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TECHNICAL FIELD
The present invention relates to a calibration phantom or test object for simulating animal or human cell tissue which can calibrate, or test diagnostic ultrasound scanners.
BACKGROUND OF THE INVENTION
Ultrasonics has been used in the prior art for purposes of medical diagnosis. Specifically, ultrasonic pulses are transmitted into the body and tissue boundaries produce reflection of the pulses. The transit time of a transmitted and reflected pulse can be measured to provide a determination of the depth of such a boundary.
There is a considerable overlap in the diagnostic uses of ultrasound and computed tomography. Each modality produces cross-sectional images of soft tissue with high spatial resolution and excellent contrast sensitivity or tissue differentiation. However, the imaging mechanisms of the two modalities are entirely different. In computed tomography, an image is mathematically reconstructed utilizing a back-projection algorithm to produce a two-dimensional mapping of X-ray attenuation coefficient. The contrast sensitivity of computed tomography displays local changes in X-ray absorption coefficient of 0.5% of the absorption coefficient of water anywhere in the tomographic image. On the other hand, for diagnostic ultrasound, reflected or scattered mechanical energy is utilized to form images directly. Reflections occur due to the changes in acoustic impedance at every tissue interface. Generally speaking, acoustic impedance of material is the product of its density and the speed of the acoustic waves in the material. In soft tissue imaging, the impedance varies over a range of 60 dB. Even the small changes in the impedance parameter which are associated with soft tissue interfaces (as low as 1 part in a million) are easily detected, resulting in excellent contrast sensitivity.
For each of the computed tomography and ultrasound modalities, a feature of prime importance is the ability to detect lesions of varying size and contrast from the background tissue. For both modalities, the capability of displaying low contrast lesions in a tissue background is limited by two intrinsic imaging parameters, namely: the spartial resolution, and the image noise. These two aspects of image quality have been extensively analyzed and are readily predictable for computed tomography; however, there is very little knowledge concerning image quality characteristics for diagnostic ultrasound devices.
For both the computed tomography and diagnostic ultrasound modality, the limiting three-dimensional spatial resolution for high contrast objects can be described by either the point spread function (PSF) or its Fourier transform, the modulation transfer function (MTF). The analogous two-dimensional spatial resolution within a tomographic image of a given thickness is described by the line spread function (LSF) and its modulation transfer function. The spatial resolution for computed tomography scanners varies to a limited extent over the field of view. The spatial resolution of pulse echo diagnostic ultrasound differs in the axial versus the lateral image dimensions. In the axial dimension, the resolution is determined by the pulse length of the propagating ultrasound pulse. In the perpendicular lateral dimension, due to the wave nature of ultrasound radiation, the spatial resolution is diffraction-limited, depending on the ultrasound wavelength and the f number of a focused transducer. Therefore, for fixed focus ultrasound imaging systems, lateral resolution varies throughout the image field of view. In view of the variation of the spatial resolution with position for both computed tomography and ultrasound, measurements of LSF or MTF should be made at many points in the image and the results averaged to provide a two-dimensional description of spatial resolution.
Spatial resolution or LSF for both diagnostic ultrasound and computed tomography scanners has traditionally been measured by scanning high contrast wires or rods in a water medium. Spatial resolution for abdominal computed tomography systems is on the order of 1 mm square. For diagnostic ultrasound abdominal scanners, axial resolution is optimally about 2 mm and lateral resolution varies from 2 mm at the transducer focus to 1 cm near the transducer and in the far field. In the case of diagnostic ultrasound, high contrast spatial resolution can also be measured by imaging wires or rods suspended in an attenuating tissue equivalent material. Such tissue equivalent resolution phantoms are now commercially available, such as the Model 412 Tissue Phantom manufactured and sold by Radiation Measurements, Inc. of Middleton, Wis., and such as the device illustrated and described in U.S. Pat. No. 4,116,040. Measurements indicate that spatial resolution deteriorates significantly in a tissue medium, primarily due to the frequency-dependent attenuation of tissue and phase-aberration effects of intervening tissue.
The ability of a medical imaging modality to detect a low contrast lesion from a tissue background is limited by the noise in the image. For both computed tomography and diagnostic ultrasound, the noise can be described by the standard deviation of the fluctuation in image intensity from the mean background of an image of a standard uniform test object. Each of the described modalities is subject to electronic noise. Computed tomography also suffers from noise generated due to the algorithm in the mathematical image reconstruction; however, the main noise sources for the two imaging modalities are distinctly different. In computed tomography, as in all radiographic imaging, the primary noise source is quantum mottle, or fluctuations in image background directly related to the photon statistics of image formation. The greater the radiation dose, the less the image noise. In diagnostic ultrasound, the primary noise source is not a function of exposure statistics, but rather is due to coherent speckle, a phenomenon common to all coherent imaging (for example, laser optics). In scanning an abdominal organ, large numbers of scatterers are present in the tissue. Interference effect in the echoes from the multiple scatterers cause severe fluctuations in the image background level which obscure important diagnostic signals.
Due to the restrictions of spatial resolution and image noise for diagnostic ultrasound and computed tomography, low contrast detectability of these modalities is limited. The low contrast performance of these systems can be measured directly using suitable phantoms in the form of objects of varying size and contrast embedded in a tissue-equivalent medium. Several "contrast detail" phantoms have been developed and evaluated for computed tomography applications. An extensive investigation of computed tomography contrast-detail-dose interdependency is described in an article by Cohen, et al., entitled "The Use of a Contrast-Detail-Dose Evaluation of Image Quality in a Computed Tomographic Scanner" appearing in the Journal of Computer Assisted Tomography, Volume 3, pages 189-195, 1979. This paper describes the utilization of the partial volume effect in radiography whereby a phantom was developed containing cylindrical objects varying in contrast from 0.2% to 3% over a range of diameters from 16 mm down to 1 mm. Utilizing this phantom, the threshold of perceptibility of patterns of disks was measured utilizing multiple observers for several computed tomography scanners and dose values. The results for computed tomography indicated the contrast-detail-dose relationship could be divided into (1) a high contrast region (10%-100%) wherein the detection capability was strongly dependent upon the system spatial resolution (MTF) and weakly dependent upon noise (dose) and contrast; (2) a transition contrast region (1%-10%) wherein lesion detectability was dependent upon contrast, noise (dose) and MTF; and (3) a low contrast region (0.1%-1%) wherein the detection was strongly dependent upon image noise, that is, dose. Therefore, for low contrast lesions, image noise becomes the limiting characteristic for detection in computed tomography.
In the field of diagnostic ultrasound, only rudimentary efforts have been made to study the detection capability of low contrast targets. Tissue-equivalent phantoms containing simulated cysts are commercially available and another phantom is marketed containing cylindrical objects whose reflectivity varies from background tissue by 1 dB and 10 dB. These phantoms utilize tissue-equivalent materials of water-based gelatins. Oil-based gels have also been utilized to construct an anthropomorphic ultrasound phantom. However, there has been no attempt to include low contrast objects suitable for quantitative measurements of low contrast detectability of an ultrasound scanner. In each of the prior art phantoms, the variation in contrast or reflectivity is obtained by varying the concentration and particle size of scatterers in the gel matrix of the artificial tissue. For the oil-based gel, polyvinylchloride particle sizes ranging from 100 microns to 260 microns, with concentrations of 0.3 particles per cubic millimeter to 2.0 particles per cubic millimeter demonstrated a reflectivity range from -25 dB to +5 dB relative to the reflectivity of liver.
Thus, where prior art test objects and phantoms enable the evaluation of high contrast resolution in water or tissue-equivalent media, the true efficacy of ultrasound scanners depends upon the ability of such scanners to detect low contrast lesions in tissue. Prior art phantoms simply do not have this low contrast measurement capability. Clearly, then, there is a need for a tissue-equivalent ultrasound phantom capable of permitting measurement of the relationship between threshold detection of lesions of varying size versus contrast (reflectivity).
SUMMARY OF THE INVENTION
It is therefore a primary object of the present invention to provide a contrast resolution tissue-equivalent ultrasound phantom for diagnostic ultrasound scanners which will enable the measurement of the relationship between threshold detection of lesions of varying size versus image contrast or reflectivity in a tissue-equivalent medium.
It is another object of the present invention to provide a contrast resolution tissue-equivalent ultrasound phantom which is compact, inexpensive to manufacture and easily utilized by clincal personnel.
In accordance with the present invention, a contrast resolution tissue-equivalent test phantom is provided in the form of a block of tissue-equivalent material. The material may be a water-based or oil-based gelatin which contains suspended acoustic scattering particles having acoustic scattering properties similar to living tissue. A plurality of cavities are defined in the block and are filled with tissue-equivalent material having respectively different acoustic scattering properties. The cavities are configured to present similar sized cross-sections to the ultrasonic scanner for each cross-sectional scan. The dimensions of the cavities vary transversely to the scan plane so that successively smaller (or larger) cross-sectional images are presented with each succeeding scan.
In the preferred embodiment, the cavities are conical in shape. The reflectivity of the material in the respective cavities varies in steps over a 30-60 dB range in the preferred embodiment. Cross-sectional scans, perpendicular to the lengths of the conical cavities, at various positions along the lengths of the cavities result in images of disks of a constant diameter but varying contrasts. The scans permit observation of the resolution capability of the ultrasonic scanner for the varying contrasts (reflectivities) of the cavities for different size cross-sections.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings will be more clearly understood when taken in conjunction with the following description, wherein:
FIG. 1 is a view in perspective of a test phantom constructed in accordance with the principles of the present invention;
FIG. 2 is a view in perspective of an alternative embodiment of the test phantom constructed in accordance with the principles of the present invention; and
FIG. 3 is a view in perspective illustrating a test phantom according to the present invention utilized in conjunction with an ultrasonic scanner.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring specifically to FIG. 1 of the accompanying drawings, a block 10 of tissue-equivalent material is shown as being fully transparent to facilitate understanding; it is understood however that the tissue material need not be, and in most instances will not be, transparent. Further, the block 10 is shown as a right angle parallellepiped having front surface 11, rear surface 12, side surfaces 13 and 14, top surface 15 and bottom surface 16. This configuration is for convenience in fabrication but is by no means limiting on the scope of the invention. The tissue-equivalent material is preferably a gel and is selected to have a density and an ultrasound propagation velocity which simulates those of human or animal tissue. In addition, acoustic scatterers are interspersed homogeneously throughout the gel to further simulate desired tissue. For example, the gel could be a water-based gel such as agar in which particles of graphite, polyvinylchloride, glass micro-balloons, or the like are interspersed homogeneously as scatterers. Likewise, an oil-based gel can be employed with similar scatterer particles. Oil-based gels are well known and a variety of such gels can be employed for this application. A particularly suitable oil-based gel can be made from Kraton, a styrene-butadiene resin sold by Shell Oil Company, mixed with mineral oil absorbed in butadiene chains; the mixture is gelled by heating to 130° C. for 1-half hour. This gel is described in greater detail in the final report "Development of an Ultrasound Phantom" dated Jan. 25, 1979 submitted under U.S. FDA Contract No. 233-77-6017. Such material closely simulates liver parenchymal tissue in acoustic imaging.
A series of conical contrast objects 21-28, inclusive, are embedded in block 10 with their axes oriented mutually parallel and coplanar in a plane parallel to top surface 15 and bottom surface 16 of block 10. The cones are substantially identical in size, decreasing in diameter in the direction from front surface 11 to rear surface 12 of block 10. Contrast objects 21-28 are formed by inserting correspondingly shaped molds in block 10 before the gel is formed and then removing the molds after gelling to provide conical cavities. The cavities are then filled with tissue-equivalent material which is allowed to gel. Contrast objects 21-28 are preferably made of the same gel material as block 10 but each has a different acoustic scattering property so that net effect is that the contrast objects are each of different tissue-equivalent material and of different tissue-equivalent material from block 10. Variation of acoustic scattering properties between contrast objects 21-28 can be achieved by changing the density of scatterer particles in each contrast object, using different size scatterer particles in each object, etc. Typically, the acoustic scattering in contrast objects 21-28 is varied to achieve a reflectivity variation on the order of 30 dB. One contrast object, for example, object 21, has substantially cyst-like reflectivity properties, so that objects 22-28 preferably have reflectivities which vary in 3.75 dB steps to provide an overall range of 26.25 dB, this being typical of the dynamic range of soft tissue echoes. If reflectivity variation is achieved by means of changing scatterer particle size, spherical particles may be utilized having diameters over a range of ten to four hundred microns.
In an embodiment which has been constructed and found to operate satisfactorily, contrast objects 21-28 are located at a depth of approximately 7.5 cm below top surface 15 in order to simulate the depth of typical abdominal organs. The angle subtended by the conical contrast objects is chosen so that the variation in diameter of the cone across the beam width of an ultrasonic transducer is small. For example, for a transducer beam width of 13 mm, the diameter of the cross-section of the cone should vary by only 1.3 mm over a 13 mm length. Therefore, the cone angle would be approximately 5.6°. In order to obtain image disk diameters from 0 to 2 cm, a total cone length of 20 cm would be required. Consistent with these dimensions, the length of top surface 15 and bottom surface 16 would typically be 25 cm; the height of the block is typically 12 cm. The depth of the block depends upon the desired length of conical contrast objects 21-28 but in a typical embodiment, is 12 cm, the cones for such embodiment being 10 cm long. The bases of the cones are 2 cm in diameter and are spaced apart by 1 cm. These dimensions are, of course, by way of example only, and are not deemed limiting on the scope of the present invention.
The phantom illustrated in FIG. 1 is shown in use in the schematic diagram of FIG. 3. An ultrasound scanner is shown to include a console 31 and transducer 32 interconnected by cable 33. A typical scanner which serves the purpose described in relation to the present invention is the Model 2130 manufactured by ADR Ultrasound of Tempe, Ariz. Transducer 32 transmits an ultrasonic pulse beam in a plane defined by the length dimension of the transducer. Reflections of the beam energy are received by the transducer and transmitted back to the console 31 via cable 33 and displayed on console oscilloscope 34. As illustrated in FIG. 3, transducer 32 is oriented in the width dimension of block 10 so that the beam strikes the same size diameter portion of each contrast target 21-28. This cross-sectional scan of each contrast target results in an image on oscilloscope 34 of eight generally circular disks having varying reflectivities depending upon the scattering properties of each contrast object. A series of scans are made at different locations along top surface 15 of block 10 as indicated by the arrows in FIG. 3. Thus, successive scans are made perpendicular to the length of the contrast objects at various positions along the cone length. The diameter of the eight image disks in any scan will be the same, but will change from scan to scan as the transducer is moved. The contrast or reflectivity of the eight disks in any given scan varies in accordance with the reflectivity or scattering properties of the contrast objects. If desired, the diameter of threshold detection for lesions of varying contrasts can be utilized to construct curves of contrast versus diameter. The various scans permit measurement of the relationship between threshold detection of lesions varying in size versus image contrast or reflectivity in the tissue-equivalent medium.
Another embodiment of the test phantom is illustrated in FIG. 2 wherein like elements are designated by like reference numerals. Specifically, a block 30 of tissue-equivalent material, identical to block 10 of FIG. 1, includes contrast objects 31-38 which, instead of being conical in shape, are configured as plural cylinders of decreasing diameter. Contrast objects 31-38 are constructed in the same manner described above in relation to contrast objects 21-28 and have acoustic scattering properties which are made to vary in the same manner as that described in relation to FIG. 1. Successive scans of block 30 are made at corresponding cylinder diameters. The test phantom of FIG. 2 is otherwise identical to that described above in relation to FIG. 1.
It should be noted that the specific location and number of contrast objects described above is not limiting on the scope of the present invention. For example, instead of eight contrast objects for producing eight simultaneous disk images, as few as two contrast objects, each having a different reflectivity, may be employed to provide a meaningful comparison of contrast for successive scans at different object diameters. Likewise, the maximum number of test targets is limited only by the practicalities of size and meaningful test results for a given application. The shape of the contrast object need not be conical or discretely stepped cylinders as described, but instead may take any shape in which the cross-section in the plane of the ultrasound scanning beam changes to simulate lesions of different size with each scan. For example, a pyramid or any other generally converging shape may be employed. Likewise, the cone or pyramid may be truncated, if desired. Of further note is the fact that the contrast objects, while preferably disposed in a plane parallel to the top surface of the block, may be positioned at different heights in the block for certain applications of the phantom. In any variation from the specific embodiments described herein, the important point to consider is that the contrast objects must provide varying contrasts and changing dimensions so that each individual scan yields a plurality of images of different contrasts whereas successive scans yield images of different size.
The present invention is not to be limited to the exact details of construction as shown and described herein, for obvious modifications can be made by a person skilled in the art. | A contrast resolution tissue-equivalent ultrasound test phantom comprises a block of material having ultrasonic propagation characteristics similar to that of human or animal tissue. A plurality of contrast objects are embedded in the block, each having a different reflectivity. The contrast objects have at least one dimension wherein the size of the object in cross-section decreases so that periodic ultrasonic scans of all of the objects simultaneously produce successive displays of plural cross-sectional patterns, the pattern in each display having the same size but different contrasts whereas the pattern size changes for successive displays. | 6 |
The present invention relates to a process for deasphalting a heavy hydrocarbon feedstock.
A heavy hydrocarbon feedstock within the meaning of the present invention is a feedstock having a density at 15° C. greater than about 930 kg/m 3 and composed essentially of hydrocarbons but containing also other chemical compounds which have, in addition to carbon and hydrogen atoms, heteroatoms such as oxygen, nitrogen and sulfur, and metals such as vanadium or nickel.
This feedstock may consist, in particular, of a crude petroleum or of a heavy oil having the aforesaid density.
The feedstock may also come from the fractionation or treatment of crude petroleum, of a heavy oil, of oil shales or even of coal. Thus it may be the residuum from vacuum distillation or the residuum from atmospheric distillation of the starting products cited above or, for example, products obtained by the thermal treatment of these starting products or their distillation residua.
BACKGROUND OF THE INVENTION
The trend in recent years has been to seek to upgrade high-density hydrocarbonaceous products more and more, which was not the case before. The need to upgrade heavy products has become more pressing since it is anticipated that the demand for light products such as motor fuels will increase at a relatively faster pace than the demand for heavier products, such as fuel oils.
The heaviest portion of heavy hydrocarbon feedstocks consists of a mixture of an oil phase and an asphaltic phase.
The asphaltic phase is the phase which precipitates upon the addition of a hydrocarbon with a low boiling point (for example, propane, butane, pentane, hexane, or heptane), the oil phase being soluble in said hydrocarbon.
The oil phase, that is, the light phase, is economically more worthwhile than the asphaltic phase. It fact, it may be used as a catalytic cracking feedstock that will yield light products. It may also serve as a feedstock for the production of lubricating-oil bases. These products are more valuable than the fuels and bitumens obtained from the asphaltic phase.
As has been pointed out above, heavy hydrocarbon feedstocks contain compounds which have, in addition to hydrogen and carbon atoms, heteroatoms such as oxygen, nitrogen and sulfur as well as metals. Some of these compounds, and particularly those containing metals, are present especially in the asphaltic phase.
Two groups are customarily distinguished among the compounds which make up the asphaltic phase: the resins and the asphaltenes. Both the asphaltenes and the resins have polycyclic aromatic structures. Apart from aromatic rings, thiophene and pyridine rings are present. However, the resins have less-condensed structures than the asphaltenes and lower molecular weights.
The name "asphaltenes" is generally applied to compounds which are precipitated by the addition to the feedstock of a saturated aliphatic hydrocarbon having from 5 to 7 carbon atoms, such as pentane, hexane, or heptane. Under French standard AFNOR NFT 60-115, the asphaltene content of a product thus is determined by precipitation with normal heptane upon boiling.
The resins precipitate at the same time as the asphaltenes when a hydrocarbon with a lower boiling point, for example, propane, is used. In fact, this is a conventional differentiation, and it is obvious that when a given hydrocarbon is employed at a given temperature to treat a feedstock, precipitation of asphaltene-type compounds can be obtained if the hydrocarbon and the temperature are appropriate. If the feedstock freed from the asphaltenes is then treated with the same hydrocarbon at a higher temperature, precipitation of the resins is obtained.
In the well-known deasphalting process, the oil phase and the asphaltic phase are separated by an operation which consists in extracting the oil phase from a hydrocarbon feedstock by means of a substance known to those skilled in the art as a solvent. The solvent is both a solvent for the oil phase and a precipitant for the asphaltic phase. Hereinafter it will be referred to simply as a solvent.
The solvent may be selected from the group consisting of:
saturated or unsaturated aliphatic hydrocarbons having from 2 to 8 carbon atoms, alone or in admixture;
mixtures of hydrocarbons, known as distillates, with molecular weights close to those of the hydrocarbons having from 2 to 8 carbon atoms; and
mixtures of all of the aforesaid hydrocarbons.
Deasphalting may be carried out in a single stage, in which case an oil phase and an asphaltic phase are obtained, the latter containing both the asphaltenes and the resins. It may also be carried out in two stages, using two different solvents and/or different operating conditions in the two stages. In the two-stage process, the oil phase, the resins and the asphaltenes are obtained separately. (See, for example, French patent application No. 86 06994, filed on May 15, 1986, in the name of the Applicant; and correspond-U.S. patent application Ser. No. 050,912 filed May 15, 1987).
As mentioned above, it is the oil phase that is more worthwhile economically. In a deasphalting process, whether single- or two-stage, it is therefore advisable to endeavor to obtain a maximum yield of the oil phase. Of course, this striving for a maximum oil-phase yield should not be at the expense of the characteristics of the oil phase.
BRIEF SUMMARY OF THE INVENTION
The present invention thus is directed to increasing in a deasphalting process the yield of the oil phase while preserving the characteristics of the oil phase which are desirable for the contemplated use. For example, for its use as a catalytic cracking feedstock, a Conradson residue (determined in conformity with standard AFNOR NFT 60-116) of less than 10 weight percent is desirable.
To this end, the invention has as a preferred embodiment a process for deasphalting a heavy hydrocarbon feedstock by means of a solvent, said process being characterized in that the feedstock is subjected to shearing, optionally before and/or after the addition of at least a portion of the solvent.
For the purposes of the present invention, shearing means the application of high stress to the diluted or undiluted feedstock.
The shearing action may be produced in particular by the forced passage of the feedstock, which optionally contains at least a portion of the solvent, through a restriction, a convergent die, a gap between two parts, one of which is moving relative to the other, a pipe of smaller cross-sectional area than the feed pipe for the feedstock, or any equivalent contrivance.
The shearing action may also be produced by the use of a turbine or of any other agitating means, optionally in the deasphalting tower.
In the case of the passage of the feedstock through a gap bounded by a stationary part and a coaxial part rotating within the stationary part, the shearing action expressed as a rate is given by the ratio du/dx, where du is the velocity difference between the walls of the gap, and dx the distance separating the parts bounding the gap. This shearing may then be at a rate ranging from 10 3 to 10 6 s -1 and preferably ranges from 10 4 to 2·10 5 s -1 , where s is time in seconds.
The result of the shearing action is surprising since one skilled in the art would be inclined to think that shear would cause the asphaltenes to be dispersed rather than precipitated. It is well known, for example, that to obtain an emulsion of fine water droplets in an oil it is advisable to agitate the oil/water mixture vigorously, in other words, to produce strong shearing action.
The deasphalting operation which follows shearing or is concurrent with it may be carried out in one or two stages.
In the former case, an oil phase and an asphaltic phase are obtained, and in the latter case, an oil phase, a resin phase and an asphaltene phase.
The solvent used in the extraction stage or stages may be selected from the group consisting of
saturated or unsaturated aliphatic hydrocarbons having from 2 to 8 carbon atoms, alone or in admixture;
mixtures of hydrocarbons, known as distillates, with molecular weights close to those of the hydrocarbons having from 2 to 8 carbon atoms;
mixtures of all of the aforesaid hydrocarbons; and
other chemical compounds which have, in addition to carbon and hydrogen atoms, heteroatoms such as oxygen, for example, alcohols and phenols, alone or in admixture with the aforesaid hydrocarbons.
The operating conditions in the deasphalting stages may be as follows:
Pressure ranging from 20·10 5 to 1·10 7 pascals abs.
Temperature ranging from 30° to 300° C.
Mass ratio of solvent to feedstock ranging from 1 to 10.
These conditions will vary, of course, depending in particular on the nature of the feedstock and on the nature of the solvents used.
A better understanding of the invention will be provided by the detailed description which follows, with reference to the accompanying drawing, which is nonlimitative.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 diagrammatically shows as a preferred embodiment a deasphalting unit including a shearing installation.
DETAILED DESCRIPTION
In this embodiment of the invention, the heavy hydrocarbon feedstock to be deasphalted, for example, an oil having a density at 15° C. greater than 930 kg/m 3 , is introduced through line 1 into the midsection of a liquid-liquid extractor 2.
In the extractor 2, the oil phase is extracted from the feedstock by means of a solvent introduced into the extractor through line 3. The solvent may be, in particular, a saturated or unsaturated aliphatic hydrocarbon having from 2 to 8 carbon atoms, and preferably from 3 to 5 carbon atoms, or mixtures of hydrocarbons, known as distillates, having from 2 to 8 carbon atoms, or mixtures of all of the aforesaid hydrocarbons.
The starting solvent of the unit comes from a source external to the unit through line 4. The solvent losses may be compensated by means of an external makeup supplied through line 4.
The pressure in the interior of the extractor 2 may range from 20·10 5 to 1·10 7 pascals abs, the temperature from 30° to 300° C., and the mass ratio of solvent to feedstock from 1 to 10.
At the top of the extractor 2, through line 5, the oil phase in solution in the solvent is recovered. This mixture is piped through line 5 to a fractionating section 6. For simplicity, this section is not shown in detail, but it generally comprises a regulator controlling a pressure drop, as well as evaporators.
At the outlet of section 6, solvent is recovered through line 7 and recycled to the extractor 2 through line 3, and the oil phase is withdrawn through line 8.
At the bottom of the extractor 2, the precipitated asphaltic phase as well as solvent are withdrawn. This mixture is conducted through line 10 to a fractionating section 11, which generally comprises a furnace or an exchanger with a hot fluid, an evaporator, and a steam stripping column.
At the outlet of section 11, solvent is recovered through line 12 and recycled to the extractor 2 through line 3, and the asphaltic phase is withdrawn through line 13.
A portion of the solvent from line 3 may be piped to line 1 through line 14 to predilute the feedstock, if desired.
In accordance with the invention, at least one restriction may be located at 20 in line 1 to induce shear in the feedstock. (There might be several such restrictions in parallel, depending on the flow rate of the feedstock.) This restriction could also be located downstream or upstream of the intersection of lines 1 and 14, ahead of the deasphalting tower 2.
In addition to or in place of the device 20, an agitating means such as a turbine may be provided in tower 2.
The examples which follow will illustrate how the invention is carried out as well as its advantages.
EXAMPLE 1
This example relates to deasphalting tests run with a vacuum-distillation residuum of the atmospheric-distillation residuum of a Safaniya crude petroleum with and without prior shearing of the residuum.
The characteristics of this charge stock are as follows:
______________________________________Density at 15° C.: 1042 kg/m.sup.3(Determined in conformity with standard AFNORNFT 60-101)Viscosity at 100° C.: 6250 mm.sup.2 /s(Determined in conformity with standard AFNORNFT 60-200)Conradson residue: 22.9 wt. %(Determined in conformity with standard AFNORNFT 60-116)Asphaltene content: 15.1 wt. %(Determined in conformity with standard AFNORNFT 60-115)Sulfur content: 5.46 wt. %(Determined by x-ray fluorescence)Nickel content: 45 ppm(Determined by x-ray fluorescence)Vanadium content: 149 ppm(Determined by x-ray fluorescence)______________________________________
This feedstock is subjected to:
deasphalting control tests T1 and T2 without prior shearing of the charge stock, and
tests A11, A12 and A2 in accordance with the invention after prior shearing of the feedstock and without prior solvent addition.
The deasphalting solvent used in all tests is a solvent having the following composition (in percent by volume):
______________________________________ Propane 0.82 Isobutane 43.99 n-Butane 23.01 n-Butene-1 8.08 Isobutene 9.17 cis-Butene-2 9.16 trans-Butene-2 5.70 Isopentane 0.07______________________________________
The conditions of the tests are given in Table 1 which follows.
TABLE 1______________________________________Temper- Pressure Mass ratioature 10.sup.5 pas- solvent toTest °C. cals abs feedstock Nature of prior shearing______________________________________T1 70 40 4 No shearingA11 70 40 4 Machine: Emulsifier. Gap: 1 mm. Speed of rotation: 7000 rpm. Temperature: 150° C. Recycling time: 2 min- utes.A12 70 40 4 Machine: Emulsifier. Gap: 1 mm. Speed of rotation: 7000 rpm. Temperature: 150° C. No recycling. Single pass. Very short time.T2 70 40 6 No shearing.A2 70 40 6 Machine: Emulsifier. Gap: 0.35 mm. Speed of rotation: 7000 rpm. Temperature: 130° C. Recycling time: 10 min- utes.______________________________________
At the end of these tests and after separation of the solvent, an oil phase and an asphaltic phase are obtained. The yields obtained and the characteristics of these phases are determined. They are presented in Table 2 which follows.
TABLE 2__________________________________________________________________________ T1 A11 A12 Oil Asphaltic Oil Asphaltic Oil AsphalticTest phase phase phase phase phase phase__________________________________________________________________________Yield, wt. % 46.2 53.8 49.6 50.4 50 50Density at 15° C., kg/m.sup.3 (1) 967.3 966.7 965.2Index of refraction at 60° C. 1.5290 1.5296 1.5288Softening point, °C. (3) 122.5 119 122Viscosity at 100° C., mm.sup.2 /s (4) 108.9 111.7 100.7Conradson residue, wt. % (5) 6.4 37.5 6.05 37.1 6.6 36Asphaltene content, wt. % (6) 0.05 31.6 0.05 29.6 0.08 34.5Sulfur content, wt. % (7) 3.71 7.58 3.70 6.54 3.75 7.14Nickel content, ppm (7) 4 92 3 93 3 87Vanadium content, ppm (7) 6 296 8 260 7 269__________________________________________________________________________ T2 A2 Oil Asphaltic Oil Asphaltic Test phase phase phase phase__________________________________________________________________________ Yield, wt. % 62.5 37.5 66.6 33.4 Density at 15° C., kg/m.sup.3 (1) 969.6 968.5 Index of refraction at 60° C. 1.5305 1.5299 Softening point, °C. (3) Viscosity at 100° C., mm.sup.2 /s (4) 121.3 114.5 Conradson residue, wt. % (5) 6.7 37.4 6.6 36 Asphaltene content, wt. % (6) 0.045 32.3 0.13 31.7 Sulfur content, wt. % (7) 3.76 7.15 3.82 6.76 Nickel content, ppm (7) 3 90 3 98 Vanadium content, ppm (7) 6 285 7 271__________________________________________________________________________ (1) In conformity with standard AFNOR NFT 60-101 (3) In conformity with standard AFNOR NFT 66-008 (4) In conformity with standard AFNOR NFT 60-100 (5) In conformity with standard AFNOR NFT 60-116 (6) In conformity with standard AFNOR NFT 60-115 (7) Determined by xray fluorescene
In discussing Example 1 (including Tables 1 and 2), the published French priority application (No. 86.11638 filed Aug. 12, 1986 and from which priority was claimed in the original application papers in this case) made the following observations:
From these results, it can be seen that with identical operating conditions, better yields of oil of a substantially similar quality are obtained by the process of the invention.
For example, if one compares tests T2 and A2, the oil yield increases from 62.5% to 66.6%, which means an increase of 4.1%. It can be seen, also, that the quality of the resulting oil is almost identical for the two tests:
Conradson residue (wt %): 6.5 and 6.6,
Viscosity at 100° C. (mm 2 /s): 119.3 [sic., actually 121.3 in Table 2] and 114.5.
It should also be noted that the advantageous effect of the shearing subsists even if the deasphalting step is not conducted immediately after the shearing step.
EXAMPLE 2
This example relates to deasphalting tests run with two feedstocks C 1 and C 2 , with and without prior shearing of the feedstocks. When it is effected, shearing takes place in the presence of solvent.
Feedstock C 1 identical to that used in Example 1 and therefore consists of a vacuum-distillation residuum of an atmospheric-distillation residuum of a Safaniya crude petroleum. Its characteristics are given in Example 1. Feedstock C 2 consists of an atmospheric-distillation residuum of a Maya crude petroleum.
The characteristics of this feedstock are as follows:
______________________________________Density at 15° C.: 1026 kg/m.sup.3(Determined in conformity with standard AFNORNFT 60-101)Viscosity at 100° C.: 876 mm.sup.2 /s(Determined in conformity with standard AFNORNFT 60-100)Conradson residue: 19.7 wt. %(Determined in conformity with standard AFNORNFT 60-116)Asphaltene content: 16.2 wt. %(Determined in conformity with standard AFNORNFT 60-115)Sulfur content: 4.57 wt. %(Determined by x-ray fluorescence)Nickel content: 91 ppm(Determined by x-ray fluorescence)Vanadium content: 480 ppm(Determined by x-ray fluorescence)______________________________________
These feedstocks are subjected to:
deasphalting control tests T 3 (with C 1 ) and T 4 (with C 2 ) without prior shearing of the feedstock, and
tests A 3 (with C 1 ) and A 4 (with C 2 ) in accordance with the process of the invention after prior shearing of the feedstock, with addition of solvent prior to shearing.
The addition of solvent, n-heptane, is made with agitation at a temperature 10° C. higher than the softening temperature of the feedstock: 60° C. for C 1 , and 34° C. for C 2 (determined in conformity with standard AFNOR NFT 66-008).
Shearing is effected at a temperature of 95° C. in a turbine having a gap of 0.6 mm and a notched head (with the teeth spaced 2 mm apart) at a speed of rotation of 17,000 rpm.
For the tests T 3 and A 3 , a solvent composed of 89 weight percent n-pentane and 11 weight percent n-heptane is used.
For the tests T 4 and A 4 , the solvent contains 78.1 weight percent n-pentane and 21.9 weight percent n-heptane.
In these compositions, allowance is made for the n-heptane previously added.
The conditions of the tests are given in Table 3 below.
TABLE 3______________________________________ Mass ratio Temperature, Pressure, solvent toTest °C. pascals abs feedstock______________________________________T.sub.3 175 4 · 10.sup.6 3A.sub.3 175 4 · 10.sup.6 3T.sub.4 175 4 · 10.sup.6 3A.sub.4 175 4 · 10.sup.6 3______________________________________
At the end of these tests and after separation of the solvent, an oil phase and an asphaltic phase are obtained. The yields obtained and the characteristics of these phases are determined. They are presented in Table 4 which follows.
TABLE 4__________________________________________________________________________ T.sub.3 A.sub.3 T.sub.4 Oil Asphaltic Oil Asphaltic Oil AsphalticTest phase phase phase phase phase phase__________________________________________________________________________Yield, wt. % 57.7 42.3 61.7 38.3 72.5 27.5Density at 15° C., kg/m.sup.3 (1) 986 984 974Index of refraction at 60° C. 1.5433 1.544 1.5362Viscosity at 100° C., mm.sup.2 /s (4) 200 197.1 59.5Conradson residue, wt. % (5) 9.8 40.2 10.2 41.9 8.1 45.0Asphaltene content, wt. % (6) 1.82 51.3 1.60 62.7 3.8 70.8Sulfur content, wt. % (7) 4.14 7.00 4.03 7.2 3.74 6.94Nickel content, ppm (7) 7 117 7 104 15 262Vanadium content, ppm (7) 22 332 24 348 95 1299__________________________________________________________________________ A.sub.4 Oil Asphaltic Test phase phase__________________________________________________________________________ Yield, wt. % 75.3 24.7 Density at 15° C., kg/m.sup.3 (1) 975 Index of refraction at 60° C. 1.5381 Viscosity at 100° C., mm.sup.2 /s (4) 62.9 Conradson residue, wt. % (5) 7.8 45.7 Asphaltene content, wt. % (6) 2.8 75.1 Sulfuir content, wt. % (7) 3.73 7.03 Nickel content, ppm (7) 15 248 Vanadium content, ppm (7) 99 1310__________________________________________________________________________ (1) In conformity with standard AFNOR NFT 60-101 (4) In conformity with standard AFNOR NFT 60-100 (5) In conformity with standard AFNOR NFT 60-116 (6) In conformity with standard AFNOR NFT 60-115 (7) Determined by xray fluorescene
The same conclusions may be drawn as with respect to Example 1. | A process for improving the deasphalting of a heavy hydrocarbon feedstock with a solvent by subjecting the feedstock to shearing alternatively after and/or before the addition of at least a portion of the solvent to the feedstock is disclosed. Alternative means for effecting the shearing and desired ranges of shear are also disclosed. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of application Ser. No. 34,605, filed Apr. 30, 1979, allowed which is a continuation-in-part of application Ser. No. 945,323, filed Sept. 25, 1978 now abandoned.
FIELD OF THE INVENTION
This invention is directed to polyamide resins containing certain additives which provide nucleating characteristics to the resins.
BACKGROUND OF THE INVENTION
Nucleating agents are usually employed as processing aids primarily to accelerate crystallization from a melt.
Acceleration of crystallization results in faster molding cycles, which of course means greater productivity in molding operations. Generally, nucleating agents are believed to provide sites for crystallization of molten polyamide. However, nucleating agents are also identified by their ability to increase tensile strength and stiffness of the polyamide, decrease elongation, and decrease mold shrinkage. The term "nucleating agent" as employed herein, is meant to denote those additives which increase tensile strength and decrease tensile elongation and mold shrinkage.
A deficiency of many nucleating agents is that they also significantly lower the Izod impact strength of the resin compared with that of the polyamide without nucleating agent. In contrast, the nucleating agents employed herein provide nucleating properties to polyamides but do not result in a significant lowering of Izod impact strength.
SUMMARY OF THE INVENTION
The product of this invention is a melt compounded blend consisting essentially of
(a) a polyamide resin having a molecular weight of at least 5000, and
(b) an adduct of maleic or fumaric anhydride and a copolymer of ethylene, at least one C 3 to C 6 α-olefin, and at least one nonconjugated diene, said adduct having an anhydride functionality of between about 0.1 and 4.0 milliequivalents of carboxyl groups per 1 gram of adduct, said adduct being present in the blend in an amount such that the anhydride functionality comprises between about 0.7 and 10 equivalents per 10 6 g of polyamide present; provided that the maximum amount of adduct present is less than 1 percent based on weight of polyamide and adduct; and provided that the adduct is in the form of finely divided particles having an average size less than 0.5 micron.
The process of this invention is a process for preparing the melt compounded blend described above by mixing the polyamide resin and the adduct and melt extruding the mixture.
DESCRIPTION OF THE INVENTION
The polyamide resins used in the blends of this invention are well known in the art and embrace those resins having a molecular weight of at least 5000 and commonly referred to as nylons. Suitable polyamides include those described in U.S. Pat. Nos. 2,071,250; 2,071,251; 2,130,523; 2,130,948; 2,241,322; 2,312,966; 2,512,606; and 3,393,210.
Preferably, the polyamides are those made by the condensation of linear diamines represented by the formula H 2 N--(CH 2 )x--NH 2 , where x is an integer between 6 and 12, with linear dicarboxylic acids represented by the formula HO 2 C--(CH 2 ) y --CO 2 H, where y is an integer between 2 and 8. Equally well, these polyamides may be made from amine-forming derivatives of said amines and acids such as esters, acid chlorides, amine salts, etc. Representative dicarboxylic acids used to make the polyamides include adipic acid, pimelic acid, suberic acid, sebacic acid, and dodecanedioic acid, while representative diamines include hexamethylene diamine and octamethylene diamine.
Examples of polyamides include polyhexamethylene adipamide (66 nylon), polyhexamethylene azelamide (69 nylon), polyhexamethylene sebacamide (610 nylon), and polyhexamethylene dodecanoamide (612 nylon), polycaprolactam, (nylon 6), polylauryl lactam, poly-11-amino-undecanoamide, bis-(paraaminocyclohexyl) methane dodecanoamide. It is also possible to use polyamides prepared by the copolymerization of two of the above polymers or terpolymerization of the above polymers or their components, as for example, a polymer made of adipic acid, and isophthalic acid and hexamethylene diamine. Preferably the polyamides are linear with a melting point in excess of 200° C. Also included in the blends of this invention are copolymers, such as a copolymer of nylon 6,6, and polylactams, e.g., nylon 6 (polycaprolactam); and blends of polyamides, such as a mixture of nylon 6,6 and nylon 6. Preferably the condensation polyamide employed herein is polyhexamethylene adipamide (nylon 6,6).
By the term "anhydride functionality" is meant the group ##STR1## The concentration of anhydride in the adduct is measured by infrared spectroscopy of hot pressed films. The amount of the adduct present to achieve the nucleation effect in the blend depends on the amount of anhydride functionality present in the adduct, provided the amount of polymer present is less than 1%. The amount of anhydride functionality present in the adduct is preferably between about 0.1 and 7 and most preferably between about 0.1 and 2 milliequivalents per gram. Preferably also the amount of adduct present in the blend is between about 0.7 and 7 equivalents of carboxyl groups per 10 6 g of polyamide polymer. It is believed, although not conclusively demonstrated, that the anhydride function of the adduct polymer reacts with amine ends of the polyamide to provide the nucleating effect seen in the blends.
The adduct may be prepared as described in Flexman U.S. Pat. No. 4,026,067 or Caywood U.S. Pat. No. 3,884,882 and U.S. Pat. No. 4,010,223. It preferably has an inherent viscosity of at least one as measured on 0.1 g of adduct in 100 ml of perchloroethylene at 30° C. Propylene is preferably the C 3 -C 6 α-olefin, although it can be 1-butene, 1-pentene or 1-hexene. A preferred class of nonconjugated dienes are monoreactive ones. Monoreactive nonconjugated dienes have one double bond which readily enters the copolymerization reaction with ethylene and propylene, and a second double bond which does not, to any appreciable extent, enter the copolymerization reaction. Copolymers of this class have maximum side chain unsaturation for a given diene content, which unsaturation is available for adduct formulation. Gel content of these copolymers is also minimal since there is minimal cross-linking during copolymerization. The nonconjugated dienes include linear aliphatic dienes of at least six carbon atoms which have one terminal double bond and one internal double bond, and cyclic dienes wherein one or both of the carbon-to-carbon double bonds are part of a carbocyclic ring. Of the linear dienes, copolymers of ethylene, propylene, and 1,4-hexadiene are especially preferred.
Class of cyclic dienes useful for adduct formation includes alkylidene bicycloalkenes, alkenyl bicycloalkenes, bicycloalkadienes, and alkenyl cycloalkenes. Representative of alkylidene bicycloalkenes are 5alkylidene-2-norbornenes such as 5-ethylidene-2-norbornene and 5-methylene-2-norbornene. Representative of alkenyl bicycloalkenes are 5-alkenyl-2-norbornenes such as 5-(1'-propenyl)-2-norbornene, 5-(2'-butenyl)-2-norbornene, and 5-hexenyl-2-norbornene. Dicyclopendadiene and 5-ethyl-2,5-norbornadiene are illustrative of bicycloalkadienes, and vinyl cyclohexene is representative of alkenyl cycloalkenes which may be selected as the diene monomer.
Another class of preferred copolymers includes branched tetrapolymers made from ethylene, at least one C 3 to C 6 α-monoolefin with propylene being preferred, at least one monoreactive nonconjugated diene, and at least one direactive nonconjugated diene such as 2,5-norbornadiene or 1,7-octadiene. By "direactive" is meant that both double bonds are capable of polymerizing during preparation of the copolymer. Tetrapolymers of this class preferably have an inherent viscosity of about 1.2 to 3.0, as measured on 0.1 gram copolymer dissolved in 100 milliliters of perchloroethylene at 30° C., for optimum processing properties. A preferred copolymer of this class is a tetrapolymer of ethylene, propylene, 1,4-hexadiene, and 2,5-norbornadiene. Such copolymers are described in Canadian Pat. Nos. 855,774 and 897,895.
The adducts used in this invention can be prepared by any process which intimately mixes maleic or fumaric anhydride with the copolymer without appreciable generation of free radicals, and which concurrently or subsequently heats the mixture to a temperature at which thermal addition occurs. Selected temperatures will generally be at least 225° C. to obtain adduct formation at acceptable rates and less than about 350° C. to avoid any significant polymer breakdown. Preferred temperature ranges will vary with the particular polymer and can readily be determined by one skilled in the art.
Mixing of the anhydride and copolymer can be by blending molten anhydride with copolymer in an internal mixer or extruder, or by blending finely divided dry maleic anhydride with copolymer on a well-ventilated rubber mill with concurrent or subsequent heating, such as in a hot press or mold. Temperatures necessary to achieve thermal grafting are sufficiently high to dehydrate the diacid, forming the anhydride in situ. Thus, diacid can be compounded with the copolymer instead of the anhydride when such is desired.
Preferred copolymers of ethylene, propylene, and 1,4-hexadiene are very resistant to free radical formation under high shear stress conditions and are readily mixed on conventional bulk processing equipment without gel formation. Care must be exercised, however, in selecting the mixing conditions for copolymers derived from strained ring dienes such as ethylidene norbornene. Such copolymers will readily generate free radicals when sheared at low temperatures, and are preferably mixed with the anhydride at high temperature, such as above 90° C. to avoid appreciable gel formation.
It is generally desired to form adducts containing about 0.5 to 9 percent, and preferably about 1 to 4 percent, by weight anhydride.
To prepare the melt compounded blends of this invention, the polyamide and the adduct are mixed by any usual means and melt extruded through an extruder. This procedure is referred to herein as "melt compounding". If the adduct is in finely ground, i.e., less than 0.5 micron in size, it can be mixed directly with the polyamide and extruded. If, however, it is in coarse or pellet form, it is preferable to first mix and extrude it with the polyamide in amounts of about 10-20 percent to form a concentrate, and then mix and extrude the concentrate with additional polyamide. When in this coarse form, an extruder must be employed which will masticate, or grind, the adduct into a size less than 0.5 micron. Such an extruder is a twin screw extruder. Ordinarily, the ingredients are dry blended and then extruded at a temperature above the melting point of the polyamide.
The blends of this invention may contain one or more conventional additives such as stabilizers and inhibitors of oxidative, thermal, and ultraviolet light degradation; lubricants and mold release agents, colorants including dyes and pigments, fibrous and particulate fillers and reinforcements, plasticizers, and the like. These additives are commonly added during the mixing step.
Representative oxidative and thermal stabilizers which may be present in blends of the present invention include Group I metal halides, e.g., sodium, potassium, lithium with cuprous halides, e.g., chloride, bromide, iodide; hindered phenols, hydroquinones, and varieties of substituted members of those groups and combinations thereof.
Representative ultraviolet light stabilizers, include various substituted resorcinols, salicylates, benzotriazoles, benzophenones, and the like.
Representative lubricants and mold release agents include stearic acid, stearyl alcohol, and stearamides. Representative organic dyes include nigrosine, while representative pigments, include titanium dioxide, cadmium sulfide, cadmium selenide, phthalocyanines, ultramarine blue, carbon black, and the like. Representative fillers include carbon fibers, glass fibers, amorphous silica, asbestos, calcium silicate, aluminum silicate, magnesium carbonate, kaolin, chalk, powdered quartz, mica, feldspar, and the like.
EXAMPLES
In the Examples which follow, the concentration of anhydride functionally in the adduct was measured by pressing it to form a film. The film was then subjected to infrared wavelengths in an infrared spectrometer and the maximum infrared value of the anhydride was compared to a standard to determine the degree of anhydride functionality present.
Tensile strength and elongation measurements were made by ASTM D638 on 1/8-inch thick specimens pulled at 2 inches per minute, and Izod impact strength was determined by ASTM D256 on 1/8-inch thick specimens, except that specimens were used dry as molded.
Mold shrinkage was determined by measuring the length of five 1/8-inch thick tensile test bars and subtracting the average from the length of the mold cavity. The difference is divided by the length of the cavity to give mold shrinkage in dimensionless units of in/in. All measurements were at room temperature.
Particle size of the adduct was determined by making photographs with a transmission electron microscope. Specimens were cut from molded test bars with an ultramicrotome at -90° C. Sections were stained overnight with phosphotungstic acid before examination. The magnification was 11,800× (1.18 cm=1 micron). Particles of the adduct polymer are white. By visually examining the photograph's average particle size is estimated.
The following adducts were employed:
Adduct Polymer 1A
A polymer of fumaric acid grafted onto a polymer of ethylene, propylene, 1,4-hexadiene and norbornadiene was prepared. Analysis for anhydride functionally provided a result of 0.31 meq/g acid.
Adduct Polymer 1B
Another sample of the same polymer as in Adduct Polymer 1A was prepared. The anhydride functionality was 0.71 meq/g acid.
In the Examples and controls, the appropriate adduct was mixed with nylon pellets or powder by tumbling in a polyethylene bag.
Adducts 1A and 1B were obtained in pellet form, and to ensure good mixing, a two-step mixing procedure was employed. A 10 percent by weight mixture of adduct in the nylon was first obtained by tumbling and extrusion. Then this 10 percent mixture was diluted with more nylon and tumbled and extruded again to obtain blends of desired adduct concentration. The pellet blends were extruded at 270° C. in a 28 mm Werner and Pfleiderer twin screw extruder.
The extrusion blends prepared were molded by injection molding. A melt temperature of 285° C., a mold temperature of 90° C., and an injection melt pressure of 10,700 psi were employed at a cycle time of 50 seconds.
EXAMPLE 1
Properties of Nylon 66 Containing Adduct Polymer 1A
(EPHDE-g-F)
______________________________________Adduct IzodConcentration Tensile Elonga- ImpactWt Acid Strength tion Strength% Eq/10.sup.6 g psi % Ft lb/in______________________________________None.sup.1 11,800 67 .9.25.sup.2 .78 12,300 37 .85.5.sup.2,3 1.55 12,600 39 .85.75.sup.2 2.33 12,500 39 .85______________________________________
______________________________________Adduct MoldConcentration Shrink- Particle SizeWt Acid age of Adduct% Eq/10.sup.6 g in/in in the Molding (microns)______________________________________None.sup.1 .016 --.25.sup.2 .78 .014 <.5.5.sup.2 1.55 .013 <.5.75.sup.2 2.33 .012 <.5______________________________________ .sup.1 Nylon 66 control (Zytel® 101) .sup.2 These also contained .3 percent Nstearyl erucamide lubricant for mold release.
As seen from the Table, the adduct increased tensile strength and decreased elongation and mold shrinkage.
EXAMPLE 2
Properties of Nylon 66 Containing Adduct Polymer 1B
______________________________________Adduct IzodConcentration Tensile Elonga- ImpactWt Acid Strength tion Strength% Eq/10.sup.6 g psi % Ft lb/in______________________________________None.sup.1 12,000 65 1.0.3 2.1 12,800 31 1.0.9 6.3 12,900 26 1.1______________________________________
______________________________________Adduct MoldConcentration Shrink- Particle SizeWt Acid age of Adduct% Eq/10.sup.6 g in/in in the Molding(micron)______________________________________None .sup.1 .017 --.3 2.1 .015 --.9 6.3 .013 <.5______________________________________ .sup.1 Nylon 66 control (Zytel® 101)
As seen from the table, the same results are generally obtained as with Example 1. | A melt compounded blend of a nylon resin and a small amount of a finely divided adduct which contains a requisite amount of anhydride functionality. The adduct polymer is found to provide nucleating effects to the resultant blend. | 2 |
BACKGROUND OF THE INVENTION
The present invention relates to a method of controlling a fuel injection and an apparatus therefor, and more particularly to a method of and an apparatus for controlling a fuel injection suitable for an engine of an automobile so as to optimize an air-fuel ratio for the engine during acceleration and deceleration of the automobile.
It is general practice in a fuel injection type internal combustion engine to calculate a fuel injection quantity on the basis of both intake-pipe absolute pressure and engine speed or both intake-air quantity and engine speed and to equally add a predetermined output incremental value to the calculated fuel injection quantity when a throttle valve of the engine has an opening amount more than its intermediate opening amount, e.g., 30° or more, thereby to obtain a necessary output.
When the above-mentioned output incremental value is excessively large, however, the output change becomes so large as to cause a shock. On the other hand, if the output incremental value is set to be relatively low in order to prevent such shock, it may not be possible to obtain excellent engine responsiveness during acceleration.
The above-described fuel injection type internal combustion engine includes such a type of engine that the air-fuel ratio for the engine is controlled to the leaner side for the purpose of reduction in fuel cost when the throttle valve has a small opening amount, e.g., 30° or less and after the engine has been completely warmed up. When an output air-fuel ratio, at which the maximum output torque is obtained, is obtained in such internal combustion engine by effecting the output incremental correction as described above, the air-fuel ratio quickly changes from a lean air-fuel ratio, e.g., 22 to the output air-fuel ratio, e.g., 12.5. Accordingly, when the throttle valve changes its open position from a small opening amount to an intermediate opening amount, a shock is caused which is unpleasant to the driver. It is to be noted that when the throttle valve changes its open position from a small opening amount to a large opening amount, the driver himself has the intention of sudden acceleration. Therefore, any shock resulting from the acceleration will not make the driver feel unpleasant.
SUMMARY OF THE INVENTION
Accordingly, it is a primary object of the invention to provide a method of and an apparatus for controlling a fuel injection which solve the above-described contradictory problems of the prior art and makes it possible to prevent any shock resulting from the output incremental correction while obtaining an excellent engine responsiveness during accleration.
To this end, according to the invention, there is provided a method of controlling a fuel injection wherein a fuel injection quantity is calculated on the basis of engine speed and engine load and is corrected by an output incremental value determined in accordance with acceleration and deceleration of an engine, at least, comprising the steps of: detecting the position of an intake throttle valve with regard to whether it is located within a small-opening region, an intermediate-opening region or a large-opening region; increasing the output incremental value to its maximum value when the intake throttle valve is switched over from the small-opening region to the large-opening region; increasing the output incremental value such that it gradually approaches the maximum value when the intake throttle valve is switched over from the small-opening region to the intermediate-opening region; decreasing the output incremental value to almost zero when the intake throttle valve is switched over from the large-opening region to the small-opening region; and gradually attenuating the output incremental value toward almost zero when the intake throttle valve is switched over from the large-opening region to the intermediate-opening region.
According to the invention, when the throttle valve is quickly changed from the small-opening region to the large-opening region, the output incremental value is maximized to obtain a new output air-fuel ratio. When the throttle valve is changed from the small-opening region to the intermediate-opening region, the output incremental value is increased such that it gradually approaches its maximum value. In contrast, when the throttle valve is quickly changed from the large-opening region to the small-opening region, the output incremental value is decreased to almost zero. Further, when the throttle valve is changed from the large-opening region to the intermediate-opening region, the output incremental value is attenuated such as to gradually approach almost zero. Therefore, it is possible to ease the unpleasant shock experienced by the driver which occurs when the throttle valve is switched over from the small-opening region to the intermediate-opening region or from the large-opening region to the intermediate-opening region. Moreover, it is possible to obtain an engine responsiveness during acceleration which is satisfactory to the driver.
The above and other objects, features and advantages of the invention will become clear from the following description of the preferred embodiment thereof, taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an illustration of the arrangement of an example of an internal combustion engine to which the invention is applied;
FIG. 2 is an illustration of an example of the throttle sensor of FIG. 1;
FIG. 3 is a detailed block diagram of an example of the control circuit of FIG. 1;
FIG. 4 is a flow chart showing an example of a main routine employed in the invention;
FIG. 5 is a graph showing the relationship between the output incremental value Δτ and the ignition timing retardation amount Δθ;
FIG. 6 is a program flow chart showing an example of an injection interrupt routine;
FIG. 7 is a program flow chart showing an example of an ignition interrupt routine;
FIGS. 8A and 8B are a program flow chart showing an example of an output incremental routine;
FIG. 9 is a program flow chart showing an example of an output incremental sub-routine;
FIGS. 10 and 11 are graphs each showing the change of the output incremental value Δτ with time; and
FIG. 12 shows the output incremental value Δτ obtained by the routines of FIGS. 8 and 9.
DESCRIPTION OF THE PREFERRED EMBODIMENT
An embodiment of the invention will be described hereinunder in detail with reference to the accompanying drawings.
FIG. 1 shows an example of an electronically controlled fuel injection type internal combustion engine to which the invention is applied. In this Figure, the reference numeral 10 denotes an engine body, the numeral 12 an intake passage, the numeral 14 a combustion chamber, and the numeral 16 an exhaust passage. An intake-pipe absolute pressure sensor 20 is provided in the part of the intake passage 12 on the downstream side of a throttle valve 18. The pressure sensor 20 is connected to a control circuit 22 through a signal line l 1 and is adapted to generate a voltage corresponding to an intake-pipe absolute pressure. An intake-air temperature sensor 21 is provided in the part of the intake passage 12 which is on the upstream side of the throttle valve 18. The intake-air temperature sensor 21 is connected to the control circuit 22 through a signal line l 2 and is adapted to generate a voltage corresponding to an intake-air temperature. The intake air, which is introduced in through an air cleaner (not shown) and is controlled in flow rate by the throttle valve 18 which is interlocked with an acceleration pedal (not shown), is led to the combustion chamber 14 of each cylinder through a surge tank 24 and an intake valve 25.
A fuel injection valve 26 is provided for each cylinder and is arranged such that its opening/closing operation is controlled in accordance with electrical driving pulses supplied from the control circuit 22 through a signal line l 3 . The fuel injection valve 26 injects a pressurized fuel supplied from a fuel supply system (not shown) into the part of the intake passage 12 in the vicinity of the intake valve 25, that is, an intake port portion. The exhaust gas resulting from the combustion of the fuel in the combustion chamber 14 is discharged into the atmospheric air through an exhaust valve 28, the exhaust passage 16 and an oxidation catalyst 30.
A distributor 38 of the engine is equipped with crank angle sensors 40 and 42, which are connected to the control circuit 22 through respective signal lines l 6 , l 7 . The sensor 40 delivers a pulse signal every 30° rotation of the crankshaft, while the sensor 42 delivers a pulse signal every 360° rotation of the crankshaft. These pulse signals are supplied to the control circuit 22 through respective signal lines l 6 , l 7 . The distributor 38 is connected to an ignitor 39, which is in turn connected to the control circuit 22 through a signal line l 8 .
A throttle sensor 44 which detects the opening amount of the throttle valve 18 has, as shown in FIG. 2 in detail: a shaft 44a which rotates in either direction in one unit with the pivot of the throttle valve 18; a rotor 44b secured to the shaft 44a; a first contact 44c attached to the endmost portion of the rotor 44b; a second contact 44d attached to the portion of the rotor 44b closer to the center of rotation thereof; a first conductor plate 44e disposed within an intermediate-opening region of the throttle valve 18 ranging between rotor pivoting angles 30° and 60° and adapted to be able to contact the first contact 44c within that angle range; a second conductor plate 44f disposed within a large-opening region of the throttle valve 18 ranging between rotor pivoting angles 60° and 90° and adapted to be able to contact the second contact 44d within that angle range; a lead 44g connected to the first conductor plate 44e; a lead 44h connected to the second conductor plate 44f; and a lead 44i for applying a battery voltage to the side of the rotor 44b close to the center of rotation thereof. The leads 44g, 44h are connected to the control circuit 22 through respective signal lines l 4 , l 5 .
The throttle sensor 44 operates as follows: when the throttle valve 18 is within the small-opening region ranging from 0° to less than 30°, the output voltages delivered through the leads 44g and 44h are both zero; when the throttle valve 18 is within the intermediate-opening region ranging from 30° to less than 60°, the output voltage delivered through the lead 44g has a high level, while the output voltage delivered through the lead 44h is zero; and when the throttle valve 18 is within the large-opening region ranging from 60° to less than 90°, the output voltage delivered through the lead 44g is zero, while the output voltage delivered through the lead 44h has a high level. Thus, if the high level is represented by "1", the zero level by "0", the output signal delivered from the first conductor plate 44e through the lead 44g by f1, and the output signal from the second conductor plate 44f through the lead 44h by f2, then the pivoting angle of the throttle valve 18 may be expressed in accordance with the output signals f1, f2 as shown in Table 1 below.
TABLE 1______________________________________Throttle valve opening region Output signal f1 Output signal f2______________________________________Small 0 0Intermediate 1 0Large 0 1______________________________________
Referring back to FIG. 1, the exhaust passage 16 is provided therein with a lean sensor 46 which delivers a signal in response to the oxygen concentration contained in the exhaust gas, that is, generates an output voltage with a magnitude substantially proportional to an air-fuel ratio when it is leaner than a stoichiometric air-fuel ratio. The lean sensor 46 is connected to the control circuit 22 through a signal line l 9 . The oxidation catalyst 30 is provided on the downstream side of the lean sensor 46 so as to purify HC and CO in the exhaust gas.
Further, the reference numeral 48 denotes a water temperature sensor adapted to detect the temperature of water for cooling the engine and to generate a voltage corresponding to the detected temperature. The water temperature sensor 48 is attached to a cylinder block 50 and is connected to the control circuit 22 through a signal line l 10 .
The control circuit 22 is, as shown in FIG. 3, composed of: a central processing unit (CPU) 22a which controls various devices; a read-only memory (ROM) 22b having various numerals and programs previously written thereinto; a random-access memory (RAM) 22c into which numerals and flags generated in the course of calculations are written and stored in their respective predetermined regions; an A/D converter (ADC) 22d which has an analog multiplexer function and converts an analog input signal into a digital signal; an input/output interface (I/O) 22e into which various digital signals are fed; an input/output interface (I/O) 22f from which various digital signals are delivered; a backup memory (BU-RAM) 22g which is supplied with power from an auxiliary power source at the time of suspension of the engine so as to hold stored data; and a bus line 22h connected with these devices.
The ROM 22b has previously stored therein a main routine program, an injection execution interrupt routine program, an ignition execution interrupt routine program, an output increment interrupt routine program, other sub-routine programs and various data required for various calculations.
The pressure sensor 20, the intake-air temperature sensor 21, the lean sensor 46 and the water temperature sensor 48 are connected to the A/D converter 22d, where voltage signals S1, S2, S3, S4 respectively delivered from the sensors are successively converted into respective binary signals according to instructions from the CPU 22a.
A pulse signal S5 delivered from the crank angle sensor 40 every crank angle of 30°, a pulse signal S6 delivered from the crank angle sensor 42 every crank angle of 360° and the output signals f1, f2 delivered from the throttle sensor 44 are fed to the control circuit 22 through the I/O 22e. On the basis of the pulse signal S5, a binary signal representing an engine speed is formed, while the pulse signals S5 and S6 cooperate with each other to form an interrupt request signal for calculating a fuel injection pulse width, a fuel injection start signal and a cylinder discriminating signal. According to the output signals f1, f2, the opening of the throttle valve 18 is determined as described above.
From the I/O 22f, a fuel injection pulse S10 and an ignition signal S11 formed by various calculations are respectively delivered to each of the fuel injection valves 26a to 26d and the ignitor 39 at predetermined timings.
In the internal combustion engine thus constructed, a basic fuel injection time duration TP representing a basic fuel injection quantity is calculated on the basis of both an intake-pipe pressure PM representative of engine loads and an engine speed NE, and the basic fuel injection time duration TP is corrected in accordance with various calculations to determine an injection time duration τ.
For example, the injection time duration τ after correction is obtained by the following equation:
τ=TP×F+Δτ (1)
The calculation of the injection time duration τ is executed in a step S1 in the procedure for the main routine shown in FIG. 4. The symbol Δτ in the equation (1) represents an output incremental value, which is calculated through an output increment routine shown in FIG. 8 and an output increment sub-routine shown in FIG. 9.
It is to be noted that the symbol F in the equation (1) represents a correction coefficient employed for the increment in accordance with the water temperature and the like and the decrement by the lean control and the like. In this embodiment, when the throttle valve is at an open position within the small-opening region and after the engine has been completely warmed up, a lean feedback control is effected on the basis of the signal from the lean sensor 46, so that the air-fuel ratio is brought into a stoichiometric level. In addition to this control, when the throttle valve is at an open position out of the small-opening region, an open-loop control is effected, thereby to allow the air-fuel ratio to approach the output air-fuel ratio. In a step S2 in the main routine of FIG. 4, an ignition timing correction quantity Δθ in accordance with the output incremental value Δτ is calculated. In a step S3, the correction quantity Δθ is added to a basic ignition timing θ BASE determined by both the intake-pipe pressure PM and the engine speed NE to calculate a final ignition timing θ. In this case, the correction quantity Δθ can be obtained from a graph of FIG. 5 which shows the relationship between Δθ and Δτ, and is predetermined such as to increase as the output incremental value Δτ increases.
It is to be noted that the fuel injection quantity or the fuel injection time duration τ thus obtained is formed as a signal S10 delivered to the injection valve. When an injection interrupt routine shown in FIG. 6 is started in accordance with a predetermined crank angle, the signal S10 is supplied to the injection valve 26 in a step S4 of the injection interrupt routine so as to open the injection valve 26 for a period of time represented by the signal S10. In an ignition interrupt routine shown in FIG. 7, on the other hand, in a step S5, the ignition signal S11 is supplied to the ignitor 39 at the timing which is coincident with the ignition timing θ to apply a high voltage to the ignition plug.
An example of a routine for calculating the output incremental value Δτ will be described hereinunder with reference to FIG. 8. This routine is executed at a predetermined interval counted by a timer, so the routine is so called a timer interrupt routine. When this routine is started, in a step S10, the present position of the throttle valve 18 is stored in predetermined memory regions M1, M2 on the basis of the signals f1, f2 from the throttle sensor 44. At this time, the data already stored in the regions M1, M2 are respectively shifted to other memory regions M11, M12 as signals f11, f12 representing the previous position of the throttle valve 18. In a step S20, the previous position of the throttle valve 18 is judged on the basis of the data stored in the memory regions M11, M12.
(A) When the previous throttle valve position is within the small-opening region (f11=0, f12=0):
The process proceeds to a step 30 in which the signals f1, f2 representing the present throttle valve position are judged on the basis of the values of the memory regions M1, M2.
a When the present throttle valve position is within the small-opening region (f1=0, f2=0):
In a step S301, a flag f R is reset ("0"), and a judgement is made in a step S302 as to whether a flag f L is up ("1") or not. If No, the routine is ended without executing the output increment sub-routine shown in FIG. 9, described later. In this case, the fuel injection quantity τ is obtained from the output incremental value Δτ obtained in the previous calculation and stored in the memory region M3 alloted to the output incremental value Δτ. If Yes, in a step S303, a correction data C to be added to the output incremental value Δτ in the output increment sub-routine of FIG. 9 is set to be a predetermined negative value -K, and the output increment sub-routine is executed in a step 312 to end this routine.
b When the present throttle valve position is within the intermediate-opening region (f1=1, f2=0):
In a step S311, the flag f L is reset ("0"), while the flag f R is set ("1"), and the correction data C is set to be a predetermined positive value K, and the sub-routine of FIG. 9 is executed in the step S312 to end this routine.
c When the present throttle valve position is within the large-opening region (f1=0, f2=1):
In a step S321, both the flags f L and f R are reset ("0"), and the output incremental value Δτ is set to be a maximum value Ce, and this routine is ended without executing the output increment sub-routine of FIG. 9.
(B) When the previous throttle valve position is within the intermediate-opening region (f11=1, f12=0):
The process proceeds to a step S40 in which the signals f1, f2 representing the present throttle valve position are judged on the basis of the values of the memory regions M1, M2.
a When the present throttle valve position is within the small-opening region (f1=0, f2=0):
In a step S401, the flag f L is set ("1"), and the flag f R is reset ("0"), and in a step S402, the correction data C is set to be a predetermined negative value -K. Further, the sub-routine of FIG. 9 is executed in a step S403 to end this routine.
b When the present throttle valve position is within the intermediate-opening region (f1=1, f2=0):
In a step S411, a judgement is made as to whether or not the flag f L is up ("1"). If Yes, the process proceeds through the step S402 to the step S403 in which the sub-routine of FIG. 9 is executed to end this routine. If No in the step S411, the process proceeds to a step 412 in which a judgement is made as to whether the flag f R is up ("1") or not. If Yes in a step S413, the correction data C is set to be a predetermined positive value K, and the process proceeds to the step S403 in which the sub-routine of FIG. 9 is executed to end this routine. If No in the step S412, the routine is ended without executing the sub-routine of FIG. 9. Also in this case, the fuel injection quantity τ is obtained from the output incremental value Δτ obtained by the previous calculation similarly to the above-described case.
c When the present throttle valve position is within the large-opening region (f1=0, f2=1):
In a step S414, the flag f L is reset ("0"), while the flag f R is set ("1"), and the correction data C is set to be a predetermined positive value K. The process proceeds to a step S415 in which the sub-routine of FIG. 9 is executed to end this routine.
(C) When the previous throttle valve position is within the large-opening region (f11=0, f12=1):
The process proceeds to a step S50 in which the signals f1, f2 representing the present throttle valve position are judged on the basis of the values of the memory regions M1, M2.
a When the present throttle valve position is within the small-opening region (f1=0, f2=0):
In a step S501, both the flags f L and f R are reset ("0"), and the output incremental value Δτ is made zero to end this routine.
b When the present throttle valve position is within the intermediate-opening region (f1=1, f2=0):
In a step S511, the flag f L is set ("1"), while the flag f R is reset ("0"), and the correction data C is set to be a predetermined negative value -K. The process proceeds to a step S512 in which the output increment sub-routine of FIG. 9 is executed to end this routine.
c When the present throttle valve position is within the large-opening region (f1=0, f2=1):
In a step S521, the flag f L is reset ("0"). Then the process proceeds to a step S522 in which a judgement is made as to whether the flag f R is up ("1") or not. If No, this routine is ended without executing the sub-routine of FIG. 9. Also in this case, the fuel injection quantity τ is obtained from the output incremental value Δτ obtained by the previous calculation similarly to the above-described cases. If Yes in the step S522, the correction data C is set to be a predetermined positive value K in a step S523. Then, and the sub-routine of FIG. 9 is ended in the step S512.
The following is a description of the sub-routine for the output increment calculation shown in FIG. 9.
Upon start of this output increment sub-routine in response to the steps S312, S403, S415 or S512 of FIG. 8, in a step S61, the output incremental value Δτ read out from the memory region M3 is added to correction data C. The result of the addition is stored in the memory region M3 as a new output incremental value Δτ. Then the process proceeds to a step S62 where a judgement is made as to whether or not the new output incremental value Δτ is zero or less. If the output incremental value Δτ is zero or less, in a step S63, the flag f L is reset ("0"), and the output incremental value Δτ is set to be zero to end this routine.
On the other hand, if a negative answer is judged in the step S62, the process proceeds to a step S64 in which a judgement is made as to whether the output incremental value Δτ is larger than the maximum value Ce or not. If the value Δτ is not larger than the maximum value Ce, this routine is ended. If the output incremental value Δτ exceeds the maximum value Ce, the process proceeds to a step S65 in which the flag f R is reset ("0"), and the output incremental value Δτ is set to be the maximum value Ce to end this routine.
For example, in the case where the opening region of the throttle valve 18 changes from the small-opening region to the intermediate-opening region and the automobile continues running for a while in this state, the flag f R maintains its high ("1") state until the output incremental value Δτ exceeds the maximum value Ce. Therefore, every time the sub-routine of FIG. 9 is started, the output incremental value Δτ increases by +K as shown in FIG. 10. On the other hand, in the case, for example, where the opening region of the throttle valve 18 changes from the intermediate-opening region to the small-opening region and the automobile continues running for a while in this state, the flag f L maintains its high ("1") state until the output incremental value Δτ becomes zero. Therefore, every time the sub-routine of FIG. 9 is started, the output incremental value Δτ decreases by -K as shown in FIG. 11.
As has been described, in one embodiment of the invention, the output incremental value Δτ is controlled in accordance with the variation of the throttle valve 18 as shown in FIG. 12. In FIG. 12, a change in throttle opening region, as shown within the solid line rectangle causes the flags f L and f R to be equally set or rese. Therefore, the output incremental value Δτ is independent of the opening region of the throttle valve 18 detected by the detection carried out just before the previous detection. However, at the time of other throttle opening region changes, the output incremental value Δτ is affected by the flags f L and f R set in accordance with the throttle opening region change having occurred during the period from the detection effected just before the previous one to the previous detection or the throttle opening region change having occurred therebefore. Taking No. 6 and No. 7 shown in FIG. 12, for instance, where the engine operation within the intermediate-opening region continues for a while, the output incremental value Δτ is gradually increased or attenuated according to the flags set or reset in accordance with the throttle opening region change having occurred during the period from the detection carried out just before the previous one to the previous detection or the throttle opening region change having occurred therebefore. It is to be noted that in FIG. 12 each throttle opening region change shown within the broken line rectangle is the same as the corresponding throttle opening region change shown within the solid line rectangle.
As described above, in one embodiment of the invention, the output increment Δτ is properly determined in accordance with various changes in opening amount of the throttle valve 18. Therefore, it is possible to prevent any unpleasant shock under any operating conditions, and yet to improve the engine responsiveness during acceleration. Further, in this embodiment, throttle sensor 44 is employed which respectively delivers three different output signals for the small-opening region, the intermediate-opening region and the large-opening region of the throttle valve 18, and the three output signals are employed as they are to discriminate between the three regions of throttle opening. Accordingly, the need for any A/D converter is conveniently eliminated and the programs are favorably simplified as compared with the case where a potentiometer, for example, is employed to A/D convert a voltage corresponding to a pivoting angle of the throttle valve for the purpose of discriminating between the three regions.
Although in the above the invention has been described through one embodiment thereof in which the fuel injection quantity is calculated on the basis of the intake-pipe absolute pressure and the engine speed, the described embodiment is not exclusive and the fuel injection quantity may be calculated on the basis of the intake-air quantity measured by employing an air-flow meter and the engine speed.
Moreover, the invention has been described above by reference to an engine in which, when the intake throttle valve is at an open position within the small-opening region and after the engine has been completely warmed up, an overall lean feedback control is effected by using the lean sensor, while when the throttle valve is at an open position outside the small-opening region, that is, within the intermediate- or large-opening region, an open-loop control is effected, and a so-called stoichiometric air-fuel ratio control is not carried out. The invention is, however, not limited to use in such an engine. In other words, the invention is applicable to an engine adopting a so-called partial lean control in which, for example, the air-fuel ratio is controlled to the leaner side in the case where the throttle valve position is within the small-opening region, the engine has been completely warmed up and moreover the vehicle speed does not exceed a predetermined value, and when the throttle valve position is out of the small-opening region, that is, within the intermediate- or large-opening region, the air-fuel ratio is controlled by feedback so as to be in proximity of a stoichiometric air-fuel ratio. In such case, in place of the lean sensor, a so-called O 2 sensor may be employed. An output voltage of the O 2 sensor is stepwise changed in the vicinity of the stoichiometric air-fuel ratio, so that the air-fuel ratio is detected by the O 2 sensor. In addition, in place of the oxidation catalyst, a three-way catalyst is employed which simultaneously purifies HC, CO and NO x .
Furthermore, the invention is also applicable to an engine in which neither overall lean control nor partial lean control is carried out but the output increment of fuel is effected when the throttle valve has an opening amount larger than that in the intermediate-opening region. | A fuel injection quantity is calculated on the basis of an engine speed and an engine load and is corrected by an output incremental value determined in accordance with acceleration and deceleration of an engine, at least. The position of an intake throttle valve is detected with regard to whether it is located within a small-opening region, an intermediate-opening region or a large-opening region. When the intake throttle valve is switched over from the small-opening region to the large-opening region, the output incremental value is increased to its maximum value. When the intake throttle valve is switched over from the small-opening region to the intermediate-opening region, the output incremental value is increased such as to gradually approach the maximum value. When the intake throttle valve is switched over from the large-opening region to the small-opening region, the output incremental value is decreased to almost zero. Further, when the intake throttle valve is switched over from the large-opening region to the intermediate-opening region, the output incremental value is gradually attenuated toward almost zero. | 5 |
CROSS-REFERENCE TO RELATED APPLICATION(S)
This application claims priority from Korean Patent Application No. 10-2011-0066942, filed on Jul. 6, 2011, in the Korean Intellectual Property Office (KIPO), the entire contents of which are incorporated herein by reference.
BACKGROUND
Example embodiments relate to semiconductor manufacturing apparatuses and/or methods of manufacturing semiconductors. Example embodiments may relate to an apparatuses for removing failed semiconductor chips from boards and/or methods of removing failed semiconductor chips from boards.
Recently, the demand for a board manufactured by a flip chip method among printed circuit boards (PCB) is increasingly growing. The board manufactured by a flip chip method is a board of which a functional characteristic and an electrical characteristic are improved by connecting a semiconductor chip and a board with a solder bump replacing an existing wire. The board manufactured by a flip chip method may be shipped after goods pass the installation test which is one of module processes. The goods which failed to pass the installation test may be repaired after a failed semiconductor chip is removed from the board. However, a conventional technique of removing a failed semiconductor chip is not standardized and depends on a manual labor of an engineer.
SUMMARY
Example embodiments may provide removal apparatuses for semiconductor chips. Example embodiments also may provide methods of removing semiconductor chips from boards.
In some example embodiments, a removal apparatus for a semiconductor chip may include a stage configured to support a board on which the semiconductor chip is mounted by bumps, a laser configured to irradiate a laser beam into the board over an area larger than the semiconductor chip, and/or a picker configured to cause the laser beam to penetrate the semiconductor chip locally and to separate the semiconductor chip from the board.
In some example embodiments, the picker may include a lens configured to focus the laser beam on the semiconductor chip.
In some example embodiments, the removal apparatus may further include a vacuum portion configured to provide a vacuum to the picker.
In some example embodiments, the picker may further define an open hole configured to draw the semiconductor chip using the vacuum provided from the vacuum portion and/or to cause the laser beam focused by the lens to penetrate the semiconductor chip.
In some example embodiments, the picker may further define an open hole configured to draw the semiconductor chip using the vacuum provided from the vacuum portion and/or to cause the laser beam focused by the lens to penetrate the semiconductor chip.
In some example embodiments, the removal apparatus may further include a drive portion configured to move the picker and the intake around the stage.
In some example embodiments, the removal apparatus may further include an air knife configured to blow high temperature air on the solder pillars.
In some example embodiments, the removal apparatus may further include a coining plate configured to compress the solder pillars.
In some example embodiments, the removal apparatus may further include a nozzle configured to spray flux on the solder pillars.
In some example embodiments, the removal apparatus may further include a loader configured to load the board on the stage and/or an unloader configured to unload the board from the stage.
In some example embodiments, the removal apparatus may further include a semiconductor chip recognition portion configured to recognize the semiconductor chip on the board.
In some example embodiments, an apparatus for removing a semiconductor chip from a board may include a laser configured to irradiate the board with a laser beam to heat bumps mounting the semiconductor chip on the board and/or a picker configured to separate the semiconductor chip from the board.
In some example embodiments, the laser beam may be configured to irradiate the board over a first area of the board that is larger than the semiconductor chip.
In some example embodiments, the apparatus may further include a vacuum portion configured to provide a vacuum to the picker.
In some example embodiments, the picker may define an open hole configured to draw the semiconductor chip using the vacuum provided from the vacuum portion.
In some example embodiments, the picker may include a lens configured to focus the laser beam on the semiconductor chip.
In some example embodiments, the lens may be configured to focus the laser beam on a second area of the board that is smaller than the semiconductor chip.
In some example embodiments, the lens may be configured to focus the laser beam to heat the bumps mounting the semiconductor chip on the board.
In some example embodiments, the apparatus may further include a vacuum portion configured to provide a vacuum to the picker.
In some example embodiments, the picker may further define an open hole drawing the semiconductor chip using the vacuum provided from the vacuum portion and/or the lens may be configured to focus the laser beam to heat the bumps mounting the semiconductor chip on the board.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and/or other aspects and advantages will become more apparent and more readily appreciated from the following detailed description of example embodiments, taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a top plan view illustrating a removal apparatus of semiconductor chip in accordance with some example embodiments;
FIG. 2 is a cross-sectional view illustrating a laser and a chip picker illustrated in FIG. 1 ;
FIG. 3 is a top plan view illustrating a second exposure area of a laser beam illustrated in FIG. 2 ;
FIG. 4 is a cross-sectional view illustrating a laser and an intake illustrated in FIG. 1 ;
FIG. 5 is a top plan view illustrating a first exposure area of a laser beam illustrated in FIG. 4 ;
FIG. 6 is a cross-sectional view illustrating a laser and a coining unit illustrated in FIG. 1 ;
FIG. 7 is a cross-sectional view illustrating a laser and a flux nozzle illustrated in FIG. 1 ; and
FIG. 8 is a flow chart illustrating a method of removing a semiconductor chip in accordance with some example embodiments.
DETAILED DESCRIPTION
Example embodiments will now be described more fully with reference to the accompanying drawings. Embodiments, however, may be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these example embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope to those skilled in the art. In the drawings, the thicknesses of layers and regions may be exaggerated for clarity.
It will be understood that when an element is referred to as being “on,” “connected to,” “electrically connected to,” or “coupled to” to another component, it may be directly on, connected to, electrically connected to, or coupled to the other component or intervening components may be present. In contrast, when a component is referred to as being “directly on,” “directly connected to,” “directly electrically connected to,” or “directly coupled to” another component, there are no intervening components present. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.
It will be understood that although the terms first, second, third, etc., may be used herein to describe various elements, components, regions, layers, and/or sections, these elements, components, regions, layers, and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer, and/or section from another element, component, region, layer, and/or section. For example, a first element, component, region, layer, and/or section could be termed a second element, component, region, layer, and/or section without departing from the teachings of example embodiments.
Spatially relative terms, such as “beneath,” “below,” “lower,” “above,” “upper,” and the like may be used herein for ease of description to describe the relationship of one component and/or feature to another component and/or feature, or other component(s) and/or feature(s), as illustrated in the drawings. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures.
The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises,” “comprising,” “includes,” and/or “including,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which example embodiments belong. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and should not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
Reference will now be made to example embodiments, which are illustrated in the accompanying drawings, wherein like reference numerals may refer to like components throughout.
FIG. 1 is a top plan view illustrating a removal apparatus of semiconductor chip in accordance with some example embodiments. FIG. 2 is a cross-sectional view illustrating a laser and a chip picker illustrated in FIG. 1 . FIG. 3 is a top plan view illustrating a second exposure area of a laser beam illustrated in FIG. 2 . FIG. 4 is a cross-sectional view illustrating a laser and an intake illustrated in FIG. 1 . FIG. 5 is a top plan view illustrating a first exposure area of a laser beam illustrated in FIG. 4 .
Referring to FIGS. 1 through 5 , a removal apparatus for a semiconductor chip in accordance with some example embodiments of the inventive concept may heat a semiconductor chip 70 and solder pillars 82 using a laser beam 22 from a laser 20 , and may melt solder bumps 80 under the semiconductor chip 70 and the solder pillars 82 . The laser beam 22 may be focused on the semiconductor chip 70 by a lens 33 of a picker 34 . The laser beam 22 may heat locally the semiconductor chip 70 . The solder bumps 80 are melted by thermal energy of the laser beam 22 . The semiconductor chip 70 may be removed from the board 60 by the picker 34 . The effective area of the laser beam 22 relative to the board 60 and/or the semiconductor chip 70 may include first exposure area 24 and/or second exposure area 26 .
The board 60 may be exposed to the laser beam 22 . A board 60 may not be damaged by the laser beam 22 when the solder bumps 80 are melted. The board 60 may be widely heated by the laser beam 22 having smaller thermal energy density than when the laser beam 22 heats the semiconductor chip 70 . Also, the thermal damage of the board 60 is minimized when the solder pillars 82 are melted by laser beam 22 .
Thus, the removal apparatus of semiconductor chip in accordance with some embodiment of the inventive concept may increase or maximize productivity and production yield.
The semiconductor chips 70 may be mounted on the board in a flip chip method. The semiconductor chips 70 may include a wafer level package. The semiconductor chips 70 may include a normal semiconductor chip such as a known good die and a failed semiconductor chip. Although not illustrated in the drawing, a failed semiconductor chip may include an index such as a marking or a bar code formed on a top surface thereof. The semiconductor chip 70 separated or removed from the board 60 may be a failed semiconductor chip. The board 60 may include a printed circuit board. The solder bumps 80 may electrically connect the board 60 to the semiconductor chips 70 . The solder bumps 80 may have a diameter of about 10 μm or less. The solder bumps 80 may be arrayed at intervals of several micrometers through several tens of micrometers. Although not illustrated in the drawing, an under fill may be disposed between the board 60 and the semiconductor chips 70 . The under fill may electrically insulate the solder bumps 80 . The under fill may fix the semiconductor chips 70 on the board 60 .
The semiconductor chip 70 may be heated by thermal energy of the laser beam 22 . The solder bumps 80 may be melted by heat transferred from the semiconductor chips 70 . The semiconductor chip 70 may be separated from the board 60 by a picker 34 after the solder bumps 80 are melted. The solder pillars 82 may include a part of the solder bumps 80 remaining on the board 60 after the semiconductor chip 70 is removed. The solder pillars 82 may be melted by thermal energy of the laser beam 22 .
A stage 10 may support the board 60 horizontally. The stage 10 may include a conveyor or a heat block moving the board 60 along a rail or a guide. The stage 10 may move or heat the board 60 depending on a control signal of control portion (not illustrated). A loader 92 may load the board 60 on the stage 10 . An unloader 94 may unload the board 60 from which all of the semiconductor chips 70 are removed. For example, the loader 92 and the unloader 94 may include a robot arm controlled by a control portion. The stage 10 may heat the board 60 to between, for example, about 200° C. and about 250° C., while moving the board 60 from under the loader 92 to under the laser 20 . A semiconductor chip recognition portion 96 may recognize an index on the semiconductor chip 70 . The semiconductor chip recognition portion 96 may include a camera or a bar code reader.
The picker 34 may suck the semiconductor chip 70 using a vacuum provided from a vacuum portion 30 . The picker 34 may make the laser beam 22 penetrate the semiconductor chip 70 . The picker 34 may include the lens 33 focusing the laser beam 22 . The lens 33 may focus the laser beam 22 on a second exposure area 26 of the semiconductor chip 70 . The picker 34 may have an open hole 31 having a diameter smaller than the lens 33 . The semiconductor chip 70 may be drawn onto the open hole 31 by a vacuum of the vacuum portion 30 . Thus, the laser beam 22 penetrating the lens 33 may enter the semiconductor chip 70 through the open hole 31 . A drive portion 32 may move the picker 34 from side to side, upward and downward depending on a control signal of the control portion. The picker 34 may be moved around the board 60 by the drive portion 32 when the solder bumps 80 are melted. Thus, the semiconductor chip 70 may be detached from the board 60 . The drive portion 32 may move the picker 34 , an intake 36 , and an air knife 38 around the stage 10 .
The vacuum portion 30 may provide a vacuum to the picker 34 and the intake 36 . The vacuum portion 30 may include a pump. The picker 34 and the intake 36 may be connected to the vacuum portion 30 through tubes (not illustrated). The tubes are disposed between the vacuum portion 30 and the picker 34 and between the vacuum portion 30 and the intake 36 through the drive portion 32 . The vacuum portion 30 may provide vacuums having different magnitudes to the picker 34 and the intake 36 . The intake 36 may suck or remove the melted solder pillars 82 using the laser beam 22 . The air knife 38 may blow an air 37 heated to a high temperature to the board 60 . The air 37 heated to a high temperature may shorten a melting time of the solder pillars 82 . An air blowing portion 35 may provide an air having pressure higher than atmospheric pressure to the air knife 38 . The air knife 38 and the intake 36 may move around the board while maintaining a specific distance.
The laser 20 may generate the laser beam 22 having a thermal energy in inverse proportion to a wavelength. For example, the laser 20 may generate the laser beam 22 having a single wavelength between, for example, about 808 nm and 1064 nm. The laser 20 may let the laser beam 22 enter the semiconductor chip 70 and the board 60 successively. The laser beam 22 may enter the board 60 of a first exposure area 24 . The first exposure area 24 may correspond to an irradiation area of the laser beam 22 . The first exposure area 24 may be greater than a planar area of the semiconductor chips 70 . For example, the first exposure area 24 may have a line width greater than a diagonal of the semiconductor chip 70 having a rectangular shape. The laser beam 22 may be focused by the lens 33 of the picker 34 . The focused laser beam 22 may enter a second exposure area 26 of the semiconductor chip 70 . The second exposure area 26 may be smaller than the first exposure area 24 . The second exposure area 26 may be smaller than the total planar area of the semiconductor chips 70 .
The laser beam 22 may have a same thermal energy and a different thermal energy density with respect to the first exposure area 24 and the second exposure area 26 . That is, the laser beam 22 entering the semiconductor chip 70 and the solder pillars 82 may have a different thermal energy from each other. The laser beam 22 may have a relatively high thermal energy density in the second exposure area 26 as compared with in the first exposure area 24 . The laser beam 22 having a high thermal energy density may intensively and rapidly heat the semiconductor chip 70 in the second exposure area 26 when melting the solder bumps 80 . The laser beam 22 having a relatively low thermal energy density may heat the solder pillars 82 and the board 60 in the first exposure area 24 . The solder pillars 82 of the first exposure area 24 may be melted by a thermal energy of the laser beam 22 . A high temperature air blown by the air knife 38 may accelerate melting of the solder pillars 82 . Damage of the board due to the laser beam 22 may be minimized because a thermal energy density of the laser beam 22 is low. The laser beam 22 may successively enter the semiconductor chip 70 and the solder pillars 82 . Thus a removal apparatus of semiconductor chip in accordance with some embodiments of the inventive concept may shorten a time of removing the semiconductor chip 70 and the solder pillars 82 .
FIG. 6 is a cross-sectional view illustrating a laser and a coining unit illustrated in FIG. 1 .
Referring to FIGS. 1 and 6 , a removal apparatus of semiconductor chip in accordance with some embodiments of the inventive concept may include a coining plate 52 compressing the solder pillars 82 into the board 60 . The coining plate 52 may be moved between the laser 20 and the solder pillars 82 by the drive portion 32 . The drive portion 32 may move the coining plate 52 upwardly and downwardly near the board 60 . The coining plate 52 may be heated by the laser beam 22 . The coining plate 52 may increase a surface area of the solder pillar 82 in the first exposure area 24 . When a surface area of the solder pillars 82 becomes wide, the solder pillars 82 may rapidly be melted by the laser beam 22 .
FIG. 7 is a cross-sectional view illustrating a laser and a flux nozzle illustrated in FIG. 1 .
Referring to FIGS. 1 and 7 , a flux 53 may accelerate melting of the solder pillars 82 by the laser beam 22 . The flux 53 may be spread on the solder pillars 82 by a nozzle 54 from flux provider 36 via drive portion 32 . The nozzle 54 may be moved around the stage 10 by the drive portion 32 . The flux 53 may cover a part or an entire part of the first exposure area 24 of the board 60 . The flux 53 may be heated by obtaining a thermal energy from the laser beam 22 of the first exposure area 24 . The flux 53 may increase a thermal energy transfer of the laser beam 22 to the solder pillars 82 . The flux 53 may help the solder pillars 82 to be heated by the laser beam 22 . The flux 53 can minimize damage of the board 60 when the solder pillars 82 are melted.
Thus, the removal apparatus of semiconductor chip in accordance with some embodiment of the inventive concept may increase or maximize productivity and production yield.
A method of driving a removal apparatus of semiconductor chip is described below.
FIG. 8 is a flow chart illustrating a method of removing a semiconductor chip in accordance with some example embodiments.
Referring to FIGS. 1 and 8 , a loader 92 loads the board 60 on the stage 10 (S 10 ). At least one failed semiconductor chip 70 is mounted on the board 60 . The semiconductor chip 70 may include a wafer level package and may be mounted on the board 60 in a flip chip method. The semiconductor chip 70 may have an index (not illustrated) judged to be faulty in an installation test. The stage 10 may move the board 60 under a semiconductor chip recognition portion 96 .
The semiconductor chip recognition portion 96 recognizes the semiconductor chip 70 on the board 60 (S 20 ). The semiconductor chip recognition portion 96 may detect an index on the semiconductor chip 70 . The semiconductor chip recognition portion 96 may include a camera obtaining an image of the semiconductor chip 70 and a bar code reader scanning a top surface of the board 60 .
The stage 10 moves the semiconductor chip 70 under the laser 20 (S 30 ). The drive portion 32 move the picker 34 between the laser 20 and the semiconductor chip 70 . The lens 33 of the picker 34 may be disposed between the laser 20 and the semiconductor chip 70 .
After that, the laser 20 irradiates the laser beam 22 into the semiconductor chip 70 to melt the solder bump 80 (S 40 ). The laser beam 22 may be focused on the semiconductor chip 70 in the lens 33 of the picker 34 to enter the second exposure area 26 of the semiconductor chip 70 . The semiconductor chip 70 may be locally heated by the laser beam 22 . Also, the solder bumps 80 may be melted by obtaining a thermal energy from the semiconductor chip 70 .
The picker 34 separates the semiconductor chip 70 from the board 60 (S 50 ). The picker 34 may draw the semiconductor chip 70 using a vacuum provided from the vacuum portion 30 . The drive portion 32 may move the picker 34 upwardly and downwardly. The picker 34 may separate or remove the semiconductor chip 70 from the board within two seconds after the laser beam 22 is irradiated.
The laser 20 irradiates the laser beam 22 into the first exposure area 24 of the board 60 successively until the solder pillars 82 are melted (S 60 ). The air knife 38 may blow a high temperature air to the solder pillar 82 . The high temperature air may shorten a melting time of the solder pillars 82 . The coining plate 52 may compress the solder pillars 82 . The coining plate 52 may be heated by a thermal energy of the laser beam 22 . The coining plate 52 may compress the solder pillars 82 to increase a surface area of the solder pillar 82 . The solder pillars 82 may be rapidly melted by obtaining a thermal energy of the laser beam 22 in proportion to a surface area of the solder pillar 82 . The nozzle 54 may spread the flux 53 on the solder pillars 82 . The flux 53 may effectively transfer a thermal energy of the laser beam 22 entering the first exposure area 24 to the solder pillars 82 .
Thus, the method of removing a removal apparatus of semiconductor chip in accordance with some embodiment of the inventive concept may increase or maximize productivity and production yield.
The intake 36 removes the melted solder pillar 82 (S 70 ). The intake 36 may remove the solder pillars 82 from the board 60 within five seconds after the semiconductor chip 70 is removed.
An unloader 94 unloads the board 60 from the stage 10 (S 80 ).
Thus, the method of removing a semiconductor chip in accordance with some embodiments of the inventive concept may minimize damage of the board 60 while irradiating the laser beam 22 into the semiconductor chip 70 and the solder pillars 82 successively.
As described above, when separating a semiconductor chip from a board, a thermal damage of the board may be minimized by focusing a laser beam on the semiconductor chip. Also, even after separating the semiconductor chip from the board, the laser beam may be continuously irradiated to melt solder pillars remaining on the board. Thus, a removal apparatus of semiconductor chip and a method of removing a semiconductor chip in accordance with some embodiments of the inventive concept may maximize or increase productivity and production yield.
While example embodiments have been particularly shown and described, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims. | A removal apparatus for a semiconductor chip may include a stage configured to support a board on which the semiconductor chip is mounted by bumps, a laser configured to irradiate a laser beam into the board over an area larger than the semiconductor chip, and a picker configured to cause the laser beam to penetrate the semiconductor chip locally and to separate the semiconductor chip from the board. A method of removing a semiconductor chip from a board may include loading the board, on which the semiconductor chip is mounted by bumps, on a stage; irradiating a laser beam into the semiconductor chip to melt the bumps and to separate the semiconductor chip from the board; continuously irradiating the laser beam into the board on which solder pillars, that are residues of the bumps, remain to melt the solder pillars; and removing the solder pillars. | 7 |
BACKGROUND OF THE INVENTION
[0001] This application claims the benefit of priority to U.S. Provisional Application Ser. No. 61/254,489, filed Oct. 23, 2009 which is incorporated herein by reference in its entirety. All references that may be cited in this specification, and their references, are incorporated by reference herein where appropriate for teachings of additional or alternative details, features, and/or technical background.
FIELD OF THE INVENTION
[0002] The present invention generally relates to a network based laboratory for performing comparative data analysis.
SUMMARY OF THE INVENTION
[0003] In embodiments there is presented a network based data laboratory configured as one or more servers on the INTERNET. The data laboratory comprises the tools required to perform comparative analysis of data from diverse data bases operated and maintained by various organizations and entities around the world and a user friendly graphical user interface (GUI) that facilitates structuring an inquiry necessary to perform a comparative analysis of data obtained from the diverse data bases and presenting the results of the analysis in graphical or tabular formats as specified by the user. The data laboratory maintains traceability of each of the data elements to its originating source.
[0004] In embodiments there is presented a computer system comprising: one or more interconnected servers comprising a graphical user interface subsystem, the servers connected to a communications network and operatively configured to: accept a data analysis inquiry from a user; determine and communicate with one or more remote sources of data pertinent to the data analysis inquiry; receive the pertinent data from the remote sources; convert the pertinent data to a predetermined format; perform analysis defined by the data analysis inquiry on the converted pertinent data; present results of the analysis by means of the graphical user interface subsystem.
[0005] There is further presented, in embodiments, a method of performing data analysis comprising: accepting a data analysis inquiry from a user; determining and communicating with one or more remote sources of data pertinent to the data analysis inquiry; receiving the pertinent data from the remote sources; converting the pertinent data to a predetermined format; performing analysis defined by the data analysis inquiry on the converted pertinent data; presenting results of the analysis by means of the graphical user interface subsystem.
BRIEF DESCRIPTION OF DRAWINGS
[0006] The accompanying figures incorporated in and forming a part of the specification illustrate several aspects of embodiments of the invention and, together with the description, serve to explain the embodiments.
[0007] FIG. 1 is a block diagram of an embodiment of a network based laboratory for data analysis.
[0008] FIG. 2 presents an embodiment of a web page that provides for user selection of language to be employed and the type of data analysis to be conducted.
[0009] FIG. 3 presents an embodiment of a web page that provides for user selection of sources of information to be included in the analysis.
[0010] FIG. 4 presents an embodiment of a web page that provides for user selection of geographical region-centric versus subject theme-centric.
[0011] FIG. 5 presents an embodiment of a web page that provides for user selection of subject theme.
[0012] FIG. 6 presents an embodiment of a web page that provides for user selection of specific aspects of the chosen subject theme.
[0013] FIG. 7 presents an embodiment of a web page that provides for user selection of countries or regions to be considered in the analysis.
[0014] FIG. 8 presents an embodiment of a web page that allows access to additional information on the selected counties.
[0015] FIG. 9 presents an embodiment of a web page that allows access to information on a country by country basis.
[0016] FIG. 10 presents an embodiment of a web page that allows selection of the output format.
[0017] FIG. 11 presents an embodiment of a web page illustrating data presented in a “bar chart ” format.
[0018] FIG. 12 presents an embodiment of a web page wherein additional countries may be included in the analysis.
[0019] FIG. 13 presents an embodiment of a web page that presents additional pertinent data.
DETAILED DESCRIPTION OF THE INVENTION
[0020] In embodiments there is presented a system for parametrically analyzing data and facts retrieved from a diverse plurality of information sources for the purpose of identifying relationships between the retrieved data sets. The parametric analysis of the retrieved data and facts may be controlled by the user in near real time thus providing an interactive “laboratory” for studying relationships. The information sources may be accessed by means of communication networks such as the INTERNET, or by other media such as, for example, CDs or DVDs, data stored in electronic memories, printed publication converted to electronic format, data generated by extraction from near real-time sources such as video or still cameras, keyboards, speech recognition systems, etc. Traceability of the source of each fact is maintained throughout the analysis and output presentation process.
[0021] The system comprises an input/output graphical user interface (GUI) subsystem, a data acquisition subsystem, and a data processing subsystem. This specification comprises the GUI and the conversion of data formats into a common “standard” format which permits relational analysis. This conversion of data formats is also referred to as “production of variables.”
[0022] In an embodiment of the data laboratory, shown in FIG. 1 , one or more servers 10 may comprise a data processing subsystem 55 , a data acquisition subsystem 60 and graphical user interface subsystem (GUI) 65 , for communicating, converting, and presenting data sought after by the user. A user interfaces with the data laboratory via a client 70 , which could be any form of portal unto which the user may gain access to the INTERNET. Examples of portals may be a server, desktop computer, laptop, mobile telephone, electronic book reader (such as the iphone or ipad), voice only interfaces may also be used with voice to text or voice to data to build the necessary query, sought by the user. Other devices providing users having vision or hearing impairments can also be used to gain access to the INTERNET and the data retrieval system.
[0023] An embodiment of client 70 accesses the data retrieval servers over communication channels 40 , 44 via the INTERNET to interface with the GUI subsystem 65 which respond to a users request seeking data. The GUI subsystem, builds a questionnaire to form a query hierarchy. The question posed by the system and responded to by the user are formed from predetermined knowledge. Some or all of the data formation constraints can be formed from knowledge gained from data previously ascertained from one or more data sources 75 or other external sources. Data sources may be INTERNET websites, data center repositories, free or paid databases, portable electronic or optical media or other known or yet formed sources of data.
[0024] The GUI subsystem 65 , is connected via a bidirectional communication pathway 30 , 35 with data acquisition 60 and also a bidirectional communication pathway 25 , 50 with data processing subsystem 55 . The data acquisition subsystem 65 is also connected via a bidirectional communication pathway 15 , 20 with the data processing subsystem 60 and a bidirectional communication pathway 46 , and 42 via the INTERNET 80 with data sources 75 . Communications from the GUI subsystem 65 travel back to the user via the same communication channels 40 , 44 . The communication pathways represented herein may be formed by hardwire connections such a via Ethernet, or via wireless measures such as 802.11 standards or broadband via a communication service provider. Alternative communication pathway configurations are also envisioned such as having different pathways for incoming and outgoing data, such as the client sending request via broadband and receiving results via a wired connection pathway.
[0025] The GUI permits the user to input a query defining the topic area and the variables to be studied. The configuration of the GUI permits the user to provide the necessary topics and ranges of parameters by means of a hierarchal sequence of question screens which are configured, in an embodiment, to accept multiple choice responses. Other input modes such as keyboard entered text, computer mouse responses, voice recognition and video inputs may also be accommodated. The GUI is designed for remote INTERNET access to the data laboratory system.
[0026] An embodiment of the GUI is presented by FIGS. 2 through 13 . FIG. 2 is a design for a graphics display screen that provides for user selection of the language to be employed and the type of data analysis to be addressed in the session. FIG. 3 allows the user to select the sources of information to be included in the analysis. FIG. 4 is a design for a graphics display screen that provides for user selection as to whether the study will be geographical region-centric or subject theme-centric. Assuming that subject theme is selected, FIG. 5 is a design for a graphics display screen that provides for user selections of subject theme. FIG. 6 is a design for a graphics display screen that provides for user selection(s) of the subject theme to be studied. If, alternatively, geographical region-centric had been chosen, FIG. 7 would appear, which is a design for a graphics display screen that provides for user selections of countries or regions to be considered in the analysis. FIG. 8 provides links to INTERNET web pages where the user can obtain information on a country by country basis. FIG. 9 next appears which allows the user to access information on a country by country basis. FIG. 10 illustrates the presentation of output data in a “Map” format while FIG. 11 illustrates the presentation of output data in a “bar chart” format. FIG. 12 . is a design for a graphics display screen that allows the user to add additional countries to the initially specified set. FIG. 13 is a design for a graphics display screen that presents additional pertinent data related to the analysis.
[0027] Having received the query parameters from the user input, the data processing system retrieves the necessary data and facts and transforms data and facts into the common format to be used. The production of the variables may comprise five steps:
[0028] 1. Find the relevant variable value.
[0029] Relevant variable value can be either on the INTERNET, CD/DVD or in print(paper). The material available on the INTERNET is usually available only as a PDF file, Excel file or other proprietary format. A prerequisite requirement for handling a variable value is that it is collected and reported in accordance with the minimum statistical segment of the data laboratory. In this case, there must be a value for each of the countries of the world, and there must be values specified for the majority of the countries. To produce a variable to the data laboratory where the number of countries with variable value is set below 40% is seldom interesting.
[0030] 2. Enter the variable value in the current regime.
[0031] The variable value specified in the database file should be in the order of the countries of the world.
[0032] 3. “ASCII wash” of variable values
[0033] The obtained variable value must be filtered to remove any special characters by a method referred to as “ASCII-washing.” The collected variable value is stored and then retrieved from the Notepad program. Notepad does not handle special characters and therefore strips them from the variable.
[0034] 4. Define and specify variable names
[0035] In the database file, the name of the variable is shown on line 1. This name appears in the data laboratory when searching for a variable to work with. The name should be descriptive not be not too long.
[0036] 5. Enter the definition and any footnotes.
[0037] On the second line of the database is the variable collectors official name of the variable. This may differ from the name entered on line 1, especially if it is too long or otherwise unsuitable as a variable name. The name is followed by the definition of the variable. This definition should be the same as that provided by the original collector of the data. The definition is followed by the source reference and may also be supplemented by a clickable web address of the original collector. Finally, any footnotes provided by the original collector may be added. FIG. 10 is an illustrative example of a variable.
STATEMENT REGARDING PREFERRED EMBODIMENTS
[0038] While the invention has been described with respect to preferred embodiments, those skilled in the art will readily appreciate that various changes and/or modifications can be made to the invention without departing from the spirit or scope of the invention as defined by the appended claims. All documents cited herein are incorporated by reference herein where appropriate for teachings of additional or alternative details, features and/or technical background. | A network based laboratory for data analysis is presented. The laboratory permits a user to submit an inquiry specifying the analysis to be performed, the sources of the data to be analyzed and the output format for the analysis results. | 6 |
[0001] The present application claims the benefit of (i) U.S. Provisional Application No. 60/902,762, filed Feb. 22, 2007, (ii) U.S. Provisional Application No. 60/904,468, filed Mar. 2, 2007, and (iii) U.S. Provisional Application No. 60/904,593, filed Mar. 2, 2007, all of which are hereby incorporated by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to vitamin C preparations having enhanced bioavailability.
BACKGROUND OF THE INVENTION
[0003] According to the National Institute of Health and the Food and Nutritional Board of the National Academy of Science, vitamin C is an essential nutrient involved in many biological functions. Vitamin C can only be acquired through diet (i.e., food or nutritional supplement).
[0004] Vitamin C has been implicated as an important dietary component as it is required for physiological and metabolic activities including the development of healthy neurons (Zhou et al., 2003; Weeks & Perez, 2007), prevention of neurodegenerative diseases (Boothby & Doering, 2005; Landmark 2006), wound healing (Kaplan et al., 2004; Marionnet C et al., 2006; Weeks & Perez, 2007), and the maintenance of a healthy immune system (Fay et al., 1994; Lehr et al., 1994; Weeks & Perez, 2007).
[0005] Given the importance of vitamin C, the bioavailability of vitamin C has been the focus of intense research. An improvement in absorption and retention of vitamin C in blood plasma or tissue would increase the beneficial effects of vitamin C. Thus, there is a continuing need for vitamin C preparations having enhanced bioavailability.
SUMMARY OF THE INVENTION
[0006] The present invention relates to vitamin C preparations which enhance absorption of vitamin C into cells, and prolong the retention of vitamin C within the blood plasma and tissue of mammals, such as humans. The vitamin C preparations of the present invention include lipophilic molecules which improve the absorption of vitamin C resulting in higher plasma and cellular levels.
[0007] One embodiment of the invention is a vitamin C preparation comprising:
(a) at least about 90% by weight of vitamin C, (b) at least about 0.1% by weight of lipophilic molecules comprising (i) one or more saturated straight C 30 -C 34 fatty alcohols, (ii) one or more unsaturated ω-9 C 18 -C 24 fatty acids, (iii) optionally one or more saturated straight C 14 -C 20 fatty acids, (iv) optionally one or more unsaturated ω-3 C 16 -C 24 fatty acids, and (v) optionally one or more unsaturated ω-6 C 18 -C 22 fatty acids; and (c) optionally at least about 0.1% by weight of bioflavonoids,
based upon 100% total weight of the vitamin C preparation. The preparation preferably comprises at least 0.1% by weight of component (b)(i) (e.g., about 0.5 to about 4% by weight of component (b)(i)), and at least 0.01% by weight of component (b)(ii), and when the preparation includes one or more of components (b)(iii)-(b)(v), each included component is present in an amount of at least 0.01% by weight. The vitamin C preparation is preferably in the form of an oral dosage form, such as a tablet or capsule.
[0011] Preferably, the amount of the lipophilic molecules in the vitamin C preparation ranges from 0.1 or 0.2 to 5% by weight, based upon the total weight of the preparation. According to one preferred embodiment, the vitamin C preparation contains about 0.8 to about 1.8% by weight of the lipophilic molecules and even more desirably about 1 to about 1.5% by weight of the lipophilic molecules.
[0012] The vitamin C preparation can be administered to a person to (i) promote a healthy nervous system, (ii) prevent or decrease the risk of developing a neurodegenerative disease, (iii) enhance NGF-mediated neurite outgrowth, (iv) promote wound healing, (v) enhance fibroblast adhesion to and the interaction with the extracellular matrix, (vi) protect the immune system from xenobiotics, (vii) decrease the risk of developing an oxidative pathogenesis, and (viii) decrease the risk of developing cancer, cardiovascular diseases, atherosclerosis, and other age-related diseases associated with cytotoxic, genotoxic, and proinflammatory mechanisms. According to one embodiment, the method includes:
[0013] (a) recognizing the vitamin C preparation as being effective for one of the aforementioned purposes (e.g., to promote a healthy nervous system) and optionally that the person is in need thereof, and
[0014] (b) after such recognition, orally administering to the human an effective amount of the vitamin C preparation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a graph of the concentration of vitamin C in H9 human T-cells as measured 15-120 minutes following administration of the vitamin C preparation of Example 1 (PWC), ascorbic acid (AA), calcium ascorbate (CaA), or calcium ascorbate-calcium threonate-dehydroascorbate (Ester-C) (commercially available as Ester-C® from Nature's Value of Coram, N.Y.) (Ester-C®).
[0016] FIG. 2 is a graph of the percentage inhibition of 1,1-diphenyl-2-picryl hydrazyl (DPPH) reduction as measured by the procedure described in Example 4 following administration of 1, 2.5, 5, 10, or 20 μg/ml of the vitamin C preparation of Example 1.
[0017] FIG. 3 is a graph of the percentage of cells exhibiting neurite outgrowth over 24 hours following administration of vehicle (-) or 0.5 μM of the vitamin C preparation of Example 1 (PWC), ascorbic acid (AA), calcium ascorbate (CaA), or calcium ascorbate-calcium threonate-dehydroascorbate (EsterC) or a control, as measured by the procedure described in Example 5.
[0018] FIG. 4 is a graph showing the percentage of fibroblasts adhered to fibronectin substrates following administration of vehicle (-) or 50 μM of the vitamin C preparation of Example 1 (PWC), ascorbic acid (AA), calcium ascorbate (CaA), or calcium ascorbate-calcium threonate-dehydroascorbate (EsterC) or a control as measured by the procedure described in Example 6.
DETAILED DESCRIPTION OF THE INVENTION
Definitions
[0019] The term “vitamin C,” unless otherwise stated, refers to ascorbic acid and pharmaceutically acceptable salts thereof, including, but not limited to, mineral salts of ascorbic acid, effervescent vitamin C (e.g., a combination of ascorbic acid, citric acid and sodium bicarbonate), chelates of ascorbic acid, and alkaline salts of ascorbic acid.
Lipophilic Molecules
[0020] Suitable lipophilic molecules include, but are not limited to, those derived from natural waxes such as, but is not limited to, sugar cane wax, rice bran wax, carnauba wax, candelilla wax, japan wax, ouricury wax, bayberry wax, shellac wax, sunflower wax, orange wax, and beeswax. According to one preferred embodiment, the lipophilic molecules are derived from rice bran wax, carauba wax, cadelilla wax, and beeswax. According to a more preferred embodiment, the lipophilic molecules are derived from rice bran wax. Suitable lipophilic molecules extracted from natural waxes include, but are not limited to, palmitic acid, linoleic acid, linolenic acid, oleic acid, and steric acid.
[0021] According to one preferred embodiment, the vitamin C preparation includes one or more or all of the following lipophilic molecules at the recited weight ratios:
[0022] about 0.1-3.0 units (by weight) palmitic acid,
[0023] about 0.1-20.0 units linoleic acid,
[0024] about 0.1-6.0 units alpha linolenic acid,
[0025] about 0.1-4.0 units oleic acid,
[0026] about 0.1-8.0 units steric acid,
[0027] about 0.1-0.9 units arachidic acid,
[0028] about 0.1-0.9 units heneicosanoic acid,
[0029] about 1.0-9.0 units behenic acid,
[0030] about 1.0-9.0 units tricosanoic acid,
[0031] about 0.1-9.0 units lignoceric acid,
[0032] about 0.5-9.0 units cerotic acid,
[0033] about 1.0-10.0 units heptacosanoic acid,
[0034] about 0.5-15.0 units montanic acid,
[0035] about 2.0-26.0 units melissic acid,
[0036] about 0.5-16.0 units docosahexaenoic acid,
[0037] about 0.5-9.0 units docosapentaenoic acid,
[0038] about 0.5-19.0 units docosatetraenoic acid,
[0039] about 0.5-9.0 units docosadienoic acid,
[0040] about 0.1-18.0 units erucic acid,
[0041] about 0.1-0.9 units nervonic acid,
[0042] about 0.1-80.0 units cetyl alcohol-hexadecanol-palmityl alcohol,
[0043] about 0.1-50.0 units 1-heptadecanol,
[0044] about 0.1-10.0 units 1-eicosanol-arachidyl alcohol,
[0045] about 0.1-30.0 units 1-docosanol-behenyl alcohol,
[0046] about 10.0-150.0 units lignoceryl alcohol-1-tetracosanol,
[0047] about 10.0-120.0 units 1-hexacosanol-ceryl alcohol,
[0048] about 0.1-20.0 units 1-heptacosanol,
[0049] about 5.0-200.0 units 1-octacosanol,
[0050] about 150.0-400.0 units 1-triacontanol-melissyl alcohol,
[0051] about 100.0-200.0 units dotriacontanol, and
[0052] about 50.0-150.0 units tetratriacontanol.
[0000] In one embodiment, the vitamin C preparation includes one or more or all of the following lipophilic molecules at the recited weight percentages:
[0053] about 0.01-0.3% (by weight) palmitic acid,
[0054] about 0.01-2.0% linoleic acid,
[0055] about 0.01-0.6% alpha linolenic acid,
[0056] about 0.01-0.4% oleic acid,
[0057] about 0.1-0.8% steric acid,
[0058] about 0.01-0.09% arachidic acid,
[0059] about 0.01-0.09% heneicosanoic acid,
[0060] about 0.1-0.9% behenic acid,
[0061] about 0.1-0.9% tricosanoic acid,
[0062] about 0.01-0.9% lignoceric acid,
[0063] about 0.05-0.9% cerotic acid,
[0064] about 0.1-1.0% heptacosanoic acid,
[0065] about 0.05-1.5% montanic acid,
[0066] about 0.2-2.6% melissic acid,
[0067] about 0.05-1.6% docosahexaenoic acid,
[0068] about 0.05-0.9% docosapentaenoic acid,
[0069] about 0.05-1.9% docosatetraenoic acid,
[0070] about 0.05-0.9% docosadienoic acid,
[0071] about 0.01-1.8% erucic acid,
[0072] about 0.01-0.09% nervonic acid,
[0073] about 0.01-8.0% cetyl alcohol-hexadecanol-palmityl alcohol,
[0074] about 0.01-5.0% 1-heptadecanol,
[0075] about 0.01-1.0% 1-eicosanol-arachidyl alcohol,
[0076] about 0.01-3.0% 1-docosanol-behenyl alcohol,
[0077] about 1.0-15.0% lignoceryl alcohol-1-tetracosanol,
[0078] about 1.0-12.0% 1-hexacosanol-ceryl alcohol,
[0079] about 0.01-2.0% 1-heptacosanol,
[0080] about 0.5-20.0% 1-octacosanol,
[0081] about 15.0-40.0% 1-triacontanol-melissyl alcohol,
[0082] about 10.0-20.0% dotriacontanol, and
[0083] about 5.0-15.0% tetratriacontanol, based upon 100% total weight of the lipophilic molecules in the vitamin C preparation.
[0084] The mixture of lipophilic molecules can be obtained by (1) saponification of a wax (e.g., a natural wax), (2) solidifying and grinding the saponified wax to a d 90 less than 2000 microns (e.g., 100-500 microns or 500-2000 microns), (3) extracting the ground material with acetone or an alcohol (e.g., ethanol or isopropanol), and (4) optionally solidifying and grinding the extracted material to a d 90 less than 2000 microns (e.g., 100-500 microns or 500-2000 microns).
[0085] The natural waxes undergo saponification or hydrolysis before the extraction procedure. For saponification, the natural waxes are heated using a jacketed kettle at 90° C. for 3 hours until the wax was completely melted, KOH is added, and the mixture is held at 90° C. for 1 hour with stirring. For hydrolysis, the natural waxes are heated using a jacketed kettle at 90° C. for 3 hours until the wax was completely melted, sulfuric acid aqueous solution is added, and mixture is held at 90° C. for 1 hour with stirring. After 1 hour of stirring the saponified or hydrolyzed wax is poured into cart trays and dried at 21.1° C. before undergoing the extraction procedure.
[0086] The extraction of the natural waxes may be performed by either dispersed-solids extraction or immersion type percolation extraction. For the dispersed-solids extraction, the natural waxes are ground to a particle mesh size of 100 to 425 microns and subjected to liquid extraction in a dispersed-solids extraction system. In the case of immersion type percolation extraction, the natural waxes are ground to a particle mesh size of 500 to 2000 microns and subjected to liquid extraction in a solid-liquid immersion type percolating extractor system. In both types of extraction equipment, the natural mixture of aliphatic alcohols, saturated fatty acids, and omega-3, omega-6, omega-9 fatty acids is selectively extracted with adequate hot organic solvents such as acetone and ethanol with a temperature range of 55° C. to 75° C. The extractions are purified with hot organic solvents such as hexane, heptane, and acetone; recovered; and dried. The extractions contain a mixture of aliphatic alcohols having 17 to 34 carbon atoms, saturated fatty acids having 16 to 30 saturated carbon atoms, and omega-3, omega-6, omega-9 fatty acids with melting point between 70 and 80° C. The ratio of the natural wax particles to hot liquid extractants is from 1 to 4 and 1 to 10. According to one preferred embodiment, the extractions with hot organic solvents at 60° C., and the ratio of natural wax particles to hot liquid extractants is 1 to 8.
Bioflavonoids
[0087] Suitable bioflavonoids include, but are not limited to, rutin, naringin, hesperidin, neohesperidin, neohesperidin dihydrochalcone, naringenin, hersperitin, nomilin, and gallic acid. According to one preferred embodiment, the vitamin C preparation contains hesperidin, gallic acid, and optionally other bioflavonoids.
[0088] According to one preferred embodiment, the vitamin C preparation includes one or more or all of the following bioflavonoids at the recited weight ratios:
[0089] about 20-120 units (by weight) rutin,
[0090] about 25-100 units naringin,
[0091] about 7000-20000 units hesperidin,
[0092] about 5-100 units neohesperidin,
[0093] about 10-100 units neohesperidin dihydrochalcone,
[0094] about 5-100 units naringenin,
[0095] about 5-100 units hersperitin,
[0096] about 50-150 units nomilin, and
[0097] about 120,000-1,000,000 units gallic acid.
[0000] In one embodiment, the vitamin C preparation includes one or more or all of the following bioflavonoids at the recited weight percentages:
[0098] about 20-120 ppm rutin,
[0099] about 25-100 ppm naringin,
[0100] about 7000-20000 ppm hesperidin,
[0101] about 5-100 ppm neohesperidin,
[0102] about 10-100 ppm neohesperidin dihydrochalcone,
[0103] about 5-100 ppm naringenin,
[0104] about 5-100 ppm hersperitin,
[0105] about 50-150 ppm nomilin, and
[0106] about 120-1000 mg/g gallic acid,
[0000] based on 1 g of the bioflavonoid mixture.
[0107] According to one embodiment, the vitamin C preparation includes vitamin C and the lipophilic molecules at a weight ratio ranging from about 1000:1 to about 10:1. According to a preferred embodiment, the weight ratio ranges from about 100:1 to about 8:1.
[0108] According to a preferred embodiment, the vitamin C preparation includes at least about 90% by weight of vitamin C and about 0.1% by weight of the lipophilic molecules based upon 100% total weight of the vitamin C preparation. More preferably, the vitamin C preparation includes from about 90 to about 99% by weight of vitamin C and from about 1 to about 8% by weight of lipophilic molecules. According to another embodiment, the vitamin C preparation includes from about 90 to about 98% by weight of vitamin C and from about 2 to about 7% (e.g., about 5%) by weight of lipophilic molecules.
[0109] According to a preferred embodiment, the vitamin C preparation includes at least about 90% by weight of vitamin C, from about 0.1 to about 9% by weight of lipophilic molecules, and from about 0.1 to about 5% by weight of bioflavonoids.
[0110] According to another embodiment, the vitamin C preparation includes about 200 to 40,000 IU vitamin C.
Dosage Forms
[0111] The vitamin C preparation is preferably in the form of an oral dosage form, such as beads, pellets, granules, capsules (soft or hard), sachets, tablets, powders, dispersible powders capable of effervescing upon addition of water, aqueous or oily suspensions, emulsions, syrups, elixirs, or lozenges. For example, the oral dosage form can be an chewable tablet or gum, oral liquid dosage form, such as a suspension in an aqueous or non-aqueous liquid solution, or an emulsion which can be a soft drink, tea, milk, coffee, juice, sports drink, or water. The vitamin C preparation can also be incorporated into various products, such as nutritional supplements (including vitamins and multi-vitamins), foods (including health food products such as nutrition bars), and drinks (including fruit juices such as energy drinks).
[0112] Generally, the daily dosage of the vitamin C preparation on a vitamin C weight basis can range from 30 mg to 2 g. For instance, the daily dosage can be 60 mg to 1 g or 60 mg to 500 mg. Desirably, the daily dosage ranges from 60 mg to 500 mg (e.g., the daily dosage can be 400 mg). According to one preferred embodiment, the daily dosage ranges from 60 mg to 200 mg (e.g., the daily dosage can be 60, 100, or 200 mg). The daily dose can be achieved by administration of a single dosage form of the invention or alternatively, two or more such dosage forms. Preferably, the daily dose is achieved by administration of only one or two dosage forms (e.g., once daily dosing or b.i.d.). Therefore, the present invention includes, but is not limited to, dosage forms containing 30, 60, 100, 200, 400, 500, or 1000 mg of the vitamin C preparation (on a vitamin C weight basis).
[0113] The vitamin C preparation may include one or more excipients or additives. Suitable excipients and additives include, but are not limited to, additional antioxidants (e.g., phenolic compounds), inert diluents (such as lactose, sodium carbonate, calcium phosphate, and calcium carbonates), granulating and disintegrating agents (such as corn starch and algenic acid), binders (such as starch), lubricants (such as magnesium stearate, stearic acid and talc), preservatives (such as ethyl or propyl p-hydroxybenzoate), colorants, flavoring agents, release modifying agents, thickeners, and any combination of any of the foregoing. Suitable antioxidants include, but are not limited to, bioflavonoids, flavonoids, flavonols, flavanones, flavones, flavonals, flavanolols, and flavanols.
[0114] Suitable inert solid diluents include, but are not limited to, calcium carbonate, calcium phosphate and kaolin. Suitable diluents for soft capsules include, but are not limited to, water and oils such as peanut oil, liquid paraffin, corn oil, wheat germ oil, soybean oil, and olive oil.
[0115] Aqueous suspensions or dispersions contain the vitamin C preparation, for example, in fine powder form together with one or more suspension or dispersion (or wetting) agents. Suitable suspension agents include, but are not limited to, sodium carboxymethylcellulose, methylcellulose, hydroxypropylmethylcellulose, sodium alginate, polyvinyl-pyrrolidone, gum tragacanth and gum acacia. Suitable dispersing or wetting agents include, but are not limited to, lecithin, condensation products of an alkylene oxide with fatty acids, condensation products of ethylene oxide with long chain aliphatic alcohols, condensation products of ethylene oxide with partial esters derived from fatty acids and a hexitol such as polyoxyethylene sorbitol monooleate, or condensation products of ethylene oxide with partial esters derived from fatty acids and hexitol anhydrides.
[0116] Dispersible powders and granules suitable for preparation of an aqueous suspension by the addition of water contain the vitamin C preparation, for example, together with a dispersing agent, wetting agent, or suspending agent. Suitable dispersing agents, wetting agents, and suspending agents include those mentioned above.
[0117] Oily suspensions may be formulated by suspending the vitamin C preparation in an oil, such as an vegetable oil or a mineral oil. The oily suspensions may also contain a thickening agent such as carnauba wax, candelilla wax, rice bran wax, beeswax, hard paraffin, or cetyl alcohol.
[0118] The vitamin C preparation may be in the form of an oil-in-water emulsion. The oily phase may be a vegetable based oil or a mineral based oil. Suitable emulsifying agents include, for example, naturally occurring gums such as acacia and tragacanth gum, naturally occurring phosphatides such as soy bean, lecithin, esters and partial esters derived from fatty acids and hexitol anhydrides and condensation products of partial esters with ethylene oxide, such as polyoxyethylene sorbitan monooleate.
[0119] Syrups and elixirs may be formulated with sweetening agents such as glycerol, propylene glycol, sorbitol, aspartame, or sucrose, and may also contain a demulcent, preservative, flavoring, or coloring agent.
[0120] The vitamin C preparation may be also in a form suitable for administration by inhalation (e.g., as a finely divided powder or a liquid aerosol), or for parenteral administration (e.g., as a sterile aqueous or oily solution for intravenous, subcutaneous, intramuscular dosing or as a suppository for rectal dosing). Administration of the vitamin C preparation by these non-oral routes avoids gastrointestinal side effects, which may accompany high doses of vitamin C released in the stomach.
[0121] The vitamin C preparation can also be delivered topically, for example, to protect the skin from free radicals, promote wound healing (for instance, for healing cuts, abrasions, sun damage (e.g., sun burn), wrinkles, and scars), and/or reduce inflammation. The vitamin C preparation of the invention provides superior penetration of vitamin C through the skin than vitamin C alone. Transdermal delivery of the vitamin C preparation permits systemic delivery of the vitamin C while avoiding gastrointestinal side effects. The topical formulation containing the vitamin C preparation can be in the form of a solution, suspension, lotion, emulsion, ointment, cream, or gel. According to a preferred embodiment, the topical formulation is a cream or lotion. The formulation may include additional active ingredients. These formulations may prepared by methods known in the art, and typically include a topically acceptable vehicle. One embodiment is a topical formulation containing about 0.5 to about 25% by weight of the vitamin C preparation of the present invention, based upon 100% total weight of the topical formulation. For instance, the topical formulation can contain 0.5-2%, 1-2%, 1-5%, 1-10%, 5-15%, 5-20%, or 10-20% by weight of the vitamin C preparation.
[0122] The vitamin C preparation could be used to coat a medical device that is then positioned to a desired target location within the body, whereupon the vitamin C preparation elutes from the medical device. Preferably, the coating includes a therapeutically effective amount of the vitamin C preparation. In one embodiment, the medical device is positioned so that the vitamin C preparation is released in a therapeutically effective amount to a targeted site such as a diseased or injured tissue or organ. The device can be introduced temporarily or permanently into a mammal (e.g., a human) for the prophylaxis or therapy of a medical condition, or to augment the immune system. The device can be introduced subcutaneously, percutaneously, or surgically. The medical device can be selected from stents, synthetic grafts, artificial heart valves, artificial hearts and fixtures to connect the prosthetic organ to the vasculature, venous valves, abdominal aortic aneurysm grafts, inferior venal caval filters, catheters including permanent drug infusing catheters, embolic coils, embolic materials used in vascular embolization mesh repair materials, a Dracon vascular particle orthopedic metallic plates, rods, screws, and vascular sutures.
[0123] The vitamin C preparation may be formulated to provide immediate release or controlled release (e.g., sustained release) of the vitamin C preparation, for example, to provide effective doses of vitamin C over extended periods of time to prolong the biological activity and beneficial biochemical functions of vitamin C. One embodiment of the invention is a controlled release dosage form (such as a solid dosage form) containing about 200 to 40,000 IU vitamin C, about 1 to 100 mg of lipophilic molecules, and 1 to 500 mg of bioflavanoids. For example, the controlled release dosage form may release about 10 to about 35% by weight of the total vitamin C preparation within about 2 hours in an in vitro dissolution test, and about 40 to about 70% by weight of the total vitamin C preparation within about 8 hours. According to another embodiment, the controlled release dosage form may release about 50% by weight of the total vitamin C preparation within about 2 hours in an in vitro dissolution test, and more than 90% by weight of the total vitamin C preparation within about 6 or 8 hours. Any type of controlled release system known in the art can be used. The in vitro dissolution test is conducted using the Basket Method (Apparatus 1) with 900 ml 0.1N HCl as the medium run at 100 RPM at a temperature of 37° C. The samples are filtered through Whatman filter paper #1 and the amount of vitamin C is calculated based on the equivalence to standard dicholorophenol-indophenol solutions.
[0124] Solid controlled release dosage forms (e.g., tablets) can be formulated (e.g., coated) so as to prolong the release of the vitamin C preparation into the gastrointestinal tract, or to prevent the release of the vitamin C preparation in the stomach in order to prevent or attenuate the gastrointestinal side effects which can accompany high doses of vitamin C released in the stomach. For example, the vitamin C preparation can be enteric coated so as to prevent significant release of the preparation in the stomach. Controlled release of the vitamin C preparation can prolong therapeutic and/or immunoprotective systemic concentrations of vitamin C in a person.
[0125] One embodiment of the invention is a three layer controlled release dosage form (e.g., a tablet) where each layer contains a vitamin C preparation of the invention. The vitamin C preparation of each layer can be the same or different. At least one of the layers provides controlled release of the vitamin C preparation. For example, the dosage form can include (i) a first layer, (ii) a second layer, and (ii) an outer layer surrounding the first and second layers, where the first layer and outer layer provide controlled release of the vitamin C preparation(s) and the second layer provides immediate release of the vitamin C preparation.
[0126] According to one preferred embodiment, the outer layer releases substantially all (>90%) of the vitamin C preparation in a controlled manner within 60, desirably 30, and even more desirably 20 minutes, as determined by the aforementioned in vitro dissolution test. The second layer provides immediate release of the vitamin C preparation contained therein. Finally, the first layer releases the vitamin C preparation contained therein in a controlled manner over at least 6 hours (e.g., substantially of the vitamin C preparation may be released within 6-10 hours or 6-8 hours), as determined by the aforementioned in vitro dissolution test.
[0127] Transdermal patch devices can also provide controlled administration (e.g., continuous or other sustained administration) of the vitamin C preparation. Methods for preparing controlled release transdermal formulations are known in the art. For example, the transdermal device may contain an impermeable backing layer which defines the outer surface of the device and a permeable skin attaching membrane, such as an adhesive layer, sealed to the outer layer in such a way as to create a reservoir between them wherein the therapeutic agent is placed (e.g., a bandage or patch (including a time released patch)).
[0128] Other suitable controlled release systems include, but are not limited to, long-term sustained implants, aqueous or oily suspensions, emulsions, syrups, elixirs, or lozenges, chewable tablet or gum, foods, beverages, osmotic systems, and dissolution system (e.g., effervescent oral dosage form).
[0129] The vitamin C preparation of the present invention is preferably administered orally to a mammal (e.g., a human), but it can also be administered by other routes of administration, such as intravenously or subcutaneously.
Preparation of Formulation
[0130] The vitamin C preparation of the present invention may be prepared by methods well known in the art, such as mixing the vitamin C, lipophilic molecules, optionally bioflavanoids, and any desired excipients.
[0131] The following examples illustrate the invention without limitation.
EXAMPLE 1
Lipid Metabolite Extraction:
[0132] Saponification: 25 kg of rice bran wax was heated using a jacketed kettle at 90° C. for 3 hours until the wax was completely melted. 4.67 L of 8.0 M KOH (450 g/l) in water was slowly added with continuous stirring and heating. The mixture was held at 90° C. for 1 hour with stirring. After 1 hour the saponified wax was poured into cart trays and dried at 21.1° C. The 32.1 kg of cooled dried saponified wax was then ground to a powder (100-425 or 500-2000 microns).
[0133] Extraction: 9.6 kg of the saponified wax was placed in 8 extraction thimbles (1.2 kg of saponified wax per extraction thimble). 100 L of acetone were pumped into a 200 L cylindrical-bottom flask and connected to a soxhlet system. The system was refluxed for approximately 24 hours, and the extract was pumped to a jacketed reactor. The extract was chilled to approximately 10° C. with 20 rpm agitation (20 rpm) for 10 hours. The chilled extract was then centrifuged in a vertical basket centrifuge. The collected solid was poured into trays and vacuum dried for 16 hours. The dried solid was then ground to a powder.
Preparation of the Vitamin C Preparation:
[0134] A jacketed mixer was charged with dry powder of 58 kg of vitamin C, 0.75 kg of the lipid metabolites prepared above and 1.5 kg of bioflavonoids (AnMar International Ltd; Bridgeport, Conn.). The mixer was then turned on (agitation is initiated—plows) to create a homogenous mixture of dry powder. The high speed shearing devices (choppers) were initiated for 1 minute. Hot water was then pumped through the jacket of the mixer to heat the mixture to 80° C. with continuous mixing (plows only) for 15 minutes for complete encapsulation. The encapsulated mixture was cooled by running chilled water (10° C.) through the jacket under continuous mixing for 1 hour until a free-flowing powder was formed. The powder was discharged into a double polyethylene-lined container and then passed through a comminuting mill running at approximately 2500 rpm equipped with a 0.15 mm screen. The milled powder was collected into appropriately labeled, double polyethylene-lined drums and reconciled.
[0000]
TABLE 1
The formulation of a of the invention is shown below:
Ingredients
Amount
Vitamin C
90-99%
Lipophilic Molecules
0.1-5%
palmitic acid
0.1-3.0
mg/g*
linoleic acid (ω-6 fatty acid)
0.1-20.0
mg/g
alpha linolenic acid (ω-3 fatty acid)
0.1-6.0
mg/g
oleic acid (ω-9 fatty acid)
0.1-4.0
mg/g
stearic acid
0.1-8.0
mg/g
arachidic acid
0.1-0.9
mg/g
heneicosanoic acid
0.1-0.9
mg/g
behenic acid
1.0-9.0
mg/g
tricosanoic acid
1.0-9.0
mg/g
lignoceric acid
0.1-9.0
mg/g
cerotic acid
0.5-9.0
mg/g
heptacosanoic acid
1.0-10.0
mg/g
montanic acid
0.5-15.0
mg/g
melissic acid
2.0-26.0
mg/g
Docosahexaenoic acid (DHA) (ω-3 fatty acid)
0.5-16.0
mg/g
docosapentaenoic acid (DPA) (ω-3 fatty acid)
0.5-9.0
mg/g
Docosatetraenoic acid (DTA) (ω-6 fatty acid)
0.5-19.0
mg/g
docosadienoic acid (ω-6 fatty acid)
0.5-9.0
mg/g
erucic acid (ω-9 fatty acid)
0.1-18.0
mg/g
nervonic acid (ω-9 fatty acid)
0.1-0.9
mg/g
cetyl alcohol-hexadecanol-palmityl alcohol
0.1-80.0
mg/g
1-heptadecanol
0.1-50.0
mg/g
1-eicosanol-arachidyl alcohol
0.1-10.0
mg/g
1-docosanol-behenyl alcohol
0.1-30.0
mg/g
lignoceryl alcohol-1-tetracosanol
10.0-150.0
mg/g
1-hexacosanol-ceryl alcohol
10.0-120.0
mg/g
1-heptacosanol
0.1-20.0
mg/g
1-octacosanol
5.0-200.0
mg/g
1-triacontanol-melissyl alcohol
150.0-400.0
mg/g
Dotriacontanol
100.0-200.0
mg/g
Tetratriacontanol
50.0-150.0
mg/g
Bioflavonoids (optional)
0.1-5%
Rutin
20-120
ppm**
Naringin
25-100
ppm
Hesperidin
7000-20000
ppm
Neohesperidin
5-100
ppm
neohesperidin dihydrochalcone
10-100
ppm
Naringenin
5-100
ppm
Hersperitin
5-100
ppm
Nomilin
50-150
ppm
gallic acid
At least 120 mg/g
(q.s.)
*mg/g = mg of component per g of total lipophilic molecules
**ppm or mg/g = ppm or mg of component per g of total bioflavonoid mixture
EXAMPLE 2
[0135] The rate of vitamin C absorption in H9 cells, a human T-cell line, was determined for the formulation of Example 1 and other vitamin C formulations.
[0136] Cells from the human T-lymphoblastic H9 cell line were starved of vitamin C for 18 hours in serum-free media and subsequently suspended in 50 μM of (1) ascorbic acid (AA), (2) calcium ascorbate (CaA), (3) calcium ascorbate-calcium threonate-dehydroascorbate (commercially available as Ester-C® from Nature's Value of Coram, N.Y.) (Ester-C®), or (4) the vitamin C preparation of Example 1 (PWC). At the times indicated in FIG. 1 , cells were harvested and measured for vitamin C and protein content. The cellular vitamin C levels of the cells were measured using the 2,4-dinitrophenylhydrazine spectrophotometric technique (Bessey et al., 1947).
[0137] Over a two hour period, the level of vitamin C uptake from Example 1 was consistently higher than that observed with ascorbic acid, calcium ascorbate, and calcium ascorbate-calcium threonate-dehydroascorbate (See FIG. 1 ). At fifteen minutes, cellular vitamin C levels ranged from 7±1.4 nmol/mg cellular protein with ascorbic acid, to over double that amount (15±2.4 nmol/mg protein) with the vitamin C preparation of Example 1. The absorbed vitamin C levels rose significantly with time, peaking at approximately two hours with cellular levels ranging from 31 nmol/mg protein for ascorbic acid and 50 nmol/mg protein for the vitamin C preparation of Example 1.
[0138] In order for vitamin C to exert its beneficial effects, it must be taken up into the cell. To date, vitamin-C lipid metabolites exhibits the greatest amount of vitamin C uptake and retention as compared to all other vitamin C formulations.
EXAMPLE 3
[0139] The ability to inhibit pesticide-induced T-lymphocyte aggregation was determined for the formulation of Example 1 and other vitamin C formulations.
[0140] The human T-lymphoblastic H9 cell line was incubated with vehicle (-) or with one of two activators of T-lymphocyte aggregation, phytohemagglutinin (PHA; 10 μm) or bifenthrin (10 mM). The cells were immediately treated with 0.5 μM of (1) ascorbic acid (AA), (2) calcium ascorbate (CaA), (3) calcium ascorbate-calcium threonate-dehydroascorbate (Ester-C®), or (4) the vitamin C preparation of Example 1 (PWC) for 30 minutes at 37° C. After treatment, the ability of each formulation to inhibit homotypic aggregation was measured by counting aggregate size at 400× magnification.
[0141] The vitamin C preparation of Example 1, inhibited the aggregation of the T-lymphocytes induced by the pesticide PHA or the pesticide bifenthrin by 88% and 84% respectively (Table 2). The reduction in T-lymphocyte aggregation was greater following treatment with the vitamin C preparation of Example 1 than any of the other formulations.
[0142] Leukocyte cell-cell adhesion is associated with xenobiotic induced hyperactivation and inflammatory damage, and vitamin C has been shown to prevent cigarette smoke-induced leukocyte aggregation and attachment to vascular endothelium (Lehr et al., 1994; Weber et al., 1996). As shown in Table 2, vitamin C has also been shown to reduce pesticide mediated T-cell hyperactivation. Given that the formulation of the current invention has greater ability to prevent pesticide-induced T-cell aggregation than other vitamin C formulations, suggests that the formulation of the present invention will provide greater protection against other deleterious xenobiotics.
[0000]
TABLE 2
The vitamin C preparation of Example 1 inhibits xenobiotic
induced homotypic aggregation in human T-lymphocytes more
effectively than calcium ascorbate-calcium
threonate-dehydroascorbate Ester-C ®.
Activators of T-cell Aggregation
Vit. C Added
None
PHA
Bifenthrin
None
10 ± 5
170 ± 15
300 ± 13
AA
9 ± 4
75 ± 12
130 ± 5
CaA
12 ± 4
110 ± 10
137 ± 8
EsterC
8 ± 2
120 ± 17
200 ± 8
*PWC
11 ± 6
20 ± 9
50 ± 10
EXAMPLE 4
[0143] The antioxidant and free radical scavenging activity was determined for the vitamin C preparation of Example 1 and known dietary antioxidants.
[0144] Briefly, 200 ml of a 1, 2.5, 5, 10, or 20 μg/ml solution of the vitamin C preparation of Example 1 was mixed with 50 μl of a 659 μM 1,1-diphenyl-2-picryl hydrazyl (DPPH) solution and incubated at 25° C. for 20 minutes. Free radical scavenging activity of the vitamin C preparation of Example 1 was measured by the reduction of 1,1-diphenyl-2-picryl hydrazyl (DPPH) to 1,1-diphenyl-2-picryl hydrazine at an absorbance of 510 nm. The results are shown in FIG. 2 .
[0145] The vitamin C preparation dose dependently scavenged DPPH free radicals. The vitamin C preparation demonstrated excellent scavenging ability by reducing the DPPH-induced free radical concentration by 93% at its maximum concentration.
[0146] The peroxyl radical oxygen reactive species (ORAC) scavenging ability of the vitamin C preparation was also determined. The ORAC assay detects free radical damage to fluorescein induced by 2,2″-Asobix dihydrochloride (AAPH; 153 mM), and the change is measured by fluorescence spectrophotometry. Antioxidants inhibit the free radical range damage to the fluorescent compound and prevent the reduction in fluorescence. The results are shown in Table 3. The results from different concentrations of the vitamin C preparation of Example 1 were compared to the known antioxidant Trolox®. The ORAC results are expressed as Trolox® equivalents (6-Hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic Acid; TE) per gram of sample.
[0147] Vitamin C is a chemical reducing agent for many intracellular and extracellular reactions such as oxidative DNA or protein damage, low-density lipoprotein oxidation, lipid peroxidation, oxidants, the formation of nitrosamines in gastric juice, extracellular oxidants from neutophils, and endothelium dependent vasodilation. The vitamin C preparation of the present invention, which exhibits potent antioxidant and free radical scavenging effects in vitro, can serve as a good vitamin C preparation to prevent such damage thus contributing to the protection against cancer, cardiovascular diseases, atherosclerosis, and other age-related diseases caused by cytotoxic, genotoxic, and proinflammatory mechanisms.
[0000]
TABLE 3
ORAC values comparing the antioxidant activity of the vitamin C
preparation of Example 1 with known dietary antioxidants.
Nutrient
ORAC
source
(μM TE/g)
Reference
The vitamin C preparation
1343
Example 4
of Example 1
trial #1 1062
trial #2 1394
trial #3 1402
trial #4 1440
Cinnamon
1243
Sua et al., 2007
Freeze-Dried
1027
Schauss et al., 2006
Acai
Green and
761.1
Prior and Cao, 1999
black teas
(235-1526)
Chokeberry
161
Wu et al., 2004
Broccoli
65.8 to 121.6
Kurilich et al., 2002
Soft wheat
32-48
Moore et al., 2005
Careless
21
Wu et al., 2004
gooseberry
EXAMPLE 5
[0148] The ability to promote neurite outgrowth was determined for the formulation of Example 1 and other vitamin C formulations.
[0149] PC12 cells were treated with 100 ng/ml of Nerve Growth Factor (NGF) and incubated for a 24 hour period followed by treatment with either vehicle (-) or various 50 μM of (1) ascorbic acid (AA), (2) calcium ascorbate (CaA), (3) calcium ascorbate-calcium threonate-dehydroascorbate (Ester-C®), or (4) the vitamin C preparation of Example 1 (PWC). The formation of neurites were measured at hours 1, 3, 6, 9, 12, and 24. The results are shown in FIG. 3 .
[0150] PC12 cells responded to NGF treatment by extending neurites. The vitamin C preparation of Example 1 significantly enhanced the NGF-induced neurite outgrowth in 12% of the cells by the first hour. In fact, the vitamin C preparation was the only formulation that resulted in a significant augmentation of NGF-induced neurite outgrowth, suggesting that this is the only formulation that would aid in protection against neurodegenerative diseases.
EXAMPLE 6
[0151] The ability to promote fibroblast adhesion to fibronectin was determined for the formulation of Example 1 and other vitamin C formulations.
[0152] NIH3T3 fibroblastoma cells were seeded onto fibronectin coated plates pretreated with either vehicle (-) or various 50 mM of (1) ascorbic acid (AA), (2) calcium ascorbate (CaA), (3) calcium ascorbate-calcium threonate-dehydroascorbate (Ester-C®), or (4) the vitamin C preparation of Example 1 (PWC). The plates were incubated for 15 minutes at 37° C. The unattached cells were removed by aspiration and the attached cells were fixed, stained, and counted in triplicate. Results are shown in FIG. 4 .
[0153] The vitamin C preparation of Example 1 enhanced fibroblast adhesion to fibronectin by over three-fold. In addition to adhesion, fibroblast spreading on fibronectin is an important next step to migration and wound healing performance.
EXAMPLE 7
[0154] The human serum vitamin C, plasma C-reactive protein, oxidized LDL, and urine uric and oxalate levels were determined for the formulation of Example 1 and other vitamin C formulations.
[0155] Healthy volunteers maintained a low vitamin C diet for 14 days. Following an overnight fast, volunteers received a single oral dose of 1000 mg or either (1) ascorbic acid (AA), (2) calcium ascorbate (CaA), (3) calcium ascorbate-calcium threonate-dehydroascorbate (commercially available as Ester-C® from Nature's Value of Coram, N.Y.) (Ester-C®), or (4) the vitamin C preparation of Example 1 (PWC). Blood samples were collected immediately prior to the oral dose administration and at various time points post ingestion. Urine was collected over a 24-hour time period and saved for oxalate and uric acid assays. Serum vitamin C levels were measured by HPLC with coulometric electrochemical detection. Plasma C-reactive protein and oxidized LDL were measured by enzyme linked immunosorbent assay (ELISA) and urine uric acid and oxalate levels were measured by enzymatic methods.
[0156] The vitamin C preparation of Example 1 is more rapidly absorbed and leads to higher serum vitamin C levels and greater reduction of plasma levels of inflammatory and oxidative stress markers than other forms of vitamin C.
[0000]
TABLE 4
Clinical data comparing the serum vitamin C levels, plasma C-reactive protein,
oxidized LDL levels, and urine uric acid and oxalate levels of the vitamin C preparation
of Example 1 with other vitamin C formulations.
Serum Vitamin C Levels
(mg/dl)
Hrs Post-Admin:
Vitamin C
0
1
2
4
6
24
AA
0.56 ± 0.06
1.2 ± 0.10
1.64 ± 0.18
1.51 ± 0.22
1.46 ± 0.13
0.80 ± 0.09
CaA
0.50 ± 0.05
0.88 ± 0.10
1.12 ± 0.17
1.03 ± 0.13
1.0 ± 0.13
0.59 ± 0.09
EsterC
0.56 ± 0.09
1.3 ± 0.08*
2.17 ± 0.19*
1.54 ± 0.14*
1.51 ± 0.19*
0.85 ± 0.08
*PWC
0.60 ± 0.08
1.22 ± 0.11*
1.69 ± 0.27
1.52 ± 0.16*
1.17 ± 0.12
0.73 ± 0.07
Plasma C-Reactive Protein
Plasma OxLDL
Urine Markers
(ng/ml)
(U/ml)
(mg/dl)
0
24
Change
0
24
Change
Uric Acid
Oxalate
AA
129.75 ± 26
117.00 ± 33
12.75
68.78 ± 6
67.89 ± 5
0.89
50.85 ± 8.8
18.8 ± 2.7
CaA
189.17 ± 41
180.83 ± 43
8.34
60.56 ± 5
57.67 ± 6
3.78
39.75 ± 10.5
17.8 ± 2.6
EsterC
152.30 ± 19
128.60 ± 19
23.7
62.56 ± 5
57.30 ± 4
5.26**
48.73 ± 7.1
13.7 ± 1.5
*PWC
200.63 ± 38
180.00 ± 52
20.63
50.51 ± 4
48.20 ± 4
2.31
40.96 ± 7.0
17.9 ± 1.9
*Statistically significant deference compared to Calcium Ascorbate. At one hour p = 0.0026 for PWC and p = 0.049 for Ester-C. At two hours, p = 0.0009. At four hours p = 0.0278 for PWC and 0.0477 for Ester C. At six hours, p = 0.0470
**Statistically significant difference from Ascorbic Acid (p = 0.045). Note that the reductions in oxLDL were not significantly different for any vitamin C supplementation with a before-and-after comparison; however, the drop observed with PWC was significantly greater than the drop observed with Ascorbic Acid.
Note:
All statistically significant differences are noted. Data are presented as the mean + S.E.M. All 0 time points were immediately prior to oral administration of the vitamin C formulation
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Marionnet C, Vioux-Chagnoleau C, Pierrard C, Sok J, Asselineau D, Bernerd F: Morphogenesis of dermal-epidermal junction in a model of reconstructed skin: beneficial effects of vitamin C. Exp. Dermatol. 2006, 15(8):625-33
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Prior R L, Cao G: Antioxidant capacity and polyphenolic components of teas: implications for altering in vivo antioxidant status. Proc. Soc. Exp. Biol. Med. 1999, 220(4):255-61
Schauss A G, Xianli W., Prior R L, Ou B, Huang D, Owens J, Agarwal A, Jensen G S, Hart A N, Shanbrom E: Antioxidant capacity and other bioactivities of the freeze-dried Amazonian palm berry, Euterpe oleraceae Mart. (Acai). J. Agric Food Chem. 2006, 54(22):8604-10
Su L, Yin J-J, Charles D, Zhou K, Moore J, and Yu L: Total phenolic contents, chelating capacities and radical-scavenging properties of black peppercorn, nutmeg, rosehip, cinnamon and oregano leaf. Food Chem. 2007, 100(3):990-97
Weber C, Erl W, Weber K, Weber P C: Increased adhesiveness of isolcated monocytes to endothelium is prevented by vitamin C intake in smokers. Circulation 1996, 93(8):1488-92
Weeks B S and Perez P P: A novel vitamin C preparation enhances neurite formation and fibroblast adhesion and reduces xenotiotic-induced T-cell hyperactivation. Med. Sci. Monit. 2007, 13(3):BR51-58
Wu X, Gu L, Prior R L, McKay S: Characterization of anthocyanins and proanthocynaidins in some cultivars of Ribes, Aronia, and Sambucus and their antioxidant capacity. J. Agric. Food Chem. 2002, 52(26):7846-56
Zhou X, Tai A, Yamamotol: Enhancement of neurite outgrowth in PC12 cell stimulated with cyclic AMP and NGF by 6-acylated ascorbic acid 2-O-alpha-glucosides (6-Acyl-AA-2G), novel lipophilic ascorbate derivatives. Biol. Pharm. Bull. 2003, 26(3):341-46. | The present invention relates to vitamin C preparations which enhance absorption of vitamin C into cells, and prolong the retention of vitamin C within the blood plasma and tissue of mammals, such as humans. The vitamin C preparations of the present invention include lipophilic molecules which improve the absorption of vitamin C resulting in higher plasma and cellular levels. | 0 |
This application is a division of application Ser. No. 779,287, filed Sept. 23, 1985 now U.S. Pat. No. 4,736,018.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to proteins which inhibit the coagulation of the blood, processes for preparing these proteins, and their use.
2. Description of the Background Art
Anti-coagulant proteins, which are present in most mammals, can be divided into three groups based on their different mechanisms of activity.
One group of proteins form a complex with a coagulation factor and thereby render the coagulation factor inactive. Proteins in this category include antithrombin III (Thromb. Res., 5: 439-452 (1974)), alpha 1 -protease inhibitor (Ann. Rev. Biochem., 52: 655-709 (1983)), alpha 2 -macroglobulin (Ann. Rev. Biochem., 52: 655-709 (1983)), C 1 -inhibitor (Biochemistry, 20: 2738-2743 (1981)), and protease nexin (J. Biol. Chem., 258: 10439-10444 (1983)).
A second group of proteins act proteolytically on a coagulating factor and thereby inactivate it. The only protein of this kind that has been described is protein C (J. Biol. Chem., 251: 355-363 (1976)).
The third category to which anti-coagulant proteins can be grouped are those which screen and/or hydrolyze the negatively charged phospholipids so that the phospholipid-dependent reactions of the blood coagulation mechanism are inhibited. Thus far, only phospholipases isolated from various types of snake venom have been described as having this mode of action (Eur. J. Biochem., 112: 25-32 (1980)).
In recent years, the step-wise coagulation system has been investigated thoroughly. It is understood to be an intensifying multi-stage system of different interconnected proteolytic reactions in which an enzyme converts a zymogen into the active form (cf. Jackson, C. M. and Nemerson, Y., Ann. Rev. Biochem., 49: 765-811 (1980)). The speed of this reaction is decisively increased by the presence of phospholipids and other cofactors such as factor V a and factor VIII a . In vivo, the procoagulation reactions are regulated by a variety of inhibitory mechanisms which prevent an explosively thrombotic trauma after slight activation of the coagulation cascade.
The mechanisms by which the anti-coagulation proteins of these three groups act have been described (Rosenberg, R. D. and Rosenberg, J. S., J. Clin. Invest., 74: 1-6 (1984)).
In Group 1, serine-protease factor X a and thrombin are inactivated as a result of their binding to antithrombin III or to the antithrombin/heparin complex. Both the prothrombin activation and also the formation of fibrin can be inhibited in this way. In addition to antithrombin III, there are also various other plasmaprotease inhibitors such as alpha 2 -macroglobulin and antitrypsin, the activity of which is dependent on time.
In Group 2, the discovery of protein C led to another anti-coagulation mechanism. Once protein C is activated, it acts as an anti-coagulant by selective proteolysis of the protein cofactors V a and VIII a , by which prothrombinase and the enzyme which converts factor X are deactivated.
In Group 3, plasmin cleaves monomeric fibrin 1, a product of the effect of thrombin on fibrinogen, thereby preventing the formation of an insoluble fibrin (Nossel, H. L., Nature, 291: 165-167 (1981)).
Of the above-mentioned native proteins involved in the coagulation process, at present only antithrombin III is clinically used. However, the increase in the tendency to bleed when this protein is administered has proven to be a serious disadvantage.
All the agents previously used as anticoagulants, whether native to the body or synthetic, in some way render the coagulation factors ineffective and thereby lead to side effects which have a disadvantageous effect on the coagulation process.
SUMMARY OF THE INVENTION
It has been found possible to isolate native proteins which have blood coagulation-inhibiting properties, but do not increase the risk of bleeding. These proteins lose their inhibiting properties in the event of major bleeding, so that the normal coagulation processes can proceed without disruption and there is no danger of bleeding to death.
The present invention thus relates to anti-coagulant proteins, hereinafter referred to as VAC (Vascular Anti-Coagulant), which do not inactivate the coagulation factors. These proteins are capable of inhibiting the coagulation induced by a vascular procoagulant or by the factor X a , but do not inhibit the coagulation induced by thrombin. In addition, they do not inhibit the biological and amidolytic activity of factors X a and II a .
DESCRIPTION OF THE FIGURES
FIG. 1: Gel Filtration of VAC on Sephadex G-100
The column (3×80 cm) was prepared at 60 cm pressure and equilibrated with 500 mM NaCl and 20 mM Tris/HCl, pH 7.5. The VAC-containing fraction obtained after DEAE chromatography was concentrated (2 ml) and then passed over the Sephadex G-100. The pressure was maintained at 60 cm. and the void volume was 245 ml (fraction 70). The fractions (2 ml) were dialyzed against Tris-buffered saline (TBS) containing 10% glycerol, and tested for VAC activity by the one-stage coagulation test as described in Example 1. The coagulation times were determined using 1:10 dilutions of the G-100 fractions in TBS. The coagulation time in the absence of VAC was 65 seconds.
FIG. 2: Analytical SDS-PAGE of VAC
SDS-PAGE gels contained by weight 10% acrylamide, 0.27% of N,N 3 -methylene-bisacrylamide, and 0.1% SDS (Laemli, U.K., Nature, 227: 680-685 (1970)):
Lane 1: reduced reference proteins;
Lane 2: 25 ug reduced VAC;
Lane 3: 25 ug non-reduced VAC.
The gel was stained with Coomassie Blue and decolorized in the manner described in Example 1.
FIG. 3: Isoelectric pH of VAC
Electrofocusing was carried out with PAG plates in a pH range of from 3.5-9.5 (see Example 1). 200 ug of human H b 1 and 20 ug of VAC were applied to the gel after the pH gradient had formed in the gel. Human H b was used as a reference (isoelectric point: pH 6.8). The gel was fixed for 30 minutes with 0.7M trichloroacetic acid and stained with Coomassie Blue.
FIG. 4: Analysis of the Binding of VAC to Negatively Charged Phospholipid Liposomes with SDS-PAGE
SDS-PAGE was carried out according to Laemli (Laemli, U. K., Nature, 227: 680-685 (1970)) on the same plates as described in Example 1. The samples analyzed were obtained from the binding experiments as mentioned in the explanation to Table B.
Lane 1: reduced reference proteins; Lane 2: supernatant of VAC preparation centrifuged in the absence of liposomes; Lane 3: supernatant of VAC preparation centrifuged in the presence of liposomes; Lane 4: supernatant of VAC preparation centrifuged in the presence of liposomes and Ca ++ ; Lane 5: supernatant from liposome precipitate of Lane 4 resuspended in TBS (10 mM EDTA) and centrifuged.
FIG. 5: Effect of VAC Concentration on Inhibition (%) of Thrombin Formation
The concentrations of VAC mentioned are the final concentrations present in the test systems. The thrombin formation was measured in 1 uM prothrombin, 10 nM factor X a and 0.5M ( ) or 5.0M ( ) phospholipid membrane (PC/PS; 4:1, mol/mol) in 10 mM TBSA with CaCl 2 . The reaction mixture was stirred with the specified quantities of VAC (Specific activity: 1300 units/mg) for 3 minutes at 37° C. without prothrombin. By adding prothrombin to the mixture, as in Example 1, the thrombin formation was initiated and the speed measured. The speed of thrombin formation in the absence of VAC was 3.3 nM II a /min. ( ) or 10.9 nM II a /min. ( ).
FIG. 6: Effect of Phospholipid Concentration on Inhibition (%) of Thrombin Formation by VAC
Thrombin formation was measured at 1 um prothrombin, 10 nM factor X a , 10.7 ug/ml VAC (Specific activity: 1300 units/mg) and at various concentrations of phospholipid membrane (PC/PS; 4:1, mol/mol) in TBSA. Factor X a , VAC and phospholipid were stirred in TBSA for 3 minutes at 37° C. The thrombin formation was initiated by adding prothrombin to the reaction mixture. The rate of thrombin formation was measured as described in Example 1. The percent inhibition of thrombin formation ( ) was measured for each phospholipid concentration with the corresponding rate of thrombin formation in the absence of VAC ( ).
FIG. 7: Gel Filtration of the 10,000 x g Supernatant of an Umbilical Cord Artery Homogenate on Sephadex G-100
2 ml of the 10,000 x g supernatant of a homogenized umbilical cord was loaded on a Sephadex G-100 column (1.5×80 cm), which was pre-equilibrated with TBS. The column was eluted with TBS. Aliquots of the resulting fractions were tested in the MPTT. Certain fractions ( ) express a procoagulant activity and initiated coagulation in the MPTT without the addition of HTP, factor X a , or thrombin. Other distinct fractions ( ) prolong clotting time in the MPTT, using HTP to initiate coagulation. These fractions were pooled and further fractionated.
FIG. 8: Chromtography of the Anti-Coagulant on DEAE-Sephacel (A) and Sephadex G-75 (B)
The pool, containing the anti-coagulant, from the Sephadex G-100 column was applied to DEAE-Sephacel. Elution was performed with a 200 ml linear gradient of 50-300 mM NaCl (------). Fractions (4 ml) were collected. A 280 was measured for each fraction (--) and anti-coagulant activity assayed in the MPTT using HTP (final concentration: 95 ug protein/ml) as initiator of coagulation ( ). The fractions with anti-coagulant activity were pooled, concentrated, and subsequently applied to Sephadex G-75 (B). Fractions (2 ml) were collected. Each fraction was measured for A 280 (--) and anti-coagulant activity ( ). V o represents the void volume of the column.
FIG. 9: Dose Response of the Anti-Coagulant in the MPTT
Varying amounts of the anti-coagulant were added to the MPTT. Coagulation was initiated with HTP (final concentration: 95 ug protein/ml). Control clotting time was 65 s.
FIG. 10: Gel Electrophoresis of Several Fractions of the G-75 Eluant
Several fractions of the G-75 eluant were analyzed by SDS-PAGE. The gels were silver-stained according to Merril et al., Electrophoresis J., 3: 17-23 (1982)). Lane 1: reduced low molecular weight standards; Lanes 2-6: unreduced aliquots of the G-75 fractions numbers 35, 39, 41, 43 and 50, respectively.
FIG. 11: The Effect of Proteolytic Enzymes on the Activity of the Anti-Coagulant
The anti-coagulant was incubated at 37° C. with protease type I ( , final concentration: 0.11 units/ml), trypsin ( , final concentration: 88 BAEE units/ml) and without proteolytic enzymes ( ). At the times indicated, 5 ul containing 6 ug protein of the anti-coagulant was removed from the reaction mixture and added to the MPTT. Clotting was initiated with HTP (final concentration: 18 ug protein/ml). Control clotting time was 110 s. The units given in this legend for the proteolytic enzymes are calculated from the values supplied by the manufacturer.
FIG. 12: Effect of Vascular Anti-Coagulant on the Clotting Times, Induced in the MPTT by Either HTP, Factor X a , or thrombin
The concentrations of the coagulation initiators (HTP: 18 ug protein/ml, 1.5 nM factor X a , or 0.4 nM thrombin) were chosen to give control clotting times of about 110 seconds (open bars). When factor X a was used, phospholipid vesicles (final concentration 10 uM), composed of Ole 2 Gro-P-Ser/Ole 2 Gro-P-Cho (molar ratio, 20:80) were added to the reaction mixture. Clotting times induced by the indicated agents in the presence of 3.5 ug anti-coagulant protein are shown by the shaded bars.
FIG. 13: Effect of the Anti-Coagulant on Prothrombin Activation by (X a , V a , phospholipid, Ca 2+ ), (X a , phospholipid, Ca 2+ ), (X a , Ca 2+ )
The reaction mixtures contained: (A) 1 uM prothrombin, 0.3 nM X a , 0.6 nM V a , 0.5 uM phospholipid and 10 mM CaCl 2 with 12.0 ug/ml anti-coagulant ( ), 4.8 ug/ml anticoagulant ( ), and 0.0 anticoagulant ( ); (B) 1 uM prothrombin, 10 nM X a , 0.5 uM phospholipid, and 10 mM CaCl 2 with 2.4 ug/ml anti-coagulant ( ), 0.48 ug/ml anti-coagulant ( ), and 0.0 anti-coagulant ( ); (C) 1 uM prothrombin, 75 nM X a , and 10 mM CaCl 2 with 120 ug/ml anti-coagulant ( ), and 0.0 anti-coagulant ( ). At times indicated, samples were removed and thrombin was determined.
FIG. 14: Immunoblots
Immunoblots were obtained by the procedure described in Example 5. Lane 1: bovine aorta protein fraction with VAC-activity; Lane 2: bovine aorta protein fraction with VAC-activity; Lane 3: bovine lung protein fraction with VAC-activity; Lane 4: human umbilical cord artery protein fraction with VAC-activity; Lane 5: rat aorta protein fraction with VAC-activity; and Lane 6: horse aorta protein fraction with VAC-activity.
FIG. 15: Gel Electrophoresis (A) and Anti-Coagulant Activity (B) of the Various Fractions of the G-75 Eluate
Various fractions of the G-75 eluate were subjected to gel electrophoresis as described. The bands were stained with silver by the method of Merril et al., Electrophoresis J., 3: 17-23 (1982). Electrophoresis lane 1: low molecular weight standards; electrophoresis lanes 2-6: equal volumes of non-reduced G-75 fractions with increasing elution volume. Specific quantities of the G-75 fractions, which had been analyzed by gel electrophoresis, were tested in the MPTT using HTP to initiate coagulation. The control coagulation time is represented by the open bar. The figures under the shaded bars correspond to the numbers of the electrophoresis lanes in FIG. 15A.
FIG. 16: Heat Inactivation of the Vascular Anti-Coagulation Agent (VAC)
The anti-coagulation agent was incubated at 56° C. and, after the various incubation periods, 5 ul samples containing 3.6 ug protein were taken, immediately cooled with ice, and tested in the MPTT using HPT as coagulation initiator. The coagulation time of the control sample was 110 seconds.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention relates to an agent which has blood coagulation-inhibiting properties but not the disadvantageous side effects on the coagulation process which accompany the anti-coagulants currently known.
The anti-coagulant proteins of the invention do not deactivate the coagulation factors, but inhibit:
the modified prothrombin-time experiment and/or
the modified activated partial thromoplastin-time experiment and/or
the non-modified prothrombin-time experiment and/or
the prothrombin activation by the coagulation factor X a in the presence of negatively charged phospholipids and Ca 2+ and/or
the intrinsic X-activation by factor IX a in the presence of negatively charged phospholipids and Ca 2+ and/or
the prothrombin activation of isolated stimulated blood platelets and/or
the coagulation induced by the walls of the blood vessels and/or
the coagulation-dependent platelet aggregation.
The invention also relates to anti-coagulant proteins that do not inactivate the coagulation factors and whose inhibitory activity depends on the concentration of phospholipids. The proteins of the invention induce inhibition of prothrombin activation by factor X a . This inhibition depends on the phospholipid concentration and is less at high phospholipid concentrations. Phospholipids are not hydrolyzed by the proteins of the invention.
The invention further relates to anti-coagulant proteins which do not inactivate the coagulation factors and which bind, via the divalent cations Ca 2+ and/or Mn 2+ , to negatively charged phospholipids, which can be found, for example, in vesicles, liposomes or etherosomes and/or, via the divalent cations Ca 2+ and/or Mn 2+ , to negatively charged phospholipids which are coupled with Spherocil. The binding of the anticoagulant proteins of the invention to negatively charged phospholipids is reversible and can be reversed by ethylenediamine tetraacetic acid (EDTA). The proteins according to the invention are capable of displacing factor X a and prothrombin from a negatively charged phospholipid surface.
The invention relates particularly to anti-coagulant proteins which do not inactivate the coagulation factors and have molecular weights of approximately 70×10 3 , 60×10 3 , 34×10 3 , or 32×10 3 , of which the proteins with a molecular weight of 34×10 3 or 32×10 3 have a single polypeptide chain.
The invention preferably relates to a family of anti-coagulant proteins which do not inactivate the coagulation factors and are characterized in that:
they are isolated from the walls of blood vessels in mammals and are then substantially purified,
they are not glycoproteins,
they are not phospholipases,
they have an isoelectric point of pH 4.4-4.6,
the activity of the anti-coagulant proteins at 56° C. is thermally unstable,
the activity of the anti-coagulating proteins in citrated plasma remains stable for some hours at 37° C.,
the activity of the anti-coagulant proteins is not completely destroyed by trypsin and/or chymotrypsin,
the activity of the anti-coagulant proteins is not affected by collagenase and/or elastase,
they bind, via the divalent cations Ca 2+ and Mn 2+ , to negatively charged phospholipids which can be found in vesicles, liposomes or etherosomes,
they bind via the divalent cations Ca 2+ and Mn 2+ to negatively charged phospholipids which are coupled to Spherocil,
the binding of the proteins to the negatively charged phospholipids is reversible and can be removed by ethylenediamine tetracetic acid (EDTA),
they displace factor X a and prothrombin from a negatively charged phospholipid surface,
they inhibit the modified prothrombin-time experiment,
they inhibit the modified, activated, partial thromboplastin-time experiment,
they inhibit the non-modified prothrombin-time experiment,
they inhibit prothrombin activation by the coagulation factor X a in the presence of negatively charged phospholipids and Ca 2+ in vitro,
they do not inhibit the biological and amidolytic activity of factors X a and II a ,
they inhibit the intrinsic X-activation by the factor IX a in the presence of negatively charged phospholipids and Ca 2+ in vitro,
they inhibit the prothrombin activation of isolated, stimulated blood platelets in vitro,
they inhibit the coagulation induced by the walls of the blood vessels in vitro, and
the inhibition of prothrombin activation by factor X a induced by the proteins is dependent on the concentration of phospholipids and is reduced at high phospholipid concentrations.
In particular, the invention relates to VAC proteins substantially free of any animal tissue, especially in substantially pure form.
Suitable starting materials for the isolation of the VAC proteins are the blood vessel walls and highly vascularized tissue of various mammals, for example, cattle, rats, horses, and humans, as well as endothelial cell cultures of these mammals. The arterial walls of cattle, rats, horses, and humans and human umbilical veins and arteries are particularly suitable.
The invention also relates to a process for preparing the proteins of the invention using isolation and purification techniques. In a procedure which is particularly suitable, the starting material is homogenized and subjected to differential centrifugation. The supernatant liquid obtained can then be further treated as follows in any desired sequence. Undesirable contaminants can be precipitated with ammonium sulfate. The supernatant is then further purified by affinity chromatography, for example, using hydroxyapatite; ion exchange chromatography, for example, using DEAE-Sephacel; chromatography over a molecular sieve, such as Sephadex G-100, and immunoabsorption chromatography, for example, with polyclonal or monoclonal antibodies. Depending on the quality of the starting material the purification process can be modified or other purification procedures can be used such as, for example, phospholipid vesicles.
In addition to the classic anti-thrombosis treatment, namely, coagulants taken orally, more recently biosynthetic tissue-plasminogen activator has been administered by the intrasvascular route for cases of manifest thrombosis (N. Engl. J. Med., 310: 609-513 (1984)).
The proteins according to the present invention are especially suitable for preventing thrombosis, for example, during operations, because of their blood coagulation-inhibiting properties while at the same time inhibiting the coagulation-dependent aggregation of platelets.
The present invention therefore also relates to the use of the proteins according to the invention as antithrombotic agents.
The invention further relates to pharmaceutical compositions which comprise at least one protein according to the invention in association with a pharmaceutically acceptable carrier and/or excipient.
The anti-coagulant proteins of the invention can be administered parenterally by injection or by gradual perfusion over time. They can be administered intravenously, intraperitoneally, intrasmuscularly, or subcutaneously.
Preparations for parenteral administration include sterile or aqueous or non-aqueous solutions, suspensions, and emulsions. Examples of non-aqueous solvents are propylene glycol, polyethylene glycol, vegetable oils such as olive oil, and injectable organic esters such as ethyl oleate.
Aqueous carriers include water, alcoholic/aqueous solutions, emulsions or suspensions, including saline and buffered media. Parenteral vehicles include sodium chloride solution, Ringer's dextrose, dextrose and sodium chloride, lactated Ringer's or fixed oils. Intravenous vehicles include fluid and nutrient replenishers, electrolyte replenishers, such as those based on Ringer's dextrose, and the like. Preservatives and other additives can also be present, such as, for example, antimicrobials, antioxidants, chelating agents, inert gases, and the like. See, generally, Remington's Pharmaceutical Science, 16th Ed., Mack, eds. 1980.
The invention also relates to a method for preparing a medicament or pharmaceutical composition comprising the components of the invention, the medicament being used for anti-coagulant therapy.
Results from the isolation and purification of VAC from bovine arteries are shown in Table A. Determination of the level of VAC activity in the supernatant of the 100,000 xg centrifugation was erroneous owing to the presence of procoagulant activity. The components responsible for this activity were found to be precipitated with ammonium sulfate at a saturation level of 35%. It was discovered that the supernatant solution obtained after precipitation with 35% ammonium sulfate contained 100% VAC activity. In order to precipitate this activity, the solution was mixed with ammonium sulfate until 90% saturation was achieved. The resulting precipitate containing the VAC proteins was bound to a hydroxyapatite column in the presence of TBS (100 mM NaCl, 50 mM Tris/HCl, pH 7.5). After washing, the VAC proteins were eluted from this column with an increasing phosphate gradient. At low ion concentration, the VAC proteins were bound to the DEAE-Sephacel column. Elution of the VAC proteins from this column was done using an increasing NaCl concentration gradient. In the final purification step, the proteins were separated on the basis of their molecular weight by gel filtration on Sephadex G-100. A high-salt buffer was used as the eluant to minimize the interaction of VAC with the Sephadex material. VAC was eluted from this column in a volume of about 1.6 times the void volume of the column (see FIG. 1). The total yield of VAC after this final purification was 35%. By SDS-PAGE, all G-100 fractions which showed VAC activity were found to contain two polypeptides (molecular weight 34,000 and 32,000, respectively). In some cases, an additional fraction with a molecular weight of 60,000 showed VAC-activity.
Using SDS-PAGE, only peak fractions 138-140 were homogeneous in relation to the two polypeptides. These fractions were used for all other experiments concerning investigation of bovine VAC described in the specification, with the exception of the experiments for characterizing the binding of bovine VAC to phospholipid liposomes.
In G-100 fraction 139, 3.4% of the VAC activity was found to have a specific activity of 1480 units per mg of protein by means of a one-stage coagulation test (see Example 1 and Table A). This fraction contained no detectable quantity of phospholipid. An extinction coefficient of ##EQU1## was calculated for this purified VAC preparation from the absorption at 280 nm and from the protein content.
As shown in FIG. 2, the two polypeptides with molecular weights of 34,000 and 32,000, which are present in the purified protein material from bovine arteries and to which VAC activity has been ascribed, have a single polypeptide chain. Using Schiff's reagent with basic fuchsin, it was established that both proteins contain few carbohydrate groups. Moreover, no gamma-carboxyglutamate (Gla) residues could be found in either protein. Isoelectric focusing (Example 1) showed that both proteins migrate in a single band corresponding to an isoelectric point of 4.4 to 4.6 (FIG. 3).
The VAC activity was obtained from the PAG plate by elution of this band from the gel. Analysis of the eluant with SDS-PAGE again showed the presence of the two proteins. It was thus possible to confirm that both proteins migrate in a single band in the pH gradient of the PAG plate. In order to check the method, human hemoglobin (Hb) was also investigated by isoelectric focusing. The value of 6.8 found for Hb agrees with the value given in the literature (see FIG. 3).
Binding experiments showed that the VAC activity can bind to negatively charged phospholipid membranes. This binding takes place in the presence of Ca 2+ and Mn 2+ , but not in the presence of Mg 2+ or in the absence of divalent metal ions (see Table B). This binding of VAC activity to liposomes is reversible using EDTA.
Using SDS-PAGE, it was possible to show that both proteins can bind to liposomes in the presence of Ca 2+ and that this binding is disrupted when EDTA is added (see FIG. 4). This is yet another indication that VAC activity can be ascribed to these two proteins.
On storage in tris-buffered saline (TBS) containing 10% glycerol, VAC activity is stable at -70° C. for at least three months, at 0° C. for at least 12 hours, and at 37° C. for at least half an hour. At 56° C., the activity disappears within two minutes.
The activity of VAC prolongs the coagulation time in a one-stage coagulation experiment (Example 1) in which coagulation is triggered with thromboplastin from bovine brains (BTP). Replacement of BTP in this experiment with purified bovine thrombin or purified bovine factor X a showed that VAC prolongs the coagulation time only if factor X a is used to initiate coagulation; coagulation induced by thrombin is not affected by VAC. This indicates that VAC directly inhibits the factor X a activity or that there is some interaction with the prothrombinase complex.
In further testing, an amidolytic thrombin formation test using purified bovine factor X a and prothrombin was carried out. FIG. 5 shows that when prothrombin is activated in the presence of Ca 2+ and phospholipid by means of factor X a to form thrombin, VAC inhibits the prothrombin activation and the degree of inhibition is dependent on the concentration of VAC. Moreover, the inhibiting effect of VAC is greater at a lower concentration of phospholipid.
FIG. 6 shows the phospholipid dependency of the VAC-induced inhibition of prothrombin activation. It is significant that at a phospholipid concentration of zero the prothrombin activation by factor X a is not inhibited by VAC. Control tests showed that VAC itself has no affect on the system of measurement.
Incubation of 5 uM phospholipid [1,2-dioleoyl-sn-glycero-3-phosphoserine (PS)/1,2-dioleoyl-sn-glycerol-3-phosphocholine (PC), 1:4 mol/mol] with 107 ug/ml VAC (specific activity: 1,300 units per mg) and 10 mM Ca 2+ reduced the procoagulant activity within 3 minutes at 37° C. This shows that VAC has no phospholipase activity.
In contrast to antithrombin III (AT-III), VAC has no effect on the amidolytic activity of purified thrombin and no lasting effect on factor X a activity, as measured with the chromogenic substrate S 2337 (N-benzoyl-L-isoleucyl-L-glutamyl-L-pipecolyl-glycyl-L-arginine-p--nitroanilide-dihydrochloride) or S 2238 (H-D-phenylalanyl-L-pipecolyl-L-arginine-p-nitroanilide--dihydrochloride) [see Table C]. This table also shows that the inactivation of factor X a and thrombin by AT-III is not intensified by VAC. Heparin, on the other hand, decisively increases inactivation of thrombin and factor X a in the presence of AT-III. This shows that VAC has neither a heparin-like activity nor an AT-III-like activity.
The isolation of the anti-coagulant of the invention from human tissue may be achieved by the same isolation procedure using, for example, a homogenate of human umbilical cord arteries. In such an homogenate, an anti-coagulant according to the present invention has been discovered by its ability to prolong the clotting time in a prothrombin time test. The anti-coagulation activity became measureable after Sephadex G-100 fractionation of the arterial homogenate [See Example 4]. From further isolation procedures, this activity is associated with a water-soluble substance(s), that carries an overall negative charge at pH 7.9.
Analysis of Sephadex G-75 fractions with gel electrophoresis has shown a positive correlation between the intensity of the 32,000 MW band and the prolongation of the clotting time as measured with a modified prothrombin time test (MPTT) [See Example 4]. The connection between the 32K-band and anti-coagulant activity is demonstrated by the fact that only the 32K-band of the polyacrylamide gel has anti-coagulant activity. In combination with the findings that the anti-coagulant rapidly loses its activity when incubated at 56° C., and that proteolytic enzymes can destroy its activity, it is likely that the anti-coagulant activity is expressed by a single protein with a molecular weight of 32,000 daltons.
Trypsin, in contrast to protease type I, is a poor inactivator of the anti-coagulant. This suggests that the anti-coagulant possesses only a small number of lysine- and arginine-residues that are accessible to trypsin. The nature of the anti-coagulant activity has been studied by initiating coagulation in different ways. Clotting, induced by either the vascular procoagulant, HTP (human brain thromboplastin), or factor X a , is inhibited by the anti-coagulant; thrombin-induced clotting, on the other hand, is not. From these findings, one can conclude that the anti-coagulant interferes with thrombin formation, not with thrombin action.
Prothrombinase reconstituted from purified factors and prothrombin were used to further study the anti-coagulant mechanism [See Example 4]. Under these experimental conditions, the anti-coagulant can inhibit the activation of prothrombin by complete prothrombinase (factor X a , factor V a , phospholipid, Ca 2+ ) and by phospholipid-bound factor X a (factor X a , phospholipid, Ca 2+ ) but not by free factor X a (factor X a , Ca 2+ ).
The time course for prothrombin activation in the presence of the anti-coagulant indicate an instantaneous inhibition of prothrombin activation which remains constant in time. This shows that the anti-coagulant acts neither by a phospholipase, nor by a proteolytic activity. The fact that the activation of prothrombin by factor X a and Ca 2+ is not affected by the anti-coagulant at all, strongly indicates that the anti-coagulant mechanism of the vascular compound differs from that of the well known plasma protease inhibitors such as antithrombin III. Since Walker et al., Biochim. Biophys. Acta, 571: 333-342 (1979), have demonstrated that activated protein C does not inhibit prothrombin activation by factor X a , Ca 2+ and phospholipid, it can also be concluded that this compound is not protein C and does not belong in Group 2 described above.
Preliminary binding studies indicate that the vascular anti-coagulant probably interferes with the lipid binding of factor X a and/or prothrombin. Whether the ability of the anti-coagulant to inhibit prothrombin activation completely accounts for its prolongation of the prothrombin time remains to be established.
The fact that this inhibitor can be found in various types of arteries, but not in poorly vascularized tissue indicates that a physiological modulator of hemostasis and thrombosis, active at the vascular level, has been found.
On the absis of the properties and activities of VAC which have been observed, the blood coagulation mechanism under the influence of VAC may be interpreted.
VAC binds via Ca 2+ ions to negatively charged phospholipids which occur as a result of damage to the tissues and/or because of the stimulation of blood platelets, and thereby reduces the binding of specific coagulation factors (vitamin K-dependent coagulation factors) to the negatively charged phospholipid surface which acts as a catalytic surface for these coagulation factors (Biochem. Biophys. Acta, 515: 163-205 (1985)). As a result, the phospholipid-dependent blood coagulation reactions are inhibited by VAC. On the basis of its mechanism of activity, VAC can be categorized in Group 3 described above.
However, a critical difference between VAC and the other known proteins of this group is that VAC does not hydrolyze phospholipids and therefore does not decompose any essential membrane structures.
Among the properties of VAC which have not hitherto been described for any of the known anti-coagulants is the fact that the anti-coagulation effect of VAC is dependent on the concentration of phospholipids in the coagluation process. This dependency means that the coagulation process which has been initiated, for example, by slight damage to the wall of the blood vessel and/or by slight activation of blood platelets, that is, by a thrombotic process, can be inhibited by VAC. On the other hand, the coagulation process which is triggered by severe damage to walls of blood vessels, wherein phospholipids are present in high concentrations, is not inhibitied by VAC, because of high phospholipid concentrations. The danger of severe bleeding when using VAC is therefore extremely small. This property of VAC is in contrast to all the previously known anti-coagulants which render one or more of the coagulating factors ineffective and thereby increase the risk of severe bleeding.
Another surprising property of VAC is that it does not deactivate the coagulating factor themselves. Consequently, the coagulating factors can still perform their other functions. For example, some active coagulating factors also play a non-hemostatic role in the chemotaxis of the inflammatory cells which participate in the repair of damaged blood vessel walls.
This invention further describes a novel class of anti-coagulant proteins which do not inactivate the coagulation factors. The Examples serving to illustrate the invention and the properties listed should not restrict the invention in any way. Anyone skilled in the art will be able, without any inventive effort, to obtain other proteins which have anti-coagulant properties without inactivating the coagulation factors, using the method described. These proteins also fall within the scope of protection of this invention.
The abbreviations used in the invention have the following meanings:
______________________________________VAC: vascular anti-coagulantPFP: platelet free plasmaTBS: 100 mM NaCl, 50 mM Tris/HCl, pH 7.5EDTA: ethylenediamine tetraacetic acidTBSE: TBS with 2 mM of EDTABTP: thromboplastin from bovine brainsHTP: thromboplastin from human brainsTBSA: TBS with 0.5 mg/ml of human serum albumin, pH 7.9S 2337: N-benzoyl-L-isoleucyl-L-glutamyl-L- pipecolyl-glycyl-L-arginine-p-nitro- anilide-dihydrochlorideS 2238: H-D-phenylalanyl-L-pipecolyl-L-argi- nine-p-nitroanilide-dihydrochlorideAT-III: human antithrombin IIIS.A.: specific activityOle.sub.2 Gro- .sub.-- P-Cho: 1,2,-dioleolyl-sn-glycero-3-phos- phocholineOle.sub.2 Gro- .sub.-- P-Ser: 1,2-dioleolyl-sn-glycero-3-phos- phoserine______________________________________
The nomenclature of the blood coagulation factors used was that recommended by the Task Force on Nomenclature of Blood Clotting Zymogens and Zymogen Intermediates.
Having now generally described this invention, the same will be better understood by reference to certain specific examples which are included herein for purposes of illustration only and are not intended to be limiting of the invention unless otherwise specified. Particularly, it is noted that, in principle, the present invention applies to all anti-coagulants from human and other animal sources, provided that they satisfy the purity and reactivity criteria, and also to preparations of the above-described compounds obtained by methods other than those disclosed herein.
EXAMPLE 1
Characterization of VAC
a. Isolation and Purification of VAC
The chemicals for analytical SDS-PAGE and hydroxyapatite (HTP) were obtained from Bio-Rad. Sephadex G-100 and G-75, DEAE-Sephacel and the "Low Molecular Weight Calibration Kit" were obtained from Pharmacia. The chromogenic substrates S 2337 and S 2238 were obtained from Kabi Vitrum and the Diaflo PM-10 ultrafiltration membrane was obtained from Amicon.
Bovine aortas were taken within half an hour after slaughtering the animals. Bovine blood was collected in trisodium citrate (final concentration 0.38% by weight) and centrifuged for 10 minutes at ambient temperature at 2,000 xg. The plasma containing few blood platelets was then centrifuged again (15 minutes at 10,000 xg). In this way, platelet-free plasma was obtained (PFP).
The aortas from the animals were thoroughly rinsed with TBS (100 mM NaCl, 50 mM Tris/HCl, pH 7.5) immediately after being removed. The inner lining of the aortas was removed and homogenized using a high-speed homogenizer, e.g., the Braun MX 32, in TBSE (TBS with 2 mM EDTA) containing soyabean trypsin inhibitor (16 mg/l) and benzamidine (1.57 g/l).
The material homogenized from eight aortas and containing 20% solids (weight/volume) was centrifuged for 60 minutes at 100,000 xg. The supernatant was saturated with solid ammonium sulfate to 30% saturation, stirred from 30 minutes, and then centrifuged for 20 minutes at 12,000 xg. The resulting supernatant was saturated with solid ammonium sulfate to 90% saturation, stirred for 30 minutes, and centrifuged for 20 minutes at 12,000 xg.
The precipitate was suspended in a small volume of TBS and dialyzed with TBS containing benzamidine (1.57 g/l). The dialyzed fraction was applied to a hydroxy-apatite column (1×20 cm) which had been equilibrated with TBS and the VAC proteins eluted with 200 ml of sodium phosphate buffer (pH 7.5) using a linear gradient (0-500 mM). The fractions containing VAC were combined and dialyzed against 50 mM of NaCl with 20 mM of Tris/HCl at pH 7.5.
This same buffer was used to equilibrate a DEAE-Sephacel column (3×5 cm) on which the dialyzed VAC material was chromatographed. The column was washed with four bed volumes of the equilibration buffer and the VAC eluted with 200 ml of NaCl solution in 20 mM of Tris/HCl, pH 7.5, using a linear gradient (50-300 mM). The fractions containing VAC were collected, dialyzed with 500 mM NaCl in 20 mM of Tris/HCl at pH 7.5 and then concentrated in an Amicon concentration cell using a PM-10 ultrafiltration membrane. The concentrate (2 ml) was applied to a Sephadex G-100 column (3×80 cm) equilibrated with 500 mM NaCl in 20 mM Tris/HCl, pH 7.5.
The eluate was collected in 2 ml fractions and the active fractions dialyzed separately against TBS containing 10% by volume glycerol and stored at -70° C. The entire purification was carried out at 0°-4° C.
b. Determining VAC Activity
Two different methods (see, generally, Harrison's Principles of Internal Medicine, 10th Ed., Petersdorf et al., eds., 1983) were used to determine the VAC activity:
(a) the one-stage coagulation test (modified prothrombin time test)
(b) thrombin formation test.
The one-stage coagulation test was carried out as follows:
In a siliconized glass dish, 175 ul of the fraction to be tested, or 175 ul of TBS as control, were stirred with 50 ul of PFP and 25 ul of dilute BTP (900 rpm). After incubation (3 minutes at 37° C.), coagulation was initiated by adding 250 ul of buffer which contained 80 mM NaCl, 20 mM CaCl 2 , and 10 mM Tris/HCl, pH 7.5. Fibrin formation was recorded optically using a "Payton Dual Aggregation Module" (Hornstra, G., Phil. Trans. R. Soc. London B, 294: 355-371 (1981)). The coagulation time of the control sample was 65 seconds. This test was used during purification to examine the various fractions for the presence of VAC activity. In order to determine the VAC yield during purification, one unit of VAC activity was defined as the quantity of VAC which prolongs the coagulation time in the above test to 100 seconds.
In some cases, BTP was replaced by purified bovine thrombin or the purified bovine factor X a . In this semi-purified coagulation system, the quantity of thrombin or factor X a used were such that the coagulation time of the control sample was also 65 seconds.
The thrombin formation test was carried out as follows:
20 ul of purified bovine factor X a (150 nM), 30 ul of CaCl 2 (100 mM), 30 ul of dilute VAC and 30 ul of PS/PC-phospholipid membrane (the final concentrations are given in the legend accompanying FIG. 6) were placed in a plastic dish containing 181 ul TBSA (TBS with 0.5 mg/ml human serum albumin, pH 7.9).
This mixture was stirred for 3 minutes at 37° C. with a Teflon stirrer. Thrombin formation was initiated by adding 9 ul of purified bovine factor II (33.33 uM). At various times, 50 ul samples of the reaction mixture were added to a plastic dish containing 900 ul of TBSE and 50 ul of chromogenic substrate S 2238 (5 mM, 37° C.). The concentration of thrombin in the reaction mixture was calculated from the change in extinction at 405 nm (Kontron Spectrometer Uvikon 810), using a calibration curve plotted from assays with known quantities of purified bovine thrombin. The percent inhibition caused by VAC was defined as follows: ##EQU2## wherein "a" is the rate of thrombin formation in the absence of VAC in nM II a /min, and "b" is the rate of thrombin formation in the absence of VAC in nM II a /min.
The vitamin K-dependent factors prothrombin and factor X a were obtained by purification of citrated bovine plasma (cf. Stenflo, J., J. Biol. Chem., 251: 355-363 (1976)). After barium citrate absorption and elution, fractionation with ammonium sulfate, and chromatography on DEAE-Sephadex, there were two protein fractions which contained a mixture of prothrombin and factor IX or factor X. Factor X was activated using the method of Fujikawa et al., Biochemistry, 11: 4882-4891 (1972) and using RVV-X (Fujikawa et al., Biochemistry, 11: 4892-4899 (1972)). Prothrombin was separated from factor IX by heparinagarose affinity chromatography (Fujikawa et al., Biochemistry, 12: 4938-4945 (1973)). The prothrombin-containing fractions from the heparin-agarose column were combined and further purified using the method of Owens et al., J. Biol. Chem., 249: 594-605 (1974). The concentrations of prothrombin and factor X a were determined using the method of Rosing et al., J. Biol. Chem., 255: 274-283 (1980). BTP was prepared by the method of Van Dam-Mieres et al., Blood Coagulation Enzymes, Methods of Enzymatic Analysis, Verlag Chemie GmbH, Weinheim. The protein concentrations were determined according to Lowry et al., J. Biol. Chem., 193: 265 (1951).
C. Preparation of Phospholipids, Phospholipid Membranes and Phospholipid Liposomes
Phospholipids were prepared using 1,2-dioleoyl-sn-glycero-3-phosphocholine (18:1 cis /18:1 cis -PC) and 1,2-dioleoyl-sn-glycero-3-phosphoserine (18:1 cis /18:1 cis -PS), as described by Rosing et al., J. Biol. Chem., 255: 274-283 (1980). Separate phospholipid membranes of PC and PS consisting of two layers were prepared using ultrasound as described by Rosing et al., J. Biol. Chem., 255: 274-283 (1980). A supply of phospholipid liposomes was prepared by dissolving the appropriate amount of phospholipid in chloroform which was evaporated using nitrogen. The residual phospholipid was suspended in TBS containing 5% glycerol, carefully mixed with a few glass beads for 3 minutes, then centrifuged for 10 minutes at 10,000 xg. The above solution was discarded and the residue carefully resuspended in TBS containing 5% glycerol. In this manner, the phospholipid-liposome supply solution was obtained. These liposomes were stored at ambient temperature. The phospholipid concentration was determined by phosphate analysis according to Bottcher et al., Anal. Chim. Acta., 24: 203-207 (1961).
Gel electrophoresis on plates in the presence of SDS was carried out according to the method described by Laemmli, Nature, 227: 680-685 (1970) using a gel which contained 10% by weight acrylamide, 0.27% by weight N,N 3 -methylene-bisacrylamide and 0.1% by weight SDS. In gel samples with reduced disulfide bridges, 5% by weight beta-mercapto-ethanol was present. The gels were stained as follows:
(1) 0.25% by weight Coomassie Blue R-250 in 50% by weight ethanol and 15% by weight acetic acid, and decolorized with 10% by weight ethanol and 10% by weight acetic acid, or
(2) with Schiff's reagent prepared from basic fuchsin (Merck) by the method of Segrest et al., described in Methods in Enzymology, Vol. 28, 54-63 (1972), or
(3) with silver as described by Merril et al. in Electrophoresis, 3: 17-23 (1982).
The isoelectric pH measurements of proteins were done using thin layer polyacrylamide gels which contain ampholine carrier ampholyte (PAG plates, LKB) at a pH range of 3.5-9.5 in accordance with the manufacturer's instructions. The pH gradient in the gel was determined immediately after electrofocusing by cutting off a strip of the gel along a line between the anode and the cathode. The electrolytes were eluted from each strip using distilled water and the pH measured with a combined glass electrode.
The Gla determination was carried out by HPLC on a "Nucleosil 5SB" column (CHROMPACK) using the method of Kuwada et al., Anal. Biochem., 131: 173-179 (1983).
EXAMPLE 2
Coupling of Phospholipids to Spherocil
The required phospholipids were dissolved in chloroform and added to the column material (Spherocil, Messrs. Rhone-Poulenc) at a ratio of 5 mg of phospholipid per gram of Spherocil. The chloroform was evaporated with N 2 gas and the dry Spherocil phospholipid was then washed with the buffer in which VAC had been suspended. VAC binds to Spherocil-coupled phospholipid in the presence of Ca ++ and/or Mn ++ when some of the phospholipids are negatively charged.
EXAMPLE 3
50 ul of citrated/platelet-free plasma were mixed with 200 ul of buffer (25 mM Tris/HCl, pH 7.5, 100 mM NaCl), containing kaolin (catalyzes coagulation), inositin (phospholipid source) and VAC were present. This mixture was incubated (3 minutes at 37° C.) and 250 ul of Ca ++ buffer (200 mM Tris/HCl, pH 7.5, 80 mM NaCl, 20 mM CaCl 2 ) was added. The coagulation time was measured as described in Example 1.
EXAMPLE 4
Isolation and Characterization of Anti-Coagulant From Human Tissue
Human blood was collected by venipuncture in trisodium citrate (13 mM) and centrifuged at 2,000 xg for 10 minutes at room temperature. The resulting plasma was recentrifuged at 1,000 xg for 15 minutes in order to obtain platelet free plasma (PFP). A standard pool of PFP was prepared by mixing plasma from several healthy donors.
Human umbilical cords were obtained within 15 minutes after delivery. The arteries were immediately perfused with ice-cold TBS-buffer, subsequently prepared free from the Jelly of Warton, and homogenized in TBS using a whirl mixer (Braun MX32). A 10% homogenate (w/v) was then fractionated.
Fractionation of the supernatant from a 10,000 xg centrifugation of the homogenate on Sephadex G-100 results in a reproducible profile (see FIG. 7). The fractions affecting the coagulation system as measured with the MPTT are indicated in FIG. 7. Procoagulant activity eluted with the void volume. This activity can only be detected in the presence of factor VII in the MPTT, as indicated by experiments in which human congenital factor VII-deficient plasma was used. This establishes that this procoagulant is tissue thromboplastin.
Certain fractions showed a distinct anti-coagulant activity. These fractions were pooled and further purified with DEAE-Sephacel chromatography (see FIG. 8A). The anti-coagulant bound to the DEAE-Sephacel with 50 mM NaCl in 50 mM Tris/HCl, pH 7.9. Elution of activity with a linear gradient of NaCl at pH 7.9 was achieved at 150-160 mM NaCl. The DEAE-fractions expressing anti-coagulant activity were pooled and filtered using Sephadex G-75 (FIG. 8B). The column (1.5×50 cm) was equilibrated with TBS and activity was present in those fractions which corresponded to molecular weights of about 30,000-60,000 daltons.
The MPTT was used as a quantitative assay for the determination of the amount of anti-coagulant activity (see FIG. 9). One unit of anti-coagulant activity was defined as that quantity which prolongs the clotting time in the MPTT, with HTP (final concentration 95 ug protein/ml) as initiator of coagulation, from its control value of 65 s to 100 s. With this assay, it was calculated that from 10 g wet arterial tissue 2 mg protein with approximately 1,200 units anti-coagulant activity can be isolated.
The modified prothrombin time test (MPTT) was carried out as follows:
In a siliconized glass cuvette, 50 ul PFP was stirred at 37° C. with 150 ul TBS, 25 ul of a standard HTP-dilution, and 25 ul TBS (control) or 25 ul of a fraction of the arterial homogenate. After incubation for 3 minutes, coagulation was started at time zero with the addition of 250 ul Ca 2+ -buffer (80 mM NaCl, 20 mM CaCl 2 and 10 mM Tris/HCl, pH 7.9). Fibrin formation was monitored optically (Payton Dual Aggregation Module). When factor X a was utilized to initiate coagulation in the MPTT, HTP was omitted and 25 ul purified factor X a was added together with the 250 ul Ca 2+ -buffer to the diluted PFP.
The modified thrombin time test (MTT) was carried out similar to the X a -initiated MPTT described above, with the exception that the X a -preparation was replaced by 25 ul of purified thrombin.
Protease type I and trypsin (EC 3.4.2.1.4) were obtained from Sigma. HTP was prepared from human brain as described by van Dam Mieras et al., Methods of Enzymatic Analysis, 5: 352-365 (1984). Factor X a , prothrombin and thrombin were purified from citrated bovine blood as described by Rosing et al., J. Biol. Chem., 255: 274-283 (1980). Factor V was purified from bovine blood as described by Lindhout et al., Biochemistry, 21: 4594-5502 (1982). Factor V a was obtained by incubating factor V with thrombin. Prothrombin concentrations were calculated from MW=72,000 and A 280 1% =9.6 (Owen et al., J. Biol. Chem. 249: 594-605 (1974), and factor V concentration was calculated from MW=330,000 and A 280 1% =9.6 (Nesheim et al., J. Biol. Chem., 254: 508-517 (1979). Factor X a and thrombin concentrations were determined by active site titration (Rosing et al., J. Biol. Chem., 253: 274-283 (1980). Other protein concentrations were determined as described by Lowry et al., J. Biol. Chem., 193: 265 (1951).
Phospholipid and phospholipid vesicles were prepared using Ole 2 Gro-P-Cho(1,2-dioleoyl-sn-glycero-3-phosphocholine) and Ole 2 Gro-P-Ser(1,2-dioleoyl-sn-glycero-3-phosphoserine) as described in Rosing et al., supra (1980). Single bilayer vesicles composed of Ole 2 Gro-P-Ser/Ole 2 Gro-P-Cho (molar ratio 20:80) were prepared by sonication. Phospholipid concentrations were determined by phosphate analysis according to the method of Bottcher et al., Anal. Chim. Acta, 24: 203-207 (1961).
The time course of prothrombin activation was examined at different concentrations of anti-coagulant. Mixtures of (X a , Ca 2+ ), (X a , phospholipid, Ca 2+ ) or (X a , V a , phospholipid, Ca 2+ ) were stirred with different amounts of the anti-coagulant at 37° C. in 50 mM Tris/HCl, 175 mM NaCl, 0.5 mg/ml human serum albumin at pH 7.9. After 3 minutes, prothrombin activation was started by the addition of prothrombin. At different time intervals, a 25 ul sample was transferred from the reaction mixture into a cuvette (37° C.), containing TBS, 2 mM EDTA and 0.23 mM S 2238 (final volume: 1 ml). From the absorption change at 405 nm (Kontron Spectrophotometer Uvikon 810), and a calibration curve based on purified thrombin, the amount of thrombin formed was calculated at different concentrations of anti-coagulant.
Phospholipid was added in the form of vesicles composed of Ole 2 Gro-P-Ser and Ole 2 Gro-P-Cho with a molar ratio of 20:80.
Several fractions from G-75 chromatography were tested by MPTT and analyzed using SDS-PAGE. The results (FIG. 10) showed that the anti-coagulant has a molecular weight of approximately 32,000 daltons. The anti-coagulant activity of the 32K-band was confirmed by slicing the polyacrylamide gel, eluting the protein and testing the eluant for anti-coagulant activity as described above. Anti-coagulant activity was found only in the eluant in the slice corresponding to the 32K band. This activity was found to be stable at 56° C. and had a dose response relationship in the MPTT similar to the starting material.
The G-75 fractions containing the highest anti-coagulant activity were pooled and used for further characterization of the anti-coagulant. Incubation of the anti-coagulant at 56° C. rapidly decreases its activity until after 2 minutes no activity can be measured. The anti-coagulant loses its activity completely within 2 hours upon incubation at 37° C. with protease type I, whereas trypsin has little effect on the anti-coagulant after an incubation period of 3 hours (FIG. 11). The protease type I and the trypsin concentration used in these experiments, completely inactivate 2.5 nM thrombin in 15 minutes. The amounts of protease type I and trypsin, carried over from the reaction mixtures to the MPTT, have no effect on the control clotting time.
The MPTT is prolonged in the presence of the anti-coagulant (FIG. 12) both when initiated with HTP and when started with factor X a . Thrombin-induced coagulation, however, is not inhibited.
Because of these findings, we investigated the effect of the anti-coagulant on the conversion of prothrombin to thrombin by factor X a , factor V a , phospholipid and Ca 2+ . Under the experimental conditions mentioned, thrombin formation is inhibited by the anti-coagulant in a dose-dependent way (FIG. 13A). The activation of prothrombin by factor X a , phospholipid and Ca 2+ in the absence of factor V a can be inhibited also by the anti-coagulant (FIG. 13B). However, this inhibition is not observed if the activation takes place in the absence of phospholipid (FIG. 13C).
EXAMPLE 5
Polyclonal Antibodies Against VAC
Polyclonal antibodies against bovine VAC were raised in a rabbit. Bovine VAC, purified according to the method as described in Example 1, was mixed with equal amounts of complete Freund's adjuvant. The mixture was injected subcutaneously into a rabbit. After a period of 4 weeks, the rabbit was re-injected subcutaneously with purified bovine VAC. The subcutaneous injections were repeated twice at two-week intervals. Ten days after the last injection, the rabbit was bled and the collected blood was allowed to clot in order to obtain serum.
Immunoglobulins (Ig) were isolated from the serum according to the following method:
(a) The serum was heated for 30 minutes at 56° C.
(b) Subsequently, the serum was applied to DEAE-Sephacel, which was equilibrated with 50 mM Tris, 100 mM NaCl, pH 8.2.
(c) The non-bound protein was precipitated with (NH 4 ) 2 SO 4 at 50% saturation.
(d) The precipitated proteins were pelleted by centrifugation and the pellet resuspended in 50 mM Tris, 100 mM NaCl, pH 7.9 and dialyzed extensively against the same buffer.
(e) The resulting protein mixture contained anti-VAC Ig.
Following the procedure as described, protein fractions which express VAC-activity were isolated from bovine aorta, bovine lung, rat and horse aorta, and human umbilical cord arteries.
The proteins were separated by electrophoresis on a polyacrylamide gel in the presence of dodecyl sulfate and under non-reduced conditions. After completion of the electrophoresis, the proteins were transferred from the gel to nitrocellulose sheets as described by Towbin et al., Proc. Natl. Acad. Sci., USA, 76: 4350-4354 (1979). The sheets were incubated with the anti-VAC Ig and after thorough washing the sheets were incubated with goat anti-rabbit Ig coupled to horseradish peroxidase. The latter was visualized with the peroxidase substrate diamine bezidine tetrahydrochloride.
A brown band on the nitrocellulose sheet, after completion of the described procedure, indicated the presence of goat anti-rabbit Ig. Furthermore, on this spot were present anti-VAC Ig and proteins to which the anti-VAC Ig was bound.
Immunoblots of proteins with VAC activity, isolated from bovine aorta, bovine lung, rat and horse aorta, and human umbilical cord arteries are presented in FIG. 14.
These results show that by essentially using the isolation procedure as described, a protein fraction with VAC activity can be obtained from bovine aorta, bovine lung, rat and horse aorta, and human umbilical cord arteries. Moreover, the isolated protein fractions with VAC activity contain proteins, with MW of approximately 32,000, 34,000, and 70,000, that react with anti-VAC Ig raised against purified bovine VAC in rabbits.
EXAMPLE 6
Purification of VAC, Using Large Volume Phospholipid Vesicles
Large volume phospholipid vesicles (LVV), composed of 1,2-dioleoyl-sn-glycero-3-phosphoserine (PS) and 1,2-dioleoyl-sn-glycero-3-phosphocholine (PC), were prepared by the method of P. van de Waart et al., Biochemistry, 22: 2427-2432 (1983).
For the purification step, LVV containing PS/PC (molar ratio 20:80) was used. Other molar ratios can be used as long as negatively charged phospholipids are present. The chain length of the fatty acids in the phospholipids can also be varied.
LVV, ±1 mM phospholipids in 50 mM Tris/HCl, 100 mM NaCl, pH 7.9, were mixed with an equal volume of a protein fraction containing VAC activity. The proteins were in 50 mM Tris/NaCl, 10 mM CaCl 2 , pH 7.9. The mixture was allowed to stand for 5 minutes at ambient temperature. Subsequently, the mixture was centrifuged for 30 minutes at 20,000 xg. The pellet was resuspended in 50 mM Tris/HCl, 100 mM NaCl, 10 mM CaCl 2 , pH 7.9, and recentrifuged. The resulting pellet was then resuspended in 50 mM Tris/HCl, 10 mM ethylenediamine tetraacetic acid (EDTA), pH 7.9, and recentrifuged. The resulting supernatant contained the VAC activity.
The above described procedure is an efficient purification step in the procedure to obtain purified VAC.
TABLE A______________________________________Summary of the Purificationof VAC from Inner Coat of Bovine Aorta Specific DegreePurification Protein.sup.a VAC.sup.b Activities Yield of Purifi-Step mg Units units/mg % cation______________________________________Supernatant 630 19.000 31.0 100 1.0liquid with35% (NH.sub.4).sub.2 SO.sub.4Precipitate 470 19.000 40.4 97 1.3with 90%(NH.sub.4).sub.2 SO.sub.4Hydroxyapatite 206 17.300 84.0 89 2.7fractionDEAE fraction 35.8 13.900 388 71 12.5Sephadex G-100 0.45 0.666 1480 3.4 47.7fraction 139______________________________________ .sup.a Protein was determined using the method of Lowry et al. (J. Biol. Chem., 193: 265 (1951). .sup.b The VAC units were determined using the onestage coagulation test described in Example 1 by a series of test dilutions. The coagulation tim of the control samples was 65 seconds. One unit of VAC activity was defined as the quantity of VAC which prolongs the coagulation time to 100 seconds.
TABLE B______________________________________Cation-Dependent Binding of VACto Negatively Charged Phospholipid Liposomes t.sub.c, seconds.sup.a SupernatantCation (10 mm) Liquid.sup.b EDTA.sup.c______________________________________Control (no 180 N.D..sup.dliposomes)Control (no 174 64.8cation)CaCl.sub.2 64.2 134MgCl.sub.2 165 N.D.MnCl.sub.2 65.1 N.D.______________________________________ .sup.a The coagulation time (t.sub.c) was determined using the onestage coagulation test described in Example 1. .sup.b 50 ul phospholipid liposomes (PS/PC; 50/50 mol/mp: 1 mm), 50 ul VA (250 ug/ml, specific activity = 700 units per mg), and 100 ul of TBS containing 5% glycerol and cation, pH 7.5, were mixed at ambient temperature and centrifuged for 15 minutes at 15,000 xg. Supernatant liquid (25 ul) was diluted with TBS to a final volume of 175 ul and teste using the onestage coagulation test. The remainder of the supernatant liquid was analyzed with SDSPAGE (FIG. 4). .sup.c The liposome precipitate was suspended in 150 ul of TBS containing 5% glycerol and 10 mm EDTA, pH 7.5. The suspension was centrifuged for 15 minutes at 15,000 xg. The VAC activity of the supernatant was analyzed as described above. .sup.d N.D. = not determined.
TABLE C______________________________________Effect of VAC on theAmidolytic Activity of Factor X.sub.a and Factor II.sub.a VAC (A.sub.405 /min × 10.sup.3).sup.a - +______________________________________X.sub.a 110.5 110.5X.sub.a, AT-III 80.0 81.5X.sub.a, Heparin 110.5 109.0X.sub.a, Heparin, AT-III 47.5 N.D..sup.bII.sub.a 7.5 7.5II.sub.a, AT-III 5.4 5.6II.sub.a, Heparin 7.5 7.1II.sub.a, Heparin, AT-III 0.56 N.D..sup.______________________________________ .sup.a The amidolytic activity was measured as follows: Factor X.sub.a or Factor II.sub.a was diluted with the abovementioned agents in TBSA. The reaction mixture was stirred with a Tefloncoated stirrer in a plastic dis (37° C.). After 10 minutes, a sample of 100 ul (X.sub.a) or 50 ul (II.sub.a) was placed in another plastic dish (37° C.) which contained 800 ul of TBSE, 100 ul of TBSA, and 100 ul of S 2337 (2 mM) or 900 ul S 2238 (5 mM). The change in absorption at 405 nM was measured using a Kontron Spectrophotometer Uvikon 810 (37° C.). The final concentrations of the various agents in the reaction mixtures were as follows: Factor X.sub.a (18.7 nM); Factor II.sub.a (1.5 nM); human ATIII (18.7 nM); heparin (1 unit per ml); and VAC (10.7 ug/ml, specific activity: 1300 units/mg). .sup.b N.D. = not determined | This invention discloses proteins which inhibit the coagulation of the blood, processes for preparing these proteins, and the use thereof. | 8 |
BACKGROUND OF THE INVENTION
The present invention relates to automatic clothes washing machines and more particularly to an improved structure in such machines for effecting the washing of relatively small loads of clothing and especially heavily soiled clothing in a high detergent concentration.
Automatic clothes washing machines customarily provide, in a clothes basket adapted to hold several pounds of clothes, a sequence of operations in order to wash, rinse and extract water from the clothes in the basket. The sequence ordinarily includes a water fill followed by a washing operation which, in a vertical axis type machine, is provided by an agitator movably arranged to oscillate within the basket; a first centrifugal liquid extraction operation in which the wash water is removed from the clothes by spinning the basket; another water fill followed by a rinsing operation in which the clothes are rinsed in clean water while the agitator is oscillated; and a final centrifugal liquid extraction operation in which the basket is spun to remove rinse water from the clothes. Machines having this type of cycle, or a variation thereof, generally produce highly satisfactory results in that the clothes come out properly cleaned and with a substantial part of the liquid removed.
In the case where clothes are extremely dirty or soiled with difficult to remove spots, they will emerge from the cycle of operations with at least some of those spots still visible. Generally, these exceptionally dirty clothes are a minority relative to a full wash. Thus, it would not be economical to add extra detergent to the full load of clothes just for the sake of cleaning an isolated heavily soiled item.
These types of clothes should be washed by themselves so that special treatment may be given to each item. One disadvantage which presents itself when very small loads are washed in the basket of a washing machine is that the amount of water required for washing a few items may be comparable to the amount of water used for washing several pounts of clothing. This, of course, represents an inefficient use of water with a resulting high cost of water and energy in heating the water in consideration of the results being obtained. Also, there is a correlary that the greater the quantity of water used, the greater the quantity of detergent needed in order to effect a proper detergent concentration in the water. This is even more critical in the instance of heavily soiled clothes which would require greater amounts of detergent. Considerations such as these have quite often led the owners of domestic clothes washing machines to do the washing of heavily soiled clothes by hand despite the availability of the machine.
One solution to this problem is the use of a small basket placed on the agitator inside the larger regular wash clothes basket. The motion of the agitator carries with it the small basket and provides a motion of the liquid in the basket which causes a suitable type washing action. This type of washing machine is described in U.S. Pat. No. 3,014,358 and is assigned to the assignee of the present invention. In the use of a small wash basket as described in U.S. Pat. No. 3,014,358 the clothes within the small basket are subjected to the same operational cycles as when the machine is used with a "normal" operation. The disadvantage in such a clothes washing cycle is that the water is continuously recirculated through the small basket. Accordingly, while the smaller basket has a relatively small volume the water level in the smaller basket is maintained by circulating all of the water in the machine machine through the smaller basket during the washing operation. This causes the detergent that is placed in the small basket to be diluted into the recirculating water in the machine.
Provision is made whereby during the washing cycle of operation only a predetermined volume of the fill water is circulated into the smaller basket during a timed recirculation cycle in which the recirculation of water is terminated prior to the wash cycle. While this relatively small volume of water is retained therein during the entire washing cycle of operation. This ability to confine a limited water volume allows for the attainment of a very high detergent concentration with the usage of reasonable and acceptable amount of detergent it also disables the lint removal ability since water is not circulating through the filter.
By the present invention means are provided whereby the washing action of the small basket causes a recirculation of the water therein through of filter.
Following this initial wash in a high detergent concentration the machine reverts to its "normal" cycle of operation; wherein all of the fill water in the machine is once again recirculated through the filter and small basket during the ensuing spin, rinse, and extraction cycles of operation.
SUMMARY OF THE INVENTION
By the present invention there is provided a vertical axis clothes washing machine comprising a liquid and clothes containing means including a relatively large substantially imperforate outer receptacle, and a relatively large perforated clothes receptacle positioned within the receptacle. An agitator extendes upwardly into the clothes receptacle. A drive system is provided for rotating the clothes receptacle and the agitator at a relatively high speed, including means for effecting a washing motion of the agitator. A water inlet means provides fresh water to the liquid and clothes containing means. Positioned on the agitator and movable therewith is a relatively small substantially imperforate basket which has overflow openings adjacent the top thereof. A primary recirculation system including a conduit connected between an inlet in the outer receptacle and an outlet positioned for supplying liquid to the small imperforate basket are arranged to pump liquid from the outer receptacle through the outlet means. A perforated filter pan is mounted on the agitator covering substantially the entire top of the imperforate basket. Further, the control means includes valve means in the conduit for allowing a predetermined amount of liquid to flow through the outlet means whereby clothes contained in the small imperforate basket are washed in the predetermined amount of liquid independently of liquid in the outer receptacle.
A secondary recirculation system for supplying water through the filter pan to the small basket by the washing motion of the agitator independent of the primary recirculation system.
DESCRIPTION OF DRAWINGS
FIG. 1 is a front elevational view of a clothes washing machine incorporating the present invention, the view being partially broken away and partially in section to illustrate details;
FIG. 2 is an enlarged fragmentary view showing certain details of the present invention; and
FIG. 3 is an enlarged fragmentary view showing another embodiment of a portion of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings there is shown an agitator type clothes washing machine 10 having a conventional basket or clothes receiving receptacle 11 perforated over its side and bottom walls with perforations 12 and disposed within an outer imperforated tub 13. Tub 13 is mounted within an appearance cabinet 14 which includes a cover 15 hingedly mounted in the top portion 16 of the cabinet for providing access through an opening 18 to the basket 11. At the center of the basket 11 there is positioned a vertical axis agitator 20 which includes a center post 21 and a plurality of water circulating veins joined at their lower ends by an outwardly flared skirt 22.
Both the clothes basket 11 and the agitator 20 are rotatably mounted. The basket 11 is mounted on a flange of a rotatable hub 24 and the agitator is mounted on a shaft 25 which extends upwardly through the hub and through the center post 21 and is secured to the agitator so as to drive it. During the cycle of operation of the machine the agitator 20 is first oscillated back and forth on its axis, that is, in a horizontal plane within the basket 11 to wash the clothes therein. Then after a predetermined period of this washing action the basket 11 is rotated at a high speed to extract centrifugally the washing liquid from the clothes and discharge it to drain as will be explained. Following this extraction operation a supply of clean water is introduced into the basket for rinsing the clothes and the agitator is again oscillated. Finally, the basket is once more rotated in high speed to extract the rinse water.
The basket 11 and agitator 20 may be driven by any suitable means as the drive means forms no part of the present invention. However, by way of example they are shown driven from a reversible motor 26. The motor 26 drives the basket 11 and the agitator 20 through a drive including a clutch 27 which is mounted on the motor shaft. The clutch 27 allows the motor 26 to start within a load and then to accept the load as it comes up to speed. A suitable belt 28 transmits power to a transmission assembly 30 through a pulley 31. Thus, depending upon on direction of motor rotation the pulley 31 of the transmission is driven in opposite directions. Preferably, as will be more fully explained below, transmission clutch 27 is also a two-speed clutch. Specifically, in the illustrated machine the clutch 27 provides a direct drive between the motor 26 and the pulley 31 and a reduced speed drive to the pulley 31. The transmission 30 is so arranged that it supports and drives both the agitator drive shaft 25 and the basket mounting hub 24. When the motor 26 is rotated in one direction the transmission causes the agitator 20 to oscillate in a substantially horizontal plane within the basket 11. Conversely, when the motor 26 is driven in the opposite direction the transmission 30 rotates the wash basket 11 and agitator 20 together at high speed for centrifugal extraction. In order to introduce fresh water to the machine a suitable conduit 34 is provided having an outlet opening into the tub 13 so that suitable washing and rinsing liquid may be introduced in the desired quantities into the tub 13 and basket 11. It will at this point be noted that in the preferred construction shown the perforations 12 of the basket 11 cause the interior of the basket 11 to be in full communication with part of the tub 13 which is exterior to the basket 11 so that the liquid level in both the basket 11 and the tub 13 is the same. Thus, as the water rises in one it will also rise in the other. With this type of structure suitable means may thus be provided in the tub 13 to determine when the appropriate water level in the basket 11 has been reached. In the present case this structure is provided in a conventional manner by means of a tube 36 which extends from an opening 37 adjacent the bottom of the tub 13 up to a pressure sensitive water level control 38 which may be of the conventional type.
In effect, in this type of water level control an electric switch (not shown) is included in the device 38 and the switch is operated in response to an increase of the air within the conduit 36. The increase in air pressure coming as a result of compression of air by a rise in the level of water in the tub 13. A further conventional embodiment of level control is the provision of means for varying the point at which the switch is closed by the air pressure so that any one of several different air pressures may be selected for the closing of the switch. In this manner different levels within the tub may be selected by movement of dial 39 to different positions. In the present embodiment a 4-position control is employed. One position provides a level which substantially fills the basket 11, a second setting provides about two-thirds of a basket, a third setting shuts off the incoming water when it reaches about half the height of the basket, and the fourth lowest level which will be more fully discussed in connection with the present invention shuts off the incoming water when it reaches a very low level in the tub which may well not even rise to the bottom of the basket 11.
In the direction of rotation which is provided for the washing operations the motor 26 drives a pump 40 through a flexible coupling 41 in the appropriate direction to discharge liquid from the bottom of the tub 13 into a conduit 42 which leads to a nozzle 43. The nozzle 43 is positioned relative to a filtering member 44 secured on the top of the agitator 20 so as to be movable therewith so that liquid is recirculated by pump 40 hooked up through the conduit 42 and out of the nozzle 43 into the oscillating filter pan 44. It will be observed that the filter pan 44 has a substantial number of small openings 45 formed therein so that the water coming from the nozzle 43 passes down through the openings 45. The filter pan 44 with its many small openings and its upstanding side walls causes the lint, which is separated from the clothes during the washing operation, to be filtered out of the water and thus prevents it from being redeposited on the clothes.
Hot and cold water may be supplied to the machine through conduits 46 and 47 which are adapted to be connected respectively to sources of hot and cold water (not shown). Conduits 46 and 47 extend into a valve structure having solenoids 48 and 49 and being connected to a hose 51.
Also secured on the agitator so as to move therewith is a clothes containing basket 50 which is small relative to the basket 11 and the tub 13. The basket 50, except for overflow openings 52 adjacent the top thereof, is imperforate. The lower inner portion of the annular basket 50 may be formed to accommodate the tops of the vanes 19 of the agitator 20, in addition providing small washing vanes within the basket 50 itself. This positions the basket 50 securely on the agitator 20 so that there will not be any relative rotation of the two. The basket 50 is positioned below the filter pan 44 so that water which is poured into the filter pan from the nozzle 43 passes through the openings 45 in the filter pan 44 down into the basket 11. Thus, in effect the filter pan affects a filtering action of the water prior to its entry into the basket 11.
The filter pan 44 and basket 50 are preferably removably positioned on the agitator 20 so that they may be removed when so desired, for instance, for inserting clothes into the basket 11 and readily replaced on the agitator 20 secured thereto as to move therewith.
Completing the description of the structure, when enough washing has been provided and it is intended to remove the washing liquid from the clothes the direction of rotation of the motor is reversed. As described above, this causes the basket 11 and agitator 20 to rotate together at a relatively high speed so as to centrifuge the washing liquid out through the openings 12. The washing liquid thus removed is caused by the pump 40 rotating in the reverse direction to the previous rotation thereof to discharge into a conduit 56. The conduit 56 is adapted for discharge to a drain line 58 so that the pump 40 is effective to drain the tub 13.
As mentioned herein above, the control member 38 may be used to provide four different water levels in the tub 13, three of them being operative to provide water within the basket 11 and one of them being at such a low level within the tub 13 that there is insufficient water in the basket 11 to provide any washing action. This last low water level is provided when generally it is desired to use the small basket 50 to wash a very small load which generally occurs when delicate or heavily soiled garments of the type which constitute a small minority of all clothes worn must be washed and there is insufficient quantity to justify the use of the large basket 11.
In the present machine the small basket 50 is adapted to be used, as will be explained fully hereinafter, to wash a small quantity of clothes in a very high detergent concentration relative to the amount of water in the basket 50. In this instance the use of the small basket and a high concentration of detergent enhances the stain removal capability of the washing machine.
Use of the basket 50 and its cycle of operation in washing a normal small quantity of clothes will now be described. When such a load is to be washed the small basket 50 is placed on the agitator mechanism as shown and the filter pan 44 is then placed over the small basket 50.
When the lowest liquid level selected is reached in the basket and outer tub as described the motor 26 starts operation in the direction suitable for moving the agitator mechanism. As described this also causes the pump 40 to operate in the direction to pump water up through the conduit 42 and out from the nozzle 43 into the filter pan 45. This water then passes through the openings 45 in the filter pan 45 down into the basket 50 containing a small quantity of clothes. Because the basket 50 is substantially imperforate the water quickly rises in the basket regardless of the fact that the basket 11 does not have any water or virtually no water in it. The water continues to rise in the basket 50 until it reaches substantially to the level of the overflow outlets 52.
As mentioned above, provision is made to employ the small basket 50 to wash a small quantity of clothes having a heavy soil concentration in a relatively small volume of water. This enables the user to establish a high concentration of detergent while using a relatively small volume of water and detergent. To this end, circulation of liquid to the basket 50 is terminted once the liquid level reaches the overflow apertures 52. At this point in time, because of the relatively small volume of water in the basket 50 the clothes can readily be washed in a high concentration of detergent during a heavy soil removal cycle of operation while using reasonable amounts of detergent. To this end, a pinch valve 59 is provided which is operated by a solenoid 60 arranged in conduit 42. The solenoid 60 is energized to cut recirculation flow to the basket 50 after a predetermined amount of time. In carrying out the operation of washing clothes in the small volume of water in basket 5, the solenoid is activated to cut of the flow of water to basket 50 after 30 seconds which time was found appropriate to transfer a volume of water from tub 13 sufficient to fill the basket 50.
In the lowest water level selection the water volume in the outer tub and basket is greater than needed to fill the small basket 50. While it might result in using less water by filling the small basket directly, controlling the temperature of the wash water would be difficult if not impossible. This is especially true in selecting a hot water wash since the initial flow would normally be cold until the lines are purged. Because of the relatively small volume of water required to fill the small basket it will, in most instances, fill with cold water before the supply line is purged and the hot water reaches the basket 50.
Accordingly, this problem is eliminated by first filling the outer tub and basket in the normal manner. This volume of water even at the lowest water setting is sufficient to purge the hot water supply line of cold water and still provide adequate hot water for the wash cycle.
In the machine thus far described the small basket 50 provides means for isolating and confining a limited water volume in the range from 1.0 to 2.5 gallons during the activation or wash cycle of operation. This ability to confine a limited water volume in the wash cycle of operation allows for the attainment of very high detergent concentrations in the range from 0.8 to 3.3 weight percent based on the usage of reasonable and acceptable amount of detergent in the range from 75 to 125 grams. The high concentration of detergent achieved together with the agitation provided during the wash cycle of operation have been found to enhance washing performance significally. By way of comparison, these detergent concentrations were 8 to 33 times that commonly achieved in washing clothes in the larger clothes basket.
As thus far described the machine is fully disclosed in co-pending application designated 90-HL-16624-McMillan et al assigned to the General Electric Company the assignee of the present application. It is apparent that the ability to employ a high detergent concentration in the present machine is made possible by allowing the recirculation system to fill the small basket 50 and to then terminate recirculation flow so that the clothes are washed in this limited amount of water. While this provides an effective high detergent concentration wash operation, it nevertheless by disabling the recirculation system stops the filtering function of the filter pan 40 during this initial wash cycle period.
By the present invention means are provided in conjunction with the above described clothes washing machine to insure that a filtering system is operational during the initial washing cycle when the flow through conduit 42 is cut off and the clothes are being washed in the basket 50. The means includes a secondary recirculating system whereby the small volume of water in the basket 50 is recirculated therethrough independent of the primary recirculation system thus far described.
With reference to FIG. 2, the bottom wall 60 of the basket 50 is formed to include a plurality of sump areas 62. The exact number of sump areas provided is not critical in carrying out the present invention, however, it is necessary that they be arranged so as to maintain a proper balance of the basket 50 during the high speed centrifugal extraction cycle. The sump areas 62 as will be described hereinafter are in effect sediment traps. Positioned in the outer radial portion of each sump area 62 is an outlet 64. Recirculating conduits 66 are connected so as to communicate at one end with the outlet 64. The conduits 66 as shown are formed as part of the basket 50 and extend upwardly along the side wall 67 of the basket 50. The conduits 66 terminate at their upper end in an outlet 68 extending above the upper end of the basket side wall 67. Positioned on the outlet 68 of conduit 66 is a deflecting member 70 which is dimensioned to divert water exiting the conduit 66 into the filter pan 44 as shown by directional arrows 72. During the washing cycle the turbulence of the water generated by the oscillation of the basket 50 causes a portion of the water in the lower extremities of the basket 50 to be pumped up through the conduits 66 and into the filter pan 44 where it flows through opening 45 to reenter the basket 50. This pumping action of water through the conduits 66 provides a continuing recirculation of water in the basket 50 during the washing action of the machine. The number and size of the conduits 66 are selected to insure that the amount of water recirculated through the conduits is sufficient to provide an effective filtering of lint and other water-bourne debris from the clothes.
While the recirculation of water through the basket 50 is referred to as a secondary recirculation system, it should be noted that the present system may be employed in a washing machine not having a primary recirculation system. In which instance the system as taught by the present invention would function as a recirculating lint removal system for the small gasket.
During the agitation process of the washing action, heavy dirt particles dislodged from the clothing by the oscillating action of the agitator fall by gravity to the bottom wall 60 of the basket 50. As mentioned above means are also provided by the present invention to insure the removal of sediments from the wash water in basket 50. The movement of the water within the basket 50 directs the sediment into the sump areas 62 as indicated by arrows 72 where the unwanted material remains during the balance of the washing operation. Arranged in the radial end of each sump area 62 is a centrifugal valve shown generally at 74. The exact structure of the valve 74 is not critical in carrying out the present invention other than it opens when the basket 50 is rotated during its high speed extraction cycle. During the following high-speed extraction cycle the centrifugal valve 74 opens as shown in broken lines in FIG. 2 to expose a port 76 so that sediment collected in the sump area 62 passes through port 76 to the clothes receptacle 11. Upon termination of the rotation of the spinning basket 50 during the extraction cycle, the valve 74 automatically reseats itself into liquid retaining engagement with the port 76.
Referring now to FIG. 3 in order to insure the sediment which flows into the sump areas 62 is retained therein there is provided a sump cover member 80. The cover member 80 includes an opening 82 having a downwardly circumferentially disposed lip 84. The downwardly extending lip 84 in conjunction with the sump area 62 acts as a trap to prevent sediment from returning to the basket 50 during the turbulent washing action.
It should be apparent to those skilled in the art that the embodiment described heretofore is considered to be the presently preferred form of this invention. In accordance with the Patent Statues, changes may be made in the disclosed apparatus and the manner in which it is used without actually departing from the true spirit and scope of this invention. | This invention relates to automatic clothes washing machines, and more particularly to an improved structure in such machines for affecting the washing of very small loads of clothing in a high detergent concentration. The clothes washing machine has wash, rinse and spin extraction operations including an outer imperforate tub, an agitator, a first basket within the tub, a second smaller basket disposed within the first basket and positioned on the agitator for movement therewith. There is also a water supply for feeding water into the machine, drive system for operating the agitator to effect washing of clothes and for rotating the basket to centrifugally extract water from the clothes. Water is allowed to flow from the basket to the tub and then recirculated through a filter and into the baskets. The recirculation system is controlled wherein only a predetermined volume of water is transferred from the outer tub to the small basket by the recirculation system. This allows clothes placed in the small basket to be washed in a high detergent concentration relative to the predetermined volume of water in the small basket and independent of the amount of water in the tub and to then be rinsed during continuous recirculation of water from the outer tub. The improvement comprising a system whereby the controlled volume of water in the small basket is recirculated through the filter while at the same time removing heavy soil from the water. | 3 |
BACKGROUND OF THE INVENTION
The present invention relates to a mobile telephone battery power supply unit which includes a power detection circuit controlled to detect the current power level of the rechargeable battery of the mobile telephone, and a discharge circuit controlled to discharge the residual voltage out of the rechargeable battery of the mobile telephone before each recharging operation so as to eliminate possible "memory effect". The mobile telephone battery power supply unit comprises a battery case fastened inside the housing thereof and covered by a slide cover, which battery case has batteries that keep providing a constant voltage to the mobile telephone for normal operation as the rechargeable battery of the mobile telephone fails.
A variety of mobile telephones are known and widely in use for the advantage of mobility. However, a mobile telephone must be frequently recharged so that the rechargeable battery of the mobile telephone can be constantly maintained at high level for normal operation. Because of the lack of a power detection means for automatically detecting the current power level of the rechargeable battery of the conventional mobile telephone, the user may forget to recharge the rechargeable battery before it turns to low level. Furthermore, the rechargeable battery of a conventional mobile telephone is generally a nickel-cadmium cell which tends to produce a "memory effect", more particularly after a long use, causing the rechargeable battery not to be fully recharged to the saturation state.
SUMMARY OF THE INVENTION
The present invention eliminates the aforesaid problems. It is therefore an object of the present invention to provide a mobile telephone battery power supply unit which can detect the current power level of the rechargeable battery of a mobile telephone. It is another object of the present invention to provide a mobile telephone battery power supply unit which can discharge the residual voltage out of the rechargeable battery of the mobile telephone before recharging it. It is another object of the present invention to provide a mobile telephone battery power supply unit which prolongs the service life of a mobile telephone. According to one aspect of the present invention, the mobile telephone battery power supply unit is consisted of a housing covered with a slide cover to hold an electronic circuit assembly and battery case on the inside, wherein the electronic circuit assembly includes a power detection circuit controlled to detect the current power level of the rechargeable battery of the mobile telephone to which it is connected, and a discharge circuit controlled to discharge the residual voltage out of the rechargeable battery of the mobile telephone before each recharging operation so as to eliminate possible "memory effect". According to another aspect of the present invention, the battery case receives alkaline batteries, which keep providing a constant voltage to the mobile telephone for normal operation as the rechargeable battery of the mobile telephone fails.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded view of a mobile telephone battery power supply unit embodying the present invention;
FIG. 2 is a plan assembly view thereof;
FIG. 3 illustrates that the mobile telephone battery power supply unit is to be fastened to a mobile telephone for charging its rechargeable battery; and
FIG. 4 is a circuit diagram of the mobile telephone battery power supply unit.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIGS. 1 and 2, a mobile telephone battery power supply unit as constructed in accordance with the present invention is generally comprised of a housing 1, an electronic circuit assembly 2, a battery case 3, and a cover 4. The housing 1 of the mobile telephone battery power supply unit comprises a plurality of recessed, paralleled, anti-skid stripes 60 over the front panel 13 thereof. There are also provided on the front panel 13 of the housing 1, a power-indication scale 131, a power detection control button 132, a discharge control button 133, and a plurality of contacts 12 respectively arranged at suitable locations. A socket 121 is made on the bottom end of the housing 1 and electrically connected to the contacts 12. By means of the socket 121, the mobile telephone power supply unit can be connected to an external power supply outlet. There is provided a semi-circular opening 16 on the top end of the housing 1, and a mount 11 on the inside adjacent to the bottom end thereof. The mount 11 comprises a retaining hole 112 on the top, two opposite grooves 111 on two opposite sides, and contacts 12 corresponding to the contacts 12 on the front panel 13 of the housing 1. The holding space of the housing 1 is divided by a division wall 14 into a storage chamber 15, which receives the electronic circuit board 21 and the battery case 3, and a retaining chamber 17, which receives the semi-circular plug portion 41 of the cover 4. The storage chamber 15 has a plurality of posts 151 spaced on the inside for mounting the electronic circuit assembly 2. The housing 1 further comprises two substantially L-shaped peripheral bottom edges 18 on two opposite sides. There are a plurality of inwards projecting strips 191 and retaining slots 19 at the peripheral edges 18 of both sides of the housing 1. The electronic circuit assembly 2 comprises a circuit board 21 having holes 211 at locations corresponding to the posts 151 on the housing 1. By inserting the posts 151 into the holes 211 respectively, the electronic circuit board 21 is firmly retained inside the rechargeable chamber 15. The circuit board 21 of the electronic circuit assembly 2 comprises a set of indicator lamps 22, a power detection micro-switch 23 and a discharge control micro-switch 24 at locations corresponding to the power-indication scale 131, the power detection control button 132 and the discharge control button 133 on the housing 1. The battery case 3 which fits into the rechargeable chamber 15 on the housing 1 comprises two parallel channels 31 in longitudinal direction on two opposite sides for receiving batteries, of which has two conductive elements 32 on two opposite ends. A thermoelement 33 is connected in series between two adjacent conductive elements 32. The thermoelement 33 automatically cuts off the circuit as the temperature surpassed a predetermined range (for example, 80° C.) during charging of the batteries. This arrangement protects the batteries from being excessively charged. The cover 4 has a circular plug portion 41 on one end inserted into the retaining chamber 17 between the semi-circular opening 16 and the division wall 14 on the housing 1, a unitary hook 43 on an opposite end hooked in the retaining hole 112 on the mount 11 of the housing 1, two symmetrical stepped flanges 42, 45 on two opposite sides, two retaining grooves 46 on two opposite sides between the respective stepped flanges 42, 45. Each stepped flange 42, 45 includes an upper flange 42 having a plurality of spaced notches 47, and the both sides of lower flange 45 having projecting strips 44 with retaining slots 441 at locations corresponding to the projecting strips 191 and the retaining slots 19 on the peripheral bottom edges 18 of both sides of the housing 1.
Referring to FIGS. 2 and 3 again, the circuit board 21 of the electronic circuit assembly 2 is fastened inside the storage chamber 15 of the housing 1 with the set of indicator lamps 22, the power detection micro-switch 23 and the discharge control micro-switch 24 respectively electrically connected to the power-indication scale 131, the power detection control button 132 and the discharge control button 133. Then, the battery case 3 is inserted into the storage chamber 15 with the other two separated conductive elements 32 of the parallel channels 31 (on the end opposite to the thermoelement 33) connected to the contacts 12 on the mount 11 of the housing 1. Finally, fasten the cover 4 to the housing 1 over the battery chamber 3 permitting the projecting strips 44 of the lower flanges 45 to hook up with the projecting strips 191 by inserting the projecting strips 44 into the retaining slots 19 and then move the projecting strips 44 to under the projecting strips 191 for combination, the hook 43 to hook in the retaining hole 112 on the mount 11 of the housing 1, and the semi-circular plug portion 41 to insert into the retaining chamber 17 on the housing 1. By means of the upper flanges 42, the mobile telephone power supply unit is fastened to a mobile telephone 5. When assembled, the antenna holder of the mobile telephone 5 is received in the semi-circular opening 48 on the, and the contacts 12 on the mount 11 of the housing 1 are respectively connected to the respective spring contacts on the mobile telephone to form into a closed circuit for providing the mobile telephone 5 with power supply.
Referring to the circuit diagram of present invention as shown in FIG. 4, the third and ninth pins of the driving circuit 50 are connected to an external voltage (reference voltage) which is connected to the positive terminals of the light emitting diodes (set of indicator lamps) 52. The negative terminals of the light emitting diodes 52 are respectively connected to the input terminal of the driving circuit 50. The sixth, seventh and fourth pins of the driving circuit 50 are connected in parallel and then connected to a resistor 53, the base of a n-p-n transistor 54 and the power detection micro-switch 23. The fifth pin of the driving circuit 50 is connected to the variable terminal of a variable resistor 58, which is connected to an external voltage to provide a constant voltage. The variable resistor 58 has an opposite end connected in parallel to the eighth and second pins of the driving circuit 50 and also connected to the resistor 53, the base of the n-p-n transistor 54 and the power detection micro-switch 23. The resistor 53 and the collector of the n-p-n transistor 54 are connected to the external voltage. The emitter of the n-p-n transistor 54 is connected to the positive terminal of a thyristor 55. The thyristor 55 has its gate pulse terminal connected to the external voltage via the discharge control micro-switch 24, and its negative terminal connected to an oscillator circuit 57 via a discharge circuit 56. The oscillator circuit 57 has its earth terminal connected to the negative terminal of one of the light emitting diodes 52 via a transistor (not indicated).
The driving circuit 50 does not work under normal conditions. However, switching on the power detection micro-switch 23 causes the driving circuit 50 to be electrically connected. Once the driving circuit 50 is electrically connected, the external voltage provided through the third and ninth pins of the driving circuit 50 is compared with the reference voltage at the fifth pin. The driving circuit 50 turns on most of light emitting diodes 52 as the external voltage surpassed the reference voltage (the number of the light emitting diodes 52 to be turned on is determined according to the extent of the external voltage surpassed the reference voltage). On the contrary, less number of the light emitting diodes 52 will be turned on. Therefore, the capacity of the electric energy of the batteries (the external voltage) is detected according to the number of the light emitting diodes 52 being turned on.
The rechargeable battery of a mobile telephone is generally of a nickel-cadmium cell which tends to produce a "memory effect", more particularly after a long use, causing a small amount of electric energy constantly maintained on the inside. Because of the "memory effect", a nickel-cadmium cell can not be recharged to the saturation state. This problem of "memory effect" is eliminated from the present invention by mean of the operation of the discharge circuit 56 and the oscillator circuit 57. Switching on the discharge control micro-switch 24 produces a voltage to the gate pulse terminal of the thyristor 55, causing the thyristor 55 to be electrically connected. Once the thyristor 55 was electrically connected, the residual voltage of the rechargeable battery of the connected mobile telephone is charged to the discharge circuit 56. The oscillator circuit 57 oscillate intermittently to produce a discharge cycle for the discharge circuit 56 permitting it to discharge intermittently. Therefore, the residual voltage of the rechargeable battery of the mobile telephone can be completely discharged. As indicated, the earth terminal of the oscillator circuit 57 is connected to the negative terminal of one of the light emitting diodes 52, therefore the light emitting diodes 52 flash according to the frequency of oscillation of the oscillator circuit 57. Once the residual voltage of the rechargeable battery of the mobile telephone has been completely discharged, the light emitting diodes 52 are stopped from flashing, and the rechargeable battery of the mobile telephone can be recharged again. The aforesaid arrangement completely eliminates the problem of "memory effect", and therefore the present invention greatly increases the capacity of a rechargeable battery and simultaneously prolongs its service life. | A mobile telephone battery power supply unit consisted of a housing covered with a slide cover to hold an electronic circuit assembly and battery case on the inside. The electronic circuit assembly includes a charging circuit controlled to recharge the rechargeable battery of a mobile telephone, a power detection circuit controlled to detect the current power level of the rechargeable battery of the mobile telephone, and a discharge circuit controlled to discharge the residual voltage out of the rechargeable battery of the mobile telephone before each recharging operation so as to eliminate possible "memory effect", which prohibits the rechargeable battery from being fully charged to the saturation state. The battery case receives alkaline batteries, which keep providing a constant voltage to the mobile telephone for normal operation as the rechargeable battery of the mobile telephone fails. | 8 |
BACKGROUND OF THE INVENTION
The invention relates to a fluted nozzle adapter that can be adapted to a conventional stud gun or other precussion tool for the purpose of aligning and positioning a penetrator needle in the gun combined with a shock absorber for the penetrator needle slug and an energy absorber for the penetrator needle.
It has become common in construction work and in sampling work to use powder actuated tools for driving fasteners and penetrators into a work piece or container or the like.
It has been common to shoot the penetrator or stud in free flight in the direction of the target, work piece or container to be sampled. Such a method required the varying of the levels of energy input into the penetrator or stud to match the penetration energy required to penetrate the target material. Information as to energy levels as well as the thickness of target materials, the hardness of target materials is not likely to be known to operators in the field. This is particularly true because the target material may vary widely in thickness, hardness and other characteristics.
In actual practice many problems may be encountered including overpenetration, under penetration, needle or stud fracture, target deformation and improper seal of the opening in the penetrator needle.
SUMMARY OF THE INVENTION
In view of the foregoing it is the main object of this invention to provide an adapter that ofters precise control of the direction and penetration of a sampling needle or other projectile shot from a convention stud gun.
Another object of the invention is to provide an adapter assembly for a stud gun or other powder driven guns wherein the projectile or penetrator from the stud gun penetrates a target to a precise depth without any determination of target thickness, hardness or other variable.
An additional object of the invention is to provide a device for sampling toxic and dangerous chemical wherein the penetrator extends into the container to a predetermined depth without trial and error attempts.
It is one other important objective to provide an apparatus that supports the extension of the penetrator along the column and provides control over the penetration depth.
It is one further object of the invention to provide an adapter assembly with a penetrator that eliminates overpenetration and underpenetration.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing features and other details of the invention will now be more particularly described in connection with an illustrative embodiment and with reference to the accompanying drawings in which:
FIG. 1 is a perspective view of the adapter with the assembly of parts illustrated in sequential order.
FIG. 2 is a side elevation of the adapter with parts assembled in a ready to shoot position.
FIG. 3 is a cross section of the assembly shown in 2.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In FIG. 1 the cylindrical outer wall 10 of the adapter is fitted with a number of pivoted retaining arms 11. The pivoted arms 11 swing forward to fit, in shooting position into slots 12. The slots 12 surround the cylindrical bore 13 that extends throughout the length of the adapter from the forward end 14 through the rearward end 15 that may be screwed or clamped to the forward end of the stud gun or other powder actuated tool. In FIG. 1 the central bore 13 is packed prior to shooting with, in order, the piston 15, the penetrator needle 16, a penetrator carrier guide means 17, the first shock absorber 18 that strips the carrier from the penetrator and the shock absorber or energy arrestor 19 that is after shooting fastened to the work piece or target by the penetrator.
In FIG. 1, the assembly is first put into the bore 13 by placing the expended base 20 of the penetrator 16 into a slot 21 in the forward face of the piston 15.
A shoulder 22 is provided near the midsection of the piston. In the assembled position the base 23 of the carrier or guide 17 rests on and is supported by shoulder 22. The piston head or face 24 is actuated by the gases developed by fixing the gun and is the means by which the hollow penetrator needle, stud or other projectile 16 is driven into the work piece, container or target.
In the assembly the carrier 17 is placed over and around the penetrator 16 by the opening 25 being fitted around the outer shaft of the penetrator 16.
The subassemblly of the piston 15, penetrative 16 and the carrier 17 are then placed into the bore 13 of the adapter 10. The outer diameter of the carrier 17, that is usually made of plastic soft metal or other equivalent material, should fit snugly within the bore 13 of the adapter. The first shock absorber 18 that also serves the function of stripping off the slug, carrier or guide element 17 is usually made of wood, soft plastic or other soft energy absorbing frangible material.
Shock absorber 18 has a cylindrical opening throughout its thickness that it varies from about 1/100 to 1/8 of an inch smaller than the diameter of the penetrator 16.
The shock absorber 19, that is usually made of a metal of hardness similar to penetrator 16 has a shoulder 27 around its entire circumference that is in shooting position engaged by the clamping extention 28 on the inner face of each pivoted arm. An opening 29 is provided through the entire thickness of the shock absorber 19. This opening is initially equal to or smaller than the diameter of the penetrator 16.
After the assembly is positioned in the adapter 10 the pivoted arms 11 with extension 28 fit over the shoulder 27 so as to secure the assembly device in position.
Other multiple pivoted means may be used and are functionally equivalent to the multiple pivoted arms shown in FIGS. 1 and 2.
After shooting the forward face 30 of shock absorber 19 is held tightly against the by the penetrator 16.
A retaining ring 31 may be used to hold the pivoted arms 11 in position during the shooting of the penetrator.
FIG. 2 shows the assembled adapter mounted on gun 33, with openings 32 in the side wall of the adapter that communicates with the firing chamber and allow gases to escape after the penetrator has engaged the target or work piece.
In FIG. 3, in cross section screw threads 34 are shown as the means of fastening the adapter 10 to the gun 33. The penetrator 16 is shown in FIG. 3 as a hollow member with an opening 35 running the entire length thereof.
Pivot post 32 are shown in FIG. 3 as the means of pivoting arms 11 into position.
It desirable that the second shock absorber be made of a metal that is of a hardness essentially equal to the hardness of the penetrator.
Obviously, numberous 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 specifically described herein. | A penetrator interface adapter comprising a generally cylindrical fluted oilless nozzle adapter with means for positioning a penetrator with holder and an energy absorbing collar adjacent the target container so that the penetrator projects into the target or into the container to a predetermined point during each shot. | 1 |
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of our application Ser. No. 119,023 filed Feb. 6, 1980 now abandoned, which in turn is a continuation of our application Ser. No. 918,605 filed June 23, 1978 and now abandoned.
BACKGROUND OF THE INVENTION
This invention relates to an apparatus and method for converting an analog input voltage signal into a digital signal.
Generally, an analog-digital converter (hereinafter referred to as "an A-D converter") is not used alone, but as an attachment to a data-processing unit of a computer. The reason is that the data-processing unit carries out arithmetic operation, using signals digitalized by an A-D converter. The A-D converter acting as an attachment to the data-processing unit performs A-D conversion upon receipt of an instruction for said conversion from the data-processing unit. Hitherto, all hardware for A-D conversion has been included in the A-D converter itself, tending to increase its cost. In recent years, it is demanded to reduce the cost of all types of machinery. Thus it has become necessary for the A-D converter, too, to meet such request.
In view of the above-mentioned circumstances, this invention is intended to provide an A-D converter including a method for A-D conversion which comprises a voltage-time period converter (hereinafter referred to as "a V-T converter") in which the voltage level of an analog input voltage signal and the time period of an oscillated output signal have a linear relationship, and wherein an interruption request is made in proper timing to a data-processing unit of a computer system, causing said unit to take over part of the function of A-D conversion hardware in order to decrease the cost of the A-D converter.
SUMMARY OF THE INVENTION
It is accordingly an object of this invention to provide a method of A-D conversion using a V-T converter.
Another object of the invention is to provide a method of A-D conversion in which part of the function of A-D conversion hardware is taken over by the data-processing unit of a computer system.
Still another object of the invention is to provide a method of A-D conversion using a V-T converter and the data-processing unit of a computer system.
Still another object of the invention is to provide an A-D converter the cost of which is low.
Another object of the invention is to provide an A-D converter which includes a V-T converter.
A further object of the invention is to provide an A-D converter which includes the data-processing unit of a computer system.
A still further object of the invention is to provide an A-D converter which includes a V-T converter and the data-processing unit of a computer system.
To attain the objects mentioned above, this invention provides an A-D converter for converting into a pulse train an analog input voltage signal from a signal source which is to be measured. The A-D converter comprises the following elements:
(1) first signal means for providing a first analog input voltage signal of a first fixed level V L ;
(2) second signal means for providing a second analog input voltage signal of a second fixed level V H which is higher than said first fixed level V L ;
(3) multiplexer means connected to said signal source, said first signal means and said second signal means for receiving the signals therefrom and supplying the signals selectively and successively;
(4) a V-T converter connected to said multiplexer means for converting a selected one of the analog input voltage signal to be measured and the first and second analog input voltage signals into a pulse train signal having a period linearly proportional to the voltage level of the selected analog input voltage signal;
(5) a memory for storing instruction programs used for A-D conversion;
(6) a central processing unit;
(7) a first counter connected to said V-T converter to count the number of pulses of said pulse train signal issued from said V-T converter, said first counter also being connected to an external bus and loaded with a specific value through the external bus from the central processing unit;
(8) a clock pulse generator producing clock pulses of fixed period;
(9) a second counter connected to said clock pulse generator to continue counting the number of said clock pulses issued from said clock pulse generator during the time interval when said first counter continues counting, said second counter being also connected to the external bus, through which the contents of said second counter is to be read by the central processing unit; and
(10) control means operable to issue an enabling signal for controlling the start and stop of counting of said first and second counters such that when counting is stopped, the contents of said second counter represents a time interval during which said first counter counts out said specific number of pulses issued from said V-T converter, said control means operable to supply an interrupt signal to the central processing unit when said first counter counts out the number of pulses equal to said specific value loaded through the external bus from the central processing unit.
The central processing unit comprising an internal bus, register means including a program counter and connected to said internal bus, at least one accumulator connected to said internal bus for storing data, an arithmetic logic unit connected to said internal bus and said at least one accumulator and for performing an arithmetic calculation on the basis of the data stored in said register means and said at least one accumulator, an interrupt control connected to said control means for receiving an interrupt signal therefrom to control the start of an interrupt program, a buffer for connecting said external bus to said internal bus, and a bus control connected to said buffer for generating control signals required to perform data transfer, by way of said external and internal buses, between said multiplexer means and first and second counters, and between those circuits in said central processing unit which are connected to said internal bus, said arithmetic calculation being indicated by the following equation:
M=(n.sub.M -n.sub.L)/(n.sub.H -n.sub.L)×2.sup.n
where,
M is the digital value of the unknown voltage level V M of the analog input voltage signal to be measured,
2 n is a full scale of the converted digital value,
n L is the contents of said second counter which represents the time interval during which said first counter counts out said first specific number of pulses under the condition that said first analog input signal of said first voltage level V L is selected as the input signal to said V-T converter,
n H is the contents of said second counter which represents the time interval during which said first counter counts out said specific number of pulses under the condition that said second analog input signal of said second voltage level V H is selected as the input signal to said V-T converter, and
n M is the contents of said second counter which represents the time interval during which said first counter counts out said specific number of pulses under the condition that said analog input signal of said unknown voltage level V M is selected as the input signal to said V-T converter.
This invention further provides an A-D conversion method using a V-T converter wherein the voltage level of an input signal and the time period of an oscillated output signal have a linear relationship, and comprising the steps of:
(A) loading a first counter with a specific value,
(B) supplying a first analog input voltage signal of a first voltage level V L to said V-T converter,
(C) counting, by said first counter, first pulses issued from said V-T converter which correspond to the voltage level V L of the first analog input voltage signal until the number of pulses counted by said first counter has come to said specific value,
(D) counting, by a second counter, clock pulses issued from a clock pulse generator while said first counter counts first pulses from said V-T converter,
(E) loading the number n L of clock pulses counted by said second counter into a central processing unit,
(F) loading said first counter with said specific value;
(G) supplying a second analog input voltage signal of a second voltage signal V H to said V-T converter,
(H) counting, by said first counter, second pulses issued from said V-T converter which correspond to the voltage level V H of the second analog input voltage signal until the number of pulses counted by said first counter has come to said specific value,
(I) counting, by said second counter, clock pulses issued from the clock pulse generator while said first counter counts second pulses from said V-T converter,
(J) loading the number n H of clock pulses counted by said second counter into said central processing unit,
(K) loading said first counter with said specific value,
(L) supplying an analog input voltage signal of an unknown voltage level V M l to be measured to said V-T converter,
(M) counting, by said first counter, third pulses issued from said V-T converter which correspond to the unknown voltage level V M of the analog signal to be measured until the number of pulses counted by said first counter has come to said specific value,
(N) counting, by said second counter, clock pulses issued from the clock pulse generator while said first counter counts third pulses from said V-T converter,
(O) loading the number n M of clock pulses counted by said second counter into said central processing unit, and
(P) carrying out the equation
M=(n.sub.M -n.sub.L)/(n.sub.H -n.sub.L)×2.sup.n
by the central processing unit to calculate the digital value M converted from the unknown voltage level V M on the basis of the pulse information stored in the central processing unit where, 2 n is a full scale of the converted digital value.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block circuit diagram of a V-T converter included in an A-D converter embodying this invention;
FIG. 2 indicates the waveforms of output signals corresponding to various voltage levels of signals which are supplied to the V-T converter of FIG. 1;
FIG. 3 is a curve diagram of the relationship between the voltage level of an analog input signal supplied to the V-T converter of FIG. 1 and the time period of an output oscillated signal;
FIG. 4 is a block circuit diagram of an A-D converter embodying this invention;
FIG. 5 sets forth the concrete arrangement of a control circuit in the A-D converter of FIG. 4;
FIGS. 6A to 6G collectively constitute a timing chart illustrating the operation of the A-D converter of FIG. 4;
FIG. 7 shows the relationship between the voltage level of an analog input signal supplied to the V-T converter of FIG. 1 and the time period of an output oscillated signal;
FIG. 8 sets forth a block circuit diagram of a central processing unit in the A-D converter of FIG. 4;
FIG. 9 is a block circuit diagram of an A-D converter according to another embodiment of this invention; and
FIGS. 10A to 10E jointly denote a timing chart of the A-D converter of FIG. 9.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
There will be first described by reference to FIG. 1 a V-T converter in which the voltage level of an analog input voltage signal and the time period of an output oscillated signal have a linear relationship.
Referential numeral 12 denotes an operation amplifier, whose noninverting terminal ("+" terminal) is supplied with an analog input voltage signal V x . The inverting terminal ("-" terminal) of the amplifier 12 is connected to a power source (not shown) having a voltage V CC through a resistor 14 having a resistance R. The potentials of both inverting and noninverting terminals vary to the same extent. The emitter of the transistor 16 is connected to the above-mentioned power source through the resistor 14, and the collector of said transistor 16 is grounded through a capacitor 18 having a capacity C. The base of the transistor 16 is connected to the output terminal of the amplifier 12. Where the transistor 16 is operated by an output signal from the amplifier 12, then current running through the collector-emitter path of the transistor 16 is charged in the capacitor 18. The inverting terminal of a comparator 20 is connected to a junction between the collector of the transistor 16 and the capacitor 18. The noninverting terminal of the comparator 20 is supplied with an analog input voltage signal V y . The output terminal of the comparator 20 is connected to a discharge control circuit 22. When supplied with an output signal from the comparator 20, the discharge control circuit 22 causes electric charge stored in the capacitor 18 to be discharged. The aforesaid power source having a voltage V CC , resistor 14 and operational amplifier 12 jointly constitute a constant current source. The constant current source is in an optimum condition when the following equation results where the comparator 20 produces an output signal having a logic level of "1"
V.sub.y =(V.sub.CC -V.sub.x)/RC·T
where T denotes the time period of an output oscillated signal.
The V-T converter of FIG. 1 is operated in the following two ways. A first process is to fix an analog input voltage signal V x and vary another analog input voltage signal V y so as to render the signal V y proportional to T. A second process is to fix the analog input voltage signal V y and vary the analog input voltage signal V x to obtain a result expressed by the following formula:
(V.sub.CC -V.sub.x)∝T.sup.-1 ≡f (1)
where f represents the frequency of an output signal.
FIG. 2 shows the waveform of an output signal obtained by the first process, namely, when the analog voltage signal V y is rendered variable. The output signal is drawn off from an output terminal OUT. Where the voltage signal V y consists of a signal V y1 , then the output signal has a time period T 1 . Where the voltage signal V y is formed of a signal V y2 , then the output signal has a time period T 2 . Namely, the output signal has a time period T corresponding to the voltage level of the analog input voltage signal V y . The circuit of FIG. 1 is operated as a V-T converter.
FIG. 3 is a curve diagram showing the relationship between the voltage level of an input voltage signal to the V-T converter and the time period of an output oscillated signal, indicating that said relationship has a linear pattern. Where the V-T converter of FIG. 1 displaying the above-mentioned linear relationship is used and an interruption request is made in proper timing to a data-processing unit of a computer system, then it is possible to let said data-processing unit take over part of the function of the hardware of the A-D converter, thereby reducing the cost of the A-D converter.
FIG. 4 is a block circuit diagram of an A-D converter including the V-T converter of FIG. 1 and the data-processing unit of the computer system. There will now be described the respective blocks of FIG. 4. An external ROM (Read Only Memory) 41 stores instruction programs therein used for A-D conversion. A multiplexer (MUX) 42 selects any of the channels of analog input voltage signals. The multiplexer (MUX) 42 is supplied with a signal having a high prescribed voltage level V H , a signal having a low referential voltage level V L and a plurality of input voltage signals having voltage level V M1 to V Mi (i denotes a given natural number) which are to be measured. The multiplexer (MUX) 42 detects the contents of a channel-selecting signal delivered from the data-processing unit of the computer system and selects the corresponding channel of an input voltage signal. The multiplexer (MUX) 42 sends forth the selected voltage signal to a V-T converter 46 disposed on the output side of the multiplexer 42. The V-T converter 46 converts an analog input voltage signal into a pulse train signal having a period linearly proportional to the voltage level of the analog input voltage signal. The input terminal of the V-T converter 46 constitutes the noninverting terminal of the comparator 20 with respect to the V-T converter of FIG. 1. The output terminal of the V-T converter 46 represents a junction between the transistor 16 and capacitor 18. A latch circuit 47 holds an output signal from a data-processing unit or central processing unit (CPU) 44 which selects any of the voltage signal channels of the multiplexer (MUX) 42. A first input terminal of a first AND gate 48 is supplied with an output pulse from the V-T converter 46. While a second input terminal of the first AND gate 48 is supplied with an enable signal EX from a control circuit 50, an output pulse from the V-T converter 46 is conducted to a first counter 52. A number N of pulses from the V-T converter 46 being counted by the first counter 52 is preset therein from the data-processing unit 44 through an external data bus 54. The preset number N is decreased by one bit, each time a pulse is supplied through the first AND gate 48 from the V-T converter 46. A first input terminal of a second AND gate 56 is supplied with a clock pulse CL from a clock pulse generator 58. While an enable signal EX is supplied from the control circuit 50 to a second input terminal of the second AND gate 56, the clock pulse CL is carried to a second counter 60 through said second AND gate 56. The clock pulse CL is desired to have a stable frequency. To this end, the clock pulse generator 58 should preferably consist of a timing clock pulse source (not shown) included in the data-processing unit 44. The second counter 60 counts clock pulses CL delivered through the second AND gate 56.
After a preset number N being counted is preset in the first counter 52, the fall of the initial output pulse issued from the V-T converter 46 is detected. An enable signal EX is sent forth in synchronization with said initial clock pulse CL. Further, the A-D converter of FIG. 4 may be so arranged as to cause an enable signal EX to be produced in synchronization with the detection of the rise of the initial output pulse from the V-T converter 46. When the count made by the first counter 52 is reduced to zero by subtraction the supply of an enable signal EX from the control circuit 50 is stopped. At this time, this control circuit 50 sends forth an interruption instruction INT to the data-processing unit 44. Upon receipt of the interruption instruction INT, a count made by the second counter 60 up to this point is stored in the internal registers of the data-processing unit 44. The registers are normally supplied with a count n H made by the second counter 60 upon receipt of a signal having a high prescribed voltage level V H , a count n L made by said second counter 60 upon receipt of a signal having a low referential voltage level V L , and counts n M1 to n Mi made by said second counter 60 upon receipt of analog input voltage signals having voltage levels V M1 to V Mi . The data-processing unit 44 carries out logic operation according to the counts n H , n L , n M1 to n Mi , and produces data derived from A-D conversion of analog input voltage signals having voltage levels V M1 to V Mi which are to be measured. On other occasions than A-D conversion, the data-processing unit 44 acts as the central processing unit (CPU) of the computer system which undertakes operation relative to other jobs.
There will now be described by reference to FIG. 5 the arrangement of the control circuit 50. This control circuit 50 comprises a first flip-flop circuit 82 whose set terminal S receives a preset signal from the data-processing unit 44; an inverter 84 which inverts the phase of an output pulse from the V-T converter 46; an AND gate 86 whose first input terminal receives an output pulse from the V-T converter 46, and whose second input terminal receives an output signal from the output terminal Q of the first flip-flop circuit 82; a second flip-flop circuit 88 whose set terminal S receives an output pulse from the AND gate 86, and whose output terminal Q generates an enable signal EX; an AND gate 90 whose first input terminal receives an output enable signal EX from the second flip-flop circuit 88, and whose second input terminal receives an output clock pulse from the clock pulse generator 58; a NAND gate 92 which receives a plurality of bit signals from the first counter 52 which represent a number preset in said counter 52, and generates a signal which acts as a reset signal for both first and second flip-flop circuits 82, 88 and also as an interruption instruction for the data-processing unit 44; and an AND gate 94 whose first input terminal receives an output signal from the NAND gate 92, and whose second input terminal receives an output clock pulse from the clock pulse generator 58.
The respective blocks of the A-D converter have been briefly outlined by reference to FIG. 4. There will now be described the operation of the entire A-D converter by reference to the timing chart of FIGS. 6A to 6G and the V-T characteristic curve of the V-T converter 46 shown in FIG. 7.
First, channel-selecting data (FIG. 6A) is sent forth from the data-processing unit 44 through the latch circuit 47 to the multiplexer 42. The multiplexer 42 selects the channel of a voltage signal corresponding to the contents of said channel-selecting data. The voltage signal of the selected channel is delivered to the V-T converter 46. An output pulse (FIG. 6B) from the V-T converter 46 is supplied to the first input terminal of the first AND gate 48 and also to the inverter 84 of the control circuit 50. A signal whose phase has been inverted by the inverter 84 is conducted to the first input terminal of the AND gate 86. A value N (FIG. 6C) being preset in the first counter 52 is supplied from the data-processing unit 44 through the bus 54. At this time, the data-processing unit 44 delivers a set signal through the port 130 to the set terminal S of the first flip-flop circuit 82 of the control circuit 50, causing a signal having a logic level of "1" to be produced from the output terminal Q of the first flip-flop circuit 82. Said "1" level signal is carried to the second input terminal of the AND gate 86. As previously described, an output pulse from the V-T converter 46 is already supplied to the first input terminal of the AND gate 86 through the inverter 84. When, therefore, a fall arises in the first pulse delivered from the V-T converter 46 after the supply of a preset signal to the first counter 52, then the AND gate 86 issues a signal having a logic level of "1". This "1" level signal is conducted to the set terminal S of the second flip-flop circuit 88, whose output terminal Q generates a signal having a logic level of "1". This "1" level signal acts as an enable signal EX (FIG. 6D) for the first and second counters 52, 60. The enable signal EX is delivered to the first input terminal of the AND gate 90 whose second input terminal receives a clock pulse (FIG. 6E) from the clock pulse generator 58. The enable signal EX is supplied to the first and second counters 52, 60 in synchronization with the clock pulse CL. Upon receipt of the enable signal EX, the first AND gate 48 is opened to cause an output pulse from the V-T converter 46 to be sent forth to the first counter 52. When supplied with the enable signal EX, the second AND gate 56 is opened to allow a clock pulse CL issued from the clock pulse generator 58 to be carried to the second counter 60. A count made by the first counter 52 is decreased by 1 bit, each time an output pulse from the V-T converter 46 is received (FIG. 6C). A count made by the second counter 60 is increased by 1 bit, each time a clock pulse CL is received (FIG. 6F). The respective bit signal lines extend from the first counter 52 to the NAND gate 92 of the control circuit 50. While a value N is preset in the first counter 52, signals of bit lines thereof have a logic level of "1". When the contents of the first counter 52 are reduced to zero by subtraction, the signals of all the bit lines of said counter 52 have the logic level changed to "0", causing the NAND gate 92 to produce an output signal having a logic level of "1". This "1" level signal is supplied to the reset terminal R of the first and second flip-flop circuits 82, 88, thereby preventing the issue of an enable signal EX from the second flip-flop circuit 88, and stopping the operation of the second counter 60. When synchronized with a clock pulse CL delivered from the AND gate 94, a "1" level output signal from the NAND gate 92 acts as an interruption instruction (FIG. 6G). Upon receipt of this interruption instruction, the data-processing unit 44 sends forth a fresh channel-selecting data to the multiplexer 42 through the latch circuit 47 to change over the channel of said multiplexer 42. A count made by the second counter 60 up to this point is stored in the register of the data-processing unit 44.
When the channel of the multiplexer 42 has thus been shifted, the above-mentioned operation cycle is commenced again, starting with the presetting of a value N in the first counter 52. Where such operation cycle is carried out with respect to a voltage signal having a high prescribed voltage level V H , a voltage signal having a low referential voltage level and analog input voltage signals being measured which have different voltage levels V Ml to V Mi , then the second counter 60 makes the corresponding counts n H , n L and n M . Now assuming that the clock pulse has a frequency of 1.28 MHz, then the time period T of an output signal from the V-T converter 46 may be expressed by the following general formula: ##EQU1## As apparent from the later given fractional equation, the term of N and the term of 0.78125 can be deleted. Therefore, it is practically unnecessary to carry out the division of 0.78125/N.
The V-T characteristic of the V-T converter 46 (relationship between the voltage level of an input signal and the time period of an oscillated output signal) can be represented by a linear curve shown in FIG. 2. Now let it be assumed that T H denotes the time period of an output signal from the V-T converter 46 when a signal having a high prescribed voltage level V H is supplied; T L said time period when a signal having a low reference voltage level V L is introduced; and T M said time period when analog input signals having different voltage level V Ml to V Mi are received. Then relationship between the voltage levels V H , V L , V Ml to V Mi of the input signals and the corresponding time periods of output signals from the V-T converter 46 takes a pattern illustrated in FIG. 7. Therefore, A-D converted data M on the different voltage levels V Ml to V Mi of input signals may be determined from the following equation (3): ##EQU2##
With the low referential voltage level V L taken to be zero, there results:
(V.sub.H -V.sub.L)=V.sub.H
Now assuming that the high prescribed voltage level V H is a maximum value taken by an analog input voltage signal being measured which is supplied to the V-T converter 46, and said maximum voltage level is expressed, for example, as 2 n (n represents a bit number), then the A-D converted data M may be determined from the following fractional equation: ##EQU3## Calculation of the above equation (4) is carried out by the data-processing unit 44.
The counts n H , n L , n M of the second counter 60 corresponding the voltage levels of input signals V H , V L , V Ml to V Mi are stored in the internal registers of the data-processing unit 44. Therefore, the counts n H , n L , n M can be easily read out in carrying out the calculation of the above equation (4).
The data-processing unit or CPU 44 has such a structure as shown in FIG. 8. As FIG. 8 shows, a buffer 112 connects the external bus 54 to an internal bus 114. To the buffer 112 a bus controller 116 is connected for controlling the data transfer between the external bus 54 and the internal bus 114. General registers GR0 to GR7 (not shown), or internal registers 118, are connected to the internal bus 114. The general register GR0 is used as a program counter, and the general register GR1 is used as a program status word counter. The general register GR2 temporarily stores a preset value N which is read out from the external ROM 41 and which is to be supplied to the first counter 52. The general registers GR3, GR4 and GR5 temporarily store count contents n H , n L and n M supplied from the second counter 60, respectively. In response to a control signal (a read instruction) from a microprogram read only memory (ROM) 120 the general register GR2 supplies the preset value N to the first counter 52 through the internal bus 114 and the external bus 54.
To the internal bus 114 an accumulator (ACC1) 122 and an accumulator (ACC2) 124 are connected. Count contents n H , n L and n M are read out from the general registers GR3, GR4 and GR5 and supplied through the internal bus 114 to the ACC1 122 and the ACC2 124. The ACC1 122 and the ACC2 124 temporarily store count contents n H , n L and n M . Using count contents n H , n L and n M stored in the ACC1 122 and the ACC2 124, an arithmetic logic unit (ALU) 126 performs arithmetic operation which is given by equation (4). The result of the operation is stored into any of the general registers GR3 to GR5 through the internal bus 114.
To the internal bus 114 an instruction register 128 is connected. The instruction register 128 temporarily stores instructions read from the external ROM 41. To the instruction register 128 the microprogram ROM 120 is connected which functions as an instruction decoder. The microprogram ROM 120 decodes the instruction read from the instruction register 128. The output data from the microprogram ROM 120 is supplied to the CPU 44 and controls a port 130, an interrupt control 132, a bus control 116, the ACC1 122, the ACC2 124, the ALU 126, and the general registers 118. The microprogram ROM 120 is connected to these components of the CPU 44 by signal lines (not shown).
The port 130 is connected to the internal bus 114 and supplies a set signal to the set terminal S of the first flip-flop 82 of the control circuit 50, under the control of a control signal from the microprogram ROM 120. The CPU 44 further comprises a timing signal generator 134 which functions as a timing controller and generates clock pulses at predetermined intervals. A clock pulse from the timing signal generator 134 is supplied to the port 130, the interrupt control 132, the bus control 116, the ACC1 122, the ACC2 124, the ALU 126 and the general registers 118. The timing signal generator 134 is connected to these components by signal lines (not shown). In FIG. 8 address signals used are not shown, thus making the figure simple.
To perform A-D conversion the CPU 44 operates in the following way.
An A-D conversion instruction program is composed of a main instruction program and an interrupt instruction program. The main instruction program is read from the external ROM 41 and stored into the instruction register 128. It is then read out of the instruction register 128 and decoded by the microprogram ROM 120. The first instruction contained in the main instruction program designates a channel the multiplexer 42 will select, e.g. a high voltage V H channel. By executing this instruction, a channel selecting data is supplied to the latch circuit 47. The multiplexer 42 selects the channel designated by the data latched by the latch circuit 47. The second instruction contained in the main instruction program instructs the presetting of preset value N to the counter 52. According to the second instruction, preset value N is preset to the counter 52. The third instruction contained in the main instruction program designates the setting of the first flip-flop 82 of the control unit 50. According to the third instruction, the port 130 delivers a set signal to the set terminal S of the first flip-flop 82 of the counter unit 50. Hence, the second counter 60 counts the clock pulses from the clock pulse generator 58 while the first counter 52 is counting N output pulses from the V-T counter 46. When the first counter 52 finishes counting N output pulses, the AND gate 94 of the control circuit 50 produces an interrupt signal. The interrupt signal is supplied to the interrupt control 132 of the CPU 44. Upon receipt of the interrupt signal the interrupt control 132 stops the execution of the main instruction program and begins the execution of the interrupt instruction program. As a result of the interrupt service program execution, the count of the second counter 60, e.g. count content n H , is stored into the general register GR3 through the buses 54 and 114.
The sequence of steps described above is repeated, whereby other channels are designated one after another, the second counter 60 counts clock pulses while the first counter 52 is counting N output pulses from the V-T converter 46, thus delivering count contents n L and n M , and these count contents n L and n M are stored into the general registers GR4 and GR5, respectively.
When all the counter contents n H , n L and n M are stored into the general registers GR3, GR4 and GR5, respectively, they are supplied, one by one, selectively to the ACC1 122 and the ACC2 124 and temporarily stored in the ACC1 122 and the ACC2 124. Using the count contents n H , n L and n M stored selectively in the ACC1 122 and the ACC2 124, the ALU 126 performs the arithmetic operation of equation (4) in accordance with the main instruction program read from the external ROM 41. More precisely, the arithmetic operation is carried out in the following manner.
First, count contents n M and n L are read from the general registers GR5 and GR4, respectively, and are then stored into the ACC1 122 and the ACC2 124, respectively, through the internal bus 114. The ALU 126 then performs subtraction (ACC1-ACC2), i.e. (n M -n L ). The difference obtained is stored into, for example, the general register GR5 through the internal bus 114. Thereafter, count contents n H and n L are read from the general registers GR3 and GR4, respectively, and are then stored into the ACC1 122 and the ACC2 124, respectively, via the internal bus 114. The ALU 126 performs subtraction (n H -n L ). The difference obtained is stored into, for example, the general register GR3. This done, the difference (n M -n L ) is read from the general register GR5 and stored into the ACC1 122 and the ALU 126 performs multiplication of (n M -n L )×2 n . The product thus obtained is stored into the general register GR5. The product is read from the general register GR5 and stored into the ACC1 122, and the difference (n H -n L ) is read from the general register GR3 and stored into the ACC2 124. The ALU 126 divides (n M -n L )×2 n by (n H -n L ). The quotient thus obtained is an A-D converted data.
The A-D converter of this invention arranged as described above have the advantages that part of the function of hardware is taken over by the data-processing unit or CPU 44 of a computer system, thereby decreasing the amount of hardware by that extent and in consequence reducing the cost of hardware; a value N being preset in the first counter 52 can be freely chosen by a program in conformity to the demanded precision of A-D conversion or the required frequency stability of a clock pulse; the voltage levels of input signals can be measured in any optional order; the counts n H , n L of the second counter 60 corresponding to the high prescribed voltage levels V H and low referential voltage level V L can be used in common in determining the A-D converted data on the different voltage levels V Ml to V Mi of the analog input signals being measured; since errors in the A-D conversion do not arise from the low precision of the frequency of an output signal from the V-T converter 46 but from the low precision of the frequency of a clock pulse CL, the stabilization of the frequency of the clock pulse CL can elevate the precision of the A-D conversion; and consequently it is relatively easy to manufacture an A-D converter with high precision. Where clock pulses CL are counted for long by the second counter 60 with the first counter 52 preset at a larger N value, then the effect of noises on the A-D converted data is homogenized, thereby decreasing errors in said data.
This invention is not limited to the foregoing embodiment. Where the data-processing unit 44 is provided with a clock pulse counter, then said counter may replace the second counter 60. Further, the control circuit 50, first AND gate 48, second AND gate 56, etc. may be incorporated in the data-processing unit 44.
FIG. 9 represents an embodiment using a V-T converter causing an output pulse to be issued at a relatively long interval. Application of such V-T converter only requires a single counter.
FIGS. 10A to 10E jointly constitute a timing chart for the respective sections of the A-D converter of FIG. 9. FIG. 10A shows the waveform of an output signal from the V-T converter. FIG. 10B indicates the waveform of an output enable signal EX from the control circuit. FIG. 10C denotes clock pulses CL. FIG. 10D indicates the contents of a counter. FIG. 10E illustrates the waveform of an interruption instruction delivered from the control circuit.
There will now be described the operation of the A-D converter of FIG. 9 by reference to the timing charts of FIGS. 10A to 10E. The parts of FIG. 9 the same as those of the A-D converter of FIG. 4 are denoted by the same numerals, description thereof being emitted.
According to the embodiment of FIG. 9, an output signal (FIG. 10A) from a V-T converter 100 is supplied to a control circuit 50. The logic level of an output enable signal EX (FIG. 10B) from the control circuit 50 changes to "1" in synchronization with the fall of an initial output pulse from the V-T converter 100, and to "0" in synchronization with the fall of a second output pulse from said control circuit 50. A clock pulse (FIG. 10C) is supplied to the first input terminal of the AND gate 56. An enable signal EX is conducted to the second input terminal of the AND gate 56. While the second input terminal of the AND gate 56 is supplied with an enable signal having a logic level of "1", a clock pulse passes the AND gate 56. A counter 60 counts a number of clock pulses conducted through the AND gate 56 (FIG. 10D). Where the enable signal EX is extinguished, namely, has a logic level of "0", then the counter 60 ceases counting. At this time, the control unit 50 sends forth an interruption instruction (FIG. 10E) to the data-processing unit 44, causing the contents of the counter 60 to be stored in the register of the data-processing unit 44. The channel of the multiplexer 42 is shifted, and the previously-described processing cycle is carried out with respect to a fresh input voltage signal. Thus the counter 60 makes a count corresponding to the voltage levels V H , V L , V M of the respective input signals. A-D converted data on these voltage levels V H , V L , V M is calculated by the data-processing unit 44. With the embodiment of FIG. 9, the time period of pulses issued from the V-T converter 100 is counted by clock pulses, making it unnecessary to provide a counter 52. Since pulses are generated at a long interval, errors in the A-D converted data on the respective voltage levels are reduced, because a large number of clock pulses can be counted during said interval.
The foregoing embodiments relate to the A-D converter provided with the V-T converter. The time period T and frequency f of an input signal have a relationship of T=1/f, namely the time period T is a reciprocal of the frequency f. Therefore, the V-T converter described herein should be construed to include a voltage-frequency converter (V-F converter). | An A-D converter for converting into a pulse train signal an analog input voltage signal from a signal source, said A-D converter comprising a signal generator for providing a low analog input voltage signal of a low fixed level V L , a signal generator for providing a high analog input voltage signal of a high fixed level V H , a multiplexer connected to the signal source and the signal generators for receiving the signals therefrom and supplying the signals selectively and successively, a V-T converter connected to the multiplexer for converting a selected one of the analog input voltage signals into a pulse train signal; a memory for storing instruction programs used for A-D conversion, a central processing unit, a first counter connected to the V-T converter for counting pulses of the pulse train signal, said first counter being loaded with a specific value supplied from the central processing unit, a clock pulse generator for producing clock pulse, a second counter connected to the clock pulse generator for counting the clock pulses while the first counter is counting the same and a control circuit. | 7 |
BACKGROUND OF THE INVENTION
The present invention relates to a magnetic video signal recording and reproducing system (to be referred to as "VTR" in this specification) of the type wherein a plurality of rotating heads record the video signal on sequential discontinuous tracks on a magnetic tape and more particularly a magnetic recording and reproducing system which may record and reproduce the audio signal even when the tape transportation speed is considerably low.
In the prior art VTR, the video signal is recorded by a plurality of rotating magnetic heads on tracks inclined at an angle relative to the direction of transport of the magnetic tape and the audio signal is recorded by a stationary head on the edge of the magnetic tape.
The recording density of the video signal has been remarkably increased in VTR because of the improvements of the magnetic tapes, heads, techniques for processing the signal, accuracies and control techniques.
For instance, VHS VTR (capable of recording for four hours) has a recording density which is about 92 times as high as that of VTR units commonly used by broadcasting stations (of the type which uses a magnetic tape two inches in width and four heads) and about 11 times as high as that of EIAJ-I type VTR. VHS VTR uses a magnetic tape one half inch in width which is transported at the speed of 1.65 cm/sec. Extensive studies and experiments are continuing in order to further improve the characteristics of tapes and heads so that the recording density will be further increased in the future.
For instance, assume that the recording density will be doubled. Then the tape transport speed would become about 0.8 cm/sec when a magnetic tape with a half inch in width is used. At such a low transport speed, the magnetic recording and reproducing system with a stationary audio signal recording head cannot achieve high quality recording and reproduction because of the following reasons.
(a) At a low tape transport speed, the recording wavelengths become shorter so that the recording and reproduction of high frequencies becomes difficult and consequently a sufficient audio signal bandwidth (higher than 10 KHz) cannot be provided. (At a tape transport speed of 1 cm/sec, the highest frequency attainable at the present level of the audio-video techniques is 5 KHz.)
(b) At a low tape transport speed, the output from a reproducing head decreases, a low S/N results and hum occurs.
(c) At a low tape transport speed, the dynamic range of the level of the recorded signal becomes narrower and distortions tend to occur very frequently.
(d) Accuracies of a system for transporting a magnetic tape at a low speed in a stable manner are limited so that wow and flutter are enhanced.
Because of the reasons described above, even though the video signal may be recorded at a high density the audio signal cannot be recorded at a high density.
One of the methods for obtaining a relatively high tape transport speed even when the recording density of the video signal is increased is to reduce the width of a magnetic tape to for instance 1/4 or 1/8 inches. When the recording density is same, a magnetic tape with the width of 1/4 inches must be increased in length twice as long as a magnetic tape with the width of 1/2 inches. As a result, a tape cassette may be slightly reduced in thickness but increased in surface area. (Since the wall thickness of a case, the thickness of reel hubs and the spacing between the case and the reels remain unchanged, the thickness cannot be reduced to one half but to 2/3.) As a result, a cassette loading a magnetic tape with the width of 1/4 inches would become considerably large in size as compared with a cassette containing a magnetic tape with the width of 1/2 inches when both the tapes are assumed to be capable of recording for two hours. Furthermore the 1/4 inch tape cassette would be unbalanced. With a magnetic tape with the width of 1/8 inches, a relatively high tape transport speed may be attained, but its cassette would be extremely unbalanced. In addition to the problem of shapes of cassettes, the reduction in width of magnetic tapes gives rise to the problem of skew due to the expansion and compression of a magnetic tape (that is, the discontinuity in time of the signal when the heads are switched from one to another). Furthermore the angle of inclination of the video tracks relative to the direction of travel of a magnetic tape would become small so that the recording and reproduction is easily susceptible to adverse effects by waving of a magnetic tape and consequently the interchangeability of magnetic tape cannot be ensured. Moreover a satisfactory air film would not be produced between a head and a magnetic tape so that the transport of the magnetic tape becomes unstable, resulting in jitter. Thus it is apparent that the wider the magnetic tape, the better the recording and reproduction becomes.
As described above, because of the prior art audio signal recording and reproduction systems, the recording density cannot be increased and the cassette in desired shape and size cannot be provided.
One solution to the above problems is to frequency modulate the audio signal at frequencies exterior to and lower than the bandwidth of the frequency modulated video signal, multiplex with the video signal and then record the multiplexed signal on a magnetic tape as in the case of the video disk techniques. However with this frequency multiplex system, it is impossible to record the audio signal after the video signal has been recorded. This system may be applied to an apparatus used only for reproducing signals such as a video disk, but cannot be applied to an apparatus for recording and reproducing the audio and video signals such as a VTR.
SUMMARY OF THE INVENTION
Accordingly the main object of the present invention is to provide a magnetic recording and reproducing system which may attain the reliable and stable recording and reproduction of the audio signal even at a low tape transport speed by the time compression and expansion of the audio signal.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1(a) is a schematic side view of a prior art video tape recorder;
FIG. 1(b) is a top view thereof;
FIG. 2(a) is a schematic side view of a video tape recorder in accordance with the present invention;
FIG. 2(b) is a top view thereof;
FIGS. 3A-3B are block diagrams of a first embodiment of a magnetic recording and reproducing system in accordance with the present invention;
FIG. 4 is a block diagram of a time compression (expansion) circuit shown in FIG. 3;
FIG. 5, consisting of a-q, is a timing chart used for the explanation of the mode of operation of the first embodiment;
FIG. 6, consisting of a-f, is a timing chart used for the explanation of a further method for attaining the timing for writing the time compressed audio signal into a memory circuit in the playback mode;
FIGS. 7-10 show various audio and video signal recording patterns;
FIG. 11 shows a pattern for recording not only the video signal but also two channel audio signals;
FIGS. 12 A-12B are block diagrams of a magnetic recording and reproducing system of the present invention capable of recording not only the video signal but also two channel audio signals;
FIGS. 13a-j are timing charts used for the explanation of the mode of operation thereof;
FIG. 14 shows another recording pattern for recording the video signal and two channel audio signals;
FIG. 15 is a view used for the explanation of the wrapping of a magnetic tape around a rotating cylinder in order to attain the recording pattern shown in FIG. 14;
FIGS. 16-18 show various recording patterns for recording the video signal as well as two channel audio signals; and
FIG. 19 is a view used for explanation of the recording of two channel audio signals by frequency division techniques.
Same reference numerals are used to designate similar parts throughout the figures.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 is a view used for the explanation of the recording mode of a prior art two rotating head helical scanning type VTR. A magnetic tape 1 is wrapped about 180° (180°+2α) around a rotating head cylinder 2 with two rotating heads H A and H B so that the video signals are recorded in discontinuous oblique tracks 3. The audio signal is recorded by a stationary audio signal recording head 4 on a sound track along the upper edge of the magnetic tape 1. The control signal, which is used as the reference signal in the playback mode, is recorded by a control head 5 on a control track along the lower edge of the magnetic film 1.
In contrast to the prior art recording system described above, according to the present invention, the audio signal can be recorded by the rotating heads H A and H B without the use of a stationary audio signal recording head. The angle through which the magnetic tape 1 is wrapped around the rotating head cylinder 2 is increased by θ as compared with the prior art system. That is, the magnetic tape 1 is wrapped through an angle=180°+2α+θ around the rotating cylinder 2. The audio signal is compressed and recorded on the upper tracks 6 which are provided by increasing the wrapping angle by θ.
Next referring to FIGS. 3-5, a circuit for recording one channel audio signal in the manner described above will be explained. First referring to FIG. 3, the video signal to be recorded is applied to a terminal 7 and is frequency modulated by a frequency modulator 8. In response to the pulse from a gate pulse generator 15, the output signal from the frequency modulator 8 is gated by gate circuits 9 and 10. The gate pulse generator 15 is so designed and constructed as to generate various timing pulses in response to the output signal from a phase detector PG which detects the phase in rotation of the rotating heads H A and H B . More particularly, reference is made to FIG. 5. The phase detector PG generates the pulse (b) which leads the vertical synchronizing signal of the incoming video signal (a) by for instance seven horizontal synchronizing interval 7H. In response to the output from the phase detector PG, the gate pulse generator 15 generates gates pulses (c) and (d) which overlap each other for about 4H before and after the output pulse (b) from the phase detector PG. As a result, the output from the frequency modulator 8 is gated by the gate circuits 9 and 10 as shown at (f) and (g) and are applied to adders 11 and 12.
The audio signal is applied to a terminal 16 and is time compressed by a time compression circuit 17. The output from the time compression circuit 17 is applied to a frequency modulator 19. Sync signal separated by a sync separator 18 from the incoming video signal is also applied to the time compression circuit 17 which will be described in detail below. Thus time compressed and frequency modulated audio signal is transmitted to gate circuits 20 and 21 which gate it as shown at (j) and (k) in FIG. 5 in response to gate pulse (h) and (i). The gated signals are applied to the adders 11 and 12 which add the frequency modulated video signals (f) and (g) and the frequency modulated audio signals (j) and (k). The pulses (h) and (i) may be derived from monostable multivibrators which are triggered in response to the falling or trailing edges of the pulses (c) and (d).
The outputs from the adders 11 and 12 are transmitted to the rotating heads H A and H B through recording amplifiers 13 and 14 and record-playback switches SW1 and SW2, respectively, and are recorded in the tracks shown in FIG. 2.
In the playback mode, the signals reproduced by the rotating heads H A and H B are transmitted to preamplifiers 22 and 23 through the switches SW1 and SW2 whose movable contacts are now closing the stationary contacts P instead of R. The output from the preamplifier 22 and 23 are applied to gate circuits 24, 25, 29 and 30. In response to the pulse (e) from the gate pulse generator 15 which in turn is generated in response to the output (b) from the phase detector PG, the gate circuit 24 gates the reproduced frequency modulated video signal (f) for the interval Hi of the pulse (e). In response to the pulse opposite in polarity to the pulse (e), the gate circuit 25 gates the reproduced video signal for the time interval Hi. The outputs from the gate circuits 24 and 25 are added in an adder 26 so that the continuous video signal may be reproduced.
In response to the gate pulses (h) and (i) from the gate pulse generator 15, the gate circuits 29 and 30 gate the reproduced audio signals as shown at (j) and (k). The gated audio signals (j) and (k) are added in an adder 31 so that the continuous audio signal may be reproduced and applied to a demodulator 32.
The output from the adder 26 is applied to a demodulator 27 so that the reproduced video signal may be derived from its output terminal 28.
The output from the demodulator 32 is applied to a time expansion circuit 33 which expands the demodulated audio signal in response to the output from a sync separator 34 so that the reproduced audio signal may be derived from its output terminal 35. The time expansion circuit 33 will be described in detail below.
Referring particularly to FIG. 4, the time compression circuit 17 will be described in detail. The incoming audio signal is applied to the terminal 16 and then transmitted to two memory circuits 36 and 37.
The output from the sync separator 18 is applied to a terminal 18' and then applied to horizontal sync separator 38 and a vertical sync separator 39. The output from the horizontal sync separator 38 is applied to a write clock generator 40 and to a read clock generator 45. The write clock generator 40 generates the clock whose frequency f W is for instance two times as high as the frequency f H of the horizontal sync; that is, f W =31.5 KHz. In response to the clock signal (whose frequency f W =2f H =31.5 KHz), the audio signal whose frequency range is up to one half (15 KHz) of the clock frequency f W may be stored in the memories M-1 and M-2.
The output from the vertical sync separator 39 is applied to a flip-flop 41 from which is derived the output signal, or gate pulses Q and Q of 30 Hz (in the case of NTSC SYSTEM, but 25 Hz in case of the PAL system). In response to the gate pulses Q and Q gate circuits 43 and 44 gate write clocks to be applied to the memory circuits 36 and 37 so that the audio signal of the odd field may be stored in the memory circuit 36 while the audio signal of the even field may be stored in the memory circuit 37. The memory has 525 bytes. The portions A 1 and A 2 of the incoming audio signal shown at (1) in FIG. 5 are stored as A 1 and A 2 in the memory circuit 36 as shown at (n). The portions B 1 and B 2 of the incoming audio signal are stored as B 1 and B 2 in the memory circuit 37 as shown at (m) in FIG. 5. The audio signals thus stored in the memory circuits 36 and 37 are read out in response to the clocks from the read clock generator 45. It is assumed that the frequency f R of the read clock be 40 times as high as the horizontal sync frequency f H ; that is, f R =40 f H . Then
f.sub.R /f.sub.W =40f.sub.H /2f.sub.H =20
Therefore it follows that the audio signal stored during a time interval τ v =1/f v (where f v =vertical scanning frequency) may be read out during a time interval τ v /20. In other words, the audio signals A 1 , A 2 , . . . which are stored in the memory circuit 36 are time compressed to 1/20 and are read out as indicated A' 1 , A' 2 , . . . as shown at (n). In like manner, the audio signals B 1 , B 2 , . . . which have been stored in the memory circuit 37 are time compressed to 1/20 and are read out as B' 1 , B' 2 , . . . as shown at (m). The outputs from the memory circuits 36 and 37 are applied to an adder 48 from which the compressed audio signals may be derived as shown at (p).
The mode of generating the read clock pulse will be described. In response to the leading edge of the vertical sync separated by the vertical sync separator 39, a gate pulse generator 42 generates gate pulses which correspond to 525 read clock pulses. In response to the gate pulses, gate circuits 46 and 47 gate alternately the read clock pulses to be applied to the memory circuits 36 and 37 for a time interval equal to one field interval. The output from the flip-flop 41 is also applied to the gate pulse generator 42 so that the gating timing of the gate circuits 46 and 47 may be synchronized with that of the flip-flop 41.
It is the most reliable method to count the read clock pulses so that the pulse width of the gate pulse generated by the gate pulse generator 42 may exactly coincide with 525 read clock pulses, but in the recording mode it is not needed to make the pulse width of the gate pulse to coincide with 525 read clock pulses. The gate pulse may have a pulse width slightly longer than 525 read clock pulses.
The time compressed audio signal thus derived is transmitted from an output terminal 49 to the modulator 19 and gated by the gate circuits 20 and 21 in the manner described elsewhere in conjunction with FIG. 3. As shown at (h) and (i), the gating interval is longer than the compressed audio signal shown at (p) so that interference to the audio signal by the transient noise caused when the FM carrier is switched in the case of demodulation.
Next the expansion circuit 33 will be described. It is substantially similar in construction to the time compression circuit 17 described above except (1) that the write clock generator 40 is used as a write clock generator while the read clock generator 45 is used as a write clock generator and (2) that the flip-flop 41 is not triggered by the output from the vertical sync separator 39 but by the trailing edge of the write pulse (in the reproduction mode) from the gate pulse generator 42 as indicated by the broken lines. Furthermore it is required to reset the flip-flop 41 in order to select the polarity of the output pulse therefrom. The demodulated time compressed audio signals B' 0 , A' 1 , B' 1 , A' 2 , B' 2 , . . . shown at (p) in FIG. 5 are time expanded as B" 0 , A" 1 , B" 1 , A" 2 , B" 2 , . . . as shown at (q) and (r) so that derived from the output terminal of the time expansion circuit 33 is the continuous audio signal which lags behind the video signal by about one field (about 16 msec).
The time difference between the video signal and the audio signal is not noticed when it is in general less than 50 msec so that the time delay of 16 msec is quite negligible.
The memory circuits so far described are BBD, capacitor memories or analog memories such as CCD, but it is to be understood that digital memories may be also used when A/D and D/A converters are inserted between the input terminal 16 and the memory circuits 36 and 37 and between the memory circuits 36 and 37 and the adder 48. The mode of operation is substantially similar to that described above.
Next the frequency band of the compressed audio signal will be discussed. When the audio signal up to about 15 KHz is time compressed to 1/20 in the manner described above, it has the frequency band of 300 KHz which is considerably narrow as compared with the video signal band of 3 l MHz. Therefore in the case of frequency modulation, the carrier may be selected between hundreds KHz and a few MHz and the recording and reproduction with a satisfactory signal to noise ratio S/N may be ensured. This means that the audio signal may be further time compressed from 1/20 to 1/100 and that the frequency division may be used by modulating different carriers by two audio signals.
Referring back to FIG. 2, the additional angle θ is preferably slightly greater than 180°/20=9°. The increase in tape wrapping angle will not adversely affect the transportation of the magnetic tape 1.
So far in the recording mode the audio signal has been described as being time compressed and then frequency modulated, but it is to be understood that the time compressed audio signal may be phase or amplitude modulated.
Furthermore it is apparent that when the audio signal is converted into the digital signal and then time compressed, the time compressed digital signal may be recorded. (When the sampling frequency is 30 KHz and one sample is transmitted in ten bits, the clock frequency is 3 MHz even when the audio signal is time compressed to 1/10. The clock pulse frequency of 3 MHz is within the 4 MHz band of the video signal so that the time compressed, digital audio signal may be equally recorded by the rotating video signal recording heads.)
The time compressed audio signal is time expanded in the expansion circuit 33 in the playback mode. In this case, the compressed audio signal has been described as being stored in the memory circuits in response to the leading edge of the vertical sync signal which is reproduced, but it is also possible to correctly determine the timing for storing the compressed audio signal into the memory circuits without the use of the reproduced vertical sync signal as will be described below with reference to FIG. 6.
FIG. 6(a) shows the waveforms of the video signal adjacent to the vertical sync signal V. FIGS. 6(b) and (c) show the signals which are frequency modulated by the video signals shown at (1) in FIG. 5 and which overlap each other for a time interval of about 4H before and after the time point B at which the scanning of the video signal tracks is switched from one rotating reproducing head to another.
As shown at (d) in FIG. 6, the burst signal P which is generated in response to the clock signal, is inserted immediately before the time compressed audio signal A so that in the playback mode the compressed audio signal may be stored into the memory circuits a predetermined time (which may be zero) after the termination of the burst signal P. The burst signal P and the audio signal A are frequency modulated and gated for a time interval which is sufficiently longer than the length of the burst and audio signals P and A so that the frequency modulated signal as shown at (e) in FIG. 6 may be derived. The signal (e) is added to the video signal (b) so that the audio signal may be recorded on the track which is additionally provided by increasing the wrapping angle of the magnetic tape 1 by θ as described elsewhere.
Next the audio signal recording patterns which are different from that shown in FIG. 2 will be described. First referring to FIG. 7, in contrast to the recording pattern shown in FIG. 2 wherein the audio signal is recorded by both the two rotating heads H A and H B , the audio signal is recorded on the tape 1 only by one of the recording heads. To this end, the audio signal corresponding to two fields may be time compressed to 1/40. The frequency band of thus compressed audio signal becomes 600 KHz, which is still within the range at which the rotating magnetic heads may record and reproduce. Therefore the circuits described with reference to FIGS. 3 and 4 may be equally used. However the memory capacity must be doubled and two flip-flops 41 must be provided. The gate circuits 21 and 30 (See FIG. 3) may be eliminated. The recording pattern shown in FIG. 7 is advantageous in that even when the mistracking occurs, no audio signal is reproduced from the adjacent track so that cross talk may be eliminated.
Alternatively, the audio signal corresponding to four fields may be compressed and recorded on every four tracks, but the memory capacity must be increased accordingly. In like manner, the audio signal corresponding to three fields may be time compressed and recorded on every three tracks, but in case of the VTR with two rotating magnetic heads, two head must alternately record the audio signal so that the circuit becomes complicated. However with three rotating magnetic heads, one of them may record and reproduce so that the circuit will be simple in construction. In this sense, with four rotating magnetic heads, the method for recording the audio signal on every four tracks as described above may be advantageous.
When the tracking error occurs in the playback mode, cross talk may be eliminated in the following manner. That is, the frequency of the audio signal carrier to be recorded on one track is made different from the frequency of the audio signal carrier to be recorded on the next track so that the frequency band of the audio signal carrier to be recorded by one rotating magnetic head may not overlap the frequency band of the audio signal carrier to be recorded by the other rotating magnetic recording head. To this end, the modulator 19 shown in FIG. 3 may be so designed and constructed as to alternately switch two carrier frequencies and band-pass filters corresponding to the used carrier frequencies are inserted between the gate circuits 29 and 30 and the adder 31 (See FIG. 3).
A further method for eliminating cross talk is to use the azimuth recording which is employed in VHS VTR as shown in FIG. 9. That is, the gaps of the two rotating magnetic heads H A and H B are inclined at an angle in opposite directions. In the playback mode, the azimuth loss is therefore increased so that the cross talk between the adjacent tracks may be minimized.
So far the control signal has been described as being recorded on the track along the lower edge of the magnetic tape 1 while the audio signal has been described as being time compressed and recorded at the upper portions of the oblique tracks, but it is to be understood that the control signal may be recorded on the control track along the upper edge of the tape 1 while the audio signal is compressed and recorded at the lower portions of the oblique tracks as shown in FIG. 10. (In some systems no control track is required, however.) In this case, a circuit which is substantially similar to that shown in FIG. 3 may be used even though timing relationship must be changed, and the magnetic tape 1 is wrapped θ° more at the entering side of the rotating cylinder 2 (See FIG. 2).
So far the present invention has been described only in conjunction with the two head-helical scan type VTR, but it is to be understood that the present invention may be also equally applied to VTR systems with more than two rotating magnetic heads. Therefore the present invention may be also applied to devices of the type recording on recording media in the form of a card.
So far the video signal for one field has been described as being recorded on each oblique track, but it is also to be understood that the present invention may be equally applied to the systems in which the video signal for two fields or for 1/n fields (where n is an integer) are recorded on each oblique track.
So far the present invention has been described in conjunction with the recording of one channel audio signal, but the present invention may be also used to record two channel audio signals as will be described below.
First referring to FIG. 11, the audio signal in the channel 1 CH1 is time compressed and recorded by one rotating magnetic head H A in a manner substantially similar to that described above with reference to FIG. 7 while the audio signal in the channel 2 CH2 is compressed and recorded by the other rotating magnetic head H B at the upper edges of the oblique tracks HB. In case of tracking error, cross talk results, but when the gaps of the rotating magnetic heads are inclined at an angle in opposite directions as described elsewhere with reference to FIG. 9, cross talk between the adjacent tracks may be suppressed by azimuth losses.
Next referring further to FIGS. 12 and 13, a magnetic recording and reproducing system capable of recording and reproducing two channel audio signals together with the video signal will be described in detail. The system shown in block diagram in FIG. 12 is substantially similar in construction to that shown in FIG. 3 except that circuits with reference numerals 101-117 are added. That is, reference numeral 101 denotes a vertical sync separator; 102, a flip-flop; 103, a horizontal sync separator; 104 and 105, input terminals for receiving the incoming audio signals of the channels 1 and 2; 106 and 107, time compression circuits; 108, an adder; 109 and 110, gate circuits; 111 and 112, time expansion circuits; 113 and 114, output terminals from which the reproduced audio signals of channels 1 and 2 may be derived; 115, a vertical sync separator; 116, a flip-flop and 117, a horizontal sync separator.
The flip-flop 102 is triggered by the output from the vertical sync separator 101, and the polarities of its outputs are determined in response to the gate pulse from the gate pulse generator 15 which in turn is generated in response to the PG pulse shown at (b) in FIG. 13 from the phase detector which detects the phase in rotation of the rotating magnetic head H A . For instance, the flip-flop 102 generates the output signal Q as shown at (c) in FIG. 13. In response to the positive edge of the output signal Q, the incoming audio signal of the channel 1 CH1 applied to the input terminal 104 is stored into one of two memory circuits in the time compression circuit 106. That is, the audio signal A 1 for two fields (=32 msec) is stored as shown at (d). As soon as the audio signal A 1 has been stored, it is read out at a rate for instance 20 times as fast as the writing speed as A' 1 . Simultaneously the succeeding audio signal A 2 of the channel 1 CH1 is stored into the other memory circuit in the compression circuit 106 as indicated at (e) and is read out as A' 2 . In recording the audio signal of channel 1 CH1, the above steps are cycled.
In response to the negative edge of the output pulse Q shown at (c) in FIG. 13, the audio signal of the channel 2 CH2 corresponding to two-fields is stored as B 1 into one of two memory circuits in the time compression circuit 107 as indicated at (f) and is read out as B' 1 at a reading speed 20 times as fast as a writing time. The succeeding audio signal is stored as B 2 into the other memory circuit in the compression circuit 107 and is read out as B' 2 . In recording of the audio signal of the channel 2, the above steps are cycled.
As a consequence, derived from the adder 108 are the compressed audio signals A' 0 , B' 0 , A' 1 , B' 1 , . . . which alternates for every video signal for one field as indicated at (h) in FIG. 13. The compressed audio signals are transmitted through the modulator 19 and the gate circuits 20 and 21 to the adders 11 and 12 where they are added to the frequency modulated video signals. As a result the signal as shown at (i) is recorded by the head H A while the signal as shown at (j), by the head H B .
In the playback mode, the demodulated audio signal is gated by the gate circuits 109 and 110 into the compressed audio signals of the channels 1 and 2 CH1 and CH2 and applied to the time expansion circuits 111 and 112, respectively. The time expanded audio signals are derived from the terminals 113 and 114, respectively.
The flip-flop 116 generates the pulse signal in response to which the writing into the memory circuits in the expansion circuits 111 and 112 is timed. The polarities of its output signals are determined in response to the PG pulse (b) as in the case of the flip-flop 102. Both the horizontal sync separators 103 and 117 generate the reference signal in response to which the write and read clocks are generated as described elsewhere with reference to FIG. 4.
The time compression circuits 106 and 107 and the time expansion circuits 111 and 112 are substantially similar in construction to that shown in FIG. 4 so that no further description thereof shall be made in this specification.
Another embodiment of the system for recording and reproducing the audio signals of two channels is illustrated in FIGS. 14 and 15. As shown in FIG. 14, the audio signal of the first channel 1 CH1 are recorded at the upper edge portions of the oblique tracks while the audio signal of the second channel CH2, the lower edge portions of the oblique tracks. (If the magnetic tape 1 has a control track, the audio signal is recorded inwardly of the control track.)
The system for recording the two audio signals CH1 and CH2 as shown in FIG. 14 is substantially similar in construction to that described above with reference to FIG. 12, but the magnetic tape 1 must be wrapped further θ° both on the entering and leaving sides of the rotating cylinder as shown in FIG. 15. In order to correctly time the reproduction of the compressed audio signals, it is preferable to insert the burst signal P as described elsewhere with reference to FIG. 6.
A still further system for recording and reproducing two audio signals is shown in FIG. 16. The audio signal of the channel CH1 is recorded at every two upper edge portions of the oblique tracks while the audio signal of the channel CH2, at over two lower edge portions of the oblique tracks. As with the system described with reference to FIG. 7, no cross talk results even when tracking error occurs. Furthermore the control signal may be recorded on the blank tracks for the audio signal of the second channel CH2 so that the control track shown in FIG. 16 may be eliminated.
A yet further system for recording two audio signals is shown in FIG. 17. Both the time compressed audio signals of the channels CH1 and CH2 are recorded at the upper edge portions of the oblique tracks but are separated from each other by a guard. This system is apparent to those skilled in the art from the description of the systems with reference to FIGS. 3 and 13. In the record mode this system may time the compression of the audio signal of the channel CH2 with the completion of the time compression of the audio signal of the channel CH1. It is also preferable to insert the burst signal described with reference to FIG. 6.
As in the case of the system described elsewhere with reference to FIG. 7, both the compressed audio signals of the channels CH1 and CH2 are recorded on every two tracks and are staggered from each other as shown in FIG. 18.
A still further system for recording two audio signals is shown in FIG. 19. The compressed audio signal of the channel CH2 is subjected to the single sideband modulation (SSB) and recorded together with the compressed audio signal of the channel CH1 in frequency division manner in the recording pattern shown in FIG. 2, 7 or 10.
In FIG. 19 the signal f p is a pilot signal indicating that two audio signals are recorded and may be used as a carrier in case of the demodulation of the audio signal of the channel CH2. In this system the frequency multiplex signal as shown in FIG. 18 is modulated (preferably frequency modulated) and recorded. Instead of the single sideband modulation of the audio signal of the channel CH2, various modulations such as vestigal sideband modulation or vestigal sideband FM modulation may be used.
As described above, various systems may be used to compress two channel audio signals and record them on the magnetic tape contiguous with the video signal. It if is desired to erase the audio signal of one channel and record new audio signal, a stationary erase head may be used to erase the audio signal of one channel when the audio signals are recorded in the pattern as shown in FIG. 14 or 16 and then new audio signal may be recorded on erased tracks. Alternatively, new audio signal may be superposed on the previossly recorded audio signal when the recording pattern as shown in FIG. 11 or 17 is used.
In summary, according to the present invention even when the recording density is further increased so that the tape transportation speed is lowered, two channel audio signals may be positively recorded. The advantages of the present invention may be summarized as follows:
(1) The audio band of 15 KHz may be secured independently of the tape transportation speed.
(2) Adverse effects due to wow and flutter may be substantially eliminated because variations in rotational speeds in VTR is extremely small. Let v t denote the tape transportation speed and v H , the peripheral speed of the rotating head. Then wow and flutter is given by v t /v H , which is in general less than 1/100. As a result, wow and flutter can be suppressed negligible when the rotating heads are used for the recording of the audio signal.
(3) Stationary audio signal recording and reproduction heads may be eliminated because the rotating video signal recording and reproduction heads may be used in recording the audio signal.
(4) Both the video and audio signals are recorded by common rotating magnetic heads, but it is also possible to record the audio signal after the video signal has been recorded. More particularly, the audio signal on the oblique audio tracks may be erased by a stationary erase head and new audio signal may be recorded. Furthermore it is possible to record new audio signal over the previously recorded audio signal because the previously recorded audio signal is erased and only the newly recorded audio signal remains. The reason is that the audio signal is modulated with high frequencies and recorded at short waves. | In a magnetic recording and reproducing system of the type wherein a plurality of rotating magnetic heads record the video signal on a magnetic tape as tracks which are inclined at an angle relative to the direction of travel of the magnetic tape, the audio signal is time compressed and recorded by the rotating magnetic heads on tracks contiguous with either or both ends of said video signal recording tracks, whereby even at a considerably low tape transport speed the audio signal may be recorded in a stable manner. | 7 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to the field of ammunition, more specifically, to non-lethal ammunition used in training and war games that could also be used in automatic and semi-automatic firearms.
[0003] 2. Description of the Related Art
[0004] There has long existed the need for firing practice of automatic and semi-automatic firearms. As automatic firearms are used by more and more organizations such as the military and police, the need for an effective practice has grown urgently. The idea practice round for automatic and semi-automatic weapons incorporates the functions of firing a non-lethal projectile to mark the impact point, satisfactorily actuating the automatic ejection of the spent casing, functioning in a standard firearm with a minimum modification, and being relatively inexpensive.
[0005] The primary problem that has existed in using automatic or semi-automatic firearms is the providing of enough “kickback” without raising the muzzle velocity or impact force of the projectile. Usually with practice or non-lethal rounds it is important to maintain lower muzzle velocities and keep weight, and therefore to reduce the inertia of the projectile, at a minimum. However, under such circumstances, usually such rounds have not provided enough back force for automatic ejection mechanism for proper actuation.
[0006] Practice firearms nowadays being used involve those utilizing a laser, CO 2 actuation or blanks. Obviously, the laser type devices are expensive, somewhat cumbersome, and usually are not conventional in operation. CO 2 type practice devices are sometimes actuating a capsule type of cartridge with high-pressurized gas and are usually not conventional in operation. The firing of blanks obviously involves no projectile to mark the point of impact and thus unable to offer the advantage of the conventional firearms during practice.
[0007] However, during the ballistic cycle of ammunition, the operation of conventional automatic and semi-automatic firearms are actuated either by the expansion of propellant gas against a sabot connected to the recoiling bolt or by direct blowback of the cartridge case against the bolt upon expansion of the propellant gas. In these systems, the energy provided to the recoil mechanism is related to that imparted to the projectile. That is, a reduced pressure in the chamber or variations in weight of the projectile will result in variation of the total energy given to the firearm-operating mechanism which, in turn, will affect its cyclic rate or the reliability of its operation. With low-mass projectiles or the type used in training and non-lethal cartridge, the problem is especially severe. Frangible projectiles may not be capable of withstanding high accelerations. The low energy required for launch of these lightweight projectiles may not produce a sufficient reaction or necessitate a high enough chamber pressure to cycle conventional firearm mechanisms. Blank cartridge, that is, a cartridge without a projectile, will not normally be able to automatically cycle ejection without a muzzle adapter to increase the pressure in the system sufficiently to make the mechanism function.
[0008] The above mentioned problem may also be observed in larger caliber guns, such as 40 mm grenade launchers, where a relatively low-velocity projectile with limited capacity to withstand high accelerations, is launched from an automatic gas-operated firearms. To overcome such problems, the “high-low” ballistic system is adopted. Propellant in the “high-low” ballistic system is initially burned in a high-pressure section of a partitioned cartridge case and released through orifices into the side containing the projectile at a rate sufficient to limit the peak pressure or acceleration on the projectile. Such a system is described in U.S. Pat. No. 4,686,905. While such system can provide reduced peak forces available for firearm function, necessitating design compromises in the firearm.
[0009] U.S. Pat. No. 5,359,937 entitled “Reduced Energy Cartridge”, issued to Dittrich on Nov. 1, 1994, disclosed a cartridge for low-mass, frangible projectile which comprises a sabot to propel against an inner shoulder of a chamber. The cartridge has a sabot with an orifice applied to lead the propellant gas from the rear of a sabot to the rear of a projectile in order to eject the projectile under controlled impact force. The wall of the cartridge case has an inwardly extended flange and the bottom of the sabot has an outward step. Upon percussion, the cartridge case is pushed backward opposite the sabot by expansion of propellant gas and the step of the sabot is engaged with the flange of the case to engage the cartridge case together with the sabot, thus enables the spent sabot and the cartridge case to eject together. However, during assembly, because the outer diameter of the step of the sabot is larger than the inner diameter of the flange of the case, the sabot is unable to be inserted into the case directly. Other than extra finishing process, material with good malleability, such as copper is necessary for the cartridge case in order to insert the sabot smoothly into the case during assembling.
SUMMARY OF THE INVENTION
[0010] It is the primary object of the present invention to provide a practice cartridge which can launch a low-mass, frangible, non-lethal or low energy projectile and the cartridge can be produced efficiently and the material is not limited to conventional copper material, hence to reduce the production cost.
[0011] It is still another object of the present invention to provide a practice cartridge which can launch a low-mass, frangible, non-lethal or low energy projectile and the cartridge can be used in existing semi-automatic and automatic firearms to maintain their reliability of cycling mechanism in semi-automatic and automatic firearms.
[0012] The above-mentioned objects of the invention are achieved by the provision of a cartridge used in existing firearms, such as semi-automatic and automatic firearms, to launch a low-energy projectile. The cartridge comprises a cartridge case having a rear-end portion and a front-end portion, the front-end portion defining an inner diameter and its inner side-wall having an inclined groove; a primer disposed in the bottom of the cartridge case; a sabot comprising a front-end portion with a greater diameter and a rear-end portion with a smaller diameter, the rear-end portion having a substantially occlude end, wherein the outer diameter of the rear-end portion is substantially the same as the inner diameter of the inner wall of the cartridge case fitted hermetically into the cartridge case forming a hermetic space therein, and the outside of the rear-end portion is provided with a groove. The front-end portion of the sabot may be propelled against the shoulder of the chamber and the rear-end portion has at least an orifice to connect the hermetic space to the front-end portion allowing the propellant gas within the hermetic space bleed to the front-end portion through the orifice. Also a limiting element is disposed in the groove of the sabot. Upon percussion, as the inclined groove of the cartridge case slides towards the limiting element, due to the elasticity, the limiting element returns to its uncompressed state and engages with the inclined groove of the cartridge case, thereby limiting the further movement of the cartridge case relative to the sabot.
[0013] According to the cartridge of the present invention, during assembly, the limiting element disposed in the groove of the sabot is fitted into the cartridge case. As the limiting element passes through the inclined groove in the cartridge case, it extends into the inclined groove due to the elasticity. However, as the inclined groove has an inwardly inclined surface, the limiting element can be compressed into the groove by the inclined surface. Thus the sabot can further enter into the cartridge case until the step of the sabot is propelled against the cartridge case. Therefore, the cartridge of the invention can overcome the limitation on manufacture and materials described on U.S. Pat. No. 5,359,937.
[0014] Upon percussion, the propellant gas bursts from the hermetic space through the orifice to the rear-end portion of the projectile to eject the projectile. The front-end portion of the sabot is propelled against the shoulder of the chamber, therefore the cartridge case is pushed backward by the expanded gas generated from the powder. As the inclined groove of the cartridge case slides toward the limiting element, due to the elasticity, the limiting element returns to its uncompressed state and engages with the inclined groove of the cartridge case. Thereby it limits the further movement of the cartridge case relative to the sabot to ensure the spent sabot and the cartridge case to be ejected together in order to achieve the aim of cycling the automatic and semi-automatic firearms.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Other objects, advantages, and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.
[0016] [0016]FIG. 1 is a perspective view of a cartridge in accordance with a first embodiment of the invention;
[0017] [0017]FIG. 2 is an exploded view of a cartridge in accordance with a first embodiment of the invention;
[0018] [0018]FIG. 3 is a cross sectional view of a cartridge in accordance with a first embodiment of the invention;
[0019] [0019]FIG. 4 is a cross sectional view of a cartridge after percussion in accordance with a first embodiment of the invention;
[0020] [0020]FIG. 5 is a cross sectional view of a cartridge in accordance with a second embodiment of the invention;
[0021] [0021]FIG. 6 is a cross sectional view of a cartridge after percussion in accordance with a second embodiment of the invention;
[0022] [0022]FIG. 7 is a cross sectional view of a cartridge in accordance with a third embodiment of the invention; and
[0023] [0023]FIG. 8 is a cross sectional view of a cartridge after percussion in accordance with a third embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0024] A first embodiment of a cartridge 10 in accordance with the present invention is depicted generally in FIGS. 1 and 2. The cartridge 10 can be used in conventional firearms, such as semi-automatic and automatic firearms. The cartridge 10 mainly comprises a cartridge case 21 , a sabot 11 disposed in the cartridge case 21 , and a projectile 30 fitted tightly within the front-end portion of the sabot 11 . A limiting element 31 , which is preferable a C-type ring, is disposed between the cartridge case 21 and the sabot 11 of the cartridge 10 .
[0025] [0025]FIG. 3 illustrates the cross sectional view of the cartridge 10 . The cartridge case 21 is a substantially hollow cylindrical body having a primer 26 disposed at the bottom of the cartridge case 21 which provides ignition and/or propulsion energy. A flange 24 at the end of the cartridge case 21 is used to engage with a recoil mechanism to eject the cartridge 10 after percussion. An annular inclined groove 22 is formed at the inner wall of the front-end portion of the cartridge case 21 .
[0026] The sabot 11 of the cartridge 10 has a front-end portion 13 with a larger diameter and a rear-end portion 15 with a smaller diameter, between which a step 18 is formed. The bottom of the rear-end portion 15 with a smaller diameter is substantially closed; its outer diameter is substantially the same as the inner diameter of the cartridge 21 to be fitted tightly into the hollow cylindrical inner wall of the cartridge 21 . A groove 12 is formed on the outer wall of the rear-end portion 15 of the sabot 11 . After the sabot 11 is inserted to the cartridge case 21 , a hermetic space 33 for loading powder 34 is formed between the rear-end portion 15 of the sabot 11 and the bottom of the cartridge case 21 . The outer diameter of the front-end portion 13 is substantially the same as the outer diameter of cartridge case 21 . The front-end portion 13 comprises a recess 14 for receiving a projectile 30 . The rear-end portion 15 of the sabot 11 has at least an orifice 16 to connect the hermetic space 33 to the rear of the projectile 30 allowing the propellant gas within the hermetic space 33 bleed to the projectile 30 through the orifice 16 .
[0027] As the cartridge 10 of the present invention is assembled, the limiting element 31 , preferably a C-type ring, is disposed in the groove 12 of the sabot 11 and corporately fitted into the cartridge case 21 . As the limiting element 31 passes through the inclined groove 22 of the cartridge case 21 , it expands outwards and slides into the inclined groove 22 due to the elasticity. However, as the inclined groove 22 has an inwardly inclined surface, the limiting element 31 can be compressed into the groove 12 by the inclined surface. Thus, the sabot 11 can further enter into the cartridge case 21 until the step 18 of the sabot 11 is propelled against the cartridge case 21 .
[0028] The cartridge 10 may be stored for a long duration after manufacture. The inner wall of the cartridge case 21 preferably has a slot 28 corresponding to the limiting element 31 . When the sabot 11 is tightly fitted in the cartridge case 21 , the limiting element 31 may expand slightly to fit into the slot 28 to preserve its elasticity. After long-term storage, the limiting element 31 of the cartridge 10 will not lose its elasticity caused by long-term elastic fatigue so as not to limit the further travel of sabot 11 opposite to the cartridge case 21 after percussion (described thereinafter).
[0029] In FIG. 4, when the cartridge 10 is being operated, i.e., upon the primer 26 being ignited to induce the expansion of the powder 34 , the propellant gas outbursts from the hermetic space 33 through the orifices 16 to the rear-end portion of the projectile 30 , thereby ejecting the projectile 30 (as the arrows point in FIG. 4). The desired energy for ejecting the projectile 30 may be obtained by adjusting the amount and the size of the orifice(s) 16 . The front-end portion 13 of the sabot 11 is propelled against the shoulder (not shown in the drawings) inside the chamber, therefore the cartridge case 21 is moved backward by the expanded gas produced from powder 34 . As the inclined groove 22 of the sabot 21 slides to the limiting element 31 , the compressed limiting element 31 returns to its uncompressed state due to the elasticity and is engaged with the inclined groove 22 of the cartridge case 21 , thereby limiting the further movement of the cartridge 21 relative to the sabot 11 . The front-end of the sabot 11 is propelled against the shoulder of the chamber of automatic or semi-automatic firearms (not shown in drawings) and by the backward movement of the cartridge case 21 , the flange 24 of the cartridge case 21 is engaged with a recoil mechanism. Thus it enables the sabot 11 of the cartridge 10 and the cartridge case 21 to be ejected together to cycle the automatic and semi-automatic firearms.
[0030] As mentioned above, the projectile 30 of the cartridge 10 of the present invention does not effect the cycle of automatic and semi-automatic firearms. Therefore the projectile 30 can be made of multiple materials and made in multiple forms. For example, the projectile 30 may be a hollow plastic capsule with a pre-cracked notch 44 on top surface, which is filled with a marking dye, a tear gas substance or the like. As the projectile 30 hits a target, the projectile 30 may be broken easily from the pre-cracked-notch 44 and release the filled substance to achieve the functions such as marking the impact point. Further, when the cartridge 10 is blank, i.e., the cartridge 10 has no projectile 30 , the propellant gas escapes from a muzzle, producing the flash and noise and reinforcing the effect of the blank. However, it does not influence the cycle of automatic and semi-automatic firearms.
[0031] The cartridge 40 of the second embodiment of the invention is shown in FIG. 5 and FIG. 6. The mechanism of the cartridge 40 is substantially similar to that of the cartridge 10 , wherein like reference numerals refer to like elements. The difference between the cartridge 10 and the cartridge 40 is the construction of the limiting element 41 of the present embodiment.
[0032] According to the cartridge 40 of the present embodiment, the sabot 11 has at least two recesses 12 at the outside of the rear-end portion 15 . A limiting element 41 includes a pin 42 and a compressed spring 43 . The pin 42 and the compressed spring 43 are disposed respectively into the recess of the sabot 11 . When the cartridge of the present invention is assembled, as the pin 42 and compressed spring 43 pass through the inclined groove 22 of the cartridge case 21 , the pin 42 extends into the inclined groove 22 forced by the compressed spring 43 . However, as the inclined groove has an inwardly inclined surface, the pin 42 can be compressed into the groove 12 by the inclined surface. Thus the sabot 11 can further enter into the cartridge case 21 till the sabot 11 is propelled against the cartridge case 21 . The inner wall of the cartridge 21 , preferably, further comprises a slot 28 corresponding to the pin 42 . When the sabot 11 is tightly fitted in the cartridge case 21 , the pin 42 may expand slightly into the slot 28 to preserve the elasticity of the spring 43 .
[0033] In FIG. 6, when the cartridge 40 is being operated, i.e., upon the primer 26 being ignited to induced the expansion of the powder 34 , the propellant gas outbursts from the hermetic space 33 through the orifice 16 to the rear portion of the projectile 30 to eject the projectile 30 (as the arrows point in FIG. 6). The front-end portion 13 of the sabot 11 is propelled against the shoulder (not shown in drawings); therefore, the cartridge case 21 is pushed backward by the expanded gas produced from the powder 34 . As the inclined groove 22 of the sabot 11 slides to the pin 42 , the compressed spring 43 returns to its uncompressed state due to the elasticity and is engaged with the inclined groove 22 of the cartridge case. Therefore, it limits the movement of the cartridge case 21 relative to the sabot 11 . The sabot 11 is propelled against the shoulder inside the chamber of automatic or semi-automatic firearms (not shown in drawings); the flange 24 of the cartridge case 21 is engaged with a recoil mechanism by the backward movement of the cartridge case 21 . Thus it enables to eject the spent sabot 11 of the cartridge and cartridge case 21 together and to cycle the automatic and semi-automatic firearms.
[0034] The cartridge 50 of the third embodiment of the invention is shown in FIGS. 7 and 8. The mechanism of the cartridge 50 is substantially similar to that of the cartridge 10 , wherein like reference numerals refer to like elements.
[0035] The difference between the cartridge 10 and the cartridge 50 is that the inclined groove 72 is disposed at the end of the sabot 61 and the cartridge case 71 comprises a corresponding groove 62 . Similar to the operation of the cartridge 10 of the above-mentioned embodiments, the limiting element 81 is disposed, during manufacture, into the inclined groove 72 of the sabot 61 and compressed, then fitted corporately into the cartridge case 71 , and then expands into the groove 62 . Thus the limiting element 81 is disposed into the groove 62 and compressed by the inclined surface of the inclined groove 72 . Therefore, the sabot 61 further is fitted into the cartridge case 71 . Alternatively, the sabot 61 also may have another slot 78 to contract the limiting element to preserve the elasticity of the limiting element 81 and to limit the movement of the cartridge case 71 relative to the sabot 61 after percussion.
[0036] In FIG. 8, when the cartridge 50 is in operation, i.e., upon the primer 76 ignited to induce the expansion of the powder, the propellant gas outbursts from the hermetic space 83 through the orifice 66 to the rear of the projectile 80 to eject the projectile 80 (as the arrows point in FIG. 8). Further, the cartridge case 71 also is pushed backward by the expanded gas produced from the powder. As the cartridge case 71 and the limiting element 81 slide backward through the inclined groove 72 of the sabot 61 , the limiting element 81 returns to its non-contracted state due to the elasticity and is engaged with the inclined groove 72 of the sabot 61 . Therefore, it limits the further movement of the cartridge case 71 relative to sabot 61 . The sabot 61 is propelled against the shoulder of chamber of automatic or semi-automatic firearms (not shown in drawings); the flange 74 of the cartridge case 71 is engaged with a recoil mechanism by the backward movement of the cartridge case 71 . Thus it enables to eject the spent cartridge 50 to cycle the automatic and semi-automatic firearms. Similarly, in accordance with this embodiment of the present invention, the cartridge 50 also may be in blank form or its projectile 80 may be a hollow plastic capsule with a pre-cracked-notch 84 on top surface, which is filled with a marking dye or the like to achieve the functions such as marking the impact point.
[0037] According to the above illustration, the cartridge case in accordance with the present invention does not need complicate processes for malleablization and deformation, it can be made of materials with less malleability, such as aluminum, iron, plastic material, or composite materials.
[0038] Therefore, the cartridge of the present invention may not only maintain the reliability of firearm-cycling mechanism of automatic and semi-automatic, the cartridge can also be made easily, thus this invention overcomes the limitation on manufacturing and material which is disclosed in U.S. Pat. No. 5,359,937.
[0039] Although the invention has been explained in relation to its preferred embodiment, it is to be understood that many other possible modifications and variations can be made without departing from the spirit and scope of the invention as hereinafter claimed. | This invention provides a cartridge assembly for military and police training to meet the requirement of practicing vividly while making no harm. The assembly mainly comprises a projectile, a sabot, a C-type ring, and a cartridge case, wherein the projectile is disposed in the recess of the sabot; the sabot is fitted tightly into the case and the C-type ring is disposed in the slot at the bottom of the sabot. Upon a primer being struck to ignite powder, the expanding gas partially outbursts and bleed through an orifice to propel a projectile and the other part of energy is applied to eject the cartridge case. As the cartridge case being pulled back, the elasticity of the C-type ring results into the engagement of the sabot and the cartridge case, so as to achieve the aim of the ballistic cycle of the ammunition. | 5 |
FIELD OF THE INVENTION
[0001] The present invention concerns a method and a system for determining the location of an object as a receiver or a transmitter.
DESCRIPTION OF RELATED ART
[0002] Indoor localization systems have become a popular research area in the last years, and many universities and companies do research in this field.
[0003] There are numerous applications of indoor localization, covering a broad range of fields. One example is inventory management: keeping track of the location and the amount of a particular good in a warehouse. Another application is object tracking, such as localizing medical personnel or equipment in a hospital or tracking people with limited mobility to understand if they need assistance. Yet another application that drew considerable attention is location aware services. When you visit a museum, you are given a device, and if you want to get information about a specific piece of artwork, you can enter a code related to that artwork to retrieve it. However, if the device was aware of the location of the person, it could detect which artwork the person is approaching and information about it can be directly retrieved without the need of the user entering any information. Another important fields where indoor localization are security and rescue operations, such as detecting the location of police dogs trained to find explosives, or localizing firemen in a building on fire.
[0004] Positioning systems, containing both indoor and outdoor localization, can be divided into three main topologies. The first one is self-positioning system, where the receiver receives data from distributed transmitters in order determine its own position (e.g. GPS). Second topology is remote positioning, where receivers located at possibly multiple locations measure the signal coming from the object in order to localize it. Third topology that has two subcategories is called indirect positioning: A data link is used to transfer position information from the self-positioning system to a remote site or vice-versa.
[0005] Besides different topologies of indoor localization, there are also different modalities. One of the modalities is GPS. Although GPS is one of the most accurate outdoor localization systems, since the signals coming from the satellites have poor indoor penetration due to shielding by the concrete, the performance is poor indoors. Another modality is the radio-frequency identification (RFID). This method has found applications in tracking objects in warehouses or assembly lines. There are two different RFID setups: passive and active RFID tags. Passive RFID tags are inexpensive to manufacture, but the reading ranges are short, typically 1-2 meters, and the tag readers are expensive to manufacture. Active tags are more expensive to produce, but they have increased range and the tag readers are less expensive. Another modality is using the cellular network. This enables indoor localization when the building is covered by multiple base stations. However, the accuracy depends dramatically on how well the location is covered and on the building's structure. Wireless local area network (WEAN) is also used for indoor localization. However, this approach needs preinstalled infrastructure and the performance fluctuates since the channel changes over time. Another approach is by using ultra-wideband (UWE) radio, which is one of the most promising technologies for indoor localization. First, UWB can send sharp pulses that enable precise localization of time of arrivals in the receivers. Second, UWB can penetrate walls, equipment and clothing, thus the signal can be observed even behind obstructions. Finally, one can use sound and ultrasound. The equipment needed for ultrasound localization is inexpensive and easily accessible. Furthermore, there are planar ultrasound transceivers, that is, transmitters and receivers that emit and receive in the 2D plane. This reduced the total amount of reflections we deal with and simplifies the design.
[0006] Although indoor localization has been studied for twenty years, the field is still an active research area and open for further developments.
[0007] It is an aim of the present invention to obviate or mitigate one or more of the disadvantages of the prior art.
[0008] It is another aim of the present invention to find an alternative to the solutions of the prior art.
BRIEF SUMMARY OF THE INVENTION
[0009] According to the invention, these aims are achieved by means of a method for determining the location of a transmitter in a space defined by one or more reflective surfaces, comprising the steps of
[0010] sending a signal from this transmitter;
[0011] receiving by a set of receivers the transmitted signal and echoes of the transmitted signal reflected by these reflective surfaces;
[0012] finding by a first computing module the location of the virtual sources of the echoes;
[0013] mirroring by a second computing module the virtual sources into the space and obtained mirrored virtual sources;
[0014] combining by a third computing module the locations of the mirrored virtual sources so as to obtain the location of the transmitter.
[0015] Advantageously the location of the set of receivers and the location and/or orientation of the reflective surfaces are known.
[0016] The method according to the invention locates a source or transmitter in a room with general geometry bounded by reflective surfaces using the measurements by the set of receivers, e.g. a microphone array. In other words, the geometry of the space defined by the reflective surfaces (e.g. a room) does not have to convex, and a direct path between the transmitter and the receiver(s) is not necessary. The method assumes the knowledge of the room geometry and microphone positions.
[0017] The proposed method corresponds to a system architecture fitting in remote localization topology. The method utilizes the direct signal (if present) and early reflections to localize the source. In this context the expression “direct signal” indicates the signal sent by transmitter and directly, i.e. without reflections, received by a receiver or the set of receivers.
[0018] The method according to the invention advantageously makes use of early reflections or echoes, enabling to localize the source even when there is no line of sight. The method uses method of images to reduce the problem of indoor source localization to multiple source localization in free field, and then finding the source position. In other words, the method of images is used to reduce the problem of localizing the source in indoor environment to multiple source localization in free space and then estimating the source position.
[0019] In order to localize the multiple virtual sources, combinatorially selected echoes from each receiver of the set of receivers are used and the resulting location is tested to check if the echoes were corresponding to a single virtual source, for example, the resulting location is tested to check if the echoes uniquely localize a single virtual source.
[0020] After locating the virtual sources, the method according to the invention finds the position or location inside the room that results in the generation of such virtual source.
[0021] The step of mirroring of the method comprises applying the method of images in reverse order (“inverse method of images”, or “inverse image source model”). This mirroring procedure could have additional applications, whenever it is possible to observe anything through echoes, and the geometry of the reflective surfaces is known. A possible application is e.g. GPS in urban environments, where the method according to the invention allows to “see” the satellite only through (possibly multiple) reflections.
[0022] The method according to the invention localizes an arbitrary number of image sources and reflects them iteratively until they are in the room. The main idea is then to use the knowledge of the locations of the virtual sources for finding the (unknown) location of the real and original source. Advantageously the inverse method of images reflects the locations of the virtual sources back to the real source location.
[0023] The virtual source could be of arbitrary order (1st, 2nd, 3rd, . . . ).
[0024] Advantageously the step of mirroring comprises:
[0025] drawing the lines connecting a virtual source to the set of receivers,
[0026] finding the reflective surface which intersects these lines,
[0027] reflecting the virtual source across this reflective surface and generating a reflected virtual source,
[0028] storing the points of intersections on the reflective surface,
[0029] checking if the reflected virtual source is inside the space defined by the reflective surfaces,
[0030] repeating the previous steps if the reflected virtual source is not inside the space defined by the reflective surfaces.
[0031] In other words, if the reflected virtual source is not inside the space defined by the reflective surfaces, the following steps are performed:
[0032] drawings the lines connecting the stored points of intersections and the reflected virtual source,
[0033] finding the new reflective surface which intersects these lines,
[0034] reflecting the reflected virtual source across this reflective surface and generating a new reflected virtual source,
[0035] storing the points of intersections on the new reflective surface,
[0036] checking if the new reflected virtual source is inside the space defined by the reflective surfaces,
[0037] repeating the previous steps if the new reflected virtual source is not inside the space defined by the reflective surfaces.
[0038] In one embodiment, the method according to the invention comprises echoes' sorting, i.e. grouping the echoes corresponding to a single virtual source.
[0039] In one embodiment grouping the echoes corresponding to a single virtual source comprising checking if
[0000]
∑
i
=
1
M
(
s
.
-
m
i
-
r
i
)
2
[0000] is less than a threshold, wherein M is the number of receivers, ŝ is the estimated location of the virtual source with the current selection of echoes, m i is a receiver and r i the distance between the transmitter and the m i receiver.
[0040] Advantageously the method according to the invention comprises optimization of the source location. A measure based on the simulated room impulse response from the estimated source location is defined to find the best estimate for the true source position within the reflected virtual sources.
[0041] After choosing the estimate from the set of reflected virtual sources, its position is optimized based on the difference between simulated and recorded impulse responses.
[0042] In one embodiment the optimization of the source location estimate comprises a gradient descent method, which is used for optimizing the estimated location based on the simulated room impulse response.
[0043] The method according to the invention could comprise the tracking of the transmitter by using an optimization method. The optimization algorithm can then be applied to the problem of source tracking, where the new position of the source is estimated by applying optimization based on the position estimated in the previous time instance. In other words, the optimization method is applied for tracking a moving source based on previous position estimates.
[0044] By duality, in one particular embodiment, the method can be applied to localizing a microphone using multiple transmitters. In another particular embodiment, the method of the invention can be applied to GPS, wherein the transmitter is a mobile device, and the receivers are satellites (which, although is opposite to the standard whereby mobile device are receivers and satellites are the transmitters, is conceptually the same). It will be understood that the method of the invention can equally be applied to GPS, wherein the transmitter is a satellite, and the receiver is a mobile device. The application of the method of the invention to GPS will be described in more detail later.
[0045] The present invention concerns also a system for determining the location of a transmitter, comprising:
[0046] one or more reflective surfaces
[0047] one transmitter for sending a signal;
[0048] a set of receivers for receiving the transmitted signal and echoes of the transmitted signal reflected by these reflective surfaces;
[0049] a first computing module for finding the location of the virtual sources of said echoes;
[0050] a second computing module for mirroring the virtual sources into the room and obtained mirrored virtual sources;
[0051] a third computing module for combining the locations of these mirrored virtual sources so as to find the location of the transmitter.
[0052] In one preferred embodiment, the first computing module, the second computing module and the third computing module are the same module.
[0053] In one preferred embodiment, the signal is a UWB signal, the transmitter being a UWB transmitter and the receivers being UWB receivers. However other kinds of signals (e.g. acoustic, RF, light, etc.) can be used, as will be discussed.
[0054] The present invention concerns also a computer program product, comprising:
[0000] a tangible computer usable medium including computer usable program code for determining the location of a transmitter sending a signal received by a set of receivers, the set of receivers receiving also echoes of the transmitted signal reflected by one or more reflective surfaces, the computer usable program code being used for
[0055] finding by a first computing module the location of the virtual sources of these echoes;
[0056] mirroring by a second computing module the virtual sources into the space and obtained mirrored virtual sources;
[0057] combining by a third computing module the locations of these mirrored virtual sources so as to obtain the location of the transmitter.
[0058] By duality, the same procedure can be performed to localize a receiver with several transmitters in a non-convex room.
[0059] The present invention concerns then also a method for determining the location of a receiver in a space defined by one or more reflective surfaces, comprising the steps of
[0060] sending a signal from a set of transmitters;
[0061] receiving by this receiver the transmitted signal and echoes of the transmitted signal reflected by these reflective surfaces;
[0062] finding by a first computing module the location of the virtual receivers of the echoes;
[0063] mirroring by a second computing module the virtual receivers into the space and obtained mirrored virtual receivers;
[0064] combining by a third computing module the locations of the mirrored virtual receivers so as to obtain the location of the receiver.
[0065] The present invention concerns then also a system for determining the location of a receiver, comprising:
[0066] one or more reflective surfaces
[0067] a set of transmitters for sending a signal;
[0068] this receiver for receiving the transmitted signal and echoes of the transmitted signal reflected by said reflective surfaces;
[0069] a first computing module for finding the location of the virtual receivers of the echoes;
[0070] a second computing module for mirroring the virtual receivers into the room and obtained mirrored virtual receivers;
[0071] a third computing module for combining the locations of the mirrored virtual receivers so as to find the location of the receiver.
[0072] The present invention concerns then also a computer program product, comprising:
[0000] a tangible computer usable medium including computer usable program code for determining the location of a receiver receiving a signal transmitted by a set of transmitters, the receiver receiving also echoes of the transmitted signal reflected by one or more reflective surfaces, the computer usable program code being used for
[0073] finding by a first computing module the location of the virtual receivers of the echoes;
[0074] mirroring by a second computing module the virtual receivers into the space and obtained mirrored virtual receivers;
[0075] combining by a third computing module the locations of the mirrored virtual receivers so as to obtain the location of the receiver.
[0076] Experiments performed by the applicant have demonstrated the effectiveness, the accuracy and the robustness of the proposed methods and systems.
[0077] The present invention concerns also a computer data carrier storing presentation content created with the described methods.
BRIEF DESCRIPTION OF THE DRAWINGS
[0078] The invention will be better understood with the aid of the description of an embodiment given by way of example and illustrated by the figures, in which:
[0079] FIG. 1A shows an example of trilateration as intersection of circles without jitter.
[0080] FIG. 1B shows an example of trilateration as intersection of circles with jitter.
[0081] FIG. 2 shows a room comprising a transmitter (source) and a set of receivers, the transmitter being localized based on TOA.
[0082] FIG. 3 shows a room comprising a transmitter (source) and a set of receivers, the transmitter being localized based on TDOA.
[0083] FIG. 4 shows a room comprising a transmitter (source) and a set of receivers, and an example of virtual sources of the first and second order.
[0084] FIG. 5A shows a room comprising a transmitter (source), and an example of a first order virtual source.
[0085] FIG. 5B shows a room comprising a transmitter (source), and an example of a first order virtual source, and a second order virtual source.
[0086] FIG. 6 illustrates an example of visibility of a second order virtual source. Although v 2;4 is visible by the microphone in wall ( 4 ), it will not be heard unless wall ( 2 ) extends until point a. With the illustrated room geometry, the microphone can only hear v 2;4 from intersection the two illustrated shades in top left corner.
[0087] FIG. 7 illustrated an example of labelling obstructive walls by using convex hull of the room. Two out of six represented walls are inside the convex hull of the room, thus it is necessary to check if the signal is blocked by only two walls.
[0088] FIG. 8A illustrates the times of arrivals of the echoes coming from the real source and from the virtual sources of FIG. 8B .
[0089] FIG. 8B illustrates a room comprising the real source and a set of receivers, and the virtual sources generated from the real source.
[0090] FIG. 9 shows an example of how reflecting (mirroring) a localized first order virtual source back into a room.
[0091] FIGS. 10A to 10C shows an example of three steps for reflecting (mirroring) a localized second order virtual source into the room using method of images in reverse order.
[0092] FIG. 11 illustrates recorded RIR by each microphone, and the simulated RIR from the estimated location.
[0093] FIG. 12 illustrates an embodiment of the optimization of position estimate.
[0094] FIG. 13 illustrates the dimensions of the L-shaped room used in source localization simulations.
[0095] FIGS. 14A and 14B show the global view respectively vicinity of the true source of the simulation results for localization in L-shaped room without measurement jitter.
[0096] FIGS. 15A and 15B show the global view respectively vicinity of the true source of the simulation results for localization in L-shaped room with jitter being i.i.d. centered Gaussian with σ=0.05.
[0097] FIGS. 16A and 16B shows the global view respectively vicinity of the true source of the simulation results for localization in a room with complex geometry, with jitter being i.i.d. centered Gaussian with σ=0.1.
[0098] FIG. 17A shows simulation results for tracking (using all of the steps except optimization) a moving source following the path where s 1 (t)=1+3 cos 3 (2πt/120) and s 2 (t)=6.5+2 sin 3 (2πt/120) for t=0, 1, 2 . . . 120, the jitter being i.i.d. with distribution ε i ˜N(0.0.05).
[0099] FIG. 17B shows simulation results for tracking (using only the optimization based on the previous estimate) a moving source following the path where s 1 (t)=4+3 cos 3 (2πt/120) and s 2 (t)=6.5+2 sin 3 (2πt/120) for t=0, 1, 2 . . . 120, the jitter being i.i.d. with distribution ε i ˜N(0.0.05).
[0100] FIGS. 18A to 18D illustrate the contours of formula (11) in 8×8 square room for the source position s=(4, 5) T , for one microphone (top) and three microphones (bottom) using direct and first order echoes. The contours on FIGS. 18A and 18C are for jitter-free measurements, and the contours on FIGS. 18B and 18D are for i.i.d centered Gaussian jitter with
[0000] σ=0.05.
[0101] FIG. 19 illustrate an example of the l 2 localization error.
[0102] FIGS. 20A and 20B illustrate the contours of formula (10) in 8×8 square room for the source position s=(4, 5) T , for one microphone ( FIG. 20A ) and three microphones ( FIG. 20B ) using direct and first order echoes. The contours are plotted for jitter free measurements and the microphone positions are same with FIGS. 18A to 18D .
[0103] FIG. 21 illustrates an embodiment of a system according to the invention.
[0104] FIG. 22 illustrates an embodiment of a data processing system in which a method in accordance with an embodiment of the present invention may be implemented.
DETAILED DESCRIPTION OF POSSIBLE EMBODIMENTS OF THE INVENTION
[0105] The present invention will be now described in more detail in connection with its embodiment for determining the location of a loudspeaker (or, in general, of a transmitter) by knowing the geometry of a room, i.e. the location and the orientation of its walls (or, in general, of its reflective surfaces), and the location of a set of microphones (or, in general, of a receivers). However the present invention finds applicability in connection with many other fields, as will be discussed. For example, the described method and system can be used for determining the location of a receiver by knowing the geometry of a room, i.e. the location and the orientation of its walls or reflective surfaces, and the location of a set of transmitters.
[0106] The present invention will be now described in more detail in connection with an ultrasonic signal. However the present invention finds applicability of connection with other kinds of signals, e.g. and in a non-limiting way a light signal, an RF signal, etc.
[0107] The present invention will be now described in more detail in connection with a room. The example described is with respect to a 2D room for ease of understanding of the principles of the present invention; however it will be understood that the invention can be applied, using the same principles, to a 3D room. It will also be understood that the present invention does not necessarily need to be applied in a room.
Notation
[0108] Throughout this application vectors are denoted as boldface letters, e.g. x. The position of the i th microphone is denoted as m i . Without loss of generality, one corner of the room is assumed to be at the origin, and the corners are numbered in counter clockwise direction starting from ‘1’ for the corner at the origin. The coordinates of the i th corner of the room are denoted by c i , and the unit outward normal vector of the i th wall is denoted by n i . The inner product between two vectors a and b is denoted as a, b =a T b, and ∥a∥ denotes the f 2 -norm of a defined as ∥a∥=√{square root over ( a, a )}. The coordinates of the source are denoted by sε 2 . The virtual sources (to be explained) generated by reflecting the source, in specified order, by the walls, i, j, k is denoted as v i,j,k .
DEFINITIONS AND PROPERTIES
Times of Arrivals—TOA
[0109] Times of arrivals are the measurements of the absolute propagation time for the signal to reach the microphones after being emitted by the source. TOA can be measured if there is synchronization between the microphones and the source, namely, if the microphones have the information about when the signal was emitted by the source.
Time Difference of Arrivals—TDOA
[0110] If the microphones do not know when the signal is emitted by the source, the absolute propagation time for signal to reach the microphones is unknown, thus TOA are not present. In this case one can measure the time difference of arrivals between microphones if they have a common time reference. This can be achieved by designating one of the microphones as the reference microphone, and finding the difference between the time when the signal reaches the reference microphone and the other microphones.
Direction of Arrival—DOA
[0111] Direction of arrival is the angle with respect to a predefined reference, which the signal is coming to a receiver.
Triangulation
[0112] Triangulation is determining the position of an object by measuring the angles between the object and predefined fixed anchors.
Trilateration
[0113] Trilateration is a method for finding the position of an object by using distance measurements to at least three anchors; in the case where one uses more than three anchors, the problem is called multilateration.
[0114] It should be noted that in TOA, TDOA and DOA preferably at least three receivers for unique localization in free space in 2D are used, and four in 3D.
[0115] It should be understood that in the present application the terms “virtual source” and “image source” are used interchangeably and both terms stand for mirror images of a true source across one or multiple walls. Image sources are used to model echoes. First order echoes can be seen as coming from first order image sources, and higher order echoes can be seen as coming from higher order image sources.
DESCRIPTION OF EMBODIMENTS
Localization Based on TOA
[0116] If times of arrivals are known, the distance from the source to the microphones can be found by using the speed of propagation of sound in air C=343.2 m/s (precise value depends on other factors such as the temperature). Then by trilateration, the position of the source can be found by intersecting the distance circles 1 a - d as shown in FIG. 1 a.
[0117] When the time of arrivals are present without measured error, the circles will intersect at a single point and the intersection gives the position of the source. However, if there is jitter in the distance measurements, the circles 1 a - d do not intersect at a single point as shown in FIG. 1 b . In that case one can pose an optimization problem to estimate the location of the source as is illustrated in FIG. 2 .
[0118] Referring to FIG. 2 , having measured distance r i of the source 2 to the i th microphone m 1 -m 4 (generalized as m i ) as:
[0000] r i =∥x−m i ∥+ε i ,i= 1,2, . . . , M,
[0000] where ε i is random measurement jitter and M is the number of microphones, the position of the source 2 can be estimated by finding the position in the 2D plane that minimizes the sum of the squares of the differences between the measured distances r 1 ,r 2 of the source 2 to the microphones and the distances between the microphones m 1 -m 4 (generalized as m i ) and the test position 7 . This optimization problem can be written as:
[0000]
minimize
x
∈
ℝ
2
∑
i
=
1
M
(
r
i
-
x
-
m
i
)
2
.
(
1
)
[0119] The solution to this problem yields the maximum likelihood estimator if errors follow a Gaussian distribution with covariance matrix proportional to the identity matrix. However, this problem is not convex, and there is no efficient algorithm to find the globally optimal solution. There are methods for approximating the solution, such as by semidefinite relaxation as disclosed in:
K. Cheung. W.-K. Ma, and H. So. “Accurate approximation algorithm for toa-based maximum likelihood mobile location using semidefinite programming,” in Acoustics, Speech, and Signal Processing. 2004 , Proceedings . ( ICASSP ' 04). IEEE International Conference on , vol. 2, 2004, pp. ii 145 8 vol. 2.
which is incorporated herein with reference.
[0121] However, it is reported that although semi-definite relaxation yields good results for some instances, it can perform badly if the relaxation is not tight as disclosed in
A. Beck. P. Stoica, and J. Li. “Exact and Approximate Solutions of Source Localization Problems.” Signal Processing, IEEE Transactions on , vol. 56, no. 5, pp. 1770 1778, 2008.
which is incorporated herein with reference.
[0123] Another optimization problem mentioned is the so called ‘squared-range-based least squares’ obtained by squaring the distances in (1) defined as:
[0000]
minimize
x
∈
ℝ
2
∑
i
=
1
M
(
x
-
m
i
2
-
r
i
2
)
2
(
2
)
[0124] Although this is still a nonconvex problem, the solution can be found efficiently and globally by the method described in the publication “Exact and Approximate Solutions of Source Localization Problems”.
[0125] To formulate the problem so that the solution can be found efficiently, first, we write it in constrained from as:
[0000]
minimize
x
∈
ℝ
2
∑
i
=
1
M
(
α
-
2
m
i
⊤
x
+
m
i
2
-
r
i
2
)
2
subject
to
x
2
=
α
.
[0126] By using the substitution y=(x T ,α) T the problem is written as:
[0000]
minimize
y
∈
ℝ
3
Ay
-
b
2
subject
to
y
⊤
Dy
+
2
f
⊤
y
=
0
,
where
A
=
(
-
2
m
1
-
1
⋮
⋮
-
2
m
M
⊤
1
)
,
b
=
(
r
1
2
-
m
1
2
⋮
⋮
r
M
2
-
m
M
2
)
,
And
,
D
=
(
I
2
0
2
×
1
0
1
×
2
0
)
,
f
=
(
0
2
×
1
-
0.5
)
.
(
3
)
[0127] The resulting problem consists of minimization of a quadratic objective subject to a single quadratic equality constraint, which are called generalized trust region sub-problems (GTRS) in optimization literature, as disclosed in:
J. J. Moré. “Generalizations of the trust region problem.” Optimization methods and Software, 1993.
which is incorporated here by reference.
[0129] It is shown that yε 3 is an optimal solution if and only if there exists ε such that λε :
[0000] ( A T A+λD ) y=A T b−λf
[0000] y T Dy+ 2 f T y= 0
[0000] A T A+λD≧ 0.
[0130] It follows that the optimal solution to (3) is given by:
[0000] {circumflex over ( y )}(λ)=( A T A+λD ) T ( A T b−λf ), (4)
[0131] Where λ is the unique solution of:
[0000] {circumflex over ( y )}( D ) T Dŷ (λ)−2 f T ŷ (λ)=0 (5)
[0000] over the interval where A T A+λD is positive definite. Interval satisfying this property can be found by using congruence transformations. By Sylvester's law of inertia, the matrix C T HC, where C is a non-singular matrix, has the same number of positive eigenvalues, negative eigenvalues and zero eigenvalue as matrix H, as is disclosed in:
G. Strang. Linear Algebra and Its Applications. 3rd. Brooks Cole. February 1988.
which is incorporated here by reference.
[0133] By saying that H is congruent to G if G=C T HC for some non-singular C and denoting this equivalence relation by H˜G, we have:
[0000] A T A+λD =( A T A ) 1/2 ( I +λ( A T A ) −1/2 D ( A T A ) −1/2 )( A T A ) 1/2 ˜I +λ( A T A ) −1/2 D ( A T A ) −1/2 .
[0000] since all of the matrices on the right hand side of the equation has nonnegative eigenvalues, it follows that:
[0000]
ℐ
=
(
-
1
λ
max
(
(
A
⊤
A
)
-
1
/
2
D
(
A
⊤
A
)
-
1
/
2
)
,
∞
)
.
[0134] It is given in the publication “Linear Algebra and Its Applications” that λ can be found by simple bisection algorithm since the function (5) is decreasing on the interval .
Localization Based on TDOA
[0135] Referring to FIG. 3 , setting one of the microphones (m 1 -m 4 ) (generalized as m i ) as the reference (denoting the reference microphone as ‘0’) and—without loss of generality—setting it as the origin (0,0), we define the range difference measurements between each microphone m i and reference microphone 0 as:
[0000] d i =∥s−m i ∥−∥s∥,i= 1,2, . . . , M.
[0136] Geometrically, the points in the 2D plane that have a fixed distance difference to two fixed anchors trace a hyperbola. Since distance difference to two anchors yield one hyperbola, if we have three or more microphones, we have multiple hyperbolas and in the presence of precise range difference measurements, the intersection of the hyperbolas yield the source position ‘s’. However, if there is jitter in the measurements and we have more than two hyperbolas, the hyperbolas will not intersect at a single point. In this case, we can solve an optimization problem to find the best position estimate for the source position ‘s’. Rewriting the range difference equality we have:
[0000] −2 d i ∥s∥− 2 m i T s=d i 2 −∥m i ∥ 2 ,i= 1,2, . . . , M,
[0000] which is satisfied in jitter-free measurements.
[0137] However when there is jitter, the equality does not hold, but a reasonable estimate for the source position ‘s’ can be found by solving so called squared-range-difference-based least squares problem:
[0000]
minimize
x
∈
ℝ
2
∑
i
=
1
M
(
-
2
m
i
⊤
x
-
2
d
i
x
-
g
i
)
2
,
(
6
)
[0000] where y i =d i 2 −∥m i ∥ 2 .
as is disclosed in
J. O. Smith and J. S. Abel. “Closed-form least-squares source location estimation from range-difference measurements.” Acoustics, Speech and Signal Processing. IEEE Transactions on , vol. 35, no. 12, pp. 1661 1669, 1987.
and
A. Beck, P. Stoica, and J. Li, “Exact and Approximate Solutions of Source Localization Problems.” Signal Processing. IEEE Transactions on , vol. 56, no. 5, pp. 1770 1778, 2008.
both of which are incorporated herein by reference.
[0140] A closed form solution to this problem is derived in the publication “Exact and Approximate Solutions of Source Localization Problems”. First, the problem is written in constraint form:
[0000]
minimize
y
∈
ℝ
3
B
y
-
g
2
subject
to
y
⊤
Cy
=
0
y
3
≥
0
,
where
y
=
(
x
⊤
x
)
⊤
and
B
=
(
-
2
m
1
⊤
-
2
d
1
⋮
⋮
-
2
m
M
⊤
-
2
d
m
)
,
C
=
(
I
2
0
2
×
1
0
1
×
2
-
1
)
.
(
7
)
[0141] It is shown in the publication “Exact and Approximate Solutions of Source Localization Problems” that the sufficient conditions for y to be the optimal point of the problem is there exists λε such that:
[0000] ( B T B+λC ) y=B T g
[0000] B T B+λC≧ 0
[0000] y T Cy= 0
[0000] y 3 ≧0.
[0142] Using the optimality conditions a procedure prototype is explained to find optimal solution as:
1. Find solution λ* to:
[0000] y (λ) T Cy (λ)=0,λε I 1 ,
[0000] Where
[0000] y (λ)=( B T B+λC ) −1 B T g,
and I 1 is the interval where B T B+λC is positive definite. 2. If the last entry of y(λ*) is nonnegative, i.e. for z=y(λ*) we have z 3 ≧0, then z is the global optimizer of the problem and position estimate can be found by taking the first two entries of z.
However, it might be the case that the resulting vector does not satisfy the condition z 3 ≧0. To find the global optimizer in this case the necessary optimality conditions derived in the publication “Exact and Approximate Solutions of Source Localization Problems” are used, which states that the optimal solution to (7) is either y=0 or has the form:
[0000] t (λ)=( B T B+λC ) −1 B T g,
where λ satisfies:
[0000] y (λ) T Cy (λ)=0.
[0000] and B T B+λC has at most one negative eigenvalue. The intervals of λ corresponding to these settings can be found by the congruence relation as before as:
[0000] B T B−λC =( B T B ) 1/2 ( I +λ( B T B ) −1/2 C ( B T B ) −1/2 )( B T B ) 1/2 ˜I +λ( B T B ) −1/2 C ( B T B ) −1/2 .
[0147] Defining the matrix:
[0000] V =( B T B ) −1/2 C ( B T B ) −1/2
[0000] and denoting the i th eigenvalue of V as λ i (V) where the eigenvalues are ordered in decreasing order as λ 1 ≧λ 2 ≧λ 3 . Since have B T B positive definite and C has 1 negative and 2 strictly positive eigenvalues, we have λ 1 ≧λ 2 ≧0≧λ 3 . From the congruence relation we see that signs of the eigenvalues of B T B+λC are the same with I+λV which has eigenvalues 1+λ·λ i (V). Using these facts there are three disjoint intervals where B T B+λC has at most 1 negative eigenvalue:
[0000]
1.
I
0
=
(
-
1
λ
3
(
V
)
,
?
)
:
gives
2
positive
1
negative
eigenvalues
2.
I
1
=
(
-
1
λ
1
(
V
)
,
-
1
λ
?
(
V
)
)
:
gives
3
positive
eigenvalues
3.
I
2
=
(
-
1
λ
2
(
V
)
,
-
1
λ
?
(
V
)
)
:
gives
2
positive
and
1
negative
eigenvalues
?
indicates text missing or illegible when filed
[0148] Using these intervals, the full procedure is defined as:
1. Find solution λ* to
[0000] y (λ) T Cy (λ)=0,λε I 1 .
[0000] Where
[0000] y (λ)=( B T B+λC ) −1 B T g.
If the last entry of y(λ*) is nonnegative, i.e. for z=y(λ*) we have z 3 ≧0, then z is the global optimizer of the problem and position estimate can be found by taking the first two entries of z. If z 3 <0 then perform steps 2 and 3. 2. Find all roots λ 1 , λ 2 , . . . , λ p of
[0000] y (λ) T Cy (λ)=0,λε I 0 ∪I 2 ,
for which third entry of Ills nonnegative. 3. Set z as the vector with smallest objective function among 0, y(λ 1 ), y(λ 2 ), . . . , y(λ p ). Take position estimate as the first two entries of z.
Method of Images
[0152] Method of images (also known as image source model) provides that reflections coming from walls can be viewed as direct signals coming from virtual sources. These virtual sources are obtained by mirroring the true source across the reflecting walls (possibly across multiple walls) as disclosed in:
J. Borish. “Extension of the image model to arbitrary polyhedra.” The Journal of the Acoustical Society of America. 1984.
which is incorporated herein by reference.
[0154] FIG. 4 provides an illustration of 1 st order virtual source V 1 and V 2 (generalized as v 1 ) generated from walls 5 , and 6 (generalized as i) respectively.
[0155] The positions of these virtual sources v i can be found by:
[0000]
v
i
=
s
-
2
n
i
⊤
(
s
-
p
i
)
n
i
=
s
-
2
N
i
(
s
-
p
i
)
.
(
8
)
[0000] where
[0000]
N
i
:=n
i
n
i
T
[0000] is the orthogonal projection operator onto the normal to wall i, and p i is any point belonging to the i th wall.
[0156] To find higher order virtual sources one can reflect the source across multiple walls, or equivalently reflect a virtual source across a wall, as:
[0000] v i,j =v i −2 N ( v i −p j ). (9)
[0157] By using the method of images, we are reducing the problem of localizing the source in a room, to localization of multiple sources in free space.
Problem Setup
[0158] One of the goals of the present invention is localization of a source which transmits a signal (e.g. an ultrasonic source or radio source) in a known reverberant room having general geometry, not limited to convex, bounded by at least some planar walls, from the measurements by a receiver (e.g. a microphone array). In the present description an example in which the source is an ultrasonic source and a receiver is a microphone array will be described, however it will be understood that the present invention is not limited to such an embodiment and other suitable types of sources and receivers can be used.
[0159] When the room is convex, assuming point microphones so they do not block the signals, the source is visible by all microphones in the microphone array (i.e. each microphone in the microphone array can receive a signal (such as an acoustic signal) which is emitted by the source). When the source is visible, all microphones (receivers) hear the direct signal, and the direct signal arrives before any echo. Thus, in the convex room setting, these direct signals can be used for the localization of the source, and it is reported that the performance of the localization algorithms decreases with reverberation, although there are notable exceptions.
[0160] In an exemplary problem setting of the present invention, the room is not assumed to be convex, thus there are positions in the room where the source is partially visible or not visible by the microphones in the microphone array (i.e. some microphone in the microphone array cannot directly receive a signal (such as an acoustic signal) which is emitted by the source), thus direct signal may not be heard. In the context of the present invention a “direct” signal is a signal which has not been reflected (e.g. which has not been reflected by a wall or object). However, the echoes reflecting from the walls are received by those microphones in the microphone array which do not receive the direct signal. In this setting, echoes are used, which in general makes the performance worse in the convex room, to localize the source in room with general geometry.
[0161] With reference to FIGS. 5A and 5B the proposed localization algorithm is as follows. The signal emitted by an ultrasonic source 7 is recorded with a microphone array. The echoes coming from different walls 5 , 6 may be received in different orders at each of the microphones in the array, or put in context of the method of images, signals coming from the virtual sources V 5 V 5,6 can be heard (i.e. received) in different orders by the microphones. Since the virtual source localization algorithms explained in above requires distances (or difference of distances in TDOA localization) to a single source in order to estimate its position, we need to find which echoes correspond to a single virtual source. After finding such echoes and localizing the virtual sources V 5 V 5,6 , we know if they are located inside or outside the room since the room geometry is known. In case we find that a virtual source is located a position inside the room we are done. However, if we find that a virtual source is located a position outside the room, we need to find the position inside the room that generates that virtual source, which we do by using the method of images in the reverse order. From the multiple localized and reflected sources, we find the position that best estimates the source position and optimize the estimation by using a measure based on the difference between the recorded and simulated recordings which will be described in more detail later.
Source Location Estimation
[0162] The building blocks of a method according to the present invention will now be described: the forward model for generating virtual sources given a source position inside the room, localization of virtual sources from the recordings by the microphone array, reflecting the localized virtual sources into the room, estimating the source position from multiple reflected sources and optimizing the position of the source location estimate.
Forward Model
[0163] In an embodiment of the present invention a forward model is used which generates the recordings by the microphone array given the room geometry, source position and the microphone positions. The approach used for the forward model in this exemplary embodiment is based on the method disclosed in:
J. B. Allen and D. A. Berkley, “Image method for efficiently simulating small-room acoustics.” The Journal of the Acoustical Society of America, 1979.
and
J. Borish, “Extension of the image model to arbitrary polyhedra,” The Journal of the Acoustical Society of America. 1984.
both of which are incorporated herein by reference.
[0166] The positions of the virtual sources can be found by the equations disclosed in the previous sections. For the generation of virtual sources and checking if each virtual source is heard by a microphone in a specific position, there are three aspects that need to be tested: validity, visibility and obstruction.
[0167] Validity: The virtual source needs to correspond to valid echoes. For a candidate virtual source to be valid, the generating source needs to be directly adjacent to that wall. An example of an invalid virtual source is reflecting a first generation virtual source back in the room, across the same wall that generated it in the first place. This would correspond to two consecutive bounces off the same wall, which is physically infeasible. Visibility: With reference to FIG. 6 in order for a virtual source V 2 V 2,4 to be heard by a microphone m 1 , virtual source needs to be visible in the wall 4 , 2 it was generated from. A virtual source is “visible” in a wall if a line joining the virtual source and microphone intersects that wall. In other words, the line joining the virtual V 2 V 2,4 source and the microphone m 1 should intersect the wall 4 , 2 that generates the virtual source. As can been seen in FIG. 6 the line joining virtual source V 2 and microphone m 1 does not intersect the wall 2 that generates the virtual source V 2 , while the line joining virtual source V 2,4 and microphone m 1 does intersect the wall 4 that generates the virtual source V 2,4 .
[0168] Although this is sufficient for a first order echo, for higher order echoes, one needs to check visibility also in the walls that were used to generate lower order virtual sources generating it, i.e., point of intersection ‘a’ of the generating wall and the line drawn between the virtual source V 2 V 2,4 and microphone m 1 needs to be visible from the parent walls generating the virtual source. A parent wall is a wall that is part of the sequence of walls (reflections) that lead to a particular image source. Visibility of an image source from a certain point means that the receiver at that point can hear the signal from the image source. Conditions for visibility of higher order image sources are also illustrated in FIG. 6 . Although V 2,4 is visible by the microphone in wall ( 4 ), it will not be heard by the microphone unless wall ( 2 ) extends to point a. With the illustrated room geometry, the microphone can only hear V 2,4 from the hatched region in the top left corner.
[0169] Obstructions: In a convex room, since convex combinations of any set of points belonging to the room is also inside the room there is no obstruction of the source. However, as shown in FIG. 7 when the room is not convex, there are walls 7 , 8 that may obstruct the line of sight between the microphones and the source. Hence, in non convex room, it is necessary to check if there is line of sight between the virtual source and the microphones. To this end, one can note that only the walls that violate the convexity can obstruct the line of sight, thus we may label these walls as ‘obstructive’ and check only if they are obstructing the line of sight in each iteration to reduce the number of tests. The ‘obstructive’ walls can be found by finding the convex hull of the room, and labelling which walls intersect its interior as shown in FIG. 7 .
[0170] Localization of Virtual Sources
[0171] In this section we discuss the localization of virtual sources in two settings, where we have TOA and TDOA. First we consider the case where we have the signals recorded by M microphones containing the TOA. At the receiver, we do not know whether the signal is coming directly from the source or through a reflection from a wall. In particular, if the signal is reflected, we do not know which wall(s) generate the reflection.
[0172] In order to localize the virtual sources, we take one arrival time from each microphone combinatorially and we calculate the range by multiplying it with the speed of sound, to obtain the distance r i between the virtual source and microphone where i=1, 2, . . . , M. FIG. 8B shows the virtual sources V 1 -V 4 generated by real source s and also shows microphones mic1-4 FIG. 8A shows the time of arrival at microphones mic1-4 of echoes coming from virtual sources V 1 -V 4 . From these ranges, we localize the position by using squared-range-based least squares algorithm to have a position estimate ŝ If the selected echoes correspond to a correct combination, i.e. they are generated by a single virtual source, the algorithm will produce a location whose distances to microphones match r i with high precision. However, if the echo combination used for localization does not come from a single virtual source, with very high probability, there will be no point in the 2D plane that will have these distances to the microphones. Based on this idea we define the localization score, G LOC that measures on how well the resulting distances and the input distances match as:
[0000]
G
LOC
(
s
^
)
:=
∑
i
=
1
M
(
s
^
-
m
i
-
r
i
)
2
.
[0173] Using this measure, we say that a particular combination of echoes corresponds to a single virtual source if the score is less than a chosen threshold.
[0174] In the case where we do not have TOA but TDOA, we use a similar approach to find correct echo combinations corresponding to a single virtual source. We designate one microphone as the reference microphone and—without loss of generality—assume it to be at the origin. Then we go through each pulse recorded in that reference microphone and we combinatorially take pulses one from other microphones and multiply the times by the speed of sound to obtain distances. Before using the chosen echo combination in the squared-range-difference-based least squares optimization, we shift the pulses so that the distance difference in the reference microphone equals to 0 (to have it indeed become the reference). Formally, if t i is the time instances of the selected pulses from microphones i=0,1, . . . , M−1 where microphone 0 is the reference, we define range-differences as d i =c(t i −t 0 ), where c is the speed of propagation of sound. Then we localize the virtual source using squared-range-difference-based least squares algorithm using distances d 1 , . . . , D M-1 and check if the echo combination was correct by evaluating range-difference localization score, G RDL , defined as:
[0000]
G
RDL
(
s
)
:=
∑
i
=
1
M
-
1
(
s
-
m
i
-
?
-
d
i
)
2
.
?
indicates text missing or illegible when filed
[0175] Again, we accept the chosen echo combination as coming from a single virtual source if the score is less than a threshold.
[0176] Reflecting Localized Virtual Sources
[0177] After finding the location of the virtual source, since the room geometry is known, one can use the method of images in reverse order to find the real source position that would have generated that virtual source.
[0178] Referring to FIG. 9 and FIG. 10A-C , in order to find the real source location, we draw the lines connecting the virtual source 10 to the microphones 11 a - d and find the wall 12 that intersects these lines. Then the virtual source is reflected across that wall as shown in FIG. 10 b , and the points of intersections on the wall are remembered. If the reflected source is inside the room, as shown in FIG. 9 , we are done. If not, as is the case in FIG. 10B , lines connecting the stored intersection points and the new virtual source 15 are drawn, as shown in FIG. 10B , and the virtual source is reflected across the new wall 13 of intersection, as is illustrated in FIG. 10C . This procedure is iterated until position inside room is found, as is shown in FIG. 10C . Thus illustration of this procedure is depicted in FIGS. 10A-C , where a second order virtual source is reflected into the room.
[0179] One problem that might occur while applying the inverse method of images is that the lines drawn to multiple microphones may intersect multiple walls. This may happen due to errors in virtual source localization or jitter. In that case one may choose to drop that localized virtual source or reflect across the wall with the highest number of intersections.
[0180] Estimating the Source Position
[0181] So far we have multiple localized virtual sources that are reflected inside the room. The remaining questions is how to pick the estimate position for the true source position. To this end, one may make use of the localization scores, G LOC (or G RDL for TDOA), of the virtual sources where the less G LOC is the closer the estimated virtual source is to the true one. However, as the measurement jitter increases, incorrect echo combinations start to mimic correct echo combinations coming from false virtual sources and give low localization scores. Hence, for stable localization in case of high measurement jitter, a different measure (score) of how good/accurate an position estimate is may be used:
[0182] We derive the score based on the following idea when we have TOA recordings. If the estimated source position is close to the true source, the simulated room impulse response from the estimated source will be close to the recorded one as shown in FIG. 11 . Using this idea we define a score measuring how close the simulated and the recorded impulse responses are by taking echo by echo recorded by each microphone and finding the closest peak in the simulated response. We then sum the squares of differences between these two. Mathematically, we define the RIR score, G RIR , as:
[0000]
G
RIR
(
s
^
)
:=
∑
i
=
1
M
∑
j
=
1
n
m
e
i
,
j
2
,
where
e
i
,
j
=
min
k
r
^
i
,
k
-
r
i
,
j
,
[0000] and r i,j is the j th pulse recorded by i th microphone, and {circumflex over (r)} i,k is the k th pulse that would have been recorded by the i th microphone if the source was at ŝ.
[0183] Using this measure, we pick the reflected source that gives the least G RIR as the estimate position.
[0184] Optimizing the Position Estimate
[0185] Above we have defined a score based on RIR to choose among the localized and reflected virtual sources the virtual source that accurately estimates the true source position. We can further improve the estimate by moving it inside the room so that the RIR score, G RIR , is minimized. FIG. 12 provides an illustration depicting the notation of optimization of position measurement.
[0186] Towards this end, we define the virtual source that simulates the echo closest in time to the j th echo recorded in i th microphone by {circumflex over (v)}(i,j) as:
[0000]
v
^
(
i
,
j
)
(
s
^
)
=
arg
min
k
r
i
,
j
-
ν
^
k
(
s
^
)
-
m
i
,
[0187] where we denote virtual sources of any order by single subscript. With this notation we define the RIR score again, this time as an explicit function of the estimated source position:
[0000]
G
RIR
(
s
^
)
=
∑
i
=
1
M
∑
j
(
r
i
,
j
-
ν
^
(
i
,
j
)
(
s
^
)
-
m
i
)
2
.
[0188] To minimize score one may solve the optimization:
[0000]
minimize
s
∈
?
ℝ
2
∑
i
=
1
M
∑
j
(
r
i
,
j
-
v
^
(
i
,
j
)
(
s
^
)
-
m
i
)
2
.
(
10
)
?
indicates text missing or illegible when filed
[0189] Although this problem is again non-convex, if the initial position estimate is good enough we can find the minimizer iteratively by using gradient descent, or any other local search technique. The gradient of the RIR with respect to the source position is calculated as:
[0000]
∇
G
RIR
(
s
^
)
=
∑
i
=
1
M
∑
j
2
(
∏
w
∈
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[0190] where the product is over the wall sequence that generates the virtual source {circumflex over (v)}(i,j). Then the position is optimized iteratively by setting:
[0000] ŝ←ŝ−η∇G RIR ({circumflex over ( s )}),
[0191] where η≧0 is the learning rate. The algorithm may be stopped when the l 2 norm of the update in the source position is smaller than a predefined positive threshold.
[0192] Given the measurements with jitter, ε i,k resulting from the virtual source v k obtained from true source position in microphone i as:
[0000] r i,k =∥v k −m i ∥+ε i,k
[0000] we solve the optimization problem:
[0000]
minimize
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[0193] If the jitter is i.i.d. Gaussian, the optimization problem gives the source position that will generate the echoes with maximum likelihood. Denoting the likelihood of obtaining the set of recorded echoes as:
[0000]
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[0194] and taking negative logarithm to get the negative log-likelihood, we have:
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[0000] where const is a constant that depends on σ. Maximizing the likelihood is equivalent to minimizing the negative log-likelihood, which yields (11). Hence, by solving (11) we obtain the maximum likelihood estimator for the position that generates the set of recorded pulses.
[0195] However, since the signals coming from the virtual sources are unlabeled, we do not have direct access to r i,k , thus we do not know:
[0000] r i,k −∥{circumflex over (v)} k −m i ∥.
[0196] The minimization problem (10) can be viewed as a heuristic method aiming to solve (11), that estimates
[0000] r i,k −∥{circumflex over (v)} k −m i ∥
[0000] by taking the virtual source that gives the closest time difference to r i,k .
Simulations
[0197] We will now present simulation results of the present invention for source localization with TOA measurements. First the results of localization in an L-shaped room with and without measurement jitter will be shown. Then it will be shown how the present invention performs for room with complex geometry that has no parallel walls and conclude by applying the present invention to tracking a moving source.
[0198] It should be noted that in all of the FIGS. 13-21 , blank circles denote microphone positions and black dots depicts the true source position. Squares are localized and reflected virtual source ordered by their localization score where smaller index denotes better localization score. The striped dot marks the reflected virtual source that has the best RIR score, and the crossed dot is the result of optimization algorithm based on the position of striped dot.
Source Localization
[0199] For testing the developed indoor localization algorithm, we take a typical nonconvex room having L-shaped geometry shown in FIG. 13 .
[0200] Referring to FIGS. 14A-16B , to test the performance of the localization algorithm without jitter we position the source at (6,7) and use four microphones m 1 -m 4 positioned randomly by uniform distribution over the square region with bottom left corner at (1,1) and upper right corner at (3,3) to record the signal up to third order echoes. It is important to note that with this setting, there is no line of sight between the source and any of the microphones.
[0201] An outcome of the localization from jitter-free measurements can be seen in FIGS. 14 A,B. It can be seen that the present invention finds estimates close to the true source position, and the localization scores mark positions close to the true source as begin good. It is also seen that the RIR score chooses within reflected virtual sources the closest one to the true source position. The crossed dot that depicts the outcome of the optimization algorithm based on the position of the striped dot is seen to perfectly localize the source.
[0202] FIGS. 15 A,B shows an outcome of localization when there is measurement jitter drawn i.i.d. from centered Gaussian with σ=0.05. It is seen that although there are reflected sources in the vicinity of the true source position, the best reflected sources in terms of localization scores are away from it. Thus picking the reflected source having best localization score as the estimate of the true source position is not a valid option. However, also here, the reflected source having the best RIR score is the one closest to the true source position and the estimate is further improved by applying the optimization step based on that position.
[0203] As the last localization simulation we show the result of using the present invention for a room with very complex geometry with measurement jitter drawn i.i.d. from centered Gaussian with σ=0.1. As can be seen in FIGS. 16 A,B although the reflected sources are distributed in a broad range, the vicinity of the true source position is still dense. Furthermore, although the positions having best localization scores are distributed, the RIR score picks the one that is closest to the true source position and optimization algorithm gives an even closer estimate.
Source Tracking
[0204] One approach for source tracking is by taking measurements at distinct time instances and localizing the position independently of the previous ones. However, since the position of the source depends on its history, one can leverage the previous positions estimates in localizing the source.
[0205] In this simulation we compare the performance of tracking a moving source with two approaches. First approach is by going through all of the steps of the algorithm by recording the signal, finding echoes corresponding to virtual sources and localizing them, reflecting the localized virtual sources and taking the one giving the highest RIR score but not applying the optimization algorithm. The second method is by localizing first position by using first method and in addition applying optimization algorithm and for other time instances, applying only optimization algorithm based on the position estimate of the previous time instance.
[0206] FIGS. 17 A,B show the results of the two approaches where the source traces the curve:
[0000] sε 2 ,
[0000] where,
[0000] s 1 ( t )=4−3 cos 3 (2π t/ 120)
[0207] and s 2 (t)=6.5+2 sin 3 (2πt/120) for t=0, 1, 2, . . . , 120, and the jitter is drawn i.i.d. from centered Gaussian with σ=0.05.
[0208] FIG. 17A shows the result of the first approach and FIG. 17B shows the result of the second approach. As can be seen the second approach outperforms the first approach while being computationally lighter.
[0209] We will now discuss the objective functions behind the optimization step and plot average localization error for special case of square room through simulations.
[0210] FIG. 18A-D show the contours of the function (11) which the present invention aims to minimize by solving the heuristic optimization (10). The contours are drawn for a square room of size 8×8 for the source position of:
[0000] s =(4,5) T
[0211] and first order virtual sources generated from this position.
[0212] FIGS. 18A and 18B show the contours for one microphone for measurements without jitter ( FIG. 18A ) and with jitter ( FIG. 18B ). As can be seen, when there is no jitter in the measurements, the contours are smooth and the optimal position can be found, e.g., by gradient descent algorithm. With jitter, the contours gets distorted and local minima can occur, hence gradient descent algorithm may get stuck in local minima. However, as seen from FIGS. 18A and 18B as the number of microphones increase the cost curves becomes smoother with for same jitter level.
[0213] FIG. 19 shows the average l 2 localization error defined as the Euclidean distance between the true source and the estimated source positions, i.e.
[0000]
E
l
2
:=∥s−ŝ∥.
[0214] In order to find the optimal position, the algorithm is started from the vicinity of true source position and gradient descent algorithm is used. The plot shows that localization error based on minimization of (11) increases smoothly as the jitter is increased.
[0215] However, as explained in earlier above, since we do not have the labels for the echoes, we cannot minimize (11) so we estimate its solution by using the heuristic method (10). The contours for the (10) are plotted in FIG. 10A for jitter free measurements using one microphone, and are plotted in FIG. 10E for jitter free measurements using three microphones. As can be seen, the resulting function has local minima, hence gradient descent algorithm may get stuck at local minima. However, as also can be seen by comparing the two plots, as the number of microphones increases the contours become smoother, and if the starting point of the algorithm is close enough to the optimal position, one can find the global minimizer by the gradient descent algorithm.
FURTHER ASPECTS OF THE PRESENT INVENTION
[0216] Finally, we will now describe FIG. 21 which illustrates an embodiment of a system according to the invention and FIG. 22 which illustrates an embodiment of a data processing system in which a method in accordance with an embodiment of the present invention may be implemented.
[0217] FIG. 22 is an embodiment of a data processing system 300 in which an embodiment of a method of the present invention may be implemented. The data processing system 300 of FIG. 22 may be located and/or otherwise operate at any node of a computer network, that may exemplarily comprise clients, servers, etc., and it is not illustrated in the Figure. In the embodiment illustrated in FIG. 22 , data processing system 300 includes communications fabric 302 , which provides communications between processor unit 304 , memory 306 , persistent storage 308 , communications unit 310 , input/output (I/O) unit 312 , and display 314 .
[0218] Processor unit 304 serves to execute instructions for software that may be loaded into memory 306 . Processor unit 304 may be a set of one or more processors or may be a multi-processor core, depending on the particular implementation. Further, processor unit 304 may be implemented using one or more heterogeneous processor systems in which a main processor is present with secondary processors on a single chip. As another illustrative example, the processor unit 304 may be a symmetric multi-processor system containing multiple processors of the same type.
[0219] In some embodiments, the memory 306 shown in FIG. 22 may be a random access memory or any other suitable volatile or non-volatile storage device. The persistent storage 308 may take various forms depending on the particular implementation. For example, the persistent storage 308 may contain one or more components or devices. The persistent storage 308 may be a hard drive, a flash memory, a rewritable optical disk, a rewritable magnetic tape, or some combination of the above. The media used by the persistent storage 308 also may be removable such as, but not limited to, a removable hard drive.
[0220] The communications unit 310 shown in FIG. 22 provides for communications with other data processing systems or devices. In these examples, communications unit 310 is a network interface card. Modems, cable modem and Ethernet cards are just a few of the currently available types of network interface adapters. Communications unit 310 may provide communications through the use of either or both physical and wireless communications links.
[0221] The input/output unit 312 shown in FIG. 22 enables input and output of data with other devices that may be connected to data processing system 300 . In some embodiments, input/output unit 312 may provide a connection for user input through a keyboard and mouse. Further, input/output unit 312 may send output to a printer. Display 314 provides a mechanism to display information to a user.
[0222] Instructions for the operating system and applications or programs are located on the persistent storage 308 . These instructions may be loaded into the memory 306 for execution by processor unit 304 . The processes of the different embodiments may be performed by processor unit 304 using computer implemented instructions, which may be located in a memory, such as memory 306 . These instructions are referred to as program code, computer usable program code, or computer readable program code that may be read and executed by a processor in processor unit 304 . The program code in the different embodiments may be embodied on different physical or tangible computer readable media, such as memory 306 or persistent storage 308 .
[0223] Program code 316 is located in a functional form on the computer readable media 318 that is selectively removable and may be loaded onto or transferred to data processing system 300 for execution by processor unit 304 . Program code 316 and computer readable media 318 form a computer program product 320 in these examples. In one example, the computer readable media 318 may be in a tangible form, such as, for example, an optical or magnetic disc that is inserted or placed into a drive or other device that is part of persistent storage 308 for transfer onto a storage device, such as a hard drive that is part of persistent storage 308 . In a tangible form, the computer readable media 318 also may take the form of a persistent storage, such as a hard drive, a thumb drive, or a flash memory that is connected to data processing system 300 . The tangible form of computer readable media 318 is also referred to as computer recordable storage media. In some instances, computer readable media 318 may not be removable.
[0224] Alternatively, the program code 316 may be transferred to data processing system 300 from computer readable media 318 through a communications link to communications unit 310 and/or through a connection to input/output unit 312 . The communications link and/or the connection may be physical or wireless in the illustrative examples. The computer readable media also may take the form of non-tangible media, such as communications links or wireless transmissions containing the program code.
[0225] The different components illustrated for data processing system 300 are not meant to provide architectural limitations to the manner in which different embodiments may be implemented. The different illustrative embodiments may be implemented in a data processing system including components in addition to or in place of those illustrated for data processing system 300 . Other components shown in FIG. 22 can be varied from the illustrative examples shown. For example, a storage device in data processing system 300 is any hardware apparatus that may store data. Memory 306 , persistent storage 308 , and computer readable media 318 are examples of storage devices in a tangible form.
[0226] Therefore, as explained at least in connection with FIG. 22 the present invention is as well directed to a system for determining location of an object, a computer program product for determining location of an object and a computer data carrier.
[0227] In accordance with a further embodiment of the present invention is provided for a computer data carrier storing presentation content created while employing the methods of the present invention.
[0228] Although the present invention has been described in more detail in connection with its embodiment for determining the location of a loudspeaker or a microphone, the present invention finds applicability of connection with many other fields.
[0229] The present invention can be used for determining the exact position of a receiver r, which is a person in the FIG. 21 . In the case a satellite, e.g. a GPS satellite is the source s of a radio signal which can be reflected by some buildings B1, B2. If the echo e1 is not used, the localisation of a mobile device r of a person can be computed incorrectly (the mobile device r will be considered located in correspondence of {tilde over (e)}).
[0230] Knowing the position of the satellite s, the position of the buildings B1, B2, etc. (this is possible e.g. by using an electronic map) and applying the method according to the invention, it is possible to accurately locate the mobile device r and then the person, without any error. | A method for determining the location of a transmitter (respectively a receiver) in a space defined by one or more reflective surfaces, including the steps of sending a signal from the transmitter (respectively from a set of transmitters); receiving by a set of receivers (respectively by a receiver) the transmitted signal and echoes of the transmitted signal reflected by the reflective surfaces; finding by a first computing module the location of the virtual sources (respectively virtual receivers) of the echoes; mirroring by a second computing module the virtual sources (respectively virtual receivers) into the space and obtained mirrored virtual sources (respectively mirrored virtual receivers); combining by a third computing module the mirrored virtual sources (respectively mirrored virtual receivers) so as to obtain location of the transmitter (respectively the receiver). This method makes use of echoes for localizing the source (respectively receiver) when there is no line of sight between the transmitter(s) and the receiver(s). | 7 |
FIELD OF THE INVENTION
[0001] This invention generally relates to the field of motor driven pool cleaning vehicle. More particularly, this invention relates to the structure for driving the pool cleaning vehicle located outside the interior volume of the housing of the pool cleaning vehicle.
BACKGROUND OF THE INVENTION
[0002] As shown in FIGS. 1 and 2 , there are two basic kinds of pool cleaning vehicles. With particular reference to FIGS. 2 , there is shown the wheel embodiment of the pool cleaning vehicle 200 . The pool cleaning vehicle 200 has a housing 202 defining a body and the body having an interior space (not shown). Within the interior space is the drive motor (not shown). The drive motor is connected to the drive wheels by a belt (not shown). As the rotor of the drive motor rotates the belt (not shown) move in connection therewith. The drive wheels 204 are connected to the belt and rotates corresponding to the belt and motor.
[0003] As can be easily seen from FIGS. 1 and 2 , the belt is both inside and outside the interior. This means that the belt is exposed to the sun's uv rays and the pool's chemicals. Consequently, the belt cracks and loses its elasticity prematurely. Such premature wear is costly to the consumer and result is consumer dissatisfaction and great inconvenience.
[0004] Similarly with respect to FIG. 2 , the roller drive embodiment 200 a is belt driven and works in much the way as the wheel driven embodiment. In this embodiment, the drive roller 204 a is connected to output of the motor. Consequently the drive roller rotates corresponding the rotations of the motor. As in the earlier embodiment, the motor is located within the interior of the housing 202 a.
[0005] As described above, both embodiments include the drive motor within the interior space. In both embodiments the filter bag for collecting reft the from the filtered water. Quite clearly, the smaller the interior space, the less refuse can be collected. Thus, there is a need for increasing the space available for refuse collection and for doing so in a manner, which allows the pool cleaning vehicle to maintain all of its functions.
[0006] In order to increase the useable Interior space, it would be advantageous to reduce the number of elements in the housing of the pool cleaning vehicle.
[0007] Additionally, as the pool cleaning vehicle travels around the pool, it runs over various obstacles. Additionally, the elevation in the pool changes somewhat dramatically. It has been found helpful, just like in automobiles, to have a center of gravity that is lower rather than higher.
[0008] What is needed is a pool cleaning vehicle which maximizes interior space and also lowers the center of gravity, while allowing the pool cleaning vehicle to function in its normal manner.
SUMMARY OF THE INVENTION
[0009] The structure, in accordance with the present invention, is an internal drive assembly for a pool cleaning vehicle. The internal drive moves the motor assembly from the interior of the pool cleaning vehicle to a location in close proximity to the drive assembly for the pool cleaning vehicle.
[0010] Thus, It is an object of this invention is to provide an internal drive assembly for a pool cleaning vehicle which is location outside of the interior of the pool cleaning vehicle to provide greater space for the filtering assembly.
[0011] It is an additional object of this invention to provide such internal drive assembly for a pool cleaning vehicle having a roller drive assembly has the internal drive assembly located within the drive roller itself.
[0012] In accordance with the objects set forth above and as will be described and as will become herein, the internal drive assembly in accordance with this invention, comprises:
[0013] an internal drive propulsion assembly for a pool cleaning vehicle, the vehicle including a housing defining a body shell and the body shell having an interior for storage of a filter bag, and the pool cleaning vehicle including a drive mechanism including drive means for traveling around the underwater surface of the pool, the internal drive propulsion assembly comprising:
[0014] motor means for propelling the drive mechanism, the motor means mounted outside the interior of the body shell.
[0015] Additionally, in another exemplary embodiment, the vehicle includes a microprocessor. The microprocessor controls the movement of the vehicle, including left and right turns and its ability to escape from various obstacles.
[0016] In an exemplary embodiment of the internal drive assembly in accordance with the invention, the drive motor assembly is located within the drive roller embodiment of the pool cleaning vehicle. The drive assembly includes a gear assembly and the gear assembly is connected to the internal gear assembly of the drive roller, which, upon activation of the motor assembly correspondingly moves the drive roller.
[0017] In the wheel embodiment of the pool cleaning vehicle in accordance with the invention, the drive motor assembly is located outside the interior of the body shell and the internal drive assembly including a gear assembly is in close proximity to the drive wheel assembly and the drive wheel assembly including a gear assembly for mating connection with the internal drive gear assembly. Upon activation of the motor, the drive wheels correspondingly move.
[0018] It is an advantage of this invention to provide an internal drive assembly located outside of the interior body shell of the pool cleaning device.
BRIEF DESCRIPTION OF THE DRAWING
[0019] For a further understanding of the objects and advantages of the present invention, reference should be had to the following detailed description, taken in conjunction with the accompanying drawing, in which like parts are given like reference numerals and wherein:
[0020] FIG. 1 is a belt driven prior art pool cleaning device exhibiting a roller drive embodiment.
[0021] FIG. 2 is a gear driven prior art pool cleaning device exhibiting a wheel drive embodiment.
[0022] FIG. 3 is a perspective plan view of a single gear embodiment of the internal drive assembly in accordance with this invention.
[0023] FIG. 4 is a perspective plan view of one multiple gear embodiment of the internal drive assembly in accordance with this invention.
[0024] FIG. 5 is a perspective plan view of another multiple gear embodiment of the internal drive assembly in accordance with this invention.
[0025] FIG. 6 is a perspective view of one exemplary embodiment of the roller drive pool cleaning vehicle having the internal drive assembly in accordance with this invention.
[0026] FIG. 7 is a perspective view of the drive gear assembly in the roller drive embodiment for the internal drive assembly in accordance with this invention.
[0027] FIG. 8 is a cross sectional view of the gear assembly of FIG. 7 .
DETAILED DESCRIPTION OF THE INVENTION
[0028] An exemplary embodiment of the internal drive assembly for a pool cleaning device 20 in accordance with the present invention generally denoted by the numeral 50 will now be described with reference to FIGS. 3-8 .
[0029] Illustrated in FIGS. 3-5 is the embodiment of the pool cleaning vehicle which includes drive wheels 30 . The internal drive assembly 50 includes a motor (not shown) with a housing 52 mounted on the exterior 22 of the pool cleaning vehicle 20 . The motor includes a pinion gear 54 , mounted on the rotor. When the motor rotates clearly so does the pinion gear.
[0030] The drive wheel 30 is securely and removeably mounted on an axle 32 , in a manner conventional with pool cleaning vehicles. The drive wheel 30 includes an internal gear 34 having an opening 36 concentric with the axle opening of the drive wheel 30 . Similar to the drive wheel 30 , the gear 34 slides over the axle 32 and fits securely on the axle 32 so that the pinion gear 54 meshes properly with the internal gear 34 . Thus, when the motor rotor turns, the drive wheel 30 turns.
[0031] The drive wheel 30 is locked in placed by a lock washer 38 . The lock washer 38 is mounted concentric with the internal gear opening 36 and drive wheel 30 .
[0032] The internal gear 34 in one embodiment is a separate element which is located as shown in FIG. 3 . In another embodiment, the gear 34 is formed as an integral part of the wheel 30 .
[0033] The housing 52 hermetically seals the drive motor. This protects the motor against damage that can be caused by the pool water and similar environmental issues. The drive wheel 30 rotates freely on the axle 32 . And, as mentioned above does so in response to rotation by the motor.
[0034] It will be appreciated that, although not shown, within the housing 52 , the motor, in another embodiment includes reduction gearing. This has the advantage of reducing drag and consequently wear. As is appreciated by those skilled in the art, the greater the rotation and speed of the motor the greater the wear rate on the seal. Therefore, by reducing the gearing and turning the motor slower as the rotor or shaft exits the housing, the sealed casing is maintained longer.
[0035] With particular reference to FIG. 4 , there is shown another embodiment of the internal drive assembly 50 . Here, the elements are the same as FIG. 3 with the exception that additional gear 56 is included. The additional gear 56 in one embodiment works as an idler gear. This allows the vehicle to move the motor mass to an appropriate location as a result of the buoyancy of the vehicle.
[0036] In another embodiment, the additional gear 56 serves as a further reduction gear for the drive assembly. In another embodiment, the additional gear is used to drive another device. Thus, the same motor is used to drive more than one device.
[0037] With particular reference to FIG. 5 , there is shown a multiple additional gear embodiment of the internal drive assembly 50 . As will be appreciated, as many as three additional gears may be included in the internal drive assembly in accordance with the invention herein. In other embodiments, 3 or more idler gears are used. With particular reference to FIG. 5 , there are three additional gears, 56 , 58 and 60 . In this embodiment at least 2 of the gears serve as idler gears.
[0038] In this embodiment, wear and tear is shared among the number of idler gears, which could be as many as three. In other embodiments, more than three gears can be used. Also, this embodiment allows the distance between the output shaft and the wheel axle to be reduced. Finally, as can be seen from FIG. 5 , the entire internal drive assembly 50 is enclosed by the drive wheel 30 . In an additional embodiment the entire internal drive assembly is sealed by the enclosure.
[0039] In the embodiment shown in FIG. 5 , the motor drive housing includes a bearing 62 for supporting and aligning the drive wheel 30 . The bearing 62 in another embodiment is in the form of a bushing.
[0040] With particular respect to FIGS. 6-8 , there is shown is the embodiment of the pool cleaning vehicle which includes roller drive 40 instead of wheels 30 . The roller drive 40 has an interior 42 . Within the interior 42 is a motor assembly mounting bracket 44 . The mounting bracket 44 includes a journal 46 .
[0041] The motor assembly slides into position in the interior 42 of the roller drive 40 . A locking ring 70 includes a detent 72 extending therefrom. The detent 72 is sized and shaped to fit in the journal 46 . Upon complete insertion into the interior 42 , the motor assembly is journaled within the interior 42 .
[0042] As shown in FIGS. 7 and 8 , the drive roller 40 includes an internal gear 49 . In the embodiment shown in FIGS. 6-8 , there is shown the embodiment similar to FIG. 5 , except there are only two idler gears 58 and 60 and pinion gear 54 . And, similarly, the internal drive assembly works in the same fashion as described with respect to the earlier described embodiments in FIGS. 3-5 .
[0043] While the foregoing detailed description has described several embodiments of the internal drive assembly in accordance with this invention, it is to be understood that the above description is illustrative only and not limiting of the disclosed invention. Particularly, there are variety of propulsion assembly used by pool cleaning vehicle and each of them is within the spirit and scope of the invention providing the drive motor is located outside the interior of the body shell. It also will be appreciated that there are various modifications to the internal drive that are within the spirit and scope of the invention herein and that of particular interest is the ability of the motor assembly to remain outside the interior of the body shell and not the specific type of gearing or drive chosen for operation. Thus, the invention is to be limited only by the claims as set forth below. | Disclosed herein is a pool cleaning device including an internal drive assembly mounted outside the interior cavity of the device housing. The device including a pool cleaning vehicle, the vehicle including a housing defining a body shell and the body shell including an interior cavity and the pool cleaning vehicle including a drive assembly; and an internal drive assembly, the internal drive assembly including a motor assembly for engaging the vehicle drive assembly for propelling the vehicle, the motor assembly mounted outside the interior of the body shell. | 4 |
[0001] The present invention is related to the field of methods for detecting the interaction of proteins via the use of fusion proteins, commonly referred to as split-protein sensors or two-hybrid assays.
[0002] The introduction of the yeast-two hybrid system by Fields and Song in 1989 was a milestone for the analysis of protein-protein interactions in living cells (cf. U.S. Pat. No. 5,667,973 and Fields, S., and Song, O. (1989), Nature 340, 245-246). However, a major limitation of this classical two-hybrid system lies in its restriction to the detection of those protein-protein interactions that can be reproduced within the nucleus of a yeast cell. To overcome this restriction, an alternative to this two-hybrid method was introduced in 1994 by Johnsson and Varshavsky (cf. WO 95/29195 and Johnsson, N., and Varshavsky, A. (1994), Proc Natl Acad Sci USA 91, 10340-10344). Here, the two interacting proteins are expressed as fusion proteins with an N- and a C-terminal fragment of ubiquitin. Upon interaction of the two proteins a quasi-native ubiquitin is formed and subsequently recognized by ubiquitin-specific proteases, resulting in the cleavage of a reporter protein from the C-terminal fragment of ubiquitin. The split-ubiquitin system allows for the detection of interactions between cytoplasmic as well as membrane proteins. Since the introduction of split-ubiquitin, a variety of other split-protein sensors has been developed, including pairs of fragments of dihydrofolate reductase (DHFR), β-galactosidase, β-lactamase, inteins, green fluorescent protein (GFP), cAMP cyclase, glycinamide ribonucleotide transformylase, aminoglycoside phosphotransferase, hygromycin B phosphotransferase, and luciferase (cf. Remy, I., and Michnick, S. W. (1999), Proc Natl Acad Sci USA 96, 5394-5399; Rossi, F., Charlton, C. A., and Blau, H. M. (1997), Proc Natl Acad Sci USA 94, 8405-8410; Galarneau, A., Primeau, M., Trudeau, L. E., and Michnick, S. W. (2002), Nat Biotechnol 20, 619-622; Wehrman, T., Kleaveland, B., Her, J. H., Balint, R. F., and Blau, H. M. (2002), Proc Natl Acad Sci USA 99, 3469-3474; Ozawa, T., Nogami, S., Sato, M., Ohya, Y., and Umezawa, Y. (2000), Anal Chem 72, 5151-5157; Ozawa, T., Kaihara, A., Sato, M., Tachihara, K., and Umezawa, Y. (2001), Anal Chem 73, 2516-2521; Ghosh, I., Hamilton, A. D., and Regan, L. (2000), Journal of the American Chemical Society 122, 5658-5659). Among these systems only split-ubiquitin was successfully applied to screen for binding partners. Other sensors were used to monitor the interactions between selected pairs of proteins rather than to find new partners by a random library approach. Robust systems that can be used for identifying interaction partners at any location inside the cell and in different hosts are therefore still needed. Ideally the interaction-induced reassociation of such a split-protein sensor would provide the cell with a growth advantage thus allowing a selection for interacting proteins. However, generating new split-protein sensors is technically demanding as it depends critically on identifying suitable fragments that can reconstitute a native-like and active protein. The chosen fragmentation site has to fulfill at least the following criteria: (i) to yield two fragments that efficiently fold into quasi-native protein only when fused to two interacting proteins; (ii) not to significantly impair the activity of the reconstituted protein; (iii) to yield soluble protein fragments that are not readily degraded in vivo. In previous studies, the challenge of rationally finding such sites has been mostly tackled by trial and error.
[0003] It is thus an object of the present invention to overcome the above-mentioned drawbacks of the prior art, i.e. to provide a method for identification of suitable fragmentation sites in a reporter protein especially for use as a split-protein sensor, that is not limited by the above-mentioned drawbacks of rational design, and which especially allows for the identification of suitable fragmentation sites in a reporter protein even in the absence of any structural information such as a crystal structure. Further objects of the invention will become apparent to the person of routine skill in the art in view of the following detailed description of the invention.
[0004] This object and yet further objects are achieved inter alia by a method for the identification of suitable fragmentation sites in a reporter protein, and related thereto, recombinant DNA sequences and, encoded thereby, first and complementary second subdomains of a reporter protein, host cell lines transformed with said recombinant DNA sequences, a kit of parts comprising DNA-based expression vectors, a method for detecting an interaction between proteins, a use of random circular permutation and a use of a host cell line allowing for homologous recombination according to the independent claims.
[0005] Most biological processes are controlled by protein-protein interactions and split-protein sensors have become one of the few available tools for the characterization and identification of protein-protein interactions in living cells. Here we introduce a generally applicable combinatorial approach for the generation of new split-protein sensors and apply it to the (β/α) 8 -barrel enzyme N-(5′-phosphoribosyl)-anthranilate isomerase Trp1p from Saccharomyces cerevisiae (cf. Braus, G. H., Luger, K., Paravicini, G., Schmidheini, T., Kirschner, K., and Hutter, R. (1988), J Biol Chem 263, 7868-7875). These so-called split-Trp protein sensors are capable of monitoring the interactions of pairs of cytosolic and membrane proteins. One of the selected split-Trp pairs ( 44 N trp and 44 C trp ) was chosen by means of an example and successfully applied to monitor protein-protein interactions both at the membrane as well as in the cytosol of yeast. Its selected fragmentation site would not have been easily predicted by theoretical considerations, thus underlining the power of the evolutionary approach according to the invention. The direct read-out through complementation of tryptophan auxotrophy qualifies the split-Trp system for high-throughput applications in yeast and bacteria. Of course, appropriately engineered trp1-deficient host strains are required for such assays, which are however either readily available or easily to be made by the person of routine skill in the art. In addition, the introduced combinatorial approach allows for generating split-protein sensors of almost any reporter protein, thereby yielding tailor-made sensors for different applications.
[0006] Trp1p is a relatively small (25 kD), monomeric protein that catalyzes the isomerization of N-(5′-phosphoribosyl)-anthranilate in the biosynthesis of tryptophan (cf. Eberhard, M., Tsai-Pflugfelder, M., Bolewska, K., Hommel, U., and Kirschner, K. (1995), Biochemistry 34, 5419-5428). The DNA coding sequence of Saccharomyces cerevisiae is given in SEQ ID NO: 1, the corresponding amino acid sequence is given in SEQ ID NO: 2. Creating a pair of Trp1p fragments (split-Trp) that only reconstitute the enzymatic activity when linked to interacting proteins allows monitoring this protein interaction through a simple growth assay: otherwise trp1 yeast strains expressing such a split-Trp fusion pair would not be able to grow on medium lacking tryptophan. As many different trp1 strains exist, the interaction assay could be applied immediately in different genetic backgrounds, adding a further attractive feature to a split-Trp sensor. Trp1p is a well-studied member of the prominent class of proteins that fold into a (β/α) 8 -barrel, which is the most commonly occurring fold among enzymes. The herein presented approach of identifying suitable fragmentation sites in a reporter protein is thus very broadly applicable. This folding motive has been previously subjected to circular permutation and has been expressed as two separate fragments that spontaneously associate into a functional enzyme (cf. Luger, K., Hommel, U., Herold, M., Hofsteenge, J., and Kirschner, K. (1989), Science 243, 206-210; Eder, J., and Kirschner, K. (1992), Biochemistry 31, 3617-3625). Furthermore, it has been proposed that the (β/α) 8 -barrel evolved by tandem duplication from a (β/α) 4 -domain (cf. Hocker, B., Schmidt, S., and Sterner, R. (2002), FEBS Lett 510, 133-135). In addition to any practical applications it would therefore add to our understanding where the (β/α) 8 -barrel can be split into two fragments that, in contrast to previously described pairs of fragments, reconstitute quasi-native Trp1p only when fused to interacting proteins.
[0007] As used herein, a “reporter protein” is understood as a protein or peptide, which possesses a unique activity in vivo and/or in vitro, and which produces a signal that allows the active protein to be easily discernable even within a complex mixture of other proteins or peptides, especially in vivo. Reporter proteins as understood herein are e.g. (i) proteins which are essentially involved in the biosynthetic pathway of formation of an amino acid or an other essential metabolite that is crucial for the organism to survive on medium lacking the respective amino acid or metabolite; or (ii) proteins which are detectable by a characteristic color assay when, preferably in vivo; etc.
[0008] As used herein, a “suitable fragmentation site” is understood as an especially randomly chosen position in the amino acid chain (and/or the corresponding gene sequence, respectively), at which a given reporter protein is fragmented into a first subdomain and a complementary second subdomain (and/or the corresponding first subsequence and the complementary second subsequence, respectively), wherein the fragmentation site is suitable in the sense of the present invention, when it fulfils the following demands: (i) to yield two fragments that efficiently fold into quasi-native protein only when fused to two interacting proteins; (ii) not to significantly impair the activity of a reconstituted protein by bringing the two fragments into close proximity especially in vivo; (iii) to yield soluble protein fragments that are not readily degraded in vivo.
[0009] As used herein, the term “detectable”, especially “detectable when active” is understood as follows. Detection in the sense of the present invention includes any direct or indirect method of testing for the presence of a reporter protein, especially when reconstituted by fragments thereof, e.g. by chemical, physical, or visual means. Most preferably, detection is performed by a color assay, e.g. fluorescence, chemiluminescence or the like, (in vivo and/or in vitro) and/or a growth assay (in vivo)
[0010] As used herein, a “first subdomain” and a “complementary second subdomain” of a reporter protein are understood as follows. A first subdomain represents a first successional part (either an N-terminal-, C-terminal-, integral part or even a part involving both the N-terminal- and the C-terminal part) of a native reporter protein. A complementary second subdomain represents a complementary second part (either an N-terminal, C-terminal, integral part or even a part involving both the N-terminal- and the C-terminal part). The first subdomain and the complementary second subdomain essentially resemble the wild-type sequence, when viewed together, wherein overlapping sequences between both subdomains, that are present in both the first subdomain and the complementary second subdomain can be tolerated as long as the activity of the enzyme is not significantly negatively affected. Moreover, minor deletions, additions or other alterations to the overall sequence can be tolerated, especially at the N-terminus or the C-terminus, as long as the activity of the reporter protein, either as a whole or when reconstituted by its fragments, is not significantly negatively affected.
[0011] As used herein, a “first subsequence” and a “complementary second subsequence” are understood as gene sequences encoding for the above-mentioned first subdomain and complementary second subdomain.
[0012] As used herein, a “color assay” is understood as a manually or device-supported detection of a change in optical appearance of a sample comprising the reporter protein, or a reporter protein reconstituted by its fragments, inc1. color developments as well in the visible as in the invisible spectrum. Color assays are especially preferred, that can be qualitatively detected by the unaided eye e.g. by coloration of living cells in vivo (colonies on a plate or the like), and that can be additionally quantified in an in vitro assay, e.g. for determining the intensity of an interaction between two proteins.
[0013] As used herein, a “growth assay” is understood as an assay, that allows for the growth of a cell, e.g. a colony on a plate, when the reporter protein is present or actively resembled by its fragments, and wherein cells fail to grow, when the reporter protein is not present or actively resembled by its fragments. Most preferably, the growth assay suchlike allows for a simple visual selection of positives.
[0014] As used herein, “stringent conditions” for hybridization of DNA are understood as follows. Given a specific DNA sequence, a person of skill in the art would not expect substantial variation among species within the claimed genus due to hybridization under such conditions, thus expecting structurally similar DNA.
[0015] The method according to the invention for the identification of suitable fragmentation sites in a reporter protein, wherein the reporter protein is detectable when active, comprises the steps of:
(a) providing a DNA sequence encoding for said reporter protein; (b) creating a library based on the DNA sequence as defined in (a),
wherein each individual of said library comprises a randomly created first subsequence of the DNA sequence as defined in (a), encoding for a first subdomain of said reporter protein, and wherein each individual of said library comprises a randomly created complementary second subsequence of the DNA sequence as defined in (a), encoding for a complementary second subdomain of said reporter protein;
(c) screening and/or selection for restoration of detectable activity of said reporter protein, when said first subdomain and said complementary second subdomain are brought into close proximity; (d) identifying said first subdomain and/or said first subsequence, and said complementary second subdomain and/or said complementary second subsequence, that lead to restoration of detectable activity of said reporter protein.
[0022] By using a combinatorial library approach, comprising randomly created first subsequences and randomly created complementary second subsequences, the drawbacks of rational design of split-protein sensors are overcome. Most advantageously, even fragmentation sites of proteins encoded by said subsequences may thereby be identified, which would have never been readily predicted by any rational approach. First subsequences and complementary subsequences are ideally suitable in the context of the present invention, when reconstitution of activity of the corresponding reporter protein only occurs to a significant extent at all, when both corresponding subdomains are forced into close spatial proximity, but do not self-assemble in order to reconstitute a detectable amount of an active reporter protein.
[0023] DNA sequences of suitable reporter proteins are readily available to the person of routine skill in the art (step (a)), e.g. from the National Center for Biotechnology Information (NCBI), National Library of Medicine, Building 38A, Bethesda, Md. 20894. Genes encoding for reporter proteins may then be amplified e.g. from a suitable host cell by PCR using standard techniques and primers suitably designed based on the known DNA sequence (vide supra), or the gene encoding for a reporter protein may be completely built up from suitably designed oligonucleotides de novo.
[0024] DNA manipulating techniques that may be used in step (b) for the creation of a library based on said DNA sequence are readily apparent to the person of routine skill in the art, either. In short, N- and C-terminal domains of the wild-type reporter protein are amplified separately from a suitable source of DNA by standard PCR techniques, and are subsequently recombined using standard overlap extension PCR techniques in order to recombine and thereby re-arrange the wild-type gene, preferably now containing the N- and C-termini of the wild-type gene connected with each other and as an internal part of the sequence, and preferably comprising a unique restriction site at the wild-type N- and C-termini. At the same time, suitable restriction sites may be designed at the newly created N- and C-termini in order to allow for efficient subsequent cloning steps; most preferably, the restriction site is designed for the same restriction enzyme at both the N- and C-terminus. Most preferably, the rearranged DNA construct is inserted into a high-copy plasmid, the plasmid amplified by standard techniques, and the re-arranged DNA of interest is thereafter cut out of the high-copy plasmid using the restriction sites at the newly created N- and C-termini. The rearranged gene is then incubated with a ligase to yield dimerized, oligomerized and circularized DNA construct. Afterwards, these constructs are digested e.g. with a suitable, random-cut DNAse, and fragments corresponding to the wild-type length are preferably thereafter treated with ligase and polymerase to repair nicks, gaps and to flush the ends of the fragments of the reporter protein. Afterwards, the DNA fragments corresponding to the wild-type length of the reporter protein's gene are isolated e.g. by standard agarose gel electrophoresis procedures. The resulting fragments are preferably blunt-end cloned into a suitable expression vector, which was cleaved at a unique restriction site (preferably blunt-end). The expression vector is especially designed by standard DNA manipulation techniques to provide a construct after blunt-end cloning, in which one of the artificially generated new N- and C-termini is under the control of a promoter sequence and especially fused to a gene encoding for a tag sequence and a gene encoding for first peptide or protein C1, each preferably via a linker sequence. Moreover, the other terminus, respectively, is especially fused to a gene encoding for a preferably different tag sequence and gene encoding for a second peptide or protein C2. Peptides or proteins C1 and C2 are thereby known to interact with each other in vivo, and may e.g. be leucine zippers. The tag sequences may afterwards advantageously be used for the control of correct expression and stability of fusion proteins. After transformation and amplification in a suitable host such as e.g. E. coli XL1Blue to a typical library size of about 10 4 to 10 5 independent clones, the vector is linearized at a restriction site at the wild-type N- and C-termini, and an oligonucleotide is inserted into the resulting gap, which is specifically designed to integrate a terminator for the first domain of said reporter protein and a promoter sequence for the second domain of said reporter protein, by homologous recombination in a suitable host such as yeast according to standard procedures. The oligonucleotide is designed and constructed by standard PCR techniques to provide flanking regions both at the 5′ and 3′ ends of e.g. about 50 bp with the gene of the reporter protein in order to allow for successful homologous recombination. Suchlike, the selection of clones possessing fragmentation sites at or nearby the wild-type N- and C-termini can be suppressed. For selecting thereafter, a marker gene is also provided by the oligonucleotide, e.g. encoding for a protein involved in antibiotic resistance. Successful homologous recombination may thus be easily observed by growth in the presence of the respective antibiotic.
[0025] Step (c) is preferably carried out by growing the respective transformants of the library on medium which e.g. lacks a nutrient, e.g. an amino acid, or which provides a substrate for a color reaction. Thus, preferably a growth assay or a color assay is performed, thereby allowing for easy selection of those transformants which lead to a restoration of activity of the reporter protein, which is e.g. essentially involved in the synthesis of said nutrient, e.g. said amino acid, or in said color reaction. Step (c) especially involves the elimination of false positives, i.e. first subdomains and complementary second subdomains, that reconstitute an active reporter enzyme by self-reassembling, i.e. without the need of an outer influence forcing the two domains into close spatial proximity. This can be done e.g. by fusing the respective first and second subdomains of the reporter protein to first and second peptides or proteins, that do not interact with each other, and/or by testing the respective first and second subdomains without any first and second peptides fused thereto at all, and/or by testing constructs lacking the first or the second subdomain, respectively. These assays can be performed by techniques commonly known in the art of e.g. two-hybrid assays.
[0026] Identification of suitable subdomains and subsequences, i.e. suitable fragementation sites, can be performed by common DNA-and/or protein sequencing techniques.
[0027] According to a preferred embodiment, the reporter protein is detectable in vivo and/or in vitro, both as full length protein and when actively resembled by a first subdomain and a complementary second subdomain, by a means chosen from the group consisting of color assays and growth assays.
[0028] Growth assays provide the advantage of a selection step, i.e. only positives grow under the chosen conditions, thus eliminating the need of further screening all individuals of the library. Exemplarily, only positives that comprise a suitable combination of first subdomain and complementary second subdomain grow as colonies on nutrition-specific plates. Color assays, moreover, can be individually designed depending on the specific reporter protein, when this reporter protein is involved naturally in or artificially usable for a color-developing reaction. In some cases, a substrate for such a reporter protein may be incorporated into the growth medium, e.g. the plate, whereupon colored colonies appear due to reconstitution of an active reporter protein by a first subdomain and a complementary second subdomain in vivo. Quanification of such an in vivo color assay may be optionally performed with samples obtained from such colonies. The general procedure of growth assays, color assays and subsequent quantification of the color assay are known in principle from the classical two-hybrid system, cf. eg. U.S. Pat. No. 5,667,973, incorporated herein by reference.
[0029] In an especially preferred embodiment, individuals of the library as defined in (b) are either prokaryotic or eukaryotic host cells, comprising:
both said first subsequence and said complementary second subsequence in one and the same expression vector, suitable for (co-)expression of said first subsequence and said complementary second subsequence in vivo; or said first subsequence in a first expression vector suitable for (co-)expression of said first subsequence, and said complementary second subsequence in a second expression vector suitable for (co-)expression of said complementary second subsequence.
[0032] In vivo assays are at least in the first step preferred, e.g. as a growth assay as outlined above. Thus, prokaryotic or eukaryotic host cells are provided, that are manipulated suchlike to allow for the (co-)expression of both the first and the complementary second subdomain of the reporter protein. Depending on the specific application, both subdomains may of course be encoded by one and the same, or by separate vectors. In most cases, encoding by one and the same vector will be favourable. A vast amount of suitable expression vectors for use as a basis in this respect are available to the person of routine skill in the art, e.g. the pRS316-based yeast expression vector (cf. Sikorski, R. S., and Hieter, P. (1989), Genetics 122, 19-27, incorporated herein by reference).
[0033] It is especially preferred that the screening for restoration of detectable activity of said reporter protein, when said first subdomain and said complementary second subdomain are brought into close proximity as defined in (c), comprises the following steps:
creating a first fusion subsequence comprising the first subsequence of said reporter protein as defined in (b), fused to an oligonucleotide encoding for a first protein or peptide, creating a second fusion subsequence comprising the complementary second subsequence of said reporter protein as defined in (b), fused to an oligonucleotide encoding for a second protein or peptide,
wherein said first protein or peptide and said second protein or peptide are known to interact.
[0036] By creating said first fusion sequence and said second fusion subsequence, the first subdomain and the complementary second subdomain are forced into close spatial proximity, thus allowing for a screening for restoration of activity of the reporter protein, when the subdomains are forced into close proximity. Preferably, said first protein or peptide and said second protein or peptide are chosen to be robust and relatively small proteins or peptides; especially preferred in the context of the invention are leucine zippers, most preferably leucine zippers which associate to an anti-parallel coiled coil (interacting proteins fused to 3′-terminus of the first subdomain and the 5′-terminus of the second subdomain, or vice versa, respectively). However, for specific embodiments, a parallel orientation may be preferred, e.g. for testing membrane proteins which most commonly exhibit both the N- and the C-terminus to one and the same site.
[0037] According to a further embodiment said first fusion subsequence and said second subsequence are created by blunt end ligation.
[0038] Blunt end ligation is the method of choice for the construction of said fusion subsequences, as due to the evolutionary, random approach of library generation no predictable, specific sticky-end ligation can be performed. Although blunt-end ligation leads to the creation of statistical amounts of ligation products which are out of the reading frame, this approach still proved sufficiently efficient for the identification of suitable fragmentation sites according to the invention.
[0039] Moreover, in another especially preferred embodiment said first fusion subsequence and said second fusion subsequence each comprise
a linker sequence in between said first subsequence (or said second subsequence, respectively) and said oligonucleotide encoding for a first protein or peptide (or said oligonucleotide encoding for a second protein or peptide, respectively); at least one tag that allows for verification of the transcription of said first fusion subsequence and said second fusion subsequence.
[0042] Linker sequences commonly prove useful in the art of construction of fusion proteins in order to both allow for proper folding of both components of the fusion protein individually or cooperatively, and/or to achieve sufficient spatial integrity of both components of the fusion protein.
[0043] The use of tag sequences that allow for the detection of transcription of a gene sequence is also routinely applied in the art. In the context of the present invention, tag sequences may be applied to any of the N- and C-terminus of the first subdomain and/or the N- and C-terminus of the complementary second subdomain. It is especially preferred to provide differently recognizable tag sequences both at the N- and the C-termini of each transcription product. Cornmonly applied tags are e.g. the HA tag, the flag tag or the like. Detection of correct expression of these tags, and thereby of the fusion protein(s), may be performed e.g. by Western-blotting according to routine procedures.
[0044] According to an especially preferred embodiment, an oligonucleotide is inserted by homologous recombination in between said first subsequence and said second subsequence, encoding for:
a transcription terminating sequence for terminating transcription of said first or said second subsequence; a transcription promoting sequence for initiating transcription of said second or said first subsequence, respectively; a marker sequence allowing for control of successful homologous recombination.
[0048] An especially advantageous way of carrying out the present invention is to simply initially provide said first and said second subsequence continuously, preferably rearranged, and thereafter to separate them by introducing a transcription terminating sequence succeeding the first subsequence, and a transcription promoting sequence preceeding the second subsequence. Thereby, separate expression is secured of both the first subdomain and the complementary second subdomain, or their fusion domains, respectively. This goal may be especially advantageously achieved by homologous recombination at a predefined site in between said first and said second subsequence (c.f. Oldenburg, K. R., Vo, K. T., Michaelis, S., and Paddon, C. (1997), Nucleic Acids Res 25, 451-452, incorporated herein by reference).
[0049] In order to eliminate the otherwise high risk of isolating subdomains, that are fragmented at fragmentation sites nearby the N- and C-termini of the wild-type reporter protein, it is especially preferred to not provide the DNA sequence of said reporter protein according to step (a), vide supra, in its wild-type configuration, but rather already with the wild-type N- and C-termini connected with each other and being an internal part of the DNA sequence of said DNA sequence. Thereby, artificial new N- and C-termini are created in the starting material. Most preferably, a unique restriction site RE2 is introduced in between the wild-type N- and C-terminus. A further restriction site RE1 is advantageously introduced at the new artificial N- and C-terminus of the DNA sequence of said reporter protein according to step (a), allowing for easy and convenient cloning and construction of libraries according to step (b), vide supra. Due to the unique restriction site RE2, homologous recombination in a suitable host cell can be performed in between the wild-type N- and C-terminus of the reporter protein. Due to the necessary overlap for successful homologous recombination, isolation of subdomains with fragmentation sites at or nearby the wild-type N- and C-terminus is suppressed. Most preferably, the oligonucleotide used for homologous recombination comprises a selection marker such as e.g a gene involved in antibiotic resistance in order to check for successful homologous recombination.
[0050] Thus, in a further embodiment, the method comprises the steps of:
creating fragmentation sites in TRP1 using gene cleavage with a unique restriction enzyme RE1 and circularization; isolating fragments corresponding to the wild-type length; subcloning using blunt ends preferably into a pRS316 based yeast expression vector under the control of a copper promoter (pCUB1) and transforming into E. coli , preferably XL1Blue; recombining and amplifying homologues with a unique restriction site RE2, preferably AvrII, introduced between the original N- and C-termini to allow subsequent linerization of the vector; locating two leucine zippers in the plasmid at the 3′- and the 5′-ends of the newly generated N- and C-termini, the zippers being positive and negative charged helices to allow heterodimerization, preferably each heterodimer containing a buried asparagine residue in a position to force antiparallel orientation of the zippers.
[0056] The invention further relates to a recombinant DNA sequence for use in securing expression in a prokaryotic or eukaryotic host cell of a polypeptide product having the primary structural conformation of a first subdomain of a reporter protein or a complementary second subdomain of a reporter protein, wherein detectable activity of said reporter protein is restored, when said first subdomain and said complementary second subdomain are brought into close proximity, and wherein said first and said complementary second subdomain are not subdomains of one of the group of proteins consisting of transcriptional activators, ubiquitin, dihydrofolate reductase, β-lactamase, green fluorescent protein and closely related variants such as e.g. ECFP, EGFP or the like, β-galactosidase, inteins, cAMP cyclase, glycinamide ribonucleotide transformylase, aminoglycoside
[0057] In the above-mentioned and herewith disclaimed DNA sequences, suitable fragmentation sites for split-protein sensors were already identified by rational design (cf. e.g. Methods Enzymology 238, Michnick et al. 2000). However, the present invention now opens up for the first time the possibility to identify suitable fragmentation sites in any other DNA sequence encoding for a reporter protein by a random library approach, too. Providing this tool to the person of routine skill in the art by the method disclosed herein, suitable fragmentation sites may be now identified with relative ease.
[0058] In especially preferred embodiments, said DNA sequence encodes for a subdomain of a (β/α) 8 -barrel enzyme, such as e.g. Trp1p.
[0059] In further embodiments, which proved especially advantageous, said DNA sequence is selected from the group consisting of:
(a) the DNA sequences set out in Table 1 and their complementary strands; (b) DNA sequences which hybridize under stringent conditions to the protein coding regions of the DNA sequences defined in (a) or fragments thereof; (c) DNA sequences which, but for the degeneracy of the genetic code, would hybridize to the DNA sequences defined in (a) or (b) and which sequences code for a polypeptide having the same amino acid sequence.
[0063] The above-mentioned DNA sequences encode for the split-Trp sensors split-Trp 44 (i.e. 44 N trp and 44 C trp ), split-Trp 53 (i.e. 53 N trp and 53 C trp ), split-Trp 187 (i.e. 187 N trp and 187 C trp ), split-Trp 204b (i.e. 204b N trp and 204b C trp ), which proved to be valuable tools as split-protein sensors (numbering according to the fragmentation site, given as the last amino acid of the N-terminal subdomain). Especially split-Trp44 was successfully applied herein to demonstrate the interaction of membrane proteins.
[0064] The DNA- and amino acid sequences of the above-mentioned split-Trp sensors are given in the attached sequenced listing as follows:
SEQ ID NO: 3 44 N trp (DNA sequence); SEQ ID NO: 4 44 N trp (amino acid sequence); SEQ ID NO: 5 44 C trp (DNA sequence); SEQ ID NO: 6 44 C trp (amino acid sequence); SEQ ID NO: 7 53 N trp (DNA sequence); SEQ ID NO: 8 53 N trp (amino acid sequence); SEQ ID NO: 9 53 C trp (DNA sequence); SEQ ID NO: 10 53 C trp (amino acid sequence); SEQ ID NO: 11 187 N trp (DNA sequence); SEQ ID NO: 12 187 N trp (amino acid sequence); SEQ ID NO: 13 187 C trp (DNA sequence); SEQ ID NO: 14 187 C trp (amino acid sequence); SEQ ID NO: 15 204b N trp (DNA sequence); SEQ ID NO: 16 204b N trp (amino acid sequence); SEQ ID NO: 17 204b C trp (DNA sequence); SEQ ID NO: 18 204b C trp (amino acid sequence);
[0081] In preferred embodiments according to the present invention, said DNA sequences are used in securing expression in a prokaryotic or eukaryotic host cell of a polypeptide fusion product. Such securing of expression may be achieved by any means routinely applied by the person of routine skill in the art, comprising e.g. incorporation of said DNA sequences into suitable expression vectors or integration of said DNA sequences into the genome of said host.
[0082] The invention further relates to a first subdomain of a reporter protein or a complementary second subdomain of a reporter protein, wherein detectable activity of said reporter protein is restored, when said first subdomain and said complementary second subdomain are brought into close proximity, and wherein said first and said complementary second subdomain are not subdomains of one of the group of proteins consisting of transcriptional activators, ubiquitin, dihydrofolate reductase, β-lactamase, green fluorescent protein and closely related variants such as e.g. ECFP, EGFP or the like, β-galactosidase, inteins, cAMP cyclase, glycinamide ribonucleotide transformylase, aminoglycoside phosphotransferase, hygromycin B phosphotransferase, luciferase.
[0083] In the above-mentioned and herewith disclaimed proteins, suitable fragmentation sites for split-protein sensors were already identified by rational design. However, the present invention now opens up for the first time the possibility to identify suitable fragmentation sites in any other reporter protein by a random library approach, too. Providing this tool to the person of routine skill in the art by the method disclosed herein, suitable fragmentation sites may be now identified with relative ease.
[0084] According to especially preferred embodiments of the invention, a first subdomain of a reporter protein or a complementary second subdomain of a reporter protein are produced by a method of culturing a host transformed with a recombinant DNA sequence as outlined above, wherein said molecules further comprises an expression control sequence, said expression control sequence being operatively linked to said molecule. Said expression control sequences comprise especially those which are commonly referred to as tags which are recognizable e.g. by Western-blotting procedures routinely applied in the art.
[0085] The invention further relates to a fusion protein comprising a first subdomain of a reporter protein or a complementary second subdomain of a reporter protein as outlined above, and a further peptide or protein connected thereto in a naturally not occurring combination. By creating such artificial fusion proteins, said further protein of peptide may then be tested for interaction with e.g. a specifically chosen counterpart or against a library of possible counterparts. Moreover, library-library screening assays may also be applied, e.g. genome-wide library screenings as e.g. already performed in the art of traditional two-hybrid assay.
[0086] The invention further relates to a prokaryotic or eukaryotic host cell line, transformed with recombinant DNA sequences as outlined above.
[0087] Said prokaryotic or eukaryotic host cell lines are preferably E. coli or yeast strains. For cloning and storage purposes, mostly E. coli strains such as XL1Blue will be chosen. For the method of identification of suitable fragmentation sites according to the invention, especially involving the step of homologous recombination, a yeast strain may be chosen such as e.g. Saccharomyces cerevisiae , e.g. EGY48, and Schizosaccharomyces pombe . The choice of a suitable host cell line is routinely performed by the person of skill in the art, depending on the specific purpose; such host cell lines are commonly available.
[0088] The invention is further related to a kit of parts, comprising a first and a second DNA-based expression vector, wherein
said first expression vector contains an expression cassette encoding for a polypeptide product having at least a substantial part of the primary structural confirmation of a first subdomain of a reporter protein; and said second expression vector contains an expression cassette encoding for a polypeptide product having at least a substantial part of the primary structural confirmation of a complementary second subdomain of a reporter protein; and wherein detectable activity of said reporter protein is restored, when said first subdomain and said complementary second subdomain are brought into close proximity, and wherein said first and said complementary second subdomain are not subdomains of one the group of proteins consisting of transcriptional activators, ubiquitin, dihydrofolate reductase, β-lactamase, green fluorescent protein and closely related variants such as e.g. ECFP, EGFP or the like, β-galactosidase, inteins, cAMP cyclase, glycinamide ribonucleotide transformylase, aminoglycoside phosphotransferase, hygromycin B phosphotransferase, luciferase.
[0091] According to a further especially preferred embodiment, such a kit of parts further comprising a suitable prokaryotic or eukaryotic host cell line for expression of said first and second expression vector.
[0092] Having provided by the present invention a tool for identifying novel fragmentation sites in reporter proteins, another major aspect of the present invention is related to a method for detecting an interaction between a first test peptide or protein or a fragment thereof, and a second test peptide or protein or a fragment thereof, the method comprising the steps of:
providing recombinant DNA sequences as outlined above for use in securing expression of a first subdomain of a reporter protein and a complementary second subdomain of a reporter protein; fusing an oligonucleotide or a gene encoding for a first test peptide or protein to the DNA sequence encoding for said first subdomain of the reporter protein, thereby creating a first DNA fusion sequence encoding for a fusion protein comprising said first subdomain of the reporter protein and said first test peptide or protein; fusing an oligonucleotide or a gene encoding for a second test peptide or protein to the DNA sequence encoding for said complementary second subdomain of the reporter protein, thereby creating a second DNA fusion sequence encoding for a fusion protein comprising said complementary second subdomain of the reporter protein and said second test peptide or protein; (co-)expressing said fusion protein comprising said first subdomain of the reporter protein and said first test peptide or protein, and said fusion protein comprising said second complementary subdomain of the reporter protein and said second test peptide or protein in a suitable prokaryotic or eukaryotic host cell; screening and/or selecting for restoration of detectable activity of said reporter protein.
[0098] Utilizing split-protein sensors with subdomains identified by a method according to the invention, interaction of said first test peptide and said second test peptide may be identified. Given the tool of identifying suitable fragmentation sites in virtually any reporter protein, the person of routine skill in the art is no more hampered by the limitations of the existing, rationally designed split-protein systems to specific cellular compartments, but rather may now choose a reporter protein depending on his specific test purpose.
[0099] In the most preferred embodiment, a library of oligonucleotides or DNA encoding for a set of first test peptides or proteins and/or a library of oligonucleotides or DNA encoding for a set of second test peptides or proteins are fused to said first subdomain of said reporter protein and/or said complementary second subdomain of said reporter protein, respectively.
[0100] According to an especially preferred embodiment of the present invention, the interaction between a first test peptide or protein or a fragment thereof and a second test peptide or protein or fragment thereof is mediated by a chemical inducer of dimerization, which binds either covalently or non-covalently to both said test peptides or proteins or fragments thereof.
[0101] Comparable systems are commonly referred to in the literature as three-hybrid systems. Chemical inducers of dimerization (CIDs) have been first described by Schreiber and Crabtree (c.f. Spencer D. M, Wandless T. J, Schreiber S. L, and Crabtree G. R (1993), Science 262, 1019-1024, incorporated herein by reference). CIDs are cell-permeable molecules that can simultaneously form a covalent- or non-covalent interaction with two different proteins or peptides, thereby inducing their dimerization. Using split-protein sensors according to the present invention, e.g. robust drug and/or drug target screening assays may easily be established. Towards this aim, e.g. N trp may be fused to a protein library and C trp to an O(6)-alkylguanine-DNA alkyltransferase (AGT), e.g. human AGT (hAGT). A substrate for hAGT, e.g. Benzylguanine, may be easily covalently linked to a multitude of small molecules (hypothetical drugs), thus allowing for an efficient screening for cellular targets contained in said protein library that react or associate with the corresponding drug.
[0102] Moreover, the invention is related to a method for detecting the interruption of an interaction between a first test peptide or protein or a fragment thereof, and a second test peptide or protein or a fragment thereof, the method comprising the steps of:
providing recombinant DNA sequences according to one of claims 11 to 14 for use in securing expression of a first subdomain of a reporter protein and a complementary second subdomain of a reporter protein; fusing an oligonucleotide or a gene encoding for a first test peptide or protein to the DNA sequence encoding for said first subdomain of the reporter protein, thereby creating a first DNA fusion sequence encoding for a fusion protein comprising said first subdomain of the reporter protein and said first test peptide or protein; fusing an oligonucleotide or a gene encoding for a second test peptide or protein to the DNA sequence encoding for said complementary second subdomain of the reporter protein, thereby creating a second DNA fusion sequence encoding for a fusion protein comprising said complementary second subdomain of the reporter protein and said second test peptide or protein; (co-)expressing said fusion protein comprising said first subdomain of the reporter protein and said first test peptide or protein, and said fusion protein comprising said second complementary subdomain of the reporter protein and said second test peptide or protein in a suitable prokaryotic or eukaryotic host cell; screening and/or selecting for interruption of interaction of said first subdomain and said second subdomain under the influence of one or more test agents.
[0108] Comparable systems are commonly referred to in the literature as reverse two-hybrid systems (or split-protein systems, respectively). Exemplarily, 5-fluoroanthranilic acid (FAA) is metabolized in vivo into a toxic product by the tryptophan biosynthetic enzymes. Applying the split-Trp sensors according to the invention, the disruption of protein-protein interaction leading to the spatial separation of the Trp1p fragments (and thus inactivity of the reporter protein) can therefore be linked to the survival of the cells on medium containing FAA. By means of example, libraries of small molecules may be screened for their ability to interact with a pair of fusion proteins. Selection of proteins or peptides that disrupt an interaction can be done by co-expressing two interacting proteins with a random protein or peptide library e.g. on plates containing FAA. The reverse split-Trp sensors may also advantageously be used to determine the binding region of a protein. A random library of the protein carrying mutations is co-expressed with its binding partner on plates containing FAA. Only cells that express a library member with mutations in or affecting the binding region, thus disrupting the interaction of the two proteins, will be able to grow in the presence of FAA.
[0109] Another aspect of the present invention is related to a use of random circular permutation of a gene and/or the expressed polypeptide derived thereof for the identification of fragmentation sites in a reporter protein for use in a split-protein sensor. To date, random circular permutation has not been used for the identification of such suitable fragmentation sites for separately expressed subdomains, but rather for the identification of proteins of at least approximately wild-type length, but with artificially new N- and C-termini, and with the wild-type N- and C-termini being connected to each other and being an internal part of the sequence. However, this approach now surprisingly proved to be an outstandingly valuable tool for the evolutionary, combinatorial approach of identifying suitable fragmentation sites for subdomains to be expressed separately.
[0110] A further aspect of the present invention is related to a use of a host cell line that allows for homologous recombination of DNA for the generation of a recombinant DNA molecule that secures for expression of both a polypeptide product comprising a first subdomain of a reporter protein and a complementary second subdomain of a reporter protein from said recombinant DNA molecule.
[0111] To date, homologous recombination has not been used for this purpose, but has now surprisingly found to be an outstandingly valuable tool for simply and conveniently securing for expression of a first subdomain and a complementary second subdomain of a reporter protein.
DETAILED DESCRIPTION OF THE INVENTION
[0112] The invention will now be described in even more detail by means of an example and a specific embodiment, together with the accompanying figures; however, without the invention being limited thereto.
[0113] FIG. 1 : Combinatorial approach towards the generation of split-Trp sensors. As a starting point, a rearranged copy of the TRP1 gene was used in which the original N- and C-termini of TRP1 were connected by a short linker encoding a unique restriction site RE2, here an AvrII site. For convenient subcloning, another restriction site RE1 was introduced at the artificially created new N- and C-termini, here a HindIII site. The linear fragment was incubated with T4 DNA ligase to circularize/oligomerize the gene (step 1). Treatment of the ligation mix with DNAseI resulted in randomly cut linear molecules and fragments corresponding to the size of TRP1 were isolated (step 2). Isolated fragments were cloned into a yeast expression vector containing two polypeptides (C1 and C2) that associate into an antiparallel-coiled coil (step 3). Homologous recombination in yeast cells was used to insert a terminator sequence and the P GAL1 -promoter between the original N- and C-termini (step 4). Co-expression of the two fragments and selection for complementation of tryptophan auxotrophy of yeast cells allowed the isolation of functional split-Trp pairs.
[0114] FIG. 2 : Selected split-Trp protein pairs capable of complementing tryptophan auxotrophy in yeast. The clones are named after the last residue of each N-terminal fragment. C1 and C2 are the two polypeptides that associate into the anti-parallel coiled coil. Due to a shift in the reading frame in 5 of the twelve clones, C2 is replaced by peptide of 10 or 66 amino acids, and C1 is replaced in one clone by a peptide of 26 residues. Five of the twelve analyzed clones lead to the expression of Trp1p fragments in which both fragments were fused in frame to the polypeptides C1 and C2 (marked with an asterisk).
[0115] FIG. 3 : Characterization of the selected split-Trp pairs that are marked with an asterisk in FIG. 2 . Growth assays of yeast strains expressing split-Trp 44 , split-Trp 53 , split-Trp 187 , split-Trp 204b or split-Trp 77 on selective plates (+/Δ trp: plates with tryptophan/lacking tryptophan, respectively; +/Δ gal: plates with galactose/lacking galactose). For control experiments, yeast strains expressing the split-Trp proteins in which the sequence encoding for C2 was deleted form the plasmid (split-Trp-ΔC2) were also investigated. One colony of yeast cells EGY48 expressing different split-Trp protein pairs was resuspended in 1 ml water and 5 μl were spotted on medium with or without tryptophan and/or galactose, but always containing copper at two different temperatures (30° C. and 23° C.). C1-C trp is under control of the leaky P CUP1 -promoter and N trp -C2 under the control of the P GAL1 -promoter. Images were taken after 8 days.
[0116] FIG. 4 : Analysis of the interaction between Sec62p and Sec63p using the split-Trp system. Left: N trp is fused to the N terminus of Sec62p and C trp is fused to the C terminus of Sec63p, resulting in N trp -Sec62p and Sec63p-C trp , respectively. The linker between the cytosolic domains of Sec62p and Sec63p and the corresponding Trp1p fragments consists of six residues. The known interaction between the positively charged cytosolic N-terminal domain of Sec62p and the negatively charged C-terminal tail of Sec63p should lead to the reconstitution of active Trp1p and complementation of tryptophan auxotrophy. Right: Co-expression of N trp -Sec62p with Ste14p-C trp , a further membrane protein of the ER, which does not interact with Sec62p, should not lead to the formation of a functional Trp1p and the complementation of tryptophan auxotrophy.
[0117] FIG. 5 : Split-Trp interaction assay of Sec62p and Sec63p. A colony of EGY48 cells co-expressing N tpr -Sec62p with Sec63p-C trp or Ste14p-C trp was suspended in 1 ml water and 5 μl were spotted on copper containing medium with or without tryptophan. Cells co-expressing 44 N trp -Sec62p/Sec63p- 44 C trp complement tryptophan auxotrophy as indicated by their growth after 4 days at 23° C. Large colonies were visible after 7 days of incubation, whereas only small colonies were observed for cells expressing 187 N trp -Sec62p/Sec63p- 187 C trp . No or only very small colonies were observed for cells co-expressing 53 N trp -Sec62p/Sec63p- 53 C trp or 204b N trp -Sec62p/Sec63p- 204b C trp , respectively. No growth was observed for cells co-expressing 44 N trp -Sec62p/Ste14p- 44 C trp or 187 N trp -Sec62p/Ste14p- 187 C trp even after 10 days of incubation at 23° C.
[0118] DNA- and protein sequences SEQ ID NO: 1 to SEQ ID NO: 66, as given in the attached sequence listing, are given in the attached sequence listing, incl. all primers and oligonucleotides used for the construction of the vectors.
[0119] For any standard molecular biology and especially DNA- and protein manipulation protocols it is generally referred to Sambrook, J. et al., eds., M OLECULAR C LONING , A L ABORATORY M ANUAL, 2nd. edition, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y. (1989); Ausubel, F. et al., eds., C URRENT P ROTOCOLS IN M OLECULAR B IOLOGY , John H. Wiley & Sons, Inc. (1997); HYBRID HUNTER™ INSTRUCTION MANUAL, Invitrogen BV, Groningen, Neherlands (1999); Burke, D et al., METHODS IN YEAST GENETICS. A COLD SPRING HARBOR LABORATORY COURSE MANUAL, Cold Spring Harbor Laboratory Press (2000).
[0120] Yeast Media. Yeast complete medium containing adenine (YPAD) was used for cultures of Saccharomyces cerevisiae EGY48 and RSY529. Dropout media (YC) were used to select for the presence of pRS315- or pRS316-derived plasmids and for the complementation of tryptophan auxotrophy. Lacking amino acids or components in the resulting medium are indicated by the addition of their one-letter code to the YC-dropout medium. Selective YC-medium used to plate out the yeast cells after transformation by electroporation was supplemented with 1 M sorbitol. For the expression of proteins from the P GAL1 -promoter 2% galactose and 0.5% raffinose replaced glucose as carbon source in the YC-medium.
YPAD: 1% yeast extract, 2% peptone, 2% dextrose, 100 mg/l adenine, (2% agar for plates) YC 0.12% yeast nitrogen base, 0.5% ammonium sulfate, 1% succinic acid, 2% glucose, 0.6% NaOH, 1.4 g/l yeast synthetic dropout medium omitting histidine (H), leucine (L), tryptophan (W) and uracil (U), (2% agar for plates), L: 0.05 g/l histidine (H), 0.1 g/l tryptophan (W), 0.1 g/l uracil (U) U: 0.05 g/l histidine (H), 0.1 g/l leucine (L), 0.1 g/l tryptophan (W) LU: 0.05 g/l histidine (H), 0.1 g/l tryptophan (W) LUW: 0.05 g/l histidine (H)
[0127] Transformation of yeast cells. The transformation of Saccharomyces cerevisiae strains EGY48 or RSY529 with one or more plasmids was done using a standard protocol for transformation by electroporation. An overnight culture of EGY48 or RSY529 yeast cells in YPAD medium was diluted in 500 ml YPAD to an OD 600 of ˜0.3 and grown at 30° C. and 260 rpm to an OD 600 of ˜1.4. The culture was harvested by centrifugation at 4300 rpm and washed with 500 ml and 250 ml ice-cold sterile water and with 30 ml ice-cold 1 M sorbitol. The pelleted cells were then resuspended in 300-500 μl 1 M sorbitol and either used directly for transformation or frozen in aliquots of 40 μl at ˜80° C. For the double transformation of two plasmids, competent cells were always prepared freshly. A total amount of 100 ng plasmid DNA was mixed with 40 μl competent yeast cells, and electroporated at 1.5 kV using a Stratagene electroporator 1000 in a 0.2 mm cuvette. The cells were mixed with 500 μl ice-cold 1 M sorbitol immediately after the pulse and plated on the corresponding solid selective YC-medium containing 1 M sorbitol.
[0128] Cloning of pRS316-C1/2 CUP1 . A sequence containing two polypeptides C1 and C2 was first assembled by PCR using a set of primers as described by Stemmer et al (cf. Oakley M. G., and Kim P. S. (1998), Biochemistry 37, 12603-12610; Oakley M. G, and Hollenbeck J. J. (2001), Curr Opin Struct Biol 11, 450-457; Stemmer W. P., Crameri A., Ha K. D., Brennan T. M., Heynecker H. L. (1995), Gene 164, 49-53; all incorporated herein by reference). In short, the primers were mixed in an equimolar concentration (12.5 μM of each primer) and assembled in 55 cycles of denaturation (94° C., 30 s), primer annealing (52° C., 30 s) and extension (72° C., 30 s) using 0.1 unit/μl Pwo polymerase and 0.5 mM of each dNTP in the gene assembly buffer (10 mM Tris-HCl, pH 8.8, 2.2 mM MgCl 2 , 50 mM KCl and 0.1% Triton X-100). The double gene was then amplified out of this reaction using Pwo polyirerase with the 5′-primer PTP116 that contains an EcoRI site and the 3′-primer PTP111 that contains a SalI site. The PCR product was cleaved with EcoRI and SalI and cloned into pRS316, resulting in pRS316-C1/2 (cf. Sikorski R. S, and Hieter, P. (1989), Genetics 122, 19-27, incorporated herein by reference). The final construct contained the sequences for an N-terminal FLAG tag, the polypeptide C1 followed by a five-residue linker, an HpaI blunt end restriction site and a six-residue-linker followed by the polypeptide C2 with a C-terminal HA tag. C1 and C2 are two peptides that associate into an antiparallel-coiled coil (cf. Oakley M. G., and Kim P. S. (1998), Biochemistry 37, 12603-12610; Oakley M. G, and Hollenbeck J. J. (2001), Curr Opin Struct Biol 11, 450-457). The sequence of the P CUP1 -promoter was then cleaved out of the plasmid pAGTM2-Dha with BamHI and EcoRI and positioned upstream of the C1/C2 cassette in pRS316-C1/2, resulting in pRS316-C1/2 CUP1 .
[0129] Cloning of pRS315 CUP1 , and of pRS316 CUP1 . The pRS315-derived vector was constructed for an easy cloning of the different N trp -SEC62 constructs, whereas the pRS316-derived vector was constructed for an easy cloning of the different SEC63-C trp constructs (cf. Sikorski R. S, and Hieter, P. (1989), Genetics 122, 19-27, incorporated herein by reference). The sequence of the P CUP1 -promoter of the plasmid pAGTM2-Dha was amplified by PCR with the primers PTP181 and PTP182. The gene of ECFP was amplified by PCR out of pLP-ECFP-C1 with the primers PTP183 and PTP184. Both fragments were then combined by overlap extension PCR using the 5′-primer PTP181 that contains a BamHI site and the 3′-primer PTP184 that contains a SalI site, so that the P CUP1 -promoter is upstream of ECFP (cf. Ho S. N. et al. (1989), Gene 1989, 51-59; incorporated herein by reference). The partially homologous primers PTP182 and PTP183 contain the sequence of the restriction sites EcoRI, BglII and AvrII to allow a versatile cloning of genes downstream of the P CUP1 -promoter. The final fragment consisting of P CUP1 -promoter and ECFP was then cloned into pRS315 or pRS316 with BamHI and SalI, resulting in pRS315 CUP1 or pRS316 CUP1 , (cf. Sikorski R. S, and Hieter, P. (1989), Genetics 122, 19-27).
[0130] To generate split-protein sensors based on Trp1p (split-Trp) we adapted an approach originally developed by Graf and Schachmann for creating random circular permutations of proteins (cf. Graf, R., and Schachman, H. K. (1996), Proc Natl Acad Sci USA 93, 11591-11596, incorporated herein by reference). Using PCR, the TRP1 gene of Saccharomyces cerevisiae was first rearranged so that it started with residue 63 and its former start codon was fused to the stop codon via a linker sequence encoding a unique AvrII restriction site. The N- and the C-terminal domains of TRP1 were therefore amplified separately out of the plasmid pY-ESTrp2 (Invitrogen) with the primers PTP113/115 and PTP112/114, respectively, and recombined using overlap extension PCR with the primers PTP112 and PTP115 (cf. Ho S. N. et al. (1989), Gene 1989, 51-59; incorporated herein by reference). This rearrangement was performed to avoid unwanted isolation of wild-type gene in the subsequent selections. At the same time, a HindIII restriction site was introduced via the PCR primers at the newly generated N- and C-termini by introducing a silent mutation in the gene at around amino acid 63. Since the direct digestion of PCR products in former experiments yielded a product that did not ligate efficiently, the rearranged gene was first inserted into a high-copy plasmid (pAK400) and, after amplification of the vector DNA, cut out with HindIII. The rearranged gene was then incubated with T4 DNA ligase at 16° C. for 14 h at a DNA concentration of 0.14 mg/ml, leading to the formation of circular DNA as well as dimers and higher oligomers. After inhibition of the ligase at 65° C. for 20 min and desalting of the solution using a microcon PCR column, the ligation products were incubated with DNaseI (˜1.2 units/mg DNA) in 50 mM Tris-HCl, pH 7.5, 1 mM MnCl 2 at 25° C. for six minutes. The exact conditions for the DNaseI reactions were determined immediately before the digestion in small test reactions. The DNaseI reaction was stopped by phenol extraction and ethanol precipitation. After incubation of the digested DNA with T4 DNA ligase and T4 polymerase to repair nicks, gaps and to flush the ends of the fragments, DNA fragments corresponding to the size of the original gene were isolated by gel electrophoresis. These fragments were ligated into the pRS316-based yeast expression vector pRS316-C1/2 CUP1 that was cleaved with HpaI and dephosphorylated according to standard protocols. In the resulting vector, the C-terminal half of TRP1 is fused to a gene encoding for a FLAG tag, a polypeptide C1 and a five-residue linker sequence and is expressed under the control of the P CUP1 -promoter. The N-terminal half of TRP1 is fused to a gene encoding for a six-residue linker sequence, the polypeptide C2 and a HA tag. The sequences of the peptides C1 and C2, including epitope tag and linker are:
(SEQ ID NO: 19) C1: MDYKDESGQALEKELAQNEWELQALEKELAQLEKELQAGSGSG, (SEQ ID NO: 20) C2: GGSGSGQALKKKLAQLKWKLQALKKKNAQLKKKLQAGSYPYDVPDY AAFL,
[0131] After transformation in XL1Blue, resulting in a library with about 3×10 4 independent clones, the bacteria were scratched from the plate, and the plasmids isolated and linearized with AvrII. To insert a terminator for the C-terminal fragment and a promoter for the N-terminal fragment, a DNA fragment was constructed by PCR consisting of the CYC1 terminator, a geneticin resistance gene, the P GAL1 -promoter and flanking regions of about 50 base pairs at the 5′-and 3′-ends homol ogous to the original N and C termini of Trp1p. The CYC1-terminator was amplified out of pYESTrp2 with the primers PTP107 and PTP120, whereas the cassette containing the geneticin resistance gene and the P GAL1 -promoter was amplified out of pFA6a-GAL1 with the primers PTP108 and PTP121. Both fragments were combined by overlap extension PCR using the primers PTP120 and PTP121 (cf. Ho S. N. et al. (1989), Gene 1989, 51-59; incorporated herein by reference). The linearized vector (0.3 μg) and the PCR fragment (3 μg) were then co-transformed in chemically competent EGY48 cells and plated on plates lacking uracil but containing geneticin (500 μg/ml) to select for insertion of the PCR fragment into the linearized vector through homologous recombination (cf. Oldenburg et al. (1997), Nucleic Acids Res 25, 451-452; incorporated herein by reference). Chemically competent yeast cells were prepared as described by standard protocols. The homologous recombination also suppressed the predominant isolation of TRP1 genes that were cut near the original N or C terminus. In the final construct, the C-terminal fragment fused to C1 (C1-C trp ) is under the control of the inducible but leaky P CUP1 -promoter and the N-terminal fragment fused to C2 (N trp -C2) is under the stringent control of the P GAL1 -promoter. After 3 days of incubation at 30° C., approximately 1600 colonies were isolated and subsequently replica-plated on plates lacking uracil and tryptophan but containing geneticin (250 μg/ml), galactose (2%) and CuSO 4 (0.1 MM). After replica plating, 45 colonies were able to complement tryptophan auxotrophy. Approximately half of those 45 colonies required the presence of galactose and CuSO 4 to grow on plates lacking tryptophan and twelve of these clones were then analyzed by DNA sequencing ( FIG. 2 ). Five of the twelve analyzed clones lead to the expression of Trp1p fragments in which both fragments were fused in frame to the polypeptides C1 and C2 (marked with an asterisk in FIG. 2 ). Seven of the twelve clones were out of frame with C1 or C2. These frame shifts resulted in the replacement of C2 in split-Trp 135 and split-Trp 170 with a peptide of 66 residues possessing the sequence
[0132] DLDQVRHLRRSWRSLSGNCKLLRRRMPSLRRSSRLEVTHMFQITLHFYKSTSRGGPVPSFCSL and in split-Trp 180 split-Trp 198 , split-Trp 203 and split-Trp 204b with a peptide of 10 residues possessing the sequence (E/Q)RWIWIRSGT. It is assumed that N trp and C trp of these clones associate spontaneously without the help of interacting proteins. In split-Trp 44 and split-Trp 204b the mutation Gly8Cys was introduced during the fragmentation procedure. However, the influence of this mutation seems to be of minor importance as the deletion of the first ten amino acids still allowed split-Trp 77 to complement tryptophan auxotrophy ( FIGS. 2 and 3 ).
[0133] For split-Trp 44 , split-Trp 53 , split-Trp 187 split-Tr 204b and split-Trp 77 the sequence encoding N trp -C2 was deleted from the plasmid using BglII and SalI and replaced with a PCR fragment encoding only the corresponding N trp -fragment. The resulting constructs were then retransformed into EGY48 ( FIG. 3 ). To test whether the trp1 complementation depends on the presence of both Trp1p fragments we repeated the growth assays on plates lacking tryptophan and galactose but containing glucose and copper, thereby repressing the expression of N trp -C 2 . Of the five clones tested, only split-Trp 77 conferred tryptophan auxotrophy to the trp1 yeast in the presence of glucose by itself, indicating that its large C-terminal fragment spanning residues 11-224 already possesses enzymatic activity. On galactose, split-Trp 44 , split-Trp 187 and split-Trp 77 complemented tryptophan auxotrophy at 30° C. and 23° C., whereas split-Trp 53 and split-Trp 204b complemented tryptophan auxotrophy only at 23° C. ( FIG. 3 ).
[0134] The deletion of C2 abolished the capacity of the four clones split-Trp 44 , split-Trp 53 , split-Trp 187 split-Trp 204b to complement tryptophan auxotrophy ( FIG. 3 ). This finding demonstrates that the formation of a functional Trp1p from these fragments indeed depends on the fusion to a pair of interacting polypeptides.
[0135] Since the structure of Trp1p from S. cerevisiae has not yet been solved, we aligned its sequence with the sequences of the N-(5′-phosphoribosyl)-anthranilate isomerases from E. coli (ePRAI) and Thermotoga maritima (tPRAI), and identified the fragmentation sites in the known crystal structures of the homologous enzymes ( FIG. 4 ). The fragmentation site of split-Trp 44 lies in one of the active site loops between β2 and α2, two residues away from an arginine residue that interacts with the carboxyl group of the substrate N-(5′-phosphoribosyl)-anthranilate. Although combinatorial mutagenesis experiments have indicated that turn sequences in general are highly mutable in (β/α)e-barrels, the vicinity of this position to an active site residue would not have made it an obvious candidate for a fragmentation site (cf. Silverman, J. A., Balakrishnan, R., and Harbury, P. B. (2001), Proc Natl Acad Sci USA 98, 3092-3097). In split-Trp 187 and split-Trp 53 the fragmentation sites are located in α-helices α7 and α2 of the (β/α) 8 -barrel, respectively. This appears plausible in hindsight with the mutability of α-helical residues in combinatorial mutagenesis experiments on (β/α) 8 -barrels and with earlier random circular permutation experiments of other folds in which new termini were introduced into α-helices (cf. Silverman, J. A., Balakrishnan, R., and Harbury, P. B. (2001), Proc Natl Acad Sci USA 98, 3092-3097; Graf, R., and Schachman, H. K. (1996), Proc Natl Acad Sci USA 93, 11591-11596). Furthermore, α-helix α2 is extended by nine amino acids in Trp1p compared to ePRAI and tPRAI, making it plausible that the introduction of a fragmentation site could be tolerated without significantly affecting the activity or the folding of the (β/α) 8 -barrel. Particularly interesting is split-Trp 204b , in which a stretch of eight amino acids (205-212), including four highly conserved residues, is deleted from Trp1p. This results in a very short C trp of only twelve residues that is fused to C1, corresponding to α-helix α8 in the structure of tPRAI and ePRAI. The eight deleted amino acids form a loop in the vicinity of the active site, directly after the short α-helix α8′. Helix α8′ is believed to participate in the binding of the phosphate group of the substrate and is not present in the regular structures of other (β/α) 8 -barrels (cf. Eder, J., and Kirschner, K. (1992), Biochemistry 31, 3617-3625; Hennig, M., Sterner, R., Kirschner, K., and Jansonius, J. N. (1997), Biochemistry 36, 6009-6016). While split-Trp 204b complements tryptophan auxotrophy only at 23° C., indicating a decreased stability of the split enzyme, this finding nevertheless questions the significance of this loop with its four completely conserved residues in the function of N-(5′-phopsphoribosyl)-anthranilate isomerases. However, it is unknown how much residual Trp1p activity is sufficient to complement tryptophan auxotrophy in yeast and a more detailed interpretation of this finding will therefore require the kinetic characterization of Split-Trp 204b in in vitro assays. Eder and Kirschner have shown that the N-terminal fragment 1-167 folds in the absence of its C-terminal partner (cf. Eder, J., and Kirschner, K. (1992), Bio-chemistry 31, 3617-3625). Furthermore, it has been proposed that this N-terminal subdomain is an intermediate in the folding of Trp1p (cf. Silverman, J. A., Balakrishnan, R., and Harbury, P. B. (2001), Proc Natl Acad Sci USA 98, 3092-3097; Kirschner, K., Szadkowski, H., Henschen, A., and Lottspeich, F. (1980), J Mol Biol 143, 395-409; Jasanoff, A., Davis, B., and Fersht, A. R. (1994), Biochemistry 33, 6350-6355; Silverman, J. A., and Harbury, P. B. (2002), J Mol Biol 324, 1031-1040; Sanchez del Pino, M. M., and Fersht, A. R. (1997), Biochemistry 36, 5560-5565). In agreement with these studies all of the selected split-Trp pairs that spontaneously assemble into a functional protein possess relatively large N-terminal fragments, incorporating at least the first five (β/α)-motives. This observation suggests that a spontaneous assembly of Trp1p fragments depends on the presence of a folded N-terminal domain and that the location of the fragmentation site reflects the folding pathway of the natural protein. Shorter N-terminal fragments such as 44 N trp and 53 N trp might not fold independently and the chances to spontaneously reconstitute active protein from unfolded fragments without induced proximity would be greatly diminished. Noteworthy, most of the isolated split-Trp pairs that reassemble spontaneously consist of Trp1p fragments that overlap for at least 13 residues. This overlap prevents us to exactly localize the fragmentation site from the sequence data ( FIG. 2 ). An exception is split-Trp 135 where, according to the structure of tPRAI, the fragmentation site is located in a loop at the N-terminal side of the (β/α) 8 -barrel.
[0000] Detection of Membrane Protein Interactions Using Split-Trp Sensors
[0136] An important application for new split-protein sensors will lie in the detection and characterization of protein-protein interactions occurring at the membranes of intracellular organelles and the cell membranes. To test whether the split-Trp system operates at the membrane, the interaction-dependent split-Trp pairs were attached to the membrane proteins Sec62p and Sec63p ( FIG. 4 ) (cf. Panzner, S., Dreier, L., Hartmann, E., Kostka, S., and Rapoport, T. A. (1995), Cell 81, 561-570; Deshaies, R. J., and Schekman, R. (1989), J Cell Biol 109, 2653-2664; Wittke, S., Dunnwald, M., and Johnsson, N. (2000), Mol Biol Cell 11, 3859-3871). Sec62p and Sec63p directly bind to each other and are part of the heptameric Sec-complex that is responsible for translocating proteins posttranslationally across the membrane of the endoplasmic reticulum (ER) ( FIG. 5A ). Briefly, SEC62 was fused to the 3′-end of the N-terminal fragment of the four split-Trp systems, allowing for the expression of 44 N trp -Sec62p, 53 N trp -Sec62p, 187 N trp -Sec62p and 204b N trp -Sec62p. SEC63 was fused to the 5′-end of the corresponding C-terminal fragments, allowing for the expression of Sec63p- 44 C trp , Sec63p- 53 C trp , Sec63p- 187 C trp and Sec63p- 204b C trp .
[0137] To monitor the interaction between Sec62p and Sec63p, trp1 yeast strains expressing pairs of matching N trp -Sec62p and Sec63p-C trp fusion proteins were spotted on selective plates lacking tryptophan ( FIG. 5 ). Strains co-expressing 44 N trp -Sec62p/Sec63p- 44 C trp , 187 N trp -Sec62p/Sec63p- 187 C trp and 204b N trp -Sec62p/Sec63p- 204b C trp were able to grow on plates lacking tryptophan at 23° C. but not at 30° C. Only small colonies were detected after 7 days for 187 N trp -Sec62p/Sec63p- 187 C trp and after 10 days for 204b N trp -Sec62p/Sec63p- 204b C trp , whereas strains co-expressing 44 N trp -Sec62p/Sec63p- 44 C trp grew significantly faster. No growth at all was observed for strains expressing 53 N trp -Sec62p/Sec63p- 53 C trp . To verify that the observed complementation of tryptophan auxotrophy is a result of the interaction between the Sec62p and Sec63p moieties of the fusion proteins, we fused the C-terminal fragments of split-Trp 44 and split-Trp 187 to the cytoplasmic site of Ste14p ( FIG. 4B ). Ste14p is a membrane protein of the ER that is known to interact with neither Sec62p nor Sec63p ( FIG. 4B ) (cf. Wittke, S., Lewke, N., Muller, S., and Johnsson, N. (1999), Mol Biol Cell 10, 2519-2530). No growth on plates lacking tryptophan was observed when matching pairs of Sec62p and Ste14p fusion proteins were co-expressed at 23° C. or 30° C. for 10 days ( FIG. 5 ). The cellular amount of Ste14p- 44 C trp is roughly 2-3 fold lower than the amount of Sec63p- 44 C trp as determined by western blotting (data not shown). Since this relatively small effect cannot account for the clear growth difference between the strains expressing either 44 N trp -Sec62p/Sec63p- 44 C trp or 44 N trp -Sec62p/Ste14p- 44 C trp , we conclude that the 44 N trp -Sec62p/Sec63p- 44 C trp interaction signal is specific.
[0138] In more detail, the gene of SEC62 was amplified by PCR from yeast EGY48 genomic DNA and combined by overlap extension PCR with the N-terminal fragments of split-Trp 44 , split-Trp 53 , split-Trp 187 and split-Trp 204b , yielding 44 N trp -SEC62, 53 N trp -SEC62, 187 -N trp -SEC62 and 204b N trp -SEC62. At the same time, a 6× His tag was introduced at the 5′-end of N trp . The N trp genes and SEC62 are connected by a sequence coding for a six-residue linker (GGSGSG). The four N trp -SEC62 PCR products were isolated by gel electrophoresis and ligated in a pRS315-derived expression vector (LEU2) (pRS315 CUP1 ) under the control of the P CUP1 -promoter. Towards this aim, the vector was cleaved with BglII and SalI and the ECFP gene was replaced by the corresponding N trp -SEC62 construct.
[0139] The genes of SEC63 and STE14 were amplified by PCR from yeast EGY48 genomic DNA and combined by overlap extension PCR with the C-terminal fragments of split-Trp 44 , split-Trp 53 , split-Trp 187 and split-Trp 204b . At the same time, a 6× His tag was introduced at the 3′-end of C trp , yielding SEC63- 44 C trp -His, SEC63- 53 C trp -His, SEC63- 187 C trp -His, SEC63- 204b C trp -His, STE14- 44 C trp -His and STE14- 187 C trp -His. SEC63 and the C trp -His genes are connected by a sequence coding for a six-residue linker (GGSGSG). The different SEC63-C trp -His and STE14-C trp -His PCR products were isolated by gel electrophoresis and ligated into a pRS316-derived vector (URA3) (pRS316 CUP1 , vide supra) under the control of the P CUP1 -promoter. To replace the 6× His tag by the more sensitive HA tag the genes of the different SEC63-C trp -His and STE14-C trp -His constructs were amplified by PCR with a 3′-primer that contains an HA tag and cloned into pRS316 CUP1 . All SEC63 and STE14 fusions contained an HA tag fused to the C terminus of Trp1p. The vector was cleaved with BglII and SalI and the ECFP gene was replaced with the corresponding SEC63-C trp and STE14-C trp constructs. All constructs were verified by DNA sequencing.
[0140] Expression of N trp -Sec62p fusion proteins. Expression and functionality of the N trp -Sec62p fusion proteins was confirmed by complementation of the temperature-sensitive yeast strain RSY529 (MATα his4 leu2-3, 112 ura3-52 sec62-1) (cf. Rothblatt J. A. et al. (1989), J Cell Biol 109, 2641-2652). RSY529 contains an endogenous temperature-sensitive variant of Sec62p. A colony of RSY529 cells transformed with either pRS315 or a pRS315-derived vector expressing 44 N trp -Sec62p, 53 N trp -Sec62p, 187 N trp -Sec62p or 204b N trp -Sec62p was resuspended in 1 ml water and 5 μl were spotted on YC-L medium containing 0.1 mM CuSO 4 to induce the expression of the fusion proteins and incubated at 30° C. and 38° C. for 6 d to control for the complementation of the temperature sensitivity of RSY529.
[0141] Expression of Sec63p-C trp and Ste14p-C trp fusion proteins. The expression of the different Sec63p-C trp and Ste14p-C trp fusion proteins was verified by immunoblotting using antibodies against the HA tag at the C terminus of Trp1p. Towards this aim, an overnight culture of yeast EGY48 cells containing one of the Sec63p-C trp or Ste14p-C trp fusion proteins was diluted in 10 ml selective medium YC-U to an OD 600 ˜0.8 and grown for 3 h at 30° C. and 220 rpm. Protein expression was induced by adding CuSO 4 to a final concentration of 0.1 mM. After 3 h of expression at 30° C. and 220 rpm, the cell solution (same volume at same OD when different samples were compared) was centrifuged at 4300 rpm for 10 minutes and the pellet resuspended in 150 μl yeast lysis buffer (50 mM HEPES, pH 7.5, 150 mM NaCl, 5 mM EDTA, 1% Triton X-100) containing 1% (v/v) protease inhibitor cocktail and 0.5 mM PMSF. 200 gl glass beads were added and the solution was vortexed at full speed for 3×30 s and cooled on ice in between the vortexing steps. The glass beads and the cell debris were pelleted by centrifugation for 30 s at 13000 rpm and the supernatant was mixed with an appropriate volume of 5×SDS sample buffer (50% glycerol, 7.5% SDS, 250 mM Tris-HCl, pH 8.0, 0.5% Bromphenol blue, 12.5 mM 2-Mercaptoethanol). Proteins were denatured for 3 min at 95° C. Aliquots were analysed by Western blotting (12% SDS-PAGE) as described by standard protocols. After blotting, the nitrocellulose membrane was incubated with 3% dry milk in TBST (10 mM Tris-HCl, 150 mM NaCl, pH 7.9, 0.05% Tween 20) to block unspecific antibody binding. Expression of Sec63p-C trp or Ste14p-C trp fusion constructs was controlled by incubation of the membrane with the primary anti-HA antibody 1:7500 in TBST (10 mM Tris-HCl, 150 mM NaCl, pH 7.9, 0.05% Tween 20). An anti mouse-HRP antibody conjugate was used 1:7500 in TBST (10 mM Tris-HCl, 150 mM NaCl, pH 7.9, 0.05% Tween 20) as secondary antibody. Detection was done on a Kodak Image Station 440CF using the NEN Renaissance kit, a luminol-based chemiluminescence system.
[0142] The present data demonstrate that in particular split-Trp 44 is well suited for the detection of protein-protein interactions between membrane proteins. Interestingly, yeast cells co-expressing 44 N trp -Sec62p and Sec63p- 44 C trp require lower growth temperatures for the complementation of tryptophan auxotrophy than the cells expressing the corresponding C1 and C2 coiled coil fusions. This effect might be due to a more favorable orientation of the N- and C-terminal Trp1p fragments in the antiparallelcoiled coil than in the Sec62p/Sec63p complex.
[0143] In conclusion, we have used directed evolution to convert N-(5′-phosphoribosyl)-anthranilate isomerase into a split-protein sensor. In coupling the interaction of cytosolic and membrane proteins to a simple growth assay, the split-Trp system possesses all the necessary features to complement already existing systems to measure and screen for new protein interactions. This split-Trp approach may be used in identifying partners of medically relevant targets, e.g. in three-hybrid assays and protein/small molecule interaction assays. Furtherrmore, the evolutionary approach introduced here is generally applicable to other enzymes. By generating novel split-protein sensors that are based on proteins functioning in the matrix of e.g. the mitochondrium, the peroxisome or the lumen of the secretory path, this evolutionary approach will help to overcome the lack of techniques to measure protein interactions in the interior of these organelles. Finally, the analysis of the different split-Trp pairs that either spontaneously assemble into a functional (β/α) 8 -barrel or need to be fused to interacting proteins to yield folded protein supports the hypothesis that a large N-terminal subdomain of Trp1p is an important intermediate in the folding of the (β/α)8-barrel.
[0000] Further Experimental Details
[0144] For the various PCR- and gene assembly reactions, if not already noted explicitly above, the following primers and templates were used.
[0145] Primers used for N trp -constructs (cf. attached sequence listing for details):
cloning construct 5′-primer 3′-primeir template(s) sites 44 N trp PTP193 PTP146 split-Trp 44 — SEQ ID NO: 55 SEQ ID NO: 65 44 N trp -HA PTP199 PTP146 split-Trp 44 — SEQ ID NO: 59 SEQ ID NO: 65 43 N trp PTP193 PTP170 split-Trp 53 — SEQ ID NO: 55 SEQ ID NO: 43 187 N trp PTP193 PTP172 split-Trp 187 — SEQ ID NO: 55 SEQ ID NO: 45 204b N trp PTP193 PT2174 split-Trp 204b — SEQ ID NO: 55 SEQ ID NO: 47 SEC62 PTP147 PTP188 EGY48 yeast geno- — SEQ ID NO: 66 SEQ ID NO: 53 mic DNA 44 N trp -SEC62 PTP193 PTP188 44 N trp / SEC62, over- Bgl II/ Sal I SEQ ID NO: 55 SEQ ID NO: 53 lap extension PCR 53 N trp -SEC62 PTP193 PTP188 53 N trp / SEC62, over- Bgl II/ Sal I SEQ ID NO: 55 SEQ ID NO: 53 lap extension PCR 187 N trp -SEC62 PTP193 PTP188 187 N trp / SEC62, over- Bgl II/ Sal I SEQ ID NO: 55 SEQ ID NO: 53 204b N trp -SEC62 PTP193 PTP188 204b N trp / SEC62, over- Bgl II/ Sal I SEQ ID NO: 55 SEQ ID NO: 53 lap extension PCR
[0146] Primers used for C trp -constructs (cf. attached sequence listing for details):
cloning construct 5′-primer 3′-primer template(s) sites 44 C trp -His PTP155 PTP194 split-Trp 44 — SEQ ID NO: 41 SEQ ID NO: 56 44 C trp -HA PTP155 PTP198 split-Trp 44 — SEQ ID NO: 41 SEQ ID NO: 58 53 C trp -His PTP171 PTP194 split-Trp 53 — SEQ ID NO: 44 SEQ ID NO: 56 187 C trp -His PTP173 PTP194 split-Trp 187 — SEQ ID NO: 46 SEQ ID NO: 56 204b C trp -His PTP175 PTP194 assembly PCR with — SEQ ID NO: 48 SEQ ID NO: 56 primers PTP175, PTP176, PTP179, PTP180, PTP191, PTP192 SEC63 2TP189 PTP154 EGY48 yeast geno- — SEQ ID NO: 54 SEQ ID NO: 40 mic DNA STE14 PTP195 PTP157 EGY48 yeast geno- — SEQ ID NO: 57 SEQ ID NO: 42 mic DNA SEC63- 44 C trp -HIS PTP189 PTP194 SEC63/ 44 C trp -His, Bgl II/ Sal I SEQ ID NO: 54 SEQ ID NO: 56 overlap extension PCR SEC63- 53 C trp -His PTP189 PTP194 SEC63/ 53 C trp -His, Bgl II/ Sal I SEQ ID NO: 54 SEQ ID NO: 56 overlap extension PCR SEC63- 187 C trp -His PTP189 PTP194 SEC63/ 187 C trp -His, Bgl II/ Sal I SEQ ID NO: 54 SEQ ID NO: 56 overlap extension PCR SEC63- 204 C trp -His PTP189 PTP194 SEC63/ 204 C trp -His, Bgl II/ Sal I SEQ ID NO: 54 SEQ ID NO: 56 overlap extension PCR STE14- 44 C trp -His PTP189 PTP194 STE14/ 44 C trp -His, Bgl II/ Sal I SEQ ID NO: 54 SEQ ID NO: 56 overlap extension PCR STE14- 187 C trp -His PTP195 PTP194 STE14- 187 C trp -His, Bgl II/ Sal I SEQ ID NO: 57 SEQ ID NO: 56 overlap extension PCR SEC63- 44 C trp PTP189 PTP198 SEC63- 44 C trp -His Bgl II/ Sal I SEQ ID NO: 54 SEQ ID NO: 58 SEC63- 53 C trp PTP189 PTP198 SEC63- 53 C trp -His Bgl II/ Sal I SEQ ID NO: 54 SEQ ID NO: 58 SEC63- 187 C trp PTP189 PTP198 SEC63- 187 C trp -His Bgl II/ Sal I SEQ ID NO: 54 SEQ ID NO: 58 SEC63- 204b C trp PTP189 PTP198 SEC63- 204 C trp -His Bgl II/ Sal I SEQ ID NO: 54 SEQ ID NO: 58 STE14- 44 C trp PTP195 PTP198 STE14- 44 C trp -His Bgl II/ Sal I SEQ ID NO: 57 SEQ ID NO: 58 STE14- 187 C trp PTP195 PTP198 STE14- 187 C trp -His Bgl II/ Sal I SEQ ID NO: 57 SEQ ID NO: 58
[0147] Primers used for zipper construction (cf. attached sequence listing for details):
SEQ ID NO: 22: PTP22 SEQ ID NO: 23: PTP23 SEQ ID NO: 24: PTP24 SEQ ID NO: 25: PTP28 SEQ ID NO: 26: PTP29 SEQ ID NO: 27: PTP100 SEQ ID NO: 28: PTP110 SEQ ID NO: 29: PTP111 SEQ ID NO: 34: PTP116 SEQ ID NO: 35: PTP117 SEQ ID NO: 36: PTP118 SEQ ID NO: 37: PTP119
[0148] Primers used for the copper promoter (cf. attached sequence listing for details):
SEQ ID NO: 49: PTP181 SEQ ID NO: 50: PTP182 SEQ ID NO: 51: PTP183 SEQ ID NO: 52: PTP184
[0149] Primers used for circular permutation of Trp1p (cf. attached sequence listing for details):
SEQ ID NO: 30: PTP112 SEQ ID NO: 31: PTP113 SEQ ID NO: 32: PTP114 SEQ ID NO: 33: PTP115
[0150] Primers used for homologous recombination (cf. attached sequence listing for details):
SEQ ID NO: 63: PTP107 SEQ ID NO: 64: PTF108 SEQ ID NO: 38: PTP120 SEQ ID NO: 39: PTP121
[0151] | The invention concerns a combinatorial method for the generation of new split-protein sensors, and its application towards the (β/αa) 8 -barrel enzyme N-(5′-phosphoribosyl)-anthranilate isomerase Trp1p from Saccharomyces cerevisiae is demonstrated. The generated split-Trp protein sensors allow for the detection of protein-protein interactions in the cytosol as well as the membrane by enabling trp1 cells to grow on medium lacking tryptophan. This powerful selection thus complements the repertoire of the currently used split-protein sensors and provides a new tool for high-throughput interaction screening. | 2 |
TECHNICAL FIELD
The present invention relates to the use of hydroxyl-containing tertiary amines as catalysts for producing polyurethanes.
BACKGROUND OF THE INVENTION
Polyurethane foams are widely known and used in automotive, housing and other industries. Such foams are produced by reaction of a polyisocyanate with a polyol in the presence of various additives. One such additive is a chlorofluorocarbon (CFC) blowing agent which vaporizes as a result of the reaction exotherm, causing the polymerizing mass to form a foam. The discovery that CFC's deplete ozone in the stratosphere has resulted in mandates diminishing CFC use. Production of water-blown foams, in which blowing is performed with CO 2 generated by the reaction of water with the polyisocyanate, has therefore become increasingly important. Tertiary amine catalysts are typically used to accelerate blowing (reaction of water with isocyanate to generate CO 2 ) and gelling (reaction of polyol with isocyanate).
The ability of the tertiary amine catalyst to selectively promote either blowing or gelling is an important consideration in selecting a catalyst for the production of a particular polyurethane foam. If a catalyst promotes the blowing reaction to a too high degree, much of the CO 2 will be evolved before sufficient reaction of isocyanate with polyol has occurred, and the CO 2 will bubble out of the formulation, resulting in collapse of the foam. A foam of poor quality will be produced. In contrast, if a catalyst too strongly promotes the gelling reaction, a substantial portion of the CO 2 will be evolved after a significant degree of polymerization has occurred. Again, a poor quality foam, this time characterized by high density, broken or poorly defined cells, or other undesirable features, will be produced.
Tertiary amine catalysts generally are malodorous and offensive and many have high volatility due to low molecular weight. Release of tertiary amines during foam processing may present significant safety and toxicity problems, and release of residual amines from consumer products is generally undesirable.
Amine catalysts which contain primary and/or secondary hydroxyl functionality typically have limited volatility and low odor when compared to related structures which lack this functionality. Furthermore, catalysts which contain hydroxyl functionality chemically bond into the urethane during the reaction and are not released from the finished product. Catalyst structures which embody this concept are typically of low to moderate activity and promote both the blowing (water-isocyanate) and the gelling (polyol-isocyanate) reactions to varying extents. Examples of such structures are included in the following references: U.S. Pat. Nos. 4,957,944; 5,071,809 and 5,091,583.
Secondary alcohols are preferred in the structures, because these catalysts exhibit a desirable balance between their promotion of the active hydrogen-isocyanate reactions and their own reactivity with isocyanates. In contrast, catalysts which contain primary alcohols react rapidly with isocyanates and thus high use levels are required. Catalysts which contain tertiary hydroxyls react slowly with isocyanates, but the urethanes of tertiary hydroxyls which are formed have poor thermal stability. These urethanes may degrade and release the catalyst at temperatures substantially below the decomposition temperature of the foam itself. The free amine could then accelerate foam decomposition.
A catalyst which strongly promotes the water-isocyanate (blowing) reaction is advantageous for the manufacture of many polyurethane foams. Such catalysts include the β-(N,N-dimethylamino)alkyl ethers, in particular bis(dimethylamino)ethyl ether. Low odor, reactive catalysts structurally related to bis(dimethylamino)ethyl ether are described in U.S. Pat. Nos. 4,338,408 and 4,433,170. In particular, 2-[N-(dimethylaminoethoxyethyl)-N-methylamino]ethanol, Texacat® ZF-10 catalyst, is an effective blowing catalyst, albeit less effective than bis(dimethylamino)ethyl ether.
Linear, permethylated di-, tri-, and polyamines are also known to promote the water-isocyanate reaction.
U.S. Pat. No. 3,836,488 discloses the use of tris[2-(dimethylamino)ethyl]amine as a catalyst for making urethanes by reacting polyisocyanate with active hydrogen containing compounds.
U.S. Pat. No. 4,143,003 discloses a process for the production of polyurethane foam resins in which linear polyamines containing at least 4 tertiary nitrogen atoms are used as catalysts. Such catalysts include hexamethyltriethylenetetramine and heptamethyltetraethylenepentamine.
U.S. Pat. No. 5,039,713 discloses a blowing catalyst consisting essentially of 25 to 80 wt % pentamethyldiethylenetriamine and 20 to 75 wt % bis(dimethylaminopropyl)methylamine.
U.S. Pat. No. 4,026,840 discloses that the reaction of isocyanate with polyols to form polyurethanes and their polymerization to polyisocyanurates are promoted by certain hydroxyalkyl tertiary amine catalysts corresponding to the formula: ##STR2## wherein Y is CH 3 or Z,
Z is --CH 2 CH 2 OH, and
n is 1 or 2.
EP 0 469 545 A2 (U.S. Pat. No. 5,229,430) discloses an amine catalyst for producing polyurethane comprising a compound of the general formula: ##STR3## wherein R 1 , R 2 and R 3 respectively and independently are alkyl groups having 1 to 3 carbon atoms, and
n is an integer from 0 to 3.
The amine catalyst has a secondary hydroxyl group in the molecule and is claimed to be non-bleeding in the polyurethane resin.
Alkylene oxide adducts of polyamines are also used as polyols for the production of polyurethanes.
U.S. Pat. No. 5,064,957 discloses the hexakis propylene oxide adduct of tris(2-aminoethyl)amine as a precursor to the morpholine-containing polyurethane catalyst, but the propylene oxide adduct itself is not noted as having catalytic activity.
N. Malwitz, et al, J. Cell. Plastics, 1987, vol 23, pp 461-502, compared Me 2 NCH 2 CH 2 N(Me)CH 2 CH 2 OH and Me 2 NCH 2 CH 2 N(Me)CH 2 CH 2 CH 2 OH and found that the hydroxypropyl group shifted the selectivity toward gelling.
SUMMARY OF THE INVENTION
The present invention provides a composition for catalyzing the trimerization of an isocyanate and the reaction between an isocyanate and a compound containing a reactive hydrogen, e.g., the blowing reaction and the urethane reaction for making polyurethane. The catalyst composition consists essentially of a compound having the following formula I: ##STR4## wherein R is hydrogen, a C 1 -C 4 alkyl, C 6 -C 8 aryl, or C 7 -C 9 aralkyl group; and
n is an integer from 1 to 8.
The advantage of these catalysts is that activities and selectivities are variable and they vary in a systematic fashion. Blowing selectivity increases as the number of carbon atoms between the hydroxyl group and the central nitrogen increases, allowing the catalyst characteristics to be more easily optimized for a specific application. An alteration in selectivity based on this structural feature has not been previously appreciated. Furthermore, the activity of the hydroxypropyl derivative (n=1; R=Me) is significantly higher than that of the terminally propoxylated permethyldiethylenetriamine isomer of the prior art. The art suggests that variation of the activity of functional tertiary amine catalysts can be achieved by diminishing alcohol reactivity or by increasing the number of tertiary nitrogen atoms in the catalyst. A difference in the activity of these two isomers is therefore unexpected.
DETAILED DESCRIPTION OF THE INVENTION
The catalyst compositions according to the invention can catalyze (1) the reaction between an isocyanate functionality and an active hydrogen-containing compound, i.e. an alcohol, a polyol, an amine or water, especially the urethane (gelling) reaction of polyol hydroxyls with isocyanate to make polyurethanes and the blowing reaction of water with isocyanate to release carbon dioxide for making foamed polyurethanes, and/or (2) the trimerization of the isocyanate functionality to form polyisocyanurates.
The polyurethane products are prepared using any suitable organic polyisocyanates well known in the art including, for example, hexamethylene diisocyanate, phenylenediisocyanate, toluene diisocyanate ("TDI") and 4,4'-diphenylmethane diisocyanate ("MDI"). Especially suitable are the 2,4- and 2,6-TDI's individually or together as their commercially available mixtures. Other suitable isocyanates are mixtures of diisocyanates known commercially as "crude MDI", also known as PAPI, which contain about 60% of 4,4'-diphenylmethane diisocyanate along with other isomeric and analogous higher polyisocyanates. Also suitable are "prepolymers" of these polyisocyanates comprising a partially prereacted mixture of a polyisocyanates and a polyether or polyester polyol.
Illustrative of suitable polyols as a component of the polyurethane composition are the polyalkylene ether and polyester polyols. The polyalkylene ether polyols include the poly(alkylene oxide) polymers such as poly(ethylene oxide) and poly(propylene oxide) polymers and copolymers with terminal hydroxyl groups derived from polyhydric compounds, including diols and triols; for example, among others, ethylene glycol, propylene glycol, 1,3-butane diol, 1,4-butane diol, 1,6-hexane diol, neopentyl glycol, diethylene glycol, dipropylene glycol, pentaerythritol, glycerol, diglycerol, trimethylol propane and like low molecular weight polyols.
In the practice of this invention, a single high molecular weight polyether polyol may be used. Also, mixtures of high molecular weight polyether polyols such as mixtures of di- and trifunctional materials and/or different molecular weight or different chemical composition materials may be used.
Useful polyester polyols include those produced by reacting a dicarboxylic acid with an excess of a diol, for example, adipic acid with ethylene glycol or butanediol, or reacting a lactone with an excess of a diol such as caprolactone with propylene glycol.
In addition to the polyether and polyester polyols, the masterbatches, or premix compositions, frequently contain a polymer polyol. Polymer polyols are used in polyurethane foam to increase the foam's resistance to deformation, i.e. to increase the load-bearing properties of the foam. Currently, two different types of polymer polyols are used to achieve load-bearing improvement. The first type, described as a graft polyol, consists of a triol in which vinyl monomers are graft copolymerized. Styrene and acrylonitrile are the usual monomers of choice. The second type, a polyurea modified polyol, is a polyol containing a polyurea dispersion formed by the reaction of a diamine and TDI. Since TDI is used in excess, some of the TDI may react with both the polyol and polyurea. This second type of polymer polyol has a variant called PIPA polyol which is formed by the in-situ polymerization of TDI and alkanolamine in the polyol. Depending on the load-bearing requirements, polymer polyols may comprise 20-80% of the polyol portion of the masterbatch.
Other typical agents found in the polyurethane foam formulations include chain extenders such as ethylene glycol and butanediol; crosslinkers such as diethanolamine, diisopropanolamine, triethanolamine and tripropanolamine; blowing agents such as water, methylene chloride, trichlorofluoromethane, and the like; and cell stabilizers such as silicones.
A general polyurethane flexible foam formulation having a 1-3 lb/ft 3 (16-48 kg/m 3 ) density (e.g., automotive seating) containing a gelling catalyst such as triethylenediamine (TEDA) and a blowing catalyst such as the catalyst composition according to the invention would comprise the following components in parts by weight (pbw):
______________________________________Flexible Foam Formulation pbw______________________________________Polyol 20-100Polymer Polyol 80-0Silicone Surfactant 1-2.5Blowing Agent 2-4.5Crosslinker 0.5-2Catalyst 0.5-2Isocyanate Index 70-115______________________________________
The blowing catalyst composition consists essentially of a compound represented by formula I. ##STR5## where R is hydrogen, C 1 -C 4 alkyl, C 6 -C 8 aryl, or C 7 -C 9 aralkyl group and n is 1 to 8; R is preferably hydrogen or an alkyl group, and is especially methyl; n is preferably 1 to 3, especially 2 or 3.
Compounds of formula I are generally prepared by the reaction of N,N,N",N"-tetramethyldiethylenetriamine with alkylene oxides or with suitable lactones followed by reduction of the carbonyl.
A catalytically effective amount of the catalyst composition is used in the polyurethane formulation. More specifically, suitable amounts of the catalyst composition may range from about 0.01 to 10 parts per 100 parts polyol (phpp) in the polyurethane formulation.
The catalyst composition may be used in combination with other tertiary amine, organotin and carboxylate urethane catalysts well known in the urethane art.
The catalyst compositions of the invention unexpectedly exhibit blowing selectivities which increase as the number of methylene groups between the central nitrogen and the hydroxyl group increases. This provides a convenient means of optimizing the catalyst characteristics required for a specific application. Furthermore, the activity of the hydroxypropyl derivative (n=1; R=Me) is significantly higher than that of the terminally propoxlylated permethyldiethylenetriamine isomer of the prior art. A difference in the activity of two isomers is unexpected.
EXAMPLE 1
N,N,N",N"-Tetramethyldiethylenetriamine (TMDETA)
A 2 L stainless steel autoclave was charged with Raney® 2800 nickel catalyst (28.22 g), water (20.7 g) and N,N-dimethylethylenediamine (DMEDA, 445.9 g, 5.058 mole). The reactor was sealed and pressure checked, and three pressure vent cycles with nitrogen and hydrogen were performed. The reactor was pressured to 500 psi (3447 kPa) with hydrogen and the reaction mixture was heated to 120° C. The hydrogen pressure was increased to 750 psi (5171 kPa) and distilled N,N-dimethylaminoacetonitrile (DMAAcN) was admitted by means of an HPLC pump at a rate of 1.5 mL/min until 415 g (4.933 mole) has been charged in the reactor. The total addition time was 5 hours. Hydrogen uptake continued for 4 hours after the nitrile addition had been completed. GC analysis of the product showed that N,N,N",N"-tetramethyldiethylenetriamine constituted 20% of the product; the remainder was N,N-dimethylethylenediamine (66%) and other byproducts (12%).
A second run was performed in an analogous fashion except that the reaction pressure was 1200 psi (8274 kPa). Hydrogen uptake stopped as soon as the nitrile addition had been completed. GC analysis showed that reaction product contained 32% N,N,N",N"-tetramethyldiethylenetriamine (64% selectivity based on DMAAcN), 63% N,N-dimethylethylenediamine, and 1% other byproducts.
The two reaction products (1415 g) were combined in a 3 L round-bottomed flask and distilled through a 40"×1" (102×2.54 cm) id Propack® column. DMEDA and low boiling impurities (837 g) were removed at 20 torr (2.67 kPa) and 49° C. Approximately 150 g were lost through the pump. The remaining material (409 g) was transferred to a 1 L flask and distilled at 100 torr (13.3 kPa). N,N,N",N"-tetramethyldiethylenetriamine boiled at 128° C. A total of 271 g was collected. The identity of the product was established by 1 H and 13 C NMR.
EXAMPLE 2
N,N,N",N"-Tetramethyl-N'-2-hydroxypropyldiethylenetriamine (TMHPDETA)
N,N,N",N"-Tetramethyldiethylenetriamine (TMDETA, 24.96 g, 157.2 mmole) and propylene oxide (PO, 9.1 g, 157.0 mmole) were charged to a 50 mL autoclave. The reactor was sealed, the contained air was replaced with nitrogen, the reactor was pressured to 100 psi (689 kPa) with nitrogen, and the contents were heated to 120° C. Analysis of samples withdrawn after 6 and 22 hours showed that little change in composition had occurred after the first 6 hours. After 22 hours, the reaction mixture was cooled to ambient temperature and the product was removed. GC analysis of the crude product showed that it contained 4.8% unreacted TMDETA and 82.3% TMHPDETA.
A second run was performed using 14.88 g (93.7 mmole) of TMDETA and 8.28 (142.9 mmole) of PO. GC analysis after 23 hours showed that the reaction mixture contained 10.4% unreacted TMDETA and 82.2% TMHPDETA. The combined crude products were purified by vacuum distillation using a Vigreux column. The unreacted starting amine boiled at 82° C. (0.24 torr; 0.032 kPa); N,N,N",N"-tetramethyl-N'-(2-hydroxypropyl)diethylenetriamine boiled at 110° C. (0.125 torr; 0.0167 kPa). TMHPDETA was identified by 1 H and 13 C NMR and mass spectrometry.
EXAMPLE 3
N,N,N",N"-Tetramethyl-N'-3-hydroxybutyldiethylenetriamine (TMHBDETA)
β-Butyrolactone (5.28 g, 61.4 mmole) was added at a rate of 1.2 mL/hr to a flask containing TMDETA (10.0 g, 65.5 mmole) heated to 100° C. Samples were withdrawn periodically for GC analysis. After 5 hours the concentration of N,N,N", N"-tetramethyldiethylenetriamine-N'-3-hydroxybutyramide had reached 70%. The reaction was discontinued and the product was isolated by shortpath vacuum distillation (bp 145° C., 0.2 torr; 0.0267 kPa). The amide was identified by GCMS.
Lithium aluminum hydride (26 mL, 1M solution in THF, 26 mmole) was charged to a nitrogen-purged, oven-dried flask. A solution of the butyramide (6.38 g, 25.9 mmole) in THF (25 mL) was added at a rate of 0.37 mL/min to the LiAlH 4 solution heated to 63° C. After the addition was completed, the solution was stirred for an additional 15 minutes and the LiAlH 4 was deactivated by successively adding water (1.12 g), 15% NaOH (1.14 g) and water (3.42 g). The resulting solids were removed by vacuum filtration and the amine (1.83 g) was isolated from the filtrate by Kugelrohr distillation at 94° C. and 85 millitorr (0.0113 kPa). TMHBDETA was identified by nuclear magnetic resonance and mass spectrometry.
EXAMPLE 4
N,N,N",N"-Tetramethyl-N'-4-hydroxyamyldiethylenetriamine (TMHADETA)
TMDETA (10.0 g, 63.0 mmole), γ-valerolactone (63.4 mmole) and titanium (IV) isopropoxide (2.13 g, 7.5 mmole) were weighed into a 100 mL flask. The flask was fitted with a nitrogen inlet, reflux condenser, and thermometer, and the contents were heated to 100° C. Samples removed periodically for GC analysis showed that the reaction was complete after 24 hours. The reaction mixture was cooled and the catalyst was deactivated by adding water (5 mL) and diethyl ether (10 mL) to the reaction vessel. The ether was removed and the amide (3.2 g) was isolated from the resulting solids by Kugelrohr distillation (bp 162° C., 0.4 torr; 0.053 kPa). The product was identified by GCMS.
The amide could also be prepared by the following alternate procedure: TMDETA (37.2 g, 234 mmole) was added dropwise to a flask containing water (6.46 g, 359 mmole) and γ-valerolactone (35.9 g, 359 mmole). The reaction mixture was heated at 100° C. for 18 hours. GC analysis showed that the concentration of amide was no longer changing significantly. The unreacted TMDETA and lactone were removed by short path distillation. Kugelrohr distillation (bp 140° C., 0.3 torr; 0.040 kPa) afforded 9.7 g of amide of 79% purity.
A solution of the amide (2.79 g, 10.8 mmole) in THF (15 mL) was added via syringe over a period of about 1 hour to a solution of LiAlH 4 (11 mL, 1M solution in THF, 11 mmole) heated to 63° C. in an oven-dried, nitrogen-purged flask. After the addition had been completed, the LiAlH 4 was deactivated by careful addition of water (0.47 g), 15% NaOH (0.47 g) and water (1.28 g). Removal of the resulting solids by vacuum filtration and distillation of the filtrate afforded TMHADETA (bp 120° C., 0.33 torr; 0.044 kPa). The product was identified by nuclear magnetic resonance and mass spectrometry.
COMPARATIVE EXAMPLE 1
N-(2-Hydroxypropyl)-N,N',N",N" -tetramethyldiethylenetriamine (Me 4 DETA-PO)
Diethylenetriamine (1000 g, 9.695 mole) was heated to 60° C. in 1 liter round-bottomed flask. The flask was fitted with a thermometer and a reflux condenser. Propylene oxide (510 mL, 7.288 mole) was added in 25 mole % increments using a pump. The reaction was monitored by GC to maximize the yield of monopropoxylate. The unreacted starting material was removed by distillation at 85° C. head temperature, 2 torr (0.267 kPa). The monopropoxylated product distilled at 125° C. head temperature, 2 torr (0.267 kPa). The monopropoxylated product was an inseparable mixture of terminally and internally monopropoxylated diethylenetriamine in a 4:1 ratio.
Monopropoxylated diethylenetriamine (150 g), palladium on carbon (8.02 g) and water (100 g) were charged to a 1 liter stainless steel autoclave reactor. The reactor was sealed and purged three times with nitrogen, and then three times with hydrogen. The reactor was heated to 80° C. under 50 psi (344.7 kPa) hydrogen. When the temperature reached 80° C., the hydrogen feed was opened bringing the pressure to 800 psi (5516 kPa). An HPLC pump was primed and attached to the reactor. The pump was used to add the Formalin® reagent (270 g, 37% formaldehyde in water) to the reactor at 3 mL/minute. When the equivalent amount of formaldehyde was added, the hydrogen uptake stopped, indicating the reaction was complete. After the reaction, water was pumped into the reactor to rinse the formaldehyde from the feed lines. The hydrogen feed was shut off and the reactor was cooled. It was then vented and purged with nitrogen. The catalyst was removed by filtering through Celite® filter aid.
Water was removed from the filtrate at atmospheric pressure. Distillation through a one foot (30.5 cm) packed column at a head temperature of 85° C. and pressure of 2 torr (0.267 kPa) afforded the product. The product is an inseparable mixture of the permethylated terminal and internal monopropoxylates in a 78:22 ratio (Me 4 DETA-PO). ##STR6##
EXAMPLE 5
A general and quantitative technique for measuring catalyst activity and selectivity was used in this example. The rate of isocyanate consumption as a function of time was measured using a formulation similar to that of Example 6, but containing monofunctional reactants. Reaction samples withdrawn at the indicated times were quenched with dibutylamine and analyzed by liquid chromatography. The catalysts were compared on an equimolar basis corresponding to a loading of 0.35 pphp DABCO® 33LV catalyst (33 wt % triethylenediamine in dipropylene glycol) in an actual foam, illustrated by Example 6.
Relative catalyst activity can be determined by comparison of the % NCO conversion data. Catalyst selectivity is defined as the ratio of the normalized amount of blowing (urea formation) to the normalized amount of gelling (urethane formation). A selectivity of 1.0 means that the normalized amounts of blowing and gelling are equal at that point in the reaction. A selectivity substantially below 1.0, for example about 0.3, is indicative of a strong gelling catalyst. A selectivity greater than 1.0 is indicative of a strong blowing catalyst. In practice, the function of the blowing catalyst is to counterbalance the activity of a strongly gelling catalyst such as triethylenediamine (TEDA). Thus in practical terms, any catalyst which exhibits a selectivity significantly higher than 0.3 can be used as a blowing catalyst to counterbalance a strong gelling catalyst such as TEDA.
The results set forth in Table 1 show that significant differences in blow to gel selectivity are observed with these new catalysts. Moving the hydroxyl group further from the central nitrogen improves the blowing selectivity, especially in the early stages of the reaction. This type of structural sensitivity has not been previously observed and is unexpected.
TABLE 1__________________________________________________________________________ Time (min)Catalyst 0.5 1.0 1.5 2.0 3.0 4.0 5.0 6.0 7.0 8.0__________________________________________________________________________TMHPDETA Conversion 12.1 25.1 34.9 45.5 58.3 67.7 74.1 84.7 89.7 91.5(n = 1) Selectivity 0.64 0.68 0.71 0.73 0.75 0.75 0.72 0.66 0.69 0.74TMHBDETA Conversion 13.3 24.7 34.9 44.1 54.5 61.7 66.4 69.6 71.8 73.4(n = 2) Selectivity 0.68 0.72 0.73 0.73 0.72 0.69 0.67 0.68 0.67 0.67TMHADETA Conversion 13.3 24.1 33.8 42.0 54.9 62.7 67.7 71.1 73.4 75.6(n = 3) Selectivity 0.80 0.83 0.84 0.82 0.81 0.78 0.76 0.74 0.74 0.73__________________________________________________________________________
EXAMPLE 6
In this example a polyurethane foam was prepared in a conventional manner. The polyurethane formulation in parts by weight was:
______________________________________COMPONENT PARTS______________________________________E-648 60E-519 40DC-5043 1.5Diethanolamine 1.49Water 3.5TDI 80 105 Index______________________________________ E-648 a conventional, ethylene oxide tipped polyether polyol marketed by Arco E519 a styreneacrylonitrile copolymer filled polyether polyol marketed b Arco DABCO DC5043 silicone surfactant marketed by Air Products and Chemicals, Inc. TDI 80 a mixture of 80 wt % 2.4 TDI and 20 wt % 2,6TDI
The foam reactivity was measured using either 0.60 g of TMHPDETA (99% purity; 2.75 mmole) or 0.73 g of TMHADETA (95% purity; 2.75 mmole) as catalyst. For each foam, the catalyst (as specified in Table 2) was added to 85.2 g of above premix in a 5" (12.7 cm) diameter by 10" (25.4 cm) tall paper can and the formulation was well mixed for 20 sec. Sufficient TDI 80 was added to make a 105 index foam [index=(mole NCO/mole active hydrogen)×100] and mixed well for 4 sec. The foam was allowed to rise freely, monitoring foam height and carbon dioxide evolution with time. Table 2 sets forth conditions and results.
TABLE 2__________________________________________________________________________ TMHPDETA TMHADETA TMHPDETA THHADETATime (sec.) CO.sub.2 evolved (g) Foam Height (mm)__________________________________________________________________________13 2.77 3.90 4.3 6.219 3.95 5.33 6.5 8.631 5.30 6.31 9.3 10.943 5.90 6.92 10.5 11.649 6.13 7.06 10.8 11.867 6.49 7.18 11.3 12.185 6.70 7.37 11.6 12.0103 6.85 7.36 11.7 12.0121 6.94 7.42 11.7 12.0139 7.00 7.43 11.8 11.9157 7.05 7.43 11.7 11.8175 7.08 7.57 11.7 11.8__________________________________________________________________________
As these data indicate, the TMHADETA foam shows more CO 2 evolution and greater volume (as indicated by foam height) than the TMHPDETA foam. This is consistent with the results given in Table 1, which show that TMHADETA has greater selectivity for blowing than TMHPDETA.
EXAMPLE 7
The relative activities of the Me 4 DETA-PO catalyst of the prior art and the pure, internally propoxylated material TMHPDETA, were compared using the procedure of Example 5. As discussed in Example 5, the relative activities of catalysts can be ascertained by comparison of their respective % NCO conversion data.
Comparison of the relative activity of Me 4 DETA-PO with that of TMHPDETA in Table 3 shows that the new, internally propoxylated material, has significantly higher activity than the prior art catalyst. Based on the teachings of the prior art, it is not expected that two isomers would have such different performance.
TABLE 3__________________________________________________________________________ Time (min)Catalyst 0.5 1.0 1.5 2.0 3.0 4.0 5.0 6.0 7.0 8.0__________________________________________________________________________Me.sub.4 DETA-PO Conversion 9.0 19.8 27.1 34.1 47.5 56.5 -- 66.4 -- 72.1Comp Ex 1 Selectivity 0.72 0.77 0.79 0.79 0.79 0.77 -- 0.76 -- 0.78TMHPDETA Conversion 12.1 25.1 34.9 45.5 58.3 67.7 74.1 84.7 89.7 91.5(n = 1) Selectivity 0.64 0.68 0.71 0.73 0.75 0.75 0.72 0.66 0.69 0.74__________________________________________________________________________ | A method for preparing a polyurethane foam which comprises reacting an organic polyisocyanate and a polyol in the presence of a blowing agent, a cell stabilizer and a catalyst composition consisting essentially of a compound of structure I ##STR1## wherein R is hydrogen, a C 1 -C 4 alkyl, C 6 -C 8 aryl, or C 7 -C 9 aralkyl group; and
n is 1 to 8 | 8 |
This is a Continuation-In-Part Application of international patent application PCT/EP2004/009707 filed Sep. 1, 2004 and claiming the priority of German Patent Application No. 103 44 426.2 filed Sep. 25, 2003.
BACKGROUND OF THE INVENTION
The invention relates to a method for operating an internal combustion engine wherein at partial engine load a lean base mixture of air and fuel is formed in the engine combustion chamber and ignited by compression ignition, and at full load a stoichiometric mixture is formed and ignited by spark ignition.
DE 195 19 663 A1 discloses a method for operating an internal combustion engine with spontaneous ignition, in which in a first stage a homogenous, pre-compressed fuel/air mix which is not suitable for spontaneous ignition is provided in the combustion chamber of the internal combustion engine, and in a second stage an additional quantity of the same fuel is injected into the working space in order to bring about the spontaneous ignition. In this case, the fuel/air mix is formed externally and introduced into the engine cylinder, where it is compressed close to the spontaneous ignition point. The injection of the additional quantity of fuel in the second stage takes place in finely atomized form, avoiding contact with wall, so as to form a mix cloud in which, on the one hand, the fuel/air ratio is no greater than the stoichiometric mixing ratio and in which, on the other hand, the spontaneous ignition is achieved.
Furthermore, DE 198 52 552 C2 discloses a method for operating a four-stroke internal combustion engine which, at part-load, forms a lean base mix from air, fuel and retained exhaust gas and, at full load, forms a stoichiometric mix. At part load, compression ignition takes place, whereas at full load spark ignition takes place. Furthermore, mechanically controlled exhaust-gas retention with switchable valve closure overlap and exhaust gas throttling is provided. An activation fuel amount may be injected into the retained exhaust gas. The quantity of retained exhaust gas, with the valve closure overlap switched on, is controlled or preset as a function of the engine speed and engine load by an exhaust-gas throttle valve which is active for all the combustion chambers. Upon opening of the intake valves of the individual cylinders the pressure in the various combustion chambers is equalized by a cylinder-selective, cycle-consistent activation injection.
A method for operating a four-stroke, reciprocating-piston internal combustion engine is also known from DE 198 18 569 C2. It is characterized by a homogenous, lean base mix of air, fuel and retained exhaust gas and by compression ignition and direct injection of the fuel into the combustion chamber. The volume of the combustion chamber changes cyclically. The combustion chamber can be filled with fresh gas through at least one intake valve, while the combustion exhaust gases can be at least partially expelled through at least one exhaust valve. In the part-load range and in the lower full-load range, the internal combustion engine is operated with compression ignition and preferably mechanically controlled exhaust-gas retention, whereas in the full-load range and high part-load range it is operated by spark ignition.
One drawback of the methods disclosed in the above-mentioned documents is in particular that the temperature of the exhaust gas and the composition of the working gas change when the engine speed changes. The reactivity, that is the ignitability of the mix during compression ignition, is likewise altered as a result even to the extent of causing misfires if the operating gas temperatures are too low.
It is therefore an object of the invention to provide a method for operating an internal combustion engine in which changes in the reactivity, that is, the ignitability of the mix in the event of changes in engine speed can be taken into account and/or corrected.
SUMMARY OF THE INVENTION
In a method for operating an internal combustion engine in which the angular locations where the fuel/air mix combustions takes place can be controlled by an adjustment of the inlet and outlet valve timing, the timing of at least one of the intake and exhaust valve opening phases is shifted depending on the engine speed so as to reduce engine emissions.
The method according to the invention is distinguished in that, with an increase in engine speed, a principle-based shift in the combustion toward early is corrected by shifting the intake and/or exhaust valve opening phases. A targeted change in the control times of this nature allows changes in the temperature of the operating gas and the operating gas composition in the event of engine speed changes to be effectively corrected.
In the event of a reduction in the engine speed, either the intake phase can be shifted toward early or the exhaust phase can be shifted toward late, or the two phase-shift procedures can be both carried out simultaneously, in which case the effects are cumulative.
The invention will become more readily apparent from the following description thereof with reference to the accompanying drawings:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a diagram showing the supply of air, 50% conversion and indicated mean effective pressure as a function of the engine speed;
FIG. 2 shows a graph illustrating the cylinder pressure and valve-lifting curve during the intermediate compression for various engine speeds;
FIG. 3 shows a graph illustrating the induction pipe pressure and the valve-lifting curve during the intermediate compression for various engine speeds;
FIG. 4 shows a diagram illustrating the combustion position as a function of intake and exhaust phase for various injection points;
FIG. 5 shows a graph illustrating the cylinder pressure in the intermediate compression as a function of the exhaust phase;
FIG. 6 shows a graph illustrating the cylinder pressure and the induction pipe pressure during the induction phase as a function of the intake phase; and
FIG. 7 shows a diagram illustrating the adjustment strategy for a change in engine speed with a constant indicated mean effective pressure.
DESCRIPTION OF THE INVENTION
A major factor behind research and development in internal combustion engines is the desire to improve fuel consumption while, at the same time, reducing emissions. In the case of spark ignited internal combustion engines, in particular alternative load control methods are recommended to increase the part-load efficiency. The most important development trends concern the stratified direct fuel injection engine, which, with the aid of quality control, moves the spark ignited internal combustion engine principle closer to the spontaneously igniting internal combustion engine principle (diesel engine). This is made possible by the variable valve gear combined with residual gas strategies, which are intended to limit charge exchange losses. Both methods theoretically promise major benefits but are thwarted in one case by the expensive after-treatment of the exhaust gas from the super-stoichiometric mix and in the other case by the limited residual gas compatibility of spark ignited internal combustion engines. The ideal is a link between these two methods: a quality-controlled internal combustion engine with high residual gas content and spontaneous ignition, which on account of homogenous combustion in super-stoichiometric operation emits very little if any nitrogen oxide.
One factor of homogeneous combustion methods is the spontaneous ignition time, which is determined by the temperature or mix composition. If the required charging temperatures are obtained with the aid of exhaut-gas retention, more specifically by means of the parameters exhaust-gas temperature and quantity, the combustion location of the cycle n is dependent on the preceding cycle (n−1); the required spontaneous ignition temperature is not reached in extreme circumstances. The combustion location for its part is the determining factor for the target variables of the internal combustion engine and therefore must have values which are defined as a function of load and engine speed.
It is the object of the present invention to provide ways of implementing changes in exhaust-gas quantity and temperature as they are required during a change of the operating point within part-load operation in which ignition combustion takes place without adversely affecting the combustion.
Exhaust-gas retention can in principle be achieved with the aid of suitable valve control times. This requires firstly early closing of the exhaust valve, in order to keep the required quantity of residual exhaust gas in the combustion chamber of the internal combustion engine. To prevent the hot exhaust gas from flowing back into the induction pipe, with ensuing cooling effects and charge losses, the opening of the intake valve is delayed. However, this concept cannot be applied to conventional spark ignited internal combustion engines without further measures.
If the valve closure overlap is made sufficiently variable, the first control concept for this form of providing the required temperature is obtained. The requirement for an independent high-pressure part and therefore optimum charging in this case, however, requires the use of a fully variable valve drive mechanism with which valve opening and closing times can be adjusted independently of one another.
With conventional camshafts the setting of a defined exhaust-gas retention rate is generally performed by the camshaft controllers which are already in widespread use. As an undesirable side-effect, with a rigid cam contour, the angle at which the valve opens changes with the angle at which the valve closes, which leads to charging and efficiency losses and not least to a restricted operating range in terms of load and engine speed.
In addition to the control of the temperature at the end of compression with the aid of the exhaust-gas retention rate or quantity, the use of the direct fuel injection and the operation of the internal combustion engine with excess air also influences the operating gas temperature and/or the mix composition of the fuel. The effect of the direct injection can in this case be divided into two mechanisms: firstly, a thermal effect, which provides an increase in the exhaust-gas temperature as a result of the conversion of the pre-injected fuel, and secondly a preconditioning of the fuel, which increases the reactivity of the latter and therefore influences the integral ignition delay.
To determine the influence of the engine speed on the compression ignition combustion, starting from a reference point of the internal combustion engine (2000 rpm and 3 bar p mi ), the engine speed is increased with otherwise constant boundary conditions.
FIG. 1 shows the air supply, the 50% conversion and the indicated mean effective pressure as a function of the engine speed. Initially, the supply of air remains undifferentiated, since the combustion chamber charge only decreases significantly at high engine speeds. The combustion position fluctuates with the variation in the air supply and ultimately shifts in the early direction at high engine speeds. The indicated mean effective pressure initially rises by the same amount by which the charge exchange work decreases, as evidenced by the indicated charge exchange mean effective pressure. Only if the combustion location is too early and therefore unfavorable in terms of efficiency does the indicated mean effective pressure drop with an increase in the engine speed.
With increasing engine speed, more exhaust gas remains in the combustion chamber, as evidenced by the rising maximum pressure in the intermediate compression that can be seen from FIG. 2 . Moreover, the lower wall heat transfer results in higher exhaust-gas temperatures.
The higher pressure level in the intermediate compression leads to a rising backflow of exhaust gas into the induction pipe when the intake valve opens. this backflow manifests itself as an increase in the induction pipe pressure, as can be seen from FIG. 3 . At the same time, a reflected excess pressure wave occurs near to the time at which the intake valve closes. Its maximum, with the engine configuration shown at an engine speed of approx. 2400 to 2500 rpm, lies precisely at the point at which the intake valve is closed and therefore leads to a dynamic recharging effect, which makes it possible to understand the profile of the air supply in FIG. 1 . The fact that the combustion is considerably affected by such events, which tend to appear unimportant during part-load operation of spark ignited internal combustion engines, is important. This needs to be taken into account when designing the air induction system.
If, at the selected reference point of 2000 rpm and 3 bar p mi and a constant injection mass, the phase positions of intake and exhaust camshaft are now altered, the effect of primary influencing parameters, such as for example the valve control times, will be immediately apparent.
FIG. 4 diagrammatically depicts the combustion location as a function of intake and exhaust phase.
Accordingly, an adjustment of the exhaust valve in the exhaust phase toward early causes a shift in the combustion location in the early direction. A retarded intake phase likewise leads to a shift in the combustion toward early to approximately the same extent. In the event of simultaneous adjustment of the phase locations, the effect is doubled.
Therefore, the control times of intake and exhaust valves should not be considered separately from one another, but rather have an influence on one another.
If the crankshaft angle-based indexing data as shown in the diagram illustrated in FIG. 5 are considered, it will be possible to explain the shift in the combustion location.
The figure illustrates the rise in the cylinder pressure during the intermediate compression with earlier closing of the exhaust valve. Because of the higher residual gas content, the gas temperature in the compression phase rises, and accordingly combustion begins earlier. However, the increase in the maximum pressure at the gas exchange dead center is relatively low compared to a shift in the closing of the exhaust valve of a fully variable valve drive. On account of the rigid cam contour, earlier closing of the exhaust valve also leads to a shift in the opening angle of the exhaust valve, cutting off the expansion. With the opening of the valves at an ever higher back pressure, already in this phase more exhaust gas flows out of the combustion chamber of the internal combustion engine. There are two limit scenarios for the shift in the intake phase, as can be seen from FIG. 6 . On the one hand, exhaust gas flows back out of the combustion chamber into the induction pipe if the intake valve opens too early. This leads to an excessive rise in pressure in the induction pipe and to a decrease in pressure in the combustion chamber. The other limit situation results from the intake valve closing too late. In this case, charge losses occur since part of the cylinder charge which has just been drawn into the cylinder is discharged, which leads to a reduction in the effective compression.
FIG. 7 diagrammatically depicts an engine speed change strategy only with the aid of the phase locations of the two camshafts, without altering the indicated mean effective pressure. The wall heat transfer per working cycle, which drops as the engine speed rises, leads to an increased temperature level in the internal combustion engine. To keep the combustion location constant, consequently, more exhaust gas can be discharged from the combustion chamber, i.e. the valve closure overlap can be reduced. The improvement in efficiency brought about by the decreasing wall heat losses has to be compensated for by a reduction in the fuel injection quantity. In this case, it is not really reasonable to keep the indicated load constant under real driving conditions by the friction mean effective pressure which rises with the engine speed. In the event of a change in engine speed, a change in the valve closure overlap can be realized by the hydraulic camshaft actuators, since this operation is relatively slow. | In a method for operating an internal combustion engine in which the angular locations where the fuel/air mix combustions takes place can be controlled by an adjustment of the inlet and outlet valve timing, the timing of at least one of the intake and exhaust valve opening phases is shifted depending on the engine speed so as to reduce engine emissions. | 5 |
PRIORITY
This application claims priority of the provisional application #60/225,975, filed Aug. 17, 2000.
FIELD OF THE INVENTION
The invention pertains to permanent magnet devices for separating stacks of sheets of ferrous steel.
BACKGROUND OF THE INVENTION
The use of fanner magnets is well known in the manufacturing arts. Fanner magnets serve to fan out or separate sheets in a stack of metal sheets, thereby facilitating the movement or transfer of sheets utilizing handling devices, such as pickups, suction cups, or other lifting or moving devices. Such magnets operate on the principle of creating repelling polarities among the individual sheets.
There are a wide variety of methods used for separating magnetic sheets. One example is found in U.S. Pat. No. 4,815,916, issued to James A. Beck, and teaching a plurality of magnetic elevator devices disposed along the sides of a vertical stack of magnetizable steel objects, such as sheets. Another type of device is found in U.S. Pat. No. 4,743,006, issued to Fred Bole, Jr., et al., and discloses a fanner magnet assembly including a power-actuated carriage for movement relative to a stack of sheets.
However, prior sheet separators are limited in their operation, and are not particularly well adapted to separating palletized sheets of metal. When placed in pallets, a stack of steel sheets (or sheets of other ferro-magnetic composition) is typically aligned and positioned between pins on a pallet to restrain the lateral movement of the stack of sheets while the pallet is being transported and processed. Typical pallets are equipped with a large number of pallet pins located around the perimeter of the pallet which surround the sheets. These pins are placed in cavities, thereby creating a “fence” of pallet pins surrounding the sheets of ferrous material. Pallet pins may be threaded into corresponding threaded cavities in a pallet, or may be mounted using “bayonet” type locking whereby the pallet pin is engaged and disengaged relatively quickly from the cavity in a pallet by placing a plurality of pallet pins completely surrounds the steel sheets, the sheets are effectively restrained from movement in relation to the pallet.
In the manufacturing environment, pallets equipped with pallet pins surrounding a stack of metal sheets are transported to the vicinity of an industrial processing machine. Typically, an external-type sheet fanner, which may be magnetic, is positioned close to the pallet to facilitate separation of the upper sheets from the stack. The uppermost sheet is then engaged by either a magnetic or suction-type gripper which will lift the uppermost sheet vertically from the stack, and free from the pallet and associated pins.
Improvements to this process can be realized by utilizing specialized magnetic pallet pins of the type described herein.
SUMMARY OF THE INVENTION
The invention is a new type of pallet pin which contains an integral rotating magnet assembly. The integral magnet assembly is mounted within an inner cylindrical cavity of the pin and is attached to an axially extending member which is coaxial with the pin's circumference. Although the magnet is of approximately the same length as the pin's cylindrical length, it occupies only a portion of the circumference defined by the interior of the cylinder.
Magnetic pallet pins of this description are substituted for traditional non-magnetic pallet pins in one or more locations around the perimeter of the pallet. The internal magnet assemblies are rotatable within the cylinder, and thereby positioned either away from or adjacent to the sheets of metal carried by the pallet. When the magnets are rotated into a position in proximity to the sheets in the stack, the sheets are temporarily magnetized such that identical magnetic polarity exists at the edges of the sheet proximate to the pallet pin. This causes the sheets to repel one another and separate, thereby facilitating their removal from the stack.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cutaway side view of the invention showing the pallet pin and its internal magnet.
FIG. 2 is an elevation view of the invention.
FIG. 2A is a close-up view of the bottom portion of the invention.
FIG. 3 is a top view of the invention.
FIG. 4 is a top view of the invention, minus the upper components, revealing the placement and orientation of the internal magnets.
FIG. 5 is a bottom view of the invention.
FIG. 6 is a perspective view of the internal components of the invention.
FIG. 7 is a perspective view, showing a typical application of the invention in relation to a pallet and associated workpieces.
FIG. 8 is a perspective view of the invention showing a hexagonal locating pin.
FIG. 9 is a perspective view of the invention showing a T-shaped locating pin.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The invention and its objects will be best understood first by reference to FIG. 1 and FIG. 4, showing the magnetic pallet pin assembly 10 consisting of a preferably stainless steel cylindrical housing 12 having a bottom plug 14 , a top bushing 16 and upper housing element 23 . All of the foregoing housing elements serve to house rotating center element 30 to which are affixed one or more magnetic elements 20 and 22 positioned along the longitudinal axis of element 30 and affixed to it by suitable means. A portion of the interior cavity 18 of housing 12 defines a space opposite the magnetic elements. Rotatable center element 30 is affixed through bushing 16 to a lifting element 24 . Center element 30 , with attached magnets 20 and 22 is rotatable relative to housing 12 by manually rotating element 24 around the central longitudinal axis of housing 12 . Such rotation of element 24 serves to reposition magnets 20 and 22 in relation to the circumference of housing 12 , permitting the operator to selectively position magnets 20 and 22 in relation to housing 12 .
Housing 12 is further provided, as shown in FIG. 2, with a fastening surface 40 and locating pin 42 adapted to engage with a cavity ( 70 ) on a corresponding pallet ( 64 ).
Rotation of the center element 30 and its associated magnets, accordingly, serves to move the magnetic elements 20 and 22 of the invention nearer or further from the metal sheets which a plurality of the pallet pins surrounds, when placed in position on a typical sheet-carrying pallet. Rotation of the center element 30 to a position in proximity to the sheets thereby serves to separate the upper sheets from the stack as the sheets become magnetized. The number of pallet pins utilized for this purpose on any pallet is regulated by the size and weight of the sheets to be separated, and the degree of separation required. It will be appreciated by those skilled in the art, however, that it is necessary to use pairs of pallet pins for each application, one such pallet pin providing a north polarity and one such pallet pin providing a south polarity.
The details of the operation of the invention can be further understood by reference to FIG. 6, which shows in perspective, element 30 , a plurality of magnetic elements 20 and secondary magnetic elements 22 . Magnetic elements 20 and 22 can be seen in top view in FIG. 4 . By utilizing progressively smaller cross sections for magnetic elements 20 and 22 , it can be seen that it is possible to place magnetic elements 22 in relatively close proximity to the side wall of cylindrical housing 12 , thereby bringing magnetic elements 22 in proximity to the sheets which will be fanned by operation of the invention. As is depicted in FIG. 6, there are preferably a plurality of primary magnetic elements 20 arrayed from the top to the bottom of rotating element 30 . A plurality of secondary magnetic elements 22 are then affixed to magnetic elements 20 . The magnetic elements 20 and 22 are oriented so as to place the north pole of magnetic elements 22 outermost, in certain assemblies 10 , while orienting all of the south poles outermost in others. This will insure that the sheet fanners, when operated in pairs, will suitably magnetize sheets to create the desired fanning affect.
The assemblies 10 formed of rotating element 30 and magnetic elements 20 and 22 is placed within the interior cavity 18 of housing 12 . Rotating element 30 is attached to upper housing element 23 , which in turn, is attached to pivot channel 25 . Rotating handle 24 , preferably circular in cross-section, is fitted into channel 25 , and is permitted to rotate within channel 25 to permit handle 24 to be folded downward out of the way during storage or operation of the system.
Typically, each pin fanner magnet assembly 10 is provided with a locating pin 42 which may be hexagonal, round or T-shaped in cross-section. As shown in FIG. 2 and FIG. 2A, the locating pin 42 is provided to engage each pin fanner assembly 10 with a cavity on a corresponding pallet. In this fashion, each assembly 10 remains securely positioned in relation to said pallet, ideally proximate to a station for the placement of sheets to be fanned.
Hexagonal and T-shaped locating pins, as shown in FIGS. 8 and 9, provide the additional advantage of being able to secure the housing of assembly 10 from rotation once the assembly 10 has been placed in position on the pallet. As shown in FIG. 5, by placing the locating pin 42 off the center axis of the assembly 10 , the assembly 10 may be rotated to a position closer to or more remote from the edge of a sheet of workpieces placed on the pallet.
To facilitate lifting, carrying and positioning of the assembly 10 , each assembly 10 is provided with a lifting handle 50 which is secured to the exterior of the cylindrical housing 12 by fasteners, welding, adhesives or other acceptable fastening means.
Also in this embodiment, upper housing element 23 is provided with a marker 48 , indicating the active position of the array of magnets 20 and 22 contained within the housing 12 . This visual indicator permits the operator to readily ascertain the position of the magnetic array in relation to both the housing 12 and the workpieces being formed.
In operation, as shown in FIG. 7, a stack 60 containing a plurality of workpieces 62 is positioned on a non-magnetic pallet 64 . A pair of magnetic pallet pin assemblies 10 are secured in cavities 70 provided on such pallet, by engagement of locating pins 42 . The internal magnetic elements and rotating element are oriented by rotating handles 24 to position the magnetic elements adjacent the edge of the workpieces 62 . The magnetic field induced in the workpieces 62 creates like polarity at the edges of said workpieces 62 adjacent to each assembly 10 , causing the workpieces to repel one another and separate. Once separated, the workpieces may be easily grasped and separated from the stack of workpieces 62 by gripping arms, suction cups, or comparable lifting devices. Further rotation of handle 24 and upper housing element 23 through an arc of 180 degrees locates the internal magnetic elements on the side of the assembly 10 opposite the workpieces 62 , resulting in the loss of the effective magnetic field affecting the workpieces 62 , and allowing the workpieces 62 to again collapse to an unseparated stack.
It will also be appreciated from examining FIG. 7, that the positioning of the stack 60 of workpieces 62 in relation to the pallet 64 is aided by one or more non-magnetic pallet pins 68 which engage cavities 70 , thereby limiting the horizontal movement of workpieces 60 in relation to stack 64 . And, although cavities 70 are depicted in FIG. 7 as cylindrical, such cavities may, in alternative embodiments, be hexagonal, T-shaped, or otherwise configured so as to perform the function of locating desired points on the outer circumference of assemblies 10 and pins 68 in relation to the edges of the stacks 60 . By providing assemblies 10 and pins 68 with locating pins 42 which are offset from the central axis of assemblies 10 and pins 68 , as shown in detail in FIG. 2A, the central longitudinal axes of assemblies 10 and pins 68 may be positioned closer to or further away from the edges of stack 60 . In this fashion, stack 60 may be restrained from horizontal movement in relationship to pallet 64 , but still be provided sufficient clearance from pins 68 and assemblies 10 to permit effective fanning action, and allow workpieces 62 to be lifted from the stack 60 . | The invention is a magnet for facilitating separation of individual sheets from a stack of ferro-magnetic sheets; the invention is in the form of an elongate housing containing an elongate array of magnets which may be selectively positioned in relation to the housing so as to bring the array in proximity to the edge of the stack of ferro-magnetic sheets, thereby inducing a magnetic field in said sheets and causing the sheets to separate, thereby facilitating manipulation of the uppermost sheet from the stack. | 1 |
This application is a divisional of application Ser. No. 11/980,343, filed Oct. 31, 2007, now U.S. Pat. No. 7,849,991, which is a divisional of application Ser. No. 11/094,870, filed Mar. 31, 2005, now abandoned, which claims priority from U.S. Provisional Patent App. No. 60/558,535 filed on Apr. 1, 2004, the disclosures of which are incorporated herein by reference and to which priority is claimed.
BACKGROUND
The present application relates to coupling devices and, more particularly, to coupling devices capable of being quickly disconnected.
Coupling devices are typically used on various types of equipment to transfer power from a first rotating shaft to a second rotating shaft. It is often desirable to disconnect a coupling such that equipment embodying the coupling may be cleaned. However, often times, it may be quite time consuming to disconnect the couplings.
Accordingly, there is a need for coupling devices that may be quickly disconnected and reconnected.
SUMMARY
A first aspect of the quick disconnect coupling includes a first hub, a shaft fixedly connected to the first hub, the shaft being non-round in cross-section, and a second hub having a non-round recess extending therethrough, the non-round recess being sized to closely receive the shaft such that the second hub is capable of sliding along the shaft and is prevented from rotating about the shaft, wherein rotation of the first hub results in corresponding rotation of the second hub.
A second aspect of the quick disconnect coupling includes a male coupling member having at least two jaws thereon, a female coupling member having at least two recesses for receiving the jaws, and a spider having at least four wings extending therefrom, the spider being shaped to be received within the female coupling member such that each of the recesses includes at least two of the wings, wherein each jaw of the male coupling member is positioned between two wings of the spider when the male coupling member is engaged with the female coupling member.
A third aspect of the quick disconnect coupling includes a drive shaft, a motor, and a coupling device for transferring rotational power from the motor to the drive shaft, the coupling device including a first hub, a non-round shaft fixedly connected to the first hub, a second hub closely and slidably received over the non-round shaft, the second hub having a recess for receiving the drive shaft, and a spring for biasing the first hub away from the second hub, wherein the first hub is connected to the motor and the second hub is selectively connectable to the drive shaft.
Other aspects of the quick disconnect coupling will be apparent from the following description, the accompanying drawings, and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a front perspective view of a first aspect of the quick disconnect coupling;
FIG. 1B is a side elevational view of the quick disconnect coupling of FIG. 1A ;
FIG. 2 is a front perspective view of the quick disconnect coupling of FIG. 1A embodied on a motor for use with a piece of equipment having a drive shaft;
FIG. 3 is an exploded perspective view of a second aspect of the quick disconnect coupling;
FIG. 4A is a front perspective view of the quick disconnect coupling of FIG. 3 in an engaged position; and
FIG. 4B is a front elevational view, in section, of the quick disconnect coupling of FIG. 4A .
DETAILED DESCRIPTION
As shown in FIGS. 1A and 1B , a first aspect of the quick disconnect coupling, generally designated 10 , includes a male hub 12 , a female hub 14 , a non-round shaft 16 , a spring 17 and a pin 22 .
The non-round shaft 16 may be attached to or integral with (i.e., shaft 16 is connected to) the male hub 12 and may include a slot 18 extending axially along the non-round shaft 16 and through a surface of the non-round shaft 16 . The non-round shaft 16 may have any shape in cross-sectional view (taken perpendicular to the axis of the shaft) other than circular, hence the designation as non-round. For example, in cross-sectional view, the non-round shaft 16 may be square, rectangular, triangular, pentagonal, hexagonal or elliptical.
The female hub 14 may include a first end 24 , a second end 36 and a non-round recess 20 extending axially through the length of the female hub 14 . The non-round recess 20 is non-round in shape, as described above, and has a shape corresponding to the shape of the non-round shaft 16 such that the non-round shaft 16 may be closely received within the non-round recess 20 . The female hub 14 may slide relative to the male hub 12 along the non-round shaft 16 and rotation of the male hub 12 (and corresponding rotation of the non-round shaft 16 ) results in rotation of the female hub 14 due to the non-round shape of the shaft 16 and recess 20 .
The spring 17 may be a coil spring and may be position coaxially over the non-round shaft 16 and between the male hub 12 and female hub 14 to bias the female hub 14 away from the male hub 12 . The pin 22 may be inserted through an opening 21 in the first end 24 of the female hub 14 such that the pin 22 engages the slot 18 in the non-round shaft 16 , thereby restricting movement of the female hub 14 relative to the male hub 12 along the shaft 16 .
As shown in FIG. 2 , the quick disconnect coupling 10 may be attached to a motor 26 for connecting the motor 26 to a drive shaft 34 of a piece of equipment 28 . The drive shaft 34 may include an end portion 42 and may be shaped to be received within the recess 20 of the female hub 14 (i.e., non-round in shape) such that rotation of the female hub 14 results in corresponding rotation of the drive shaft 34 when the drive shaft 34 is received within the recess 20 .
The motor 26 may be slideably mounted onto the piece of equipment 28 by sliding a pair of wings 32 of the piece of equipment 28 between the body of the motor 26 and flanges 30 .
The male hub 12 of the coupling 10 may be fixedly attached to the shaft (not shown) of the motor 26 . The female hub 14 may then be attached to the drive shaft 34 of the equipment 28 as follows: First, the female hub 14 is retracted against the bias of the spring 17 and toward the male hub 12 . Then, the motor 26 may be slid onto the equipment 28 as described above (i.e., via flanges 30 ). When the female hub 14 is released, thereby allowing the spring 17 to bias the female hub 14 to its forward and engaged position, the drive shaft 34 of the equipment 28 is received within the recess 20 of the female hub 14 such that power from the motor 26 may be transferred to the drive shaft 34 by rotation of the male hub 12 which results in rotation of the non-round shaft 16 which results in rotation of the female hub 14 and corresponding rotation of the drive shaft 34 .
The quick disconnect coupling 10 may be disconnected from the drive shaft 34 as follows: The female hub 14 may be retracted against the bias of the spring 17 into close proximity with the male hub 12 such that the drive shaft 34 is no longer received within the recess 20 and the second end 36 of the female hub 14 is cleared from an end portion 42 of the drive shaft 34 . The motor 26 may then be slid off of the equipment 28 .
As shown in FIGS. 3 , 4 A and 4 B, a second aspect of the quick disconnect coupling, generally designated 50 , includes a male coupling member 52 , a female coupling member 54 , a spider 56 and a connector such as a washer 58 and screw 60 assembly.
The male coupling member 52 may be generally cylindrical in shape and include a first end 71 and a second end 73 . Three jaws 62 may be spaced equidistantly about the periphery of the second end 73 and extend axially from the male coupling member 52 . Each jaw 62 may include a beveled surface 63 and be tapered to a point 65 . The first end 71 may include a recess 70 having a slot 72 therein. The recess 70 may receive a first shaft (not shown) having a notch (not shown) that engages the slot 72 for preventing rotation of the first shaft relative to the male coupling member 52 such that rotation of the first shaft results in corresponding rotation of the male coupling member 52 .
The female coupling member 54 may be generally cylindrical in shape and include a first end 80 and a second end 82 . Three recesses 64 may be spaced equidistantly about the periphery of the first end 80 for receiving the three jaws 62 of the male coupling member 52 . Each recess 64 may additionally include a secondary recess 69 for receiving the tapered point 65 of the jaw 62 . As shown in FIG. 4B , the second end 82 may include a recess 84 having a slot 86 therein. The recess 84 may receive a second shaft (not shown) having a notch (not shown) that engages the slot 86 for preventing rotation of the second shaft relative to the female coupling member 54 such that rotation of the second shaft results in corresponding rotation of the female coupling member 54 and rotation of the female coupling member 54 results in corresponding rotation of the second shaft.
As best shown in FIG. 3 , the spider 56 includes six wings 66 equidistantly spaced and extending radially from the center of the spider 56 . The spider 56 is received within the first end 80 of the female coupling member 54 such that each recess 64 receives two wings 66 of the spider 56 . The spider 56 may be made of a soft or hard polymeric material such as urethane or any other suitable rigid material.
The spider 56 may be fixedly attached to the female coupling member 54 by any suitable connector, such as a washer 58 and screw 60 assembly such that the spider 56 is fixed onto the female coupling member 54 thereby preventing the spider 56 from easily falling away from the coupling assembly 50 when the coupling assembly 50 is disconnected.
Accordingly, the male coupling member 52 may be connected to a first shaft (not shown) and the female coupling member 54 may be connected to a second shaft (not shown) and the two shafts may be coupled by engaging the male coupling member 52 with the female coupling member 54 , as shown in FIG. 4A . The spider 56 creates a tight fit between the jaws 62 and recesses 64 and allows for the transfer of rotational power between the male and female coupling members 52 , 54 even if the first and second shafts are not perfectly aligned. The beveled surface 63 and tapered point 65 of each jaw 62 guide the jaws 62 into engagement with the recesses 64 such that each jaw 62 is positioned between two wings 66 in the recess 64 and the tapered point 65 engages the secondary recess 69 . Therefore, as the male coupling member 52 rotates due to the rotation of the first shaft, the female coupling member 54 and second shaft rotate accordingly.
The coupling assembly 50 may be disconnected by withdrawing the jaws 62 of the male coupling member 52 from the recesses 64 of the female coupling member 54 . When disconnected, the spider 56 remains connected to the female coupling member 54 by the washer 58 and screw 60 assembly, thereby simplifying the disassembly process.
Although the quick disconnect coupling is shown and described with respect to certain aspects, it is obvious that modifications will occur to those skilled in the art upon reading and understanding the specification. The quick disconnect coupling includes all such modifications and is limited only by the scope of the claims. | A quick disconnect coupling including a first hub, a shaft fixedly connected to the first hub, the shaft being non-round in cross-section, and a second hub having a non-round recess extending therethrough, the non-round recess being sized to closely receive the shaft such that the second hub is capable of sliding along the shaft and is prevented from rotating about the shaft, wherein rotation of the first hub results in corresponding rotation of the second hub. | 8 |
CROSS REFERENCES TO RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Application Serial No. 60/050,230 filed Jun. 19, 1997.
FIELD OF THE INVENTION
This invention relates to polyester compositions and specifically to poly(ethylene terephthalate) (PET) copolymer compositions containing both 1,4-cyclohexanedimethanol (CHDM) and isophthalic acid (or dimethyl isophthalate). This polymer composition is useful in many applications; particularly beverage packaging applications that require improved carbon dioxide or oxygen barrier.
BACKGROUND OF THE INVENTION
It is well known in the art that PET is useful for many packaging applications. It is also very well known and practiced that PET or modified PET is the polymer of choice for making beverage and food containers, particularly carbonated beverage containers. Furthermore, it is known that PET can be modified, on a commercial scale with either CHDM or isophthalic acid (or dimethyl isophthalate).
While each comonomer has its benefits, both suffer from detriments when used alone. CHDM improves the ease of processing of the resin, but unfortunately decreases the barrier properties of the resultant container. Isophthalic acid increases the barrier of the PET, but unfortunately decreases the processing window in which acceptable containers can be formed. Accordingly, there remains a need in the art for a resin which displays improved barrier without sacrificing processability.
WO 98/02479 discloses copolyesters containing repeat units from terephthalic acid, ethylene glycol, at least 5 mole % isophthalic acid and optionally 2,6-naphthalene dicarboxylic acid. However, additional repeat units, such as CHDM are not disclosed.
SUMMARY OF THE INVENTION
The present invention relates to polyesters displaying improved barrier properties to carbon dioxide and oxygen and good processability. More specifically the present invention relates to polyesters comprising CHDM and isophthalic acid as modifying monomers. It should be understood that the use of the term isophthalic acid (or terephthalic acid) also includes simple ester derivatives such as dimethyl isophthalate or dimethyl terephthalate. The polyesters of the present invention display novel combinations of crystallization rate, barrier and absorption properties.
DETAILED DESCRIPTION OF THE INVENTION
The polymers of the present invention comprise terephthalic acid residues, CHDM residues and isophthalic acid residues. The polymers contain repeat units from the dicarboxylic acids (isophthalic and terephthalic acids) and from the glycols (ethylene glycol and CHDM). More specifically, the compositions of the present invention comprise a dicarboxylic acid component comprising isophthalic acid and terephthalic acid and a glycol component comprising ethylene glycol and CHDM wherein the molar ratio of isophthalic acid to CHDM is about 1:1 to about 20:1. Also disclosed are formed articles such as films and containers which display an O 2 permeability ratio over PET homopolymer of at least about 1.05.
The dicarboxylic acid component is comprised of at least 80 mole percent terephthalic acid and preferably at least 85 mole percent terephthalic acid and more preferably 90 mole percent terephthalic acid. The remaining part of the acid component is isophthalic acid. The diol (or glycol) component is comprised of at least 90 mole percent ethylene glycol and preferably at least 95 mole percent ethylene glycol. The remaining part of the diol component is CHDM.
The ratio of isophthalic acid to CHDM is critical for our application. The ratio of isophthalic acid to CHDM (on a mole basis) is about 1:1 to about 20:1, preferably about 1.5:1 to about 16:1 and more preferably about 2:1 to about 10:1.
The dicarboxylic acid component of the polyester may optionally be modified with up to about 15 mole percent of one or more different dicarboxylic acids. Such additional dicarboxylic acids include aromatic dicarboxylic acids preferably having 8 to 14 carbon atoms, aliphatic dicarboxylic acids preferably having 4 to 12 carbon atoms, or cycloaliphatic dicarboxylic acids preferably having 8 to 12 carbon atoms. Examples of dicarboxylic acids include phthalic acid, naphthalene-2,6-dicarboxylic acid, cyclohexanedicarboxylic acid, cyclohexanediacetic acid, diphenyl-4,4'-dicarboxylic acid, succinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, mixtures thereof and the like.
In addition, the glycol component may optionally be modified with up to about 15 mole percent, of one or more different diols other than ethylene glycol. Such additional diols include cycloaliphatic diols preferably having 6 to 20 carbon atoms or aliphatic diols preferably having 3 to 20 carbon atoms. Examples of such diols include: diethylene glycol, triethylene glycol, propane-1,3-diol, butane-1,4-diol, pentane-1,5-diol, hexane-1,6-diol, 3-methylpentanediol-(2,4), 2-methylpentanediol-(1,4), 2,2,4-trimethylpentane-diol-(1,3), 2-ethylhexanediol-(1,3), 2,2-diethylpropane-diol-(1,3), hexanediol-(1,3), 1,4-di-(hydroxyethoxy)-benzene, 2,2-bis-(4-hydroxycyclohexyl)-propane, 2,4-dihydroxy-1,1,3,3-tetramethyl-cyclobutane, 2,2-bis-(3-hydroxyethoxyphenyl)-propane, 2,2-bis-(4-hydroxypropoxyphenyl)-propane, mixtures thereof and the like. Polyesters may be prepared from two or more of the above diols.
The resin may also contain small amounts of trifunctional or tetrafunctional comonomers such as trimellitic anhydride, trimethylolpropane, pyromellitic dianhydride, pentaerythritol, and other polyester forming polyacids or polyols generally known in the art.
Also, although not required, additives normally used in polyesters may be used if desired. Such additives include, but are not limited to colorants, pigments, carbon black, glass fibers, fillers, impact modifiers, antioxidants, stabilizers, flame retardants, reheat aids, acetaldehyde reducing compounds, crystallization aids and the like.
The polyesters of the present invention are formed via conventional polyesterification. The three polymerization stages are hereinafter referred to as the esterification stage, the prepolymer stage, and the polycondensation stage. The basic conditions which define these three stages throughout the present application are set out below for convenience and clarity.
In the first stage of the melt-phase process, a mixture of polyester monomer (diglycol esters of dicarboxylic acids) and oligomers are produced by conventional, well-known processes. The ester exchange or esterification reaction is conducted at a temperature between about 220° C. to about 250° C. and a pressure of about 0 to about 20 psig in the presence of suitable ester exchange catalysts such as lithium, magnesium, calcium, manganese, cobalt and zinc, or esterification catalysts such as hydrogen or titanium suitable forms of which are generally known in the art. The catalysts can be used alone or in combination. Preferably the total amount of catalyst is less than about 100 ppm on an elemental basis. Suitable colorants may also be added at this point to control the final color of the polyester. The reaction is conducted for about 1 to about 4 hours. It should be understood that generally the lower the reaction temperature, the longer the reaction will have to be conducted.
Generally at the end of the esterification, a polycondensation catalyst is added. Suitable polycondensation catalysts include salts of titanium, gallium, germanium, tin, antimony and lead, preferably antimony or germanium or a mixture thereof. Preferably the amount of catalyst added is between about 90 and 150 ppm when germanium or antimony is used. Suitable forms such as, but not limited to antimony oxide are well known in the art. The prepolymer reaction is conducted at a temperature less than about 280° C., and preferably between about 240° C. and 280° C. at a pressure sufficient to aid in removing undesirable reaction products such as ethylene glycol. The monomer and oligomer mixture is typically produced continuously in a series of one or more reactors operating at elevated temperature and pressures at one atmosphere or greater. Alternately, the monomer and oligomer mixture could be produced in one or more batch reactors.
Next, the mixture of polyester monomer and oligomers undergoes melt-phase polycondensation to produce a low molecular weight precursor polymer. The precursor is produced in a series of one or more reactors operating at elevated temperatures. To facilitate removal of excess glycols, water, alcohols, aldehydes, and other reaction products, the polycondensation reactors are run under a vacuum or purged with an inert gas. Inert gas is any gas which does not cause unwanted reaction or product characteristics. Suitable gases include, but are not limited to CO 2 , argon, helium and nitrogen.
Temperatures for this step are generally between about 240° C. to about 280° C. and a pressure between about 0 and 2 mm Hg. Once the desired inherent viscosity is reached, the polymer is pelletized. Precursor I.V. is generally below about 0.7 to maintain good color. The target I.V. is generally selected to balance good color and minimize the amount of solid stating which is required. Inherent viscosity (I.V.) was measured at 25° C. using 0.50 grams of polymer per 100 ml of a solvent consisting of 60% by weight phenol and 40% by weight tetrachloroethane.
The materials and testing procedures for the results shown herein are as follows:
Inherent Viscosity (Ih.V.): Determined at 25° C. with a 0.50 gram sample of the polymer in 100 mL of 60/40 by weight solution of phenol/tetrachloroethane.
Polymer Composition: Determined by hydrolysis GC and 1 H-NMR.
Film Extrusion: Melt cast film was produced using a laboratory scale film line which consisted of a 1 inch Killion extruder having a single flight screw, a 6 inch wide die, and a 20 mil die opening. Similar conditions were used for all compositions. The heater zones and die were set between 260 and 270° C. with a screw RPM of about 85 which produced amperage readings between 4 and 9 and a measured melt temperature between 270 and 275° C. The nominal 20 mil film passed over a chill roll (130-150° C.) and was collected on a tubular, cardboard roll. Prior to processing, the ground polymer was dried for about 6 hours at 140° C. in a dehumidified air dryer.
T. M. Long Film Stretching: All the materials were biaxially oriented using a TM Long Film Stretcher. The materials were all stretched at 20° above the T g (second scan T g ). The materials were biaxially oriented 300% in each direction, a 4×4 stretch, simultaneously at a rate of 14 in/sec or 270%/sec. The samples were held 2 minutes at temperature prior to stretching. The samples were stored in a controlled environment, 23° C. and 50% RH, prior to stretching, and as well, were equilibrated a minimum of 14 days after extruding before stretching. The T g 's were measured within 24 hours of orienting.
Permeability Measurements: Oxygen permeability measurements were conducted using a Modem Controls (MOCON) Oxtran 10/50A permeability tester. Measurements were made at 23.0±0.1° C. Test gases were passed through water bubblers, resulting in about 75% RH. Testing was done in accordance with ASTM D 3985.
Carbon dioxide permeability measurements were using a MOCON Permatran C-IV permeability tester. Tests were run at 23.0±0.2° C. with dry gases (0% RH).
Sample thickness is required for determining permeability. In this work thickness was measured using a micrometer with 0.05 mil precision. The mean of at least five measurements around a test sample was used.
It is known that physical aging of PET films leads to an appreciable decrease in permeability. This occurs because the diffusion of gas molecules in glassy polymers is strongly dependent on the free volume present, which diminishes with age for films below T g . Immediately after being cooled below the glass transition, the physical aging rate is fairly rapid, but after roughly 10 days the rate becomes very slow. Likewise, the observed decrease in permeability occurs largely during the initial 10 days after the most recent exposure above T g . O 2 permeability reductions of 20% for extruded films and 10% for oriented films during the first 10 days have been previously observed. Beyond the initial 10 days further reductions in permeability were on the order of a few percent during the subsequent months. Since small compositional differences in permeability are of interest in this work, all samples were aged for at least 14 days after extrusion or biaxial orientation before being tested for permeability to avoid confounding compositional effects with physical aging effects.
For oriented films at least three permeability test specimens were sampled and tested for each composition. In the case of O 2 duplicate test runs were conducted on each test specimen, while for CO 2 triplicate runs were conducted to reduce test method uncertainty. For extruded films typically only one sample was tested due to the long equilibration time (only O 2 permeability was measured for extruded films, not CO 2 permeability).
For oriented films the outer 11/2" to 2" were discarded along with the 4"×4" corner corresponding to the corner of the T.M. Long apparatus with stationary clamps. This corner was found to have statistically higher permeability plus lower mechanical properties and crystallinity than the remainder of the film. A locally higher temperature in this region of the T.M. Long apparatus is a possible cause of these effects. To minimize sample-to-sample variability, this corner was excluded from the sampling. Test samples were randomly drawn from the remaining portions of several biaxially oriented films.
EXAMPLES
The following examples are meant to illustrate the present invention. All parts and percentages in the examples are on a molar basis unless otherwise stated.
Example 1
Preparation of poly(ethylene terephthalate) (PET) homopolymer
PET homopolymer was prepared by the following procedure. Dimethyl terephthalate (0.75 moles, 145.5 g), ethylene glycol (1.5 moles, 93 g) and catalyst metals were placed in a 0.5 L polymerization reactor under a nitrogen atmosphere. The mixture was heated with stirring at 200° C. for 1 hour and then 210° C. for 2 hours. The temperature was increased to 280° C., the nitrogen flow was stopped and vacuum was applied. The polymer was stirred under vacuum (0.4-0.55 mm Hg) for 1 hour and 25 minutes. The polymer was allowed to cool and ground. The I.V. was 0.702 dL/g. Several batches of similar I.V. were blended together and solid-state polymerized (as described in more detail below) for 30 minutes at 215° C. to achieve an Ih.V. of 0.73 dL/g. The ground solid-stated polymer was converted to extruded and then biaxially oriented film as described previously. Table 1 lists the permeability of the biaxially oriented films to both oxygen and carbon dioxide.
Example 2
Solid State Polymerization
Several batches with inherent viscosities within a 0.05-0.08 dL/gram range were combined and dry blended. Subsequent film extrusion processing required a minimum of 600 grams of total copolymer. The 600 gram sample was placed in a conventional glass solid stating unit, and approximately 4.0 SCFH nitrogen gas was purged through the static bed. The selection of the solid stating temperature and corresponding solvent for temperature control was based on the melting point of the copolymer. It was desirable to maintain a solid stating temperature at least 25° C. below the melting point of the copolymer to avoid pellet agglomeration. Consequently, either diethyl succinate (BP 215° C.) or ethylene glycol (BP 197° C.) were typically employed. In a previous smaller scale experiment (20 grams), samples were taken with time for each copolymer composition to generate a time versus inherent viscosity profile. This profile was used to define the solid stating time for each composition at the 600 gram scale. The I.V. specification was 0.68-0.74 dL/gram. The polymer grind was used directly in subsequent film extrusion processing.
Example 3
Evaluation of Eastapak PET 9921 (PET copolymer with 3.5% copolymerized CHDM)
Eastapak PET 9921 pellets (Ih.V=0.76 dL/g) were extruded into film and biaxially oriented as described previously. Table 1 lists the permeability of the biaxially oriented films to both oxygen and carbon dioxide.
Example 4
Preparation of PET with 1.7% CHDM and 1.5% isophthalic acid
PET copolymerized with 1.7% CHDM and 1.5% isophthalic acid was prepared by the following procedure. Dimethyl terephthalate (0.69 moles, 133.8 g), ethylene glycol (1.39 moles, 86.1 g), dimethyl isophthalate (0.0105 moles, 2.04 g), CHDM (0.011 moles, 1.60 g) and catalyst metals were placed in a 0.5 L polymerization reactor under a nitrogen atmosphere. The mixture was heated with stirring at 200° C. for 1 hour and then 210° C. for 2 hours. The temperature was increased to 280° C., the nitrogen flow was stopped and vacuum was applied. The polymer was stirred under vacuum (0.4-0.55 mm Hg) for 1 hour and 25 minutes. The polymer was allowed to cool and ground. The I.V. was 0.613 dL/g. Several batches of similar I.V. were blended together and solid-state polymerized (as described in Example 1) for 60 minutes at 215° C. to achieve an I.V. of 0.736 dL/g. The ground solid-stated polymer was converted to extruded and then biaxially oriented film as described previously. Table 1 lists the permeability of the biaxially oriented films to both oxygen and carbon dioxide.
Example 5
Preparation of PET with 1.7% CHDM and 2.9% isophthalic acid
PET copolymerized with 1.7% CHDM and 2.9% isophthalic acid was prepared by the following procedure. Dimethyl terephthalate (0.68 moles, 131.7 g), ethylene glycol (1.39 moles, 86.1 g), dimethyl isophthalate (0.021 moles, 4.07 g), CHDM (0.011 moles, 1.60 g) and catalyst metals were placed in a 0.5 L polymerization reactor under a nitrogen atmosphere. The mixture was heated with stirring at 200° C. for 1 hour and then 210° C. for 2 hours. The temperature was increased to 280° C., the nitrogen flow was stopped and vacuum was applied. The polymer was stirred under vacuum (0.4-0.55 mm Hg) for 1 hour and 25 minutes. The polymer was allowed to cool and ground. The I.V. was 0.749 dL/g. Several batches of similar I.V. were blended together and converted to extruded and then biaxially oriented film as described previously. Table 1 lists the permeability of the biaxially oriented films to both oxygen and carbon dioxide.
Example 6
Preparation of PET with 6.4% CHDM and 5.9% isophthalic acid
PET copolymerized with 6.4% CHDM and 5.9% isophthalic acid was prepared by the following procedure. Dimethyl terephthalate (0.66 moles, 126.3 g), ethylene glycol (1.39 moles, 86.1 g), dimethyl isophthalate (0.042 moles, 8.15 g), CHDM (0.045 moles, 6.48 g) and catalyst metals were placed in a 0.5 L polymerization reactor under a nitrogen atmosphere. The mixture was heated with stirring at 200° C. for 1 hour and then 210° C. for 2 hours. The temperature was increased to 280° C., the nitrogen flow was stopped and vacuum was applied. The polymer was stirred under vacuum (0.4-0.55 mm Hg) for 1 hour and 25 minutes. The polymer was allowed to cool and ground. The I.V. was 0.698 dL/g. Several batches of similar I.V. were blended together and solid-state polymerized (as described in Example 1) for 51 minutes at 200° C. to achieve an I.V. of 0.766 dL/g. The ground solid-stated polymer was converted to extruded and then biaxially oriented film as described previously. Table 1 lists the permeability of the biaxially oriented films to both oxygen and carbon dioxide.
Example 7
Preparation of PET with 3.5% CHDM and 7.6% isophthalic acid
PET copolymerized with 3.5% CHDM and 7.6% isophthalic acid was prepared by the following procedure. Dimethyl terephthalate (1.196 moles, 232.0 g), ethylene glycol (2.554 moles, 158.3 g), dimethyl isophthalate (0.104 moles, 20.2 g), CHDM (0.045 moles, 6.6 g) and catalyst metals were placed in a 1.0 L polymerization reactor under a nitrogen atmosphere. The mixture was heated with stirring at 190° C. for 1 hour and then 210° C. for 2 hours. The temperature was increased to 280° C., the nitrogen flow was stopped and vacuum was applied. The polymer was stirred under vacuum (0.4-0.55 mm Hg) for 1 hour and 5 minutes. The polymer was allowed to cool and ground. The I.V. was 0.636 dL/g. Several batches of similar I.V. were blended together and solid-state polymerized (as described in Example 1) for 2 hours at 197° C. to achieve an I.V. of 0.737 dL/g. The ground solid-stated polymer was converted to extruded and then biaxially oriented film as described previously. Table 1 lists the permeability of the biaxially oriented films to both oxygen and carbon dioxide.
TABLE 1______________________________________Ex % # I % CHDM I/CHDM CO.sub.2.sup.a XPETCO.sub.2.sup.b O2.sup.c XPETO.sub.2 .sup.d______________________________________1 0 0 0 30.13 1.0 4.54 1 2 0 3.5 0 33.49 0.9 5.13 0.89 3 1.5 1.7 0.88 31.49 0.96 4.73 0.96 4 2.9 1.7 1.71 25.53 1.06 4.62 0.98 5 5.9 6.4 0.92 30.55 0.99 4.93 0.92 6 7.6 3.5 2.17 28.7 1.05 4.2 1.08______________________________________ .sup.a CO.sub.2 permeability. cc*mil/100 in.sup.2 *24 hrs.*atm. .sup.b ratio of permeability of sample over permeability of PET homopolymer (Ex. 1). .sup.c O.sub.2 permeability. cc*mil/100 in.sup.2 *24 hrs.*atm. .sup.d ratio of permeability of sample over permeability of PET homopolymer (Ex. 1).
It can be clearly seen (Example 2) that when the only modifying comonomer is CHDM, the permeability of the polymer is higher (and the barrier lower) than that of PET homopolymer. By adding an amount of isophthalic acid within the ranges of the present invention (Examples 4 and 6), the permeability of the polymer is lowered (and hence the barrier to oxygen and carbon dioxide is raised). Examples 3 and 5 clearly show that the ratio of isophthalic acid to CHDM must be greater than about 1:1 to display the desired improvement of the present invention. | This invention relates to PET copolymer composition that have both 1,4-cyclohexanedimethal (CHDM) and isophthalic acid moieties copolymerized. These compositions have better oxygen and carbon dioxide barrier properties than either PET homopolymer or CHDM-modified PET copolymers. These copolymer compositions are useful for packaging applications (such as carbonated soft drink bottles) requiring barrier properties to oxygen and carbon dioxide at least as good or better than PET homopolymer. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of provisional application Ser. No. 60/771,535, filed Feb. 8, 2006, the entire contents of which are incorporated herein by reference.
BACKGROUND
[0002] The invention relates generally to an enhanced performance connector and in particular, to a connector including a plug and outlet designed for enhanced performance.
[0003] Improvements in telecommunications systems have resulted in the ability to transmit voice and/or data signals along transmission lines at increasingly higher frequencies. Several industry standards that specify multiple performance levels of twisted-pair cabling components have been established. The primary references, considered by many to be the international benchmarks for commercially based telecommunications components and installations, are standards ANSI/TIA/EIA-568-A (/568) Commercial Building Telecommunications Cabling Standard and ISO/IEC 11801 (/11801), generic cabling for customer premises. For example, Category 3, 4 and 5 cable and connecting hardware are specified in both /568 and /11801, as well as other national and regional specifications. In these specifications, transmission requirements for Category 3 components are specified up to 16 MHz. Transmission requirements for Category 4 components are specified up to 20 MHz. Transmission requirements for Category 5 components are specified up to 100 MHz. The above referenced transmission requirements also specify limits on near-end crosstalk (NEXT).
[0004] Often, telecommunications connectors are organized in sets of pairs, typically made up of a tip and ring connector. As telecommunications connectors are reduced in size, adjacent pairs are placed closer to each other creating crosstalk between adjacent pairs. To comply with the near-end crosstalk requirements, a variety of techniques are used in the art.
[0005] Compensation for the modular jacks and plugs has been added using external elements such as a PCB, flex circuits, discreet components (i.e. resistors, capacitors). These previous methods add cost and complexity. As the bandwidth requirements increase due to higher signaling rates, such as 10GBASE-T Ethernet and beyond, components need to be improved.
[0006] While there exist plugs and outlets designed to reduce crosstalk and enhance performance, it is understood in the art that improved plugs and outlets are needed to meet increasing transmission rates.
SUMMARY
[0007] An embodiment of the invention is a telecommunications outlet including a contact carrier and a plurality of contacts supported on the contact carrier, the contacts corresponding to tip and ring pairs, at least one of the contacts having a characteristic to improve signal transmission performance by providing internal compensation to balance signals by controlling resistive, inductive or capacitive characteristics along the contacts.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a front view of an outlet in embodiments of the invention.
[0009] FIG. 2 is a perspective view of a contact carrier of FIG. 1 .
[0010] FIG. 3 is a side view of the contact carrier of FIG. 2 .
[0011] FIG. 4 is a front view of an outlet in alternate embodiments of the invention.
[0012] FIG. 5 is a perspective view of a contact carrier of FIG. 4 .
[0013] FIG. 6 is a side view of the contact carrier of FIG. 5 .
[0014] FIG. 7 is a front view of an outlet in alternate embodiments of the invention.
[0015] FIG. 8 is a bottom view of the outlet of FIG. 7 .
[0016] FIG. 9 illustrates contacts within the outlet of FIG. 7 .
[0017] FIG. 10 is a perspective view of an outlet in alternate embodiments of the invention.
[0018] FIG. 11 is a cross-sectional view of a plug mating with the outlet of FIG. 10 .
[0019] FIG. 12 is a perspective view of the contact carrier of FIG. 10 on a circuit board.
[0020] FIG. 13 is a perspective view a contact carrier in alternate embodiments.
[0021] FIG. 14 is a perspective, partial cut-away view of a plug in embodiments of the invention.
[0022] FIG. 15 is a top view of the plug of FIG. 13 .
DETAILED DESCRIPTION
[0023] FIG. 1 is a front view of an outlet 100 in embodiments of the invention. As known in the art, the outlet includes eight contacts 102 . It is understood that the number of contacts may vary depending on application, and embodiments of the invention are not limited to eight contacts. As is known in the art, contacts are referred to as being in eight positions 1 - 8 , from one side of the outlet to the other. The contacts may be arranged in tip and ring pairs as is known in the art with, contacts 1 / 2 , 3 / 6 , 4 / 5 and 7 / 8 defining tip and ring pairs. Embodiments of the invention are described with reference to contacts in different positions.
[0024] FIG. 2 is a perspective view of a contact carrier 104 of FIG. 1 , depicting the first contact as 102 1 . In this embodiment crosstalk is reduced by altering features of the contacts 102 . One feature is the length of the contacts. In FIG. 2 , contacts in positions 3 and 6 are shorter than the other contacts. Thus, contacts 3 and 6 do not extend as far in the mating region 106 above the top surface of contact carrier 104 where contacts from a plug make electrical contact with contacts 102 . Another feature is the angle of the contact with respect to an axis X parallel to the top surface of the contact carrier. Contacts in positions 4 , 6 and 8 are at a first angle (e.g., 20.5 degrees) with reference to axis X. Other contacts in positions 2 , 5 and 7 are at a second angle (e.g., 12 degrees) with reference to axis X. Another feature is the inclusion of a bend in the contact, such that the angle of the contact with reference to axis X decreases at the bend. As shown in FIGS. 2 and 3 , contact in position 1 has a bend towards axis X.
[0025] This arrangement of the contacts improves signal transmission performance by providing internal compensation to balance signals by adjusting the contacts to maximize resistive, inductive, capacitive characteristics (including signal phase delay) along contacts 102 . For example, adjusting the length, adding bends, adjusting the spacing of the contacts is performed to compensate for crosstalk within the outlet. Further, the cross sectional size of the contacts, the cross sectional shape of the contacts and/or the conductivity of the material used in one or more of the contacts may be varied to alter resistive, inductive, capacitive characteristics (including signal phase delay) of contacts 102 .
[0026] FIG. 4 is a front view of an outlet 200 in embodiments of the invention. As known in the art, the outlet includes eight contacts 202 . It is understood that the number of contacts may vary depending on application, and embodiments of the invention are not limited to eight contacts. As is known in the art, contacts are referred to as being in eight positions 1 - 8 , from one side of the outlet to the other. The contacts may be arranged in tip and ring pairs as is known in the art with, contacts 1 / 2 , 3 / 6 , 4 / 5 and 7 / 8 defining tip and ling pairs.
[0027] Embodiments of the invention are described with reference to contacts in different positions. FIG. 5 is a perspective view of a contact carrier 204 of FIG. 4 , depicting the first contact as 202 1 . In this embodiment crosstalk is reduced by altering features of the contacts 202 . One feature is the length of the contacts. In FIG. 5 , contacts in positions 3 and 6 are shorter than the other contacts. Thus, contacts 3 and 6 do not extend as far in the mating region 206 above the top surface of contact carrier 104 where contacts from a plug make electrical contact with contacts 102 . Another feature is the angle of the contact with respect to an axis X parallel to the top surface of the contact carrier. As shown in FIG. 6 , contacts in positions 4 , 6 and 8 are at a first angle (e.g., 20.5 degrees) with reference to axis X. Other contacts in positions 1 , 2 , 3 , 5 and 7 are at a second angle (e.g., 12 degrees) with reference to axis X.
[0028] This arrangement of the contacts improves signal transmission performance by providing internal compensation to balance signals by adjusting the contacts to maximize resistive, inductive, capacitive characteristics (including signal phase delay) along contacts 202 . For example, adjusting the length, adding bends, adjusting the spacing of the contacts is performed to compensate for crosstalk within the outlet. Further, the cross sectional size of the contacts, the cross sectional shape of the contacts and/or the conductivity of the material used in one or more of the contacts may be varied to alter resistive, inductive, capacitive characteristics (including signal phase delay) of contacts 202 .
[0029] FIG. 7 is a front view of an outlet 300 in alternate embodiments of the invention. As known in the art, the outlet includes eight contacts 302 . It is understood that the number of contacts may vary depending on application, and embodiments of the invention are not limited to eight contacts. As is known in the art, contacts are referred to as being in eight positions 1 - 8 , from one side of the outlet to the other. The contacts may be arranged in tip and ring pairs as is known in the art with, contacts 1 / 2 , 3 / 6 , 4 / 5 and 7 / 8 defining tip and ring pairs. Embodiments of the invention are described with reference to contacts in different positions.
[0030] FIG. 8 is a bottom view of the outlet of FIG. 7 . As shown in FIG. 8 , contacts in positions 4 and 5 are moved to be closer together along axis Y than other adjacent contacts. The axis Y is parallel to the side of the outlet 300 and extends parallel to the 8 contacts 302 . FIG. 9 illustrates contacts within the outlet of FIG. 7 . As shown in FIG. 9 , contacts 302 in positions 3 and 6 are moved back relative to the remaining contacts towards a rear wall 306 of outlet 300 . Further, contacts 302 in positions 3 and 6 are moved upwards relative to the remaining contacts towards a top wall 308 of the outlet 300 . The positioning of contacts 302 may be varied to alter resistive, inductive, capacitive characteristics (including signal phase delay) of contacts 302 . Further, the cross sectional size of the contacts, the cross sectional shape of the contacts and/or the conductivity of the material used in the contacts may be varied to alter resistive, inductive, capacitive characteristics (including signal phase delay) of contacts 202 .
[0031] FIG. 10 is a perspective view of an outlet 400 in embodiments of the invention. As known in the art, the outlet includes eight contacts 402 . It is understood that the number of contacts may vary depending on application, and embodiments of the invention are not limited to eight contacts. As is known in the art, contacts are referred to as being in eight positions 1 - 8 , from one side of the outlet to the other. The contacts may be arranged in tip and ring pairs as is known in the art with, contacts 1 / 2 , 3 / 6 , 4 / 5 and 7 / 8 defining tip and ring pairs.
[0032] Embodiments of the invention are described with reference to contacts in different positions. As shown in FIG. 10 , all contacts 402 have a bend that directs the contact towards axis X ( FIG. 11 ). Contacts 402 in positions 4 , 6 and 8 are have a higher angle with reference to axis X than contacts 402 in positions 1 - 3 , 5 and 7 which have a smaller angle with reference to axis X. Axis X is parallel to the top surface of contact carrier 404 . FIG. 11 is a cross-sectional view of a plug 406 mating with outlet 400 . The bends in the contacts 402 permit the contacts 402 to maintain consistent physical and electrical contact with contacts 408 in plug 406 in mating region 426 above top surface of the contact carrier 404 . The bends also provide a uniform displacement of the contacts 402 when plugs having different dimensions are mated with outlet 400 . Accordingly, in the mated state, the contacts 402 are in predicted positions regardless of the size of the plug 406 or insertion depth of the plug 406 into outlet 400 . This allows for control of crosstalk between contacts 402 as the location of the contacts in the mated state does not vary. FIG. 12 is a perspective view of the contact carrier 404 of FIG. 10 on a circuit board 410 .
[0033] This arrangement of the contacts improves signal transmission performance by providing internal compensation to balance signals by adjusting the contacts to maximize resistive, inductive, capacitive characteristics (including signal phase delay) along contacts 402 . For example, adjusting the length, adding bends, adjusting the spacing of the contacts is performed to compensate for crosstalk within the outlet. Further, the cross sectional size of the contacts, the cross sectional shape of the contacts and/or the conductivity of the material used in one or more of the contacts may be varied to alter resistive, inductive, capacitive characteristics (including signal phase delay) of contacts 402 .
[0034] FIG. 13 is a perspective view of an exemplary termination of wires to an outlet in embodiments of the invention. FIG. 13 depicts an exemplary connector housing 701 , patch cord 700 and twisted pair cable 707 . Cable 707 includes four twisted pairs of wires 708 . It is understood that embodiments of the invention may be used with cables having a different color code and the invention is not limited to cables having four twisted pairs of wires. The patch cord 700 includes a plug housing dimensioned to mate with existing modular outlets. The plug housing may be an RJ-45 type plug, but may have different configurations.
[0035] Connector 701 contains a substrate 703 which establishes an electrical connection between the jack assembly 702 and termination block 705 . Wire termination connections 704 (e.g., insulation displacement contacts) are positioned in the termination block 105 . The substrate 703 may be a printed circuit board, flexible circuit material, etc. having traces therein for establishing electrical connection between the jack assembly 702 contacts and termination block 705 termination connections 704 . Termination block 705 may be a S310 block available from The Siemon Company. Substrate 703 may include compensation elements for tuning electrical performance of the plug 100 (e.g., NEXT, FEXT). In alternate embodiments, the jack assembly contacts 702 and IDC connections 704 are part of a lead frame, eliminating the need for substrate 703 .
[0036] The jack assembly 702 includes a contact carrier with contacts 720 . The contacts 720 may use one or more of the geometries described above with reference to FIGS. 1-12 to improve signal transmission performance by providing internal compensation to balance signals by adjusting the contacts to maximize resistive, inductive, capacitive characteristics (including signal phase delay) along contacts 720 .
[0037] For example, adjusting the length, adding bends, adjusting the spacing of th-e contacts is performed to compensate for crosstalk within the outlet. Further, the cross sectional size of the contacts, the cross sectional shape of the contacts and/or the conductivity of the material used in one or more of the contacts may be varied to alter resistive, inductive, capacitive characteristics (including signal phase delay) of contacts 720 . The contacts 720 extend from the rear wall of the contact carrier rather than the bottom (as shown in FIGS. 1-12 ), but still may include similar features to improve signal transmission performance.
[0038] FIG. 14 is a perspective, partial cut-away view of a plug 500 in embodiments of the invention. Plug 500 includes a plug housing 501 and plug contacts 502 arranged in eight positions across the plug 500 . Contacts 502 include an insulation displacement portion 503 for making electrical contact with individual wires as known in the art. The plug contacts 502 engage contacts in the outlets discussed above with reference to FIGS. 1-13 . As shown in FIG. 14 , the contacts 502 include extension 504 . The extensions form increased surface area for the contacts and overlap in order to alter capacitive and/or inductive (e.g., reactive) interaction between contacts 502 . In FIG. 14 , contacts in positions 1 , 3 , 6 and 8 include extensions 504 to increase capacitive coupling between contacts 1 and 3 and contacts 6 and 8 , respectively. It is understood that other contacts may include extensions and embodiments of the invention are not limited to FIG. 14 . FIG. 15 is a top view of the plug of FIG. 14 . In alternate embodiments, the contacts 502 include openings to alter capacitive and/or inductive (e.g., reactive) interaction between contacts 502 . The openings may be formed uniformly across all contacts 502 , or may be formed in a subset of contacts 502 .
[0039] The embodiments of the invention discussed above improve the transmission performance (both signal and noise characteristics) of the RJ45 jack and/or plug by adding internal compensation within the components. The various wire forms adjust the magnitude and phase of the signals within the jack and this compensation improves overall signal integrity of the component.
[0040] 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. | A telecommunications outlet including a contact carrier and a plurality of contacts supported on the contact carrier, the contacts corresponding to tip and ring pairs, at least one of the contacts having a characteristic to improves signal transmission performance by providing internal compensation to balance signals by controlling resistive, inductive or capacitive characteristics along the contacts. | 7 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] 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
[0002] 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
[0003] 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.
[0004] 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
[0005] 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.
[0006] 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.
[0007] 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
[0008] FIG. 1 is a schematic partial cross sectional view of an embodiment of a wellhead assembly having an automated vent system.
[0009] FIG. 2 is a schematic side sectional view of a vent valve in, a closed position.
[0010] FIG. 3 illustrates the vent valve of FIG. 2 in a open position.
DETAILED DESCRIPTION OF THE INVENTION
[0011] 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 .
[0012] 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 .
[0013] 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 .
[0014] 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
[0015] 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
[0016] 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 .
[0017] 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 .
[0018] 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 .
[0019] 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.
[0020] 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.
[0021] 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 maybe 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.
[0022] 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 .
[0023] 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. | 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. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a shed forming mechanism and to a weaving loom equipped with such a mechanism.
2. Brief Description of the Related Art
In a Jacquard type weaving loom, a shed forming mechanism selectively lifts heddles, each comprising an eye in which a warp yarn passes, this yarn being located, as a function of the position of a hook to which the upper end of the heddle is fixed, above or below a weft yarn displaced by the loom. Such a known mechanism, for example disclosed by EP-A-0 219 437, comprises, inter alia, mobile hooks each provided with a lateral catch capable of cooperating with knives animated by vertical reciprocating movements in phase opposition. Each mobile hook is provided with a curved end allowing it to be immobilized by cooperation of shapes with a retaining lever.
Each mobile hook is also provided with an elastic tongue in one piece with the hook and intended to control the displacement of the retaining lever. Such a tongue is subjected to repeated, relatively intense efforts likely to induce permanent deformation by creeping, and even rupture thereof. In that case, the shed obtained presents “faults”.
It is a particular object of the present invention to overcome these drawbacks by proposing a shed forming mechanism of which the mobile hooks are robust and dimensioned precisely, this ensuring reliable operation of the loom, while they are compact in height, i.e. parallel to their direction of displacement. This makes it possible to create a compact mechanism, hence a saving of space and improved economic performances.
SUMMARY OF THE INVENTION
To that end, the invention relates to a shed forming mechanism on a weaving loom of a Jacquard type, this mechanism comprising mobile hooks, each displaced by a knife, between a position of top dead center, wherein each hook may be immobilized by a selection device, and a position of bottom dead center, and wherein each hook includes a body provided with a catch abuts with the afore-mentioned knife. This mechanism is characterized in that each hook further comprises a metal blade intended to interact with the selection device and fixed on the body in such a manner that the blade is relatively movable with respect to portions of the body adjacent the area of the catch.
Thanks to the invention, the two-part nature of the mobile hooks, of which the body is advantageously made of synthetic material, makes it possible to benefit from the robustness of the body for the mechanical link between the hook and the knife, while the geometry of the metal blade is defined with high precision, this rendering the interactions between the mobile hook and the selection device highly reliable. As the metal blade is fixed on the body in the lower part when the hook is in configuration of operation of the mechanism, the flexibility of the blade, over substantially the whole of its height, may be used for the transverse displacement of its part more particularly intended to come into engagement with a corresponding part of the selection device. The fact that a relative clearance is possible between the blade and the body of the hook may come from the suppleness of the blade and/or from that of the body.
According to advantageous, but non-obligatory aspects of the invention, this mechanism incorporates one or more of the characteristics of the dependent Claims.
In particular, the electromagnet of the selection device may be molded in one of the sides of a box for receiving and for guiding the mobile hook in translation. Such molding induces a precise positioning of the electromagnet with respect to the other functional parts of the device, such as the pins of the retaining levers, the stops and the bearings of these levers, as well as grooves for guiding the mobile hooks. Due to this high precision, the amplitudes of the movements of the mobile parts may be reduced, particularly concerning the oscillation of the retaining levers and the bending of the blades of the mobile hooks. This also contributes to the compactness of the mechanism.
The invention also relates to a weaving loom equipped with a shed forming mechanism as described hereinabove.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be more readily understood and other advantages thereof will appear more clearly on reading the following description of three forms of embodiment of a shed forming mechanism in accordance with its principle, given solely by way of example and made with reference to the accompanying drawings, in which:
FIG. 1 schematically shows a weaving loom of Jacquard type incorporating the invention.
FIG. 2 is a longitudinal section on a larger scale of the shed forming mechanism of the loom of FIG. 1 .
FIGS. 2A and 2B are partial sections respectively along lines A—A and B—B in FIG. 2 .
FIG. 3 is a view on a larger scale of a mobile hook and a part of a retaining lever of the mechanism of FIG. 2 .
FIG. 4 is a view in the direction of arrow IV in FIG. 3 .
FIG. 5 is a view similar to FIG. 2 for a mechanism in accordance with a second form of embodiment of the invention.
FIG. 6 is a partial longitudinal section through a mechanism in accordance with a third form of embodiment, and
FIG. 6A is a partial section along line A—A in FIG. 6 .
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring now to the drawings, FIG. 1 shows a weaving loom M in which a lap of warp yarns 1 comes from a beam 2 . Each warp yarn 1 passes in the eye 3 a of a heddle 3 intended to open the shed to allow the passage of a pick with a view to constituting the fabric which is wound on a reel 4 . Only two heddles 3 and 3 ′ are shown in FIG. 1 , heddle 3 being in upper position, while heddle 3 ′ is in lower position. The lower end of each heddle is connected to the frame of the weaving loom by an extension spring 5 , while its upper end is fast with harness cords 6 .
A shed forming mechanism 7 associated with an electronic control unit 8 makes it possible to lift the harness cords 6 more or less against a return effort exerted by the springs 5 . As shown solely for the harness cord associated with the heddle 3 , each harness cord has one end 6 a fast with a box 10 of the mechanism 7 , this harness cord passing in a pulley block 11 suspended from a cord 12 of which the two ends are respectively fast with two mobile hooks 13 intended to be selectively lifted by knives 14 animated by a vertical oscillatory movement in phase opposition, as represented by arrows F 2 .
Only a part of the elements constituting the shed forming mechanism has been shown in FIG. 1 in order to render the drawing clearer.
As is more particularly visible in FIGS. 2 to 4 , each hook 13 is formed by a body 20 of plastic material, in the lower end 201 of which is molded an end 12 a of the cord 12 .
The body 20 forms a single catch 202 which extends laterally with respect to a principal longitudinal axis X–X′ of the body 20 . This catch 202 is intended to come into abutment on the upper surface 14 a of a knife 14 . The hook 13 may thus be regularly lifted by a single knife 14 .
Taking into account its constituent material, the body 20 presents a certain suppleness, allowing it to adapt itself to a possible defect of position or of parallelism of the respective paths of this body and of the knife 14 associated therewith. This possibility of elastic deformation of the body 20 is represented by the double arrow F 20 in FIG. 2 . In practice, the suppleness of the body 20 makes it possible to obtain a self-positioning of the catch 202 on the knife 14 .
The hook 13 also comprises a metallic blade 21 partially molded in the body 20 . In practice, the blade 21 comprises a part 211 molded in a zone 203 of the body 20 , located near its lower end 201 , i.e. below the part 204 of the body 20 from which the catch 202 extends laterally.
The part 211 is open downwardly, this allowing the passage of the end 12 a of the cord 12 which may therefore be molded in the body 20 over a relatively great length L 12 .
The blade 21 extends over a length L 21 , above its part 211 , this length being relatively great with respect to the total length L′ 21 of the blade 21 .
The blade 21 comprises two lateral uprights 212 and 212 ′ defining therebetween a window 213 in which is housed the major part of the body 20 .
The uprights 212 and 212 ′ extend beyond the window 213 as far as a curved end 214 . The uprights 212 and 212 ′ are connected by a crosspiece 215 which separates the window 213 from an opening 216 made between parts 212 , 212 ′, 214 and 215 of the blade 21 .
Taking into account how they are mounted, the elements 20 and 21 are secured in the lower part of the hook 13 , while that part of the blade 21 which extends over the length L 21 above the zone 203 of the body 20 , is capable of lateral movements, as represented by the double arrow F 3 in FIG. 3 . These lateral movements F 3 correspond, in fact, to a relative clearance of the blade 21 with respect to the body 20 .
The mechanism 7 also comprises an electromagnet 15 molded in a part of the box 10 . This molding ensures a precise positioning of the electromagnet 15 with respect to the box 10 and to the elements that it supports or guides.
The box 10 comprises two fixed pins 10 a on which are pivotally mounted two retaining levers 16 intended to cooperate respectively with the two mobile hooks 13 connected to the two ends of the same cord 12 .
Each lever 16 comprises a metallic armature 30 provided with a cylindrical bore 301 of circular cross-section adapted to the outer diameter of a pin 10 a , with the result that the armature 30 may be mounted about a pin 10 a with the possibility of pivoting, as represented by the double arrows F 4 in FIG. 2 . The bore 301 of each armature 30 is made in an end 302 of this armature.
At its opposite end 303 , the armature 30 is in a body 31 made of an material, such as synthetic material and, more specifically, a material. The body 31 forms a catch 311 for retaining a mobile hook 13 in the vicinity of its position of top dead center. The body 31 is also provided with a heel 312 for centering with respect to a spring 32 exerting on the body 31 an effort or force F 5 tending to cause the lever 16 to pivot towards the outside of the box 10 . This effort tends to cause the catch 311 to penetrate in the opening 216 of the blade 21 of an adjacent mobile hook, which makes it possible to retain such a mobile hook in an upper position.
The metallic armature 30 of a lever 16 makes it possible to control its pivoting thanks to the electromagnet 15 , a lever 16 being able to be displaced by the curved end 214 of a blade 21 and possibly maintained in position against the effort F 5 when the electromagnet 15 is activated.
The body 31 allows an efficient interaction, without metal/metal contact, of a retaining lever 16 with a mobile hook 13 .
The levers 16 are each provided with a deflector 161 projecting with respect to their principal part 16 a in the direction of the median axis X 10 –X′ 10 of the box 10 , between its pivot axis 10 a and a zone Z 1 in which the armature 30 can come into abutment against the electromagnet 15 . A second deflector 162 is provided between the zone Z 1 and the adjacent hook 13 . The deflectors 161 and 162 are mobile with the lever 16 , inside grooves 101 and 102 made in the body 10 , which allows them to isolate the zone Z 1 which thus forms a closed chamber protected against pollution, particularly the flock likely to be transported by a hook 13 .
Taking into account the positioning of the pins 10 a on the box 10 and the geometry of the levers 16 , these levers extend solely downwardly from these fixed pins, which gives the mechanism 7 an improved compactness with respect to the mechanisms in which the lever extends on either side of its pivot axis, as described for example in EP-A-0 219 437.
Furthermore, the uprights 212 and 212 ′ of the blade 21 of a hook 13 slide in grooves 10 b made over the height of the box 10 , as shown in FIG. 2 where the cords 12 have been shown partially so that the grooves 10 b are visible. In this way, guiding of a lever 13 with respect to the box 10 is effected precisely and with minimum wear. As is shown in FIGS. 2A and 2B , each groove 10 b of the box 10 is defined by two ribs 10 f and 10 f ′ between which it extends, this allowing an efficient guiding of the upright 212 or 212 ′ that it receives. Each rib presents this shape of the bottom of the box 10 approximately as far as the location of the upper convex part of the catch 202 to the right in FIG. 2 where the rib 10 f ′ is eliminated, while the rib 10 f extends upwardly. The elimination of the outer edge 10 f ′ of the groove, i.e. the fact that it is open towards the outside of the box in the vicinity of the retaining lever 16 , allows the outward clearance of the blade 21 , in the direction of arrow F 7 in FIG. 2B , when the blade 21 comes into abutment against the adjacent lever 16 , as shown to the left in FIG. 2 , in order to exert an effort of levelling F 6 .
In practice, the bending of the blade 21 takes place at that part of the box 10 where the groove 10 b has no outer edge, this part extending over a height H, between the position of the top of the catch 202 to the right in FIG. 2 and the zone of interaction between the blade 21 and the lever 16 during levelling.
According to a variant of the invention (not shown), it is possible for the rib 10 f ′ which forms the outer edge of the groove 10 b not to be eliminated over the height H but to deviate from the rib 10 f in order to leave the blade 21 a sufficient clearance space.
In the form of embodiment shown and in the afore-mentioned variant, the widening or opening of the groove 10 b towards the outside in the vicinity of the elements 15 and 16 aims at allowing the bending of the blade 21 in this zone.
In accordance with the technical teaching of FR-A-2 752 246, a stop 40 , elastically urged by a spring 41 , is mounted between the paths of slide or movement of two mobile hooks 13 , in abutment on studs 10 c of the box 10 . This elastic stop 40 is intended to cooperate with a heel 205 made in the vicinity of the end 201 of each body 20 . Taking into account the respective positioning of the elements 205 and 40 , this interaction takes place when each mobile hook 13 arrives in the vicinity of its position of top dead center. This arrangement makes it possible to essentially overcome the forces of inertia and of friction of the mobile hooks, this facilitating reversal of movement and allowing the dimensioning of the harness and the mechanical drive elements, such as the knives 14 or the return springs 5 , to be optimised.
The curved end 214 of the blade 21 is also dimensioned so that it can come into abutment and exert an effort F 6 against a ramp 313 formed by the body 31 of each lever 16 . This momentary abutment of a hook 13 on a lever 16 allows the lever 16 to be levelled, i.e. made to abut on the electromagnet 15 , with elastic pre-loading due to the bending of the blade 21 which performs the function of the elastic tongue described in EP-A-0 219 437. The blade 21 therefore performs a function of levelling.
In the second form of embodiment of the invention shown in FIG. 5 , elements similar to those of the first embodiment bear identical references. As previously, knives 14 make it possible selectively to displace mobile hooks 13 each comprising a body 20 made of synthetic material and an elastic metal blade 21 which essentially extends above the zone where it is fixed to this body. Retaining levers 16 are associated with an electromagnet 15 .
In this embodiment, the levers 16 are mounted to pivot about pins 10 a fixed with respect to a box 10 . The technical teaching of EP-A-0 577 524 is applied here, insofar as the box 10 comprises partitions 10 d making it possible to isolate the electromagnet 15 from the ambient atmosphere. Each lever 16 is mounted to pivot on a corresponding pin 10 a , as represented by the double arrow F 4 and comprises an armature 30 which extends on either side of the pin 10 a on which it is mounted. More precisely, each armature 30 comprises a first arm 304 which extends upwardly from a central part 305 in which is made a circular bore 301 for receiving the pin 10 a . The arm 304 is intended to interact with the electromagnet 15 during its activation. The armature 30 also comprises an arm 306 which extends opposite the arm 304 with respect to the part 305 . This arm 306 is molded in a body 31 made of plastic material which forms a catch 311 intended to interact with an opening 216 of the blade 21 of a hook 13 . The body 31 also forms a ramp 313 for levelling the position of the lever 16 used during an interaction with the curved upper end 214 of a blade 21 . The blade 21 in that case exerts on the lever 16 an effort F 6 of displacement of the armature 30 towards the electromagnet 15 .
In order to isolate the electromagnet 15 efficiently, the partitions 10 d of the box 10 are provided with O-rings 10 e disposed in the vicinity of the outer surface 305 a , cylindrical with circular base, of the part 305 . In this way, independently of the orientation of a lever 16 about the axis 10 a , a satisfactory seal can be ensured.
In a variant embodiment, the partitions 10 d may be provided with reduced clearance with respect to the surface 305 a , the seals 10 e in that case being able to be eliminated, as the ends of the partitions 10 d then constitute means for seal against dust.
In the third form of embodiment shown in FIG. 6 , elements similar to those of the first embodiment bear identical references. As previously, hooks 13 each comprise a body 20 made of plastic material as well as a metal blade 21 , these elements being molded in one another in the lower part of the body 20 . A movement of relative clearance F 3 is possible between the body 20 and the blade 21 of each hook. The blade 21 of each hook may be retained in position by a catch 311 formed by a body 31 of a retaining lever 16 mounted to pivot about a pin 10 a formed by a box 10 .
Each lever 16 comprises a metal armature 30 that interacts with an electromagnet 15 at a zone Z 1 in which the armature 30 may come into abutment against the electromagnet 15 against an elastic effort or force exerted by a spring 32 centered on a heel 312 of the body 31 .
As in the first form of embodiment, a deflector 161 is provided on each lever 16 , between the armature 30 and the pin 10 a while a second deflector 162 is provided between the armature 30 and that part of the body 31 intended to interact with the blade 21 of a hook 13 . The deflector 162 of this third embodiment may move inside a groove 102 made in the box 10 between the positions respectively shown to the left and to the right of FIG. 6 . This deflector 162 projects with respect to the principal part 16 a of the lever 16 both in the direction of the median axis X 10 –X′ 0 of the box 10 and opposed thereto, with the result that the circulation of flock or of dust is prevented both between the lever 16 and the electromagnet 15 and between the lever 16 and the outer web 10 g of the box 10 .
In addition, and as is more particularly visible in FIG. 6A , the deflector 162 also projects perpendicularly to the plane of FIG. 6 with respect to the principal part 16 a of the lever 16 , this also avoiding pollution rising in the direction of the armature 30 .
Whatever the form of embodiment in question, the elastic blade 21 efficiently performs the functions of selection and of levelling, while it is not in contact with the adjacent knife 14 , the function of direct interaction with the knife devolving on the catch 202 of the body 20 . In the same way, the body 20 , through which the effort of traction exerted by the knife 14 transits, does not enter directly into contact with the selection device which comprises the elements 15 and 16 .
The characteristics of the different forms of embodiment described may be combined within the framework of the present invention.
The invention relates to two-position shed forming mechanisms used for weaving so-called “flat” fabrics, unlike three-position mechanisms used for carpets and velvets. However, the invention can be used within the scope of associating two-position mechanisms allowing a three- or four-position shed to be obtained, as described for example in EP-B-0 399 930 or FR-B-2 715 666. | Hooks for controlling movement of heddle cords in a Jacquard weaving loom are each displaced by a knife, between a position of top dead center, wherein each hook may be immobilized by a selection device, and a position of bottom dead center. Each hook includes a body provided with a catch that engages a corresponding knife and a metal blade that is relatively movable with respect to portions of the body adjacent the catch and that interacts with the selection device to selectively retain the hook in the top dead position thereof. | 3 |
PRIOR APPLICATION
[0001] This application is a divisional patent application of U.S. national phase application Ser. No. 10/498,470 filed 10 Jun. 2004 that is based on International Application No. PCT/SE02/002330, filed 16 Dec. 2002, claiming priority from Swedish Patent Application No. 0104272-0, filed 17 Dec. 2001.
FIELD OF INVENTION
[0002] The present invention concerns a method and an arrangement for impregnating chips during the manufacture of chemical pulp.
BACKGROUND INFORMATION
[0003] During the cooking of chemical cellulose pulp with continuous digesters it has been conventional to use a pre-treatment arrangement with a chip bin, steaming vessel and an impregnating chip chute, before the cooking process is established in the digester. Steaming has been carried out in one or several steps in the chip bin, prior to the subsequent formation of a slurry of the chips in an impregnation fluid or a transport fluid. The steaming has been considered to be absolutely necessary in order to be certain of expelling the air and water that is bound in the chips, such that the impregnation fluid can fully penetrate the chips, and such that air is not drawn into the system.
[0004] For example, U.S. Pat. No. 3,330,088 demonstrates the principle of such a system with a chip bin and a subsequent steaming vessel.
[0005] A great deal of development has taken place in order to optimise the steaming processing the chip bin, of which CA1154622, U.S. Pat. No. 6,199,299 and U.S. Pat. No. 6,284,095 only constitute examples of such development.
[0006] Attempts have been made to integrate the chip bin with the impregnation vessel in order to obtain in this manner a simpler system.
[0007] Already in U.S. Pat. No. 2,803,540, a system was revealed in which the chips from a chip bin were fed to a vessel in which a combined steaming and impregnation was achieved. In this vessel, the chips were steamed at the upper part of the vessel and impregnation fluid at the same temperature was added at various levels in the vessel.
[0008] These principles were applied in a process known as “Mumin cooking”, which is described in “Continuous Pulping Processes”, Technical Association of the Pulp and Paper Industry, 1970, Sven Rydholm, page 144. In this process, unsteamed chips were passed to a combined impregnation vessel, where steaming was obtained in the upper part, and to which impregnation fluid was added at a point in the upper part of the vessel during forced circulation. The impregnation fluid was in this case carried exclusively in the same direction of flow as the chips.
[0009] A system is shown in U.S. Pat. No. 5,635,025 in which the chips are fed without prior steaming to a vessel in the form of a combined chip bin, impregnation vessel and chip chute.
[0010] Steaming of the chips takes place here, the chips lying above the fluid level, and a simple addition of impregnation fluid takes place in the lower part of the vessel.
[0011] A further such system is revealed in U.S. Pat. No. 6,280,567, in which the chips are fed without prior steaming to an atmospheric impregnation vessel in which the chips are heated by the addition of warm black liquor that maintains a temperature around 130-140° C. The black liquor at high temperature is added just below the fluid level and is subjected to a reduction of pressure up through the bed of chips, after which foul-smelling released gases are removed from the top of the vessel. This creates large volumes of foul-smelling gases, which must be handled and destroyed in special systems. In this case, the impregnation fluid passes strictly in a concurrent flow direction, that is, impregnation fluid and chips move in a downwards direction.
[0012] An alternative system is revealed by SE,A,9802879-8, in which pressurised black liquor is added to the upper part of the steaming vessel, whereby the black liquor after being subjected to a pressure reduction releases steam for the steaming process. In this case, excess fluid, black liquor, can be drawn off from the lower part of the vessel.
[0013] The prior art has mostly exploited steaming as a major part of the heating of the chips, in which the steam that is used is either constituted by fresh steam or by steam flashed off from pressurised black liquor obtained from the cooking process. This involves a relatively large flow of steam, and its associated consumption of energy, and it requires a steaming system that can be regulated. The steaming has also involved the generation of large amounts of foul-smelling gases, and, at certain concentrations, a serious risk of explosion.
[0014] Problems arise when handling these volatile and readily condensed gases, which, for example, are constituted by turpentine and other hydrocarbons.
[0015] Special systems for handling these waste gases are required, and these must be dimensioned to cope with the volumes generated. Expensive systems with high capacity are required when these waste gases are created in large volumes.
THE OBJECT AND PURPOSE OF THE INVENTION
[0016] The principle object of the invention is to obtain an improved arrangement for the impregnation and heating of unsteamed chips, which arrangement does not demonstrate the disadvantages that are associated with other known solutions as described above.
[0017] A second object is to enable that the major part of the heating of the chips is made with impregnation fluid, a process that hereafter will be referred to as “fluid steaming” in which it is possible to obtain a natural reduction in temperature of the impregnation fluid by the establishment of an upper counterflow zone since the cold chips are progressively warmed by direct heat exchange during their downwards sinking motion in the vessel. In this way, it is possible in one preferred embodiment to balance the counterflow in this upper zone such that a suitable temperature is obtained in the upper part of the fluid zone, this temperature preferably being sufficiently low to prevent an extensive flashing of steam upwards through the bed of chips. This reduces the amount of foul-smelling gases released, these being to a large extent bound to the withdrawn impregnation fluid. A direct heat exchange with the cold sinking chips is obtained in the counterflow that is being considered, which is the reason that the impregnation fluid that is withdrawn can be maintained at such a low temperature that the volatile gases that are otherwise expelled can be retained in solution in the colder impregnation fluid, and finally withdrawn to a major degree together with the impregnation fluid.
[0018] A further object is to make it possible to control the heating process more accurately by the use of impregnation fluids with increasing temperatures at different positions down through the impregnation vessel, whereby the risk of steam blowing through the bed of chips is eliminated, while it is at the same time possible to obtain a high final temperature of the chips when in slurry form. This fluid steaming, which is thus established over a large section of the impregnation vessel, has surprisingly proved to expel the major part of the air and inert gases that are bound in the chips. In particular, when cooking eucalyptus and other easily cooked wood raw materials, and in cases when the chips maintain a temperature that is in excess of normal ambient temperature, i.e. over 20° C., the steaming operation using externally applied steam can be completely omitted.
[0019] In certain operational situations, such as the use of cold chips during the winter, light steaming may be necessary in order to raise the temperature of the chips to the normal value of 20-30° C., but with a severely reduced requirement for steaming compared with that needed by previously known technology.
[0020] A requirement for a certain degree of steaming may arise when using material that requires more cooking, such as softwood, with a high content of turpentine, etc., but this is severely reduced compared with that needed by previously known technology, and thus represents a major reduction in the volume of waste gases generated.
[0021] It was also an advantage if a withdrawal strainer was used, with which an efficient separation of not only foul-smelling gases but also impregnation fluid could be achieved. Much of the foul-smelling gases are bound to the withdrawn impregnation fluid when using the wet-steaming technology that is under consideration.
[0022] The invention can advantageously be used when cooking eucalyptus, bagasse and other annual plants, and it can also be used in association with the cooking of coniferous and deciduous pulp.
DESCRIPTION OF DRAWINGS
[0023] FIG. 1 shows an impregnation vessel according to the invention;
[0024] FIG. 2 shows schematically the temperature profile in the impregnation vessel;
[0025] FIG. 3 shows a used withdrawal strainer;
[0026] FIG. 4 shows the establishment of a counterflow in the upper zone.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0027] An arrangement for the impregnation of chips during the manufacture of chemical pulp is shown in FIG. 1 . The arrangement comprises an essentially cylindrical impregnation vessel 30 arranged vertically into which unsteamed chips are continuously fed into the top of the impregnation vessel via feed means, in the form of a small chip bin 1 without steaming and a chute feed (chip feed) 2 . The chips that are fed into the impregnation vessel are thus unheated chips that normally have the same temperature as the ambient temperature ±5° C.
[0028] The pressure in the vessel can be adjusted as necessary through a control valve 31 arranged in a valve line 4 at the top of the impregnation vessel, possibly also in combination with control of the steam ST via input lines 5 . When atmospheric pressure is to be established, this valve line can open out directly to the atmosphere. It is preferable that a pressure is established at the level of atmospheric pressure, or a slight deficit pressure by the outlet 4 of magnitude −0.5 bar (−50 kPa), or a slight excess pressure of magnitude up to 0.5 bar (50 kPa). Input of a ventilating flow, SW_AIR (sweep air), can be applied at the top as necessary, which ensures the removal of any gases present.
[0029] The impregnated chips are continuously output via output means, here in the form of an outlet 10 , possibly also in combination with bottom scrapers (not shown in the drawing), at the bottom of the impregnation vessel 30 .
[0030] According to the invention, a first input line 7 a with impregnation fluid BL 1 is connected to the impregnation vessel at a first height P 1 on the impregnation vessel corresponding to distance H 1 below the strainer 6 , which height is arranged under a maximum level LIQ_LEV of the chips in the impregnation vessel. The temperature of the impregnation fluid BL 1 is adjusted by temperature-regulation means 32 to a first temperature before its addition at this first height, in this case a shunt circuit with cooled and with uncooled impregnation fluid. Furthermore, at least one other input line 7 b with impregnation fluid is connected to the impregnation vessel at a second height, P 2 , corresponding to distance H 1 +H 2 below the strainer 6 , which second height is arranged under the first height P 1 on the impregnation vessel. The temperature of the impregnation fluid is adjusted by temperature-regulation means 32 to a second temperature before its addition at this second height. This second temperature exceeds the first temperature by at least 5° C.
[0031] A withdrawal strainer 6 is arranged in the wall of the impregnation vessel 30 at a height above the first height, whereby a maximum liquid level LIQ_LEV can be established in the impregnation vessel under the highest level CH_LEV of the chips in the impregnation vessel. Control of the level occurs by adjusting the balance between the addition of impregnation fluid BL 1 , BL 2 , (BL 3 ) through the input lines 7 a, 7 b, ( 7 c ) and the current withdrawal REC through the withdrawal strainer 6 and output from the bottom 10 . The liquid level must thus be established such that it lies under the highest level CH-LEV of the chips in the impregnation vessel. The level CH_LEV of the chips above the level LIQ_LEV of the liquid must be at least 2 metres and preferably at least 5 metres when impregnating eucalyptus. In the case of wood raw material of lower density, for example, softwood, which has a density that is up to 30% lower, a corresponding increase in the height of the column of chips over the surface of the fluid is established. This height is important in order to provide an optimal passage of the chips in a column.
[0032] Since the outlet 6 for impregnation fluid is located at a position in the impregnation vessel that lies above the position for addition of the first impregnation fluid BL 1 , a flow in the opposite direction to the sinking motion of the chips is established, indicated by lightly drawn upwards-pointing arrows in FIG. 1 , in at least the upper part of the fluid-filled zone Z 1 in the impregnation vessel 30 .
[0033] It is appropriate that the temperature of the first impregnation fluid BL 1 , the first temperature, lies within the interval 105±5° C., and it is appropriate that addition of the first impregnation fluid takes place through a first input line 7 a under a liquid level LIQ_LEV that has been established by added impregnation fluid in the impregnation vessel 30 at a position in the impregnation vessel at which the ambient pressure corresponds to or exceeds the saturation pressure, which corresponds at a temperature of 105° C. to a level at least 2 metres under the established liquid level LIQ_LEV if the impregnation vessel is not subject to an externally applied pressure.
[0034] The temperature of the second impregnation fluid BL 2 , the second temperature, lies within the interval 120±10° C. and addition of the second impregnation fluid through the second input line 7 b occurs under the position of addition in the impregnation vessel of the first input line, and at a position in the impregnation vessel at which the ambient pressure corresponds to or exceeds the saturation pressure, which corresponds at a temperature of 125° C. to a level at least 13 metres under the established liquid level LIQ_LEV if the impregnation vessel is not subject to an externally applied pressure.
[0035] It is advantageous if at least one third input line 7 c with impregnation fluid is connected to the impregnation vessel at a third height, P 3 , corresponding to distance H 1 +H 2 +H 3 under the strainer 6 , which third height is arranged under the second height P 2 on the impregnation vessel. The temperature of the impregnation fluid is adjusted by temperature-regulation means 32 to a third temperature before its addition at this third height. This third temperature exceeds the second temperature by at least 5° C.
[0036] The temperature of the third impregnation fluid BL 3 , the third temperature, lies within the interval 130±15° C. Addition of the third impregnation fluid occurs through the third input line 7 c under the position of addition in the impregnation vessel of the second input line, and at a position in the impregnation vessel at which the ambient pressure corresponds to or exceeds the saturation pressure, which corresponds at a temperature of 130° C. to a level at least 17 metres under the established liquid level LIQ_LEV if the impregnation vessel is not subject to an externally applied pressure.
[0037] It is preferable that the added impregnation fluid is obtained from a common flow of withdrawn black liquor BL, preferably a withdrawal of black liquor directly from a subsequent digester or via a pressurised impregnation stage. It is appropriate if this withdrawn black liquor BL is constituted by a non-pressurised withdrawal flow direct from the digester, or from a pressurised impregnation stage.
[0038] FIG. 1 shows that the first, second and third impregnation fluids, BL 1 , BL 2 and BL 3 , are to a major degree established from a common flow BL of black liquor that has been withdrawn from a subsequent cooking stage. It is appropriate if this flow is constituted by more than 50%, preferably more than 75%, of black liquor from the digester.
[0039] Temperature control of the different temperature levels is obtained by the use of a shunt circuit 32 . This controls the common original flow BL in such a manner that the first impregnation fluid BL 1 is set to the first temperature by cooling means 20 . The cooling means may be an indirect heat exchanger, a pressure drop cyclone or another form of evaporative cooling, or the addition of cold fluid, preferably colder process fluids, basic or washing filtrate.
[0040] The third impregnation fluid BL 3 can be obtained directly from the common flow BL of black liquor at the existing temperature of the black liquor. If this temperature is initially too high, cooling of the common flow BL can, naturally, take place first.
[0041] The temperature of the second impregnation fluid BL 2 is set by the mixing by means of mixing means, suitably by simple flow regulation in the shunt circuit 32 in a known manner, of the cooled flow BL 1 and the non-cooled sub-flow BL 3 of black liquor.
[0042] Even though steaming is not required for readily cooked pulps such as eucalyptus and annual plants, at a normal outdoor around 20° C., addition of extra steam ST can take place through addition means 5 arranged in the wall of the impregnation vessel, or through central pipes, above the fluid level LIQ_LEV established by the impregnation fluid.
[0043] Through the arrangement according to the invention using fluid steaming, it is possible to apply a method for the impregnation of chips during the manufacture of chemical pulp in which the chips, without preceding steaming with steam, are continuously fed into the top of an impregnation vessel, in which a pressure, at essentially the same pressure as atmospheric pressure, ±0.5 bar, is established at the top, and from which impregnated chips are continuously fed out from the bottom of the vessel. The chips are subsequently warmed in an upper fluid-filled zone Z 1 of the impregnation vessel by the addition of a first impregnation fluid BL 1 at a first temperature. The chips are subsequently warmed in a second fluid-filled zone Z 2 , under the upper zone, by the addition of at least one second impregnation fluid BL 2 at a second temperature that exceeds the first temperature by at least 5° C. A flow of impregnation fluid in the direction opposite to the sinking motion of the chips is established in at least the upper zone Z 1 of the impregnation vessel by the establishment in the impregnation vessel of a fluid level LIQ_LEV through the addition and withdrawal of impregnation fluid, where the fluid level lies below the maximum level CH_LEV reached by the chips in the impregnation vessel, and by the withdrawal REC of impregnation fluid taking place at a position in the impregnation vessel above the location of addition of the first impregnation fluid.
[0044] A better and more accurately controlled heating of the chips can be achieved with this method, during simultaneous impregnation with successively warmer impregnation fluids.
[0045] The first temperature of BL 1 is adjusted such that the temperature appropriately exceeds 100° C., preferably within the interval 100-110° C., and addition of the first impregnation fluid takes place under a fluid level in the impregnation vessel that has been established by the added impregnation fluid at a position in the impregnation vessel at which the ambient pressure corresponds to or exceeds the saturation pressure. The second temperature of BL 2 exceeds 110° C., preferably within the interval 110-130° C., and addition of the second impregnation fluid takes place under the position of addition of the first impregnation fluid in the impregnation vessel, and at a position in the impregnation vessel at which the ambient pressure corresponds to or exceeds the saturation pressure. In one preferred embodiment, shown in the drawing, the chips are heated in a third fluid-filled zone Z 3 under the second zone by the addition of a third impregnation fluid BL 3 at a third temperature that exceeds the second temperature by at least 5 ° C. The third temperature is adjusted to exceed 115° C., preferably within the interval 115-145° C., and addition of the third impregnation fluid takes place under the position of addition of the second impregnation fluid in the impregnation vessel, and at a position in the impregnation vessel at which the ambient pressure corresponds to or exceeds the saturation pressure.
[0046] An impregnation vessel that is at least 25 metres high, preferably 30-50 metres high, is used in one implementation of the method.
[0047] The upper part of the impregnation vessel above the strainer 6 , the height of the chips H 0 together with the empty volume above, can correspond to at least 6 metres (3+3 metres), and a more advantageous approximately 8 metres (5 metres chip height+3 metres empty volume, buffer volume). Impregnation fluids with progressively increasing temperatures are added according to the invention at increasing distances below the strainer 6 and below the established fluid level LIQ_LEV.
[0048] With atmospheric pressure, approximately 100 kPa (1 bar), at the top of the impregnation vessel, the first impregnation fluid having the lowest temperature, a temperature, however, that must exceed 100 degrees, is added at a position at which the hydrostatic pressure from the column of fluid that lies above it corresponds to or exceeds the saturation pressure.
[0049] At a temperature of BL 1 of 105° C., this corresponds to a saturation pressure of 120.8 kPa, that is, a fluid column of just over 2 metres height. Thus the line 7 a must open at a location more than 2 metres below the fluid level LIQ_LEV that has been established.
[0050] At a temperature of BL 2 of 125° C., this corresponds to a saturation pressure of 232.1 kPa, that is, a fluid column of just over 13 metres height. Thus the line 7 b must open at a location more than 13 metres below the fluid level LIQ_LEV that has been established.
[0051] At a temperature of BL 3 of 130° C., this corresponds to a saturation pressure of 270.1 kPa, that is, a fluid column of approximately 17 metres height. Thus the line 7 c must open at a location more than 17 metres below the fluid level LIQ_LEV that has been established.
[0052] Naturally, more or fewer additions of impregnation fluids can take place through the impregnation vessel. However, according to the invention, these must always be added such that pressure reduction does not take place, with its associated risk of steam blowing through up through the column of chips, which can disturb the passage of chips and generate foul-smelling gases that are expelled from the chips and are not bound in the withdrawn impregnation fluid REC.
[0053] The following table gives suitable positions for the addition of different impregnation fluids at different temperatures, at atmospheric pressure or at a pressure of ±0.5 bar at the top of the impregnation vessel.
Height under Height Height Temperature fluid level, under under of Saturation with atm fluid level, fluid level, impregnation pressure pressure with +50 with −50 fluid kPa at top kPa at top kPa at top 105° C. 120.8 >2 metre — >7 metre 110° C. 143.3 >4.3 metre — >9.3 metre 115° C. 169.1 >6.9 metre >1.9 metre >11.9 metre 120° C. 198.5 >9.8 metre >4.8 metre >14.8 metre 125° C. 232.1 >13.2 metre >8.2 metre >18.2 metre 130° C. 270.1 >17.0 metre >12 metre >23 metre 135° C. 313.0 >23.3 metre >18.3 metre >28.3 metre 140° C. 361.3 >26.1 metre >21.1 metre >31.1 metre 145° C. 415.4 >31.5 metre >26.5 metre
[0054] The first, second and third impregnation fluids, BL 1 , Bl 2 and BL 3 are in the method according to the invention principally established from one common flow of black liquor that has been withdrawn from a subsequent cooking stage. It is appropriate that the black liquor, which already has a high temperature when withdrawn form the digester, constitutes more than 50% and preferably more than 75% of the impregnation fluid. Energy can be managed in this way in an efficient manner.
[0055] The relevant subflows BL 1 , BL 2 and BL 3 with different temperatures are obtained in that the common flow BL is divided into at least two flows: one cooled flow and one non-cooled flow. The temperature of the first impregnation fluid BL 1 is adjusted by cooling the black liquor BL. The third impregnation fluid BL 3 is obtained directly from the common flow of black liquor. The temperature of the second impregnation fluid BL 2 is adjusted by mixing the cooled flow and the non-cooled flow of black liquor.
[0056] When impregnation primarily easily cooked types of wood, such as eucalyptus and other annual plants, steaming can be essentially avoided. Steam is thus not added to the chips that lie on top of the fluid level established by the impregnation fluid during normal steady-sate operation. The invention can also be applied even if coniferous and deciduous wood (softwood and hardwood) are used as raw material, giving a markedly reduced need for steaming, that is, a reduced addition of steam.
[0057] When treating primarily wood raw material that is difficult to cook, coniferous and deciduous wood, and in operational cases with extremely low temperature of the chips, (such as during the winter), the chips that lie above the fluid level established by the impregnation fluid can be heated by the addition to the impregnation vessel of external steam such that a temperature of the chips of at least 20° C. and of 80° C. at the most is obtained on the chips before the chips reach the fluid level that has been established by the impregnation fluid.
[0058] FIG. 2 shows schematically the temperature profile in the impregnation vessel during the use of an arrangement equivalent to that shown in FIG. 1 , when operating conditions are advantageous. The reduced energy supply that is required to raise the temperature by steaming from a low chip temperature to the standard value of 30° C. is shown in the drawing as the diagonally shaded area. This case is based on chips with a moisture content around 35%, a temperature of approximately 30° C. and a production amount of 1500 ADMT/day. In this case, an input of 0.68 tonne/tonne of wood moisture is obtained, that is, 0.68 tonnes of wood moisture per tonne of chips accompanies the chips.
[0059] The arrangement can be adjusted such that the temperature of the impregnation fluid REC that is withdrawn lies around 30° C. The following standard amounts and temperatures apply in these operational conditions:
[0060] BL 1 : 105° C., and a flow of 2.85 tonne/hour
[0061] BL 2 : 125° C., and a flow of 1.5 tonne/hour
[0062] BL 3 : 132° C., and a flow of 1.5 tonne/hour
[0063] REC: 30° C., and a flow of 0.96 tonne/tonne (i.e. 0.96 tonne fluid per tonne of chips).
[0064] A temperature of the mixture of approximately 117° C. is obtained under these conditions, which, together with the exothermic reaction with the black liquor, which corresponds to a temperature rise of approximately 5° C., ensures a final temperature of approximately 122° C. of the chips when fed out from the impregnation vessel.
[0065] At this level of the flow in the counterflow zone Z 1 , which preferably lies within the interval 50-150% of the flow of chips, calculated as a weight percentage, i.e. that 0.50-1.50 tonnes of fluid per tonne of chips is withdrawn at the flow REC, a first heating of the chips is obtained in direct heat exchange between the chips and the counterflow of impregnation fluid, which means that the temperature of the impregnation fluid is gradually reduced up through the zone Z 1 from its value of 105° C. down to 30° C. By adjusting the withdrawal flow, or by adjusting the cooling (in the heat exchanger 20 ), the withdrawal temperature can be maintained essentially constant at such a low value that the impregnation fluid does not cause evaporation of the volatile components of the chips, and/or the black liquor, and instead binds these in the impregnation fluid, with these components being successively withdrawn through the withdrawal flow REC.
[0066] FIG. 3 shows an advantageous design of the withdrawal strainer 6 , which can be used in association with the fluid steaming system according to the invention. The withdrawal strainer 6 withdraws impregnation fluid from a fluid steaming arrangement according to FIG. 1 , but is here arranged in the wall of the vessel directly prior to an increase in diameter of the vessel in a conventional manner. The unsteamed chips lie above the fluid level LIQ_LEV in the form of columns of chips with a predetermined height. The fluid level LIQ_LEV is established with the aid of a level sensor 63 that controls the evacuation pump 62 in the lower outlet. The region behind the withdrawal strainer 6 external to the column of chips is divided into an upper and a lower region, whereby a first evacuation channel is connected, via a pump or ejector 61 , to the upper part of the region, and a second evacuation channel is connected, via a pump 62 , to the lower part of the region, for evacuation of volatile gases (and/or foam 65 ) and impregnation fluid in the different evacuation channels. An unlinking plate 64 can be mounted in order to prevent that part of the column of chips that has not yet reached the fluid level from being subjected to too great a deficit of pressure. It is also possible for the pump 62 to drive an ejector 61 such that the fluid that is withdrawn via the pump 62 carries foam and gases with it.
[0067] FIG. 4 shows how a counterflow of impregnation fluid can be established by the addition of the first impregnation fluid BL 1 . If a lower temperature of around 100° C. is used for the first impregnation fluid BL 1 , the addition can take place directly under the established fluid level LIQ_LEV, with the subsequent withdrawal radially external to the level of addition P 1 . In this case it is important to establish at least one radial flow BL 1 , with a vertical component of flow BL 1 V and a horizontal component of flow BL 1 H . It is preferable that the ratio of BL 1 V to BL 1 H is maintained above a minimum value 1:10 if the temperature lies around 100° C. and under atmospheric conditions in an impregnation vessel with a diameter of 6 metres. At an increased temperature around 105° C. and under atmospheric conditions in an impregnation vessel of diameter 6 metres, the ratio of BL 1 V :BL 1 H can correspond to 2:3.
[0068] The invention can be modified in a number of ways within the framework of the attached claims. Considerably more than 2-3 impregnation fluids of different temperatures can be added at different heights in the impregnation vessel, either through central pipes (that open out in the centre of the column of chips) or through inlet nozzles in the wall of the vessel. In the same manner, several locations of addition (different heights) of impregnation fluid at the same temperature can be used, in particular in the lower part of the impregnation vessel.
[0069] Withdrawal strainers in addition to that shown in FIG. 1 , strainer 6 , can be used in the lower part of the impregnation vessel. This is particularly true if very high fluid/woods ratios are established in the impregnation vessel, and if the fluid/wood ratio is to be reduced in the outlet or if another fluid is to replace the impregnation fluid in association with the output. The impregnation fluids BL 1 , BL 2 and BL 3 can also be established from totally separate sources, that is, not from one common flow BL of black liquor. For example, BL 1 may be a wash filtrate, obtained, for example, from the washing zone of the digester, while BL 2 /BL 3 may be impregnation fluid obtained from the cooking circuits of the digester.
[0070] The impregnation fluids can also be provided with a basic supplement with the object of establishing alkali profiles that are necessary for the process, in particular if the residual alkali in the black liquor is low. A rapid initial consumption of alkali normally takes place, while it is desired to keep the final withdrawal REC low. This is the reason that progressively increasing supplements of alkali can be added to the impregnation fluids as the chips successively sink downwards through the impregnation vessel.
[0071] It is appropriate if the flow REC withdrawn from the impregnation vessel is carried directly to evaporation/recycling.
[0072] It is also possible that more than one counterflow zone can be established in the upper fluid-filled part of the impregnation vessel.
[0073] An additional supplement of colder impregnation fluid, in the region 60-90° C., may also be added at the top of the fluid-filled counterflow zone. This fluid at a lower temperature can be added continuously or it can be added as required.
[0074] While the present invention has been described in accordance with preferred compositions and embodiments, it is to be understood that certain substitutions and alterations may be made thereto without departing from the spirit and scope of the following claims. | The method and an arrangement are for improved impregnation of chips in association with the manufacture of chemical cellulose pulp. Un-steamed chips are fed into an impregnation vessel ( 30 ) in which a fluid level (LIQ_LEV) is established under the highest level (CH_LEV) of the chips. An improved impregnation arrangement for the chips is obtained by the addition of impregnation fluids (BL 1 /BL 2 /BL 3 ) with increasing temperatures at different heights (P 1, P 2, P 3 ), and by the establishment of a counter-flow zone (Z 1 ) in the uppermost part of the impregnation vessel. The requirement for steaming may in this way be dramatically reduced while at the same time the amount of expelled waste gases may be minimized. A major part of the volatile compounds present in the wood are bound to the impregnation fluid (REC) that is withdrawn. | 3 |
TECHNICAL FIELD
[0001] The invention relates generally to gas turbine engines and more particularly, to an improved twin air source gas turbine pressurizing air system.
BACKGROUND OF THE ART
[0002] Pressurizing air systems within gas turbine engines provide bleed air under pressure for many purposes including supplying auxiliary power, cooling air, etc. A pressurizing air system may extract bleed air from a compressor of the engine at more than one stage thereof to obtain air flows having different temperatures and pressures, in order to meet requirements for different purposes within the engine. However, for gas turbine engine operations the bleed airflow changes in both temperature and pressure at the individual stage ports of the compressor. For example, the temperature and pressure of the bleed air at the individual stage port of the compressor increase when the engine is operated at a full power level in contrast to an idling condition. In another example, as the demand of a bleed airflow extracted from a particular stage port of the compressor increases, the air pressure and temperature delivered from this particular stage port of the compressor will decrease. All these factors will result in fluctuations and variations causing transient thermal stresses on the engine components and transient rubbing (pinch point) in the non-contact air and air/oil seals.
[0003] Accordingly, there is a need to provide an improved pressurizing air system for gas turbine engines to provide bleed airflows with relatively stable temperatures and pressures under most engine operating conditions.
SUMMARY OF THE INVENTION
[0004] It is therefore an object of this invention to provide a twin-air source pressurizing air system for gas turbine engines in order to provide relatively stable bleed airflows.
[0005] In one aspect, the present invention provides a passive pressurizing air system for a gas turbine engine which comprises a low pressure source of air and a high pressure source of air. An ejector is located in a cavity in fluid communication with the high pressure source of air. The ejector has a motive flow inlet thereof in fluid communication with the cavity, a secondary flow inlet thereof connected to the low pressure source of air and an outlet thereof connected to a pressurized area of the engine for delivery of a mixed air flow from the high and low pressure sources of air thereto.
[0006] In another aspect, the present invention provides a passive pressurizing air system for a gas turbine engine which comprises a flow path for directing an air flow having a first temperature and a first pressure from a pressure stage of a compressor of the engine to a pressurized area of the engine. The flow path extends through a cavity containing pressurized air having a second temperature and a second pressure greater than the respective first temperature and first pressure. Means are provided for adding the pressurized air from the cavity into the flow path to provide a mixed air flow having a temperature and a pressure intermediate to the first and second temperatures and the first and second pressures. The mixed air flow flows along the flow path downstream of the cavity, to the pressurized area of the engine.
[0007] In a further aspect, the present invention provides a method for reducing temperature variation of a pressurized air supply to a pressurized area of a gas turbine engine, which comprises directing a first air flow having a low temperature thereof from a low pressure source of air associated with the engine, to the pressurized area of the engine; and adding a second air flow having a high temperature thereof from a high pressure source of air associated with the engine, into the first air flow to provide a mixed pressurized air supply having an intermediate temperature thereof, to the pressurized area of the engine in a manner in which a ratio of energy distributed by the added second air flow in the mixed pressurized air supply varies to compensate for variations in the first air flow, thereby reducing variations in the intermediate temperature of the mixed pressurized air supply when the low temperature of the first air flow varies.
[0008] Further details of these and other aspects of the present invention will be apparent from the detailed description and drawings included below.
DESCRIPTION OF THE DRAWINGS
[0009] Reference is now made to the accompanying drawings depicting aspects of the present invention, in which:
[0010] FIG. 1 is a schematic cross-sectional view of a turbofan gas turbine engine as an example illustrating an application of the present invention;
[0011] FIG. 2 is a schematic illustration showing a twin-air source pressurizing air system, as one embodiment of the present invention illustrated in the engine of FIG. 1 ;
[0012] FIG. 3 is a schematic illustration of an ejector used in the embodiment of FIG. 2 ;
[0013] FIG. 4 is a chart illustrating air temperatures delivered by high pressure, low pressure ports and an ejector in the engine operation range according to the embodiment of FIG. 2 ; and
[0014] FIG. 5 is a schematic illustration showing another embodiment of the present invention illustrated in FIG. 1 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0015] Referring to FIG. 1 , a gas turbine engine incorporating an embodiment of the present invention is presented as an example of the application of the present invention and includes a housing or nacelle 10 , a core casing 13 , a low pressure spool assembly seen generally at 12 which includes a fan assembly 14 , a low pressure compressor assembly 16 and a low pressure turbine assembly 18 , and a high pressure spool assembly seen generally at 20 which includes a high pressure compressor assembly 22 and a high pressure turbine assembly 24 . The core casing 13 surrounds the low and high pressure spool assemblies 12 and 20 in order to define a main fluid path (not indicated) therethrough, including a chamber 26 containing and surrounding a combustor 28 . An air flow mixing apparatus 30 according to one embodiment of the present invention is located in the chamber 26 to be used for a twin-air source air pressurizing system of the gas turbine engine.
[0016] Reference is now made to FIGS. 1 and 2 . The low and high spool assemblies 12 and 20 of FIG. 1 are simplified in FIG. 2 for convenience of description. The twin-air source pressurizing air system is schematically illustrated and indicated generally by numeral 32 which includes an air flow path 34 connected to a low pressure source of air for example 2.5 P air from a stage of the low pressure compressor assembly 16 .
[0017] The air flow path 34 extends to one or more pressurized areas 36 of the engine, for example a space defined between labyrinth seal 38 and the rotor shaft 40 located downstream of the turbine assembly 24 . The air flow mixing apparatus 30 is incorporated into and thus forms part of the air flow path 34 .
[0018] The low pressure compressor assembly 16 as the low pressure source of air, provides an air flow having relatively low pressure and low temperature with respect to the pressurized air provided by the high pressure compressor assembly 22 as a high pressure source of air for the engine. The air flow extracted from the stage of the low pressure compressor assembly 16 which is represented by stage port 42 , is directed by the air flow path 34 to the pressurized area 36 for cooling or providing purging flow to the labyrinth seal 38 and other components downstream of the turbine assembly 24 which are located in a very high temperature environment.
[0019] Nevertheless, the air flow extracted at the stage port 42 of the low pressure compressor assembly 16 varies during various power setting conditions of the engine, the flight regime and customer bleed air demand. Variations in temperature and pressure of the air flow delivered to the pressurized area 36 accompany variations in the air flow. These variations cause transient thermal stresses on the engine components and transient rubbing (pinch point) in the non-contact air and air/oil seals.
[0020] Referring to FIGS. 2 and 3 and according to an embodiment of the present invention, the air flow path 34 preferably includes a segment of a pipeline 44 extending through a cavity 46 , for example, an annular chamber defined by the core casing 13 , containing and surrounding the combustor 28 as illustrated in FIG. 1 . The cavity 46 is in fluid communication with a stage of the high pressure compressor assembly 22 via a high pressure stage port 48 . High pressure air such as P3 air is therefore introduced into the cavity 46 for participating in combustion in the combustor 28 to generate combustion gases to drive the high pressure and low pressure turbine assemblies 24 , 18 , as illustrated in FIG. 1 (only high pressure turbine 24 is shown in FIG. 2 ). This high pressure air filled in the cavity 46 has a temperature and a pressure greater than the temperature and pressure of the low pressure air delivered at the low pressure stage port 42 . Although the temperature of the high pressure air delivered at the high pressure stage port 48 also varies depending on the rotational speed of the high pressure compressor assembly 22 , the engine is designed to deliver the high pressure air at the high pressure stage port 48 with a relatively stable rate into the cavity 46 .
[0021] The air flow mixing apparatus 30 preferably includes an ejector 50 profiled as a venturi tube and mounted on the segment of the pipeline 44 within the cavity 46 . The ejector 50 is a conventional device used to boost a low pressure stream to higher pressure streams, thereby effectively using available energy without waste. The ejector 50 includes a secondary flow inlet 52 and an outlet 54 . The secondary flow inlet and outlet 52 , 54 are connected to the segment of the pipeline 44 in series, the ejector 50 thereby forming part of the pipeline 44 , and thus part of the air flow path 34 , in order to allow the air flow extracted from the low pressure stage port 42 to flow therethrough to be supplied to the pressurized area 36 of the engine.
[0022] The ejector 50 further includes a motive flow inlet 56 which preferably includes a calibrated nozzle in fluid communication with the cavity 46 in order to allow the high pressure air filled within the cavity 46 to enter the ejector 50 . In such a configuration, high pressure air from a stage of the high pressure compressor assembly 22 can be extracted at the high pressure stage port 48 and added to the low pressure air flow through the air flow path 34 without any additional pipelines.
[0023] Due to the engine high pressure compressor ratio, the expansion ratio of the high pressure air flow in the calibrated nozzle (motive flow inlet 56 ) ensures a steady hot motive air flow into the ejector 50 under any engine operating regime, and this steady hot motive air flow is not perturbed by pressure changes of the low pressure air flow in the air flow path 34 . On the other hand, as previously discussed, the pressure of the low pressure air flow delivered at the low pressure stage port 42 varies within the engine operation regime. Small reductions in pressure of the low pressure air flow delivered at the low pressure stage port 42 , result in large reductions in the low temperature and low pressure air flow delivered into the pressurized area 36 of the engine. Hence, at low engine power, the air flow delivered to the pressurized area 36 originates mainly from the high pressure source (high pressure stage port 48 ) while at high power of engine operation, the air delivered to the pressurized area is a mixture of high pressure and low pressure air. Therefore, the ratio of energy distributed by the high temperature and high pressure air into the mixed air flow varies when engine operating conditions vary. Neverthless, the mixture of the high and low pressure air always has a temperature intermediate to the high and low temperatures of the respective high pressure and low pressure air and a pressure intermediate to the high and low pressures thereof.
[0024] The motive flow inlet 56 has a nozzle dimensioned such that the ejector 50 delivers the mixture of the high and low pressure air that provides the required temperature of the pressurized area 36 when the engine is operating at a high power. The low temperature and low pressure air flow will decrease at low power and thus the high temperature and high pressure air contribution will increase. Therefore, a ratio of energy distributed by the added high pressure air flow into the mixture of the high and low pressure air, varies to compensate for variation of the low pressure air flow delivered from the low pressure stage port 42 , thereby reducing variations in the intermediate temperature of the mixed pressurized air to be supplied to the pressurized area 36 when the temperature of the low pressure air flow extracted from the low pressure stage port 42 varies.
[0025] Besides functioning as an air flow mixing apparatus, the ejector 50 also attenuates perturbations of the low pressure air flow occurring at a constant engine speed. Such perturbations can be caused by customer bleed air flow rate increases or the Handling Bleed Off Valve (HBOV) opening. Any perturbation that reduces the air pressure and temperature delivered by the low pressure stage port 42 , results in a reduced low pressure air flow rate into the ejector 50 . As previously discussed, the energy provided by the high pressure air through the motive inlet 56 at an increased proportion relative to the total energy of the mixed air flow, results in both temperature and pressure gain in the ejector 50 . The required degree of attenuation is preferably obtained by the effective mixing length of the ejector.
[0026] FIG. 4 illustrates in chart form, the temperature changes at the high pressure stage port 48 (indicated by HP), low pressure stage port 42 (indicated by IP) and the output of the ejector 50 within the entire engine operating regime, from ground idling (indicated by GI) to taking off conditions (indicated by TO), in a temperature (indicated by T) and engines speed (indicated by N) coordinate system. FIG. 4 clearly illustrates that variations in the temperature at the output of the ejector 50 are much smaller than temperature variations at the respective high pressure stage port 48 and the low pressure stage port 42 when engine operating conditions change.
[0027] In accordance with another embodiment of the present invention illustrated in FIGS. 2 and 5 , the ejector 50 in the previous embodiment is eliminated, and instead a calibrated hole 58 is defined in the segment of the pipeline 44 extending through the cavity 46 . The calibrated hole 58 functions as the motive flow inlet 56 of the ejector 50 of FIG. 3 to introduce the high pressure air filled in the cavity 46 at a substantially stable rate, into the segment of the pipeline 44 . Thus, a part of the segment of the pipeline 44 downstream of the calibrated hole 58 functions as an air flow mixing apparatus, similar to the ejector 50 of FIG. 2 in order to produce a mixed air flow having the relatively stable intermediate temperature and pressure required in the pressurized area 36 of the engine.
[0028] Adjustment of the location of the calibrated hole 58 along the segment of the pipeline 44 within the cavity 46 will affect the intermediate temperatures of the mixed air flow delivered through the air flow path 34 into the pressurized area 36 of the engine when the low pressure air flow through the segment of the pipeline 44 is unchanged.
[0029] Heat exchange occurs between said segment of the pipeline 44 and the cavity 46 because the temperature of the cavity 46 (the temperature of the high pressure air) is higher than the temperature of said segment of the pipeline 44 . However, said segment of the pipeline 44 has different temperatures at the upstream and downstream portions with respect to the location of the calibrated hole 58 . The temperatures of the upstream portion are mainly affected by the low temperature of the low pressure air extracted from the low pressure stage port 42 and the temperature of the downstream portion is mainly affected by the intermediate temperature of the mixed air flowing therethrough. Therefore, the heat exchange rates of the respective upstream and downstream portions of the segment of the pipeline 44 are different.
[0030] The location change of the calibrated hole 58 varies the affected heat exchange contact areas at the different heat exchange rate portions, thereby affecting the resultant intermediate temperature of the mixed air flow eventually delivered into the pressurized area 36 of the engine. For example, the calibrated hole 58 moved to a downstream position will increase the heat exchange at the high exchange rate at the upstream portion of the segment of the pipeline 44 and will reduce the heat exchange at the relatively low heat exchange rate at a downstream portion of the segment of the pipeline 44 , resulting in more heat gain of the segment of the pipeline 44 within the cavity 46 and thus higher intermediate temperature of the mixed air flow delivered to the pressurized area 36 of the engine.
[0031] In contrast to the conventional twin-source air systems using variable geometry ejectors, the present invention advantageously uses a fixed geometry flow mixing apparatus as a temperature control device for the twin-source air system. Therefore, there are no moving parts, control systems or valves needed for effective functioning, and thus no servicing is required. The present invention by advantageously positioning the flow mixing apparatus within a high pressure cavity eliminates the need for additional piping and thus reduces the high pressure flow temperature variations. The resultant relatively stable temperature of the pressurized area alleviates transient thermal stresses in the engine components and transient rubbing (pinch point) in the non-contact air and air/oil seals.
[0032] The above description is meant to be exemplary only, and one skilled in the art will recognize that changes may be made to the embodiments described without departure from the scope of the invention disclosed. For example, the cavity can be any cavities defined within the engine which are in fluid communication with a high pressure source of air of the engine other than the exemplary chamber surrounding a combustor of the engine. The ejector position may be changed along the segment of pipeline within the cavity, similar to the adjustment of the calibrated hole defined in the pipeline, in order to adjust the heat exchange between the pipeline and the surrounding hot cavity. The segment of pipeline extending through the hot air cavity may be entirely or partially insulated, and a check valve may be installed in the motive flow inlet upstream of the injection point. Individual ejectors may be installed and calibrated for each pressurized area of the engine, not limited to the space defined by labyrinth seals. The flow mixing apparatus of the present invention may be combined with heat exchangers to further improve the effectiveness of the arrangement. Still other modifications which fall within the scope of the present invention will be apparent to those skilled in the art, in light of a review of this disclosure, and such modifications are intended to fall within the appended claims. | A passive pressurizing air system for a gas turbine engine comprises a flow path for directing an air flow having a low temperature and low pressure, extending through a cavity to a pressurized area of the engine. The cavity contains pressurized air having a high temperature and high pressure. Means are provided for adding the pressurized air from the cavity into the flow path to provide a mixed air flow having an intermediate temperature and intermediate pressure. | 5 |
This application is related to U.S. patent application Ser. No. 07/919,035 filed Jul. 24, 1992 for Closure Assembly for Structural Members which is a continuation-in-part of U.S. patent application Ser. No. 07/729,696 filed Jul. 15, 1991 for Closure Assembly for Structural Members now U.S. Pat. No. 5,163,495 issued Nov. 17, 1992 which is a division of U.S. Application Ser. No. 07/535,101 filed Jun. 8, 1990, now U.S. Pat. No. 5,131,450 issued Jul. 21, 1992.
BACKGROUND OF THE INVENTION
1. FIELD OF THE INVENTION
The present invention generally relates to a damage minimizing closure door that is moved vertically between open and closed positions in which the door is flexible and a guide assembly is mounted on the side edges of the doorway for receiving and guiding the side edges of the flexible door during vertical movement. The flexible door or curtain and the guide assembly include unique features which enable the side edges of the curtain to separate from the guide assembly upon being impacted by an externally applied force, such as by a vehicle, without damaging the curtain or guide assembly and also enabling the side edges of the curtain to be easily reinserted into the guide assembly.
2. DESCRIPTION OF THE PRIOR ART
Vertically disposed doors which move between open and closed positions are well known as are such doors or curtains constructed of flexible material with guides along the side edges of the opening receiving, retaining and guiding the side edges of the curtain. My prior U.S. Pat. Nos. 5,131,450 issued Jul. 21, 1992 and 5,163,495 issued Nov. 17, 1992 disclose this type of door. In addition, the following U.S. Patents also disclose structures which are relevant to this invention.
1,393,405
4,175,608
4,478,268
4,610,293
5,176,194
As indicated in the above patents and the prior art of record in those patents when a flexible door or curtain is used as a vertically movable door, it is necessary to provide a guide structure along the side edges thereof for retaining the side edges in a slot-like structure during vertical movement of the flexible door or curtain. Also, as indicated, it is desirable to provide a structure which enables the side edges of the flexible curtain to separate from the guide structure in the event the flexible curtain is subjected to an excessive impact force such as a vehicle striking the door but withstand wind or air pressure without disengagement from the guide. However, the above prior patents do not disclose a structure equivalent to the unique features of the present invention which guides the side edges of the flexible curtain, enables the side edges to separate from the guide structure upon excessive impact force and enables the side edges of the curtain to be easily reinserted into the guide structures thereby avoiding damage to the flexible curtain in the event of excessive impact forces engaging the flexible curtain.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a vertically opening and closing flexible door or curtain provided with a guide structure along the side edges of the door opening with cooperating structure on the side edges of the flexible curtain and on the guide structure to facilitate vertical movement of the flexible curtain, provide a windlock at the side edges of the flexible curtain and enable the side edges of the flexible curtain to be disengaged from the guide structure in the event of excessive impact force on the flexible curtain and enable the side edges of the flexible curtain to be quickly and easily reinserted into the guide structure after disengagement therefrom.
Another object of the invention is to provide a guide system as defined in the preceding object in which the side edges of the flexible curtain are provided with a windlock in the form of a lateral projection which engages with a windbar on the guide structure in which the windbar is constructed to enable separation of the windlock by providing a separable windbar which enables the windlock and curtain to disengage from the guide structure when the curtain receives excessive impact force.
A further object of the invention is to provide a guide system for a flexible curtain which includes a guide channel having a windbar thereon associated with a windlock on the edge of the flexible curtain in which the windlock is constructed of resilient, flexible tabs oriented and generally perpendicular to the curtain with the windlock being capable of flexing and bending to a substantially straight aligned relation to the curtain to enable separation of the curtain from the guide channel without damage to the curtain or the guide channel in the event of an excessive impact force coming into contact with the curtain.
Still another object of the invention is to provide a damage minimizing, low maintenance door which may include a roll up door mounted on a barrel or drum across the upper end of a doorway or in the form of a vertical lift door in which the door moves vertically completely above the upper edge of a doorway with various mechanisms being provided to facilitate movement of the door or flexible curtain between open and closed positions.
A still further object of the invention is to provide a guide system in accordance with the preceding objects in which the guide structure is provided with guides such as rollers or outwardly flared flanges forming a bell shaped guide at the top of the guide structure, weather stripping when required along each guide structure and across the top of the door opening and a bottom bar connected to the flexible curtain to provide an effective closure door for an opening with the closure door being either a roll up door or a full vertical lift door and the windlock being a substantially continuous narrow strip along each side edge of the curtain.
An additional object of the invention is to provide a bottom bar which evenly distributes the weight of the bottom bar across the width of the curtain by the use of a strip attached adjacent the bottom edge of the curtain on which the bottom bar retainer sits and is retained thereby reducing the amount of bolts needed to distribute said weight.
A still further object of the invention is to provide a damage minimizing door which uses a power spring (clock type) as a counter balance to raise the flexible curtain out of the opening.
These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevational view of a roll up type vertically moving door illustrating the guide structure along each side of the flexible door or curtain.
FIG. 2 is a sectional view taken substantially along section line 2--2 on FIG. 1 illustrating the specific structural details of the roller type guide at the upper end of the guide structure.
FIG. 3 is a sectional view taken along section line 3--3 on FIG. 1 illustrating guide rollers at the top edge of the guide structure.
FIG. 4 is a sectional view taken along section line 4--4 on FIG. 1 illustrating the specific structure of the guide structure and edge of the curtain.
FIG. 4A is an enlarged sectional view of a portion of FIG.
FIG. 5 is a sectional view taken along section line 5--5 on FIG. 1 illustrating the bottom bar construction connected to the bottom end of the flexible curtain.
FIG. 6 is an elevational view illustrating a full lift vertical door.
FIG. 7 is a top plan view thereof.
FIG. 8 is a sectional view taken along section line 8--8 on FIG. 6 illustrating the counterweight structure.
FIG. 9 is an elevational view illustrating a spiral spring assisted door which can be manually operated.
FIG. 10 is an elevational view, with portions in section, of the spring and its housing.
FIG. 11 is a sectional view taken along section line 11--11 on FIG. 10 illustrating details of the spring assembly.
FIG. 12 is a fragmental perspective view illustrating another embodiment of the guide and curtain.
FIG. 13 is a sectional view, on an enlarged scale, illustrating structural details of FIG. 12.
FIG. 14 is a perspective view of the segmental windlock.
FIG. 15 is an elevational view of the upper end of the guide structure illustrating a bell shaped guide.
FIG. 16 is a sectional view taken along section line 16--16 on FIG. 15 illustrating additional details.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1-5 disclose one embodiment of the invention generally designated by reference numeral 10 which includes a flexible door or curtain 12 having sufficient length and width characteristics to form a closure for a doorway or opening 14 in a wall 16 of a building structure. The door 10 includes a roll up drum generally designated by reference numeral 18 oriented at the top of the opening 14, a guide structure generally designated by reference numeral 20 along each side edge of the opening 14 and receiving and guiding the side edges of the curtain 12 and the bottom of the curtain 12 is provided with a bottom bar generally designated by reference numeral 22.
The structural details of the guide structure 20 is illustrated in FIG. 4 and includes an elongated, rigid support member 24 in the form of an angle or other structural member having a flange 26 secured to the wall 16 by any suitable fastening structures 28. The support member 24 also includes an outwardly extending flange 30 perpendicular to the flange 26 which supports a continuous inwardly facing guide member 32 with the guide member facing the doorway or opening 14 and including an inner flange 34 and an outer flange 36 generally parallel thereto with the flanges being connected at one end by a bight portion 38 that is secured to the flange 30 by a plurality of fasteners 40 in the form of bolts or the like which extend through an opening in the flange 30 and into a threaded opening 42 in the bight portion 38 of the member 32 with the flanges 34 and 36 being spaced apart to provide a groove or channel 44 which receives a side edge of the curtain 12.
As illustrated in FIG. 4, the side edge of the curtain 12 is provided with a strip 46 bonded to one surface of the side edge thereof with the strip being relatively narrow in width and also narrow in thickness with the thickness of the strip 46 being generally the same thickness as the curtain 12 although this relationship may vary. The side edge of the curtain and the strip 46 thereon serves as a windlock when associated with the guide member 32 as set forth hereinafter. The end edge of the flange 36 has an elongated retaining strip or windbar 48 mounted thereon with the windbar being constructed of plastic material and including a recess 50 in the surface thereof which faces the end edge of the flange 36 with the recess 50 being generally cylindrical in configuration but opening toward the flange 36 for snap mounting engagement with a projection or lip 52 on the end edge of the flange 36 with the lip 52 being of corresponding generally cylindrical shape for snap engagement with the recess 50 in the windbar 48. As illustrated, the windbar or strip 48 includes an inner flange portion 54 positioned interiorly of the flange 36 and projecting into the space 44 to abuttingly engage and retain the strip 46 and thus the edge of the curtain 12 within the channel shaped space 44. The construction of the windbar or strip 48 provides a low coefficient of friction with the curtain 12 and edge strip 46 and will effectively guide and retain the side edge of the curtain in the channel shaped space in the guide member 32. When the curtain 12 is in closed position and is impacted with an excessive force such as when a vehicle strikes the curtain, the lateral outward force exerted on the side edge of the curtain is resisted by the inner edge of the flange 54 on the strip 48 abutting the edge of the strip 46 until the lateral force overcomes the resilient snap mounting engagement between the recess 50 and the strip 48 and the projection 52 on the flange 36 is overcome at which time the strip 48 separates from the flange 36 and the side edge of the curtain 12 can separate from the guide member 32 with no damage or minimal damage to the curtain and guide structure.
This structure enables the side edge of the curtain 12 to be reinserted into the channel shaped space 44 and the resilient plastic strip 48 reattached to the projection 52 on the flange 36 by merely pressing the strip back into place by snapping the recess 48 onto the projection 52.
As illustrated in FIGS. 4 and 4A, the inner flange 34 is sometimes provided with a longitudinal spacer strip 56 which engages the surface of the curtain 12 in opposed relation to a portion of the strip 46 with the spacer strip 56 cooperating to insure engagement of the strip 46 against the windbar 48 to provide a windlock for the curtain 12 between the curtain 12 and the guide member 32. The spacer strip 56 is used when a thinner than normal curtain 12 is used to close the doorway. When a standard thickness curtain is used, the spacer strip 56 is not required. The strip 56 is replaceable by the use of a projection 58 on the surface of the strip 56 remote from the curtain 12 received in a recess 60 in the inner surface of the flange 34. The strip 56 is also constructed of plastic material while the guide member 32 is constructed of metal such as aluminum or other rigid material. The flange 34 is also provided with a weather stripping member 62 extending along the inner surface of the flange 32 and secured thereto by fastener 64 with the outer end of the weather stripping 62 including a brush member 66 engaging the surface of the curtain 12 inwardly of the guide member 32 and windbar 48 as illustrated in FIG. 4 to further provide a sealing relationship between the curtain 12 and the guide structure 20.
FIGS. 2 and 3 illustrate further structural details of the door 10 including a cylindrical drum 68 having one end of the curtain 12 attached thereto and wound thereon during rotation of the drum 68 which is supported by shaft structure 70 journaled in enlarged support plates 72 attached to the upper ends of flanges 30 on the support structure 24 by the use of bolt type fasteners 74 extending through slot opening 76 in the plate 72 to enable some adjustment of the position of the drum 68.
The upper end of the guide structure 20 includes a pair of guide rollers 78 and 80 spaced from each other and rotatably supported on elongated fastener bolts 82 and internal spacer sleeves 84 and 86. The roller 78 includes a cylindrical external surface and the roller 80 includes a generally cylindrical external surface but which includes a radially outwardly offset end portion 88 which receives the strip 46 on the edge of the curtain 12 with the radially offset end portion 86 defining an abutment edge 89 engaging and guiding the inner edge of the strip 46 as illustrated in FIG. 3 during movement between the rollers 78 and 80 which are idler rollers with the external surfaces thereof being generally in alignment with the channel shaped recess 44 between the flanges 34 and 36 on the guide member 32 as illustrated in FIG. 2 thus guiding movement of the curtain 12 when it is being wound onto or off of the drum 68 thus guiding the curtain in relation to the guide structure 20 and specifically guiding the strip 46 into the channel shaped space 44. A weather stripping member 90 is mounted on a bracket 92 connected to the wall 16 above the doorway opening 14 and includes a weather seal brush 94 in engagement with the surface of the curtain 12 which faces the wall 16 which, together with the weather seal brushes 66 forms a complete seal along the top and side edges of the flexible curtain when the flexible curtain is in lowered or closed position.
FIG. 5 illustrates the construction of the bottom bar 22 which is a rigid structure connected to the lower end of the curtain 12 and terminates about an inch from the guide structure 20. The bottom bar 22 includes a pair of identical rigid members 95 and 96 each of which includes an indentation 97 in the inner surface. The indentation 97 includes a lip 98 which extends downwardly to engage an upturned lip 99 on a mounting strip 100. The mounting strips 100 carries and evenly distributes the weight of the bottom bar 22 across the width of the curtain 12 to keep the curtain taut and assist the downward travel of the curtain in the guide system along the side edges. The upturned lip 99 on each mounting strip 100 receives the downturned lip 98 and helps to retain the bottom bar 22 on the strips 100 which are secured to the curtain 12 such as by welding or sewing. Bolts 101 retain the bottom bar members 95, 96 on the mounting strips 100 and curtain 12 by clamping the members to the strips and curtain. The lower bottom portion of each of the members 95 and 96 is provided with a continuous cavity 102 extending therethrough capable of receiving one or more elongated weight members 103 in the form of elongated rods, cables or the like to vary the total weight of the bottom bar. The bottom edges of the members 95 and 96 have downwardly facing T-shaped grooves 104 receiving correspondingly shaped projection on a hollow, generally semicircular seal member 106 which sealingly engages the bottom surface or floor surface forming the bottom of the door opening 14 thus forming a seal for the bottom edge of the flexible curtain 12 where it engages the floor or bottom surface of the opening and the weight of the bottom bar will retain the flexible curtain 12 in a taut, straight line condition when the bottom bar 22 is spaced from the bottom surface 108 of the opening 14.
FIGS. 6-8 disclose a vertical lift door generally designated by reference numeral 110 and which includes a flexible door or curtain 112 guided by guide structures 114 which are the same in construction as the guide structures 20 in FIGS. 1-5 except that the guide structures 114 extend a vertical distance above the doorway 116 to enable the flexible curtain 112 to move vertically upwardly in a straight line condition until the bottom bar 118 is positioned in line with or above the doorway 116. The upper end of the guide structures 114 have a cable pulley or sheave 120 supported by a bracket structure 122 on the wall 124 with a cable 126 entrained over the pulley 120 with one end of the cable 126 extending downwardly along the outside of the upper portion of the guide structure 114 and being attached to a cable bracket 128 mounted on the upper edge of the flexible curtain 112. The other end of the cable 126 extends downwardly in spaced relation to the upper portion of the guide structure 114 and has a counterweight 130 attached thereto with the counterweight being vertically movably mounted in a vertically disposed guide tube 132 secured to the guide structure and wall structure in a manner to enable the counterweights 130 to balance or partially balance the weight of the flexible curtain or door to facilitate manual vertical movement of the flexible curtain 112 between open and close positions.
FIGS. 9-11 illustrate a manually operated roll up door 140 including a flexible curtain 141 and guide structures 142 and a bottom bar 143 which are the same as the structure illustrated in FIGS. 1-5 except that the drum or barrel 144 across the upper end of the door opening can be manually operated by a hand chain drive 145 at one end thereof or by a motor 146, gear box 147 and drive sprocket and roller chain 148 at the same end to drive shaft 149 which supports drum 144. An emergency release pull chain 150 enables the motor 146 or chain drive 145 to operate the shaft 149 and drum 144. If a hand chain operation is selected as the primary mode of operation, the motor 146, gear box 147 and chain drive 145 will be omitted. At the other end of the drum 144, a counterbalancing spring mechanism 151 which includes a spiral power spring 156 received in a housing or frame 154 with one end of the spring 156 connected to the housing or frame 154 and the other end connected to shaft 149. The spring housing 154 is supported from a mounting plate 152 attached to guide structure 142. The plate 152 includes lateral angle clips 153, preferably welded thereto, which support the hollow housing 154 by adjusting bolts 155 which interconnect the angle clips 153 on the plate 152 and angle clips 157 fastened around the outside circumference of the housing 154. A spiral power spring 156 is positioned in housing 154 with the outer end of the spring being secured to the housing 154 and the inner convolution secured to an end of the shaft 149 by a keyed casting 158. The barrel 144 and shaft 149 are supported by bearings 160 in plates 152. The spring counterbalance mechanism 151 supports and assists the manual movement of the flexible curtain 141 between open and closed positions thereby reducing the force necessary to open and close the door or curtain. The spring mechanism may be easily replaced to reduce maintenance costs and other types of springs typically used in the industry, such as a torsion spring enclosed in a barrel, can be used as a counterbalancing spring.
FIGS. 12-16 illustrate a modified guide structure 20 in which the flanges 34' and 36' flare away from each other and the bight portion of the channel shaped member 32' is omitted or separated from the flanges 34' and 36' thus enabling the flanges to be flared upwardly and outwardly to form a bell shaped upper end to the guide structure illustrated.
An optional structure for retaining the side edges of the door curtain in relation to the guide structure is illustrated in which the curtain is designated by reference numeral 161 having attached to the side edges thereof a segmental flexible, bendable and resilient windlock in the form of spaced angled tabs 162 attached to curtain 161 by fasteners 163 in a manner to enable the curtain to be wound onto a drum or barrel at the upper end. The guide structure includes flanges 164 and 166 defining a guide channel with the flange 166 being detachable by a bolt and nut arrangement 168. The flange 164 is provided with a stationary windbar or projection 170 which engages the curtain 161. As illustrated in FIGS. 13 and 14, the segmental tabs 162 are flexible and bendable and provided with memory or resilient characteristics sufficient to enable the tabs 162 to bend to a substantially straight condition in alignment with the curtain 161 to enable the curtain 161 to be separated from the guide structure by moving past the windbar 170. In this embodiment of the invention, the windlock formed by tabs 162 and side edge of the curtain 161 is reinserted into the guide structure by removing the nut and bolt fasteners 168.
The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and, accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention. | A damage minimizing closure door that is moved vertically between open and closed positions in which the door is a flexible curtain and a guide assembly is mounted on the side edges of the doorway for receiving and guiding the side edges of the flexible door during vertical movement. A counterbalancing power spring is associated with the door to assist in raising and lowering the curtain. The flexible door or curtain and the guide assembly include unique features which enable the side edges of the curtain to separate from the guide assembly upon being impacted by an externally applied force, such as by a vehicle, with little if any damage occurring to the curtain or guide assembly. | 4 |
REFERENCE TO RELATED APPLICATION
This application is a Continuation in Part of U.S. patent application Ser. No. 06,571,397 filed on Jan. 17,1984, now abandoned.
BACKGROUND OF THE INVENTION
This invention relates to resealable package of the type adapted to inhibit or prevent vapor transmission to or from the interior of the package. Packages of this type are generally used for breakfast cereals, snack foods, flour mixes, and other applications requiring low vapor transmission throgh the package. Conventional packages used for these materials normally employ an outer paperboard package and an inner bag which contains the product. While the sealed inner bag may aid in reduced vapor transmission, once this type of package has been opened, it is very difficult to reseal the package to prevent the transmission of vapor into or out of the package. The present invention, on the other hand, provides a package which not only eliminates the need for a bag within the paperboard package, but also provides a means for resealing the package to inhibit the transmission of vapor into or out of the package. While packages with removable tops are known in the art, no prior art package exists which provides the vapor proof barrier as does the present invention.
SUMMARY OF THE INVENTION
The present invention comprises a resealable paperboard package which includes a base, a removable film layer, and a top. The base comprises a bottom and a plurality of base side panels extending upwardly from the bottom. The base side panels are secured together to form a base with an open upper end. Each base side panel has a base side panel extension hingedly joined thereto along a fold line at the upper edge of the base side panel. Each base side panel extension extends at an angle to the base side panel to which it is attached and is biased outwardly from the base side panel. The removable film layer is preferably a transparent film which is heat sealed to the upper open end of the base portion.
The top comprises a top central panel and a plurality of top side panels attached to, and depending from, the top central panel. The top central panel and the side panels are secured together to form a top with an open lower end complementary in shape to the open upper end of the base. The top is positioned over the open upper end of the base and the removable film layer. The top side panels are then in intimate contact with the base panel extensions which are biased into engagement with the top side panels. The removable film layer may or may not extend beyond the open upper end to contact the side panel extensions.
Upon receipt by the user, the top is secured to the base but is adapted to be separated wholly or partially from the base. After removal of the top, the removable film layer may be removed to expose the contents of the base portion. After use, the top may be replaced over the upper open end of the base. The frictional contact of the top and the base side panel extensions provides a substantially vapor proof seal to protect the contents.
The base and the top are made from paperboard coated on all surfaces with a heat sealing vapor proof coating. This coating is preferably polyethylene. The film layer is preferably treated polypropylene. The coated base and top are heat sealed so that the product contained within the package remains free flowing and the migration of vapor into or out of the interior of the package is prevented. Another advantage of the present invention relates to the reinforcement of the base side walls by the top. For certain applications this will allow the package to be formed from a lower point paperboard.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a plan view of the base blank;
FIG. 2 is a plan view of the preferred embodiment of the top blank;
FIG. 3 is a plan view of an alternate embodiment of the top blank;
FIGS. 4-6 are schematic representations illustrating the fabrication of the base from the base blank;
FIGS. 7-10 are schematic representations of the formation of the top from the top blank;
FIG. 11 is an isometric view of the package showing the top, the removable film layer, and the base separated;
FIG. 12 is an isometric view of the finished package;
FIG. 13 is an isometric view of the alternate embodiment of the top portion;
FIG. 14 is an isometric view of the package showing the top, the removable film layer, and the base separated;
FIG. 15 is an isometric view of the finished package with the top portion of FIG. 13; and
FIG. 16 is a top view of the side seam flap heat sealed to the side panel.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, the base is formed from blank 20 which is illustrated in plan view in FIG. 1. The blank 20 includes four base side panels 22, 24, 26 and 28, two bottom panels 30 and 32, and two bottom gusseted tuck panels 34 and 36. Base bottom panels 30, and 32, are hingedly joined to the base side panels 28 and 24 respectively along horizontal score line 38 which extends along the lower edge of the base side panels. Tuck panels 34 and 36 are hingedly joined to base side panels 26 and 22 respectively along score lines 39 which are slightly offset from score line 38 as will be explained in more detail. Base side panels 22, 24, 26 and 28 are hingedly joined to each other by vertical score lines 40, 42 and 44 which coincide with the vertical edges of the base side panels intermediate panels 22 and 24, and 24 and 26, and 26 and 28 respectively.
The base side panels are provided with sealing extensions 46, 48, 50 and 52 which are hingedly joined to panels 22, 24, 26 and 28 respectively along a common horizontal score line 54 which extends along the upper edges of the base side panels. The sealing extensions 46, 48, 50 and 52 each extend the entire width of the base side panel to which they are joined and are separated from each other by cuts 55, 56, 58 and 60. The cuts 55, 56, 58 and 60 are aligned with score lines 64, 40, 42 and 44 respectively and extend completely through the paperboard from the free edges of the sealing extensions to the score line 54.
Referring to FIG. 1, the outside surface of blank 20 is shown. Both the outside surface and the inside surface (not shown) of the paperboard blank are coated with a heat sealable coating. Preferably, the outside surface is coated with 0.5 mil thickness of low density polyethylene. The inside surface is preferably coated with 1 mil thickness of high density polyethylene and then 0.5 mil thickness of low density polyethylene. These polyethylene layers are co-extruded onto the paperboard and provide the vapor proof barrier as well as allowing the surfaces to be heat sealed. Heat sealing the low density polyethylene layers together forms an extremely strong, vapor-proof seal. The use of conventional adhesives is thus eliminated. While polyethylene is a preferred coating, any suitable heat sealable coating may be applied to the paperboard as long as the coating is non-strippable and provides a strong bond. An example of a strippable coating is wax which may be intentionally or unintentionally scraped from the paperboard thus affecting the vapor proof characteristic of the package. Wax is also unsuitable because of its weak bonding strength.
A score line 64 hingedly joins base side panel 22 to a side seam flap 66. Flap 66 has fold over flap 62 connected thereto along fold line 63. Prior to assembling the base, flaps 62 and 66 are skived on the outside surface and flap 62 is folded over onto flap 66 such that the skived surfaces are in contact. By skiving is meant the removal of a predetermined thickness of paperboard by abrasion or other methods as are known in the art. Flap 66 may be folded along score line 64 and heat sealed to the inner surface of panel 28 adjacent the free vertical edge of that panel to form a sleeve from blank 20 during the package forming operation. Because flap 62 is folded over onto flap 66 prior to heat sealing, it is the inner coated surface of flap 62 which is heat sealed to panel 28. The skiving allows the thickness of flap 66 and flap 62 to equal one thickness of paperboard. Thus panel 28 is held flat against flap 66 as shown in FIG. 16.
Tuck panels 34 and 36 are hingedly joined to bottom panels 30 and 32 along score lines 40, 42 and 44. Tuck panels 34 and 36 comprise three generally triangular shaped sections which are defined by score lines 44, 39, 42, 68, 70, 40, and 64. Tuck panels 34 and 36 are adapted to be folded along the beforementioned fold lines to be tucked under bottom panels 30 and 32 as will be explained in more detail. Inner bottom panel 30 is defined by score line 38 and score line 44 which hingedly joins inner bottom panel 30 to tuck panel 34. Outer bottom panel 32 is defined by score lines 38, 40, and 42. Score lines 40 and 42 join panel 32 to tuck panel 34 and 36. Inner bottom panel 30 includes rounded corners 72 while outer bottom panel 32 includes angled corner 74.
The grain of the paperboard in the base blank 20 extends parallel to score lines 38 and 54. The grain of the paperboard in the top blank 76 extends parallel to score lines 88 and 90. With the grains running in these directions the extensions 46, 48, 50 and 52 and the panels 80 and 82 tend to remain flat. With the grains running perpendicular to the preferred direction the extensions 46, 48, 50 and 52 may tend to become wavy thus adversely affecting the seal between the top and the base.
Referring to FIGS. 1 and 4-6 the base blank 20 is folded along score lines 64, 40, 42 and 44 to form a sleeve with the inner polyethylene coated surface of base side panel 28 adjacent its free edge overlapping the polyethylene coated flap 66. The inside surface of panel 62 and the non-skived outside surface of flap 66 are heat sealed to the inner surface of the base side panel 28 as shown in FIG. 16 to form the sleeve shown in FIG. 4. The side seam of the sleeve has no raw edges to permit moisture migration and the bond between the inside polyethylene coated surfaces forms a vapor proof seal. As shown in FIG. 16, only inner coated surface of panel 66 and fold line 63 are presented to the inside of the package. Thus, wicking of moisture from exposed edges such as edge 65 is prevented. Wicking occurs because uncoated paperboard edges tend to absorb moisture and carry it through the paperboard fibers and onto the package.
After the sleeve is formed the sealing extensions 46, 48, 50 and 52 are folded back along score line 54 toward their adjacent base side panels. However, because of the memory of the paperboard, the extensions are biased outwardly from the base side walls and do not lie flat against the sidewalls.
Tuck panels 34 and 36 are folded along score lines 39, 40, 42, 44, 64, 68, 70 and base panels 30 and 32 are folded along score line 38 to the position shown in FIG. 4 and then FIG. 5. Inner bottom flap 30 is then folded under flap 32 such that rounded corners 72 are inserted between the inside surfaces of flap 32 and tuck panels 34 and 36. As with the side seam, inner bottom flap 30 may include an extra panel such as panel 62 which may be folded back over flap 30 so as to present a rounded inside coated surface to the interior of the package. The bottom is then folded as in FIG. 6 and the bottom is heat sealed such that all contacting surfaces now form the polyethylene to polyethylene bond. With this bottom construction bottom panels 30 and 32 and tuck panels 34 and 36 exposed to the interior of the package are all polyethylene coated surfaces which are heat sealed. Accordingly, the assembled bottom presents no raw edges which would allow moisture migration and the bond between the polyethylene coated surfaces forms a vapor proof seal. After the base is formed it is filled with the material to be packaged. The material to be packaged is omitted from the FIGS. for ease of illustration.
As illustrated in FIG. 2, the top is formed from a blank 76 which includes a top central panel 78 and top side panels 80, 82, 84 and 86. Side panels 80 and 82 are located on opposite sides of the top central panel 78 and are hingedly joined to the top central panel by score lines 88 and 90. The top side panels 84 and 86 have a horizontal dimension equal to the dimension of the top central panel edge to which they are joined along score lines 92 and 94 and a vertical dimension equal to the vertical dimension of the top side panels 80 and 82. The top side panels 84 and 86 are located on opposite sides of the top central panel 78 and are hingedly joined to the top central panel by score lines 92 and 94 respectively. The top side panels 80 and 82 have a horizontal dimension equal to the horizontal dimension of the top central panel edge to which they are joined.
Top side panels 80 and 82 have release panels 96 and 98 depending therefrom and hingedly joined thereto along score lines 100 to 102 respectively. The horizontal dimensions of the panels 96 and 98 equal the dimension of the top side panel edge to which they are joined. Gussetted corner flaps 108 are joined to top side panels 80, 82, 84 and 86 along fold lines 88, 90, 92 and 94.
The top is formed as shown in FIGS. 7-10 on a mandrel (not shown). Side panels 80 and 82 are folded along fold lines 88 and 90 as shown in FIG. 8. Then, as shown in FIG. 9, side panels 84 and 86 are folded along fold lines 92 and 94. During this process gussetted flaps 108 are folded along diagonal fold line 110. Finally, flaps 108 are folded along fold lines 88 and 90 to contact side panels 84 and 86 as shown in FIG. 10. Flaps 108 are then heat sealed to side panels 84 and 86 by the same process as previously discussed. The result is a top, the corners of which are vapor proofed due to the polyethylene to polyethylene bond on all contacting surfaces.
As shown in FIG. 11, once top 76 and base 20 are formed, they are assembled with a flexible film 112. Film 112 is preferably a polypropylene transparent film which is biaxially oriented polypropylene. This film is coated with polyvinylidene chloride (PVDC), which allows the film to be heat sealed to the upper open end 114 of base 20 which is defined by fold line 54. The use of the flexible film 112 allows the contents contained in base 20 to be vacuum sealed within the base. Once the film 112 is in place, top 76 is placed over the film 112 and base 20 and flaps 96 and 98 are heat sealed to base 20 to secure top 76 to base 20. A user, upon opening the package, simply pulls release panels 96 and 98 away from base 20. Flexible film 112 may then be peeled off base 20 to allow the contents of base 20 to be poured through upper open end 114. The completed package is as shown in FIG. 12.
After the user has removed as much of the contents of base 20 as is desired, top 76 may be placed back onto base 20 at which time flaps 46, 48, 50 and 52, being biased outwardly as previously described, will contact the inside of top 76, more specifically, top side panels 80, 82, 84 and 86. Because of the polyethylene coating on all surfaces of the container, the polyethylene to polyethylene frictional contact in conjunction with the outward bias of flaps 46, 48, 50 and 52, provide a substantially vapor proof seal to the interior of base 20. Thus, the contents of the container are protected and the container may be repeatedly opened and closed without subjecting the contents to harmful enviromental forces. Previous packages, even though they did allow for removal and replacement of the top, did not provide a vapor proof seal as does Applicant's invention. While some prior are devices may have employed a coating such as wax, such coating would be unsuitable for the present invention in that wax is a strippable coating which may be degraded or removed and thus weakens or destroys the vapor proof seal.
Referring to FIGS. 3 and 13, an alternate embodiment of the top may be employed if desired. A top blank 116 is shown which is identical to blank 76 shown in FIG. 3 except for the addition of fold line 118 and skip cut portions 120. Skip cut portions extend from the angled edge of flaps 96 and 98 to fold lines 88 and 90 at top center portion 78. Fold line 118 extends from fold 88 across top center portions 78 to fold line 90. Blank top 116 is formed as was the previously disclosed top 76 as shown in FIGS. 7-10. The finished top 116 is as shown in FIG. 13.
Referring to FIG. 14, top 116 may be assembled to base 20 as was previously described with respect to FIG. 11. The resultant package is as shown in FIG. 15. However, as shown in FIG. 14, rather than removing entire top 116, the user need only to break the heat sealed bonds on one portion of the top 116. That is, one half of top 116 may be heat sealed entirely along panels 96 and 98 to base 20 while the other half of top 116 may be lightly heat sealed. The user may then, by releasing only the lightly heat sealed portion of top 116, separate portions of side top panels 96, 98, 80 and 82 along skip cuts 120. The user may then fold a portion of top 116 back along fold line 118 as shown in FIG. 14. The result is that only a portion of the open end 114 of base 20 is open. This may be desired where it is undesirable for the entire top to be removed. While skip cut 120 and fold line 118 are shown approximately equidistant between fold lines 92 and 94 of top blank 116 in FIG. 2, it should be expressly understood that the skip cut and fold line could be located at any point between fold lines 92 and 94. Thus, while in FIG. 14, approximately half of top 116 is shown folded back, one third, two thirds, ninety percent or any other portion of top 116 could be folded back by locating skip cut 120 and fold line 118 appropriately. It is even possible that the entire top 116 could be folded back and yet stay attached to base 20. This would be accomplished by locating skip cut 120 and fold line 118 immediately adjacent to score lines 92 or 94.
While a preferred and an alternate embodiment of the invention have been disclosed, it is not to be so limited as changes and modifications may be made which are within the full intended scope of the invention as defined by the appended claims. For example, while preferred coatings have been disclosed for the package, any heat sealable non-strippable coating which results in a vapor proof seal may be employed without departing from the full intended scope of the invention. In addition, while a particular flexible film has been disclosed other suitable films may be advantageously employed with the invention as long as those films are capable of being heat sealed to the base to form a vapor proof seal. In addition, the amount of heat sealing of the film to the base may be varied to make portions of the flexible film extremely difficult to remove. That is, the degree of heat sealing could be varied such that only a certain portion of flexible film could be peeled from the base. This would accomplish substantially the same result as disclosed by the alternate embodiment of the top of FIGS. 2, 13, and 14. | A resealable paperboard package has all surfaces thereof coated with a moisture resistant, non-slippable, heat sealable material and is provided with outwardly biased side panel extensions located about the upper periphery of the base which intimately contact the side panels of the top to form a seal between the base and the top even when the top is replaced on the base after the package has been opened. A flexible sheet is heat sealed to the upper periphery of the base. | 8 |
This application is the National Phase of International Application PCT/GB99/04278 filed Dec. 16, 1999 which designated the U.S. and that International Application was published under PCT Article 21(2) in English.
FIELD OF THE INVENTION
This invention relates to reduction of malodour and concerns methods and compositions for reducing malodour.
BACKGROUND TO THE INVENTION
It is clearly desirable to be able to reduce malodours in many circumstances, eg in domestic environments where common malodours include kitchen malodour, bathroom (lavatory) malodours, and malodours in carpets and furnishings eg caused by pets. Other common types of malodour include body malodour and malodours on clothes, eg caused by perspiration, smoke, environmental odours etc. The term “malodour” is used to refer to smells or odours generally regarded as undesirable or unpleasant in nature.
It is well known to incorporate fragrance or perfume materials in a wide range of products such as kitchen and bathroom cleaning products, air fresheners, carpet and fabric cleaners, laundry products, personal hygiene products etc, with a view to reducing such malodours. See, for example, WO 97/07778 and EP 0780132.
The present invention is based on the surprising discovery that certain known perfume or fragrance materials, when used in admixture with one or more other perfume or fragrance materials, have a greater effect in reducing malodours than would be expected or predicted based on the effect in reducing malodours of the materials on their own, thus indicating the presence of a synergistic effect.
The perfume or fragrance materials concerned are as follows:
1. 5-methyl-2-(2-methylpropyl)-1,3-dioxane, which is described in WO 96/30359, and which will be referred to herein as “Camonal” or “Cam” for brevity.
2. Methyl 1,4-dimethylcyclohexylcarboxylate, which is described in EP 0673408, and which will be referred to herein as “Cyprisate” or “Cy” for brevity.
3. 3-(((1-ethyloxy)ethyl)oxy)-3,7-dimethyl-1,6-octadiene, which is described in GB 1371727, and which will be referred to herein as “Elintaal” or “E1” for brevity.
4. 7,9-dimethylspiro(5,5)undecan-3-one, which is described in EP 0074693, and which will be referred to herein as “Dispirone” or “Dis” for brevity.
While these 4 materials are known to have attractive fragrance properties, their beneficial effect, when in admixture with other fragrance materials, in reducing malodours is not known and is not predictable.
SUMMARY OF THE INVENTION
In one aspect the present invention provides a fragrance composition comprising a mixture of two or more fragrance materials, including one or more of the following materials at least at the following minimum amounts by weight:
1. 5-methyl-2-(2-methylpropyl)-1,3-dioxane (Camonal) in an amount of at least 0.25%;
2. methyl 1,4-dimethylcyclohexylcarboxylate (Cyprisate) in an amount of at least 0.5%;
3. 3-(((1-ethyloxy)ethyl)oxy)-3,7-dimethyl-1,6-octadiene (Elintaal) in an amount of at least 15%; and
4. 7,9-dimethylspiro(5,5)undecan-3-one (Dispirone) in an amount of at least 2.5%.
In this specification, all references to % are % by weight unless otherwise specified.
The fragrance composition preferably includes at least two of the specified materials, preferably at least at the specified minimum amounts.
Camonal is preferably present at an amount of at least 7.5%. Cyprisate is preferably present in an amount in the range 0.5 to 15%. Elintaal is preferably present in an amount in the range 15 to 30%. Dispirone is preferably present in an amount of at least 2.5%.
There is a hedonic advantage in using mixtures as this allows a wider variety in fragrance hedonics to be produced with the same performance levels.
Mixtures containing 1:1:1 ratios of three of the ingredients perform well in all combinations. Mixtures containing 1:1 ratios of the ingredients should preferably contain Camonal or Cyprisate for good performance. Mixtures containing 1:1 ratios of Dispirone with an other ingredient should be avoided unless Camonal is used. Mixtures containing 2:1 ratios of ingredients perform best with either Canonal or Cyprisate at the highest proportion ingredient.
The terms “fragrance” and “perfume” are used synonymously in the present specification.
The terms “fragrance material” or “perfume material” are used herein to refer to a material which is added to a perfume or fragrance composition to contribute to the olfactive properties of the composition material. Typically, a perfume material will be generally recognised as possessing odours in its own right, will be relatively volatile and often has a molecular weight within the range 100 to 300. Typical perfume materials are described in “Perfume and Flavour Chemicals”, Volumes I and II (Steffan Arctander, 1969).
The terms “perfume composition” or “fragrance composition” are used herein to mean a mixture of fragrance materials, if desired mixed with or dissolved in a suitable solvent or mixed with a solid substrate. The mixture may be a complex mixture of many ingredients. The composition may be used to impart a desired odour to the skin and/or any product for which an agreeable odour is indispensable or desirable. Examples of such products are: fabric washing powders, washing liquids, fabric softeners and other fabric care products; detergents and household cleaning, scouring and disinfection products; air fresheners, room sprays and pomanders; soaps, bath and shower gels, shampoos, hair conditioners and other personal cleansing products; cosmetics such as creams, ointments, toilet waters, preshave, aftershave, skin and other lotions, talcum powders, body deodorants and antiperspirants, etc.
Other fragrance materials which can advantageously be employed in the fragrance composition according to the invention are, for example, natural products such as extracts, essential oils, absolutes, resinoids, resins, concretes etc., but also synthetic materials such as hydrocarbons, alcohols, aldehydes, ketones, ethers, acids, esters, acetals, ketals, nitrites, etc., including saturated and unsaturated compounds, aliphatic, carbocyclic and heterocyclic compounds.
Such fragrance materials are mentioned, for example, in S. Arctander, Perfume and Flavor Chemicals (Montclair, N.J., 1969) in S. Arctander, Perfume and Flavor Materials of Natural Origin (Elizabeth, N.J., 1960) and in “Flavor and Fragrance, Materials—1991”, Allured Publishing Co. Wheaton, Ill. USA.
It is preferred that other fragrance materials used in the fragrance composition of the invention are themselves not particularly good at reducing malodour but have medium, neutral or poor performance in this regard. The presence of one or more of Camonal, Cyprisate, Elintaal and Dispirone in the composition improves the malodour reduction properties of the composition.
Examples of fragrance materials which can be used in fragrance compositions to the invention are: geraniol, geranyl acetate, linalol, linalyl acetate, tetrahydrolinalol, citronellol, citronellyl acetate, dihydromyrcenol, dihydromyrcenyl acetate, tetrahydro-myrcenol, terpineol, terpinyl acetate, nopol, nopyl acetate, 2-phenylethanol, 2-phenylethyl acetate, benzyl alcohol, benzyl acetate, benzyl salicylate, styrallyl acetate, benzyl benzoate, amyl salicylate, dimethylbenzyl-carbinol, trichloromethylphenylcarbinyl acetate, p-tert-butylcyclohexyl acetate, isononyl acetate, vetiveryl acetate, vetiverol, α-hexylcinnamaldehyde, 2-methyl-3-(p-tert-butylphenyl)propanal, 2-methyl-3-(p-isopropyl-phenyl)propanal, 3-(p-tert-butylphenyl)-propanal, 2,4-dimethylcyclohex-3-enyl-carboxaldehyde, tricyclodecenyl acetate, tricyclodecenyl propionate, 4-(4-hydroxy4-methylpentyl)-3-cyclohexenecarboxaldehyde, 4-(4-methyl-3-pentenyl)-3-cyclohexenecarboxyaldehyde, 4-acetoxy-3-pentyltetrahydropyran, 3-carboxymethyl-2-pentyl-cyclopentane, 2-n-heptylcyclopentanone, 3-methyl-2-pentyl-2-cyclopentenone, n-decanal, n-dodecanal, 9-decenol-1, phenoxyethyl isobutyrate, phenyl-acetaldehyde dimethyl-acetal, phenylacetaldehyde diethylacetal, geranyl nitrile, citronellyl nitrile, cedryl acetate, 3-isocamphyl-cyclohexanol, cedryl methyl ether, isolongifolanone, aubepine nitrile, aubepine, heliotropin, coumarin, eugenol, vanillin, diphenyl oxide, hydroxycitronellal, ionones, methylionones, isomethylionones, irones, cis-3-hexenol and esters thereof, indan musks tetralin musks isochroman musks macrocyclin ketones, macrolactone musks, ethylene brassylate.
Solvents which can be used for fragrance compositions according to the invention are, for example: ethanol, isopropanol, diethyleneglycol monoethyl ether, dipropylene glycol, diethyl phthalate, triethyl citrate, isopropyl myristate, etc.
The fragrance composition may be in the form of a fragrance base, that is typically a mixture of many fragrance materials (up to, say, 50) intended to be mixed in use with a neutral complex fragrance. The resulting mixture also constitutes a fragrance composition in accordance with the invention, and may be intended to be used either as a fragrance in its own right or to impart desirable fragrance (and malodour reduction properties) to a product, typically a consumer product, eg as discussed above.
The present invention therefore also provides a product comprising a fragrance composition in accordance with the invention.
The fragrance composition is used in the product at a suitable level depending on the product, to achieve the desired effect in terms of fragrance and malodour reduction properties of the product, with typical levels being in the range 0.1 to 10% by weight.
In a further aspect, the invention also provides use of Camonal, Cyprisate, Elintaal and/or Dispirone in a perfume composition for enhancing the malodour reduction properties of the composition.
The invention also includes within its scope a method of enhancing the malodour reduction properties of a fragrance composition, comprising including in the composition at least one of Camonal, Cyprisate, Elintaal and Dispirone.
The present invention is concerned particularly with reduction of malodour (ie reducing the perceived intensity of a malodour) not by masking the malodour (eg dominating the malodour with a stronger odour) but by counteracting or neutralising the malodour in a way that reduces perceived malodour intensity without the need for an intense perfume, or a perfume with a pronounced idiosyncratic odour character such as eucalyptus or wintergreen: this is thought to involve some sort of blocking interaction, possibly between the chemical reagents involved, or in the nose or brain of a subject, although the mechanism is not understood.
The performance of materials in reducing malodour was measured experimentally by assessing materials on their own and in mixtures for their effectiveness in reducing (counteracting) standard malodours in small scale headspace assessments carried out by trained sensory assessors. Tests were preferably carried out using fragrance materials at similar intensity levels, ie at levels subjectively assessed by the trained assessors to have similar perceived levels of fragrance intensity (referred to herein as iso-intense fragrance levels), rather than using materials necessarily at the same amounts by weight, so that reduction in malodour is more likely to be due to malodour counteraction (either by chemical or sensory mechanisms) than to malodour masking (by a fragrance material of stronger intensity).
DETAILED DESCRIPTION OF THE INVENTION
The invention will be further described, by way of illustration, in the following Examples.
Experimental Testing Procedure
Techniques have been developed for the accurate measurement of the performance of fragrance materials and compositions against standard malodours utilising small scale headspace assessments carried out by a sensory panel of trained sensory assessors.
The Sensory Panel
The sensory panel consists of a pool of between 25 and 35 members, who are all screened and then trained over a period of 6 months. Training includes learning to identify individual odour characters in complex mixtures, and to score their perceived intensity using a ratio scoring technique (Magnitude Estimation). The level of efficiency of the panel is continuously monitored to ensure a high level of accuracy and reproducibility.
Testing Environment
During testing all variables other than those actually under test are controlled as carefully as possible. Samples are always prepared so that they are, as far as possible, identical apart from their differences in odour. When presented to panellists they are presented in random order and given random 3-figure codes. A minimum of 28 assessments were collated for each sample.
All assessments reported in the examples were carried out in a purpose built panel suite. The suite is designed so that all external distractions (ie. odour, noise, movement) are eliminated, and the panellists are not distracted during testing.
Sample Preparation
The perfume material and malodour are placed alongside each other in a 500 ml glass vessel: 3 ml of malodour in a squat 15 ml jar alongside a perfume material (1 ml in a 15 ml upright jar). The vessel is closed and allowed to equilibrate for half an hour before assessment.
The Malodour
The malodours are selected for practical usefulness. Standard malodours have been identified which would be suitable. In these examples a bathroom malodour was used.
Sensory Assessment
Each panel member assesses each sample for the intensity of malodour and perfume material that can be perceived in the headspace of the glass vessel. Hidden blanks (malodour but no perfume) are included as internal controls. The scores for each of the panellists are normalised and averaged to give a consensus score across the whole panel.
Standard statistical techniques are employed to compare the performance of each perfume material against the malodour and the statistical significance of any differences detected. A performance value for each ingredient when tested in mixtures was calculated using the general linear models procedure (PROC REG) of the Statistical Analysis System (SAS). The SAS system is an integrated system of software developed by the SAS Institute Inc, SAS Campus Drive, Cary, N.C. 27514,USA. SAS is a registered Trade Mark. The REG procedure is a general purpose procedure fitting linear regression models by the method of least squares.
EXAMPLE 1
Single Ingredient Testing
In preliminary experiments various materials, including Camonal, Cyprisate, Elintaal and Dispirone, were tested singly and in various mixtures against the standard bathroom malodour. The materials other than Camonal, Cyprisate, Elintaal and Dispirone were included for comparative purposes.
Each ingredient was diluted with diethylphthalate (DEP) to a concentration which gave a fragrance intensity assessed by the panellists as similar to that of the intensity of a 0.5% dilution of standard bathroom malodour. The use of similar intensity fragrance levels reduces the risk of any occurrence of masking of malodour by the fragrance. Any reduction of malodour found is therefore likely to arise from malodour counteraction, by either chemical or sensory mechanisms.
Fragrance materials tested were as follows:
Concentration in DEP
Elintaal
100%
Cyprisate
50%
Camonal
25%
Dispirone
50%
Animalis
10%
Damascone alpha
60%
Hexyl cinnamic aldehyde
100%
Dimethyl hydroquinone
50%
All the ingredients tested in the. protocol described above gave malodour intensity scores in the range 30 to 59 (on a scale of 0 to 100), and so were classified as medium malodour couteractants as single ingredients.
The results of the fragrance materials tested are as follows:
Ingredient
Malodour Score
Classification
Elintaal
45.0
Medium
Cyprisate
51.4
Medium
Camonal
36.6
Medium
Dispirone
33.4
Medium
Animalis
32.0
Medium
Damascone alpha
34.2
Medium
Hexyl cinnamic aldehyde
36.0
Medium
Dimethyl hydroquinone
30.0
Medium
The results show reduction of malodour from 70% to 49% by the ingredients. These ingredients therefore have some ability to reduce malodour as individual chemicals, but are not as good as some known materials. On this basis, these materials have been arbitrarily classed as having medium malodour reduction ability.
Mixture Testing
Each of the ingredients were also tested in 6 component mixes. The mixes were used to simulate possible inter-ingredient interactions caused by mixing into complex formulations. The ingredients were diluted to iso-intense levels prior to mixing. Each ingredient was incorporated into at least 6 different mixtures. Each mixture contained equal weight to weight ratios of the 6 iso-intense ingredients.
The mixtures were tested using the same testing procedure described above.
Parameter estimates were calculated using the PROC REG procedure in the SAS system. This is a general-purpose procedure fitting linear regression models by least squares. The parameter estimates for each ingredient in the mixtures were adjusted according to the concentration of the ingredient in the mixtures, and were then added together along with the calculated intercept. This gave predicted performance values for the single fragrance materials when incorporated into mixtures.
Results
The predicted values (predicted malodour score in the table below) obtained for the fragrance ingredients fell on a scale of −60 to +40. This slight change of scale occurs as a result of the statistical procedure followed. The results can be classified as shown below:
Group 1:
Good malodour counteractants in mixtures
−60 to 0
Group 2:
Medium malodour counteractants in mixtures
0 to 40
Group 3:
Poor malodour counteractants in mixtures
>40
The results for the fragrance materials tested are as follows:
Ingredient
Predicted malodour score
Classification
Elintaal
−16.8
Good
Cyprisate
−27.8
Good
Camonal
−50.0
Good
Dispirone
−1.4
Good
Animalis
61.0
Poor
Damascone alpha
62.8
Poor
Hexyl cinnamic aldehyde
57.4
Poor
Dimethyl hydroquinon
68.8
Poor
The results show that the top 4 ingredients perform surprisingly well in mixtures, better than would have been expected from their single ingredients scores.
This surprising action of the ingredients unexpectedly enhances the performance of the mixtures in which they were tested. This unexpected action is as a result of synergism. This effect applies to Elintaal, Cyprisate, Carnonal and Dispirone only, and not the other materials tested in this experiment.
Confirmation of Synergistic Action
The four synergistic materials, Elintaal, Cyprisate, Camonal and Dispirone, were diluted to iso-intense levels and then mixed together in equal weight to weight ratios to form a simple synergistic base. This base was dosed into a neutral fragrance referred to as Chester, the formulation of which is given below, at a range of levels. The resulting mixes were tested against malodour using the method detailed previously.
Formulation of Neutral fragrance Chester:
Ingredient
wt %
Benzyl salicylate
5
Cinnamic alcohol
0.25
DEP
50
Dihydromyrcenol
5
Diphenyl oxide
2.5
Heliotropin
1
Hydroxycitronellal
5
Indole
0.1
Lily aldehyde
5
Linalol
5
Lixetone
2.5
Methyl anthranilate
0.5
Methyl ionone alpha iso
1.5
Terpineol
16.6
Vanilin
0.05
The results are shown below
Malodour
Fragrance
Intensity
Sample
Intensity
Sample
10
Chester + 50% syn
a
86
Chester + 30%
a
mix
syn mix
11
Chester + 40% syn
a
83
Chester + 40%
a
mix
syn mix
17
Chester + 30% syn
79
Chester + 50%
a
mix
syn mix
20
Chester + 20% syn
b
76
Chester + 20%
b
mix
syn mix
30
Chester
b
67
Chester
b
100
Malodour only
0
Malodour only
Please note: The samples with the same character (a or b) alongside are NOT significantly mix, different.
The results show that dosing in to Chester of 30% or more of the synergistic mix, significantly improves the performance of the neutral fragrance against bathroom malodour.
EXAMPLE 2
In further experiments, further similar tests were carried out using Camonal, Cyprisate, Dispirone and Elintaal singly at different concentrations and for different combinations of the 4 ingredients. The ingredients were tested dosed into Chester (which includes 50% DEP) against bathroom malodour.
Samples Tested
The four ingredients were diluted to iso-intense levels before dosing into Chester at the following levels.
Single ingredients:
Camonal
1%, 5%, 10%, 30%
Cyprisate
1%, 5%, 10%, 30%
Elintaal
10%, 15%, 20%, 30%
Dispirone
5%, 10%, 20%, 30%
Equal ratio mixtures of the following iso-intense ingredients dosed into Chester at 10%:
1:1
Camonal:Elintaal
1:1
Camonal:Cyprisate
1:1
Camonal:Dispirone
1:1
Cyprisate:Elintaal
1:1
Cyprisate:Dispirone
1:1
Elintaal:Dispirone
1:1:1
Cyprisate:Camonal:Elintaal
1:1:1
Camonal:Elintaal:Dispirone
1:1:1
Cyprisate:Elintaal:Dispirone
1:1:1
Cyprisate:Camonal:Dispirone
2:1
Camonal:Cyprisate
2:1
Camonal:Elintaal
2:1
Camonal:Dispirone
2:1
Cyprisate:Elintaal
2:1
Cyprisate:Disprione
2:1
Elintaal:Camonal
2:1
Elintaal:Cyprisate
2:1
Dispirone:Elintaal
NB: Iso-intense levels of the ingredients are shown as follows:
Camonal (25%)
Cyprisate (50%)
Dispirone (50%)
Elintaal (100%)
For purposes of clarification, Appendix 1 gives details of % of ingredients, DEP and fragrance used in the mixtures.
Method
A standard procedure described above was used. 1 ml of fragrance mixture was pipetted into 15 ml jars and placed into 500 ml vessels alongside 15 ml jars containing 3 ml of bathroom malodour at 0.5%. The vessels were sealed and allowed to come to equilibrium before assessment by a trained sensory panel using the technique of magnitude estimation.
Results
Testing of single ingredients dosed into Chester
Each of the four iso-intense ingredients was firstly tested dosed into Chester at 10% and 30%.
Sample
Malodour
Intensity
8
Chester + 30% Camonal
abc
12
Chester + 10% Camonal
abcd
13
Chester + 10% Cyprisate
abcd
13
Chester + 30% Cyprisate
bcd
18
Chester + 10% Dispirone
bcde
19
Chester + 30% Elintaal
cde
23
Chester + 10% Elintaal
def
26
Chester + 30% Dispirone
efg
35
Chester
fg
62
Malodour only
Fragrance
Intensity
89
Chester + 30% Camonal
a
82
Chester + 30% Cyprisate
a
79
Chester + 10% Cyprisate
ab
78
Chester + 10% Camonal
abc
66
Chester + 10% Dispirone
bcd
64
Chester + 30% Elintaal
cd
63
Chester + 10% Elintaal
d
57
Chester + 30% Dispirone
de
46
Chester
e
12
Malodour only
Please note: The samples with the same character alongside are NOT significantly different.
The results show that:
1. Addition of either 10% or 30% of Camonal or Cyprisate has significantly improved the performance of Chester.
2. Addition of 30% of Elintaal has significantly improved the performance of Chester. A significant improvement is not seen with 10% of Elintaal.
3. Significant improvement of Chester is seen with 10% of Dispirone, but not with 30%. This maybe as a result of the unpleasant aspect of Dispirone odour when at higher concentration levels. This unpleasantness may be seen to add to the malodour intensity.
Following on from these results, Camonal and Cyprisate were tested again at lower dosage levels, Elintaal at levels between 10 and 30%, and Dispirone also at lower levels.
Sample
Malodour
Intensity
4
Chester + 10% Camonal
ab
6
Chester + 1% Cyprisate
ab
6
Chester + 10% Cyprisate
ab
6
Chester + 5% Camonal
ab
9
Chester + 15% Elintaal
abc
10
Chester + 5% Cyprisate
abc
10
Chester + 30% Elintaal
abc
11
Chester + 20% Elintaal
abc
12
Chester + 1% Camonal
bc
20
Chester + 5% Dispirone
cd
24
Chester + 10% Dispirone
de
35
Chester + 20% Dispirone
ef
41
Chester
f
93
Malodour only
Fragrance
Intensity
102
Chester + 10% Camonal
ab
97
Chester + 1% Cyprisate
abc
94
Chester + 5% Cyprisate
abc
93
Chester + 10% Cyprisate
abc
93
Chester + 5% Camonal
abc
86
Chester + 20% Elintaal
cd
85
Chester + 30% Elintaal
cd
84
Chester + 15% Elintaal
cd
78
Chester + 1% Camonal
de
68
Chester + 10% Dispirone
ef
59
Chester + 5% Dispirone
fg
55
Chester + 20% Dispirone
fg
50
Chester
g
0
Malodour only
Please note: The samples with the same character alongside are NOT significantly different.
The results show that:
1. For Camonal, there is no significant difference between dosing in 1%, 5% or 10%.
As concentration increases there is a directional improvement in the fragrance performance.
2. For Cyprisate, there is no significant difference between dosing in 1%, 5% or 10%.
3. For Elintaal, there is no significant difference between dosing in 15%, 20% or 30%.
4. For Dispirone, dosing in 10% or 5% significantly improved the performance of improvement is not seen with 20% Dispirone.
Testing of 1:1 and 1:1:1 mixes of ingredients dosed into Chester
Sample
Malodour
Intensity
4
Chester + 1:1 Cam:El
ab
7
Chester + 1:1:1 Cy:Cam:El
ab
7
Chester + 1:1:1 Cam:El:Dis
ab
8
Chester + 1:1 Cy:Cam
ab
11
Chester + 1:1 Cam:Dis
ab
12
Chester + 30% Elintaal
ab
13
Chester + 10% Cyprisate
ab
14
Chester + 1:1:1 Cy:El:Dis
ab
17
Chester + 15% Camonal
b
17
Chester + 1:1:1 Cy:Cam:Dis
b
17
Chester + 1:1 Cy:El
b
33
Chester + 1:1 El:Dis
c
35
Chester + 1:1 Cy:Dis
c
43
Chester
c
93
Malodour only
Fragrance
Intensity
90
Chester + 1:1 Cam:El
bc
81
Chester + 1:1:1 Cy:Cam:El
cd
81
Chester + 30% Elintaal
cd
80
Chester + 1:1 Cy:Cam
cd
79
Chester + 1:1:1 Cam:El:Dis
cd
77
Chester + 10% Cyprisate
cd
76
Chester + 15% Camonal
cd
76
Chester + 1:1 Cam:Dis
cd
73
Chester + 1:1 Cy:El
d
71
Chester + 1:1:1 Cy:El:Dis
de
65
Chester + 1:1:1 Cy:Cam:Dis
def
56
Chester + 1:1 Cy:Dis
efg
48
Chester
fg
46
Chester + 1:1 El:Dis
g
0
Malodour only
Please note: The samples with the same character alongside are NOT significantly different.
The results show that:
1. Of the mixtures tested, all performed significantly better than Chester except 1:1 Elintaal Dispirone and 1:1 Cyprisate:Dispirone.
2. There were no significant differences seen between the good performing mixtures.
3. Directional differences were seen in the results which can be summarised as follows:
Mixtures containing Camonal and Elintaal performed best
1:1 mixtures containing Dispirone performed badly except when Camonal was the other ingredient.
1:1:1 mixtures all performed well even if they contained Dispirone
1:1 mixtures containing Cyprisate performed well except with Dispirone.
Testing of 2:1 mixtures of ingredients dosed into Chester
Sample
Malodour
Intensity
4
Chester + 2:1 Cam:Cy
abcd
5
Chester + 2:1 Cam:El
abcd
10
Chester + 2:1 Cy:Cam
abcde
11
Chester + 2:1 Cy:El
abcde
17
Chester + 2:1 Cy:Dis
bcde
18
Chester + 2:1 Cam:Dis
cde
21
Chester + 2:1 El:Cam
de
22
Chester + 2:1 El:Cy
e
42
Chester
f
44
Chester + 2:1 Dis:El
f
79
Malodour only
Fragrance
Intensity
86
Chester + 2:1 Cam:El
a
85
Chester + 2:1 Cam:Cy
a
80
Chester + 2:1 Cy:Cam
ab
78
Chester + 2:1 Cam:Dis
ab
77
Chester + 2:1 Cy:El
abc
66
Chester + 2:1 Cy:Dis
bcd
59
Chester + 2:1 El:Cam
cd
57
Chester + 2:1 El:Cy
d
39
Chester + 2:1 Dis:El
e
35
Chester
e
2
Malodour only
Please note: The samples with the same character alongside are NOT significantly different.
The results show that:
1. Of the mixtures tested, all performed significantly better than Chester except 2:1 Dispirone Elintaal.
2. There are few significant differences seen between the good performing mixes.
3. Directional differences were seen in results which can be summarised as follows:
Mixtures with Cyprisate or Carnonal in the greatest proportion performed best.
The 2:1 Camonal:Cyprisate performed better than 2:1 Cyprisate:Camonal
While the synergistic ingredients can be used at any level, the following provides recommendations for levels which can lead to significant synergistic benefit.
Use of the four ingredients are as follows. All recommendations refer to use of ingredients at iso-intense levels.
Singly:
Preferably use as follows:
Camonal—use at 1% or more. The higher the concentration the better the effect directionally.
Cyprisate—use at 1% or more. Concentration does not seem to affect performance.
Elintaal—use at 15% or more. Concentration above 15% does not seem to affect performance.
Dispirone—use at 5%-10%. Use of more than 10% adds to the malodour perception. due to the unpleasant smell of Dispirone at high levels.
Mixtures:
While no performance advantage is seen using mixtures of the four ingredients opposed to use singly, there is, however, a hedonic advantage in using mixtures as this allows a wider variety in fragrance hedonics to be produced with the same performance levels.
Mixtures containing 1:1:1 ratios of three of the ingredients perform well in all combinations.
Mixtures containing 1:1 ratios of the ingredients must contain Camonal or Cyprisate for good performance.
Mixtures containing 1:1 ratios of Dispirone with an other ingredient should be avoided unless Camonal is used.
Mixtures containing 2:1 ratios of ingredients perform best with either Camonal or Cyprisate as the highest proportion ingredient.
Appendix 1
% for Single dosing-in mixtures:
Mixture
% Ingredient
% DEP
% Fragrance
Chester + 1% Camonal
0.25
0.75
99
Chester + 5% Camonal
1
4
95
Chester + 10% Camonal
2.5
7.5
90
Chester + 30% Camonal
7.5
22.5
70
Chester + 1% Cyprisate
0.5
0.5
99
Chester + 5% Cyprisate
2.5
2.5
95
Chester + 10% Cyprisate
5
5
90
Chester + 30% Cyprisate
15
15
70
Chester + 10% Elintaal
10
0
90
Chester + 15% Elintaal
15
0
85
Chester + 20% Elintaal
20
0
80
Chester + 30% Elintaal
30
0
70
Chester + 5% Dispirone
2.5
2.5
95
Chester + 10% Dispirone
5
5
90
Chester + 20% Dispirone
10
10
80
Chester + 30% Dispirone
15
15
70
% for 1:1 mixtures
% first
% second
Mixture
ingredient
ingredient
% DEP
% Fragrance
Chester + 1:1 Cam:El
1
5
4
90
Chester + 1:1 Cam:Cy
1
2.5
6.5
90
Chester + 1:1 Cam:Dis
1
2.5
6.5
90
Chester + 1:1 Cy:El
2.5
5
2.5
90
Chester + 1:1 Cy:Dis
2.5
2.5
5
90
Chester + 1:1 El:Dis
5
2.5
2.5
90
% for 1:1:1 mixtures
% first
% second
% third
%
%
Mixture
ingredient
ingredient
ingredient
DEP
Fragrance
Chester + Cy:
1.67
0.83
3.33
4.14
90
Cam:El
Chester + Cam:
0.83
3.33
1.67
4.14
90
El:Dis
Chester + Cy:El:
1.67
3.33
1.67
3.33
90
Dis
Chester + Cy:
1.67
0.83
1.67
5.83
90
Cam:Dis
% for 2:1 mixtures
% main
% secondary
Mixture
ingredient
ingredient
% DEP
% Fragrance
Chester + 2:1 Cam:Cy
1.66
1.67
6.66
90
Chester + 2:1 Cam:El
1.66
3.33
5.01
90
Chester + 2:1 Cam:Dis
1.66
1.67
6.66
90
Chester + 2:1 Cy:El
3.33
3.33
3.33
90
Chester + 2:1 Cy:Dis
3.33
1.67
5.00
90
Chester + 2:1 El:Cam
6.66
0.83
7.49
90
Chester + 2:1 El:Cy
6.66
1.67
8.33
90
Chester + 2:1 Dis:El
3.33
6.66
9.96
90 | A fragrance composition comprising a mixture of at least two of the following:
5-methyl-2-(2-methylpropyl-1,3-dioxane (Camonal);
methyl 1,4-dimethylcyclohexylcarboxylate (Cyprisate);
3-(((1-ethoxy)ethyl)oxy)-3,7-dimetyl-1,6-octadiene (Elintaal); and
7,9-dimethylspiro(5,5)undcan-3-one (Dispirone)
and use thereof to provide enhanced malodour reduction. | 2 |
BACKGROUND
[0001] A foldable habitation allowing an owner to fold the habitation from an unfolded state to a folded state, to move it to another location, or for storage, is presented in published international patent application no. WO 02/066755. Such a foldable habitation can provide a cottage which can be displaced from year to year or an office which can be installed on a temporary construction site, for example, to give two of the numerous possibilities it offers. It can be folded into a compact folded state for displacement and be unfolded and deployed to satisfy dwelling needs.
[0002] Although the foldable habitation discussed above has been found satisfactory on many aspects, there remained room for even further improvements.
SUMMARY
[0003] In accordance with one aspect, there is provided a foldable habitation comprising: a base having an elongated central floor portion with a front end and a rear end; a frame having a front portion secured to and vertically extending from the front end of the central floor portion, a rear portion secured to and vertically extending from the rear end of the central floor portion, and an upper portion connecting the front portion and the rear portion, the frame being capable of supporting the weight of the foldable habitation when the foldable habitation is lifted by the front portion and the rear portion of the frame; and a covering having a central roof portion mounted to the upper portion of the frame.
[0004] In accordance with another aspect, there is provided a foldable habitation comprising: a base having an elongated central floor portion, generally oriented in a longitudinal orientation, having a front end, a rear end, and two opposite sides, the base also having two lateral floor portions, each lateral floor portion being hingedly mounted along a respective one of the opposite sides of the central floor portion; a frame having a front portion secured to and vertically extending from the front end of the central floor portion, a rear portion secured to and vertically extending from the rear end of the central floor portion, and an upper portion connecting the front portion and the rear portion; a covering having a central roof portion mounted to the upper portion of the frame and having two opposite sides, and two lateral roof portions, each lateral roof portion being hingedly mounted along a respective one of the opposite sides of the central roof portion; two opposite lateral walls, each lateral wall having a front end and a rear end and being slidable in a transversal orientation along a corresponding one of the lateral floor portions; and a front wall and a rear wall, each having a central wall portion mounted to a respective one of the front portion and the rear portion of the frame and having two opposite sides, and two foldable lateral portions, each lateral portion being hingedly mounted between a respective one of the opposite sides of the central wall portion and a respective one of the front end and the rear end of a respective one of the two lateral walls, the lateral portions being configured and adapted to unfold when the corresponding lateral wall is outwardly slid.
[0005] In accordance with another aspect, there is provided a foldable habitation having a foldable base including an elongated central floor portion having a front end and a rear end, a foldable covering including a central roof portion, and deployable walls, the foldable habitation being characterized in that it further has a supporting frame having a plurality of interconnected steel beams, the frame having a front portion secured to and vertically extending from the front end of the central floor portion, a rear portion secured to and vertically extending from the rear end of the central floor portion, and an upper portion connecting the front portion to the rear portion of the frame and to which the central roof portion of the covering is mounted.
[0006] In accordance with another aspect, there is provided a method of handling a foldable habitation in a folded configuration, the method comprising: removably fastening a front leverage beam to an upper end of a front portion of a steel frame of the foldable habitation; removably fastening a rear leverage beam to an upper end of a rear portion of the steel frame of the foldable habitation; and lifting the foldable habitation using the fastened front and rear leverage beams.
[0007] In accordance with one aspect, there is provided a foldable habitation that can be unfolded and deployed to satisfy dwelling needs, and that can be folded into a compact configuration for displacement or storage, for example. The foldable habitation has a base with an elongated central floor portion, a frame secured to and vertically extending from the central floor portion, and a covering having a central roof portion mounted to the upper portion of the frame. The foldable habitation can be provided as a cottage unit which can be displaced from year to year, a movable motel unit, or an office unit which can be installed on a temporary construction site, to give three examples of the numerous possibilities.
DESCRIPTION OF THE FIGURES
[0008] Further features and advantages will become apparent from the following detailed description, taken in combination with the appended figures, in which:
[0009] FIG. 1 is a perspective view of an example of an improved foldable habitation in a folded state;
[0010] FIG. 2 is a view similar to FIG. 1 showing unfolding of the lateral floor portions;
[0011] FIG. 3 is a view similar to FIG. 1 showing unfolding of the lateral roof portion on one side;
[0012] FIG. 4 is a view similar to FIG. 1 showing unfolding of the walls on one side;
[0013] FIG. 5 is a view similar to FIG. 1 , with one side completely deployed, showing unfolding of a lateral roof portion on another side;
[0014] FIG. 6 is a perspective view of the improved foldable habitation of FIG. 1 in an unfolded state;
[0015] FIG. 7 is a view similar to FIG. 6 with the covering removed;
[0016] FIG. 8 is a perspective view of the frame of the foldable habitation of FIG. 1 ;
[0017] FIG. 9 is an enlarged view of a portion of FIG. 4 , showing the lateral wall sliding transversally;
[0018] FIG. 10 is an enlarged view, fragmented, of the front or rear portions of the frame of FIG. 8 , with components removed, and with a leverage beam fastened thereto;
[0019] FIG. 11 is a perspective view of the foldable habitation of FIG. 1 adapted to be lifted by a crane.
DETAILED DESCRIPTION
[0020] FIG. 1 shows an example of an improved foldable habitation 10 in a folded state. In the folded state, the foldable habitation has an elongated appearance in an orientation referred to herein as the longitudinal orientation, schematized by a longitudinal axis 11 . The main components of the foldable habitation 10 are substantially symmetrical along a median longitudinal plane. For the sake of clarity, a front end 12 and the rear end 14 of the foldable habitation are defined, though it will be understood that a front door of the foldable habitation can be provided in a wall referred to herein as a lateral wall or rear wall, for example. Due to the symmetricallity of the foldable habitation 10 , the front end 12 and the rear end 14 are similar. Only one side of the foldable habitation thus needs to be discussed in detail. For simplicity, when two similar components are present on opposite sides of the foldable habitation 10 , only one of the two similar components is referred to using a reference numeral.
[0021] The foldable habitation 10 includes a base 16 having an elongated central floor portion 18 oriented in the longitudinal orientation 11 , and two lateral floor portions 20 . Each lateral floor portion 20 is hingedly mounted to pivot around a corresponding longitudinal side 30 of the central floor portion 18 . The foldable habitation 10 also has a covering 24 , the covering 24 includes a central roof portion 26 oriented in the longitudinal orientation 11 , and two lateral roof portions 28 . Similarly, the two lateral roof portions 28 are hingedly mounted along two opposite sides of the central roof portion 26 . The foldable habitation 10 also has two opposite lateral walls 32 . In the folded state, each lateral roof portion 28 is nested between a corresponding lateral floor portion 20 and a corresponding lateral wall 32 . The foldable habitation also has a front wall 34 and a rear wall (not shown). The front wall 34 has a central wall portion 36 having two opposite sides 38 , and two folded lateral portions 40 . Each one of the two folded lateral portions 40 is hingedly mounted between a corresponding opposite side 38 of the central wall portion 36 and a corresponding lateral wall 32 . The rear wall (not shown) is similar to the front wall 34 .
[0022] Reference will now be made to FIGS. 1 to 6 to show successive steps for unfolding the foldable habitation 10 from the folded state into an unfolded or deployed state. These steps can be carried out in the reverse order to fold the foldable habitation 10 .
[0023] In FIG. 1 the foldable habitation 10 is in the folded state. In FIG. 2 , the foldable habitation 10 is shown positioned onto height-adjustable bearing members, jacks 42 in this case, and the lateral floor portions 20 are being unfolded by hingedly pivoting around the corresponding side 30 of the central floor portion 18 . In FIG. 3 , the base 16 is deployed. A lateral roof portion 28 is being raised by hingedly pivoting along a respective side of the central roof portion 26 . In FIG. 4 , a lateral wall 32 is being slid transversally along a corresponding lateral floor portion 20 , which results in unfolding a corresponding lateral portion 40 of the front wall 34 . The lateral portion 40 of the front wall 34 includes two wall panels 44 , 46 , which are hingedly connected together along their adjacent sides. The inner wall panel 44 has an inner side hingedly connected to a corresponding side 38 of the central portion 36 of the front wall 34 , and the outer wall panel 46 has an outer side hingedly connected to a front end of the lateral wall 32 . A lateral portion of the rear wall (not shown) is similarly unfolded at the rear of the foldable habitation 10 as the lateral wall 32 is transversally slid. In FIG. 5 , one side of the foldable habitation 10 is shown unfolded, and the other side is being deployed by raising the lateral roof portion 28 . The lateral wall of that other side, and the corresponding lateral portions of the front and rear walls, will then be deployed such as depicted in FIG. 4 . In FIG. 6 , the foldable habitation is shown in an unfolded state. A chimney 48 can also be present on the front wall 34 .
[0024] In FIG. 7 , the foldable habitation 10 is shown with the covering 24 removed. A steel beam frame 50 of the foldable habitation 10 is shown. Partitions 52 , 54 were unfolded subsequently to deployment of the lateral walls 32 . Cupboards were affixed to one partition 54 , corresponding to a kitchen area. Furniture can then be added to the foldable habitation as desired.
[0025] The example of a foldable habitation 10 described above and illustrated corresponds to a cottage unit offering a panoramic view at the front due to the presence of numerous large windows on the front wall. In alternate embodiments, the configuration of the partitions, windows, and doors, can greatly depart from those illustrated to adapt the foldable habitation to other uses. An office unit where the partitions are removed or minimized, and a motel unit longitudinally separated in two halves and having two front doors, and two bathrooms, one accessible from each half, are two of the numerous examples of other uses. Many additional configurations and uses are also possible.
[0026] For illustrative purposes, the illustrated model has 7.3 m (24 feet) in length and 6.7 m (22 feet) in width when it is in the unfolded state. When it is folded, it can be folded down to 2.6 m (8 feet and 7 inches) in width, which is an advantageous width when exporting overseas because it allows shipping in standard size shipping containers. In alternate configurations, various other lengths and widths are also possible.
[0027] A factor which has been known to limit the practicable length of previously known foldable habitations was the important longitudinal deflection, caused by the weight of the components, which has been known to occur when such folded habitations were lifted to be put onto a trailer or into a container, for example. This was a source of many handling difficulties, and in some cases, lifting required the installation of an outer frame for the folded habitation, like an exoskeleton, to provide a lifting structure to limit the longitudinal deflection during lifting.
[0028] One element which is very advantageous in the illustrated example of an improved foldable habitation 10 is the incorporation of an internal frame 50 . The incorporation of an internal frame allows to alleviate many of the aforementioned handling difficulties known to some previously known foldable habitations by providing a longitudinal deflection-resistant structure. This can advantageously help in limiting the longitudinal deflection in the components of the foldable habitation, thus easing the manipulation of foldable habitations and allowing to provide foldable habitations of increased length as compared to what could previously be achieved. For example, using a frame of steel beams, it is now possible to produce and handle a foldable habitation having 10.3 m (34 feet) in length, and potentially more.
[0029] FIG. 8 shows the steel frame 50 of the foldable habitation 10 shown and described above. The steel frame 50 has an upper portion 52 to which the central roof portion 26 is mounted, and a front portion 54 and a rear portion 56 to which the central portions 36 of the front wall 34 and of the rear wall are mounted, respectively. The front portion 54 and the rear portion 56 are secured to, and vertically extend, from the front end and the rear end of the central floor portion 18 , respectively. The upper portion 52 of the frame 50 is assembled to the upper ends of the front portion 54 and the rear portion 56 of the frame 50 .
[0030] In this example, a front brace 58 and a rear brace 60 are provided as part of the front portion 54 and the rear portion 56 , respectively. The braces 56 , 58 each have a fixed central portion 62 fastened along the corresponding one of the front or rear end of the central floor portion 18 . For illustrative purposes, it will be understood that the central floor portion 18 and lateral floor portions 20 are constructed with an internal structure, and the central floor portion 18 , for example, can have structural members extending along both transversally opposite sides 30 . These side structural members are connected at opposite ends to the central portion 62 of the braces 56 , 58 . The use of fixed central portions 62 of braces 56 , 58 for securing the frame 50 to the central floor portion 18 advantageously allows to spread the retention forces along the width of the central floor portion 18 when the foldable habitation 10 is lifted. In alternate configurations, the frame can be connected to the floor differently.
[0031] The braces 56 , 58 in this example, also include two lateral brace portions 64 , each being hingedly connected to a corresponding end of the central brace portion 62 . This particular configuration is optional, but advantageously allows to provide the hinged connection between the lateral floor portions 20 and the central floor portion 18 as part of the frame 50 . The use of braces 56 , 58 can also contribute to add structure to the lateral floor portions 20 , which can be helpful in leveling the habitation 10 .
[0032] Certain conventional wood structures have a tendency to deform with time due to warping of the wood boards during temperature variations, or aging. A metal frame can advantageously overcome these limitations of wood structures because they are more stable with time. Further, providing the metal frame internally allows to somewhat minimize the remaining deformation, or relative displacement, which can occur in the components which are mounted to the frame.
[0033] In this example, the upper portion 52 of the frame 50 includes two longitudinally oriented and transversally spaced-apart I-beams 66 . I-beams advantageously provide an important amount of longitudinal deflection resistance to the frame 50 and can advantageously be manufactured in various lengths and sizes. It will be understood that beams having other cross-sectional shapes than I-beams, but also offering satisfactory longitudinal deflection characteristics can alternately be used. The particular size of I-beams for a particular foldable habitation application can be calculated by persons of ordinary skill in the art for a given overall weight, and weight distribution, of a particular embodiment of a foldable habitation. The two parallel I-beams 66 are transversally interconnected by a plurality of struts 68 . In the illustrated example, all the components of the frame 50 are made of steel, although components of other metals can also be used. In alternate embodiments, different configurations of can alternately be used for the upper frame portion 52 .
[0034] In this example, the front portion 54 and the rear portion 56 of the frame 50 are similar, and both include two vertical beams 70 , or studs, each one of the studs extending downwardly from a respective one of the two I-beams 66 . Alternate configurations can also be used.
[0035] In this example, the frame 50 is further reinforced by an optional intermediate portion 72 also having two vertical beams 74 , or studs, and a transversal floor beam 76 . The intermediate portion 72 serves to suspend an intermediate portion of the central floor portion 18 to the upper portion 52 of the frame 50 . This advantageously allows to reduce longitudinal deflection in the central floor portion 18 . In alternate configurations, the intermediate portion 72 can be omitted, or additional intermediate portions can be added, to adapt the frame to different lengths of foldable habitations, or to different weight and deflection characteristics of the foldable habitation components, for example.
[0036] Referring now to FIG. 9 , to ease the transversal sliding of the lateral walls 32 of the foldable habitation when folding or unfolding, the lateral walls 32 can be supported on wheels or rollers. In this example, a transversally oriented wheel 80 is provided at each longitudinal end of the lateral wall 32 . The front brace 58 , and more particularly the lateral brace portions 64 thereof, are provided with guiding tracks 82 for the wheel 80 . Guiding tracks are optional, but can advantageously be used to help maintaining the longitudinal alignment of the lateral walls during the transversal sliding displacement. The guiding tracks can advantageously be provided on either one of the front end and the rear end of the lateral floor portions 20 rather than being provided on both the front end and the rear end, because using two opposite guiding tracks can lead to blockage of the lateral wall 32 if obliqueness occurs during the transversal sliding displacement, such as if one end of the lateral wall 32 is moved faster than the opposite end. Providing guiding tracks made of metal is advantageous because it provides a hard surface on which the wheel 80 can be easily slid. This hard surface is durable and helps maintain the foldability of the habitation 10 over time. In embodiments where lateral brace portions 64 are used, the guiding track 82 can advantageously be provided as part of the frame 50 . The guiding tracks 82 can thus be automatically aligned with the central floor portion 18 . Further, providing the guiding track 82 as part of the lateral brace portion 64 offers deformation resistance over time.
[0037] In this example, the guiding track 82 has a vertically-extending male portion 84 extending along the upper side of the lateral brace portion 64 , and the wheel 80 has a circumferential female groove 86 adapted to receive the male portion 84 of the guiding track 82 . The use of the male portion in the guiding track rather than in the wheel is advantageous because the vertically-extending male portion contributes to impede infiltration of water from the outside.
[0038] FIG. 10 shows that the studs 70 of the front portion 54 or rear portion 56 of the frame 50 can advantageously have threaded apertures 88 defined in an upper end portion thereof. The fastener-receiving apertures 88 can receive fasteners used for securing a leverage beam 90 directly to the frame 50 . The threaded apertures 88 thus act as fixation points, or lifting areas of the frame 50 . The fasteners used to fasten the leverage beams to the frame 50 collectively support the entire weight of the foldable habitation 10 when it is lifted. The positioning of the threaded apertures 88 close to the upper portion 52 of the frame 50 is advantageous because it allows to distribute the lifting force to the upper portion 52 of the frame 50 with a relatively small moment of force between the front portion 54 or rear portion 56 and the upper portion 52 because of the relatively small distance, or lever arm, between the threaded apertures 88 and the upper portion 52 .
[0039] FIG. 11 , shows an example of how the foldable habitation 10 can be lifted. A front leverage beam 89 is secured to the front end 12 of the foldable habitation 10 , and more particularly to the frame 50 thereof, whereas a rear leverage beam 90 is secured to the rear end 14 . The front and rear leverage beams 89 , 90 can advantageously be hooked upon at opposite ends thereof, to raise the entire foldable habitation 10 for manipulation and displacement. As discussed above, manipulating the foldable habitation 10 in this manner is especially advantageous for exporting overseas, or when shipping by train, in which cases the foldable habitation 10 can be raised and placed into a shipping container. When shipping or moving by truck, the foldable habitation can also be placed on a truck bed by jacking, for example.
[0040] As can be seen therefore, the examples described above and illustrated are intended to be exemplary only. The scope of the invention(s) is intended to be determined solely by the appended claims. | The foldable habitation can be unfolded and deployed to satisfy dwelling needs, and can be folded into a compact configuration for displacement or storage, for example. The foldable habitation has a base with an elongated central floor portion, a frame secured to and vertically extending from the central floor portion, and a covering having a central roof portion mounted to the upper portion of the frame. The foldable habitation can be provided as a cottage unit which can be displaced from year to year, a movable motel unit, or an office unit which can be installed on a temporary construction site, to give three examples of the numerous possibilities. | 4 |
BACKGROUND
[0001] The present invention relates generally to integrated circuit (IC) designs, and more particularly to sense amplifiers operated under Hamming distance methodology for improving performance or reducing layout areas thereof.
[0002] A differential amplifier is a circuit module that generates outputs in response to a voltage difference between various inputs. It is commonly used in IC chips, such as memory devices, for amplifying sensed data signals. The differential amplifier is typically consisted of electronic components that can be grouped into symmetric halves, each being connected to a differential input. The electronic components of the two symmetric halves need to match in their dimensions, materials and structures in order to ensure that the outputs from the differential amplifier accurately reflects the voltage difference between the inputs. As a result, the size of the differential amplifier cannot be scaled down easily because the smaller the amplifier the more susceptible it is to mismatch due to manufacturing process variations.
[0003] FIG. 1 illustrates a first distribution curve 102 of a first group of differential sense amplifiers and a second distribution curve 104 of a second group of differential sense amplifiers, which are half the size of the differential sense amplifiers in the first group. The offset voltages for each group of differential sense amplifiers are normally distributed, in which the curve 102 is more concentrated and the curve 104 is more spread out. The curves 102 and 104 show that there are more small amplifiers outside a predetermined range of input swing than the large ones. This raises reliability issues as the differential sense amplifiers are scaled down.
[0004] FIG. 2 illustrates a conventional differential sense amplifier within a layout area 202 . A new design for differential sense amplifiers has been proposed to reduce the layout area without compromising their reliability. Naveen Verma, Anantha P. Chandrakasan, “A 65 nm 8T Sub-Vt SRAM Employing Sense-Amplifier Redundancy,” IEEE International Solid-State Circuits Conference (ISSCC), pp. 64-65, February 2007. As shown in FIG. 3 , the layout area 202 is split into two halves 302 and 304 , each of which is implemented with a differential sense amplifier. Assume that the offset voltages for the large amplifier in the layout area 202 and the amplifier in the layout area 302 or 304 are normally distributed, and the probability of failure for the small amplifier is 0.001, which is translated into a z value of 3.09 in a standard normal distribution. The probability of failure for the large differential sense amplifier is therefore 0.000006, which is obtained by looking up the standard normal distribution table with a z value of 4.369, i.e., 3.09*(2) 1/2 as the large amplifier is twice bigger than the small amplifier. Although the probability of failure for one small amplifier (0.001) is higher than that for one large amplifier (0.000006), the probability of two small amplifiers failing at the same time (0.000001=0.001*0.001) is lower than the probability of failure for one large amplifier. In other words, for the same reliability level, the overall size of two small amplifiers 302 and 304 would be smaller than one large amplifier 202 .
[0005] The conventional dual sense amplifier design requires an initial testing process where all the sense amplifiers are scanned in order to select the sense amplifier with better performance from each pair of sense amplifiers. Additional registers are required for storing the status of the sense amplifiers in support of their operation. As a result, the conventional dual sense amplifier design can be quite complicated and resource-consuming.
[0006] Thus, what is needed is a simple design for differential sense amplifiers that reduces the layout areas without compromising the reliability.
SUMMARY
[0007] The present invention discloses a semiconductor device including a first sense amplifier coupled to an input for generating a first output; a second sense amplifier couple to the input for generating a second output; and a third sense amplifier coupled to the input for generating a third output, wherein a fourth output amplifying the input is generated based on combinations of logic states of the first, second and third outputs.
[0008] The construction and method of operation of the invention, however, together with additional objectives and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 illustrates graphs showing distributions of offset voltages for small and large differential sense amplifiers.
[0010] FIG. 2 illustrates a layout area in which a conventional differential sense amplifier is implemented.
[0011] FIG. 3 illustrates a layout area in which conventional dual sense amplifiers are implemented.
[0012] FIG. 4 illustrates a schematic of a differential sense amplifier in accordance with one embodiment of the present invention.
[0013] FIG. 5 illustrates a layout area in which a plurality of differential sense amplifiers operating under Hamming distance methodology are implemented in accordance with one embodiment of the present invention.
[0014] FIG. 6 illustrates a schematic of a Hamming operation circuit in accordance with one embodiment of the present invention.
[0015] FIG. 7 illustrates distributions of offset voltages for the proposed differential sense amplifiers and the conventional differential sense amplifiers.
DESCRIPTION
[0016] This invention describes a semiconductor device containing sense amplifiers operated under Hamming distance methodology for improving performance or reducing layout areas thereof. The following merely illustrates various embodiments of the present invention for purposes of explaining the principles thereof. It is understood that those skilled in the art will be able to devise various equivalents that, although not explicitly described herein, embody the principles of this invention.
[0017] FIG. 4 illustrates a schematic of a differential sense amplifier 400 in accordance with one embodiment of the present invention. The differential sense amplifier 400 includes NMOS transistors N 1 , N 2 and N 3 , PMOS transistors P 1 , P 2 , P 3 , P 4 , P 5 , P 6 and P 7 . The PMOS transistors P 3 and P 4 are connected at their sources, which are further connected to the supply voltage Vdd. The drains of the PMOS transistors P 3 and P 4 are connected to the drains of the NMOS transistors N 1 and N 2 , respectively. The sources of the NMOS transistors N 1 and N 2 are connected together with the drain of the NMOS transistor N 3 , which is further connected to ground or Vss at its source. The gates of the PMOS transistor P 3 and the NMOS transistor N 2 are connected together at a node 402 , which is connected to the drains of the PMOS transistor P 4 and the NMOS transistor N 1 . The gates of the PMOS transistor P 4 and the NMOS transistor N 1 are connected together at a node 404 , which is connected to the drains of the PMOS transistor P 3 and the NMOS transistor N 2 . The gates of the PMOS transistors P 3 and P 4 are connected via the PMOS transistor P 5 , which is controlled by an enable signal from a pad 412 . The gates of the PMOS transistors P 1 and P 2 are controlled by a control signal from a pad 410 .
[0018] Differential input signals from pads 418 and 420 are applied to the gates of the NMOS transistors N 1 and N 2 , respectively. The voltage difference between the input signals are reflected by the currents on the two parallel paths of a current mirror constructed by the PMOS transistors P 3 and P 4 , and the NMOS transistors N 1 and N 2 , which in turn generates differential outputs at the pads of 408 and 406 .
[0019] Table 1 below shows the sizes of electronic components in the differential sense amplifier 400 as they are manufactured by various generations of semiconductor processing technologies.
[0000]
TABLE 1
W/L (n90)
W/L (n65)
W/L (n45)
N1
2/0.2
2/0.18
2/0.175
N2
2/0.2
2/0.18
2/0.175
N3
1/0.15
2/0.08
2/0.042
P1
1/0.15
1.2/0.1
0.52/0.07
P2
1/0.15
1.2/0.1
0.52/0.07
P3
1/0.2
1/0.12
0.52/0.12
P4
1/0.2
1/0.12
0.52/0.12
P5
1/0.1
1.2/0.12
0.52/0.12
P6
1/0.1
1/0.1
0.52/0.07
P7
1/0.1
1/0.1
0.52/0.07
[0020] As shown in table 1, the sizes of the NMOS transistors N 1 and N 2 do not shrink much as the semiconductor processing technology advances from n 90 to n 45 . The reason is that the smaller the NMOS transistors the more susceptible they are to device mismatch due to manufacturing process variations. A serious device mismatch would cause the differential sense amplifier to fail.
[0021] FIG. 5 illustrates a differential sense amplifier unit 500 in accordance with one embodiment of the present invention. The differential sense amplifier unit 500 is comprised of three differential sense amplifiers SA- 1 , SA- 2 and SA- 3 , each of which can be designed as the schematic, for example, shown in FIG. 4 . The three differential sense amplifiers SA- 1 , SA- 2 and SA- 3 can been seen as one unit that generates a single output reflecting an amplified input. The differential sense amplifiers SA- 1 , SA- 2 and SA- 3 operate under Hamming distance methodology, in which the Hamming distance between two strings of equal length is the number of positions for which the corresponding symbols are different. Table 2 below shows a truth table of the Hamming distance operation.
[0000] TABLE 2 Total Number Total Number Hamming SA-1 SA-2 SA-3 of “1s” of “0s” Output 0 0 0 0 3 0 0 0 1 1 2 0 0 1 0 1 2 0 0 1 1 2 1 1 1 0 0 1 2 0 1 0 1 2 1 1 1 1 0 2 1 1 1 1 1 3 0 1
As shown in Table 2, each differential sense amplifier SA- 1 , SA- 2 or SA- 3 generates an output, and the Hamming output (the signal output of the unit 500 ) is determined based on combinations of the logic states of the outputs of the differential sense amplifiers SA- 1 , SA- 2 and SA- 3 . Specifically, the output of the unit 500 is equal to the majority logic states of the outputs from the differential sense amplifiers SA- 1 , SA- 2 , and SA- 3 . For example, if the output of the differential sense amplifier SA- 1 is “1,” the output of the differential sense amplifier SA- 2 is “1” and the output of the differential sense amplifier SA- 3 is “0,” the output of the unit 500 will be 1, whereas if the output of the differential sense amplifier SA- 1 is “0,” the output of the differential sense amplifier SA- 2 is “0” and the output of the differential sense amplifier SA- 3 is “1,” the output of the unit 500 will be 0. The Hamming distance truth table can be expressed by the following equation: Y=C*B+A*C+A*B+A*B*C, where Y denotes the output of the unit 500 , A the output of SA- 1 , B the output of SA- 2 , and C the output of SA- 3 .
[0022] FIG. 6 illustrates a schematic of a Hamming operation circuit 600 as an exemplar circuit implementation of the above-described three-amplifier Hamming distance operation. The circuit 600 is comprised of AND gates 602 , 604 and 606 , and an OR gate 608 . The AND gate 602 has one input terminal coupled to an output A from the differential sense amplifier SA- 1 , and another coupled to an output B from the differential sense amplifier SA- 2 . The AND gate 604 has one input terminal coupled to the output B from the differential sense amplifier SA- 2 , and another coupled to an output C from the differential sense amplifier SA- 3 . The AND gate 606 has one input terminal coupled to the output C from the differential sense amplifier SA- 3 , and another coupled to the output A from the differential sense amplifier SA- 1 . The output terminals of the AND gates 602 , 604 and 606 are coupled to the input terminals of the OR gate 608 , which generates an output based on various combinations of the A, B and C in accordance with the above Hamming distance truth table.
[0023] FIG. 7 illustrates the distributions of offset voltages for differential sense amplifiers of various sizes and configurations. Referring to FIGS. 5 and 7 simultaneously, the curve 706 shows the distribution of offset voltages for differential sense amplifiers of the same size such as SA- 1 , the curve 704 shows the distribution of offset voltages for differential sense amplifiers of the size equal to the combination of SA- 1 , SA- 2 and SA- 3 , and the curve 702 shows the distribution of offset voltages for the unit 500 that include three small differential sense amplifiers SA- 1 , SA- 2 and SA- 3 operating under the Hamming operation methodology. As shown in the drawing, the curve 706 is flatter and wider than the curve 704 , meaning that a single smaller differential sense amplifier has a higher failure probability than a single larger differential sense amplifier. Likewise, the curve 704 is flatter and wider than the curve 702 , meaning that a differential sense amplifier has a higher failure probability than an equal-sized differential sense amplifier unit having three smaller amplifiers operating under the Hamming distance methodology. The probability that three small differential sense amplifiers fail at the same time is lower than the probability that a large sense amplifier triple the size of the small amplifier fails. In other words, if the expected failure probability of a single differential sense amplifier were set to be the same as that of an amplifier unit having three smaller differential sense amplifiers, the size of the amplifier unit would have been smaller than the large amplifier.
[0024] It is noted that the number of the differential sense amplifiers can exceed three for each amplifier unit. For example, each amplifier unit can include 2*n+1 differential sense amplifiers where n is a natural number, and the logic state of the Hamming output is determined by a majority logic state among those of the outputs from the (2*n+1) differential sense amplifiers.
[0025] One advantage of the present invention is that the proposed multiple differential sense amplifiers operated under the Hamming distance methodology do not require a testing process during an initial period of running an IC. This proposed amplifier unit does not need to select a signal differential sense amplifier for operation, as all outputs from the amplifiers within the unit are considered to generate a final output that represents an input received by the unit. As a result, no additional register is needed for storing the status of the individual differential sense amplifiers.
[0026] The disclosed invention also has the advantage of improving the reliability as the possibility of a plurality of differential sense amplifiers failing at the same time is lower than that of a single differential sense amplifier having the same layout area as the combination of the three smaller ones. In other words, if the reliability of one large differential sense amplifier and that of the proposed amplifier unit are held at the same level, the layout area of the proposed amplifier unit would be smaller than the conventional differential sense amplifier.
[0027] The above illustration provides many different embodiments or embodiments for implementing different features of the invention. Specific embodiments of components and processes are described to help clarify the invention. These are, of course, merely embodiments and are not intended to limit the invention from that described in the claims.
[0028] Although the invention is illustrated and described herein as embodied in one or more specific examples, 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. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the invention, as set forth in the following claims. | A semiconductor device includes a first sense amplifier coupled to an input for generating a first output; a second sense amplifier couple to the input for generating a second output; and a third sense amplifier coupled to the input for generating a third output, wherein a fourth output amplifying the input is generated based on combinations of logic states of the first, second and third outputs. | 6 |
BACKGROUND OF THE INVENTION
This invention relates to drilling of boreholes through subterranean formations, and more particularly to directional control during substantially horizontal drilling through such formations.
The drilling of horizontal boreholes through coal seams in advance of mining for release of methane gas has recently been a subject of intense interest and activity. It is important in such drilling to be able to control the borehole trajectory so that it remains in the coal seam. In an effort to provide this control, considerable work has been done in the area of stabilizers attached to a drill rod string. One such stabilizer is described in U.S. Pat. No. 4,108,256, and a discussion of related work with stabilizers also appears in that patent.
Expandible borehole wall engaging means on a drill rod string are described in U.S. Pat. No. 3,797,589, but are intended for use in advancing the drill string rather than to provide directional control.
There has been a need for a drill rod stabilizer that can provide elevational control to a horizontal borehole being drilled, without the requirement of removing or relocating the stabilizer when a change in borehole trajectory is desired. Such a device is provided by the present invention.
SUMMARY OF THE INVENTION
According to the present invention, elevational control of a generally horizontally borehole being drilled through a subterranean formation is provided by a variable diameter drill rod stabilizer forming a part of the drill rod string. The stabilizer has an inner piston having tapered outer surfaces which cam against wall engaging segments in the stabilizer. Movement of the piston axially within a housing forming a part of the drill rod string by differential pressure of fluid flowing through a passage in the piston controls the diameter of the stabilizer.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded view of a stabilizer in accordance with the invention.
FIG. 2 is a cross section of the stabilizer shown in FIG. 1, the stabilizer being in the retracted configuration.
FIG. 2a is a cross section of the forward part of the stabilizer in the expanded position.
FIG. 3 is a cross section taken through the line 3--3 of FIG. 2.
FIG. 4 is a cross section taken through the line 4--4 in FIG. 2.
FIG. 5 is a cross section taken through the line 5--5 of FIG. 2.
FIG. 6 is an illustration of a stabilizer in accordance with the invention in place on a drill rod string, the stabilizer being in the retracted configuration.
FIG. 7 is a view of the stabilizer in place on a drill rod string, the stabilizer being in the expanded position.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The following detailed description, in conjunction with the drawings, describes the most preferred version of a variable diameter stabilizer and its operation. The operation of the stabilizer in a drilling operation will be described in the context of drilling a generally horizontal borehole through a coal seam, but it will be appreciated that the stabilizer has utility in drilling boreholes generally.
It is often desirable in degasifying a coal seam to drill a series of gas drainage holes for distances of 300 meters and more into the coal seam. Maintaining the bit on a horizontal trajectory parallel to the bedding planes of the coal bed is difficult. The natural tendency of the bit during horizontal drilling is to arc downward due to the forces of gravity. Other factors such as inclusions in the coal bed may also cause the bit to tend to deviate from the plane of the coal seam.
Prior to this invention, there were several approaches taken to maintain the bit trajectory along the desired path. The primary factors affecting the borehole trajectory are bit thrust and bit rotational speed. As a general rule, decreased thrust and increased rotational speed tend to cause a downward trajectory, while increased thrust and reduced rotational speed tend to cause an upward trajectory. It is also known that positioning a stabilizer on the drill rod near the drill bit increases the tendency of the bit to move upwardly. Using prior art procedures, it was sometimes necessary, upon encountering a downward dip in a coal bed, to remove the drill string from the hole and remove a stabilizer from adjacent the bit. This procedure is time consuming and costly, and it would be desirable to be able to eliminate the effect of the stabilizer without the necessity of removing the drill string from the hole, particulary after the hole has been drilled a substantial distance into the formation. This capability can be provided by a stabilizer which can be expanded or contracted in place by an operator.
A stabilizer in accordance with this invention preferably forms a part of a drill rod string and is positioned adjacent a drill bit as illustrated in FIGS. 6 and 7. The details of the preferred embodiment of the stabilizer itself are shown in FIGS. 1 through 5.
As best seen in FIGS. 1 and 2, stabilizer 31 comprises an outer housing 10 having an inner piston 11 mounted therein for axial sliding movement. Piston 11 includes an axial fluid flow passage through its length and terminating in outlet 13 which preferably is a hole drilled through the piston and intersecting passage 12. Piston 11 includes four enlarged shaped sections 14 including cam surfaces 15 mounted axially along piston 11. Each shaped section 14 has an associated wall engaging member 16 shown formed of two sections joined by bolts 17 and including cam follower surfaces 18. When wall engaging members 16 are assembled surrounding a shaped section 14, as best seen in FIG. 2, it will be apparent that axial movement of piston 11 from right to left in FIG. 2 will result in movement of the outer surface 19 of wall engaging member 16 from a retracted position as seen in FIG. 2 to an expanded position as seen in FIG. 2a. Simultaneously, each of the wall engaging members will be extended to the expanded position shown in FIG. 2a.
Referring again to FIGS. 1 and 2, a coil spring 20 extending from spring retainer 21 bearing against a shoulder formed in housing 10 at one end and against a rear piston surface 22 at the other end provides a bias force to piston 11 tending to maintain the stabilizer in the retracted configuration shown in FIG. 2. The extent of the bias force can be controlled by spring strength and by adjustable spring compression setting means comprising an outer sleeve 23 extending rearwardly from rear piston surface 22. Sleeve 23 is threaded onto piston 11 to a desired position and maintained in position by locking pin 24.
Forward travel of piston 11 in housing 10 is limited by front stop member 25 which is bolted to housing 10 as seen in FIG. 2. Front piston member 26 is welded or otherwise attached to piston 11, and upon contact with front stop member 25, forward movement of piston 11 is stopped. Rearward movement of piston 11 is limited by contact of stop bolt 27 against stop member 25. Stop bolt 27 is threaded into the end of piston 11 as best seen in FIG. 1.
Fluid passage 12 through piston 11 begins at the right hand end of the device as viewed in FIG. 2 and extends axially therethrough to fluid outlet 13. The forward end of passage 12 is blocked by stop bolt 27 such that all fluid flowing through passage 12 exits through outlet 13.
Front stop member 25, as best seen in FIGS. 1 and 3, includes recessed notches 28 which allow fluid flow from fluid outlet 13 through notches 28 and on through the housing 10 and the remaining drill rod string and drill bit. This flow pattern occurs when the piston is in the position shown in FIG. 2.
When it is desired to change the stabilizer to the expanded configuration, fluid pressure upstream from the stabilizer is increased, resulting in an increased pressure drop from fluid flow through passage 12 which in turn overcomes the bias effect of spring 20 enabling piston 11 to move from the position shown in FIG. 2 to the position shown in FIG. 2a. In order to assure a positive stroke of piston 11, it will be seen that as fluid outlet 13 initially moves, it enters front stop member 25 thereby momentarily stopping flow of fluid through passage 12 and causing a large increase in the force acting on rear piston surface 22 whereby piston 11 is swiftly and positively moved to the position shown in FIG. 2a with fluid outlet 13 extending beyond front stop member 25 such that fluid flow through the stabilizer is resumed.
The force needed to actuate the stabilizer from a retracted to an expanded configuration is a function of several design variables including the strength and compression on spring 20, the size of fluid passage 12 and the angle of the cam surfaces which move the wall engaging members. Additionally, as best seen in FIG. 1, a reduced diameter orifice 29 can be placed in flow passage 12 and retained therein by orifice retainer 30 threaded into piston 11.
The operation of the stabilizer in accordance with the invention will now be described with particular reference to FIGS. 6 and 7. A stabilizer 31 is attached to a drill rod string 32 having a drill bit 33 at its forward end. As drilling progresses through borehole 34, the pressure of fluid flowing through drill rod string 32 is maintained at a pressure low enough to enable stabilizer 31 to remain in the retracted configuration as shown in FIG. 6. In this configuration, the drill behaves as if there were no stabilizer, and the natural tendency of the drill under these conditions is to develop a slight downward angle in borehole trajectory. After a period of time, determined by operator experience and/or borehole position measurements obtained by known techniques and apparatus, it is desired to develop a slight upward angle in borehole trajectory. This can be accomplished utilizing the stabilizer of this invention by increasing the pressure of the fluid flowing through the drill rod string to the point where it overcomes the bias effect of spring 20 and enables the piston 11 to move forward, changing the stabilizer 31 from the retracted configuration shown in FIGS. 2 and 6 to the expanded configuration shown in FIGS. 2a and 7. In the expanded configuration, which is shown somewhat exaggerated in FIG. 7, the wall engaging members 16 extend to provide an effective diameter approximating that of the borehole 34. This has the same effect as having a fixed stabilizer near the drill bit. However, it avoids the necessity of removing the entire drill rod string and inserting a fixed stabilizer to provide the upward trajectory to the borehole.
Thus, utilizing the stabilizer of this invention, an operator can control the trajectory of a borehole by alternately drilling with the stabilizer in the retracted and expanded configurations.
It will be appreciated that numerous variations from and modifications to the device as illustrated and described could be made without departing from the invention. For example, the device as described includes a wall engaging member at each 90° arc about the circumference of the stabilizer. More or fewer wall engaging members appropriately distributed could be utilized. | A variable diameter drill rod stabilizer including an inner piston having cam surfaces which bear against wall engaging segments. Movement of the piston axially within a drill rod section by differential pressure of a fluid flowing through a passage in the piston moves the wall engaging segments radially and controls the diameter of the stabilizer. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is directed to highway finishing machines and, more particularly, to a double tamping bar vibratory screed for laying a roadway which is capable of being affixed to a conventional piece of lay-down equipment and can run at higher speeds while providing an extremely high compaction density, especially with high density materials.
2. Description of the Related Art
Highway finishing machines are well known in the art and generally consist of a lay-down machine which accepts the material that is to form the roadbed, distributes it across the desired width of roadway to be laid and compacts the material, usually with a vibrating plate, to a desired compaction rate and finish. These machines have been found to be effective for laying some materials, such as asphalt, as well as some types of conventional concrete.
Recently, highway construction companies have found it very desirable to lay road mixes having higher densities in order to reduce wear on the roadways and thereby increase their life and to accommodate traffic of heavy vehicles and equipment. These higher densities are normally provided in concrete applications by increasing the level of aggregate within the concrete mix itself. One form of high density concrete is known as roller-compacted concrete which is known as a zero-slump concrete mixture and which has been basically used for low-volume, low speed roadways having vehicle traffic with high axial loads.
Due to its increased density, roller-compacted concrete has been very difficult to lay with conventional road paving machinery. This is due to its lack of plasticity which prevents it from flowing into a smooth even surface and inhibits proper compacting. A smooth finish is necessary for roadways, especially where a higher vehicle speed is desired, in order to prevent excess tire wear and reduce noise. Proper compacting is necessary in order to prevent breakdown of the roadway, especially when heavy equipment and vehicles are used.
Roadway laying machines have been developed for laying this type of high density or roller-compacted concrete. One type of such a machine is disclosed in U.S. Pat. No. 4,507,014 issued to Heims et al which discloses a highway finishing machine having at least two stamps which have a common eccentric support. These two stamps cooperatively slidingly engage with one another and have different vertical lengths so that they reciprocate at two slightly different levels.
Major disadvantages with existing highway paving machines, especially when used for laying high density materials such as roller-compacted concrete, are their relatively slow linear speeds, their inability to adapt to different materials and consistencies and their tendency to break up or tear the material being applied. Therefore, the process becomes very time consuming and creates the need for further compacting and surface treatment after the initial layer is applied.
SUMMARY OF THE PRESENT INVENTION
The present invention provides a method and apparatus for laying a variety of materials to form a road surface or, alternatively, a base material for a road surface which can be adjusted to include asphalt and conventional concrete as well as roller-compacted concrete. Additionally, the apparatus of the present invention is capable of operating at much higher speeds while providing a very smooth, even surface and an extremely high compaction rate.
The present invention is embodied in a highway finishing machine having a main body portion which is detachably mounted to a conventional concrete or asphalt lay-down machine. The front end of the main body portion is positioned adjacent the rear end of the lay-down machine and has a strike-off plate on its leading edge which strikes off the material provided by the lay-down machine at a predetermined vertical height in preparation for compacting. Located a predetermined distance behind the strike-off plate are two tamping bars having independent eccentric shafts which are positioned parallel to one another and span the width of the machine. Furthermore, these tamping bars are resiliently attached to the eccentric shafts to help deter complete breakdown or over-compaction of the material.
These tamping bars are particularly significant since they are designed with a slightly rearward angle of attack and have horizontal material engagement faces which contact the material to be compacted. This design forces the material straight down and toward the rear of the device instead of toward the strike-off plate which allows a wider variety of applications without tearing the surface of the material.
Located immediately behind the tamping bars is a vibrating plate which aids compaction and improves the surface texture when laying particular types of material.
The advantages of such a device are its compact form, its ability to adapt to a wide range of existing lay-down equipment, its ability to operate at higher speeds and its ability to handle a wide variety of materials including very dense materials such as roller-compacted concrete.
BRIEF DESCRIPTION OF THE DRAWINGS
Further features and advantages of the present invention are set forth with particularity in the appended claims. The invention may best be understood by making reference to the following description, taken in conjunction with the accompanying drawings and several figures of which like reference numerals identify identical elements and wherein:
FIG. 1 is a side elevational view of a conventional roadway lay-down machine which includes the screed device of the present invention;
FIG. 2 is a top, fragmentary plan view of the screed device of the present invention with its top cover removed;
FIG. 3 is a lateral cross-sectional view taken along lines III--III of FIG. 2 with the top cover in place;
FIG. 4 is a longitudinal, fragmentary sectional view taken along lines IV--IV of FIG. 2 with the top cover in place;
FIG. 5 is a fragmentary longitudinal view taken along lines V--V of FIG. 2;
FIG. 6 is a fragmentary top plan view of the screed device, similar to FIG. 2;
FIG. 7 is a fragmentary lateral view taken along lines VII--VII of FIG. 2; and
FIG. 8 is a fragmentary lateral view taken along lines VIII--VIII of FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The principles of the present invention are incorporated in a tamping bar vibratory screed generally indicated by numeral 10 in the drawings. The screed 10 is shown in FIG. 1 in conjunction with a conventional piece of lay-down equipment 12 which is fed material to be compacted by a dumptruck 13.
As described above, existing highway finishing machines usually rely on a vibrating plate alone to provide the necessary compaction rates and finishes. While this practice is acceptable for materials which are relatively flowable, it is not suitable for less flowable, denser materials.
It is to be noted that the width of the screed 10 is adjustable to the desired width of roadway which is to be laid. This adjustability is provided by having a screed 10 which is made up of sections which are added on to provide a variety of screed widths. In the exemplary embodiment, the screed 10 is constructed of a basic screed section of 8 ft. which can be increased up to 24 ft. by adding 4, 2 and 1 foot sections. The 8 ft. section itself is made up of 2 four foot sections which are affixed with a pivot point which permits either a positive or negative crown adjustment on the roadway, depending upon the desired application. Although each four foot screed section is designed as an independent unit in the exemplary embodiment, the smaller sections may be independent units or may be dependent upon the larger four foot unit to which it is attached for power as will be described in further detail hereinafter.
FIGS. 2 and 3 generally illustrate an eight foot screed 10 having two, four foot sections 10a and 10b which is shown fragmented. For clarity and ease of description, the screed 10 will be described as having only one section, it being understood that although some elements of the screed sections 10a and 10b are in different positions, they are basically identical and interchangeable.
The screed 10 may be powered electrically or pneumatically by its own power source or by the lay-down machine 12 and may be designed with its own means of propulsion. In the exemplary embodiment the screed 10 is provided with power and propulsion from the lay-down machine 12.
As FIG. 3 illustrates, the screed 10 is basically composed of a housing 14, a front plate 16, a front tamper bar 18, a rear tamper bar 20 and a vibrating plate 22. Normally, the screed 10 is suspended from the lay-down machine 12 by arms 24 positioned at the top of the housing 14 near its longitudinal ends, which are connected to the lay-down machine 12 with a plurality of bolts 25 in the exemplary embodiment, but can be connected in a variety of ways. These bolts 25 can be positioned in different ways and in different locations to provide a height or width adjustment between the screed 10, the roadbed and the lay-down machine 12.
As FIGS. 2 and 3 illustrate, the housing 14 is generally rectangular in shape and serves as a mounting structure for the interior parts as well as a protective shell or cover. The housing 14 is composed of a top cover having at least one door 26 and a network of transverse support members 28 which are integrally affixed to longitudinal support members 29, such as by welding, for example. Although the number of support members 28 and 29 may vary, two longitudinal support members 29 and three lateral support members 28 are employed per screed section 10a in the exemplary embodiment. The doors 26 is hinged to the remainder of the housing 14 on one longitudinal support member 29 by at least one hinge 27 and provides a protective cover against the elements as well as a safety cover to prevent accidental injuries or to prevent items from falling into the housing 14 and is easily openable to provide access to the interior of the screed 10. The support members 28 and 29 provide an interior frame for stability of the screed 10 as well as a frame from which the components of the present invention will be suspended as will be described in greater detail hereinafter.
As shown in FIG. 3, the arms 24 are affixed at either end of the screed 10 to the longitudinal support members 29 by supports 29a and 29b at the front and rear of the screed 10 respectively. These supports 29a and 29b are bolted to the longitudinal support members 29, and 29b may be in the form of an adjustable shock absorber to provide resiliency and height adjustability to the screed 10.
The screed 10 travels in a left to right direction with respect to FIG. 3 and first contacts the material to be compacted 30 with the front plate 16. The material to be compacted 30, is normally fed to the front plate 16 by an auger 31 which can be part of the screed 10 or the lay-down machine 12. The front plate 16 is affixed to the housing 14 by member 33. Member 33 may be a rigid member or may be a spring member or a type of shock absorber which will provide limited resilience to the front plate 16 which, in operation, serves to strike off the material to be compacted at a predetermined, uniform height just prior to compaction. In the exemplary embodiment, the front plate 16 is flat and slanted with a rearward angle as viewed from the front of the screed 10 which serves to slice off a vertical height of the material to be compacted. This angle also directs the excess material away from the front plate 16 and under the screed 10. Alternatively, the front plate 16 may be formed as a curved member or any other desired shape and may be affixed in a variety of ways so long as the necessary material height is achieved.
Directly behind and spaced a predetermined distance from the front plate 16 are the front and rear tamper bars 18 and 20. As FIG. 4 shows, both of the tamper bars 18 and 20 span the entire width of the screed 10 and have a relatively short height in comparison to their width. These tamper bars 18 and 20 are of approximately equal length, are positioned one behind the other, are slighlly spaced apart and do not contact each other in operation. As FIGS. 3, 7 and 8 illustrate, a slight gap 32 is established between the rear of front plate 16 and the front tamper bar 18 having a width of approximately 1/2" (12.8 mm) in the exemplary embodiment. The gap 32 accommodates any excess material 34 (shown in FIG. 7) which may be struck off by the front tamper bar 18, after the initial striking off by front plate 16 before the tamper bar 18. With this design, by allowing for accummulation of excess material 34 in the gap 32, a smooth, even finish is provided by not forcing excess material under the tampers 18 and 20.
In the exemplary embodiment, the front tamper bar 18 extends approximately 1 inch (25.6 mm) below the bottom edge of the front plate 16 when the front tamper bar 18 is at the top of its stroke. Similarly, rear tamper bar 20, at the top of its stroke, extends approximately 1/4 of an inch (6.4 mm) below the front tamper bar 18 and the vibration plate 22 extends approximately 1/8 to 1/4 of an inch (3.2 mm to 6.4 mm) below the rear tamper bar 20. With this design, a gradual breakdown and compaction of the material 30 is achieved which accounts for the superiority in speed and performance of the screed 10 of the present invention. Additionally, the vertical stroke of each tamper bar 18 and 20 ranges between 11/2"-2" (38.5 mm-51.3 mm) in the exemplary embodiment and can be adjusted longer or shorter to suit existing conditions as will be explained in further detail hereinafter. It is to be noted that the dimensions stated above may vary without departing from the teachings of the present invention.
Each of the tampers 18 and 20 has a flat, horizontal contact surface 36, and is powered by at least two drive assemblies made up of a shaft 38 and a spring connection 40 which in turn are connected to a pivot arm 42 for the tamper 18 and a pivot arm 44 for the tamper 20. Each tamper 18 and 20 can include supports pads 18b and 20b to secure the tampers 18 and 20 to their respective shafts 38. FIG. 8 illustrates a drive assembly of tamper bar 18 which is isolated for clarity. FIG. 4 shows that each of the tamper bars 18 and 20 has two drive assemblies along its length which are found to be adequate for driving the tamper bars 18 and 20 in the exemplary embodiment. Alternatively, the number of drive assemblies per tamper bar 18 and 20 may vary.
As FIG. 3 illustrates, the flat contact surfaces 36 are arranged at a slight angle with respect to the longitudinal axis of the tamper shafts 38 which in turn are affixed with a slight rearward angle with respect to the vertical plane. The angle of the contact surfaces 36 has the effect of providing a flat, horizontal surface while the slight rearward angle of the shafts 38 enables the material 30 to be pushed toward the rear of the screed 10 during tamping. The combination of these two design features enables the screed 10 to run at much higher speeds while providing a smooth, horizontal surface without any tearing and having the necessary compaction rates required, even for highly dense materials.
Additionally, as shown in FIG. 7 each of the tamper bars 18 and 20 is independently driven by eccentric cam drive members 46 and 48 which are coupled to the respective pivot arms 42 and 44 by drive shafts 50 and 52 respectively. In the context of the present application, independently driven refers to the fact that each of the tamper bars 18 and 20 is driven by separate eccentrics 46 and 48 respectively which are rotated by separate shafts to provide the desired motion. The rotation of each shaft and eccentric may be independent or in tandem.
Due to the independent eccentric drive members 46 and 48, the tamper bars 18 and 20 can be arranged to operate at the same speeds, different speeds, different strokes or at different intervals to provide a wide variety of compacting. In the exemplary embodiment, these eccentric drive members 46 and 48 are driven by the same motor 54 but can have separate motors as shown in FIG. 6 as 54 and 54a, if desired. In either case, the versatility in speed and stroke as well as the independence of each of the tamper bars 18 and 20 is maintained.
FIGS. 2, 3, 5, 7 and 8 illustrate the drive system of the exemplary embodiment of the present invention. It is to be understood that a variety of drive systems may be employed so long as the independence of the tamper bars 18 and 20 is maintained without departing from the teachings of the present invention.
In the exemplary embodiment as illustrated in FIGS. 2 and 3, the motor 54 is affixed to one of the lateral supports 28, such as, for example, by bolts 56. The output of the motor 54 is in turn connected to a chain belt 58 which directly drives a shaft 60. The shaft 60 is in turn connected at either end to eccentric drive members 48 and is suspended from lateral supports 28 by collars 62. With this arrangement, the eccentric motion of rear tamper bar 20 is provided. More specifically, the motor 54 rotates shaft 60 which turns eccentric drive members 48 thereby providing a vertical stroke to the shaft 52 of the pivot arm 44 which pivots about a pivot point 44a and provides the desired movement of the rear tamper bar 20.
At the same time as illustrated in FIGS. 2 and 3, one end of the shaft 60 is connected to a timing chain 64 by a sprocket 60a which drives a shaft 66 through a sprocket 66a. This type of drive system exists on both ends of the screed 10, one drive for screed section 10a and one drive for screed section 10b. As FIG. 2 shows, the shaft 66 is similarly suspended from lateral supports 28 by collars 62 and is connected to eccentric drive members 46 which provide a vertical stroke to the shaft 50 of the pivot arm 42 which in turn pivots about a pivot point 42a and provides the desired movement of the front tamper bar 18.
According to this exemplary embodiment, one motor 54 powers a single four foot screed section and drives two shafts 60 and 66 which in turn provide the desired stroke to both front and rear tamper bars 18 and 20 associated with the four foot screed section. As mentioned previously, it is to be understood that each shaft 60 and 66 may be driven by its own motor or by any other driving means without departing from the teachings of the present invention, so long as the tamper bars 18 and 20 are separately driven to provide the desired versatility.
The stroke and timing of each of the tamper bars 18 and 20 may be adjusted in several ways. To initially change the timing, the timing chain 64 may be adjusted or replaced. Alternatively, the eccentric drive members 46 and 48 may be changed to achieve different strokes, speeds and stroke lengths. Finally, the tension in springs 40 may be adjusted to vary the compaction or force of the stroke of each of the tamper bars 18 and 20.
It is also to be noted that due to the springs 40, overcompaction as well as under-compaction of the material 30 is eliminated. More specifically, adjustments are frequently made to the screed 10 while it is laying a particular roadway. These adjustments are necessary due to the variations which may occur in the material 30 from the particular truck load which is being fed into the screed 10 as well as other factors. These variations include the particular mix of concrete and aggregate, the particular size of aggregate, the inclusion in the aggregate of a larger piece of material as well as the outside temperature and weather conditions and the surface upon which the material 30 is being laid. Accordingly, since these springs 40 can be easily adjusted at the job site with a minimum amount of effort, the tamper bars 18 and 20 may be fine tuned to a particular job. Also, due to the resiliency provided by the springs 40 to the tamper arms 18 and 20, a large piece of aggregate within the material 30 may be traversed without damaging the screed 10 or providing an uneven finished surface.
The screed sections 10a and 10b, as well as any additional screed sections can be affixed to one another in a variety of ways. In the exemplary embodiment, the sections 10a and 10b are basically bolted together (not shown), and, as illustrated in FIGS. 2 and 4, tamper bars 18 and 20 of adjacent sections are joined by a bolt 18a or 20a respectively and maintain even tamping along their lengths. The bolting of sections 10a and 10b is normally accomplished with a center pivot using a turnbuckle arrangement in a conventional manner.
Immediately following the rear tamper bar 20 is a wall 21 and a vibrating plate 22. The vibrating plate 22 vibrates in a vertical direction as it travels along over the material which has been pre-compacted by the tamper bars 18 and 20 to provide a smooth even finish. The vibrating plate 22 is driven by a separate motor 68. The wall 21 is a thin sheet of metal or other material which shields the interior of the screed 10 from any outside materials and may be connected to adjoining sections of walls 21 by a bolt 21a, for example.
To keep the compacted material from expanding horizontally and to provide a discrete outside edge, edging shoes 70 are employed along the sides of the screed 10 as FIGS. 3 and 4 illustrate. These edging shoes 70 extend parallel to the direction of travel of the screed 10, make up the exterior side walls of the housing 14 and can be vertically adjusted to provide different material thicknesses. As a consequence, no outside forms are needed.
The operation of the screed 10 will now be explained in greater detail. Material to be compacted normally arrives at the application site in a dumptruck 13 which feeds the front end of the conventional lay-down machine 12. The lay-down machine 12 is basically composed of an auger 31 which distributes the material across the desired width. In some instances, the lay-down machine 12 may be equipped for providing an initial rough compaction of the material such as with a vibrating plate. Alternatively, the material may proceed directly from the auger into the screed 10. In either event, the material exits the rear of the lay-down machine 12 where the screed 10 is then driven or pulled across. At this point, the strike-off plate 16 strikes off the material to a uniform height in preparation for compaction. After passing under the front plate 16, the material is then compacted in succession by front tamper bar 18 and rear tamper bar 20 which provide an initial compaction. Next, the vibrating plate 22 passes over the material to provide a smooth surface which may be compacted even further by a roller (not shown) if desired. During this entire sequence, the edging shoes 70 maintain the necessary discrete edge to the roadway.
As is apparent from the foregoing specification, the invention is susceptible of being embodied with various alterations and modifications which may differ particularly from those that have been described in the preceding specification and description. It should be understood that I wish to embody within the scope of the patent warranted hereon all such modifications as reasonably and properly come within the scope of my contribution to the art. | A double tamping bar vibratory screed is disclosed for use with a lay-down machine for laying a roadway. The screed consists of a main body portion having a strike-off plate on its leading edge which is followed by two tamping bars having independent eccentric shafts. These tamping bars are in turn followed by a vibrating plate which together perform the necessary compaction and provide a smooth, even surface with a variety of materials.
The tamping bars are resiliently designed with a slightly rearward angle of attack and have horizontal material engagement faces which contact the material to be compacted and provide the desired result. | 4 |
CROSS-REFERENCE TO RELATED APPLICATION
This present application claims priority to TAIWAN Patent Applications: Serial No. 100141633 filed on Nov. 15, 2011, Serial No. 101116071 filed on May 4, 2012, Serial No. 100141653 filed on Nov. 15, 2012, and Serial No. 101121694 filed on Jun. 15, 2011, which are all herein incorporated by reference.
TECHNICAL FIELD
The present invention generally relates to anti-UV fiber and the method of manufacturing thereof.
DESCRIPTION OF THE RELATED ART
The current anti-UV cloth uses a material to coat on a cloth. The process requires an additional coating process and the coated material is likely to be removed from the cloth, thereby causing the anti-UV function failure.
SUMMARY
The present invention provides a method of forming color change lens, comprising preparing molding base material and preparing color changeable material; mixing said molding base material and said color changeable material with a weight percentage ratio; loading said mixed molding base material and said color changeable material into a molding apparatus; forming lens by molding process by said molding apparatus with a temperature, wherein said lens is color changeable when sunlight irradiates on said lens.
If the color changeable material includes photochromic or thermal-chromic dye, the molding process includes injection molding, extrusion molding and the molding temperature is below dissociation temperature of said photochromic or thermal-chromic dye, a molding temperature is about 180-200 200-220 220-230 230-250° C., and said molding base material is PC or PMMA.
If the color changeable material includes silver halide and copper oxide, the silver halide includes silver bromide, silver chloride or the combination. The molding process includes injection molding or extrusion molding. The molding temperature is about 180-200 200-220 220-230 230-250, 250-280, 280-300° C. The molding base material is PC or PMMA. If the color changeable material includes titanium dioxide doped with silver, the molding process includes injection molding or extrusion molding. The molding temperature is about 180-200 200-220 220-230 230-250, 250-280, 280-300° C.
A method of forming color change fiber, comprises preparing polymer base material and preparing color changeable material; mixing said polymer base material and said color changeable material with a weight percentage ratio; loading said mixed said polymer base material and said color changeable material into a melting apparatus; forming polymer fiber by spinning, weaving process, wherein said polymer fiber is color changeable when sunlight irradiates on said polymer fiber. The color changeable material includes photochromic or thermal-chromic dye wherein a melting temperature is below dissociation temperature of said photochromic or thermal-chromic dye. The melting temperature is about 180-200 200-220 220-230 230-250° C., 250-300° C.
The color changeable material includes silver halide and copper oxide, wherein said silver halide includes silver bromide, silver chloride or the combination. The melting temperature is about 180-200 200-220 220-230 230-250, 250-280, 280-300° C. The color changeable material includes titanium dioxide doped with silver, wherein a molding temperature is about 180-200 200-220 220-230 230-250, 250-280, 280-300° C.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the diagram of the present invention.
FIG. 2 shows the diagram of the present invention.
DETAILED DESCRIPTION
Some sample embodiments of the invention will now be described in greater detail. Nevertheless, it should be recognized that the present invention can be practiced in a wide range of other embodiments besides those explicitly described, and the scope of the present invention is expressly not limited expect as specified in the accompanying claims. The following embodiment is just to illustrate rather than limiting the present invention.
FIG. 1 shows the process of the present invention, the first step 100 is to prepare the fiber material and photochromic (or thermal-chromic) dye. The fiber is plastic fiber.
The photochromic (or thermal-chromic) dye is sensitive to the ultra-ray, when the photochromic dye is irradiated by the sunlight, the material will change it color due to the chemical structure is change. Therefore, the present invention will add the photochromic or thermal-chromic dye during the melting process to melt the polymer which is used to form the polymer fiber, and optionally, the stabilizers, UV absorbers or antioxidants may be added during the melting process. The photochromic dye may be spiropyrans spiroxazines fulgide fulgimides benzopyran naphthopyran spirobenzopyran Spironaphthopyran spirobenzoxazine or spironaphthoxazine.
The weight percentage of the photochromic dye is about 0.01%˜0.3%. The process temperature during the melting is preferably under 260° C. to prevent the chemical structure of the photochromic dye from being dissociation. If the system uses the PMMA as the base material, the temperature of the injection is below 230° C., preferably, 180-200° C. If PC is the base material, the temperature of the injection is below 250° C., preferably, 220-245° C. Other material could be used, such as PET, Polyamide Fiber, Nylon 6, Nylon 6.6, Nylon1, Polyester Fiber, PBT, PTT, Polyacrylonitrile Fiber, Acrylic Fiber, Polyethylene Fiber, Polypropylene Fiber (PP), Polyvinylalcohol Fiber (PVA), Polyvinylchloride Fiber (PVC), Polytetrafluoroethylene Fiber (PTFE), Polyurethane Fiber, (PU), HMPE, PPS.
Please refer to FIG. 1 , the polymer fiber material (base material) is mixed with the photochromic dye, and the temperature is raised to melting the polymer fiber material, and the photochromic dye is distributed evenly within the melted polymer, step 110 . The next step is drawnwork procedure to form the yarn with the dye thereof, step 120 . The next step is to perform the spinning, weaving process to allow the yarn to be the fiber, step 130 . The fiber may be used to manufacture cloths, hat, sock, glove, pan, skirt, umbrella, which includes the photochromic dye to absorb the UV radiation and change the color to allow the user “see” the anti-UV effect. The temperature of the melting may be 180-200 200-220 220-230 230-250° C., 250-300° C. depending on the chosen polymer and the dyne. The base material should be dried with 1-5 hours depending on the quantity. Then, the dried based material is mixed with the photochromic dye by certain ratio. The ratio and the process temperature will affect the result of the color change. Further, the uppermost of the melting process temperature should be lower than the dissociation temperature of the dye. Further, the silver halide may be used alone or mixed with the photochromic dye to achieve the color change effect, in the embodiment, copper oxide maybe added during the process temperature is 220-250, 250-280° C. In another embodiment, titanium dioxide with silver may be used with the PMMA or PC to form the color change lens by the above injection or extrusion molding. The weight percentage is almost the same with the dye. The size of the particles may be 200-1000 nanometers. Nano-sized Ag deposits were formed on two commercial TiO 2 nanopowders. Under the sunlight the titanium dioxide with doped silver may change color due to the silver may catch or loss the electrons. The titanium dioxide with doped silver may be used to eliminate the bacteria on the lens, simultaneously. Preferably, the titanium dioxide may be formed on the lens surface by immersion on the solution of titanium dioxide with doped silver. Nano-sized Ag deposits were formed on two commercial TiO 2 nanopowders using a photochemical reduction method. The inactivation kinetics of nAg/TiO 2 was compared to the base TiO 2 material and silver ions leached from the catalyst. The increased production of hydroxyl free radicals is responsible for the enhanced viral inactivation. The doped silver TiO 2 material may have the color change effect as well.
The method can be introduced into the manufacture of contact lens, please refer to FIG. 2 . Please refer to FIG. 2 , the polymer material (base material) is mixed with the photochromic dye 200 , and the temperature is raised to melting the polymer material, and the photochromic dye is distributed evenly within the melted polymer, step 210 . The next step is to perform the molding procedure to form the plastic contact lens by well-known procedure, step 220 . The next step is to perform the stripping procedure to remove the molding devices to allow the lens be have the dyne contained therein, step 230 . The contact lens includes the photochromic dye to absorb the UV radiation and change the color to allow the user “see” the anti-UV and fashion effect. The temperature of the melting may be 180-200 200-220 220-230 230-250° C., 250-300° C. depending on the chosen polymer and the dyne. The base material should be dried with 1-5 hours depending on the quantity. Then, the dried based material is mixed with the photochromic dye by certain ratio. The ratio and the process temperature will affect the result of the color change. Further, the uppermost of the molding process temperature should be lower than the dissociation temperature of the dye. Further, the silver halide may be used alone or mixed with the photochromic dye to achieve the color change effect, in the embodiment, copper oxide maybe added during the process temperature is 220-250, 250-280° C. In another embodiment, titanium dioxide with silver may be used with the PMMA or PC to form the color change lens by the above injection or extrusion molding. The weight percentage is almost the same with the dye. The size of the particles may be 200-1000 nanometers. Nano-sized Ag deposits were formed on two commercial TiO 2 nanopowders. Under the sunlight the titanium dioxide with doped silver may change color due to the silver may catch or loss the electrons. The titanium dioxide with doped silver may be used to eliminate the bacteria on the lens, simultaneously. Preferably, the titanium dioxide may be formed on the lens surface by immersion on the solution of titanium dioxide with doped silver. Nano-sized Ag deposits were formed on two commercial TiO 2 nanopowders using a photochemical reduction method. The inactivation kinetics of nAg/TiO 2 was compared to the base TiO 2 material and silver ions leached from the catalyst. The increased production of hydroxyl free radicals is responsible for the enhanced viral inactivation.
The IR causes the cornea, lens and vitreous humor damage, for example 0.8˜1.2 micron-meter IR ray and 760˜1400 nm IR ray is not good the eyes. The method can be introduced into the manufacture of contact lens with IR cut function if the anti-IR material is introduced into above embodiments alone or combination. The polymer material (base material) is mixed with the anti-IR material with size of about 80-350 nano-meter. The other procedure is similar with the above embodiments.
Aforementioned description is to illustrate purposes of the present invention, technical characteristics to achieve the purposes, and the advantages brought from the technical characteristics, and so on. And the present invention can be further understood by the following description of the preferred embodiment accompanying with the claim. | A method of forming color change fiber, comprises preparing polymer base material and preparing color changeable material; mixing said polymer base material and said color changeable material with a weight percentage ratio; loading said mixed said polymer base material and said color changeable material into a melting apparatus; forming polymer fiber by spinning, weaving process, wherein said polymer fiber is color changeable when sunlight irradiates on said polymer fiber. | 3 |
This is a division of application Ser. No. 479,429, filed Mar. 28, 1983 now U.S. Pat. No. 4,533,661.
BACKGROUND OF THE INVENTION
Greenlee et al. in European Patent Application No. 58,427 disclose that phosphonamide derivatives of proline, pipecolic acid, and thiazolidinecarboxylic acid possess angiotensin converting enzyme inhibition activity.
Harris et al. in European Patent Application No. 46,289 disclose that various substituted enantholactam derivatives possess angiotensin converting enzyme inhibition activity.
Harris et al. in European Patent Application No. 46,291 disclose that various substituted caprolactam derivatives possess angiotensin converting enzyme inhibition activity.
Harris et al. in European Patent Application No. 46,292 disclose that various substituted caprylolactam derivatives possess angiotensin converting enzyme inhibition activity.
SUMMARY OF THE INVENTION
This invention is directed to the lactam compounds of formula I and salts thereof ##STR2## n is an integer from 1 to 4. R 1 is hydrogen, lower alkyl, amino substituted lower alkyl, hydroxy substituted lower alkyl, or halo substituted lower alkyl.
R 3 is hydrogen, lower alkyl, ##STR3## m is zero or an integer from 1 to 4. R 14 is hydrogen, lower alkyl of 1 to 4 carbons, lower alkoxy of 1 to 4 carbons, lower alkylthio of 1 to 4 carbons, halo, trifluoromethyl, or hydroxy.
p is an integer from 1 to 3 provided that p is more than one only if R 14 is hydrogen, methyl, methoxy, chloro, or fluoro.
R 4 is alkyl of 1 to 10 carbons, ##STR4## s is zero or an integer from 1 to 7. t is an integer from 1 to 8.
R 6 and R 7 are independently selected from lower alkyl, halo substituted lower alkyl, ##STR5## R 5 and R 2 are independently selected from hydrogen, lower alkyl, benzyl, benzhydryl, salt forming ion, or ##STR6## R 10 is hydrogen, lower alkyl, cycloalkyl, or phenyl. R 11 is hydrogen, lower alkyl, lower alkoxy, cycloalkyl, phenyl, benzyl, or phenethyl.
DETAILED DESCRIPTION OF THE INVENTION
This invention in its broadest aspects relates to the lactam compounds of formula I above, to compositions containing such compounds and to the method of using such compounds as anti-hypertensive agents.
The term alkyl used in defining R 4 refers to straight or branched chain hydrocarbon radicals having up to ten carbons, for example, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, t-butyl, pentyl, isopentyl, heptyl, octyl, decyl, etc. The term lower alkyl used in defining various symbols refers to straight or branched chain radicals having up to seven carbons. The preferred lower alkyl groups are up to four carbons with methyl and ethyl most preferred. Similarly, the terms lower alkoxy and lower alkylthio refer to such lower alkyl groups attached to an oxygen or sulfur.
The term cycloalkyl refers to saturated rings of 3 to 7 carbon atoms with cyclopentyl and cyclohexyl being most preferred.
The term halogen refers to chloro, bromo, and fluoro.
The term halo substituted lower alkyl refers to such lower alkyl groups described above in which one or more hydrogens have been replaced by chloro, bromo, or fluoro groups such as trifluoromethyl, which is preferred, pentafluoroethyl, 2,2,2-trichloroethyl, chloromethyl, bromomethyl, etc. Similarly, the terms amino substituted lower alkyl and hydroxy substituted lower alkyl refer to such lower alkyl groups described above in which one or more hydrogens have been replaced by --NH 2 or --OH, i.e., aminomethyl, 2-aminoethyl, 3-hydroxypropyl, etc.
The symbols ##STR7## represent that the alkylene bridge is attached to an available carbon atom.
The compounds of formula I wherein R 4 is alkyl, ##STR8## are prepared by coupling a phosphonochloridate of formula II wherein R 5 is lower alkyl, benzyl or benzhydryl ##STR9## with the lactam ester of the formula ##STR10## Preferably, the lactam ester of formula III is in its hydrochloride salt form and R 2 is lower alkyl, benzyl, or benzhydryl.
The products of formula I wherein either or both of R 5 and R 2 are lower alkyl, benzyl, or benzhydryl can be hydrogenated, for example, by treating with hydrogen in the presence of a palladium on carbon catalyst or chemically treated such as with sodium hydroxide in aqueous dioxane or with trimethylsilylbromide in dichloromethane to yield the products of formula I wherein R 5 and R 2 are hydrogen.
The ester products of formula I wherein R 2 is ##STR11## may be obtained by employing the lactam of formula III in the above reaction with the ester group already in place.
The ester products of formula I wherein R 2 is ##STR12## can also be obtained by treating the product of formula I wherein R 2 is hydrogen with a molar equivalent of the compound of the formula ##STR13## wherein L is a leaving group such as chlorine, bromine, tolylsulfonyloxy, etc. The diester products wherein R 5 and R 2 are the same and are ##STR14## can be obtained by treating the product of formula I wherein R 5 and R 2 are both hydrogen or an alkali metal salt with two or more equivalents of the compound of formula IV.
The ester products of formula I wherein R 5 is ##STR15## can be obtained by treating the product of formula I wherein R 5 is hydrogen or an alkali metal salt and R 2 is benzyl or benzhydryl with the compound of formula IV in the presence of base. Removal of the R 2 ester group such as by hydrogenation yields the products of formula I wherein R 5 is ##STR16## and R 2 is hydrogen.
The phosphonochloridates of formula II are described in the literature and in particular by Kosolapoff et al. in Organic Phosphorous Compounds, Vol. 7, Chapter 18 (Wiley, 1972).
The compounds of formula I wherein R 4 is --(CH 2 ) t --NH 2 are prepared by reacting a phthalidyl protected compound of the formula ##STR17## wherein R 5 is lower alkyl, benzyl or benzhydryl with the lactam ester of formula III, preferably wherein R 2 is benzyl, in the presence of triethylamine to yield the protected compound of the formula ##STR18## Treatment with hydrazine removes the phthalidyl protecting group after which the R 5 and R 2 ester group can be removed as described previously to yield the corresponding diacid compounds of formula I.
The phosphonochloridates of formula V can be prepared by treating a phthalidyl protected alkylbromide of the formula ##STR19## with a trialkylphosphite of the formula ##STR20## to yield the diester of the formula ##STR21## Treatment of this diester with trimethylsilylbromide yields the phosphonic acid of the formula ##STR22## The acid of formula X can then be treated with phosphorus pentachloride and an alcohol of the formula ##STR23## in the presence of triethylamine to give the compound of formula V.
The compounds of formula I wherein R 4 is ##STR24## are prepared as follows. A protected amine of the formula ##STR25## wherein Ts is tolylsulfonyl, i.e., ##STR26## is reacted with sodium diethyl phosphonate, i.e., ##STR27## to yield the intermediate of the formula ##STR28## Treatment with hydrogen bromide (48%) in the presence of phenol with heat yields the aminophosphonic acid of the formula ##STR29##
The aminophosphonic acid of formula XIV is then reacted with benzyloxycarbonyl chloride or phthalic anhydride to yield ##STR30## wherein Prot is benzyloxycarbonyl or phthalidyl. The acid of formula XV is then converted to the phosphonochloridate of the formula ##STR31## wherein R 5 is lower alkyl, benzyl or benzhydryl by treating XV with triethylorthoformate, benzyl bromide, etc., followed by treatment with thionyl chloride or phosphorus pentachloride.
The acid chloride of formula XVI is then coupled with the lactam ester of formula III to yield the intermediate of the formula ##STR32## Removal of the protecting group such as by hydrogenation where Prot is benzoyloxycarbonyl or by treatment with hydrazine where Prot is phthalidyl followed by reaction with the acid chloride of the formula ##STR33## yields the desired products of formula I.
If R 1 is amino or hydroxy substituted lower alkyl then the amino or hydroxy group should be protected during the coupling reaction. Suitable protecting groups include benzyloxycarbonyl, t-butoxycarbonyl, benzyl, benzhydryl, etc. The protecting group is removed by hydrogenation, treatment with acid, or by other known methods following completion of the reaction.
The lactam esters of formula III are prepared according to ring closure processes described in the literature and the Harris et al. applications described above.
Preferred compounds of this invention are those of formula I wherein:
R 4 is alkyl of 1 to 10 carbons. ##STR34## R 6 and R 7 are selected from lower alkyl of 1 to 4 carbons and ##STR35## especially wherein R 6 is phenyl and R 7 is benzyl or phenethyl.
m is zero, one, two, or three.
s is zero or an integer from 1 to 7.
t is an integer from 1 to 8.
R 14 is hydrogen, methyl, methoxy, methylthio, chloro, bromo, fluoro, or hydroxy.
R 1 is hydrogen, lower alkyl of 1 to 4 carbons, or --(CH 2 ) 4 --NH 2 .
R 3 is hydrogen, lower alkyl of 1 to 4 carbons, or ##STR36## R 5 and R 2 are independently selected from hydrogen, lower alkyl of 1 to 4 carbons, alkali metal salt, or ##STR37## R 10 is hydrogen, straight or branched chain lower alkyl of 1 to 4 carbons, or cyclohexyl.
R 11 is straight or branched chain lower alkyl of 1 to 4 carbons, cyclohexyl or phenyl.
Most preferred compounds of this invention are those of formula I wherein:
n is one or two.
R 4 is alkyl of 1 to 10 carbons or ##STR38## wherein s is zero or an integer from 1 to 7, especially ##STR39## R 1 is hydrogen. R 3 is hydrogen.
R 5 and R 2 are independently selected from hydrogen, alkali metal salt, and ##STR40## provided that only one of R 2 and R 2 is ##STR41## R 10 is hydrogen, straight or branched chain lower alkyl of 1 to 4 carbons, or cyclohexyl.
R 11 is straight or branched chain lower alkyl of 1 to 4 carbons.
The compounds of this invention wherein at least one of R 5 or R 2 is hydrogen form basic salts with various inorganic and organic bases which are also within the scope of the invention. Such salts include ammonium salts, alkali metal salts like lithium, sodium and potassium salts (which are preferred), alkaline earth metal salts like calcium and magnesium salts, salts with organic bases, e.g., dicyclohexylamine salt, benzathine, N-methyl-D-glucamine, salts with amino acids like arginine, lysine and the like. The nontoxic, physiologically acceptable salts are preferred, although other salts are also useful, e.g., in isolating or purifying the product. The salts are formed using conventional techniques.
The symbol * is used to represent various asymmetric centers which may be present in the compounds of formula I. Thus, the compounds of this invention can accordingly exist in diastereoisomeric forms or in mixtures thereof. The above described processes can utilize racemates, enantiomers or diasteromers as starting materials. When diastereomeric products are prepared, they can be separated by conventional chromatographic or fractional crystallization methods.
The compounds of formula I, and the physiologically acceptable salt thereof, are hypotensive agents. They inhibit the conversion of the decapeptide angiotensin I to angiotensin II and, therefore, are useful in reducing or relieving angiotensin related hypertension. The action of the enzyme renin on angiotensinogen, a pseudoglobulin in blood plasma, produces angiotensin I. Angiotensin I is converted by angiotensin converting enzyme (ACE) to angiotensin II. The latter is an active pressor substance which has been implicated as the causative agent in several forms of hypertension in various mammalian species, e.g., humans. The compounds of this invention intervene in the angiotensinogen→(renin)→angiotensin I→angiotensin II sequence by inhibiting angiotensin converting enzyme and reducing or eliminating the formation of the pressor substance angiotensin II. Thus by the administration of a composition containing one (or a combination) of the compounds of this invention, angiotensin dependent hypertension in a species of mammal (e.g., humans) suffering therefrom is alleviated. A single dose, or preferably two to four divided daily doses, provided on a basis of about 0.1 to 100 mg. per kilogram of body weight per day is appropriate to reduce blood pressure. The substance is preferably administered orally, but parenteral routes such as the subcutaneous, intramuscular, intravenous or intraperitoneal routes can also be employed.
The compounds of this invention can also be formulated in combination with a diuretic for the treatment of hypertension. A combination product comprising a compound of this invention and a diuretic can be administered in an effective amount which comprises a total daily dosage of about 30 to 600 mg., preferably about 30 to 330 mg. of a compound of this invention, and about 15 to 300 mg., preferably about 15 to 200 mg. of the diuretic, to a mammalian species in need thereof. Exemplary of the diuretics contemplated for use in combination with a compound of this invention are the thiazide diuretics, e.g., chlorothiazide, hydrochlorothiazide, flumethiazide, hydroflumethiazide, bendroflumethiazide, methyclothiazide, trichlormethiazide, polythiazide or benzthiazide as well as ethacrynic acid, ticrynafen, chlorthalidone, furosemide, musolimine, bumetanide, triamterene, amiloride and spironolactone and salts of such compounds.
The compounds of formula I can be formulated for use in the reduction of blood pressure in compositions such as tablets, capsules or elixirs for oral administration, or in sterile solutions or suspensions for parenteral administration. About 10 to 500 mg. of a compound of formula I is compounded with physiologically acceptable vehicle, carrier, excipient, binder, preservative, stabilizer, flavor, etc., in a unit dosage form as called for by accepted pharmaceutical practice. The amount of active substance in these compositions or preparations is such that a suitable dosage in the range indicated is obtained.
The following examples are illustrative of the invention. Temperatures are given in degrees centigrade. AG-50W-X8 refers to a crosslinked polystyrene-divinylbenzene sulfonic acid cation exchange resin. HP-20 refers to a porous crosslinked polystyrene divinylbenzene polymer resin.
EXAMPLE 1
(S)-3-[[Hydroxy(4-phenylbutyl)phosphinyl]amino]-2-oxo-1-piperidineacetic acid, dilithium salt
(a) L-Ornithine, ethyl ester, hydrochloride (1:2)
A heterogeneous mixture of L-ornithine, hydrochloride (7.0 g., 41.5 mmole) and ethanol (200 ml.) at 0° (ice bath) is treated dropwise with thionyl chloride (4.5 ml., 1.5 eq.), then refluxed for 3.5 hours under argon. The ethanol, sulfur dioxide and excess thionyl chloride are removed in vacuo and the resulting crystalline solid is triturated with ether (three times), collected by filtration, and washed with ether to give 9.4 g. of L-ornithine, ethyl ester, hydrochloride (1:2) as a white crystalline solid. A small amount is triturated with hot acetonitrile to give an analytical sample; m.p. 175-176.0. TLC (7:2:1, isopropanol/conc. NH 4 OH/water) single spot at R f =0.50.
Anal. calc'd. for C 7 H 16 N 2 O 2 .2HCl: C, 36.06; H, 7.78; N, 12.02; Cl, 30.41 Found: C, 35.98; H, 7.91; N, 12.02; Cl, 30.29.
(b) (S)-3-Amino-2-oxopiperidine
L-Ornithine, ethyl ester, hydrochloride (1:2) (5.0 g., 21.4 mmole) is treated with 1M sodium ethoxide (42.8 ml., 2.0 eq.) at 25° in an argon atmosphere. After 20 minutes the ethanol is evaporated, the residue is taken up in ethyl acetate and the sodium chloride is filtered off through a Celite bed. The ethyl acetate is evaporated and the resulting off-white solid is triturated with isopropyl ether to give 2.2 g. of (S)-3-amino-2-oxopiperidine as a white crystalline solid. A small protion is recrystallized from isopropyl ether to give fine white needles; m.p. 103°-109° (very hygroscopic).
(c) (S)-3-[[(Phenylmethoxy)carbonyl]amino]-2-oxopiperidine
A heterogeneous mixture of (S)-3-amino-2-oxopiperidine (1.7 g., 14.9 mmole), dry tetrahydrofuran (10 ml.), and diisopropylethylamine (3.6 ml., 1.4 eq.) at 0° (ice bath) under argon is treated with benzyl chloroformate (2.5 ml., 1.2 eq.). After 3 hours, the reaction mixture is diluted with ethyl acetate, and washed successively with water, 5% potassium bisulfate, and brine, dried (MgSO 4 ), and evaporated to give 3.9 g. of a crude white solid. This material is triturated with isopropyl ether to give 3.3 g. of (S)-3-[[(phenylmethoxy)carbonyl]amino]-2-oxopiperidine as a white solid. TLC (ethyl acetate) one spot at R f =0.20. A portion is recrystallized from isopropyl ether to give a white crystalline solid; m.p. 100°-102°.
[α] D =17.6° (c=1.0, methanol).
Anal. calc'd. for C 13 H 16 N 2 O 3 : C, 62.89; H, 6.49; N, 11.28 Found: C, 62.76; H, 6.47; N, 11.22.
(d) (S)-3-[[(Phenylmethoxy)carbonyl]amino]-2-oxopiperidineacetic acid, ethyl ester
A mixture of (S)-3-[[(phenylmethoxy)carbonyl]amino]-2-oxopiperidine (2.9 g., 11.7 mmole), dry tetrahydrofuran (15 ml.), and potassium t-butoxide (1.7 g., 1.3 eq.) at 0° (ice bath) is stirred for 20 minutes under argon and then is treated with ethyl bromoacetate (2.0 ml., 1.5 eq.). The ice bath is removed and the resulting reaction mixture is stirred for 5 hours. The reaction mixture is diluted with ethyl acetate, washed with water and brine, dried (MgSO 4 ), and evaporated. The residue (4.4 g.) is chromatographed on silica (130 g.) eluting with hexane/ethyl acetate (4:3) to give 3.3 g. of (S)-3-[[(phenylmethoxy)carbonyl]amino]-2-oxopiperidineacetic acid, ethyl ester as a colorless oil. TLC (4:3, hexane/ethyl acetate) single spot at R f =0.15.
(e) (S)-3-Amino-2-oxopiperidineacetic acid, ethyl ester
(S)-3-[[(Phenylmethoxy)carbonyl]amino]-2-oxopiperidineacetic acid (1.6 g., 4.8 mmole), 10% palladium on carbon catalyst (500 mg.), and methanol (50 ml.) is hydrogenated on the Parr apparatus at 50 psi for 2 hours. The catalyst is removed by filtration (Celite bed) and the methanol evaporated to give 1.0 g. of (S)-3-amino-2-oxopiperidineacetic acid, ethyl ester as an oil.
(f) Ethoxy(4-phenylbutyl)phosphinyl chloride
A mixture of 4-phenylbutyl chloride (8.0 g., 47.5 mmole) and triethylphosphite (15.0 ml., 72 mmole) is heated at reflux (bath temperature 185°) under argon for 41.5 hours. Distillation of the mixture gives 10.8 g. of diethyl(4-phenylbutyl)phosphonate as a colorless liquid; b.p. 152°-154° (1.0 mm of Hg.).
A mixture of diethyl(4-phenylbutyl)phosphonate (0.73 g., 2.6 mmole), benzene (10 ml.) and phosphorus pentachloride (1.0 eq.) is refluxed under argon for 30 minutes. The benzene and phosphorus oxychloride are removed in vacuo to give ethoxy(4-phenylbutyl)phosphinyl chloride.
(g) (S)-3-[[Ethoxy(4-phenylbutyl)phosphinyl]amino]-2-oxo-1-piperidineacetic acid, ethyl ester
The ethoxy(4-phenylbutyl)phosphinyl chloride from part (f) is taken up in dry methylene chloride (5 ml.). The 3-amino-2-oxopiperidienacetic acid, ethyl ester from part (e) is taken up in methylene chloride (5 ml.) and added to the above. The resulting solution is cooled to 0° (ice bath) and treated dropwise with triethylamine (1.0 ml., 1.5 eq.) in methylene chloride (2 ml.) for 5 minutes in an argon atmosphere. After 30 minutes, the ice bath is removed and the mixture is stirred for an additional 1 hour. The reaction mixture is then diluted with ethyl acetate, washed successively with saturated sodium bicarbonate, water, and brine, dried (MgSO 4 ) and evaporated. The residue (2.3 g.) is chromatographed on silica (100 g.) eluting with acetone/hexane (2:1) to give 1.1 g. of (S)-3-[[ethoxy(4-phenylbutyl)phosphinyl]amino]-2-oxo-1-piperidineacetic acid, ethyl ester as an oil. TLC (2:1, acetone/hexane) single spot at R f =0.20.
(h) (S)-3-[[Hydroxy(4-phenylbutyl)phosphinyl]amino]-2-oxo-1-piperidineacetic acid, dilithium salt
A mixture of the ester product from part (g) (1.1 g., 2.6 mmole), dry methylene chloride (7 ml.), and bromotrimethylsilane (0.6 ml., 1.7 eq.) in an argon atmosphere at room temperature is stirred for 40 hours. The methylene chloride and excess bromotrimethylsilane are removed in vacuo and the residue is taken up in dioxane (10 ml.) and treated with 1N lithium hydroxide (9.1 ml., 3.5 eq.). A white precipitate appears but most of it returns to solution to leave a milky solution. After 2 hours, the dioxane is evaporated. The heterogeneous solution is filtered, and the filtrate is chromatographed on an HP-20 (200 ml.) column eluting with a linear gradient of water→acetonitrile (0→90%). The fractions containing the desired product are combined, evaporated to a small volume, filtered (millipore), and lyophilized to give 480 mg. of (S)-3-[[hydroxy(4-phenylbutyl)phosphinyl]amino]-2-oxo-1-piperidineacetic acid, dilithium salt as a dense white solid; m.p. darkens at 185°. [α] D =-4.9° (c=1.0, water). TLC (7:2:1, isopropanol/NH 4 OH/water) single spot at R f =0.50.
Anal. calc'd. for C 17 H 23 N 2 O 5 PLi 2 .0.5H 2 O: C, 52.46; H, 6.21; N, 7.20; P, 7.9 Found: C, 52.38; H, 6.42; N, 7.12; P, 7.8.
EXAMPLE 2
(S)-Hexahydro-3-[[hydroxy(4-phenylbutyl)phosphinyl]amino]-2-oxo-1H-azepine-1-acetic acid, dilithium salt
(a) N 2 -[(1,1-Dimethylethoxy)carbonyl]-N 6 -[(phenylmethoxy)carbonyl]-L-lysine, methyl ester
Cesium carbonate (2.14 g., 6.55 mmole) is added to a mixture of N 2 -[(1,1-dimethylethoxy)carbonyl]-N 6 -[(phenylmethoxy)carbonyl]-L-lysine (5.0 g., 13.10 mmole) and 20% aqueous methanol (30 ml.). The solution becomes homogeneous after 5 minutes, the methanol is stripped, and the residual water is removed azetropically with acetonitrile (twice). The resulting oil is taken up in dry methylene chloride (10 ml.) and treated with methyl iodide (1.6 ml., 2.0 eq.) at 25° in an argon atmosphere. After 4 hours the reaction mixture is taken up in ethyl acetate and washed successively with water, saturated sodium bicarbonate and brine, dried (MgSO 4 ), and evaporated. The residue (4.7 g.) is chromatographed on silica (160 g.) eluting with hexane/ethyl acetate (3:1) to give 4.0 g. of N 2 -[(1,1-dimethylethoxy)carbonyl]-N 6 -[(phenylmethoxy)carbonyl]-L-lysine, methyl ester as an oil after evaporation. TLC (hexane/ethyl acetate; 2:1) major spot at R f =0.3.
(b) (S)-3-[[(1,1-Dimethylethoxy)carbonyl]amino]-2-oxo-hexahydro-1H-azepine
A mixture of N 2 -[(1,1-dimethylethoxy)carbonyl]-N 6 -[(phenylmethoxy)carbonyl]-L-lysine, methyl ester (4.0 g., 10.1 mmole), 10% palladium on carbon catalyst (1.0 g.), and methanol (60 ml.) is hydrogenated on the Parr apparatus at 50 psi for 2 hours. The catalyst is removed by filtration (Celite bed) and the methanol evaporated. The resulting oil is taken up in xylene (30 ml.) and refluxed for 18 hours in an argon atmosphere. The xylene is diluted with ethyl acetate and washed successively with 5% potassium bisulfate, saturated sodium bicarbonate and brine, dried (MgSO 4 ), and evaporated to a crystalline solid. The solid is taken up in methylene chloride and chromatographed on silica (60 g.) eluting with ethyl acetate/hexane (1:1) to give 1.5 g. of (S)-3-[[(1,1-dimethylethoxy)carbonyl]amino]-2-oxo-hexahydro-1H-azepine as a white crystalline solid; m.p. 147°-149°; [α] D =+4.5° (1.0, methanol). TLC (ethyl acetate) shows a single spot at R f =0.50.
Anal. calc'd. for C 11 H 20 N 2 O 3 : C, 57.87; H, 8.83; N,12.27 Found: C, 58.12; H, 8.63; N,12.26.
(c) (S)-3-[[(1,1-Dimethylethoxy)carbonyl]amino]-2-oxo-hexahydro-1H-azepine-1-acetic acid, ethyl ester
A mixture of (S)-3-[[(1,1-dimethylethoxy)carbonyl]amino]-2-oxo-hexahydro-1H-azepine (1.4 g., 6.1 mmole), dry tetrahydrofuran (10 ml.), and potassium t-butoxide (0.9 g., 1.3 eq.) is stirred under argon at room temperature for 5 minutes, then treated with ethyl bromoacetate (1.1 ml., 1.7 eq.). After 1 hour, the reaction mixture is diluted with ethyl acetate and washed successively with saturated sodium bicarbonate, 5% potassium bisulfate, and brine, dried (MgSO 4 ), and evaporated. The orange residue (2.4 g.) is chromatographed on silica (65 g.) eluting with ethyl acetate/hexane (3:1) to give 1.65 g. of (S)-3-[[(1,1-dimethylethoxy)carbonyl]amino]-2-oxo-hexahydro-1H-azepine-1-acetic acid, ethyl ester as a colorless oil. TLC (hexane/ethyl acetate; 1:1) single spot at R f =0.4.
(d) (S)-3-Amino-2-oxo-hexahydro-1H-azepine-1-acetic acid, ethyl ester, monohydrochloride
A mixture of (S)-3-[[(1,1-dimethylethoxy)carbonyl]amino]-2-oxo-hexahydro-1H-azepine-1-acetic acid, ethyl ester (1.6 g., 5.0 mmole) and ethyl acetate (5 ml.) at 0° (ice bath) is treated with cold saturated hydrochloric acid/ethyl acetate (40 ml.). After stirring for 45 minutes at 0°, nitrogen is passed through the solution to remove excess hydrochloric acid. The ethyl acetate is evaporated and the resulting oil is triturated with ether (3 times) to give 1.1 g. of (S)-3-amino-2-oxo-hexahydro-1H-azepine-1-acetic acid, ethyl ester, monohydrochloride as a very hygroscopic white crystalline solid after drying in vacuo over phosphorus pentoxide. TLC (methylene chloride/acetic acid/methanol; 8:1:1) major spot at R f =0.32.
(e) (S)-Hexahydro-3-[[(ethoxy(4-phenylbutyl)phosphinyl]amino]-2-oxo-1H-azepine-1-acetic acid, ethyl ester
A mixture of ethoxy(4-phenylbutyl)phosphinyl chloride [4.4 mmole; prepared as set forth in Example 1(f)], dry tetrahydrofuran (10 ml.), and 3-amino-2-oxo-hexahydro-1H-azepine-1-acetic acid, ethyl ester, monohydrochloride (1.0 g., 4.0 mmole) at 0° (ice bath) in an argon atmosphere is treated dropwise with triethylamine (1.7 ml., 3.0 eq.) in tetrahydrofuran (5 ml.) over 2 minutes. After 20 minutes, the ice bath is removed and the reaction mixture is stirred for an additional 1.5 hours. The reaction mixture is diluted with ethyl acetate and washed successively with saturated sodium bicarbonate, 5% potassium bisulfate, and brine, dried (MgSO 4 ) and evaporated. The residue (2.1 g.) is chromatographed on silica (65 g.) eluting with ethyl acetate then acetone to give 1.0 g. of (S)-hexahydro-3-[[ethoxy(4-phenylbutyl)phosphinyl]amino]-2-oxo-1H-azepine-1-acetic acid, ethyl ester as an oil after evaporation. TLC (ethyl acetate) single spot at R f =0.1.
(f) (S)-Hexahydro-3-[[hydroxy(4-phenylbutyl)phosphinyl]amino]-2-oxo-1H-azepine-1-acetic acid, dilithium salt
A mixture of the diester product from part (e) (1.0 g., 2.3 mmole), methylene chloride (3 ml.), and bromotrimethylsilane (0.9 ml., 3.0 eq.) is stirred at 25° under argon for 16 hours. The methylene chloride and excess bromotrimethylsilane are removed in vacuo and the residue is taken up in acetonitrile (7 ml.) and 1N lithium hydroxide (7 ml., 3.0 eq.). After 3 hours the acetonitrile is evaporated, the aqueous solution is filtered, and chromatographed on an HP-20 (200 ml.) column eluting with a linear gradient water-acetonitrile (0→90% acetonitrile). The fractions containing the desired product are combined, evaporated to a small volume, filtered (millipore) and lyophilized to give 680 mg. of (S)-hexahydro-3-[[hydroxy(4-phenylbutyl)phosphinyl]amino]-2-oxo-1H-azepine-1-acetic acid, dilithium salt as a fluffy white solid; m.p. greater than 250°; [α] D =+14.8° (c=0.5, water). TLC (isopropanol/conc. NH 4 OH/water; 7:2:1) single spot at R f =0.72.
Anal. Calc'd. for C 18 H 25 N 2 O 5 PLi 2 .1.5H 2 O: C, 51.32; H, 6.69; N, 6.65; P, 7.3 Found: C, 51.20; H, 6.33; N, 6.62; P, 7.3.
EXAMPLES 3-22
Following the procedures of Examples 1 and 2, the lactam ester shown below in Col. I is reacted with the alkoxy(alkyl)phosphinyl chloride shown in Col. II to give the ester product shown in Col. III. The R 2 and R 5 ester groups can be removed to give the corresponding diacid which can then be converted to a salt or in the case of Examples 20 to 22 only the R 5 ester group would be removed. The R 1 protecting group shown in Examples 6 and 10 would be removed as the last step of the synthesis. ##STR42##
__________________________________________________________________________Ex-ample n R.sub.3 R.sub.1 R.sub.2 R.sub.4 R.sub.5__________________________________________________________________________ 3 1 H H C.sub.2 H.sub.5 C.sub.2 H.sub.5 4 2 ##STR43## CH.sub.3 C.sub.2 H.sub.5 ##STR44## C.sub.2 H.sub.5 5 1 CH.sub.3 H ##STR45## ##STR46## ##STR47## 6 2 C.sub.2 H.sub.5 ##STR48## C.sub.2 H.sub.5 H.sub.3 C(CH.sub.2).sub.7 C.sub.2 H.sub.5 7 1 ##STR49## H C.sub.2 H.sub.5 H.sub.3 C(CH.sub.2).sub.3 C.sub.2 H.sub.5 8 2 ##STR50## CF.sub.3 C.sub.2 H.sub.5 ##STR51## C.sub.2 H.sub.5 9 1 ##STR52## C.sub.2 H.sub.5 C.sub.2 H.sub.5 ##STR53## C.sub.2 H.sub.510 2 ##STR54## ##STR55## C.sub.2 H.sub.5 ##STR56## C.sub.2 H.sub.511 1 C(CH.sub.3).sub.3 H C.sub.2 H.sub.5 ##STR57## C.sub.2 H.sub.512 2 H H C.sub.2 H.sub.5 ##STR58## C.sub.2 H.sub.513 1 H H C.sub.2 H.sub.5 ##STR59## C.sub.2 H.sub.514 3 H H C.sub.2 H.sub.5 ##STR60## C.sub.2 H.sub.515 4 H H C.sub.2 H.sub.5 ##STR61## C.sub.2 H.sub.516 1 H H C.sub.2 H.sub.5 ##STR62## C.sub.2 H.sub.517 2 CH.sub.3 CH.sub.3 C.sub.2 H.sub.5 ##STR63## C.sub.2 H.sub.518 1 H CH.sub.3 C.sub.2 H.sub.5 ##STR64## C.sub.2 H.sub.519 2 H H C.sub.2 H.sub.5 ##STR65## C.sub.2 H.sub.520 1 ##STR66## H ##STR67## ##STR68## C.sub.2 H.sub.521 2 H H ##STR69## ##STR70## C.sub.2 H.sub.522 3 H CH.sub.3 ##STR71## ##STR72## C.sub.2 H.sub.5__________________________________________________________________________
EXAMPLE 23
(S)-3-[[(6-Aminohexyl)hydroxyphosphinyl]amino]-2-oxo-1-piperidineacetic acid, dilithium salt
(a) N-(6-Bromohexyl)phthalimide
A mixture of crystalline 6-aminohexanol (11.7 g., 0.1 mole) and phthalic anhydride (14.8 g., 0.1 mole) is heated at 170° for 1.5 hours in an argon atmosphere. The evolved water is then removed with heat and argon flow. The reaction mixture is cooled to 100° and phosphorus tribromide (7.2 ml., 0.086 mole) is added in portions via gas tight syringe to the reaction mixture. A vigorous reaction occurs with each addition. After addition is complete, the reaction mixture is heated at 100° for an additional 30 minutes. The cooled reaction mixture is diluted with ethanol (20 ml.) then poured over ice-water and refrigerated overnight. A yellow solid is filtered and washed several times with cold water until the filtrate is nearly neutral. The crude solid is recrystallized from ethanol to give 21.0 g. of N-(6-bromohexyl)phthalimide as a pale yellow solid; m.p. 54°-55°. TLC (hexane-ethyl acetate; 1:1) shows a major spot at R f =0.8.
(b) (6 -Phthalimidohexyl)phosphonic acid, diethyl ester
A mixture of N-(6-bromohexyl)phthalimide (5.5 g., 17.7 mmole) and triethylphosphite (10.0 ml., 58.4 mmole) is refluxed (bath temperature 160°-165°) under argon for 16 hours. The volatiles are removed by distillation at 100° (bath temperature), 0.5 mm. of Hg to leave a pale yellow viscous oil. The crude product is purified by flash chromatography on silica gel (100 g.) eluting with acetone-hexane (1:2) to give 6.00 g. of (6-phthalimidohexyl)phosphonic acid, diethyl ester as a colorless viscous oil. TLC (acetone-hexane; 1:1) shows a single spot at R f -0.40.
(c) Ethoxy(6-phthalimidohexyl)phosphinyl chloride, ethyl ester
A mixture of (6-phthalimidohexyl)phosphonic acid, diethyl ester, benzene, and phosphorus pentachloride is refluxed according to the procedure of Example 1(f) to give ethoxy(6-phthalimidohexyl)phosphinyl chloride.
(d) (S)-3-[[Ethoxy(6-phthalimidohexyl)phosphinyl]amino]-2-oxo-1-piperidineacetic acid, ethyl ester
Ethoxy(6-phthalimidohexyl)phosphinyl chloride and (S)-3-amino-2-oxopiperidineacetic acid, ethyl ester are reacted according to the procedure of Example 1(g) to give (S)-3-[[ethoxy(6-phthalimidohexyl)phosphinyl]amino]-2-oxo-1-piperidineacetic acid, ethyl ester.
(e) (S)-3-[[(6-Aminohexyl)ethoxyphosphinyl]amino]-2-oxo-1-piperidineacetic acid, ethyl ester
A solution of (S)-3-[[ethoxy(6-phthalimidohexyl)phosphinyl]amino]-2-oxo-1-piperidineacetic acid, ethyl ester in dioxane is treated with hydrazine hydrate and stirred at room temperature under argon. After the reaction is completed, the mixture is diluted with toluene and the solvents decanted. The residue is triturated with methylene chloride and filtered. The combined filtrate is evaporated to dryness to give (S)-3-[[(6-aminohexyl)ethoxyphosphinyl]amino]-2-oxo-1-piperidineacetic acid, ethyl ester.
(f) (S)-3-[[(6-Aminohexyl)hydroxyphosphinyl]amino]-2-oxo-1-piperidineacetic acid, dilithium salt
The diethyl ester product from part (e) is treated with bromotrimethylsilane in methylene chloride and the residue is taken up in acetonitrile and treated with 1N lithium hydroxide according to the procedure of Example 1(h). Work-up of the product according to the procedure of Example 1(h) gives (S)-3-[[(6-aminohexyl)hydroxyphosphinyl]amino]-2-oxo-1-piperidineacetic acid, dilithium salt.
EXAMPLES 24-27
Following the procedure of Example 23 but employing the aminoalcohol listed in Col. I one obtains the product listed in Col. II.
______________________________________Ex. Col. I Col. II______________________________________24 3-aminopropanol (S)--3-[[(3-Aminopropyl)- hydroxyphosphinyl]amino]- 2-oxo-1-piperidineacetic acid, dilithium salt25 2-aminoethanol (S)--3-[[(2-Aminoethyl)- hydroxyphosphinyl]amino]- 2-oxo-1-piperidineacetic acid, dilithium salt26 4-aminobutanol (S)--3-[[(4-Aminobutyl)- hydroxyphosphinyl]amino]- 2-oxo-1-piperidineacetic acid, dilithium salt27 8-aminooctanol (S)--3-[[(8-Aminooctyl)- hydroxyphosphinyl]amino]- 2-oxo-1-piperidineacetic acid, dilithium salt______________________________________
Similarly, by employing the lactam esters of Examples 2 to 22 within the procedure of Examples 23 to 27, other compounds within the scope of the invention are obtained.
EXAMPLE 28
(S)-3-[[(2-(Benzoylamino)-3-phenylpropyl]hydroxyphosphinyl]amino]-2-oxo-1-piperidineacetic acid, dilithium salt
(a) 4-Methylbenzenesulfonic acid, 2-[[(4-methylphenyl)sulfonyl]amino]-3-phenylpropyl ester
A solution of d,l-phenylalaninol, hydrochloride (9.4 g., 50.1 mmole) in dry pyridine (35 ml.) at 0° (ice bath) is treated with p-toluenesulfonyl chloride (19.4 g., 102 mmole) in small portions over a 15 minute period. The mixture is allowed to come to room temperature and stirred overnight. The mixture is evaporated to dryness and the residue partitioned between ethyl acetate and 5% potassium bisulfate. The ethyl acetate layer is washed successively with 5% potassium bisulfate, saturated sodium bicarbonate and saturated sodium chloride, dried (Na 2 SO 4 ), and evaporated. The dark residue is filtered through a pad of silica gel eluting with methylene chloride then methylene chloride-ethyl acetate (1:1). Evaporation of the solvents and trituration of the residue with ether gives 13.93 g. of 4-methylbenzenesulfonic acid, 2-[[(4-methylphenyl)sulfonyl]amino]-3-phenylpropyl ester as white crystals; m.p. 95°-96°; TLC (ethyl acetate/hexane; 1:2) spot at R f =0.39. A sample is recrystallized from diisopropyl ether; m.p. 96°-98°.
(b) [2-[[(4-Methylphenyl)sulfonyl]amino]-3-phenylpropyl]phosphonic acid, diethyl ester
A solution of diethylphosphite (7.3 g., 52.9 mmole) in dry tetrahydrofuran (100 ml.) is treated with sodium hydride 50% oil dispersion (2.20 g., 45.8 mmole) in small portions under argon. The mixture is then refluxed for 30 minutes, cooled to room temperature, and treated with 4-methylbenzenesulfonic acid, 2-[[(4-methylphenyl)sulfonyl]amino]-3-phenylpropyl ester (6.9 g., 15 mmole). After 15 minutes, a white solid separates; additional tetrahydrofuran (75 ml.) is added and stirring continued overnight. After stirring at room temperature overnight, the mixture is refluxed for one hour, cooled and partitioned between ethyl acetate (75 ml.) and 5% potassium bisulfate (50 ml.). The ethyl acetate phase is washed successively with 5% potassium bisulfate, saturated sodium bicarbonate and saturated sodium chloride, dried (Na 2 SO 4 ), and evaporated. The residue is triturated with hexane to give 5.9 g. of [2-[[(4-methylphenyl)sulfonyl]amino]-3-phenylpropyl]phosphonic acid, diethyl ester as an off-white solid; m.p. 86°-89°; TLC (ethyl acetate) spot at R f =0.48. A sample is recrystallized from diisopropyl ether; m.p. 94°-95°.
(c) (2-Amino-3-phenylpropyl)phosphonic acid
A mixture of [2-[[(4-methylphenyl)sulfonyl]amino]-3-phenylpropyl]phosphonic acid, diethyl ester (5.9 g., 13.9 mmole), phenol (8.0 g., 85.1 mmole), and 48% aqueous hydrobromic acid (50 ml.) is refluxed for 5.5 hours. The cooled mixture is diluted with water (50 ml.) and washed with ethyl acetate (2×50 ml.). The aqueous phase is evaporated to dryness, taken up in water (30 ml.) and evaporated again. This is repeated twice more. Finally, the residue is taken up in water and applied to an AG 50 W-X2 (H + form) column (60 ml. bed volume) and eluted first with water then with 5% pyridine-water. The fractions containing the desired product are combined and evaporated to dryness. The solid residue is triturated with acetonitrile to give 2.55 g. of (2-amino-3-phenylpropyl)phosphonic acid as an off-white crystalline solid; m.p. 347° (dec.); TLC (isopropanol/conc. NH 4 OH/water; 7:2:1) spot at R f =0.27.
(d) (2-Phthalimido-3-phenylpropyl)phosphonic acid
A mixture of (2-amino-3-phenylpropyl)phosphonic acid (2.0 g., 9.3 mmole) and phthalic anhydride (1.55 g., 10.5 mmole) is fused in a flask under argon at 195°-200° (bath temperature) for 1.5 hours. The glassy dark residue is refluxed with ethyl acetate (25 ml.) until the glassy residue dissolves and a fluffy crystalline solid separates. The cooled mixture is diluted with diethyl ether (25 ml.) and filtered. The solid is washed thoroughly with diethyl ether and dried to give 2.87 g. of (2-phthalimido-3-phenylpropyl)phosphonic acid as an off-white crystalline solid; m.p. 127°-130°. A sample is crystallized from ethyl acetate; m.p. 129°-131°. TLC (isopropanol/conc. NH 4 OH/water; 7:2:1) spot at R f =0.33.
(e) (S)-3-[[[2-Phthalimido-3-phenylpropyl]ethoxyphosphinyl]amino]-2-oxo-1-piperidineacetic acid, ethyl ester
A suspension of (2-phthalimido-3-phenylpropyl)phosphonic acid in dry benzene is treated with phosphorus pentachloride and stirred at room temperature under argon for an hour. The mixture is then refluxed for 15 minutes, cooled and evaporated to dryness to room temperature (0.5 mm. of Hg). The residue is taken up in dry methylene chloride and reacted successively with a mixture of ethanol (1 eq.) and triethylamine (1 eq.) in methylene chloride and (S)-3-amino-2-oxopiperidineacetic acid, ethyl ester according to the procedure of Example 1(g). Work up of the reaction mixture according to the procedure of Example 1(g) yields (S)-3-[[[2-phthalimido-3-phenylpropyl]ethoxyphosphinyl]amino]-2-oxo-1-piperidineacetic acid, ethyl ester.
(f) (S)-3-[[[2-(Benzoylamino)-3-phenylpropyl]ethoxyphosphinyl]amino]-2-oxo-1-piperidineacetic acid, ethyl ester
A solution of (S)-3-[[[2-phthalimido-3-phenylpropyl]ethoxyphosphinyl]amino]-2-oxo-1-piperidineacetic acid, ethyl ester in dioxane is treated with hydrazine hydrate and stirred for 24 hours at room temperature. The mixture is then partitioned between ethyl acetate-water and the ethyl acetate phase is washed with water and saturated sodium chloride, dried (Na 2 SO 4 ), and evaporated. The residue is taken up in dry toluene and refluxed for one hour. The mixture is filtered, treated with triethylamine and benzoyl chloride and stirred at room temperature for 30 minutes. The mixture is diluted with ethyl acetate, washed successively with 5% potassium bisulfate, saturated sodium bicarbonate, and saturated sodium chloride, dried (Na 2 SO 4 ), and evaporated. The residue is chromatographed on silica gel to give (S)-3-[[[2-(benzoylamino)-3-phenylpropyl]ethoxyphosphinyl]amino]-2-oxo-1-piperidineacetic acid, ethyl ester.
(g) (S)-3-[[[2-(Benzoylamino)-3-phenylpropyl]hydroxyphosphinyl]amino]-2-oxo-1-piperidineacetic acid, dilithium salt
The diethyl ester product from part (f) is treated with bromotrimethylsilane in methylene chloride and the residue is taken up in acetonitrile and treated with 1N lithium hydroxide according to the procedure of Example 1(h). Work up of the product according to the procedure of Example 1(h) gives (S)-3-[[[2-(benzoylamino)-3-phenylpropyl]hydroxyphosphinyl]amino]-2-oxo-1-piperidineacetic acid, dilithium salt.
EXAMPLES 29-38
Following the procedure of Example 28 but employing the protected amine shown in Col. I and the phosphonic diester shown in Col. II, one obtains, after removal of the tosyl protecting group and reaction with phthalic anhydride, the phosphonic acid shown in Col. III. The acid of Col. III is then converted to the phosphonic acid ester chloride shown in Col. IV which is then coupled with the lactam ester shown in Col. V to yield the intermediate shown in Col. VI. Removal of the phthalidyl group and reaction with the acid chloride shown in Col. VII yields the ester product shown in Col. VIII. The R 2 and R 5 ester groups can be removed to give the corresponding diacid which can then be converted to a salt or in the case of Example 38 only the R 5 ester group would be removed. The R 1 protecting group shown in Example 33 would be removed ad the last step of the synthesis. ##STR73##
__________________________________________________________________________Ex-am-ple R.sub.7 R.sub.5 n R.sub.3 R.sub.1 R.sub.2 R.sub.6__________________________________________________________________________29 C.sub.2 H.sub.5 2 H H C.sub.2 H.sub.5 ##STR74##30 ##STR75## C.sub.2 H.sub.5 4 H H C.sub.2 H.sub.5 ##STR76##31 ##STR77## C.sub.2 H.sub.5 2 ##STR78## CH.sub.3 C.sub.2 H.sub.5 ##STR79##32 ##STR80## C.sub.2 H.sub.5 3 CH.sub.3 H C.sub.2 H.sub.5 H.sub.3 C(CH.sub.2). sub.333 ##STR81## C.sub.2 H.sub.5 2 C.sub.2 H.sub.5 ##STR82## C.sub.2 H.sub.5 ##STR83##34 (H.sub.3 C).sub.2 HC C.sub.2 H.sub.5 1 ##STR84## H C.sub.2 H.sub.5 ##STR85##35 ##STR86## C.sub.2 H.sub.5 2 ##STR87## CF.sub.3 C.sub.2 H.sub.5 ##STR88##36 ##STR89## C.sub.2 H.sub.5 1 H H C.sub.2 H.sub.5 ##STR90##37 ##STR91## C.sub.2 H.sub.5 2 ##STR92## CH.sub.3 C.sub.2 H.sub.5 ##STR93##38 ##STR94## C.sub.2 H.sub.5 1 ##STR95## H ##STR96## ##STR97##__________________________________________________________________________
EXAMPLE 39
(S)-Hexahydro-3-[[[2-methyl-1-(1-oxopropoxy)propoxy](4-phenylbutyl)phosphinyl]amino]-2-oxo-1H-azepine-1-acetic acid, monolithium salt
(a) (S)-3-Amino-2-oxo-hexahydro-1H-azepine-1-acetic acid, phenylmethyl ester
Following the procedure of Example 2(c) but employing bromoacetic acid, phenylmethyl ester for the ethyl bromoacetate, one obtains (S)-3-[[(1,1-dimethylethoxy)carbonyl]amino]-2-oxo-hexahydro-1H-azepine-1-acetic acid, phenylmethyl ester.
Treatment of this phenylmethyl ester product with trifluoroacetic acid gives (S)-3-amino-2-oxo-hexahydro-1H-azepine-1-acetic acid, phenylmethyl ester.
(b) (S)-Hexahydro-3-[[ethoxy(4-phenylbutyl)phosphinyl]amino]-2-oxo-1H-azepine-1-acetic acid, phenylmethyl ester
Ethoxy(4-phenylbutyl)phosphinyl chloride is reacted with (S)-3-amino-2-oxo-hexahydro-1H-azepine-1-acetic acid, phenylmethyl ester according to the procedure of Example 2(e) to give (S)-hexahydro-3-[[ethoxy(4-phenylbutyl)phosphinyl]amino]-2-oxo-1H-azepine-1-acetic acid, phenylmethyl ester.
(c) (S)-Hexahydro-3-[[[2-methyl-1-(1-oxopropoxy)propoxy](4-phenylbutyl)phosphinyl]amino]-2-oxo-1H-azepine-1-acetic acid, phenylmethyl ester
A mixture of the diester product from part (b) and bis(trimethylsilyl)acetamide in methylene chloride is stirred at ambient temperature for several hours. After concentration in vacuo at 30°, methylene chloride is added followed by bromotrimethylsilane. The mixture is stirred at room temperature for several hours and concentrated in vacuo overnight. The residue is dissolved in methylene chloride and treated with triethylamine and water and again concentrated in vacuo. The residue is taken up in chloroform and treated with triethylamine, 1-chloroisobutyl propanoate, sodium chloride, and tetrabutylammonium iodide. The mixture is stirred at reflux temperature overnight. The reaction mixture is then concentrated in vacuo and ether is added to the residue. The water soluble solids separating from solution are filtered off and the ethereal filtrate is washed with water, 2% sodium thiosulfate, and brine, dried (MgSO 4 ), and concentrated in vacuo to give (S)-hexahydro-3-[[[2-methyl-1-(1-oxopropoxy)propoxy](4-phenylbutyl)phosphinyl]amino]-2-oxo-1H-azepine-1-acetic acid, phenylmethyl ester.
(d) (S)-Hexahydro-3-[[[2-methyl-1-(1-oxopropoxy)propoxy](4-phenylbutyl)phosphinyl]amino]-2-oxo-1H-azepine-1-acetic acid, monolithium salt
The diester product from part (c) is hydrogenated by treating with palladium on carbon catalyst (10%) in aqueous methanol in a Parr apparatus at 50 psi for several hours. The reaction mixture is filtered and concentrated. The residue is dissolved in ethyl acetate, treated with triethylamine, and concentrated in vacuo. The residue is dissolved in water and applied to an AG50 X 8(Li + ) column eluting with water. Fractions containing the desired product are combined and lyophilized. The lyophilate is chromatographed on an HP-20 column eluting with a linear gradient of acetonitrile/water (0→90%). Fractions containing the desired product are combined, concentrated in vacuo and the residue is dissolved in water, filtered, and lyophilized to give (S)-hexahydro-3-[[[2-methyl-1-(1-oxopropoxy)propoxy]-(4-phenylbutyl)phosphinyl]amino]-2-oxo-1H-azepine-1-acetic acid, monolithium salt.
EXAMPLES 40-45
Following the procedure of Example 39 but substituting for the 1-chloroisobutyl propanoate the alkylating agents listed below in Col. I, the products listed in Col. II are obtained.
______________________________________Ex-am-ple Col. I Col. II______________________________________40 ##STR98## (S)Hexahydro-3- [[[cyclohexyl(1- oxopropoxy)meth- oxy](4-phenyl- butyl)phos- phinyl]amino]-2- oxo-1Hazepine- 1-acetic acid, monolithium salt41 ##STR99## (S)Hexahydro-3- [[[1-(1-oxopropoxy)- ethoxy](4-ph enylbutyl)- phosphinyl] amino]- 2-oxo-1H azepine - 1-acetic acid, monolithium salt42 ##STR100## (S)Hexahydro-3- [[[(2,2-dimethyl-1- oxopropoxy)me thoxy](4- phenylbutyl) phosphinyl]amino]-2- oxo-1Hazepine- 1-acetic acid, monolithium salt43 ##STR101## (S)Hexahydro-3-[[[2- methyl-1-(1-oxobutoxy)- propoxy](4-phenylbutyl)- phosphinyl]amino]-2- oxo-1Hazepine- 1-acetic acid, monolithium salt44 ##STR102## (S)Hexahydro-3- [[[(phenylcarbonyloxy)- methoxy]- (4- phenylbutyl)phosphin- yl]amino]-2-oxo-1H azepine-1-acetic acid, monolithium salt45 ##STR103## (S)Hexahydro-3- [[[(ethoxycarbonyloxy)- methoxy]( 4- phenylbutyl)phos- phinyl]amino]-2-oxo- 1Hazepine-1-acetic acid, monolithium______________________________________ salt
Similarly, the alkylating agents of Examples 39 to 45 can be employed with the ester products of Examples 1 and 3 to 38 to yield other compounds within the scope of this invention.
EXAMPLE 46
(S)-3-[[Hydroxy(4-phenylbutyl)phosphinyl]amino]-2-oxo-1-piperidineacetic acid, disodium salt
Following the procedure of Example 1 but substituting sodium hydroxide for the lithium hydroxide in part (h), one obtains (S)-3-[[hydroxy(4-phenylbutyl)phosphinyl]amino]-2-oxo-1-piperidineacetic acid, disodium salt.
This procedure can be employed in Examples 2-45 to give the corresponding mono or disodium salt. In a similar manner, the corresponding mono or dipotassium salt can be obtained.
EXAMPLE 47
1000 tablets each containing the following ingredients:
______________________________________(S)--3-[[Hydroxy(4-phenylbutyl) 100 mg.phosphinyl]amino]-2-oxo-1-piperidineacetic acid, disodiumsaltCorn starch 50 mg.Gelatin 7.5 mg.Avicel (microcrystalline cellulose) 25 mg.Magnesium stearate 2.5 mg. 185 mg.______________________________________
are prepared from sufficient bulk quantities by mixing the (S)-3-[[hydroxy(4-phenylbutyl)phosphinyl]amino]-2-oxo-1-piperidineacetic acid, disodium salt and corn starch with an aqueous solution of the gelatin. The mixture is dried and ground to a fine powder. The Avicel and then the magnesium stearate are admixed with granulation. This mixture is then compressed in a tablet press to form 1000 tablets each containing 100 mg. of active ingredient.
In a similar manner, tablets containing 100 mg. of the product of any of Examples 2 to 45 can be prepared.
EXAMPLE 48
1000 tablets each containing the following ingredients:
______________________________________(S)--Hexahydro-3-[[hydroxy(4- 50 mg.phenylbutyl)phosphinyl]amino]-2-oxo-1H--azepine-1-acetic acid,disodium saltLactose 25 mg.Avicel 38 mg.Corn starch 15 mg.Magnesium stearate 2 mg. 130 mg.______________________________________
are prepared from sufficient bulk quantities by mixing the (S)-hexahydro-3-[[hydroxy(4-phenylbutyl)phosphinyl]amino]-2-oxo-1H-azepine-1-acetic acid, disodium salt, lactose and Avicel and then blending with the corn starch. Magnesium stearate is added and the dry mixture is compressed in a tablet press to form 1000 tablets each containing 50 mg. of active ingredient. The tablets are coated with a solution of Methocel E 15 (methyl cellulose) including as a color a lake containing yellow #6.
In a similar manner, tablets containing 50 mg. of the product of any Examples 1 and 3 to 45 can be prepared.
EXAMPLE 49
Two piece #1 gelatin capsules each containing 100 mg. of (S)-3-[[[2-(benzoylamino)-3-phenylpropyl]hydroxyphosphinyl]amino]-2-oxo-1-piperidineacetic acid, disodium salt are filled with a mixture of the following ingredients:
______________________________________(S)--3-[[[2-(Benzoylamino)-3- 100 mg.phenylpropyl]hydroxyphos-phinyl]amino]-2-oxo-1-piper-idineacetic acid, disodium saltMagnesium stearate 7 mg.Lactose 193 mg. 300 mg.______________________________________
In a similar manner, capsules containing 100 mg. of the product of any of Examples 1 to 27 and 29 to 46 can be prepared.
EXAMPLE 50
An injectable solution is prepared as follows:
______________________________________(S)--3-[[Hydroxy(4-phenyl- 500 g.butyl)phosphinyl]amino]-2-oxo-1-piperidineacetic acid,disodium saltMethyl paraben 5 g.Propyl paraben 1 g.Sodium chloride 25 g.Water for injection 5 l.______________________________________
The active substance, preservatives, and sodium chloride are dissolved in 3 liters of water for injection and then the volume is brought up to 5 liters. The solution is filtered through a sterile filter and aseptically filled into presterilized vials which are closed with presterilized rubber closures. Each vial contains 5 ml. of solution in a concentration of 100 mg. of active ingredient per ml. of solution for injection.
In a similar manner, an injectable solution containing 100 mg. of active ingredient per ml. of solution can be prepared for the product of any Examples 2 to 46.
EXAMPLE 51
1000 tablets each containing the following ingredients:
______________________________________(S)--Hexahydro-3-[[hydroxy(4- 100 mg.phenylbutyl)phosphinyl]amino]-2-oxo-1H--azepine-1-acetic acid,disodium saltAvicel 100 mg.Hydrochlorothiazide 12.5 mg.Lactose 113 mg.Corn starch 17.5 mg.Stearic acid 7 mg. 350 mg.______________________________________
are prepared from sufficient bulk quantities by slugging the (S)-hexahydro-3-[[hydroxy(4-phenylbutyl)phosphinyl]amino]-2-oxo-1H-azepine-1-acetic acid, disodium salt, Avicel and a portion of the stearic acid. The slugs are ground and passed through a #2 screen, then mixed with the hydrochlorothiazide, lactose, corn starch, and remainder of the stearic acid. The mixture is compressed into 350 mg. capsule shaped tablets in a tablet press. The tablets are scored for dividing in half.
In a similar manner, tablets can be prepared containing 100 mg. of the product of any of Examples 1 and 3 to 46. | Phosphonamide substituted lactams of the formula ##STR1## are disclosed. These compounds are useful as hypotensive agents. | 2 |
This invention claims the benefit of priority to U.S. Provisional Application Ser. No. 61/364,972 filed Jul. 16, 2010.
FIELD OF INVENTION
This invention relates to storm water treatment systems, and in particular to devices, apparatus, systems and methods for preventing backflow current problems that causes debris to overflow a storm water treatment system by utilizing a pivoting panel and/or pylon, along with an optional inflow sediment collection gap.
BACKGROUND AND PRIOR ART
Baskets and screen type systems are sometimes placed in storm water vaults in order to capture floating debris such as leaves and litter, and the like. However these screen systems can sometimes become obstructed by debris and not allow for much water to pass therethrough. When the flows are high and these screen systems can become obstructed, previously captured floatables can escape. For example, a backflow current problem can occur which can cause floating debris to be forced out of a screen system and into the vault and beyond. The backflow current problem can occur when the water flowing current within a screen system starts to flow in the opposite direction to the current flow entering into the screen system. The backflow current problem can cause a screen system to empty out of the screen system any previously captured floating debris and litter. As such, the backflow current problem can result in preventing any further collection of floating debris and litter.
FIG. 1 is a top perspective view of prior art baffle box with storm water and floatables 40 flowing through the screen system 10 . FIG. 2 is another top perspective view of the prior art baffle box 20 of FIG. 1 with a backed up screen system 10 . Referring to FIGS. 1-2 , a screen system 10 includes a baffle box 20 that is intended to remove floatables from the incoming storm water 100 that has floatables 30 , such as debris, and litter, mixed in with storm water having debris 40 . The storm water with debris 40 passes through inflow pipe 50 , where the storm water 60 carry's floatables into the screen system 10 , where the floatables 70 filtered by the screen system 10 are accumulated for later removal. The filtered storm water 80 flows out from the outflow pipe 90 of the system 10 . Storm water flow 100 into the screen system 10 is diminished by the backup of floatables 30 into the system 10 .
Referring to FIGS. 1-2 , storm water flow into screen system diminished by backup 100 of floatables in the system 10 . The incoming storm water 40 encounters the backup of floatables 100 where turbulence 130 in the screen system 10 agitates previously captured floatables 70 which can flow up and backwards 110 toward the front of the screen system 10 . The backflow 120 from the screen system 10 then flows around the sides of the system 10 towards the outflow pipe 90 carrying previously captured floatables 160 out of the baffle box 20 . Storm water outflow 150 from the baffle box's 20 then carry's previously captured floatables out of the system 10 . The screen system 10 becomes compromised 140 by the backup 100 / 250 of floatables in the system 10 .
Referring to FIGS. 1-2 , most of the storm water will not flow through the screen system 10 . Turbulence caused by storm water flowing into the backed up screen system 10 agitates the previously collected floatables 160 causing them to escape from the screen system 10 and flow out of the box 20 .
Thus, the need exists for solutions to the above problems with the prior art.
SUMMARY OF THE INVENTION
A primary objective of the present invention is to provide devices, apparatus, systems and methods for improving the removal efficiency of screen systems in storm water vaults, and the like, by preventing the formation of a backflow current problem within the screen system.
A secondary objective of the present invention is to provide devices, apparatus, systems and methods for improving storm water screen systems to accumulate floating debris, litter and the like, without losing previously captured debris.
A third objective of the present invention is to provide devices, apparatus, systems and methods for improving storm water screen systems by using half pivot panels.
A fourth objective of the present invention is to provide devices, apparatus, systems and methods for improving storm water screen systems by using full pivot panels.
A fifth objective of the present invention is to provide devices, apparatus, systems and methods for improving storm water screen systems by using half pylons.
A sixth objective of the present invention is to provide devices, apparatus, systems and methods for improving storm water screen systems by using full pylons.
A seventh objective of the present invention is to provide devices, apparatus, systems and methods for improving storm water screen systems by using a combination of half pylons and half pivot panels.
A version of the improved screen system for preventing backflow currents during storm water treatments, can include a screen housing for being placed in a storm water treatment environment, the housing having an input end and an output end, and a backflow current preventer at the input end of the screen housing, wherein the backflow current preventer stops debris for passing out of the screen system when incoming storm water is flowing through the screen system.
The backflow preventer can be a pivoting panel at the input end of the screen housing for diverting the incoming storm water downward through the screen system. The pivoting panel can be sloped at an angle to the incoming storm water flowing through the screen system. Sloping the panel can enhance floatables to be directed downward and moving into the body of the screen system. The panel can be solid. The panel can be perforated. The panel can be rigid. Alternatively, the panel can be flexible.
The pivoting panel can be substantially vertically oriented substantially perpendicular to the incoming storm water flowing through the screen system. A hinge can attach a top portion of the panel to the screen system.
A gap or opening can be located adjacent to the inflow on the bottom of the screen system for allowing sediment from incoming storm water to drop beneath the screen system.
The pivoting panel can be a half panel that is pivotally attached to a ceiling of the screen system and having a bottom end substantially half way between a floor and the ceiling of the screen system.
The pivoting panel can be a full size panel that is pivotally attached to a ceiling of the screen system and having a bottom end substantially adjacent to a floor of the screen system.
The backflow current preventer can be a pylon at the input end of the screen housing for diverting the incoming storm water to horizontally split to left and right sides inside of the screen system.
The pylon can have a flat face on a side facing the incoming storm water.
The pylon can have a rounded face on a side facing the incoming storm water.
The pylon can have a triangular shaped face on a side facing the incoming water.
A gap or opening can be located adjacent to the inflow on the bottom of the screen system for allowing sediment from incoming storm water to drop beneath the screen system.
The pylon can be a half size pylon having a bottom end adjacent to a floor of the screen system. The pylon can be a full size pylon that runs between a floor and ceiling of the screen system.
The backflow preventer can include both a pivoting panel at the input end of the screen housing for diverting the incoming storm water downward through the screen system, and a pylon at the input end of the screen housing for diverting the incoming storm water to horizontally split to left and right sides inside of the screen system.
A gap or opening can be located adjacent to the inflow on the bottom of the screen system for allowing sediment from incoming storm water to drop beneath the screen system.
Another version of the storm water screen system with pivotable gate for preventing backflow currents during storm water treatments can include a screen housing for being placed in a storm water treatment environment, the housing having an input end and an output end, and a pivoting panel at the input end of the screen housing for downwardly diverting the incoming storm water downward through the screen system to prevent back flow current which stops debris from passing out of the screen system when incoming storm water is flowing through the screen system.
A hinge can attach a top portion of the panel to the screen system.
A gap can be located in front of the screen system for allowing sediment from incoming storm water to drop beneath the screen system.
Another version of the storm water screen system with pylon diverter for preventing backflow currents during storm water treatments, can include a screen housing for being placed in a storm water treatment environment, the housing having an input end and an output end, and a pylon at the input end of the screen housing for splitting the incoming storm water through the screen system to prevent backflow current which stops debris from passing out of the screen system when the incoming storm water is flowing through the screen system.
The pylon diverter can have a flat face on a side facing the incoming storm water.
The pylon diverter can be a nonflat flat face facing the incoming storm water.
A gap can be located in front of the screen system for allowing sediment from incoming storm water to drop beneath the screen system.
A method for preventing backflow currents in storm water treatment systems, can include the steps of positioning a screen housing in a storm water treatment environment, the housing having an input end and an output end, flowing incoming storm water with debris into the input end of the screen housing, preventing backflow current from occurring in the screen housing, and stopping debris from passing out of the output end of the screen system when the incoming storm water is flowing through the screen system.
The preventing step can include the step of downwardly diverting the incoming storm water entering into the input end of the screen housing. The downwardly diverting step can include the step of providing a pivotable panel for downwardly diverting the incoming storm water entering into the input end of the screen housing.
The method can further include the step of collecting sediment from the incoming storm water through a gap or opening adjacent to the inflow on the bottom of the input end of the screen housing.
The preventing step can include the step of splitting the incoming storm water entering into the input end of the screen housing. The splitting step can include the step of providing a pylon for splitting the incoming storm water entering the screen housing.
The method can include the step of collecting sediment from the incoming storm water through a gap in front of the input end of the screen housing.
The preventing step can include the steps of downwardly diverting the incoming storm water entering into the input end of the screen housing, and splitting the incoming storm water entering into the input end of the screen housing.
The preventing step can include the steps of providing a pivotable panel for downwardly diverting the incoming storm water entering into the input end of the screen housing, and providing a pylon for splitting the incoming storm water entering into the input end of the screen housing.
The method can include the step of collecting sediment from the incoming storm water through a gap in front of the input end of the screen housing.
Further objects and advantages of this invention will be apparent from the following detailed description of the presently preferred embodiments which are illustrated schematically in the accompanying drawings.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a top perspective view of prior art baffle box with storm water and floatables flowing through the screen system.
FIG. 2 is another top perspective view of the prior art baffle box of FIG. 1 with a backed up screen system.
FIG. 3 shows a top perspective view of a baffle box installed with a half pivot panel.
FIG. 4 is a cross-sectional side view of the baffle box with installed half pivot panel along arrows 4 X or FIG. 3 .
FIG. 4A is an enlarged view of the installed half pivot panel of FIG. 4 .
FIG. 5 shows another top perspective view of the baffle box with installed half pivot panel of FIG. 3 in a high flow condition.
FIG. 6 is a cross-sectional side view of the baffle box with installed half pivot panel of FIG. 5 along arrow 6 X in a high flow condition.
FIG. 6A is an enlarged view of the installed half pivot panel of FIG. 6 in high flow condition.
FIG. 7 is a top front perspective view of a baffle box with a backed up screen system and an installed half pivot panel.
FIG. 8 is a cross-sectional side view of the baffle box with backed up screen system and installed half pivot panel of FIG. 7 along arrow 8 X.
FIG. 9 is a top perspective view of baffle box installed with a full pivot panel.
FIG. 10 is a cross-sectional side view of the baffle box with installed full pivot panel of
FIG. 9 along arrow 10 X.
FIG. 10A is an enlarged view of the installed full pivot panel of FIG. 10 .
FIG. 11 is a cross-sectional side view of the baffle box with installed full pivot panel of FIG. 9 in a high flow condition.
FIG. 11A is an enlarged view of the installed full pivot panel of FIG. 11 in a high flow condition.
FIG. 12 is a top perspective view of the baffle box with a full pivot panel installed with the screen system being obstructed by floatables.
FIG. 13 is a cross-sectional side view of the screen system of FIG. 12 along arrow 13 X.
FIG. 14 is a top perspective view of a baffle box with a half pylon installed at the head of the screen system.
FIG. 15 is a top cross-sectional view of the baffle box with half pylon of FIG. 14 along arrow 15 Y.
FIG. 16 is a top perspective view of the baffle box with half pylon installed and the screen system obstructed by previously collected floatables.
FIG. 17 is a top cross-sectional view of the baffle box with installed half pylon of FIG. 16 along arrow 17 Y.
FIG. 18 is a top perspective view of a baffle box with full pylon installed at the head of the screen system.
FIG. 19 is a top cross-sectional view of baffle box installed with a fully pylon of FIG. 18 along arrow 19 Y.
FIG. 20 is a top perspective view of the baffle box with installed full pylon of FIG. 18 with screen system being obstructed by previously collected floatables.
FIG. 21 is a top cross-sectional view of the baffle box with installed full pylon of FIG. 20 along arrow 21 Y.
FIG. 22 is a top perspective of baffle box with half pylon and half pivot panel installed. A low flow condition is shown and the pivot panel rests atop the pylon.
FIG. 23 is a cross-sectional side view of the baffle box with installed pylon and pivot panel of FIG. 22 along arrow 23 X.
FIG. 24 is another cross-sectional side view of FIG. 22 along arrow 23 X shown in a high flow condition. Increased water flow has raised the pivot panel.
FIG. 25 another cross-sectional side sectional view of FIG. 22 along arrow 23 X with the screen system obstructed by previously collected floatables.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Before explaining the disclosed embodiments of the present invention in detail it is to be understood that the invention is not limited in its applications to the details of the particular arrangements shown since the invention is capable of other embodiments. Also, the terminology used herein is for the purpose of description and not of limitation. A list of the components in the figures will now be described.
10 . Prior Art Screen system removes floatables from storm water. 16 . Optional inflow gap. 20 . Deflector baffle box. Prior art. 30 . Floatables washed into baffle box with storm water. 40 . Storm water and floatables flow into baffle box. 50 . Inflow pipe. 60 . Storm water carry's floatables into screen system. 70 . Floatables filtered by screen system and accumulated for later removal. 80 . Filtered storm water flowing out of baffle box. 90 . Outflow pipe. 100 . Storm water flow into screen system diminished by backup of floatables in system. 110 . Storm water flow into system encounters backup of floatables and flows back out of the screen system entrance. Previously captured floatables, agitated by turbulence in the system, are washed out of the screen system. 120 . Backwash from the screen system flows around the system towards the outflow pipe carrying previously captured floatables out of the baffle box. 130 . Turbulence in the screen system agitates previously captured floatables. 140 . Screen system compromised by backup of floatables blocking free flow through the system. 150 . Storm water outflow from baffle box carry's previously captured floatables out of the system. 160 . Previously captured floatables. 170 . Waterline. 180 . Pivoting half panel responds to rate of storm water flow. 190 . Pivoting panel hinge. 200 . Cross beam in screen system secures the half panel hinge. 210 . Bracket attached to side of screen system acts as a down stop for the pivoting half panel. 220 . In a screen system that is not backed up with floatables, rising water level and increasing flow rate cause the pivoting half panel to swing up to accommodate flow. 230 . Screen system with pivoting half panel or full panel installed to prevent back-flow of previously captured floatables from escaping system. 240 . Storm water inflow encounters the half panel locked down by the back pressure inside of the screen system and flows around the screen system out the outflow pipe. 250 . Backup of floatables in screen system. 260 . Turbulence in backed up screen system applies pressure to the back of the half panel preventing previously collected floatables from escaping the screen system. 270 . Some diminished flow through the screen system is possible with a backup of floatables. 280 . Storm water flows out of baffle box containing no previously collected floatables. 290 . Half pivot panel locked down by turbulence in backed screen system. 300 . Storm water flows out of the sides of the screen system bypassing the previously captured floatables. 310 . Pivoting full panel. 320 . In a screen system that is not backed up with floatables, rising water level and increasing flow rate cause the pivoting full panel to swing up to accommodate flow. 330 . Storm water flows around pylon and into screen system. 340 . Storm water flows freely past pylon and through screen system. 350 . Half height pylon. 360 . Part of floor of screen system replaced by solid metal plate to support pylon. 370 . Screen system with half or full pylon installed. 380 . Diminished flow or storm water flowing into obstructed screen system flows out of the sides of the screen system. 390 . Back pressure from the obstructed screen system causes storm water to flow around the screen system. 400 . Full height pylon.
Half Pivot Panel Embodiment
FIG. 3 shows a top perspective view of a baffle box 20 installed with a half pivot panel 180 in a low flow condition. FIG. 4 is a cross-sectional side view of the baffle box with installed half pivot panel 180 along arrows 4 X of FIG. 3 . FIG. 4A is an enlarged view of the installed half pivot panel 180 of FIG. 4 . The embodiment 230 of FIGS. 3-4 uses a screen system with installed pivoting half panel 180 to prevent back-flow of previously captured floatables from escaping the system 10 .
The half panel can have a length between approximately ¼ to approximately ¾ of the distance between the ceiling and floor of the screen system. The panel can have a length of approximately ½ to approximately ⅔ of the length between the ceiling and the floor of the screen system, and preferably be half the distance. The panel can be rigid such as being formed from metal, or fiberglass or plastic. The panel can be flexible and be formed from rubber, and similar materials. The panel can be solid. Alternatively, the panel can be porous with holes.
Referring to FIGS. 3 , 4 and 4 A, a half pivot panel 180 can be attached to a cross beam 200 by a pivoting panel hinge 190 . A bracket 210 attached to a side of the screen system 10 acts as a down stop for the pivoting half panel 180 . In this low flow condition the panel 180 is down against the down stops 210 . The incoming flowing storm water 60 with floatables creates a waterline 170 that allows the half panel to be in the down position. Without incoming storm water, gravity would tend to keep the panel 180 in a generally down position.
The pivoting panel 180 can articulate all the way to a substantially horizontal position so that during high flow events the water flow will not be encumbered by the panel 180 . If the screen system 230 does not become obstructed by debris there will be no chance for a hack flow to develop. However, if the screen system 140 becomes significantly obstructed and the flow is high a backflow can develop. If a backflow begins to develop the pivoting panel 180 will be forced down by the force of the backflow current. When the pivoting panel 180 is forced down it will act as a barrier to prevent already captured floating debris from escaping.
Optionally sometimes working in conjunction with the pivoting panel 180 can be an inflow gap 16 between the inflow pipe 50 and the screen system 230 . The inflow gap 16 allows for sediment coming with the floating debris in the storm water flowing into the vault to drop into a settling chamber beneath the vault. The inflow gap 16 can be directly under the inflow and before the bottom of the screen system begins. Because sediments are heavier than water they are concentrated along the bottom of the inflowing water 40 and within close proximity to the inflow gap. A relatively high percentage of the sediments will fall through the inflow gap 16 and into the lower sediment collection chamber(s). This changes the ratio of sediment to floatables in the screen system so that less sediment is involved with the collected floating debris. And this enables the floating debris to pass water flow more readily, and in doing so reduces the likelihood that a backflow current will develop. The gap can be any size opening that is larger than the hole size of the screens in the screen enclosure.
Once a storm water causing condition such as a rain event is over the collected floating debris will dry out and to fall off of the vertical walls of the screen system 230 .
If the screen system 230 has a screened lid the dried floating debris will fall off of the lid. As the floating debris falls off the screens the openings in the screens become available to handle the water flow from the next storm water type rain event.
FIG. 5 shows another top perspective view of the baffle box 20 with installed half pivot panel 180 of FIG. 3 in a high flow condition. FIG. 6 is a cross-sectional side view of the baffle box 20 with installed half pivot panel 180 of FIG. 5 along arrow 6 X in a high flow condition. FIG. 6A is an enlarged view of the installed half pivot panel of FIG. 6 in high flow condition.
In this high-flow condition the half panel 180 has been lifted by the high-flow waterline 170 to permit free passage through the screen system 10 . In a screen system 10 that is not backed up with floatables, rising water level and increasing flow rate cause the pivoting half panel 180 to swing up along arrow 220 to accommodate flow.
FIG. 7 is a top front perspective view of the baffle box 10 with a backed up screen system 10 and an installed half pivot panel 180 . FIG. 8 is a cross-sectional side view of the baffle box 20 with backed up screen system 10 and installed half pivot panel 180 of FIG. 7 along arrow 8 X.
Referring to FIGS. 7-8 , back pressure from turbulence 260 inside the screen system 10 can cause locking of the half pivot panel 180 against the down stops 210 preventing previously collected floatables from escaping. Inflowing storm water is turned away by the half panel 180 and flows around the screen system 10 to the outflow pipe 90 . Some of the diminished flow 270 through the screen system 10 flows out the sides of the screen system 10 as shown by arrows 300 .
Storm water inflow 40 encounters the half panel 180 locked down by the back pressure inside of the screen system 140 and flows around 240 the screen system 140 out the outflow pipe 90 .
Turbulence 260 in the backed up screen system 140 applies pressure to the back of the half panel 180 preventing previously collected floatables from escaping the screen system 140 . The half pivot panel 180 is locked down 290 by the turbulence 260 in the backed up screen system 140 .
There is some possible diminished flow 270 through the screen system 140 with a backup of floatables 250 . At the outflow pipe 90 , storm water 280 flows out of the baffle box 20 containing no previously collected floatables. As previously described storm water flows out the sides of the screen system 140 along arrows 300 bypassing the previously captured floatables 70 , 250 .
Full Pivot Panel
FIG. 9 is a top perspective view of baffle box 20 installed with a full pivot panel 310 . FIG. 10 is a cross-sectional side, view of the baffle box 20 with installed full pivot panel 310 of FIG. 9 along arrow 10 X. FIG. 10A is an enlarged view of the installed full pivot panel 310 of FIG. 10 .
Similar to the half pivot panel 180 , the full pivot panel is also attached to a cross beam 200 by a hinge 190 . A bracket 210 attached to a side of the screen system 230 acts as a down stop for the pivoting full panel 310 . The full panel can have a length at least as long as the height between the ceiling and the floor of the screen system, and be made of similar materials and be solid or porous similar to the half panel, previously described.
FIG. 11 is a cross-sectional side view of the baffle box with installed full pivot panel of FIG. 9 in a high flow condition. FIG. 11A is an enlarged view of the installed full pivot panel of FIG. 11 in a high flow condition. In a screen system 230 installed with a full panel 310 and that is not backed up with floatables, rising water level 170 and increasing flow rate can cause the pivoting panel 310 to swing up to position 320 to accommodate flow.
FIG. 12 is a top perspective view of the baffle box 20 with a full pivot panel 310 installed with the screen system 140 being obstructed by floatables. FIG. 13 is a cross-sectional side view of the screen system 140 of FIG. 12 along arrow 13 X.
Referring to FIGS. 12-13 , back pressure from turbulence 260 inside the screen system is locking the full pivot panel 310 against the down stops 210 preventing previously collected floatables from escaping. Inflowing storm water 40 is turned away by the full panel 310 and flows around 240 the screen system to the outflow pipe 90 . Diminished flow 270 under the panel 310 and into the screen system flows out of the sides of the screen system.
The larger and longer panels can be used when there are low amounts of floatables coming into the screen system at any time, and the larger and the longer of the panels can prevent captured floatables from escaping out of the screen system. The shorter panels (half panels) can be used in high flow conditions are occurring much more often.
Half Pylon Embodiment
FIG. 14 is a top perspective view of a baffle box 20 with a half pylon 350 installed at the head of the screen system 370 . FIG. 15 is a top cross-sectional view of the baffle box 20 with half pylon 350 of FIG. 14 along arrow 15 Y.
Referring to FIGS. 14-15 , the half pylon 350 can be mounted on solid plate 360 , that replaces part of the floor of the existing screen system, the presence of the pylon 350 discourages back flow out of the screen system 370 which would release previously collected floatables. Water flows freely around 330 the pylon and through 340 the screen system 370 .
The pylons can be desirable over pivoting panels when the user does not want any moving parts. The pylons can have a lower amount of maintenance time and costs over the panels by not having any movable parts.
FIG. 16 is a top perspective view of the baffle box 20 with half pylon 350 installed and the screen system 140 obstructed by previously collected floatables. FIG. 17 is a top cross-sectional view of the baffle box 20 with installed half pylon 350 of FIG. 16 along arrow 17 Y.
The pylon 350 can be rigid, smooth, and shaped to spread the water flow entering the screen system. The height of the pylon 350 can vary depending of site specific criteria and the width of the pylon 350 can be approximately ⅓ the width of the screen system 2 . Floating debris that impacts the pylon 350 is able to easily slip off the pylon 350 and continue into the screen system 140 / 370 . The pylon 350 can have a wedge or triangular front face configuration that faces the incoming water flow. The triangle can range from approximately 30 degrees to over approximately 70 degrees. The sharper the tip and angle of the triangle, the greater the chance of breaking up debris, which will eliminate clogging effects in the system.
The front face of the pylon can also be flat so as not to cause shedding or breaking up of debris. Also the front face of the pylon can be convex rounded, and the like.
Generally, the flow entering a storm water vault is conveyed via a round pipe 50 and the water will enter centrally into the screen system 140 / 370 with significant velocity. This makes for a concentrated central flow in the screen system. The pylon 350 acts to spread the flow wide within the screen system 140 / 370 so that the flow entering the screen system is traveling at the same velocity across the width of the screen system. Because the flow is no longer concentrated in the screen system 2 a backflow is prevented from forming. Without a backflow previously captured debris will not be able to escape the screen system 140 / 370 , and additional debris will continue to be collected in the screen system.
Referring to FIGS. 14-15 , the presence of the pylon 350 discourages back flow of previously collected floatables out of the obstructed screen system. Inflowing storm water 60 is turned away by the pylon 350 and back pressure 390 in the screen system and flows around 390 the screen system 140 / 370 . Diminished flow 380 around the pylon 350 and into the screen system 140 flows out 380 of the sides of the screen system.
Optionally, working in conjunction with the pylon 350 can be an inflow gap 16 or opening in the bottom of the screen system adjacent to the inflow, similar to that shown in the previous embodiment. As water flows into the storm water vault both sediments and floating debris can drop through the gap 16 into a sediment settling collection chamber in the bottom of the vault. The inflow gap 16 can be directly under the inflow and before the bottom of the screen system 140 / 370 begins. Because sediments are heavier than water they are concentrated along the bottom of the inflowing water and within close proximity to the inflow gap. A relatively high percentage of the sediments can fall through the inflow gap 16 and into the lower sediment collection chamber(s). This changes the ratio of sediment to floatables in the screen system so that less sediment is involved with the collected floating debris. This enables the floating debris to pass water flow more readily, and in doing so reduces the likelihood that a backflow current condition problem will develop in the screen system.
Once a storm water condition such as one caused by a rain event is over the collected floating debris will dry out and to fall off of the vertical walls of the screen system. If the screen system has a screened lid the dried floating debris will fall off of the lid. As the floating debris falls off the screens the openings in the screens become available to handle the water flow from the next storm water rain type event.
Full Pylon Embodiment
FIG. 18 is a top perspective view of a baffle box 20 with full height pylon 400 installed at the head of the screen system 370 . FIG. 19 is a top cross-sectional view of baffle box 20 installed with the full pylon of FIG. 18 along arrow 19 Y.
Referring to FIGS. 18-19 , the full size pylon 400 can also be mounted on a plate 260 , such as a metal plate that replaces part of the floor of the screen system. The full size pylon can have a height rising from the floor of the screen system up to the ceiling of the screen system. The presence of the full height pylon 400 discourages back flow out of the screen system which would release previously collected floatables. Water flows freely around 330 the pylon 400 and through screen system 370 .
FIG. 20 is a top perspective view of the baffle box 20 with installed full pylon 400 of FIG. 18 with screen system 370 being obstructed by previously collected floatables. FIG. 21 is a top cross-sectional view of the baffle box 20 with installed full pylon 400 of FIG. 20 along arrow 21 Y.
Referring to FIGS. 20-21 , the presence of the full pylon discourages back flow of previously collected floatables out of the obstructed screen system. Inflowing storm water is turned away by the pylon 400 and back pressure 390 in the screen system and flows around the screen system. Diminished flow 380 around the pylon and into the screen system flows out of the sides of the screen system. The pylon can have some desirability over the pivoting panels since there are no moving parts, which can decrease maintenance labor and material costs.
Pivoting Panel and Pylon Combination Embodiment
FIG. 22 is a top perspective of baffle box 20 with half pylon 350 and half pivot panel 180 installed in the screen system 230 / 370 . FIG. 23 is a cross-sectional side view of the baffle box with installed pylon and pivot panel of FIG. 22 along arrow 23 X.
Referring to FIGS. 22-23 , the pylon 350 will not be tall and the pivoting panel 180 will not reach all the way to the bottom of the screen system. The pylon 350 will act to spread the flows wide and the pivoting panel 180 will act as a barrier to prevent floating debris from escaping if a backflow current tries to form. Because the pivoting panel 180 does not extend to the bottom of the screen system it cannot be encumbered by captured debris. In addition, if the flow is small then floating debris can enter the screen system without having to push past the pivoting panel. By combining the best attributes of the pivoting panel 180 and the pylon 350 a backflow current condition in the screen system can be avoided enabling floating debris to be continuously collected without the loss of previously captured debris.
Referring to FIGS. 22-23 , the half pylon 350 - and half pivot panel 180 can be installed similar to those in the previous embodiment. A low flow condition is shown by waterline 170 and the pivot panel 180 rests atop the pylon 350 . Water flows freely around 330 pylon 350 and under the pivot panel 180 and through the screen system 230 / 370 .
FIG. 24 is another cross-sectional side view of FIG. 22 along arrow 23 X shown in a high flow condition. Increased water flow has raised the pivot panel. FIG. 25 another cross-sectional side sectional view of FIG. 22 along arrow 23 × with the screen system 230 / 370 obstructed by previously collected floatables. Water flows freely around 330 the pylon 350 and under the raised pivot panel 180 and through the screen system.
Back pressure 390 exerted by the obstruction locks the pivot panel 180 down 290 . The presence of the pylon 350 and pivot panel 180 discourages back flow of previously collected floatables out of the obstructed screen system. Inflowing storm, water is turned away by the pylon 350 /pivot panel 180 and flows around 380 / 390 the screen system. Diminished flow 380 around the pylon 350 and under the pivot panel 180 flows into the screen system out 380 of the sides of the screen system 230 / 370 .
Optionally, the effectiveness of the combined pivoting panel 180 and pylon 350 can by enhanced by using an inflow gap 16 or opening at the lead in to the screen system as described in the previous embodiments. As water flows into the storm water vault both sediments and floating debris drop through the gap 16 into a settling chamber in the bottom of the vault. The inflow gap 16 can be directly under the inflow and before the bottom of the screen system 230 / 370 begins. Because sediments are heavier than water they are concentrated along the bottom of the inflowing water and within close proximity to the inflow gap 16 . A relatively high percentage of the sediments will fall through the inflow gap 16 and into the lower sediment collection chamber(s). This changes the ratio of sediment to floatables in the screen system 2 so that less sediment is involved with the collected floating debris. And this enables the floating debris to pass water flow more readily, and in doing so reduces the likelihood that a backflow current condition will develop.
The gap can also act as a drain when the screen system is fully impacted (totally blocked off and will allow for floatables to be stored in a dry state between rainfalls.
Alternatively, the pylon can be attached to the roof of the screen system
Other embodiments can be used such as attaching a pivoting panel to the top of a pylon, so that the panel does not have to be attached to the screen system.
Once the storm water causing condition such as the rain event is over the collected floating debris will dry out and to fall off of the vertical walls of the screen system. If the screen system 2 has a screened lid the dried floating debris will fall off of the lid. As the floating debris falls off the screens the openings in the screens become available to handle the water flow from the next storm water type rain event.
While the invention has been described, disclosed, illustrated and shown in various terms of certain embodiments or modifications which it has presumed in practice, the scope of the invention is not intended to be, nor should it be deemed to be, limited thereby and such other modifications or embodiments as may be suggested by the teachings herein are particularly reserved especially as they fall within the breadth and scope of the claims here appended. | Devices, apparatus, systems and methods for preventing backflow current problems which often have caused debris and litter to pass out of screen type baskets used in storm water treatment systems. A half size or full size pivoting panel at the input end of a basket screen system placed in a storm water treatment chamber can downwardly divert incoming storm water so as to prevent back flow currents from being formed. The pivoting panel can work well during high flow conditions. A half size or full size pylon located in the input end of the basket screen can split and divert incoming storm water to also prevent back flow currents from also being formed. The pylon can work well during low flow conditions. Also, both the half pivoting panel and the half pylon can both be used at the input end of the screen basket. Still furthermore a gap in the floor before the input end of the screen basket can allow for sediment coming to pass down and collect beneath the screen basket. | 4 |
TECHNICAL FIELD
[0001] Present invention relates to thermal insulation materials made of hollow oxide particles, the preparation thereof and their use as thermal insulation materials.
BACKGROUND/PRIOR ART
[0002] The demand to improve energy efficiency of buildings is increasing as the energy use in the building sector accounts for a significant part of the world's total energy use and greenhouse gas emissions. In this respect the thermal insulation of buildings plays an important role, where one major objective is to develop new and robust insulation materials and solutions with as low thermal conductivity values as possible. Applying traditional thermal insulation materials requires ever increasing thicker building envelopes. This is not desirable for several reasons, e.g. space issues with respect to economy and floor area, transport volumes, architectural restrictions and other limitations, material usage and existing building techniques.
[0003] State-of-the-art thermal insulation materials and solutions like vacuum insulation panels (VIP) [2-3] and aerogels [4] may represent the best thermal insulation today with respect to very low thermal conductivity values. However, both VIPs and aerogels have their drawbacks. The VIP solution, which attains a considerably lower thermal conductivity than the aerogels, does not represent a robust solution as air and moisture over time will penetrate the VIP envelope and thus increase the thermal conductivity due to loss of vacuum. Adaption and cutting of VIPs at the building site cannot be performed without loss of vacuum and thermal resistance, and any perforation of the VIP envelope increases the thermal conductivity from the pristine non-aged value of typical 4 mW/(mK) to about 20 mW/(mK). Furthermore, both VIPs and aerogels are very costly solutions compared to traditional thermal insulation. Nevertheless, in areas with a high living area market value per square meter, a reduced wall thickness (e.g. by use of VIPs) may involve large area savings and thus a higher value of the real estate.
[0004] Other high performance thermal insulation materials i.e. advanced insulation materials (AIM) include vacuum insulation materials (VIM), gas insulation materials (GIM), nano insulation materials (NIM), dynamic insulation materials (DIM) and NanoCon have been presented earlier [2, 5-7].
[0005] The total overall thermal conductivity λ tot , i.e. the thickness of a material divided by its thermal resistance, is in principle made up from several contributions:
[0000] λ tot =λ solid +λ gas +λ rad +λ conv +λ coupling +λ leak (1)
[0000] where λ tot =total overall thermal conductivity, λ solid =solid state thermal conductivity, λ gas =gas thermal conductivity, λ rad =radiation thermal conductivity, λ conv =convection thermal conductivity, λ coupling =thermal conductivity term accounting for second order effects between the various thermal conductivities in Eq.1 and λ leak =leakage thermal conductivity. Each of these thermal contributions must be minimized in order to reach as low thermal conductivity as possible. The leakage thermal conductivity λ leak representing an air and moisture leakage driven by a pressure difference, is normally not taken into consideration since insulation materials and solutions are supposed to be without any holes that would enable such a thermal leakage transport. The coupling term λ coupling can be included to account for second order effects between the various thermal conductivities in Eq.1, and may be quite complex. Theoretical approaches to thermal performance of vacuum insulation panels (VIP) usually assume this coupling effect to be negligible [8]. Generally, another coupling term might also be included in Eq.1, i.e. the interaction between the gas molecules and the solid state pore walls. However, as we will see later this last coupling term is included through a factor in the expression for the gas conductivity as given in Eq.2 for the Knudsen effect. The solid state thermal conductivity λ solid is related to thermal transport between atoms by lattice vibrations, i.e. through chemical bonds between atoms. The gas thermal conductivity λ gas arises from gas molecules colliding with each other and thus transferring thermal energy from one molecule to the other. The radiation thermal conductivity λ rad is connected to the emittance of electromagnetic radiation in the infrared (IR) wavelength region from a material surface. The convection thermal conductivity λ conv is due to thermal mass transport or movement of air and moisture. All these thermal conductivity contributions are driven by or dependent upon the temperature and temperature difference.
[0006] A vacuum insulation material (VIM) is basically a homogeneous material with a closed small pore structure filled with vacuum with an overall thermal conductivity of less than 4 mW/(mK) in pristine condition. The VIM can be cut and adapted at the building site with no loss of low thermal conductivity. Perforating the VIM with a nail or similar would only result in a local heat bridge, i.e. no loss of low thermal conductivity. A gas insulation material (GIM) is basically a homogeneous material with a closed small pore structure filled with a low-conductance gas, e.g. Ar, Kr or Xe, with an overall thermal conductivity of less than 4 mW/(mK) in the pristine condition. That is, a GIM is basically the same as a VIM, except that the vacuum inside the closed pore structure is substituted with a low-conductance gas. For further details it is referred to Jelle et al. [6].
[0007] The development from VIPs to nano insulation materials (NIM) is depicted in FIG. 1 . In the NIM the pore size within the material is decreased below a certain level, i.e. 40 nm or below for air, in order to achieve an overall thermal conductivity of less than 4 mW/(mK) in the pristine condition. That is, a NIM is basically a homogeneous material with a closed or open small nano pore structure with an overall thermal conductivity of less than 4 mW/(mK) in the pristine condition. The low gas thermal conductivity in NIMs is caused by the Knudsen effect where the mean free path of the gas molecules is larger than the pore diameter. That is, a gas molecule located inside a pore will hit the pore wall and not another gas molecule. The resulting gas thermal conductivity λ gas versus pore diameter and pressure for air is depicted in FIG. 1 based on the following simplified expression taking into account the Knudsen effect [2,6]:
[0000]
λ
gas
=
λ
gas
,
0
1
+
2
β
Kn
=
λ
gas
,
0
1
+
2
β
k
B
T
π
d
2
p
δ
,
Kn
=
σ
mean
δ
=
k
B
T
2
π
d
2
p
δ
(
2
)
[0000] where λ gas =gas thermal conductivity in the pores (W/(mK)), λ gas, 0 =gas thermal conductivity in the pores at STP (standard temperature and pressure) (W/(mK)), β=coefficient characterizing the molecule-wall collision energy transfer efficiency (between 1.5-2.0), k B =Boltzmann's constant≈1.38·10 −23 J/K, T=temperature (K), d=gas molecule collision diameter (m), p=gas pressure in pores (Pa), δ=characteristic pore diameter (m) and σ mean =mean free path of gas molecules (m). The radiation and solid state lattice conductivity in the NIMs has to be kept as low as possible in order to obtain the lowest possible overall thermal conductivity. Applying the Stefan-Boltzmann relationship it may be shown that the radiation thermal conductivity decreases linearly with decreasing pore diameter, where the emissivity of the inner pore walls determine the slope of the decrease, according to the following relationship [6]:
[0000]
λ
rad
=
π
2
k
B
4
δ
60
ℏ
3
c
2
[
2
ɛ
-
1
]
(
T
i
4
-
T
e
4
)
(
T
i
-
T
e
)
(
3
)
[0000] where λ rad =radiation thermal conductivity in the pores (W/(mK)), σ=π 2 k B 4 /(60, 3 c 2 )=Stefan-Boltzmann's constant≈5.67·10 −8 W/(m 2 K 4 ), k B =Boltzmann's constant≈1.38·10 −23 J/K, =h/(2π)≈1.05·10 −34 Js=reduced Planck's constant (h=Planck's constant), c=velocity of light≈3.00·10 8 m/s, δ=pore diameter (m), ε=emissivity of inner pore walls (assumed all identical), T i =interior (indoor) temperature (K) and T e =exterior (outdoor) temperature (K). That is, the smaller the pores, and the lower the emissivity, the lower the radiation thermal conductivity will be FIG. 2 .
[0008] However, various works [9-11] describe a large increase in the thermal radiation as the pore diameter decreases below the wavelength of the thermal (infrared) radiation (e.g. 10 μm), where tunneling of evanescent waves may play an important role. Note that in FIG. 2 the radiation thermal conductivity is only plotted down to a pore diameter of 0.1 mm (100 μm), which is about 10 times larger than the mean infrared wavelength at room temperature (10 μm). The work by Mulet et al. [9] and Joulain et al. [10] indicate that the large thermal radiation is only centered around a specific wavelength (or a few). That is, this might suggest that the total thermal radiation integrated over all wavelengths is not that large. The work by Jelle et al. [6] elaborates more on these thermal radiation issues. These topics are currently being addressed in on-going research activities.
[0009] A dynamic insulation material (DIM) is a material where the thermal conductivity can be controlled within a desirable range. The thermal conductivity control may be achieved by being able to change in a controlled manner (a) the inner pore gas content or concentration including the mean free path of the gas molecules and the gas-surface interaction, (b) the emissivity of the inner surfaces of the pores and (c) the solid state thermal conductivity of the lattice. Two models exist for describing solid state thermal conductivity. That is, the phonon thermal conductivity, i.e. atom lattice vibrations, and the free electron thermal conductivity. One might ask if it could be possible to dynamically change the thermal conductivity from very low to very high, i.e. making a DIM? Furthermore, could other fields of science and technology inspire and give ideas about how to be able to make DIMs, e.g. from the fields of electrochromic materials, quantum mechanics, electrical superconductivity or others? The thermal insulation regulating abilities of DIMs give these conceptual materials a great potential. It is referred to Jelle et al. [6] for further details and elaborations concerning DIMs. With decreasing thermal conductivities of insulation materials, new solutions should also be sought for the load-bearing elements of the building envelope. Using concrete as an example, one might envision mixing NIMs into the concrete, thereby decreasing the thermal conductivity of the construction material substantially, while maintaining most or a major part of the mechanical strength and load-bearing capabilities of concrete. Hence, a new material is introduced on a conceptual basis (Jelle et al. [7]): NanoCon is basically a homogeneous material with a closed or open small nano pore structure with an overall thermal conductivity of less than 4 mW/(mK) (or another low value to be determined) and exhibits the crucial construction properties that are as good as or better than concrete. In the above definition of NanoCon, a homogeneous material is stated, although the first attempts to reach such a material might be tried by piecing or mixing several different materials together, i.e. with a final material product which on a nanoscale is not homogeneous. For example, joining NIM and carbon nanotubes in one single material might enable a very low thermal conductivity due to the NIM part and a very large tensile strength due to the carbon nanotube part. In this respect it should be noted that the extremely large tensile strength of carbon nanotubes (63 000 MPa measured and 300 000 MPa theoretical limit) surpasses that of steel rebars (500 MPa) by more than two orders. As a comparison, concrete itself (without rebars) has a tensile strength of 3 MPa and a compressive strength of 30 MPa.
[0010] The current materials that most closely resemble these ideal nano insulation materials are silica-based aerogels, which are commercially available as nanoporous materials with an open pore structure. Their thermal conductivity in air is typically around 13 mW/(mK) due to the Knudsen effect. They are used as core material in VIPs (4 mW/(mK)), contained in insulating blankets (14 mW/(mK)), and as loose, hydrophobic granules for spraying into building crevices (17 mW/(mK)). A very interesting aspect with aerogels is that they can be produced as either opaque, translucent or transparent materials, thus enabling a wide range of possible building applications. Aerogels have relatively high compression strength, but are very fragile due to their very low tensile strength, and are easily broken down by abrasion processes. The aim is to develop new thermal insulation materials with even better properties than aerogels. The main target is lowered thermal conductivity, with improved mechanical properties. In the first attempts, the aim is to be able to control the nanoscale structure of the material. Silica is chosen as a model material, since various silica precursors are available and their chemistry is quite well-known. At a later stage, similar methods may be developed for other materials, e.g. titania and alumina.
[0011] CN101585954A describes a composite material consisting of silicon dioxide hollow spheres and polymers suitable as insulating material comprising a polymer substrate and submicron mono-disperse silicon dioxide hollow spheres without agglomerations uniformly distributed in the substrate, where the polymer substrate is a substrate of epoxy, polyurethane or polyethylene glycol terephthalate. The hollow inner diameter of the submicron silicon dioxide hollow sphere is 100-172 nm; the thickness of outer wall is 50-100 nm; the submicron silicon dioxide hollow sphere is 1-35 wt. % of polymer substrate in terms of weight.
[0012] Short summary of the invention
[0013] The invention relates to porous insulation materials made of hollow oxide particles. The hollow particles have a typical inner diameter of 10-1000 nm and a dense or porous shell/wall with a typical thickness of less than 50 nm. The shell/wall may be a single phase material or a composite material. Preferably the oxide particles are metal oxide particles or hollow semi-metal oxide particles. In one embodiment the hollow oxide particles are made of at least one oxide selected from the group consisting of silica, titania, alumina, zinc oxide, iron oxide and manganese oxide. The hollow nanoparticles may be spherical, cubic, elliptical, or tube-like, and are preferably hydrophobic. The overall thermal conductivity of the porous nano insulation materials is less than that of normal air, e.g., 0.026 W/(mK). To prepare the hollow nanoparticles, several synthetic approaches can be used, e.g., template-assistant methods, where the template can be soft or hard particles or molecular aggregations with defined geometry.
[0014] The particles can also be prepared by different methods; for example by membrane foaming or gas release. Hydrolysis and condensation of silane precursors may be used to form the solid network.
FIGURES
[0015] FIG. 1 The development from VIPs to NIMs (left) and the effect of pore diameter and pressure on the gas thermal conductivity (Eq.2) for air (right) [6].
[0016] FIG. 2 . The radiation thermal conductivity versus pore diameter for various emissivities of the inner pore walls. From Eq.3 [6].
[0017] FIG. 3 . Preparation of gas capsules by membrane emulsification. Left: Aim of experiment. Right: Micron-sized capsules obtained by Yang et al. [12].
[0018] FIG. 4 . Schematic diagram showing the formation mechanism of hollow silica spheres [15].
[0019] FIG. 5 . SEM image (BSE) showing an overview of the nanosphere sample, where the scale bar is 2 μm.
[0020] FIG. 6 . SEM image (BSE) showing an unetched sphere (left), as well as the same sphere after a little etching (middle) and after more extensive etching (right). The scale bar is 300 nm in all images.
DETAILED DESCRIPTION OF THE INVENTION
[0021] Three different methods for producing nanoporous hydrophobic materials have been investigated, i.e. membrane foaming, gas release and templating. In all cases, hydrolysis and condensation of silane precursors may be used to form the solid network. This is the same reaction that is used for production of aerogels and may be depicted as:
[0000] Hydrolysis: R′-M-OR+H—OH→R′-M-OH+ROH (4)
[0000] Condensation: R′-M-OH+HO—Si—R′→R′-M-O—Si—R′+H 2 O (5)
[0000] R′-M-OR+HO—Si—R′→R′-M-O—Si—R′+ROH (6)
[0022] Membrane Foaming
[0023] In membrane foaming, the idea is to produce foams with nanoscale bubbles, followed by condensation and hydrolysis within the bubble walls to obtain a silica nanofoam. In the process, gas is pressed through a membrane to obtain bubbles with controlled size as depicted in FIG. 3 . Hydrolysis and condensation of precursors at the bubble-liquid interface should result in formation of gas capsules. This method was previously used to obtain nitrogen-containing capsules with titania-polypyrrole composite shells. Their diameter was in the range 1-5 μm as shown in FIG. 3 . Initial experiments indicated that preparation of silica nanofoams might be difficult to accomplish. This was supported by theoretical considerations. The gas pressure must be very accurately adjusted; if the pressure is too low, no bubbles will be formed and if it is too high, a continuous gas stream will result. The size of the bubbles may be decreased by decreasing the pore size of the membrane and adjusting its surface properties to obtain a high contact angle with the solvent, i.e. the solvent should be repelled from its surface. Furthermore, the solvent density should be rather high and its surface tension low. It should in principle be possible to design a reaction system that fulfills these requirements, so that production of nanosized bubbles is viable.
[0024] For the production of a solid nanofoam, the liquid foam must be stable long enough for the reactions in Eqs.4-6 to proceed. Furthermore, if the foam is to be of interest as an insulator, its walls must be thin. Otherwise, the solid contribution to the overall thermal conductivity will be too high. Wall thicknesses of about 20 nm may be achieved if surfactant bilayers are used to stabilize the walls and the applied solvent has low viscosity and is rapidly drained from the wall interior. It is possible to achieve this in water-based systems. However, the reactions in Eqs.4-6 are generally performed in alcohol solutions like ethanol or isopropanol. No surfactant was found that could stabilize nanofoams long enough, thus this line of work was so far abandoned.
Gas Release
[0025] The gas release method would require simultaneous formation of nanosized gas bubbles throughout the reaction system, followed by hydrolysis and condensation (Eqs.4-6) to form a solid at the bubble perimeter. Bubble formation could be achieved by either evaporation or decomposition of a component in the system. This method is similar to the process described by Grader et al. [13], where crystals of AlCl 3 (Pr i 2 O) were heated to produce foams with closed cell structures. In this case, the crystals themselves decomposed. Upon further heating, the remaining solid dissolved in the generated solvent. Then a polymerization reaction occurred at the temperature of solvent evaporation. The solvent bubbles were trapped within the polymerizing gel, forming stable foam with pore sizes 50-300 μm after completion of the reaction. The gas release process entails several challenges. To obtain nanosized bubbles with a sufficiently narrow size distribution, the temperature must be the same throughout the liquid phase. In ordinary reaction conditions, this would be difficult to achieve. Further, the reaction to form the solid shell must proceed very rapidly if the shell is to be formed before the bubbles grow too large. This would require very reactive chemicals, and their application would require strict control of humidity both in the working environment and in the solvents used.
[0026] Templatinq
[0027] In the templating process, a nanoscale structure in the form of a nanoemulsion or polymer gel is prepared, followed by hydrolysis and condensation by Eqs.4-6 to form a solid. This procedure is used for preparing e.g. catalysts and membrane materials. The approach is to prepare hollow silica nanospheres, followed by condensation and sintering to form macroscale particles or objects. For thermal insulation materials, small pore size is preferred, combined with a small wall thickness. Assuming a pore diameter of 100 nm and a wall thickness of 15 nm, the solid volume fraction of the particle would be 54%. With cubic close packing (ccp) of monosized spheres, the solid fraction of a “nanosphere compact” would be 41%. In practice, the sphere packing will always be less efficient than ccp, thus lower solid fractions are envisaged—as is also desired. Several methods for nanosphere production are given in the literature. The current work is based on the work reported by Du et al. [14], who used the method for preparing antireflection coatings. The method is described in more detail by Wan and Yu [15], and their schematic depiction of the synthesis process is shown in FIG. 4 .
[0028] Synthesis starts with dissolving the polyelectrolyte polyacrylic acid (PAA) in ammonia, followed by addition of ethanol to form an emulsion. The droplet size in the emulsion increases with increasing concentration of polyelectrolyte in the solution. The next step is gradual addition of tetraethoxysilane (TEOS), which reacts with water at the droplet surface and forms a solid silica shell. When the sample is washed with water, the polyelectrolyte diffuses through the shell, and after drying, hollow silica nanospheres are obtained.
[0029] Experimental Details of Templating Process
[0030] An initial templating experiment was conducted. First, 0.27 ml of PAA (polyacrylic acid, MW˜5 000, 50% aqueous solution, Polysciences) was dissolved in 4.5 ml 25% NH 4 OH solution (Merck). An emulsion was formed by adding 90 ml of absolute ethanol (Kemetyl) was added during magnetic stirring at a rate of 760 rpm. TEOS (tetraethoxysilane, purum 98.0%), Fluka) was added in five 0.45 ml portions, with at least one hour between additions. The total time of addition was 22 h. The sample was diluted with water to twice the volume and centrifuged at 10 000 rpm for 10 min. The supernatant was removed and the particles were redispersed in water. This cleaning procedure was performed four times. The particle size of the nanospheres in water was measured using a Malvern Zetasizer Nano ZS. The particles were dried and investigated by scanning electron microscopy (SEM), using backscattered electrons (BSE) in a Helios Nanolab” instrument. To further determine whether the spheres were hollow, they were subjected to focused ion beam (FIB) cutting.
[0031] Initial Nanosphere Manufacturing Results
[0032] The produced spheres had a reasonably narrow size distribution, with an average particle size of 190 nm measured by the Malvern Zetasizer. SEM images showed that most particles had diameters between 90 and 400 nm, with most around 200 nm ( FIG. 5 ), which is well in agreement with the size measured in water. In FIG. 5 the spheres show up as circles with dark centers and light edges. This is due to the atomic contrast in BSE images. SiO 2 is shown lighter than void areas. If the particles were dense SiO 2 spheres, they would also have light centers. Thus, this image is the first indication that most of the spheres are indeed hollow. Images of separate particles before and after FIB etching are shown in FIG. 6 . For convenience, relatively large spheres were chosen for the FIB experiments. It is clearly seen that the ion beam removes material from the sphere surface, showing an empty interior. Eventually, the sphere is slightly deformed. If the walls of the sphere are thin, the sphere collapses after etching. The rectangular hole in front of the particle in FIG. 6 (middle and right photos) is a result of ion beam etching of the sample holder.
[0033] The thermal insulation material according to the invention comprises hollow particles. The inner diameter size of the hollow particles will typically be in the range 10-1000 nm, 20-400 nm, 20-300 nm, 20-200 nm or 20-100 nm. The dense or porous shell/wall will have a typical thickness of less than 50 nm. The aim is to produce hollow particles with as small wall thicknesses as possible, but avoid collapsing of the particles. For use as thermal insulation the overall thermal conductivity of the porous nano insulation materials should be less than that of normal air, e.g., 0.026 W/(mK), preferably less than 4 mW/(mK). The particles are filled with gas, they are preferably filled with air.
[0034] In one embodiment of the invention, the shell of the hollow particles consists essentially of inorganic oxide material. In other embodiments the shell consists essentially of a metal oxide or a semi-metal oxide. The shell may be a single phase material or a composite consisting of silica, titania, alumina, zinc oxide, iron oxide, manganese oxide, etc. Any type of oxide that can be prepared from soluble alkoxy compounds can be used. The hollow particles may be spherical, cubic, elliptical, or tube-like.
[0035] The hollow oxide particles used for thermal insulation can be used without any further treatment. In one embodiment of the invention hollow spherical particles of silica are prepared and used as heat insulation material.
[0036] In order to make the nanospheres stick together to form a macroscale material with low solid content different methods should be further investigated. In one embodiment the particles are preferably made hydrophobic, by a hydrophobic surface treatment.
REFERENCES
[0037] [1] McKinsey, “Pathways to a low-carbon economy. Version 2 of the global greenhouse gas abatement cost curve”, McKinsey & Company, 2009.
[0038] [2] R. Baetens, B. P. Jelle, J. V. Thue, M. J. Tenpierik, S. Grynning, S. Uvsløkk and A. Gustaysen, “Vacuum insulation panels for building applications: A review and beyond”, Energy and Buildings, 42, 147-172, 2010.
[0039] [3] M. J. Tenpierik, “Vacuum insulation panels applied in building constructions (VIP ABC)”, Ph.D. Thesis, Delft University of Technology (Delft, The Netherlands), 2009.
[0040] [4] R. Baetens, B. P. Jelle and A. Gustaysen, “Aerogel insulation for building applications: A state-of-the-art review”, Energy and Buildings, 43, 761-769, 2011.
[0041] [5] B. P. Jelle, A. Gustaysen and R. Baetens, “Beyond vacuum insulation panels—How may it be achieved?”, in Proceedings of the 9 th International Vacuum Insulation Symposium ( IVIS 2009), London, England, 17-18 Sep. 2009.
[0042] [6] B. P. Jelle, A. Gustaysen and R. Baetens, “The path to the high performance thermal building insulation materials and solutions of tomorrow”, Journal of Building Physics, 34, 99-123, 2010.
[0043] [7] B. P. Jelle, A. Gustaysen and R. Baetens, “The high performance thermal building insulation materials and solutions of tomorrow”, Proceedings of the Thermal Performance of the Exterior Envelopes of Whole Buildings XI International Conference, Clearwater Beach, Fla., U.S.A., 5-9 Dec. 2010.
[0044] [8] U. Heinemann, “Influence of water on the total heat transfer in ‘evacuated’ insulations”, International Journal of Thermophysics, 29, 735-749, 2008.
[0045] [9] J.-P. Mulet, K. Joulain, R. Carminati and J.-J. Greffet, “Enhanced radiative heat transfer at nanometric distances”, Microscale Thermophysical Engineering, 6, 209-222, 2002.
[0046] [10] K. Joulain, J.-P. Mulet, F. Marquier, R. Carminati and J.-J. Greffet, “Surface electromagnetic waves thermally excited: Radiative heat transfer, coherence properties and Casimir forces revisited in the near field”, Surface Science Reports, 57, 59-112, 2005.
[0047] [11] Z. M. Zhang, “Nano/microscale heat transfer”, McGraw-Hill, 2007.
[0048] [12] J. Yang, L. Sivakanesar and C. R. Simon, “Membrane emulsification for preparation of gas capsules”, Personal communication, 2007.
[0049] [13] G. S. Grader, Y. de Hazan and G. E. Shter, “Ultra light ceramic foams”, Sol - gel Synthesis and Processing, 95, 161-172,1998.
[0050] [14] Y. Du, L. E. Luna, W. S. Tan, M. F. Rubner and R. E. Cohen, “Hollow silica nanoparticles in UV-visible antireflection coatings for poly(methyl methacrylate) substrates”, ACS Nano, 4, 4308-4316, 2010.
[0051] [15] Y. Wan and S.-H. Yu, “Polyelectrolyte controlled large-scale synthesis of hollow silica spheres with tunable sizes and wall thicknesses”, Journal of Physical Chemistry C, 112, 3641-3647, 2008. | The present invention relates to thermal insulation materials made of hollow oxide particles. Use of hollow oxide particles having an overall thermal conductivity of less than 0.026 W/(mK) is for example suitable for the building sector or other areas where thermal insulation is required. | 4 |
BACKGROUND OF THE INVENTION
[0001] This invention is directed toward a portable lighting system and particularly to a lighting system that is retractable.
[0002] Lighting systems are known in the art and those that are used for traffic situations such as accidents, road side service, and construction typically are large, complex, expensive, and difficult to transport. Because of this, rarely is a lighting system available for a first responder to an accident or service call. As a result, this creates safety issues for the first responder as well as leads to potential traffic congestion. Accordingly, there is a need in the art for a lighting system that addresses these needs.
[0003] Therefore, an objective of the present invention is to provide a lighting system that is portable and easy to transport.
[0004] Another objective of the present invention is to provide a lighting system that is retractable.
[0005] A still further objective of the present invention is to provide a lighting system that is easy to set up.
[0006] These and other objectives will be apparent to one of ordinary skill in the art based upon the following written description, drawings, and claims.
SUMMARY OF THE INVENTION
[0007] A portable lighting system having an elongated support member with retractable legs at one end and a control box at the opposite end. Pivotally connected to the control box is at least one light assembly. A first and a second mounting member are slidably mounted to the support member. The first mounting member is connected to the legs such that as the mounting member moves along the support member the legs move from a retractable position to a support position and back. The second mounting member is connected to the light assembly(s) such that as the second mounting member moves along the support member, the light assembly moves from a retracted position to an extended position and back.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a front view of a lighting system;
[0009] FIG. 2 is a front view of a lighting system;
[0010] FIG. 3 is a perspective view of a mounting member; and
[0011] FIG. 4 is a perspective view of a mounting member.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0012] Referring to the Figures, a portable light system 10 has a plurality of leg members 12 that are pivotally connected to a support member 14 . Preferably, the support member 14 is comprised of three sections that fit within one another. In its original retracted position the length of the support member is 48 inches and in its fully expanded position will be 60 inches. Slidably mounted to the support member 14 is a first mounting member 16 . Mounting member 16 has a plurality of flanges 18 that extend outwardly with each flange 18 having an opening 20 . Mounting member 16 also has a pull pin mount 22 and opening 24 that aligns with openings 26 on the support member 14 to receive a pull pin 28 .
[0013] Pivotally connected to the flanges 18 at one end are a plurality of guide bars 30 . The guide bars 30 are pivotally connected to the leg members 12 at the opposite end.
[0014] Attached to the opposite end of the support member 14 is a control box 32 that has a switch 34 electrically connected to a circuit board 36 which is connected to a power source such as a battery 38 . Slidably mounted between the control box 32 and the first mounting member 16 is a second mounting member 40 . The second mounting member 40 has a pair of bushing braces 42 and a pull pin mount 44 . The pull pin mount 44 is aligned with an opening 46 in mounting member 40 that aligns with openings 26 on the support bar 14 to receive a pull pin 28 . Also attached to mounting member 40 is a handle 48 .
[0015] Pivotally connected to the control box 32 is a plurality of light assemblies 50 . The light assemblies 50 , which are electrically connected to the circuit board 36 , have an elongated partial housing 52 and a plurality of lights 54 dispersed along housing 52 . Pivotally connected to the light assemblies 50 , are a plurality of spreader bars 56 which are pivotally connected to the bushing braces 42 at an opposite end.
[0016] When in a retracted position, as shown in FIG. 2 , first mounting member 16 and second mounting member 40 are positioned close to one another along support member 14 . As such leg members 12 and light assemblies 50 are retracted to a position generally parallel with and between the ends of the support member 14 .
[0017] To move to a working upright position, pull pin 18 is removed from openings 24 and 26 and mounting member 16 is slid along support member 14 away from mounting member 40 toward the end of the support member 14 . As mounting member 16 is moved the guide bars 30 pivot in relation to flanges 18 causing the leg members to move downwardly and outwardly in relation to the support member 14 until the legs are in a support position. Once in a support position, pull pin 28 is inserted through openings 24 and 26 to lock the legs in a support position.
[0018] Next, pull pin 28 on the second mounting member 40 is removed from openings 46 and 26 so that, using handle 48 , the second mounting member 40 is slid along support member 14 away from support member 16 toward control box 32 . As mounting member 40 is moved, spreader bars 56 pivot in relation to braces 42 causing the light assemblies 50 to move upwardly and outwardly to an extended position. Once in an extended position, the pull pin 28 is inserted through openings 46 and 26 to lock the light assemblies in an extended position. Once locked, switch 34 is activated which activates the lights and desired pattern as determined by the circuit board 36 .
[0019] Accordingly, a portable light system has been disclosed that, at the very least, meets all the stated objectives. | A portable lighting system having an elongated support member, retractable legs, retractable light assemblies, and multiple mounting members that slidably move along the support member to cause the legs and light assemblies to move from a retractable position to an extended and support position and back. | 5 |
CROSS REFERENCE TO RELATED APPLICATION
The present application claims the benefit of co-pending U.S. provisional patent application 60/737,304, filed Nov. 16, 2005.
FIELD OF THE INVENTION
This invention relates generally to luminaires and more particularly to luminaires adapted to direct light in a desired direction.
BACKGROUND OF THE INVENTION
Luminaires are used in many commercial and consumer venues to illuminate particular areas of a site, such as lighting for a service station, storefront or restaurant, and are typically mounted on or within a support structure such as a ceiling, canopy structure or building exterior.
Luminaires of currently existing designs are typically mounted on their support structures either by direct attachment to the structure or by creating an opening and installing the recessed luminaire into the opening. A typical drawback associated with many existing luminaires is that the lamp is mounted in a fixed position on or within the support structure, thereby prohibiting redirection of the light emanating from the lamp toward specific, desired areas below. Although lenses can be used to direct the light toward a particular area and focus the light output downward, a substantial portion of the luminous output of the lamp is nevertheless emitted in other directions.
Some existing luminaires permit movement of the luminaire body to direct the light output, most notably track lighting. However, such existing luminaires are not designed to withstand outside environments, such as weather and insects. Further, many have limitations in the rotational range of the lamps and cannot be easily locked into place. U.S. Pat. No. 6,802,627 to Fischer (“the '627 patent”) discloses an adjustable canopy luminaire capable of withstanding outdoor use. However, the luminaire of the '627 patent can only be tilted to a fixed predetermined angle relative to the opening by opening the door of the luminaire and then lifting and placing the lamp edge on tabs that are located within the housing. Thus, the luminaire of the '627 patent provides only a limited number of angles for aiming the lamp, and it is not possible to adjust the lamp from the outside of the housing.
Another common problem with canopy luminaires is the amount of electricity consumed by the lamp and the complexity of the lamp's electrical system. While a variety of types of lighting lamps can be used, including common fluorescent and incandescent lamps, luminaires in commercial applications often use high intensity discharge (HID) lamps to provide the desired level of lighting. The use of HID light sources can have many drawbacks. HID light sources are regulated by control gear, which may include a ballast alone or in combination with other components such as capacitors, igniters, or other such equipment. This control gear may be as large as or larger than the lamp itself. Further, the lamp and control gear are frequently contained within a box-like housing, which must be mounted to the support structure. HID light sources also use more electricity than lighting alternatives.
One other drawback associated with existing canopy luminaires, again relating to the difficulty in directing the light output toward the intended area, involves the need for using a larger lamp, such as a HID lamp, to provide the desired level of lighting. As the lens cannot efficiently direct the high intensity light to specific areas, much of the light is scattered toward unintended local and distant destinations. This scattering results in light pollution issues ranging from the disturbance of neighbors to interference of night sky viewing.
Thus, there is a substantial need for a luminaire that has increased adjustability over the prior art. It would also be advantageous to provide an externally adjustable luminaire that is easily and quickly adjusted from the outside of the luminaire housing. It would also be advantageous to provide an externally adjustable luminaire that can be aimed through its opening in an infinite number of angles and directions. There also exists a substantial need for a luminaire that may be easily and quickly adjusted to direct light toward a particular target area without scattering light to unintended areas. Further, there is a significant need for a luminaire that is capable of using a smaller lamp and consuming less electricity in its operation while providing the same degree of illumination.
SUMMARY OF THE INVENTION
The present invention provides a luminaire which overcomes drawbacks associated with the currently existing luminaires. More specifically, one aspect of the present invention is an adjustment mechanism for directing the emitted light from a lamp of a luminaire, the luminaire comprising a luminaire support structure; a door frame attached to the structure; a lamp shroud assembly comprising a shroud rotatably attached to the door frame and having an opening, and a lamp socket sized to receive the base of a replaceable lamp and electrically connectable to an electric power source, the adjustment mechanism comprising a movable external adjustment member and an internal mechanism attached to the external adjustment member through the shroud and indirectly connected to a portion of the lamp socket, the internal mechanism being movable in response to movement of the external adjustment member, wherein movement of the external adjustment member can change the angle of direction of light emitted from the replaceable lamp through the opening of the shroud.
Another aspect of the present invention is an externally adjustable directional luminaire comprising a luminaire support structure; a door frame attached to the structure; a lamp shroud assembly comprising a shroud rotatably attached to the door frame and having an opening, and a lamp socket sized to receive the base of a replaceable lamp and electrically connectable to an electric power source; an external adjustment member located on the outside surface of the shroud; and an internal mechanism movably connected to the external adjustment member through the shroud at one end and connected to the lamp socket at another end, the internal mechanism being movable in response to movement of the external adjustment member, wherein movement of the external adjustment member alters the angle of direction of light emitted from the replaceable lamp through the opening of the shroud.
In the various embodiments of the present invention, the lamp socket and the lamp are typically directed toward the opening of the shroud, and the opening is typically not perpendicular to the support structure, although it can be perpendicular thereto. Further, the rim edge of the shroud is typically formed with a projection to limit rotation of the shroud within the door frame to a maximum of a single revolution. Still further, the opening of the shroud can be covered by a lens.
The internal mechanism typically comprises a non-rotatable adjustment brace to receive the external adjustment member, a lever connected to the non-rotatable adjustment brace by a brace pin, a fulcrum mounted on the inner wall of the shroud and connected to the lever by a fulcrum pin, at least one mounting bracket connected to the lever by a bracket pin, a directional lamp harness mounted to the light supporting means and connected to the at least one mounting bracket by a bracket connector, and an internal support base mounted proximate the opening of the shroud and connected to the directional harness by a harness connector.
In one embodiment, the external adjustment member can be a threaded member, such as a bolt, rotatably received by a portion of the internal mechanism, whereby rotation of the threaded member is operable to cause the internal mechanism to move the lamp socket. The movement of the lamp socket by the internal mechanism can be with or without a mechanical advantage. In a particular embodiment, the external adjustment member can comprise a turnbuckle assembly, whereby screwing and unscrewing of the external adjustment member is operable to cause the internal mechanism to move the lamp socket.
In yet another embodiment, the external adjustment member can be a handle, wherein the internal mechanism comprises a rod connected to the handle at a first end and pivotally connected to the lamp socket at a second end, whereby pushing and pulling of the handle causes the internal mechanism to move the lamp socket.
The nature and advantages of the present invention will be more fully appreciated from the following drawings, detailed description, and appending claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with a general description of the invention given above, and the detailed description given below, serve to explain the principles of the invention.
FIG. 1 is a partial cross-sectional side view of one embodiment of the lamp shroud assembly and door of the present invention.
FIG. 2 is a partial cross-sectional side view of the lamp shroud assembly and door of FIG. 1 after external adjustment of the lamp.
FIG. 3 is a bottom perspective view of one embodiment of the lamp shroud assembly and door of the present invention.
FIG. 4 is a perspective view of a lamp as it sits within the lamp shroud assembly and door.
FIG. 5 is a top perspective view of the door frame and shroud in an open position away from the luminaire support structure.
FIG. 6 is a partial cross-sectional side view of another embodiment of the lamp shroud assembly and door of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The externally adjustable directional luminaire 10 , as depicted in FIG. 1 , comprises a door frame 12 , a rotatable shroud 14 having an opening 16 , and a lamp socket 18 associated with the shroud and sized to receive the base of a replaceable lamp 20 . The door frame 12 comprises at least one hinge 22 at one end, a clamp bar 24 at the other end, and a retaining lip 26 which defines a hole in the door 12 . The shroud 14 comprises a rim edge 28 that is of substantially similar dimension to the retaining lip 26 of the door frame 12 . The rim edge 28 of the shroud 14 extends over and is received by the retaining lip 26 of the door frame 12 , thereby securing and permitting rotation of the shroud 14 within the door frame 12 . The lamp 20 can be adjusted externally by turning an external adjustment member 30 , which includes an elongated shaft 31 that cooperates with an internal mechanism to move the lamp socket 18 and lamp 20 along line 200 at an angle θ relative to the central axis 100 of the opening 16 of the shroud 14 . The lamp 20 as shown is a reflector type or PAR lamp, but could be any type of lamp, including a HID, fluorescent or incandescent lamp associated with a separate reflector to direct the light along axis 200 .
Looking now at FIG. 2 , the external adjustment member 30 including the elongated threaded shaft 31 is rotatably secured to the shroud 14 at a first end by a first securing means 32 A. Threaded shaft 31 is threadably attached to a non-rotatable securing means 33 and a non-rotatable adjustment brace 34 , and is prevented from being threadably separated from the non-rotatable adjustment brace 34 at a second end by a second securing means 32 B. A lever 36 is pivotally connected near its mid-point to the non-rotatable adjustment brace 34 by brace pin 37 . Fulcrum 38 , mounted on the inner wall of the shroud 14 , is pivotally connected to one end of the lever 36 by fulcrum pin 39 , and a mounting bracket 40 is pivotally connected to the other end of the lever 36 by bracket pin 41 . A directional lamp harness 42 is mounted over the lamp socket 18 and lamp 20 and is pivotally connected at a position along its length to the mounting bracket 40 by bracket connector 43 . An internal support base 44 is mounted proximate the opening 16 of the shroud 14 and is pivotally connected to the proximal end of the directional harness 42 by harness connector 45 . A spring 46 extends from the fulcrum 38 to the distal end of the lamp harness 42 , and serves to stabilize the lamp 20 as it assumes its various positions within the shroud 14 .
It can be appreciated from FIG. 2 that the lamp 20 , which was aimed to direct light out of the opening 16 of the shroud 14 along line 200 and at an angle θ from the axis 100 of the shroud 14 in FIG. 1 , is now aimed to direct light out of opening 16 along line 200 and at a different angle θ from the axis 100 of the shroud 14 in FIG. 2 . This change in the angle θ is accomplished by external manipulation of the adjustment member 30 by a user. In practice, the shaft 31 of adjustment member 30 acts directly upon the non-rotatable adjustment brace 34 , which is part of an internal mechanism, whereby rotation of the external adjustment member 30 causes the shaft 31 to be screwed into or out of (depending upon which direction one turns) the non-rotatable adjustment brace 34 , starting a chain of events which ultimately moves the replaceable lamp 20 through angle θ with a mechanical advantage. More specifically, as the shaft 31 is screwed out of the securing means 33 of the non-rotatable brace 34 , lever 36 is pushed in an inward direction away from the shroud 14 . Lever 36 then causes mounting bracket 40 to pivot about bracket pin 41 . Mounting bracket 40 , connected to the directional lamp harness 42 via bracket connector 43 , pivots about the harness connector 45 , which is stationary and connected to the stationary internal support base 44 .
Thus, internal support base 44 acts as a fulcrum for the harness 42 , and since the harness 42 is rigidly secured to the lamp socket 18 , then the lamp socket 18 (and also the lamp 20 ) will move with the harness 42 as it pivots about the support base 44 . A mechanical distance advantage is gained because a relatively short distance of movement of the non-rotatable securing means 33 and adjustment brace 34 along the shaft 31 results in a larger distance of movement of the mounting bracket 40 , and in turn, the distance of movement of the bracket connector 43 results in an even larger distance of movement of the socket 18 . Therefore, the lamp socket 18 and lamp 20 are caused to move a relatively large distance (through angle θ) upon movement of the external adjustment member 30 a short distance, resulting in a mechanical advantage. Thus, the lamp 20 can be aimed along an infinite amount of lines 200 at an angle θ from the axis 100 of the shroud 14 , and a user can easily adjust the vertical direction of the light coming from the luminaire from outside the housing of the luminaire. Typically the angle θ can be altered by a user from between about −35° to about +35°, more typically from between about −20° to about +20°, relative to the axis 100 of the shroud.
FIG. 3 illustrates a bottom perspective view of one embodiment of the luminaire 10 of the present invention, showing the door 12 , the shroud 14 with its opening 16 , hinges 22 A and 22 B at one end, the clamp bar 24 at the other end, external adjustment member 30 housing the elongated shaft 31 on the outside of shroud 14 , and a securement 50 on the outside of the door 12 . The securement, shown as screw 50 , whose function will be explained in more detail below, is tightened or loosened as desired in order to restrict or allow rotation of the shroud 14 within the door 12 . It can be appreciated from viewing FIG. 3 that the external adjustment member 30 and screw 50 are both accessible to a user from the outside of the shroud 14 . Thus, the door 12 docs not need to be opened in order to adjust the vertical direction of light coming from the opening 16 , or to adjust the horizontal direction in which the opening 16 of the shroud 14 is aimed, in relation to the door 12 .
FIG. 4 is a perspective view of the lamp socket 18 and lamp 20 as they associate with the shroud 14 . The non-rotatable adjustment brace 34 can be seen as it receives the external adjustment member 30 . The directional lamp harness 42 is mounted over the lamp socket 18 and lamp 20 , and connected to the mounting bracket 40 by bracket connector 43 and to the internal support base 44 by harness connector 45 . Electrical wiring 56 exits the top of the lamp socket 18 and passes through the lamp harness 42 on its way to a connection (not shown) with second electrical wiring 57 . Second electrical wiring 57 is received by a second socket 59 , which is connected to a power source. Spring 46 extends from the fulcrum 38 to the distal end of the lamp harness 42 , and serves to stabilize the lamp 20 as it assumes its various positions within the shroud 14 . A top clamp 52 contacts the rim edge 28 of the shroud. Securement or screw 50 extends from beneath the door frame 12 and is threaded through an opening in the top clamp 52 . Upon tightening of the screw 50 , the top clamp 52 presses the shroud 14 and the door frame 12 together and frictionally restricts rotational movement of the coupled shroud 14 and door frame 12 . A plurality of guides 54 are secured with a screw into the door frame 12 , and flexibly contact the rim edge 28 to stabilize the movement of the shroud 14 as it rotates about the retaining lip 26 of the door frame 12 .
As illustrated in FIG. 5 , the directional luminaire assembly is shown coupled with a luminaire housing structure 58 . Electrical wiring 56 exits the lamp socket 18 and passes through a housing opening 60 and is connected to the electrical power source, accessible through the housing opening 60 . The luminaire is connected to the housing structure 58 via hinges 22 A, 22 B on one end and a flexible clamp mechanism on the other end, including a receiving flexible clamp 62 and the clamp bar 24 that fits into and is held by the clamp 62 .
FIG. 6 illustrates another embodiment of the luminaire of the present invention, in which the external adjustment member 130 with its elongated shaft 131 is part of a turnbuckle assembly associated with another embodiment of the internal mechanism which includes a non-movable nut 132 rigidly connected to turnbuckle bar 134 . The shaft 131 of the external adjustment member 130 is rotatably secured to the shroud 14 by securing means 133 . Turnbuckle pin 136 pivotally connects the turnbuckle bar 134 to the lamp socket 18 . In use, screwing and unscrewing of the shaft 131 via member 130 causes the internal mechanism to laterally move the lamp socket 18 and lamp 20 . Typically, the lens end of the lamp 20 is fixed in position proximate the opening 16 of the shroud 14 . More specifically, as member 130 is turned, the elongated shaft 131 is screwed into or out of the non-movable nut 132 (depending on which direction the member 130 is turned), causing the turnbuckle bar 134 to laterally push or pull the lamp socket 18 . Thus, as the lamp 20 is moved by the turning of the external adjustment member 130 from a first position in which light is aimed along line AA to a second position (shown in phantom) in which light is aimed along line BB, it can be positioned at any position along angle CC, so that the desired vertical direction of the light coming from the shroud is achieved. In the embodiment shown in FIG. 6 , retaining clips 138 and 142 are located on either side of the lamp 20 in order to stabilize and fix the position of the lens end of the lamp. Support 140 anchors the retaining clips 138 , 142 within the shroud 14 .
In an alternative embodiment (not shown), the external adjustment member can be a simple handle and the internal mechanism can be a rod pivotally connected to the lamp socket at one end and linearly connected to the handle at another end, whereby pushing and pulling of the handle causes the internal mechanism to laterally pivot or move the lamp socket. With this embodiment, like the embodiment of FIG. 6 , the linear movement of the internal mechanism caused by movement of the external adjustment member is equivalent to the angular movement of the lamp socket, providing no mechanical advantage.
In the various embodiments of the present invention, the lamp socket 18 and the lamp 20 are typically directed toward the opening 16 of the shroud 14 , and the opening 16 is typically not perpendicular to the support structure. However, embodiments of the luminaire are envisioned in which the opening is perpendicular to the support structure. Assuming that the support structure is typically parallel with the ground so that a vertical line passing from support to the ground is an angle of 0°, then the angle of the line 100 , which corresponds to the axis of the shroud 14 , is typically at an angle from about 10° to about 80° from vertical, more typically about 30° to 60°. The external adjustment means of the present invention further allows the line 200 of light emitted from lamp 20 to be altered at an angle θ from line 100 . Typically the angle θ can be altered by a user from between about −35° to about +35°, more typically from between about −20° to about +20°, relative to the axis 100 of the shroud. Further, the shroud 14 can be rotated up to 360° within the door frame 12 . The rim edge 28 of the shroud 14 is typically formed with a projection to limit rotation of the shroud 14 within the door frame 12 to a single revolution. Still further, the opening of the shroud 14 can be covered by a lens.
While the present invention has been illustrated by description of several embodiments which have been described in detail, it is not the intention of the applicant to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages will readily appear to those skilled in the art. Thus, the invention in its broadest aspects is not limited to the specific details, representative apparatus and method, and illustrative examples shown and described. Accordingly, departures may be made from the details without departing from the spirit or scope of applicant's general inventive concept. | An externally adjustable directional canopy luminaire is disclosed that may be easily and quickly adjusted from the outside of its housing to direct light toward a particular target area. The luminaire includes a lamp shroud assembly including a door frame, a shroud and a lamp socket which is connectable to an electrical power source to power a replaceable lamp, an external adjustment member, and an internal mechanism movably connected to the external adjustment member through the shroud and indirectly connected to a portion of the lamp socket, wherein adjustment of the external adjustment member can alter the angle of direction of the lamp socket and thus the direction of light emitted from the replaceable lamp through the opening of the shroud. | 5 |
FIELD OF THE INVENTION
The present invention relates to methods of suppressing fugitive dust emissions by applying an aqueous foamed solution including a water-soluble cationic polymer to dust producing bulk solids. More particularly, the present invention relates to methods for providing residual or long term fugitive dust control for bulk granular or powdered solids with an aqueous foamed solution including a water-soluble cationic polymer. The aqueous solution may be foamed by incorporation therein of an anionic, amphoteric or cationic foaming agent.
BACKGROUND OF THE INVENTION
Dust dissemination poses safety, health, and environmental problems in many commercial environments. For instance, in many industries, the transportation handling and storage of bulk solids is common as in industries such as mining, mineral processing, agricultural, power, steel, paper, etc. One major problem associated with bulk solids is dust generation and the control of fugitive dust emissions.
Industrial sources of fugitive dust include open operations, leaks and spills, storage, disposal, transit or poor housekeeping of sundry finely divided solid particulates. The iron and steel industries are replete with examples of the above enumerated categories. Wind erosion of exposed masses of particulate matter such as coal or mine mill tailings, fertilizer, etc., causes both air pollution and economic waste. Detrimental effects on health and cleanliness result where these fine particles are carried aloft by the winds.
A typical method for controlling the dust is to apply a water spray. However, water sprays only control dust for a short period of time depending upon environmental conditions. The application of the spray has to be repeated frequently to provide ongoing dust control. U.S. Pat. No. 3,954,662 discloses aqueous foamable compositions and their use to suppress coal dust. The composition contains water, an interpolymer of a polymerizable vinyl ester and a partial ester compound interpolymerizable with the vinyl ester, and a detergent wetting agent. The interpolymer binds coal dust and keeps the dust particles encapsulated after the foam has collapsed.
U.S. Pat. No. 4,087,572 discloses a combination of an organic polymer latex such as a styrene-butadiene interpolymer and a silicone applied to the surface of a coal pile or other mass of finely divided particulate materials. In addition, a wetting agent may be incorporated to prevent premature coagulation. The combination is applied as an aqueous mixture such as by spraying.
U.S. Pat. No. 4,551,261 discloses the suppression of dust with an aqueous foam comprising a foaming agent and an elastomeric water insoluble polymer. The foam provides immediate dust suppression and eases application. The polymer coats the material and continues to suppress dust generation during handling of the material after the foam has collapsed.
U.S. Pat. No. 4,594,268 discloses the use of at least one methacrylate polymer for dust suppression. The methacrylate polymer provides dust suppression when applied to a wide variety of materials. After application, the polymer provides a tacky, water resistant coating which effectively prevents dusting while additionally acting as an anti-freeze agent.
U.S. Pat. No. 4,801,635 discloses a combination of water soluble anionic acrylic polymers and nonionic glycol polymers and anionic and nonionic surfactants useful for the control of dust emissions into the environment.
U.S. Pat. No. 4,780,233 discloses a method and composition for controlling fugitive dust particles which comprises an oil containing dust control treatment including a small amount of a water insoluble elastomeric polymer. The inclusion of a small amount of elastomer significantly improves the dust control performance. The composition can be applied as a spray or foam.
SUMMARY OF THE INVENTION
The present invention relates to improved methods and compositions for controlling fugitive dust emissions from bulk, granular or powdered solids. Fugitive dust emissions are controlled by applying an aqueous, foamed solution including a water-soluble cationic polymer to dust producing bulk, granular or powdered solids. The cationic polymer is incorporated into an aqueous foam comprising anionic, amphoteric or cationic foaming agents. Wetting agents such as nonionic ethoxylated alcohols may also be included for improved wetting of the solid substrate. For materials with a propensity for caking or similar handling problems, anti-caking agents or flow aids may be included such as cationic amines, tallow primary amines, mineral oils, etc.
The dust control methods and compositions of the present invention are particularly effective at controlling fugitive dust dissemination in urea processing and handling. In the treatment of urea for dust control in accordance with the present invention, anti-caking agents or flow aids are particularly desirable due to the tendency of urea to cake. The compositions and methods of the present invention provide effective residual or long term dust control.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The dust control composition of the present invention is an aqueous solution of a water soluble cationic polymer. These materials may be selected from a wide variety of water-soluble cationic polymers. The polymers may be either addition polymers or condensation polymers. Most synthetic cationic polyelectrolytes are polyamine and polyquaternary ammonium salts although non-nitrogen based cationic species are known. Polyamines and polyquaternary amines can be prepared by free-radical chain polymerization, epoxide-addition reactions, condensation polymerization, and reactions on polymer backbones. Polymers of this type are described in Roe, U.S. Pat. No. 4,426,409, the disclosure of which is incorporated herein by reference. Polyamines and polyquaternary anions are also discussed at pp 489-507 of The Encyclopedia of Polymer Science and Engineering, Vol. 11, Second Edition, 1988.
The treatment solution is preferably supplied as a concentrate which is diluted prior to application as a foam. The treatment concentration, in percent cationic polymer by weight in the foam, can range from about 0.01 to 10.0% and is preferably from about 0.1 to 1.0%. The feed rate of foam onto the substrate, on a weight % basis, can range from about 0.05 to 5.0% and is preferably from about 0.1 to 1.0%.
The dust control composition of the present invention is applied as a foam. The foam for the dust control treatment may be foamed and applied via conventional techniques such as those disclosed in U.S. Pat. No. 4,400,220 (Cole), the contents of which are hereby incorporated by reference. Accordingly, a suitable foaming agent is included.
Cationic and amphoteric foaming agents are preferred. Amphoteric foaming agents such as coco amido sulfobetaines are especially preferred. Such foaming agents are available commercially. For example, EMCOL 6825 available from Witco Chemical Corporation. In general, cationic polymers cannot be foamed with anionic foaming agents. However, the inventor of the present invention discovered that the cationic polymer of diethylenetriamine/adipic acid/epichlorohydrin can be foamed with an anionic foaming agent comprising a blend of the sodium salts of C14-C16 alpha olefin sulfonate and alkyl ether sulfate. Exemplary commercial products are Bioterg AS-40 and Steol KS-460 available from Stepan Chemical Co. It is believed, therefore, that other anionic foaming agents may also be capable of foaming this and other cationic polymers.
The present invention will now be described with respect to a number of specific example which are to be regarded solely as illustrative and not as restricting the scope of the invention.
EXAMPLES
Laboratory testing was conducted to determine the dust control effects of water-soluble cationic polymer compositions on feed grade urea. The polymers were applied to the urea as aqueous foams with cationic and anionic foaming agents. The effectiveness was tested by measuring the relative dusting index (RDI) and percent dust suppression (% DS). The RDI of treated and untreated control samples was measured in a laboratory dust chamber equipped with an opacity monitor. The opacity monitor generated an opacity curve as a function of time, measured after introduction of the treated samples into the dust chamber. The relative dustiness index was measured as the area under the opacity curve. The percent Dust Suppression was a calculation based on the Relative Dustiness Index for untreated versus treated materials. All samples were aged for 24 hours at 20° C. and 50% relative humidity prior to testing.
Table I summarizes the results of testing showing the large decrease in RDI and relatively high % DS numbers for a variety of water-soluble cationic polymer treatments in accordance with the present invention.
TABLE I______________________________________Effects of Foamed Cationic Polymers onRelative Dustiness (RDI) of Feed Grade Urea Concentration (% Polymer Feed RateTreatment in Foam) (Wt % of Foam) RDI % DS______________________________________Control -- -- 11.1 --Control -- -- 12.2 --A 0.25 0.22 2.3 80.3B 0.25 0.23 2.5 78.6C 0.25 0.22 2.8 76.1D 0.25 0.23 4.1 65.0______________________________________ Legend: A: Melamine/formaldehyde polymer and coco amido sulfobetaine cationic foaming agent. B: diallyldimethyl ammonium chloride polymer and coco amido sulfobetaine cationic foaming agent. C: diethylenetriamine/adipic acid/epichlorohydrin polymer and coca amido sulfobetaine cationic foaming agent. D: diethylenetriamine/adipic acid/epichlorohydrin polymer and an anionic foaming agent.
As shown in Table I foamed cationic polymers provide effective dust suppression.
While the present invention has been described with respect to particular examples, 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 should be construed to cover all such obvious forms and modifications which are within the spirit and scope of the present invention. | A method for controlling fugitive dust emissions from bulk granular or powdered solids is disclosed. Fugitive dust emissions are controlled by applying an aqueous, foamed solution including a water-soluble cationic polymer to dust producing bulk, granular or powdered solids. The cationic polymer is incorporated into an aqueous foam comprising anionic, amphoteric or cationic foaming agents. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of and incorporates by reference application Ser. No. 10/316,135, filed Dec. 10, 2002, now U.S. Pat. No. 6,768,894 which is a continuation of application Ser. No. 09/624,444, filed Jul. 24, 2000, now U.S. Pat. No. 6,493,536, which is a continuation of application Ser. No. 08/986,022, filed Dec. 5, 1997, now U.S. Pat. No. 6,267,601, all of which are commonly owned with the present invention and which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to systems and methods for teaching scoring and for assessing scoring effectiveness and, more particularly, to such systems and methods for teaching and assessing holistic scoring.
2. Description of Related Art
The automation of test scoring is a complex problem that has generated a great deal of interest, owing to a significant economic pressure to optimize efficiency and accuracy and to minimize human involvement. Open-ended or essay-type questions must typically be scored by a human reader, and thus either the physical test form or a visible image thereof must be available for at least the time required for scoring. In addition, scorers (also referred to as readers or resolvers) must be trained in order to become accomplished in analyzing and scoring the answers to open-ended questions effectively, accurately, and quickly.
Computerized systems for scoring open-ended questions are known in the art. In addition, such systems are known that provide feedback to a scorer on validity, reliability, and speed based upon a standard question and model answer. For example, Clark and Clark et al. (U.S. Pat. Nos. 5,321,611; 5,433,615; 5,437,554; 5,458,493; 5,466,159; and 5,558,521) disclose systems and methods for collaborative scoring, wherein scores of two or more resolvers are compared, and a record is kept of each of the resolver's scores. This group of patents also teach the collection of feedback on a resolver, which includes the monitoring of scoring validity, reliability, and speed. One of the criteria is a calculation of a deviation of the resolver's score and a model score by using “quality items.” Also discussed is an online scoring guide for use by the resolver during scoring.
However, there are no systems and methods known in the art that are specifically directed to the teaching of scoring open-ended questions and to providing scoring rules; model answers, scores, and rationales therefor; and feedback to a resolver during the teaching process.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a system and method for assessing a scorer's grading of an open-ended question.
It is an additional object to provide such a system and method for interactively assisting a scorer in learning a holistic scoring technique.
It is another object to provide such a system and method for tracking a scorer's progress during a practice session.
It is a further object to provide such a system and method for practicing holistic scoring in a variety of content domains such as, but not limited to, reading, writing, science, and mathematics in the same program.
It is yet another object to provide such a system and method for presenting a set of holistic scoring rules, or rubric, to the scorer.
These and other objects are achieved by the system and method of the present invention. One aspect of the method is for teaching a scorer holistically to score an answer to an open-ended question. Holistic scoring is a technique whereby a unitary, typically numerical, score is given for an answer to an open-ended question; for example, in an essay-type response, spelling and grammatical errors and content are all taken into account when granting the score.
The teaching method comprises the step of displaying a student response, which in a particular embodiment may be chosen by the scorer to be presented in handwritten or typed text form, to an open-ended question to a scorer. In a preferred embodiment the scorer is permitted to access for display a scoring rubric for the question, which comprises a set of rules on which the scoring for that question should be based. The scorer then assesses the response and enters a score for the response, which is received by the system. Finally, a model score is presented to the scorer. A comparison of the model score with the scorer's entered score permits him or her to assess his or her scoring efficacy, that is, how close the entered score came to the model score prescribed for the response.
The tutorial software program of the present invention, which may also be referred to simply as a tutorial, in a preferred embodiment comprises a plurality of databases, or, alternatively, a plurality of sectors in a unitary database, containing:
1. A plurality of student responses to an open-ended question. Preferably, each student response is present in an original handwritten image form and in a text form. The text form retains all original errors from the handwritten image.
2. A model score for each student response.
3. A scoring rubric for each question.
4. An analysis of each student response and a rationale for the model score for each student response.
The teaching system of the present invention comprises a computer, or data-processing system, such as, for example, a personal computer or workstation. The computer has resident therein, or has means for communicating with a storage device having resident thereon, a database as described above.
The system also comprises means for displaying a student response to a question to a scorer, means for permitting the scorer to access the scoring rubric for the question, means for receiving a score from the scorer. As described above, these means typically include a personal computer or networked workstation having a keyboard, screen, pointing device, and communication means for accessing a storage device.
Software means are also resident in the computer for presenting on the display means a model score to the scorer to permit the scorer to assess his or her scoring efficacy, that is, how close the assigned score is to the model score. The software means also comprises means for displaying an explanation or annotation of the model score assigned. In addition, means are provided within the processor for tracking the scorer's progress during a practice session with the tutorial. This tracking is preferably accomplished by calculating a running correlation between the model answer and the score entered for each response.
The invention contemplates a system and method for teaching a scorer within a chosen level and discipline. For example, a particular tutorial may comprise a set of questions keyed to a grade level in a particular subject area (e.g., grade 7, history) or in related areas (e.g., grade 8, reading and writing, wherein reading competency is assessed by a student's response to a question on a reading selection, and writing competency is assessed by the student's response to an essay-type question). Alternatively, a set of responses to questions may address the subject matter contained in a professional licensing or qualification examination (e.g., for a laboratory technician).
The features that characterize the invention, both as to organization and method of operation, together with further objects and advantages thereof, will be better understood from the following description used in conjunction with the accompanying drawing. It is to be expressly understood that the drawing is for the purpose of illustration and description and is not intended as a definition of the limits of the invention. These and other objects attained, and advantages offered, by the present invention will become more fully apparent as the description that now follows is read in conjunction with the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a logic flowchart for the method of the present invention for teaching a scorer in a holistic scoring technique.
FIG. 2 is a schematic diagram of the system of the present invention.
FIG. 3 illustrates an exemplary opening menu for the tutorial program.
FIG. 4 illustrates a series of exemplary answers to a question on a reading selection, representing (A) a high reading; (B) medium reading; and (C) low reading models for a Grade 8 student. (D) A typed text version of the low reading model of (C).
FIG. 5 illustrates the first pages of a series of exemplary essays on a prescribed topic, representing (A) a high writing; (B) medium writing; and (C) low writing models for a Grade 8 student. (D) A typed text version of the low writing model of (C).
FIG. 6 represents an exemplary screen displaying a scoring rubric for reading.
FIG. 7 illustrates a model analysis of a response.
FIG. 8 illustrates a cumulative summary table of a scorer's performance.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A description of the preferred embodiments of the present invention will now be presented with reference to FIGS. 1–8 .
In a preferred embodiment of the system 60 of the invention, illustrated in FIG. 2 , a person 20 desirous of receiving instruction in holistic scoring is provided with access to a processor. The means or access may comprise a personal computer or a workstation 61 or terminal networked to a server computer 62 , or an interface to a remote site through telecommunications, internet, or other forms of data transmission, although these architectures are not intended to be limiting. The processor 62 has loaded thereon the tutorial software program 10 of the present invention, which will be described in the following. The computer access/interface is preferably provided by means well known in the art, e.g., via a display screen 64 , keyboard 66 , and pointing device 68 such as a mouse, for use in a Windows®-type or Macintosh® environment.
A first aspect of the method ( FIG. 1 ) is for teaching a scorer to holistically score an answer or response to an open-ended question (also referred to as an “assessment” or “assessment form” in the art) via a computer-driven tutorial program 10 . The method comprises the steps of starting the tutorial program 10 (Step 99 ) and providing a choice to the scorer 20 of which section or module of the program 10 to enter (Step 100 ). In a preferred embodiment this choice is presented in the form of a screen-displayed menu ( 30 , FIG. 3 ) in a Windows®- or Macintosh-type format. This is not intended to be limiting, however, as those skilled in the art will recognize alternate platforms and modes of providing such a selection. In this particular embodiment, two major divisions include introductory (choices 1–3, 211 – 213 ) and scoring practice (choices 4 and 5, 214 , 215 ) sections.
A first choice from the menu 30 comprises an overview ( 211 , Step 101 ) of the tutorial 10 , which introduces the scorer 20 to basic principles of integrated performance assessment and holistic scoring. The rationale underlying the development of this form of assessment and a general introduction to holistic scoring are offered.
A second choice from the menu 30 comprises a description of a particular assessment ( 212 , Step 102 ), including its content, how to prepare for scoring responses, such as reading and writing responses to that assessment, and how to apply the rubrics.
A third choice from the menu 30 comprises a guided tour of the scoring section ( 213 , Step 103 ). This section provides an annotated screen-by-screen preview of the scoring training program.
The practice division begins with a fourth choice from the menu 30 , a review of model papers, rubrics, and annotations ( 214 , Step 104 ). This section allows the scorer 20 to try out the training program's features before entering the actual scoring module ( 215 , Step 105 ). Here the scorer can explore the rubrics for selected parameters such as, but not limited to, reading, rhetorical effectiveness, and conventions. The scorer 20 can view model student answers to illustrate, for example, high, medium, and low levels of performance. Exemplary responses are presented in FIGS. 4A–C , which represent high, medium, and low model written responses, respectively, to two questions on a reading selection, and FIGS. 5A–C , which represent the first pages of high, medium, and low model written essays on a prescribed topic. Note that in the case of FIGS. 5A–C , a dual score is given, one for “rhetorical effectiveness” and one for “conventions.” In addition, the scorer 20 can read annotations that analyze the answer and explain the scores assigned ( FIG. 7 ).
The final selection offered on the menu 30 comprises the scoring practice module ( 215 , Step 105 ), in which the scorer 20 can apply what has been learned in the preceding modules 211 – 214 . A plurality of practice answers are provided for each assessment, preferably representing the gamut of “poor” to “excellent” responses.
In the scoring practice module 215 a first student response to an open-ended question is retrieved from a database 250 of student responses and is displayed to the scorer 20 (Step 106 ). (Here the word student is not intended to be limiting, but should be taken in the broad context of any person taking a test, which could include, for example, a person taking a licensing examination or professional or technical evaluation test.) This step 106 in a preferred embodiment further comprises providing a means for the scorer 20 to select a display mode (Step 107 ). The display mode can be one of an original handwritten form (Step 108 ) or a typed (or “keyboarded”) text form (Step 109 ), wherein the typed text form retains all errors in the original handwritten form, such as spelling, grammatical, syntactical, and punctuation mistakes (see, for example, FIGS. 4 C,D and 5 C,D, which represent the handwritten and typed text versions of the same responses).
The scorer 20 is permitted at any time during scoring to access a scoring rubric 220 for the question from a scoring rubric database 251 ( FIG. 6 , Steps 110 , 111 ). Each rubric contains an indication of what a numerical score 222 represents, including both a brief descriptor (e.g., “exemplary reading performance” 224 ) and an extensive description of each score point 226 (see FIG. 6 ). This scoring rubric is typically accessed by the scorer 20 via selecting an icon on the screen 64 with the pointing device 68 , although this method is not intended to be limiting.
Once the scorer 20 has reviewed the response (Step 112 ), a score is entered (Step 113 ), for example, by selecting a number from a button bar 642 on the screen 64 with the pointing device 68 . Such methods of selecting from a variety of options is well known in the art, and other, comparable selection methods may also be envisioned, such as entering a number from the keyboard 66 .
When the score has been entered, a model score 228 is retrieved from a database of model scores 252 and is presented to the scorer 20 (Step 114 ) to permit him or her to assess the scoring efficacy. In addition, an analysis of the answer is retrieved from a database 253 and is presented (Step 115 ) on the screen 64 to enable the scorer 20 to review his/her score in light of comments of experienced scorers. In the example of FIG. 7 , the analysis covers a student's responses to a number of questions on a reading selection, two of which are included in the high reading model of FIG. 4A . The scorer's score is also stored (Step 116 ), and a correlation is calculated and presented of that score with the model score ( FIG. 8 and Step 117 ).
In order to refine the skills learned thus far, the scorer 20 will typically choose to practice on further assessments (Step 118 ), and thus preferably a plurality of responses are available for scoring. As an example, a range of responses representing “low” to “high” models, such as the A–C parts of FIGS. 4 and 5 , are available, as well as answers to several different assessments, such as represented in FIGS. 4 and 5 , which are responses to reading and writing assignments, respectively.
After entering each score and displaying the model score therefor, the scorer 20 is presented with a cumulative summary table 80 ( FIG. 8 and Step 117 ), which updates and displays the percentage of agreement between the scorer's evaluation and that of an experienced scorer. For example, the scoring status screen of FIG. 8 tabulates for each paper 87 a column for “your score” 81 and a column for a model, or “consensus score” 82 . Also presented is a table of “percentage of agreement” 83 , including a percentage of “exact agreement” 84 with the model score, a percentage of scores that “differ by 1” 85 , and a percentage of scores that “differ by 2 or more” 86 . This particular arrangement is not intended to be limiting, as one of skill in the art could imagine any number of similar correlation calculations and modes or presentation. The concept of a summary table is intended to provide an indicator of progress in learning the holistic scoring technique.
If the scorer 20 wishes to end the tutorial session (Step 118 ), the “Quit” button 216 on the menu 30 may be selected (Step 119 ).
It may be appreciated by one skilled in the art that additional embodiments may be contemplated, including similar methods and systems for training personnel in scoring open-ended questions for other fields.
In the foregoing description, certain terms have been used for brevity, clarity, and understanding, but no unnecessary limitations are to be implied therefrom beyond the requirements of the prior art, because such words are used for description purposes herein and are intended to be broadly construed. Moreover, the embodiments of the apparatus illustrated and described herein are by way of example, and the scope of the invention is not limited to the exact details of construction.
Having now described the invention, the construction, the operation and use of preferred embodiment thereof, and the advantageous new and useful results obtained thereby, the new and useful constructions, and reasonable mechanical equivalents thereof obvious to those skilled in the art, are set forth in the appended claims. | A tutorial method for teaching the scoring of open-ended questions holistically includes displaying a student response to a scorer and permitting the scorer to access a rubric containing the rules for scoring that response. The scorer can choose a display form from a handwritten form and a typed text form that retains and originally present errors. Following the scorer's having entered a score, a model score is displayed so that a scoring efficacy may be determined. Annotations prepared by expert scorers may be accessed to enhance the learning process. In addition, a running correlation between the model and entered scores is calculated and displayed for the scorer over a tutorial session that includes attempts at scoring different responses. The system includes a processor, a workstation, and software for performing the above-described method. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present patent application claims priority from Great Britain Patent Application No. GB 0422782.3, filed on Oct. 14, 2004.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to pipe assemblies, and in particular, but not exclusively, to underwater pipe assemblies for conveying oil, gas, condensate and other fluids.
[0003] When fluids are extracted from an underwater wellhead, it is typically necessary to convey them to a production platform where they can be distributed to, for example, a tanker or into a further pipeline for onward transmission. This is normally achieved by means of a steel riser which extends between a production platform and the wellhead, with a flowline connecting the lower end of the riser to the wellhead.
[0004] The fluid which emerges from the wellhead is at an elevated temperature (usually between 80-90 C but sometimes far higher). It is important to maintain the hydrocarbons in the riser at an elevated temperature, since excessive cooling may cause components of it to solidify, resulting in blockage of the riser and loss of production. This can be a significant problem since risers can be of considerable length and they often pass through water which is only a few degrees above freezing point. Such problems are not necessarily unique to undersea risers. Other forms of pipeline, for example overland pipelines, may suffer from similar problems.
[0005] It is known to provide fluid-carrying pipes with exterior thermal insulation. The applicant's own published International patent application WO 02/16726 concerns a pipe assembly surrounded by syntactic foam insulation. Such insulation can be moulded in situ upon a metal riser. The process involves placing a section of the metal riser within a mould formed as a tube of polymer material. Spider structures at intervals along the length of this assembly locate the tubular mould relative to the riser. End caps are provided to prevent escape of the moulding material, which is then introduced between the riser and the mould to form an annular insulating layer. The tubular mould, which may be formed from a tough material such as polyethylene, can be left in place upon the pipe assembly to form a durable outer skin. Typically the sections treated in this way can be in the order of 12 meters in length. End portions of the inner metal riser are typically left exposed, beyond the ends of the moulded insulation, to allow the ends of two such riser sections to be welded together. If desired, insulation may be subsequently cast in place over the welded joint.
[0006] A problem has now been identified relating to possible slippage of the polymer skin along the length of the pipe assembly. The favoured material, polyethylene, typically forms a poor bond with resin material used in the moulded insulation. The weight of the riser itself, and the consequent tension therein, can be very large indeed. Where the riser is handled through the outer skin, e.g. during its assembly and deployment, there is a consequent risk that the skin will move longitudinally relative to the insulation and the riser within. This is not only undesirable but also potentially dangerous.
SUMMARY OF THE INVENTION
[0007] In accordance with a first aspect of the present invention there is a method of constructing an insulated pipe assembly, comprising:
[0008] providing an inner pipe,
[0009] providing a tubular outer skin comprising polymer material,
[0010] shaping an interior surface of the tubular outer skin to provide a mechanical key,
[0011] arranging the tubular outer skin around the inner pipe, and
[0012] introducing settable insulation material between the inner pipe and the tubular outer skin,
[0013] such that following setting of the insulation material it forms an insulating layer which is mechanically keyed to the interior surface of the outer skin.
[0014] The mechanical key between the insulation material and the tubular outer skin is found in practice to prevent slippage of the outer skin.
[0015] The shape formed upon the interior surface of the tubular outer skin could in principle take any number of forms. However, it is particularly preferred that it comprises at least one groove, which can conveniently be cut using some form of cutting tool. The groove may be helical, which is convenient where a turning process is used to form it. Preferably the shape comprises helical grooves with opposite angles. That is, one such groove is formed in the manner of a left-hand thread and another is formed in the manner of a right-hand thread. In this way the skin and insulation material are prevented from moving relative to each other in the manner of a screw.
[0016] It is particularly preferred that the shaping of the interior surface of the tubular outer skin is carried out using a modified honing tool.
[0017] Preferably, a cutting tool is mounted upon a lance which is movable in a direction along the length of the pipe assembly, the cutting tool in use being brought into contact with the inner surface of the outer skin and moved along the pipe assembly by means of the lance whilst either the lance or the pipe assembly is rotated to form a helical groove.
[0018] In accordance with a second aspect of the present invention there is a pipe assembly comprising an inner pipe, a tubular outer skin which comprises polymer material and which is arranged around the inner pipe, and a layer of moulded insulation material interposed between the inner pipe and the outer skin, wherein the outer skin has an interior surface which is shaped to provide a mechanical key and which is in intimate engagement with the adjacent surface of the moulded insulation material.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] A specific embodiment of the present invention will now be described, by way of example only, with reference to the accompanying drawings in which:
[0020] FIG. 1 is a section through a pipe assembly embodying the present invention, taken in a radial plane;
[0021] FIG. 2 is a section through one wall of the same pipe assembly, taken in an axial plane;
[0022] FIG. 3 is a partially sectional view of a pipe assembly embodying the present invention taken in an axial plane, an end-cap used in the moulding process being shown in situ;
[0023] FIG. 4 is a section in an axial plane through a tubular outer skin forming part of the same pipe assembly; and
[0024] FIG. 5 is a schematic illustration of an arrangement used to shape the interior of the said outer skin.
DETAILED DESCRIPTION OF THE INVENTION
[0025] FIGS. 1-3 show a pipe assembly in which a steel riser 2 used for sub-sea hydrocarbon extraction is surrounded by and encased in an annular layer 4 of insulation material. The riser is separated from the insulation material by a conventional fusion-bonded epoxy tie-coat 6 . Around the outside of the insulation material 4 is an outer skin 8 which in this embodiment is formed of high density polyethylene (HDPE).
[0026] The insulation material 4 is moulded in situ upon the riser 2 . In this process the riser 2 is first fitted with spacer structures and then drawn into the outer skin 8 , which is of tubular form. The spacers serve to position the outer skin 8 generally concentrically upon the riser 2 , so that an approximately annular cavity is formed between them. An end-cap 10 is fitted over the end of the outer skin 8 and has a tapered shape so that it can form a seal with both the outer skin 8 and the riser 2 through respective neoprene collars 12 , 14 .
[0027] The spacers (not seen in the drawings) eventually form part of the layer of insulation material 4 and are in the present embodiment formed of the same polymer material used in forming the insulating layer. For the moulding process itself, the riser 2 is inclined to the horizontal and macrospheres 16 are introduced into the annular volume between the riser 2 and the outer skin 8 . In the drawings the macrospheres appear to be regularly arranged, but in this respect the drawings are simplified. In practice a random arrangement is achieved. Macrospheres are in themselves well known to those skilled in the art and are low density spherical bodies, often having a core of expanded polystyrene with a crush resistant outer skin of fibre reinforced plastics. After introduction of the macrospheres 16 , the upper end of the mould is sealed using a second end-cap (which is not seen in the drawings but is similarly formed to the first end-cap 10 ). Moderate heating may be applied. In the present example the mould is heated to a nominal 40° C. Polymer material, in resinous form, is then injected into the annular volume via ports along the length of the outer skin 8 . The polymer material used in the present embodiment, comprising polyurethane with an admixture of hollow glass microspheres, is referred to as “glass syntactic polyurethane” or GSPU. The polyurethane used in the present embodiment comprises a polyol blend, which is loaded with the microspheres, and an isocyanate component. Prior to use these components are placed under a vacuum to remove any air that might otherwise contribute to void formation, and are then held in separate heated storage tanks. During processing they are brought together in a mixing head through respective pumping units in the recommended proportions.
[0028] It should be understood that other forms of moulded insulation, including other types of syntactic foam could in practice be used. Macrospheres could be dispensed with in applications where density is not critical.
[0029] Once the mould is filled, the polymer material is allowed to cure and the end-caps are removed before the pipe is taken from the casting station to cool on a storage rack. The cut backs are trimmed and cleaned of any release agent transferred from the end-caps 10 . Quality control inspections are then carried out.
[0030] The bond formed between the insulation material 4 and the tie-coat upon the riser 2 is good. Cleaning and mild abrasion of the tie-coat 6 are carried out prior to the moulding process to ensure this. As noted above, however, a good bond cannot be ensured to the outer skin 8 .
[0031] In order to resist slippage of the outer skin 8 relative to the insulation material 4 within it, a mechanical key is provided on the interior surface of the outer skin 8 prior to the moulding process. It comprises some arrangement of hollows and/or projections to which the moulded insulation material 4 will conform, resulting in intimate mechanical engagement between the adjacent surfaces of the outer skin 8 and the insulation material 4 which resists subsequent displacement of one relative to the other. In the present embodiment, the requisite mechanical key takes the form of helical grooves formed upon the interior surface of the outer skin 8 , as seen at 17 , 18 in FIG. 4 . The illustrated skin has grooves with opposite (and not necessarily equal) pitch angles. That is, one groove 17 is formed in the manner of a left-hand thread and the other 18 , in the manner of a left-hand thread.
[0032] The groove is formed by a turning process. A cutting tool is inserted into the tubular outer skin 8 and traversed along its length while either the tubular skin or the cutting tool is rotated to form the helical grooves 18 . FIG. 5 shows a suitable arrangement in highly schematic form. The cutting head 19 is seen to be mounted upon a longitudinally movable lance 20 aligned with the axis of the tubular outer skin 8 and rotatable thereabout. In this arrangement a set of cutting tools 22 , akin to the tooling used in a conventional lathe, is provided and is angularly spaced about the axis of the lance. The tools are mounted upon respective radially movable stubs 24 to allow them to be advanced along the radial direction into cutting contact with the inner surface of the tubular outer skin 8 . The multiple tools may be used to form several grooves in the manner of a multi-start thread or, depending upon their longitudinal spacing and the pitch of the thread being cut, they may serve each to deepen a single groove. Cutting of the two oppositely-handed threads 17 , 18 is achieved simply by first advancing the cutting head 19 and then retracting it, without changing the direction of rotation. | The invention concerns a pipe assembly and a method of constructing it. The assembly comprises an inner pipe 2 and a tubular outer skin 8 which includes polymer material. Settable insulation material 4 is introduced between the inner pipe and the outer skin. In accordance with the invention an interior of the surface is shaped to provide a mechanical key, so that following setting of the insulation material it forms an insulating layer around the inner pipe which is mechanically keyed to the interior surface of the outer skin. | 5 |
FIELD OF THE INVENTION
This invention relates to a semiconductor fabrication technology and, more particularly, to a growing system for growing a thin film over a semiconductor wafer and a process for fabricating a semiconductor device using the same.
DESCRIPTION OF THE RELATED ART
While a manufacturer is fabricating an integrated circuit on a semiconductor wafer, various kinds of material are sequentially grown on the semiconductor wafer, and the thin layers are patterned into inter-level insulating layers with contact holes and conductive strips for electric signals. One of the technical goals of the thin film growth is uniformity of thickness over the semiconductor wafer.
An atmospheric pressure chemical vapor deposition system is a typical example of the thin film growing apparatus. The atmospheric pressure chemical vapor deposition system has a reactor, and a reaction chamber is formed inside the reactor. A belt conveyer is provided in the reaction chamber, and semiconductor wafers are placed on the belt conveyer. A heater is provided under the belt conveyer, and heats the semiconductor wafers on the belt conveyer. While the semiconductor wafers are passing in the reaction chamber, a gas injection unit injects reactant gases to the semiconductor wafers. The reactant gases react with one another, and material is deposited on the semiconductor wafers.
FIG. 1 illustrates the prior art atmospheric pressure chemical vapor deposition system. A conveyer belt 1 is installed in a reaction chamber 2 , and semiconductor wafers 3 a / 3 b are placed on the conveyer belt 1 at intervals. A heater is provided under the conveyer belt 1 , and maintains the semiconductor wafers at a predetermined temperature. Though not shown in FIG. 1, a suitable driving mechanism is connected to the conveyer belt 1 , and moves the semiconductor wafers 3 a / 3 b in a direction indicated by arrow AR 1 . The conveyer belt 1 is unitary, and the entire surface of the conveyer belt 1 is moved at a constant speed. For this reason, the semiconductor wafers 3 a / 3 b are stationary on the conveyer belt 1 .
A gas injection unit 4 is provided over the conveyer belt 1 , and the semiconductor wafers 3 a / 3 b passes under the gas injection unit 4 . Reactant gases are injected from the gas injection unit 4 to the semiconductor wafers 3 a / 3 b , and the reaction product is grown on the entire surfaces of the semiconductor wafers 3 a / 3 b.
However, the manufacturer encounters a problem in that the growth rate is not constant over the upper surface of the semiconductor wafer 3 a / 3 b . This is because of the fact that the temperature and the growing time are not strictly constant over the semiconductor wafer 3 a / 3 b . Although the manufacturer varies the gas injection area and the gas flow rate in the lateral direction of the conveyer belt 1 , the prior art atmospheric pressure chemical vapor deposition system can not achieve a uniform thin film over the semiconductor wafer 3 a / 3 b.
Japanese Patent Publication of Unexamined Application No. 8-203835 discloses an atmospheric pressure chemical vapor deposition system. The prior art atmospheric pressure chemical vapor deposition system includes a conveyer belt straightforwardly moved along a guide and a reactant gas injecting unit provided over the conveyer belt for injecting reactant gases to semiconductor wafers conveyed by the conveyer belt. The semiconductor wafers are not directly put on the upper surface of the conveyer belt. Plural platens are placed on the conveyer belt, and each platen has turntables and motors for driving the turntables for rotation. The semiconductor wafers are respectively put on the turntables, and are also rotated on the conveyer belt. While the semiconductor wafers are passing through a growth region under the reactant gas injection unit, the motors rotate the turn tables and, accordingly, the semiconductor wafers put thereon, and thin films are grown on the surfaces of the semiconductor wafers, respectively.
The Japanese Patent Publication of Unexamined Application insists that the thin films are constant in thickness due to the rotation. However, the platen is a complicated mechanical unit including the motor and the turntable, and creates undesirable environment around the semiconductor wafers. First, the platens do not permit the heater under the conveyer belt to directly heat the semiconductor wafers. The heater heats the platens, and the platens propagate the heat to the semiconductor wafers. As a result, the temperature on the semiconductor wafers is different, and the chemical reaction is not stable over the semiconductor wafer. Moreover, the platens on the conveyer belt serve as an obstacle against the reactant gas flow. In order to make the growth rate constant, the reactant gas composition is to be stable throughout the reacting zone over the semiconductor wafer. For this reason, the conveyer belt is usually a net of suitable meshes, and the mesh conveyer belt permits the reactant gases to pass. In other words, the mesh conveyer belt makes the reactant gases fresh in the reacting zone. If the platens are placed on the conveyer belt, the reactant gases tend to stagnate in the reacting zone, and the reactant gas composition becomes unstable. Thus, the platens on the conveyer belt disturb the chemical reaction, and it is difficult to uniformly grow the thin films on the semiconductor wafers.
Moreover, the motors and the turntables are heated to a high temperature, and a heat-resistant motor and a turntable made of heat-resistant material are expensive. For this reason, the prior art atmospheric pressure chemical vapor deposition systems are not feasible.
Other related prior arts are disclosed in Japanese Utility Model Application No. 54-50227 and Japanese Patent Publication of Unexamined Application Nos. 57-151523, 3-123025 and 8-162416. Although the present inventor does not think the prior art technologies disclosed therein to be opposed against the present invention, the prior art technologies disclosed therein are described hereinbelow.
Japanese Utility Model Application No. 54-50227 discloses a conveying apparatus used for transferring semiconductor wafers to the next stage. The conveying apparatus disclosed in the Japanese Utility Model Application includes two rubber belts extending in parallel for conveying semiconductor wafers to the next treatment system, and the two rubber belts are independently driven at different speeds. As well known, a semiconductor wafer has a straight edge called as “orientation flat”. A detector monitors the semiconductor wafers on the two rubber belts to see whether the straight edge is oriented to a predetermined direction or not. If the straight edge is not oriented to the predetermined direction, the two rubber belts are moved at different speeds so as to rotate the semiconductor wafer until the predetermined direction. On the other hand, when the straight edge is oriented to the predetermined direction, the two rubber belts are moved at same speed, and the prior art conveying apparatus keeps the attitude of the semiconductor wafer on the two rubber belts.
The prior art conveying apparatus independently changes the moving speeds of the rubber belts, and the rubber belts moved at different speeds give rise to a rotation of the semiconductor wafer. However, the prior art conveying apparatus is available for a transfer from an apparatus to the next apparatus, and the relative moving speed between the rubber belts is changed for the attitude control. In other words, the Japanese Utility Model Application does not teach nor suggests a continuous rotation of all the semiconductor wafer in the reacting zone.
Japanese Patent Publication of Unexamined Application No. 57-151523 discloses a conveying apparatus for disk-shaped members. The prior art conveying apparatus disclosed in the Japanese Patent Publication of Unexamined Application also aims at attitude control for a disk-shaped member. The prior art conveying apparatus includes two straight-forwarded conveyers moved at different speeds and a guide member extending along the straight-forwarded conveyers. The disk-shaped member has a protrusion radially projecting from the periphery of the disk-shaped member, and is placed on the two straight-forwarded conveyers.
The two straight-forwarded conveyers are moved at different speeds, and the relative speed gives rise to a rotation of the disk-shaped member on the two conveyers. The protrusion is brought into contact with the guide member, and the disk-shaped member stops the rotation on the conveyers. Finally, all the disk-shaped members are regulated to the same attitude on the conveyers, and reach the terminal end of the conveying apparatus.
Although the prior art conveying apparatus gives rise to the rotation of the disk-shaped members, the rotation aims at the attitude control. The Japanese Patent Publication of Unexamined Application does not teach any application to a semiconductor fabrication technology, nor suggests. This is clearly understandable, because the semiconductor wafer does not have any protrusion indispensable in the prior art attitude control.
Japanese Patent Publication of Unexamined Application No. 3-123025 discloses an atmospheric pressure chemical vapor deposition system. The prior art atmospheric pressure chemical vapor deposition system disclosed in the Japanese Patent Publication of Unexamined Application has a conveyer implemented by hot plates linked with one another for forming a loop. Semiconductor wafers are placed on the hot plates, and successively pass the reacting zone under a reactant gas injector.
When the hot plates change the moving direction along the loop, the hot plates p s turn, and the semiconductor wafers on the hot plates also turn. However, the reactant gas injector is placed over a straight portion of the loop, and neither hot plate nor semiconductor wafer turn under the reactant gas injector.
Japanese Patent Publication of Unexamined Application No. 8-162416 discloses an atmospheric pressure chemical vapor deposition system. The prior art atmospheric pressure chemical vapor deposition system also aims at constant growth through a relative motion between a reactant gas injector and semiconductor wafers on a conveyer belt.
The Japanese Patent Publication of Unexamined Application proposes two kinds of relative motion. The first relative motion is offered by a reciprocal motion of the reactant gas injector. The reactant gas injector is reciprocally moved in the direction perpendicular to the moving direction of the conveyer belt. The second relative motion is offered by rotating the semiconductor wafers on the conveyer belt. The Japanese Patent Publication of Unexamined Application merely teaches that turntables are provided in holes formed in the conveyer belt at intervals. The Japanese Patent Publication of Unexamined Application is silent to how the turntables are rotated in the holes. However, the turntables are causative of the undesirable environment for the stable chemical reaction inherent in the prior art atmospheric pressure chemical vapor deposition disclosed in Japanese Patent Publication of Unexamined Application No. 8-203835.
In this situation, it is impossible to motivate a person skilled in the art to combine the prior art technologies disclosed in Japanese Utility Model Application No. 54-50227 and Japanese Patent Publication of Unexamined Application No. 57-151523 with the atmospheric pressure chemical vapor deposition systems disclosed in Japanese Patent Publication of Unexamined Application Nos. 8-162416 and 8-203835, because the uniform orientation through the attitude control is not required for the relative motion between the reactant gas injector and the semiconductor wafers.
SUMMARY OF THE INVENTION
It is therefore an important object of the present invention to provide a growing system, which uniformly grows material on semiconductor wafers under stable environment.
It is also an important object of the present invention to provide a process used in the growing system.
To accomplish the object, the present invention proposes to rotate semiconductor wafers on conveyers moved at different speeds.
In accordance with one aspect of the present invention, there is provided a growing system comprising a growing means creating a growing zone for growing a material on wafers, a plurality of conveying members passing through the growing zone and transferring the wafers through the growing zone to a destination, and a controller connected to the plurality of moving members and regulating the plurality of conveying members to respective moving speeds different from one another so as to give rise to a rotation of each of the wafers on the plurality of conveying members during the transfer through the growing zone.
In accordance with another aspect of the present invention, there is provided a process for growing material on wafers comprising the steps of a) placing each of the wafers on a plurality of conveying members moved at different speeds, b) transferring the each of the wafers toward a destination so as to give rise to a rotation of the aforesaid each of the wafers on the plurality of conveying members, and c) growing the material on the aforesaid each of the wafers while the plurality of conveying members are rotating the aforesaid each of the wafers.
BRIEF DESCRIPTION OF THE DRAWINGS
The features and advantages of the growing system and the process will be more clearly understood from the following description taken in conjunction with the accompanying drawings in which:
FIG. 1 is a schematic perspective view showing the prior art atmospheric pressure chemical vapor deposition system;
FIG. 2 is a schematic perspective view showing an atmospheric pressure chemical vapor deposition system according to the present invention; and
FIG. 3 is a schematic view showing a rotation of a semiconductor wafer on a conveyer incorporated in the atmospheric pressure chemical vapor deposition system shown in FIG. 1 .
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 2 of the drawings, an atmospheric pressure chemical vapor deposition system embodying the present invention comprises a reactor 11 , and a reaction chamber 11 a is defined in the reactor 11 . Reacting zone is produced in the reaction chamber 11 a as will be described hereinlater.
The atmospheric pressure chemical vapor deposition system further comprises a conveyer 12 , a reactant gas injector 13 and a heater 14 . The reactant gas injector 13 injects reactant gases to the conveyer 12 , and produces the reacting zone over the conveyer 12 . The reactant gases produce a predetermined material in the reacting zone. The predetermined material may be a kind of semiconductor, conductive material or dielectric material such as, for example, silicon dioxide, phosphosilicate glass or boro-phosphosilicate glass.
Semiconductor wafers 15 a / 15 b are placed on the conveyer 12 , and the conveyer 12 transfers the semiconductor wafers 15 a / 15 b through the reacting zone to a terminal end. The heater 14 is placed under the conveyer 12 , and radiates heat through the conveyer 12 to the semiconductor wafers 15 a / 15 b . The semiconductor wafers 15 a / 15 b rise to a target temperature, and the chemical reaction is promoted in the reacting zone. While the semiconductor wafers 15 a / 15 b are passing through the reacting zone, the predetermined material is deposited on the semiconductor wafers 15 a / 15 b , and is grown to a layer over the semiconductor wafers 15 a / 15 b.
The conveyer 12 includes plural conveyer belts 12 a / 12 b / 12 c / 12 d / 12 e / 12 f / 12 g made from a net of suitable meshes and a driving mechanism 12 h for driving the conveyer belts 12 a to 12 g . The conveyer belts 12 a to 12 g are formed into loops, and are stretched between driving shafts (not shown). The driving mechanism 12 h rotates the conveyer belts 12 a to 12 g at different speeds, and, accordingly, the conveyer belts 12 a to 12 g are moved at different speeds Va, Vb, Vc, Vd, Ve, Vf and Vg. In this instance, the driving mechanism 12 h regulates the conveyer belts 12 a / 12 b / 12 c / 12 d / 12 e / 12 f / 12 g to Va>Vb>Vc>Vd>Ve>Vf>Vg. Thus, the driving mechanism 12 h produces a relative speed between the conveyer belts 12 a to 12 g , and the relative speed gives rise to a rotation R of the semiconductor wafer 15 a / 15 b on the conveyer belts 12 a to 12 g as shown in FIG. 3 . In this instance, the conveyer belts rotates the semiconductor wafers 15 a / 15 b in the clockwise direction. The semiconductor wafer 15 a / 15 b is moved from P 1 through P 2 and P 3 to P 4 , and changes the attitude on the conveyer belts 12 a to 12 g through the rotation R. The semiconductor wafers 15 a / 15 b are rotated in the reacting zone, and the predetermined material is uniformly grown over the semiconductor wafers 15 a / 15 b.
Turning back to FIG. 2, the reactant gas injector 13 includes a reactant gas source 13 a and an injection unit 13 b . The reactant gas source 13 a is connected through a gas pipe 13 c to the injection unit 13 b , and an opening 13 d is formed in the lower plate of the injection unit 13 b . The opening 13 d is laterally elongated, and is wider than the diameter of the semiconductor wafer 15 a / 15 b . The reactant gases are downwardly injected from the opening 13 d , and create the reacting zone over the semiconductor wafer 15 a / 15 b . The injected reactant gases pass the meshed conveyer belts 12 a to 12 g , and fresh reactant gases form the reacting zone at all times.
Even if the reacting conditions are different at reacting sub-zones of the reacting zone, the rotating semiconductor wafer 15 a / 15 b exposes the entire surface to the reacting sub-zones, and the growing rate is averaged over the entire surface of the semiconductor wafer 15 a / 15 b . As a result, the layer of predetermined material has a thickness over the entire surface.
The heater 14 includes a heat generating unit 14 a placed under the conveyer belts 12 a to 12 g and an electric power source 14 b connected to the heat generating unit 14 a . The electric power source 14 b energizes the heat generating unit 14 a , and heat generating unit 14 a radiates heat through the meshed conveyer belts 12 a to 12 g . As a result, the semiconductor wafers 15 a / 15 b surely rises to the target temperature.
In operation, the semiconductor wafers 15 a / 15 b are placed on the conveyer belts 12 a to 12 g at intervals, and proceeds through the reacting zone to the terminal end of the conveyer belts 12 a to 12 g . The heat generating unit 14 a heats the semiconductor wafers 15 a / 15 b to the target temperature, and the injection unit 13 b flows the fresh reactant gases through the reacting zone. While the semiconductor wafers 15 a / 15 b are proceeding toward the terminal end, the conveyer belts 12 a to 12 g give rise to the rotation R of the semiconductor wafer 15 a / 15 b due to the relative speed, and the rotating semiconductor wafer 15 a / 15 b uniformly exposes the entire surface to the reaction product or the predetermined material in the reacting sub-zones. As a result, the growth rate of the predetermined material is averaged, and the predetermined material is grown to a constant thickness over the semiconductor wafers 15 a / 15 b.
In this instance, the reactant gas injector 13 serves as a growing means, and the conveyer belts 12 a to 12 g as a plurality of conveying members. The driving mechanism 12 h is corresponding to a controller.
As will be appreciated from the foregoing description, the conveyer belts 12 a to 12 g are moved at the different speeds Va to Vg, and give rise to the rotation of the semiconductor wafer 15 a / 15 b in the reacting zone. As a result, the growth rate is averaged, and the predetermined material is grown to a constant thickness over the semiconductor wafers 15 a / 15 b.
The relative speed is given by the driving mechanism 12 h , and any obstacle against the heat and the gas flow is not placed on the conveyer belts 12 a to 12 g . For this reason, the reacting conditions are rather uniform in the reacting zone, and the layer of predetermined material is grown to the target thickness more strictly than that of the prior arts.
Moreover, the driving mechanism 12 h is not exposed to the heat, and a standard motor and standard mechanical elements are available for the driving mechanism 12 h . For this reason, the driving mechanism 12 h is more economical than the platens of the prior arts.
Although a particular embodiment of the present invention has been shown and described, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the present invention.
For example, the driving mechanism may increase the moving speed in a different order from that of the preferred embodiment in so far as the conveyer belts give rise to a rotation of the semiconductor wafer.
The present invention may be applied to another kind of growing system.
In order to drive the conveyer belts at different speeds, the driving mechanism may include electric motors respectively associated with the conveyer belts and a controller for regulating the electric motors to respective target speeds. Otherwise, the driving mechanism may have only one electric motor and sprockets different in number of teeth. The sprockets are fixed to a single shaft driven by the electric motor, and the driving force is transferred from the sprockets through chains to respective sprockets fixed to the shafts for the conveyer belts.
In the above-described embodiment, the seven conveyer belts are arranged in parallel. The number of conveyer belts is changeable depending upon the semiconductor wafer size and/ or the space available for the conveyer 12 . | An atmospheric pressure chemical vapor deposition system includes plural meshed conveyer belts extending in parallel for transferring semiconductor wafers at intervals, a reactant gas injector located over the plural meshed conveyer belts for creating reacting zone over the conveyer belts and a driving mechanism for moving the plural conveyer belts, wherein the driving mechanism moves the conveyer belts at different speeds so as to give rise to a rotation of each semiconductor wafer in the reacting zone, thereby uniformly exposing the entire surface of the semiconductor wafer to the reactant gases, which creates the depositing conditions different in the reacting zone. | 8 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to a media jam and media bent corner detector, comprising: a carriage; a transducer operatively connected to or adjacent to the carriage; and a piezoelectric film beam operatively connected to the transducer such that a portion of the beam substantially extends into a media path to detect the presence of a media jam or a media bent corner.
[0003] 2. Description of the Related Art
[0004] In a high reliability, high speed printing mechanism, it is critical to know if media is jamming up against or under the print heads or if a bent over corner is likely to contact the underside of the print heads. In a paper jam condition, multiple sheets will pile up quickly, making it hard to clear the jam. Also, if the mechanism continues to try to move for media along, it will often shift the print head positions, thereby causing subsequent color printing alignment problems. Bent over corners may cause a problem because they may extend above the paper support surface enough to make contact with the print head nozzles. This could lead to the transfer of objectionable amounts of ink/toner from a print head onto the media which may then carry and transfer the ink/toner onto the next print head. This may then cause a mixing of ink types that could lead to a chemical reaction that clogs the print head. With this in mind, it is known that space and tolerance constraints make it difficult to provide a reliable but inexpensive sensor that can detect a bent piece of media or the beginning of a media jam. Consequently, a more advantageous sensor, then, would be provided if it was reliable and inexpensive and could detect a bent piece of media and/or the beginning of the media jam.
[0005] It is apparent from the above that there exists a need in the art for a sensor that is reliable and inexpensive, but which at the same time can detect a bent piece of media and/or the beginning of the media jam. It is a purpose of this invention to fulfill this and other needs in the art in a manner more apparent to the skilled artisan once given the following disclosure.
SUMMARY OF THE INVENTION
[0006] Generally speaking, an embodiment of this invention fulfills these needs by providing a media jam and media bent corner detector, comprising: a carriage; a transducer operatively connected to or adjacent to the carriage; and a piezoelectric film beam operatively connected to the transducer such that a portion of the beam substantially extends into a media path to detect the presence of a media jam or a media bent corner.
[0007] In certain preferred embodiments, the transducer is further comprised of a printed circuit assembly. Also, the piezoelectric film beam is further comprised of a polyvinylidene fluoride (PVDF) piezoelectric film beam. Finally, the detector further comprises isolation grommets and a heavy bracket to prevent high frequency vibrations and shock from being transferred from the carriage to the detector.
[0008] In another further preferred embodiment, a reliable and inexpensive detector is presented which can detect a bent piece of media and/or the beginning of the media jam.
[0009] The preferred media jam and media bent corner detector, according to various embodiments of the present invention, offers the following advantages: ease-of-use; excellent media jam detecting characteristics; excellent media bent corner detection characteristics; lightness in weight; improved reliability; and reduced cost. In fact, in many of the preferred embodiments, these factors of media jam detecting characteristics, media bent corner detection characteristics, reliability, and cost are optimized to an extent that is considerably higher than heretofore achieved in prior, known media jam and media bent corner detectors.
[0010] The above and other features of the present invention, which will become more apparent as the description proceeds, are best understood by considering the following detailed description in conjunction with the accompanying drawings, wherein like characters represent like parts throughout the several views and in which:
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 illustrates a media jam and media bent corner detector assembly, according to one embodiment of the present invention;
[0012] FIG. 2 illustrates the media jam and media bent corner detector assembly with the grommets and bracket attached, according to another embodiment of the present invention;
[0013] FIG. 3 shows how a piece of media that is jammed interacts with the media jam and media bent corner detector assembly, according to another embodiment of the present invention;
[0014] FIG. 4 is a flowchart of a method for interrupting a print job when a media jam or media bent corner has been detected, according to another embodiment of the present invention;
[0015] FIG. 5 is a flowchart of another method for interrupting a print job when a media jam or media bent corner has been detected, according to another embodiment of the present invention
[0016] FIG. 6 is a flowchart of a method for moving the carriage to a service/capping mode when a media jam or media bent corner has been detected, according to another embodiment of the present invention; and
[0017] FIG. 7 is a flowchart of a method for determining if a media jam or media bent corner has been detected, according to another embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0018] With reference first to FIG. 1 , there is illustrated one preferred embodiment for use of the concepts of this invention. FIG. 1 illustrates media jam or media bent corner detector assembly 2 . Assembly 2 includes, in part, carriage 4 , transducer 6 , and piezoelectric film beam 8 . Transducer 6 , preferably, is constructed of a printed circuit assembly (PCA) that is rigidly attached to carriage 4 . Piezoelectric film beam 8 , preferably, is constructed of a polyvinylidene fluoride (PVDF) piezoelectric film beam that is rigidly attached along one end to transducer 6 such that a portion of piezoelectric film beam 8 extends below transducer 6 and into a media path. It is to be understood that piezoelectric film beam 8 should extend at least across the entire width of the media to be measured. It is also to be understood that transducer 6 and piezoelectric film beam 8 can be located away from the carriage 4 .
[0019] With respect to FIG. 2 , bracket 20 is placed over piezoelectric film beam 8 and secured by isolation grommets 22 to prevent high frequency vibrations and shock from being transferred from carriage 4 to assembly 2 . Bracket 20 , preferably, is constructed of any suitable, durable, high strength material that is capable of retaining transducer 6 and piezoelectric film beam 8 in place. Isolation grommets 22 are used to secure bracket 20 onto carriage 4 . As can be seen in FIG. 2 , a portion of piezoelectric film beam 8 extends below carriage 4 and bracket 20 .
[0020] With respect to FIG. 3 , under normal circumstances media 32 passes below piezoelectric film beam 8 . However, if a sheet of media 32 becomes jammed, typically a portion 34 of the media 32 extends above drum 30 . When portion 34 extends above drum 30 , portion 34 contacts piezoelectric film beam 8 . This contact with piezoelectric film beam 8 causes piezoelectric film beam 8 to bend or deform. This bending strains transducer 6 and generates an electric charge that is amplified and thresholded to generate a firmware interrupt within a driving circuit (not shown) for driving drum 30 . The firmware interrupt is used to determine the presence of a media jam or media bent corner. It is to be understood that while a media jam has been shown in FIG. 3 , a media bent corner would also extend above the drum 30 , contact piezoelectric film beam 8 and cause piezoelectric film beam 8 to deform.
[0021] Various usages of assembly 2 will now be described. With respect to FIG. 4 , a method 40 for interrupting a print job when a media jam or media bent corner has been detected is shown. Method 40 includes, but is not limited to, the steps of actuating assembly 2 ( FIG. 1 ) when a media jam or a media bent corner contacts piezoelectric film beam 8 ( FIG. 3 ) (step 42 ). Stopping the rotation of drum 30 ( FIG. 2 ) by the firmware interrupt (step 44 ). Finally, the media jam or the media having a bent corner is removed (step 46 ). It is to be understood that a variety of conventional techniques can be employed to assist the user in removing the media jam or the bent corner media. For example, lights can be illuminated to show where the jam/bent corner media is located. Also, graphics on the user interface can show where the jam/bent corner media is located. It is to be understood that the actuating steps 42 - 72 in methods 40 - 70 , respectively, can be further utilized to determine if the jam/bent corner media has been cleared.
[0022] With respect to FIG. 5 , another method 50 for interrupting a print job when a media jam or media bent corner has been detected is shown. Method 50 includes, but is not limited to, the steps of actuating assembly 2 ( FIG. 1 ) when a media jam or a media bent corner contacts piezoelectric film beam 8 ( FIG. 3 ) (step 52 ). Stopping the rotation of drum 30 ( FIG. 2 ) by the firmware interrupt (step 54 ). Reversing the rotation of drum 30 to allow for the removal of the media jam or the media having a bent corner (step 56 ). It is to be understood that the flow of the media path can be conventionally reversed to allow for the removal of the media jam or the media having a bent corner. Finally, the media jam or the media having a bent corner is removed (step 58 ).
[0023] With respect to FIG. 6 , a method 60 for moving the carriage to a service/capping mode when a media jam or media bent corner has been detected is shown. Method 60 includes, but is not limited to, the steps of actuating assembly 2 ( FIG. 1 ) when a media jam or a media bent corner contacts piezoelectric film beam 8 ( FIG. 3 ) (step 62 ). Stopping the rotation of drum 30 ( FIG. 2 ) by the firmware interrupt (step 64 ). Moving the carriage 4 to a servicing/capping mode such that the print head can be conventionally serviced and/or capped (step 66 ). The print head is then conventionally serviced and/or capped. Finally, the media jam or the media having a bent corner is removed (step 68 ).
[0024] With respect to FIG. 7 , a method 70 for determining if a media jam or media bent corner has been detected is shown. Method 70 includes, but is not limited to, the steps of actuating assembly 2 ( FIG. 1 ) when a media jam or a media bent corner contacts piezoelectric film beam 8 ( FIG. 3 ) (step 72 ). Stopping the rotation of drum 30 ( FIG. 2 ) by the firmware interrupt (step 74 ). Determining if media is present in the device (step 76 ). If media is present in the device then the media jam or media having the bent corner is removed (step 78 ). However, if media is not present in the device, the assembly 2 is checked for defects (step 79 ). One of the purposes of method 70 is to detect if carriage 4 is creating high frequency vibrations or shock and transferring these to assembly 2 . Even though media may not be present in assembly 2 , a false reading may still result from the vibrations or shock as carriage 4 shuttles back and forth. In this instance, carriage 4 may need to be serviced or replaced.
[0025] It is to be understood that the flowchart of FIGS. 4-7 show the architecture, functionality, and operation of one implementation of the present invention. If embodied in software, each block may represent a module, segment, or portion of code that comprises one or more executable instructions to implement the specified logical function(s). If embodied in hardware, each block may represent a circuit or a number of interconnected circuits to implement the specified logical function(s).
[0026] Also, the present invention can be embodied in any computer-readable medium for use by or in connection with an instruction-execution system, apparatus or device such as a computer/processor based system, processor-containing system or other system that can fetch the instructions from the instruction-execution system, apparatus or device, and execute the instructions contained therein. In the context of this disclosure, a “computer-readable medium” can be any means that can store, communicate, propagate or transport a program for use by or in connection with the instruction-execution system, apparatus or device. The computer-readable medium can comprise any one of many physical media such as, for example, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor media. More specific examples of a suitable computer-readable medium would include, but are not limited to, a portable magnetic computer diskette such as floppy diskettes or hard drives, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory, or a portable compact disc. It is to be understood that the computer-readable medium could even be paper or another suitable medium upon which the program is printed, as the program can be electronically captured, via, for instance, optical scanning of the paper or other medium, then compiled, interpreted or otherwise processed in a single manner, if necessary, and then stored in a computer memory.
[0027] Those skilled in the art will understand that various embodiment of the present invention can be implemented in hardware, software, firmware or combinations thereof. Separate embodiments of the present invention can be implemented using a combination of hardware and software or firmware that is stored in memory and executed by a suitable instruction-execution system. If implemented solely in hardware, as in an alternative embodiment, the present invention can be separately implemented with any or a combination of technologies which are well known in the art (for example, discrete-logic circuits, application-specific integrated circuits (ASICs), programmable-gate arrays (PGAs), field-programmable gate arrays (FPGAs), and/or other later developed technologies. In preferred embodiments, the present invention can be implemented in a combination of software and data executed and stored under the control of a computing device.
[0028] It will be well understood by one having ordinary skill in the art, after having become familiar with the teachings of the present invention, that software applications may be written in a number of programming languages now known or later developed.
[0029] Although the flowcharts of FIGS. 4-7 show a specific order of execution, the order of execution may differ from that which is depicted. For example, the order of execution of two or more blocks may be scrambled relative to the order shown. Also, two or more blocks shown in succession in FIGS. 4-7 may be executed concurrently or with partial concurrence. All such variations are within the scope of the present invention.
[0030] Once given the above disclosure, many other features, modifications or improvements will become apparent to the skilled artisan. Such features, modifications or improvements are, therefore, considered to be a part of this invention, the scope of which is to be determined by the following claims. | This invention relates to a media jam and media bent corner detector, comprising: a carriage; a transducer operatively connected to or adjacent to the carriage; and a piezoelectric film beam operatively connected to the transducer such that a portion of the beam substantially extends into a media path to detect the presence of a media jam or a media bent corner. | 6 |
BACKGROUND OF THE INVENTION
This is a Division of application Ser. No. 29,122 filed Apr. 11, 1979, now U.S. Pat. No. 4,264,509 which in turn, is a continuation-in-part of application Ser. No. 804,594 filed June 8, 1977 now U.S. Pat. No. 4,157,984.
Many food products containing and including edible fats and oils, i.e., fats and oils of animal and vegetable origin or modified fats and oils of animal and vegetable origin, become rancid or have an undesirable taste and/or color imparted thereto during storage, especially upon exposure to or on contact with oxygen. A number of chemical compounds have been employed for avoiding or reducing these effects so that food products containing fats or oils may be kept for longer periods of time, but such agents have not been entirely satisfactory or effective in many cases. Furthermore, such chemical compounds are usually synthetic chemical products not derived from or identical with material of natural food classifications and, as a consequence, there has been some question as to the advisability of using such compounds in food compositions.
Principal antioxidants of the above kinds heretofore employed included BHA (butylated hydroxyanisole), BHT (butylated hydroxytoluene) and TBHQ (tertiary butylhydroquinone), as well as some other chemicals of which one example is propyl gallate (PG). While these materials have been quite effective in animal fats, such as lard, they are much less useful in some other applications. Their volatility and tendency to decompose at high temperatures makes them not entirely suitable for deep fat fried foods. Indeed, their usefulness for stability of vegetable oils is less than satisfactory. For example, they are not entirely effective in protecting against off-flavor development, such as the so-called reversion flavor, that occurs, with passage of time, in soybean oil. For these and other reasons, there has been a need for improvement in the field of antioxidants, especially those to be used with food materials that comprise or consist of fats or oils.
It has been heretofore known that antioxidant properties are possessed by tempeh, a fermented soybean product obtained by fermenting soybeans with a fungus, either Rhizopus oligosporus or Rhizopus oryzae. Food products containing tempeh, such as fish or fatty meat products exhibit improved stability, see U.S. Pat. No. 3,681,085 (1972). Further, it has heretofore been found that by extracting tempeh with a mixture of hexane and methanol, a component of tempeh, namely oil of tempeh, can be recovered, see U.S. Pat. Nos. 3,762,933 (1973) and 3,885,256 (1974), which exhibits enhanced antioxidant properties relative to those of tempeh. This oil of tempeh has been found to be useful in stabilizing a wide variety of edible oils and fats.
SUMMARY OF THE INVENTION
The present invention involves the discovery that numerous isoflavones and related compounds which possess antioxidant properties may be recovered from tempeh. Other compounds which also are useful as antioxidants and/or as components of antioxidant compositions can be prepared by chemical modification of those recovered from tempeh. Additionally, all of the compounds can be chemically synthesized. The compounds of this invention have the structure: ##STR1## wherein the dashed lines may be carbon-carbon single bonds or carbon-carbon double bonds, and wherein X may be two hydrogen atoms or oxygen, and further wherein each of R, R' and R" may be a methyl or ethyl group or hydrogen.
These compounds possess antioxidant properties and may be utilized in the stabilization of a wide variety of food products including edible fats and oils.
Of these compounds those having the structure ##STR2## may be recovered from tempeh either individually or as components of a mixture.
Of the compounds so recovered certain are known compounds, such as for example, texasin (6,7-dihydroxy-4'-methoxyisoflavone), genistein (5,7,4'-trihydroxyisoflavone), daidzein (7,4'-dihydroxyisoflavone), glycitein (6 methoxy-7,4'-dihydroxyisoflavone), and the so-called "Murata" compound (6,7,4'-trihydroxyisoflavone). However, the fact that these compounds possess antioxidant properties is a new discovery. Of these compounds, texasin has been found to be a particularly effective antioxidant.
Also, certain compounds having the structure ##STR3## may be recovered from tempeh in minor amounts. However, these compounds are obtained in higher yield upon chemical modification, specifically hydrogenation, of compounds II. Of the compounds III, the compound having the structure ##STR4## has been found to be particularly effective. All of the compounds III are novel.
Compounds having the structure ##STR5## may be prepared by hydrogenation of Compounds IV. Of these, the compound having the structure ##STR6## is the most effective of the antioxidants which have been evaluated. All of the Compounds V are also novel.
These Compounds I through VI may be chemically synthesized as well as recovered from tempeh. Thus, in addition to providing compounds useful as antioxidants and in antioxidant compositions, the present invention provides methods of preparing and/or recovering the compounds disclosed.
It is therefore a primary object of the present invention to provide compounds useful as antioxidants.
It is a related object to provide antioxidant compositions which include these compounds.
It is a further related object to provide edible oils, fats and other food products which include these antioxidant compositions.
It is another object of this invention to provide methods of stabilizing edible oils, fats or foods by including in such oils, fats or foods an effective amount of an antioxidant composition.
It is a final object to provide methods of recovering and/or preparing compounds useful as antioxidants.
How these and other objects of this invention are accomplished will become apparant upon reading the detailed description of the invention including the examples set forth, and the claims which follow. In at least one embodiment of the present invention at least one of the foregoing objects will be achieved.
DETAILED DESCRIPTION OF THE INVENTION
In accordance with one embodiment of this invention, isoflavones having the structure ##STR7## wherein the dashed lines may be carbon-carbon single bonds or carbon-carbon double bonds, and wherein X may be two hydrogen atoms or oxygen, and further wherein R, R' and R" may be a methyl or ethyl group or hydrogen have been found to be useul as antioxidants and as components of antioxidant compositions.
Certain of these compounds, namely those having the structure ##STR8## are natural products which may be recovered from tempeh, an Indonesian foodstuff, by fermentation of soybeans with a fungus, e.g. either Rhizopus oligosporus ATCC No. 22959 or Rhizopus oryzae ATCC No. 9363. Compounds II are typically present as a mixture in tempeh and are most readily recovered therefrom in the form of a mixture from which the individual compounds can subsequently be isolated.
Compounds encompassed within Structure II as well as within the other structures herein may include stereoisomers and optical isomers. For purposes of this disclosure, no distinction will be made among such isomers so that it is to be understood that the disclosure and claims set forth hereinafter embrace all of the isomers encompassed within the structural formulas indicated. Certain of Compounds II are known compounds, such as for example, texasin (6,7-dihydroxy-4'-methoxyisoflavone), genistein (5,7,4'-trihydroxy isoflavone), daidzein (7,4'-dihydroxyisoflavone), glycitein (6 methoxy-7,4'-dihydroxyisoflavone), and the so-called "Murata" compound (6,7,4'-trihydroxyisoflavone). However, in accordance with the present invention it has been discovered that these compounds possess antioxidant properties. Of these compounds, texasin, which has the structure ##STR9## has been found to be a particularly effective antioxidant.
In addition to Compounds II, additional compounds having the structure ##STR10## are present in tempeh in minor amounts and may be recovered therefrom. However, these compounds are obtained in higher yeild upon chemical modification, specifically, hydrogenation, of Compounds II. Of the Compounds III, the compound produced by hydrogenation of texasin, namely, 6,7-dihydroxy-3-(4-methoxyphenyl)chromanon-4, having the structure ##STR11## has been found to be particularly effective. Compounds III are novel compounds useful as antioxidants and as components of antioxidant compositions.
Finally, novel compounds having the structure ##STR12## may be prepared by hydrogenation of Compounds III. Of these, the compound, 6,7-dihydroxy-3-(4-methoxyphenyl) chroman having the structure ##STR13## is the most effective of the antioxidants which have been evaluated.
In accordance with another embodiment of this invention, antioxidant compositions may be prepared which include one or more of Compounds I and a suitable carrier. Furthermore, antioxidant compositions which include one or more of Compounds III and/or V provide exceptional antioxidative properties as set forth in the examples hereinafter. Suitable carriers include essentially all non-toxic substances with which the compounds may be admixed or in which they may be dissolved and/or suspended. When the antioxidant composition is intended for use in the stabilization of oils and fats and carrier may be the same or another compatible oil or fat. The amount of the compound or compounds present in the composition may vary within a wide range limited only by the requirement that the amount be effective to provide antioxidant properties to the composition. Typically, amounts will range from about 0.001 to 10 percent by weight.
Stabilized edible fat or oil compositions may be prepared by adding thereto an antioxidant composition which includes one or more of compounds I in an amount effective to stabilize such edible fat or oil. Effective amounts of such antioxidant compositions for improving the stability of oils or fats such as for example, lard, corn oil, olive oil, bean oil, safflower oil, vegetable oil, cottonseed oil, polyunsaturated oils, animal fats or oils and the like are amounts in the range of about 0.01 to 1.0 percent by weight, more or less.
Such antioxidant compositions can also be included in food products to produce stabilized food compositions. Accordingly, food products, such as fish, fatty meat or derivatives thereof, may be stabilized by the addition thereto of an effective amount of an antioxidant composition such as described hereinabove. Effective amounts may typically range from 0.001 to 10 percent by weight, preferably 0.01 to 1.0 percent.
As indicated hereinabove, Compounds II and certain of Compounds III are produced by fermentation of soybeans with a fungus, e.g., R. oligosporus or R. oryzae. Compounds II may then be recovered in the following manner. Dry, e.g. lyophilized, tempeh powder or cultured fungus is contacted with a 60-70% aqueous methanol solution for an extended period of time, for example, overnight, at a temperature of about 4° C. thereby producing an extract of methanol-soluble components including one or more of the isoflavones II. The methanol extract solution, after removal of insoluble material, is evaporated to dryness, preferably in vacuo, at an elevated temperature, for example, about 40°-60° C. A solid residue is produced most of which is redissolved upon contact with dry methanol. That portion of the residue which is methanol insoluble is separated from the soluble components by centrifugation and discarded. After centrifugation, the methanol supernatant is extracted with haxane several times, for example, two to three times, in order to remove any traces of hexane-soluble impurities, such as lipids. After discarding the resulting hexane extract, the remaining methanol supernatant is evaporated to reduce its volume to a minimal fraction, for example, about 20 ml, and kept at a temperature of about -20° C. for about 15-20 minutes. This results in formation of additional precipitate which is removed and discarded.
The isoflavones may then be recovered from the methanol supernatant or extract as follows. The supernatant is subjected to molecular sieve chromatography, for example, chromatography on Sephadex LH20 using a suitable size column, for example 2×40 cm, and a suitable mobile phase, for example, n-propanol: ethylacetate:water in a ratio 5:5:1. One of the fractions resulting from this chromatographic separation is fluorescent with emission in the blue range of the visible spectrum. This blue fluorescent fraction is separated and subjected to adsorption chromatography on a suitable matrix, for example, silica gel, using an appropriate mobile phase, e.g. ethylacetate:propanol:water=95:2:3. The resulting blue fluorescent fraction is then rechromatographed on an adsorptive matrix, e.g. thin layer chromatography on silica gel, employing a different mobile phase, e.g. cyclohexane:dichloromethane:ethylformate:formic acid=35:30:30:5. Each of the isoflavones can then be recovered in essentially pure form using its differential mobility on the silica gel plate.
Alternatively, Compounds II can be chemically synthesized by forming a suspension of a compound having the structure ##STR14## wherein each of R and R' may be either hydrogen or an ethyl or methyl group and a compound having the structure ##STR15## wherein R" may be hydrogen, methyl or ethyl in dry ethylether containing zinc chloride. This suspension is then exposed to dry hydrogen chloride for a sufficient time to form an oily product. The suspension is next maintained at an appropriate temperature for a sufficient time to permit the oil product formed upon exposure to dry hydrogen chloride to separate from the suspension. The supernatant remaining after separation of the oil product from the suspension is removed and discarded. Next, a major amount of water and a minor amount of concentrated hydrochloric acid is added to the oil product to form a mixture, the mixture is boiled under reflux for a sufficient time to produce a precipitate product having the structure ##STR16##
After recovering this precipitate, it is dissolved in a suitable solvent, borontrifluoride-methyletherate added, the temperature adjusted to about 50° C., methanesulphonyl chloride added as a solution, and then the resulting solution heated to about 90°-100° C. for a sufficient time to permit the reaction to proceed substantially to completion. Finally, Compound II is recovered.
Compounds III can be prepared by hydrogenating Compounds II using conventional techniques such as contact with hydrogen gas in the presence of a catalyst under appropriate conditions of temperature, pressure and the like. Similarly, Compounds V can be prepared by hydrogenating Compounds III and/or II.
The following examples are set forth to illustrate the practices of the present invention but are not intended in any way to limit or otherwise restrict the scope thereof as set forth in the preceding description or in the claims which follow.
EXAMPLE I
The compounds 6,7-dihydroxy-3-(4-methoxyphenyl)chromanon-(4) and 6,7-dihydroxy-3(4-methoxyphenyl)chroman were evaluated as antoxidants using an automated version of the Swift stability test at 100° C. For a more detailed description of the Swift stability test see A.O.C.S. Tentative Method Cd 12-57 (revised 1959. For the test the lard was heated to 100° C. and air bubbled through at 2 ml/minutes. Every few hours the oil was analyzed for peroxide value using the peroxide value test, A.O.C.S. Official Method Cd8-53 (1960). The tests were carried out using two different batches of lard. The results of the tests are shown in Table I.
TABLE I______________________________________AUTOMATED SWIFT STABILITY ON LARDEnd of Induction Period in Hours CONCENTRATION OF ANTIOXIDANT 25 50 100 200BATCH ANTIOXIDANT mg/kg mg/kg mg/kg mg/kg______________________________________A 6,7-dihydroxy- 3-(4-methoxy- phenyl)chroman 50 62 6,7-dihydroxy- 3-(4-methoxy- phenyl)chromanon-4 33 38 BHA 26 32.5 BHT 27 29 TBHQ 32 42 α-tocopherol (Vitamin E) 21 21Blank ←2.5→B 6,7-dihydroxy- 3-(4-methoxy- phenyl)chroman 26 43 92 110 6,7-dihydroxy- 3-(4-methoxy- phenyl)chroma- non-4 15 22 45 62 BHA 10 30 49 57Blank ←6.5→______________________________________
According to the results obtained, 6,7-dihydroxy-3-(4-methoxyphenyl)chroman is the most effective of the antioxidants tested. 6,7-dihydroxy-3-(4-methoxyphenyl)chromanon-4 is better than α-tocopherol, but less effective than TBHQ and comparable with BHA and BHT.
EXAMPLE 2
The Swift stability test described for lard in Example 1 was repeated with palm oil and bean oil. The results again indicated that 6,7-dihydroxy-3-(4-methoxyphenyl)chroman is the most effective of the antioxidants. 6,7-dihydroxy-3-(4-methoxylphenyl)chromanon-4 was better than α-tocopherol, but less effective than TBHQ and comparable with BHA and BHT.
EXAMPLE 3
The compounds tested in Example 1, namely, 6,7-dihydroxy-3-(4-methoxyphenyl)chroman and 6,7-dihydroxy-3-(4-methoxyphenyl)chromanon-4, were also tested to evaluate their effect upon the taste of normal quality lard, bean oil and palm oil. The compounds were added to the lard or oil at amounts ranging from 25-200 mg/kg and stored at 15° C. or 50° C. in the dark. The lard or oil was then tasted periodically over a 14-week period. It was found that 6,7-dihydroxy-3-(4-methoxyphenyl)chromanon-4 favorably influenced the taste of the lard and oils. Addition of 6,7-dihydroxy-3-(4-methoxyphenyl)chroman imparted an off-taste although this may be due to the presence of an impurity.
EXAMPLE 4
The same compounds were also evaluated to determine whether they would induce sterility and/or premature abortion of fetuses by feeding the compounds to female rats. In accordance with the Allen-Doisy test ovarectomized rats were fed the compounds. No negative effect upon the production of female hormones or antifertility activity was noted. Additionally, feeding of the compounds to pregnant rats produced no abortive action.
EXAMPLE 5
The compounds 6,7-dihydroxy-3-(4-methoxyphenyl)-chromanon-(4) and 6,7-dihydroxy-3-(4-methoxyphenyl)-chroman were tested in lard using the Swift Stability Test at a series of concentrations. The results for two series of samples are shown in Tables II and III.
TABLE II______________________________________ANTIOXIDANT PROPERTIES OF6,7-dihydroxy-3-(4-methoxyphenyl)-chromanConcentration in Protection POVStripped lard [2g] [percent] [meqO.sub.2 /kg]______________________________________0.5 mg = 250 ppm 96 1.90.2 mg = 100 ppm 96 98 2.2 1.00.1 mg = 50 ppm 86 6.40.05 mg = 25 ppm 38 33 32.8 30.50.02 mg = 10 ppm 22 41None 0 0 52.6 45.4______________________________________
TABLE III______________________________________ANTIOXIDANT PROPERTIES OF6,7-dihydroxy-3-(4-methoxyphenyl)-chromanon-4Concentration in Protection POVStripped lard [2g] [percent] [meqO.sub.2 /kg]______________________________________0.5 mg = 250 ppm 99 0.50.2 mg = 100 ppm 94 98 3.1 0.80.1 mg = 50 ppm 53 21.30.05 mg = 25 ppm 44 25 29.3 34.10.02 mg = 10 ppm 22 41None 0 0 52.6 45.4______________________________________
EXAMPLE 7
An antioxidant composition was obtained from tempeh which included Texasin and additional isoflavones having the structure ##STR17## wherein R, R' and R" may be a methyl or ethyl group or hydrogen. This mixture of isoflavones was evaluated using the Swift Stability Test described hereinabove at 110° C. Lard samples containing 500, 50 and 1 ppm of the mixture were prepared by suitable dilutions of a stock mixture of the isoflavone mixture dissolved in 1:1 chloroform-methanol and the mixture was evaporated under vacuum to a clear solution. A similar set of lard samples containing BHT was also prepared for comparison. Results of the test are shown in Table IV.
TABLE IV______________________________________ Concentration StabilitySample Antioxidant (ppm) (hours)______________________________________Isoflavone mixture 500 36 50 22 1 22BHT 500 81 50 35 1 24Control 0 22______________________________________
It may be seen that the isoflavone mixture at 50 ppm and 1 ppm produced no significant increase in stability. With the 500 ppm sample, however, the stability was comparable to that of the 50 ppm BHT sample. Thus, the isoflavone mixture has antioxidant properties, but its activity is less than that of BHT under conditions of the test. It should be noted that this test is not completely suitable for evaluating isoflavones under all conditions because of the severity of the conditions used (temperature 110° C. with air bubbled through the sample).
EXAMPLE 8
An antioxidant composition was obtained from tempeh which included Texasin and trihydroxy-isoflavone. This mixture of isoflavones was evaluated using the Oven Storage Test described hereinabove at a temperature of 60° C. for 3 days. Peroxide values were determined for stripped lard samples containing the mixture. The results are set forth in Table V.
TABLE V______________________________________ Concentration ProtectionStripped Lard [g] Antioxidant [mg] = ppm [percent]______________________________________1.0 0.5 250 981.5 0.25 125 961.8 0.10 50 49______________________________________
EXAMPLE 9
A series of isoflavones either recovered from tempeh or chemically synthesized were evaluated using the Oven Storage Test for 40 hours and for 3 days at 60° C. In order to dissolve the isoflavones in 2 kg of stripped lard an emulsifier was employed such as a glycerol. The results are shown in Table VI.
TABLE VI__________________________________________________________________________ANTIOXIDANT PROPERTIES OF ISOFLAVONESAmount % Protection (40 h, 60° C.) % Protection (3 days, 60° C.)Isoflavone Conc. SAMPLE SAMPLE[mg] [% lard] 1 2 3 4 5 6 7 1 2 3 4 5 6 7__________________________________________________________________________1.0 0.05 21 21 0 100 91 45 67 28 21 31 99 77 50 200.5 0.025 -- -- -- 95 90 -- 57 -- -- -- 91 75 -- 90.1 0.005 0 0 8 43 0 15 17 0 22 46 29 1 2 00.05 0.00025 -- -- -- -- -- -- 17 -- -- -- -- -- -- 0__________________________________________________________________________ 1 6methoxy-7,4dihydroxyisoflavone (glycitein) 2 7methoxy-6,4dihydroxyisoflavone (kakkatin) 3 6,7dimethoxy-4hydroxyisoflavone 4 isoflavone mixture chemically synthesized without #7 5 6,4' dimethoxy-7-hydroxyisoflavone 6 isoflavone mixture from tompeh 7 6,7,4trihydroxyisoflavone
The test results indicate that each of the isoflavones has antioxidant properties. Particularly effective is the isoflavone mixture obtained by chemical synthesis which includes various methoxy-substituted isoflavones. Also, the compound 6,4'-dimethoxy-7-hydroxyisoflavone was particularly effective.
EXAMPLE 10
Synthesis of 1,2,4-trihydroxybenzene
Fifty grams (0.46 mol) of 1,4-benzoquinone was slowly added with continuous stirring and cooling to a mixture consisting of 150 g acetic acid anhydride and 3 ml concentrated sulfuric acid. During this reaction the temperature should be maintained between 40° and 50° C. After all of the quinone has been dissolved and the heat development has ceased, the reaction mixture was poured into two liters of water and the precipiate formed was filtered off. After drying in a vacuum desicator one obtained 1,2,4-triacetoxybenzene in the form of a light brown amorphorus powder which may be recrystallized from methanol.
Eighty grams of the crude 1,2,4-triacetoxybenzene were dissolved in 200 ml of methanol containing 6 g of concentrated sulfuric acid. The reaction mixture was boiled under reflux for one hour. Then the solution was cooled to room temperature and neutralized with an equivalent amount of fine powdered sodium carbonate. Thereafter 800 ml of ethylether was added whereupon sodium sulfate precipitated out, which was removed by filtration. Reaction by-products and contaminants being responsible for a dark red coloration may be removed employing solid silica gel. After evaporation of the supernatant under reduced pressure, a dark red oil is obtained which crystallized upon standing at 40° C. in the form of a slight reddish solid mass which is pure enough for the next step. This product is 1,2,4-trihydroxybenzene.
EXAMPLE 11
Synthesis of 6,7-dihydroxy-4'-methoxyisoflavone (6,7-dihydroxy-3-(4-methoxyphenyl)chromone)
35.4 grams of 1,2,4-trihydroxybenzene were suspended in 200 ml of dry ethylether containing 30 g of dry zinc-chloride (0.22 mol) and 50 g (0.34 mol) of p-methoxyphenylacetonitrile. The suspension was then exposed for 4 hours at 0° C. to a gentle stream of dry hydrogen chloride (HCl), the gas bubbling through the suspension under continuous stirring. Then the reaction mixture was kept for 70 hours at 4° C. and thereafter the supernatant was decanted from the heavy oil which had separated. The oil was washed twice with ethylether, then one liter of water and a few ml of concentrated hydrochloric acid were added and the mixture boiled for 1 hour under reflux. After cooling to room temperature the precipitate was collected by filtration and recrystallized from ethanol/water. This precipitate was (4-methoxybenzyl)-2,4,5-trihydroxyphenyl ketone.
Four grams (14.6 milimol) of (4-methoxybenzyl)-2,4,5-trihydroxyphenyl ketone were dissolved in 50 ml. of dry dimethylformamide. To this solution was added 7.5 grams of borontrifluoride-methyetherate (BF 3 -(CH 3 ) 2 O dropwise. Under spontaneous elevation of the temperature the color of the solution turns to yellowish-green. Then the temperature of the reaction is adjusted to 50° C. and a solution of 5 grams methanesulphonyl chloride (CH 3 SO 2 Cl) in 25 ml of dry dimethylformamide (DMF) is added dropwise. Thereafter, the solution is heated for 90 minutes at 90°-100° C. After cooling to room temperature, the reaction mixture is poured into 500 ml water and the resulting yellow precipitate is filtered off. After drying in a desicator the crude product is purified by boiling in 50 ml methanol and then 50 ml of ethyl ether. The resulting white powder can be recrystallized from dioxane or glacial acetic acid. This product is 6,7-dihydroxy-3-(4-methoxyphenyl)-chromone(texasin).
EXAMPLE 12
Synthesis of 6,7-dihydroxy-3-(4-methoxyphenyl)chromanon-4
Six grams of texasin (6,7-dihydroxy-3-(4-methoxyphenyl)chromone) were dissolved and partially suspended in 500 ml of ethanol and hydrogenated at normal pressure and room temperature using 10% palladium/charcoal as a catalyst under addition of 6 drops of triethylamine. The catalytic hydrogenation is continued until no starting material is detectable by means of thin layer chromatography. Thereafter, the catalyst is removed by filtration, an equal amount of water is added to the reaction mixture and the solution is evaporated under reduced pressure. After removal of the largest part of the ethanol the product precipitates out in pure form. After filtration and drying in a desicator 5.5 grams of a light yellow powder is obtained which may be recrystallized once from ethanol/water. The product has the formula C 16 H 14 O 5 , molecular weight 286, and melting point 215° C. It was characterized by UV, NMR, IR and Mass spectroscopy and determined to be 6,7-dihydroxy-3-(4-methoxyphenyl)-chromanon-4. The product is actually a mixture of optical isomers but since the isomers exhibit the same properties further characterization was not deemed necessary for the purposes of this disclosure. Therefore it is to be understood that the scope of the disclosure and claims embraces the optical isomers of the compounds discussed herein.
EXAMPLE 13
Synthesis of 6,7-dihydroxy-3-(4-mehtoxyphenyl)chroman
Fifteen grams of texasin (6,7-dihydroxy-3-(methoxyphenyl)chromone) were dissolved and partially suspended in 500 ml of ethanol and hydrogenated at normal pressure and room temperature using 10% palladium/charcoal as a catalyst under addition of 20 drops of concentrated sulfuric acid. The catalytic hydrogenation is continued until neither texasin nor any of the 6,7-dihydroxy-3-(4-methoxyphenyl)chromanon-4 was detected by thin layer chromatography. The further purification was identical to that described in Example 12. The product has the formula C 16 H 16 O 4 , molecular weight 272, and melting point 160° C. It was characterized by UV, NMR, IR and Mass spectroscopy and determined to be 6,7-dihydroxy-3-(4-methoxyphenyl)chroman. As in Example 12, the product is actually a mixture of optical isomers but since the isomers exhibit the same properties further characterization was not deemed necessary for the purposes of this disclosure. Therefore, it is to be understood that the scope of the disclosure and claims embraces the optical isomers of the compounds discussed herein.
EXAMPLE 14
Synthesis of 6,7-dihydroxy-isoflavone ##STR18##
50 g (0.46 mol) 1,4 benzoquinone (XI) was slowly added with stirring to a mixture of 150 g of acetic anhydride and 3 ml of conc. sulfuric acid during which the reaction mixture was cooled so as to keep the temperature between 40° and 50° C. After all of the quinone was dissolved and the heat of formation evolved, the reaction product was washed with an excess of water and the precipitate removed by filtration. Upon drying the precipitate 1,2,4-triacetoxybenzone (XII) was obtained as a light brown powder which can be identified as such after crystallization from methanol. The yield from the reaction was 106 g (91%).
80 g (0.32 mol) of the crude product XII in 200 ml of methanol was heated under reflux for one hour in the presence of 6 g conc. sulfuric acid. The reaction mixture was neutralized with sodium carbonate and then ether added. Na 2 SO 4 precipitated out and was separated by filtering. Known contaminants were removed by treatment with silica gel resulting in a solution having a dark red color. Upon distillation this solution yielded a dark red oil which rapidly crystallized to a light reddish solid material (XV). The yield of this reaction was 35.4 g (88%). ##STR19##
35.4 g (0.28 mol) of Compound XIII was suspended with 30 g waterfree ZnCl 2 (0.22 mol) in 200 ml dry ether and then mixed with 39.8 g (0.34 mol) benzylcyanide (XIV). Next, dry HCl gas was introduced in the reaction mixture with stirring for four hours at 0° C. After about 70 hours storage in a refrigerator the remaining solution was separated from the oil which had precipitated, washed two times with ether and heated one hour in 1 liter of water with which a few ml of HCl was mixed. After cooling the precipitate was removed by filtering and crystallized from alcohol/water. The yield of Compound XV was 25 g (36.5%). ##STR20##
3.4 g (0.0146 mol) Compound XV was dissolved in 50 ml dry DMF and 7.5 ml borontrifluoride-methyl-etherate added dropwise. Upon heating the solution assumed a yellow-green color. The solution was heated to 50° C. and then 5 g of methanesulfonyl chloride in 25 ml of DMF was added. Heating was continued for 90 minutes at 90°-100° C. and then the reaction mixture was cooled by adding about 0.5 liter water. The resulting yellow precipitate was removed by filtration and after drying yielded 3.1 g of a light brown powder which was purified by crystallization from methanol/water. This provided 3.0 g (81%) of Compound XVI, 6,7-dihydroxy-isoflavone.
EXAMPLE 15
6,7-dihydroxy-isoflavone may be hydrogenated using the methods described in Examples 12 and 13 to prepare the chromanon-4 and chroman respectively. Both of these compounds have been found effective as antioxidants at concentrations as low as 50 parts per million in the standard lard test described in Example 1.
As will be obvious to one skilled in the art, many modifications, variations, substitutions and other alterations can be made in the practices of this invention without departing from the spirit and scope thereof as set forth in the preceding description and examples or in the claims which follow. | The present invention concerns isoflavones and related compounds useful as antioxidants and in antioxidant compositions including edible fats and oils. Many of these compounds can be recovered from tempeh, a fermented soybean product. Others can be prepared by chemical modification of those recovered from tempeh. Additionally, all of the compounds can be chemically synthesized. The compounds of the present invention may be used to provide enhanced stability for a wide range of substances subject to oxidative deterioration including edible food products, oils and fats. | 2 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority from U.S. Provisional Application Ser. No. 62/237,302, filed Oct. 5, 2015, the entire disclosure of which is incorporated herein by reference in its entirety.
TECHNICAL FIELD
[0002] The present disclosure relates to devices and methods for subsurface perforating.
BACKGROUND
[0003] Hydrocarbons, such as oil and gas, are produced from cased wellbores intersecting one or more hydrocarbon reservoirs in a formation. These hydrocarbons flow into the wellbore through perforations in the cased wellbore. A number of wellbore tubulars may be used in a wellbore in addition to casing. Such tubulars including liners, production tubing, and drill pipe. In some situations, it may be desirable to sever a portion of a wellbore tubular. For example, a drill pipe may become stuck in a wellbore. Removal of the drill pipe may require cutting the drill pipe into two sections. In another example, pipe may need to cut during well abandonment.
[0004] The present disclosure addresses the continuing need for perforators useful for subsurface operations that may take place during the construction, completion, workover, and/or de-commissioning of a well.
SUMMARY
[0005] In aspects, the present disclosure provides a perforator for perforating a wellbore tubular in a wellbore. The perforator may include a cylindrical case having a bulkhead at a first end, an open mouth at a second end, and an interior volume; an explosive material disposed in the interior volume; and a cap covering the open mouth of the case, the cap having a disk section defined by a separator ring having a reduced strength zone that encircles the disk section, wherein an outer circumference of the cap form a seat for receiving an edge of the open mouth.
[0006] In aspects, the present disclosure provides a perforating tool for perforating a wellbore tubular in a wellbore. The perforating tool may include a charge holder connected to a work string and a perforator fixed in a charge holder disposed along the work string. The perforator may include a cylindrical case having a bulkhead at a first end, an open mouth at a second end, and an interior volume, wherein the first end includes a post projecting therefrom, the post having a slot; an explosive material disposed in the interior volume; and a metal cap covering the open mouth of the case, the cap having a disk section defined by a separator ring, the separator ring having a structurally weakened zone that encircles the disk section. A detonating cord may be received in the slot of the post.
[0007] In aspects, the present disclosure also provides a method for perforating a wellbore tubular in a wellbore. The method may include the step of forming a work string by connecting a charge holder connected to the work string, disposing a detonating cord along the work string, and fixing a perforator in the charge holder. The method may also include the steps of conveying the work string into the wellbore; positioning the perforator in the wellbore tubular; and firing the shaped charge by detonating the detonating cord.
[0008] It should be understood that certain features of the invention have been summarized rather broadly in order that the detailed description thereof that follows may be better understood, and in order that the contributions to the art may be appreciated. There are, of course, additional features of the invention that will be described hereinafter and which will in some cases form the subject of the claims appended thereto.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] For detailed understanding of the present disclosure, references should be made to the following detailed description taken in conjunction with the accompanying drawings, in which like elements have been given like numerals and wherein:
[0010] FIG. 1 illustrates an isometric side sectional view of a perforator in accordance with one embodiment of the present disclosure;
[0011] FIG. 2 illustrates an isometric view of the FIG. 1 perforator;
[0012] FIG. 3 illustrates a schematic side view of a well tool that uses the FIG. 1 perforator; and
[0013] FIG. 4 illustrates a well in which perforators according to the present disclosure may be used.
DETAILED DESCRIPTION
[0014] The present disclosure relates to devices and methods related to subsurface activity such as casing perforating, casing removal, completion, fishing operations to remove wellbore tubulars, etc. The present disclosure is susceptible to embodiments of different forms. There are shown in the drawings, and herein will be described in detail, specific embodiments of the present disclosure with the understanding that the present disclosure is to be considered an exemplification of the principles of the disclosure, and is not intended to limit the disclosure to that illustrated and described herein.
[0015] Referring to FIGS. 1 and 2 , there is sectionally shown one embodiment of a shaped charge 10 in accordance with the present disclosure. The shaped charge 10 is designed to generate a large diameter projectile for puncturing, cutting, and/or severing a wellbore structure. The shaped charge 10 may include a case 12 and a cap 14 . The case 12 may be formed as a cylindrical body 16 with a mouth 18 that is covered by the cap 14 . A quantity of explosive material (not shown) may be disposed inside an interior volume 52 of the case 12 , e.g., RDX, HMX and HNS.
[0016] The cap 14 is configured to generate a large diameter perforator which acts as a projectile that punctures, severs, cuts through, or otherwise perforates an adjacent structure. In one embodiment, the cap 14 includes a disk section 20 defined by a separator ring 22 . An outer circumference 24 of the cap 14 may include a lip 26 in which an edge of the case 12 seats. The cap 14 has a face 28 that is formed of the surfaces defining the disk section 20 and the outer circumference 24 . The face 28 may be configured to contact the wellbore structure to be cut or have a predetermined stand-off or spacing from an adjacent surface.
[0017] The disk section 20 contains the material which forms the perforator. The cap 14 and/or disk section 20 may be formed from a powdered metal mixture that is compressed at high pressures to form a solid mass in the desired shape. A high density metal may be included in the mixture in order to achieve the desired effect from the explosive force. Common high density metals used include copper and tungsten, but other high density metals can also be used. The mixture of metals typically contains various other ductile metals being combined within the matrix to serve as a binder material. Other binder metals include nickel, lead, silver, gold, zinc, iron, tin, antimony, tantalum, cobalt, bronze, molybdenum and uranium.
[0018] The disk section 20 may be generally flat and circular, but other geometric shapes may also be used (e.g., square or triangular). As used herein, the term “flat” is used as a contrast to a conical shape. However, in some embodiments, the flat disk section 20 may use a convex or concave arch to provide pressure integrity. The separator ring 22 is a portion of the cap 14 that is defined by a structurally weakened or reduced strength zone 24 that allows the disk section 20 to separate from the cap 14 when the explosives (not shown) inside the case 12 are detonated. A variety of mechanisms may be used to form the separator ring 22 in embodiments where the cap 14 is a single integral body. For example, a groove may be formed into the cap 14 . Alternatively, as shown, a fold may be formed into the cap 14 . The fold or groove may be “V” shaped, “U” shaped, sinusoidal, a square shape, a rectangular, or any other shape having curved or straight sides that are suited for weakening the zone 24 . In other embodiments, the separator ring 22 may have a reduced wall thickness section formed while the cap 14 is manufactured. In still other embodiments, the material at the separator ring 22 may be treated chemically to reduce strength. In yet other embodiments, the cap 14 may be an assembly of two or more discrete components; e.g., the disk section 20 may be a separate element.
[0019] Referring to FIG. 3 , there is shown a portion of a perforating tool 40 disposed in a wellbore 42 . The perforating tool 40 includes a shaped charge 10 fixed in a charge holder 60 and positioned to be in intimate contact with a wellbore tubular 44 . The charge holder may be a tube, strip, plate, or other structure that is shaped and configured to point the shaped charge 10 such that the disk section 20 can travel radially outward toward the wellbore tubular 44 . By intimate contact, it is meant that at least a portion of the face 28 ( FIG. 2 ) is in physical contact with the wellbore tubular 44 . In embodiments, it may be desirable to have the face 28 parallel with the surface of the wellbore tubular 44 . Thus, a majority of the disk section 20 has a surface that is parallel with the surface of the wellbore tubular 44 or, simply, the disk section 20 is substantially parallel with the wellbore tubular 44 . When positioned as desired, a suitable firing system may be used to detonate the shaped charge 10 . For instance, in one non-limiting embodiment, a detonating cord 46 may be used to detonate the explosive material (not shown) inside the shaped charge 10 . Upon detonation, the disk section 22 breaks free of the cap 14 along the separator ring 22 and is propelled against the surface of the wellbore tubular 44 . Once free of the cap 14 , the disk section 20 functions as a perforator that cuts through the wellbore tubular 44 .
[0020] In one non-limiting arrangement, the perforating tool 40 may be configured such that the shaped charge 10 is in physical contact with wellbore fluids. However, the explosive material inside the case 12 is isolated from contact with such liquids and gases as noted previously. In such embodiments, the charge holder 60 may be a strip or frame that does not enclose the charge holder 60 . Also, the detonating cord 46 may be insulated in a pressure tubing 47 that protects the energetic material of the detonating cord 46 from exposure to the ambient wellbore environment (e.g., drilling fluids, fluid pressure, temperature, formation fluids, gases, etc.). Thus, the explosive material of the detonating cord 46 and the shaped charge 10 do not physically contact fluids in the wellbore such as liquids (e.g., drilling fluids, water, brine, liquid hydrocarbons) or gases (e.g., natural gas, etc.). A detonator (not shown) may be used to detonate the detonating cord 46 , which then fires the shaped charge 10 .
[0021] The teachings of the present disclosure may be used in connection with a variety of shaped charge configurations. As shown in FIG. 1 , the case 12 may be configured as an encapsulated shaped charge. That is, the case 12 may include an unperforated bulkhead 50 . By “unperforated,” it is meant that there are no openings or passages through the case 12 . A post 54 formed at the bulkhead 50 may include a channel 56 for receiving the detonating cord 46 and/or a booster material (not shown). However, the channel 56 may be “blind” in that it does not extend and communicate with the interior 52 . Further, the engagement of the outer circumference 24 and the case 12 may also be fluid tight. Thus, the interior volume 52 of the shaped charge 10 may be hydraulically isolated from the ambient wellbore conditions. However, a conventional case, which has a channel, passage, or bore that does communicate with the interior of the case 12 may also be used.
[0022] Referring to FIG. 4 , there is shown a well construction and/or hydrocarbon recovery facility 100 positioned over a subterranean formation of interest 102 . The facility 100 can include known equipment and structures such as a rig 106 , a wellhead 108 , and casing or other wellbore tubular 44 . A work string 112 is suspended within the wellbore 104 from the rig 106 . The work string 112 can include drill pipe, coiled tubing, wire line, slick line, or any other known conveyance means. The work string 112 can include telemetry lines or other signal/power transmission mediums that establish one-way or two-way telemetric communication. A telemetry system may have a surface controller (e.g., a power source) 114 adapted to transmit electrical signals via a cable or signal transmission line 116 disposed in the work string 112 . To perforate or sever equipment in the wellbore 104 , the work string 112 may include a downhole tool 120 that as a perforating tool 122 that includes one or more shaped charges according to the present disclosure.
[0023] In one mode of use, the perforating tool 122 is positioned at a location 56 such that at least a portion of the face 28 ( FIG. 2 ) of the shaped charge(s) 10 ( FIG. 1 ) is in physical contact with the wellbore tubular 44 . The wellbore tubular 44 may be casing, liner, drill string, production tubing, etc. In some embodiments, a positioning tool 124 may be used to position the perforating tool 122 inside the wellbore tubular 44 . The positioning tool 122 may include arms, vanes, or other extendable elements that can contact an adjacent structure and push to the shaped charge 10 ( FIG. 1 ) of the perforating tool 122 into contact with the wellbore tubular 44 . The positioning tool 122 may use metal springs, inflatable packers, bladders, hydraulic fluid, or other mechanism to bias the extendable members into the extended position. Next, a firing signal from the controller 114 is used to detonate the shaped charge 10 . Upon detonation, the disk section 20 ( FIG. 2 ) cuts through the wellbore tubular 44 in a manner discussed previously.
[0024] The foregoing description is directed to particular embodiments of the present invention for the purpose of illustration and explanation. It will be apparent, however, to one skilled in the art that many modifications and changes to the embodiment set forth above are possible without departing from the scope of the invention. It is intended that the following claims be interpreted to embrace all such modifications and changes. | A perforating tool includes a charge holder connected to a work string and a perforator fixed in a charge holder disposed along the work string. The perforator includes a cylindrical case, an explosive material, a metal cap, and a detonating cord. The case has a bulkhead at a first end, an open mouth at a second end, and an interior volume. The first end includes a post having a slot. The explosive material is disposed in the interior volume. The metal cap covers the open mouth of the case and has a disk section defined by a separator ring. The separator ring has a structurally weakened zone that encircles the disk section. The detonating cord is received in the slot of the post. | 4 |
RELATED APPLICATIONS
[0001] This application claims the benefit of priority to PCT/EP2005/014043, filed 27 Dec. 2005, which claimed priority to European patent application serial number 05000289.8, filed 7 Jan. 2005; each of these applications is incorporated herein by reference.
FIELD
[0002] The present invention relates to an elevator unit and a control device for an elevator unit.
BACKGROUND
[0003] Elevator units comprise an elevator car which is movable in an elevator shaft. It is common to install buffers as safety devices in a pit of the elevator shaft, in order to decelerate the elevator car as it travels past the lowest stop (or the counterweight as it travels past the topmost stop) in the event of malfunction of the drive. In elevators with high nominal speeds, very large buffers are required for this purpose. Large buffers require a deep pit, which is expensive to construct. Use of buffers satisfies safety regulations which prescribe that the elevator unit must be designed and constructed so as to prevent the car from crashing in the elevator pit (see, e.g., European Safety Standard EN81).
[0004] In order to be able to make the buffers and hence the pit smaller, deceleration control circuits have already been proposed which allow the use of smaller single-use buffer devices as described for example in DE 20104389 U1 and DE 1021063 A1.
[0005] An excess speed detector with a plurality of light barriers arranged on the elevator car is already known from EP 0712804 B1. The light barriers generate measurements using a measuring strip attached to one side of the elevator shaft, and the speed or deceleration of the elevator car can be determined using these measurements. The measuring strip is of a redundant construction and consists of a marking track and a control track.
[0006] Moreover, in addition to the braking device provided for the elevator car, it is conventional and known to provide a catching device for emergencies, and this catching device comprises, in particular, catching wedges (cf. DE 29912544 U1).
SUMMARY
[0007] A goal of the invention is to provide an elevator unit in which the buffer device and hence the pit of the shaft can be made smaller or eliminated. Accordingly, an elevator unit, a control device, and a method for controlling an elevator unit are disclosed.
[0008] The elevator unit according to the invention and/or the control device according to the invention may operate as a reliable two-stage electronic system, thereby opening up the possibility of doing away with a safety buffer altogether or in part (by “in part”, it is meant that a smaller buffer could be provided, e.g. a cheap single-use buffer made of polyurethane, which is provided only for conceivable extreme cases). Thus, using the system according to the invention, existing buffer systems may consequently be made still smaller.
[0009] The invention essentially comprises three components, namely a detection system for determining the absolute position of the elevator car, a deceleration control circuit for detecting signals used for determining the speed or deceleration of the elevator car, and, as a third component, an evaluating circuit for processing the signals supplied by the detection system and the deceleration control circuit. This is a so called redundant/diverse system. The redundant/diverse evaluation according to the invention is achieved by means of a two-channel evaluating circuit, wherein a first and a second sensor for detecting relevant signals are each connected in redundant/diverse manner to one of the two channels of the evaluating circuit and a third sensor for an (additional) two-out-of-three selection is connected to both channels of the evaluating circuit.
[0010] One advantage achieved with the present invention is that a buffer of the kind described above may be omitted entirely, as the procedure according to the invention ensures reliable and unambiguous detection of the position of the elevator car in addition to determining its speed. Total replacement of a buffer may result in a very great space saving; for example, large (high-rise) elevator units commonly have corresponding car speeds of 6 to 7 meters/second and a buffer height of up to 8 or 9 meters.
[0011] The safety evaluation features of the invention can therefore always advantageously be used whenever the elevator car has to be maintained at a certain spacing from an object located below or above it. In most cases, this object will be the pit of the shaft or the ceiling of the shaft, but it may also be a second elevator car travelling in the same elevator shaft underneath the elevator car (e.g., a TWIN® system of the present Applicant).
[0012] Further features and embodiments of the invention will become apparent from the description and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] It will be understood that the features described above and those to be explained hereinafter can be used not only in the particular combinations specified but also in other combinations or on their own without departing from the scope of the present invention.
[0014] The invention is schematically shown by means of an embodiment shown in the drawings and is described in detail hereinafter with reference to the drawings.
[0015] FIG. 1 a shows a plan view of an arrangement for detecting signals for determining the absolute position of an elevator car.
[0016] FIG. 1 b shows the arrangement of FIG. 1 b in perspective view.
[0017] FIG. 2 a shows a plan view of an arrangement for detecting signals for determining the speed or deceleration of an elevator car for a deceleration control circuit.
[0018] FIG. 2 b shows the arrangement of FIG. 2 b in perspective view.
[0019] FIG. 3 shows a structural diagram of an evaluating circuit.
DETAILED DESCRIPTION OF THE INVENTION
[0020] As already mentioned herein, the system according to the invention essentially comprises three components.
[0021] The first of these components is a detection system for detecting signals for determining an absolute position of the elevator car. A detection system of this kind may operate for example on the basis of a magnetic strip having a plurality of pole divisions arranged in a non-repeating pattern. Magnetic strips of this kind are known per se and are described for example in DE 19732713 A1 and DE 10234744 A1. German Patent Application 102004037486.4, which is incorporated herein by reference, also describes a double signal band for determining the state of motion of a moving body.
[0022] A magnetic strip 90 of this kind which is suitable for performing the invention is shown in FIGS. 1 a and 1 b . The magnetic strip 90 comprises a plurality of pole divisions 92 , 94 which are arranged in a non-repeating and hence unambiguous pattern. A magnetic sensor 9 , such as a Hall sensor, is arranged on the elevator car 6 (not shown in detail), and without making contact, it “reads” the pattern of the magnetic strip 90 , which is fixedly mounted in the elevator shaft (e.g., magnetic strip 90 is mounted in a recess in the elevator rails (not shown)). In addition to the absolute position, the speed of the elevator car 6 can also be derived from the signal supplied by the magnetic sensor 9 . Naturally, there are other methods familiar to those skilled in the art for determining the absolute position of an elevator car, which can be used within the scope of this invention (e.g., a laser measuring system operating on the principle of a bar code reader).
[0023] The second of the components mentioned above is a control circuit. FIGS. 2 a and 2 b show an arrangement which serves to detect signals in order to determine the speed or deceleration of an elevator car for the control circuit. This arrangement comprises a strip 70 on which a pattern 72 , 74 is provided, wherein the pattern is capable of being detected by a sensor 7 . The strip is fixedly mounted in the elevator shaft in the region of the deceleration section of the elevator car 6 (e.g., above the pit or below the ceiling of the shaft, as the invention can equally be used above the pit or in the safety region at the top end of the shaft). The pattern of the alternating sensor-relevant measuring sections 72 , 74 on the strip 70 is selected so that the detected signals produce a constant time value, i.e. the individual measuring sections 72 , 74 become steadily shorter towards the upper end of the elevator shaft. Any inordinate deceleration of the elevator car can thus easily be detected by an evaluation as a result of deviation from the constant desired time value.
[0024] The strip 70 for detecting signals in order to determine the speed or deceleration of an elevator car can be produced in a number of ways known to the skilled man, e.g. by means of a metal strip stamped with perforations, the pattern of which is detected by a forked light barrier, or by magnetic pole divisions or optical reflective sections.
[0025] As can be seen from the perspective views in FIGS. 1 b and 2 b , the two measuring strips 70 , 90 for the two components described can be provided on the front and back of a carrier 1 (e.g., in the recess of an elevator rail), and the associated sensors 7 and 9 for the two strips 70 and 90 , respectively, can be respectively provided on the legs 42 and 40 of a U-shaped element on the elevator car. The legs 42 , 40 surround the carrier 1 of the strips 70 , 90 and thus allow the strips 70 , 90 to be simultaneously read by the associated sensors 7 , 9 .
[0026] The third component is an evaluating circuit 30 as shown by way of example in FIG. 3 . The evaluating circuit 30 may take the form of a microcontroller 10 which is electrically connected to a braking device and a catching device. The evaluating circuit 30 constitutes the core of a control device according to the invention.
[0027] Attached to the microcontroller 10 are a safety relay device in the form of a first safety relay 11 and a second safety relay 12 , a braking device (not shown) and an actuator 13 connected to the first safety relay 1 , said actuator 13 actuating a catching device 14 . Shown on the left of FIG. 3 in highly schematic form are the two measuring strips which are hereinafter referred to as the double signal strip 100 , for short, in the interest of simplicity. Shown together with double signal strip 100 are sensor devices 7 to 9 , the sensor devices 7 to 9 being mounted on the outside of the elevator car as already mentioned and travelling past the double signal strip 100 when the elevator car is in motion.
[0028] For reliably detecting the speed, two redundant/diverse sensors 7 and 9 with corresponding two-channel evaluation are sufficient per se. In order to operate the elevator unit with the minimum possible disruption, a third sensor 8 may be provided according to an additional embodiment of the invention in order to detect the speed and position of the elevator car. Thus, a “2 out of 3 selection” is possible, and in this way, transitory fault signals produced by electromagnetic influences (e.g., transitory fault signals causing the unit to come to an immediate standstill) are prevented.
[0029] The electrical output signals S 1 to S 3 from the sensors 7 , 8 , 9 are fed into the microcontroller 10 . The microcontroller 10 has a first channel A and a second channel B. Moreover, an elevator control 31 may be provided, as shown on the right in FIG. 3 ; elevator control 31 (if provided) is separately connected to the microcontroller 10 and to the first and second safety relays 11 , 12 .
[0030] The first safety relay 11 and the second safety relay 12 are each attached to the first channel A and to the second channel B of the microcontroller 10 . The first safety relay 11 is coupled to the actuator 13 which actuates the catching device 14 ; the first safety relay 11 can thereby initiate the catching device 14 . The second safety relay 12 acts on the braking device (not shown) and can trigger the braking device when a corresponding control signal is received.
[0031] Each of the channels A and B comprises three input modules 15 to 17 to which the electrical signals S 1 to S 3 of the relevant sensor devices 7 to 9 are applied. To increase the operational reliability of the apparatus, these two channels are formed with different hardware (e.g., by means of two different processors). Each channel of the microcontroller 10 may have a RAM 21 , a flash memory 22 , an EEPROM 23 , an OSC Watchdog 24 , a CAN module and individual separate input modules 15 to 17 . The hardware construction of the microcontroller 10 corresponds to a standard commercial electronic component of a kind which is industrially available, and therefore its construction and its internal computing process will not be described in more detail.
[0032] The electrical signals from the two sensor devices 7 and 8 for detecting the speed are each applied to the modules 15 and 16 of a respective channel A, B. A corresponding calculation is carried out on the signals applied to the modules, from which the actual speed of the elevator car 6 can be determined. The process of determining the actual speed is restricted to a simple measurement of the time taken to travel a measured distance. If this time is greater than a reference time permanently stored in channels A and B, the speed is within a safe range. The different lengths of the measured sections, which become shorter and shorter towards the end of the shaft, also necessarily provide a direct association with the position of the elevator car.
[0033] Each of the channels A and B also comprises an interface 17 , which may be constructed as a parallel or serial input. The sensor 9 connected to these inputs provides absolute positional information and further information as to the speed of the elevator car in the shaft.
[0034] In the memory areas of the channels A and B, a reference speed is stored for each position in the range of deceleration distances, this reference speed having been stored by means of a calibration process when the elevator unit was installed. These reference speed values are thus dependent on the deceleration selected and the jerking of the elevator unit in question. In a simple standard unit, these values may also already be permanently programmed on delivery. This stored reference speed is compared, in the deceleration range, at every new position of the elevator car supplied by the sensors 7 to 9 , with the speed actually traveled, measured by the sensors 7 to 9 . If a fixed or adjustable tolerance threshold of the actual speed traveled is exceeded, the second safety relay 12 is actuated, thereby causing the operating brake to come into play.
[0035] If a second tolerance threshold is exceeded or if the braking device fails, the first safety relay 11 is also actuated, which in turn triggers the actuator and thereby actuates the catching device for the elevator unit.
[0036] All the reference values are stored in a safe storage area and are constantly monitored for their correctness using memory testing procedures known per se. To increase the operational reliability still further, the first channel A and the second channel B may be continuously compared with one another to provide a comparison of the computed variables of the first channel A and second channel B. The comparison may be used to detect differences in the electrical signals of the sensor devices 7 to 9 (e.g., due to faults) at the earliest possible opportunity.
[0037] The first safety relay 11 and the second safety relay 12 are operated with separate circuits, for safety reasons. A plurality of safety relays may also be connected to each channel of the microcontroller 10 , and these safety relays are analogously operated with separate circuits. The respective safety relays 11 , 12 are electrically connected to the individual channels A, B of the microcontroller 10 . Such connections allow channels A, B to apply control signals to the corresponding safety relays 11 , 12 , as will be explained hereinafter, and further allow safety relays 11 , 12 to send return feedback information to the microcontroller 10 .
[0038] The first safety relay 11 is coupled to the actuator 13 which actuates the catching device 14 , as explained above. The catching device 14 may be a wedge device, known per se, which is driven between a guide rail of the elevator unit and an edge region of the elevator car in order to stop the elevator car in an emergency. When the car 6 is stationary, the actuator can also be activated and deactivated by an electrical signal for testing purposes. After the testing operation has ended, normal operation of the elevator unit can be resumed.
[0039] After the braking device has been initiated by a control signal from the second safety relay 12 or after the catching device 14 has been actuated by a control signal from the first safety relay 11 , further operation of the apparatus according to the invention is not possible until an operational check has been carried out by qualified personnel. Once the check is complete, a corresponding release signal is sent from the respective safety relay 11 or 12 back to the corresponding channel A, B, after which normal travel of the elevator unit can continue.
[0040] The device explained herein ensures, by means of cooperation among the double signal strip 100 , electrical components, and magnetic or optical components, effective speed limitation or speed control of the elevator car. The apparatus can thus replace conventional mechanical safety systems for speed limitation, i.e. safety buffers. Similarly, conventional electrical deceleration control circuits, which are generally used in conjunction with oil buffers in elevator units intended to operate at higher speeds, can be replaced by the safe detection of deceleration provided according to the invention.
[0041] In the light of the safety concept explained above, the apparatus may meet elevator guideline requirements. | The invention relates to an elevator unit comprising an elevator car which is movable in an elevator shaft and is equipped with a braking device and a catching device encompassing catching elements. The elevator unit further comprises a system for detecting signals used for determining an absolute position of the elevator car, a control circuit for detecting signals used for determining the speed or deceleration of the elevator car, and a circuit for evaluating the signals of the detection system and the control circuit. Based on the input signals, the evaluation circuit evaluates whether the speed of the elevator car lies within a predefined interval in the determined position and causes the braking device to be actuated via a first output of the evaluation circuit and/or the catching device to be triggered via a second output of the evaluation circuit according to the result of the evaluation. | 1 |
This is a continuation-in-part of application Ser. No. 130,759, filed Dec. 10, 1987 and now abandoned.
TECHNICAL FIELD
This invention relates to electrolytes based upon lower alkyl or alkylol sulfonic acids or their derivatives for the high speed electroplating of tin, lead, or tin/lead alloys, particularly for those for use in high speed electroplating equipment.
BACKRGOUND OF THE INVENTION
Electroplating baths for depositing tin, lead, or their alloys have been used for many years in electroplating equipment. High speed electroplating equipment and processes are well-known in the industry and generally consist of directing the work to be plated into the electroplating cell from one end, allowing the work to proceed through the electroplating cell and exit thereafter the cell at the other end. The electroplating solution is removed or overflows the electroplating cell into a reservoir and the solution is pumped from the reservoir back into the electroplating cell to provide vigorous agitation and solution circulation. Many variations of these electroplating cells can exist, but the general features are as described.
There are a number of desirable features that the electroplating solution should possess for improved operation in this type of equipment or processing, as follows:
1. The solution must be able to electroplate the desired alloy deposit at the high speeds required.
2. The deposit should be lustrous and fine grained, even at the high current densities required for high speed plating.
3. The deposit should have good solderability and be capable of meeting the solderability requirements specified for such deposits.
4. The solution should be stable and the additives must withstand exposure to the strong acid solution as well as to the introduction of air which would take place as a result of the vigorous solution movement in high speed plating machines.
5. The solution should remain clear and free from turbidity, even at elevated temperatures such as 120°-130° F. or higher. Due to the high current densities involved and relatively low solution volumes, these baths tend to heat up in high speed electroplating equipment until the solution reaches equilibrium at an elevated temperature. The additives used must be of a type that will not turn the solution turbid at such elevated temperatures.
6. Because of vigorous solution movement and solution mixing with air, there is a strong tendency to produce a foam which is detrimental to the electroplating process. Under extreme conditions, this foam can build up in the reservoir tank with resultant overflow onto the floor, thereby losing a large quantity of solution to the waste stream. In some applications of "controlled depth plating," the parts to be electroplated are only partially immersed in that a portion of the work is below the solution level. It is desirable to have a distinct and uniform line of demarcation separating the unplated portion from the plated portion of the work. If the solution generates foam, such foam will prevent the formation of a good line of demarcation. Foam can also interfere with the operation of the pump that is being used to generate agitation. Arcing between the anode and cathode is also possible due to the presence of foam. Because of these problems, the additives used should not generate foam in the plating equipment.
Many electrolytes have been proposed for electroplating tin, lead, and tin/lead alloys and one of these is described in U.S. Pat. No. 4,701,244. This patent discloses the electroplating of tin, lead or tin/lead alloys from lower alkyl sulfonic acid baths which contain brightening additives as well as many wetting agents of various types. Surfactants claimed to be useful are betaines, alkylene oxide polymers, imidazolinium compounds, quaternary ammonium compounds, ethylene oxide derivatives of amines, phosphonates, amides and many others.
U.S. Pat. No. 4,662,999 discloses an electroplating bath for electrodeposition of tin, lead, or tin/lead alloys from alkane or alkanol sulfonic acid baths that also contain surfactants plus other additives. In this patent, the surfactant can be non-ionic, cationic, anionic or amphoteric. A great many examples are given for the various types of surfactants and the patent enumerates a large number of the various types of wetting agents which can be used.
U.S. Pat. No. 4,673,470 describes a tin, lead, or tin/lead alloy plating bath based upon an aliphatic or aromatic sulfocarboxylic acid. Instead of the alkene or alkanol sulfonic acids disclosed in previous patents, this patent includes a carboxylic acid radical in the organic sulfonic acid compound. The electroplating baths described contain brightening agents plus a surface active agent, with particular emphasis on those surface active agents that are non-ionic. A very broad group of non-ionic surface active agents is described as being useful, and many different wetting agents are recited.
In all of the prior art baths that have been proposed, the wetting agents that have been described to be useful for producing either bright or matte deposits are very broadly described and are deemed equivalent to one other. Numerous examples are givenin each of these prior art patents directed to a wide variety of agents of many different types, most of which contain some type of oxide or similar condensation compound.
The vast majority of such prior art wetting agents are unsuitable for high speed plating in modern day high speed plating equipment. These wetting agents are mainly incapable of satisfying some or all of the requirements for these electrolytes that are listed above. The present invention resolves this problem by providing specifically preferred agents which are highly useful in high speed electroplating equipment and processes.
SUMMARY OF THE INVENTION
The invention relates to an electrolyte for depositing tin, lead or tin/lead alloys upon a substrate by high speed electroplating, which comprises a basis solution of an alkyl or alkylol sulfonic acid; and at least one of a solution soluble tin compound or a solution soluble lead compound; and a surfactant of an alkylene oxide condensation compound of an aliphatic hydrocarbon having between one and seven, and preferably less than six carbon atoms and at least one hydroxy group; or solution soluble derivatives thereof. Preferably, the surfactant imparts to the solution a cloud point of above about 110° F., and the electrolyte may include a brightening agent when bright deposits are desired.
A preferred hydrocarbon is an alcohol, such as butyl alcohol. Also, to achieve the desired cloud point, the alkylene oxide compound may be ethylene oxide wherein between about four and 40 moles of ethylene oxide, and preferably between six and twenty-eight, are used to form the condensation compound. Some of the moles of ethylene oxide may be replaced with propylene oxide.
Another suitable surfactant is an alkylene oxide condensation compound of an aromatic organic compound having 20 carbon atoms or less; or solution soluble derivatives thereof. This aromatic compound may preferably contain one or two rings, preferably containing between 10 and 12 carbon atoms when two rings are utilized. Also, the aromatic organic compound may include an alkyl moiety of six carbon atoms or less, and one or more hydroxyl groups. Preferably, the aromatic organic compound is benzene, naphthalene, phenol, toluene, bisphenol A, styrenated phenol, or an alkylated derivative thereof.
Therefore the desired surfactants include an organic compound having 20 carbon atoms or less condensed with a sufficient amount of an alkylene oxide compound or solution soluble derivatives thereof to impart a cloud point of above 110° F. to the solution.
The invention also includes a system and process for the high speed electroplating of tin, lead, or tin/lead alloys. This system utilizes the high speed electroplating equipment of the type described above. Such equipment includes an electroplating cell, an overflow reservoir adjacent the cell, a pump for returning solution from the reservoir to the cell through one or more sparge pipes, and means for directing a substrate to be plated from an entry point at one end of the cell to an exit at a second end of the cell. The electrolytes of the invention are introduced into the equipment in a manner such that the cell is substantially filled with the electrolyte. Also, the electrolyte continuously overflows into the reservoir and is continuously returned into the cell so that vigorous agitation and circulation of the electrolyte within the cell is achieved. Thus, substrates are continuously electroplated as they pass through the cell.
DETAILED DESCRIPTION OF THE INVENTION
Tin, lead and tin/lead alloy electroplating compositions are described herein that are specifically designed to deposit acceptable matte or bright deposits from electrolytes that are suitable for operation at high speeds in modern high speed electroplating equipment. Only a limited number of such wetting agents can satisfy all the requirements listed above for successful high speed electroplating. These compounds comprise relatively low molecular weight ethylene oxide derivatives of aliphatic alcohols containing an alkyl group of less than eight carbon atoms or ethylene oxide derivatives of aromatic alcohols containing a maximum of two aromatic rings which may be alkyl substituted providing the alkyl grouping contains less than six carbon atoms and including bis compounds again provided that the alkyl grouping contains less than six carbon atoms. The aromatic compound, whether alkylated or not, should not contain more than 20 carbon atoms prior to condensation with the alkylene oxide compound.
The surface active agents that are suitable for this invention are those that satisfy all of the listed above requirements, namely: deposits have good solderability, good matte or lustrous finish with satisfactory grain refinement; the solution should be stable in the acid bath, electroplate at high speeds, the cloud point of the solution should be above about 110° F., and the solution should have little or no foam during the electroplating operation.
Foaming is determined in the laboratory by using a basis solution that is typical of those used in high speed electroplating machines. The solution contains the following:
Tin metal (as tin methane sulfonate): 20 g/l
Methane sulfonic acid: 15% by volume
Surface active agent under test: 1% by volume
Temperature: ambient to 75° F.
The relative degree to which the surface active agents foam in the basis solution is tested by placing 100 ml of the solution into a 250 ml graduated cylinder.
Air is supplied by a commercial laboratory or fish tank aerator and fed into the bottom of the solution in the graduated cylinder through a sparger. Two tests are performed. The first one requires pumping air for two minutes to determine if the foam height exceeds 150 ml or goes over the top of the graduated cylinder. If it does, the surface active agent is considered unsuitable and no further work is done. The second test involves bubbling air into a fresh solution for ten seconds. At the end of ten seconds, the maximum foam height is read on the graduated cylinder and a time for foam to completely dissipate down to the original 100 ml mark is noted. In order for a surfactant to pass such a test, the maximum foam height should not exceed 150 ml, and the time for foam to dissipate should not exceed 20 seconds.
Cloud point is measured by taking the basis solution containing 1% of the surface active agent and slowly raising the temperature until the solution begins to turn cloudy. A cloud point above approximately 120° F. is highly satisfactory: those 110° F. or below are generally found to be unsatisfactory.
The basis solution for use in high speed electroplating equipment and processes of this invention generally contains relatively high concentrations of metals and acid. Such high concentrations also affect the cloud point of the electrolytes. For example, a surfactant which would impart a high cloud point to dilute electrolytes may impart a low cloud point to these concentrated electrolytes. Therefore, it is important to determine the cloud point for the specific overall electrolyte that is contemplated for electroplating the desired deposit.
The high speed electroplating characteristics and deposit grain refinement potential of the solution are determined in a Hull cell operated at 5 amps total current for 1 minute at 120° F., with paddle agitation. The solution contains:
Tin metal (as tin methane sulfonate): 70 g/l
Total methane sulfonic acid: 30% by volume
Surfactant: 1-10 ml/l, as required.
Under these conditions, the Hull cell panel should show a deposit with no more than 1/4" of burn in the high current density area and the deposit on the balance of the panel should be matte or somewhat lustrous, with a pleasing grey, smooth finish.
The stability of the electrolyte containing the surfactant is determined by electrolyzing the bath for at least 20 ampere hours per liter. The characteristics of the electroplating solution and its deposit should not have been affected by electrolysis.
The solderability of the deposit is determined by following the methods given in Mil-Std 202F, dated April, 1986, Method 208 F. The deposit must pass the test as given in this military specification.
The surface active agents that are included in this invention all include an organic compound which is condensed with a sufficient amount of an alkylene oxide, preferably ethylene oxide, to satisfy the requirements of high cloud point, stability, and high current density grain refinement. Propylene oxide can also be included with the ethylene oxide; however, the amount of propylene oxide used and its ratio to ethylene oxide must be such that the cloud point is still high enough to pass the above requirements. Propylene oxide can be included to reduce the foaming characteristics of a surfactant; however, only a limited amount can be used since propylene oxide also lowers the cloud point of the resultant electrolyte. One skilled in the art can easily determine the amount of propylene oxide by routine testing.
The organic compound can be any aliphatic hydrocarbon (saturated orunsaturated) of 8 carbon atoms or less containing at least one hydroxy group. Similarly, the organic compound can also be an aromatic ring compound such as benzene, naphthalene, phenol, toluene, bisphenol A, styrenated phenol, and the like, providing there is not more than two rings and the length of the substituted alkyl chain is limited to six carbon atoms or less. Also, the ring can be substituted with one or more hydroxyl groups.
As an illustration of specific compounds, octylphenol ethoxylate with 12 moles of ethylene oxide would not be suitable for this invention because its foaming characteristics are too great due to the alkyl chain length being too great. Beta-naphthol with 13 moles of ethylene oxide, is suitable for this invention and is capable of passing all of the requirements. Styrenated phenol with two or more moles of styrene condensed with 12 moles of ethylene oxide is not suitable since it has three aromatic rings. Ethyloxylated bisphenol A is also suitable for this invention and is capable of passing all of the above requirements. This compound has two aromatic rings and three alkyl carbon atoms.
Other suitable surfactants for this invention can include ethyloxylated butyl alcohol, with or without propylene oxide. As the chain length of the aliphatic alcohol is increased, the foaming characteristics will also increase. The foaming characteristics in this group of compounds can be decreased considerably by the inclusion of some propylene oxide into the molecule. However, this must be controlled to prevent the lowering of the cloud point, which would make the compound unsuitable if the resultant cloud point is less than 110° F. The maximum length of the alkyl group should be 8 carbon atoms or less in this series.
In this invention, the plating bath contains solution soluble tin and/or lead metals, preferably as alkyl sulfonates or alkanol sulfonates, plus some extra or free alkane or alkanol sulfonic acid. The surfactants suitable for this invention have been described in order to produce suitable deposits which are matte or semi-lustrous: however, it is also possible to improve the brightness of the deposit by adding known brightening agents such as those disclosed in any of the prior art patents listed earlier. The resultant plating bath will then have all of the desirable characteristics of a bright or semi-bright deposit.
The surface active agents can be rendered more solution soluble by techniques generally known in the art. Such solution soluble derivatives of the desirable surface active agents can be made, e.g., by sulfating, sulfonating, phosphating, phosphonating, carboxylating, etc., provided the derivative does not impair the suitability of the material for purposes of this invention stated previously. There are a wide variety of high speed electroplating equipment commercially available today. One typical apparatus is disclosed in U.S. Pat. No. 3,819,502 to Meuldjik, while others are disclosed in articles entitled "High Speed Electrogalvanizing Line with Insoluble Anode at Kimitsu Works of Nippon Steel Corporation" by M. Morimoto et al., "Swim Plating as a Continuous Process" by J. J. Miles et al., and "Continuous Plating of Copper, Nickel and Chromium on Wide Steel Strip For Decorative and Function Applications" by H. Wettner. A high speed machine for controlled depth electroplating is disclosed in an article entitled "How to Save Gold With Selective Deposits" by C. D. Eidschun. Each of these papers was presented at the American Electroplater's Society's Second Continuous Plating Seminar, Chicago, Ill., Jan. 24-26, 1977. It must be emphasized that these high speed electroplating units are merely illustrative and fall within the general description given in this application. Those skilled in the art are aware of a wide range of similar machines which are useful for high speed electroplating according to this invention.
EXAMPLES
The scope of the invention is further described in connection with the following examples which are set forth for the sole purpose of illustrating the preferred embodiments of the invention and which are not to be construed as limiting the scope of the invention in any manner.
Three stock solutions were used in each example to test the ability of each surfactant to electroplate pure tin, a 90/10 tin/lead alloy and a 60/40 tin/lead alloy. These solutions were as follows:
______________________________________ Pure Tin 90/10 60/40______________________________________Tin metal (as tin methane sulfonate) g/l 72 72 40Lead metal (as lead methane sulfonate) g/l -- 18 26Methane sulfonic acid (vol. %) 5 15 5______________________________________
The surfactants of each example were added in increments until the optimum amount was reached. Tests of the solutions and the electrodeposits were made using all the test methods listed above:
(1) foaming
(2) cloud point of solution
(3) grain refinement (smooth, light grey satin finish)
(4) speed of electroplating
(5) solderability of deposits
(6) stability of solution
Each of the solutions of these examples exhibited a pH of less than 0.5 [3, with most being 2 or lower].
EXAMPLE 1
Bisphenol A with 8 moles ethylene oxide was used in an amount of between 6 and 12 ml/l. The solutions with this surfactant passed all six tests.
EXAMPLE 2
Bisphenol A with 10 moles ethylene oxide was used in the same amounts as in Example 1. Solutions with this surfactant also passed all tests.
EXAMPLE 3
Sulfated Bisphenol A with 30 moles ethylene oxide was used in an amount of between 3 and 6 ml. Solutions with this surfactant also passed all tests.
EXAMPLE 4
Beta-Naphthol with 13 moles ethylene oxide was used in an amount of between 0.5 and 1 ml. Solutions with this surfactant also passed all tests.
EXAMPLE 5 (COMPARATIVE)
Polystyrenated phenol with 12 moles ethylene oxide was used in an amount between 3 and 6 ml/l. This surfactant forms too much foam and is not satisfactory despite that it passed the other tests.
EXAMPLE 6 (COMPARATIVE)
Octyl alcohol with 12 moles ethylene oxide was used in an amount of between 3 and 8 ml/l. This surfactant forms too much foam and is not satisfactory.
EXAMPLE 7 (COMPARATIVE)
Butyl alcohol with 5 moles ethylene oxide was used in an amount of between 2 and 8 ml/l. Although, the grain refinement of the deposit is not satisfactory, the other tests were passed: thus, the number of moles of ethylene oxide must be increased to at least six or more, as shown by Examples 8 and 9.
EXAMPLE 8
Butyl alcohol with 16 moles ethylene oxide plus 12 moles propylene oxide was used in an amount of between 1 and 4 ml/l. Solutions with this surfactant passed all tests.
EXAMPLE 9
Butyl alcohol with 8 moles ethylene oxide plus 6 moles propylene oxide was used in an amount of between 0.5 and 2 ml/l. Solutions with this surfactant passed all tests.
EXAMPLE 10
Bright deposits can be obtained by adding known brighteners such as aromatic aldehydes such as chlorobenzaldehyde or derivatives thereof, such as benzal acetone, to any of the above solutions that pass all the tests.
While it is apparent that the invention herein disclosed is well calculated to fulfill the objects above stated, it will be appreciated that numerous modifications and embodiments may be devised by those skilled in the art, and it is intended that the appended claims cover all such modifications and embodiments as fall within the true spirit and scope of the present invention. | An electrolyte, system and process for depositing tin, lead or tin/lead alloys upon a substrate by high speed electroplating, which includes a basis solution of an alkyl or alkylol sulfonic acid; and at least one of a solution soluble tin compound or a solution soluble lead compound; and an alkylene oxide condensation compound of (1) an aliphatic hydrocarbon having seven, preferably six or less carbon atoms and at least one hydroxy group, or (2) an aromatic organic compound having at least one hydroxyl group and no more than two independent or joined rings optionally substituted with an alkyl moiety of a total of twenty carbon atoms in one or six carbon atoms or less. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an image forming apparatus such as a copying machine and more particularly to an image forming apparatus having a re-feeding unit for feeding sheet with an image formed on one side to a transfer unit to form another image on the sheet.
2. Description of the Prior Art
To meet the recent requirement for multifunction of a copying machine, there has recently been used a copying machine having a composite copying function capable of effecting transfer of images a plural number of times onto one side of a single sheet, or a copying machine having a both-side copying function capable of effecting transfer of images onto both the surface and the back. Further, in U.S. Ser. No. 883,144 filed on July 8, 1986 there is disclosed a copying machine having both a composite copying function of making transfer of images in plural number of times onto one side of sheet and a both-side copying function of making transfer of images onto both sides of sheet.
A copying machine having any of the above-mentioned functions is provided with a primary passage for feeding each sheet from the interior of a feeding section which contains copying sheets up to a discharge section through a transfer section and a fixing section and also provided with a secondary passage contiguous to the primary passage and formed in a re-feeding section which is for returning the sheet with an image formed thereon past the fixing section again to the transfer section.
Since the sheet fed into the secondary passage has once passed through the fixing section, it is in a curled state with heat or its water content or stiffness has been changed as compared with the original sheet, resulting in that jam of sheet is more likely to occur in the secondary passage.
According to the prior art, in the event of a jam in the sheet feeding passage, the occurrence and position of the jam are detected by a sheet position detecting sensor and a timer which detects the time during which the sheet is detected by the sensor, and the jam position is indicated by an indicator. In order to remove the sheet which is causing the jam to the exterior of the copying machine, the sheet conveying path is capable of being opened. The operator puts his hand into the jam portion of the interior of the copying machine and removes the sheet to the exterior.
Consequently, a conventional copying machine of this type becomes larger in size in order to ensure the working space of the operator. Particularly, recent copying machines are compact, so in the case where a secondary passage for effecting re-feed is provided, there is no extra space for opening the said passage in the interior of the machine, resulting in that it is becoming more and more difficult to deal with the jam of sheet in the secondary passage.
SUMMARY
It is an object of the present invention to provide a small-sized image forming apparatus having a re-feed unit for feeding sheet with an image formed on one side thereof again up to a transfer section to form another image thereon.
It is another object of the present invention to provide an image forming apparatus having motor-driven rollers for returning sheet which causes a jam in the re-feed unit to an upstream end of the re-feed unit.
It is a further object of the present invention to provide an image forming apparatus having a sheet removing area for discharging to the exterior the sheet which has caused jam and returned.
In accordance with the present invention there is provided an image forming apparatus for forming images on a single sheet in plural number of times by feeding the sheet again to an image forming unit after an image is formed on one side of the sheet by said image forming unit, said image forming apparatus including: an apparatus body in which said image forming unit is incorporated, said apparatus body having a feeding unit which stores sheets fed into the image forming unit and a discharge section which receives sheets with images formed thereon; a primary passage formed within said apparatus body to guide each sheet from the interior of said feeding unit to said discharge section through said image forming unit; a secondary passage branching from a downstream end of said primary passage and extending up to an upstream end of the same passage to guide each sheet which has passed said image forming unit again up to said image forming unit, said secondary passage having a sheet removing area which functions to expose the interior of the secondary passage to the exterior of the apparatus body to permit the removal of the sheet present in the interior; a detecting means disposed in said secondary passage to detect a jammed sheet present in the secondary passage; a re-feed unit disposed within said apparatus body, forming a part of said secondary passage and provided with a drive means for driving each sheet present in the secondary passage forward toward the upstream end of said primary passage and also driving it backward toward the downstream end of the primary passage; and a control means which controls said drive means so that when said detecting means detects jam in the secondary passage of said re-feed unit, the jam sheet is moved backward up to said sheet removing area.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of an image forming apparatus according to an embodiment of the present invention;
FIG. 2 is a schematic view thereof with an upper body opened;
FIG. 3 is a block diagram showing a control means for driving a motor; and
FIGS. 4 and 5 are each a flow chart showing a control process.
DESCRIPTION OF THE PREFERRED EMBODIMENT
A copying machine according to a preferred embodiment of the present invention is based on electrophotography, whose body indicated at 10 comprises a lower body 11 and an upper body 12 pivotably mounted to the lower body 11. The upper body 12 of the copying machine body 10 is provided with a document bearing glass table 13 and a cover 14 for the table 13, the cover 14 capable of being opened and closed.
An image forming optical system 16 for forming an eletrostatic latent image on a photosensitive drum 15 mounted to the upper body 12 is well known, including a light source 17, mirrors 18, 19 and 20, a lens 21 and a mirror 22. It scans the document surface in the direction indicated by arrow A. A magnetic brush type developing device 23 for adhering toner to the electrostatic latent image formed on the photosensitive drum 15 is mounted to the upper body 12 in a position adjacent to the drum 15 which rotates in the direction of arrow B in FIGS. 1 and 2. Further, a transfer charger 24 for transferring toner to sheet and a separation charger 25 for separating the sheet from the photosensitive drum 15 are mounted to the lower body 11 in positions below the drum 15. The residual toner remaining on the outer peripheral surface of the photosensitive drum 15 after the transfer of the toner onto the sheet is removed by a cleaner 26. An eraser lamp 27 and a charger 28 are mounted to the upper body 12 in positions above the photosensitive drum 15.
The sheet after completion of the transfer is conveyed to a fixing device 31 mounted to the lower body 11 by means of an endless belt 30 mounted in the lower body 11. A suction pump 32 is mounted to the lower body 11 in a position below the belt 30 so that the sheet being conveyed on the belt 30 is stuck to the belt at a negative pressure.
To the left end portion of the lower body 11 are removably attached two feed cassettes 33 and 34 which contain copying sheets of different sizes. The feed cassettes 33 and 34 constitute a feed unit 35. The sheets in the feed cassette 33 are fed one by one by means of a feed roller 36 and the sheets in the feed cassette 34 also fed one by one by means of a feed roller 37. The feed rollers 36 and 37 are rotated selectively.
A pair of timing rollers 40 are mounted to the lower body 11 in positions adjacent to the transfer charger 24 to feed each sheet from the interior of either the feed cassette 33 or the cassette 34 to between the photosensitive drum 15 and the transfer charger 24, separation charger 25 in synchronism with the electrostatic latent image formed on the outer peripheral surface of the photosensitive drum 15. Onto the sheet thus fed by the timing rollers 40 is transferred a toner image by electric discharge of the transfer charger 24 and the sheet is then separated from the photosensitive drum 15 by virtue of AC discharge of the separation charger 25 and its own stiffness. Subsequently, the sheet is fed to the fixing device 31 while being stuck onto the belt 30 by the suction force of the suction pump 32 and the toner is fixed thereto under heating.
A sheet reversing unit 41 is attached to the right end of the lower body 11 in FIGS. 1 and 2. Attached to the sheet reversing unit 41 is a discharge tray 42 for receiving therein the sheet which has been subjected to the heat fixing in the fixing device 31.
A known type of an image forming unit 43 for forming an image on the sheet is constituted by the developing device 23, the photosensitive drum 15, the fixing device 31, etc. and the section from the timing rollers 40 in the image forming unit 43 up to the sheet reversing unit 41 serves as a primary passage 44.
Rollers 45 and 46 for conveying the sheet from the feed cassette 33 up to the timing rollers 40 are mounted to the lower body 11, and the upper body 12 is pivotable about the roller 45. With the upper body 12 pivoted to open as shown in FIG. 2, it is possible to effect maintenance and inspection of each component of the image forming unit 43 and sheet Sa which is causing clogging in the primary passage 44 can be removed.
Discharge rollers 47 for the delivery of the heat-fixed sheet to the discharge tray 42 are mounted in the sheet reversing unit 41, and guide plates 48 for guiding the sheet from the fixing device 31 to the discharge rollers 47 are mounted in the sheet reversing unit 41.
In the lower body 11 is mounted a re-feed unit 50 in a position below the image forming unit 43 for returning the sheet which has passed through the fixing device 31 again into the primary passage 44 formed within the image forming unit 43.
Within the sheet reversing unit 41 are provided a pair of feed rollers 51, guide plates 52 and 53 which are positioned between the feed rollers 51 and guide plates 48, and curved guides 54 and 55 which provide a connection between the feed rollers 51 and the re-feed unit 50. Further, for guiding the sheet which has passed through the fixing device 31 to the discharge tray 42, a change-over pawl 56 is provided within the sheet reversing unit 41 so as to be pivotable between a close position in which it is kept away from the passage defined by the guide plates 48 as indicated by a phantom line in FIG. 2 and a open position in which it projects into the passage defined by the guide plates 48 to close the passage.
For an image-formed sheet in the case of forming an image on one side of the sheet only once, or for a sheet which has been subjected to all of image forming steps in the case of forming images on one side of the sheet in plural number of times, the change-over pawl 56 is turned to the close position indicated by a phantom line in FIG. 2, whereby the sheet is discharged onto the discharge tray 42 with the discharge rollers 47. On the other hand, where there is made composite copying in which images are formed on one side of sheet in plural number of times, the sheet is fed to the re-feed unit 50 through the passage between the guide plates 52 and 53 and further through the passage between the guide plates 54 and 55 by turning the change-over pawl 56 to its open position shown in FIGS. 1 and 2.
The re-feed unit 50 has a pair of feed rollers 60 mounted to the lower body 11 in positions adjacent to the guide plates 54 and 55, a pair of feed rollers 61 mounted to the lower body 11 in positions below the timing rollers 40, and a pair of feed rollers 62 positioned between those rollers. Thus, it has three pairs of feed rollers. Between the feed rollers 60 and 62 are provided guide plates 63 and 64 at a predetermined spacing to guide the sheet therebetween, while between the feed rollers 62 and 61 are disposed guide plates 65 and 66 at a predetermined spacing to guide the sheet therebetween. Further, between the feed rollers 61 and the timing rollers 40 are disposed curved guide plates 67 and 68 in spaced relation to each other at a predetermined spacing to guide the sheet therebetween.
A secondary passage 69 which branches from the downstream end of the primary passage 44 and reaches the upstream end thereof is formed by the passages formed between the above guide passages and extending from the passage defined by the guide plates 52 and 53 up to the passage defined by the guide passages 67 and 68. The secondary passage 69 guides the sheet which has passed through the fixing device 31, toward the timing rollers 40. The feed of the sheet in the secondary passage 69 in the re-feed unit 50 is effected by means of a motor 70 which is mounted within the lower body 11 and connected to the feed rollers 60, 61 and 62 to drive those rollers.
The motor 70 is usually driven forward to advance the sheet in the secondary passage 69 toward the timing rollers 40. But in the event the sheet causes jam or clog in the secondary passage 69, the motor 70 is driven in reverse to move the sheet backward to the gap between the guide plates 54 and 55 which gap serves as a sheet removing area.
The guide plate 55 located in the lower position relative to the guide plate 54 is pivotable about a pin 71 mounted to the lower body 11. When the guide plate 55 is turned up to its position shown in FIG. 2 to open the secondary passage 69, the sheet causing the jam, indicated at Sb, which has been moved backward is removed.
A sensor S1 is disposed upstream of the timing rollers 40 in a position adjacent thereto to detect the position of sheet in the primary passage 44 or the secondary passage 69. Further, a sensor S2 is disposed at the outlet portion of the fixing device 31 and a sensor S3 is disposed at the downstream end of the re-feed unit 50, while a sensor S4 is disposed at the upstream end of the same unit. The sensors S1 to S4 are each constituted by a limit switch which turns ON upon arrival of the sheet front end at the switch and turns OFF upon arrival of the sheet rear end at the switch.
As shown in FIG. 3, which is a block diagram of a control section, the sensor S1 is connected to timers T1 and T2, and the sensors S2 and S4 are connected to timers T3 and T4, respectively, which start operation upon detection of sheet by the sensors. The timers T1 to T4 are each set to a time that is a little longer than the conveyance time corresponding to the sheet size required for the rear end of the sheet to pass any of the sensors S1, S2, and S4 which set the timer, after arrival of the front end thereof at the sensor. The said conveyance time differs depending on the sheet length. The sensors S1, S2, and S4, and the timers T1-T4 are connected to a jam signal generator 80 which detects a jam on the basis of signals provided from those sensors and timers. Thus, signals on the position of sheet which is passing through the primary passage 44 or the secondary passage 69 are input to the jam signal generator 80 and time-up signals are also input to the same generator from the timers. The sensor S3 is connected to the jam signal generator 80 so as to detect sheet present in the secondary passage 69.
The jam signal generator 80 is connected to a controller 82 for controlling the operation of the motor 70 which drives three pairs of rollers 60, 61 and 62 for the conveyance of sheet within the re-feed unit 50 and the operation of an indicator 84 which indicates in which portion of the image forming unit there occurred jam. The controller 80 has a timer T5 to which is set a reverse feed time for a jammed sheet. It not only provides a signal indicative of the jam position to the indicator 84 on the basis of a signal provided from the jam signal generator 80 but also makes controller 80 rotate the motor 70 in reverse only for the period of time set to the timer T5 to thereby convey the jammed sheet up to the passage formed between the guide plates 54 and 55.
The following description is now provided about the control procedure for the detection of jam a and the jam eliminating processing which are performed in the controller of the image forming apparatus of the present invention, with reference to the operation flow charts of FIGS. 4 and 5.
FIG. 4 is an operation flow chart in the foregoing jam detection. First, in step 100 there is made a judgment as to whether the sensor S1 is just turned on or not. As a result, if it is judged that the front end of sheet has reached the sensor S1, the timer T1 is set in step 101. Then, if count-up of the timer T1 is confirmed in step 102, judgment is made in step 103 as to whether the sensor S1 is just turned off or not. The result is NO if the rear end of the sheet has not passed the sensor S1, then execution passes to step 104, in which the jam signal generator 80 provides a jam signal Jam 1 to the controller 82 and thereafter execution returns to a main routine (not shown). On the other hand, the result of the judgment in step 103 is YES if the rear end of the sheet has passed the sensor S1 and in this case the timer T2 is set in step 105. Then, if count-up of the timer T2 is confirmed in step 106, judgment is made in step 107 as to whether the sensor S2 is just turned on or not. The result is NO if the front end of the sheet has not reached the sensor S2 and in this case execution passes to step 108, in which the jam signal generator 80 provides a jam signal Jam 1 to the controller 82 and thereafter execution returns to the main routine. On the other hand, if the sheet front end has arrived at the sensor S2, the result of the judgment in step 107 is YES and in this case the timer T3 is set in step 109. Then, if count-up of the timer T3 is confirmed in step 110, judgment is made in step 111 as to whether the sensor S2 is just turned off or not. The result is NO if the rear end of the sheet has not passed the sensor S2 and in this case execution passes to step 112, in which the jam signal generator 80 provides a jam signal Jam 2 to the controller 82 and thereafter execution returns to the main routine. On the other hand, the result of the judgment in step 111 is YES if the sheet rear end has passed the sensor S2. In this case, judgment is made in step 113 as to whether the change-over pawl 56 is open as shown in FIGS. 1 and 2 or not, that is, whether the sheet has been subjected to the first copying in a composited copying mode or not, and if the result of this judgment is YES, judgment is made in step 114 as to whether the sensor S4 is just turned on or not. As a result, if it is judged that the front end of the sheet has arrived at the sensor S4, the timer T4 is set in step 115. Then, if the count-up of the timer T4 is confirmed in step 116, judgment is made in step 117 as to whether the sensor S1 is just turned on or not. The result is NO if the sheet rear end has not passed the sensor S1 and in this case execution passes to step 118, in which the jam signal generator 80 outputs a jam signal Jam 3 to the controller 82 and thereafter execution returns to the main routine. If the result of the judgment in step 117 is YES, this means that the conveyance of the sheet has been effected without causing jam, so the above jam detecting processing is terminated and execution returns to the main routine.
When the jam signal Jam 3 is output from the jam signal generator 80 in the step 118, the controller 82 checks whether the each of sensors S1, S3 and S4 are on or off through the jam signal generator 80 and takes in the result as a 3-bit signal for more detailed judgment on the jam portion.
In FIG. 5, which is an operation flow chart in the jam eliminating processing, first in step 140 the controller 82 judges a jam signal has been provided from the jam signal generator 80 and if the answer is affirmative, then in step 141 the controller turns off the motor 70 which is for the conveyance of sheet in the re-feed unit 50. Then, in step 142 the controller 82 judges whether the jam signal is Jam 3 or not and if the result is NO, judgment is made in step 143 as to whether the jam signal is Jam 2 or not. If the result of the judgment in step 143 is YES, then in step 144 there is made indication of Jam 2 on the indicator 84. On the other hand, if the result of the judgment in step 143 is NO, the controller 82 causes the indicator 84 to indicate Jam 1 in step 145 and thereafter execution returns to the main routine. If it is judged in step 142 that the jam signal is Jam 3, the controller 82 refers to the 3-bit signal indicating the state of the sensors S1, S3 and S4 which it has taken in through the jam signal generator 80 for more detailed judgment on the jam portion, and judges whether the said signal is "001" or not, that is, whether the sensors S1, S3 and S4 are OFF, OFF and ON, respectively or not. This is a judgement as to whether the rear end of the jam sheet is positioned in the spacing between the guide plates 54 and 55 which spacing is a sheet removable area. If the result of this judgment is YES, the controller 82 causes the indicator 84 to indicate Jam 3 immediately in step 147 and thereafter execution returns to the main routine. If the result of the judgement in step 146 is NO, it follows that the foregoing 3-bit signal is "010" or "110", that is, the sensors S1, S3 and S4 are OFF, ON and OFF, respectively or ON, ON and OFF, respectively. In these cases, the jam sheet completely gets into the passage in the re-feed unit 50 or into the passage formed between the guide plates 67 and 68 which passages are sheet unremovable areas of the secondary passage 69, so in step 148 the controller 82 causes the motor 70 to rotate in reverse to move the sheet in reverse toward the inlet of the re-feed unit 50. Then, judgment is made as to whether the sensor S4 is just turned on or not, and while the result of the judgment is NO, the processings of steps 148 and 149 are repeated to continue the reverse feed of the jammed sheet. And when the sensor S4 is turned ON by the rear end of the jammed sheet thus fed reverse, the controller 82 sets the timer T5 in step 150 which timer is provided in the interior of the controller. Then, when the count-up of the timer T5 is confirmed in step 151, the controller 82 turns OFF the motor in step 152. By the processings so far performed the rear end of the jam sheet is moved in reverse up to the spacing formed between the guide plates 54 and 55 which spacing is the foregoing removable area. Then, in step 153 the controller 82 causes the indicator 84 to indicate Jam 3 and execution returns to the main routine.
To sum up, when the sensor S1 does not turn OFF even upon count-up of the timer T1, or when the sensor S2 does not turn ON even upon count-up of the timer T2 after turning OFF of the sensor S1, it is judged that a jam Jam 1 occurred before or behind the sensor S1 or between the sensors S1 and S2. And when the sensor S2 does not turn OFF even upon count-up of the timer T3 after turning ON of the sensor S2, it is judged that a jam Jam 2 occurred before or behind the sensor S2. Thus, in the event of jams (Jam 1) and (Jam 2), these jams are occurring in the primary passage 44, so the operator opens the upper body 12 of the copying machine body 10 as shown in FIG. 2 to open the primary passage 44, whereby the sheet indicated at Sa in FIG. 2 can be removed. The indicator 84 indicates to this effect alone.
Further, when the sensor S1 does not turn ON even upon count-up of the timer T4 after turning ON of the sensor S4, it is judged that a jam (jam 3) occurred in the secondary passage 69. In this case, the motor 70 rotates reverse whereby the jammed sheet is moved back until its rear end reaches the spacing between the guide plates 54 and 55. Consequently, as shown in FIG. 2, the operator can open the guide plate 55 and remove the sheet indicated at Sb. Thus, it is no longer necessary to provide a special space for removing the sheet which is causing jam in the secondary passage 69 and so it is possible to afford a copying machine smaller in size.
Particularly, in the event of a jam, there trouble occurs at the front end of sheet, so if the sheet is further moved in the conveyance direction, the jam will be promoted, but in the present invention, the sheet rear end free of trouble is moved backward as the front end, so it becomes possible to return the jam sheet certainly up to a predetermined position and discharge it to the exterior easily from that position.
The image forming apparatus of the present invention is not limited to the above embodiment. Various modifications may be made within the scope of the gist of the invention. For example, the paired timing rollers 40 may be rendered capable of contacting with and moving away from each other so that in the case of reverse feed of the jam sheet in the secondary passage 69, the rollers 40 are moved away from each other, the load applied to the motor 70 when reverse rotated can be reduced even when the front end of the sheet has reached between the rollers 40.
Moreover, although in the above embodiment there is used the motor 70 for driving only the roller pairs 60, 61 and 62 located in the re-feed unit 50, there may be utilized a main motor (not shown) incorporated in the apparatus body 10 to drive those roller pairs. In this case, a mechanical clutch is used to rotate the roller pairs 60, 61 and 62 forward and reverse. In the illustrated apparatus, moreover, the guide plate 55 is opened to discharge a jammed sheet from the interior of the secondary passage 69 to the exterior, but the guide plate 64 or 66 may be opened for the same purpose.
Further, although the illustrated copying machine is for composite copying, the present invention is also applicable to both-side copying machines as previously noted. | An image forming apparatus having a primary passage extending from a feeding unit which stores sheets up to a discharge tray which receives sheets with images formed thereon through an image forming unit which forms images on the sheet, and a secondary passage for returning each sheet which has been image-formed within the image forming unit to an upstream end of the primary passage from a downstream end thereof to form another image on the already image-formed side of the sheet or on the opposite side thereof. The secondary passage is formed so that in the event of jam or sheet therein, a portion of the secondary passage is exposed to the exterior by means of a guide plate capable of being opened and closed. Jam of sheet in the secondary passage is detected by a sensor and the jammed sheet is reverse fed up to the above guide plate by a drive which is for the conveyance of sheet in the secondary passage, then the guide plate is opened to permit removal of the thus reverse-fed sheet to the exterior of the apparatus. | 8 |
This application is a file wrapper continuation of U.S. application Ser. No. 07/699,187, filed May 13, 1991, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a camcorder, i.e., a video camera integrally incorporating a video cassette recorder (VCR). More particularly, the present invention relates to a camcorder having a loudspeaker function.
2. Description of the Prior Art
In the past, there has been commonly used a camcorder comprising only a simple microphone for receiving an external sound to enable to record it on a video tape through sound recording means arranged in the camcorder when taking a picture thereby. In such a camcorder having the microphone provided only for a recording of the sound, a photographer must communicate with an actor or a person to be photographed by his live voice, if necessary. The prior camcorder is therefore disadvantageous in that when taking a picture at great distance or in a crowded place, the photographer must shout to the actor in order to send his message to the actor.
SUMMARY OF THE INVENTION
In view of the aforesaid problem of the prior art, it is an object of the present invention to provide a camcorder having a folded and unfolded microphone mounted for movement in one side of a body of the camcorder and additionally including a loudspeaker function, thus enabling a photographer to communicate with an actor or a person to be photographed by the speaker when taking a picture.
To achieve the above object, there is provided according to one aspect of the present invention a camcorder being a video camera integrally incorporating a video cassette recording function, and comprising input means for receiving an external sound and converting it into an electric signal, sound processing means coupled to a speaker and outputting an amplified sound through the speaker, and switching means actuated to selectively send the input sound signal to the sound processing means or to the recording means of the camcorder, thereby amplifying and transmitting a voice message of a photographer or a director or effecting a tape recording operation by the recording means.
According to another aspect of the present invention, there is provided a camcorder according to the above aspect, wherein the sound input means comprises a microphone which may be folded and adjusted in position, and in order to effect folding and position adjusting operations of the microphone, the camcorder comprises a recess formed in one side surface of a body of the camcorder for receiving the microphone therein, a guide rail secured to one side of the recess, a slider having a semicircular support plate with a central boss and slidably movable along the guide rail, and a microphone support piece holding for rotation the microphone and rotatably mounted on the central boss of the support plate.
BRIEF DESCRIPTION OF THE DRAWINGS
Many other advantages and features of the present invention will become apparent from the following description of a preferred embodiment of the invention with reference to the accompanying drawings, in which:
FIG. 1 is a block diagram illustrating the construction of the present invention;
FIG. 2 is a side elevational view of a camcorder embodying the present invention;
FIG. 3 is an exploded perspective view of a microphone position adjusting device according to the present invention;
FIG. 4 is a sectional view of the device of FIG. 3 in the assembled position; and
FIG. 5 is a fragmentary plan view of the device shown in FIG. 4.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring first to FIG. 1, there is shown a block diagram of the preferred embodiment of the present invention in which input means(1), such as a microphone, receives an external sound and converts it into an electric signal, and then, the electric signal is selectively sent by an operation of switching means(2) to sound recording means(3) which functions to record the sound on a video tape, or to sound processing means (4) which functions to amplify the sound and send the amplified sound to a speaker(5) and a speaker jack(6) for an extra speaker to transmit it to the exterior. The speaker(5) and the speaker jack(6) are coupled to the sound processing means(4) in parallel with each other in such a manner that the speaker jack (6) also serves as a switch for turning off the speaker(5) built in a camcorder when the extra speaker is connected to the camcorder through the jack, and turning on the speaker(5) when the extra speaker is disconnected from the camcorder.
FIG. 2 shows the camcorder according to the present invention having the components as shown in FIG. 1 arranged in its body(10). A microphone(11) is foldably mounted as input means in a recess(10a) formed in one side surface of the body(10), and the built-in speaker(5) and the speaker jack(6) for a separate speaker are disposed at appropriate positions of the body(10). Therefore, the photographer's voice input through the microphone(11) may be amplified and then transmitted to the exterior either through the built-in speaker(5) or the separate speaker connected to the camcorder through the jack(6). At this time, the sound input through the microphone(11) is selectively sent by a switching operation of the switching means to the speaker(5) via the sound processing means, or to the sound recording means within the body(10) to be recorded on a video tape. More particularly, the microphone(11) is of a right-angled shape and so arranged that it may be inserted into and taken out from the recess(10a) of the body(10) and also adjusted in position according to positions of the photographer's mouth.
FIG. 3 shows the arrangement for adjusting a position of the microphone, which comprises a T-shaped guide rail(12) fixedly secured to one side of the recess(10a) formed in one side surface of the body(10) for receiving the microphone(11), a slider(14) having a semicircular support plate(13) with a central boss(15) and slidably engaged with the guide rail(12), and a microphone support piece(16) having an engaging hole or groove(16a) and rotatably mounted on the central boss(15) of the support plate(13). In addition, a resilient leaf spring(17) is interposed between the guide rail(12) and the slider(14), and a circular plate(19) having a central hole and a plurality of engaging projections(18) is mounted on the central boss(15) of the support plate (13) below the microphone support piece(16). As a result, frictional contact between the guide rail(12) and the leaf spring(17) secured to the back side of the slider(14) and an engagement of the projection(18) of the circular plate(19) with the engaging groove(16a) of the microphone support piece(16) cause the microphone to be movable without rocking and stably held in a specific desired position.
The circular plate(19) mounted on the central boss(15) of the support plate(13) is fixedly secured to the support plate(13) by a screw fastened through a hole(19a) of the circular plate to another boss(20) of the support plate, whereby the circular plate is prevented from turning along with the microphone support piece(16) during rotation of the support piece. Then, a cover(21) is mounted on the top of the microphone support piece(16) with a guide rod(11a) of the microphone(11) rotatably disposed between the support piece(16) and the cover(21).
The various elements of the microphone position adjusting device as described above is assembled as shown in FIG. 4.
Use of the microphone will now be described. First, during carry and storage of the camcorder, the microphone(11) is folded or inserted into the recess(10a) of the body(10) of the camcorder, as shown in FIG. 2. In this state, when taking a picture, the user takes out the microphone from the recess(10a) and positions it at a convenient position near his mouth. The positioning of the microphone(11) is carried out by moving it in the horizontal direction by the slider(14) sliding along the guide rail(12), and rotating it by turning the microphone support piece(16) about the central boss(15) of the support plate(13) to determine an angular position of the microphone. Then, the microphone(11) of a right-angled shape may be adjusted in position to be located near photographer's mouth regardless of a personal shape of the photographer by rotating the microphone itself between the microphone support piece(16) and the cover(21). When the position adjustment of the microphone has been complated, the microphone is held in a fixed position by resiliency of the leaf spring (17) interposed between the guide rail(12) and the slider(14) and an engagement of the projection(18) of the circular plate(19) with the engaging groove(16a) of the microphone support piece(16), as described previously.
In addition, as shown in FIGS. 3 and 5, a contact switch(25) is disposed as the switching means within the support plate(13) of the microphone position adjusting mechanism to carry out a switching operation according to the positions of the microphone(11) taken out from and withdrawn into the recess(10a) of the body(10) of the camcorder, without need of a separate external switch. More particularly, the contact switch(25) is mounted within the support plate(13) at a position conforming to the position of the microphone completely withdrawn into the recess(10a) of the body(10). Therefore, the switch is turned off in the condition wherein the microphone(11) has been taken out from the recess(10a) as indicated by the solid line in FIG. 5, and turned on in the condition wherein the microphone has been inserted into the recess(10a) as indicated by the dotted-and-dashed line in FIG. 5. Thus, when the switch(25) is turned on by the microphone withdrawn into the recess, a sound is recorded on the video tape in the camcorder along the route comprising the input means(10) and the sound recording means(3) of FIG. 1. To the contrary, when the switch(25) is turned off, a sound is amplified and transmitted to the exterior through the route comprising the input means(1), the sound processing means(4) and the speaker(5) of FIG. 1.
As discussed above, the present invention provides an efficient camcorder which may selectively effect a sound amplifying function enabling the photographer to easily communicate with the actor or the person to be photographed when taking a picture at great distance or in a crowded place, and its own tape recording function by changing a position of the microphone. | A camcorder having a loudspeaker function has a recording device and includes an input device for receiving an external sound and converting it into a first electric signal and for receiving a sound from a user and converting it into a second electrical signal. The input device is preferably movable between an extended position and a retracted position. Sound processing means are provided and coupled to a speaker for outputting an amplified sound through the speaker. A switching device is provided for sending the first electrical signal to the recording device when the second input device is in the retracted position and for sending the second electrical signal to the sound processing device when the second input device is in the extended position. | 8 |
BACKGROUND OF THE INVENTION
This invention relates to an apparatus for carrying out by automatic control the process of treating waste gases containing nitrogen oxides (NO x ) and sulfur dioxide (SO 2 ) by irradiation and with the addition of ammonia (NH 3 ). An electron beam accelerator is generally used as a radiation source in the practice of this process.
Among the known waste gas purification processes which have been developed heretofore, there is one in which NH 3 is added to the waste gas containing NO x and SO 2 and the same gas is irradiated with electron beams to thereby convert NO x and SO 2 contained therein as small amounts of toxic gaseous components into minute solid particles which can be removed from the waste gas by a dust collector placed in the later stage. This process is carried out by introducing waste gas to which NH 3 has been added to a reactor, where the waste gas is irradiated through the "window for irradiation" of the reactor to convert the small amounts of toxic gaseous components to aerosol and then carrying the thus irradiated waste gas into a dust collector such as an electrostatic precipitator to thereby separate said aerosol.
For the successful practical operation of this process, it is required to control the amount of NH 3 to be added to the waste gas and also to control the dose rate of electron beams so that both said amount and said dose rate may meet the concentrations, which vary at every moment, of NO x and SO 2 of the waste gas to be treated.
Namely, for the continuous practical operation of this type of process, it is important to maintain the respective concentrations of NO x , SO 2 and NH 3 of the treated waste gas within a certain limited range and thereby to minimize the consumption of NH 3 and the output of electron beams.
SUMMARY OF THE INVENTION
Thus, it is an object of this invention to provide an apparatus which enables the practical operation of said type of waste gas treating process in such a manner that the various conditions mentioned above may fully be satisfied.
The apparatus of this invention contains as its major components a reactor and a dust collector which are connected with each other in series, and it also contains additional components including an electron beam accelerator for irradiating the waste gas within the reactor with electron beams, equipment for providing ammonia to the waste gas which is introduced into the reactor and two independent automatic controlling units for controlling, respectively, according to the operational conditions, the amount of NH 3 to be added to the waste gas fed to the reactor and the amount of beam current in the electron beam accelerator.
BRIEF EXPLANATION OF THE DRAWINGS
FIG. 1 is to illustrate the component parts and the controlling system of the electron beam irradiating waste gas treatment apparatus of the present invention and the operational flow chart of the waste gas treating process using the same apparatus.
FIG. 2 is a graph representing the relationship between the amount of NH 3 added and the respective NO x , SO 2 and NH 3 concentrations of the gas at the reactor outlet determined under the specified conditions.
FIG. 3 is a graph representing the relationship between the flow rate of waste gas (Nm 3 /hr) and the respective NO x , SO 2 and NH 3 concentrators of the gas at the reactor outlet (ppm) determined under the specified conditions.
FIG. 4 is a graph representing the absorbed dose (Mrad) and the NO x concentration of the gas at the reactor outlet determined under the specified conditions.
FIG. 5 is a graph representing the relationship between the absorbed dose (Mrad) and the SO 2 concentration of the gas at the reactor outlet (ppm) determined under the specified conditions.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the attached drawing (FIG. 1), the reactor 7 is a vessel having an inlet for introducing untreated waste gas, a window through which electron beams pass and an outlet for discharging the irradiated waste gas.
The waste gas introduced in the vessel through the inlet thereof is subjected to irradiation with electron beams coming from the electron beam accelerator 6 and passing through the window given in the vessel. An appropriate amount of ammonia is also introduced into the reactor via the valve for adjusting the flow rate of NH 3 , 14, which is controlled by the NH 3 flow rate-controller, 12.
The waste gas which has passed through the reactor is carried to the dust collector (such as an electrostatic precipitator) 8, wherein the waste gas is purified by the separation therefrom of the aerosol contained therein. The gas outlet of the reactor is connected to the gas inlet of the dust collector.
Each of the measurements of the NO x concentration, the SO 2 concentration and the flow rate of the waste gas before entering the reactor (hereinafter simply referred to as "gas at the inlet") determined, respectively, by the NO x analyzer 1, the SO 2 analyzer 2 and the flowmeter 3 is changed to an output signal which corresponds to each of said measurements. These signals are sent to the arithmetic unit (for calculating the desired amount of NH 3 to be added) 4.
Upon receipt of these signals, the arithmetic unit 4 calculates the proper amount of NH 3 to be added to the gas at the inlet and it sends the output signal corresponding to the calculated value to an ammonia-providing device which includes a flow rate control device for NH 3 12 to control the amount of ammonia. On the other hand, the signal dispatched from the waste gas-flowmeter 3 is also sent to the arithmetic unit (for calculating the desired amount of electron beam current) 5, which calculates based on this signal the proper amount of current and the output signal corresponding to this current is sent to the electron beam accelerator. The strength of electron beams is controlled based on this signal. The system including the above-mentioned series of various controlling circuits is herein referred to as the first controlling system in the apparatus of this invention. In the normal state of the operation, this first controlling system actuates to maintain the proper operation.
The process of the present invention is characterized in that it contains the second controlling system which is independent from said first controlling system. The second controling system monitors the concentrations of NO x , SO 2 and NH 3 of the waste gas which come out of the outlet of the reactor (this gas will hereinafter be simply referred to as the "gas at the outlet") and it operates in preference to said first controlling system only when at least one of said three concentrations has a value outside of the predetermined range of the concentration, namely only when an unusual change is observed in the operational process. Namely, the second controling system does not work when the operation is normal. In FIG. 1, the reference numbers 9, 10 and 11 represent the NO x analyzer, the SO 2 analyzer and the NH 3 analyzer, respectively and these constitute part of the second controlling system. In the case of FIG. 1, the analyzers are placed in such a manner that it is possible to analyze the gas coming from the outlet of the dust collector. However, the analyzers can be placed at any place so long as they are placed downstream of the reactor.
It is possible to use one and the same arithmetic unit for both the first and the second controlling systems. Thus, it is unnecessary to employ another unit for the second controlling system, though of course two units can be used separately for respective purposes if desired. The constitution and the function of the second controlling mechanism are the same as those of the first controlling mechanism except that it can send signals corresponding to the concentrations of NO x and SO 2 of the gas at the outlet to the arithmetic unit (for electron beam current) 5 and also can send the signal corresponding to the concentration of NH 3 of the gas at the outlet to the arithmetic unit (for the amount of NH 3 ) 4.
The actual controlling mechanism by the first controlling system works as follows.
(1) Control of the amount of NH 3 to be added:
Assuming that the concentrations of NO x and SO 2 of the gas at the inlet be a NO .sbsb.x and b SO .sbsb.2, respectively, and the amount of the waste gas be Q, the amount of NH 3 to be added, A NH .sbsb.3, can be calculated by the following equation:
A.sub.NH.sbsb.3 =K·Q (a.sub.NO.sbsb.x +2 b.sub.SO.sbsb.2) . . . (1)
wherein K represents the constant of NH 3 addition, which may vary depending on the permitted limits specifically given for the concentrations of NO x , SO 2 and NH 3 , respectively, of the gas at the outlet.
(2) Control of electron beam current:
Depending on the change in the amount of gas at the inlet the calculation is effected according to the following equation:
I=C·TD·Q . . . (2)
and by the results thereof, the electron beam current is controlled, wherein I represents the electron beam current, TD represents the absorbed dose and C represents a device constant which is determined by the electron beam energy (eV) and the shape of the reactor.
The actual controlling mechanism by the second controlling system works as follows.
The concentrations of NO x , SO 2 and NH 3 of the gas at the outlet are always being monitored, and when at least one of these concentrations is observed to have a value outside of the predetermined permitted range, a judgement mechanism works to give the instructive signal to start the second controlling mechanism functioning in preference to the first controlling system. This controlling mechanism works according to the following procedures.
(1) In the cases when the concentration of NH 3 of the gas at the outlet is outside of the predetermined permitted range:
(a) The amount of NH 3 to add to the gas at the inlet is changed so that the concentration of NH 3 in the gas at the outlet may be kept within the predetermined permitted range. For example, if the NH 3 concentration of the gas at the outlet exceeds the predetermined permitted range, the amount of NH 3 to add is decreased until the NH 3 concentration of the gas at the outlet decreases to the upper limit of said predetermined permitted range of the NH 3 concentration. In the reverse case, the amount of NH 3 to add is increased until the NH 3 concentration of the gas at the outlet reaches the lower limit of said predetermined permitted range.
(b) After making the adjustment mentioned in the above item (a), if at least one of the NO x concentration and the SO 2 concentration of the gas at the outlet is outside of the predetermined permitted concentration range, the amount of electric current is adjusted so as to bring the concentrations of said components within the predetermined permitted range.
For example, if at least one of the NO x concentration and the SO 2 concentration of the gas at the outlet exceeds the predetermined permitted range for each of them, the amount of beam current is increased so that the NO x concentration or the SO 2 concentration of the gas at the outlet may be within the range of the predetermined permitted range. In the reverse case, the amount of beam current is decreased in the same manner as mentioned above.
(c) By repeating the adjustments mentioned in the above items (a) and (b), the amount of addition of NH 3 and the amount of electron beam current are adjusted until at last the concentrations of all components fall within the predetermined permitted range for the respective components.
(2) In the cases when the NH 3 concentration of the gas at the outlet is within the predetermined permitted concentration range and at the same time at least one of the NO x concentration and the SO 2 concentration of the gas at the outlet is outside of the predetermined permitted range for the respective components.
In these cases, one can repeat the procedures as mentioned in the abovementioned items (1)-(b) and (c).
As is obvious to those skilled in the art, the so-called "PID action" (proportional integral and derivative action) method can be employed as the second controlling system in the present invention.
One important advantage of using the apparatus of the present invention is that the time lag between the measurement of NO x and SO 2 concentrations and the flow rate of the waste gas and the adjustment of the operational conditions based on the results of said adjustment has been decreased remarkably as compared with when the prior art apparatus is used. This is because in the present invention only the first controlling system operates under the normal operational conditions based on the measurements of NO x and SO 2 concentrations and the flow rate of the waste gas determined at or before the inlet of the reactor, while in the prior art only the "feed back" type controlling system (which corresponds to the second controlling system in the present invention) is always working, and with such system substantial time lag is inevitably required with respect to the relationship between said measurement and said adjustment.
FIGS. 2 through 5 show some examples of the experimental results obtained by treating waste gas by making use of the apparatus of the present invention.
FIG. 2 is a graph which shows the relationship between the amount of NH 3 to add (in terms of "a constant for the addition of NH 3 " in the equation) and each of the concentrations of NO x , SO 2 and NH 3 of the gas at the outlet. The concentrations of NO x and SO 2 of the gas at the inlet were 200 ppm and 200 ppm, respectively. It is understood that in the embodiment as shown in FIG. 2, good results are obtained when the "NH 3 addition constant" is around greater than 0.95.
The reaction products obtained by the desulfurization and denitration process using the apparatus of the present invention are ammonium sulfate and ammonium sulfate-nitrate. It has been clarified that SO 2 contained in waste gas reacts with 2 equivalents of NH 3 to form ammonium sulfate or the ammonium sulfate component in ammonium sulfate-nitrate, and the NO x component in waste gas reacts with 1 equivalent of NH 3 to form the ammonium nitrate component in ammonium sulfate-nitrate. As is evident from the above explanation, it has been known that the reaction products are ammonium sulfate and ammonium sulfate-nitrate. Hence it is understandable that the amount of NH 3 to add to the waste gas depends on the total of (NO x content+2×SO 2 content).
It is also understood that based on the experimental results as shown in FIG. 2, the "constant for the addition of NH 3 " can be determined from the values of the given permitted limits of the concentrations of NO x , SO 2 and NH 3 of the gas at the outlet which have been determined in advance. Thus, the "constant for the addition of NH 3 " given as "K" in the preceding equation (1) can be determined and according to this equation it is possible to calculate the amount of NH 3 to add to the waste gas in the course of operation.
FIG. 3 is a graph representing the relationship between the flow rate of waste gas Q and the NO x content, the SO 2 content and the NH 3 content each of the gas at the outlet for the cases operated under the conditions of both the NO x content and the SO 2 content of the gas at the inlet being 200ppm, the constant (coefficient) for the addition of NH 3 being 1.0 and I/Q being approximately equal to (≈) 0.01 mA/Nm 3 /hr. FIG. 3 shows that when NO x content and the SO 2 content each of the gas at the inlet is constant and only the flow rate of waste gas varies, the degree of removal of SO 2 and NO x can be held constant, providing the beam current of electron beam accelerator per unit amount of gas is kept constant. Namely, it has been confirmed that in the process of treating waste gas by making use of the apparatus of the present invention, satisfactory operation can be ensured only by adjusting the amount of electron beam current in proportion to the varying amount of waste gas, providing the amount of waste gas is the only one variable in the operation of the process. The current required can be determined according to the equation:
I=C.sub.1 Q
wherein C 1 is a constant.
FIG. 4 is a graph representing the relationship between the absorbed dose (Mrad) and the NO x content (ppm) of the gas at the outlet determined with respect to each of the cases wherein waste gases containing 200 ppm of SO 2 and 100 ppm or 200 ppm of NO x are treated under the conditions including the condition that the constant for the addition of NH 3 is equal to 1.0. It is obvious from FIG. 4 that the necessary absorbed dose or total dose (TD) varies depending on the NO x and SO 2 concentrations of the gas at the inlet, namely, the lower the NO x and the SO 2 concentrations, the less the required absorbed dose. By reference to FIG. 4, the curve 1 represents the case wherein the NO x concentration is 100 ppm and the curve 2 the case wherein the NO x concentration is 200 ppm.
FIG. 5 is a graph representing the relationship between the absorbed dose (Mrad) and the SO 2 concentration of the gas at the outlet determined with respect to each of the cases wherein waste gases containing 200 ppm of NO x and 100 ppm or 200 ppm of SO 2 are treated under the conditions including the condition that the constant for the addition of NH 3 is equal to 1.0. It is obvious, as in the case of FIG. 4, that the lower the concentrations of such components, the smaller the absorbed dose that is necessary.
By reference to FIG. 5, the curve 3 represents the case wherein the SO 2 concentration is 100 ppm and the curve 4 the case wherein the SO 2 concentration is 200 ppm.
The total dose (TD) means the dose of radiation absorbed by the waste gas. It has been revealed that there exists the following relationship between the amount of waste gas and the electron beam current:
TD=C.sub.2 ·(I/Q)
wherein C 2 is a constant. From the equation given above, the electron beam current, I, can be obtained according to the following calculation:
I=k·TD×Q
wherein k=1/C 2 . It is evident from this equation that if the electron beam current I is always being adjusted depending on the varying concentrations of NO x and SO 2 , the operation of treating waste gas can be maintained constant. In fact, however, the NO x and SO 2 concentrations of various waste gases generated from iron making plants, power plants, etc., change every second depending on the changes in the sulfur content of the fuel used, burning conditions of the fuel and other operational conditions. In addition the changing pattern is by no means simple. For example, sometimes the concentration of both NO x and SO 2 changes, while sometimes only either of said two changes. Thus, the equation for calculating the necessary electron beam current based on the signals corresponding to the NO x and SO 2 concentrations of the gas at the inlet is generally complicated and the arithmetic unit useful for such purpose is costly. In contrast, any of the equations of operation used in the controlling system of the apparatus of this invention is relatively simple, and yet, by properly selecting depending on the operational conditions either of said first and second controlling system, it is possible to control the operation in such a manner that always the minimum necessary amount of NH 3 and amount of beam current are provided.
In actually designing the apparatus of treating waste gas of the present invention, the following matters should also be taken into consideration so that the most rational design may be ensured.
(1) Each of the first and the second controlling systems independently contains both an arithmetic unit for calculating the necessary amount of ammonia and another arithmetic unit for calculating the necessary amount of beam current.
Alternatively, each of the two arithmetic units, one for ammonia and one for beam current, respectively, can serve a double purpose, namely, each of the two units for the respective purposes can serve the same purpose for both in the first and in the second controlling systems.
(2) The inlet of NH 3 can be given in any portion of the duct for waste gas so long as it is placed downstream of the points at which the NO x content, the SO 2 content and the flow rate of the waste gas at the inlet of the reactor are measured but upstream of the inlet of the dust collector.
(3) The judging (or sensing) system can be placed in any of the following four positions.
(i) When a pair of the arithmetic units 4 and 5, one for controlling the amount of ammonia and one for controlling electron beam current, respectively, are used each for a double purpose to serve both in the first and in the second controlling systems, the judging system is to be set in each of the units 4 and 5.
(ii) When a pair of the arithmetic units 4 and 5 are used in the first controlling system and another pair of the arithmetic units 4' and 5' are used in the second controlling system, respectively, the one judging system should be set in each of the units 4' and 5' placed in the second controlling system.
(iii) The judging systems can be equipped independently to make them operate in preference to the first controlling system.
(iv) The fourth alternative is to install an electron beam current judging system in the NO x analyzer for the gas at the outlet 9, to install another electron beam current judging system in the SO 2 analyzer for the gas at the outlet 10 and to install an ammonia content judging system in the NH 3 analyzer for the gas at the outlet 11.
IN the apparatus of the present invention, the first controlling system is an interlocking device which comprises (a) means for measuring, respectively, the concentrations of NO x and SO 2 as well as the flow rate of the waste gas to be introduced into the reactor; (b) means for converting the measured values into output signals which correspond to said measurements, respectively; (c) an arithmetic unit for ammonia which can receive said output signals and calculate therefrom the proper amount of ammonia to add to the waste gas through the NH 3 inlet and send the output signal corresponding to said proper amount of NH 3 , said NH 3 inlet being situated in the passage of the waste gas downstream of the points at which the concentrations of NO x and SO 2 as well as the flow rate of the waste gas are measured but upstream of the inlet of the dust collector; (d) means for supplying ammonia which can receive the output signals from said arithmetic unit for ammonia to open and close a valve for supplying NH 3 in order to send the proper amount of ammonia to said NH 3 inlet; (e) an arithmetic unit for electron beam current which can receive the output signal corresponding to only the flow rate of the waste gas to be fed into the reactor to calculate the proper value of the electron beam current which is converted into the corresponding output signal to be sent to the electron beam accelerator; and (f) electron beam accelerator which can receive the signal from said arithmetic unit for electron beam and give electron beams at a proper dose rate to irradiate the waste gas inside the reactor.
The second controlling system is an interlocking device comprising (a) means for measuring the concentrations of NO x , SO 2 and NH 3 of the waste gas which has left the reactor; (b) means for converting these measured values into the respective corresponding output signals; (c) an arithmetic unit for ammonia which can selectively receive the signal corresponding to the concentration of NH 3 out of said three signals in order to calculate the proper amount of ammonia to add and send the output signal corresponding to said calculated value of ammonia; (d) means for supplying ammonia which can receive said signal from said arithmetic unit for ammonia to thereby open and close a valve given in the ammonia supplying passage in order to send the proper amount of NH 3 to said NH 3 inlet; (e) an arithmetic unit for electron beam current which can selectively receive the signals corresponding to the concentrations of NO x and SO 2 out of said signals in order to calculate the proper value of electron beam current and send the output signal corresponding to said calculated value to the electron beam accelerator and (f) an electron beam accelerator which can receive the signal from said arithmetic unit for ammonia to give electron beams at a proper dose rate to the waste gas inside the reactor.
The second controlling system mentioned above can operate according to the instructions from said judging mechanism in preference to the first controlling system, only when an abnormal change has been observed in the process, namely, when at least one of the concentrations of NO x , SO 2 and NH 3 of the waste gas in the downstream of the outlet of the reactor is outside of the predetermined range.
In the normal conditions, namely when all the concentrations of NO x , SO 2 and NH 3 of the gas at the outlet are within the predetermined range, only the first controlling system works and the second controlling system does not. | There is disclosed an apparatus for treating waste gas containing nitrogen oxides and sulfur dioxide by irradiation with electron beams with the addition of ammonia, which apparatus comprises a reactor having an inlet and an outlet for the waste gas and a window through which electron beams pass to irradiate the waste gas inside the reactor, an electron beam accelerator as a source of said electron beams and a dust collector which receives the irradiated waste gas and removes solid particles therefrom, characterized in that said apparatus further comprises two independently operating automatic controlling systems and a judging system; the first controlling system operates under normal conditions; the second controlling system operates only in the case of emergency when the judging system has detected abnormal changes with respect to the concentrations of NO x , SO 2 and NH 3 of the waste gas. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority of German Patent Application No. 102006041420.9, filed Sep. 4, 2006, the disclosure of which is hereby incorporated by reference in its entirety.
FIELD OF THE INVENTION
The present invention relates to a pump device having a first diaphragm pump head and a second diaphragm pump head hydraulically coupled thereto.
BACKGROUND OF THE INVENTION
Piston pumps may be used to deliver and/or recirculate viscous media having a high proportion of solids (suspensions) at high pressures of greater than 200 bar and high temperatures of greater than 300° C. However, they are only suitable in a limited way for an application of this type, because the solid components destroy associated seals of a piston in a relatively short time and cause scoring on a surface of the piston.
A possibility for avoiding these difficulties is to use diaphragm pumps. To implement delivery at the above-mentioned pressures, only designs having hydraulically driven diaphragms may be used. In turn, these may only be conceived for secure and interference-free operation in the cited temperature range with significant design and material technology outlay.
The use of plastic diaphragms made of PTFE, for example, is not possible, because plastic begins to flow significantly at the cited high pressure and high temperature. The use of metal diaphragms is possible in principle, but technical demands such as multilayered diaphragms having fracture signaling and an embodiment as a diaphragm oscillating freely in the product space having position control may only be implemented with great effort, see EP 0 085 725 A1.
Up to this point, pumps having a so-called remote valve head have been used as a measure against the high temperature strain. In such a design, a diaphragm pump operates as an upstream pulsator, which actuates the operating valve in the downstream remote valve head of the pump with the aid of the fluid to be delivered via a pipeline acting as a cooling line. In this way, the diaphragm pump may operate in the noncritical low temperature range up to approximately 150° C. However, it is disadvantageous that possible solid components of the fluid to be delivered may clog the pipeline between the upstream pulsator and the remote valve head and thus impair the delivery effect.
The high pressure of the fluid to be delivered results in a further problem. The piston rod force of oscillating displacement pumps, which results from the product of pressure and area, requires the use of very large pump drive assemblies in certain circumstances, which may be uneconomical in two regards for the required application. Firstly, significantly higher investment costs and secondly higher life cycle costs are connected thereto, which may be particularly distinguished by energy costs and outlay for wearing and replacement parts. The economic consideration of pump systems for recirculation having the boundary conditions cited above is especially of very great significance in methods for energy reclamation from biological wastes.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a pump device which may reliably and cost-effectively deliver viscose media having a high solid component at high pressures of greater than 200 bar and high temperatures of greater than 300° C.
The object is achieved by a first diaphragm pump head having two or an integral multiple of two fluid delivery chambers and diaphragms associated therewith, which are hydraulically coupled to a second pump head for driving the first diaphragm pump head, wherein the second pump head is a diaphragm pump head which has two additional fluid delivery chambers and two associated additional diaphragms, which are drivable by a double-acting piston, situated in the second diaphragm pump head, via associated diaphragm control chambers, and a refilling valve being connected to each of the diaphragm control chambers, and, using the refilling valves, the diaphragm control chambers being impinged temporarily, during the refilling procedure, which is controlled by the diaphragm position, by a diaphragm control pressure, which is greater than atmospheric pressure and less than the system pressure.
Advantageous embodiments of the present invention are described in the subclaims.
The pump device according to the present invention comprises a first diaphragm pump head having two or an integral multiple of two fluid delivery chambers and diaphragms associated therewith, which are hydraulically coupled to a second diaphragm pump head, the second diaphragm pump head having two additional fluid delivery chambers and additional diaphragms associated therewith, which are drivable by a double-acting piston via associated diaphragm control chambers, a refilling valve being attached to each of the diaphragm control chambers and the diaphragm control chambers being temporarily impinged by a diaphragm pressure, which is greater than atmospheric pressure, using the refilling valves.
Such a pump device is advantageous because at a time at which the refilling valve refills the diaphragm control chambers with a control fluid to compensate for unavoidable leakage of the control fluid, a brief pressure drop in the diaphragm control chambers down to atmospheric pressure, which has been typical up to this point in position-controlled diaphragms, for example, may be limited by the superimposed diaphragm control pressure, which is greater than the atmospheric pressure.
By using the pump device according to the present invention, a movement of the piston is possible at any time using a smaller force than in achievements of the object in the prior art, so that a delivery pressure may alternately be conducted into the particular diaphragm control chambers of the second diaphragm pump head and therefrom to the first diaphragm pump head to transport fluid through the first diaphragm pump head. Although the overall pressure in the first diaphragm pump head may be relatively high to deliver the fluid, it is possible to operate a pumping procedure using a relatively small force exerted on the piston and pressure differential thus generated. A situation thus arises as if the piston would exert the pressure increase directly in the first diaphragm pump head. It is possible due to the pump device according to the present invention that the piston may be driven by a drive assembly which may be designed for much smaller forces than in achievements of the object known up to this point, so that a significantly more cost-effective delivery at high temperatures and pressures in the first diaphragm pump head is achieved.
The pump device is preferably designed in such a way that the diaphragm control pressure approximately corresponds to a fluid pressure at the inlet of a fluid delivery chamber of the first diaphragm pump head. Therefore, the described brief pressure drop in the diaphragm control chamber of the second diaphragm pump head is nearly completely compensated for. In combination with a double-acting embodiment of the piston of the second diaphragm pump head, this has the result that the drive assembly for the piston only has to be designed for forces which approximately correspond to the pressure differential between the inlet and the outlet of a fluid delivery chamber of the first diaphragm pump head.
In the pump device according to the present invention, the diaphragm control pressure may preferably be adapted to the fluid pressure by a control circuit having associated sensors and actuators. In particular with an electronic control circuit, this allows an optimally tailored compensation of the described pressure drop and thus the prevention of pressure surges, which may exert a harmful reaction on the drive assemblies.
The diaphragm control pressure may be generated by a pump which is coupled in each case to a container for a diaphragm control chamber, each container having one of the refilling valves and each container being impinged by a static stagnation pressure by the pump. In such an embodiment, the pump is permanently in operation.
According to an alternative embodiment, the diaphragm control pressure may be generated by a controllable pump which feeds a pressure accumulator which is coupled in each case to a container for a diaphragm control chamber. The container is used in this case as a refilling reservoir. In this embodiment, it is possible that the pump is only in operation when the pressure accumulator falls below a predefined lower limiting pressure. The pump then operates until an upper limit pressure is again reached in the pressure accumulator (two-point regulation).
Furthermore, it is possible to provide a container in each case as a refilling reservoir of a control fluid for a diaphragm control chamber of the second diaphragm pump head, an adjustable throttle device being connected downstream from each container. In this case, the pump may be continuously in operation, so that continuous circulation of a control fluid is provided.
The construction of the pump device and its mode of operation are relatively symmetrical if the piston is implemented as a double-acting disk piston having diametrically opposite piston rods. In this case, the piston faces on both sides of the disk piston having identical sizes, so that during an intake stroke or pressure stroke, the same pressure change and the same volume displacement is generated in each case.
If the diaphragms of the first diaphragm pump head are each freely oscillating metal diaphragms, a fluid may be transported at high temperatures because of the metal material. Because the first diaphragm pump head and the second diaphragm pump head are coupled to a control fluid via lines, these lines may act as cooling lines. Therefore, in a preferred embodiment, the diaphragms of the second diaphragm pump head may be made of a plastic, in particular PTFE, so that there is no danger that these plastic diaphragms will display significant flowing because of too high temperatures.
If the diaphragms of the second diaphragm pump head are each implemented as multilayered and are provided with a position controller and fracture signaling, the security during delivery of the fluid may be increased. Still greater security is achieved if a conductivity or viscosity sensor is provided inside the diaphragm control chambers of the first diaphragm pump head. If a metal diaphragm in the first diaphragm pump head breaks, the fluid to be delivered may reach the neighboring diaphragm control chambers, so that mixing of delivery fluid and control fluid would occur. Mixing of this type may change the electrical conductivity or the viscosity of the mixture in comparison to the values of the control fluid, so that a fracture of a metal membrane may be detected using the sensor.
The hydraulic coupling between the first diaphragm pump head and the second diaphragm pump head may occur using control fluids, which have water or oil. For example, special heat transfer oil may be used as the oil, if the pump device is used for delivering a fluid at high temperatures.
DESCRIPTION OF THE DRAWINGS
In the following, the present invention is described further on the basis of an exemplary embodiment illustrated in the drawing.
FIG. 1 shows a schematic illustration of an embodiment of the pump device according to the present invention.
DETAILED DESCRIPTION
FIG. 1 illustrates a pump device 1 having a first diaphragm pump head 2 and a second diaphragm pump head 8 . The first diaphragm pump head 2 has a first diaphragm 3 , which separates a first fluid delivery chamber 4 from a first diaphragm control chamber 5 . A fluid to be delivered by the first fluid delivery chamber 4 is fed by a supply line 60 , in which a fluid pressure p 1 exists (see arrow 7 ), to an inlet opening 6 having an intake valve 61 . When the first diaphragm 3 bulges out, the fluid may be transported by the first fluid delivery chamber 4 to a pressure valve 62 at one end of the fluid delivery chamber 4 . The membrane 3 bulges out due to the application of a pressure in the first diaphragm control chamber 5 . If a pressure which is higher by dp is applied there, a pressure p 1 +dp exists at the pressure valve 62 , using which the fluid is transported to the drain line 63 .
The pressure p 1 +dp is provided through a first line 13 by a second diaphragm pump head 8 . This has a second diaphragm 9 , which separates a second fluid delivery chamber 10 from a second diaphragm control chamber 11 . The second fluid delivery chamber 10 is coupled to the first diaphragm control chamber 5 by a first control fluid 12 . When the second diaphragm 9 bulges out, this first control fluid 12 is conducted through the first line 13 to the first diaphragm control chamber 5 , so that the first diaphragm 3 bulges out. A displacement of the first control fluid 12 of this type is achieved using a piston 15 , which exerts a stroke, which is directed downward in the embodiment shown in FIG. 1 . A second control fluid 14 provided in the second diaphragm control chamber 11 is used as the transmission medium of the volume change in an associated lower piston chamber 32 . The second diaphragm control chamber 11 extends up to a disk piston 31 of the piston 15 , so that the lower piston chamber 32 is a part of the second diaphragm control chamber 11 .
The stroke movement of the disk piston 31 in a direction which points downward in the embodiment shown in FIG. 1 is caused by a pump drive assembly 51 using a first piston rod 33 . A second piston rod 35 is situated diametrically opposite to the first piston rod 33 on the disk piston 31 . Therefore, the disk piston 31 is constructed symmetrically, so that the same area is provided on both diametrically opposite front faces of the disk piston 31 . This has the result that during a piston stroke into the lower piston chamber 32 , the same absolute value of a pressure and volume change is achieved as during a piston stroke up into a diametrically opposite upper piston chamber 34 .
The upper piston chamber 34 is part of a third diaphragm control chamber 17 , which is separated from a third fluid delivery chamber 19 by a third diaphragm 18 . During a downwardly directed stroke movement of the disk piston 31 , the volume of the upper piston chamber 34 enlarges, so that the third diaphragm 18 is contracted or compressed. A third control fluid 16 in the third diaphragm control chamber 17 is used as the transmission medium.
A transport of a fluid conducted at a pressure p 1 into the first fluid delivery chamber 4 is achieved if a pressure p 1 +dp is transmitted into the first diaphragm control chamber 5 via the line 13 . Therefore, this pressure p 1 +dp must also exist in the second fluid delivery chamber 10 . This is only possible if such a pressure is built up in the second diaphragm control chamber 11 . In achievements of the object according to the prior art, it is typical for a drive assembly to exert this entire pressure p 1 +dp on one or two single-acting plunger pistons. In contrast, in the embodiment according to the present invention, this is no longer necessary. For this purpose, as is obvious from FIG. 1 , the pressure p 1 is alternately transmitted via the diaphragms 3 and 24 , the control fluids 12 and 21 , the diaphragms 9 and 18 , and the control fluids 14 and 16 to the particular piston chamber 32 or 34 executing the intake stroke. If the unavoidable leakage of the control fluids 14 and 16 is compensated for by the refilling valves 38 and 40 , which are actuated by the diaphragm position controller, a brief pressure reduction down to atmospheric pressure, which is required in principle, occurs in the particular diaphragm control chamber. In the pump device according to the present invention, a pressure p 2 is then superimposed on the pressure existing in the diaphragm control chambers 11 and 17 , so that the pressure reduction may be compensated for.
If the piston of the second diaphragm pump head is implemented as a double-acting piston and the pressure p 2 is approximately equal to p 1 , only enough force has to be exerted on the piston rod 33 using the pump drive assembly 51 so that the piston 15 generates a differential pressure dp. For example, if p 1 =250 bar, a transport of the fluid through the first fluid delivery chamber 4 may be achieved using a differential pressure of dp=20 bar. The pump drive assembly 51 therefore no longer has to be designed for p 1 +dp=270 bar, but rather only for 20 bar. This allows fluid transport which is significantly more favorable economically.
The pressure p 2 is provided by a pump 50 via a feed line 36 to the containers 37 and 39 . In the case of the refilling procedure controlled by the diaphragm position, the pressure p 2 is relayed into the diaphragm control chambers 11 and 17 . Excess control fluid is drained via a ventilation valve 42 or 44 into a container 41 or 43 , respectively, and conducted using a return line 53 into a control fluid reservoir 52 .
During a downwardly directed stroke of the disk piston 31 , the upper piston chamber 34 is enlarged, so that the third membrane 18 is compressed. Therefore, the volume of the third fluid delivery chamber 19 also increases, which is coupled via a fourth control fluid 21 and the second line 22 to a fourth diaphragm control chamber 23 . The fourth diaphragm control chamber 23 is located in the first diaphragm control head 2 in the embodiment shown in FIG. 1 and is separated using a fourth diaphragm 24 from a fourth fluid delivery chamber 25 . This construction is mirror symmetric to the construction having first diaphragm 3 , first fluid delivery chamber 4 , and first diaphragm control chamber 5 . Upon an enlargement of the third fluid delivery chamber 19 , the volume of the fourth fluid delivery chamber 25 is also enlarged, so that suction and/or a fluid feed occurs via the image opening 26 having the intake valve 64 . If the disk piston is moved in a downwardly directed stroke, the conditions described above are reversed. The fourth fluid delivery chamber 25 delivers a fluid through an outlet opening 28 using a ventilation valve 65 into a drain line 63 , while the first fluid delivery chamber 4 is filled.
The first diaphragm 3 and fourth diaphragm 24 are freely oscillating metal diaphragms. A multilayered embodiment and a diaphragm position controller may be dispensed with. A check as to whether a fracture of a metal diaphragm has occurred may be performed indirectly by a conductivity or viscosity sensor 29 or 30 . In the event of a fracture of the diaphragm 3 , for example, mixing of the fluids occurs in the first fluid delivery chamber 4 and first diaphragm control chamber 5 , so that the electrical conductivity or the viscosity changes, which may be detected by the sensors 29 or 30 .
For example, in the pump device in the second diaphragm pump head 8 , if the third membrane 18 is compressed during an intake stroke of the disk piston 31 in such a way that it reaches its rear position, as noted above, the pressure in the third diaphragm control chamber 17 may drop to and/or below atmospheric pressure. This is undesirable because in this case a significant shear force increase of the piston 15 occurs suddenly and the pump drive assembly is strongly loaded. This may be avoided in the pump device according to the present invention by the permanent pressure impingement using p 2 , which approximately corresponds to p 1 , via the containers 37 and 39 .
In a further advantageous embodiment (not shown in FIG. 1 ) the second diaphragm pump head 8 has a separate diaphragm position controller in each case for the second diaphragm 9 and the third diaphragm 18 , as disclosed in EP 0 085 725 A1. The particular refilling valves 38 and 40 are replaced by a spring-loaded control plunger, which has an area having a conical face turned into its peripheral face, and a retention rod operationally linked thereto, which in turn releases or blocks a spring-loaded refilling valve. A spring-loaded support plate, which is operationally linked to the control plunger, and which is secured against falling out in the direction of the particular diaphragm 18 or 9 and is provided with through openings for the particular control fluid 16 or 14 , is situated in the area of the diaphragm control chamber 17 or 11 , respectively. If a loss of the control fluid 16 or 14 has occurred, the final position of the diaphragm 18 or 9 directed in the direction toward the diaphragm control chamber 17 or 11 is displaced, so that the support plate is moved against the spring force which supports it and against the spring for supporting the plunger. The movement of the control plate thus moves the control plunger, so that its conical peripheral area releases the retention rod, this rod falling in the direction of the control plunger longitudinal axis because of gravity, for example. Alternatively, for example, a spring may also force the retention rod in the direction of the control plunger. As a result, the refilling valve is released by the retention rod, so that because of the partial vacuum existing in the particular diaphragm control chamber 17 or 11 , the refilling valve is opened against the spring force which supports it and the control fluid 16 or 14 may flow into the diaphragm control chamber 17 or 11 , respectively. As soon as the normal control pressure has built up again in the diaphragm control chamber 17 or 11 , the previously displaced final position of the affected diaphragm 18 or 19 moves back into the correct final position and thus releases the support plate again, which releases the control plunger and thus displaces the retention rod back into the blocking position, by which the valve is blocked, which is also closed again by the pressure equalization because of its supporting spring.
In addition, it is also possible in another embodiment of the present invention to situate the double-acting piston 15 outside the second diaphragm pump head 8 . The piston 15 is situated with the disk piston 31 and the piston rods 33 and 35 in a control-fluid-tight housing separate from the diaphragm pump head 8 , which comprises the piston chambers 32 and 34 accommodating the piston 15 as well as flexible or installed lines for the control fluids 16 and 14 . These lines connect the particular piston chambers 32 and 34 to the diaphragm control chambers 16 and 11 .
There has thus been outlined, rather broadly, certain embodiments of the invention in order that the detailed description thereof herein may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional embodiments of the invention that will be described below and which will form the subject matter of the claims appended hereto.
In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of embodiments in addition to those described and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein, as well as the abstract, are for the purpose of description and should not be regarded as limiting.
As such, those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention. | The present invention relates to a pump device with a first diaphragm pump head having two or an integral multiple of two fluid delivery chambers and diaphragms associated therewith, which are hydraulically coupled to a second diaphragm pump head. The second diaphragm pump head has two additional fluid delivery chambers and additional membranes associated therewith, which are drivable by a double-acting piston via associated diaphragm control chambers, a refilling valve being connected in each case to the diaphragm control chambers and the diaphragm control chambers being temporarily impinged with a diaphragm control pressure, which is greater than atmospheric pressure, using the refilling valve. The piston may thus be activated using a relatively small force to achieve a delivery action. | 5 |
RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Application No. 61/275,090, filed on Aug. 24, 2009.
The entire teachings of the above application(s) are incorporated herein by reference.
FIELD OF THE INVENTION
This invention relates to supramolecular functional materials, particularly to coordination networks, more particularly to coordination polymers, and more particularly to metal based one-dimensional coordination polymers.
BACKGROUND OF THE INVENTION
Supramolecular chemistry is a relatively young branch of chemistry having undergone much of its development in the latter half of the 20th century [1]. The reason for this is twofold, firstly a thorough understanding of synthetic methods resulting in supramolecular systems was needed and secondly, powerful analytical technology used in structure elucidation and in physico-chemical property determination needed to be developed [1]. Analytical techniques that have been successfully employed in this regard include UV-visible, florescence-, and infra-red spectroscopy, nuclear magnetic resonance, powder X-ray diffraction and most importantly single-crystal X-ray diffraction [1]. Subsequently, the interest in supramolecular chemistry and the understanding of and rational design of property specific materials has increased over the last fifty years making supramolecular chemistry one of the fastest growing and most interdisciplinary areas in chemistry [1, 2, 3]. The quest to be able to manipulate and predict the nature of intermolecular forces in the design of property specific supramolecular entities remains one of the greatest scientific challenges of our day [1, 4, 5, 6].
One of the most studied areas at the moment is the formation of novel metal-organic frameworks (MOF's) and coordination polymers due to the possibility of using metal ions to align molecules in a desired direction [3, 7, 8]. One-dimensional (1D) coordination polymers have been extensively researched and subject to many review articles. It has been envisaged that these supramolecular materials could be used as molecular ferromagnets, metallic and superconducting polymers, non-linear optical materials and ferroelectric materials [9]. In more recent times the research focus has been aimed at magnetism and in particular room-temperature and near-room temperature molecular magnets [10-12]. The close packing of metal ions in a one-dimensional coordination polymer is favoured for the formation of functional materials characterized by displaying at least one physico-chemical property known to the group comprising: molecular ferromagnets, metallic and superconducting polymers, non-linear optical materials, ferroelectric materials and molecular magnets.
One of the chief problems encountered in this area of research is finding reliable methods for producing materials with interesting and possibly useful properties. Additionally, new materials showing promising physico-chemical properties are often extremely difficult to characterize and the exact formula and/or crystal structure of many of these materials remains unknown. Methods of ensuring successful single-crystal formation suitable for single-crystal X-ray diffraction need to be developed.
REFERENCES
1. Marais, C. G. (2008). The thermodynamics and kinetics of sorption . M. Sc thesis. University of Stellenbosch, South Africa.
2. Lehn, J-M. (1993). Science, 260, 1762.
3. Kitagawa, S., Kitaura, R., & Noro, S-I. (2004). Angew. Chem. Int. Ed., 43, 2334.
4. Ball, P. (1996). Nature, 381, 648.
5. Maddox, J. (1988). Nature, 335.
6. Gavezzotii, A. (1994). Acc. Chem. Res., 27, 309.
7. Ferey, G. (2008). Chem. Soc. Rev., 37, 191.
8. Janiak, C. (2003). Dalton Trans., 2781.
9. Chen, C-T., Suslick, K. S., (1993). Coord. Chem. Rev., 128, 293.
10. Jain, R., Kabir, K., Gilroy, J. B., Mitchell, K. A. R., Wong, K-C., Hicks, R. G. (2007). Nature, 445, 291.
11. Harvey, M. D., Crawford, T. D., Yee, G. T. (2008). Inorg. Chem., 47, 5649.
12. Miller, J. S. (2008) In Engineering of Crystalline Materials Properties (ed J. J. Novoa, D. Braga and L. Addadi), Springer Science & Business Media B. V., Dordrecht, The Netherlands, pp. 291-306.
The relevant teachings of the above references are incorporated herein by reference.
OBJECT OF INVENTION
It is an object of this invention to provide novel supramolecular functional materials comprising metal-based one-dimensional coordination polymers and at least one reliable method for their formation to at least alleviate the current disadvantage found in the current state of the art.
SUMMARY OF THE INVENTION
In accordance with this invention there is provided at least one supramolecular functional material comprising at least one, one-dimensional, metal-based coordination network.
There is further provided for the, or each, metal-based coordination network to be a metal-based one-dimensional coordination polymer, preferably comprising at least one organic ligand and at least one metal ion.
There is also provided for the metal-based coordination polymer to include at least one solvent molecule.
There is also provided for the metal ion and the organic ligand to form a chain structure when coordinated to one another to form the metal-based one-dimensional coordination polymer.
There is also provided for the metal ion, the organic ligand and the solvent molecule to form a chain structure and, thus form the metal-based one-dimensional coordination polymer.
There is also provided for the organic ligand to act, in use, as a bridging group between the metal ion forming the chain structure, for the organic ligand to be a carboxylate ligand.
There is also provided for the metal ion to be a transition group element, preferably selected from the group consisting of: titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc and cadmium.
There also provided for the metal-based coordination polymer to exhibit, in use, magnetic, electronic and/or optical physico-chemical properties.
The invention extends to a method of producing at least one supramolecular functional material comprising at least one metal-based coordination network, preferably a one-dimensional metal-based coordination network, alternatively a two-dimensional metal-based coordination network, further alternatively a three dimensional metal-based coordination network.
There is also provided for the method of producing the, or each, metal-based coordination network to be a metal-based one-dimensional coordination polymer, preferably comprising at least one organic ligand and at least one metal ion.
There is also provided for the method to include, in use, at least one solvent molecule.
There is also provided for the method wherein the metal ion and the organic ligand forms a chain structure when coordinated to one another forming the metal-based one-dimensional coordination polymer.
There is also provided for the method wherein the metal ion, the organic ligand and the solvent molecule forms a chain structure and, thus forming the metal-based one-dimensional coordination polymer, alternatively a two-dimensional coordination polymer, further alternatively a three-dimensional coordination polymer.
There is also provided for the method wherein the organic ligand acts, in use, as a bridging group between the metal ions forming the chain structure, for the organic ligand to be a carboxylate ligand.
There is also provided for the method wherein the metal ion is a transition group element, preferably selected from the group consisting of: titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc and cadmium.
There also provided the method wherein the metal-based coordination polymer to exhibit, in use, magnetic, electronic and/or optical physico-chemical properties.
There also provided the method wherein at least one reaction condition is selectable from a group consisting of: volume of reaction vessel, material composition of reaction vessel, temperature, pressure, humidity and gas defining an atmosphere inside reaction vessel.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing will be apparent from the following more particular description of example 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 embodiments of the present invention.
FIG. 1 a - 1 d shows diagrams and schemes relating to structure I;
FIG. 1 a shows the ligand-metal-ligand repeat unit forming the metal-based one-dimensional coordination polymer of the chemical formula [Zn(C 10 H 9 O 3 ) 2 ] n ;
FIG. 1 b shows the coordination environment as a sequence of tetrahedra forming the metal-based one-dimensional coordination polymer of the chemical formula [Zn(C 10 H 9 O 3 ) 2 ] n ;
FIG. 1 c a ball and stick representation of the crystal structure of the metal-based one-dimensional coordination polymer of the chemical formula [Zn(C 10 H 9 O 3 ) 2 ] n highlighting the coordination bonds between the ligand and metal ion;
FIG. 1 d a packing diagram of the crystal structure of [Zn(C 10 H 9 O 3 ) 2 ] n as viewed down the crystallographic c-axis;
FIG. 2 a - 2 d shows diagrams and schemes relating to structure II;
FIG. 2 a shows the ligand-metal-ligand repeat unit fanning the metal-based one-dimensional coordination polymer of the chemical formula [Co(C 10 H 9 O 3 ) 2 ] n ;
FIG. 2 b shows the coordination environment as a sequence of polyhedra forming the metal-based one-dimensional coordination polymer of the chemical formula [Co(C 10 H 9 O 3 ) 2 ] n ;
FIG. 2 c a ball and stick representation of the crystal structure of the metal-based one-dimensional coordination polymer of the chemical formula [Co(C 10 H 9 O 3 ) 2 ] n highlighting the coordination bonds between the ligand and metal ion;
FIG. 2 d a packing diagram of the crystal structure of [Co(C 10 H 9 O 3 ) 2 ] n as viewed down the crystallographic b-axis;
FIG. 3 a - 3 d shows diagrams and schemes relating to structure III;
FIG. 3 a shows the ligand-metal-ligand repeat unit forming the metal-based one-dimensional coordination polymer of the chemical formula [Co(C 8 H 7 O 2 ) 2 ] n ;
FIG. 3 b shows the coordination environment as a sequence of polyhedra forming the metal-based one-dimensional coordination polymer of the chemical formula [Co(C 8 H 7 O 2 ) 2 ] n ;
FIG. 3 c a ball and stick representation of the crystal structure of the metal-based one-dimensional coordination polymer of the chemical formula [Co(C 8 H 7 O 2 ) 2 ] n highlighting the coordination bonds between the ligand and metal ion;
FIG. 3 d a packing diagram of the crystal structure of [Co(C 8 H 7 O 2 ) 2 ] n as viewed down the crystallographic c-axis;
FIG. 4 a - 4 d shows diagrams and schemes relating to structure IV;
FIG. 4 a shows the ligand-metal-ligand repeat unit forming the metal-based one-dimensional coordination polymer of the chemical formula [Co(C 11 H 7 O 2 ) 2 (C 3 H 7 O)] n ;
FIG. 4 b shows the coordination environment as a sequence of polyhedra forming the metal-based one-dimensional coordination polymer of the chemical formula [Co (C 11 H 7 O 2 ) 2 (C 3 H 7 O)] n ;
FIG. 4 c a ball and stick representation of the crystal structure of the metal-based one-dimensional coordination polymer of the chemical formula [Co(C 11 H 7 O 2 ) 2 (C 3 H 7 O)] n highlighting the coordination bonds between the ligand and metal ion;
FIG. 4 d a packing diagram of the crystal structure of [Co(C 11 H 7 O 2 ) 2 (C 3 H 7 O)] n as viewed down the crystallographic a-axis;
FIG. 5 a - 5 d shows diagrams and schemes relating to structure V;
FIG. 5 a shows the ligand-metal-ligand repeat unit forming the metal-based one-dimensional coordination polymer of the chemical formula [Co(C 15 H 9 O 2 ) 4 (C 3 H 7 O) 2 ] n ;
FIG. 5 b shows the coordination environment as a sequence of polyhedra forming the metal-based one-dimensional coordination polymer of the chemical formula [Co(C 15 H 9 O 2 ) 4 (C 3 H 7 O) 2 ] n ;
FIG. 5 c a ball and stick representation of the crystal structure of the metal-based one-dimensional coordination polymer of the chemical formula [Co(C 15 H 9 O 2 ) 4 (C 3 H 7 O) 2 ] n highlighting the coordination bonds between the ligand and metal ion;
FIG. 5 d a packing diagram of the crystal structure of [Co(C 15 H 9 O 2 ) 4 (C 3 H 7 O) 2 ] n as viewed down the crystallographic b-axis;
FIG. 6 shows the coordination environment of structure III partly in a space-filling representation and partly in a ball and stick representation, and;
FIG. 7 shows the crystallographic data for structures I to V.
DETAILED DESCRIPTION OF THE INVENTION
A description of example embodiments of the invention follows.
The teachings of all patents, published applications and references cited herein are incorporated by reference in their entirety.
While this invention has been particularly shown and described with references to example embodiments thereof, it will be understood by those skilled in the art that various changes in faun and details may be made therein without departing from the scope of the invention encompassed by the appended claims.
Referring to the drawings, ( 1 a ) to ( 1 d ) shows structure I of chemical formula [Zn(C 10 H 9 O 3 )2]) n . FIG. ( 1 a ) shows the ligand-metal-ligand repeat unit [L 1 -M-L 2 ] n forming a metal-based one-dimensional coordination polymer of the chemical formula [Zn(C 10 H 9 O 3 ) 2 ] n where n is any integer 1 to infinity, the metal is Zn 2+ and the ligand (L 1 and L 2 ) is o-methoxy-cinnamate. Coordination bonds formed between oxygen atoms of the carboxylate group comprising the ligand (o-methoxy-cinnamate) and the metal (zinc) ion are indicated by broken lines. The coordination environment of the metal-based one-dimensional coordination polymer of the chemical formula [Zn(C 10 H 9 O 3 ) 2 ] n is shown in ( 1 b ) as a sequence of polyhedra wherein the polyhedra are all tetrahedral. FIG. ( 1 c ) shows a ball and stick representation of the crystal structure of the metal-based one-dimensional coordination polymer of the chemical formula [Zn(C 10 H 9 O 3 ) 2 ] n highlighting the coordination bonds between the ligand and metal ion. The distance between zinc ions (Zn—Zn) comprising the metal-based one-dimensional coordination polymer was measured as 3.469 Å. FIG. 1 d ) shows a packing diagram of the crystal structure of [Zn(C 10 H 9 O 3 ) 2 ] as viewed down the crystallographic c-axis. This is considered to be a very unusual structure as the ligands (o-methoxy-cinnamate) are arranged around the Zn 2+ in a propeller like 3 1 screw axis arrangement resulting in a chiral structure crystallised in the chiral space group P3 1 . There is provided that metal-based one-dimensional coordination polymer of the chemical formula [Zn(C 10 H 9 O 3 ) 2 ] n where n is any integer 1 to infinity, the metal is Zn 2+ and the ligand is o-methoxy-cinnamate may crystallize in other space groups and comprise polymorphs of the P3 1 structure. Crystallisation of [Zn(C 10 H 9 O 3 ) 2 ] was achieved by heating a solution containing zinc metal and o-methoxy-cinnamatic acid at about 80° C. for about one week.
FIGS. ( 2 a ) to ( 2 d ) shows structure II of chemical formula [Co(C 10 H 9 O 3 ) 2 ] n . FIG. 2 a shows the ligand-metal-ligand repeat unit forming the metal-based one-dimensional coordination polymer of the chemical formula [Co(C 10 H 9 O 3 ) 2 ] n where n is any integer 1 to infinity, the metal is Co 2+ and the ligand is o-methoxy-cinnamate. Coordination bonds formed between oxygen atoms of the carboxylate group comprising the ligand (o-methoxy-cinnamate) and the metal (cobalt) ion are indicated by broken lines. The coordination environment of the metal-based one-dimensional coordination polymer of the chemical formula [Co(C 10 H 9 O 3 ) 2 ] n is shown in ( 2 b ) as a sequence of polyhedral wherein the polyhedra are an alternating sequence of corner sharing tetrahedra and octahedra. FIG. 2 c ) shows a ball and stick representation of the crystal structure of the metal-based one-dimensional coordination polymer of the chemical formula [Co(C 10 H 9 O 3 ) 2 ] highlighting the coordination bonds between the ligand and metal ion.
The distance between cobalt ions (Co—Co) comprising the metal-based one-dimensional coordination polymer was measured as 3.169 Å and 3.199 Å. One of the interesting features of this crystal structure is that the arrangement of molecules around the cobalt ions causes the cobalt ions to be extremely close to one another along the chain comprising the metal-based one-dimensional coordination polymer. It is this distance which facilitates magnetic, electronic and/or optical physico-chemical properties or any combination of said physico-chemical properties characteristic of the metal-based one-dimensional coordination polymer of the chemical formula [Co(C 10 H 9 O 3 ) 2 ]. FIG. 2 d ) shows a packing diagram of the crystal structure of [Co(C 10 H 9 O 3 ) 2 ] as viewed down the crystallographic b-axis. The crystal structure crystallises in the monoclinic, centrosymmetric space group P2 1 /c. There is provided that metal-based one-dimensional coordination polymer of the chemical formula [Co(C 10 H 9 O 3 ) 2 ] where n is any integer 1 to infinity, the metal is Co 2+ and the ligand is o-methoxy-cinnamate may crystallise in other space groups and comprise polymorphs of the P2 1 /c structure.
FIGS. ( 3 a ) to ( 3 d ) shows structure III of chemical formula [Co(C 8 H 7 O 2 ) 2 ] n . FIG. 3 a ) shows the ligand-metal-ligand repeat unit forming the metal-based one-dimensional coordination polymer of the chemical formula [Co(C 8 H 7 O 2 ) 2 ] n where n is any integer 1 to infinity, the metal is Co 2+ and the ligand is p-toluate. Coordination bonds formed between oxygen atoms of the carboxylate group comprising the ligand (p-toluate) and the metal (cobalt) ion are indicated by broken lines. The coordination environment of the metal-based one-dimensional coordination polymer of the chemical formula [Co(C 8 H 7 O 2 ) 2 ] n is shown in ( 3 b ) as a sequence of polyhedra wherein the polyhedra are an alternating sequence of corner sharing tetrahedra and octahedra. FIG. 3 c ) shows a ball and stick representation of the crystal structure of the metal-based one-dimensional coordination polymer of the chemical formula [Co(C 8 H 7 O 2 ) 2 ] n highlighting the coordination bonds between the ligand and metal ion. The distance between cobalt ions (Co—Co) comprising the metal-based one-dimensional coordination polymer was measured as 3.143 Å. One of the interesting features of this crystal structure is that the arrangement of molecules around the cobalt ions causes the cobalt ions to be extremely close to one another along the chain comprising the metal-based one-dimensional coordination polymer. It is this distance which facilitates magnetic, electronic and/or optical physico-chemical properties or any combination of said physico-chemical properties characteristic of the metal-based one-dimensional coordination polymer of the chemical formula [Co(C 8 H 7 O 2 ) 2 ] n . FIG. ( 3 d ) shows a packing diagram of the crystal structure of [Co(C 8 H 7 O 2 ) 2 ] n as viewed down the crystallographic c-axis. The crystal structure crystallises in the orthorhombic, centrosymmetric space group Pbcn. There is provided that metal-based one-dimensional coordination polymer of the chemical formula [Co(C 8 H 7 O 2 ) 2 ] n where n is any integer 1 to infinity, the metal is Co 2+ and the ligand is p-toluate may crystallise in other space groups and comprise polymorphs of the Pbcn structure.
FIGS. ( 4 a ) to ( 4 d ) shows structure IV of chemical formula [Co(C 11 H 7 O 2 ) 2 (C 3 H 7 O)] n . FIG. ( 4 a ) shows the ligand-metal-ligand repeat unit forming the metal-based one-dimensional coordination polymer of the chemical formula [Co(C 11 H 7 O 2 ) 2 (C 3 H 7 O)] n where n is any integer 1 to infinity, the metal is Co 2+ and the ligand is naphthalene-1-carboxylic acid. Coordination bonds formed between oxygen atoms of the carboxylate group comprising the ligand (naphthalene-1-carboxylic acid) and the metal (cobalt) ion are indicated by broken lines. The coordination environment of the metal-based one-dimensional coordination polymer of the chemical formula [Co(C 11 H 7 O 2 ) 2 (C 3 H 7 O)] n , where n is shown in ( 4 b ) as a sequence of polyhedra wherein the polyhedra are an alternating sequence of corner sharing tetrahedra and octahedra. FIG. 4 c ) shows a ball and stick representation of the crystal structure of the metal-based one-dimensional coordination polymer of the chemical formula [Co(C 11 H 7 O 2 ) 2 (C 3 H 7 O)] n highlighting the coordination bonds between the ligand and metal ion and between the isopropanol solvent and the metal ion. The distance between cobalt ions (Co—Co) comprising the metal-based one-dimensional coordination polymer was measured as 3.224 Å, 3.470 Å and 3.475 Å. FIG. 4 d ) shows a packing diagram of the crystal structure of [Co(C 11 H 7 O 2 ) 2 (C 3 H 7 O)] n as viewed down the crystallographic a-axis. The crystal structure crystallises in the orthorhombic, non-centrosymmetric space group Pna2 1 . There is provided that metal-based one-dimensional coordination polymer of the chemical formula [Co(C 11 H 7 O 2 ) 2 (C 3 H 7 O)] n where n is any integer 1 to infinity, the metal is Co 2+ and the ligand is naphthalene-1-carboxylic acid may crystallise in other space groups and comprise polymorphs of the structure Pna2 1 .
FIGS. ( 5 a ) to ( 5 d ) shows structure V of chemical formula [Co(C 15 H 9 O 2 ) 4 (C 3 H 7 O) 2 ] n . FIG. 5 a ) shows the ligand-metal-ligand repeat unit forming the metal-based one-dimensional coordination polymer of the chemical formula [Co(C 15 H 9 O 2 ) 4 (C 3 H 7 O) 2 ] n where n is any integer 1 to infinity, the metal is Co 2+ and the ligand is anthracene-2-carboxylic acid. Coordination bonds formed between oxygen atoms of the carboxylate group comprising the ligand (anthracene-2-carboxylic acid) and the metal (cobalt) ion are indicated by broken lines. The coordination environment of the metal-based one-dimensional coordination polymer of the chemical formula [Co(C 15 H 9 O 2 ) 4 (C 3 H 7 O) 2 ] n is shown in ( 5 b ) as a sequence of polyhedra wherein the polyhedra are an alternating sequence of edge sharing tetrahedra and octahedra. FIG. ( 5 c ) shows a ball and stick representation of the crystal structure of the metal-based one-dimensional coordination polymer of the chemical formula [Co(C 15 H 9 O 2 ) 4 (C 3 H 7 O) 2 ] n highlighting the coordination bonds between the ligand and metal ion and between the isopropanol solvent and the metal ion. The distance between cobalt ions (Co—Co) comprising the metal-based one-dimensional coordination polymer was measured as 3.482 Å and 5.169 Å. FIG. ( 5 d ) shows a packing diagram of the crystal structure of [Co(C 15 H 9 O 2 ) 4 (C 3 H 7 O) 2 ] n as viewed down the crystallographic b-axis. The crystal structure crystallises in the monoclinic, non-centrosymmetric space group P2 1 . There is provided that metal-based one-dimensional coordination polymer of the chemical formula [Co(C 15 H 9 O 2 ) 4 (C 3 H 7 O) 2 ] n . where n is any integer 1 to infinity, the metal is Co 2+ and the ligand is anthracene-2-carboxylic acid may crystallize in other space groups and comprise polymorphs of the structure P2 1 .
FIG. 6 shows the coordination environment of structure III partly in a space-filling representation and partly in a ball and stick representation to indicate that the Co 2+ ions at closer than the sum of their van der Waals radii facilitating magnetic, electronic and/or optical physico-chemical properties or any combination of said physico-chemical properties characteristic of the metal-based one-dimensional coordination polymer herein described.
FIG. 7 shows the crystallographic data for structures I to V.
EXAMPLES
Embodiments of the invention will be illustrated by the following non-limiting examples of their synthesis and crystallisation. Several metal-based one-dimensional coordination polymers comprising zinc and cobalt metal ions and various aromatic carboxylates as ligands, have been crystallised via selective chemical reactive/interactive conditions.
The at least one supramolecular material comprising metal-based coordination networks in the form of metal-based one-dimensional coordination polymers are generally made via the direct reaction of the ligands (L) with the metal (M). The usual method of crystallisation is via reaction of a ligand (L) with a metal salt (M + ).
A typical non-limiting example of the crystallisation method used to form the supramolecular material of structure V is given.
0.2 g of anthracene-9-carboxylic acid and 0.027 g of Co metal (previously washed using 2M hydrochloric acid) were inserted into a Teflon hydrothermal bomb reactor. To this was added 10 ml of isopropanol. The reactor was then partially immersed in an oil bath and heated at 130° C. for 48 hours, followed by slow cooling to room temperature over 2 hours. The reaction product was then collected by filtration resulting in fine purple needle-like crystals (0.058 g). A single crystal of this was then selected and a single-crystal X-ray diffraction data set collected and solved. This structure, structure V, is presented in FIGS. ( 5 a ) to ( 5 d ).
Manganese supramolecular functional materials, as well as the zinc supramolecular functional materials described herein, were obtained by synthetic methods similar to those described in the preceding paragraph.
Not all structures employed the use of the Teflon hydrothermal bomb. For example structure I was crystallised by heating a solution containing zinc metal and o-methoxy-cinnamic acid at 80° C. for a week. | The field of this invention relates to supramolecular functional materials, particularly to coordination networks, more particularly to coordination polymers, more particularly to metal based one-dimensional coordination polymers. The metal based one-dimensional coordination polymers comprises a repeat unit [L 1 -M-L 2 ] n where L 1 and L 2 are one of a plurality of carboxylate ligands and L 1 can be the same as L 2 , M is a metal, particularly a transition metal, and n is an integer from 1 to infinity. The metal based one-dimensional coordination polymers display one or more physico-chemical properties giving at least one functionality to the supramolecular material. Furthermore, a method of forming the metal based one-dimensional coordination polymers is provided by a chemical reaction between said organic ligand and said metal where said method comprises at least one selectable chemical reaction condition from the group comprising: volume of reaction vessel, material composition of reaction vessel, temperature, pressure, humidity and gas defining an atmosphere inside reaction vessel. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to needles and, more specifically, to a magnetized acupuncture needle that constantly and consistently attracts the movement of energy, effecting best results. With magnetism, the needle is always working after insertion. This difference in needle function can best be compared to siphoning water with a hose using the mouth to induce the siphon compared to using an electric motor. The motor is most effective, consistent and continuous in starting and maintaining the flow of water and at a consistent rate. In this case magnetism is used and the flow of electrons induced by magnetism. An unskilled practitioner will have enhanced results as the magnetized needle affects electromagnetic energy at the point, even if the practitioner has been unable to independently stimulate this reaction.
2. Description of the Prior Art
There are other medical devices designed for magnetic therapy. Typical of these is U.S. Pat. No. 4,161,943 issued to Nogier on Jul. 24, 1979.
Another patent was issued to Kief on Apr. 21, 1981 as U.S. Pat. No. 4,262,672. Yet another U.S. Pat. No. 4,508,119 was issued to Tukamoto on Apr. 2, 1985 and still yet another was issued on U.S. Pat. No. 6,113,620 to Chung as U.S. Pat. No. 6,113,620.
Another patent was issued to Kim on Aug. 13, 2002 as U.S. Pat. No. 6,432,036. Yet another U.S. Pat. No. 6,488,668 was issued to Prindle on Dec. 3, 2002. Another was issued to Xie on Aug. 31, 2004 as U.S. Pat. No. 6,783,504 and still yet another was issued on Jan. 23, 2007 to Lin-Hendel as U.S. Pat. No. 7,167,752.
Another patent was issued to Wang on Apr. 8, 1992 as China Patent No. CN1060036. Yet another International Patent Application No. WO 98/02128 was issued to Chung on Jan. 22, 1998. Another was issued to Choi on Feb. 25, 2004 as Korea Patent No. KR20040016928.
An apparatus for implanting magnetized or magnetizable needles, which apparatus comprises a tubular body, means to support a flat needle of small dimensions, made of a magnetizable metal, and means to drive the said needle into the tissues. A permanent magnet, taking the form of a substantially circular flat tablet is inserted in closed end of the body with one of its sides exposed outwardly of same. When the needle has been implanted, it may be magnetized or remagnetized as often as required by merely applying the exposed side of the tablet against the tail of the needle. In a modification the body of the apparatus is provided with a socket-like protecting cap and the tablet is inserted in the closed end of this cap, the needle supporting means being so arranged that the tip of the needle is situated close to the said closed end of the cap in order to be already magnetized by the tablet before the needle is implanted.
An acupuncture instrument for use in producing analgesia comprises a needle having a head and an electrical connection for applying a transformer arrangement including an electric coil constituting a secondary winding of the transformer arrangement and having two poles, one of the poles being insulated therefrom, the electric coil being arranged on the needle head and being capable of being surrounded by another coil constituting a primary winding of the transformer arrangement, and an annular electrode electrically connected to the other pole of the secondary winding and insulated with respect thereto and vertically movably arranged on the secondary winding.
A needle having at least one of magnetic field and electrostatic field improves effects of acupuncture in Oriental medical therapy. Further, a magnetized and/or electrostatically charged injection needle can be used for so-called “block therapy”.
A magnetic needle for acupuncture is disclosed. The magnetic needle of this invention has a housing having an opening and a magnet seated in the opening of the housing. A wedge-shaped projection is held in the opening of the housing so as to project into the exterior of the bottom wall of the housing and come into contact with the magnet. The projection forms an intensive magnetic field around a meridian point having fine electric current or electromagnetic waves. The projection thus magnetically stimulates the meridian point while performing a magnetic massage effect on the meridian point. The magnetic needle accomplishes an acupuncturing effect for relieving pain and curing disease as expected in typical acupuncture.
A device for magnetic focus radiating medical treatment is disclosed. The device has a support member holding both a magnet and a needle therein in a way such that the magnet comes into contact with the needle. The magnet is used for generating lines of magnetic force, while the needle is used for radiating the lines of magnetic force from the magnet onto a desired part of the human body. A hollow casing receives the support member therein with the tip of the needle being selectively projected from the lower end of the casing. This casing has an external thread at its lower end. An outside plug detachably covers the top end of the casing. A cap is movably tightened to the external thread of the casing. This cap also has a needle hole at a central portion of its wall so as to allow the needle to pass through the needle hole. In the above device, the exposed length of the needle outside the cap is adjustable as desired by appropriately tightening or loosening the internally threaded cap relative to the externally threaded casing.
A device for magnetic focus radiating medical treatment is disclosed. The device has a support member holding both a magnet and a needle therein in a way such that the magnet comes into contact with the needle. The magnet is used for generating lines of magnetic force, while the needle is used for radiating the lines of magnetic force from the magnet onto a desired part of the human body. A hollow casing receives the support member therein with the tip of the needle being selectively projected from the lower end of the casing. This casing has an external thread at its lower end. An outside plug detachably covers the top end of the casing. A cap is movably tightened to the external thread of the casing. This cap also has a needle hole at a central portion of its wall so as to allow the needle to pass through the needle hole. In the above device, the exposed length of the needle outside the cap is adjustable as desired by appropriately tightening or loosening the internally threaded cap relative to the externally threaded casing.
A method for effective weight loss without negative or harmful side effects as well as for the treatment of ailments in human patients. Treatment is achieved using a combination of acupuncture and magnets. The method includes the steps of placing several acupuncture needles into specified locations on the human body, removing the acupuncture needles, and placing several magnets onto the same locations that the needles previously occupied. Another important object of the present invention is to provide and effective method of coping with and managing diabetes.
An electronic acupressure aide and stimulating device implemented using a hand-held or palm-held electronic computing device or another computing device which may be a designated unit. The electronic acupressure aide and stimulating device allows a practitioner to apply a pulse sequence to a set of predetermined acu-points such as those related to acupressure, acupuncture, trigger points or Jin-Shin Jyutsu, to name a few. A displayed chart related to the acu-points identifies the health condition and the pulse sequence.
The present invention relates to a kind of miniature strong magnetism therapeutic device which is composed of a dia 24 mm multiply 27 mm Nd—Fe—B permanent magnet, a dia 24 mm bottom, dia 3 mm top and 10 mm height conoid which is punched a 2 mm straight hole on centre, and aluminum alloy casing and housing. The magnetic field intensity at top surface of said invention is 6000 Gauss. When it is used for massage or needle press on affected part or acupuncture point, the magnetic beam with penetrating feeling is radiated on human body to improve the blood circulation of local muscle or joint and to variate the excitation and inhibition of central nervous system, thus producing the analgesic action. If it is used for curing muscular spasm, lumbocrural pain, arthritis and neuralgia, it has quick analgesic and antispasm curative effects and no by-effects.
A magnetic needle for acupuncture is disclosed. The magnetic needle of this invention has a housing having an opening and a magnet seated in the opening of the housing. A wedge-shaped projection is held in the opening of the housing so as to project into the exterior of the bottom wall of the housing and come into contact with the magnet. The projection forms an intensive magnetic field around a meridian point having fine electric current or electromagnetic waves. The projection thus magnetically stimulates the meridian point while performing a magnetic massage effect on the meridian point. The magnetic needle accomplishes an acupuncturing effect for relieving pain and curing disease as expected in typical acupuncture.
PURPOSE: Provided are an acupuncture needle using bamboo, charcoal and a magnet having beneficial effects on the human body, and a manufacturing method thereof, to suppress pain by pressing acupuncture spots and to enhance a user's health and vitality by stimulating blood circulation and generating far-infrared radiation. CONSTITUTION: The acupuncture needle ( 6 ) comprises: a bamboo cylinder ( 2 ); an energy radiating plate ( 1 ) and a circular magnet ( 3 ) provided at a bamboo node ( 4 ); and a charcoal rod ( 5 ) filling the bamboo cylinder ( 2 ). The acupuncture needle is prepared by putting a circular magnet and a charcoal rod into the bamboo cylinder and sealing with the energy radiating plate.
While these processes may be suitable for the purposes for which they were designed, they would not be as suitable for the purposes of the present invention, as hereinafter described.
SUMMARY OF THE PRESENT INVENTION
Acupuncture is a medical treatment using needles inserted at specific locations to treat illness, pain and to enhance the flow of Qi in establishing health and well-being within a patient. Magnetism has been applied in this treatment through ancillary devices used to create a magnetic field within the needle. The present invention has combined the magnetic field and acupuncture needle therapy into a single device by permanently magnetizing the needles with either a north-south polarity or a south-north polarity thereby eliminating the need for ancillary devices to induce a magnetic field within the needle simplifying treatment.
The magnetic needles of the present invention may replace electro-stimulation of standard acupuncture needles as well as enhance the effects achieved by advances acupuncture practitioners for those patients having difficulty inducing the movement of the body's energy and the elderly whose body energy has weakened and does not circulate well.
Some of the advantages of using magnetized needles are as follows:
a) The effects that surface magnets provide is also achieved but more powerful due to the magnetized needle actually being inserted into the point and directly into the body's bioelectric/magnetic field rather than near the field on the surface; b) A much smaller magnetic force is required with insertion compared to the larger (often 3000 gauss or more) when used directly on the skin; c) Needles may be magnetized with poles N—S or S—N and the varied effect of the needle would be available at the discrimination of the practitioner; d) By inserting a N—S needle into a point and a S—N needle very nearby in the same point or pathway one may create additional magnetic stimulation to the bioenergetic circulation, literally forcing, rather than inducing, the bioelectric flow; and e) As acupuncture pathways are distinct and proscribed in medical literature one may select points up and down the meridians, or energetic pathways, and combine several magnetized needles but not only N—S, one may perhaps alternate N—S, S—N, and so on.
Other advantages of the magnetized needles can be applied to other afflictions including addictions and weight loss. Smaller needles are sometimes inserted into auricular (ear) points to stimulate the micro-acupuncture system found in each persons (or animals) ears. Some of these points are used for weight loss, some for addictions and most other conditions may be affected.
A primary object of the present invention is to provide a magnetized acupuncture needle.
Another object of the present invention is to provide an acupuncture needle having either a north-south polarity or a south-north polarity.
Additional objects of the present invention will appear as the description proceeds.
The present invention overcomes the shortcomings of the prior art by providing a magnetized acupuncture needle that constantly and consistently attracts the movement of energy, effecting best results. With magnetism, the needle is always working after insertion. This difference in needle function can best be compared to siphoning water with a hose using the mouth to induce the siphon compared to using an electric motor. The motor is most effective, consistent and continuous in starting and maintaining the flow of water and at a consistent rate. In this case magnetism is used and the flow of electrons induced by magnetism. An unskilled practitioner will have enhanced results as the magnetized needle affects electromagnetic energy at the point, even if the practitioner has been unable to independently stimulate this reaction.
The foregoing and other objects and advantages will appear from the description to follow. In the description reference is made to the accompanying drawings, which forms a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. These embodiments will be 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 structural changes may be made without departing from the scope of the invention. In the accompanying drawings, like reference characters designate the same or similar parts throughout the several views.
The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is best defined by the appended claims.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
In order that the invention may be more fully understood, it will now be described, by way of example, with reference to the accompanying drawing in which:
FIG. 1 is an illustrative view of prior art.
FIG. 2 is an illustrative view of the present invention.
FIG. 3 is an illustrative view of the magnetized acupuncture needle having a north to south polarity.
FIG. 4 is an illustrative view of the magnetized acupuncture needle having a south to north polarity.
FIG. 5 is an illustrative view of the application of the present invention.
FIG. 6 is a flow chart of the acupuncture therapy using magnetized needles.
FIG. 7 is a flow chart of the present invention.
FIG. 8 is another illustration of the present invention in use as a tack needle.
DESCRIPTION OF THE REFERENCED NUMERALS
Turning now descriptively to the drawings, in which similar reference characters denote similar elements throughout the several views, the figures illustrate the Magnetic Acupuncture Needle of the present invention. With regard to the reference numerals used, the following numbering is used throughout the various drawing figures.
10 Magnetic Acupuncture Needle of the present invention 12 electromagnetic charge of 10 14 patient's body 16 magnetic bio-field of energy of 14 18 acupuncture meridian target point 20 prior art 22 non-magnetic acupuncture needle of 20 24 head of 10 25 shaft of 10 26 point of 10 28 northern polarity of 12 30 southern polarity of 12 32 north to south needle 34 south to north needle 36 needle receptor 38 ear press tack needle
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The following discussion describes in detail one embodiment of the invention (and several variations of that embodiment). This discussion should not be construed, however, as limiting the invention to those particular embodiments, practitioners skilled in the art will recognize numerous other embodiments as well. For definition of the complete scope of the invention, the reader is directed to appended claims.
FIG. 1 is an illustrative view of prior art 20 . Acupuncture is an eastern medicine that relies upon fine sterile non-magnetic metal needles 22 inserted into specific points 18 on the body 14 . The theory is that there is a constant circulation of a magnetic bio-field of energy 16 in the body and that when the energy flow is obstructed by natural or traumatic means, a corresponding disease will eventually manifest. Keeping this flow of energy undisturbed is the goal of acupuncture. Some practitioners using non-magnetic needles 22 are more skilled at needle manipulation and the sensation at the needle. A non-magnetized acupuncture needle 22 is dependent upon the practitioners' skill to induce a result. The present invention over comes this by providing a magnetized acupuncture needle.
FIG. 2 is an illustrative view of the present invention 10 . The present invention is a magnetized acupuncture needle 10 having an electromagnetic charge 12 that constantly and consistently attracts the movement of the magnetic bio-field of energy 16 produced by the patient's body 14 , effecting best results. With magnetism, the needle 10 is always working after insertion. This difference in needle function can best be compared to siphoning water with a hose using the mouth to induce the siphon compared to using an electric motor. The motor is most effective, consistent and continuous in starting and maintaining the flow of water and at a consistent rate. In this case magnetism is used and the flow of electrons induced by magnetism. An unskilled practitioner will have enhanced results as the magnetized needle 10 effects electromagnetic energy at the insertion point 18 , even if the practitioner has been unable to independently stimulate this reaction. The needle 10 has a head 24 with a northern polarity 28 and a point 26 with a southern polarity 30 .
FIG. 3 is an illustrative view of the magnetized acupuncture needle 10 having a magnetic field charge 12 with a north 28 to south polarity 30 from the head 24 to the point 26 . A shaft 25 is disposed between the head 24 and the point 26 . Shown is the magnetized acupuncture needle 10 of the present invention that constantly and consistently attracts the movement of energy. With magnetism, the needle 10 is always working after insertion because the flow of electrons induced by magnetism are constant and induces the bio-field of energy to move or flow constantly through the body. The north to south polarity magnetic needle 32 could be used alone or in conjunction with a south to north polarity magnetic needle.
FIG. 4 is an illustrative view of the magnetized acupuncture needle 10 having a magnetic field charge 12 with a south 30 to north polarity 28 from the head 24 to the point 26 . The south to north polarity needle 34 could be used alone or in conjunction with a north to south polarity needle.
FIG. 5 is an illustrative view of the application of the present invention 10 . Shown is biological electromagnetic field 16 enhanced by the insertion of a permanent magnet. The magnetic acupuncture needle 10 is inserted into a predetermined acupuncture meridian-target insertion point 18 to induce the flow of a body's energy by using the electrical charge 12 of the magnetized needle 10 as a connective member to reestablish the bio-field of energy 16 to move or flow constantly through the patients body 14 . While depicted as a north to south magnetized needle 10 , the present invention provides for either north to south or south to north magnetized needles 10 that may be used in combination with each other.
FIG. 6 is a flow chart of the acupuncture therapy using magnetized needles 10 including the steps of selecting and examining the patient, making a diagnosis and determining the target insertion locations, and selecting and inserting the magnetized acupuncture needles 10 .
FIG. 7 is a flow chart of the present invention 10 . Shown is a flow chart of the method for enhancing the flow of electrons induced by magnetism including the steps of selecting the needles 10 , inserting the needles 10 into an administering device, placing the tip of the needle 10 over the target area, applying pressure to the head of the needle 10 to insert it therein and removing the administering device.
FIG. 8 is an illustrative view of the magnetized acupuncture needle 10 manufactured as an ear press tack needle 38 for an ear 36 having a magnetic field comprising either a north to south polarity 32 or a south to north polarity 34 needle.
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.
While certain novel features of this invention have been shown and described and are pointed out in the annexed claims, it is not intended to be limited to the details above, since it will be understood that various omissions, modifications, substitutions and changes in the forms and details of the device illustrated and in its operation can be made by those skilled in the art without departing in any way from the spirit of the present invention.
Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention. | A magnetic acupuncture needle combining the treatments of magnetic therapy and acupuncture by affecting the natural magnetic bio-field of energy of the patient's body and attracting it to the target point of treatment. | 0 |
FIELD
[0001] The present invention relates to a method of generating a 2-dimensional profile of the path taken by an object travelling over a 3-dimensional surface at a location. The invention has particular reference to a method for profiling the path taken by a ball such, for example, as a golf ball when moving over the surface, such as when a golf ball is putted on a green. The invention also embraces apparatus for generating such a 2-dimensional profile.
BACKGROUND
[0002] Golfers and golf watchers are generally interested in optimising their techniques. This interest is manifested in studying information related to the golf ball's trajectory information and velocity. In particular, the path that a ball takes on its way to the hole is a point of major interest for players and watchers alike. There is always a desire to improve one's golf game. This is particularly true of major competitions where the target holes are moved continually to provide the most challenging circumstances for approach shots. In these instances, the golfer's ability to “read” the profile of the ground and the contours and play accordingly are paramount. The skill of the golfer is in hitting the ball so that its travel makes use of the dips and bumps of the surface, guiding the ball to the hole.
SUMMARY
[0003] According to one aspect of the present invention, there is provided a method of generating a 2-dimensional profile of the path taken by an object travelling over a 3-dimensional surface at a location, said method comprising the steps of:
[0004] (i) obtaining a digitised map of said location, said map comprising contour information defining contours of said surface;
[0005] (ii) capturing a moving image of said object as it travels over the surface;
[0006] (iii) obtaining information allowing the captured image to be correlated with said map and thereafter performing such correlation;
[0007] (iv) using said correlation, processing said captured moving image to generate information defining the path taken by the object over said surface as defined by the map; and
[0008] (v) from said contour information determining the profile of said path.
[0009] By “map” it will be understood that what is meant is the data defining the contours of said surface; it is not necessary for the map to be represented in a graphical manner, although such graphical representation certainly also falls within the ambit of the present invention. In some instances it will be appreciated that the shape of the surface may change over time. For instance a putting green may be remodelled from time to time. In such case the invention comprehends generating a 2-dimensional profile of the path taken by an object travelling over a 3-dimensional surface at a location at a given point in time. In such case, the digitised map defines the contours of the surface at said point in time.
[0010] In some embodiments, said captured image may be processed to generate information for allowing the image to be correlated with the map. For example, said information for allowing the image to be correlated with the map may comprise information defining the surface. By “correlating” the image with the map is meant aligning the captured image with the obtained map, so that each point on the surface as captured in the moving image may be mapped to a corresponding respective point on the map, thereby to allow the path taken by the object to be plotted on the map.
[0011] Further, in some embodiments, positional information may be obtained that defines the position at which the moving image is captured. Such positional information may be used to acquire the digitised map of the location. Said positional information may comprise GPS data or comparable positional technology identifying the geographical location at which the moving image is captured.
[0012] Said captured moving image may comprise time information defining the relative or absolute time at which each moment or frame of the moving image is captured. In some embodiments, said captured moving image may comprise a frame rate of the kind known to those skilled in the art.
[0013] In some embodiments of the invention, information defining the change of position of the object on the surface over time may be obtained. Such information may be derived from said time information and said information defining the path taken by the object over the surface as defined by the map. Said information defining the change of position of the object may comprise the distance travelled by the object from a predetermined datum at any given instant in time. Said information may be processed, e.g., by differentiation, to obtain information defining the instantaneous velocity of the object.
[0014] Further, said information defining the instantaneous velocity of the object may be processed, e.g., by differentiation to obtain information defining the instantaneous acceleration (or ‘drive’) of the objection. Thus, in some embodiments, said information may comprise the acceleration of the object. This information may be calculated by obtaining positioning information of the object at equidistant time intervals.
[0015] In another aspect of the present invention therefore there is provided apparatus for generating a 2-dimensional profile of the path taken by an object travelling over a 3-dimensional surface at a location, said apparatus comprising:
[0016] (i) an image capturing device for capturing a moving image of said object as it travels over said surface;
[0017] (ii) a position recording device for recording the geographical position of the location at which said moving image is captured;
[0018] (iii) a data acquiring device for obtaining a digitised map of said location based on said geographical position, said map comprising contour information defining contours of said surface; and
[0019] (iv) information processing means for processing said captured moving image to generate image information for allowing the image to be correlated with said map, using said image information to correlate said captured moving image with said map, processing said captured moving image using said correlation to generate information defining the path taken by the object over said surface as defined by the map and determining the profile of said path from said contour information.
[0020] As mentioned above, where the shape of the surface alters with time, the digitised map of the location comprises contour information defining the contours of the surface at the relevant time.
[0021] In one embodiment, the moving image may be captured using a hand-held device incorporating a camera or other moving image recording device and a global navigation satellite system receiver such, for example, as a GPS device, or another geo-spatial positioning device, which is able to record the geographic position at which the moving image is captured by said handheld device.
[0022] Alternatively, the information for allowing the image to be correlated with the map may comprise information defining the position and orientation relative to the surface at which the moving image is captured. For example, where the image is captured using a stationary camera, or a plurality of such cameras, then the spatial position of such cameras relative to the surface may be recorded. Said spatial position may be defined by the latitudinal, longitudinal and altitudinal coordinates, and orientation, of said one or more cameras relative to the surface.
[0023] Thus, in yet another aspect of the invention there is provided apparatus for generating a 2-dimensional profile of the path taken by an object travelling over a 3-dimensional surface at a location, said apparatus comprising:
[0024] (i) an image capturing device for capturing a moving image of said object as it travels over said surface;
[0025] (ii) a data acquiring device for obtaining a digitised map of said location, said map comprising contour information defining contours of said surface, and information for allowing the captured image to be correlated with said map; and
[0026] (iii) information processing means for correlating said captured moving image with said map, processing said captured moving image using said correlation to generate information defining the path taken by the object over said surface as defined by the map and determining the profile of said path from said contour information.
[0027] Said information for allowing the captured image to be correlated with the map may therefore include the position and orientation of the image capturing device relative to said surface.
[0028] In some embodiments said information processing means may comprise a processor or at least one processor. However, by ‘information processing means’ is generally meant any suitable means for processing data electronically, and is not necessarily confined to the use of a single processor or machine or to a single location. For instance said information processing means may be provided as a service over the Internet (“Cloud Computing”) or any other computer network.
[0029] In some embodiments, the captured moving image may comprise recorded time information defining the absolute or relative time at which each moment or frame of the moving image is captured. Such recorded time information is well known to those skilled in the art. Based on such time information and the information defining the path taken by the object over the surface as defined by the map, said processor or other information processing means may be configured for generating information defining the change of position of the object with time.
[0030] In some embodiments, said processor or other information processing means may be configured to process such information to determine the instantaneous velocity and/or acceleration (‘drive’) of the object, e.g., by differentiating the information defining the path taken by the object over the surface (i.e., distance travelled) with respect to the time information.
[0031] Suitably, said surface may comprise a putting green, and said object may comprise a golf ball. It will be appreciated, however, that the present invention may be applied to any situation where it is desired to plot the 2-dimensional profile of an object, such as a ball, moving over a 3-dimensional surface, which 3-dimensional surface is preferably non-planar. For instance, the invention may also be applied to plotting the 2-dimensional profile of a bowling ball moving over a profiled ‘Crown Green’ bowling green.
[0032] Thus, where the movement of a golf or other ball over the surface, for example a green or other playing surface is captured using one or more stationary cameras, for example where a golf tournament is being televised, the position and orientation of the one or more cameras relative to the green may be used to correlate the image acquired by the one or more cameras with a digitised map of the green or other surface.
[0033] Alternatively, where movement of the ball over the surface is captured using a video camera of the kind that is incorporated into a hand-held device such, for example, as a mobile telephone having such video-camera functionality, the general geo-spatial position of the location may be determined using a GPS device or other global navigation satellite system receiver integrated in the handheld device, and the captured image processed to allow it to be correlated with a map obtained on the basis of said geo-spatial position.
[0034] In some implementations, the subject matter described herein provides the advantage of building knowledge of particular golf courses and greens; building knowledge and appreciation of the techniques and skills of leading players; and enabling an appreciation of particular approaches and green shots.
[0035] In yet another aspect of the present invention there is provided a computing system-implemented method of generating a 2-dimensional profile of a path over a 3-dimensional surface taken by an object at a location, said method comprising:
[0036] correlating digital map information of the location with moving image information captured of the object in a path over the 3-dimensional surface of the location to generate a correlation between the object and the surface, the digital map information including contour information defining a contour of the 3-dimensional surface;
[0037] generating path information of the path over the 3-dimensional surface taken by the object based on the correlation; and determining the 2-dimensional profile of the path over the 3-dimensional surface taken by the object based on the path information and the contour information.
[0038] Said computing system-implemented method may in some embodiments be implemented on a single computer. Alternatively the computing resources that constitute the computing system may be distributed over a network, e.g., the Internet. For example, in some embodiments, the method may be implemented using at least some computing services provided over the Internet as “Cloud Computing”.
[0039] In yet another aspect of the present invention there is provided a computer program product, embodied in instruction code stored on a machine-readable medium, for generating a 2-dimensional profile of a path over a 3-dimensional surface taken by an object at a location, the instruction code including instructions that cause a computing system to:
[0040] correlate digital map information of the location with moving image information captured of the object in a path over the surface of the location to generate a correlation between the object and the surface, the digital map information including contour information defining a contour of the 3-dimensional surface;
[0041] generate path information of the path over the 3-dimensional surface taken by the object based on the correlation; and
[0042] determine the 2-dimensional profile of the path over the 3-dimensional surface taken by the object based on the path information and the contour information.
[0043] In yet another aspect of the present invention there is provided a computing system for generating a 2-dimensional profile of a path over a 3-dimensional surface taken by an object at a location, the computing system comprising:
[0044] information processing means adapted to:
correlate digital map information of the location with moving image information captured of the object in a path over the surface of the location to generate a correlation between the object and the surface, the digital map information including contour information defining a contour of the 3-dimensional surface; generate path information of the path over the 3-dimensional surface taken by the object based on the correlation; and determine the 2-dimensional profile of the path over the 3-dimensional surface taken by the object based on the path information and the contour information; and
[0048] a display to generate and output a display of the 2-dimensional profile of the path over the 3-dimensional surface.
[0049] As mentioned above, said information processing technique means may comprise one or more computer processors.
[0050] In yet another aspect of the present invention there is provided a computer-system implemented method of generating a 2-dimensional profile of a path over a 3-dimensional surface taken by an object at a location, the method comprising:
[0051] receiving in a computing system digital map information of the location, the digital map information including contour information defining a contour of the 3-dimensional surface;
[0052] receiving in the computing system moving image information captured of the object in a path over the surface of the location;
[0053] correlating, using the computing system, the digital map information with the moving image information to generate a correlation between the object and the surface;
[0054] generating, using the computing system, path information of the path over the 3-dimensional surface taken by the object based on the correlation; and
[0055] determining, using the computing system, the 2-dimensional profile of the path over the 3-dimensional surface taken by the object based on the path information and the contour information.
[0056] In yet another aspect of the present invention there is provided a computer-system implemented method comprising:
[0057] correlating digital map information of the location received from a data-acquiring device with moving image information captured by an image-capturing device of the object in a path over the 3-dimensional surface of the location to generate a correlation between the object and the surface, the digital map information including contour information defining a contour of the 3-dimensional surface;
[0058] generating path information of the path over the 3-dimensional surface taken by the object based on the correlation; and
[0059] determining the 2-dimensional profile of the path over the 3-dimensional surface taken by the object based on the path information and the contour information.
[0060] The above description sets forth the more important features of the present invention in order that the detailed description thereof that follows may be understood, and in order that the present contributions to the art may be better appreciated. Other objects and features of the present invention will become apparent from the following detailed description considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are designed solely for the purposes of illustration and not as a definition of the limits of the invention, for which reference should be made to the appended claims.
[0061] The details of one or more variations of the subject matter described herein are set forth in the accompanying drawings and the description below. Other features and advantages of the subject matter described herein will be apparent from the description and drawings, and from the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0062] The accompanying drawings, which are incorporated in and constitute a part of this specification, show certain aspects of the subject matter disclosed herein and, together with the description, help explain some of the principles associated with the disclosed embodiments. In the drawings,
[0063] FIG. 1 depicts in schematic a method of generating a two-dimensional profile of the path taken by an object;
[0064] FIG. 2 depicts a block diagram of the present invention; and
[0065] FIG. 3 depicts graphically a possible correlation profile of a captured image of a three-dimensional surface of the present invention.
[0066] FIG. 4 depicts graphically a plan view of the path taken by an object over a surface.
[0067] FIG. 5 depicts a possible example of information displayed graphically in accordance with the invention.
[0068] Like reference symbols in the various drawings indicate like elements.
DETAILED DESCRIPTION
[0069] The implementations set forth in the following description do not represent all implementations consistent with the subject matter described herein. Instead, they are merely some examples consistent with certain aspects related to the described subject matter. It is also to be understood that the terminology used herein is for the purpose of describing particular implementations only, and is not intended to be limiting.
[0070] FIG. 1 depicts schematically a method of generating a two-dimensional profile of a path taken by an object 111 moving over a surface 120 such as, for example, a golf ball moving on a putting green. FIG. 1 also depicts a digitised map 180 of the surface 120 . The digitised map 180 comprises contour information defining contours of the surface 120 . FIG. 1 also depicts the object 111 as it travels over said surface 120 . Finally, FIG. 1 depicts information defined by the path taken by moving object 111 .
[0071] Although FIG. 1 depicts a digitised map 180 at surface 120 , said digitised map 180 may exist at other locations such as at a remote user location, at a computer server, at a database, and the like.
[0072] In some implementations, it is preferred that the capturing of a moving image be with a digital camera or a similar video-recording device. Furthermore, it is preferred that the capturing of a moving image over the surface be continuous. For example, capturing of this implementation may be with a digital camera worn by golfer 105 .
[0073] Advantageously, the camera or other video-recording device is capable of recording the absolute or relative time of capture of each frame or moment of the moving image. For instance, the captured moving image may comprise a time code of the kind well known to those skilled in the art. This allows the absolute or relative time that the object 111 is disposed at each position to be recorded.
[0074] The moving image may be captured by or one or more cameras 112 that are fixed relative to the surface 120 at least during capture of the moving image; the position(s) and orientation(s) of such one or more cameras 112 relative to the surface 120 may be recorded to facilitate correlation of the moving image with the digitised map 180 . Thus, the geo-spatial position(s) of the one or more cameras may be determined, for example using a GPS or another purposively similar global navigation satellite system receiver at the position(s) of or incorporated in the camera(s).
[0075] Alternatively, the capturing of the moving image can be obtained by a mobile telephone equipped with video recording capabilities. Thus, for example, a third party may record the moving image with their mobile telephone's video recording device.
[0076] In some implementations, the information for allowing the image to be correlated with the map may include surface data such as inclines and valleys of the surface. For example, a putting green normally has slight inclines such that the surface is not completely flat, representing a challenge to the golfer. Thus, in such implementations, the captured moving image may be processed to identify such characteristic features of the surface to enable the moving image of the surface to be correlated with the digitised map, e.g., by using a processor to align such characteristic features in the captured moving image with the same characteristic features of the surface as defined by the map. The correct map may be identified using GPS data captured by a receiver positioned at the surface.
[0077] Alternatively, in some implementations, the information for allowing the image to be correlated with the map may include information defining the position and orientation of the moving object relative to the surface. In some implementations, successive points at which the moving object has travelled may be obtained, for example using a suitable global navigation satellite system. These points may be used to obtain the proper digitised map of the location and areas travelled. For example, latitudinal, longitudinal and altitudinal coordinates may be obtained for successive positions of the moving object.
[0078] In some implementations, it is preferred that the correlation of the moving image and the map may be displayed as a path profile. A path profile is a two-dimensional diagram or schematic showing the path taken by the object over the surface, including latitudinal, longitudinal, and altitudinal plots.
[0079] In some implementations, it is preferred that the moving object 111 is a golf ball and the surface 120 is a putting green.
[0080] FIG. 2 shows a block diagram of the correlation of a captured image of the present invention and a digitised map.
[0081] At 210 , a moving image of an object such as a golf ball 111 on putting green 120 or other playing surface is captured. In some implementations, the moving image capture is of images of a golf ball on a putting green. For example, a user, such as “Tiger,” may be golfing on the putting green. A moving image capture may be generated of the golf shot that Tiger made from point X to point Y.
[0082] At 220 , after capturing of said moving image a digitised map 180 of the location of the putting green is obtained. The digitised map may include one or more of the following: a map of the entire putting green 120 ; and contour information of the surface of the putting green 120 . As mentioned above, in some implementations, the geo-spatial position and orientation of the video camera(s) used to capture the moving image relative to the putting green 120 is recorded, to allow the captured moving image to be correlated with a digitised map of the surface. Alternatively, the moving image may be analysed using a processor to identify one or more characteristic features of the surface which may then be aligned with the same features in the digitised map of the surface to allow the captured moving image to be correlated with the map. It will be appreciated that the digitised map does not have to be in graphical form, but must comprise data defining the 3-dimensional profile and geo-spatial position of the surface. In cases where the moving image is analysed to identify characteristic features to facilitate correlation of the moving image with the map, the correct map to be compared with the moving image may be determined by recording the geo-spatial position at which the moving image is recorded by means of a GPS or similar receiver positioned at the location of the video camera or incorporated therein.
[0083] At 230 , the moving image capture is correlated with the obtained digitised map 180 such that each point on the image of the surface as captured is mapped to a corresponding point on said digitised map. In this way, the image of the path taken by the object 111 moving over the surface 120 can be mapped onto a corresponding path on the digitised map.
[0084] At 235 , correlation processing of the moving image and the digitised map 180 thus generates information defining the profile of the path taken by the golf ball 111 over the surface of putting green 120 captured at 210 . The correlation process combines moving image data and information from the digitised map 180 to generate a profile 240 of the path taken by the golf ball 111 . The correlated profile 240 may be generated for display at putting green 120 .
[0085] In some implementations, correlated profile 240 may be displayed at other locations such as at a remote user location, at a computer server, at a database, and the like.
[0086] Table 1 below depicts an example of numeric data for a profile diagram
[0000]
TABLE 1
Sample data for correlated profile.
Time
Coordinates of golf ball in X, Y, and Z
Digital image file
45 s
35, 120, 3
X883hgks3.jpg
46 s
33, 125, 5
X883hgks8.jpg
47 s
31, 130, 6
X883hgks6.jpg
48 s
30, 135, 7
X883hgus10.jpg
49 s
33, 140, 9
X883hgks4.jpg
50 s
34, 145, 8
X883hgks9.jpg
51 s
37, 150, 7
X883hgus13.jpg
52 s
38, 155, 6
X883hgus14.jpg
53 s
39, 157, 2
X883hgus22.jpg
54 s
42, 158, 1
X883hgeus1.jpg
55 s
43, 159, 2
X883hgeus4.jpg
[0087] FIG. 3 depicts graphically an exemplary correlation profile of a captured image of a three-dimensional surface of the present invention. Typically, said correlation profile may be displayed visually on a suitable monitor, for example a television screen. In some embodiments, such correlation profile may be superimposed upon video footage of the moving ball, for example, but not necessarily, replay of the captured moving image.
[0088] FIG. 4 depicts a plan view of the path taken by an object travelling over a surface.
[0089] In some implementations, it is preferred that the image capturing device for capturing a moving image of the moving object as it travels over a surface such as golf course 120 be a hand-held device incorporating a camera such as a mobile telephone with a digital camera. Thus, for example, a third party can record the moving image with his mobile telephone's video recording capabilities. As mentioned above, the handheld device should advantageously be capable of recording time code with the captured moving image, so as to record the absolute or relative time at which the moving object is present at each position in the captured moving image.
[0090] In some implementations, it is preferred that the position recording device for recording the geographical position of the location at which the moving image is captured be a GPS receiver.
[0091] Alternatively, the position recording device for recording the geographical position of the location at which the moving image is captured may be a mobile telephone equipped with GPS functionality.
[0092] In some implementations, the position recording device for recording the geographical position of the location at which the moving image is captured may be one or more stationary cameras. Thus, where the movement of the ball over the green is captured using one or more stationary cameras, for example where a golf tournament is being televised, the position and orientation of the one or more cameras relative to the putting green may be used to correlate the image acquired by the one or more cameras with a digitised map of the green.
[0093] In some implementations, it is preferred that the data acquiring device for obtaining a digitised map of said location based on geographical position includes contour information of the surface. In some implementations, the data acquiring device would comprise online geographic information system (GIS) data.
[0094] In some implementations, it is preferred that the processor for processing the captured moving image to generate image information for allowing the image to be correlated with the digitised map include image information defining the surface of the putting green. The image information defining the surface of the putting green may be obtained by a GPS receiver.
[0095] In some implementations, to provide displaying capabilities, the subject matter described herein may be implemented on a device having a display (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) or other visual interface for displaying information to the user and a method by which the user may provide input to the computing system and observe the display.
[0096] In some implementations, it is preferred that the moving object 111 is a golf ball and the surface 120 is a putting green.
[0097] The subject matter described herein may be implemented in an information processing system such as a computing system that includes a back-end component (e.g., a data server), or that includes a front-end component (e.g., a client computer having a graphical user interface, a mobile telephone or a Web browser through which a user may interact with an implementation of the subject matter described herein), or any combination of such back-end or front-end components.
[0098] In some implementations, the computing system may be configured, e.g., by means of appropriate software, to determine from the position of the object moving over the surface and the associated time code the instantaneous velocity of the object. For instance, by correlating the captured moving image with the map to determine the path of the moving object over the surface in three dimensions, the instantaneous velocity of the object as it moves along the path can be determined by reference to the recorded absolute or relative time at which the moving object is at each position. Such instantaneous velocity may be calculated, for example, by differentiating the information defining the position of the moving object on the path with respect to time.
[0099] Similarly, the acceleration (or ‘drive’) of the moving object may be calculated by the computing system by differentiating such instantaneous velocity information.
[0100] As mentioned above, the information about the path taken by the moving object over the surface may be displayed to a user graphically, e.g., on a suitable monitor. Such information may include, as illustrated in FIG. 5 , the profile of the path taken by the object in two dimensions, including optionally the height of the path relative to an arbitrary datum, as well as the instantaneous speed and/or acceleration (‘drive’) of the object.
[0101] The foregoing description is intended to illustrate but not to limit the scope of the invention, which is defined by the scope of the appended claims. Other embodiments are within the scope of the following claims. | The subject matter disclosed herein provides methods and apparatus, including computer program products and computing-system implemented methods, for providing two-dimensional path profiles of three-dimensional spaces or surfaces. In one aspect, there is provided a method. The method may capture a moving image including one or more golf strokes. The correlation process may generate information defining the path taken by the object over a space or surface as defined by a map. Related apparatus, systems, methods, and articles are also described. | 0 |
RELATED APPLICATION
[0001] This application is a divisional application of U.S. application Ser. No. 11/014,771, filed Dec. 20, 2004, which application claims priority under 35 U.S.C. § 119 of Japanese Application No. 2004-338323 filed Nov. 24, 2004 and Japanese Application No. 2003-423598 filed Dec. 19, 2003, and which is a continuation-in-part application of U.S. application Ser. No. 10/849,871, filed May 21, 2004, which application claims priority under 35 U.S.C. § 119 of Japanese Application No. 2003-423598 filed Dec. 19, 2003, all of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to information processing units, such as mobile phones including a PHS (Personal Handyphone System), equipped with a fingerprint sensor and operation keys.
[0004] 2. Description of the Related Art
[0005] Recently, mobile phones have spread at a remarkable pace and have developed as portable information processing units which are equipped with multiple functions including not only simple telephone functions, but also e-mail functions and enhanced memory functions for storing various personal information such as telephone numbers.
[0006] Big problems posed by such development of mobile phones include illegal use of mobile phones and unauthorized outflow of information stored in mobile phones.
[0007] One of the conventional techniques used to solve these problems involves enabling the use of the mobile phone only when a registered personal identification number is entered.
[0008] Since it is troublesome to enter a personal identification number, mobile phones which are equipped with a fingerprint sensor and are enabled only when a registered fingerprint is detected have recently been proposed and actually put on the market (see, for example, Japanese Patent Laid-Open No. 2002-216116 and Japanese Patent Laid-Open No. 2002-279412). The fingerprint sensor is on a considerably high level in terms of prevention of illegal use and convenience of handling.
[0009] Although it is desirable from a security standpoint to mount a fingerprint sensor on mobile phones, under circumstances where there is demand for size and weight reduction of mobile phones and the mobile phones have been downsized close to the limit considering the operability for users, the question is what fingerprint sensor to mount and in what part of the mobile phones.
[0010] Operation keys and a screen essential for the mobile phones are laid out in such a way as to face the user simultaneously under normal use so that the user can operate the operation key by looking at the screen. Although it is conceivable to install the fingerprint sensor in a space provided on the back face opposite the front face which contains the operation keys and screen, the fingerprint sensor functions as a kind of operation key operated by the user and installing the fingerprint sensor on the back face sacrifices the operability.
[0011] Japanese Patent Laid-Open No. 2002-216116 and Japanese Patent Laid-Open No. 2002-279412 propose the use of a fingerprint sweep sensor which reads a fingerprint as the user moves a finger at right angles to a line sensor consisting of minute sensors arranged one-dimensionally.
[0012] The fingerprint sweep sensor does not require much installation space and can be installed on the front face of the mobile phone without increasing the size of the mobile phone, as shown in Japanese Patent Laid-Open No. 2002-216116 and Japanese Patent Laid-Open No. 2002-279412. Japanese Patent Laid-Open No. 2002-216116 shows a drawing in which the fingerprint sweep sensor is installed adjacent to the operation keys while Japanese Patent Laid-Open No. 2002-279412 shows a drawing in which the fingerprint sweep sensor is installed adjacent to the screen.
[0013] However, if the fingerprint sweep sensor is installed adjacent to the operation keys without taking any measures, there is a danger of pressing operation keys adjacent to the fingerprint sensor by mistake when moving the finger along the fingerprint sensor. Also, if the fingerprint sensor is installed adjacent to the screen, that part of the screen which is adjacent to the fingerprint sensor may become dirty by being touched by fingertips. However, installing the fingerprint sensor on that part of the mobile phone surface which is distant from the operation keys and screen to prevent the above problems would go counter to the demand for size reduction of the mobile phone.
[0014] Also, the fingerprint sweep sensor, which does not require much installation space, can be installed on a flank of the mobile phone. In that case, however, the problem of operability remains, as is the case when the fingerprint sensor is installed on the back face. The above problems are not specific to mobile phones, but are common to information processing units equipped with a fingerprint sensor and operation keys.
[0015] In view of the above circumstances, the present invention has an object to provide an information processing unit which is equipped with a fingerprint sensor and reconciles size reduction with operability at a high level.
SUMMARY OF THE INVENTION
[0016] To achieve the above object, the present invention provides an information processing unit which comprises a casing equipped with a control pad, wherein:
the casing comprises, adjacent to the control pad, a groove which contains a first slope stretching away from the control pad and slanting downward and a second slope stretching further away from the control pad and slanting upward; the groove comprises a fingerprint sensor which detects a fingerprint on a finger moved along the first slope and the second slope; and the first slope and the second slope have mutually different tilt angles.
[0020] In the information processing unit according to the present invention, preferably the fingerprint sensor is a fingerprint sweep sensor.
[0021] In the information processing unit according to the present invention, since the fingerprint sensor is contained in the groove, the first slope of the groove prevents operation keys from being pressed inadvertently when a finger is moved along the fingerprint sensor. Also, the information processing unit allows the user to move the finger along the first slope and second slope by applying it reliably to the fingerprint sensor using both sides of the slopes as a guide. This allows reliable detection of the fingerprint.
[0022] Preferably, the first slope and the second slope have mutually different tilt angles which are determined from the standpoint of preventing misoperation and reliably detecting the fingerprint. In that case, preferably the first slope has a larger tilt angle than the second slope.
[0023] If the fingerprint sensor installed in the information processing unit according to the present invention is a fingerprint sweep sensor, preferably the fingerprint sweep sensor has a surface protruding above an inner surface of the groove. Also, preferably the fingerprint sweep sensor is located in the groove in such a way as to hide a ridge line where an extension surface of the first slope and an extension surface of the second slope meet.
[0024] By making the fingerprint sweep sensor protrude above the inner surface of the groove and lie at the bottom of the groove under which lies a ridge line, it is possible to move the finger in tight contact with the fingerprint sweep sensor, and thus detect the fingerprint reliably.
[0025] As described above, by installing the fingerprint sensor adjacent to the control pad and on the same surface as the control pad, the present invention can reconcile size reduction with operability at a high level.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] FIG. 1 is an external perspective view of a mobile phone according to an embodiment of the present invention;
[0027] FIG. 2 is a plan view showing a part around a fingerprint sweep sensor of the mobile phone 100 shown in FIG. 1 ;
[0028] FIG. 3 is a sectional view taken along A-A line in FIG. 2 ;
[0029] FIG. 4 is a partially enlarged view of the part enclosed by a chain double-dashed line A in FIG. 3 ;
[0030] FIG. 5 is a diagram showing a structure of the fingerprint sweep sensor;
[0031] FIG. 6 is a sectional view of a groove of a mobile phone according to a second embodiment of the present invention; and
[0032] FIG. 7 is a sectional view of a groove of a mobile phone according to a third embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0033] An embodiment of the present invention will be described below.
[0034] FIG. 1 is an external perspective view of a mobile phone which is an embodiment of an information processing unit according to the present invention.
[0035] The mobile phone 100 is a folder type phone which has a top casing 110 and bottom casing 120 pivotably joined by a hinge 130 , where the top casing 110 contains a display screen 111 , ear piece 112 , antenna 113 , etc.; and the bottom casing 120 is equipped with a operation panel 121 , mouthpiece 122 , etc. The bottom casing 120 of the mobile phone 100 contains a V-shaped groove 123 adjacent to and just below the operation panel 121 . A fingerprint sweep sensor 124 is installed at the bottom of the V-shaped groove 123 . Besides, on both sides of the V-shaped groove 123 in the bottom casing 120 are a pair of cushion pads 125 which consist of a soft material (e.g., rubber) protruding a little above the surface of the bottom casing 120 and serve as a cushion to prevent the top casing 110 from coming into direct contact with the bottom casing 120 when the top casing 110 is folded over the bottom casing 120 . According to this embodiment, the cushion pads 125 also serve as orientation marks during fingerprint detection. Details will be described later.
[0036] FIG. 2 is a plan view showing a part around the fingerprint sweep sensor of the mobile phone 100 shown in FIG. 1 , FIG. 3 is a sectional view taken along A-A line in FIG. 2 , and FIG. 4 is a partially enlarged view of the part enclosed by a chain double-dashed line A in FIG. 3 .
[0037] FIG. 2 shows three keys 121 a , 121 b , and 121 c located at the bottom of the multiple keys on the operation panel 121 . The V-shaped groove 123 is located just below the center key 121 b of the three keys 121 a , 121 b , and 121 c at the bottom of the bottom casing 120 .
[0038] The V-shaped groove 123 contains a downward slope 123 a stretching away from the key 121 b and an upward slope 123 b stretching further away from the key 121 b . The V-shaped groove 123 also contains the fingerprint sweep sensor 124 .
[0039] In order for the fingerprint sweep sensor 124 to detect a fingerprint, the user should apply a finger in such a way that the last joint closest to the fingertip is positioned on a straight line joining the two cushion pads 125 and move the finger along the downward slope 123 a and upward slope 123 b in the V-shaped groove 123 in the direction of the arrow indicated by the dotted arrow in FIG. 2 . Consequently, the fingerprint sweep sensor 124 detects the fingerprint on the moved finger.
[0040] As shown in FIG. 3 , the downward slope 123 a and upward slope 123 b of the V-shaped groove 123 have different tilt angles α and β, which satisfy α>β. The tilt angles α and β are determined in such a way as to prevent the key 121 b in FIG. 2 from being pressed by mistake during fingerprint detection and to detect the fingerprint reliably with the fingertip moved in contact with the fingerprint sweep sensor 124 .
[0041] As shown in FIG. 4 , the fingerprint sweep sensor 124 is located at the bottom of the V-shaped groove 123 under which lies a ridge line 123 c where an extension surface of the first slope 123 a and an extension surface of the second slope 123 b meet. Also, the top face 124 a of the fingerprint sweep sensor protrudes by a height b.
[0042] By placing the fingerprint sweep sensor 124 at this position, it is possible to stabilize the finger pressure applied to the fingerprint sweep sensor 124 when the finger is moved along the first slope 123 a and second slope 123 b . This allows the fingerprint to be detected more reliably. However, the fingerprint sweep sensor 124 does not have to be placed at this position and may be placed at another place in the V-shaped groove 123 where the fingerprint can be detected reliably.
[0043] FIG. 5 is a diagram showing a structure of the fingerprint sweep sensor 124 .
[0044] The fingerprint sweep sensor 124 consists of a one-dimensional line sensor 126 , conductive pads 127 installed on both sides of the one-dimensional line sensor 126 , bonding wires 128 which connect the one-dimensional line sensor 126 with the conductive pads 127 , and a mold (not shown). The bonding wires 128 are installed bulging out on both sides of the one-dimensional line sensor 126 . The mold is formed in such a way as to make the V-shaped groove 123 expose only an effective area D in the center by burying the bonding wires 128 . In this way, the V-shaped groove 123 also works effectively to expose only the effective area D of the fingerprint sweep sensor 124 and hide the bulges on both sides in the bottom casing 120 .
[0045] Incidentally, description has been given mainly of the placement location of the fingerprint sweep sensor and surrounding structure (including the V-shaped groove) in a mobile phone, which are typical of the above embodiment, and description of other functions of the mobile phone has been omitted. However, the mobile phone as referred to herein is irrespective of communication schemes and maybe, for example, a PHS (Personal Handyphone System).
[0046] Also, it goes without saying that the information processing unit as referred to herein may be a multifunction unit equipped with not only mobile phone functions, but, also, for example, e-mail functions, camera functions, etc.
[0047] Furthermore, although a clamshell phone has been described herein, the present invention can be applied not only to clamshell phones, but also to various other types of phone. Furthermore, it can be applied to other information processing units such as PDAs (Personal Data Assistants).
[0048] Next, other embodiments of the present invention will be described. The only difference between the following embodiments to be described and the embodiment described with reference to FIGS. 1 to 5 is in the shape of the groove where the fingerprint sweep sensor is disposed. Accordingly, the other embodiments will be described by referring to only a figure that corresponds to and is used in place of FIG. 3 showing the shape of the groove of the above-described embodiment. The reference numerals shown in the following figures used in place of FIG. 3 are the same as those in FIG. 3 and only the different features will be described below.
[0049] FIG. 6 is a sectional view of a groove of a mobile phone according to a second embodiment of the present invention.
[0050] In the above-described embodiment, as shown in FIG. 3 , the first slope that is the downward slope 123 a and the second slope that is the upward slope 123 b are both planes. However, in the second embodiment, each of the downward slope 123 a and the upward slope 123 b is upwardly convex as a whole and these slopes have mutually different tilt angles.
[0051] FIG. 7 is a sectional view of a groove of a mobile phone according to a third embodiment of the present invention. In the third embodiment, each of the downward slope 123 a and the upward slope 123 b is downwardly convex (upwardly concave) as a whole and these slopes have mutually different tilt angles.
[0052] As shown in these other embodiments, the downward slope 123 a and upward slope 123 b is not limited to a plane. The slopes may be designed to any shape as long as they are upwardly or downwardly bulging so as to prevent incorrect key operations and to detect a fingerprint without fail. | The present invention relates to an information processing unit, such as a mobile phone, equipped with a fingerprint sensor and reconciles size reduction with operability at a high level. The present invention is provided, adjacent to a operation panel, with a V-shaped groove which contains a first slope stretching away from the operation panel and slanting downward and a second slope stretching further away from the operation panel and slanting upward, where the V-shaped groove contains a fingerprint sweep sensor which detects a fingerprint on a finger moved along the first slope and the second slope. | 7 |
BACKGROUND OF THE INVENTION
The present invention relates to a small firearm having a receiver for accommodating the system, and a valve which connects the interior of the receiver with the outside and which is designed in such a way that overpressure occurring in the receiver can be evacuated to the outside. There is always a risk in known firearms of the described type that explosive gases may gather in the receiver which may ignite when the firearm is fired. This risk exists in particular when the firearm, which may be an automatic or a semi-automatic weapon, belongs to the class using caseless ammunition where the entire mechanism of the firearm is enclosed in a case which takes the form of the stock and which is in the closed condition when the weapon is ready to fire. If the overpressure occurring when the explosive components ignite in the case is evacuated to the outside through a valve in order to prevent the case from being destroyed, there is the risk that damage may be caused by the hot gases escaping through the valve.
U.S. Pat. No. 2,814,972 describes a firearm with a closed receiver comprising a valve through which an overpressure arising inside the receiver can be evacuated to the outside. The flow path to be taken by the gas is designed as a labyrinth in which the gas is deflected several times and which guarantees that the flame of the burning gas will not emerge from the firearm. However, a labyrinth-like design of the flow path for the gas is very expensive and requires much space.
Further, it has been known from DE-C 25 44 995 to equip firearms having closed receivers with overpressure valves by means of which excessively high pressures occurring inside the firearm can be relieved. However, such relief valves are connected with the disadvantage that they are very sensitive to ingress of dirt, such as sand or the like, and that the cross-sectional surface available as gas outlet is relatively small. The receiver is dust-tight and water-tight, but not gas-tight. The rate of pressure rise inside the firearm is very high, in spite of such relief valves.
SUMMARY OF THE INVENTION
Proceeding from this known state of the art, it is the object of the present invention to design a firearm of the kind described at the outset in such a way that in the event explosive components should ignite inside the receiver the resulting overpressure can be evacuated to the outside without any risk.
The invention achieves this object by the fact that a heat-dissipating solid medium which is permeable to gas is arranged in the area of the valve, in the flow path of the gasses escaping through the valve.
In particular, the medium may consist of a suitable metal, such as steel, which effects rapid cooling-down of the gas flow passing the valve so that the hot gas flow can no longer hurt the shooter. One must consider in this connection that the valve is passed by the hot gas flow not continuously, but only at longer time intervals so that the described medium is permitted to cool down sufficiently during such intervals. The cooling effect can be further supported by bringing the heat-dissipating medium in contact with larger metal parts. Or else the thermal energy can be removed from the gas flow passing the valve by giving the medium a sufficiently high heat capacity in which case it is not necessary for the medium to be in a position to carry off the heat with sufficient rapidity, for example to a holder of the medium. The design using a grate, meshes or a mat presents the advantage that the relatively space-consuming structure of a labyrinth can be avoided.
The advantage of the invention resides in the fact that the heat-dissipating medium, which according to one embodiment of the invention may take the form of a grid, of meshes or mats and which, in particular, may consist of a suitable metal, such as steel, effects rapid cooling-down of the gas flow passing the valve so that the hot gas flow can no longer hurt the shooter. One must consider in this connection that the valve is passed by the hot gas flow not continuously, but only at longer time intervals so that the described medium is permitted to cool down sufficiently during such intervals. The cooling effect can be further supported by bringing the heat-dissipating medium in contact with larger metal parts. Or else the thermal energy can be removed from the gas flow passing the valve by giving the medium a sufficiently high heat capacity in which case it is not necessary for the medium to be in a position to carry off the heat with sufficient rapidity, for example to a holder of the medium.
An additional cooling effect for the gasses can be provoked by the medium if the latter disturbs the laminar flow of the gas so as to create turbulences and a cooling effect.
For design reasons, the medium should conveniently be arranged in the flow cross-section of the valve. Preferably, the medium may be arranged in the flow path of the gasses upstream of a valve gasket so that the gasket will not be exposed to the hot gasses.
Particularly efficient cooling of the gasses can be achieved if according to one embodiment of the invention, at least two heat-dissipating media are provided in the flow path of the gasses at a certain distance one from the other.
According to certain embodiments of the invention, a moving part of the valve may be arranged at the outside of the valve. This protects the inside of the valve efficiently from contamination by dirt penetrating into the firearm from its outside.
According to other embodiments of the invention, the moving part of the valve is arranged near a gas inlet of the valve and a movable cap is arranged at the gas outlet of the valve and is supported resiliently, independently of the moving valve part. The described arrangement of the moving valve part prevents the dirt particles whirling about inside the receiver during use of the firearm from settling in the gas-permeable medium. The gasses reach the medium only when overpressure occurs.
According to one embodiment of the invention, a baffle may be provided for the gas flow in the flow path of the gasses, upstream of the valve gasket, for the purpose of cooling down the gas flow. This baffle guides the gas flow along large-surface of metal parts of the valve whereby it is cooled down efficiently.
BRIEF DESCRIPTION OF THE DRAWING
Other features and advantages of the invention will appear from the claims and from the following description of certain embodiments of the invention given by reference to the drawing which shows essential details of the invention, it being understood that the individual features may be implemented in any embodiment of the invention individually or in any combination thereof. In the drawing
FIG. 1 shows a simplified side view of an automatic firearm, partly broken away;
FIG. 2 shows a longitudinal section through a first embodiment of a valve;
FIG. 3 shows a longitudinal section through a second embodiment of a valve; and
FIG. 4 shows a longitudinal section through a third embodiment of a valve.
DETAILED DESCRIPTION
The simplified view of FIG. 1 shows that the firearm 1, which comprises a receiver 2 accommodating the mechanism of the firearm--not shown in the drawing--comprises a valve 5--indicated only diagrammatically--which is arranged in a receiver wall 4 and which opens when an overpressure occurs in the receiver 2. The receiver 2 is water-tight and dust-tight. Except for the valve, the orifice of the barrel is the only opening in the receiver. The valve 5 is located in the area of the stock 6. Without certain special measures, which will be explained in more detail further below, hot gasses escaping from the valve 6 might possibly injure the shooter because the valve 5 is to be located at the indicated position in the illustrated example and is not to be arranged in a different position in this particular design.
The valve is rotationally symmetrical and each of FIGS. 2 to 4 shows the upper half of an axial section.
In FIG. 2, the valve 5 is seated in a bore of the receiver wall 4 of the receiver 2 and fixed therein in a manner not shown in detail. The valve 5 comprises a cylindrical housing 11 with a supporting element 12 having the shape of a disk, which comprises larger openings 14, formed integrally with the valve housing 11 which is arranged at its left end portion, i.e. near the side where the gasses leave the valve. The supporting element 12 serves as support for a wire grid 16 made from steel wire. On its other side, the wire grid 16 is held in engagement with the supporting element 12 by a pressure spring 18 in the form of a coil spring. The other end of the coil spring 18 bears against a disk 20 which, just as the supporting element 12, is provided with openings 22 to serve as passages for the gas. The disk 20 is mounted to slide in the valve housing 11. Seated centrally in the valve housing 11 is a bolt 24 to which the force of the coil spring 18 which acts to the right in FIG. 2 is transmitted via the disk 20 and a spring washer 26 fitted in a groove of the bolt 24 whereby the bolt 24 is biased to the right, as viewed in FIG. 2. The left outer end of the bolt 24 carries a valve disk 28 which rests against a gasket 30 arranged on the outside of the valve housing 11.
When a sufficiently high pressure is exerted on the valve disk 28 from the right, as viewed in FIG. 2, then the valve disk 28 lifts off the gasket 30, against the force of the coil spring 18. The gasses flowing through the valve 5 pass the wire grid 16 whereby they are cooled down so that the gasses escaping to the outside can no longer endanger the shooter or the environment. Additional cooling of the gasses escaping to the outside is effected by the fact that the valve disk 28 deflects the gasses radially to the outside whereby the gas flow is spread additionally.
In the case of the embodiment of a valve 5' illustrated in FIG. 3, the gasket 30' is inserted in a continuous shoulder 32 on a portion of the wall 4' of the receiver of the firearm which is designed as tubular seat for the valve 5'. Elements which are similar to those of the arrangement according to FIG. 2 are identified by primed reference numerals. The embodiment according to FIG. 3 differs from that according to FIG. 2 essentially in that in addition to the wire grid 16' disposed at the same side as in FIG. 2, a further a wire grid, identified by reference numeral 36, is provided near the side where the hot gasses enter the valve. In order to enable a plane wire grid 36 to be used, the disk 42 is also plane, contrary to the arrangement of FIG. 2 where the central portion of the disk 20 displays a funnel-like shape. Again, the disk 42 is mounted to slide in the valve housing 11' and to transmit the force of the coil spring 18' to the bolt 24' and from there to the valve disk 28'.
Referring now to the embodiment illustrated in FIG. 4, primed identical reference numerals are again used to identify identical similar parts. The valve 5" is seated in a base of the receiver wall 4". The valve housing consists of two parts 50 and 11'' which are screwed together. The gasket 30" of the valve 5'' is located in this case near the side where the gas enters the valve, and the spiral spring 56, which again bears against the wire grid 16" arranged near the gas outlet side, bears by its other end upon a movable valve part 52 whose plane flange portion 54 rests against the gasket 30" and whose central portion 58 displays a cup-like deformation pointing to the right in FIG. 4, this cup-like area being engaged by the coil spring 58. The hot gasses arriving from the right, as viewed in FIG. 4, are deflected by a right angle, due to the described shape of the valve portion 52, which thus serves as a deflection means or baffle means, and are caused to flow past the gasket 30", with the valve part 52 in open position. Due to this deflection, the hot gasses sweep over a big area of the valve part 52 whereby they are cooled efficiently. In addition to cooling the gasses the design of the valve part 52 as a labyrinth in the flow path effects a pressure drop between the valve part 52 and the medium. A further pressure drop occurs between the medium and the sealing cap 60. Further cooling occurs as the gasses flow through the wire grid 16". At the point where the movable valve part 28 and the valve disk 28', respectively, are arranged in the case of the valves illustrated in FIGS. 2 and 3, there is provided in FIG. 4 the movable sealing cap 60 which coacts with a gasket 62 in the form of an O-ring. The sealing cap 60 is biased to the right by a relatively weak pressure spring 64 acting between the wire grid 16" on the one side and a spring washer fitted at the bolt 24" on the other side. The spring 64 being weak in relation to the pressure spring 56, the sealing 60 does not increase the flow resistance of the valve too much.
The spring 64 is adapted to the reduced gas pressure acting at the sealing cap 60 so that in border-line cases the valve 52 will lift off without causing the sealing cap 60 to open.
A rigid connection of simplified design between the movable valve part and the sealing cap may be sufficient if the location is selected conveniently to guarantee the shooter's safety. | A hand firearm with a casing in which the system is arranged and a valve leading from the inside of the casing to the outside which is so designed that an overpressure in the casing may be vented to the outside, in which a gas-permeable, heat conducting solid medium is arranged in the region of the valve in the flow path of the gas leaving via the valve in order to prevent any danger from hot gases being forced out of the weapon. | 5 |
This is a division of U.S. patent application Ser. No. 09/607,043, filing date Jun. 30, 2000, now U.S. Pat. No. 6,358,781.
RELATED PATENT APPLICATION
TSMC98-527, A COMBINED NMOS AND SCR ESD PROTECTION DEVICE title filing date: May 3, 1999, Ser. No. 09/304,304, assigned to a common assignee.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to the protection of integrated circuits from electrostatic discharge (ESD), and more particularly to the protection of high voltage NMOS transistors by parasitic silicon controlled rectifiers (SCR) which carry equal currents.
2. Description of the Related Art
The protection of integrated circuits from electrostatic discharge (ESD) is a subject which has received a lot of attention from circuit designers because of the serious damage that ESD can wreak as device dimensions are reduced. Workers in the field and inventors have proposed many solutions, many trying to solve the problem of protecting sub-micron devices while still allowing them to function unencumbered and without undue, or zero, increase of silicon real estate. The main thrust of ESD protection for MOS devices is focused on the use of parasitic npn and pnp bipolar transistors which together form a lateral silicon controlled rectifier (SCR). Unwanted as this SCR normally is, it can safely discharge dangerous ESD voltages as long as its trigger voltage is low enough to protect those MOS devices of which it is a part.
The following publications discuss lateral SCR structures for ESD protection circuits:
“Lateral SCR Devices with Low-Voltage High-Current Triggering Characteristics for Output ESD Protection in Submicron CMOS Technology,” Ker, IEEE Transactions On Electron Devices, Vol. 45, No. 4, April 1999, pp. 849-860.
“Grounded-Gate nMos Transistor Behavior Under CDM ESD Stress Conditions,” Verhaege et al., IEEE Transactions On Electron Devices, Vol. 44, No. 11, November 1997, pp. 1972-1980.
“Design Methodology and Optimization of Gate-Driven NMOS ESD Protection Circuits in Submicron CMOS Processes,” Chen et al., IEEE Transactions On Electron Devices, Vol. 45, No. 12, December 1998, pp. 2448-2456.
“The State of the Art of Electrostatic Discharge Protection: Physics, Technology, Circuits, Design, Simulation, and Scaling,” Voldman, IEEE Journal of Solid-State Circuits, Vol. 34, No. 9, September 1999, pp. 1272-1282.
“The Mirrored Lateral SCR (MILSCR) as an ESD Protection Structure: Design and Optimization Using 2-D Device Simulation,” Delage et al., IEEE Journal of Solid-State Circuits, Vol. 34, No. 9, September 1999, pp. 1283-1289.
FIG. 1 is a cross-sectional schematic of a high voltage protection device layout of the prior art and FIG. 2 is the equivalent circuit. FIG. 1 shows a semiconductor wafer 100 with a p-substrate 102 having two n-wells 104 , and 105 , where n-wells 104 and 105 are NMOS drains. Implanted in n-well 104 are n+ diffusions 106 , 108 , and p+ diffusion 110 (all connected together via connection 122 ). Implanted into p-substrate 102 are p+ diffusion 112 and n+ diffusion 114 to one side of n-well 106 , and n+ diffusion 116 to the other side of n-well 104 . Diffusions 112 , 114 , and 116 are all connected to a reference potential 124 (typically ground). NMOS transistor T 1 is formed by n-well 104 , n+ diffusion 114 (source), and gate 118 . NMOS transistor T 2 is formed by n-well 104 , n+ diffusion 116 (source), and gate 120 . SCR 1 consists of parasitic bipolar pnp transistor Q 1 and parasitic bipolar npn transistor Q 2 which are formed by p-substrate 102 , n-well 104 and diffusions 110 , and 114 . SCR 2 consists of parasitic bipolar pnp transistor Q 1 and parasitic bipolar npn transistor Q 3 which are formed by p-substrate 102 , n-well 104 and diffusions 108 , and 116 . Resistors R 1 , R 3 ′ and R 3 ″ are equivalent resistors for the intrinsic resistance of the p-substrate 102 material. Resistors R 2 , and R 4 are equivalent resistors for the intrinsic resistance of the n-well 104 material. Another set of NMOS transistors are arranged in a mirror image around n+ diffusion 116 .
FIG. 2, the equivalent circuit of FIG. 1, shows typical parasitic silicon controlled rectifiers SCR 1 and SCR 2 , which are comprised of Q 1 , Q 2 , R 1 and R 2 , and Q 1 , Q 2 , R 3 ′ and R 4 , respectively. Note that in the figures like parts are identified by like numerals. Connected in parallel between connection 122 and reference potential 124 are shown the NMOS transistors T 1 and to T 2 which are protected by the action of the SCRs. Note that SCR 1 sees a different resistance (R 1 ) than SCR 2 (R 1 +R 3 ′, where R 3 ′ is between Nodes A and B). Therefore SCR 2 turns on easier and has to dissipate more current than SCR 1 . The non-uniform current distribution is very undesirable, because it limits the maximum voltage that the ESD protection device can withstand. The number of NMOS transistors is not limited to the two shown but depends on the current capacity desired and may be more than two as indicated in FIG. 1 .
Other related art is described in the following U.S. Patents which propose low voltage lateral SCRs (LVTSCR), modified lateral SCRs (MLSCR), PMOS-trigger lateral SCRs (PTLSCR), NMOS-trigger lateral SCRs (NTLSCR), and modified PTLSCRs and NTLSCRs to control electrostatic discharge:
U.S. Pat. No. 5,959,820 (Ker et al.) describes a cascode low-voltage triggered SCR and ESD protection circuit.
U.S. Pat. No. 5,905,288 (Ker) describes an output ESD protection circuit with high-current-triggered lateral SCR.
U.S. Pat. No. 5,872,379 (Lee) describes a low voltage turn-on SCR for ESD protection.
U.S. Pat. No. 5,754,381 (Ker) provides a modified PTLSCR and NTLSCR, and bypass diodes for protection of the supply voltage and output pad of an output buffer.
The trigger voltage is the low snap-back trigger voltage of a short-channel PMOS (NMOS) device.
U.S. Pat. No. 5,754,380 (Ker et al.) is similar to U.S. Pat. No. 5,754,381 above but without bypass diodes. The invention requires a smaller layout area than conventional CMOS output buffers with ESD protection.
U.S. Pat. No. 5,745,323 (English et al.) shows several embodiments for protecting semiconductor switching devices by providing a PMOS transistor which turns on when an electrostatic discharge occurs at the output of the circuit.
U.S. Pat. No. 5,576,557 (Ker et al.) provides ESD protection for sub-micron CMOS devices supplying discharge paths at V dd and V ss using two LVTSCRs. In addition a PMOS device is used in conjunction with one LVTSCR and an NMOS device with the other LVTSCR. Inclusion of the PMOS and NMOS devices allows lowering of the trigger voltage to 11-13 Volt.
U.S. Pat. No. 5,572,394 (Ker et al.) describes a CMOS on-chip four-LVTSCR ESD protection scheme for use in Deep submicron CMOS integrated circuits.
U.S. Pat. No. 5,455,436 (Cheng) describes an SCR ESD protection circuit with a non-LDD NMOS structure with a lower avalanche breakdown level than the LDD NMOS device of an output buffer.
It should be noted that none of the above-cited examples of the related art provide a symmetrical layout of components of the ESD device with a resultant uniform distribution of currents in the parasitic SCRs and thus achieving a combination of high Human Body Model (HBM) ESD Passing Voltage equal to the machine limit of 8 kVolt and a Machine Model voltage of 800V/850Volt.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an ESD device for protecting NMOS high power transistors where the SCR protection device and the NMOS transistors are integrated.
Another object of the present invention is to provide uniform current distribution in the parasitic SCRs associated with the NMOS transistors to provide increased ESD protection limits for the NMOS circuits.
A further object of the present invention is to provide HBM ESD Passing Voltage which equals the machine limit of 8,000 Volt.
A yet further object of the present invention is to provide Machine Model ESD Voltage with a pass/fail range of 800/850 Volt.
These objects have been achieved by designing the ESD device with its two NMOS transistors and its attendant parasitic SCRs in a completely symmetrical arrangement so that the currents are completely uniform in the components which are symmetrical (such as resistors and parasitic bipolar transistor). This symmetry is achieved specifically by adding a p+ diffusion to the source of one of the NMOS transistors. The added p+ diffusion insures that the resistance seen by both SCRs is the same, thus insuring that the current through both SCRs is identical, thereby creating identical turn-on conditions for both SCRs.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional view of NMOS transistors and their associated parasitic SCRs of the prior art.
FIG. 2 is an equivalent circuit diagram of FIG. 1 .
FIG. 3 is a cross-sectional view of NMOS transistors with their associated parasitic SCRs (showing the symmetric layout of parasitic resistors R 1 and R 3 ) of the preferred embodiment of the present invention.
FIG. 4 is an equivalent circuit diagram of FIG. 3 .
FIG. 5 is a block diagram of the method of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
We now describe the preferred embodiment of an integrated circuit and a method of fabrication of an electrostatic discharge (ESD) device where the latter is part of high voltage NMOS transistors and where the ESD device, in the form of two parasitic SCRs, is integrated with these NMOS transistors.
Referring now to FIG. 3, we show the preferred embodiment of the present invention. FIG. 3 is a cross-sectional view of two n-channel metal oxide semiconductor (NMOS) transistors with two parasitic silicon controlled rectifiers (SCR), where the SCRs are created by p+ diffusion 110 in NMOS drain 104 . Similar to FIG. 1, the number of NMOS transistors is not limited to the two NMOS transistors discussed(T 1 and T 2 ). A second set of NMOS transistors can be realized by mirror imaging (around p+ diffusion 113 ) the layout of transistors T 1 and T 2 . FIG. 3 shows two additional NMOS transistors and associated parasitic SCR ESD protection devices (SCR 3 , SCR 4 ) which are duplicated by mirroring around the third p+ diffusion 113 . It is obvious to those skilled in the art that any number of ESD protection devices can be created similarly to meet the current requirements of the circuit. In the figures (FIG. 1, 2 , 3 , and 4 ) like parts are identified by like numerals.
In FIG. 3, the ESD protection and the high voltage NMOS transistors comprise a semiconductor wafer 100 with a p-substrate 102 with n-well 104 formed in the p-substrate. N-well 104 forms the drain of first and second NMOS transistors T 1 and T 2 .
First and second n+ diffusions 106 , 108 are implanted in n-well 104 . Between diffusions 106 and 108 is implanted a first p+ diffusion 108 . Second and third p+ diffusion 112 , 113 are implanted in p-substrate 102 at opposite sides of n-well 104 . A third n+ diffusion 114 is implanted in the p-substrate between n-well 104 and second p+ diffusion 112 , the third n+ diffusion 114 representing the source of first NMOS transistor T 1 . A fourth n+ diffusion 116 is implanted in the p-substrate between n-well 104 and third p+ diffusion 113 , the fourth n+ diffusion 116 representing the source of the second NMOS transistor T 2 . A first gate 118 formed between n-well 104 and third n+ diffusion 114 represents the gate of first NMOS transistor T 1 . A second gate 120 formed between n-well 104 and fourth n+ diffusion 116 represents the gate of second NMOS transistor T 2 . Diffusions 106 , 108 , and 110 are connected together by conductive means 122 . Diffusions 112 , 113 , 114 , and 116 are tied to a reference potential 124 (typically ground). Note that p+ diffusion 110 provides symmetry for the NMOS transistors, and, more importantly, newly added p+ diffusion 113 provides symmetry for SCR 1 and SCR 2 , by connecting R 3 from the base of Q 3 to reference voltage 124 , thus creating a mirror image with R 1 , and thereby ensuring that the two SCRs conduct the same current.
The structure as described creates a first parasitic silicon controlled rectifier SCR 1 and a second parasitic silicon controlled rectifier SCR 2 . Still referring to FIG. 3, SCR 1 further comprises:
a first parasitic pnp bipolar transistor Q 1 , having its emitter, base, and collector formed by first p+ diffusion 110 , n-well 104 , and p-substrate 102 , respectively,
a first parasitic npn bipolar transistor Q 2 , having its emitter, base, and collector formed by third n+ diffusion 114 , p-substrate 102 , and n-well 104 , respectively,
a first parasitic resistor R 1 between second p+ diffusion 112 and p-substrate 102 , where R 1 represents the intrinsic resistance of the p-substrate between the base of Q 2 and diffusion 112 ,
a second parasitic resistor R 2 between first n+ diffusion 106 and n-well 104 . R 2 represents the intrinsic resistance of the n-well between the base of Q 1 /collector of Q 2 and diffusion 106 .
SCR 2 further comprises:
first parasitic pnp bipolar transistor Q 1 , as described above,
a second parasitic npn bipolar transistor Q 3 , having its emitter, base, and collector formed by fourth n+ diffusion 116 , p-substrate 102 , and n-well 104 , respectively;
a third parasitic resistor R 3 between third p+ diffusion 113 and p-substrate 102 , where R 3 represents the intrinsic resistance of the p-substrate between the base of Q 3 and diffusion 113 ,
a fourth parasitic resistor R 4 between second n+ diffusion 108 and n-well 104 . R 4 represents the intrinsic resistance of the n-well between the base of Q 1 /collector of Q 3 and diffusion 108 .
The benefits of the present invention will be further demonstrated by inspection of FIG. 4, which is the equivalent circuit diagram of FIG. 3 . FIG. 4 shows transistors T 1 and T 2 connected between conductive rail 122 and reference potential 124 . SCR 1 and SCR 2 are connected similarly between rails 122 and 124 . FIG. 4 reveals the symmetry of SCR 1 and SCR 2 , where transistor Q 1 is shared between the two SCRs. Resistor R 3 is now connected between Node B and p+ diffusion 113 , whereas in the prior art (see FIG. 2) resistor R 3 ′ was connected between Nodes A and B, and resistor R 3 ″ was connecting the base of transistor Q 3 with the base of its mirror image transistor Q 3 ′. R 3 ′, thus contributed to an uneven current distribution. Note that in FIG. 4 the path from the collector of Q 1 to Q 2 to R 1 to rail 124 is identical to the path from the collector of Q 1 to Q 3 to R 3 to rail 124 . Therefore, the current from Q 1 via Q 2 , R 1 , and 124 is the same as the current from Q 1 via Q 3 , R 3 to rail 124 . In addition to the asymmetry of the prior art just described, there is in FIG. 2 another asymmetry which has been eliminated by the present invention. In FIG. 2 bipolar parasitic transistor Q 3 is connected via parasitic resistor R 3 ″ to the mirror image transistor Q 3 ′. In contrast, in FIG. 4 resistor R 3 is tied to p+ diffusion 113 and therefore uncoupled from the “mirror image resistor R 3 m” which is created when p+ diffusion 113 is the centerline for the mirror image of another set of NMOS transistors and parasitic SCRs. Diffusions 106 , 108 , 110 , 112 , 113 , 114 , and 116 are indicated for clarification of FIGS. 2 and 4.
Because in the prior art (per FIGS. 1 and 2 ):
R 1 +R 3 ′>R 1
SCR 2 turns on easier and has to dissipate more current. In the new device (per FIGS. 3 and 4) the turn-on condition for SCR 1 and SCR 2 is identical because:
R 1 =R 3
i.e., the same amount of current is dissipated by SCR 1 and SCR 2 .
It follows from the above that the preferred embodiment of the present invention provides these advantages:
a) The current distribution between the first SCR (SCR 1 ) and the second SCR (SCR 2 ) is uniform.
b) The turn-on time for both SCRs is the same.
c) The turn-on conditions for both SCRs are identical.
Experiments conducted with the circuit of the invention are tabulated in Table 1. They indicate an increase of the Human Body Model pass/fail voltage from 6 kV/6.5 kV of the prior art to 8 kV, which is the machine limit. The specification calls for a pass/fail voltage of 2 kV. Table 1 also shows that the Machine Model voltage increased from 350V/400V for the device of the prior art to 800V/850V for the invention (the Machine Model involves higher currents).
TABLE 1
Human Body Model
Summary
pass/fail voltage
Machine Model
old structure
6 kV/6.5 kV
350 V/400 V
new structure
8 kV
800 V/850 V
We now discuss the method of this invention of protecting high voltage n-channel metal oxide (NMOS) semiconductor transistors from electrostatic discharge (ESD) by parasitic silicon controlled rectifiers (SCR), by reference to FIG. 5 .
a) BLOCK 51 describes forming an n-well in a p-substrate, where the n-well is the drain of a first and a second NMOS transistor.
b) in BLOCK 52 a first and second n+ diffusions is implanted in the n-well.
c) in BLOCK 53 a first p+ diffusion is implanted between the two n+ diffusions of the previous step.
d) next there follows in BLOCK 54 the implanting of a second and a third p+ diffusion in the p-substrate at opposite sides of the n-well.
e) in BLOCK 55 there is implanted a third and a fourth n+ diffusion (the source for each of the two transistors) in the p-substrate between the n-well and the p+ diffusions of the previous step and adjacent to them.
f) in BLOCK 56 a gate is formed for each of the two NMOS transistors between the n-well and the third and fourth n+ diffusions at either side of the n-well.
g) BLOCK 57 connects through conductive means the drains of the two transistors.
h) BLOCK 58 connects the sources of the two transistors and the two adjacent p+ diffusions to a reference potential.
Note that the components described in the steps above from BLOCK 53 through 58 are arranged symmetrically around the p+ diffusion 110 . This symmetrical layout insures that SCR 1 and SCR 2 are also arranged symmetrically, including the number and size of the parasitic resistances R 1 -R 4 and the parasitic bipolar transistors. This symmetrical layout ensures a uniform current distribution in the two parasitic SCRs which results in turn-on conditions for SCR 1 and SCR 2 being identical. The uniform current distribution has been confirmed through scanning electron microscopy (SEM) which shows a uniform photo-emission (e-/hole recombination) of the “four fingers” of a layout designed according to the principles of the present invention. In similar SEM photos of devices designed according to the principles of the prior art, only two fingers (the inner ones) show a significant dissipation of current.
The method of the present invention, therefore, protects the first and said second NMOS transistor mentioned in BLOCK 51 from ESD because the current distribution of a first and second intrinsic parasitic SCR is even. The method of the present invention also allows the aforementioned first and said second NMOS transistors to be duplicated by mirroring them around either the second or third p+ diffusion (refer to BLOCK 54 ).
While the invention has been particularly shown and described with reference to the preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made without departing from the spirit and scope of the invention. | NMOS transistors for a high voltage process are protected from electrostatic discharge (ESD) by parasitic SCRs, where the two NMOS transistors and the two SCRs are designed to be in a completely symmetrical arrangement so that the currents in the components of the SCRs are completely uniform. This symmetry is achieved by adding a p+ diffusion to the source of one of the NMOS transistors. The added p+ diffusion guarantees that the resistance seen by both SCRs is identical. This insures even current distribution between both SCRs and thereby improves the high voltage characteristics of the ESD device. | 7 |
CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation of U.S. application Ser. No. 11/181,280 filed Jul. 14, 2005, now U.S. Pat. No. 7,937,249.
FIELD OF THE INVENTION
This invention relates to the measurement and determination of biomechanical properties of internal tissues or organs of a living body, such as a human body.
BACKGROUND
Understanding the biomechanical properties of body tissues, particularly internal tissues or organs, is useful for the development of improved medical diagnostic and treatment tools. In addition, understanding the biomechanical properties such as the elastic and visco-elastic properties of internal tissues or organs can aid in designing more safe, comfortable and effective devices for internal use. Biomechanical implications learned from these measurements can improve not only the design of medical devices and implants used for minimally invasive surgery, but also any other products interacting with body tissues. As an example, knowledge of biomechanical properties can help in developing a better understanding of the effects of internally worn devices such as tampons on the deformations in internal tissues to the point of affecting comfort and effectiveness.
External tissues and organs such as the stratum corneum and epidermis can be relatively easily characterized for in vivo mechanical properties because of easy accessibility and locating the point of measurement. However, internal tissues and organs, such as intra-abdominal tissues, intra-vaginal tissues, intra-uterine tissues, intra-esophageal tissues, and the likes are more difficult to characterize. In particular, in-vivo measurements of internal tissues to obtain biomechanical properties are difficult due to limited accessibility nature of such tissues and difficulties associated with locating the point of measurement. The constraints of available devices and techniques to reach these tissues, as well as the difficulty of obtaining accurate data under in vivo condition has hampered efforts at accurately modeling of ‘living’ internal tissue biomechanical properties.
In-vivo measurements of internal tissues properties of organs such as the vagina are particularly difficult to achieve. The human female vagina is located in the lower pelvic cavity and surrounded by the major organs such as the uterus, the bladder, and the rectum. The vagina is a collapsed tube-like structure composed of fibromuscular tissue layers. The central portion has an H-shaped cross section and its walls are suspended and attached to the paravaginal connective tissues. The vaginal inner walls have rugal folding which is extended significantly during delivery. Smooth muscle fibers are oriented along the vaginal axis and arranged circularly toward the periphery. Vaginal walls are connected to the lateral pelvic floor by connective tissues and smooth muscle layers, which allow the vagina to be deformed and displaced easily according to the external strain energy applied.
The pelvic environment comprises a soft tissue and muscle “hammock” to which the various organs are attached. For example, the vagina is connected to the pelvis by the pelvic floor muscles and connective tissue. Because of its location within pelvic cavity, the degree of vaginal tissue deformation is significantly influenced by the biomechanical properties of surrounding organs and tissues. Furthermore, because there is no rigid supporting structure around the vagina, but connective tissues of smooth muscle fibers among the surrounding organs, it is important to understand not only deformation of vaginal tissues, but also surrounding organs' boundaries for complete measurement of biomechanical properties and parameters of vaginal and surrounding tissues. Among the surrounding organs of vagina, the bladder is the most influential organ in a way that the vaginal tissue responds to external strain; as the bladder expands by accumulating urine, it stretches toward vesicovaginal tissue layers. The apparent physical change is deformation (stretching and/or compaction) of tissue layers, which can in turn impact the stiffness of tissue layers. Interactions among the lower pelvic floor organs make the in vivo measurement of vaginal tissue more challenging work. Therefore, these anatomical complexities of the vagina and surrounding tissues and organs require that biomechanical properties be obtained by considering the heterogeneous and inhomogeneous nature of the related human anatomy, and interactions of neighboring organs and tissues.
Accordingly, there is a continuing unaddressed need for better devices and methods for determining biomechanical properties of internal tissues and organs. The new measurement method is preferably non-invasive or at least minimally invasive, so the mechanical properties of the original tissues are well maintained while the measurement is underway.
Further, there is a continuing unaddressed clinical need for devices and methods for measuring biomechanical tissue properties in-vivo, such that the effects of surrounding tissues and organs are taken into account.
Additionally, there is a continuing unaddressed need for a device and method for determining the biomechanical properties of different portions of the same tissue or organ.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A-1B are a schematic representation of a device of the present invention and some key measurement positions along the vagina axial path.
FIGS. 2A-2B are one embodiment of tissue strain device, in this case, a latex balloon attached to a closed line of fluid.
FIGS. 3A-3C are a schematic representation of manual operation and stepping-motor driven fluid volume controllers.
FIG. 4 is an optical switch and its signal generated for the temporal alignment of stress signals.
FIGS. 5A-5D are an illustrative representation of an ultrasound image that was found useful example for the present invention.
FIG. 6 is one embodiment of ultrasound image processing using MatLab for the calculation of axial strain.
FIGS. 7A-7B are one embodiment of the strain measurement based on the image processing of a ultrasound B-Cine mode.
FIG. 8 is one embodiment of ultrasound B-Cine mode image analysis using MatLab for the strain measurement.
FIGS. 9A-9B are the instrumentation scheme for the calibration of pressure transducer, and one typical example of calibration result.
FIG. 10 is one embodiment of a signal analysis using MatLab for the measurement of in vivo tissue loading stress.
FIGS. 11A-11B are the concept of transient stress signal analysis for the measurement of viscosity related parameters of in vivo tissue.
FIG. 12 is the typical strain level varying for different measurement locations which correlate to those indicated in FIG. 1B .
FIG. 13 is the typical long term and short term stress levels varying for different measurement locations which correlate to those indicated in FIG. 1B .
FIG. 14 is a graph showing a relationship between the pressure change measured by the pressure transducer of the present invention and the volume change of the expandable tissue strain device of the present invention.
SUMMARY OF THE INVENTION
A computational model of the internal human pelvic environment is disclosed. The model comprises meshed finite element regions corresponding to internal tissues or organs selected from the group consisting of pelvic muscles, vagina, vaginal walls, intestinal tissues, bowel tissues, bladder, bladder walls, cervix, and combinations thereof.
DETAILED DESCRIPTION OF THE INVENTION
The method and device of the present invention overcomes the technical challenges and problems associated with determining in vivo the biomechanical properties of tissues. In particular, the method and device of the present invention can be used to determine location dependent biomechanical properties, i.e., properties that are specific to a particular location in the body and/or on a particular tissue. The method and device of the present invention can include a measurement system in a combined format of a strain gauge type physiological pressure transducer to measure the tissue loading stress, and imaging devices such as a CT, a magnetic resonance imaging (MRI), or an ultrasound imager to measure localized tissue strain profiles. Such imaging devices permit non-invasive, externally disposed probes to be utilized for the purpose of making measurements of static or dynamic tissue deformation. The method of the present invention also comprises a modeling internal tissues of a body by numerical methods, including finite element analysis.
A device of the present invention is shown in FIG. 1A , which shows a device 10 of the present invention that can be used to determine biomechanical properties of internal tissues of a body 12 which can be a human or an animal. The device 10 can be used to measure biomechanical properties inside the vagina 14 of a female. However, the device 10 can be used to determine biomechanical properties of any internal tissues and organs that can be accessed through body orifices sufficiently large for insertion of the internally-disposed portions of the device.
The device 10 of the present invention can be used to measure stress and strain of internal tissues. For example, when used to measure vaginal tissue properties, as in the embodiment illustrated herein, representative stress and/or strain measurement positions can be those shown in FIG. 1B from “Near Introitus” to “Under Cervix” along the axial direction of vaginal path toward cervix. However, measurement of stress and strain profiles can be done anywhere along the vaginal path as long as the imaging modality can visualize the location properly for the strain analysis. The location can be easily identified when the imaging modality shows the vagina and surrounding organs clearly. Two fiducial points, ie., the introitus and the cervix can be identified first and then the entire vaginal path can be divided into six sections as shown in FIG. 1B , such as sections 1 , 2 , 3 , and 4 associated with the mid-vagina, and a section labeled as near cervix.
The device 10 includes at least four main parts: an expandable tissue strain device 30 , a pressure transducer 40 , a fluid volume controller 50 , and an imaging device, which can be an external imaging device 60 , 62 . The expandable tissue strain device 30 can be a probe, such as an inflatable probe comprising medical grade elastomers such as urethane or latex that induces strain to tissues. Both urethane and latex can have very low moduli, about 2-2.5 M Pa, with latex exhibiting a modulus of about 2.2 MPa under a 500% extension from its original dimension. Suitable urethane elastomers can be purchased from Advanced Polymers Inc. as 25000001AB low durometer urethane.
In the illustrated embodiment the expandable tissue strain device 30 is an inflatable latex balloon 32 . Latex balloon 32 can be sized so as to fit into the necessary body opening. In the illustrated embodiment, latex balloon 32 can fit through and into the female vagina 14 as shown in FIG. 1A . Latex balloon 32 can be made from surgical latex material, and can comprise the finger portion of a latex glove. For example, in one embodiment, latex balloon comprises the fifth finger (i.e., the pinky finger) of a Microtouch® latex surgical glove, size 6, lot number 124-937, purchased from Johnson & Johnson. The size of latex balloon 32 can be varied as appropriate for the intended body opening. In the illustrated embodiment, latex balloon 32 can have an internal volume of between about 0 ml (when totally collapsed) to about 30 ml. Testing has shown that for that range of volume change, the average axial dimension (i.e., the diameter for a round balloon) can change from about 10 mm to about 40 mm.
Strain transducer 30 , such as inflatable latex balloon 32 , can be operatively connected to a pressure transducer 40 by any suitable means, including by tubing 42 . Tubing 42 can be relatively rigid tubing, such that pressure differentials have little or no effect on tubing volume. In one embodiment tubing 42 has a modulus at least twice that of strain transducer 30 , such as inflatable latex balloon 32 . In this manner, pressure changes applied on the inserted balloon 32 can be accurately detected by pressure transducer 40 . In one embodiment latex balloon 32 is attached to VWR Brand® 5/32 inch ID PCV tubing, catalog number 60985-516, FDA/USDA/USP-VI Certified Lab/Food/Medical Grade available from VWR International Inc. (West Chester, Pa.).
As shown at FIG. 2A , the latex balloon 32 can be joined to tubing 42 in any suitable manner sufficient to hold a pressure tight seal over the range of pressures required for the particular body portion of interest. In one embodiment the latex balloon was joined to the tubing by placing the open end of the balloon over the end of a section of PVC tubing, wrapping with orthodontic rubber bands available from Ormco Z-pak Elastics (Ormco Corp. Glendora, Calif.), and then overwrapping with Tagaderm® tape, 81 , as shown in FIG. 2A . Tagaderm® tape, available from 3M (St. Paul, Minn.) was added in an amount sufficient to ensure a pressure tight seal, that is, sufficient to seal against pressure losses over the range of pressures required for the particular body portion of interest.
The other end of the tubing 42 is operatively connected to an input port 44 of pressure transducer 40 , as shown in FIG. 1A and FIG. 2B . Connection can be by any suitable means, including adhesive attachment, tape sealing, or thermal melt bonding. Pressure transducer 40 can be any of known static/dynamic strain gauge type pressure transducers for detecting changes in fluid pressure inside tubing. For the sake of safety to a body, 12 , a medical grade pressure transducer can be utilized. In one embodiment, pressure transducer 40 is a Gould Spectramed® Model P23ID physiological pressure transducer available from Gould (Valley View, Ohio). Pressure transducer 40 generates signals that can be amplified and filtered through a signal conditioning amplifier 46 . Signal conditioning amplifier 46 can be any of known signal amplifiers suitable for strain gauge type pressure transducers, and in one embodiment it can be a physiological pressure transducer amplifier, DA 100C available from BIOPAC® Systems, Inc (Goleta, Calif.). The BIOPAC® signal conditioning amplifier can be used with companion modules such as isolated power supply module, IPS100C and output signal isolator, OUTISO available from the same manufacture. Amplified and filtered signals can then be digitized by use of a data acquisition module 48 , such as a USB Function Module for data acquisition, DT9803, available from Data Translation Inc. (Marlboro, Mass.). Once signals are digitized, they can be collected, analyzed, or otherwise manipulated by means of a computer 70 .
A second port, such as output port, 45 of pressure transducer 40 is joined to tubing 43 that can be identical to tubing 42 . Tubing 43 connects pressure transducer 40 to fluid volume controller 50 . Fluid volume controller 50 can be any of known devices for managing the volume of fluid present in the device 10 , particularly the volume and rate of change of volume of an expandable tissue strain device 30 such as an inflatable balloon 32 . Tubing 43 can be joined in any suitable manner at both ends, including by adhesive attachment, tape sealing, or thermal melt bonding.
In one embodiment shown in FIG. 1A , the fluid volume controller 50 comprises a syringe device comprising a syringe housing 52 , a syringe plunger 54 and mounting hardware including any of various known clamps 55 . Syringe housing 52 can have any suitable volume for the intended purpose; various sizes of syringes are available to meet the various volume change needs. In one embodiment syringe housing 52 has a volume of 50 ml. Syringe plunger 54 can be operated manually. However, for greater accuracy of measured parameters, syringe plunger 54 can be linearly positioned by syringe plunger pushing device 56 that can comprise any of known linear positioning devices, such as drive shaft 57 mounted on linear shaft guide as known in the art.
The fluid volume controller 50 shown in FIG. 1A operates in a similar manner as a simple syringe-type mechanism as shown in FIG. 2B . However, for precision control of fluid volume increase in the balloon 32 , two different embodiments of fluid volume controller can be used: manual positioning of syringe plunger 54 as shown at FIG. 3A and automatic means as shown with reference to FIGS. 3B and 3C . Fluid volume controller 50 can be operated by manual control of syringe volume, 96 . Before the operator pushes the manual pushing plate 101 , he or she can adjust the pushing plate positioning guide 102 to set the initial syringe volume position, which allows repeatable volume change. The net change of syringe volume is determined from the stroke length 105 of the syringe plunger 54 . The plunger stroke is matched with travel distance 106 of manual pushing plate 101 . This travel distance is in turn set by the adjustable limiter positioning guide 100 . Once the operator determines the desired volume change, distance 106 can be set by securing limiter clamp 98 , thereby making volume change repeatable. Because both the syringe drive shaft 93 and syringe plunger 54 are conjoined by the syringe coupling 91 , the movement of manual pushing plate 101 and syringe plunger 54 are synchronized. These controlled mechanical motions drive the syringe 52 of FIG. 2B or 96 FIG. 3A in a controlled and repeatable manner, and maintain the strain energy applied on the tissue at a predetermined and calibrated level.
The syringe plunger pushing device 56 of FIG. 1A can be either a manual pushing mechanism as described above and shown in FIG. 1A and FIG. 3A , or a motor driven system as shown in FIGS. 3B and 3C . Motor driven systems can use a stepper motor to control the volume change rate more precisely. In one embodiment the stepping motors can be a DRL Series Compact Linear Actuator and Driver System from the Oriental Motors (Torrance, Calif.).
FIG. 3B shows a linear actuator stage 116 that includes an actuator motor 113 and a motor controller 114 coupled to plunger pushing handle 95 with simple mating screws 111 . As shown at FIGS. 3B and 3C , the linear motion generated by the linear actuator motor, 113 , is delivered to the existing plunger pushing handle, 95 through a connecting rod, 112 . Therefore, this design allows easy attachment and detachment of motor driven fluid volume controller according to the necessary test protocols. In one embodiment a computer control signal 115 generates the control signal to operate the linear motion motor 113 . Computer control signal 115 can be from a program specifying a specific tissue strain protocol. Linear motion is transferred to syringe drive shaft 93 of FIG. 3A which drives syringe plunger 54 of FIG. 2B . Precision control of fluid volume is particular useful for the measurement of creep and relaxation of viscous property of tissue.
As shown in FIG. 3A , an optical switch 92 detects the moment when the syringe plunger 54 of FIG. 2B travels a predetermined distance, i.e., a stroke length. Optical switch 92 can generate a digital compatible signal that can be sent to the data acquisition module 48 of FIG. 1A . The optical switch 92 is structurally one body with a limiter arm 99 and a limiter positioning guide 100 . Therefore, when the stroke length 106 is adjusted by moving the limiter positioning guide 100 , the optical switch 92 is positioned in new location. Once the stroke length is adjusted, the new position is locked up by limiter clamp 98 . The plunger activation signal is generated when the light path of the optical switch 92 is blocked by the optical switch activator 94 , which can be a protrusion that can move into the path of a light beam, thereby actuating optical switch 92 . The optical switch activator can be set so it blocks the light path at the moment when the manual pushing plate 101 is touched to the limiter arm 99 . Once the appropriate standoff distance of the optical switch activator 94 is found, the position is locked up by the optical switch activator clamp 103 .
Signals from the optical switch 92 permit signal processing programs to accurately align the signal profiles in the time domain and measure the stress relaxation time. Such measurements are particularly beneficial to measure the viscous property of internal tissues, such as vaginal tissue layers. Any optical switch sensor known in the art and capable of providing digital output can be utilized. In one embodiment, a model OPB-855 phototransistor type optical switch from Optek Technologies Inc (Carrollton, Tex.) was used. The principle of the optical switch operation for this specific embodiment is shown at FIG. 4 . When the plunger drive shaft 93 pushes the syringe plunger, the optical switch activator 94 travels through the opening slot of the optical switch 92 . Once the optical switch activator 94 moves into the slot it blocks the light passage from the phototransistor 120 to the photodiode 121 . This light blockage causes the signal output of the photodiode 121 to change. This change in signal level is detected by the signal processing circuitry, 122 , and generates the digital signal 123 . Digital signal 123 is treated as a syringe plunger activation signal 142 which is shown at FIG. 11A , with other stress signals.
The fluid used to actuate a strain transducer can be gas or liquid. In one embodiment liquid is used to inflate an inflatable balloon 32 . In one embodiment the liquid can be water or saline solution. As a technical matter, the choice of gas or liquid is important with respect to the imaging modality (as discussed below). In the case of ultrasound imaging, a liquid is preferred because of ultrasound attenuation by a gas phase medium. With CT imaging or MRI imaging, there is less signal attenuation in a gaseous medium.
The operation of the device as discussed so far can be explained as follows. In one embodiment balloon 32 is made with a highly elastic latex material. The balloon has non-zero modulus, therefore, when the balloon is forced to expand by fluid volume controller 50 , thereby increasing balloon strain, the balloon experiences stress increase and as a result, the internal pressure of the entire tubing line shown at FIG. 2B increases. This pressure increase is detected by the pressure transducer 40 . This measurement is the in vitro balloon pressure.
Once the balloon is situated in an internal body cavity, such as the vagina 14 , tissue loading can cause the balloon to experience a net volume reduction, ΔV, which in turn increases the internal pressure of the entire tubing line shown in FIG. 2B . All the components of the apparatus except the inserted balloon are relatively inelastic; therefore, once the balloon experiences very small compressive force by tissue loading, the balloon deforms. As a result, the volume reduction, even a slight volume reduction (and isothermal) results in a pressure increase within the tubing line. This pressure change is detected by the pressure transducer 40 .
In a similar manner, when the syringe plunger 54 pushes a certain volume of liquid from syringe housing 52 , the balloon 32 absorbs this syringe volume reduction and increases its size. As the balloon 32 increases its size, it applies strain energy on the vaginal tissue layers. If the internal body tissue is highly elastic, which is the case for vaginal tissue, most of the strain energy is absorbed by the tissue and the balloon can expand to the size of the in-vitro (i.e., no tissue existing) condition. However, if the tissue is highly inelastic, the tissue is not deformed much and most of the strain energy is absorbed by the balloon, and as a result, it increases the internal pressure significantly because volume reduction by the syringe plunger is not compensated unless the balloon absorbs that strain energy. Therefore, for the same syringe volume reduction, relatively inelastic tissue causes reduced rate of volume (or diameter) increase of the inserted balloon; therefore, net volume change of the entire tubing line is large and as a result, a higher pressure is experienced.
Imaging device 60 can be any of known medical grade imager to image a living body, including CT scanner, MRI devices and ultrasound devices. In one embodiment, such as the one shown in FIG. 1A , the imaging device 60 comprises an externally-disposed probe, such as an ultrasound probe 62 of a Voluson 730® ultrasound imager from Medison-GE Healthcare (Waukesha, Wis.). Imaging means 60 permits visual or digital imaging of tissues and organs, and detects changes in position that can be correlated to the strain of tissues and organs. Ultrasound imaging can operate in M (motion)-mode for imaging or B (brightness)-mode for regular anatomical imaging of lower pelvic floor.
Device 10 works in principle by correlating pressure changes and rates of change of pressure within the tissue strain device 30 (i.e., a balloon) to the strain and rates of strain changes of tissues and/or organs. Pressure can be measured directly via pressure transducer 40 while imaging device 60 can measure tissue strain by measuring changes in position or changes in dimensions of tissues or organs. The pressure signal is evaluated to estimate the loading stress applied on a defined in-vivo area, thereby later enabling the calculation of material parameters such as modulus of tissues and/or organs. Such a device is useful, for example, for determining tissue properties required for modeling the insertion, expansion, and pressure application of a device penetrating the vaginal orifice, such as a tampon inserted into a vagina.
Method of Use
In general, the method of use includes inserting the tissue strain device, 30 , into a body cavity of interest, directing the imaging means to detect dimensional changes at the area of interest, changing the volume of the tissue strain device by forcing fluid from the fluid volume controller and into the tissue strain device, detecting and measuring changes in pressure, detecting and measuring changes in position or dimension of the tissue or organ of interest, and correlating the measured parameters to determine biomechanical properties of internal tissues and/or organs.
Prior to inserting an inflatable probe, i.e., inflatable balloon 32 , into the body cavity of interest, the in-vitro modulus of inflatable probe can be measured. By determining the in-vitro modulus of inflatable probe and measuring the pressure required to inflate the probe in-vitro, the net modulus and net pressure caused by the in-vivo volume expansion of the inflatable probe can be more accurately calculated by subtracting the in-vitro modulus and pressure from the in-vivo modulus and pressure.
In one embodiment latex balloon 32 has a relaxed, un-inflated volume of about 0 to about 3 ml. Latex balloon 32 can be slightly inflated with water or saline solution to about 5 to 10 ml prior to insertion into the desired body cavity. For example, balloon 32 can be slightly pressurized to give some stability to the balloon and assist in insertion into the vagina through the vaginal opening. Once inserted into the desired body cavity, e.g., the vagina, imaging means can be utilized to image the portion of the body in which the inflatable probe is to be expanded to induce strain to nearby tissues and organs.
The location of the inflatable probe can be verified by utilizing an ultrasound imaging means, used with ultrasound B mode. In one embodiment, the ultrasound probe 62 can be a Voluson 730® Abdominal Transducer, Model RAB4-8, operated at about 560 micron resolution. In addition to verifying the location of inflatable probe, e.g., inflatable balloon 32 , the ultrasound image can detect and record the corresponding position of tissue boundaries. Thus, for example, in addition to imaging the inflatable balloon 32 and a portion of the vagina, ultrasound imager images the bladder wall, a portion of the uterus, cervix, and some of the rectovaginal tissue layers.
Syringe plunger 54 of fluid volume controller 50 can be actuated so as to force fluid, such as water or saline solution, through tubing sections 42 and 43 and into inflatable balloon 32 . As inflatable balloon 32 contacts and deforms adjacent vaginal tissue layers, any resulting increase in pressure is measured and recorded by pressure transducer 40 and any accompanying devices to translate the pressure into computer-readable data. Such accompanying devices can include signal conditioning amplifier 46 , and data acquisition module 48 .
As inflatable balloon 32 contacts and deforms adjacent tissue layers, imaging means can detect and record deflection, deformation, or other changes in tissues or organs. In one embodiment, ultrasound imaging device can be used in M-mode during the inflation or deflation process of an inflatable balloon 32 . While permitting higher quality of tissue motion profile, the M-mode only works at certain scanning paths, i.e., one-dimensional paths for a one-dimensional scanning profile. In another embodiment, B-mode based strain analysis can be used. Most ultrasound imagers have video mode (Cine mode) of image recording, therefore, analysis of time dependent tissue deformation is possible.
Imaging means can capture information about tissue strain and/or tissue strain rate. Net tissue displacement can be determined as well as net displacement or deformation of tissue boundaries and adjacent organs. In particular, B-mode imaging can be used to determine net tissue deformation and M-mode imaging can be used to calculate dynamic tissue strain. Further, using Cine operation of B-mode in the Voluson 730® ultrasound imager, it is possible to acquire time dependent tissue deflection profiles with proper image analysis. This method can be useful for the measurement of creep phenomena of vaginal tissue layer, for example.
As shown in FIG. 5 , tissue strain and deformation profiles can be obtained by use of both B- and M-mode ultrasound images. Voluson 730® ultrasound imager can provide both B- and M-mode images on the same screen to aid in understanding where to monitor the tissue motion profile. FIG. 5A shows a B-mode axial view and FIG. 5C shows a B-mode sagittal view of a vagina and surrounding tissues. FIGS. 5B and 5D are the M-mode images along the scanning paths shown at FIGS. 5A and 5C , respectively. The M-mode is an ultrasound representation for time and tissue motion profile. The M-mode image of FIG. 5B , for example, shows periodic tissue strain profiles along the scanning path shown at FIG. 5A . The horizontal axis in the images of FIGS. 5B and 5D represents the temporal scale, while the vertical axis represents the geometric scale along the scanning lines shown at FIGS. 5A and 5C .
Bladder 66 is clearly visible at both B- and M-mode images of FIG. 5 . The vesicovaginal and rectovaginal tissue layers are shown at 67 and 68 , respectively. The image also shows the in-vivo tissue strain device 30 , in this case, a balloon 32 . The rate of tissue deformation, axial strain, can be measured from the images shown at FIGS. 5B and 5D .
The images shown in FIGS. 5C and 5D show “quasi-static” tissue strain profiles. The bladder, 66 , is a non-echo area (dark) because urine is an acoustically favorable medium. Tissue layers are shown, from which quantitative measurement of deformation of tissue layers can be made. In FIG. 5D , layers 150 , 151 and 152 show, respectively, the bladder tissue layer, anterior vaginal tissue layer (vesicovaginal), and posterior vaginal tissue layer (rectovaginal). This particular M-mode image further shows these tissue layers as they move from a strained phase ( 150 , 151 , 152 ) to relaxed phase ( 153 , 154 , 155 ). Movement can be quantified both in distance and rate by reference to the image output of the imaging means, such at that represented in FIG. 5 .
The value of visualizing tissue boundary deflection with both B- and M-modes is to permit strain analysis and determine tissue strain, modulus, and other biomechanical properties. B-mode only can be used, but the time to get data is increased because two image sets are required to calculate each increment of strain, for example, the first unstressed position image and the second stressed position images. M-mode permits measurements and data collection as a function of time. Many ultrasound imagers have the capability to show the B- and M-mode at the same screen so the operator understands the scanning path for the M-mode. The dotted lines shown at images of FIGS. 5 A and 5 C indicate the scanning path of the corresponding M-mode images. The vertical position on the M-mode image has a geometric correspondence to the anatomical position along the scanning path of the B-mode image. As shown in both of these images, the B-mode ultrasound is directed through inflatable balloon 32 and other tissues of interest adjacent to the balloon in vivo. As the balloon 32 is inflated and deflated by means of operation of the fluid volume controller 50 , the M-mode data visualization can show the relative dimensional changes in tissue layers. Using the M-mode visualization of dimensional changes strain can be calculated for imaged tissues and organs.
One method of determining strain levels can be understood with reference to FIG. 5B in which three different connective tissue layers are measured over time to obtain normal strain during periodic inflation and dilation of an inflatable balloon 32 . The vesicovaginal tissue layer is identified as layer 67 and is between the vagina (in which inflatable balloon 32 is lodged), and the bladder 66 . The rectovaginal tissue layer 68 is between the vagina and the rectum (not identified). Identification of these tissues is achieved by comparing the geometric location of each layer at the B-mode image, in this case as shown in FIG. 5A . The periodic trace 175 superimposed over balloon 32 in the M-mode image corresponds to the balloon internal pressure profile.
As shown in FIG. 5B , when the internal pressure of inflatable balloon 32 increases, the thickness of the adjacent tissue layers decreases. The actual dimensional change of tissue thickness can be obtained by scaling the electronic ruler available from the ultrasound imager and shown as overlapped in the ultrasound image to the number of pixels corresponding to the ruler setting. After calibration, the spatial calibration factor is expressed in units of mm/pixel. Once the vaginal tissue wall boundaries are identified, an image processing program made with MatLab (Mathworks Inc., Natick, Mass.) can acquire the numbers of pixels in a deformation and can calculate the deformation depth in mm. Once deformation values for vesicovaginal and rectovaginal tissue layers are obtained, the local axial strain can be calculated from the formula of equation (1):
ɛ z = ( L DB - L IB ) L DB ( 1 )
where the ε z is the axial local strain of the vaginal tissue layers; L DB and L IB are the tissue layer thickness profiles when the balloon is deflated and inflated states. In FIG. 5B , the strain of the vesicovaginal tissue layer is calculated at one location to be 0.22 and the strain of the rectovaginal tissue is calculated as 0.78. It has been found that strain can vary at different parts of the same organ. For example, strain of tissues at different portions of the vagina can vary as shown in FIG. 12 .
Another method for determining strain is illustrated with respect to FIGS. 5C and 5D . As shown in FIG. 5D , the rectangular-shaped strain boxes generated by a MatLab program can be superimposed over tissue layers. While the size of the box can be somewhat arbitrary, one skilled in the art will see that the height of the box should correlate to the thickness of the layer to be measured. FIG. 5D shows the bladder wall tissue before strain 150 and after strain 153 ; the vesicovaginal tissue before strain 151 and after strain 154 ; and, the rectovaginal tissue layer before strain 152 and after strain 155 . By calculating the number of pixels along line 69 in FIG. 5C for each respective layer of tissue, a pixel conversion ratio (mm/pixel) can be used to compare the pixel resolution with the number of pixels in the vertical axis of the various strain boxes in FIG. 5D . The pixel-to-mm conversion permits the dimensional changes in the tissue layers to be reported in mm. Strain can be calculated based on either pixels or mm dimensions. In one embodiment of the method, the size of each pixel is very small (usually less than 33 microns in case of Voluson 730 ultrasound imager for abdominal imaging) compared to the tissue thickness dimension (mm order). Therefore, the tissue dimension measurement error due to the pixel quantization is believed to be negligible. For the tissues imaged in FIG. 5D , the strain profiles are shown in Table 1.
Tissue deformation and axial strain analysis can be made by computer analysis. In one embodiment, a MatLab® program to analyze the tissue properties of vaginal tissue was run according to the flowchart shown in FIG. 6 . The raw image files of ultrasound B and M modes are read into the MatLab® platform; appropriate image file format conversion is necessary for this step such as from DICOM to JPEG or BMP files. With numbers of pixels across the axial depth and lateral width dimension of ultrasound image as shown at FIG. 5 , calibration is done for the calculation of mm per pixel. Once this calibration is done, the MatLab® program can calculate the actual dimension from the images of ultrasound or any other imaging modalities. The next step is to take the major points of interest from the B mode image; in case of images shown at FIG. 5 , we can see the lower pelvic floor organs. In one application of image analysis, we use the bladder and the vagina as major organs for the strain analysis, for example, as shown in FIG. 5B , the anterior bladder wall 171 , posterior bladder wall, 172 , superior vaginal wall, 173 , and inferior vaginal wall, 174 . These anatomical ‘fiducial” points are important to further classify tissue layers such as vesicovaginal and rectovaginal tissues. The MatLab® program can recognize these points on the B mode image and can find the matching locations within the M mode for the strain analysis and recognition of other tissue layers. After these fiducial points are determined, the program allows a user to choose the region of interest (ROI) for the strain measurement. These ROIs should include tissue layers stressed and relaxed (mildly stressed) by the inserted tissue strain device, 30 , in this case, a balloon 32 . In FIG. 5D , regions 150 , 151 , 152 are stressed inferior bladder wall layer, superior vaginal tissue layer, and inferior vaginal tissue layer, respectively. Similarly, the regions 153 , 154 , 155 correspond to the relaxed tissue layers. The MatLab® program recognizes those ROIs and calculates the strain of each layers with equation (1); in this case three layers of bladder inferior, vaginal superior and inferior walls. In steps 6 and 7 in FIG. 6 , the pixel conversion factor obtained in step 2 is used to obtain the metric unit (e.g., millimeter) based tissue layer thickness. As a final step, the program can save the input dialogue parameters such as file name, directory path, etc., and print the calculated strain values on the default output device, e.g., computer monitor screen and/or spreadsheet format output file.
Another embodiment of strain analysis could be based on a tissue deflection measurement. For example, a strain analysis program could be designed to track tissue deflection by insertion of a tissue strain device. In one embodiment the tissue strain device could be a balloon 32 or it could be a tampon-like product if measuring vagina tissues. Tissue deflection information is useful not only in understanding the mechanical properties of tissues, but also for validating the interaction between in vivo products and tissue layers, as well as virtual tissue models.
FIG. 7 shows one example of image analysis for tissue deflection measurement. Specifically, an ultrasound image shows how an object, such as an inserted balloon or tampon applicator can deflect vaginal tissue layers. In FIG. 7A , a tampon applicator tip is shown inserted into a vagina. The surrounding organs like the bladder posterior wall boundary 153 , the superior vaginal tissue layer 154 , and rectovaginal tissue layer 155 are visible. A MatLab® program following the flowchart in FIG. 8 can provide tissue deflection analysis for the data shown at FIG. 7 . The MatLab® program can generate the tissue boundary tracking lines 153 , 154 , and 155 of FIG. 7 along the three major layers, and the reference deflection lines 150 for the desired number of measurement positions; in the cases shown in FIG. 7 , eight positions on the mid-sagittal plane. The program acquires multiple frames of ultrasound cine mode images and checks the shift in the cross points of tissue tracking lines 153 , 154 , 155 and the reference deflection lines 150 . The tissue tracking lines are built by the program along the boundaries of major organs; those organ boundaries are also changed as an applicator 156 and a balloon 165 are inserted into a vagina. Those reference deflection lines 150 work as local y axis of tissue image, while the reference plane line 166 works as a local x axis. Therefore, the cross-points between the tissue tracking lines and the reference deflection lines indicate the tissue layer deflection at a given position. Finally, the distances from the reference plane line 166 to those cross-points are the tissue deflection data that are saved by the MatLab® program. As the object, such as tampon applicator, is inserted, it is expected that the distance between the superior and the inferior vaginal walls 154 and 155 increases. The cine mode is useful to check the tissue boundary deflection during the insertion process of a balloon or an applicator.
In the image shown in FIG. 7 , a part of uterus 151 is also used to determine the onset of reference plane line 166 ; except the case to measure the tissue deflection under cervix, the reference plane line 166 begins from the near cervix through the near introitus. As shown in FIGS. 7A and 7B , the orientation of an applicator body 156 and balloon tubing 166 could be utilized to find the ending limit of reference plane line 166 .
Once the MatLab® program recognizes the starting and ending frames of insertion process (Step 3 in FIG. 8 ), the program calibrates spatial coordinates along the x and y axis of an image; this calibration process can be as in Step 2 of FIG. 7 , so the process generates the calibration factor of mm/pixel. In Step 4 , the program recognizes the major fiducial points such as a center of a balloon or an applicator tip, and reference plane line. The program can now builds the evenly-spaced tissue tracking lines 153 , 154 , 155 over the length of the reference plane line 166 . In Step 6 , tissue tracking is done and the program recognizes the cross points of the reference deflection lines 150 and tissue tracking lines 153 , 154 , 155 . The program can calculate the normal strain values of tissue layers and saves those results in an output data file.
While strain values are calculated from ultrasound images, pressure values are obtained and recorded by pressure transducer 40 as shown in FIG. 1A and related data collection devices such as signal conditioning amplifier 46 and data acquisition module 48 . All of the data, including dimensional data from the ultrasound probe 62 can be analyzed by computer 70 to calculate elastic modulus for each tissue or portion of a tissue in which strain is calculated. Pressure level applied on the in vivo inflatable device 30 , or balloon 32 can be obtained through the calibration and linear regression analysis.
The pressure sensors can be calibrated by the manufacturer and a calibration certificate is usually available with the product. However, because tissue loading pressure can be very low (e.g., less than 1 psi) for soft tissues such as vaginal tissues, it is suggested to calibrate the pressure transducer prior to making measurements with the apparatus of this invention. One method of calibrating the pressure transducer is illustrated in FIG. 9A . The illustrated method of calibration can be modified according to the types of transducer design and sensor. In one embodiment, the pressure transducer can be a strain-gauge type pressure sensor with electrical insulation between the pressure sensing element and transducer face like the case of physiological pressure transducer. In this type, a liquid column 130 (preferably the same liquid as the one used in the balloon and tissue strain device shown at FIG. 2 ) stands in vertical section of a U-shaped tube 132 . The vertical section of the U-shaped tube has a scale to indicate the height of water column and the U-shaped connecting tube transfers the pressure due to the water column height to the pressure transducer under calibration 131 . The signal acquisition and processing instruments can include a signal amplifier 133 , a power module 134 , a safety and isolation module 135 , a signal isolator 136 , and data acquisition module 138 . These instruments can be identical to the ones used for the in-vivo measurement as described with respect to the apparatus shown in FIG. 1A . Additional data collecting instruments like a digital multimeter 137 (for example, a model 34401A, from Agilient Technologies (Palo Alto, Calif.)) can be used.
The pressure applied on the pressure transducer 131 under calibration is the hydro-head pressure of liquid column 130 , which is given as ρgh when the ρ is the density of liquid in the column, g is the gravitational acceleration and h is the height water column. Therefore by adjusting the height of liquid column, the calibration pressure can be changed. Care should be taken to give enough time for each measurement if the transducer has a thermal constant. This calibration procedure can provide an accurate and highly linear calibration as illustrated by the graph shown at FIG. 9B . If the thermal constant effect of a pressure transducer is negligible, a more accurate and fast calibration method can be used, such as that of the calibration unit from Fluke (Everett, Wash.); model 744, Documenting Process Calibration, model 700PD7 Pressure Module, and model 700 PTP Pneumatic Test Pump.
Once calibration of the pressure transducer is achieved, the system 10 can be used to measure in vitro and in vivo pressure. As described above, the net loading pressure applied on a tissue is obtained by subtracting the in vitro balloon pressure from the in vivo total pressure. A flow chart for a MatLab®-based program to handle this stress signal processing is shown at FIG. 10 . The program first imports the raw data file of tissue loading pressure measured in vivo. In Step 3 in FIG. 10 , the program separates channels of in-vivo and in-vitro pressure transducer signals and optical switch ( 92 of FIG. 3A ) generates a signal indicating the moment when the manual pushing plate 101 is stopped by the limiter arm 99 . This signal means that the full injection of liquid volume into a balloon is done. In the next step, the balloon modulus effect on the pressure signal is compensated; the in vivo pressure signal is subtracted from the in vitro pressure signal, so the net change of pressure signal by the tissue loading is determined. The pressure signal is still a raw data of electrical signal from the transducer, therefore, in Step 4 , the program converts the voltage signal into engineering unit based data such as kilo Pascal, kPa [1 Pascal=N/m 2 , 1 kPa=10 3 Pa. The calibration factors found in the pressure transducer calibration as discussed with reference to FIG. 9 are used to convert the voltage signal into the kilo Pascal data. The signal could be still noisy; the signal frequency is in general low considering the viscoelastic property of vaginal tissue; therefore, a low pass filter of unity gain at pass band is applied on the signal. Typical cutoff frequency is as low as 100 Hz, however, depending on the tissue of interest and estimated modulus, this cutoff frequency can be chosen differently. The outcomes of stress signal processing include (1) quasi-static or static loading pressure applied on the tissue layers, and (2) stress relaxation process monitored by the decreasing loading pressure. In the steps 5 and 6 , those data become available; the detail of this method is described below in conjunction with FIG. 11 .
The noise-filtered stress signal is interpolated to the equation of stress relaxation-exponential decay using parameters such as initial stress, final stress, and decay constant, and these parameters can be used to understand the viscous property of a tissue. The concept of signal processing to calculate those parameters is shown graphically in FIG. 11A ; it corresponds to the use of the apparatus as shown in FIGS. 2 and 3 . When the syringe pushing handle 101 is pushed to a preset position (volume reduction of syringe), optical switch 92 (if used) detects the moment when the balloon in-vivo is fully expanded and generates a time-stamping signal 142 . The pressure level within the in vivo balloon reaches its highest level just before the syringe pushing handle is pushed to the preset position, and the pressure rapidly drops to its initial level 141 . This is the moment when the syringe pushing handle is completely stopped, and the transient dynamic pressure starts declining; this transitional pressure effect is mainly caused by turbulent flow of liquid inside tubing line. This transient phenomenon is an artifact of the signal linked to stress relaxation. Therefore, in the signal processing, the initial pressure level and the onset of real stress relaxation are connected linearly 143 , as shown graphically in FIG. 11B . The transition between the two pressure levels can be non-linearly made, but the difference in the viscous property related parameters between the linear and non-linear connection was small for the highly elastic in-vivo tissue.
Once the two data points are connected, a three-parameter exponential regression of the format, A+B e −Ct , can be applied to the processed signal profile. The resulting profile 144 following the equation of relaxation is given at FIG. 11B . Once the tissue loading stress is obtained, further material properties can be available; shear and normal modulus. Table 1 below shows the some of the parameters available from this analysis with respect to a subject vaginal tissue. The strain data shown in Table 1 is used with the stress data analyzed for the modulus data. In Table 1, the measurement of strain by ultrasound images and stress measurement by an in-vivo balloon have been done at each of the four different locations within the middle portion of a vaginal path.
TABLE 1
Viscoelastic parameters available from the strain and stress measurement.
Locations within Middle of Vaginal Path
1
2
3
4
Parameter
Vesico
Recto
Vesico
Recto
Vesico
Recto
Vesico
Recto
Poisson
0.49
0.49
0.49
0.49
0.49
0.49
0.49
0.49
Ratio, τ
Normal
0.5
0.435
0.433
0.375
0.533
0.308
0.141
0.256
Strain, ε
Normal
7.650
7.650
7.212
7.212
7.440
7.440
8.995
8.995
Short
Term
Stress
[kPa], σ o
Normal
7.065
7.065
6.972
6.972
7.223
7.223
8.192
8.192
Long Term
Stress
[kPa], σ ∞
Shear
0.059
0.059
0.241
0.241
0.2
0.2
0.058
0.058
Decay
Constant
[s −1 ], β
Relaxation
16.949
16.949
4.149
4.149
5.000
5.000
17.241
17.241
Time [s],
τ ε
Short
5.1342
5.9014
5.5892
6.4537
4.6841
8.1060
21.4075
11.7908
Term
Shear
Modulus
[kPa], G o
Long Term
4.7416
5.4501
5.4032
6.2389
4.5475
7.8696
19.4964
10.7383
Shear
Modulus
[kPa], G ∞
Elastic
235.50
270.69
268.36
309.87
225.86
390.85
968.32
533.33
Bulk
Modulus*
[kPa], K
By measuring parameters such as normal strain, σ and stress, ε, we can obtain the secondary parameters, which are important to understand the biomechanical behavior of in vivo tissues. For example, shear modulus, G, with Poisson ratio, ν, is calculated from the equation of
G = E 2 ( 1 + v ) = σ / ɛ 2 ( 1 + v ) ( 2 )
where E is Young's modulus. The elastic bulk modulus, K, is obtained by
K = E 3 ( 1 - 2 v ) ( 3 )
Viscoelastic properties can be derived from the stress relaxation process, which is described as an instantaneous shear modulus,
G ( t ) = σ ( t ) ɛ · 2 ( 1 + v ) ( 4 )
where the time-dependent stress relaxation process is σ(t) for the given constant strain, ε. This shear modulus is described by the following general format of equation,
G ( t )= G ∞ +( G o −G ∞ ) e −βt (5)
where G O is the short term shear modulus, G ∞ is the long term shear modulus, and β is the shear decay constant.
FIG. 12 shows one typical graphical result showing the non-uniform distribution of normal strain in a human tissue, in this case, vaginal tissue layers. The graph shows the trend of declining strain of both vesicovaginal and rectovaginal tissue layers at the cervix and near introitus. The rectovaginal tissue layer tends to deform more than the vesicovaginal tissue layers, which could indicate the relative effects of surrounding organs-bladder and rectum. This graph suggests that the strain distribution of an in-vivo tissue layer can be locally determined.
FIG. 13 shows viscosity related properties of an in vivo tissue including initial and final stress levels that the tissue experiences. As the graph shows, the mid portion of a vagina can experience a low level of short and long term stress to a given constant strain, and as the measuring position moves away from the mid portion, the stress tends to increase, which implicates different compositions of vaginal tissue layer and as a result, different biomechanical properties of tissue at different locations of vagina.
Method to Determine Biomechanical Properties of Internal Tissues Using Inverse Finite Element Analysis
The device of the present invention can be used to determine the biomechanical properties of internal tissues by a methodology referred to herein as “inverse finite element analysis” (hereinafter referred as “inverse FEA”). Inverse FEA is a numerical approach where unknown input parameters are determined such that simulated experiment results with a finite element analysis method (hereinafter referred as “FEA”) match actual experiment results.
The first step in the Inverse FEA method is to construct a numerical model for the expandable tissue strain device 30 using measured in-vitro properties of the expandable tissue strain device 30 . Next, a numerical model for the body 12 can be constructed which includes tissues and/or organs, and the body cavity of interest characterized with certain numerical equations (i.e., material models) comprising arbitrary parameters in the equations, and certain boundary conditions. The third step involves numerically simulating the controlled volume change of the expandable tissue strain device 30 , which is inserted into the body cavity to a certain point and obtaining the simulation results including the change in pressure of the expandable tissue strain device 30 and the change in position or dimension of the tissues or organs of interest. Step four involves comparing the simulated results from Step 3 with the equivalent measured in-vivo results from the use of device 10 of the present invention, i.e., the change in pressure of the expandable tissue strain device 30 measured by the external pressure transducer 40 , and the change in position or dimension of the tissues or organs of interest measured by the external imaging device 60 .
If Step 4 of the Inverse FEA method does not result in agreement between the simulated results and the equivalent measured in-vivo results, return to Step 2 , change the parameters in the material models, and then iterate Step 3 and 4 . This process can continue until the simulated results agree with the equivalent measured in-vivo results with desired accuracy. Once the agreement is achieved, the biomechanical properties of the tissues or organs of interest are finally determined in the form of the material models comprising the optimized parameters.
Any of known software, algorithms, numerical codes, or numerical solvers can be use for the inverse FEA of the present invention. Such tools may give explicit solutions or implicit solutions. Preferably, such tools are capable of solving the equations of motion using an explicit time integration technique that incorporates lumped mass matrices and vectorization/parallelization algorithms. This type of numerical solver is available as any commercial explicit FEA software package such as ABAQUS/Explicit® from Abaqus, Inc. of Providence, R.I., LS-DYNA® from Livermore Software Technology Corp. of Livermore, Calif., and ANSYS LS-DYNA® from Ansys Inc. of Cannonsburg, Pa. Unless otherwise mentioned, LS-DYNA® is used as the numerical code for the inverse FEA of the present invention.
Constructing a numerical model for the expandable tissue strain device 30 requires characterization of any in-vitro (i.e., measured externally to the body) mechanical behavior of the expandable tissue strain device 30 . In one embodiment, characterization can be achieved by measuring the pressure change read by the pressure transducer 40 , to which the expandable tissue strain device 30 is connected via the tubing 42 , in accordance with the controlled volume change of the expandable tissue strain device 30 by the fluid volume controller 50 , being placed in free air (e.g., being held by hand at the joint between the expandable tissue strain device 30 and the tubing 42 in the exterior to the body).
Line 211 in the graph of FIG. 14 (labeled “Measured Average) illustrates a relationship between the pressure change measured by the pressure transducer 40 and the volume change of the expandable tissue strain device 30 controlled as the fluid injection volume from the fluid volume controller 50 , for one embodiment where the expandable tissue strain device 30 is an inflatable latex balloon as described above. The numerical model for the expandable tissue strain device 30 may comprise any type of finite elements defined by any type of element formulations. In one embodiment, where the expandable tissue strain device 30 is the inflatable latex balloon hereinabove, shell elements (set with LS-DYNA syntax: *ELEMENT_SHELL) with the Belytscho-Tsay formulation (set with LS-DYNA syntax: *SECTION_SHELL including a variable setting: ELFORM=2) may be used. The numerical model for the expandable tissue strain device 30 may also comprise any type of material models. In one embodiment, where the expandable tissue strain device 30 is the inflatable latex balloon hereinabove, the Mooney-Rivlin hyperelastic rubber model (set with LS-DYNA syntax: *MAT_MOONEY-RIVLIN_RUBBER) may be used.
Line 212 in the graph of FIG. 14 (labeled “FEM Modeling”) illustrates a simulated relationship between the pressure change and the volume change of the expandable tissue strain device 30 for one embodiment, where the expandable tissue strain device 30 is the inflatable latex balloon described above, showing agreement with the measured relationship between the pressure change and the volume change of the expandable tissue strain device 30 .
Construction of a numerical model for the body 12 which includes the tissues or organs, and the body cavity of interest may be composed of imaging of the anatomy of the part of the body including the tissues or organs and the body cavity of interest, followed by numerical reconstruction of the part of the body, segmentation for the tissues or organs, rendering of the reconstructed/segmented part of the body to finite elements (i.e., “meshing”), and then, assignment of certain material models comprising arbitrary parameters to the segmented parts for the tissues or organs of interest and setting of certain boundary conditions. Methods for such imaging are included in co-pending, commonly assigned US 2005/0264561 and US 2005/0264572 to Anast et al., and US 2005/0264562 and U.S. Pat. No. 7,634,394 to Macura et al.
The imaging of the anatomy of the part of the body including the tissues or organs and the body cavity of interest may be achieved by any of known imaging devices for imaging a living body including CT scan devices, MRI devices, ultrasound devices, X-ray devices, and the like. In one embodiment, the imaging device is a MRI device, for example, available from GE Healthcare of Waukesha, Wis., under the trade name of Genesis Sigma 1.5 T Echo Speed LX. The image taken with the imaging device may comprise a set of images corresponding to a series of cross sections of the part of the body along one or more certain axes, which may be rendered to provide three-dimensional definition of the part of the body by means known in the art.
Numerical reconstruction of the part of the body including the tissues or organs and the body cavity of interest may be achieved by any commercial computer aided design (hereinafter referred as “CAD”) software package such as I-DEAS® MasterSeries from UGS Corp. of Plano, Tex., SolidWorks® from SolidWorks Corp. of Concord, Mass., MIMICS® from Materialise Corp. of Ann Arbor, Mich., Geomagic Studio® from the Raindrop Geomagic, Inc. of Research Triangle Park, N.C., Scan IP/FE® from Simpleware Ltd., of United Kingdom, and 3D-DOCTOR® from Able Software Corp. of Lexington, Mass. The numerical reconstruction of the part of the body including the tissues or organs and the body cavity of interest may also be done as part of the MRI scanning and data processing.
The reconstructed part of the body may have a one-dimensional, two-dimensional, or three-dimensional shape. It also may include certain simplifications for efficient computing in the following procedures of the inverse FEA. It may include any added line, area, or volume, which does not exist in the actual image of the body or the actual body. Its boundary may be set to be a boundary of the actual image of the body or the actual body or may be set arbitrarily according to positions, displacements and deformations of the tissues or organs of interest, and for efficient computing in the following procedures of the inverse FEA.
The numerical reconstruction of the part of the body may be alternatively achieved by drawing using certain dimensions taken from the image of the part of the body from the imaging device or the reconstructed part of the body by the CAE package. In this approach, the reconstructed part of the body including the tissues or organs and the body cavity of interest may comprise any regular or irregular shapes of lines, areas, or volumes and the dimensions taken from the image of the part of the body from the imaging device or the reconstructed part of the body by the CAE package are assigned to define the shapes. For efficient computing in the following procedures of the inverse FEA, the reconstructed part of the body including the tissues or organs and the body cavity of interest may also comprise approximation in shapes using simple equations, for example, an ellipse or cylinder, etc.
In one embodiment, where the imaging device is a MRI device and the CAE package is MIMICS® from Materialise Corp. of Ann Arbor, Mich., a set of cross-sectional images of the part of the body from the MRI device may be written in the DICOM format. Such DICOM files comprising the set of cross-sectional images of the part of the body can be exported to MIMICS® and rendered to provide numerical reconstruction of the anatomy of the part of the body.
Segmentation for the tissues or organs in the reconstructed part of the body and meshing may be conducted sequentially or simultaneously using any commercial software package designed for either or both of them. The meshing may follow the segmentation or vice versa. The software package useful may include any of commercial software packages for CAD such as described above, and any of commercial software packages for pre-processing of FEA such as Hypermesh® from Altair Engineering Inc. of Troy, Mich., I-DEAS® from UGS Corp. of Plano, Tex., ABAQUS® from Abaqus Inc. of Providence, R.I., LS-PREPOST® from Livermore Software Technology Corp. of Livermore, Calif., and ANSYS LS-DYNA® from Ansys Inc. of Cannonsburg, Pa. For the meshing, any type of elements can be selected such as tetrahedral and hexahedral solid elements, triangular and quadrilateral shell elements, beam and discrete line elements and concentrated mass elements. Multiple formulations of the selected elements are available to simulate the behavior desired. In one embodiment, where the software package used is MIMICS®, the segmentation for the tissue or organs and the meshing can be done with the same software package as the numerical reconstruction of the part of the body including the tissues or organs and the body cavity of interest, in such a way that instructed in the software package. In another embodiment, the numerical reconstruction of the part of the body including the tissues or organs and the body cavity of interest is done by any CAD software package such as MIMICS® and the reconstructed part of the body is exported to any software package for pre-processing of FEA for following segmentation and meshing such as Hypermesh®.
For the meshing, any type of finite elements defined by any type of element formulations can be selected. The segments for the tissues or organs of interest may have the same elements or different elements. In one embodiment, where the reconstructed part of the body includes the vaginal cavity defined as a cavity between the vesico vaginal tissue and the recto vaginal tissue, and segmented parts corresponding to the vesico vaginal tissue, the recto vaginal tissue, the bladder, the urethra, the uterus including the cervix, the rectum, and the pelvic bone, the vesico vaginal tissue, the recto vaginal tissue, the uterus including the cervix, and the pelvic bone may comprise solid elements (set with a LS-DYNA syntax: *ELEMENT_SOLID), and the bladder, the urethra, and the rectum may comprise shell elements (set with a LS-DYNA syntax: *ELEMENT_SHELL).
Once the reconstructed part of the body including the tissues or organs and the body cavity of interest is rendered to be a model comprising finite elements, certain material models comprising arbitrary parameters are set for the segmented parts for the tissues or organs of interest and certain boundary conditions are provided. Setting material models comprising arbitrary parameters for the segmented parts for the tissues or organs of interest, and setting certain boundary conditions can be achieved by, any commercial software packages for pre-processing for FEA, such as Hypermesh® from Altair Engineering Inc. of Troy, Mich., I-DEAS® from UGS Corp. of Plano, Tex., ABAQUS® from Abaqus Inc. of Providence, R.I., LS-PREPOST® from Livermore Software Technology Corp. of Livermore, Calif., and ANSYS LS-DYNA® from Ansys Inc. of Cannonsburg, Pa., or by manually editing the input files for the model of the part of the body including the tissues or organs and the body cavity of interest.
The material models useful for the inverse FEA of the present invention include rigid body material models (such as set with LS-DYNA syntax: *MAT_RIGID, etc.), elastic material models (such as set with LS-DYNA syntax: *MAT_ELASTIC, etc.), viscoelastic material models (such as set with LS-DYNA syntax: *MAT_VISCOELASTIC, etc.), hyperelastic material models (such as set with LS-DYNA syntax: *MAT_MOONEY-RIVLIN_RUBBER, *MAT_BLATZ-KO_RUBBER, *MAT_BLATZ-KO FOAM, *MAT_OGDEN_RUBBER, *MAT_HYPERELASTIC RUBBER, etc.), hyperelastic material models including viscoelasticity, hyperelastic soft tissue material models (such as set with LS-DYNA syntax: *MAT_SOFT_TISSUE) and any other material models available. The material models may also be isotropic, anisotropic, or orthotropic. The boundary conditions may be applied to any node, any point, any element, and/or any segmented part of the finite elements and may include translational constraints, rotational constraints, joints, contacts with certain coefficient of friction values, constant distances, pressures, forces, and the like.
In one embodiment, where the reconstructed part of the body includes the vaginal cavity defined as a cavity between the vesico vaginal tissue and the recto vaginal tissue, and segmented parts corresponding to the vesico vaginal tissue, the recto vaginal tissue, the bladder, the urethra, the uterus including the cervix, the rectum, and the pelvic bone, the vesico vaginal tissue and the recto vaginal tissue may comprise the Blatz-Ko hyperelastic foam model (set with LS-DYNA syntax: *MAT_BLATZ-KOFOAM), the bladder may comprise the Mooney-Rivlin hyperelastic rubber model (set with LS-DYNA syntax: *MAT_MOONEY-RIVLIN_RUBBER), the urethra may comprise the Blatz-Ko hyperelastic rubber model (set with LS-DYNA syntax: *MAT_BLATZ-KO_RUBBER), the uterus including the cervix and the rectum may comprise the elastic material model (set with LS-DYNA syntax: *MAT_ELASTIC), and the pelvic bone may comprise the rigid body model (set with LS-DYNA syntax: *MAT_RIGID). In this embodiment, as the boundary conditions, the pelvic bone may comprise translational and rotational constraints in x, y, z directions (set within the code lines for *MAT_RIGID) and nodes on the volume boundary may comprises translational and rotational constraints in x, y, z directions.
In another embodiment, the constitutive equations used to represent the biomechanical response of the various soft tissue regions, including but not limited to the vaginal wall tissues, the bladder wall, the smooth muscle fibers in the urethra, the cervix the uterus, and the pelvic floor, may include point to point description of vector fields to represent local collagen and muscle fiber direction(s). These fiber directions can be incorporated into the hyperelastic material modeling framework to render anisotropy to the behavior of the tissue. Continuum based transversely isotropic single fiber family reinforced hyperelastic models (such as set with LS-DYNA syntax: *MAT_SOFT_TISSUE), or multiple fiber family orthotropic hyperelasticity models (such as disclosed by Haridas B, Weiss J W, Grood E S, and Butler DL: Orthotropic Hyperelasticity with Two Fiber Families: A Study of the Effect of Fiber Organization on Continuum Mechanical Properties in Soft Tissues, International Symposium on Ligaments and Tendons, U California San Francisco, 2004) implemented through user subroutines for specialized material behavior in ABAQUS® (UMAT) can also be used to simulate more complex anisotropic behavior. Fiber directions in various tissues can be determined by quantitative stereology techniques applied to histology studies on cadaveric tissue as well as from diffusion tensor imaging techniques available in MRI based imaging technology. The constitutive equations could also include voluntary or involuntary smooth muscle activation capabilities via implementation of an active element model into the user defined material subroutines in LS-DYNA® and/or ABAQUS®.
Values obtained or estimated from public literature may be used as starting values for the parameters of the material models of the tissues or organs before the inverse FEA of the present invention. For example, the following publications disclose mechanical properties of some skeletal muscles which may be used to set starting values for the parameters of the material models of muscular tissues in pelvic floor muscles: Passive Transverse Mechanical Properties of Skeletal Muscle Under In vivo Compression , by Bosboom et al., published in the Journal of Biomechanics, 34 (2001) 1356-1368; and Three - dimensional Finite Element Modeling of Skeletal Muscle Using a Two - domain Approach: Linked Fiber - matrix Mesh Model , by Yucesoy et al., published in the Journal of Biomechanics, 35 (2002) 1253-1262. Based on information on such publications, for example, skeletal muscles such as the levator ani may include the elastic material model (set with LS-DYNA syntax: *MAT_ELASTIC) with starting Young's modulus value of between 15 kPa and 150 kPa and starting Poisson's ratio value of 0.4.
Approximation of the parameters of the material models for the tissues or organs of interest using in-vivo data on the effect associated with any change in the body may precede the inverse FEA on the use of the device of the present invention inserted into the body. In one embodiment, where the part of the body including the tissues or organs and the body cavity of interest includes the vaginal cavity defined as a cavity between the vesico vaginal tissue and the recto vaginal tissue, the vesico vaginal tissue, the recto vaginal tissue, the bladder, the urethra, the uterus including the cervix, the rectum, and the pelvic bone, such a change in the body may include various states of filling of the bladder and various states of filling of the rectum. When the change of filling of the bladder is selected as the change in the body, the approximation of the parameters of the material models for the tissues or organs of interest can be achieved, by, using any imaging device, imaging the anatomy of the part of the body at different states of filling of the bladder, followed by inverse FEA until simulated positions and dimensions of the tissues and organs in the part of the body approximate the actual positions, dimensions thereof from the actual images at different volumes of the bladder corresponding the different states of filling volumes and intravesicle pressures within the bladder. Vesicle pressures can be easily measured during above said experiments via transurethral placement of a microcatheter based pressure transducer in the bladder vesicle.
Another example of the change in the body may include various positions of the subject (e.g., standing, leaning over, sitting lying, etc.). The approximation of the parameters of the material models for the tissues or organs of interest can be achieved by, using any imaging device which allows different positions of the subject such as an open MRI device, for example, available from Fonar Corp. of Melville, N.Y., under the trade name of Upright® MRI 0.6 T, imaging the anatomy of the part of the body with different positions of the subject, followed by inverse FEA until simulated positions and dimensions of the tissues and organs in the part of the body approximate the actual positions and dimensions thereof from the actual images taken by the imaging device over different positions of the subject.
Once the numerical model for the expandable tissue strain device 30 and the part of the body 12 including the tissues or organs, and the body cavity of interest are constructed, the numerical simulation may be conducted, where the numerical model of the expandable tissue strain device is placed in the body cavity of the numerical model of the part of the body at the same position as in the actual in-vivo measurement with the device of the present invention and the numerical model of the expandable tissue strain device is inflated up to the same volume as in the actual in-vivo measurement with the device of the present invention. This numerical simulation can be done by any known FEA code. Once processing of the simulation is completed, the simulation results may be obtained using any appropriate software package for post-processing for FEA such as ABAQUS® Viewer from Abaqus Inc. of Providence, R.I., LS-PREPOST® from Livermore Software Technology Corp. of Livermore, Calif., Hyperview® from Altair Engineering Inc. of Troy, Mich., EnSight® from Computational Engineering International of Apex, N.C., ANSYS LS-DYNA® from Ansys Inc. of Cannonsburg, Pa.
In one embodiment, where the FEA code is LS-DYNA®, LS-PREPOST® from Livermore Software Technology Corp. of Livermore, Calif., or Hyperview® from Altair Engineering Inc. of Troy, Mich., can be used for the post-processing. The simulation results are subjected to qualitative and/or quantitative comparison with the actual in-vivo measurement results under the comparable test conditions (The actual in-vivo measurement test conditions may be obtained by synchronizing the pressures and volumes of the expandable tissue strain device to the B-mode ultrasound signal in time in one embodiment where the external imaging device 60 is an ultrasound device available from Medison-GE Healthcare of Waukesha, Wis.)
In one embodiment, the simulation results and the actual in-vitro measurement results are compared in terms of the quantities including the change in pressure of the expandable tissue strain device and the change in position or dimension of the tissues or organs of interest. The change in position or dimension of the tissues or organs of interest may be compared by projecting or superimposing the simulated images of the tissues or organs on the actual images thereof taken by the imaging device of the present invention. Alternatively, the change in position or dimension of the tissues or organs of interest may be compared by comparing certain dimensions defining the tissues or organs of interest taken from the simulation results and from the corresponding actual images of the tissues or organs.
If the qualitative and/or quantitative comparison between the simulated results and the actual results does not reach agreement within desired accuracy, adjust the parameters in the material models and then iterate the simulation and the comparison between the simulated results and the actual results until the simulated results match the actual results within desired accuracy. Once the agreement is achieved, the biomechanical properties of the tissues or organs of interest are finally determined in the form of the material models comprising the optimized parameters.
In one embodiment, where the part of the body including the tissue or organs of interest includes the vaginal cavity defined as a cavity between the vesico vaginal tissue and the recto vaginal tissue, the vesico vaginal tissue comprising the Blatz-Ko hyperelastic foam model (set with LS-DYNA syntax: *MAT_BLATZ-KOFOAM), the recto vaginal tissue comprising the Blatz-Ko hyperelastic foam model (set with LS-DYNA syntax: *MAT_BLATZ-KOFOAM), the bladder comprising the Mooney-Rivlin hyperelastic rubber model (set with LS-DYNA syntax: *MAT_MOONEY-RIVLIN_RUBBER), the urethra comprising the Blatz-Ko hyperelastic rubber model (set with LS-DYNA syntax: *MAT_BLATZ-KO_RUBBER), the uterus including the cervix comprising the elastic material model (set with LS-DYNA syntax: *MAT_ELASTIC), the rectum comprising the elastic material model (set with LS-DYNA syntax: *MAT_ELASTIC), and the pelvic bone comprising the rigid body model (set with LS-DYNA syntax: *MAT_RIGID), the parameters in the material models are finally defined in the format of LS-DYNA input files, as Table 2 below.
TABLE 1
Material Model Parameters for LS-DYNA (Units: mm-mg-sec)
Variable #
2
3
4
5
6
7
8
Vesico vaginal
0.100e−08
0.00250
tissue
Recto vaginal
0.100e−08
0.00125
tissue
Bladder
0.100e−08
0.4990
0.0075
0.00250
Urethra
0.100e−08
0.1000
Uterus and cervix
0.200e−08
0.0500
0.2000
Rectum
0.400e−08
0.9000
0.3500
The dimensions and values disclosed herein are not to be understood as being strictly limited to the exact numerical values recited. Instead, unless otherwise specified, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as “40 mm” is intended to mean “about 40 mm.”
Every document cited herein, including any cross referenced or related patent or application, is hereby incorporated herein by reference in its entirety unless expressly excluded or otherwise limited. The citation of any document is not an admission that it is prior art with respect to any invention disclosed or claimed herein or that it alone, or in any combination with any other reference or references, teaches, suggests or discloses any such invention. Further, to the extent that any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in a document incorporated by reference, the meaning or definition assigned to that term in this document shall govern.
While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention. | A computational model of the internal human pelvic environment. The model comprises meshed finite element regions corresponding to internal tissues or organs selected from the group consisting of pelvic muscles, vagina, vaginal walls, intestinal tissues, bowel tissues, bladder, bladder walls, cervix, and combinations thereof. | 0 |
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is based upon and claims the benefit of U.S. Provisional Patent Application No. 61/460,826 filed Jan. 7, 2011; and is a divisional application of patent application Ser. No.: 13/344,005; filed Jan. 5, 2012.
TECHNICAL FIELD
[0002] The present invention relates generally to a system for storing and managing the cores of rolls of sheet form material. After the sheet form material is unwound from the core, the core is transferred to the core storage and management system for further processing. The present invention is related to our co-pending application Ser. No. 12/928,231 for an Automatic Core Cleaning Apparatus and co-pending application Ser. No. 12/925,084 for an Automatic Core Joining and Cutting Apparatus. The present invention may be used independently of or variously in combination with the technology disclosed and claimed in the related applications. The co-pending applications are incorporated herein by reference.
SUMMARY OF THE INVENTION
[0003] The present invention is a highly adaptable core storage and management system that can be adapted for use in any industrial setting where sheet form material is provided on large rolls having cores. After the sheet form material is dispensed from the rolls during the manufacturing process, the core remains, usually having some remnants of sheet form material still attached. The core is cleaned, inspected and either stored for reuse, repaired and stored for reuse, or disposed of. The core storage and management system of the present invention is intended to accumulate the spent cores, clean cores, and rejected cores for either reuse or disposal. The core storage and management system will monitor the lengths and diameters of the cores and sort the cores of various sizes into storage racks designated for each core of various sizes. The storage and management system of the present invention can be designed for use in conjunction with a core cutting and joining apparatus such as that disclosed in our co-pending U.S. patent application Ser. No. 12/925,084. The core storage and management system of this invention can also be used in combination with a core cleaning apparatus as disclosed in our co-pending U.S. patent application Ser. No. 12/928,231.
[0004] Ideally, the core storage and management system of the present invention will identify clean cores of various sizes and diameters and store the clean cores in specified racks.
[0005] The core storage and management system is extremely adaptable in that it can utilize any number of storage racks and the storage racks can be adaptable to contain stacks of individual cores or cores of various lengths and diameters.
[0006] Cameras can be used to inspect incoming cores to see if they are clean or damaged. The core storage and management system of this invention includes an inspection station for the manual inspection of cores for damage. Any damaged cores can either be sent to a core cutter and joiner machine located proximate the core storage and management system, or disposed of if damaged too badly for repair.
[0007] The core storage and management system uses sensor arrays to monitor the length and diameter of each core member it receives. The core storage and management system maintains a record of the total number of each core size received and interfaces with the manufacturing processes to ensure that cores of proper diameter and length are being delivered to the proper cleaning and repair stages within the facility.
[0008] RFID tags are affixed to each core except for those damaged too badly for repair. The RFID tags contain information regarding the size and condition of each core (i.e. whether acceptable for re-use as is, in need of cleaning, in need of repair), and storage location.
[0009] The core storage and management system is used at facilities that convert product on cores and provides for reuse of the cores. The core storage and management system stores cores, identifies core lengths and diameters, identifies cores that are damaged and can be salvaged via a core cutting and joining apparatus, manages inventory, processes outbound orders by either utilizing existing inventory or creating the cores via the core cutter and joiner apparatus. The core storage and management system significantly reduces manpower and safety issues.
[0010] Other objects and advantages of the present invention will become apparent to those skilled in the art upon a review of the following detailed description of the preferred embodiments and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a top view of a core storage system as used with the present invention.
[0012] FIG. 2 is a top view of the core storage unit of the system of FIG. 1 .
[0013] FIG. 3 is a side view of the core storage unit of FIG. 2 .
[0014] FIG. 4 is an end view of the core storage unit of FIG. 2 .
DETAILED DESCRIPTION OF THE INVENTION
[0015] The core storage unit section of the management system of the present invention is shown in FIGS. 2-4 as a simple layout. The core storage unit section 20 comprises six racks 10 for storing cores C. The number, size and layout of racks 10 in the storage unit can vary depending on the requirements of the manufacturing facility. The racks 10 are designed to inventory and store cores C of either the same size or of varying sizes (as shown in FIGS. 2-4 ) and lengths (as shown in FIG. 2 ). The storage system includes an overhead crane 46 for receiving and delivering clean cores to the appropriate rack 10 for the specific size and length of core C being conveyed. The overhead crane 46 rides across the top of frame 18 to deliver a received core to its appropriate rack or to remove a core for delivery from its appropriate rack 10 . The frame 18 extends longitudinally between ends 19 and laterally between sides 21 . The crane 46 is mounted for movement both longitudinally and laterally in order to place core C in the appropriate rack 10 for its size (diameter) and length. The crane 46 has clamps 48 actuatable between a closed position for gripping the cores and an open position for releasing the cores C.
[0016] Referring now to FIG. 1 , the core storage management system includes the core storage unit section 20 and an inspection/cleaning section 30 . The core storage unit section 20 extends longitudinally between a core joiner station 47 (for example of the type disclosed in application Ser. No. 12/925,084) and a manual inspection station 44 . The core joiner station 47 is not necessarily part of the system of the present invention. It could be located at a position remote from the system. The inspection/cleaning station 30 is adjacent to the core storage unit section 20 and is positioned to receive incoming cores C via a cross conveyor 52 extending there between.
[0017] A loading conveyor 45 receives cores C and moves them laterally onto the core storage unit section 20 and then to the cross conveyor 52 and onto the inspection/cleaning station 30 . The inspection/cleaning station 30 includes core cleaning assembly 43 that cuts any remnant material from the used core C. The remnant material is transferred to a final destination, for example a pulper, bailer, or other processing unit. After the core C is cleaned it is then inspected to determine whether it is damaged or whether it is acceptable for reuse.
[0018] The inspection station includes at least one camera 41 positioned to inspect the core C. The camera 41 is preferably movable such that it can inspect both ends of the core C. In other embodiments, a second camera 42 may be included at the inspection station 30 . If the core C is clean, it is delivered to a second cross conveyor 53 for return to the core storage unit section 20 . An overhead crane 46 picks up the clean core and transports it to its proper rack 10 for storage. If the core C fails inspection, it is sent to a manual inspection station 44 for operator intervention.
[0019] Adjacent to and parallel with the loading conveyor 45 is an unloading conveyor 56 . The loading conveyor 45 and unloading conveyor 56 are mounted on mechanism which is moveable longitudinally. Such longitudinal movement moves the two conveyor 45 , 56 from a first longitudinal position at which the loading conveyor 45 is aligned with the first cross conveyor 52 for delivery of cores C thereto to a second position at which the unloading conveyor 56 is aligned with the first cross conveyor 52 so that it can receive cores C being removed from the core management system. However, the position and layout of the various units of the core storage management system 10 (i.e. core storage unit section 20 , racks 10 , core cleaning assembly 43 , inspection station 30 and conveyors) may vary. Accordingly, the method of moving the cores may vary from site to site.
[0020] The storage racks 10 can variously contain individual used and clean cores. The clean cores C can be retrieved from the appropriate storage racks 10 for delivery to the unloading conveyor 56 .
[0021] The core storage and management system further includes an inspection station 44 wherein each core can be delivered for manual inspection. If any of the cores are damaged, but salvageable, they can be delivered by crane 46 to the adjacent core cutter and joiner apparatus 47 . A properly joined core can then delivered by overhead crane 46 to its appropriate storage rack 10 .
[0022] It should be noted that the layout of the various components is not necessarily as shown in FIG. 1 . The components can be used in a variety of combinations and locations depending on the requirements and layout of the facility in which it is used.
[0023] This description of the core storage and management system is intended to be illustrative. As explained herein the system is extremely adaptable for use in a variety of manufacturing settings. The scope of the present invention is set forth in the appended claims. | A system and method for receiving, handling and storing used rolls following unwinding of sheet material therefrom includes:
(a) transferring the cores to a remnant cleaning station, (b) inspecting for (i) remnant material, (ii) repairable damage or (iii) irreparable damage; and (c) for those cores cleaned, repaired, or satisfactory as is, transferring them to a storage rack for the specific size and length. | 8 |
BACKGROUND OF THE INVENTION
The present invention relates to an electrode which has been specifically designed for carrying out spot welding operations, as well as a method for making it.
As is known, in pressure spot welding operations and, in particular, in resistance spot welding operations, the welding heating is produced by the welding current passing through the contacting surfaces of the pieces to be welded: in this method, the electrode portion which is subjected to the greatest thermal and mechanical stress is the electrode end portion contacting one of the pieces to be welded.
In fact in this portion the welding current, which depends on the electrical resistance of the region to be welded and the voltage applied to the electrodes, is very high so as to reach the welding temperature in a short time in order to prevent heat losses from occurring.
Moreover, a suitable pressure must be applied to the welding region in order to properly clamping the pieces to be welded.
According to known making methods, the welding electrodes which, in addition to a high electric conductivity, must have good resistance characteristics, are made from electrolytic copper, the starting mechanical resistance of which is increased by means of molding or extruding operations.
In order to further increase the mentioned mechanical resistance, there are also used copper alloys (such as elconite, copper-beryllium alloys, copper-zirconium alloys, copper-chromium-zirconium alloys) which however, in respect of electrolytic copper, lead to a greater electric resistance with a consequent decreased conductivity.
Moreover, the shape of the electrode end portions must correspond to the characteristics of the pieces to be welded, and the electrode active surfaces are usually held in a cleaned condition by means of files or emery paper, or, if these surfaces are greatly worn, by means of turning operations.
As it should be apparent the above mentioned maintenance operations are rather tedious and complex and they must be carried out each time the electrode is oxidized and, hence, its active portion has a poor conductivity.
In fact, an oxidized active region leads to a deformation of the electrode operating part, because of the greater current intensity which must be applied to the electrode.
Moreover, as the electrode is very oxidized, the welding voltage is to be increased, in order to provide the required low welding resistance, which leads to the generation of electric arc.
In the switch electric contact field, or in the sliding contact field, there have been already used alloys consisting of silver and colloidal or amorphous graphite, including silver powder with a density of 3g/cm 2 , the component elements of said alloys being mixed in a ball mill. Because of the comparatively great size and ductility of the silver powder, said silver powder, during the mixing operation, is laminated and work-hardened and, accordingly, it can not be easily and properly compacted.
According to another method, the silver powder is carried out in a ball mill, by using colloidal water-dispersed graphite: however, also in this method, the silver powder is subjected to lamination and work-hardening.
The mixed silver powder is then compacted, and, during the compaction step, said silver powder is further work-hardened and layered, because of the comparatively large size of the silver powder particles.
The subsequent sintering step is carried out in a very long thermal cycle, of the order of several hours, in which water is slowly evaporated.
The thus obtained sintered material has a hardness from 40° to 75° Brinell, which is much smaller than the hardness for making spot welding electrodes.
In order to improve the mentioned small hardness values, to the silver powder other metal materials are added with a consequent decrease of the electric conductivity.
SUMMARY OF THE INVENTION
Accordingly, the main object of the present invention is to overcome the above mentioned drawbacks by providing an electrode, for spot welding operations, which is provided, at least at its active portion, with a practically inalterable surface which, in addition to having high electric conductivity values, does not require any maintenance operations.
Another object of the present invention is to provide a spot welding electrode able of achieving a high welding temperature in a short time, and which may also be used with very high welding currents.
Another object of the present invention is to provide a method for making the above spot welding electrodes which affords the possibility of making spot welding electrodes very reliable and devoid of any defects.
According to one aspect of the present invention, the above mentioned objects, as well as yet other objects, which will become more apparent hereinafter, are achieved by a spot welding electrode having an electrically conductive body, characterized in that it comprises, at least at its active portion, a silver powder sintered layer, with particle size from 1 to 10 microns, and crystalline graphite.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The invention will become more apparent from the following detailed description of a preferred embodiment of a spot welding electrode, given by way of a not limitative example.
More specifically, the electrode according to the invention is made by providing a spot welding electrode body, of conventional shape, which advantageously, though not necessarily, may be made starting from electrolytic copper.
At its active portion, that is at the point portion of the electrode which will contact the pieces to be welded, there is applied a layer, which may consist of a sintered small plate which is applied to the electrode body by means of force fitting or mechanical anchoring means.
The mentioned sintered layer, or small plate, is made starting from a sintered extruded material comprising silver powder, of very fine particle size from 1 to 10 microns, which has been mixed with crystalline graphite.
The sintered and extruded material is prepared with a graphite contents of substantially 1 to 20%, the silver powder, which comprises the remaining portion, being present in a rate of substantially 99 to 80%.
For making the electrode, the silver powder and crystalline graphite components are dry mixed, under rolling and stirring, so as not to cause the silver powder particles to be work-hardened.
During the mixing step the crystalline graphite particles coat and "saponify" the silver powder particles, thereby perfectly homogenizing the mixture.
After the mixing step, the silver powder is subjected to a pressing operation at a pressure from 4,000 to 6,000 Kg/cm 2 :in this way, since the compacted silver powder is not work-hardened, its particles are friction welded, because of their mutual sliding onto one another, which welding will be subsequently completed by means of a sintering step which is carried out for about 30 minutes at a temperature from 800° to 920° C.
The thus obtained sintered material is then extruded to provide the graphite particles with a filamentary morphology thereby improving the mechanical-physical properties of the sintered material during the working step and providing a sintered material which is very suitable for carrying out spot welding operations.
In particular, the extruded sintered material will have a hardness greater than 120 Brinell, that is substantially corresponding to the hardness of conventional spot welding electrodes, but with very high mechanical-physical properties.
Moreover a portion of the above disclosed sintered material may be coupled to a conventional spot welding electrode body, made of copper or copper alloys, by means of conventional molding methods and the like.
From the above disclosure, it should be apparent that the invention fully achieves the intended objects.
In particular the fact is to be pointed out that the use of the very reduced particle size silver powders, in combination with a crystalline graphite, provides a very homogeneous and even product which is very suitable for making spot welding electrodes.
Moreover the disclosed silver powder-crystalline graphite layer coating the electrode body protects the electrode from any oxidizing phenomena and overcome the need of carrying out descaling operations for holding the electrode in a proper operating condition.
While a preferred embodiment of the electrode according to the present invention has been thereinabove disclosed, it should be apparent that the disclosed embodiment is susceptible to several modifications and variations without departing from the spirit of the invention and scope of the accompanying claims. | The electrode comprises an electrically conductive body including, at least at its active portion, a sintered layer of silver powder having a particle size from 1 to 10 microns and crystalline graphite. | 1 |
BACKGROUND OF THE INVENTION
This invention relates to an improved process for preparing hydroxy ethyl p-(βhydroxyethoxy) benzoate. More particularly, this process involves the reaction of p-hydroxybenzoic acid with ethylene carbonate to prepare the title compound.
The reaction of ethylene carbonate with phenol or phenolic compounds in the presence of a cesium or potassium iodide catalyst to prepare hydroxyalkylphenyl ether compounds is disclosed in U.S. Pat. No. 4,261,922. The use of acid or base catalysts for such reactions is described in U.S. Pat. Nos. 2,448,767 and 3,283,030.
British Pat. No. 742,793 discloses that methyl esters of p-hydroxybenzoate can be reacted with cyclic ethylene carbonate to prepare a linear polyester. In the provisional specification of this application, it is noted that cyclic glycol carbonates react readily with free dicarboxylic acids. Diglycol esters are acid of 3:1 or higher. formed at mole ratios of cyclic carbonate to dicarboxylic
Japanese Pat. No. 75 16,839 (Chem. Abst. 83:180287u) describes the preparation of hydroxy ethyl p-(βhydroxyethoxy) benzoate by the reaction of p-hydroxybenzoic acid and ethylene oxide. However, this reaction is prone to the formation of poly(ethoxy) groups in the product and is not easily adapted to commercial operations.
The object of the subject process is to provide an improved method of making hydroxy ethyl p-(βhydroxyethoxy) benzoate, hereinafter referred to as "HEHEB". HEHEB is useful as a monomer for fiber-forming polyesters and also as a chain extender for polyurethanes.
SUMMARY OF THE INVENTION
The invention is an improved process for making HEHEB. This process comprises contacting in the liquid phase ethylene carbonate and p-hydroxybenzoic acid in a mole ratio of at least about 2.5 to 1 at a temperature in the range from about 150° C. to about 180° C. in the presence of a catalytic amount of KI, CsI, KBr, KF, or CsF. The HEHEB is then recovered from the reaction medium.
DETAILED DESCRIPTION OF THE INVENTION
It has been surprisingly found that by reacting excess ethylene carbonate with p-hydroxybenzoic acid at specific catalyzed reaction conditions, HEHEB can be prepared in high yield. There is little oligomer or polyester formed in preferred embodiments of this process. Moreover, few poly(ethoxy) groups are introduced. In preferred embodiments of this invention yields of at least about 70 mole percent, more preferably at least about 90 mole percent, HEHEB based on the p-hydroxybenzoic acid reactant are attainable.
The ethylene carbonate and p-hydroxybenzoic acid reactants are both well-known compounds. Both these reactants are available commercially.
The reactants can be brought together in any convenient manner. The use of solvents or diluents inert in the reaction is operable, but not necessary. Advantageously, the reaction is conducted neat.
The mole ratio of ethylene carbonate to p-hydroxybenzoic acid should be at least about 2.5:1, because an excess of ethylene carbonate is necessary to produce the desired HEHEB product in good yield. At a mole ratio of ethylene carbonate ("EC") to p-hydroxybenzoic acid ("PHBA") of 2:1, p-(hydroxyethoxy)benzoic acid is formed almost exclusively. Even larger excesses of ethylene carbonate are preferred. A mole ratio of EC:PHBA of at least about 3:1 is preferred, with at least about 4:1 being more preferred and at least about 4.5:1 being most preferred. Conveniently, the ratio of EC:PHBA does not exceed 10:1.
The reaction temperature is preferably at least about 150° C., more preferably at least about 155° C. and most preferably at least about 160° C., as lower temperatures result in the formation of p-(hydroxyethoxy)benzoic acid reaction. Reaction temperatures above about 180° C. should be avoided because of possible polymerization of the product. Reaction temperatures in the range from about 165° to about 175° C. are especially preferred.
A number of alkaline earth metal halides, e.g., MgBr 2 were found to promote formation of poly(ethoxy) moieties. Consequently, these salts are not suitable as catalysts in the subject process. Of those catalysts found suitable, KI, CsI and KBr are preferred, with KI being most preferred.
The loading of the catalyst is not critical so long as the amount present is adequate to promote the desired reaction. In general, the catalyst should be present at a loading of from about 1 to about 10 percent of the total weight of the reactants. Preferably, the catalyst is present in a loading of from about 3 to about 5 percent of the reactants weight.
The reaction medium is advantageously stirred or otherwise agitated to provide good heat and mass transfer. Operable means for agitation will be apparent to the skilled artisan.
The time required for the reaction to reach substantial completion depends on the reaction temperature, the catalyst, the catalyst loading, the concentration of the reactants and other factors. In preferred embodiments of this invention a reaction time of from about 1 hour to about 2 hours is adequate. Less preferred embodiments of this invention may require much longer reaction times. The extent of reaction is conveniently monitored by analysis of the reaction medium or monitoring the carbon dioxide evolved from the medium. The process can be conducted batchwise or continuously.
The HEHEB product can be isolated by conventional techniques, such as extraction followed by distillation. One convenient technique involves washing the reaction medium with water one or more times. Some of these aqueous washes can be saturated with NH 4 OH or NaHCO 3 followed by acidic neutralizing washes. The washed product layer is separated, dissolved in methylene chloride and washed again with water. The organic layer is separated, treated with a dehydrating agent and the methylene chloride evaporated at reduced pressure. The HEHEB product is isolated in preferred embodiments of this invention in yields of at least about 70 mole percent based on the p-hydroxybenzoic acid, more preferably at least about 90 mole percent.
The following example is presented to illustrate the invention.
EXAMPLE 1
To a reaction vessel equipped with a means for controlling and measuring temperature, a stirrer, gas outlet and condenser was charged 7.95 grams of p-hydroxybenzoic acid (0.0576 mole), 15.21 grams of ethylene carbonate (0.1728 mole) and 0.85 gram KI (0.0051 mole). The reaction mixture was heated to 175° C. Stirring of the reaction mixture was initiated as soon as it became liquid. The gas evolving from the reaction mixture was trapped and analyzed. After about two hours the heating was discontinued. The crude product was a yellow viscous liquid.
After the product mixture had cooled to 70° C., 1 liter of warm (60° C.) water was added and the mixture stirred for 10 minutes. The stirring was stopped and the aqueous layer removed. The organic layer was then washed twice more, first with a saturated aqueous NaHCO 3 solution and then water. The product was dissolved in methylene chloride and dried over anhydrous CaSO 4 . The methylene chloride was then removed by evaporation at reduced pressure. The residue was identified by conventional methods of analysis as hydroxy ethyl p-(βhydroxyethoxy) benzoate. | Excess ethylene carbonate is reacted with p-hydroxybenzoic acid in the presence of a catalytic amount of potassium iodide, potassium bromide, potassium fluoride, cesium iodide or cesium fluoride to make hydroxyethyl p-(hydroxyethoxy)benzoate. | 2 |
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a coupling detector for a connector for detecting whether the connector to be employed for electric connection of wire harnesses etc. installed in motor vehicles are properly coupled or not.
[0002] Especially in the connector to be employed in a wiring system for an air bag or the like in a motor vehicle, for example, it is necessary to strictly check whether the connector has been completely coupled or not.
[0003] For this purpose, there have been conventionally proposed various types of connectors, such as a connector in which coupling can be mechanically detected from a state of movement of a slider, a connector in which coupling can be electrically detected, and a connector provided with these two functions.
[0004] Among them, the connector as described below has been known as the connector of the type in which coupling can be electrically detected.
[0005] In FIG. 21, a connector 101 capable of electrically detecting the coupling includes a male connector 102 and a female connector 103 . The male connector 102 has a male connector housing 104 made of synthetic resin, a pair of female terminals 105 (only one is shown in the drawing), and a short-circuiting metal piece 106 adapted to short-circuit the pair of the female terminals 105 . There is formed inside the male connector housing 104 , a chamber 107 for the pair of the female terminals 105 and the short-circuiting metal piece 106 . There is also formed outside the male connector housing 104 , a locking arm 109 having a locking projection 108 . Electric wires 110 are press-fitted to the female terminals 105 , and the short-circuiting metal piece 106 is formed with an elastic arm 111 .
[0006] The female connector 103 has a female connector housing 112 , a pair of male terminals 113 (see FIG. 22). There are formed inside the female connector housing 112 , a chamber 114 for the pair of the male terminals 113 , and a connector engaging room 116 for the male connector 102 . There are formed in the connector engaging room 115 , a partition wall 116 existing between the pair of the male terminals 113 , an insulating piece 117 integrally formed with the partition wall 116 , and a locking hole 118 for engagement with the above described locking projection 108 . The insulating piece 117 is formed so as to correspond to a contact position between the female terminals 105 and the elastic arm 111 of the male connector 102 . The male terminals 113 are arranged in such a manner that their distal ends may project into the connector engaging room 115 . Electric wires 119 are press-fitted to backward ends of the male terminals 113 .
[0007] In an initial state of the coupling as shown in FIG. 23, the elastic arm 111 is in contact with the female terminals 105 of the male connector 102 (see FIG. 21) to establish a short circuit between the female terminals 105 . When the female connector 103 is moved from this state in a direction of an arrow to initiate the coupling, the male terminals 113 are inserted into the female terminals 105 as shown in FIG. 24, and at the same time, the insulating piece 117 slides along contact faces of the female terminals 105 with respect to the elastic arm 111 (a state on the way of the coupling). Then, as shown in FIG. 25, as the female connector 103 further continues to move and the coupling of the connector 101 has been completed, the insulating piece 117 pushes up the elastic arm 111 to cancel the short circuit between the female terminals 105 , needless to say that the electrical connection between the male terminals 113 and the female terminals 105 has been completed.
[0008] Therefore, by electrically detecting that the short circuit has been canceled, the state of the coupling in the connector 101 can be confirmed.
[0009] By the way, in the above described configuration, there has been such a problem that when the male connector 102 and the female connector 103 are coupled, the insulating piece 117 may be deformed or broken by diagonal or forcible insertion. Cancellation of the short circuit may not be reliably conducted, resulting in damage in reliability of electrical detection of the coupling.
SUMMARY OF THE INVENTION
[0010] It is therefore an object of the invention is to provide a coupling detector for a connector in which cancellation of a short circuit can be reliably conducted, and reliability of electrical detection of the coupling can be enhanced.
[0011] In order to achieve the above object, according to the present invention, there is provided a coupling detector for electrically detecting whether a first connector and a second connector are plenarily coupled with each other, comprising:
[0012] a conductive member provided in the first connector together with a plurality of terminal fittings, the conductive member including elastic arms associated with the respective terminal fittings, each elastic arm being divided into a first conductive piece and a second conductive piece which are moved together, the first conductive piece brought into contact with the terminal fitting when the first connector and the second connector are disengaged, the second conductive piece being away from the terminal fitting when the first connector and the second connector are disengaged; and
[0013] insulative members provided in the second connector so as to be associated with the respective elastic arms, each insulative member including a first insulative piece and a second insulative piece, the first insulative piece inserted between the terminal fitting and the first conductive piece when the first connector and the second connector are engaged, the second insulative piece moving the second conductive piece in a direction away from the terminal fitting when the first connector and the second connector are engaged.
[0014] In this coupling detector, even though one of the first and the second insulative pieces is deformed or broken, the other one acts on the associated conductive piece to cancel the short circuit.
[0015] Therefore, the short circuit can be reliably canceled so that reliability of electrical detection of the coupling is enhanced.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The above objects and advantages of the present invention will become more apparent by describing in detail preferred exemplary embodiments thereof with reference to the accompanying drawings, wherein:
[0017] [0017]FIG. 1 is a perspective view showing an outer appearance of a connector provided with a coupling detector according to one embodiment of the present invention;
[0018] [0018]FIG. 2 is an exploded perspective view of a male connector;
[0019] [0019]FIG. 3 is an exploded perspective view of a female connector;
[0020] [0020]FIG. 4 is a sectional view of the connector;
[0021] [0021]FIG. 5 is a front view of a male connector housing (encircled is an enlarged view of an essential part);
[0022] [0022]FIG. 6 is a sectional view of the male connector housing (encircled is an enlarged view of the essential part);
[0023] [0023]FIG. 7 is a front view of a female connector housing;
[0024] [0024]FIG. 8 is a sectional view of the female connector housing;
[0025] [0025]FIG. 9A is a plan view showing a short-circuiting metal piece;
[0026] [0026]FIG. 9B is a front view showing the short-circuiting metal piece;
[0027] [0027]FIG. 9C is a sectional view showing the short-circuiting metal piece;
[0028] [0028]FIG. 10 is an enlarged sectional view of the male connector housing and the female connector housing provided with the short-circuiting metal piece;
[0029] [0029]FIG. 11A is a plan view showing the connector in an initial state of coupling;
[0030] [0030]FIG. 11B is a sectional view of FIG. 11A;
[0031] [0031]FIG. 12A is a plan view showing the connector in a state where the locking has started;
[0032] [0032]FIG. 12B is a sectional view of FIG. 12A;
[0033] [0033]FIG. 13A is a plan view showing the connector in a state just before the locking;
[0034] [0034]FIG. 13B is a sectional view of FIG. 13A;
[0035] [0035]FIG. 14 is an enlarged sectional view of an essential part showing a state in which a short circuit has been established between male terminals,
[0036] [0036]FIG. 15 is an enlarged sectional view of an essential part in a state in which the short circuit between the male terminals is being canceled;
[0037] [0037]FIG. 16 is an enlarged sectional view of the essential part in a state in which the short circuit between the male terminals has been completely canceled;
[0038] [0038]FIG. 17A is a plan view showing the connector in a completely coupled state;
[0039] [0039]FIG. 17B is a sectional view of FIG. 17A,
[0040] [0040]FIG. 18A is a plan view showing the connector in a state where cancellation of the lock has started;
[0041] [0041]FIG. 18B is a sectional view of FIG. 18A;
[0042] [0042]FIG. 19A is a plan view showing the connector in a state where the lock has been cancelled;
[0043] [0043]FIG. 19B is a sectional view of FIG. 19A;
[0044] [0044]FIG. 20A is a plan view showing the connector in a disengaged state;
[0045] [0045]FIG. 20B is a sectional view of FIG. 20A;
[0046] [0046]FIG. 21 is a sectional view of a connector provided with a related coupling detector;
[0047] [0047]FIG. 22 is a perspective view of an essential part of the related coupling detector;
[0048] [0048]FIG. 23 is an explanatory view showing an essential part of the related coupling detector in an initial state of coupling;
[0049] [0049]FIG. 24 is an explanatory view showing the essential part of the related coupling detector in a state on the way of the coupling; and
[0050] [0050]FIG. 25 is an explanatory view showing the essential part of the related coupling detector in a completely coupled state.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0051] Now, one preferred embodiment of the present invention will be described referring to the accompanying drawings.
[0052] In FIG. 1, a connector 1 to be employed in a wiring system for an air bag or the like in a motor vehicle, for example, includes a male connector 2 having a slider 4 made of synthetic resin and acting as a mechanical coupling detector, and a female connector 3 having a pair of abutting projections 5 adapted to be pressed by the slider 4 .
[0053] The male connector 2 includes a male connector housing 6 made of synthetic resin and having a hood portion 7 , and a plurality of female terminals 9 (see FIG. 4) inserted and locked in a plurality of terminal chambers 8 in the male connector housing 6 . The female connector 3 includes a female connector housing 10 made of synthetic resin and having a connector engaging room 11 , a plurality of male terminals 12 (see FIG. 4) inserted from a back of the female connector housing 10 and locked, and a short-circuiting metal piece 43 (see FIG. 3) for establishing a short circuit between the male terminals 12 as an electrical coupling detector. The male connector housing 6 is further provided with an insulating piece 47 (see FIG. 4) which is the counterpart of the electrical coupling detector.
[0054] To describe more specifically, a rectangular opening 14 is formed in an upper wall 13 of the hood portion 7 of the male connector 2 . The slider 4 is inserted into an inner space 15 (see FIG. 2) of the opening 14 from a front opening 16 (see FIG. 4) so as to slide in a longitudinal direction thereof. Further, a pair of spring holders 17 (see FIG. 5) are formed on both sides of a backward end of the opening 14 . Helical compression springs (resilient members) 18 (see FIG. 2) are respectively mounted to the spring holders 17 through the front opening 16 (see FIG. 4).
[0055] On the other hand, in the female connector housing 10 , there are formed the above described pair of the abutting projections 5 in parallel, at an intermediate position in a longitudinal direction of its upper wall 19 . Further, a lock projection 20 for the male connector 2 is provided behind the abutting projections 5 , at a center part in a lateral direction of the upper wall 19 . Each of the abutting projections 5 is provided with a vertical abutting face 5 a on its forward side and an inclined face 5 b on its backward side. The lock projection 20 is provided with an inclined face 20 a on its forward side and a vertical locking face 20 b on its backward side. Guide ribs 21 for positioning the male connector 2 are respectively provided outside of the abutting projections 5 in a lateral direction.
[0056] Referring to FIG. 2, the slider 4 has an upwardly directed protrusion 22 for retreating operation on its backward side, and a stop projection 23 (see FIG. 4) formed on a lower side of the protrusion 22 . The slider 4 also has, at its intermediate area, a C-shaped flexible abutting arm 24 . On both sides of a front end of the abutting arm 24 , there are provided downwardly directed abutting projections 25 (see FIG. 4). A base end of the abutting arm 24 is located inside a rear step 26 , and forward ends of the helical springs 18 are adapted to be abutted against the rear step 26 .
[0057] A pair of first guide slopes 27 (see FIG. 4) are formed on a forward side of the slider 4 . Further, a second guide slope 28 is formed inside and forward of the pair of the first guide slopes 27 . Both the guide slopes 27 , 28 are inclined downwardly in a backward direction. An angle of inclination of the second guide slope 28 is larger than that of the first guide slopes 27 .
[0058] On the other hand, there are formed on a lower face of the slider 4 , a pair of guide grooves (not shown) extending from its forward end to the above described abutting projections 25 (see FIG. 4). The abutting projections 5 of the female connector housing 10 are adapted to enter into these guide grooves. There are further provided stop projections 30 for preventing a forward withdrawal, on both sides of the intermediate area of the slider 4 .
[0059] As shown in FIG. 4, the lock projection 20 of the female connector housing 10 is formed so as to be opposed to a downwardly directed lock projection 29 of the male connector housing 6 .
[0060] The male connector 2 has an inner housing 32 provided with a front holder 31 , in a lower part inside the hood portion 7 . There are locked, inside the inner housing 32 , the aforesaid female terminals 9 provided with electric wires 33 . Waterproof rubber plugs 34 are inserted over the electric wires 33 , and a gasket 35 is mounted around the inner housing 32 . There is also provided in an upper part inside the hood portion 7 , the slider 4 so as to slide in a longitudinal direction (in an engaging/disengaging direction of the connector).
[0061] The slider 4 is urged in a forward direction (in an engaging direction of the connector) by the helical springs 18 (see FIG. 2). The stop projection 23 is formed with a vertical abutting face 23 a on its forward side and an inclined face 23 b on its backward side. The inclined face 23 b is formed for the purpose of smoothly riding over the stop and guide projection 36 which belongs to the hood portion 7 , when the slider 4 is mounted to the hood portion 7 . The guide projection 36 is provided so as to be directed upwardly, at an intermediate position in a longitudinal direction of a horizontal intermediate wall 37 in the hood portion 7 , and formed with an inclined face 36 a on its forward side and an abutting face 36 b on its backward side. The above described inner space 15 is provided above the intermediate wall 37 . Moreover, a forward half of the intermediate wall 37 is largely cut out, and inside the cutout portion, there is provided a flexible lock arm 38 (see FIG. 6) integrally formed with the intermediate wall 37 and extending forwardly.
[0062] The lock arm 38 has a downwardly directed lock projection 29 and an upwardly directed abutting projection 39 at its distal end portion. The lock arm 38 also has a pair of contact projections 40 for unlocking the lock, on both sides of its distal end portion. The lock projection 29 is formed with an inclined face 29 a on its forward side, and a locking face 29 b which is vertical or slightly inclined forwardly, on its backward side. The abutting projection 39 is formed with a backwardly and downwardly inclined face 39 a on its upper face. Each of the contact projections 40 is formed with a forwardly and upwardly inclined face 40 a on its lower face. The distal end portion of the lock arm 38 is adapted to be located at substantially half way between a forward end of the hood portion 7 and a forward end of the inner housing 32 .
[0063] There is formed an abutting wall 41 in a forward area of the abutting arm 24 of the slider 4 . There are further formed, forward of the abutting wall 41 , the aforesaid first guide slopes 27 , and still forward of the first guide slopes 27 , the aforesaid second guide slope 28 . Each of the abutting projections 25 of the slider 4 is formed with a vertical abutting face 25 a on its forward side and an inclined face 25 b on its backward side.
[0064] In a state where the stop projection 23 is abutted against the guide projection 36 , the abutting projections 25 are positioned in the rear of the lock projection 29 on both sides of the lock arm 38 . Lower ends of the abutting projections 25 are made flush with a lower face of the lock arm 38 . On one hand, the abutting wall 41 is formed substantially in a wedge-like shape in cross section having on its lower face a backwardly and downwardly inclined face 41 a which is adapted to come into contact with the abutting projection 39 of the lock arm 38 . On the other hand, the first guide slopes 27 are positioned in an opposed relation to a forward part of the contact projections 40 of the lock arm 38 , while the second guide slope 28 is positioned diagonally upward of the locking projection 29 in an opposed relation to the forward end of the lock arm 38 .
[0065] The insulating piece 47 of the male connector housing 6 is formed as a portion for canceling the short circuit between the male terminals 12 which have been established by the short-circuiting metal piece 43 , as shown in FIGS. 5 and 6. Moreover, the insulating piece 47 is formed in two steps consisting of a short circuit canceller 48 at a lower position and an auxiliary canceller 49 at an upper position. The steps are provided in a plurality of rows corresponding to steps of the short-circuiting metal piece 43 (see FIG. 4) which will be described below.
[0066] Referring back to FIG. 4, backward half portions of the male terminals 12 are respectively contained in the terminal chambers which are defined by front holders 42 of the female connector housing 10 . A tab portion 12 a of each of the terminals 12 in its forward half is arranged so as to project into the connector engaging room 11 . The terminals 12 are short-circuited by the conductive short-circuiting metal piece 43 . Waterproof rubber plugs 45 are respectively inserted over electrical wires 44 which are press-fitted to the terminals 12 . The female connector housing 10 is adapted to be fixed to a vehicle body, equipment or the like (not shown) by a fixed arm 46 provided in its lower part.
[0067] The short-circuiting metal piece 43 is contained in a chamber 50 (see FIGS. 7 and 8) which is formed in the female connector housing 10 . As shown in FIGS. 9A through 9C, the short-circuiting metal piece 43 includes a plurality of elastic arms 51 . These elastic arms 51 are arranged so as to correspond to the male terminals 12 (see FIG. 4). Each of the elastic arms 51 is divided into a short-circuiting piece 52 and an auxiliary piece 53 at its distal end, adapted to move together, which are respectively formed in a substantially V-shape. The short-circuiting piece 52 is formed so as to be positioned at a lower position than the auxiliary piece 53 (see FIG. 10). Reference numeral 54 designates a push-in wall to be used when the short-circuiting metal piece 43 is received in the chamber 50 (see FIGS. 7 and 8), Distal ends of the short-circuiting piece 52 and the auxiliary piece 53 are positioned inward of the push-in wall 54 so as to be protected when the short-circuiting metal piece 43 is received.
[0068] In the above described structure, operation of the above described connector 1 will be explained referring to FIGS. 11 to 20 .
[0069] In FIGS. 11A and 11B, when the male connector 2 and the female connector 3 are initially engaged with each other as the first step, the abutting projections 5 of the female connector 3 start to be abutted against the abutting projections 25 of the abutting arm 24 in the slider 4 . In this state, the tab portions 12 a of the male terminals 12 are not yet in contact with the electrical contact portions 9 a of the male terminals 9 , and there exists a large clearance L between a bottom of the connector engaging room 11 and a forward end of the inner housing 32 .
[0070] Moreover, the slider 4 is in a state urged forward (in the engaging direction of the connector) by the helical springs 18 . The helical springs 18 are remained pre-compressed, and are not deformed. Further, the stop projections 30 on both sides of the slider 4 are abutted against stop projections 46 of the male connector housing 6 , and at the same time, the stop projection 23 on the backward side is abutted against the guide projection 36 . A position of the forward end of the slider 4 is thus defined.
[0071] Then, as the abutting projections 5 of the female connector 3 push the abutting projections 25 of the slider 4 , as shown in FIGS. 12A and 12B, the slider 4 retreats while compressing the helical springs 18 . On this occasion, the lock projection 20 of the female connector 3 is abutted against the lock projection 29 of the lock arm 38 in the male connector 2 . At the same time, the first guide slopes 27 of the slider 4 come into contact with the contact projections 40 of the lock arm 38 . Then, the contact projections 40 ascend along the first guide slopes 27 , and accordingly, the lock arm 38 is flexed upwardly. At the same time, the male terminals 12 come into contact with the female terminals 9 .
[0072] As the next step, when the slider 4 has retreated as shown in FIGS. 13A and 13B, the lock projection 20 of the lock arm 38 slides along the second guide slope 28 upwardly to further flex the lock arm 38 in an upward direction. Then, the lock projection 29 of the lock arm 38 will pass over an upper face of the lock projection 20 of the female connector 3 to be positioned at a diagonally upward position forward of the lock projection 20 .
[0073] When the contact projections 40 ascend along the first guide slopes 27 , the lock projection 29 comes into contact with the second guide slope 28 . With this movement, the lock arm 38 is largely flexed in two stages. When the abutting projections 25 of the slider 4 slide along the guide projection 36 of the male connector 2 , the abutting arm 24 is accordingly flexed upwardly, and thus, the contact between the abutting projections 25 and the abutting projections 5 of the female connector 3 will be disengaged.
[0074] In the state as shown in FIGS. 13A and 13B, both the connectors 2 and 3 have been perfectly coupled (plenary engagement) with no clearance, and both the terminals 9 and 12 have been in perfect contact with each other. Just before the plenary engagement, the insulating piece 47 approaches near the elastic arms 51 of the short-circuiting metal piece 43 which has short-circuited the male terminals 12 , as shown in FIG. 14. When the insulating piece 47 and the elastic arms 51 have come into contact with each other as shown in FIG. 15, the short circuit cancellers 48 of the insulating piece 47 push the short-circuiting pieces 52 of the elastic arms 51 upward thereby to cancel the short circuit as shown in FIG. 16. The auxiliary pieces 53 of the elastic arms 51 move upward together with the short-circuiting pieces 52 , and the auxiliary cancellers 49 of the insulating piece 47 enter under the auxiliary pieces 53 .
[0075] Even though the short circuit cancellers 48 of the insulating piece 47 have happened to be deformed or broken due to some factor, the auxiliary cancellers 49 of the insulating piece 47 come into contact with the auxiliary pieces 53 of the elastic arms 51 to push them up, thereby to cancel the short circuit between the short-circuiting pieces 52 which move upward together with the auxiliary pieces 53 and the male terminals 12 , so that reliability in electrical detection of the coupling will be enhanced.
[0076] Further in succession as shown in FIGS. 17A and 17B, when the contacts between both the abutting projections 5 and 26 have been disengaged, and the slider 4 has been pushed back forward by biasing forces of the helical springs 18 , the initial state as shown in FIG. 4 will be restored. On this occasion, the abutting projections 25 of the slider 4 ride over the abutting projections 5 of the male connector 3 , and move forward. At the same time, as the second guide slope 28 moves forward integrally with the slider 4 , the contact between the lock projection 29 of the lock arm 38 and the second guide slope 28 will be disengaged, and the lock arm 38 will be elastically restored into a horizontal direction, allowing the lock projection 29 to be locked with the lock projection 20 in the female connector 3 . In short, respective locking faces 20 b , 29 b of both the lock projections 29 and 20 come into contact with each other in an opposed relation, and thus, both the connectors 2 and 3 are locked to each other.
[0077] When the abutting wall 41 of the slider 4 is abutted against the inclined face 39 a in the upper part of the abutting projection 39 , flexure of the lock arm 38 will be restrained. Particularly, when the backwardly and downwardly inclined faces 39 a , 41 a respectively of the abutting wall 41 and the abutting projection 39 have securely come into contact with no clearance, unintentional disengagement of the lock will be reliably prevented. This is only because the slider 4 is urged forward by the helical springs 18 , and with the urging force, the inclined face 41 a of the abutting wall 41 is pressed against the inclined face 39 a of the abutting projection 39 .
[0078] By the way, in case where an operator has stopped to couple the connectors, on a half way of coupling the connector 1 as shown in FIGS. 12A and 12B, the female connector 3 is pushed out from the Male connector 2 by compression forces of the helical springs 18 , since the abutting projections 25 of the slider 4 are in contact with the abutting projections 5 of the female connector 3 . In this manner, an incomplete coupling of the connector 1 will be detected. The situation is also the same in the state of FIGS. 13A and 13B in which the lock is not yet completed. The situation is also the same in the process as shown in FIGS. 12A through 13B. In case where the operator has interrupted the coupling, the incomplete coupling of the connector 1 will be electrically detected similarly, because the short circuit between the male terminals 12 has not been cancelled.
[0079] Further, because the lock arm 38 is lifted along the first guide slopes 27 in the process in FIGS. 12A through 13B, allowing the contact between both the lock projections 20 and 29 to be disengaged, frictional resistance will be decreased, and the female connector 3 will be smoothly and reliably pushed out by the forces of the helical springs 18 .
[0080] Now, disengagement of the connectors 2 and 3 from the coupled state of the connector in FIGS. 17A and 17B will be explained. When the slider 4 is allowed to retreat by pulling the operating protrusion 22 of the slider 4 backward (in a disengaging direction of the connector) by a finger in a direction of an arrow 1 , as shown in FIGS. 18A and 18B, the first guide slopes 27 of the slider 4 slide along the contact projections 40 of the lock arm 38 . At the same time, the inclined faces 25 b on the backward side of the abutting projections 25 of the slider 4 slide along the backwardly inclined faces 5 b of the abutting projections 6 of the female connector 3 .
[0081] Then, when the lock projection 29 of the lock arm 38 is pushed upward by the second guide slope 28 of the slider 4 as shown in FIGS. 19A and 19B, the lock arm 38 will be largely flexed upward, and the abutting projections 25 of the abutting arm 24 will ride over the abutting projections 5 of the female connector 3 . Both the tock projections 20 and 29 will move apart in a vertical direction, and thus, the connectors 2 and 3 will be disengaged from the locked state. The operating protrusion 22 of the slider 4 remains pulled backward by the finger.
[0082] Then, by pulling both the connectors 2 and 3 in the disengaging direction as shown in FIGS. 20A and 20B, the connectors 2 and 3 will be disengaged from each other, and the connection between both the terminals 9 and 12 will be disengaged. The slider 4 will be restored to the forward position by the urging forces of the helical springs 18 , when the finger is disengaged from the protrusion 22 . The insulating piece 47 is also disengaged, allowing the short-circuiting metal piece 43 to establish the short circuit between the male terminals 12 .
[0083] Besides, it is apparent that various modifications of the present invention can be made in a scope where a gist of the present invention is not changed. | A conductive member is provided in a first connector together with a plurality of terminal fittings. The conductive member includes elastic arms associated with the respective terminal fittings. Each elastic arm is divided into a first conductive piece and a second conductive piece which are moved together. The first conductive piece is brought into contact with the terminal fitting when the first connector and the second connector are disengaged. The second conductive piece is away from the terminal fitting when the first connector and the second connector are disengaged. Insulative members are provided in the second connector so as to be associated with the respective elastic arms. Each insulative member includes a first insulative piece and a second insulative piece. The first insulative piece is inserted between the terminal fitting and the first conductive piece when the first connector and the second connector are engaged. The second insulative piece moves the second conductive piece in a direction away from the terminal fitting when the first connector and the second connector are engaged. | 7 |
FIELD OF THE INVENTION
The present invention relates to a vortex pump wherein an impeller is housed within an impeller chamber and a vortex chamber is generally a free space.
BACKGROUND OF THE INVENTION
A vortex pump is usually employed for pumping liquids containing a substantial amount of foreign matter such as solids and/or fibriform substances. This kind of foreign matter causes clogging of pumps under operation. Therefore, in the pumps of prior art, an impeller is generally housed within a pocket or a recessed impeller chamber and a vortex chamber is arranged to be generally free of the rotating elements, i.e. the impeller.
However, such pumps of prior art are not satisfactory with respect to the pump efficiency and easiness of releasing air from the impeller chamber, etc. If it is intended to solve these drawbacks by extending the impeller to the vortex chamber, there would be the problem of blocking or clogging of the pump.
SUMMARY OF THE INVENTION
Accordingly, it has been desired to improve pump efficiency in vortex pumps without causing the drawbacks referred to above.
Therefore, it is an object of the present invention to provide an improved vortex pump having an improved pump efficiency and the capability of admitting and passing relatively large pieces of foreign matter without causing clogging of the pump.
This object is accomplished according to the present invention wherein some of the impeller blades are made wider in their axial width so that there are at least two groups of impeller blades, one being longer in the axial width than the other so that the wider blades partially extend into the vortex chamber and the shorter blades are disposed wholly within the recessed impeller chamber.
The further objects and advantages of the present invention will become clear when the detailed description is reviewed in conjunction with the accompanying drawings, a brief explanation of which is summarized below.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view, partially in section, of a vortex pump of the prior art;
FIG. 2 is a cross sectional view of a pump section according to the present invention;
FIG. 3 shows an impeller of FIG. 2 as viewed along line III--III in FIG. 2;
FIG. 4 schematically illustrates an exploded view of a fractional part of the impeller according to the present invention; and
FIG. 5 is a schematic illustration of characteristic curves for comparing the present invention and prior art.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Before describing the present invention, it might be convenient to briefly explain the prior art and an example of the prior art pump is illustrated in FIG. 1.
In this FIG. 1, an example of a vortex pump of prior art used as a submersible pump is shown wherein 1 designates a pump casing which is coupled with a motor 3' through an intermediate casing 2'. An impeller 5' is mounted at the tip end of a motor shaft 4' so as to be rotated by the motor 3'.
The casing 1 comprises an impeller chamber 6', a vortex chamber 7' and a supporting leg 8'. The vortex chamber 7' is provided with a suction opening 10' and communication with the impeller chamber 6' at the portion opposite the opening 10', the motor shaft 4', the impeller chamber 6' and the suction opening 10' being aligned on the central axis 9'.
The impeller 5' includes a main shroud or a main plate 12' and a plurality of blades 13'. In this pump, in order to prevent the pump operation from clogging by the foreign matter, the dimensional relationship of the portions pertaining to the flow of liquids containing foreign matter is considered as preferably being
D's=C'=B'v=D'd
wherein the meaning of the respective reference characters is noted below.
D's: the diameter of the suction opening 10',
C': the distance between a tip edge 14' of the blade 13' and an internal surface 15 of the wall of the vortex chamber 7' having the suction opening 10' (hereinafter simply referred to as the axial gap of the blade tip),
B'v: the axial width of the vortex chamber 7', and
D'd: the diameter of a discharge opening 11'.
The above relationship is generally to be recommended; however, in some instances, D's may be arranged to be larger than the others, namely C', B'v and D'd, in order to avoid loss at the suction opening 10' so that
L's=C'=B'v=D'd
wherein L's is the height from the bottom of the water to the lower surface of the suction opening 10'.
At any rate, the relationship
C'=B'v
is maintained so that the impeller blades 13 do not extend into the vortex chamber 7' and are housed within the space of the impeller chamber 6'.
As briefly touched upon in the background explanation, in the pump of prior art such as illustrated in FIG. 1, the following drawbacks are observed. That is:
(1) The Q-H characteristic feature is not sufficient and the pump efficiency is low.
In the vortex pump illustrated in FIG. 1, fluid in the vortex chamber is not directly caused to flow by the impeller blades 13' and it is a vortex flow induced along the surfaces of the blades which lets the fluid flow.
Therefore, the Q-H characteristic feature is degraded thus lowering pump efficiency.
(2) Releasing of air lock is not easy.
When the operation of the pump is stopped, air mixed or contained in the liquid, separates from the liquid and stays in the upper portion of the impeller chamber 6'. Upon initiation of the operation of the pump, the air thus dwelling at the upper portion of the impeller chamber 6' is not easily drawn or mixed into the liquid so that the air tends to remain and to cause an air lock. In order to prevent such an air lock, a vent hole 16' is provided; however, the size of the vent hole is generally small and, if highly concentrated liquid is handled by the pump, it is not easy to have the trapped air escape through the vent hole 16'.
(3) If it is intended to extend the blades into the vortex chamber 17' so as to obviate the drawbacks referred to in (1) and (2) above, the dimensional limit for allowing foreign matter is made smaller thereby increasing the possibility of clogging. The present invention effectively solves the drawbacks above which will be explained hereunder.
Referring now to FIG. 2, a cross sectional view of a pump casing portion according to the present invention is illustrated wherein the same references as those in FIG. 1 are employed excluding prime therefrom in each case. These references are to be regarded as equivalent to those in FIG. 1 unless otherwise specifically noted.
An impeller 5 is of an open type and comprises a main plate 12 and two groups of impeller blades, namely blades 13a and blades 13b. The blades 13a and 13b are arranged so that the width (Bb) of the blades 13b measured in the axial direction is larger than the width (Ba) of the blades 13a in the axial direction. (For convenience, the blades 13a are referred to as narrow blades and the blades 13b are referred to as wide blades.) That is, the following relationship is to be met.
Bb>Ba
The blades 13a do not extend into the vortex chamber 7 and the gap or distance Ca between the open end edge 14a of the narrow blade 13a and the opposing surface 15 of the wall of the vortex chamber 7 is made equal to the axial width (Bv) of the vortex chamber. That is:
Ca=Bv.
On the other hand, the wide blades 13b are extended in the axial direction so that the open end edge 14b of the respective blades protrude into the vortex chamber 7 by a dimension P.
Therefore, the following relationship is established.
Cb<Bv
Cb<Ca
wherein Cb is the distance between the open end edge 14b and the surface 15.
The plan view of the blades 13a and 13b is shown in FIG. 3. In this embodiment, the number of blades is six and the six blades are disposed equiangularly with each other with respect to the center axis, the number of the wide blades 13b being two and the number of the narrow blades 13a being four whereby the wide blades 13b are positioned so as to divide the circumference to the impeller into two.
The total number of the blades should not be a prime number from the viewpoint of the dynamic balance and hydraulic balance of the impeller and is arranged to be an integral number multiplication of a certain number "n" wherein the circumference of the impeller is equally divided by "n" and the wide blade is disposed as every "n"th blade in the circumferencial direction. As the number "n", any number may be selected, for example as follows:
______________________________________n total number of blades number of wide blades______________________________________2 4 2 6 3 8 4 10 5 12 63 6 2 9 3 12 44 8 2 12 3______________________________________
However, the actual total number of blades is preferably selected as ten or less from the viewpoints of manufacturing convenience.
Each of the open end edges 14a and 14b of the blades comprises a parallel portion 18a, 18b parallel to the main plate 12 and a slanted portion 19a, 19b inclined relative to the main plate 12, respectively. The radial length (Ta) of the parallel portion 18a is preferably made equal to the radial length (Tb) of the parallel portion 18b whereby the portion 19a is disposed at a smaller angle relative to the main plate 12 than the portion 19b. However, Ta and Tb may be different length but the inclined angle of the slanted portion 19a is preferably smaller than that of the slanted portion 19b. The angle of such inclination is preferably 45° or less for the narrow blade 13a and 55° or less for the wide blade 18b.
Also the relationship between Ba and Bb is preferably given by the following equation.
Bb=(1.2-2)Ba
Regarding the dimension of P, which is the distance by which the blades 13b protrude into the vortex chamber 7, it is given the following relationship relative to the axial width Bv of the vortex chamber 7, that is:
P=(0.06-0.5)Bv.
The following relationship might be more preferable.
P=(0.1-0.5)Bv
Several factors or values for the blades are determined as follows.
For the wide blades 13b, the number thereof, the blade axial width Bb and the configuration of the open end edge 14b, (i.e. the length (Tb) of the parallel portion 18b and the inclination angle of the slanted portion 19b, etc.) are selected on the following basis, assuming that a sphere having a diameter D 1 equivalent to the gap Ca is not to be clogged, during the operation of the pump, in the passage from the suction opening 10 through the vortex chamber 7 to the discharge opening 11. If all of the blades are formed having the width Bb, respectively, only a sphere having a diameter D 2 or less is allowed to pass through the passage.
At the region near the central axis of the impeller 5, the space between the adjacent blades becomes narrower so that the width of each of the blades is made narrower to provide a slanted portion 19a or 19b and the slanted portion is merged to the main plate 12 with an inclined angle.
A part of the impeller blades is schematically illustrated in FIG. 4 in a developed condition to show the relationship between the dimensions concerned, such as Ca, Cb, D 1 , D 2 , Ba and Bb wherein, for convenience, each blade is illustrated as having a flat shape. However, in FIG. 3, the blades 13a and 13b are illustrated as curved blades. The cross hatched portions in FIG. 3 are the parallel portions 18b of the wide blades 13b which are, as viewed in FIG. 3, higher than the parallel portions 18a of the narrow blades 13a. The blade width Bb and the shape of the wide blades 13b are determined so that a sphere having the diameter D 1 (=Ca) which has passed through the suction opening 10 into the vortex chamber 7 may come into collision with the wide blade 13b but it may not be obstructed thereby but will freely pass the flowing space between the wide blades 13b to the discharge opening 11 from where it is discharged outwardly.
Whilst the two groups of blades are illustrated and explained with respect to the embodiments shown in FIGS. 2, 3 and 4, another group of blades may be provided. For example, a group of blades each having an intermediate width between the width Bb and Ba may be provided. Also, the narrow blades 13a may be axially extended into the vortex chamber 7, at the same time, of course, keeping the relationship of
Bb>Ba.
The intake side edge of the suction opening 10 directly opening to the liquid is preferably arranged to be sharp. If this edge is rounded so as to reduce the resistance of the liquid flow, the shaft power increases as the discharge increases beyond the specified discharge and even induces an overloaded condition of the pump when the discharge increases beyond a certain value. Should a conduit be connected to the suction opening, the same situation as above will be caused regarding the shaft power. If the intake side edge of the suction opening 10 is sharp, the shaft power reaches the maximum value at a certain point beyond the specified discharge whereby such pump exhibits an operation free from overloading for all the operating conditions with respect to the limit-load characteristic. This is because the suction opening 10 having the sharp edge directly opening to the liquid effects to cause contraction of the flow in a manner somewhat similar to the situation in an orifice whereby flow rate through the opening is limited.
The advantages of the present invention may be summarized as follows:
(a) Although some of the blades are extended into the vortex chamber 7, the size limits of the foreign matter allowed to pass through the pump are not reduced and the same size of matter as previously allowed to pass when all the blades are the same size as the blades 13a is still allowed to pass through.
(b) The liquid in the vortex chamber is directly driven by the portions of the wide blades 13b, the loss of the pump is reduced, and the Q-H characteristics and the efficiency of the pump are improved.
As an example of such improvement, comparison between the present invention and prior art is illustrated in FIG. 5. The curves of this FIG. 5 were obtained through experiments conducted by using a prior art pump and a pump according to the present invention.
Prior Art:
Impeller Diameter: 269 m/m
Blade Width: 25 m/m
Outlet Angle (β 2 ): 45°
Number of Blades: 8
Present Invention:
Impeller Diameter: 269 m/m
Outlet Angle (β 2 ): 45°
Number of Blades: 8
Wide Blade (13b): 2
Narrow Blade (13a): 6
Blade Width
Wide Blade (Bb): 60 m/m
Narrow Blade (Ba): 25 m/m
Protruding Dimension (P): 35 m/m
The same pump casing was used for both tests, having an opening size of 65 m/m and a discharge opening size of 65 m/m. Axial width of the vortex chamber (Ba) was 65 m/m.
(c) Because of the fact that the portions of the wide blades 13b extend into the vortex chamber 7 directly act on the liquid to induce the vortex flow strongly, air trapped in the impeller chamber 6 is dragged into the vortex flow so as to be easily discharged out of the pump and, thus, the problem of air-locking is solved.
(d) Because the inclined angle of the slanted portion 18a relative to the main plate 12 is smaller than that of the slanted portion 18b, the foreign matter contacted by the wide blades 13b may escape towards the slanted portion 18a of the narrow blades, thus preventing the pump from clogging. Also, the length Tb is made substantially equal to Ta so that the effect of the wide blades acting on the liquid is substantial thereby contributing an improvement in the pump characteristics and the efficiency of discharging the trapped air is also enhanced.
(e) Since the slanted portions 18a or 18b are provided, entanglement of elongated foreign items such as fibrous materials is effectively prevented.
The present invention has been explained in detail referring to the particular embodiment; however, the present invention is not limited to that which has been explained and it may be modified or changed by those skilled in the art within the sprit and scope of the present invention as defined in claims appended. | A vortex pump is provided wherein an impeller is of an open type and plural blades are grouped into two or more groups, the axial width of each group of blades being different from the others so that the blades belonging to a certain group extend into a vortex chamber so as to directly drive the liquid in the vortex chamber while relatively large pieces of foreign matter are permitted to pass through the pump. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation application of U.S. patent application Ser. No. 11/049,213 filed on Feb. 2, 2005 which claims the benefit of U.S. Provisional Application No. 60/545,379, filed on Feb. 18, 2004. The disclosure of the above applications is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] This system relates to a method and apparatus for electrolysis of water and, more particularly, to photoelectrochemical (PEC) devices and photoelectrolysis of water to produce hydrogen.
BACKGROUND OF THE INVENTION
[0003] Currently the major process by which hydrogen is produced is by the steam reforming of methane. Another means of making hydrogen is by the electrolysis of water. The electricity required for electrolysis is mainly derived from the electric power grid, and the predominant source of grid electricity, combustion of fossil fuels, generates emissions, such as nitrogen oxides and particulate matter, as well as carbon dioxide. One way to eliminate such emissions is to use solar generated electricity to electrolyze water to make hydrogen. Presently, efforts are directed toward improving the efficiency, durability, and cost of the solar powered hydrogen production processes.
[0004] However, systems consisting of solar cells to make electricity together with electrolyzers to dissociate water into hydrogen and oxygen, as they exist today, cannot produce hydrogen as cheaply as the steam reforming of methane. Several projects have attempted to produce hydrogen gas to supply vehicle-fueling stations by using electricity from photovoltaic panels and commercially available electrolyzers to split water. These projects proved unsatisfactory and were usually short-lived due to the low efficiency and high cost of the combined technology, which only converted about 2%-6% of the solar energy to hydrogen fuel energy, thus, greatly increasing capital costs, the resulting hydrogen fuel cost (at least $11 per kilogram of hydrogen), and the large area covered by the system.
SUMMARY OF THE INVENTION
[0005] To overcome the disadvantages of the prior art, a method for designing and operating a solar hydrogen generator or solar powered electrolysis system having at least one photovoltaic (PV) module is provided. The system and method utilize at least one PV cell, supplying power to electrolyze water to produce hydrogen. The method uses the steps of determining the most desirable maximum power point voltage (E mpp ) for the PV module based on a predetermined relationship between actual operating voltage and actual operating current under load for the PV module and the most efficient operating voltage for the electrolysis system, electrolysis cell or electrolyzer unit (the electrodes and electrolyte used to split water). Next, the number of solar cells in series operating at the E mpp needed to achieve the most desirable E mpp of the entire PV module is determined. The most desirable E mpp is the desired voltage needed to split water into hydrogen and oxygen and satisfy voltage losses (the over-voltage and resistances) that is required to operate the electrolysis system and achieve the maximum efficiency for converting solar energy to hydrogen fuel energy. The terms PV cell and solar cell are used in the art and herein interchangeably. The term PV module refers to one or more cells. The term cluster is used interchangeably with the term module.
[0006] In another embodiment of the invention, a method for operating a solar powered electrolysis system having at least one photovoltaic (PV) module is disclosed. The system is made up of one or multiple individual solar cells connected in series, supplying power to an electrolysis system to electrolyze water to produce hydrogen. The method determines the most efficient actual operating voltage and actual operating current of the electrolysis system and matches them (making them as closely equal as possible) to the maximum power voltage E mpp and maximum power point current I mpp drawn from the PV module to operate the electrolysis process. In one aspect, the operating voltage (E oper ) of the solar powered electrolysis system is determined by testing or other means and should be matched as closely as possible to the maximum power point voltage of the PV module (E mpp ) based on a predetermined relationship between E mpp for each individual solar cell and E mpp for a PV module constructed from one or several solar cells in series. The number of cells in series (at their maximum power point under the load of the electrolysis system) needed to achieve the most efficient voltage to split water into hydrogen and oxygen and satisfy electrolysis system losses (over-voltage and resistances) is then determined.
[0007] In another embodiment, a method for operating a photoelectrolysis system having at least one photovoltaic (PV) solar cell or module of multiple solar cells connected in series or parallel circuits to an electrolysis system for supplying power to electrolyze water to produce hydrogen is provided. The number of PV cells in series to achieve a desired voltage to split water into hydrogen and oxygen and satisfy electrolysis system losses and resistance (the over-voltage) based on the maximum power point voltage of the PV system (module) is determined, based on a predetermined relationship between photoelectrolysis efficiency and operating voltage of the electrolysis system.
[0008] Another embodiment discloses a method for operating an electrolysis system having at least one photovoltaic (PV) cell, with two electrodes (the anode and cathode) both connected to the PV system to electrolyze water to produce hydrogen. Electrically conductive electrodes of catalytic materials or coating the surface of the electrodes with catalytic coatings to split water into hydrogen and oxygen and reduce electrolysis system losses and resistances (over-voltages) are sized based on the current and maximum power point voltage (E mpp ) of the PV and electrolysis systems. A maximum current density of the electrodes required for efficient operation based on a predetermined relationship between electrolysis efficiency and current density is determined. By convention, in electrolysis, the cathode is the electrode where reduction takes place and hydrogen is generated, and it is attached to the negative pole of the solar cell. The anode is the electrode where oxidation takes place and oxygen is generated, and it is attached to the positive pole of the solar cell.
[0009] In another embodiment, a method for operating a solar hydrogen generator or photoelectrolysis system is disclosed. Each solar PV module of the system has at least one solar cell and produces the optimum voltage for operating the electrolysis system to produce hydrogen. The PV module is connected to its own separate electrolysis circuit (consisting of an anode, cathode, and electrolyte solution) rather than connecting several PV modules in parallel to a single electrolysis circuit.
[0010] In another embodiment, a solar hydrogen generator or photoelectrolysis system having at least one photovoltaic (PV) module delivering 1.8 to 2.5 volts DC (E oper ) is disclosed. The PV module has a current density as low as possible, which must be less than 12 milliamps per cm 2 , a nickel-based cathode, and an anode comprising a ruthenium oxide layer or coating on a nickel-based electrode.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:
[0012] FIG. 1 is a prior art photovoltaic-electrolyzer hydrogen generation system made from a prior art photovoltaic power supply, electrolyzer, and other hardware;
[0013] FIG. 2 is a simplified and optimized design for a photovoltaic-electrolysis (PV electrolysis) system using solar cells with the optimum electrolysis potential connected in parallel to an alkaline electrolysis cell with low over potential electrodes—Ni cathode and Ni—RuO 2 anode according to the teachings of the present invention;
[0014] FIG. 3 shows measurement methods for PV-electrolysis parameters;
[0015] FIG. 4 is a graph depicting the effect of different anode materials on the PV-electrolysis efficiency (solar energy to hydrogen energy conversion efficiency);
[0016] FIG. 5 is a diagram depicting the effect of electrode current density on the electrolysis efficiency;
[0017] FIG. 6 is a diagram depicting the open circuit voltage (E oc ) of various numbers of crystalline silicon (c-Si) solar cells in series used to test the PV-electrolysis efficiency;
[0018] FIG. 7 is a diagram depicting electrolysis operating current (I oper ) measured in the PV-electrolysis tests with various numbers of c-Si solar cells in series;
[0019] FIG. 8 is a diagram depicting the efficiency of PV-electrolysis systems (the solar energy to hydrogen conversion efficiency) as a function of the number of c-Si solar cells in series;
[0020] FIG. 9 is a diagram depicting Eoc corresponding to the optimum efficiency of PV-electrolysis systems measured with a range of potentials from Connecticut Solar c-Si solar cells in series with a high efficiency electrolysis cell;
[0021] FIG. 10 is a diagram depicting current and power versus potential for a photovoltaic module. The current at the maximum power point (mpp) is identified;
[0022] FIG. 11 is a diagram depicting the optimum efficiency range for PV-electrolysis using Connecticut Solar c-Si solar cells wired in series. This figure also shows several other parameters including E oc , E mpp , and I oper as a function of the number of c-Si solar cells wired in series to an alkaline electrolysis cell with low over potential electrodes—Ni cathode and Ni—RuO 2 anode;
[0023] FIG. 12 is a photograph showing a-Si and c-Si solar modules and the tank reactor and electrodes used to optimize the efficiency of hydrogen production by PV-electrolysis;
[0024] FIG. 13 is a simplified and optimized design for a PV-electrolysis system using solar cells with the optimum electrolysis potential connected in series to an alkaline electrolysis cell with low over potential electrodes—Ni cathode and Ni—RuO 2 anode. Multiple PV-electrolysis systems as in FIG. 13 are also contemplated by the invention; and
[0025] FIG. 14 is diagram depicting a simplified and optimized design for a PV-electrolysis system as in FIG. 2 using solar cells with the optimum electrolysis potential connected in parallel to an alkaline electrolysis cell with low over potential electrodes—Ni cathode, Ni—RuO 2 anode; and showing detail of 6 cells in series per module.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0026] The system provides a practical, non-polluting technology for producing hydrogen fuel using photovoltaic semiconductor materials, an electrolyzer, and sunlight, to power fuel cell vehicles and stationary power generation at a cost competitive with other energy sources.
[0027] The system, which according to the teachings of the present invention, provides a more efficient solar powered PV-electrolysis system for hydrogen generation, was designed by systematically integrating the photovoltaic circuit and the electrolysis system and optimizing their efficiencies. The optimization process increased the conversion of solar energy to hydrogen fuel energy (the system efficiency) from about 2-6% estimated for prior art PV panel and electrolyzer systems to 7.2% for an optimized integrated system constructed using the same PV materials (crystalline or amorphous silicon). The PV circuit, PV voltage, electrode materials, electrode size, and electrolyte were all integrated and optimized to achieve the highest efficiency.
[0028] Costs for PV-electrolysis production of hydrogen fuel were estimated using standard cost analysis approaches. The increase in efficiency by the present system using the same PV material, means that the expenses for the PV modules needed to generate hydrogen for a fleet of fuel cell vehicles or to generate stationary electric power from non-polluting renewable hydrogen would decrease by about a factor of 3.5. The expenses are also reduced because the charge controller, batteries, and DC converter included in a prior art PV-electrolyzer system are all eliminated by the more efficient and simplified design of the current system. The overall reduction in capital cost due to optimization of PV-electrolysis is expected to be at least 75%. The estimated cost of hydrogen fuel generated by PV-electrolysis, which results mainly from capital costs, would be reduced from $11 per kg for the prior art system (see FIG. 1 ) to about $3 per kg. This decrease in production costs for non-polluting solar hydrogen can be expected to assist in building a future hydrogen economy to largely replace fossil fuel consumption. Any change to hydrogen fuel would eliminate the associated green house gas emissions and resulting global warming.
[0029] As shown in FIG. 1 , the prior art PV-electrolysis systems for solar hydrogen fuel production consisted of an array of photovoltaic modules made up of many solar cells connected in series to give a high voltage, a DC-DC converter, voltage controller, storage batteries, and an electrolyzer, usually consisting of platinum catalyzed electrodes, separated by a specialized membrane, and an aqueous alkaline electrolyte.
[0030] PV modules of an exemplary prior art system consist of 36 crystalline silicon (c-Si) solar cells connected in series to produce electricity with an open circuit potential of approximately 22 volts, when not operating under any load, and a potential of 18 volts at their maximum power point (E mpp ), when delivering their highest current under load to power processes such as electrolysis or charging batteries. These modules and voltages are usually designed specifically to charge battery systems and to power electric appliances either directly or through AC inverters and are not optimized to directly or indirectly power electrolysis cells. The 18-volt potential of the prior art PV panels is too high to efficiently generate hydrogen when connected directly to electrolysis cells (electrolyzer devices).
[0031] With general reference to FIG. 2 , an efficient electrolysis cell, which was used in the present system comprised a platinum (Pt) or nickel (Ni) cathode 30 and a catalyzed, ruthenium dioxide-coated nickel or titanium (Ni—RuO 2 or Ti—RuO 2 ) anode 32 immersed in 5 M potassium hydroxide solution 34 . Because these electrode materials catalyze the water splitting reactions, the resulting electrolysis cell 36 has low over potential and high efficiency. Thus, the electrolysis of water in an efficient electrolysis cell begins at about 1.6 volts DC, which includes 1.23 volts, the theoretical potential required to split water, and a minimal overpotential of 0.35 volts for the best catalyzed electrode systems. Traditionally, the most efficient potential for hydrogen production using a PV power source and commonly available electrolysis systems, is usually considerably higher than 1.6 volts due to the limited catalytic capability of most electrode materials, the resistances in the PV-electrolysis circuit including the electrolyte, and the resulting higher overpotential is about 0.5-1.2 volts. In practice, PV devices must usually supply an operating potential (E oper ) of about 1.8-2.5 volts measured between the anode and cathode when the PV system is connected to a high efficiency alkaline electrolysis cell.
[0032] The over potential represents electricity which does not go for useful solar energy conversion to fuel energy (electrolysis) but, instead, is converted to heat. The lower the E oper , at which electrolysis occurs, the more efficient the electrolysis cell, because the over potential and the energy wasted as heat formation is minimized.
[0033] Designing a PV module 38 that is integrated with the PV-electrolysis system so that it powers the water splitting reaction most efficiently is a key element in optimizing solar hydrogen production. It is necessary to optimize both the PV-electrolysis system 40 which powers electrolysis for hydrogen generation and the electrolysis cell or electrolyzer 36 so that the PV-electrolysis system voltage at its maximum power output (E mpp ) matches the optimum voltage for the electrolysis cell and, thus, can produce the highest current and highest hydrogen production efficiency. Thus, the most effective approach for optimizing solar powered PV-electrolysis for hydrogen production requires systematically integrating the photovoltaic circuit and the PV-electrolysis system and optimizing their efficiencies. The PV materials, PV circuit, PV voltage, electrode materials, electrode size, and electrolyte type and concentration must all be optimized and then combined to achieve the highest efficiency. Improving hydrogen production efficiency is a major method for reducing the cost of hydrogen fuel production. Simplifying the PV-electrolysis system by connecting the PV modules directly to the hydrogen and oxygen electrodes is another means of improving performance and reducing cost, which will be explained below.
[0034] The relationship of hydrogen generation efficiency to PV electrical generation efficiency and the efficiency of the electrolysis cell (electrolyte and electrodes) is given by Equation 1.
[0000] H 2 Generation Efficiency= PV Efficiency×Electrolysis Efficiency (Equation 1)
[0035] To optimize the generation of hydrogen from a PV-electrolysis system 40 , it is necessary to make several improvements in the prior art design shown in FIG. 1 : (1) the maximum power point potential (E mpp ) supplied by the PV-electrolysis system must match the characteristic operating potential (E oper ) required by the PV-electrolysis system, (2) the batteries, which are an inefficient means of energy storage, should be eliminated, and (3) any parts that increase resistance, voltage losses, and inefficiency in the PV-electrolysis circuit, including the voltage converter and charge controller should be eliminated as well. The circuit, according to the teachings of the present invention, with the unwanted parts removed, is shown in FIG. 2 . As shown in the example in FIG. 2 , the circuit connections of the solar cells 42 of the PV panel 44 have been redesigned by using solar modules with the best number of solar cells in series that give the correct E mpp of approximately 2.5 volts DC (ranging about 2 to 3 volts DC for catalyzed electrodes) to match the operating potential (E oper ) required by the PV-electrolysis system 40 . As shown in FIG. 2 , three (or more) of the 2.5 volt modules can be connected in parallel to the electrolysis cell to give a greater current and rate of hydrogen production. Any type of solar cells could be used in the optimization process, including but not limited to c-Si, a-Si, CuInSe 2 or, CdTe based solar cells, as long as the number and configuration of the solar cells gives the correct E mpp to match the best operating voltage for the PV-electrolysis system.
[0036] Because the 2.5 volt PV modules, shown connected in parallel in FIG. 2 , must have equal E mpp and I oper (a quality called voltage and current matching) for optimal performance and efficiency, a problem can arise if one or more of the modules is partially shaded from the sunlight during part of its operation or becomes defective due to age or damage (or for other reasons) and no longer makes the same E mpp and I oper as the other modules. If it is judged that this mismatching may happen, then each of the modules can be connected to a separate electrolysis cell (anode and cathode) rather than being connected in parallel to the same electrolysis cell as shown in FIG. 2 . Connecting each optimized PV module to a separate electrolysis circuit in this way could, thus, increase the efficiency of the entire solar hydrogen production system by preventing current mismatching. The increase in efficiency would depend upon the seriousness of the mismatching it avoids. The greatest benefit comes from connecting each individual PV module to a completely separate electrolysis cell with a separate anode and cathode in a separate electrolyte container insulated from any other electrolysis cell. At least, part of the maximum benefit could be obtained by connecting each PV module to a separate anode and cathode, but immersing more than one anode and cathode pair in the same container of electrolyte to save expense, in which case the mismatched PV modules would be only partially insulated from each other. See also FIG. 13 showing a module having several cells in an electrolysis system. Multiple electrolysis systems replicating that of FIG. 13 may optionally be used. Also, multiple electrode sets in a single container, each associated with a PV module are also contemplated.
[0037] The 2.5-volt modules, shown in FIG. 2 , are optionally made by redesigning a typical PV panel 44 . For example, some PV panels 44 have 36 crystalline solar cells in series. Each of these cells might have an inherent open circuit potential (E oc ) of 0.6 volt, and the entire PV panel might have an E oc of 21.6 volts. Each of these solar cells could have an E mpp of 0.41-0.5 volt, and several cells could be connected in series to make a solar module with the required optimum E mpp of 2 to 3 volts to power water electrolysis. For example, six solar cells (CT Solar, Putnam, Conn.) connected in series can give an E mpp of 2.46 volts (6×0.41=2.46), which matches the E oper requirement of an efficient electrolysis cell (1.8-2.5 volts) described above, as will be explained below in the experimental results section. FIG. 3 illustrates the methods used to measure the E oc , the short circuit current (I sc ), the operating potential during electrolysis (E oper ) and the operating current during electrolysis (I oper ), where the symbol V in a circuit indicates a voltmeter and A indicates an ammeter. E mpp of individual solar cells can be estimated from the E mpp of the PV module determined by the manufacturer and the number of cells in series (Equation 2).
[0000]
E
mpp
of
each
solar
cell
=
E
mpp
of
P
V
module
No
.
of
solar
in
series
(
Equation
2
)
[0038] The E mpp and efficiency of crystalline silicon PV cells are normally measured at standard test conditions which are 25° C. and 100 mW/cm 2 (one sun irradiance). However, E mpp and efficiency decrease with increasing temperature. This temperature coefficient effect, may be one of the reasons (along with the other sources of over potential of the electrolysis system) that the optimum E mpp of the PV modules (2.0-3.0 volts DC) for real world PV-electrolysis systems is significantly higher than the minimum potential for electrolysis (1.6 volts DC) in high efficiency electrolysis cells.
[0039] To optimize PV-electrolysis for hydrogen generation, it is necessary to determine the efficiency of converting solar energy to hydrogen fuel energy as a function of the electrode and PV characteristics, including the electrolysis efficiency (related to electrode over potentials) and the PV efficiency, potential, current, and resulting power generated when it is connected to the electrolysis cell. Experimentally, the efficiency of hydrogen generation from PV-electrolysis is determined by connecting the PV power source, irradiated with sunlight at a known intensity (usually one sun irradiance, which equals 100 mW/cm 2 ), to a high efficiency electrolysis cell or electrolyzer and measuring the electrolysis current I oper . Then, the efficiency is calculated using Equation 3.
[0000]
Efficiency
=
I
oper
(
mA
)
×
1.23
volts
P
V
area
(
cm
2
)
×
Solar
Irradiance
(
mW
/
cm
2
)
×
100
%
(
Equation
3
)
[0040] In optimization experiments for this embodiment, all the PV systems were connected to an electrolysis cell containing a Ni—RuO 2 anode and a Ni cathode, each with a surface area of 128 cm 2 , immersed in 450 mL of aqueous 5 M KOH solution. During electrolysis using PV solar cells with E mpp ranging from 1.5 to 16 volts DC (E oc of 1.8 volts to 20 volts) connected to these electrodes, the actual operating potential difference (E oper ) ranged from 1.5 to 3.3 volts.
[0041] It was determined experimentally that alkaline conditions are much less corrosive than acidic conditions for all the candidate materials used as electrodes, contacts, connectors, and in PV devices which would come in contact with the electrolyte. Chiefly, the encapsulation and insulation materials, including the plastics, Tefzel, Epoxy, and Acrylic, and the electrode materials, nickel, nickel coated with RuO 2 , platinum, and conductive glass coated with fluorine doped tin oxide (SnO 2 :F) were not etched or corroded after immersion for more than one month in concentrated potassium hydroxide (5 M KOH). It was also determined that maximum conductivity (approximately 0.55 Siemens/cm at 20° C.) in aqueous KOH solutions occurs at a concentration of 5 M (22-25% by weight). Thus, a 5 M KOH electrolyte solution was chosen for optimization of PV-electrolysis systems.
[0042] As shown in FIG. 4 , the efficiency of a range of electrode materials is shown which allows the optimization of the design of the electrolysis cell by minimizing the system overpotential (over-voltage). The type of anode, where oxygen gas is generated during electrolysis, was varied, because the anode has greater over potential than the cathode and its optimization is, therefore, more difficult. It was already known that nickel is a highly efficient and inexpensive material for the cathode, where hydrogen gas is evolved. Six candidate anodes were tested: nickel (Ni) and platinum (Pt), which are especially resistant to corrosion in alkaline electrolytes and have catalytic qualities for water splitting, Ni—RuO 2 or Ti—RuO 2 , nickel or titanium coated with ruthenium oxide, a known catalyst for oxygen electrodes, and two other relatively inexpensive and corrosion resistant conductive materials, glass coated with fluorine doped tin oxide (SnO 2 :F), a corrosion resistant transparent conductive oxide, and silver epoxy (Ag-epoxy), a metal polymer composite used as a sealant and adhesive. The most efficient anode material was found to be nickel-ruthenium oxide (probably Ni—RuO 2 ), which gave the highest conversion rate from solar energy to hydrogen (4.5%). It should be noted that the E oc (3.8 volts) of the PV solar cells used in the anode tests, two amorphous silicon triple junction solar cells (from Unisolar, Inc., Troy, Mich.) connected in series, approximately matched the optimum E oc range of 3.0-4.0 volts DC). Since the efficiency of the solar cells used in the anode tests for converting sunlight to electrical energy was rated at 6.9%, the efficiency of the electrolysis process even with the best anode material was 4.5%/6.9%×100%=65%. This calculation is derived from Equation 1. Thus, the operation of the optimized electrolysis cell under actual reported conditions was reduced from its estimated maximum efficiency level of approximately 80% to only 65% despite a relatively good match between the PV electrical output and the requirements of the electrolysis system.
[0043] The optimum area of the electrodes used in the electrolysis cell depends upon the effect of current density (J oper ) on electrolysis efficiency (see FIG. 5 ). The results of PV-electrolysis efficiency measurements at several current densities indicate that efficiency begins to decrease when J oper is greater than about 12 mA/cm 2 . There was no decrease in efficiency under electrolysis conditions used in the optimized PV-electrolysis devices constructed to demonstrate the current system (preferred embodiment), where the surface areas of the electrodes were approximately equal to that of the PV panel, which resulted in a current density of 6 mA/cm 2 or less.
[0044] The cathode (hydrogen electrode) with very good corrosion resistance and lifetime greater than 744 hours consisted of 25.4 micrometer thick nickel foil (99.9%, Strem, Inc).
[0045] The anode was prepared from the same nickel foil as the cathode and was coated with RuO 2 by a process using heat treatment at 350° C. The process sticks the ruthenium compound firmly onto the nickel and oxidizes the original RuCl 3 to form RuO 2 by reaction with the hot air in the oven. Ruthenium chloride, RuCl 3 (FW 207) with a mass of 1.04 g (0.005 moles), was dissolved in 25 mL of concentrated hydrochloric acid and subsequently diluted to 50 mL with deionized water to yield a 0.1 M solution. This solution was evaporated just to dryness in a fume hood on a hotplate with stirring. The resulting paste was dissolved in 25 mL of 2-propanol to yield a 0.02 M solution. Sheets of nickel foil were prepared and cleaned by first etching them mechanically with very fine sand or emory paper, then etching in 20% hydrochloric acid for 30 seconds, rinsing in deionized water, and air drying. The sheets were coated with the 0.2 M ruthenium chloride solution using a fine spray or brush and sintered in an electric oven at 350 degrees ° C. for 15 minutes. The coating was applied to both sides of each electrode in this way a total of 4 to 5 times, and the resulting electrode was then annealed in the oven at 350 degrees ° C. for 1 hour. Heating in air in the oven oxidized the ruthenium chloride to ruthenium dioxide (RuO 2 ) which produced a stable layer of RuO 2 approximately 2.3 micrometers thick. Then, the coated electrode was cooled, soaked in 5 M KOH solution at least 1 hour, and rinsed thoroughly with water to remove any excess unreacted RuO 2 . The total coating was approximately 0.1 mg RuO 2 /cm 2 . This process yields a stable catalyst coating on the electrode which does not come off during its use in alkaline electrolysis. The resulting electrode did not lose its coating or catalytic activity over extended use (>1000 hr) and was less expensive to make and more efficient than a similar RuO 2 coated titanium electrode.
[0046] The other major system which must be improved to optimize PV-electrolysis is the semiconductor PV module itself. Optimizing the PV module system requires that the PV voltage delivered under natural solar radiation match the most efficient voltage for operating the electrolysis cell (already optimized above). To determine the optimum E oc and E mpp required from a PV panel to produce the most hydrogen (the highest PV-electrolysis efficiency), various numbers of crystalline silicon solar cells (Connecticut Solar) with open circuit voltage E oc of 0.59 volts were connected in series to the optimized electrolysis cell, with a highly efficient Ni—RuO 2 anode and a Ni cathode, to measure the current through the electrolysis cell (I oper ) and calculate the hydrogen generation rate over a range of various numbers of solar cells, E oc , and E mpp (see FIGS. 6-9 ). The electrolysis operating current and potential were measured in an electrolysis cell with 128 cm 2 electrodes and 5 M KOH electrolyte as shown schematically in FIG. 3 , and the efficiency of solar energy conversion to hydrogen fuel energy was calculated using Equation 3. The efficiency results plotted versus the number of solar cells in series are presented in FIG. 8 . These results showed that the maximum efficiency occurred using six cells in series with a module having an E mpp of 2.5 volts and E oc of about 3.5 volts ( FIG. 9 ). It is envisioned that other PV solar cells such as triple junction thin layer amorphous silicon (a-Si), thin layer cadmium telluride (CdTe), thin layer copper indium diselenide (CuInSe 2 ), combined a-Si and c-Si photovoltaics, or others could be used in the same manner as the crystalline silicon (c-Si) cells in the above example.
[0047] Table 1 shows results that were obtained for the solar hydrogen generation systems obtained as described above using inexpensive silicon PV panels.
[0000] TABLE 1 Solar Hydrogen Generation Using Amorphous and Crystalline PV Materials Best H 2 Best Best Electric Gen. Electrolysis Gen. E oc E mpp Efficiency E oper Efficiency Efficiency Source Type (volts) (volts) (%)* (volts) (%) (%) Unisolar a-Si 3.8 2.7 6.9 2.1 65 4.5 CT Solar c-Si 3.5 2.5 10.9 2.0 66 7.2 *Based on the rated power of the original PV panel operating at its maximum power point
For the a-Si cells, which have an E mpp of ˜1.35 volts (E oc of ˜1.9 volts), two a-Si solar cells are connected in series to give an optimized voltage approximately equal to the optimized voltage from six c-Si solar cells in series (Table 1).
[0048] As shown by Table 1, the c-Si PV material from Connecticut Solar (Putnam, Conn.) gave the best hydrogen generation efficiency (7.2%) when optimized to deliver an E oc of 3.5 volts. The triple-junction a-Si solar cells were obtained from Uni-Pac 10 panels purchased from United Solar Systems Corporation of Troy, Mich. The a-Si solar cells gave a lower efficiency than the c-Si cells due to their inherently lower electrical generation efficiency. The operation of the electrolysis system was about equally efficient (65-66%) for both kinds of silicon-based solar cells. This result indicates that there was a fairly good match between the E mpp of the optimized PV system and the E oper of the optimized electrolysis system in each case. A number of c-Si solar cells from other sources gave similar optimization results (OK Solar, Shell Solar, and Sharp Solar).
[0049] The most efficient PV-electrolysis system made with the Connecticut Solar c-Si cells produced a current of 0.77 A for a 138 cm 2 module under standard test conditions (one sun of AM 1.5 global sunlight). This translates to a production rate of approximately 1.04 moles of hydrogen per hour for a 1.0 m 2 panel of optimized solar cells. This generation rate would require a PV array with an area of 36 m 2 (dimensions of 19.5 feet by 19.5 feet) to keep a fuel cell vehicle supplied with enough hydrogen (3.2 kg/week) for typical driving requirements (assuming that a fuel cell vehicle will average 10,000 miles annually with a fuel economy of 60 mpg). Using the system according to the teaching of the present invention to construct and optimize a PV-electrolysis system with high efficiency makes it practical to fuel vehicles with renewable hydrogen and resolve all issues of pollution from motor traffic.
[0050] Solar powered photovoltaic-electrolysis systems for hydrogen generation can be optimized using the methods of this system (1) either roughly by means of rules of thumb or (2) more exactly by systematically measuring the electrical and electrochemical characteristics of the PV and electrolysis devices to find the most efficient type, voltage, and number of the solar cells to give the highest conversion rate of solar energy to hydrogen fuel energy. The rate of water splitting by electrolysis using the optimized anode and cathode materials ( FIG. 4 ) was first measured as a function of the potential applied to the electrodes (operating potential, E oper ) using a DC power supply. It was found that the current in the electrolysis experiments is proportional to the rate of electrolysis, the production of hydrogen gas, and hydrogen fuel energy, according to Faraday's Law (Equation 4) where F is Faraday's constant (˜96,500 coulombs/equivalent weight) and increases with increasing operating potential.
[0000]
Mass
of
H
2
=
equivalent
weight
×
I
oper
×
time
F
(
Equation
4
)
[0051] When a PV source is used for the direct current, the DC potential applied to the electrolysis system is limited by the output of the PV circuit, and the electrolysis current is limited by the applied potential and the series resistance of the electrolysis system as well as the response of the PV system to operating under the load created by the electrolysis system. The potential actually applied by a PV system is not the open circuit potential E oc , but the operating potential E oper (both measured as shown in FIG. 3 ). E oper is almost always much lower than E oc because of the resistance of the load (electrolysis system). For the PV system to most efficiently power the electrolysis, the PV modules must be capable of giving their best performance under the potential and load conditions required by the electrolysis cell. The best performance conditions of a PV module or solar cell are called its maximum power point (mpp), defined by the potential (E mpp ) and current (I mpp ), at which it produces its maximum power (P mpp =E mpp ×I mpp ). If the E mpp and I mpp correspond closely to the operating conditions, E oper and I oper of the electrolysis system, the efficiency of solar energy conversion to hydrogen will be optimized, giving the greatest hydrogen production for a given system and time. The mpp is found by plotting the current (I) versus potential of the PV device while it is irradiated by sunlight of a known intensity (Emery, 2003). These measurements are usually carried out under standard test conditions (STC) using 100 mW/cm 2 i.e., 1000 W/m 2 of sunlight—called one sun, the equivalent of average summertime sunlight for cloud free conditions at noon in the central northern hemisphere at the surface of the earth (AM 1.5 Global).
[0052] An example of the power curve of a PV module, which is generated by multiplying the current times the potential, is shown in FIG. 10 . The maximum power point (mpp), with characteristic E mpp and I mpp values, is a property of each photovoltaic cell or module of several multiple cells in series. As shown in FIG. 10 , a PV system gives its greatest power when operating under a load with an optimal resistance (E mpp /I mpp ). If the circuit resistance is extremely low, the circuit approaches a short circuit condition under which the power approaches zero ( FIG. 10 ). The maximum power point potential (E mpp ) which is the potential of the PV system giving its greatest power, is less than the open circuit potential (E oc ) where R approaches infinity and I approaches zero. The optimum PV-powered electrolysis system must have a characteristic maximum power point such that E mpp and I mpp closely match the operating voltage (E oper ) and operating current (I oper ) of the electrolysis cell, i.e., their dividend (E mpp /I mpp ) matches electrolysis cell operating resistance (R oper ). Since the resistance of an electrolysis cell is non-linear and non-ohmic, it could not be measured directly with a simple ohm meter (as one can measure the resistance of a wire), and resistance measurements were not used in optimizing the PV-electrolysis system.
[0053] However, the PV-electrolysis system can be effectively optimized with the process of this system by: (1) using optimized anode and cathode materials, optimal current density on the electrodes, and optimal electrolyte concentration, (2) designing the PV module to give the optimal E mpp 2.5 volts DC that matches the most efficient range of operating potential (E oper =1.8 to 2.5 volts). Thus, a rule of thumb for PV-electrolysis optimization is to use a PV module with E mpp of 2.0 to 3.0 volts DC to match the best operating potential of the optimized electrolysis cell E oper of 1.8 to 2.5 volts. The current and power curves plotted versus potential for this type of PV module are illustrated in FIG. 11 . Some PV-electrolysis systems require E mpp values higher than 2.5 volts DC (up to 3.0 volts DC) to reach the maximum efficiency for hydrogen production from a single electrolysis cell. Several examples of crystalline silicon PV materials were optimized by the process of this system. Six c-Si solar cells (Connecticut Solar) connected in series gave the highest optimum efficiency (7.2%) for hydrogen production with E mpp of 2.5 volts DC. The reason for the superior performance of the CT Solar cells is due to their E mpp value of 0.41 volts per solar cell which allowed six cells in series to give E mpp of 2.46 volts (6×0.41) which closely matched the optimum E oper requirement of the electrolysis cell.
[0054] In practical terms, too little potential (E mpp and E oc ) is probably worse than too much because the efficiency falls off more sharply below the optimum potential than above the optimum potential ( FIGS. 9 and 11 ). FIG. 11 also shows the optimum range of PV potential (E mpp and E oc ) needed to drive electrolysis with the greatest efficiency. Thus, the detailed procedure for making PV-electrolysis systems would be to use enough solar cells in series to give an E mpp as close as practical to 2.5 volts DC, and preferably in the range of 2.0-3.0 volts (and/or an E oc in the range of 3.0-4.0 volts), preferably in the middle or higher part of these ranges rather than the lower end. Thus, if the E mpp of the PV module is less than 2.5 volts (the E oc is less than 3.5 volts), one more solar cell should usually be added in series with each module. The additional solar cell in each module would increase E mpp by about 0.41 volts and E oc by about 0.6 volts. Several of these optimized solar systems with about 2.5 volts E mpp can be connected in parallel to the electrolysis cell to generate hydrogen more rapidly by increasing the total current (I oper ) as shown in FIG. 2 . It would also be possible to optimize a PV-electrolysis system based on a PV system connected to an electrolyzer with multiple electrolysis cells in series (i.e., a multicell electrolyzer stack) by using the same method employed for a solar cell connected to a single electrolysis cell. In the case of the multicell PV-electrolyzer, the process of optimization would be done in the same way as for a single electrolysis cell except that the optimum PV voltage required to operate the multicell electrolyzer with N number of cells in series would be equal to approximately N times the voltage required for a single electrolysis cell.
[0055] The requirements for an optimized PV-electrolysis system determined in this system and its preferred embodiment are summarized in Table 2. The main components of the experimental PV-electrolysis systems optimized are shown in FIG. 12 .
[0000]
TABLE 2
Characteristics for an Optimized
PV-Electrolysis System for Hydrogen Production
Characteristics
Benefits
Electrolyte
5 M (22%-25% by mass) KOH
Maximum electrolyte
conductivity &
electrode durability
Electrodes
Ni cathode & Ni—RuO 2 anode
Optimum electrode
efficiency &
minimum over potential
Current
Less than 12 mA/cm 2
Electrodes sized for
density
maximum efficiency
PV Module
Design with E mpp of 2.5 (2.0-
Optimum match of PV
3.0) volts DC
voltage with electrolysi
s system voltage
[0056] The features of this optimization process include:
[0057] An optimization process for scaling up solar hydrogen production that yields up to 7.2% efficiency, which is greater than any reported PV-electrolysis efficiency.
[0058] Reducing cost for hydrogen production to about $3 per kg due to the simplified, 7.2% efficient system and eliminating many prior art components such as voltage converters, controllers, and batteries.
[0059] The efficiency optimization process described above which requires simple efficiency determination using measurements of current and the area of the PV system and use of manufacturer's mpp specifications to estimate the number of solar cells in series that give maximum hydrogen generation efficiency.
[0060] An optimized PV-electrolysis system design and preferred embodiment consisting of: (1) a nickel foil cathode (hydrogen production electrode), (2) a specially treated ruthenium dioxide (RuO 2 ) coated nickel foil anode as described above (oxygen production electrode), (3) 5 M aqueous potassium hydroxide electrolyte solution, (4) a PV system consisting of 6 or 7 crystalline silicon solar cells in series to produce the optimum E mpp of 2.0 to 3.0 volts, (5) an external circuit such as a wire or ammeter as shown in FIG. 2 to electrically connect the PV system to the electrodes in the electrolysis chamber and (6) an electrolysis chamber consisting of cathode and anode sections separated by an impermeable divider from the top of the chamber to a point below the bottom of the electrodes, which allows the bubbles of hydrogen and oxygen gas to rise to the top of the chamber separately. The electrolyte in the anode and cathode sections is connected, however, by an opening or salt bridge at the bottom of the chamber as shown in FIG. 2 to provide electrochemical connection between the electrodes that is necessary for ion transport and electrolysis to occur. The balance of the gas generation system needed for producing hydrogen fuel requires only commercially available gas purification equipment, piping, compression, and storage modules.
[0061] The optimized PV-electrolysis system in this system can be given appropriate corrosion resistant encapsulation to become a photoelectrochemical (PEC) device in a self-contained, scaled-up solar hydrogen generator using a photoelectrochemical device in a plastic specially designed chamber to increase the rate of the hydrogen production by focusing and concentrating natural sunlight on the PV system. This could potentially raise the hydrogen production rate by several-fold. Using the optimized design of this system in such special chamber further reduces the cost of hydrogen fuel production significantly by reducing the area of the PV panels needed to achieve the optimal current density in a PEC reactor.
[0062] The cost estimate for renewable solar hydrogen generation for the PV-electrolysis system, according to the present invention, is projected to be as low as gasoline for the same mileage. Optimized PV-electrolysis production of hydrogen could cost $2-3 per gallon of gasoline equivalent, compared to more than $11 per gallon of gasoline equivalent for solar-generated hydrogen from current photovoltaic and electrolyzer technology.
[0063] The scaled-up, optimized PV-electrolysis design of this system could be built with currently available, commercial manufacturing processes, utilizing commercially available photovoltaic cells and electrolyzers to make inexpensive, practical fueling systems able to produce hydrogen on a home fueling scale or for various large or small fleet fueling projects without air pollution or global warming. The efficiency, durability, and cost of the resulting solar hydrogen systems have been explored and would be competitive with conventional fossil fuels. Also, the scale up in the size of this device should be linear, since it would merely involve connecting several PV modules to larger electrolysis cells and/or connecting the hydrogen gas output of many small reactors to a common storage system.
[0064] Current photovoltaic modules connected to prior art electrolyzers could also be used to split water, but the cost of the hydrogen (more than $11 per gallon of gasoline equivalent) would be much higher than hydrogen from our optimized PV-electrolysis design or PEC devices which do the same thing. Either of the photovoltaic devices mentioned earlier (single or multi-junction amorphous silicon and crystalline silicon) could be used in the system with a KOH solution and sunlight.
[0065] The optimized PV-electrolysis system has an efficiency of about 7% for conditions referred to as AM1.5 global (this is approximately noon time sun on a cloud-free day in the summer in the northern U.S.). Such conditions can provide the equivalent of approximately 6-8 hours of irradiance at 1000 W/m 2 . For such conditions, the system provides a practical means of supplying renewable, non-polluting hydrogen fuel now by partnering with suppliers to make and further improve such systems. The solar hydrogen fueling systems could be built in most parts of the U.S. although they would be most productive in the desert Southwest and sunbelt areas. The system works, albeit at a reduced hydrogen output, on cloudy days. The protective surfaces that are currently used on commercially available solar cells (glass and plastics resistant to attack by ozone and other atmospheric pollutants) also resist attack by 5 M KOH used in our electrolysis system.
[0066] The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention. | A method for configuring a solar hydrogen generation system and the system optimization are disclosed. The system utilizes photovoltaic modules and an electrolyte solution to efficiently split water into hydrogen and oxygen. The efficiency of solar powered electrolysis of water is optimized by matching the most efficient voltage generated by photovoltaic cells to the most efficient input voltage required by the electrolysis cell(s). Optimizing PV-electrolysis systems makes solar powered hydrogen generation cheaper and more practical for use as an environmentally clean alternative fuel. | 8 |
FIELD OF THE INVENTION
[0001] The present invention relates to a valve especially a throttle valve, as well as to a method of operating the valve, a method of manufacturing the valve and to use of the valve in the field of weaving, e.g. in jet weaving. The present invention also relates to a weaving loom comprising the valve and a method of weaving using the valve.
BACKGROUND TO THE INVENTION
[0002] In an air jet weaving system, compressed air is used to draw weft threads from supply spools and to blow them into the shed of an air jet loom. A set of relay nozzles is used to support the movement of the weft thread across the shed, which may be several metres in width. Additional nozzles at the far end of the shed may stretch an inserted thread during a weaving operation. An example air jet loom is described in U.S. Pat. No. 4,534,387.
[0003] It is known to adjust the airflow to the main or to the relay nozzles according to the kind of weft thread to be woven. For example, a smooth and strong filament yarn can be woven with a high airflow at the relay nozzles while a weak spun yarn, or a spun yarn with several irregularities, can be woven only with a lower airflow at the relay nozzles. In order to successively insert two or more kinds of weft threads, the airflow of the relay nozzles can be set at a value required by the weakest type of weft yarn so that the weft yarn is not blown apart, broken or damaged.
[0004] U.S. Pat. No. 4,534,387 provides two airflow rates for the relay nozzles and selects the correct airflow such that a yarn will not be blown apart and such that the yarn will be inserted across the shed to arrive timely at the other side or far end of the shed. The weaving machine speed is adapted to suit to the slowest yarn. This machine requires a separate pressure-reducing valve for each required airflow rate.
[0005] U.S. Pat. No. 6,062,273 describes an electrically actuated throttle valve for an insertion nozzle. The throttle valve comprises a plunger which is movable, in a linear direction, within a bore hole. The plunger can be positioned at a desired distance from a valve seat. This type of valve is relatively slow to operate. In situations where the airflow rate needs to be varied for each insertion, the valve has to operate in a period of less than 35 msec. A second problem with this type of valve is that it has a rubber sealing ring which surrounds the plunger to prevent compressed air from escaping from the valve. This sealing ring is prone to wear and thus this type of valve has a limited life time when used in situations where the airflow rate needs to be varied for each insertion.
[0006] It is desirable to have a reduced number of valves as these valves are expensive and are volume/area consuming items. It is also desirable to provide a valve which has a long life time and which does not wear so rapidly. Further, it is also desirable to have a rapidly operating valve.
SUMMARY OF THE INVENTION
[0007] The present invention seeks to provide an improved valve as well as a method of operating the valve, a method of manufacturing the valve, use of the valve in the field of weaving, e.g. in jet weaving, a weaving loom comprising the valve and a method of weaving using the valve. An advantage of the present invention is rapid speed of operation allowing airflow rate to be varied for each insertion and even during an insertion of a weft thread in a weaving loom.
[0008] A first aspect of the present invention provides a valve comprising:
[0009] a housing having a fluid inlet for receiving a flow of compressed fluid and a fluid outlet;
[0010] a flow duct movably mounted with respect to the housing, the duct having a fluid inlet for receiving a flow of compressed fluid and a fluid outlet, the fluid outlet being positioned around at least a part of the circumference of the duct and being dimensioned to provide a different flow rate at different sections or positions around the circumference of the duct;
[0011] the fluid outlet of the housing being alignable with a portion of the fluid outlet of the duct to provide a flow rate related to the relative position of the portion of the fluid outlet of the duct and the fluid outlet of the housing; and,
a drive element for moving the duct with respect to the housing such that a desired portion of the fluid outlet of the duct aligns with the fluid outlet of the housing. The valve may operate as a so-called throttle valve.
[0013] A valve of this kind has an advantage of being quickly movable into a desired relative position in order to regulate fluid flow through the valve. The duct can be formed with a thin tubular wall which makes the duct lightweight and with low inertia. A valve having a tubular duct having a fluid outlet allowing a different fluid flow around the circumference of the duct allows to dimension the outlet of the duct in a simple manner to provide a different fluid flow rate through the valve. The rapid speed of operation allows a fluid flow rate to be varied at each insertion and even during the insertion of a weft thread. The valve is designed to have a long operational lifetime as, even if the outer surface of the duct wears, the outlet will not substantially change in size and the throttling effect will remain substantially the same.
[0014] It is preferred that the valve comprises a flow duct mounted rotatably with respect to the housing and a drive element for rotating the duct with respect to the housing. The duct of such a valve only needs to be rotated by a small angular distance, which can be achieved rapidly and reliably. Such a movement can normally be done more quickly than a movement in a valve which operates by linear movement along a borehole.
[0015] It is preferred that the valve is not provided with a seal with moving parts which could wear and become unreliable. Particularly, there is no seal provided with respect to the flow duct. The valve can have a means for impeding fluid flow by an amount determined by the position of the fluid outlet of a duct. To this end or in applications where an on-off function is required, a shut-off valve can be positioned downstream of the throttle valve.
[0016] It is preferred that the drive element, such as a motor and coupling device, is positioned within the flow path through the valve. This has an advantage of avoiding the need for a seal between a moving valve element and the housing to prevent fluid escaping from the housing. It also has an advantage of cooling the drive element.
[0017] Preferably, the drive means, such as a motor, has a drive shaft which is mounted coaxially with the longitudinal axis of the duct.
[0018] The fluid inlet of the duct can be located in an end face of the duct. More particularly, the inlet may be positioned around the circumference of the duct at a position spaced along the duct from the fluid outlet and can take the form of a set of apertures, e.g. holes or slots in the wall of the duct. This allows the drive element to connect to the end face of the duct and to use a duct with a small the diameter, which further reduces the weight of the duct and its moment of inertia. This improves the ability to quickly move into a desired angular position.
[0019] The fluid outlet of the duct can comprise a slot around a part of the circumference of the duct or a set of holes, with the size of individual holes and/or the density of holes in the set differing around the circumference of the duct.
[0020] In order that the outlet of the duct can maintain a simple fitting to the fluid outlet of the housing through a range of angular positions, it is preferred that both the flow duct and the part of the housing in the region of the fluid outlet are cylindrical. The remainder of the duct can be of a different shape although, for ease of manufacture and cost, it is preferred that the entire duct is substantially cylindrical.
[0021] The invention has a particularly advantageous application in the field of air jet weaving but the invention is not limited to this application.
[0022] The use of valves according to the invention in an airjet loom also allows use of one air tank for all the relay nozzles and also for the main nozzles. Of course a limited number of air tanks may still be used that can supply air at a given pressure to a respective relay or to a respective main nozzle via a valve according to the invention.
[0023] Further aspects of the invention provide a controller for controlling operation of a valve according to the invention. The control functionality described here can be implemented in software, hardware or a combination of these. Accordingly, another aspect of the invention provides software for controlling operation of the valve. The software may be stored on an electronic memory device, hard disk, optical disk or other machine-readable storage medium. The software may be delivered as a computer program product on a machine-readable carrier or it may be downloaded directly to the controller via a network. Further aspects of the invention include a manufacturing method for such a valve, a weaving loom comprising such a valve and a method of operating such a valve.
[0024] A further aspect of the invention provides a valve assembly comprising:
[0025] a housing having a fluid inlet for receiving a flow of compressed fluid, a fluid outlet and a flow path joining the inlet and the outlet;
[0026] a valve member comprising a tubular flow duct movably mounted within the flow path which is operable to regulate flow along the flow path by positioning the fluid outlet of the duct, more particularly by aligning a portion of the fluid outlet, with respect to the outlet of the housing; and,
[0027] a drive element for operating the valve member, the drive element being mounted in the flow path.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] Embodiments of the invention will be described with reference to the accompanying drawings in which:
[0029] FIG. 1 schematically shows a jet weaving machine in which the invention can be used;
[0030] FIG. 2 shows a first embodiment of a throttle valve for use in the machine of FIG. 1 ;
[0031] FIG. 3 shows a second embodiment of a throttle valve for use in the machine of FIG. 1 ;
[0032] FIG. 4 shows a cross-section of a variant of a duct as in FIG. 3 near its outlet;
[0033] FIG. 5 shows the outlet of the valve shown in FIG. 3 in more detail, and;
[0034] FIG. 6 shows a third embodiment of a throttle valve for use in the machine of FIG. 1 .
DESCRIPTION OF PREFERRED EMBODIMENTS
[0035] The present invention will be described with respect to particular embodiments and with reference to certain drawings but the invention is not limited thereto but the invention is only limited by the claims. The drawings described are only schematic and are non-limiting. In the drawings, the size of some of the elements may be exaggerated and not drawn on scale for illustrative purposes. Where the term “comprising” is used in the present description and claims, it does not exclude other elements or steps. Furthermore, the terms first, second, third and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other sequences than described or illustrated herein.
[0036] The present invention will mainly be described with reference to the use of a throttle valve in a weaving loom. Other applications of such a valve are in textile machines whereby a different fluid flow through the valve is required to provide a different fluid flow through a nozzle or similar device of the textile machine. In addition, the term “throttle valve” should not be interpreted as including any limitations other than those in the attached claims.
[0037] FIG. 1 shows an overall schematic view of a weft insertion system of an air jet weaving loom. Three main jet nozzles 2 a , 2 b , 2 c and three additional main jet nozzles 2 d , 2 e , 2 f are shown. Each main nozzle 2 a , 2 b , 2 c , 2 d , 2 e , 2 f is supplied with air from a reservoir 5 via an adjustable throttle valve 11 a , 11 b , 11 c , 11 d , 11 e , 11 f and a shut-off valve 10 a , lob, 10 c , 10 d , 10 e , 10 f which are described more fully below. The reservoir 5 comprises pressurised air at a given pressure. A weft preparation device 7 a , 7 b , 7 c draws off a weft thread 8 a , 8 b , 8 c from a corresponding yarn supply spool 9 a , 9 b , 9 c . Each supply spool 9 a , 9 b , 9 c may be provided with a different kind of weft thread, e.g. weft threads having different properties, such as e.g colour or thickness. The weft preparation device 7 a , 7 b , 7 c stores the weft thread 8 a , 8 b , 8 c on a winding drum and releases the required length of the weft thread 8 a , 8 b , 8 c at the proper moment in the weaving cycle to be inserted into the shed 1 by means of the associated jet nozzles 2 a , 2 d , the associated jet nozzles 2 b , 2 e or the associated jet nozzles 2 d , 2 f . The shed 1 is formed in a known manner between two planes of warp threads. The weft threads 8 a , 8 b , 8 c may be inserted in the warp shed 1 according to a predefined sequence which is programmed in controller 20 . Several sets of relay nozzles 4 a , 4 b , . . . , 4 x are positioned across the shed 1 , and serve to carry a weft thread 8 a , 8 b , 8 c across the shed 1 . The relay nozzles 4 a , 4 b , . . . , 4 x are supplied with air from reservoir 5 via a further throttle valve 13 a , 13 b , . . . , 13 x and shut-off valve 12 a , 12 b , . . . , 12 x . At the far end of the shed 1 there is a so-called stretching nozzle 3 which serves to stretch an inserted weft thread 8 a , 8 b , 8 c . This nozzle 3 is also supplied with air from reservoir 5 via a further throttle valve 15 and shut-off valve 14 . Controller 20 operates the throttle valves 11 a , 11 b , 11 c , 11 d , 11 e , 11 f , 13 a , 13 b , . . . , 13 x , 15 and shut-off valves 10 a , 10 b , 10 c , 10 d , 10 e , 10 f , 12 a , 12 b , . . . , 12 x , 14 to provide a required air flow rate at each moment in the weaving cycle during the weaving operation. For a desired weaving pattern, controller 20 has a set of instructions which determine, amongst others, the required weft threads 8 a , 8 b , 8 c , airflow rates for the nozzles, and also valve settings and timings for the throttle valves 11 a , 11 b , 11 c , 11 d , 11 e , 11 f , 13 a , 13 b , . . . , 13 x , 15 and the shut-off valves 10 a , 10 b , 10 c , 10 d , 10 e , 10 f , 12 a , 12 b , . . . , 12 x , 14 . Further a weft thread detector 6 is provided at the far end of the shed 1 in order to determine the arrival of the weft thread 8 a , 8 b , 8 c.
[0038] FIG. 2 shows a first embodiment of the throttle valve 13 a according to the present invention and shut-off valve 12 a in more detail. The throttle valve 13 a comprises a housing 50 which connects, in a fluid-tight manner, to an air reservoir 5 . The housing 50 comprises a fluid inlet 54 for receiving a flow of compressed air and a fluid outlet 55 . The fluid-tight seal is provided by bolts 52 and a sealing ring 57 . Housing 50 has a channel 51 , e.g. a bore hole in which a tubular duct 60 is mounted. In this embodiment, duct 60 comprises a thin-walled tube which is cylindrical along its entire length, although other shapes are possible. In a preferred embodiment the tube is formed of metal with a wall thickness of about 0.2 mm or more particularly with a wall thickness less than 1 mm. A drive element, more particularly a motor 70 is mounted between the air reservoir 5 and channel 51 of the housing 50 . A drive shaft 72 extends from the motor 70 and the drive shaft 72 is connected, via a coupling device 74 , to the upstream end of the duct 60 . The drive shaft 72 is aligned with the longitudinal axis 61 of the duct 60 . Duct 60 is supported at the upstream end by the drive shaft 72 and coupling device 74 , and at the downstream end by a sleeve or bearing 58 which fits between the duct 60 and housing 50 . The bearing 58 is formed as a tubular element that is fixed, e.g. glued, into the channel 51 of the housing 50 . The housing 50 has a fluid outlet 55 near the upper face of the housing 50 , e.g. a circular bore hole or a slot-like opening. The fluid outlet 55 comprises an opening in the bearing 58 which is situated in the prolongation of an opening 55 in the housing 50 . The air reservoir 5 can be connected in a known manner to an air supply line (not shown). The housing 50 can be mounted to the frame 53 at a place adjacent to an associated nozzle of the loom.
[0039] Duct 60 has a set of inlet holes 62 at its upstream end. Each of the holes 62 extends from the outer surface of the wall of the duct 60 to the hollow interior of the duct 60 . In this embodiment the holes 62 are located around the entire circumference of the duct, along a band which is almost 50% of the total length of the duct 60 . The number of holes 62 is chosen so as to permit, in use, a good flow of air into the interior of the flow duct 60 , while maintaining sufficient strength of the duct 60 to withstand air pressure and rapid movement of the duct 60 . At the downstream end of the duct 60 , a V-shaped slot 65 is defined in the duct 60 . The slot 65 extends from the outer surface of the wall of the duct 60 through to the hollow interior. The slot 65 extends partially around the circumference of the duct 60 . Clearly, the circumferential length of the slot 65 is limited to a part of the circumference of the duct 60 , otherwise it would dissect the duct 60 . The V-shaped slot 65 aligns with the outlet 55 of the housing 50 . The outlet 55 is dimensioned such that it overlaps only a portion of the slot 65 . As noted above, duct 60 is rotatable about longitudinal axis 61 . In use, motor 70 turns drive shaft 72 , and thus tube 60 , into a particular angular position. The position of the slot 65 with respect to the outlet 55 defines what part or portion of the slot 65 is aligned with the outlet 55 and thus regulates how much air can flow from the air reservoir 5 , through the duct 60 and through the outlet 55 . In this way it may be possible to regulate the air flow through the outlet 55 between almost no air flow and maximum air flow, e.g. creating a flow through opening from the duct 60 to the opening 55 between 0% or 100% of the opening of the outlet 55 . Of course, according to a variant the flow through opening may also be between for example 20% and 100% of the opening of the outlet 55 . The duct 60 is shaped or dimensioned to provide a different flow rate at different sections around the circumference of the duct 60 , e.g. by the shape of the slot 65 around the circumference of the duct 60 .
[0040] A shut-off valve 12 a (shown schematically) is mounted downstream of the throttle valve 13 a . A plunger 83 and valve member 82 act on a valve seat and are normally biased into a closed position (as shown) by a spring 84 . The valve member 82 can be moved, e.g. electromagnetically, against the bias of spring 84 into an open position to allow air to flow from the outlet 55 to the outlet 88 . Outlet 88 connects to a main nozzle or to a relay nozzle as shown in FIG. 1 .
[0041] FIGS. 3-5 show a second embodiment of the throttle valve 13 b and shut-off valve 12 b . The main differences are in the design of the inlet and outlet of the duct 60 . In this embodiment the inlet comprises a series of slots 62 A. As shown more fully in FIG. 3 , adjacent rings of slots 62 A are offset from one another. For example, in this embodiment the housing 50 does not include a separate bearing element and the downstream end of the duct 60 is guided directly into the housing 50 .
[0042] The outlet 65 A of the duct 60 comprises a set of holes which form a band around part of the circumference of the duct 60 . The set of holes 65 A are arranged such that the achievable flow rate gradually increases at different sections around the circumference of the duct 60 , thus allowing to achieve a different flow rate or flow through opening of the valve by rotating the duct 60 with respect to the outlet 55 of the housing 50 , from one end of the outlet 65 A to the other. FIGS. 4 and 5 each show a set of holes 65 A in more detail. It will be appreciated that the pattern of FIG. 5 , which is shown as a plan view, would be wrapped around the outer wall of the duct 60 . At a first end of the outlet 65 A of the duct 60 , the holes have a small diameter. In this example a sub-set 91 have a small diameter (e.g. 0.25 mm). As one moves towards the second end of the outlet the diameter of each hole increases and the number of holes increases. A second sub-set of the holes has a larger diameter (e.g. 0.5 mm.) A sub-set 92 A of the holes at this diameter are aligned in a linear manner while a second sub-set 92 B of the holes at this diameter are staggered about a centre-line. This staggering increases the achievable flow compared to the linear alignment, while maintaining the strength of the duct 60 . A third sub-set 93 of holes have a larger diameter (e.g. 1.1 mm) and a final sub-set 94 of holes have the largest diameter (e.g. 1.5 mm). In this final sub-set 94 the holes are arranged so that, as one moves in the direction 98 by rotating the duct 60 , there is an increasing number of holes in each row that in use will be arranged in alignment with the outlet 55 of the housing 50 . This modified form of outlet 65 A of the duct 60 has an advantage in that it maintains the strength of the duct 60 better than a slot 65 and can be provided around a greater portion of the total circumference of the duct 60 . Furthermore, the outlet 65 of the duct 60 can be manufactured precisely, more particularly the holes of the outlet 65 A can be manufactured more precisely than the slot 65 in FIG. 2 .
[0043] In FIG. 5 also possible positions of the outlet 55 of the housing 50 are shown with respect to the outlet 65 A of the duct 60 . As shown in full lines the outlet 55 of the housing 50 is arranged with respect to the holes of the outlet 65 A of the duct 60 in such a way that the flow through the duct 60 and the outlet 55 of the housing 50 is almost 100% of the flow through a free outlet 55 , while in the position shown in dashed lines the outlet 55 of the housing 50 is arranged in such a way that the flow through the duct 60 and the outlet 55 of the housing 50 is only a fraction of the flow through a free outlet 55 .
[0044] Although FIGS. 2 and 3 show a different inlet and a different outlet, either of these modifications can be used independently of the other, e.g. combinations of embodiments of FIGS. 2 and 3 are possible.
[0045] FIG. 6 shows a further embodiment of the invention. In FIG. 6 the duct 160 has a conical shape, with a wide mouth 161 at the upstream end and a narrower, cylindrical section 162 at the downstream end. The downstream end 162 and outlet 65 A operate in the same manner as described above. This alternative form of inlet has the effect of funnelling airflow towards the section 162 . The mouth 161 provides an easy path for airflow into the interior of the duct 160 and thus there is no need for any holes or slots ( 62 , 62 A) in the wall of the duct 160 . As in the other embodiments, duct 160 is rotatable about its longitudinal axis 61 . A motor 70 has a drive shaft 72 which is aligned with the longitudinal axis 61 . A set of arms forming a coupling device 73 connect the drive shaft 72 to the duct 160 . There can be two, preferably three or more arms 73 . Air can freely flow between the set of arms into the interior of duct 160 . It can be seen that this embodiment is more complex to manufacture compared to a cylindrical tube 60 shown in the previous embodiments.
[0046] As described above, the entire motor 70 , drive shaft 72 , coupling device 73 , 74 , and duct 60 , 160 are mounted in the air flow path between the air reservoir 5 and outlet 55 of the housing 50 . This has the advantage that a flow of air through the valve cools these parts and prevents overheating. It also means that no seal is required between the moving valve member, more particularly duct 60 , 160 and the external atmosphere.
[0047] According to an alternative (not shown) the air flow can also flow through the motor 70 itself instead of around the motor 70 as shown in FIGS. 2 , 3 and 6 . To this end, the drive shaft 72 of the motor 70 may be made of a hollow shaft or the motor 70 may contain channels to allow the flow of air to pass along the motor 70 .
[0048] It is necessary to provide power and a control signal to the motor 70 via a control cable 40 and a connector 41 . This control cable 40 can be fitted through a borehole in the wall of the housing 50 . The borehole should be sealed against air escape, such as by a fluid-tight seal. The sealing requirements are simple since the control cable 40 is arranged stationary. This control cable 40 can according to an alternative embodiment be fitted through a borehole (not shown) in the wall of the reservoir 5 .
[0049] Friction between the duct 60 and the portion of the housing 50 in the region of the outlet 65 can be minimised by a copper or polymer bearing ring 58 in which the duct 60 will rotate. The bearing ring 58 comprises an opening 59 arranged mainly in the prolongation of the opening 55 of the housing 50 . Even if friction occurs, the heat generated due to this friction will be taken up by the airflow passing through the throttle valve 13 a , 13 b . Although it is not expected that the throttle valve 13 a , 13 b will unduly increase temperature, warm air has been found to have a beneficial effect of aiding weft insertion. It is possible that an airflow can flow between the bearing ring 58 and the duct 60 . This airflow will not be disadvantageous because normally this airflow will be small with respect to the airflow through the outlet 65 of the duct 60 and will not or only slowly change in time.
[0050] The position of the duct 60 of the throttle valve 13 a , 13 b is determined by motor 70 . Motor 70 can be a stepper motor with a suitable number of steps to permit a required degree of control of the airflow rate. Alternatively the motor 70 can be a servomotor, e.g. a DC servomotor. Feedback of the angular position of duct 60 can be provided from an encoder attached to the duct or to the drive shaft 72 of the motor 70 , e.g. an optical encoder (not shown). It is also possible to use an air flow sensor at the valve outlet 88 or at the outlet 55 of the housing 50 to generate a feedback signal for the air flow. It is also possible to use a pressure sensor at the outlet 88 or at the outlet 55 of the housing 50 .
[0051] An embodiment has been operated with a stepper motor having a total of 80 steps, with 20 steps for high airflow and 60 steps for low airflow. A controller 20 is programmed with the relationship between, on the one hand, the angular position of the drive shaft 72 or the timing of the insertion cycle, and hence angular position of the duct 60 , 160 , and, on the other hand, the flow rate that this achieves. The position of the throttle valve 13 a , 13 b is operated in coordination with the main controller 20 for the air jet loom to set the air flow to a desired rate at a desired time. A control function 22 for the motor 70 , e.g. the different motors 70 of the throttle valves 13 a , 13 b , can form part of the overall controller 20 of the machine. The control function 22 can receive an input indicative of the required airflow rate, e.g. from the set of instructions 21 for the current textile design, and outputs a control signal which causes the at least one motor 70 at a particular throttle valve 13 a , 13 b to move into an angular position which will cause the valve to achieve the desired flow rate. The control function 22 may alternatively reside locally with each motor 70 . In this case, the control signal applied to each motor controller will indicate the required flow rate. Of course, the control of the motors 70 can also occur in dependence of signals of a weft detector 6 , in other words as a function of the arrival of the respective weft thread 8 a , 8 b , 8 c at the weft detector 6 .
[0052] Consider an example weaving operation, which uses three different yarns 8 a , 8 b and 8 c , further named A, B and C, each requiring a different airflow rate. With a yarn insertion sequence of ABCABC the throttle valve will normally be operated for each insertion. With a weaving rate of 1200 insertions per minute, it is necessary to operate the throttle valve twenty times every second, i.e. each 50 msec. As is known, in each weaving cycle the insertion time interval is substantially half of the time interval available for one weaving cycle, i.e. the time interval for one insertion and the time interval for beating up the inserted weft against the fell line. If one chooses for moving the duct 60 between two insertions, e.g. during the time interval for beating up, there is about 20 msec to bring the throttle valve in readiness for the next insertion. Even if one chooses to use the practically whole insertion cycle for moving the duct 60 there will only be available 50 msec for moving the duct 60 . Of course other yarn insertion sequences can be used, depending on the desired pattern to be woven. With a yarn insertion sequence of AABBCC it is only necessary to change the throttle valve after every two insertions, as the same yarn, with almost the same properties, is inserted in two consecutive weaving machine cycles.
[0053] Referring again to FIG. 1 , the throttle valve 13 a , 13 b , . . . , 13 x can be positioned between an air tank or air reservoir 5 and a group of relay nozzles 4 a , 4 b , . . . , 4 x or between a reservoir 5 and a main nozzle 2 a , 2 b , 2 c , 2 d , 2 e , 2 f . The shut-off valve 10 a to 10 f , 12 a to 12 x , 14 is not essential but is preferable. FIG. 1 shows each time a number of the relay nozzles 4 a , 4 b , . . . , 4 x fed from the same throttle valve 13 a , 13 b , . . . , 13 x . Different relay nozzles 4 a , 4 b , . . . , 4 x along the loom may operate at a different airflow rate. For example, the last group of relay nozzles 4 x may be controlled at a higher airflow than the ones at the beginning of the shed in order to hold the weft at the end of the insertion. The throttle valve according to the invention can be used to select whatever airflow rate is required. Any other function of airflow rates along the shed can be chosen with, for example, a high airflow for some of the relay nozzles and a lower airflow for some of the other relay nozzles. The use of the throttle valve allows to use one main reservoir 5 for all the relay nozzles and possibly also for all the main nozzles. In FIG. 1 each throttle valve supplies a group of three relay nozzles 4 a , 4 b , . . . , 4 x with air. According to an alternative, each relay nozzle or groups having two, four or more relay nozzles may be supplied with air via a same throttle valve.
[0054] The throttle valve according to the invention can also be used to optimise the airflow through each relay nozzle, which will lead to less airflow and less use of pressure air for the insertion. Using a throttle valve according to the invention an airflow reduction of up to 30% is possible. Another use of the throttle valve is to vary, e.g. increase or reduce the airflow during the insertion, such that for example a large airflow is generated as the weft passes the relay nozzle while a reduced airflow is generated when the weft is farther away from the relay nozzle. Another possibility is to vary the airflow cyclically during an insertion as known from U.S. Pat. No. 3,672,406.
[0055] If the throttle valve is used to provide airflow to a main insertion nozzle, it is desirable to set the throttle valve to a required throttle position before opening corresponding shut-off valve 11 a to 11 f . If the throttle valve is used to provide airflow to a relay nozzle, the throttle valve can preferably be set to a required throttle position before opening corresponding shut-off valve 12 a to 12 x . Further advantages can be gained by changing the throttle position while a weft thread 8 a , 8 b , 8 c is being inserted.
[0056] The flow duct 60 that is movable with respect to the housing 50 or with respect to the flow path of the compressed fluid, is in the preferred embodiments shown in the drawings mounted rotatably within the housing 50 . According to an alternative not shown the duct 60 is mounted movable in the direction of the longitudinal axis 61 such that a particular portion of the outlet of the duct 60 will be aligned with the outlet 55 of the housing 50 in order to regulate the fluid flow through the valve. In this embodiment the holes of the outlet 65 A may be arranged longitudinally with respect to the duct 60 , instead of circumferentially as shown in FIG. 5 . According to a further alternative the duct 60 is movable with respect to the housing 50 both rotatable and longitudinally, for example such that the outlet of the duct 60 moves along a screw line and particular portions of the outlet of the duct 60 will be aligned with the outlet 55 of the housing 50 to regulate the fluid flow through the valve.
[0057] It is also possible that a throttle valve according to the invention is situated downstream of a shut off valve.
[0058] The invention is not limited to the embodiments described herein, which may be modified or varied without departing from the scope of the invention. It is possible to use throttle valves having the same construction or to use, for example, throttle valves having a different construction, more particularly throttle valves having a different construction for feeding an airflow to the main nozzles or to the relay nozzles or to the stretching nozzles. | A valve ( 13 a ) is described comprising: a housing ( 50 ) having a fluid inlet for ( 54 ) receiving a flow of compressed fluid and a fluid outlet ( 55 ); a flow duct ( 60 ) movably mounted with respect to the housing, the duct ( 62 ) having a fluid inlet ( 62 ) for receiving a flow of compressed fluid and a fluid outlet ( 65 ), the fluid outlet being positioned around at least a part of the circumference of the duct and being dimensioned to provide a different flow rate at different sections or positions around the circumference of the duct; the fluid outlet of the housing being alignable with a portion of the fluid outlet of the duct to provide a flow rate related to the relative position of the portion of the fluid outlet of the duct and the fluid outlet of the housing; and, a drive element ( 70 ) for moving, e.g. rotating, the duct with respect to the housing such that a desired portion of the fluid outlet of the duct aligns with the fluid outlet of the housing. The valve may operate as a so-called throttle valve. It is an advantage that the valve is quickly movable into a desired relative position in order to regulate fluid flow through the valve. The valve is designed to have a long operational lifetime as, even if the outer surface of the duct wears, the outlet will not substantially change in size and the throttling effect will remain substantially the same. | 3 |
BACKGROUND OF THE INVENTION
The present invention relates to a motorized drive for a tarpaulin closure system used with an open box-like container such as a truck box or storage bin. A tarpaulin system suitable for the application of the present invention is disclosed in my Canadian Patent 1,132,168 and corresponding U.S. Pat. No. 4,484,777. My aforementioned patents disclose a truck box having parallel side walls joined by transverse front and back end walls, with a flexible fabric cover fixed at one lateral edge to one side wall, and attached at the opposite edge lateral to a roll tube which is rotatable from side-to-side along the top surfaces of the front and back end walls of the truck box to permit winding and unwinding of the fabric from the roll tube thereby opening and closing the cover of the box structure. The foregoing roll tube is operated manually by a shaft crank connected to the roll tube by a universal joint at the back end wall of the box. Different features of lateral roll tube tarpaulin systems are disclosed in U.S. Pat. Nos. 3,384,413 to Sargent; 4,302,043 to Dimmer; and 4,505,512 to Schmeichel and Canadian Patent 1,134,411 to Block.
It has been recognized that an automatic deployment means for a lateral roll tube system, which can be rapidly operated from a remote position such as the cab of a truck or the like, is desirable. U.S. Pat. Nos. 4,095,840 to Woodard and 4,341,416 to Richard disclose motor actuated systems for deploying tarpaulin covers from front to back of a truck box. U.S. Pat. No. 4,673,208 to Tsukamoto discloses a hydraulic system for side-to-side deployment of a canvass system. Canadian Patent 1,243,062 to Hawken and U.S. Pat. No. 4,518,193 to Heider disclose electric systems for side-to-side deployment of a roll tube and canvass tarpaulin system. Each of U.S. Pat. Nos. 4,518,193 and 4,673,208, and Canadian Patent 1,243,062 disclose a complex drive system involving track mechanisms, and in the case of U.S. Pat. No. 4,673,208 a rotational drive for the roll tube which is not coordinated with the rate of lateral translation of the roll tube. In the case of Canadian Patent 1,243,062, the track system for mounting the electric motor is open to the elements and susceptible of binding from airborne debris.
It is an object of the present invention to provide a simplified motor driven box cover deployment system with a minimum of moving parts. It is also an object of the invention to provide a system for maintaining adequate tautness in the tarpaulin or cover during deployment and to ensure that the roll tube remains parallel to the side walls. It is a further object of the invention to provide a system which correlates the lateral movement of the roll tube with the rate of deployment of the fabric cover. It is also an object of the invention to provide a motorized cover deployment system which can be operated remotely.
BRIEF DESCRIPTION OF THE DRAWINGS
The best mode presently contemplated for carrying out the invention in actual practice is shown in the accompanying drawings in which:
FIG. 1 is a perspective view of a typical truck equipped with the apparatus of the invention;
FIG. 2 is a front perspective view of the truck box illustrating the pivot arm and motor system of the present invention;
FIG. 3 is a front perspective view of the truck box illustrating the roll tube in a partially deployed position; and
FIG. 4 is a side elevation view of the front end of the roll tube illustrating the tapered sheave and cable return system.
Corresponding parts in the respective figures are indicated by similar reference numbers.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is used with a tarpaulin system for a box-like structure, typically an open truck box. Referring to FIG. 1, a typical truck box has generally parallel side walls 1 and 2, and orthogonal front end wall 3 and back end wall 4. The front and back walls 3 and 4 may have a hood with peaked or gabled top rails 5. Located within the box, marginally below the rails 5, are lips 5' which support the front and back edges of the cover 7. Intermediate bows 6 extend across the truck box between the side walls 1 and 2 to assist in support of the cover 7. Typically, a roll tube 8 is positioned upon the end walls 3 and 4, parallel with the side walls 1 and 2. Canvass or other suitable weatherproof flexible fabric cover 7, sufficient in size to enclose the box opening, is attached by one edge 9 to one side wall 2 of the box. The opposite edge 10 of the fabric material 7 is attached to the roll tube by screws 11, rivets or the like. In the closed position, the cover 7 lies over the box opening, supported at its lateral edges 9 and 10 by roll tube 8 and side wall 2 respectively, and upon lips 5' of end walls 3 and 4, as well as intermediate bows 6. As may be seen in FIG. 2, to achieve the open position, the roll tube 8 is rotated counter-clockwise to roll the cover 7 upon the roll tube 8 towards the side 2 of the box to which the lateral edge 9 of the cover 7 is attached, and retained from further movement by appropriate means such as stops 12. To close the box, the roll tube 8 is rotated clockwise towards side wall 1 and the cover 7 is unwound from the roll tube 8 across the box, supported on front wall 3 and back wall 4 and intermediate bows 6. The roll tube 8 and attached cover is held at the opposite side wall 1 by an appropriate closure mechanism (not shown) acting on the roll tube such as tie-down straps or a locking mechanism as illustrated in my Canadian Patent 1,132,168.
As may be seen particularly in FIG. 4, the front end of roll tube 8 of the present invention extends beyond the front wall 3 and overhangs therefrom a distance D. The back end of the roll tube overhangs the back wall a similar distance. A motor 20, which may be either electrically, pneumatically or hydraulically actuated, is attached to the front end of the roll tube 8. The drive shaft 21 of the motor is coaxially aligned with the roll tube 8. The stator and housing portion 22 of the motor 20 is attached to one end of a pivot arm 23, which prevents the housing from rotating with the rotor of the motor. The other end of pivot arm 23 is fixed at a pivot point or bearing 24 located on a vertical plane M passing through the lateral mid-point of the truck box opening, in this case mid-way between the side walls 1 and 2 of the truck box, a distance L from each side. Thus, the pivot bearing 24 constitutes a pivot point for pivot arm 23 which lies below the top of end wall 3 a distance H which is greater than one-half the width of end wall 3, i.e., H>L as illustrated in FIG 2.
The pivot arm comprises a first rod 25 pivoted at bearing 24, and a second telescoping tube 26 which is rigidly connected to the motor housing 20. As will be discussed hereafter, this freely telescoping or extensible feature permits the pivot arm to accommodate the variation in distance between the pivot 24 and the motor 20 when the roll tube is in the open or closed position, and when it is at an intermediate position.
As may best be seen in FIG. 4, the extension D of the roll tube 8 beyond the front wall 2 towards the motor 20 is configured as a sheave or pulley 30 and has a tapered configuration 31 between transverse plates or cheeks 32 and 33. The tapered sheave 30 has a spiral groove 34 formed on the surface which serves to guide a return cable 35 onto the sheave. The return cable 35 is attached to the tapered sheave portion at the point 36 where the diameter of the sheave 30 is substantially the same or greater diameter as the combined diameter of the roll tube and cover when the cover is fully wound on the roll tube in the open position. The other end of the return cable may be attached to side wall 1 of the truck box adjacent the front end by a tension mechanism 38 or other appropriate means. In the former case, the end of the cable 37 is attached to the free end of a tension spring 39, and the other end of the spring is attached to the closed end of tube 40. The open end of tube 40 may be partially closed by an apertured grommet to reduce entrance of airborne contaminants and may utilize a roller 41 to reduce friction or wear which may arise from limited movement of the return cable 35.
In operation, when the cover is to be opened, the motor is actuated, either electrically, pneumatically or hydraulically, causing the roll tube to be rotated in a counterclockwise direction (when viewed from the front as in FIG. 2) so that the cover 7 is wound on to the roll tube 8 and the roll tube is rotated across the front and back rails 5 towards side wall 2. Simultaneously, as the cover is wound on to the roll tube, the return cable 35 is unwound from the spiral groove 34 of the tapered sheave 30. The taper and groove pitch of the sheave is selected so that the diameter of the sheave at the point where return cable 35 becomes tangent and leaves the sheave is substantially equal to the combined diameter of the roll tube 8 and the cover 7 at all positions across the box. Thus, when the roll tube is fully opened, the diameter of the roll tube 8 and cover 7 is generally the same as the diameter of the sheave at the point where the return cable 35 becomes tangent to the surface 31.
When the cover 7 is closed over the truck box, the motor 20 is actuated to rotate the roll tube 8 clockwise, permitting the cover to unwind from the roll tube. Simultaneously, return cable 35 is re-wound upon the tapered sheave 30 following the spiral groove 34. When the roll tube and cover is completely unwound (and the roll tube is locked in a latch, not shown) the cable leads off the sheave surface 31 where the sheave has a diameter marginally greater than that of the roll tube.
The correlation of the diameter of the sheave 31 to the diameter of roll tube and cover generally at all points during operation of the closure system ensures that the cover remains taut on the tube at all times, and no slack develops in the return cable 35. Thus, the end 37 of the return cable 35 can be fixed to the side wall 1. However, in consequence of expansion and contraction of the length of the return cable 35 and cover 7 as a result of varying temperature conditions and in consequence of movement of the roll tube over the locking mechanism, it is desirable to provide for some compensation in the length of the return cable. As well, adequate tension on the return cable ensures that the cable tracks in the groove 34 of the sheave 31. Compensation and tension may be provided by means of spring 39 within tube 40.
I have found that to maintain the necessary degree of correlation between the tapered sheave and the roll tube and cover, a sheave tapered at 12°, with the groove 34 pitched at 7 turns per inch performs satisfactorily with an 18 ounce P.V.C. coated stable fabric cover.
Although the present invention operates well with a single return cable 35, the degree of success in maintaining the roll tube in precise parallelism with the side edge of the truck box may be increased by utilizing a second return cable on a second tapered pulley at the back end of the roll tube 8 connected to the back wall 4 of the truck box. Such tapered sheave and return cable is operable in the same fashion as the front return cable system. Where spring tubes 40 are used, I have found that 30 to 50 pounds tension in the front tube is sufficient whereas slightly more tension may be maintained in the back tube.
Where an electric motor is utilized, a 12 volt system compatible with the electrical system of a truck can be used with a planetary gear reduction to achieve satisfactory speeds of operation. I have found that an 81/2 foot box can be opened or closed in 6 seconds using appropriately selected motor and reduction gear in the system of the present invention. A reduction gear of the type disclosed in U.S. Pat. No. 4,529,098 utilizes the planetary gears which have the salutary effect of resisting rotation of roll tube 8 when the cover is fully open, or fully closed. This rotation of resistance, or an equivalent means, is required to maintain the roll tube 8 in an angle lock of the type disclosed in my Canadian Patent 1,132,168. A simple double throw, center off switch located in the cab can be used to control operation of the motor in opposite directions, whereby the switch is turned off when the roll tube is fully deployed in either the open or closed position.
It may be desired, on occasion, to utilize the foregoing drive system of the present invention when a truck box is in an elevated or inclined dumping position. In such a case, the tapered, grooved sheave 31 may utilize a larger diameter cheek or plate 33' as shown in phantom in FIG. 4. The enlarged portion of cheek 33' will extend below rail 5, and overlie front wall 3 even when the cover is fully wound to its greatest diameter of the roll tube. Cheek 33' may then rest against a rub strip 41 when the drive is activated in an inclined position.
The present disclosure is intended to be illustrative, and not delimiting. It will be appreciated that variations in the drive mechanism, control mechanism, canvass and return system may be utilized without departing from the spirit of the invention. | The present invention relates to a motorized drive system for covering and uncovering the top of an open truck box or the like and comprises a laterally operated roll tube for winding and unwinding a flexible cover over the top of a truck box. One lateral edge of the cover is fixed to one side edge of the box opening, and the other lateral edge is attached to a roll tube. A reversible rotary motor rotates the roll tube, in conjunction with an extensible pivot arm and a cable return mechanism utilizing a tapered grooved sheave to provide constant tension and to facilitate smooth and consistent rectilinear movement of the roll tube for winding and unwinding of the cover. | 1 |
BACKGROUND OF THE INVENTION
The present invention relates to an improved line pressure control device of an automatic transmission for vehicle.
In an automatic transmission line pressure for a actuating oil from an oil pump driven by the engine is usually controlled to be a predetermined oil pressure by a line pressure adjusting valve. Manifold negative pressure from the engine is introduced into a vacuum diaphragm of a throttle valve to generate a throttle pressure corresponding to the engine load. A governor pressure corresponding to a vehicle speed is generated from the line pressure through a governor secured to an output shaft of the automatic transmission. A hydraulic pressure change-over valve is activated (shift valve) by the throttle pressure and the governor pressure and, properly supplies the line pressure to friction elements such as a clutch, a brake and the like for changing over a power transmission route of a pair of planetary gears, and performs automatic transmission operation. The throttle pressure is also introduced into the line pressure adjusting valve so as to adjust the line pressure corresponding to the load of the engine, so that the friction elements actuated by the line pressure do not produce any slippage.
Exahust gas from automobiles is now strictly regulated and a countermeasure to control exhaust gas to meet standards from each car is necessary. Under the influence of, for example, an exhaust reflux device for returning a part of exhaust gas to an engine inlet system, the engine manifold negative pressure does not precisely correspond to the load of the engine. In the above-described prior automatic transmission, therefore, the line pressure adjusted by the manifold negative pressure will not correspond to the load of the engine and the line pressure becomes too great or too little compared to the load of the engine. As a result, the clamping force of the friction element actuated by the line pressure becomes too large producing a transmission shock or the clamping or coupling force is too weak making the friction element slip. Because of these disadvantages the engine output is not effectively utilized, fuel expense becomes greater and the friction element is damaged.
It has been proposed in an automatic transmission not to directly introduce the manifold negative pressure into the vacuum diaphragm of the throttle valve controlling the line pressure. Instead a negative pressure corresponding to the degree of throttle opening (accelerator pedal depression amount) representing the load of the engine is produced, and the negative pressure is introduced into the vacuum diaphragm for the purpose of avoiding the above described disadvantages.
An example of such an automatic transmission with an electronic control is shown in FIG. 1. In the system of FIG. 1, the throttle opening degree, manifold negative pressure, inlet air amount or fuel injection amount and the like are detected. A signal corresponding to the load of the engine is supplied from engine load sensor 20 and a signal corresponding to a car or vehicle speed is supplied from a vehicle speed sensor 21 to a shift control unit 22, respectively, and the shift control unit 22 properly actuates the shift valves 23 in response to these input signals. An oil pump 24 driven by the engine sucks and exhausts actuating oil from an oil reservoir 25. The actuating oil is adjusted to a line pressure by a line pressure adjusting valve 26 and is constantly supplied to a manual valve 27. When a driver operates the manual valve 27 to an operating range, the line pressure is introduced into a shift valve selected from the shift valves 23, and the shift control unit 22 selects and actuates the shift valves 23 in accordance with the driving state of the automobile, so that the line pressure is supplied to one of the friction elements, 28, actuates this friction element and carries out automatic transmission operation.
The shift control unit 22 applies the engine load signal to a hydraulic pressure adjusting valve (vacuum throttle valve) 29. The hydraulic pressure adjusting valve 29 produces a hydraulic pressure corresponding to the engine load acting on the line pressure adjusting valve 26 in accordance with the engine load signal, operates on the line pressure adjusting valve 26 and functions to make the line pressure precisely correspond to the magnitude of the engine load. A line pressure control system is represented in FIG. 2 in more detail. The block 29 of FIG. 1 identified by the legend hydraulic pressure adjusting valve includes a vacuum diaphragm 2, a negative pressure conduit 3, a diaphragm device 4, a negative pressure solenoid valve 9 and an atmospheric pressure solenoid valve 10 in addition to the hydraulic pressure adjusting valve provided in the automatic transmission body 1. An electronic circuit 8 (FIG. 2) is provided within the shift control unit 22 shown in FIG. 1. The vacuum diaphragm 2 receives a negative pressure in the negative pressure chamber 4A of the diaphragm device 4 through the conduit 3. This negative pressure actuates the hydraulic pressure ajdusting valve through the vacuum diaphragm 2 and adjusts the line pressure as described above, so that the magnitude of the negative pressure (absolute value) corresponds to the line pressure in inverse proportion. The negative pressure in the chamber 4A is electrically detected as a line pressure signal by means of a line pressure sensor operated in response to the displacement of the diaphragm device 4 and comprising a variable resistor or the like. The amount of depression pedal 6 of the vehicle accelerator corresponding to the engine load, is electrically detected by a throttle sensor 7 comprising a variable resistor or the like and the throttle sensor is used as an engine load sensor. An actually measured line pressure signal V q and an engine load signal V T from the line pressure sensor 5 and the throttle sensor 7 vary, respectively, as shown in FIGS. 3 and 4. These signals are supplied to the electronic circuit 8. The electronic circuit 8 compares the signal V q representing the line pressure with the signal V T representing the engine load and determines whether the signal V q corresponds to the ideal line pressure as shown by the graph in FIG. 5. When the line pressure uses above the ideal value (i.e., the actually measured line pressure signal V q is larger than a target negative pressure V T '), the negative pressure solenoid valve 9 is opened by supplying a signal thereto. A vacuum tank 12 storing the negative pressure from the engine manifold through a check valve 11 will then supplement the negative pressure to the vacuum diaphragm 2 so as to actuate the hydraulic pressure adjusting valve to decrease the line pressure. In the opposite case, the atmospheric pressure solenoid valve 10 is opened by supplying a signal thereto and the hydraulic pressure adjusting valve is actuated to increase the line pressure. As a result, the line pressure is controlled along target characteristics shown in FIG. 5 to correspond to the engine load, and even if the manifold negative pressure does not precisely correspond to the engine load due to the exhaust gas countermeasure, the automatic transmission can be controlled as desired.
In such an automatic transmission, however, when a diaphragm 4B of the diaphragm 4 does not promptly stop at a balanced position between the negative pressure and a spring 4C during the above described operation, but over shoots, the operational stability of the control system suffers the amount of power consumption by the solenoids valve 9, 10 is increased and the amount of negative pressure consumption in the vacuum tank 12 is increased.
In order to solve this problem, stabilizing the control system by providing a dead zone for inactivating both the solenoids 9 and 10 has been considered, but this kind of conventional countermeasure only provides a dead zone on the + side or - side to the target value, so that the over shoot in the vicinity of the target value is prevented in one direction but not in the opposite direction. As a result, the problem is not always avoided and the actual target value is not achieved. Moreover, it has hitherto been considered to provide a pulse width for determining the opening time of the solenoids 9, 10 in accordance with the magnitude of deviation of the actually measured value from the target value, thereby improving the response of the control system and promptly positioning the actually measured value in the dead zone. However, in this case, the dead zone is set only on one side of the target value as described above and being the deviation is measured with the target value being a boundary value of the dead zone. For this reason, controlling the pulse width in accordance with deviation for the actually measured value in does not tend to promptly position the dead zone in the strict sense, and these countermeasures do not always attain the desired object.
SUMMARY OF THE INVENTION
An object of the present invention is to eliminate the above described disadvantages of the conventional line pressure control device of automatic transmission.
Another object of the present invention is to provide a line pressure control device in an automatic transmission which sets the dead zone on both sides, i.e. at the + side and the - side of the actually measured line pressure or the target line pressure.
Another object of the present invention is to provide a line pressure control device of an automatic transmission in which the deviation is obtained by comparing the actually measured line pressure as a value in the dead zone with the target line pressure instead of comparing the actually measured line pressure as a boundary value to determine the dead zone with the target line pressure.
According to the present invention, the line pressure control device of an automatic transmission comprises a pair of planetary gears, a plurality of friction elements for determining a power transmission route of the pair of the planetary gears, an engine load sensor for generating a signal corresponding to the engine load, a speed sensor for generating a signal corresponding to the running speed of a vehicle, an oil pump driven by the vehicle engine, a line pressure adjusting valve for producing a line pressure by adjusting actuating oil from the oil pump to a predetermined hydraulic pressure, a hydraulic pressure adjusting valve for producing a controlled hydrualic pressure acting on the line pressure adjusting valve and adjusting the line pressure to a value corresponding to the engine load through the line pressure adjusting valve, a hydraulic pressure change-over valve for supplying the line pressure to either one of said friction elements, a circuit for obtaining a corresponding target line pressure signal from an actually measured load signal obtained from the engine load sensor, a line pressure sensor for generating an actually measured line pressure signal corresponding to the line pressure, a converter means for converting at least one of the target pressure signal and the actually measured line pressure signal into an upper limit line pressure signal and a lower limit line pressure signal which are set above and below the target signal or actually measured signal by given amounts, respectively, and a decision circuit for comparing the upper and lower limit line pressure signals with the other of the target line pressure signal and the actually measured line pressure signal and properly driving and controlling the hydraulic pressure adjusting valve in accordance with the result of the comparison.
A line pressure control device of an automatic transmission according to the present invention comprises a pair of planetary gears, a plurality of friction elements for determining a power transmission route of the pair of the planetary gears, an engine load sensor for generating a signal corresponding to the engine load, a speed sensor for generating a signal corresponding to the running speed of a vehicle, an oil pump driven by an engine, a line pressure adjusting valve for producing a line pressure by adjusting actuating oil from the oil pump to a predetermined hydraulic pressure, a hydraulic pressure adjusting valve for producing a controlled hydraulic pressure acting on the line pressure and adjusting the line pressure to a valve corresponding to the engine load through the line pressure adjusting valve, a hydraulic pressure change-over valve for supplying the line pressure to either one of the friction elements, a circuit for obtaining a corresponding aim line pressure signal from an actually measured load signal obtained from the engine load sensor, a first converter means for converting the target line pressure signal into a target upper limit line pressure signal and a target lower limit line pressure singal which are set above and below the target line pressure signal by given amounts, a line pressure sensor for generating an actually measured line pressure signal corresponding to the line pressure, a second converter means for converting the actually measured line pressure signal from the line pressure sensor into an actually measured upper limit line pressure signal and an actually measured lower limit line pressure signal which differ therefrom by given amounts, respectively, and a decision circuit for generating a signal applied to the hydraulic pressure adjusting valve by decreasing the line pressure when the actually measured lower limit line pressure signal exceeds the target upper limit line pressure signal by comparing the target upper limit pressure signal with the actually measured lower limit line pressure signal and generating a signal applied to the hydraulic pressure adjusting valve for increasing the line pressure when the actually measured upper limit line pressure signal is lower than the target lower limit line pressure signal by comparing the target lower limit line pressure signal with the actually measured upper limit line pressure signal.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram showing a vehicle speed control system of an electronic control type automatic transmission;
FIG. 2 is a diagram showing a line pressure control system used in the system shown in FIG. 1;
FIG. 3 is a characteristic diagram showing the variation of an actually measured line pressure signal with pressure in a diaphragm device;
FIG. 4 is a characteristic diagram showing the variation of an engine load signal with throttle opening;
FIG. 5 is a characteristic diagram showing the variation target line pressure with engine load;
FIG. 6 is the block diagram showing a construction of a line pressure control device according to the present invention;
FIG. 7 is a diagram showing a dead zone set for target line pressure;
FIG. 8 is a diagram showing how to obtain the deviation of the actually measured line pressure from the target line pressure;
FIG. 9 is a diagram showing a pulse signal for driving a solenoid valve in accordance with the deviation;
FIG. 10 is a circuit diagram showing an embodiment of the line pressure control device according to the present invention constructed as an analog circuit;
FIG. 11 is a diagram showing how to obtain a pulse signal for driving a solenoid valve in accordance with the deviation;
FIG. 12 is a block diagram showing the line pressure control device according to the present invention constructed by using a microcomputer;
FIGS. 13 to 15 are flow charts showing the control programs of the line pressure control device shown in FIG. 12;
FIG. 16 is a schematic diagram showing a solenoid driving pulse signal; and
FIG. 17 is a graph representing a table of the target line pressure values corresponding to the divided values of an input signal representing throttle opening degree.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings preferred embodiments of a line pressure control device of an automatic transmission according to the present invention will be explained.
FIG. 6 shows the fundamental construction of a line pressure control device according to the present invention. A signal representing the degree of throttle opening degree corresponding to the engine load from the throttle sensor 7 is converted into a target line pressure signal representing the ideal line pressure by a converter circuit 13. The target line pressure signal is produced by the converter 13 from the signal representing the degree of throttle opening in accordance with the graph of FIG. 5 or the line a in the graph of FIG. 7. The target line pressure signal is supplied to an arithmetic circuit 14. The arithmetic circuit 14, as shown by b and c in FIG. 7, provides a dead zone C with a predetermined width on both sides, i.e. at the + side and the - side of the target line pressure signal. The arithmetic unit adds a value to the target line pressure signal and subtracts a value from the target line pressure signal to determine the dead zone limits. These values to be added and subtracted are determined from a table look-up for the target line pressure signal. In this manner the dead zone having a certain width on both sides of the target line pressure signal is set, so that the arithmetic circuit 14 generates a target upper limit line pressure signal (for example, b') and a target lower limit line pressure signal (for example, c') in accordance with each throttle opening degree (engine load).
The actually measured line pressure signal from the line pressure sensor 5 is supplied to an arithmetic circuit 15, where a dead zone having a certain width on both sides of the actually measured line pressure signal is provided in the same manner as in the arithmetic circuit 14, and the arithmetic circuit 15 generates an actually measured upper limit line pressure signal and an actually measured lower limit line pressure signal.
The target upper limit line pressure signal from the arithmetic circuit 14 is compared with the actually measured lower limit line pressure signal from the arithmetic circuit 15 by a comparator 16. The target lower limit line pressure signal from the arithmetic circuit 14 is compared with the actually measured upper limit line pressure signal from the arithmetic circuit 15 by a comparator 17. The respective comparators supply signals indicating which input signal is large, small or equal to a decision circuit 18. The decision circuit 18 receives signals from both the comparators 16 and 17, and when the actually measured lower limit line pressure signal becomes larger than the target upper limit line pressure signal (when the actually measured lower limit pressure signal enters region B shown in FIG. 7 ), that is, when the actually measured lower limit line pressure exceeds the dead zone of the target value, the decision circuit 18 generates a signal to a control circuit 19 for opening the negative pressure solenoid valve 9. When the actually measured upper limit line pressure signal becomes smaller than the target lower limit line pressure signal (when the actually measured upper limit pressure signal enters region A shown in FIG. 7), that is, when the actually measured upper limit line pressure falls below the dead zone of the target value, the decision circuit 18 generates a signal to a control circuit 30 for opening the atmospheric pressure solenoid valve 10. The decision circuit 18 closes both the solenoid valves 9, 10 in other regions (when either one of the actually measured upper limit or lower limit line pressures is in the dead zone C). Thus, the line pressure is adjusted to the target value (refer to FIG. 5) corresponding to the engine load by such control of the solenoid valves 9, 10 as described above. The dead zones are set on both sides for both the target value and the actually measured value in this case, so that the over shoot of the diaphragm 4B (refer to FIG. 2) is not produced in any direction. Thus, consuming power of the solenoid valves 9, 10 can be decreased by stabilizing the control system, the negative pressure of the vacuum tank 12 is not wastefully consumed, and there is no deviation of the target value.
The target line pressure signal from the converter circuit 13 and the actually measured line pressure signal from the line pressure sensor 5 are also supplied to a deviation arithmetic circuit 31. The deviation arithmetic circuit 31 compares the target line pressure with the actually measured line pressure from both the applied signals and determines the difference or deviation. The circuit 31 supplies a signal representing the magnitude of this deviation to the control circuits 19, 30. For example, if, as shown in FIG. 8, the throttle opening is TH and the actually measured line pressure is d, then the circuit 31 will produce an output signal representing the deviation δ. A clock signal generator 32 supplies a reference time T A shown in FIG. 9 to the control circuits 19, 30. These control circuits determine an ON time T B of a duty cycle as shown for example in FIG. 9 in accordance with a predetermined function of the deviation δ, and the solenoid valves 9, 10 are opened during the ON time only. The control circuits 9, 10 determine the opening time of the solenoid valves 9, 10 in the above described operation, respectively, in a duty cycle in which the larger the deviation δ, the longer the opening time T B of the solenoids 9, 10, while the smaller the deviation δ, the shorter the opening time T B of the solenoids 9, 10, so as to precisely carry out the operation and to improve its response. In this method the difference between the actually measured line pressure and the target line pressure, which is within the dead zone, is determined as the deviation, so that this deviation becomes a precise reference value for promptly bringing the actually measured line pressure into the dead zone, and the object for improving the response of the control system can positively be attained.
FIG. 10 shows a constructional embodiment of the device according to the present invention by using an analog circuit. An engine load signal V T (throttle opening degree signal) from the throttle sensor 7 (refer to FIGS. 2 and 6) supplied to a terminal 33 is converted into a target line pressure signal V T ', in accordance with the graph shown in FIG. 5 and designated a in FIG. 7, by a converter circuit 34. This target line pressure signal V T ' is added to a voltage V e by an adder 35 to become an target upper limit line pressure signal (refer to b in FIG. 7) of V T '+V e , and a subtractor 36 subtracts a voltage V f from the signal V T ' to become an target lower limit line pressure signal (refer to c in FIG. 7) of V T '-V f . Therefore, the target line pressure signal V T ' sets the dead zone C shown in FIG. 7 on both sides thereof, i.e. at the + side and the - side thereof.
An input terminal 37 receives an actually measured line pressure signal V q (refer to e in FIG. 3) from the line pressure sensor 5 (refer to FIGS. 2 and 6). This actually measured line pressure signal V q is added to a voltage V g by an adder 38 to become an actually measured upper limit line pressure signal (corresponding to f in FIG. 3) of V q +V g , and a voltage V h is subtracted from V q by a subtractor 39 to become an actually measured lower limit line pressure signal (refer to g in FIG. 3) of V q -V h . Therefore, the actually measured line pressure signal V q sets a dead zone h shown in FIG. 3 on both sides thereof, i.e. at the + side and the - side thereof.
The target upper limit line pressure signal V T '+V e and the actually measured lower limit line pressure signal V q -V h are supplied to a comparator 40', and the target lower limit line pressure signal V T '-V f and the actually measured upper limit line pressure signal V q +V g are supplied to a comparator 40. The comparator 40' generates a signal with the amplitude level (H) when V q -V h >V T '+V e , and the comparator 40 generates a signal with the amplitude level (H) when V q +V g <V T '-V f . Both the comparators 40' and 40 generate a signal of the low amplitude (L), respectively, when the above conditions do not occur.
The target line pressure signal V T ' and the actually measured line pressure signal V q are supplied to a comparator 41, where both the signals are compared with each other, and a signal V a corresponding to the deviation δ of the actually measured line pressure from the target line pressure is generated, and this signal V a is supplied to a comparator 42. The comparator 42 receives a saw-tooth wave or triangular wave shown in FIG. 11 (iii) from a waveform generator 43. The comparator 42 compares this waveform with the deviation signal V a , and the comparator produces a high signal level output (H) whenever the sawtooth signal amplitude is greater than the amplitude of the deviation signal V a and produces a low signal level output (L) whenever the sawtooth signal amplitude is less than the amplitude of the deviation signal. Thus, if the deviation signal V a is low (the deviation δ is small) for example shown by V a1 in FIG. 11 (iii), a pulse signal shown in FIG. 11 (i) is supplied to AND gates 44, 45, while if the deviation signal V a is high (the deviation δ is large) for example shown by V a2 in FIG. 11 (ii), a pulse signal shown in FIG. 11 (ii) is supplied to the AND gates 44, 45.
The AND gates 44, 45 receive signals from the comparators 40', 40, and the corresponding AND gate 44 or 45 generates the pulse signal when a signal from the comparator 40' or 40 is at the H level. This pulse signal is inverted by connecting inverters 46, 47 to output terminals of the AND gates 44, 45 because the larger the deviation signal V a (deviation δ), the longer the time of the L level at the output of the AND gates 44, 45. The converters 46, 47 make the time of the H level longer and the time of the L level shorter as the deviation signal V a (deviation δ) increases.
The inverted pulse signal is supplied to the bases of transistors 48, 49, which act as switches controlling current to the coils 9a, 10a of the negative pressure solenoid valve 9 and the atmospheric pressure solenoid valve 10. The transistors 48, 49 are rendered conductive during intervals corresponding to the H level of the pulse signal so as to open the solenoid valves 9, 10.
As described above, the line pressure control device according to the invention shown in FIG. 10 can open the negative pressure solenoid valve 9 during the H level interval of the pulse signal corresponding to the magnitude of the deviation signal V a , which in turn corresponds to the deviation δ when the actually measured lower limit line pressure signal V q -V g exceeds the target upper limit line pressure signal V T '+V e , so as to promptly and precisely decrease the line pressure to the target value as described in the above embodiment, and can open the atmospheric pressure solenoid valve 10 during the L level interval of the pulse signal corresponding to the magnitude of the deviation signal V a , which in turn corresponds to the deviation δ when the actually measured upper limit line pressure signal V q +V g is lower than the target lower limit line pressure signal V T '-V f , so as to promptly and precisely increase the line pressure to the target value as described in the above embodiment.
The device according to the present invention shown in FIG. 10 can set dead zones on both sides for the target value and the actually measured value, so that a difference between the actually measured line pressure and the target line pressure, which is within the dead zone, can be used as the deviation, and the same function and effect described in reference to FIG. 6 can be obtained.
FIG. 12 shows an embodiment of the device according to the present invention constructed by using a microcomputer. The device in this embodiment comprises a microprocessor (MPU) 50, an input/output interface circuit (PiA) 51, a read only memory (ROM) 52 and a random access memory (RAM) 53. The control program shown in FIG. 13 is stored in the memory of the ROM 52, thereby to effect digital controlling which will be explained below. An actually measured line pressure signal (analog signal) and a throttle opening degree (engine load) signal (analog signal) from the line pressure sensor 5 and the throttle sensor 7 are converted into digital signals, respectively, by A/D converters 54, 55, and supply to the PiA 51.
The MPU 50, first in blocks 101, 103 shown in FIG. 13, reads out an actually measured line pressure signal and a throttle opening degree signal from the PiA 51 at regular time intervals of duration t A as determined by a timing signal (pulse signal or level change signal). Time interval t a is determined from a time interval t B derived from a timer 56. The MPU 50 writes the actually measured line pressure signal and throttle opening degree signal in the RAM 53. As a result, the throttle opening degree signal and the actually measured line pressure signal are supplied to the RAM 53 every time interval t A which can be variably set at the program. While it is common to use the signal from the timer 56 as an interruption signal and to carry out a constant timing function by the MPU 50 in response to the timing signal, it is also possible to generate a signal similar to that provided by the timer 56 by means of a software timer in the MPU 50 in order to provide constant time functions.
In a block 102 the MPU 50 determines which divided value (e.g., 1 through 7 as shown in FIG. 17) the input value of the throttle opening degree stored in the RAM 53 corresponds to. This determination is carried out by the control program shown in FIG. 14 as follows. Initially, in a block 301, the previously determined divided value (stored in the memory position DIV of the RAM 53) is reset to zero. Then, in a block 302, a predetermined value corresponding to a division width is subtracted from the input throttle data value, and the resulting difference value is stored in the memory position DATA of the RAM 53. This value is compared with zero in a block 303. If, for example the input throttle data corresponds to the divided value 2, the difference value will be larger than zero, so that the control program proceeds to a block 304 in which the value 1 is set in the memory DIV of the RAM 53. The control program then returns back to the block 302 again, so that the predetermined value is again subtracted from the above mentioned difference value stored in the RAM 53, and the new difference value is stored in the RAM. This difference value is compared with zero in the block 303, and in the above mentioned example wherein the throttle data corresponds to the divided value of 2, the difference value will be still larger than zero, so that the value 2 is set in the memory position DIV of the RAM 53 in the block 304. The control then again returns to the block 302. The predetermined value is then again subtracted from the previous difference value stored in the RAM 53. In case of the above mentioned example, the subtracted result will become smaller than zero, so that the control proceeds to block 305 from the block 303. In block 305, the value previously stored in the memory device DIV of the RAM 53, is read out as the divided value. In the case of the above mentioned example, the value 2 is read out as the divided value.
In accordance with the thus determined divided value, from a table of the target line pressure values previously stored in the ROM 52, the corresponding target upper limit line pressure value and the target lower limit line pressure value are read out by a table lookup system, respectively. FIG. 17 is a graph representing the table target line pressure values corresponding to the divided values determined for the throttle opening degree. Therefore, a dead zone (TH max -TH min ) having a predetermined width on both sides of the target line pressure signal can be obtained.
In the block 104 of FIG. 13, in the same manner that the dead zone is provided for the target line pressure value as described above a dead zone is provided for the actually measured line pressure value PL read out from the RAM 53. From a table of the actually measured line pressure previously supplied to the ROM 52, the corresponding actually measured upper limit line pressure value PL max and the actually measured lower limit line pressure value PL min are read out by a table lookup system and a dead zone (PL max -PL min ) having a predetermined width on both sides is also set for the actually measured line pressure signal. An alternative system of setting this dead zone, would be to use a system of subtracting a predetermined value from a read-in data value instead of the above described table lookup system. The latter system, however, is inconvenient because the same dead zone is always set to the read-in data value. On the other hand, the formersystem is advantageous because the dead zone width can freely be varied for every read-in data value according to the setting.
In the block 105 then, the signals TH max and PL min obtained as described above are compared with each other, and when PL min >TH max , the program control proceeds to the block 106 and a negative pressure intake routine is performed, which will be explained with reference to FIG. 15 below. When PL min <TH max , the control proceeds to a block 107, where TH min is compared with PL max , and when PL max >TH min , that is, when the actually measured upper limit line pressure is greater than the target lower limit line pressure, the control program proceeds a block 108, so as to close both the solenoids 9, 10 (refer to FIG. 2) and not to change the line pressure by keeping the present pressure in the chamber 4A of the diaphragm device 4 (refer to FIG. 2). When PL max <TH min , the control program proceeds to a block 109 and an atmosphere intake routine, which will be explained below, will be carried out. At the same time when the blocks 106, 109 are selected by the blocks 105, 107, respectively, the line pressure control flag PL FLAG is set to 1, and PL FLAG is reset to 0 when the block 108 is selected.
The negative pressure intake routine will be explained with reference to FIG. 15.
When an interruption signal is delivered at each time interval t B from the timer 56 (refer to FIG. 12), the execution is started. In block 201, it is detected whether PL FLAG is 1, that is, whether the negative pressure intake routine has already been started when the negative pressure intake instruction from the block 105 shown in FIG. 13 occurs, the PL FLAG will be set at 1. When the PL FLAG is 1 the control program proceeds to a block 202, and it is determined whether the reference time T A is zero or not. Assuming that the time T A is a numerical value corresponding to a certain time interval times the predetermined time interval signal from the timer 56 (refer to FIG. 12) and this value T A is equal to the afore-mentioned time interval t A for the sake of, for example, is equal to 4 as shown in FIG. 16, then T A ≠0 initially. Accordingly the control program proceeds to a block 203, where T A -1=3 is calculated and this value is stored in the RAM 53. Then, in a block 204, it is determined whether the time interval T B for switching on the negative pressure solenoid valve is zero or not. The time interval T B is a negative pressure intake time determined in accordance with the deviation δ from the negative pressure intake time table corresponding to the magnitude of the deviation δ previously stored in the ROM 52. Assuming that T B is equal to the above-mentioned time interval t B for the sake of simplicity and is equal to 1, for example, as shown in FIG. 16, then, T B ≠0 initially. Accordingly the control program proceeds from the block 204 to a block 205, where T B -1=0 is calculated, and the calculated value is stored in the RAM 53 and a driven signal for the negative pressure solenoid valve 9 is generated from in block 206.
When the next interruption signal is delivered from the timer 56, it is again determined whether PL FLAG is 1 or not in the block 201, and whether T A is zero or not in the block 202. In the above described example, T A is 3 from the preceding step and T B is 0 from the preceeding iteration through the routine, so that the control program proceeds to the block 207, where the signal for driving the negative pressure solenoid valve to its OFF state is generated. Thus, the negative pressure solenoid valve driving signal, which is generated from the block 206, is maintained for a time interval in accordance with the deviation δ, for example, for an interval T B =1 as shown in FIG. 16. Drive circuit 57 shown in FIG. 12 is actuated in accordance with the signal and the negative pressure solenoid valve 9 is opened for time interval equal to T B . The control program thereafter repeats from the block 202 to 203, 204, 207 until T A becomes zero completing this cycle. At the next time t.sub. A the cycle is similarly repeated until PL FLAG is reset to 0 at the block 108. In this manner the opening and closing operation of the negative pressure solenoid valve 9 is controlled.
The atmospheric pressure intake routine 109 shown in FIG. 13 is carried out in the same manner as the afore-mentioned negative pressure intake routine. The atmospheric pressure solenoid valve 10 is opened by the drive circuit 58 shown in FIG. 12 by a similar method so that opening time of the valve 10 controlled in accordance with the deviation δ.
In the embodiment, of FIG. 12 the dead zones are provided on both sides of the target line pressure value and the actually measured line pressure value. The target line pressure and the actually measured line pressure as values are compared with each other and their difference is used as a deviation, so that function and effect similar to the previously described embodiments can be obtained.
In every one of the above embodiments, the dead zones are provided on both sides of the target line pressure and the actually measured line pressure. Alternatively dead zones may be provided on both sides of only one of the target line pressure or the actually measured line pressure, and the objects of the invention can be attained. However, in the described embodiments with the dead zones provided on both the target line pressure and the actually measured line pressure and wherein the upper limit value is compared with the lower limit value, which values determine the dead zones, it becomes possible to reduce the dead zone widths to the half the width that would otherwise be required and the stability of the control system can be maintained while maintaining the line pressure control with high precision. With a dead zone provided on only one of the target line pressure and the actually measured line pressure it is necessary to make the dead zone width twice as wide in order to positively attain, can be stability of the control system. But such a system has the disadvantage that control precision of the line pressure is reduced by half as compared with the above described preferred embodiments. When this fact can be ignored, the latter control device is advantageous because one system for setting a dead zone for the target line pressure signal or the actually measured line pressure signal can be omitted, and thus the control system can be simply constructed with minimum expenses. | In a line pressure control device of an automatic transmission for vehicle a circuit is provided for generating a target line pressure signal corresponding an actually measured load signal obtained from an engine load sensor. A line pressure sensor generates an actually measured line pressure signal corresponding to the line pressure. A converter converts the target line pressure signal and the actually measured line pressure signal into upper limit line pressure signals and lower limit line pressure signals which are set given amounts above and below the target signal and the actually measured signal respectively. A decision circuit compares the upper and lower limit line pressure signals drives and properly driving and controls the hydraulic pressure adjusting valve in accordance with the result of the comparison. | 5 |
BACKGROUND OF THE INVENTION
This invention relates to a spool valve having throttling slots which are required to be in alignment with certain ports in the encompassing housing. This results in a requirement to prevent rotation of the valve spool within the housing. The invention relates in particular to a valve spool which fulfills the above criteria and which is pilot operated.
Spool valves which are manufactured with throttling slots in the spool thereof to communicate a groove in the housing with the next adjacent groove under controlled conditions are well known in the art. Generally the grooves in the housing are annular and spool alignment is not critical. Certain spool valves are constructed with throttling grooves which require alignment with ports communicating with a land in the bore of the valve rather than with a groove defined in the bore. Valve spools of the configuration just described are known to be manually controlled by means of a linkage which prevents rotation of the valve spool in the housing thus maintaining the critical alignment. In certain applications it has been found desirable to operate this same valve not by a control lever but by pilot pressure from a remote location.
Normally pilot operated valves are constructed with a cylindrical shaped pilot chamber wherein the pilot fluid is applied against one end or the other end of the valve spool to urge the spool in desired direction. Generally if the spool rotates during reciprocation in the associated housing, no undesirable results occur. However, in the present situation rotation must be prevented. To extend a noncircular portion of the valving spool into a pilot chamber and further to seal the pilot chamber against leakage proves difficult in view of the noncircular nature of the opening due to the inherent problem of machining noncircular openings. This machining problem coupled with the necessity for close tolerances and providing for seal means in the pilot chamber to prevent leakage, makes the problem more difficult. To add an actuator motor to the control lever of manually controlled valves, although providing a satisfactory solution, unduly complicates the problem and adds weight to the associated machinery.
SUMMARY OF THE INVENTION
The present invention is directed to overcoming one or more of the problems as set forth above.
Broadly stated, the invention is a pilot operated spool valve comprising an elongated housing defining an axial bore and a first radial port communicating with the axial bore. A valve spool reciprocally mounted therein defines axial slots alignable with the first radial port with the valve spool resiliently biased to a first position. A first end member is affixed to the housing to close one end of the axial bore. The first end member defines therein an axially aligned first pilot chamber. The spool is formed with an axially extending noncircular tang formed to fit in a tang cavity defined in the first end member and having generally the same cross-sectional shape as the noncircular tang. The first end member is sealingly associated with the housing while the spool is sealingly associated with the axial bore of the housing proximate the first end to form a substantially fluid tight pilot chamber.
The aforesaid objects and others will become apparent from a study of the accompanying drawings and the following specification.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a valve and valve spool, shown partly in section, of the type wherein rotation of the valve spool is critical, and incorporating the structure of this invention.
FIG. 2 is a view of the end member taken at line II--II of FIG. 1 and showing the shape of the pilot chamber which prevents rotation of the valve spool.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
A spool valve 10 of the type requiring means to prevent rotation is illustrated in FIG. 1. Spool valve 10 is shown in relation to a hydraulic motor means, in particular, a double acting cylinder 12 for operating a work implement 14. A reservoir 16 contains unpressurized fluid which is withdrawn therefrom and pressurized by means of a pump such as variable pressure pump 18. The pressurized fluid is communicated by means of a conduit 19 to a branching passage 20, defined in housing 21 of spool valve 10.
Rotation of spool 22 in bore 23 must be prevented in view of alignment of slots 24 and 27, with passages 25 and 26 respectively in the housing 21. The purpose of these slots will become apparent, however other features of this valve structure should be understood first. Housing 21 is formed with a centrally located inlet chamber 28 in communication with branching passage 20. Adjacent to inlet chamber 20 are first and second service chambers 29 and 30 in communication respectively with the head end and the rod end of double acting cylinder 12. Movement of spool 22 to the right as indicated in FIG. 1 communicates inlet chamber 28 with service chamber 29 and thus the head end of double acting cylinder 12. Simultaneously service chamber 30 which is in communication with the rod end of double acting cylinder 12 is placed in communication with a drain chamber 31 formed in the housing 21. A similar drain chamber 32 is formed at the other opposite end of housing 21 to drain the head end of the double acting cylinder 12 when the spool is moved in the other opposite direction. The spool 22 is formed with appropriate lands to separate the aforedescribed chambers. These lands define a plurality of metering grooves 33 for modulation of the pressure between inlet chamber 28 and the working chambers of the double acting cylinder 12.
Forming a part of the flow compensation valve design is the dump valve 35. Dump valve 35 is comprised of a bore 36 in which a reciprocally mounted sleeve 37 is resiliently urged toward one end by a resilient member 38 disposed in bore 36 distal of spool valve 10 between sleeve 37 and a first end 39 of bore 36. Branching passage 20 communicates with the other end of bore 36 so that with pressure applied in branching passage 20 sleeve 37 is urged toward first end 39 against the bias of resilient member 38. Sleeve 37 is formed with a plurality of radial bores 40 which communicate with a conduit 41 when sleeve 37 is urged toward first end 39. A passage 42 communicates first end 39 of dump valve 35 with passages 25 and 26 in spool valve 10. A resiliently biased relief valve 46 is provided in a conduit 47 communicating with passage 42.
Slots 24 and 27 are particularly oriented to communicate with passages 25 and 26. Reference to FIG. 1 will indicate throttling grooves 33 would overlap slots 24 and 27 and act contrary to the purpose of these slots if spool 22 were allowed to rotate in bore 23. Slots 24 and 27 communicate passages 25 and 26 to drain chamber 32 or 31 respectively with the spool in the neutral position as shown. With the spool moved to the right in FIG. 1, pressure communicated to service chamber 29 via throttling grooves 33 is further communicated through slot 24 to passage 25 so that this pressure acting in cooperation with resilient member 38 urges sleeve 37 downwardly blocking communication between passage 20 and drain conduit 41 to maintain pressure communicated to the head end of the double acting cylinder 12. At the same time the slot 27 with the valve spool moved rightwardly is moved out of communication with passage 26.
In order to maintain the orientation of spool 22, the spool is formed with an axially extending noncircular tang 51. Housing 21 is adapted to receive end cover 53 formed with a tang cavity 54 to receive a noncircular tang 51. End cover 53 serves not only to prevent rotation of spool 22 by the tang 51 fitting into tang cavity 54 but also serves as a housing for a pilot chamber used to urge valve spool 22 leftwardly as viewed in FIG. 1. This is accomplished through a passage 56 communicating with cavity 54 through which fluid may be applied to cavity 54. End cover 53 sealingly engages housing 21 along a surface 58 of housing 21. Appropriate sealing means may be disposed therebetween. End cover 53 and housing 21 are kept in alignment by at least two mating pins 59 and 60 which are formed to be received in aligned bores in housing 21 and end cover 53 so that with tang 51 disposed in cavity 54 proper alignment is maintained between slots 24 and 27 and ports 25 and 26.
A second pilot chamber 65 is provided at the other opposite end of housing 21, and includes a second end cover 75 and double acting resilient means 68 to bias valve spool 22 to a mid or neutral position. Resilient means 68 is formed with a helical spring member 69 engaged in a spring retainer cup 70 adjacent valve spool 22 and a similarly formed spring retainer cup 71 adjacent pilot chamber 65. Spring retainer cup 70 and spring retainer cup 71 extend axially toward one another leaving a sufficient gap therebetween so that valve spool 22 may be urged either rightwardly or leftwardly as indicated in FIG. 1. This gap is sufficient to allow proper communication of slots 24 and 27 with the appropriate grooves in the housing for operation of the valve spool.
A passage means 74 is provided in the second end cover 75 in which pilot chamber 65 is formed, passage means 74 provides fluid to pilot chamber 65 from a pilot fluid source.
In operation, fluid under pressure is communicated from a pilot fluid source 77 to either passage 56 or passage 74 to urge spool 22 leftwardly or rightwardly as the case may be. Rotation of tang 51 on movement in either direction of the spool is constrained by the shape of the pilot chamber. By constraining rotation of tang 51, slots 24 and 27 remain in alignment with passages 25 and 26 respectively.
A secondary advantage is that the tang 51 may include a transverse hole 62 for a mechanical linkage. With the substitution of a spring 69 with a spring having a lower spring rate, the valve may then be mechanically shifted for test purposes; or with a special end housing (which retains the non-rotation features) the valve may be altered for mechanical actuation from an operator's station. | A pilot operated valve comprised of a cylindrical grooved spool having axially aligned throttling slots which require alignment with certain ports in an encompassing housing is prevented from rotation in the housing during reciprocation therein by a noncircular tang extending outwardly of the housing and fitted in a specially configured pilot chamber formed in an attached cover. | 5 |
RELATED PATENT APPLICATIONS
This application is a continuation-in-part of previously filed U.S. patent application Ser. No. 07/532,139, filed Jun. 4, 1990, entitled "Electric Motor Control System," now abandoned, which was a continuation of previously filed U.S. patent application Ser. No. 07/237,044, filed Aug. 29, 1988, entitled "Electric Motor Having A Microcomputerized Control System," now abandoned.
FIELD OF THE INVENTION
The invention relates to peak current control within the armature of a DC motor during high current conditions and more particularly to limiting the peak currents in the armature of a DC motor of a material handling vehicle during all operational conditions including plug-braking.
BACKGROUND OF THE INVENTION
Fork lift trucks and other material handling vehicles place great strain upon their motor systems during hard braking and maximum accelerating and decelerating conditions. It is during these operational conditions that the DC motor of the fork lift vehicle experiences peak current conditions in the armature. It is important to limit the peak currents flowing through the DC armature in order to reduce heating therein and to improve the efficiency of the operation of the fork lift truck.
It is most common to apply plug-braking in DC motors used in material handling vehicles. Such a technique is illustrated in U.S. Pat. No. 3,826,962, issued to Morton et al on Jul. 30, 1974, entitled "Control of Electric Motors for Battery-Operated Vehicles." This system avoids overheating when "regeneration" or plug-braking is utilized. A coil is used to sense plugging current which is then used to energize a contactor. The field current is regulated to keep the generated current constant as motor speed slows, thereby providing constant braking torque. In the DC motor of this patented system, the heating effects are small. This is particularly true when contrasted to DC motors employed in fork lift truck operations.
When a fork lift vehicle plug-brakes, it brings a 12,000 pound vehicle to a stop in an average of three seconds. This dynamic stopping condition equates to 19,750 ft-lbs of energy, or 26,800 joules. This energy must be dissipated almost entirely in the armature circuit. This is a great amount of energy to be dissipated and would ordinarily cause severe heating in the armature of the DC motor, were it not for the present invention.
It should also be observed that the aforementioned braking condition of the vehicle is on the average occurring 100 times every hour of operation. When this enormous amount of heat energy is also accompanied by other losses during normal driving and acceleration, it is no wonder that this serious problem must be eliminated or at least effectively controlled.
The present invention controls peak armature DC motor current during the entire operation of the vehicle, one hundred percent of the time. A current sensor is utilized to provide both magnitude and polarity of armature current. A processor utilizes this information to control both a switching contactor and pulse switching means at an accelerated rate that only computer processing can handle. The inventive control system eliminates or removes as much heat from the armature during plug-braking as possible and yet provides an adequate braking effort to the vehicle.
In prior art systems, velocity control or constant braking force limitations have been placed upon the operational system to improve efficiency of the operation. However, none of these systems has regulated current through the armature of the DC motor for the purposes of this invention, viz., protecting the armature from overheating. A prior art system that used velocity feedback to regulate applied power for acceleration and deceleration is shown in U.S. Pat. No. 3,466,524, issued to Cooper on Sep. 9, 1969, for a "Speed Taper Brake Modulation System." In this system, the braking effort is controlled as a function of speed. A special motor with an extra winding is utilized for controlling motor impedance and thus current. This is equivalent to a variable speed DC motor system.
In the aforementioned patent to Morton et al, the contactor and resistor control is analogous to an on/off light switch. By contrast, the present invention utilizes an SCR dimmer control. Whereas the Morton et al system merely switches on and off depending upon the presence of plugging current, the present invention senses the motor current with its polarity changes almost instantly. The invention uses this information to switch the contactor "cold", with little or no current passing through the tips. The plugging current is directed through a resistor. The pulse width and frequency of the current is precisely varied at the SCR switch to regulate the current through the armature.
The advantages of the present invention are that 75 to 80% of the energy once dropped in the armature is now dissipated by the system's external resistor during plug-braking. This greatly reduces the operating temperature of the motor, which experiences this braking condition on the average of 100 times per hour.
Contactor tip wear is also greatly reduced due to precise switching of the contactor as a function of armature current, wherein little or no current passes through the tips during the braking.
The system removes the resistor from the circuit during conditions that do not require plug-braking. This increases the recirculating current during normal acceleration and driving. The result is that the delivered net torque of the motor is improved. Thus, the entire system is more efficient over its entire operation.
SUMMARY OF THE INVENTION
In accordance with the present invention, there is provided an electric motor control system comprising in combination at least one electric motor having a field winding and an armature winding connected in series. The system also comprises a first power terminal, a second power terminal, a current-limiting resistor, and a current sensor. The current-limiting resistor and the current sensor are connected in series between the first power terminal and the second power terminal. A contactor has a contact operable to shunt the current-limiting resistor. A microcomputerized control operatively connected to the contactor and the current sensor governs the contactor to shunt the current-limiting resistor when the electric motor is not in a plugged condition. The contactor is operative when the current sensor detects a substantially zero current through the electric motor. The microcomputerized control continuously regulates power being supplied to the electric motor and provides optimum armature current in all operative modes of the electric motor including a braking mode. This results in smooth braking that is accomplished with a minimum of armature heating.
BRIEF DESCRIPTION OF THE DRAWINGS
A complete understanding of the present invention may be obtained by reference to the accompanying drawings, when considered in conjunction with the subsequent detailed description, in which:
FIG. 1 is a schematic circuit diagram illustrating one form of prior art plugging circuits;
FIG. 2 is a schematic circuit diagram of an improved plugging circuit according to a first embodiment of the invention;
FIG. 3 is a schematic diagram showing the motor control circuit of a prior art system;
FIG. 4 is a schematic diagram showing the motor control circuit of FIG. 3, modified to incorporate the present invention; and
FIGS. 5, 6 and 7 taken together provide a schematic diagram illustrating a preferred embodiment of the present invention comprising an electric motor control circuit including a microcomputer.
Similar reference characters refer to similar parts in each of the several views.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1 of the drawings, there is shown an elementary electric motor circuit including a series connected field winding FW and an armature AR, connected in series between a source of pulsed direct current having terminals designed as + and -. A current-limiting resistor CLR is connected across the armature via a first plugging diode RC1, and resistor CLR is connected across the armature and the field winding via a second diode RC2. In this arrangement, the resistor CLR is permanently connected to the motor circuit. Hence it not only limits the plugging current but also limits the recirculating or "free-wheeling" current which flows through the plugging diodes. The torque boost that the motor receives when the motor field collapses after the removal of each pulse through the motor is reduced because the resistor reduces the current. The net effect is to reduce the response of the system and to produce a greater amount of wasted heat energy. The limiting resistor CLR may be eliminated if the resistance of the wire connections alone is adequate to limit the plugging current.
FIG. 2 shows the resistor CLR wired in series with the armature and the field winding and selectively shunted by a contact 1Sb of a heavy-duty contactor. Thus the resistor CLR is placed in the plugging and recirculating circuit paths but it is effectively switched out by contact 1Sb when the system is in its normal operating mode. The resistor and shunting contact are equally effective in the circuit branch to diodes RC1 and RC2. This arrangement maximizes the torque boost from the collapsing fields after each current pulse and also reduces the wasted heat energy. When plugging is required, the contactor opens its contacts and the shunt is removed from resistor CLR, thereby placing the resistor in the circuit. The contact operating mechanism CM which may be a conventional solenoid, for example, is governed by a control circuit CON which receives signals from a current sensor IS. The contacts such as 1Sb are thus opened and closed only when the motor current is at or near zero, thus substantially reducing the wear or erosion of the contacts caused by operations while conducting heavy currents.
A prior art control circuit is shown in FIG. 3. Operation of the circuit thereshown need not be described herein in detail. In brief, two series-field motors M1 and M2 are connected in parallel with each other and in series with a battery B and a pulse-width modulated thyristor SCR1. The series fields F1 and F2 of the motors are switched to determine motor torque direction. When thyristor SCR1 is turned on, current flows from battery B through the motor fields and motor armatures and through thyristor SCR1. When thyristor SCR1 is turned off, by energizing commutating thyristor SCR2, the inductive flux collapse in the motors causes current flow through "free-wheeling" diode XR3. That current flow significantly contributes to motor torque and motor efficiency.
When plugging occurs, large currents circulate in two loops which include diode XR1, relay coil K1 and armature A1 as one loop; and diode XR2, relay coil K2 and armature A2 as the other loop. The use of such plugging loops decreases the amount of battery power which otherwise would be used during plugging. It lessens the amount of commutating capacity required and thereby decreases expense. It causes plugging torque to vary less drastically with motor speed.
The normally-closed contacts of shorting contactor 1S are held open during normal running but are made to close during plugging when the two motors are acting as two series-field generators, for reasons of stability. Series-field generators cannot be safely connected in parallel without an interconnection of the type provided by the contacts 1S. De-energization of the 1S contactor coil occurs in response to sufficient current flowing through the coil of plugging relay K1 or through the coil of plugging relay K2. The large currents which circulate in armatures A1 and A2 during plugging often tend to cause severe motor overheating and sometimes damage.
Various simple means for limiting armature current are generally well known. It is readily apparent that one could wire resistors in series with and adjacent to the two armatures in FIG. 3. However, that would disadvantageously tend to waste power both during the "on" time of thyristor SCR1 and during the "off" time while inductive field collapses cause current to circulate through "free-wheeling" diode XR3.
FIG. 4 is a modification of the arrangement shown in FIG. 3, described above, showing the changes required to provide an electric motor control system in accordance with one embodiment of the present invention.
In FIG. 4 a resistor R5 is shown inserted in series between the two armature loops and the main thyristor SCR1. A normally-open contact pair 1Sb is connected to opposite ends of resistor R5. The contact pair 1Sb may comprise an added pair of contacts on the contactor 1S shown in both FIGS. 3 and 4. During normal running the coil of contactor 1S is energized, so that contacts 1Sb are closed, shorting across resistor R5 and effectively removing that resistor from the circuit. Thus it will be apparent that resistor R5 has no effect during normal running and does not interfere with circulation of current through diode XR3. However, while plugging is occurring and contacts 1Sb are open, the insertion of resistor R5 in series in both of the two armature loops clearly decreases the current which circulates in those loops.
The insertion of resistor R5 during plugging decreases the current which flows through the motor armature and the main thyristor SCR1. Hence, the amount of braking torque is decreased from that amount which otherwise is available during plugging with the prior art circuit of FIG. 3. However, that decrease can be easily compensated for by mere adjustment of the thyristor duty-cycles which occur for given control positions during plugging.
The preferred embodiment of the invention is illustrated in FIGS. 5, 6 and 7 arranged in sequence from left to right. The electrical connections between the figures are given corresponding numerical reference characters for matching purposes. This embodiment includes a microcomputer motor controller MC (FIG. 6), which may comprise, for example, part of a Model MS-100 motor controller sold by Sigma Elektroteknisk A/S of Vestby, Norway. The functions provided by the controller MC are shown within the dashed line in FIG. 6. An operator travel control handle TC (FIG. 7) is connected to operate a spring-loaded potentiometer TP within forward and reverse ranges separated by a neutral position. The voltage on the wiper of potentiometer TP is applied to conventional filtering and level-shifting circuits indicated by LS to provide an acceleration request voltage, which is then supplied to the Velocity Control Function VCF.
A feedback voltage from the motor armature(s) (back electro-motive force) is applied via connections 5 and 6 to a Back EMF Detect Function BEMF. It is an analog voltage that varies directly with the rotational speed of the motor(s). The Back EMF Detect Function BEMF receives the tachometer-like signal from the motor(s) and conditions it for further use. The motor voltage can be either positive or negative depending on the operational mode of the system. It is positive when motoring in a normal drive mode; it is negative when the truck is moving in a given direction and plugging to slow the truck to a stop or to change direction.
The velocity control circuit VCF is a velocity feedback summing junction for motor control. If the speed command voltage is less than the motor feedback voltage, no net positive command signal is sent on to the next stage. If the command voltage is greater than the motor voltage, a positive error command signal is sent to the Firing Logic function FL in the microcomputer MC to indicate a need for the SCRs to be pulsed and for more voltage to be applied to the motors.
When the voltage across the motor(s) reverses, the motors are generating current. This condition is detected by the BEMF function. A negative voltage is detected by the Plug Detect function PD and informs the Firing Logic function FL and Diagnostic Monitoring function DM that the vehicle is in the plug mode of operation.
It is important to know when the plugging sequence has started so that the SCRs can be pulsed at a slower rate for a smooth braking action. When traveling in the forward direction, if the operator changes the speed control handle position so that it passes through neutral and into the opposite direction, plugging will occur. The more the handle is moved in the reverse direction, the faster the pulsing rate of the SCRs and the harder will be the braking effort. This is known as proportional plugging.
After the handle moves through neutral into the reverse direction, the forward contactor(s) 1F and 2F will be deenergized under the control of the Contactor Control function CC which controls the contactor operating coils via connections 33, 34, 35 and 36 and the associated driver circuits DR1-DR4. When the current through the motor armature has reduced to zero or very near zero, the reverse contactor(s) 1R and 2R will be energized. The status of the contactors is detected by the Contactor Sensing function CS via the connections 9-12. The polarity of the field reverses. With the existing rotation of the armature from the truck movement, the motor becomes a generator. The braking torque is described by the expression,
T.sub.b =K.sub.t ×I.sub.a
where,
T b =Braking torque
K t =Motor torque constant
I a =Armature current
The current through the armature can be described by,
I.sub.a =-(V.sub.a +V.sub.emf)/R
where,
V a =Applied Armature Voltage
V emf =Rotational Generated Voltage
R=Resistance of the Armature Circuit
To increase the braking effort, the main SCR (SCR1) is pulsed at a slow rate by the outputs from the Pulse Generator function PG via connectors 2 and 3. The Pulse Generator function PG is in turn governed by the Firing Logic function FL which also governs the Contactor Control function CC. The voltage V a supplied to the armature adds to the voltage generated from the rotating armature V emf . The higher voltage generates a larger current I a and therefore more braking torque T b . The value of resistance can be increased with an external component resistor. The greater the resistance the less the current. However this can be balanced against the duty cycle of SCR1 to apply a greater voltage V a . Therefore, by balancing the resistor sizing against the SCR1 duty cycle, an optimum combination can be found that gives smooth braking effort and reduces armature heating.
With this design, a resistance of 0.030 ohms (two times the armature resistance of 0.015 ohms) provides sufficient braking torque and reduced average heat dissipated in the armature. Wattage in the armature in one instance was reduced from an average of 2700 to 1800 watts per plug with the same voltage applied.
Another feedback used to control the net command signal, which is used to generate pulses for thyristors SCR1 and SCR2, is the current signal from the shunt CS1 located in the armature circuit of the motors. A voltage of 0 to 220 millivolts, for example, is differentially detected, filtered, amplified and supplied to the Firing Logic function FL. References are set for normal drive and plugging mode I ref which provide a point to indicate when a maximum has been exceeded. The control algorithm for the microcomputer MC is designed to limit maximum current. It is desirable to allow maximum current whenever it is called for to provide strong acceleration. Therefore, the current feedback is used to limit maximum armature current in all modes of operation.
After a command signal has been processed through the velocity control function, the resultant error signal (speed command) is sent to the Firing Logic function FL. This function uses the microcomputer MC to determine the correct firing sequence for thyristors SCR1 and SCR2. It analyzes information composed of speed command, current feedback, contactor state, plugging state and system diagnostic condition. From this the control algorithm generates the correct firing duty cycle and frequency.
Normal driving will generate a firing sequence as described below which gives maximum current and voltage sourcing to the motor. This function is also the central operations control element. When an event occurs that is outside the limits, this function will slow or stop further SCR firing. The events shown below can cause the alteration of the firing sequence.
a) If maximum current has been exceeded, the firing sequence will turn off until the current is within acceptable limits.
b) If plugging operation is detected, the frequency and duty cycle will be reduced to approximately 10% of the maximum seen during normal driving.
c) If the contactors are in a transition mode, the firing sequence will stop until that action is complete.
d) If the diagnostic monitoring function senses a system error, the firing logic stops the pulse generation and removes commands to the contactor control.
Pulse width modulation and frequency modulation are achieved by controlling two gate drive signals to the SCRs. The main SCR (SCR1) is gated on by one pulse supplied via connection 3. This allows current to flow from the battery through SCR1, the transformer T1 primary, the forward 1F, 2F or reverse 1R, 2R contactor tips, through the field windings F1, F2, the motor armatures A1, A2, the current shunt CS1 and back to the battery.
A voltage change at the primary winding of transformer T1 is coupled to the secondary winding with a phase reversal and step-up ratio of approximately 1:4. The voltage across the secondary winding provides the potential for the capacitor C1 to charge to approximately 2.5 times battery voltage. At this time, SCR2 is turned off and charging rectifier REC1, after providing a charging path for capacitor C1, will hold the charge.
To turn off SCR1, thyristor SCR2 is gated on which will draw current away from SCR1, allowing it to turn off. This happens by SCR2 conducting hard for about 100 microseconds because of the B+ potential on the anode and the large relative negative potential on the cathode side due to the capacitor C1 charge. While SCR2 is conducting hard, equalizing the charge on capacitor C1, current is drawn away from the path through SCR1 for a time sufficient for it to stop conducting and turn off.
This commutation action is repeated at various rates and frequencies to control the speed of the motor.
When a speed command signal is received from the analog circuits, the pulse generation function PG will send out pulses to the SCRs until one of several things happen:
a) the command signal is removed or reduced;
b) the maximum speed-limit has been achieved;
c) the maximum current level has been reached;
d) the "M" range contactor energizes; or
e) the diagnostic circuits indicate an operational failure.
The frequency and pulse width selection is designed to develop sufficient motor torque and maximize power amplifier efficiency. The frequency range may be 0-250 Hz and the pulse width from 1-99%, for example.
The status of contactors 1F, 2F, 1R, 2R, M and 1S is monitored continuously by the Contactor Sensing function CS via connections 9, 10, 11 and 12, to provide signals in response to the voltage across the contactor coils which shifts from about 2 volts when the coils are energized to about B+ voltage when deenergized.
Contactor position status is sent to the Firing Logic function FL for inputs to the decision algorithm described previously.
Throttle switches are used by the operator's speed controller, shown in FIG. 7, to call for a directional contactor to change state when the operator moves the handle from neutral to either direction, a first output FDCC (forward direction contactor control) is generated for forward motion and a second output RDCC (reverse direction contactor control) is generated for reverse motion. As the handle continues to move towards the maximum speed position, the same controller will call for the "M" contactor to energize when the handle has moved approximately 80% of its full stroke and an output is provided on line MCC.
The contactor control coil drivers, DR3 for "M" and DR1-DR2 for Forward/Reverse, switch two coils each directly. These drivers act as disconnect devices if the Firing Logic function FL determines that the contactor(s) should not operate. The switching means are additional drivers in series with the contactor control. They will call for the contactor(s) to be energized, but the coil drivers in the contactor control have ultimate control. This redundant contactor switching technique gives the operator an extra margin of safety should a failure occur.
The equalization contactor 1S is also controlled by the contactor control function. It is used to short the fields of the two motors together during the plugging operation and to switch the plugging resistor in and out of the armature circuit. The contactor tips that short the motor fields 1Sa are normally closed when no power is applied. The tips 1Sb that switch resistor R1 are normally open.
Resistor R5 is used to dissipate the heat developed during the plugging operation. When the armature becomes a generator, it supplies current through current shunt CS1, resistor R5, plugging rectifiers REC3 and REC4 and back to the armature. The resistor limits the peak current and absorbs some of the energy instead of all of it going into the armature. When the plugging sequence is finished, the contactor tips ISb close, which takes the resistor out of the circuit. It is not advantageous to limit recirculating current during normal drive operation. Each time SCR1 turns off, the magnetic fields created by current through the motor field windings collapse. That collapse generates a current through the armatures and back to each field through rectifier REC2. This current gives an additional torque boost to the motor output and improves acceleration. Removing the resistor R5 by contactor switching improves that operation and eliminates wasted energy across the resistor when not needed.
The output from the contactor control function to control the equalization contactor 1S is a low level digital signal. An external driver DR4 is used to switch the voltage for the contactor coil.
The firing logic determines the state or quadrant in which the system is operating and then energizes the appropriate contactor(s). There are seven operational states for the truck, as follows:
______________________________________OPERATIONAL STATE CONTACTOR USED______________________________________Neutral-No travel speed NoneForward Motion-Normal Drive 1F, 2FForward Motion-Normal Drive 1F, 2F, M"M" RangeForward Motion-Plugging 1R, 2R, 1S (Deenergized)Reverse Motion-Normal Drive 1R, 2RReverse Motion-Normal Drive 1R, 2R, M"M" RangeReverse Motion-Plugging 1F, 2F, 1S (Deenergized)______________________________________
Inputs are sent to the diagnostic monitoring function from the contactor sensing and plug detect functions as well as from the SCR chopper circuit via connection 4. It is the purpose of this function to test for proper event sequencing and operating conditions continuously. The result of this testing is sent to the Firing Logic function FL for system implementation and is shown in a single alphanumeric display DS. This display DS will show both status and fault codes which are used by truck service personnel to check operational readiness or for troubleshooting.
Because of the harsh mechanical and electrical environment, the diagnostic monitoring function must be tolerant of transients that can exist. Whenever a fault code is generated, it is tested two more times before the display shows that code and action is taken.
The action required after a fault code appears is to stop generating pulses for the SCRs and disable all contactors. For critical fault codes, resetting the system requires the B+ connection to be interrupted by turning the keyswitch KS off, then on again.
For less critical fault codes the system can be reset up to three times by returning the speed control handle to the neutral position. After that, the reset must take place by resetting the keyswitch.
From all of the foregoing it will be apparent that the invention provides a new and useful electric motor control system specifically directed to an improved arrangement for plugging a pair of series-connected direct current motors by a common current-limiting resistor, which is shunted out of the circuit except when plugging action is desired. The operation of the shunting contactor is governed by means which determines that the current through the motors is at or near zero when the contactor is operated, thus reducing wear and arcing of the shunting contacts.
Since other modifications and changes varied to fit particular operating requirements and environments will be apparent to those skilled in the art, the invention is not considered limited to the example chosen for purposes of disclosure and covers all changes and modifications which do not constitute departures from the true spirit and scope of this invention.
Having thus described the invention, what is desired to be protected by Letters Patent is presented by the subsequently appended claims. | The present invention features an electric motor control system combination with at least one electric motor having a field winding and an armature winding connected in series. The system also includes a first power terminal, a second power terminal, a current-limiting resistor, and a current sensor. The current-limiting resistor and the current sensor are connected in series between the first power terminal and the second power terminal. A contactor has a contact operable to shunt the current-limiting resistor. A microcomputerized control connected to the contactor and the current sensor governs the contractor to shunt the current-limiting resistor when the electric motor is not in a plugged condition. The contactor is operative when the current sensor detects a substantially zero current through the electric motor. The microcomputerized control continuously regulates power being supplied to the electric motor and provides optimum armature current in all operative modes of the electric motor, including a braking mode. This results in smooth braking that is accomplished with a minimum of armature heating. | 7 |
The invention relates to a process for shortening textile fibers, in particular bleached cotton wastes, consisting in:
(a) continuously moving a pad of fibers between a trough-plate and a feed roller provided with rounded roughnesses which rotates in the feed direction of the fiber pad and compresses it,
(b) pulling the fiber pad beyond the trough-plate by means of a drum provided with cutting roughnesses rotating in the same direction as the feed roller but at a higher tangential speed than said cylinder,
(c) reconstituting the sheet of fibers,
Another object of the invention are the textile fibers obtained by this process and their use in making absorbing pads for disposable articles, in particular for baby diapers.
The dry fabrication of non-woven materials from short fibers is known. However, the implemented methods do not shorten the fibers, merely they open the raw material and distribute the fiber in random or unidirectional manner depending on the desired non-woven material.
The opening or tearing of the fibers consists in moving the fiber pad between a trough-shaped support and a feed roller compressing the pad by 0.08 to 0.12 MPa and then in placing the sheet so formed against a break-up drum with spikes which rotates at a tangential speed up to 30 times that of the feed cylinder.
These known methods are described in particular in the following patents:
French Pat. No. 2,322,941 describes a method of preparation by carding wherein an initial sheet of textile flocks is moved to a trough-shaped table by the feed roller and then is placed against another rotary break-up so as to mechanically untangle, open, and clean said sheet. The fiber tufts so obtained then are pneumatically dispersed in a conduit subject to air circulation and then collected on a perforated surface.
French Pat. No. 2,411,257 describes also an apparatus for opening and cleaning cotton wastes using untangling rollers located in the untangling zone.
French Pat. No. 2,283,247 describes a tearing machine consisting of a trough-shaped plate, a perforated feed roller, a drum with spikes, and a suction duct.
Belgian Pat. No. 662,569 also describes a tearing machine in a particular for treating cotton wastes. The material is driven by a trough-shaped plate provided at its ridge with a specially serrated knife and with a cylinder which is also serrated. A hook drum is mounted parallel to the axis and at the same level.
The purposes of all these methods are merely to improve fiber separation, but do not contribute to shorten them. It must be emphasized that it is even the opposite goal which is pursued since the object is to recover intact fibers once the fiber pad has been opened or torn.
The object of the invention is to offer a process making it possible to shorten the cotton fibers so as to make them useful when manufacturing absorbing pads for paper diaper-making machines which typically are fed with paper pulp.
The parameters and components of the apparatus for implementing the process of the invention are as follows:
the pressure exerted by the feed roller on the fiber pad exceeds 0.25 MPa;
the tangential speed of the drum provided with cutting roughnesses is at least 50 times that of the tangential speed of the feed roller;
in the vertical space between the top of the trough-shaped plate and the drum provided with cutting roughnesses a means is provided making it possible to tear a part or the whole of the textile fibers with a length in excess of 10 mm.
The rounded roughnesses provided on the feed roller may consist of cross-sectionally circular transverse bars or flutings making possible simultaneously, the advance of the pad and its being kept in place, that is, these roughnesses prevent the pad subjected to the action of the cutting-roughnesses drum from slipping.
Preferably the fiber pad consists of fibers from wastes recovered in spinning mills or cotton treatment plants. As a rule cotton wastes consist of fiber lengths far too large to be transformed as such on diaper-making machines. Furthermore, the capability of re-using these cotton wastes is one of the significant advantages offered by the invention. The economies flowing from this fact are reflected in the price of the raw material from which the absorbing pads are made, and it decreases by that amount the manufacturing price of the article which in this case is disposable. The absorbing material obtained in this manner can be estimated to cost twice or three times less than that prepared from paper pulp fibers.
The means used to tear all or part of the textile fibers with a length exceeding 10 mm may be a cutting blade located at the bottom of the trough on the side of the cutting-roughnesses drum.
The following may be among the cutting-roughnesses drums: drums with spikes, drums with sawteeth, drums with needles, drums with hooks. Among the above, the sawtooth and spike drums are preferred, and especially the drums comprising at least 50,000, and preferably 70,000 to 90,000, spikes.
Preferably the gap between the end of the cutting roughnesses and the upper edge of the vertical projection is between 0.1 and 1 mm, and preferably between 0.2 and 0.6 mm.
In order to obtain a more homogeneous statistical distribution of the fiber lengths, the above-described operation preferably is restarted several times but in the absence of the means for tearing the fibers. Preferably the above-stated operation is begun over twice, and better yet, three times. In the first operation, that is the one more specifically the object of the invention, the porcupine drum offers the best results. Preferably the tangential speed of the feed roller is between 0.05 m/s and 0.3 m/s and that of the cutting-roughnesses drum is between 25 m/s and 70 m/s, and in particular between about 0.15 and 0.25 m/s for the feed roller and 35 and 45 m/s for the cutting-roughnesses drum.
Another object of the invention are textile fibers and in particular bleached cotton fibers of which at least 70% have lengths between 5 and 15 mm, where these fibers are prepared by the above-described process. Preferably at least 40% of the fibers have lengths between 5 and 10 mm, and 30% at least have lengths between 10 and 15 mm.
Another object of the invention is the use of these textile fibers in making absorbing and disposable pads, in particular baby diapers.
The textile fibers obtained in the invention are much more absorbent than the fibers prepared from cellulose pulp; and, moreover, those of the invention offer a lesser leakage rate in the diapers. The invention is illustrated by describing a detailed embodiment and then by examples.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a longitudinal section of the apparatus for implementing the process of the invention.
FIG. 2 is a longitudinal section of the apparatus implementing the preferred process of the invention. This is the process wherein the cutting operation is performed three times using three operational assemblies A, B, C.
The fiber pad 1 consists of bleached cotton wastes and is moved in continuous manner on a trough-plate 2 by means of a conveyor belt 3. A fluted or grooved feed roller 5 is located so as to hug the concave side 4 of the trough-plate 2. This roller rotates in the direction shown by the arrow and exerts a pressure between 0.3 and 0.6 MPa on the pad by means of the transmission shaft 6. The vertical edge 8 opposite the vertical edge 7 facing the conveyor belt 3 is bevelled at its top. The bevel 9 is at an angle to the vertical which amounts to 0.01π to 0.1π. The bevel 9 passes through a shoulder 10 into the convex side 4. This shoulder coincides with the line connecting the centers of the feed roller 5 and the procupine drum 11 described below. A drum 11 provided with 80,000 spikes is located next to the vertical edge 8 and rotates in the same direction as the feed roller. This drum pulls the pad beyond the shoulder and tears thereby the long fibers while opening the short ones. The fibers so processed are moved by means of pulsed air from the blower 29 through a conduit consisting of the inside drum surface and a support 12 to the exit 13 communicating with a compartment 14 where the fiber pad can be reconstituted. This compartment consists at the exit 13 of a support 15 extending the support 12 and moving the fibers to make contact with a drum 16 rotating oppositely to the preceding drum. This drum 16 itself makes contact at a point substantially opposite support 15 with an operational roller 17 rotating in the same direction as drum 16. The drum 17 itself is adjacent to a drum 18 rotating in the inverse direction so as to compact the sheet when passing between the two rollers and then to evacuate it.
The dimensions of the components of the above-described apparatus are the following:
______________________________________ in mm______________________________________diameter of feed roller 5 180diameter of porcupine drum 11 1000diameter of drum 16 780diameter of compacting roller 17 130diameter of compacting roller 18 180dimension of bevel 9 h = 6 mm; w = 1 mm______________________________________
FIG. 2 shows the apparatus for implementing the preferred process of the invention, that is in the three successive operations. Once the torn fiber sheet has been compacted between the rollers 17 and 18, it is re-introduced in a compartment 19 including a trough-plate 20 with a rounded upper edge, that is a wholly conventional trough-plate, and a sawtooth drum 21 with the teeth directed in the sense of the rotation, whereupon said sheet is moved to a compartment 22 identical with the compartment 14 and for forming the sheet. Where the third operation is called for, the sheet passes into a compartment 23 identical with the compartment 19 and including a trough-plate 24 and a sawtooth drum 25, and then again moves into a sheet-constituting compartment 26 identical with the compartments 14 and 22, and lastly it is moved toward the exit 27. Now being constituted, the sheet is directly fed to the diaper-making machine 28 (not shown).
Regarding the two-operation process, the procedure is as follows:
during the second operation, the drum is a sawtooth drum,
the pressures exerted by the feed rollers are between 0.3 and 0.6 MPa,
the tangential rotational speed of the various rollers and drums is between the values below:
______________________________________ in m/s______________________________________1st operation feed roller 0.15 to 0.25 cutting-roughnesses drum 35 to 452nd operation feed roller 0.11 to 0.2 cutting-roughnesses drum 40 to 60______________________________________
the gaps between the cutting-roughnesses drum on one hand and the lines extending the vertical part of the edge 8 opposite the cutting-roughnesses drum on the other are between 0.3 and 0.6 mm in the first operation and between 0.2 and 0.5 mm for the second operation.
Regarding the three-operation process, preferably the procedures are as follows:
in the second operation the cutting-roughnesses drum preferably is a sawtooth drum,
the pressure applied by the various feed rollers is between 0.3 and 0.6 MPa,
the tangential speed of rotation of the various rollers and drums is as follows:
______________________________________ in m/s______________________________________1st operation feed roller 0.15 to 0.25 cutting-roughnesses drum 35 to 452nd operation feed roller 0.11 to 0.2 cutting-roughnesses drum 40 to 603rd operation feed roller 0.11 to 0.2 cutting-roughnesses drum 40 to 60______________________________________
the gaps between the cutting-roughnesses drum on one hand and the line extending the vertical part of the edge opposite the cutting-roughnesses drum on the other are between 0.3 and 0.6 mm in the first operation and between 0.2 and 0.5 mm for the second and third operations.
The examples below illustrate the invention.
EXAMPLE 1
Two Successive Operations
First Operation
The feed roller applies a pressure of 0.50 MPa and rotates at 0.2 m/s. The specific weight of the bleached cotton pad is 800 g/m 2 . The drum comprises 80,000 spikes and rotates at 40 m/s. The gap between the edge vertical wall and the drum tangent is 0.4 mm.
Second Operation
(No bevel, with conventional trough-plate)
The feed roller features are the same as in the first operation except that its rotational speed is 0.16 m/s. In this instance the drum is one with sawteeth, it rotates at 55 m/s. The gap between the edge vertical wall and the drum tangent again is 0.4 mm.
Following these two operations, the fibers are collected; their statistical distribution with respect to length is as follows:
______________________________________Fiber Length (in mm) %______________________________________ 5-10 5010-15 3515-20 820-25 525-30 2______________________________________
EXAMPLE 2
Three Successive Operations
The first two operations are identical with those described in Example 1. After the second operation, the fiber pad is subjected to the following third operation:
the roller characteristics are the same as for the second operation, namely the pressure is 0.50 MPa and the speed is 0.16 m/s,
the drum has sawteeth and rotates at 55 m/s. The gap between the drum tangent and the vertical wall of the edge is reduced to 0.3 mm.
Following these three operations, the fibers are collected; their statistical distribution with respect to length is as follows:
______________________________________Fiber Length (in mm) %______________________________________ 5-10 5010-15 4015-20 10______________________________________
EXAMPLE 3
Three Successive Operations
The three operations were carried out with 80,000 spike drums under the same conditions as for Example 2 as regards the gaps, the speeds, and pressures. Fibers are collected of which the statistical distribution with respect to length is as follows:
______________________________________Fiber Length (in mm) %______________________________________ 5-10 5010-15 3515-20 620-25 525-30 3______________________________________
EXAMPLE 4
Absorptivity
The absorptivity of the fiber pad of Example 2 was rated as follows:
Diapers weighing 58 g and including 49 g of fibers were worn by a score of babies. These diapers absorb about 4.8 g of body fluids per gram of fibers, whereas under the same conditions diapers including cellulose foam (fluff) absorb only 4 grams per gram of fibers. The gain in absorptivity, therefore, is 20%. Moreover, it was observed long-term that the "cotton" diapers leak less than the "fluff" diapers. | The invention relates to bleached cotton fibers and to absorbing materials for disposable articles. Its object is a process for shortening bleached cotton fibers consisting in
(a) moving a fiber pad (1) between a trough-plate (2) and a feed roller (5) exerting a pressure between 0.3 and 0.6 MPa on the fiber pad,
(b) pulling the fiber pad (1) beyond the trough-plate (2) bevelled at (9) so as to cut the long fibers constituting the fiber pad,
(c) reconstituting the sheet.
This process makes it possible to obtain fibers which can be used directly in diaper-making machines. The disposable articles so produced offer remarkable absorbing properties. | 3 |
BACKGROUND
Drilling offshore oil and gas wells includes the use of offshore platforms for the exploitation of undersea petroleum and natural gas deposits. In deep water applications, floating platforms (such as spars, tension leg platforms, extended draft platforms, dynamically positioned platforms, and semi-submersible platforms) are typically used. One type of offshore platform, a tension leg platform (“TLP”), is a vertically moored floating structure used for offshore oil and gas production. The TLP is permanently moored by groups of tethers, called tension legs, that eliminate virtually all vertical motion of the TLP. Another type of platform is a spar, which typically consists of a large-diameter, single vertical cylinder extending into the water and supporting a deck. Spars are moored to the seabed like TLPs, but whereas a TLP has vertical tension tethers, a spar has more conventional mooring lines.
Offshore platforms typically support risers that extend from one or more wellheads or structures on the seabed to the platform on the sea surface. The risers connect the subsea well with the platform to protect the fluid integrity of the well and to provide a fluid conduit between the platform and the wellbore.
Risers that connect the surface wellhead on the platform to the subsea wellhead can be thousands of feet long and extremely heavy. To prevent the risers from potentially buckling under their own weight or placing too much stress on the subsea wellhead, upward tension is applied, or the riser is lifted, to support a portion of the weight of the riser. Since offshore platforms often move due to wind, waves, and currents, for example, the risers are tensioned such that the platform can move relative to the risers. To that end, the tensioning mechanism often exerts a substantially continuous tension force on the riser.
Risers can be tensioned by using buoyancy devices that independently support the riser, which allows the platform to move up and down relative to the riser. This isolates the riser from the heave motion of the platform and eliminates any increased riser tension caused by the horizontal offset of the platform in response to the marine environment. This type of riser is referred to as a freestanding riser.
Hydro-pneumatic tensioner systems are another type of a riser tensioning mechanism. In this type of system, a plurality of active hydraulic cylinders with pneumatic accumulators is connected between the platform and the riser to provide and maintain the desired riser tension. The platform's displacement, which may be due to environmental conditions, that causes changes in riser length relative to the platform are compensated by the tensioning cylinders adjusting for the movement.
Floating platforms, which are used for deeper drilling and production, often encounter additional challenges, such as thermal expansion, due to the fact that the drilling extends into very high temperature formations where special drilling equipment may be required. At high temperatures, the riser, which extends from the sea floor, is subject to expansion and contraction. And that expansion and contraction of the production/drilling riser may result in undesirable movement, such as buckling, in response to temperature changes.
BRIEF DESCRIPTION OF THE DRAWINGS
A better understanding of the various disclosed system and method embodiments can be obtained when the following detailed description is considered in conjunction with the drawings, in which:
FIG. 1 is an illustrative, production riser system for elevated temperatures with completion landed;
FIG. 2 is an embodiment of an annular tensioner with castellated gathering fingers;
FIG. 3 is an illustrative, production riser system with production in operation at elevated temperatures;
FIG. 4 is an illustrative, production riser system with control lines running outside the annular tensioner space;
FIG. 5 is an illustrative offshore drilling system in accordance with various embodiments;
FIG. 6 is an illustrative drilling riser system including an outer riser with a nested internal riser; and
FIG. 7 is the drilling riser system of FIG. 6 with the inner riser installed within the outer riser.
DETAILED DESCRIPTION
The following discussion is directed to various embodiments of the invention. The drawing figures are not necessarily to scale. Certain features of the described embodiments may be shown exaggerated in scale or in somewhat schematic form, and some details of conventional elements may not be shown in the interest of clarity and conciseness. Although one or more of these embodiments may be preferred, the embodiments disclosed should not be interpreted, or otherwise used, as limiting the scope of the disclosure, including the claims. It is to be fully recognized that the different teachings of the embodiments discussed below may be employed separately or in any suitable combination to produce desired results. In addition, one skilled in the art will understand that the following description has broad application, and the discussion of any embodiment is meant only to be exemplary of that embodiment, and not intended to intimate that the scope of the disclosure, including the claims, is limited to that embodiment.
Certain terms are used throughout the following description, and claims to refer to particular features or components. As one skilled in the art will appreciate, different persons may refer to the same feature or component by different names. This document does not intend to distinguish between components or features that differ in name but not function.
In the following discussion and in the claims, the terms “including” and “comprising” are used in an open-ended fashion, and thus should be interpreted to mean “including, but not limited to . . . . ” Also, the term “couple” or “couples” is intended to mean either an indirect or direct connection. Thus, if a first device couples to a second device, that connection may be through a direct connection, or through an indirect connection via other devices, components, and connections. In addition, as used herein, the terms “axial” and “axially” generally mean along or parallel to a central axis (e.g., central axis of a body or a port), while the terms “radial” and “radially” generally mean perpendicular to the central axis. For instance, an axial distance refers to a distance measured along or parallel to the central axis, and a radial distance means a distance measured perpendicular to the central axis.
Disclosed herein is a system for conveying fluid from a subsea well to a floating platform. The system includes a subsea wellhead, and an outer tubing connected at a lower end and supported in tension at the upper portion by the floating platform. Inner tubing is also included. The inner tubing is connected at a lower end to the subsea wellhead and is dynamically supported in tension at an upper end by the outer tubing so that the inner tubing can move relative to the outer tubing.
An embodiment of the system can facilitate production of fluid from a subsea well to a floating platform. The system includes a subsea wellhead, a production riser connected at a lower end to the subsea wellhead and supported in tension at an upper portion by the floating platform. A production tubing, a production tree, and a tubing hanger are also included in this embodiment. The production tubing is connected at a lower end to the subsea wellhead and dynamically supported in tension at an upper end by the production riser so as to be capable of movement relative to the production riser. The production tree is fixed to the upper portion of the production riser. The tubing hanger is landed in and supported by the production tree with the production tubing being in fluid communication with the tubing hanger while being dynamically supported for movement relative to the tubing hanger.
FIG. 1 illustrates an embodiment of such a production riser for elevated production fluid temperatures. The production riser system includes a production riser 120 connected with a subsea wellhead (not shown). A production tubing 108 extends within the production riser 120 and is in fluid communication with the production fluids from the well. A dynamic tensioner 112 maintains the production riser 120 in tension as the floating platform 317 moves. The production riser system also includes a production tree 104 installed on the upper end of the production riser 120 . The production tree 104 control the flow of fluids into and out of the well, and can be a vertical or horizontal “spool” tree. As shown, the production tree 104 is a horizontal tree.
The production tree 104 supports a tubing hanger 102 that is in fluid communication with the production tubing 108 . And that production tubing 108 is dynamically supported for movement relative to the tubing hanger 102 , as explained below. The production tubing 108 further includes a slip connector 124 at a position along the length of the inner tubing. Although the slip connector 124 is shown near the upper portion of the riser system, the connector can be located in the center of the riser or even at the lower subsea portion of the production riser system.
The slip connector 124 includes an overshot tubing 125 that includes an open lower end and internal volume. A polished bore rod (PBR) 110 in fluid communication with the well below the overshot tubing extends into the internal volume of the overshot tubing through the overshot tubing's open lower end and is movable within the overshot tubing. The overshot tubing also includes a centralizer 127 for centering the overshot tubing within the production riser 120 . The overshot tubing also includes a dynamic seal 129 for sealing against the outside of the PBR as explained further below. The centralizer centralizes the overshot tubing within the production riser 120 for easier insertion of the PBR into the overshot tubing without damaging the overshot tubing's dynamic seal against the PBR.
The system for conveying fluids further includes an outer tubing with an internal shoulder, an inner tubing with an external shoulder, and an annular tensioner landed on both the outer tubing internal shoulder and the inner tubing external shoulder. The annular tensioner is movable to dynamically support the production tubing in tension. As shown in the embodiment of a production riser system, the annular tensioner 112 includes a tension plug 114 surrounding the production tubing with an outer diameter larger than the inner diameter of the production riser internal shoulder. The annular tensioner 112 also includes a tension piston 116 surrounding the production tubing with an inner diameter less than the outer diameter of the production tubing external shoulder. The tension plug 114 and tension piston 116 are located in the production riser and seal against the inside of the production riser and the outside of the production tubing to form a sealed chamber. The tension piston 116 is movable within the production riser with respect to the tension plug 114 from pressure in the sealed chamber as the production tubing moves relative to the production riser. Both the tension piston 116 and the tension plug 114 include castellated gathering fingers 235 a and 235 b for coupling to each other, as illustrated in FIG. 2 . The castellated gathering fingers on both the tension plug 114 and the tension piston 116 include an angled ramp area. These angled ramps gather the control lines inside the sealed chamber to avoid pinching as the tensioner plug 114 and the tensioner piston 116 come together.
As shown in FIG. 1 , the tension piston 116 , when initially installed, may rest on the tension plug 114 , and be designed to place the production tubing in tension. One option thus includes landing in tension. However, another option includes applying pressure to the annular tensioner 112 sealed chamber and holding that tubing 108 in tension.
The production riser itself could be several hundred to several thousand feet. The tension piston rests on the tension plug, which rests on tension joint that is supported by the dynamic tensioner on the platform. The top of the tension joint is pulled up, and the bottom of the tension joint is pushed down; and the tension joint body goes into tension, but sums to zero. The external tensioner setting is established to keep the external riser pipe 120 in tension. This is accomplished with sufficient tensioner setting to keep the production riser 120 in tension.
For installation, the production riser is attached to the subsea wellhead and set up in tension using the dynamic tensioner. The production tubing is then run in and attached to the subsea wellhead. When enough of the production tubing is installed, the annular tensioner components are installed and the production tubing is placed in tension. Completion related control lines 126 are run through the tension piston 116 , coil around the production tubing inside the sealed chamber and then exit the tension plug 114 . Penetrations are sealed with fittings, lines are continuous, and the coils allow the necessary movement up and down of the tension piston. The various control lines 126 are used to operate various valves in the permanently installed subsea piping.
Finally, the PBR is attached to the production tubing and the tubing hanger 102 and overshot assembly is lowered into the production tree allowing the overshot to swallow the PBR 110 . The blowout preventer is then removed, all control lines 126 are finalized, and tree 104 is capped.
FIG. 3 illustrates a production riser system operating with production fluid at elevated temperatures. Here, the tubing 308 has expanded in length due to heating. The overshot connector 324 helps to accommodate the expanded tubing 308 while maintaining the dynamic seal with the PBR. The annular tensioner sealed chamber pressure supply is at a level sufficient to move the tension piston upwards with the production tubing outer shoulder and thus hold the production tubing in tension despite the upward movement. Alternatively, a pressure supply may maintain the pressure in the sealed chamber so as to place enough force on the tension piston to keep the production tubing in tension. The necessary pressure in the sealed chamber may be determined based on measurements of a characteristic of the sealed chamber, such as pressure, temperature, or position of the production tubing.
There are multiple advantages to the presented invention. One main advantage is that the floating structure buoyancy needs are reduced, along with the tensioner system capacity. Normally, a subsea, wellhead tubing hanger carries significant tubing loads. Further, this system allows the external riser to stay in tension with standard external tensioner approach. This system may also be used to support a drilling riser with an inner pipe requirement. Overall, it is important to note that this exemplary system supports the inner pipe in tension, avoids compression, and avoids buckling by use of an the annular tensioner. Finally, all seals and annuli may be monitored from the floating structure deck.
As discussed above, there are various options for configuration and the use of multiple components. Another advantage of the present invention is the ability to employ several methods for not requiring the down hole lines to penetrate the annular tensioner space. The control lines would simply exit the tension joint, radially by several methods. FIG. 4 shows a method which could have a taller tension plug 414 with several radial line exits for hydraulic service. This solution does not address the optical line. This option does not require the use of orientation of the tension plug to the tension joint because each subsequent line is ported stacking up the plug. In other words, once the tension plug is in place, the tension plug porting and the tension joint porting would line up without orientation. A control, monitoring, and injection lines manifold 432 would be positioned upon the TLP deck 434 . An advantage of this embodiment would be the elimination of penetration through the annular tensioner space in the riser system, which normally would require numerous control, monitoring, or injection lines.
Another alternative would allow direct connection of the control lines, but also require orientation of the plug with respect to the tension joint. A port can be coupled directly to a control line. By “direct,” it is intended to include a connection or coupling between a control line and a port that does not requires annular seals that are used to seal annular zones. A control, monitoring, and injection lines manifold 432 would be positioned upon the TLP deck 434 . The advantage of this embodiment would be the elimination of penetration through the annular tensioner space in the riser system, which normally would require numerous control, monitoring, or injection lines. This could be a solution on dual barrier drilling riser or on elevated temperature production risers. As an added feature, the system will include control and other down-hole hydraulic and/or fiber-optic lines without sharing space with an annular tensioner feature.
Another embodiment is also included in the present invention. This embodiment is a drilling riser system connected to a wellhead located at a seafloor. The drilling riser system includes an external riser for a floating structure with an external tensioner keeping the external riser pipe in tension. The drilling riser system also includes an internal riser with an overshot slip connector and annular tensioner as described above. The drilling riser system is such that the outer and inner drilling risers allow passage of a drill bit and drill string through the riser to the subsea well.
Referring now to FIG. 5 , a schematic view of an offshore drilling system 500 is shown. The drilling system 500 may be of any suitable configuration. For example, the drilling system 500 may be a dry BOP system and include a floating platform 501 equipped with a drilling module 502 that supports a hoist 503 . Drilling of oil and gas wells is carried out by a string of drill pipes connected together by tool joints 504 so as to form a drill string 505 extending subsea from platform 501 . The hoist 503 suspends a kelly 506 used to lower the drill string 505 . Connected to the lower end of the drill string 505 is a drill bit 507 . The bit 507 is rotated by rotating the drill string 505 and/or a downhole motor (e.g., downhole mud motor). Drilling fluid, also referred to as drilling mud, is pumped by mud recirculation equipment 508 (e.g., mud pumps, shakers, etc.) disposed on the platform 501 . The drilling mud is pumped at a relatively high pressure and volume through the drilling kelly 506 and down the drill string 505 to the drill bit 507 . The drilling mud exits the drill bit 507 through nozzles or jets in face of the drill bit 507 . The mud then returns to the platform 501 at the sea surface 511 via an annulus 512 between the drill string 505 and the borehole 513 , through subsea wellhead 509 at the sea floor 514 , and up an annulus 515 between the drill string 505 and a riser system 516 extending through the sea 517 from the subsea wellhead 509 to the platform 501 . At the sea surface 511 , the drilling mud is cleaned and then recirculated by the recirculation equipment 508 . The drilling mud is used to cool the drill bit 507 , to carry cuttings from the base of the borehole to the platform 501 , and to balance the hydrostatic pressure in the rock formations. Pressure control equipment such as blow-out preventer (“BOP”) 510 is located on the floating platform 501 and connected to the riser system 516 , making the system a dry BOP system because there is no subsea BOP located at the subsea wellhead 509 . With the pressure control equipment at the platform 501 , the dual barrier requirement may be met by the riser system 516 including an external riser with a nested internal riser.
As shown in FIG. 6 , the external riser 600 surrounds at least a portion of the internal riser 602 . The riser system is shown broken up to be able to include detail on specific sections but it should be appreciated that the riser system maintains fluid integrity from the subsea wellhead to the platform.
A nested riser system requires both the external riser 600 and the internal riser 602 to be held in tension to prevent buckling. Complications may occur in high temperature, deep water environments because different thermal expansion is realized by the external riser 600 and the internal riser 602 due to different temperature exposures—higher temperature drilling fluid versus seawater. To accommodate different tensioning requirements, independent tension devices are provided to tension the external riser 600 and the internal riser 602 at least somewhat or completely independently.
In this embodiment, the external riser 600 is attached at its lower end to the subsea wellhead 509 (shown in FIG. 5 ) using an appropriate connection. For example, the external riser 600 may include a wellhead connector 604 with an integral stress joint as shown. As an example, the wellhead connector 604 may be an external tie back connector. Alternatively, the stress joint may be separate from the wellhead connector 604 . The external riser 600 may or may not include other specific riser joints, such as riser joints with strakes or fairings and splash zone joints 608 . This embodiment also includes a surface BOP 660 . Other appropriate equipment for installation or removal of the external riser 600 and the internal riser 602 , such as a riser running tool 650 and spider 652 may also be located on the platform.
As shown in FIG. 7 , the drilling riser system includes the external drilling riser 700 supported by the dynamic tensioner on the platform. Extending within the external riser 700 is an internal drilling riser 702 . Also included are the external shoulder on the internal drilling riser, the internal shoulder on the external drilling riser 700 , and the annular tensioner. The annular tensioner 712 operates in a similar manner to the annular tensioner described above and the discussion of its operation will not be repeated.
Instead of a production tree as shown in the production system, the external riser and the internal drilling riser of the drilling riser system terminate in a surface drilling wellhead 709 which is connected to a blowout preventer 710 on the drilling platform. Appropriate connections for circulating drilling fluid, such as a diverter (not shown) that accepts the drill string for insertion through the internal drilling riser, are attached to the top of the BOP 710 .
Also included as part of the internal drilling riser is the overshot slip connector 711 using the overshot tubing and PBR 713 . As discussed above, the overshot slip connector allows for the movement of the internal drilling riser relative to the external riser due to thermal expansion. The annular tensioner maintains the internal riser in tension during such movement so as to avoid buckling.
Other embodiments of the present invention can include alternative variations. These and other variations and modifications will become apparent to those skilled in the art once the above disclosure is fully appreciated. It is intended that the following claims be interpreted to embrace all such variations and modifications. | The riser system of the present invention includes an external production riser for floating structures with interfaces to the dry and subsea wellheads, internal tieback riser with a special lower overshot/slipping connector for elevated temperatures. The seals can be metallic and/or non-metallic dynamic seals. Special centralizing pipe connectors and a special subsea wellhead tubing hanger are also included. This riser system avoids the penalty of pipe within pipe differential thermal growth and the resulting unwanted effects on the floating structure. This is accomplished by allowing an overshot sealing slipping connector to swallow an expanding polished rod as thermal conditions cause pipe elongation axially. When elevated temperatures fall to ambient the opposite occurs as the pipe shrinks axially. Alternatively, a system is possible where a two pipe drilling riser is needed. The internal pipe in this case would be an inner riser rather than a tubing string. | 4 |
FIELD OF THE INVENTION
This invention relates to a motorised mobile device to be controlled by a computer.
The invention is particularly intended to be employed in an educational device arranged to receive command signals from a separate, user-progammable microcomputer. Such a device would serve to give practical experience of programs to control slave machines.
BACKGROUND OF THE INVENTION
There have been various mobile, computer-controlled devices constructed or prepared. Many have been one-off devices, built as hobby projects, research projects and the like.
SUMMARY OF THE INVENTION
The invention seeks to provide a device which can be made in quantity, commercially, and yet will facilitate, and perhaps even encourage, experimentation by the user.
This invention provides a mobile device with a chassis supported on a pair of driving wheels, and stepper motors to provide drive, with the chassis being constructed from, or at any rate compatible with, construction kit parts.
Stepper motors facilitate user programming of the computer, because a simple output pulse from the computer, or group of pulses on a few lines, can operate motor(s) to accomplish an advance, or turn by a known amount. Preferably simplicity is enhanced by arranging that one pulse, or set of pulses turns the device through an integer fraction of a circle, i.e. 360°/n where n is an integer.
Preferably n is 360, so that a signal or set of signals will turn the device by 1°. However n could be some other value, notably 180 or 720 so that the device turns by 2° or 1/2° steps. It is desirable that n is divisible by 4, to make right angle turns possible.
This use of stepper motors presents the computer user with a simple arrangement, which in preferred forms gives a simple relationship between digital signals and degrees of turn. Consequently the user should not have difficulty in achieving basic movements of the device, and will be free to concentrate on programming to effect sequences of movements.
In a preferred arrangement a digital signal or set of signals from the computer causes rotation through one increment, but a conceivable alternative is that a signal from the computer starts rotation, whereafter the computer counts digital signals returned by the circuitry as the motor(s) increment, and gives a second signal to stop rotation after the appropriate number of signals indicating increments have been returned.
Either way, it is desirable that increments of the motor(s) should be associated with a digital signal or set of digital signals which is repeated for subsequent increments--preferably being repeated for each increment.
With the preferred, two motor arrangement, one possibility is that a single digital signal should cause a single motor to turn through a single increment. A second signal can determine direction of motor revolution. Other signal arrangements are conceivable however. For example, one signal could command both motors to turn through one increment, with separate signals defining direction of turn. Another possibility is that signals for each motor could merely define the number of increments of turn required and the direction, with a further signal initiating the defined action.
Preferably the driving wheels are on a common axis, so that the motors can turn the device about the centre of that axis. A pen may be fitted at that point in order that the device can act as a so-called "logo" able to draw while manoeuvering on a sheet of paper, with the pen able to stay at a fixed point during turns.
The use of stepping motors to effect linear drive is also advantageous, because it readily enables the user to command the device to move through a fixed distance.
Signals causing the circuitry to increment a stepper motor may be voltage pulses, and the circuitry may conveniently respond to the leading edge of a pulse.
Compatibility with construction kit parts is another feature which encourages user experimentation by making it possible to modify or add further parts onto the chassis structure without permanently damaging or destroying it.
Construction kits are characterised by an ability to assemble their parts releasably, permitting dismantling and re-use of the components. They are also characterised by an ability to assemble components together in a plurality of different positions. This is generally made possible by attachment formations of some kind which are either arranged at a regular spacing in lines or arrays, or else are arranged to extend continuously, permitting attachment at any point along the length.
For example the construction kit system sold under the Trade Mark "Lego" uses projecting studs in uniformly spaced lines and two dimensional arrays. Further parts press fit over these studs.
Another construction kit system is sold under the Trade Mark "Meccano". It has uniformly spaced bolt holes in lines and arrays. The manufacturer is Miro-Meccano, 118-130 Avenue Jean-Jaures, 75942 Paris Cedex 19, France.
The preferrred construction kit is the system sold under the Trade Mark "Fischertechnik" whose parts engage together by means of continuous undercut grooves into which other parts can engage. Basic parts for this system are described in U.K. Pat. Nos. 1 094 418 and 1 094 419 the disclosures of which are incorporated herein by reference.
A further feature encouraging experimentation is to arrange that various sensing devices (e.g. contact switches, tilt switches, bar code readers) connect through separate and preferably individual, electrical connectors, so that some can be disconnected, and replaced by others.
According to a further aspect of this invention a mobile device has stepper motors for propulsion and turning with a geometrical arrangement such that when the said stepper motor(s) rotate through one angular increment, the motor(s) turn the device through a predetermined angle of 360°/n where n is an integer, the operating circuitry permitting the computer to effect and control rotation of the stepper motor(s) through any arbitrary number of increments as may be required.
The mobile device may carry a circuit board with the various electrical connectors mounted on it.
In another aspect of the invention, a second board is used to provide a static interface unit connectible to the computer and to the circuit board on the mobile device. Such a unit can be provided with cables for simultaneous connection to a plurality of ports on a computer, and a cable for connection to the mobile device.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatic representation of parts from the Fischertechnik system;
FIG. 2 is a front elevation of the mobile device, with one bumper cut away;
FIG. 3 is a rear elevation of the device;
FIG. 4 is a side elevation of the device;
FIG. 5 is a repeat of the side elevation, with parts omitted to reveal the motor and axle mountings;
FIG. 6 is a horizontal section, on the line VI--VI of FIG. 4; indicating the position of various parts;
FIG. 7 is a diagrammatic section on line VII--VII of FIGS. 2 and 3 diagrammatically illustrating the pen holder location with the front bumper omitted;
FIG. 8 is a plan view of the circuit board on top of the device;
FIG. 9 is a diagrammatic illustration of the interface board circuitry and the cables to and from it;
FIG. 10 is a circuit diagram of the circuitry carried on the mobile device.
DESCRIPTION OF PREFERRED EMBODIMENTS
The mobile device has a chassis structure built up from construction kit parts. These parts belong to the system sold under the Trade Mark "Fischertechnik" and the basic block used in that system is the subject of U.K. Pat. No. 1 094 418.
FIG. 1 illustrates basic parts from the system. It employs blocks and bars of various lengths having a standard square section 1, with an elongate undercut groove 2 running along each face. At one or both ends such blocks terminate in a projection 3, centrally positioned on the end face, and having a dovetail shape which can be slid into a groove 2, to form an end-to-side connection. Blocks can be joined side to side with links 4 of FIG. 8 cross section slid into the confronting grooves.
Blocks may have a groove across one end face as shown at 5.
Various other parts are available, and connect by means of such projections and undercuts. One example is the short brick 6, having a dovetail undercut groove 2', across one flat face and a projection 3 on the other. Another example is a plate 7, with a row of projections 3 on one face.
These parts all form a commercially available system and therefore will not be described in further detail. The manufacturer is Fischer-werke Artur Fischer GmbH & Co KG D 7244 Tumlingen/Waldachtal, Germany.
STRUCTURAL ARRANGEMENT
The chassis structure is shown in FIGS. 2 to 7. It is an approximately cubical frame built up from bars 10-14 having the cross section 1 and releasably joined together by engagement of end projections (like 3 above) into undercut grooves 2, in the manner described above. A number of shorter blocks are attached to these bars by means of links (as 4 above) and/or the projection into groove form of connection.
The chassis structure is supported on a pair of driving wheels 15 and a rear castor, in tricycle arrangement. The driving wheels 15 are mounted on respective half shafts 16 held in undercut grooves 17 across the ends of blocks 18 (FIG. 5) on the lower horizontal bars 11. Axially inwardly of each wheel is a sprocket fixed to the wheel 15 and meshing with chain 19 to drive it. Each wheel 15 a pulley fitted with rubber O-ring 20. By virtue of the convexity of the O-ring, the area of each O-ring which will contact a hard floor is quite small.
The rear caster is a large ball bearing 21 captive in a socket 22, held in place by bolts 23 passing through slots in the confronting end faces of a pair of blocks 24 (FIG. 6) which extend in horizontally from each side of the chassis and are connected to a plate 25 which extends across the rear of the chassis.
The mobile device is propelled by a pair of stepper motors 26 one at each side. These have integral mounting plates 27 which project beyond the motor casing and are bolted to grooves 28 in blocks 29, 30 which are connected into the upper and lower horizontal bars 12, 11 at each side, and are also connected directly or indirectly to the adjacent upright bars 10.
Each motor shaft carries a sprocket 31 meshing with the chain 19, to drive the associated wheel 15.
The lower bar 13 which extends across the front of the chassis supports, at its middle, an upright block 32 on the top of which is mounted a block 33 with a light dependent resistor 91 on its forward face. This block 33 is a standard Fischertechnik part. An arm 34, made up from several blocks and incorporating a central hinge 35 is connected onto the front face of the block 32. The outer part of arm 34 has a bar code reader 37 bolted to it.
The horizontal bar 13 and the front corner uprights carry hinges 38 on which are mounted plates 39 which form bumpers, one at each side of the front. These normally have the inclined position shown, but on striking an obstacle they pivot about a horizontal axis at the top of their hinges, so that small blocks 40 behind the plates 39 operate microswitches 85 carried on the underside of the bar 13. The hinges 38 have projections by which they are mounted onto the undercut groove 2 on the front of bar 13, and themselves have undercut grooves 41 to be engaged by projections on the rear of the plates 39.
The structure so far described is built up almost entirely from construction kit parts, which could if desired be dismantled and put together in other ways. Undercut grooves 2 are exposed on numerous faces of the chassis, and so additional parts could be added on to the chassis structure. All this facilitates experimentation by the user. On top of the chassis is a printed circuit board 43 on which are mounted various electrical and electronic components, to be described below. The board has corners which are shaped to fit round the tops of upright bars 10. It is held in place by small blocks 44 connected to the tops of the upright bars 10, but offset to overlie the corners of the printed circuit board 43.
As shown by FIG. 7, an upright 110 has a beam 112 pivoted on it. The beam supports the pen 81 at one end. It is arranged that the pen will drop under the force of gravity to write. A solenoid 80 is supported on the upright 110 and when energised the solenoid will pull the pen up, so that it no longer contacts the surface below. A balancing weight 114, serving to counterbalance the weight of ink in the pen reservoir, may be altered or removed as necessary.
When it is not desired to draw as the device moves the pen 81 is raised and held by a fastening (not shown) in the raised position. When it is desired to draw with the device the pen is unfastened, the device placed on a sheet of paper, and the solenoid 80 is energised and de-energised as will be described below to raise and lower the pen 81 as required.
When lowered the pen 81 will write as the mobile device moves, and for this function the device would of course be made to run over a sheet of paper.
As an alternative to the tilting beam 112, the pen 81 could be mounted on a vertical slide and moved up and down on it by a solenoid. This would be connected electrically exactly as is the illustrated solenoid 80.
DRIVE AND WHEEL GEOMETRY
The driving wheels 15, and the rear caster 21 give a tricycle arrangement so that if the motors are driven to turn both wheels 15 together the whole mobile structure will be propelled linearly forwards or backwards but if one wheel is driven forward while the other wheel is driven backward by a corresponding amount the device will turn about the central point 47 between the wheels 15.
A stepper motor is a conventional component. Here each stepper motor 26 is arranged (as further explained below) so that its armature and hence its drive shaft is rotated in discrete incremental steps of 75°. The sprocket and chain drive effects a 3:1 reduction ratio, and so one increment of a stepping motor turns the associated driving wheel 15 through 2.5° (these angles are indicated in FIG. 4, but somewhat exaggerated for clarity).
Each driving wheel 15 has a diameter d so that if both wheels turn forward the device as a whole advances by ##EQU1## for each 2.5° increment of the wheels.
If one wheel rotates through one increment forward, while the other turns one increment backwards, the device will turn around a vertical axis through the point 47. The spacing s between the wheel centre lines is chosen so that when this occurs, the single increment of each wheel turns the device through 1° around the vertical axis. The calculation of the spacing s is as follows ##EQU2## so s=2.5d
ELECTRICAL/ELECTRONIC
The mobile device described here is intended to be used with a microcomputer made by Acorn Computers and sold (at least in the United Kingdom) as the BBC microcomputer. It is available from Acorn Computers Corporation 400, Unicorn Park Drive, Woburn, Mass. 01801. This microcomputer has a digital input/output (I/O) port, a separate analogue input part, and a power supply port, intended to power a disc drive. (The mobile device could however be used with other makes and models of microcomputer providing such inputs and outputs, with appropriate modifications to the connecting circuitry, and in particular the device could be arranged to be operated by an Apple II microcomputer.
As diagrammatically represented by FIG. 9, the mobile device is connected to the microcomputer through an interface board, which is a printed circuit board 48, carrying connectors 50, 51, 52 and 53. Flexible cables 54, 55 and 56 connect between the computer 49 and the connectors 50, 51 and 52 respectively, and a cable 57 connects between the connector 53 of the interface board and a connector 58 (FIG. 8) on printed circuit board 43 carried on the mobile device.
The cable 54 terminates in a connector 60 to go into the power supply port on the computer and carries 12 V and 0 V lines. The cable 55 terminates in connector 61 to go into the analogue port. It carries four signal channels designated CH0 to CH3 respectively, a 5 V line, the analogue reference voltage and a signal return line. The cable 56 terminates in connector 62 which goes into the digital I/O port, and carries eight signal channels designated PBI to PB7, two further signal channels CB1 and CB2, return lines, and two 5 V lines.
The cables 54, 55, 56 may conveniently be 3 feet, or 1 meter or so long, but could be shorter. The cable 57 is longer, say 16 feet or 5 meters, and provides a flexible, signal-conveying link to the mobile device. It will be appreciated that the interface board is functioning to collate the lines of the various ports into a single ribbon cable with fewer cores than in the cables 54, 55, 56 combined.
If necessary the computer's analogue inputs
CH0-CH3 may be protected against overload by 100KΩ resistors and 0.1 μF capacitors between each of these lines and the return line. The Zener diode Z and associated capaciter C and resistor R may be provided to stabilise the analogue reference voltage, as a substitute for the computer's less effective stabilisation (which must then be removed).
On the interface board there is an integrated circuit providing inverting buffers 64 through which the lines PB0 to PB7 are connected to light emitting diodes 65. These illuminate to indicate the status (by lighting to show the presence of a logic `1` voltage signal) on lines PB0 to PB7 and hence encourage and facilitate experimental programming by the user. The additional diodes 66, 67 illuminate to indicate voltage on the 5 V and 12 V lines.
FIG. 10 shows circuitry carried on the mobile device itself. Much of this is on the printed circuit board 43 mounted on top of the device. Leads extend from this to the motors 26 and to the various sensors on the device, as will be referred to again below.
Lines PB0 to PB4 conveying signals from the I/O port are connected to an integrated circuit providing buffers 71. These, in conjunction with pull up resistors 72 convert 5 V signals from the computer to the 12 volt level required for integrated circuits 73L and 73R which energise the stater coils 74 of the stepper motors 26. The 12 volt supply also powers an integrated circuit which provides driver stages 82, 82'.
Line PB3 is used to enable the motors 26. The output from the buffer stage 71 goes to the base of the transistor TR to turn this on, and enable the motor coils to draw current. When the motors are not running line PB3 is used to prevent current flow through the motors, and consequent heating up without interfering with their integrated circuits 73L and 73R. An LED 75 indicates when the motors are enabled.
The presence or absence of voltage signals on PB0 and PB2 sets the directions of rotation of the right and left motors respectively.
Each integrated circuit 73 contains a trigger stage which responds to the leading edge of a voltage pulse on line PB1, a reversible ring counter, and output stages capable of driving current into the motor coils 74. Each voltage pulse on line PB1 causes the ring counter to shift one, in a direction determined by PB0 for 73R and PB2 for 73L. This shift of the ring counter causes the magnetic field of the stator coils to rotate by 7.5°, and a permanent magnet rotor in each motor 26 is carried round by this amount (as is conventional for stepper motors).
Thus if PB0 and PB2 are the same, each voltage pulse in PB1 will cause the motors to rotate through one 7.5° increment, and the module device will move forward or back. However, if PB0 and PB2 are different, each voltage pulse in PB1 will cause the motors to turn the module device 1° around the point 47.
Successive pulses on PB1 cause successive motor increments. The speed of the motors is governed by the frequency of the pulses on PB1.
A possible alternative arrangement would be for PB1 to be corrected to 73R only, while PB3 is connected to 73L, instead being used for turning the motor current off. This would allow either motor to be incremented while the other was stationary, but would leave the motor current on continuously (unless an extra line was used to control this).
Line PB4 is used to operate the pen 81. It is connected through a buffer stage 71 and an inverter 77 to an amplifier which for convenience is two driver stages 82 of an integrated circuit, in parallel. This energises the solenoid 80 unless a logic `1` voltage signal is present on line PB4. This arrangement is employed because a `1` is the default state of PB4 with the computer used.
Lines PB5, PB6 and PB7 are connected to switches 83 on the circuit board 43. These can be used to connect these lines to driver stages 82' (for which the lines must be configured as outputs by the computer software). Such driver stages 82' could operate further devices built onto the chassis structure, such as a grab arm for instance.
Alternatively lines PB5, 6 and 7 can be configured as digital input and used as follows. One of the switches 85 is connected via resistors 86, a capacitor 87 and a Schmitt trigger 88 to the line PB6. The other is similarly connected to line PB7. When a bumper 39 contacts an obstacle and closes a switch 85 it thereby creates a digital input signal to the computer. The device's chassis structure may also carry a tilt switch 78 which would be connected analogously to line PB5.
The light dependent resistor 91 generates a varying voltage on analogue input line CH0. The bar code reader 37 comprises a light emitting diode 93 and a photo-transistor 94 responsive to reflected light and so giving rise to varying voltages on analogue input line CH1.
Analogue inputs CH2 and CH3 are not used, but provision is made for connection of further analogue sensors to them as indicated at 95.
Alternatively to analogue input CH2, a switch 100 to give a digital input can be connected. Resistors, a capacitor and a Schmitt trigger 103 are provided, analogous to 86, 87, 88. The output can be connected to digital input CB1 by breaking connection 104 on the interface board 48, bridging terminals 105 on the interface board 48 and also bridging 106 on the board 43 carried on the device. An inverted signal can be obtained by bridging terminals 107 instead of 106.
In just the same way a switch 102 to give a digital input can be connected to line CB2 in place of analogue input CH3.
In this embodiment the signal carrying link from the interface board to the mobile device is a cable. However, a conceivable alternative would be a short wave radio link, having a transceiver on the interface board and a second transceiver on the mobile device. This would serve to give the mobile device somewhat greater freedom.
The motors 26, the pen solenoid 80 and the various sensors 85, 78, 37, 91 are connected by twisted wires 110 to plugs 112, 113 which engage into respective sockets 114, 115. Sockets 116 incorporate the connections 95 for additional sensors to lines CH2, CH3 or CB1, CB2.
The sockets 114 and plugs 112 are specific to individual sensors/motors/the pen. Socket 115 and plug 113 carry the connections to both switches 85 (for the bumpers).
FIG. 8 shows the physical position of integrated circuits 73, 71, 88 and 82, also the decoupling capacitor C2 across the 12 volt supply line.
The embodiment described above is designed to enable the user to operate the device, and to experiment with it fairly easily and without encountering undue difficulty or having to spend a lot of time on certain items which ought to be straightforward.
Specifically, making the device move through defined distances, or turn through defined angles requires defined numbers of voltage pulses on digital output lines. It is relatively easy for a user to accomplish appropriatc programming of a microcomputer which has such digital output lines. The user is then able to concentrate on programming the computer to perform tasks with the device. The user is able to get on with this rather than getting excessively hindered with accomplishing simple movements, which ought to be nothing more than a preliminary.
The user may wish to change the sensors fitted to the device. One provision for this is the sockets 116 which as described above can carry analogue inputs to lines CH2 and CH3, or can carry digital inputs to lines CB1 and CB2. A further provision is the feature that the sensors are connected through plugs and sockets which are in general individual plugs and sockets for each sensor (although the bumpers have a common plug and socket). This allows a sensor to be disconnected without disturbing the others.
A chassis structure which is compatible with construction kit parts (and indeed is made from them) facilitates adding further structure as required, using further parts from the construction system employed--here Fischertechnik. Thus the user can experiment without spending a lot of time on building any extra structure. The spare driver stages 82' facilitate the addition of further structure which is powered, such as a grab arm.
One particular modification concerns the light dependent resistor 91. In its position shown in the drawings, it can enable the computer to operate the mobile device to search for a light source. It can however also be used to enable the computer to control the mobile device to follow a line. For this the bar code reader 37 is removed entirely (possible because it has its own plug and socket connectors 112, 114). The block 33 which bears the light dependent resistor is removed from its illustrated position, and fitted to the outer end of the hinged arm 34, so that the light dependent resistor faces down towards the line to be followed. The use of construction kit parts makes this modification easy to carry out. | A mobile device to be connected to a home microcomputer is arranged to facilitate and encourage experimentation by the user. The device is largely made from construction kit ports, facilitating modifications and additions to its structure. Drive is provided by stepper motors, with one digital output pulse from the computer causing one increment of motor rotation. This simplifies programming by the user, especially if one pulse is arranged to cause a turn through an integer fraction of a right angle. The device carries a circuit board to which sensors on the device are connected by individual plugs and sockets, enabling one to be disconnected without disturbing the others. An interface board intermediately between the mobile device and the computer collates several cables from the computer parts into one cable leading to the mobile device. | 0 |
BACKGROUND
[0001] The invention relates to a fan housing, and in particular, to a fan housing provided with engaging members.
[0002] FIG. 1 depicts a conventional fan, wherein the fan 1 has a top cover 12 , a base 13 and a motor 14 . The top cover 12 has through holes 121 . The base 13 has holes 131 corresponding to the through holes 121 of the top cover 12 . Screws 15 pass through the through holes 121 into the holes 131 to join the top cover 12 and the base 13 together.
[0003] FIG. 2 depicts another conventional fan, wherein the fan 2 has a top cover 22 , a base 23 and a motor 24 . The top cover 22 has engaging parts 221 . The base 23 has grooves 231 corresponding to the engaging parts 221 of the top cover 22 . The top cover 22 and the base 23 are joined together with the grooves 231 engaged by the engaging parts 221 .
[0004] The described fans present some significant problems. For the first mentioned fan, the screws 15 joining the top cover 12 and the base 13 may loosen after long-term use. Furthermore, screwing is labor consuming. For the second mentioned fan, the engaging parts 221 engaging the grooves 231 may loosen or even break after long-term use. As a possible result, the fan is not maintained in position and the performance of the electronic device beside the fan is negatively influenced.
SUMMARY
[0005] To solve the described problems, the invention provides a fan housing provided with engaging member.
[0006] The fan housing in accordance with an exemplary embodiment of the invention is used to surround a rotor of a fan. The fan housing comprises a first frame and a second frame. The first frame comprises at least one extending part and an engaging hole defined by the extending part. The second frame comprises a guide slot and a protrusion corresponding to the extending part and the engaging hole respectively. The first and second frames are detachably assembled, with the extending part inserted into the guide slot, and the protrusion disposed in the engaging hole. The first frame is a top cover of the fan housing and defines an air inlet. An edge of the air inlet is straight to prevent a backflow in the fan. The second frame is a base of the fan housing, and the first and second frames are assembled via the engaging members to form an air outlet. The second frame comprises an opening serving as an air inlet. The fan is provided with an air inlet or two air inlets. The fan may be a centrifugal fan or an axial fan.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein:
[0008] FIG. 1 depicts a conventional fan;
[0009] FIG. 2 depicts another conventional fan;
[0010] FIG. 3 is an exploded perspective view of a fan in accordance with an embodiment of the invention; and
[0011] FIG. 4 is an exploded perspective view of a fan in accordance with another embodiment of the invention.
DETAILED DESCRIPTION
[0012] Referring to FIG. 3 , a fan 3 in accordance with an embodiment of the invention is a single-intake centrifugal fan which comprises a first frame 31 , a second frame 32 , a stator base 33 , and a rotor 37 .
[0013] The first frame 31 comprises an extending part 311 and an air inlet 314 . The extending part 311 has a first engaging member (e.g. an engaging hole) 312 . The air inlet 314 has a block 315 which is straight to prevent a backflow in the fan 3 . The extending part 311 extends from a periphery of the first frame 31 . The number of the extending parts 311 may be plural. As shown in FIG. 3 , four extending parts 311 are provided in this embodiment.
[0014] The second frame 32 comprises an air outlet 35 and a guide slot 321 corresponding to the extending part 311 of the first frame 31 . A second engaging member (e.g. a protrusion) 322 is provided on an inner wall 3212 of the guide slot 321 . A plurality of ribs 3211 are provided on both side walls 3213 of the guide slot 321 . The protrusion 322 has an inclined surface 3221 . The guide slot 321 and the protrusion 322 are disposed at an outer surface of the second frame 32 . The number of the guide slots 321 and the protrusions 322 may be plural. As shown in FIG. 3 , four guide slots 321 and protrusions 322 are provided in this embodiment.
[0015] When the extending part 311 is inserted into the guide slot 321 , the inclined surface 3221 facilitates the protrusion 322 to engage with the engaging hole 312 . Furthermore, ribs 3211 in the guide slot 321 abut the extending part 311 and help relieve excessive strain.
[0016] The first frame 31 in this embodiment is the top cover of the single-intake centrifugal fan 3 , while the second frame 32 is the base. The stator base 33 is disposed in the second frame 32 for receiving an external stator (not shown). The rotor 37 is disposed around the stator base 33 to generate an interaction therebetween. The first frame 31 and the second frame 32 are assembled via the first engaging member 312 and the second engaging member 322 to house the rotor 37 . Airflow enters the air inlet 314 of the first frame 31 and exits from the air outlet 35 of the second frame 32 . The first and second frames 31 , 32 are both formed by injection molding, pressing or cutting.
[0017] FIG. 4 depicts a dual-intake centrifugal fan 4 in accordance with another embodiment of the invention, wherein the same references will be used for elements which are identical or similar to those shown in FIG. 3 . In this embodiment, an opening serving as another air inlet 36 is provided on the second frame 32 . Thus, airflow enters the air inlets 314 , 36 and exits from the air outlet 35 . The second frame 32 further comprises a plurality of connecting parts 34 connecting the stator base 33 and the second frame 32 . The connecting parts 34 also support the stator base 33 . Furthermore, the air inlet 314 has no straight edge.
[0018] It is understood that various fans (e.g. single-intake centrifugal fans, dual-intake centrifugal fans, and axial fans) are applicable to the invention.
[0019] For both the prior art and the invention, the fan housing provides the rotor of the fan with protection. The fan housing of the invention, however, does not have problems presented in the prior art. The invention prevents using screws for joining the frames loosening after long-term use and the process for screwing required. The invention also avoids the potential breakage of the protrusion and the potential loosening of the protrusion. Furthermore, the invention provides ribs to secure the extending part tightly in the guide slot, even if the guide slot is larger than the extending part due to the manufacturing tolerance. In sum, the invention provides strong engaging members, improves the manufacturing speed and saves labor.
[0020] 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. | A fan housing for surrounding the rotor of a fan. The fan housing has a first frame and a second frame. The first frame includes at least one extending part with a first engaging member. The second frame includes a guide slot and a second engaging member corresponding to the first engaging member to enable the first and second frames to be detachably assembled together. | 5 |
BACKGROUND
[0001] 1. Technical Field
[0002] The present disclosure relates to notebook computers and, particularly, to a notebook computer with a hidden numeric keyboard.
[0003] 2. Description of Related Art
[0004] Generally, in order to reduce the size of a notebook computer, only one keyboard is normally equipped for it, and the separate numeric keypad is often omitted. The keyboard usually includes a number of numeric keys arranged in a line along the length of the notebook computer configured for inputting numbers. However, in some situations, there is a need to frequently input numbers, it is inconvenient and very time-consuming to input the numbers through the numeric keys of the keyboard. As such, the work efficiency of inputting numbers will be less than satisfactory.
[0005] Therefore, it is desirable to provide a notebook computer which can overcome the above-mentioned problems.
BRIEF DESCRIPTION OF THE FIGURE
[0006] Many aspects of the embodiments can be better understood with references to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the embodiments. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.
[0007] FIG. 1 is an exploded, isometric view of a notebook computer according to one embodiment.
[0008] FIG. 2 is an enlarged, isometric view of a portion II of FIG. 1 .
[0009] FIG. 3 is an exploded, isometric view of a support rack, a fastening piece, an adapter, and an auxiliary keyboard of the notebook computer of FIG. 1 .
[0010] FIG. 4 is an exploded, isometric view of the support rack, the fastening piece, the adapter, and the auxiliary keyboard of FIG. 3 , viewed at a different angle.
[0011] FIG. 5 is an assembled, cutaway and isometric view of the notebook computer of FIG. 1 .
[0012] FIG. 6 is an enlarged, isometric view of a portion VI of FIG. 5 .
[0013] FIG. 7 is an isometric view of the notebook computer of FIG. 1 when the auxiliary keyboard is in use.
[0014] FIG. 8 is an isometric view of the notebook computer of FIG. 1 when the auxiliary keyboard is in storage.
DETAILED DESCRIPTION
[0015] Embodiments of the present disclosure will now be described in detail below, with reference to the accompanying drawings.
[0016] Referring to FIGS. 1 and 2 , a notebook computer 1 , according to an exemplary embodiment, includes a display 10 , a main body 12 , a support rack 14 , an adapter 15 , a fastening piece 16 , a cover 17 , a flexible circuit strip 18 , and an auxiliary keyboard 19 .
[0017] The display 10 is a rectangular display screen for displaying the information, for example, a liquid crystal display. The display 10 pivotally connects to the main body 12 . The main body 12 is substantially rectangular and includes a first upper surface 120 , a first side surface 122 , a primary keyboard 120 a , a data port 126 , a power port 127 , a fixing projection 125 , and a lock block 128 . The first side surface 122 perpendicularly connects the first upper surface 120 . The primary keyboard 120 a is formed on the first upper surface 120 and includes a number of main numeric keys and a number of function keys. The main numeric keys of the primary keyboard 120 a are arranged in a line along the length of the main body 12 .
[0018] The main body 12 defines a receiving groove 124 in the first side surface 122 . The receiving groove 124 is substantially rectangular and defines an opening 124 a , a bottom surface 124 b , a pair of parallel inner side surfaces 124 c , and an inner end surface 124 d . The inner side surfaces 124 d perpendicularly connect the bottom surface 124 b . The inner end surface 124 d is substantially opposite to the opening 124 a and perpendicularly connects to the bottom surface 124 b and the inner side surfaces 124 c . The fixing projection 125 perpendicularly extends from one of the inner side surfaces 124 c near the opening 124 a . The data port 126 is formed in the inner end surface 124 d to transmit the data signal with the auxiliary keyboard 19 . The power port 127 is formed in the inner end surface 124 d to supply the power signal to the auxiliary keyboard 19 . The lock block 128 perpendicularly extends outwards from the first side surface 122 adjacent to the fixing projection 125 . The lock block 128 defines a lock groove 128 a therein.
[0019] Also referring to FIGS. 3 and 4 , the support rack 14 is substantially rectangular and includes a bottom wall 140 , a pair of parallel side walls 142 , a rear wall 143 , and a pair of sliding rails 142 a . The side walls 142 are perpendicularly extended from opposite sides of the bottom wall 140 . The rear wall 143 perpendicularly connects the bottom wall 140 and the side walls 142 . The bottom wall 140 , the side walls 142 , and the rear wall 143 cooperatively define an open housing 144 . The sliding rails 142 a perpendicularly protrude from the inner side of each side wall 142 inwardly towards the open housing 144 . Each sliding rail 142 a extends along the side wall 142 in a longitudinal direction of the side wall 142 parallel to the bottom surface 140 . The support rack 14 defines a connecting through hole 143 a in the rear wall 143 near one of the side walls 142 . The support rack 14 defines a pair of fixing through holes 142 b in the opposite side wall 142 away from the connecting through hole 143 a.
[0020] The adapter 15 includes a circuit board 150 , a data interface 152 , a power interface 156 , and a first combined interface 154 . The circuit board 150 is substantially rectangular and similar to the rear wall 143 in shape and size. The circuit board 150 includes a first connecting surface 150 a and a second connecting surface 150 b . The first connecting surface 150 a is parallel and opposite to the second connecting surface 150 b . The data interface 152 is configured for connecting to the data port 126 and forms on the first connecting surface 150 a . The power interface 156 is configured for connecting to the power port 127 and forms on the first connecting surface 150 a near the data interface 152 . The first combined interface 154 is formed on the second connecting surface 150 b . The circuit board 150 combines the data signal from the data interface 152 with the power signal from the power interface 156 and transmits the data signal and the power signal to the auxiliary keyboard 19 through the first combined interface 154 .
[0021] The fastening piece 16 is an elongated flexible strip and includes a main body 160 , a first resilient arm 162 , a second resilient arm 164 , a fastening projection 162 b , and a pair of fixing posts 164 b . The first resilient arm 162 is parallel to the second resilient arm 164 . The first resilient arm 162 and the second resilient arm 164 extend from one end of the main body 160 along the longitudinal direction of the main body 160 . The first resilient arm 162 includes a first outer surface 162 a opposite to the second resilient arm 164 . The fastening projection 162 b perpendicularly extends outwardly from the first outer surface 162 a at a distal end of the first resilient arm 162 away from the main body 160 . The second resilient arm 164 includes a second outer surface 164 a opposite to the first resilient arm 162 . The fixing posts 164 b are formed on the second outer surface 164 a facing to the fixing through holes 142 b . The fastening piece 16 is made of elastic material, such as rubber or synthetic resin. The first resilient arm 162 and the second resilient arm 164 can be bent from the main body 160 .
[0022] The cover 17 is an elongated flat board and includes a connecting end 172 , a lock end 170 , and a lock projection 173 . The lock end 170 is opposite to the connecting end 172 . The lock projection 173 extends from the lock end 170 along the longitudinal direction of the cover 17 .
[0023] The auxiliary keyboard 19 is substantially rectangular and includes a second upper surface 190 , a pair of parallel second side surfaces 192 , a connecting end surface 193 , a second combined interface 193 a , and a number of auxiliary numeric keys 190 a . The second side surfaces 192 perpendicularly connect two opposite sides of the second upper surface 190 . The connecting end surface 193 perpendicularly connects the second upper surface 190 and the second side surfaces 192 .
[0024] The auxiliary numeric keys 190 a are formed on the second upper surface 190 and arranged in rows and columns. The auxiliary keyboard 19 defines a sliding groove 192 a on each second side surface 192 corresponding to the sliding rails 142 a . The second combined interface 193 a is formed on the connecting end surface 193 . The flexible circuit strip 18 is configured for connecting between the first combined interface 154 and the second combined interface 193 a.
[0025] Also referring to FIGS. 5 and 6 , in assembly, the connecting end surface 193 faces the rear wall 143 , the auxiliary keyboard 19 slides into the open housing 144 of the support rack 14 through the engagement between the sliding grooves 192 a and the sliding rails 142 a . The second combined interface 193 a aligns with the connecting through hole 143 a . The first combined interface 154 passes through the connecting through hole 143 a and connects the second combined interface 193 a through the flexible circuit strip 18 . The circuit board 150 is fastened to the rear wall 143 through a pair of bolts. The fixing posts 164 b tightly insert into the fixing through holes 142 b to fasten the fastening piece 16 on the side wall 142 far from the connecting through hole 143 a.
[0026] The rear wall 143 faces the inner end surface 124 d . The fastening piece 16 fastened on the support rack 14 aligns with the fixing projection 125 formed on the inner side surface 124 c . The first resilient arm 162 is bent to the second resilient arm 164 to make the support rack 14 slide into the receiving groove 124 until the fastening projection 162 b moves to the position between the inner end surface 124 d and the fixing projection 125 . Then, the first resilient arm 142 resile to make the fastening projection 162 b resist against the fixing projection 125 and prevent the support rack 14 from dropping out of the receiving groove 124 . The data interface 152 and the power interface 156 correspondingly connect the data port 126 and the power port 127 to transmit the data and the power between the main body 12 and the auxiliary keyboard 19 .
[0027] The connecting end 170 of the cover 17 pivotally connects on the first side surface 122 near the inner side surface 124 c facing the fixing projection 125 . The cover 17 covers the opening 124 a by inserting the lock projection 173 into the corresponding lock groove 128 a to prevent the auxiliary keyboard 19 from dropping out of the support rack 14 .
[0028] Also referring to FIGS. 7 and 8 , when the auxiliary keyboard 19 is in use, the cover 17 is opened and the auxiliary keyboard 19 is pulled out of the receiving groove 124 . The auxiliary keyboard 19 allows the numbers to be easily inputted, because the auxiliary numeric keys 190 a are arranged in rows and columns. When the auxiliary keyboard 19 is in rest, the auxiliary keyboard 19 can be accommodated in the receiving groove 124 to reduce the size of the notebook 1 .
[0029] While various exemplary and preferred embodiments have been described, it is to be understood that the disclosure is not limited thereto. To the contrary, various modifications and similar arrangements (as would be apparent to those skilled in the art) are intended to also be covered. Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements. | A notebook computer includes an main body defining a receiving groove therein, an auxiliary keyboard slidably accommodated in the receiving groove and electrically connected to the input part, and a cover pivotally connected to one side of the opening and configured for covering the opening when the auxiliary is received in the receiving groove. The auxiliary keyboard includes a number of auxiliary numeric keys arranged in rows and columns for inputting the numbers. | 6 |
FIELD OF THE INVENTION
[0001] The present invention relates to filter assemblies for removing particles from an air flow, and more particularly to a filter frame for receiving a media pack, a filter frame assembly, and a method of securing a filter frame assembly to a filter bank.
BACKGROUND OF THE INVENTION
[0002] Filter assemblies comprising media packs disposed in a frame structure are known. A media pack is typically formed from a sheet of filter media, e.g. a fiberglass sheet, or a nonwoven polyester sheet or membrane media or combinations thereof or the like, which is pleated to increase the effective filtering area of the filter body, and provided with cover plates. To provide mechanical support and/or to combine a plurality of media packs, the media pack is typically arranged in a frame structure.
[0003] A prior art filter frame for receiving several media packs is shown in U.S. Pat. No. 6,955,696, which discloses a filter frame comprising two gable plates, which have male connection elements, and two frame beams having female connection elements, which are interconnected with the male connection elements of the gable plates. Thereby a square frame is formed which supports the media packs. In other words, the media packs rest on the frame beams and on support structures of the gable plates. However, that structure requires a high rigidity of the two frame beams and a high stiffness of the media pack due to the small contact area with the frame. It would be desired to be able to mitigate these requirements.
SUMMARY OF THE INVENTION
[0004] It is an object of the present invention to provide a filter frame that eliminates, or at least reduces the drawbacks mentioned above.
[0005] The object is achieved by a filter frame according to the present invention as defined in claim 1 of the appended claims. The object is also achieved by a filter frame assembly as defined in claim 13 and a method of assembling a filter bank as defined in claim 14 of the appended claims.
[0006] Thus, in accordance with a first aspect of the present invention there is provided a V-type filter frame for receiving a filter media pack and arranged to be mounted to a filter bank grid. The V-type filter frame comprises first and second gable plates and a front plate which is coupled to the gable plates. The gable plates each comprises a front edge portion, located upstream an airflow, and an opposite rear edge portion, located downstream an airflow, and an inner surface, facing the inner clean side of the filter assembly, and an outer surface, facing the outer soiled side of the filter assembly. The gable plates further comprises an abutment surface extending outwardly from said outer surface. This abutment surface is arranged to abut a filter bank grid when mounted thereto. The provision of an abutment surface on the gable plate ensures that the forces acting on the filter frame, originating from the air flow through the filter media, can be transmitted by the gable plates directly to the filter bank grid. Many previously known filter frame assemblies are constructed such that the forces are transmitted from the filter media to the gable plates and then forwarded to a front plate and only then to the filter bank grid. That solution makes heavy demands on the adhesive coupling between the gable plates and the front plate which in a worst case scenario could break and in any case there is a immediate risk of air flow leakage between the gable plates and the front plate, which of course is inconvenient in a filter assembly. By directing the forces acting on the gable plate directly to the filter bank grid, as it is done by the present invention, this risk is minimized and the sealing properties of the front plate can be maintained at all times.
[0007] In accordance with an embodiment of the V-type filter frame, the abutment surface is provided in the form of a flange extending along said outer surface.
[0008] In accordance with an embodiment of the V-type filter frame, the abutment surface is provided in the form of a flange extending along at least one side edge of the gable plate.
[0009] In accordance with an embodiment of the V-type filter frame, the gable plate has at least one V-shaped plate portion extending between a front edge portion and an opposite rear edge portion of the gable plate, with the mouth of the V shaped portion facing the front edge portion, said at least one V-shaped portion being defined by a channel arranged to receive a gable of a media pack.
[0010] In accordance with an embodiment of the V-type filter frame, the front plate comprises a sealing surface arranged to abut a filter bank grid. The provision of a sealing surface on the front plate ensures optimal sealing properties between the filter bank grid and the filter frame.
[0011] In accordance with an embodiment of the V-type filter frame, the sealing surface of the front plate is arranged to be substantially flush with the abutment surface of the gable plate. This means that while the gable plates will carry the main loads occurring during use of the filter assembly, the front plate will still carry a minor amount of the loads such that sealing between front plate and filter bank grid can be is ensured.
[0012] In accordance with an embodiment of the V-type filter frame, a sealing member is provided at the sealing surface of the front plate.
[0013] In accordance with an embodiment of the V-type filter frame, the sealing member comprises a compressible sealing strip.
[0014] In accordance with an embodiment of the V-type filter frame, the sealing surface of the front plate is arranged outwardly adjacent the abutment surface of the gable plate.
[0015] In accordance with an embodiment of the V-type filter frame, the front plate is coupled to the gable plates by means of a snap-lock element. A mechanical locking element such as a snap-lock will allow a person working with the mounting of the filter assembly to handle the frame assembly even before an adhesive has been supplied thereto.
[0016] In accordance with an embodiment of the V-type filter frame, the front plate is coupled to the gable plates by means of an adhesive. The provision of an adhesive has a number of advantages. Among others, the adhesive provides excellent sealing properties such that no air can escape between the gable plates and the front plate. Further, it holds the gable plates and the front plate together. In combination with the snap-lock element, the mere presence of an adhesive in the space between gable plates and front platewill ensure that the snap-lock element cannot snap out of its locked position, thereby increasing the rigidity of the structure.
[0017] In accordance with an embodiment of the V-type filter frame, a rear plate is engaged with rear edge portions of the first and second gable plates by means of a snap lock element. Similar to the use of snap-lock element between the front plate and gable plates, this makes the structure easier to handle during assembly.
[0018] In accordance with second aspect of the present invention, a filter frame assembly comprising a filter frame as described herein and at least one media pack arranged in the filter frame is provided.
[0019] In accordance with third aspect of the present invention, a method of assembling a filter bank is provided. The method comprises the following steps:
[0020] providing a filter bank grid comprising at least one opening for a filter frame;
[0021] providing a V-type filter frame comprising a front plate and first and second gable plates mounted to the front plate, wherein said gable plates comprises an abutment surface extending outwardly from an outer surface thereof and wherein the front plate comprises a sealing surface;
[0022] providing a media pack in the filter frame;
[0023] mounting said filter frame with media pack to the filter bank grid such that the abutment surface of the gable plates and the sealing surface of the front plate abut the filter bank grid.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The invention will now be described in more detail and with reference to the appended drawings in which:
[0025] FIG. 1 a is a schematic exploded view of an embodiment of a filter assembly according to the invention;
[0026] FIG. 1 b is a perspective view of the filter assembly of FIG. 1 a;
[0027] FIGS. 2 a - 2 f are schematic views of filter frame parts of the filter assembly.
[0028] FIG. 3 is a schematic cross-section of filter frame parts according to the invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0029] According to an embodiment of the filter assembly 100 , it comprises an embodiment of the filter frame 102 , and several, in this embodiment six, media packs 104 carried by the filter frame 102 whereby the media packs 104 have been shown separately in FIG. 1 a for reasons of clarity. The media packs 104 can be of any suitable kind, but typically each media pack 104 comprises a sheet of filter media 106 , which has been pleated to an accordion shape in order to increase the effective filtering area of the filter body, and backing nets 108 containing the pleated sheet of filter media 106 . Backing nets 108 are arranged to let air pass through the filter media 106 , or even arranged to guide the passing air in a preferred direction and optimized for low pressure drop thereover.
[0030] The filter frame 102 comprises a front plate 110 , two gable plates 112 , and a rear plate 114 , embodied by three separate plate elements 116 . The front plate 110 is rectangular and comprises a peripherally extending rim 118 , and parallel ribs 120 extending between opposite ends 122 , 124 of the front plate 110 . The front plate 110 has a groove 126 at each of the ends 122 , 124 . Each groove 126 extends along a respective portion of the rim 118 at an inside thereof, and adjacent thereto. The gable plates 112 are arranged at the opposite ends 122 , 124 of the front plate 110 . Each gable plate 112 has a front edge portion 128 , which has been received in the groove 126 . Each gable plate 112 extends perpendicular to the front plate 110 , and rearwards therefrom. The media packs 104 are plate shaped and extend obliquely substantially in the direction of the air flow from the front plate 110 , although they extend close to perpendicular to the front plate 110 . The media packs 104 are arranged side by side, leaning alternately to one side and to the other side, thereby forming a zigzag structure. More particularly, they are arranged in pairs, each pair forming a V shape, such that the mouth of the V shape faces the front plate 110 . A front edge 132 of each media pack 104 abuts against one of the ribs 120 , and apertures 130 between the ribs 120 are aligned with the mouths of the V shapes. Each gable plate 112 has three V-shaped portions 134 extending between the front edge portion 128 and an opposite rear edge portion 136 of the gable plate 112 , with the mouth of each V-shaped portion 134 facing the front edge portion 128 . The V-shaped portions 134 are joined along a minor fraction of their length, extending from the mouth towards the other end, while there are gaps between them along a major part of their length. Reinforcing elements 154 may be provided extending between two adjacent V-shaped portions to further increase the structural rigidity of the gable plate 112 . These reinforcing elements 154 can also serve as grips when handling the gable plates 112 or (semi-) assembled filter frame assemblies 100 . Each V-shaped portion 134 is defined by a channel, having side walls 138 . Each V-shaped channel has received gable portions, or side edge portions, 140 of two media packs 104 . Of course, it is also possible within the scope of the appended claims for the gable plates 112 to have additional or less than three V-shaped portions, such as one, two, four or more. Also, the gable plates 112 may not have V-shaped portions at all but may for example be provided in the form of covering having a trapezoid shape or similar without openings between adjacent pairs of media packs. Each plate element 116 of the rear plate 114 covers rear edge portions 142 of two media packs 104 forming a V-shape. The plate elements 116 each extend between, and are attached to, a respective fraction of the rear edge portion 136 of each gable plate 112 . Consequently, the front plate 110 , the gable plates 112 , and the rear plate 114 support each other to form a strong filter frame 102 , which carries the media packs 104 .
[0031] An important part of the filter frame structure is the engagement between the gable plates 112 and the front plate 110 . As mentioned above, each one of the gable plates 112 has been received in a respective groove 126 of the front plate 110 . In order to secure a proper engagement between the front plate 110 and the gable plates 112 , each gable plate is provided with a retainment member 144 , and the front plate 110 is provided with a complementary retainment member 146 for each gable plate 112 . The retainment member 144 of each gable plate 112 comprises a snap-lock element 148 at either side of the gable 112 , and more particularly at each end of the front edge portion 128 , at a side edge 129 , 131 of the gable plate 112 . The snap-lock element 148 comprises a resilient tongue 152 , which extends perpendicular or at an angle to a front edge of the gable plate, and which has a shoulder 156 . The complementary retainment member 146 comprises a recess 158 , which is arranged at the rim 118 of the front plate 110 . The shoulder 156 has been received in the recess 158 . Thereby the gable plate 112 is in fixed engagement with the front plate 110 . However, in order to further enhance the stability of the engagement, the retainment member 144 further comprises three protrusions 160 , which protrude from the front edge portion 128 perpendicular to the primary extension of the gable plate 112 . The protrusions 160 are distributed along the length of the front edge portion 128 . The complementary retainment member 146 further comprises three notches 162 , which are arranged at the rim 118 of the front plate 110 , one notch at each respective protrusion. The protrusions 160 have been received in the notches 162 . Each protrusion 160 is wedge-shaped, and each notch 162 is V-shaped. The sizes of the protrusions 160 and the notches 162 are such that they are connected to each other in a press fit when the gable plate 112 is inserted into engagement with the front plate 110 . The snap-lock elements 148 and the press fit connection between the protrusions 160 and notches 162 ensure a reliable coupling between the gable plates 112 and the front plate 110 even without the use of any adhesives such that the filter frame can be handled, e.g. lifted and moved around, without the need of any temporary securing means or similar. It should be noted that as regards the retainment member 144 , the number of protrusions 160 can range from zero to several, and the number of snap-lock elements 148 can range from zero to several as well. It is desired to have at least one snap-lock element or protrusion, and it is preferred to have two snap in elements with the shown placement and at least one protrusion.
[0032] In FIG. 3 it is shown that the gable plates 112 each comprises an abutment surface 184 near the front edge portion 128 . This abutment surface 184 is intended to bear against a filter bank grid 200 , made for example from steel beams, when mounted thereto. The front plate 110 is provided with a sealing surface 186 having a sealing member 188 , here in the form of a sealing strip made from polyurethane or similar. The sealing surface 186 is flush with the abutment surface 184 when the gable plates 112 are mounted to the front plate 110 such that both surfaces will bear against the filter bank grid when mounted thereto. It should be noted that in FIG. 3 , for reasons of clarity, the abutment surface 184 of the gable plate 112 and sealing surface 186 of the front plate 110 is not yet in contact with the filter bank grid 200 . Instead, FIG. 3 shows a position where the sealing member 188 barely touches the grid 200 . It is also possible, and sometimes preferable, to arrange the sealing surface 186 of the front plate 110 forwardly displaced relative the abutment surface 184 . If, for example, a thick and/or less compressible sealing member 188 is used, too much load may be transferred to the front plate 110 if the sealing surface 186 and abutment surface 184 are arranged flush with each other. By arranging the sealing surface 186 somewhat forwardly displaced relative the abutment surface 184 , the abutment surface 186 will reach the front surface of grid 200 earlier, thus not requiring excessive compression of the sealing member 188 . As will be described below, the filter frame assembly is to be fastened by means of clamps or similar that firmly squeeze the filter frame assembly against the filter bank grid 200 . When this is done the sealing member 188 will be compressed and the abutment surface 184 of the gable plate will bare against the filter bank grid 200 in a load absorbing manner. This results in that the forces originating from the air flowing through the filter media will be transmitted directly from the media pack 104 to the gable plates 112 and thereafter to the filter bank grid and only a minor part of these forces, if any at all, will be transmitted to the filter bank grid by the front plate 110 . This is favorable since the connection and sealing between the front plate 110 and gable plates 112 will not be exposed to any substantial stress thereby avoiding air leakage between them. The abutment surface 184 is here executed in the form of a flange running the whole width of a front part of an outer side of the gable plate 112 as well as on the side edges 129 , 131 . This ensures uniform load transfer and good sealing properties between sealing surface 186 and the filter bank grid 200 . Other forms of execution of the flange are of course possible, for example in order to increase structural stability of the flange.
[0033] The filter frame is assembled as follows. The front plate 110 , comprising the grooves 126 at the two opposite ends 122 , 124 thereof is provided. The first and second gable plates 112 are provided and mounted at the front plate 110 . For each gable plate 112 the mounting includes inserting a front edge portion 128 of the gable plate 112 into a respective groove 126 , and forcing the retainment member 144 into engagement with the corresponding retainment member 146 of the front plate 110 . Thereby a part of the filter frame 102 which is ready to receive the media packs 104 has been assembled. In order to complete the assembling process to a complete filter assembly 100 , the next step thus is to mount the media packs 104 including backing nets 108 , and then the plate elements 116 of the rear plate 114 are mounted, wherein they are forced into engagement with the rear edge portions 136 such that snap-lock elements 192 of the gable plates 112 snaps into a locking position in the corresponding part in each rear plate 116 . As mentioned earlier, the filter assembly is now ready to be handled and could for example be transported to a different location without the necessity of any temporary securing means or similar. And then, in a last step of assembling the filter frame, an adhesive is used to seal and fixate the filter frame 102 . The mere presence of adhesive in the spaces between the different constructional details will prevent the snap-lock elements from leaving their locked position, which adds rigidity to the structure even before the adhesive has cured. Obviously, curing will further increase rigidity and stability of the structure by bonding the gable plates 112 and the front plate 110 together. Since the retainment member 144 will be glued into engagement with the corresponding retainment member 146 the snap-lock connection and press fit connection respectively will become even stronger. Other modes of mounting are obviously also possible, such as intermediate supply of adhesive.
[0034] Thereafter, the filter frame assembly is inserted and secured to the filter bank grid 200 , typically the filter frame assembly is clamped to the filter bank grid 200 by means of a plastic or metal clamp which is fixed to the filter bank grid by means of a bolt and a fly nut or similar. Thereby, the filter frame assembly can be tightly squeezed between the clamp and the grid 200 without the use of through bolts or similar that would jeopardize tightness of the construction. When doing so, both the abutment surface 184 of the gable plate 112 and the sealing surface 186 of the front plate 110 are pressed against the filter bank grid 200 such that sealing is assured. When in use, the forces acting on the filter media 106 due to the air flow therethrough will be transmitted directly from the gable plates 112 to the filter bank grid 200 and no major forces will be transmitted from the gable plates 112 to the front plate 110 such that the sealing properties between the gable plates 112 and the front plate 110 can be maintained at all times.
[0035] Finally, it is realized that the use of structure of the present invention with retainment members 144 , 146 is a more user-oriented solution than known prior art constructions since it allows for a user to handle the frame assembly without the need of any temporary securing means or similar before the adhesive has been added and allowed to cure. Further, the provision of an abutment surface on the gable plate and a sealing surface on the front plate provides a construction with increased load bearing capacity while at same time improving sealing properties of the filter frame assembly. It should also be noted that the positions of the retainment member and the complimentary retainment member could be altered, e.g. the snap-lock could just as well be arranged on the front edge of the gable plate and the protrusion on the side edge of the gable plate and the corresponding goes for the complimentary parts of the front plate. | A V-type filter frame is disclosed for receiving a filter media pack. The V-type filter frame is arranged to be mounted to a filter bank grid and includes first and second gable plates and a front plate coupled thereto. The gable plates each include an abutment surface extending outwardly from an outer surface arranged to abut a filter bank grid when mounted thereto. A filter frame assembly and a method for assembling a filter bank are also disclosed. | 8 |
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation of copending International Application No. PCT/DE00/04591, filed Dec. 22, 2000, which designated the United States and was not published in English.
BACKGROUND OF THE INVENTION
Field of the Invention
The invention relates to an optical signal transmitter device, in particular for traffic signaling systems.
In conventional signaling technology for road or rail traffic, a powerful light source with small dimensions, such as the filament of an incandescent lamp, is normally placed at the focal point of an optical condenser, and is projected to infinity. The high light density of the light source results in a very high light intensity within a relatively small and standardized emission angle range, so that the signal can still be identified well, even from a long distance.
However, incandescent lamps are known to have a limited life, and the failure of the incandescent lamp that is used for a signaling device is always associated with a total failure of the entire signaling device. The incandescent lamps that are used, for example, for warning signal devices must therefore be replaced as a precautionary measure at regular time intervals. These time intervals are far shorter than the average life of the lamp, so that their replacements are associated with considerable use of material and take a considerable amount of time.
Similar problems also arise with other control signaling devices, because of the use of conventional incandescent lamps as light sources.
Because of the high failure rate of convention incandescent lamps, it is thus advantageous to use semiconductor light emitting diodes (LEDs) as light sources, since LEDs not only have a considerably longer life, but also more efficiently convert electrical energy into radiated energy in the visible spectral band. Associated with this increased efficiency is a reduced heat emission and a smaller space requirement overall. However, in order to provide an LED arrangement which is suitable for a traffic signaling device or a comparable signaling device, it is likewise necessary in the same way as for the conventional traffic signaling or railroad signaling device to use optics which are suitable for focusing the light that is emitted from the individual LEDs such that, even at a relatively long distance, it is perceived as a light source with a physical extent and as a bright light. Signaling transmitters for road traffic are subject to detailed and standardized optical requirements with regard to the emission characteristic, light density distribution, and phantom light. The term phantom light refers to the simulation of a switched-on signaling light by incident sunlight that is reflected from an internal reflector.
Known structures for road traffic signals with an LED light source may be rotationally symmetrical, as a result of which a specific proportion of the emitted light disappears. Furthermore, this can result in problems with phantom light. Other known structures have complicated optics, which make it more difficult to produce a signal transmitter insert at low cost.
Published European Patent Application EP 0 860 805 describes signal transmitter optics in which a large number of light elements are arranged in the interior of a signal chamber, and thus form an essentially flat light body instead of the previously normal incandescent lamps. These light elements emit light that is directed in the direction of a scattering lens, even without using a reflector. The light source is composed of at least three individual light elements, which emit at least the majority of their light to the lens system, where it is gathered and focused by a common condenser, and is distributed by the scattering lens in accordance with chosen requirements. However, this arrangement has the disadvantage that a scattering lens with optical characteristics must be used in order to define an emission characteristic. The production of such a scattering disk with optical characteristics and its installation in the two-stage optical structure are, however, relatively complicated and, in consequence, costly.
SUMMARY OF THE INVENTION
It is accordingly an object of the invention to provide an optical signaling device which overcomes the above-mentioned disadvantages of the prior art apparatus of this general type.
In particular, an object of the present invention is to specify an optical signaling device, in particular for road traffic signals, which supplies a required emission characteristic or light density distribution using methods which are as simple and uncomplicated as possible.
In particular, another object of the present invention is to specify an optical signaling device that can achieve a required emission characteristic or light density distribution even without using a scattering disk with optical characteristics.
A further object of the present invention is to develop a signaling device of this generic type such that the light that is emitted by the LEDs can be gathered more efficiently by the optical arrangement.
The present invention accordingly describes an optical signal transmitter device having two or more light elements which are arranged on a base plate, and having a condenser which is arranged at a fixed distance from the light elements on an optical axis, in order to project the light which is emitted from the light elements to infinity.
On the basis of this arrangement, each light element has an associated emission direction, so that the light density in a specific emission direction is largely decoupled from the light density distribution for other emission directions. This arrangement advantageously allows a specific predetermined emission characteristic or light density distribution to be achieved solely by the arrangement of the light elements on the base plate.
The invention has the major advantage that a specific, required emission characteristic or light density distribution can be achieved in an optical signal transmitter device by using a considerably simplified optical configuration. Specifically, there is no need for the scattering disk, as is absolutely essential in the prior art, for producing the light distribution.
A standard Fresnel lens may be used as the condenser. The Fresnel lens projects the light source to infinity. However, in order to ensure that the bridge system of the arrangement of the light elements is not imaged at infinity, the condenser can be arranged at a distance from the plane of the light elements such that the light elements are located slightly away from the focal plane of the condenser. As an alternative to this, the focusing condition can also be satisfied exactly using optical structures for deliberate defocusing, in particular by arranging spherical lenses on the condenser, in particular, on its surface facing the light elements.
In a further embodiment, the invention describes an optical signal transmitter device having two or more light elements that are arranged on a base plate, and having a condenser which is arranged at a fixed distance from the light elements on an optical axis, in order to project the light which is emitted from the light elements to infinity. A specific predetermined emission characteristic or light density distribution is achieved by the arrangement of the light elements on the base plate and/or by the optical characteristics of a scattering lens that may be provided, in accordance with chosen requirements, and with the condenser being convex.
An optical signal transmitter device such as this has a considerably more efficient light gathering characteristic. In this case as well, the condenser is preferably formed from a Fresnel lens. Since Fresnel lenses can be produced particularly advantageously from plastic using the injection molding process for applications such as these, curved Fresnel lenses can also be produced with relatively few problems.
These LEDs, in particular SMT-compatible LEDs, are preferably used as the light elements. In this case, an LED structure is preferably used as described in the article “SIEMENS SMT-TOP-LEDs for surface mounting” by F. Möllmer and G. Waitl in the journal “SIEMENS Components” 29 (1991), issue 4, page 147, and as illustrated in FIGS. 1A , B there. On this basis, the base plate according to the present invention is preferably a panel, in particular a panel with a metal core, which may additionally be fitted to a suitable heat sink in order to improve the heat dissipation further.
Alternatively, LED semiconductor bodies can also be used as light elements that are fitted directly to the base plate. This means that the LED semiconductor bodies are mounted as such on the base plate and are not, as is otherwise normal, installed in housings that are mounted on the base plate. A chip-on-board technology is preferably used for directly mounting the LED semiconductor bodies. For mounting purposes, the LED semiconductor bodies can be soldered to the base plate, or can be adhesively bonded to it using an electrically conductive adhesive.
In one embodiment that is preferably used for road traffic lights, the optical signal transmitter device does not transmit any light in the obliquely upward direction, so that sunlight, which is likewise but conversely also incident obliquely upward, cannot strike the light elements, so that they cannot produce any phantom light. In order in addition to avoid the occurrence of phantom light reflections in all other feasible embodiments, the base plate can also be colored black away from the light elements.
In one advantageous development of the invention, the light elements are connected electrically in parallel or in series. Parallel connection in this case has the advantage that the signal transmitter device remains operable even in the event of failure of individual light elements.
Once connected in series, the signal transmitter circuit can be supplied with higher operating voltages, with a reduced operating current. The voltages and currents that are required for this purpose can advantageously be provided more easily from the conventional supply networks.
In order to combine both advantages, it is particularly preferable for the light elements to be grouped in two or more parallel circuits, which are in turn connected in series. Alternatively, the light elements can be combined to form two or more series circuits, with are in turn connected in parallel.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in an led signaling device for road traffic signals, 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 DRAWINGS
FIG. 1 is a schematic illustration of one exemplary embodiment of an optical signal transmitter device;
FIG. 2 is a section illustration of a further exemplary embodiment of an optical signal transmitter device;
FIG. 3 is a perspective illustration of a further exemplary embodiment of an optical signal transmitter device;
FIG. 4 is a plan view of a panel containing a conductor track structure for holding light elements; and
FIGS. 5A and 5B are circuit diagrams showing two electrical circuit variants of the light elements of an optical signal transmitter device.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the figures of the drawing in detail and first, particularly, to FIG. 1 thereof, there is shown a perspective illustration of a first exemplary embodiment of an inventive optical signal transmitter device. Two or more light elements 2 such as light emitting diodes (LEDs) are arranged distributed in a predetermined manner on a base plate 1 , which is preferably a panel such as a panel with a metal core or the like. This distribution determines the emission characteristic or light density distribution of the optical signal transmitter device. The base plate 1 can be fitted to an additional metallic heat sink 5 , in order to additionally upgrade the heat dissipation from the LEDs, so that they can be operated with higher currents, thus making it possible to increase the light yield. The base plate 1 can be held in plug-in apparatus with an opening in the form of a slot, which plug-in apparatus is at the same time used as the voltage supply for the LEDs.
A condenser 3 , preferably a Fresnel lens, is arranged at a predetermined distance from the base plate 1 on an optical axis A, such that the optical axis A passes through its center point. A standard Fresnel lens can be used as the Fresnel lens, which is normally produced from plastic using the injection molding process, and which is in the form of a circular disk with a standard diameter of 200 mm. The object of the condenser 3 is to project the light that is emitted from the LEDs to infinity. A shutter disk 4 can also be used behind the condenser 3 in the emission direction. The scattering disk that is used at conventional road traffic signals can be used as the shutter disk 4 , even though it no longer has any significant influence on the initial characteristic.
It is advantageous for only the light density distribution of the LEDs to be projected to infinity, but not the point matrix of the LEDs. That is to say to incorrectly carry out the optical imaging. One way to achieve this is to incorrectly arrange the base plate 1 on the focal plane of the condenser 3 .
Another variant is illustrated in FIG. 2 . In this arrangement, the base plate 1 and the LEDs 2 are seated exactly on the focal plane of the condenser 3 which, however, additionally has small optical structures 3 A on its surface facing the LEDs 2 , which lead to deliberate defocusing. The optical structures 3 A are preferably formed by small spherical lenses, which are not associated with the individual LEDs, and have a focal length that is short in comparison with the distance between the base plate 1 and the condenser 3 . In particular, it has been found that, with a standard traffic signaling system, spherical lenses with a focal length of ⅙ of the distance between the base plate and the condenser can advantageously be used, by virtue of the dimensions that are provided by them.
The arrangements that are illustrated in FIGS. 1 and 2 , which do not have any complicated optical structures, can be used to provide a light intensity and light density distribution in accordance with the standards. Since the emission area is restricted virtually exclusively to the spatial area underneath the optical axis A, there is no need to be concerned about the interference reflections from phantom light sources (solar radiation) which inject radiation into the signal transmitter device from above the optical axis A, since the radiation of a light source which injects radiation into the signal transmitter device from above is focused by the Fresnel optics at a point which is located outside the LED arrangement on the base plate 1 . For additional suppression of phantom light reflections, the base plate 1 may also be colored black at various points at which no LEDs are located.
FIG. 4 shows an exemplary embodiment of a metallization structure 100 on a panel for fitting SMT-compatible Power-TOPLEDs®. LEDs such as these normally have one anode connection and three cathode connections, so that four connecting pads are required for each LED. One LED is thus soldered on using an SMT process for each illustrated group of four connecting pads. The resultant distribution of the LEDs results in the signal transmitter device having an emission characteristic in accordance with the standards. The large-area connection pads +/− result in electrical contact being made with the entire electrical circuit in the plug connector. The use of such small standard LEDs allows the use of a large number of mutually independent individual LEDs, owing to their small physical size, thus ensuring the functionality of the signal, despite the possible failure of individual LEDs. The current passes through in a suitable manner. This aspect is particularly important for use in rail traffic areas (level crossings), since the signals are subject to particularly stringent standard operational safety requirements in this case.
The emission characteristic of the optical signal transmitter device according to the present invention can be adjusted more exactly via the arrangement of the light elements than via complicated optical structures. All that is necessary is to arrange the LEDs on the base plate 1 , and to use standard Fresnel optics. The closing scattering disk which is normally always installed in traffic-light and signaling systems can still be used, since it no longer makes any significant contribution to the light distribution.
FIG. 3 illustrates a further aspect of the present invention, which may regarded as being independent of the way in which the emission characteristic or light density distribution is achieved. A signal transmitter device as shown in FIG. 3 has a base plate 1 and two or more light elements 2 arranged on it. A condenser 3 , preferably a Fresnel lens, is arranged at a distance from it on an optical axis A, and its object is to project the light which is emitted from the light elements 2 to infinity. The base plate 1 together with the light elements 2 is arranged essentially on the focal plane of the Fresnel lens. In order to increase the light gathering characteristic of the Fresnel lens, this lens is convex. In other words, the Fresnel lens is shaped in such a way that lines which run from the center point to the edge describe an arc round the base plate 1 , that is to say they are curved in the direction of the base plate 1 .
Since a circular standard Fresnel disk is used as the Fresnel lens and is produced from a plastic using the injection molding process, a disk such as this can be produced relatively easily with any desired curvature. The use of a Fresnel lens such as this thus makes it possible to increase the light yield from an optical signal transmitter device constructed according to the invention.
The two aspects of the present invention can also be combined with one another. A convex condenser 3 , as described in FIG. 3 , can accordingly also be used with an embodiment of an optical signal transmitter device as illustrated in FIGS. 1 , 2 and 4 .
FIGS. 5A and 5B show two advantageous variants of a signal transmitter device constructed according to the invention. In FIG. 5A , 100 LEDs are combined in 20 series circuits, which each contain 5 LEDs. These 20 series circuits are operated connected in parallel.
In the circuit shown in FIG. 5B , 10 LEDs of 100 are in each case connected in parallel. Five of these parallel circuits are in each case combined to form two series circuits, which are in turn driven in parallel. | The invention describes an optical signal transmitter device, in which a specific, predetermined emission characteristic or light density distribution is achieved solely by the arrangement of two or more light elements on a base plate. This means that there is no longer any need for complicated optical structures in order to produce the predetermined light distribution. The invention furthermore describes an optical signal transmitter device that uses a convex condenser in order to improve the light gathering characteristic. | 5 |
This is a division of application Ser. No. 078 823 filed July 28, 1987.
BACKGROUND OF THE INVENTION
The present invention relates to implantable materials for replacement of fibrous or cartilaginous tissue. More particularly, the present invention relates to a method of making hydrophilic polymeric implants having controlled pore size which can be shaped and used to replace fibrous or cartilaginous tissue in animals and man.
For many years people have been searching for materials useful as replacements for different types of tissue. Materials tried include silicones, acrylates and other plastics, and metals. While each of these materials has certain advantages, some problems have developed in use. For example, silicone becomes hardened and displaced over time so its use as a breast augmentation implant, while tried often in the 1960's, has declined. Similarly, although metals and some plastic materials have been used for joints and other bone replacements, rejection problems have limited the use to those with no other alternatives. Plastics have also been tried as both soft and hard tissue replacements but there have been similar problems.
Because of these problems with the materials tried to date, a great detail of attention has been focused on modified plastics, particularly the acrylates and methacrylates, for implantation. Because of their transparent nature and easy moldability, there has been special emphasis on the dental and optical uses of the acrylate family. The optical uses have included scleral buckles and lens replacements while the dental area has focused on tooth and alveolar ridge replacement. In addition, some work has been done on breast or soft tissue replacement using acrylates and methacrylates. The acrylates and methacrylates, when implanted in a porous form, show tissue ingrowth and/or calcification which may support or harden the implant; in many cases, this ingrowth or calcification has been problem.
The Kroder et al. U.S. Pat. No. 3,628,248 is an example of the uses tried for the acrylates and methacrylates. This patent discloses a process for forming artificial implants, preferably for dental uses, using a variety of plastics, most preferably the acrylates and methacrylates. Kroder attempts to encourage tissue growth into the material using a porous surface. They obtain a porous surface by mixing potassium chloride in the acrylate monomer before polymerization. The potassium chloride is then leached out of the outer surface, leaving pores. However, the initiator used by Kroder as a hydrophobic could cause problems with tissue rejection. The use of hydrophobic plastics such as that shown by Kroder could also produce problems with rejection since there cannot be any transfer of electrolytes across the implant.
U.S. Pat. No. 4,199,864, issued on application by Ashman, attempted to cure the problems with the Kroder material. Ashman used polymethyl methacrylate as a dental implant material, and tried to form a porous surface by mixing a salt with the hydrophobic material. In fact, Ashman also lined the mold before polymerization with the salt crystals to provide surface porosity. Ashman found that even doing this, a "skin" formed over the plastic so it was necessary to grind off the outer layer of the material to expose the crystals. After exposure, Ashman let the material soak in water in an attempt to leach the salt crystals out. However, this just removed the salt from the outer layer because of the hydrophobicity of the material. Again, the hydrophobic material itself could still cause rejection problems.
To U.S. Pat. No. 4,536,158, issued to Bruins and Ashman and assigned to the same assignee as the Ashman patent, the same polymethyl methacrylate material was used for a dental implant. In this patent, the hydrophobic material was coated with a small amount of a hydrophilic methacrylate, hydroxyethyl methacrylate (HEMA) in an attempt to reduce rejection. The Bruins et al. patent describes using the material for replacing bone for dental applications. Very small particles of the coated hydrophobic material is made into a porous filler by packing the particles so that pseudopores are formed between the individual particles. While this approach is fine for a nonweight bearing application, its overall usefulness is limited. This material is sold commercially by Medical Biological Sciences, Inc., under the trade name HTR.
Others have used acrylates in various ways in order to replace bone or fibrous tissue. For example, U.S. Pat. Nos. 3,609,867 and 3,789,029 both issued to Hodash, concern an acrylate/ground bone mixture while U.S. Pat. No. 3,713,860, issued to Aushern, discloses a mixture of a porous aluminum oxide and a methyl methacrylate polymer to form a bone replacement substitute.
None of these bone or fibrous tissue substitutes have solved all the problems with rejection and controlled ingrowth. Accordingly, HEMA has been one of the newer materials tried for a variety of implantation and surgical uses. For example, in U.S. Pat. No. 4,452,776, issued on an application of Refojo, HEMA is used not only as a replacement for acrylates for contact lenses but also as a scleral buckle. HEMA has also been used as a breast augmentation material and as a dental implant. See Kronman et al., "Poly-HEMA Sponge: A Biocompatible Calcification Implant", Biomat., Med. Dev., Art. Org., 7(2):299-305 (1979). HEMA has been used as an implant material in both a porous and nonporous state. However, the only method of obtaining porous HEMA has been to polymerize the hydroxyethyl methacrylate monomer about water molecules. For example, the Kronman et al. article discusses both 70/30 and 80/20% HEMA/water mixtures. Polymerizing about water molecules forms micropores within the hydrophilic HEMA but it does not allow any way to control the pore size with accuracy. Further, there is no way of being sure that the pores range throughout the material.
Problems with uncontrolled pore size besides the question of whether the pores are evenly distributed throughout the material include the problem that the properties of HEMA after implantation are different depending upon pore size. For example, with a pore size of 60-150μ, calcification takes place, leading to a bone-like implant. If the pore size is between 225 to 275μ, the properties of the material after implantation are similar to those of cartilage while a pore size of 300 to 450μ yields a fibrous-like tissue, similar to fibrous connective tissues.
Accordingly, an object of the invention is to provide a method making a material for forming implants of a biocompatible material which does not cause rejection and promotes ingrowth without calcification.
Another object of the invention is to provide a method of forming a biocompatible fibrous tissue replacement.
A further object of the invention is to provide a biocompatible and shapable cartilaginous implant material with a variety of uses, e.g., nasal augmentation, cartilage reshaping, and ear replacement.
A still further object of the invention is to provide a biocompatible synthetic replacement for fibrous, connective tissue which could be used for soft tissue augmentation, e.g., breast augmentation.
These and other objects and features of the invention will be apparent from the following description and the drawings.
SUMMARY OF THE INVENTION
The invention disclosed herein provides a method of making a biocompatible microporous implant having controlled pore size for replacement of fibrous or cartilaginous tissue in an animal, particularly man. The invention also features the implant itself as well as it uses, e.g., breast augmentation, nasal augmentation or reshaping, and ear replacement or augmentation.
The microporous implantable material of the invention is formed by dispersing crystals of a water-dissolvable material, preferably a crystalline salt such as sodium chloride, potassium chloride or calcium chloride, in an unpolymerized hydrophilic polymerizable monomer. To make synthetic cartilaginous material, crystals of the water-dissolvable material ranging from about 225 and 275μ in diameter are mixed with the monomer while 300 to 450μ crystals are used for fibrous, connective tissue material. The hydrophilic polymerizable monomer is polymerized about the crystals to form a hydrophilic polymeric material having crystals dispersed therethrough. The resulting material is contacted with a sufficient amount of an aqueous solution to dissolve the crystals, thereby forming a polymerized microporous material having micropores of about 225 to 450μ in diameter at the locations where the crystals had previously been. This microporous material is then formed into the implant of the invention.
The monomers may be any hydrophilic acrylates or methacrylates but are preferably hydroxyalkyl acrylates to methacrylates, most preferably hydroxyethyl methacrylate. The hydrophilic polymeric material may consist of a mixture of the hydrophilic materials but a homopolymer of hydroxyethyl methacrylate is preferred. The polymerization reaction is carried out using standard methods, e.g., using an initiator, heat polymerication, or UV radiation.
The ratio by weight of the hydrophilic polymeric material after polymerization to the crystal can be controlled to produce the properties desired, e.g., changes in weight ratio can lead to either cartilaginous or fibrous connective tissue. In addition, the ratio of salt volume to polymer volume can be used to determine some properties of the resulting material.
The invention also features an implant for replacement of either fibrous or cartilaginous tissue made by the method of the invention. If the implant is made having micropores ranging from about 225 to about 275μ, it forms a cartilaginous-like material. This material is particularly well adapted for a nasal implant and the same type of cartilaginous replacement material may be used for an ear implant. The nasal implants for the invention are useful for augmentation, enhancing, or reshaping of deficient or misformed appendages while the ear implants have similar broad spectrum uses. In addition, the ear implants can form complete ear replacements.
If the larger pore sizes are used, e.g., about 300 to 450μ in diameter, a synthetic fibrous connective tissue is formed instead of cartilaginous tissue. This fibrous connective tissue is useful for breast augmentation or reshaping. This method is particularly well adapted for replacement of a breast which has been removed due to a mastectomy.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a flow chart showing the steps in the manufacturing process for the implant of the present invention; and
FIG. 2 shows a cross-section comparison of the material of the present invention with the prior art Ashman material.
DESCRIPTION
As noted, the present invention features a method of producing biocompatible implants for replacement of fibrous connective and cartilaginous tissue. The implants of the invention promote tissue ingrowth without undergoing bone-like hardening due to calcification. The invention provides a method of producing micropores of controlled size dispersed throughout a hydrophilic material, yielding an implant which is biocompatible and has pores necessary for tissue ingrowth throughout the implant. Controlling the pore size permits control of the properties of the final material since changes in the amount of fibrous or tissue ingrowth changes the texture of the sponge-like replacement material. In this manner, one can produce synthetic cartilage or fibrous connective tissue under controlled conditions. This method prevents the calcification or other hardening which occurs in many other types of implants and thereby limits their usefulness.
FIG. 1 is a schematic diagram of the method of the invention. Crystals of a water-dissolvable material, preferably a salt such as sodium chloride, are milled into a controlled size selected depending on the type of tissue desired to be replaced. If the type of tissue being replaced is cartilaginous, e.g., a nasal implant for replacement of nose cartilage, the pore size of the salt crystals should be about 225 to 275μ in diameter. Salt crystals of that size would be selected so that upon solubilization, they would leave the desired pores. The salt crystals are mixed with an unpolymerized monomer of the implant material, e.g., hydroxyethyl acrylate.
One method exemplary of the invention has sodium chloride crystals milled to a size of about 250 μ dispersed throughout a solution of unpolymerized hydroxyethyl methacrylate. Approximately 67.8 g of sodium chloride is dispersed in 150 ml of the hydroxyethyl methacrylate monomer in a 200 ml beaker, yielding a final volume ratio of 75% plastic, 25% salt after polymerization. One method of keeping the salt crystals in a solution is by a magnetic stirrer which disperses the crystals in an even manner throughout the solution while it is undergoing polymerization. Alternatively, the materials are mixed and placed in a beaker or ampule. In either case, the solution is bubbled with nitrogen for thirty minutes, then sealed and polymerized. Polymerization is carried out in a conventional manner, e.g., using an initiator such as benzoyl peroxide but for some uses heat or UV polymerization is preferred since there cannot be any initiator remaining after polymerization which can cause rejection effects in the body.
A preferred polymerization technique has the sealed solution polymerized with an initiator in a thermostat at 60° C. for approximately ten hours. Approximately 5-10×10 -3 mole of the initiator, preferably methyl azo-bis isobutyrate is used per 1,000g of monomer. See "Effect of the Structure of Poly(Glycol Monomethacrylate) Gel on the Calcification of Implants", Sprincl, Kopecek and Lim, Calc, Tiss. Res. 13:63-72 (1973), for exemplary procedures of polymerization.
The procedures described will yield a clock of the polymer with the salt crystals dispersed therein. Accordingly, it is necessary to remove the salt crystals in order to form the micropores. Since the polyhydroxyethyl methacrylate is hydrophilic, contacting the material with an aqueous solution leaches the salt crystals. The hydrophilic characteristics of the material allows the aqueous solution to permeate the material and dissolves the salt crystals from the entire body of the implant, as well as allowing the dissolved salt to flow freely from the material. Leaching of the salt crystals can be carried out by placing the material in a large excess of water or another aqueous based solution, preferably at an elevated temperature. It is also possible to use a flow system which constantly replenishes the aqueous solution, keeping the salinity of the surrounding water down and yielding better salt dissolution kinetics.
In one exemplary procedure, the block of polymerized material is placed in a 200 ml beaker under running water for about one hour. The block is removed, rinsed and allowed to stand in fresh water for about ten minutes. A pH meter with an ion probe is used to test for ion concentration, indicating whether salt is still leaching. If no salt is detected, the material can be shaped but if ions are detected, further soaking is used to leach the remaining salt.
Leaching the salt crystals from the polymerized material leaves a microporous material having pores where the salt crystals were previously. The salt is dissolved throughout the entire material because of the hydrophilicity of the material so the resulting material has pores throughout. In a hydrophobic material, such as that used by Ashman, the water cannot permeate past the outer layers of material and therefore salt crystals are entrapped within the body of the hydrophobic implant material. The entrapped salt cannot be contacted by the liquid and cannot dissolve. Accordingly, a cross-section of the Ashman-type material will have pores only on the outer layer. The portion of FIG. 2 labeled Prior Art illustrates the Ashman material. In fact, since a film or outer coating may form over the material during polymerization, it may be necessary to grind the outer surfaces of the material in order to obtain access to any of the salt crystals if a hydrophobic material is used. This type of grinding is specifically described in Ashman; this is necessitated by his choice of materials.
In contrast, the material of the present invention will have pores throughout. The portion of FIG. 2 marked Present Invention shows the extent of the pores using the method described herein.
Once one obtains the microporous material, the implant is then shaped in a conventional manner, e.g., cutting or grinding. An advantage of the material of the invention is that once formed, the gel is sponge-like so shaping can be carried out by carving with a scalpel or scissors. The Refojo U.S. Pat. No. 4,452,776, has a description of other ways of forming poly-HEMA into a proper shape. For certain uses, it may be possible to form a mold to the proper shape and polymerize the material directly in that mold. Such preshaping is included within the present invention.
The implantation techniques using the material of the invention include those currently known and are not in and of themselves part of the present invention. Common cosmetic surgery techniques for replacement or augmentation of tissue have been described in the literature and need not be described further herein. However, the materials of the present invention is biocompatible and has pores which allows for ingrowth of fibrous or cartilaginous-type tissue which allows implantation without the problems caused by tissue rejection. In part, rejection is minimized because the hydrophilic nature of the material used herein allows free flow of electrolytes and liquids across the implant. In fact, HEMA has been used as a coating on a number of metal or plastic implants in order to minimize rejection.
The uses set forth herein, e.g., nasal augmentation and enhancing, ear augmentation and reshaping, and breast augmentation, are exemplary only and others skilled in the art will determine other uses and modifications of the method and implant disclosed herein. Such other modifications and uses are within the scope of the following claims. | Disclosed is new type of implantable material for replacement of cartilaginous or fibrous tissue. The material has controlled porosity and is biocompatible. A method for making this material is also disclosed. | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a rear suspension for a motor vehicle.
2. Description of the Prior Art
There has been known an automotive rear suspension of the type as disclosed in U.S. Pat. No. 4,269,432 in which the rear suspension includes a wheel support for rotatably supporting the rear wheel, a pair of front and rear lateral links for supporting the wheel support on the vehicle body so that it is swingable in the vertical and longitudinal directions of the vehicle body, and a trailing link for supporting resiliently either one of the wheel support and the connecting portion of the lateral links with the wheel support so that the wheel support is allowed to travel a short distance in the longitudinal direction of the vehicle body. The distance between the outer connecting points of the lateral links with the wheel support is set to be smaller than that between the inner connecting points thereof with the vehicle body. Alternatively, the front lateral link is set to be shorter than the rear lateral link. By these arrangements, when rearward forces such as a braking force act on the rear wheels, the support member for the rear wheel is caused to travel rearward, and the rear wheel changes in position in the direction of the toe-in. Thus, vehicle motional stability is obtained.
Recently, developments have been made in rear suspension systems of the above-mentioned types so that a vehicle body displays desired characteristics according to motional conditions by means of toe-control of the rear wheels relative to lateral forces acting thereon. Such toe-control can be obtained by setting the characteristics of either the front or rear suspension system to be non-linear in repsonse to lateral forces acting on the rear wheel. For example, U.S. Pat. No. 4,621,830 discloses this type of automotive rear suspension which is desirably applied to a front-engine, front-wheel-drive type of motor vehicle which exhibits a tendency toward excessive under-steer when the magnitude of the lateral force is large. The suspension includes a front lateral link system, whose deformation characteristics are set to be non-linear. More specifically, a bush disposed between the lateral link and the vehicle body is set to exhibit a non-linear deformation characteristic. When the lateral force acting on the rear wheel becomes extremely large, such as during a sudden turn or changing of lanes at high speed, the rear wheel is controlled in its attitude so as to decrease the change in the toe-out direction, that is, to weaken the understeer characteristics so that drivability is improved, while driving stability is ensured with the application of a small magnitude of lateral force, or when the vehicle is moving at medium or low speed.
In a suspension system as described above, when the rear wheels are subjected to rearward force, the wheel supports for the rear wheels are caused to travel in the rearward direction to produce a toe-in movement therein. At the same time, there are produced deformations caused by the elastic deformation of the bushes etc. in the front and rear lateral link systems, whereby the rear wheel tends to produce a toe-out movement. In order to produce a toe-in movement in the rear wheel under the application of a rearward force, the magnitude of the toe-in must be larger than that of the toe-out. However, where the deformation characteristics of the lateral link systems are set to be non-linear so as to control the toe direction relative the lateral force, the change in the toe-in movement in the rear wheel, which is caused by deformation in the lateral link systems, also exhibits non-linear characteristics. No consideration has been taken of this point, namely, the change in the toe movement in the rear wheel produced by the rearward force acting on the rear wheel. Hence, there remains a possibility that, when a rearward force of a certain magnitude acts on the rear wheel, the change in the toe-out direction of the rear wheel caused by the deformation in the lateral link systems can become larger than that in the toe-in direction thereof caused by the rearward traveling of the wheel support, by which the rear wheel can be undesirably changed in its attitude in the toe-out direction.
SUMMARY OF THE INVENTION
In view of the foregoing observations and description, a primary object of the present invention is to provide an automotive rear suspension having lateral link systems which exhibit a non-linear deformation characteristic with respect to both lateral and rearward forces acting on the rear wheels, in which the toe movement in the rear wheel can be desirably controlled, whereby vehicle motional stability can be ensured under all motional conditions.
To accomplish the above object, in the present invention, the rear wheel support is arranged so as to travel rearward under the application of a rearward force acting thereon to thereby produce a toe-in movement in the rear wheel, the amount of the toe-in movement being controlled to be larger than that of toe-out movement produced by the deformation in the lateral link systems. According to one aspect of the present invention, there is provided an automotive rear suspension system which comprises a wheel support member for supporting the rear wheel rotatably, a pair of front and rear lateral link means supporting the wheel support member on the vehicle body so that it is swingable in both the vertical and longitudinal directions of the vehicle body, and a trailing link means for resiliently supporting either the wheel support member or the connecting portion of the lateral link means with the wheel support member so that the wheel support member is allowed to travel a certain distance in the longitudinal direction of the vehicle body. The front and rear lateral link means are arranged so as to produce a toe-in movement in the rear wheel when the rear wheel is subjected to a rearward force. At least one of the front and rear lateral link means is set to exhibit a non-linear deformation characteristic with respect to a lateral force acting on the rear wheel. The trailing link means is also set to have a non-linear deformation characteristic responding to that of the lateral link means.
According to the suspension with the above arrangement, when rearward force acts on the rear wheel, the front and rear lateral link means are deformed to produce a toe-out movement on the rear wheel. This change in the toe-out direction exhibits a non-linear relationship with the rearward force on the basis of the non-linear deformation characteristics of the lateral link means. At the same time, the trailing link means is deformed to move the wheel support rearward, which produces a toe-in movement in the rear wheel which is in accordance with the non-linear deformation characteristics of the trailing link means. Therefore, by setting the desired relationship between the non-linear deformation characteristics of the lateral link means and those of the trailing link means, the rear wheel can be reliably controlled in the toe direction so as to produce a toe-in movement irrespective of the amount of the rearward force acting thereon. Further, the deformation characteristics of the trailing link means is set to be non-linear with respect to rearward forces acting thereon, so that this deformation characteristic does not adversely affect the riding comfort of the vehicle. In addition, the trailing link means does not have any effect on the toe control of the rear wheel when lateral force is applied thereto, which means that only the lateral links means control the toe movement in the rear wheel with a given non-linear characteristic. Hence, the toe movement in the rear wheels can be desirably controlled with respect to lateral forces acting thereon.
Other objects and the advantages of the present invention will become apparent from the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic plan view of an example of a rear suspension in accordance with the present invention;
FIG. 2 is a rear elevational view of the rear suspension shown in FIG. 1;
FIG. 3 is a sectional view of an example of a bush which can be employed in the lateral link means and the trailing link means of the suspension shown in FIG. 1;
FIG. 4 is a cross-sectional view of the bush taken along the line 4--4 in FIG. 3;
FIG. 5 is a sectional view of an example of a bush having a non-linear deformation characteristic which can be employed in the lateral link means and the trailing link means in the suspension of FIG. 1;
FIG. 6 is a cross-sectional view of the bush taken along the line 6--6 in FIG. 5;
FIG. 7 is a sectional view of a bush having a non-linear deformation characteristic which can be employed in a trailing link means of the divided type;
FIG. 8 is a sectional view of another type of bush which can be employed in a trailing link means;
FIG. 9 shows the deformation characteristics of the lateral link means which can be provided with the suspension of the present invention;
FIG. 10 shows the deformation characteristics of the trailing link means which can be employed in a suspension with a lateral link means, the characteristics of which are shown in FIG. 9;
FIG. 11 shows changes in the toe movement in the rear wheel respect to lateral force in one example of a suspension according to the invention;
FIG. 12 shows change in the toe movement in the rear wheel with respect to rearward force in one example of the suspension;
FIG. 13 shows the deformation characteristics of the lateral link means which can be provided with the suspension of the present invention;
FIG. 14 is a cross-sectional view of a bush having a non-linear deformation characteristic which can be employed in the suspension of the invention;
FIG. 15 is a sectional view of the bush taken along the line 15--15 in FIG. 14;
FIG. 16 is a cross-sectional view of a bush having a non-linear deformation characteristic which can be employed in the suspension of the present invention;
FIG. 17 is a sectional view of the bush taken along the line 17--17 in FIG. 16;
FIG. 18 shows change of the toe movement in the rear wheel with respect to lateral force in another example of the suspension;
FIG. 19 shows the deformation characteristics of the lateral link means and the trailing link means with respect to lateral force in another example of the invention;
FIG. 20 shows a cross-sectional view of another example of a bush which can be employed in a suspension of the invention;
FIG. 21 is a sectional view of the bush taken along the line 21--21 in FIG. 20;
FIG. 22 is a sectional view of another example of bush which can be provided in a trailing link means of the divided type; and,
FIG. 23 shows another embodiment of a suspension according to the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
While the present invention will be described in connection with preferred embodiments, it will be understood that we do not intend to limit the invention to these embodiments. On the contrary, we intend to cover all alternatives, modifications, and equivalents as may be included within the spirit and scope of the invention as defined by the attached claims.
Now referring to the drawings, FIGS. 1 and 2 illustrate an embodiment of an automotive rear suspension system having a shock absorber means of the strut type. The suspension system includes a wheel support 1 for supporting a rear wheel 2 rotatably and a pair of front and rear lateral links 3 and 4 extending in the lateral direction of the vehicle body 9 between the wheel support 1 and the vehicle body 9. The front lateral link 3 is conneced at the outer end to the front of the wheel support 1 via a bush 5 and is connected at the inner end to the vehicle body 9 via a bush 7 so that it is swingable in the vertical direction and in the longitudinal direction of the vehicle body by the elastic deformation of the bush 7. Likewise, the rear lateral link 6 is connected at its outer and inner ends via bushes 6 and 8 to the rear of the wheel support 1 and to the vehicle body in a similar manner to the front lateral link 5. The front and rear lateral links 5, 6 are arranged so that the distance between the outer connecting points, the bushes 5 and 6 is smaller than that between the inner connecting points, the bushes 7 and 8, to thereby define a trapezoidal configuration with the wheel support 1 and the vehicle body 9.
A trailing link 10 is disposed to extend in the longitudinal direction of the vehicle body between the heel support 1 and the vehicle body 9 and is connected at its front end with the vehicle body via a bush 11 and at its rear end with the lower end of the wheel support 1 via bush 12. By the elastic deformation of the bushes 11, 12, the trailing link 10 supports the wheel support movably in the longitudinal direction of the vehicle body. A shock absorber 13 is disposed between the upper end of the wheel support 1 and the vehicle body 9, and comprises a strut 13a and a coil spring 14 disposed coaxially around the rod of the strut 13a.
As shown in FIG. 9, the front lateral link system that includes bushes 5 and 7 is set to have a deformation characteristic which is different from that of the rear lateral link system that includes bushes 6 and 8. The deformation of the front lateral link system is set to exhibit a substantially linear relationship with lateral force acting on the rear wheel, as shown by the line A. Whereas, the deformation characteristic of the rear lateral link system is set to be non-linear, having two bending points a1 and a2 with respect to the lateral force as shown by the line B. The characteristic lines A and B intersect at two points, b1 and b2, which means that the amount of the deformation in the front lateral link system is larger than that in the rear lateral link system when the magnitude of the lateral force is below b1 and above b2, while it is smaller than that in the rear lateral link system when the magnitude of the lateral force is between b1 and b2.
FIG. 10 shows the deformation characteristic of the trailing link system which includes the bushes 11 and 12. As can be seen, it is set to be non-linear, having two bending points with respect to tensile force acting on the trailing link system, which responds to the non-linear characteristic of the rear lateral link system shown by the line B in FIG. 9. In order to obtain this characteristic, the trailing link system exhibits a relatively high elastic modulus in the regions c and e where the tensile force is small and large, respectively, while it exhibits a relatively low elastic modulus in the region d between the regions c and e.
Next, there will be described the constitution of the rear lateral link system and the trailing link system for obtaining the above-mentioned non-linear characteristic having two bending points. One example of this is to provide the bush 8 or bush 10 with a non-linear deformation characteristic, while the bushes 6, 12 and 5, 7 are provided with a linear deformation characteristic. An embodiment of such a bush having a linear characteristic is shown in FIGS. 3 and 4. The bush is of a common type and comprises an inner tube 15, an outer tube 16 and a rubber member 17 between the outer and inner tubes. An embodiment of the bushes 8 and 10 is shown in FIGS. 5 and 6. The bush comprises an outer tube 15, an inner tube 16 and a rubber member 17 provided with a void 18 of an arcuate section, and a pre-compressed portion 19. The arcuate void 18 is formed in one side of the rubber member relative to the inner tube 15 and is positioned on the axial line 4a or 8a of the rear lateral link 4 or the trailing link 10. The pre-compressed portion 19 is positioned on the opposite side of the void 18 relative to the inner tube 15, which is in the form of a protrusion as defined by a pair of grooves 20, 20 and is pre-compressed in the radial direction of the inner tube 15 so as to position the inner tube relative to the outer tube 16. The bush exhibits a small change in deformation due to the pre-compression of the rubber member when the force acting thereon along the axial line 4a or 10a is lower than that of all shown in FIG. 9, and a large change in deformation due to the collapse of the void 18 in the rubber member when the force is between the points a1 and a2. It again exhibits a small change in deformation after the void is completely collapsed and the force exceeds the point a2.
Another embodiment of the trailing link system having a non-linear characteristic relative to the tensile force, that is the rearward force acting on the rear wheel, will be explained. As shown in FIG. 7, a lateral link of a divided type is employed in the trailing link system. The lateral link comprises a front link member 21 and a rear link member 22, the rear end of the front link member 21 being provided with a cylinder 23 opening rearward and the front end of the rear link member 22 being provided with a piston 24 inserted into the cylinder 23 slidably. The piston 24 is prevented from coming out of the cylinder 23 by a cap member threaded into the opening of the cylinder so as to maintain the connecting condition of the front and the rear link members 21 and 22. A coil spring 26 is disposed in the cylinder in a compressed condition so as to force the piston 24 against the bottom surface of the cylinder 23. A tubular elastic member 27 is disposed around the coil spring 26 with the bottom surface being mounted on the cap member 25 and the end surface being spaced apart from the piston 24 by a distance L. In this divided type trailing link, when the trailing link system is being subjected to a relatively small rearward force, the coil spring is not compressed in its length due to the pre-compression thereof. Therefore, the trailing link system exhibits a relatively high elastic modulus defined by the bushes disposed at each end of the trailing link 10. After the tensile force caused by the rearward force becomes larger than the pre-compression force of the spring 26, the spring 26 begins decreasing in length with the relatively low elastic modulus thereof. Thus, the trailing link system exhibits a relatively low elastic modulus defined by the spring 26. After the spring 26 has been reduced in length by L and the piston 24 has abutted against the elastic member 27, the trailing link system exhibits a relatively high elastic modulus defined by the elastic member 27 and the coil spring 26.
The rear lateral link system having a non-linear characteristic can also be realized by employing a lateral link of the divided type, an embodiment of which is shown in FIG. 8. The lateral link comprises a wheel-side member 41, a vehicle-body side member 42 and a connecting portion 43 thereof. The connecting portion comprises a cylinder 44 formed on the end of the vehicle-body side member 42 and a piston 45 formed on the end of the wheel-side member 41 inserted into the cylinder slidably. Between the cylinder and the piston, a pre-compressed rubber member 46 is disposed so that it is in contact at both end surfaces with the piston and the cylinder. A hard rubber member 47 is disposed around the pre-compressed rubber member 46 so that it is in contact at one end surface with the cylinder 44 and is spaced at the other end surface from the piston 45 by a distance L2. According to this arrangement, the pre-compressed rubber 46 is not deformed until the force exceeds the value all. The piston comes in contact with the hard rubber 47 when the force becomes equal to the value a2. After that, the hard rubber 47 is deformed.
In operation, the lateral force acts on the rear wheel and is transmitted through the wheel support 1 to the front and rear lateral link system as equal compression forces. The deformation characteristic of the front lateral link system differs from that of the rear lateral link system as shown in FIG. 9, so that the rear wheel is controlled in the toe movement according to the characteristic line shown in FIG. 11. The points a1, a2, b1 and b2 correspond to those in FIG. 9. As shown by the characteristic line, the front lateral link system is deformed more than the rear lateral link system when the lateral force is relatively small, so that the rear wheel is moved in the toe-in direction, whereby straight stability of the vehicle can be ensured. When the lateral force is medium in magnitude, the front lateral link system is deformed less than the rear lateral link system, which results in a decrease in the tendency of toe-in movement in the rear wheel or produces a toe-out movement of the rear wheel. Therefore, turning ability and steering ability can be improved. In other words, toe-in movement in the rear wheel is reduced so that the under-steering tendency is weakened compared to when the toe-in movement is large, so that the steering response can be improved. When the lateral force becomes large, the toe-in movement in the rear wheel is again produced to thereby present an under-steering tendency, whereby driving stability is obtained during sharp turns and lane changes at high speed.
In operation, where a rearward force F such as a braking force acts on the rear wheel, a tensile force f1 is applied to the trailing link system, a tensile force f2 is applied to the front lateral link system, and a tensile force f3 is applied to the rear lateral link system. The magnitudes of these forces can be defined by the following formulas.
f1=F×(H1/H2)
f2=f3=F×(m/1)
wherein H1 is the height from the ground to the top of the shock absorber 13, H2 is the height from the connecting point of the trailing link 10 to the wheel support 1 (the bush 12) to the top of the shock absorber 13, 1 is the distance in the longitudinal direction between the connecting points of the front and rear lateral links with the wheel support, and m is the lateral distance from the connecting point between the trailing link 10 and the wheel support 1 to the line extending through the top of the shock absorber 13 and the center of the tread surface of the rear wheel 2.
The front and rear lateral link systems are deformed by the forces f1 and f2 to produce the toe-out movement in the rear wheel. The trailing link system is deformed by the force f3 to allow the rear wheel to move rearward, so that the toe-in movement in the rear wheel is produced. Hence, the toe movement of the rear wheel 2 depends on whether the magnitude of the toe-in movement produced by the lateral link systems is larger or the toe-out movement produced by the trailing link system is larger. Since the rear lateral link system is set to have a non-linear characteristic with two bending points, the toe-out movement of the rear wheel is produced along the non-linear line X having two bending points as shown in FIG. 12 with respect to the rearward force F. On the contrary, since the trailing link system is set to have a non-linear characteristic having two bending points in response to the non-linear one of the rear lateral link system, the wheel support is moved rearward to produce the toe-in movement in the rear wheel along the line Y having two bending points as shown in FIG. 12. Accordingly, where the rearward force acting on the rear wheel is lower than the force F max, the toe-in movement in the rear wheel 2 produced by the movement of the rear wheel rearward is controlled to be larger than the toe-out movement thereof produced by the lateral link systems. Hence, the rear wheel can be maintained in toe-in condition relative to the rearward force acting thereon. Further, the deformation characteristic of the trailing link system is not only set to produce a larger toe-in movement but also set to be non-linear so as to respond to the non-linear toe-out movement in the rear wheel produced by the lateral link systems. Therefore, the deformation characteristic of the trailing link system does not adversely affect the vibration-preventing ability thereof, and the driving quality can be maintained in the desired condition.
Further, it can be suppressed that the non-linear deflection of the lateral link system affects the toe-in movement of the rear wheel caused by a rearward movement of the wheel. Thus, a desirable toe-in movement property can be obtained.
In the above-mentioned suspension, the front lateral link system is set to have a linear deformation characteristic and the rear lateral link system is set to have a non-linear one with two bending points in order to produce the toe-in movement in the rear wheel as defined by the line in FIG. 11. Alternatively, both the front and rear lateral link systems can be set to have a non-linear deformation characteristic having only one bending point as shown in FIG. 13.
In FIG. 13, the front lateral link system has a non-linear deformation characteristic defined by the line C having a bending point a3, whereas the rear one has a non-linear deformation characteristic defined by the line D having a bending point a4. These characteristic lines C and D intersect at two points b3 and b4 and therefore the amount of deformation in the front lateral link system is larger than that in the rear lateral link system where the lateral force acting on the rear wheel is lower than the value b3 and higher than the value b4, while the former is smaller than the latter where the lateral force is between the values b3 and b4. As will be understood, the points b3 and b4 correspond to the points b1 and b2 in FIGS. 9 and 11, and so the toe control of the rear wheel relative to the lateral force can be carried out according to the characteristic line shown in FIG. 11 in a similar manner as aforementioned.
There will be described arrangements of the lateral link system having a non-linear characteristic with one bending point. One embodiment of such lateral link systems is such that the front and rear lateral link systems are provided with bushes as shown in FIGS. 14, 15 and 16, 17 as the bushes 7 and 8 at their body-side ends, respectively.
The bush shown in FIGS. 14, 15 applied as the bush 7 comprises an inner tube 15, an outer tube 16 and a rubber member 17 between the tubes. The rubber member is formed with a pair of first voids 28 of an arcuate section extending along its axis on opposite sides relative to the inner tube 15. The voids 28, 28 are positioned on the axial line 3a of the lateral link 3. At the middle of one of the voids 28, 28, second voids 29 are provided in the form of an arcuate groove. When the lateral force is small, the change in deformation of the bush is large due to the existence of the voids 28, 28, whereas after the voids are collapsed, the change in deformation thereof becomes small. However, due to the existence of the voids 29, the change in the deformation is still relatively large compared to that produced when a solid rubber member is provided (refer to the line C in FIG. 13).
The bush shown in FIGS. 16, 17 applied as the bush 8 has a similar structure to that of the bush shown in FIGS. 14, 15 except that the second void 29 is not provided. Owing to the absence of the void 29, the deformation characteristic of this bush is smaller than that of the bush having the void 29 until the voids 28 are collapsed and also continues to be smaller after the voids 28 have collapsed, as shown by the line D in FIG. 13.
Although the above-mentioned embodiments, the toe control of the rear wheel relative to the lateral force is carried out in three different modes according to the magnitude of the lateral force, it can alternatively be carried out in two different modes. In a front-engine, front drive vehicle, for example, the tendency toward under-steer becomes undesirably strong as the lateral force becomes large. The suspension system used in such a vehicle should desirably produce a toe-out movement in the rear wheel, namely should weaken the tendency toward under-steer when the lateral force is extremely large during sharp turning and lane changes at high speed, whereas it should produce a toe-in movement in the rear wheel when the lateral force is small during lane changes at medium or low speed. This characteristic of the toe movement is shown in FIG. 18.
To this end, the deformation characteristic in the rear lateral link system is set to be substantially linear as shown by the line E in FIG. 19 and that in the front lateral link system is set to be non-linear as shown by the line F in FIG. 19. As the lines E and F intersect at the point b5, the front lateral link system produces a deformation larger than that produced in the rear lateral link system when the lateral force is below the value b5, whereas it is smaller than that produced in the rear lateral link system when the lateral force is larger than the value b5. In addition, the deformation characteristic of the trailing link system is set to be non-linear in response to the non-linear deformation characteristics of the front lateral link system in order to produce a toe-in movement in the rear wheel when the rear wheel is subjected to a rearward force.
These deformation characteristic can be realized by, for example, the following arrangement. Namely, the front lateral link 3 and the trailing link 10 is provided at their vehicle-body side ends with the bushes 8 and 11 having the structure shown in FIGS. 20 and 21. The bush is provided with a rubber member 17 between inner and outer tubes, which comprise a pair of arcuate voids 30, 30 on the opposite side with respect to the inner tube 15 positioned on the axial line 3a or 11a. In the voids 30, 30, a pair of arcuate rubber members 31, 31 of hard synthetic resin are disposed to adhere to only the outer surface of the inner tube 15, whereby a pair of voids are defined between the outer surface of the arcuate rubber members and the inner surface of the outer tube 16.
Alternatively, the trailing link may be of a divided type as shown in FIG. 22 so as to provide a deformation characteristic having one bending point. As shown in FIG. 22, this type of trailing line has a similar constitution to that of the trailing link shown in FIG. 7 except for the absence of the resilient member 27.
In the above-mentioned embodiments, the connecting points, bushes 5 and 6, of the front and rear lateral links 3 and 4 to the wheel support are positioned so that the distance between them is larger than that of the connecting points, bushes 7 and 8, of the lateral links 3, 4 to the vehicle body to thereby produce a toe-in movement in the rear wheel when the rear wheel is subjected to rearward force. Alternatively, the front lateral link 3 may be shorter in length than the rear lateral link 4 and arranged substantially in parallel, as shown in FIG. 23. Or, they may be arranged so as to be apart from each other toward the vehicle-body side. | An automotive suspension comprises a wheel support for rotatably supporting a rear wheel, a pair of front and rear lateral link systems for supporting the wheel support on the vehicle body so that it is swingable on the vertical and longitudinal directions of the vehicle body and producing a toe-in movement in the rear wheel when the rear wheel is subjected to rearward force, and a trailing link system for supporting resiliently either one of the wheel support and the connecting portion of the lateral links with the wheel support to the vehicle body so that the wheel support is allowed to travel a short distance in the longitudinal direction of the vehicle body. At least one of said front and lateral link systems is set to exhibit a non-linear deformation characteristic with respect to lateral force acting on the rear wheel. The trailing link system is set to exhibit a non-linear deformation characteristic which has a given relation with said non-linear deformation characteristic of said lateral link system. The suspension can produce a toe-in movement in the rear wheel with respect to the rearward force so that vehicle motional stability as well as riding comfort can be improved. | 5 |
FIELD OF THE INVENTION AND RELATED ART STATEMENT
1. Field of the Invention
The present invention relates to a suspension control apparatus for a controlling a vehicle posture by changing damping force of a shock absorber to keep a wide road contact area with the vehicle tires and to decrease a vibration of the vehicle when the vehicle is driving on an undulating road (bumpy road).
2. Description of the Related Art
When a vehicle is driving on a very bumpy road, the vehicle makes periodic rolling motions due to vibration of the tires in a vertical direction, through receipt of severe shock. The result is that the road contact area of the tires decreases. This makes driving stability and riding comfort poor during bumpy-road driving such that the vehicle receives continuous vibrations or shocks.
In order to solve such problems, a conventional suspension control apparatus detects the vibration of the vehicle or shock, by inferring from a change of the vehicle height or a change of stroke of shock absorbers. The damping force of the shock absorbers for restraining the vibration or shock is controlled by signals in response to the change of the vehicle height or the change of stroke of the shock absorbers during bumpy road travel. The result is that driving stability and riding comfort are improved.
However, in case of measuring the distance between the bottom of vehicle body and road surface in order to detect the change of vehicle height, the distance measuring instrument, e.g. ultra-sonic sensors, have to be mounted on the vehicle body near the road surface. Therefore, the ultra-sonic sensors are liable to be covered with mud, dust or snow, and the ultra-sonic sensors will malfunction. Even if the ultra-sonic sensors are operated in a clean state, output signals from the ultra-sonic sensors may show an incorrect vehicle posture, because the output signals only represent the interval (distance) between the road surface and the part of vehicle body where the ultra-sonic sensor is mounted.
In the conventional suspension control apparatus wherein the stroke of the shock absorber is detected, as a voltage output with a variable resistor in order to detect the vehicle height. This has some problems in that a sliding part of the variable resistor may wear away. Furthermore, plural detecting devices are mounted on plural shock absorbers, respectively, and the signal processing needs become a complicated operation. Therefore, such conventional suspension control apparatus lacks durability and reliability.
The Japanese published unexamined patent application No. Sho 63-68413 (Tokkai Sho 63-68413) discloses another conventional suspension control apparatus having a vehicle speed sensor and three angular velocity sensors for directly detecting a vehicle motion behavior. The three angular velocity sensors detect a yaw angular velocity, a pitch angular velocity and a roll angular velocity. Thereby the vehicle behavior is grasped and the damping force of the shock absorber is controlled in response to the vehicle behavior.
The above-mentioned yaw angular velocity is an angular velocity in a rotation about a vertical line (yaw axis) at a center of the vehicle. The pitch angular velocity is an angular velocity in a rotation about a lateral axis (pitch axis) of the vehicle. The roll angular velocity is an angular velocity in a rotation about a longitudinal axis (roll axis) of the vehicle.
This conventional suspension control apparatus (Tokkai Sho 63-68413), which operates to decrease a rolling motion of the vehicle behavior by using these signals from three angular velocity sensors, has the following problems. An arithmetic unit in the conventional suspension control apparatus carries out a complicated computing operation using the output signals from the yaw angular velocity sensor, the pitch angular velocity sensor and the roll angular velocity sensor. Therefore, this suspension control apparatus needs a considerable time for computing data. For example, when a CPU (Central Processing Unit) of 8 bits is used as the arithmetic unit, the operation time for computation of a control signal, namely, the time period between reception of detection signals and issuance of output signal to the actuators takes about 20 msec. Therefore, the conventional suspension control apparatus requires the use of a higher speed CPU as the arithmetic unit, (i.e. a CPU of 16 bits) to decrease rolling motion during driving. However, to use such a high speed CPU in the vehicle unduly increases the manufacturing cost of the vehicle.
OBJECT AND SUMMARY OF THE INVENTION
An object of the present invention is to provide a suspension control apparatus which can achieve a high stable vehicle behavior and at the same time improved riding comfort of the vehicle when traveling on a bumpy-road without an increase in manufacturing cost.
In order to achieve the above-mentioned object, the suspension control apparatus of the present invention comprises:
a roll angular velocity sensor for detecting angular velocity about a roll axis of the vehicle,
bumpy-road driving detection means which detects bumpy-road driving of the vehicle based on output signal of the roll angular velocity sensor, and
shock absorber means whereof damping force is controlled in response to the output signal from the bumpy-road driving detection means.
In accordance with the suspension control apparatus of the present invention, a bumpy-road driving state from the vehicle is detected by output signals of the roll angular velocity sensor. Therefore, the suspension control apparatus of the present invention does not malfunction due to mud, dust or snow on the road. Additionally, the vehicle posture change can be correctly detected. Furthermore, the suspension control apparatus of the present invention does not malfunction due to abrasion of a sliding part e.g. variable resistor used for detecting stroke of the shockabsorber.
As a result, riding comfort and driving stability of the vehicle posture are improved by using the suspension control apparatus of the present invention; which is simple in construction and low in cost.
While the novel features of the invention are set forth particularly in the appended claims, the invention, both as to organization and content, will be better understood and appreciated, along with other objects and features thereof, from the following detailed description taken in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view showing the principal parts of a suspension control apparatus of the present invention in a vehicle (the vehicle illustrated by alternating long and short dash lines),
FIG. 2 is a graph of a typical output signal of the roll angular velocity sensor and accumulated time detecting bumpy-road driving of the vehicle.
FIG. 3 is a block diagram of the suspension control apparatus shown in FIG. 1.
FIG. 4 is a characteristic diagram of the holding time for controlling damping force of the suspension control apparatus shown in FIG. 1, and
FIG. 5 is a flow chart of operation of the suspension control apparatus according to the present invention.
It will be recognized that some or all of the Figures are schematic representations for purposes of illustration and do not necessarily depict the actual relative sizes or locations of the elements shown.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Hereafter, preferred embodiments of the suspension control apparatus of the present invention are elucidated with reference to the accompanying drawings of FIG. 1 to 5.
FIG. 1 is a perspective view showing a principal part of the suspension control apparatus which is disposed in a vehicle 11 shown by alternating long and short dashed lines. The suspension control apparatus comprises a vehicle speed sensor 1, a roll angular velocity sensor 2, shock absorbers 3, actuators 4 and a controller 5. The vehicle speed sensor 1, which is disposed in a front grill adjacent a speed meter, produces a signal of vehicle speed by detecting the revolution speed of an output shaft of a gearbox in the vehicle 11. The roll angular velocity sensor 2 is provided to detect an angular velocity of rotation about a longitudinal and horizontal line of the vehicle body at substantially a center of the vehicle 11, that is about a roll axis B of the vehicle 11. The directions of the rotation are shown with an arrow A in FIG. 1. The roll angular velocity sensor 2, for instance described in U.S. Pat. No. 4,671,112, which issued Jun. 9, 1987 and granted to the same assignee, is usable. The shock absorbers 3 damp the force received by wheels of the vehicle 11. For instance, the shock absorbers 3 are a hydraulic active suspension and their damping rate is controlled by controlling hydraulic values using an electromagnet. The actuators 4, which are provided on the shock absorbers 3, control the damping force of the shock absorbers 3. The controller 5, which is disposed in an appropriate space, such as under the back seat or in the trunk, produces the output signals for controlling the damping force of the shock absorbers 3. The actuators 4 operate the shock absorber 3 by receiving the output signals, which are produced by the controller 5 in response to the output signals of the vehicle speed sensor 1 and the roll angular velocity sensor 2.
FIG. 2 is a graph of a typical output signal ωp of the roll angular velocity sensor 2 when the vehicle 11 is driven on a very bumpy road, that is, when the vehicle 11 receives continuous shocks. And, FIG. 2 shows how bumpy-road driving is inferred or estimated from the output signal ωp of the roll angular velocity sensor 2. In FIG. 2, Ta which is constant time, e.g. 1.5 seconds, is a time interval for judging the state of bumpy-road driving. Bumpy-road driving is inferred at every constant time interval Ta, namely at each point ta. Ts is a time period defined by accumulating a respective time period when the absolute value |ωp| of the output signal ωp of the roll angular velocity sensor 2 reaches or exceeds the predetermined value ωBMP during each constant time interval Ta. When the accumulated time period Ts, namely bumpy-road driving time reaches or exceeds the predetermined time tBMP, it is judged that the vehicle 11 is in bumpy-road driving. And the actuators 4 are immediately driven to change the damping force of the shock absorbers 3.
That is, the bumpy-road driving state is determined by the conditions shown by the following formula (1):
Ts≧tBMP (1).
The following formulas (2) and (3) show the operating parameters of the above-mentioned predetermined value ωBMP and predetermined time tBMP which are found preferable through our experiments:
|ωp|≧5.3deg/sec (2),
and
Ts≧0.4sec (3).
FIG. 3 shows the block diagram of the suspension control apparatus of the present invention in FIG. 1.
The controller 5 provides the bumpy-road driving detection part 6 for detecting bumpy-road driving and the operation circuit 7 for driving the actuators 4. In actual example, the controller 5 is constituted substantially by an A/D converter, an arithmetic unit, such as a logical circuit having a CPU, a ROM and a RAM.
The bumpy-road driving detection part 6 detects the bumpy-road driving of the vehicle 11 by using the output signal ωp of the roll angular velocity sensor 2, as shown in FIG. 2. The bumpy-road driving detection part 6 produces an output signal to the operation circuit 7 for controlling the vehicle posture, to improve the driving stability and riding comfort.
The operation circuit 7, which receives the control signal from the bumpy-road driving detection part 6, drives the actuators 4 to change a damping rate of the shock absorbers 3. In this embodiment, the damping rate during bumpy-road driving is fixed at 0.4.
Apart from the above-mentioned embodiment wherein the shock absorbers 3 during bumpy-road driving are controlled at the predetermined constant damping rate, a modified embodiment may be such that the shock absorbers during bumpy-road driving are controlled by the damping rate in response to vehicle speed.
The damping rate is given by the following formula (4); ##EQU1## where C is the damping coefficient ##EQU2## of the shock absorbers 3 during normal straight driving of the vehicle 11, M is the sprung mass ##EQU3## and K is the spring constant (SI units: N/m) of the suspension.
FIG. 4 shows a characteristic diagram of the holding time T for retaining the damping force after completion of bumpy-road driving. Since the rolling of the vehicle 11 remains a short time after bumpy-road driving, due to inertia and suspension characteristics of the vehicle 11, the vehicle 11 needs retention of the controlled (increased) damping force of the shock absorbers 3 for the predetermined holding time T.
As shown in FIG. 4, the holding time T in which the controlled damping force is retained is set shorter as the vehicle speed becomes the higher. And, when the vehicle speed is above 80 km/h, the holding time T is set to be constant, such as at 1.0 second. This setting of the operation parameters are experimentally found preferable.
Apart from the above-mentioned embodiment wherein the holding time T is decided in response to the vehicle speed, a modified embodiment may be such that the holding time T is set up constant, or alternatively is set up so as to respond to the displacement length (distance) of the vehicle 11 after completion of bumpy-road driving. On the contrary to the above-mentioned embodiments, in some kinds of vehicles, such as a coach or a large truck, the holding time T may be set up to become larger as the vehicle speed increases.
FIG. 5 shows a flow chart of operation of the controller 5 of the suspension control apparatus of the present invention.
In step 101 of FIG. 5, the output signal V from the vehicle speed sensor 1 and the output signal ωp from the roll angular velocity sensor 2 are detected. Next, in step 102, it is judged whether the vehicle 11 is in bumpy-road driving or not. In other words, when the aforementioned accumulated time period Ts, bumpy-road driving time, reaches or exceeds the predetermined time tBMP at the judging time ta, it is judged that the vehicle 11 is driving on bumpy road.
When the controller 5 decides "YES" in step 102, the suspension control apparatus operates to increase the damping force of the shock absorbers 3 in step 103 in order to enlarge the road contact area of the tires and to improve riding comfort. As a result, the driving stability of the vehicle 11 is assured even if the vehicle 11 is driven on a bumpy-road.
When the controller 5 in step 102 decides "NO", which designates that the vehicle 11 is not driving on a bumpy road, the controller 5 judges whether the shock absorbers 3 have been controlled or not in step 104. When the controller 5 in step 104 decides "YES", which designates that bumpy-road driving has finished, a suitable holding time T (which is the time wherein the damping force is controlled (increased) after bumpy-road driving) is determined in response to the output signal V from the vehicle speed sensor 1 in step 105. The holding time T has been aforementioned in reference to the waveform shown in FIG. 4. And, in step 106, the controlled damping force of the shock absorbers 3 is kept for the holding time T after bumpy-road driving has been finished.
After completion of the damping force holding operation of the shock absorbers 3, for the holding time T, the shock absorbers 3 return to normal damping force which lasts until the suspension control apparatus detects the next bumpy-road driving state.
On the contrary, in step 104, when the controller 5 judges that the shock absorbers 3 have not yet been controlled to increase the damping force for bumpy-road driving, the shock absorbers 3 are kept at a normal damping force continuously.
The afore-mentioned problems of malfunctioning ultrasonic sensors due to mud or snow, or malfunctions due to abrasion in variable resistors in the conventional suspension control apparatus are solved. The suspension control apparatus of the present invention detects bumpy-road driving by using only two signals, namely, the output signal V of the vehicle speed sensor 1 and the output signal ωp of the roll angular velocity sensor 2.
And, in the suspension control apparatus of the present invention, the time required for computing by the controller 5 is short. The controller 5 carries out a simple computing operation by using the output signals of the vehicle speed sensor and the only one angular velocity sensor. For example, in case of using a CPU of 8 bits as the arithmetic unit, the operation times for computation of a control signal, namely the time period between reception of detection signals into the arithmetic unit and issuance of output signal to the actuators 4 takes about only 5 msec. Accordingly, the suspension control apparatus of the present invention can timely and effectively control the damping force to increase in response to a rotation around the roll axis B of the vehicle 11 when the vehicle 11 is driven on a bumpy road.
Furthermore, driving stability and riding comfort are assured by the elimination of rolling of the vehicle 11 after completion of bumpy-road driving, since the suspension control apparatus of the present invention maintains for a short time the bumpy road driving damping force of the shock absorbers 3 after bumpy-road driving is completed.
Although the present invention has been described in terms of the presently preferred embodiments, it is to understood that such disclosure is not to be interpreted as limiting. Various alterations and modifications will no doubt become apparent to those skilled in the art after having read the above disclosure. Accordingly, it is intended that the appended claims be interpreted as covering all alterations and modifications which fall within the true spirit and scope of the invention. | A suspension control apparatus for a vehicle having at least one shock absorber with a controllable damping force. The suspension control apparatus includes a roll angular velocity sensor for detecting angular velocity about a roll axis of the vehicle, and control means for determining a bumpy-road driving state of the vehicle when an accumulation time exceeds a predetermined accumulation time. The control means adjusts the damping force of the shock absorber during the bumpy road driving state. The accumulation time represents the amount of time the angular velocity exceeds a predetermined angular velocity range during a first predetermined time period. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an audio compression system, and more particularly, to an audio compression method using wavelet packet transform (WPT) in MPEG1 layer 3 (hereinafter referred to as “MP3”) and a system thereof. The present application is based on Korean Patent Application No. 2002-8305, which is incorporated herein by reference.
2. Description of the Related Art
Generally, in an MPEG standard method, monaural audio is encoded at the rate of 128 kbps, while a layered algorithm is used to encode stereo audio at the rates of 192 kbps, 92 kbps, and 64 kbps. In the layers, layer 3 is known as an MP3 technology. The MP3 technology increases the resolution of a frequency domain by adding a modified DCT (MDCT) operation, and, by considering input characteristics in the MCDT operation, adjusts the size of a window so that pre-echo and aliasing are compensated for.
FIG. 1 is a flowchart showing a conventional audio compression method using MP3 technology.
First, pulse code modulation (PCM)-type audio data is input in step 110 .
Then, PCM audio data is divided into 576 samples in each granule.
By applying a psychoacoustic model defined in the MPEG1 layer 3 to the samples, perceptual energy is obtained in step 120 .
Next, the perceptual energy obtained from the psychoacoustic model is compared with a threshold, and according to the comparison result, MDCT is performed with switching windows in step 130 . Here, a part of the MDCT window or the entire MDCT window may be switched according to the threshold. That is, as shown in FIG. 2 , if the level of the perceptual energy is higher than the threshold, this corresponds to an attack state signal, whose energy level rapidly increases, and therefore a short window is selected. If the level of the perceptual energy is lower than the threshold, this corresponds to a constant state signal, and therefore a long window is selected. Accordingly, audio samples in the respective selected window scopes are MCDT-processed and converted into data in frequency domains. At this time, a start window or a stop window is used to switch from the long window to the short window.
Also, in the MPEG1 layer 3, the types of windowing are disclosed as a long window, a start window, a short window, and a stop window, as shown in FIG. 3 . Also, as shown in FIG. 2 , the windows overlap each other in order to prevent aliasing.
Then, data on the frequency domain for which MDCT is performed are quantized according to the number of assigned bits in step 140 .
The quantized data is formed as a bit stream based on a Huffman coding method in step 150 .
Therefore, as shown in FIG. 1 , the prior art audio signal compression method uses the MDCT window switching method to compress a non-stationary signal which causes a pre-echo effect. However, the prior art audio compression method using the MDCT as shown in FIG. 1 degrades sound quality of low bit rates, less than, for example, 128 kbps (64 kbps, stereo), due to the limit of the MDCT base.
SUMMARY OF THE INVENTION
To solve the above problems, it is an objective of the present invention to provide an audio compression method and apparatus in which audio data is compressed adaptively using the MDCT and WPT so that a non-stationary signal can be effectively compressed and at the same time an audio signal can be effectively compressed even in a low bit rate.
According to an aspect of the present invention, there is provided an audio compression method comprising calculating perceptual energy by analyzing audio samples which are input based on a psychoacoustic model; according to comparison of the level of the calculated perceptual energy with a threshold, selectively determining a modified DCT (MDCT) processing window and a wavelet packet transform (WPT) processing window; by processing audio samples corresponding to the scopes of the determined windows in the MDCT and WPT, converting the audio samples into data on frequency domains; and quantizing the processed data on the frequency domains according to the number of assigned bits.
According to another aspect of the present invention, there is provided an audio compression apparatus comprising a filter bank unit which divides the bands of audio samples being input, by a polyphase bank; a psychoacoustic model analyzing unit which analyzes perceptual energy from the input audio samples based on a psychoacoustic model; a TS selecting unit which selects one of MDCT and WPT windows by comparing the perceptual energy analyzed in the psychoacoustic model with a predetermined threshold; and a TS processing unit which performs MDCT and WPT for the samples whose bands are divided in the filter bank unit, according to the MDCT and WPT windows selected in the TS selecting unit.
BRIEF DESCRIPTION OF THE DRAWINGS
The above objects and advantages of the present invention will become more apparent by describing in detail preferred embodiments thereof with reference to the attached drawings in which:
FIG. 1 is a flowchart showing a conventional audio compression method using the MP3 standard;
FIG. 2 is a schematic diagram showing prior art MDCT processing steps in a frequency domain;
FIG. 3 shows the types of prior art windows;
FIG. 4 is a block diagram of an audio signal compression system according to the present invention;
FIG. 5 is a flowchart showing an audio signal compression method according to the present invention;
FIG. 6 shows the types of MDCT and WPT windows according to the present invention;
FIG. 7 is a state diagram of window switching in the MDCT and WPT; and
FIG. 8 is a diagram of the structure of a WPT tree processed in a frequency domain according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The audio signal compression system according to the present invention of FIG. 4 comprises a filter bank unit 410 , an acoustic psychological model unit 420 , a TS selecting unit 430 , a TS processing unit 440 , a quantizing unit 450 , and a bit stream generating unit 460 .
First, the wavelet packet transform (WPT) used in the present invention is a kind of sub-band filtering, in which a signal is broken down into multiple levels on a wavelet basis and if the number of levels increases, resolution for a frequency increases. Also, the signal characteristics of an attack part make the analysis of the wavelet basis easier.
Referring to FIG. 4 , the filter bank unit 410 divides PCM audio samples that are input in units of granules, into 32 bands by using a polyphase bank.
Using a psychoacoustic model, the acoustic psychological model unit 420 obtains perceptual energy. In the human acoustic characteristics, there is a mask effect in which a frequency component having a higher level masks neighboring frequencies having a lower level. Accordingly, using this human acoustic characteristic, the level of energy that can be perceived is obtained.
The TS selecting unit 430 compares the perceptual energy obtained by the psychoacoustic model with a threshold to generate a control signal for selecting an MDCT window or a WPT window. That is, if the level of the perceptual energy is higher than the threshold, this corresponds to an attack state signal whose energy level rapidly increases and the TS selecting unit 430 selects a WPT window, while if the level of the perceptual energy is lower than the threshold, this corresponds to a steady state signal whose energy level is constant and the TS selecting unit 430 selects an MDCT window.
For the samples whose bands are divided in the filter bank unit 410 , the TS processing unit 440 selectively processes the MDCT processing window and the WPT processing window according to the control signal output from the TS selecting unit 430 , and performs MDCT processing and WPT processing for the samples corresponding the selected respective window scopes.
The quantizing unit 450 quantizes audio data on the frequency domain, which are TS processed in the TS processing unit 440 , according to the number of assigned bits.
The bit stream generating unit 460 forms audio data quantized in the quantizing unit 450 as a bit stream.
FIG. 5 is a flowchart showing an audio signal compression method according to the present invention.
First, the PCM audio data, which are input after being divided into 576 samples for each granule, are divided into 32 bands through a filter bank in step 510 .
Then, the psychoacoustic model is applied to the divided samples so that perceptual energy is obtained in step 520 .
Next, in order to determine one of the MDCT processing window and the WPT processing window, the perceptual energy obtained in the psychoacoustic model is compared with the threshold in step 530 . Here, using the fact that the wavelet characteristic is similar to the attack state signal, the WPT window is applied to the attack state signal.
Then, if the level of the perceptual energy is higher than the threshold, this corresponds to the attack state signal whose energy level rapidly increases and the WPT window is selected in step 526 , and if the level of the perceptual energy is lower than the threshold, this corresponds to the steady state signal whose energy level is constant and the MDCT window is selected in step 524 .
Next, data corresponding to each of the selected windows are MDCT or WPT are processed and converted into audio data on frequency domains in steps 540 and 550 , respectively. At this time, the WPT analyzes the samples of the frequency domain of the attack part hierarchically through a wavelet filter.
Then, data on the frequency domain for which MDCT is performed are quantized according to the number of assigned bits in step 560 .
Using the Huffman coding, the quantized data are formed as a bit stream in step 570 .
FIG. 6 shows the types of MDCT and WPT windows according to the present invention.
Referring to FIG. 6 , the long window, the start window, and the stop window perform MDCT, and the WPT window (wavelet packet window) performs WPT. The MDCT windows and the WPT window are formed in shapes satisfying perfect reconstruction (PR) conditions. The PR conditions enable reconstruction such that frequency domain data in encoding are the same as the frequency domain data in decoding. At this time, the long window has a length of 36 samples and is used for the steady state signal. The start window has a length of 28 samples, and is used for a part where the steady signal or the attack signal begins. The WPT window having a length of 18 samples is a combined type of the MDCT start window and stop window and is used for the attack state signal. The stop window has the length of 28 samples and is used for a part where the attack state signal or the steady state signal ends.
FIG. 7 is a state diagram of window switching in the MDCT and WPT.
First, in a part where the level of energy is lower than the threshold, the long window state is maintained. If the attack signal begins, this means a state where a part of a signal in which the energy level is higher than the threshold begins and accordingly the state of the long window is transited to the start window state. Then, the start window state is transited to the wavelet packet window state for processing the attack signal. Then, the wavelet packet window is maintained as the original state in a part where the energy level is higher than the threshold. At this time, if the steady signal begins, this means a state where a part of a signal in which the energy level is lower than the threshold begins and accordingly the state of the wavelet packet window is transited to the stop window state (referred to as NO ATTACK in FIG. 7 ). Then, the stop window state is transited to the long window state for processing the steady signal (referred to as NO ATTACK in FIG. 7 ).
FIG. 8 is a diagram of the structure of a WPT tree processed in a frequency domain according to the present invention.
First, the samples on the frequency domains are divided into samples of a low frequency area (L) and samples of a high frequency area (H) through an 18 coefficient WPT filter 810 .
Then, the samples of the low frequency area (L) filtered in the 18 coefficient WPT filter 810 are divided into samples of a low frequency area (L) and samples of a high frequency area (H) through an 8 coefficient WPT filter 820 , while the samples of the high frequency area (H) filtered in the 18 coefficient WPT filter 810 are divided into samples of a low frequency area (L) and samples of a high frequency area (H) through a 10 coefficient WPT filter 830 .
Then, the samples of the low frequency area (L) filtered in the 8 coefficient WPT filter 820 are divided into samples of a low frequency area (L) and samples of a high frequency area (H) through a 4 coefficient WPT filter 840 , while the samples of the high frequency area (H) filtered in the 8 coefficient WPT filter 820 are divided into samples of a low frequency area (L) and samples of a high frequency area (H) through a 4 coefficient WPT filter 850 . The samples of the low frequency area (L) filtered in the 10 coefficient WPT filter 830 are divided into samples of a low frequency area (L) and samples of a high frequency area (H) through a 4 coefficient WPT filter 860 . The samples of the high frequency area (H) filtered in the 10 coefficient WPT filter 830 are divided into samples of a low frequency are (L) and samples of a high frequency area (H) through a 6 coefficient WPT filter 870 .
Then, the samples of the high frequency area (H) and low frequency area (L) filtered in the 4 coefficient WPT filters 840 through 860 and the 6 coefficient WPT filter 870 are divided into a plurality of bands. Samples of bands which are finally divided more finely are used in WPT processing.
As described above, the present invention compresses an audio signal by selectively switching the MDCT window and the WPT window even at a low bit rate such that a non-stationary signal is effectively processed. Also, even at a low bit rate, the MDCT which enables finer analysis of audio data is applied such that compact disc quality can also be maintained in the low bit rate. In addition, the present invention uses the WPT window having a characteristic similar to that of the attack state signal such that pre-echo can be effectively prevented. | An audio compression method using wavelet packet transform (WPT) in MPEG1 layer 3 (hereinafter referred to as “MP3”) and a system thereof are provided. The method comprises calculating perceptual energy by analyzing audio samples which are input based on a psychoacoustic model; according to comparison of the level of the calculated perceptual energy with a threshold, selectively determining a modified DCT (MDCT) processing window and a wavelet packet transform (WPT) processing window; by processing audio samples corresponding to the scopes of the determined windows in the MDCT and WPT, converting the audio samples into data on frequency domains; and quantizing the processed data on the frequency domains according to the number of assigned bits. | 6 |
TECHNICAL FIELD OF THE INVENTION
The present invention relates to the vaporization of cryogenic liquids by passing said cryogenic liquid through a vaporizer in heat exchange with ambient air. More particularly, it relates to the vaporizer design and the path of flow of the cryogenic fluid through the vaporizer.
BACKGROUND OF THE INVENTION
Ambient-air vaporizers are used to vaporize cryogenic liquids before being piped to downstream operations or being released to the surrounding atmosphere. Such vaporizers are typically of the Starfin-type and have longitudinally finned pipe lengths arranged in a 3×4 rectangular array. A side view of such a vaporizer is shown in FIG. 1 labeled prior art, and a top view is shown in FIG. 2, also labeled prior art.
The liquid to be vaporized enters the fin section Labeled 1 and is passed through the fin pipings in numerical order as depicted in FIG. 2 until it exits from fin pipe 12. The liquid enters the bottom of the first finned pipe, passes through, exits the top and subsequently enters the top of the next pipe where it flows to the bottom, exits, and enters the bottom of the next pipe, etc.
If gas delivery temperature from the vaporizer falls below a preset value, a low temperature shut off valve closes to prevent liquid carry-over to the customer or embrittlement of downstream piping caused by extreme cold temperatures. For example, if carbon-steel piping is used to transport the gas downstream of the vaporizer, a shut off temperature of about -23° C. is employed to prevent embrittlement of the piping. In extremely cold weather conditions and/or high product flow, the vaporizers can develop ice formations and freeze-over between the fins occurs. When such a freeze-over occurs, the capacity of the vaporizer decreases, and can thereby cause the gas delivery temperature to fall below such a preset value. This decrease in capacity is due in part to reduced convective heat transfer and ice bridging between fin pipings which allows conduction between warmer fins and colder fins. When such a decrease in capacity occurs it is necessary to physically chop away the ice which is formed between the fin pipings of the vaporizer in order to get the system back on-stream following a shutdown.
Solutions to the problem of reduced capacity due to reduced heat transfer and ice bridging between the fins have included installing low temperature-ductile metal systems downstream which tolerate lower delivery gas temperatures or installing heated vaporizers which use steam or electric heat to vaporize the cryogenic liquid. Additionally, it has been suggested to increase the number of ambient vaporizers in series or parallel connected pairs, thereby enlarging the vaporizing system itself. All of the above solutions require a considerable increase in equipment and process cost.
BRIEF SUMMARY OF THE INVENTION
The present invention provides for an improved ambient-air liquid cryogen vaporizer and a process for using the same. The invention comprises a new piping arrangement for a typical ambient-air vaporizer having at least twelve vertically disposed pipe lengths arranged in a 3×4 rectangular array with adjacent pipe lengths being approximately equally spaced from one another.
This new piping arrangement is designed such that warmer downstream pipe lengths are placed at more remote locations from colder upstream pipe lengths, thereby reducing ice-bridging with the warmer fins. Consequently, the heat transfer capacity of the vaporizer is increased resulting in a more efficient vaporization process and reducing shutdown time due to cold gas delivery temperatures.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partial cut-away side view of a typical prior art vaporizer arrangement.
FIG. 2 is a top view of the prior art vaporizer depicted in FIG. 1.
FIG. 3 is a top view of the vaporizer arrangement of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Ambient-air vaporizers are commonly used to vaporize cryogenic liquids prior to releasing the fluid to the atmosphere or piping to a downstream operation. A typical vaporizer set-up is shown in FIG. 1. A storage vessel or tank 20 containing a cryogenic liquid is connected by a transport pipe 24 to a vaporizer unit 26. A valve 22 is used to regulate the flow of cryogenic liquid to the vaporizer 26. The cryogenic liquid is vaporized in the vaporizer 26 and is subsequently withdrawn through line 34.
A typical ambient-air vaporizer as shown in FIG. 1 has at least 12 vertically disposed pipe lengths 28 having longitudinally placed heat exchange surfaces or starfins 30 with adjacent pipe lengths being approximately equally spaced from one another in a generally rectangular array. One side of the rectangular array has four pipe lengths and the adjacent side has three pipe lengths. The vertical pipe lengths are interconnected alternately top to top and bottom to bottom via "U" shaped connecting pipes 32.
The cryogenic fluid enters and passes through a first pipe length 28 and is subsequently withdrawn and passed through the "U" shaped connecting pipe or conduit 32 into a second vertical pipe length 28. The cryogenic fluid is vaporized at some point in the vaporizer, this point depending upon conditions such as temperature and flow rate. The cryogenic fluid leaving the vaporizer is preferably all vapor and can be vented to the atmosphere if desired.
Typical starfin ambient-air vaporizers are manufactured as standard units with sequential series piping as shown in FIG. 2. In this type of prior art set-up the cryogenic fluid to be vaporized is passed through the 12 pipe lengths in sequential order beginning with the pipe length labeled 1. The cryogenic fluid to be vaporized is passed through each vertical pipe length in numerical order via said "U" shaped connecting pipes or conduits 32.
Operating an ambient-air vaporizer having the prior art pipe placement geometry and interconnection scheme as shown in FIG. 2, often results in ice accumulation on the upstream heating tubes which can extend to obstruct air flow over adjacent tubes which are substantially further downstream in the array and thereby detract from the heat transfer in the warm zone. For example, even in warm whether, a large solid ice block can form between pipes 1, 2, 7 and 8, as depicted by the broken circle 15 in FIG. 2. This ice block represents a thermal short-circuit between the coldest pipe length #1 and pipe length #8 which is two-thirds of the way through the vaporizer. During periods of high flow and/or cold weather, the ice build-up may extend to pipe lengths 9 and 10.
The present invention provides an ambient-air vaporizer piping geometry which lessens the effect of ice build-up on reducing heat transfer in the vaporizer. In this new arrangement, any ice which forms between fins provides conductive paths between fins of more nearly equivalent temperature than in existing designs. As a result, there is less conductive heat transfer and less compromise of vaporizer performance.
The present improved vaporizer configuration and method of using the same can be best understood by reference to FIG. 3. This figure is a top view of an ambient-air vaporizer having 12 vertically disposed pipe lengths with adjacent pipe lengths being approximately equally spaced from one another and being arranged in a 3×4 rectangular array. The 12 pipe lengths have longitudinally placed heat exchange surfaces or starfins.
A cryogenic fluid, partially or completely in the liquid phase, enters a fluid inlet at one end of vertical pipe length 101 via transport pipe 124. The cryogenic fluid passes through pipe length 101 and exits a fluid outlet at the opposite end of the pipe length. The cryogenic fluid then enters a fluid inlet at one end of vertical pipe length 102 located next to the first pipe length 101 via a "U" shaped connecting pipe or conduit 132. All the vertical pipe lengths have fluid inlets and outlets with the fluid inlets being connected via "U" shaped connecting pipes or conduits to the fluid outlets to the preceding vertical pipe lengths. The cryogenic fluid flows through pipe length 102 and exits a fluid outlet at the opposite end of the pipe length. The cryogenic fluid enters a fluid inlet at one end of vertical pipe length 103 located diagonal to the second pipe length 102 and next to the first pipe length 101. The cryogenic fluid passes through vertical pipe length 103 and subsequently is introduced to, and passes through, a fourth vertical pipe length 104 located at a corner of the rectangular array and next to the third pipe length 103. The fluid is removed from the fourth pipe length 104 and passed through a fifth vertical pipe length 105 located diagonal to the fourth pipe length 104 and beside both the second 102 and third 103 pipe lengths. The fluid is then removed from the fifth pipe length 105 and passed through a sixth vertical pipe length 106 located diagonal to the fifth pipe length 105 and beside the second pipe length 102. The fluid is then removed from the sixth vertical pipe length 106 and passed through a seventh vertical pipe length 107 located at a corner of the rectangle and beside said sixth pipe length 106. The fluid is subsequently removed from the seventh pipe length 107 and passed through an eighth vertical pipe length 108 located diagonal to the seventh vertical pipe length 107 and beside said fifth 105 and sixth 106 pipe lengths. The fluid is then removed from the eighth vertical pipe length 108 and passed through a ninth vertical pipe length 109 located diagonal to the eighth pipe length 108 and beside said fourth 104 and fifth 105 pipe lengths. The fluid is removed from the ninth vertical pipe length 109 and passed through a tenth vertical pipe length 110 located beside the eighth pipe length 108 and ninth pipe length 109. Further, the fluid is removed from the tenth vertical pipe length 110 and passed to an eleventh vertical pipe length 111 located diagonal to the tenth pipe length 110 and beside the seventh 107 and eighth 108 pipe lengths. Finally, the fluid is removed from the eleventh vertical pipe length 111 and passed through a twelfth vertical pipe length 112 located at the remaining corner of the rectangle and beside the tenth 110 and eleventh 111 pipe lengths. After passing through the twelfth vertical pipe length 112 the fluid is at least partially, and preferably totally, vaporized and is subsequently withdrawn via exit pipe 134.
While the above description illustrates a vaporization process in accordance with FIG. 3 wherein the cryogenic fluid is passed through the pipe lengths of the vaporizer in numerical order starting with pipe length 101 and ending with pipe length 112, the flow of the fluid through the vaporizer could easily be reversed; i.e. the fluid entering the pipe length 112, proceeding through the pipe lengths in numerical order and exiting pipe length 101.
The present process and apparatus can be used to treat any cryogenic fluid which is typically partially or completely in the liquid state and which normally exists as a vapor under ambient conditions. Examples of such cryogenic fluids are liquid oxygen, liquid nitrogen, and liquid argon. The present apparatus can also be employed as a heat exchange device for any gas or liquid having a temperature different from that of the surrounding air.
As can be seen in FIG. 3, a same size ice block, as depicted by broken circle 115, as that in FIG. 2, only establishes bridging between pipe lengths 101, 102, 103, and 105, which are much colder than pipe lengths 7 and 8 in FIG. 2. In other words, in the prior art technology the inlet pipe length 1 might heat exchange against a fin of a pipe length 67% of the way through the vaporizer; i.e. pipe length 8 in FIG. 2; whereas in the present invention the inlet pipe length 101 will heat exchange a fin only 25% of the way through the exchanger, i.e. pipe length 103.
This improved configuration of vaporizer piping allows for a more efficient heat exchange to occur within the vaporizer resulting in less shutdown time due to freeze over and cold outlet fluid temperatures. If the cryogenic fluid exiting the last pipe length in the vaporizer is not completely vaporized, or is too cold for subsequent use, additional vaporizer units may be added in series or in parallel.
Having thus described the present invention, what is now deemed appropriate for Letters Patent is set out in the following appended claims. | The present invention is an improved ambient-air liquid cryogen vaporizer and a method of using the same. The interconnections between the vertical starfinned pipe lengths of the vaporizer are arranged such that the coldest temperature pipe lengths are placed at more remote locations from the warmer pipe lengths than in previous vaporizer set-ups. This arrangement increases the capacity of the vaporizer by reducing ice bridging between the colder and warmer fins. | 5 |
FIELD OF THE INVENTION
[0001] The invention relates to technologies in the field of semiconductor photodetectors.
BACKGROUND OF THE INVENTION
[0002] Semiconductor photodetectors that use the “avalanche effect” for signal amplification have areas of high electrical field strength in a near-surface region of the semiconductor substrate, and these areas help to multiply charge carriers that are generated by radiation absorption in the semiconductor substrate. The areas of high electrical field strength are created for example by forming doping zones that have been doped according to different doping types and are assigned to each other within the semiconductor substrate of the photodetector.
[0003] In order to detect extremely small quantities of radiation, down to the level of single photons, such semiconductor photodetectors are operated with a bias voltage higher than the voltage that causes permanent breakdown of the component structures. When the semiconductor photodetector is operated, after a certain time thermally generated charge carriers or charge carriers generated by radiation absorption penetrate the area of high electrical field strength and are multiplied there by “avalanche breakdown”, which causes a high current between the electrical connectors or contacts of the semiconductor photodetector. If the voltage at the electrical contacts of the photodetector is not lowered and if internal serial resistances within the semiconductor photodetector do not bring about a reduction in the high field strength, the breakdown becomes permanent, since new charge carriers are created constantly in the resulting charge carrier avalanche.
[0004] However, if a serial resistance is interposed between the operating voltage and the contacts of the semiconductor photodetector, the field strength in the area of high electrical field strength may be reduced by the current pulse and the associated voltage drop in such manner that permanent avalanche multiplication can no longer be sustained. Consequently, the current falls and the high field strength in the area of high field strength is established again. Such a serial resistance is also referred to as a quench resistance.
[0005] All of the processes described are time-dependent. For semiconductor photodetectors with a relatively large detector array, switching times or recovery times between the triggering of a charge carrier avalanche and quenching of the avalanche, that is to say the time before a single incident can be registered again, is very long. It was therefore suggested to divide the active surface of the semiconductor photodetector in a large number of individual pixel elements and to assign a quench resistance to each pixel element (see for example Sadygov Z.: “Three advanced designs of micro-pixel avalanche photodiodes: Their present status, maximum possibilities and limitations”, Nuclear Instruments and Methods in Physics Research A 567 (2006)70-73). In a structural variant of known avalanche photodiodes, the quench resistance is partially in the area of the radiation penetration window. This causes disadvantages with regard to the usable detector area, since this is limited by resistance layers and metal contacts.
[0006] It was suggested in document DE 10 2007 037 020 B3 to form the quench resistance in the semiconductor substrate of the photodetector, between the area of high field strength and a contact layer on the back side. The quench resistance is thus located deep inside the semiconductor substrate. However, this construction has the disadvantage that highly specific requirements are imposed on the design of the semiconductor substrate, and particular dependence on material parameters and structure sizes of the pixel elements arises.
[0007] Document DE 10 2007 037 020 B3 discloses an avalanche photodiode for detecting radiation.
[0008] A single photon avalanche photodiode is described in the document WO 2008/011617.
BRIEF SUMMARY
[0009] The object of the invention is to describe new technologies for semiconductor photodetectors that enable both optimised usage of the active detector array and a photodetector structure that may be produced and configured as simply as possible. In particular, it aims to reduce the dependency of the semiconductor photodetector on special material parameters and structure properties.
[0010] This object is solved according to the invention by a semiconductor photodetector as described in independent claim 1 and a radiation detector system as described in independent claim 11 . Advantageous variations of the invention constitute the object of the dependent subordinate claims.
BRIEF DESCRIPTION OF THE FIGURES
[0011] In the following, the invention will be explained in greater detail on the basis of preferred embodiments thereof and with reference to the figures. The figures show:
[0012] FIG. 1 a schematic view of a cross-section through a portion of a known se conductor photoconductor,
[0013] FIG. 2 a schematic view of a cross-section through a portion of a semiconductor photoconductor with additional doping zones,
[0014] FIG. 3 a schematic view of a cross-section through a portion of a known semiconductor photoconductor with additional doping zones, wherein a second additional doping zone is formed discontinuously,
[0015] FIG. 4 a schematic view of a portion of the semiconductor photoconductor of FIG. 3 , wherein a contact connection is formed for one of the additional doping zones,
[0016] FIG. 5 a schematic view of a cross-section through a portion of a semiconductor photoconductor with additional doping zones, wherein the contact connection for the additional doping zone of FIG. 4 is realised according to modified design,
[0017] FIG. 6 a schematic view of a cross-section through a portion of a semiconductor photoconductor with additional doping zones, wherein a further contact connection is realised for a lower doping zone of the avalanche area,
[0018] FIG. 7 a schematic view of a cross-section through a portion of a semiconductor photoconductor in which a control circuit is coupled between a lower doping zone of the avalanche area and an additional doping zone, and
[0019] FIG. 8 a schematic view of a portion of a detector service of a semiconductor photodetector.
DETAILED DESCRIPTION
[0020] The invention encompasses the idea of a semiconductor photodetector comprising:
a semiconductor substrate, an upper doping zone, which is doped according to a first doping type and extends laterally on an upper side in the semiconductor substrate, a lower doping zone, which is doped according to a second doping type and is assigned to the upper doping zone so as to form avalanche areas in such manner that the lower doping zone extends laterally in the semiconductor substrate and facing the upper diode doping zone, and is constructed discontinuously by the formation of at least one intermediate area, a quench resistance area, which is formed in the semiconductor substrate between the lower doping zone and a contact layer that is formed on the back of the semiconductor substrate, a first additional doping zone, which is doped according to the first doping type, located in an area in the semiconductor substrate between the lower doping zone and the contact layer and extends laterally below the at least one intermediate area and into the area below the lower doping zone, and is discontinuous below the lower doping zone, and a second additional doping zone, which is doped according to the second doping type, located in the area between the lower doping zone and the first additional doping zone in the semiconductor substrate, extends laterally below the at least one intermediate area and forms a potential barrier between the upper doping zone and the first additional doping zone.
[0027] The invention further provides a radiation detector system having the following features: a semiconductor photodetector of the aforementioned type in which at least one contact connection assigned to the first additional doping zone is formed, and a control circuit that is coupled to the at least one contact connection and configured to provide a control signal for a control potential that is to be applied to the first additional doping zone.
[0028] According to the invention, a first and a second doping zone, each doped according to different doping types, are provided below the avalanche areas in the semiconductor photodetector. The first additional doping zone is preferably never impoverished with regard to charge carriers and is located lower in the semiconductor substrate, which substrate itself is doped according to the second doping type. In this way, the first additional doping zone may be used to in this respect as a subgate electrode, so that the first additional doping zone may also be referred to as a subgate doping zone.
[0029] The second additional doping zone serves to form a potential barrier between the upper doping zone of the avalanche area and the first additional doping zone. This decoupling makes it possible for the quench resistance to be adjusted independently and individually by applying a corresponding control potential to the first additional doping zone (subgate doping zone).
[0030] In quite general terms, the avalanche areas and the non-active areas located between them together form a contiguous detector array of the semiconductor photodetector. To this extent, the avalanche areas form “pixel elements” of the detector array. One or more lower doping zones may be assigned to such a pixel element. The first additional doping zones located below the detector array form a network of “subgate electrodes”.
[0031] The structural configuration of the semiconductor photodetector with the additional doping zones renders operation of the detector more independent of production-related material and structural constraints such as layer thickness, doping concentrations, layout tolerances or other parameter variations. Even fluctuating temperature effects may be compensated in this way. Different potentials may be applied to the upper doping zone of the avalanche area and the first additional doping zone, although both doping zones are doped according to the same doping type. This makes it possible to set the avalanche operating point and the quench resistance necessary to quench the charge avalanche separately.
[0032] With the invention it becomes possible to drive even relatively small detector structures appropriately for their function, so that the yield of functioning detector structures on wafer is increased. Large and very expansive functioning structures are only even possible because of this. By making larger area components usable, it becomes possible to integrate arrays with an upper doping zone having an intermittent design.
[0033] A preferred embodiment of the invention provides that the second additional doping zone extends laterally at least over the entire width of the at least one intermediate area. When the semiconductor photodetector is viewed from above, the second additional doping zone in this embodiment extends over the entire surface of the at least one intermediate area, which is formed in the lateral direction between the sections of the lower doping zone. At the same time, the second additional doping zone may optionally extend into the area below the lower doping zone. Such a design of the second additional doping zones may be created using masked doping zone production methods.
[0034] In an advantageous embodiment of the invention, it may be provided that the second additional doping zone has the form of a continuous doping zone that is impoverished in the at least one intermediate area. In this variation, it is possible to produce the continuous doping for the first additional doping zone in a maskless production process. Accordingly, the use of masks during doping may be dispensed with.
[0035] An advantageous embodiment of the invention provides a contact connection for the first additional doping zone, via which a control circuit may be connected to the first additional doping zone. In a refinement thereof, a plurality of such contact connections are formed, each being assigned to one or more first additional doping zones. Through the optional connection of the control circuit to the one or more contact connections, which are assigned to the one or more first doping zone, a control potential may be applied to the first additional doping zone, which is formed lower in the semiconductor substrate than the second additional doping zone, and in accordance with the preceding notes may also be referred to as a subgate doping zone. If multiple contact connections are provided, these may be charged with different potentials. In this way, in a variation it also becomes possible for different potentials for different potentials to be applied to multiple first additional doping zones that are assigned to a common pixel element. In an advantageous design, multiple separate contact connections are produced for the first additional doping zones at the edge of the detector array conned by the array of pixel elements, that is to say still inside and/or already outside the detector array. However, contact connections may also be provided solely or additionally in areas of the detector array away from the edges thereof. In this way, it is possible to correct systematic errors during operation in any direction over the detector array by applying potentials that compensate for the errors to contact connections that are assigned to each other. The assignment between contact connections by charging with corresponding potential may be carried out for example for adjacent and/or opposing contact connections. In this way, it becomes possible to correct systematic errors for any desired section or region of the detector array. At the same time, it may be provided that multiple sides of the pixel element array, for example opposite sides, are formed with separate contact connections that are assigned to the first additional doping zones. It thus becomes possible to control the first additional doping zone(s) independently due to the potential barrier formed by the second additional doping zone between the upper doping zone, which is assigned to the avalanche area, and the first additional doping zone. In this respect, the invention also relates to a method for operating the semiconductor photodetector, in which potentials for correcting systematic errors are applied to contact connections that are assigned to the first additional doping zones.
[0036] A preferred embodiment of the invention provides that the contact connection is formed with an external contact and overlapping conductive doping zones, which are doped in accordance with the first doping type. The overlapping conductive doping zones are preferably created for example with the aid of a mesa structure or V-groove etching with subsequent doping of the surface. But the use of technologies in conjunction with areas of suitable width that have been filled in with doped polysilicon may also be provided. In this context, it is sufficient to provide only one contact connection for the first additional doping zone, since this extends in a plane in the semiconductor substrate, although it is also discontinuous opposite the avalanche areas.
[0037] In an advantageous embodiment of the invention, it may be provided that the contact connection is formed outside a detector array. The contact connection is preferably formed on the edge of the detector array, that is to say adjacent to the surface belonging to the avalanche areas that define the pixel elements and the areas formed between them.
[0038] A preferred embodiment of the invention provides a contact connection assigned to the lower doping zone, via which a control circuit may be connected to the lower doping zone. In a refinement thereof, a plurality of such additional contact connections is formed, each of which is assigned to one or more lower doping zones. The control circuit that may be coupled to the additional contact connection is preferably designed such that it is able to measure the quench resistance for the quench resistance area. If the control circuit designed in this way is combined with the circuit for applying the control potential to the first additional doping zone via the contact connection, a means for adjusting the control potential is created in such manner that it may be set and adjusted depending on the measured quench resistance.
[0039] A preferred embodiment of the invention provides that the additional contact connection is formed with a further external contact and a doping zone that is doped in accordance with the second doping type. The explanatory notes provided with regard to the associated design of the contact connection apply correspondingly.
[0040] In an advantageous embodiment of the invention, it may be provided that the additional contact connection is formed in a discontinuous area of the upper doping zone inside the detector array.
[0041] An advantageous embodiment of the invention provides that additional contact connection is arranged essentially centrally relative to an assigned quench resistance area.
[0042] With respect to the radiation detector system, in an advantageous embodiment of the invention it may be provided that an additional contact connection is still formed on the semiconductor photodetector and assigned to the lower doping zone and the control circuit is coupled and still configured on the additional contact connection to capture a measured value for the quench resistance of the semiconductor photodetector, and to provide a control signal derived therefrom for the control potential that is to be applied to the first additional doping zone. Multiple control circuits and/or a control circuit have multiple resistance measurement and adjustment structures may be provided.
[0043] FIG. 1 shows a schematic view of a cross-section through a portion of a known semiconductor photoconductor. An upper doping zone 3 is formed extending laterally and continuously on an upper side 2 in a substrate 1 made from a semiconductor material. Upper doping zone 3 is doped according to a first doping type, which may be either a p-doping or an n-doping type. Without limitation to the general premise, it will be assumed in the following that the doping in the exemplary embodiment represented is of the p-doping type. A lower doping zone 4 is formed facing upper doping zone 3 , which lower doping zone extends laterally and is constructed discontinuously in intermediate areas 5 . Lower doping zone 4 is doped according to a second doping type that differs from the first doping type. In the chosen embodiment, this means that lower zone 4 is provided with n-doping.
[0044] An area of high field strength 6 is formed between upper doping zone 3 and lower doping zone 4 , which area causes the avalanche effect in the semiconductor photodetector during radiation detection and may therefore also be referred to as the avalanche area. Avalanche like multiplication takes place in area of high field strength 6 after the creation of charge carriers due to radiation absorption, particularly of single photons.
[0045] A contacting layer 8 is produced on a rear side 7 of substrate 1 by n-doping. During production of a semiconductor photodetector, rear contacting layer 8 may be arranged on a carrier substrate (not shown) directly or indirectly over one or more layers. In the known semiconductor photodetector as shown in FIG. 1 , a quench resistance area 9 extends between lower doping zone 4 and contacting layer 8 , this quench resistance area being an area of substrate 1 that is unimpoverished in terms charge carriers, and the substrate in turn is doped according to the second doping type, corresponding in the chosen embodiment to n-doping. Areas of an impoverishment zone 10 are formed between the quench resistance areas 9 . These form isolating area between quench resistance areas 9 . Quench resistance areas 9 and impoverishment zones 10 are formed when a working voltage is applied during operation of the semiconductor photodetector in such manner that quench resistance areas 9 are still electrically conductive in the working point, whereas the resistance in impoverishment zones 10 is in the order of giga-ohms. Together with lower doping zones 4 , this gives rise to a spatial structure that is mushroom-shaped or cylindrically symmetrical.
[0046] In the following, exemplary embodiments of the invention will be explained in greater detail with reference to FIGS. 2 to 7 . Features that are identical to those in FIG. 1 will be identified using the same reference numbers in FIGS. 2 to 8 .
[0047] FIG. 2 shows a schematic view of a cross-section through a portion of a semiconductor photoconductor that has additional doping zones in substrate 1 compared with the known detector of FIG. 1 . Initially, a first additional doping zone 11 is provided, which is doped according to the first doping type, corresponding to p-doping in the embodiment chosen here. First additional doping zone 11 is arranged to extend laterally in substrate 1 in the area between lower doping zone 4 and contacting layer 8 . First additional doping zone 11 is also discontinuous in an area below lower doping zone 4 . Impoverishment zone 10 extends in this area. In the lateral direction, the portions of first additional doping zone 11 include at least the area of intermediate area 5 and extend to below lower doping zone 4 .
[0048] According to FIG. 2 , a second additional doping zone 12 is also provided, and this is doped according to the second doping type, corresponding in the chosen embodiment to n-doping. Second additional doping zone 12 is formed in an area in substrate 1 that includes lower doping zone 4 and first additional doping zone 11 as well at the region between these two zones. In the embodiment shown in FIG. 2 , second additional doping zone 12 is produced so as to overlap with lower doping zone 4 . Alternatively, (not shown), it may be provided that second additional doping zone 12 is arranged deeper in substrate 1 , for example adjacent to or even overlapping with first additional doping zone 11 . The representation in FIG. 2 shows that second additional doping zone 12 is not limited laterally, but rather extends continuously.
[0049] Second additional doping zone 12 impoverishes intermediate area 5 located between avalanche areas 6 entirely in terms of charge carriers, thereby guaranteeing the separation of avalanche area 6 and to this extent a separation of pixel elements in the semiconductor photodetector's detector array. At the same time, second additional doping zone 12 forms a potential barrier between upper doping zone 3 and first additional doping zone 11 , so that these two doping zones may be connected to different electrical potentials. This enables the avalanche breakdown in the area of high electrical field strength 6 to be controlled regardless of the setting of the quench resistance in quench resistance area 9 .
[0050] In FIG. 2 , dashed line 13 indicates the centre of avalanche area 6 , that is to say the centre of an associated pixel element. With regard to their two-dimensional shape, these areas may be circular or hexagonal for example.
[0051] FIG. 3 shows a schematic view of a cross-section through a portion of a semiconductor photoconductor that, like the detector in FIG. 2 , has a first and a second additional doping zone 11 , 12 , but unlike the embodiment of FIG. 2 second additional doping zone 12 is limited laterally in such manner that it only extends in intermediate area 5 and does not laterally include the area of lower doping zone 4 . In this variation also, second additional doping zone 12 impoverishes intermediate area 5 and forms the potential barrier between upper doping zone 3 and first additional doping zone 11 .
[0052] FIG. 4 shows a schematic view cross section of a semiconductor photoconductor in which first additional doping zone 11 is connected to a contact connection 20 that in the embodiment shown is formed with doping zones 21 , . . . , 23 that overlap one another in conducting manner, and with an external contact 24 . In this way, an electrical connection is enabled with first additional doping zone 11 , to enable a control potential to be applied, for example. The doping zones 21 , . . . , 23 that overlap in conducting manner are doped according to the first doping type, corresponding in the chosen embodiment to p-doping. Connecting contact 20 is electrically isolated from upper doping zone 3 and in the embodiment shown is located outside the active detector array, which is formed by the pixel elements assigned to avalanche areas 6 and the non-active intermediate areas 5 located between them.
[0053] In general, a single contact connection 20 is sufficient to connect first additional doping zone 11 , since first additional doping zone 11 extends in a laterally contiguous plane and recesses are formed below avalanche areas 6 . Since upper doping zone 3 and first additional doping zone 11 are separated or decoupled by the potential barrier provided by second additional doping zone 12 , a different potential than the one applied to upper doping zone 3 may be applied to first additional doping zone 11 via contact connection 20 . In this way, they may be controlled independently of one another.
[0054] FIG. 5 shows a schematic view of a cross-section through a portion of a semiconductor photoconductor, wherein contact connection 20 for the first additional doping zone 11 of FIG. 4 is realised according to modified design. Compared with the embodiment of FIG. 4 , two of the conductively overlapping doping zones 21 , 22 are omitted. However, the potential of first additional doping zone 11 may still be controlled via contact connection 20 . Since no direct potential barrier is created in semiconductor area 25 between doping zone 23 and the assigned first additional doping zone 11 , increasing the potential at external contact 24 causes charge carriers to flow from the assigned first additional doping zone 11 , through semiconductor area 25 , and into doping zone 23 , where the potential of the assigned first additional doping zone 11 is also raised very rapidly. The reverse process of reducing the potential takes place very slowly, since in this case a two-dimensional potential barrier is formed between doping zone 23 and first additional doping zone 11 , strongly inhibiting the direct exchange of charge carriers. The potential of first additional doping zone 11 thus initially remains at a preset value and is changed to the space charge depth solely by charge carriers generated by light or darkness that flow into the region surrounding first additional doping zone 11 until the two-dimensional potential barrier has been eliminated. Any charge carriers that flow into this region subsequently are dissipated towards doping zone 23 . After this point the value of the potential of first additional doping zone 11 remains essentially unchanged.
[0055] FIG. 6 shows a schematic view of a cross-section through a portion of a semiconductor photoconductor in which a further contact connection 30 is realised in the area of upper side 2 of substrate 1 , and is in contact with lower doping zone 4 of a single pixel. Upper doping zone 3 is discontinuous in the proximity of further contact connection 30 . Further contact connection 30 is created with a contact connection doping zone 31 and an external contact 32 . The lateral separation between upper doping zone 3 and contact connection doping zone 31 is sufficient to prevent an avalanche breakdown between the two doping zones.
[0056] With a bias voltage at external contact 32 against the potential on substrate 1 at contacting layer 8 , a current may now be measured by contact connection doping zone 31 , lower doping zone 4 , quench resistance area 9 and contacting layer 8 of a single pixel. In this case, the height of the substrate doping in quench resistance area 9 and the formation of the shape of this area due to the shift of the limits of impoverishment zones by means of the bias voltage at first additional doping zone 11 are most important in determining the magnitude of the quench resistance to be measured as a function of the selected doping conditions. The quench resistance areas 9 are more critical elements in determining the measurement value for quench resistance than all other regions through which the current flows.
[0057] This may now be exploited as shown in FIG. 7 to couple a control circuit 40 between additional contact connection 30 and first additional doping zone 11 in a radiation detector system, which control circuit is particularly usable for stabilising the working point. Starting from a reference potential, a current is supplied to additional contact connection 30 from current source 42 . A voltage difference now arises between additional contact connection 30 and the potential on the rear contacting layer 8 depending on the working point potential at first additional doping zones 11 . This voltage difference is evaluated and converted to an assigned control signal for the potential at first additional doping zones 11 by control circuit 40 . Alternatively, a design is possible as a bridge circuit, without a current source. For adjustment, control circuit 40 is always configured so that the quench resistance may be measured and on the basis of this a control signal for the potential may be made available at first additional doping zone 11 .
[0058] FIG. 8 is a schematic view of a detector array 70 for a semiconductor photodetector with individual pixel elements 71 and non-active areas 72 between these. Additional contact connector 30 is created in the area of detector array 70 , and is connected towards the edge via a contacting element 73 .
[0059] The features of the invention disclosed in the aforegoing description, the claims and the drawing may be pertinent either alone or in any combination for the realisation of the different variants of the invention. | Semiconductor photodetectors are provided that may enable optimized usage of an active detector array. The semiconductor photodetectors may have a structure that can be produced and/or configured as simply as possible. A radiation detector system is also provided. | 7 |
TECHNICAL FIELD
The present invention relates to a speech coding apparatus and a speech coding method and more particularly relates to a speech coding apparatus and a speech coding method capable of deleting redundant inter-channel parameters.
BACKGROUND ART
Generally, a stereo speech coding method or a multi-channel speech coding method include two methods.
One is the method to individually encode different channel signals, and this method can be easily applied to stereo speech signals or multi-channel speech signals. However, since this method does not delete inter-channel redundancy, the entire coding bit rate becomes proportional to the number of channels, and hence results in a higher bit rate.
The other is the method to parametrically encode a stereo speech signal or a multi-channel speech signal. The basic principle of this method is as follows. That is, at first, a coding side down-mixes or transforms an input signal into a signal of fewer channels than (or the same number as) those of the input signal. Next, the coding side encodes the down-mixed or transformed signal using the conventional speech coding method. In parallel with this, the coding side calculates inter-channel parameters representing inter-channel relationship from an original signal, encodes and then transmits the inter-channel parameters to a decoding side such that the decoding side can generate a stereo image or a multi-channel image. This method can encode inter-channel parameters with a smaller amount of coding than the amount of coding to encode a speech signal itself, thus making it possible to realize a lower bit rate.
A parametric stereo coding system or a multi-channel coding system widely use a principal component analysis (PCA) (Non-Patent Literature 1), a binaural cue coding method (BCC) (Non-Patent Literature 2), an inter-channel prediction (ICP) (Non-Patent Literature 3), and intensity stereo (IS) (Non-Patent Literature 4). The above methods generate and then transmit certain inter-channel parameters to a decoding side. For example, a binaural cue coding method (BCC) generates inter-channel level difference (ICLD), inter-channel time difference (ICTD), and inter-channel coherence (ICC) as the inter-channel parameters. Also, as inter-channel parameters, an inter-channel prediction (ICP), intensity stereo (IS), and a principal component analysis (PCA) generate an inter-channel prediction coefficient, an energy scale coefficient, and a rotation angle, respectively.
Since BCC, ICP, IS, and PCA require to obtain highly precise inter-channel parameters, it is general to calculate and encode the inter-channel parameters on a subband basis.
FIG. 1 and FIG. 2 simply illustrate configurations of parametric multi-channel codecs, and the meanings of signs in FIG. 1 and FIG. 2 are as follows.
{x i — sb }: a series of multi-channel signals divided into a plurality of subbands (which represents signals in a frequency domain, a time domain, or a hybrid domain where the frequency domain and the time domain are combined)
{y i — sb }: a series of down-mixed or transformed signals calculated every subband (which are the signals in the same domain as {x i — sb })
{P i — sb }: a series of inter-channel parameters calculated every subband
The following will be explained assuming that down-mixing is performed.
At the coding side illustrated in FIG. 1 , inter-channel parameter generating section 101 down-mixes input signals {x i — sb } by BCC, PCA or the like, and generates down-mixed signals {y i — sb } and inter-channel parameters {P i — sb }.
Coding section 102 encodes down-mixed signal {y i — sb }, and coding section 103 (inter-channel parameter coding section), which is separately provided, encodes the inter-channel parameters {P i — sb }.
Multiplexing section 104 multiplexes coding parameters of down-mixed signals {y i — sb } and coding parameters of inter-channel parameters {P i — sb }, which generates a bit stream. This bit stream is transmitted to a decoding side.
At the decoding side illustrated in FIG. 2 , demultiplexing section 201 demultiplexes the bit stream to obtain coding parameters of the down-mixed signals and the inter-channel parameters.
Decoding section 202 performs decoding processing using the coding parameters of the down-mixed signals, and generates decoded down-mixed signals {y{tilde over ( )} i — sb }.
Decoding section 203 (inter-channel parameter decoding section) performs decoding processing using the coding parameters of the inter-channel parameters, and generates decoded inter-channel parameters {P{tilde over ( )} i — sb }.
Inter-channel parameter applying section 204 up-mixes decoded down-mixed signals {y{tilde over ( )} i — sb } using spatial information represented by the decoded inter-channel parameters {P{tilde over ( )} i — sb }, and generates decoded signals {x{tilde over ( )} i — sb }.
Non-Patent Literature 1 describes a codec based on a principal component analysis (PCA) in the frequency domain. FIG. 3 and FIG. 4 illustrate configurations of a coding apparatus and a decoding apparatus based on PCA in Non-Patent Literature 1. The meanings of signs are as follows.
{L sb (f)}: left signals divided into a plurality of subbands
{R sb (f)}: right signals divided into a plurality of subbands
{Pc sb (f)}: principal-component signals calculated every subband by a principal component analysis
{A sb (f)}: ambient signals calculated every subband by a principal component analysis
{θ sb }: rotation angles calculated every subband by a principal component analysis
{PcAR sb }: energy ratios of principal component signals to ambient signals, the ratios calculated every subband
At a coding side illustrated in FIG. 3 , principal component analyzing section 301 transforms input left signals {L sb (f)} and input right signals {R sb (f)} into principal-component signals {Pc sb (f)} and ambient signals {A sb (f)}. In this transforming processing, the rotation angles each representing a transform degree are calculated every subband as the following.
(
Equation
1
)
θ
sb
=
1
2
tan
-
1
(
2
∑
f
=
sb
_
start
|
sb
_
end
L
sb
(
f
)
*
R
sb
(
f
)
∑
f
=
sb
_
start
sb
_
end
L
sb
(
f
)
2
-
∑
f
=
sb
_
start
sb
_
end
R
sb
(
f
)
2
)
θ
sb
=
θ
sb
+
π
2
if
θ
sb
<
0
[
1
]
The transform of a principal component analysis is performed as the following equation.
(Equation 2)
Pc sb ( f )= L sb ( f )*cos θ sb +R sb ( f )*sin θ sb
A sb ( f )= R sb ( f )*cos θ sb −L sb ( f )*sin θ sb [2]
Monaural coding section 303 encodes principal-component signals {Pc sb (f)}.
Coding section 302 (rotation angle coding section) encodes rotation angles {θ sb }.
Ambient signals {A sb (f)} are not regarded as important and thereby are not directly encoded. Energy parameter extracting section 304 calculates energy ratios {PcAR sb } of principal-component signals to ambient signals, and coding section 305 (energy ratio coding section) encodes the energy ratios {PcAR sb } and generates energy ratio coding parameters. The energy ratios {PcAR sb } are calculated as the following equation.
(
Equation
3
)
PcAR
sb
=
∑
f
=
sb
_
start
sb
_
end
Pc
sh
(
f
)
2
∑
f
=
sb
_
start
sb
_
end
A
sb
(
f
)
2
[
3
]
Multiplexing section 306 multiplexes coding parameters of principal-component signals {Pc sb (f)}, rotation angles {θ sb }, and energy ratios {PcAR sb }, and transmits a bit stream to a decoding side.
At the decoding side illustrated in FIG. 4 , demultiplexing section 401 demultiplexes the bit stream, and obtains coding parameters of the principal-component signals, coding parameters of the rotation angles, and coding parameters of the energy ratios.
Decoding section 402 (rotation angle decoding section) decodes the coding parameters of the rotation angles and outputs the decoded rotation angles {θ{tilde over ( )} i — sb } to principal component combining section 406 .
Monaural decoding section 403 decodes the coding parameters of the principal-component signals, generates and then outputs decoded principal-component signals {P{tilde over ( )}c sb (f)} to principal component combining section 406 and ambient signal combining section 405 .
Decoding section 404 (energy ratio decoding section) decodes the coding parameters of the energy ratios and generates decoded energy ratios {P{tilde over ( )}cAR sb } of the principal-component signals to the ambient signals.
By scaling the decoded principal-component signals {P{tilde over ( )}c sb (f)} by the decoded energy ratios, ambient signal combining section 405 generates decoded ambient signals {A{tilde over ( )} sb (f)}.
Principal component combining section 406 inversely transforms decoded principal-component signals {P{tilde over ( )}c sb (f)} and decoded ambient signals {A{tilde over ( )} sb (f)} by decoded rotation angles {θ{tilde over ( )} i — sb }, and generates decoded left signals {L{tilde over ( )} sb (f)} and decoded right signals {R{tilde over ( )} sb (f)}. This inverse transformation is performed as the following equation.
(Equation 4)
{tilde over (L)} sb ( f )= {tilde over (P)}c sb ( f )*cos {tilde over (θ)} sb −Ã sb ( f )*sin {tilde over (θ)} sb
{tilde over (R)} sb ( f )= {tilde over (P)}c sb ( f )*sin {tilde over (θ)} sb +Ã sb ( f )*cos {tilde over (θ)} sb [4]
In the case that the ambient signals are not encoded, the inverse transformation is performed as the following equation.
(Equation 5)
{tilde over (L)} sb ( f )= {tilde over (P)}c sb ( f )*cos {tilde over (θ)} sb
{tilde over (R)} sb ( f )= {tilde over (P)}c sb ( f )*sin {tilde over (θ)} sb [5]
CITATION LIST
Non-Patent Literature
NPL 1
Manuel Briand, David Virette and Nadine Martin “Parametric coding of stereo audio based on principal component analysis”, Proc of the 9 th International Conference on Digital Audio Effects, Montreal, Canada, Sep. 18-20, 2006.
NPL 2
Christof Faller and Frank Baumgarte “Binaural Cue Coding—Part II: Schemes and Applications”, IEEE Transactions on Speech and Audio Processing, Vol. 11, No 6, November 2003
NPL 3
Hendrik Fuchs “Improving Joint Stereo Audio Coding by Adaptive Inter-channel Prediction”, Proc of IEEE ASSP Workshop on Applications of Signal Processing to Audio and Acoustics, New Paltz, N.Y., USA, Oct. 17-20, 1993
NPL 4
Jurgen Herre, “From Joint Stereo to Spatial Audio Coding—Recent Progress and Standardization”, Proc of the 7th International Conference on Digital Audio Effects, Naples, Italy, Oct. 5-8, 2004.
SUMMARY OF INVENTION
Technical Problem
Irrespective of coding quality or signal-level sizes of down-mixed signals {y i — sb }, the above conventional art encodes inter-channel parameters at a predetermined bit rate. Even when the down-mixed signals are not encoded at all in one or a plurality of subbands, the inter-channel parameter coding is performed irrespective of this situation.
Here, let us consider, as an example, a case where down-mixed signals of one or a plurality of subbands are not encoded, in the case of an extremely low bit rate. In these subbands where down-mixed signals are not encoded, the inter-channel parameters are unnecessary in generating multi-channel speech signals, and coding of these unnecessary parameters results in wasting bits used in the coding processing.
Hereinafter, a case will be described exemplifying the above codec based on a principal component analysis in the frequency domain.
It is assumed that when input signals are represented as L(n) and R(n), these signals can be represented as L(n)=S(n)+C(n) and R(n)=S(n)+B(n) (S(n) means the main source signal, and C(n) and B(n) means certain ambient noise).
In the case of the frequency domain, L(f)=S(f)+C(f) and R(f)=S(f)+B(f) hold true. In the subband where S(f) is not so strong, the ambient noise is dominant; that is, C(f) is dominant in L(f) and B(f) is dominant in R(f). In this case, these types of subbands are not so important in the whole spectrum that signals in these subbands are not encoded in the case of a low bit rate. Therefore, coding of rotation angles in these subbands is essentially not necessary. For this reason, the conventional art which always encodes the rotation angles of all subbands wastes the bits allocated to the coding of the rotation angles in these subbands.
Referring to FIG. 5 illustrating the above problematic case, under the condition of a low bit rate, the coding side does not encode principal-component signal Pc 2 (f) of the second subband of which energy of the principal-component signal is smaller than the energy of other subbands. Therefore, in the decoding side, the decoded principal-component signal of the second subband is 0. Since ambient signals are generated by scaling the principal-component signals, the ambient signal of the second subband also is 0. In this case, even if the rotation angle has any value, decoded left signal L{tilde over ( )} 2 (f) and decoded right signal R{tilde over ( )} 2 (f) of the second subband become 0. That is, the decoded left signal and the decoded right signal of the second subband are the same regardless of whether or not the rotation angle is transmitted.
It is therefore an object of the present invention to provide a speech coding apparatus and a speech coding method capable of deleting the redundant inter-channel parameters.
Solution to Problem
In the first aspect of the present invention, before encoding and transmitting inter-channel parameters, a coding apparatus analyzes signal characteristics of each subband signal and checks whether or not it is necessary to transmit inter-channel parameters. Then, the coding apparatus selects inter-channel parameters not necessary to be transmitted and deletes the parameters from coding targets.
By this means, it is possible to delete the unnecessary inter-channel parameters from the coding targets and to prevent encoding the unnecessary parameters, which makes it possible to improve a coding efficiency without wasting bits.
In the second aspect of the present invention, redundant parameters are selected by a closed loop method. Introduction of a local decoding section at the coding side and analysis of signal coding quality selects the redundant parameters. By analyzing the energy or amplitude of decoded down-mix signals generated via the local decoding section, the subband with small energy or amplitude is regarded as a subband having a redundant inter-channel parameter. Deletion of the inter-channel parameter of this subband from the coding targets prevents a possibility of decreasing sound quality.
By this means, the local decoding section can select the subband having the redundant parameter (unimportant inter-channel parameter).
In the third aspect of the present invention, the redundant parameters are selected by an open loop method. An analysis of the characteristics of transformed or down-mixed original signals selects the redundant parameters.
Therefore, the present embodiment does not require a local decoding section and is useful in the condition incapable of using the local decoding section. Also, absence of the local decoding section can reduce the amount of calculations.
In the fourth aspect of the present invention, after decoding, the decoding side analyzes the transformed or down-mixed signals and selects the subband without an inter-channel parameter. Therefore, flag signals are not required, the signals reporting to the decoding section that a specific subband does not include the inter-channel parameter.
By this means, unnecessity of additional information representing the flag signals can improve the coding efficiency.
The fifth aspect of the present invention uses the bits saved by applying the present invention in order to encode certain more important signals (for example, the coding parameters of the principal-component signals, and the coding parameters of the transformed or down-mixed signals).
Thus, realization of more precise bit allocation can improve the coding efficiency.
In the sixth aspect of the present invention, the decoding side predicts non-existent inter-channel parameters from parameters of adjacent subbands, parameters of a former frame, or both of them. The predicted value is used on inverse transformation or up-mixing.
By this means, it is possible to predict non-existent inter-channel parameters and to maintain spatial images.
The seventh aspect of the present invention applies the present invention for scalable coding. In each layer, before encoding and transmitting inter-channel parameters, the coding apparatus analyzes the characteristics of the transformed or down-mixed signals every subband signal, and checks whether or not it is necessary to transmit inter-channel parameters. Then, the coding apparatus selects the inter-channel parameter not necessary to be transmitted and deletes the parameter from the coding targets. In the case of a layer where inter-channel parameters are necessary to generate input signals, the coding apparatus transmits the inter-channel parameters.
By this means, since the coding apparatus transmits the inter-channel parameters only in the case of the layer requiring the inter-channel parameters, it is possible to realize precise bit allocation.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 illustrates a coding side configuration in parametric multi-channel speech coding;
FIG. 2 illustrates a decoding side configuration in parametric multi-channel speech coding;
FIG. 3 illustrates a coding side configuration in stereo codec based on PCA;
FIG. 4 illustrates a decoding side configuration in stereo codec based on PCA;
FIG. 5 illustrates a problem in stereo codec based on PCA;
FIG. 6 illustrates a configuration of a speech coding apparatus according to embodiment 1 of the present invention in stereo codec based on PCA;
FIG. 7 illustrates a coding processing according to embodiment 1 of the present invention in stereo codec based on PCA;
FIG. 8 illustrates a configuration of a speech decoding apparatus according to embodiment 1 of the present invention in stereo codec based on PCA;
FIG. 9 illustrates decoding processing according to embodiment 1 of the present invention in stereo codec based on PCA;
FIG. 10 illustrates a configuration of a speech coding apparatus according to embodiment 2 of the present invention in multi-channel speech coding;
FIG. 11 illustrates coding processing according to embodiment 2 of the present invention in multi-channel speech coding;
FIG. 12 illustrates a configuration of a speech decoding apparatus according to embodiment 2 of the present invention in multi-channel speech coding;
FIG. 13 illustrates decoding processing according to embodiment 2 of the present invention in multi-channel speech coding;
FIG. 14 illustrates a configuration of a speech decoding apparatus according to embodiment 3 of the present invention in multi-channel speech coding;
FIG. 15 illustrates decoding processing according to embodiment 3 of the present invention in multi-channel speech coding;
FIG. 16 illustrates a configuration of a speech coding apparatus according to embodiment 4 of the present invention in multi-channel speech coding;
FIG. 17 illustrates coding processing according to embodiment 4 of the present invention in multi-channel speech coding;
FIG. 18 illustrates a configuration of a speech decoding apparatus according to embodiment 4 of the present invention in multi-channel speech coding;
FIG. 19 illustrates decoding processing according to embodiment 4 of the present invention in multi-channel speech coding;
FIG. 20 illustrates a configuration of a speech coding apparatus according to embodiment 5 of the present invention in multi-channel speech coding;
FIG. 21 illustrates coding processing according to embodiment 5 of the present invention in multi-channel speech coding;
FIG. 22 illustrates a configuration of a speech decoding apparatus according to embodiment 5 of the present invention in multi-channel speech coding; and
FIG. 23 illustrates decoding processing according to embodiment 5 of the present invention in multi-channel speech coding.
DESCRIPTION OF EMBODIMENTS
Embodiments of the present invention will now be described with reference to the accompanying drawings.
Embodiment 1
The present embodiment will be described referring to FIG. 6 to FIG. 9 .
FIG. 6 illustrates a configuration of speech coding apparatus 600 according to the present embodiment. FIG. 6 additionally includes local monaural decoding section 603 and redundant parameter deleting section 604 , in comparison with FIG. 3 . In FIG. 6 , descriptions on the components as the same as those in FIG. 3 will be omitted.
Local monaural decoding section 603 generates decoded principal-component signals such that a coding side can confirm the coding quality of the principal-component signals.
Through analysis of the coding quality of the decoded principal-component signals, redundant parameter deleting section 604 selects redundant parameters and deletes these parameters from coding targets.
The coding processing according to the present embodiment will be described referring to FIG. 7 .
As illustrated in FIG. 7 , spectra of the principal-component signals are encoded and decoded. Analyzing the decoded spectra after generating the decoded spectrum, shows that the principal component of the second subband is not encoded at all, and therefore the decoded spectrum of the second subband is 0. Thus, there is no need to encode the rotation angle of the second subband. For this reason, the rotation angle of the second subband is regarded as a redundant parameter, and this parameter is deleted from the coding targets before encoding.
FIG. 8 illustrates a configuration of speech decoding apparatus 800 according to the present embodiment. FIG. 8 additionally includes zero-value inserting section 804 , in comparison with FIG. 4 . In FIG. 8 , descriptions on the components as the same as those in FIG. 4 will be omitted.
Zero-value inserting section 804 analyzes the decoded principal-component signals, selects the subband without a rotation angle, and inserts a zero value to the subband, so that inverse transformation can be performed smoothly.
The decoding processing according to the present embodiment will be described referring to FIG. 9 .
As illustrated in FIG. 9 , analyzing the decoded principal-component signals after generating the decoded principal-component, shows that the decoded principal-component signal of the second subband is 0 and that the rotation angle in the second subband is not encoded. Therefore, the decoding side decodes only rotation angles of other subbands. Also, in order to perform decoding processing smoothly, the decoding side inserts a zero value as the decoded rotation angle of the second subband.
The present invention can be applied to encoding of the energy ratios of principal-component signals to ambient signals.
Embodiment 2
The present embodiment will be described referring to FIG. 10 to FIG. 13 . The meanings of signs in FIG. 10 to FIG. 13 are as follows.
{x i — sb }: multi-channel signals divided into a plurality of subbands (which represents signals in a frequency domain, a time domain, or a hybrid domain where the frequency domain and the time domain are combined)
{y i — sb }: down-mixed or transformed signals divided into a plurality of subbands (which are the signals in the same domains as {x i — sb })
{P i — sb }: inter-channel parameters calculated every subband
{x{tilde over ( )} i — sb }: decoded signals of {x i — sb }
{y{tilde over ( )} i — sb }: decoded signals of {y i — sb }
{P{tilde over ( )} i — sb }: decoded inter-channel parameters
The present embodiment deletes redundant parameters in multi-channel speech coding.
FIG. 10 illustrates a configuration of speech coding apparatus 1000 according to the present embodiment.
In speech coding apparatus 1000 , inter-channel parameter generating section 1001 transforms or down-mixes input signals {x i — sb } into {y i — sb } by BCC, PCA or the like. During transforming and down-mixing processing, inter-channel parameter generating section 1001 also generates inter-channel parameters {P i — sb }.
Coding section 1002 encodes the transformed or down-mixed signals {y i — sb }.
Local decoding section 1003 generates signals transformed or down-mixed after decoding, such that the coding side can identify coding quality of the transformed or down-mixed signals.
By analyzing the coding quality of the transformed or down-mixed signals, deleting section 1004 selects redundant parameters and deletes these parameters from coding targets.
Coding section 1005 (inter-channel parameter coding section) encodes the remaining inter-channel parameters {P′ i — sb } after the deletion of the redundant parameters.
Multiplexing section 1006 multiplexes coding parameters of {y i — sb } and coding parameters of {P′ i — sb }, generates and then transmits a bit stream to the decoding side.
The coding processing according to the present embodiment will be described referring to FIG. 11 .
As illustrated in FIG. 11 , spectra of the transformed or down-mixed signals are encoded and decoded. Analyzing the decoded spectra after generating the decoded spectra, shows that, since the transformed or down-mixed signal, for example in the second subband, is critically weak (in an extreme case, the second subband is not encoded at all), the decoded signal is 0. In this case, there is no need to encode the inter-channel parameter of the second subband. Therefore, the inter-channel parameter of the second subband is regarded as the redundant parameter, and deletes this parameter from the coding targets before encoding.
There are many methods, such as the following two, to determine whether or not the decoded subband signals are sufficiently weak. However, the present invention is not limited to the following methods.
<Method 1> Case Where Signal Energy of Subband is Extremely Lower than Adjacent Subbands
Every subband, this method calculates energy {E sb } and energy ratios of the subband to the adjacent subbands, and then compares the energy ratios with a predetermined value E th (E th <1). When both energy ratios are smaller than E th , the subband signal is regarded as weak. For example, two energy ratios E 2 /E 1 and E 2 /E 3 are calculated in the second subband. If E 2 /E 1 <E th and E 2 /E 3 <E th hold true, the signal of the second subband is regarded as weak in this case. In this case, the inter-channel parameter of the second subband is regarded as the redundant parameter.
<Method 2> Case Where Subband Signal is Close to or Lower than Masking Curve
Every subband, this method calculates energy {E sb } and masking curve level {M sb }, and then compares the masking curve level with the subband energy. In this case, it is possible to define another threshold M th (M th >0). When the subband energy is smaller than or close to a masking curve, that is, E sb <M sb +M th holds true, the subband signal is regarded as weak. For example, subband energy E 2 is compared with masking curve level M 2 . If E 2 <M 2 +M th holds true, the signal of the second subband is regarded as weak. Therefore, the inter-channel parameter in the second subband is regarded as the redundant parameter.
FIG. 12 illustrates a configuration of speech decoding apparatus 1200 according to the present embodiment.
In speech decoding apparatus 1200 , demultiplexing section 1201 demultiplexes the bit stream.
Decoding section 1202 decodes coding parameters of {y i — sb }, and generates transformed or down-mixed signals {y{tilde over ( )} i — sb }.
Decoding section 1203 (inter-channel parameter decoding section) decodes coding parameters of {P′ i — sb }, and generates decoded inter-channel parameters {P{tilde over ( )}′ i — sb }.
Zero-value inserting section 1204 analyzes the decoded spectra of the transformed or down-mixed signals, selects the subband without an inter-channel parameter, and inserts a zero value in the subband so that inverse transformation or up-mixing can be performed smoothly.
By using spatial information represented by the decoded inter-channel parameters {P{tilde over ( )} i — sb }, inter-channel parameter applying section 1205 inversely transforms or up-mixes decoded signals {y{tilde over ( )} i — sb } to generate {x{tilde over ( )} i — sb }.
The decoding processing according to the present embodiment will be described referring to FIG. 13 .
As illustrated in FIG. 13 , analyzing the decoded spectra after generating the decoded spectra, shows that the decoded signal of the second subband is critically weak (in an extreme case, the decoded signal is 0). That is, the inter-channel parameter of the second subband is not encoded. Thus, only inter-channel parameters of other subbands are decoded. In order to perform the decoding processing smoothly, a zero value is inserted to the decoded inter-channel parameter of the second subband. The method of the decoding side to determine whether or not the inter-channel parameters are encoded is the same as the method of the coding side for the purpose of maintaining consistency with the coding side.
As described above, before encoding and transmitting inter-channel parameters, the present embodiment analyzes the signal characteristics per signal transformed in each subband, and checks whether or not it is necessary to transmit the inter-channel parameters. Then, the inter-channel parameter not necessary to be transmitted is selected and deleted from the coding targets.
Therefore, according to the present embodiment, by deleting unnecessary inter-channel parameters from the coding targets, it is possible to prevent encoding the unnecessary parameters and hence to improve a coding efficiency.
Also, according to the present invention, the redundant parameters are selected by a closed loop method. That is, by analyzing the coding quality of signals, the local decoding section in the coding side selects redundant parameters.
Thus, according to the present embodiment, the local decoding section can specify the subband including the redundant parameter (unimportant inter-channel parameter). Thus, the possibility of decreasing sound quality is avoided.
Also, according to the present invention, the decoding side selects a subband in which no inter-channel parameter exists, by decoding and analyzing the transformed or down-mixed signals. Therefore, a flag signal reporting to the decoding section that no inter-channel parameter exists in a specific subband is not required.
As mentioned above, according to the present embodiment, unnecessity of additional information to represent the flag signals can improve the coding efficiency.
Embodiment 3
The present embodiment will be described referring to FIG. 14 and FIG. 15 . The meanings of signs in FIG. 14 and FIG. 15 are the same as those of embodiment 2.
In the present embodiment, the decoding side predicts the non-existent inter-channel parameter, from parameters of adjacent subbands, parameters of the former frame, or both of them. The predicted value is used in performing inverse transformation or up-mixing.
FIG. 14 illustrates a configuration of speech decoding apparatus 1400 according to the present embodiment. In FIG. 14 , zero-value inserting section 1204 illustrated in FIG. 12 is replaced with missing parameter predicting section 1404 . In FIG. 14 , descriptions on the components as the same as those in FIG. 12 will be omitted.
In speech decoding apparatus 1400 , missing parameter predicting section 1404 predicts the non-existent inter-channel parameter by using the parameters of the adjacent subbands or the parameters of the former frame without insertion of a zero value into the non-existent inter-channel parameter.
The decoding processing according to the present embodiment will be described referring to FIG. 15 .
FIG. 15 illustrates an example of a case where, because of the absence of the inter-channel parameter in the second subband in the decoding side, the decoding side predicts this inter-channel parameter from the parameters of the adjacent subbands or the parameters of the former frame.
There are many other methods to predict non-existent inter-channel parameters.
For example, as the following equation, there is a method to interpolate the non-existent inter-channel parameter using the parameters of the adjacent subbands.
(
Equation
6
)
P
~
i
_
2
=
P
~
i
_
1
+
P
~
i
_
3
2
[
6
]
Also, as the following equation, there is a method to predict a non-existent inter-channel parameter using the parameters of the former frame. This method is effective when the spatial image is stable in a time domain.
(Equation 7)
{tilde over (P)} i — 2 ={tilde over (P)} i — 2 — old [7]
As described above, according to the present embodiment, the decoding side predicts the non-existent inter-channel parameter from the parameters of the adjacent subbands, the parameters of the former frame, or both of them. The predicted value is used on performing inverse transformation or up-mixing.
By this means, it is possible to predict the non-existent inter-channel parameters to maintain spatial images.
Embodiment 4
The present embodiment will be described referring to FIG. 16 to FIG. 19 . The meanings of signs in FIG. 16 to FIG. 19 are as follows.
{x i — sb }: multi-channel signals divided into a plurality of subbands (which represents signals in a frequency domain, a time domain, or a hybrid domain where the frequency domain and the time domain are combined)
{y i — sb }: down-mixed or transformed signals divided into a plurality of subbands (which are the signals in the same domain as {x i — sb })
{P i — sb }: inter-channel parameters calculated every subband
{x{tilde over ( )} i — sb }: decoded signals of {x i — sb }
{y{tilde over ( )} i — sb }: decoded signals of {y i — sb }
{P{tilde over ( )} i — sb }: decoded inter-channel parameters
In the present invention, an open loop method selects redundant parameters. By analyzing the characteristics of the transformed or down-mixed original signal, the present embodiment selects the redundant inter-channel parameters and deletes the parameters from the coding targets.
FIG. 16 illustrates a configuration of speech coding apparatus 1600 according to the present embodiment.
In speech coding apparatus 1600 , inter-channel parameter generating section 1601 transforms or down-mixes input signal {x i — sb } into {y i — sb } by BCC, PCA or the like. During the transforming and down-mixing processing, inter-channel parameter generating section 1601 also generates inter-channel parameter {P i — sb }.
Coding section 1602 encodes the transformed or down-mixed signal {y i — sb }.
Signal analyzing section 1603 selects the redundant parameters by analyzing the signal characteristics of the transformed or down-mixed signal {y i — sb }.
Redundant parameter deleting section 1604 selects the redundant parameters and deletes the parameters from the coding targets.
Coding section 1605 (inter-channel parameter coding section) encodes remaining inter-channel parameters {P′ i — sb } after deleting the redundant parameters.
Multiplexing section 1606 multiplexes coding parameters of {y i — sb } and coding parameters of {P′ i — sb }, generates and then transmits a bit stream to the decoding side.
The coding processing according to the present embodiment will be described referring to FIG. 17 .
As illustrated in FIG. 17 , the characteristics of the transformed or down-mixed signals are analyzed by an energy analysis, a psychoacoustic analysis, a bit allocating analysis, or the like. The analysis shows that the transformed or down-mixed signal is critically weak, for example, in the second subband. In this case, there is no need to encode the inter-channel parameters of the second subband. Therefore, the inter-channel parameters of the second subband is regarded as the redundant parameters, and deleted from the coding targets before encoding.
There are many methods, such as the following two, to determine whether or not the subband signals are sufficiently weak. However, the present invention is not limited to the followings.
<Method 1> Case Where Signal Energy of Subband is Extremely Lower than Adjacent Subbands
Every subband, this method calculates energy {E sb } and energy ratios of the subband to the adjacent subbands, and then compares the energy ratios with a certain predetermined value E th (E th <1). When both energy ratios are smaller than E th , the subband signal is regarded as weak. For example, two energy ratios E 2 /E 1 and E 2 /E 3 are calculated in the second subband. If E 2 /E 1 <E th and E 2 /E 3 <E th hold true, the signal of the second subband is regarded as weak in this case. In this case, the inter-channel parameter of the second subband is regarded as the redundant parameter.
<Method 2> Case Where Subband Signal is Close to or Lower than Masking Curve
Every subband, this method calculates energy {E sb } and masking curve level {M sb }, and then compares the masking curve level with the subband energy. In this case, it is possible to define another threshold M th (M th >0). When the subband energy is smaller than or close to a masking curve, that is, E sb <M sb +M th holds true, the subband energy is regarded as weak. For example, when subband energy E 2 is compared with masking curve level M 2 and thereby E 2 <M 2 +M th holds true, the signal of the second subband is regarded as weak. The inter-channel parameter in the second subband is regarded as the redundant parameter.
FIG. 18 illustrates a configuration of speech decoding apparatus 1800 according to the present embodiment.
In speech decoding apparatus 1800 , demultiplexing section 1801 demultiplexes the bit stream.
Decoding section 1802 decodes coding parameters of {y i — sb }, and generates the transformed or down-mixed signals {y{tilde over ( )} i — sb }.
Decoding section 1803 (inter-channel parameter decoding section) decodes coding parameters of {P′ i — sb }, and generates decoded inter-channel parameters {P{tilde over ( )}′ i — sb }.
Zero-value inserting section 1804 analyzes the decoded spectrum of the transformed or down-mixed signal, selects the subband without an inter-channel parameter, and inserts a zero value in the subband so that inverse transformation or up-mixing can be performed smoothly.
By using spatial information represented by decoded inter-channel parameters {P{tilde over ( )} i — sb }, inter-channel parameter applying section 1805 inversely transforms or up-mixes the decoded signals {y{tilde over ( )} i — sb } to generate {x{tilde over ( )} i — sb }.
The decoding processing according to the present embodiment will be described referring to FIG. 19 .
As illustrated in FIG. 19 , analyzing the decoded spectra after generating the decoded spectra, shows that the decoded signal of the second subband is critically weak (in an extreme case, the decoded signal is 0). That is, the inter-channel parameter of the second subband is not encoded. Thus, only inter-channel parameters of other subbands are decoded. In order to perform the decoding processing smoothly, a zero value is inserted to the decoded inter-channel parameter of the second subband. The method of the decoding side to determine whether or not the inter-channel parameters are encoded is the same as the method of the coding side for the purpose of maintaining consistency with the coding side.
According to the present invention, the redundant parameters are selected by an open loop method. That is, an analysis of the characteristics of transformed or down-mixed original signals selects the redundant parameters.
Therefore, the present embodiment does not require a local decoding section. Thus, the present embodiment is useful in the condition incapable of using the local decoding section. Also, absence of the local decoding section can reduce the amount of calculations.
Embodiment 5
The present embodiment will be described referring to FIG. 20 to FIG. 23 . The meanings of signs in FIG. 20 to FIG. 23 are as follows.
{x i — sb }: multi-channel signals divided into a plurality of subbands (which represents signals in a frequency domain, a time domain, or a hybrid domain where the frequency domain and the time domain are combined)
{y i — sb }: down-mixed or transformed signals divided into a plurality of subbands (which are the signals in the same domain as {x i — sb })
{P i — sb }: inter-channel parameters calculated every subband
{x{tilde over ( )} i — sb }: decoded signals of {x i — sb }
{y{tilde over ( )} i — sb }: decoded signals of {y i — sb }
{P{tilde over ( )} i — sb }: decoded inter-channel parameters
The present embodiment deletes redundant parameters in scalable codec.
FIG. 20 illustrates a configuration of speech coding apparatus 2000 according to the present embodiment.
In speech coding apparatus 2000 , inter-channel parameter generating section 2001 transforms or down-mixes input signals {x i — sb } into {y i — sb } by BCC, PCA or the like. During transforming and down-mixing processing, inter-channel parameter generating section 2001 also generates inter-channel parameters {P i — sb }.
Scalable coding section 2002 encodes the transformed or down-mixed signals {y i — sb }.
Scalable local decoding section 2003 generates decoded signals of layers, such that the coding side can identify coding quality of the transformed or down-mixed signals.
By analyzing the coding quality of the transformed or down-mixed signal, scalable redundant parameter deleting section 2004 selects redundant parameters and deletes these parameters from coding targets.
Coding section 2005 (inter-channel parameter coding section) encodes the remaining inter-channel parameters {P′ i — sb } after deleting the redundant parameters.
Multiplexing section 2006 multiplexes the coding parameters of {y i — sb } and coding parameters of {P′ i — sb }, generates and then transmits a bit stream to the decoding side.
The coding processing according to the present embodiment will be described referring to FIG. 21 .
As illustrated in FIG. 21 , spectra of the transformed or down-mixed signals are encoded and decoded. Analyzing the decoded spectra after generating the decoded spectra, shows that since the transformed or down-mixed signals, for example, in the second subband in layer 1 of FIG. 21 , are critically weak (in an extreme case, the second subband is not encoded at all), the decoded signal is 0. In this case, in layer 1 , there is no need to encode the inter-channel parameter of the second subband. Therefore, in layer 1 , the inter-channel parameter of the second subband is regarded as the redundant parameter, and deletes this parameter from the coding targets before encoding.
On the other hand, in layer 2 , the decoded signal of the second subband is not weak, and hence it is necessary to encode the inter-channel parameter in order to prevent possible deterioration of sound quality. Therefore, it is layer 2 that firstly encodes the inter-channel parameter of the second subband.
There are many methods, such as the following two, to determine whether or not the subband signal is extremely weak. However, the present invention is not limited to the followings.
<Method 1> Case Where Signal Energy of Subband is Extremely Lower than Adjacent Subbands
Every subband, this method calculates energy {E sb } and energy ratios of the subband to the adjacent subbands, and then compares the energy ratios with a certain predetermined value E th (E th <1). When both energy ratios are smaller than E th , the subband signal is regarded as weak. For example, two energy ratios E 2 /E 1 and E 2 /E 3 are calculated in the second subband. If E 2 /E 1 <E th and E 2 /E 3 <E th hold true, the signal of the second subband is regarded as weak. The inter-channel parameter of the second subband is regarded as the redundant parameter.
<Method 2> Case Where Subband Signal is Close to or Lower than Masking Curve
Every subband, this method calculates energy {E sb } and masking curve level {M sb }, and then compares the masking curve level with the subband energy. In this case, it is possible to define another threshold M th (M th >0) When the subband energy is smaller than or close to a masking curve, that is, when E sb <M sb +M th holds true, the subband energy is regarded as weak. For example, when subband energy E 2 is compared with masking curve level M 2 and thereby E 2 <M 2 +M th holds true, the signal of the second subband is regarded as weak. The inter-channel parameter in this second subband is regarded as the redundant parameter.
FIG. 22 illustrates a configuration of speech decoding apparatus 2200 according to the present embodiment.
In speech decoding apparatus 2200 , demultiplexing section 2201 demultiplexes the bit stream in each layer.
Scalable decoding section 2202 decodes coding parameters of {y i — sb }, and generates transformed or down-mixed signals {y{tilde over ( )} i — sb }.
Decoding section 2203 (inter-channel parameter decoding section) decodes coding parameters of {P′ i — sb }, and generates decoded inter-channel parameters {P{tilde over ( )}′ i — sb }.
In each layer, zero-value inserting section 2204 analyzes the decoded spectrum of the transformed or down-mixed signal, selects the subband without an inter-channel parameter, and inserts a zero value in the subband so that inverse transformation or up-mixing can be performed smoothly.
By using spatial information represented by inter-channel parameters {P{tilde over ( )} i — sb }, inter-channel parameter applying section 2205 inversely transforms or up-mixes decoded signals {y{tilde over ( )} i — sb } to generate {x{tilde over ( )} i — sb }.
The decoding processing according to the present embodiment will be described referring to FIG. 23 .
As illustrated in FIG. 23 , analyzing the decoded spectra after generating the decoded spectra, shows that, in layer 1 , the decoded signal of the second subband is critically weak (in an extreme case, the decoded signal is 0). That is, the inter-channel parameter of the second subband is not encoded. Thus, only inter-channel parameters of other subbands are decoded. In order to perform the decoding processing smoothly, a zero value is inserted to the decoded inter-channel parameter of the second subband.
On the other hand, since the decoded signal of the second subband is not weak in layer 2 , it is necessary to encode the inter-channel parameter of the second subband.
The method of the decoding side to determine whether or not the inter-channel parameters are encoded is the same as the method of the coding side for the purpose of maintaining consistency with the coding side.
As described above, before encoding inter-channel parameters and transmitting the result, in each layer of scalable coding, the present embodiment analyzes the characteristics of transformed or down-mixed signals every subband and checks whether or not it is necessary to transmit the inter-channel parameters. Then, the inter-channel parameter not necessary to be transmitted is selected and deleted from the coding targets. Meanwhile, in the case of the layer requiring the inter-channel parameter so as to generate input signals, the inter-channel parameter is transmitted.
Therefore, the present invention can realize precise bit allocation so as to transmit the inter-channel parameter only for the layer requiring the inter-channel parameter.
The disclosure of Japanese Patent Application No. 2009-298321, filed on Dec. 28, 2009, including the specification, drawings and abstract, is incorporated herein by reference in its entirety.
INDUSTRIAL APPLICABILITY
The present invention is suitable for a communication apparatus performing speech coding, a communication apparatus performing speech decoding, and particularly a wireless communication apparatus.
REFERENCE SIGNS LIST
600 Speech coding apparatus
603 Local monaural decoding section
604 Redundant parameter deleting section
800 Speech decoding apparatus
804 Zero-value inserting section | Disclosed is an audio encoding device which removes unnecessary inter-channel parameters from the subject to be encoded, improving the encoding efficiency thereby. In this audio encoding device, a principal component analysis unit ( 301 ) converts an inputted left signal {L sb (f)} and an inputted right signal {R sb (f)} into a principal component signal {PC sb (f)} and an ambient signal {A sb (f)} and calculates for each sub-band, a rotation angle which indicates the degree of conversion; a monophonic encoding unit ( 303 ) encodes the principal component signal {Pc sb (f)}; a rotation angle encoding unit ( 302 ) encodes the angle of rotation {θ b }; a local monophonic decoding unit ( 603 ) creates a decoded principal component signal; and a redundant parameter elimination unit ( 604 ) identifies the redundant parameters by analyzing the encoding quality of the decoded principal component signal and eliminates the redundant parameters from the signal to be encoded. | 6 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims the benefit of provisional application # 60/469240
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] There are no rights to this invention made under federally sponsored research or development.
FIELD OF THE INVENTION
[0003] The device relates generally to the field of windmills or wind turbines for the production of electricity. More specifically it relates to the field of vertical axis wind turbines.
BACKGROUND OF THE INVENTION
[0004] Windmills may be constructed using either a horizontal axis, as in most modem wind turbines, or using a vertical axis, as in the earliest windmills. The first vertical axis windmills are usually attributed the to Persians or to the Chinese during the period 500 to 900 C.E. These windmills were used to grind grain or to pump water. Today however, horizontal axis wind turbines are the dominant variety and are used to generate electricity. They are being installed in large numbers, particularly in Europe and are able to produce megawatt quantities of electricity. These large wind turbines are expensive, costing approximately $1 million dollars each in 2003 and, for this reason, are usually owned by utilities. The diameters of the newest machines are 328 feet, with towers of 200 feet or more. These machines are clearly not appropriate for a small farmer wishing to extract energy from the wind to produce electricity for domestic use, for net metering, or for sale to electric grids.
[0005] Early in their careers sailors learn to beware of an accidental gybe when sailing, in particular when “running” with the wind. The danger of an accidental gybe is given by the following quote from the classic book of sailing “Chapman's book on Piloting: Seamanship and Small Boat Handling, 60 th Edition” by E. S. Malony: “Whenever jibing (gybing) or close to a jibe, watch for an accidental jibe—one for which the crew is not prepared. With inattentive steering the wind may catch the back side of the sail and throw the boom violently across the boat to the other side, risking serious damage to the rigging and to the heads of crewmembers.”
[0006] A vertical axis wind turbine would normally produce an uncontrolled gybe when the wind catches the back side of the sail. The energy of the wind in producing this uncontrolled gybe is normally lost and not used to add force to the rotation.
BRIEF SUMMARY OF THE INVENTION
[0007] Vertical axis wind turbines have not effectively captured the energy of the uncontrolled gybe that results when a sail points downwind. The present invention addresses and solves this problem by the use of strategically placed sail restraints.
[0008] In several aspects the invention consists of a tower onto which the device is mounted. In one aspect a number of vertical rotatable sails are mounted onto a horizontal rotatable framework. When the wind blows onto the device the sails on one side are feathered, and one or more sails on the other side are restrained from feathering by sail restraints. The sails that are restrained from feathering are pushed by the wind and cause the device to rotate. In another aspect each sail is positioned by a sail restraint so that it gybes at an earlier time than otherwise would occur, and a second sail restraint then captures the sail as it gybes, adding gybe energy to the rotation. The rotation of the device may be used to power an electric generator.
BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS
[0009] The invention is not intended to be limited to the precise arrangements and instrumentalities shown.
[0010] [0010]FIG. 1 is a perspective view of a first embodiment of the invention.
[0011] [0011]FIG. 2 is a cross sectional, overhead view of part of the embodiment shown in FIG. 1.
[0012] [0012]FIG. 3 is a cross sectional, overhead view of the embodiment shown in FIG. 1.
[0013] [0013]FIG. 4 is a cross sectional, overhead view of the embodiment shown in FIG. 1.
[0014] [0014]FIG. 5 is a side view of a lower end for use with an embodiment of the invention.
[0015] [0015]FIG. 6 is a side view of a sail for use with an embodiment of the invention.
[0016] [0016]FIG. 7 is a side view of a part of an embodiment of the invention.
[0017] [0017]FIG. 8. is a perspective view of remotely operated cables, for use with an embodiment of the invention.
[0018] [0018]FIG. 9 is a cross sectional, overhead view of an embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0019] Referring now to the drawing in FIG. 1 in detail, there is shown a perspective view of the structure of a self-feathering vertical axis wind turbine with controlled gybing. The direction of the incoming wind is indicated by the arrow in the upper right hand corner of the figure. A vertical tower 1 is secured to the ground or to any other secure structure. A cylindrical vertical member 2 or “tower-collar,” is mounted on said tower 1 and is able to rotate freely around the tower on thrust bearings 19 supported by a shaft-collar 3 secured to the base of the tower. Additional friction reducing radial bearings (not shown) may be mounted on the tower 1 between the tower-collar 2 and the tower 1 to reduce friction as the tower-collar rotates around the tower. Horizontal arms 4 are secured to the tower-collar. A vertical member, or “mast” 6 is secured to each horizontal arm 4 . A cylindrical vertical collar 5 or “mast-collar” is mounted on said mast 6 and is able to rotate freely around the mast 6 on friction-reducing bearings (not shown.) A rigid horizontal member, or “boom” 7 is secured to each mast-collar 5 near the boom 7 . Sails, 8 constructed of nonflexible or flexible material are secured to their booms 7 and mast-collars 5 . Additional strengthening and support of the sail 8 is provided by horizontal and vertical members forming a frame 9 around the sail 8 . An “inner sail restraint” 10 located between the tower-collar 2 and mast 6 is secured to the horizontal arm 4 . The angle formed by the boom 7 (when it is in contact with the inner sail restraint 10 ,) the mast 6 and the horizontal arm 4 (with the mast 6 as the common point of the angle) is approximately 45 degrees (See FIG. 3.) The height of the inner sail restraint 10 is greater than the distance from the horizontal arm 4 to boom 7 and the inner sail restraint 10 is therefore in position to restrain the rotation of boom 7 (and sail 8 ) when it approaches the horizontal arm 4 . An “outer sail restraint” 11 located between the mast 6 and the end of a horizontal arm 4 is secured to the horizontal arm 4 . The angle formed by the boom 7 (when it is in contact with the outer sail restraint 11 ,) the mast 6 and the horizontal arm 4 (with the mast 6 as the common point of the angle) is approximately 45 degrees (See FIG. 3.) The height of outer sail restraint 11 is greater than the distance from the horizontal arm 4 to boom 7 . The outer sail restraint 11 is therefore in position to restrain the rotation of boom 7 (and sail 8 ) when it approaches the horizontal arm 4 . The inner sail restraint 10 and the outer sail restraint 11 are secured to motorized sail restraint controllers 13 that are able to rotate the inner sail restraint 10 and outer sail restraint 11 to a horizontal position (as shown in FIG. 5.) A driving belt 14 is mounted at the lower end of the tower-collar 2 and drives a generator 15 to generate electricity. In other embodiments, conventional means such as a chain drive or direct gear drive is used in place of the belt drive 14 to drive the generator. In another embodiment the generator 15 may be mounted on the tower 1 below the tower-collar 2 .
[0020] [0020]FIG. 1 shows the device with four horizontal arms 4 and four sails 8 . In other embodiments the number of horizontal 4 arms and sails 8 may be as few as two, or greater than four.
[0021] Referring now to the drawing in FIG. 2 there is shown an overhead view of the present invention including the tower 1 , tower-collar 2 , one horizontal arm 4 , one mast-collar 5 , one boom 7 , one inner sail restraint 10 , and one outer sail restraint 11 . Additional horizontal arms are omitted to simplify the Figures. A sequence of nine Figures from FIG. 2-A to FIG. 2-I are shown. The sequence of Figures illustrate the action of the wind on the device. The arrow in FIG. 2-A indicates the direction of the wind and applies to all Figures. The Figures will illustrate the action of the wind on the device by following only a single boom 7 as it rotates 360 degrees around the device. It is of course understood that all the horizontal arms, booms, sail restraints and sails operate in the same fashion. In FIG. 2-A the boom 7 is in contact with the inner sail restraint 10 . The boom 7 is held in a position of approximately 45 degrees with respect to the horizontal arm 4 on which it is mounted and is in position to begin its rotation in the clockwise direction. In FIG. 2-B the horizontal arm 4 has rotated approximately 45 degrees, and the boom 7 is still restrained by the inner sail restraint 10 which keeps the sail fully faced into the wind, providing driving force for rotation. In FIG. 2-C the horizontal arm 4 has rotated an additional 45 degrees, and the boom 7 continues to be restrained by the inner sail restraint 10 . The position of the boom 7 facing obliquely into the wind continues to drive the horizontal arm 4 clockwise. In FIG. 2-D the horizontal arm 4 has rotated another 45 degrees, and the inner sail restraint 10 now forces the boom 7 (and sail, not shown) to point into the wind, making it vulnerable to an “uncontrolled gybe.” In Figure 2 -E the horizontal arm 4 is shown in the same position as in FIG. 2-D, and the boom 7 (and sail, not shown) is shown having undergone an “uncontrolled” gybe of approximately 90 degrees. The boom 7 however is then “caught” by the outer sail restraint 11 and the energy in the remaining 90 degrees of the gybe, (of a normal 180 degree gybe) is harvested in rotating the device. In FIG. 2-F the horizontal arm 4 has rotated another 45 degrees. The boom 7 is still restrained by the outer sail restraint 11 and is facing obliquely into the wind continuing to provide driving force for rotation. In FIG. 2-G the boom 7 is pointing downwind. It is now free of both the inner sail restraint 10 and outer sail restraint 11 and is feathered, offering little or no resistance to the wind, as the horizontal arm 4 rotates clockwise into the wind. Frame 2 -H is similar to FIG. 2-G except that the horizontal arm 4 has rotated another 45 degrees into the wind and the boom 7 is still feathered. In the last FIG. 2-I the horizontal arm 4 has brought the boom 7 which is still feathered, into position where it is about to contact the inner sail restraint 10 completing the cycle.
[0022] Returning once again to the drawing in FIG. 1 the sail 8 in the lower right corner of the FIG. 1, can now be understood as being in the position corresponding to the boom 7 (and sail) in FIG. 2-C, that is, it has been pushed by the wind approximately 90 degrees clockwise, but is not yet presenting its sail 8 directly into the wind for gybing. The sail 8 in the lower left corner of FIG. 1 corresponds to the boom 7 (and sail) position in FIG. 2-E that it, its sail has gybed and been caught by the outer sail restraint 11 . The sail 8 in the upper left corner of FIG. 1 corresponds to the sail position in FIG. 2-H that is, its boom 7 (and sail) is pointing downwind and is feathered, offering little or no resistance to the wind. The next sail 8 clockwise, in the upper right corner of FIG. 1, corresponds to FIG. 2-A that is, its boom 7 (and sail) is in contact with the inner sail restraint 10 and the sail 8 is in position to begin the cycle again.
[0023] Referring now to the drawing in FIG. 3 in detail, there is shown a cross sectional, overhead view of the present invention at the level of the horizontal arms 4 including the tower 1 , the tower-collar 2 , horizontal arms 4 , masts 6 , mast-collars, booms 7 , inner sail restraints 10 , and outer 11 sail restraints. The arrows indicate the direction of the wind and the device should be understood as rotating clockwise. In the upper right hand corner of FIG. 3 Angle A, formed by the boom 7 (lying against the inner sail restraint 10 ) the mast collar 5 (serving as the point of the angle) and the horizontal arm 4 , is substantially 45 degrees. The same is true for Angle A in the upper left hand corner of FIG. 3. In the lower right hand corner of FIG. 3, Angle B, formed by the boom 7 (lying against the outer sail restraint 11 ) and the horizontal arm 4 , is substantially 45 degrees. The same is true for Angle B in the lower left hand corner of FIG. 3. FIG. 3 also shows that during the part of the rotation cycle illustrated in the Figure the two sails on the right hand side of the Figure are both simultaneously capturing the energy of the wind ( as indicated by the arrows pointing to each of those two sails.) This is due to the gybe that has just taken place for the sail in the lower right corner. The gybe has moved the lower right hand sail to the outside position where it is restrained by the outer sail restraint 11 allowing the two sails to be driven simultaneously. It may also be noted that the sail in the upper right hand corner is not hindering the sail in the lower right hand position due to the gybe that has taken place.
[0024] Referring now to the drawing in FIG. 4 in detail, there is shown a cross sectional, overhead view of the present invention at the level of the horizontal arms 4 and the booms 7 . FIG. 4 shows the tower 1 , the tower-collar 2 , horizontal arms 4 , booms 7 , mast collars 5 , (masts are not shown) inner sail restraints 10 , outer sail restraints 11 , and motorized sail restraint controllers 13 . The inner sail restraints 10 and the outer sail restraints 11 are shown rotated into a horizontal position by the motorized sail restraint controllers 13 . In this position none of the sail restraints are able to restraint the booms 7 . Accordingly, wind from the direction shown by the arrows, causes each boom 7 (and the sail secured to it, not shown) to become feathered. The motorized sail restraint controllers 13 are operated during excessively high winds speeds to avoid damage to the device.
[0025] Referring now to the drawing in FIG. 5 there is shown a side view of the base of an alternative embodiment of the device, showing the generator 15 driving belt 14 tower 1 and tower-collar 2 . In addition, caster supports 25 are secured to the tower-collar 2 and casters 24 are secured to the caster supports 25 . This embodiment allows the tower-collar 2 to rotate around the tower 1 on casters 24 rather than on the thrust bearing 19 shown in FIG. 1.
[0026] Referring now to the drawing in FIG. 6 in detail, there is shown a side view of a single sail 8 of the present invention including a mast 6 , a mast-collar 5 , a boom 7 , and a sail frame 9 . In addition, FIG. 7 shows a means for reefing, or partially reefing, a sail during high winds. The reefing system consists of a remotely operated bi-directional motor 19 which is secured to the mast-collar 5 . A drive pulley 26 controls a reefing line 20 which extends around a free-wheeling pulley 21 mounted on the frame 9 . The reefing line 20 is attached to a batten post 27 which is secured to a batten 23 embedded in the sail 8 . The sail 8 is flexible and is suspended by sliding rings 22 secured to the frame 9 above and to the boom 7 below. To reef a sail, the bi-directional motor 19 is operated drawing the sail 8 horizontally toward the mast-collar 5 . To restore the sail 8 to its normal position the bi-directional motor 19 is operated drawing the sail away from the mast collar 5 . A sail may be completely reefed, held stationary in a partially reefed position, or kept in the normal unreefed, position by the appropriate operation of the bi-directional motor 19 . In FIG. 7 the sail 8 is shown held in a stationary, half-reefed, position. In another embodiment, the elements of the reefing system (bi-directional motor 19 , drive pulley 26 , reefing line 20 , free-wheeling pulley 21 , batten post 27 , batten 23 , and sliding rings 22 ) are rotated 90 degrees and the sail can then be reefed vertically, either upward or downward. Advertising, art, public interest notices, flags or other material of interest to the public 35 may be displayed as shown on sail 8 . The device may also be displayed simply as a work of art in itself.
[0027] Referring now to the drawing in FIG. 7 there is shown a side view of another embodiment of the device having two levels of horizontal arms 4 , one above the other secured to the tower-collar 2 ; the figure shows only one pair of horizontal arsm 4 , it being understood that one or more additional pairs of horizontal arms may be secured to the tower-collar 2 (not shown). The figure shows the tower 1 , tower-collar 2 , generator 15 , drive belt 14 , shaft collar 3 , thrust bearing 19 , inner sail restraints 10 , outer sail restraints 11 , masts 6 , mast-collars 5 , sails 8 , booms 7 , and frames 9 . The figure indicates that a sail 8 (and its mast 6 , mast-collar 5 , sail restraints 10 , and 11 , boom 7 and frame 9 ) may be mounted above as well as below a horizontal arm 4 . In addition, the figure indicates that two (or more) sails 8 (and their masts 6 , mast-collars 5 , sail restraints 10 , and 11 , booms 7 and frames 9 ) may be mounted along each horizontal arm 4 . In this figure the sails 8 should be understood having already gybed, are pushing their outer sail restaints 11 , and the device is rotating toward the reader.
[0028] Referring now to the drawing in FIG. 8, there is shown a perspective view of a section of a horizontal arm 4 of the device, housing an inner sail restraint 10 . The sail restraint 10 is shown in the vertical position in FIG. 8A, that is, in the position used during rotation of the device by wind power. The sail restraint 10 is held in the vertical position by means of a first cable 32 pulled in the direction shown by the arrow. The first cable 32 is secured to a first post 28 . A first stop 30 limits the excursion of the sail restraint 10 to the vertical position when the first cable 32 is pulled. FIG. 8B shows the sail restraint 10 oriented in the horizontal position for, after being pulled to the horizontal position by a second cable 33 pulled in the direction shown by the arrow. The second cable 33 is secured to a second post 29 . A second stop 31 limits the excursion of the sail restraint 10 to a horizontal position when the feathering cable 33 is pulled. The outer sail restraint (not shown) is controlled in the same way.
[0029] Referring now to the drawing in FIG. 9 there is shown a cross sectional, overhead view of another embodiment of the device at the level of the horizontal arms 4 and booms 7 showing the tower 1 , tower-collar 2 , mast 6 , mast-collar 5 , motorized sail restraint controllers 13 , inner sail restraints 10 and outer sail restraints 11 . The horizontal arm 4 in the 3 o'clock position has its inner sail restraint 10 mounted on the boom 7 , rather than on the horizontal arm 4 . The inner sail restraint 10 restrains the boom 7 (and sail, not shown) in the same way as it would if mounted on the horizontal arm 4 , that is, it positions the boom 7 for an early gybe. The horizontal arm 4 in the 6 o'clock position has its outer sail restraint 11 mounted on the opposite side of the boom 7 rather than on the horizontal arm 4 . The outer sail restraint 11 restrains the boom 7 (and sail, not shown) in the same way as it would if mounted on the horizontal arm 4 , that is, it “catches” the boom 7 after its early gybe and allows gybe energy to add to the rotation of the device. The horizontal arms 4 in the 9 o'clock and 12 o'clock positions have their inner sail restraints 10 and outer sail restraints 11 rotated to the horizontal position for feathering by the motorized sail restraint controllers 13 mounted on the booms 7 .
[0030] In an another embodiment, the device is used as a display device, in which the sails contain commercial advertising, public service messages, flags, art work or other material of interest to the public.
[0031] In another embodiment, the device is displayed as a work of art.
[0032] The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. Accordingly, reference should be made to the appended claims rather than to the foregoing specifications as indicating the scope of the invention. | A device for generating electricity in which wind blowing from any direction causes the rotation of sails around a vertical tower. As the sails rotate the sails moving toward the wind are automatically feathered, and the sails moving away from the direction of the wind are prevented from being feathered by sail restraints. An inner sail restraint positions each sail so that the sail gybes at an earlier time than would otherwise occur. An outer sail restraint “catches” the sail as it gybes, capturing much of the energy of the gybe, adding additional rotational force. The device may be used to extract energy from the wind to produce electricity. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This claims the benefit of U.S. Provisional Patent Application No. 62/058,303 entitled “Pen Front” filed Oct. 1, 2014, the entire disclosure of which is hereby incorporated by reference for all purposes.
STATEMENT CONCERNING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable.
FIELD OF THE INVENTION
[0003] This invention relates to a molded plastic front panel containing a door for an animal pen confinement system.
BACKGROUND OF THE INVENTION
[0004] Livestock confinement pens such as those disclosed in U.S. Pat. No. 8,186,306 and commercially available from L. T. Hampel Corporation have attained widespread usage and are well known. Such pens are made from multiple generally planar panels that are molded plastic and fit together at the corners to create a single free-standing pen or a system containing any number of pens side-to-side and/or back-to-back in generally a grid pattern. The panels are generally hollow and made by vacuum thermoforming, rotational molding, blow molding, or similar processes.
[0005] The front panel of such pens is pinned at the corners to the side panels or provided with other fastening means and contains a door that is hinged at one edge and latched to the front panel at the opposite edge. The door may contain an integrated feeding system that holds buckets of feed and water, or possibly a bottle to feed younger animals. These pens must be structurally sound, easy to set up and take down, easy to remove to clean the floor on which they stand, easy to clean, and must provide effective containment of a variety of animals.
[0006] In addition, the human user of the pen system may like to set up the pen in a variety of ways, depending upon their operation. Another important aspect of the pens and particularly the raising of young animals like calves is preventing contact between animals in neighboring pens, as such contact promotes the spread of disease. The pen should also function to inhibit cross-contamination of the feed and water that are provided in the pen door.
SUMMARY OF THE INVENTION
[0007] The invention in one aspect allows for multiple operating positions for the door in the front panel without the need for secondary or add-on hinges to be attached to the door or door jamb. Incorporating multiple integrated interlocking knuckle locations, which are connected together by a hinge pin passing through the knuckles on the door and jamb, allows for the closing of the opening. Other integrated features allow for a choice of feed opening sizes and also an option for a guard that minimizes feed and water contamination.
[0008] The invention also provides a design for an animal pen confinement front with a door with integrated left and right knuckles that interdigitate with corresponding hinge knuckles on the corresponding left or right side of the door jamb so the door can be hinged to the jamb from either the left or right side. The door can also swing either inward or outward. A door stop to facilitate latching of the door can be provided that creates a consistent door stop. In one form this can allow the upper section of a latching mechanism to pin into the frame and lock onto the door. In addition, this allows the lower section of the locking mechanism to securely pin the door and frame together at the bottom of the door to prevent the door from swinging in the door open direction. It also stops the door in the door closing direction when it is latched and makes it easier to find the holes in the door jamb for latching the door to the jamb.
[0009] The door stop stops the door in the door closing direction in the closed position of the door to help align the latch with the door or frame. The door stop(s) may be detachable and reversible to be assembled in any of four positions so the door may be hinged left or right, and may swing in or out, using the same door stop(s) for each of the four configurations.
[0010] In addition, a pail cross-over guard with an integrated snap-in feature that requires no mechanical fasteners prevents the animal within the pen from feeding and drinking from a single feed opening. This minimizes contamination of materials between the buckets, to keep the water more free of feed and the feed more dry.
[0011] In addition, an integrated feed opening restrictor provides for enlarging the feed open area by the user to accommodate larger animals that need a larger feed opening. When present, the restrictor keeps smaller animals from exiting the pen through the feed opening. This provides the ability to keep smaller animals inside the pen and easy modification of the pen to accommodate larger animals that need a larger feed opening by removing the restrictor.
[0012] Preferably, both sides of the door and jamb have cooperating latch and catch mounts, stop mounts that provide clearance with the door, alignable hinge holes and a spacer movable to either hinged side of the door that creates a clearance between the door and jamb as the door swings.
[0013] The foregoing and other objects and advantages of the invention will appear in the detailed description which follows. In the description, reference is made to the accompanying drawings which illustrate a preferred embodiment of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a perspective view of two side-by-side pens with the pen on the left set up with the door opening inward and the pen on the right having the door opening outward;
[0015] FIG. 2 is a top plan view of the pens of FIG. 1 ;
[0016] FIG. 3 is a perspective view of one of the pen fronts of FIGS. 1 and 2 shown alone and with a pail cross-over guard shown exploded off from the door;
[0017] FIG. 4 is a detail perspective view of a portion of FIG. 3 ;
[0018] FIG. 5 is a cross-sectional view showing the cross-over guard assembled to the door;
[0019] FIG. 6 is a front plan view of the pen front with a feed restrictor shown in the feed opening on the right and the opening on the left shown without a feed restrictor;
[0020] FIG. 7 is a view like FIG. 6 with both feed restrictors removed;
[0021] FIG. 8 is a perspective view illustrating a door stop assembled to the pen front in a position to stop a door that opens outwardly (closes inwardly);
[0022] FIG. 9 is a view showing the door stop as it would be assembled to the opposite side of the pen front and with the door stop exploded off from the pen front panel;
[0023] FIG. 10 is a view showing the top part of the door latch;
[0024] FIG. 11 is a plan view of the pen front showing how the door latch rod extends through the door with a top leg extending through the door jamb and a bottom end extending into the bottom of the door jamb and showing on the opposite side the hinge rod with its short end disengaged from the door;
[0025] FIG. 12 is a view like FIG. 1 but of a second embodiment of the invention, shown with the doors closed;
[0026] FIG. 13 is a view like FIG. 12 with the left door hinged at the right side and opening inward and the right door hinged at the left side and opening outward;
[0027] FIG. 14 is a top plan view of the second embodiment as shown in FIG. 12 ;
[0028] FIG. 15 is a top plan view of the second embodiment as shown in FIG. 13 ;
[0029] FIG. 16 is a front plan view of the second embodiment;
[0030] FIG. 17 is a rear plan view of the second embodiment;
[0031] FIG. 18 is a left side plan view of the second embodiment; and
[0032] FIG. 19 is a right side plan view of the second embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0033] Referring to FIGS. 1 and 2 , each pen 10 is defined by four panels 12 , 12 , 14 and 16 , with the side panel 12 between the two adjacent pens 10 shared. Thus, each pen 10 has two side panels 12 , a rear panel 14 , and a front panel 16 . The panels are secured to one another at the corners by a rod that extends through interdigitating knuckles of the panels in the manner as described in U.S. Pat. No. 8,186,306, which is hereby incorporated by reference for all purposes. The front panel 16 may also have a steel reinforcement incorporated inside of it as described in U.S. Pat. No. 8,186,306.
[0034] Each front panel 16 includes a frame portion or door jamb 18 and a door or gate 20 . Each side of the jamb 18 is molded with knuckles 19 and each side of the door 20 is molded with corresponding knuckles 21 that interdigitate with the knuckles 19 molded into the jamb on the same side so that on one side or the other of the jamb a hinge rod 27 can be inserted through holes in the sets of knuckles 19 , 21 to extend vertically down through the sets of interdigitating knuckles to create a hinge joint between the door 20 and the jamb 18 , on one side or the other. Therefore, the door may be hinged on either the right or the left side. Holes may be provided on both sides of the door and jamb so that the user who assembles the front panel 16 can determine which side to hinge the door to. The hinge rod is J shaped and its short end at the top of the rod is received in a hole at 23 at the top of the door 20 with its long end received in a series of holes down through the knuckles at 44 . There is a hole at 23 on both the left and the right of the door. The hole at 23 is used by the latch rod if the latch is installed on that side and is used by the hinge rod on the hinged side of the door. The side the door is not hinged to is the latch side with the latch rod 30 described below, which uses the top hole at 23 in the door on that side. The short end of the latch rod 30 uses the top hole at 44 also. Thereby, sets of holes are provided on both sides of the door and jamb, and both the hinge rod and the latching rod use some of the same holes on opposite sides.
[0035] Once hinged, a door stop 22 ( FIGS. 1 , 6 , 7 , 8 , 9 , and 11 ) is assembled to the door jamb 18 by using screws in the correct position. The door stop 22 helps stop the door in the closed position where the latch rod can be lined up to engage the latch holes in the jamb. Alternatively, the door stop could be fastened to the door. The door stop 22 may be, for example, a piece of galvanized steel and is bent in the shape of a dog leg. It has any of four positions, two positions (inside or outside) on each side of the door opening of the jamb. It may be screwed to the jamb either from the outside of the jamb or from the inside of the jamb. If screwed on the outside of the jamb, the door will open outwardly, and if screwed on the inside of the jamb, the door will open inwardly. As stated earlier, the four positions would be left inward or outward and right inward or outward. The door stop 22 is in all four positions received in a recess in the door jamb and is screwed to a web of plastic 24 that spans the recess. The part of the door stop that does not have mounting holes and extends upwardly is received in a recess of the door that is spanned by a web of plastic 26 ( FIG. 7 ).
[0036] When the door 20 is closed against the stop 22 , a latching mechanism 30 is employed that locks the door shut to the door jamb 18 . Referring to FIG. 11 , as described in part above, the latching mechanism 30 includes an upside-down J-shaped latching rod 32 . The rod 32 has a U-shaped keeper 34 welded or otherwise affixed to it. The rod 32 may be steel and the keeper 34 may be sheet steel. The rod 32 has a long end 36 , a cross run 38 to which the keeper 34 is attached, and a short end 40 . In the position shown in FIG. 11 , the lower end of the long end 36 extends into a hole in the bottom part of the jamb 18 at 42 and the short end 40 extends into the hole at 44 in the top of the jamb 18 . The long end 36 extends through the door 20 for substantially its full height and is guided therein by the door 20 . Guides may be molded into the door 20 , or the entry and exit holes provided at the top and bottom of the door 20 for the long end 36 may be adequate in themselves. In the position shown in FIG. 11 , the U-shaped keeper 34 extends down and overlaps both sides of the door 20 , so that the door 20 is between the vertical sides of the keeper 34 . This forms a U-shaped yoke that cradles the top of the door and keeps the rod 32 from rotating substantially relative to the door 20 so that the short end 40 is fixed to the door 20 to keep it from swinging in or out when the latch is secured. The keeper 34 also provides a handle to lift the latching rod 32 and open or close the door.
[0037] When it is desired to open the door 20 , the user grabs the keeper 34 , lifts it until the end of the short end 40 clears the top of the jamb 18 which is at about the same point that the bottom of the long end 36 clears the hole 42 in the jamb. The user is then free to open the door either inward or outward, depending upon where the door stop 22 is assembled, either on the inside of the door or on the outside of the door.
[0038] Referring particularly to FIGS. 3-5 , a cross-over guard 50 is provided that snaps into holes 52 in the door 20 . It is also hollow plastic and may be molded using methods similar to the methods used to mold the panels. No mechanical fasteners are required to attach the guard 50 to the door 20 . The guard 50 has studs 54 molded integrally with it that have ears 56 on opposite sides that snap into the holes 52 and resist removal of the guard 50 from the holes 52 . When installed, the cross-over guard prevents an animal from feeding and drinking from a single feed opening in the door, which minimizes water contamination when moving from the feed pail to the water pail and keeps the food more dry when moving in the opposite direction. As shown in FIGS. 4 and 5 , the holes 52 may be molded with an axially-facing shoulder 58 that catches on the back of the ears 56 to retain the guard 50 to the door 20 .
[0039] Referring to FIG. 6 , the door 20 is illustrated on the right side feed opening with a feed opening restrictor 60 . The restrictor 60 is molded into the door 20 and when present, restricts the size of the feed opening so smaller animals, like small calves or goats, cannot exit the pen through the feed opening. For larger animals, like older calves, that may require a larger feed opening, the restrictor 60 is cut along its outside edges so that the opening looks like the left-hand side opening shown in FIG. 6 . When new and delivered, the restrictor would be in both openings as is shown on the right side and after both restrictors are cut out, both openings would look like the opening on the left in FIG. 6 . The area of the cut is preferably pinched off and welded so the two sides of the panel are welded together in that area, with no space between them. That creates a single edge of a single thickness with no hollow space between the two sides of the door when the cut is made.
[0040] Thus, in one aspect, the invention provides a molded plastic pen front in which both sides of the door and door jamb are provided with interdigitating knuckles through which a rod may be inserted so that the hinge is on either side of the door. The hinge rod may be J-shaped with the long part of the rod extending through the knuckles and the short free end of the rod extending into a hole in the upper side or surface edge of the door. Preferably, the same sets of holes, or at least some of them, are used for the hinge rod and the latching rod, on opposite sides of the door. In addition, a door stop may be provided having any of multiple positions so that the same door stop can be used regardless of which side of the door is hinged to the door jamb and the door stop may be used regardless of whether the door is configured to swing in or swing out. The latching mechanism includes a J-shaped latching rod that secures the door both at the top and at the bottom. The rod may include a U-shaped keeper that extends on both sides of the front so that the rod is substantially restrained against pivoting when the latching rod is latched. In addition, the feed openings in the pen front may be provided with a restrictor that keeps small animals from exiting the pen through the feed opening, but can be removed to accommodate larger animals for feeding. In addition, the pen front preferably includes a cross-over guard that can be snapped in to prevent an animal from accessing two buckets from one opening.
[0041] Modifications will occur to persons of ordinary skill in the art that still incorporate the invention. For example, the U-channel keeper 34 that latches the door 20 could be integrally molded or attached to the top of the door 20 rather than mounted to the J-rod 30 . Such a configuration would help hold the rod 30 from rotating relative to the door 20 to reduce play in the latching of the door and may be preferable, particularly if molded in. It would also be possible to eliminate the door stop, allowing the door to swing either way, albeit it would make it more difficult to find the upper and lower holes to latch the door. It is also not necessary to have the door stop be doglegged or in recesses.
[0042] Another embodiment 116 of a 6-way pen front panel is shown in FIGS. 12-19 . Similar elements are labeled in the pen 110 with the same reference number as in the first embodiment 10 , plus 100 .
[0043] The six ways the door 120 (or door 20 ) can be configured are:
1) Left hinged, swings out 2) Left hinged, swings in 3) Left hinged, swings in or out. 4) Right hinged, swings out 5) Right hinged, swings in 6) Right hinged, swings in or out.
[0050] In the pen front 116 , there are two door stops 122 on the side of the jamb that opens that are reversible or can be left off to provide the six ways. Illustrated are two reversible stops on either the right of the jamb 118 (right pen in FIG. 12 ) or the left of the jamb 118 (left pen in FIG. 12 ). The dog-leg-shaped stops 122 , secured with a screw or bolt along one edge of the jamb, are reversed between the inner or the outer surface of the web 124 to change the door from swinging in to swinging out, and are removed to permit the door to swing both ways. If the stops 122 are removed, the pivoting latch handle 150 positions and secures the door, latching into a channel-shaped receiver catch 152 affixed to the door. The rotary latch handle 150 and its accompanying receiver 152 stops the door from swinging in or out if the door stops are removed or the door is set to swing either in or out only. The handle 150 is secured in a recess 154 of the jamb with a fastener (e.g., a bolt or screw, to swing about the axis of the bolt), and there is one recess 154 provided on each side of the jamb for the purpose of mounting the handle 150 . A J-shaped rod 127 extends through the interdigitating two knuckles 121 of the door and three knuckles 119 of the jamb, on the left side or right side, to provide the hinge axis for the door 120 . The two knuckles 121 on the opposite side of the door are received in the open spaces at the edge of the web 124 and each abuts a stop 122 , so the knuckle is bordered on four sides (top, bottom, inside and free end), providing additional stability.
[0051] The door stops 122 and handle 150 may be thermoformed plastic and the catch channel 152 may be formed of metal. The webs of plastic 124 form recesses at each of the four locations per pen front where a stop 122 may be fastened with a screw or bolt. These webs of plastic are recessed inwardly from the front surface and also are recessed outwardly, either rightwardly or leftwardly, from the inner edge of the jamb 119 to create an open space between the free edge of the web 124 and the free inner edge of the jamb 118 . This allows the door knuckles 121 on the hinged side of the door 120 to extend into that space and be engaged by the J-shaped hinge rod 127 to create the hinge of the door 120 to the jamb 118 . Also, those spaces on the opposite side let the knuckles 121 swing through them so the door can open both ways if no stop 122 is present, and can be made to open one way or the other with selective assembly of the stop 122 on either the inner or the outer side of the web 124 . Recessed mounting pads 158 are also provided at each of the two locations per panel 116 at which a catch 152 can be fastened with fasteners such as screws or bolts.
[0052] With the knuckled configuration of the door, there are many ways that reversible/removable stops can be attached or utilized. Making the door with knuckles permits each tab to function as either a hinge knuckle or one of the two required components of a stop. The reversible and removable stops could be affixed to either the jamb or to the door. Also, a different number of knuckles, e.g., three or four, could be provided along each edge of the door instead of two as in the illustrated embodiment, with corresponding knuckles in the jamb and each edge of the door and jamb need not necessarily have the same number of knuckles.
[0053] Although not illustrated, a pail cross-over guard could also be incorporated into the pen front 116 . A construction could be provided whereby the guard could be attached to the door between the feed openings with fasteners such as screws or bolts.
[0054] In addition, shouldered spacer bushings 160 can be provided between the hinge rod 127 and the holes in the jamb 118 through which the rod 127 extends. Each bushing spacer 160 is shouldered, being mushroom shaped with an enlarged head that resides between the bottom side of each knuckle 160 and the jamb 118 and a shank that extends from the head into the adjacent hole in the jamb 118 with the rod 127 inside the hole that runs through the bushing 160 , The shoulder is therefore between the head and the shank. The spacers 160 are moveable to the chosen hinged side of the door, either right or left of the door, and raise the hinged side of the door so that the door clears the frame as it swings.
[0055] Preferred embodiments of the invention have been described in considerable detail. Many modifications and variations to the preferred embodiments described will be apparent to a person of ordinary skill in the art. Therefore, the invention should not be limited to the embodiments described. | A generally hollow plastic molded pen front provides multiple operating positions of the door having sets of interdigitating hinge knuckles on the door and door jamb on both the left and right side. The door also may be swung in or out, and one or more stops can be provided for any of four configurations—left hinged swing in; left hinged swing out; right hinged swing in; right hinged swing out. With the stops removed, the door may be swung both in and out. In one embodiment a J-shaped latching rod secures both the upper and lower portions of the door when latched and a J-shaped hinge rod cooperates on the other side and can use some of the same holes as the latching rod. In another embodiment, a pivoting handle works to secure the door in a catch channel for all six configurations. Other integrated features provide a choice of feed opening sizes and a guard that minimizes feed and water contamination. | 4 |
FIELD OF THE INVENTION
The present invention relates to a spreadable food product with a low fat content or which is free from added fat.
BACKGROUND OF THE INVENTION
There is still presently a strong wish to have available on the market spreadable food products to be used as substitutes for butter, margarine or other similar fat spreads, and having a low level of fat so as to reduce the caloric content thereof, or for other dietetic considerations.
Spreads are already known in which the fat has been partially replaced by other products such as proteins, gelatin, hydrolysed or modified starches and/or maltodextrin, etc, as disclosed for example in EP-A-237120 and WO 93/17565.
However, none of these known available low fat spreads is really satisfying for the consumer, since they may have unusual flavour, taste, texture, consistency, appearance or mouthfeel (as being for example somewhat grainy), and are not sufficiently heat resistant. Furthermore, some of these known spreads involve a manufacturing method which is relatively complex or too expensive to carry out.
On the other hand, a new fat replacer, food grade texture agent, has been developed by the same applicant, which is described in the International application WO 96/03057, and which is consisting in microparticulate high amylose starch, and more particularly in thermally stabilized swelling resistant and non crystalline particles of high amylose starch, in which the amylose content of the starch is of 40 to 70%, and in which 90% of the particles have a diameter in the range of 5 to 30 microns.
SUMMARY OF THE INVENTION
The present inventors have now unexpectedly found that said microparticulate high amylose starch can advantageously be used also for preparing a high quality spreadable product of low fat level and even a fat free product, which includes all the required features defined above and which are not presented by the prior known low fat spreads referred above, especially as being pasteurizable or heat resistant (to temperatures higher than about 65° C.).
Accordingly, the object of the present invention is consisting in a water-continuous low fat spreadable food product having from 0 to 30 wt % fat and which comprises from 4 to 30 wt % of thermally stabilized non crystalline particles of high amylose starch having a diameter in the range of 5 to 30 microns.
Preferably, the spread according to the invention contains from 0 to 10% of fat, and the average diameter of the starch particles is of 10 to 20 microns.
Furthermore, the product according to the invention may contain a water-soluble gel-forming polysaccharide, for example from 5 to 20 wt % of low DE gelling hydrolysed starch, such as maltodextrin.
According to a further embodiment, the spread according to the invention may further contain other gelling and/or thickening agents, and optionally food colours, edible surfactants, lipids, flavouring and/or preservative agents, etc, the rest being essentially water.
Regarding to the particulate high amylose starch, whose amylose content is higher than about 40%, it can preferably be obtained as described in the above-mentioned International application WO 96/03057. Such preparation process comprises the steps of suspending the high amylose starch in water (approximatively 4 volumes of water), heating and mixing the slurry (starch suspension) first at about 90 to 100° C., preferably 95-100° C., under continuous controlled stirring to avoid particle aggregation and so as to form the aimed particle gel product, and then cooling said product. The stirring must effectively be such that a too high shearing which could destroy the particles is avoided, but its efficiency has to be sufficient to avoid particles aggregation during the heat treatment so as to reach the stabilization of the particle structure. Preferably, the process includes a second heating step up to 40 to 80° C., and it can be advantageously carried out under a pressure of about 0.3 bar. Each step of this process can be of at least 10 min; as an example, it can have the steps of first heating upto 95-100° for about 30 min, maintaining said temperature during about 30 min, cooling slowly the product obtained up to room temperature (20-30° C.) within about 25 min, further heating said product up to 40-80° C. (about 60° C.) within about 15 min, and cooling it again within about 5 min to room temperature.
The particulate product thus obtained is in the form of grains having a gelled soft structure, which retained in fact the non crystalline structure of the starting starch used. The particles have not been chemically modified nor altered by the controlled thermal and mechanical treatment, and have proven to be resistant to shearing, heating (up to 125° C.) and acid, as well as swelling resistant, for example in aqueous medium up to 120° C. The average diameter of the particle is of about 15-17μ, whereas the particles size distribution is such that about 90% of the particles have a diameter in the range of about 5 to 30μ.
The thick slurry obtained (tridimensional particles gel network in water) can be directly used as such, or preferably after spray-drying in a mixture with 0.5 to 1.0 wt equivalent of (malto)dextrin (DE 6-12).
As starting product for the preparation of the aimed particular starch, different kinds of native high amylose starch can be used, for example "Eurylon VII" (from Roquette, Lestrem, France) containing 70% amylose and "Amaizo 2568F" (American Maize Product CO., Hammond, Ind., USA) containing 45-50% of amylose.
The maltodextrin which is usable in the product according to the invention as gelling hydrolysed starch will have a low DE value, for example less than 12, and preferably from 1 to 6.
As already mentioned, the low fat spread according to the invention may further contain other thickening or gelling agents in order to adjust the viscosity of the product, such as waxy maize starch, pectin, carrogeenan, xanthan, alginate, etc.
Although not being particularly preferred, the spread may also contain other ingredients, such as flavouring agents (for example butter flavour), preservatives (for example potassium sorbate), salt (e.g. sodium chloride), acidifiers (e.g. lactic acid), vitamins, food colouring products, edible surfactants, lipids, etc. It is to be however pointed out that caution should be taken to avoid ingredients which may alter the taste or flavour of the final low fat spread for the consumer.
As fat which can be used in the present invention, any kind of conventional edible fat, such as cream, any emulsified vegetable fat (soya, canolla, peanut, etc).
DETAILED DESCRIPTION OF THE INVENTION
The invention will now be illustrated by the following Examples.
EXAMPLE 1 Free Fat Spread
______________________________________Composition (wt %)______________________________________A. Maltodextrin ("Snowflake 1906") 15 Waxy maize starch ("WDC 1001") 1.5 Salt 0.05 Sodium benzoate 0.05 Potassium sorbate 0.05 Lactic acid 0.25 Water 75B*. Particulate high amylose starch 4 Dextrin (DE 10)______________________________________ 4 (*= mixture 1:1 of spraydried high amylose starch particles and dextrin).
A "margarine-type" product was first prepared by mixing all the ingredients A in water at 50° C.; the mixture was heated to about 100° C. and mixed with a "Polytron" homogenizer. Then product B was added and gently mixed to homogeneity. The mix was cooled down to about 6° C. and kept overnight to obtain the desired texture.
Peak force (=resistance to penetration of a flat probe) was measured using a "TA-XT2" Texture Analyser (of Texture Technologies Co) equipped with a 2.5 cm diameter flat metal probe. The peak force was measured (at 6 and 20° C.) by inserting the probe to constant depth (2 mm) at a constant speed (1 mm/sec) on spread samples after storage at 6° C. for 1 day. The results obtained by measurements made half a day later were the following:
peak force: 2.7 N (6° C.) and 2.5 N (20° C.)
EXAMPLE 2 Reduced Fat Spreads (20%)
______________________________________Compositions (wt %) I II______________________________________ Fresh cream (35% fat) 57.0 57.0 Particulate high amylose starch 18.3 8.3 Dextrin (DE10) 4.2 9.2 Maltodextrin ("Snowflakes 1906) 5.0 15.0 Water 15.5______________________________________ 15.5 (*= mixture ca. 1:0.5 of spraydried high amylose starch particles and dextrin)
Water was first added to cream and heated about 60° C.; the other components were then slowly added under mixing, and the respective mixtures cooled down at refrigeration temperature.
Peak force measurements carried out as in Example 1 gave the following results:
peak force:
I 3.4 N (6° C.) and 1.8 N (20° C.)
II 2.6 N (6° C.) and 1.6 N (20° C.)
As a comparison, the peak force of 40% margarine is of 1.6 N at 20° C. and of about 10 N at 6° C. This means that at low temperatures the spreads according to the present invention can be more easily applied for example on bread. Furthermore, the above results of the peak force measurements indicate that the influence of the temperature on the spreadability of the food products according to this invention is much less than in the case of margarine type products.
EXAMPLE 3
Low Fat Spread Cream
A low fat spread cream and a usual spread cream (as reference) have been prepared with the following respective compositions:
______________________________________ Low fat (wt %) Reference (wt %)______________________________________A. Gelatin 1.6 1.6 Maltodextrin (DE 12) 12 Particulate high amylose starch -- 16 Sodium sorbate 0.08 Sodium chloride 1.4 Water 44.867.2B. Soya oil 32 Soya fat 81 Emulsifier 0.5______________________________________ (Dimodan P ® from Danisco)
Mixtures A and B have been heated separately to about 85° C. for 5 min. and cooled down to about 60° C. Solution A has been then added slowly to solution B in a waring blender, and the emulsion thus obtained cooled down and stored 5 days at about 4° C.
The two creams obtained as described above are similarly onctuous, shiny and with good spreadability, but the respective energy contents thereof are very different, since it is of 419 kcal for the reference cream and only of 147 kcal for the cream according to the invention.
As a separate experiment, a spray-dried high amylose starch, of the type used in the present invention, was suspended in water and heated at about 85° C. for 10 min. A subsequent microscopic examination of the suspension revealed that starch granules are loosely associated together, and no significant increase in aggregation was noticeable after the heating. Also, the average particle size of the suspended high amylose starch measured by laser light scattering did not indicate a volume increase of the granules after said heating.
It has further been stated that the fat free, respectively low fat, spreads described above present sensorial and textural properties (mouthfeel consistency) which can be quite comparable to those of standard butter.
Finally and thanks to the solid state of the small gel granules of high amylose starch used in the present invention, the rheological properties of the free fat or low fat spread according to this invention can be more easily and precisely controlled than according to the known methods. The thermal stability of the microparticulate high amylose starch used further makes the system sterilization easier, as well as the preparation process of the spread as a whole, and increases the structural stability of the spreadable product. | A low fat spreadable food product is disclosed which is usable as a butter replacer and has from 0 to about 30 wt. % fat. The product contains from 4 to 30 wt. % of thermally stabilized non crystalline particles of high amylose starch having a diameter in the range of 5 to 30 microns. | 0 |
DESCRIPTION OF THE INVENTION
This invention relates to a new variety of Malus hupehensis tree, commonly referred to as the flowering tea crab.
My new Malus hupehensis is one of a large number of ornamental trees which I have developed during many years of effort, and of which the flowering crab is a well known example.
The colorful tree of my new variety is one particularly selected from a row of seedlings of Malus hupehensis `Strawberry Parfait`, U.S. Plant Pat. No. 4,632×Malus `Crimson Cloud` an unpatented variety of my development.
My new tree is comparable in height and spread to Malus `Strawberry Parfait` but it is more densely branched. The branch crotch angles are wide, approximately 90 degrees on the average. The tree is lower growing and more spreading than Crimson Cloud` and less densely branched than that variety. It is more flat topped than `Crimson Cloud` which forms a large rounded crown.
It may be noted that Malus `Crimson Cloud` is a hybrid between Malus baccata and Malus `Almey`, neither patented, the latter itself a hybrid crab apple.
My new variety might desirably be called a hybrid crab apple, but it resembles Malus hupehensis in two important respects, it has the same spreading habit of growth with a flat top and it has the same extremely high resistance to apple scab disease and mildew. This aspect was particularly striking during the spring and summer of 1988 when almost all crab apples defoliated badly with the exception of Malus hupehensis and its hybrid progeny. The botanical name by which I have chosen to designate `Cardinal` may be thought to be arbitrary, but its performance is the best of the red flowered crab apples in any event.
I point out that the blooms of my new variety are slightly larger, about 4.5 cm in diameter when fully expanded, than `Strawberry Parfait`, which is about 4.2 cm in diameter, and slightly smaller than `Crimson Cloud` which may be 4.7 to 4.8 cm in diameter.
My new variety `Cardinal` bears four to five fruits per spur in contrast to Malus `Strawberry Parfait` which bears five to six fruits per spur and Malus `Crimson Cloud` which bears three to four fruits per spur.
To define the distinctions between the several varieties herein referred to, it is noted that the fruit crop of Malus `Strawberry Parfait` is abundant and showy. The color is vivid red 5R 5/13. `Cardinal` is a less showy and abundant fruiter and the color is deeper, strong red 5R 4/12.
The fruit size of `Cardinal` is larger than `Strawberry Parfait` about 1 cm deep and 1.5 cm wide. `Strawberry Parfait` is about 1 cm deep and 1 cm wide. The wild type of Malus hupehensis bears abundant but not conspicuous fruits.
Having been selected by me, I noted that as the tree matures it becomes more outstanding for its abundant bright red flowers and small, very glossy red fruits.
I have been able to select new varieties of Malus hupehensis because of the fact that, in the nursery to which I have access near Princeton, N.J., there are large numbers of such trees growing as well as many other ornamental trees of different species. The fact is that there many other ornamental trees also grown in the nursery and I am particularly watchful for the occurrence of new varieties of all kinds which provide desirable display and growth characteristics.
As a result of the observations conducted, I note that those previously mentioned aspects have been displayed even in very humid summers in New Jersey, during which my new variety here being described, did not exhibit defoliation or leaf injury from apple scab fungus, even though sibling seedlings showed severe defoliation.
In addition, an important commercial aspect of my new variety, is the rapid growth rate and the wide spreading crown.
I have established that the foregoing generally described characteristics and those specifically enumerated, continue from generation to generation created by asexual reproduction effected by bud grafting carried on near Plainsboro, N.J.
Further details of my new variety, which I have chosen to identify for commercial purposes as `Cardinal`, are set forth in the following detailed summary, as shown in the drawing wherein a tree of the new variety is shown in color as nearly representative of the actual tree, as it is possible to provide by photographic process.
The second sheet of drawings shows a portion of a branch of my new variety in larger detail.
The color notations are selected from the Nickerson Color Fan of Munsell Color Company and reflect the observations made in ordinary daylight conditions.
DETAILED DESCRIPTION OF THE INVENTION
Parentage:
Seed parent.--Malus hupehensis `Strawberry Parfait` U.S. Plant Pat. No. 4,632.
Pollen parent.--Malus `Crimson Cloud ` (unpatented).
Tree: Medium height, about 5.18 meters, widespreading; commonly to a width of 9.75 meters; dense and hardy.
Trunk.--Stocky and smooth. Diameter 12.18 cm.
Branches.--Slender and smooth; begin about 1.32 meters above ground. Color -- Dark grayish purple. Lenticels -- Sparse; number -- 4 to 5 per cm of twig.
Bark.--Smooth and brownish gray 10YR 3/1 in color.
Leaves:
Quantity.--Moderately abundant.
Length.--8 to 9 cm.
Width.--3 to 3.5 cm.
Shape.--Narrow ovate.
Color.--When expanding -- Moderate reddish brown, 7.5R 3/6. Summer -- Dark red 2.5R 3/1.
Thick.--Not susceptible to apple scab fungus or mildew.
Stipules.--2 cm long -- drop when foliage and twigs mature.
Margin.--Serrate.
Petiole.--Medium 3 to 4 cm long.
Glands.--None.
Flower buds:
Hardiness.--Very cold hardy.
Size.--0.5 cm long, 0.2 cm wide.
Shape.--Minute, ovate.
Color.--Dark purple.
Flowers:
Dates first bloom.--April 27.
Full bloom.--May 4. Considered mid-season regular bloomer in New Jersey, about the same time as Malus `Strawberry Parfait` and seven to ten days later than `Crimson Cloud`.
Quantity.--Very abundant.
Size.--Large. 4.5 cm diameter when fully expanded.
Color.--Strong red 5R4/10, fading to moderate red 2.5R 4/10 when fully opened.
Petalage:
Number of petals.--5.
Shape of petals.--Rounded, slightly notched at end.
Size of petals.--Length 2 cm, width 1.6 cm.
Color.--Moderate red, 2.5R 4/10.
Fruits:
When borne.--September, October.
Abundance.--Moderately abundant, glossy.
Seed cells.--Average two to five per fruit; mature seeds moderate reddish brown 2.5YR 3/3.
Size.--1 cm deep, 1.5 cm wide.
Color.--Strong red 5R 4/12. | A Malus hupehensis tree providing abundant red flowers and small, very glossy red fruits, having resistance to defoliation in hot humid summers and to leaf injury from apple scab fungus or mildew which severely affects other similar trees in an adjacent area, the tree growing rapidly and displaying a wide spreading crown. | 0 |
This application is a continuation of application Ser. No. 07/852,311, filed Mar. 19, 1992 now abandoned.
BACKGROUND OF THE INVENTION
This application claims the priority of Japanese Patent Application No. 3-109410 filed on May 14, 1991 and No. 3-59094 filed on Mar. 22, 1991 which are incorporated herein by references.
1. Field of the Invention
The present invention relates to a solder-bonded structure which is formed on a substrate.
2. Description of the Related Art
The ability for hybrid ICs (integrated circuit) to withstand extreme environmental conditions has recently been demanded. In particular, hybrid ICs for vehicles are required to have excellent durability when exposed to various temperatures. Especially, the durability of the hybrid ICs when they are repeatedly exposed to low temperature and high temperature, i.e., the durability to a so-called heat cycle is considered most important.
Generally, conventional hybrid ICs for vehicles or the like are fabricated as follows. As shown in FIG. 11, a patterned screen mask (not shown) is attached on a hybrid IC substrate 22 of alumina (hereafter simply referred to as "substrate"). Screen printing is then performed on the substrate 22. A conductor paste is coated on the substrate 22 in the form of a circuit pattern. The pasted substrate is then sintered, thereby forming a conductor 23 on the substrate 22. The elements of the conductor 23 are included in the paste.
The conductor 23 is generally made of silver alone or in combination with platinum [Ag/Pt=99.0 to 99.3/1.0 to 0.7 (weight ratio)]. When the conductor 23 is formed through the sintering process, a connection layer 25 shown in FIG. 11 is formed between the substrate 22 and the conductor 23. The connection layer 25 mainly consists of composite aluminum oxide, which has bismuth and copper in the paste incorporated therein.
Soldering cream is coated at a predetermined position on the conductor 23, and electronic parts 27 are arranged on the soldering cream. Then, a so-called reflow process is carried out for the substrate 22 provided with the electronic parts 27. In the reflow process, the soldering cream is melted and then cooled and solidified, providing a solder layer 24. At this time, the solder layer 24 is bonded with the electronic parts 27.
The solder layer 24 generally contains silver, tin and lead [Ag/Sn/Pb=2/62/36 (weight ratio)]. During the reflow process, a silver-tin alloy layer (intermetallic compound) 26 is formed between the conductor 23 and the solder layer 24. It assumes that silver contained in the conductor 23 and tin in the solder layer 24 are mutually diffused to provide the intermetallic compound 26.
Heat cycle tests conducted on the above-described hybrid IC showed that the greater the number of heat cycles is, the more significant the reduction in peel strength of the electronic parts 27 from the substrate 22 becomes. When the electronic parts 27 were detached from the substrate 22 after such cycling, it was observed that peeling had occurred between the substrate 22 and the connection layer 25 in most cases.
SUMMARY OF THE INVENTION
The present invention has been proposed with a view to solving the above problems, and it is therefore an object of the present invention to provide a solder-bonded structure with strong bonding power which has good durability against repeated heat cycles.
To achieve the object, an improved solder-bonded structure is disclosed. The structure includes a conductor formed on a substrate. The conductor is formed from silver and platinum. A solder layer formed from a tin and silver solder is then formed on the conductor to couple an electronic element to the conductor.
In preferred aspects of the invention, the invention is applied to hybrid ICs. The preferred silver content in the solder layer is in the range of approximately 0.1 to 5.0% by weight.
In a method aspect of the invention, a method of fabricating a hybrid IC is disclosed. In the method aspect, a patterned screen mask is provided on a substrate. A silver and platinum paste is then coated on the masked substrate to form a circuit pattern. The coated substrate is sintering to form a conductor layer on the substrate, there being a connection layer formed between the substrate and the conductor layer during the sintering step. A tin and silver soldering cream is then coated on the sintered conductor layer. An electronic part is placed on the soldering cream and the resultant structure is soldered to form a solder layer that attaches the electronic part to the conductor layer.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention, together with the objects and advantages thereof, may best be understood by reference to the following description of the presently preferred embodiment in conjunction with the accompanying drawings in which:
FIG. 1 is an exemplary fragmentary cross section of an IC for explaining a solder-bonded structure according to one embodiment of the present invention;
FIG. 2 is a graph showing the relationship between a cumulative failure rate and the number of heat cycles in the embodiment;
FIG. 3 is a graph showing the relationship between the peel strength of electronic parts and the number of heat cycles in the embodiment;
FIG. 4 is a microphotograph of a first peeling mode when peeling is performed in the embodiment;
FIG. 5 is a microphotograph of a second peeling mode when peeling is performed in the embodiment;
FIG. 6 is a microphotograph of a third peeling mode when peeling is performed in the embodiment;
FIG. 7 is a microphotograph showing the initial state of a soldering material in the embodiment;
FIG. 8 is a microphotograph showing the state of the soldering material in the embodiment after a heat cycle test is conducted;
FIG. 9 is a microphotograph showing the initial state of a soldering material in Comparative Example 1;
FIG. 10 is a microphotograph showing the state of the soldering material in Comparative Example 1 after a heat cycle test is conducted; and
FIG. 11 is an exemplary fragmentary cross section of an IC for explaining a conventional solder-bonded structure.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
A preferred embodiment of the present invention embodied in a hybrid IC for a vehicle will now be described in comparison with various comparative examples, referring to the accompanying drawings.
FIG. 1 presents a cross-sectional view of essential portions which illustrate a hybrid IC 1 according to this embodiment. As shown in FIG. 1, a conductor 3 is provided on an alumina substrate 2. The conductor 3 is formed as follows. First, a patterned screen mask is attached on the substrate 2. Next, screen printing is performed on the substrate 2. Conductor paste is then coated on the substrate 2, forming a circuit pattern. The conductor paste contains a binder, silver and platinum as its main constituent and a small amount of bismuth and copper. The substrate 2 with the paste is sintered, thereby forming the conductor 3 on the substrate 2. The elements of the conductor 3 are included in the paste.
The conductor 3 comprises silver and platinum with the platinum content being approximately 0.8% by weight. The most preferable platinum content is approximately 0.7 to 1.0% by weight. If the platinum content is less than 0.7% by weight, it is not so desirable because that silver atoms tend to diffuse into the solder layer. Additionally, the circuit pattern may be short-circuited during use of the IC due to the migration of silver ions in the conductor 3 caused by the potential difference that occur during use. On the other hand, when the platinum content exceeds 1.0% by weight, it is not so desirable for much the same reason. That is, because of the diffusion of silver atoms during soldering and the migration of the silver ions during use. Further, the production cost of the conductor increases.
When the conductor 3 is formed by sintering the substrate 2 with the circuit pattern formed thereon, a connection layer 5 is formed between the substrate 2 and the conductor 3. The connection layer 5 essentially contains composite aluminum oxide, which has bismuth and copper in the paste incorporated therein.
A solder layer 4 is formed on the conductor 3, and lead wires 7 which constitute a part of the hybrid IC 1 are provided on the solder layer 4. Soldering cream containing the composition of the solder layer 4 is coated at a predetermined position on the conductor 3. The soldering cream consists of silver, tin and a flux. After the lead wire 7 are arranged on the soldering cream, a reflow process is carried out for the thus treated conductor 3 to form a solder layer 4. The solder layer 4 consists of tin and silver (Example 1). By way of example, one appropriate solder composition includes silver and tin contents of 3.5% and 96.5% by weight, respectively. These contents correspond to a composition at an eutectic point of a silver-tin alloy. When the solder layer having such composition is used, it is possible to lower the melting point of the solder and to decrease the heat influence on the ICs during the reflow process. It is also possible to increase a solidifying rate and to promote refining the crystal structure. The preferable silver content is approximately 0.1 to 5.0% by weight. If the silver content is less than 0.1% by weight, it is not so desirable because the diffusion of the silver atoms in the conductor into the solder layer tends to occur. On the other hand, when the silver content exceeds 5.0% by weight, it is not so desirable because the solidifying rate tends to decrease.
A silver-tin alloy layer (intermetallic compound) 6 is formed between the conductor 3 and the solder layer 4 after they have experienced heat hysteresis in the reflow process. The intermetallic compound 6 is provided by diffusion of silver in the conductor 3 and tin in the solder layer 4. It is to be noted that since such diffusion is difficult to occur in this embodiment even when the conductor 3 and solder layer 4 are subjected to various types of heat hysteresis, the intermetallic compound 6 is very thin.
Comparison of this example with conventional solder-bonded structures will now be described. In Comparative Example 1 was used solder which had a composition ratio of 62% by weight of tin, 36% by weight of lead and 2% by weight of silver. In Comparative Example 2 was used solder having a composition ratio of 46% by weight of tin, 46% by weight of lead and 8% by weight of bismuth. In Comparative Example 3, solder had a composition rate of 10% by weight of tin, 88% by weight of lead and 2% by weight of silver. Solder compositions and mechanical properties in Comparative Examples 1 to 3 and Example 1 are shown in Table 1.
A heat cycle test was conducted for samples having those four solder-bonded structures to find out the relationship between a electric characteristic cumulative failure rate and the number of heat cycles in the individual case. The failure means increased electric resistance or disconnection between the solder layer and the lead wire. The test results are shown in FIG. 2. FIG. 3 shows the relationship between the peel strength when the electronic parts were peeled from the substrate and the number of heat cycles. One heat cycle in this test was that the solder-bonded structures were each left in a low-temperature air tank at -55° C. for 30 minutes and then in a high-temperature air tank at 150° C. for 30 minutes.
As shown in FIG. 2, the samples of Comparative Examples 1 and 2 have high failure rates at the time of 250 cycles. On the contrary, the samples of Comparative Example 3 and Example 1 had later failure starting and a gentler increase in the failure rate than Comparative Examples 1 and 2. In other words, it is apparent that failures do not easily occur in the samples of Comparative Example 3 and Example 1.
As shown in FIG. 3, the initial peel strengths of the samples of Comparative Examples 2 and 3 are low by 30% compared with those of the samples of Comparative Example 1 and Example 1. Further, the initial peel strength of the sample of Comparative Example 1 is equal to that of the sample of Example 1. After 250 heat cycles, however, the peel strength of the sample of Comparative Example 1 was reduced to 40% of the initial strength, while the sample of Example 1 maintained approximately 90% of the initial peel strength after 250 heat cycles. Even after 1000 cycles, the sample of Example 1 retained 50% of the initial strength or more, and were proved to have excellent durability. It is apparent from the overall results that the sample of Example 1 is the most excellent for practical use.
Next, peeling modes were examined. FIGS. 4 to 6 are microphotographs showing different peeling modes when peeling occurred. The first mode in FIG. 4 shows a breakage at the junction between a lead wire and a solder layer, and the lead having come out from the solder layer. The second mode in FIG. 5 shows that the entire conductor was peeled leaving only a brown film at the position where the conductor had been located. The third mode in FIG. 6 shows peeling with the white base of the substrate appeared.
The samples of Comparative Examples 1 and 2 were peeled in the second or third mode shown in FIG. 5 or 6 in most cases. The samples of Comparative Example 3 and Example 1 were peeled most of times in the first mode shown in FIG. 4. The peeling in the second or third mode in FIG. 5 or 6 means that the connection layer between the conductor and the substrate is deteriorated. That is, it is obvious that in the sample of Example 1 the connection layer between the conductor and the substrate can have less deterioration.
Table 2 shows deterioration of connection layers made of different soldering materials.
As shown in Table 2, in the samples of Comparative Examples 1 and 2, coarseness of crystalline particles in the connection layers, soldering cracks (cracks formed in the solder layers) and substrate cracks (cracks formed in the substrates) occurred at the stages of 250 cycles or 500 cycles. The samples of Comparative Example 3 and Example 1 had later occurrence of coarseness of their crystalline particles, cracks in the solder layers and the substrates. In other words, the sample of Example 1 has excellent durability to heat cycles.
The above deterioration is considered to have occurred because of the following reasons. When tin as a soldering material is diffused in the conductor containing silver as a main component, the silver-tin alloy layer (intermetallic compound) such as Ag 3 Sn is formed. The volume is expanded at this time, causing a crack. It is considered that this decreases the bonding strength. In this respect, change in the state of diffusion of metals in the samples of Comparative Example 1 and Example 1 was studied.
FIGS. 7 and 8 are microphotographs respectively showing the initial state of the sample of Example 1 and the state thereof after 500 heat cycle tests. FIGS. 9 and 10 are microphotographs respectively showing the initial state of the sample of Comparative Example 1 and the state thereof after 500 heat cycle tests. As shown in FIGS. 9 and 10, a silver-tin alloy layer (intermetallic compound) was formed after 500 heat cycle tests were conducted for the sample of Comparative Example 1. In the sample of Example 1, a silver-tin alloy layer (intermetallic compound) had hardly changed from the initial state, as apparent from FIGS. 7 and 8.
Further, quantitative analysis was carried out for elements in the conductors of the respective samples before and after the heat cycle test (after 500 cycles were complete). The results are shown in Table 3.
As apparent from Table 3, before the test, the proportion of the elements of each of the conductors in Comparative Examples 1 and 2 was not constant, and differed depending on spots where the samples for elemental analysis were picked up. After the test, however, tin was diffused in the entire conductor in each sample of Comparative Examples 1 and 2, and Ag:Sn was approximately 3:1.
In Comparative Example 3 and Example 1, the proportion of the elements of each conductor both at the initial stage and after the test was almost constant, and Ag:Sn was approximately 3:1. In the sample of Example 1, therefore, the stable silver-tin alloy layer (intermetallic compound) 6 is formed thin between the conductor 3 and the solder layer 4 at the initial stage. Under high temperatures, the silver-tin alloy layer (intermetallic compound) 6 can suppress the metal contained in the solder layer 4 from being diffused into the conductor 3, and prevent further growth of the metallic compound.
As described above in detail, in the hybrid IC 1 (Example 1) according to this embodiment, the conductor 3 on the substrate 2 is made of silver and platinum, and the solder layer 4 is made of only tin and silver. Stronger solder bonding can therefore be realized, and excellent durability to heat cycles can be demonstrated at the bonded junctions.
TABLE 1______________________________________ Fusion Tensile Elon-Solder Temperature (°C.) Strength gationComposition Liquidus Solidus (kg/mm.sup.2) (%)______________________________________Comp. 62Sn36Pb2Ag 183 183 5.40 30Exam-ple 1Comp. 46Sn46Pb8Bi 175 165 4.77 48Exam-ple 2Comp. 10Sn88Pb2Ag 300 275 4.10 45Exam-ple 3Exam- 96.5Sn3.5Ag 221 221 2.01 73ple 1______________________________________
TABLE 2__________________________________________________________________________Comp. Comp. Comp. ExampleExample 1 Example 2 Example 3 1__________________________________________________________________________Number 250 500 1000 250 500 1000 250 500 1000 250 500 1000ofCyclesCoarse X X X X X X ◯ ◯ ◯ ◯ ◯ ◯ness ofCrystallineParticlesSolder X X X ◯ X X ◯ ◯ X ◯ ◯ XCrackSubstrate X X X X X X ◯ ◯ X ◯ ◯ XCrack__________________________________________________________________________ X: Occurred ◯: None
TABLE 3______________________________________ Sn Ag Pb Pt Bi______________________________________Comparative 25.6 66.2 6.1 2.1 --Example 1 Initial 18.3 77.1 2.8 1.8 -- 34.3 58.7 5.5 1.5 -- After test 22.9 72.4 3.1 1.6 --Comparative 18.8 45.5 29.8 1.8 4.1Example 2 Initial 22.6 58.9 13.3 1.7 3.5 19.3 58.2 18.0 1.3 3.2 After test 23.3 73.1 2.4 1.2 --Comparative Initial 22.9 72.7 2.5 1.9 --Example 3 After test 22.1 73.1 3.2 1.6 --Example 1 Initial 25.3 72.7 -- 2.0 -- After test 24.9 78.8 -- 1.5 --______________________________________ Values in Table 3 indicate at % (atomic percentage). | An improved solder-bonding structure is disclosed that is particularly suitable for soldering the components of hybrid ICs. The solder-bonding structure includes a conductor formed on a substrate. The conductor is formed from silver and platinum. A solder layer formed from a tin and silver solder is then formed on the conductor to couple an electronic element to the conductor. In preferred aspects of the invention, the platinum content in the conductor is in the range of approximately 0.7 to 1.0% by weight. The silver content in the solder layer is in the range of approximately 0.1 to 5.0% by weight. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This is a national stage application of PCT/CA93/00075, filed Feb. 25, 1993, which is a continuation-in-part of U.S. application Ser. No. 07/982,118, filed Nov. 25, 1992, now abandoned, which is a continuation of U.S. application Ser. No. 07/843,155, filed Feb. 28, 1992, now abandoned.
FIELD OF THE INVENTION
This invention relates to fabrics intended for use in the manufacture of paper and like products, in which hollow monofilaments replace at least a portion of the wefts, also known as cross-machine directions strands. The invention is particularly applicable to paper machine dryer fabrics.
DESCRIPTION OF THE PRIOR ART
The primary function of a dryer fabric is to hold the paper web in contact with the heated surfaces of the dryer cylinders. This increases the efficiency of heat transfer and improves the flatness of the paper.
An important property of dryer fabrics intended for use in modern, high-speed paper making machines is low permeability to air flow. Dryer fabrics must have low air permeabilities so as to prevent sheet flutter and, ultimately, breakage of the sheet (as documented by Race, Wheeldon, et al. in TAPPI, vol. 51, no. 7, July 1968). Low air permeability values may be considered to be those in the range of 127 cm 3 /cm 2 ·s (250 ft 3 /min/ft 2 ) or below. It is also desirable that the air permeability of the fabric be constant throughout both the fabric itself, and its operational life.
It is difficult to obtain low air permeabilities in woven dryer fabrics when solid monofilaments are used as the weft strands. Manufacturers of dryer fabrics have thus traditionally resorted to incorporating spun yarns, multifilament yarns or plied monofilaments in order to obtain low air permeabilities in conventional dryer fabric designs. These types of yarns, however, make it difficult to accurately control fabric air permeability during manufacture. They also allow foreign matter to become entrapped in the fabric, which changes the air permeability of the fabric throughout its life on the paper making machine. Trapped contaminants are usually distributed unevenly in the fabric, and will cause uneven drying of the paper web. The use of spun yarns, multifilament yarns, or plied monofilaments in dryer fabrics also reduces the efficiency with which water is evaporated out of the paper web, because water tends to condense and be retained within such yarns.
Another method of lowering fabric air permeability is to use machine direction strands that are essentially rectangular in cross-section. Such a method is disclosed by Buchanan et al. in U.S. Pat. No. 4,290,209. This patent also discloses the use of shaped or hollow monofilaments as weft strands to further reduce dryer fabric air permeability. However, it does not teach the critical physical parameters required for the hollow monofilaments, such as strand diameter, or solidity of cross-sectional area. No data is disclosed as to the effectiveness of hollow monofilament weft strands in reducing fabric air permeability.
Goetemann, et al., in U.S. Pat. No. 4,251,588 teach the use of hollow monofilaments to improve dimensional stability and flex life in paper machine clothing. The range of void fractions in the yarn cross-sectional area disclosed is from 0.03 to 0.15 (3% to 15%), or a range of solidities of from 97% to 85%. Solidities less than 85% were not recommended because such monofilaments would flatten from a circular cross section to a void-free filament. Goetmann et al. also teach that conventional techniques may be used to weave these hollow monofilaments into papermaking fabrics without collapsing them. No consideration is given to any interrelationship between the strand diameter of the hollow monofilament, its solidity, and the space available within the woven structure to accommodate the yarns. The use of these hollow monofilaments for the purpose of reducing fabric air permeability is not taught.
It is also difficult to obtain low fabric air permeabilities in spiral fabrics. These fabrics are assembled from a multiplicity of helical coils which are intermeshed and connected together in a hinged relationship by hinge yarns, substantially as described by Kerber in DE 2,419,751, Leuvelink in U.S. Pat. No. 4,345,730, and Dawes in U.S. Pat. No. 4,481,079. The air permeability of these fabrics is typically altered by inserting a shaped, solid monofilament into the space within the helical coils and between the hinge yarns. The cross-sectional shape of the inserted monofilament is determined so as to efficiently fill the space between the hinge yarns, thus lowering the air permeability of the fabric. Commonly used shapes include: ellipses, rectangles, trapezoids, a "D", or a "dog bone". It is also known to perforate such yarns along their length so as to further assist in controlling air permeability, as taught by Gauthier in U.S. Pat. No. 4,567,077. However, a disadvantage of using shaped monofilaments in spiral fabrics is that they are not effectively locked in position and are prone to falling out during the drying operation on the paper making machine.
The predominant material used in the manufacture of dryer fabrics is polyethylene terephthalate (PET) that has been stabilized to reduce its rate of hydrolytic degradation. However, in the harshest dryer sections, where high temperatures (greater than 150° C.) occur, other more expensive polymers are commonly used. Such polymers include: blends of. polyphenylene sulphide (PPS), as disclosed by Baker et al. in U.S. Pat. No. 4,755,420, and polyetherether ketone (PEEK), as disclosed by DiTullio in U.S. Pat. No. 4,359,501 and Searfass in U.S. Pat. No. 4,820,571. While vastly superior to PET in hydrolysis resistance, their higher cost restricts their usage due to economic considerations.
SUMMARY OF THE INVENTION
This invention seeks to overcome the aforementioned deficiencies of the prior art by providing a papermaker's heatset fabric, for use in paper making or like machines, wherein at least a portion of the weft strands are hollow thermoplastic monofilaments which have a solidity in their undeformed cross-sectional area of from about 50% to about 80%, and which have a diameter such that they are deformed in the weft passageway to be filled in the woven fabric during heatsetting.
Thus in a first broad embodiment, this invention seeks to provide a woven, heatset fabric, for use in papermaking and like machines, wherein at least a portion of the weft strands are hollow thermoplastic polymer monofilaments which have a solidity in their undeformed cross-sectional area of from about 50% to about 80%, and wherein the circumference of said hollow monofilaments is greater than, or equal to, the perimeter of the weft passageway they are to occupy in the fabric after heatsetting.
In a second broad embodiment, this invention seeks to provide a heatset spiral fabric, for use in papermaking and like machines, comprising a plurality of helical coils interconnected by hinge yarns, including hollow monofilament weft strands having a solidity in their undeformed cross sectional area of from about 50% to about 80%, located within the helical coils and between the hinge yarns, wherein the diameter of hollow monofilaments is greater than the interior length of the minor axis of the helical coils in the heatset fabric, and further wherein the hollow monofilaments are deformed by the helical coils as a consequence of heatsetting of the fabric.
In either a woven or spiral fabric according to this invention, the hollow monofilaments will generally have an outside diameter in the range of between about 0.25 mm and 2.1 mm.
For the purposes of the present application, the following terms are defined for use herein as shown:
Heatsetting: processes such as are well known to those skilled in the art whereby a fabric structure is stabilized under conditions of elevated temperature and tension;
Perimeter of the weft passageway: the perimeter of the projection of the passageway into which a weft yarn is to be placed, onto a plane which is normal to the weft direction. It is understood that such a passageway will not have a constant or continuous cross-section in space along the length of the weft strand, and therefore the hollow monofilament will not be squeezed uniformly along its length at every warp intersection;
Solidity: the percentage of solid material which is present at any cross-section through the undeformed hollow monofilament prior to heatsetting, relative to the total cross-sectional area of the monofilament that is enclosed by its circumference at that cross-section; and
Weft: cross-machine direction strands of a woven fabric, or strands which have been inserted into the helices and between the hinge yarns of a spiral fabric.
Unless otherwise stated, all references made below to the diameter of the hollow monofilaments of this invention assume that these monofilaments have not been deformed in any way by heat setting.
The solidity of the hollow monofilaments intended for use in the paper machine fabrics of this invention is critical. We have found that the useful range of solidities is from about 50% to about 80% with from about 55% to about 78% being preferable, and from about 60% to 75% most preferable. We have experimentally determined that solidities within this range will provide these monofilaments with adequate deformational capability, a critical factor in lowering the air permeability of a fabric. If the solidity is too low, the hollow monofilaments may fracture or deform excessively, or be destroyed during weaving. If the solidity of the hollow monofilaments is too high, inadequate deformation occurs and the resulting reduction in fabric air permeability will be insignificant. This range of solidity also provides the monofilaments with sufficient mechanical strength so as to withstand the rigours of fabric creation, heat setting, seaming, assembly and subsequent use in the paper machine.
The sizing of these hollow monofilaments is an important feature of this invention. We have discovered that the effectiveness of the hollow monofilaments is greatest when their exterior circumference, prior to heatsetting, is greater than or equal to the perimeter of the weft passageway they are to occupy in a woven fabric after heatsetting. If their circumference is less than this value, then air permeability can only be reduced by increasing the weft count (number of wefts per unit length) of the fabric. This will reduce the perimeters of the weft passageways in the cloth, thereby allowing the hollow monofilaments to now fill the space between the warp yarns.
We have found that, for currently available fabrics, the useful circumference of the hollow monofilaments of this invention, for use in woven fabrics, will correspond to diameters of from about 0.25 mm to about 1.2 mm. Hollow monofilaments whose circumference corresponds to diameters of from about 0.50 mm to about 2.1 mm will be of use in spiral fabrics.
The outer diameter of a hollow monofilament that will completely fill the perimeter of the available space in a heatset fabric is estimated by calculating the perimeter of the shape to be filled, and equating that value to the outer circumference of the hollow monofilament, hence its outside diameter, using the relation:
C=πd. [Equation 1]
where
C=circumference, and d=diameter.
If the circumference of the hollow monofilament is selected so as to be greater than or equal to the perimeter of the weft passageway in the heatset fabric, the maximum solidity of the hollow monofilament which will not alter the geometry of the fabric should then be determined. Increasing the solidity beyond this maximum generally increases fabric thickness which, in turn, increases air permeability.
If the outer diameter of the monofilament is calculated using Equation 1, and is equal to the perimeter of the area to be filled, then the maximum solidity can be calculated by assuming that all of the solid material of the round hollow monofilament is deformed either elastically or plastically during weaving and heatsetting until the void space of the hollow monofilament is entirely consumed. The calculations which follow assume that the material is incompressible and that the fabric is heatset, unless indicated otherwise.
If the perimeter of the weft passageway to be filled is, for example, a square whose sides are of a length a, then the perimeter C of the square is:
C=4a. [Equation 2]
Assuming the circumference of the hollow monofilament is equal to this perimeter, then from Equation 1:
C=4a=πd. [Equation 3]
Solving for d,
d=(4/π)a. [Equation 4]
This is the minimum diameter of a hollow monofilament that will fill the available space.
Solidity is defined as:
S=(A.sub.s /A.sub.T)×100, [Equation 5]
where
S=solidity of the hollow monofilament,
A s =cross sectional area of the hollow monofilament that is occupied by solid material, and
A T =total cross sectional area bounded by the outside diameter of the hollow monofilament.
A s cannot exceed the cross sectional area to be filled, thus the maximum A s is equal to the cross sectional area to be filled, when the hollow monofilament is completely deformed to a void-free filament; hence:
A.sub.s =a.sup.2 [Equation 6]
and the total cross sectional area of the hollow monofilament is
A.sub.T =(π/4)d.sup.2. [Equation 7]
Substituting and solving for solidity S:
S=[a.sup.2 /(π/4)d.sup.2 ]×100 [Equation 8]
Substituting d from Equation 4:
S={[(π/4)d].sup.2 /[(π/4)d.sup.2 ]}×100=S=(π/4)×100
S≈78.5%
The above calculation demonstrates that a hollow monofilament whose solidity is greater than 78.5% must alter the geometry of the fabric if it is also sized in its outside diameter so as to fill the perimeter of a square opening. Use of hollow monofilament size and solidity combinations which will alter fabric geometry are not recommended. These calculations are therefore intended to:
1) guide the user in choosing the optimum outside diameter of the hollow monofilament for a particular application, and
2) indicate the maximum solidity which can be used at that diameter without altering the geometry of the fabric.
It is well known that heatsetting reduces the perimeter of the weft passageways in the fabric, and those skilled in this art will appreciate that the size of these weft passageways after heatsetting cannot be measured beforehand. As a guide only, the effective size of the hollow monofilaments for use in the fabrics of this invention may be estimated by measuring the perimeter of the weft passageways in the fabric prior to heatsetting, and then sizing the hollow monofilaments so that their circumference is greater than, or equal to, that perimeter. However, care must be taken to ensure that the solidity of the hollow monofilaments is low enough so as not to alter the geometry of the fabric after heatsetting.
We have experimentally determined that the practical lower limit of the solidity of these hollow monofilaments for paper machine fabric applications is about 50%, and is controlled by two unexpected factors.
1) Hollow monofilaments with solidities below 50% tend to buckle and collapse, rather than deform and take the shape of the perimeter they are to occupy, thus rendering them ineffective. This is particularly true when the circumference of the monofilament is equal to or greater than the perimeter of the space to be filled in the heatset fabric.
2) Hollow monofilaments with solidities below 50% are prone to crushing, and is easily damaged in industrial looms.
The present invention seeks to provide a woven dryer fabric, for use in the manufacture of paper and like products, whose air permeability is both low and uniformly constant throughout. This objective is achieved in practice by incorporating hollow monofilaments of optimum strand diameter and solidity as at least a portion of the fabric weft strands.
This invention also seeks to provide a spiral fabric, for use in the dryer section of paper making and like machines, whose air permeability is both low and uniformly constant throughout. This objective is achieved in practice by placing hollow monofilaments in the spaces between the hinge yarns within the helical coils of these fabrics, thereby eliminating any need to provide a specially shaped monofilament. The deformable nature of the hollow monofilaments improves their retention within the spiral fabric during its operation on the paper making machine, thus reducing the incidence of fabric failure due to loss of the solid, prior art yarns which had been "stuffed" into these spaces.
Incorporation of hollow monofilaments in at least a portion of the weft positions will provide the novel fabrics of this invention with the following advantages over fabrics of the prior art:
1) a lower air permeability can be achieved while maintaining the all-monofilament characteristic of the fabric, with the resulting benefits of cleaner operation;
2) less moisture is carried by the fabric;
3) a more consistent and uniform air permeability is provided throughout the fabric, because the physical characteristics of hollow monofilaments are inherently less variable than those of spun yarns, multifilament yarns or plied monofilaments; and
4) retention of spiral fabric weft under paper making machine operating conditions is improved.
Further, the novel fabrics of this invention require less material, by weight, to manufacture than comparable prior art fabrics because the hollow monofilaments have less mass per unit length than solid monofilaments of the same diameter. Their use is particularly advantageous when expensive polymers are required.
In addition, the weavability of paper machine fabrics can be improved by incorporating hollow monofilaments as at least a portion of the weft yarns. Since the hollow monofilaments have less mass than comparably sized solid monofilaments, their inertia is lower. This reduces problems associated with the acceleration and deceleration of large diameter monofilaments on high speed weaving looms, which, in turn, reduces weaving defects in the fabrics.
The incorporation of hollow monofilaments into paper making fabrics so as to reduce their air permeability is effective in both multi-layer and single layer fabric designs. A multi-layer fabric is one in which the weft strands lie in a series of essentially discrete tiers or planes within the fabric. A single layer fabric is one in which the weft strands lie in essentially one common plane within the fabric.
Multi-layer fabrics, manufactured in accordance with the teachings of this invention, may contain hollow monofilaments selectively positioned in all layers, selected layers, or in only one layer, of a fabric.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will now be described with reference to the examples illustrated by the accompanying drawings in which:
FIG. 1 is a sectional view of an all-monofilament multi-layer dryer fabric of the prior art, in which all weft strands are solid monofilaments;
FIG. 2 is a sectional view of a fabric substantially identical to that shown in FIG. 1 in which the solid monofilament weft strands of the intermediate layer have been replaced with hollow monofilaments of the prior art, whose solidity is about 90%;
FIG. 3 is a sectional view of a fabric substantially identical to that shown in FIG. 1, in which the solid monofilament weft strands of the intermediate layer have been replaced with hollow monofilaments whose solidity is about 45%;
FIG. 4 is a sectional view of a fabric substantially identical to that shown in FIG. 1, in which the solid monofilament weft strands of the intermediate layer have been replaced with hollow monofilament strands according to the present invention;
FIG. 5 is an isometric view of a single layer, all monofilament dryer fabric in which 50% of the weft strands are hollow monofilaments according to the invention;
FIG. 6 is a cross-section on the line I--I in FIG. 5;
FIG. 7 is a cross section on the line II--II in FIG. 5;
FIG. 8 is a sectional view of a spiral fabric into which hollow monofilaments have been inserted according to the invention; and
FIG. 9 is a cross-section on line III--III of FIG. 8.
DETAILED DESCRIPTION OF THE INVENTION
Referring first to FIG. 1, there is shown diagrammatically the construction of an all-monofilament, 4-shaft, 12-repeat, multilayer dryer fabric of a design that is commonly used in the papermaking industry. FIG. 1 illustrates the cross-sectional appearance of said fabric following heatsetting. There are four consecutive warp strands, 10, 11, 12 and 13. The weft strands comprise three layers. In sequence from the top of FIG. 1, these are strands 20, 21, 22, 23 and 24; in the middle, strands 25, 26, 27 and 28; and at the bottom, strands 30, 31, 32, 33 and 34. The intermediate layer of wefts, strands 25, 26, 27 and 28, are solid monofilaments of the same diameter as the other wefts and are inserted into the fabric to assist in reducing its air permeability. It is known to use other yarns in this intermediate layer, such as spun yarns, plied monofilaments, or multifilaments.
A typical prior art fabric, made with the construction shown in FIG. 1, has an air permeability in the range of 152 to 203 cm 3 /cm 2 ·s (300-400 ft 3 /min/ft 2 ). Fabric air permeability is measured using the method and calculations described in American Society for Testing and Materials Standard ASTM-D-73775-75 The air permeability figures given below were measured according to this method using a Frazier Air Permeometer.
FIG. 2 illustrates diagrammatically a heatset dryer fabric whose weave design is substantially identical to that shown in FIG. 1. This fabric differs from that shown in FIG. 1 in that hollow monofilaments of the prior art, having a solidity of about 90% and whose diameter is substantially the same as the solid wefts, have been inserted in place of the solid monofilaments in the intermediate layer. That is, wefts 1, 2, 3 and 4, which are in the same place as wefts 25, 26, 27 and 28 in FIG. 1, are hollow monofilaments as taught by Goetmann et al. Accordingly, a cross-section taken through these high solidity strands shows that they have undergone minimal deformation when woven into a fabric and subsequently heatset. The physical properties of these prior art hollow monofilaments are so similar to those of comparably sized solid monofilaments, that the air permeability of a fabric in which they are incorporated is not significantly reduced in comparison, for example, to an identical, solid yarn fabric such as is shown in FIG. 1.
FIG. 3 illustrates diagrammatically a heatset dryer fabric whose weave design is also substantially identical to that shown in FIG. 1. The solid monofilament wefts, 25, 26, 27 and 28 in the intermediate layer of FIG. 1, have now been replaced with hollow monofilaments 5, 6, 7 and 8 whose solidity is approximately 45% and whose diameter is substantially the same as the solid wefts. A hollow monofilament having 45% solidity, will have a wall thickness of only some 26% of the monofilament radius. FIG. 3 is provided to illustrate the deformation which would occur to these low solidity hollow monofilaments when incorporated into the intermediate weft positions. As can be seen, the relatively thin walls of these monofilaments were crushed by the forces of weaving, and did not deform so as to fill the available space in the desired manner. Thus, these low solidity monofilaments did not achieve the desired effect of consistently reducing air permeability throughout the fabric.
FIG. 4 illustrates diagrammatically a heatset dryer fabric manufactured in accordance with the teachings of the present invention and whose weave design is substantially identical to that shown in FIG. 1. Hollow monofilament wefts 40, 41, 42 and 43, whose solidity is about 73% and whose diameter is approximately 40% greater than that of the solid wefts 25, 26, 27 and 28 in FIG. 1 they replace, have now been inserted in the intermediate layer of this fabric. It will be noted that the hollow monofilaments have deformed upon heatsetting so as to fill the perimeter of the weft passageway, thereby effectively lowering fabric air permeability in comparison to the similar fabrics of FIGS. 1, 2 and 3.
FIGS. 5, 6 and 7 illustrate diagrammatically a 4-shed, 4-repeat, single layer, heatset dryer fabric, substantially as taught in U.S. Pat. No. 5,103,874 and which was woven in experimental trials. As is shown in these Figures, the warp yarns are woven in pairs so as to position one member of each warp yarn pair, 50 & 52, substantially above the other, 51 & 53. Both yarns of a warp yarn pair, 50 & 51 and 52 & 53, then pass together over the same side of each of the hollow monofilament weft yarns 61, 63 & 65. Upon heatsetting, the thicker, solid weft yarns 60, 62 & 64 remain more or less straight, whilst the thinner, hollow wefts 61, 63 & 65 are effectively deformed by warps 50 & 51 and 52 & 53 passing around them, as is shown in FIG. 7, so as to substantially fill the perimeter of the weft passageways, thereby lowering fabric air permeability. The hollow monofilaments of this invention are particularly useful when incorporated as at least a portion of the weft yarns in double warp, single layer fabrics such as are illustrated in FIG. 5.
FIG. 6 is a cross section taken at Line I--I in FIG. 5. As each warp yarn pair, 50 & 51 and 52 & 53, approaches a solid monofilament 64, their paths diverge so that one warp yarn pair member, 50 & 52, passes over solid weft 64, whilst the other warp yarn pair member, 51 & 53 passes beneath. Solid monofilament 64 has not been deformed by any appreciable amount during heatsetting so as to more effectively fill the perimeter of the weft passageway.
FIG. 7 is a cross-section taken at Line II--II in FIG. 5. This Figure is provided to illustrate the deformation occurring when a hollow monofilament, 61, that is oversized for this position in comparison to a solid weft, is used to fill the weft passageway. It will be noted that the hollow monofilament 61 is deformed during weaving and by the heatsetting process so as to more completely fill the perimeter of the weft passageway than would either a solid monofilament.
Table 1 displays the effects on fabric air permeability obtained by introducing hollow monofilaments, as at least a portion of the weft, into both multi- and single-layer dryer fabrics, identified as Samples 1 and 2, and Samples 3 and 4 respectively.
The multi-layer fabrics of FIGS. 1 and 4 were both woven in experimental trials, and are identified in Table 1 as Samples 1 and 2 respectively. Both Samples had nearly identical mesh counts, and were heatset under identical conditions. The difference between Samples 1 and 2 is that Sample 2, in accordance with the teachings of this invention, contains hollow monofilaments placed in one third of its weft positions. The 0.50 mm solid monofilament wefts in the intermediate layer of Sample 1 were replaced with 0.70 mm hollow monofilaments having a solidity of 73%. Comparing Samples 1 and 2, a reduction in fabric air permeability of about 49 cm 3 /cm 2 ·s (96 ft 3 /min/ft 2 ) was achieved by replacing one-third of the solid wefts with hollow wefts of the present invention.
The data of Samples 3 and 4 in Table 1 was obtained from two 4-shed, 4-repeat single layer dryer fabrics, substantially as shown in FIGS. 5, 6 and 7, which were woven in experimental trials. In Sample 3, all of the weft yarns were solid monofilaments with diameters of 0.5 mm and 0.9 mm and placed in alternating positions. In Sample 4, 0.7 mm diameter hollow monofilaments of 73% solidity replace every 0.5 mm solid weft yarn in Sample 3. Both Samples have substantially the same mesh counts and were heatset under identical conditions. Comparing Samples 3 and 4, it will be seen that a reduction in fabric air permeability of 46 cm 3 /cm 2 ·s (90 ft 3 /min/ft 2 ) was achieved by replacing one-half of the solid wefts of Sample 3 with hollow wefts according to the present invention, as in Sample 4.
TABLE 1______________________________________Effect of Hollow Monofilaments on DryerFabric Air Permeability______________________________________ Sample 1 Sample 2______________________________________Mesh (cm.sup.-1) (a) 16.9 × 19.5 16.9 × 18.7Solid Monofilament 0.5 0.5Size (mm)% Solid Wefts 100 67Hollow Monofilament n/a 0.7Size (mm)% Hollow Wefts 0 33Hollow Weft n/a 73Solidity (%)Air Permeability 176 127(cm.sup.3 /cm.sup.2 · s) (b)Difference in Dryer Fabric Air Permeability(Sample 1 - Sample 2) = 49 cm.sup.3 /cm.sup.2 · s______________________________________ Sample 3 Sample 4______________________________________Mesh (cm.sup.-1) (a) 22.4 × 1.5 22.8 × 7.5Solid Monofilament 0.9 & 0.5 0.9Size (mm)% Solid Wefts 100 50Hollow Monofilament n/a 0.7Size (mm)% Hollow Wefts 0 50Hollow Weft n/a 73Solidity (%)Air Permeability 84 38(cm.sup.3 /cm.sup.2 · s) (b)Difference in Dryer Fabric Air Permeability(Sample 3 - Sample 4) = 46 cm.sup.3 /cm.sup.2 · s______________________________________ NOTES: (a) mesh count = number of Warps per cm × number of Wefts per cm (b) air permeability as measured by test method ASTMD-737-15.
Table 1 shows that, under equivalent manufacturing conditions, a substantial reduction in air permeability is achieved by the introduction of hollow weft, which fill more completely the weft passageway than the solid weft they replace, as a portion of the cross machine direction strands.
A hollow monofilament, whose size and solidity are determined in accordance with the teachings of this invention, will effectively replace a solid monofilament in various fabric designs. This is because such a hollow monofilament is more readily deformable and will fill the available space in the fabric more effectively than a solid, and relatively unmalleable, monofilament. This deformation will allow a fabric to attain a lower air permeability than a comparable fabric, containing either solid monofilaments in the same positions and manufactured under equivalent conditions, or one containing hollow monofilaments whose size and solidity are not selected according to the criteria provided herein.
All of the solid monofilament weft yarns in a woven fabric can be replaced with hollow monofilament yarns. Table 2 shows data obtained by replacing all the solid monofilament wefts in a multilayer fabric with slightly larger hollow monofilaments. Both woven samples have nearly identical mesh counts, and were heatset under identical conditions. In Sample 6, 0.55 mm hollow monofilaments replace all of the 0.40 mm solid monofilaments of Sample 5. A reduction in fabric air permeability of about 23 cm 3 /cm 2 ·s (45 ft 3 /min/ft 2 ) was achieved in Sample 6 over Sample 5.
TABLE 2______________________________________Effect on Fabric Air Permeability obtained byReplacing all Solid Monofilaments with Hollow Monofilaments Sample 5 Sample 6______________________________________Mesh (cm.sup.-1) 20.3 × 21.1 20.3 × 17.7Solid Monofilament 0.40 n/aSize, mm% Solid Wefts 100 Zero.Hollow Monofilament n/a 0.55Size, mm% Hollow Wefts Zero 100Hollow Weft n/a 73solidity, %Air Permeability, 66 43cm.sup.3 /cm.sup.2 · s)______________________________________ Difference in air permeability, Sample 5 - Sample 6: 23 cm.sup.3 /cm.sup. · s.
FIGS. 8 and 9 illustrate a diagrammatically spiral fabric into which hollow monofilaments have been inserted within the helical coils and between the hinge yarns. In this form of dryer fabric, a sequence of helical coils, as at 70, 71, 72, in which the axes of the helices are in the weft direction, are joined together by inserted hinge yarns as at 73 and 74, which are also in the weft direction. In this example, the helical coils adopt a flattened, somewhat oval, configuration after heatsetting, as is shown in FIG. 8. The length of the minor axis of the internal void area of the helical coil is labelled "h".
The internal void volume between adjacent areas of the helical coils of such a fabric, as at 75 and 76, is free space and contributes directly to the air permeability of the fabric. As shown in FIG. 8, a hollow monofilament as at 77, 78 and 79, whose outside diameter is greater than or equal to the length h of the minor axis of the helical coils after heatsetting, has been inserted into the middle of the joined helical coils during fabric construction. When the fabric is heatset, the length h of the minor axis of the helical coil is reduced and the hollow monofilament is deformed into a somewhat oval shape, effectively and efficiently filling the internal void volume within the coil, as shown at 78, so as to decrease fabric air permeability.
We have found that hollow monofilaments are most effective in this position when their outside diameter, prior to heatsetting, is equal to or greater than the length, h, of the minor axis of the heatset coil into which they have been inserted. This causes the monofilaments to deform during heatsetting, which serves to hold them in place and prevents the yarns from falling out of the fabric during its life on the paper machine. This deformation of the hollow monofilament in a spiral fabric can be seen in the cross-section parallel to the axis of the spiral shown in FIG. 9.
As previously noted, the useful range of hollow monofilament solidities of this invention is from about 50% to about 80%, and is preferably from about 55% to about 78%, and is most preferably from about 60% to about 75%. We have found that this range of solidities is also critical to spiral fabrics because it provides the hollow monofilaments with:
a) sufficient stiffness to allow them to be inserted into the helical coils and between the hinge yarns by methods currently known in the manufacture of spiral fabrics, and
b) sufficient malleability to allow them to deform during further processing, so as to fill the interstitial spaces within the helical coils and between the hinge yarns; this deformability is the critical factor in lowering fabric air permeability.
Table 3 displays data relating to spiral fabrics which have been assembled using helices made entirely of PET, and into which both solid and hollow monofilaments also made from PET have been inserted into the spaces within the helical coils and between the hinge yarns. All samples were manufactured and heatset under identical conditions. Sample A does not contain any yarns inserted into this position, and therefore acts as a control. So-called "dog-bone" shaped solid monofilaments have been inserted into this same position in Sample B. Samples C-F contain hollow monofilaments of progressively greater diameters and varying solidities inserted into the spaces within the helical coils and between the hinge yarns. The number of spirals per centimeter of cross machine direction (spiral count), hinge yarns per centimeter of machine direction (yarn count), and the hinge yarn diameter, are the same for all samples.
As can be seen from Table 3, a significant reduction in fabric air permeability is achieved by inserting hollow monofilaments, whose diameter, prior to heatsetting, is from 1.8 mm to 2.1 mm, into the spaces within the helical coils and between. the hinge yarns. The bottom row of Table 3, labelled "Air Permeability Net Change", shows the net difference in air permeability obtained from each sample in comparison to the control, Sample A. For example, the air permeability of Sample C has been reduced by 252 cm 3 /cm 2 ·sec (495 ft 3 /min/ft 2 ) in comparison to the control by the insertion of 1.8 mm hollow monofilaments. Similarly, the air permeability of Samples D and E have been reduced by 276 cm 3 /cm 2 ·sec (542 ft 3 /min/ft 2 ) and 312 cm 3 /cm 2 ·sec (613 ft 3 /min/ft 2 ) respectively by insertion of 1.9 mm and 2.0 mm diameter hollow monofilaments. A net change in air permeability of 332 cm 3 /cm 2 ·sec (652 ft 3 /min/ft 2 ) in comparison to the control is realized when a larger, 2.1 mm diameter hollow monofilament, is inserted into the same position, as in Sample F.
TABLE 3______________________________________Effect on Spiral Fabric Air Permeability obtainedby Inserting Hollow Monofilaments made from PET SAMPLE NOParameter A B C D E F______________________________________Spiral Count 6.5 6.5 6.5 6.5 6.5 6.5(cm.sup.-1)Hinge Yarn 2.4 2.4 2.4 2.4 2.4 2.4Count (cm.sup.-1)Hinge Yarn 0.10 0.70 0.70 0.70 0.70 0.70Diameter (mm)Inserted Weft n/a 0.45 × 1.8 1.9 2.0 2.1Size (mm) 2.2Inserted Weft n/a 100 63.4 74.2 65.9 66.5Solidity (%)Fabric Air 432 196 180 156 120 100Permeability(cm.sup.3 /cm.sup.2 · sec)Fabric Air 0 236 252 276 312 332PermeabilityNet Change______________________________________
The data displayed in Table 3 shows that, in general, as the unheatset solidity and diameter of the hollow monofilaments increase together, heatset fabric air permeability values decrease. We have found that the optimum range of solidity of hollow monofilaments is from about 50% to about 80%, with from about 55% to about 78% being more effective, whilst solidities of from about 60% to about 75% are most effective in reducing fabric air permeability. We have also found that the effective diameter of the inserted hollow monofilaments prior to heatsetting will be a function of the length h of the minor axis of the heatset helical coils into which they have been inserted, and this diameter should be equal to, and is preferably greater than, the length h of the minor axis of the heatset helical coil.
Table 4 displays data obtained from PET spiral fabrics into which hollow monofilaments made from polybutylene terephthalate (PBT), or a blend of 10% HYTREL® in PET, have been inserted into the spaces within the helical coils and between the hinge yarns. Fabric Samples G and H contain hollow monofilaments made from PBT, and Samples J, K and L contain hollow monofilaments extruded from a blend of 10% HYTREL® in PET. The design of the fabric samples used to obtain this data is substantially identical to that used in the samples of Table 3 and all were manufactured and heatset under identical conditions. All air permeability net changes are again made in comparison to the control, Sample A, which is the same control used in Table 3. HYTREL® is a registered trademark of DuPont and is a polyester elastomer.
TABLE 4______________________________________Effect on Spiral Fabric Air Permeability Obtainedby Inserting Hollow Monofilaments made from PBTor 10% HYTREL in PET SAMPLE NO.Parameter A G H J K L______________________________________Spiral Count 6.5 6.5 6.5 6.5 6.5 6.5(cm.sup.-1)Hinge Yarn 2.4 2.4 2.4 2.4 2.4 2.4Count (cm.sup.-1)Hinge Yarn 0.70 0.70 0.70 0.70 0.70 0.70Diameter (mm)Inserted Weft n/a 2.0 2.1 1.7 1.9 2.0Diameter (mm)Inserted Weft n/a 56.3 60.4 71.9 72.6 72.0Solidity (%)Fabric Air 432 199 140 269 232 156Permeability(cm.sup.3 /cm.sup.2 · sec)Fabric Air 0 233 292 163 200 276PermeabilityNat Change______________________________________
The data provided in Table 4 shows that the hollow PBT monofilaments of Samples G and H, and the hollow yarns made from 10% HYTREL in PET of Samples J, K and L, were both effective upon heatsetting in reducing fabric air permeability. Table 4 shows that it is possible to obtain net reductions in fabric air permeability which are similar to those obtained using hollow PET monofilaments by using other polymers under equivalent manufacturing conditions. The data displayed in Tables 3 and 4 indicate that hollow monofilaments made from PET are the most effective in reducing spiral fabric air permeability, while the polymer blend of 10% HYTREL® in PET is less effective, and PBT is the least effective among the polymers tested.
Although the selection of the polymer from which the hollow monofilaments are made will have an impact on the effectiveness of these strands in reducing fabric air permeability, we have found that varying the solidity of the strands is the most effective means of decreasing fabric air permeability. Thermoplastic polymers other than PET, PBT, and blends thereof, may be found which will provide hollow monofilaments whose physical properties and characteristics would make them successful candidates for use in the fabrics of this invention. Polyphenylene sulphide (PPS) and polyetherether ketone (PEEK) are examples of such polymers, but the invention is not limited to the polymers referenced herein. In experimental and field trials to date, we have found that PET is an effective polymer for these applications.
As previously noted, the useful diameter of the hollow monofilaments intended for use in woven fabrics will generally be in the range of from about 0.25 mm to about 1.2 mm, while spiral fabrics will utilize yarns whose diameter is from about 0.50 mm to about 2.1 mm. The most effective strand diameter for a particular application will be a function of the available space in the fabric: in a woven fabric, the circumference of the strand will ideally be greater than or equal to the perimeter of the weft passageway in the heatset fabric into which it will be placed, whilst in a spiral fabric, the strand diameter will ideally be greater than the interior length of the minor axis of the heatset spiral.
A significant portion of the expense of manufacturing dryer fabrics is the cost of the material used. By replacing at least a portion of the solid monofilament wefts with hollow monofilaments of the same diameter in a dryer fabric, the mass of material used per unit area of fabric can be reduced, and a reduction in material costs can be realized. This is particularly important when expensive polymers, such as PPS and PEEK, are used to make the monofilaments.
Wide industrial looms, up to 15 meters in width, are used in the manufacture of dryer fabrics. The requirement to traverse such distances, in a minimum of time, with a shuttle that carries the weft strands, demands high levels of acceleration and deceleration of both the shuttle and the strand at each side of the loom. The weft strands used in modern dryer fabric designs, particularly single layer designs, can be relatively massive (from about 0.7 mm to about 1.2 mm in diameter). The inertial effects associated with the acceleration and deceleration of these large wefts can cause difficulties in weaving, resulting in fabric defects and lowered production.
For example, the monofilament can pull out of the shuttle upon acceleration, and thus not be carried across the entire width of the loom, creating a defect in the fabric called a "dropped weft". On deceleration of the shuttle at the opposite side of the loom, the monofilament can continue to traverse the loom after the shuttle has stopped, thus providing a length of monofilament that is greater than the width of the loom. On beat-up into the fabric, the excess length of monofilament is trapped in the fabric, creating a defect called a "double weft". One method of reducing defects such as these, which are caused by inertial effects, is to reduce the mass of the solid monofilament used as the weft strand by replacing it with a hollow monofilament of substantially the same overall diameter.
Other embodiments of the invention may be made using the principles claimed herein. The specific embodiments should not be considered as limitations of the invention. | A paper machine dryer fabric includes hollow thermoplastic monofilaments to replace at least a portion of the wefts, also known as cross-machine direction strands. Fabrics including such monofilaments may be either a woven fabric, or a spiral fabric. The deformable nature of the hollow monofilaments decreaes the air permeability of the fabric, and in the case of spiral fabrics, improves monofilaments retention within the helical coils between the hinge yarns. The hollow monofilaments have a solidity in the range of from about 60% to about 75%. A suitable thermoplastic is polyethylene terephthalate. Hollow monofilaments do not have the disadvantages of other deformable yarns, such as spun yarns, multifilament yarns or plied monofilament yarns, each of which tend to hold and entrap within their structure both water and foreign matter. | 3 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method for improvement in diuresis which comprises administering a cyclodextrin or a derivative thereof to a subject.
Such improvement is required in the situation in which subjects show e.g. anuria or oliguria.
Anuria refers to a state wherein daily micturination is less than 100 ml and oliguria to a state wherein daily micturination is between 100 and 400 ml. Anuria and oliguria include those of prerenal, renal and prostrenal nature.
Prerenal anuria is caused by decrease in the renal bloodstream and originated from cardiac insufficiency, cirhosis, dehydration, shock etc. as the incentive. Renal oliguria is caused by different renal diseases. Acute nephritis and nephrotic syndrome are due to reduced glomerular filtration and enhanced tubular resorption of sodium ion and water. Acute renal insufficiency (acute tubulorrhexis) is principally caused by reduced glomerular filtration.
Since anuria and oliguria destroy the equilibrium in the body fluid and may be the causes leading to edema, uremia, cardiac insufficiency, hypertensive encephalopathy, retinitis etc., treatment of them is required.
Moreover, even in the case where the the amount of urine is normal, diuretics are often used in the treatment of cardiovascular diseases or renal diseases hypertension, edema etc.
As a result of extensive studies about the properties of cyclodextrin and their derivatives which have been used only as a complexing agent in the pharmaceutical field, the present inventor discovered that these compounds have beneficial diuretic action.
SUMMARY OF THE INVENTION
In a first aspect, the present invention provides a method for improvement in diuresis which comprises administering, to a subject in need of such improvement, a cyclodextrin or a derivative thereof (hereinafter, referred to as the compound used in the invention) in an amount effective to cause such improvement.
In a second aspect, the present invention provides a use of a cyclodextrin or a derivative thereof for the manufacture of a medicament for improvement in diuresis.
In a third aspect, the present invention provides a pharmaceutical composition for improvement in diuresis comprising a cyclodextrin or a derivative thereof in association with a pharmaceutically acceptable carrier, diluent or excipient.
DETAILED DESCRIPTION OF THE INVENTION
As used herein, the term "diuresis" refers to increased extracorporeal excretion of water, electrolytes, final metabolites etc. Usually, such excrition results in increase in the amount of urine. The compounds used in the invention have an action of increasing water secretion and secreting electrolytes. Increase in creatinine clearance (glomerular filtration) has also been confirmed indicating that the compounds used in the invention have also a action of increasing renal blood stream and glomerular filtration. The compounds used in the invention are indicated for the treatment of renal hypofuction, anuria, oliguria, hypertension of various etiologies, edema derived from various causes, promotion of drug excretion when drug intoxication is occurred, adjustment of the pressure and amount of aqueous humor or cerebrospinal fluid etc. Also, the compounds used in the invention are indicated for treatment of renal insufficiency by e.g. acute tubulorrhexis, necrosis of renal cortex etc. and nephritis.
The term "treatment" includes prevention, cure and relief of disease and arrest or relief of development of disease.
The term "cyclodextrin" includes α-cyclodextrin, β-cyclodextrin and γ-cyclodextrin.
The term "derivatives" used in conjunction with the term cyclodextrin refers to compounds in which at least one atom selected from hydrogen, oxygen or carbon in the cyclodextrin molecule is replaced by an atom or a group of atoms ordinarily present as a substituent in this kind of organic compounds (saccharides). These derivatives include etherified cyclodextrins, branched cyclodextrins, acylated cyclodextrins and sulfur-containing cyclodextrins.
Said etherified cyclodextrins include (lower)alkylcyclodextrins such as methylcyclodextrin, ethylcyclodextrin, propylcyclodextrin, dimethylcyclodextrin, trimethylcyclodextrin etc., (lower)alkenylcyclodextrins, hydroxy(lower)alkylcyclodextrins such as hydroxyethylcyclodextrin, hydroxypropylcyclodextrin etc., (lower)alkoxy(lower)alkylcyclodextrins, aralkylcyclodextrins such as benzylcyclodextrin etc., halo(lower)alkylcyclodextrins such as chloroethylcyclodextrin etc., and cylodextrinepichlorohydrine copolymer and so on. These may be etherified cyclodextrins in which one, two or three hydroxy groups in any of the glucose units of the cyclodextrin molecule are converted into ether.
Said branched cyclodextrins include glucosylcyclodextrin, maltosylcyclodextrin etc.
Said acylated cyclodextrins include (lower)alkanoylcyclodextrins such as formylcyclodextin, acetylcyclodextrin etc., aromatically or heterocyclically acylated cyclodextrins such as benzoylcyclodextrin, nicotinoylcyclodextrin etc.
Said sulfur-containing cyclodextrins include sulfonated cyclodextrins etc.
The derivatives of cyclodextrin include also derivatives in which two or more of derivatizations selected from etherification, branching, acylation and sulfuration are co-existing.
These derivatives are known or can be prepared by a method similar to that for the known derivatives.
While the dosage of cyclodextrin or derivatives thereof will vary depending on age, weight, condition of particular subject, desired therapeutic effect etc., satisfactory effects will generally be obtained with the dosage of 1 μg/kg to 500 mg/kg, preferably 10 μg/kg to 50 mg/kg, administered once a day or 2 to 4 divided doses a day or as a sustained form. Administration may be effected by injection etc.
For administration, the compound used in the invention can be given in the form of conventional pharmaceutical preparation which contains said compound, as an active ingredient, in admixture with a pharmaceutically acceptable carrier such as organic or inorganic, solid or liquid excipients suitable for the desired mode of administration such as injection. Such preparation may be in a solid form such as solid from which a solution can be made up before use, etc. or in a liquid form such as solution, emulsion, suspension, etc. Said carrier includes starch, lactose, glucose, sucrose, dextrin cellulose, paraffin, aliphatic glyceride, water, alcohol, acacia etc. The above preparation may also contain auxiliary substance, stabilizer, emulsifier, lubricant, binder, pH-adjuster, isotonic agent and other conventional additives added as necessary.
The present invention is illustrated in more detail by way of the following Examples and Test Examples.
EXAMPLE 1
______________________________________Dimethylcyclodextrin 100 mgPhysiological saline q.s. to 10 ml______________________________________
The above ingredients are brought into solution by conventional way to form an injectable solution.
TEST EXAMPLE 1
Beagle dogs (weight: 7-8 kg) were alloted into groups. The animals were kept away from foods and water before 17 hours of administration of test compositions. The Ringer solution (25 mg/kg) was intravenously administered over one hour (for water-loading) and, after 30 minutes, a solution of dimethyl-α-cyclodextrin [a mixture mainly pentakis[2,6-di-O-methyl)-mono(2,3,6-tri-O-methyl)-α-cyclodextrin; hereinafter referred to as DMCD] (5 mg/kg) in the Ringer solution was intravenously administered. The control group received the same amount of Ringer solution.
Urine samples were collected using catheter at 30 minutes intervals and assayed for the amount of electrolytes (sodium, potassium and chloride). Also, the total amounts of excretion of each items, respectively, from the time of administration and up to 120 minutes thereafter were measured. The results are shown in Table 1. In addition, urine and serum creatinine concentrations were measured at appropriate time from which values of creatinine clearance (glomerular filtration) were calculated. The results are shown in Table 2.
TABLE 1______________________________________Urine(ml) Na(mEq) K(mEq) Cl(mEq)______________________________________Control 26.9 ± 19.3 4.4 ± 2.2 1.3 ± 0.5 4.9 ± 1.7(n = 6) (S.D.)DMCD **61.3 ± 3.6 *12.7 ± 3.0 *3.8 ± 1.1 *13.6 ± 3.1(n = 3)______________________________________ Dannet Method: *P < 0.01, **P < 0.05
TABLE 2______________________________________Creatinine Clearance (ml/kg/min) After: 60 min 120 min______________________________________Control 2.47 ± 0.76 2.67 ± 0.74(n = 6) (S.D.)DMCD **3.83 ± 0.63 3.50 ± 0.29(n = 3)______________________________________
TEST EXAMPLE 2
Male rats (Crj; weight 100-150 g) were alloted into groups. After receiving test compositions, they were bred in cages. Cumulative amount of urine was weighed after 3 hours without food and water (3 hr Urine) and after additional 21 hours with food and water (21 hr Urine), giving 24 hr urine as the total amount. Further, 21 hr urine was assayed for osmotic pressure using an osmometer (OM-801, Asahi Lifescience). As the test compounds were used DMCD, hexakis(2,6-O-methyl-α-cyclodextrin [purified from DMCD as a mixture; hereinafter referred to as Compound I] and pentakis(2,6-di-O-methyl)-mono(2,3,6-tri-O-methyl)-α-cyclodextrin [purified from DMCD as a mixture; hereinafter referred to as Compound II], dissolved in the physiological saline and administered at a rate of 5 mg/kg via a caudal vein. The control group received the physiological saline. The results are shown in Table 3.
TABLE 3______________________________________ Urine(ml) Osmotic Pressure(osm/kg)______________________________________Control 10.5 ± 1.3 2.23 ± 0.55(n = 6) (S.D.)DMCD 1 mg/kg 16.0 ± 2.2 1.40 ± 0.17(n = 3)Compound I 14.0 ± 4.0 1.65 ± 0.411 mg/kg(n = 3)Compound I 15.4 ± 1.4 1.41 ± 0.235 mg/kg(n = 3)Compound II 14.0 ± 5.2 1.68 ± 0.652 mg/kg(n = 3)Compound II 16.4 ± 0.8 1.31 ± 0.395 mg/kg(n = 3)______________________________________
The above results indicate that the compounds used in the invention have excellent diuretic action. | A method for improvement in diuresis which comprises administering, to a subject in need of such improvement, a cyclodextrin or a derivative thereof in an amount effective to cause such improvement. | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This application relates to an automatic opening and/or closing apparatus adapted for use in association with a sliding door to a medium-sized automobile such as a small bus which is used as a means of public transportation.
2. Description of Related Art
Normally, a medium-sized public bus has a manually-operated sliding door. This manually-operated sliding door is very inconvenient for opening and/or closing. Especially, the operation of this manually-operated sliding door is beyond the capacity of most little children. Therefore, a driver himself has to get off the bus and close the door just after the children has got on the bus. Furthermore, there are frequent occasions when the driver has to open the door in advance before the bus stops, which results in an unexpected accident. In addition to these, there is a likelihood that the door would be locked imperfectly, which results in undesired opening of the door of itself while the bus is running.
OBJECTS
A principal object of the invention is the provision of an automatic opening and/or closing apparatus in which the above disadvantages are overcome.
It is another object of the present invention to provide an automatic sliding door which is simple in the operation of the opening and/or closing such that a driver need not leave his seat when it is desired to open and/or close the door.
Other objects and further scope of applicability of the present invention will become apparent from the detailed descriptions given herein; it should be understood, however, that the detailed descriptions, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent from such descriptions.
SUMMARY OF THE INVENTION
According to the present invention, the opening and/or closing operation of the sliding door is achieved by providing a roller chain which is moved by a sprocket gear. The sprocket gear operates by a reduction gear which is driven by a motor.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete understanding of the invention can be obtained by reference to the accompanying drawings in which:
FIG. 1 is an exploded perspective view of a portion of the automatic sliding door of the present invention with partially broken away;
FIG. 2 is a cross-sectional view taken along line A--A showing the assembly of the components;
FIG. 3 is a cross-sectional view showing automatic sliding door of the present invention in the locked position;
FIG. 4 is a cross-sectional view showing a lock in the released position to open the sliding door of the present invention; and
FIG. 5 is a cross-sectional view showing the sliding door of this invention in the open position by means of a chain belt.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings, an electric-powered reducer 1 is supported by a bracket 2 which is fixed to a body (1) of an automobile. The bracket 2 has guide bars 3 and 3' which pass through the electric-powered reducer 1 for mounting the reducer 1 thereon. The reducer 1 engages a receiving member 5 by means of a rail 2'. The receiving member 5 is securely fixed to the inner face of a sliding door (b) and has horizontally extending upper and lower support plates 6 for receiving a roller chain 4 therebetween. Each of the support plates 6 is provided with elongated bores 7 and 7' at each end thereof. The roller chain 4 is moveably mounted between the upper and lower support plates 6 by means of hinge member 8 and 8' and movable in the left-right direction. One hinge member 8 is supported in a bush 9 and has a connection portion 10 to which is connected a wire roped. The wire rope d is connected to a lock C. A sprocket gear 11 is connected to the reducer 1. With this arrangement, the roller chain 4 is moved by the sprocket gear 11 causing the sliding door to be opened.
A numeral 12 denotes a sensing switch; 13, bevel gear; 14, support member; 15, worm gear; and 15, bolts.
In operation (see FIG. 3), a switch or button (not shown) is on with the sliding door closed, to drive the electric-powered reducer 1. With the driving of the electric-powered reducer 1, the sprocket gear 11 rotates clockwise causing the roller chain 4 to move the bush 9 as shown in FIG. 4. Simultaneous with the movement of the bush 9, the connection portion 10 moves while pulling the wire rope d, which results in the release of the lock c. As shown in FIG. 5, after the lock is released, the sprocket rotates continuously, thereby the roller chain 4 moves in the right direction, causing the sliding door to be opened.
The opening operation of the sliding door stops when the switch or button is depressed or one portion of the receiving member contacts the sensing switch 12.
As shown in FIG. 5, the movement of the sliding door toward an outside length L is simply accomplished by moving along the guide bars 3 and 3'. Even in this condition, the sliding door keeps engaging with the receiving member 4 by means of the rail 2' and moves only in the left-right directions.
An extra button (not shown) is provided and the movement of the sliding door from the closed position to the open position is achieved in a reverse manner by simply depressing the extra button. The depression of the button causes the motor of the reducer to rotate in the opposite direction. As the above-described construction, the automatic sliding door of the present invention operates electronically only by means of the buttons and children can get on and/or off the bus with safety. Besides, the automatic sliding door of the present invention is simple and thus, inexpensive to manufacture. | An automatic opening and closing apparatus for use in a sliding door to an automobile, such as a bus used as a means of public transportation, includes a roller chain which is moved by a sprocket gear operated by a reduction gear that is driven by a motor. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The Applicant hereby claims the benefit of his provisional application, Serial No. 60/461,956 filed Apr. 10, 2003 for LED Lamp.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to electric lamps and particularly to solid-state electric lamps. More particularly the invention is concerned with solid-state electric lamps held in enclosed in an atmosphere.
[0004] 2. Description of the Related Art Including Information Disclosed Under 37 CFR 1.97 and 1.98
[0005] LEDs are commonly used as light sources in a variety of lamp shapes. In general LEDs have been used as discrete elements, dispersed on an open surface. In this form the surrounding air naturally cools the LEDs. To achieve higher lamp intensity, the LEDs have to be clustered together. This increases the cumulative heat, which leads to the use of an associated heat sink. The size of the heat sink can be difficult accommodate in a lighting system. At the same time the size of heat sink can interfere with the light radiating from the lamp. There is then a need for a lamp with one or more LEDs as light sources that does not use, or can use a significantly smaller heat sink.
BRIEF SUMMARY OF THE INVENTION
[0006] An LED lamp may be formed from a solid-state light source mounted on a support structure. A light transmissive envelope encloses the light source and support structure, and an electrical input lead and return lead pass into the envelope providing electrical energy to the light source. A low molecular weight gas fill, such as helium or hydrogen, is enclosed in the envelope to be in thermal contact with the light source. The thermal conductivity of the fill gas cools the LED source and does not interfere with light transmission.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0007] [0007]FIG. 1 shows a schematic, cross sectional view of an LED lamp.
DETAILED DESCRIPTION OF THE INVENTION
[0008] The LED lamp 10 comprises a solid-state light source 12 mounted on a support structure 14 . The light source 12 and support structure 14 are enclosed by a light transmissive envelope 16 . Electrical input lead 18 and return lead 20 pass into the envelope 16 , providing electrical energy to the light source 12 . A low molecular weight, thermally conductive cooling gas 22 is enclosed in the envelope 16 to be in thermal contact with the light source 12 .
[0009] The solid-state light source 12 may be an LED or a solid-state laser. Preferably it is a naked chip mounted directly on a thermally conductive support (“chip on board”), and the chip is not coated or sealed by an epoxy or other coating material. The openly exposed light source 12 then has direct contact with the surrounding cooling gas 22 .
[0010] The support structure 14 may comprise metal support rods, or a common stem type support. Given the small size of the LED light source 12 and the relatively large size of the support structure 14 ; the mechanical leverage exerted on the light source 12 may be excessive. The preferred support structure 14 then includes a constraint 24 between the input lead 18 and the return lead 20 so bending and twisting moments between the leads 18 , 20 are not or are only minimally transmitted through the light source 12 . An electrically insulating bridge, glass rod or stem support may be used. Preferably the mechanical support structure 14 is as thermally conductive as possible. Preferably both the electrical input lead 18 and return lead 20 are highly thermally conductive. Copper or a similarly high thermal conductivity material may be used as the electrical input lead 18 and return lead 20 . The support structure 14 may additionally include cooling features such as fins, plates or extended surfaces that spread or radiate heat over a greater area than simple straight rods. It is understood that large volume rods or similarly large mass, and large surface area supports may be used. The one electrical connector may include a reflector 26 or similarly mirrored body, wherein the reflector 26 also acts as a heat sink and thermal radiator. FIG. 1 shows a naked LED chip mounted on a thermally conductive plate, while two thermally conductive electric leads 18 , 20 are coupled to the light source 12 , such as an LED chip.
[0011] The light transmissive envelope 16 encloses the light source 12 and support structure 14 . The preferred envelope 16 is made of glass, as it is inexpensive, easily molded into useful shapes, and can contain most low molecular weight gases to a reasonable degree. Preferable the exterior surface area of the envelope 16 is much larger than the surface area of the light source 12 . Preferably the ratio of the exterior surface area of the envelope to the surface area of the light source 12 is greater than the ratio of the light source 12 's temperature in Celsius to the exterior (ambient) temperature in Celsius, (typically less than 35 degrees Celsius). The envelope 16 interior need not necessarily be a particularly clean environment. It only needs to contain the cooling gas 22 at the preferred pressure. In standard incandescent lamps, it is important to keep water and oxygen away from the hot filament. Epoxies are used to coat the LED in many common constructions, but the epoxies interfere with heat conduction and light projection. The envelope 16 environment need only be as clean as that provided by the epoxy, so as to provide the same relative degree of protection from any infringing water, oxygen or other possibly injurious material. The envelope 16 may be sealed by press sealing as is known in the industry, but it may also be sealed mechanically with a mechanical plug, hardenable cement (silicon rubber, epoxy, saurising cement or similar), coating or similar material to fill to close the a fill gas opening. The seal only needs to retain the cooling gas in place at the preferred pressure. The seal may be a simple plug 28 in the envelope 16 . A press seal, albeit more expensive, is preferred.
[0012] The electrical input lead 18 and return lead 20 pass into the envelope 16 providing electrical energy to the light source 12 . These input lead 18 and return lead 20 may be straight rods sealed to the glass envelope 16 as is typical of a stem type. They may comprise a sealed foil input lead 18 and return lead 20 as is typical of tungsten halogen lamp assemblies. The seal need only be sufficient to reasonably contain the preferred gas 22 filling in the envelope 16 , at a preferred pressure for useful life for the lamp; and to similarly keep injurious material out of the envelope. The choice of a metal lead and the glass envelope 16 is in part a matter of design choice to achieve a sufficiently good seal.
[0013] The thermally conductive gas 22 encloses the envelope 16 in thermal contact with the light source 12 . The preferred gas 22 filling is helium, but it could be hydrogen or other relatively molecularly lightweight gas 22 , meaning a gas with an average molecular weight that is ten percent less than the average molecular weight of air. Helium is approximately seven times more efficient as a heat conducting gas 22 , than is air. For pure heat conduction hydrogen even lighter and more thermally conductive, however can be explosive in some situations, so its use presents a theoretical danger. The preferred pressure is about 0.75×10 5 Pascals to 8.0×10 5 Pascals (0.75 to 8 atmospheres). If the pressure is too low, the fill gas effectively acts as an insulating vacuum, thereby defeating the intended purpose of using the gas 22 to actively conduct heat away from the light source 12 . If the fill pressure is too high, it offers the opportunity for the lamp to fail catastrophically, which is an undesirable result.
[0014] The envelope 16 may be supported by a base 30 . The base 30 includes a mounting to receive and retain the envelope 16 . The base 30 additionally includes one or more channels for receiving the exterior ends of the input lead 18 and the return lead 20 . The leads 18 , 20 are connected to the contacts as electrically isolated contact points for electrical connection in a correspondingly formed socket. The base 30 may be a pin, threaded, wedge or similarly shaped socket and may even be configured to fit existing sockets. Conforming the incoming power to that needed by the one or more LED's may require circuitry 32 as is known in the art that may be enclosed in the base 30 . For example the base 30 may have a threaded base 30 with contacts typical of a threaded miniature bulb, for example one used in a flashlight. Adapting the gas filled envelope to the various bases (threaded, pin, wedge, bayonet, etc.) and sockets is considered to be within the skill in the art of lamp making.
[0015] It is understood that the use of only one solid state light source has been shown, a plurality may be mounted in the gas filled envelope, and that the gas cooling effect is more relevant where the number of sources is high or they are closely mounted so as to have a relatively high heat source density. While there have been shown and described what are at present considered to be the preferred embodiments of the invention, it will be apparent to those skilled in the art that various changes and modifications can be made herein without departing from the scope of the invention defined by the appended claims. | LED lamps may be effectively cooled with an atmosphere of high thermal conductivity. Hydrogen and helium are transparent gases with high thermal conductivity. Enclosing an LED light source in such a gas environment efficiently conducts heat from the LED thereby enhancing the LED's output and extending the LED's life. | 5 |
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation of co-pending U.S. application Ser. No. 11/420,348 filed May 25, 2006, and entitled “AN OPTIONALLY ATTACHABLE, PERMANENTLY FIXED TWO PIECE CONTAINER CAP”.
All patents and publications described or discussed herein are hereby incorporated by reference in their entirety.
BACKGROUND OF THE INVENTION
The present invention relates to a closure and container system, or closure and container assembly, for pharmaceuticals. The closure includes child resistant and non-child resistant configurations. The pharmaceuticals system can provide an obstacle for children to remove the closure from the container in the child resistant configuration, while allowing for the ready removal of the closure from the container in the non-child resistant configuration. The closure includes two separate pieces that are designed to be optionally attachable, yet permanently fixed once the pieces are attached. The decision to attach these pieces is preferably made by a person other than the manufacturer, supplier, or distributor of the closure and container system.
There are many types of child resistant closure systems described in the art. An example of a particular type of child resistant closure system is proposed in U.S. Pat. No. 5,449,078, which relates to a combination of a container and safety cap. While many child resistant caps effectively provide protection against the danger of small children being able to remove potentially harmful contents, e.g. pills, from vials or other containers, they also provide a problem for a considerable portion of the adult population that require medication but lack the manual dexterity or strength to remove the child resistant cap. This is of a particular concern to the elderly population or people suffering from arthritis and other disabling diseases.
The most popular type of child-resistant closure is known in the art as a continuous threaded, torque actuated child resistant closure. These caps involve the use of two parts, one of which rests above the other in an axial configuration and which requires both a rotational and downward action to engage for removal. These are used in literally thousands of various applications and packaging configurations due to the universally understood push and turn mechanisms and ease of use and adaptation in a wide variety of automated filing lines and processes. They have become the most prominent and widely accepted solution for packaging requiring child resistant closures. Therefore, any invention designed to overcome the difficulty many senior members of the population experience when attempting to open child-resistant closures should preferably involve, as the basis of its design, a standard two piece, push and turn, torque actuated continuous threaded closure due to their popularity and universal use.
This particular problem has been addressed by the development of closure systems having a child resistant mode and a non-child resistant mode such that, in the non-child resistant mode, the closures are more easily opened by adults. Another example of such a closure is disclosed in U.S. Pat. No. 5,579,934, (the '934 patent). The '934 patent proposes a container closure that is selectively manipulatable between a configuration which resists opening by children and a configuration which may be easily opened without special manipulation of the closure. Specifically, the closure is manipulated into its non-child resistant mode by “pressing down” on the central portion of the top surface of the closure. Although the aforementioned closure provides an advance in the art of protection against the danger of small children being able to remove it from vials or other containers, a certain portion of the adult population lack the manual dexterity or strength to “press down” the central portion of the top surface of the closure so as to manipulate the closure from its child resistant configuration to its non-child resistant configuration. This manipulation or “pushing down” also represents a problem for people with long fingernails.
Other reversible or convertible child resistant closures have been proposed to address this problem. However, these solutions, while making the closure easier to convert into the non-child resistant configuration, increase the risk that the closures will inadvertently be converted into their non-child resistant configurations. Similarly, there is an increased risk that automated filling machines will inadvertently convert the closures into their non-child resistant configurations when applying the closure to the container.
The other form of pharmaceutical closures in the prior art that is convertible between child resistant and non-child resistant mode requires the use of two separate caps that are not designed to be integrated into a single cap. These prior art closures require that a user replace the non-child resistant cap with a child resistant cap, or vice a versa, in order for the closure to switch between child resistant and non-child resistant modes. This requires a pharmacy to maintain two inventories of caps adding costs to the end price for consumers.
Further, the closures of the type disclosed in the '934 patent cannot include a warning to the consumer once the closure has been converted to its non-child resistant configuration. This message is required by the Consumer Product Safety Commission (“CPSC”) to alert users that the closure has been converted into the non-child resistant configuration. Also, other reversible child resistant designs that do include the CPSC consumer warning cannot be used in automated dispensing equipment due to projections on their outer surface.
Furthermore, the prior art has shortcomings in the development of child resistant caps including two or more cap elements. For example, an inner cap element nested within an outer cap element and being equipped with an engaging device for rotatably coupling one cap element to the other, as proposed in U.S. Pat. No. 4,520,938, has a substantial risk that children could separate one cap from the other (“shelling”) thereby disabling the child resistance mode of operation, especially when the outer cap is made of resilient material such as plastic. Once shelled, there is usually no other safeguard to prevent access to the contents of the container.
Additionally, the multiple element prior art pharmaceutical caps that allow conversion between child resistant and non-child resistant configurations are all provided preassembled. For example, any of the prior art pharmaceutical caps that combine one or more elements into a single cap are provided, or sold, as complete, assembled units and not as individual elements. As such, these prior art convertible pharmaceutical caps require the purchase of an assembled, two element cap regardless of whether or not a convertible cap is actually desired. The end user does not have a choice of the characteristics of the caps. This increases the cost of the pharmaceutical cap, which is either passed on to the consumer or absorbed by the manufacturer.
In light of the foregoing, there is a need for a closure and container system that has both a child resistant and non-child resistant mode. The non-child resistant mode is preferably easy opened without special manipulation, while in the child-resistant mode the system resists any conversion between the two modes. The system should be able to achieve a child-resistant mode that can be optionally obtained by a party other than the manufacturer, such as the pharmacy or the end user, but once obtained should be substantially permanently fixed in that mode. It is not currently contemplated, in either the literature or the industry, to provide pharmaceutical caps to pharmacies or end users as unattached separate elements designed to be integrated into a single cap at the option of the pharmacies or end users.
BRIEF SUMMARY OF THE INVENTION
The present invention is directed to a closure that can substantially obviate one or more of the problems due to limitations and disadvantages of the related art. Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be further realized and attained by the apparatus particularly pointed out in the written description and claims hereof as well as in the appended drawings.
To achieve these and other advantages and in accordance with the purposes of the invention, as embodied and broadly described, pharmaceutical storing and dispensing device having a closure and a container is taught. The pharmaceutical storing and dispensing device includes a child resistant mode and a non-child resistant mode between the container and the closure.
The closure comprises a non-child resistant element, or cap, shaped to removeably engage the container and a child-resistant element, or cap, shaped to be permanently fixed to the non-child resistant cap. The non-child resistant cap and child resistant element are provided separately based upon consumer demand and desired cap characteristics.
A method of providing a pharmaceutical container and a pharmaceutical cap for the container is taught. The method comprises providing at least one container shaped to hold pharmaceuticals, providing at least one non-child resistant cap shaped to removably engage the container, and providing at least one unattached child resistant element shaped to be permanently fixed to the non-child resistant cap.
A method of selling pharmaceutical containers and pharmaceutical caps for the containers to a pharmacy is also taught. The method comprises selling a plurality of containers shaped to hold pharmaceuticals, selling a plurality of non-child resistant caps shaped to removably engage the containers, and optionally selling a plurality of unattached child resistant elements shaped to be permanently fixed to the non-child resistant caps.
In one embodiment, the non-child resistant cap and child resistant element can be used in intentionally varying quantities such that the quantity of child resistant elements used is less than the quantity of non-child resistant caps used. The containers and non-child resistant caps can be delivered in a first quantity while the child resistant elements can be delivered in a second quantity which is less than the first quantity. This intentional separation in supply or use is facilitated by the capability of a subsequent party, such as a pharmacy, to determine if one of the child resistant elements will be permanently fixed to one of the non-child resistant caps in conjunction with the supply of the pharmaceutical system to the ultimate consumer.
The current invention further includes allowing the pharmacy to determine if or when the child resistant element is permanently fixed to one of the non-child resistant caps. This determination can occur at the pharmacy and can be individual for each child resistant element. Additionally, this determination can be by the actual person wanting the pharmaceuticals to be placed in a container, such as the end pharmaceutical customer, or the person having the prescription filled.
Additionally, if the original quantitative determination of the amount of child resistant elements needed is inaccurate, a third quantity of child resistant elements can be subsequently delivered to meet any additional need or demand for a complete child resistant pharmaceutical system at a given location.
As such, it is a general object of the present invention to provide a method of delivering a pharmaceutical system including pharmaceutical containers and pharmaceutical caps for the containers to the pharmacy.
Another object of the present invention is to deliver a pharmaceutical system having a container and at least two cap elements that are unattached when the pharmaceutical system is delivered.
Still another object of the present invention is to provide varying quantities of independent elements optionally attachable to comprise a pharmaceutical cap and corresponding to a given quantity of pharmaceutical containers.
Another object of the present invention is to supply child resistant elements separately from non-child resistant elements, wherein both of the elements are to be used in conjunction with a pharmaceutical container.
Yet another object of the present invention is to supply a non-child resistant cap that cost less than an assembled convertible dual purpose child resistant/non-child resistant cap for a given pharmaceutical container
Another object of the present invention is provide a pharmaceutical cap having at least two attachable elements wherein the elements are sold in varying quantities based upon pharmaceutical consumer needs or desires.
Still another object of the present invention is to provide a pharmaceutical system that allows the end pharmaceutical user to determine whether the system will be child resistant.
Another object of the present invention is to provide a pharmaceutical system that allows a pharmacy to decide whether the system will be child resistant.
Another object of the present invention is to provide a pharmaceutical system comprising a container, a child resistant element and a non-child resistant cap wherein the child resistant element can be selectively and permanently fixed to the non-child resistant cap to make the pharmaceutical system child resistant.
Other and further objects, features and advantages of the present invention will be readily apparent to those skilled in the art upon reading of the following disclosure when taken in conjunction with the accompanying drawings.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.
The accompanying drawings are included to provide a further understanding of the invention and are incorporated in and constitute part of this specification, illustrate several embodiments of the invention and together with the description serve to explain the principles of the invention.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1A is a flowchart indicating an example of the delivery methodology associated with the current disclosure.
FIG. 1B is a flowchart of a delivery methodology as disclosed herein.
FIG. 2A is a cross-sectional view of a pharmaceutical system including a container with a non-child resistant cap engaging a child resistant cap.
FIG. 2B is a side view similar to FIG. 2A .
FIG. 2C is a perspective view similar to FIGS. 2A-B .
FIG. 3A is a top view of a container made in accordance with the current disclosure.
FIG. 3B is a bottom view of the container in FIG. 3A .
FIG. 3C is a cross-sectional view of the container similar to FIGS. 3A-B .
FIG. 3D is a perspective view of the container shown in FIGS. 3A-C .
FIG. 4A is a bottom perspective view of a child resistant element made in accordance with the current disclosure.
FIG. 4B is a top perspective view of the child resistant element of FIG. 4A .
FIG. 4C is a top view of a child resistant element shown in FIGS. 4A-B .
FIG. 4D is a cross-sectional view taken along line D-D of FIG. 4C .
FIG. 4E is a cross-sectional view taken along line E-E of FIG. 4C .
FIG. 4F is a cross-sectional view taken along line F-F of FIG. 4C .
FIG. 4G is a side view of the child resistant element shown in FIGS. 4A-4F .
FIG. 5A is a top view of a non-child resistant cap made in accordance with the current disclosure.
FIG. 5B is a close-sectional view taken along line B-B of FIG. 5A .
FIG. 5C is a top perspective view of the non-child resistant cap shown in FIGS. 5A-5B .
FIG. 5D is a bottom perspective view of the non-child resistant cap shown in FIGS. 5A-5C .
FIG. 5E is a side view of the non-child resistant cap shown in FIGS. 5A-B .
FIG. 5F is an alternate top perspective view of the non-child resistant cap shown in FIGS. 5A-B .
DETAILED DESCRIPTION OF THE INVENTION
Included herein is a method of delivering pharmaceutical containers 12 and pharmaceutical caps 14 and 16 for the containers 12 to a pharmacy. The container 12 and caps 14 and 16 can be described as a pharmaceutical system 10 . The method includes providing at least one container 12 to hold pharmaceuticals, providing at least one non-child resistant cap 14 (NCR Cap) shaped to removeably engage the container 12 , and providing at least one unattached child resistant element 16 , or child resistant cap 16 , (CR Element) shaped to be permanently fixed to the NCR cap 14 .
A method of selling pharmaceutical containers 12 and pharmaceutical caps, comprising 14 and 16 , for the containers 12 to a pharmacy is also taught. The method comprises selling a plurality of containers 12 shaped to hold pharmaceuticals, selling a plurality of non-child resistant caps 14 shaped to removably engage the containers 12 , and optionally selling a plurality of unattached child resistant elements 16 shaped to be permanently fixed to the non-child resistant caps 14 . The CR Elements 16 are designed to be integrated with the NCR Cap 14 and preferably include a design that lacks the capacity to be attached to the container 12 independent of the NCR Cap 14 .
The steps of providing or selling the plurality of unattached CR Elements 16 is preferably based upon the use of those CR Elements 16 by the pharmacy or pharmaceutical user. This use can be quantified by the fact that one of the NCR caps 14 is used with each container 12 while one of the CR Elements 16 is optionally used based upon consumer driven demand.
As such, the second quantity of CR Elements 16 can be less than the first quantity of NCR caps 14 and containers 12 . For example, in one embodiment the quantity of CR Elements 16 is approximately less than 50% of the quantity of NCR Caps 14 . In alternate embodiment, the second quantity of CR Elements 16 is approximately less than 20% of the first quantity of NCR caps 14 . Additionally, a third quantity of CR Elements 16 can be delivered subsequently to the delivery of the second quantity such that the third quantity of the CR Elements 16 is less than the second quantity of CR Elements 16 .
These variances in quantities are facilitated by the option of a subsequent party, such as the pharmacy, pharmacist, pharmaceutical customer, medical prescription patient, and the like, to decide whether the pharmaceutical system 10 has child resistant capabilities. Namely, an individual substantially unrelated to the manufacture of the pharmaceutical system 10 has the ability to decide whether the individual elements of pharmaceutical system 10 are assembled. This ability to decide facilitates the ability of a person or entity to establish post-manufacture, and more specifically, after the pharmaceutical system 10 leaves the manufacturer's control, whether the pharmaceutical system 10 will have child resistant characteristics.
Alternately stated, at least the first user of the pharmaceutical system has the capability of deciding whether to assemble the child resistant element 16 with the non-child resistant cap 14 in order to make a pharmaceutical system 10 comprising a container 12 , non-child resistant cap 14 and child resistant element 16 . This combination would make the pharmaceutical system 10 child resistant. Alternately, at least that first user of the pharmaceutical system can decide not to attach the child resistant element 16 to the non-child resistant cap 14 thus making the pharmaceutical system not possess child resistant characteristics and comprise the container 12 and the non-child resistant cap 14 without the child resistant element 16 .
The current method is further enhanced by the fact that at least the first user of the pharmaceutical system 10 after manufactured control has been relinquished has the ability to determine the characteristics of the pharmaceutical system 10 . For example, a pharmacy can decide to preassemble NCR Caps 14 on containers 12 and decide on an individual basis whether any of those preassembled combinations will have a child-resistant element 16 . Additionally, the determination can be by the pharmaceutical patient who can choose not to have child resistant characteristics in their pharmaceutical system due to a lack of small children at their home that could be exposed to a potential health risk by the pharmaceuticals in the pharmaceutical system 10 or the inability to open a child resistant system.
An advantage of the methods taught by this disclosure includes the fact that the pharmacy can reduce costs by only supplying a child resistant pharmaceutical system when desired by the ultimate consumer. This reduces the amount of overhead to the pharmacy, storage capacity need for the pharmaceutical systems, and the material amounts associated with each pharmaceutical system 10 , thereby reducing the overall costs to the pharmacy.
Additionally, an end user that has difficulty opening a child resistant pharmaceutical system can option to not have this characteristic. For example, this is very useful for pharmaceutical patients that suffer from arthritis in their hands, have other physical ailments that do not facilitate operating the child-resistant mechanisms on pharmaceutical systems, or otherwise do not need a system with child resistant characteristics.
However, if a child resistant pharmaceutical system is desired, the child resistant element 16 is designed to be permanently fixed to the non-child resistant cap 14 . This reduces any unwanted shelling or removal of the child resistant element 16 from the non-child resistant cap 14 thereby facilitating the safe characteristics of a child resistant pharmaceutical system 10 and protecting at risk individuals from unwanted access to the pharmaceuticals contained therein.
These inventive methods are facilitated by the construction of the pharmaceutical system 10 . In a preferred embodiment the NCR Cap 14 , as exampled in FIGS. 5A-5F , includes an attachment device 18 , which can be a single thread, double thread, one or more beads, or other similar attachment methods known in the art. The attachment device 18 interacts with the fastener 20 on the container 12 in conventional manners to secure the NCR Cap 14 to the container 12 . The bottom 22 of NCR Cap 14 can rest on the angular ring 24 on the neck 26 of the container 12 . Alternately, and more preferably, the bottom 22 can be suspended above the angular ring 24 by the attachment device 18 and the fastener 20 . The NCR Cap 14 can include a gripping element 28 , such as knurlments, to provide a gripping surface for opening the NCR Cap 14 .
The child resistant element 16 is exampled in FIGS. 4A-4G . The CR Element 16 can include gripping elements 30 , which can also be described as knurlments, used to facilitate the rotation of the CR Element 16 . Additionally, indicia 32 can be printed on the top surface 34 of the CR Element 16 , wherein the indicia give instructions on how to open the CR Element 16 . The CR Element 16 is shown in the Figures having an open top 34 , but alternately can have a solid top not allowing view of the NCR Cap 14 . The rim 36 shown in FIGS. 4A-4F can be used to cover indicia (not shown) on the NCR Cap 14 . Those indicia on the NCR Cap 14 can include such warnings as “Caution Not Child Resistant.” The rim 36 can be designed to cover the indicia on the NCR Cap 14 . The top 34 , if solid, can cover any indicia on the NCR Cap 14 when the CR Element 16 and NCR Cap 14 are attached.
The CR Element 16 includes at least one protrusion 38 , which can be described as an internal tab, engaging the bottom 22 of the NCR Cap 14 . The internal tabs 38 are angled and include a substantially flat surface 40 that engages the bottom 22 of the NCR Cap 14 to fix the CR Element 16 to the NCR Cap 14 . In a preferred embodiment there are four internal tabs 38 spaced around the internal wall 42 of the CR Element 16 . The angled portion 39 of the tabs 38 facilitates the CR Element 16 traversing the external wall (referring to wall with knurlments 28 thereon) of the NCR Cap 14 .
The height of the NCR Cap 14 can be less than the distance from the flat surface 40 to the top 34 . This spatial configuration facilitates the selective engagement of teeth 46 positioned near the engagement between the internal wall 42 and top 34 of the CR Element 16 . The teeth 46 interact with corresponding teeth 48 on the NCR Cap 14 . The teeth 48 of the NCR Cap 14 are positioned opposite the bottom 22 and near the top 50 of the NCR Cap 14 . The teeth 48 can be an extension of the knurlments 28 , or can be separate items on the NCR Cap 14 .
In operation, since the height of the NCR Cap 14 is less than the distance between the flat surface 40 and the teeth 46 of the CR Element 16 , simply trying to turn the CR Element 16 without a depressive force will facilitate a traversing motion of the teeth 46 across the teeth 48 . Without pressure applied in a downward direction on the CR Element 16 , the teeth 46 CR Element 16 will not engage the teeth 48 on the NCR Cap 14 . As such the NCR Cap 14 , which is attached to the container will not rotate and open. However, when the downward pressure is applied to the CR Element 16 the teeth 46 engage the teeth 48 of the NCR Cap 14 to rotate and become disengaged from the container 12 to allow access to the pharmaceuticals therein.
An advantage of this current system is the fact that the conversion of a pharmaceutical system 10 from a system having non-child resistant characteristics to a system having child resistant characteristics does not require the replacement of parts within the pharmaceutical system 10 . The current disclosure teaches that the selective addition of a child resistant cap that can be affixed to a non-child resistant cap adds to the pharmaceutical system a child resistant characteristic.
Thus, although there have been described particular embodiments of the present invention of a new and useful An Optionally Attachable, Permanently Fixed Two Piece Container Cap, it is not intended that such references be construed as limitations upon the scope of this invention except as set forth in the following claims. | A pharmaceutical storing and dispensing device including a child resistant mode and a non-child resistant mode between the container and the closure. The closure comprises a non-child resistant cap shaped to removeably engage the container and a child-resistant cap shaped to be permanently fixed to the non-resistant cap. The non-child resistant cap and child resistant cap are provided in intentionally varying quantities such that the quantity of child resistant caps is less than the quantity of non-child resistant caps. | 1 |
FIELD OF THE INVENTION
[0001] This invention generally relates to a backend service. More particularly, the invention relates to a messenger based system and method to access a service from a backend system.
BACKGROUND OF THE INVENTION
[0002] Many computer systems include components that can be characterized as a backend system and frontend, respectively. Typically, the backend stores and processes data, among other services, and the frontend is responsible for presenting the backend data and allowing users to manipulate the data when applicable. For example, the R/3 system from SAP AG is a backend system that is capable of handling many different types of data processing and management services in an enterprise resource planning (ERP) environment, such as services related to customer relationship management (CRM). Moreover, SAP AG provides a business warehouse (BW) system that offers data repository management services that can be used in connection with the backend system. For example, the BW system lets users formulate queries that can be run on various data repositories of backend data. The BW server also provides visual displays for presenting query results in formats that are most suitable for the various users of the system. These visual displays that present operational data to a user may be referred to as reports, because they are akin to a traditional paper-based business report.
[0003] One disadvantage with the mentioned existing systems and other backend systems is that the report displayed to the user rarely has any useful connection to operational data in the backend. That is, if the user intends to go to the source for the report data, these systems seldom provide a convenient user navigation to the source data. For example, when the user is looking at a particular table in a report generated by a data repository management service, there is no convenient way for the user to navigate to the backend source data that was used in creating the table. Rather, the user has to identify the proper backend service that handles the operational data, and access the backend system to launch that service. Moreover, it may be necessary for the user to know navigation path of the service in the backend system and object key to access the data in the backend system.
[0004] The user may face similar problems when the user initiates a session for accessing a service and performing a task. The user usually accesses a service via a web interface, or an backend application login. However, in case of the web interface, the user needs to know uniform resource locator (URL) of the service. Moreover, in case of the backend application login, a client of backend application has to run on user system and the user needs to know the backend system. In addition, with both the web interface and backend application login, the user typically has to know the service to be used and also navigation path of the service.
SUMMARY OF THE INVENTION
[0005] What is described is a system and method for accessing a backend service. The method includes receiving a message at a client; parsing the message into parts of the message using a natural language processor; interpreting the parts of the message; identifying a service and a backend system based on the interpreted parts of the message; and invoking the service from the backend system.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] Embodiments of the invention are illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings in which like reference numerals refer to similar elements.
[0007] FIG. 1 illustrates a messenger based method to access a service from a backend according to an embodiment of the invention.
[0008] FIG. 2 a illustrates first part of a messenger based method to access a service from a backend according to another embodiment of the invention.
[0009] FIG. 2 b illustrates second part of a messenger based method to access a service from a backend according to another embodiment of the invention.
[0010] FIG. 3 illustrates functional architecture of a messenger based system to access a service from a backend according to an embodiment of the invention.
[0011] FIG. 4 illustrates architecture of a messenger based system to access a service from a backend according to an embodiment of the invention.
[0012] FIG. 5 illustrates architecture of a message processing engine according to an embodiment of the invention.
[0013] FIG. 6 illustrates architecture of a service client according to an embodiment of the invention.
DETAILED DESCRIPTION
[0014] FIG. 1 , FIG. 2 a and FIG. 2 b illustrate different embodiments of a messenger based method for accessing a service from a backend system. Referring initially to FIG. 1 , at 105 , a message is received at a client. At 110 , the message is parsed into parts of the message using a natural language processor and at 115 , the parts of the message are interpreted. Based on the interpreted parts of the message, at 120 , a service and a backend system is identified. At 125 , the service is then invoked from the backend system.
[0015] The message includes a text, graphical and voice format messages. The message also includes other formats, which may be parsed into parts of the message. The natural language processor (NLP) may include a grammatical rule based NLP, and a statistical NLP. The NLP includes processing features such as summarization, language reading, language writing, information extraction, information retrieval, machine translation, natural language generation, optical character recognition, question answering, text simplification, text to speech conversion, text proofing, speech segmentation, text segmentation, word sense disambiguation, syntactic disambiguation, and imperfect input recognition.
[0016] The parsing divides the message into different parts. For example, for a text message, the parts will include words of the text message. The interpretation of the parts creates a dependency among parts of the message. Parts of the message, when received, have little dependencies with other parts. For example, part of the message that is an adjective has little meaning without an attachment to another part, which is an appropriate head noun. Based on relation between parts, during interpretation, each part of the message associates itself to a corresponding other part of the message. For example, in a text message, the association is based on words in a language, which are commonly used and comparing such words with parts of the text message. The interpretation allows communication of identity, which defines section of speech such as noun, adjective, verb, of the parts to other parts within the message. The relation of a part with other parts within the context of the message is estimated. A database maintains a large sample of parameters for possible service and backend system is maintained. In one of the embodiments, the database includes business specific dictionaries such as a dictionary for enterprise resource planning and a separate dictionary for customer relationship management. Based on the estimation and information in the parts, the identification is made by comparing the parts of the message with the parameter of services and backend system stored in the database. If a match is found, the matched service and matched backend system are the identified service and the backend system.
[0017] The backend system typically stores and processes data. For example, the R/3 system from SAP AG is a backend system that is capable of handling many different types of data processing and management service in an enterprise resource planning (ERP) environment, such as services related to customer relationship management (CRM). Similarly, SAP AG provides a business warehouse (BW) system that offers data repository management services that can be used in connection with the backend system. For example, the BW system lets users formulate queries that can be run on various data repositories of backend data. The BW server also provides visual displays for presenting query results in formats that are most suitable for the various users of the system. Furthermore, services may include web services and the backend system may include web based backend systems as well. In another embodiment, this method is applicable for remote function (RFC) calls as well. RFCs are application program interfaces to R/3 systems of SAP AG. R/3 is a set of integrated business applications from SAP AG. R/3 uses the client/server model and provides the ability to store, retrieve, analyze, and process corporate data for financial analysis, production operation, human resource management, and other business processes. This method may be used to access any R/3 system, which is exposed to a non-R/3 system.
[0018] FIG. 2 a illustrates additional details of first part of the method according to another embodiment of the invention. At 202 , a messenger sends a message to a messenger server. The messenger may include an instant messenger for real time communication. The messenger may also include electronic mail messenger for non real time communication. The messenger runs on a computing device having a particular processing and memory capabilities such as a mobile phone, a laptop, and a personal computer. The messenger server includes a centralized location for the exchange of information for routing the message. The messenger server and the client may be on different physical boxes or may be logically different but in the same box. The messenger server handles different type of messages from different computing devices such as short text, voice messages, and graphical messages from a mobile phone, personal digital assistant, laptop, personal computer and from other such systems.
[0019] At 204 , a determination is made if the message is first message of the messenger. If so, then at 206 , a client is initiated in a message processing engine. The client is an instance of the messenger in the message processing engine. At 208 , a messenger server receives the message and checks the client for the message. At 210 , the messenger server routes the message to the client. At 212 , the message is then received at the identified client of the message processing engine. At 214 , the message is parsed into parts of the message. At 216 , the parts of the message are analyzed by comparing the parts of the message with a large sample of parameters for possible service and backend system, as contained in the database, which includes business specific dictionaries such as a dictionary for enterprise resource planning and a separate dictionary for customer relationship management. The parameter includes condition and field for which information has to be provided for identification of the service and the backend system. At 218 , a determination is made if information in the part of the message is sufficient to identify a service and a backend system. If so, then at 220 the parts are interpreted and at 222 , a service and a backend system are identified. At 224 , a model based on the information, identified service and identified backend system is created. At 226 , the information is passed from the model to the service in the backend system.
[0020] FIG. 2 b illustrates additional details of second part of the method according to another embodiment of the invention. If at 218 (Refer FIG. 2 a ), the information is not sufficient to identify the service and the backend system, then at 228 , a parameter is found for additional information. If this parameter is not directly detectable then a message processing engine enters into a more conversation mode where it will pose more generic words that may be related to the topic under discussion and then provokes the messenger to provide inputs that may be present in the dictionary. This is the conversation mode. This is done by finding the parameter for which the information is not provided in the message. The additional information may be used with the information to identify the service and the backend system. At 230 , the parameter is converted into a messenger understandable request, which is then transmitted to the messenger at 232 . The natural language processor converts the parameter into the messenger understandable request by associating the parameter with relevant section of speech such as noun, adjective, verb, and in relevant format such as text, graphical and voice. Once the service has been identified then there may be need to get direct values for the parameters required by the service and then the message processing engine will pose questions to get the values for the parameters. This is the data collection mode. Based on the request, the messenger sends an additional message having the additional information. At 234 , the additional message is received at the client. At 236 , the additional message is parsed into additional parts of the additional message, wherein the additional parts represent the additional information. At 238 , the additional parts are interpreted and based on the interpreted parts of the message and the interpreted additional parts of the additional message, at 240 , the service and the backend system are identified. At 242 , a model based on the information, additional information, identified service and identified backend system is created. At 244 , the information and the additional information are passed from the model to service in the backend system.
[0021] In another embodiment of the invention, if the information and the additional information are not sufficient to identify the service and the backend system, then a further parameter is found for further information to enable identification of the service and the backend system. If this parameter is not directly detectable then the system enters into the conversation mode where the message processing engine will pose more generic words that may be related to the topic under discussion and then provokes the user to provide inputs that may be present in the dictionary. This is the conversation mode. As explained earlier, this further parameter is converted into a further messenger understandable request. A further message with the further information is received at the client and parsed into further parts of the further message. The further parts are then interpreted. The interpreted parts, interpreted additional parts and interpreted further parts are used to identify the service and the backend system.
[0022] In above mentioned embodiment of the invention, the information is passed to the identified service in the identified backend system and the information updates the information in the service for a user.
[0023] In another embodiment of the invention, based on the information passed from the model to the backend system, the identified service is launched.
[0024] FIG. 3 illustrates a functional architecture of a messenger based system for accessing a backend service according to an embodiment of the invention. A messenger 305 sends a message to a message processing engine 310 . The message processing engine includes a client gateway 315 , which is connected to a tracking and logging unit 335 . The tracking and logging unit 335 determines if the message is first message from the messenger 305 . If so, the client gateway 315 initiates a client in the message processing engine 315 . In addition, tracking and logging unit 335 also tracks status of connectivity, activity of the messenger and communication of the messenger 305 with the message processing engine 310 . The message received at the client gateway 315 is sent to a language processing unit 320 . The language processing unit 320 parses the message into parts of the message. The parts are then interpreted by the language processing unit. The interpreted parts are then used to identify a service and a backend system. The client gateway sends the identified service and the backend system to a service invoking and proxy unit 325 , which creates a model based on information contained in the message, the identified service and backend system. The service invoking and proxy sets a connection with the identified backend system 340 and passes on the information from the model to the identified service (say to Service 2 345 ) in the identified backend system.
[0025] FIG. 4 illustrates architecture of a messenger based system to access a backend service according to an embodiment of the invention. A listener 415 creates an instance of the messager 405 as a client 425 in a message processing engine 420 . The messenger 405 sends a message to a messenger server 410 . The listener 415 determines if the message is first message from the messenger. If so, a client master 430 in a message processing engine 310 initiates the client 425 . The message is checked for a destination in the messenger and is routed to the client 425 . The client receives the message and sends the message to a natural language processor 440 . The natural language processor parses the message into parts of the message. The parts of the message are interpreted and the interpreted parts are sent to the client master via the client. The client master analyzes if the information in the interpreted parts of the message is sufficient to identify a service and a backend system. If so, then, the identified service 445 is invoked from the identified backend system 450 using a service client 435 . The invoking of the service includes the service client creating a model based on the information contained in the parts, the identified service and the backend system. Thereafter, the information is passed from the model to the identified service 445 in the identified backend system 450 .
[0026] In another embodiment of the invention, if the client master 430 analyzes that the information in the interpreted parts is not sufficient to identify a service, the client master 430 finds a parameter for additional information. If the client master cannot find the right parameter, the client master will propose a generic group of words which are syntactically related to the topic and prompts the user to provide an additional information. The additional information may be used with the information to identify a service and a backend system. The client master 430 converts the parameter into a messenger understandable request, which is then transmitted to the messenger 405 using a transmitter. If the parameter is not directly detectable then the client master 430 enters into a conversation mode where the message processing engine poses more generic words that may be related to the topic under discussion and then provokes the user to provide inputs that may be present in the dictionary. This is the conversation mode.
[0027] Based on the request, the messenger receives the messenger understandable request and provides additional information as an additional message. The additional message is received at the client 425 and is sent to the natural language processor 440 . The natural language processor 440 parses the additional messages into additional parts of the additional message. The natural language processor 440 further interprets the additional parts and sends the interpreted additional parts to the client master 430 via the client 425 . Based on the interpreted parts of the message and the interpreted additional parts of the additional message, the client master 430 identifies a service and a backend system. The identified service, backend system along with the information and the additional information is sent to the service client 450 . Based on the identified service, backend system, information and the additional information, the service client 435 creates a model. The service client 430 then passes the information and the additional information from the model to the identified service 435 in the identified backend system 450 .
[0028] FIG. 5 illustrates architecture of a message processing engine according to an embodiment of the invention. The message processing engine 505 includes components such as natural language processor 440 , client 425 and client master 430 (refer FIG. 4 ). In another embodiment, the message processing engine may include the service client also. The natural language processor, client and client master include sub-components. The sub-component includes a receiver 510 to receive a message, a parser 555 to parse the message into parts of the message, an interpreter 515 to interpret the parts of the message. The sub-components also include an analyzer 525 to analyze if the information in the message is sufficient to identify the service and the backend system. If the information is sufficient to identify the service and the backend system, then an identifier 520 identifies the service and the backend system based on the interpreted parts of the message.
[0029] However, if the information is not sufficient, a finder 530 finds a parameter for additional information. The additional information may be used with the information to identify a service and a backend system. A converter 535 converts the parameter into a messenger understandable request, which is then transmitted to the messenger using a transmitter 540 . If the parameter is not directly detectable then the client master 430 enters into a conversation mode where the message processing engine poses more generic words that may be related to the topic under discussion and then provokes the user to provide inputs that may be present in the dictionary. This is the conversation mode. An additional message is received from the messenger at the receiver 510 . The parser 555 parses the additional message having the additional message into parts of the additional message. The interpreter 515 interprets the parts of the additional message. Thereafter, based on the additional information and information, the identifier 520 identifies the service and backend system. Those skilled in the art will recognize that many other embodiments with respect to structure of the message processing engine is possible such as including a few functionalities of the client master in the natural language processor and fully within the scope and spirit of this disclosure. Different sub-components may be connected and communicates through communication channels 560 and 565 respectively.
[0030] FIG. 6 illustrates architecture of a service client according to an embodiment of the invention. The service client 630 includes a modeler 605 and a transmitter 625 . The modeler includes a user interface (UI) layer 610 , a business object layer 615 and a data access layer 620 . In general, the layers provide for separation and modularization of functionalities and services. These services are integrated into a single service via common interfaces that allow data to be exchanged between any two layers. For example, the business object layer 615 , which is used in part to define a model containing the information with functionality, structure and logic of a service, exists independently from UI layer 605 , which provides functionality for displaying a user interface. Since different computing devices have varying degrees of capabilities with respect to the various functionalities associated with the layers, the service client 630 allows for flexible adaptation of the service to accommodate the capabilities of various devices.
[0031] The UI layer 610 provides functionality for presenting a computing device with a graphical user interface. For example, according to one embodiment, user interface layer may include a plurality of hypertext markup language (HTML) or extensible markup language (XML) pages, which are fetched via a browser resident on the user computing device and presented to the user. The UI layer 610 may include an interaction layer, which provides functionality for responding to interactions between the client master ( 425 , Refer FIG. 4 ) and the UI layer 610 .
[0032] Business object layer 615 includes functionality for the core business logic underlying the service to be invoked. According to one embodiment of the present invention, a model is created through the information as provided by the client master ( 425 , Refer FIG. 4 ). The model provides abstraction of an underlying backend database 340 and thereby facilitates invoking of the service to include common notions of business entities. Among other functions, business object layer 615 may perform validations of data entered using the messenger ( 305 , Refer FIG. 4 ). Additionally, a processing layer may exist between the business object layer and the UI layer. The natural language processor, the client master the interpreter reside in the processing layer.
[0033] Data access layer 620 provides functionality via a transmitter 625 for interactions with backend system 635 . The data access layer 615 provides an interface to relate particular model containing information with corresponding web service managed fields in the backend system 340 . The information contained in the model created by the BO layer 615 is transmitted suing the functionalities of data access layer 620 and the transmitter 625 .
[0034] Other embodiments of the invention may be implemented in digital electronic circuitry, or in computer hardware, firmware, software, or in combinations of them.
[0035] Elements of the invention may also be provided as a machine-readable medium for storing the machine-executable instructions. The machine-readable medium may include, but is not limited to, Flash memory, optical disks, CD-ROMs, DVD ROMs, RAMs, EPROMs, EEPROMs, magnetic or optical cards, propagation media or other type of machine-readable media suitable for storing electronic instructions.
[0036] Throughout the foregoing description, for the purposes of explanation, numerous specific details were set forth in order to provide a thorough understanding of the invention. It will be apparent, however, to one skilled in the art that the invention may be practiced without some of these specific details. The underlying principles of the invention may be employed using a virtually unlimited number of different types of input data and associated actions.
[0037] Accordingly, the scope and spirit of the invention should be judged in terms of the claims which follow. | What is described is a system and method for accessing a backend service. The method includes receiving a message at a client; parsing the message into parts of the message using a natural language processor; interpreting the parts of the message; identifying a service and a backend system based on the interpreted parts of the message; and invoking the service from the backend system. | 6 |
CROSS REFERENCE TO PRIOR APPLICATIONS
This application is a U.S. National Phase application under 35 U.S.C. §371 of International Application No. PCT/EP2011/065044, filed on Aug. 31, 2011 and which claims benefit to German Patent Application No. 10 2010 048 709.0, filed on Oct. 19, 2010. The International Application was published in German on Apr. 26, 2012 as WO 2012/052216 A1 under PCT Article 21(2).
FIELD
The present invention relates to a mechanically controllable valve operating mechanism having a gas exchange valve on which a transmission arrangement acts by means of an end surface, wherein the transmission arrangement is mounted movably in the cylinder head by means of bearing means, and wherein the transmission arrangement is operatively connected to a valve-lift adjusting means and a camshaft, wherein the valve-lift adjusting means has a rotatable adjusting element with an eccentric element which has two base points and a peak contour and which acts on the transmission arrangement counter to a pre-stressing force of a spring element in such a way that different valve-lift positions can be set. The present invention further relates to a mechanically controllable valve operating mechanism arrangement having a plurality of gas exchange valves arranged in line to which at least two in-line cylinders are assigned and a transmission arrangement is assigned to one gas exchange valve, wherein each transmission arrangement is mounted movably in the cylinder head by means of bearing means, and wherein each transmission arrangement is operatively connected to a respective valve-lift adjusting means and a camshaft, wherein each valve-lift adjusting means has a rotatable adjusting element with an eccentric element which has two base points and a peak contour and which acts on the transmission arrangement counter to a pre-stressing force of a spring element in such a way that different valve-lift positions can be set, such as zero lift, partial lift and full lift, wherein a plurality of adjusting elements can be driven by one driving element.
BACKGROUND
EP 638 706 A1 describes a valve operating mechanism and a valve operating mechanism arrangement where the valve lift is controlled or regulated by an eccentric shaft rotatably supported in a cylinder head, which shaft acts on the transmission arrangement such that valve lifts between zero and maximum can be set in a simple manner. The combustion process can thereby be adjusted to the respective operating state of the internal combustion machine. DE 10 2004 003 327 A1 describes providing adjusting elements in a valve operating mechanism arrangement which can be adjusted independently with the purpose of deactivating individual cylinders for certain operating states. A valve operating mechanism is also described in EP 1 760 278 A2 which comprises an eccentric element showing different curves, in particular, for partial lift and full lift. The adjusting element here also allows for a zero lift curve.
The above-described valve operating mechanisms/valve operating mechanism arrangements all have the disadvantage that an adjustment of the valve lift by means of the eccentric element curve must be performed very precisely. The variability of the valve lift settings is also very limited in a state of partial deactivation of cylinders, which in turn leads to increased fuel consumption and thus to higher emission values.
SUMMARY
An aspect of the present invention is to provide a valve operating mechanism or a valve operating mechanism arrangement that avoids the above-described disadvantages.
In an embodiment, the present invention provides a mechanically controllable valve operating mechanism which includes a cylinder head, a bearing device, a spring element, a camshaft, a transmission arrangement comprising an end surface. The transmission arrangement is mounted so as to be movable in the cylinder head via the bearing device. A gas exchange valve is configured to have the transmission arrangement act thereon via the end surface of the transmission arrangement. A valve-lift adjusting device comprises a rotatable adjusting element with an eccentric element having two base points and a peak contour, and at least one further eccentric element arranged in a circumferential direction. The valve-lift adjusting device is configured to act on the transmission arrangement counter to a pre-stressing force of the spring element so that different valve-lift positions are settable. The transmission arrangement is operatively connected to the valve-lift adjusting device and to the camshaft. The at least one further eccentric element of the rotating adjusting element is arranged so that at least two peak contours are provided so that, depending on a rotational angle α of the rotating adjusting element, the eccentric element or the at least one further eccentric element engage with the transmission arrangement. In this way, it is possible, firstly, to switch between at least three valve lift states in a simple and quick manner, it being irrelevant in which direction the adjusting element is turned. A low-cost solution is further provided that allows for a reduction of fuel consumption and emission values of an internal combustion engine by increasing the variability of a gas exchange valve.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is described in greater detail below on the basis of embodiments and of the drawings in which:
FIG. 1 shows a perspective illustration of a valve operating mechanism arrangement of the present invention;
FIG. 2 shows a sectional view of an eccentric shaft with two adjusting elements; and
FIG. 3 shows a schematic illustration of the opening characteristic of the inlet valves with respect to the position of the adjusting elements.
DETAILED DESCRIPTION
In an embodiment of the present invention, the base points of the respective eccentric elements can, for example, be spaced from each other by at least a zero lift curve. A plurality of zero lift curve shapes are thus created on the circumference of the adjusting element, thereby allowing a much more variable purposeful deactivation of cylinders. It can moreover be advantageous if the eccentric elements have different shapes and thus have respective valve lift curve sets that are different in form. It is also possible that at least one eccentric element is formed asymmetrically with respect to the respective peak point. In an embodiment of the present invention, the transmission arrangement includes at least one pivot lever and at least one rocker lever, wherein the pivot lever engages the gas exchange valve with a work curve and the rocker lever is operatively connected with the valve lift adjusting means and the camshaft and engages the pivot lever with a work curve.
In an embodiment of the present invention, at least one adjusting element comprises at least one further eccentric element along its circumferential direction to provide at least two peak contours so that, depending on the rotation angle α of the adjusting element, different eccentric elements can pass into engagement with the transmission arrangement. Such an arrangement provides an economic and simple to manufacture possibility to deactivate individual valves, and thus cylinders, of an internal combustion machine in certain operating states. If the valve operating mechanism arrangement is configured such that the base points of the respective eccentric elements of the at least one adjusting element are spaced from each other by at least one zero lift curve, it is possible to realize the engine deactivation in a very variable manner. A large set of valve lift curves for the various load states is nevertheless still available to the cylinders operated. This variability is even increased if the eccentric elements have different shapes and/or at least one eccentric element is formed asymmetrically with respect to the respective peak point. In an embodiment of the present invention, a plurality of adjusting elements can be adapted to be driven by one driving element.
In an embodiment of the present invention, a plurality of eccentric elements can be provided on one eccentric shaft.
In an embodiment of the present invention, each transmission arrangement has at least one pivot lever and at least one rocker lever, where the pivot lever engages the gas exchanging valve by means of an end face and the rocker lever is operatively connected with the valve lift adjusting means and a camshaft and engages the pivot lever by means of a work curve. For an optimal combustion, it is advantageous if an even number of cylinders is provided, one half of the cylinders comprising gas exchange valves which each have one eccentric element more assigned thereto than the other half of the gas exchanging valves. On the outlet side, one half of the cylinders may further have gas exchanging valves that are operatively connected with a valve lift adjusting means, while the other half of the cylinders are adapted for conventional operation.
The present invention will be described hereinafter with respect to the drawings.
FIG. 1 illustrates an embodiment of a valve operating mechanism arrangement 10 of the present invention comprising a plurality of in-line gas exchange valves 12 , 14 , 16 , 18 , 20 , 22 , 24 and 26 . In the present case, two inlet gas exchange valves are respectively assigned to one cylinder of the internal combustion machine. In the present instance, the mechanically controllable valve operating mechanism arrangement 10 comprises four transmission arrangements 28 , 29 , 30 , 31 , 32 , 33 and 34 , 35 , each of which has assigned thereto two gas exchange valves 12 , 14 ; 16 , 18 ; 20 , 22 ; 24 , 26 . The transmission arrangements 28 , 29 , 30 , 31 , 32 , 33 and 34 , 35 are supported in a manner known per se in the cylinder head using bearing means. In FIG. 1 , the bearing means 36 , 38 are illustrated merely as examples for the bearing of a pivot lever 56 of the transmission arrangement 35 . The transmission arrangements 28 , 29 , 30 , 31 , 32 , 33 and 34 , 35 are further operatively connected with a camshaft 40 in a manner known per se. Each transmission arrangement 28 , 29 , 30 , 31 , 32 , 33 and 34 , 35 is controllable by means of adjusting elements 42 , 43 , 44 , 45 , 46 , 47 and 48 , 49 of a valve lift adjusting means 41 such that a smaller or a larger valve lift of the inlet valves 12 , 14 ; 16 , 18 ; 20 , 22 ; 24 , 26 can be set. In the present embodiment, the adjusting elements 42 , 43 , 44 , 45 , 46 , 47 and 48 , 49 are assigned to two inlet valves 12 , 14 ; 16 , 18 ; 20 , 22 ; 24 , 26 , respectively, and are designed as eccentric elements 60 , 62 provided on an eccentric shaft 50 . In the present embodiment, the eccentric shaft 50 is adapted to be driven in a manner known per se by means of a driving element 52 . It is also possible to assign a transmission arrangement to each of the plurality of gas exchange valves. The driving element 52 may be a rotary drive running both clockwise and counterclockwise. The eccentric shaft 50 can thereby be driven such that, depending on the given position, the valve lift corresponding to the next operating state can be selected in a quick and precise manner by implementing the corresponding eccentric elements 60 , 62 . Even rotation angles >360° can thereby be realized.
In the present embodiment, a mechanically controllable valve operating mechanism 54 comprises the transmission arrangement 35 and the gas exchange valve 26 . In this case, the transmission arrangement 35 is formed by a pivot lever 56 and a rocker lever 58 , the pivot lever 56 engaging the gas exchange valve 26 by means of an end face and the rocker lever 58 being operatively connected with the valve lift adjusting means 41 and the camshaft 40 . The adjusting element 48 of the valve lift adjusting means 41 here engages an engagement element, not illustrated in detail (a roller, for instance), of the rocker lever 58 against a pre-stressing force of a spring 55 . The rocker lever 58 engages the pivot lever 56 by means of a work curve not illustrated in detail. Guide rollers are arranged on the opposite side, which guide the rocker lever 58 in a slotted link. The guide rollers themselves are supported on a shaft that connects two adjacent rocker levers, with a roller being arranged on the shaft between the guide rollers, which is operatively connected with the camshaft. One cam of the camshaft is thus operatively connected with two transmission arrangements. With respect to the function and the operation of such a transmission arrangement, reference is made to DE 10 1140 635 A1.
The present invention provides that individual adjusting elements, in the present embodiment the adjusting elements 42 , 43 and 48 , 49 , comprise a further eccentric element (see FIG. 2 ). FIG. 2 illustrates two sections through the eccentric shaft 50 ; one through the adjusting element 42 and the other through the adjusting element 47 . In the present embodiment, the adjusting element 42 for the gas exchange valve 12 thus comprises two eccentric elements 60 , 62 which can influence the lift height of the gas exchange valve 12 . The eccentric elements 60 , 62 each have a peak contour 61 , 63 , where the peak contour 63 is in the form of a single peak. In the present context, a peak contour is defined as a finite sequence of peaks, i.e., also a single one. The peak contour triggers the respective full lift height of the gas exchange valve which is operatively connected with the respective eccentric element of an adjusting element via the transmission arrangement. The eccentric elements 60 , 62 are shaped differently with respect to their height and the curve shape, the eccentric element 62 being symmetric with respect to its peak point 63 , while the eccentric element 60 is asymmetric, thereby leading to a flatter rise of the associated valve lift curve set. The associated peak point 63 or the peak contour 61 trigger the different full lift heights of the respective eccentric elements 60 , 62 .
In this embodiment, two base points 64 and 70 are further provided, where a base point is the point at which a zero lift curve passes into a partial lift curve. In the present embodiment, a zero lift curve 72 is thus formed between the respective base points 64 and 70 . Idling points 66 and 68 are further provided, at which an idling lift curve passes into a partial lift curve. The region between the idling points 66 and 68 is accordingly referred to as the idling lift curve 74 which is raised on the eccentric shaft by about 0.2 mm with respect to the zero lift curve. The idling lift curve 74 has the advantage that during control by means of this region or when passing through this region, the cylinder is not completely deactivated and therefore does not cool down. The second adjusting element 47 has only one eccentric element 76 which is formed congruently in shape and height with the eccentric element 62 . A zero lift curve 78 and an idling lift curve 80 are further provided that merge in the region of the peak contour 61 of the adjusting element 42 and which are defined by base points 82 , 84 and an idling point 85 .
It should be clear that all conceivable shapes that seem reasonable can be used for the eccentric elements. It is also possible that one adjusting element comprises more than two eccentric elements. In the present embodiment, the adjusting elements 44 and 46 for the valve lift adjustment of the gas exchange valves 16 , 18 , 20 and 22 comprise only one eccentric element 62 and thus correspond to the adjusting element known from the prior art.
FIG. 3 schematically illustrates the different valve lift settings according to the present embodiment. The illustration shows four cylinders 86 , 88 , 90 , 92 that comprise the inlet valves 12 , 14 , 16 , 18 , 20 , 22 , 24 and 26 shown in from FIG. 1 . The adjusting elements 42 and 48 associated to the gas exchange valves 12 , 14 , and 24 , 26 here each have only one eccentric element 60 . If the eccentric shaft 50 is adjusted such that the eccentric elements 62 engage the respective rocker levers 58 , the valve lifts shown under I in FIG. 3 can be set for the inlet valves 12 , 14 and 24 , 26 . The inlet valves 16 , 18 and 20 , 22 are deactivated. In order to make all inlet valves 12 , 14 , 16 , 18 , 20 , 22 , 24 and 26 open during the operation of the internal combustion machine, the eccentric shaft 50 is rotated such about an angle α that the eccentric elements 62 pass into engagement with the respective rocker levers 58 . The valve lifts schematically illustrated under II can thus be realized for the inlet valves 12 , 14 , 16 , 18 , 20 , 22 , 24 and 26 . The sense of rotation of the adjusting elements can thus be chosen such that the desired valve lift curve set can be controlled quickly and precisely.
For a simple deactivation of cylinders, however, it is particularly advantageous with an even number of cylinders to assign adjusting elements to one half of the cylinders, which elements each have one eccentric element more than the other half of the cylinders. Of course, it is also possible to control the outlet valve by means of such an arrangement, in order to provide a corresponding deactivation of the outlet valves when the inlet valves are deactivated.
The present invention is not limited to embodiments described herein; reference should be had to the appended claims. | A mechanically controllable valve operating mechanism includes a cylinder head, a camshaft, a transmission arrangement mounted to move in the cylinder head via a bearing device. A gas exchange valve has the transmission arrangement act thereon. A valve-lift adjusting device comprises a rotatable adjusting element with an eccentric element having two base points and a peak contour, and at least one further eccentric element. The valve-lift adjusting device acts on the transmission arrangement so that different valve-lift positions are settable. The transmission arrangement is connected to the valve-lift adjusting device and to the camshaft. The at least one further eccentric element of the rotating adjusting element is arranged so that at least two peak contours are provided so that, depending on a rotational angle α of the rotating adjusting element, the eccentric element or the at least one further eccentric element engage with the transmission arrangement. | 5 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to real-time computer thermal management and power conservation, and more particularly to an apparatus and method for decreasing and increasing central processing unit (CPU) clock time based on temperature and real-time activity levels within the CPU of a portable computer.
[0003] 2. Description of the Related Art
[0004] During the development stages of personal computers, the transportable or portable computer has become very popular. Such portable computer uses a large power supply and really represents a small desktop personal computer. Portable computers are smaller and lighter than a desktop personal computer and allow a user to employ the same software that can be used on a desktop computer.
[0005] The first generation “portable” computers only operated from an A/C wall power. As personal computer development continued, battery-powered computers were designed. Furthermore, real portability became possible with the development of new display technology, better disk storage, and lighter components. Unfortunately, the software developed was designed to run on desk top computers without regard to battery-powered portable computers that only had limited amounts of power available for short periods of time. No special considerations were made by the software, operating system (MS-DOS), Basic Input/Output System (BIOS), or the third party application software to conserve power usage for these portable computers.
[0006] As more and more highly functional software packages were developed, desktop computer users experienced increased performance from the introductions of higher computational CPUs, increased memory, and faster high performance disk drives. Unfortunately, portable computers continued to run only on A/C power or with large and heavy batteries. In trying to keep up with the performance requirements of the desk top computers, and the new software, expensive components were used to cut the power requirements. Even so, the heavy batteries still did not run very long. This meant users of portable computers has to settle for A/C operation or very short battery operation to have the performance that was expected from the third party software.
[0007] Portable computer designers stepped the performance down to 8088- and 8086-type processors to reduce the power consumption. The supporting circuits and CPU took less power to run and therefore, lighter batteries could be used. Unfortunately, the new software requiring 80286-type instructions, that did not exist in the older slower 8088/8086 CPUs, did not run. In an attempt to design a portable computer that could conserve power, thereby yielding longer battery operation, smaller units, and less weight, some portable computer designers proceeded to reduce power consumption of a portable computer while a user is not using the computer. For example, designers obtain a reduction in power usage by slowing or stopping the disk drive after some predetermined period of inactivity; if the disk drive is not being used, the disk drive is turned off, or simply placed into a standby mode. When the user is ready to use the disk, the operator must wait until the disk drive spins up and the computer system is ready again for full performance before the operator may proceed with the operation.
[0008] Other portable computer designers conserve power by turning the computer display off when the keyboard is not being used. However, in normal operation the computer is using full power. In other words, power conservation by this method is practical only when the user is not using the components of the system. It is very likely, however, that the user will turn the computer off when not in use. Nevertheless, substantial power conservation while the operator is using the computer for meaningful work is needed. When the operator uses the computer, full operation of all components is required. During the intervals while the operator is not using the computer, however, the computer could be turned off or slowed down to conserve power consumption. It is critical to maintaining performance to determine when to slow the computer down or turn it off without disrupting the user's work, upsetting the third party software, or confusing the operating system, until operation is needed.
[0009] Furthermore, although a user can wait for the disk to spin up as described above, application software packages cannot wait for the CPU to “spin up” and get ready. The CPU must be ready when the application program needs to compute. Switching to full operation must be completed quickly and without the application program being affected. This immediate transition must be transparent to the user as well as to the application currently active. Delays cause user operational problems in response time and software compatibility, as well as general failure by the computer to accurately execute a required program.
[0010] Other attempts at power conservation for portable computers include providing a “Shut Down” or “Standby Mode” of operation. The problem, again, is that the computer is not usable by the operator during this period. The operator could just as well turned off the power switch of the unit to save power. This type of power conservation only allows the portable computer to “shut down” and thereby save power if the operator forgets to turn off the power switch, or walks away from the computer for the programmed length of time. The advantage of this type of power conservation over just turning the power switch off/on is a much quicker return to full operation. However, this method of power conservation is still not real-time, intelligent power conservation while the computer is on and processing data which does not disturb the operating system, BIOS, and any third party application programs currently running on the computer.
[0011] Some attempt to meet this need was made by VLSI vendors in providing circuits that either turned off the clocks to the CPU when the user was not typing on the keyboard or woke up the computer on demand when a keystroke occurred Either of these approaches reduce power but the computer is dead (unusable) during this period. Background operations such as updating the system clock, communications, print spooling, and other like operations cannot be performed. Some existing portable computers employ these circuits. After a programmed period of no activity, the computer turns itself off. The operator must turn the machine on again but does not have to reboot the operating system and application program. The advantage of this circuitry is like the existing “shut down” operations, a quick return to full operation without restarting die computer. Nevertheless, this method only reduces power consumption when the user walks away from the machine and does not actually extend the operational like of the battery charge.
[0012] Thermal over-heating of CPUs and other related devices is another problem vet to be addressed by portable computer manufacturers. CPUs are designed to operate within specific temperature ranges (varies depending on CPU type, manufacturer, quality, etc). CPU performance and speed degenerates when the limits of the operation temperature ranges are exceeded, especially the upper temperature range. This problem is particularly acute with CPUs manufactured using CMOS technology where temperatures above the upper temperature range result in reduced CPU performance and speed. Existing power saving techniques save power but do not measure and intelligently control CPU and/or related device temperature.
SUMMARY OF THE INVENTION
[0013] In view of the above problems associated with the related art, it is an object of the present invention to provide an apparatus and method for real-time conservation of power and thermal management for computer systems without any real-time performance degradation, such conservation of power and thermal management remaining transparent to the user.
[0014] Another object of the present invention is to provide an apparatus and method for predicting CPU activity and temperature levels and using the predictions for automatic power conservation and temperature control.
[0015] Yet another object of the present invention is to provide an apparatus and method which allows user modification of automatic activity and temperature level predictions and using the modified predictions for automatic power conservation and temperature control.
[0016] A further object of the present invention is to provide an apparatus and method for real-time reduction and restoration of clock speeds thereby returning the CPU to full processing rate from a period of inactivity which is transparent to software programs.
[0017] These objects are accomplished in a preferred embodiment of the present invention by an apparatus and method which determine whether a CPU may rest (including any PCI bus coupled to the CPU) based upon CPU activity and temperature levels and activates a hardware selector based upon that determination. If the CPU may rest, or sleep, the hardware selector applies oscillations at a sleep clock level; if the CPU is to be active, the hardware selector applies oscillations at a high speed clock level.
[0018] The present invention examines the state of CPU activity and temperature, as well as the activity of both the operator and any application software currently active. This sampling of activity and temperature is performed real-time, adjusting the performance level of the computer to manage power conservation, CPU temperature and computer power. These adjustments are accomplished within the CPU cycles and do no affect the user's perception of performance.
[0019] Thus, when the operator for the third party software of the operating system/BIOS is not using the computer, the present invention will effect a quick turn off or slow down of the CPU until needed, thereby reducing the power consumption and CPU temperature, and will promptly restore full CPU operation when needed without affecting perceived performance. This switching back into full operation from the “slow down” mode occurs without the user having to request it and without any delay in the operation of the computer while waiting for the computer to return to a “ready” state.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself, however, as well as other features and advantages thereof, will be best understood by reference to the detailed description with follows, read in conjunction with the accompanying, drawings, wherein:
[0021] FIG. 1 is a flowchart depicting the self-tuning aspect of a preferred embodiment of the present invention.
[0022] FIGS. 2 a - 2 d are flowcharts depicting the active power conservation monitor employed by the present invention.
[0023] FIG. 3 is a simplified schematic diagram representing the active power conservation associated hardware employed by the present invention.
[0024] FIG. 4 is a schematic of the sleep hardware for one embodiment of the present invention.
[0025] FIG. 5 is a schematic of the sleep hardware for another embodiment of the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0026] If the period of computer activity in any given system is examined, the CPU and associated components have a utilization percentage. If the user is inputting data from the keyboard, the time between keystrokes is very long in terms of CPU cycles. Many things can be accomplished by the computer during this time, such as printing a report. Even during the printing of a report, time is still available for additional operations such as background updating of a clock/calendar display. Even so, there is almost always spare time when the CPU is not being used. If the computer is turned off or slowed down during this spare time, then power consumption is obtained real-time. Such real-time power conservation extends battery operation life and lowers CPU temperature.
[0027] According to one embodiment of the present invention, to conserve power and lower CPU temperature under MS-DOS, as well as other operating systems such as OS/2, XENIS, and those for Apple computers, requires a combination of hardware and software It should be noted that because the present invention will work in any system, while the implementation may vary slightly on a system-by-system basis, the scope of the present invention should therefore not be limited to computer systems operating under MS/DOS.
[0028] Slowing down or stopping computer system components reduces power consumption and lowers CPU temperature, although the amount of power saved and CPU temperature reduction may vary. Therefore, according to the present invention, stopping the clock (where possible as some CPUs cannot have their clocks stopped) reduces power consumption and CPU temperature more than just slowing the clock.
[0029] In general, the number of operations (or instructions) per second may be considered to be roughly proportional to the processor clock:
instructions/second=instructions/cycle*cycles/second
Assuming for simplicity that the same instruction is repeatedly executed so that instructions/second is constant, the relationship can be expressed as follows:
Fq=K 1 *Clk
where Fq is instructions/second, K 1 is constant equal to the instructions/cycle, and Clk equals cycles/second. Thus, roughly speaking, the rate of execution increases with the frequency of the CPU clock.
[0030] The amount of power being used at any given moment is also related to the frequency of the CPU clock and therefore to the rate of execution. In general this relationship can be expressed as follows:
P=K 2 +( K 3 *Clk )
where P is power in watts, K 2 is a constant in watts, K 3 is a constant and expresses the number of watt-second/cycle, and Clk equals the cycles/second of the CPU clock. Thus it can also be said that the amount of power being consumed at any given time increases as the CPU clock frequency increases.
[0031] Assume that a given time period T is divided into N intervals such that the power P is constant during each interval. Then the amount of energy E expended during T is given by:
E=P (1)delta T 1 +P (2)delta T 3 . . . P ( N )delta T N
Further assume that the CPU clock “CLK” has only two states, either “ON” or “OFF”. For the purposes of this discussion, the “ON” 0 state represents the CPU clock at its maximum frequency, while the “OFF” state represents the minimum clock rate at which the CPU can operate (this may be zero for CPUs that can have their clocks stopped). For the condition in which the CPU clock is always “ON”, each P(i) in the previous equation is equal and the total energy is:
E (max)= P (on)*(delta T 1 +delta T 2 . . . delta T N )= P (on)* T
[0032] This represents the maximum power consumption of the computer in which no power conservation measures are being used. If the CPU clock is “off” during a portion of the intervals, then there are two power levels possible for each interval. The P(on) represents the power being consumed when the clock is in its “ON” state, while P(off) represents the power being used when the clock is “OFF”. If all of the time intervals in which the clock is “ON” are [is] summed into the quantity “T(on)” and the “OFF” intervals are summed into “T(off)”, then it follows:
T=T (on)+ T (off)
Now the energy being used during period T can be written:
E=[P (on)* T (on)]+[ P (off)* T (off)]
Under these conditions, the total energy consumed may be reduced by increasing the time intervals T(off). Thus, by controlling the periods of time the clock is in its “OFF” state, the amount of energy being used may be reduced. If the T(off) period is divided into a large number of intervals during the period T, then as the width of each interval goes to zero, energy consumption is at a maximum. Conversely, as the width of the T(off) intervals increase, the energy consumed decreases.
[0033] If the “OFF” intervals are arranged to coincide with periods during which the CPU is normally inactive, then the user cannot perceive any reduction in performance and overall energy consumption is reduced from the E(max) state. In order to align the T(off) intervals with periods of CPU inactivity, the CPU activity and temperature levels are used to determine the width of the T(off) intervals in a closed loop. FIG. 1 depicts such a closed loop. The activity level of the CPU is determined at Step 10 . If this level is a decrease over an immediately previous determination (Step 22 ), the present invention increases the T(off) interval (Step 20 ) and returns to determine the activity level of the CPU again. If, on the other hand, this activity level is an increase over an immediately previous determination (Step 22 ), a determination is made as to whether or not the temperature of the CPU is a concern (Step 24 ). If CPU temperature is not a concern, the present invention decreases the T(off) interval (Step 30 ) and proceeds to again determine the activity level of the CPU. If, on the other hand, CPU temperature is a concern, a determination is made as to whether or not the CPU is processing critical I/O, a critical function or a critical real-time event (Step 26 ). If critical I/O or critical function or a critical real-time event are being processed, the present invention decreases the T(off) interval (Step 30 ) and proceeds to again determine the activity level of the CPU. If no critical I/O is being processed, the present invention increases the T(off) interval (Step 20 ) and proceeds again to determine the activity level of the CPU. Thus the T(off) intervals are constantly being adjusted to match the system activity level and control the temperature level of the CPU.
[0034] Management of CPU temperature (thermal management) is necessary because CPUs are designed to operate within a specific temperature range. CPU performance and speed deteriorates when the specified high operating temperature of a CPU is exceeded (especially in CMOS process CPUs where temperatures above the high operating temperature translate into slower CPU speed). The heat output of a CPU is directly related to the power consumed by the CPU and heat it absorbs from devices and circuitry that immediately surround it. CPU power consumption increases with CPU clock speed and the number of instructions per second to be performed by the CPU. As a result, heat related problems are becoming more common as faster and increasingly complex CPUs are introduced and incorporated into electronic devices.
[0035] In any operating system, two key logic points exist: an IDLE, or “do nothing”, loop within the operating system and an operating system request channel, usually available for services needed by the application software. By placing logic inline with these logic points, the type of activity request made by an application software can be evaluated, power conservation and thermal management can be activated and slice periods determined. A slice period is the number of T(on) vs. T(off) intervals over time, computed by the CPU activity and thermal levels. An assumption may be made to determine CPU activity level: Software programs that need service usually need additional services and the period of time between service requests can be used to determine the activity level of any application software running on the computer and to provide slice counts for power conservation according to the present invention. Another assumption that may be made is that each CPU has a temperature coefficient unique to that CPU—CPU temperature rise time, CPU maximum operating temperature, CPU temperature fall time and intervention time required for thermal control. If this information is not provided by the CPU manufacturer, testing of the CPU being used (or another of the same make and type tested under similar conditions) is required to obtain accurate information.
[0036] Once the CPU is interrupted during a power conservation and thermal management slice (T(off)), the CPU will save the interrupted routine's state prior to vectoring to the interrupt software. Off course, since the power conservation and thermal management software was operating during this slice, control will be returned to the active power conservation and thermal management loop (monitor 40 ) which simply monitors the CPU's clock to determine an exit condition for the power conservation and thermal management mode thereby exiting from T(off) to T(on) state. The interval of the next power conservation and thermal management state is adjusted by the activity level monitor, as discussed above in connection with FIG. 1 . Some implementations can create an automatic exit from T(off) by the hardware logic, thereby forcing the power conservation and thermal management loop to be exited automatically and executing an interval T(on).
[0037] More specifically, looking now at FIGS. 2 a - 2 d , which depict the active power conservation and thermal management monitor 40 of the present invention. The CPU installs monitor 40 either via a program stored in the CPU ROM or loads it from an external device storing the program in RAM. Once the CPU has loaded monitor 40 , it continues to INIT 50 for system interrupt initialization, user configurational setup, and system/application specific initialization. IDLE branch 60 (more specifically set out in FIG. 2 b ) is executed by a hardware or software interrupt for an IDLE or “do nothing” function. This type of interrupt is caused by the CPU entering either an IDLE or a “do nothing” function. This type of interrupt is caused by the CPU entering either an IDLE or a “do nothing” loop (i.e., planned inactivity). The ACTIVITY branch 70 of the flow chart, more fully described below in relation to FIG. 2 d , is executed by a software or hardware interrupt due to an operating system or I/O service request, by an application program or internal operating system function. An I/O service request made by a program may, for example, be a disk I/O, read, print, load, etc. Regardless of the branch selected, control is eventually returned to the CPU operating system at RETURN 80 . The INIT branch 50 of this flowchart, shown in FIG. 2 a , is executed only once if it is loaded via program into ROM or is executed every time during power up if it is loaded from an external device and stored in the RAM. Once this branch of active power and thermal management monitor 40 has been fully executed, whenever control is yielded from the operating system to the power conservation and thermal management mode, either IDLE 60 or ACTIVITY 70 branches are selected depending on the type of CPU activity: IDLE branch 60 for power conservation and thermal management during planned inactivity and ACTIVITY branch 70 for power conservation and thermal management during CPU activity.
[0038] Looking more closely at INIT branch 50 , after all system interrupt and variables are initialized, the routine continues at Step 90 to set the Power_level equal to DEFAULT_LEVEL. In operating systems where the user has input control for the Power_level, the program at Step 100 checks to see if a User_level has been selected. If the User_level is less than zero or greater than the MAXIMUM_LEVEL, the system used the DEFAULT_LEVEL. Otherwise, it continues onto Step 110 where it modifies the Power_level to equal the User_level.
[0039] According to the preferred embodiment of the present invention, the system at Step 120 sets the variable Idle_tick to zero and the variable Activity_tick to zero. Under an MS/DOS implementation. Idle_tick refers to the number of interrupts found in a “do nothing” loop. Activity_tick refers to the number of interrupts caused by an activity interrupt which in turn determines the CPU activity level. Tick count represents a delta time for the next interrupt. Idle_tick is a constant delta time from one tick to another (interrupt) unless overwritten by a software interrupt. A software interrupt may reprogram delta time between interrupts.
[0040] After setting the variables to zero, the routine continues on to Setup 130 at which time any application specific configuration fine-tuning is handled in terms of system-specific details and the system is initialized. Next the routine arms the interrupt I/O (Step 140 ) with instructions to the hardware indicating the hardware can take control at the next interrupt. INIT branch 50 then exits to the operating system, or whatever called the active power and thermal management monitor originally, at RETURN 80 .
[0041] Consider now IDLE branch 60 of active power and thermal management monitor 40 , more fully described at FIG. 2 b . In response to a planned inactivity of the CPU, monitor 40 (not specifically shown in this Figure) checks to see if entry into IDLE branch 60 is permitted by first determining whether the activity interrupt is currently busy. If Busy_A equals BUSY_FLAG (Step 150 ), which is a reentry flag, the CPU is busy and cannot now be put to sleep. Therefore, monitor 40 immediately proceeds to RETURN I 160 and exits the routine. RETURN I 160 is an indirect vector to the previous operating system IDLE vector interrupt for normal processing stored before entering monitor 40 . (I.e., this causes an interrupt return to the last chained vector.) If the Busy_A interrupt flag is not busy, then monitor 40 checks to see if the Busy Idle interrupt flag, Busy_I, equals BUSY_FLAG (Step 170 ). If so, this indicates the system is already in IDLE branch 60 of monitor 40 and therefore the system should not interrupt itself. If Busy_I=BUSY_FLAG, the system exits the routine at RETURN_I indirect vector 160 .
[0042] If, however, neither the Busy_A reentry flag or the Busy_I reentry flag have been set, the routine sets the Busy_I flag at Step 180 for reentry protection (Busy_I=BUSY_FLAG). At Step 190 Idle_tick is incremented by one. Idle_tick is the number of T(on) before a T(off) interval and is determined from IDLE interrupts, setup interrupts and from CPU activity and temperature levels. Idle_tick increments by one to allow for smoothing of events, thereby letting a critical I/O activity control smoothing.
[0043] At Step 200 monitor 40 checks to see if Idle_tick equals IDLE_MAXTICKS. IDLE_MAXTICKS is one of the constants initialized in Setup 130 of INIT branch 50 , remains constant for a system, and is responsible for self-tuning of the activity and thermal levels. If Idle_tick does not equal IDLE_MAXTICKS, the Busy_I flag is cleared at Step 210 and exits the loop proceeding to the RETUN I indirect vector 160 . If, however, Idle_tick equals IDLE_MAXTICKS, Idle_tick is set equal to IDLE_START_TICKS (Step 220 ). IDLE_START_TICKS is a constant which may or may not be zero (depending on whether the particular CPU can have its clock stopped). This step determines the self-tuning of how often the rest of the sleep functions may be performed. By setting IDLE_START_TICKS equal to IDLE_MAXTICKS minus one, a continuous T(off) interval is achieved. At Step 230 , the Power_level is checked. If it is equal to zero, the monitor clears the Busy_I flag (Step 210 ), exits the routine at RETURN I 160 , and returns control to the operating system so it may continue what it was originally doing before it entered active power monitor 40 .
[0044] If, however, the Power_level does not equal zero at Step 240 , the routine determines whether an interrupt mask is in place. An interrupt mask is set by the system/application software, and determines whether interrupts are available to monitor 40 . If interrupts are NOT_AVAILABLE, the Busy_I reentry flag is cleared and control is returned to the operating system to continue what it was doing before it entered monitor 40 . Operating systems, as well as application software, can set T(on) interval to yield a continuous T(on) state by setting the interrupt mask equal to NOT_AVAILABLE.
[0045] Assuming an interrupt is AVAILABLE, monitor 40 proceeds to the SAVE POWER subroutine 250 which is fully executed during one T(off) period established by the hardware state. (For example, in the preferred embodiment of the present invention, the longest possible interval could be 18 ms, which is the longest time between two ticks or interrupts from the real-time clock.) During the SAVE POWER subroutine 250 , the CPU clock is stepped down to a sleep clock level.
[0046] Once a critical I/O operation forces the T(on) intervals, the IDLE branch 60 interrupt tends to remain ready for additional critical I/O requests. As the CPU becomes busy with critical I/O, less T(off) intervals are available. Conversely, as critical I/O requests decrease, and the time intervals between them increase, more T(off) intervals are available. IDLE branch 60 is a self-tuning system based on feedback from CPU activity and temperature interrupts and tends to provide more T(off) intervals as the activity level slows and/or the CPU temperature becomes a concern. As soon as monitor 40 has completed SAVE POWER subroutine 250 , shown in FIG. 2 c and more fully described below, the Busy_I reentry flag is cleared (Step 210 ) and control is returned at RETURN I 160 to whatever operating system originally requested monitor 40 .
[0047] Consider now FIG. 2 c , which is a flowchart depicting the SAVE POWER subroutine 250 . Monitor 40 determines what the I/O hardware high speed clock is at Step 260 . It sets the CURRENT_CLOCK_RATE equal to the relevant high speed clock and saves this value to be used for CPUs with multiple level high speed clocks. Thus, if a particular CPU has 12 MHz and 6 MHz high speed clocks, monitor 40 must determine which high speed clock the CPU is at before monitor 40 reduces power so it may reestablish the CPU at the proper high speed clock when the CPU awakens. At Step 270 , the Save_clock_rate is set equal to the CURRENT_CLOCK_RATE determined. Save_clock_rate 270 is not used when there is only one high speed clock for the CPU. Monitor 40 now continues to SLEEPCLOCK 230 , where a pulse is sent to the hardware selector (shown in FIG. 3 ) to put the CPU clock to sleep (i.e., lower or stop its clock frequency). The I/O port hardware sleep clock is at much lower oscillations than the CPU clock normally employed.
[0048] At this point either of two events can happen. A system/application interrupt may occur or a real-time clock interrupt may occur. If a system/application interrupt 290 occurs, monitor 40 proceeds to interrupt routine 300 , processing the interrupt as soon as possible, arming interrupt I/O at Step 310 , and returning to determine whether there has been an interrupt (Step 320 ). Since in this case there has been an interrupt, the Save_clock_rate is used (Step 330 ) to determine which high speed clock to return the CPU to and SAVE POWER subroutine 250 is exited at RETURN 340 . If, however, a system/application interrupt is not received, the SAVE POWER subroutine 250 will continue to wait until a real-time clock interrupt has occurred (Step 320 ). Once such an interrupt has occurred, SAVE POWER subroutine 250 will continue to wait until a real-time clock interrupt has occurred (Step 320 ). Once such an interrupt has occurred, SAVEPOWER subroutine 250 will execute interrupt loop 320 several times. If however, control is passed when the sleep clock rate was zero, in other words, there was no clock, the SAVE POWER subroutine 250 will execute interrupt loop 320 once before returning the CPU clock to the Save_clock_rate 330 and exiting (Step( 340 )).
[0049] Consider now FIG. 2 d which is a flowchart showing ACTIVITY branch 70 triggered by an application/system activity request via an operating system service request interrupt. ACTIVITY branch 70 begins with reentry protection. Monitor 40 determines at Step 350 whether Busy_I has been set to BUSY_FLAG. If it has, this means the system is already in ACTIVITY branch 70 and cannot be interrupted. If Busy_I=BUSY_FLAG, monitor 40 exits to RETURN I 160 , which is an indirect vector to an old activity vector interrupt for normal processing, via an interrupt vector after the operating svstem performs the requested service.
[0050] If however, the Busy_I flag does not equal BUSY_FLAG, which means ACTIVITY branch 70 is not being accessed, monitor 40 determines at Step 360 if the BUSY_A flag has been set equal to BUSY_FLAG. If so, control will be returned to the system at this point because ACTIVITY branch 70 is already being used and cannot be interrupted. If the Busy_A flag has not been set, in other words, Busy_A does not equal BUSY_FLAG, monitor 40 sets Busy_A equal to BUSY_FLAG at Step 370 so as not to be interrupted during execution of ACTIVITY branch 70 . At Step 380 the Power_level is determined. If Power_level equals zero, monitor 40 exits ACTIVITY branch 70 after clearing the Busy_A reentry flag (Step 390 ). If however, the Power_level does not equal zero, the CURRENT_CLOCK_RATE of the I/O hardware is next determined. As was true with Step 270 of FIG. 2C , Step 400 of FIG. 2 d uses the CURRENT_CLOCK_RATE if there are multiple level high speed clocks for a given CPU. Otherwise, CURRENT_CLOCK_RATE always equals the CPU high speed clock. After the CURRENT_CLOCK_RATE is determined (step 400 ), at Step 410 Idle_tick is set equal to the constant START_TICKS established for the previously determined CURRENT_CLOCK_RATE. T(off) intervals are established based on the current high speed clock that is active.
[0051] Monitor 40 next determines that a request has been made. A request is an input by the application software running on the computer, for a particular type of service needed. At Step 420 , monitor 40 determines whether the request is a CRITICAL I/O. If the request is a CRITICAL I/O, it will continuously force T(on) to lengthen until the T(on) is greater than the T(off), and monitor 40 will exit ACTIVITY branch 70 after clearing the Busy_A reentry flag (Step 390 ). If, on the other hand, the request is not a CRITICAL I/O, then the Activity_tick is incremented by one at Step 430 . It is then determined at Step 440 whether the Activity_tick now equals ACTIVITY_MAXTICKS. Step 440 allows a smoothing from a CRITICAL I/O, and makes the system ready from another CRITICAL I/O during Activity_tick T(on) intervals. Assuming Activity_tick does not equal ACTIVITY_MAXTICKS, ACTIVITY branch 70 is exited after clearing the Busy_A reentry flag (Step 390 ). If, on the other hand, the Activity_tick equals constant ACTIVITY_MAXTICKS, at Step 450 Activity_tick is set to the constant LEVEL_MAXTICKS established for the particular Power_level determined at Step 380 .
[0052] Now monitor 40 determines whether an interrupt mask exists (Step 460 ). An interrupt mask is set by system/application software. Setting it to NOT_AVAILABLE creates a continuous T(on) state. If the interrupt mask equals NOT_AVAILABLE, there are no interrupts available at this time and monitor 40 exits ACTIVITY branch 70 after clearing the Busy_A reentry flag (Step 390 ). If, however, an interrupt is AVAILABLE, monitor 40 determines at Step 470 whether the request identified at Step 420 was for a SLOW I/O_INTERRUPT. Slow I/O requests may have a delay until the I/O device becomes “ready”. During the “make ready” operation, a continuous T(off) interval may be set up and executed to conserve power. Thus, if the request is not a SLOW I/O_INTERRUPT, ACTIVITY branch 70 is exited after clearing the Busy_A reentry flag (Step 390 ). If, however, the request is a SLOW I/O_INTERRUPT, and time yet exists before the I/O device becomes “ready”, monitor 40 then determines at Step 480 whether the I/O request is COMPLETE (i.e., is I/O device ready?). If the I/O device is not ready, monitor 40 forces T(off) to lengthen, thereby forcing the CPU to wait, or sleep, until the SLOW I/O device is ready. At this point it has time to save power and ACTIVITY branch 70 enters SAVE POWER subroutine 250 previously described in connection with to FIG. 2C . If, however, the I/O request is COMPLETE, control is returned to the operating system subsequently to monitor 40 exiting ACTIVITY branch 70 after clearing Busy_A reentry flag (Step 390 ).
[0053] Self-tuning is inherent within the control system of continuous feedback loops. The software of the present invention can detect when CPU activity is low and/or CPU temperature is high enough to be of concern and therefore when the power conservation and thermal management aspect of the present invention may be activated. To detect when CPU temperature is high enough to be of concern, the power and thermal management software monitors a thermistor on the PWB board adjacent the CPU (or mounted directly on or in the CPU if the CPU includes a thermistor). In one embodiment of the present invention, the software monitors the thermistor 18 times/sec through an A/D converter. If no power is being conserved and the temperature of the thermistor is within acceptable parameters, then monitoring continues at the same rate. If, however, the temperature of the thermistor is rising, a semaphore is set to tell the system to start watching CPU temperature for possible thermal management action. Each CPU has a temperature coefficient unique to that specific CPU. Information on how long it takes to raise the temperature and at what point intervention must occur to prevent performance degradation must be derived from information supplied with the CPU or through testing.
[0054] According to one embodiment of the invention, a counter is set in hardware to give an ad hoc interrupt (counter is based on coefficient of temperature rise). The thermal management system must know how long it takes CPU temperature to go down to minimize temperature effect. If the counter is counting down and receives an active power interrupt, the ad hoc interrupt is turned off because control has been regained through the active power and thermal management. The result is unperceived operational power savings. The ad hoc interrupt can be overridden or modified by the active power interrupt which checks the type gradient i.e., up or down, checks the count and can adjust the up count and down count ad hoc operation based on what the CPU is doing real time. If there are no real time interrupts, then the timer interval continually comes in and monitors the gradual rise in temperature and it will adjust the ad hoc counter as it needs it up or down. The result is dynamic feedback from the active power and thermal management into the ad hoc timer, adjusting it to the dynamic adjustment based on what the temperature rise or fall is at any given time and how long it takes for that temperature to fall off or rise through the danger point. This is a different concept that just throwing a timer out ad hoc and letting it run.
[0055] For example, assume that the CPU being used has a maximum safe operating temperature of 95 degrees C. (obtained from the CPU spec sheet or from actual testing). Assume also that a thermistor is located adjacent the CPU and that when the CPU case is at 95 decrees C., the temperature of the thermistor may be lower since it is spaced a distance from the CPU (such as 57 degrees C.). A determination should be made as to how long it took the CPU to reach 95 degrees. If it took an hour, the system may decide to sample the thermistor every 45 minutes. Once the CPU is at 95 degrees, CPU temperature may need to be sampled every minute to make sure the temperature is going, down, otherwise, the temperature might go up, i.e., to 96 degrees. If 5 minutes are required to raise CPU temperature from 95 to 96 degrees, CPU temperature sampling must be at a period less than 5 minutes—i.e., every 3 or 1 minutes. If the temperature is not going down, then the length of the rest cvcles should be increased. Continual evaluation of the thermal read constant is key to knowing when CPU temperature is becoming a problem, when thermal management intervention is appropriate and how much time can be allowed for other things in the system. This decision must be made before the target temperature is reached. Once CPU temperature starts to lower, it is. O.K. to go back to the regular thermal constant number because 1) you have selected the right slice period, or 2) the active power portion of the active power and thermal management has taken over, so the sampling rate can be reduced.
[0056] Examples of source code that can be stored in the CPU ROM or in an external RAM device, according to one embodiment of the invention, are listed in the COMPUTER PROGRAMS LISTING section under: 1) Interrupt 8 Timer interrupt service—listed on pages ______ to ______; 2) CPU Sleep Routine—listed on pages ______ to ______; 3) FILE=FORCE5.ASM—listed on pages ______ to ______ ; and 4) FILE=Thermal.EQU—listed on pages ______ to ______.
[0057] Utilizing the above listed source code, and assuming that Interrupt 8 Timer interrupt service is the interrupt mask called at Step 240 of IDLE loop 60 or at Step 460 of ACTIVITY loop 70 , the procedure for thermal management is set up “Do Thermal Management if needed” after which the system must decide if there is time for thermal management “Time for Thermal Management?”. If there is time for thermal management, the system calls the file “force_sleep” if there is time to sleep (which also sleeps any PCI bus coupled to the CPU), or alternatively, could do a STI nop and a halt—which is an alternate way and does not get PCI devices and does not have a feedback loop from the power and temperature management systems. The “Force_sleep” file gets feedback from other power systems. Force_sleep does a jump to force5.asm, which is the PCI multiple sleep program. Are there speakers busy in the system? Is there something else in the system going on from a power management point of view? Are DMAs running in the system? Sleeping may not be desirable during a sound cycle. It needs to know what is going on in the system to do an intelligent sleep. The thermal management cares about the CPU and cares about all the other devices out there because collectively they all generate heat.
[0058] There are some equations in the program that are running—others that may or may not be running. “tk” is the number of interrupts per second that are sampled times the interval that is sampled over. “it” represents a thermal read constant and the thermal read constant in the present embodiment is 5. In the code, the thermal read constant is dynamically adjusted later depending on what the temperature is. Thus, this is the starting thermal read interval, but as the temperature rises, reading should be more often and the cooler it is, reading should be less often than 5 minutes—e.g., 10 minutes. The thermal read constant will adjust. TP 1 or TP 2 represents what percentage of the CPU cycles do we want to sample at—for example, TP 7 set at 50=the number of interrupts that have to occur over some period of time such that if we take that number that going to represent every so many clock cycles that go by before we sample and sleep the CPU. These equations are variable. Other equations can also be used.
[0059] Thus, one concept of the present invention is that there are various levels of temperature that require testing in relationship to the hottest point to be managed. The sample period will change based on temperature and active feedback. Active feedback may be required even though thermal management has determined that the CPU temperature is too high and should be reduced (by slowing or stopping the CPU clock). CPU clock speed may not be reduced because other system things are happening—the result is intelligent feedback. The power conservation and thermal management systems asks the CPU questions such as are you doing something now that I cannot go do? If not, please sleep. If yes, don't sleep and come back to me so that I can reset my count. The result is a graduated effect up and graduated effect down and the thermal read constant time period adjusts itself in response to CPU temperature. Performance taken away from the user during power conservation and thermal management control is balanced against critical I/O going on in the svstem.
[0060] Active power and thermal management cooperates with standard CPU power management so that when standard power management gets a chance to take over the active feedback can start degrading even though the temperature has not. Existing power/thermal management systems turn on and stay on until the temperature goes down. Unfortunately, this preempts things in the system. Such is not the case in the environment of the present invention. The same sleep manager works in conjunction with power conservation and thermal management—the sleep manager has global control. As a example, while CPU temperature may be rising or have risen to a level of concern, the system may be processing critical I/O, such as a wave file being played. With critical I/O, the system of the present invention will play the wave file without interruption even though the result may be a higher CPU temperature. CPUs do not typically overheat all at once. There is a temperature rise gradient. The system of the present invention takes advantage of the temperature rise gradient to give a user things that affect the user time slices and take it away from him when its not affected.
[0061] Thermal management can be also be achieved using a prediction mode. Prediction mode utilizes no sensors or thermistors or even knowledge as to actual CPU temperature. Prediction mode uses a guess—i.e. that the system will need the ad hoc interrupt once every 5 seconds or 50 times/second (=constant) and then can take it up or down based on what the system is doing with the active power and thermal management. The prediction theory can also be combined with actual CPU temperature monitoring.
[0062] Once the power conservation and thermal management monitor is activated, a prompt return to full speed CPU clock operation within the interval is achieved so as to not degrade the performance of the computer. To achieve this prompt return to full speed CPU clock operation, the preferred embodiment of the present invention employs some associated hardware.
[0063] Looking now at FIG. 3 which shows a simplified schematic diagram representing the associated hardware employed by the present invention for active power conservation and thermal management. When monitor 40 (not shown) determines the CPU is ready to sleep, it writes to an I/O port (not shown) which causes a pulse on the SLEEP line. The rising edge of this pulse on the SLEEP line causes flip flop 500 to clock a high to Q and a low to Q_. This causes the AND/OR logic (AND gates 510 , 520 , OR gate 530 ) to select the pulses travelling the SLEEP CLOCK line from SLEEP CLOCK oscillator 540 to be sent to and used by the CPU CLOCK. SLEEP CLOCK oscillator 540 is a slower clock than the CPU clock used during normal CPU activity. The high coming from the Q of flip flop 500 ANDed ( 510 ) with the pulses coming from SLEEP CLOCK oscillator 540 is ORed ( 530 ) with the result of the low on the Q_of flip flop 500 ANDed ( 520 ) with the pulse generated along the HIGH SPEED CLOCK line by the HIGH SPEED CLOCK oscillator 550 to yield the CPU CLOCK. When the I/O port designates SLEEP CLOCK, the CPU CLOCK is then equal to the SLEEP CLOCK oscillator 540 value. If, on the other hand, an interrupt occurs, an interrupt—value clears flip flop 500 , thereby forcing the AND/OR selector (comprising 510 , 520 and 530 ) to choose the HIGH SPEED CLOCK value, and returns the CPU CLOCK value to the value coming from HIGH SPEED CLOCK oscillator 550 . Therefore, during any power conservation and/or thermal management operation on the CPU, the detection of any interrupt within the system will restore the CPU operation at full clock rate prior to vectoring and processing the interrupt.
[0064] It should be noted that the associated hardware needed, external to each of the CPUs for any given system, may be different based on the operating system used, whether the CPU can be stopped, etc. Nevertheless, the scope of the present invention should not be limited by possible system specific modifications needed to permit the present invention to actively conserve power and manage CPU temperature in the numerous available portable computer systems. For example two actual implementations are shown in FIGS. 4 and 5 , discussed below.
[0065] Many VSLI designs today allow for clock switching of the CPU speed. The logic to switch from a null clock or slow clock to a fast clock logic is the same as that which allows the user to change speeds by a keyboard command. The added logic of monitor 40 working with such switching logic, causes an immediate return to a fast clock upon detection of any interrupt. This simple logic is the key to the necessary hardware support to interrupt the CPU and thereby allow the processing of the interrupt at full speed.
[0066] The method to reduce power consumption under MS-DOS employs the MS-DOS IDLE loop trap to gain access to the “do nothing” loop. The IDLE loop provides special access to application software and operating system operations that are in a state of IDLE of low activity. Careful examination is required to determine the activity level at any given point within the system. Feedback loops are used from the Interrupt 21H service request to determine the activity level. The prediction of activity level is determined by interrupt 21H requests, from which the present invention thereby sets the slice periods for “sleeping” (slowing down or stopping) the CPU. An additional feature allows the user to modify the slice depending on the activity level of interrupt 21H. The method to produce power conservation under WINDOWS employs real and protect modes to save the power interrupt which is called by the operating system each time WINDOWS has nothing to do.
[0067] Looking now at FIG. 4 , which depicts a schematic of an actual sleep hardware implementation for a system such as the Intel 80386 (CPU cannot have its clock stopped). Address enable bus 600 and address bus 610 provide CPU input to demultiplexer 620 . The output of demultiplexer 620 is sent along SLEEPCS—and provided as input to OR gates 630 , 640 . The other inputs to OR gates 630 , 640 are the I/O write control line and the I/O read control line, respectively. The outputs of these gates, in addition to NOR gate 650 , are applied to D flip flop 660 to decode the port. “INTR” is the interrupt input from the I/O port (peripherals) into NOR gate 650 , which causes the logic hardware to switch back to the high speed clock. The output of flip flop 660 is then fed, along with the output from OR gate 630 , to tristate buffer 670 to enable it to read back what is on the port. A 1 of the above-identified hardware is used by the read/write I/O port (peripherals) to select the power saving “Sleep” operation. The output “SLOW_” is equivalent to “SLEEP” in FIG. 2 , and is inputted to flip flop 680 , discussed later.
[0068] The output of SLEEP CLOCK oscillator 690 is divided into two slower clocks by D flip flops 700 , 710 . In the particular implementation shown in FIG. 4 , 16 MHz sleep clock oscillator 690 is divided into 4 MHz and 8 MHz clocks. Jumper J 1 selects which clock is to be the “SLEEP CLOCK”.
[0069] In this particular implementation, high speed clock oscillator 720 is a 32 MHz oscillator, although this particular speed is not a requirement of the present invention. The 32 Mz oscillator is put in series with a resistor (for the implementation shown, 33 ohms), which is in series with two parallel capacitors (10 pF). The result of such oscillations is tied to the clocks of D flip flops 730 , 740 .
[0070] D flip flops 680 , 730 , 740 are synchronizing flip flops; 680 , 730 were not shown in the simplified sleep hardware of FIG. 2 . These flip flops are used to ensure the clock switch occurs only on clock edge. As can be seen in FIG. 4 , as with flip flop 500 of FIG. 2 , the output of flip flop 740 either activates OR gate 750 or OR gate 760 , depending upon whether the CPU is to sleep (“FASTEN_”) or awaken (“SLOWEN_”).
[0071] OR gates 750 , 760 and AND gate 770 are the functional equivalents to the AND/OR selector of FIG. 2 . They are responsible for selecting either the “slowclk” (slow clock, also known as SLEEP CLOCK) or high speed clock (designated as 32 MHz on the incoming line). In this implementation, the Slow clock is either 4 MHz or 8 MHz, depending upon jumper J 1 , and the high speed clock is 32 MHz. The output of AND gate 770 (ATUCLK) establishes the rate of the CPU clock, and is the equivalent of CPU CLOCK of FIG. 2 . (If the device includes a PCI bus, the output of AND gate 770 may also be coupled to the PCI bus if it is to utilize the clock signal.)
[0072] Consider now FIG. 5 , which depicts a schematic of another actual sleep hardware implementation for a system such as the Intel 80286 (CPU can have its clock stopped). The Western Digital FE3600 VLSI is used for the speed switching with a special external PAL 780 to control the interrupt gating which wakes up the CPU on any interrupt. The software power conservation according to the present invention monitors the interrupt acceptance, activating the next P(i)deltaTi interval after the interrupt.
[0073] Any interrupt request to the CPU will return the system to normal operation. An interrupt request (“INTRQ”) to the CPU will cause the PAL to issue a Wake Up signal on the RESCPU line to the FE3001 (not shown) which in turn enables the CPU and the DMA clocks to bring the system back to its normal state. This is the equivalent of the “Interrupt_” of FIG. 2 . Interrupt Request is synchronized to avoid confusing he state machine so that Interrupt (INT-DET) will only be detected while the cycle is active. The rising edge of RESCPU will wake up the FE 3001 which in turn releases the whole system from the Sleep Mode.
[0074] Implementation for the 386SX is different only in the external hardware and software power conservation loop. The software loop will set external hardware to switch to the high speed clock on interrupt prior to vectoring the interrupt. Once return is made to the power conservation software, the high speed clock cycle will be detected and the hardware will be reset for full clock operation.
[0075] Implementation for OS/2 uses the “do nothing” loop programmed as a THREAD running in background operation with low priority. Once the THREAD is activated, the CPU sleep, or low speed clock, operation will be activated until an interrupt occurs thereby placing the CPU back to the original clock rate.
[0076] Although interrupts have been employed to wake up the CPU in the preferred embodiment of the present invention, it should be realized that any periodic activity within the system, or applied to the system, could also be used for the same function.
[0077] While several implementations of the preferred embodiment of the invention has been shown and described, various modifications and alternate embodiments will occur to those skilled in the art. Accordingly, it is intended that the invention be limited only in terms of the appended claims.
Computor Programs Listing
[0000]
1) Interrupt 8 Timer interrupt service—pages 27 to 32. Interrupt 8 Timer interrupt service is loaded onto the CPU ROM or an external RAM and is an interrupt mask that may be called at Step 240 of IDLE loop 60 or at Step 460 of ACTIVITY loop 70 .
2) CPU Sleep Routine—page 33. CPU Sleep Routine is loaded onto the CPU ROM or an external RAM and is a file that may be called at Step 250 of IDLE loop 60 or ACTIVITY loop 70 .
3) FILE=FORCE5.ASM—pages 34 to 38. FILE=FORCES.ASM is a PCI multiple sleep program that is loaded onto the CPU ROM or an external RAM and is a file that may be called at Step 250 of IDLE loop 60 or ACTIVITY loop 70 .
4) FILE=Thermal.EQU—listed on page 39. FILE=Thermal.EQU is loaded onto the CPU ROM or an external RAM and is a file that may be called at STEP 240 of IDLE loop 60 or at Step 460 of ACTIVITY loop 70 . | A method for detecting temperature associated with a processor and, depending on the respective embodiment, detecting an amount of idle time, activity time, or idle time and activity time associated with the processor, results of detecting being used for controlling a clock speed. Yet other embodiments disclose, depending upon the respective embodiment, a method for detecting temperature and for determining an amount of Input/Output (I/O), relative importance of Input/Output (I/O), and/or relative amount of time between Input/Output (I/O), associated with the processor, results of the detecting and measuring being used to control power dissipation associated with the processor. | 6 |
This application is a continuation-in-part of U.S. provisional patent application, Ser. No. 60/061,387, filed Oct. 7, 1997, the benefit of the filing date of which is hereby claimed under 35 U.S.C. 119(e) and 120.
FIELD OF THE INVENTION
The present invention generally pertains to a method and system for managing computer program execution to enable program monitoring and resource control, to enforce security, and to ensure compatibility, and more specifically, to a method and system in which software is rewritten and transformed before being executed on a computer so as to achieve these functions.
BACKGROUND OF THE INVENTION
The ability of individuals to freely access the Internet from computers or workstations poses fundamental problems for current state of the art computer systems. It is now possible to access data and programs from all over the world simply by opening a web page. Programs and Java™ or ActiveX™ code derived from unknown sources represent a tremendous network management and security problem for users and information systems (IS) managers. Code obtained from diverse and uncontrolled sources may violate the security and management service rules of the network on which it is executed.
On conventional systems, the execution of a program on a computer is governed only by the system services that are native to that computer. Consequently, networks of conventional systems face problems of scalability, manageability, integrity, and performance. First each conventional computer needs to have sufficient resources to support locally executing system services such as security, resource control, program monitoring, and task management. As a result, current systems place high resource demands on their client computers. Second, heterogeneous networks of conventional systems are hard to manage and administer, because there is no central point of control and it is difficult to establish uniform interfaces for remote management. Third, native services that are performed locally on client computers are vulnerable to security attacks and require that all client computers within a network be physically and virtually secured, which is a difficult and costly undertaking. Finally, executing services locally on client computers extracts a performance cost from the clients.
Clearly, a technique that provides greater latitude in controlling and managing software components and the behavior of applications within a network would provide a valuable advance over the current state of the art. This capability should be applicable to executable code that comes from both known and unknown sites. The method that is used should preferably examine any program as it enters the environment and before it is executed, breaking the application down into its constituent components. Those components should then be rewritten as necessary so that when the application is executed, it conforms to the security and management policy rules of the site. The management policies that might be implemented in a rewritten application can include, for example, performance tracking, usage metering, and revocable authorization to access services, or other elements of the computer/network. Moreover, the rewriting of the application components must be accomplished without altering the overall functionality of the program.
There is another important use for a technique that enables programs entering an environment to be observed, controlled, and managed prior to their execution. This technique can also be employed to retarget a program that has been developed for one machine (virtual or actual) architecture, so that the program runs on an entirely different machine architecture. Ideally, the translation and retargeting should be capable of implementation in a batch mode and be implemented with little or no user interaction. Such translation and retargeting is likely to become increasingly important to the computing world, to accommodate the ever increasing diversity of networks and machine architectures.
The techniques to accomplish the above-described functions are currently unavailable in the prior art. Accordingly, there is a clear need to develop and implement such capabilities, which has led to the present invention being developed.
SUMMARY OF THE INVENTION
In accord with the present invention, a method for modifying executable code received by a computer prior to its execution is defined. The method begins with the step of providing data that indicate how the executable code should be modified, if at all. In accordance with the data, the executable code is modified, producing modified executable code. This modified executable code is then made available for execution by the computer.
In one form of the present invention, the data define steps for modifying the executable code to enable monitoring and tracing during its execution. The method may then also include the step of storing information related to the monitoring and the tracing in either a local storage memory or a remote storage memory.
In another embodiment, the data define steps for ensuring the security of the computer and/or auditing the execution of the modified executable code by producing an audit trail.
If the modified executable code relates to sensitive information, the step of ensuring the security of the computer includes the steps of modifying the executable code to identify and store an indicator of a sensitivity of the sensitive information, enabling the sensitivity to be subsequently checked.
The data may define steps for optimizing the executable code to enable it to run faster, with less processing overhead. Or, the data may define steps for determining a threading behavior of the modified executable code, so that when the modified executable code is executed by the computer, it correctly performs context switches.
In another embodiment, the data define memory management operations, providing explicit memory management capabilities to the modified executable code that may not be provided in the executable code before modification.
In one form of the invention, the computer is a client connected to a server in a network. In this case, the step of changing the executable code is implemented by the server. The client then preferably implements the step of determining whether the executable code must be modified, and the method further comprises the step of transferring the program to the server to enable the server to apply the changes to the program to produce the modified program.
It is also contemplated that the data may define limits on either the number of system operations or the frequency with which the system operations are performed by the program, to limit denial of service attacks.
The step of determining whether the executable code must be modified preferably includes the step of parsing the program to analyze code contained therein, to determine if any of the code meets criteria for changes indicated in the file.
If the executable code is written for execution on a target platform that is different than that used by the computer, the method further includes the step of translating the executable code so that the modified executable code is executable on a software platform used by the computer.
Another aspect of the present invention is directed at apparatus that enables modifying a program that has been received, prior to executing the program. The apparatus includes a memory in which machine language instructions and criteria for changing the program are stored. A processor is included to execute the machine language instructions stored in the memory, causing the processor to implement a plurality of functions that are generally consistent with the steps of the method discussed above.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
The foregoing aspects and many of the attendant advantages of this invention will become more readily appreciated as the same becomes better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:
FIG. 1A is a general block diagram illustrating the functional components of a first embodiment of the present invention;
FIG. 1B is a general block diagram illustrating the functional components of a second embodiment of the present invention;
FIG. 2 is a more detailed block diagram showing functional components of the binary rewriting server of FIGS. 1A and 1B (which can be implemented on the same computer that runs the rewritten software);
FIG. 3 is a flow chart illustrating the logic implemented in modifying or rewriting a program in accord with the present invention;
FIG. 4 is a schematic illustration of a conventional personal computer, suitable for implementing the present invention; and
FIG. 5 is a block diagram of some of the functional components included in the personal computer of FIG. 4 .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference to FIGS. 1A and 1B , two exemplary embodiments of the present invention are illustrated. In FIG. 1A , a program provider host 10 provides a program or program snippet 12 (in an original representation) to a target host 18 . For example, the program provider host might be a server at a remote site to which target host 18 is connected over the Internet, or may be another computer, located at a remote site, and communicating with the target host over a wide area network. Indeed, the program provider host may simply be another computer at the local site, which is connected to the target host over a local area network. However, it is presumed that program provider host 10 is an untrusted source, and that program or program snippet 12 may not conform to the security policies or other criteria applied to programs implemented by target host 18 . Alternatively (or in addition), program or program snippet 12 may be written for a target platform or architecture that is different than that employed by target host 18 . It should be noted that as used in the claims that follow, the term “program” is intended to encompass the term “program snippet” as used in this disclosure.
Implicit in the embodiment shown in FIG. 1A is a local server (not shown) that keeps track of program transfers from untrusted sources, such as program provider host 10 , to target host 18 by virtue of being logically disposed on the network between target host 18 and program provider host 10 . For example, the server may be a proxy, a forwarder, may implement a firewall, or may be on a gateway or control a router through which program or program snippet 12 is directed to target host 18 . Before the program or program snippet provided by program provider host 10 can be run by target host 18 , the server directs it to a binary rewriting server 14 , which produces a rewritten program or program snippet 16 (having an internal representation). This rewritten program is then made available to target host 18 for execution. It is contemplated that the binary rewriting server and the target host may be the same computer. Binary rewriting server 14 rewrites the original program or program snippet to include any changes required to make program or program snippet 12 conform to the site-specific properties of programs executed by target host 18 . Alternatively, the changes introduced by binary rewriting server 14 may enable the program or program snippet originally written to execute on a different target platform or architecture to be executable on that employed by target host 18 . For example, code written to execute under Java may be rewritten and retargeted to execute on an ActiveX platform. It is also contemplated that code written to execute on one processor might be rewritten to execute on a different type of processor using the present invention.
By placing the server between the target host and the program provider host, the number of data transfers necessary to provide the program or program snippet to the binary rewriting service are reduced in the embodiment of FIG. 1 A. In contrast, FIG. 1B illustrates a different embodiment in which target host 18 is configured to send all programs or program snippets that it receives, which are of unknown or untrusted nature, through binary rewriting server 14 for approval, and as necessary, for rewriting. Binary rewriting server 14 thus has access to the program or program snippet in its original representation as provided by program provider host 10 , just as in the embodiment shown in FIG. 1 A. Further, binary rewriting server 14 makes the same types of changes to the program or program snippet in the embodiment shown in FIG. 1B as in the embodiment illustrated in FIG. 1 A. As a result of making these changes, the binary rewriting server produces a modified or rewritten program or program snippet 16 having the desired or appropriate internal representation for execution by target host 18 . This rewritten program meets site-specific constraints in connection with security, access constraints, and/or appropriate platform formatting.
FIG. 2 illustrates further details of the functions performed by binary rewriting server 14 . As noted previously, the program or program snippet 12 (in the original external representation) is input to the binary rewriting server. A block 22 in FIG. 2 indicates that the input code is parsed in its external representation form, as originally provided. This external format might be in the form of a Java bytecode or ActiveX component. A parser produces a program or program snippet 24 in an internal representation that typically comprises a set of rich data structures. Translation into the internal representation simplifies the design of components of the binary rewriting server and facilitates implementation of the code analysis and rewriting function. The internal representation of the program or program snippet is input to a code inspection and analysis engine 26 , which examines the codes comprising the internal representation of the program or program snippet for conformance with site-specific properties that are contained within a site-specific properties database 28 . The site-specific properties database includes data that have been previously independently set forth in a site-specific property specification 20 . Storage of the site-specific property specification in site-specific properties database 28 facilitates queries of the data by code inspection and analysis engine 26 to determine pertinent changes that should be made to the program or program snippet that is being inspected and analyzed. The code inspection and analysis engine extracts a summary of program properties 32 for the program or program snippet being analyzed for use in guiding a binary rewriting engine 30 . As an example, the summary of program properties for a Java applet may include the bounds of code regions, methods invoked on system resources, and/or types of resources manipulated by the program or program snippet. For purposes of optimization, code inspection and analysis engine 26 can consult with the site-specific properties database and omit gathering the summary information for those properties of the program or program snippet that do not appear in the database and therefore need not be enforced.
Binary rewriting engine 30 determines the set of properties to be enforced on the program by consulting site-specific properties database 28 . It performs a lookup based on the characteristics of the target host (and/or of the user) and an identifier for the program being instrumented, such as its digital hash, name, and/or origin. Thereafter, the binary rewriting engine compares the properties required of the program or program snippet against summary of program properties 32 and determines each place in the instruction stream for the program or program snippet where the desired properties obtained from the site-specific properties database may be violated. The binary rewriting engine then inserts appropriate enforcement code at or before each such location in the program or program snippet. The nature of the code that is added, e.g., for enforcement, depends upon the property that is being addressed, which may be specified in the site-specific properties database. Alternatively, the code that is added to the program or program snippet may be generated internally by binary rewriting engine 30 .
For example, if the site-specific properties database indicates that a program destined to be executed on a real time system should yield its usage of the processor after a maximum of N consecutive instructions, binary rewriting engine 30 would insert a call to a system yield routine for each execution path of N instructions. Further, the instruction sequence that is inserted into the program or program snippet may be derived from the site-specific properties database, or may be hard-coded, or deduced by binary rewriting engine 30 . Other examples of properties and the mechanism used for enforcing requirements of a site when the program or program snippet is executed are discussed below.
Binary rewriting engine 30 produces rewritten program or program snippet 16 (in the internal representation), which includes any code additions made by the binary rewriting engine. A block 34 provides for the translation and writing of the rewritten program or program snippet from the internal representation to the representation of the program suitable for execution on the target, as indicated in a block 38 . The choice of the representation or format of the program provided in block 38 depends upon the system that is running upon the target host. Since the preferred embodiment of the present invention ensures that the rewritten program provided in block 38 is inherently self-protecting, the target representation need not be amenable to security examinations. Accordingly, rewriting an original representation that was provided in Java to a target representation in ActiveX has the advantage of assuring the security properties provided by the Java runtime are maintained, while taking advantage of a substantially lower overhead and higher performance provided by the ActiveX translation of the code originally provided to the binary rewriting server. In addition, rewriting from the original representation back to the same representation enables transparent insertion of security checks and other provisions as set forth in site-specific properties database 28 .
Once the rewriting has been performed, the binary rewriting engine may also attach a certificate of approval, as implied by certification module 36 . The certificate of approval attached to the final, self-protecting code by certification module 36 is not necessary if the connection between the server and the target host is secure (e.g., if both reside on the same desktop and communicate via a secure channel). Depending upon the modes of attack anticipated against an internal network, the certification scheme may range from a simple source authentication that is based on addresses in the code, to a more sophisticated tamper-proof certificate.
Once the rewritten code, and/or translated code, reaches the target host, the properties specified in the site-specific properties database are either assured statically, or will be dynamically self-assured by the modified or rewritten program, during its execution. Therefore, it is not necessary for the target host to perform any further checking or enforcement of properties specified in the site-specific properties database, since all necessary changes to meet the criteria of the site-specific properties database will have already been added to the modified or rewritten program or program snippet.
FIG. 3 provides further details of the logic implemented during rewriting of a program or program snippet 12 . A block 40 indicates that a server operates in a looping mode, waiting for a program or program snippet to be transferred to or otherwise directed at the target host for execution. Upon detecting program or program snippet 12 in its original representation, the server parses the program or program snippet, generating an internal representation of it as indicated in a block 42 . A decision block 44 determines if the internal representation of the program or program snippet is consistent. If not, a block 46 indicates that the attempt to parse the program has failed, which would preclude the program input to the rewriting system from being executed on the target host. However, assuming that the attempt to parse the program and generate an internal representation of the code succeeds, a block 48 provides that a list of the desired properties is extracted from the program or program snippet, based upon a comparison with the properties in the site-specific properties database as indicated in a block 50 .
A decision block 52 then determines if the property list is empty, which would only occur if the program that was input satisfies all the site-specific properties. If not, a block 54 examines the program and extracts the summary information. Next, a block 56 provides for determining where the program or program snippet violates the desired properties indicated in the properties database (if any). For example, if the program or program snippet attempts to access objects for which it does not have permissions, it is likely to violate the desired properties relating to access of those objects.
A decision block 58 determines if the violation list output from block 56 is empty, and if not, a block 60 rejects further execution of the program, since it cannot be modified to satisfy the site-specific properties. Conversely, if the violation list is empty, the logic continues with a block 62 . In block 62 , the logic determines the code that is necessary to be inserted into the program or program snippet to enforce the properties that are specific to the site. In addition, a block 64 determines where the enforcement code should be inserted within the program so that in a block 66 , the enforcement code can be added.
If decision block 52 has a property list that is empty, and also, after block 66 is executed, a decision block 68 determines if the program must be translated to execute on the target host. If so, a block 70 determines a suitable target representation for the code comprising the program. Next, a block 72 translates the code from its internal representation (corresponding to the form in which it was input) to an appropriate representation suitable to be executed by the target host. Thereafter, a block 74 provides for writing out the translated code output from block 72 . Also, if no translation was necessary in decision block 68 , block 74 writes out the code without translation.
A decision block 76 determines if a certificate is necessary to facilitate execution of the program. If so, a block 78 provides for attaching the certificate to the rewritten program or program snippet. Thereafter, or if no certificate is necessary, block 38 provides for output of the program in the target representation format.
EXAMPLES OF SYSTEM PROPERTIES
To illustrate the operation of the present invention for rewriting code in regard to security criteria, the following example shows how file access by an applet can be limited to only read files under the /public directory of a file system. Note that the example shows the source code, while in fact, the present invention would operate with the corresponding binary code. First, the appropriate security identifiers (SIDs) and permissions must be defined. The applet SID is used to represent applet threads, and the public-file SID is used to represent files under the /public directory. Furthermore, the fs.read permission is employed to represent the right to read files. A policy specification defines a mapping from the file system name space to these security identifiers as follows:
<namespace name=“fs” direction=“left-to-right” separator=“/”>
<node path=“/public” map=“incl”>
<name>public-file</name>
</node> <namespace>
This specification defines a new namespace, called fs, whose names are interpreted from the left to the right and which uses the slash character “/” to separate path components. The namespace has one node with path /public. As indicated by the map attribute, all names in the namespace that have this path as a prefix, including the path /public itself, map to the public-file SID. It is necessary to grant applets read access to public files. Thus the fs.read tag is added to the access matrix entry for the SIDs applet and public-file (not shown). It is then necessary to define how and when the enforcement manager is invoked from applets and from the classes that provide file system access. Due to space constraints, this process is only shown for a stripped version of class java.io.FileInputStream, which provides read access to files. The specification for other relevant classes, such as java.io.FileOutputStream or java.applet.Applet is omitted. The specification for class java.io.FileInputStream and the corresponding rewritten code are as follows:
<class name=“java.io.FileInputStream”>
<constructor name=“FileInputStream(String)”>
<register for =“object” from=“param” index=“0” namespace=“fs”/>
</constructor> <method name=“int read( )”>
<check on=“object”>
<tag>fs.read</tag>
</check>
</method>
</class> public class java.io.FileInputStream {
public FileInputStream(String name) {
EnforementManager.register(this, name, “fs”); . . .
} public int read ( ) }
EnforcementManager.check(this, “fs.read”); . . .
}
}
The specification requires that two calls to the enforcement manager be injected into class java.io.FileInputStream. First, a register operation has to be injected into the constructor. This operation associates the new file input stream object with the SID corresponding to the String parameter in the fs namespace. Second, an access check has to be inserted into the read method. This operation verifies that the current thread has the fs.read permission on the current file input stream object. Now, whenever a new file input stream object is created, the register operation is executed. The enforcement manager queries the security policy service for the corresponding SID, providing the name argument and the fs namespace, and establishes a mapping from the object to the resulting SID. If the file input stream object represents a file under the /public directory, it will be associated with the public-file SID; if not, it will be associated with the null SID. On invocation of the read method, the access check is executed. The enforcement manager retrieves the SID for the calling thread, which is established at thread creation time and changed on protection domain transfers, and the SID for the file input stream from its security state. It then queries the security policy service for the legal permissions for this pair of SIDs and compares the result with the required permission fs.read. If the calling thread is an applet thread and the file input stream object is associated with the public-file SID, the legal permissions include the required permission and the operation is complete. If the legal permissions do not include the required permission, the enforcement manager throws a security exception in the form of a java.lang.SecurityException object and thus terminates the call to the read method.
It is not contemplated that the site-specific properties applied in rewriting a program or program snippet in any way be limited to specific sets or types of properties. Instead, it is likely that many kinds or types of properties can be enforced on the active content of a rewritten program or program snippet with the present invention. Several useful examples illustrate the types of properties that can be applied for resource management, security, and auditing. In one example, the active content of the program may be prohibited from launching a denial of service attack by limited the amount of memory that the program can allocate. This limitation can be accomplished, for example, by inserting a code that checks before every call to a system memory allocator. Another modification to a program would prohibit attacks on virtual system resources, such as threads or windows, by limiting the number of threads or windows an applet may create or manipulate. The present invention can accomplish this modification by ensuring that any calls to thread or window create functions in the program originally input are preceded by inserted code that implements a counter increment-and-compare function. Such a modification will effectively limit the application's ability to launch denial of service attacks on virtual system resources.
It is also noted that security properties impose restrictions on a rewritten program tending to enhance or protect system integrity. For example, in current Java systems, a Java run time function is responsible for insuring that a network connection can only be initiated between an applet and its originating host. This limitation requires the run time code to perform a number of explicit, hard-coded checks. In connection with the present invention, these checks would be embedded in the code of the rewritten code by binary rewriting engine 30 , thereby obviating the need to encode the security policy into the Java run time code.
As a final example of how the present invention may be used to rewrite a program, the properties specified in the site-specific properties database may take the form of auditing directives. In this case, binary rewriting engine 30 would insert hooks into the program being rewritten where calls are made to auditing functions. For example, start-stop auditing can be performed in a rewritten program using the present invention by adding a call in the program to an audit function for thread creation and deletion. Currently, implementing auditing requires the cooperation of either a system implementer or an active content provider. In contrast, use of the present invention would avoid the need for such cooperation.
Broadened Application of the Invention
The present invention enables administrators and other users of computer systems to enforce site-specific resource usage constraints, auditing requirements, security checks, and other parameters on code of both known and unknown origin. In addition, the invention permits the translation of code from one source binary format to a different binary format that is suitable for the target host to execute. While the preceding disclosure has contained a number of specific examples illustrating how the present invention can be used, this disclosure should not be construed as limiting on the scope of the invention, but rather as illustrative of how several preferred embodiments of the invention are implemented. Many other variations of the invention are contemplated, as noted below. Using the binary rewriting engine, it is possible to accomplish a number of other variations in the details of the present invention that are not specifically discussed above. These variations may optionally include or exclude certain steps that have been noted in the examples discussed above, since by adding or excluding the steps, installation requirements for a specific application of the invention can be better served, and the cost of deployment, administration, and/or implementation can be reduced.
It is contemplated that the binary rewriting service can run on replicated server computers that share server-state, load-balancing the incoming request between servers in a server pool, and providing redundancy in the face of hardware or software failures. However, smaller installations may employ a single server computer, or even on a single desktop machine for implementing the binary rewriting service, as appropriate to reduce installation costs. Furthermore, the binary rewriting server may be in the same machine as the target machine or the provider machine, thereby reducing requirements for multiple computers to carry out the present invention in very small systems.
It may be necessary for the server that implements the binary rewriting service to track the current state of the target host in order to perform its function. For instance, in the case of Java programs, the server responsible for rewriting programs may need to know about other programs that are installed on the target host. One method of implementing access to state information is for the binary rewriting server to track all changes to the target host in the persistent memory of the binary rewriting server, thereby avoiding the need to transfer the state from the target host to the binary rewriting server. While this approach reduces the communication requirements and avoids an extra protocol implementation, it introduces the problems of persistence and fault tolerance. Consequently, it is contemplated that an alternative implementation of the present invention would employ a stateless server and direct the clients to upload necessary state information to the server via a pre-established transfer protocol, as required for rewriting any incoming program snippet.
When practicing the present invention, it is likely that there would be multiple target host computers or workstations connect with a single binary rewriting server. While the above description has omitted discussion of multiple target hosts in order to reduce ambiguity, it should be apparent that each target host in a group of target hosts will behave in the manner described above in connection with the single target host shown in the drawings. The external representation format, internal processing format, and the destination representation format of the program or program snippet may all be the same, or any pair may be identical. Further, the audit trail may either be kept locally on the target host or may be transmitted over the network to a security server.
Certification may be in the form of a public-key based tamper proof certificate, or an authorization embedded in the program, or implicit (e.g., included in the network originator address). If a program or program snippet cannot be modified to conform to site-specific properties or criteria, the binary rewriting engine may send an error response to the target host. Alternatively, the server may transparently send a program which, when executed, alerts the system that includes the target host that an error has occurred. Another management service can be provided to include enterprise-wide program revocation, by which one or more server agents are used to revoke the execution rights of admitted code instantaneously if it cannot be rewritten as described above.
Computer System Suitable for Implementing the Present Invention
With reference to FIG. 4 , a generally conventional personal computer 300 is illustrated, which is suitable for use in connection with practicing the present invention. Alternatively, a portable computer, or workstation coupled to a network may instead be used. The components of this personal computer are generally similar to those that would be used in each of these alternatives. The components of a server are substantially the same as those used in the personal computer shown in FIGS. 4 and 5 , but a server will be provided with substantially more hard drive capacity and memory than a personal computer. Accordingly, it is unnecessary to separately show details of a workstation, portable computer, or server.
Personal computer 300 includes a processor chassis 302 in which are mounted a floppy disk drive 304 , a hard drive 306 , a motherboard populated with appropriate integrated circuits (not shown), and a power supply (also not shown), as are generally well known to those of ordinary skill in the art. A monitor 308 is included for displaying graphics and text generated by software programs that are run by the personal computer. A mouse 310 (or other pointing device) is connected to a serial port (or to a bus port) on the rear of processor chassis 302 , and signals from mouse 310 are conveyed to the motherboard to control a cursor on the display and to select text, menu options, and graphic components displayed on monitor 308 by software programs executing on the personal computer. In addition, a keyboard 313 is coupled to the motherboard for user entry of text and commands that affect the running of software programs executing on the personal computer.
Personal computer 300 also optionally includes a compact disk-read only memory (CD-ROM) drive 317 into which a CD-ROM disk 330 may be inserted so that executable files and data on the disk can be read for transfer into the memory and/or into storage on hard drive 306 of personal computer 300 . (At this point, it should be noted that as used in this specification and in the claims that follow, the term “storage memory” includes electronic, optical, magnetic, and any other form of storage device in which data and machine instructions can be stored.) Personal computer 300 may implement the present invention in a stand-alone capacity, or may be coupled to a local area and/or wide area network as one of a plurality of such computers on the network that access one or more servers.
Although details relating to all of the components mounted on the motherboard or otherwise installed inside processor chassis 302 are not illustrated, FIG. 5 is a block diagram showing some of the functional components that are included. The motherboard has a data bus 303 to which these functional components are electrically connected. A display interface 305 , comprising a video card, for example, generates signals in response to instructions executed by a central processing unit (CPU) 323 that are transmitted to monitor 308 so that graphics and text are displayed on the monitor. A hard drive and floppy drive interface 307 is coupled to data bus 303 to enable bi-directional flow of data and instructions between the data bus and floppy drive 304 or hard drive 306 . Software programs executed by CPU 323 are typically stored on either hard drive 306 , or on a floppy disk (not shown) that is inserted into floppy drive 304 . The software instructions for implementing the present invention will likely be distributed either on floppy disks, or on a CD-ROM disk or some other portable memory storage medium. The machine instructions comprising the software application that implements the present invention will also be loaded into the memory of the personal computer for execution by CPU 323 .
A serial/mouse port 309 (representative of the two serial ports typically provided) is also bi-directionally coupled to data bus 303 , enabling signals developed by mouse 310 to be conveyed through the data bus to CPU 323 . It is also contemplated that a universal serial bus (USB) port may be included and used for coupling a mouse and other peripheral devices to the data bus. A CD-ROM interface 329 connects CD-ROM drive 317 to data bus 303 . The CD-ROM interface may be a small computer systems interface (SCSI) type interface or other interface appropriate for connection to and operation of CD-ROM drive 317 .
A keyboard interface 315 receives signals from keyboard 313 , coupling the signals to data bus 303 for transmission to CPU 323 . Optionally coupled to data bus 303 is a network interface 320 (which may comprise, for example, an ETHERNET™ card for coupling the personal computer or workstation to a local area and/or wide area network).
When a software program such as that used to implement the present invention is executed by CPU 323 , the machine instructions comprising the program that are stored on a floppy disk, a CD-ROM, a server, or on hard drive 306 are transferred into a memory 321 via data bus 303 . These machine instructions are executed by CPU 323 , causing it to carry out functions determined by the machine instructions. Memory 321 includes both a nonvolatile read only memory (ROM) in which machine instructions used for booting up personal computer 300 are stored, and a random access memory (RAM) in which machine instructions and data defining an array of pulse positions are temporarily stored.
Although the present invention has been described in connection with the preferred form of practicing it, those of ordinary skill in the art will understand that many modifications can be made thereto within the scope of the claims that follow. Accordingly, it is not intended that the scope of the invention in any way be limited by the above description, but instead be determined entirely by reference to the claims that follow. | A program or program snippet is rewritten to conform to site-specific properties prior to being executed by a target host. The program or program snippet directed to a target host from a known or unknown source is either intercepted by a server before reaching the target host or can be redirected from the target host to the server to effect its rewriting. The program is parsed in its external representation, converting it to an internal representation that is inspected and analyzed with reference to a site-specific properties database. A summary of the program's properties is then compared to the site-specific properties database by a binary rewriting engine, which produces a rewritten program in an internal representation. If appropriate, the program or program snippet is rewritten to convert it to a format suitable for execution on the target host. Furthermore, certifications may be added to the rewritten program to mark that the rewritten program obeys site-specific constraints. The rewriting service thus produces a program in an appropriate target representation that conforms to site-specific properties. These properties may relate to security, auditing, optimization, monitoring, threading, and/or management of the rewritten program. | 6 |
FIELD OF INVENTION
[0001] A seed depositing device is provided for use in the field of horticulture, for facilitating the handling and planting of seeds.
BACKGROUND OF THE INVENTION
[0002] Many people are increasingly concerned about the state of the environment and the nutritional value of foods produced by big agri-business. As part of this awareness and in an effort to make the environment a better place to live, many of these people are switching to organic and local food. Gardening has gained in popularity as a result. This horticultural invention was designed to facilitate one area of the gardening process that can cause much frustration to both the busy urban backyard gardener and the horticulturalist working in small private and commercial nurseries—the handling, deposition and planting of seeds, especially small seeds.
[0003] Working with seeds, many types of which are small and difficult to handle, can be an arduous task. Seeds can be difficult to manipulate and it can be strenuous on a gardener's body to spread them evenly along a furrow in a garden bed or distribute them evenly in soil flats. The challenge of planting seeds outdoors can be compounded by high winds, heat, rain and pests such as mosquitoes and black flies can further impede a gardener's work.
[0004] Hand-held devices available in the marketplace, such as those provided under the trademarks “Professional Seeder”, “Seed Spoon®”, and “Seedmaster II®”, are being marketed to aid in the handling, deposition and planting of seeds but improvements to those devices are needed in order to overcome disadvantages associated with their use and/or handling. The seed depositing device of the present invention provides such an improvement by its ease of use, effectiveness and robust, simple design.
SUMMARY
[0005] [Gerry: To be inserted when claims have been approved and finalized. This portion is just a repetition of the claims written in sentence format and, thus, need not be separately reviewed by you—when the claims are approved I will add a summary that corresponds to the claims.]
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] Embodiments of the invention are described in the following with reference to the following drawings in which like reference numerals refer to like elements throughout.
[0007] FIG. 1 is a side view of an exemplary seed depositing device in accordance with the invention, completely assembled and with a keycap in the open end.
[0008] FIG. 2 is a side view of an exemplary outer shell of the seed depositing device of FIG. 1 , having a single row of equally spaced openings.
[0009] FIG. 3 is a side view of a further exemplary outer shell having a single row of equally spaced sets of openings.
[0010] FIG. 4 is a side view of a still further exemplary outer shell having two slit openings, separated by a bridge.
[0011] FIG. 5 a is a side view of an exemplary inner core of the seed depositing device of FIG. 1 , having multiple rows of equally spaced dimples.
[0012] FIG. 5 b is a sectional view of the inner core of FIG. 5 a taken along line A-A.
[0013] FIG. 6 is a side view of a further exemplary inner core having multiple rows of equally spaced sets of dimples.
[0014] FIG. 7 is a side view of a still further exemplary inner core with a fixed cap.
[0015] FIG. 8 is a side view of a still further exemplary inner core having an extended core portion with a reduced diameter knob.
[0016] FIG. 9 is a side view of a still further exemplary inner core having multiple offset rows of equally spaced dimples.
[0017] FIG. 10 a is a longitudinal sectional view of an exemplary dual purpose keycap in position over the open end of the seed depositing device but showing only that part of the end of the seed depositing device to which this dual purpose keycap is fitted.
[0018] FIG. 10 b is a sectional view of the dual purpose keycap of FIG. 10 a taken along line B-B.
[0019] FIG. 11 is a side view of an exemplary keycap.
[0020] FIG. 12 is a side view of an exemplary cap.
[0021] FIG. 13 is a side view of an exemplary cap configured for covering the extended core portion of the inner core shown in FIG. 8 .
[0022] FIG. 14 is a side view of a further exemplary inner core of the seed depositing device which is similar to that shown by FIG. 5 a but for which the hollow center extends through to one end of the inner core so as to provide an open end, and with a closure component included to close the open end.
[0023] FIG. 15 is a longitudinal sectional view of the inner core of FIG. 14 showing the hollow center and closure component closing the end.
[0024] FIG. 16 is a top view of the inner core and closure component of FIG. 14 .
[0025] FIG. 17 is a side view of the closure component of FIGS. 14-16 , shown in isolation.
DETAILED DESCRIPTION
[0026] The seed depositing device 10 of the invention may be embodied or provided in the form of an implement, tool or apparatus for use in depositing seeds in a seed planting application.
[0027] Preferred embodiments of a seed depositing device 10 in accordance with the invention are illustrated by the drawings. The device 10 is comprised of a tubular outer shell 5 having a single row of openings 6 , 6 a or 6 b along its length, and a cylindrical inner core 15 fitted concentrically within the outer shell 5 and having rows of dimples 16 , 16 a or 16 b along the length of an outer surface of the inner core 15 for holding seeds, whereby the dimples 16 , 16 a or 16 b are alignable with corresponding openings 6 , 6 a or 6 b by manually rotating the inner core 15 and outer shell 5 relative to one another. When so aligned, the dimples 16 , 16 a or 16 b are exposed through corresponding openings 6 , 6 a or 6 b and may be loaded with seeds or, if previously loaded with seeds, may deposit those seeds during the course of a seed planting application. The outer diameter of the inner core 15 is only slightly smaller than the inner diameter of the outer shell 5 so that they fit together, concentrically, with sufficient resistance to rotation that the inner core 15 does not freely move or rotate in the outer shell 5 .
[0028] In a preferred embodiment in FIG. 1 , the outer shell 5 of the seed depositing device 10 has one row of openings 6 along its length. The openings 6 are equally spaced to match any one of several rows of correspondingly spaced dimples 16 along the length of the outer surface of the inner core 15 . In this particular embodiment, the outer shell 5 has a closed first end 2 and an open second end 3 . The inner core 15 is manually rotated relative to the outer shell 5 by means of a keycap 20 shaped for insertion through the open end 3 of the outer shell 5 and fitting into a receiving portion 25 , in the form of a groove, in a corresponding end 4 of the inner core 15 .
[0029] FIG. 2 shows the outer shell 5 of FIG. 1 in isolation, having one row of equally spaced openings 6 . FIGS. 3 and 4 show other, alternative arrangements of openings 6 a and 6 b , respectively, which might instead be used, as desired, for a given application. For instance, the outer shell 5 of FIG. 3 has a row of a spaced sets of openings 6 a , to align with correspondingly shaped and arranged sets of dimples 16 a (see FIG. 6 ). And, for example, the outer shell 5 of FIG. 4 has a row of slit openings 6 b which are shaped and positioned to align with a row of dimples 16 , 16 a or 16 b by rotating the outer shell 5 and inner core 15 relative to one another. A bridge 8 between the slit openings 6 b is preferred to be included to strengthen the outer shell 5 .
[0030] The outer shell 5 has an open end 3 for inserting the inner core 15 into the outer shell 5 . The opposite end 2 of the outer shell 5 is closed in the illustrated embodiments, in which the closed end 2 includes a hole 13 which may be used to facilitate the removal of the inner core 15 from within the outer shell 5 .
[0031] In the illustrated embodiments the outer shell 5 is transparent. This enables the user to see the dimples in the inner core 15 below it and may make it easier for the user to align the openings in the outer shell 5 over the dimples on rotation of the inner core 15 .
[0032] FIGS. 5 a and 5 b illustrate the inner core 15 of the seed depositing device 10 of FIG. 1 in isolation. Adjacent rows of equally spaced dimples 16 are positioned along the length of an outer surface of the inner core 15 . As stated, alternative dimple arrangements, such as the sets of dimples 16 a shown in FIG. 6 may alternatively be used with a correspondingly configured outer shell 5 , as desired, depending upon the intended planting application.
[0033] The inner core 15 may be a solid piece or, alternatively, to reduce material costs and weight, may have a hollow center 18 . A cross-section taken along line A-A of FIG. 5 a is shown in FIG. 5 b . The dimples 16 are depressions on the outer surface of the inner core 15 that do not penetrate to the hollow center 18 . The size, depth and spacing of the dimples can vary to accommodate different size seeds and/or having different desired spacing when planting. The outer surface of the inner core 15 includes a dimple-free portion 17 which is at least as wide as the openings 6 (or openings 6 a or slit openings 6 b , as applicable), to provide a position where seeds will not be exposed and, so, are prevented from exiting the openings 6 of the outer shell 5 when the seed depositing device 10 is being transported or stored.
[0034] Optionally, to provide more rows of dimples in a given diameter of inner core 15 and/or to reduce the diameter of the seed depositing device 10 without sacrificing the number of dimples 16 available for seeding, the inner core 15 may have offset rows of dimples 16 b , as shown in FIG. 9 . This configuration of offset rows of dimples 16 b is able to operate effectively in conjunction with an outer shell 5 having a row of slit openings 6 b , as shown in FIG. 4 .
[0035] As will be understood by the reader, various alternative configurations of dimples in the inner core 15 and openings in the outer shell 5 can be used depending on the type and size of the seed, the spacing required for the seed, and the preferences of the user, for a given application.
[0036] To operate the seed depositing device 10 , the concentric inner core 15 must be able to rotate relative to the outer shell 5 when an appropriate rotational force is applied, so as to position one of the rows of dimples 16 of the inner core 15 into alignment with the openings 6 of the outer shell 5 . There are many alternative means of achieving this rotation.
[0037] In one embodiment, for example, as illustrated in FIGS. 1 and 11 , rotation of the inner core 15 is accomplished by means of a keycap 20 having an insertion portion 21 and a gripping portion 22 . The insertion portion 21 is inserted through the open end 3 of the outer shell 5 . The insertion portion 21 of the keycap 20 has a key portion 26 that fits into a receiving portion 25 in the inner core 15 . In this example, the key portion 26 and receiving portion 25 function as a tongue-and-groove-type mating. This operates like a lock and key such that when the keycap 20 is inserted through the open end 3 of the outer shell 5 and the key portion 26 is fit into the receiving portion 25 , the inner core 15 can be manually rotated by a user by turning the gripping portion 22 of the keycap 20 .
[0038] As will be understood by the reader, many alternative configurations of caps and similar components may be used, as desired, to achieve relative rotation of the inner core 15 and outer shell 5 . FIGS. 10 a - 13 illustrate exemplary embodiments of caps which may be used to rotate the inner core 15 or to prevent the inner core 15 from rotating during transportation or storage of the seed depositing device 10 . For example, in an embodiment which employs a keycap 20 to rotate the inner core 15 when the seed depositing device 10 is in use, the keycap 20 could be replaced by a cap 30 as shown in FIG. 12 during transportation or storage of the seed depositing device 10 . The cap 30 has an insertion portion 21 and a gripping portion 22 , but no key portion 26 , so in use the inner core 15 is not rotated when cap 30 is turned.
[0039] To avoid the need for two caps in the foregoing embodiment, which switches between use of a keycap 20 and a cap 30 , for example, the embodiment of a dual purpose keycap 40 illustrated by FIGS. 10 a and 10 b may be used. The dual purpose keycap 40 has a channel 50 into which the open end 3 of the outer shell 5 is inserted. The dual purpose keycap 40 also has an insertion portion 46 with a key portion 26 that fits into the receiving portion 25 of the inner core 15 . To engage the inner core 15 , the dual purpose keycap 40 is pushed into the open end 3 of the outer shell 5 and rotated until the key portion 26 of the dual purpose keycap 40 is mated with the receiving portion 25 of the inner core 15 . In this position the inner core 15 is rotated by gripping and turning an outer gripping portion 42 of the dual purpose keycap 40 to manually turn the dual purpose key cap 40 . In use, this is done until the outer shell openings 6 , 6 a or 6 b have become aligned with the inner core dimples 16 , 16 a or 16 b . To disengage and close the device 10 , the dual purpose keycap 40 is rotated until the openings 6 , 6 a or 6 b are aligned with the dimple free row 17 of the inner core 15 , and then the dual purpose keycap 40 is pulled outward from the open end 3 of the outer shell 5 until the key portion 26 of the dual purpose keycap 40 is disengaged from the receiving portion 25 of the inner core 15 . When disengaged, the dual purpose key cap 40 is, again, slightly rotated to locate it in a position where the key portion 26 will be prevented from accidentally re-engaging the receiving portion 25 of the inner core 15 .
[0040] In a further exemplary embodiment shown by FIG. 8 , the inner core 15 itself may be constructed to extend beyond the open end 3 of the outer shell 5 , to enable the inner core 15 to be rotated by manually rotating an extended portion 27 of the inner core 15 . Optionally, a cap 24 as shown by FIG. 7 could be attached to and/or extend from the inner core 15 for use in manually rotated the inner core 15 . Additionally, an extension cap 35 , as shown in FIG. 13 , may be provided to lock the position of the inner core 15 with extended portion 27 when the seed depositing device 10 is being transported or stored, to prevent the inner core 15 from turning accidentally. The extension cap 35 is placed over the extended portion 27 and around the outer shell 5 , with a pin 28 of the extension cap 35 fitting into a pin receiving portion 29 of the extended portion 27 , and with the extension cap 35 configured to fit tightly over the outer shell 5 so as to resist rotation.
[0041] A further embodiment of the inner core 15 is shown by FIGS. 14-17 in which a hollow center 18 is extended to the end 4 of the inner core 15 , so that the inner core end 4 corresponds to an open end 54 of the hollow center 18 , and the hollow center 18 may be used to store seeds, if desired. In this embodiment the inner core 15 is configured to receive a closure component 52 to close the open end 54 and prevent seeds stored in the hollow center from escaping. In the illustrated embodiment, the inner core 15 is threaded in the wall of the hollow center 18 at the open end 54 to receive a closure component in the form of a screw-in plug 52 . A slot 56 is provided in the top of the screw-in plug 52 for receiving a suitable tool to be used to screw in the plug 52 .
[0042] The seed depositing device 10 is made of a non-flexible material such as hard plastic, wood, metal, plexiglass or fiberglass. A rigid plastic construction is preferred for its practicality and manufacturing cost. When plastic is used, the composition of the plastic should be of food grade if the seed depositing device 10 is intended to handle seeds for foods. It is preferable that the plastic be UV resistant if the seed depositing device 10 is intended for use in the outdoors, and recyclable, for safe environmental disposal.
[0043] Selectable components, as desired, may be color coded to assist in product identification and content referencing (for example, the inner core 15 and/or caps 20 , 30 and 40 ).
[0044] The outer shell 5 is preferably a light colored, transparent plastic. This allows the user to see the seeds, yet also provides some protection for light sensitive seeds in the field or in storage. Alternatively, the outer shell 5 may be opaque, if desired, in order to better protect light sensitive seeds during longer storage periods for example. The inner core 15 and the caps 20 , 30 and 40 are preferably made of a rigid opaque plastic for stability and durability.
[0045] The length and diameter of the seed depositing device 10 can be chosen to accommodate the particular application, as desired, to promote practical, cost effective seed depositing. For example, larger diameter devices 10 could have an inner core 15 with increased rows of dimples 16 . Particularly in these larger diameter depositing devices 10 , the inner core 15 preferably has a hollow center 18 to reduce the weight and production costs, and to be more environmentally friendly. The diameter, depth and spacing of the inner core dimples 16 may be varied to accept and distribute size-specific seeds. The longer the cylindrical seed depositing device 10 , the more seeds can be loaded into the device 10 , and, the wider the diameter of the device 10 , the more rows of dimples 16 the device 10 can hold, thus increasing the seed coverage of the bedding area.
[0046] To assemble the device 10 , the inner core 15 is inserted through the open end 3 of the outer shell 5 . Optionally, the inner core 15 may have a depression 12 that aligns with the hole 13 of the closed end 2 of the outer shell 5 , which may be used to provide further assistance to the user when removing the inner core 15 from the outer shell 5 . Depending on the embodiment, and whether the seed depositing device 10 is in use or in storage, a suitable cap may be placed on the open end 3 of the outer shell 5 , which then closes the unit.
[0047] To load the seed depositing device 10 of FIG. 1 with seeds, the inner core 15 is rotated through use of keycap 20 until a row of dimples 16 is aligned with the openings 6 of the outer shell 5 so as to expose that row of dimples 16 . Seeds are selected and manually placed into the empty, exposed dimples 16 . Once that row of dimples 16 is filled with seeds, as desired, the inner core 15 is again rotated until the next row of empty dimples 16 are aligned with the openings 6 of the outer shell 5 and, again, the empty, exposed dimples 16 are filled with seeds. This process is repeated until all of the rows of dimples 16 of the inner core 15 have been filled with seeds. The inner core 15 is then rotated until the dimple-free portion 17 of the inner core 15 is aligned with the openings 6 of the outer shell 5 in order to close the device. If the loaded seed depositing device 10 is to be stored, the openings 6 of the outer shell 5 should be positioned to rest at the dimple free area 17 of the inner core 15 and an appropriate storage cap (for example, such as cap 30 ) can be used.
[0048] To plant the seeds stored in the seed depositing device 10 , the seeds are deposited into furrows of a garden bed or into cells of soil flats. This is done by holding the seed depositing device 10 with the row of openings 6 of the outer shell 5 facing away from the ground and rotating the inner core 15 to expose the seeds of a row of dimples 16 through the openings 6 . Place the seed depositing device 10 just above a furrow in a garden plot or align the seed depositing device 10 over a specific area on a soil flat, as the case may be, and slowly turn the device 10 to deposit the row of seeds. Then, move the seed depositing device 10 to its next length along the furrow or planting area and repeat the foregoing steps until the device 10 is emptied or the desired seed coverage has been achieved. These steps can be completed with relatively little effort and in a relatively short time.
[0049] To clean the seed depositing device 10 , first remove any cap that may be on the open end 3 of the outer shell 5 . Insert a pin through the hole 13 of the outer shell 5 into the bottom depression 12 of the inner core 15 and push out the inner core 15 from the outer shell 5 . Once the components of the seed depositing device 10 have been cleaned and dried, the inner core 15 is reinserted into the outer shell 5 and, if desired position a cap into or onto the open end 3 of the outer shell 5 .
[0050] The embodiments described herein are exemplary only and it will be understood by the reader that other embodiments, and variations of those described herein, are possible without departing from the invention. The embodiments described here are not intended to limit the scope of the invention defined by the appended claims. | A seed depositing device designed to facilitate the uniform distribution of seeds during planting applications. The device includes a tubular outer shell having an open end and at least one opening along its length. An inner core is concentrically located in the outer shell and has at least one row of dimples along the length of an outer surface of the inner core for holding seeds. The inner core fits tightly enough in the outer shell to disallow free movement of the inner core within the outer shell. Rotation means is provided for manually rotating the inner core relative to the outer shell. The inner core is rotatable by the rotation means to align the at least one row of dimples with the at least one opening and expose the at least one row of dimples through the at least one opening. When the inner core is rotated so the openings of the outer shell are aligned with a row of dimples of the inner core, seeds are manually loaded into the exposed row of dimples through the openings of the outer shell. Each row of dimples is successively loaded in like manner until all dimples are loaded with seeds. A reversal of these steps is used to deposit the seeds onto a predetermined area. | 0 |
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