring 73 . FIG. 7 shows different views of the trash can 70 with the top open and closed with the sliding door locked in place.
[0032] Turning to FIG. 8 , shown therein is an exemplary embodiment of a trash can 80 according to yet another aspect of the present invention. This embodiment 80 employs a lower hinged front door 81 . The door panel 81 is locked in place via locking ring 83 . FIG. 8 shows different views of the trash can 80 with the top open and closed with the door locked in place.
[0033] The container used in the present invention may be cylindrical in shape or have a square cross-section, or any other shape without departing from the scope of the present invention.
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Disclosed is a trash container with a user actuated release mechanism that releases the container from the base allowing lifting of the container off the base, thereby leaving the filled trash bag disposed on the base of the trash can. The trash container of the present invention enables removal of the trash bag without requiring lifting of the filled trash bag to the top of the trash container. In this manner, the filled trash bag can be dragged or lifted slightly when being taken out to the curbside for pickup. In another embodiment of a trash container, a door panel is locked in place using a locking ring that once removed enables opening of the door panel to remove the trash bag. In this manner, the filled trash bag can be dragged or lifted slightly when being taken out to the curbside for pickup.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a valve assembly for use in a wellbore. More particularly, the invention relates to a valve assembly that allows fluid flow to pass through the valve in either direction. More particularly still, the invention relates to a dual purpose valve assembly for controlling the fluid flow during installation of a casing in a wellbore and subsequently for use as float equipment to facilitate the injection of zonal isolation fluids.
2. Description of the Related Art
Hydrocarbon wells are conventionally formed one section at a time. Typically, a first section of wellbore is drilled in the earth to a predetermined depth. Thereafter, that section is lined with a tubular string, or casing, to prevent cave-in. After the first section of the well is completed, another section of well is drilled and subsequently lined with its own string of tubulars, comprised of casing or liner. Each time a section of wellbore is completed and a section of tubulars is installed in the wellbore, the tubular is typically anchored into the wellbore through the use of a wellbore zonal isolation fluid, like cement. Zonal isolation includes the injection of cement into an annular area formed between the exterior of the tubular string and the borehole in the earth therearound. Zonal isolation protects the integrity of the wellbore and is especially useful to prevent migration of hydrocarbons towards the surface of the well via the annulus.
Zonal isolation methods of string are well known in the art. Typically, the cement fluid is pumped down in the tubular and then forced up the annular area toward the surface. By using a different fluid above a column of the cement, the annulus can be completely filed with cement while the wellbore is substantially free of cement. Any cured cement remaining in the wellbore is drillable and is easily destroyed by subsequent drilling to form the next section of wellbore.
Float shoes and float collars facilitate the cementing of tubular strings in a wellbore. In this specification, a float shoe is a valve-containing apparatus disposed at or near the lower end of the tubular string to be cemented into in a wellbore. A float collar is a valve-containing apparatus that is installed at some predetermined location, typically above a shoe within the tubular string. In certain cases, float collars are required rather than float shoes. However, in this specification, the term float shoe and float collar will be used interchangeably.
The main purpose of a float shoe is to facilitate the passage of cement from the tubular to the annulus of the well while preventing the cement from returning or “u-tubing” back into the tubular due to gravity and fluid density of the liquid zonal isolation fluids. In its most basic form, the float shoe includes a one-way valve permitting fluid to flow in one direction through the valve, but preventing fluid from flowing back into the tubular from the opposite direction. The float shoes usually include a cone-shaped nose to prevent binding of the tubular string during run-in.
Typically, wellbores are full of fluid to protect the drilled formation of the borehole and aid in carrying out cuttings created by a drill bit. When a new string of tubulars is inserted into the wellbore, the tubulars must necessarily be filled with fluid to avoid buoyancy and equalize pressures between the inside and the outside of the tubular. For these reasons, a float shoe should have the capability to temporarily permit fluid to flow inwards from the wellbore as the tubular string is run into the wellbore and fills the tubular string with fluid. In one simple example, a springloaded, normally closed, one-way valve in a float shoe is temporarily propped in an open position during run-in of the tubular by a drillable object, which is thereafter destroyed and no longer affects the operation of the valve.
Other, more sophisticated solutions have been the use of a differential fill valve. The differential fill valve allows filling of the tubular and circulation by utilizing the differential pressure between the inner and the outer annulus of the tubular. Typically, the prior art differential fill valve comprises a first and second flapper valve and a sleeve. The flapper valves are bias closed by a spring. The sleeve is secured in place by shear pins and is shiftable from a first to a second position. In operation, the differential fill valve is disposed on the end of the first string of tubular then inserted into the wellbore. During run-in the sleeve is in the first position, which prevents the second flapper valve from operating. As subsequent strings of tubulars are inserted into the wellbore the first flapper valve in the differential flow valve opens and closes based upon the differential pressure, thereby allowing wellbore fluid to enter the tubular string. The volume of wellbore fluid entering the tubular string is predetermined to achieve a differential height between the wellbore fluid inside the tubular annulus and the wellbore fluid outside the tubular. The amount of fluid entering the tubular through the flapper valve is controlled by a spring selected to bias the first flapper valve closed. The process of allowing a predetermined volume to enter the tubular is what is commonly called in the industry as differentially filling the tubular.
After the entire string of tubulars is disposed downhole, the differential fill capability of the valve is deactivated to change the valve into a one-way check valve. Typically, deactivation is accomplished by dropping a weighted ball from the surface down the wellbore either by free-fall or pumped in by a fluid mechanism allowing the ball to land into the sleeve. At a predetermined pressure the pins that secure the sleeve in the first position shear and the sleeve is shifted axially downward to a second position. In the second position, the sleeve closes the first flapper valve and subsequently allows the second flapper valve to operate. The deactivated differential fill valve functions as a standard float valve as described in the above paragraphs.
There are several problems associated with the prior art devices. One problem occurs while dropping the weighted ball to deactivate the differential fill feature in a deviated wellbore (deviations greater than 30 degrees from vertical). Typically, the ball is allowed to drop free-fall or pumped into a ball seat located in a sleeve. After the ball lands in the ball seat, drilling fluid is pressurized to act against the ball seat to shift the sleeve to a second position, thereby allowing a permanent check valve mechanism to engage. The reliability of actuating balls in a deviated wellbore greater than 30 degrees decreases as the deviation increases. Additionally, actuating balls in a horizontal, or near horizontal (70 to 90 degrees) well become ineffective in performing their required function, which leads to an inoperable downhole tool.
Another problem associated with the prior art devices arises when the tool is no longer needed to facilitate the injection of cement and must be removed from the wellbore. Rather than de-actuate the tool and bring it to the surface of the well, the tool is typically destroyed with a rotating milling or drilling device. Generally, the tool is “drilled up” or reduced to small pieces that are either washed out of the wellbore or simply left at the bottom of the wellbore. As in the case with the prior art devices that comprise of many metallic components numerous trips in and out of the wellbore are required to replace worn out mills or drill bits. This process is time consuming and results in lost productivity time.
Another problem with the prior art devices is the inability to operate in high downhole pressures and temperatures. Typically, as the depth of the wellbore increases both downhole pressure and temperature also increase. The prior art devices having a flapper valve design cannot operate effectively in pressures in excess of 3,000 PSI. Additionally, the prior art devices cannot function properly in downhole temperatures in excess of 300° F.
There is a need for a plunger-type check valve that can operate effectively in deviated wells or nearly horizontal wells. There is a further need for a plunger-type check valve that is made of composite components, thereby minimizing milling operation time upon removal of a valve and subsequently reduce the wear and tear on the drill bit. There is yet a further need for a plunger-type check valve that can operate effectively in high downhole pressures and high temperatures.
SUMMARY OF THE INVENTION
The present invention generally relates to a plunger-type valve for use in a wellbore. In one aspect, the plunger type check valve can operate effectively in deviated or nearly horizontal wells. In another aspect, the plunger-type check valve is made out of composite components, thereby minimizing milling operation time upon removal of a valve and subsequently reduce the wear and tear on the drill bit. In yet another aspect, the plunger-type check valve can operate effectively in high downhole pressures and high temperatures.
The plunger-type valve is arranged to selectively allow fluid to enter and exit the valve in both directions. The invention includes a body, at least one locking segment, a locking sleeve, at least one biasing member, a valve seat, and a plunger. In one direction, fluid enters an upper end of the body of the valve and urges the plunger downward, thereby allowing the fluid to exit the bottom of the valve body. In another direction, fluid enters the bottom of the valve body and urges the seat upwards, thereby allowing the fluid to flow to the upper end of the valve body.
In another aspect, the plunger-type valve may be deactivated to selectively allow fluid to flow in only one direction. At a predetermined maximum flow rate, the locking sleeve and the valve seat is urged axially downward. The locking segment moves radially inward to secure the locking sleeve in a fixed position. In turn, the valve seat moves axially downward to a predetermined point in the body. In this manner, both the locking sleeve and valve seat are restricted from axial movement. Consequently, fluid may only enter the top of the valve body and exit the bottom of the valve body by urging the plunger downward.
BRIEF DESCRIPTION OF THE DRAWINGS
So that the manner in which the above recited features and advantages of the present invention are attained and can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to the embodiments thereof 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 is a longitudinal cross-sectional view of one embodiment of a valve assembly at an end of a tubular in accordance with the present invention.
FIG. 2 is an enlarged cross-sectional view of the valve assembly in FIG. 1 .
FIG. 3 is a cross-sectional view of the valve assembly as the differential pressure moves the valve seat from the plunger to permit fluid to flow from the lower end to the upper end of the valve assembly.
FIG. 4 is a cross-sectional view of a valve assembly pumping fluid through the valve assembly without disengaging the differential fill feature.
FIG. 5 is a cross-sectional view of the valve assembly pumping fluid at a maximum flow rate to deactivate the differential fill feature.
FIG. 6 is a cross-sectional view of a deactivated valve assembly.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 is a longitudinal cross-sectional view of one embodiment of the valve assembly 100 at an end of a tubular 102 in accordance with the present invention. As illustrated, the valve assembly 100 is disposed in a float shoe housing 104 . It should be noted that the valve assembly 100 may also be used in a float collar arrangement, or any other configuration in which a plunger-type check valve is required in a downhole tool.
Typically, the wellbore 103 contains wellbore fluid that has accumulated during the drilling operation. As the tubular 102 is inserted in the wellbore 103 , the fluid is displaced into an annulus 106 created between wellbore 103 and the tubular 102 . As it is lowered into the wellbore, the tubular 102 encounters a buoyancy force that impedes its downward movement. The force increases as the tubular is lowered further. At a predetermined differential pressure between the pressure exerted against the tubular and the internal pressure of the tubular, the valve assembly 100 allows wellbore fluid to enter an interior 108 of the tubular 102 to relieve the buoyancy forces acting on the tubular 102 . The amount of wellbore fluid entering the tubular interior 108 is determined by a pre-selected differential height 109 between the wellbore fluid in the tubular interior 108 and the wellbore fluid in the annulus 106 . The differential height 109 is density dependant, therefore, the heavier the fluid the smaller the differential height 109 and the lighter the fluid the larger the differential height 109 . The valve assembly 100 will differentially fill the tubular 102 by cycling between open and close to maintain the pre-selected differential height 109 .
FIG. 2 is an enlarged cross-sectional view of the valve assembly 100 of FIG. 1 . The assembly 100 includes an upper housing 105 that is threadedly connected to a lower housing 120 . A retaining housing 130 is connected to the lower housing 120 at the lower end of the valve assembly 100 . The valve assembly 100 further includes a plurality of segments 110 radially spaced apart in the upper housing 105 . The upper end of the segment 110 is captured in a groove 107 in the upper housing 105 . The groove 107 is constructed to act as a pivot point for the segments 110 . A biasing member 165 is disposed at the lower end of each segment 110 to provide a means for locking the segments 110 in one position. Preferably, the biasing member 165 is a spring device wrapped radially around segments 110 to bias the segments 110 inward. Although the biasing member 165 is illustrated as an O-ring, it should be noted that the biasing member may include a garter spring, a series of C-rings, or any other device that produces a radial force. A locking shoulder 112 is formed at the lower end of the segment 110 .
A locking sleeve 170 may be disposed inside the segments 110 in the upper housing 105 . The locking sleeve 170 is axially movable between a first position and a lock position and contains a passageway 185 that fluidly connects to a passageway 180 in a valve seat 160 . A surface 172 is provided at the upper end of the locking sleeve 170 that is later used to secure the locking sleeve 170 in place. At the lower end of the locking sleeve 170 is an orifice 175 . The orifice 175 has a smaller inside diameter than the inside diameter of passageway 185 . As fluid flows through the passageway 185 and enters the orifice 175 , a differential pressure is created due to the restricted flow through the smaller inside diameter of the orifice 175 . This differential pressure provides a force required to axially translate the locking sleeve 170 downward. The inside diameter of the orifice 175 is based on the fluid density and flow rate through the orifice 175 .
At the lower end of the locking sleeve 170 are sleeve biasing members 115 . The sleeve biasing members 115 are disposed between the locking sleeve 170 and the valve seat 160 . In the preferred embodiment, the sleeve biasing members 115 are a plurality of disk shaped members such as wave springs or wave washers. However, a sealed volume of compressible fluid/gas or semi-solid compressible material such as an electrometric material, composite or plastic may be employed, so long as it is capable of biasing the locking sleeve 170 . In the preferred embodiment, the sleeve biasing members 115 are an annular member that bias the valve seat 160 and the locking sleeve 170 in opposite directions. Additionally, the sleeve biasing members 115 provide the biasing force (or backpressure force) against the valve seat 160 to control the amount of wellbore fluid entering the valve assembly 100 while differentially filling the tubular (not shown) to maintain a pre-selected differential height. The size and thickness of the sleeve biasing members 115 are selected based upon the desired differential height and the quantity of sleeve biasing members 115 is based upon the desired stroke length of the valve seat 160 .
The valve seat 160 is an annular member that includes passageway 180 at the upper end and an outwardly tapered portion 162 at the lower end. In FIG. 2, the valve seat 160 is shown in a run-in position. In the run-in position a seal member 155 arranged around the valve seat 160 abuts a shoulder 122 in the lower housing 120 . The seal member 155 functions to create a fluid tight seal between the valve seat 160 and the lower housing 120 . The value seal 160 may axially move between a retracted and a final extended position inside the lower housing 120 . While differentially filling a tubular, the valve seat 160 retracts or moves upward to create a fluid passageway between the bottom of the valve assembly 100 and the passageway 180 in the valve seat 160 thereby permitting fluid to enter tubular 102 (not shown) as illustrated in FIG. 3 .
A plunger 150 with a plunger head 190 and a shaft portion 195 is located at the lower end of the valve seat 160 . A sealing relationship is created between the plunger head 190 of the plunger 150 and the tapered portion 162 of the valve seat 160 . A biasing member in the form of a spring 145 is disposed about the plunger shaft 195 to urge the plunger 150 upward into contact with the valve seat 160 while the sleeve biasing members 115 urge the valve seat downward, thereby creating a sealing relationship. The upper end of the spring 145 is adjacent the plunger head 190 and the lower end of the spring 145 abuts a plunger housing 125 . The plunger housing 125 is disposed in the retaining housing 130 at the lower end of the valve assembly 100 . A retainer 140 is attached to the lower end of the plunger shaft 195 by a retainer screw 135 . In the preferred embodiment, the components of the valve assembly 100 are made out of a drillable, composite material.
FIG. 3 is a cross-sectional view of the valve assembly 100 as it is being lowered into the wellbore. In this position, differential pressure resulting from the differential height moves the valve seat 160 away from the plunger 150 to permit fluid to enter from the lower end of the valve assembly 100 . During differential filling of the tubular, wellbore fluid enters the lower portion of the valve assembly 100 and acts against the tapered section 162 of the valve seat 160 . When the differential pressure overcomes the backpressure created by the sleeve biasing members 115 on the valve seat 160 , the sleeve biasing members 115 compress, thereby allowing the valve seat 160 to move axially upward into the retracted position. The upward movement of the valve seat 160 disengages the sealing relationship between the plunger head 190 and the valve seat 160 , thereby creating a fluid passageway around the plunger 150 . Wellbore fluid, as illustrated by arrows 205 , may now enter the lower end of assembly 100 , flow around the plunger head 190 into the passageway 180 created in the valve seat 160 , move through the orifice 175 , and exit the top of the assembly 100 through the passageway 185 . As the differential pressure decreases, the sleeve biasing members 115 return to an un-compressed state, thereby allowing the valve seat 160 to sealingly contact the plunger head 190 as illustrated in FIG. 2 .
FIG. 4 is a cross-sectional view of the valve assembly 100 illustrating the passage of fluid from the tubular, through the assembly and into an annular area between the tubular and a wellborn (not shown). During a completion operation of a well, the wellbore may become clogged with particulates. In this situation, the wellbore needs to be pumped with high pressure fluid to clean out the wellbore prior to inserting another section of tubular. The valve assembly 100 is designed to allow fluid to flow through the valve assembly 100 at a flow rate less than a predetermined maximum flow rate to clean out the wellbore without disengaging the differential fill feature.
In one embodiment, fluid enters the valve assembly 100 at the upper end of the housing 105 as illustrated by arrows 210 . As the fluid 210 flows through the passageways 185 , 180 it acts against the plunger head 190 . When the fluid pressure on the plunger head 190 overcomes the load of the spring 145 , the plunger 150 moves downward compressing spring 145 against the plunger housing 125 . The movement of the plunger 150 disengages the sealing relationship between the plunger head 190 and the valve seat 160 , thereby opening a fluid passageway through the valve 100 . As the fluid pressures increases, the locking sleeve 170 , sleeve biasing members 115 , and the valve seat 160 move axially downward as a unit. As the fluid pressures increases further, the fluid acts on orifice 175 in the locking sleeve 170 . The force exerted by the fluid at the orifice 175 urges the locking sleeve 170 axially downward against the sleeve biasing members 115 . The force exerted on the locking sleeve 170 does not entirely overcome the biasing force of the sleeve biasing members 115 . Thus, the axial movement of locking sleeve 170 only partially exposes segments 110 at the upper end of the locking sleeve 170 . In turn, the sleeve biasing members 115 compress and act upon the valve seat 160 . The valve seat 160 moves axially downward returning to the run-in position wherein the seal member 155 abuts the shoulder in the housing. Alternatively, the locking sleeve 170 can be secured in the upper housing 105 by a shear pin (not shown), which allows the locking sleeve to be retained in the first position and avoid inadvertent movement of the locking sleeve 170 to the locked position. The shear pin is constructed to fail at a predetermined flow rate acting on the orifice 175 , thereby allowing the locking sleeve 170 to move axially downward toward the locked position.
FIG. 5 is a cross-sectional view of a valve assembly 100 pumping fluid at or above a maximum flow rate to deactivate the differential fill feature. The fluid, as illustrated by arrow 215 , initially enters the upper housing 105 in the valve assembly 100 . The fluid flows through the passageway 185 and acts upon the orifice 175 and exerts a force that urges the locking sleeve 170 axially downward. At the maximum flow rate, the locking sleeve 170 is urged sufficiently downward to completely expose segments 110 . Upon exposure of the segments 110 , the biasing member 165 causes the lower end of the segments 110 to move radially inward and the upper end to pivot in the groove 107 . As the segments 110 move radially inward the locking shoulder 112 wedges against surface 172 of the locking sleeve 170 , thereby preventing the locking sleeve 170 from moving axially upward in the valve assembly 100 .
As the locking sleeve 170 moves axially downward, it also compresses the sleeve biasing members 115 against the seat 160 . The force on the seat 160 by the sleeve biasing members 115 causes the seat 160 to move axially downward until the bottom of the seat 160 hits a stop 220 in the lower housing 120 . The fluid, as illustrated by arrow 215 , continues through the passageway 180 and acts upon the plunger head 190 of the plunger 150 thereby causing the plunger 150 to move axially downward. As the plunger 150 moves downward a fluid passageway is created through the valve assembly 100 and the spring 145 is compressed against the plunger housing 125 . The fluid flows around the plunger 150 and exits the retainer housing 130 . The locking sleeve 170 and the seat 160 are secured in a fixed position by the segments 110 at the upper end of the locking sleeve 170 and the stop 120 at the lower end of the valve seat 160 .
FIG. 6 is a cross-sectional view of a deactivated valve assembly 100 . As illustrated, the segments 110 are wedged against the locking sleeve 170 . The locking sleeve compresses the sleeve biasing members 115 against the valve seat 160 , securing the valve seat 160 in a final extended position. While in the final extended position the taper portion 162 of the valve seat 160 creates a sealing relationship with the plunger head 190 .
After the section of tubular is installed in the wellbore, the tubular is typically anchored in the wellbore through a cementing process. The valve assembly 100 is used to facilitate the passage of cement from the tubular to the annulus of the well while preventing cement from returning into the tubular due to gravity and fluid density of the cement. The valve assembly 100 acts as a standard one-way check valve allowing fluid to enter the upper housing 105 into the passageway 185 through the orifice 175 into the passageway 180 and act upon the plunger head 190 . At a predetermined flow rate, the plunger 150 moves axially downward and compresses the spring 145 disposed around the shaft 195 of the plunger 150 . The downward movement of the plunger 150 disengages the seal connection between the plunger head 190 and the valve seat 160 to create a passageway around the plunger 150 . The fluid is allowed to flow through the passageway and exit the bottom of the valve assembly 100 . After the downward flow is stopped, the plunger 150 moves axially upward due to the force of the spring 145 and the plunger head 190 creates a sealing relationship with seat 160 , thereby preventing fluid from returning into the valve assembly 100 from the wellbore.
In another embodiment, a mechanical device, such as a weighted ball (not shown) can be dropped and seated on a ball seat. Pressure application will then slide the locking sleeve 170 to a predetermined distance to deactivate the differential fill feature. In this embodiment, cross-ports are placed above the mechanical device to allow fluid flow pass the device and through the valve.
In operation, the valve assembly 100 is disposed at the lower end of a tubular 102 and then the tubular is run into a wellbore. At a predetermined differential pressure, the valve assembly 100 allows wellbore fluid to enter the tubular. The amount of wellbore fluid allowed to enter the tubular is determined by a pre-selected differential height between the wellbore fluid inside the tubular and the wellbore fluid in the annulus between the tubular and the wellbore. The valve assembly 100 will differentially fill the tubular by cycling between an open and closed position to maintain the pre-selected differential height until the entire section of tubing is disposed in the wellbore.
During differential filling of the tubular, fluid enters the lower portion of the valve assembly 100 and acts against the valve seat 160 . Specifically, the differential pressure overcomes the backpressure created by the sleeve biasing members 115 on the valve seat 160 , thereby allowing the valve seat 160 to move axially upward into the retracted position. The upward movement of the valve seat 160 disengages the sealing relationship between the plunger head 190 and the valve seat 160 . Wellbore fluid may now enter the lower end of assembly 100 , flow around the plunger head 190 into the passageway 180 created in the valve seat 160 , flow through the orifice 175 , and exit the top of the assembly 100 through the passageway 185 . As the differential pressure decreases, the sleeve biasing members 115 return to an un-compressed state, thereby allowing the valve seat 160 to sealingly contact the plunger head 190 .
During a completion operation of a well, the wellbore may become clogged with particulates. In this situation, the wellbore needs to be pumped with high pressure fluid to clean out the wellbore prior to inserting another section of tubular. The valve assembly 100 is designed to allow fluid to flow through the valve assembly 100 at a flow rate less than a predetermined maximum flow rate to clean out the wellbore. Fluid enters the valve assembly 100 at the upper end of the housing 105 . Subsequently, the fluid flows through the passageway 185 and acts against the orifice 175 in the locking sleeve 170 . The force exerted by the fluid at the orifice 175 urges the locking sleeve 170 axially downward against the sleeve biasing members 115 . The sleeve biasing members 115 compress and act upon the valve seat 160 . The valve seat 160 moves axially downward returning to the run-in position. Fluid crossing the orifice enters the passageway 180 it exerts a downward pressure on the plunger head 190 . When the fluid pressure on the plunger head overcomes the load of the spring 145 , the plunger 150 moves downward. The movement of the plunger 150 disengages the sealing relationship between the plunger head 190 and the valve seat 160 , thereby opening a fluid passageway through the valve 100 .
Once the section of tubular is completely placed in the wellbore, fluid is pumped at or above a maximum flow rate to deactivate the differential fill feature. The fluid, initially enters the upper housing 105 in the valve assembly 100 . The fluid flows through the passageway 185 and acts upon the orifice 175 and exerts a force that urges the locking sleeve 170 axially downward. At the maximum flow rate, the locking sleeve 170 is urged sufficiently downward to completely expose segments 110 . Upon exposure of the segments 110 , the biasing member 165 causes the lower end of the segments 110 to move radially inward and the upper ends to pivot in the groove 107 . As the segments 110 move radially inward the locking shoulder 112 wedges against surface 172 of the locking sleeve 170 , thereby preventing the locking sleeve 170 from moving axially upward in the valve assembly 100 .
As the locking sleeve 170 moves axially downward it also compress the sleeve biasing members 115 against the seat 160 . The force on the seat 160 by the sleeve biasing members 115 causes the seat 160 to move axially downward until the bottom of the seat 160 hits a stop 220 in the lower housing 120 . The locking sleeve 170 and the seat 160 are secured in a fixed position by the segments 110 at the upper end of the locking sleeve 170 and the stop 220 at the lower end of the valve seat 160 .
After the section of tubular is installed in the wellbore, the tubular is typically anchored in the wellbore through a cementing process. The valve assembly 100 is used to facilitate the passage of cement from the tubular to the annulus of the well while preventing cement from returning into the tubular due to gravity and fluid density of the cement. The valve assembly 100 acts as a standard one-way check valve allowing fluid to enter the upper housing 105 into the passageway 185 through the orifice 175 into the passageway 180 and act upon the plunger head 190 . At a predetermined flow rate, the plunger 150 moves axially downward and compresses the spring 145 disposed around the shaft 195 of the plunger 150 . The fluid is allowed to flow through the passageway and exit the bottom of the valve assembly 100 . After the downward flow is stopped, the plunger 150 moves axially upward and the plunger head 190 creates a sealing relationship with seat 160 , thereby preventing fluid from returning into the valve assembly 100 from the wellbore.
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.
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The present invention generally relates to a plunger-type valve for use in a wellbore. The plunger-type valve is arranged to selectively allow fluid flow to enter and exit the valve in both directions. Subsequently, the plunger-type valve can be deactivated to selectively allow fluid flow in only one direction. The valve includes a body, at least one locking segment, a locking sleeve, at least one biasing member, a valve seat and a plunger.
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FIELD OF THE INVENTION
This invention relates to chemical reactors for the conversion of a reaction fluid while indirectly exchanging heat with a heat exchange fluid.
BACKGROUND OF THE INVENTION
In many industries, like the petrochemical and chemical industries for instance, the processes employ reactors in which chemical reactions are effected in the components of one or more reaction fluids under given temperature and pressure conditions. Many of these reactions generate or absorb heat, to various degrees, and are, therefore, exothermic or endothermic. The heating or chilling effects associated with exothermic or endothermic reactions can positively or negatively affect the operation of the reaction zone. The negative effects can include among other things: poor product production, deactivation of the catalyst, production of unwanted by-products and, in extreme cases, damage to the reaction vessel and associated piping. More typically, the undesired effects associated with temperature changes will reduce the selectivity or yield of products from the reaction zone.
One solution for controlling the changes in temperature associated with the heats of various reactions has been to operate several adiabatic reaction zones with intermediate heating or cooling between the different reaction zones. In each adiabatic reaction stage, all of the heat liberated or absorbed during the reaction is transmitted directly to the reactive fluid and the reactor internals. The degree of heat release and the tolerance for temperature change determines the total number of adiabatic reactor zones required in such arrangements. Each zone or adiabatic stage of reaction adds significantly to the overall cost of such a process due to the equipment expense of adding piping and heaters or coolers for intermediate stages of heat transfer to a reactant that passes through the reaction zones. Therefore the number of adiabatic steps is limited and such systems offer at best a stepwise approach to isothermal or other controlled temperature conditions. Moreover, the breaking up of a reaction zone into a series of reactors with intermediate heating or cooling of reactants, especially interferes with reactor arrangements that have continual addition and withdrawal of catalyst from the reaction zone.
Other solutions to the problem of temperature control under the influence of different heats of reaction have employed direct or indirect heating or cooling within the reaction zone. Direct heating or cooling utilizes a compensating reaction having a directionally different heat requirement that occurs simultaneously with the principal reaction. The counter balancing reaction offsets heat release or heat adsorption from the principal reaction. One of the simplest forms of such an arrangement is an endothermic process that uses oxidation of hydrogen to heat reactants in an endothermic reaction.
Another solution has been the indirect heating of reactants and/or catalysts within a reaction zone with a heating or cooling medium. The most well known catalytic reactors of this type are tubular arrangements that have fixed or moving bed catalysts. The geometry of tubular reactors poses layout constraints that require large reactors or limit throughput.
Indirect heat exchange has also been accomplished using thin plates to define channels that alternately retain catalyst and reactants between a heat transfer fluid for indirectly heating or cooling the reactants and catalysts. Heat exchange plates in these indirect heat exchange reactors can be flat or curved and may have surface variations such as corrugations to increase heat transfer between the heat transfer fluids and the reactants and catalysts. Although the thin heat transfer plates can, to some extent, compensate for the changes in temperature induced by the heat of reaction, the indirect heat transfer arrangements are not able to offer the complete temperature control that would benefit many processes by maintaining a desired temperature profile through a reaction zone.
Many hydrocarbon conversion processes will operate more advantageously by maintaining a temperature profile that differs from that created by the heat of reaction. In many reactions, the most beneficial temperature profile will be obtained by substantially isothermal conditions. In some cases, a temperature profile directionally opposite to the temperature changes associated with the heat of reaction will provide the most beneficial conditions. An example of such a case is in dehydrogenation reactions wherein the selectivity and conversion of the endothermic process is improved by having a rising temperature profile, or reverse temperature gradient through the reaction zone.
A reverse temperature gradient for the purposes of this specification refers to a condition where the change in temperature through a reaction zone is opposite to that driven by the heat input from the reaction. In an endothermic reaction, a reverse temperature gradient would mean that the average temperature of the reactants towards the outlet end of the reaction zone have a higher value than the average temperature of the reactants at the inlet end of the reaction zone. In an opposite manner, a reverse temperature gradient in an exothermic reaction refers to a condition wherein reactants towards the inlet end of the reactor have a higher average temperature than the reactants as they pass toward the outlet end of the reaction section.
It is an object of this invention to provide a reactor that offers greater temperature control of reactants by the indirect heating or cooling of a reaction stream by a heat exchange fluid within a reaction zone.
It is a further object of this invention to provide a process and apparatus used for indirect heat exchange of a reactant stream with a heat exchange stream for controlling the temperature profile through the reaction zone.
Another object of this invention is to provide a process that uses indirect heat exchange with a heat exchange fluid to maintain substantially isothermal conditions or a reverse temperature gradient through a reactor.
BRIEF SUMMARY OF THE INVENTION
This invention is a chemical reactor and a process for using a chemical reactor that employs an arrangement of heat exchange plates within the reactor that will maintain reactor temperatures within a desired range during the reaction. The heat exchange plates define alternate channels for the heat exchange fluid and the reactants. Heat transfer is controlled in this invention by locating a heat transfer adjustment plate in the center of channels that convey a heat transfer fluid through the reactor. The adjustment plate defines protrusion that extend into the heat transfer channels and reduce or increase turbulence with the channel. Raising or lowering the turbulence in the heat exchange channel increases or decreases the heat transfer coefficient across the heat exchange plates that separate the reactant channels from the heat transfer channels. In this manner the degree of indirect heat exchange along the length of the reactor can be adjusted to maintain a desired temperature profile.
The heat adjustment plate is susceptible to a variety of configurations. The only essential requirement is that the plate have a surface that creates a varied amount of turbulence as the heat transfer fluid contacts different portions of the plate. The plate can induce variations in turbulence by changing the surface roughness over different portions of the plate, using a varied number and size of a perforations over the plate. The more effective arrangements of this invention use the adjustment plate to define protrusions that extend from the plate and project into the flow path of the heat exchange fluid.
The number, shape and amount of protrusions can be adjusted over the surface of the plate to provide the desired degree of temperature adjustment within the reactant channels. For example in an endothermic reaction more or larger protrusions are provided in the heat exchange channels that heat the portion of the reactant channels located toward the outlet of the reactor. The increased number of protrusions toward one end of the reactor selectively increases heat exchange at the outlet end of the reactant channels and provides the necessary heat input to maintain a constant temperature throughout the reactant channels. The number of protrusions provided over the plate can be adjusted as needed to suit the endothermicity or exothermicity of the reaction occurring in the reactant channels.
This invention will promote the control of temperatures through a reaction zone. Preferably this invention will maintain the desired inlet and outlet temperatures within 10° F. and more preferably within 5° F. of a desired temperature profile through the reactant channels. Where isothermal conditions are desired the inlet and outlet temperature are equal, such that one requirement of the substantially isothermal conditions described in this invention is that the mean inlet and outlet temperature vary by no more than 10° F. and preferably by no more than 5° F.
A process and catalyst reactor arrangement that uses this invention may employ single or multiple reaction zones within a reactor vessel. The advantage of this invention is that the reactor vessel can provide the desired temperature gradient without intermediate withdrawal and recycling of reactants or heat exchange medium between the inlet and outlet of the reactor. The multiple reaction zones within the reactor vessel can be used to accommodate variations in the heat adjustment plate.
Accordingly, in an apparatus embodiment, this invention is a reactor for controlling temperature profiles in a reaction zone. The reactor includes a plurality of spaced apart heat exchange plates. Each heat exchange plate has an extended length and defines a boundary of a heat exchange flow channel on one side of the plate and a boundary of a reaction flow channel on an opposite side of the plate. Means are provided for passing a reaction fluid along through a plurality of the reaction flow channels defined by the plates along a first flow path and means are provided for passing a heat exchange fluid through a plurality of the heat exchange channels defined by the plates along a second flow path. A heat adjustment plate in each heat exchange channel define a plurality of protrusions that project into the heat exchange channels. The protrusions have an area of projection into the heat exchange flow channel that varies over the length of the plate to produce varied turbulence across the channels. Preferably each heat exchange plate defines corrugations and the heat adjustment plate is sandwiched between the corrugations in the heat exchange channel.
In another embodiment, this invention is a process for controlling the temperature of a reactant stream in a chemical reaction by indirect heat exchange with a heat exchange fluid across a multiplicity of plate elements. The process comprises passing a heat exchange fluid from a heat exchange inlet to a heat exchange outlet through a first set of elongated channels formed by a first side of a plurality of heat exchange plates. A reactant stream passes from a reactant inlet to a reactant outlet through a second set of channels formed by a second side of the heat exchange plates. The process exchanges heat between the heat exchange fluid and the reactant stream by contacting the heat exchange fluid with corrugations formed by the heat exchange plates. In addition to the corrugations the heat exchange fluid in the heat exchange channels contacts a heat adjustment plate that contains a plurality of protrusions to vary the heat transfer coefficient within the heat transfer channels.
The process may be useful in a wide variety of catalytic reactions. This invention is most beneficially applied to catalytic conversion process having high heats of reaction. Typical reactions of this type are hydrocarbon conversion reactions that include: the aromatization of hydrocarbons, the reforming of hydrocarbons, the alehydrogenation of hydrocarbons, and the alkylation of hydrocarbons. Specific hydrocarbon conversion processes to which this invention are suited include: catalytic dehydrogenation of paraffins, reforming of naphtha feed streams, aromatization of light hydrocarbons and the alkylation of aromatic hydrocarbons.
The reaction zones for the process of this invention may indirectly contact the reactants with the heat exchange fluid in any relative direction. Thus, the flow channels and inlet and outlets of the reaction zones may be designed for cocurrent, countercurrent, or crossflow of reactant and heat exchange fluid. Preferred process arrangements for practicing this invention will pass reactants in cross-flow to the heat exchange fluid. Cross-flow of reactants is generally preferred to minimize the pressure drop associated with the flow of reactants through the reactor. For this reason, a cross-flow arrangement can be used to provide the reactants with a shorter flow path across the reaction zone.
Effective use of the adjustment plate in a cross-flow arrangement of reactants and heat exchange fluids requires attention to pressure drop considerations. Changing the heat transfer along the path of the reactant stream requires a variation in the protrusions along a path transverse to the flow of the heating medium. Increasing the size or number of protrusions on one side of the heat exchange channels to increase heat transfer can increase the resistance to flow through the same portion of the channel. Increased flow resistance and resulting pressure drop can redistribute fluid flow across the channel and redirect a greater flow of heat exchange fluid back to the portion of the heat exchange channels where less heating is desired. If not considered in the design of the channels or heat adjustment plate this increased flow will increase heat transfer and undo the effect of the increased protrusions. Accordingly in a cross-flow arrangement the protrusions should increase turbulence without adversely redistributing the flow of heat exchange fluid with increased pressure drop. Increasing turbulence independent of pressure drop may be accomplished by adjusting the shape and configuration of the protrusions. Heat transfer is effectively enhanced by using protrusions that direct the heat exchange fluid into impact with surfaces of the channels and heat transfer plates. Turbulence and pressure drop may be decoupled by using protrusions that maximize the redirection and impact of the heat exchange fluid with plate surfaces at one end of the heat exchange channel and using protrusion that maintain pressure drop without redirection at the other end of the channel. The incorporation of perforations in the protrusions provides another method of increasing turbulence and without raising pressure drop.
The shorter flow path, particularly in the case of the reactant stream contacting heterogeneous catalysts, reduces overall pressure drop of the reactants as they pass through the reactor. Lower pressure drops can have a two-fold advantage in the processing of many reactant streams. Increased flow resistance i.e., pressure drop, can raise the overall operating pressure of a process. In many cases, product yield or selectivity is favored by lower operating pressure so that minimizing pressure drop will also provide a greater yield of desired products. In addition, higher pressure drop raises the overall utility and cost of operating a process.
It is also not necessary to the practice of this invention that each reactant channel contain only one heat adjustment plate. Possible configurations of the reaction section may place two or more heat adjustment plates within each reactant channel to offer greater control to turbulence within a channel.
Additional embodiments, arrangements, and details of the invention are disclosed in the following detailed description of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic representation of a catalytic reaction section of this invention showing a preferred direction for the circulation of fluids and catalyst.
FIG. 2 is a side view of the catalytic reaction section taken along lines 2--2 of FIG. 1.
FIG. 3 is a top view of the reactor section of FIG. 1 taken along lines 3--3.
FIG. 4 is a section of the reaction system shown in FIG. 1 taken along line 4--4 of FIG. 3.
FIG. 5 is a section of a heat adjustment plate of this invention.
FIG. 6 is a section of the channels formed by corrugated plates containing the heat adjustment plate of this invention.
FIG. 7 is a perspective view of the channels and heat adjustment plate shown in FIG. 6.
DETAILED DESCRIPTION OF THE INVENTION
By its very design, the reactor according to this invention has the advantage of maintaining, with simple means, desired temperature profiles including isothermal or reverse gradient temperature conditions during the flow of the reactive fluid in the reactor, by means of a heat transfer medium. This invention aids in the effective use of catalytic materials by controlling temperatures in a manner that enhances performance of the catalytic reaction.
The process and reactor arrangement may use homogeneous or heterogeneous catalysts. Homogeneous catalyst will typically comprise liquid catalysts that flow through reaction channels along with the reactants and are separated for recovery and recycle outside of the reaction zone. This reactor arrangement provides particular benefits with heterogeneous catalysts that are typically retained within the reactant channels by the corrugated plates and permeable members that retain the catalyst but permit the flow of reactants therethrough. In most cases, the heterogeneous catalyst will comprise particulate material retained between the plates and the reactor may be arranged to permit the continuous addition and withdrawal of particulate material while the reactor is on stream.
The type and details of the reactor arrangements contemplated in the practice of this invention is best appreciated by a reference to the drawings. FIG. 1 is a schematic representation of a catalytic reactor section 10 designed to effect a catalytic reaction on a reactant fluid while using indirect heat exchange with a heat transfer fluid to maintain favorable reaction temperatures as the reactant fluid flows through the catalytic reaction section. The catalytic reaction section comprises a stack of heat exchange plates 17 of the type represented in FIGS. 2 and 3. Each plate 17 is stacked in a spaced apart relationship next to adjacent plates 17 to form two circulation systems, the first one for a flow of a reactive fluid 12 and the second one for flow of heat exchange fluid 14. When present a flow of catalyst 16 will also pass through the first circulation system. Together FIGS. 1 through 3 define a specific circulation system, wherein the reactive fluid and the heat exchange fluid respectively, flow in crosswise directions, i.e. perpendicular and through alternate channels formed between adjacent plates 17. In FIG. 1, a reactant fluid passes horizontally in the direction indicated by arrows 12. The heat exchange fluid flows transversely to the reactant fluid in the direction indicated by arrows 14. Catalyst also passes through the reactant channels with the reactants in the direction and at a location indicated by arrows 16. FIG. 2 shows via a side view, the arrangement of alternate heat exchange channels 18 and reactant channels 20 formed by the plurality of heat exchange plates 17. Reactant channels 20 are open at the edge of the reactor to isolate the reactant channels from the heat exchange channels. Where the reactant channels also contain a particulate catalyst material, a suitable screen covers the open sides of reactant channels 20 to retain the catalyst. The sides of heat exchange channels 18 are sealed to confine the heat exchange fluid for vertical flow through the reaction section. FIG. 2 also shows the heat adjustment plate 11 as dashed line centered in the closed off heat exchange channels. The heat exchange plates preferably define continuous channels for both the reactant and the heat exchange fluid over the length and width of the reaction section. The continuous heat exchange channels maintain the heat exchange fluid in contact with the heat adjustment plate over the length of the reaction section.
The same alternate arrangement of heat exchange channels and reactant channels is shown in FIG. 3. As indicated by FIG. 3, the outer ends 19 of the heat exchange channels 18 are open to admit fluid into the heat exchange channels. The outer section 24 of reactant channels 20 are closed off to keep the heat exchange fluid out of the reactant channels. A partition 21 separates the central portion of heat exchange and reactant channels from the outer ends. Inside partition 21 the central portion of heat exchange channels 18 are closed to fluid flow. Closing the center of heat exchange channels 18 permits the center section of the reaction section to receive a particulate catalyst and distribute the catalyst to the open central portion 20 of reactant channels 20. Thus, catalyst passing vertically through the reactant channels enters the reaction section through the central portion 22 of the reactant channels. The vertically flowing reactants and catalyst exit the reaction section through a similar arrangement at the bottom of the reaction section. As shown in FIG. 4, central portion 22 of the reactant channels distributes catalyst to a series of baffles 26 that distribute the catalyst to the reactant channels. A series of baffles 28 at the bottom of reaction section 10 channel catalyst to a central portion 23 of the reactant channels for the withdrawal of catalyst from reaction section 10.
As depicted in FIG. 4, plates 17 preferably have a corrugated surface creating peaks 30 and valleys 32 that separate reactant channels 22 as well as heat exchange channels 18 into subchannels. In a yet further preferred form of this invention, the corrugations of plate 17 may have a varied pitch that further alters heat transfer coefficients down the length of the reactor to provide additional adjustment in the degree of heating or cooling provided by the indirect heat exchange.
Suitable heat exchange plates for this invention will comprise any plates allowing a high heat transfer rate and which are easily secured into a reaction section in a stable configuration that readily retains the heat transfer adjustment plate. The plates may be formed into curves or other configurations, but flat plates are generally preferred for stacking purposes. Thin plates are preferred and typically have a thickness of from 1 to 2 mm. The plates are typically composed ferrous or non-ferrous alloys such as stainless steels.
As depicted in FIG. 4 the preferred form of the invention will a corrugated plate arrangement. The corrugated plates are particularly useful in positioning the heat adjustment plate. Adjacent corrugations are arranged in an alternating pattern so that the peaks of the corrugations contact where the corrugation patterns cross to maintain the spacing between the plates and define an intersecting pattern of diagonal channels. In this manner the general herring bone pattern on the faces of opposing corrugated plates will extend in opposite directions and the opposing plate faces may be placed in contact with each other to form the flow channels and provide structural support to the plate sections.
As shown in FIG. 4 the corrugations may be varied to effect further control of the heat transfer coefficient between the across the heat exchange plates. The variation in the pitch of the corrugations further assists in maintaining a desired temperature profile through the reaction section. The plate arrangement of FIG. 4 represents a typical corrugation pattern for an exothermic or endothermic process. At the upper inlet end the pitch angle of the corrugations is small, i.e. the principle direction of the corrugations approach a parallel alignment with the heat exchange fluid flow. At the lower end of the plate where the heat exchange fluid exits, the pitch angle of the corrugations is wide to increase relative heat transfer, i.e. the principle direction of the corrugations approach a perpendicular or transverse alignment with respect to the heat exchange fluid flow. Corrugation pitch angles can be in a range of from greater than 0° to less than 90° degrees. Typically the corrugation pitch angle from an inlet to an outlet section of a plate will range from about 10° to 80°, and more typically in a range of about 15° to 60°. In a particularly preferred arrangement, the plates will make an angle of less than 30° at the inlet end of the plate and an angle of more than 35° at the outlet end of the plate. The varying corrugations may be formed in a continuous plate section or the plate section of the type shown in FIG. 4 may be made from several plates having corrugations at different pitch angles.
Preferably the reactant channels in which the reactant fluid circulates, includes a heterogenous catalyst in the form of particles. The catalyst particles typically comprise grains of a small size. The particles may take on any kind of shape, but usually comprise small spheres or cylinders.
When flowing through reactant channels 20, the reactant fluid undergoes a catalytic reaction accompanied by a liberation or an absorption of heat. The function of the heat exchange fluid circulating in the heat exchange channels is to convey the heat to be added to or removed from the reactant fluid, in order to maintain favorable reaction conditions. Such conditions can again include isothermal conditions during the circulation of the afore-mentioned reactive fluid in the catalytic reactor or a reverse temperature gradient. The heat exchange fluid is either a gas or a liquid, depending on the specific operating conditions of each process.
The specific heat transfer relationship for the plate exchange is established by the fundamental equation expressing heat transfer between two fluids. This relationship is as follows:
P=h×S×LMTD
where:
P is the amount of heat exchanged, h is the local or overall heat transfer coefficient, S is the heat exchange area between fluids, and LMTD is the logarithmic mean temperature difference.
The logarithmic mean temperature difference is readily determined by the desired temperature difference at any point along the plate.
For a series of corrugated plates defining alternate channels of catalyst particles and heat exchanger fluid, the local or overall heat transfer coefficient can be calculated by using the following equation:
h=f(a,e,dp)
where a is the pitch angle of the corrugations, e is the distance between two plates 17, and dp is the equivalent diameter of catalyst particles.
Appropriate values of h can be established by modeling or computed using known correlations for establishing heat transfer coefficients over corrugated surfaces and, where present, through particle beds. Correlations for localized heat transfer through particle beds may be found in Leva, Ind. Eng. Chem., 42, 2498 (1950). Correlations for heat transfer along corrugations are presented in AIChE Symposium Series No. 295 Vol. 89 Heat Transfer Atlanta (1993).
The area of exchange between the reactive fluid and the auxiliary fluid can be calculated by using the equation:
S=ε×n×1×L
where: ε is a correction factor for the elongation of the plates resulting from the corrugations, n is the number of plates in contact with both heating and reactant fluids, l is the plate width, and L is the plate length.
By varying the number of plates and the characteristics of the corrugations, especially the pitch angle of the corrugations, the corrugations provide means for maintaining desired temperature conditions in the reactant fluid flow direction.
In addition to control of heat transfer coefficients offered by the heat exchange plates, the primary mechanism taught by this invention for controlling heat transfer between the heat transfer channels and the reactant channels is the heat transfer adjustment plate 11. The function of the heat transfer adjustment plate is to vary the turbulence of the heat exchange fluid passing through the heat transfer channels. The plate is formed or retains elements on its surface that are irregular in shape and induce the desired degree of turbulence at specific locations in the heat transfer channels. The configuration of the irregularities for inducing turbulence can take on a variety of different shapes. Typically, the irregularities will be in the form of protrusions that will project outwardly from the plate into the flow path of the heat exchange fluid. As the heat exchange fluid contacts the projecting protrusions, turbulence is raised and heat transfer between the fluid and the surface of the heat transfer plate is increased. The change in the heat transfer coefficient at a given location of the channels by the increased degree of turbulence is readily calculated by methods well known to those skilled in the art. Accordingly, the variation in the heat transfer coefficient achieved by the pattern of surface irregularities on the heat transfer adjustment plate can be readily calculated or determined experimentally.
In a preferred form of the invention, the surface irregularities are formed by punching laterally extending tabs from the heat adjustment plate material and bending the tabs into the flow path of the heat exchange fluid. FIG. 5 shows a heat adjustment plate 11 from which tabs 34 have been bent outwardly. Adjustment of the turbulence induced by the tabs can be varied by changing the projection of the tabs into the flow path of the heat exchange fluid or increasing the number of tabs in portions of the heat exchange channels where additional heat transfer is desired.
FIG. 6 depicts a typical cross-section of a corrugated heat exchange channel containing a heat adjustment plate of the type depicted in FIG. 5. The corrugation peaks of heat exchange plate 17 retains heat adjustment plate 11 in a sandwich configuration. Heat adjustment plate 11 generally crosses through the center of heat adjustment channels 18. Heat adjustment tabs 34 occupy a central portion of the heat adjustment channel 18. Preferably heat adjustment tabs 34 will not contact the heat adjustment plate 17. Suitable heat adjustment plates can have an imperforate surface to prevent exchange of heat transfer fluid across the heat adjustment plate. Preferably, the heat adjustment plate will have perforations associated with the protrusions to permit passage of the heat exchange fluid across the heat adjustment plate. FIG. 6 also shows a preferred form for the tabs where alternate tabs project away from opposite sides of heat adjustment plate 11. FIG. 7 depicts a three dimensional arrangement of the channels and heat adjustment plate shown in FIG. 6.
Heat adjustment plate 11 will preferably comprise a thin plate having a thickness similar to that of the heat transfer plates. The heat adjustment plate operates in two ways to provide additional heat transfer across the heat exchange plates. Increased turbulence from the protrusions on the heat adjustment plate will indirectly increase heat transfer between the heat transfer fluid and the heat transfer plate. In addition, heat and adjustment plate 11 provides an additional surface for direct conduction of heat from the heat transfer fluid to the adjustment plate and from the adjustment plate to the points of contact with the heat transfer plates.
This invention may be particularly useful in many hydrocarbon conversion processes. Catalytic reforming is one such well established hydrocarbon conversion process employed in the petroleum refining industry for improving the octane quality of hydrocarbon feedstocks, the primary product of reforming being motor gasoline. The art of catalytic reforming is well known and does not require extensive description herein. Briefly, in catalytic reforming, a feedstock is admixed with a recycle stream comprising hydrogen and contacted with catalyst in a reaction zone. The usual feedstock for catalytic reforming is a petroleum fraction known as naphtha and having an initial boiling point of about 180° F. (80° C.) and an end boiling point of about 400° F. (205° C.). The catalytic reforming process is particularly applicable to the treatment of straight run gasoline comprised of relatively large concentrations of naphthenic and substantially straight chain paraffinic hydrocarbons, which are subject to aromatization through dehydrogenation and/or cyclization reactions. Reforming may be defined as the total effect produced by alehydrogenation of cyclohexanes and dehydroisomerization of alkylcyclopentanes to yield aromatics, alehydrogenation of paraffins to yield olefins, dehydrocyclization of paraffins and olefins to yield aromatics, isomerization of n-paraffins, isomerization of alkylcycloparaffins to yield cyclohexanes, isomerization of substituted aromatics, and hydrocracking of paraffins. Further information on reforming processes may be found in, for example, U.S. Pat. No. 4,119,526 (Peters et al.); 4,409,095 (Peters); and 4,440,626 (Winter et al), the contents of which are herein incorporated by reference.
A catalytic reforming reaction is normally effected in the presence of catalyst particles comprised of one or more Group VIII noble metals (e.g., platinum, iridium, rhodium, palladium) and a halogen combined with a porous carrier, such as a refractory inorganic oxide. The halogen is normally chlorine. Alumina is a commonly used carrier. The preferred alumina materials are known as the gamma, eta and the theta alumina with gamma and eta alumina giving the best results. An important property related to the performance of the catalyst is the surface area of the carrier. Preferably, the carrier will have a surface area of from 100 to about 500 m 2 /g. The particles are usually spheroidal and have a diameter of from about 1/16th to about 1/8th inch (1.5-3.1 mm), though they may be as large as 1/4th inch (6.35 mm). A preferred catalyst particle diameter is 1/16th inch (3.1 mm). During the course of a reforming reaction, catalyst particles become deactivated as a result of mechanisms such as the deposition of coke on the particles; that is, after a period of time in use, the ability of catalyst particles to promote reforming reactions decreases to the point that the catalyst is no longer useful. The catalyst must be reconditioned, or regenerated, before it can be reused in a reforming process.
In preferred form, the reforming operation will employ a moving bed reaction zone and regeneration zone. The present invention is applicable to moving bed and fixed bed zones. In a moving bed operation, fresh catalyst particles are fed to a reaction zone by gravity. Catalyst is withdrawn from the bottom of the reaction zone and transported to a regeneration zone where a multi-step regeneration process is used to recondition the catalyst to restore its full reaction promoting ability. Catalyst flows by gravity through the various regeneration steps and then is withdrawn from the regeneration zone and furnished to the reaction zone. Movement of catalyst through the zones is often referred to as continuous though, in practice, it is semicontinuous. By semi-continuous movement is meant the repeated transfer of relatively small amounts of catalyst at closely spaced points in time. A moving bed system has the advantage of maintaining production while the catalyst is removed or replaced.
Another preferred hydrocarbon conversion process is the alkylation of aromatic hydrocarbons. In aromatic alkylation suitable aromatic feed hydrocarbons for this invention include various aromatic substrates. Such substrates can be benzene or alkylated aromatic hydrocarbons such as toluene. The acyclic feed hydrocarbon or alkylating agent that may be used in the alkylation reaction zone also encompasses a broad range of hydrocarbons. Suitable alkylating agents include monoolefins, diolefins, polyolefins, acetylenic hydrocarbons and other substituted hydrocarbons but are preferably C 2 -C 4 hydrocarbons. In the most preferred form of this invention, the alkylation agent will comprise C 2 -C 4 monoolefms.
A wide variety of catalysts can be used in the alkylation reaction zone. The preferred catalyst for use in this invention is a zeolite catalyst. The catalyst of this invention will usually be used in combination with a refractory inorganic oxide binder. Preferred binders are alumina or silica. Preferred alkylation catalysts are a type Y zeolite having an alumina or silica binder or a beta zeolite having an alumina or silica binder. The zeolite will be present in an amount of at least 50 wt. % of the catalyst and more preferably in an amount of at least 70 wt. % of the catalyst.
The alkylation reaction zone can operate under a broad range of operating conditions. Temperatures usually range from 100° C. to 325° C. with the range of about 150°-275° C. being preferred. Pressures can also vary within a wide range of about 1 atmosphere to 130 atmospheres. Since liquid phase conditions are generally preferred within the reaction zone, the pressure should be sufficient to maintain the reactants in such phase and will typically fall in a range of from 10 to 50 atmospheres. Reactants generally pass through the alkylation zone at a mass flow rate sufficient to yield a liquid hourly space velocity from 0.5 to 50 hrs -1 and especially from about 1 to 10 hrs -1 .
The alkylation zone is ordinarily operated to obtain an essentially complete conversion of the alkylating agent to monoalkylate and polyalkylate. To achieve this effect, additional aromatic substrate will usually be charged to the reaction zone. Thus, the feed mixtures are introduced into the reaction zone at a constant rate and a molecular ratio of about 1:1 to 20:1 aromatic substrate to alkylating agent with a ration of about 2:1 to 10:1 being preferred. As a result, in addition to product there will usually be a substantial amount of unreacted aromatic substrate that is removed with the product stream from the alkylation reaction zone. Additional details of aromatic alkylation processes can be found in U.S. Pat. No. 5,177,285, the contents of which are hereby incorporated by reference.
Catalytic dehydrogenation is another example of an endothermic process that advantageously uses the process and apparatus of this invention. Briefly, in catalytic dehydrogenation, a feedstock is admixed with a recycle stream comprising hydrogen and contacted with catalyst in a reaction zone. Feedstocks for catalytic dehydrogenation are typically petroleum fractions comprising paraffins having from about 3 to about 18 carbon atoms. Particular feedstocks will usually contain light or heavy paraffins. For example a usual feedstock for producing a heavy dehydrogenation products will comprise paraffins having 10 or more carbon atoms. The catalytic dehydrogenation process is particularly applicable to the treatment of hydrocarbon feedstocks containing substantially paraffinic hydrocarbons which are subject to dehydrogenation reactions to thereby form olefinic hydrocarbon compounds.
A catalytic dehydrogenation reaction is normally effected in the presence of catalyst particles comprised of one or more Group VIII noble metals (e.g., platinum, iridium, rhodium, palladium) combined with a porous carrier, such as a refractory inorganic oxide. Alumina is a commonly used carrier. The preferred alumina materials are known as the gamma, eta and theta alumina with gamma and eta alumina giving the best results. Preferably, the carrier will have a surface area of from 100 to about 500 m 2 /g. The particles are usually spheroidal and have a diameter of from about 1/16th to about 1/ -- th inch (1.5-3.1 mm), though they may be as large as 1/4th inch (6.35 mm). Generally, the catalyst particles have a chloride concentration of between 0.5 and 3 weight percent. During the course of a alehydrogenation reaction, catalyst particles also become deactivated as a result of coke deposition and require regeneration, similar to that described in conjunction with the reforming process; therefore, in preferred form, the dehydrogenation process will again employ a moving bed reaction zone and regeneration zone.
Dehydrogenation conditions include a temperature of from about 400° to about 900° C., a pressure of from about 0.01 to 10 atmospheres and a liquid hourly space velocity (LHSV) of from about 0.1 to 100 hr -1 . Generally, for normal paraffins, the lower the molecular weight the higher the temperature required for comparable conversions. The pressure in the dehydrogenation zone is maintained as low as practicable, consistent with equipment limitations, to maximize the chemical equilibrium advantages. The preferred alehydrogenation conditions of the process of this invention include a temperature of from about 400°-700° C., a pressure from about 0.1 to 5 atmospheres, and a liquid hourly space velocity of from about 0.1 to 100 hr -1 .
The effluent stream from the dehydrogenation zone generally will contain unconverted dehydrogenatable hydrocarbons, hydrogen and the products of dehydrogenation reactions. This effluent stream is typically cooled and passed to a hydrogen separation zone to separate a hydrogen-rich vapor phase from a hydrocarbon-rich liquid phase. Generally, the hydrocarbon-rich liquid phase is further separated by means of either a suitable selective adsorbent, a selective solvent, a selective reaction or reactions or by means of a suitable fractionation scheme. Unconverted dehydrogenatable hydrocarbons are recovered and may be recycled to the alehydrogenation zone. Products of the alehydrogenation reactions are recovered as final products or as intermediate products in the preparation of other compounds.
The dehydrogenatable hydrocarbons may be admixed with a diluent gas before, while, or after being passed to the dehydrogenation zone. The diluent material may be hydrogen, steam, methane, carbon dioxide, nitrogen, argon and the like or a mixture thereof. Hydrogen is the preferred diluent. Ordinarily, when a diluent gas is utilized as the diluent, it is utilized in amounts sufficient to ensure a diluent gas to hydrocarbon mole ratio of about 0.1 to about 20, with best results being obtained when the mole ratio range is about 0.5 to 10. The diluent hydrogen stream passed to the alehydrogenation zone will typically be recycled hydrogen separated from the effluent from the dehydrogenation zone in the hydrogen separation zone.
Water or a material which decomposes at dehydrogenation conditions to form water such as an alcohol, aldehyde, ether or ketone, for example, may be added to the dehydrogenation zone, either continuously or intermittently, in an amount to provide, calculated on the basis of equivalent water, about 1 to about 20,000 weight ppm of the hydrocarbon feed stream. About 1 to about 10,000 weight ppm of water addition gives best results when dehydrogenating paraffins having from 6 to 30 more carbon atoms. Additional information related to the operation of alehydrogenation catalysts, operating conditions, and process arrangements can be found in U.S. Pat. Nos. 4,677,237; 4,880,764 and 5,087,792, the contents of which are hereby incorporated by reference.
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A reactor arrangement and process for indirectly contacting a reactant stream with a heat exchange stream uses an arrangement of corrugated heat exchange plates and a plate containing protrusions between the corrugated plates to control temperature conditions by varying the number and/or the projection of the protrusions between the plates. The reactor arrangement and process of this invention may be used to operate a reactor under isothermal or other controlled temperature conditions. The variation in protrusion arrangements within a single heat exchange section is highly useful in maintaining a desired temperature profile in an arrangement having a cross-flow of heat exchange medium relative to reactants. The protrusion arrangement offers a simplified method to eliminate or minimize the typical step-wise approach to isothermal conditions.
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BACKGROUND OF THE INVENTION
Various devices have been utilized over time for the separation of nitrogen and oxygen from air. Many such devices rely on a membrane that is exposed to pressurized air, such that oxygen molecules preferentially (compared to the larger nitrogen molecules) diffuse through the membrane, resulting in an oxygen-enriched gas on one side of the membrane and a nitrogen-rich gas on the other side of the membrane. These gases are also referred to as oxygen-enriched air (OEA) and nitrogen-enriched air (NEA), respectively. The effectiveness of membranes at performing the task of separating gases can be characterized by a trade-off that membranes experience between permeability of the membrane to the gas molecules targeted for diffusion across the membrane versus selectivity of the membrane between the targeted gas molecules and other molecules in the gas mixture. A plot of the collection of permeability versus selectivity values for various materials is known as a Robeson plot, and the upper performance limit of membrane materials is identified by a line along that plot known as the Robeson limit. Various types of materials have been used as membranes for gas separation. Inorganic metal oxides of various compositions and crystal structures have been proposed, but the materials are brittle and susceptible to damage and are also difficult to fabricate in membrane configurations. Various types of polymer and/or polymer composite materials have also been proposed. These materials can overcome some of the mechanical limitations of inorganic materials, but they typically rely on a membrane structure where selectivity is provided by a combination of the gas molecule solubility in the polymer matrix and its diffusivity through the polymer matrix, i.e. the torturous path that the gas molecules must traverse through in order to cross the membrane, and may not provide a Robeson limit that is as high as desired. Attempts to increase the selectivity of composites by incorporating high-selectivity materials into a polymer matrix have met with limited success because polymer matrices configured to prevent gas molecules from bypassing the dispersed selective material component also tend to limit the overall permeability of the membrane. Moreover, in most of the cases, these highly selective materials are incompatible with the polymer matrix, which leads to voids in the composite and reduction in selectivity.
There are, of course, many uses for OEA or NEA, so there are a variety of applications for devices that separate oxygen and nitrogen, including but not limited to medical oxygen concentrators, atmospheric oxygen supplementation systems, and NEA-based combustion suppression systems. In recent years, commercial and other aircraft have been equipped with fuel tank suppression systems that introduce NEA into a fuel tank headspace or ullage, often by bubbling NEA through the liquid fuel. Such systems require NEA with a nitrogen concentration of at least 90% by volume, and attempt to minimize payload weight and size while maintaining target NEA output across a wide variety of operating conditions. Nitrogen-generating using membrane technology has been used and proposed for use in these and other systems; however many of these systems suffer from various shortcomings such as performance specification limitations imposed by the membrane's Robeson limit, lack of stability in performance specifications over time, inability to maintain performance levels across a wide variety of conditions, inability to meet payload weight or size requirements, etc. Accordingly, there continues to be a need for new approaches to the separation of nitrogen and oxygen.
BRIEF DESCRIPTION OF THE INVENTION
According to some aspects of the invention, a method of separating oxygen from nitrogen, comprises delivering air to a first side of a membrane comprising a polymer support and a layer comprising a plurality of zeolite nanosheet particles (zeolite nanosheet particles may also be referred to herein as zeolite nanosheets) with thickness of 2 nm to 10 nm and mean diameter of 50 nm to 5000 nm. It should be noted that, as used herein, “air” includes natural air from the Earth's atmosphere and also includes any gas mixture comprising nitrogen and oxygen for which the methods and materials described herein are used to separate oxygen in the gas mixture from nitrogen in the gas mixture). The delivered air provides a pressure differential between opposite sides of the membrane, thus causing oxygen in the hollow core to diffuse through the polymer support and the layer comprising zeolite nanosheet particles to the second side of the membrane. This preferential diffusion of oxygen (compared to the diffusion of nitrogen) through the membrane produces nitrogen-enriched air on the first side of the membrane and oxygen-enriched air on the second side of the membrane.
According to some aspects of the invention, a device for separating nitrogen and oxygen comprises a hollow polymer fiber comprising a polymer shell surrounding a hollow core. The hollow core extends from one end of the fiber to the other end of the fiber and is open at one end of the fiber to receive a flow of air and open at the opposite end of the fiber to discharge a flow of nitrogen-enriched air. The fiber has a layer disposed on its exterior surface, comprised of a plurality of zeolite nanosheet particles with thickness of 2 nm to 10 nm and mean diameter of 50 nm to 5000 nm.
According to some aspects of the invention, the above hollow fiber device can be prepared by disposing a hollow polymer fiber comprising a polymer shell surrounding a hollow core that extends from one end of the fiber to the other end of the fiber, in a coating composition comprising zeolite nanosheet particles with thickness of 2 nm to 10 nm and mean diameter of 50 nm to 5000 nm, such that the hollow core is isolated from the coating composition at each fiber end is connected to a source of vacuum on at least one end of the fiber. A vacuum is drawn the hollow core of the fiber to cause a pressure differential between the exterior and the hollow core of the hollow polymer fiber, which in turn causes deposition of a layer comprising zeolite nanosheet particles onto the hollow polymer fiber exterior. The zeolite nanosheet particle layer can then be heated to fuse the nanosheets together.
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 figures, in which:
FIG. 1 is a schematic depiction of an exemplary planar membrane for separating nitrogen and oxygen;
FIG. 2 is a schematic depiction of an exemplary tubular membrane for separating nitrogen and oxygen; and
FIG. 3 is a schematic depiction of an exemplary device for separating oxygen and nitrogen.
DETAILED DESCRIPTION OF THE INVENTION
With reference to the Figures, FIGS. 1 and 2 schematically depict exemplary membranes for separating nitrogen and oxygen. FIG. 1 depicts a flat or planar membrane 10 comprising a polymer support 12 and zeolite nanosheet layer 14 . In use, air is delivered to the surface of polymer support 12 to provide a pressure differential across the membrane. In response, oxygen molecules preferentially diffuse through the membrane 10 compared to nitrogen molecules, resulting in a flow of OEA from the upper surface of the membrane 10 (e.g., through layer 14 ) as shown in FIG. 1 , and a flow of NEA from the lower surface of membrane 10 as shown in FIG. 1 .
FIG. 2 depicts a tubular membrane 20 comprising a polymer tubular shell 22 surrounded by a zeolite nanosheet layer 24 . The shell defines a hollow core 26 that is open at both ends. In use, pressurized air is delivered into the hollow core 26 at an inlet end 27 of the membrane 20 . The pressure of the air is greater than air outside the core 26 such that a pressure differential between the hollow core 26 and the air exterior of the membrane 20 exists. Oxygen molecules preferentially diffuse through the tubular membrane 20 compared to nitrogen molecules, resulting in a flow of OEA from the outer surface of the tubular membrane 20 as shown in FIG. 2 , and a flow of NEA from the hollow core 26 at the outlet end 28 of the membrane 20 as shown in FIG. 2 .
Turning now to FIG. 3 , a device 30 comprising multiple tubular membranes 20 for separating oxygen and nitrogen is schematically depicted. As shown in FIG. 3 , a device 30 for separating oxygen and nitrogen has an intake plenum 32 with inlet 34 for receiving air from an air source (not shown) such as a compressor or vehicle air intake. Air in the intake plenum flows into the hollow cores 26 ( FIG. 2 ) of tubular membranes 20 towards discharge plenum 36 , where it is collected and discharged through NEA outlet 38 . Oxygen flowing through the hollow cores 26 of the tubular membranes 20 preferentially (versus nitrogen) diffuses through the tubular membranes 20 , so that the gas discharged into discharge plenum 36 is nitrogen enhanced. A housing 40 is disposed around the tubular membranes 20 and forms a sealed connection with the intake plenum 32 and the discharge plenum 36 . The tubular membranes 20 also form sealed connections at each end with the intake plenum 32 and discharge plenum 36 , respectively, so that housing 40 together with the inner surfaces of the plenums 32 , 36 forms a chamber for collecting oxygen-enhanced air, which is discharged through OEA outlet 42 . It will be appreciated that, based on the guidance provided herein, one skilled in the art would set component sizes (e.g., core and outside fiber diameters), number of fibers, etc., and also to set operating parameters such as control valve settings at the inlet and the outlets to provide pressure differentials and gas flow amounts to achieve a target gas diffusion profile through the membranes.
In some aspects of the invention, the methods and devices described herein produce a NEA stream of at least 90 vol. % nitrogen, more specifically at least 95% nitrogen, and even more specifically at least 98% nitrogen. In some aspects of the invention, the methods and devices described herein produce an OEA stream of at least 25 vol. % oxygen, more specifically at least 30% oxygen, and even more specifically at least 35% oxygen.
The polymer supports described herein can be formed from a number of different materials, including but not limited to polyethylene, polypropylene, polytetrafluoroethylene, polycarbonate, polyethersulfone, TPU (thermoplastic polyurethane), polyimide. Thickness of the polymer support can range from 50 nm to 1000 nm, more specifically from 100 nm to 750 nm, and even more specifically from 250 nm to 500 nm. The selectivity provided by the zeolite nanosheet layer can allow for a smaller thickness compared to conventional tortorous path polymer and polymer composite membranes resulting into more permeable polymer support. In the case of tubular membranes 20 as described in FIGS. 2 and 3 , fiber diameters can range from 100 nm to 2000 nm, and fiber lengths can range from 0.2 m to 2 m.
Thickness of the zeolite nanosheet layer can range from 2 nm to 500 nm, more specifically from 2 nm to 100 nm, and even more specifically from 2 nm to 50 nm. The zeolite nanosheet particles themselves can have thicknesses ranging from 2 to 50 nm, more specifically 2 to 20 nm, and even more specifically from 2 nm to 10 nm. The mean diameter of the nanosheets can range from 50 nm to 5000 nm, more specifically from 100 nm to 2500 nm, and even more specifically from 100 nm to 1000 nm. Mean diameter of an irregularly-shaped tabular particle can be determined by calculating the diameter of a circular-shaped tabular particle having the same surface area in the x-y direction (i.e., along the tabular planar surface) as the irregularly-shaped particle. The zeolite nanosheets can be formed from any of various zeolite structures, including but not limited to framework type MFI, MWW, FER, LTA, FAU, and mixtures of the preceding with each other or with other zeolite structures. In a more specific group of exemplary embodiments, the zeolite nanosheets comprise zeolite structures selected from MFI, MWW, FER, LTA framework type. Zeolite nanosheets can be prepared using known techniques such as exfoliation of zeolite crystal structure precursors. For example, MFI and MWW zeolite nanosheets can be prepared by sonicating the layered precursors (multilamellar silicalite-1 and ITQ-1, respectively) in solvent. Prior to sonication, the zeolite layers can optionally be swollen, for example with a combination of base and surfactant, and/or melt-blending with polystyrene. The zeolite layered precursors are typically prepared using conventional techniques such as sol-gel method.
The zeolite nanosheet layer can be formed by coating a dispersion of the nanosheets in solvent onto the polymer support using known techniques, such as spray coating, dip coating, solution casting, etc. The dispersion can contain various additives known for nanodispersions, such as dispersing aids, rheology modifiers, etc. Polymeric additives can be used; however, a polymer binder is not needed, although a polymer binder can be included and in some embodiments is included. However, a polymer binder present in an amount sufficient to form a contiguous polymer phase having the zeolite nanosheets dispersed therein can provide passageways in the membrane for nitrogen to bypass the zeolite nanosheets. Accordingly, in some embodiments a polymer binder is excluded. In other embodiments, a polymer binder is present in an amount below that needed to form a contiguous polymer phase.
In some exemplary embodiments, the layer is applied with a vacuum enhanced dip coating process where a surface of the support is disposed in a nanosheet dispersion while a vacuum is applied from the opposite side of the support. This draws solvent from the dispersion through the polymer support, resulting in deposition of the nanosheets onto the support. In the case of hollow fiber membranes as shown in FIG. 2 , this vacuum filtration technique is particularly effective, as the hollow core 26 provides an enclosed space from which to draw a vacuum without the necessity of a vacuum frame or similar structure that would be needed for a flat or planar membrane configuration.
After coating the layer of zeolite nanosheets onto the polymer support, the layer can be dried to remove residual solvent and optionally heated to fuse the nanosheets together into a contiguous layer. Such heat should be applied under conditions to limit any heat damage to the polymer support. This can be accomplished by limiting the duration of any heating to that sufficient to heat the very thin nanosheet layer without overheating the thicker underlying polymer support. Exemplary heating conditions can involve temperatures of 20° C. to 100° C., more specifically from 20° C. to 75° C., and even more specifically from 20° C. to 50° C.
While the invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Additionally, while various embodiments of the invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.
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A method of separating oxygen from nitrogen involves delivering air to a first side of a membrane comprising a polymer support and a layer of zeolite nanosheet particles with thickness of 2 nm to 10 nm and mean diameter of 5 nm to 5000 nm. The delivered air provides a pressure differential between opposite sides of the membrane, thus causing oxygen in the hollow core to diffuse through the polymer support and the zeolite nanosheet layer to the second side of the membrane. The preferential diffusion of oxygen (compared to diffusion of nitrogen) through the membrane produces nitrogen-enriched air on the first side of the membrane and oxygen-enriched air on the second side of the membrane.
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TECHNICAL FIELD
[0001] The present invention relates to a sleep improvement support device, a sleep improvement support method, a sleep improvement support program, and a sleep improvement support program storage medium, which assist, with sleep improvements, people having insomnia or sleep-related problems.
BACKGROUND ART
[0002] A cognitive-behavioral therapy is known as a methodology for correcting a tendency to think things negative, into a balanced mind set, by focusing on the facts and behaviors. In the field of insomnia therapy, too, it has been reported that a therapeutic effect with a high remission rate is obtained by introducing the cognitive-behavioral therapy. The cognitive-behavioral therapy for insomnia is called CBT-I (cognitive-behavioral therapy for insomnia), and there also exist Web services that are based on the CBT-I concept and CBT-I tools such as a self-care application.
[0003] In CBT-I, guidance related to sleep hygiene, guidance related to sleep schedules and guidance related to relaxation are performed.
[0004] In the guidance related to sleep hygiene, practices and environments that would cause awakening are learned, and if there is such a practice or an environment, lifestyle improvement measures are taken to improve them, for example. In addition, in the guidance related to sleep schedules, importance of making it a practice to sleep on the bed or on the bedding is learned, and lifestyle improvement measures to practice such a practice. Furthermore, in the guidance related to relaxation, a mindset or a behavior so as to prepare for sleep without any unneeded power is learned, and lifestyle improvement measures incorporating a relaxation method of their own are taken.
[0005] Furthermore, in addition to the above-described guidance, there are cases where mental education is provided such as, analyzing the situation of the consulter and correcting knowledges regarding the factors relevant to the consulter's sleep is conveyed to the consulter, giving an advice or disclosing data so as to correct a habit in the consulter's cognition or behavior that could continue or worsen the insomnia, if any, and the like.
[0006] In CBT-I, the consulter is given, as a daily assignment, among the lifestyle improvement measures as described above, those that are not achieved by the consulter, and through exercising such assignments, the consulter's practices which have adverse effects on the consulter's sleep are removed. The consulter may temporarily have hard time coping with such assignments on a daily basis, but if the consulter can learn a proper practice, the sustainable effect can be expected.
[0007] As a technology making use of such a concept of CBT-I, Patent Literature 1, for example, describes a system that obtains a correlation between the collected objective indices related to sleep and the subjective indices, and makes a proposal to improve sleep on the basis of the result thereof.
[0008] In addition, Patent Literature 2 describes a system that provides a warning, a guide, an advice, or a message to encourage users, and proposes update of the behavior, so as to help the user comply with any behavioral program selected for the user.
CITATION LIST
Patent Literature
[0009] [PTL 1] International Publication WO 2008/096307
[0010] [PTL 2] Japanese Patent No. 5307084
SUMMARY OF INVENTION
Technical Problem
[0011] CBT-I is known to be highly effective on condition that the consulter is dedicated to continue to achieve the daily assignments given to the consulter. However, CBT-I has such a problem that, when the consulter has a wrong cognition about the quality of his or her sleep, no effect is obtained even if he or she achieves the assignments, or the symptom worsens.
[0012] Among the symptoms alleged by a patient to a doctor, the main one is called “chief complaint”. In the field of cognitive-behavioral therapy, the consulter's concern or worries are also called “chief complaint”, not limited to symptoms. There are roughly four main complaints related to insomnia as follows:
[0000] Difficulty falling asleep,
Awaking during sleep
Early morning awaking, and
Trouble in sound sleep.
[0013] Examples of the chief complaint belonging to “difficulty falling asleep” include “not easily falling asleep”. Examples of the chief complaint belonging to “awaking during sleep” include “awaking often during sleep”. Examples of the chief complaint belonging to “early morning awaking” include “awaking early in the morning”. Examples of the chief complaint belonging to “trouble in sound sleep” include “not feeling like having slept.”
[0014] The chief complaint is based on the subjective judgment of the consulter. When the consulter takes the chief complaint excessively serious, there may occur such cases where, even if the consulter achieves the assignment, the effect is not felt, which hinders the achievement of the assignment, or such cases where the worries worsen to cause the consulter to take the mindset or the behavior that would tend to cause insomnia. In order to avoid such problems, it is effective to remind the consulter that the state alleged by the consulter as the chief complaint is not in fact affecting the daily lives so much as the consulter thinks.
[0015] Note that the method described in Patent Literature 1 is merely to make a proposal effective for the subjective indices, by finding an objective index correlated with the subjective indices, and is not intended to assist the consulter by focusing on no correlation between the chief complaint and the state of the next day.
[0016] In Patent Literature 2, through analyzing the subjective information and the objective information, it is possible to show that a sufficient amount of sleep is obtained using the objective information, for example, even when a user report the incidence of difficulty staying asleep or unrefreshing sleep, and the activity level during the day is scored low. The objective information is, for example, sensor information sensing the activities at night and a cognition score of a user. The described is that this can resolve anxiety of a user.
[0017] However, in order to implement the method described in Patent Literature 2, the sensor unit data or the objective test data are necessary, and, accordingly, there are problems that a large-scale system is required to collect them, and they are troublesome for a user since a test have to be taken.
[0018] In view of this, the present invention has an objective of providing a sleep improvement support device, a sleep improvement support method, a sleep improvement support program, and a sleep improvement support program storage medium which are capable of, when a consulter has a wrong cognition about the quality of the consulter's own sleep, easily making the consulter notice that.
Solution to Problem
[0019] A sleep improvement support device according to the present invention includes: sleep-related data storage means for storing, for two or more days, with date information, sleep-related data including sleep evaluation data for measuring a quality of sleep of a day and quality evaluation data that is influenced by the quality of sleep of the day, the sleep evaluation data being data of one or more items each of which indicates a state, a behavior, or a sense of a consulter, the quality evaluation data being data of one or more items each of which indicates a state, a behavior, or a sense of the consulter after rising; chief complaint information input means for receiving, as input, chief complaint information indicating chief complaint of the consulter; contradiction information extracting means for extracting contradiction information indicating variation, between days, in relationship between chief complaint item data and chief complaint evaluation item data, from the sleep-related data stored in the sleep-related data storage means, the chief complaint item data being an item of sleep evaluation data relating to the chief complaint of the consulter, the chief complaint evaluation item data being an item of quality evaluation data relating to the chief complaint of the consulter; and output means for outputting the contradiction information extracted by the contradiction information extracting means and/or a message based on the contradiction information.
[0020] A sleep improvement support method according to the present invention includes: in a state in which sleep-related data storage means stores, for two or more days, with date information, sleep-related data including sleep evaluation data for measuring a quality of sleep of a day and quality evaluation data that is influenced by the quality of sleep of the day, the sleep evaluation data being data of one or more items each of which indicates a state, a behavior, or a sense of a consulter, the quality evaluation data being data of one or more items each of which indicates a state, a behavior, or a sense of the consulter after rising, when chief complaint information indicating chief complaint of the consulter is received as input, extracting, by an information processing device, contradiction information indicating variation, between days, in relationship between chief complaint item data and chief complaint evaluation item data, from the sleep-related data stored in the sleep-related data storage means, the chief complaint item data being an item of sleep evaluation data relating to the chief complaint of the consulter, the chief complaint evaluation item data being an item of quality evaluation data relating to the chief complaint of the consulter; and outputting, by the information processing device, the contradiction information extracted by the contradiction information extracting means and/or a message based on the contradiction information.
[0021] A program storage medium the present invention stores a sleep improvement support program causing a computer capable of accessing sleep-related data storage means storing, for two or more days, with date information, sleep-related data including sleep evaluation data for measuring a quality of sleep of a day and quality evaluation data that is influenced by the quality of sleep of the day, the sleep evaluation data being data of one or more items each of which indicates a state, a behavior, or a sense of a consulter, the quality evaluation data being data of one or more items each of which indicates a state, a behavior, or a sense of the consulter after rising, to execute: chief complaint information input processing of receiving, as input, chief complaint information indicating chief complaint of the consulter; contradiction information extracting processing of extracting contradiction information indicating variation, between days, in relationship between chief complaint item data and chief complaint evaluation item data, from the sleep-related data stored in the sleep-related data storage means, the chief complaint item data being an item of sleep evaluation data relating to the chief complaint of the consulter, the chief complaint evaluation item data being an item of quality evaluation data relating to the chief complaint of the consulter; and output processing of outputting the contradiction information extracted by the contradiction information extracting means and/or a message based on the contradiction information.
Advantageous Effects of Invention
[0022] According to the present invention, it is possible to easily make, when a consulter has a wrong cognition about the quality of the consulter's own sleep, the consulter notice that.
BRIEF DESCRIPTION OF DRAWINGS
[0023] FIG. 1 is a block diagram illustrating an exemplary configuration of a sleep improvement support device according to a first exemplary embodiment.
[0024] FIG. 2 is an explanatory diagram illustrating an example of items described in a sleep diary.
[0025] FIG. 3 is an explanatory diagram illustrating an example of sleep-related data stored in a sleep-related data storage means 104 .
[0026] FIG. 4 is an explanatory diagram illustrating an example of chief complaint correspondence information.
[0027] FIG. 5 is a flowchart illustrating an exemplary operation of the sleep improvement support device according to the first exemplary embodiment.
[0028] FIG. 6 is an explanatory diagram illustrating an example of an extracting method of contradiction information.
[0029] FIG. 7 is an explanatory diagram illustrating an example of a cross-tabulation table.
[0030] FIG. 8 is an explanatory diagram illustrating an example of affirmation-negation definition data.
[0031] FIG. 9 is an explanatory diagram illustrating an example of a non-correlation notification message 12 .
[0032] FIG. 10 is an explanatory diagram illustrating an output example of an output means 103 .
[0033] FIG. 11 is an explanatory diagram illustrating an example of consistency definition data.
[0034] FIG. 12 is an explanatory diagram illustrating an example of sleep-related data.
[0035] FIG. 13 is an explanatory diagram illustrating an extracting method of contradiction information.
[0036] FIG. 14 is an explanatory diagram illustrating an output example of the output means 103 .
[0037] FIG. 15 is a block diagram illustrating an exemplary configuration of a sleep improvement support device according to a second exemplary embodiment.
[0038] FIG. 16 is a flowchart illustrating an exemplary operation of the sleep improvement support device according to the second exemplary embodiment.
[0039] FIG. 17 is an explanatory diagram illustrating an example of priority level assigned by a contradiction information ranking means 201 .
[0040] FIG. 18 is an explanatory diagram illustrating an example of consistency definition data according to the second exemplary embodiment.
[0041] FIG. 19 is an explanatory diagram illustrating a calculation expression of the priority level.
[0042] FIG. 20 is an explanatory diagram illustrating an output example of the output means 103 .
[0043] FIG. 21 is a block diagram illustrating another exemplary configuration of the sleep improvement support device according to the second exemplary embodiment.
DESCRIPTION OF EMBODIMENTS
First Exemplary Embodiment
[0044] FIG. 1 is a block diagram illustrating an exemplary configuration of a sleep improvement support device according to a first exemplary embodiment of the present invention. A sleep improvement support device 100 illustrated in FIG. 1 includes a chief complaint information input unit 101 , a contradiction information extracting unit 102 , an output unit 103 , and a sleep-related data storage unit 104 .
[0045] The sleep-related data storage unit 104 stores, for two or more days, together with information on date, sleep-related data including: sleep evaluation data that is data of one or more items indicating a state or a sense of a consulter for measuring a quality of sleep on a day; and quality evaluation data that is data of one or more items indicating a state or a sense of the consulter after waking up, which is influenced by the quality of sleep on the day.
[0046] The sleep-related data, for example, may be a group of data related to the items as described in a sleep diary illustrated in FIG. 2 . FIG. 2 is an explanatory diagram illustrating an example of items described in a sleep diary. Generally speaking, the items described in a sleep diary include quality evaluation data. The quality evaluation data is data for evaluating sleep evaluation data that is basic data for measuring the quality of sleep of the consulter on a day and the quality of sleep after waking up. It also includes, for example, data of the following items:
[0000] (1) Time when taking a nap; existence of an act of taking medicine, a type of the medicine, and an amount of the medicine; existence of an act of drinking alcohol and an amount of the alcohol; and time when going to bed;
(2) Time when trying to sleep, and a time period taken to fall asleep (sleep onset latency);
(3) The number of times of awaking during sleep (the number of awaking during sleep) and a time period of awaking during sleep (time of awaking during sleep);
(4) Time period from awaking till starting moving to (time period of early morning awaking);
(5) Subjective evaluation regarding feelings of sound sleep (sound sleep level); and
(6) Subjective evaluation regarding how much daytime (after-awaking) activities are carried out (daytime activity level).
[0047] In the present exemplary embodiment, the sleep-related data includes, as sleep evaluation data, data of one or more items indicating a state, behavior or a sense of a consulter regarding sleep on a day. In addition, the sleep-related data includes, as quality evaluation data, data of one or more items indicating a state, behavior or a sense of the consulter after awaking. The sleep evaluation data may be basic data regarding sleep of the consulter. The quality evaluation data may be data indicating a state, behavior or a sense which is of the consulter and is influenced by the quality of sleep, and may preferably include, in particular, data indicating a state, behavior or a sense which is of the consulter and is directly influenced when getting symptoms that tends to be alleged as a chief complaint.
[0048] FIG. 3 is an explanatory diagram illustrating an example of sleep-related data stored in the sleep-related data storage unit 104 . FIG. 3 represents an example of the sleep-related data in which an item number by which an item included in the sleep-related data is identified and an explanation of the item are associated with details of the item separately for each different date. In this example, data of “daytime activity level” that is the item having the item ID=“j−1” (hereafter referred to as “daytime activity level data”) corresponds to the quality evaluation data, and the data of the other items corresponds to the sleep evaluation data.
[0049] The chief complaint information input unit 101 receives, as input, chief complaint information indicating a chief complaint of the consulter. Hereafter, the chief complaint information input by the chief complaint information input unit 101 is referred to as chief complaint information 11 .
[0050] The contradiction information extracting unit 102 extracts contradiction information indicating daily variation in relationship between data of chief complaint items that are items of the sleep evaluation data corresponding to a chief complaint of a consulter (hereinafter referred to as “chief complaint item data”) and data of chief complaint evaluation items that are items of the quality evaluation data corresponding to the chief complaint of the consulter (hereinafter referred to as “chief complaint evaluation item data”), from among the sleep-related data stored in the sleep-related data storage unit 104 . A type of correlation (positive correlation or negative correlation) when assuming that there is a correlation may be considered as an example of the relationship between the chief complaint item data and certain chief complaint evaluation item data.
[0051] For example, for each of chief complaint types which are predetermined, chief complaint correspondence information in which a chief complaint item and a chief complaint evaluation item are associated is stored in a predetermined storage apparatus. Then, the chief complaint information input unit 101 receives the chief complaint information including a chief complaint type of a chief complaint of a consulter. In such a case, the contradiction information extracting unit 102 may extract the contradiction information indicating the daily variation of the relationship between the chief complaint item data and the chief complaint evaluation item data, based on the input chief complaint information 11 and the chief complaint correspondence information. The chief complaint types indicate predetermined types into which complaints that are possible as the chief complaints are classified in advance, and are the above-mentioned “difficulty falling asleep” “awaking during sleep” “early morning awaking” and “trouble in sound sleep” and the like. The chief complaint types are not limited to those. Although not illustrated in FIG. 1 , the sleep improvement support device 100 according to the present exemplary embodiment may include a chief complaint correspondence information storage unit storing therein such chief complaint correspondence information.
[0052] FIG. 4 is an explanatory diagram illustrating an example of chief complaint correspondence information. FIG. 4 illustrates an example of the chief complaint correspondence information in which a chief complaint type is associated with an item ID of a relevant item of the chief-complaint-related data as information indicating the chief complaint item. The chief complaint correspondence information may be information in which a chief complaint evaluation item that a relevant item in the quality evaluation data is associated, in addition to the chief complaint item. One chief complaint evaluation item may be predetermined regardless of the chief complaint type, or the user may select the chief complaint evaluation item. When a user selects the chief complaint evaluation item, the chief complaint information input unit 101 may receive the chief complaint information 11 including the selected chief complaint evaluation item.
[0053] The output unit 103 outputs the contradiction information extracted by the contradiction information extracting unit 102 . Or, the output unit 103 outputs a message based on the contradiction information extracted by the contradiction information extracting unit 102 . Hereinafter, the message based on the contradiction information output by the output unit 103 may be referred to as non-correlation notification message 12 . The output unit 103 may output the contradiction information as it is, or may output, as non-correlation notification message 12 , a message indicating that there is no correlation between the chief complaint item data and the chief complaint evaluation item data, together with information indicating how much the variation of the relationship between the chief complaint item data and the chief complaint evaluation item data is, for example.
[0054] According to the present exemplary embodiment, the sleep-related data storage unit 104 is implemented with a storage unit such as a memory or a database system. In addition, the chief complaint information input unit 101 is implemented with an information input apparatus such as a mouse and a keyboard, or a touch panel, and an information processing apparatus such as a CPU (central processing unit) operating according to a program. The contradiction information extracting unit 102 is implemented with an information processing apparatus such as a CPU operating according to a program. In addition, the output unit 103 is implemented with an information output apparatus such as a display apparatus or a printer, and an information processing apparatus such as a CPU operating according to a program. The information input apparatus and the information output apparatus include a network interface such as a network card that receives information from a connected communication network and transmits information to the connected communication network, and a control apparatus thereof.
[0055] Next, the operation according to the present exemplary embodiment is explained. FIG. 5 is a flowchart illustrating an exemplary operation according to the present exemplary embodiment. As illustrated in FIG. 5 , when sleep-related data is input to the sleep improvement support device 100 according to the present exemplary embodiment, the sleep-related data storage unit 104 successively stores the input sleep-related data together with date information (Steps S 101 , S 102 ). Although not illustrated in FIG. 1 , the sleep improvement support device 100 may include a sleep-related data input unit prompting a user to input sleep-related data. The sleep-related data input unit may, for example, provide an interface (input screen, and the like) to a user for inputting the content of sleep-related data for one day, and register, to the sleep-related data storage unit 104 , content of each item input through the interface, as the sleep-related data of the designated day.
[0056] When the sleep-related data storage unit 104 is in a state of storing therein sleep-related data of two or more days, and chief complaint information 11 is input through the chief complaint information input unit 101 (Step S 103 ), the contradiction information extracting unit 102 extracts contradiction information from the sleep-related data stored in the sleep-related data storage unit 104 (Step S 104 ).
[0057] The chief complaint information input unit 101 , for which an interface for a user to input a concern is prepared in advance, may input the chief complaint information 11 , for example, by prompting the user to select the relevant one on the interface from among alternatives of the chief complaint types included in the chief complaint, which are set as options. The chief complaint information input unit 101 may have a function of analyzing the characters freely input by a user, and automatically determining which of the chief complaint types is relevant. In such a case, data for recognition such as keywords and expression samples each relating to the chief complaint types, for example, “not easily falling asleep”, “awaking during sleep”, “awaking early in the morning”, “not feeling like having slept” and the like, may be registered in advance in the chief complaint correspondence information.
[0058] When the contradiction information extracting unit 102 extracts contradiction information, the output unit 103 presents (outputs), to a user, the extracted contradiction information and/or the non-correlation notification message 12 based on the extracted contradiction information (Yes in Step S 105 , S 106 ). When no contradiction information is extracted, the process may just end (No in Step S 105 ).
[0059] Next, an extracting method of contradiction information by the contradiction information extracting unit 102 is explained with reference to a specific example.
[0000] FIG. 6 is an explanatory diagram illustrating an example of an extracting method of contradiction information. In the following, explanation is given using, as an example, a case in which the chief complaint information 11 including the chief complaint type indicating “difficulty falling asleep” is input. In addition, in the following, it is assumed that, as illustrated in FIG. 4 , “sleep onset latency” that is the item of the item ID=“f−1” is registered in the chief complaint correspondence information, as a chief complaint item associated with “difficulty falling asleep”. It is also assumed that “daytime activity level” that is the item of the item ID=“j−1” is set, in advance, to be used as a chief complaint evaluation item associated with “difficulty falling asleep”.
[0060] As illustrated in FIG. 6 , the contradiction information extracting unit 102 first identifies a combination of dates (hereinafter referred to as “date pair”) on which the similarity level of the chief complaint evaluation item data between the dates is equal to or more than a predetermined threshold value, from the sleep-related data stored in the sleep-related data storage unit 104 (Step 1 ). In Step 1 , the date pair of “10/15” and “10/16”, the date pair of “10/15” and “10/17”, and the date pair of “10/16” and “10/17”, which are three date pairs in total, are identified by assuming that the date pair has a similarity level equal to or more than the predetermined threshold value when the difference between the daytime activity levels indicated by the daytime activity level data of the dates in the date pair is within ±1.
[0061] Next, from among the identified date pairs, the contradiction information extracting unit 102 identifies the date pair for which difference in the chief complaint item data is equal to or more than a predetermined threshold value (Step 2 ). In Step 2 , the date pair of “10/15” and “10/17” is selected, as the date pair having the largest difference of the sleep onset latency indicated by sleep onset latency data of the dates included in the date pair, from among the date pairs having the difference of the sleep onset latency is equal to or more than 30 minutes, for example. Lastly, the chief complaint item data in the date pair identified in Step 2 (the sleep onset latency data in this example) and the chief complaint evaluation item data (daytime activity level in this example) are extracted as the contradiction information (Step 3 ).
[0062] When contradiction information is extracted, the output unit 103 may output, together with the extracted contradiction information, a message indicating that the chief complaint (“difficulty falling asleep” in this example) is not a very serious problem.
[0063] Next, with reference to FIG. 7 through FIG. 9 , another extracting method of the contradiction information by the contradiction information extracting unit 102 is explained. FIG. 7 is an explanatory diagram illustrating an example of a cross-tabulation table used for extraction of the contradiction information. FIG. 8 is an explanatory diagram illustrating an example of affirmation-negation definition data used for extraction of the contradiction information. FIG. 9 is an explanatory diagram illustrating an output example of a non-correlation notification message 12 based on the extracted contradiction information.
[0064] On the basis of the affirmation-negation definition data as illustrated in FIG. 8 for example, the contradiction information extracting unit 102 performs cross-tabulation of the number of days of the chief complaint item data as each of true and false (admission/non-admission) and the number of days of the chief complaint evaluation item data as each of true and false (admission/non-admission), for the sleep-related data of dates of latest days of a predetermined number (e.g., seven days), among the sleep-related data stored in the sleep-related data storage unit 104 . When, as a result of the cross-tabulation, the number of days on which the affirmation-negation does not match between the chief complaint item data and the chief complaint evaluation item data is equal to or more than a predetermined threshold value, the contradiction information extracting unit 102 may extract the result of that cross-tabulation as the contradiction information. The result of such cross-tabulation helps examine the level of how the relationship between the chief complaint item data and the chief complaint evaluation item data varies in different days.
[0065] The affirmation-negation definition data is data defining the affirmation-negation determining method of the items included in the sleep-related data. More specifically, the affirmation-negation definition data may be information defining the affirmation-negation determining method, regarding at least the chief complaint item and the chief complaint evaluation item included in the sleep-related data. FIG. 8 represents an example of affirmation-negation definition data including admission criteria and non-admission criteria, as an example of information representing the affirmation-negation determining method. Although not illustrated in FIG. 1 , the sleep improvement support device 100 according to the present exemplary embodiment may include a affirmation-negation data storage unit storing therein such definition data.
[0066] On the basis of the affirmation-negation definition data illustrated in FIG. 8 , the contradiction information extracting unit 102 counts the number of days on which the chief complaint item data satisfies admission criterion and the chief complaint evaluation item data satisfies admission criterion, in the sleep-related data of the latest seven days, and records the number of days in the field “c_aa” of the cross-tabulation table illustrated in FIG. 7 . Similarly, the contradiction information extracting unit 102 counts the number of days on which the chief complaint item data satisfies the admission criterion and the chief complaint evaluation item data satisfies non-admission criterion, in the sleep-related data of the latest seven days, and records the number of days in the field “c_ao” of the cross-tabulation table illustrated in FIG. 7 . Similarly, the contradiction information extracting unit 102 counts the number of days on which the chief complaint item data satisfies non-admission criterion and the chief complaint evaluation item data satisfies the admission criterion, in the sleep-related data of the last seven days, and records the number of days in the field “c_oa” of the cross-tabulation table illustrated in FIG. 7 . Similarly, the contradiction information extracting unit 102 counts the number of days on which the chief complaint item data satisfies the non-admission criterion and the chief complaint evaluation item data satisfies the non-admission criterion, in the sleep-related data of the last seven days, and records the number of days in the field “c_oo” of the cross-tabulation table illustrated in FIG. 7 . When, as a result of the measurement, the number of days in the field “c_oa” is equal to or more than a predetermined threshold or the number of days in the field “c_ao” is equal to or more than the predetermined threshold value, the contradiction information extracting unit 102 may extract, as contradiction information, the cross-tabulation table recording measurement results.
[0067] When the contradiction information is extracted, the output unit 103 may output a non-correlation notification message 12 as illustrated in FIG. 9 , together with the extracted contradiction information, on the basis of the extracted contradiction information. For example, assume a case in which the number of days in the column “c_oa” is equal to or more than the predetermined threshold value, and there is a sleep state, which is of “Even if there was difficulty in falling asleep, you are able to be active without problems on the following day” or the like, relevant to the chief complaint. In such cases, the output unit 103 may output a non-correlation notification message 12 notifying that there are days on which the chief complaint evaluation item data that is naturally influenced indicates a good value. In this case, as illustrated in FIG. 10 , it is preferable to display, in emphasis, the field “c_oa” in the cross-tabulation table. Accordingly, variation in relationship (how it varies) between the chief complaint item data and the chief complaint evaluation item data and the level of difference (how much it varies) can also be informed. The output unit 103 may only output the contradiction information (cross-tabulation table) in which a relevant part is displayed in emphasis, without outputting any message. If the user is a doctor and the like, when the relevant part is represented, the user can give an appropriate advice to the patient on the basis of it. FIG. 10 is an explanatory diagram illustrating an output example of an output unit 103 in this example.
[0068] Assume a case of a day on which the number of days in the field “c_ao” is equal to or more than the predetermined threshold value, and the chief complaint evaluation item data is bad, which is of “Even if you were not able to be active without trouble on the following day, there was no difficulty in falling asleep” or the like. Even if in such a case, the output unit 103 may output a non-correlation notification message 12 notifying that there is a day on which a sleep state relating to the chief complaint is good. In this case, it is preferable to display, in emphasis, the field “c_ao” in the cross-tabulation table. Also assume a case in which the number of days in the field “c_oa” is equal to or more than the predetermined threshold value and the number of days in the field “c_aa” is equal to or more than the predetermined threshold value, and there is a sleep state, which are of “Regardless of whether there was difficulty in falling asleep or not, you feel like being able to be active on the following day” or the like, relevant to the chief complaint. In such a case, the output unit 103 may output a non-correlation notification message 12 notifying that there is a day on which the chief complaint evaluation item data that is naturally influenced indicates a good value, and there is also another day on which the chief complaint evaluation item data indicates a bad value. In this case, it is preferable to display, in emphasis, the field “c_oa” and the field “c_aa” in the cross-tabulation table. Also assume a case in which the number of days in the field “c_ao” is equal to or more than the predetermined threshold value, the number of days in the field “c_oo” is equal to or more than the predetermined threshold value. In such cases, the output unit 103 may output a non-correlation notification message 12 , “Regardless of whether there was difficulty in falling asleep or not, you feel like not being able to be active on the following day”, notifying that there is a day on which a sleep state relating to the chief complaint is bad and there is a day on which a sleep state relating to the chief complaint is good, among the days on which the chief complaint evaluation item data is bad. In this case, it is prefereable to display, in emphasis, the field “c_ao” and the field “c_oo” in the cross-tabulation table.
[0069] With reference to FIG. 11 through FIG. 13 , another extracting method of the contradiction information by the contradiction information extracting unit 102 is explained. FIG. 11 is an explanatory diagram illustrating an example of consistency definition data used for extraction of contradiction information. FIG. 12 is an explanatory diagram illustrating an example of sleep-related data from which the contradiction information is extracted. FIG. 13 is an explanatory diagram illustrating an extracting method of contradiction information.
[0070] The contradiction information extracting unit 102 may extract contradiction information indicating that the relationship between the chief complaint item data relating to the chief complaint of the consulter and predetermined chief complaint evaluation item data varies in different days, on the basis of the consistency definition data as illustrated in FIG. 11 . For example, the contradiction information extracting unit 102 may extract, as contradiction information, information on whether or not there is variation in different days or a level of the variation, in the relationship between the chief complaint item data relating to the chief complaint of the consulter and the predetermined chief complaint evaluation item data. The contradiction information extracting unit 102 may identify a part in which the relationship between the chief complaint item data and the predetermined chief complaint evaluation item data varies in different days, and extract, as the contradiction information, the sleep-related data including the part for a plurality of days, based on the consistency definition data, for example.
[0071] The consistency definition data is data in which the consistency of data of items included in the sleep-related data (i.e. what is the basis for considering the items to be consistent) is defined. In this example, consistency definition data defining the consistency is prepared in advance, at least for the chief complaint item and the chief complaint evaluation item included in the sleep-related data. FIG. 11 represents, for example, as consistency definition data for “sleep onset latency” that is the item of the item ID=“f−1”, a consistency determination criterion that is “±15 minutes” is registered. FIG. 11 also represents, for example, as consistency definition data for “daytime activity level” that is the item of the item ID=“j−1”, a consistency determination criterion that is “±1” is registered. Although not illustrated in FIG. 1 , the sleep improvement support device 100 according to the present exemplary embodiment may include a consistency definition data storage unit storing such consistency definition data.
[0072] The contradiction information extracting unit 102 may determine whether the chief complaint item data is consistent and whether the chief complaint evaluation item data is consistent between dates of the date pairs of the sleep-related data stored in the sleep-related data storage unit 104 on the basis of the consistency definition data illustrated in FIG. 11 , for example, and extract contradiction information based on that result. For example, assume a case in which the sleep-related data as illustrated in FIG. 12 is stored in the sleep-related data storage unit 104 .
[0073] First, the contradiction information extracting unit 102 identifies 10 date pairs as illustrated in (a) of FIG. 13 , as the date pairs of the sleep-related data stored in the sleep-related data storage unit 104 .
[0074] Next, the contradiction information extracting unit 102 , for each of the identified date pair, determines whether the chief complaint item data (the sleep onset latency data in this example) is consistent and whether the chief complaint evaluation item data (the daytime activity level data in this example) is consistent between the relevant dates. For example, for the date pair of “12/1” and “12/2”, the contradiction information extracting unit 102 determines that the sleep onset latency data is not consistent (“inconsistency”) between the relevant dates, based on the consistency definition data for the sleep onset latency, on the grounds that the sleep onset latency indicated by the sleep onset latency data associated with the date information “12/1” is 90 minutes, the sleep onset latency indicated by the sleep onset latency data associated with the date information “12/2” is 20 minutes, and therefore the difference therebetween is −70 minutes. In addition, the contradiction information extracting unit 102 determines that daytime activity level data is consistent (“consistency”) between the relevant dates, based on the consistency definition data for the daytime activity level, on the grounds that the daytime activity level indicated by the daytime activity level data associated with the date information “12/1” is seven, the daytime activity level indicated by the daytime activity level data associated with the date information “12/2” is seven, and therefore the difference therebetween is zero. The contradiction information extracting unit 102 performs similar processing to the remaining date pairs, thereby obtaining the determination result illustrated in (a) in FIG. 13 .
[0075] Next, the contradiction information extracting unit 102 , based on the obtained determination result, identifies the date pair in which the consistency of the chief complaint item data and the consistency of the chief complaint evaluation item data are different (refer to (b) of FIG. 13 ). Specifically, the contradiction information extracting unit 102 may extract, from the determination result illustrated in (a) of FIG. 13 , the date pair of which the chief complaint item data is not consistent and the chief complaint evaluation item data is consistent, or the date pair of which the chief complaint item data is consistent and the chief complaint evaluation item data is not consistent. In this example, as illustrated in (b) of FIG. 13 , the “12/1” and “12/2” date pair, “12/1” and “12/3” date pair, “12/1” and “12/5” date pair, “12/2” and “12/4” date pair, “12/3” and “12/4” date pair, as well as “12/4” and “12/5” date pair (total of six date pairs) are identified.
[0076] Lastly, the contradiction information extracting unit 102 extracts, as contradiction information, chief complaint item data (the sleep onset latency data in this example) and the chief complaint evaluation item data (the daytime activity level data in this example) in the identified date pairs.
[0077] When contradiction information is extracted, while displaying, in emphasis, the extracted contradiction information in the listing table of sleep-related data used for extraction as illustrated in FIG. 14 , the output unit 103 may output a non-correlation notification message 12 , such as “Even when falling asleep easily, sometimes you feel good and the other times you feel bad the following day”, notifying that even days on which the sleep states concerning the chief complaint exhibits a similar value may include days of which the chief complaint evaluation item data is good and days of which the chief complaint evaluation item data is bad. FIG. 14 illustrates an example of display in which favorability of each piece of data is exhibited, e.g., a piece of data included in the contradiction information which exhibits a favorable state is indicated by a circle mark, and a piece of data which does not is indicated by a triangle mark. Accordingly, how is the variation in the relationship between the chief complaint item data and the chief complaint evaluation item data (how they vary) and how much is the variation (how much they vary) can also be reported. In this example, too, the output unit 103 may only output the contradiction information in which the relevant parts are displayed in emphasis, without outputting any message. If the user is a doctor and the like, as long as the relevant parts are indicated, he or she can give an appropriate advice to the patient based thereupon. FIG. 14 illustrates an example in which the non-correlation notification message 12 is output by making use of the information on the latest date pair out of the extracted contradiction information. However, the number of date pair used for outputting the non-correlation notification message 12 is not limited to one. For example, all the extracted date pairs may be used, and selection may be performed one by one from the every combinations of the consistency of the chief complaint item data and the consistency of the chief complaint evaluation item data {consistent, inconsistent} {inconsistent, consistent}.
[0078] When the chief complaint item data is consistent, for example, the output unit 103 may output, as the non-correlation notification message 12 , a message suggesting a possibility that the chief complaint may not be an important cause for the daytime activity, because the daytime state of the following day is not constant even when the sleep state corresponding to the chief complaint is at the similar level. When the chief complaint evaluation item data is consistent, for example, the output unit 103 may output, as the non-correlation notification message 12 , a message suggesting a possibility that the chief complaint may not be an important cause for the daytime activity, because the daytime state of the following day is the similar level in either of cases in which the chief complaint arises and does not arise.
[0079] In the consistency definition, not only the difference in values but also information indicating that one of the pair is “admission” but the other of the pair is “non-admission” may also be considered. For example, in a case where it is deemed to be inconsistent if there is simply 30 minutes or more difference in the sleep onset latency, each day in a date pair will be determined not to have consistency if the data for the respective days is “15 minutes” and “60 minutes”. However, even in a case in which the data for the relevant days is “60 minutes” and “90 minutes”, the date pair is determined not to have consistency. Nevertheless, in the latter case, each day in the date pair is equivalent in a sense that both of the days undergo “difficulty falling asleep”. In light of this, the definition may incorporate such propriety definition data as determining the date pair to be inconsistent, if one of the days is “admission” and the other of the days is “non-admission” and the difference therebetween is 30 minutes or more. It is also possible to use such a complex rule as stipulating that, with reference to a single piece of the consistency definition data, “if the data for the one of the days is within 30 minutes, the other is equal to or more than 30 minutes, and the difference therebetween is 30 minutes or more, the date pair is deemed to be inconsistent”.
[0080] As stated in the above, according to the present exemplary embodiment, by comparing the sleep-related data of the plurality of days, and examining the consistency level of the relationship between the chief complaint item data and the chief complaint evaluation item data between the days (whether they are different between days), the non-correlation between the chief complaint and the quality of sleep is detected. Therefore, objective data is not necessarily needed. No sensor units, tests, and the like do not have to be used to obtain such objective data, and yet can easily make the consulter aware of his or her wrong cognition about the quality of his or her own sleep if the consulter has such wrong cognition.
[0081] In addition, when the relationship between the chief complaint item data and the chief complaint evaluation item data is not consistent between the days, by indicating, together with specific data, that even if there is a chief complaint related to insomnia, the chief complaint evaluation item data that would be susceptible in case of the sleep state corresponding to the chief complaint shows a favorable value, or that even days on which the chief complaint evaluation item data exhibits similar values may include a day on which sleep state concerning the chief complaint is good and a day on which the sleep state is bad. According to this, the effect of making a consulter aware of his or her way of thinking that is detrimental to insomnia can be further expected. The consulter, as his or her mental tendency, tends to overreact to the chief complaint and increase worries, which can be prevented by the present exemplary embodiment.
[0082] In the above-stated exemplary embodiment, “daytime activity level” is used as a chief complaint evaluation item; however the chief complaint evaluation item is not limited to “daytime activity level”, and may be any other items as long as a consulter considers them worsening due to the insomnia. Example of the other chief complaint evaluation items include “fresh feelings in the morning”, “how good is the makeup”, “the conditions of the shadows under the eyes”, “swelling” and “irritation level”.
Second Exemplary Embodiment
[0083] FIG. 15 is a block diagram illustrating an exemplary configuration of a sleep improvement support device according to the second exemplary embodiment of the present invention. The sleep improvement support device 200 illustrated in FIG. 15 is different from the sleep improvement support device 100 according to the first exemplary embodiment illustrated in FIG. 1 , in that the sleep improvement support device 200 includes a contradiction information ranking unit 201 .
[0084] The contradiction information ranking unit 201 assigns priority level to the extracted contradiction information, based on the magnitude of contradiction of that contradiction information, and ranks the pieces of contradiction information.
[0085] The contradiction information ranking unit 201 may assign the priority level based on the magnitude of contradiction of the extracted contradiction information, to that contradiction information, by deeming that there is a large magnitude of contradiction if there are more matching items other than the chief complaint item and the chief complaint evaluation item between the pieces of sleep-related data on dates in a combination of dates of the contradiction information, for example.
[0086] Next, the operation of the present exemplary embodiment is explained. FIG. 16 is a flowchart illustrating an exemplary operation of the present exemplary embodiment. Note that the same steps as in the first exemplary embodiment are assigned the same step numbers, and the explanation thereof is not made.
[0087] In the present exemplary embodiment, when the contradiction information extracting unit 102 extracts contradiction information (Yes in Step S 105 ), the contradiction information ranking unit 201 assigns the priority level based on the magnitude of the contradiction of that contradiction information, and ranks the contradiction information (Step S 201 ).
[0088] Next, the output unit 103 presents (outputs), to a user, contradiction information having a rank equal to or higher than the predetermined rank or having a priority level equal to or higher than a predetermined level based on the priority level assigned by the contradiction information ranking unit 201 , and/or a non-correlation notification message 12 based on that contradiction information (Step S 106 ).
[0089] FIG. 17 is an explanatory diagram illustrating an example of priority level assigned by a contradiction information ranking means 201 . Here, assume that, from among the sleep-related data illustrated in FIG. 12 , the chief complaint item data and the chief complaint evaluation item data in the total of six date pairs as illustrated in FIG. 17 are extracted as contradiction information.
[0090] The contradiction information ranking unit 201 may compare, for each piece of extracted contradiction information, corresponding items, excluding the chief complaint items and the chief complaint evaluation items in dates of each date pair of the corresponding contradiction information, and assign a higher priority level to the date pair of contradiction information having more matching items, on the ground that the contradiction of the contradiction information is greater for date pairs having more matching items.
[0091] For example, based on the consistency definition data as illustrated in FIG. 18 , the contradiction information ranking unit 201 may count, for each date pair of contradiction information, the number of items, excluding the chief complaint items and the chief complaint evaluation items, whose data matches (the number of matching items), and assign a higher priority level for the date pair having more matching items.
[0092] FIG. 18 is an explanatory diagram illustrating an example of consistency definition data according to the present example. FIG. 18 illustrates an example of consistency definition data defining, for each item included in the sleep-related data, the consistency of the data of the corresponding item. FIG. 18 illustrates an example of retaining consistency definition data separately for each chief complaint type. However, the consistency definition data may be common to all the chief complaint types. The “(UNMENTIONED)” in FIG. 18 indicates that consistency of the corresponding item is not considered.
[0093] The contradiction information ranking unit 201 , for example, may count, for each date pair of contradiction information, the number of items, excluding the chief complaint items and the chief complaint evaluation items, whose data matches (the number of matching items), based on the consistency definition data as illustrated in FIG. 18 , and, in addition, may derive the summation of the daytime activity levels, and assign a higher priority level for the date pair having a higher summation of daytime activity levels and more matching items.
[0094] The contradiction information ranking unit 201 may derive, for example, the priority level of each piece of contradiction information by using the calculation expression illustrated in FIG. 19 . FIG. 17 illustrates the calculation result of the priority levels when α=0.5 using the calculation expression illustrated in FIG. 19 .
[0095] After each piece of contradiction information is assigned a priority level in such a manner, the contradiction information ranking unit 201 , for example, may perform selection processing of, such as, selecting only the contradiction information being within a certain rank from the highest priority level or having a priority level equal to or higher than a predetermined threshold value, (which includes selecting only the date pairs having a predetermined number or more of matching items). The contradiction information ranking unit 201 may, for example, have a devised configuration so as to select one having a higher priority level from among every combinations of the consistency of the chief complaint item data and the consistency of the chief complaint evaluation item data that are {consistent, inconsistent} or {inconsistent, consistent}, respectively. By doing so, the date pairs more similar in items other than the chief complaint items and the chief complaint evaluation items can be selected. It is also possible that the output unit 103 performs the above-described selection processing based on each of the priority levels assigned to pieces of contradiction information.
[0096] The output unit 103 displays, in emphasis, as illustrated in FIG. 20 , for example, the contradiction information having the highest priority level, out of the contradiction information extracted in the listing table of sleep-related data used for extraction. The output unit 103 may output a non-correlation notification message 12 , such as “From this result, whether to fall asleep easily or not does not seem to have a substantial influence on the following day.”, reporting that even days on which values of the chief complaint evaluation item data are similar may include a day on which the sleep state concerning the chief complaint is good and a day the sleep state is bad. FIG. 20 also illustrates a piece of data included in the contradiction information which exhibit a favorable state is indicated by a circle mark, and those which do not is indicated by triangle mark, so that whether each piece of data is good or bad can be seen.
[0097] As described above, according to the present exemplary embodiment, by identifying data having a greater magnitude of contradiction, a non-correlation notification message 12 can be output to a user, to make the user more easily aware of the fact that the daytime activity is not related to the chief complaint, or that the chief complaint is not a major cause of the daytime activity.
[0098] FIG. 21 is a block diagram illustrating another exemplary configuration of the sleep improvement support device according to the present exemplary embodiment. As illustrated in FIG. 21 , the sleep improvement support device 200 according to the present exemplary embodiment may further include a chief complaint correspondence information storage unit 202 storing therein chief complaint correspondence information associating at least the chief complaint item being the relevant item in the sleep evaluation data included in the sleep-related data, with each of the chief complaint types determined in advance, similarly to the case of the first exemplary embodiment.
[0099] In addition, the sleep improvement support device 200 according to the present exemplary embodiment may further include a sleep-related data input unit 203 to let a user input sleep-related data, similarly to the case of the first exemplary embodiment.
[0100] The sleep improvement support device 200 according to the present exemplary embodiment may further include a propriety definition data storage unit 204 to store therein propriety definition data defining a affirmation-negation determining method for at least the chief complaint item and the chief complaint evaluation item included in the sleep-related data, similarly to the case of the first exemplary embodiment.
[0101] The sleep improvement support device 200 according to the present exemplary embodiment may further include a consistency definition data storage unit 205 to store therein consistency definition data defining the consistency of data of at least the chief complaint item and the chief complaint evaluation item included in sleep-related data, similarly to the case of the first exemplary embodiment.
[0102] The user of the present invention may be a consulter himself or herself, or a doctor or the like making a conversation with the consulter. If the user is a consulter, the CBT-I tool functions as a self-checking tool. Meanwhile, if the user is other than a consulter, the CBT-I tool functions as a tool that assists the doctor or the like making a conversation with the consulter. When operated by a person other than the consulter, the operator (user) may input information obtained from the consulter into the CBT-I tool, or give an advice or disclose data so as to remove anxiety of the consulter, with reference to messages displayed on the screen of the CBT-I tool.
INDUSTRIAL APPLICABILITY
[0103] Not limited to cases with insomnia, the present invention is suitably applicable to cases in which it is desired to easily detect the non-correlation relationship between a first phenomenon and a second phenomenon that would be susceptible to the occurrence of the first phenomenon.
[0104] As above, the present invention is described by using the above-described exemplary embodiments as examples. However, the present invention is not limited to the above-described exemplary embodiments. In other words, the present invention may be applied to various modes understood by those skilled in the art within the scope of the present invention.
[0105] The present application claims the priority based on Japanese Patent Application No. 2014-029709 filed on Feb. 19, 2014, the entire disclosure of which is incorporated herein by reference.
REFERENCE SIGNS LIST
[0000]
100 , 200 : sleep improvement support device
101 : chief complaint information input unit
102 : contradiction information extracting unit
103 : output unit
104 : sleep-related data storage unit
201 : contradiction information ranking unit
202 : chief complaint correspondence information storage unit
203 : sleep-related data input unit
204 : affirmation-negation definition data storage unit
205 : consistency definition data storage unit
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The challenge addressed by the invention is, in a case in which a consulter harbors a mistaken perception regarding the quality of his or her own sleep, to bring this to the attention of the consulter in a simple manner. In order to resolve this challenge, a sleep improvement support device is provided with: a sleep-related data storage unit ( 104 ) which stores two or more days' worth of sleep-related data including date information, sleep evaluation data for measuring the quality of the day's sleep, and quality evaluation data influenced by the quality of the day's sleep; a main complaint information input unit ( 101 ) which accepts as input main complaint information indicating the main complaint of the consulter; a contradiction information extracting unit ( 102 ) which extracts, from the stored sleep-related data, contradiction information indicating differences by day in the relationship between the data for a main complaint item, which is an item of sleep evaluation data corresponding to the main complaint of the consulter, and data for a main complaint evaluation item, which is an item of quality evaluation data corresponding to the main complaint of the consulter; and an output unit ( 103 ) which outputs the extracted contradiction information and/or a message based on the extracted contradiction information.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This patent application is a divisional of U.S. patent application Ser. No. 10/438,735, entitled “Collapsible Tortilla Support Apparatus,” filed on May 15, 2003 and assigned to the same assignee as this application.
TECHNICAL FIELD
[0002] This application generally relates to food packaging configured to be manipulated so that the packaging performs as a dinning support apparatus for transporting and supporting in an upright position tacos, tortillas, fajita wraps, gorditas, chalupas and the like.
BACKGROUND
[0003] Mexican food, particularly those dishes that utilize tacos and tortillas, has become very popular in the United States. The Mexican foods market, including the fast food, dine-in/sit down restaurant and the home production and consumption segments, has grown into a multi-billion dollar industry. Many individuals enjoy the fast food and restaurant version of Mexican taco and tortilla-based dishes, while many others prefer to construct their taco and tortilla-based dishes at home using fresh ingredients. However, the nature of many popular taco and tortilla dishes present several undesirable problems for taco and tortilla preparers and consumers.
[0004] One such problem encountered in preparation of tacos and tortillas is that, since taco shells have a rounded base and tortillas revert to a flat disc shape when not held in hand, it is very difficult to support taco shells and tortillas in an upright or manageably stable position while filling the taco and tortilla, respectively, with the desired ingredients, such as meat, beans, vegetables, and/or salsa, etc. Unfortunately, the taco and tortilla builder's effort often results in a mess wherein many of the taco ingredients end up outside the taco shell or in unmanageable proportions on tortillas during the construction process. There is therefore a need for a taco shell and tortilla support device, which will support tacos and tortillas in a position to reduce waste and mess and simplify the taco and tortilla filling process.
[0005] Moreover, following preparation of tacos and tortillas, tacos are presented on their side on a plate. This can lead to much of the taco filling falling out of the taco shell onto the plate. When tortillas are presented on a plate, they lay open and are presented as a mound of ingredients that tend to distribute all over the tortilla, thus causing the loss of tortilla fillings when the consumer picks up the tortilla filled with ingredients. Tacos and tortillas are currently transported and supported by plates, papers or an apparatus such as that disclosed in U.S. Pat. No. 6,019,224. When paper or plates are used as transport or support devices, they yield the undesirable need for action by the food consumer to replace or redistribute the taco and tortilla fillings in the tortilla shell. Further, the presentation of tacos and tortillas on paper or plates is not the most aesthetically pleasing method and could subtract from the entire eating experience.
[0006] Another problem that is occurring in the Mexican foods market, including the fast food, dine-in/sit down restaurant and the home production and consumption segments, is that there is substantial waste occurring as a result of the inefficient use of packaging and support materials. In the fast food, dine-in/sit down restaurant segment, tacos and tortillas are packaged and provided to the customer wrapped in paper. The paper is then discarded and the tacos and/or tortillas are supported and presented on a plate. In the home production and consumption segment, taco and tortilla kits are sold in boxes filled with taco and/or tortilla shells and fillings, including meat seasoning. In this environment the box used as packaging is discarded. The tacos and tortillas are then prepared and presented on their side on paper or a standard dinner plate. There is a need for taco and tortilla packaging that can serve as initial packaging and as the transport and support apparatus in the fast food, dine-in/sit down restaurant and the home production and consumption segments. The packaging needed would prevent waste associated with having separate packaging and support apparatuses.
[0007] Accordingly, there is a need for an improved tortilla packaging and support apparatus. The present invention provides a solution to many problems, such as those discussed above, currently faced in the industry.
SUMMARY
[0008] The present invention provides a tortilla support apparatus comprised of a collapsible, generally rectangular box having a base wall, a top wall, and an intermediate wall disposed between the base wall and the top wall. The apparatus further includes a sidewall assembly that is integrally coupled to the base wall and top wall, respectively. The collapsible tortilla support apparatus top wall includes tortilla-receiving apertures and the intermediate wall positioned below and substantially parallel to the top wall also includes tortilla-receiving openings. The tortilla receiving apertures of the top wall and intermediate wall are aligned so as to create tortilla-receiving chambers within the collapsible tortilla support apparatus. The base wall of the collapsible tortilla support apparatus also serves as the base wall of the tortilla-receiving chambers. The tortilla receiving apertures within the intermediate wall provide additional support and stabilization to tortillas positioned within the tortilla receiving chambers. The collapsible tortilla support apparatus is configured such that the side wall assembly, which is hingedly connected to the base wall and top wall provides for the expansion of the collapsible support apparatus to an upright tortilla support position and the collapsing of the tortilla support apparatus to a generally flat storage position.
[0009] These and various other features as well as advantages which characterize the present invention will be apparent from a reading of the following detailed description and a review of the associated drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a prospective view of a tortilla support apparatus of the present invention;
[0011] FIG. 2 is a prospective view of the tortilla support apparatus disclosed in FIG. 1 collapsed into its flat storage position;
[0012] FIG. 3 is a prospective view of an alternative embodiment of a tortilla support apparatus of the present invention;
[0013] FIG. 4 is a prospective view of the tortilla support apparatus disclosed in FIG. 3 illustrating the apparatus in its flat storage position;
[0014] FIG. 5 is a prospective view of an alternative embodiment of a popup collapsible tortilla support apparatus of the present invention;
[0015] FIG. 6 is a prospective view of the tortilla support apparatus disclosed in FIG. 5 illustrating movement of its sidewalls and support flaps into position which allow it to be collapsed into a flat storage position;
[0016] FIG. 7 is a prospective view of a popup tortilla support apparatus of the present invention with the advertising placard mounted thereon;
[0017] FIG. 8 is a prospective view of the popup tortilla support apparatus illustrated in FIG. 7 shown without the advertising placard; and
[0018] FIG. 9 is a prospective view of the popup tortilla support apparatus illustrated in FIG. 8 shown in its collapsed storage position.
DETAILED DESCRIPTION
[0019] The present invention is an improved tortilla support apparatus that is configured such that it may be manipulated from a flat storage position to a support position where it performs as a tortilla support apparatus that provides vertical support to tortillas. As used herein, the definition of the term “tortilla” refers to and comprises hard unshaped shells, soft taco shells, fajitas wraps, gorditas, chalupas and any other edible soft or hard shell food support device resembling hard and soft shell tacos, fajitas, gorditas, chalupas and wraps. In the embodiments of the invention disclosed herein, the tortilla support apparatus is configured such it may be collapsed from a generally rectangular configuration to it becomes flat. In its rectangular configuration, the tortilla support apparatus provides support to tortillas in an upright position, allowing the tortilla ingredients to be added and supported without spilling. The support apparatus includes a base wall, top wall and intermediate support wall. The base wall is the bottom of the support apparatus and supports the tortillas when positioned in the apparatus. The top wall is positioned above and generally perpendicular to the base wall. The top wall has tortilla-receiving openings formed therein, which receive tortillas position on the apparatus. The intermediate wall of the apparatus is positioned between and generally parallel to the base wall and the top wall and has tortilla-receiving openings formed therein. The intermediate wall tortilla-receiving apertures are directly below the tortilla-receiving openings formed in the top wall and provide enhanced support and stabilization for tortillas. The intermediate wall and top wall tortilla-receiving openings act in concert to create a tortilla-receiving chambers. The use of the intermediate wall and top wall and their respective tortilla-receiving apertures creates tortilla receiving chambers that provide additional middle range support on the body of a tortilla when positioned in such devices.
[0020] Embodiments of the tortilla support apparatus of the present invention are shown in FIGS. 1 through 9 . As illustrated in FIGS. 1 and 2 , a first embodiment of the collapsible tortilla support apparatus 100 includes first and second sidewalls 106 and 114 , third and fourth side walls 108 and 112 , abase wall 150 , and a curved top wall 110 . The first and second sidewalls 106 and 114 and the third and fourth sidewalls 108 and 112 are hingedly connected to the base wall 150 . In the preferred embodiment, the hinged connection between the base wall 150 and the first side wall 106 , the second side wall 114 , the third side wall 108 and the fourth side wall 112 is accomplished by a fold or crease formed in the construction material of the tortilla support apparatus 100 . A first hinged crease 160 is positioned between the base wall 150 and the third sidewall 108 . A second hinged crease 162 is positioned between the third sidewall 108 and the top wall 110 . Hinged crease 160 provides the hinge assembly necessary to permit the top wall 110 and the side wall 108 to be pivoted from the flat storage position illustrated in FIG. 2 to an upright position, as illustrated in FIG. 1 . Upon the pivoting of first side wall 106 and second side wall 114 to a position at which the first and second side walls 106 and 114 are perpendicular to the base wall 150 , the intermediate wall 130 is folded up and over the base wall 150 so that the intermediate wall 130 and the base wall 150 are generally parallel. Intermediate wall 130 is folded along a third hinged crease 164 between the base wall 150 and the first intermediate wall support sidewall 168 and along a fourth hinged crease 166 between the intermediate wall 130 and the first intermediate wall support sidewall 168 . Upon folding of intermediate wall 130 , the first intermediate wall support sidewall 168 becomes generally perpendicular to the base wall 150 and the intermediate wall 130 . Second intermediate wall support sidewall 172 is also folded along hinged second intermediate hinged crease 170 so that the second intermediate wall support sidewall 172 is generally perpendicular to the intermediate wall 130 . Intermediate wall is above base wall 150 in a generally parallel position at a distance the equivalent of the height of first and second intermediate wall support sidewalls 168 and 172 . In manipulating the collapsible tortilla support apparatus 100 to its upright position, the first and second sidewall tabs 116 and 118 are slid through a first sidewall tab receiving slot 124 and a second side wall tab receiving slot 122 . In addition, first and second sidewall tabs 142 and 144 are slid through first and second top wall tab receiving slots 146 and 148 .
[0021] As illustrated in FIG. 1 , collapsible tortilla support apparatus top wall 110 includes a plurality of tortilla receiving apertures 120 a , 120 b , 120 c , and 120 d , each which have a length of approximately 5-7 inches and a width of approximately one inch, although the dimensions may be modified as desired by the manufacturing of the present invention. The tortilla receiving apertures 120 a , 120 b , 120 c , and 120 d , are designed to receive a tortilla. The intermediate wall 130 also includes a plurality of tortilla receiving apertures 140 a , 140 b , 140 c and 140 d , each of which has a length of approximately one half inch shorter than the length of the tortilla receiving apertures of top wall 110 , and a width of approximately one fourth of an inch shorter than the width of the tortilla receiving apertures of the top wall 110 . It is to be understood that these dimensions may be modified as desired by the manufacture of the present invention. The tortilla receiving apertures 140 a , 140 b , 140 c and 140 d are designed to receive a tortilla and the aperture edges engage the external surface of the tortilla and provide medium range stabilization support to the center of the tortilla as the edges of the top wall tortilla receiving apertures 120 a , 120 b , 120 c , and 120 d engage the external surface of the tortilla and provide tortilla edge support to the top of the tortilla and thereby support the tortilla within the tortilla receiving chambers in a generally upright position.
[0022] The embodiment illustrated in FIG. 1 illustrates that the top wall 110 is curved to provide additional support for the tortilla supported therein. The top wall is curved in the present embodiment by way of bending the top wall 110 along a first top wall crease 152 , a second top wall crease 154 , a third top wall crease 156 and a fourth top wall crease 158 . The intermediate wall 130 also includes intermediate wall support side walls 168 and 170 formed by folding intermediate wall 130 along a first intermediate wall crease 166 and a second intermediate wall crease 170 . Intermediate wall 130 is positioned at a distance from bottom wall 150 that is the equivalent of the height of first and second intermediate wall support sidewalls 168 and 172 . In addition, there is a crease 164 as illustrated in FIG. 2 along which the first intermediate wall support side wall 168 is folded and is hingedly connected to the base wall 150 . The base wall 150 also includes a crease 160 between the base wall 150 and the third sidewall 108 . The third sidewall 108 further includes a folding crease, which provides the hinged attachment between the third sidewall 108 and the top wall 110 .
[0023] Another embodiment of the tortilla support apparatus is illustrated in FIGS. 3 and 4 . As illustrated, the collapsible tortilla support apparatus 300 includes a first side wall 306 , a second side wall 314 , a third side wall 308 , a fourth side wall 312 , a base wall 350 , and a top wall 310 . The first, second, third and fourth side walls 306 , 308 , 312 and 314 are hingedly connected to top wall 310 . The first sidewall 306 is hingedly connected to the top wall 310 via a hinged crease 362 . The second sidewall 314 is hingedly connected to the top wall 310 via a hinged crease 356 . The third sidewall 308 is hingedly connected to the top wall 310 via a hinged crease 364 . The fourth sidewall 312 is hingedly connected to the top wall 310 via a hinged crease 356 . In the preferred embodiment, the hinged crease connections between the top wall 310 and the sidewalls 306 , 308 , 312 and 314 is accomplished by a fold or a crease formed in the construction material of the tortilla support apparatus 300 .
[0024] FIG. 3 illustrates the collapsible support apparatus 300 in its upright position. In its upright position, the sidewalls and top walls have been folded along hinged creases in order to stabilize the collapsible tortilla support apparatus 300 in its upright position. As illustrated in FIGS. 3 and 4 , a first top wall crease 352 is formed between the top wall 310 and third sidewall 308 . A second top wall crease 356 is formed between the top wall 310 and a second sidewall 314 . A third top wall crease 362 is formed between top wall 310 and a first sidewall 306 . A fourth top wall crease 364 is formed between top wall 310 and a fourth sidewall 312 .
[0025] As illustrated in FIG. 3 , top wall 310 is generally parallel with intermediate wall 330 and bottom wall 350 and the distance separating top wall 310 from bottom wall 350 is the equivalent of the height of sidewalls 306 , 308 , 312 and 314 . The top wall creases which allow hinged movement of the side walls 306 , 308 , 312 and 314 in association with the top wall 310 also provides the hinged assembly necessary to allow the side walls and top wall 310 to be manipulated from the upright position illustrated in FIG. 3 to the flat storage position illustrated in FIG. 4 .
[0026] Following the pivoting of the first, second and third side walls 306 , 308 , 312 and 314 , to positions at which the first, second, third and fourth side walls 306 , 308 , 312 and 314 are generally perpendicular to the top wall 310 and base wall 350 , the intermediate wall 130 is folded up and over the base wall 350 so that the intermediate wall 330 and the base wall 350 are generally parallel. The intermediate wall 330 is folded along a hinged crease 364 between the base wall 350 and the first intermediate wall support sidewall 368 and along a fourth hinge crease 366 between the intermediate wall 330 and the first intermediate wall support sidewall 368 . Upon folding of intermediate wall 330 , the first intermediate wall support sidewall 368 becomes generally perpendicular to the base wall 350 and the intermediate wall 330 . Second intermediate wall support sidewall 372 is generally perpendicular to the intermediate wall 330 . Intermediate wall is above base wall 350 in a generally parallel position at a distance the equivalent of the height of the first and second intermediate wall support sidewalls 368 and 372 . In manipulating the collapsible tortilla support apparatus 300 to its upright position, illustrated in FIG. 3 , the first and second top wall tabs 342 and 344 are slid through a first top wall tab receiving slot 346 and a second top wall receiving aperture 348 .
[0027] As illustrated in FIGS. 3 and 4 , collapsible tortilla support apparatus top wall 310 includes a plurality of tortilla receiving apertures 320 a , 320 b , 320 c and 320 d . Each of the tortilla receiving apertures has a length of approximately 5-7 inches and a width of approximately one inch, although the dimension may be modified as desired by the manufacturing of the present invention. The tortilla receiving apertures 320 a , 320 b , 320 c , and 320 d are designed to receive a tortilla. The intermediate wall 330 also includes a plurality of tortilla receiving apertures 340 a , 340 b , 340 c , and 340 d , each of which has a length of approximately one half inch short of any length of the tortilla receiving apertures of top wall 310 , and a width of approximately one fourth of an inch shorter than the width of the tortilla receiving apertures of the top wall 310 . It is to be understood that these dimensions may be modified as desired by the manufacture of the present invention. The tortilla receiving apertures 340 a , 340 b , 340 c and 340 d are designed to receive a tortilla and the aperture edges engage the external surface of the tortilla and provide medium range stabilization support to the center of the tortilla as the edges of the top wall tortilla receiving apertures 320 a , 320 b , 320 c and 320 d engage the external surface of the tortilla and provide edge support toward the top of the tortilla. It is the medium range support of the tortilla receiving apertures 340 a , 340 b , 340 c and 340 d which provide the stabilization needed in collapsible tortilla support apparatuses.
[0028] As illustrated in FIG. 4 , the sidewalls 306 , 308 , 312 and 314 include sidewall support tabs. First sidewall 306 has first side wall support tabs 307 a and 307 b . Second sidewall 314 has second sidewall support tab 315 a . Third sidewall 308 has third sidewall support tab 309 a . Fourth sidewall 312 has fourth side wall support tabs 311 a and 311 b . Sidewall support tabs 307 a and 307 b , 309 a , 311 a , 311 b , and 315 a are engaged as illustrated in FIG. 3 to stabilize the tortilla support apparatus 300 in its upright position. The intermediate wall 330 also includes intermediate support walls 368 and 372 . Intermediate support wall 368 is formed by folding intermediate wall 330 along a first intermediate wall crease 366 which is between the base wall 330 and first intermediate wall support 368 . The second intermediate wall support sidewall 372 is formed by folding intermediate wall 330 along an intermediate wall crease 370 . Upon folding intermediate wall 330 along the first and second intermediate wall creases 366 and 370 , intermediate wall 330 is positioned at a distance from bottom wall 350 that is equivalent to the height of the first and second intermediate wall support side walls 368 and 372 . In addition, there is a crease 364 as illustrated in FIG. 4 along which the first intermediate wall support side wall 368 is folded and is hingedly connected to the base wall 350 . The base wall 350 also includes a crease 360 between the base wall 350 and the first sidewall 306 .
[0029] Another embodiment of the present invention is illustrated in FIGS. 5 and 6 . The embodiment illustrated is generally a popup box shaped tortilla support apparatus 500 having tortilla receiving apertures 520 a - d formed in the top wall of the collapsible tortilla support apparatus 500 , including an intermediate wall support system positioned within the collapsible tortilla support apparatus 500 . As illustrated in FIG. 5 , the embodiment of the collapsible tortilla support apparatus 500 includes a top wall 510 , a side wall assembly comprised of four side walls, a first side wall 512 , a second side wall 518 , a third side wall 522 and a fourth side wall 528 . The first, second, third and fourth side walls 512 , 518 , 522 and 528 are hingedly connected to the top wall 510 . In the preferred embodiment, the hinged connection between the top wall and the first, second, third and fourth side walls 512 , 518 , 522 and 528 is accomplished by a fold or crease formed in the construction material of the tortilla support apparatus. As illustrated in FIGS. 5 and 6 , a first hinged crease 562 is positioned between the top wall 510 and first sidewall 512 . A second hinged crease 564 is positioned between the top wall 510 and the second sidewall 518 . A third hinged crease 566 is positioned between the third sidewall 522 and the top wall 510 . A fourth hinged crease 568 is positioned between the fourth sidewall 528 and top wall 510 . Hinged creases 562 , 564 and 568 provide the hinged assembly necessary to permit the top wall and the sidewalls to be pivoted from the upright position illustrated in FIG. 5 to the flat storage position illustrated in FIG. 6 . Upon pivoting to the upright position of the collapsible tortilla support apparatus 500 , the sidewalls 512 , 518 , 522 and 528 are perpendicular to the top wall 510 , the intermediate wall 530 and the base wall 550 . The intermediate wall 530 also includes intermediate wall support sidewalls that support the intermediate wall and positions the intermediate wall substantially parallel to the base wall 550 when the collapsible tortilla support apparatus is in its upright position. The intermediate wall 530 includes intermediate wall tortilla receiving apertures 540 a , 540 b , 540 c , 540 d.
[0030] When the collapsible tortilla support apparatus 500 is collapsed, the second and fourth side walls 564 are pivoted along hinged creases 564 and 568 and provide the ability for the tortilla support apparatus 500 to be pivoted along hinged creases 562 and 566 into a flat storage position as illustrated in FIG. 6 . Second and fourth sidewalls 518 and 528 have second sidewall support flap 534 and a third side wall support flap 531 attached hereto. The support flaps 534 and 531 engage the base wall of the collapsible tortilla support apparatus 500 to stabilize the apparatus in an upright storage position.
[0031] As illustrated in FIGS. 5 and 6 , collapsible tortilla support apparatus top wall 510 includes a plurality of tortilla receiving apertures 520 a , 520 b , 520 c and 520 d , each having a length of approximately 5-7 inches and a width of approximately one inch, although the dimensions may be modified as desired by the manufacturing of the present invention. The tortilla receiving apertures 520 a , 520 b , 520 c and 520 d , are designed to receive a tortilla. The intermediate wall 530 also includes a plurality of tortilla receiving apertures 540 a , 540 b , 540 c and 540 d , each of which has a length of approximately one half inch shorter than the length of the tortilla receiving apertures of top wall 510 , and a width of approximately one fourth of an inch shorter than the width of the tortilla receiving apertures of the top wall 510 . It is to be understood that these dimensions may be modified as desired by the manufacturer of the present invention. The tortilla receiving apertures 540 a , 540 b , 540 c and 540 d are designed to receive a tortilla and the aperture edges engage the external surface of the tortilla and provide medium range stabilization support to the center of the tortilla as the edges of the apertures of the top wall 520 a , 520 b , 520 c and 520 d engage the external surface of the tortilla and provide the tortilla edge support to the top of the tortilla and thereby support the tortilla within the tortilla receiving chambers in a generally upright position.
[0032] As illustrated in FIGS. 7, 8 and 9 , another embodiment of the collapsible tortilla support apparatus 700 is shown to include first and second sidewalls 712 and 722 , a base wall 750 , and a top wall 710 . The first and second sidewalls 712 and 722 are hingedly connected to the top wall 710 and base wall 750 . In the preferred embodiment, the hinged connection between the base wall 750 and the first sidewall 712 , and the second side wall 722 is accomplished by a fold or crease formed in the construction material of the tortilla support apparatus 700 . A first hinged top wall crease 714 is positioned between the top wall 710 and the first sidewall 712 . A second hinged crease 716 is positioned between the first sidewall 712 and the base wall 750 . A third hinged top wall crease 718 is positioned between the top wall 710 and the second sidewall 722 . A fourth hinged crease 716 is positioned between the second sidewall 722 and the base wall 750 . Hinged creases 714 , 716 , 718 and 724 provides the hinge assembly necessary to permit the top wall 710 and the first and second sidewalls 712 and 722 to be pivoted from the upright position illustrated in FIGS. 7 and 8 to the flat storage position illustrated in FIG. 9 .
[0033] As illustrated, the collapsible tortilla support apparatus top wall 710 includes a plurality of tortilla receiving apertures 720 a , 720 b , 720 c , and 720 d , each which have a length of approximately 5-7 inches and a width of approximately one inch, although the dimensions may be modified as desired by the manufacturing of the present invention. The tortilla receiving apertures 720 a , 720 b , 720 c , and 720 d , are designed to receive a tortilla. The intermediate wall 730 also includes a plurality of tortilla receiving apertures 740 a , 740 b , 740 c and 740 d , each of which has a length of approximately one half inch shorter than the length of the tortilla receiving apertures of top wall 710 , and a width of approximately one fourth of an inch shorter than the width of the tortilla receiving apertures of the top wall 710 . It is to be understood that these dimensions may be modified as desired by the manufacture of the present invention. The tortilla receiving apertures 740 a , 740 b , 740 c and 740 d are designed to receive a tortilla and the aperture edges engage the external surface of the tortilla and provide medium range stabilization support to the center of the tortilla as the edges of the top wall tortilla receiving apertures 720 a , 720 b , 720 c , and 720 d engage the external surface of the tortilla and provide tortilla edge support to the top of the tortilla and thereby support the tortilla within the tortilla receiving chambers in a generally upright position.
[0034] As illustrated in FIGS. 7 and 8 , the tortilla receiving apertures 740 a , 740 b , 740 c and 740 d of the intermediate wall 730 are directly underneath tortilla receiving apertures 720 a , 720 b , 720 c , and 720 d of the top wall, thereby creating two levels of edge support and tortilla receiving chambers. Upon the pivoting of first and second sidewalls 712 and 722 up to a flat storage position at which first and second sidewalls 712 and 722 are parallel to the base wall 750 and top wall 710 , the intermediate wall 730 and the respective tortilla receiving apertures 740 a , 740 b , 740 c and 740 d are shifted over so that the apertures are no longer directly underneath the top wall tortilla receiving apertures 720 a , 720 b , 720 c , and 720 d as illustrated in FIG. 9 . This embodiment is a collapsible pop-up because it is manipulated into its upright position with no support other than the hinged creases 714 , 716 , 718 and 724 .
[0035] When the collapsible tortilla support apparatus 700 pops up from its resting position, a first intermediate wall support sidewall 726 becomes generally perpendicular to the top wall 710 , the base wall 150 and the intermediate wall 730 . Second intermediate wall support sidewall 728 is folded along a hinged crease so that the second intermediate wall support sidewall 728 is generally perpendicular to the intermediate wall 130 and parallel to the first side wall 712 . Intermediate wall 730 is above base wall 750 in a generally parallel position at a distance the equivalent of the height of first intermediate wall support sidewall 726 . FIG. 7 illustrates the embodiment illustrated in FIG. 7-9 as including an advertising placard 760 . The advertising placard 760 is mounted to on the second sidewall 722 . When collapsible tortilla support apparatus 700 I sin its generally flat storage position, the placard 760 also lays flat against the top wall 710 , or it could be folded in the opposite direction so long as the apparatus 700 lays flat. Upon the collapsible tortilla support apparatus 700 being expanded to its tortilla holder position as illustrated in FIG. 7 , the placard 760 extends upwards behind the tortillas being supported in the tortilla receiving apertures 720 a , 720 b , 720 c , and 720 d and can be printed upon to display various types of advertising. The placard 760 thus can provide a simple and vivid means of advertising for a business using or distributing the present invention.
[0036] While the invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various other changes in the form and details may be made therein without departing from the spirit and scope of the invention. The foregoing description of the exemplary embodiments of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many modifications and variations are possible in light of the above teaching. It is intended that the scope of the invention be limited not with this detailed description, but rather by the claims appended hereto.
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The present invention comprises a tortilla housing and support apparatus, configured to be manipulated so that the housing performs as a tortilla support device that provides vertical support to at least one tortilla. The tortilla housing and support apparatus is initially used as a tortilla-packaging box, such as tortilla boxes currently in use at supermarkets for housing tortillas. The tortilla housing has a configuration so that it may be manipulated from serving as packaging so that it performs as a tortilla support device.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority of German application No. 10 2005 053 022.2 filed Nov. 7, 2005, which is incorporated by reference herein in its entirety.
FIELD OF THE INVENTION
[0002] The invention relates to a method and to a device for executing the method for spatial presentation of a predeterminable examination area of an object under examination, with a plurality of two-dimensional projection data sets of the area under examination being recorded, with the axis of projection of the x-ray images essentially intersecting a common axis of examination at right angles, with the projection data sets being recorded in each case after a rotation of the axis of projection around the examination axis.
BACKGROUND OF THE INVENTION
[0003] Spatial or three-dimensional views of objects to be examined are a major component of diagnostics in medical engineering and are of great importance for the planning and execution of medical interventions. The improved capabilities for analyzing complicated structures within an object to be examined provided by spatial presentation reassure patients and reduce the time spent in planning and undertaking medical interventions. A spatial presentation is of particular advantage for vessel systems to allow a better overview to be obtained. A plurality of different methods for creating a three-dimensional image of an object to be examined is currently known.
[0004] Such methods include 3D x-ray systems, especially computer tomography and C-arm systems, magnetic resonance tomography, 3D ultrasound, etc. With currently known x-ray methods which can be employed for interventional treatments it is not possible to examine areas which are larger than the x-ray bundle used for penetrating the object under examination.
[0005] Patent application DE 101 40 862 B4 discloses a medical x-ray examination device with a pedestal, with a guide rail mounted on the pedestal, with a first carriage mounted on the guide rail and able to be moved along it, with an x-ray imaging system mounted on the first carriage, and with a patient support device. A second carriage mounted on the guide rail and able to be moved along said rail, on which the patient support device is mounted via an outrigger arm, allows the number of possible x-ray examinations to be increased and makes the system more user-friendly for those operating it.
[0006] A method for reconstruction of 3D image data relating to a volume of interest of an object to be examined is known from application DE 199 62 666 A1, in which a plurality of 2D central projections is obtained from different projection directions by means of a flat-panel detector and rays emanating from an a x-ray source. The disadvantage of this method is that only a restricted area can be investigated during an examination, said area being limited by the size of the flat-panel detector. Examination areas which have dimensions larger than the spatial extent of the x-ray bundle used can only be covered by executing an examination a number of times and then going through the tedious process of combining the results.
SUMMARY OF THE INVENTION
[0007] The object of the invention is to provide a generic method and also a generic device with which the speed of examination can be increased for an extended area of an object under examination.
[0008] The part of the object to be achieved by the method described at the start of this document for spatial presentation of a predeterminable area of an object under examination is achieved by overlaying the rotation of the projection axis onto an offset along the axis of examination, so that image data sets for non-recorded projection axes are interpolated from the recorded projection data, and that a spatial presentation of the area under examination is created from the projection and image data sets.
[0009] The axis of projection is usually taken to mean the central ray of the x-ray bundle which an x-ray source emits in a specific direction and which is detected by an x-ray detector, in connection with a specific piercing point of the object under examination. This means that the same projection directions for different piercing points of the central ray are different axes of projection. The axis of examination can for example be viewed as the longitudinal axis of a human body. Alternatively, where no longitudinal axis of a body can be detected, the longitudinal axis of the patient table can be identified as this axis, which is shifted in parallel at the height of the center point of the object to be examined. As a rule the axis of examination always essentially intersects the plane spanned by an x-ray C-arm at right angles.
[0010] The area to be examined can exceed the extents of the x-ray bundle during the penetration of the object under examination. The predetermination of the area of the given object to be examined, by the medical personnel for example, allows precisely the relevant subarea of the object under examination to be examined efficiently as regards time. If the examination is started after all the necessary parameters have been set, the method for spatial presentation then generally runs automatically.
[0011] The x-ray bundle passing through an examination object has a finite extent which extends for current x-ray systems from a few millimeters, e.g. for computer tomography applications, up to several tens of centimeters, e.g. for C-arm x-ray systems. Because of the extent of the bundle, the latter feature two-dimensional projection data sets, whereas the former can be designated as zero-dimensional data sets.
[0012] With the use of x-ray systems for which the dimensions of the x-ray bundle are in the centimeter range, a spatial projection of the x-rayed area can be determined directly from projection data sets recorded from a number of projection directions. With the use of x-ray systems, of which the ray bundle extent lies within the millimeter range only one layer of the object under examination can be reconstructed.
[0013] However a three-dimensional presentation can still be realized from reconstructed layers of the area under examination. Only one projection data set is created by means of x-ray imaging for each subsection of the area under examination by means of the inventive method. Image data sets of the same subsection of the area under examination for further projection directions can be interpolated from further, suitable x-ray images. This requires the central rays of adjacent projection data sets with the same projection directions to not be further away from each other than the extent of the x-ray bundle in the direction of movement.
[0014] This means that an image data set for these projection directions can be interpolated from adjacent data sets recorded in the same projection directions lying between the adjacent recorded data sets. This interpolated image data set delivers a projection data set for a section of the area under examination, which was only recorded from another direction of projection. Thus interpolated image data sets with different projection directions exist for the same subsection of an area under examination as well as a recorded projection data set with a projection direction with a projection direction which is likewise different from the projection direction of the image data sets.
[0015] Any number of projection data sets can be interpolated to image data sets from different projection directions. There are thus sufficient data sets available for a subsection of an area under examination, so that by reconstructing the two-dimensional data sets a three-dimensional image of the area under examination or of the subsection of the area under examination can be created.
[0016] It is advantageous in this case that only one x-ray image has to be recorded for each direction of projection and each examination subsection. This means that both the x-ray dose for the patient is reduced and the speed of the examination process is also increased.
[0017] In a particular embodiment of the invention a C-arm x-ray imaging system is used to record the two-dimensional projection data sets. This is because it is with precisely these types of device that a large bundle extent of the x-ray bundle passing through the examination object is produced as well as the option of rotating the x-ray imaging system around the object under examination. In particular the inventive method can generally be easily employed with existing C-arm x-ray systems. This allows a low-cost introduction of the inventive method. This especially also enables patient throughput to be increased.
[0018] In a further advantageous embodiment of the invention the area under examination is moved along at the axis of examination in order to move the axis of projection along the axis of examination, while a system for recording x-ray images is not moved. This means that the x-ray device itself does not make any translational movements but only one rotational movement, whereas the object under examination is moved continuously or in stages during the examination process along the axis of examination. This can be done for example by moving a patient table on which the object to be examined is positioned. The patient table as a rule has a lower inertia than the system required to record the x-ray images. This means that lower friction and energy consumption can be expected, which reduces operating costs.
[0019] In a further advantageous embodiment of the invention, to move the axis of projection along the axis of examination, the x-ray recording system is moved along the axis of examination while the area under examination is not moved. This variation of the method can be required if space restrictions mean that it is impossible to move the patient table but it is possible to move the x-ray recording system. Thus the system for recording x-ray images is guided over the predetermined examination area of the object under examination. This means that the x-ray imaging system makes both a translational and also a rotational movement.
[0020] The appropriate guides or robot systems are necessary to implement a translational movement of an x-ray imaging device. In a preferred form patient table and x-ray imaging system can be moved simultaneously against one another along at the axis of examination. This makes sense if neither of the two components, i.e. patient table and x-ray imaging system, has the necessary speed of movement to achieve the speed advantage of the inventive method.
[0021] The limit of the relative forwards movement is reached as a rule if, for the backwards and forwards rotation of the rotatable x-ray system, the projection data sets obtained by the movement no longer border on each other for the same directions of projection. For small distances between adjacent, no longer overlapping projection data sets of the same direction of projection, projection data sets can if necessary be interpolated between the no longer overlapping projection data sets. On the one hand this can lead to a reduction of the reliability of the examination results, on the other hand to an acceleration of the examination.
[0022] The critical speed of the relative advance is defined by the maximum distance of a defined position of the projection data sets which are now no longer overlaid and the time which the x-ray recording system needs to move from the first reversing point of the rotation to the second reversing point of the rotation and back again, and thereby has a suitable image recording rate of for example 30 images per second. The order of magnitude of the critical speed of the relative advance can be estimated for a Siemens Axiom Artis Dyna CT system currently available on the market at a few centimeters per second.
[0023] The speed of critical advance can be increased much more by improved rotational drives, especially orbital drives, with higher speeds of rotation and an x-ray imaging system with suitable image recording rates.
[0024] In a preferred embodiment of the invention the rotation is carried between two specified reversing points. This means that the method can be undertaken by means of precisely one x-ray source and precisely one x-ray detector. The x-ray source and the x-ray detector are rotated around the axis of examination and thereby around the object under examination up to a first reversing point, while images, i.e. two-dimensional projection data sets, are being recorded at defined intervals. At the reversing point the x-ray imaging system reverses its direction of rotation and rotates in the opposite direction to a second reversing point. Further projection data sets continue to be recorded during this process.
[0025] Alternatively a number of x-ray sources and x-ray detectors which are aligned on different projection directions can be present while a relative movement of the object under examination in relation to the x-ray imaging system is undertaken. With more than precisely one x-ray source and precisely one x-ray detector a choice can be made as to whether a rotation between two reversing points occurs during the examination, or an even or possibly no rotation is required for the x-ray imaging systems.
[0026] In a further advantageous embodiment of the invention x-ray images are recorded independently of the direction of rotation. The fact that images of two-dimensional projection data sets are recorded not just in the forwards or the backwards rotation but in both the forwards and backwards rotation of the x-ray imaging system allows the throughput time to be increased by a factor of two with all other conditions remaining the same, or enables the time needed for performing an examination to be reduced by a factor of two.
[0027] In a further preferred embodiment of the invention x-ray images are recorded without interrupting the rotation. Associated with this is the requirement for the x-rays to be taken in a period in which the x-ray imaging system is semi-immobile. This means that the rotational movement of the x-ray imaging system within the measurement interval must be negligible, since otherwise artifacts are produced which can falsify the examination results, unless these results are corrected. If it is possible to correct the artifacts the above-mentioned condition does not apply. The recording of x-ray images without reducing the angular speed of the x-ray imaging system also reduces the examination time needed.
[0028] In an alternative embodiment of the invention at least one x-ray image is recorded after interruption of the rotation. This can be required for example is an image of an organ is to be recorded in a specific state of movement. However this can also be adopted as a general recording concept if for example the movement of the x-ray imaging system at a specific angular speed in the measurement interval for recording the x-ray image is not negligible.
[0029] For example the angular speed of the x-ray imaging system is reduced until it comes to a standstill. The projection data set is then recorded in a specific direction of projection. Subsequently the x-ray imaging system put into motion again to move to the next position in order to record a further projection data set at a specific changed direction of recording there etc. With this recording movement too an expanded recording movement for an examination area of an object under examination is possible.
[0030] In a further advantageous embodiment of the invention an interpolation from projection data sets with parallel axes of projection in each case is undertaken. It is especially advantageous for this purpose to use adjacent projection data sets for the same projection directions. Furthermore it is advantageous if projection data sets used for interpolation have a spatial overlapping area for the same projection directions. This enables a two-dimensional image data set for the same projection directions to be determined without any loss of quality and to be related to a recorded projection data set.
[0031] The interpolation can be performed for each projection direction for which at least two projection data sets have been recorded. Any number of interpolated projection data sets can be recorded for each projection direction. The accuracy of the examination result in direction of the examination axis can then be increased as required for a defined number of projection directions and in practice depends solely on the computing capacity of the existing data processing device.
[0032] In a further preferred execution variant, in the time before the first x-ray image is recorded, a simulation of the rotation of the axis of projection, which is overlaid with a movement of the axis of projection along the axis of examination in accordance with the predetermined examination area, is undertaken. This allows collisions between the x-ray imaging system and/or the support device and thus damage to the x-ray system and also to the equipment of the medical working environment or the personnel to be avoided.
[0033] This expediently requires the position of the devices present in the environment to be recorded, which can be done by means of sensors for example. The sensors are connected to the controller which supplies the information about the position of the devices in the area of the simulation. This enables the danger of a collision to be detected at an early stage, without damage being done to the equipment or the x-ray system. If necessary a test run of the x-ray imaging system can be performed before the start of the examination.
[0034] In particular a method for spatial presentation of a predeterminable examination area of an object under examination is advantageous, with a plurality of two-dimensional projection data sets of the area under examination being recorded by x-ray images, with the axes of projection of the x-ray imaging system essentially intersecting a common axis of examination at right angles, with the projection data sets being recorded after a rotation of the axis of projection around the axis of examination in each case, with the rotation of the axis of projection being overlaid with a movement of the axis of projection along the axis of examination, with two-dimensional image data sets for axes of projection not recorded being interpolated from the recorded two-dimensional projection data sets such that from adjacent two-dimensional projection data sets essentially adjoining one another in their recording area of parallel axes of projection two-dimensional, preferably seamless image data sets are determined, and that from the two-dimensional projection and two-dimensional image data sets a spatial presentation of the area under examination is created.
[0035] The part object to be achieved by the device is achieved by an x-ray system with a support device for an object under examination which can be moved along an axis of examination with an predeterminable area of examination, with an x-ray imaging system movable along the axis of examination, with the x-ray imaging system comprising an x-ray source and an x-ray detector, between which an axis of projection extends centrally in a straight line, with the x-ray imaging system being arranged rotatably around the object under examination, with means for driving the movable support device and/or the movable x-ray imaging system, with a control, by which the drive means and the x-ray imaging system can be controlled such that the movement of the axis of projection can be overlaid with a movement of the axis of projection along the axis of examination, with a data processing unit, with which data sets can be stored and can be processed, as claimed in one of the claims, and with an image display unit for spatial presentation of the area under examination.
[0036] In an advantageous embodiment of the invention the x-ray imaging system is embodied as a C-arm x-ray imaging system. A C-arm x-ray imaging system is especially suitable for the method in accordance with the invention, since C-arm x-ray imaging systems are very widely used in clinical environments. This enables the inventive method to be used simply by modifying control instructions and/or by adding the necessary inventive equipment components.
BRIEF DESCRIPTION OF THE DRAWINGS
[0037] Further advantages of the inventive method emerge from an exemplary embodiment, which is explained below in greater detail on the basis of the drawing in which
[0038] FIG. 1 shows an arrangement for executing of the method in accordance with the invention,
[0039] FIG. 2 shows a diagram for creating interpolated image data sets as schematic illustrations.
DETAILED DESCRIPTION OF THE INVENTION
[0040] FIG. 1 shows an x-ray system 1 , which features a support device 2 for supporting an object under examination U, as a rule the body of a human or of an animal. For the object under examination U, an extended area under examination U B is to be examined by means of the x-ray system 1 . The object under examination U is adapted to the x-ray system 1 , positioned on the support device 2 and aligned along an axis of examination 3 .
[0041] In the exemplary embodiment the axis of examination 3 matches the longitudinal axis of the body of the object under examination U shown. A C-arm type x-ray imaging system 4 is used to record the required data sets. This has an x-ray source 5 and an x-ray detector 6 positioned opposite the x-ray source 5 . These are rigidly connected to each other by a C-shaped arm.
[0042] The center point of the x-ray source 5 and the center point of the x-ray detector 6 are connected to each other by a virtual axis of projection, which generally coincides with the direction of the central ray of the x-ray bundle emitted by the x-ray source 5 . The axis of projection changes its location and its direction during the course of the examination and in FIG. 1 coincides with an axis of projection 72 . The x-ray imaging system 4 is support to allow movement along the axis of examination 3 . The support device 2 can also be moved along the axis of examination 3 . Furthermore the C-arm 4 is supported so as to enable it to be rotated around the object under examination U.
[0043] Both the longitudinal movement of the C-arm 4 and of the support device 2 as well as the rotation of the C-arm 4 around the object under examination U are driven by means a drive element 9 . The drive element 9 is connected to a controller 10 which controls the forwards movement of the C-arm 4 or of the support device 2 , the speed of rotation of the C-arm 4 around the object under examination U as well as the image recording of the C-arm 4 .
[0044] Two-dimensional projection data sets are recorded by means of the x-ray imaging system 4 while this system is being rotated around the object under examination U and moved in relation to the object under examination U. In this case the x-ray imaging system 4 uses the highest possible image recording rate of for example 30 images per second. For the starting point of the examination the C-arm 4 is positioned so that the x-ray bundle still sufficiently passes through the start of the area under examination U B , with the axis of projection being freely selectable in the start position.
[0045] After the start the support device 2 is accelerated at a constant speed of movement of one centimeter per second in the direction opposite to the position of the area under examination U B . Simultaneously the C-arm 4 begins with the image recording and the rotation around the object under examination U. Within the area under examination U B of the object under examination U the course of the totality of the intersection points 14 of the axes of projection with the surface of the object under examination U is illustrated schematically.
[0046] The overlaying of the movement of the object under examination U against the x-ray imaging system 4 along the axis of examination 3 in connection with the rotation of the x-ray recording system 4 around the object under examination U produces the course of the intersection points 14 of the totality of the axes of projection with the surface of the object under examination U shown. The rotation of the x-ray system 4 features reversing points 13 . There are two reversing points 13 , namely, a reversing point 13 on the left and the right looking along the axis of examination 3 of the x-ray imaging system 4 . The course of the intersection points 14 of the totality of the axes of projection with the surface of the object under examination can advantageously be changed by changing the direction of movement of the object under examination U against the x-ray imaging system 4 and changing the direction of rotation of the x-ray imaging system 4 —at the discretion of the specialist personnel.
[0047] During the recording movement a plurality of projection data sets is recorded which is forwarded to a data processing unit 11 . The examination lasts until the end of the area under examination U B is reached. The projection data sets are stored in the data processing unit 11 and, where possible, processed as the examination is underway.
[0048] The data processing unit 11 executes an interpolation of the same projection directions for adjacent projection data sets. Image data sets are determined between the two projection data sets used in each case for the same projection directions which have a predeterminable increment.
[0049] The increment describes the spatial displacement between two image data sets of the same projection direction adjacent in their recording area. The increment of the image data sets determined between the two adjacent projection data sets of the same projection direction corresponds expediently in this case to the distance along the axis of examination 3 between two projection data sets immediately following one other in different directions of projection. This allows the increment of the interpolated image data sets to be reconciled with the increment of the projection data sets. A plurality of interpolated image data sets is now determined for two adjacent projection data sets of the same projection direction in each case.
[0050] Image data sets can be interpolated for all directions of projection for which at least two adjacent projection data sets of the same direction of projection are available which border on each other in the recording area.
[0051] A reconstruction for spatial presentation of the entire examination area U B , which is output on the display unit 12 and is available to a medical personnel in the data processing unit 11 , is also calculated from the image data sets determined in conjunction with the recorded projection data sets. This allows a larger examination area U B of the object under examination U to be examined.
[0052] FIG. 2 shows an object under examination U which features an area under examination U B and extends along an examination axis 3 . Four axes of protection are shown for example in the area under examination U B which are paired in the same direction and for which one direction of a pair is orthogonal to the direction of the other pair in each case as well as to the direction of the axis of examination 3 .
[0053] The axes of projection represent the direction of recording of the projection data sets and their recording position on the object under examination U. Thus the number of the axes of projection occurring in an examination depends on the relative speed of movement of the object under examination U in relation to the x-ray imaging system 4 from FIG. 1 , the image recording rate of the x-ray imaging system 4 from FIG. 1 and also the position of the reversing points 13 from FIG. 1 of the x-ray imaging system 4 from FIG. 1 etc.
[0054] FIG. 2 shows a first pair of projection axes 71 or 72 to which two-dimensional projection data sets 71 ′ and 72 ′ are assigned. The projection data sets 71 ′ or 72 ′ are adjacent and have the same directions of projection.
[0055] Furthermore the projection data sets 71 ′ or 72 ′ directly border on one another in their recording area. Shown in the Figure rotated at 90 degrees around the axis of examination 3 and moved along the axis of examination 3 is a second pair of projection axes 81 or 82 to which the projection data sets 81 ′ and 82 ′ are assigned. These projection data sets 81 ′ or 82 ′ also border on each other and have the same projection directions but differ from the first pair of projection data sets 71 ′ or 72 ′ in that their projection direction is rotated by 90 degrees to the projection directions of the first pair 71 ′ or 72 ′.
[0056] Furthermore the piercing point of the axis of examination 3 is different for each projection axis 71 or 72 or 81 or 82 different, which is caused by the movement of the object under examination U in relation to the x-ray recording system 4 from FIG. 1 .
[0057] The projection data sets 71 ′ or 72 ′ or 81 ′ or 82 ′ represent images of the area under examination U B . Since these directly border one another, the method can be ideally exploited.
[0058] As can be seen from FIG. 2 , any number of image data sets 73 ′ with different proportions of the projection data sets 71 ′ and 72 ′ can be interpolated from the projection data sets 71 ′ or 72 ′. Likewise any number of image data sets 83 ′ with different proportions of the projection data sets 81 ′ and 82 ′ can be determined from the projection data sets 81 ′ or 82 ′.
[0059] If projection data sets do not border on each other but overlap in their recording area, redundant information is produced in the projection data sets 71 ′ or 72 ′ or 81 ′ or 82 ′, which reduces the speed of the method. If the recording areas of adjacent projection data sets 71 ′ or 72 ′ or 81 ′ or 82 ′ are spaced from each other so that they neither overlap nor directly adjoin one another, the quality of the examination result since information about the object under examination is not recorded.
[0060] FIG. 2 shows that with the aid of the interpolation of two adjacent which border one another in their recording area 71 ′ or 72 ′ and 81 ′ or 82 ′ if the same direction image data sets can be created which no longer differ from a projection data set in the point of intersection of the axis of examination 3 but only by being rotated at 90 degrees.
[0061] This is the case for example for projection data set 82 ′ and 73 ′ as well as for 71 ′ and 83 ′. A complete set of two-dimensional data sets can be created from these relevant projection and image data sets for a relevant subsection of the area under examination U B , to make possible a reconstruction of a spatial presentation of the area under examination.
[0062] FIG. 2 shows image data sets 73 ′ or 83 ′ which are each made up of about 50 percent of the associated respective projection data sets 71 ′ or 72 ′ or 81 ′ or 82 ′. However the composition of the image data set 73 ′ is for example freely selectable, for example 10 percent of projection data set 71 ′ and 90 percent of projection data set 72 ′.
[0063] The composition of the image data set 73 ′ or 83 ′ is however directly connected to the above-mentioned increment. By changing the percentage share of the relevant projection data set 71 ′ or 72 ′ or 81 ′ or 82 ′ the increment of the interpolated image data set 73 ′ or 83 ′ can be varied along the axis of examination 3 and the increment of the interpolated image data sets 73 ′ or 83 ′ can be adapted to the increment of the recorded projection data sets 71 ′ or 72 ′ or 81 ′ or 82 ′.
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The invention relates to a method and a device for executing the method for spatial presentation of a predeterminable area under examination. By overlaying a movement of the axis of projection along an axis of examination onto a rotation of an axis of projection around the object under examination, and by interpolating from the recorded projection data sets image data sets for axes of projection not recorded, and by creating a spatial presentation of the area under examination from the projection and image data sets, a method and a device can be provided which increases the speed of an examination for an extended area under examination of an object under examination.
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This application is a continuation of application Ser. No. 473,922, filed Mar. 10, 1983, now abandoned.
BACKGROUND OF THE INVENTION
This invention relates to novel polymerizable imidazolidinone monomers, their preparation, and their use to form self-crosslinking polymers which are thermosettable without the release of formaldehyde. It also relates to the use of such polymers in emulsion form as nonwoven binders.
It is well-known in the art to employ self-crosslinking polymers, either in emulsion or solution form, as coatings, binders, or adhesives for a variety of substrates. Self-crosslinking polymers are distinguished from crosslinkable polymers in that the latter contain a functionality, such as a carboxyl group, which can only be crosslinked by the addition of a co-reactant (i.e., crosslinker) to the polymer emulsion or solution. A typical crosslinkable system can be represented as follows: ##STR4##
In contrast, self-crosslinking polymers contain a functionality which is self-reactive and consequently do not require the use of a coreactant species per se. A typical self-crosslinking system can be represented as follows: ##STR5##
The advantages of the self-crosslinking polymer systems are their simplicity, economy, and particularly their efficiency. Such systems have been used as textile adhesives, non-woven binders, pigment binders for glass fabrics, and fabric finishing agents for hand and weight modification. On curing, such systems produce textile products with excellent durability to washing and dry cleaning. They have also been used in pigment printing and dyeing and as a binder for paper.
Both the self-crosslinking and crosslinkable polymer systems of the prior art suffer from the disadvantage that toxic free formaldehyde is present either during the curing or the preparation of the polymers. The self-crosslinking systems, which are typically formaldehyde-amide polymeric adducts containing methylolacrylamide repeating units, liberate formaldehyde during curing of the crosslinked thermoset polymer. The crosslinkable systems, which are typically based on urea-formaldehyde or melamine-formaldehyde resins and crosslinkers, may contain residual free formaldehyde.
In addition to the odor problems created by the presence of free formaldehyde, the dermatitic effect is a serious problem. The exposure of operating personnel and cosumers to formaldehyde has been a recent concern of both industry and regulatory agencies. This has lead to the search for formaldehyde-free systems, especially self-crosslinking, formaldehyde-free systems for use as nonwoven binders.
SUMMARY OF THE INVENTION
The present invention provides, as a composition of matter, an imidazolidinone of the general structure: ##STR6## wherein R 1 is hydrogen or a C 1 -C 6 linear or branched alkyl group when attached to a nitrogen; X is a divalent radical selected from the group consisting of ##STR7## with R being a hydrogen or a methyl group, with m being an integer from 0 to 5, and with n being an integer from 1 to 5, preferably m or n being 1; R 2 is hydrogen or a methyl group; R 3 is hydrogen or a ##STR8## group with R 1 being hydrogen or a linear or branched C 1 -C 6 alkyl or hydroxyalkyl when attached to an oxygen; and R 4 and R 5 are independently hydrogen or a linear or branched C 1 -C 4 alkyl group.
It also provides homopolymers and polymers thereof with monomer(s) containing at least one ethylenically unsaturated group.
In a preferred embodiment it provides emulsion (latex) polymers containing about 1-15%, preferably 3-6%, by weight of the above monomers and about 85-99%, preferably 94-97%, of an ethylenically unsaturated monomer, such as ethylene, vinyl acetate, ethyl acrylate, butyl acrylate, methyl methacrylate and the like, for use as formaldehyde-free binders for nonwoven textiles. A typical polymer contains about 45-60% vinyl acetate, 34-52% butyl acrylate, and about 3-6% of the self-crosslinking imidazolidinone.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The novel monomers herein are typically prepared by reacting an ethylenically unsaturated urea derivative with glyoxal. The urea derivatives are usually well known compounds previously reported in the chemical literature. Methods for their preparation are described in Synthetic Organic Chemistry by R. B. Wagner and H. D. Zook, John Wiley & Sons, 1963, p. 645. Two suitable methods include the reaction of isocyanates with amines, ##STR9## wherein R or R' may be an unsaturated group, and the reaction of amines with urea, i.e. ##STR10## wherein R" is an unsaturated group.
In the typical isocyanate reaction, the isocyanate compound is dissolved in an aprotic dry solvent such as toluene at about 40% concentration. The entire reaction system is protected from moisture by suitable drying tubes, inert gas purge, or the like. The amine is slowly added to the solution at a temperature not exceeding 10°-15° C. In the case of ammonia or simple alkyl amines, this component is a gas and it is bubbled subsurface. The reaction is exothermic and adequate cooling may be required. The urea derivative usually precipitates as it forms and may be recovered from the reaction mixture by filtration. The derivative is then washed and dried.
In the typical amine reaction, the amine and urea are combined and heated at 120°-150° C. with the evolution of ammonia. When the reaction mixture reaches the required weight, the heating is stopped and the solid mass is recrystallized to recover the urea derivative.
In the imidazolidinone preparation, the urea compound is dissolved in sufficient water and gloxal to provide a solution of about 50% theoretical solids (based on imidazolidinone being prepared). The glyoxal reagent, used in stoichiometric amounts, may vary in form (e.g. 40% aqueous solution, 80% powder, p-dioxane diol, or the like). The pH of the mixture is adjusted to 7-7.5 with sodium hydroxide. Heat is applied to raise the temperature of the mixture to 45°-80° C. to effect complete reaction. The reaction is monitored by titrating for glyoxal content. When the reaction is complete, the monomer solution is generally diluted to 40% solids by the addition of water and the diluted mixture treated with activated charcoal. When the hydroxyl groups of the imidazolidinone ring are substituted with alkyl groups, suitable starting materials for the imidozolidinones may be prepared using well-known methods described in Synthesis 243 (1973a).
The above imidazolidinone monomers are useful as vinyl polymerizable monomers (i.e. monomers polymerizable by vinyl type polymerization procedures). They may be used to form homopolymers or their mixtures may be used to form polymers thereof. They may also be used to form addition polymers with other ethylenically unsaturated monomers. The polymers may be prepared by solution, emulsion, precipitation, suspension, or bulk polymerization techniques. The preferred method is emulsion polymerization.
Suitable comonomers include one or more monomers containing at least one ethylenically unsaturated group such as (meth)acrylonitrile; (meth)acrylic acid and the esters, amides and salts thereof; itaconic acid and its functional derivatives, preferably the esters; maleic anhydride; maleic and fumaric acids and the esters thereof; vinyl ethers and esters; styrene; ethylene; vinyl and vinylidene chlorides; and the like.
The preferred addition polymers for use as formaldehyde-free binders for non-woven textiles are polymers containing about 1-15%, preferably 3-5%, by weight of the above imidazolidinone monomers and about 99-85%, preferably 97-95%, by weight of one or more ethylenically unsaturated monomers such as ethylene, vinyl acetate, ethyl acrylate, butyl acrylate, or methyl methacrylate. The preferred imidazolidinone monomers for this use include 3-(methacryloxyethyl)-4,5-dihydroxy-2-imidazolidinone, 1-ethyl-3-allyl-4,5-dihydroxy-2-imidazolidinone, and 3-allyl-4,5-dihydroxy-2-imidazolidinone.
The following examples will more fully illustrate the embodiments of this invention. In the examples, all parts and percentages are given by weight and all temperatures are in degrees Celsius unless otherwise noted.
EXAMPLE I
This example describes the preparation of the 3-(methacryloxyethyl)-4,5dihydroxy-2-imidazolidinone (MEDHEU). The two-step reaction sequence was as follows: ##STR11##
A three liter round bottom flask equipped with a thermometer, agitator, condenser, drying tube and a gas inlet tube was charged with 1500 ml. of 3 A° sieve dried toluene and 340 g. (2.195 moles) of β-isocyanatoethyl methacrylate. With agitation, the mixture was cooled to 5° C. in an ice bath. While maintaining the reaction temperature at 5°-10° C., 39.6 g. ammonia gas was bubbled subsurface over a period of 7 hrs. After the addition was completed, the temperature of the reaction mixture was allowed to rise to 25° C. The precipitated urea product was recovered by filtration, washed with fresh toluene, and dried in a vacuum dessicator to constant weight. Yield was 369 g. (98%). IR analysis (1715 cm -1 , 1685 cm -1 , 1600 cm -1 ) and nitrogen analysis (16.3%) were consistent with mono-substituted urea structure of N-methacryloxyethyl urea.
A one-liter four neck flask equipped with an agitator, thermometer, condenser and pH electrode/meter was charged sequentially with 13 g. distilled water, 95.6 g of 43.6% aqueous glyoxal solution, 0.25 g. monomethyl ether of hydroquinone, and 125 g. of the above urea. The mixture was agitated until complete solution was achieved. The pH of the mixture was adjusted to 7.0-7.5 with 6.25N NaOH (25% W/V) and the mixture was heated at 60° C. for 5 hr. At the end of this period, analysis for glyoxal indicated 95% reaction. The mixture was diluted with 597 g. distilled water, purified by slurrying with 8.3 g. of a high surface area activated charcoal, and filtered through diatomaceous earth. The active solids content was 20% MEDHEU.
EXAMPLE II
This example describes the preparation of 1-ethyl-3-allyl-4,5-dihydroxy-2-imidazolidinone (EADHEU). The two-step reaction sequence was as follows: ##STR12##
A two-liter reactor equipped with an agitator, thermometer, condenser with drying tube and equalized dropping funnels was charged with 800 ml. of sieve dried toluene and 80 g. allyl amine. With agitation, the mixture was cooled to 10° C. and 100 g. of ethylisocyanate was added over a 2 hr. period. The reaction was exothermic and the temperature was maintained at 10°-15° C. throughout the addition by external cooling. After the addition was completed, the toluene was vacuum distilled from the mixture at 40° C./20 mm. Hg. The viscous liquid was titurated with heptane to precipitate the N-ethyl, N'-allyl-urea. The nitrogen content was 21.3% (21.5% theoretical).
A 500 ml. flask equipped with a thermometer, condenser, and agitator was charged with 75 g. of the above urea, 91.1 g. of 43% aqueous glyoxal, and 87.5 g. distilled water. After complete dissolution of the reactants, the pH was adjusted to 7.0-7.5 with 25% sodium hydroxide and the mixture heated at 80°-85° C. for 4.5 hr. The glyoxal content was monitored during the reaction period. At the end of the heating period, no glyoxal was detected, indicating 100% reaction. The mixture was diluted with water and purified as before. The active solid content was 26.5% EADHEU.
Carbon-13 NMR analysis of the aqueous solution confirmed the presence of the imidazolidinone ring structure. The chemical shifts were as follows:
______________________________________Oc ppm Pattern Assignment______________________________________12.9 Quartet ##STR13##35.3 Triplet ##STR14##42.5 Triplet ##STR15##84.3 Doublet ##STR16##117.0 Triplet ##STR17##132.8 Doublet ##STR18##158.8 Singlet .sub.--CO______________________________________
EXAMPLE III
This example illustrates the preparation of additional imidazolidinone monomers using the procedure of Example II.
Part A
3-Allyl-4,5-dihydroxy-b 2-imidazolidinone (ADHEU) was prepared using 93.5 g. N-allyl urea, 109 g. 43% aqueous glyoxal, and 60 g. distilled water. The reaction was carried out for 6 hr. at 45°-50° C. Yield was 87%. The reactive solid content was 43.6%. The monomer had the following structure: ##STR19##
Part B
1-Methyl-3-(methacryloxyethyl)-4,5-dihydroxy-2-imidazolidinone was prepared using 37.2 g. N-methyl-N'-methacryloxyethyl urea, 25.7 g. 43% aqueous glyoxal, and 6 g. water. The reaction was carried out for 6.5 hr. at 60° C. Yield was 94%. The mixture was diluted with 124 g. distilled water. The active solids content was 25%. The monomer had the following structure: ##STR20##
Part C
1-Butyl-3-(2-methyl-1-propenyl)-4,5-dihydroxy-2-imidazolidinone was prepared using 85 g. N-butyl-N'-(2-methyl-1-propenyl)urea, 36.3 g. 80% aqueous glyoxal, and 106 g. water. The reaction was carried out for 8 hr. at 80° C. Yield was 100%. The mixture was diluted with 58 g. distilled water. The active solids content was 39.5%. The monomer had the following structure: ##STR21##
EXAMPLE IV
This example describes the preparation of 3-(β-hydroxyethyl-2-maleoxyethyl)-4,5-dihydroxy-2-imidazolidinone (EMDHEU). The three-step reaction sequence was as follows: ##STR22##
A two-liter round bottom flask, fitted with an agitator, thermometer, condenser, and drying tube, was charged with 1000 ml. of sieve dried toluene, 208 g. (2.0 moles) of β-hydroxyethyl urea and 196 g. (2.0 moles) of maleic anhydride. The reaction mixture was heated to 85°-90° C. Initially the mixture formed two distinct immiscible liquid phases. As the reaction proceeded, the mixture became homogeneous. Heating was continued until infrared analysis showed complete disappearance of the anhydride bands and the acid number of the reaction mixture indicated complete reaction (280 mg. KOH/gm. sample actual vs. 277 theory). The toluene was removed by vacuum stripping. A total of 393.5 g. of (97.5% yield) of N-(2-maleoxyethyl)urea was obtained.
While maintaining the above reaction mixture at 80°-85° C., 0.9 g. Na 2 CO 3 was added and the subsurface addition of ethylene oxide (115 g.) was carried out over 6 hours. At the end of the ethylene oxide addition, the acid number was 28 corresponding to a reaction efficiency of 91%. The residual ethylene oxide was removed by a brief vacuum stripping at 80° C. A total of 464 g. of N-(β-hydroxyethyl-2-maleoxyethyl)urea having an acid number of 15 (corresponding to 95% reaction) was obtained.
The above reaction mixture was cooled to 30° C. and 100 g. distilled water and 254 g. of 43% aqueous glyoxal were added. It was adjusted to pH 7.0-7.5 with 25% W/V sodium hydroxide and heated at 60° C. for 2 hr. After this time, no glyoxal was detected in the reaction mixture. It was diluted to 20% solids with 1917 g. water, treated with charcoal and filtered. Yield was 100%.
EXAMPLE V
This example describes the preparation of 3-(methacryloxy-2-hydroxypropoxyethyl)-4,5-dihydroxy-2-imidazolidinone (MPEDHEU). The two-step reaction sequence was as follows: ##STR23##
A 500 ml. round bottom reaction flask fitted with a thermometer, condenser and agitator was charged with 142 g. (1 mole) of glycidyl methacrylate, 0.25 g. monomethyl ether of hydroquinone, 0.75 g. tetramethyl ammonium chloride and 104 g. β-hydroxyethyl urea (1.0 mole). The mixture was heated and stirred at 80°-85° C. until gas-liquid chromatographic (GLC) analysis indicated complete consumption of the glycidyl methacrylate (about 6 hrs.). This is always indicated by testing the water solubility of the reaction mixture. The product is water soluble and near completion of the reaction no turbidity is observed in test samples. The reaction mixture was then cooled to 30° C. and 132 g. of water were added.
A portion of the above reaction mixture containing 154 g. of N(methacryloxy-2-hydroxypropoxyethyl)urea (0.407 moles) was charged to a 250 ml. reaction vessel equipped with a stirrer, thermometer, and condenser. To this was added 27.7 g. of glyoxal trimer (0.397 mole83% active) and 7.5 g. distilled water. The pH of the mixture was adjusted to 7.0-7.5 with 25% W/V NaOH and the mixture was heated at 65° C. for 3 hr. The glyoxal content was 0% indicating 100% reaction. The reaction mixture was treated with 4 gms. of activated carbon and filtered. The active solids content was 40%.
EXAMPLE VI
This example describes the preparation of 3-(1-propenoxy-2-hydroxypropoxyethyl)-4,5-dihydroxy-2-imidazolidinone.
The reaction was carried out in a similar manner to that of Example V except that 114 g. allylglycidyl ether (1 mole) was used in place of the glycidyl methacrylate and 135 g. (1 mole) of 43% aqueous glyoxal was used instead of the 83% aqueous glyoxal trimer. The active solids content was 45%. The monomer had the following structure: ##STR24##
EXAMPLE VII
This example describes the preparation of 3-allyl-4,5-dimethoxy-2-imidazolidinone.
A mixture of 100 g. of N-allyl urea (1 mole), 69.9 g. of 83% glyoxal (1 mole), and 750 g. methanol is stirred for 1 hr. at 35°-40° C. A total of 50 g. of a cation exchange resin (sulfonated polystyrene, H + form, 5.2 meq./dry g.) is then added. The mixture is stirred for 1 hr. at reflux (about 70° C.). The catalyst is removed by filtration, and the reaction mixture is concentrated by vacuum distillation of the solvent. The resulting product should be 232 g. of a syrup at 80% active solids (based on 100% yield). The monomer will have the following structure: ##STR25##
EXAMPLE VIII
This example describes the preparation of 1-ethyl-3-vinyl-4,5-dihydroxy-2-imidazolidinone.
A total of 172 g. of N-vinyl-N'-ethyl urea (1 mole), prepared as described in J. Poly. Science, Part A-1, Vol. 7, 35-46 (1969), is dissolved with stirring in 200 g. distilled water. To this solution is added 69.9 g. 83% glyoxal (1 mole). The pH of the mixture is adjusted to 7.5 with 0.5N NaOH, and the mixture is heated at 70° C. for 4.5 hr. or until a determination of the glyoxal content indicates complete conversion. The mixture is diluted with 133 g. distilled water and 0.23 g. monomethyl ether of hydroquinone. The diluted mixture is treated with 2 g. activated charcoal and filtered. The final product should be aqueous solution of the monomer at 80% solids (based on 100% yield). The monomer will have the following structure: ##STR26##
EXAMPLE IX
This example describes the preparation of a surfactant-stabilized latex polymer containing 58.9% vinyl acetate, and 35.3% butyl acrylate, 5.8% of the MEDHEU monomer of Example I. It also describes its evaluation after crosslinking and its use as a binder for non-woven textiles.
Part A
A two-liter four neck flask was fitted with a thermometer, condenser, agitator, subsurface nitrogen purge, and suitable addition funnels. To the flask was added:
400 g. distilled water
2.0 g. 20% sodium dodecyl benzene sulfonate
2.5 g. 70% ethoxylated nonyl phenol (30 moles EO)
0.5 g. sodium acetate
0.8 g. sodium persulfate
The mixture was purged subsurface with nitrogen at a rapid rate for 15 min. The gas rate was then reduced, and 50 g. vinyl acetate and 5 g. butyl acrylate were added. Agitation was started.
A monomer pre-emulsion was prepared by combining the following ingredients in a beaker and subjecting the mixture to high speed mixing: 125 g. of the MEDHEU monomer at 20%; 10 g. of 30 mole ethoxylated nonyl phenol at 70%; 12 g. of 20% sodium dodecyl benzene sulfonate; 200 g. vinyl acetate; 145 g. butyl acrylate. The mixture was transferred to a one-liter dropping funnel. A catalyst solution, designated S-2, was prepared by dissolving 0.7 g. sodium persulfate in 30 g. distilled water.
The initial reactor charge was heated to 72°-75° C. The mixture began to reflux at 72° C. Polymerization was indicated by a change in the mixture's appearance. After the refluxing stopped, the monomer pre-emulsion (S-1) and the catalyst solution (S-2) were slowly added to the reactor over a 4 hr. period at 72°-75° C. After the addition was complete, the batch was held for 1 hr. at 75° C., cooled, and discharged.
The resulting latex had a solids content of 48%. Yield was 98%. The properties of the latex were as follows: a pH of 4.1; intrinisic viscosity of 0.90 dl./g. in dimethyl formamide (DMF); Brookfield viscosity of 175 cps.; particle size of 0.17 nm.; and unfiltered grit (200 mesh) of 40 ppm. No formaldehyde was detected (the detectable limit was 5 ppm).
Part B
In order to evaluate the self-crosslinking capabilities and formaldehyde content of the above latex polymer, films were drawn on polyethylene as uncatalyzed or catalyzed (0.5% oxalic acid on polymer solids) latices. The films were air dried overnight or cured by heating in a forced air draft oven at 130° C. for 5 min. The film specimens were then weighed into enough DMF to make a 1% solution and refluxed for 2 hours. The cooled mixture was filtered, and the amount of soluble polymer was determined by oven solids. A determination of % insolubles was then made. A comparison polymer containing 3% N-methylolacrylamide (NMA), a known self-crosslinking monomer, was also evaluated.
______________________________________ Invention Latex Comparison Latex (containing (containing NMA) MEDHEU)______________________________________Formaldehyde on latex 3400 ppm NoneInsolubles - air dried 38% 45%Insolubles - catalyzed and 64% 70%air driedInsolubles - catalyzed and 89% 90%oven cured______________________________________
The results show the latex containing the self-crosslinking imidazolidinone-containing polymer of the present invention contained no formaldehyde and that it crosslinked as efficiently as the comparison latex containing the self-crosslinking polymer of the prior art.
Part C
The above latex polymers were evaluated as binders for non-woven textiles.
A substrate web of 100% polyester fiber was prepared by carding and subsequently lightly thermally bonded. The latex containing the MEDHEU polymer was formulated with 1% (dry basis) zinc chloride catalyst. The comparison latex containing the NMA polymer was formulated with 0.5% oxalic acid. The binders were diluted with water to 15% solids. The web was passed through a bath saturated with the binder formulation and squeezed through nip rolls to remove excess binder. Binder add-on was controlled to 40%±4% dry binder, based on fiber weight. This range was equivalent to 26-31% binder on total fabric weight and provided a finished fabric weighing approximately 20 gms./sq.yd. The saturated web was dried on a rotary drum dryer at 120° C. and then cured for 2 min. at 150° C. in a forced air oven. Specimens were tested for wet strength (soaked 5 min. in a 0.5% Aerosol OT solution) and dry strength in the cross machine direction (CD).
______________________________________Fabric Treatment Strength % Basis (lbs./linear inch)Latex Pickup Wt. CD Wet CD Dry______________________________________MEDHEU Polymer Latex 44 20.1 1.18 1.94NMA Polymer Latex 40 20.8 1.27 1.83(comparative)______________________________________
The results show that the formaldehyde-free binder containing the self-crosslinking imidozolidinone-containing polymer provided a non-woven textile of comparable wet and dry strength to that prepared using the prior art NMA-containing polymer that self-crosslinks with the release of formaldehyde.
EXAMPLE X
This example describes the preparation of a latex polymer of 82% vinyl acetate, 15% ethylene, and 5% of the EMDHEU monomer of Example IV.
A 1-liter stirred autoclave was charged with 213.5 g. distilled water, 0.011 g. FeSO 4 , 0.1% in water, 0.057 g. of a 75% solution of sodium dioctyl sulfosuccinate, 1.44 g. of a 80% solution of sodium dihexyl sulfosuccinate, 0.18 g. sodium acetate, and 2.28 g. acetic acid. The reactor was purged and evacuated with nitrogen three times. After purging, 35 g. vinyl acetate was loaded into the reactor. It was pressurized to 500 psi with ethylene and agitation was started.
A monomer pre-emulsion, designated S-1, was prepared by mixing with high speed agitation 85 g. distilled water, 0.5 g. calcium acetate, 5.0 g. partially ethoxylated phosphoric acid, 5.0 g. ethoxylated nonylphenol (40 moles EO), 50.0 g. MPEDHEU monomer at 20% solids, and 245.0 g.vinyl acetate.
Catalyst solutions, designated S-2 and S-3 respectively, were prepared by mixing 1.31 g. sodium persulfate and 17.5 g. distilled water and by mixing 0.52 g. sodium formaldehyde sulfoxylate and 17.5 g. distilled water.
The reactor contents were heated to 40° C. under 500 psi ethylene pressure. At temperature, the monomer pre-emulsion S-1, the oxidant S-2 and the reductant S-3 were added over a 6 hr. period. The reaction temperature was allowed to rise to 70° C. and was maintained at that temperature during the entire polymerization. At the end of the addition, the pressure source was isolated and the reactor pressure was allowed to drop over 2 hr. while maintaining the mixture at 70° C. The reactor was then cooled and the resultant latex discharged.
The latex was 41.1% solids. Conversion was 99%. The latex had the following properties: a pH of 4.2; intrinsic viscosity of 2.44 dl./g. in DMF; Brookfield viscosity of 25 cps.; particle size of 0.19 mm; and grit (200 mesh) of 20 ppm unfiltered. The Tg of the polymer was 30 3° C.
EXAMPLE XI
Using procedures outlined in Examples IX and X, latex polymers of 48.5% vinyl acetate, 48.5% butyl acrylate, and 3% of the indicated imidazolidinones were prepared. All values are based on 100 parts of the major monomer component and are expressed as active ingredient.
The initial charge was prepared by mixing 76.6 parts distilled water, 0.155 parts of a 31% solution of disodium ethoxylated alcohol half ester of sulfosuccinic acid, 0.42 part of a 70% solution of ethoxylated octyl phenol (30 mole EO), 10 parts vinyl acetate, 1 part butyl acrylate, 0.12 part ammonium persulfate, and 0.04 parts sodium acetate.
The monomer pre-emulsion was prepared from 15.7 parts distilled water, 40 parts vinyl acetate, 49 parts butyl acrylate, 3 parts of the imidazolidinone monomer described hereafter, 0.62 part disodium ethoxylated half ester of sulfosuccinic acid, and 0.7 part of a 70% solution of ethoxylated octyl phenol (30 mole EO). The catalyst used was prepared from 8 parts distilled water and 0.16 part ammonium persulfate.
Latex A prepared using the EADHEU monomer of Example II had a solids content of 48.3%. Conversion was 98%. It had a pH of 3.9; intrinsic viscosity of 1.524 dl./g. in DMF; viscosity of 30 cps.; particle size of 0.25 mm.; and grit (200 mesh) of 60 ppm. unfiltered. The % insolubles uncured (air-dried) and cured were 45 and 90%, respectively.
Latex B prepared using the EMDHEU monomer of Example IV had a solids content of 48.2%. Conversion was 98%. It had a pH of 4.2; intrinsic viscosity of 1.19 dl./g. in DMF; Brookfield viscosity of 77 cps.; particle size of 0.15 mm.; and grit (200 mesh) of 30 ppm. unfiltered. The % insolubles uncured and cured were 11 and 75%, respectively.
EXAMPLE XII
This example describes the preparation of a latex polymer of 87.4% ethyl acrylate, 9.7% methyl methacrylate, and 2.9% of the ADHEU monomer of EXAMPLE III--Part A. The polymerization procedure previously described was used.
The initial charge was prepared from 71.0 parts distilled water, 0.20 part sodium dodecylbenzene sulfonate, 0.40 part of ethoxylated octyl phenol (30 mole EO), 10 parts ethyl acrylate, and 0.15 part ammonium persulfate. The monomer pre-emulsion was prepared from 13.1 parts distilled water, 80.0 parts ethyl acrylate, 10.0 parts methyl methacrylate, 0.6 part sodium dodecylbenzene sulfonate, and 1.55 parts of ethoxylated octyl phenol (30 mole EO). The self-crosslinking functional monomer solution consisted of 3 parts of the ADHEU monomer and 12.2 parts water. The catalyst solution contained 10 parts water, 0.2 part ammonium persulfate, and 0.1 part sodium bicarbonate.
The resulting latex had a solids content of 47.7%; a pH of 3.2; intrinsic viscosity of 0.603 dl./g. in DMF; Brookfield viscosity of 400 cps.; particle size of 0.17 mm.; and grit (200 mesh) of 10 ppm. The conversion was 95.8%.
EXAMPLE XIII
This example describes the prepration of a polyvinyl alcohol-stabilized latex polymer of about 97.1% vinyl acetate and 2.9% of the MEDHEU monomer of Example I.
A 2-liter reactor was charged with an initial mixture of 288 parts distilled water, 6 parts medium viscosity 88% polyvinyl alcohol, 9 parts high viscosity 88% polyvinyl alcohol, 0.46 parts ammonium persulfate, and 50 parts vinyl acetate. The mixture was heated to reflux (about 72° C.). To the heated mixture were slowly added a pre-emulsion of 90.9 parts distilled water, 0.2 parts medium viscosity 88% polyvinyl alcohol, 75.0 parts of the MEDHEU monomer (20%), 0.45 parts hih viscosity 88% polyvinyl alcohol, and 45 parts vinyl acetate and a catalyst solution of 26.5 parts distilled water, 0.75 parts 28% ammonium hydroxide solution, and 0.25 parts ammonium persulfate. The pre-emulsion and catalyst solution were added at a rate sufficient to maintain reflux (over about 3 hr.). After the addition was completed, the batch was cooled and discharged. The resulting latex had a solids content of 52.3%, a pH of 4.6, and Brookfield viscosity of 7000 cps.
Now that the preferred embodiments of the invention have been described in detail, various modifications and improvements thereon will become readily apparent to those skilled in the art. Accordingly, the spirit and scope of the present invention are to be limited only by the appended claims, and not by the foregoing specification.
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Novel polymerizable imidazolidinone monomers, useful in the preparation of self-crosslinking polymers, have the general structure ##STR1## wherein R 1 is H or a C 1 -C 6 linear or branched alkyl or hydroxyalkyl group; X is a divalent radical selected from the group consisting of ##STR2## with R being H or CH 3 , m being 0-5, and n being 1-5; R 2 is H or CH 3 ; R 3 is H or ##STR3## with R' as defined above; and R 4 and R 5 are independently H or linear or branched C 1 -C 4 alkyl groups. In a preferred embodiment, aqueous emulsions of the imidazolidinone-containing polymers (e.g. 45-60% vinyl acetate, 34-52% butyl acrylate, and 3-6% imidazolidinone) and an acid-curing catalyst (e.g. ZnCl 2 ) are used as formaldehyde-free binders for nonwoven textiles.
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CROSS REFERENCE TO RELATED APPLICATIONS
This Application claims priority of Taiwan Patent Application No.100207618, filed on Apr. 29, 2011, the entirety of which is incorporated by reference herein.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to detecting an output voltage of an LED driving device and more particularly to detecting an output voltage of a driving device that uses a constant current source to drive an LED.
2. Description of the Related Art
Ways to drive a light-emitting diode (LED) can be classified into three types: a constant voltage source type, a constant current source type and a pulse type. Advantages of the constant voltage source type driver are low costs and uncomplicated external circuitry; but, a disadvantage is luminance inconsistency of LEDs. Generally, the constant current source type driver can overcome the problem of luminance inconsistency of LEDs. For driving of the constant current source type driver, LEDs are connected in serial so as to assure the LEDs of luminance consistency. In addition, the constant current source type driver can avoid the condition where the reliability of the driving is influenced by the driving current when the driving current exceeds a largest rated value.
When an LED fails, the output voltage of the LED driving device is different from a normal operating voltage. Therefore, a voltage detecting device for detecting whether the output voltage of the LED driving device is normal or not is needed. Particularly, when the power of a system has to be lowered due to heat dissipating concerns, the voltage of power source is lowered. In the case, if the output voltage of the LED driving device is lower than a normal operating range, the output current may be abnormal, and the abnormal output current has to be detected.
FIG. 1 is a schematic diagram of an LED device showing a known way to detect an output voltage of a driving circuitry. The LEDs LED 1-N are connected in serial and are coupled to an LED driving circuitry. The LED driving circuitry comprises a driving device 108 and a comparator CP 1 . In this way, an output terminal a of the driving device 108 of the LED driving circuitry is directly coupled to a negative terminal of the comparator CP 1 , so that the voltage of the output terminal a can be compared with a reference voltage VREF coupled to a positive terminal of the comparator CP 1 . When the voltage of the output terminal a is lower than the reference voltage VREF, a detecting signal Flag 1 output by the comparator CP 1 is at a high voltage level. The condition where the detecting signal Flag 1 is at a high voltage level means that the voltage of the output terminal a of the driving device is too low and that the output current lout may be abnormal.
In order to connect a plurality of LEDs in serial, a voltage VLED is usually much higher than voltage VDD. Therefore, when a pulse-width modulator PWM controls a switch Si to be off, the comparator CP 1 has to be able to receive a high-voltage-level voltage. However, the area of the circuitry of the comparator CP 1 is larger when using high voltage elements to realize the comparator CP 1 . Furthermore, an input offset voltage is higher. Therefore, the detecting way as shown in FIG. 1 is not accurate when detecting the voltage of the output terminal a of the driving device.
FIG. 2 is a schematic diagram of an LED device showing another known way to detect an output voltage of a driving circuitry. In this case, in order to use low voltage elements to realize the comparator CP 2 , the resistances R 1 and R 2 are used to divide voltage so as to divide the voltage of an output terminal b of a driving device 208 by (VLED/VSS). Accordingly, when the pulse-width modulator PWM controls a switch S 2 to be off, voltage of a terminal c connected to a negative terminal of the comparator CP 2 is ensured to be lower than or equal to the voltage VDD.
In the way shown in FIG. 2 , though low voltage elements can be used to realize the comparator CP 2 and thus the input offset voltage is smaller, the influence caused by the input offset is enlarged by (VLED/VSS) times. The greater the amount of LEDs, the higher the voltage VLED is, and thus the bigger the influence caused by the input offset is. In addition, there is also an error caused by mismatch of the resistances R 1 and R 2 in the way shown in FIG. 2 .
BRIEF SUMMARY OF THE INVENTION
In view of this, the invention provides a voltage detecting device, applied to a driving device of a light-emitting diode device. The voltage detecting device uses a comparing device realized by low voltage elements to detect an output voltage of the driving device, so that a detecting error enlarged by voltage division of resistances is hindered.
The voltage detecting device comprises: a voltage inspecting device, coupled to an output terminal of the driving device to inspect a status of an output voltage of the driving device and outputting an inspecting signal; an isolating/connecting control device, coupled between the voltage inspecting device and the driving device, isolating or connecting the output terminal of the driving device according to the inspecting signal; and a comparing device, coupled to the isolating/connecting control device, comparing the output voltage of the driving device with a reference voltage and generating a detecting signal according to the comparing result. The comparing device is composed of low voltage elements.
Another embodiment of the invention provides a driving circuitry for light-emitting diode (LED) devices, comprising: a driving device, coupled to an LED device to drive the LED device; a voltage inspecting device, coupled to an output terminal of the driving device to inspect a status of an output voltage of the driving device and outputting an inspecting signal; an isolating/connecting control device, coupled between the voltage inspecting device and the driving device, isolating or connecting the output terminal of the driving device according to the inspecting signal; and a comparing device, coupled to the isolating/connecting control device, comparing the output voltage of the driving device with a reference voltage and generating a detecting signal according to the comparing result. The comparing device is composed of low voltage elements.
A detailed description is given in the following embodiments with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein:
FIG. 1 is a schematic diagram of an LED device showing a known way to detect an output voltage of a driving circuitry;
FIG. 2 is a schematic diagram of an LED device showing another known way to detect an output voltage of a driving circuitry;
FIG. 3 shows a block diagram of a voltage detecting device applied to an LED driving device according to an embodiment of the invention;
FIG. 4 shows a circuitry of a voltage detecting device applied to an LED driving device according to an embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
The following description is of the best-contemplated mode of carrying out the invention. This description is made for the purpose of illustrating the general principles of the invention and should not be taken in a limiting sense. The scope of the invention is best determined by reference to the appended claims.
As shown in FIG. 3 , according to an embodiment of the invention, the voltage detecting device 300 comprises a voltage inspecting device 302 coupled to an output terminal of a driving device 308 , a comparing device 306 composed of low voltage elements and an isolating/connecting control device 304 coupled between the output terminal of the driving device 308 and the comparing device 306 . The voltage inspecting device 302 receives the voltage of the output terminal of the driving device 308 and outputs an inspecting signal. If the voltage of the output terminal of the driving device 308 is at a high voltage level, the inspecting signal is a second signal SW . If the voltage of the output terminal of the driving device 308 is at a low voltage level, the inspecting signal is a first signal SW. The comparing device 306 compares the voltage of the output terminal of the driving device 308 with a reference voltage VREF and outputs a detecting signal Flag 3 to determine whether the voltage of the output terminal of the driving device 308 is normal or not. The isolating/connecting control device 304 electrically isolates the comparing device 306 from the voltage of the output terminal of the driving device 308 or electrically connects the comparing device 306 with the voltage of the output terminal of the driving device 308 according to the inspecting signal output by the voltage inspecting device 302 . If the inspecting signal is the second signal SW , the isolating/connecting control device 304 electrically isolates the comparing device 306 from the voltage of the output terminal of the driving device 308 to prevent the comparing device 306 from being damaged by the high-voltage-level voltage of the output terminal. If the inspecting signal is the first signal SW, the isolating/connecting control device 304 electrically connects the comparing device 306 with the voltage of the output terminal of the driving device 308 to make the comparing device 306 compare the voltage of the output terminal with the reference voltage so as to determine whether the voltage of the output terminal is normal or not. When the voltage of the output terminal of the driving device 308 is at a high voltage level, since the isolating/connecting control device 304 electrically isolates the comparing device 306 from the voltage of the output terminal of the driving device 308 , the comparing device 306 can be realized by low voltage elements. In one embodiment of the invention, the driving device 308 and the voltage detecting device 300 are packaged together or manufactured in the same integrated circuit.
Referring FIG. 4 , a driving device 408 of the LED device LED 1-N comprises a switch S 1 controlled by a pulse-width modulator and a constant current source lout. The pulse-width modulator (not shown in the Fig.) transmits a PWN control signal to control the switch S 1 to be on or off. When the switch S 1 is on, the constant current source lout drives the LED device LED 1-N .
As shown in FIG. 4 , in a voltage detecting device 400 , a voltage inspecting device 402 comprises a diode D 1 and transistors M 1 and M 2 . A cathode of the diode D 1 is coupled to an output terminal k of the driving device 408 . Sources of the transistors M 1 and M 2 are connected to a power supply source VDD. Gates of the transistors M 1 and M 2 are connected together. A drain of the transistor M 1 is coupled to the gate of the transistor M 1 and is further coupled to an anode of the diode D 1 through a resistance R 5 . A drain of the transistor M 2 is grounded through a resistance R 6 . The drain of the transistor M 2 is further coupled to an inspecting signal of the voltage inspecting device 402 . An isolating/connecting control device 404 comprises an isolating diode D 2 and a controllable current source I 1 and a controllable current source I 2 . A cathode of the isolating diode D 2 is coupled to a negative input terminal of a comparator CP 3 of a comparing device 406 . The voltage detecting device 400 further comprises a compensating diode D 3 and a controllable current source I 3 . An anode of the compensating diode D 3 is coupled to the controllable current source I 3 and a positive input terminal of the comparator CP 3 of the comparing device 406 . A cathode of the compensating diode D 3 is coupled to the reference voltage VREF. The compensating diode D 3 matches the isolating diode D 2 . The output current of the controllable current source I 3 is equal to the output current of the controllable current source I 1 .
When the switch S 1 of the driving device 408 is off, the LED device LED 1-N is not driven, and the voltage of the output terminal k of the driving device 408 is pulled up to the voltage VLED. Therefore, the diode D 1 is off. Because the diode D 1 is off, the voltage of the drain terminal h of the transistor M 2 is pulled down. At the same time, the voltage inspecting device 402 outputs the inspecting signal SW . The inspecting signal SW makes the controllable current source I 2 to be on and the controllable current source I 1 to be off. Since the controllable current source I 2 is on, the voltage of the anode of the isolating diode D 2 is pulled down to be grounded by the turned-on controllable current source I 2 , and thus the isolating diode D 2 is off. At the time, the output terminal k of the driving device 408 is isolated from the comparing device 406 by the turned-off isolating diode D 2 . Therefore, the comparing device 406 is not damaged by the high-voltage-level voltage of the output terminal k of the driving device 408 . Accordingly, the comparing device 406 can be realized by low voltage elements.
When the switch S 1 of the driving device 408 is on, the LED device LED 1-N is driven, and the voltage of the output terminal k of the driving device 408 is pulled down. Therefore, the diode D 1 is on. Because the diode D 1 is on, the voltage of the drain terminal h of the transistor M 2 is pulled up. At the same time, the voltage inspecting device 402 outputs the inspecting signal SW. The inspecting signal SW makes the controllable current source I 1 to be on and the controllable current source I 2 to be off. Since the controllable current source I 1 is on, the voltage of the negative input terminal of the comparator CP 3 is equal to a sum of the voltage of the output terminal k of the driving device 408 and the voltage of the turned-on isolating diode D 2 . At the same time, the inspecting signal SW controls the controllable current source I 3 to make the controllable current source I 3 to be on. Therefore, the voltage of the positive input terminal of the comparator CP 3 is equal to a sum of the reference voltage VREF and the voltage of the turned-on compensating diode D 3 . Since the compensating diode D 3 matches the isolating diode D 2 and the output current of the controllable current source I 3 is equal to the output current of the controllable current source I 1 , the voltage of the turned-on isolating diode D 2 is equal to the voltage of the turned-on compensating diode D 3 . Therefore, the comparator CP 3 can compare the voltage of the output terminal k of the driving device 408 with the reference voltage VREF. When the voltage of the output terminal k of the driving device 408 is lower than the reference voltage VREF, the detecting signal Flag 3 output by the comparator CP 3 is at a high voltage level. In this case, the voltage of the output terminal k of the driving device 408 being too low is detected and the output current Iout may be abnormal.
In one embodiment of the invention, the driving device 408 and the voltage detecting device 400 are packaged together or manufactured in the same integrated circuit.
While the invention has been described by way of example and in terms of preferred embodiment, it is to be understood that the invention is not limited thereto. To the contrary, it is intended to cover various modifications and similar arrangements (as would be apparent to those skilled in the art). Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.
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A voltage detecting device applied to a driving device of a light-emitting diode device is provided. The detecting device includes a voltage inspecting device, an isolating/connecting control device and a comparing device. The voltage inspecting device is coupled to an output terminal of the driving device to inspect a status of an output voltage of the driving device and outputs an inspecting signal. The isolating/connecting control device, coupled between the voltage inspecting device and the driving device, isolates or connects the output terminal of the driving device according to the inspecting signal. The comparing device, composed of low voltage elements, is coupled to the isolating/connecting control device, and compares the output voltage of the driving device with a reference voltage and generates a detecting signal according to the comparing result.
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This application is a continuation of application Ser. No. 08/339,266, filed Nov. 10, 1994, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a video system suitable for use in a teleconference or the like using an image through a multimedia network.
2. Related Background Art
In recent years, a television conferencing system has been widespread due to a spread of high speed digital lines. As a typical construction of the conventional television conferencing system, there is a representative system such that exclusive-use terminals each comprising a video camera for displaying the face of a speaker and a video monitor are installed at two or more locations and the terminals are connected by lines of N-ISDN or the like.
However, even if an exclusive-use video monitor is not used, moving images can be displayed on multiwindows owing to the recent realization of a high performance of a personal computer or a workstation. Therefore, a teleconference using moving images and voice sounds (hereinafter, the conference of such a style is referred to as a multimedia teleconference) is being put into practical use by using personal computers and workstations which are connected by a network. A calligraphic and pictorial camera to photograph not only the face of a partner of the conference but also a document or solid object is also used.
Moving images and voice sounds are used in the teleconference because of the introduction of the multimedia teleconferencing system, so that a communication of a higher quality is realized. However, in order to see a portion or the like which is not displayed on a display apparatus on the operator side, a message indicating that the operator wants to see such a hidden portion is informed to the partner side each time so as to operate the camera on the partner side. There is consequently a problem such that both operations are troublesome and the conference is interrupted or the like.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a video system with a high use efficiency and a high performance.
Another object of the invention is to provide an image pickup control apparatus which can photograph a video image with a high picture quality.
Still another object of the invention is to provide a camera corresponding to a video system of a high performance.
To accomplish the above objects, according to an embodiment of the present invention, control means for controlling a camera is connected to the camera by communicating means, an image pickup state of the camera is set on a screen of display means for displaying a video signal which is generated from the camera, and the camera is controlled so as to photograph an object in the set image pickup state. By using the above construction, there is an effect such that the image pickup state of the camera existing at a remote position can be easily controlled.
According to another embodiment of the invention, control means for controlling a camera is connected to the camera by communicating means, an image pickup state of the camera is set on a screen of display means for displaying a video signal which is generated from the camera, and the set image pickup state is stored. By using the above construction, there is an effect such that the image pickup state of the camera existing at a remote position can be quickly changed as necessary.
According to another embodiment of the invention, control means for controlling a camera is connected to the camera by communicating means, a range on a screen of display means for displaying a video signal which is generated from the camera is designated, and an image pickup state of the camera is changed for the designated range. By using the above construction, there is an effect such that the image pickup state of the camera existing at a remote position can be changed for a necessary range on the screen and a video image of a higher picture quality can be obtained.
According to another embodiment of the invention, when image pickup means of a camera converts an optical image into a video signal, its image pickup state is changed in accordance with an input from an external apparatus. By using the above construction, there is an effect such that the image pickup state of the camera can be controlled from a remote position.
According to further another embodiment of the invention, an apparatus has an image pickup element for converting a light to an electric signal, an image signal photographed by image pickup means which is controlled by an external input is displayed by image display means having a multiwindow display function through communicating means, a display screen of the display means is instructed and inputted by a pointing device, and a panning control of a desired image pickup apparatus is executed through communicating means. By using the above construction, there is an effect such that the panning control of the image pickup means existing at a remote position can be easily and certainly executed.
According to a further embodiment of the invention, an apparatus has an image pickup element for converting light to an image signal, an image signal obtained by photographing an object by image pickup means whose operation is controlled by an external input is displayed on image display means having a multiwindow display function through communicating means, a display surface of the display means is designated by a pointing device, and a focal distance and a direction of desired image pickup means are controlled through communicating means so that a field angle of the designated region coincides with a display image. By using the above construction, there is an effect such that the focal distance and direction of the image pickup means existing at a remote position can be easily and certainly controlled.
According to yet another embodiment of the invention, an apparatus has an image pickup element for converting light to an image signal, an image signal obtained by photographing an object by image pickup means whose operation is controlled by an external input is displayed by image display means having a multiwindow display function through communicating means, a display surface of the display means is designated by a pointing device, and an exposure amount of desired image pickup means is controlled through the communicating means so that a display image of the designated region has an optimum exposure amount. By using the above construction, there is an effect such that the exposure amount of the image pickup means existing at a remote position can be easily and certainly controlled.
According to yet another embodiment of the invention, an apparatus has an image pickup element for converting a light to an electric signal, an image signal obtained by photographing an object by image pickup means whose white balance is controlled by an external input is displayed by image display means having a multiwindow display function through communicating means, and a white balance of desired image pickup means is controlled through the communicating means so that the image is displayed in white. By using the above construction, there is an effect such that the white balance of the image pickup means existing at a remote position can be easily and certainly controlled.
According to a still further embodiment of the invention, an apparatus has an image pickup element for converting a light to an electric signal, an image signal obtained by photographing an object by image pickup means whose focus is automatically controlled by an external input is displayed through communicating means by image display means having a multiwindow display function, a display screen of the display means is designated by a pointing device, and a desired automatic focusing control is executed for the designated region through the communicating means. By using the above construction, there is an effect such that the automatic focusing control of the image pickup means existing at a remote position can be easily and certainly executed.
The above and other objects and features of the present invention will become apparent from the following detailed description and the appended claims with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram showing a whole construction of an embodiment of the present invention;
FIG. 2 is a block diagram showing a constructional example of a terminal station A and a camera A- 1 ;
FIG. 3 is a block diagram showing a processing flow of a signal processing circuit 110 ;
FIG. 4 is a block diagram showing a processing flow of a signal processing circuit 119 ;
FIG. 5 is an explanatory diagram of a display screen of a terminal station A:
FIG. 6 is an explanatory diagram of each section of a camera control menu 205 and a display window 201 ;
FIG. 7 is a diagram showing a part of a flow of a multimedia teleconference according to an embodiment;
FIGS. 8A to 8 E are diagrams for explaining a user interface of a panning control in the embodiment;
FIGS. 9A to 9 E are explanatory diagrams about a zooming control in the embodiment;
FIGS. 10A to 10 D are diagrams showing the user interface when an exposure level of an image of an arbitrary designated range is set to a proper value;
FIGS. 11A to 11 D are diagrams showing the user interface when a focus is positioned to an object of an arbitrary designated range in the embodiment;
FIGS. 12A to 12 D are diagrams showing the user interface when a white balance is attained on the basis of image information of an arbitrary designated range in the embodiment;
FIGS. 13A to 13 D are diagrams showing a memory function of a field angle setting and the user interface in the embodiment;
FIG. 14 is a diagram showing a display example when a memory function of the setting and a reduction image is applied to a hierarchy menu of an AE menu;
FIGS. 15A to 15 C are diagrams for explaining the user interface when the setting of a camera A- 2 is fixed for a predetermined time; and
FIG. 16 is a diagram showing a control flow to authorize to control a camera.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is a schematic diagram showing an example of a whole construction of the invention.
In FIG. 1, reference numeral 1 denotes a first terminal station which is used in a multimedia teleconference and it is simply called a terminal A. Actually, it is not always necessary to use the terminal only for the multimedia teleconference but a personal computer or a workstation which has a bit map display and can display in multiwindows is used as a terminal. Reference numeral 2 denotes a camera for mainly photographing the face of a person and such a camera is hereinafter referred to as a camera A- 1 . Reference numeral 3 denotes a tripod to control the direction of the camera A- 1 ; 4 indicates a calligraphic and pictorial camera for photographing an original, a printed matter, a solid object, or the like and such a camera is hereinafter referred to as a camera A- 2 ; 5 indicates a movable arm for changing a photographing region of the camera A- 2 .
In a manner similar to the above, reference numeral 6 denotes a second terminal station B; 7 a camera B- 1 connected to the terminal B; 8 a tripod of the camera B- 1 ; 9 a calligraphic and pictorial camera which is connected to the terminal B and such a camera is hereinafter referred to as a camera B- 2 ; 10 a movable arm of the camera B- 2 ; 11 a third terminal station C; 12 a camera which is connected to the terminal C and such a camera is hereinafter referred to as a camera C- 1 ; 13 a tripod of the camera C- 1 ; 14 a calligraphic and pictorial camera which is connected to the terminal C and such a camera is hereinafter referred to as a camera C- 2 ; and 15 a movable arm of the camera C- 2 .
The image pickup region of each camera is controlled from each terminal by the tripods 3 , 8 , and 13 and the movable arms 5 , 10 , and 15 . Reference numeral 16 denotes a network to connect the terminal stations and 17 indicates a server to manage the multimedia teleconferencing system. As for an image of each camera, one window is allocated to one camera and those images are displayed in multiwindows of the display of each terminal.
FIG. 2 is a block diagram showing a constructional example of the terminal A and the camera A- 1 . It is assumed that the other cameras also have a similar construction unless otherwise specified in the following description and the component elements having the same functions are designated by the same reference numerals.
In FIG. 2, reference numeral 101 denotes a lens; 102 a lens driving unit for performing a focusing adjustment of the lens and a zooming; 103 an iris; 104 an iris driving unit; 105 a solid-state image pickup element for converting an optical image projected by the lens 101 to an electric signal; 106 a solid-state image pickup element driving circuit for driving the solid-state image pickup element 105 ; 107 an A/D converter for A/D converting an output of the solid-state image pickup element 105 ; 108 a memory for temporarily storing the A/D converted image data; 109 an encoding circuit for compressing and encoding the image data which was temporarily stored in the memory 108 ; 110 a signal processing circuit for performing signal processes such as color separation, white balance correction, color conversion, frequency band limitation, outline correction, and the like of the image data stored temporarily in the memory 108 ; 111 a data bus to access the digital data in the memory 108 by the compressing circuit 109 and signal processing circuit 110 ; 112 a system control circuit for controlling the operation of the camera system; and 113 a tripod driving unit for driving the tripod 3 of the camera A- 1 . It is now assumed that in case of the calligraphic and pictorial camera like a camera A- 2 , the tripod driving unit 113 drives the movable arm 5 . Reference numeral 114 denotes an external interface circuit for transmitting digital image data from the camera A- 1 to the terminal A and for transmitting control parameters from the terminal A to the camera A- 1 . The camera A- 1 is constructed by the above component elements.
Reference numeral 115 denotes a first external interface circuit of the terminal A. The I/F circuit 115 is connected to the camera A- 1 . Reference numeral 116 denotes a second external interface circuit of the terminal A. The I/F circuit 116 is connected to the camera A- 2 . Reference numeral 117 denotes a memory to temporarily store digital image data from a network; 118 a decoding circuit for expanding and decoding the image data sent from the network and camera as data compressed and encoded data; 119 a signal processing circuit for performing processes such as color conversion and gradation correction to the image data which has been decoded and stored temporarily in the memory 117 ; and 120 a D/A converter for D/A converting the signal which was processed by the signal processing circuit 119 .
Reference numeral 121 denotes a data bus to access the digital data in the memory 117 ; 122 a system control circuit to control the operation of the terminal A; 123 a pointing device such as a mouse or the like; 127 a button of the pointing device 123 ; 124 a pointing device interface as an interface between the pointing device 123 and the system control circuit 122 ; 125 a network interface circuit for connecting the network and the terminal A; and 126 a monitor to display an image or data. The terminal A is constructed by the above component elements.
FIG. 3 is a block diagram showing a processing flow of the signal processing circuit 110 .
In FIG. 3, reference numeral 501 denotes a block of a color separation to extract signals corresponding to R, G, and B from an output of the solid-state image pickup element 105 ; 502 a block of a white balance to adjust a gain balance among the signal levels so that ratios of R, G, and B of a white portion of an object are set to 1:1:1; 503 a block of a color conversion to convert the RGB signals to a luminance and color difference signals of a good compressing efficiency; 504 a block of a frequency band limitation to limit unnecessary frequency bands; and 505 a block of an outline correction to improve a resolution feeling.
FIG. 4 is a block diagram showing a processing flow of the signal processing circuit 119 . Reference numeral 506 denotes a block of a color conversion to convert the luminance and color difference signals to the RGB signals; and 507 a gradation correction block to match with gradation characteristics of the monitor 126 .
The operation of the terminal A will now be described.
In FIG. 2, image data from another terminal which is transmitted from the network 16 and a control command and parameters of the camera are supplied to the system control circuit 122 through the network interface circuit 125 .
The image data from the network 16 and the image data from the camera A- 1 or A- 2 are stored into the memory 117 through the data bus 121 . If the control command and parameters of the camera relate to the control of the camera A- 1 , they are supplied to the camera A- 1 through the external interface circuit 115 . If they relate to the control of the camera A- 2 , they are sent to the camera A- 2 via the external interface circuit 116 . The image data stored in the memory 117 is expanded and decoded by the decoding circuit 118 and is processed by the signal processing circuit 119 . After that, the signal is D/A converted and the resultant analog signal is displayed on the monitor 126 .
The operation of the camera A- 1 will now be described.
The object is projected to the solid-state image pickup element 105 by the lens 101 . In this instance, the focusing adjustment and the field angle adjustment are controlled by the system control circuit 112 through the lens driving unit 102 . A light amount is controlled by the system control circuit 112 via the iris driving unit 104 . The direction of the camera A- 1 is controlled by the system control circuit 112 through the tripod driving unit 113 . An output of the solid-state image pickup element 105 is converted to digital data by the A/D converter 107 and is once stored into the memory 108 . The output data of the solid-state image pickup element 105 stored in the memory 108 is subjected to processes such as color separation, white balance, color conversion, frequency band limitation, and outline correction by the signal processing circuit 110 . The processed image data is compressed and encoded by the encoding circuit 109 and is transmitted to the terminal A through the external interface circuit 114 .
The image data sent to the terminal A is displayed on a window of the monitor 126 of the terminal A in a manner similar to that mentioned above and is also transmitted to the network 16 . The control command and parameters of the camera A- 1 are interpreted by the system control circuit 112 , thereby performing the focusing control, iris control, white balance, tripod control, and the like. Since the controllable items and the possible range of the parameters differ in dependence on each camera, the items which can be controlled by the camera, the possible range of the parameters, and the present values of the parameters are supplied from the system control circuit 112 to the terminal A in accordance with an inquiry from the terminal A. They are further supplied to the server 17 through the network 16 .
FIG. 5 is an explanatory diagram of a display screen of the terminal A.
In FIG. 5, reference numeral 201 denotes a display window of the camera A- 1 ; 202 a display window of the camera A- 2 ; 203 a display window of the camera B- 1 ; 204 a display window of the camera B- 2 ; and 205 a camera control menu.
FIG. 6 is an explanatory diagram of each section of the camera control menu 205 and display window 201 .
Reference numeral 301 denotes a cursor indicative of the position designated by the pointing device; 302 a vertical panning bar as a rectangular region to display a user interface for controlling a panning in the vertical direction of the camera; 303 an upward panning button which is used when panning upward; 304 a downward panning button which is used when panning downward; and 305 a region called a thumb which is designated by pressing the button 127 of the pointing device 123 . By vertically moving the cursor 301 , the vertical panning operation of the camera can be executed.
The operation to move the cursor 301 with the button 127 of the pointing device 123 depressed as mentioned above is generally called “drag” and this terminology will be used hereinbelow. The operation such that the button 127 of the pointing device 123 is pressed and is soon released is generally called “click” and this terminology will be used hereinbelow.
Reference numeral 306 denotes a horizontal panning bar as a rectangular region to display a user interface to control the horizontal panning of the camera; 307 a leftward panning button which is used when panning leftward; 308 a rightward panning button which is used when panning rightward; and 309 a thumb of the horizontal panning bar 306 .
Reference numeral 310 denotes a zoom bar as a rectangular region to display a user interface for controlling a field angle; 311 a telephoto button which is used when the camera is zoomed in; 316 a wide button which is used when the camera is zoomed out; and 313 a thumb of the zoom bar 310 .
Reference numeral 312 indicates a rectangular region which is used for display or the like of the name of the display window and is called a title bar; 315 a name of a display window and it is assumed in the embodiment that an identification name of the camera is displayed; and 314 a status display region of the camera.
Reference numeral 408 indicates a movement bar as a rectangular region which is used when moving the camera control menu 205 ; 401 a Lock menu; 402 an AE menu; 403 an AF menu; 404 an AWB menu; and 405 an Angle menu. Functions of the above menus will be described hereinbelow. Reference numeral 406 denotes a Configuration menu which is used to set other items and 407 indicates a hierarchy menu button which is displayed in the case where the functions which are further classified as a hierarchy exist in the lower layer. By clicking the hierarchy menu button 407 , the menu of the lower layer is displayed. The hierarchy menu button 407 is displayed in all of the menus having the hierarchy menu.
FIG. 7 is a diagram showing a part of a flow of the multimedia teleconference in the embodiment.
A server to manage the conferencing system first inquires the controllable items and parameters of each camera connected to each terminal, the possible range of the parameters, and the present values thereof (step S 1 ). Each camera receives the inquiry through the terminal and responds to the inquiry. If the camera does not have a responding ability, the terminal substitutionally responds. The server forms a table of the specification and initial status of the camera by the response information (S 2 to S 4 ). The display window 201 and camera control menu 205 are displayed on each terminal on the basis of the information of the table (S 5 ). In this instance, a user interface for controlling according to the specification of each camera is displayed in the display window of each camera.
In the example shown in FIG. 5, as a result of the inquiry to the camera B- 1 , it is found out that the functions of zoom and panning cannot be used.
Therefore, the vertical panning bar 302 , horizontal panning bar 306 , and zoom bar 310 are not displayed in the display window of the camera B- 1 . The aspect ratio of the camera is reflected to the shape of the display window. When the aspect ratio of the camera is equal to 4:3, the aspect ratio of the display window is equal to 4:3. When the aspect ratio of the camera is equal to 16:9, the aspect ratio of the display window is equal to 16:9. When the display window of the camera is displayed, the multimedia teleconference is started and the processing routine enters a loop to watch an event from each participant. If the participant does nothing, the watching of the event is continued (S 6 ).
In the case where an event such as selection or the like of a menu by the participant is detected, the event is analyzed (S 7 ). If the event indicates the item regarding the control of the camera, a control message is sent to the camera (S 8 , S 9 ). In case of the other item, the processing corresponding to it is executed (S 10 ). In case of a message such as to change a condition of the camera, the camera analyzes the message and changes in a possible range. After that, a new condition is informed as a message to the server. The server changes a camera condition table by the message of the camera and changes the state of the display window of each terminal and the camera control menu (S 11 ). The processing routine advances to an event loop to again perform the watching operation of the event.
The control operation and display for the camera image pickup operation will now be practically explained with reference to the description of the name of each section of the screen displays shown in FIGS. 5 and 6 and explanatory diagrams of the operations of FIG. 8 A and subsequent diagrams.
FIGS. 8A to 8 E are diagrams for explaining with respect to a user interface of the panning control in the embodiment. For example, FIGS. 8A to 8 E show a case of performing the panning of the camera A- 2 .
As shown in FIG. 8A, when the title bar 312 of the display window of the camera A- 2 is designated and clicked by the pointing device 123 , the camera A- 2 can be controlled. In this instance, the color of the title bar 312 changes as shown in FIG. 8B, thereby indicating that the camera A- 2 becomes controllable.
The positions of the thumbs 305 , 309 , and 313 in the panning bars 302 and 306 and zoom bar 310 are determined on the basis of a specification table and a status table of the camera A- 2 formed by the server 17 .
FIG. 8B shows a method of controlling the vertical panning of the camera A- 2 . When the downward panning button 304 of the vertical panning bar 302 of the camera A- 2 is designated and clicked or when the thumb 305 is designated and is dragged downward, the movable arm 5 of the camera A- 2 operates, thereby panning the camera A- 2 downward. In this instance, the panning operation is performed for a period of time during which the button 127 of the pointing device 123 is depressed. When the button is released, the panning operation is stopped.
On the contrary, when the upward panning button 303 of the vertical panning bar 302 is designated and is kept clicked or when the thumb 305 is designated and is dragged upward as shown in FIG. 8C, the movable arm 5 of the camera A- 2 operates, thereby panning the camera A- 2 upward.
When the rightward panning button 308 of the horizontal panning bar 306 is designated and clicked or when the thumb 309 is designated and dragged rightward as shown in FIG. 8D, the movable arm 5 of the camera A- 2 operates, thereby panning the camera A- 2 rightward. On the contrary, when the leftward panning button 307 of the horizontal panning bar 306 is designated and clicked or when the thumb 309 is designated and dragged leftward as shown in FIG. 8E, the movable arm 5 of the camera A- 2 operates, thereby panning the camera A- 2 leftward.
In general, there is a scroll bar to scroll a document by an application software of a word processor using the multiwindow or the like. However, as shown in the embodiment, the user interface for controlling the panning is arranged at the same position as that of the scroll bar of the document, so that a desired portion of an object existing at a remote position can be seen by an operating method similar to that of the scroll of the document.
FIGS. 9A to 9 E are explanatory diagrams regarding the zooming control in the embodiment.
As shown in FIG. 9A, by designating and clicking the title bar 312 , the camera A- 2 becomes controllable. In this instance, as shown in FIG. 9B, the color of the title bar 312 is changed, thereby indicating that the camera A- 2 is in a controllable state. Subsequently, as shown in FIG. 9B, when the tele button 311 of the zoom bar 310 of the camera A- 2 is designated and clicked or when the thumb 313 is designated upward and dragged, the camera A- 2 is zoomed in by the lens driving unit of the camera A- 2 . In this instance, while the button 127 of the pointing device 123 is pressed, the zooming operation is performed. When the button is released, the zooming operation is stopped. On the contrary, as shown in FIG. 9C, when the wide button 316 of the zoom bar 310 is designated and clicked or when the thumb 313 is designated and dragged downward, the camera A- 2 is zoomed out by the lens driving unit 102 of the camera A- 2 .
FIG. 9D shows a user interface when the panning and zooming of the camera A- 2 are simultaneously controlled to thereby control a field angle.
As shown in FIG. 9D, when a desired field angle range is designated by dragging the pointing device 123 from the left upper vertex of a desired field angle to the right lower vertex of the desired field angle, the designated field angle range is displayed by a broken line 601 . When the Angle menu 405 of the camera control menu 205 is clicked in this state, the lens driving unit 102 and the movable arm driving unit 113 of the camera A- 2 are controlled. The camera A- 2 is controlled so as to obtain the designated field angle and a display is performed as shown in FIG. 9 E.
FIGS. 10A to 10 D are diagrams showing a user interface when an exposure level of an image of an arbitrary designated range is set to a proper value.
FIG. 10A shows a state in which although the camera A- 1 photographs two persons, a state of the illumination is bad and the right half of the screen is too dark and the left half is too light, so that both of the exposure levels of two persons are not set to the proper levels. In this state, the display window of the camera A- 1 is clicked by the pointing device, thereby setting the camera into the controllable state. When a screen range which should be set into a proper exposing state is designated and dragged by the pointing device as shown in FIG. 10B, a designated rectangular region 602 is displayed by a broken line.
As shown in FIG. 10C, when the AE menu 402 is designated and clicked, both of designated range information instructing to provide a proper exposure and a message to set the exposure level in the designated range to a proper level are sent to the camera A- 1 through the server 17 . The system control circuit 112 of the camera A- 1 controls the iris 103 through the iris driving unit 104 so as to set the image data in the designated rectangular region to a proper level. Thus, as shown in FIG. 10D, the exposure level of the camera A- 1 is controlled and the designated range is set to the proper exposure level. The designated range information of the optimum exposure level in the camera condition table of the server 17 is changed as set in the camera A- 1 .
FIGS. 11A to 11 D are diagrams showing a user interface when the camera is focused on an object in an arbitrary designated range in the embodiment.
FIG. 11A shows a display screen in the case where two persons were photographed by the camera A- 1 . However, since the focusing information is generally obtained by the image data near the center of the screen, if an object like a calendar exists at the center of the screen as shown in the diagram, the camera is focused on the calendar and is not focused on the persons. In such a case, by designating and clicking the title bar 312 of the display window of the camera A- 1 , the camera A- 1 becomes controllable. Subsequently, as shown in FIG. 11B, when the screen range to be focused is designated and dragged by the pointing device, a designated rectangular region 603 is displayed by a broken line.
As shown in FIG. 11C, when an AF menu is clicked, both of focusing range designation information and a message instructing to focus on the designated focusing range are sent to the camera A- 1 through the server 17 . The system control circuit 112 of the camera A- 1 performs a focusing adjustment of the lens 101 through the lens driving unit 102 so as to maximize a sharpness degree of the image in the designated focusing range on the basis of the focusing range designation information, thereby focusing on the designated persons as shown in FIG. 11 D. The designated range information of the focusing range in the camera condition table of the server 17 is also changed as set in the camera A- 1 .
FIGS. 12A to 12 D are diagrams showing a user interface when a white balance is attained on the basis of the image information in an arbitrary designated range in the embodiment.
FIG. 12A shows a state in which since the color of the wall is extremely deep, a white balance cannot be attained according to the average color information of the screen. In such a case, the title bar of the window of the camera A- 1 is designated and clicked by the pointing device, thereby making the camera A- 1 controllable. Subsequently, as shown in FIG. 12B, when a rectangular region which is expected to be white is dragged and designated, a rectangular region 604 is displayed by a broken line. As shown in FIG. 12C, when the AWB menu 405 is designated and clicked, both of the coordinate information of the rectangular region 604 and a message instructing to attain a white balance on the basis of the image information in the rectangular region are sent to the camera A- 1 through the server 17 . The system control circuit 112 of the camera A- 1 controls so as to attain a white balance by the white balance processing 502 from the image information corresponding to the rectangular region 604 . By the above operation, the white balance of the camera A- 1 is attained by the image information of the designated range. The designated range information of the white balance in the camera condition table of the server 17 is also changed as set in the camera A- 1 .
FIGS. 13A to 13 D are diagrams showing a memory function of the field angle setting and its user interface in the embodiment.
It is now assumed that the camera A- 2 has been set to a field angle as shown in FIG. 13 A. In the case where it is presumed that a frequency of the use of such a field angle is large, by clicking the hierarchy menu button 407 of the Angle menu 405 , a Memorize menu 409 is displayed. As shown in FIG. 13B, the cursor 301 of the pointing device 123 is dragged onto the Memorize menu 409 and the button 127 of the pointing device 123 is subsequently released, the field angle set information is stored. At the same time, a reduction image 410 of the image at the field angle appears at a position adjacent to the Memorize menu 409 . Each time the above operation is repeated, a new reduction image is registered at a position adjacent to the Memorize menu 409 .
A method of again setting to the stored field angle will now be described. As shown in FIG. 13C, the cursor 301 of the pointing device 123 is dragged to the position of the registered reduction image indicative of the field angle to be set and the button 127 of the pointing device 123 is subsequently released. Thus, the lens driving unit 102 and movable arm driving unit 113 of the camera A- 2 are controlled as shown in FIG. 13 D and the camera A- 2 is controlled so as to have the designated field angle.
Although the description is omitted, the above method can be used to store not only the setting of the field angle but also the setting of the range to set the exposure level to the optimum exposure level described in the AE menu, the setting of the focusing designated range described in the AF menu, and the setting of the range of the white balance described in the AWB menu.
FIG. 14 shows a display example in case of applying the memory function of the setting and the reduction image to the hierarchical menu of the AE menu. Since the field angle is not changed in case of the AE menu or the like, in order to allow the setting to be easily selected again, the region indicative of the set range in the reduction image is displayed in a broken line rectangular region 605 .
FIGS. 15A to 15 C are diagrams for explaining a user interface when the setting of the camera A- 2 is fixed for a predetermined time.
Changes of the set field angle and other settings from another terminal can be inhibited for a predetermined time. As shown in FIG. 15A, when the title bar 312 of the display window of the camera A- 2 is designated and clicked by the pointing device at the terminal B, the camera A- 2 becomes controllable. As shown in FIG. 15B, subsequently, when the Lock menu 401 is clicked, the camera is fixed to the present set condition of the camera. That is, the control of the camera A- 2 from another terminal is inhibited. In this instance, there is a time limitation in the set fixed time and the remaining time is displayed on a residual time display window 606 . A message indicating that the terminal is in use is displayed in the status display region 314 of the window of the camera A- 2 at the terminals other than the terminal B as shown in FIG. 15 C.
FIG. 16 shows a control flow of a control authorization of the camera.
When the title bar 312 of the display window of the camera A- 2 is designated and clicked at the terminal B, the terminal B is authorized to control the camera A- 2 (S 31 to S 33 ). Subsequently, the color of the title bar 312 of the display window of the camera A- 2 of the terminal B is changed to a selection state (S 34 ). A message indicating that the terminal B is in use is displayed in the camera status display region 314 of the title bar of the display window of the camera A- 2 other than the terminal B (S 35 ). When an event occurs within a predetermined time, the event is analyzed (S 36 , S 37 ). When no event occurs within the predetermined time, it is released to authorize the terminal B to control the camera A- 2 (S 36 , S 38 ). When it is judged by the event analysis that the Lock menu 401 has been selected, the control of the camera A- 2 from another terminal is inhibited for a predetermined time and a residual time to fix the setting of the camera A- 2 is displayed in the residual time display window 606 at the terminal B (S 37 , S 39 , S 40 ). After the elapse of a predetermined time, it is released to authorize the terminal B to control the camera A- 2 (S 38 ). When the event analysis does not indicate the selection of the Lock menu 401 , a message corresponding to the event such as a change of the field angle or the like is sent to the camera A- 2 (S 39 , S 41 ). When the status is changed, the camera sends a condition table updating request message of the camera to the server 17 (S 42 ). The server 17 updates the camera condition table in accordance with the request (S 43 ). When the authorization to control is released, the color of the title bar 312 of the display window of the camera A- 2 of the terminal B is changed to the non-selection state (S 44 ). The display of the camera status display region 314 of the title bar 312 of the display window of the camera A- 2 other than the terminal B is released (S 45 ).
As described above, according to the invention, various settings of the camera at a remote position can be easily controlled by the user interface for control such as menu, button, or the like associated with the display window of the image of the camera.
Particularly, in the panning control of the camera, a desired portion of the object which is photographed by the camera existing at a remote position can be seen by a method similar to that of the scroll of a document in a word processor or the like. Since the controllable attribute or variable range of the camera are automatically reflected to the display of the user interface for control such as menu or the like, the user can easily operate without needing to consider the attribute or the like of the camera at the time of the operation. In the camera at a remote position, the works for adjusting the field angle to an arbitrary portion of the object, for adjusting the focal point, for optimizing the exposure level, and for attaining the white balance can be executed by the unified user interface.
The reduction screen image corresponding to those set conditions can be automatically registered and the registered reduction image functions as a menu when resetting to desired set conditions, so that the operation to select the resetting becomes very easy. By setting such that the set conditions which were set into a desired state cannot be changed for a predetermined time from another terminal, the desired set state can be held for a predetermined time. Both the name of the terminal authorized to control the camera and the message indicating that such a terminal is in use are displayed in the status display region in the display window of the camera at each terminal, so that the operator of another terminal can judge whether the camera is controllable or not and can also easily judge to which terminal the authorization to control should be requested.
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In a video system of the invention, a controller is provided for a terminal input apparatus which is connected by a communication network to a camera on the partner side and which has an image display apparatus with a multi-window display function for selecting and displaying the camera setting. An image pickup operation which is required to operate the camera on the partner side, for example, the image pickup direction, focal distance, panning, exposure amount, white balance, automatic focusing, and the like of the designated camera are input by using an image display and a window display of the image display apparatus. The operation of the camera on the partner side and the operations of a tripod, a movable arm, and the like to hold the camera are controlled through a communicating device. A photographed image is displayed by the display apparatus.
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BACKGROUND OF THE INVENTION
The present invention relates to the field of calenders, and more particularly to devices for controlling the diameter of rolls used in calenders or analogous machines.
Pressing a material between two calender rolls can change the physical characteristics of the material. For example, calendering paper can change its density, thickness and surface features. Thus, the calendering process is frequently used in the manufacture of paper and other sheet materials where it is often desirable to change the density, thickness or surface features of the material.
A common problem associated with calendering is an uneven thickness of the calendered material, or "web". Localized variations in a variety of parameters affect the diameter of individual calendar rolls and create variations in the spacing or "nip" between cooperating rolls. Variations in the nip across the width of a pair of calender rolls produces a web having non-uniform thickness. Thus, a more uniform thickness could be obtained if the local diameters of the rolls could be controlled.
If the rolls are made of a material that responds to changes in temperature, one may control local roll diameters by varying the temperature of selected cylindrical sections of the calender roll. Previous devices have used this principle by directing jets of hot or cold air against sections of a rotating calender roll to control its local diameters. Many of these devices blow hot air from a supply plenum against sections of the calender roll to increase the diameter of the roll and thus decrease the thickness of the web. Alternatively, when these devices release cold air from a second supply plenum against selected cylindrical sections of the calender roll, those sections contract. This decreases the local roll diameter and increases the thickness of the web. Examples of such devices are shown in U.S. Pat. No. 4,114,528 to Walker and U.S. Pat. No. 3,770,578 to Spurrell.
These previously known devices, however, are subject to certain limitations and inefficenicies. For example, the nip control range is determined by the maximum and minimum temperatures of the air jets. The air in the hot air plenum is usually pressurized by a blower and heated by steam from the facility power plant. Typically, however, steam supplied by such a power plant is waste steam, having a maximum temperature of about 350° F. Inefficiencies in the heat exchange process further limit the maximum temperature of such steam heated air to about 325° F.
The calender roll control device of the present invention has a number of features which overcome many of the disadvantages of many air jet control devices heretofore known. For example, the present invention uses jets of steam to heat the calender roll. The direct use of steam avoids the inefficiencies in the air heating process. Additionally, since the invention uses steam jets rather than steam-heated air, the higher temperature provides a greater control range then conventional hot air devices. Furthermore, the invention does not require a blower to pressurize an air plenum. Instead, the steam plenum used with the present invention is pressurized directly by the thermal energy of the steam.
Another type of prior calender roll control device uses magnetic fields to heat the calender roll, for example, as shown in U.S. Pat. No. 4,384,514 to Larive et al. In this type of device, the roll is made of a conducting material and magnets are positioned close to the roll surface. As the rotating roll passes under the magnets, cylindrical sections of the roll are heated by magnetic induction. The magnetic fields induce currents in the calender roll which dissipate their energy heating the roll. However, because ordinary 50/60 Hz electromagnets have high magnetic forces which may bend the roll, 25 Khz alternating current electromagnets are generally used. Thus, effective magnetic induction calender roll control devices require a special alternating current power supply.
Furthermore, to achieve the greatest heating effect, the magnets should be positioned within about 1/8" of the roll surface. However, placing the magnets this close to the calender roll may lead to damage when the web breaks. The broken web can wrap around the roll a sufficient number of times to build up a thick layer of calendered material on the roll. Once the layer becomes more than 1/8" thick, the rotating calender roll can drive the paper into the magnets with sufficient force to damage both the magnets and their supporting structure.
The device of the present invention also provides a number of advantages over magnetic induction calender roll control devices. For example, the invention does not require a special alternating current power supply to energize electromagnets. Instead, the invention heats the calender rolls with steam which is generally a less costly form of energy then electricity. Electric power is a relatively expensive energy source since the steam to electric power conversion process is usually only about 44% efficient. The direct use of steam to heat the calender roll is more economical. Furthermore, depending upon the particular application, the steam nozzles used in the present invention to direct steam jets against the calender roll are usually positioned approximately two inches from the roll surface. This two inch gap between the nozzles and the calender roll greatly decreases the possibility of damage to the nozzle by contact with the calendered material.
The present invention thus provides a number of advantages over prior art calender roll control devices. These and other advantages will become apparent in the description which follows.
SUMMARY OF THE INVENTION
The present invention is directed toward a controller for controlling local calender roll diameters by selectively directing jets of steam against sections of the calender roll. The roll is made of a material having at least one dimension which responds to changes in temperature. Therefore, thermal expansion, resulting from localized heating by the steam jets, corrects non-uniformities in the nip formed between cooperating calender rolls. Moisture that condenses from the steam onto the roll surface is removed before it wets the calendered material.
In the illustrated embodiments, the invention comprises a plurality of nozzles which direct jets of steam at a rotating calender roll. The nozzles are dispersed at intervals along the length of the roll so that steam escaping from each nozzle affects the diameter of a particular section of the roll. A valve associated with each nozzle controls the volume of steam discharged by the nozzle. When a valve opens, steam escapes from the associated nozzle and heats the adjacent section of the calender roll. This steam heating causes the adjacent section of calender roll to expand, thereby contracting the nip formed between cooperating calender rolls. As a result, the narrowed section of nip produces a thinner web.
The steam is preferrably superheated to minimize condensation of the roll. Condensation will wet the calendered material, which may be adversely affected by water. Any condensation which does occur, however, may be sucked off the surface of the roll by a vacuum plenum having an inlet port near the surface of the roll. Furthermore, the steam jets are preferrably directed against the side of the calender roll moving away from the nip. As the hot calender roll rotates, the exposed area of the roll travelling from the steam jets back to the nip allows any remaining condensate to evaporate before reaching the nip.
To maintain a uniform thickness of calendered material, a valve control device controls the valves and hence the heating of each section of the calender roll. In the illustrated embodiments, a web thickness sensor measures the thickness of the web at intervals along its width and generates signals corresponding to the measured thicknesses. The signals from the sensor are fed to a valve control device which maintains a uniform web thickness by adjusting the steam valves to thereby control the diameter of particular sections of the temperature sensitive calender roll.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional view of one embodiment of the present invention having two rows of steam jets directed against the lowermost calender roll and a vacuum plenum for removing moisture from the roll.
FIG. 2 is a front view of the steam jet and plenum structure taken along the line 2--2 of FIG. 1.
FIG. 3 illustrates another embodiment of the present invention having a single row of steam jets directed against an intermediate calender roll and a shroud for preventing cold air entrainment.
FIG. 4 illustrates still another embodiment of the present invention supported by an over-center support mechanism.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The first embodiment of the present invention is illustrated in FIG. 1. The invention comprises a steam plenum 5 containing superheated steam at 500° F. and 10 psig. A plurality of hollow cylinders 7 communiate with the interior of the plenum 5 so that steam from the plenum 5 enters the cylinders 7. A nozzle 9 is positioned at the exterior end of each cylinder 7 to direct a jet of steam against adjacent sections of the calender roll 11 to control its local diameters.
A valve 13 associated with each hollow cylinder 7 controls the flow of steam from the plenum 5 to each nozzle 9. Each valve 13 comprises a plug 15 which gradually opens and closes an orifice 17 located in the wall of the cylinder 7. A rod 19 controls the plug 15 which in turn is controlled by air pressure acting on a diaphragm 21. The air pressure works against a spring 23 which holds the plug 15 in the closed position. Increasing the air pressure displaces the plug 15 away from the orifice 17, thereby allowing more steam to escape through the nozzle 9.
When a valve 13 opens, steam escapes from the plenum 5 through the hollow cylinder 7 and its associated nozzle 9. The steam jet heats the section of calender roll 11 which is adjacent to the nozzle 9. As the temperature of the heated section of calender roll 11 increases, the thermally expanding roll 11 decreases the size of the nip 25 formed between the heated section of calender roll 11 and the adjacent cooperating roll 27. Thus, the heated section of calender roll 11 produces a thinner section of calendered material 29.
The steam in the plenum 5 is superheated by a steam superheating device 30 (see FIG. 2) to minimize condensation on the calender roll 11 which may otherwise wet the calendered material 29. However, any steam which does condense on the roll 11 is sucked off the roll surface 31 by a vacuum plenum 33.
Four shims provide a means for substantially enclosing the volume bonded by the steam plenum 5, the calender roll 11, and the vacuum plenum 33. Two of the shims 35, 37 are illustrated in FIG. 1. The two remaining shims 39, 41 are illustrated in FIG. 2, which is a front view of the device along the line 2--2 of FIG. 1. The first shim 35 extends between the top of the steam plenum 5 and the calender roll 11. The second shim 37 is positioned between the vacuum plenum 33 and the calender roll 11. The two remaining shims 39, 41, illustrated in FIG. 2, are positioned at either end of the plenums and complete the enclosure. Therefore, air sucked into the vacuum plenum 33 passes through the narrow gap between the shims 35, 37, 39, 41 and the calender roll 11. The flow of air rushing through this gap removes condensate from the calender roll surface 31 and is sucked into the vacuum plenum 33.
To further insure that no condensate wets the calendered material 29, the steam jets are located on the side of the calender roll 11 which moves away from the nip 25. The roll is typically maintained at an average temperature of about 190° F. Therefore, the exposed area of the hot calender roll 11 extending from the second shim 37 to the nip 25 evaporates any remaining condensate before it reaches the nip 25.
A doctor blade 43 extends along the length of the calender roll 11 and is positioned above the calender roll control device to protect the device from pieces of the calendered material which may break off of the calendered sheet 29. The vacuum plenum 33 is also protected by a filter 45. The filter 45 covers the inlet port 47 of the vacuum plenum 33 and prevents particles of the calendered material or other foreign matter from entering the vacuum plenum 33.
As shown in FIG. 2, a plurality of nozzles 9 are positioned along the length of the steam plenum 5. The nozzles 9 are disposed in two rows and dispersed at intervals along the length of the plenum 5 corresponding to sections of the calender roll 11 whose diameters are to be controlled. Typically, each section of calender roll or "slice" is about six inches wide. However, depending upon the particular situation, each slice may be wider or narrower. Additional nozzles 49 are located near the ends of the plenum 5 to compensate for the increased cooling tendency of the calender roll ends.
As shown in FIG. 1, a computerized valve control device 50 controls the heating of each section of the calender roll 11 to maintain a uniform thickness of calendered material 29. A web thickness sensor 51 senses the thickness of the calendered material 29 at various locations along its width and sends signals, which correspond to the thicknesses of the material, to the control device 50. Depending on the degree of deviation of the calendered material 29 from the desired thickness, the valve control device 50 selectively directs air pressure against certain diaphragms 21 which in turn adjust the associated valves 13 so that the valves discharge a greater or lesser amount of steam from each nozzle 9.
If the sensor 51 detects a thick section of calendered material 29, the control device 50 adjusts the valve 13 adjacent to that section of the calender roll 11 and allows more steam to heat that section of the roll 11. The additional steam heating the section of the calender roll 11 causes it to expand. The expanding section of the calendar roll 11 decreases the corresponding section of nip 25, thus decreasing the thickness of the calendered material 29 produced by the heated section of the roll 11.
Alternatively, when the sensor 51 detects a thin section of calendered material 29, the control device 50 adjusts the valve 13 adjacent to that section of the calender roll 11 to allow less steam to heat the roll 11. Since less steam is directed at that section of the roll 11, it cools and contracts. This increases the nip 25 formed between the cooperating calender rolls 11, 27 and results in a thicker section of calendered material 29.
FIG. 3 illustrates a second preferred embodiment of the present invention. It operates in essentially the same manner as the first embodiment. However, the plenum 105 is supported by an arm 152 and positioned so that a single row of nozzles 109 direct steam against an intermediate calender roll 111. Furthermore, although a vacuum plenum could be used with this device, FIG. 3 illustrates operation without a vacuum plenum.
The steam jet nozzles 109 are shown protruding from a concave shroud 160 having approximately the same curvature as the surface of the calender roll 111. The shroud 160 acts to constrain the steam emitted from the nozzles 109 to remain in contact with the calender roll 111, thus enhancing the efficiency of the heat transfer to the roll 111. The shroud 160 also prevents cold ambient air from being entrained by the steam jets. The cold air would reduce the effective temperature of the jets. Of course, a similar shroud could be used with the embodiment of the invention illustrated in FIG. 1.
The support member of arm 152 is mounted on the drive shaft 154 of a motor 156. When the motor 156 is activated, the drive shaft 154 and supporting arm 152 pivot the plenum 105, nozzles 109, valves 113 and shroud 160 away from the calender roll 111 for convenient inspection, repair or replacement of the device.
Alternatively, the calender roll control device may be supported by an over-center support mechanism, as shown in FIG. 4. In this embodiment, a rigid pivotable support member on arm 252 is disposed at either end of the steam plenum 205. These arms 252 support the plenum 205 so that the plenum 205 and shroud 260 are pivotable toward or away from the calender roll 211.
An extendible air cylinder 264 is associated with each pivotable arm 252. Pressurizing the cylinders 264 with air causes them to expand, thus rocking the plenum 205 and shroud 260 away from the calender roll 211.
In the operating position, each air cylinder 264 is pressurized so that the calender roll control device leans slightly toward the calender roll 211. In this metastable position, if the web 229 breaks and wraps around the roll 211, a slight forceful contact between the web 229 and the shroud 260 is sufficient to rock the device back away from the calender roll 211 and thus avoid damage to the device.
Three embodiments of the present invention have been described. Nevertheless, it is understood that one may make various modifications without departing from the spirit and scope of the invention. Thus, the invention is not limited to the embodiments described herein.
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A device for selectively controlling the diameter of sections of a calender roll. The device comprises a plurality of nozzles which direct jets of superheated steam against sections of the calender roll. Thermal expansion, resulting from localized heating by the steam jets, corrects local non-uniformities in the gap between adjacent cooperating calender rolls. Moisture which condenses from the steam onto the calender roll surface is removed by a flow of air past the roll surface.
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FIELD OF THE INVENTION
This invention relates to Analog-to-Digital Converters (ADC), and more particularly to a comparator for an ADC.
BACKGROUND OF THE INVENTION
Offset voltages on differential inputs cannot be tolerated for some high-precision applications. One common application is a high-resolution Analog-to-Digital Converter (ADC). An ADC cannot tolerate an input offset that is greater than the least-significant-bit (LSB) since the LSB precision would be lost.
Since the gain-bandwidth product of a single stage amplifier is constant, several amplifier stages are often cascaded together. The cascade provides a desired amplification factor with minimal delay. A cascade of pre-amplifiers can amplify a small input charge to produce a sufficiently large output charge that may then drive a latch that is part of a precision device such as an ADC.
However, any random input offsets in the cascade of pre-amplifiers can be propagated through the cascade of amplifier stages and the final amplified offset can significantly degrade the precision of the system.
Auto-zeroing techniques may be used to cancel such offsets. Often two phases are used to clock the cascade of amplifiers, where offset charges are stored in one phase and signal amplification occurs in the other phase.
Power supply voltages have been reduced to avoid damaging transistors that have been shrunk for advanced semiconductor processes. The lower power-supply voltage results in circuit design challenges since transistor saturation voltages may cut the remaining power-supply voltage in some circuits. The remaining voltage may be further reduced by I*R voltage drops through resistors. Traditional amplifier circuits with a saturated transistor in series with a resistor may leave little room for amplifying transistors to operate when the supply voltage is reduced.
What is desired is a pre-amplifier stage that eliminates an I*R drop due to a resistor in series with a saturated transistor. An amplifier that can operate with reduced power supply voltages is desirable. An amplifier with auto-zeroing and a folded resistor circuit design is desired for precision applications such as for an ADC.
Precision ADC Application— FIGS. 1-2
A pre-amplifier with auto-zeroing of input offsets may be used in a precision ADC application such as described below for FIGS. 1-2 . The pre-amplifier may be used for other precision applications such as a low noise amplifier, a high precision instrumentation amplifier, a high precision comparator, any offset cancellation amplifier, DAC, etc.
Successive-approximation ADC's use a series of stages to convert an analog voltage to digital bits. Each stage compares an analog voltage to a reference voltage, producing one digital bit. In sub-ranging ADC's, each stage compares an analog voltage to several voltage levels, so that each stage produces several bits. Succeeding stages generate lower-significant digital bits than do earlier stages in the pipeline.
Algorithmic, re-circulating, or recycling ADC's use a loop to convert an analog voltage. The analog voltage is sampled and compared to produce a most-significant digital bit. Then the digital bit is converted back to analog and subtracted from the analog voltage to produce a residue voltage. The residue voltage is then multiplied by two and looped back to the comparator to generate the next digital bit. Thus the digital bits are generated over multiple cycles in the same comparator stage.
FIG. 1 shows a Successive-Approximation-Register ADC. Successive-Approximation-Register SAR 302 receives a clock CLK and contains a register value that is changed to gradually zero-in on a close approximation of the analog input voltage VIN. For example, the value in SAR 302 may first be 0.5, then 0.25, then 0.32, then 0.28, then 0.30, then 0.31, then 0.315, then 0.313, then 0.312, when comparing to a VIN of 0.312 volts. SAR 302 outputs the current register value to digital-to-analog converter (DAC) 300 , which receives a reference voltage VREF and converts the register value to an analog voltage VA.
The input analog voltage VIN is applied to sample-and-hold circuit 304 , which samples and holds the value of VIN. For example, a capacitor can be charged by VIN and then the capacitor isolated from VIN to hold the analog voltage. The sampled input voltage from sample-and-hold circuit 304 is applied to the inverting input of comparator 306 . The converted analog voltage VA is applied to the non-inverting input of comparator 306 .
Comparator 306 compares the converted analog voltage VA to the sampled input voltage and generates a high output when the converted analog voltage VA is above the sampled VIN, and the register value in SAR 302 is too high. The register value in SAR 302 can then be reduced.
When the converted analog voltage VA is below the sampled input voltage, comparator 306 generates a low output to SAR 302 . The register value in SAR 302 is too low. The register value in SAR 302 can then be increased for the next cycle.
The register value from SAR 302 is a binary value of N bits, with D(N-1) being the most-significant-bit (MSB) and D0 being the least-significant-bit (LSB). SAR 302 can first set the MSB D(N-1), then compare the converted analog voltage VA to the input voltage VIN, then adjust the MSB and/or set the next MSB D(N-2) based on the comparison. The set and compare cycle repeats until after N cycles the LSB is set. After the last cycle, the end-of-cycle EOC signal is activated to signal completion. A state machine or other controller can be used with or included inside SAR 302 to control sequencing.
Comparator 306 can be replaced with a series of pre-amplifier stages and a final latch. FIG. 2A is a response graph of pre-amplifier and latch stages. The pre-amplifier stages have a negative response shown by curve 312 , while the final latch has a positive response as shown by curve 310 . For low voltages, curve 312 is above and to the left curve 310 , indicating that the pre-amplifiers require less time to achieve the same VOUT voltage than the latch. However, for higher VOUT voltages, curve 310 is above curve 312 , indicating that for larger values of VOUT, the latch can achieve these larger voltage outputs much faster than the pre-amplifiers.
FIG. 2B shows a series of pre-amplifiers and a final latch. Pre-amplifier stages 320 , 322 , 324 , 326 , 328 are amplifiers that boost the voltage difference between VIN and VA. Especially near the end of comparison when the LSB is being set, the difference between VIN and VA can be quite small. This voltage difference is gradually increased by the pre-amplifier stages until the final stage. Latch stage 330 latches this voltage difference to generate the compare signal that is fed back to SAR 302 . Thus stages 320 - 330 replace comparator 306 of FIG. 1 .
By combining a series of pre-amplifier stages with the positive response of the final latch, a fast response time can be achieved. The pre-amplifier stages can gradually amplify and enlarge the voltage difference between VIN and VA until the amplified voltage difference is large enough to drive the final latch. The delay time can be minimized by using low-gain, wide bandwidth pre-amplifiers.
What is desired is a pre-amplifier stage that can be used in a precision ADC. A pre-amplifier that eliminates an I*R drop due to a resistor in series with a saturated transistor and can operate with reduced power supply voltages is desirable. An amplifier with auto-zeroing and a folded resistor circuit design is desired for precision applications such as for the ADC of FIG. 1 .
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a Successive-Approximation-Register ADC.
FIG. 2A is a response graph of pre-amplifier and latch stages.
FIG. 2B shows a series of pre-amplifiers and a final latch.
FIG. 3 is a diagram of a high-speed latch.
FIG. 4 is a schematic of a first embodiment of a pre-amplifier stage with a folded resistor.
FIG. 5 is a waveform showing autozeroing by the pre-amplifier.
FIG. 6 is a waveform showing an offset being stored in the pre-amplifier.
FIG. 7 is a second embodiment of the pre-amplifier with kickback charge isolation.
FIG. 8 is a third embodiment of the pre-amplifier with equalization.
DETAILED DESCRIPTION
The present invention relates to an improvement in precise auto-zeroing comparators and amplifiers. The following description is presented to enable one of ordinary skill in the art to make and use the invention as provided in the context of a particular application and its requirements. Various modifications to the preferred embodiment will be apparent to those with skill in the art, and the general principles defined herein may be applied to other embodiments. Therefore, the present invention is not intended to be limited to the particular embodiments shown and described, but is to be accorded the widest scope consistent with the principles and novel features herein disclosed.
FIG. 3 is a diagram of a high-speed latch. The high-speed latch of FIG. 3 generates latched output OUT that can be part of an ADC, such as SAR 302 of FIG. 1 . The latch inputs LATP, LATN can be the output of a final stage in a cascade of pre-amplifiers such as shown in FIG. 2B , using one of the circuits of FIGS. 4-6 for each stage in the cascade.
A bias voltage BIASP is applied to the gate of p-channel bias transistor 46 , which provides current to the sources of p-channel differential transistors 48 , 49 . The latch input LATP, LATN is a differential signal that is output from a final stage in a cascade of pre-amplifier stages. LATP is applied to the gate of p-channel differential transistor 48 while LATN is applied to the gate of p-channel differential transistor 49 .
Cross-coupled NAND gates 40 , 42 form a bi-stable that drive output OUT through inverter 44 . Cross-coupled p-channel transistors 22 , 24 assist the settling of the bi-stable when CLK is high and CLKB is low, turning off transmission gate transistors 30 , 32 , 34 , 36 and turning on p-channel source transistors 20 , 26 to hold the state of the inputs to NAND gates 40 , 42 .
When CLK is low and CLKB is high, p-channel source transistors 20 , 26 turn off and transmission gate transistors 30 , 32 , 34 , 36 turn on, allowing the latch to be set or reset by inputs LATP, LATN. N-channel cascode transistors 28 , 29 receive a cascode bias voltage CASCN on their gates and each form a source-follower connection to the transmission gates. Current is pulled through n-channel cascode transistors 28 , 29 by n-channel current sink transistors 38 , 39 when transmission gates are open (CLKB high).
LATP applied to the gate of p-channel differential transistor 48 steers less current to the drain of n-channel current sink transistor 38 when LATP is higher than LATN. This allows more current to flow through cascode transistor 28 , pulling the input to NAND gate 42 lower and setting OUT high.
FIG. 4 is a schematic of a first embodiment of a pre-amplifier stage with a folded resistor. Feedback resistors 50 , 52 are not in series between the power supply and ground, and thus do not reduce the available voltage by a V=I*R drop. This allows for two p-channel transistors and one saturated n-channel transistor in series between Vcc and ground in the main section of the amplifier (transistors 68 , 60 , 54 ), and two p-channel transistors, one transmission gate, and one saturated n-channel transistor in series between Vcc and ground in the feedback section of the amplifier (transistors 30 , 74 , 70 / 72 , 76 ). The power supply can be as low as three times the saturated transistor voltage drop, or 3*VDSAT.
The circuit of FIG. 4 can be the first stage in a cascade of pre-amplifiers, or any of the intermediate stages, or the final stage that drives the latch of FIG. 3 . Inputs INP, INN can be the LATP, LATN outputs from a prior stage amplifier, or can be the external inputs when the amplifier is the first stage. Similarly, outputs LATP, LATN can drive the INP, INN inputs of a next stage in the cascade, or can drive the LATP, LATN inputs of the latch of FIG. 3 .
Switches 61 , 65 connect INP to gate node GP of p-channel differential transistor 60 when autozeroing signal AZ is low, but ground gate node GP during autozeroing. Similarly, switches 63 , 67 connect INN to gate node GN of p-channel differential transistor 62 when autozeroing signal AZ is low, but ground gate node GN during autozeroing.
N-channel current sink transistors 54 , 56 receive common-mode feedback bias voltage CMFB on their gates and sink current from the drains of p-channel differential transistors 60 , 62 , which are also latch outputs LATN, LATP, respectively.
P-channel source transistor 68 receives a bias voltage BIASP and provides current to the sources of p-channel differential transistors 60 , 62 in the main amplifier section. In the feedback section, p-channel source transistor 30 also receives bias voltage BIASP, and provides current to the sources of p-channel feedback transistors 74 , 84 .
The feedback section of the pre-amplifier has n-channel autozeroing sink transistors 76 , 86 that receive autozeroing signal AZB on their gates and turn on in the linear (triode) region when AZB is high. Since AZB swings to Vcc, while CMFB is a lower voltage, transistors 54 , 56 in the amplifier section operate in the saturated region while transistors 76 , 86 in the feedback section operate in the linear region.
During autozeroing, offset charges are stored on offset capacitors 78 , 88 . Transmission gate transistors 70 , 72 , 80 , 82 turn on and autozeroing sink transistors 76 , 86 turn off. Gates nodes GP, GN are grounded by switches 65 , 67 so that inputs are disconnected from the main amplifier section. This isolation during autozeroing allows and offsets on differential transistors 60 , 62 to pass through feedback resistors 50 , 52 and transmission gate transistors 70 , 72 , 80 , 82 to be stored on offset capacitors 78 , 88 .
The offsets stored on offset capacitors 78 , 88 are applied to the gates of p-channel feedback transistors 74 , 84 , which have drains driving LATN, LATP. Thus the offsets are fed back through a feedback loop of feedback resistors 50 , 52 and feedback transistors 74 , 84 . Charges stored on offset capacitors 78 , 88 are adjusted by the feedback loop until steady-state is reached. The pre-amplifier is configured as a high-gain amplifier during autozeroing to store the offsets.
When autozeroing is completed, the offset charges are stored on offset capacitors 78 , 88 . During the next (amplifying) phase, AZB is high and AZ is low. Comparison and amplification of the INP, INN inputs can occur since switches 61 , 63 close to connect INP, INN to the gates of differential transistors 60 , 62 .
Autozeroing sink transistors 76 , 86 turn on and operate in the linear region. Transmission gate transistors 70 , 72 , 80 , 82 turn off to isolate nodes RN, RP from nodes FN, FP, The offset charges on offset capacitors 78 , 88 are applied to the gates of feedback transistors 74 , 84 and are amplified to drive the stored offsets onto LATN, LATP to compensate for offsets in differential transistors 60 , 62 or other parts of the circuit.
During the amplifying phase, the pre-amplifier is configured as a high-speed low-gain amplifier. The gain of the pre-amplifier during this phase is determined by the resistance of feedback resistors 50 , 52 , such as 300K-Ohms. Since feedback resistors 50 , 52 are in a folded circuit configuration, the power-supply voltage to differential transistors 60 , 62 is not reduced by the I*R drop through feedback resistors 50 , 52 .
FIG. 5 is a waveform showing autozeroing by the pre-amplifier. An offset voltage of −2.92 mV is applied to the inputs INP, INN during a simulation. Autozeroing starts at about 345 us and ends at about 349 us in the simulation. The pre-amplifier performs sample and conversion during the several pulses shown. During several cycles this offset is stored on offset capacitors 78 , 88 and the feedback loop causes LATP, LATN to eventually equalize and settle at about 0.3 volts.
FIG. 6 is a waveform showing an offset being stored in the pre-amplifier. An offset voltage of −2.92 mV is applied to the inputs INP, INN during a simulation. During several autozeroing cycles, nodes FP, FN, which are also the voltages of offset capacitors 78 , 88 , settle between 0.48 and 0.49 volts, with a difference of −2.97 mV representing the stored offset. Note that the stored offset of −2.97 mV is only 0.05 mV off from the true offset of −2.92 mV. This represents an error of only 1.7% of the injected offset.
FIG. 7 is a second embodiment of the pre-amplifier with kickback charge isolation. Kickback-charge isolation transistors 172 , 174 , 176 , 178 are grounded-gate p-channel transistors that isolate kickback charge between the feedback and main amplifier sections. Kickback charge refers to charge injection during switching. Isolating the kickback charge has the advantage of preventing charge injection from disturbing the comparator.
Since the gates of kickback-charge isolation transistors 172 , 174 , 176 , 178 are grounded, these operate in the linear region and do not cut a significant part of the supply voltage headroom. However, there is some voltage loss due to these transistors.
FIG. 8 is a third embodiment of the pre-amplifier with equalization. Equalizing transistors 160 , 162 are added. When an equalization clock CLK is high, transistors 160 , 162 turn on, shorting LATP to LATN. CLK can be pulsed high just before every comparison to allow for a faster settling of LATP, LATN. This forces and adjustment to the charge stored on offset capacitors 78 , 88 .
CMFB is Common Mode Feedback. The CMFB signal is used during autozeroing as the preamplifier is reconfigured as a fully differential opamp. The CMFB signal is generated by another copy of the low voltage preamplifier with an output diode connected. This copy of the preamplifier does not require a high gain and is off during comparison An example of voltages of internal nodes is AZ=1V, AZB=0V, FB and FN=0.5V, CMFB=0.5V, and the power Vcc voltage is 1V. The process gate length in microns is 0.18 um in this example.
ALTERNATE EMBODIMENTS
Several other embodiments are contemplated by the inventors. For example other embodiments may be combinations of those shown. Equalizing transistors 160 , 162 could be added without adding kickback-charge isolation transistors 172 , 174 , 176 , 178 . Switches can be implemented as transmission gates with p-channel and n-channel transistors in parallel, or as a single transistor, either p-channel or n-channel. A different latch circuit may be used with the pre-amplifier. While an ADC application has been shown, the pre-amplifier could be used in other circuits, such as DACs, comparators, low noise amplifiers, instrumentation amplifiers, or any offset cancellation amplifier.
Buffers, inverters, gating logic, capacitors, resistors, or other elements may be added at various locations in the circuit for a variety of reasons unrelated to the invention, such as for power savings modes.
Signals may be encoded, compressed, inverted, combined, or otherwise altered. Clocks may be combined with other signals or conditions. The entire circuit or portions of it could be inverted and p-channel and n-channel transistors swapped.
Directional terms such as upper, lower, up, down, top, bottom, etc. are relative and changeable as the system, circuit, or data is rotated, flipped over, etc. These terms are useful for describing the device but are not intended to be absolutes. Signals may be active high or active low, and may be inverted, buffered, encoded, qualified, or otherwise altered.
Additional components may be added at various nodes, such as resistors, capacitors, inductors, transistors, etc., and parasitic components may also be present. Enabling and disabling the circuit could be accomplished with additional transistors or in other ways. Pass-gate transistors or transmission gates could be added for isolation. Inversions may be added, or extra buffering. The final sizes of transistors and capacitors may be selected after circuit simulation or field testing. Metal-mask options or other programmable components may be used to select the final capacitor, resistor, or transistor sizes.
P-channel rather than n-channel transistors (or vice-versa) may be used for some technologies or processes, and inversions, buffers, capacitors, resistors, gates, or other components may be added to some nodes for various purposes and to tweak the design. Timings may be adjusted by adding delay lines or by controlling delays. Separate power supplies and grounds may be used for some components. Various filters could be added. Active low rather than active high signals may be substituted.
While positive currents have been described, currents may be negative or positive, as electrons or holes may be considered the carrier in some cases. Source and sink currents may be interchangeable terms when referring to carriers of opposite polarity. Currents may flow in the reverse direction. A fixed bias voltage may be switched to power or ground to power down the circuit.
While Complementary-Metal-Oxide-Semiconductor (CMOS) transistors have been described, other transistor technologies and variations may be substituted, and materials other than silicon may be used, such as Galium-Arsinide (GaAs) and other variations.
The background of the invention section may contain background information about the problem or environment of the invention rather than describe prior art by others. Thus inclusion of material in the background section is not an admission of prior art by the Applicant.
Any methods or processes described herein are machine-implemented or computer-implemented and are intended to be performed by machine, computer, or other device and are not intended to be performed solely by humans without such machine assistance. Tangible results generated may include reports or other machine-generated displays on display devices such as computer monitors, projection devices, audio-generating devices, and related media devices, and may include hardcopy printouts that are also machine-generated. Computer control of other machines is another tangible result.
Any advantages and benefits described may not apply to all embodiments of the invention. When the word “means” is recited in a claim element, Applicant intends for the claim element to fall under 35 USC Sect. 112, paragraph 6. Often a label of one or more words precedes the word “means”. The word or words preceding the word “means” is a label intended to ease referencing of claim elements and is not intended to convey a structural limitation. Such means-plus-function claims are intended to cover not only the structures described herein for performing the function and their structural equivalents, but also equivalent structures. For example, although a nail and a screw have different structures, they are equivalent structures since they both perform the function of fastening. Claims that do not use the word “means” are not intended to fall under 35 USC Sect. 112, paragraph 6. Signals are typically electronic signals, but may be optical signals such as can be carried over a fiber optic line.
The foregoing description of the embodiments of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many modifications and variations are possible in light of the above teaching. It is intended that the scope of the invention be limited not by this detailed description, but rather by the claims appended hereto.
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A pre-amplifier circuit can be cascaded and drive a latch for use in a precision analog-to-digital converter (ADC). The pre-amplifier has a main section and a feedback section connected by feedback resistors that do not produce voltage drops in the main section. Offset is stored on offset capacitors during an autozeroing phase and isolated by transmission gates during an amplifying phase. The offset capacitors drive the gates of feedback transistors that drive output nodes in the main section. Autozeroing sink transistors in the feedback section operate in the linear region while current sink transistors in the main section operate in the saturated region. Kickback-charge isolation transistors may be added for charge isolation. The output may also be equalized by an equalizing transmission gate. A very low power-supply voltage is supported even for high-speed operation with offset cancellation, due to the folded feedback resistor arrangement.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates generally to charge rate optimization, and more specifically, but not exclusively, to implementation of a charge rate at less than a maximum fast rate based upon user requirements for optimization of secondary considerations of economy, battery life, or the like when primary considerations of SOC and charge completion time targets are not adversely impacted by a slower charge rate.
[0002] Charging high performance battery packs implicate many nuanced considerations and subtleties in order to maximize sometimes competing goals of maximum battery pack lifetime, performance, and availability. For user convenience, fast chargers have been designed and implemented for personal and public charging stations. These chargers are designed to quickly restore a user's access to their electric vehicle. This enhanced charging speed comes at a potential cost of degrading battery life.
[0003] For many electric vehicle (EV) users, recharging their EV as quickly as possible is considered very important, and these users select the fastest charging option whenever possible even when a slower charging option may be more economical, more efficient, and/or better for the battery pack. What is needed is a system and method providing fast charge optimization based upon user need.
BRIEF SUMMARY OF THE INVENTION
[0004] Disclosed is a system and method providing fast charge optimization based upon user need. Manually or automatically determined or inferred actual user need is used to optimize charging rate when the user does not otherwise require the full charging rate over the entire charging period (the maximum fast charge is always available).
[0005] The following summary of the invention is provided to facilitate an understanding of some of technical features related to fast charge optimization, and is not intended to be a full description of the present invention. A full appreciation of the various aspects of the invention can be gained by taking the entire specification, claims, drawings, and abstract as a whole. The present invention is applicable to other charging scenarios in addition public charging of electric.
[0006] An electric charging system for an energy storage system includes a charging station electrically coupled to the energy storage system, the charging station transferring charging energy to the energy storage system at a maximum fast charge rate in a first operational mode and transferring charging energy to the energy storage system at a slower charge rate in a second operational mode, the modes responsive to a control signal; a data collection system acquiring a set of data indicating a state of charge (SOC) of the energy storage system and one or more desired charge optimization parameters; and a station control, responsive to the set of data and to the desired charge optimization parameters, automatically establishing a charging profile for the energy storage system to assert the control signal and operate the charging station in the second operational mode whenever the charging station is able to transfer sufficient energy to the energy storage system at the slower charge rate to meet an SOC target and a charge completion time target, otherwise asserting the control signal and operate the charging station in the first operational mode.
[0007] A computer-implemented charging method for an energy storage system including a) collecting data to answer an optimization query designed to establish an SOC target and a charge completion time target for the energy storage system, a primary consideration for charging the energy storage system including satisfaction of the SOC target and the charge completion target; b) determining using a microprocessor system whether a satisfaction of the primary consideration requires a maximum fast charge rate from a charging station coupled to the energy storage system; c) charging the energy storage system at the maximum fast charge rate when required to attempt to satisfy the primary consideration; otherwise d) charging the energy storage system at a secondary charge rate slower than the fast charge rate to satisfy the primary consideration when satisfying the primary consideration does not require the maximum fast charge rate, the secondary charge rate responsive to one or more secondary considerations including one or more of an improved economical charging cycle and an improved lifetime for the energy storage system.
[0008] Other features, benefits, and advantages of the present invention will be apparent upon a review of the present disclosure, including the specification, drawings, and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The accompanying figures, in which like reference numerals refer to identical or functionally-similar elements throughout the separate views and which are incorporated in and form a part of the specification, further illustrate the present invention and, together with the detailed description of the invention, serve to explain the principles of the present invention.
[0010] FIG. 1 illustrates an enhanced charging station having user-need optimization features; and
[0011] FIG. 2 illustrates a flowchart for an enhanced charging process.
DETAILED DESCRIPTION OF THE INVENTION
[0012] Embodiments of the present invention provide a system and method providing fast charge optimization based upon user need. The following description is presented to enable one of ordinary skill in the art to make and use the invention and is provided in the context of a patent application and its requirements.
[0013] Various modifications to the preferred embodiment and the generic principles and features described herein will be readily apparent to those skilled in the art. Thus, the present invention is not intended to be limited to the embodiment shown but is to be accorded the widest scope consistent with the principles and features described herein.
[0014] FIG. 1 illustrates an enhanced charging system 100 including an optimized fast charging station 105 having user-need optimization features. Fast charging station 105 supplies electrical energy for recharging energy storage systems (e.g., high-performance battery packs used in electric vehicles, plug-in hybrids electric-gasoline vehicles, semi-static and mobile electrical units, and the like). This electrical energy is converted and appropriately processed for desired electrical characteristics from an energy/power source 110 (e.g., electrical grid, network AC line power, battery source, or the like) that sets a maximum charge rate for charging station 105 . The present invention is applicable to any charging station 105 , whether it uses a constant power, constant current, constant voltage, algorithmic charging curve, or other charging profile providing a range of charge rates and irrespective of the nature of power source 110 .
[0015] As noted above, charging station 105 may be used for many different systems and provide differing amounts of charging energy, whether it is a level 1, level 2, or level 3 charger, or other configuration not presently implemented, and the present invention may be adapted appropriately. To simplify the discussion and to aid in understanding aspects of the invention, a scenario is described in which charging station 105 includes a level 3 fast charger using electrical grid energy for power source 110 to charge an electric vehicle 115 .
[0016] Enhanced charging system 100 includes a station control 125 which oversees the charging and implements appropriate optimization profiles based upon actual needs of user 120 . A communications network 130 is shown interconnecting selected components of enhanced charging system 100 . Communications network 130 may be implemented in a wired mode, a wireless mode, or a combination of wired and wireless modes. There may be multiple different implementations of wired and wireless technologies all employed by enhanced charging system 100 , some of which are further explained below. Not all aspects of enhanced charging system 100 will include the same components or provide the same interconnections. Information and data flows between the interconnected selected components is appropriate to the degree and nature of the optimizations desired and implemented.
[0017] Enhanced charging system 100 additionally includes a user interface 135 and a generic function referred to herein as vehicle enhancement 140 . User interface 135 may be any appropriate input/output system enabling user 120 to either directly enter charge optimization data, a fast charging profile, or other explicit or inferred data from which an optimized charging profile for user 120 may be selected or constructed. User interface 135 may be integrated into and/or distributed over one or more of the other components of enhanced charging system 100 . Vehicle enhancement 140 includes features and systems that may be used in the building and implementation of a desired optimization profile.
[0018] For example, for some cell chemistries used in the energy storage system of certain high-performance electric vehicles 115 , frequent and extended uses of fast charging may adversely impact useful lifetime performance of the energy storage system. For some of these cell chemistries and charging implementations, some vehicle enhancement (e.g., environmental control of a system or component) of electric vehicle 115 will help counter some of the adverse effects of fast charging. One such environmental control is to ensure that the energy storage system is at an optimum temperature before initiation of the optimized charging profile being implemented. In such cases vehicle enhancement 140 includes a temperature control (typically a warmer) for the battery pack serving as the propulsion energy storage system of electric vehicle 115 . Other implementations may employ alternative or additional vehicle enhancement systems appropriate for those applications and design considerations.
[0019] Station control 125 collects available data from components of enhanced charging system 100 to establish an optimized charging profile that transfers charging energy/power from charging station 105 to electric vehicle 115 . This optimized charging profile may be dynamic or static and it may be explicitly set by user 120 (e.g., using user interface 135 ) or inferred from other available data. For the preferred implementation, the optimized charging profile primarily ensures that user 120 meets their needs for use of electric vehicle 115 . Secondarily other considerations may be optimized as long as these primary needs are satisfied.
[0020] The primary consideration is set by station control 125 determining when user 120 needs electric vehicle 115 to be available and what is the range requirement for electric vehicle 115 when user 120 expects to use electric vehicle 115 . There are many different ways station control 125 may establish or infer answers to these questions, the answers being used to build the charge optimization profile.
[0021] Typically, the answer to the optimization question to user 120 of “when do you need it and how far do you need to go?” is “it is needed as soon as possible and I need to go as far as possible.” This may be expressed in such general terms or in explicit state of charge (SOC) terms such as 80 miles range in one hour from now. In these cases, charging station 105 provides maximum available fast charge rate to meet the primary need of user 120 . However in other cases, the answer to the optimization question is something else and in these instances enhanced charging system 100 offers many advantages without interfering with satisfaction of primary considerations in the typical case.
[0022] In some cases, user 120 may not be aware or cognizant that less than a maximum fast charge will satisfy their current optimization question. The user may know that they need to be in City X three hours from now, but not realize that the necessary SOC for that range could be achieved with something other than a maximum fast charge. For situations when a “medium charge rate” scenario produces a valid charging profile that meets the user's primary needs, enhanced charging system 100 is then able to implement the charging profile optimized to include secondary considerations. These secondary considerations may be established by user 120 , set by an owner/operator of charging station 105 , or some combination. Some representative secondary considerations include a battery life conservation mode, an economical mode, a charger queue status (e.g., whether other customers are waiting to use the charger), a charger status, or other modes. Enabling station control 125 to factor in secondary considerations provides options that would not otherwise be available.
[0023] Enhanced charging system 100 is more intelligent and uses available resources more optimally. For example, when user 120 requests (explicitly or implicitly) 80% SOC two hours from the initiation of charging, station control 125 determines, for this particular charging use, an optimal combination of vehicle enhancement (e.g., pre-heating of the battery pack) and lower charge rate to meet the user primary need. This eliminates/minimizes any risk of possible battery life degradation due to this charging cycle. Alternatively, when the secondary consideration is a more economical mode, station control 125 could opt-out of using energy for battery pack pre-heating.
[0024] In some scenarios, it is possible that user 120 could be charged based upon some tiered pricing structure for use of high-performance charging (e.g., fee based upon charging measured in miles/minute or kWh/minute or the like). For charging scenarios where user 120 does not require the highest-priced charging rate, automatic use of a lower priced, slower charge rate advantages user 120 , particularly for an economical mode secondary consideration. Implementations of the present invention may be adapted for different sets of secondary considerations.
[0025] The more data that is available to station control 125 , the better enhanced charging system 100 is able to define and implement an appropriate optimization charging profile. Preferably station control 125 takes into account how much charge energy is currently stored in electric vehicle 115 and understands other charging parameters of enhanced charging system 100 to be able to estimate charge times and expected SOC levels accurately in order to meet the primary needs of user 120 . This data may be made available from on-vehicle sensors, on-vehicle management systems, or the like.
[0026] Station control 125 collects any available necessary or desirable data using communications network 130 to access charging station 105 , electric vehicle 115 , user 120 , and/or user interface 135 . Station control 125 may, in some implementations, not only obtain key charging parameters (e.g., current SOC) from electric vehicle 115 , but may access on-board or cloud-based electronic trip planning/navigation systems to automatically help establish answers to the optimization question (e.g., how far away is the next stop for user 120 and is there a scheduled time for departure/arrival). Station control 125 has access to the available data to formulate many different questions/responses that explicitly define, or allow intelligent inference of, an optimized charging profile that meets desired primary and selected secondary considerations.
[0027] The optimized charging profile may be static, dynamic, or some combination. A static profile is one that is set at the initiation of the charging cycle. It will stop when completed, or it may be interrupted, such as to terminate charging early or to redefine the charging profile. Enhanced charging system 100 enables dynamic charging profiles to be used as well. For example, user 120 may communicate with station control 125 periodically using communications network 130 (e.g., user 120 may employ a portable electronic device (e.g., smartphone or the like) operating a software process that communicates wirelessly with station control 125 and/or electric vehicle 115 ). Changes to the optimization question (e.g., lunch is running longer than anticipated and more time is available for charging or the destination is changed so less range is required) result in automatic adjustments to the optimization profile when communicated to station control 125 , such as by entering updated data from the portable electronic device carried by user 120 .
[0028] In some cases charging station 105 may be able to provide variable rate charging to multiple electric vehicles at the same time. Charging station 105 would be able to dynamically allocate different charging rates to different electric vehicles based upon an aggregation of priority and optimization questions of several users at one time. In some cases charging station 105 would not be able to provide all users with full fast charging at the same time and enhanced charging system 100 would dynamically apportion charging energy transfer rates among the several electric vehicles.
[0029] Enhanced charging system 100 offers additional options to the users of the several electric vehicles and to the owner/operator of charging station 105 . A simple priority system would have a first electric vehicle (vehicle A) arriving at charging station 105 first receive priority over a second electric vehicle (vehicle B) arriving later. However based upon optimization questions, it may be that vehicle B has need of a full fast charge and vehicle A could use a medium charge and still meet desired SOC and departure targets for both users. Enhanced charging system 100 is able to reallocate resources of charging station 105 to meet both user needs.
[0030] There are other options as well. In the case that all needs of all concurrent users of charging station 105 cannot be met, station control 125 may issue offers to first-in-time higher priority users requesting changes to their travel plans (e.g., delay departure by some predetermined time) in exchange for appropriate compensation. Station control 125 is able to intelligently make offers as it understands all current charging expectations and scheduled charge completion times. For example, user A may be offered a discount on her charging costs if she agrees to delay her departure 15 minutes to accommodate user B's need for a maximum fast charge. When agreed to, the users are notified of the new charging schedules, with both users satisfied of the outcome. In some implementations, concurrent users of charging station 105 may participate in a real-time auction for charging rate in cases where demand exceeds capacity. Thus enhanced charging system 100 may establish a dynamic price for different tiers of charging speed to accommodate users with urgent needs.
[0031] In some cases, it may meet overall optimization goals for charging station 105 to consider that a newer arrival may already have the battery pack at or near an optimum temperature for charging. Giving this user charging priority may help meet other implemented secondary considerations of enhanced charging system 100 . This may be advantageous as an earlier user's requirement for a pre-heating phase is not affected by delaying initiation of charging and thus will consume the same amount of energy for warming and charging irrespective of whether charging is performed “now” as opposed to “later.” As long as the user's primary needs are otherwise met, changing charging order or priority does not adversely impact the earlier user. In this scenario the overall energy used is less when considering energy consumption of both drivers than would be the case of charging performed based strictly on arrival order.
[0032] FIG. 2 illustrates a flowchart for an enhanced charging process 200 , such as may be implemented by enhanced charging system 100 shown in FIG. 1 . Process 200 includes steps 205 - 235 and begins at step 205 to collect data to answer some version of the optimization question to the user: “When do you need your electric vehicle to be ready and how far do you need to go?” Process 200 receives data from the electric vehicle and/or the user to explicitly answer this question, or may infer the answer from other available data, and sets this as the primary consideration. Based upon the collected data, process 200 next at step 210 establishes an answer to a first question of whether a maximum/fast charge is required to best meet the primary consideration. When the answer to that question is “YES” process 200 branches to step 215 to initiate the required fast charge. When the answer to the question of step 210 is “NO” then process 200 branches to step 220 to build an optimization profile that includes one or more secondary considerations. These secondary considerations may include an “economical” mode or a “best battery life” mode, a combination of these modes or some mode altogether different. The mode may be set or influenced by the user or owner/operator of the charging station. After the optimization profile is built at step 220 , process 200 advances to step 225 to initiate charging using the optimization profile which is likely to be, but not necessarily, different from the maximum fast charge of step 215 .
[0033] After both step 215 and step 225 , process 200 makes a second test at step 230 to determine whether there have been any changes that could affect the charging rate currently being applied (i.e., a change to the primary or secondary considerations used by process 200 ). These changes may be explicit changes or may be implicit in other factors affecting enhanced charging system 100 . Explicit changes include an express change to departure time or destination that is communicated to station control 125 . Implicit changes include secondary factors that implicate changes to the departure time or destination, affect charge rate, and/or affect vehicle enhancement. For example, before charging is actually initiated using an existing optimization profile, temperature data currently indicates that there are now benefits to pre-heating the energy storage system when there had been no previous advantage to pre-heating during a previous test (e.g., the energy storage system has cooled). When there are no changes at step 230 , process 200 implements step 235 and continues charging as determined by step 215 or step 225 . Process 200 continues to loop from step 235 to the test at step 230 while charging in case important changes are made or detected.
[0034] When the test at step 230 indicates that there are changes that could affect the answer to the optimization question, process 200 returns to step 205 to collect new data as necessary or appropriate. Process 200 continues until charging is terminated.
[0035] The system and methods above has been described in general terms as an aid to understanding details of preferred embodiments of the present invention. In the description herein, numerous specific details are provided, such as examples of components and/or methods, to provide a thorough understanding of embodiments of the present invention. It is anticipated that many implementations of the present invention include fast level 3 chargers for electric vehicles, such as incorporated into public charging stations. The present invention may be implemented in other contexts as well. One of the many advantages of the disclosed implementations of the present invention is that the user is not always tasked with understanding the many nuances and most current subtleties in implementing effective charging profiles to meet secondary considerations. As noted, there are nuances to building and implementing an effective charging profile to optimally enhancing battery life for any particular energy storage system. By using the systems and methods disclosed herein, the user does not need to learn and understand these evolving nuances. The user may be goal focused, and the systems and methods may optimally implement the charging profile(s) that best meet those goals. As the nuances evolve, the systems and methods are easily upgraded to implement the appropriate requirements, all without detailed involvement from the users. One or more components of the system and method are implemented using microprocessors executing instructions accessed from memory, these instructions available in software or firmware.
[0036] Some features and benefits of the present invention are realized in such modes and are not required in every case. One skilled in the relevant art will recognize, however, that an embodiment of the invention can be practiced without one or more of the specific details, or with other apparatus, systems, assemblies, methods, components, materials, parts, and/or the like. In other instances, well-known structures, materials, or operations are not specifically shown or described in detail to avoid obscuring aspects of embodiments of the present invention.
[0037] Reference throughout this specification to “one embodiment”, “an embodiment”, or “a specific 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 and not necessarily in all embodiments. Thus, respective appearances of the phrases “in one embodiment”, “in an embodiment”, or “in a specific embodiment” in various places throughout this specification are not necessarily referring to the same embodiment. Furthermore, the particular features, structures, or characteristics of any specific embodiment of the present invention may be combined in any suitable manner with one or more other embodiments. It is to be understood that other variations and modifications of the embodiments of the present invention described and illustrated herein are possible in light of the teachings herein and are to be considered as part of the spirit and scope of the present invention.
[0038] It will also be appreciated that one or more of the elements depicted in the drawings/figures can also be implemented in a more separated or integrated manner, or even removed or rendered as inoperable in certain cases, as is useful in accordance with a particular application.
[0039] Additionally, any signal arrows in the drawings/Figures should be considered only as exemplary, and not limiting, unless otherwise specifically noted. Furthermore, the term “or” as used herein is generally intended to mean “and/or” unless otherwise indicated. Combinations of components or steps will also be considered as being noted, where terminology is foreseen as rendering the ability to separate or combine is unclear.
[0040] As used in the description herein and throughout the claims that follow, “a”, “an”, and “the” includes plural references unless the context clearly dictates otherwise. Also, as used in the description herein and throughout the claims that follow, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise.
[0041] The foregoing description of illustrated embodiments of the present invention, including what is described in the Abstract, is not intended to be exhaustive or to limit the invention to the precise forms disclosed herein. While specific embodiments of, and examples for, the invention are described herein for illustrative purposes only, various equivalent modifications are possible within the spirit and scope of the present invention, as those skilled in the relevant art will recognize and appreciate. As indicated, these modifications may be made to the present invention in light of the foregoing description of illustrated embodiments of the present invention and are to be included within the spirit and scope of the present invention.
[0042] Thus, while the present invention has been described herein with reference to particular embodiments thereof, a latitude of modification, various changes and substitutions are intended in the foregoing disclosures, and it will be appreciated that in some instances some features of embodiments of the invention will be employed without a corresponding use of other features without departing from the scope and spirit of the invention as set forth. Therefore, many modifications may be made to adapt a particular situation or material to the essential scope and spirit of the present invention. It is intended that the invention not be limited to the particular terms used in following claims and/or to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include any and all embodiments and equivalents falling within the scope of the appended claims. Thus, the scope of the invention is to be determined solely by the appended claims.
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An electric charging system for a battery pack of an electric vehicle, including a charging station electrically coupled to the battery pack, the charging station transferring charging energy to the battery pack at a maximum fast charge rate in a first operational mode and transferring charging energy to the battery pack at a slower charge rate in a second operational mode; a data collection system acquiring a set of data indicating a state of charge (SOC) of the battery pack and one or more desired charge optimization parameters; and a station control, responsive to the set of data and to the desired charge optimization parameters, automatically establishing a charging profile for the battery pack to assert a control signal and operate the charging station in the second operational mode whenever the charging station is able to transfer sufficient energy to the battery pack at the slower charge rate to meet an SOC target and a charge completion time target, otherwise asserting the control signal and operate the charging station in the first operational mode.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a Continuation of and claims priority under 35 U.S.C. §120 from parent application U.S. patent application Ser. No. 12/473,645 filed May 28, 2009, which in turn claims priority under 35 U.S.C. §119 from Chinese Patent Application No. 200810108872.4 filed on May 29, 2008, the entire contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention is related to a communication base station, and in particular to a radio frequency communication base station adaptive for antenna arrays, a transceiving apparatus, a data processing system, and methods of receiving and sending data for the base station.
[0004] 2. Description of Related Art
[0005] Requirements for the next generation mobile communication system have increased when compared to today's communication system. The next generation mobile communication system must be able to provide a larger variety of interactive multimedia services, such as movies, games, television broadcasts, on-line transactions and voice services, with high speed and high quality via the converged network of wired and wireless infrastructures. Such various multimedia and data services require a communications base station not only with high throughput, but also with high computation capability to handle large numbers of streams or packets simultaneously. At the same time, the base station needs to be consistent with multiple standards, and to meet the requirements of various application services. Therefore, high computation capability and enough flexibility and scalability are the trend and the challenge for communications base stations for the next generation mobile system.
[0006] FIG. 1 shows the architecture of today's base station. As shown in FIG. 1 , the base-band processing system of the traditional base station includes a variety of proprietary designs implemented by semiconductor hardware in the form of a DSP (digital signal processor), a FPGA (field-programmable gate array), and an ASIC (application-specific integrated circuit), which result in different platforms serving for different standards, such as GSM (Global System for Mobile communications) and WCDMA (Wideband Code Division Multiple Access), allowing no flexibility and scalability of the whole system. In FIG. 1 , the PHY layer is the physical layer, the MAC layer is the Media Access Control Layer. Even within one standard, to support different coverage and application features, the hardware platforms must also be different. In order to meet different standards and accommodate other different application characteristics, in most cases, proprietary chips of different models or quantities are required, thus necessitating the redesigning and redeveloping of the hardware platform and resulting in a high cost of time and expense. Hence, in a base station based on proprietary hardware design, the development and management cost for both hardware and software will be heavy for operators as well as for telecom equipment manufacturers.
[0007] Considering these issues for base stations built on traditional architecture, the idea of open architecture based base stations has been proposed in recent years. Under the implementation and popularization of multi-core technology, the computation performance of IT computing platforms based on general purpose multi-core processors is being increased rapidly. So as to pursue better flexibility and scalability, the industry has started to consider adopting general IT computing platforms in networking areas, thus replacing the traditional proprietary design, especially for base stations in mobile communications. Accordingly, there are some new implementations using IT servers in base station design. They can use the servers to support different kinds of standards, e.g., GSM, CDMA, and use the servers to support different numbers of sectors or cells.
[0008] From another point of view, the concept of an antenna array (a group of antenna elements) with a base station is widely used in the new generation wireless standards, e.g., 802.11n of the 802.11 series, 802.16e, TD-SCDMA (Time Division-Synchronous Code Division Multiple Access), and LTE (Long Term Evolution). The size of the array will highly influence the throughput, coverage and system SNR (signal-to-noise ratio) of the base station. For instance, to cover a micro cell, a 2-element antenna array may be enough, but for a macro cell, a 4-element antenna array will be required. Further, different algorithms will require different numbers of antenna elements in the array. For example, 802.11n applying MIMO (multiple-input and multiple-output) technology will require an antenna array with 2 or 4 elements, while TD-SCDMA (Time Division-Synchronous Code Division Multiple Access) using smart antenna techniques will need an array with at least 8 elements.
[0009] For traditional base station architecture composed of proprietary designs, when the size of the antenna array changes, the base band processing platform must be re-designed to accompany the changes of the antenna array. FIG. 2 illustrates the changes carried out to a base band processing platform of a traditional base station accompanying an increase in size of the antenna array. As shown in FIG. 2( a ), the antenna array includes two antennas, the first antenna connected to board 0 and the second antenna connected to board 1 . Accordingly, sub-channel processing hardware modules are needed in the base band processing platform corresponding to the uplink and downlink data of each antenna, i.e., an uplink sub-channel hardware module 0 to process the uplink data of the first antenna, an uplink sub-channel hardware module 1 to process the uplink data of the second antenna, a downlink sub-channel hardware module 0 to process the downlink data of the first antenna, and a downlink sub-channel hardware module 1 to process the downlink data of the second antenna. Furthermore, an uplink central processing hardware module and a downlink central processing hardware module are needed in the base band processing platform for the central main processing of uplink data and downlink data, respectively.
[0010] As shown in FIG. 2( b ), when the antenna array includes eight antennas, i.e., antenna 0 to 7 , not all shown, changes of the base band processing platform in hardware design must be carried out with respect to the increase in the number of antennas. Specifically, uplink sub-channel hardware modules and downlink sub-channel hardware modules, i.e., uplink sub-channel hardware modules 2 to 7 and downlink sub-channel hardware modules 2 to 7 need to be added to the base band processing platform for antennas 2 to 7 . Then, the data of the added sub-channel hardware modules need to be collected into the central line boards for processing. Thus, it can be seen that for antenna arrays of different sizes, the base band processing platform needs to be re-designed and changed to correspond to the changes in the antenna arrays.
[0011] Therefore, to fulfill the required flexibility and scalability in base band processing of base stations, it will be required that the base band processing system must be able to be scaled and to have the flexibility for different sizes of antenna arrays. However, with respect to the traditional base station with proprietary architecture design, or with respect to new base station designs based on general IT servers, the scalability of antenna arrays cannot be supported using today's technology.
SUMMARY OF THE INVENTION
[0012] In order to improve the flexibility and scalability of the base band processing systems of base stations, there are provided: a base station adaptive for antenna arrays, a radio frequency header module, a transceiving apparatus, and a data processing system for the base station, and methods of receiving and sending data for the base station.
[0013] According to an aspect of the present invention, there is provided a base station apparatus adaptive for antenna arrays. The base station includes:
[0014] at least one radio frequency (RF) header module;
[0015] at least one data processing apparatus; and
[0016] transceiving apparatus for transceiving data between the at least one radio frequency (RF) header module and the at least one data processing apparatus; The transceiving apparatus includes:
an uplink module to group data received by the at least one RF header module according to grouping configuration information, and transfer the grouped data to the at least one data processing apparatus; and a downlink module to degroup the data from the at least one data processing apparatus according to the grouping configuration information, and transfer the degrouped data to the at least one RF header module.
The at least one data processing apparatus includes:
at least one uplink sub-channel processing module to process the uplink data of one sub-channel; a data distributor to distribute grouped data to the at least one uplink sub-channel processing module; at least one downlink sub-channel processing module to process the downlink data of one sub-channel; and a data converger to merge the data from each of the at least one downlink sub-channel processing modules.
The at least one radio frequency (RF) header module includes:
at least one antenna and RF channel corresponding to the antenna.
[0024] According to another aspect of the present invention, there is provided a method of receiving and sending data, the method including the steps of:
[0025] receiving the data by an at least one radio frequency (RF) header module;
[0026] grouping the data received by the at least one radio frequency (RF) header module according to grouping configuration information;
[0027] transferring the grouped received data to at least one data processing apparatus;
[0028] distributing the grouped received data in each of the at least one data processing apparatus into at least one uplink sub-channel according to the data channel from which the data is received;
[0029] merging the distributed data in each of the at least one data processing apparatus using at least one downlink sub-channel;
[0030] transferring the merged data from the at least one data processing apparatus to a transceiving apparatus;
[0031] degrouping the merged data from the at least one data processing apparatus according to the grouping configuration information; and
[0032] sending the merged data by the at least one radio frequency (RF) header module,
[0033] where at least one step is carried out using a computer device.
[0034] According to still another aspect of the present invention, there is provided a method of receiving data for a base station. The method includes:
[0035] receiving the data by an at least one radio frequency (RF) header module;
[0036] grouping the data received by at least one radio frequency (RF) header module according to grouping configuration information;
[0037] transferring the grouped data to at least one data processing apparatus; and
[0038] distributing the grouped data in each of the at least one data processing apparatus into at least one uplink sub-channel according to the data channel from which the data is received.
[0039] According to still another aspect of the present invention, there is provided a method of sending data for a base station. The method includes:
[0040] merging the data of at least one downlink sub-channel in each of at least one data processing apparatus;
[0041] transferring the merged data from the at least one data processing apparatus to a transceiving apparatus;
[0042] degrouping the merged data from the at least one data processing apparatus according to grouping configuration information; and
[0043] sending the merged data by an at least one radio frequency (RF) header module.
[0044] According to still another aspect of the present invention, there is provided a computer readable article of manufacture tangibly embodying computer readable instructions for executing a computer implemented method of sending data for a base station. The method includes:
[0045] merging the data of at least one downlink sub-channel in each of at least one data processing apparatus;
[0046] transferring the merged data from the at least one data processing apparatus to a transceiving apparatus;
[0047] degrouping the merged data from the at least one data processing apparatus according to grouping configuration information;
[0048] sending the merged data by an at least one radio frequency (RF) header module.
[0049] In each aspect of the present invention, by grouping the data from antenna arrays according to the grouping configuration information, transmitting the grouped data to the corresponding processing apparatus, and distributing the data into corresponding sub-channels for processing, the base band processing system can be adaptive for antenna arrays with different sizes and different standards, thus remarkably improving the flexibility of the base station processing system.
BRIEF DESCRIPTION OF THE DRAWINGS
[0050] FIG. 1 illustrates the architecture of an existing communication base station;
[0051] FIG. 2 illustrates the modifications to a base band processing platform of a traditional base station performed according to an increase in the size of antenna arrays;
[0052] FIG. 3 illustrates the architecture of a communication base station according to an embodiment of the present invention;
[0053] FIG. 4 illustrates the structure of the transceiving apparatus 20 of FIG. 3 ;
[0054] FIG. 5 illustrates the architecture of a communication base station according to another embodiment of the present invention;
[0055] FIG. 6 illustrates the architecture of a communication base station according to yet another embodiment of the present invention;
[0056] FIG. 7 illustrates the flow chart of a method of receiving data for a base station according to an embodiment of the present invention; and
[0057] FIG. 8 illustrates the flow chart of a method of sending data for a base station according to an embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0058] Various embodiments of the present invention are described below in combination with the figures.
[0059] FIG. 3 illustrates the architecture of a base station according to an embodiment of the present invention. As shown in the figure, the base station of FIG. 3 includes an RF header system 10 , a transceiving apparatus 20 , a switch module 40 and a data processing system 30 . In the base station, the RF header system 10 is provided to receive uplink data signal from communication terminals and transmit the data to the transceiving apparatus 20 ; and to acquire processed downlink data from the transceiving apparatus 20 and transmit the data to the communication terminals. The transceiving apparatus 20 is linked between the RF header system 10 and the data processing system 30 , to acquire uplink data from the RF header system 10 , group the uplink data according to grouping configuration information and transmit the grouped data to the data processing system 30 ; and to acquire processed downlink data from the data processing system 30 , and degroup the downlink data and transmit the degrouped data to the RF header system 10 . The switch module 40 is provided to switch data between the transceiving apparatus 20 and the data processing system 30 and inside the data processing system 30 . The data processing system 30 is provided to perform base band processing to the uplink data acquired from the transceiving apparatus 20 according to the grouping configuration information, and to transmit the processed downlink data to the transceiving apparatus 20 after the base band processing.
[0060] In the present embodiment, the RF header system 10 includes 8 RF header modules, marked by 0 to 7 . Only antennas 0 and 7 are shown. Each RF header module includes an antenna and a data channel corresponding to the antenna. Specifically, the RF header module 0 includes the antenna 0 and an uplink analog channel and a downlink analog channel corresponding to the antenna. The uplink analog channel includes an RF/IF module that converts the RF radio frequency signals received from the antenna into IF intermediate frequency signals, and an analog-to-digital converter ND that converts analog signals into digital signals. The downlink analog channel includes a digital-to-analog converter D/A that converts digital signals into analog signals, and an RF/IF module that converts intermediate frequency analog signals into radio frequency signals to be sent through antennas. Other RF header modules 1 to 7 include respective antennas 1 to 7 and corresponding analog channels. The number of antennas can be adjusted according to requirements, e.g., m antennas 0 to m−1 can be set.
[0061] FIG. 4 illustrates the structure of the transceiving apparatus 20 of FIG. 3 . As shown in the figure, the transceiving apparatus 20 includes an uplink module 210 and a downlink module 220 , where the uplink module 210 is provided to acquire uplink data from the RF header system 10 , group the uplink data according to the grouping configuration information, and transmit the grouped data to the data processing system 30 ; the downlink module 220 is provided to acquire processed downlink data from the data processing system 30 , degroup the downlink data, and transmit the degrouped data to the RF header system 10 .
[0000] The uplink module 210 further includes an uplink data queue module 212 , a data grouper 214 and a frame generator 216 .
[0062] The uplink data queue module 212 includes a plurality of uplink data queues Q 0 , Q 1 , to Q 7 , where the number of queues corresponds to the number of data channels of incoming data. In the present embodiment, the number of uplink data queues corresponds to the number of data channels in the RF header system, i.e., the number of antennas. Since the antennas receive RF signals in real time from the terminals, the signals need to be buffered first in order to be processed. These data queues corresponding to the data channels provide buffering for the data in the corresponding channels. Specifically, the data queues can be implemented through the memory cells in the transceiving apparatus. The number of the queues and the memory they take can be preset in the transceiving apparatus, or can be automatically set or changed through external grouping configuration information, where the external grouping configuration information can come from the data processing system 30 .
[0063] The data grouper 214 is provided as a hardware module in the transceiving apparatus to group the incoming data. Specifically, in this embodiment the data grouper 214 groups the incoming data from each data queues Q 0 to Q 7 according to the grouping configuration information which relies on the needed computation resource and the available resource of each processing apparatus in the data processing system 30 , the needed computation resource in turn relies on the number of antennas and the algorithms used. In one embodiment, the grouping configuration information is manually set and input to the transceiving apparatus. In another embodiment, the grouping configuration information is automatically generated by the data processing system 30 , and dynamically input to the transceiving apparatus. Further, the data grouper 214 adds synchronization flags into each grouped data stream, and adds path ID into the stream according to the corresponding data channel through which it flows, for the identification of the data of each data channel in future processing. In the embodiment shown in FIG. 3 , the data grouper 214 groups the data from Q 0 to Q 7 into two groups according to the grouping configuration information from the data processing system 30 , with one group containing data from Q 0 to Q 5 , and the other group containing data from Q 6 and Q 7 . Specifically, grouping labels can be added into the grouped data. For example, label G 1 is added into the data in queues Q 0 to Q 5 , showing that they belong to the first group; label G 2 is added into the data in queues Q 6 and Q 7 , showing that they belong to the second group. The grouping conditions can be different according to the differences in the data queues and in the grouping configuration information.
[0064] Further, the grouped data flows into the frame generator 216 . As another configurable hardware module in the transceiving apparatus 20 , the frame generator 216 is provided for encapsulating every group of incoming data. Specifically, the frame generator 216 encapsulates every group of data from the data grouper 214 into the frame conforming to a standard, e.g., Ethernet, InfiniBand, so that they can be received and processed by a universal processing apparatus through the switch module 40 .
[0065] The downlink module 220 further includes a data extractor 226 , a data de-grouper 224 and a downlink data queue module 222 . The data extractor 226 performs the reverse of the frame generator 216 in the uplink module 210 . It deencapsulates the frames of data and extracts the grouped data. Specifically, the data extractor 226 deencapsulates the frames of the data coming from the data processing system through the switch module 40 , according to the applied standard, e.g., Ethernet, InfiniBand, and extracts grouped data from them.
[0066] Data de-grouper 224 performs the reverse of the data grouper 216 in the uplink module. It de-groups the downlink data according to the grouping of the uplink data by data grouper 214 . Specifically, the data de-grouper 224 receives downlink data from the data extractor 226 , synchronizes each group of data according to the synchronization flags of each group of data, and distributes the data into outgoing queues according to the path IDs marked in the data stream.
[0067] The downlink data queue module 222 includes a plurality of downlink data queues Q 0 , Q 1 to Q 7 , with the number of queues corresponding to the number of data channels, i.e., the number of antennas. These downlink data queues act as buffers for the data in corresponding channels in order to send the data to the RF header system. Corresponding to the uplink queues, the number of downlink queues and the memory they take can be manually preset in the transceiving apparatus, or can be automatically set and changed according to the grouping configuration information.
[0068] In order to realize the functions of the above the modules, the transceiving apparatus 20 can be implemented with programmable chipsets, e.g., a digital signal processor (DSP), a field-programmable gate array (FPGA), or an application-specific integrated circuit (ASIC). The modules in the transceiving apparatus 20 can be implemented with independent or integrated chips in the programmable chipset.
[0069] Returning to FIG. 3 , the switch module 40 is linked between the transceiving apparatus 20 and the data processing system 30 for switching data between the transceiving apparatus 20 and the data processing system 30 and inside the data processing system 30 . Specifically, for uplink data, the switch module 40 maps each group of data into its corresponding processing apparatus in the data processing system 30 according to the data grouping conditions by the transceiving apparatus 20 . In this embodiment, the transceiving apparatus 20 groups the uplink data into two groups. The switch module 40 routes the first group of data to the first processing apparatus 310 in the data processing system 30 , and routes the second group of data to the other processing apparatus 320 .
[0070] For downlink data, the switch module 40 converges, or merges, the downlink data coming from different processing apparatus and transmits the data to the transceiving apparatus 20 . Further, the switch module 40 also switches data between different processing apparatuses in the data processing system 30 when data transmission and switching between them is needed. Data communication between the switch module 40 and the data processing system 30 can be implemented through various protocols and standards, e.g., Ethernet or InfiniBand.
[0071] After acquiring uplink data from the transceiving apparatus 20 through the switch module 40 , the data processing system 30 carries out base band processing of the acquired uplink data according to the grouping configuration information, and transmits the downlink data after base band processing to the transceiving apparatus 20 through the switch module 40 . As shown in the figure, the data processing system 30 includes multiple data processing apparatus, i.e., processing apparatus 310 , 320 , 330 and 340 . Each processing apparatus is a universal processing apparatus that can be independent, possibly using independently running line boards, PCs or servers, or can be implemented by at least one blade in a blade server, as long as the processing apparatus can independently carry out universal computations and can interconnect to carry out collaborated computation.
[0072] The processing apparatus 310 includes a data distributer 312 and a plurality of uplink sub-channel processing modules UP 0 to UP 5 . The data distributer 312 receives stream data from the transceiving apparatus 20 through the switch module 40 , and distributes the data into corresponding uplink sub-channel processing modules according to the path IDs of the stream data. In the present embodiment, the data distributer 312 receives the data corresponding to antennas 0 to 5 and further corresponding to queues Q 0 to Q 5 from the transceiving apparatus 20 through the switch module 40 , and distributes the data into uplink sub-channel processing modules UP 0 to UP 5 according to the path IDs of the data. The uplink sub-channel processing modules UP 0 to UP 5 are provided to perform sub-channel processing for the uplink data in each sub-channel. In the present embodiment, the processing performed in uplink sub-channel processing modules is related to the standards, algorithms, and other characteristics used by the system, e.g., synchronization processing, or Orthogonal Frequency-Division Multiple Access (OFDMA) processing.
[0073] The processing apparatus 320 includes a data distributer 322 , uplink sub-channel processing modules UP 6 to UP 7 , and an uplink main processing module UMP. The data distributer 322 receives the data corresponding to antennas 6 and 7 , and further corresponding to queues Q 6 and Q 7 from the transceiving apparatus 20 through the switch module 40 , and distributes the data into corresponding uplink sub-channel processing modules UP 6 and UP 7 according to the path IDs of the data. The uplink sub-channel processing module UP 6 and UP 7 perform sub-channel processing for the uplink data distributed to them. The uplink main processing module UMP is provided to perform main processing for the uplink data. In the present embodiment, the data coming from the uplink sub-channel processing modules UP 0 to UP 5 in the processing apparatus 310 is transmitted into the processing apparatus 320 through the switch module 40 , and flows into the main processing module UMP together with the data from the uplink sub-channel processing module UP 6 and UP 7 for uplink main processing which includes spatial filtering, STBC, space-time block coding, channel estimation, demodulation and decoding.
[0074] Similarly, the processing apparatus 330 includes a data converger 332 and downlink sub-channel processing modules DP 0 to DP 5 . The downlink sub-channel processing modules DP 0 to DP 5 perform downlink sub-channel processing for the downlink data, including OFDMA, Orthogonal Frequency-Division Multiple Access, and shaping filtering. The data converger 332 is provided to converge, or merge, the data in each of the downlink sub-channel processing modules DP 0 to DP 5 , and transmit the data to the transceiving apparatus 20 through the switch module 40 .
[0075] The processing apparatus 340 includes a data converger 342 , downlink sub-channel processing modules DP 6 and DP 7 , and a downlink main processing module DMP. The data converger 342 is provided to converge the data processed by the downlink sub-channel processing modules DP 6 and DP 7 . The downlink main processing module DMP is provided to perform downlink main processing on the downlink data. The downlink main processing includes beamforming, modulation and coding. In the present embodiment, the downlink main processing module DMP performs downlink main processing for data in all the data channels. Then, the data in two of the data channels are treated with downlink sub-channel processing in the downlink sub-channel processing modules DP 6 and DP 7 in the processing apparatus 340 , converged by the data converger 342 and transmitted to the transceiving apparatus 20 through the switch module 40 . The data in the other data channels are transmitted to the processing apparatus 330 through the switch module 40 , treated with downlink sub-channel processing in the downlink sub-channels processing modules DP 0 to DP 5 of the processing apparatus 330 , converged by the data converger 332 and then transmitted to the transceiving apparatus 20 through the switch module 40 .
[0076] The data distributers, data convergers, uplink sub-channel processing modules, downlink sub-channel processing modules, uplink main processing module and downlink main processing module are all implemented by the software modules in the processing apparatus.
[0077] It can be seen that the distribution of the uplink and downlink sub-channel processing modules among different processing apparatus corresponds to the grouping of data by the transceiving apparatus 20 . Specifically, the transceiving apparatus 20 groups the data queues Q 0 to Q 7 into two groups according to the grouping configuration information; data in Q 0 to Q 5 is in the first group, and data in Q 6 and Q 7 is in the second group. The data in the first group are transmitted to the processing apparatus 310 and processed with uplink sub-channel processing in the corresponding uplink sub-channel processing modules UP 0 to UP 5 . The data in the second group are transmitted to the processing apparatus 320 , and respectively treated with sub-channel processing in the corresponding sub-channel processing modules UP 6 and UP 7 .
[0078] Similarly, the downlink data are also grouped into two groups, each being treated with sub-channel processing in corresponding downlink sub-channel processing modules in processing apparatuses 330 and 340 . Thus, it can be seen that the distribution of uplink and downlink sub-channel processing modules corresponds to the grouping of data, and further relies on the grouping configuration information.
[0079] As described above, the grouping configuration information relies on the computation resource needed and the available resource of each processing apparatus in the data processing system 30 ; the computation resource needed further relies on the number of antennas and algorithms. In one embodiment, the grouping configuration information is preset, i.e., the grouping to be performed and the loading of corresponding software modules in the processing apparatus according to the grouping are decided in advance. In another embodiment, the grouping configuration information is computed by an external computation apparatus, not shown, according to the resource needed and the available resource of each processing apparatus, and is transmitted to the transceiving apparatus 20 and the data processing system 30 .
[0080] In the embodiment shown in the figure, the grouping configuration information is automatically generated by the data processing system 30 , and dynamically input to the transceiving apparatus 20 . At the same time, the sub-channel processing modules in the data processing system 30 are also distributed and configured through the grouping configuration information.
[0081] In the present embodiment, the processing apparatus 310 further includes a configure manager 315 . The configure manager 315 is implemented by software modules to generate the grouping configuration information, and to generate, configure, and manage other modules in the processing apparatus. Specifically, the configure manager 315 includes a resource estimator 50 , a module generator 52 and a module reconfigurer 54 . The resource estimator 50 is provided to estimate the needed computation resource and the available resource in each processing apparatus, and to accordingly generate the grouping configuration information. The module generator 52 is provided to generate needed modules in the processing apparatus according to the grouping configuration information generated by the resource estimator 50 . The module reconfigurer, or module configure, 54 is provided to configure the parameters of the modules in the processing apparatus. Other processing apparatus 320 , 330 , 340 each include their configure managers 325 , 335 and 345 , respectively. When the data processing system 30 includes a plurality of configure managers, one of them, e.g., the configure manager 315 can be set as the main configure manager.
[0082] Specifically, in the present embodiment, the resource estimator 50 in the configure manager 315 estimates the computation resource needed for processing the data transmitted by the antennas according to the number of antennas, i.e., antennas 0 to 7 , and the standards and algorithms the antennas are based on, and estimates the available computation resource in each processing apparatus according to the performance, resource occupation status and the like of the processing apparatus. Based on the estimation of the needed and available resource, it is found that in the case of the present embodiment, both the uplink and downlink data need to be divided into two groups. The data corresponding to antennas 0 to 5 is in one group, and the data corresponding to antennas 6 and 7 is in the other group. The two groups of uplink data and two groups of downlink data need to be processed respectively in four processing apparatus. Such grouping configuration information is transmitted to the transceiving apparatus 20 as its basis for grouping the data.
[0083] According to the grouping configuration information, the module generator 52 generates uplink sub-channel processing modules UP 0 to UP 5 in the processing apparatus 310 corresponding to the first group of uplink data, and generates a data distributer 312 to distribute the uplink data into these uplink sub-channel processing modules. The main configure manager 315 informs other configure managers 325 , 335 , and 345 of the configure management information, enabling the module generators in these configure managers to generate needed modules in their respective processing apparatus according to the configure management information. The communication between the configure managers can be implemented through various protocols and interfaces, e.g., Ethernet interface protocol, CPU BUS interface, and PCI interface.
[0084] The module reconfigurer 54 is provided to configure the parameters of the generated modules. Specifically, in the uplink and downlink main processing modules, many algorithms and parameters, e.g., special filter and beamforming algorithms for smart antennas, STBC coding algorithm for MIMO antennas, are sensitive to the size of antenna arrays. Consequently, the parameters and data structure of these algorithms related to the antenna arrays should be configured according to the information of the antennas in the RF header system.
[0085] As can be seen from the descriptions above, by using the configure manager, it is possible to automatically calculate the needed resource and available resource and thus acquire the grouping configuration information, and to generate the needed modules in each of the processing apparatus according to the grouping configuration information. It is thereby possible to achieve a proper distribution and configuration of the modules among the processing apparatus and to further improve the flexibility of the system.
[0086] In the base station shown in FIG. 3 , the transceiving apparatus 20 is placed between the RF header system 10 and the data processing system 30 as an independent hardware component. However, the transceiving apparatus 20 can also be integrated into the RF header system to act as a new RF header system. Or the transceiving apparatus 20 can be integrated into the data processing system to act as a new data processing system. Also, the switch module 40 can also be integrated with the transceiving apparatus 20 .
[0087] FIG. 5 illustrates the architecture of a base station according to another embodiment of the present invention. In FIG. 5 , the modules and apparatus similar to those in FIG. 3 are indicated by the same numbers. As shown in FIG. 5 , the base station includes an RF header system 10 , a transceiving apparatus 20 , and a data processing system 30 . Among them, the RF header system includes 4 antennas marked by 0 to 3 and the corresponding data channels. The transceiving apparatus 20 is identical with that in FIG. 4 . However, according to the grouping configuration information, the transceiving apparatus 20 groups the incoming data into only one group, i.e., the data in all the data channels are transmitted into the same processing apparatus or processor 310 , in the data processing system 30 . The data processing system 30 uses only one processing apparatus 310 to perform base band processing.
[0088] The processing apparatus 310 includes a data distributer 312 , uplink sub-channel processing modules UP 0 to UP 3 , an uplink main processing module UMP, a data converger 314 , downlink sub-channel processing modules DP 0 to DP 3 , and a downlink main processing module DMP. The functions of these modules are the same as those of the corresponding modules in FIG. 3 , but in the present embodiment, according to the grouping configuration information, they are allocated into the same processing apparatus 310 . As described above, the grouping configuration information can be preset, externally computed, or automatically generated by the data processing system. In the present embodiment, the grouping configuration information is generated by the configure manager 315 in the processing apparatus 310 . The configure manager 315 is the same as that in FIG. 3 in structure, function, and implementation.
[0089] When only one processing apparatus is employed, the switch module 40 in FIG. 3 is not needed for data switching. The transceiving apparatus 20 directly communicates with the processing apparatus 310 in the data processing system.
[0090] FIG. 6 illustrates the architecture of a base station according to another embodiment of the present invention. This base station also includes an RF header system 10 , a transceiving apparatus 20 and a data processing system 30 . Among them, the RF header system 10 includes 4 antennas, where the antennas 0 and 1 belong to array 1 , supporting Worldwide Interoperability for Microwave Access (WiMax); and antennas 2 and 3 belong to array 2 , supporting the Long Term Evolution (LTE) standard. For such multiple communication standards or multi-standard antenna arrays, when the transceiving apparatus 20 performs grouping of the data in each data channel according to the grouping configuration information, not only does it need to add channel ID (or path ID) to the data channels, but it also needs to add the ID of the antenna array from which the data comes. In the present embodiment, according to the grouping configuration information, data in all the data channels are put into one group, and processed by a single processing apparatus, similar to processor 310 of FIG. 5 , in the data processing system 30 .
[0091] In order to accommodate multi-standard antenna arrays, according to the grouping configuration information, the processing apparatus includes a data distributer 312 , uplink sub-channel processing modules UP 0 to UP 3 , uplink main processing modules UMP 1 and UMP 2 , a data converger 314 , downlink sub-channel processing modules DP 0 to DP 3 , and downlink main processing modules DMP 2 and DMP 2 . Among them, the uplink sub-channel processing modules UP 0 and UP 1 are provided to perform uplink sub-channel processing for WiMax for the data from antennas 0 and 1 , and UP 2 and UP 3 are provided to perform uplink sub-channel processing for LTE for the data from antennas 2 and 3 . According to the array IDs marked in the data sub-channels, the data after uplink sub-channel processing flow respectively into the uplink main processing modules UMP 1 and UMP 2 for main processing. The uplink main processing module UMP 1 is configured to execute the uplink main processing for WiMax, and the uplink main processing module UMP 2 is configured to execute the uplink main processing for LTE. The downlink sub-channel processing modules DP 0 to DP 3 and the downlink main processing modules DMP 1 and DMP 2 are configured corresponding to the uplink processing configurations.
[0092] Further, in the present embodiment, the grouping configuration information can also be generated by the configure manager 315 in the processing apparatus. The structure, function and implementation of the configure manager 315 are similar to those described above.
[0093] It can be seen from the embodiments described above that, through the grouping of the data from antenna arrays according to the grouping configuration information, transmitting the grouped data to the corresponding processing apparatuses, and distributing the data to the corresponding sub-channels for processing, the base band processing system can be adaptive for antenna arrays with different sizes and executing different standards, without re-designing the hardware. Instead, the base band processing system only needs to distribute and configure the needed software modules according to the grouping configuration information. By setting the configure manager in the processing system, the base band processing system can automatically generate the grouping configuration information, and thus more flexibly accommodate the changes in antenna arrays. Those skilled in the art can understand that the embodiments described above have many modifications. According to the grouping configuration information, the transceiving apparatus can perform various groupings of the data, and also, there are various module distributing schemes in the data processing system.
[0094] For example, with the increasing size of the antenna arrays, the data can be grouped into ten groups or dozens of groups or more. Thus, dozens or more processing apparatus might otherwise be needed in the data processing system for base band processing. Some of the processing apparatus can perform only the distribution and uplink sub-channel processing for some of the data, some can only perform uplink main processing, and some can simultaneously perform multiple processing. Thus, the present invention is not limited to the embodiments described above in detail, but can be extended to all the modifications that are possible for those skilled in the art under the teaching of the present description.
[0095] FIG. 7 illustrates the flow chart for the method of receiving data for a base station. As shown in the figure, first, in step 70 , grouping is performed for the data received by at least one RF header module according to the grouping configuration information, which relies on the needed computation resource and the resource available in the system. In an embodiment, the grouping configuration information is preset. In another embodiment, the grouping configuration information is automatically generated by the base band processing system of the base station. More specifically, a configuration managing apparatus in the base band processing system is provided to estimate the needed resource and resource available in the system, and generate the grouping configuration information according to the estimation result. Further, the step of grouping the data received by at least one RF header module includes: buffering the received data corresponding to the data channels in the RF header module, grouping the buffered data according to the grouping configuration information; and encapsulating the grouped data.
[0096] Then in step 72 , the grouped data is transmitted to at least one data processing apparatus. Specifically, in one embodiment, the data are put into one group, and directly transmitted to a data processing apparatus. In another embodiment, the data are grouped into a plurality of groups, and transmitted to a plurality of data processing apparatus through a switching apparatus, each of the plurality of data processing apparatus receiving one of the plurality of groups of data.
[0097] Then, proceeding to step 74 , in each of the at least one data processing apparatus, the grouped data are distributed into at least one uplink sub-channel according to the data channel of the received data. Specifically, in one embodiment, in each of the data processing apparatus that receives grouped data, a data distributer is provided to distribute the grouped data into at least one uplink sub-channel processing module, according to the data channel of the data, for uplink sub-channel processing.
[0098] Corresponding to the method of receiving data for a base station, also provided in the present invention is a method of sending data for the base station. FIG. 8 illustrates a flow chart of the method of sending data for the base station according to an embodiment of the present invention. As shown in the figure, first in step 80 , in each of at least one data processing apparatus, data in at least one downlink sub-channel is converged. Specifically, in one embodiment, in each of the processing apparatuses that performs downlink sub-channel processing, the data in each downlink sub-channel is converged by a data converger. When the data is converged, the path ID of each sub-path is retained for future identification.
[0099] Then, in step 82 , the converged data from at least one data processing apparatus is transferred to the transceiving apparatus. Specifically, in one embodiment, the data in each data channel is processed for downlink sub-path processing in one processing apparatus, and directly transferred to the transceiving apparatus after being converged. In another embodiment, multiple groups of data are processed for downlink sub-path processing in multiple data processing apparatus, and transferred to the transceiving apparatus through a switching apparatus after being converged in each data processing apparatus.
[0100] Then, advancing to step 84 , in the transceiving apparatus the converged data from at least one data processing apparatus are degrouped according to the grouping configuration information. Further, the step of degrouping data includes: deencapsulating the data, extracting the grouped data; degrouping the data according to the grouping configuration information; and buffering the degrouped data corresponding to the respective data sub-channel. Further, buffered data is finally transmitted to at least one RF header module. Those skilled in the art can understand that, the software modules and methods can be implemented by computer executable commands and/or by being included in the controlling codes of the processing apparatus.
[0101] While the present invention has been described with reference to what are presently considered to be the preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. On the contrary, the invention is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.
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A base station apparatus, methods of receiving and sending data, and a computer readable article of manufacture. A computer implemented method includes the following for receiving and sending data: receiving the data by an RF header module; grouping data received; transferring the grouped data to a data processing apparatus; distributing the grouped data into an uplink sub-channel; merging the distributed data using at least one downlink sub-channel; transferring the merged data to a transceiving apparatus; degrouping the merged data; and sending the merged data by RF header module. A method of receiving data, a method of sending data, and computer readable non-transitory articles of manufacture are also provided.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority under 35 U.S.C. §119(e) of Provisional Application No. 60/969,137, filed Aug. 30, 2007, which application is hereby incorporated herein by reference in its entirety. This application is related in subject matter to application Ser. No. 10/167,052, filed Jun. 10, 2002, now U.S. Pat. No. 6,645,075, which is hereby incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present inventions relate generally to the field of regulated pay computer-controlled games, either games of skills or games of chance.
2. Description of the Prior Art and Related Information
Electronic games of chance of the present day rely heavily on gambling's inherent tension to entertain players. This is to say that, other than the uncertainty surrounding whether a wager will result in the winning or losing of funds, such games offer the player little in the way of entertainment. Most slot machines, for example, feature repetitive wagering sequences in which there is no significant decision-making, no skill exhibited, and no building sense of purpose from one action to the next.
Casino video poker games have an advantage over video slot machines in that they allow the player to make real decisions with real consequences. These decisions, however, have fairly clear-cut solutions and are repetitive in nature-limitations that undercut much of the entertainment value they provide. It should also be noted that while the graphics and effects used within video slot machines have improved sharply within the past decade and thus contributed to those games' entertainment value, the visual effects used in video poker games have remained primitive.
Electronic games released for the home video game market feature elements of skill-based play that have long proved entertaining to players but that have not been widely used within the casino environment. These video games accurately measure and reward skills like rapid decision making, good hand-eye coordination, and manual dexterity such that players feel a correlation between their performance within the game and the results achieved. These games also allow players to experience a rising sense of excitement by providing them with goals and objectives within the game—such as completing tasks and advancing through “levels”—that give the gaming experience a greater feeling of purpose and meaning.
With the advent of the 21st century, slot machine manufacturers have come to realize the value of creating games that are attractive to an emerging generation of video-game savvy players. Bally Technologies has recently appealed to the home video gamers' sense of nostalgia by incorporating themes and icons from classic video games like Atari's Pong® into video slot machines. The Pong® game is essentially a traditional video slot machine that uses symbols taken from the classic Pong® arcade game, although players who randomly win a trip into the game's bonus round do get to demonstrate their skill in a 45 second bonus video game.
Pong® and other such slot-based games are unlikely to capture the attention of the home video game player for one key reason: a standard slot machine dressed up with video game themes and icons and an interactive bonus round is still, at its core, a slot machine. A generation of players who grew up fighting aliens, driving race cars, rescuing princesses and slaying dragons, all in brilliant graphics and sounds, is never going to be fully engaged by a game that derives its primary excitement from the player passively watching spinning reels.
Instead, this newer generation of player will demand casino games that measure real skill and that reward fast reflexes and good decision making. Players will not be satisfied with snippets of simulated video game play that occur only in secondary bonus games; they will demand arcade-style excitement from the moment their game begins until the moment it ends.
The challenge of developing an electronic casino game that rewards true skill from start to finish and yet returns a reliable yield to the game operator has, thus far, been unsolved by casino game manufacturers. From the foregoing, it may be appreciated that there has been a long felt need for games, gaming methods and gaming machines that offer both rewarding continuous arcade-style game play to the player and predictable profits to the game operator.
SUMMARY OF THE INVENTION
Games in which the return to player (RTP) is static cannot reward true skill, while games that are purely skill-driven cannot guarantee the operator profitability. The Return Driven Casino Game Outcome Generator according to embodiments of the present invention allows for the creation of the first class of true casino video games, meaning regulated games that both measure and reward the player's true skill and that hold a consistent and reliable percentage of funds wagered for the house. The present Return Driven Casino Game Outcome Generator is configured to deliver an authentic video game experience where other casino video game paradigms have failed because: 1) it makes skill-based, arcade-style play possible from the start of a game to its finish; 2) it may leverage Cyberview Technology, Inc.'s “Cashless Time Gaming” U.S. Pat. No. 6,645,075, to naturally and seamlessly transition scoring events that occur within a video game into opportunities for players to win funds; and 3) it turns the existing paradigm of casino game returns upside down, allowing the game to unfold in such a manner that is both truly random and governed by the game's predetermined RTP range.
Players wagering within a regulated game environment of a gaming machine featuring an embodiment of the present the Return Driven Outcome Generator may purchase the opportunity to compete in arcade-style play via a time-based contract. As the player initiates game play, each or selected “key event” within the game (i.e., positive events that would typically lead to the player scoring points in a non-wagering version of the game) may cause the game to reference a specific reward table associated with that event in a process that may lead, through calling the game's random number generator, to the player winning funds. Different classes of reward-triggering events within a game may or may not be associated with different reward tables. Players may be graded based upon the skill level they exhibit during game play within the regulated gaming environment such that players with above average skill may earn, on average, higher rewards. Skilled players may also positively affect their destiny by causing the Outcome Generator to create more favorable future in-game scenarios that reward their skill.
Accordingly, an embodiment of the present invention is a method of determining a reward due to a player of a regulated game. Such a method may include steps of enabling the player to interact with at least one reward generating asset within the regulated game; measuring a level of skill of the player in interacting with the at least one reward generating asset, and determining the reward due to the player for each successful interaction with the at least one reward generating asset, the reward being determined according to the measured skill level, a random number and a time elapsed since a last successful interaction with any one of the at least one reward generating asset.
According to further embodiments, the determining step may be carried out with the reward being comparatively smaller on average when the time elapsed is smaller than when the time elapsed is larger. The determining step may be carried out with the measured skill level determining an average RTP percentage of the regulated game. The determining step may be carried out with higher measured skill levels being associated with comparatively higher average RTP percentages than lower measured skill levels. The method may further include steps of selling to the player a contract of play time of a predetermined duration in the regulated game for a predetermined cost, and at least the enabling and determining steps may be carried out as long as the predetermined duration has not elapsed. The method may further include a step of computing a cost per unit of time of the contract by dividing the cost of the contract by the duration of the contract. The determining step may be carried out with the reward due to the player for each successful interaction with the at least one reward generating asset also being determined according to the cost per unit of time of the contract.
According to another embodiment thereof, the present invention is also a regulated gaming machine. The regulated gaming machine may include a display; a source of random numbers; at least one reward generating asset shown on the display, the at least one reward generating asset being configured to enable a player of the regulated gaming machine to interact therewith, the regulated gaming machine may be configured to measure a level of skill of the player in interacting with the at least one reward generating asset, the regulated gaming being further configured to determine the reward due to the player for each successful interaction with the at least one reward generating asset, the reward being determined according to the measured skill level, a random number obtained from the source of random numbers and a time elapsed since a last successful interaction with any one of the at least one reward generating asset.
The regulated gaming machine may be further configured such that the reward may be comparatively smaller on average when the time elapsed is smaller than when the time elapsed is larger. The measured skill level may determine an average RTP percentage of the regulated gaming machine. According to some embodiments, higher measured skill levels may be associated with comparatively higher average RTP percentages than lower measured skill levels. The regulated gaming machine may be further configured to sell to the player a contract of play time of a predetermined duration for a predetermined cost, and at least the enabling and determining steps may be carried out as long as the predetermined duration has not elapsed. The regulated gaming machine may be further configured to compute a cost per unit of time of the contract by dividing the cost of the contract by the duration of the contract. The regulated gaming machine may be further configured to also determine the reward due to the player for each successful interaction with the at least one reward generating asset according to the cost per unit of time of the contract.
According to yet another embodiment thereof, the present invention is a regulated multi-level game of chance. The regulated multi-level game of chance may include a source of random numbers; a first game level, the first game level including a plurality of first reward generating assets, a successful interaction with any one of the first reward generating assets generating a first reward, the first reward being dependent upon a first random number obtained from the source of random numbers and a time elapsed since a last successful interaction with any one of the first reward generating assets, and a second game level, the second game level including a plurality of second reward generating assets, a successful interaction with any one of the second reward generating assets generating a second reward, the second reward being dependent upon a second random number obtained from the source of random numbers and a time elapsed since a last successful interaction with any one of the second reward generating assets, a second average RTP percentage of the second level may be comparatively higher than a first average RTP percentage of the first level.
The game may be configured to determine a level of skill of a player of the game in the first game level, and the game may be further configured to allow the player to play the second level only when the determined level of skill reaches a predetermined threshold. The game may also include successively higher numbered game levels, each having with progressively higher average RTP percentages, and each accessible to the player upon being determined to have reached progressively higher levels of skill. For example, the regulated game may be configured as a first person shooter. Alternatively, the game levels may include a scripted narrative. The first reward generating assets of the first game level may be configured to return, on average, lower rewards upon successful player interaction therewith than may be returned upon successful player interaction with the second reward generating assets of the second game level.
The regulated game may further include a first reward table associated with the first reward generating assets, the first reward table including a first reward multiplier probability distribution and a corresponding range of first reward multipliers, the first reward generating assets being configured such that, upon successful player interaction therewith, the first random number may be used as a first index into the first reward multiplier probability distribution to obtain a corresponding first reward multiplier within the range of first reward multipliers and the first reward due may be a product of the first reward multiplier and a first collision wager that may be dependent upon the time elapsed since the last successful interaction with any of the first reward generating assets.
Similarly, the regulated game may further include a second reward table associated with the second reward generating assets, the second reward table including a second reward multiplier probability distribution and a corresponding range of second reward multipliers, the second reward generating assets being configured such that, upon successful player interaction therewith, the second random number may be used as a second index into the second reward multiplier probability distribution to obtain a corresponding second reward multiplier within the range of second reward multipliers and the second reward due may be a product of the second reward multiplier and a second collision wager that may be dependent upon the time elapsed since the last successful interaction with any of the second reward generating assets.
Another embodiment of the present invention is a regulated gaming method that includes steps of providing a source of random numbers; providing a first level of a regulated game, the first level including a plurality of first reward generating assets; setting a first average RTP percentage for the provided first level; generating a first reward upon a successful player interaction with any one of the first reward generating assets generating a first reward, the first reward being dependent upon the first average RTP percentage, a first random number obtained from the source of random numbers and a time elapsed since a last successful interaction with any one of the first reward generating assets; providing a second level of the regulated game, the second game level including a plurality of second reward generating assets; setting a second average RTP percentage for the provided second level, the second average RTP being comparatively higher than the first average RTP percentage, and generating a second reward upon a successful player interaction with any one of the second reward generating assets, the second reward being dependent upon the second average RTP percentage, a second random number obtained from the source of random numbers and a time elapsed since a last successful interaction with any one of the second reward generating assets.
The method may further include steps of determining a level of skill of a player in the first level of the regulated game, and enabling the player to play the second level of the regulated game only when the determined level of skill reaches a predetermined threshold. The method may further include steps of providing successively higher numbered levels of the regulated game, each having with progressively higher average RTP percentages, and each accessible to the player upon being determined to have reached progressively higher levels of skill.
The method may include a step of configuring the regulated game and/or the levels as a first person shooter and/or as a scripted narrative (for example).
The method may further include configuring the first reward generating assets of the first level to return, on average, lower rewards upon successful player interaction therewith than are returned upon successful player interaction with the second reward generating assets of the second game level.
The method may also include providing a first reward table associated with the first reward generating assets, the first reward table including a first reward multiplier probability distribution and a corresponding range of first reward multipliers and, upon a successful player interaction with any one of the first reward generating assets: using the first random number as a first index into the first reward multiplier probability distribution to obtain a corresponding first reward multiplier within the range of first reward multipliers, and calculating the first reward due as a product of the first reward multiplier and a first collision wager that is dependent upon the time elapsed since the last successful interaction with any of the first reward generating assets.
Similarly, the method may also include steps of providing a second reward table associated with the second reward generating assets, the second reward table including a second reward multiplier probability distribution and a corresponding range of second reward multipliers and, upon a successful player interaction with any one of the second reward generating assets: using the second random number as a second index into the second reward multiplier probability distribution to obtain a corresponding second reward multiplier within the range of second reward multipliers, and calculating the second reward due as a product of the second reward multiplier and a second collision wager that is dependent upon the time elapsed since the last successful interaction with any of the second reward generating assets.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts a high level flow of the wagering process within a regulated gaming environment featuring the Return Driven Outcome Generator, according to an embodiment of the present invention.
FIG. 2 shows further aspects of the Return Driven Outcome Generator, according to an embodiment of the present invention.
FIG. 3 demonstrates how collision intervals impact wagering within a regulated gaming environment using the Return Driven Outcome Generator, according to an embodiment of the present invention.
FIG. 4 demonstrates how regulated gaming environments featuring the Return Driven Outcome Generator according to an embodiment of the present invention may adjust their RTP based on player skill.
FIG. 5 demonstrates how the Return Driven Outcome Generator according to an embodiment of the present invention generates future reward generating assets and values thereof in a 2D horizontal scrolling video game.
FIG. 6 demonstrates how the Return Driven Outcome Generator according to an embodiment of the present invention assigns values for reward generating assets in a single screen maze-style game, in this case Namco's Pac-man®.
FIG. 7 demonstrates how the Return Driven Outcome Generator according to an embodiment of the present invention assigns values for reward generating assets in a single screen “shoot'm up” style game, in this case Midway's Space Invaders®.
FIG. 8 demonstrates how the Return Driven Outcome Generator according to an embodiment of the present invention assigns values for reward generating assets in a pinball game.
FIG. 9 depicts another embodiment of skill based scoring within the Return Driven Outcome Generator wagering model of the present inventions.
FIG. 10 depicts exemplary gaming machines on which embodiments of the present invention may be practiced.
DETAILED DESCRIPTION
In the following detailed description of exemplary embodiments of the invention, reference is made to the accompanying drawings, which 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, and it is to be understood that other embodiments may be utilized and that logical, mechanical, electrical 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.
FIG. 1 depicts a high level flow of the wagering process within a game featuring the Return Driven Outcome Generator (RDOG), according to an embodiment of the present invention. Games configured with RDOG may be configured with a fixed RTP range 102 that comes preinstalled on a gaming machine or may be configured to use an operator configurable average RTP percentage range. Operator configured games self-adjust to return an operator-input percentage of funds to the player and hold the rest for the house.
RDOG configured games, according to embodiments of the present invention, may feature skill-based grading 104 , such that players are graded on how they perform various tasks within the game, with the game using those player grades to determine where its actual average RTP percentage will fall within its preset average RTP percentage range 102 . For example, in a game with a preset average RTP percentage range of 98-92%, a player exhibiting no or minimal skill may cause the game to payout at the game's minimum 92% average RTP percentage, while a player exhibiting superior skill may cause the game to payout at the game's maximum payout percentage of 98%. It is important to note that, while lower-skilled players are assigned a lower average RTP percentage in this model, they still have an opportunity to win in a particular gaming session because of the game's inherent randomness.
According to embodiments of the present invention, once a RDOG game is assigned a preset average RTP percentage range and has determined which player skill grade is applicable (some games, according to further embodiments, may not use skill based grading while others, according to further embodiments, may default to an average player skill grade until the player has played long enough to earn his or her individual skill grade), this data is input into the Outcome Generator 106 . The Outcome Generator 106 performs at least two functions: the generation of Dynamic Reward Tables 108 and random number generation through a Random Number Generator (RNG) 110 . Dynamic Reward Tables 108 assign specific wagering properties to game reward generating assets appearing within a RDOG game. Note that not all game assets within a RDOG game may be configured as being reward generating. Whenever the player encounters, collides or otherwise interacts with those assets (i.e., when the player's Pac-man eats a bonus cherry (an example of a reward generating asset) or the player's pinball hits a bumper (another example of a reward generating asset)), a reward table for the award generating asset with which the player has collided may be referenced by a random number output from a Random Number Generator (RNG) and a corresponding reward multiplier 109 is output. That is, the RNG 110 generates a random number between 0 and 1 and that randomly generated number is used as a reference or index into the dynamic reward table for that reward generating asset and the corresponding reward multiplier 109 is read from the table. Note that the dynamic reward table 108 may be configured to assign a predetermined reward multiplier 109 for specific ranges between 0 and 1. As shown in FIG. 1 , the widest range may be associated with the lowest reward multiplier, with progressively narrower ranges being associated with progressively higher reward multipliers. However, the dynamic reward tables 108 may be configured with as little or as much variability (e.g., the difference between the lowest reward multiplier and the highest reward multiplier) as desired. According to an embodiment of the present invention, the reward multiplier 109 output from the outcome generator 106 may be used in conjunction at least with the wager size to determine the size of the player's financial reward for each collision or interaction (or successful collision or interaction) with a reward generating asset within a regulated gaming environment featuring RDOG functionality.
Several key factors may determine the size of the player's wager and, by extension, his reward when he collides with a reward-generating asset within an RDOG game. According to embodiments of the present invention, players may initiate a game by purchasing a time-based contract. Each second of that contract has a value that may be expressed by dividing the contract cost 112 by the contract duration 114 . For example, a 60 second contract that costs $6.00 has a contract value of 10 cents per second. According to embodiments of the present invention, once the value of time within the contract has been internally calculated, the size of a collision wager may be calculated by multiplying the value of time within the contract by how much time has elapsed since the last collision (a concept referred to hereafter as the “Collision Interval” 116 ). Therefore, the formula for determining a collision wager in a RDOG game may be expressed, according to one embodiment of the present invention, as (Contract Cost/Contract Duration)×(Collision Interval)=Collision Wager 118 . The Collision Reward Size 120 may then be determined by multiplying the collision wager 118 by the reward multiplier 109 output by the Outcome Generator 106 .
FIG. 2 provides additional details of an embodiment of the Return Driven Outcome Generator. As was detailed relative to FIG. 1 , average RTP percentage 102 is the key input into the RDOG. The average RTP percentage 102 that is input into the Outcome Generator 106 may or may not be altered as a result of skill-based grading within (and during) the game.
As is the case with all electronic games of chance, RDOG games derive their randomness from a random number generator 110 . It should be noted that while RDOG games according to embodiments of the present invention offer the player a radically different gaming experience than that of traditional slot machines, they require no changes or customizations to the standard slot machine RNG.
The most significant function of the Outcome Generator 110 is the generation of Dynamic Reward Tables such as shown at 108 in FIG. 1 and at 208 and 210 in FIG. 2 . These tables represent the foundation of RDOG casino video games, and may determine the probabilities at work for all significant in-game wagering events.
To understand the full functionality of the Outcome Generator, it is necessary to understand the two key classes of casino video games that it helps to create. The RDOG wagering system facilitates the creation of: 1) casino video games in which the full playing landscape is visible to the player at all times (referred to here as “single-screen” games) and 2) casino video games in which the playing landscape is revealed to the player on a gradual, screen-by-screen basis (referred to here as “multi-screen” games). The properties of reward-triggering game assets used in both the single-screen and multi-screen models are created by the Outcome Generator 106 .
In multi-screen games, according to embodiments of the present invention, future obstacles and reward triggers (assets within the gaming environment, a collision with which triggers an award) in the game may be generated randomly as the player encounters them. For example, in a car racing game in which the player can only see a small section of road in front of him, reward-triggering bonus flags (examples of reward generating assets) of different colors and reward levels may randomly appear in the driver's path as he races towards the finish line. This is the first key role of the Outcome Generator 106 , as it must assign the asset class and wagering properties/probabilities of future symbols as the player encounters them. This symbol assignment process may be accomplished, according to embodiments of the present invention, through calling an Asset Creation Reward Table 208 (a type of Dynamic Reward Table) that associates the probability that each symbol within the game's universe will appear before the player, shown on the X axis 212 with the reward multiplier associated with each different class of symbol, shown on the Y axis 212 . Based on this random call to these Asset Creation Reward Tables 208 , the game is able to randomly determine the appearance of a future symbol appearing within the game 216 and to determine the symbol's reward multiplier 109 (the quantity with which the collision wager 118 will be multiplied when the player collides with the newly generated reward generating asset to determine the collision reward size 120 ).
According to embodiments of the present invention, multi-screen games like the driving game described earlier may grade the player on skill as play unfolds—by measuring, for example, how long it takes a driver to reach certain predetermined milestones—and then use the stored grades to affect how the game generates future scenarios. For instance, if within a car racing game there are reward generating assets embodied as yellow bonus flags that return small rewards, blue bonus flags that return average sized reward, and green bonus flags that return large rewards, a particularly skilled player will encounter more green flags in his path based on his previously demonstrated skill level. This increased frequency of appearance of comparatively higher-valued reward generating assets occurs because the player's skill increases the game's average RTP percentage, which in turn may correspondingly increase the probability that higher-valued reward generating assets will appear as the game unfolds; that is, in the game's future. It should be noted that such skill-based changes to a game's future outcome generation do not compromise the randomness of the game; they affect only the probabilities of various future game scenarios occurring. Therefore, no new regulatory issues are raised by such skill-based games according to embodiments of the present invention.
The role of the Outcome Generator 106 in single-screen games according to embodiments of the present invention is different. In single screen games, the appearance/class of most game assets are known to the player at all times since the full gaming screen is always visible. In these scenarios, the player's reward multiplier when colliding with a given class of reward generating asset may not be fixed like in the multi-screen model, but rather may be determined randomly at the moment of collision. This reward multiplier generation is accomplished by referencing a different type of Dynamic Reward Table that is specific to the reward generating asset with whom the player has collided, shown in FIG. 2 as an Asset Valuation Reward Table 222 . In the Asset Valuation Reward Table 222 , all possible reward multiplier sizes are shown on the Y axis 220 and the probabilities of achieving each reward size are shown on the X axis 218 . The game's RNG 110 uses this table 222 to determine a reward multiplier 109 , which is the key output of Asset Valuation Reward Tables within the Outcome Generator 106 . For example, if the random number output from the RNG 206 is 0.8, the reward multiplier output 224 will be higher than if the random number output from the RNG 206 is 0.2.
FIG. 3 demonstrates how collision intervals impact wagering within a game using a Return Driven Outcome Generator, according to embodiments of the present invention. As noted above, the player may initiate an RDOG game by purchasing a time-based contract. The duration of this contract in FIG. 3 is represented by the horizontal Time Axis. As the player engages in RDOG game play, collisions occur. That is, the player collides with, touches, bounces off, passes a game milestone, kills an opponent, passes a threshold or otherwise successfully interacts with a reward generating asset within the game. Each or selected ones of such collision or interaction may initiate a “wager” within the game, where the player has the opportunity to win funds. These “wagers” are non-traditional in the sense that the player does not press a “bet” button to initiate them. However, such “wagers” share the spirit of traditional betting in the sense that they represent opportunities for the player to win funds. According to embodiments of RDOG games, wagers resulting from in-game collisions may only result in neutral or positive financial outcomes, meaning that the player's current balance cannot be lowered based on the outcome of a collision wager. However, other embodiments of the present invention may include RDOG games in which certain assets within the game are configured as penalty inducing assets, in which the player's current balance may be negatively impacted through interaction with such assets. Still further embodiments of the present invention may include reward generating assets and penalty inducing assets, and/or game assets that (e.g., randomly) change from reward generating to penalty inducing. In the description to follow, however, the assets are reward generating assets, it being understood that embodiments of the present invention may also be configured with penalty inducting game assets.
On the timeline depicted in FIG. 3 , collision wagers are represented by large dots on the Time Axis 302 . In this case, the first wager 306 is marked by the notation W 1 and the second wager 308 is marked by the notation W 2 . After starting the game at 304 , the pace with which the player collides with reward generating assets in the game affects his gaming experience. When the player collides frequently (e.g., W 1 , W 2 , W 3 , W 4 , W 5 , W 6 , W 7 , W 8 and W 9 ) with reward generating assets as shown at 310 , his wager sizes will be smaller. In contrast, when the player collides more infrequently (e.g., W 10 , W 11 and W 12 ) with reward generating assets as shown at 312 , his wager sizes will be comparatively larger. This dynamic, disclosed in commonly assigned U.S. Pat. No. 6,645,075, ensures that the game's average RTP percentage remains fixed regardless of the pace at which he plays, as frequent collisions are associated with smaller wagers, whereas more infrequent collisions are associated with comparatively larger wagers.
FIG. 4 demonstrates how games featuring a Return Driven Outcome Generator 106 may adjust their average RTP percentage based on player skill, according to embodiments of the present invention. FIG. 4 details skill-based grading in the context of an auto racing themed electronic game of chance, FIG. 6 details skill based grading and RDOG as applied to a maze-style arcade game, FIG. 7 details skill-based grading and RRDOG as applied to “shoot'm up” style games, and FIG. 8 details skill-based grading and RDOG as applied to pinball games. In fact, skill-based grading may be applied to almost any preexisting video game including but not limited to sports games like EA Sports' “Madden Football®”, 2D horizontal scrolling games like Nintendo's “Super Mario Bros®,” and 3D first person shooters like Bungie Studio's “Halo®” series of games.
FIG. 4 depicts a very simple racing game in which a car 402 races around a track 404 in an attempt to reach milestones. According to embodiments of the present invention, wagers may be placed in such a game whenever the car passes or collides with a reward generating asset embodied, in this game, as bonus flag 406 . Likewise, the game may also include a reward generating assets such as milestones, such as a milestone marker 408 . Another form of a reward generating asset may include an opponent, such as competing car 410 . In this case, a wager may be placed when the player (embodied as car 402 ) interacts with (e.g., passes or physically collides with, in the case of a demolition derby game) a reward generating asset (embodied as competing car 410 controlled by the game or another player) or, for example, when the car 402 passes other cars with which it is competing. If implemented in the game design and optionally enabled by operator or by player selection, wagers may also be initiated when the car 401 gets off track or crashes with an obstacle. In that case, there may be no penalty induced but just additional opportunities to wager and grade unskilled players. That is, running off the track or colliding with another car on the course (to use two representative examples) may not result in a wager that decreases the player's funds, but may result in a lower skill grade that may, in turn, negatively affect the player's average RTP percentage (and/or his or her opponent's average RTP percentage). The game may grade player skill internally by capturing the amount of time it takes the car to reach certain milestones (i.e. the “milestone interval”) 408 , by capturing the player's average speed, or through the use of any metric the game designer feels accurately measures the player's skill. That is, different time ranges may be associated with different average RTP percentages, as shown in the table 412 in FIG. 4 . For example, a relatively unskilled player that takes more than a minute to reach a milestone within a game (such as milestone 408 ) may be awarded a low average RTP percentage of, for example, 92. A player exhibiting relatively greater skills that takes between 50 and 59 seconds to reach the same milestone may be awarded a comparatively larger average RTP percentage (such as, for example 94), and a very skilled player that takes less than 50 seconds to reach the same milestone may be assigned the highest average RTP percentage of, for example, 96 . The average RTP percentage vs. graded skill distribution may be as coarse or fine-grained as desired. Likewise, the player's measured speed around the track and/or points collected may determine the player's assigned average RTP percentage, as shown in the table 414 in FIG. 3 . The average RTP percentage thus assigned to the player may then be filtered down into the dynamic reward tables of all game assets, such that skilled players may earn comparatively higher returns within the game, on average, than players having a comparatively lower skill level. This system provides motivation for players to learn to play a game well, since better player earn better average RTP percentages, but does not discourage less skilled players since the random element within the game gives even the least skilled player the opportunity to win funds through good fortune. According to some embodiments of RDOG games, the player's skill grade may be re-calculated at predetermined intervals or milestones during game play such that the average RTP percentage assigned to the player is dynamic in nature and changes during game play.
The following illustrates how RDOG games may dynamically self-adjust to reward skilled players. For example, player A may purchase a 1 minute contract to play an auto racing game for $6. In this example, player A is an unskilled player and is, therefore, assigned an average RTP percentage of 92, which is the lowest possible average RTP percentage within the game's preset average RTP percentage range. If player A's first collision with a reward generating asset within the game occurs 30 seconds into game play, his collision wager may be calculated as follows: ($6/60 seconds)×(30 seconds)=a $3 wager. Given that the player's average RTP percentage=92, the casino can expect to keep, on average, 24 cents for wagers such as this one ($3 wager×8% casino hold=24 cents lost), although the actual result of the single wager in question will be governed by the game's RNG and the specific dynamic reward paytable associated with the reward generating asset with which the player has collided.
Continuing with this example and within the same game, player B purchases a 3 minute contract to play for $18. Player B is known to be or is determined to be a highly skilled player and is, therefore, assigned an average RTP percentage of 98, the highest possible average RTP percentage with the game preset average RTP percentage range. If player B's first collision within the game occurs 10 seconds into game play, his collision wager may be calculated as follows: ($18/180 seconds)×(10 seconds)=a $1 wager. Given that this player's average RTP percentage=98, the casino can expects to hold only 2 cents of Player B's wager long term, which represents a reward for his skilled play. Notice, then, that such a system provides both a reward to the player for good performance and a guaranteed positive return for the casino.
The auto racing track featured in FIG. 4 is depicted in its entirety for purposes of illustration. It should be noted that auto racing games in which the driver may only see a small segment of the track in front of him at any given time (i.e. multi-screen games) are more common and are sufficiently accounted for within the present RDOG model. Methods of future asset generation in multi-screen games are detailed further relative to FIG. 5 .
FIG. 5 demonstrates how a Return Driven Outcome Generator according to an embodiment of the present invention may generate future reward generating assets and game asset values in a 2D horizontal scrolling video game. Ever since the advent of early Atari video game classics like Activision's Pitfall, 2D horizontal scrolling video games have held a segment of the video game market. Such games are good candidates for RDOG play because of their multi-screen nature, which gives them the ability to generate future reward generating assets as those assets enter the player's field of vision. FIG. 5 shows a simplified version of a farm-themed 2D horizontal scrolling game in which an animated farmer 502 travels across a landscape encountering farm animals (reward generating assets) that have escaped from his barn such as dogs 504 , sheep 506 , pigs 508 , and cows that he may “capture.” In the game's premise, any time the farmer captures an animal he is given a reward.
As the farmer 502 travels along the game's landscape, the game dynamically generates the animals he will encounter at symbol creation intervals 510 that may be either random or predetermined. The determination of a new symbol's identity 512 occurs at random, based on a dynamic reward table 514 created by a Return Driven Outcome Generator such as shown at 106 in FIGS. 1 and 2 . In the depicted example, any of four animals may be created, with dogs being the most likely animal to be created (35% of the time a dog will be created) as shown at 516 and with cows being the least likely animal to be created and carrying the largest reward multiplier (4.1×) 518 to the player when captured by the farmer. Notice that the X axis on the Asset Creation Reward Table shows the probability 212 of each animal being created and the Y axis 214 contains the reward multiplier 109 associated with the capturing of each animal.
In this example, the size of a player's reward when encountering an animal in this game may be captured in the following formula: (Contract Amount/Contract Duration)×Collision Interval×Reward Multiplier. For example, a player having purchased a 1 minute contract for $6 who collides with a dog in after 10 seconds of collision-free game play would earn: ($6/60 seconds)×10 seconds×1.1 reward multiplier=$1.10 reward.
The game may be configured such that, should the player deliberately avoid capturing an animal in this scenario—by, for example, jumping over it—the player would surrender his collision reward and a new collision interval would begin. This scenario is equivalent to a video poker player deliberately discarding a reward generating hand like a straight flush that has been dealt to him pat. In the manner that some video poker machines force players to hold reward-generating hands (like a royal flush), embodiments of RDOG game may be configured to force players to accept wagering opportunities presented to them.
2D horizontal scrolling games such as the farm game of FIG. 5 may also include elements of skill-based grading such that players with a high degree of skill achieve larger rewards when encountering reward generating assets within the game. For example, the game may feature obstacles such as hay bales 520 that must be jumped over or cleared with a pitchfork, creeks that must be crossed, or hostile animals (such as a coyote, for example) with whom the farmer must engage in battle, etc. Such obstacles may be generated at random or they may appear at fixed intervals. Within the premise of the described game, players who negotiate such obstacles with a greater success rate may receive larger rewards when encountering reward generating assets such as dogs, pigs, sheep, and cows, as the player's skill grade will increase the player's average RTP percentage and cause the game to generate more generous reward tables in the skilled player's future.
It should be noted that while the foregoing demonstrates how RDOG-enabled games according to the present invention may create reward generating assets not yet encountered by the player in a 2D horizontal scrolling game, the same concept can easily be applied to a 3D maze style game like Doom® or Halo® in which players enter new rooms or segments of a maze and encounter reward generating that had previously been outside of their field of vision.
FIG. 6 demonstrates the manner in which embodiments of the present invention may assign values for reward generating assets in a single screen maze-style game, in this case Namco's Pac-Man®. In the RDOG version this arcade classic, the player maneuvers his Pac-Man character 602 through an onscreen maze 604 looking to eat pellets 606 and power pellets 608 while avoiding non-blue ghosts 610 . As in the arcade style version of the game, whenever the player eats a power pellet 608 , the ghosts turn blue and the Pac-Man has a brief window of time to eat them and be rewarded. In the RDOG version of the game, each time the player collides with a reward generating asset—in this case, a cherry 612 or a power pellet 608 , or a blue ghost, the player has the opportunity to win funds by entering into a wager that may be determined by, for example, a combination of the player's assigned average RTP percentage, the reward multiplier as determined by an Asset Valuation Reward Table and the amount of time that has elapsed since the player's last collision (e.g., the time interval since the player last ate a cherry, power pellet or ghost), computed as detailed above.
As is indicated in FIG. 6 , each reward generating asset may have an Asset Valuation Reward Table (such as shown and described relative to reference numeral 222 in FIG. 2 ) associated therewith. In this example, blue ghosts are associated with an Asset Valuation Reward Table 614 that is separate from the Asset Valuation Reward Table for cherries 616 . While both blue ghosts and cherries are associated with the same average RTP percentage (96 in this case), it should be noted that they have different volatility levels. The blue ghost Asset Valuation Reward Table 614 returns medium sized reward multipliers most of the time, while the cherry Asset Valuation Reward Table 616 returns a very small reward multiplier most of the time and a very large reward multiplier once in a great while. The RDOG model according to embodiments of the present invention allows game designers to add excitement to games by programming in both non-volatile “small reward” reward generating assets like the blue ghost and very volatile “home run” style reward generating assets such as the cherry in the example developed herein. This flexibility allows players to accumulate many small wins throughout game play to keep them invested while also giving them opportunities to win larger rewards periodically. If implemented in the game design and optionally enabled by operator or by player selection, wagers may also be initiated when the non-blue ghost eats Pac-Man®. In that case, there may be no penalty induced but just additional opportunities to wager and grade unskilled players (and optionally change their currently assigned average RTP percentage).
Maze-style games like Pac-Man® may also employ skill-based grading. This concept is demonstrated in table 618 , which makes a version of casino Pac-Man® possible in which players who average a greater number of pellets eaten per collision with a non-blue ghost within the game earn a higher average RTP percentage than lesser skilled players.
FIG. 7 demonstrates how the present Return Driven Outcome Generators may assign reward generating asset values in a single screen “shoot'm up” style game, in this case Midway's Space Invaders®. In the RDOG version of this arcade classic, players maneuver their cannon 702 on a horizontal plane using shields 704 to protect themselves from bombs dropped by various forms of aliens 706 , 708 . Players also use the cannon to shoot 710 at the aliens in an attempt to destroy them. Whenever the player's gunfire successfully hits an alien 712 or other reward generating asset, a specialized reward table 716 for the destroyed reward generating asset is referenced by the game's RNG and the player has the opportunity to receive a financial reward using the reward multiplier obtained by applying the output of the RNG to the reward table 716 . The player's skill level in this “shoot'm-up” style game (in this case, his or her ability to destroy aliens) affects the average RTP percentage, with lesser skilled players being assigned a smaller average RTP percentage than comparatively more skilled players. It should be noted that first person “shoot'm-up” games such as Microsoft's Halo®, for example, may be readily adapted to feature RDOG functionalities.
It should also be noted that single-screen arcade games like Space Invaders® or Pac-Man® often progress to new and more difficult screens/levels when an existing screen is “conquered” or completed. For example, in Pac-Man® when all of the pellets within a maze are eaten, a new and more difficult maze appears on screen in which the ghosts move faster, the power pellets result in a shorter window to eat the ghosts, etc. In Space Invaders®, when a player destroys all of the aliens on the gaming screen, a new fleet of aliens appears that advances downward toward the player's cannon at a greater rate of speed. Casino RDOG adaptations of these games (or games specifically designed for RDOG casino video game play) may also feature levels of escalating difficulty. In such scenarios, game play may continue without any changes, or the player may be rewarded for reaching a higher game difficulty level by encountering more generous asset reward tables, a greater frequency of reward generating assets, more lenient skill-based grading, or by any other measure game designers wish to implement that does not compromise the game's predetermined average RTP percentage or average RTP percentage range or affect the RNG.
FIG. 8 demonstrates an electronic or video pinball game adapted to include the functionalities of embodiments of the present invention. In the RDOG version of this arcade classic, players launch a virtual ball into a virtual pinball playfield 802 and attempt to win funds by causing the ball to collide against various in-field reward generating assets such as circular bumpers 804 , rails 806 , and triangular rails 808 . When the player's ball falls into the gutter 810 at the bottom of the playfield, a playing session is over and he must launch a new ball into the playfield. The player may use a series of flippers 812 to propel the ball upward toward the reward generating assets and away from the gutter.
According to an embodiment of the present invention, whenever the player's ball collides with reward generating assets (bumpers, rails, flippers, etc), the game references a specific reward table associated with the reward generating asset with which the ball has collided and provides the player the opportunity to receive a financial reward using the reward multiplier derived from the application of the output of the RNG to the specific reward table associated with the reward generating asset with which the ball has collided. For example, when the player's ball collides with the circular bumper 814 , a reward table specific to that reward generating asset 816 referenced and the game's RNG determines the player's reward. Different reward generating assets within the game may be associated with different reward tables. Alternatively, several reward generating assets or several kinds of reward generating assets may be assigned a same reward table. The reward tables themselves may be configured as desired. For example, the triangular rail 808 is depicted in FIG. 8 to be associated with a considerably more volatile reward table 818 than that of the circular bumper 814 , in that most collisions with the triangular bumper 808 will result in a small reward multiplier and a very few such collisions will result in a very large reward multiplier.
FIG. 9 depicts another embodiment of skill based grading within the Return Driven Outcome Generator wagering model of the present invention. Whereas FIG. 1 demonstrates a model of RDOG wagering where a player's skill level determines where the game's average RTP percentage falls within a preset, sub-100 range, FIG. 9 presents a model in which all games begin with an average RTP percentage of 100 as their base 902 . In this mode of game play, referred to hereafter as the “full-pay” model, a player's skill is graded not by his ability to perform tasks effectively, but rather by his ability to avoid negative in-game events that interrupt game play. Whenever players playing a full-pay RDOG game fail to avoid an interrupting in-game event, they are assessed a time-based penalty that reduces their potential financial reward 904 . All other elements of full-pay RDOG wagering model are identical to the model outlined in FIG. 1 .
To demonstrate this model, we will examine a scenario in which a player buys into a full-pay RDOG Pac-Man game by purchasing a 60 second contract for $6. When that player's Pac-Man® collides with a non-blue ghost, he loses a life and his game play is interrupted for a predetermined amount of time. For the purposes of this example, we will set that time penalty at 5 seconds. This period of time in which the player is penalized is not added to his next collision wager. Because every second of game play has a set value in the RDOG model (in this case each second is worth 10 cents), when the player forfeits time by making a mistake, he reduces his returns. By losing 5 seconds, the player has forfeited 50 cents of value from a $6 contract and effectively reduced the average RTP percentage of his game from 100 to 91.7%.
The full-pay model appeals to players because it gives them the opportunity to play a casino game optimally at no disadvantage since mistake-free play results in an average RTP percentage of 100. Rarely in the casino environment are games offered to the player that afford him the opportunity to play legally and face no built-in house advantage. Because players rarely actually play optimally—the casinos have loads of data confirming this reality for video poker—gaming operators have little to fear from putting a full pay machine on their gaming floor.
Regulatory restrictions in many gaming jurisdictions stipulate the minimum average RTP percentage that game operators may assign to a game. Because the full-pay model has no average RTP percentage “floor” and might punish terrible players with perpetual penalties that would slash their returns, a false average RTP percentage floor (i.e., a minimum average RTP percentage) may need to be built into full pay RDOG games, which may be accomplished by assigning to each gaming session a maximum time-based penalty. For example, the Pac-Man® game described earlier may institute a maximum 10 second penalty per 60 second contract, ensuring that the game's average RTP percentage never dips below 83.3% ($5 actually wagered at no disadvantage/$6 in wagers purchased=an average RTP percentage of 83.3%).
The full-pay RDOG model applies cleanly to a variety of arcade style games. Pinball players may face a time penalty when their ball goes into the gutter. Space Invaders players may be penalized when their cannon is hit by alien fire. Race car drivers may be penalized when they crash. Part of the appeal of the full-pay RDOG model according to embodiments of the present invention is that it ties in very naturally with existing arcade game paradigms. Aspects of the full-pay model may be used in conjunction with the embodiments shown and described above, such that the player may be rewarded for successfully colliding with reward generating assets and for successfully avoiding negative in-game events that interrupt game play.
It should also be noted that the time based penalties system demonstrated in FIG. 9 may also be advantageously used in non-full pay games (i.e. games with average RTP percentages other than 100). Operators may input any average RTP percentage they desire into this model including average RTP percentages lower than 100 (to ensure profits) or average RTP percentages higher than 100 (to offer an incentive to players akin to current “optimum play” video poker machines).
FIG. 10 illustrates exemplary gaming machines 1006 , 1010 , 1012 , 1016 and 1018 on which embodiments of the present invention may be practiced. These gaming machines are only representative of the types of gaming machines with which embodiments of the present invention may be practiced. In practice, however, there are no limitations on the types of regulated gaming machines on which embodiments of the present invention may be practiced. Embodiments of the present invention may be practiced on gaming machines that are coupled to a central system (e.g., a central server) 1002 and/or on gaming machines that are coupled to other gaming machines over a network, such as shown at 1004 . As is known, the gaming machines may also be coupled to a cashier terminal or an automatic cashier (not shown) and/or other devices. The network 1004 may be wired and/or wireless and may include such security measures as are desirable or required by local gaming regulations. Moreover, the gaming machines 1006 , 1010 , 1012 , 1016 and 1018 may be of the traditional cash-in type that includes coins and/or notes acceptors and coins and/or notes dispensers. Alternatively, one or more of the gaming machines 1006 , 1010 , 1012 , 1016 and 1018 may be of the cashless type such as disclosed, for example, in commonly assigned U.S. Pat. No. 6,916,244, the disclosure of which is hereby incorporated herein by reference in its entirety. The gaming machines 1006 , 1010 , 1012 , 1016 and 1018 may be co-located (such as on a casino floor) or widely separated across or within geographical, enterprise, regulatory or functional boundaries. The gaming machines 1006 , 1010 , 1012 , 1016 and 1018 may each include one or more displays 1022 , one or more computers 1020 within locked enclosures 1024 suitable for executing one or more regulated games of chance and player interaction mechanisms, devices, and/or other means configured to enable one or more players to interact with the games of chance.
According to an embodiment thereof, a network of gaming machines may be configured to make one or more games available to a player. For example, each gaming machine may be dedicated to a single game implementing the RDOG functionality disclosed herein or may be configured to enable the player to select one of a plurality of RDOG-configured games (and optionally other non RDOG-enabled games as well) to play. Such games may be stored locally on each gaming machine and/or may be downloadable from one or more central server 1018 upon request, as disclosed in application Ser. No. 10/789,975, filed Feb. 27, 2004, which application is hereby incorporated herein by reference in its entirety.
While the foregoing detailed description has described several embodiments of this invention, it is to be understood that the above description is illustrative only and not limiting of the disclosed invention. For example, while several classic video games like Pac-Man® and Space Invaders® were described, the RDOG wagering system could just as easily be applied to any popular video game including new titles like RockStar Gaming's Grand Theft Auto®. Moreover, embodiments of the present invention are not limited to RDOG adaptations of existing video games. Instead, new skill-based games may be developed and provided with RDOG functionalities.
According to other embodiments, events other than player skill (whether under the player's control or not) may also influence the average RTP percentage of a given player game session. Indeed, the average RTP percentage may be increased or decreased depending upon the time of the day or the day of the week or depending upon the length of the contract purchased by the player. Moreover, in video games that are played cooperatively among several players on networked gaming machines, the team's success in attaining the game's objectives may influence the average RTP percentage that is applied to all members of the team. Alternatively, each member of the team may be assigned his or her own average RTP percentage, depending upon his or her skill and/or ability to meet sub-objectives within the game and/or in proportion to his or her contribution to the game mission's outcome.
According to other embodiments, a player's earned average RTP percentage may be saved within his or her saved profile. For instance, each player may be identified by a player loyalty card, and his or her earned average RTP percentage may be saved along with other player-specific data in the player profile stored on the loyalty card or on a central server to which the gaming machines in the casino are coupled. Thereafter, when the player returns to a previously played game, the player may be identified by means of the loyalty card, and that player's average RTP percentage may be retrieved and applied, in combination with the game's RNG to determine the value of the reward multiplier whenever the player collides with a reward generating asset within the game.
According to further embodiments, player characteristics or actions other than skill may influence the average RTP percentage. For example, in the game Bioshock®, published by 2K Games, the player collects weapons, health packs, and Plasmids that give him special powers such as telekinesis or electro-shock, while fighting off the deranged population of the underwater city of Rapture. At times, the player is called on to make quasi-ethical decisions to save or kill (harvest) characters called “Little Sisters” (who resemble lost and frightened little girls) that collect a substance called “Adam” from the dead. The “Adam” collected by a killed Little Sister helps the player survive the toxic game environment. In such a case, the average RTP percentage may be decreased (or increased, for that matter) each time a player makes a decision that, albeit useful in achieving the game's objectives, is ethically questionable or outright wrong. In this regard, it may be seen that embodiments of the present invention may leverage the player's internal conflict of conscience (earn a high average RTP percentage or behave unethically) to great advantage to create compelling escapist game play, while insuring a predictable revenue stream for casino operators. A number of other modifications will no doubt occur to persons of skill in this art. All such modifications, however, should be deemed to fall within the scope of the present invention.
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The Return Driven Casino Game Outcome Generator (RDOG) makes the first true class of casino video game possible by creating games that measure and reward skills like fast reflexes and manual dexterity while earning consistent and reliable profits for game operators. In RDOG, a method of determining a reward due to a player of a regulated game may include steps of enabling the player to interact with one or more reward generating assets within the regulated game; measuring a level of skill of the player in interacting with the reward generating assets, and determining the reward due to the player for each successful interaction with the reward generating assets, the reward being determined according to the measured skill level, a random number and the time elapsed since a last successful interaction with any one of the reward generating assets.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to atomization and application of fluids, such as paints, to a surface and to apparatus which minimizes loss of such fluids into the atmosphere.
2. Description of Related Art
Airless spraying equipment operate using pressures of 1800 to 2500 psig. Through the use of hydraulic pressure, fluid is conveyed to a spraying apparatus where it is forced through a small orifice. The high pressure by which it is propelled is responsible for "bounceback" whereby the fluid literally bounces back into the atmosphere of the work place. The fluid contaminates the environment, the worker, and the equipment.
The most prominent method of spraying a liquid or a powder is to use a high pressure gas, such as air, to entrain and carry the liquid or powder to a substrate or target. The high pressure gas explodes into the atmosphere creating a turbulence and finely pulverizes the solids. This turbulence dispenses the particles over a large area producing a deleterious fog or mist of toxic fumes and harmful solids. The danger to the worker, to the environment and to cost containment is obvious.
A conventional pneumatic spraying apparatus use high pressure, low volume compressor air at 50 to 60 psig and 4 or 5 cfm in concert with an air regulator to atomize fluids. Spraying with such an apparatus produces a wasteful cloud of fluid and air commonly referred to as "overspray". Overspray is created by the explosive expansion of the mixture of solids, liquids, and gas at the nozzle of the spray gun. Overspray contains an aerosol of fluid drops and solid particles including drops of 5 to 35 microns in diameter. Solvents in the fluid being sprayed are referred to as volatile organic compounds (VOC). VOC entrained in overspray rapidly evaporates. The VOC become part of the atmosphere and present a hazard to the environment and to the operator. Overspray also may be generated from the spraying of powders, in which case the overspray consists of an aerosol of solid particles.
A high volume low pressure (HVLP) spraying apparatus uses air at a low pressure and high volume. The term "HVLP" as used in this application means air delivered in a volume in cubic feet per minute (cfm) which exceeds the pressure of the air in pounds per square inch (psi). High pressure low volume (HPLV) as used in this application means air delivered in a volume in cfm which is less than the pressure of the air in psi. For example, air delivered at a volume of 22 cfm at pressure of 8 psi would be HVLP air. The relationship between the pressure and volume measurements, not the absolute numbers, defines HVLP. Air at 30 psi and 80 cfm would be classed as HVLP air, while air at 80 psi and 30 cfm would be classed as HPLV air. Typically EPA approved HVLP air is at a pressure of up to 10 psi and a volume of up to 30 cfm.
HVLP spraying reduces the incident of bounceback because the fluid sprayed contacts the target surface at a relatively low velocity. HVLP spraying reduces the incidence of overspray because the explosive expansive atomization of fluid which produces the aerosol is minimized when low pressure air is used.
In conventional usage, "overspray" is used as a genetic term which includes bounceback and overspray as described above, and is sometimes called errant spray. This generic usage will be used here.
U.S. Pat. No. 4,850,809, incorporated herein by reference, discloses an apparatus for HVLP spraying.
Transfer efficiency (T.E.) is a measurement used for comparing methods of atomization. T.E. is expressed as a percentage of the solid substances sprayed that become part of a substrate or arrive at the intended target. Conventional pneumatic spraying has a T.E. of 25%; airless spraying has a T.E. of 40%; and HVLP spraying has a T.E. of 75%.
The Environmental Protection Agency has expressed special concern about the hazards associated with airborne particles of a diameter of 10 microns or less (PM 10 ). That Agency has established regulations controlling PM 10 concentrations in outdoor applications, such as shipbuilding, bridges, towers, and architectural coatings. The production of PM 10 is virtually uncontrollable when conventional spraying or airless methods are used.
The production of VOC is often regulated in terms of tons VOC/day emitted per site. A typical spray booth is ventilated by a flow of air at 150 ft 3 /minute per ft 2 surface being painted. The contaminated air is then treated to remove the VOC and PM 10 , often by incineration, a very expensive process.
Two trends have emerged from efforts to protect the environment from solvents and aerosols resulting from overspray. In order to prevent bounceback spraying pressures are limited to 10 psig in most locations. In order to reduce solvent entry into the atmosphere, fluid formulations containing as much as 80% solids are often used.
The present invention uses directed HVLP air emitted from an elongated nozzle, termed an "air chisel", to entrap overspray onto the target surface and prevent the entry of overspray into the environment.
U.S. Pat. No. 2,438,471 discloses a curtain of air introduced around the spray nozzle which traps the rebounding portions of the coating mixture and forces it against the surface being coated. The air curtain is emitted through a series of holes in an annular air chamber extending entirely around the spray nozzle.
U.S. Pat. No. 1,897,173 discloses a cap like spray nozzle in which a central stream of liquid is surrounded by an annular air port. The liquid stream is modified by two opposed supplemental air ports which shape the emitted spray into a fairly sharply defined ellipsoid cross-section. The streams of air from the supplemental air ports form a tubular air sheath surrounding the liquid stream which forms the liquid stream into a fan-shaped spray.
The above two patents disclose apparatuses which use a curtain of air pressure. Each invention was made before the development of the use of HVLP air in spraying, when only HPLV air was in use. Although the air pressure and volume ratios are not disclosed in the above two patents, one may reasonably conclude that each used air at HPLV.
U.S. Pat. No. 2,101,922 discloses an apparatus for spraying melted paraffin onto porous surfaces. The stream of paraffin is surrounded by a sheath of heated air. One venturi arrangement is used to atomize and propel the paraffin in a stream of air while a second concentric venturi is used to provide the sheath of heated, low-pressure air.
U.S. Pat. No. 5,062,572 discloses an agricultural liquid sprayer having a wind shield to prevent disruption of the spray pattern by employing the wind to the advantage of the sprayer. The wind shield is in the shape of a horn which captures a side wind and directs it in the direction of the spray pattern.
U.S. Pat. No. 5,393,345, incorporated herein by reference, discloses an apparatus for having a jet venturi induction pump and respray nozzle mounted near the front of a sprayer. Overspray is captured by the induction ports of the induction pump and redeposited on the work surface.
SUMMARY OF THE INVENTION
This invention uses an oriented air curtain to contain and trap overspray and prevent the entry of overspray into the atmosphere. The air curtain is generated from HVLP air by a nozzle unit comprised of an elongated nozzle, a bore, and a conduit for LPHV air. The nozzle unit and oriented air curtain taken together are termed an "air chisel".
The plume, or profile of the area of impact of the sprayed material with the work surface, is typically in the shape of an elongated ellipse, with a long axis along the longest dimension of the plume, and a short axis along the shortest dimension of the ellipse. The air curtain formed by the elongated nozzle is also in the shape of an elongated ellipse, having a long and a short axis. In this invention the long axis of the plume is approximately parallel to the long axis of the air curtain. The air curtain is emitted from the nozzle or nozzles mounted at the side of the spray nozzle and directed inwardly toward the plume.
The air chisel gently blows the overspray back against the work surface, thereby reducing escape of overspray into the atmosphere and at the same time producing a better coating on the sprayed work surface.
The objective of this invention is to reduce the emission of overspray into the atmosphere associated with spraying of atomizable liquid or powder.
Another objective is to provide a sprayed work surface having superior coating.
Another objective is to economize on the use of atomizable liquid or powder by maximizing the coating obtained from a given quantity of material sprayed.
Another objective is to increase the production rate of sprayed objects.
Another objective is to protect the health of operatives by inhibiting the generation of aerosols of material sprayed.
Another objective is to reduce the quantity of airflow required to protect the operatives from overspray generated at a work surface.
Another objective is to reduce the requirement for respirator use by operatives.
Another objective is to provide a spray gun having a shield which directs the air chisel toward the work surface and which increases the effectiveness of the air chisel in suppressing overspray.
Another objective is to provide a spray apparatus which functions in an efficient, effective manner with minimal environmental impact.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram showing the suppression of overspray by two air chisels.
FIG. 2 is a diagram showing the spray plume and the air plumes of FIG. 1.
FIG. 3A is a diagram showing the generation of overspray by a spray gun spraying on a work surface.
FIG. 3B is a diagram showing the suppression by air chisels of overspray generated by a spray gun spraying on a work surface.
FIG. 4 is a side view of a spray gun with attached nozzle unit.
FIG. 5 is a front view of a spray gun with two attached nozzle units.
FIG. 6 is a side view of a nozzle unit attached to a stand.
FIG. 7 is a side view of a nozzle unit having a jet induction pump attached to a stand.
FIG. 8 is a side view of multiple nozzle units attached to a bar.
FIG. 9 is a front view of multiple nozzle units attached to a bar.
FIG. 10 is a side view of an operator spraying a work object in a spray booth with multiple nozzle units mounted on a bar and attached to the spray booth.
FIG. 11 is a top view of the operator spraying a work object of FIG. 9.
FIG. 12 is side view of a second embodiment spray gun with attached nozzle unit having a shield.
FIG. 13 is a diagram showing suppression of overspray by two air chisels in a second embodiment spray gun with attached nozzle unit having a shield.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is a diagrammatic side view of a spray gun with two attached nozzle units. A spray gun 30 sprays atomizable liquid or powder 50 from a spray nozzle 33 onto a work surface 46. The generation of a small amount of overspray 52 is shown.
The generation of overspray is suppressed by two air chisels 12. An air chisel consists of a nozzle unit 12 in combination with an oriented air curtain 54. The nozzle unit 13 emits HVLP air from an elongated nozzle 23 in an air curtain 55 which forms an ellipse-like shape or air plume 55 on contact with the work surface 46. The air plume is adjacent to the ellipse-like shaped spray plume 51, which is the shape of the contact of the sprayed liquid or powder and the surface of the work. The elongated air plume is parallel and adjacent to the spray plume.
The relationship between the air curtains of the air chisels and the spray plume of the sprayed material is shown in FIG. 2. The sprayed plume 51 has a long axis 53 and a short axis 56. Each air plume 55 has a long axis 57 and a short axis 59. The long axis 57 of each air plume 55 is approximately parallel to the long axis 53 of the spray plume 51.
FIG. 1 shows the orientation of the air curtain 54 with respect to the work surface 46. A line 63 is drawn perpendicular to the work surface 46. The air curtain 54 is inclined to the line 63 at an angle 65 which is from 10° to about 80° to the line 63.
Each nozzle unit 12 consists of an elongated nozzle 23, a bore 10, and a conduit or hose 21 which provides HVLP air.
In FIG. 1, each nozzle unit 12 is attached to the spray gun 30 by a ring 34 which surrounds the barrel of the spray gun Two spray gun posts 38 are attached to the ring on opposite sides of the spray gun. An adjustable coupling 36 connects the spray gun posts 38 to the nozzle unit post 37. Each nozzle unit post 37 is connected to the respective bore 10 by a nozzle unit ring 39. The adjustable coupling 36 allows the orientation of the air curtain to be varied as desired.
The effect of the air chisels is to inhibit, contain, and retard the development of overspray 52. In this process, the loss of sprayed material to overspray and the generation of VOC is inhibited. In addition, the effect of the air curtains causes the sprayed material to form a smoother, finer finish on the work surface.
The orientation of the air curtains with respect to the work surface may be varied depending on the nature of the sprayed liquid or powder. A relatively light sprayed material of low viscosity liquid will use an orientation in which the air curtain is approximately parallel or at a relatively small inclination, 10°, to a line perpendicular to the work surface. The use of a relatively heavy or highly viscous sprayed material will require the orientation of the air curtain at a greater angle, up to 80° to the line perpendicular to the work surface.
FIG. 3A is a diagram showing a spray gun 30 which emits sprayed material 50 from a nozzle 33. The sprayed material 50 contacts the work surface 46 with the generation of overspray 52. This invention may be used with spray guns which use HVLP or HPLV or airless spraying systems. The maximum overspray is generated with HPLV spraying. A lesser amount of overspray is generated with HVLP spraying; and a minimum with airless spraying; but all systems generated overspray.
FIG. 3B is a diagram showing the effect of air curtains 54 on the overspray 52 of FIG. 3A generated by spraying sprayed material 50 from the nozzle 33 of a spray gun 30 on a work surface 46. The overspray is eliminated. The sprayed material of the overspray is deposited on the work surface and is not emitted into the atmosphere.
FIG. 4 is a side view of a spray gun with a nozzle unit attached. The spray gun 30 has an air hose 31 for provision of atomizing air and a reservoir 32 which holds the material to be sprayed, atomizable fluid or powder. The sprayed material is emitted by the nozzle 33. A nozzle unit 12 is attached to each side of the spray gun. The air curtain is emitted from the elongated nozzle 23 which is attached to the bore 10. HVLP air is provided to the bore through a hose or conduit 21. HVLP air passes from the conduit through the bore and is emitted by the elongated nozzle.
The nozzle unit 12 is attached to the spray gun by a barrel ring 34 which, in turn, is attached to a bore ring 39.
FIG. 5 is a front view of the spray gun 30 of FIG. 4. In this view, the reservoir 32 is omitted for clarity. The nozzle is at 32. The air hose 31 provides air to the spray gun. The air source 40 provides air to the spray gun 30 and also to the nozzle units 12 of the air chisels. The air source may provide the spray gun with HVLP air or with HPLV air. In this example, the HVLP air source also provides the air chisels with HVLP air. If the spray gun uses HPVL air, the air chisels may be provided with HVLP air from an air compressor, air turbine, or air blower. When the spray gun uses the airless method of spraying, no air source is necessary for the spray gun; the air chisels may be provided with HVLP air as above.
Also visible in FIG. 5 is the barrel ring 34 which attaches the nozzle units 12 to the spray gun 30, the elongated nozzles 23, and the hose or conduit 21 which provides LPHV air to the nozzle units.
FIG. 6 is a side view of a nozzle unit mounted on a stand. The nozzle unit 12 consisting of an elongated nozzle 23, a bore 10, and a hose 21, is connected by a bore ring 39 to the stand post 64, which is mounted on the stand base 66.
FIG. 7 is a side view of a nozzle unit having a jet venturi pump mounted on a stand. The nozzle unit 12 consisting of an elongated nozzle 23, a bore 10, a jet venturi pump between the bore and the hose 14 which has three visible induction ports 17, and a hose 21, is connected by a bore ring 39 to the stand post 64, which is mounted on the stand base 66.
A nozzle unit having a jet venturi pump, as in FIG. 7, has the additional advantage of respraying any overspray which may reach the jet venturi induction pump. The overspray is induced into the induction ports 17 and resprayed from the elongated nozzle.
FIG. 8 is a top view of a mounting bar having four mounted nozzle units. The nozzle units 12 consisting of elongated nozzles 23, bores 10, and hoses 21 are mounted by bore rings on a mounting bar 60. Other means for attaching the nozzle units to a mounting bar may be used, such as nuts and bolts, screws, etc.
FIG. 9 is a front view of the mounting bar having four mounted nozzle units of FIG. 8. Visible are the mounting bar 60, nozzle units 12, and elongated nozzles 23.
FIG. 10 is a side view of an operator 42 who is spraying a work object 44 using a spray gun 30 having a reservoir 32 and an air hose 31 which is connected to a compressor 40. The work object 44 rests on a horizontal support 48 in a spray area 46. Four nozzle units 12 mounted on a mounting bar 60 are mounted by a attachment bar 62 to the front of the spray area 46. The nozzle units are provided with HVLP air by a hose 21 from the air compressor 40. The nozzle units are mounted close enough to the work object to provide an oriented air curtain which contains and suppresses overspray, thus functioning as air chisels. A second similar group of four air chisels are not visible in FIG. 10 but are visible in FIG. 11.
FIG. 11 is at top view of the scene of FIG. 10. both groups of mounted nozzle unit, the one on the left side 63 and on the right side 64 of the spray gun 30 are shown. Also shown in FIG. 11 is the sprayed material 50 emitted from the spray gun and the air curtains 54 emitted from the nozzle units.
FIG. 12 is a side view of a second embodiment of a spray gun with a nozzle unit attached. In this embodiment a shield 70 is interposed between the nozzle unit 12 and the spray gun 30. The orientation of the shield is approximately parallel to the air curtain. The other elements of the second embodiment spray gun of FIG. 13 are as in FIG. 4. The function of the shield 70 is to direct the flow of HVLP air emitted from the nozzle unit 12 and aid in the repression of bounceback.
FIG. 13 is a diagram showing suppression of bounce back by air chisels in a second embodiment spray gun having shields 70 and 72 between the spray plum 50 and the oriented air curtains 54. The shields 70 and 72 are mounted on the spray gun posts 38. The other elements of the second embodiment spray gun of FIG. 12 are as in FIG. 1. The air curtains 54 are deflected by shields 70 and 72 and directed toward the work surface 46 where they suppress overspray 52. Shields 70 and 72 also act to prevent disruption of air curtains 54 or of spray of atomizable liquid or powder 50 by any air currents 72 which are approximately parallel to the work surface 46. Such air currents 72 are redirected by shield 70 and incorporated into air curtain 54.
It will be apparent to those skilled in the art that the examples and embodiments described herein are by way of illustration and not of limitation, and that other examples may be used without departing from the spirit and scope of the present invention, as set forth in the appended claims.
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An apparatus is disclosed which uses a high volume low pressure air curtain in an "air chisel" to inhibit and reduce the bounceback and overspray of material sprayed on a work surface. The air chisel directs a lateral air curtain along each side of a plume of sprayed material parallel to the long axis of the plume and directed toward the contact of plume and work surface. An air chisel may be attached to a spray gun or may be mounted on a stand adjacent to the work surface. Any source of high volume low pressure air may serve to provide air to an air chisel.
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PRIORITY CLAIM AND CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of PCT Application No. PCT/US01/04376 filed Feb. 9, 2001, which was published in English on Aug. 16, 2001 as WO 01/58905. The PCT Application claims priority from U.S. Provisional Application Ser. No. 60/181,795, filed 11 Feb. 2000. The disclosures of these applications are hereby incorporated herein by reference.
STATEMENT OF GOVERNMENT SUPPORT
This invention was supported by funding from the Government of the United States of America, by virtue of Grant No. GM34167 awarded by the National Institutes of Health. Thus, the Governmant may have certain rights in this invention.
BACKGROUND OF THE INVENTION
Ecteinascidin 743 (1, Et 743) is an exceedingly potent marine-derived antitumor agent 1 which is now being studied in various clinics with human patients. 2 Because this compound is not sufficiently available from the natural source, the tunicate Ecteinascidia turbinata , it is being produced industrially by the totally synthetic route described in 1996. 3 More recently a structural analog of Et 743, compound 2 (phthalascidin, Pt 650) has been found to exhibit antitumor activity essentially indistinguishable from 1. 4
Both 1 and 2 are synthesized from building blocks 3 and 4 3 via a common pentacyclic intermediate 5.
The synthesis of 5 was accomplished originally 3 from building blocks 3a and 4 in six steps with an overall yield of 35% (average yield per step of ca. 84%). Because the industrial syntheses of 1 and/or 2 would eventually have to be produced economically on a multi-kilogram scale, we sought to find a more efficient and reproducible alternative route from 2 and 3 to 5.
SUMMARY OF THE INVENTION
One embodiment of the present invention is thus directed to a new synthetic process for the preparation of the intermediate compound 5 which is simpler to carry out than the original and which proceeds from 3b 3 +4 to 5 in six steps with an overall yield of 57% (average yield per step of nearly 92%). The preferred process for the synthesis of pentacycle 5 is summarized below in Scheme 1. 5
The second preferred embodiment of the present invention entails a new synthetic process for converting the pentacycle compound 5 to phthalascidin 2, which proceeds smoothly and in excellent yield (average yield per step 90.8%). This process is outlined below in Scheme 2.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
As illustrated above in Scheme 1, a solution of azeotropically dried (C 7 H 8 B THF) amino lactone 4 in THF at 0 EC was treated dropwise with an acylating reagent prepared from the acid 3b 3 (1.03 equiv), 1-hydroxy-7-azabenzo-triazole (HOAT, 1.08 equiv), 2-chloro-1,3-dimethylimidazolidinium hexafluorophosphate (CIP, 1.03 equiv) and triethylamine (2.06 equiv) in CH 2 Cl 2 solution at 0 EC. 6
The coupling product 6, which was obtained by extractive workup, was allylated without further purification by treatment in DMF solution at 23 EC with excess allyl bromide and 1.09 equiv of Cs 2 CO 3 to give amide 7 in 81% overall yield from 3a and 4 after flash chromatography on silica gel.
Selective reduction of the lactone function of 7 to the corresponding lactol (8) was effected by reaction with 1.1 equiv of lithium diethoxyaluminum hydride (LiAlH 2 (OEt) 2 ) in ether at −78E for 15 min in 95% yield. 7,8 Desilylation of 8 to 9 and cyclization of 9 (without purification) using 0.6 M triflic acid in 3:2H 2 O B CF 3 CH 2 OH at 45 EC for 7 h produced the pentacyclic product 10 in 89% overall yield from 8.
Finally, the lactam function of 10 could be reduced cleanly by treatment with 4 equiv of LiAlH 2 (OEt) 2 in THF at 0 EC for 35 min to the corresponding cyclic aminal which upon exposure to HCN provided the pentacyclic amino nitrile 5 in 87% overall yield from 10 after flash chromatography on silica gel. 9
The synthesis of 5 which is outlined in Scheme 1 and described above is advantageous relative to the originally used synthetic pathway 3 not only because of the substantially greater overall yield (57 vs 35%), but also because of the simplicity and reproducibility of the individual steps, especially the amide coupling (2a+3→6) and the internal Pictet-Spengler cyclization (9→10). In addition no difficulties have been encountered either in product purification or scale up.
A critical element to the success of the sequence shown in Scheme 1 was the high efficiency and selectivity of LiAlH 2 (OEt) 2 for the two reduction steps: 8→9 and 10→5, which suggest that this reagent can be used to advantage in synthesis much more frequently than it has been previously.
In Scheme 2, the pentacyclic triol 5 was first converted to the phenolic monotriflate 11 (step not shown) by treatment with 1.1 equiv of PhNTf 2 (McMurry reagent), 2 equiv of Et 3 N and 0.2 equiv of 4-dimethyl-aminopyridine in CH 2 Cl 2 at −30 EC for 38 h (74%). Conversion of 11 to the mono t-butyldimethylsilyl (TBS) ether 12 and etherification with methoxymethyl chloride (MOMCl) produced 23 in high yield.
Cleavage of the N-allyloxycarbonyl and O-allyl groups in 13 gave the secondary amine 14 (94%) which was N-methylated to 15 and C-methylated to 16. Acetylation of phenol 16 produced the corresponding acetate 17 which upon desilylation formed the primary alcohol 18. Mitsunobu displacement of the primary hydroxyl of 18 produced the phthalimide 19 which upon acid-catalyzed cleavage of the methoxymethyl ether provided pure phthalascidin 2.
Since the original synthetic route to Et 743 (1) has proved to be acceptable for large scale synthesis, it is our expectation that the improved process described herein will be even more useful, as will the new route to phthalascidin (2). 4 Because phthalascidin is more stable than ecteinascidin 743 and considerably easier to make, it may prove to be a more practical therapeutic agent.
The present invention will be further illustrated with reference to the following examples which aid in the understanding of the present invention, but which are not to be construed as limitations thereof. All percentages reported herein, unless otherwise specified, are percent by weight. All temperatures are expressed in degrees Celsius.
EXAMPLE 1
The acid (224 mg, 0.400 mmol) was dissolved in distilled acetic acid (5.0 mL) and 0.2 N HCl 10 (1.5 mL) and heated to 110 EC. After 5.5 h, the reaction was concentrated in vacuo and dried by repetitive in vacuo azeotropic concentration with toluene (3×10 mL) and dissolved in DMF (1.0 mL). tert-Butyldimethylsilyl chloride (304 mg, 2.03 mmol) and imidazole (152 mg, 2.24 mmol) were added as solids and the mixture was stirred at 23 EC for 2 h. The reaction was quenched with 2:1 acetic acid-water (1.5 mL) and stirred for 30 min. The reaction was poured into 0.5 M aqueous oxalic acid (100 mL) and extracted with 3:7 ethyl acetate-hexane (2×100 mL). The combined organic layers were washed with saturated aqueous sodium chloride (100 mL), dried over sodium sulfate, filtered and concentrated in vacuo. The residue was purified by flash column chromatography (100 mL silica gel, gradient 1:1 ethyl acetate-hexane to 0.1% acetic acid-ethyl acetate) to afford the desired product as a substantially pure clear viscous oil (204.6 mg, 95%).
R ƒ 0.10 (ethyl acetate); 1 H NMR (400 MHz, CDCl 3 ) δ 10.25 (br s, 1H), 6.32 (s, 2H), 5.90 (ddt, J=17.0, 10.6, 5.4 Hz, 1H), 5.28 (d, J=17.1 Hz, 1H), 5.20 (d, J=10.4 Hz, 1H), 5.11 (d, J=8.0 Hz, 1H), 4.61-4.57 (m, 1H), 4.55 (d, J=5.5 2H), 3.70 (s, 3H), 3.04 (dd, J=14.0, 5.1 Hz, 1H), 2.93 (dd, J=14.0, 6.4 Hz, 1H), 0.99 (s, 18H), 0.15 (s, 12H); 13 C NMR (101 MHz, CDCl 3 ) δ 176.3, 155.7, 149.9, 142.2, 132.5, 130.5, 118.0, 115.6, 66.1, 60.0, 54.5, 37.2, 25.8, 18.4, −4.6; FTIR (neat) 3438 (m), 3331 (m), 3088 (m v br), 2956 (s), 2931 (s), 2894 (s), 2863 (s), 1719 (s), 1578 (s), 1496 (s), 1435 (s), 1361 (s), 1253 (s), 1231 (s), 1093 (s), 1010 (m), 938 (w), 831 (s) cm −1 ; HPLC analysis was performed after derivatization using diazomethane to make the methyl ester (ChiralPak AD, 1% isopropanol in hexane, flow rate: 1.0 mL/min, λ=226 nm), 96% ee, R T =11.1 min (major), 9.2 min (minor); HRMS (FAB), [m+H]/z calc=d for C 26 H 46 O 7 NSi 2 : 540.2813, found 540.2823; [α] D 23 +18.8E (c 1.0, methylene chloride).
Example 2
The amine (100.0 mg, 0.380 mmol) was dried by in vacuo azeotropic concentration with 2:3 THF-toluene (5 mL) and dissolved in THF (1.5 mL) and cooled to 0 EC. In a different flask, the acid (211.7 mg, 0.392 mmol) and 1-hydroxy-7-azabenzotriazole (55.8 mg, 0.410 mmol) were dried by in vacuo azeotropic concentration with 2:3 THF-toluene (5 mL) and dissolved in methylene chloride (1.5 mL). To this flask was added 2-chloro-1,3-dimethylimidazolidinium hexafluorophosphate (109.3 mg, 0.392 mmol) as a solid and triethylamine (109 μL, 0.782 mmol) via syringe to afford a clear dark yellow solution. This mixture was stirred at 23 EC for 3 min and then cooled to 0 EC and cannulated into the flask containing the amine. Methylene chloride (1.5 mL) was used to transfer the remains in the flask. The golden solution was stirred at 0 EC for 18 h, warmed to 23 EC and stirred an additional 6 h. The reaction was diluted with ethyl acetate (6 mL) and partially concentrated in vacuo to remove methylene chloride. The solution was poured into 0.5 M aqueous acetic acid (100 mL), extracted with 3:7 ethyl acetate-hexane (100 mL) and washed with saturated aqueous sodium bicarbonate (100 mL). The aqueous layers were re-extracted 3:7 ethyl acetate-hexane (100 mL) and the combined organic layers were dried over sodium sulfate, filtered and concentrated in vacuo to afford a clear film (˜300 mg). This residue was used without further purification. The material can be purified by flash column chromatography (100 mL silica gel, gradient 1:3 to 2:3 ethyl acetate-hexane), however only a 50% yield was obtained presumably due to silica gel promoted decomposition.
R ƒ 0.36 (2:3 ethyl acetate-hexane); 1 H NMR (400 MHz, CDCl 3 ) δ (mixture of carbamate and amide rotamers) 6.35 (s, 1H), 6.20 (s, 1H), 5.91-5.81 (m, 3H), 5.94-5.59 (m, 1.5H), 5.42 (d, J=3.3 Hz, 0.5H), 5.30-5.03 (m, 3H), 4.74-4.63 (m, 1H), 4.60 (dd, J=10.8, 3.1 Hz, 0.5H), 4.53 (br s, 1H), 4.45 (d, J=5.1 Hz, 1H), 4.36 (d, J=10.6 Hz, 0.5H), 4.19 (d, J=10.6 Hz, 0.5H), 3.68 (s, 1.5H), 3.61 (s, 1.5H), 3.56 (d, J=8.4 Hz, 0.5H), 3.03-2.90 (m, 3H), 2.79 (dd, J=13.0, 4.6 Hz, 0.5H), 2.24 (d, J=16.0 Hz, 0.5H), 2.06 (br s, 3H), 0.99 (s, 9H), 0.91 (s, 9H), 0.15 (s, 6H), 0.06 (s, 6H); 13C NMR (101 MHz, CDCl 3 ) δ (mixture of carbamate and amide rotamers) 169.2, 169.0, 167.9, 167.5, 155.6, 155.2, 150.1, 149.7, 146.9, 146.5, 145.1, 145.0, 142.1, 141.7, 136.8, 136.2, 132.4, 132.3, 130.7, 130.3, 117.9, 117.8, 115.5, 115.3, 111.3, 110.9, 110.5, 108.1, 107.8, 101.4, 73.0, 66.1, 65.9, 60.0, 59.9, 54.7, 52.2, 51.9, 51.0, 47.6, 43.2, 39.6, 38.5, 29.1, 27.4, 25.8, 25.7, 18.4, 18.3, 8.9, −4.53, −4.56, −4.65, −4.74; FTIR (neat) 3406 (w br), 3319 (w br), 2956 (m), 2931 (m), 2894 (w), 2856 (m), 1725 (m), 1644 (m), 1575 (m), 1494 (m), 1463 (m), 1431 (s), 1356(w), 1231 (s), 1163 (w), 1094(s), 1044 (m), 1013 (m), 831 (s) cm −1 ; HRMS (ESI), [m+H]/z calc=d for C 39 H 57 O 11 N 2 Si 2 : 785.3501, found 785.3469; [α] D 24 +20.5E (c 1.0, chloroform).
Example 3
Phenol (˜300 mg, 0.380 mmol) was dried by in vacuo azeotropic concentration with toluene (5 mL) and dissolved in DMF (15 mL). Allyl bromide (330 μL, 3.82 mmol) was added via syringe and cesium carbonate (134.7 mg, 0.413 mmol), gently flame dried in vacuo, was added as a solid and the reaction was stirred at 23 EC for 2 h. The reaction was poured into water (300 mL), extracted with 1:4 ethyl acetate-hexane (2×150 mL), washed with saturated aqueous sodium chloride (100 mL), dried over sodium sulfate, filtered and concentrated in vacuo. The residue was purified by flash column chromatography (75 mL silica gel, gradient 1:4 to 3:7 ethyl acetate-hexane) to afford the desired product as a substantially pure clear film (252.9 mg, 81% over two steps). This material was also found to be unstable to silica gel and so a rapid chromatography was critical to obtain the observed yield.
R ƒ 0.47 (2:3 ethyl acetate-hexane); 1 H NMR (400 MHz, CDCl 3 ) δ (mixture of carbamate and amide rotamers) 6.35 (s, 1H), 6.20 (s, 1H), 6.03-5.78 (m, 5H), 5.52-5.44 (m, 1.4H), 5.38-5.33 (m, 1H), 5.31-5.13 (m, 3.6H), 4.73-4.59 (m, 1.4H), 4.55 (d, J=5.1 Hz, 1H), 4.48 (d, J=5.1 Hz, 1H), 4.34 (d, J=10.6 Hz, 0.6H), 4.24-4.04 (m, 3H), 3.68 (s, 1.5H), 3.60 (s, 1.5H), 3.54 (d, J=8.8 Hz, 0.4H), 2.90 (m, 2.6H), 2.77 (dd, J=12.8, 4.8 Hz, 0.6H), 2.34 (m, 0.4H), 2.12 (s, 1.5H), 2.09 (s, 1.5H), 0.99 (s, 9H), 0.92 (s, 9H), 0.16 (s, 6H), 0.07 (s, 3H), 0.05 (s, 3H); 13 C NMR (101 MHz, CDCl 3 ) δ (mixture of carbamate and amide rotamers) 169.2, 168.8, 167.4, 167.1, 155.5, 155.1, 150.2, 150.0, 149.8, 145.5, 145.3, 142.2, 141.9, 139.2, 138.8, 133.4, 133.2, 132.4, 130.6, 130.2, 118.3, 118.0, 117.9, 117.8, 117.7, 117.2, 115.5, 115.2, 114.3, 113.9, 111.1, 110.9, 101.8, 101.7, 73.8, 73.7, 72.8, 66.1, 65.9, 60.04, 59.99, 54.9, 52.1, 51.9, 51.1, 47.7, 43.3, 39.8, 38.5, 29.6, 27.9, 25.8, 25.7, 18.4, 18.3, 9.6, 9.4, −4.51, −4.54, −4.6, −4.7; FTIR (neat) 3306 (w br), 2956 (m), 2931 (m), 2898 (m), 2856 (m), 1750 (m), 1719 (m), 1650 (m), 1575 (m), 1494 (m), 1431 (s), 1363 (m), 1250 (m), 1231 (m), 1163 (w), 1094 (s), 1044 (m), 1013 (m), 944 (w), 919 (w), 831 (s) cm −1 ; HRMS (ESI), [m+H]/z calc=d for C 42 H 61 O 11 N 2 Si 2 : 825.3814, found 825.3788; [α] D 24 +21.7E (c 1.0, chloroform).
Example 4
The lactone (354.1 mg, 0.429 mmol) was dried by in vacuo azeotropic concentration with toluene (10 mL), dissolved in diethyl ether (8.0 mL) and cooled to −78 EC in a dry ice-acetone bath. A 0.10 M solution of LiAlH 2 (OEt) 2 (4.7 mL, 0.47 mmol) 11 was added drop-wise down the side of the flask over 2 min. The reaction was stirred at −78 EC for 15 min and then the light yellow solution was poured in 0.1 N HCl (50 mL) at 0 EC while rapidly stirring. This solution was extracted with diethyl ether (2×75 mL), washed with saturated aqueous sodium chloride (50 mL), dried over sodium sulfate, filtered and concentrated in vacuo. The residue was purified by flash column chromatography (150 mL silica gel, gradient 3:7 to 2:3 to 1:1 ethyl acetate-hexane) to afford the desired product as a substantially pure clear film (339.0 mg, 95%).
R ƒ 0.20 (2:3 ethyl acetate-hexane); 1 H NMR (400 MHz, CDCl 3 ) δ (mixture of anomers, carbamate and amide rotamers) 6.43 (s, 0.2H), 6.37 (s, 0.2H), 6.16 (s, 1.4H), 6.15 (s, 0.2H), 6.05-5.80 (m, 4.4H), 5.82-5.59 (m, 1.2H), 5.41-5.14 (m 3.8H), 5.07-4.95 (m, 1.5H), 4.85-4.76 (m, 1.6H), 4.61-4.46 (m, 2.2H), 4.26-4.41 (m, 3.8H), 4.10-3.75 (m, 0.5H), 3.68 (s, 0.3H), 3.66 (s, 0.3H), 3.63 (s, 2.4H), 3.37 (d, J=11.0 Hz, 0.8H), 3.33-2.94 (m, 0.7H), 2.90-2.65 (m, 2.8H), 2.35 (dd, J=17.7 7.5 Hz, 0.7H), 2.12 (s, 0.3H), 2.11 (s, 0.3H), 2.09 (s, 2.4H), 1.05 (s, 4.5H), 0.92 (s, 13.5H), 0.16 (s, 3H), 0.07 (s, 4.5H), 0.04 (s, 4.5H); 13 C NMR (101 MHz, CDCl 3 ) δ (mixture of anomers, carbamate and amide rotamers) 169.8, 156.1, 149.6, 149.2, 144.6, 141.7, 138.3, 133.8, 132.2, 130.2, 118.9, 118.0, 116.7, 115.1, 113.4, 112.5, 101.3, 93.4, 73.2, 66.2, 62.4, 60.1, 53.6, 51.4, 44.6, 38.5, 26.5, 25.9, 25.8, 18.5, 18.3, 9.5, −4.56, −4.59; FTIR (neat) 3406 (m br), 3325 (m br), 2956 (m), 2931 (m), 2894 (m), 2856 (m), 1714 (m), 1644 (m), 1578 (m), 1496 (m), 1433 (s), 1360 (m), 1255 (m), 1234 (m), 1095 (s), 1044 (m), 1013 (m), 941 (w), 830 (s) cm −1 ; HRMS (ESI), [m+H]/z calc=d for C 42 H 63 O 11 N 2 Si 2 : 827.3970, found 827.4009; [α] D 25 −1.5E (c 1.0, chloroform).
Example 5
The lactol (316.3 mg, 0.382 mmol) was dissolved in nitrogen purged methanol (3.8 mL). Anhydrous potassium fluoride (110.3 mg, 1.90 mmol) was added as a solid and the vessel was pumped/purged with nitrogen. The reaction was stirred at 23 EC for 30 min and the light pink mixture was diluted with toluene (5 mL) and concentrated in vacuo. The residue was dissolved in nitrogen purged 2,2,2-trifluoroethanol (15 mL) and butylated hydroxytoluene (4.3 mg, 0.02 mmol) was added as a solid. The flask was charged with 1.0 M aqueous trifluoromethanesulfonic acid 12 (23 mL) and the vessel was again pumped/purged with nitrogen. The solution was stirred at 45 EC in an oil bath for 7 h. The mixture was partially concentrated in vacuo, to remove the alcohol, and poured into 80% saturated aqueous sodium chloride (100 mL), extracted with ethyl acetate (2×100 mL), washed with saturated aqueous sodium chloride (50 mL), dried over sodium sulfate, filtered and concentrated in vacuo. The residue was purified by flash column chromatography (100 mL silica gel, 5:95 methanol-methylene chloride) to afford the desired product as a substantially pure white solid (198.5 mg, 89%). Crystals were obtained from toluene.
M.p.: 130 EC (dec.); R ƒ 0.11 (5:95 methanol-methylene chloride); 1 H NMR (400 MHz, Acetone-d 6 ) δ (mixture of carbamate rotamers) 8.34 (br s, 1H), 8.32 (br s, 1H), 6.31 (d, J=4.4 Hz, 1H), 6.14 (m, 1H), 5.97 (s, 1H), 5.97-5.90 (m, 1H), 5.90 (s, 1H), 5.68 (m, 1H), 5.42-5.37 (m, 2H), 5.31-5.22 (m, 2H), 5.18-5.1 (m, 1H), 4.85 (d, J=6.6 Hz, 1H), 4.65-4.55 (m, 2H), 4.38-4.34 (m, 1H), 4.26-4.22 (m, 1H), 3.89-3.86 (m, 1H), 3.77 (s, 3H), 3.71 (m, 1H), 3.57 (d, J=15.0 Hz, 1H), 3.48-3.43 (m, 1H), 3.25-3.13 (m, 2H), 3.00 (d, J=16.8 Hz, 1H), 2.34 (m, 1H), 2.11 (s, 3H); 13C NMR (101 MHz, Acetone-d 6 ) δ (mixture of carbamate rotamers) 169.4, 169.2, 153.8, 153.7, 150.6, 149.3, 148.2, 148.0, 145.5, 141.0, 135.1, 134.5, 133.9, 130.2, 130.1, 122.4, 117.9, 117.8, 117.7, 117.5, 114.2, 112.7, 111.0, 110.8, 108.4, 108.3, 102.1, 75.4, 66.74, 66.69, 65.6, 61.6, 61.2, 60.9, 54.3, 53.5, 52.9, 50.1, 49.3, 34.1, 33.6, 27.5, 9.7; FTIR (KBr) 3400 (s br), 2944 (m), 2881 (m), 1700 (s), 1639 (s), 1501 (w), 1463 (s), 1435 (s), 1356 (m), 1320 (m), 1288 (m), 1269 (m), 1238 (m), 1213 (m), 1166 (m), 1102 (s), 1065 (s), 1030 (m), 999 (m), 938 (m), 807 (w) cm −1 ; HRMS (ESI), [m+H]/z calc=d for C 30 H 33 O 10 N 2 : 581.2135, found 581.2112; [α] D 25 −27.2E (c0.50, methanol).
Example 6
The amide (198.0 mg, 0.341 mmol) was dried by in vacuo azeotropic concentration with toluene (10 mL), dissolved in THF (10 mL) and cooled to 0 EC. A 0.20 M solution of LiAlH 2 (OEt) 2 (6.8 mL, 1.36 mmol) 13 was added drop-wise over 10 min. The reaction was stirred at 0 EC for 35 min at afford the carbinolamine, R ƒ 0.59 (4:1 ethyl acetate-hexane). Acetic acid (425 μL, 7.44 mmol) was added first in order to quench the reaction. Then 4.8 M aqueous potassium cyanide (425 μL, 2.04 mmol), anhydrous sodium sulfate (2.5 g, 17.6 mmol) and Celite 7 (6 mL) were added to affect the conversion to the amino-nitrile and to precipitate the aluminum salts. Bubbling was observed and after 5 min the reaction was warmed to 23 EC and stirred for 7 h. The suspension was filtered through a pad of Celite 7 , eluting with ethyl acetate (100 mL). This solution was concentrated in vacuo and purified by flash column chromatography (100 mL silica gel, 2:1 ethyl acetate-hexane) to afford the desired product as a substantially pure white foam (175.6 mg, 87%).
R ƒ 0.31 (4:1 ethyl acetate-hexane); 1 H NMR (400 MHz, CDCl 3 ) δ (mixture of carbamate rotamers) 6.43 (br s, 0.6H), 6.26 (s, 0.4H), 6.24 (s, 0.6H), 6.20 (s, 0.4H), 6.07-6.00 (m, 1H), 5.97-5.82 (m, 4H), 5.61 (s, 0.6H), 5.52 (s, 0.4H), 5.37-5.17 (m, 3H), 4.90 (d, J=7.8 Hz, 0.4H), 4.84 (d, J=8.3 Hz, 0.6H), 4.73-4.60 (m, 2H), 4.16-4.08 (m, 2.6H), 3.97-3.94 (m, 1.4H), 3.77 (s, 1.2H), 3.68-3.61 (m, 3.62 (s, 1.8H), 3.49-3.36 (m, 1H), 3.29-3.19 (m, 3H), 2.76-2.69 (m, 1H), 2.11 (s, 1.8H), 2.08 (s, 1.2H), 2.00-1.83 (m, 2H); 13 C NMR (101 MHz, CDCl 3 ) δ (mixture of carbamate rotamers) 154.3, 153.8, 148.4, 148.34, 148.26, 146.2, 145.9, 144.3, 138.8, 133.62, 133.56, 132.7, 132.2, 130.7, 130.3, 120.5, 120.3, 117.9, 117.8, 117.4, 117.2, 116.3, 112.6, 112.5, 112.1, 111.9, 107.2, 106.4, 101.1, 74.5, 74.0, 66.7, 66.5, 64.5, 64.3, 60.8, 60.5, 59.1, 58.9, 58.0, 56.7, 56.6, 49.9, 49.4, 48.9, 48.7, 31.2, 30.5, 29.7, 25.9, 9.43, 9.35; FTIR (neat) 3369 (m br), 2931 (m br), 1688 (m), 1500 (w), 1463 (m) 1431 (s), 1375 (m), 1325 (m), 1294 (m), 1269 (m), 1106 (s), 1063 (m), 994 (m), 956 (w) cm −1 ; HRMS (ESI), [m+H]/z calc=d for C 31 H 34 O 9 N 3 : 592.2295, found 592.2316; [α] D 25 +30.4E (c 1.0, chloroform).
Example 7
The phenol (170.0 mg, 0.287 mmol) was dried by in vacuo azeotropic concentration with toluene (10 mL) and dissolved in methylene chloride (3.0 mL). Triethylamine (80 μL, 0.574 mmol) and 4-dimethylaminopyridine (7.0 mg, 0.0574 mmol) were added and the solution was cooled to −30 EC in a dry ice-acetonitrile bath. N-Phenyltrifluoromethanesulfonimide (113.5 mg, 0.318 mmol) was added as a solid and the reaction was stirred at B 30 EC in a Cryobath 7 for 38 h. The mixture was poured into 1:1 saturated aqueous sodium bicarbonate-saturated aqueous sodium chloride (100 mL), extracted with methylene chloride (2×75 mL), dried over sodium sulfate, filtered and concentrated in vacuo. The residue was purified by flash column chromatography (100 mL silica gel, gradient 2:3 to 3:4 ethyl acetate-hexane) to afford the desired product as a substantially pure clear film (153.4 mg, 74%).
R ƒ 0.18 (2:3 ethyl acetate-hexane); 1 H NMR (400 MHz, CDCl 3 ) δ (mixture of carbamate rotamers) 7.16 (s, 0.6H), 6.63 (s, 0.4H), 6.60 (s, 0.6H), 6.45 (s, 0.4H), 6.08-5.86 (m, 4H), 5.74 (m, 0.6H), 5.59 (m, 0.4H), 5.40-5.16 (m, 4H), 4.96-4.89 (m, 1H), 4.74-4.60 (m, 3H), 4.26 (m, 1H), 4.19-4.15 (m, 2H), 4.00 (m, 1H), 3.89 (s, 1.2H), 3.83 (s, 1.8H), 3.66-3.64 (m, 1H), 3.39-3.24 (m, 4H), 2.91-2.83 (m 2.11 (s, 1.2H), 2.05 (s, 1.8H), 1.86-1.78 (m, 1H); 13 C NMR (101 MHz, CDCl 3 ) δ (mixture of carbamate rotamers) 154.0, 153.9, 148.6, 148.4, 147.3, 146.6, 144.7, 144.5, 141.3, 141.0, 139.1, 138.9, 136.9, 136.7, 133.7, 132.2, 132.1, 131.6, 129.4, 127.0, 123.0, 121.5, 121.3, 119.9, 118.5 (q, J=321 Hz, CF 3 ), 118.2, 117.7, 117.6, 117.4, 116.3, 116.1, 112.6, 112.3, 112.1, 112.0, 101.3, 101.2, 74.5, 66.9, 66.7, 65.7, 65.5, 62.0, 61.9, 59.54, 59.48, 58.6, 56.5, 49.8, 49.3, 49.0, 48.4, 31.0, 30.4, 26.1, 26.0, 9.5, 9.4; 19 F NMR (376 MHz, BF 3 $OEt 2 standard set at B 153.0 ppm, CDCl 3 ) δ (mixture of carbamate rotamers) B 74.02, −74.01; FTIR (neat) 3325 (w br), 2949 (w br), 1688 (m), 1588 (w), 1500 (m), 1425 (s), 1319 (m), 1288 (m), 1256 (m), 1213 (s), 1138 (s), 1106 (m), 1038 (m), 988 (m), 875 (w) cm −1 ; HRMS (ESI), [m+H]/z calc=d for C 32 H 33 O 11 N 3 SF 3 : 724.1788, found 724.1803; [α] D 26 +34.3E (c 1.0, chloroform).
Footnotes:
The following publications provide background information and are hereby incorporated herein by reference.
(1) The pioneering research in this area is due to Prof. Kenneth L. Rinehart and his group. See, (a) Rinehart, K. L.; Shield, L. S. in Topics in Pharmaceutical Sciences , eds. Breimer, D. D.; Crommelin, D. J. A.; Midha, K. K. (Amsterdam Medical Press, Noordwijk, The Netherlands), 1989, pp. 613. (b) Rinehart, K. L.; Holt, T. G.; Fregeau, N. L.; Keifer, P. A.; Wilson, G. R.; Perun, T. J., Jr.; Sakai, R.; Thompson, A. G.; Stroh, J. G.; Shield, L. S.; Seigler, D. S.; Li, L. H.; Martin, D. G.; Grimmelikhuijzen, C. J. P.; Gäde, G. J. Nat. Prod. 1990, 53, 771. (c) Rinehart, K. L.; Sakai, R; Holt, T. G.; Fregeau, N. L.; Perun, T. J., Jr.; Seigler, D. S.; Wilson, G. R.; Shield, L. S. Pure Appl. Chem. 1990, 62, 1277. (d) Rinehart, K. L.; Holt, T. G.; Fregeau, N. L.; Stroh, J. G.; Keifer, P. A.; Sun, F.; Li, L. H.; Martin, D. G. J. Org. Chem. 1990, 55, 4512. (e) Wright, A. E.; Forleo, D. A.; Gunawardana, G. P.; Gunasekera, S. P.; Koehn, F. E.; McConnell, O. J. J. Org. Chem. 1990, 55, 4508. (f) Sakai, R.; Rinehart, K. L.; Guan, Y.; Wang, H. J. Proc. Natl. Acad. Sci. USA 1992, 89, 11456.
(2) (a) Business Week, Sep. 13, 1999, p. 22. (b) Science 1994, 266, 1324.
(3) Corey, E. J.; Gin, D. Y.; Kania, R. J. Am. Chem. Soc. 1996, 118, 9202.
(4) Martinez, E. J.; Owa, T.; Schreiber, S. L.; Corey, E. J. Proc. Natl. Acad. Sci. USA 1999, 96, 3496.
(5) See Myers, A. G.; Kung, D. W. J. Am. Chem. Soc. 1999, 121, 10828 for a different approach to the synthesis of structures such as 5.
(6) For carboxylic acid B amine coupling methodology using CIP, see: (a) Akaji, K.; Kuriyama, N.; Kimura, T.; Fujiwara, Y.; Kiso, Y. Tetrahedron Lett. 1992, 33, 3177. (b) Akaji, K.; Kuriyama, N.; Kiso, Y. Tetrahedron Lett. 1994, 35, 3315. (c) Akaji, K.; Kuriyama, N.; Kiso, Y. J. Org. Chem. 1996, 61, 3350.
(7) The reagent LiAlH 2 (OEt) 2 was prepared by the addition of a 1.0 M solution of LiAlH 4 in ether to a solution of 1 equiv of ethyl acetate at 0 EC and stirring at 0 EC for 2 h just before use; see: Brown, H. C.; Tsukamoto, A. J. Am. Chem. Soc. 1964, 86, 1089.
(8) For general reviews on reduction of lactones see: (a) Brown, H. C.; Krishnamurthy, S. Tetrahedron, 1979, 35, 567. (b) Cha, J. S. Org. Prep. Proc. Int, 1989, 21(4), 451. (c) Seyden-Penne, J. Reduction by the Alumino - and Borohydrides in Organic Synthesis; 2nd Ed.; Wiley-VCH: New York, 1997; Section 3.2.5.
(9) For general references on amide reduction by hydride reagents see ref. 7 and also Myers, A. G.; Yang, B. H.; Chen, H.; Gleason, J. L. J. Am. Chem. Soc. 1994, 116, 9361.
(10) Made from nitrogen purged water.
(11) This reagent was made by adding a 1.0 M solution of lithium aluminum hydride in Et 2 O (1 equiv) to a solution of ethyl acetate (1 equiv) in Et 2 O at 0 EC. The mixture was stirred at 0 EC for 2 h and a portion of this reagent was used for the reduction of the lactol. Brown, H. C.; Tsukamoto, A. J. Am. Chem. Soc. 1964, 86, 1089.
(12) Made from nitrogen purged water.
(13) See the reference cited in footnote 11.
The present invention has been described in detail, including the preferred embodiments thereof. However, it will be appreciated that those skilled in the art, upon consideration of the present disclosure, may make modifications and/or improvements on this invention and still be within the scope and spirit of this invention as set forth in the following claims.
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An efficient process is described for the synthesis of 5, a key intermediate for the synthesis of the potent antitumor agents ecteinascidin 743 (1) and phthalascidin (2) from the readily available building blocks 3b and 4.
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FIELD OF THE INVENTION
[0001] The present invention relates to a disazo compound as a reactive dye and a method of dyeing cellulosic fibers using this compound. Further, the present invention relates to a reactive dye composition and a dyeing method for dyeing cellulose or cellulose-containing fibers using a reactive dye.
BACKGROUND OF THE INVENTION
[0002] Various reactive dyes have been known. They have been widely used for dyeing cellulosic fibers. The reactive dyes have reactive groups such as monochloro-triazinyl, monofluoro-triazinyl, fluoro-chloro-pyrimidinyl, dichloro-quinoxazinyl, vinylsulfonyl, sulfato-ethylsulfonyl and the like. For dyeing, the reactive dye is used in the presence of an acid binder such as sodium carbonate, sodium hydroxide, sodium metasilicate and the like in a dyeing bath having a pH of 10 or higher and a temperature of 100° C. or less. The acid binder is often added stepwise during a dyeing step in order to avoid problems such as unlevel dyeing, lowering in color yield due to hydrolysis and the like.
[0003] On the other hand, cellulose-containing blended fibers, especially blended cotton/polyester fibers are commercially employed in large quantities since they give comfortable clothes.
[0004] A disperse dye used for dyeing polyester fibers is generally used in a dye bath having an acid to neutral pH and a temperature of about 100 to 140° C. in order to avoid its decomposition and alteration. These dyeing conditions of a disperse dye do not agree with those of a reactive dye. Therefore, when blended fibers are dyed, a two bath method wherein respective fibers are independently treated in respective dye bath and an one bath/two step method wherein both fibers are successively treated in one dye bath while sliding dying conditions for each fibers.
[0005] For purposes of reducing a dyeing time, saving energy, simplifying dyeing operations and the like, a reasonable dyeing method wherein there is no need for controlling a delicate and complicated addition of an agent during a dyeing step has been desired. And, in the dyeing of blended polyester/cotton fibers, an efficient one bath/one step dyeing method wherein both fibers are dyed simultaneously in one dye bath is desired. This one bath/one step dyeing method is sometime referred to as “one bath dyeing method”. A reactive dye used in this method should have a stability without causing a decomposition and a high dyeing property under conditions of dyeing polyester fibers with a disperse dye, that is, in a dye bath having an acidic to neutral pH and a temperature of 100 to 140° C.
[0006] Some reactive dyes having the above properties have been proposed. Yellow reactive dyes relating to the present invention can be exemplified in, for example, JP-A-60-086168 (1985), JP-A-01-308460 (1989) and the like. However, the dyes described in these patents have not always satisfactory properties. For example, the dyes do not show sufficient dyeing property over a relatively low temperature range around 100° C. and therefore a high color yield is not attained. Problems such as color breakup and unlevel dyeing upon dyeing using a mixed dye comprising a reactive dye and other dye are observed so that a formulation compatibility, a reproducibility and the like are not still satisfactory. Thus, the development of a yellow reactive dye which always shows a high dyeing property, has a good reproducibility and excellent fastnesses in various aspects such as a fastness to light, a fastness to chlorinated water, a fastness to washing and the like, and does not invite problems such as thermal discoloration, phototropy and the like is strongly desired.
[0007] In addition, in a mixed dye comprising a yellow reactive dye together with a red reactive dye and/or a blue reactive dye, reactive dyes having a reactive groups such as carboxypyridinio-triazinyl group, for example C.I. Reactive Yellow 162, 163, 178; C.I. Reactive Red 221; C.I. Reactive Blue 216, 217; and the like have been used.
[0008] When a mixed dye comprising the above known reactive dye is used for dyeing, however, many problems such as a poor dyeing reproducibility and an unlevel dyeing property caused by the difference in dyeing property of dyes to be mixed, a color transfer (migration) during a drying step caused by a poor washing of a non-fixed dye, and the like are found.
[0009] Thus, in a mixed dye comprising a yellow reactive dye together with a red reactive dye and/or a blue reactive dye, the development of a reactive dye composition which shows negligible change in hue with the change of dyeing conditions including an inorganic salt concentration, a bath ratio, a pH of a dye bath, a dyeing temperature, a dyeing period and the like over a wide temperature range from 90 to 140° C., excellent dyeing reproducibility and excellent washing property of a non-fixed dye and without causing problems such as a color transfer of a non-fixed dye during a drying step and the like is desired. Further, the development of a reactive dye composition having excellent formulation compatibility brought about by harmonizing a dyeing property of each dye component and the development of a method of dyeing cellulose fibers or cellulose-containing fibers are strongly desired.
SUMMARY OF THE INVENTION
[0010] Under the above circumstances, the present inventors zealously researched in order to develop a yellow reactive dye having high dyeing property and excellent dyeing reproducibility in a dye bath having an acidic to neutral pH and a wide temperature range. As a result, they found a disazo compound having desired properties.
[0011] Further, they found a reasonable dyeing technique by which cellulose or cellulose-containing fibers can be dyed with good reproducibility and without inviting a trouble caused by a insufficient washing of a non-fixed dye and the like, by using the above disazo compound together with a specific red reactive dye and/or a specific blue reactive dye so that a dyeing property of each dye component can be harmonized.
[0012] Accordingly, the present invention relates to:
[0013] (1) a disazo compound which in a free acid form is represented by the following general formula (1):
[0014] wherein R 1 is hydrogen atom or methoxy group; R 2 is hydrogen atom, methyl group, methoxy group, acetylamino group or ureido group; R 3 is hydrogen atom or methoxy group; R 4 is hydrogen atom, methyl group, acetylamino group or ureido group; and m is 2 or 3;
[0015] (2) a method of dyeing cellulosic fibers comprising using the disazo compound as described in the above (1);
[0016] (3) a reactive dye composition comprising
[0017] (A) a yellow reactive dye which comprises at least one compound selected from the group consisting of compounds which in free acid forms are represented by the general formula (1) as described in the above (1), together with
[0018] (B) a red reactive dye which comprises at least one compound selected from the group consisting of azo compounds which in free acid forms are represented by the following general formula (2):
[0019] wherein R 5 is CH 3 or C 2 H 5 ; R 6 and R 7 are independently H, C 1 or
[0020] and azo compounds which in free acid forms are represented by the following general formula (3):
[0021] wherein A is a benzene nucleus having 1 to 2 sulfonic acid group or carboxyl group and optionally methyl group, methoxy group or chlorine atom, or a naphthalene nucleus having 1 to 3 sulfonic acid groups; R 8 , R 9 and R 10 are independently hydrogen atom or methyl group; n is 1 or 2; Y is
[0022] or chlorine atom; and B is —(CH 2 ) p — in which p is 2 or 3, —C 2 H 4 OC 2 H 4 —, —CH 2 CH(OH)CH 2 —,
[0023] in which R 11 , R 12 and R 13 are independently hydrogen atom, methyl group, sulfonic acid group or carboxyl group, provided that this formula does not represent
[0024] in which Q is O, SO 2 , NHCO or NH,
[0025] and/or
[0026] (C) a blue reactive dye which comprises at least one compound selected from the group consisting of formazane compounds which in free acid forms are represented by the following general formula (4):
[0027] wherein D is a group of a formazane compound represented by the following general formula (5):
[0028] in which the benzene nucleus c may have sulfonic acid group or chlorine atom; t is 0 or 1; when t is 0, R 16 is hydrogen atom, E is the above-defined D or phenyl group substituted with methyl, methoxy, sulfonic acid group or chlorine and when t is 1, R 14 and R 15 each is hydrogen atom or methyl group; G is —C 2 H 4 —, —C 2 H 4 OC 2 H 4 —, phenylene group optionally substituted with methyl, sulfonic acid group, carboxyl or chlorine,
[0029] in which J is O, SO 2 , NH and NHCO,
[0030] Z is chlorine atom or
[0031] in which carboxyl group is bonded to 3 or 4 position;
[0032] E is the above-defined D; C 1-2 alkyl group; or phenyl group optionally substituted with methoxy, sulfonic acid group or carboxyl,
[0033] R 16 is hydrogen atom and alternatively R 16 together with E form
[0034] provided that when E is D, R 16 is hydrogen atom and when G is
[0035] E is not D,
[0036] and disazo compounds which in free acid forms are represented by the following general formula (6):
[0037] wherein M is phenyl group optionally substituted with sulfonic acid group, carboxyl, methyl, methoxy or chlorine, naphthyl group substituted with 1 to 3 sulfonic acid group, C 1-3 alkyl group optionally substituted with carboxyl or sulfonic acid group or hydrogen atom; R 17 is hydrogen atom or methyl group; W 1 and W 2 are independently chlorine atom or
[0038] in which carboxyl group is bonded to 3 or 4 position, provided that at least one of W 1 and W 2 is
[0039] in which carboxyl group is bonded to 3 or 4 position;
[0040] (4) a reactive dye composition as described in the above (3) which contains the red reactive dye (B) comprising a compound represented by the following formulae (7) and/or (8):
[0041] and a mixture of the blue reactive dye (C) comprising compounds represented by the following formulae (9) and (10):
[0042] (5) a reactive dye composition as described in the above (4) wherein the yellow reactive dye (A) comprises a compound represented by the formula (11):
[0043] and the mixing ratio of the compounds represented by the above formulae (9) and (10) in the blue reactive dye (C) is 50 to 70:50 to 30;
[0044] (6) a method of dyeing cellulose or cellulose-containing fibers comprising using the reactive dye composition described in the above (3), (4) or (5);
[0045] (7) a method of dyeing cellulose or cellulose-containing fibers comprising using the yellow reactive dye (A) together with the red reactive dye (B) and/or the blue reactive dye (C) as described in the above (3), (4) or (5);
[0046] (8) a method of dyeing cellulose or cellulose-containing fibers as described in the above (6) or (7) wherein a pH of a dye bath is 5 to 9 and a dyeing temperature is 90 to 140° C.; and
[0047] (9) a method of dyeing cellulose or cellulose-containing fibers as described in the above claim (8) wherein the dyeing temperature is 95 to 110° C.
DETAILED DESCRIPTION OF THE INVENTION
[0048] The present invention will be described in more detail.
[0049] The disazo compound of the present invention is represented by the above formula (1) in a free acid form. For example, this compound is synthesized by the following method.
[0050] A compound which in a free acid form is represented by the general formula (12):
[0051] wherein m is as defined above, is diazotized. The thus-diazotized compound is coupled with a compound represented by the general formula (13):
[0052] wherein R 1 and R 2 are as defined above,
[0053] to obtain a compound which in a free acid form is represented by the general formula (14):
[0054] wherein R 1 , R 2 and m are as defined above. The diazotization is conducted according to a conventional method using hydrochloric acid and sodium nitrite at a temperature of 0 to 20° C. The coupling is conducted at a temperature of 0 to 30° C. and a pH of 3 to 8. After the reaction, the reaction product is generally salted out with sodium chloride or the like, filtered and isolated.
[0055] On the other hand, a compound which in a free acid form is represented by the general formula (15):
[0056] is diazotized. The thus-diazotized compound is coupled with a compound represented by the general formula (16):
[0057] wherein R 3 and R 4 are as defined above, to obtain a compound which in a free acid form is represented by the general formula (17):
[0058] wherein R 3 and R 4 are as defined above. The diazotization is conducted according to a conventional method using hydrochloric acid and sodium nitrite at a temperature of 0 to 20° C. The coupling is conducted at a temperature of 0 to 30° C. and a pH of 3 to 8.
[0059] Then, the compound of the formula (14) or (17) and cyanuric chloride are condensed in any order to obtain a compound which in a free acid form is represented by the general formula (18):
[0060] wherein R 1 , R 2 , R 3 , R 4 and m are as defined above. The first condensation in the above reaction is conducted in water at a temperature of 0 to 30° C. and a pH of 2 to 8 and the second condensation is conducted at a temperature of 30 to 70° C. and a pH of 3 to 8. Then, the resultant compound of the above formula (18) is reacted with nicotinic acid to obtain a disazo compound represented by the above formula (1). This reaction is conducted in water at a temperature of 80 to 100° C. and a pH of 4 to 7.
[0061] The form of the disazo compound of the above formula (1) of the present invention may be either its free acid or its salt, or a mixture thereof. Preferably, the disazo compound of the above formula (1) is in the form of its alkali metal salt or its alkaline earth metal salt, especially in the form of Na, K and Li salts thereof. The disazo compound is generally isolated in the form of the above salt by subjecting it to a treatment such as salting out or the like, if necessary.
[0062] Example of the compound which in a free acid form is represented by the above formula (12) and which is used in the preparation of the disazo compound of the above formula (1) includes 2-amino-3,6-naphthalene-disulfonic acid, 2-amino-4,9-naphthalene-disulfonic acid, 2-amino-5,7-naphthalene-disulfonic acid, 2-amino-6,8-naphthalene-disulfonic acid and the like (wherein m is 2), and 2-amino-3,6,8-naphthalene-trisulfonic acid, 2-amino-4,6,8-naphthalene-trisulfonic acid and the like (wherein m is 3).
[0063] Example of the compound of the above formula (13) includes aniline, 2-methoxyaniline, 3-methylaniline, 3-methoxyaniline, 3-acetylaminoaniline, 3-ureidoaniline, 2,5-dimethoxyaniline, 2-methoxy-5-methylaniline, 2-methoxy-5-acetylaminoaniline and the like.
[0064] On the other hand, example of the compound which in a free acid form is represented by the above formula (15) includes 2-aminobenzenesulfonic acid, 3-aminobenzenesulfonic acid, 4-aminobenzenesulfonic acid and the like.
[0065] Example of the compound of the formula (16) includes aniline, 2-methoxyaniline, 3-methylaniline, 3-acetylaminoaniline, 3-ureidoaniline, 2-methoxy-5-methylaniline, 2-methoxy-5-acetylaminoaniline and the like.
[0066] Next, the reactive dye composition of the present invention will be described below.
[0067] The reactive dye composition of the present invention can be obtained by formulating (A) a yellow reactive dye with (B) a red reactive dye and/or (C) a blue reactive dye.
[0068] The reactive dye composition of the present invention comprises as a yellow reactive dye at least one compound selected from the group consisting of compounds represented by the above general formula (1).
[0069] Example of the compound represented by the above general formula (1) is shown in Table 1.
TABLE 1 positions of SO 3 H position of group on SO 3 H group naphthalene on benzene ring R 1 R 2 ring R 3 R 4 4, 8 H NHCOCH 3 3 OCH 3 H 4, 8 H NHCONH 2 4 H H 6, 8 H NHCOCH 3 4 H H 3, 6, 8 H OCH 3 3 OCH 3 H 3, 6, 8 H NHCONH 2 4 H H 4, 6, 8 H NHCOCH 3 4 H H 4, 6, 8 H CH 3 3 H CH 3
[0070] Among the disazo compounds represented by the general formula (1) contained as a yellow reactive dye in the reactive dye composition of the present invention, a compound represented by the formula (11) is preferable. Any other yellow reactive dye having similar reactive groups such as C.I. Reactive Yellow 162, 163, 178 and the like may be used as a yellow reactive dye, in addition to the disazo compound represented by the above formula (1).
[0071] The form of the disazo compound of the above formula (1) may be either its free acid or its salt, or a mixture thereof. Preferably, the disazo compound of the formula (1) is in the form of its alkali metal salt or its alkaline earth metal salt, especially in the form of Na, K and Li salts thereof. The disazo compound is generally isolated in the form of the above salt by subjecting it to a treatment such as salting out or the like, if necessary.
[0072] A red reactive dye capable of being contained in the reactive dye composition of the present invention comprises at least one compound selected from the group consisting of compounds represented by the general formula (2) and compounds represented by the general formula (3). Compounds represented by the general formulae (7) and/or (8) are preferable. Further, a red reactive dye may comprise a mixture of a compound represented by the general formula (2) and a compound represented by the general formula (3). Among the compounds represented by the general formula (2), a compound which in a free acid form is represented by the following formula (19) is preferable.
[0073] A mixing ratio of a compound represented by the general formula (3) and a compound represented by the formula (19) is generally 50 to 100:50 to 0, preferably 70 to 100:30 to 0. Similar to the case of yellow reactive dye, any other red reactive dye having similar reactive groups may be used as a red reactive dye, in addition to the compounds represented by the general formulae (2) and (3).
[0074] A blue reactive dye capable of being contained in the reactive dye composition of the present invention comprises at least one compound selected from the group consisting of compounds represented by the general formula (4) and compounds represented by the general formula (6). A mixture of a compound represented by the above formula (9) and a compound represented by the above formula (10) is preferable. The mixture comprising a compound represented by the formula (9) and a compound represented by the formula (10) in a mixing ratio of 50 to 70:50 to 30 is more preferable. Similar to the cases of yellow reactive dye and red reactive dye, any other blue reactive dye having similar reactive groups may be used as a blue reactive dye, in addition to the compounds represented by the general formulae (4) and (6).
[0075] The above compounds of the above formulae (2), (3), (4) and (6) can be synthesized by known methods, for example the methods described in JP-A-60-086169(1985), JP-A-60-090264 (1985), JP-A-60-090265 (1985) and the like. The form of each of these compounds may be either its free acid or its salt, or a mixture thereof. Preferably, the above compounds are in the form of their alkali metal salts or their alkaline earth metal salts, especially in the form of Na, K and Li salts thereof. These compounds are generally isolated in the form of their salts by subjecting them to a treatment such as salting out or the like, if necessary.
[0076] In the reactive dye composition of the present invention, dyes may be formulated by any method of formulation. For example, a method comprising independently preparing respective dye and then blending the dyes; a method comprising blending dyes in the form of reaction liquids immediately after their preparation and drying to make a composition; a method comprising dissolving respective dye upon dyeing to make a composition under solution; a method comprising dissolving respective dye in a dye bath to make a composition in the dye bath can be employed. A mixing ratio of a yellow reactive dye (A) with a red reactive dye (B) and/or a blue reactive dye (C) is not particularly limited. Generally it is selected depending on desired color tone. For example, a mixing ratio of a yellow reactive dye (A), a red reactive dye (B) and a blue reactive dye (C) to obtain a brown color tone, a gray color tone and a dark green color tone easily giving rise to problems as to a dyeing reproducibility and the like is preferably selected as follows:
[0077] (brown color tone)
[0078] (A):(B):(C)=40 to 80:10 to 40:5 to 40
[0079] (gray color tone)
[0080] (A):(B):(C)=10 to 40:10 to 20:50 to 80
[0081] (dark green color tone)
[0082] (A):(B):(C)=30 to 60:0 to 10:40 to 70
[0083] If necessary, the reactive dye composition of the present invention contains known additives such as a concentration controlling agent (anhydrous sodium sulfate and the like), a dispersing agent (Demol N, trade name of Kao Corporation, a Tamol-type dispersing agent; Vanilex RN, trade name of Kao Corporation, a lignin-type dispersing agent, and the like), an anti-reducing agent (Polymin L New, trade name of Nippon Kayaku Co., Ltd., an anti-reduction agent; MS powder, trade name of Meisei Chemical Works, Ltd., an anti-reduction agent, and the like).
[0084] The disazo compound of the above formula (1) and the reactive dye composition according to the present invention can be applied for dyeing cellulosic fibers by a method such as a dip dyeing method, a continuous dyeing method by padding according to the conventional method and a printing method. If the dying method of the present invention is a dip dyeing method, a bath ratio is generally 1:5 to 1:50. In the dyeing method of the present invention, the dyeing method per se can be conducted according to a known method.
[0085] A fiber material capable of being dyed by the dyeing method of the present invention includes cotton, hemp, rayon, polynosic, cupra, lyocell fibers and the like, their mutual mixtures, their blended fibers with other fibers such as polyester fibers, acetate fibers, polyacrylonitrile fibers, wool, silk, polyamide fibers such as nylon and the like, and cowoven fabrics thereof.
[0086] The disazo compound and the reactive dye composition according to the present invention are very useful since they have always high dyeing property under the condition of a bath pH of 5 to 9 and a temperature of generally 90 to 140° C., more preferably 95 to 135° C. and therefore they can dye blended fibers containing cellulosic fibers, especially blended polyester/cotton fibers in the co-existence of a disperse dye by a reasonable one bath/one step dyeing method.
[0087] For example, the dyeing of blended polyester/cotton fibers in a one bath/one step dyeing method is conducted as follows:
[0088] The disazo compound or the reactive dye composition of the present invention and a disperse dye(s) are formulated depending on desired hue and concentration. Additionally, a pH controlling agent for keeping a dye bath at a pH of 5 to 9, preferably 6 to 8 [for example, 0.1 to 5 g/L of Kayaku Buffer P-7 (trade name of Nippon Kayaku Co., Ltd.)], an inorganic salt [for example, 5 to 80 g/L of anhydrous sodium sulfate] and if necessary, a dispersing and leveling agent [for example, 0.1 to 5 g/L of KP leveller RP (trade name of Nippon Kayaku Co., Ltd.)] are added to prepare a dye bath with a bath ratio of 1:5 to 1:50. After a fabric to be dyed is introduced in the dye bath, for example, the temperature of the dye bath is increased to 120 to 140° C. over 20 to 40 minutes and the dyeing is conducted at the same temperature for 20 to 60 minutes. After the dyeing step is finished, the resultant dyed fabric is washed with water and/or hot water and then soaped in a soaping bath containing 0.1 to 5 g/L of a commercially available soaping agent to complete the dyeing.
[0089] Further, the disazo compound and the reactive dye composition according to the present invention have excellent property that they show high dyeing property at a relatively low temperature around 100° C. Therefore, the disazo compound and the reactive dye composition of the present invention can dye polyacrylonitrile fibers which are generally dyed with a basic dye at about 100° C. in a dye bath having an acidic to neutral pH, or wool, silk and blended fabrics comprising cellulose fibers and polyamide fibers (for example, nylon and the like) which are dyed with an acid dye. The blended fibers can be dyed in one bath dyeing method using the above compound or composition.
[0090] For example, the one bath dyeing of blended nylon/cotton fibers is conducted as follows:
[0091] The disazo compound or the reactive dye composition of the present invention and an acid dye(s) are formulated depending on desired hue and concentration. Additionally, a pH controlling agent for keeping a dye bath at a pH of 5 to 9, preferably 6 to 8 [for example, 0.1 to 5 g/L of Kayaku Buffer P-7 (trade name of Nippon Kayaku Co., Ltd.)], an inorganic salt [for example, 5 to 40 g/L of anhydrous sodium sulfate] and if necessary, an anti-contamination agent for nylon [for example, 0.1 to 5 g/L of Sunresist NR-100L (trade name of Nikka Chemical Co., Ltd.)] are added to prepare a dye bath with a bath ratio of 1:5 to 1:50. After a fabric to be dyed is introduced in the dye bath, for example, a temperature of the dye bath is increased to 90 to 110° C., preferably 95 to 110° C. over 20 to 60 minutes and the dyeing is conducted at the same temperature for 20 to 60 minutes. If necessary, 0 to 40 g/L of anhydrous sodium sulfate is further added during a dyeing step. After the dyeing step is finished, the resultant dyed fabric is washed with water and/or hot water and then soaped in a soaping bath containing 0.1 to 5 g/L of a commercially available soaping agent to complete the dyeing.
[0092] A fiber material capable of being dyed with the disazo compound or the reactive dye composition of the present invention is not limited to the materials mentioned above. A fiber material essentially consisting of cellulosic fibers can be dyed in the same way as that described above.
[0093] Upon dyeing, the conventional method comprising treating a fiber material in a dye bath at a temperature of generally 40 to 100° C., adding an acid binder in the dye bath and then dyeing can be employed. Alternatively, the so-called all-in-one dyeing method comprising previously adding to a dye bath an acid binder or a buffer in an amount for keeping the dye bath at a pH of 5 to 9 and then dyeing can be employed.
[0094] For example, when cellulosic fibers such as cotton and the like are dyed, a dye bath is first prepared by mixing the disazo compound or the reactive dye composition of the present invention in an amount which is varied depending on desired hue and concentration, a pH controlling agent for keeping the dye bath at a pH of 5 to 9, preferably 6 to 8 [for example, 0.1 to 5 g/l of Kayaku Buffer P-7 (trade name of Nippon Kayaku Co., Ltd., a pH controlling agent)] and an inorganic acid, [for example, 5 to 100 g/L of anhydrous sodium sulfate] in a bath ratio of 1:5 to 1:50. After a material to be dyed is introduced in the dye bath, for example a temperature of the dye bath is increased to generally 90 to 120° C., suitably 95 to 110° C. over 20 to 40 minutes and the dyeing is conducted at the same temperature for 20 to 60 minutes. As the pH controlling agent used in the dyeing of cellulosic fibers, a pH sliding agent by which a pH is varied with time due to the change in temperature and the like during a dyeing step, for example 0.1 to 5 g/L of Kayaslide PH-509 or Kayaslide PH-608 (Kayaslide is a trade name of Nippon Kayaku Co., Ltd., a pH controlling or sliding agent), can be used. After the dyeing step is finished, the resultant dyed material is washed with water and/or hot water and then soaped in a soaping bath containing 0.1 to 5 g/L of a commercially available soaping agent to complete the dyeing.
[0095] The disazo compound and the reactive dye composition of the present invention has high dyeing property even at a low temperature range around 100° C., shows a small change in hue even if dyeing conditions are varied, dyes with excellent dyeing reproducibility and washes off a non-fixed dye satisfactorily. Accordingly, they can dye a fiber material without inviting the problem of a color transfer of a non-fixed dye to the fabric material during a drying step. Further, the disazo compound and the reactive dye composition of the present invention are very excellent in solid dyeing of blended fibers comprising a mutual mixture of cellulosic fibers, for example blended cotton/rayon fibers.
[0096] By using the disazo compound and the reactive dye composition of the present invention, problems caused by a delicate and complicated addition of an acid binder during a dyeing step such as a lowering in color yield due to hydrolysis, an unlevel dyeing, a color breakup upon dyeing using a mixed dye and the like can be resolved. Simultaneously, the dyeing can be conducted with improved efficiency and high reproducibility.
[0097] Upon dyeing, the disazo compound of the present invention can be used singly or in mixture. If desired, the disazo compound of the present invention can be used in combination with a reactive dye other than the disazo compound of the present invention, a disperse dye and/or an acid dye.
[0098] An acid binder and a pH controlling agent (sometimes referred to as “a buffer”) usable in the dyeing method of the present invention are not especially limited. Example of an acid binder includes sodium carbonate, potassium carbonate, sodium hydroxide, potassium hydroxide, sodium metasilicate, trisodium phosphate, tripotassium phosphate, sodium pyrophosphate, potassium pyrophosphate, sodium trichloroacetate and the like. Example of a pH controlling agent includes commercially available pH controlling agents, acetic acid+sodium acetate, monosodium phosphate+disodium phosphate, monopotassium phosphate+disodium phosphate, maleicacid+borax, boric acid+borax, and the like. They can be used singly or in a suitable mixture, if necessary.
[0099] If necessary during a dyeing step, known dyeing auxiliaries such as a dispersing agent (Demol N, Vanilex RN and KP Leveller RP, trade names of Nippon Kayaku Co., Ltd., a dispersing and leveling agent for disperse dyes), a leveling agent (Newbon TS, trade name of Nikka Chemical Co., Ltd., a leveling agent for specific anionic nylon; Miguregal AM, trade name of Nikka Chemical Co., Ltd., a leveling agent for disperse dyes), a carrier agent (Carrier 430, trade name of Nikka Chemical Co., Ltd., a carrier agent, and the like), a metal sequestrant (Kayachelator N-1, trade name of Nippon Kayaku Co., Ltd., a neutral metal sequestrant, and the like), an anti-reduction agent (Polymin L-New, Miss. powder and the like) and the like can be used.
[0100] The disazo compound represented by the above formula (1) and the reactive dye composition of the present invention have always high dyeing property as a reactive dye over a wide temperature range in the presence of a buffering agent capable of keeping a dye bath at a pH of 5 to 9. Therefore, they can dye cellulosic fibers with high color yield and excellent properties including build-up property, levelness and reproducibility. Owing to these properties, the disazo compound and the reactive dye composition of the present invention are very effective for dyeing blended fibers containing cellulosic fibers, especially blended polyester/cotton fibers in the co-existence of a disperse dye by a reasonable one bath/one step dyeing method. Of course, a material to be dyed is not limited to the above-mentioned materials. The disazo compound and the reactive dye composition of the present invention can also dye cellulosic fibers such as cotton, hemp, rayon, polynosic, cupra, lyocell fibers or the like and their mixture with excellent fastnesses in various aspects such as a fastness to light, a fastness to chlorinated water, a fastness to washing and the like and without inviting any problem such as thermal discoloration, phototrophy and the like.
EXAMPLES
[0101] The present invention will be described in further detail by referring to the following examples. All parts and percentages referred to herein are by weight unless otherwise indicated.
Example 1
[0102] 2-Amino-4,8-naphthalene-disulfonic acid was diazotized and coupled with 3-acetylaminoaniline. Then, the thus-coupled product was salted out with sodium chloride and filtered to separate 23.2 parts of 2-(4-amino-2-acetylaminophenylazo)-4,8-naphthalene disulfonic acid. Sodium hydroxide was added thereto and dissolved in 300 parts of water. After 9.3 parts of cyanuric chloride was added, a first condensation was conducted at a temperature of 0 to 5° C. and a pH of 5 to 7. Sodium carbonate was added during the reaction to complete the reaction. Then, a solution of 13.8 parts of 4-(4-aminophenylazo) benzenesulfonic acid in 200 parts of water was added and a second condensation was conducted at a temperature of 50° C. and a pH of 6 to 7. Next, a suspension of 12 parts of nicotinic acid in 100 parts of water was added and then the reaction was continued at a temperature of 95° C. and a pH of 6 to 7 until completion. Thereafter, the reaction was salted out, thereby 41 parts of the disazo compound which in a free acid form is represented by the formula (20) is obtained.
[0103] This compound was dissolved in water very well. The resultant solution had a maximum absorption wavelength of, 365 nm.
[0104] The compound 4-(4-aminophenylazo)benzenesulfonic acid used in this example was obtained by coupling aniline previously sulfomethylated with formalin and sodium hydrogensulfite with diazotized 4-aminobenezenesulfonic acid, hydrolyzing the sulfomethyl group under an alkaline condition, salting out and separating.
Example 2
[0105] 2-Amino-3,6,8-naphthalene-trisulfonic acid was diazotized and coupled with 3-acetylaminoaniline. Then, the thus-coupled product was salted out with sodium chloride and filtered to separate 27.2 parts of 2-(4-amino-2-acetylaminophenylazo)-3,6,8-naphthalene trisulfonic acid. Sodium hydroxide was added thereto and dissolved in 300 parts of water. After 9.3 parts of cyanuric chloride was added, a first condensation was conducted at a temperature of 0 to 5° C. and a pH of 5 to 7. Sodium carbonate was added during the reaction to complete the reaction. Then, a solution of 13.8 parts of 4-(4-aminophenylazo)-benzenesulfonic acid in 200 parts of water was added and a second condensation was conducted at a temperature of 50° C. and a pH of 6 to 7. Next, a suspension of 12 parts of nicotinic acid in 100 parts of water was added and then there action was continued at a temperature of 95° C. and a pH of 6 to 7 until completion. Thereafter, the reaction was salted out, thereby 44 parts of the disazo compound which in a free acid form is represented by the formula (21) is obtained.
[0106] This compound was dissolved in water very well. The resultant solution had a maximum absorption wavelength of 377 nm.
Examples 3 to 18
[0107] Disazo compounds which in free acid forms are represented by the following general formula (22) and having substituents as shown in Table 2 were synthesized in the same way as described in Example 1. Table 2 also shows a maximum absorption wavelength (nm) of a solution of each of the resultant compounds.
TABLE 2 maximum positions position absorp- of SO 3 H of SO 3 H tion group on group on wave- naphtha- benzene length Ex. lene ring R 1 R 2 ring R 3 R 4 (nm) 3 4, 8 H H 4 H H 355 4 4, 8 H NHCOCH 3 3 OCH 3 H 366 5 4, 8 H OCH 3 3 OCH 3 H 368 6 4, 8 H NHCONH 2 4 H H 373 7 4, 8 H NHCONH 2 4 H NHCONH 2 375 8 4, 8 OCH 3 CH 3 4 H NHCOCH 3 378 9 6, 8 H NHCOCH 3 4 H H 369 10 6, 8 H NHCOCH 3 3 H CH 3 370 11 6, 8 H NHCONH 2 4 H NHCONH 2 376 12 6, 8 OCH 3 H 3 OCH 3 H 366 13 6, 8 H CH 3 3 H CH 3 368 14 3, 6 H NHCOCH 3 4 H H 367 15 3, 6 H NHCONH 2 3 H CH 3 374 16 3, 6 H CH 3 4 H CH 3 366 17 5, 7 H NHCOCH 3 4 H H 362 18 5, 7 H NHCONH 2 4 H NHCOCH 3 370
Examples 19 to 29
[0108] Disazo compounds which in free acid forms are represented by the following general formula (23) and having substituents as shown in Table 3 were synthesized in the same way as described in Example 2. Table 3 also shows a maximum absorption wavelength (nm) of a solution of each of the resultant compounds.
TABLE 3 maximum positions position absorp- of SO 3 H of SO 3 H tion group on group on wave- naphtha- benzene length Ex. lene ring R 1 R 2 ring R 3 R 4 (nm) 19 3, 6, 8 H H 4 H H 371 20 3, 6, 8 H NHCOCH 3 3 OCH 3 H 379 21 3, 6, 8 H OCH 3 3 OCH 3 H 381 22 3, 6, 8 H NHCONH 2 4 H H 384 23 3, 6, 8 H NHCONH 2 4 H NHCONH 2 385 24 3, 6, 8 OCH 3 CH 3 4 H NHCOCH 3 390 25 4, 6, 8 H NHCOCH 3 4 H H 371 26 4, 6, 8 H NHCOCH 3 3 H CH 3 372 27 4, 6, 8 H NHCONH 2 4 H NHCONH 2 379 28 4, 6, 8 H CH 3 3 H CH 3 369 29 4, 6, 8 OCH 3 H 4 H NHCOCH 3 368
Example 30
[0109] A dye bath was prepared by adding water to 0.5 part of the disazo compound obtained in Example 2, 60 parts of mirabilite, 2 parts of disodium phosphate, 0.5 part of monopotassium phosphate and 1 part of sodium m-nitrobenzene sulfonic acid group such that the total volume was 1000 parts. The pH value of this dye bath was 7. 50 Parts of a knitted cotton fabric was introduced in the dye bath. After the temperature of the dye bath was increased to 130° C. over 30 minutes, the dyeing was conducted at this temperature for 40 minutes. The pH value of the dye bath after dyeing was 7, the same as that before dyeing. Then, the fabric was washed with water, soaped in an aqueous solution containing an anionic surfactant at a temperature of 100° C., washed with water and dried, there by a yellow-dyed fabric was obtained.
[0110] The thus-dyed fabric was levelly dyed at a high color yield. It did show neither thermal discoloration nor phototropy. Its fastnesses to light, chlorinated water and washing were good.
Example 31
[0111] A dye bath was prepared by adding water to 0.3 part of the disazo compound obtained in Example 1, 0.15 part of Kayacelon Yellow E-3GL (a disperse dye of Nippon Kayaku Co., Ltd.), 0.05 part of Kayacelon Yellow E-BRL conc (a disperse dye of Nippon Kayaku Co., Ltd.), 60 parts of mirabilite, 1 part of sodium m-nitrobenzenesulfonate, 2 parts of a condensate of naphthalenesulfonic acid with formalin (a dispersing agent), 2 parts of disodium phosphate and 0.5 part of monopotassium phosphate such that the total volume was 1000 parts. The pH value of this dye bath was 7. 50 Parts of a fabric comprising blended polyester/cotton ({fraction (50/50)}) fibers was introduced in the dye bath. After the temperature of the dye bath was increased to 130° C. over 30 minutes, the dyeing was conducted at this temperature for 60 minutes. Then, the fabric was washed with water, soaped in an aqueous solution containing an anionic surfactant at a temperature of 100° C., washed with water and dried, thereby a yellow-dyed fabric was obtained.
[0112] The thus-dyed fabric was levelly dyed irrespective of the nature of the fibers at a high color yield. Its fastnesses to light, chlorinated water and washing were good.
Example 32
[0113] A dye bath was prepared by adding water to 0.3 part of the disazo compound obtained in Example 1, 0.15 part of Kayacelon Yellow E-3GL, 0.05 part of Kayacelon Yellow E-BRL conc, 60 parts of mirabilite, 2 parts of a condensate of naphthalenesulfonic acid with formalin (a dispersing agent), 3 parts of Mignol RP100 (a special emulsifying agent of Ipposha Oil Industries Co., Ltd.), 2 parts of disodium phosphate and 0.5 part of monopotassium phosphate such that the total volume was 1000 parts. The pH value of this dye bath was 7. 50 Parts of a fabric comprising blended polyester/cotton ({fraction (50/50)}) fibers was introduced in the dye bath. After the temperature of the dye bath was increased to 130° C. over 30 minutes, the dyeing was conducted at this temperature for 60 minutes. Then, the fabric was washed with water, soaped in an aqueous solution containing an anionic surfactant at a temperature of 100° C., washed with water and dried, thereby a yellow-dyed fabric was obtained.
[0114] The thus-dyed fabric was levelly dyed irrespective of the nature of the fabrics at a high color yield similar to the dyed fabric of Example 31. Its various fastnesses were good.
Example 33
[0115] A dye bath was prepared by adding water to 0.5 part of the disazo compound obtained in Example 2, 60 parts of mirabilite, 2 parts of disodium phosphate and 0.5 part of monopotassium phosphate such that the total volume was 1000 parts. The pH value of this dye bath was 7. 50 Parts of a knitted cotton fabric was introduced in the dye bath. After the temperature of the dye bath was increased to 95° C. over 30 minutes, the dyeing was conducted at this temperature for 60 minutes. The pH value of the dye bath after dyeing was 7, the same as that before dyeing. Then, the fabric was washed with water, soaped in an aqueous solution containing an anionic surfactant at a temperature of 100° C., washed with water and dried, thereby a yellow-dyed fabric was obtained.
[0116] The thus-dyed fabric was levelly dyed at a high color yield similar to the dyed fabric of Example 30. Its various fastnesses were good.
Example 34
[0117] A dye bath was prepared by adding water to 0.5 part of the disazo compound obtained in Example 2, 0.5 part of Kayacelon React Blue CN-MG (reactive dye of Nippon Kayaku Co., Ltd.), 60 parts of mirabilite, 2 parts of disodium phosphate and 0.5 part of monopotassium phosphate such that the total volume was 1000 parts. The pH value of this dye bath was 7. 50 Parts of a knitted cotton fabric was introduced in the dye bath. After the temperature of the dye bath was increased to 95° C. over 30 minutes, the dyeing was conducted at this temperature for 60 minutes. The pH value of the dye bath after dyeing was 7, the same as that before dyeing. Then, the fabric was washed with water, soaped in an aqueous solution containing an anionic surfactant at a temperature of 100° C., washed with water and dried, thereby a green-dyed fabric was obtained.
[0118] During the dyeing step, the dyes mixed were compatible each other. A hue of the fabric to be dyed remained similarly and the resultant dyed fabric was levelly dyed without inviting any problem such as color breakup and unlevel dyeing. Dyeing reproducibility was excellent.
Example 35
[0119] A dye bath was prepared by adding water to 0.3 part of the disazo compound obtained in Example 1, 0.2 part of Kayanol Milling Yellow 5GW (an acid dye of Nippon Kayaku Co., Ltd.), 0.04 part of Kayanol Milling Yellow RW new (an acid dye of Nippon Kayaku Co., Ltd.), 30 parts of mirabilite, 2 parts of disodium phosphate and 0.5 part of monopotassium phosphate such that the total volume was 1000 parts. The pH value of this dye bath was 7. 50 Parts of a cowoven fabric comprising blended nylon/cotton ({fraction (50/50)}) fibers was introduced in the dye bath. After the temperature of the dye bath was increased to 100° C. over 30 minutes, the dyeing was conducted at this temperature for 60 minutes. Then, the fabric was washed with water, soaped in an aqueous solution containing an anionic surfactant at a temperature of 100° C., washed with water and dried, thereby a yellow-dyed fabric was obtained.
[0120] The thus-dyed fabric was levelly dyed irrespective of the nature of the fibers at a high color yield.
Example 36
[0121] A dye bath was prepared by adding water to the combination and amounts of dyes (compounds) shown in Table 4 (Combination and amounts (in parts) of compounds), 50 parts of anhydrous sodium sulfate and 1 part of Kayaku Buffer P-7 (a pH controlling agent) such that the total volume was 1000 parts. The pH value of this dye bath was 7.2. 50 Parts of a knitted cotton fabric was introduced in the dye bath. After the temperature of the dye bath was increased to 100° C. over 40 minutes, the dyeing was conducted at this temperature for 30 minutes. The pH value of the dye bath remaining after dyeing was 7.0. Then, the fabric was washed with water and hot water successively, soaped in 1000 parts of an aqueous solution containing 1 part of a commercially available soaping agent at a temperature of 100° C. for 10 minutes, washed with water and dried, thereby a brown-dyed fabric was obtained.
[0122] In each of Comparative Examples 1 to 3, the dyeing was conducted in the same way as that described in Example 36, provided that the combination and amounts of dyes (compounds) shown in Table 4, was used, thereby a brown-dyed fabric was obtained.
TABLE 4 reactive dyes yellow red blue formula amount formula amount formula amount Ex. 36 (11) 0.20 (7) 0.10 (9) 0.12 (10) 0.08 Comparative (24) 0.20 (7) 0.10 (9) 0.12 Ex. 1 (10) 0.08 Comparative (25) 0.05 (7) 0.10 (9) 0.12 Ex. 2 (26) 0.15 (10) 0.08 Comparative (26) 0.15 (7) 0.10 (9) 0.12 Ex. 3 (24) 0.05 (10) 0.08
[0123] The compounds which in free acid forms are represented by the formulae (24), (25) and (26), respectively used in Comparative Examples 1 to 3 are shown below.
[0124] Next, methods for testing and judging dependency on dyeing conditions, fixing efficiency and washing property will be described below.
[0125] Dependency on Dyeing Conditions
[0126] [Salt Concentration]
[0127] The dyeing was conducted in the same way as that described in Example 36 except that 25 parts of anhydrous sodium sulfate was used instead of 50 parts of anhydrous sodium sulfate.
[0128] Method of judgment: The difference in hue between the fabric dyed with 50 parts of anhydrous sodium sulfate and the fabric dyed with 25 parts of anhydrous sodium sulfate was judged by the naked eye.
[0129] ◯ small hue difference
[0130] Δ medium hue difference
[0131] X significant hue difference
[0132] [pH]
[0133] The dyeing was conducted in the same way as that described in Example 36 except that 1 part of a mixture of boric acid and borax (7:3) was used instead of 1 part of Kayaku Buffer P-7 (a pH controlling agent). The pH value of the dye bath was 8.3. The pH value of the dye bath remaining after dyeing was 8.0.
[0134] Method of judgment: The difference in hue between the fabric dyed in a dye bath of pH 7 and the fabric dyed in a dye bath of pH 8 was judged by the naked eye.
[0135] ◯ small hue difference
[0136] Δ medium hue difference
[0137] X significant hue difference
[0138] [Temperature]
[0139] The dyeing was conducted in the same way as that described in Example 36 except that the dyeing temperature of 95° C. was used instead of the dyeing temperature of 100° C.
[0140] Method of judgment: The difference in hue between the fabric dyed at the temperature of 100° C. and the fabric dyed at the temperature of 95° C. was judged by the naked eye.
[0141] ◯ small hue difference
[0142] Δ medium hue difference
[0143] X significant hue difference
[0144] Fixing Efficiency
[0145] The dyeing was started in the same way as that described in Example 36. After the dyeing was conducted at a temperature of 100° C. for 30 minutes, the thus-dyed fabric was taken out, immediately dehydrated and dried, thereby a non-washed fabric was obtained.
[0146] Method of judgment: The difference in hue between the above non-washed fabric and the dyed fabric after washing obtained in Example 36 was judged by the naked eye. The fixing efficiency means a ratio of (a fixed dye)/the total of (a fixed dye and a non-fixed dye) on a dyed fabric.
[0147] ◯ hue difference is small and lowering in concentration is minor; It indicates that fixing efficiency of each of yellow, red and blue reactive dyes is high.
[0148] X blue hue is strong and lowering in concentration is significant; It indicates that fixing efficiency of a yellow reactive dye is low. When a fixing efficiency of certain hue component is lower in a mixed dyeing, a reproducibility upon dyeing becomes poor.
[0149] Washing Property
[0150] The dyeing was started in the same way as that described in Example 36. After the dyeing was conducted at a temperature of 100° C. for 30 minutes, the thus-dyed fabric was taken out, washed with water, soaped in 1000 parts of an aqueous solution containing 1 part of a commercially available soaping agent at 95° C. for 10 minutes and then washed with water, thereby a dyed fabric was obtained. Immediately the dyed fabric under a wet condition was folded in four. A cotton broadcloth (white cloth) was put on an uppermost of the folded fabric and ironed at 130° C. for three minutes so that the fabric and the cloth were subjected to heat treatment under pressure.
[0151] Method of judgment: The degree of color transfer of a non-fixed dye to a cotton broadcloth (white cloth) by this heat treatment was judged by the naked eye.
[0152] ◯ Color transfer of an on-fixed dye to a white cloth is minor. The color similar to that of the dyed fabric is transferred.
[0153] X Color transfer of a non-fixed dye, especially a yellow dye is significant. When a washing property is poor and a color transfer of a non-fixed dye during a drying step of a dyed fabric is significant, levelness or fastnesses become worse.
[0154] Dependency on dyeing conditions, fixing efficiency and washing property of Example 36 and Comparative Examples 1 to 3 were compared. Results are shown in Table 5.
TABLE 5 dependency on dyeing condition salt fixing washing concentration pH temperature efficiency property Ex. 36 ◯ ◯ ◯ ◯ ◯ Comparative Δ X Δ X X Ex. 1 Comparative ◯ X X X X Ex. 2 Comparative ◯ X Δ X X Ex. 3
[0155] Only in the case of using the combination of compounds for dyeing as shown in Example 36, each dye component of yellow, red and blue reactive dyes showed the same dyeing property. Even if the dyeing conditions such as salt concentration, pH of a dye bath, dyeing temperature and the like were varied, a change in hue was minor, a fixing efficiency was high and a dyeing reproducibility was also excellent. Further, a color transfer of a non-fixed dye was not observed and a washing property was excellent. In addition, the dyeing rates of dye components agreed well with each other and therefore a very level dyeing was attained.
Examples 37 to 46
[0156] The dyeing was conducted in the same way as that described in Example 36 except that the combination and amounts of compounds as shown in Table 6 was used.
TABLE 6 reactive dyes yellow red blue formula amount formula amount formula amount Ex. 37 (27) 0.20 (7) 0.10 (9) 0.12 (10) 0.08 Ex. 38 (11) 0.16 (7) 0.10 (9) 0.12 (25) 0.04 (10) 0.08 Ex. 39 (11) 0.16 (7) 0.10 (9) 0.12 (26) 0.04 (10) 0.08 Ex. 40 (11) 0.20 (8) 0.10 (9) 0.12 (10) 0.08 Ex. 41 (11) 0.20 (7) 0.05 (9) 0.12 (8) 0.05 (10) 0.08 Ex. 42 (11) 0.20 (7) 0.07 (9) 0.12 (19) 0.03 (10) 0.08 Ex. 43 (11) 0.20 (7) 0.10 (9) 0.02 Ex. 44 (11) 0.02 (7) 0.02 (10) 2.00 Ex. 45 (11) 1.00 (7) 1.00 — — Ex. 46 (11) 0.50 — — (9) 0.30 (10) 0.20
[0157] The compound which in a free acid form is represented by the formula (27) used in Example 37 is shown below.
[0158] The hue of the resultant dyed fabric in Examples 37 to 46 was a dark pink color (Example 43), a navy blue color (Example 44), a scarlet red color (Example 45), a green color (Example 46) or a brown color (other examples).
[0159] In either of the combinations of Examples 37 to 46, the dyeing rates of dye components during a dyeing step agreed well with each other, a fixing efficiency was high and a washing property was excellent. Further, each of the resultant dyed fabrics was excellent in levelness and various fastnesses such as a fastness to light, a fastness to light with perspiration, a fastness to chlorinated water and the like.
Examples 47 to 50
[0160] A dye bath was prepared by adding water to the combination and amounts of dyes (compounds) shown in Table 7, 50 parts of anhydrous sodium sulfate and 1 part of Kayaslide PH-509 (a pH sliding agent of Nippon Kayaku Co., Ltd.) such that the total volume was 1000 parts. The pH value of this dye bath was 5.2. 50 Parts of a knitted cotton fabric was introduced in the dye bath. After the temperature of the dye bath was increased to 95° C. over 40 minutes, the dyeing was conducted at this temperature for 30 minutes. The pH value of the dye bath remaining after dyeing was 8.7. Then, the fabric was washed with water and hot water successively, soaped in 1000 parts of an aqueous solution containing 1 part of a commercially available soaping agent at a temperature of 100° C. for 10 minutes, washed with water and dried, thereby a dyed fabric was obtained.
Examples 51 to 54
[0161] A dye bath was prepared by adding water to the combination and amounts of dyes (compounds) shown in Table 7, 50 parts of anhydrous sodium sulfate and 1 part of Kayaku Buffer P-7 (a pH controlling agent of Nippon Kayaku Co., Ltd.) such that the total volume was 1000 parts. The pH value of this dye bath was 7.2. 50 Parts of a knitted cotton fabric was introduced in the dye bath. After the temperature of the dye bath was increased to 120° C. over 40 minutes, the dyeing was conducted at this temperature for 30 minutes. The pH value of the dye bath remaining after dyeing was 6.9. Then, the fabric was washed with water and hot water successively, soaped in 1000 parts of an aqueous solution containing 1 part of a commercially available soaping agent at a temperature of 100° C. for 10 minutes, washed with water and dried, thereby a dyed fabric was obtained.
TABLE 7 reactive dyes yellow red blue formula amount formula amount formula amount Ex. 47 (11) 0.18 (7) 0.12 (9) 0.11 (10) 0.08 Ex. 48 (11) 0.20 (8) 0.12 (9) 0.11 (10) 0.08 Ex. 49 (11) 1.10 (7) 0.90 — — Ex. 50 (11) 0.55 — — (9) 0.30 (10) 0.20 Ex. 51 (11) 0.18 (7) 0.12 (9) 0.11 (10) 0.08 Ex. 52 (11) 0.20 (8) 0.12 (9) 0.11 (10) 0.08 Ex. 53 (11) 1.10 (7) 0.90 — — Ex. 54 (11) 0.55 — — (9) 0.30 (10) 0.20
[0162] The hue of the resultant dyed fabric in Examples 47 to 50 was a brown color (Examples 47 and 48), a scarlet red color (Example 49) and a green color (Example 50). In either of the combinations of Examples 47 to 50, the dyeing rates of dye components during a dyeing step agreed well with each other, a fixing efficiency was high and a washing property was also excellent. Further, each of the resultant dyed fabrics was excellent in levelness and various fastnesses such as a fastness to light, a fastness to light with perspiration, a fastness to chlorinated water and the like.
[0163] The hue of the resultant dyed fabric in Examples 51 to 54 was a brown color (Examples 51 and 52), a scarlet red color (Example 53) and a green color (Example 54). In either of the combinations of Examples 51 to 54, the dyeing rates of dye components during a dyeing step agreed well with each other, a fixing efficiency was high and a washing property was also excellent. And, each of the resultant dyed fabrics was excellent in levelness and various fastnesses such as a fastness to light, a fastness to light with perspiration, a fastness to chlorinated water and the like.
Example 55
[0164] A dye bath was prepared by adding water to the combination and amounts of dyes (compounds) shown in Table 8, 50 parts of anhydrous sodium sulfate and 1 part of Kayaku Buffer P-7 (a pH controlling agent of Nippon Kayaku Co., Ltd.) such that the total volume was 1000 parts. The pH value of this dye bath was 7.2. 50 Parts of a cowoven fabric comprising blended cotton/rayon (50%/50%) fibers was introduced in the dye bath. After the temperature of the dye bath was increased to 100° C. over 40 minutes, the dyeing was conducted at this temperature for 30 minutes. The pH value of the dye bath remaining after dyeing was 7.0. Then, the fabric was washed with water and hot water successively, soaped in 1000 parts of an aqueous solution containing 1 part of a commercially available soaping agent at a temperature of 100° C. for 10 minutes, washed with water and dried, thereby a dyed fabric was obtained.
[0165] In Comparative Examples 4 and 5, the dyeing was conducted in the same way as that described in Example 55 except that the combination and amounts of dyes (compounds) shown in Table 8, was used, thereby a dyed fabric was obtained.
TABLE 8 reactive dyes yellow red blue formula amount formula amount formula amount Ex. 55 (11) 0.20 (7) 0.15 (9) 0.12 (10) 0.08 Comparative (25) 0.05 (7) 0.15 (9) 0.12 Ex. 4 (26) 0.15 (10) 0.08 Comparative (26) 0.15 (7) 0.15 (9) 0.12 Ex. 5 (24) 0.05 (10) 0.08
[0166] Solid Dyeing Property of Cotton/Rayon Fibers
[0167] Method of judgment: A solid dyeing of cotton/rayon fibers dyed in one bath dyeing method was judged by the naked eye.
[0168] ◯ excellent solid dyeing
[0169] X inferior solid dyeing
[0170] Hues of cotton and rayon fibers in the resultant dyed fabric and a solid dyeing property of Example 55 and Comparative Examples 4 and 5 are shown in Table 9.
TABLE 9 hue solid dyeing cotton fibers rayon fibers property Ex. 55 brown brown ◯ Comparative brown purple - violet X Ex. 4 Comparative brown purple - violet X Ex. 5
[0171] Only in the case of using the combination of compounds for dyeing as shown in Example 55, each dye component of yellow, red and blue reactive dyes showed the same dyeing property on rayon fibers. In this case, a solid dyeing property of cotton and rayon fibers dyed in one bath dying method was very excellent. Thus, the reactive dye composition of the present invention is very effective in solid dyeing of blended cotton/rayon fibers and a cowoven fabric thereof.
Example 56
[0172] A dye bath was prepared by adding water to 0.4 part of the compound of the formula (11), 0.1 part of the compound of the formula (7), 0.07 part of the compound of the formula (9), 0.05 part of the compound of the formula (10), 0.22 part of Kayalon Microester Yellow AQ-LE (trade name of Nippon Kayaku Co., Ltd., a disperse dye for polyester fibers), 0.15 part of Kayalon Microester Red AQ-Le (trade name of Nippon Kayaku Co., Ltd., a disperse dye for polyester fibers), 0.05 part of Kayalon Microester Blue AQ-LE (trade name of Nippon Kayaku Co., Ltd., a disperse dye for polyester fibers), 60 parts of anhydrous sodium sulfate and 1 part of Kayaku Buffer P-7 (a pH controlling agent of Nippon Kayaku Co., Ltd.) such that the total volume was 1000 parts. The pH value of this dye bath was 7.2. 50 Parts of a fabric comprising blended cotton/polyester fibers were introduced in the dye bath. After the temperature of the dye bath was increased to 130° C. over 40 minutes, the dyeing was conducted at this temperature for 40 minutes. The pH value of the dye bath remaining after dyeing was 6.9. Then, the fabric was washed with water and hot water successively, soaped in 1000 parts of an aqueous solution containing 1 part of a commercially available soaping agent at a temperature of 100° C. for 10 minutes, washed with water and dried, thereby a yellowish brown-dyed fabric was obtained.
[0173] When the dye composition of Example 56 was used, a washing property during a washing step was excellent. The resultant dyed fabric was levelly dyed irrespective of the nature of fibers. Various fastnesses such as a fastness to light, a fastness to light with perspiration, a fastness to washing and the like were also excellent.
Example 57
[0174] A dye bath was prepared by adding water to 1 part of the compound of the formula (11), 0.35 part of the compound of the formula (7), 0.16 part of the compound of the formula (9), 0.11 part of the compound of the formula (10), 0.3 part of Kayanol Yellow NFG (trade name of Nippon Kayaku Co., Ltd., an acid dye for nylon fibers), 0.16 part of Kayanol Floxine NK (trade name of Nippon Kayaku Co., Ltd., an acid dye for nylon fibers), 0.09 part of Kayanol Blue N2G (trade name of Nippon Kayaku Co., Ltd., an acid dye for nylon fibers), 60 parts of anhydrous sodium sulfate and 1 part of Kayaku Buffer P-7 (a pH controlling agent of Nippon Kayaku Co., Ltd.) such that the total volume was 1000 parts. The pH value of this dye bath was 7.3. 50 Parts of a fabric comprising blended cotton/nylon fibers was introduced in the dye bath. After the temperature of the dye bath was increased to 100° C. over 40 minutes, the dyeing was conducted at this temperature for 40 minutes. The pH value of the dye bath remaining after dyeing was 7.1. Then, the fabric was washed with water and hot water successively, soaped in 1000 parts of an aqueous solution containing part of a commercially available soaping agent at a temperature of 80° C. for 10 minutes, washed with water and dried, thereby a brown-dyed fabric was obtained.
[0175] When the dye composition of Example 57 was used, a washing property during a washing step was excellent. The resultant dyed fabric was levelly dyed irrespective of the nature of fibers. A fastness to light and a fastness to light with perspiration were excellent.
Example 58
[0176] The compound of the formula (11) as a yellow reactive dye, the compound of the formula (7) as a red reactive dye and the compounds of formulae (9) and (10) as blue reactive dyes were mixed in a ratio of 50%: 25%: 15%: 10% to obtain a reactive dye composition of the present invention. The dyeing was conducted in the same way as that described in Example 36 using 0.5 part of this reactive dye composition, thereby a brown-dyed fabric was obtained.
[0177] When the reactive dye composition of Example 58 was used, the dyeing rates of dye components during a dyeing step agreed well with each other. A fixing efficiency was high and a washing property was also excellent. The resultant dyed fabric was levelly dyed and excellent in fastnesses such as a fastness to light, a fastness to light with perspiration, a fastness to chlorinated water and the like.
EFFECT OF THE INVENTION
[0178] When cellulosic fibers are dyed with the disazo compound of the present invention, the dyeing with a high color yield, excellent fastnesses in various aspects, good thermal discoloring and good phototropy can be conducted with good levelness and reproducibility. Further, cellulosic fibers can be dyed with excellent reproducibility by an efficient all-in-one method.
[0179] A fabric comprising blended polyester/cotton fibers can be dyed in the co-existence of a disperse dye by a reasonable one bath/one step method.
[0180] In addition, cellulose or cellulose-containing fibers can be efficiently dyed with excellent washing property, excellent reproducibility, good levelness and high fastnesses, by using the reactive dye composition of the present invention.
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The present invention provides a disazo compound which in a free acid form is represented by the formula (1) and which has high ability to dye cellulosic fibers and attains efficient dyeing with satisfactory reproducibility; and a method of dyeing cellulosic fibers with the compound. Also provided are: a reactive dye composition comprising a compound represented by the formula (1) and a specific red reactive dye and/or a specific blue reactive dye; and a method of dyeing cellulosic fibers with the composition.
In the formula, R 1 and R 3 each represents hydrogen atom or methoxy group; R 2 and R 4 each represents hydrogen atom, methyl group, acetylamino group, ureido group, etc.; and m is 2 or 3.
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FIELD OF THE INVENTION
The present invention relates to a power transmission device that includes a torque feedback mechanism to change the position of a shift gear so as to change the speed of the transmission device. The speed of the transmission device is automatically switched to a proper value when load changes.
BACKGROUND OF THE INVENTION
A conventional power transmission device, especially for electric spinning tools, such as electric drills and electric screwdrivers, includes a multiple-stage power transmission. A speed reduction mechanism is incorporated to provide multiple speeds associated torque change in accordance with the multiplicity of stages. Generally, the speed reduction mechanism is composed of a planetary gear system and clutch or driving members that are manually controlled to switch the speed between the multiplicity of stages. Due to the manual control, an operator has to judge the situation of the tool and decide when to activate the speed reduction mechanism in order to obtain desired torque or speed. However, manual operation is apparently not a feasible way to optimize the operation efficiency of the driving motor.
Therefore, it is desired to have an automatic mechanism for switching the speed of a transmission device based on load torque in order to optimize the operation of the transmission device.
SUMMARY OF THE INVENTION
In accordance with an aspect of the present invention, there is provided an automatic speed switching mechanism for a power transmission device, which comprises a torque feedback mechanism. The torque feedback mechanism includes a pushing wheel and a sliding ring engaging the pushing wheel. A C-shaped clamp and a compression spring which is fit over the frame and retained between ridges of the frame and the clamp. The angular position of the pushing wheel is limited by a torsion spring that is fixed to the frame. The sliding ring is limited to be moved axially in the frame. The transmission mechanism has a shifting gear which has inner teeth engageable with first planet gears and second planet gears. The shifting gear has an annular groove with which a plurality of pins on the clamp engage so as to retain the shifting gear in a first, high-speed low-torque stage while the shifting gear is engaged with the two planet gears, or retain the shifting gear in a second, low-speed high-torque stage and only engaged with the second planet gears. When the load torque on the pushing wheel is smaller than the force of the torsion spring and compression spring, the shifting gear is retained at the first stage and co-rotates with the two planet gears. When the load torque is larger than the force of the torsion spring and compression spring, it rotates and pushes the sliding ring by the inclined faces so that the sliding ring pushes the shifting gear which is in the second stage and cannot rotate due to the engagement of the protrusions of the frame and the notches of the shifting gear. The speed reduction mechanism of the transmission mechanism automatically shifts the speed reduction mechanism when the load torque increases or reduces so that the mechanical efficiency of the transmission device can be increased.
The present invention will become more obvious from the following description when taken in connection with the accompanying drawings, which show, for purposes of illustration only, a preferred embodiment in accordance with the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded view of a power transmission device in accordance with the present invention;
FIG. 2 is a cross-sectional view of the power transmission device of the present invention in a first stage which is a high-speed low-torque condition;
FIG. 3 is a cross-sectional view of the power transmission device of the present invention in a second stage which is a low-speed high-torque condition, and
FIG. 4 shows that a pushing wheel of the power transmission device engaging a sliding ring.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings and in particular FIGS. 1 and 2, a power transmission device of the present invention comprises a frame 1 , a torque feedback mechanism 2 and a transmission mechanism 3 . The frame 1 comprises a cylindrical case defining a hollow chamber 11 and forming a plurality of protrusions 11 a extending inward from an inside surface of the chamber 11 . A plurality of slots 12 is defined through the wall of the frame 1 in the longitudinal direction. A plurality of ridges 13 extends from an outer surface of the frame 1 . A slit 14 is defined in the wall of the frame 1 at an open end of the chamber 11 . A plurality of axial grooves 15 is defined through the wall of the frame 1 .
The torque feedback mechanism 2 comprises a torsion spring 21 , a pushing wheel 22 , a sliding ring 23 , a C-shaped clamp 24 and a compression spring 25 . The pushing wheel 22 has a plurality of trapezoid blocks 22 a formed on an outside surface thereof. Inner threads 22 b are defined in an inner periphery of the pushing wheel 22 . A surface groove 22 c is defined longitudinally in the outer surface of the pushing wheel 22 . A plurality of trapezoid portions 23 a is formed on the sliding ring 23 . A plurality of ribs 23 b is formed on an outside surface of the sliding ring 23 . The sliding ring 23 is received in the chamber 11 of the frame 1 and fit over the pushing wheel 22 with the trapezoid portions 23 a engaging the trapezoid blocks 22 a of the pushing wheel 22 and the ribs 23 b received in the axial grooves 15 of the frame 1 whereby the sliding ring 23 is movable longitudinally in the chamber 11 of the frame 1 . A plurality of lugs 24 a is formed on an outer surface of the clamp 24 and a plurality of pin holes 24 b is defined through the clamp 24 and located corresponding to the slots 12 in the frame 1 . Each pin hole 24 b receives a pin 24 c . The compression spring 25 is fit over the frame 1 and retained between the rides 13 of the frame 1 and the lugs 24 a of the clamp 24 . The compression spring 25 is deformable by the movement of the clamp 24 in the axial direction so as to provide a longitudinal force. The torsion spring 21 has a first end 21 a engaging the surface groove 22 c of the pushing wheel 22 , and a second end 21 b engaging the slit 14 of the frame 1 so as to resiliently maintain a position relationship between the pushing wheel 22 and the frame 1 .
The transmission mechanism 3 includes an input gear 31 , a front speed reduction gear 32 , a shifting gear 33 and a rear speed reduction gear 34 . The input gear 31 is connected to an input power source that is not shown. The front speed reduction gear 32 has outer teeth and includes a plurality of planet gears 32 a rotatably mounted to one surface thereof and a driving gear 32 b on an opposite surface of the front speed reduction gear 32 for transmitting mechanical power to the rear speed reduction gear 34 . The planet gears 32 a engage both inner teeth 22 b of the pushing wheel 22 and the input gear 31 so as to form a planetary speed reduction system. The shifting gear 33 has inner teeth and an annular groove 33 a is defined in an outer surface of the shifting gear 33 f . A plurality of notches 33 b is defined in the outer surface of the shifting gear 33 at an end thereof. The pins 24 c extend through the slots 12 in the frame 1 and engaging with the annular groove 33 a . The protrusions 11 a of the frame 1 are engageable with the notches 33 b for rotatably fixing the shifting gear 33 in the chamber 11 of the fire 1 at a low-speed high-torque condition. The rear speed reduction gear 34 is a circular disk having a surface on which a plurality of planet gears 34 a is rotatably mounted. An output gear 34 b is formed on an opposite surface of the circular disk. The planet gears 34 a engage the drive gear 32 b and the inner teeth of the shifting gear 33 so as to form a planetary speed reduction mechanism.
The receiving chamber 11 receives the transmission mechanism 3 and the torque feedback mechanism 2 in sequence. In a first stage which is a high-speed low-torque condition in the illustrated embodiment, the clamp 24 is retained in an initial position by the compression spring 25 where the pins 24 c are located at an upper section of the slots 12 . Due to the engagement between the pins 24 c and the annular groove 33 a of the shifting gear 33 , the shifting gear 33 is located at a topmost position with respect to the frame 1 . Under this circumstance, the trapezoid blocks 22 a of the pushing wheel 22 and the trapezoid portions 23 a of the sliding ring 23 completely engage each other. Angular position of the pushing wheel 22 with respect to the frame 1 is retained by the torsion spring 21 while axial position of the sliding ring 23 is retained by the shifting gear 33 , which is retained by the compression spring 25 .
Referring to FIGS. 3 and 4, when the a large torque is required, the input gear 31 of the transmission mechanism 3 increases the torque transmitted to the front speed reduction gear 32 , which in turn causes the planet gears 32 a of the front speed reduction gear 32 to impart a reaction torque in reverse direction to the inner teeth 22 b of the pushing wheel 22 so as to rotate the pushing wheel 22 . Nevertheless, the rotation of the pushing wheel 22 is restrained by the force of the torsion spring 21 and the compressing spring 25 . Inclined side faces of the trapezoid blocks 22 a of the pushing wheel 22 induce a camming action on inclined side faces of the trapezoid portions 23 a of the sliding ring 23 whereby, when the reaction torque of the pushing wheel 22 is large enough, the sliding ring 23 is forced to move axially by the camming action of the inclined side faces of the trapezoids 22 a , 23 a and guided by the engagement between the ribs 23 b and the axial grooves 15 . The sliding ring 23 pushes the shifting gear 33 , which, due to the engagement between the pins 24 c and the annular groove 33 a , drives the clamp 24 to axially move in unison therewith. The clamp 24 is resiliently biased by the compression spring 25 and a reaction force against the movement of the clamp 24 is induced. Under this circumstance, when the torque applied to the pushing wheel 22 by the front speed reduction gear 32 reaches a predetermined threshold value, the trapezoid portion 23 a of the sliding ring 23 moves along the inclined sides of the trapezoid blocks 22 a of the pushing wheel 22 , bringing the sliding ring 23 away from the pushing wheel 22 . This disengages the shifting gear 33 from the front speed reduction gear 32 and the shifting gear 33 is now only engaging the planet gears 34 a . A further speed reduction is obtained and a maximum torque is induced on the output gear 34 b . The shifting gear 33 now reaches the bottom position to allow the notches 33 b to engage the protrusions 11 a in the chamber 11 of the frame 1 thereby fixing the shifting gear 33 .
The torque of the shifting speed reduction mechanism is determined by the torsion spring 21 and the compression spring 25 . This can be changed by replacing the springs 21 , 25 with new ones having different spring constants.
The automatic shifting device can be used as a power transmission device in electric drills. When drilling, if a small amount of torque is required, the torque applied on the pushing wheel 22 from the front speed reduction gear 32 cannot overcome the resistant force from the torsion spring 21 and the compression spring 25 , so that the pushing wheel 22 does not rotate. The sliding ring 23 and the shifting gear 33 are retained in their first stage of speed. The shifting gear 33 is engaged with the planet gears 34 a of the rear speed reduction gear 34 and the front speed reduction gear 32 . The shifting gear 33 co-rotates with the front speed reduction gear 32 and the rear speed reduction gear 34 . The result is located in the maximum value of the curve of the torque vs. revolution. If a large torque is required, the input gear 31 increases the torque gradually and the torque applied onto the pushing wheel 22 from the front speed reduction gear 32 overcomes the resistant force from the torsion spring 21 and the compression spring 25 . The pushing wheel 22 rotates when the torque increases and the sliding ring 23 and the shifting gear 33 are in its lower most position. The shifting gear 33 is disengaged from the front speed reduction gear 32 and engaged with the planet gears 34 a of the rear speed reduction gear 34 . The shifting gear 33 is not rotated due to the engagement of the notches 33 b and the protrusions 11 a . This provides the first stage of speed and the result is located in the maximum value of the curve of the torque vs. revolution.
While we have shown and described the embodiment in accordance with the present invention, it should be clear to those skilled in the art that further embodiments may be made without departing from the scope of the present invention.
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A power transmission device that is capable of automatic speed switching according to external load is disclosed, including a frame in which a transmission mechanism and a torque feedback mechanism are received. The torque feedback mechanism includes a torque resistant member so that when the load torque is smaller than its resistant torque, the speed reduction mechanism of the transmission mechanism is retained at a first, high-speed low-torque stage. When the load torque is larger than its resistant torque, a sliding ring of the torque feedback mechanism pushes a shifting gear so that the sped reduction mechanism is shifted to a second, low-speed high-torque stage. The speed reduction mechanism automatically shifts the speed reduction mechanism when the load torque increases or reduces so that the mechanical efficiency of the transmission device can be increased.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a division of co-pending U.S. application Ser. No. 10/756,030, filed Jan. 13, 2004, which claims the benefit of U.S. Application No. 60/441,638, filed on Jan. 22, 2003. The entire contents are incorporated in their entirety herewith.
[0002] The present invention relates to a method of forming a multiwell filtration plate. More particularly, it relates to a method of forming a multiwell filtration plate using glue and heat to bond the filter to the plate.
BACKGROUND OF THE INVENTION
[0003] Multiwell plates have existed for many years. Most are in multiples of 6, 8 or 12 such as 24, 96 or 384 wells in a single plate.
[0004] Methods to attach the filter material to the bottom of the plate so as to seal off the bottom of each well by the porous filter material have included mechanical means such as friction fitting of individual pieces in each well or clips or edge bands to hold the filter material against the bottom; adhesives, heat bonding, over molding and thermal bonding via an under drain.
[0005] Each approach has its drawbacks. Simply stuffing a cut piece into each well is time consuming and provides less than 100% sealing accuracy. With the 384 well format, this approach is impractical. Likewise, using a clamp or edge band allows the filter material in the middle to separate from the bottom of the wells allowing for cross talk or contamination between wells.
[0006] Adhesives require proper placement and alignment of the adhesive and filter material so as to prevent adhesives from spreading into the area of filter inside the well that reduces its active filtration area. Moreover, adhesives do not extend through the entire thickness of the filter material allowing for cross talk and contamination between wells through the filter material beyond the glue.
[0007] Overmolding or insert molding eliminates cross talk and forms an integral well, but it is costly to set up and run and is a relatively slow process. Moreover, its use at smaller well sizes (384+) is limited by the ability to form channels and gates for the introduction of the molten plastic in that small area.
[0008] Using thermal energy to bond and seal the filter to the bottom of the plate is difficult. Achieving 100% sealing of the filter to the bottom by thermal bonding is not possible. Some filter materials do not bond properly to the material of the plate, limiting this approach to only compatible materials. Other filters are extremely heat sensitive making this approach untenable as the filter structure tends to collapse to such an extent that active filtration area is compromised.
[0009] Using thermal energy to trap the filter between an upper plate and lower plate is possible. Again, it is limited in speed and cost to set up and run. Moreover, it requires the use of a fixed design for a bottom plate that may either be unnecessary or improperly suited for the desired application.
[0010] What is desired is a process that is fast, inexpensive and reliable for making a multiwell filtration plate where each well is integrally sealed about its edge and no cross talk or contamination between wells is possible. The present invention provides such a process.
SUMMARY OF THE INVENTION
[0011] The present invention comprises a process for forming integral sealed wells in a multiwell plate by first gluing a filter material to the bottom of a multiwell plate containing a series of two or more wells open at the top and bottom of the plate and after gluing the filter in place sealing and bonding the filter material by a heat sealing process along the bottom surface of the plate so as to collapse the porous structure of the filter in the areas outside of the wells. Optionally, a director plate may then be glued to the filter side of the plate along the collapsed regions. The process provides a multiwelled device having a filter attached to its bottom surface wherein each well is integral and fully sealed so that no cross talk or contamination occurs between adjacent wells.
IN THE DRAWINGS
[0012] FIG. 1 shows a first embodiment of the invention in cross-sectional view.
[0013] FIG. 2 shows a close up cross-sectional view of the embodiment of FIG. 1 taken along lines 1 - 1 .
[0014] FIG. 3A shows a planar view of a bottom surface of the present invention as described in Example 2.
[0015] FIG. 3B shows a planar view of a bottom surface of a comparative plate as described in Example 2.
[0016] FIG. 4A shows a planar view of a bottom surface of the present invention as described in Example 3.
[0017] FIG. 4B shows a planar view of a bottom surface of a comparative plate as described in Example 3.
[0018] FIG. 5 shows a top down planar view of a 345 well, 96 active well plate design mentioned in Example 3.
DETAILED DESCRIPTION
[0019] The present invention is a process for forming a multiwell plate having a filter attached to its bottom surface in a manner that provides an integral seal around the outer periphery of each well.
[0020] FIG. 1 shows a partial cross sectional view of a first embodiment of the present invention. As shown, plate 2 has a top surface 4 , a bottom surface 6 and a thickness 8 between. A series of wells 10 are formed through the thickness 8 of the plate 2 . Each well 10 has an upper opening 12 corresponding with the upper surface 4 of the plate and a lower opening 14 corresponding with the lower surface 6 of the plate and the well 10 forming a through hole through the thickness 8 of the plate 2 from the top opening 12 to the bottom opening 14 .
[0021] A filter sheet 16 is attached to the bottom surface 6 of the plate 2 such that it covers all of the bottom openings 14 of the wells 10 and the surrounding bottom surface 6 of the plate. The area of the filter 16 , which is in contact with the bottom surface 6 , has been sealed and adhered to the bottom surface 6 by a sealed area 18 .
[0022] FIG. 2 shows a close up cross sectional view of the embodiment of FIG. 1 . The plate 2 again has a top surface 4 , a bottom surface 6 , a thickness 8 , series of wells 10 and the membrane 16 attached to the bottom surface 6 as described in relationship to FIG. 1 . As shown in FIG. 2 , the sealing area 18 is formed of two aspects; a glue attachment 20 between the bottom surface 6 of the plate 2 and at least a portion of the thickness of the filter 16 and a heat seal 22 formed between the outer surface 24 of the filter 16 and the glue attachment 20 .
[0023] The heat seal, at the very least, creates a liquid impermeable barrier around each of the wells. Preferably, it causes the porous structure of the filter outside of the wells to substantially collapse reducing the porosity in those areas to substantially nothing. This coupled with the glue attachment effectively forms an impermeable dam around the outer periphery of each well so that the liquid in a well does not move laterally to an adjacent well, thus eliminating cross talk and the potential for contamination.
[0024] The method for forming a plate of FIG. 1 is as follows: One takes a plate having a top surface, a bottom surface and defined thickness between the two surfaces. The plate has a series of wells running through the thickness of the plate and having a top and bottom opening corresponding with the top and bottom surface of the plate.
[0025] An adhesive is applied to the bottom surface of the plate (e.g. to the solid portions of the plate bottom) and the filter is then placed on top of the adhesive and compressed to make intimate contact with the adhesive. Preferably, the adhesive penetrates a portion of the thickness of the filter material to establish a good bond between the plate bottom and the filter. Alternatively, one could apply the glue via a robotic X/Y applicator to the filter and then attach the filter to the plate. However in this embodiment, one must carefully align the filter with the plate to ensure good sealing. The use of alignment pins, pins/holes, notches, marks and the like are useful if one decides to use this alternative embodiment.
[0026] After curing, the filter is then subjected to a heat sealing step. The area of the filter that is directly over a solid portion of the plate bottom is heat sealed. The area of the membrane that is over the open wells in the plate bottom remain substantially free of either the adhesive or the heat bonding so as to retain the maximum area of filtration for each well.
[0027] If desired, an under drain containing collector wells or directing spouts that are in register with the wells of the plate may then be attached to the bottom of the plate using an adhesive, heat weld, vibration weld and the like.
[0028] The plate may be any plate commonly used in multi well filtration. It should contain a series of two or more wells. Preferably, it contains a series of wells that are at least 12, preferably 24, more preferably at least 96, or at least 384 and even up to 1,536 wells per plate. The plate should be relatively rigid or self-supporting to allow for easy handling during manufacturing and easy handling during use by the end user (a human or a robot). Additionally, its dimensions should conform to those set out by the Society for Biological Standards so that it can be used in all robotic applications. Preferably the plate may be made of polymeric, especially thermoplastic materials, glass, metallic materials, ceramic materials, elastomeric materials, coated cellulosic materials and combinations thereof such as epoxy impregnated glass mats. In a more preferable embodiment, the plate is formed of a polymeric material including but not limited to polyethylene, acrylic, polycarbonate and styrene. The wells can be made by injection molding, drilling, punching and any other method well known for forming holes in the material of selection. Such plates are well known and commercially available from a variety of sources in a variety of well numbers and designs. Most common are 96 and 384 well plates.
[0029] The well format will be determined by the end users needs, but it can have numerous configurations and the wells do not necessarily need to be all of the same shape or size. For example, the wells of the present invention may have round, rectangular, teardrop, square, polygonal and other cross-sectional shapes or combinations of them. Virtually any shape that is required for the product may be provided. Typically, it has the wells arranged in uniformly spaced rows and columns for ease of use.
[0030] Ultrafiltration (UF) filters, which may be used in this process, can be formed from the group including but not limited to polysulphones, including polysulphone, polyethersulphone, polyphenylsulphones and polyarylsulphones, polyvinylidene fluoride, and cellulose and its derivatives, such as nitrocellulose and regenerated cellulose. These filters typically include a support layer that is generally formed of a highly porous structure. Typical materials for these support layers include various non-woven materials such as spun bounded polyethylene or polypropylene, paper or glass or microporous materials formed of the same or different polymer as the filter itself. Alternatively, the support may be an openly porous, asymmetric integral portion of the ultrafiltration filter that may either be formed with or without macrovoids. Such filters are well known in the art, and are commercially available from a variety of sources such as Millipore Corporation of Bedford, Mass.
[0031] Preferred UF filters include regenerated cellulose or polysulphone filters such as YMTM or Biomax® filters available from Millipore Corporation of Bedford, Mass.
[0032] Representative suitable microporous filters include nitrocellulose, cellulose acetate, regenerated cellulose, polysulphones including polyethersulphone and polyarylsulphones, polyvinylidene fluoride, polyolefins such as ultrahigh molecular weight polyethylene, low density polyethylene and polypropylene, nylon and other polyamides, PTFE, thermoplastic fluorinated polymers such as poly (TFE-co-PFAVE), polycarbonates or particle filled filters such as EMPORE® filters available from 3M of Minneapolis, Minn. Such filters are well known in the art and available from a variety of sources, such as DURAPORE® filters and EXPRESS® filters available from Millipore Corporation of Bedford, Mass.
[0033] The filter material may also be formed of glass fibers or mats, woven plastics and non-woven plastics such as TYPAR® non-wovens available from DuPont de Nemours of Wilmington, Del.
[0034] The filter may be in the form of an isotropic, track etched material (such as ISOPORE™ membranes), a cast membrane, preferably a microporous or ultrafiltration membrane such as DURAPORE® membranes, EXPRESS® membranes or EXPRESS® PLUS membranes available from Millipore Corporation of Bedford, Mass., non-woven filter materials such as spun bonded polypropylene, polyethylene or polyester (Typar® or Tyvek® paper), PTFE resin membranes and the like.
[0035] A variety of adhesive bonding processes are envisioned and include light curing, air curing, hot melt adhesion, solvent adhesion and other such methods as are well known to one of ordinary skill in the art. Those of ordinary skill in the art would appreciate other means of adhering two layers together.
[0036] The adhesive can be any one that is capable of bonding the filter to the plate bottom. Suitable adhesives include but are not limited to solvent based adhesives, crosslinking adhesives, such as room temperature vulcanizable silicones, epoxies, including light curable epoxies such as UV light curable epoxies , hot melt adhesives and the like.
[0037] Preferably, a rapid curing adhesive such as a light curing, cyanoacrylate or thermally activated adhesives are preferred because the product can move continuously through a manufacturing process without the requirements of batch processing. The light curing adhesives are more preferred as the adhesive for attaching the filter to the plate. This is because this type of adhesive has been found to provide a liquid tight seal with a large variety of filters and plate materials and to do so in a continuous manufacturing process. The light curing adhesives such as 3201 and 3211 from Loctite Corporation works well. Other light curing adhesives are well known and readily available from companies such as Dymax of Torrington Conn., Masterbond of Hackensack, N.J., Permabond of Engelwood, N.J. and others.
[0038] While light cured adhesives are preferred due to their ease of use, other adhesive systems such as two part epoxies and solvent based adhesive systems can be used successfully in the invention especially when the materials are found to be compatible.
[0039] When using adhesives it is required that the adhesive be suitable for bonding to both the plastic part and to the filter and not have any adverse effect on the assay or filter performance.
[0040] It is preferred to use adhesives with relatively high viscosity (typically greater than 5000 cps, preferably greater than 7500 cps and more preferably about 10,000 cps), so that the adhesive does not migrate to areas of the filter that otherwise would be used in the filtration process. Any adhesive that migrates outside the seal area will reduce the effective filter area. One high viscosity adhesive is the Loctite 3211 and it has been found suitable for use in this invention.
[0041] Alternatively, one may use lower viscosity adhesives in combination with the use of masks to prevent the flow of adhesives to the area of effective filter. One may also form a series of troughs in the bottom of the plate to hold the adhesive and have the filter placed on top of the troughs to contact the adhesive in the proper areas.
[0042] The method of forming the structure of the present invention is to use heat or a combination of heat and pressure to selectively collapse porous areas of the filter that lie over the solid portions of the bottom of the plate and to maintain the porous structure of the filter that lies over the wells of the plate. The selection of heat or heat and pressure is determined by the porous structure material and the desires of the designer. It is preferred with polymeric materials to use a combination of heat and pressure in forming the device.
[0043] In a typical method for making the present invention, one determines which process one will use and then forms a template in the desired shape and pattern for the desired product. For example, one simply measures the bottom of the plate on to which the filter is to be attached and forms a template for that dimension.
[0044] The template is then placed against the filter after it has been glued to the plate and a choice of heat or heat and pressure is applied to the filter for a period of time sufficient to form the collapse of the porous material in the areas where the filter lies over a solid portion of the plate. Typically, the template is a flat, solid surface although it doesn't need to be. Alternatively, the template may contain a pattern that corresponds to the solid surface of the plate to which the filter is sealed. For example in 384 well plates, the wells are typically square and a grid-like template where the grids of the template correspond to the solid portions of the plate can be used.
[0045] When using heat, one should select a temperature which is sufficient to cause the pores in the selected areas to collapse but not to cause the pores is the others areas to collapse. This allows the areas that are heated treated to be rendered substantially non-porous, preferably non-porous. The specific temperature is dependent upon the polymer used. However, the temperature should be from well before the structure begins to deform to the melting point of the structure. Alternatively, one can use a temperature from about 25° C. to about 500° C., preferably from about 25° C. to about 300° C. and more preferably from about 50° C. to about 200° C. for a time sufficient to cause collapse of the porous structure. The time can vary depending on the temperature used but can be in the range of about 1 second to 60 minutes, preferably between about 1 seconds and about 30 minutes and more preferably between about 2 seconds and about 10 minutes.
[0046] The use of a laser may alternatively be made in performing the heat bonding step. Any laser that provides the necessary level of heat may be used. One such device is a Synrad CO2 laser. The power at which it is used depends upon the materials involved, the laser selected and the desired depth of the laser penetration. For the Synrad CO2 laser, a power of about 10 watts is sufficient to provide the desired effect.
[0047] When using the combination of heat with pressure, one should use sufficient pressure to cause the collapse of the pores in the selected area without adversely affecting the pores in the other areas. The amount of pressure used can vary depending on the amount of surface area to be collapsed, time, temperature and the strength of the plate, but one can typically use from about 10 psi to about 1,000 psi.
[0048] The template can be made of a material normally used in heating applications. Metals such as stainless steel or aluminum are preferred as they easily conduct heat. Various plastics such PTFE, polyethylene, especially ultrahigh molecular weight polyethylene (UPE), polypropylene or epoxies can be used to make templates as well. Other materials such as fiberglass or carbon composites can be used to make templates. All that is required is that the material have sufficient strength and heat conductivity to withstand the use. The template may also have a non-stick surface such as a PTFE coating in order to ensure easy removal of the formed structure from the template.
[0049] The following example shows the formation and use of one embodiment of the present invention.
EXAMPLE 1
[0050] 5 series of 10 Millipore Multiscreen® polystyrene plates were obtained. Each series was sealed with a HVPP filter available from Millipore Corporation of Bedford, Mass. to each series of plates in the following manner:
(1) Glued only (3201 light curable adhesive from Loctite Corporation); (2) Glued, followed by a laser cut (using a Synrad CO2 laser) around the periphery of each well; (3) Heat sealed only, using two separate heat seal steps at 375° F. for 4 seconds at 70 psi with the plate being turned 180° between seals. (4) Same as (3) followed by a laser cutting (using a Synrad CO2 laser) around the periphery of each well; and (5) Glued as in (1) followed by the heat sealing process of (3).
[0056] The integrity of the wells on each plate in each of the series was tested by applying a vacuum at 20″ mercury to the underside of the membrane.
[0057] 15 microliters (15 μl) of liquid (MILLI-Q® water) was added to each well and a vacuum was applied to draw the liquid through the filter into a collection well positioned below it. A product was deemed to be suitable if 12 or more μl of liquid was collected in the collection plate.
[0058] For Series 1 and 2 liquid collection was below 12 μl and liquid was found to migrate laterally in the filter between wells and to collect in dead spots in the filter.
[0059] For Series 3 and 4, some wells collected 12 or more μl liquids, but lateral movement in the filter was still a problem.
[0060] For Series 5, which corresponds to the present invention, all wells were integral and passed at least 12 μl of liquid to the collection wells. In addition, no liquid was found to have moved laterally in the filter nor was any liquid found in the dead space of the filter (filter area between the wells).
EXAMPLE 2
[0061] Two 384 well plates, Multiscreen® polystyrene plates, available from Millipore Corporation of Bedford, Mass., were obtained. Each was sealed with a HVPP filter available from Millipore Corporation of Bedford, Mass. by a gluing procedure using 3201 light curable adhesive from Loctite Corporation. The glue was applied to the ribs of the bottom surface of the plates and then the membrane was applied over it. Hand pressure was applied to obtain a good seal and the glue was cured with UV light.
[0062] One plate A was then heat sealed by a laser cut (using a Synrad CO2 laser at an energy level of 10.4 watts) around the periphery of each well. The other plate B was left as is. 100 μl of a 0.1% (w/v) Ponceau S in 5% (w/v) acetic acid (Sigma Catalog # P7170) was added to one well of each plate. The liquid was allowed to stand at room temperature for fifteen minutes.
[0063] Any remaining liquid was then removed by pipette from the well and the plate was turned over and the bottom surface was observed and photographed. FIG. 3A shows plate A according to the present invention. FIG. 3B shows plate B.
[0064] As can be clearly seen from FIGS. 3A and B, the plate according to the invention ( FIG. 3B ) is only stained in the area of the one well that contained the solution. The well of B allowed fluid to spread laterally through the filter to adjoining wells (53 wells at least partially colored).
EXAMPLE 3
[0065] Two 345 well plates, each containing 96 active wells, Multiscreen® polystyrene plates, available from Millipore Corporation of Bedford, Mass., were obtained. FIG. 5 shows such an arrangement of the plate. In this design, only one well, 100 , of the four adjacent wells 101 , 102 , 103 ,is active, the others being covered by plastic to render them unusable. Each plate was sealed with a HVPP filter available from Millipore Corporation of Bedford, Mass. by a gluing procedure using 3201 light curable adhesive from Loctite Corporation. The glue was applied to the ribs of the bottom surface of the plates and then the membrane was applied over it. Hand pressure was applied to obtain a good seal and the glue was cured with UV light.
[0066] One plate A was then heat sealed by a flat heater of a size and shape to fit the bottom surface of the plate in two separate heat seal steps at 375° F. for 4 seconds at 70 psi with the plate being turned 180° between seals around the periphery of each well. The other plate B was left as is.
[0067] 100 μl of a 0.1% (w/v) Ponceau S in 5% (w/v) acetic acid, (Sigma Catalog # P7170) was added to one well of each plate. The liquid was allowed to stand at room temperature for fifteen minutes.
[0068] Any remaining liquid was then removed by pipette from the well and the plate was turned over and the bottom surface was observed. FIG. 4A shows plate A according to the present invention. FIG. 4B shows plate B.
[0069] As can be clearly seen from FIGS. 4A and B, the plate according to the invention ( FIG. 4A ) is only stained in the one well that contained the solution. The well of 4 B allowed fluid to spread laterally through the filter to 87 (fully or at least partially) adjoining wells.
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A method of forming a multiwell filtration plate comprising of first gluing a filter to a major surface of a multiwell plate so as to close off one entrance to the wells of the plate. The filter is then heat sealed so as to collapse the pores of the filter in the area between the wells so as to prevent lateral migration of fluid from one well to another.
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RELATED CASES
Cross reference is made to the following application incorporated by reference herein for its teaching: U.S. patent application Ser. No. 09/119,023 entitled “Improved Method Of Compressing JPEG Files” to Ricardo L. de Queiroz.
BACKGROUND OF THE INVENTION AND MATERIAL DISCLOSURE STATEMENT
The transmission of electronic data via facsimile machines and similar devices has become quite common. Efforts to transmit significantly larger volumes of this data within a substantially shortened period of time are constantly being made. This is true not only to allow for data to be sent from one location to another at faster speeds and thereby causing less inconvenience to the user, but to enable more complex data to be transmitted between the same locations without drastically increasing the required transmission time. For example the facsimile transmission time for a detailed halftoned image will be many times more than that of a simple sheet of black text on a white page when using the same fax machine. By the same token, fax transmission of a color image will require an even greater amount of time than its greatly detailed halftoned counterpart.
Without any form of data reduction, transmission of color image data files via facsimile would require extensive resources—very fast modems and/or large buffers—and would still take a great deal of time, thereby causing such transmission to become very expensive and therefore, impractical. Instead, the transmission of color image data via fax is typically accomplished using some form of data compression prior to transmission.
The JPEG (Joint Photographic Experts Group) standard provides a well known method of compressing electronic data. JPEG uses the discrete cosine transform (DCT) to map space data into spatial frequency domain data. Simply put, the first step in JPEG compression is to transform an 8×8 block of pixels into a set of 8×8 coefficients using the DCT. The DCT with the lowest frequency is referred to as the DC coefficient (DCC), and the remaining coefficients are AC coefficients (ACCs). The DCC and ACCs are quantized—divided by an integer referred to as the “step size” and rounded to the nearest whole number. The losses that occur during JPEG compression typically occur during the quantization step. The magnitude of this loss is obviously dependent upon the step size selected and the resulting amount of round-off required to perform quantization.
Next, the quantized coefficients are arranged in a one dimensional vector by following a selected path (i.e. zigzag) through the 8×8 block of quantized coefficients. The DCC is typically the first value in the vector. Ordinary JPEG compression typically includes replacing the quantized DCC with the difference of its actual value minus the DCC of the previous block, to provide a differential DCC. Finally, the vector is encoded into a bit stream through a sequence of Run Length Counting (RLC) operations, combined with Variable Length Codes (VLC) to produce a compressed data stream.
Fax transmission of color image data is often accomplished by scanning the image at the sending fax to generate digital color image data, subjecting this digital color image data to JPEG compression and then transmitting the compressed digital color image data over telephone lines to the receiving fax. Since color image data is so complex, high compression ratios must usually be applied in order to complete the transmission within an acceptable time frame. High compression ratios lead to more data loss, which typically occurs at the higher end of the frequency range. Further, the imaging devices typically included with fax machines in the lower end of the market usually include thermal ink-jet printers and would likely use error diffusion halftoning techniques. The halftoning that occurs when using a thermal ink jet printer results in an additional loss of high frequency data. Thus, much of the detail in the original image that is preserved and transmitted will never actually be viewed by the ultimate user.
The “sending” portion of fax transmission includes scanning the original image, generation of a corresponding digital image, and any one of a number of data reduction techniques, most notably some form of data compression. Once these steps are completed, the compressed data is transmitted serially to the receiving fax in a bit stream. The length of the bit stream used to describe the image is inversely proportional to the amount of compression that has been applied. Thus, if the compression ratio is large the length of the bit stream used to describe the image will be very short, resulting in a substantial reduction in the transmission time for the data stream.
With this in mind, successful fax transmission requires a proper correspondence between the compression ratio being applied to the image and the clock speed of CPU of the sending fax. In other words, if the compression ratio is smaller than necessary for a given CPU speed the data will have to wait to be transmitted, and an appropriately sized buffer will be required. On the other hand, if the compression ratio is high relative to the CPU speed the modem will become idle waiting for the CPU to complete image processing and transmit more data. Since modems are typically configured to detect a large lapse in data transmission as the end of transmission, this large gap typically causes them to disconnect. Thus, it is advantageous to continue the stream of data from the sending fax to the receiving fax, and eliminate gaps in the data stream. One way to do this is obviously to implement a faster JPEG compressor which can keep the data moving through the modem even if a high compression ratio is used. However, this solution results in significant cost increases and is often impractical. Thus, it is advantageous to provide a continuous stream of data during transmission of a color facsimile by implementing a faster data compressor without having to resort to the purchase of more expensive equipment.
The following disclosures may be relevant to aspects of the present invention:
U.S. Pat. No. 5,737,450 to Hajjahmad et al. issued Apr. 7, 1998 discloses a method and apparatus for applying an image filter to an image signal where image data terms, corresponding to the image signal, are converted by means of an overlapping operation and a scaled forward orthogonal transformation to form frequency coefficient matrices, the image filter is converted by means of a descaled orthogonal transformation to form a descaled frequency filter matrix, and the frequency coefficient matrices are multiplied by the descaled frequency filter matrix to form filtered coefficient matrices for conversion into a filtered image signal by means of an inverse orthogonal transformation process.
U.S. Pat. No. 5,699,170 to Yokose et al. issued Dec. 16, 1997, discloses an image communication system wherein transmission of an image between an image transmission apparatus and an image reception apparatus which include image output sections having different performances can be performed without making an inquiry for the performance prior to transmission is disclosed. An image is inputted by an image input section and sent to a hierarchization section in the image transmission apparatus. The hierarchization section converts the inputted image into hierarchic communication data and transmits hierarchized data to a selection section of the image reception apparatus. The selection section extracts only necessary data from the hierarchic communication data transmitted thereto in accordance with the performance of an image output section of the image reception section and then sends the necessary data to the image output section after, if necessary, they are converted into image data. The image output section visualize the image data transmitted thereto from the selection section.
U.S. Pat. No. 5,642,438 to Babkin issued Jun. 24, 1997 discloses image compression implementing a fast two-dimensional discrete cosine transform. More specifically, Babkin discloses a method and apparatus for the realization of two-dimensional discrete cosine transform (DCT) for an 8×8 image fragment with three levels of approximation of DCT coefficients. “JPEG: Still Image Compression Standard”, New York, N.Y., Van Nostrand Reinhold, 1993 by W. B. Pennebaker and J. L. Mitchell.
All of the references cited herein are incorporated by reference in their entirety for their teachings.
Accordingly, although known apparatus and processes are suitable for their intended purposes, a need remains for image compression implementing a two-dimensional discrete cosine transform using a fast JPEG compressor based on a modified two-dimensional discrete cosine transform to compress digital image data thereby improving the efficiency of serial data transmission.
SUMMARY OF THE INVENTION
The present invention relates to a method of improving the speed and efficiency of electronic data compression. The method comprises obtaining input image data which includes discrete values that represent light intensity in an image. Then applying a first transform to the input image data to produce a first transform result. This is followed by comparing the first transform result to a threshold. Finally, a either second transform is applied to the first transform result, or the substitution of a zero value for the first transform result is used to generate approximation data.
In accordance with another aspect of the invention there is provided a method of transmitting a facsimile of an original image from a sending location to a receiving location. The method comprises acquiring the original image and generating digital image data therefrom, wherein the digital image data includes pixel values which represent the light intensity of the original image. Then applying a first transform to the input image data to produce a first transform result. This is followed by comparing the first transform result to a threshold. Then in generating approximation data which provides an estimated value of image light intensity, either a second transform is applied to the first transform result, or a zero value is substituted for the first transform result. Finally the output image data is derived from the approximation data.
BRIEF DESCRIPTION OF THE DRAWINGS
Other features and advantages of the present invention will become apparent as the following description proceeds and upon reference to the drawings, in which:
FIG. 1 is a generalized block diagram illustrating general aspects of a facsimile machine that may be used to practice the present invention.
FIG. 2 contains a schematic illustration of the steps used to carry out a JPEG compression scheme.
FIG. 3 is a detailed illustration of an example of a labeling configuration of an 8×8 block of pixels.
FIG. 4 contains a detailed illustration of the labeling configuration of DCT coefficients obtained by application of a discrete cosine transformation to the 8×8 block of pixels illustrated in FIG. 3 .
FIG. 5 illustrates one example of the manner in which the DCT coefficients of FIG. 4 may be labeled after quantization.
FIG. 6 depicts a “zig zag” pattern, one embodiment of the manner in which quantized pixels may be selected for placement into a one dimensional vector.
FIG. 7 contains a schematic illustration of one way the present invention may be implemented in a JPEG compression technique.
FIG. 8 shows a quantization table and derived threshold table.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention is directed to a method and apparatus for compressing complex digital image data to enhance the efficiency of data transmission.
Referring now to the drawings where the showings are for the purpose of describing an embodiment of the invention and not for limiting same, FIG. 1 is a block diagram showing structure of an embodiment of a facsimile (fax) apparatus 10 according to the present invention. Fax 10 includes a CPU 12 for executing controlling processes and facsimile transmission control procedures, a RAM 14 for controlling programs and a display console 16 with various buttons and/or switches for controlling the facsimile apparatus and LCDs or LED's for reviewing the status of system operation. A scanner 20 is also included for acquiring an original image and generating image data therefrom. Image processing unit 22 is included to perform encoding and decoding (compression and decompression) processes between an image signal and transmitted codes. Significantly for purposes of this invention, fax 10 includes or interfaces with a modem 24 , which is a modulating and demodulating device that transmits and receives picture information over telephone lines to a compatible receiving device 26 , such as another facsimile machine, a printer, computer terminal or similar apparatus.
As stated above, image processing unit 22 is used to compress and decompress image signals and transmitted codes. One common method of compressing and decompressing image signals is through use of the JPEG (Joint Photographic Experts Group) standard described in detail with reference to FIG. 2 . An original image is scanned by fax 10 to generate a corresponding digital image. The digital image is separated into 8×8 blocks 102 of picture elements 120 or “pixels” which indicate the intensity of the light that is measured at discrete intervals throughout the surface of the page. For example, a spot that is covered with black ink will not reflect any light. The value of the pixel 120 will typically be 0 at that location. On the other hand, a spot that is completely uncovered by ink will reflect the color of the page on which the image resides. Assuming the sheet paper on which the image has been placed is white, the measured light intensity of the pixel 120 would be 1 at that spot. Gray areas, such as those which represent color or black and white halftoned areas of the image would register a light intensity somewhere between 0 and 1. The values of the pixels 120 in block 102 are transformed through DCT into a set 106 of 8×8 coefficients as indicated in step 104 . The DCT coefficient with the lowest frequency is referred to as the DC coefficient (DCC), and the remaining coefficients are AC coefficients (ACCs). The DCC and ACCs are quantized—each coefficient is divided by a predetermined whole number referred to as the “step size” at step 108 and then a selected pattern (usually a “zigzag”) is followed through the 8×8 block of quantized coefficients 110 as indicated in step 112 to place the coefficients in a desired order in a one dimensional vector 114 . The quantized DCC is typically the first value of the vector 114 , and is represented differentially as the actual DCC value minus the DCC of the previous block as shown in block 116 . Vector 114 is encoded into a bit stream through a sequence of Run Length Counting (RLC) operations which count the number of zero ACCs that reside in the path before a non-zero ACC. These RLC operations are combined with Variable Length Codes (VLC) as indicated in block 118 which encode a symbol that includes a combination of the number of zeros preceding a non-zero ACC and the ACC amplitude. This encoding produces a compressed data stream which can be transmitted to receiving device 26 over communication lines.
FIG. 3 contains a detailed illustration of an 8×8 block of pixels 120 and the labeling configuration that will be used throughout the description of the present invention. It should be noted here that pixels 120 and pixel blocks 102 can be labeled in numerous other ways and it is not intended to imply that either JPEG compression or the present invention are limited to the ordering scheme shown here. Similarly, FIGS. 4 and 5 contain detailed illustrations of the unquantized and quantized DCT coefficients respectively that correspond to the 8×8 block 102 of pixels 120 illustrated in FIG. 3 . Again, neither standard JPEG compression or the present invention are limited to these embodiments.
FIG. 6 contains a detailed illustration of one pattern 112 in which the quantized DCT coefficients may be selected for placement into one dimensional vector 114 . As those skilled in the at will recognize, the illustration shown in FIG. 6 merely shows one of many possible zigzag coefficient selection patterns 112 that may be followed in order to practice the present invention.
Referring now to FIG. 7, generally speaking the present invention includes performing a portion of the JPEG compression method on a reduced set of data, without producing a substantial loss in the quality of the output image. The invention takes advantage of the fact that a 4-point DCT can be performed more quickly than an 8-point DCT can. As is well known in the art, JPEG achieves compression because most DCT coefficients in a block after quantization are zero. The present invention saves time by not computing zero coefficients. It is also known that a certain amount of high frequency loss can be tolerated particularly with color separation data or in a fax environment. The invention identifies and examines high band pass information for activity. Low activity blocks below a threshold as identified by the invention need not have a DCT coefficient calculated. Instead a zero value is substituted. This also allows the invention to save computation time.
In FIG. 7 as with the standard JPEG method described above, the scanned image is separated into blocks 701 of pixels 120 which indicate the intensity of the light at the various locations of the image. As before, an 8×8 block of pixels has shown to be very successful when used with the present invention. However, other pixel block dimensions are possible and the invention is not limited to this embodiment. Those skilled in the art will recognize that a smaller or larger block size might be chosen when it is desired to preserve more or less image detail. In fact it should be noted that while the horizontal and vertical dimensions are identical in the embodiment of pixel block 701 described here, this is not a requirement for practicing the present invention. For example, a non-square block might be chosen if the is image was generated for a device possessing asymmetric resolutions in the vertical and horizontal directions.
Once a pixel block 701 having the appropriate size and dimensions is chosen, block 701 must be segmented into sub-blocks 700 as indicated in FIG. 7 . In a preferred embodiment, an 8×8 block of pixels is used to practice the invention, segmenting pixel block 701 into 4 sub-blocks 700 , where each sub-block 700 is an array having four pixels 120 in the horizontal direction and four pixels 120 in the vertical direction. Those of ordinary skill in the art will recognize that if the user of the invention wishes to sacrifice some image reproduction accuracy in order to save costs, other array sizes might be used. If the user wishes to obtain higher image reproduction accuracy in some areas of the image, but requires less accuracy in other areas, a fine grid could be applied to some areas with a larger grid applied to other areas. Again, it is intended to embrace all such alternatives, and the invention is not limited to the examples provided here.
With continued reference to FIG. 7, each of the above described sub-blocks 700 shown in block 701 are labeled in block 702 . Each illustrated sub-block 700 is now represented as B 00 , B 01 , B 10 , and B 11 in block 702 . In a preferred embodiment a Haar transform 703 is performed upon the data in block 702 . A Haar transform is a technique well understood in the art as performing a matrix sum and difference operation. The Haar transform provides quadrant results A 00 , A 01 , A 10 , A 11 in the 8×8 quadrant blocks 704 , 705 , 706 , and 707 , respectively. Using the 4×4 Haar transform operation here separates out low pass band and high pass band components for subsequent operation.
In quadrant block 704 the A 00 result provides the low pass band information. Because low pass band information is essential for successful reconstruction of an image, the A 00 result is subsequently transformed by a 4-point DCT operation 708 . The A 01 , A 10 , A 11 quadrant results constitute higher frequency or high pass band information. Therefore, for quadrant results A 01 , A 10 , A 11 as found in quadrant blocks 709 , 710 , and 711 respectively, a comparison is made to a threshold value T 01 , T 10 , T 11 respectively. The comparison of the quadrant results to a threshold is provided for in decision blocks 709 , 710 , and 711 . Threshold table 802 as found in FIG. 8 and described below, is utilized for supplying the threshold values used in the decision blocks 709 , 710 , and 711 . If a given high pass band quadrant result is found to be above a particular threshold value, it is deemed as having enough information to warrant 4-point DCT transformation at DCT-4 block 712 , 713 and 714 respectively. However, as will often happen in a preferred embodiment, when a high pass quadrant result is found to be below the threshold value, that result is small enough to discard. In that event a zero is substituted as shown in FIG. 7 by the “Set to zero” blocks 715 , 716 and 717 . This provides the advantage of saving the 4-point DCT computational time which in a preferred embodiment constitutes picture detail information which is of little or even no consequence for a given targeted receiving device 26 .
The 4-point DCT must be scaled so that when C 00 , C 01 , C 10 , and C 11 are combined in approximation block 718 , the coefficients are compatible with the coefficients which would be obtained from an 8-point DCT. Therefore, the 4-point DCT is defined as: DCT4 ( U ) ≡ 1 2 D 4 UD 4 T .
Where D 4 is a 4×4 matrix with the following entries: d ij = k i cos ( i ( 2 j + 1 ) 8 π )
where k 0 =½, and
k i>0 =1 /sqrt (2).
With the completion of the 4-point DCT and the assembly of C 00 , C 01 , C 10 and C 11 into approximation block 718 , quantization of the data is now performed at block 108 utilizing a quantization table.
Provided in FIG. 8 is a preferred embodiment quantization table 800 . As will be well understood by those skilled in the art, this table 800 is but one of many possibilities. It is provided as an example, and as an aid for the explanation of the origin of a preferred embodiment threshold table 802 . The values found in threshold table 802 may be developed in many ways. However, for a preferred embodiment threshold table 802 is derived from quantization table 800 . To do this an average of the values by quadrant in the quantization table 800 is made to arrive at the values found in the threshold table 802 . Because there is no comparison made for A 00 , an “X” is shown as the value for that quadrant. The values shown “44”, “44”, and “108” are the thresholds for comparison to A 01 , A 10 , and A 11 respectively, and as stated above are averages from quantization table 800 .
Returning to FIG. 7, the remainder of the data processing as described above, is conventional as typified in a JPEG system. As indicated in step 112 a “zigzag” is followed through the 8×8 block of quantized coefficients resulting from step 108 to place the coefficients in a desired order in a one dimensional vector 114 . The quantized DCC is typically the first value of the vector 114 , and is represented differentially as the actual DCC value minus the DCC of the previous block as performed in block 116 . Vector 114 is encoded into a bit stream through a sequence of Run Length Counting (RLC) operations which count the number of zero ACCs that reside in the path before a non-zero ACC. These RLC operations are combined with Variable Length Codes (VLC) as indicated in block 118 which encode a symbol that includes a combination of the number of zeros preceding a non-zero ACC and the ACC amplitude. This encoding produces a compressed data stream which can be transmitted to receiving device 26 over communication lines.
To reiterate the basic steps involved in the invention using nomenclature designations in accord with FIG. 7 :
For a given 8×8-pixel block B.
The 4-point DCT is defined as DCT4 ( U ) ≡ 1 2 D 4 UD 4 T .
And D 4 is a 4×4 matrix with the following entries d ij = k i cos ( i ( 2 j + 1 ) 8 π )
where k 0 =½ and k i>0 =1/sqrt(2)
Divide B into 4 sub-blocks of 4×4 pixels each. As B = ( B 00 B 01 B 10 B 11 ) .
Create new blocks of samples (Haar transform) as:
A
00
=B
00
+B
01
+B
10
+B
11
A
01
=B
00
−B
01
+B
10
−B
11
A
10
=B
00
+B
01
−B
10
−B
11
A
11
=B
00
−B
01
−B
10
+B
11
And create yet another sub-block C 00 =DCT4(A 00 )
For given thresholds T 01 , T 10 , T 11 :
If any element in A 01 is greater than T 01 then make C 01 =DCT4(A 01 ), otherwise make C 01 =0.
If any element in A 10 is greater than T 10 then make C 10 =DCT4(A 10 ), otherwise make C 10 =0.
If any element in A 11 is greater than T 11 then make C 11 =DCT4(A 11 ), otherwise make C 11 =0.
Compose the matrix with the transformed samples as C = ( C 00 C 01 C 10 C 11 )
A preferred embodiment as described above utilizing Haar transformation and 4-point DCT is exemplary for the greater processing speed it realizes by reducing the total processing complexity. Counting addition's, multiplication's, compares (to zero), shifts, etc. as one operation (op), the total complexity for the 8×8 2D DCT is 768 ops assuming separable fast algorithms. Using the same algorithm for the 4×4 2D DCT the complexity is 112 ops. The total complexity for the proposed transform is 336+112n ops, where n is the number of active high-frequency bands (0,1,2,3), i.e. bands above the threshold. For a given image, the average complexity per block is 336+112 {overscore (n)} , where {overscore (n)} is the average value of n. Compared to the full DCT, the relative complexity is C({overscore (n)})=0.4375+0.1458{overscore (n)}, therefore:
0.437 ≦C ( {overscore (n)} )≦0.875
In other words, in the best case the complexity is less than half of that of the DCT and in the worst case it is at least 12.5% less that the DCT.
While the application of a preferred embodiment to a JPEG compression framework will yield faster processing, it is not identical to the implementation used in the JPEG standard and thus there is some small loss of detail information. This loss in a color facsimile system is of small consequence in budget situations and the compression ratio achieved is very similar to the one achieved by using a regular DCT. However, there are actually two options on the decompression side. First, if the decoder is a standard JPEG decoder, it may not know how to use the proposed transform. The image in that situation is still decompressed but of course using the regular JPEG 8-point DCT. For high compression ratios there is virtually no loss of quality. As the compression ratio decreases, small ringing (jagged) artifacts may appear near sharp edges. These artifacts are light in intensity and may or may not be noticeable in a printing environment. In a cost benefit analysis this has been determined to be an acceptable trade-off for the increased processing speed. In the preferred alternative, it is conveyed to the receiver information that such a transform, as described in the present invention has been used. A smart de-compressor is therein provided which is will then use the inverse transform of the present invention (inverse 4×4 DCTs and inverse Haar). The image quality and compression ratios in this case are then about the same as those obtained by using a regular DCT-JPEG.
It is, therefore, apparent that there has been provided in accordance with the present invention, a method and apparatus for fast compression of JPEG files. While this invention has been described in conjunction with a specific embodiment thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims.
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A method for compressing digital image data to improve the efficiency of serial data transmission is disclosed. More specifically, the present invention accomplishes image compression by performing the most complex portions of a standard compression technique on a subset of the originally provided data utilizing a modified two-dimensional discrete cosine transform. The invention includes a fast JPEG compressor using a Haar transform with a conditional transform.
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