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CROSS REFERENCES
The present application is related to the following applications even dated herewith: Ser. No. 09/186,245, entitled, “Transform-domain correction of real-domain errors,” by inventors J. Mitchell et al., and Ser. No. 09/186,249, entitled, “Error reduction in transformed digital data,” by inventors M. Bright et al., which are incorporated herein in entirety by reference.
FIELD OF THE INVENTION
This invention relates to transform coding of digital data, specifically to real domain processing of transform data. More particularly, this invention relates to reduced-error digital processing of inverse transformed data.
BACKGROUND OF THE INVENTION
Transform coding is the name given to a wide family of techniques for data coding, in which each block of data to be coded is transformed by some mathematical function prior to further processing. A block of data may be a part of a data object being coded, or may be the entire object. The data generally represent some phenomenon, which may be for example a spectral or spectrum analysis, an image, an audio clip, a video clip, etc. The transform function is usually chosen to reflect some quality of the phenomenon being coded; for example, in coding of audio, still images and motion pictures, the Fourier transform or Discrete Cosine Transform (DCT) can be used to analyze the data into frequency terms or coefficients. Given the phenomenon being coded, there is generally a concentration of the information into a few frequency coefficients. Therefore, the transformed data can often be more economically encoded or compressed than the original data. This means that transform coding can be used to compress certain types of data to minimize storage space or transmission time over a communication link.
An example of transform coding in use is found in the Joint Photographic Experts Group (JPEG) international standard for still image compression, as defined by ITU - T Rec. T. 81 (1992) ISO/IEC 10918-1:1994 , Information technology—Digital compression and coding of continuous - tone still images, Part 1 : Requirements and Guidelines . Another example is the Moving Pictures Experts Group (MPEG) international standard for motion picture compression, defined by ISO/IEC 11172:1993 , Information Technology—Coding of moving pictures and associated audio for digital storage media at up to about 1,5 Mbits/s. This MPEG-1 standard defines systems for both video compression (Part 2 of the standard) and audio compression (Part 3). A more recent MPEG video standard (MPEG-2) is defined by ITU-T Rec. H.262 ISO/IEC 13818-2: 1996 Information Technology—Generic Coding of moving pictures and associated audio—Part 2 : video . A newer audio standard is ISO/IEC 13818-3: 1996 Information Technology—Generic Coding of moving pictures and associated audio—Part 3 : audio . All three image international data compression standards use the DCT on 8×8 blocks of samples to achieve image compression. DCT compression of images is used herein to give illustrations of the general concepts put forward below; a complete explanation can be found in Chapter 4 “The Discrete Cosine Transform ( DCT )” in W. B. Pennebaker and J. L. Mitchell, JPEG: Still Image Data Compression Standard , Van Nostrand Reinhold: New York, (1993).
Wavelet coding is another form of transform coding. Special localized basis functions allow wavelet coding to preserve edges and small details. For compression the transformed data is usually quantized. Wavelet coding is used for fingerprint identification by the FBI. Wavelet coding is a subset of the more general subband coding technique. Subband coding uses filter banks to decompose the data into particular bands. Compression is achieved by quantizing the lower frequency bands more finely than the higher frequency bands while sampling the lower frequency bands more coarsely than the higher frequency bands. A summary of wavelet, DCT, and other transform coding is given in Chapter 5 “Compression Algorithms for Diffuse Data” in Roy Hoffman, Data Compression in Digital Systems , Chapman and Hall: New York, (1997).
In any technology and for any phenomenon represented by digital data, the data before a transformation is performed are referred to as being “in the real domain”. After a transformation is performed, the new data are often called “transform data” or “transform coefficients”, and referred to as being “in the transform domain”. The function used to take data from the real domain to the transform domain is called the “forward transform”. The mathematical inverse of the forward transform, which takes data from the transform domain to the real domain, is called the respective “inverse transform”.
In general, the forward transform will produce real-valued data, not necessarily integers. To achieve data compression, the transform coefficients are converted to integers by the process of quantization. Suppose that (λ i ) is a set of real-valued transform coefficients resulting from the forward transform of one unit of data. Note that one unit of data may be a one-dimensional or two-dimensional block of data samples or even the entire data. The “quantization values” (q i ) are parameters to the encoding process. The “quantized transform coefficients” or “transform-coded data” are the sequence of values (a i ) defined by the quantization function Q:
a i = Q ( λ i ) = ⌊ λ i q i + 0.5 ⌋ ( 1 )
where [x] means the greatest integer less than or equal to x. The resulting integers are then passed on for possible further encoding or compression before being stored or transmitted. To decode the data, the quantized coefficients are multiplied by the quantization values to give new “dequantized coefficients” (λ i ′) given by
λ i ′=q i a i . (2)
The process of quantization followed by dequantization (also called inverse quantization) can thus be described as “rounding to the nearest multiple of q i ”. The quantization values are chosen so that the loss of information in the quantization step is within some specified bound. For example, for audio or image data, one quantization level is usually the smallest change in data that can be perceived. It is quantization that allows transform coding to achieve good data compression ratios. A good choice of transform allows quantization values to be chosen which will significantly cut down the amount of data to be encoded. For example, the DCT is chosen for image compression because the frequency components which result produce almost independent responses from the human visual system. This means that the coefficients relating to those components to which the visual system is less sensitive, namely the high-frequency components, may be quantized using large quantization values without perceptible loss of image quality. Coefficients relating to components to which the visual system is more sensitive, namely the low-frequency components, are quantized using smaller quantization values.
The inverse transform also generally produces non-integer data. Usually the decoded data are required to be in integer form. For example, systems for the playback of audio data or the display of image data generally accept input in the form of integers. For this reason, a transform decoder generally includes a step that converts the non-integer data from the inverse transform to integer data, either by truncation or by rounding to the nearest integer. There is also often a limit on the range of the integer data output from the decoding process in order that the data may be stored in a given number of bits. For this reason the decoder also often includes a “clipping” stage that ensures that the output data are in an acceptable range. If the acceptable range is [a,b], then all values less than a are changed to a, and all values greater than b are changed to b.
These rounding and clipping processes are often considered an integral part of the decoder, and it is these which are the cause of inaccuracies in decoded data and in particular when decoded data are re-encoded. For example, the JPEG standard (Part 1) specifies that a source image sample is defined as an integer with precision P bits, with any value in the range 0 to 2**P−1. The decoder is expected to reconstruct the output from the inverse discrete cosine transform (IDCT) to the specified precision. For the baseline JPEG coding P is defined to be 8; for other DCT-based coding P can be 8 or 12. The MPEG-2 video standard states in Annex A (Discrete cosine transform) “The input to the forward transform and the output from the inverse transform is represented with 9 bits.”
For JPEG the compliance test data for the encoder source image test data and the decoder reference test data are 8 bit/sample integers. Even though rounding to integers is typical, some programming languages convert from floating point to integers by truncation. Implementations in software that accept this conversion to integers by truncation introduce larger errors into the real-domain integer output from the inverse transform.
The term “high-precision” is used herein to refer to numerical values which are stored to a precision more accurate than the precision used when storing the values as integers. Examples of high-precision numbers are floating-point or fixed-point representations of numbers.
SUMMARY OF THE INVENTION
In light of the problems described above regarding inaccuracies caused by digital processing techniques and by such things as rounding and clipping after the inverse transform of transform data, one aspect of this invention provides a method for processing transform data in the real domain. This method reduces the undesired errors in the data produced by such things as rounding to integers and clipping to an allowed range after the inverse transform. In an embodiment, this method includes: performing the inverse transform of the transform data such that the real-domain data produced are in the form of high-precision numbers; processing these high-precision numbers; and converting the processed high-precision numbers to integers and clipping to an allowed range only after the processing stage is complete.
It is another aspect of this invention to provide a method for processing transform-coded data in the real domain which reduces the undesired errors in the data produced by the converting to integers and clipping to an allowed range after the inverse transform. In an embodiment, the method includes: performing the inverse quantization of the transform-coded data; performing the inverse transform of the transform data thus produced, such that the real-domain data produced are in the form of high-precision numbers; processing these high-precision numbers; and converting the processed high-precision numbers to integers and clipping to an allowed range only after the processing stage is complete.
Still another aspect of the present invention is to provide a method for processing transform-coded data in the real domain to produce new transform-coded data, which reduces the error produced by converting to integers and clipping to an allowed range after the inverse transform. In an embodiment, this method includes: performing the inverse quantization of the transform-coded data; performing the inverse transform of the transform data thus produced, such that the real-domain data produced are in the form of high-precision numbers; processing these high-precision numbers; performing the forward transform on the processed high-precision numbers; and performing quantization on the new transform data. If the errors in the forward and inverse transforms and in the processing are sufficiently small, there will be no undesirable errors produced in the new quantized transform-domain data.
There is no requirement that the input data to the methods described herein need come from a single data source. Thus, this invention is not restricted to the real-domain processing of data from a single source, but also applies to real-domain processing of data from multiple sources, such as the merging of images or audio data.
The quantization described in the background is the linear quantization used in international image data compression standards such as JPEG and MPEG. There is no requirement that the quantization be linear. Any mapping that reduces the number of transform data levels in a deterministic way can be used with this invention. The quantization step has been described mathematically with a division in Equation (1). Actual embodiments may use a lookup table or a sequence of comparisons to achieve similar results.
It is a further aspect of the invention to provide apparatus, a computer product and an article of manufacture comprising a computer usable medium having computer readable program code means embodied therein for causing a computer to perform the methods of the present invention.
BRIEF DESCRIPTION OF FIGURES
These and other objects, features, and advantages of the present invention will become apparent upon further consideration of the following detailed description of the invention when read in conjunction with the drawing figures, in which:
FIG. 1( a ) is a block diagram showing a method for performing an inverse transform;
FIG. 1( b ) is a block diagram showing a system for performing an inverse transform;
FIG. 2( a ) is a block diagram showing a method for decoding transform-coded data;
FIG. 2( b ) is a block diagram showing a system for decoding transform-coded data;
FIG. 3 is a block diagram showing a method for the real-domain processing of transform data;
FIG. 4 is a block diagram showing a method for performing an inverse transform followed by a forward transform, and demonstrating the multi-generation problem;
FIG. 5 is a block diagram showing a method for decoding and re-encoding transform-coded data, and demonstrating the multi-generation problem;
FIG. 6 is a block diagram showing a method for performing an inverse transform, real-domain data manipulation and a forward transform, and demonstrating the multi-generation problem;
FIG. 7( a ) is a block diagram showing a method for performing real-domain processing of JPEG DCT-coded image data, which exhibits the multi-generation problem;
FIG. 7( b ) is a block diagram showing a system for performing real-domain processing of JPEG DCT-coded image data, which exhibits the multi-generation problem;
FIG. 8( a ) gives the JPEG example luminance quantization matrix;
FIG. 8( b ) gives the JPEG example chrominance quantization matrix;
FIG. 8( c ) is a numerical example of how real-domain rounding can cause significant errors in 8×8 block DCT coded data;
FIG. 8( d ) is a numerical example of how real-domain truncation can cause significant errors in 8×8 block DCT coded data;
FIG. 8( e ) is a series of graphs illustrating how real-domain clipping can cause errors in one-dimensional discrete cosine transform-coded data;
FIG. 8( f ) and FIG. 8( g ) are a numerical example of how real-domain clipping can cause significant errors in 8×8 block DCT coded data;
FIG. 9 is a block diagram showing a method performing multiple iterations of the process described in FIG. 5 , and exhibiting the multi-generation problem;
FIG. 10 is a block diagram showing a method for performing multiple iterations of real-domain manipulations, and exhibiting the multi-generation problem;
FIG. 11( a ) is a block diagram showing an example of a method for reduced-error processing of transform data in accordance with the present invention;
FIG. 11( b ) is a block diagram showing an example of a system for reduced-error processing of transform data in accordance with the present invention;
FIG. 12( a ) is a block diagram showing an example of a method for performing an inverse transform followed by a forward transform, such that this process is lossless in accordance with the present invention;
FIG. 12( b ) is a block diagram showing an example of a system for performing an inverse transform followed by a forward transform, such that this process is lossless in accordance with the present invention;
FIG. 13( a ) is a block diagram showing an example of a method for performing real-domain manipulation of transform data with reduced error followed by a forward transform in accordance with the present invention;
FIG. 13( b ) is a block diagram showing an example of a system for performing real-domain manipulation of transform data with reduced error followed by a forward transform in accordance with the present invention;
FIG. 14( a ) is a block diagram showing an example of a method for reduced-error processing of transform-coded data in accordance with the present invention;
FIG. 14( b ) is a block diagram showing an example of a system for reduced-error processing of transform-coded data in accordance with the present invention;
FIG. 15( a ) is a block diagram showing an example of a method for decoding and re-encoding transform-coded data such that this process is lossless in accordance with the present invention;
FIG. 15( b ) is a block diagram showing an example of a system for decoding and re-encoding transform-coded data such that this process is lossless in accordance with the present invention;
FIG. 16( a ) is a block diagram showing an example of a method for performing real-domain manipulation of transform-coded data with reduced error in accordance with the present invention;
FIG. 16( b ) is a block diagram showing an example of a system for performing real-domain manipulation of transform-coded data with reduced error in accordance with the present invention;
FIG. 17( a ) is a block diagram showing an example embodiment of a method for performing real-domain processing of JPEG-coded image data, such that undesired errors in the new transform-coded data are reduced or eliminated in accordance with the present invention;
FIG. 17( b ) is a block diagram showing an example embodiment of a system for performing real-domain processing of JPEG-coded image data, such that undesired errors in the new transform-coded data are reduced or eliminated in accordance with the present invention;
FIG. 18( a ) is a block diagram showing an example of a method for performing multiple iterations of the real-domain manipulation of transform-coded data with reduced error, where each iteration is as described in FIG. 16( a ) in accordance with the present invention;
FIG. 18( b ) is a block diagram showing an example of a system for performing multiple iterations of the real-domain manipulation of transform-coded data with reduced error, where each iteration is as described in FIG. 16( b ) in accordance with the present invention;
FIG. 19( a ) shows the same 8×8 block numerical starting point of FIG. 8( c ) using the high-precision numbers as input to the forward transform instead of the rounded numbers;
FIG. 19( b ) shows the same 8×8 block numerical starting point of FIG. 8( d ) using the high-precision numbers as input to the forward transform instead of the truncated numbers;
FIG. 19( c ) shows the same 8×8 block numerical steps as FIG. 8( f ); and
FIG. 19( d ) shows the numerical results when the output of the inverse DCT with rounding, but before clipping, is input to the forward transform followed by quantization.
DESCRIPTION OF THE PROBLEM
This invention provides methods, systems, and computer products which reduce or eliminate errors introduced by the processing of digital data. Firstly, the source of the error is analyzed and described. This is followed by a presentation of the invention concepts for error reduction and elimination. It is particularly noted that data manipulation and/or processing as employed here-to-before used digital techniques contaminated by the continued introducing of errors by the respective implementation of digital processing. These techniques employed for years are responsible for an inability to maintain original data precision and the continued deterioration of the data representing the phenomenon as more processing is performed. This is particularly detrimental when a process is performed on data which contain errors imparted on the data by previous processes. This results in the continued impairment of the data which thereby becomes less and less useful as more and more processes are performed thereupon.
The seriousness of the problem as realized by the inventors of the present invention is described forthwith. It is noted that in the figures presented herein, optional steps are often shown with dashed lines and/or boxes.
It is noted that the concepts of the present invention are useful in almost any digital processing technology. However, the subsequent description is mostly related to image data. This is because of the general availability and continued usage of image data compression standards which are employed worldwide. These standards require the introduction into the digital data of the errors to be described and the continued employment and processing of the error contaminated data. These standards basically teach away from the present invention. Thus image technology is a good example for describing the present invention.
FIG. 1( a ) shows an inverse transform method 100 . Transform-domain data ‘A’ 110 are acted on by the inverse transform 120 , which produces high-precision real-valued data 130 . The high-precision data 130 are converted to integers and clipped 140 to produce integer real-domain data 150 . In some cases, the integer-valued data are optionally sent to an output device 160 .
FIG. 1( b ) shows an inverse transform system 105 . Transform-domain data ‘A’ 115 are acted on by the inverse transformer 125 , which produces high-precision real-valued data 135 . The high-precision data 135 are input to the integer converter and clipper 145 to produce integer real-domain data 155 . In some cases, the integer-valued data are optionally input to an output device 165 such as a display monitor, a television set, or an audio player.
FIG. 2( a ) shows a method 200 for decoding transform-coded (i.e. quantized) data. The integer transform-coded data ‘B’ 210 are inverse quantized 220 (i.e. dequantized) with quantization values as in Equation (2) above. The result of the dequantizing step may then be passed as input to the inverse transform 120 , and decoding proceeds as in FIG. 1( a ).
FIG. 2( b ) shows a system 205 for decoding transform-coded (i.e. quantized) data. The integer transform-coded data ‘B’ 215 are input to the inverse quantizer 225 with quantization values as in Equation (2) above. The result of the dequantizing step is passed as input to the inverse transformer 125 , and decoding proceeds as in FIG. 1( b ).
One aspect of the present invention is concerned with the manipulation of both transform data and transform-coded data. The words “manipulation” and “processing” are used interchangeably herein. Manipulation may be employed in order to achieve many different results. For example, image data must often be processed before printing by scaling and/or rotation. Data from two sources can be merged as is performed in chroma-keying of images or mixing of audio data. Manual manipulation of data is often needed for editing or color correction. Such manipulation of transform data are often performed on the integer real-domain data which results from the transform decoding of FIG. 1( a ) and/or FIG. 2( a ).
A process for manipulation of transform data 300 is shown in FIG. 3 . Integer data 150 undergo some form of manipulation 310 . If this manipulation 310 does not produce integer output, the manipulated output 340 is again converted to integers and clipped 320 . The resulting integer data 330 may be stored, transmitted, and/or optionally sent to an output device 160 . Because the stage of clipping and converting to integers 140 is performed before the manipulation which accepts integer input 150 , the resulting errors cause the data output from the manipulation 340 to contain at least small inaccuracies.
It is noted that there is no requirement in the data manipulation processes described above, for the input data to come entirely from one source. For example, many types of data manipulation involve the merging of data from two or more sources. This includes manipulations such as mixing of audio data or merging of images. The processes illustrated in the figures and described generally apply equally well to such types of manipulation. Thus the “input data” used for any of the processes described may in practice come from more than one input source.
It is often the case that data after manipulation are to be re-encoded to the transform domain. It is desirable that the process of decoding and re-encoding, when no manipulation is performed on the real-domain data, should be lossless. That is, the data, when the forward transform operation uses the same transform type operation as the inverse transform type of transform operation, should result in exactly the same transform-domain data as was present initially. However, errors are introduced by the converting to integers and clipping to the allowed range as is illustrated in FIG. 4 . FIG. 4 shows the integer data 150 used as input to the forward transform device 410 , which accepts integer-valued data as input. The resulting transform data ‘A 1 ’ 420 are different from the original transform data ‘A’ 110 which were the input to the inverse transform. This is because the conversion to integers and the clipping process 140 have introduced errors into the process. The problem caused by the changes in data after each iteration, or “generation”, of this process is herein called the “multi-generation problem”.
The multi-generation problem is also illustrated for transform-coded data in FIG. 5 . Here the new transform-domain data 420 are quantized 510 to produce new transform-coded data ‘B 1 ’ 520 . It is important to realize that the quantized data can only change if the errors produced are larger than half a quantization step:
Q (λ i +ε)= Q (λ i ) if |ε|<0.5 q i (3)
where ε is the error produced in this transform coefficient. This is because each of the λ i is already a multiple of the quantization value, since they have been produced by dequantization as in Equation (2). Thus it is advantageous to control the errors so that they are sufficiently small. When the errors are sufficiently small, the new transform-coded data will be exactly the same as the original transform-coded data. The maximum possible error introduced by the conversion to integers by rounding is half the error introduced by truncating during the conversion.
FIG. 6 shows a case wherein image manipulation is performed on the data and the resulting modified data are then re-transformed back to the transform domain. The integer data 150 are manipulated as was shown in FIG. 3 to produce new integer-valued data 610 . These new integer-valued data 610 are used as the input to the forward transform 410 to produce new transform data ‘A 2 ’ 620 . The fact that the process described above without any manipulation produces changes in the transform data 110 shows that when manipulation is performed there are undesired changes in the transform data 110 in addition to those which result from the desired manipulation.
An example of a method which embodies the process shown in FIG. 6 , is shown in FIG. 7( a ). The method 700 illustrated performs real-domain manipulation on coded data such as JPEG-coded image data. The coded data ‘C’ 710 are entropy decoded 720 , which is defined for JPEG-coded data in the JPEG standard. The entropy decode step 720 decompresses the data into quantized DCT coefficients. These quantized coefficients are inverse quantized 730 and passed to the inverse transform, which in this system is the two-dimensional 8×8 inverse DCT 740 . The resulting real-valued image data are rounded to integers and clipped 750 to the allowed range (e.g. [0,255]) to produce integer-valued image data 754 in the allowed range.
If it is necessary to show the data before manipulation, for example when the image manipulation is an interactive process, the image can optionally be sent to a display device 758 . The image is then manipulated 762 to produce some desired change. If the result of the manipulation is non-integer data then the image data may be converted to integers and clipped to the range e.g. [0,255] 768 . In this way the image data 772 may again be displayed 758 . The new real-domain image data 772 are passed to the forward DCT 776 and the resulting DCT coefficients are quantized 780 to produce new quantized DCT coefficients 784 . These coefficients 784 are then entropy encoded 788 to produce new coded data ‘C 1 ’ 792 which are different from the original coded data ‘C’ 710 . Now the new coded data ‘C 1 ’ 792 incorporates not only the desired changes made to the image by the image manipulation 762 , but also the errors resulting from the converting and clipping stages 750 and 768 . It would be advantageous to eliminate or reduce these errors.
An example of a system which embodies the process shown in FIG. 6 , is shown in FIG. 7( b ). The system 705 performs real-domain manipulation on coded data. The coded data ‘C’ 715 are input to the entropy decoder 725 , which is defined for JPEG-coded data in the JPEG standard. The entropy decoder 725 decompresses the data into quantized DCT coefficients. These quantized coefficients are input to the inverse quantizer 735 and the output passed to the inverse transformer, which in this system is the two-dimensional 8×8 inverse DCT-er 745 . The resulting real-valued image data are rounded to integers and clipped 755 (e.g. to the range [0,255]) to produce integer-valued image data 759 in the allowed range.
If it is necessary to show the data before manipulation, for example when the image manipulation is an interactive process, the image can optionally be sent to a display 763 . The image is operated on by a manipulator 767 to produce some desired change. If the result of the manipulation is non-integer data then the image data may be passed to another integer converter and clipper 773 . In this way the image data 777 may again be displayed 763 . The new real-domain image data 777 are passed to the forward DCT-er 781 and the resulting DCT coefficients are input to the quantizer 785 to produce new quantized DCT coefficients 789 . These coefficients 789 are then input to the entropy encoder 793 to produce new coded data ‘C 1 ’ 797 which are different from the original coded data ‘C’ 715 . Now the new coded data ‘C 1 ’ 797 incorporates not only the desired changes made to the image by the image manipulator 767 , but also the errors resulting from the integer converter and clippers 755 and 773 .
FIG. 8( a ) shows the JPEG example luminance quantization matrix 804 for 8×8 DCT luminance blocks. FIG. 8( b ) gives the JPEG example chrominance quantization matrix 814 for 8×8 DCT chrominance blocks. The smallest quantization value in FIG. 8( a ) is 10 . The smallest quantization value in FIG. 8( b ) is 17 . Since the maximum possible error from rounding is 0 . 5 for each of 64 samples, the largest error in the unquantized forward transform coefficients from conversion to integers by rounding is 4 (shown in FIG. 8( c )) for JPEG. For the quantization matrices shown in FIGS. 8( a ) and 8 ( b ) this size error is less than half of all of the values and will disappear during quantization. However, for high quality applications such as high end printing or digital studio editing, the quantization matrix values are much smaller. In some cases, the DC (upper left corner) term is as small as 1 to preserve maximum quality. Then the rounding errors are significant.
The maximum possible error from truncating is just under 1 for each sample. This almost doubles the error in the unquantized forward transform coefficients. For the quantization matrix in FIG. 8( a ) eight quantization values are small enough for this error to potentially change the transform-coded data.
A numerical example showing the multi-generation problem is given in FIG. 8( c ). In this example the transform used is the 8×8 DCT as used in the JPEG still is image compression standard. A set of transform-domain coefficients 822 , of which only one (the constant, or DC, term) is non-zero, are operated on by the inverse transform to produce an block of real-domain data 824 . In this case the data consist of 64 values which are all equal to 128.5. Note that the JPEG level shift of 128 for 8 bit data has been applied. The real-domain data are rounded to the nearest integers 826 , which in this case means that each value is rounded up to 129. The forward transform is then applied to produce new transform-domain coefficients 828 . It can be seen that the resulting new transform coefficients 828 are significantly different from the initial transform coefficients 822 . This is a highly undesirable result.
This example also applies to transform-coded data if the DC quantization value is set to 1, 2, or 4. Then the transform coefficients 822 would be produced from transform-coded values of 4, 2, or 1 respectively. The quantization of the new transform coefficients 828 would change the resulting DC quantization values to 2, 4, or 8 respectively.
Another numerical example showing the multi-generation problem is given in FIG. 8( d ). Again the transform used is the 8×8 DCT as used in the JPEG still image compression standard. A set of transform-domain coefficients 832 , of which only one (the constant, or DC, term) is non-zero, are operated on by the inverse transform to produce a block of real-domain data 834 . In this case the data consist of 64 values which are all equal to 128.875. Note that the JPEG level shift of 128 for 8 bit data has been applied. The real-domain data are truncated to the nearest integers 836 , which in this case means that each value is reduced to 128. The forward transform is then applied to produce new transform-domain coefficients 838 . It can be seen that the resulting new transform coefficients 838 are significantly different from the initial transform coefficients 832 . This is a highly undesirable result.
Having demonstrated the errors caused by real-domain rounding or truncating when converting to integers, we now show how real-domain clipping can cause errors. FIG. 8( e ) shows an example of real-domain clipping 850 . This example uses the one-dimensional DCT to illustrate the problem. FIG. 8( d ) shows a bar chart 854 displaying one block of data consisting of eight samples. The data displayed has only two frequency components: a constant, or DC, component which is indicated by the dotted line; and an alternating, or AC, component which gives an alternating wave pattern symmetrical about the dotted line. The magnitudes of these components, namely the respective DCT coefficients, are high-precision numbers. When quantization is performed, these DCT coefficients are rounded to the nearest quantization level. The data after transform-domain quantization are shown in the bar chart 858 . In the example shown, the DC coefficient has a small quantization value and so quantization does not change the DC level significantly. The AC coefficient shown has a large quantization value and so is changed significantly by quantization. This example shows the AC component almost doubling in magnitude due to quantization. These quantization values reflect, for example, those used when compressing chrominance image data. Thus the data represented after quantization have parts which have negative values. This shows how transform-domain data which, after inverse transforming, give real-domain negative values can be produced by original real-domain data which do not contain negative values.
Bar chart 862 shows the data produced from that in chart 858 after real-domain clipping. Those negative parts of the real data have been changed to 0. This results in the DC coefficient of the data increasing and hence leads to error being introduced. Because the quantization value for the DC coefficient is generally small, the error is large enough to cause a change in the quantized data as given in Equation (3).
To further illustrate the possibility of error introduced by real-domain clipping, a numerical example 870 is shown in FIGS. 8( f ) and 8 ( g ). This example employs the system illustrated in FIG. 5 . This example uses the two-dimensional 8×8 DCT as used for transform coding of images to illustrate the problem described above. The initial quantized DCT coefficients are shown in matrix 874 . All but two of the coefficients are 0; the two non-zero coefficients are the DC coefficient and one high-frequency coefficient. The coefficients, after dequantizing using the quantization matrix shown in FIG. 8( a ), are shown in matrix 878 . When the inverse DCT is performed on these transform data and the level shift of 128 added, real data are produced as shown in matrix 882 . The data shown in matrix 882 have already been rounded to integers but have not been clipped to an allowed range. It can be seen that these real data include several negative values. After clipping, the real data 882 produce clipped real data as shown in matrix 886 . These data are identical to 882 except that each negative value has been replaced by 0. The forward DCT is then applied to the real-domain data to give new rounded transform data 890 . It can be seen that the new transform data are significantly different from the previous transform data 878 . When quantization is performed using the quantization matrix shown in FIG. 8( a ), new transform-coded data 894 are produced. The resulting changes in the transform data are large enough to produce changes in the transform-coded data after quantization. This is a highly undesirable result.
In many situations, the process of decoding, manipulation and re-encoding of data needs to be done multiple times. In these situations each iteration of this process is referred to as a “generation”. The errors described above, caused by converting to integers and clipping to an allowed range in the real domain, accumulate as multiple iterations are performed and may result in significant degradation of the data. It is realized that the foregoing are only representative examples of errors introduced by rounding (or truncating) and/or clipping. Other examples having more or less error developed are possible.
The problem is usually even worse following multiple generations of decoding and re-encoding as shown in FIG. 9 . Initial transform-coded data ‘D 0 ’ 910 is dequantized and inverse transformed 920 , converted to integers and clipped to an allowed range 930 to produce integer-valued real-domain data 940 . The real-domain data 940 are passed to the forward transform and quantized 950 to give new transform-coded data ‘D 1 ’ 960 . This whole process is iterated several times, and after some number ‘n’ of iterations the final transform-coded data ‘Dn’ 970 is produced. Because of errors in each step the final data ‘Dn’ 970 may be very different from the original data.
A case showing the problem significantly worsened due to multiple generations of real-domain manipulation of transform-coded data is shown in FIG. 10 . In addition to the steps shown in FIG. 9 , some form of manipulation 310 is performed on the real-domain data, followed by converting to integers and clipping 320 . After the forward transform and quantization, the resulting quantized transform coefficients 1010 contain some error as in FIG. 5 . After ‘n’ generations, the final transform quantized coefficients 1020 may have quite large undesired errors.
DETAILED DESCRIPTION OF THE INVENTION
An example embodiment of a method for processing transform data with reduced error 1100 is illustrated in FIG. 11( a ). Transform data ‘A’ 110 are passed through an inverse transform 120 to produce high-precision real-domain data 130 , as in FIG. 1( a ). If it is necessary to pass the real-domain data to an output device 160 which takes integer-valued input, or to generate integer-valued data before manipulation for any other reason, the steps of converting to integers and clipping to an allowed range 140 is done before manipulation without affecting the high-precision real-domain data. The desired manipulation 1110 of the real-domain data is performed using a method which accepts high-precision data as input and produces high-precision data 1120 as output. This manipulation method 1110 performs conceptually the same processing on the data as the manipulation on integers 310 described above in FIG. 3 , but operates instead on high-precision data. If it is necessary to pass the manipulated real-domain data to an output device 160 which takes integer-valued input, or to generate integer-valued data after manipulation for any other reason, the steps of converting to integers and clipping to an allowed range 140 are done after manipulation without affecting the high precision of the processed data.
An example embodiment of a system for processing transform data with reduced error 1105 in accordance with the present invention is illustrated in FIG. 11( b ). Transform data ‘A’ 115 are passed through an inverse transformer 125 to produce high-precision real-domain data 135 , as in FIG. 1( b ). If it is necessary to pass the real-domain data to an output device 165 which takes integer-valued input, or to generate integer-valued data before manipulation for any other reason, the integer converter and clipper 145 operates before manipulation without affecting the high-precision real-domain data. The manipulator 1115 operates on the real-domain data accepting high-precision data as input and producing high-precision data 1125 as output. This manipulator 1115 performs conceptually the same processing on the data as the manipulation on integers 310 described above in FIG. 3 , but operates instead on high-precision data. If it is necessary to pass the manipulated real-domain data to an output device 165 which takes integer-valued input, or to generate integer-valued data after manipulation for any other reason, the integer converter and clipper 145 operates after manipulation without affecting the high precision of the processed data.
An example of an embodiment of the present invention employing a method for performing inverse transform followed by forward transform steps 1200 is illustrated in FIG. 12( a ). Transform data ‘A’ 110 are passed through an inverse transform 120 to produce high-precision real-domain data 130 , as in FIG. 1( a ). If it is necessary to pass the real-domain data to an output device 160 which takes integer-valued input, or to generate integer-valued data for any other reason, the steps of converting to integers and clipping to an allowed range 140 are done without affecting the high-precision real-domain data. The high-precision data 130 are used as input to the forward transform 1210 , which accepts real-valued data as input. The resulting transform data ‘A 3 ’ 1220 are identical to the original transform data ‘A’ 110 which were the input to the inverse transform 120 if the forward transform 1210 is the inverse of the inverse transform since the errors from rounding and clipping are not present in the transform data ‘A 3 ’. The forward transform 1210 will produce different transform data ‘A 3 ’ 1220 when a different forward transform is used. This allows conversion between transforms without the errors from rounding and clipping being present in the forward transform input.
An example of an embodiment of the present invention employing a system with an inverse transformer followed by forward transformer 1205 is illustrated in FIG. 12( b ). Transform data ‘A’ 115 are passed through an inverse transformer 125 to produce high-precision real-domain data 135 , as in FIG. 1( b ). If it is necessary to pass the real-domain data to an output device 165 which takes integer-valued input, or to generate integer-valued data for any other reason, the integer converter and clipper 145 operates without affecting the high-precision real-domain data 135 . The high-precision data 135 are used as input to the forward transform 1215 , which accepts real-valued data as input. The resulting transform data ‘A 3 ’ 1225 are identical to the original transform data ‘A’ 115 which were the input to the inverse transformer 125 if the forward transformer 1215 implements the inverse of the inverse transform since the errors from rounding and clipping are not present in the transform data ‘A 3 ’. The forward transformer 1215 will produce different transform data ‘A 3 ’ 1225 when a different forward transformer is used.
FIG. 13( a ) shows a method for performing real-domain manipulation of transform data with reduced error 1300 . This method is formed by extending the method 1100 described in FIG. 11( a ). In this case, the high-precision data 1120 are passed as input to a forward transform 1210 which accepts high-precision data as input, to produce new transform data ‘A 4 ’ 1310 without rounding and/or clipping errors.
FIG. 13( b ) shows a system for performing real-domain manipulation of transform data with reduced error 1305 . This method is formed by extending the system 1105 described in FIG. 11( b ). In this case, the high-precision data 1125 are passed as input to a forward transformer 1215 which accepts high-precision data as input, to produce new transform data ‘A 4 ’ 1315 without rounding and/or clipping errors.
A method for performing real-domain manipulation of transform-coded data with reduced error is illustrated in FIG. 14( a ). FIG. 14( a ) shows integer transform-coded data ‘B’ 210 are dequantized 220 and the output passed through an inverse transform 120 to produce high-precision real-domain data 130 , as in FIG. 2( a ). If it is necessary to pass the real-domain data 130 to an output device 160 which takes integer-valued input, or to generate integer-valued data 150 before manipulation for any other reason, the steps of converting to integers and clipping to an allowed range 140 are done before manipulation without affecting the high-precision real-domain data 130 . The desired manipulation 1110 of the real-domain data is then performed using a method which accepts high-precision data as input and produces high-precision data 1410 as output. This manipulation 1110 performs conceptually the same processing on the data as the manipulation on integers 310 described above in FIG. 3 , but operates instead on high-precision data. If it is necessary to pass the manipulated real-domain data to an output device 160 which takes integer-valued input, or to generate integer-valued data after manipulation for any other reason, the steps of converting to integers and clipping to an allowed range 140 are done after manipulation 1110 without affecting the high precision of the processed data 1410 .
A system for performing real-domain manipulation of transform-coded data with reduced error is illustrated in FIG. 14( b ). FIG. 14( b ) shows integer transform-coded data ‘B’ 215 input to an inverse quantizer 225 and passed through an inverse transformer 125 to produce high-precision real-domain data 135 , as in FIG. 2( b ). If it is necessary to pass the real-domain data 135 to an output device 165 which takes integer-valued input, or to generate integer-valued data 155 before manipulation for any other reason, the integer converter and clipper 145 operates on the data before manipulation without affecting the high-precision real-domain data 135 . The desired manipulation of the real-domain data is then performed using a manipulator 1115 which accepts high-precision data as input and produces high-precision data 1415 as output. This manipulator 1115 performs conceptually the same processing on the data as the manipulation on integers 310 described above in FIG. 3 , but operates instead on high-precision data. If it is necessary to pass the manipulated real-domain data to an output device 165 which takes integer-valued input, or to generate integer-valued data after manipulation for any other reason, the integer converter and clipper 145 operates on the non-integer data 1415 after manipulation 1115 without affecting the high precision of the processed data 1415 .
An example embodiment of a method for real-domain conversion of transform-coded data 1500 is shown in FIG. 15( a ). The high-precision data 130 are used as input to the forward transform 1210 , which accepts real-valued data as input. The output of the forward transform 1210 is quantized 1510 . Depending upon the desired system implementation, the forward transform operation 1210 may employ a different transform than that used in the inverse transform operation 120 . For example, the inverse transform 120 may use the inverse DCT transform whereas the forward transform 1210 may use the Fourier transform. The resulting integer transform-coded data ‘B 2 ’ 1520 are identical to the original integer transform-coded data ‘B’ 210 which were the input to the inverse quantize step 220 if the forward transform operation 1210 is the inverse of the inverse transform operation 120 and the quantization values used in the inverse quantization step 220 and the quantization step 1510 are identical. It is noted that the forward transform 1210 will produce different integer transform-coded data ‘B 2 ’ when a different forward transform is used. Similarly, use of different quantization values in the inverse quantization 220 and quantization 1510 also produces different integer transform-coded data 1520 . This method thus allows conversion between transforms and quantization matrices without the errors from rounding and clipping being present in the forward transform 1210 input 130 .
The conversion between quantization matrices may be for coarser or finer quantization. For converting data from the JPEG international standard to the MPEG international standard, the quantization is likely to be coarser. The higher quality JPEG independent images are needed during the editing process. The coarser, more compressible, MPEG images are used to achieve the desired bandwidth objectives. On the other hand, in recompressing JPEG images after significant hand editing, the quantization is likely to be finer in order to preserve the changes.
An example embodiment of a system for real-domain conversion of transform-coded data 1505 in accordance with the present invention is shown in FIG. 15( b ). The high-precision data 135 are used as input to the forward transformer 1215 , which accepts real-valued data as input. The output of the forward transformer 1215 is input to the quantizer 1515 . Depending upon the desired system implementation, the forward transformer 1215 may produce a different transform than that used in the inverse transformer 125 . For example, the inverse transformer 125 may use the inverse DCT transform whereas the forward transformer 1215 may use the Fourier transform. The resulting integer transform-coded data ‘B 2 ’ 1525 are identical to the original integer transform-coded data ‘B’ 215 which was the input to the inverse quantizer 225 if the forward transformer 1215 produces the inverse of the inverse transformer 125 and the quantization-values used in the inverse quantizer 225 and the quantizer 1515 are identical. It is noted that the forward transformer 1215 will produce different integer transform-coded data ‘B 2 ’ when a different forward transform is produced. Similarly, use of different quantization values in the inverse quantizer 225 and quantizer 1515 also produces different integer transform-coded data 1525 . This system thus allows conversion between transforms and quantization matrices without the errors from rounding and clipping being present in the forward transformer 1215 input 135 .
A method for performing real-domain manipulation of transform-coded data with reduced error 1600 is formed by extending the method 1400 described in FIG. 14( a ) as is illustrated in FIG. 16( a ). The high-precision data 1410 are passed as input to a forward transform 1210 which accepts high-precision data as input. The output values from the forward transform are quantized 1510 to produce new transform-coded data ‘B 3 ’ 1610 .
A system for performing real-domain manipulation of transform-coded data with reduced error 1605 is formed by extending the method 1405 described in FIG. 14( b ) as is illustrated in FIG. 16( b ). The high-precision data 1415 are passed as input to a forward transformer 1215 which accepts high-precision data as input. The output values from the forward transformer are input to the quantizer 1515 to produce new transform-coded data ‘B 3 ’ 1615 .
An example embodiment of a method for real-domain manipulation of transform-coded data with reduced error 1700 is shown in FIG. 17( a ). The chosen embodiment is a method for real-domain manipulation of coded images, which are transform-coded using the DCT. Coded data ‘C’ 710 are decoded by a lossless entropy decode step 720 to produce quantized DCT coefficients. These coefficients are dequantized 730 and passed through an inverse DCT 740 to produce high-precision real-domain data 1710 . If it is necessary to pass the image before manipulation to a display device 758 which takes integer-valued input, or to produce integer-valued data 754 before manipulation for any other reason, the steps of converting to integers and clipping to an allowed range 750 are performed before manipulation 1720 without affecting the high-precision real-domain image data 1710 . The desired manipulation 1720 of the image is then performed using a method which accepts high-precision data as input and produces high-precision data 1730 as output. If it is necessary to pass the manipulated image data to a display 758 which takes integer-valued input, or to generate integer-valued image data 1750 after manipulation for any other reason, the steps of converting to integers and clipping to an allowed range 1740 are performed after manipulation 1720 without affecting the high precision of the processed image data 1730 . The high-precision image data 1730 are passed as input to a forward DCT 1760 which accepts high-precision data as input. The output values from the forward transform 1760 are quantized 780 to produce new integer DCT coefficients 1770 . These coefficients 1770 are encoded by a lossless entropy encode step 788 to produce new coded data ‘C 2 ’ 1780 . If the forward and inverse transforms and the manipulation system are sufficiently accurate so that the error they introduce is less than half a quantization step, as described in Equation (3) given above, no error at all is introduced to the DCT coefficients.
An example invention embodiment of a system for real-domain manipulation of transform-coded data with reduced error 1705 is shown in FIG. 17( b ). The chosen embodiment is to implement a method for real-domain manipulation of coded images such as JPEG-coded images, which are transform-coded using the DCT. Coded data ‘C’ 715 are decoded by a lossless entropy decoder 725 to produce quantized DCT coefficients. These coefficients are sent to a inverse quantizer 735 and then passed through an inverse DCT-er 745 to produce high-precision real-domain data 1715 . If it is necessary to pass the image before manipulation to a display device 763 which takes integer-valued input, or to produce integer-valued data 759 before manipulation for any other reason, the integer converter and clipper 755 produces integer-valued data in the allowed range before manipulation 1725 without affecting the high-precision real-domain image data 1715 . The manipulator 1725 which performs the desired manipulation of the image accepts high-precision data as input and produces high-precision data 1735 as output. If it is necessary to pass the manipulated image data to a display 763 which takes integer-valued input, or to generate integer-valued image data 1755 after manipulation for any other reason, the optional integer converter and clipper 1745 produces integer-valued data 1755 after the operation of the manipulator 1725 without affecting the high precision of the processed image data 1735 . The high-precision image data 1735 are passed as input to a forward DCT-er 1765 which accepts high-precision data as input. The output values from the forward DCT-er 1765 are sent to the quantizer 785 to produce new integer DCT coefficients 1775 . These coefficients 1775 are encoded by a lossless entropy encoder 793 to produce new coded data ‘C 2 ’ 1785 . If the forward and inverse transforms and the manipulation system are sufficiently accurate so that the error they introduce for each coefficient is less than half a quantization step, as described in Equation (3) given above, no additional error is introduced to the DCT coefficients.
A method for performing real-domain manipulations of transform-coded data with reduced error in multiple steps 1800 , alternating the manipulation steps with forward transforming and quantizing steps and inverse transform and quantizing steps, is illustrated in FIG. 18( a ). In general each manipulation may perform another operation on the data. For example for digital studio editing, the first manipulation might color correct the image. The second manipulation might merge the color corrected image with a background using the chroma-keying method. The third manipulation might add highlights to the image. The fourth manipulation might crop the image to convert from the 16:9 width to height aspect ratio of movies to the 4:3 aspect ratio of television. For the printing of images the first manipulation might rotate the image 90 degrees to orient the image with the printing direction. The second manipulation might merge several independent images into one composite image. A third manipulation might do a color conversion.
As shown in FIG. 18( a ) transform-coded data ‘D 0 ’ 910 are dequantized and passed through an inverse transform 920 to produce high-precision real-domain data 1810 . If it is necessary to produce integer-valued data for any reason, the high-precision data 1810 may be converted to integers and clipped to an allowed range 1820 without affecting the high precision of the real-domain data 1810 . The desired manipulation 1110 of the real-domain data is then performed using a method which accepts high-precision data 1810 as input and produces high-precision data 1840 as output. If it is desired to produce an integer-valued of this output data, the high-precision data 1810 may be converted to integers and clipped to an allowed range 1830 without affecting the high precision of the output data. The high-precision output data are passed as input to a forward transformer and quantizer 1850 to produce new transform-coded data ‘F 1 ’ 1860 . The process of inverse quantizing and inverse transforming, manipulation and forward transforming and quantizing may be repeated multiple times with the manipulation 1870 being different upon each iteration. After multiple steps, final transform-coded data ‘Fn’ 1880 are produced with rounding and/or clipping errors reduced or eliminated. Outputs resulting from any of the convert to integer and clip steps may be sent to an output device 1890 with or without a multiplexor.
An example invention embodiment of a system for performing real-domain manipulations of transform-coded data with reduced error in multiple stages 1805 , alternating the operation of a manipulator with the operation of a forward transformer and quantizer and the operation of an inverse quantizer and inverse transformer, is illustrated in FIG. 18( b ). Transform-coded data ‘D 0 ’ 1815 are fed to an inverse quantizer and inverse transformer 1819 to produce high-precision real-domain data 1823 . If it is necessary to produce integer-valued data for any reason, the high-precision data 1823 may be operated on by the integer converter and clipper 1827 without affecting the high precision of the real-domain data 1823 . The manipulator 1115 then operates on the real-domain data 1823 to produce the desired manipulation and produces high-precision data 1845 as output. If it is desired to produce integer-values of this output data, the high-precision data 1845 may be input to an integer converter and clipper 1835 without affecting the high precision of the output data. The high-precision output data are passed as input to a forward transformer and quantizer 1855 to produce new transform-coded data ‘F 1 ’ 1865 . The steps of inverse quantizing and inverse transforming, manipulation and forward transforming and quantizing may be repeated multiple times with the manipulator 1875 being different upon each iteration. After multiple iterations, final transform-coded data ‘Fn’ 1885 are produced with real-domain rounding and/or clipping errors reduced or eliminated. In a particular embodiment the output from any or all of the integer converter and clipper modules is fed to the output device 1895 . For coded image data the output device may be a display or television set. For coded audio data the output device may be a player and/or recorder.
A numerical example showing how the present invention solves one aspect of the multi-generation problem is given in FIG. 19( a ). A set of transform-domain coefficients 822 , of which only one (the constant, or DC, term) is non-zero, are operated on by the inverse transform to produce an block of real-domain data 824 . In this case the data consist of 64 values which are all equal to 128.5. Note that the JPEG level shift of 128 for 8 bit data has been applied. The forward transform is then applied to produce new transform-domain coefficients 1910 . It can be seen that the new transform coefficients 1910 are identical to the initial transform coefficients 822 . This is due to the rounding error not being present in the data sent to the forward DCT.
Another numerical example showing how the present invention solves another aspect of the multi-generation problem is given in FIG. 19( b ). A set of transform-domain coefficients 832 , of which only one (the constant, or DC, term) is non-zero, are operated on by the inverse transform to produce an block of real-domain data 834 . In this case the data consist of 64 values which are all equal to 128.875. Note that the JPEG level shift of 128 for 8 bit data has been applied. The forward transform is then applied to produce new transform-domain coefficients 1938 . It can be seen that the new transform coefficients 1938 are identical to the initial transform coefficients 832 . This is due to the truncation error not being present in the data sent to the forward DCT.
Having demonstrated how using the high-precision numbers removes the errors caused by real-domain rounding or truncating, we now show how real-domain clipping errors are also avoided. The same numerical starting point and first three steps used in FIG. 8( f ) are shown in FIG. 19( c ). The initial quantized DCT coefficients are shown in matrix 874 . All but two of the coefficients are 0; the two non-zero coefficients are the DC coefficient and one high-frequency coefficient. The coefficients after dequantizing are shown in matrix 878 . The quantization matrix used is shown in FIG. 8( a ). When the inverse DCT is performed on these transform data, real data are produced as shown in matrix 882 . The data shown in matrix 882 have already been rounded to integers but have not been clipped to an allowed range.
FIG. 19( d ) shows the results of the forward DCT applied to the real-domain data to give new rounded transform data 1944 . When quantization is performed, new transform-coded data 1948 are produced. In this example, the changes in the transform data are not large enough to produce changes in the transform-coded data after quantization.
Examples of the manipulation between generations include merging two or more transform-coded data sets. For transform-coded image data sets, the merging may be needed because multiple small images need to be collected into one bigger picture. Fan-folded advertising brochures typically are composed of multiple individual pictures. Today's highest end laser printers print more than one page at a time. In such cases, the images generally do not overlap, but may not have the same quantization, positioning relative to the reference grid such as the 8×8 block structure for JPEG DCTs, or orientation. By composing the final picture in the real domain, standard processes can be used for each subimage. Then the composite image can be re-compressed for eventual decompression for on-the-fly printing.
Similarly, digital editing can include many special effects requiring several independent manipulations performed serially. Digital movies often use the fade-in/fade-out special effect to perform a smooth transition between two key scenes. Such special effects may follow independent processing of each scene. Thus, multiple generations of decompression and recompression are often needed in the editing to produce the composite of the special effects.
Chroma-keying involves two independent video data streams. In one video stream the background has been captured. In the other video stream the foreground, often composed of action involving live actors, has been filmed against a blank single color such as a deep blue or black background. Then the blank pixels in the foreground image are replaced with pixels from the background video. Since the pixels are being mixed at a single-pixel level, the images need to be combined in the real domain. The errors introduced by converting to integers and clipping are highly undesirable for such digital studio applications. These errors are reduced or eliminated by implementing the present invention.
Another application example for use of the present invention is in the high-end digital graphics market which uses digital images with sometimes more than 100 megapixels. Glossy advertising brochures and the large photographic trade show booth backdrops are just two examples of the use of such high quality digital imagery. High-quality lossy JPEG compression are sometimes used to keep the transmission and storage costs down. As such images are decompressed and recompressed to allow changes and modifications such as adding highlights, correcting colors, adding or changing text and image cropping, unintentional changes are a problem that is solved with the use of the concepts of the present invention.
The above examples for the concepts of the present invention are usual for image and video transform data. The wide use of the Internet has shown the value of JPEG and MPEG compressed image data. When JPEG images are to be printed, then manipulations such as a change of scale or a change of orientation may be required. In addition, a transformation to another color space followed by recompression will allow the print-ready versions of the image to be stored. Use of the present invention overcomes the problem inherent in propagating the errors from the rounding and clipping.
Audio coded data also needs to be decompressed, mixed with special sound effects, merged with other audio data, edited and processed in the real domain with reduced errors. Similar implementations are performed for other industrial, commercial, and military applications of digital processing employing a transform and an inverse transform of data representing a phenomenon when the data is stored in the transform domain. These are thus other representative applications wherein use of the present invention is highly advantageous.
It is further noted that this invention may also be provided as an apparatus or a computer product. For example, it may be implemented as an article of manufacture comprising a computer usable medium having computer readable program code means embodied therein for causing a computer to perform the methods of the present invention.
It is noted that although the description of the invention is made for particular arrangements of steps, the intent and concept of the present invention are suitable and applicable to other arrangements. It will be clear to those skilled in the art that other modifications to the disclosed embodiments can be effected without departing from the spirit and scope of the invention. | This invention solves problems due to employing error degraded data in digital processing. It particularly solves multi-generation problems wherein transform data degrade during each inverse transform and forward transform cycle even without any processing due to the rounding and clipping errors. It provides methods, systems and devices for reduced-error processing of transform-coded data. After inverse transformation of transform data, high-precision numbers are manipulated. The converting to integers and clipping to an allowed range steps are executed at any stage in the manipulation to obtain integer representation of the inverse transformed data such as for displaying of the data. However, further processing including forward transforming back to the transform domain is executed on the high-precision numbers. Thus, the rounding and clipping errors are not present in the processed data. Although advantageous to many applications employing digital transformed data, the invention is particularly advantageous for use in digital studios during editing of MPEG-coded, JPEG-coded and wavelet-coded video and audio data. | 7 |
RELATED U.S. APPLICATIONS
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STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
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REFERENCE TO MICROFICHE APPENDIX
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FIELD OF THE INVENTION
The invention relates to an electrosurgical instrument comprising two limbs that have an articulated connection and that can be actuated in the manner of a cutting or clamping tool.
BACKGROUND OF THE INVENTION
Electrosurgical instruments have been used for many years in high-frequency surgery especially in order to coagulate biological tissue as well as to cut it. For coagulation a high-frequency current is passed through the tissue to be treated, so that it changes due to protein coagulation and dehydration. The tissue contracts in such a way that the vessels are closed and bleeding is staunched. After coagulation has taken effect the tissue can, for example, be separated by means of a mechanically operating cutting instrument.
Electrosurgical procedures can be carried out in a monopolar as well as a bipolar way. With monopolar technology the electrosurgical instrument has only one current supply and the tissue to be treated (or the patient) must therefore be placed at the other potential. Bipolar instruments which are constructed with two separately isolated sections are gaining more and more in significance, however. The current path between the electrode parts can thus be calculated and does not run long distances through the body of the patient. The effect of, for example, pacemakers or other equipment which are connected to the patient during an operation is thus reduced.
Bipolar coagulation instruments comprise essentially two limbs that have an articulated connection at whose proximal ends handle devices are provided for handling the limbs. At the distal ends of the limbs are electrode parts with coagulation surfaces for gripping the tissue and for passing the coagulation current through the tissue. For this the HF current supplied by a HF generator is fed via current supply devices to the electrode parts of the bipolar instrument.
Known bipolar coagulation instruments often comprise open regions on the electrode parts forming a guide gap for a cutting instrument. This means that the electrode parts are at least partially divided, so that cutting instrument can be placed on the tissue clamped between the electrode parts. The guide gap therefore facilitates access for the cutting instrument to the tissue while being held between the electrode parts of the coagulation instrument. Also, the guide gap is provided to guide the cutting instrument in order to guarantee precise cutting of the tissue. This is advantageous particularly for mechanically operated cutting instruments.
Such an instrument is, for example, known from US 2003/0229344 A1. Bipolar tongs are shown where the effector unit and in particular its electrically conductive areas comprise slits to facilitate access for a cutting instrument to the tissue clamped in the effector unit. The slits are constructed in such a way that the coagulation surfaces of the electrode parts are disrupted as little as possible. With this embodiment of the slits their preparation for reuse, that is to say cleaning, is very time-consuming as the access into the slits is made difficult.
In order to counteract this problem a very wide slit or guide gap is provided in other known instruments. Here a considerable reduction in the coagulation surfaces or insufficient guidance of mechanical cutting instruments in particular has to be accepted.
Known instruments are also provided as disposable instruments in order to save cleaning. This has considerable cost implications.
BRIEF SUMMARY OF THE INVENTION
The object of the invention is to provide an electrosurgical instrument for coagulation of tissue wherein an open region is permanently available on least at one electrode part for optimum guidance of a cutting instrument.
According to the invention there is provided an electrosurgical instrument which includes two limbs that have an articulated connection which can be actuated corresponding to a cutting or a clamping tool. The instrument further includes electrode parts positioned opposite each other with coagulation surfaces at distal ends of the limbs for gripping a vessel or tissue and for passing a coagulation current through the vessel or tissue for its coagulation. At least one electrode part comprises an open region as a guide gap for a cutting instrument, so that at least one electrode part is divided into two areas and the cutting instrument can be applied to the vessel or tissue held in order to carry out a cutting procedure. Moreover, current supply devices are provided for passing the coagulation current from a HF generator to the electrode parts. The at least two areas of the at least one electrode part comprise respective separation surfaces arranged opposite each other and taper in the direction of the coagulation surfaces.
The basis of the invention is that the guide gap expands in the direction which faces away from a cutting area between the electrode parts on both electrode parts. Precise guidance of the cutting instrument is thus possible in direct proximity to the cutting area based on the tapered construction of the guide gap. The coagulation zone of the electrode parts is hardly disrupted. The other areas of the guide gap are at the same time easily accessible and thus easy to clean. If the guide gap has to be re-worked, for example a coating having to be applied, then this can be carried out easily because of the improved access.
In a preferred first embodiment the open regions are provided at the opposite electrode parts wherein these are essentially aligned when the limbs are brought together. If only one open region has been formed at one electrode part this is especially suitable for cutting tissue with, for example, a surgical knife, wherein the tissue rests completely on the opposite electrode part in a tensioned state. If open regions are provided at both electrode parts surgical scissors can, for example, be used on the coagulated tissue and this is easily cut. In order that a well-calculated cut can be carried out the open regions are preferably arranged in the central sections of the electrode parts.
In a further preferred embodiment the cutting instrument is combined with the electrosurgical instrument. The cutting instrument is, for example, situated within one of the limbs and can be brought into a cutting position when required. A change of instruments is thus avoidable, so that the course of an operation does not have to be disrupted.
With the cutting instrument integrated in the coagulation instrument both electrode parts are preferably constructed with the open region, so that the cutting instrument can reach the tissue unhindered.
If the cutting instrument is not constructed so that it is integrated with the electrosurgical instrument, the guide gap has then to be arranged in such a way that a cutting instrument introduced from the outside can be placed with sufficient accuracy at the pretensioned tissue.
One advantageous embodiment provides for the cutting instrument being mechanically and/or electrically operated. A blade constructed on a shaft on the electrosurgical instrument can, for example, be provided which is housed in the limb during coagulation and is applied to the tissue for the cutting procedure. Positioning of the blade or another cutting instrument and also feeding it forward can occur automatically or be carried out by the surgeon mechanically.
A solution according to the invention provides for the cutting instrument being constructed for cutting by means of a HF-current and for being connected to a control unit, so that the cutting current supply depends on the operation phases. The surgeon can control the cutting procedure so that it runs automatically and is optimised.
In a preferred embodiment it is provided that the electrode parts comprise at least one tensioning area each in such a way that when clamping the tissue it is pretensioned between the electrode parts and the cutting procedure can be carried out on the pretensioned tissue by means of the cutting instrument. The tissue under tension is then easier to cut by means of the cutting instrument in particular by means of a mechanical cutting instrument, as tissue fibres are aligned at right angles to the cutting direction and the tissue becomes thinner in the procedure. The force needed to completely cut pretensioned tissue is thus considerably reduced and mechanical stress on the cutting instrument, in particular wear of cutting sections, is counteracted. The cutting procedure itself is also easier for the surgeon and the instrument is easier to handle. As a result of the separation surfaces of the electrode parts tapering towards the cutting area a mechanically operated cutting instrument in particular can be applied easily at the guide gap.
In a preferred embodiment one of the tensioning areas has a convex curvature at least in a first central section while the tensioning area positioned opposite has a concave curvature at least have essentially a positive fit. As a result of the curved tensioning areas tensioning of the tissue is facilitated in the simplest way because it is pulled, that is to say stretched, by the curved areas on both sides in the direction of their end areas. Because of the tight fit the tissue tensioned between the limbs is securely held in a tensioned state.
The terms “convex” and “concave” in this context are not just to be understood as meaning a rounded arc. Rather, these terms both here and in the claims are intended to cover not only a surface which defines a rounded arc but also any kind of elevation or recess, hence also a roof-like elevation and thus a V-shaped recess.
In a further preferred embodiment one of the tensioning areas has a convex curvature at least in a first central section while the tensioning area positioned opposite has a concave curvature at least in the second central section. A radius of curvature of the concave tensioning area at least in the second central section is greater than a radius of curvature of the convex tensioning area in the first central section. The curvatures run along the longitudinal axes of the distal ends in such a way that the vessel or tissue that is held between the distal ends and extends perpendicularly to the longitudinal axes is held with a pressure that increases towards the first and second central sections. Based on the different curvatures of the coagulation surfaces contact between the coagulation surfaces can, seen mathematically, only occur at their crests. This means that an area of maximal proximity is formed between the coagulation surfaces that extends symmetrically around the crests of the coagulation surfaces. In this area tissue is particularly strongly pressed together as a result of the limbs being brought together due to the increased pressure compared to the other coagulation areas and is thus safely held between the electrode parts.
It is advantageous that the smooth geometry is easy to produce, inhibits adherence of tissue during the procedure and the coagulation surfaces can be easily prepared for reuse and if required reconditioned. In addition secure closure of a vessel or tissue is achieved as a result of the high clamping force in the area of high pressure.
In one of the solutions according to the invention it is provided that at one tensioning area and/or on the opposite tensioning area a surface profile is formed which supports the tensioning effect. The profile is preferably formed at the end areas of the respective tensionings and moves the tissue additionally in a direction of pull defined by the tensioning areas or prevents a backward movement of the tissue against this direction of pull.
The surface profile supporting the tensioning effect is preferably constructed as a saw tooth profile. The teeth of the profile can, for example, be arranged in such a way that during the bringing together of the limbs they increasingly grip the tissue and transport it in the direction of pull. This increases the tension in the tissue considerably. Care must, however, be taken that injury to the tissue caused by the profile is avoided, so that the teeth are preferably constructed as rounded-off nodules.
The profile is preferably constructed in such a way that the tissue is held by the profile in its tensioned position when the limbs are slightly opened. The profile acts therefore as an arrangement of barbs.
In a preferred embodiment the surface profile supporting the tensioning effect is constructed in such a way that at least one constriction is provided between the electrode parts. This is particularly efficient with electrode parts which have the same radii of curvature. This means that the coagulation surfaces of the electrode parts, constructed in particular with the same radius of curvature, are preferably constructed at both end areas in such a way that while bringing the limbs together the tissue is transported in the direction of the end areas and is clamped in a respective constriction opposite the remaining area when the limbs have been brought together. This constriction has the additional advantage that the coagulation surfaces can essentially have a smooth construction and are thus easy to clean. Injury to the tissue is also avoided on account of the smooth surface.
In an advantageous embodiment an insulating section is formed on at least one of the coagulation surfaces, so that direct electrical contact between the coagulation surfaces can be prevented. Due to the heat conducting properties of the insulating section coagulation of the tissue is also guaranteed at this section. The insulating section depending on the construction of the electrode parts is to be provided at the areas of at least one coagulation surface which are closest to the opposite coagulation surface. This has to be taken into consideration in particular when the tensioning areas and thus the coagulation surfaces have a different radius of curvature. The insulating section is then preferably arranged at the central section of the tensioning area or tensioning areas, thus preventing a short circuit between the electrode parts. The tensioning effect is further enhanced simultaneously by the insulating section.
If the insulating section is constructed at the areas of at least one coagulation surface in closest proximity to the opposite coagulation surface it can close flush with the respective coagulation surface. The surface part of the coagulation surface which describes the area in closest proximity to the opposite coagulation surface must then be constructed from continuous insulating material, so that contact between the conductive areas of the coagulation surfaces is prevented. With convex or concave tensioning areas positioned opposite or coagulation surfaces having different radii of curvature the insulating section would have to be arranged along one crest of at least one coagulation surface. It is advantageous that the insulating section in this embodiment is protected by being housed in the respective electrode part and is thus safe from wear.
Alternatively, it is possible to construct the insulating surface in such a way that it protrudes from the respective coagulation surface. In this case the insulating section does not just serve the purpose of insulating, but also to bend the tissue to be treated several times in order to achieve better holding of the tissue between the distal ends of the electrosurgical instrument.
In a preferred embodiment the insulating section, that is to say the insulating section protruding from the respective coagulation surface, is constructed from several part sections. This facilitates an especially secure hold of the tissue between the electrode parts because the tissue is bent several times at the edges of the insulating section.
One solution according to the invention provides for constructing the insulating section itself to be structured in order to achieve an optimal hold of the tissue.
A preferred embodiment provides for the insulating section being constructed from ceramic or diamond. Advantageously both ceramic and diamond comprise amongst other things a high corrosion resistance and high wear resistance to mechanical stress.
In a further preferred embodiment the insulating section is formed as the particular or each surface profile supporting the particular or each tensioning effect. A short circuit is thus prevented from occurring between the electrode parts in the simplest way as well as the tensioning of the tissue being increased.
A device preventing a short circuit between the electrode parts can, for example, also be provided at the limbs. If, for example, a spacer has been arranged thereon, the limbs cannot be brought together completely and a gap remains between the electrode parts.
Electrosurgical instruments of this kind can, for example, be constructed for use on an open body cavity. The principle of the electrode parts having a tensioning area can, however, also be employed for instruments used in endoscopies. The electrode parts attached to the limbs and if required the cutting instrument are then, for example, operated via a handle attached to a shaft or a control unit is provided, so that actuation of the electrode parts and/or the cutting instrument is controlled by the same. The electrosurgical instrument is thus preferably constructed as a laparoscopic instrument.
Embodiment of the invention will now be described by way of example with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic cross-sectional view from the front of an electrode arrangement a first embodiment of electrosurgical instrument;
FIG. 2 is a perspective view of second embodiment of electrosurgical instrument;
FIG. 3 is a schematic cross-sectional view from the front of the electrode arrangement of the second embodiment shown in FIG. 2 ;
FIG. 4 is a schematic cross-sectional view from the front of a third embodiment of electrode arrangement; and
FIG. 5 is a schematic cross-sectional view from the front of a fourth embodiment of the electrode arrangement.
DETAILED DESCRIPTION OF THE INVENTION
The same reference numerals will be used in the following description for the same parts and parts with the same function.
FIG. 1 shows a schematic front view section of the enlarged electrode layout according to a first preferred embodiment. The electrode layout is, for example, provided on an electrosurgical instrument, as described in more detail in FIG. 2 . The electrode parts 22 , 23 comprise open regions 22 d , 23 d which form a guide gap 24 for a cutting instrument 30 . Due to the open regions 22 d , 23 d the electrode parts 22 , 23 comprise two respective areas. The cutting instrument 30 can therefore be placed on the clamped tissue 40 for carrying out a cutting procedure. The guide gap 24 also facilitates a precise cut of the tissue 40 , because the cutting instrument 30 can be guided along the guide gap 24 . This is advantageous when the cutting instrument 30 is operated mechanically. As can be seen from the diagram the open regions 22 d , 23 d are aligned so as not to impede the cutting procedure. At least two areas of the respective electrode parts 22 , 23 comprise respective separation surfaces 22 e , 22 e ′, 23 e , 23 e ′ opposite each other tapering in the direction of the coagulation surfaces 22 a , 23 a . The guide gap 24 thus expands in the direction facing away from a cutting area 25 between the electrode parts 22 , 23 at each electrode part 22 , 23 .
Based on the tapered construction of the guide gap 24 precise guidance of the cutting instrument 30 is possible in the direct proximity of the cutting area 25 and a coagulation zone of the electrode parts 22 , 23 is hardly disrupted. At the same time other areas of the guide gap 24 are easily accessible and thus also easy to clean. If the guide gap 24 has to be re-worked, for example, a coating has to be applied, this can then be carried out easily because of the improved access.
FIG. 2 shows a perspective drawing of an electrosurgical instrument with an electrode layout according to the invention in a second preferred embodiment. FIG. 3 shows the schematic front view section of the electrode layout according to the second preferred embodiment from FIG. 2 . The instrument 10 is constructed for procedures on the open body cavity. Two limbs of the electrosurgical instrument 10 are identified in the figure by reference numbers 15 and 16 . The two limbs 15 , 16 are connected to each other via a spindle 17 and can swivel around the same. They comprise electrode parts 22 , 23 fitted with distal ends 11 , 12 wherein the electrode parts 22 , 23 are positioned opposite each other. A vessel or tissue 40 can, for example, be gripped, and be coagulated by means of a HF current being passed through it, with the aid of the electrode parts 22 , 23 which comprise coagulation surfaces 22 a , 23 a . Moreover, handles 18 , 19 are provided which connect to the respective proximal ends 13 , 14 of the limbs 15 , 16 . The proximal ends 13 , 14 of the limbs 15 , 16 each end in a current connection element or a current supply device 20 , 21 for the connection of the electrosurgical instrument 10 to a HF generator (not depicted) which generates HF voltage, so that the HF current can, for example, be passed through the electric cables (not shown) running through the instrument 10 to the electrode parts 22 , 23 .
The electrode layout corresponds largely to that described in FIG. 1 . The electrode parts 22 , 23 comprise also in this embodiment two respective areas where respective separation surfaces 22 e , 22 e ′, 23 e , 23 e ′ positioned opposite each other tapering in the direction of the coagulation surface are provided. The guide gap 24 thus expands here also in the direction facing away from cutting area 25 between the electrode parts 22 , 23 at each electrode part 22 , 23 . Due to the guide gap 24 the tissue 40 can be cut by means of a cutting instrument 30 , while still being held by the electrode parts 22 , 23 .
The electrode parts 22 , 23 are, however, constructed in such a way that one electrode part 23 covers the other electrode part 22 when the limbs 15 , 16 are bought together. As can be seen from the figure the electrode parts 22 , 23 comprise a curvature. One electrode part 22 has a convex curvature 22 b and electrode part 23 positioned opposite the concave electrode part has a concave curvature 23 b . The electrode parts 22 thus fit essentially positively together when the limbs 15 , 16 are brought together. As a result of the curved electrode parts 22 , 23 the tissue 40 is pulled in the direction of the end areas of electrode parts 22 , 23 , that is to say it is stretched in a direction of pull Z. The electrode parts 22 , 23 thus form tensioning areas 22 c , 23 c . The tissue 40 is then easier to cut, as tissue fibres are aligned at right angles to a cutting direction and the tissue 40 becomes thinner in the procedure. Because of the tight fit the tissue 40 is fixed in a tensioned state between the limbs 15 , 16 . The electrode parts 22 , 23 in this embodiment are essentially formed completely as tensioning areas 22 c , 23 c . Alternatively, it is possible that only sections of the electrode parts form tensioning areas.
The cutting instrument 30 comprises a blade 31 on a shaft and is housed during a coagulation phase within the limb 15 . For the cutting procedure the cutting instrument 30 can be positioned on the already coagulated tissue and for cutting tissues 40 it can be moved at a defined feed rate. This occurs in this embodiment, for example, by means of a control unit (not shown) which controls the cutting instrument 30 and is activated by a finger switch 32 . As the cutting instrument 30 is integrated in the electrosurgical instrument 10 a change of instruments and thus disruption of an operation procedure is avoidable.
Alternatively, it possible for the user to actuate the cutting instrument 30 mechanically. The surgeon can then push the blade 31 when required through the limb 15 to and through the tissue. If no device for cutting the tissue is provided on the electrosurgical instrument the guide gap has then to be constructed in such a way that a cutting instrument being introduced from the outside, for example surgical scissors, can be placed with sufficient accuracy on the pretensioned tissue.
For a practical application a spacer (not shown) or similar device maintaining a gap between the electrode parts 22 , 23 is constructed on the electrosurgical instrument 10 , so that direct contact, and thus a short circuit, between the coagulation surfaces 22 a , 23 a of the electrode parts 22 , 23 can be prevented. The spacer can, for example, be formed at one of the limbs 15 , 16 .
Alternatively, it is possible to construct the spacer as an insulating section on the electrode parts. Due to the heat conducting properties of the insulating section coagulation is also guaranteed at the same.
The electrosurgical instrument 10 shown in FIG. 2 , as already mentioned, is constructed for use on the opened body cavity. The principle of the electrode parts having tapering separation surfaces can also be employed in endoscopy. The electrode parts attached to the limbs, and if required the cutting instrument, are then, for example, operated via a handle attached to a shaft or a control unit is provided so that actuation of the electrode parts and/or the cutting instrument is controlled by it.
FIGS. 4 and 5 respectively show an enlarged front view section of an electrode layout in a third and fourth embodiment. The electrode parts 22 , 23 correspond essentially to the embodiment of that shown in FIGS. 2 and 3 . Moreover electrode parts 22 , 23 comprise also two respective areas, where separation surfaces 22 e , 22 e ′, 23 e , 23 e ′ arranged opposite each other tapering in the direction of the coagulation surface 22 a , 23 a are provided. The guide gap 24 thus also expands here in the direction facing away from a cutting area 25 between the electrode parts 22 , 23 at each electrode part 22 , 23 .
In this embodiment the electrode part 22 has a convex curvature in a first central section while the electrode part 23 positioned opposite has a concave curvature in a second central section. A radius of curvature of the concave coagulation surface 23 a is greater than a radius of curvature of the convex coagulation surface 22 a . The curvatures 22 b , 23 b run along longitudinal axes of the distal ends 11 , 12 in such a way that a vessel or tissue 40 that is held between the distal ends 11 , 12 and extends perpendicularly to the longitudinal axes is held with a pressure that increases towards the first and second central sections. Due to the curvatures 22 b , 23 b the electrode parts 22 , 23 in these embodiments are also formed as tensioning areas 22 c , 23 c . As a result of the tensioning areas 22 c , 23 c the tissue 40 is stretched in a direction of pull Z towards the end regions of the electrode parts 22 , 23 . The fibres of the tissue 40 are thus aligned at right angles to a cutting direction, so that the tissue 40 is easier to cut.
FIG. 5 differs essentially from the electrode layout shown in FIG. 4 only in that a protruding insulating section 28 , formed from two part sections 28 a , 28 a ′, is provided directly adjacent to an open region 22 d at the convex electrode part 22 which is divided by the open region 22 d into two areas. The part sections 28 a , 28 a ′ of the insulating section 28 extend preferably parallel to a crest of the electrode part 22 . Thus a short circuit between the electrode parts 22 , 23 is prevented when they are brought together. The part sections 28 a , 28 a ′ of the insulating section 28 support the tensioning effect of the tensioning area 22 on the one hand and facilitate bending of the clamped tissue 40 on the other. A reliable hold of the same between the electrode parts 22 , 23 is thus ensured.
Alternatively, it would be possible to construct the insulating section at the coagulation surface 22 a in such a way that it also extends continuously along the crest of the coagulation surface 22 a , but is essentially flush with it. The insulating section is then fitted into the coagulation surface 22 a . This is possible because the insulating section would be provided at the first central section of the coagulation surface 22 a and would thus reach the opposite coagulation surface 23 a first and exclusively when the limbs 15 , 16 are brought together. It would be advantageous if the insulating section in this embodiment is protected by being housed in the respective electrode part 22 and is thus safe from wear.
The insulating section 28 is preferably constructed from ceramic or diamond. Both materials show amongst other things a high corrosion resistance and high wear resistance to mechanical stress.
The electrode part 23 having a concave curvature 23 b comprises a saw tooth profile 27 , 27 ′ at the end areas. The teeth can, for example, be arranged in such a way that during the bringing together of the limbs they continue to grip the tissue 40 and transport it in the direction of pull Z. This increases the tension in the tissue 40 considerably. Care must, however, be taken that injury to the tissue 40 caused by the profile is avoided, so the teeth are preferably constructed as nodules.
The nodules are preferably laid out in such a way that the tissue 40 is held by the profile 27 , 27 ′ in its tensioned position when the limbs are opened slightly. The profile 27 , 27 ′ acts therefore as an arrangement of barbs.
Alternatively or in addition it would be possible to construct the surface profile supporting the tensioning effect in such a way that in particular between the electrode parts having the same radius of curvature at least one constriction is provided. This means that the coagulation surfaces of the electrode parts are preferably constructed at both end areas in such a way that the tissue during the bringing together of the limbs is transported in the direction of the end areas and is clamped in a constriction opposite the remaining area when the limbs have been bought together. This constriction has the additional advantage that the coagulation surfaces can essentially have a smooth design and are thus easy to clean. Because of the smooth surface injury to the tissue is also avoided.
An insulating section arranged between the electrode surfaces can advantageously be constructed as a surface profile supporting a tensioning effect of the tensioning areas. A short circuit is thus prevented from occurring between the electrode parts in the simplest way as well as the tensioning of the tissue being increased.
LIST OF REFERENCE NUMERALS
10 Electrosurgical instrument
11 Distal end
12 Distal end
13 Proximal end
14 Proximal end
15 Limb
16 Limb
17 Spindle
18 Handle
19 Handle
20 Current connection element, current supply device
21 Current connection element, current supply device
22 Electrode part
22 a Coagulation surface
22 b Convex curvature
22 c Tensioning area
22 d Open region
22 e , 22 e ′ Separation surface
23 Electrode part
23 a Coagulation surface
23 b Concave curvature
23 c Tensioning area
23 d Open region
23 e , 23 e ′ Separation surface
24 Guide gap
25 Cutting area
27 , 27 ′ Profile
28 Insulating section
28 a , 28 a ′ Part section of the insulating section
30 Cutting instrument
31 Blade
32 Finger switch
40 Tissue, vessel
Z Direction of pull | The invention relates to an electrosurgical instrument comprising two limbs that have an articulated connection and that can be actuated in the manner of a cutting or a clamping tool. The instrument also comprises opposing electrode parts with coagulation surfaces on distal ends of its limbs for holding a vessel or tissue and for passing a current through said vessel or tissue to cause it to coagulate. At least one electrode part has an open region that acts as a guide gap for a cutting instrument, so that the electrode part(s) is/are divided into at least two areas and the cutting instrument can be applied to the clamped vessel or tissue to execute a cutting operation. In addition, current supply devices supply the coagulation current from a high-frequency generator to the electrode parts. The improved configuration of said electrosurgical instrument allows the open region on the electrode part(s) to afford optimal guidance of a cutting instrument, whereby said open region can be easily prepared for additional cutting operations and/ or be subjected to an after-treatment. To achieve this, the two or more open regions of the electrode part(s) comprise respective opposing separation surfaces that taper in the direction of the coagulation surfaces. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Not Applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable.
REFERENCE TO MICROFICHE APPENDIX
[0003] Not Applicable.
BACKGROUND OF THE INVENTION
[0004] The invention relates to portable adhesive tape dispensers that function as tape protectors, specifically dispensers/protectors that have the ability to be easily carried and readily dispense and sever lengths of tape as needed and to protect the tape roll's freshly y exposed tape end.
[0005] Adhesive tape such as electrical friction, masking, scotch type and other tapes such as electrical wire marking and security tape are widely used in numerous facets of todays society.
[0006] Originally these tapes were and many are still used without the aid of a dispensing system. In addition, with the exception of medical tapes most tapes lack protective devices and are subject to abrasions and contaminants that can render an entire roll of tape unfit for use. In some cases such as with electrical tape and electrical wire marking tapes abrasions and contaminants can lead to catastrophic failure of the bonding adhesive which can further lead to unintended electrical short circuits and electrical ground faults, thus causing fire, loss of property and life.
[0007] As an improvement inventors have created numerous portable tape dispensers which aid the user in extracting and severing a length of tape. Furthermore, U.S. Pat. No. 4,880,152 to Trankle and U.S. Pat. No. 5,961,066 to Hambleton detail wrist held portable tape dispensers which allow the user to extract and separate a length of tape with one hand while holding an object in the other, possibly to be taped.
[0008] U.S. Pat. No. D 369,385 to Lapointe, U.S. Pat. No. D 428,922 to Packard et al. and U.S. Pat. NO. D 448,416 to Kimura claim tape dispensers that are mostly enclosed providing a good amount of protection to the tape roll.
[0009] U.S. Pat. No. 4,735,351 to Biswas and U.S. Pat. No. 4,252,258 to Plummer detail inventions capable of holding, dispensing, cutting off and holding a tape roll's tape end ready for the next use. These inventions are also capable of being carried and both are intended to make available multiple tape rolls for use.
[0010] From the body of prior art it is obvious that the inventions designed as wearable tape dispensers do not completely protect the tape products from foreign contaminants and/or abrasions. And those inventions which do completely protect the tape products are not specifically intended to be wearable.
BRIEF SUMMARY OF THE INVENTION
[0011] The present invention comprises a device designed for and having the capability to be loaded with one or more rolls of tape which can be easily carried and that can readily dispense and sever lengths of tape as needed.
[0012] The present invention is new and solves a real world need because the above common features are combined with a closure which completely shields the tape product(s), including the tape end(s) from foreign contaminants. In addition the present invention accomplishes these goals without the complicated components found in many of the prior art devices.
OBJECTS AND ADVANTAGES
[0013] Accordingly, the objects and advantages of my above titled patent are;
[0014] (a) to provide a tape housing which prevents foreign objects from contaminating housed material(s),
[0015] (b) to provide a tape housing which prevents foreign objects from cutting or abrading a tape roll,
[0016] (c) to provide a tape housing which allows easy access to a tape roll's tape end(s),
[0017] (d) to provide a tape housing which facilitates the clean and easy separation of a length of tape from a tape roll, or a plurality of tape rolls, and
[0018] (e) to provide a tape housing which is easy to store and carry.
[0019] Further objects and advantages are to provide a tape housing that ensures at least one housed tape roll will be maintained and dispensed in a manner most advantageous to the tape product's protection thus reducing the possibility of electrical and/or other hazards due to impaired or damaged tape products.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0020] [0020]FIG. 1 is a right side view of the main housing.
[0021] [0021]FIG. 2 is a front view of the main housing.
[0022] [0022]FIG. 3 is a back view of the main housing.
[0023] [0023]FIG. 4 is a perspective view of the main housing.
[0024] [0024]FIG. 5 is a perspective view of the tape roll bearing race.
[0025] [0025]FIG. 6 is a side view of the tape roll bearing race.
[0026] [0026]FIG. 7 is an end view of the tape roll bearing race.
[0027] [0027]FIG. 8 is a perspective view of the cutoff snap-cap.
[0028] [0028]FIG. 9 is a left end view of the cutoff snap-cap.
[0029] [0029]FIG. 10 is a right end view of the cutoff snap-cap.
[0030] [0030]FIG. 11 is a right side view of the front cover cover plate.
[0031] [0031]FIG. 12 is a front view of the front cover cover plate.
[0032] [0032]FIG. 13 is a back view of the front cover cover plate.
[0033] [0033]FIG. 14 is a perspective view of the lock screw.
[0034] [0034]FIG. 15 is a side view of the lock screw.
[0035] [0035]FIG. 16 is an exploded perspective view of a tape roll's positioning on the tape roll bearing race and their fitment into the main housing.
[0036] [0036]FIG. 17 is a perspective view of the main housing and tape roll bearing race with a roll of tape installed.
[0037] [0037]FIG. 18 is an exploded view of the cutoff snap-cap, front cover cover plate and lockscrew fitment.
[0038] FIGS. 19 - 24 are frontal views which detail the use of the invention.
[0039] [0039]FIG. 19 shows cutoff snap-cap being opened.
[0040] [0040]FIG. 20 shows a tape roll's tape end being grasped.
[0041] [0041]FIG. 21 shows a length of tape being extracted.
[0042] [0042]FIG. 22 shows the tape being secured on the tape holding area.
[0043] [0043]FIG. 23 shows the cutoff snap-cap closed causing tape length separation.
[0044] [0044]FIG. 24 shows tape length separation.
DETAILED DESCRIPTION OF THE INVENTION
[0045] A preferred embodiment of the present invention and its use is illustrated in FIGS. 1 - 24 .
[0046] Referring more particularly to FIGS. 1 - 4 , the preferred embodiment has a main housing 30 that is comprised of a back area 31 and a raised edge having a top 32 , a left side 33 , a right side 34 , and a bottom 35 . This single piece of injection molded, machined or otherwise constructed material has a carrying clip or other carrying means 36 attached on the outer side of the upper back (FIGS. 1 and 3) and a cylindrical shaft bearing piece 37 protrudes forward from the inner back wall of said main housing (FIGS. 1, 2 and 4 ). The shaft bearing peace has a threaded recess 38 in the center of the front facing end (FIGS. 1, 2, and 4 ).
[0047] The bottom edge of the main housing 35 contains a tape cutoff slot 39 , two tape pull recesses 40 , a tape end holding area 41 , a tape transfer slot 42 and a cylindrical cutoff snap-cap swivel bearing cavity 43 that is open at the main housing's front and partially open on the right and bottom edge corner (FIGS. 2 and 4). On the front face of the raised edges are front cover cover plate alignment pins 44 , and on the lower back and lower front area of the front cover cover plate 58 there is a set of cutoff snap-cap closure indentures 45 .
[0048] Referring now more particularly to FIGS. 5 - 7 , integral to the present embodiment is a cylindrical tape roll bearing race 46 having an inner bore 47 slightly larger than the main housing's shaft bearing piece's 37 outer diameter. The back side of the tape roll bearing race has a raised tape roll flange 48 that extends to an outer diameter that is larger than the intended tape product's inner diameter 49 . In addition the main area of the tape bearing race's outer diameter 50 is of a size to firmly hold the intended tape product's inner diameter 49 .
[0049] Referring now to FIGS. 8 - 10 , integral to the present embodiment is a tape end protector cutoff snap-cap 51 here after referred to as the cutoff snap-cap which has a swivel bearing end 52 that is slightly smaller in circumference than the main housing's swivel bearing cavity 43 . Attached to this is a cover piece 53 having a length and width to cover the bottom edge of the main housing and possessing raised edges 54 that cover a portion of the main housing's lower back and the front cover cover plate's lower area (FIG. 19). On the interior facing raised edges of the cutoff snap-cap there are a set of cutoff snap-cap closure nodes 55 oriented to align with the cutoff snap-cap closure indentures 45 and on the exterior of the cutoff snap-cap's raised edges are gripping aids 56 . Opposite the swivel bearing end of the cutoff snap-cap is a tape cutoff extrusion 57 having a sufficiently angled edge to cleanly sever the intended tape product.
[0050] Referring now to FIGS. 11 - 13 and also integral to the present embodiment is a front cover cover plate 58 . The back or inner facing side of the front cover cover plate 59 has alignment pin holes 60 that correspond to the main housings alignment pins 44 and a centrally located circular tape bearing race spacer extrusion 61 protrudes inward having an inner diameter slightly larger than the cylindrical shaft bearing piece 37 , and an outside diameter similar to the outside diameter of the tape bearing race's raised tape roll flange 48 . The front side of the front cover cover plate 62 has a centrally located recessed circular indenture 63 and centered in this is a lock screw hole 64 having a diameter slightly larger than the cylindrical shaft bearing's threaded recess 38 .
[0051] Referring now to FIGS. 14 and 15, and also integral to the present embodiment is an assembly lock screw 65 hereafter referred to as a lock screw which has a threaded end 66 which corresponds to the cylindrical shaft bearing's threaded recess 38 . Adjoining the threaded end is an unthreaded length 67 having a diameter slightly smaller than the front cover cover plate's lock screw hole 64 and a length equal to the thickness of the front cover cover plate minus the thickness of the centrally located circular indenture 63 . This unthreaded length further adjoins the lock screw's cap 68 which has a diameter slightly less and a thickness slightly thinner than the front cover cover plate's centrally located circular indenture 63 . The lock screw's cap also has a slotted indenture 69 traversing the frontal face.
USE OF INVENTION
[0052] The manner of using the claimed invention's preferred embodiment may first entail the loading of tape into the invention.
[0053] Referring now to FIG. 16, load an appropriate roll of tape onto the tape roll bearing race 46 ensuring that the tape roll is oriented to unroll in a clockwise direction relative to the invention. Insert the frontal end of the tape roll bearing race 46 through the back of the tape roll's center 49 until the tape roll is seated firmly against the tape roll bearing race flange 48 .
[0054] Referring now to FIG. 17, free approximately four or five inches of tape from the tape roll and install tape 49 and tape roll bearing race 46 onto the tape roll bearing shaft ensuring that the free tape end is passed through the main housing's tape transfer area 42 . Said free 4 or 5 inches of tape should then be adhered to the tape end holding area 41 .
[0055] Referring now to FIG. 18, the front cover cover plate 58 should be installed ensuring that the front cover cover plate alignment pins 44 are properly aligned with their corresponding front cover cover plate alignment pin holes 60 . With the front cover cover plate 58 seated, install the lock screw 65 by inserting the lock screw into centrally located lock screw hole 64 in front cover cover plate 58 where it engages the shaft bearing's threaded recess 38 and rotate lock screw in a clockwise direction utilizing a screw driver or other means until lock screw is firmly seated.
[0056] Referring now to FIGS. 23 and 24, once invention is assembled operator should close cutoff snap-cap 51 and remove excess tape end that may protrude from cutoff snap-cap.
[0057] With the invention loaded with tape product it can be used as follows:
[0058] Referring now to FIGS. 2, 3 and 19 - 24 ,
[0059] 1. Carry invention utilizing one or more carrying means 36 (FIGS. 1 and 3).
[0060] 2. Open tape end protector cutoff snap-cap 51 and swivel open utilizing the snap-cap gripping aides 56 (FIG. 19).
[0061] 3. Insert a finger and or thumb into one or both tape pull recesses 40 and pull tape end down freeing said tape end from the tape end holding area 41 (FIG. 20).
[0062] 4. Extract length of tape desired by pulling tape end down making allowance for the tape length required to run from the tape transfer area 42 to the tape cutoff slot 39 (FIG. 21)
[0063] 5. Raise extracted tape length causing the portion of said tape length closest to the tape roll to become adhered to the tape end holding area 41 (FIG. 22).
[0064] 6. Close tape end protector cutoff snap-cap 51 by swivelling cap up until the snap-cap closure nodes 55 engage whereby the cutoff extrusion 57 will have caused extracted tape length to separate. | A portable wearable adhesive or other type tape roll dispenser that may be intended to dispense a single or multiple tape rolls. The dispenser has an enclosed housing and a cap that covers the area where the tape passes from the housing and beyond the area where the tape is separated from the tape roll or rolls. The dispenser can be worn on a belt or carried an equipment and completely protects the tape product from foreign object damage. | 1 |
FIELD OF THE INVENTION
[0001] This invention relates generally to the art of injection molding apparatus and, more particularly, to an improvement in injection molding apparatus check valve assemblies as applied to restrict backflow of a plasticized polymeric material during an injection stroke of the apparatus. The specific improvement comprises the addition of abrasion-resistant layers securely attached to friction wear surfaces of an injection molding check valve.
BACKGROUND OF THE INVENTION
[0002] Injection molding of plasticized polymeric materials including plastic and/or elastomeric type materials has been known and practiced for a long time. These type of apparatus are conventionally associated with various molding machines which are adapted for receiving the plasticized polymer and forming it into many useful parts and/or products.
[0003] Injection molding apparatus of the type alluded to are generally comprised of a feedscrew or auger member rotatably carried within a substantially cylindrical barrel, the screw effectively moving and plasticizing the polymeric material throughout the length of the barrel towards an exit end where it is forcefully injected into a molding machine for forming and curing of the material into the desired end product. At an exit end of the feedscrew there is conventionally mounted a check valve assembly which is designed to meter out the proper amount of plasticized material by a pressure reactive motion of the valve to effectively shut off the supply of material and to thereafter force the desired volume of plasticized polymer out of an exit nozzle and into the mold cavity of the molding machine.
[0004] Many improvements in this art have been suggested and applied to the injection molding apparatus and these, to an improved configuration of the feedscrew member and/or to the check valve assembly to gain greater efficiency in the injection operation by shortening the injection cycle period. Obviously, a shorter cycle period of the injection molding apparatus will also result in an increase in the number of parts which may be produced inasmuch as the molding machines associated therewith may also be configured to accept and form more individual parts.
[0005] These improvements in the injection molding apparatus have fairly coincided with advances in the polymer science and technology which has provided improved material chemistry. The improvements, however, have not been without problems as there is now a noticeable increase in wear of the various member elements which comprise the injection molding apparatus. For example, it has been determined that no natural lubricants are available in many of the polymeric materials and this lack of lubrication increases the friction and therefore also the heat generated in plasticizing and injecting the material. Furthermore, it is not possible to add a lubricating material to the process as these tend to contaminate the polymer and this affects the quality of the finished molded product.
[0006] In view of the above, friction wear of critical working elements of the injection molding apparatus is a major and continuing problem in the industry as these must be replaced at regular and, in some instances, very short intervals.
[0007] It is, of course, generally well-known and recognized by those knowledgeable in this art that the various working elements of the injection molding apparatus are comprised of very expensive tool and/or alloy steels, and this, because of the exceptional wear that these elements experience in this type of process. Thus, the very short service lifetimes of these elements will naturally also effect an increase in the cost of the molded parts being produced.
[0008] The following prior art patents fairly represent what has been done in attempts to improve the injection molding apparatus: U.S. Pat. Nos. 3,698,694; 4,106,113; 4,105,147; 4,472,058; and 4,988,281. Further, U.S. Pat. No. 3,209,408 addresses the friction wear problem by providing a ball-bearing configured check valve assembly. Such type ball-bearing configurations are also evident in some of the above-listed prior art patents. In addition, U.S. Pat. No. 4,530,605 attempts to alleviate part of this problem by providing a rapid take-down configuration for a check valve assembly such that when worn parts need to be replaced this may be done quickly and efficiently with the least amount of down-time. From this it should be apparent that the friction wear problem of critical elements of an injection molding apparatus still exists and this, irrespective of the various advances in the art.
[0009] Our prior U.S. Pat. No. 5,167,971 helped to solve the problem by reducing the amount of wear on the various wear surfaces of the valve assembly, however still further improvement in abrasion resistance has been achieved by this present invention by providing a layer covering the wear surfaces of the valve assembly which exhibits even further abrasion-resistance.
[0010] It is, therefore, in accordance with a primary aspect of the present invention an object to provide an improved check valve assembly for an injection molding apparatus wherein the service lifetimes of the various working elements is increased such that many more molded products may be produced before it becomes necessary to replace the working elements of the apparatus.
[0011] In accordance with another aspect of the invention it is an object to provide an improved injection molding apparatus check valve assembly which may be made from less expensive base metal and/or tool steel than now applied for these type elements while also providing an operational service life which is greatly for extended over what is available with presently made check valve assemblies.
[0012] An even further object of this invention is to provide an abrasion-resistant layer covering the wear surfaces which may be adhered to the metal wear surfaces without the use of heat being applied to the metal surfaces which might affect the base metal hardness.
[0013] Another object of the invention is to provide an abrasion-resistant layer having lower frictional heat due to density of the layer.
[0014] An even further object of the invention is to provide a preformed layer which may be adhesively attached to any hardness of metal.
[0015] Another object of the invention is to provide a preformed layer which may be adhesively attached to stainless steel and corrosion resistant high nickel alloys.
SUMMARY OF THE INVENTION
[0016] This invention is a check valve assembly for an injection molding apparatus having a rotatable and axially translatable feedscrew within a barrel bore and adapted for moving a polymeric material through the valve assembly towards an exit chamber of the apparatus, the check valve assembly characterized by: a valve body member attached to the forward end of the feedscrew and moveable with the feedscrew, said body member having at least one valve seat surface thereon, an axially slidable member mounted on the body member for limited axial movement thereon, said slidable member having; at least one valve seat surface which frictionally engages a corresponding valve seat surface on the body member, and a circumferential surface at its outside diameter which frictionally engages the inner surface of the barrel bore, the improvement comprising a substantially abrasion-resistant preformed layer securely attached to at least part of the frictionally engaging surfaces of the apparatus, said preformed layer effectively reducing frictional wear between coacting frictionally engaging surfaces and between the surfaces and the plasticized material as it is moved through the check valve assembly.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] These an other advantages and features of the invention will hereafter appear for purposes of illustaration, but not of limitation, in the accompanying drawings, in which like-reference numerals are used to identify like elements and wherein:
[0018] [0018]FIG. 1 is a side elevational view, in cross-section and with various parts broken away, illustrating a state-of-the-art injection molding apparatus as may benefit from the concepts taught by the present invention;
[0019] [0019]FIG. 2 is a greatly enlarged elevational view, in cross-section, of but a portion of the injection molding apparatus shown in FIG. 1 illustrating the application of the present invention; and
[0020] [0020]FIG. 3 is a greatly enlarged elevational view, in cross-section similar to FIG. 2 but showing a slightly different modification of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0021] In the drawing, FIG. 1 illustrates an injection molding apparatus generally indicated by reference numeral 10 . The apparatus 10 conventionally comprises a substantially cylindrical barrel 12 having a specific longitudinal length and it will be recognized that only the exit or output end of the barrel 12 is shown in the drawing. Of course, and as is well-known and understood in this art, an input end (not shown) will include a hopper mechanism for feeding various type of materials into the barrel 12 and the manner of doing this is not an important consideration of the present invention.
[0022] The barrel 12 may be characterized by a bore 14 centered on a longitudinal axis as indicated by the line Ax-Ax in the drawing. The exit end of the barrel 12 is generally indicated by reference numeral 16 and it may comprise an end cap member 18 which is affixed at 20 to the end of the barrel 12 by any of various well-known methods and/or techniques. The end cap 18 is characterized by a through-bore 22 , a partial portion of which is conically shaped as at 22 a and it connects into an exit bore 24 of a nozzle tip 26 . The nozzle tip 26 is adapted for a mating relationship of the injection molding apparatus 10 to a molding machine (not shown) in the well-known and understood manner of such apparatus.
[0023] A feedscrew member 30 is mounted co-axially within the bore 14 of the extruder barrel 12 and it is characterized by a helically oriented thread 32 having a land portion 34 exhibiting an outside diameter D 1 which is substantially but not exactly equal to the inside diameter D 2 of the bore 14 . A slight frictional engagement between the two is evident when the feedscrew 30 is rotated within the barrel bore 14 . The feedscrew 30 has a body 36 exhibiting an outside diameter D 3 which is less than the outside diameter D 1 of the thread 32 by a specific amount and it may be appreciated that a rotation of the feedscrew 30 will effect a movement of any material caught between the outside surface of the feedscrew body 36 and the inside surface of the bore 14 toward the exit end 16 of the apparatus 10 .
[0024] The feedscrew member 30 has an extruder check valve assembly 40 mounted to its forward end and valves of this type may comprise two or more separate but co-operating parts or elements as evidenced in various of the prior art patents. The particular check valve 40 shown in the drawing comprises a valve body 42 characterized by a conically-shaped tip end 44 and a shank end 46 which has a plurality of threads 48 for a portion of its length. The valve body 42 is affixed to the forward end of the feedscrew 30 by way of the shank end 46 being threadably engaged within a threaded bore 38 at the end of the feedscrew 30 . The conically-shaped tip end 44 is shaped to mate with the conically-shaped bore 22 a such that any material within the forward portion of the barrel bore 14 will be forceably directed into the exit bores 22 and 24 and out of the exit orifice 28 by an axial movement of the feed-screw 30 into the end cap member 18 . It is, of course, well-recognized and understood that the feedscrew 30 is connected to a power source (not shown) which controls its rotational and/or axial motion and the particular power means, therefore, is not important to the scope of the present invention.
[0025] The shank end 46 of the valve body 42 has a shoulder 50 formed between the smaller diameter threaded portion 48 and a larger diameter valve passage portion 52 , the shoulder 50 providing an axial stop for a valve seat ring 54 carried on the smaller diameter portion 48 . The valve seat ring 54 has a forwardly-facing valve seat bearing surface 56 and it is further characterized by an outside diameter which is substantially equal to the diameter D 3 of the feedscrew body 36 . As clearly evident in the drawing, the valve seat ring 54 ismaintained in position between the shoulder 50 and the terminal end of thefeedscrew 30 when the valve body 42 is threadably engaged within the bore 38 in the end of the feedscrew.
[0026] The valve seat ring 54 comprises the rearward valve seat surface 56 of the check valve assembly 40 while a forward valve seat surface 58 is formed on a backside annular surface of the conically-shaped tip end 44 . The forward valve seat 58 has a number of axially oriented flute passages 60 passing therethrough and the purpose of these will become apparent as this description proceeds.
[0027] The check valve assembly 40 further comprises a check ring member 70 which is mounted about the shank portion 52 of the shank end 46 and it is movable in the axial direction between the rearward valve seat 56 and the forward valve seat 58 . The check ring 70 is further characterized by frustoconical valve seat surfaces 72 and 74 , the valve seat surface 72 being in a position to sealingly engage the rearward valve seat 56 of the valve seat ring 54 while the valve seat surface 74 is in a position to sealingly engage the forward valve seat surface 58 on the valve body 42 . The valve seat surfaces 56 , 58 , 72 , and 74 are obviously mating surfaces and these may be disposed at an angle within the range of 0°-30° with respect to a radially oriented plane which is positioned orthogonally on the Ax axis.
[0028] Further with respect to the check ring member 70 , it has an outside diameter surface 75 , which is substantially but not exactly equal to the inside diameter D 2 of the bore 14 . While a sealing type engagement is effected as between the check ring 70 and the bore wall 14 such that material moving through the bore may not pass therebetween, the check ring is movable in the axial direction so as to be alternately engageable with either of the forward valve seat surface 58 or the rearward valve seat surface 56 . The check ring 70 also has an inside bore diameter which is larger than the outside diameter of the the forward portion 52 of the shank end 46 about which it is mounted. In this configuration, an annular passage indicated at reference numeral 76 is evident and it provides a pass-through for polymeric material when the check valve the check valve assembly 40 is in the “valve-opened” position as shown in the drawing.
[0029] In the operation of the injection molding apparatus 10 , it will be recognized that a material distribution chamber generally indicated by reference numeral 80 may be establish ed between the tip end 44 of the check valve assembly 40 and the conically-shaped bore 22 a of the end cap member 18 . When the volume of the distribution chamber 80 is established for a particular molded part, the feeds crew 30 is maintained in its axial position within the barrel bore 14 but it is rotated about the Ax axis. This rotation of the feedscrew 30 effectively moves polymeric material being fed into the barrel 12 longitudinally down the bore 14 towards the exit end 16 . The movement of material effectively also moves the check ring 70 into axial engagement with the forward valve seat surface 58 as shown in the drawing. Polymeric material is thus able to move through the check valve assembly 40 by way of the open annular passage 76 and the axial flute passages 60 and then into the distribution chamber 80 . As the distribution chamber 80 is filled, an injection stroke of the feedscrew 30 causes the check ring 70 to move into axial engagement with the rearward valve seat surface 56 of the valve seat ring 54 . Initiation of this powerful injection stroke of the feedscrew 30 in the axially forward direction forces any material within the chamber 80 out of the exit orifice 28 and into a relatively positioned molding chamber (not shown).
[0030] From the foregoing description of the injection molding apparatus 10 , it must be appreciated that the relative motions as between the various member elements of the apparatus generates heat which also increases the friction component as between the members. This is further aggravated by heat being generated within the polymeric material as it is processed through the apparatus and by a friction component which exists as between the material itself as it passes over the various member element surfaces. It will, of course, be recognized that the operational service life of the various members will be shortened by the amount of wear of critical surfaces and especially the valve seat surfaces of the check valve assembly 40 which actually govern the operation of the injection molding process.
[0031] Referring now to FIG. 2 of the drawings, a greatly enlarged elevational view of a portion of the apparatus 10 of FIG. 1 is illustrated. In this figure, like-reference numerals are used to designate like elements of FIG. 1 and the primed reference numerals are used to indicate the improved elements of the apparatus in accordance with the concepts of the present invention.
[0032] The showing of FIG. 2 is of the forward end of the feedscrew member 30 which carries the check valve assembly 40 in axial position at it forward end. The check valve assembly 40 ′ shown in the figure is an improved design wherein various of the element surfaces which exhibit exceptional wear and which are critical to the operation of the injection molding apparatus are covered with a hard and substantially abrasion-resistant preformed layer securely attached to the wear surfaces which dramatically increases the operational service life of the check valve assembly 40 ′.
[0033] The preformed layers are shown in the drawing by the stippled areas and, very clearly, these are the valve seat surfaces of (a) the check valve body at 58 ′, (b) the valve seat ring at 56 ′, (c) the check ring valve seat surfaces 72 ′ and 74 ′, and the check ring outside diameter surface 75 ′.
[0034] It will be recognized that various types of ceramic materials may provide the desired abrasion resistance and these may also be applied in a similar manner to the valve seat and other frictionally engaging wear surfaces wear surfaces. For example, ceramic materials taken from the group comprising the ceramic oxides may be fired to the desired hardness and preformed into a layer of a shape and size similar to the wear surface to be covered and adhesively attached to the wear surface.
[0035] After the layers are attached to the selected wear surfaces of the valve parts, the layers can then be machined to the desired final gauge thickness. For such ceramic layers, a final gage of not less that 0.010 inch, (0.254 mm) is preferable.
[0036] One of the preferred ceramic materials which provides an excellent abrasion resistance is a high alumina aluminum oxide. Another ceramic oxide which is also a good choice for abrasion resistance is zirconia and in particular Cerium Oxide Partially Stabilized Tetragonal Zirconia Polycrystal.
[0037] The ceramic oxides are considered preferable for use on the forward valve seat surface 58 ′ on the back side of the conically shaped tip end 44 , the rearward valve seat surface 56 on the valve seat ring 54 , and the forward and rearward valve seat surfaces 72 and 74 on the check ring 70 . The ceramic layers described previously are attached to the wear surfaces of the valve by a high temperature adhesive having the required physical properties to withstand the environment in which it is to used within the valve assembly.
[0038] The flat ceramic oxide layers previously described are not suitable for use on the OD surface of the check ring 70 and therefore a carbide layer which may be curved to encircle the outside diameter surface 75 of the check ring 70 and welded to the surface 75 . It is also desireable to use a carbid layer on the rearward valve seat surface 56 on the valve seat ring 54 . When carbide layers are used it is preferable that the layers exhibit a final gauge thickness of not less than 0.005 inch, (0.127 mm).
[0039] This invention, therefore, is not limited to a particular ceramic, metal, and/or metal alloy layer but, in the broades sense covers any high abrasion-resistant material which may be adhesively attached or if carbide layers are used, they are attached to the wear surfaces by welding or brazing.
[0040] Finally, it will also be recognized that when such abrasion resistant layers are used, the underlying base metal may comprise a less expensive metal and/or metal alloy than presently being used for these parts. For example, the very expensive tool and alloy steels presently being used for the valve seat ring 54 and the check ring 70 may be replaced with a number 4150 steel which costs ninety-five percent less. Obviously, a great savings in materials may be realized by the application of the present invention.
[0041] [0041]FIG. 3 shows a different embodiment from that shown in FIG. 2 in which similar parts are shown with a double prime (″) instead of a single prime (′) as used in FIG. 2. In FIG. 3, the rear end of the conical shaped tip end 44 ″ is divided into two parts with a bead seat ring 45 positioned against the rear end of the tip end 44 ″. A valve seat ring 54 ″ has a forward tubular extension 55 which bears against a rear annular surface 45 a on the ring 45 and holds it in position. All the remainder of the layers 56 ″, 58 ″, 72 ″, 74 ″ and 75 ″ are similar to those similar numbers described in FIG. 2. Except for the addition of ring 45 and tubular extension 55 , all the rest of the parts of the assembly shown in FIG. 3 are the same as in FIG. 2 and the same layer material of ceramic oxide or carbide material can be used.
[0042] While certain representative embodiments and details have been shown for the purpose of illustrating the invention, it will be apparent to those skilled in this art that various changes and/or modifications may be made therein without departing from the spirit or scope of the invention. | An injection molding apparatus which includes a check valve assembly mounted at the forward end of a feedscrew, the valve assembly having forward and rearward valve seat surfaces which co-act in a first position to allow a plasticized polymeric material to enter and flow through the valve into an injection chamber and which co-act in a second position to stop any additional material from entering the valve assembly. The second valve position is effected by a feedscrew injection stroke which generates a back pressure to close the valve, the back pressure moving a check ring of the valve assembly into a position to block entry into the valve. The valve seat surfaces are covered with a preformed layer of ceramic material and/or metal alloy which effectively increases the abrasion resistance of the valve seat surfaces and thus also increases the wear service life of the check valve assembly. Other wear surfaces of the valve assembly may also be coated for abrasion resistance. | 1 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims priority from EP 95830471.9, filed Nov. 7, 1995.
BACKGROUND AND SUMMARY OF THE INVENTION
The invention relates to a control circuit for an injector of an internal combustion engine. More specifically the invention relates to an injector control circuit which finds application in the motor vehicle field.
The operating principle of a known electronic injection heat engine fuel supply system is based on the possibility of opening a path for the fuel by means of an electronically controlled valve called an injector.
An injector is typically constituted by a nozzle which can be closed by a shutter element in the form of a pin or needle. This shutter element is typically urged by a spring towards the nozzle so as to shut it.
Opening of the injector is triggered by a magnetic field which is obtained by controlling the current in an inductor wound around a core so as to withdraw the shutter element by overcoming the action of the associated spring.
For the purpose of reducing the dissipation of power and therefore heat, the control operation is split into two phases:
a first phase during which it is necessary to open the injector and therefore during which a high magnetic field is necessary (peak phase),
a second, subsequent phase in which the injector must be maintained open, in which a magnetic field of lower intensity is sufficient (maintenance phase).
In FIG. 1 is plotted the typical variation of the injector control current Il, as a function of time t. As can be observed, the current Il in the injector winding or inductor has a peak Ip of high value in a first phase after which it falls to and remains substantially constant at a lower value Im. The undulating variation of the current Il in the maintenance phase is due to the use of control circuits of the commutation type which make it unnecessary to have active elements in the linear zone and therefore reduce the power dissipation.
Because of problems related to the specific application, the transfer from the peak phase to the maintenance phase must take place rapidly, that is to say with a steep wave front. This can be achieved by recirculating the current Il at high voltage in the injector winding.
For a better understanding, a prior art injector control circuit is shown in FIG. 2.
When the current Il in the winding L reaches the peak value Ip a voltage comparator CP commutes causing a DMOS transistor Q2 to turn off. The voltage comparator CP uses a measurement resistor RS to detect the current through the winding L and is connected to a voltage reference source Vref in such a way as to commute upon reaching the peak value Ip. The output of the comparator CP is connected by means of an interface circuit LOG to the gate terminal of the transistor Q2 which is in series with the winding L.
The circuit further includes a bipolar PNP transistor Q1, the base of which is connected to the supply VCC of the circuit, and the collector of which is connected to the gate of the transistor Q2. The emitter of the transistor Q1, on the other hand, is connected, as illustrated, to one terminal of a plurality of series connected zener diodes DZ1, DZ2, DZ3 . . . DZn connected, as illustrated, to a common node A between the winding L and the DMOS transistor Q2. A resistor R3 is also provided as biasing resistor for the gate of the transistor Q2, connected between the gate of the transistor Q2 and ground, through which flows a current I.
If the Lenz law is applied one has:
v(t)=-Ldi(t)/dt.
The voltage on the node A rises until it reaches a value given by:
V(A)=VCC+VCL+Vbe(Q1)
where:
VCL=VDZ1+. . . +VDZn
Where VDZ=the zener voltage.
The number of zener diodes necessary depends on the voltage value at which it is desired to drain off the load current through the DMOS transistor Q2, which remains in conduction because of the current I which fixes its gate voltage. Through the recirculation the current Il falls to the maintenance value Im.
This known prior art circuit, however, has problems of stability due to the fact that the resistor R3 which biases the gate of the DMOS transistor Q2 in the recirculation phase must be of low value in order to discharge the gate of the transistor Q2 quickly. Moreover the parameter gm=1c/vt of the transistor Q1 must be high since it is necessary to provide sufficient current to raise the voltage on the gate of the transistor Q2 whereby to hold it in conduction in the recirculation phase.
Moreover, if an interruption occurs in the supply line while the recirculation phase is active the circuit finds itself with the PNP transistor Q1 having a low base voltage (even 0 volts) , and therefore the collector of the transistor Q1 does not have a sufficient voltage to guarantee the conduction state of the transistor Q2. The recirculation to ground is no longer possible since the transistor Q2 does not remain conductive.
The object of the present invention is that of providing an injector control circuit in which the above-mentioned disadvantages can be resolved.
According to the present invention this object is achieved by an injector control circuit having the characteristics specifically set out in the claims which follow.
BRIEF DESCRIPTION OF THE DRAWING
The invention will now be described, purely by way of non-limitative example, with reference to the attached drawings, in which:
FIG. 1 is a cartesian diagram illustrating the operation of the circuit to which the present invention relates and has already been described with reference to the prior art;
FIG. 2 is a circuit diagram of a prior art device and has already been described;
FIG. 3 is a block-schematic diagram of a possible embodiment of the circuit according to the present invention;
FIG. 4 is a block-schematic diagram of the embodiment of FIG. 3; and
FIGS. 5a, 5b and 5c are schematic circuit diagrams of alternative embodiments of the circuit according to the invention.
DETAILED DESCRIPTION
In FIG. 3 is shown a possible embodiment of an injector control circuit according to the present invention. The present invention essentially consists of:
the introduction of a resistor R2, a transistor Q3, a current generator IB1 and a capacitor C between the terminal A and the collector of the transistor Q1 to eliminate the problems relating to the loss of stability,
the positioning of two zener diodes (for example DZA and DZB) on the base of the transistor Q1 with the introduction of the resistor R1, operable to prevent losses, to resolve the problems related to the compatibility of the recirculation structure during interruptions to the supply line.
In this case the voltage on the node A in the recirculation phase reaches the value given by:
V(A)=VCC+VCL+Vbe(Q1)+R2*IZ
where IZ is the current which flows through the zener diodes DZ1, . . . , DZn.
It is observed that the term VCL is the same as in the preceding case (FIG. 2) because it is given by the sum of the voltages VDZ1+. . . +VDZn+VDZA+VDZB, the overall number of zener diodes being unchanged.
In this way, if the voltage on the supply line should fall, the gate of the transistor Q2 remains biased and the transistor Q3 in conduction because the two zener diodes DZA, DZB connected to the base of the PNP transistor Q1 and supplied via the resistor R1 provide sufficient voltage to the base of the transistor Q1 for the collector of this transistor Q1 to have a sufficiently high voltage.
There now follows an analysis relating to the stabilization of the circuit according to the invention. The capacitor C, which is integrable, serves to return the circuit to a classic "dominant pole" structure in which the so-called pole-splitting of the capacitor C is effected for separating the input and output poles of the operational amplifier Amp of FIG. 4. The circuit of FIG. 4 is equivalent to the circuit of FIG. 3 as far as the gain is concerned. These poles, of the transfer function of the circuit in question, are given by the parasitic capacities of the structure. Moreover, the gain-band product of the circuit is controlled in that gm is controlled.
It can be seen that gm is controlled because the transistor Q1 is supplied with a constant current determined by the current generator IB1 and, moreover, if a very small gm should be sufficient it is possible to introduce an emitter degeneration constituted by the resistor R2. In fact, the current of the generator IB1 cannot be reduced excessively because it must be able to discharge the base of the transistor Q3 quickly. In this way, if the resistor R2 has a very high value one has that:
gm=1/R2
and therefore gm is controlled.
Consequently, the biasing current of the two series of zener diodes is constant:
IZ DZA,DZB!=(Vbe(Q1)+R2*IB1)/R1
IZ DZ1 . . . DZn!=IB1+(Vbe(Q1)+R2*IB1)/R1
Thus the fact that a lot of current is needed to put the transistor Q2 into conduction is no longer binding. The current in the zener diodes is adjustable through the current IB1.
Numerous advantages are therefore obtained with the present invention. These advantages are substantially as follows:
the feedback network of the recirculation structure is frequency compensated and therefore stable because the transistor Q1 is constant current biased,
gm is controlled (as a consequence of the preceding point),
the recirculation structure is compatible with interruptions in the supply line.
If the integration technology adopted for manufacture of the circuit should not allow the use of the transistor Q2, because the biasing voltage is too high, it is possible to use a DMOS type transistor Q4 in its place.
It is also possible to bias the collector of transistor Q3 on the drain terminal of the DMOS transistor Q2, as also the biasing of the transistor Q4.
These above-mentioned alternative embodiments are illustrated in FIGS. 5a, 5b and 5c.
Naturally, the principle of the invention remaining the same, the details of construction and the embodiments can be widely varied with respect to what has been described and illustrated, without by this departing from the scope of the present invention. | An injector control circuit for a motor vehicle electronic injection system utilizing current recirculation to control an injector actuation winding provided with a circuit configuration containing a constant current generator operable to eliminate the problems of instability and sensitivity to supply line interruptions to which prior art control circuits are subject. | 5 |
BACKGROUND OF THE INVENTION
This invention relates to systems for firearm security and control.
Firearms, since their earliest origin, have been valuable property. As such, there has always been a risk of loss by theft. Because of the gun's valuable nature, it has been and continues to be a target for theft. Many limited production, custom made, or highly engraved weapons, have price tags in the thousands of dollars. Typical sporting or personal weapons cost in the hundreds. It is not uncommon for a sporting enthusiast to own six or more weapons. Firearm dealers, on the other hand, may have hundreds of weapons in inventory. Security branches of local, state and hational governments own hundreds of weapons of all kinds for protection of the public. All firearm owners have the same problem of how to secure and control the unauthorized access to these firearms.
Previous efforts have been made to solve the problem of providing adequate firearm security. Early attempts included the gun cabinet, which is usually made of wood or a wood substitute, and glass. The glass provides windows in the cabinet doors, so that an owner can see his guns. Often the doors lock with a key, so that access by children is prevented. The gun cabinet is a piece of furniture, but is not much help against thefts, since access to the guns can be easily and quickly accomplished.
Another common security device is a locking gun rack, which is usually made of wood and light duty metal parts. The rack hangs on a wall and accommodates long guns in a horizontal fashion. Various retaining devices are used, which may lock all guns to the rack or individually lock single guns. Often, only one end of the gun is retained to the rack. The shortcomings of such devices include that the attachment is usually light duty and the thief merely has to remove the rack with the guns and later effectuate removal of the guns from the rack.
Security chests or safes made of heavy duty material, which can accommodate both long guns and handguns are satisfactory for security, but they suffer from shortcomings including that the weapons are not on display, the device is bulky, and moisture problems may develop within the enclosure.
Other existing devices include steel cable or chain threaded through the trigger guards of the weapons and padlocked to the gun rack or cabinet.
Alarm systems are also available, which would use an electric wire passed through the gun trigger guard, which if cut or broken triggers an alarm.
The slip-together methods of providing security include broad-ended pins passing through the trigger guard and being detachably fastened to rack devices, or bands or clamping means completely surrounding the stock or barrel of a long gun. Examples of the trigger guard locking pin devices are found in Worswick, U.S. Pat. No. 4,182,453, and Diebold, U.S. Pat. No. 2,667,274. A device utilizing a flat band to surround a gun stock is shown in Townsend, U.S. Pat. No. 3,857,491.
SUMMARY OF THE INVENTION
The instant invention pertains to systems for firearm security and control, and provides for security for either long guns or hand guns in flexible arrangements.
In one embodiment of the invention, said pins pass through the trigger guard of a firearm to be secured and may be of sufficient length to pass through a series of firearm trigger guards. A pair of curved enclosing pin members may be disposed and suitably positioned adjacent base members such that one of said enclosing pin members surrounds the stock of a long gun while the other enclosing pin member surrounds the barrel.
Individually key activated sliding mechanisms are selectively engaged upon the annular grooves or slots of the firearm engaging pins.
In an alternative embodiment, said bases contain a complement of openings positioned within said base members wherein locking pin disposed within said opening will engage the annular grooves or slots of said pins. Said engaging pins comprise elongated bodies having enlarged first ends and second ends containing openings for passage of a padlock therethrough.
Base members are fixedly mounted to a structure, such as a wall, and are equipped with openings into which may be inserted gun-engaging pins, which may be selectively engaged within the base members by control members. Said pins comprise elongated bodies containing enlarged first ends and second ends equipped with slots or annular grooves placed thereupon. Slideably movable locking members are selectively engaged with the slots or annular grooves of the second ends of the pins when said second ends engage the base members. Enclosing pin members have first curved ends and second ends containing annular grooves or slots thereupon. When said second ends of said enclosing pin members fully engage said base members, the curved ends of said enclosing pin members are positioned with said base members to form an entrapment. Said second groove containing ends of said enclosing pin members may be selectively engaged by slideably movable locking members within said base.
Electrical signal monitoring circuitry is associated with removal of said pin locking mechanisms to indicate removal or tampering with individual weapons.
One of the objectives of the invention is to provide individual firearm security.
Another objective is to allow firearms to be displayed to viewers, while being attractively secured.
Another objective is to provide an extremely flexible system where the long guns may be displayed in vertical or horizontal fashion and long guns and hand guns may be intermixed in the display.
Another objective of the invention is to provide a system for securing multiple hand guns with one locking device.
Another objective of the invention is to provide easy exchange of securing devices for hand guns or long guns.
Another objective of the device is to provide for a compact system of gun display and security.
Another objective of the invention is to provide for electronic indicator control of weapons tampered with or removed.
Another objective is to provide individual locking devices for individual firearms secured.
The foregoing objectives and others will be apparent from reference to the detailed description below.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front elevation of a combination of the invention securing long guns and handguns.
FIG. 2 is an exploded view in perspective of a trigger guard securing embodiment of the invention.
FIG. 3 is a partially exploded view in perspective of an alternative embodiment of the invention showing a trigger guard securing pin and a muzzle or gun stock enclosing member.
FIG. 4 is an exploded view in perspective of another embodiment of the invention employing electrical monitoring components.
FIG. 5 is a schematic of the electric monitoring circuit of FIG. 4.
FIG. 6 is a perspective view of an alternative embodiment of the system invention showing the securing of two long guns muzzle to muzzle.
FIG. 7 is a perspective view of an alternative embodiment of the invention showing a fixed ring securing member and a sliding ring securing member.
FIG. 8 is a front elevation of the invention securing a single handgun.
DETAILED DESCRIPTION
Referring to FIG. 1, the system invention is shown securing three long guns 1, 3 and 5, and two handguns 7 and 9. Bases 10 and 12 are fixed to structure 14 by mounting hardware 16. Long gun 1 is a lever-action-type weapon. Enclosing member 20 surrounds stock grip 11 of long gun 1 and passes through the lever 13 of long gun 1 and engages base 12. Enclosing member 22 entraps muzzle 15 of long gun 1 and engages base 10. Key receiving mechanism 24 is equipped with key opening 26 and is associated with enclosing member 22. Key receiving mechanism 42 is associated with enclosing member 20. Lever action long gun 3 is secured to the system invention with enclosing members 28 and 30. Enclosing member 28 surrounds stock 31 of long gun 3 and passes through lever 33 before engaging base 12. Enclosing member 30 entraps muzzle 35 of long gun 3 and engages base 10. Key mechanisms 38 and 40 are associated with enclosing members 30 and 28 respectively. As can be readily seen, long gun 3 could have as easily been oriented such that stock 31 became positioned adjacent base 10 and secured by enclosing member 30 with muzzle 35 adjacent base 12 and entrapped by enclosing member 28.
Long gun 5 has no lever. Pin 32 passes through trigger guard 51 of long gun 5 and engages base 12. Muzzle 55 is entrapped by enclosing member 34 which engages base 10. Key receiving mechanisms 44 and 46 are associated with enclosing member 34 and pin 32 respectively. Handgun 7 is secured to base 10 by pin 36 which passes through trigger guard 71 and engages base 10. Key receiving mechanism 48 on base 10 is associated with pin 36. Handgun 9 is secured to base 12 by pin 50 which passes through trigger guard 91. Key mechanism 52 is associated with pin 50.
Detail of the engaging mechanism of pin 102 with base 110 can be seen in the embodiment disclosed in FIG. 2. In this embodiment base 110 is seen from a rear perspective. Bolt 112 and washer 114 are installed through opening 116 for installation of base 110 to a wall or other structure. Expansion plug 118 is installed in base 110 such that head 120 of bolt 112 is not accessible after installation. Pin 102 is elongated and is equipped with enlarged end 122 on one end, and annular groove 124 formed in its opposing end 126. Shoulder 129 is formed by reduction in diameter of pin 102 at opposing end 126. Only opposing end 126 is of appropriate size to enter first passageway 134. Sleeve 128 is employed generally along pin 102 between enlarged end 122 and with opposing end 126 and is intended to cushion the abutment of gun parts to pin 102. Pin 102 is available to engage first passageway 134. Locking member 130 is provided to pass through intersecting passageway 132 in base 110. Transverse opening 135 is provided in locking member 130 for engagement of shackle 136 of padlock 138 therewith after passage of locking member 130 into intersecting passageway 132. First passageway 134 and intersecting passageway 132 intersect within base 110 such that elongated body 140 of locking member 130 engages annular groove 124 of pin 102 when opposing end 126 of pin 102 is inserted in first passageway 134. It is obvious that opposing end 126 must be inserted in base 110 before locking member 130 is inserted in intersecting passageway 132. The engagement of shaft 140 of locking member 130 with annular groove 124 of pin 102 prevents withdrawal of pin 102 from its engagement in first passageway 134 of base 110. When locked, shackle 136 of padlock 138 prevents removal of locking member 130 from base 110 which thereby prevents removal of pin 102 from base 110.
Referring now to FIG. 3, an alternative embodiment of the invention is shown. Base 210 is shown in perspective from the rear. Bolt 212 passes through washer 214 and opening 216 to engage the wall or other structure to which base 210 is mounted. Expansion plug 218 is placed over bolt 212 and serves to preclude access to head 220 of bolt 212 after installation of base 210 to a wall or other structure is effectuated. Pin 202 is shown engaged by sliding member 225 at annular groove 224 on opposing end 226. Pin 202 can therefore freely turn on its axis and still remain secure to base 210. Alternatively, pin 202 may be equipped with a slot such as slot 276 of enclosing member 272, in place of annular groove 224. Lock assembly 230 contains opening 241 into which passes sliding member 225 at protusion 232 which extends into opening 241. Sliding member 225 is selectively maintained in position engaging annular groove 224 of pin 202 by action of lock mechanism 231. Sleeve 228 encloses body 234 of pin 202. Enlarged end 222 is of size sufficient to exceed the size of opening of a trigger guard of a weapon. Recess 236 is provided in rear face 248 of base 210 to provide space to actuate sliding member 225 and to accommodate lock assembly 230. Indentation 238 is provided within recess 236 to accept fastener 240 for lock mechanism 231. Key 242 engages lock mechanism 231 from the front of base 210.
Mounting bolt 246 extends from rear face 248 of base 210 to mount to the wall or other structure to which base 210 would be mounted.
Recess 250 is formed in rear face 248 of base 210. Indentation 252 is formed within recess 250. Opening 268, having a non-circular cross sectional shape, passes through base 210 and communicates with indentation 252. Recess 250 and indentation 252 may be of equivalent configuration to recess 236 and indentation 238, respectively. Recess 250 may extend the length of base 210 if desired. Lock mechanism housing 255 is similar in cross sectional shape to opening 268. Lock mechanism housing 255 contains threaded portion 254, head 257, and opening 262. When installed in base 210, lock mechanism housing 255 extends through opening 268 and threaded portion 254 thereof is received by nut 270 which maintains lock mechanism housing 255 to base 210. Indentation 252 and recess 250 are of sufficient depth such that when installed in base 210, lock mechanism housing 255 does not intersect the plane of rear face 248 of base 210 and does not contact the wall or other structure to which base 210 may be mounted. Enclosing member 272 is curved and is approximately the shape of the letter J. Enclosing member 272 has a substantially linear first end 274 and a substantially linear free end 286, interconnected by curved body 282. First end 274 terminates in coaxial extension 275 which is of smaller diameter than the remainder of first end 274 of enclosing member 272 such that extension 275 may enter passageway 266 while shoulder 278 abuts base 210. When installed in base 210, termination 287 of free end 286 of enclosing member 272 almost touches base 210. Slot 276 is formed in extension 275 of first end 274 of enclosing member 272. When J-shaped enclosing member 272 is engaged in base 210 by the insertion of first end 274 into passageway 266, slot 276 is available to receive sliding member 260 which serves to lock enclosing member 272 to base 210, as well as to prevent rotation of enclosing member 272. Enclosing member 272 is equipped with sheath 280 along its entire length except for extension 275. Sheath 280 is of resilient material, such as foam rubber or poly vinyl chloride.
As can be readily understood, pin 202 can be made sufficiently elongate to secure more than one gun with the pin passing through the trigger guard of each gun. Similarly, enclosing member 272 may be equipped with first end 274 and free end 286 of sufficient length to accommodate enclosure of multiple gun muzzles or stocks.
Pin 202 can be interchanged with enclosing member 272 in passageway 266. The invention contemplates any combination of pin 202 and enclosing member 272 as desired by the user. When lock mechanism housing 255 is assembled in base 210, extension 256 of sliding member 260 is inserted into opening 262 of lock mechanism housing 255 from the direction of passageway 266 with respect to opening 268. Slot 259 is provided along extension 256 on the side of extension 256 directed to opening 268.
Lock cylinder 290 is elongate with a key-receiving end 291 and a second end 292. The face 293 of second end 292 is provided with protrusion 294 at its edge. Retaining clip 295 is provided upon second end 292 of key cylinder 290. Key 296 may be inserted in key-receiving end 291 of lock cylinder 290. As is well known in the art, when the proper key 296 is inserted in key cylinder 290, lock cylinder 290 may be rotated in the direction of key rotation.
The rotation of lock cylinder 290 causes the movement of protrusion 294 with respect to the lock mechanism housing 255. When lock cylinder 290 is installed in lock mechanism housing 255, protrusion 294 engages slot 259 of extension 256 of sliding member 260. The rotation of lock cylinder 290 effectuates sliding movement of sliding member 260 through the spacial repositioning of protrusion 294 occasioned thereby. Cylinder 290 is shown oriented such that protrusion 294 is spaced most distant from passageway 266. In this position, when assembled into lock mechanism housing 255, lock cylinder 290 would effectuate displacement of sliding member 260 at its maximal distance from extension 275 of enclosing member 272. When lock cylinder 290 is rotated by 180 degrees, it can be seen that protrusion 294 will be positioned in the opposite configuration from that shown in the drawing, and protrusion 294 will cause sliding movement of sliding member 260 toward extension 275 of enclosing member 272, thus providing engagement of edge 297 of sliding member 260, in slot 276 of enclosing member 272. This engagement of sliding member 260 with slot 276 prevents the rotation of enclosing member 272 around its first end 274. As can be seen, the selective positioning of lock cylinder 290 by use of key 296 effects selective entrapment of enclosing member 272 to bar 210.
Another embodiment of the invention is shown in FIG. 4. Parts shown in this figure which are identical to those shown in FIG. 3 will carry identical numbers. Base 310 is equipped for electrical monitoring. Recess 336 is provided in rear face 348 of base 310. It is intended that base 310 will be mounted to an immovable structure by bolt 346 such that rear face 348 abuts such immovable structure. Recess 336 may extend the length of base 310. Within recess 336 are indentations 312 and 314. Non-circular passageway 316 is provided to receive lock mechanism housing 255. Passageway 316 communicates with indentation 312. Nut 270 engages threaded portion 254 of lock mechanism housing 255. Passageway 318 passes through base 310 and communicates with recess 336. Passageway 318 is provided to receive extension 275 of enclosing member 272. Extension 275 extends from shoulder 278 and is of appropriate length such that when inserted in passageway 318, shoulder 278 abuts base 310 and extension 275 does not intersect the plane of rear face 348 of base 310. Sliding member 360 is provided with extension 356 on which is provided slot 359. Extending from central portion 361 of sliding member 360 in opposing direction to extension 356 is arm 320. Spring member 321 is mounted by screw 322 within recess 336 such that arm 323 of spring member 321 deflects upon the full insertion of extension 275 of enclosing member 272 into passageway 318 to the extent that shoulder 278 abuts base member 310. Bracket 324 has normally closed switches 326 and 328 affixed thereto by fasteners 329, and is mounted securely within indentation 314. Arm 323 of spring member 321 rests near upon plunger 330 of switch 326 in its relaxed state. When extension 275 of enclosing member 272 is fully positioned within passageway 318, extension 275 engages arm 323 of spring member 321 thereby deflecting said spring member toward switch 326, thereby depressing plunger 330 of switch 326 and causing switch 326 to open. Arm 320 of sliding member 360 rests above plunger 332 of switch 328 so long as lock cylinder 290 is positioned with protrusion 294 at its position most distant from passageway 318. When lock cylinder 290 is rotated by key 296, protrusion 294 which engages slot 359 of extension 356 of sliding member 360, forces sliding member 360 downward and causes arm 320 of sliding member 360 to engage and depress plunger 332 of switch 328. It is understood that alternative actuation of switch means may be employed and are contemplated by the invention.
In FIG. 5, a schematic of the electrical circuitry is shown. Suitable wiring is disclosed to connect a power source labelled as a battery, bulb 410 and switches 326 and 328. Sliding member 360 is shown positioned to engage extension 275. Extension 275 deflects arm 323 of spring member 321 causing switch 326 to be depressed and therefore be in its open state. Arm 320 of sliding member 360 also depresses switch 328 into open status. As can be readily seen, when sliding member 360 is moved away from extension 275, arm 320 will deactuate switch 328 allowing it to close and energize bulb 410. When extension 275 is removed from base 210, arm 323 of spring member 321 will return to undeflected position, thereby relaxing switch 326 and allowing it to return to its normally closed position, thus providing an alternative path of energization for bulb 410. Equivalent forms of wiring, signalization and supply of power are contemplated by this invention. It can readily be seen that if extension 275 is removed from base 310 or is not fully inserted into passageway 318, arm 323 of spring member 321 will not be deflected and will allow switch 326 to close energizing bulb 410 regardless whether arm 320 of sliding member 360 is in its downward position depressing switch 328 and causing it to be open. Monitoring is therefore available to indicate if lock cylinder 290 is in the unlocked position or to detect if enclosing member 272 is not fully inserted in passageway 318. Bulb 410 may be substituted with or may accompany other monitoring or measurement devices which are energized or selectively controlled upon the closing of either switch 326 or 328. For example, a recording mechanism could be used to collect data regarding removal or unlocking of any of the securing members associated with the system of this invention.
A further alternative embodiment of the invention is disclosed in FIG. 6. Three bases 408, 409, and 410 are mounted to a wall 414, by hardware enclosed by expansion plugs 418. Bases 408, 409 and 410 may be substantially identical. Long guns 403 and 405 are secured to bases 408, 409 and 410. Pins 402 and 404 secure trigger guard 453 of long gun 403 and trigger guard 455 of long gun 405 respectively. Pins 402 and 404 may be substantially identical. Muzzle 413 of long gun 403 and muzzle 415 of long gun 405 each extend into enclosed space 421 created by enclosing member 420 and base 409. Lock mechanism 450 selectively controls removal of pin 402 from base 408 and lock mechanism 452 selectively controls removal of pin 404 from base 410. Retaining pin 454 is installed transversely in base 409 preventing removal of enclosing member 420 which is equipped with a notch such as notch 526 of enclosed member 561 shown in FIG. 7.
FIG. 7 provides another alternative embodiment of the invention. Bases 508, 509 and 510 are mounted to immovable structure 514 by fastners 518. Lock mechanisms 550 and 552 selectively control pins 502 and 504 respectively, which secure the trigger guards 553 and 555 of guns 503 and 505 to bases 508 and 510, respectively.
Enclosed member 560 is shown fixed to base 509 by holding pin 566. Insertion of shaft 522 of enclosed member 561 into opening 531 of base 509 is intended. Transverse notch 526 is provided on shaft 522 and is engaged by holding pin 524 when holding pin 524 is driven into transverse passageway 533 of base 509. Transverse notch 526 may be substituted with a transverse aperture which similarly may be engaged by holding pin 524.
Opening 559 of enclosed member 560 receives muzzles 513 and 515 of guns 503 and 505 respectively. Additional pins 504 are installed in bases 508 and 510 but are not in use to secure guns. Pins 506 are also not in use but are featured with shanks 507 which are sufficiently elongated to pass through one or more weapons' trigger guards and insert into bases 508 and 510. Pin 540 is provided with ring 542 which surrounds shank 544 of pin 540 but may be removed when pin 540 is detached from base 509. Shank 544 is provided with transverse notch 546. Ring 542 is not sufficiently large to pass over head 548 of pin 550 when a gun's muzzle is inserted within ring 542. When shank 544 is inserted into opening 535 of base 509, a holding pin 564 may be driven into transverse passageway 537, wherein it engages notch 546 of shank 544. Transverse notch 546 may be substituted with a transverse aperture which similarly may be engaged by holding pin 564. It is intended that the muzzle of a long gun may be inserted through ring 542 and the stock of said long gun then be placed adjacent base 508 or base 510 and secured through its trigger guard by one of pins 506 to base 508 or 510.
In FIG. 8, an additional alternative embodiment of the invention is shown. Expansion plugs 618 cover mounting hardware used to secure base 610 to a wall or other structural component or other substantially immovable object. Lock mechanism 612 is associated with pin 602 which secures handgun 620 to base 610. Supports 622 and 624 provide stops to hold handgun 620 in an upright position.
Throughout this specification, it is to be understood that bases 10, 12, 210, 310, 408, 409, 410, 508 and 510 may be fully interchangeable. Furthermore, pins 102, 202, 402, 404, 502, 504 and 540, enclosing members 272, 420, enclosed members 506 and 561 may be constructed to be interchangeably insertable within passageway 266 of base 210 as shown in FIG. 3 or in passageway 134 of base 110 shown in FIG. 2 or in passageway 318 of base 310 of FIG. 4. Furthermore, it is to be understood that enclosing members 272 and 420 may likewise be interchangeably inserted within passageway 134 of base 110 or passageway 266 of base 210 and secured either by a sliding member such as sliding member 260 of FIG. 3, 360 of FIG. 4 or by locking member 130 of FIG. 2. | Gun securing apparatus is provided which comprises a base, trigger guard securing pins selectively mounted to said base, having annular grooves or slots upon the length thereof, a locking member insertable in a transverse passageway of said base and intercepting said annular groove or slot of said pin, padlock means securing said locking member and engagement within said annular groove or slot of said pin. An alternative embodiment provides cam locking means which selectively engage the annular groove or slot of said pin member. Another embodiment provides a curved enclosing member having an end insertable with a passgeway of a base, said end having a groove or notch thereupon. Cam lock means selectively engage said notch or groove of said enclosing member effectively preventing removal of said enclosing member from said base. Another embodiment provides electrical monitoring elements to indicate unlocked condition of the cam lock member of the invention or incomplete insertion of the pin or enclosing member in the passageway of the base. Another embodiment provides a fixed circular locking pin member or a curved locking pin member and a movable ring securing member with a partial securing of long guns. | 8 |
BACKGROUND
[0001] 1. Field of the Invention
[0002] The present application relates generally to a termiticide treatment process, more particularly, to a system and method for using termiticide.
[0003] 2. Description of Related Art
[0004] Termites are a common problem facing a large number of residential and commercial structures. Termites feed on dead plants (i.e. wood) among other things. There are three ecological groups of termites, namely drywood termites living in hardwood forests, dampwood termites living in coniferous forests, and subterranean termites living in diverse areas underground. Subterranean termites build tunnels to look for food and travel typically below ground.
[0005] Various treatments are available to prevent or kill termites. In particular with subterranean termites, ground treatments are necessary. For homes, treatments are done in the walls and around the foundation via the application of termiticide in trenches. Additional treatments are commonly done beneath the slab or cement foundation. This includes the drilling of a hole into the foundation at spaced intervals, the injection of termiticide into the hole, and the filling of the hole in a concrete patch.
[0006] It is desirable to separate the moisture from the termiticide from the cement patch used to cover the hole, so as to allow for proper setting of the concrete. Typically a paper product is wadded up and stuck in the holes. These are less effective because the paper absorbs the moisture and wicks it up to the concrete or pulls the moisture out of the concrete, each affecting the setting of the concrete negatively. In some cases rubberized plugs have been used. These are hardened and work to prevent the absorption of moisture but are extremely difficult to set in the hole. Additionally they are rather expensive. Another disadvantage of the hardened plastic plugs are that they are not removable from the holes. In order to remove them, they must be drilled out.
[0007] It is desirable to have a plug for the holes that prevents absorption and is easy to set in the hole to a selected depth to give room for the cement patch. Additionally it is recognized that a number of holes are to be drilled in concrete around the exterior of a structure and are subject to rain and moisture. It is undesirable to leave the open holes exposed over time before and after injection of the termiticide. Therefore it is advantageous to have a plug that is removable to allow the holes to be drilled, plugged for a period of time, and then removed when the termiticide is ready to be injected.
[0008] Another disadvantage of present methods for treating with termiticide is the method of setting the “plugs” to a proper depth in the hole. The depth can depend on a number of factors. Currently, pencils are used to push down the plug. It is very difficult to use a pencil with holes of different diameters and also measure the appropriate depth of the plug. The setting of plugs takes a considerable amount of time and results in large man-hour costs.
[0009] It is desirable to have a better tool that can fit holes of various diameters and easily sets a particular depth for each plug. It is ideal if such tool allowed for the adjustment of the depth setting as well. This would decrease man-hour costs and labor tremendously and help to ensure a more predictable quality.
[0010] Although some strides have been made in treating for subterranean termites, considerable shortcomings remain.
DESCRIPTION OF THE DRAWINGS
[0011] The novel features believed characteristic of the application are set forth in the appended claims. However, the application itself, as well as a preferred mode of use, and further objectives and advantages thereof, will best be understood by reference to the following detailed description when read in conjunction with the accompanying drawings, wherein:
[0012] FIG. 1 is a side view of a termiticide flex plug system according to the preferred embodiment of the present application;
[0013] FIG. 2 is a side view of a tool and a plug in the termiticide flex plug system of FIG. 1 wherein the plug is preset in a hole of a concrete slab;
[0014] FIG. 3 is a side view of the tool and plug of FIG. 2 with the tool locating the plug to a preselected depth;
[0015] FIG. 4 is a side section view of the tool of FIGS. 2 and 3 ;
[0016] FIG. 5 is a side view of a locating element used on the tool of FIGS. 2 and 3 ;
[0017] FIG. 6 is a side view of a plurality of plugs, as seen in FIGS. 2 and 3 , each of a different diameter;
[0018] FIG. 7 is a side view of a plurality of plug tips, as seen used in FIGS. 2 and 3 , each having a different tip diameter; and
[0019] FIG. 8 is a side section view of an alternative embodiment of the tool of FIGS. 2 and 3 for use in the termiticide flex plug system of FIG. 1 .
[0020] While the system and method of the present application is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the description herein of specific embodiments is not intended to limit the application to the particular embodiment disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the process of the present application as defined by the appended claims.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0021] Illustrative embodiments of the preferred embodiment are described below. In the interest of clarity, not all features of an actual implementation are described in this specification. It will of course be appreciated that in the development of any such actual embodiment, numerous implementation-specific decisions must be made to achieve the developer's specific goals, such as compliance with system-related and business-related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming but would nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure.
[0022] In the specification, reference may be made to the spatial relationships between various components and to the spatial orientation of various aspects of components as the devices are depicted in the attached drawings. However, as will be recognized by those skilled in the art after a complete reading of the present application, the devices, members, apparatuses, etc. described herein may be positioned in any desired orientation. Thus, the use of terms to describe a spatial relationship between various components or to describe the spatial orientation of aspects of such components should be understood to describe a relative relationship between the components or a spatial orientation of aspects of such components, respectively, as the device described herein may be oriented in any desired direction.
[0023] The system in accordance with the present application overcomes one or more of the above-discussed problems commonly associated with conventional termiticide treatment methods. Specifically, the system of the present application is configured to selectively seal and locate a plug in a hole of the concrete slab after the insertion of termiticide beneath the slab. The plug may be inserted prior to or after injection of the termiticide through the hole. Moisture is not permitted to transfer through or around the plug in the hole. The plug forms to the contour of the hole to create a seal. A tool is used to quickly permit the setting of the plugs to a proper depth. The tool allows for the presetting of depth. These and other unique features of the system are discussed below and illustrated in the accompanying drawings.
[0024] The system and method will be understood, both as to its structure and operation, from the accompanying drawings, taken in conjunction with the accompanying description. Several embodiments of the system are presented herein. It should be understood that various components, parts, and features of the different embodiments may be combined together and/or interchanged with one another, all of which are within the scope of the present application, even though not all variations and particular embodiments are shown in the drawings. It should also be understood that the mixing and matching of features, elements, and/or functions between various embodiments is expressly contemplated herein so that one of ordinary skill in the art would appreciate from this disclosure that the features, elements, and/or functions of one embodiment may be incorporated into another embodiment as appropriate, unless otherwise described.
[0025] The termiticide flex plug system of the present application is illustrated in the associated drawings. The system includes a plug configured to translate within the hole in the concrete slab to a predetermined location. A tool is operated by a user to push the plug into the hole. A plug tip is coupled to a lower portion of the tool and configured to extend into the hole. A locating element is coupled to at least one of the tool and the plug tip and is used to set a depth in which the plug tip will extend into the hole. The method includes selecting and coordinating the sizing of the plug and the plug tip. The locating element is set and the plug tip is secured relative to the tool. The user walks by each hole and inserts the plug tip into the hole to push the plug a predetermined distance into the hole as designated by the locating element.
[0026] Referring now to the drawings wherein like reference characters identify corresponding or similar elements in form and function throughout the several views. FIG. 1 in the drawings illustrates a side view of a termiticide flex plug system 101 according to the preferred embodiment of the present application. System 101 includes a plug 103 , a plug tip, 105 , a tool 107 , and a locating element 109 all configured to simplify the insertion and sealing of holes formed in concrete slabs formed during termiticide treatments. It is understood that this system and the following method may be used independently outside termiticide treatments.
[0027] Referring now also to FIGS. 2 and 3 in the drawings, the operation of system 101 is illustrated. Plug 103 is a reusable item in system 101 and is configured to be sacrificed in the hole. Plug 103 is located into the hole adjacent the surface of the concrete slab. When the moment requires, tool 107 is used to align plug tip 105 with plug 103 and press plug 103 further into the hole. Locating element 109 is shown as restricting the travel of plug tip 105 into the hole and setting it at a desired depth. Once set, the hole may be patched and filled. Prior to filling/patching of the hole, plug 103 may be removed from the hole as needed.
[0028] Referring now also to FIGS. 4-7 in the drawings, the various components and members of system 101 is illustrated. Plug 103 is configured to seal the hole to prevent the passage of liquid below the concrete slab. Plug 103 conforms to the contours of the hole and forms a seal along the interior surface of the hole. Plug 103 is made from one or more materials and is configured to prevent the passage of liquid and moisture through the hole. A preferred material for plug 103 is a closed cell foam. The closed cell nature of plug 103 prevents absorption liquid and moisture. As seen in FIG. 6 , plug 103 may come in a variety of sizes. Sizes are shown below each plug tip in a measurement of inches. The size of plug 103 is selectively chosen based on the size of the hole. The sizes of available plugs are shown. It is understood that the plug sizes may be different from those depicted.
[0029] It is preferred that the plug is slightly larger than the hole diameter to allow the plug to compress and conform to the interior surfaces of the hole, thereby creating the seal. The compressive nature of plug 103 also allows it to be removed and reinserted into the hole. In way of example, plug 103 may be used to temporarily seal the hole prior to the insertion to termiticide. This could prevent the introduction of rain or other moisture into the holes and affect treatment conditions. Plug 103 may then be removed to allow for the injection of termiticide and reinserted, all without the need to drill it out of the hole.
[0030] Referring in particular to FIG. 7 , various sized plug tips 105 are illustrated. Each illustrated plug tip 105 illustrated is of a different size. Sizes are shown below each plug tip in a measurement of inches. The size of plug tip 105 is selectively chosen based on the size of plug 103 and the hole. It is understood that the sizes of plug tip 105 may be different from those depicted.
[0031] Plug tip 105 includes a flared end 111 and a central shaft 113 . End 111 is configured to flare out from shaft 113 to a particular size dimension. End 111 is configured to match the relative sizing of plug 103 , however, end 111 is sized slightly smaller than the internal diameter of the hole to permit plug tip 105 to translate through the hole. Shaft 113 is configured to couple to tool 107 . One method of coupling is to use a threaded connection wherein tool 107 includes a female threaded end and shaft 113 is a male threaded end (see FIG. 4 ). Other methods of attachment are contemplated. For example, plug tip 105 may couple to tool 107 internally or externally. Additionally, threads may be used or ball springs and detents similar to those of sockets may also be used. It is important to note that plug tip 105 is detachable from tool 107 and may selectively be located in position relative to tool 107 .
[0032] Locating element 109 is in communication with plug tip 105 and configured to locate the depth of the plug in the hole. Element 109 is designed to have a diameter larger than the hole, such that when tool 107 is used to push plug 103 in the hole, locating element contacts a portion of the concrete slab and prevents the over protruding of plug tip 105 .
[0033] Many different methods exist to attach and operate locating element 109 . The depth of plug 103 in the hole is a measurement from the end of flared end 111 to a bottom surface of locating element 109 . To allow for the precise measurement of that depth measurement, one method of adjustment is to use a threaded connection. As seen in FIG. 4 , element 109 is in threaded connection with plug tip 105 . Locating element 109 may be set on shaft 113 to an appropriate depth measurement and then tip 105 be threaded into tool 107 . The contacting of element 109 creates a binding force that secures tip 105 . In the preferred embodiment, element 109 is a combination of one or more washers having either right and/or left hand threads. It is understood that other element 109 may be configured to couple directly to tool 107 as opposed to tip 105 . In this embodiment, tool 107 may have external threads.
[0034] Tool 107 is configured to provide an operator a handle 115 portion to grasp for operation and a lower portion for carrying tip 105 . Multiple shapes and sizes of tool 107 may be used. In the preferred embodiment, the internal threaded portion for tip 105 is sized to correlate with the smallest flared end 111 size used, so as to avoid issues where the shaft 113 creates a shoulder and restricts insertion through the hole.
[0035] Referring now also to FIG. 8 in the drawings, an alternative embodiment of system 101 is illustrated. Tool 207 is similar in form and function to that of tool 107 except that it includes a strike plate 117 for the operator to apply pressure and force. Tool 207 may be used in place of tool 107 in system 101 .
[0036] As stated previously, in operation a user selects the size of the plug and plug tip that will be used. The plug(s) will be located in the holes initially. Once the proper depth has been determined, the user will set the locating element 109 to the proper position and then secure the plug tip 105 to tool 107 . If element 109 coupled directly to tool 107 , then element 109 would be set and tip 105 would be secured to either a set predetermined station or to one of many optional stations. Once the tool, plug tip, and locating element are ready, the user walks along to each hole and merely protrudes the plug tip into the hole until the locating element contacts a portion of the concrete slab. If the hole sizes change, the plug tip may be interchanged. Furthermore, if the depth measurement changes, the locating element may be adjusted to a second station.
[0037] The current application has many advantages over the prior art including at least the following: (1) increased speed of setting the plugs; (2) proper seal to prevent passage of moisture through the hole; (3) reusable plugs; (4) infinite depth setting distances; (5) a locating element that is set for multiple uses; and 6) adjustable and interchangeable plug tips.
[0038] The particular embodiments disclosed above are illustrative only, as the application may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. It is therefore evident that the particular embodiments disclosed above may be altered or modified, and all such variations are considered within the scope and spirit of the application. Accordingly, the protection sought herein is as set forth in the description. It is apparent that an application with significant advantages has been described and illustrated. Although the present application is shown in a limited number of forms, it is not limited to just these forms, but is amenable to various changes and modifications without departing from the spirit thereof. | The present application includes a system configured to simplify the application of plugs into holes created in concrete slabs during a termiticide treatment process. The system includes a flexible plug for insertion into the hole one or more times. A plug tip is coupled to a tool and selectively adjusted to a particular depth. A locating element is included to prevent the over protruding of the plug tip in the hole. The tool is used by the user to insert the plug tip into the hole wherein the depth is governed by the location of the locating element. The plug tips may be interchanged or adjusted in depth along with the locating element. Once the plug has been located properly, a patch is then applied to the remaining hole. | 0 |
This application claims priority under 35 USC §119 to currently pending German application number DE 10 2005 058 743.7, filed Dec. 8, 2005 by Voith Turbo GmbH & Co. KG. The specification herein enclosed is a translation of the specification as filed with the German Patent Office.
FIELD OF THE INVENTION
The invention relates to a universal joint arrangement.
BACKGROUND OF THE INVENTION
Universal joint arrangements, in particular the bearing systems for suspension of the journal of a journal cross in joint yokes, for installation in propeller shafts are well-known in a number of designs for a multitude of application examples. Reference is made to the publication G 1757 d 08/02 1.000, “FEM-Simulation von Gelenkwellen mit inkompatiblen Netzen”, in which the problem of the deformations on the bearing and connection elements under load is disclosed.
Embodiments of universal joint arrangements are known for joint shafts, which comprise a journal cross which is supported by bearings in two joint yokes offset to one another by 90 degrees. The joint yokes themselves can be designed in one piece or in two pieces. For connection of the journal cross in the joint yoke a corresponding bearing arrangement is provided for the individual journals, which comprises a radial bearing and an axial bearing. In the process the radial bearings are always designed as anti-friction bearings (roller bearings), the axial bearings can be designed either as anti-friction bearings (roller bearing) or as friction bearings. For the arrangement of the axial bearing there are a number of possibilities, wherein however under consideration of the occurring deformations during the operation of the joint shaft a corresponding constructive layout of the individual elements of the suspension takes place. The problem of such a bearing arrangement lies in the fact that in the case of anti-friction suspension the individual anti-friction bearings, along with a high base torque, are additionally loaded by high torque impacts and simultaneous transversal accelerations, in particular in the case of use in rolling mill drives. These loads lead to elastic deformations of the joint yoke both in the region of the flange as well as also within the eye of the yoke. In reversing operation the deformations occur additionally with positive or negative value. These influences due to operation as well as design result in misalignments with an unfavorable load application in the bearing, namely a mismatch of the bore of the yoke, inclined position of the bore, spring deflection of the journal as well as a radial clearance in the radial bearing and the spring deflection of the anti-friction bearing, as is disclosed in the publication G 17 57 FIG. 12. The result is an uneven radial pressure distribution in the bearing bore, as a result of which locally high loads on the contact points of the anti-friction body of the radial bearing and excessive edge stresses arise. From the elastic deformations moreover relative movements between journal and bore of the yoke result in axial direction. If these relative movements are hindered by a too stiff bearing embedding, high constraining forces arise and with it high loads of the axial bearings, but only when the axial bearing is designed as an anti-friction bearing. In the case of anti-friction suspension this results in too high edge stresses in one segment of the axial bearing and in lifting of the rollers in the opposing segment. The unequal load results in a lessening of load bearing capacity. The constructive design, in particular the layout of the individual components, is in the process always to be adapted to the possible occurring deformation travels, so that it is not possible to provide a satisfying design independently of the knowledge of these influences.
One solution of this problem is known from the publication EP 1 167 796 B1 with an axial bearing in anti-friction bearing design. This is characterized by the special development of an axial bearing surface on a thrust ring. Here a free travel for the anti-friction elements is created solely through the development of the thrust ring on the basis of the worn material. The disadvantage of this design lies in the fact that the travel is consequently not to be predefined freely, but rather must be specified via the deformation travels determined in the case of specified operational load, as a result of which a complete rubbing contact of all anti-friction elements is not given for different loads, in particular in the partial load range and the negative consequences of the design according to the state of the art cannot be completely eliminated.
From DE 195 10 761 B1 a design of a journal bearing in bushing design anticipated as an axial bearing serves there as a thrust ring constructed as a plastic disk with elastic properties, which in the center exhibits a circular or circular-shaped limited contact surface protruding to the frontal area and near the edge an annular supporting surface, wherein the hollow spaces however only serve to absorb lubricants.
SUMMARY OF THE INVENTION
The invention is therefore based on the object of further developing a bearing system for universal joint arrangements of the initially named type, in particular for use in heavy propeller shafts in such a way that the named disadvantages can be prevented, i.e. said system exhibits a simple structure as well as a low number of components. The elimination of the negative influences in deformation of the torque transferring components to the bearing arrangement, in particular the axial bearing is to be achieved in the process independently from concrete types of load with the most standardized possible solution. The universal joint arrangement, in particular the bearing system and its individual elements should stand out in the process due to a low design and manufacturing expenditure as well as low costs.
A universal joint arrangement comprises a journal cross with two joint yokes offset to one another by 90 degrees and in reflected arrangement to the plane of symmetry of the journal cross located perpendicular to the joint axis. Each joint yoke comprises a flange part and two bearing parts, wherein each bearing part exhibits a bearing bore, in which the journals of the journal cross are supported. Each journal is in the process supported by means of a bearing arrangement, which comprises at least one radial bearing and one axial bearing, wherein the axial bearing is designed as a friction bearing. According to the invention the axial friction bearing comprises in accordance with a first solution attempt at least one separate axial friction bearing mold element which under formation of a first friction pairing supports itself at least indirectly on the joint yoke and a second friction pairing supports itself at least indirectly on the journal cross. The axial friction bearing mold element comprises a first plane frontal area and a second one which is characterized by at least one region of an elevation. The region of the elevation forms a support region, which in every function state forms a friction surface either of the first or second friction pairing. The axial friction bearing mold element is arranged in such a way that it rests without active operational load on the universal joint arrangement in the elevation region and elastically deflects under load in said elevation region, wherein the region outside of the elevation region at the first or second frontal area in every load state is free from contact with the connection elements. The elevation range forming a first support region is, referring to conventional solutions, arranged as it were in the region of low relative movements and with it of low elastic deformation, while they lie on the elevation range adjoining this free region in installation position in the region of greatest relative motion. This means that in regions of greatest relative movements even under load a resting of both sides on the axial friction bearing mold element is prevented and with it elastic deformations there can be eliminated.
The region of greatest axial relative movements is located in a cross-sectional plane perpendicular to the joint axis through the respective journal axis. On the side of the relieved radial bearing on this plane the relative movements are enabled by the recesses on the axial friction bearing mold element free from distortion. On the opposing side in the high pressure region of the radial bearing the axial bearing elements stand out from each other.
In accordance with a second solution attempt the axial friction bearing comprises a conventional axial friction bearing pressure disk and supports itself on a correspondingly molded connection element. The shaping corresponds in the process to the shaping described for the axial friction bearing mold element in the first solution attempt. Here too there are partial elevations provided on a frontal area of at least one connection element. This is achieved by means of molding in the case of shaping or production or reworking of the respective connection element or by subsequent connection to correspondingly molded elements, for example by means of material closure. In this case for example corresponding modifications are made to
a) the bearing bore, in particular in the case of design as a blind hole on the frontal area facing the journal b) the journal frontal area c) the bottom of the bearing bushing for the radial bearing or the bearing lid
These are preferably determined by a rotationally symmetrical design, i.e. an elevation, wherein the elevation is characterized viewed in cross-section by constant dimensions in axial direction and viewed perpendicular to it however by changing dimensions. By axial direction in the process the direction of the journal axis is understood.
With the solution according to the invention hence a partial elastic form closure is always realized, which even under the influence of high axial forces does not result in a damage of the bearing or of the connection elements. The known negative effects from the state of the art on the basis of the relative movements are compensated for in this connection by the form of the axial friction bearing mold element or of the connection element. Said connection element is in the process developed in such a way that it exhibits first regions, which are also termed as support regions, which are arranged preferably symmetrically on the element—axial friction bearing mold element or connection element—and in essence lie in the region of the plane, which is characterized by the journal axis and the joint axis or which extend on both sides from this plane in circumferential direction of the journal. These regions are in the process characterized by regions of greater cross-sectional areas, compared to the cross-sectional areas of the adjoining, inactive regions which are formed with the recesses. The enlargement of the cross-sectional area takes place viewed in installation position in the direction of the journal axis. In the regions of greater cross-sectional area a free of play resting against the connection elements always takes place, while in the inactive regions a resting is always prevented with certainty. I.e. in the regions of great relative movement recesses (material removal) prevent a resting of the connection elements under operational load. Through this shaping, which is realized as it were by material reductions in specified regions on the axial friction bearing mold element or the connection element, clearance is thus created for the relative movements of the connection elements occurring due to the deformation. This relates in particular to the connection elements for the radial bearing or the joint yoke. The cross-sectional difference or the material removals are in the process designed in such a way that even in the regions of greater relative movement no contact is given at least on one of the two frontal areas of the axial friction bearing mold element or of the axial pressure disk with the connection elements.
With regard to the installation situation of the axial friction bearing in essence two different relative positions are distinguished. A first position is characterized by the arrangement in the region of the journal root and a second one in the region of the journal frontal area. Depending on these arrangement possibilities differing development possibilities of the solution attempts also result. In the process symmetrical designs, in particular rotationally symmetrical, and non-symmetrical are distinguished. This applies both for the first solution attempt as well as for the second solution attempt.
In the simplest case in accordance with the first solution attempt the axial friction bearing mold element is designed as an annular or disk-shaped element, wherein said element exhibits a first frontal area forming a plane surface and a second frontal area, on which elevations for the formation of the support regions are provided. In the process a design as an annular element is used, in particular in the case of the arrangement of the axial friction bearing in the region of the journal root. Preferably the annular or disk-shaped element is in the process developed in such a way that it is designed rotationally symmetrically with regard to two axes perpendicular to each other. With this two support regions and two inactive regions result on the axial friction bearing mold element, wherein in this case the axial friction bearing mold element can be used regardless of the rotational direction of the universal joint arrangement, i.e. is designed for both rotational directions. The support regions for slight elastic spring deflection in the case of small relative movement are in the process arranged in essence in the region of a plane, which is characterized by the respective journal axis and the joint axis and extend proceeding from this plane on both sides over a sub-region in circumferential direction of the journal. The material recesses, i.e. the regions of lower cross-section are in the process arranged in the areas of the highest or greatest relative movement. High loads of the connection elements are intended to be eliminated through the solution in accordance with the invention. The regions of the greatest relative movement are in the process characterized by an angular range in the journal cross-section, proceeding from a plane that can be described as perpendicular to the joint axis through the journal axis, from said axis in circumferential direction of the journal in both directions in each case in an angular range of 45°<α<60°, preferably α˜60°. The ranges of greater relative movement of the bearing connection elements hence extend in an angular range on both sides of a plane of symmetry through the journal axis and the joint axis. The regions in the region of the plane, which is clamped by the joint axis and the journal axis or lying on both sides of it, are termed as the regions of lower relative movement. Their location is characterized by the describable plane arranged through the journal axis and the joint axis and extends on both sides proceeding from it in circumferential direction of the journal or the bore of the joint yoke.
Regarding the cross-sectional shaping of the axial friction bearing mold element itself there are no restrictions whatsoever. Decisive is only the fact that a material removal is provided here in the high-load regions in the case of conventional solutions.
For the designs with arrangement of the axial friction bearing mold element in the region of the journal frontal area a number of geometries are also conceivable. The element can be designed symmetrically here also. However, a shape deviating from the symmetrical design is also conceivable. However, in any event it is to be ensured that a fixing of location takes place in circumferential direction. This can be realized by form closure or adhesion force. In the case of a form fit design the axial friction bearing mold element is centered in a recess on the journal frontal area, the joint yoke, a cover element or the floor of a radial bearing bushing. Here too preferably one frontal area is always plane and the other second frontal area is characterized by an elevation. The one frontal area in the process rests plane against one of the connection elements, while the other one rests only in the support region on the connection element. The elevation region extends in the process preferably over the entire element in the direction of depth, i.e. as it were on a plane which is characterized by the journal axis and the joint axis over the entire journal frontal area. The elevation itself can be designed in this direction as a constant cross-section or with cross-sectional changes. In the process emphasis is placed here also on a symmetrical design in installation position parallel to the joint axis in order to guarantee the free exchangeability and the independence with regard to the rotational direction in the case of installation. In the view in the direction of the journal axis concave or convex or other type cross-sectional contours result over the direction of extension viewed on the plane which can be described by the journal and joint axis in installation position.
The axial bearing mold element exhibits for an arrangement in the region of the journal frontal area a plane frontal area and a second frontal area at which the support region is arranged. The base geometry, i.e. the geometry of the plane frontal area is preferably determined by a circular contour, however any other geometry is also conceivable. In the case of deviation from the circular contour the lateral surfaces could be used as centering surfaces, if corresponding complementary recesses or contact surfaces for the centering surfaces are provided on the connection elements, in particular of the journal frontal area. The elevation itself is preferably designed symmetrically in relation to the plane through the joint and respective journal axis and extends along said axis over the entire dimension of the axial friction bearing mold element in this direction.
Preferably the height of the elevation along the plane of journal axis and joint axis and perpendicular thereto is constant. However soft or rounded (or inclined designed) transitions to the regions free from the elevation are also conceivable.
Preferably the external geometry of the individual axial friction bearing mold elements is selected in such a way that said geometry corresponds to the connection elements with regard to contour and dimensioning at least at the flat circular frontal area. In particular this means that preferably the axial friction bearing mold element is designed with the diameter which corresponds either in the case of arrangement on the journal root to the external diameter of the external ring of the radial bearing or in the case of arrangement on the journal frontal area with the diameter which corresponds to the journal diameter. Other designs are conceivable. However, preferably the greatest possible dimension regions are always selected for areal resting of the plane frontal area, in order to guarantee an optimum load bearing performance.
BRIEF DESCRIPTION OF THE DRAWINGS.
The solution according to the invention will be explained in the following with the help of figures. The figures show the following:
FIG. 1 illustrates the effects of deformation and axial distortion of journal cross and joint yoke under load in the design of bearing bushing with convention (plane) axial pressure disk (thrust washer);
FIGS. 2 and 2 a illustrate with the help of an axial section through a universal joint arrangement an arrangement of an axial friction bearing mold element according to the invention in accordance with the first solution attempt in the region of the journal root;
FIGS. 3 a through 3 c illustrate a possible design of an axial friction bearing mold element according to FIG. 2 ;
FIG. 4 illustrates an arrangement of an axial friction bearing mold element in the region of the journal frontal area for support on this and on a bearing bushing;
FIGS. 5 a through 5 c illustrate possible geometry developments of the axial friction bearing mold element in the region of the elevation;
FIGS. 6 a , 6 b 1 , 6 b 2 and 6 b 3 illustrates an alternative design to FIG. 4 ;
FIGS. 7 and 8 illustrate a possible development of an axial friction bearing mold element for direct support on the joint yoke or a bearing cover;
FIG. 9 illustrates a first design in accordance with the second solution attempt;
FIG. 10 illustrates a second design in accordance with the second solution attempt.
DETAILED DESCRIPTION
FIG. 1 illustrates in greatly exaggerated representation of the deformations of the components in a prior art universal joint system 1 ′, the problem underlying the solution according to the invention of the effect of relative movements in axial direction of the journal on the bearing system of a journal cross 3 ′ of a joint yoke 6 ′ with the help of a section from an axial section through the journal cross 3 ′. Represented in exemplary fashion is a journal 4 ′ having an axis Z 4 ′, which is supported by bearings via a bearing system 10 ′ in a joint yoke half 6 . 1 ′. Further recognizable is a bearing part 8 ′ of the joint yoke half 6 . 1 ′. The bearing system 10 ′ comprises a radial bearing 13 ′. In the represented case the inner bearing track of the anti-friction elements 15 ′ of the radial bearing 13 ′ is formed by the generated surface 16 ′ of the journal 4 ′. The exterior bearing surface is formed by a bearing bushing 45 ′. In the case of torque transfer the circumferential force causes an uneven load of the radial bearing 13 ′, i.e. in the direction of the circumferential force very high edge stresses and on the opposing side a play between the anti-friction elements 15 ′ and the connection elements bearing bushing 45 ′ or journal 4 ′. This applies in analogy also for the represented axial friction bearing 46 ′ designed as two-sided plane thrust washer, which in accordance with the design of FIG. 1 is arranged for example between journal front side 36 ′ and the inner circumference of the bearing bushing 45 ′.
Through the spring deflection of the journal cross in the radial bearing great relative movements arise in axial direction of the journal, which in the case of form fit installation position generate high compressive forces on the axial friction bearing mold element 46 ′ plane on both sides and the bushing floor. High loads result from this, in particular in the notch regions of the bearing bushing.
It can be recognized that the axial friction bearing 46 ′ in the case of arrangement on the journal front side 36 ′ viewed in the direction of the circumferential force in the region of a plane of the axial section through the universal joint arrangement does not support, while the opposing region is subject to very high compressive forces.
FIGS. 2 and 2 a illustrate in schematically simplified representation with the help of a segment from an axial section (this segment divided at the midpoint of axis Z 4,5 into FIGS. 2 and 2 a ) through a universal joint arrangement 1 the integration of an axial bearing 17 shaped in accordance with the invention. The universal joint arrangement 1 comprises for this purpose a journal cross 3 , which is supported by bearings with its four journals offset from each other by 90° , here by way of example only 4 and 5 (shown in FIG. 2 a ) in one joint yoke 6 . The joint yoke 6 is for this purpose designed in one piece or two pieces depending on the design of the bearing support structures. The separation takes place in the process preferably centrally in a plane of symmetry perpendicular to the axis of the bearing bores in the flange part 7 , wherein the individual joint yoke halves 6 . 1 and lying opposite here 6 . 2 (shown in FIG. 2 a ) are then characterized by a flange part 7 . 1 and 7 . 2 (shown in FIG. 2 a ) and each joint yoke half 6 . 1 and 6 . 2 comprises a bearing support structure. The bearing support structures 8 and 9 (shown in FIG. 2 a ) may have bearing bores, represented here by way of example in the form of a blind hole or pocket hole bore 12 for the joint yoke half 6 . 1 , in particular for the bearing support structure 8 .
The joint yoke arranged offset by 90 ° and the journals supported by bearings within are not shown. The only bearing system 10 comprises in the process a radial bearing 13 . This is preferably designed as an anti-friction bearing, wherein the outer bearing surface is formed by way of example for the anti-friction elements 15 by a retaining ring 14 . The inner bearing surface for the anti-friction elements 15 is formed for example by the generated surface 16 of the journal 4 supported by bearings in the bearing support construction 8 . In addition the bearing system comprises an axial bearing 17 which comprises in accordance with the invention an axial mold friction bearing element 2 . This is arranged in accordance with FIG. 2 in the region of the journal root 18 of the journal 4 . In the process the axial mold friction bearing element 2 forms with the connection elements 21 , 22 friction pairings 20 . 1 and 20 . 2 . In the process the individual friction surfaces on the connection elements 21 , 22 are formed by the retaining ring 14 of the axial bearing 17 and a bearing flange 23 . The axial mold friction bearing 2 supports itself in the process on the bearing flange 23 , which in turn supports itself on the journal cross 3 , in particular the journal root 18 . In the process in the represented case the frontal area facing in the direction to the joint axis G of the retaining ring 14 of the radial bearing 13 forms a friction surface and the axial friction bearing form element 2 forms the additional friction surface of the friction pairing 20 . 1 . Further a second friction pairing 20 . 2 is provided here, which is formed out of the axial mold friction bearing element 2 and the bearing flange 23 .
The concrete design of the axial mold friction bearing element 2 is reproduced in FIG. 3 . FIG. 3 a illustrates in the process a perspective view, while FIG. 3 b reproduces in schematically simplified representation a view from above and FIG. 3 c reproduces a view from the front. The design of the axial mold friction bearing element 2 shown in FIGS. 3 a through 3 c is exemplary. Said element is designed as annular element 28 , which is characterized by a special shaping, in which case the elastic deformations only occur in the region of small relative movements. As a result of the significantly higher flexibility no high distortions arise. In the regions with great relative movements distortions are prevented by material recesses. Plastics are used as material, in particular elastomers which are characterized by a modulus of elasticity in the range of 5000 to 20000 N/mm 2 , preferably 5000 to 10000 N/mm 2 . The axial mold friction bearing 2 is characterized by at least two regions of differently designed out cross-sections. Preferably the arrangement takes place in such a way that the regions of different cross-sections viewed in installation position symmetrically related to the journal axis, which coincides with the center axis M of the annular element 28 , are arranged so that in installation position in a universal joint arrangement the function is guaranteed regardless of the rotational direction of the universal joint arrangement. FIGS. 3 a through 3 c illustrate in the process an axial mold friction bearing element 2 that can be used in such a way for normal operation and reversing operation. For this purpose said element exhibits related to a first line of symmetry S D extending through the theoretical center point M on a plane through the joint and respective journal axis. For this purpose two symmetrical regions 29 and 30 are arranged, which form in the case of low relative movement of the connection elements form adapting load bearing regions or support regions of the axial bearing in loaded state under the effect of circumferential force. These support regions 29 and 30 are designed identically with regard to the choice of their cross-section and form on the basis of their geometry regions with elevation compared to the remaining cross-sectional regions. The development of the support regions 29 , 30 exhibits a symmetrical structure in addition to a line of symmetry S DS aligned perpendicular to the line of symmetry S D and running through the center point M.
The regions 31 and 32 form recesses and are characterized by smaller cross-sectional dimensions than the support regions. The recesses extend uniformly in circumferential direction of the annular element 28 proceeding from the line of symmetry S DS over a region α. Outside of the angle α in circumferential direction the transition to the regions 29 and 30 occurs proceeding from the line of symmetry S DS , said regions only experiencing a slight compressive stress in the case of spring deflection. The support regions 29 and 30 are in the process always active and characterized by a cross-sectional reinforcement in elevation direction. The inactive regions 31 , 32 are allocated in installation position to the regions with great relative movements and still exhibit a play even under high operational load. The installation in the universal joint arrangement in accordance with FIG. 2 takes place now in such a way that the support regions 29 and 30 are arranged on a plane through S D , the regions 32 and 31 on the plane through S DS .
The spring deflection of the journal cross 3 in the radial bearing 13 causes an uneven distribution of force in the axial bearing 17 , wherein in the design as an anti-friction bearing only a fraction of the theoretical load bearing capacity can be used. The lacking plane parallelism of the axial bearing surfaces results in a premature fatigue or wear and tear. On the other hand however the assured dynamic and static load capacities are only guaranteed in a rigid bearing connection design. In order in spite of this to compensate the occurring relative movements between axial bearing 17 and bearing connection elements, the axial mold friction bearing 17 is integrated into the universal joint arrangement in such a way that on the basis of the existing differing cross-sections in circumferential direction an areal resting against the frontal area of the radial bearing shell is only given in the regions of low relative movement. The solution according to the invention is in the process characterized by the fact that the axial mold friction bearing 2 under load enables a partial elastic form closure with the elevation regions. In the regions in which the relative movements are small, a soft spring deflection is enabled, while in the regions with great relative movement free travels are provided which even under load are not completely exhausted, i.e., the recesses guarantee axial relative movements between joint yoke G and journal cross without buildup of elastic deformations in the bearing components. The transition between the regions of differing cross-sectional geometry and/or dimensions takes place in the process either continuously or in stages.
In the region of the elevations the only slight relative movements cause elastic deformations of the axial friction bearing mold elements, the material recesses on the axial friction bearing mold element enable great, contact-free relative movements. Through the choice of a plastic, in particular elastomers, with a modulus of elasticity of 5,000-10,000 N/mm 2 only slight distortion forces or compressive stresses arise in the axial bearing.
The axial bearing 17 in accordance with FIG. 3 a, b , in particular the axial friction bearing mold element 2 , is installed in the universal joint arrangement according to FIG. 2 in the manner that the support regions 29 and 30 extend in an angular range between 30 ° and 45 ° , preferably ca. 30 °, from a plane determined by the joint axis G and the respective journal axis through the axis of symmetry S D . The elevation region is preferably given only in one direction, i.e. on one plane frontal area 20 , so that on the opposing plane frontal area 24 an areal resting over the entire circumference against the connection element 22 , here the bearing flange 23 , is given.
FIG. 4 illustrates an additional possible arrangement of an axial bearing 417 and a universal joint arrangement 401 . In the case of this design the arrangement takes place on the front side 436 of the journal 404 supported by bearings in the corresponding joint yoke 406 . FIG. 4 represents in the process a first possible embodiment in which the connection element 421 is formed by a bearing bushing 445 , while the other bearing connection element 422 is formed by the journal 404 . The axial friction bearing 419 is arranged here between the retaining ring 414 of the radial bearing 413 and the frontal area 436 of the journal 404 . The friction pairings 420 . 1 , 420 . 2 are also formed between these elements. For this purpose the axial mold friction bearing element 402 is designed as an annular or disk-shaped element, wherein the shape of a disk is preferred. The disk is designed circular with regard to the geometry on the outer circumference and comprises a non-rotationally symmetrical support region. Viewed in axial section this region extends over a width B in the form of a projection 438 , which rests free of play. The alignment of the support region 437 formed by the projection 438 occurs in the process also here preferably again on both sides to the line of symmetry S D on the plane through the journal axis Z 4,5 and the joint axis G. The corresponding material recess is located in the process on the frontal area 439 of the axial friction bearing mold element 417 facing the journal cross. The support region 437 in the form of the projection 438 is not designed rotationally symmetrically, but rather extends with a width B over a predefined length I, preferably the entire extent of the axial friction bearing mold element 402 along the line of symmetry S D . The represented elevation in the support region 437 can be limited by plane or curved areas of contact perpendicular to the axial direction. Possible designs are reproduced in greatly simplified representation for a view of the bottom on the axial friction bearing mold element 402 in the direction of the journal axis in accordance with FIG. 4 in FIGS. 5 a through 5 c . These show views of the bearing frontal area with the support region 537 a , 537 b , and 537 c of the axial friction bearing mold element 502 a , 502 b , and 502 c . From this it can be seen that the support region 537 a , 537 b , and 537 c extends over the entire dimension parallel to the line of symmetry S D . In the process FIG. 5 a illustrates a design with constant width B of the projection 538 a along or on both sides of the axis of symmetry S D , i.e. parallel frontal areas of the projection, while FIG. 5 b reproduces a development with concave and FIG. 5 c shows a development with convex geometry related to the expansion along the line of symmetry S D .
FIG. 6 a illustrates a design of the axial friction bearing mold element 602 in which the material recess is located on the frontal area of the journal 604 in installation position facing the bushing bottom. The bushing bottom 640 forms in the process a first friction surface for the axial mold friction bearing element 602 , while the second friction surface of the friction pairing 620 . 1 is formed here by the frontal area 641 of the axial friction bearing mold element 602 . This applies in analogy for the friction pairing 620 . 2 , which is provided between the axial friction bearing mold element 602 and the front side 636 of the journal 604 . In the process preferably the axial friction bearing mold element 602 is also arranged for the purpose of its centering in a corresponding recess on the front side 636 of the journal 604 . Preferably however it is not a matter of a cylindrical bore here, but rather a groove 644 , which simultaneously assumes the centering function for the axial friction bearing mold element 602 , i.e. locally fixes the location of the axial friction bearing mold element 602 in the direction of the circumferential force. The width of the groove and with it the extent of the axial friction bearing mold element 602 on the plane perpendicular to the rotational axis of the joint through the journal axis amounts to about the half of the journal diameter. With it in the region of the great axial relative movements corresponding free spaces result between journal frontal area 636 and bushing bottom 640 . The axial friction bearing mold element 602 a , 602 b , or 602 c is for this purpose by way of example as in FIGS. 6 b 1 , 6 b 2 represented as a plate-shaped element which by way of example possesses a rectangular base geometry and which exhibits an elevation region 637 a 637 b , or 637 c on its front sides which in installation position forms a first support region. According to FIG. 6 b 3 the groove for centering of the location of the axial friction bearing mold element 602 c runs parallel to the line of symmetry S D . As already stated, a circular or cylindrical development of the axial friction bearing mold element 602 is also conceivable, wherein in this case other means for location fixing would be provided. The arrangement occurs in the process free of play between the journal 604 and the bushing bottom 640 , wherein corresponding to the relative movements only a slight spring deflection takes place on the basis of the geometric development in the region of the frontal area 641 of the axial friction bearing mold element 602 . The designs shown in FIGS. 6 b 1 through 6 b 3 are exemplary. A development of the elevation region as shown in FIGS. 5 a through 5 c is also conceivable.
FIG. 7 illustrates on the other hand an alternative design according to FIG. 6 with the design of the axial bearing in a blind hole in the case of direct support on the journal yoke half 706 . The axial bearing 717 is hence arranged here directly between the joint yoke 706 and journal 704 . Regarding the design there are again also several possibilities. Preferably the axial friction bearing mold element 702 is designed as a cylindrical disk, wherein said disk is designed in the center region, i.e. on both sides of the line of symmetry S D , with a corresponding elevation. This can extend over a sub-region of the radial extent of the disk element or, as shown here, preferably over the entire dimension parallel or inclined or curved compared to the line of symmetry S D . The support region 737 is in the process directed to the joint yoke 706 . The opposing plane front side rests areal against the frontal area 736 of the journal 704 . The regions 731 , 732 free from the elevation are arranged in the regions of greater relative movement. This, in particular the front side of the axial friction bearing mold element 702 bearing the elevation, forms a free space with the joint yoke G in the process in the regions of great relative movement. The elevation or support region 737 can be designed cylindrical or by way of example corresponding to the designs in FIGS. 5 a through 5 c.
In contrast FIG. 8 illustrates a development of the axial friction bearing mold element 802 with support between journal front side 836 and the bottom of the yoke bore 849 or a differently developed bottom, for example in the form of a bearing cover, wherein here the support region 837 is directed to the front side 836 of the journal 804 and supports itself on it.
In FIGS. 7 and 8 the axial friction bearing mold element 702 or 802 is designed disk-shaped or annular, wherein the disk-shaped or annular element comprises a first front side characterized by a plane surface and the support region 737 or 837 provided for elastic spring deflection is designed on the second opposing frontal area. The support region 737 or 837 resting free of play on the connection element in all function states is in this case not rotationally symmetrical, but rather is designed for example similar to the representations described in FIGS. 5 a through 5 c . It is also conceivable to design the support regions 737 , 738 , 837 , or 838 not in one piece, but rather segmented.
If FIGS. 1 through 8 illustrate designs with separate axial friction bearing mold element 2 , this function can in accordance with FIGS. 9 and 10 in accordance with a second solution attempt be assumed by the connection elements joint yoke 906 , journal 904 , 905 and/or bearing bushing, i.e. the function of the axial friction bearing mold element 2 is then executed directly by these elements.
In accordance with FIG. 9 the axial bearing 917 comprises an axial bearing pressure disk 946 as in the case of designs according to the state of the art, preferably with plane front side 947 , 948 on both sides. The function of the axial friction bearing mold element is assumed in accordance with FIG. 9 by way of example by the bearing bushing 945 , in particular the bushing bottom 940 . An assumption of function by the joint yoke 906 in particular the closed bearing bore 949 is also conceivable.
The support region 950 in the form of the elevation 951 is in the process correspondingly incorporated in the bushing bottom 940 . Preferably this takes place by removal of material for example grinding. Regarding the design of the elevation 951 a multitude of possibilities exists with the restriction that as a result of the rotation of the bearing bushing in operation a rotationally symmetrical shaping is to be selected. Decisive is the fact that only the center region of the bushing bottom 940 is active by elevation as a support region 950 and the outer regions of the bushing bottom 940 form free spaces to the journal front side 936 . These free spaces enable relative movements without causing axial distortions on the connection elements.
FIG. 10 illustrates an addition design in integral style on the journal 1004 , in particular the frontal area 1036 . Here the support region 1050 is formed by an elevation region 1051 , which is designed in installation position with its axis of symmetry SD parallel to the joint axis G. These support regions can be formed by one surface or a multitude of individual segment-type surface regions, designed spaced apart from one another.
The support takes place directly or via an axial bearing pressure disk 1046 as in the case of the designs according to the state of the art.
The design of the elevation region 1051 on the journal frontal area can also take place variably. In the simplest case in turn by corresponding material removal. Regarding the geometrical development there are also a multitude of possibilities. These can be designed viewed in cross-section rounded or with sharp edges. Further they can be designed rotationally symmetrical in a view from above with regard to the journal axis or with regard to an axis perpendicular to the journal axis running parallel to the joint axis.
Reference List
1 Universal joint arrangement 2 Axial friction bearing mold element 3 Journal cross 4 , 5 Journal 6 Joint yoke 6 . 1 , 6 . 2 Joint yoke half 7 Flange part 8 , 9 Bearing part 10 , 11 Bearing system 12 Bearing bore 13 Radial bearing 14 Retaining ring 15 Anti-friction element 16 Generated surface of the journal 17 Axial bearing 18 Journal root 19 Axial friction bearing 20 Frontal area 20 . 1 , 20 . 2 Friction pairing 21 Connection element exterior 22 Connection element interior 23 Bearing flange 24 Frontal area 25 Friction pairing 26 Centering device 27 Seal retainer 28 Annular element 29 Support region 30 Support region 31 Region recess 32 Region recess 33 1 st frontal area axial bearing mold element 34 2 nd frontal area axial bearing mold element 35 Surface 36 Front side 37 Support region 38 Cone, projection 39 Front side 40 Bushing bottom 41 Front side 42 Friction pairing 43 Journal bore 44 Groove 45 Bearing bushing 46 Axial bearing pressure disk as thrust washer 47 Front side 48 Front side 49 Bearing bore 50 Support region 51 Elevation S DS Line of symmetry S D Line of symmetry a Distance from the axis of symmetry in circumferential direction Z 4,5 Journal axis G Rotational axis of the joint shaft α Angle of circumference recess B Width of the support region b Thickness of the axial friction bearing mold element h Height of the support region of the axial friction bearing mold element
ΔS Height difference between support region and recessed region of axial friction bearing mold element | A universal joint arrangement with a journal cross, supported by bearings in two joint yokes offset to one another by 90°. Each joint yoke comprises a flange and two bearings. Each bearing has an axial bearing mold element that is supported by a connection element on the joint yoke and at least indirectly on the journal cross to form a first and second friction pairing. The mold element has a planar face and a second face having at least one elevated support region facing the first or second friction pairing, and is arranged with the support region on the connection element, which elastically deflects under load. The regions on the second face other than the support region are free from contact with the connection element in every load state. The support region is arranged in the region of low relative movement of the connection element with the journal cross, while the regions other than the support region lie in the region of greatest relative motion. | 5 |
FIELD OF THE INVENTION
The present invention relates to a network simulation for testing network performance. In particular, the present invention relates to bulk call generation and application emulation for purposes of testing and simulation for evaluating the performance of a network.
BACKGROUND OF THE INVENTION
A computer network includes a set of communication channels interconnecting a set of computing devices or nodes that can communicate with each other. These nodes may be computers, terminals, workstations, or communication units of various kinds distributed over different locations. They communicate over communications channels that can be leased from common carriers (e.g. telephone companies) or are provided by the owners of the network. These channels may use a variety of transmission media, including optical fibers, coaxial cable, twisted copper pairs, satellite links, or digital microwave radio. The nodes may be distributed over a wide area (distances of hundreds or thousands of miles) or over a local area (distances of a hundred feet to several miles), in which case the networks are called wide area (WAN) or local area (LAN) networks, respectively. Combinations of LANs and WANs are also possible in the case of widely separated LANs in branch offices located via a WAN to the LAN in corporate headquarters.
Recently, modem computer networks have greatly increased in number and geographical area, in the number and variety of devices interconnected, and in the scope of applications supported. A modem network may consist of thousands of computing devices made by various manufacturers connected by a variety of transmission media spanning international and intercontinental boundaries.
FIG. 1 is a block diagram illustrating interactions between users and a network. FIG. 1 shows users 100 A- 100 C who are attempting to make calls to various Internet protocol addresses in the network 106 . Users 100 A- 100 C may be any entity attempting to access network 106 , such as an individual user, a server, or a corporation. Users 100 A- 100 C typically call into a central office, such as Pacific Bell, which in turn calls an Internet service provider 104 , such as Netcom. The call typically terminates with an Internet service provider 104 . A router then typically uses a network protocol connection, such as a transmission control protocol/Internet protocol (TCP/IP), to distribute the calls made by the users 100 A- 100 C to the appropriate Internet protocol (IP) addresses in the network 106 .
For testing and simulation purposes, it is often useful to simulate users 100 A- 100 C and the central office 102 to determine the quality and performance of the network 106 . For instance, it may be useful for the Internet service provider 104 to determine how many number of calls it can handle within a given amount of time. With that information, the Internet service provider 104 could determine whether its infrastructure is adequate to provide services for its customers. Another instance in which testing and simulation may be required is if a customer does not wish to build its own network, but contracts for a service agreement to utilize someone else's private network. Typically, these service level agreements agree to provide availability for a certain percent of time. In order to monitor the contracts, simulations can occur which mimics the customers' access to provide proof that the network can simultaneously handle a given number of calls and that the agreed percentage of availability is actually being provided.
FIG. 2 shows a block diagram of a system for testing a network. FIG. 2 shows a bulk call generator 200 , such as the bulk call generator manufactured by Abacus, making calls to the network 106 . The bulk call generator 200 simulates the users 100 A- 100 C and the central office 102 of FIG. 1 by generating a large number of calls into the network 106 . The bulk call generator 200 typically generates a large number of calls into the network 106 to be rerouted back to the bulk call generator 200 . In other words, the bulk call generator 200 makes a large number of calls to itself through the network 106 . In this manner, the bulk call generator 200 simulates the users 100 A- 100 C and the central office 102 of FIG. 1 to test the performance of the network 106 . These conventional bulk call generators 200 are typically a device with dedicated hardware specifically designed to create bulk calls. The conventional bulk call generators 200 typically range in price from $100,000 to $500,000.
Although simulation and testing can be accomplished with conventional bulk call generators, they tend to be extremely expensive. Additionally, conventional bulk call generators typically do not include a variety of IP addresses as part of the test scenario.
It would be desirable to have a bulk call generator which does not require dedicated hardware, which can be manufactured at a reasonable price, and which includes a variety of IP addresses as part of the test scenario. The present invention addresses such a need.
SUMMARY OF THE INVENTION
The present invention is a system and method for generating bulk calls and emulating applications. According to an embodiment of the present invention, a router is converted into a bulk call generator which generates packets with Internet protocol (IP) addresses for the purpose of simulating network traffic. These packets may be initially either captured or created. When the packets are captured, they may be captured from actual network traffic and rerouted to various selected IP addresses which are used for simulation purposes. Alternatively, when the packets are created, they may be created within the converted router and various selected IP addresses, reserved for simulation purposes, are assigned to the packets. The various selected IP addresses may be in a range which is user configurable. The IP addresses may be selected from this range by any method, such as incrementation, decrementation, or random selection. Connections may be set up according to a routing table based on the IP addresses of the various data packets.
According to an embodiment of the present invention, a set of parameters is assigned to each data packet. Examples of parameters include an interface assignment, packet issuance rate, duration for the rate, number of times to repeat this set of parameters, and a modification scheme for modifying the IP address. A send engine in the converted router may receive the set of parameters and send the data packet according to the instructions in the set of parameters associated with the data packet.
A method according to an embodiment of the present invention for generating a plurality of calls to a network is presented. The method comprising a step of providing a data packet with an address, wherein the address identifies a location within a network, the device being configurable to perform as a router. The method also comprising providing a record with at least one traffic parameter; and sending the data packet to the network for a simulation purpose, the data packet being sent according to the at least one traffic parameter.
A system according to an embodiment of the present invention for generating a plurality of calls to a network is also presented. The system comprising a packet generator subsystem included in a device, wherein the device is configurable to perform as a router, and wherein the packet generator subsystem provides a data packet with an address, wherein the address identifies a location within a network. The system also comprising a dial shelf coupled to the packet generator subsystem, wherein the packet generator subsystem is configured to request the dial shelf to prepare to send a predetermined number of calls for a simulation purpose.
Another system according to an embodiment of the present invention for generating a plurality of calls to a network is presented. The system comprising a means for providing a data packet with an address, wherein the address identifies a location within a network, the device being configurable to perform as a router. The system also comprising a means for providing a record with at least one traffic parameter; and a means for sending the data packet to the network for a simulation purpose, the data packet being sent according to the at least one traffic parameter.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of users accessing a network.
FIG. 2 is a block diagram of a network simulation.
FIG. 3 is a block diagram of a network simulation according to an embodiment of the present invention.
FIG. 4 is a block diagram of a system according to an embodiment of the present invention for generating bulk calls and emulating applications.
FIG. 5 is a flow diagram of a method according to an embodiment of the present invention for generating bulk calls and emulating applications.
FIG. 6 is a block diagram illustrating a packet generator subsystem's interactions with data packets according to an embodiment of the present invention.
FIG. 7 is a block diagram of a packet generator subsystem according to an embodiment of the present invention.
FIG. 8 is a flow diagram of a method performed by a packet engine according to an embodiment of the present invention.
FIG. 9 is a flow diagram of a method performed by the sender engine according to an embodiment of the present invention.
FIG. 10 is a flow diagram of the send engine following parameters of a packet record, according to an embodiment of the present invention.
FIG. 11 is a flow diagram of a determination of a drop rate according to an embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following description is presented to enable one of ordinary skill in the art to make and to use the invention and is provided in the context of a patent application and its requirements. Various modifications to the preferred embodiments will be readily apparent to those skilled in the art and the generic principles herein may be applied to other embodiments. Thus, the present invention is not intended to be limited to the embodiment shown but is to be accorded the widest scope consistent with the principles and features described herein.
FIG. 3 is a block diagram of a system according to an embodiment of the present invention for testing the performance of a network. FIG. 3 includes a router call generator 300 which simulates calls and emulates applications to a receiving router 302 . The router call generator 300 may also send calls to an Internet service provider such as that shown in FIG. 1 . In this example, a receiving router receives the router call generator's calls and disseminates them to various Internet protocol (IP) addresses in the network 304 . The router call generator 300 may be a conventional router that is suitable for implementation of the present invention. Examples of such a router suitable for implementation of the present invention include Cisco 5800 series router, and Cisco 5300 series router, both manufactured by Cisco Systems, Incorporated.
One advantage of utilizing a conventional router to implement the present invention is that the cost of converting such a router is substantially less than buying a device with dedicated hardware which can range from $100,000 to $500,000. Since a suitable router can simply be loaded with a new program to implement the present invention, the cost of testing a network according to embodiments of the present invention should be substantially less than the cost of testing the network with a conventional bulk call generator. Another advantage of the system and method according the present invention is that an embodiment of the present invention calls various IP addresses of the network 304 . The present invention facilitates simulation with data with different sizes and patterns which may cause problems for a receiving router. Applications may be emulated by sending data packets that resemble real traffic. Accordingly, a more realistic simulation of network performance can be evaluated.
FIG. 4 is a block diagram of a system according to an embodiment of the present invention for generating bulk calls and emulating applications. FIG. 4 shows a simplified block diagram of the router call generator 300 shown in FIG. 3 . The router call generator 300 is shown to include a router shelf 402 coupled with a dial shelf 404 . The router shelf 402 includes a router operating system 403 which in turn includes a packet generator subsystem 406 . The dial shelf 404 includes communication cards, such as T1/E1 trunk cards 410 and modem cards 408 . T1 refers to T1 communication lines, and E1 refers to communication lines used in Europe which are equivalent to T1 communication lines. Alternatively, the trunk cards 410 may be configured to be utilized with other communication lines, such as T3 communication lines. The T1/E1 trunk cards 410 generates digital calls, while the modem cards 408 generate analog calls.
The dial shelf 404 is also shown to include a plurality of T1 ports 412 . These ports 412 are configured to be coupled to communication lines, such as T1, E1, or T3. Accordingly, digital calls generated via the trunk cards 410 are transmitted through the communication ports 412 . Digital versions of the analog calls generated by modem cards 408 are also transmitted through the communication ports 412 .
FIG. 5 is a flow diagram of a method according to an embodiment of the present invention for generating bulk calls and emulating applications. It is first assumed that a user wishes to simulate N users calling into the network, via step 500 . The packet generator subsystem ( 406 of FIG. 4) informs the dial shelf 404 to set up N calls, via step 502 . The dial shelf 404 sets call set up, via step 504 . When the dial shelf 404 sets call set up, calls are setup with appropriate negotiations, such as use of tones. Dial shelf 404 then informs the packet generator subsystem 406 that N calls have been set up, via step 506 . Note that the dial shelf 404 may inform the packet generator subsystem 406 that N-X calls have been set up wherein X is the number of calls which were requested but failed to be set up. For this example, it is assumed that all N requested calls have been set up.
The packet generator subsystem 406 then informs the dial shelf 404 to transmit data, via step 508 . A receiver for the network, such as a receiving router, receives the N calls and verifies that the N calls have been received, via step 510 . The user, or an automated script, then informs the packet generator subsystem 406 to tear down (disconnect) the calls, via step 512 .
FIG. 6 illustrates interactions between the packet generator subsystem and data packets. As data packets enter the router, it passes by the packet generator subsystem 406 prior to being evaluated by the router operating system 403 . The packet generator subsystem 406 can perform a filtering function such that if a given data packet meets a predetermined criteria, the packet generator subsystem 406 may capture the data packets which meet these criterias. Accordingly, the data packets which meet the predetermined filtering criteria are not received by the router operating system 403 . An example of a predetermined filtering criteria include a predetermined series of IP addresses. If a data packet passes by the packet generator subsystem 406 with an IP address which fits into one of the predetermined sets of IP addresses, then the packet generator subsystem 406 will capture that data packet.
FIG. 7 is a block diagram of the packet generator subsystem 406 . The packet generator subsystem 406 includes a send engine 700 , and a packet engine 702 . The packet engine 702 includes a set of records 704 A- 704 D which corresponds to one of data packets 706 A- 708 D. The send engine 700 receives the records 704 A- 704 D, preferably in some sequential order, and sends the data packets 706 A- 708 D out according to instructions written in the records 704 A- 704 D. The send engine 700 continues to send the data 706 A- 708 D until it receives a tear down call 706 . Further details of the send engine 700 will later be discussed in conjunction with FIGS. 9 and 10.
FIG. 8 is a flow diagram of a method performed by the packet engine 702 of FIG. 7 for creating and sending packet data and records. Data packets are either created or captured, via step 800 . If a data packet is created, then it is created through well known methods, and an IP address is assigned to the created data packet. If, however, a data packet is captured, then it may be captured according to a filtering method, such as the filtering method described in conjunction with FIG. 6 .
A set of records ( 704 A- 704 D) are then created with traffic parameters set for each record, via step 802 . These traffic parameters include selecting an interface for the associated data to be transmitted, such as port 412 of FIG. 4 . The traffic parameters may also include a traffic stream rate, such as one hundred packets per second. The duration for which the rate is to be performed may also be included in the parameters, such as one hundred packets per second for ten minutes. The traffic parameters may also include the number of times to repeat the instructions (traffic parameters) of the current record, and a scheme for modification of IP addresses. For example, the scheme for modification of the data packet IP addresses may include a predetermined set of IP addresses, for instance address 0001 -address 0100 , and a scheme to vary the IP addresses within the predetermined set of IP addresses. For instance, the set of IP addresses may be address 0001 -address 0100 , and an addresses within that predetermined set may be randomly selected, incrementally selected, or decrementally selected.
A pointer from each record to a data packet is then created, via step 804 . Packet records are then sent to the send engine in a predetermined manner, such as sequential order, via step 806 .
FIG. 9 is a flow diagram of a method performed by the send engine 700 of FIG. 7 . The send engine receives a packet record 704 A, via step 900 . The send engine then follows parameters of the packet record, via step 902 . Details of the step of the send engine following the parameters (instructions) of the packet record will later be discussed in conjunction with FIG. 10 .
It is then determined whether the currently evaluated record is the last record, via step 904 . If it is not the last record, then the next packet record is retrieved, via step 906 , and the send engine follows the parameters of the new packet record, via step 902 .
If the currently evaluated record is the last record, via step 904 , then it is determined whether there is an external loop counter, via step 910 . An external loop counter is a variable which indicates whether to repeat the evaluation of the entire set of packet records. If there is no external loop counter, via step 910 , then the send engine is finished, via step 912 . If, however, there is an external loop counter, via step 910 , then the first packet record is again retrieved, via step 918 , and the send engine again follows the parameters of the first packet record, via step 902 .
FIG. 10 is a flow diagram of the send engine following the parameters of the packet record, such as step 902 of FIG. 9 . Variables X, Y, Z, and T are initially predetermined as parameters of the current packet record which is being evaluated. The process starts at step 1000 , and data is sent through X interface, via step 1002 , wherein X indicates a particular interface, such as port 412 of FIG. 4 . Thereafter, Y nanoseconds are allowed to pass after sending the data, via step 1004 , wherein Y indicates a predetermined number of nanoseconds. It is then determined whether Z seconds have expired since start (step 1000 ), via step 1006 . If Z seconds have not yet expired, then the IP address of the data packet associated with the current record is modified according to the record's instructions, via step 1008 , and the data is sent through X interface, via step 1002 .
If Z seconds have expired since start (step 1000 ), via step 1006 , then it is determined whether T is greater than 0, via step 1010 , where T is equal to a number of times to repeat the packet record instructions. If T is not greater than 0, then the send engine is finished following the parameters of the packet records, via step 1012 . If, however, T is greater than 0, via step 1010 , then T is set equal to T−1, via step 1014 , and the process starts again at step 1000 .
FIG. 11 is a flow diagram of a method according to an embodiment of the present invention for determining a drop rate. A drop rate is the maximum rate which the dial shelf 404 of FIG. 4 can transmit data packets. The dial shelf is asked to generate a number of calls and this number is incremented until the dial shelf fails to fulfill the incremented rate. At that point, the drop rate is known. Once the drop rate for a particular bulk call generator is known, the drop rate can again be determined when it is connected to a network. The difference in the drop rate when the bulk call generator is not connected to the network and when the bulk call generator is connected to the network can be attributed to network performance.
In FIG. 11, the dial shelf is requested to generate X packets per second, via step 1100 . The dial shelf is then queried regarding how many packets per second it has generated, via step 1102 . The number of connections the dial shelf was asked to set up is compared with the number of connections the dial shelf actually managed to set up, via step 1104 . It is then determined whether the dial shelf finished all the requested connections, via step 1106 . If the dial shelf did not complete all the requested connections, then the number of connections the dial shelf has completed is considered the drop rate, via step 1108 . If, however, the dial shelf finished all the requested connections, via step 1106 , then X is incremented by a predetermined amount, via step 1110 , and the dial shelf is again requested to generate X packets per second, via step 1100 .
Embodiments of the present invention further relate to computer storage products with a computer readable medium that contain program code for performing various computer-implemented operations. The computer-readable medium is any data storage device that can store data which can thereafter be read by a computer system. The media and program code may be those specially designed and constructed for the purposes of the present invention, or they may be of the kind well known to those of ordinary skill in the computer software arts. Examples of computer-readable media include, but are not limited to, magnetic media such as hard disks, floppy disks, and magnetic tape; optical media such as CD-ROM disks; magneto-optical media such as floptical disks; and specially configured hardware devices such as application-specific integrated circuits (ASICs), programmable logic devices (PLDs), and ROM and RAM devices. The computer-readable medium can also be distributed as a data signal embodied in a carrier wave over a network of coupled computer systems so that the computer-readable code is stored and executed in a distributed fashion. Examples of program code include both machine code, as produced, for example, by a compiler, or files containing higher level code that may be executed using an interpreter.
A method and system for generating bulk calls and emulating applications has been disclosed. Software written according to the present invention may be stored in some form of computer-readable medium, such as memory or CD-ROM, or transmitted over a network, and executed by a processor.
Although the present invention has been described in accordance with the embodiment shown, one of ordinary skill in the art will readily recognize that there could be variations to the embodiment and these variations would be within the spirit and scope of the present invention. Accordingly, many modifications may be made by one of ordinary skill in the art without departing from the spirit and scope of the appended claims. | According to an embodiment of the present invention, a router is converted into a bulk call generator which generates packets with Internet protocol (IP) addresses for the purpose of simulating network traffic. These packets are initially either captured or created. When the packets are captured, they are captured from actual network traffic and rerouted to various selected IP addresses which are used for simulation purposes. Alternatively, when the packets are created, they are created within the converted router and various selected IP addresses, reserved for simulation purposes, are assigned to the packets. The various selected IP addresses may be in a range which is user configurable. The IP addresses may be selected from this range by any method, such as incrementation, decrementation, or random selection. Connections are set up according to a routing table based on the IP addresses of the various data packets. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of International Application No. PCT/CN2012/075408, filed on May 11, 2012, which is hereby incorporated by reference in their entireties.
TECHNICAL FIELD
The present application relates to the field of communications, and in particular, to a method, a device, and a system for reporting a signal quality measurement result.
BACKGROUND
In a wireless mobile communications system, due to movement of a terminal and a change in channel quality, the terminal may autonomously select a cell with better quality; and alternatively, a radio network node on a network side may change the terminal to the cell with better quality.
In a system broadcast message defined by an existing UMTS (universal mobile telecommunications system, universal mobile telecommunications system) standard, how to report a measurement result in an LTE (long term evolution, long term evolution) system is not specified. In this situation, when the network side needs to perform cell redirection on the terminal, as the terminal cannot report an LTE cell signal quality measurement result that serves as reference data for a radio network controller, the terminal redirection success rate of the radio network controller is relatively low.
SUMMARY
A plurality of aspects of the present application provides a method, a device, and a system for reporting a signal quality measurement result, to implement the reporting of the signal quality measurement result by a terminal.
One aspect of the present application provides a method for reporting a signal quality measurement result, including: receiving adjacent frequency information, an adjacent-frequency signal quality reporting amount, and a reporting threshold corresponding to the adjacent-frequency signal quality reporting amount from a radio network node; performing measurement according to the adjacent-frequency information to obtain an adjacent-frequency signal quality measurement result; and reporting the adjacent-frequency signal quality measurement result in a preset bit string format to the radio network node according to the adjacent frequency information, the adjacent-frequency signal quality reporting amount, and the reporting threshold, so that the radio network node obtains the adjacent-frequency signal quality according to the adjacent-frequency signal quality measurement result.
Another aspect of the present application provides a method for reporting a signal quality measurement result, including: sending adjacent frequency information, an adjacent-frequency signal quality reporting amount, and a reporting threshold corresponding to the adjacent-frequency signal quality reporting amount to a terminal; and receiving an adjacent-frequency signal quality measurement result in a preset bit string format from the terminal, so that the radio network node obtains the adjacent-frequency signal quality according to the adjacent-frequency signal quality measurement result.
Another aspect of the present application provides a terminal, including: an information receiver, configured to receive adjacent frequency information, an adjacent-frequency signal quality reporting amount, and a reporting threshold corresponding to the adjacent-frequency signal quality reporting amount delivered by a radio network node; a measurement processor, configured to perform measurement according to the adjacent frequency information to obtain an adjacent-frequency signal quality measurement result; and a sender, configured to report the adjacent-frequency signal quality measurement result in a preset bit string format to the radio network node according to the adjacent frequency information, the adjacent-frequency signal quality reporting amount, and the reporting threshold, so that the radio network node obtains the adjacent-frequency signal quality according to the adjacent-frequency signal quality measurement result.
Another aspect of the present application provides a radio network node, including: a sender, configured to send adjacent frequency information, an adjacent-frequency signal quality reporting amount, and a reporting threshold corresponding to the adjacent-frequency signal quality reporting amount to a terminal; and a receiver, configured to receive an adjacent-frequency signal quality measurement result reported in a preset bit string format by the terminal, so that the radio network node obtains the adjacent-frequency signal quality according to the adjacent-frequency signal quality measurement result.
A system for reporting a signal quality measurement result includes a terminal and/or a radio network node.
Embodiments of the present application provide a method, a device, and a system for reporting a signal quality measurement result to implement reporting of an adjacent-frequency signal quality measurement result by a terminal, so that the radio network node is capable of making, according to the adjacent-frequency signal quality measurement result, a decision for the terminal to change to a cell, thereby increasing the success rate of cell handover, redirection, and cell change.
BRIEF DESCRIPTION OF THE DRAWINGS
To illustrate the technical solutions in the embodiments of the present application or in the prior art more clearly, the following briefly introduces the accompanying drawings required for describing the embodiments or the prior art. Apparently, the accompanying drawings in the following description show merely some embodiments of the present application, and a person of ordinary skill in the art may still derive other drawings from these accompanying drawings without creative efforts.
FIG. 1 is a flowchart of a method for reporting a signal quality measurement result according to an embodiment of the present application;
FIG. 2 is a flowchart of another method for reporting a signal quality measurement result according to another embodiment of the present application;
FIG. 3 is a flowchart of a method for reporting a signal quality measurement result according to another embodiment of the present application;
FIG. 4 is a block diagram of a terminal according to another embodiment of the present application;
FIG. 5 is a block diagram of a radio network node according to another embodiment of the present application;
FIG. 6 is a block diagram of a sender according to another embodiment of the present application; and
FIG. 7 is a schematic diagram of a system for reporting a signal quality measurement result according to another embodiment of the present application.
DETAILED DESCRIPTION
In the following description, to illustrate rather than limit, specific details such as particular system structure, interface, and technology are provided to make a better understanding of the present application. However, it should be understood by a person skilled in the art that the present application may also be implemented in other embodiments without the specific details. In other situations, detail descriptions of well known apparatus, circuit and method are omitted, so that the present application is described without being disturbed by the unnecessary details.
Communications technologies described in this specification are applicable to various communications systems, such as, current 2G and 3G communications systems, and a next-generation communications system, for example, a global system for mobile communications (GSM, Global System for Mobile communications), a code division multiple access (CDMA, Code Division Multiple Access) system, a time division multiple access (TDMA, Time Division Multiple Access) system, a wideband code division multiple access wireless (WCDMA, Wideband Code Division Multiple Access Wireless) system, a frequency division multiple addressing (FDMA, Frequency Division Multiple Addressing) system, an orthogonal frequency-division multiple access (OFDMA, Orthogonal Frequency-Division Multiple Access) system, a single-carrier FDMA (SC-FDMA) system, a general packet radio service (GPRS, General Packet Radio Service) system, a long term evolution (LTE, Long Term Evolution) system, and other communications system of this type.
This specification describes various aspects with reference to a user equipment and/or a base station and/or a base station controller.
The user equipment may be a wireless terminal or a wired terminal. The wireless terminal may be a device providing voice and/or data connectivity for users, a handheld device having a wireless connection function, or another processing device connected to a wireless modem. A wireless terminal may communicate with one or more core networks through a radio access network (such as RAN, Radio Access Network). The wireless terminal may be a mobile terminal, such as a mobile phone (or called a “cellular” phone) or a computer equipped with a mobile terminal. For example, the wireless terminal may be a portable, pocket-sized, handheld, computer-embedded, or vehicle-mounted mobile apparatus, which exchanges voice and/or data with the radio access network. For example, it may be a device such as a personal communication service (PCS, Personal Communication Service) phone, a cordless telephone set, a session initiation protocol (SIP) phone, a wireless local loop (WLL, Wireless Local Loop) station, a personal digital assistant (PDA, Personal Digital Assistant) and the like. The wireless terminal may also be called a system, a subscriber unit (Subscriber Unit), a subscriber station (Subscriber Station), a mobile station (Mobile Station), a mobile station (Mobile), a remote station (Remote Station), an access point (Access Point), a remote terminal (Remote Terminal), an access terminal (Access Terminal), a user terminal (User Terminal), a user agent (User Agent), a user device (User Device), or a user equipment (User Equipment).
The base station (for example, an access point) may be a device in communication with a wireless terminal via one or more sectors over an air interface in an access network. The base station may be used to perform a mutual conversion between a received over-the-air frame and an IP packet and serve as a router between the wireless terminal and a rest portion of the access network, where the rest portion of the access network may include an internet protocol (IP) network. The base station may also coordinate attribute management of the air interface. For example, the base station may be a base station (BTS, Base Transceiver Station) in a GSM or a CDMA, may also be a base station (NodeB) in a WCDMA network, and may further be an evolved base station (NodeB or eNB or e-NodeB, evolutional Node B) in an LTE network, which is not limited in the present application.
The base station controller may be a base station controller (BSC, base station controller) in the GSM network or the CDMA network, or a radio network controller (RNC, Radio Network Controller) in the WCDMA network, which is not limited in the present application.
Further, the terms “system” and “network” in this specification may always be exchanged for use in this specification. The term “and/or” in this specification is only an association relationship for describing the associated objects, and represents that three relationships may exist, for example, A and/or B may represent the following three cases: A exists separately, both A and B exist, and B exists separately. In addition, the character “/” in this specification usually represents that the former and later associated objects are in an “or” relationship.
An embodiment of the present application provides a method for reporting a signal quality measurement result, which involves a terminal side, as shown in FIG. 1 .
101 : Receive adjacent frequency information, an adjacent-frequency signal quality reporting amount, and a reporting threshold corresponding to the adjacent-frequency signal quality reporting amount from a radio network node.
The adjacent frequency information may refer to a specific frequency name that is notified from the radio network node to the terminal.
In a specific LTE system, the adjacent-frequency signal quality reporting amount includes an RSRP (reference receiving signal power, reference signal received power) or an RSRQ (reference receiving signal quality, reference signal received quality). If the adjacent-frequency signal quality reporting amount is RSRP, correspondingly, the reporting threshold is an RSRP reporting threshold; and if the adjacent-frequency signal quality reporting amount is RSRQ, the reporting threshold is an RSRQ reporting threshold.
102 : Perform measurement according to the adjacent frequency information to obtain an adjacent-frequency signal quality measurement result.
Specifically, the terminal determines, according to a preset measurement rule, whether to measure the signal quality of an adjacent frequency, and determines to measure the signal quality on which adjacent frequency, so as to obtain the adjacent-frequency signal quality measurement result.
For example, the terminal may perform measurement according to a cell reselection measurement rule; when the signal quality of a serving cell is higher than a specific threshold, the terminal may start measuring an adjacent frequency whose priority is higher than a specific priority; and when the signal quality of the serving cell is lower than a specific threshold, the terminal may start measuring all adjacent frequencies. It should be noted that, the rule used in the example is a rule among the cell reselection measurement rules; with the evolution of network technologies, the cell reselection rule may change, and even a new type of measurement rule may come into being. However, regardless of which rule is used, the UE may measure an adjacent frequency and obtain adjacent-frequency signal quality.
103 : Report the adjacent-frequency signal quality measurement result in a preset bit string format to the radio network node according to the adjacent frequency information, the adjacent-frequency signal quality reporting amount, and the reporting threshold, so that the radio network node obtains the adjacent-frequency signal quality according to the adjacent-frequency signal quality measurement result.
The radio network node obtains the adjacent-frequency signal quality measurement result reported by the terminal, so as to obtain the adjacent-frequency signal quality; based on this, the radio network node makes a decision for determining whether to perform redirection and cell change on the terminal that reports the adjacent-frequency signal quality measurement result.
Each adjacent frequency received from the radio network node corresponds to a bit in the preset bit string; when the bit value is a first value (for example, 1), it indicates that: there is a cell with the signal quality higher than the reporting threshold on the corresponding frequency; and when the bit value is a second value (for example, 0), it indicates that: there is no cell with the signal quality higher than the reporting threshold on the corresponding frequency or there is no corresponding frequency for the bit.
Each adjacent frequency received from the radio network node corresponds to a bit in the preset bit string, where the preset bit string includes N bits, and the number of adjacent frequencies received from the radio network node is k; both N and k are integers greater than 0 and N≧k; when the bit values of the 1st to k-th bits in the preset bit string are the first value (for example, 1) it indicates that there is a cell with the signal quality higher than the reporting threshold on the corresponding frequency for each of the 1st to k-th bits; and when the bit values of the 1st to k-th bits in the preset bit string are the second value (for example, 0), it indicates that there is no cell with the signal quality higher than the reporting threshold on the corresponding frequency for each of the 1st to k-th bits.
When the bit values of the (k+1)-th to N-th bits in the preset bit string are the second value (for example, 0), there is no corresponding frequency for these bits; and when the bit values of the (k+1)-th to N-th in the preset bit string are the first value (for example, 1), there is a corresponding frequency for these bits and there is a cell with the signal quality higher than the reporting threshold on the corresponding frequency.
An embodiment of the present application further provides a method for reporting a signal quality measurement result, which involves a radio network node side, as shown in FIG. 2 . This method includes the following steps:
201 : Send adjacent frequency information, an adjacent-frequency signal quality reporting amount, and a reporting threshold corresponding to the adjacent-frequency signal quality reporting amount to a terminal.
If the adjacent-frequency signal quality reporting amount is RSRP, the corresponding reporting threshold is an RSRP reporting threshold; and if the adjacent-frequency signal quality reporting amount is RSRQ, the reporting threshold is an RSRQ reporting threshold.
202 : Receive an adjacent-frequency signal quality measurement result reported in a preset bit string format by the terminal, so that the radio network node obtains the adjacent-frequency signal quality according to the adjacent-frequency signal quality measurement result.
The embodiment of the present application provides a method for reporting a signal quality measurement result, by receiving adjacent frequency information, an adjacent-frequency signal quality reporting amount, and a reporting threshold corresponding to the adjacent-frequency signal quality reporting amount from a radio network node, obtaining an adjacent-frequency signal quality measurement result, and reporting the adjacent-frequency signal quality measurement result in the preset bit string format to the radio network node, the reporting of the adjacent-frequency signal quality measurement result by a terminal is implemented, so that the radio network node is capable of making, according to the adjacent-frequency signal quality measurement result, a decision for the terminal to change to a cell, thereby increasing the success rate of cell handover, redirection, and cell change.
Another embodiment of the present application provides a method for reporting a signal quality measurement result, as shown in FIG. 3 .
301 : A radio network node sends adjacent frequency information, an adjacent-frequency signal quality reporting amount, and a corresponding reporting threshold to a terminal.
If the adjacent-frequency signal quality reporting amount is RSRP, the corresponding reporting threshold is an RSRP reporting threshold; and if the adjacent-frequency signal quality reporting amount is RSRQ, the reporting threshold is an RSRQ reporting threshold.
The radio network node may be a base station; for example, the base station may be abase station (BTS, Base Transceiver Station) in a GSM network or a CDMA network, may also be a base station (NodeB) in a WCDMA network, and may further be an evolved base station (eNB or e-NodeB, evolutional Node B) in an LTE network; or a base station controller, for example, a base station controller (BSC, base station controller) in the GSM network or the CDMA network, may also be a radio network controller (RNC, Radio Network Controller) in the WCDMA network, which is not limited in the present application.
Specifically, the radio network node may, through a system broadcast message or a dedicated RRC message, send the adjacent frequency information, the adjacent-frequency signal quality reporting amount, and the corresponding reporting threshold to the terminal.
302 : The terminal, according to the adjacent frequency information, performs measurement to obtain an adjacent-frequency signal quality measurement result.
303 : Report the adjacent-frequency signal quality measurement result to the radio network node by using a preset bit string.
When the preset bit string is used to report the adjacent-frequency signal quality measurement result, the adjacent-frequency signal quality reporting amount, and the reporting threshold need to be used as a reference for setting a bit value. Specifically, each adjacent frequency received from the radio network node corresponds to a bit in the preset bit string; when the bit value is 1, it indicates that: there is a cell with the signal quality higher than the reporting threshold on the corresponding frequency; and when the bit value is 0, it indicates that: there is no cell with the signal quality higher than the reporting threshold on the corresponding frequency or there is no corresponding frequency for the bit.
For an existing SIB19 (system information broadcast 19, system broadcast information 19) format, a maximum of 8 frequencies may be contained in the SIB19 for sending. Therefore, the preset bit string may be an 8-bit bit string, and each frequency corresponds to a bit.
The following example further explains step 301 to step 303 . The reported frequency information sent by the radio network node contains 5 frequencies, namely, P1, P2, P3, P4, and P5, respectively; the adjacent-frequency signal quality reporting amount is RSRQ; and the RSRQ reporting threshold is X. The adjacent-frequency signal quality measurement results for 5 frequencies P1, P2, P3, P4, and P5 measured by the terminal are X1, X2, X3, X4, and X5, respectively. The bit string selected by the terminal contains at least 5 bits corresponding to the adjacent-frequency signal quality measurement results for the 5 frequencies P1, P2, P3, P4, and P5. This assumes that the selected bit string contains 8 bits. If X1>X, X2>X, X3<X, X4<X, and X5>X, the obtained bit string 11001 indicates the adjacent-frequency signal quality measurement result, and the bit string from left to right corresponds to the frequencies P1, P2, P3, P4, and P5 in sequence. The remaining three bits are all set to 0, indicating that there is no frequency corresponding to the three bits; in this situation, the entire 8-bit bit string is 11001000. Then, the terminal reports 11001000 to the radio network node.
It should be noted that the terminal may, through the preset bit string in an RRC connection request (RRC connection request), a cell update (cell update) message, an initial direct transfer (initial direct transfer) message, an uplink initial direct transfer (uplink direct transfer) message, or a measurement report, send the adjacent-frequency signal quality measurement result to the radio network node. For example, when the RRC connection request, the cell update message, the initial direct transfer message, the uplink initial direct transfer message, or the measurement report is ready to be sent, whether the current adjacent-frequency signal quality measurement result of the terminal is valid is first detected; where the valid may refer to whether the adjacent-frequency signal quality measurement result is out of date; different types of terminals may have different requirements for a valid storage period for the adjacent-frequency signal quality information; and if the adjacent-frequency signal quality information is not out of date, it is considered valid and may be used. In this situation, the preset bit string may be used to report the current adjacent-frequency signal quality measurement result to the radio network node. The current adjacent-frequency signal quality information that has become invalid is not reported. Another manner is as follows: when whether the current adjacent-frequency signal quality measurement result is valid is detected, whether there is a cell with the signal quality higher than the reporting threshold is further detected; if there is the cell with the signal quality higher than the reporting threshold, the preset bit string is used for reporting; and if there is no cell with the signal quality higher than the reporting threshold, the bit string is an all-0 bit string; and the current adjacent-frequency signal quality measurement result indicated by the all-0 bit string has no reference meaning for the radio network node to control cell change for the terminal. Consequently, reporting may not be performed.
304 : The radio network node obtains the adjacent-frequency signal quality from the received adjacent-frequency signal quality measurement result, and according to the adjacent-frequency signal quality, makes a decision for the terminal to change to a cell.
Specifically, according to the descriptions of the steps, the adjacent-frequency signal quality measurement result received by the radio network node is an 8-bit bit string 11001000, it is known that the adjacent-frequency signal quality measurement results of the P1, P2, and P5 exceed the reporting threshold. The radio network node may make, according to the adjacent-frequency signal quality, a decision for the terminal to change to a cell.
For example, the radio network node, based on the network load status, or the terminal service type, or the signal quality of a serving cell for the terminal, makes a decision on whether to change to a cell for the terminal; for example, the UE is considered to be transferred to another cell that is more appropriate for the UE; in this situation, the radio network node, referring to the adjacent-frequency signal quality measurement result reported by the terminal, by means of handover, redirection or cell change, transfers by priority the terminal to an adjacent frequency whose bit value is 1.
To further optimize the adjacent-frequency measurement result reported by the terminal, the network side may preset a plurality of bit strings with different lengths; when the terminal reports the adjacent-frequency signal quality measurement result, according to the number of adjacent frequencies delivered by the network side or the number of reporting frequencies specified by the network side, the terminal selects a bit string with an appropriate length to report.
Further, if the adjacent frequency information sent by the radio network node contains few frequencies, for example, the frequencies contained in the adjacent frequency information are frequencies P1 and P2, the terminal uses two bits to respectively indicate the adjacent-frequency signal quality measurement results for the two frequencies P1 and P2, and reports the result to the radio network node; if the frequencies contained in the adjacent frequency information sent by the radio network node are P1, P2, P3, and P4, the terminal may use 8 bits to respectively indicate the adjacent-frequency signal quality measurement results for the frequencies P1, P2, P3, and P4, where 4 bits have no corresponding adjacent-frequency signal quality measurement results and are set to 0. Using 2 bits and 8 bits is only one of optional manners, and actual applications are not limited to this. For example, when the number of specified frequencies is 4, 4 bits may be used to report the adjacent-frequency signal quality measurement result; and when the number of specified frequencies exceeds 8, a bit string with more than 8 bits may be used to report.
In addition, it should be noted that, if the radio network node, delivers a system broadcast message only with frequencies used for the terminal during a cell reselection, and does not explicitly specify the frequencies for reporting the measurement result in the system broadcast message or a dedicated RRC message, the delivered frequencies used for the terminal during the cell reselection in the system broadcast message are considered as the frequencies for which the measurement results need to be reported by the terminal; if the radio network node, in addition to deliver the frequencies used for the terminal during the cell reselection in the system broadcast message, explicitly specifies the frequencies for reporting the measurement result in the system broadcast message or the dedicated RRC message, in this situation, the terminal determines the explicitly specified frequencies as the frequencies for which the measurement results need to be reported. For example, if the radio network node delivers P1, P2, and P3 in the system broadcast message, and then does not explicitly specify the frequencies for reporting the measurement result, P1, P2, and P3 are considered as the frequencies for which the measurement results need to be reported by the terminal; and if the radio network node delivers P1, P2, and P3 in the system broadcast message and also explicitly specifies P1 in the system broadcast message or the dedicated RRC message, the terminal only determines P1 as the frequency for which the measurement result needs to be reported by the terminal.
The radio network node described in the embodiment of the present application, includes a radio network controller, an evolved base station, or a base station controller, and other nodes with a radio resource management function.
The adjacent frequencies described in the embodiment of the present application include frequencies of a neighboring cell in an LTE system, frequencies of a neighboring cell in a GSM system/GPRS system or frequencies of a neighboring cell in a wireless local area network (Wireless Local Area Networks, WLAN).
The method for reporting a signal quality measurement result provided by the embodiment of the present application, by receiving adjacent frequency information, an adjacent-frequency signal quality reporting amount, and a reporting threshold from the radio network node, obtaining an adjacent-frequency signal quality measurement result, and reporting the adjacent-frequency signal quality measurement result to the radio network node by using a preset bit string, the radio network node is capable of making, according to the adjacent-frequency signal quality measurement result, a decision for the terminal to change to a cell, thereby increasing the success rate of cell handover, redirection, and cell change.
Another embodiment of the present application provides a terminal, as shown in FIG. 4 , where the terminal includes: an information receiver 41 , a measurement processor 42 , and a sender 43 .
The information receiver 41 is configured to receive adjacent frequency information, an adjacent-frequency signal quality reporting amount, and a reporting threshold corresponding to the adjacent-frequency signal quality reporting amount from a radio network node.
Specifically, in an LTE system, the adjacent-frequency signal quality reporting amount includes an RSRP reference receiving signal power or an RSRQ reference receiving signal quality, the reporting threshold includes an RSRP reporting threshold or an RSRQ reporting threshold.
The measurement processor 42 is configured to perform measurement to obtain an adjacent-frequency signal quality measurement result according to the adjacent frequency information.
The sender 43 is configured to report the adjacent-frequency signal quality measurement result in a preset bit string format to the radio network node according to the adjacent frequency information, the adjacent-frequency signal quality reporting amount, and the reporting threshold, so that the radio network node obtains the adjacent-frequency signal quality according to the adjacent-frequency signal quality measurement result.
Each adjacent frequency received from the radio network node corresponds to a bit in the preset bit string; when the bit value is 1, it indicates that: there is a cell with the signal quality higher than the reporting threshold on the corresponding frequency; and when the bit value is 0, it indicates that: there is no cell with the signal quality higher than the reporting threshold on the corresponding frequency or there is no corresponding frequency for the bit.
The sender 43 is specifically configured to report, when an RRC radio resource control protocol connection request, a cell update message, an initial direct transfer message, an uplink initial direct transfer message, or a measurement report message needs to be sent, the current adjacent-frequency signal quality measurement result to the radio network node by using the preset bit string; the sender 43 is further configured to report, when the RRC radio resource control protocol connection request, the cell update message, the initial direct transfer message, the uplink initial direct transfer message, or the measurement report message needs to be sent, and if the current adjacent-frequency signal quality measurement result contains a cell with the signal quality higher than the reporting threshold, the current adjacent-frequency signal quality measurement result to the radio network node by using the preset bit string.
The adjacent frequencies include frequencies of a neighboring cell in an LTE system, frequencies of a neighboring cell in a GSM system/GPRS system or frequencies of a neighboring cell in a wireless local area network.
For the specific functions of the terminal and the functional units of the terminal, reference may be made to the descriptions of the foregoing method embodiments, and details are not described herein again.
In addition, an embodiment of the present application further provides a radio network node; where, the radio network node may be a base station; for example, the base station may be a base station (BTS, Base Transceiver Station) in a GSM network or a CDMA network, may also be a base station (NodeB) in a WCDMA network, and may further be an evolved base station (eNB or e-NodeB, evolutional Node B) in an LTE network; or a base station controller, for example, abase station controller (BSC, base station controller) in the GSM network or the CDMA network, may also be a radio network controller (RNC, Radio Network Controller) in the WCDMA network, which is not limited in the present application. As shown in FIG. 5 , the radio network node includes a sender 51 , a receiver 52 , and a processor 53 .
The sender 51 is configured to send adjacent frequency information, an adjacent-frequency signal quality reporting amount, and a reporting threshold corresponding to the adjacent-frequency signal quality reporting amount to a terminal.
Specifically, in an LTE system, the adjacent-frequency signal quality reporting amount includes an RSRP reference receiving signal power or an RSRQ reference receiving signal quality, the reporting threshold includes an RSRP reporting threshold or an RSRQ reporting threshold.
The receiver 52 is configured to receive an adjacent-frequency signal quality measurement result reported in a preset bit string format by the terminal.
The processor 53 is configured to obtain the adjacent-frequency signal quality according to the adjacent-frequency signal quality measurement result.
Each adjacent frequency received from the radio network node corresponds to a bit in the preset bit string; when the bit value is 1, it indicates that: there is a cell with the signal quality higher than the reporting threshold on the corresponding frequency; and when the bit value is 0, it indicates that: there is no cell with the signal quality higher than the reporting threshold on the corresponding frequency or there is no corresponding frequency for the bit.
In addition, as shown in FIG. 6 , the sender 51 specifically includes a sub-sender 511 , which is configured to send, through a system broadcast message or a dedicated RRC radio resource control protocol message, the adjacent frequency information, the adjacent-frequency signal quality reporting amount, and the reporting threshold to the terminal.
For the specific functions of the radio network node and the functional units of the radio network node, reference may be made to the descriptions of the foregoing method embodiments, and details are not described herein again.
An embodiment of the present application further provides a system for reporting a signal quality measurement result, as shown in FIG. 7 , the system includes a terminal 71 and/or a radio network node 72 .
The terminal 71 is configured to receive adjacent frequency information, an adjacent-frequency signal quality reporting amount, and a reporting threshold corresponding to the adjacent-frequency signal quality reporting amount from a radio network node 72 ; according to the adjacent frequency information, perform measurement to obtain an adjacent-frequency signal quality measurement result; and report the adjacent-frequency signal quality measurement result in a preset bit string format to the radio network node 72 according to the adjacent frequency information, the adjacent-frequency signal quality reporting amount, and the reporting threshold, so that the radio network node 72 obtains the adjacent-frequency signal quality according to the adjacent-frequency signal quality measurement result.
The radio network node 72 is configured to send the adjacent frequency information, the adjacent-frequency signal quality reporting amount, and the reporting threshold corresponding to the adjacent-frequency signal quality reporting amount to the terminal 71 , receive the adjacent-frequency signal quality measurement result reported in the preset bit string format by the terminal 71 , and obtain the adjacent-frequency signal quality according to the adjacent-frequency signal quality measurement result.
The terminal, the radio network node, and the system for reporting a signal quality measurement result provided by the embodiments of the present application, by receiving adjacent frequency information, an adjacent-frequency signal quality reporting amount, and a reporting threshold delivered by the radio network node, obtaining an adjacent-frequency signal quality measurement result, and reporting the adjacent-frequency signal quality measurement result to the radio network node by using a preset bit string, the radio network node is capable of making, according to the adjacent-frequency signal quality measurement result, a decision for the terminal to change to a cell, thereby increasing the success rate of cell handover, redirection, and cell change.
It can be clearly understood by a person skilled in the art that, for the purpose of convenient and brief description, division of the foregoing function modules is taken as an example for illustration, in actual implementation, the foregoing functions can be allocated to different modules and implemented according to the need, that is, inner structure of the apparatus is divided into different function modules to implement all or part of the functions described above. For a detailed working process of the foregoing system, apparatus and unit, reference may be made to the corresponding process in the method embodiments, and details are not described herein again.
In the several embodiments provided in the present application, it should be understood that the disclosed system, apparatus, and method may be implemented in other manners. For example, the described apparatus embodiment is merely exemplary; for example, the division of a module or a unit is merely logical function division and may be other division in actual implementation; for example, a plurality of units or components may be combined or integrated into another system, or some features may be ignored or not performed. In addition, the displayed or discussed mutual couplings or direct couplings or communication connections may be implemented through some interfaces; and the indirect couplings or communication connections between the apparatuses or units may be implemented in electronic, mechanical, or other forms.
The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one position, or may be distributed on a plurality of network units. A part or all of the units may be selected according to an actual need to achieve the objectives of the solutions of the embodiments.
In addition, functional units in the embodiments of the present application may be integrated into a processor, or each of the units may exist alone physically, or two or more units are integrated into a unit. The integrated unit may be implemented in a form of hardware, or may be implemented in a form of a software functional unit.
When the integrated units are implemented in the form of a software functional unit and sold or used as an independent product, the integrated units may be stored in a computer-readable storage medium. Based on such an understanding, the technical solutions of the present application essentially, or the part contributing to the prior art, or all or a part of the technical solutions may be implemented in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for instructing a computer device (which may be a personal computer, a server, or a network device) or a processor (processor) to perform all or a part of steps of the methods described in the embodiments of the present application. The storage medium includes any medium that can store program code, such as a USB flash drive, a removable hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a magnetic disk, or an optical disk.
It should be noted that the foregoing embodiments are merely intended for describing the technical solutions of the present application other than limiting the present application. Although the present application is described in detail with reference to the foregoing embodiments, a person of ordinary skill in the art should understand that they may still make modifications to the technical solutions described in the embodiments, or make equivalent replacements to some technical features in the technical solutions thereof, without departing from the spirit and scope of the technical solutions of the embodiments of the present application. | The present application discloses a method, a device, and a system for reporting a signal quality measurement result, relates to the field of communications, and implements reporting of an adjacent-frequency signal quality measurement result by a terminal. Embodiments of the present application disclose a method for reporting a signal quality measurement result, including: receiving adjacent frequency information, an adjacent-frequency signal quality reporting amount, and a reporting threshold corresponding to the adjacent-frequency signal quality reporting amount from a radio network node; according to the adjacent frequency information, performing measurement to obtain an adjacent-frequency signal quality measurement result; and reporting the adjacent-frequency signal quality measurement result in a preset bit string format to the radio network node. The embodiments of the present application are mainly used for redirection, handover, and cell change operations of a terminal. | 7 |
INCORPORATION BY REFERENCE TO ANY PRIORITY APPLICATIONS
[0001] Any and all applications for which a foreign or domestic priority claim is identified in the Application Data Sheet as filed with the present application are hereby incorporated by reference under 37 CFR 1.57.
BACKGROUND OF THE INVENTION
[0002] Field of the Invention
[0003] The present invention relates to drilling devices used in, for example, the oil industry and, in particular, concerns an under reamer tool used to widen the diameters of bore holes.
[0004] Description of the Related Art
[0005] Drilling is commonly performed in industries such as the oil industry where holes are drilled into the ground to receive pipe. Similar holes are also drilled to receive pipe in water applications such as wells and the like.
[0006] One tool that is commonly used is a tool known as an under reamer which extends down through a pipe and then has expandable arms so as to drill a bore hole that is wider than the diameter of the pipe. The arms are preferably expandable through the use of a hydraulic piston that causes the arms to extend outward from the central shaft of the tool.
[0007] Typical under reamers used today have three arms spaced at equal intervals about the outer diameter of a vertical portion of the tool. The three arms are prone to breakage and also prone to vibratory movement as a result of smaller size and due to the design of the tool itself.
[0008] Consequently, there is a need for an under reamer that is more robust in design and less prone to vibration than existing under reamers.
SUMMARY OF THE INVENTION
[0009] The aforementioned needs are satisfied by the under reamer of the present invention which, in one non-limiting example or embodiment comprises an under reamer having a central shaft with two arms that are pivotable outward from the central shaft located at opposite sides of the central shaft. The arms are preferably pivotally mounted to the central shaft with a retaining pin formed on either side of the arms. The arms, in one non-limiting example have two lots that engage with the pivot pins.
[0010] In another non-limiting example, the holder block engages with the upper end of the arms and a pivot pin extends through the arms and the central shaft to permit pivoting of the arms. In this example, the retaining pins are also located through the shaft to engage either side of the arms. The use of dual retaining pins reduces vibration and prolongs the life of the tool. Moreover, the use of two arms also prolongs the life of the tool as the arms can be formed to be larger size and therefore more robust.
[0011] These and other objects and advantages will become more apparent from the following description taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIGS. 1A-1C are isometric views of one exemplary embodiment of a dual precision under reamer of the present disclosure;
[0013] FIGS. 2A and 2B are isometric views of the arms of the under reams of FIGS. 1A-1C ;
[0014] FIGS. 3A and 3B are holder blocks of the dual precision under reamer of FIGS. 1A-1C ;
[0015] FIGS. 4A and 4B are retaining pins of the dual precision under reamer of FIGS. 1A-1C ;
[0016] FIGS. 5A and 5B are a cross-sectional view of the under reamer of 1 A- 1 C that schematically shows the operating mechanism;
[0017] FIG. 6 is a view of a cam member of the under reamer of FIGS. 1A-1C ; and
[0018] FIG. 7 is a front view of the under reamer of FIGS. 1A-1C .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0019] Reference will now be made to the drawings wherein like numerals refer to like parts throughout. FIGS. 1A and 1B illustrate an exemplary dual precision under reamer 100 of one embodiment of the present invention. In this embodiment, the under reamer 100 includes a central shaft 102 that can be 44 inches long but this size may vary depending upon the application. A plurality of arms 104 a , 104 b which, in this case comprises two arms, extend pivotally outward from the central shaft 102 . The arms 104 a , 104 b are hydraulically activated so that a desired diameter of the bore hole can be selected. The end of the shaft 102 may also include a known digging implement.
[0020] Digging implements 106 are formed on outer portion of the arm to facilitate digging of the bore hole. The arms 104 a , 104 b are retractable into openings 108 so that the under reamer 100 can be inserted through a pipe to the digging depth. The openings 108 may include cut outs 110 that are sized to receive the digging implements 106 .
[0021] The arms 104 a , 104 b are shown in greater detail in FIG. 2A and 2B . In this implementation, the arms 104 a, 104 b have a pivot hole 112 on one end so as to be pivotally attached to the central shaft 102 in a manner that will be described in greater detail below. The arms 104 also have an outward digging surface 114 . As is also shown either of the side surfaces 116 of the arms include an arcuate groove 120 that receives a retaining pin in a manner that will be described in greater detail below.
[0022] The arms 104 are secured in place via a pivot pin that extends through the pivot hole 112 and the central shaft 102 . Further, a holder block 130 is secured to the central shaft 102 and the holder block 130 defines an arcuate surface 132 that engages with a mating surface 134 on the arms 104 to reinforce the interaction between the arms 104 and the central shaft.
[0023] A retaining pin component 140 is also attached to the central shaft via a mounting body 142 that is offset from a pin body 144 . The retaining pin body 144 is positioned within the arcuate grooves 120 on either side of the arms 104 so as to reduce vibration of the arms when the assembly 100 is rotated during digging operations.
[0024] The relative positioning and functionality of these components are shown in greater detail in FIGS. 5A and 5B . As shown, the shaft 102 defines an inner bore opening 150 that extends the length of the shaft 150 . The outer walls 152 of the shaft are relatively thick, e.g., on the order of approximately 3.75″ or 3.735″ inches thick in one non-limiting embodiment adjacent where the arms 104 a , 104 b are pivotally attached to the main shaft 10 . The openings 108 in the shaft that accommodate the arms 104 have exemplary dimensions of approximately 2.265 inches wide, approximately 16.750 inches long inches long and are spaced approximately 180 degrees about the outer circumference of the shaft 102 . As shown, the pivot openings 112 in the shaft that receive pivot pins and extend through pivot openings 113 in the arms 104 are positioned at an upper end of the openings 108 .
[0025] As shown in FIG. 2A , the arms 104 a , 104 b define an opening 160 that has a deeper flat portion 162 and an angled portion 164 that extends towards the outer end of the arms 104 a , 104 b that accommodates the digging implements 106 . In one implementation, the arms 104 a , 104 b are approximately 10.25 inches in length, approximately 2.25 inches in width, and approximately 2.75 inches in depth. The flat portion 162 of the opening 160 is approximately 1 inch deep and approximately 0.094 inches wide and the angled portion 162 extends at an approximately 25 degree angle with respect to the outer surface of the arms 104 a , 104 b.
[0026] The assembly 100 further includes a cam member 170 that is mounted inside the opening 150 in the shaft 102 . The cam member 170 is shown in greater detail in FIG. 6 . The cam member 170 has an opening 172 that engages with a piston, in a manner that will be described in greater detail below, and two bearing arms 174 a , 174 b that are positioned within the openings 108 of the digging arms 104 in the manner shown in FIGS. 5A and 5B . The cam member 170 also includes two positioning arms 176 a , 176 b that engage with the inner walls of the inner opening 150 of the shaft 102 to stabilize the cam member 170 .
[0027] As shown in FIGS. 5A and 5B , the cam member 170 is coupled to the shaft 182 of a piston 180 that is positioned within the opening 150 of the central shaft 102 . As the piston 180 is actuated, the cam member 170 is urged forward where the cam member bearing arms 172 a , 174 b engage with the angled portions 164 of the arms 108 which thereby urge the arms outward in the manner shown in FIG. 5B . As such, the degree of deployment of the arms 108 a , 108 b away from the central shaft 102 is controllable by the extension of the shaft 182 of the piston 180 .
[0028] As shown in FIG. 5A and 5B , the shaft 102 has a reduced diameter portion 194 which defines an opening to receive the holder block 130 via bolts 192 . The arcuate surface 132 of the holder block 130 engages with the arcuate surface 134 of the arms 108 a , 108 b in the manner shown in FIGS. 5A and 5B . The reduced diameter portion 194 also defines an opening 190 through which the shaft 182 of the piston 180 extends. The reduced diameter portion 194 also defines a flange 196 that is used to spring bias the piston shaft 182 .
[0029] The piston shaft 182 includes a fastener 200 that extends through the piston shaft 182 and is connected to the cam 170 . The piston shaft 102 includes a thicker portion 202 that overlaps the flange 196 but is not as wide as the opening 150 of the shaft 182 so as to define gaps 204 . The thicker portion 202 of the piston shaft 182 includes a flange 206 that extends into the gaps 204 such that a spring 210 can be interposed between the flange 196 of the shaft 182 and the flange 206 of the thicker portion of the piston shaft 182 . The spring 210 biases the cam 170 into the position of FIG. 5A whereby removal of force from the piston on the shaft 180 results in the spring retracting the shaft 182 thereby returning the cam 170 to the deeper portion 162 of the arm 108 a , 108 b thereby retracting the arms 108 a , 108 b into the position of FIG. 5A . The piston 180 can be similar to existing pistons of the prior art.
[0030] FIG. 7 is a front view of the under reamer 100 which shows the relative positioning of the arms 104 a , 104 b . As shown, the arms 104 a , 104 b are spaced so as to be 180 degrees apart from each other around the circumference of the shaft 102 . The use of two arms 104 a , 104 b permits this relative spacing. Further, the use of two arms 104 a , 104 b as opposed to the typical three in prior art devices permits the use of heavier arms 104 a , 104 b which lessens the chance the device can become disabled as a result of the arms breaking. Still further, the use of two arms results in greater side wall material that is supporting the arms and inhibiting twisting of the arms during digging operations. In one exemplary implementation, the shaft 102 is approximately 6″ in diameter and has walls having a thickness of approximately 2 to 3.75″ with the arms 104 a , 104 b being positioned approximately 180 degrees apart from each other about the circumference of the shaft 102 .
[0031] It will be apparent from the foregoing description that various changes to the form, implementation and uses of the described embodiments may be made by those skilled in the art without departing from the sprit, teachings or scope of the instant application. Hence, the scope of the instant application should not be limited to the foregoing but should be defined by the appended claims. | A under reamer that has two arms and is piston activated. The under reamer arms are supported on both side walls by a pin assembly. The under reamer arms are extended outward by a piston assembly which is spring biased to retract the arms. A surface of the under reamer arms adjacent the pivot point is protected via a holder assembly with a surface that matches the surface of the arms adjacent the pivot assembly. | 4 |
FIELD OF THE INVENTION
[0001] This invention relates, in general, to an anti-splatter device and deals more particularly with an anti-splatter device, which protects users from grease or other splatters while cooking.
BACKGROUND OF THE INVENTION
[0002] It is well known that chefs, as well as non-professional cooks, experience various hot splattered material during the cooking of food over a stove. When a cook is manipulating the food, these hot splatters may come in contact with the cook's nearby hands. This problem is especially dangerous when frying food due to the hot grease splatters that occur. Of course, these splattered materials are not only limited to contacting the cook's hands. Other body parts, such as the face or arm, are also likely to be burned or injured by the splattered material.
[0003] Various devices have been used in an attempt to overcome these problems. Some devices involve the use of specialized lids or barriers to prevent splattering. However, these devices either hinder manipulation of any cooking utensils or provide no protection at all when manipulating the food. In addition, the lids are limited to a single size of pot or pan, and thus, they cannot be used easily with other pots or pans. It is also known to use longer cooking utensils, which can also obstruct the cook's view. However, splattered material can still fly considerable distance, and the length makes manipulation of the utensil difficult.
[0004] With the forgoing problems and concerns in mind, it is therefore a general object of the present invention to provide an anti-splatter device, which protects the user from splattered material while allowing for easy manipulation of the food.
SUMMARY OF THE INVENTION
[0005] It is an object of the present invention to provide an anti-splatter device, which protects the user from splattered material.
[0006] It is another object of the present invention to provide an anti-splatter device, which allows for easy manipulation of food while cooking.
[0007] It is another object of the present invention to provide an anti-splatter device, which is freestanding.
[0008] It is another object of the present invention to provide an anti-splatter device, which is transparent.
[0009] It is another object of the present invention to provide an anti-splatter device that allows for ease of movement while in use.
[0010] It is another object of the present invention to provide an anti-splatter device that may be used regardless of the size or type of the pot, pan, or the like.
[0011] These and other objectives of the present invention, and their preferred embodiments, shall become clear by consideration of the specification, claims, and drawings taken as a whole.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 illustrates an anti-splatter device according to one embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0013] As will be appreciated by a review of FIG. 1 , the anti-splatter device of the present invention is a freestanding transparent shield with a small aperture. The anti-splatter device is designed to be placed in front of a cooking surface to protect a user from splattered material, which may occur during the cooking of food.
[0014] FIG. 1 illustrates an anti-splatter device 10 according to one embodiment of the present invention. As can be seen in FIG. 1 , the anti-splatter device 10 has a horizontal base 12 and a shield 14 , which projects upwardly from the horizontal base 12 . The shield 14 includes an aperture 16 and, optionally, a handle 18 .
[0015] The shield 14 of the anti-splatter device 10 is orthogonal to the base 12 in the preferred embodiment. However, the shield 14 may be angled to any degree. The shield 14 is also preferably transparent so that the user may see through the anti-splatter device 10 in order to cook. Thus, the shield 14 is preferably formed from a plastic, acrylic, glass, plexi-glass, or polymer material.
[0016] In the preferred embodiment, the base 12 of the anti-splatter device 10 is substantially rectangular with the shield 14 attached centrally along the major axis of the base 12 . However, the shield 14 may be attached anywhere onto the base 12 . The base 12 may be made of the same material as the shield 14 or a completely different material. Since the function of the base 12 is to support the shield 14 rather than viewing the food and cooking surface, it is not necessary for the base 12 to be transparent. The base 12 may also have rubber feet on its lower surface in order to prevent slippage on the cooking surface.
[0017] It is therefore an important aspect of the present invention that the shield 14 upwardly projects from the base 12 . This configuration provides protection to a user while also allowing the anti-splatter device 10 to be freestanding and movable.
[0018] Returning to FIG. 1 , the anti-splatter device 10 allows a user to manipulate a cooking utensil through the aperture 16 while still providing a barrier between the user and the cooking surface. As shown, the aperture 16 is centrally located on the shield 14 . However, the aperture 16 may be placed at any location. Furthermore, multiple apertures may be located on the shield 14 , if desired. Moreover, the aperture 16 , as shown, is circular, but the aperture 16 may be any shape.
[0019] It is therefore an important aspect of the present invention that the shield 14 includes the aperture 16 . The aperture 16 allows a user to manipulate cooking food using a utensil while remaining behind the anti-splatter device. It has been heretofore unknown to include an aperture with a freestanding shield. The present invention does not require a user to reach around a shield while cooking. Reaching around a shield makes cooking awkward and potentially more dangerous. With the present invention, a user may manipulate a utensil through the aperture 16 while remaining safely behind the anti-splatter device 10 . Moreover, the present invention allows the user to quickly and easily switch which utensil is being used through the aperture 16 since the utensil is not fixedly attached in any way to the anti-splatter device 10 . Utensils that are fixedly attached to various barriers have been previously proposed. Thus, the present invention provides flexibility in the use of various utensils without excessive delay caused by attaching a barrier to the utensil.
[0020] Returning to FIG. 1 , the anti-splatter device 10 may also include a handle 18 on one side of the shield 14 . The handle 18 may be any configuration. The handle 18 allows for a user to easily move the anti-splatter device 10 from one position to another. For example, a user may stir a pot of sauce on the left side of a cooking surface while utilizing the anti-splatter device 10 . Then, the user can move the anti-splatter device 10 to the right side of the cooking surface to fry food in a pan.
[0021] It is therefore an important aspect of the present invention that the anti-splatter device 10 is easily movable from one position to another. Some previous devices in the form of lids have been limited to certain sizes of pots, pans, or the like. However, the present invention can be used with any pot or pan since it does not fit directly on them. Indeed, the anti-splatter device 10 is freestanding and can be moved where needed. The handle 18 makes transportation of the anti-splatter device 10 easier and safer, but the anti-splatter device 10 could also be moved without the handle 18 by gripping it from the side.
[0022] As described above and as illustrated in FIG. 1 , the anti-splatter device 10 of the present invention protects a user from splatters while still allowing the user to easily manipulate a utensil through the aperture 16 . The shield 14 of the anti-splatter device 10 is transparent to further accommodate the cooking of food. The base 12 allows the anti-splatter device 10 to be freestanding, and the handle 18 makes it easily movable.
[0023] While the invention has been described with reference to the preferred embodiments, it will be understood by those skilled in the art that various obvious changes may be made, and equivalents may be substituted for elements thereof, without departing from the essential scope of the present invention. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed, but that the invention includes all equivalent embodiments. | An anti-splatter device for cooking is provided. The anti-splatter device includes a base, a shield extending upwardly from the base, and an aperture in the shield. The anti-splatter device protects a user from splatters produced while cooking and also allows for easy manipulation of food using a utensil through the aperture. Moreover, the anti-splatter device is easily movable to provide protection at various cooking areas while in use. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is U.S. national phase filing under 35 U.S.C. §371 of PCT/IB2014/002348 filed on Nov. 5, 2014 and entitled “IMMUNOSUPPRESIVE TREATMENTS, FORMULATIONS AND METHODS,” which claims priority from U.S. Provisional Application No. 61/899,934 filed on Nov. 5, 2013 and entitled “COMPOSITIONS AND METHODS FOR DRUG DELIVERY.” Both of the aforementioned applications are incorporated herein by reference in their entirety.
FIELD
The present disclosure relates to immunosuppressive methods, pharmacologic treatment formulations, and immunosuppressive treatments for immune mediated diseases of the tear film and cornea of the eye.
BACKGROUND
Ophthalmic tear film disorders or dry eye can be caused by traumatic orbital injury to the neural innervation or circulation to the lacrimal or tear gland, lacrimal gland neoplasia, congenital lacrimal gland disease, endocrine disease, and immune mediated eye and systemic diseases that affect the lacrimal gland. Lymphocytic invasion of the lacrimal gland results in quantitative and qualitative tear film disease. Immune mediated dry eye conditions include but are not limited to keratoconjunctivitis sicca (KCS) and Sjögren's syndrome (SS). Persistent corneal erosions and conjunctivitis can accompany KCS. Clinical signs of KCS include ocular discomfort, blurred vision, mucoid ocular discharge, conjunctival hyperemia, tear film instability, blepharospasm, recurrent corneal erosion and ulceration, corneal vascularization and pigmentation, and can ultimately lead to blindness if treatment is ineffective.
Treatments for dry eye and other related immune mediated diseases of the eye include anti-inflammatory drugs, antibiotics, antiproteases, artificial tears, and immunomodulatory drugs. Therapy may not be effective due to ocular irritation caused specifically by the fact the topical drug used is inherently irritating or the drug formulation is irritating. Poor ocular corneal contact time can result in poor drug bioavailability, and systemic absorption of the topical drug can also cause, low tear film and corneal drug levels. Failure of the drug to return tear production to normal levels may occur if the specific drug is not sufficiently able to prevent the immune mediated attack on the lacrimal gland. Poor drug stability, incorrect drug pH, variation in reproducibility of batch-to-batch dry eye drug production, difficulties in drug sterilization during drug production, low drug loading in sustained release techniques, and/or limitations for large-scale drug production are also problems in pharmacologic production of drugs for the treatment of dry eye and other related immune mediated diseases of the eye.
There is thus a continued need for improved immunosuppressive treatments, formulations and methods for the treatment of dry eye and/or other related immune mediated diseases of the eye.
SUMMARY
The present disclosure provides inventive methods and formulations for immunosuppressive therapy for dry eye and other related immune mediated eye diseases. In example embodiments, the formulations comprise one or more immunomodulatory drugs such as liposome encapsulated rapamycin and tacrolimus, which can be administered, parenterally and topically respectively. Such drugs can be formulated and administered to address the causes and/or reduce the symptoms of dry eye and/or other related immune mediated diseases of the eye.
DETAILED DESCRIPTION
The present disclosure includes immunosuppressive treatments, formulations and methods for the treatment of dry eye and/or other related immune mediated diseases of the eye. Persons skilled in the art will readily appreciate that various aspects of the disclosure may be realized by any number of treatments, formulations and methods configured to perform the intended functions. Stated differently, other treatments, formulations and methods may be incorporated herein to perform the intended functions. Although the present disclosure may be in connection with various medical principles and beliefs, the present disclosure should not be bound by theory.
The term “approximately,” as used in this specification and appended claims, refers to plus or minus 5% of the value given. The term “about,” as used in this specification and appended claims, refers to plus or minus 10% of the value given.
While the present disclosure will be described primarily with reference to KCS or dry eye, persons skilled in the art will readily appreciate that the teachings herein may be applied more broadly in iritis, cyclitis, anterior uveitis, phacoanaphylactic endophthalmitis, uveodermatologic syndrome and other immune mediated diseases of the eye. Teachings in this disclosure can also have application to cancer therapy, and the therapy of systemic immunologic diseases including but not limited to Addison's disease, celiac disease, dermatomyositis, Graves' disease, Hashimoto's thyroiditis, multiple sclerosis, myasthenia gravis, pernicious anemia, reactive arthritis, rheumatoid arthritis, systemic lupus erythematosus, and type I diabetes.
Persons skilled in the art will further appreciate that the teachings herein may be applied to human as well as animal subjects (e.g., dogs, rabbits, cats, horses, primates or other domestic or wild subjects), young subjects and adult subjects, and male and female subjects.
An example of a typical immunosuppressive treatment comprises a primary formulation, which may be administered by itself or together with a secondary formulation. When primary and secondary formulations are administered together, they can be administered in the same pharmaceutical form (e.g., compounded together), or can be administered in different pharmaceutical forms alone or substantially contemporaneously one with another.
By way of example, a primary formulation can be administered before or after a secondary formulation, administration of primary and secondary formulations can be staggered, and the frequency of administration of primary and secondary formulations can be the same or different.
A suitable route of administration or drug form for either or both of the primary and secondary formulations can be topical (e.g., eye drop solution, eye drop suspension, eye drop ointment, eye drop cream), oral (e.g., tablet, capsule) or parenteral (e.g., subconjunctival injection). Importantly, the primary and secondary formulations can be administered through the same or different route of administration or drug form.
Either or both of the primary and secondary formulations can comprise one or more immunomodulatory drugs. Examples include rapamycin (molecular weight 914.17, C 51 H 79 NO 13 , also known in the art as sirolimus), calcineurin inhibitors, including but not limited to tacrolimus (molecular weight 804.02, C 44 H 69 NO 12 , also known in the art as FK506) and cyclosporine A (molecular weight 1202.61, C 62 H 111 N 11 O 12 ), lacrimogenic and immunosuppressant medications, antibody production suppressors, and other T and B lymphocyte activation or proliferation inhibitors.
One or more immunomodulatory drugs can be present in a stable formulation in a suitable amount depending on the targeted tissue, the physicochemical properties of the active compound to be used, and the desired kinetic of ocular release. Without intending to limit the foregoing, in example embodiments, an immunomodulatory drug can be present in an amount of about 0.01% (g/ml) to about 0.2% (g/ml), or more preferably about 0.04% (g/ml) to about 0.1% (g/ml).
In example embodiments, the primary and secondary formulations comprise complementary immunomodulatory drugs. Indeed, the inventors have found that rapamycin and tacrolimus have a synergistic effect when used together in a common stable, long acting, immunosuppressive treatment achieving effective ophthalmic therapy, reaching adequate amount of ingredients, maintaining therapeutic drug dose levels at the site of action for long times within the eye, and minimizing undesirable systemic side effects.
In various embodiments, the synergistic effect results in the required dose for each being reduced and thus reducing undesirable systemic side effects. Without intending to be bound by theory, the synergistic effect can refer to shared metabolism (e.g., by CYP 3A), shared cytosolic binding protein (e.g., FKBP), common or complimentary regulation of T lymphocyte and B lymphocyte activation or proliferation, common or complimentary immune and/or inflammatory response pathway mediation, or other nonlinear effect or mutualism of a plurality of immunomodulatory drugs.
In this regard, an example immunosuppressive treatment consists of, or consists essentially of, rapamycin and tacrolimus. Put another way, an example immunosuppressive treatment does not comprise cyclosporine A or any other T lymphocyte and B lymphocyte activation or proliferation inhibitor. In yet other embodiments, an immunosuppressive treatment comprises a first immunomodulatory drug that is a non-calcineurin inhibitor, and a second immunomodulatory drug that is a calcineurin inhibitor.
In addition to an immunomodulatory drug, either or both of the primary and secondary formulations can comprise one or more dispersion vehicle solvents and dispersant agents, for example, saline solutions, e.g., phosphate buffer saline (PBS), aqueous dextrose and glycerol solutions, ethanol, and the like. One or more dispersion vehicle solvents and dispersant agents can be present in a formulation in an amount of up to about 99.97%.
Either or both of the primary and secondary formulations can also comprise one or more excipients, for example, olive oil, starch, glucose, lactose, sucrose, gelatin, malt, rice, flour, chalk, silica gel, sodium stearate, glycerol monostearate, talc, sodium chloride, dried skim milk, glycerol, propylene, glycol, water, ethanol and the like. One or more excipients can be present in a formulation in an amount of up to about 99.97%.
Delivery of either or both of the primary and secondary formulations can be facilitated with a carrier, for example, liposomes or other nanocarriers. As used herein, a “liposome” is any microscopic vesicle comprised of a lipid bilayer (or many lipid bilayers) surrounding an aqueous core that can enhance the solubilization and absorption of an encapsulated drug while protecting the drug from premature degradation and increasing residence time of the drug inside the body.
In example embodiments, liposomes can comprise one or more of lecithin (e.g., soybean or sunflower derived) or other phospholipids (e.g., dimyristoylphosphatidylcholine or dipalmitoylphosphatidylcholine), cholesterol and a cryoprotector (e.g., sucrose or trehalose).
Liposomes herein (e.g., obtained by adapting the heating method as discussed infra), have diameters ranging from about 135 nm to about 215 nm, or more preferably from about 180 nm to about 200 nm, with an entrapment efficiency of from about 90% to about 99.5%, or more preferably from about 93% to about 98%. In example embodiments, liposomes herein can have a phospholipid concentration of from about 1 mM to about 10 mM, or more preferably about 5 mM.
In yet other embodiments, delivery of a formulation can be targeted to a particular cell or region of interest. In addition, or in the alternative, a formulation can be configured to remain in contact or in close proximity to a particular cell or region of interest for an extended period of time.
Methods of making immunosuppressive treatments and formulations are also provided herein. In an example embodiment, liposomes are loaded with an immunomodulatory drug, for example rapamycin. Liposomes for use with an immunomodulatory drug herein can be prepared using the ethanol injection method or the heating method, both as known by persons skilled in the art. In other embodiments, liposomes can be prepared using an inventive adaptation of the heating method.
In an example embodiment of such adaptation, cholesterol and lecithin are hydrated with PBS for 1 hr under N 2 , the former at 80° C. and the latter at room temperature. The lipid dispersions are then mixed together with the desired rapamycin amount in the presence of glycerol (3% v/v) and the volume made up to 10 mL. The mixture is heated to 70° C. while stirring at 750 rpm for 30 min. The resultant dispersion is left at room temperature under N 2 for 30 min. The dispersion is extruded with a stainless steel pressure filter holder (Millipore Co., U.S.A.) through polyvinylidene fluoride (PVDF) hydrophilic membrane of 0.45 μm pore size (Durapore HVLP, Millipore Co., U.S.A.) with a N 2 pressure inlet of 2 bars. In example embodiments, the extrusion step is conducted at a temperature above the phase transition temperature of the phospholipids. Example methods of making also comprise a freeze drying step, by freezing the sample in liquid nitrogen, a primary drying at −45° C. at maximum power vacuum (2×10 −3 mBar) followed by a secondary drying at 25° C. at maximum power vacuum. Finally, the dispersion is sterilized, collected in amber glass sterile vials and kept in refrigeration until use. In example embodiments, the use of an adaptation of the heating method developed by the inventors does not comprise the use of any organic solvents or surfactants in the manufacturing process, minimizes toxicity, shortens manufacturing time, reduces cost, and/or allows industrial production scaling.
Methods of use of immunosuppressive treatments and formulations are also provided herein. In example embodiments, a topical formulation can be administered from about every 4 hours to about every 12 hours, an oral formulation can be administered from about every 12 hours to about every 2 days, and a parenteral formulation can be administered from about every 2 days to about every 30 days. Notwithstanding the foregoing, persons skilled in the art will appreciate that longer or shorter dosing intervals may be appropriate depending on the concentrations and indications.
As a non-limiting example of an immunosuppressive treatment and method of use of the same, an example primary formulation comprises a suspension of approximately 0.4 mg/ml or 1.0 mg/ml rapamycin encapsulated in soybean lecithin, cholesterol and sucrose liposomes, and glycerol, the balance comprised of PBS with a pH of approximately 7.45, as set forth in Table I.
TABLE I
Example Primary Formulation A
Ingredient
Weight/Volume Percentage (g/ml)
Rapamycin
0.04-0.1%
Cholesterol
0.077-1.01%
Lecithin
0.23-3.05%
Glycerol
2.4%
Sucrose
0.92-12.2%
PBS
Quantity sufficient for 100%
The formulation of Table I is then administered in an amount of approximately 0.15 ml via subconjunctival injection every 15 days for 2 months or until instructed by a physician.
Yet another example of a primary formulation is set forth in Table II.
TABLE II
Example Primary Formulation B
Ingredient
Weight/Volume Percentage (g/ml)
Rapamycin
0.04%
Cholesterol
0.404%
Lecithin
1.22%
PBS
Quantity sufficient for 100%
An example secondary formulation of the same immunosuppressive treatment comprises a suspension of approximately 0.03% tacrolimus in olive oil. The formulation is administered in an amount of approximately one eye drop every 8 hours for 2 months or until instructed by a physician.
Example immunosuppressive treatments, formulations and methods for the treatment of dry eye were tested in a clinical trial, and the results were unexpected and surprising.
The objective of the trial was to evaluate the combination of topically administered tacrolimus and liposome encapsulated rapamycin in dogs with severe KCS nonresponsive to conventional medical therapy.
Seventeen dogs (29 eyes) were studied with a Schirmer tear test I value of less than 5 mm wetting/minute.
The eyes received a subconjunctival injection of liposomes with rapamycin at a dose of 0.4 mg/ml every 15 days for two months. Topically administered medication of 0.03% tacrolimus was also utilized, one drop every 8 hours. Complete ophthalmologic evaluation using a modified McDonald-Shadduck protocol that included Schirmer tear tests (STT) I and II and tear film break up time (TFBUT) were made every 15 days.
The McDonald-Shadduck protocol is described in the following references, each of which is incorporated by reference herein in its entirety for all purposes. Hackett, R. B., & McDonald, T. O. (1991). Eye irritation. HEMISPHERE PUBLISHING CORPORATION, NEW YORK, N.Y. (USA)., 749-815. Gritz, D. C., McDonnell, P. J., Lee, T. Y., Tang-Liu, D., Hubbard, B. B., & Gwon, A. (1992). Topical Ofloxacin in the Treatment of Pseudomonas Keratitis in a Rabbit Mode. Cornea, 11(2), 143-147. York K K, Miller S, Gaster R N, Burstein N L. Polyvinylpyrrolidone iodine: corneal toxicology and epithelial healing in a rabbit model. J Ocul Pharmacol. 1988 Winter; 4(4):351-8.
STT is described in the following references, each of which is incorporated by reference herein in its entirety for all purposes. Schirmer O. Studien zur physiologie und pathologie der traneabsonderung und tranenabfuhr. Graefes Archiv für Klinische und Experimentische Ophthalmologie 1903; 56: 197-291. Williams, D. L. (2005). Analysis of tear uptake by the Schirmer tear test strip in the canine eye. Veterinary ophthalmology, 8(5), 325-330. Gelatt K N, Peiffer N L, Erickson J L, Gum G G. Evaluation of tear formation in the dog using a modification of the Schirmer tear test. J American Veterinary Medical Association 1975; 166: 368-370.
TFBUT is described in the following references, each of which is incorporated by reference herein in its entirety for all purposes. Moore C P, for M M Wilsman N J, Nordheim E V, et al: Density and distribution of canine conjunctival goblet cells, Invest Ophthalmol Vis Sci 1987; 28: 1925-1932. Kallarackal, G. U., Ansari, E. A., Amos, N., Martin, J. C., Lane, C., & Camilleri, J. P. (2002). A comparative study to assess the clinical use of Fluorescein Meniscus Time (FMT) with Tear Break up Time (TBUT) and Schirmer's tests (ST) in the diagnosis of dry eyes. Eye, 16(5), 594-600. Cho, P., Leung, L., Lam, A., & Choi, A. (1998). Tear break-up time: clinical procedures and their effects. Ophthalmic and Physiological Optics, 18(4), 319-324.
The modified McDonald-Shadduck score system is a slit lamp scale for scoring ocular irritation that uses also indirect ophthalmoscopy and neuro-ophthalmic reflexes for ocular media clarity. It graduates in a 0 to 4 score (0 is the normality and 4 maximum alteration): clarity of ocular media, eyelids, cornea, % area of corneal opacity, corneal vascularization, conjunctival congestion, conjunctival chemosis/swelling, conjunctival discharge (color and consistency), aqueous flare, aqueous cell, cell color, iris and lens.
During the trial, as shown in Tables III-V below, it was observed that STT I and II, and the TFBUT improved significantly during the 2 month treatment period (P<0.001). Clinical signs improved significantly with reduction in corneal opacity (p<0.001), conjunctival congestion (P<0.001), conjunctival chemosis (P<0.001) and conjunctival discharge (P<0.001). The modified McDonald-Shadduck results also displayed statistically significant improvement (P<0.001).
TABLE III
Shirmer tear test I and II, Median mm/min (min value; max value)
Day after initiation of treatment
0
15
30
45
60
P value
STT I
1.5 (0.0; 4.0)a
4.0 (0.0; 15.0)ab
4.0 (0.0; 21.0)bc
4.5 (0.0; 20.0)c
6.0 (0.0; 21.0)d
P < 0.001
STT II
0.0 (0.0; 4.0)a
0.0 (0.0; 10.0)ab
0.0 (0.0; 11.0)ab
1.5 (0.0; 13.0)b
2.0 (0.0; 13.0)b
P < 0.001
STT—Schirmer tear test
Equal letters - no significant difference
Different letters - significant difference
TABLE IV
Tear film break up time, Median sec (min value; max value)
Day after initiation of treatment
0
15
30
45
60
P value
TFBUT
6.0 (4.0; 13.0)a
10.0 (5.0; 21.0)b
10.0 (5.0; 25.0)bc
10.0 (5.0; 25.0)bc
11.0 (6.0; 25.0)c
p < 0.001
TFBUT—tear film break up time
Equal letters - no significant difference
Different letters - significant difference
TABLE V
Modified McDonald-Shadduck test results, Median
(min value; max value)
Day after initiation of treatment
0
15
30
45
60
P value
Eyelids
1.0 (0.0; 2.0)b
0.0 (0.0; 2.0)ab
0.0 (0.0; 2.0)ab
0.0 (0.0; 2.0)ab
0.0 (0.0; 2.0)a
p < 0.001
% CO
2.0 (1.0; 4.0)b
1.5 (1.0; 4.0)ab
1.0 (0.0; 3.0)ab
1.0 (0.0; 3.0)ab
1.0 (0.0; 3.0)a
p < 0.001
CC
2.0 (0.0; 2.0)c
1.0 (0.0; 2.0)b
1.0 (0.0; 2.0)ab
0.5 (0.0; 2.0)ab
0.0 (0.0; 1.0)a
p < 0.001
CCh
1.0 (0.0; 2.0)b
0.0 (0.0; 2.0)a
0.0 (0.0; 2.0)a
0.0 (0.0; 2.0)a
0.0 (0.0; 2.0)a
p < 0.001
CD
2.0 (1.0; 3.0)c
1.0 (0.0; 2.0)b
1.0 (0.0; 2.0)b
1.0 (0.0; 2.0)ab
1.0 (0.0; 2.0)a
p < 0.001
CDCC
2.0 (1.0; 3.0)c
1.0 (0.0; 2.0)b
1.0 (0.0; 2.0)b
1.0 (0.0; 2.0)ab
1.0 (0.0; 2.0)a
p < 0.001
% CO, % area of corneal opacity
CC, conjunctival congestion
CCh, conjunctival chemosis
CD, conjunctival discharge
CDCC, conjunctival discharge color and consistence
Equal letters - no significant difference
Different letters - significant difference
In the trial, the treatment used did not cause ocular irritation or other side effects in any animal studied. The association of topical tacrolimus with liposomes containing rapamycin was effective in alleviating the clinical signs of KCS in dogs, as well as increased tear production and tear film quality of the studied animals.
Treatments, formulations and methods are provided. In the detailed description herein, references to “various embodiments”, “one embodiment”, “an embodiment”, “an example embodiment”, etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described. After reading the description, it will be apparent to one skilled in the relevant art(s) how to implement the disclosure in alternative embodiments.
Moreover, where a phrase similar to ‘at least one of A, B, and C’ or ‘at least one of A, B, or C’ is used in the claims or specification, it is intended that the phrase be interpreted to mean that A alone may be present in an embodiment, B alone may be present in an embodiment, C alone may be present in an embodiment, or that any combination of the elements A, B and C may be present in a single embodiment; for example, A and B, A and C, B and C, or A and B and C.
The foregoing disclosure is merely illustrative of the present disclosure and is not intended to be construed as limiting the invention. Although one or more embodiments of the invention have been described, persons skilled in the art will readily appreciate that numerous modifications could be made without departing from the spirit and scope of the present disclosure. By way of example, a formulation in accordance with the present disclosure can comprise, consist essentially of, or consisting of, any combination of the ingredients described above. As such, it should be understood that all such modifications are intended to be included within the scope of the disclosure. | The present disclosure provides inventive methods and formulations for immunosuppressive therapy for dry eye and other related immune mediated eye diseases. The formulations can comprise one or more immunomodulatory drugs such as parenterally administered liposome encapsulated rapamycin and topically administered tacrolimus. Immunomodulatory drugs herein can be formulated and administered to address the causes and/or reduce the symptoms of dry eye and/or other related immune mediated diseases of the eye. | 0 |
This is a continuation of application Ser. No. 08/048,077, filed on Apr. 14, 1993, now abandoned which is a continuation of Ser. No. 07/687,962 filed on Apr. 19, 1991, (now abandoned).
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to color correction systems for video signals, and in particular, to color correction systems in which either an entire color space or particular points in the space may be altered.
2. Description of the Related Art
Color correction systems for selectively correcting electronic signals representing optical images are well known in the art. Various forms of color correctors are used in many sophisticated video systems. In particular, sophisticated color correctors are used in film-to-video conversion systems, such as telecines. In many cases, and particularly in the case of telecines, color correction is needed to overcome color inaccuracies or nonlinearities introduced by the film or by electronic scanning of the optical film images to produce the corresponding video signals.
Color correctors in such systems often require levels of skill beyond the capabilities of operators or editors. Indeed, color correction is often viewed as more art than science. With the growing use of video systems and the corresponding growth in need for editors for such systems, color correctors which require less skill, while providing equivalent if not better color correction, are needed.
A difficult aspect of color correction involves video signal characteristics, such as hue, intensity and saturation. Some color correction systems essentially use a "painting" type of approach, where each object is separately selected and assigned a particular color. Colorization of black and white films often uses this approach. This type of approach is time consuming and difficult, as it does not allow for all objects of a given color to be modified at once, but rather all must be "painted" separately.
Alternatively, some devices allow for changes to the entire color space, i.e. all reds may be altered, or all blues or all greens. However, it is often desireable to alter only those shades of a color falling within a certain range of the color space, and to alter those shades precisely. While some prior art devices can perform such general alterations, the desired precision is not provided for by the prior art devices, other than the "painting" technology above, and in those cases the process again is a long and difficult one.
Another major difficulty facing editors, or "colorists," is that most color correction circuitry in conventional color correction systems is done in an analog fashion, and is thus not very precise or flexible. If adjustments are made to accommodate one particular parameter being corrected, some or all of the other parameters are usually also affected to varying degrees. Some newer, more sophisticated color correction systems, such as special effects machines, do use some digital designs. However, these machines again do not allow for a global modification of a particular part of the color space.
SUMMARY OF THE INVENTION
The present invention provides a digital color correction system and method for correcting a color video signal representing a portion of a colored optical image by modifying the entire color space of each of the complementary colors which make up the color signal so that all objects which contain each color are modified at once.
To accomplish this, the present invention provides for correction means for producing an output video signal having a plurality of complementary color components, each of which is related to a corresponding color component of the color video signal by a transfer function, and modification means for independently modifying each of the transfer functions.
The present invention also provides for modifying either the entire color space for each color, or only selected portions of it. Thus, only objects falling within a desired range of the color space may be selectively modified.
The color correction provided by the present invention can be selectively done on any basis. For example, color correction or encoding can be done on a frame-by-frame or scene-by-scene basis, or even on a field-by-field basis, as desired.
The features and advantages described in the specification are not all inclusive, and particularly, many additional features and advantages will be apparent to one of ordinary skill in the art in view of the drawings, specification and claims hereof. Moreover, it should be noted that the language used in the specification has been principally selected for readability and instructional purposes, and may not have been selected to delineate or circumscribe the inventive subject matter, resort to the claims being necessary to determine such inventive subject matter.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a block diagram of a color correction system in accordance with the present invention.
FIG. 1A illustrates a block diagram of one subsystem of the color correction system of FIG. 1.
FIG. 2 illustrates a graph of the transfer function, i.e. input versus output, of the color correction system of the present invention in the default condition.
FIG. 3 illustrates graphs of various types of global changes which may be made to the transfer function of FIG. 2.
FIG. 4 illustrates a user interface for making a local change to the transfer function of FIG. 2 in the preferred embodiment of the present invention.
FIG. 5 illustrates how the transfer function is modified with the interface of FIG. 4.
FIG. 6 illustrates a transfer function after a number of modifications.
FIG. 7 illustrates a color wheel in the HSV (hue, saturation and value) domain.
DETAILED DESCRIPTION OF THE INVENTION
FIGS. 1 through 6 of the drawings depict various preferred embodiments of the present invention for purposes of illustration only. One skilled in the art will readily recognize from the following discussion that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the invention described herein.
The present invention can be embodied within the apparatus disclosed in each of the following copending patent applications, assigned to the assignee of the present application: "Non-Real-Time Film Scanning System," by P. Capitant, D. Hodgson and V. Perry, filed Aug. 7, 1991 (Ser. No. 07/741,329, now patented. "Digital Color Correction System and Method," by P. Capitant, D. Collier and J. Carlucci, filed by Jun. 5, 1991 (Ser. No. 07/710,704, now patented; "Film Scanning Apparatus and Method," by J. Galt, V. Perry, L. Thorpe and D. West on Mar. 29, 1991 (Ser. No. 07/677,578, now patented. The specifications of the foregoing patent applications are incorporated herein by reference.
Referring to FIG. 1, a preferred embodiment of a digital color correction system 20 in accordance with the present invention consists of three subsystems 22, 24, and 26, one for each of the three signals corresponding to the three complementary colors, here red, green and blue, necessary to represent a full color signal.
The input signals R I , G I , B I and output signals R, G, B, as well as the signals in between, are digital with each signal preferably having twelve bits of information. Indeed, it has been suggested that color channels with at least 12 bits should be sufficient to ensure virtually error-free color reproduction, i.e. no visually perceptible quantization errors or anomalies (B. J. Lindbloom, "Accurate Color Reproduction for Computer Graphics Applications," Computer Graphics, Vol. 23, No. 3, Jul. 1989).
However, it should be understood that this example of 12 signal bits is merely exemplary and that, in accordance with the present invention, fewer or greater numbers of signal bits can be used, depending upon the desired resolution or accuracy. For example, while 12 bit A/D and D/A converters are available, they are still relatively expensive and too slow for practical use. On the other hand, 10 bit converters are inexpensive and readily available but do not provide the same level of resolution. A system using as few as 8 bits can be implemented, with a logarithmic stretch to compensate for the use of fewer bits, but this can introduce additional noise into the process. It should be further understood that as technology economically allows, even a greater number of bits, for example 14, 16 or more, may be more desirable.
Each of the functions performed within the system as described more fully below, is performed in a digital and synchronous manner. In other words, each twelve bit signal is processed digitally and synchronously.
Throughout FIG. 1 and the following discussion, several corresponding functional elements are referred to with like numerical designators having "R" "G" or "B" suffixes. The use of these suffixes is intended to indicate that those corresponding elements perform similar functions for their respective film or video color signals (e.g. red, green and blue).
Further, the following discussion refers to the color signals as corresponding to red, green and blue. However, it is understood that other complementary color combinations can be used, as desired. For example, the color trio of cyan, magenta and yellow can be used with equal effectiveness. Also, one could use P R , P B , and Y, where
P R =R-Y
P B =B-Y
Y=Luminance
Providing for the selective use of alternative color trios (e.g. red, green and blue, or alternatively cyan, magenta and yellow) is within the scope of the present invention and can be quite desirable to allow for the processing of either positive or negative images.
It should be further understood that the signal and interface lines discussed below can be provided and operated in either serial or parallel protocols, as desired. However, for maximum processing speeds, most if not all signals should preferably have their respective bits transferred or processed in parallel.
The input signals R I , G I , B I are twelve bit digital signals representing red, green and blue film color signals, which in turn represent red, green and blue colored optical film images, respectively. These can be normalized to some standard, for example to correct for camera or film characteristics, or may even be already altered for artistic purposes, as shown in the copending application of the assignee of the present invention "Digital Color Correction System and Method," by P. Capitant, D. Collier and J. Carlucci, filed by Jun. 5, 1991 (Ser. No. 07/710,704, now patented. Correction for camera or film characteristics, and artistic color correction in several prior art devices, is generally done using the logarithms of the color signals, in what is sometimes called the film domain, because the response of developed film dyes to light is easily expressed using logarithms.
Also as shown in the above-referenced copending application, it is possible to correct the color signal for the expected crosstalk effects of the display device prior to the color correction of the present invention.
The system of FIG. 1 subjects each of the three signals corresponding to the three complementary colors which comprise a color signal to a transfer function, so that the output signal for that color is related to the input signal by the transfer function. The three transfer functions are independent of one another so that each of the complementary colors may be corrected separately from the other two.
FIG. 1A illustrates, for example, red subsystem 22. As shown, the subsystem 22 is comprised of four look-up tables 28, 30, 32 and 34, multipliers 36, 38 and 40, delay circuits 52, and adders 42, 44 and 46. A controller 48 is used to modify the look-up tables as discussed below, based upon input from the user through user interface 50. The subsystem takes the input signal X and outputs a signal Y which is related to the input signal X, in a given interval, as
Y=DX.sup.3 +CX.sup.2 +BX+A
The input signal X acts as an address, which accesses the four look-up tables 28, 30, 32 and 34. For each input, or address, there is a corresponding value of A, B, C and D. Through the multipliers 36, 38 and 40, delay circuits 52, and the adders 42, 44 and 46, the subsystem generates an output signal Y according to the above equation.
For reasons discussed below, the look-up tables allow the values of the coefficients A, B, C and D to vary across the range of the input signal X so that the resulting equation for the output signal Y is not the same for all input values. Instead, the color space is broken into intervals, each of which may have a different set of coefficients. Thus, one interval may have a set of coefficients A 1 , B 1 , C 1 and D 1 , while in the adjacent interval the coefficients may be A 2 , B 2 , C 2 and D 2 . The controller 48 modifies the values in the look-up tables 28, 30, 32 and 34 based upon input from user interface 50 as explained below.
FIG. 2 shows a graph of one possible transfer function of the subsystem of FIG. 1A for one of the three complementary colors, that is, what the output of the subsystem for that color is for any given input of that color. In the preferred embodiment, this transfer function is the default condition, although another transfer function may be selected as the default condition. In the default condition of the preferred embodiment, the output is directly proportional to the input, the ratio being the gain of the system. In the graph of FIG. 2, a bias is added, so that the input must be over a certain level A before there is any output.
The transfer function of FIG. 2 may thus be shown as:
Output=(gain * input)+bias
Y=BX+A
In other words, in the default condition C and D are zero. If the output signal is desired to be identical to the input signal, then the gain B is set to one and the bias A is also set to zero. In this situation, Y=X.
Again, the system of FIG. 1 has three separate transfer functions, one given by each subsystem 22, 24 and 26 for each of the complementary colors used, here red, green and blue. The transfer function for one color need not be the same as the transfer function for another color. Thus, in the default condition of FIG. 2, the values of B and A may differ for the red, green and blue signals, and may be differentiated as B R , B G and B B , and A R , A G and A B .
FIGS. 3 (a)-(c) show several types of global changes which can be made to the transfer function of FIG. 2. In FIG. 3(a) the gain A has been changed, thus changing the proportion between the output and the input, in case 1 increased and in case 2 decreased. In FIG. 3(b) the bias has been changed, again in case 1 increased and in case 2 decreased. FIG. 3(c) shows a different kind of change, that of limiting the bandwidth of the signal so that there is a minimum and a maximum output. This causes the output signal to be clipped to these limits, which can be useful in reducing reflections and highlights while preserving overall contrast. Again these changes may be made independently for each of the complementary color signals.
These global changes to the three complementary color signals are easily implemented. A small look-up table containing the values of the gain B and the bias A, and a means for altering the values in the table as desired, along with a filter if clipping is desired, is sufficient for this purpose. In fact, no look-up table is even needed if there is a user input for the gain.
However, it is often desireable to be able to modify the color signal within only a certain range of inputs. The present invention provides for this by allowing the user to modify the values of coefficients A, B, C and D for different input values.
In the preferred embodiment, the user sees a graph of the transfer function, such as the default condition of FIG. 2, with "control points" imposed on it, as shown in FIG. 4. The user points to one of the control points with a pointing device such as a mouse or trackball, and moves it vertically to set another output for the corresponding input, as shown by the arrow in FIG. 4. In the preferred embodiment the number of control points is kept to a number which can be easily handled, such as 5 to 8, and points in between the control points are interpolated. In the preferred embodiment, the user can add additional control points as desired to break the transfer function into smaller segments and make the effect of each move of a control point more localized. (While it is theoretically possible for the user to independently set or modify all 4096 points of the transfer function, as a practical matter this would be difficult, as well as tedious. This may also limit the number of control points which can be added. Further, available monitors do not have the resolution to display all 4096 points, although some programs allow the user to display an approximation of the entire curve and then zoom in on the desired portion.)
To interpolate, the curve at any particular point is locally approximated by a cubic equation of the form
Y=DX.sup.3 +CX.sup.2 +BX+A
where Y is the output and X is the input, as above. This is the reason for the specific configuration of the subsystems 22, 24 and 26, each of which generates a set cubic equations, one for each interval between two adjacent control points. (As above, the straight line transfer function of FIG. 2 is a form of this in which D and C are both zero.)
In non-mathematical terms, when a control point is moved, as shown in FIG. 4, the represented point of the transfer function and several points around it are used to establish a cubic equation for the regions on either side of the moved control point, and the values in the look-up table are altered to fit that equation within the range of inputs for which the transfer function is altered by the movement of the control point. FIG. 5 shows the change to the transfer function which results from the movement of the control point shown in FIG. 4. The dashed line is the original straight line transfer function.
It would also be possible to implement this by having a micro-processor calculate the resulting values of all 4096 points and using large look-up tables which actually specify the output for each input. Each transfer function would then be represented by 4096 points, one for each possible input. The desired output value for each possible input value could then be inserted into the look-up table, and no multipliers or adders would be necessary.
However, this approach suffers from two problems. First, it requires three look-up tables each having 4096 entries, and each entry must be large enough to contain the desired output signal, presumably of the same length as the input signal (here 12 bits). This requires a significant amount of memory. More importantly, the time to download the look-up tables becomes more significant the larger the tables are. (This may be particularly significant where the present invention is used in combination with a color processor such as that shown in the copending application of the assignee of the present invention "Digital Color Correction System and Method," by P. Capitant, D. Collier and J. Carlucci, filed by Jun. 5, 1991 (Ser. No. 07/710,704) now patented, in which as many as 18 bits are desired to allow for full resolution of the more sensitive logarithmic scale of the "film domain." With 18 bits, there can be 262,144 entries in each table and the time for downloading becomes a significant problem.)
Thus, it is desireable to reduce both the size of the look-up tables and the number of points which need to be set by the user. It is also desireable for the appearance of the color signal that there be continuity of the transfer function between adjacent points of input.
Thus, using cubic equations to determine the transfer function between the control points serves to reduce the size of the look-up tables since they need include only the coefficients to be used in determining the output signal, rather than the output signal itself, which are then fed to a circuit such as that shown in FIG. 1A to calculate the output signal.
When this is done, the look-up tables now contain values for coefficients A, B, C and D which vary with the intervals between the control points. For example, in FIG. 5, the transfer function remains unaltered when the input is less than V 1 or greater than V 2 , so that the output is still a straight line outside of that range. Thus, A and B are unchanged and C and D are still zero for such inputs. However, when the input signal is between V 1 and V 2 , A and B change and C and D are no longer zero, so that a cubic equation is generated for inputs in this range. Thus, the look-up tables contain fewer entries than the number of points are desired to represent the transfer function. (Additional storage must be provided to allow for the entry of additional control points.) The value of each specific input is calculated by a microprocessor on a real time basis, based upon the resulting cubic equations.
In the preferred embodiment, the interpolation of the curve between the control points is accomplished by a known mathematical technique of estimating curves known as a C-spline. In this technique, in mathematical terms, a point on the T-spline is defined as
X(s)=S(s)·G·P
where ##EQU1##
The τ-spline with a bias of 0.5 is the Cardinal spline. A bias and tension of 0.5 yields the Catmull-Rom spline.
The spline interpolation curve is then drawn between {x n-1 , y n-1 } and {x n , y n }. Note that any added point needs to be supplemented by three other points for a complete knot vector. The other points will be selected in the following manner.
An elasticity coefficient will be used to define the `arc` distance between the added knot and the base knots. Because the default curve is a straight line, the actual distance parameter used is the x coordinate offset. If {x n , y n } are the coordinates of the added knot, then
x.sub.n-1 =x.sub.n -ε, y.sub.n-1 =g(x.sub.n-1)
x.sub.n=1 =x.sub.n+ ε, y.sub.n+1 =g(x.sub.n+1)
where y=g(x) is the existing linear curve, {x n-1 , y n-1 } is the left adjacent knot, {x n+1 , y n+1 } is the right adjacent knot and e is the elasticity measure. If any previous knot can be found between the added knot and the adjacent knots defined above it becomes the new adjacent knot. The two extra knots needed, {x n-2 , y n-2 } and {x n+2 , y n+2 } are the next knot (or end point) encountered left and right, respectively, of the adjacent knots. In addition, because a new point was added, the curves between
{x.sub.n-2, y.sub.n-2 }→{x.sub.n-1, y.sub.n-1 }
and
{x.sub.n+1, y.sub.n+1 }→{x.sub.n+2, y.sub.n+2 }
have to be redrawn using {x n , y n } as a new knot point.
Each movement of a control point creates a similar change in the transfer function, so that virtually any curve may be created, such as that shown in FIG. 6, and the appropriate values of the transfer function between the control points determined by the coefficients in the look-up tables which are in turn set by the spline interpolation between the control points.
Another feature of the preferred embodiment is the ability to match colors, i.e. to select a particular color in a video signal being processed and change it to match a reference color. If the reference color is in another video signal, it is relatively easy to implement this by looking at the values of R', G' and B' in the selected color in the reference signal and adjusting the transfer functions of the three color spaces R, G and B such that the outputs for the inputs which create the color in the signal being processed change to create the desired color.
However, it is often desireable to match a color which is not provided by another video signal. Most often this is done with reference to a color wheel, in the HSV, or hue saturation and value, domain, a format with which many users are familiar. One implementation of such a color wheel is shown in FIG. 7.
Color wheels in general are well known. The wheel may be thought of as an inverted cone. The inverted pyramid in the lower left of FIG. 7 represents a vertical cross section of the cone. The vertical axis is value, or the amount of black in the color. Thus, at the bottom of the pyramid the signal is all black. The horizontal axis is saturation, or the amount of white in the color. In the center, there is no color so the signal contains only black and white, and thus a line up the center of the pyramid is a grey scale. As one moves to the sides of the pyramid color is added so that close to the center the color is pastel and toward the edges the color becomes intense.
The wheel in the upper left of FIG. 7 is a horizontal cross section of the cone. At the center the signal is grey. As one moves radially away from the center color is added, i.e. saturation, so that near the center it is again a pastel and toward the circumference it is very intense. The circumference of the circle is hue, so that the color changes as one moves around the circle.
In the typical user interface, the user changes the selected color by moving two pointers, the little circle in the wheel and the little circle in the pyramid, for example with a mouse or other pointing device. Note that saturation may be changed in either place, while hue and value must be changed on the proper part of the screen, either the wheel or the pyramid respectively.
The particular implementation shown also includes numerical values, so that a desired color, once found, can be recreated at will, and a box in the upper right corner in which an original color can be compared to the color represented by the current location of the pointers. One use of this is to choose a color in the video signal being processed which is desired to be changed. This is stored in the "original" box, and the pointers will adjust to show the hue, saturation and value of that color. The user can then move the pointers and see the newly chosen color in the "current" box.
When a desired color is found, if the user wishes to change the original color to the current color, the "Reset" button is selected by the mouse or other pointing device. This resets the original color to the color in the current box, which is represented by the pointers on the wheel and the pyramid. To accomplish this, the system translates the values of hue, saturation and value for the chosen color into values R', G' and B' and, as above, adjusts the transfer functions of the three color spaces R, G and B such that the outputs for the inputs which create the original color in the signal being processed change to those required to create the desired color. The values of R', G' and B' which correspond to the hue, saturation and value (H, S and V) of the selected color are determined as follows:
H [0,360], S, V [0,1]
R', G', B' [0,1]
If S=0, then R'=G'=B'=V
S≠0, then the following values are calculated
h=H/60
i=integer part of h
f=fractional part of h
p=V (1-S)
q=V (1-S·f)
t=V (1-S·(1-f))
and R', G', B' are determined by ##EQU2## Note that these equations also yield R'=G'=B'=0 where S=0, because p=q=t=V where S=0.
Additionally, it is possible to similarly implement any other color space, such as the CIE standard. All that is required is a set of equations for changing a selected color in the other color space into equivalent signals R', G' and B'.
The "Color Space" button is used to switch to another color space, for example, to switch from the HSV domain back to the RGB color space. It may also be used to switch to any other color space which is implemented in the system, such as the CIE standard mentioned above.
Thus, the user is able to effectively modify the transfer functions the color space by selecting a desired color from a color wheel and automatically changing a selected color in the video signal to match the selected color.
From the above description, it will be apparent that the invention disclosed herein provides a novel and advantageous apparatus for color correcting a color video signal either by transforming the inputs of all three complementary components of the signal, i.e. the entire color space, or by altering the transfer function of any one of the components, or even by altering the transfer function for only some inputs of one of the components.
The foregoing discussion discloses and describes merely exemplary methods and embodiments of the present invention. As will be understood by those familiar with the art, the invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. For example, the default transfer function may be changed, the means for altering the look-up table may be different, or another type of interpolation may be used. Accordingly, the disclosure of the present invention is intended to be illustrative, but not limiting, of the scope of the invention, which is set forth in the following claims. | A digital color correction system and method for correcting a color video signal representing a portion of a colored optical image by modifying the entire color space of each of the complementary colors which make up the color signal so that all objects which contain each color are modified at once. A correction means produces an output video signal having a plurality of complementary color components, each of which is related to a corresponding color component of the color video signal by a transfer function, and a modification means for independently modifying each of the transfer functions is provided. The entire color space for each color may be modified, or only selected portions of it. Thus, only objects falling within a desired range of the color space may be selectively modified. | 7 |
This application claims priority from German Patent Application No. 200 04 400.1, which was filed on Mar. 9, 2000 and is a continuation of PCT Application No. PCT/EP00/12800, which was filed on Dec. 15, 2000, and which are incorporated by reference herein.
BACKGROUND OF THE INVENTION
The present invention refers to a manufacturing network system comprising at least one master computer and at least one network computer linked therewith for the purpose of network management, said network computer being linked with a number of local control devices in the area of assembly lines, work stations, or the like, which local control devices are associated with field devices, such as initiators, actuators, screw control modules, or the like, of which corresponding work devices are controllable and/or actuable along the assembly lines, in the work stations, or the like, the network computer being provided with a number of software modules and/or being linked with software modules in the manufacturing network system.
It is known from practice that at present e.g., in car manufacturing various work stations are arranged along assembly lines, the work stations having inter alia assigned thereto control devices for screwers. With such a control device, it is possible to control a plurality of screwers and to monitor the action thereof e.g., with respect to torque. Known are also decentralized control devices, for instance, for workpiece carriers. For instance, part of the automotive vehicle can be moved along various work stations for the purpose of assembly on such a workpiece carrier. A higher-level computer is normally responsible for coordinating the workpiece carriers.
Many other working activities are carried out along such an assembly line, the corresponding working means being locally controlled or programmed as a rule without any corresponding status feedback to a central computer or master computer.
As a consequence, information on the various working activities, the progress of said activities, the time sequence of various working activities, or the like, can normally not be called, evaluated or monitored at a central place. For instance, there is also no appropriate storage of data of the various work stations and/or of data regarding parts of an automotive vehicle or the automotive vehicle on the whole during its manufacture. By analogy, it is also not possible to obtain information from the overall system through access in the area of the local devices, in particular, with respect to a product to be manufactured, or orders regarding a specific product, or the like.
It is therefore the object of the present invention to provide a manufacturing network system in which data are collected, stored, managed and evaluated in many ways, and in which queries are possible at almost any point of the network system. This object is achieved by the features of claim 1.
SUMMARY
At least one network computer is linked with a master computer at a planning level within the network system. Said network computer serves to acquire, manage and/or evaluate data. A plurality of local control devices are connected to the network computer. These devices are assigned to an assembly line, a work station or also several work stations separately or also in the area of the assembly line. Data are exchanged between local control device and network computer, and said data exchange may concern operating data and e.g., also control data. Such operating data are e.g., data on the field devices assigned to the local control device, their activities, times of use, or the like. Furthermore, such data may be alarm messages, failure messages, etc. The data exchange between network computer and local control devices is normally bidirectional, so that corresponding data can also be transmitted to the local control devices, for instance for the purpose of programming, or can be called therefrom by the network computer.
The connection between network computer and master computer may also be bidirectional, so that the network computer can be queried by the master computer, and vice versa.
Each of the local control devices comprises a connection to at least one field device which is controlled, monitored, programmed, or the like, by the local control device. Such field devices may be screwer controls, initiators, actuators, or the like, which control and monitor screwers accordingly and operate, control, monitor, or the like, other devices of the corresponding work station.
To acquire, manage, evaluate, distribute, etc., specific data in accordance with the requirements in this context, software modules are or can be installed within the manufacturing network system, and can e.g., be stored on the master computer, the network computer or the local control devices or further computers in the network system or can be called there via the network. The network computer coordinates and manages the data flow within the network system and between the various software modules.
Different protocols for taking over and transmitting data are known for such networks. One example is the TCP/IP reference model or also internet reference model which permits the transmission and transfer of data from and between different computers and networks and, in particular, communication between transport layer and internetwork layer. It is also possible to communicate on a so-called application layer within the manufacturing network system, the corresponding application protocols therefor being FTP, SMTP, HTTP, or the like. For instance, various web browsers are based on HTTP for providing web pages which may contain a mixture of texts, graphics, sound and video data. A corresponding communication between the various components of the manufacturing network system is also possible via such web pages and corresponding hyperlinks.
Some of the abbreviations used shall now be explained in the following:
TCP/IP
transmission control protocol/internet protocol
FTP
file transfer protocol
SMTP
simple mail transfer protocol
HTTP
hypertext transfer protocol
SQL
structured query language
CAQ
computer aided quality control
DDE
dynamic data exchange
ODBC
open database connectivity
SPS
programmable control system (programmable controller)
LAN
local area network
WAN
wide area network
The various software modules within the manufacturing network system may, e.g., include a program diagnosis module. Said module serves, in particular, to diagnose lower-level network components, such as local control device, communication link, field device, or the like.
The program diagnosis module may comprise a programming tool through which e.g., programming can take place from a central place of the network system.
To be able to make a remote diagnosis also from outside the manufacturing network system still within an intranet, or even from an extranet, the manufacturing network system may comprise a corresponding interface, for instance, for connection to the internet. Such a remote diagnosis could e.g., by carried out by suppliers of local control devices or field devices. The remote diagnosis may also serve to check screwers, measuring devices of the work station, or the like.
To be able to make a remote diagnosis independently of different manufacturers of different network components, such a lower-level network component with respect to the program diagnosis module may comprise a user-independent interface.
To obtain information, in particular, on lower-level network components, their states, interactivities, or the like, a software module may be a logbook module. In such a logbook module, corresponding versions, extensions, or the like, of the network can be stored and called again.
If there is an error message within the system, the system states can be checked through the logbook module to localize the fault or error, if necessary.
It is here possible to program corresponding system states for at least one input mask of an input means of the manufacturing network system.
To be able to adapt the logbook module to system changes and extensions in a simple way, such changes in the system can be entered and/or stored in the logbook module.
Moreover, the logbook module may comprise a clearance device through which calls and queries by network-external participants are e.g., possible via a modem, or the like.
It is also possible to change data existing in specific logbooks, and the structures thereof, by means of the logbook module and to store these in the network system.
To be able to provide information on maintenance and repair in the network system, a software module may be a maintenance module. This module contains the necessary maintenance and repair activities for the operator of the network system. An input is here possible via a corresponding input means in the network system with respect to these various activities. An internal repair can be notified through the maintenance module by sending a corresponding message. Furthermore, a corresponding confirmation message can be entered in the maintenance module, the message marking the end of the maintenance or repair activity.
Furthermore, the maintenance module may comprise a calculating means which e.g., calculates maintenance intervals in dependence upon an actual time of use, in particular, of a corresponding field device.
Furthermore, the maintenance module can control a display means for displaying a layout plan, in particular, of local control devices and/or field devices. In this display, corresponding components of the local control devices or the field devices may be highlighted for which maintenance or repair is intended. Accordingly, a message may also be sent directly by the maintenance module to the component of the network system to be maintained, for instance, in order to suppress the further use thereof and/or to replace said component by another component. The maintenance module may also output a list of the corresponding repair activities for the corresponding network component via an output means, such as a screen, printer, or the like.
To archive process data, user data and/or system data, a software module may be a data archiving module. Said software module allows the input of corresponding data archives via input means of the network system. Here, an archiving operation can be carried out automatically, e.g., at fixed time intervals, with respect to specific network components, or the like.
To archive logbooks prepared e.g., by means of the logbook module, data archiving module and logbook module may be connectable or connected in particular automatically for data transmission.
To obtain information, if necessary, on corresponding system changes, the data archiving module may contain an actual data set and at least one precursor version of the actual data set.
Furthermore, the data archiving module can be called and queried to obtain data on access rights by external systems, and to determine when and how often such external accesses might have taken place.
To obtain very different data about machines and their operation, a software module may be a machine and/or operating data acquisition module (MDE/BDE module). Such data are e.g., type and number of specific machines, optionally malfunctions of said machines, or logistical malfunctions assigned to the machine, warnings about operative states of the machine, such as excessive temperature of the oil, or the like, reports on lack of material, minimum amounts, number of pieces, or the like, and on the mode of operation of the machine, such as automatic operation, manual operation, maintenance, or the like.
The corresponding MDE/BDE module can directly communicate with the various machines via a TCP/IP connection to provide an actual state of the corresponding machines without any considerable time delay.
In this connection it is also of advantage when the data of the MDE/BDE module can be displayed by an output means and/or transmitted to further software modules. For instance, the above-mentioned states can be evaluated and displayed in time and graphically. The display may take place via a screen, a printer or also via transmission via a modem, or the like. On the basis of the data of the MDE/BDE module, work load and availability of a corresponding machine or also of the whole system can be calculated by a corresponding calculating means of said module for defined periods of time and may be displayed.
Via the MDE/BDE module, it is also possible to record time, personnel or set-up time for one or several machines. Likewise, automatic shift protocols, feedback by reporting systems to work places, etc., are possible in connection with said module.
To permit an overview of the whole company plant assigned to the network system, a software module may be a plant overview module for outputting at least operative states and plant overviews. With this module, it is e.g., possible to show states of work stations, transportation sections of the assembly lines, or the like. Furthermore, there may be simplified displays of the whole plant, a workpiece carrier flow diagram, or the like. As already stated in connection with the former software modules, the plant overview module can also communicate with the corresponding other software modules for exchanging data. The various modes of operation of the different work stations and machines can e.g., be graphically highlighted in a corresponding plant overview by the module on the basis of the data received from the MDE/BDE module.
For the input and/or provision of orders to be particularly controlled by the field devices, a software module may be an order module. The corresponding input can be made on a computer or by means of a corresponding input means within the manufacturing network system. It is possible to transmit the corresponding data directly via TCP/IP or to write the data onto a mobile data carrier.
The corresponding order data regard, for instance, the type of handling, desired working time, working sequence, or the like. Furthermore, an appropriate assignment of the respective work to a specific work station can be carried out by the order module. Like the already mentioned software modules, the order module can communicate with the other software modules. Moreover, the order module may have corresponding input/output means to output, e.g., a day forecast or also a day review with respect to the corresponding operations for handling the orders. Furthermore, order data may e.g., be output in encoded form as bar codes, labels, or the like, and can be decoded at the corresponding work stations by scanners, or the like.
To be able to carry out a quality check after completion of corresponding working steps in various work stations and to archive corresponding data, a software module may be a quality management module.
To be able to control and monitor the various field devices in the different work stations along the assembly line, the local control device may comprise a computer, in particular personal computer. At least parts of the above-mentioned software modules may be stored thereon. A local operation of the corresponding field devices is possible with the computer. Furthermore, operative states, alarms, messages, or the like, of the various field devices can already be received and evaluated here. The computer communicates via TCP/IP with the network computer and is connected via said computer, or also via a direct communication connection, to the master computer.
To be able to operate the local computer in an easy way, said computer may comprise a touch-sensitive screen. Specific sequences or queries displayed on the screen can thereby be started directly by touching corresponding symbols or icons.
The corresponding computers of the local control device may serve the direct control of the field devices, the computer possessing corresponding interfaces. To be able to carry out the control of such field devices in a more targeted way, the local control device may comprise a programmable controller (SPS) which is, in particular, connected via a bus system to the field devices. Said controller may here communicate via TCP/IP with the computer of the local control device or also directly with the network computer or the master computer.
A so-called Profibus may e.g., be used as a bus system.
To provide, in particular at the level of the control devices, a substitute without any substantial time delay in case of failure of a controller, a programmable control system (SPS) may be a master SPS. The latter ensures data security in case of failure of one of the other controllers. Furthermore, for a redundant system each of the individual controllers may contain data of the predecessor and successor control through the respective controller.
To store all data within the network system and, in particular, to keep them available for queries within the system, the network computer may comprise a database and/or may be connected to a database. For instance, a database directly assigned to the network computer is an actual database which contains the corresponding actual states of the network system and the corresponding components. A further database which, inter alia, contains corresponding desired values for the various components of the network system may be assigned to the master computer. Communication with the databases may take place by means of a corresponding query language, such as SQL, or the like.
Communication with the database takes place on two levels, i.e., with the master computer and also with lower levels of the manufacturing network system assigned to the master computer.
To be able to input, e.g., data for maintenance pictures in the network system, the system may comprise an input means for said data. Said input means is e.g., a further computer within the network system. Corresponding masks for displaying the data can be called both on the network computer and the local control devices. The corresponding data are stored in a database of the network system. Access is via SQL or ODBC. To update the corresponding data, the database may be queried cyclically for changes. The corresponding change values can then be transferred to the respective masks.
To be able to carry out identification, control and monitoring, in particular, in the area of the field devices and the further devices in the area of the assembly lines and work stations, the manufacturing network system comprises corresponding identification, control and monitoring devices. The workpiece carriers that are movable along the assembly line can e.g., by tracked by said devices, whereby actual position, load, speed, etc., of each workpiece carrier is known in the network system.
The link between network system and the corresponding devices of the assembly line, e.g., for moving such a workpiece carrier, may be via Ethernet and by means of TCP/IP. The advantage is that corresponding network cards for industrial use already exist as a rule, that no additional hardware is needed, that there is a high transmission reliability and that the system is relatively inexpensive.
A workpiece carrier may e.g., be identified by a bar code.
To permit an efficiency analysis for optimizing process sequences and a selective evaluation of corresponding process data, the network computer may comprise an event database system consisting at least of database and database connection for collecting data. Furthermore, the use of such a database defines a global interface which can e.g., be queried by a relational database program, a structured query language, or the like.
The database connection can in particular connect database and a system visualization. The connection to the system visualization is through a DDE interface, the data being stored in the database via an ODBC or SQL connection. A database connection could e.g., regard the occurrence of errors in the system. For instance, if an emergency cut-off is operated in the system, this event would be reported via DDE to the network computer. Corresponding data are collected by the visualization, and information, such as error number, process data (pressure, temperature, or the like), etc. is displayed to the user. The user can now relate the error message with the actual cause of the error, e.g., operator in danger, missing packaging means, machine has a problem, etc. This error message is then recorded by the user and the corresponding data set is written into the database.
This applies by analogy to other events in the system, such as facility about to be cleaned, facility starts production, etc.
To further evaluate the data contained in the database of the network computer, the database may comprise a LAN, WAN, intranet connection, or the like, for querying said data. These data can then be transmitted to corresponding computers, or the like, and evaluated there.
On the basis of the data, production sequences and production planning can be optimized. Moreover, defects and reports can be collected in chronological order and e.g., transmitted to the producer of the corresponding plant components. Furthermore, with the event database system, all kinds of extensive recordings from the network system can be related with one another, and evaluations and planning tasks that are tailored to the respective company are possible.
According to the invention, all kinds of events can be recorded continuously by the network computer and its associated event database system, no specific configuration of the individual components being needed because of the network connection, and the various components being able to communicate with one another in a variable way via TCP/IP.
According to the invention an updated overview of the overall state of the network system with the components connected thereto and contained therein is possible, corresponding faults, or the like, being immediately noticeable and assignable. Furthermore, current information of the system on online planning is always available, a direct access to the database being possible. The system visualization is an image of the running process, whereby a clear overview and forward planning are possible.
On the whole, the manufacturing network system, in particular with the network computer and its event database system, permits a constant control of the various activities and processes and their efficiency. As a result, it is e.g., possible to assess the quality of the work or to plan the production capacity.
It is here of further advantage when a configuration tool for the graphic parameterization of the database connection is assigned to the event database system.
The efficiency of the manufacturing network system according to the invention can be improved in that the system visualization is connected to an article managing system and/or an order administration system for the purpose of data exchange.
Operation, in particular, of the network computer and its event database system can thereby be facilitated if the system visualization comprises a number of selection and/or display masks. With the help of such a selection mask, switching to further and detailed visualizations of the system is possible e.g., by clicking on specific symbols. Corresponding display masks can e.g., display actual states of various field devices, or the like, and said display masks can be called via a selection mask. It is thus possible to switch in each display mask to other display or selection masks via symbols.
The selection/display masks can be connected for data exchange and/or for calling corresponding software modules, or the like, to said modules. The connection may be via TCP/IP, HTTP, or the like.
Advantageous embodiments of the invention shall now be explained in more detail with reference to the figures attached to the drawing, in which:
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a block diagram of a manufacturing network system according to the invention;
FIG. 2 shows a second embodiment for a manufacturing network system according to the invention;
FIG. 3 shows a manufacturing network system according to FIG. 2 with additional input means;
FIG. 4 shows a network system by analogy with FIG. 2 with additional LAN connection;
FIG. 5 is a block diagram for illustrating the communication of a network computer with various software modules;
FIG. 6 is an illustration by means of a plant overview module as a software module;
FIG. 7 shows an input mask of a configuration tool of an event database system of the network computer;
FIG. 8 shows an input mask with different drop-down menus;
FIG. 9 shows an input mask for individualizing an error number;
FIG. 10 shows an embodiment of a system visualization;
FIG. 11 shows a pop-up submenu according to FIG. 10;
FIG. 12 shows a pop-up submenu according to FIG. 11;
FIG. 13 shows a pop-up submenu according to FIG. 12;
FIG. 14 shows a display mask for maintenance activities.
DESCRIPTION OF THE INVENTION
FIG. 1 is a block diagram showing a first embodiment of a manufacturing network system according to the invention. The network system comprises various levels. At the highest planning level, a master computer 2 is arranged that has access to a database 22 . Access takes place via SQL (structured query language).
At the next lower level of the network system, there is a network computer 3 . This computer communicates with the planning level and lower levels of the network system via protocols of the TCP/IP type. The network computer 3 in the illustrated embodiment comprises various software modules 6 , such as target order data module 14 , machine data acquisition module 11 , operating data acquisition module 12 , order administration module 34 , and quality management module 15 . The machine/operating data acquisition module 11 , 12 is connected via a DDE channel to a system visualization 27 of the network computer 3 . The target order data module 13 is directly connected via TPC/IP to the database 22 and the master computer 2 , respectively. On the other hand, there is a direct connection to the next lower level of the network system, i.e., the local level.
The system visualization 27 is also connected via TCP/IP to the order administration module 34 and the quality management module 15 . Said modules, in turn, are connected to a database 21 via TCP/IP. The database 21 contains actual data from production, for which the manufacturing network system 1 is responsible.
The quality management module 15 is connected to a further database 32 which may be part of the network computer 3 and may also be arranged externally relative thereto. The database 32 serves, for instance, to collect screwer data or other data of specific tools 39 that are used in production along an assembly line 38 or in work stations 40 in car manufacturing.
At the local level below the network computer 3 , there are arranged various local control devices 4 which communicate with one another and also with the system visualization 27 and the target order module 14 , respectively, via TCP/IP.
As a rule, the local control devices 4 comprise a computer 16 and a programmable control system 18 (SPS). The computer 16 comprises a touchscreen 17 via which, upon corresponding touching of symbols of the screen, the production assigned to the corresponding local control device 4 can be varied.
At the local level, there is also arranged, in particular, a further programmable control system as a master SPS. It serves data security in case of failure of a local control device.
A production level is additionally arranged below the local level; cf. FIG. 2 . The production level is connected via a bus system 19 , such as a Profibus, to the SPS 18 . At the production level, corresponding field devices 5 are arranged, e.g., initiators, actuators, screwer controls, or the like.
From the production level, corresponding data of the field devices 5 and of the work stations 40 screwers 39 or the like, connected to said devices can be transmitted to the local level and the components arranged thereat. The data are transmitted from there via TCP/IP to the higher levels.
It should here be noted that the software modules 6 shown in FIG. 1 can also be realized fully or in part at the planning level or the local level.
FIG. 2 shows the network computer 3 with an event database system 25 as a further embodiment of a manufacturing network system. At the lower local plane, the local control devices, i.e., computer 16 and SPS 18 , are arranged accordingly. A number of field devices 5 can be connected to each SPS via a bus system 19 . For the sake of simplification, FIG. 2 shows a corresponding production level only in connection with a local level.
FIG. 3 shows a further embodiment of a manufacturing network system 1 according to the invention. In addition to the embodiment shown in FIG. 2, an input means 23 is here arranged in the form of a computer with associated database 22 which communicates via TCP/IP with the local level and also with the network computer 3 . Via a query means 37 , the database 22 can also be called directly from the network computer 3 or from the computers of the local control device 4 .
With the input means 23 , it is e.g., possible to input data for maintenance pictures which can be converted both in the network computer 3 and the local computers into corresponding maintenance masks. The associated data are stored in the database 22 and can be queried from there cyclically via SQL, ODBC, or the like, and entered into the corresponding masks.
The communication between the various components of the network system may e.g., take place via Ethernet and TCP/IP. Corresponding network cards are already available for Ethernet and are relatively cheap. Ethernet is characterized by a very high transmission reliability.
FIG. 4 shows in detail the network computer 3 with its event database system 25 as a further embodiment of the manufacturing network system 1 . The event database system comprises a database which is e.g., realized by hard disks 26 and which has assigned thereto a configuration tool 29 , an evaluation tool 35 and a database connection 26 . The database connection 26 communicates via DDE (dynamic data exchange) with the system visualization 27 . The configuration tool 29 serves the graphic parameterization of the database connection, and the evaluation tool 34 serves to evaluate the data of the hard disks 36 .
For access to the event database system 25 , the network computer 3 is connected via LAN 28 to a number of further computers which evaluate the contents of the database of the network computer 3 by means of corresponding evaluation tools 35 .
Apart from LAN, the connection of the network computer 3 may also take place via WAN, intranet or extranet.
The event database system has several functions, such as support for optimizing the process sequence at the production level, parameterizing the reaction to occurring events, providing a global interface, targeted evaluation of the process data, or the like.
FIG. 5 shows the communication of the network computer 3 with various software modules 6 .
One of said software modules is a plant overview module 13 . Said module serves, for instance, to display operative states at the production level, to display position and movement of workpiece carriers, see FIG. 6, and to report on the status of various systems at the production level, such as transportation or assembly systems.
A further software module is the order administration module 34 . This module gives an overview of the orders to be handled as well as a day forecast and day review on the sequence of various orders and the automatic initiation, change and target control, for instance, of assembly orders along an assembly line in car production.
A further software module is the machine/operating data acquisition module 11 , 12 . Said module serves to detect faults, warnings, messages, operative modes, etc., which regard various machines at the production level and their operation. Moreover, it is possible to make a statement on the work load of the various machines, a statement on the logistics in connection with the various machines, etc.
Said software module and the remaining software modules are interconnected for data exchange, in particular via the network computer 3 , and are also connectable to corresponding output devices. Such output devices are e.g., screen, printer, modem, or the like. Data can be transmitted to external users via a modem, on condition that said users are authorized to access the manufacturing network system.
With a data archiving module 10 (filehandler) as a further software module, data are archived in connection with the running processes at the production level via users and via the system. The archived data are stored in a file. Stored are both an actual archive file and a predecessor to said actual archive file.
A logbook module 9 serves to provide versions, to store version updates, extensions or network failures.
The maintenance module 9 organizes repair or maintenance activities for the various machines, tools or work stations along the assembly lines. Repair can be effected through a corresponding message by the maintenance module. Moreover, confirmation after repair is also possible via the maintenance module. Finally, it is possible to call corresponding layout plans via output means from the maintenance module.
Further software modules 6 are a program diagnosis module 7 and the quality management module 15 (CAQ).
The program diagnosis module 7 serves, for instance, central programming and network diagnosis. A remote diagnosis is also possible through a corresponding connection of the program diagnosis module 7 via a modem, or the like.
The quality management module 15 serves to collect quality data, such as tightening torques of screwers, pressure data, temperature data, etc.
FIG. 6 gives an example of a plant overview which can be realized via the plant overview module 13 according to FIG. 5 . In this case a workpiece carrier 123 is arranged in a work station A 320 for working the workpiece disposed on the workpiece carrier. A further workpiece carrier 321 is already arranged in the working direction upstream of station A 320 .
FIG. 7 shows a selection mask 30 of the configuration tool 29 , see FIG. 4 . Said selection mask comprises eight individual masks with different input fields which are partly designed with drop-down menus. Switching to other masks is possible by corresponding selection buttons in the lower area of the selection mask, or specific actions, such as storing, terminating, etc., can be initiated.
FIG. 8 shows various selection masks for error individualization. Switching between the masks is possible by arrow symbols, and the various selection fields have drop-down menus.
From the left to the right in FIG. 8, the selection mask 30 is respectively shown with different drop-down menus.
FIG. 9 shows a further selection mask for the configuration tool 29 . In this instance, an error specification of the error number 102 is made through the selection mask.
FIG. 10 shows a start graphic of the system visualization 27 as a selection mask 30 with a number of symbol buttons. In selecting corresponding symbol buttons, it is possible to switch from the start graphic of the system visualization to subsequent masks, as is e.g., shown in FIGS. 11 to 14 .
For instance, the selection mask 30 according to FIG. 11 is called by selecting the symbol “station overview” on the start graphic. Various stations are there shown, which can be addressed and communicate by means of TCP/IP.
Display mask 31 according to FIG. 12 can e.g., be called by selecting one of the station buttons according to FIG. 11, here automatic station M 28 .
From the display mask according to FIG. 12, one proceeds to the display mask 31 according to FIG. 13 by selecting the symbol button “step sequence diagnosis”.
By analogy, a display mask 31 according to FIG. 14 can be called by selecting corresponding symbols on the start graphic according to FIG. 10; in said display mask specific maintenance work of a station M 28 is represented both with respect to the time needed and the person responsible for maintenance.
The function of the manufacturing network system according to the invention shall now be described in a few words.
With the network computer, it is made possible—in particular by providing the database assigned thereto and the various software modules optionally distributed in the network system—that process data can be queried via SQL or other database queries for selective evaluation. A global interface is defined, using the database, the interface being usable from all levels of the manufacturing network system. Optionally, access authorizations can be assigned accordingly both within the network system and for external users. The reaction to occurring events can be parameterized by using the network computer and the various input possibilities. Furthermore, an efficiency analysis can be made for optimizing the process sequence.
Various reactions to and effects on the various processes and the control thereof are possible with the manufacturing network system. Data acquisition is primarily possible via local control devices, network computers, etc. for analyzing the processes and their sequences and for optimizing the same. Faults and messages, in particular of the field devices and the local control devices, respectively, can be collected, evaluated and called in chronological order in an easy way. These and all of the further recordings within the manufacturing network system can be related with one another and permit specific evaluation and planning.
With the manufacturing network system according to the invention, a continuous recording of very different events is possible without any specific configuration of the network components and with a corresponding communication via TCP/IP. A group-wide use with corresponding extensions of and changes in the network system is possible in an easy way thanks to the general configuration of the manufacturing network system. | A manufacturing network system comprises at least one master computer and at least one network computer linked therewith for the purpose of network management. The network computer is linked with a number of local control devices in the area of assembly lines, work stations, or the like. The local control devices are associated with field devices, such as initiators, actuators, screw control modules, or the like, of which corresponding work devices are controllable and/or actuable along the assembly lines, in the work stations, or the like. The net server is provided with a number of software modules and/or is linked with software modules in the manufacturing network system for the purpose of data acquisition, management and/or evaluation. The system provides a manufacturing network system which facilitates collection, storage, management and evaluation of data in many ways, and which allows queries at almost any point of the network system. | 8 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation in part application of U.S. patent application Ser. No. 10/252,262, filed Sep. 23, 2002, which claims the benefit of U.S. Provisional Patent Application Ser. No. 60/410,375, filed Sep. 13, 2002, the disclosures of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The present invention relates generally to crosslinking compositions suitable, for example, to increase the strength (that is, wet and/or dry strength) of cellulosic products (including, for example, paper and other products made from cellulosic pulp) and to methods of increasing the strength of cellulosic products using such compositions.
[0003] For many years, the paper-making industry has sought ways of increasing the strength of paper. In that regard, papers fabricated without some additional means of reinforcement thereof can fall apart upon wetting or when subjected to mechanical stress in the dry state. Typically, a material is added to the wet pulp to improve the strength thereof during the formation of sheets prior to ultimate drying. Maintaining paper strength upon wetting is desirable in many applications, including bathroom tissue, paper towels, napkins, and the like. Moreover, additives which increase the strength of a wet paper often increase the dry strength of that paper. Increased dry strength is desirable, for example, in various packaging applications.
[0004] A number of wet- and dry-strength increasing additives are known in the art. However, such compositions typically include one or more components which are environmentally unfriendly or even toxic.
[0005] For example, some wet-strength additives are condensation products of urea and formaldehyde. Polyamine can be added to make such resins cationic. Other wet-strength additives include organochlorine crosslinked amidoamine compounds. A discussion of wet-strength additives and their mechanisms is presented in “The 65 Mechanism of Wet-Strength Development in Paper: A Review,” by Herbert H. ESPY, Tappi Journal, Vol. 78, No. 4, pages 90-97 (April 1995 as well as in “Chemistry of Paper Wet-Strength. I. A Survey of Mechanisms of WetStrength Development,” by Lars WESTFELT, Cellulose Chemistry and Technology, Vol. 13, pages 813-825 (1979), the contents of which are incorporated by reference as though set forth in full herein.
[0006] Chemical compositions purported to increase paper wet strength while being chemically benign or environmentally friendly are set forth in U.S. Pat. No. 6,146,497, which describes a composition including (a) a water-soluble polymeric material comprising at least one nucleophilic polymer, (b) a phenolic compound (phenols or polyphenols) and (c) a component (an oxidizing agent) capable of converting the phenolic compound into a quinone compound. Sugars in conjunction with their corresponding oxidases are contemplated as potential oxidizing agents for the phenolic component of the composition of U.S. Pat. No. 6,146,497. Many phenolic compound, however, are environmentally undesirable. Moreover, many oxidizing agents are also environmentally undesirable (for example, potassium dichromate and potassium permanganate).
[0007] It thus remains desirable to develop improved, environmentally friendly compositions for increasing paper wet and/or dry strength.
SUMMARY OF THE INVENTION
[0008] In one aspect, the present invention provides a composition comprising at least one hydrophilic polymer containing primary (—NH 2 ) and/or secondary (—NHR) amine groups (that is, hydrophilic polymer contains or includes at least two groups which are independently the same or different a primary amine group or a secondary amine group) and at least one saccharide containing a reducible function. In general, the R substituent upon the secondary amine is not limited. Strong electron withdrawing groups are not preferred as such groups can reduce the nucleophilic nature of the secondary amine. In many cases, R is an alkyl group. The amine groups can be pendant groups on the polymer or incorporated into the polymer backbone. In general, the hydrophilic polymer must include at least two amine groups (per a polymer chain) to enable crosslinking.
[0009] Such an amine functional polymer/reducible saccharide combination has been found to undergo an unexpected cross-linking reaction upon the application of heat. The compositions of the present invention can, for example, be used as cross-linking agents in paper strengthening applications. As used herein, the term “polymer” refers to a compound having multiple repeat units (or monomer units) and includes the term “oligomer,” which is a polymer that has only a few repeat units. The term polymer also includes copolymers which is a polymer including two or more dissimilar repeat units (including terpolymers—comprising three dissimilar repeat units—etc.). The polymers used in the compositions of the present invention can be homopolymers and/or copolymers.
[0010] Hydrogels have found use in the paper industry, for example, as absorbent materials. In that regard, hydrogels have been used as absorbent materials in diapers for a number of years. Surprisingly, the present inventors have discovered that the compositions of the present invention, which form hydrogels, can also be used to increase both the wet strength and dry strength of paper and other cellulosic products. While the hydrophilic polymers of the present invention form hydrogels with reducing sugars in aqueous solution, cross-linking can be controlled (for example, by control of temperature as described below) allowing application of the hydrophilic polymer and the saccharide to wet pulp (that is, paper or cellulosic fibers) and binding to the pulp prior to substantial cross-linking. Typically, a pre-formed hydrogel would not be able to effectively bind to cellulosic fibers as a result of its high viscosity.
[0011] Polymers suitable for use in the present invention include, but are not limited to, partially hydrolyzed poly(N-vinylformamide) (that is, a copolymer of NVF and vinylamine), partially hydrolyzed vinyl acetate/NVF copolymer (that is, a polymer with vinyl acetate, vinyl alcohol, NVF and vinylamine repeat units); hydrolyzed acrylonitrile/NVF copolymer; (available as a commercial product from Mitsubishi and containing acrylonitrile, acrylamide, amidine, NVF and vinylamine units), amine functional polyacrylamide (for example, prepared via Hoffman degradation of polyacrylamide), acrylic acid/vinylamine copolymer, maleic anhydride/maleic acid copolymers with NVF/vinylamine, NVF/vinylamine polymers with vinyl sulfonate comonomer units, NVF/vinylamine copolymers with cationic monomers such as diallyldimethylammonium chloride and/or cationic acrylate comonomers, allylamine/diallylamine polymers and copolymers, urea/formaldehyde and melamine/formaldehyde condensation polymers, amidoamine polymers (prepared from dicarboxylic acids and polyfunctional amines), amine/epichlorohydrin polymers, poly(ethyleneimine), and hydrolyzed or partially hydrolyzed poly(2-alkyl-2-oxazoline). One hydrophilic polymer or a mixture of two or more such polymers can be used in compositions of the present invention.
[0012] In general, polymers having a broad range of number average molecular weight (M w ) are suitable for use in the present invention. Preferably, the molecular weight of the polymers is at least approximately 500. More preferably, the molecular weight is in the range of approximately 30,000 to approximately 100,000. Polymers having molecular weight in excess of 100,000 can be used, but water solubility can decrease for such polymers as molecular weight increases beyond approximately 100,000.
[0013] The reducible saccharides used in the present invention can be monosaccharides, disaccharides, trisaccharides etc, (for example, sugars) or polysaccharides (for example, starch or cellulose). Polysaccharides are typically a combination of nine or more monosaccharides. Reducible saccharides or reducing saccharides include a reducing group, function or functionality which is typically an aldehyde group (—C(O)H) or a hemiacetal group
which is another form of an aldehyde when the saccharide is in a cyclic conformation. Examples of reducing saccharides suitable for use in the present invention include, but are not limited to, the sugars glucose, lactose, and 2-deoxy-D-ribose. To decrease costs, the saccharide is preferably a monosaccharide (for example, glucose), a disaccharide (for example, lactose) or a polysaccharide (for example, starch).
[0014] The composition can, for example, further include a base. Examples of suitable bases include, but are not limited to, sodium hydroxide, potassium hydroxide, ammonia or calcium carbonate.
[0015] In one embodiment, the polymer is a copolymer of vinyl amine and vinyl alcohol. Preferably, the copolymer is at least 0.5% by weight of vinyl amine. More preferably, the copolymer is at least 3% by weight of vinyl amine. Even more preferably, the copolymer is at least 6% by weight of vinyl amine. Copolymers having well in excess of 6% by weight of vinyl amine are suitable for use in the present invention. In several embodiments for example, copolymer can be at least 12% by weight of vinyl amine.
[0016] A broad range of mole ratios of amine to reducing saccharide is suitable for use in the present invention. In one embodiment, the mole ratio of amine groups to reducing saccharide is in the range of approximately 1:4 to approximately 8:1. More preferably, the mole ratio of amine groups to reducing saccharide is in the range of approximately 1:2 to approximately 8:1. In general, increasing amine content results in stiffening of the resultant gel. One skilled in the art can readily determine an appropriate amine content for a desired set of properties for the resultant gel.
[0017] In another aspect, the present invention provides a composition including water; at least one hydrophilic polymer containing at least two groups which are independently the same or different a primary amine group or a secondary amine group and at least one saccharide containing a reducible function as described above. In this aspect of the present invention, the hydrophilic polymer and the saccharide are mixed to form a reaction mixture and reacted (that is, crosslinked) until or so that the viscosity of the composition increases. The crosslinking reaction is then substantially terminated (prior to completion) by reducing the pH of the composition (for example, by adding an acid such a aqueous hydrochloric acid). The viscosity of the composition can, for example, be at least 20 cp at 80° C. when the crosslinking reaction is terminated. In one embodiment, the viscosity of the composition is in the range of approximately 20 cp to 100 cp at 80° C. when the reaction is terminated. The viscosity of the composition can further, be in the range of approximately 20 cp to 60 cp at 80° C. when the reaction is terminated. The viscosity of the composition can also be in the range of approximately 20 cp to 40 cp at 80° C. when the reaction is terminate. Preferably, the viscosity of the reduced pH composition is no greater than 80 cp at room temperature (that is, approximately 22° C.).
[0018] The pH of the composition can, for example, be greater than 7 during reaction and reduced to less than 7 to substantially terminate the reaction. Preferably, the pH of the composition is at least 10 (and, more preferably, in the range of approximately 10 to 12) during reaction and reduced to 6 or less to substantially terminate the reaction. In one embodiment, the pH of the composition is reduced to a pH in the range of approximately 4 to 6 to substantially terminate the reaction. In another embodiment, the pH of the composition is reduced to a pH in the range of approximately 5 to 6 to substantially terminate the reaction. The compositions of the present invention can be stored for extended periods of time at a pH of 6 or less (and, for example, at room temperature) prior to causing further crosslinking (for example, in the strengthening of paper).
[0019] In another aspect, the present invention provides a method of increasing the strength of a cellulosic product including the step of contacting a wet cellulosic pulp with a composition as described above. In one embodiment, wet cellulosic pulp (for example, wet paper pulp) and the composition are contacted at a temperature below approximately 50° C., or more typically, at room temperature or below (that is, at approximately 25° C. or below) and subsequently heated to induce cross-linking. For example, the cellulosic pulp and the composition can be heated to a temperature of at least 50°, at least 70° or at least 90°.
[0020] In still a further aspect, the present invention provides a method of increasing the strength of a cellulosic pulp product including the steps of: contacting wet cellulosic pulp with a composition comprising (i) at least one hydrophilic polymer containing at least two groups which are independently the same or different a primary amine group or a secondary amine group and at least one saccharide containing a reducible function, the hydrophilic polymer and the saccharide of the composition having been reacted in a crosslinking reaction prior to contacting the composition with the cellulosic pulp product to increase the viscosity the composition; and, after contacting the cellulosic pulp with the composition, causing the crosslinking reaction between the hydrophilic polymer and the saccharide of the composition to proceed further.
[0021] In one embodiment, prior to contacting the wet cellulosic pulp with the composition, the hydrophilic polymer and the saccharide are mixed to form a reaction mixture and reacted (that is, crosslinked) until the viscosity of the composition increases. The reaction is then substantially terminated by reducing the pH of the composition as described above. Upon addition of such compositions to wet cellulosic pulp, a further crosslinking (and a resultant further increase in viscosity) is promoted by a basic environment and heating. After addition of the composition to the wet cellulosic pulp and further crosslinking, the wet cellulosic pulp is dried to form a cellulosic pulp product (for example, paper, tissue, cardboard etc.).
[0022] In still another aspect, the present invention provides a composition formed from a mixture of water, cellulosic pulp, at least one hydrophilic polymer containing at least two groups which are independently the same or different a primary amine group or a secondary amine group and at least one saccharide containing a reducible function.
[0023] The compositions and methods of the present invention substantially increase both the wet and dry strength of paper and other cellulosic products. The compositions can also be used as, for example, strengthening additives in other materials. The compositions of the present invention can be added to the cellulosic fibers as individual components or as a pre-gel made by the partial reaction of the polymer(s) or copolymer(s) and the reducible saccharide component(s). No oxidizing agents, phenolic compounds, formaldehyde or organohalo compounds are required in the compositions and methods of the present invention. In general, no environmentally undesirable components are used in the compositions and methods of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] FIG. 1 illustrates a study of gel time at various temperatures for a composition including a copolymer of vinyl amine and vinyl alcohol (6 wt % vinyl amine) and D-glucose at a 1:1 sugar/copolymer ratio.
[0025] FIG. 2 illustrates the effect of addition of base upon gel time.
[0026] FIG. 3 illustrates a study of gel time at various sugar:copolymer ratios for a composition including a copolymer of vinyl amine and vinyl alcohol and D-glucose.
[0027] FIG. 4 illustrates a study of gel time at various sugar:copolymer ratios for a composition including a copolymer of vinyl amine and vinyl alcohol and lactose.
[0028] FIG. 5 illustrates the viscosity of a composition including a copolymer of vinyl amine and vinyl alcohol (6 wt % vinyl amine) and D-glucose at a 1:1 sugar/copolymer ratio as a function of time.
[0029] FIG. 6 sets forth a schematic representation of a Maillard reaction.
DETAILED DESCRIPTION OF THE INVENTION
[0030] As discussed above, during paper processing, material is added to the wet pulp to improve the strength during the formation of sheets prior to ultimate drying. Preferably, the additive material or composition exhibits a relatively low viscosity during addition (to fully absorb into the pulp), then cures as temperature increases. Because paper comes into intimate contact with people, the strength-enhancing material is preferably relatively environmentally benign.
[0031] In the present invention, environmentally friendly or benign compositions are used to increase the wet strength (as well as the dry strength) of paper. When individual polymer chains interact, chemical or physical crosslinking may occur. This crosslinking results in a three-dimensional highly branched network of polymers.
[0032] When these networks become swollen with water they form hydrophilic gels, known as hydrogels. Hydrogels possess unique physical properties having attributes of both solids and liquids. Solid-like properties can be attributed to the strength of the crosslinked polymer networks. Whereas, fluid like properties result from the fact that the hydrogel is typically composed of over 80% water. The dual nature of their physical properties makes hydrogels particularly interesting and useful, in both industry and research.
[0033] The present inventors have discovered that water soluble polymers having primary and/or secondary amine groups undergo a crosslinking reaction in the presence of a reducing saccharide such as a reducing sugar. Reducing sugars are sometimes referred to herein simply as sugars.
[0034] Several examples of the present invention are described using compositions including polymers with vinyl amine repeat groups and at least one of several reducing sugars. Vinyl amine homopolymer was found to form crosslinked polymer networks or gels in the presence of a reducing sugar. Moreover, copolymers of vinyl amine and at least one other monomer were also found to form crosslinked polymer networks or gels in the presence of a reducing sugar. In many instances, use of a copolymer of vinyl amine and at least one other monomer is preferable to use of a vinyl amine homopolymer in the present invention given the expense of the vinyl amine monomer. In a number of studies of the present invention, representative copolymers of vinyl amine and vinyl alcohol were used. Such copolymers are also sometimes referred to herein as poly(vinylalcohol)/poly(vinylamine) or PVOH/PVAm copolymers.
[0035] Aqueous solutions of poly(vinylalcohol)/poly(vinylamine) copolymer and a number of sugars were found to gel readily at temperatures between approximately 50 and 100° C. In a series of initial experiments, known amounts of sugars were mixed with a copolymer of vinyl amine and vinyl alcohol (12 wt % vinyl amine) to form a 40% solution (in water) by weight. The mixtures were heated to various temperatures and held for varying lengths of time. Gelation was determined to be the point where a Teflon stir bar ceased to move.
[0036] Vinyl amine is required for gelation to occur. In that regard, homopolymers of vinyl alcohol did not gel in the presence of sugar at elevated temperature. Homopolymers of vinyl amine or copolymers of vinyl amine and vinyl alcohol gelled readily under these conditions. Reducing saccharide (for example, sugar) is also required for gelation—vinyl amine homopolymers and copolymers of vinyl amine and vinyl alcohol did not gel without the presence of sugar. Gelation occurs over a wide range of amine: sugar (saccharide) ratios.
[0037] Gelation occurred in the presence of 2-deoxy-D-ribose, suggesting that the osazone mechanism was not responsible for crosslinking. On the other hand, gelation did not occur when using sucrose, suggesting that Maillard chemistry (known from food chemistry) is involved in the crosslinking and hence gelation. Prior studies suggest that no mutagenicity results from products of the Maillard reaction when disaccharides are employed. Lactose, for example, allows for gelation in the compositions and systems of the present invention. Although it is believed that the Maillard chemistry is involved in gelation in the compositions of the present invention, the present invention is not limited to any particular mechanism of gelation.
[0038] Increasing temperature increases the rate of the reaction/gelation. In several experiments with a 12% (wt) amine sample, for example, the time for gelation dropped with increasing temperature from 335 minutes (50° C.) to 113 minutes (60° C.) to 50 minutes (70° C.) to 24 minutes (80° C.) to less than 10 minutes at (90° C.). FIG. 1 illustrates graphically the effect of increasing temperature on gel time for a copolymer of vinyl amine and vinyl alcohol having 6% (wt) vinyl amine. Addition of acid (for example, H 2 SO 4 ) slowed the gelation reaction, while addition of a base (for example, NaOH) accelerated the gelation reaction (see FIG. 2 ).
[0039] FIGS. 3 and 4 illustrate studies of the effect of mole ratio of sugar to copolymer (6% by weight amine) for D-glucose and lactose, respectively. In general, sugar concentration only slightly effected gel time. Moreover, the type of sugar used did not greatly affect gelation time. Lactose was found to be slightly better than D-glucose in these studies.
[0040] A number of experiments were performed to explore the ability of the gel to strengthen wet paper, as summarized below. The PVOH/PVAm:glucose 2:1 sample clearly showed improved wet strength over PVOH/PVAm without sugar and is substantially superior to the control paper and to glucose coated paper. These results demonstrate the effectiveness of the compositions of the present invention in improving the wet strength and the dry strength of paper. The temperature dependence of the rate of cross-linking of the compositions of the present invention allows time to apply the relatively low-viscosity mixtures of hydrophilic polymer and reducing saccharide of the present invention to pulp fibers, with strength properties developing in the finished sheet. Dehydration readily occurs in the paper sheet upon drying to form a strengthening cross-linked matrix.
[0041] In the experiments of Tables 1 and 2, a sample of PVOH/PVAm (12 wt % vinyl amine; medium molecular weight) was dissolved at 4 wt % in distilled water. A sample of glucose was also dissolved at 4 wt % in distilled water. These samples were applied to Whatman #4 filter paper to provide even coverage.
TABLE 1 Dry Result Coat Weight (weight of coating/ Dry Strength Sample Description weight of paper) (lbs) Control Paper 0 5.43 PVOH/PVAm 0.124 15.3 Glucose 0.137 4.1 PVOH/PVAm:glucose 2:1 0.118 11.7
[0042]
TABLE 2
Wet Results
Coat Weight
(weight of coating/
Wet Strength
Sample Description
weight of paper)
(lbs.)
Control Paper
0
0.095
PVOH/PVAm
0.085
0.81
Glucose
0.134
0.128
PVOH/PVAm:glucose
0.081
3.26
[0043] In several other experiments, a sample of PVOH/VAm (12 mole % vinyl amine repeat units) was dissolved at 6 wt % in distilled water. In these experiments, the composition including the hydrophilic polymer PVOH/PVAm and a reducing sugar (for example, D-glucose) was reacted prior to contact with a wet cellulosic pulp to first increase the viscosity of the composition. Increasing the viscosity of the composition can, for example, result in better binding of the composition to the wet cellulosic pulp. The crosslinking reaction can be terminated prior to completion by, for example, reducing the pH of the composition through the addition of an acid. Preferably, the pH of the composition is reduced to a pH in the range of 4 to 6. It was discovered that, the compositions of the present invention can be stored for extended periods of time at a pH of 6 or less without substantial further crosslinking reaction. Upon addition of such compositions to wet cellulosic pulp, a further crosslinking (and a resultant further increase in viscosity) is promoted by a basic environment and heating. The compositions of the present invention can, for example, be added to wet cellulosic pulp in the range of approximately 0.05 to 2 wt % on the basis of the weight dry cellulosic pulp. The compositions of the present invention can also be added in the range of approximately 0.1 to 1 wt % based upon the weight of the dry cellulosic pulp. The compositions of the present invention can further be added in the range of approximately 0.1 to 0.5 wt % based upon the weight of the dry cellulosic pulp.
EXPERIMENTAL
[0044] Materials. All chemicals were used without further purification. Poly(vinylalcohol) (98-99%, M w 31,000-50,000), D-glucose (A.C.S. reagent) and 2-deoxy-D-ribose (97%) were purchased from Aldrich Chemical Co. Sucrose (A.C.S. reagent) was purchased from J. T. Baker Chemical. Lactose (A.C.S. reagent) was purchased from E.M. Science. L-ribose (99.5%) was purchased from Acros Organics. The poly(vinylalcohol)/poly(vinylamine) copolymers (6 and 12% amine, medium M w ) were donated by Air Products and Chemicals Inc.
[0045] Instrumentation. Infrared spectra (IR) were obtained on an ATI Mattson FTIR spectrometer. Information obtained was used to determine chemical changes occurring during gelation.
[0046] Synthesis of poly(vinylamine). Poly(vinylamine) was synthesized using N-vinyl formamide (NVF). First poly(vinylformamide) (PNVF) was made by combining 100 mL of the NVF monomer, 40 mL of DMSO solvent, 61 mg Vazo 88 initiator (cyclohexane carbonitrile), and 0.5 g RAFT agent in a three-neck flask. The mixture was then heated at 100° C. for ˜2 hours under nitrogen gas with constant stirring and with reflux conditions. After heating, the product was diluted in a 50 mL/50 mL water/ethanol mixture. The product was then precipitated out of solution using acetone. Product was dried overnight in a vacuum oven, redisolved in a 120 mL/50 mL water/ethanol mixture and subsequently precipitated using acetone. The PNVF was hydrolyzed under basic conditions by combining the polymer, concentrated NaOH (5% excess) and distilled deionized water in a round bottom flask. The mixture was then heated at 80° C. for 18 hours, under reflux conditions and with constant stirring. Adding HCl to the cold product solution precipitated the product. The product was then washed with methanol three times and dried in a vacuum oven. HCl was removed by adding aqueous NaOH. This product was precipitated in acetone, dried and then washed with butanol.
EXAMPLES
Example 1
[0047] An aqueous solution was prepared by dissolving 7.5 g D-glucose and 2.5 g poly(vinylalcohol) (PVOH) into distilled, deionized water in a 25 mL volumetric flask. The solution was clear with some undissolved polymer. It was, however, pourable. The solution was transferred to a round bottom flask and heated to 80° C. in an oil bath. Heating was done with constant stirring and under reflux conditions. Upon completion the solution remained clear with all polymer dissolved and was still pourable.
Example 2
[0048] Prior studies suggest that an aqueous solution of PVOH and D-glucose could be used to form hydrogels by using freezing/thawing cycles. See Yamaura, K.; Fukada, M.; Tanaka, T.; Tanigami, T. J. of Applied Polymer Science. 1999, 74, 1298-1303. To study this effect, a solution was prepared as in example 1. Heating was carried out using the same procedure as in example 1, but was allowed to reach a temperature of 90° C. The aqueous solution was then placed in a −10° C. freezer over 48 hours. After thawing the solution at room temperature for 1 hour a weak, white hydrogel had formed. The gel was then placed back in the freezer for 24 hours and then thawed at room temperature for 1 hour. After which, the gel appeared visibly stronger. This gel was found to be soluble in water heated up to 49° C. Neither swelling nor dissolution was noted when placed in 1M HCl.
Example 3
[0049] Prior studies further suggest that D-glucose was not necessary for the gelation of poly(vinylalcohol) using the process in example 2. See Yamaura, K.; Karasawa, K. I.; Tanigami, T.; Matsuzawa, S. J. of Applied Polymer Science. 1994, 51, 2041-2046. To study such gelation, a 2.5 g of PVOH was dissolved in distilled, deionized water in a 25 mL volumetric flask. Heating was carried out using the same procedure as in example 1, but was allowed to reach a temperature of 95° C. The solution was then placed in the freezer at −25° C. for 48 hours. After 1 hour of thawing at room temperature a gel, similar in appearance to the gel in Example 2, was produced. The inability of PVOH to form hydrogels without the freezing/thawing cycle indicated that the amine groups on copolymers of PVOH and Poly(vinylamine) in the compositions of the present invention are responsible for gelation.
Example 4
[0050] Poly(vinylamine) (PVA) was also used in trying to make gels. An excess of PVA was used in the case that some butanol was still present in the synthesized polymer. 2.8 g of PVA was dissolved in distilled, deionized water in 25 mL volumetric glassware leaving room for the addition of D-glucose and more water. A heating gun was used, as needed, to dissolve polymer. D-glucose was dissolved in some water in a separate container, added to the other solution and diluted as necessary. This solution was orange in color and pourable. Heating was carried out using the same procedure as in example 1, but was allowed to reach a temperature of 100° C. A rubbery, dark brown gel began to appear at −95° C. This gel swelled when exposed to both excess water and 1M HCl.
Example 5
[0051] To ensure that the discoloration observed in Example 4 was a result of gelation and not merely oxidation of the amine, Example 4 was repeated under nitrogen gas. This was done using a three neck flask, rubber septum and needle. The rubbery, dark brown gel appeared at ˜93° C. again. This gel was slightly lighter in color than the gel of Example 5. This gel swelled in water and in 1M HCl.
Example 6
[0052] To study whether a sugar was necessary for gelation, 1.25 g of PVA was dissolved in water in a 25 mL volumetric flask. This solution was then heated to 95° C. using the procedure of Example 1. No gelation was observed.
Example 7
[0053] The poly(vinylalcohol)/poly(vinylamine) copolymer that was used for the experiments set forth in Examples 7 through 24 contained 12% amine groups. 2.5 g of the copolymer followed by 7.5 g of D-glucose were dissolved in distilled deionized water using the procedure outlined in Example 4. This solution was then transferred to a three-neck flask and heated in an oil bath to 100° C. Heating was carried out under reflux conditions, with constant stirring and under argon gas. A strong, bright yellow gel appeared at ˜90° C. This gel swelled when exposed to excess water and to 1M HCl.
Example 8
[0054] The procedure in example 7 was repeated using 2.5 g D-glucose. This is a 1:2 mole ratio of amine groups to sugar molecules. Gelation began to occur at −90° C. This gel was strong and yellow. It swelled in water and 1M HCl.
Example 9
[0055] The procedure of Example 7 was repeated using 1.25 g D-glucose (a 1:1 mole ratio of amine groups to sugar molecules). Gelation began to occur at ˜90° C. This gel was a pale yellow color. This gel is still strong but not as strong as the previous two examples. Swelling was noted in water and 1M HCl. IR spectra were taken of the aqueous solution before heating and of this gel afterwards. Before heating a strong peak was seen around 1680 cm −1 , which is typical of a primary amine peak. After heating this peak became much smaller, more typical of a secondary amine. Another unidentified peak appeared after heating at ˜1090 cm −1 .
Example 10
[0056] The procedure of Example 7 was repeated using 0.61 g D-glucose (a 2:1 mole ratio of amine groups to sugar molecules). Gelation began to occur at ˜95° C. This gel was strong yet somewhat sticky and a clear yellow color. Swelling was noted when exposed to water and to 1M HCl.
Example 11
[0057] The procedure of Example 7 was repeated using 0.31 g D-glucose (a 4:1 mole ratio of amine groups to sugar molecules). Gelation began to occur at ˜100° C. The gel produced was sticky and almost clear in color. This gel swelled when exposed to excess water and to 1M HCl.
Example 12
[0058] The procedure of Example 7 was repeated using 0.16 g D-glucose (a 8:1 mole ratio of amine groups to sugar molecules). Gelation began to occur at ˜100° C. This gel was sticky and clear. Swelling occurred when exposed to water and to 1M HCl.
Example 13
[0059] To test for the possibility of an osazone mechanism L-ribose was used instead of D-glucose. The procedure followed was similar to that of example 9 (using a 1:1 mole ratio and the same conditions). 1.02 g of L-ribose was used. Gelation occurred at ˜85° C. This gel was strong, sticky and bright orange in color. This gel swelled when exposed to excess water and to 1M HCl.
Example 14
[0060] As part of the aforementioned test of reaction mechanism 2-deoxy-D-ribose was also used instead of D-glucose. The procedure of Example 9 was once again followed, this time using 0.91 g of 2-deoxy-D-ribose. Gelation occurred at 85° C. This gel was also strong and bright orange. The gelation of 2-deoxy-D-ribose indicates that the osazone reaction is not taking place since it would be unable to occur as a result of the structure of this sugar. Without limitation to any particular reaction mechanism in the present invention, a Maillard reaction mechanism is thus indicated. The gel of this example swelled when exposed to excess water and to 1M HCl.
Example 15
[0061] Prior studies show that little or no mutagenicity results from the Maillard reaction when disaccharides, such as lactose, are involved. See, for example, Brands, C. M. J.; Alink, G. M.; vanBoekel, M. A. J. S.; Jongen, W. M. F. J. Agric. Food Chem. 2000, 48, 2271-2275. A summary of the Maillard reaction is provided in FIG. 6 . Thus lactose is a good sugar for use in the present invention. The procedure of Example 9 was used, with 2.45 g of lactose. A strong, orange gel formed at 100° C. Solubility tests were not carried out on this gel.
Example 16
[0062] Sucrose is a disaccharide lacking active carbonyl groups. Therefore, sucrose would not be able to form a gel via the Maillard reaction. See Baynes, J. W.; Monnier, V. M. “The Maillard Reaction in Aging, Diabetes and Nutrition” 1989; and O'Brien, J.; Nursten, H. E.; Crabbe, M. J. C.; Ames, J. M. “The Maillard Reaction in Foods and Medicine” 1998. The procedure from example 9 was once again repeated. In this example, time 2.33 g of sucrose was used. The temperature was taken up to 115° C. and gelation was not observed.
Example 17
[0063] Constant temperature experiments were also carried out. 2.5 g of copolymer followed by 1.25 g of D-glucose were dissolved in water using a 25 mL volumetric flask as outlined in Example 4. Heating took place in an oil bath that was maintained at a constant temperature of 80° C. Heating was done under reflux conditions, under argon gas and with constant stirring. Gelation time was noted as the time when the gel became too viscous for the stir bar to move. In this example gelation time was found to be 23.5 minutes. The gel produced was a clear yellow and sticky. This gel dissolved in water.
Example 18
[0064] The procedure of Example 17 was repeated using an oil bath at 70° C. Gelation time was noted as 49.5 minutes. This gel was weaker and stickier than the previous one. This gel also dissolved in water.
Example 19
[0065] The procedure of Example 17 was repeated using an oil bath at 60° C. Gelation time was noted as 113.25 minutes. This gel was weaker and stickier than the previous one. This gel also dissolved in water.
Example 20
[0066] The procedure of Example 17 was repeated using an oil bath at 50° C. Gelation time was noted as 335.0 minutes. This gel was weaker and stickier than the previous one. This gel also dissolved in water.
Example 21
[0067] To test the effect of pH on gelation, the procedure of Example 17 was repeated under acidic conditions. Three drops of concentrated H 2 SO 4 were added to the aqueous solution. After 120.0 minutes the solution had turned slightly yellow and appeared to be a pourable gel. This gel was also soluble in water.
Example 22
[0068] Basic conditions were also examined using the procedure in example 17. 0.04 g of concentrated NaOH were added to the aqueous solution. Gelation was noted after 18.2 minutes. This gel was similar in appearance to that produced in Example 17. This gel was slightly soluble in excess water.
Example 23
[0069] The gels studied in FIGS. 1 through 5 were synthesized in a consistent manner. In that regard, 21.25 grams of copolymer was weighed out into a beaker and set aside for both 6 wt % and 12 wt % amine copolymers. The sugar was also weighed out in a beaker and set aside. The amount of sugar added depended on the mole ratio of sugar to amine, which is indicated in Table 3 below for each ratio.
TABLE 3 Molar Ratio (sugar:amine) And Type of Sugar Amount of Sugar (grams) 1:1 glucose 5.23 2:1 glucose 10.46 4:1 glucose 20.92 1:2 lactose 5.23 1:1 lactose 10.46 2:1 lactose 20.92
The saccharide (sugar):amine rations set forth in Table 3 and FIGS. 3 and 4 are merely the reciprocal of amine:sugar mole ratios.
[0070] Deionized water was measured out in a tall form beaker to approximately 425 mL. A small amount (˜¼) of this water was put into another tall form beaker and the sugar was added and mixed thoroughly. The bulk of the water was used to mix with the copolymer. The mixture of copolymer/water was then put into an oil bath and mixed to allow the copolymer to dissolve. Next, the sugar/water mixture was added into the copolymer mixture and the time was started. The UL adapter was then lowered into the mixture and the Brookfield viscometer was turned on to a speed of 60 (The Brookfield viscometer had been earlier calibrated with water). The readings form the Brookfield were not recorded until after the time had reached 9 minutes to allow the UL adapter to settle. The time was then recorded after each minute. The only other change in procedure occurred when the NaOH was added [50% (w/w/) NaOH in water solution]. 31 mM of NaOH (or 1 gram of the NaOH in water solution) was added into the sugar/water mixture before adding it to the copolymer mixture.
Example 24
[0071] In several studies of the effect of the compositions of the present invention upon wet and dry strength of paper, a sample of PVOH/PVAm (12 wt % VAm; medium molecular weight) was dissolved at 4 wt % in distilled water. A sample of glucose was also dissolved at 4 wt % in distilled water. These samples were applied to Whatman #4 filter paper from a 6″ roll using a wire wound rod (RDS40) to provide even coverage. 50 grams of the 4 wt % solution of PVOH/PVAm were mixed with 25 grams of the 4 wt % solution of glucose and also coated on the above noted filter paper using a wire wound rod to provide even coverage. The samples were placed in an air circulating oven for 10 minutes at 100° C. The samples were removed and conditioned at 23° C.; 50°/″ RH for 16 hours prior to testing. 1″ wide strips were cut transverse to the filter paper roll direction and cut into two 3″ long specimens for dry tensile testing. Samples were also cut into 3″ long specimens and immersed in water for 30 seconds and tested for wet tensile strength. The results are set forth in Table 1 and 2 above. The sample weights were measured to determine coat weights (amount of additive on the coated paper versus the uncoated paper). Data on an average of four specimens is set forth in Tables 1 and 2. The testing rate was 2 in./min. strain rate (2 in. gage length).
Example 25
[0072] The polymer used in this example and the following examples was a copolymer of vinyl alcohol and vinylamine (PVOH/VAm), containing 12 mole % vinylamine repeat units, with a medium molecular weight. Although any reducing sugar may be used, D-glucose was used in this and the following examples. Twelve (12) grams of PVOH/VAm were dissolved in 200 grams of water. The solution was heated to 90° C. and then filtered to remove any insoluble material. With the solution temperature maintained at 80° C., six grams of D-glucose was added, followed by sufficient 30% sodium hydroxide solution to bring the solution pH to at least 10, preferably approximately 12. With continued heating in the 80-90° C. range the solution converts to a thick viscous gel. The relationship between time to gelation and temperature is illustrated in Table 4 for the crosslinking of PVOH/VAm with D-glucose at a 1:1 mole ratio and a pH of 12.5.
TABLE 4 Temperature (° C.) Time to gelation 22 66 hours 30 28 hours 40 22 hours 50 5 hours 60 40 minutes 80 10-20 minutes
Example 26
[0073] As in Example 25, twelve grams of PVOH/VAm were dissolved in 200 grams of water, heated to 90° C. and filtered to remove insoluble material. Maintaining the solution temperature at 80° C., six grams of D-glucose were added, followed by sufficient 30% aqueous sodium hydroxide to bring the solution pH to at least 10. The initial viscosity was 17 cps. After approximately twenty minutes at 80° C., the viscosity had risen to 40 cps. Once the viscosity reached 40 cps, the solution pH was adjusted to 6 by addition of 33% hydrochloric acid solution. The viscosity was measured as 22 cps at 80° C. and 80 cps at 23° C. The solution does not gel and can be stored at room temperature for several weeks without any evidence of gel formation.
Example 27
[0074] A dynamic handsheet maker (Techpap) was employed to make paper samples for testing. Sixteen (16) grams of dry cellulosic fiber were used to make a slurry in water at 1% consistency. The pH of the slurry was adjusted to the desired level and the acid-stabilized PVOH/VAm/D-glucose from Example 26 added at a level of 0.5 weight % (equivalent to 10 lb/ton) based on the amount of dry fiber in the slurry. The rotation speed of the handsheet maker was set at 680 rpm and pressure applied to form the paper sheet. The wet paper web was pressed and dried at 115° C. for eight minutes. The paper sheets were conditioned at 23° C. and 50% relative humidity for one day. The treated paper sheets were then tested for wet tensile, dry tensile and burst strength using standard tests. The results were normalized to allow for differences in thickness and grammage for each sheet.
Example 28
[0075] Paper sheets were made up as in Example 27, both with and without the polymer additive. The PVOH/VAm/D-glucose solution was heated for 30 minutes at 80° C. before adding to the fiber suspension. The final viscosity (at room temperature) was 80 cps. The results are summarized in Table 5.
TABLE 5 Additive None PVOH/VAm/D-glucose pH 5.5 5.5 DBL (km) 3.646 4.173 WBL (km) 0.054 0.332 WBL/DBL (%) 1.5 8.00
In Table 5, “DBL” refers to Dry breaking length, while “WBL” refers to Wet breaking length
Example 29
[0076] Paper sheets were made as in Example 27, using the PVOH/VAm both with and without added D-glucose. The copolymer/glucose solution was heated at 80° C. for 30 minutes before use and the final viscosity at room temperature was 68 cps. The results are summarized Table 6.
TABLE 6 Additive None PVOH/VAm PVOH/VAm/D-glucose pH 5.5 8 8 DBL (km) 3.646 3.934 3.912 WBL (km) 0.054 0.326 0.361 WBL/DBL (%) 1.50 8.30 9.20
Example 30
[0077] Paper sheets were made as in Example 27, both with and without polymer additive. The PVOH/VAm/D-glucose was heated at 80° C. until a final viscosity of 225 cps (as measured at room temperature) was reached. The results are summarized in Table 7.
TABLE 7 Additive None PVOH/VAm/D-glucose pH 5.5 5.5 DBL (km) 3.646 4.39 WBL (km) 0.054 0.352 WBL/DBL (%) 1.50 8.01
Example 31
[0078] Paper sheets were made as in Example 27, both with and without polymer additive. The PVOH/VAm/D-glucose samples were heated for different times at 60° C. prior to use. The results are summarized in Table 8.
TABLE 8 PVOH/ PVOH/ PVOH/ VAm/D- VAm/D- VAm/D- Additive None glucose glucose glucose Reaction — 12 22 33 Time (mins) Viscosity (cps) — 53 71 83 pH 5.5 5.5 5.5 5.5 DBL (km) 3.291 3.37 3.638 3.61 WBL (km) 0.051 0.357 0.373 0.367 WBL/DBL (%) 1.5 10.6 10.3 10.2
Example 32
[0079] A paper-making trial was conducted on a pilot-scale paper machine. The machine used was a Fourdrinier (width 25 inches), with a nominal paper output of 160 lbs paper per hour. The pulps used were old corrugated containers (OCC) and a mix of OCC with recycled newsprint. Polymer was added in the range of 2-10 lbs/ton on a dry basis. Sample sheets were cut from the paper reel and conditioned in the same fashion as the hand-sheets in Example 27. Results were normalized for thickness and weight. The PVOH/VAm solution was prepared as in Example 26, filtered and stored in a drum. D-glucose was added to this stock solution, pH adjusted to 12 and the solution was then heated to 80° C., while monitoring viscosity. Measured viscosities were below 100 cps during use of the solution.
Example 33
[0080] Paper was made on the pilot machine using old corrugated containers (OCC) as the fiber source. The paper produced was 26-28 lbs per 1,000 square feet, with a caliper of approximately 9.0. A base sheet was produced with no additive. Then PVOH/VAm/D-glucose (P) was fed to the paper stock at a rate to give a 2 to 10 lb per ton (0.1-0.5%) application level on a dry basis. Results are summarized in Table 9. Properties reported were measured in the machine direction.
TABLE 9 P P P P Additive None (0.1%) (0.2%) (0.3%) (0.4%) P (0.5%) DBL km 6.407 6.469 6.005 6.402 5.903 5.917 WBL (km) 0.38 0.25 0.45 0.50 0.47 0.51 WBL/DBL (%) 5.9 3.9 7.5 7.8 8.0 8.5 Burst Index 2.683 2.878 2.804 2.787 2.711 2.597
Example 34
[0081] Paper was made as in Example 33, but using a mixture of OCC and old newsprint as fiber source. A base sheet was produced with no additive. Then PVOH/PVAm/D-glucose (P) was added at levels sufficient to give 6 and 8 lb/ton (0.3 and 0.4%) application levels. Properties reported were measured in the machine direction and are summarized in Table 10.
TABLE 10 Additive None P (0.3%) P (0.4%) DBL (km) 5.598 5.654 5.715 WBL (km) 0.19 0.35 0.52 WBL/DBL (%) 3.4 6.2 9.1 Burst Index 2.489 2.473 2.672
Example 35
[0082] The procedure of Example 34 was repeated, using PVOH/VAm/D-glucose (P) solution that had been aged for several hours to an increased viscosity. The polymer was added at levels sufficient to give 6 and 8 lb/ton (0.3 and 0.4%) application levels. Properties reported were measured in the machine direction and are summarized in Table 11.
TABLE 11 Additive None P (0.3%) P (0.4%) DBL (km) 5.598 5.524 5.909 WBL (km) 0.19 0.47 0.58 WBL/DBL (%) 3.4 8.5 9.8 Burst Index 2.489 2.676 2.837
[0083] The foregoing description and accompanying drawings set forth preferred embodiments of the invention at the present time. Various modifications, additions and alternative designs will, of course, become apparent to those skilled in the art in light of the foregoing teachings without departing from the scope of the invention. The scope of the invention is indicated by the following claims rather than by the foregoing description. All changes and variations that fall within the meaning and range of equivalency of the claims are to be embraced within their scope. | A composition includes water; at least one hydrophilic polymer containing at least two groups which are independently the same or different a primary amine group or a secondary amine group and at least one saccharide containing a reducible function as described above. The hydrophilic polymer and the saccharide are mixed to form a reaction mixture and reacted to increase the viscosity of the reaction mixture. The reaction is then substantially terminated by reducing the pH of the composition. A method of increasing the strength of a cellulosic pulp product includes the steps of: contacting wet cellulosic pulp with a composition comprising (i) at least one hydrophilic polymer containing at least two groups which are independently the same or different a primary amine group or a secondary amine group and at least one saccharide containing a reducible function, the hydrophilic polymer and the saccharide of the composition having been reacted in a crosslinking reaction prior to contacting the composition with the cellulosic pulp product to increase the viscosity the composition; and, after contacting the cellulosic pulp with the composition, causing the crosslinking reaction between the hydrophilic polymer and the saccharide of the composition to proceed further. | 3 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority under 35USC§119(e) of U.S. provisional patent application 61/389,825, filed on Oct. 5, 2010, the specification of which is hereby incorporated by reference.
TECHNICAL FIELD
This description relates to a furnace device to thermally treat finely divided particulate matter and a method for producing expanded minerals.
BACKGROUND
Expanded mineral particles are used in a wide range of applications such as insulation, refractories, admixtures for aggregates, soil mixes and the like, where a desired goal of the producer is to transform minerals, such as perlite and vermiculite, from their original mined state into lightweight expanded matter having certain predetermined physical characteristics at a reasonable cost.
The majority of furnaces employed to expand minerals in operation today are energy inefficient. A typical furnace consists of an oil or gas burner and a venturi to accelerate the air/fuel mixture into a tuyere mounted below a vertical tube through which crude mineral ore to be expanded is fed into the open flame. Cold atmospheric air is drawn into the venturi and up into the furnace through a negative draught condition from the exhaust fan. A forced draught fan provides combustion air to the burner. The fuel cloud enters the furnace at the venturi which is positioned directly above the burner head. The combustion air and fuel, ejected at high velocity from the burner head travel through an open gap before reaching the venturi. This condition naturally draws in surrounding cold air into the furnace. For the purposes of this description, this type of combustion setup is referred to as having an atmospheric coupling; i.e. the burner is not fully enclosed. The flame can be directly seen through the open space below the venturi and also through an open port typically fitted onto the side of the tuyere to release to atmosphere under expanded ore and impurities from the continuous process. The fuel air mixture lights and burns through the venturi and tuyere as the flame advances upwards into the vertical expansion chamber. The flame and hot gases heat a steady stream of mineral particles fed into the furnace. In the case of perlite the ore granules glow red as they are heated through the plastic stage. Water of crystallization and other gases that are present in the hot glassy perlite are released as vapour, causing an immediate and significant expansion. Once expanded, the particles, being sufficiently lighter in weight, are carried to the top of the furnace by the process air. Not all the ore fed to the furnace fully expands. Impurities may be present in small amounts which never expand; i.e. obsidian in the case of perlite. These particles must be continuously withdrawn from the combustion zone failing which combustion becomes erratic and the operation shuts down. For this reason alone, systems using atmospheric combustion are preferred. This method always leaves a space where unexpanded mineral can simply fall out of the furnace through a gap and thereby results in a continuous operation. In furnaces designed with atmospheric combustion the pressure above the venturi is near zero so that an opening on the tuyere's slope can be advantageously made to let out undesirable higher density ore, impurities and partly fused agglomerates. This opening also serves to see the flame particle turbulence where it is greatest. The expanded mineral is subsequently separated from the hot process air in cyclones or other separators, cooled, graded and packaged. The exhaust air is diluted with cooling air and filtered in a bag house filter. An induced draught fan pulls the air through the furnace and bag filter and discharges to atmosphere.
In recent years, many attempts have been made to achieve higher efficiency expanded mineral production. The approach often used is to pressurize the furnace by having the burner fully enclosed and having a furnace construction that preheats the combustion air by having it pass outside of the expansion chamber as fully described in U.S. Pat. No. 2,639,132, May 19, 1953 J. H. Bradford. However these systems are much more expensive to build and maintain. The positive operating pressure within the expansion chamber presents a challenge and risk as thermal cracks commonly appear in this chamber which are typically replaced annually. Once cracks form, hot gases under pressure escape. Additionally a separate solution to unexpanded ore dropouts must be provided and direct visual access to the flame is lost as there can be no open port on the side of the tuyere as is the case in the furnace with the typical atmospheric coupling.
There are many installations of furnaces that are employed to expand minerals such as perlite and vermiculite, oxides of metals or otherwise thermally treat mineral particles on a continuous basis.
As an example, U.S. Pat. No. 6,244,860 relates to an apparatus for producing perlite granules, which is having an expansion tube and one or more burners arranged at one end of the expansion tube. The combustion air is blown into the flame through one or more combustion air nozzles. An additional subsonic nozzle is arranged in at least one combustion air nozzle. In this process for expanding raw perlite in the updraft from a flame, with the introduction of oxygen or oxygen-enriched air into this flame, the oxygen or oxygen-enriched air is introduced axially into the flame through subsonic nozzles.
Additionally, in U.S. Pat. No. 2,639,132 (James H. Bradford), there is provided a processing furnace for discrete solids having a fully enclosed and therefore pressurized burner. The processing furnace provides for a closed waste compartment at the base of the furnace fitted with a door for waste removal at convenient intervals. Such a door, if opened during operation, would issue hot process gases under pressure which is dangerous and not recommended. Therefore the furnace needs to be shut down periodically for clean out thereby loosing the efficiency benefits of a continuous operation.
Moreover, U.S. Pat. No. 4,347,155 (Kenneth L. Jenkins) shows preheated combustion air supplied to a fully enclosed burner and is subject to the positive pressure as developed by the combustion air fan and additionally shows a secondary air pipe for admitting preheated air above the venturi into a second enclosure which surrounds at least a portion of the wall of the expansion chamber. It is to be noted that this device is fully enclosed, operates under pressure and does not provide this secondary pre-heated air which is admitted below the venturi around the burner head nor does it provide for a tertiary stage pre-heated combustion air stream around the venturi.
Current practice is for the combustion to take place at the base of the expansion chamber which is open to atmosphere. In the case of perlite, the expansion operation typically requires four to five times (400-500%) more energy than the theoretical heat calculations suggest. Most of this heat is contained within the exhaust air which is rejected to atmosphere and seldom used.
Because the furnace is open to atmosphere at its base, cold air is naturally drawn into the furnace which dilutes the hot flame and this adversely affects overall efficiency. This cold air drawn in at the base is referred to as ‘dilution’ or ‘secondary air’. Some additional air above the stoichiometric ratio is useful to ensure complete combustion and to assist in lifting the expanded perlite out of the furnace however it has been observed that 40-60 percent excess air is typically drawn in at this point which adversely affects the efficiency of the expansion operation.
For these disadvantages established, there is therefore a need for an improved furnace device to offset the quenching effect of the cold air normally drawn in at that point and to increase conversion and yield in any process of thermal expansion of mineral particles.
SUMMARY
It is an object of the present disclosure to provide an improved furnace device to offset the quenching effect of the ambient air normally drawn into the furnace around the flame and which features a burner with the very useful atmospheric coupling below the venturi and to provide a higher efficiency process for thermal expansion of mineral particles.
It is another object to provide a furnace device to be installed in a furnace system to offset the quenching effect of ambient air drawn in the furnace system which comprises: a burner head positioned at a distance for an atmospheric coupling of the furnace system; and a ring portion from which an air curtain extends peripherally from the burner head thereby forming a controlled secondary combustion stage and an atmospheric coupling of the burner head with a tuyere of the furnace system.
According to another embodiment, there is provided the furnace device as described above, wherein the burner head is for fuel.
According to another embodiment, there is provided the furnace device as described above, wherein the fuel is oil.
According to another embodiment, there is provided the furnace device as described above, wherein the burner head is for gas.
According to another embodiment, there is provided the furnace device as described above, wherein the air curtain comprises preheated air.
According to another embodiment, there is provided the furnace device as described above, wherein the air curtain comprises preheated combustion air.
According to another embodiment, there is provided the furnace device as described above, wherein the ring portion is of a circular configuration.
According to another embodiment, there is provided the furnace device as described above, wherein the ring portion is made of a metallic material suitable for the temperature encountered.
It is yet another object to provide a tuyere for thermal expansion of mineral particles installed on an expansion chamber of a furnace system which comprises: an air inlet which is installed inside the tuyere to provide an heated air intake causing a tertiary combustion stage surrounding a burning flame with higher oxygen air.
According to another embodiment, there is provided the tuyere as described above, wherein the air inlet is positioned at a point where combustion takes place above a venturi in an atmospheric coupling.
According to another embodiment, there is provided the tuyere as described above, wherein the air inlet is positioned at a point where combustion takes place partly below a venturi in an atmospheric coupling.
According to another embodiment, there is provided the tuyere as described above, wherein the air inlet is positioned at a point where the flame front is already established to provide a tertiary combustion stage surrounding a burning flame.
According to another embodiment, there is provided the tuyere as described above, wherein the air inlet is positioned at a point for a gas flame pre-ignition.
It is yet another object to provide tuyere kit for a furnace for thermal expansion of mineral particles to be installed on an expansion chamber of a furnace system which comprises: an air inlet to be installed inside the tuyere to provide a preheated air intake causing a tertiary combustion stage surrounding a burning flame with higher oxygen air.
According to another embodiment, there is provided the tuyere kit as described above, wherein the air inlet is to be positioned at a point where combustion takes place above a venturi in an atmospheric coupling.
According to another embodiment, there is provided the tuyere kit as described above, wherein the air inlet is to be positioned at a point where combustion takes place below a venturi in an atmospheric coupling.
According to another embodiment, there is provided the tuyere kit as described above, wherein the air inlet is to be positioned at a point where the flame front is already established to provide a tertiary combustion stage surrounding a burning flame.
According to another embodiment, there is provided the tuyere kit as described above, wherein the air inlet is to be positioned at a point where the flame front is already established to provide a tertiary combustion stage surrounding a burning flame.
According to another embodiment, there is provided the tuyere kit as described above, wherein the air inlet is to be positioned at a point for a gas flame pre-ignition.
It is yet another object to provide a multistage combustion furnace system kit for a furnace and a tuyere for thermal expansion of mineral particles which comprises:
a furnace having an expansion chamber for receiving the mineral particles; a burner head to be connected at a distance for an atmospheric coupling of a furnace and for operating the multistages combustion furnace system, wherein the furnace has an expansion chamber; a furnace device to be connected at a distance for an atmospheric coupling of the burner head to offset the quenching effect of ambient air normally drawn in a furnace, wherein said furnace device is to be installed between said burner head and a tuyere; and a tuyere for thermal expansion of mineral particles to be connected between the expansion chamber and the furnace device; wherein an inlet of preheated air is to be connected to at least one of a tuyere, the burner head or a furnace device.
According to another embodiment, there is provided the multistage combustion furnace system kit as described above, wherein the burner head is for gas.
According to another embodiment, there is provided the multistage combustion furnace system kit as described above, wherein the fuel is oil.
According to another embodiment, there is provided the multistage combustion furnace system kit as described above, wherein an inlet of preheated air is to be connected to at least two of the tuyere, the burner head or the furnace device.
According to another embodiment, there is provided the multistage combustion furnace system kit as described above, wherein an inlet of preheated air is to be connected to the tuyere, the burner head and the furnace device.
According to another embodiment, there is provided the multistage combustion furnace system kit as described above, wherein the tuyere is to be connected to an air inlet.
According to another embodiment, there is provided the multistage combustion furnace system kit as described above, wherein the burner head is to be connected to an air inlet.
According to another embodiment, there is provided the multistage combustion furnace system kit as described above, wherein the burner head is to be connected to an adjustable air inlet to adjust the amount of air intake.
It is another object to provide a multistage combustion furnace system for thermal expansion of mineral particles which comprises:
a furnace having an expansion chamber for receiving the mineral particles; a burner head connected at a distance for an atmospheric coupling of the furnace and for operating the multistage combustion furnace system; a furnace device connected at a distance for an atmospheric coupling of the burner head to offset the quenching effect of ambient air normally drawn in the furnace; and a tuyere for thermal expansion of mineral particles connected between the expansion chamber and the furnace device; wherein an inlet of preheated air is connected to at least one of the tuyere, the burner head or the furnace device.
According to another embodiment, there is provided the multistage combustion furnace system as described above, wherein the burner head is for gas.
According to another embodiment, there is provided the multistage combustion furnace system as described above, wherein the fuel is oil.
According to another embodiment, there is provided the multistages combustion furnace system as described above, wherein an inlet of preheated air is connected to at least two of the tuyere, the burner head or the furnace device.
According to another embodiment, there is provided the multistage combustion furnace system as described above, wherein an inlet of preheated air is connected to the tuyere, the burner head and the furnace device.
According to another embodiment, there is provided the multistage combustion furnace system as described above, wherein the tuyere is connected to an air inlet.
According to another embodiment, there is provided the multistage combustion furnace system as described above, wherein the burner head is connected to an air inlet.
According to another embodiment, there is provided the multistage combustion furnace system as described above, wherein the burner head is connected to an adjustable air inlet to adjust the amount of air intake.
The following terms and expressions are defined below.
The expression “expanded mineral particles” is intended to mean any mineral that expands upon heating. Examples include without limitation, perlite, vermiculite, diatomite, pumice and specific types of clay and shale, and the like. More particularly, perlite is a generic term for a naturally occurring mineral glass.
The term “hot tuyere” refers to a device of this invention having a vertically diverging inner cone that surrounds the major portion of the flame, an outer cylindrical body that receives preheated combustion air, a venturi throat section to accelerate the air fuel mixture into the furnace and a venturi crown to promote intermingling of the air and air fuel mixture.
The term “hot air ring” refers to a device of this invention that produces a hot air curtain that stops the natural draft of cold air ingress surrounding the burner head.
The expression “atmospheric coupling” is intended to mean a free space between the burner head and the tuyere wherein the air-fuel mixture crosses up through the venturi whilst heavy particulate matter that did not expand falls out of the tuyere through this same space.
The expression “ambient air” is intended to mean air at ambient temperature. In normal configurations of furnace systems, the ambient air entering the furnace would require the furnace system to provide more energy.
BRIEF DESCRIPTION OF THE DRAWINGS
Further features and advantages of the present disclosure will become apparent from the following detailed description, taken in combination with the appended drawings, in which:
FIG. 1 illustrates the flow sheet which describes a process for thermal expansion of mineral particles including a multistage combustion furnace system in accordance with an embodiment;
FIG. 2 illustrates the three stages of combustion air admission to the multistage combustion furnace system for thermal expansion of mineral particles in accordance with another embodiment;
FIG. 3 illustrates a hot air ring device which offsets the quenching effect of the cold air for thermal expansion of mineral particles in accordance with another embodiment;
FIG. 4A and FIG. 4B illustrate a venturi crown device within the hot tuyere of the multistage combustion furnace system for thermal expansion of mineral particles in accordance with other embodiments;
FIG. 5 illustrates a typical furnace before adopting the multistage combustion furnace system for thermal expansion of mineral particles in accordance with another embodiment;
FIG. 6 illustrates another view of a multistage combustion furnace system at operating temperature showing the hot tuyere with reject port in accordance with another embodiment;
FIG. 7 illustrates a hot air ring device of the multistage combustion furnace system showing the open atmospheric gap between the hot air ring and the hot tuyere while burning fuel oil through a nozzle in accordance with another embodiment;
FIG. 8 illustrates the three air inlets of the multistage combustion furnace system with controls and instrumentations for the multistage combustion furnace system for thermal expansion of mineral particles in accordance with another embodiment;
FIG. 9 illustrates a heat exchanger part of the process for the thermal expansion of mineral particles in accordance with another embodiment;
FIG. 10 illustrates the flow sheet which describes a process for the thermal expansion of mineral particles including a multistage combustion furnace system in accordance with another embodiment;
FIG. 11 illustrates a cross-section view of the three stages of combustion air admission to the multistage combustion furnace system for thermal expansion of mineral particles in accordance with another embodiment;
FIG. 12A illustrates a top view of a hot air ring device which offsets the quenching effect of the cold air for thermal expansion of mineral particles in accordance with another embodiment;
FIG. 12B illustrates an elevation view of the hot air ring device of FIG. 12A which offsets the quenching effect of the cold air for thermal expansion of mineral particles in accordance with another embodiment;
FIG. 13 illustrates a cross-section view of the tuyere designed for a fuel fired furnace system in accordance with another embodiment;
FIG. 14A is a top view of a venturi in accordance with another embodiment;
FIG. 14B is a cross-section view of the venturi of FIG. 14A ;
FIG. 15A is a top view of a venturi in accordance with another embodiment;
FIG. 15B is a cross-section view of the venturi of FIG. 15A ;
FIG. 16A is a top view of a venturi in accordance with another embodiment;
FIG. 16B is a cross-section view of the venturi of FIG. 16A ;
FIG. 17 illustrates a cross-section view of the tuyere designed for gas in accordance with another embodiment;
It will be noted that throughout the appended drawings, like features are identified by like reference numerals.
DETAILED DESCRIPTION
The present description relates to a multistage combustion furnace system and a process for the thermal expansion of mineral particles. The present description relates to a multistage combustion furnace system furnace for decreasing the energy consumption of the process for the thermal expansion of mineral particles.
Now referring to the drawings, and more particularly to FIGS. 1 and 10 , there is shown a process 10 for the thermal expansion of mineral particles including a multistage combustion furnace system 12 . In the process 10 , the combustion air fan 40 supplies cold air to the heat exchanger 56 where valuable heat is gained from the exhaust gases. The pre-heated air 13 is supplied to the multistage combustion furnace system 12 , which is open to atmosphere at its base, at three distinct air inlet conduits 42 , 44 and 46 . The pre-heated air 13 splits to enter the burner head 47 (from the air inlet 42 ), the hot air ring device or furnace device 45 (air inlet 44 ) and the hot tuyere 49 (air inlet 46 ). Combustion air to the burner head 47 (air inlet 42 ) is greatly reduced so that there is insufficient air for complete combustion. A secondary air flow into the hot air ring device or furnace device 45 which produces an annular air curtain of pre-heated air to prevent the ingress of cold air that naturally occurs at that point.
The hot tuyere 49 delivers the remaining air in a powerful ring jet portion 58 fully surrounding the emerging flame front rising up against the falling particles in counter current mode. As combustion progresses, the hot gases produced interact with a steady stream of mineral particles fed directly into the expansion chamber 18 above and into the flame for heat treating or expansion as the case may be. The expanded minerals rise up the multistage combustion system furnace 12 with the process air from air inlets 42 , 44 and 46 while unexpanded and heavier matter simply falls out the bottom of the expansion chamber 18 of the multistage combustion furnace system 12 through the venturi 43 (extend line to reach the center of the venturi) or is ejected from the open port 15 and falls to the ground for later pickup and disposal. The furnace system 12 exhaust gases have sufficient velocity to carry the now lightweight material out the top of the multistage combustion furnace system 12 . The hot exhaust gas then enters a double wall rotating drum having raw ore flowing through the inner cylinder and hot exhaust with expanded particulate matter flowing through the space formed by the fixed shell and rotating drum for ore preheating prior to entering the multistage combustion furnace system 12 . Expanded material is separated from the exhaust air by a cyclone, settling chamber or other suitable collector, where after the particles are cooled and packaged or stored.
Exhaust air leaves the furnace top at about 1 832° F. or about 1000° C., in the case of perlite. Due mainly to air leaks in the rotary heater, through slip flanges and radiation losses, the air temperature drops to about 1000 to about 1,200° F. (about 538-about 650° C.). The heat exchanger 56 is positioned after both the ore preheater and product separator so as to protect the heat transfer elements from undue abrasive wear. The hot air expelled from the multistage combustion furnace system 12 is further diluted with cold air bleed-in ducts in order to protect the bag filter and fan from high temperature. The multistage combustion furnace system 12 operates under negative pressure so that all openings draw cold air in.
The typical perlite furnace uses more combustion air than is necessary for expansion. The high value of excess air is the result of the natural suction produced by the high velocity flow of the air fuel mixture through the venturi 43 without a hot air ring or furnace device. Far greater thermal efficiency can be obtained by reducing the air flow that enters the system 10 to just above the stochiometric or theoretical levels required to burn the fuel instead of the 40-60% excess air as typical of conventional furnaces. Because the process 10 , having a hot air ring or furnace device 45 and hot tuyere 49 , needs very little excess air, fuel consumption and exhaust air heat losses are significantly reduced. As a result of using near stoichiometric air to fuel ratios, the flame burns hotter, more evenly and intensively and it glows brighter. At this point, mineral particles expand in a more lively fashion resulting in higher volume output for the same feed input of particles. Moreover, the production rate goes up, while the specific fuel consumption goes down which translates into higher production using less fuel. This positively affects all plant inputs: mineral ore mass, fuel consumption and labor.
Still referring to FIGS. 1 and 10 , in the process 10 for the thermal expansion of mineral particles, the multistage combustion furnace device 12 is designed to continuously and rapidly heat crushed and sized ore at high temperature where the discrete ore particles expand. The multistage combustion furnace system 12 , which is open to atmosphere to allow atmospheric combustion, comprises an ore feed device 14 . The ore feed device 14 may be, without limitations, a bucket elevator, a screw conveyor, a belt conveyor and the like. Furthermore, the multistage combustion furnace system 12 comprises an ore pre-heater 16 . The ore pre-heater 16 may be, without limitations, a rotary drum type, a heat exchanger and the like. The ore pre-heater 16 is used to increase the temperature of the unexpanded mineral particles before entering the furnace through the ore feed tubes or chutes 14 that direct the mineral particles through the sides of a tall vertical furnace chamber 18 . Indeed, the process 10 for the thermal expansion of mineral particles also comprises a substantially vertical expansion chamber 18 which is typically, without limitations, cylindrical, an air inlet 42 for entering the burner head 47 positioned at the base of the vertical expansion chamber 18 and firing vertically up into the vertical expansion chamber 18 , a fuel train 22 with valves to control the flow of fuel, a combustion air fan 40 to provide air for complete combustion of the fuel and an outlet duct 26 atop the furnace to carry away the hot expanded mineral particles to the product collection system. It is to be noted that the fuel burner head 47 may also be a gas burner head 47 for operating a gas fired multistage combustion furnace system. Moreover, the process 10 for the thermal expansion of mineral particles comprises product collection system to separate the expanded mineral particles from the hot air stream, usually consisting, without limitations, of one or more of the following: a hot separator, a hot box, a hot cyclone, a bag filter or the like. The process 10 also comprises an exhaust fan to draw the air expelled from the multistage combustion furnace system 12 through the process 10 and an expanded minerals cooling system. Finally, the system 10 may further comprise interconnecting ductwork to complete the system, rotary airlock valve(s) as may be required and controls and instrumentation.
Preheated air 13 that is required for combustion of fuel or gas and lift for the expanded mineral particles is supplied by the combustion air fan 40 . Ducts direct this air to the heat exchanger 56 which transfers heat from the hot exhaust air 17 to the combustion air 19 .
Now referring to FIG. 2 , there is shown the multistage combustion furnace system 12 and the pre-heated air 13 that flows into three (3) different inlets 42 , 44 and 46 . The preheated air 13 splits to the burner head 47 , the hot air ring device or furnace device 45 and to a high velocity ring jet portion 58 surrounding the venturi 43 above the throat within the body of the hot tuyere 49 . By separating the air flow into three air inlets 42 , 44 and 46 the effect is thus: approximately half (50%) of the air required to burn all of the fuel or gas is supplied to the burner head 47 . A small amount, approximately, 5-15% of secondary air is directed to the hot air ring or furnace device 45 around the atmospheric coupling formed between the burner head 47 and the hot tuyere 49 . The balance is supplied in the air inlet 46 where the air is made to shear through the advancing air fuel flame front rising up into the vertical expansion chamber 18 after it flows up through the venturi 43 . In order to produce a steady ring jet of preheated air that shears through the flame cloud with strong force, three internal sections in the hot tuyere 49 have been developed: first there is the upper zone where the preheated air 13 enters the hot tuyere 49 . It is bound on the periphery by the outer cylindrical body and on the inside by the cone shape of the hot tuyere 49 . A flow separator, described as a flat ring with a minimum of four air holes and having a narrow gap between the outer wall and the inner cone define the lower portion of the entry zone whose sole function is to equalize the flow (air inlet 42 ) entering the hot tuyere 49 so as to be uniform throughout. The second section of the hot tuyere 49 has the largest internal volume of the three zones. It is defined by the flow separator above, the outer cylindrical walls and inner cone of the tuyere 49 and serves as an air capacitor. This feeds the third section called the nozzle zone 23 . The internal passages in the nozzle zone 23 are designed to progressively accelerate the preheated air 13 to a velocity comparable to that of the burner head 47 (air inlet 42 ), typically 6-12,000 fpm (30-60 m/s). The free energy in the preheated air 13 displaces the fuel or gas that would normally be used to raise it up to the pre-heat temperature.
Now referring to FIG. 3 , there is shown a furnace device 45 (or hot air ring device), in accordance with another embodiment, for thermal expansion of mineral particles, which offsets the quenching effect of the cold air naturally drawn into a conventional furnace, with preheated air 13 freely obtained via the heat exchanger 56 . The furnace device 12 is to be installed on a multistage combustion furnace system 12 to offset the quenching effect of the cold air drawn in the multistage combustion furnace system 12 . The furnace device 45 , more particularly is a hot air ring device. It is to be noted that the gas of the hot air ring device may be air, or any other gas that can fit with the furnace device 45 . The furnace device 45 comprises a fuel head ( FIGS. 1 and 2 ) arranged at one end of the multistage combustion furnace system 12 ; and a ring jet portion 58 from which preheated air annular curtain extends peripherally from the burner head 42 thereby forming a controlled secondary combustion stage.
In the furnace device 45 as described above, the air drawn may be preheated combustion air 13 . It is also to be noted that the ring jet portion 48 may be circular. Moreover, the ring jet portion 48 of the multistage combustion furnace system 12 may be made of a metallic material suitable for the temperature encountered. Additionally, the multistage combustion furnace system 12 operates with a neutral pressure point above the flame.
Now referring to FIG. 4A and FIG. 4 there is shown a venturi crown 50 which sits on the top side of the venturi insert 43 in accordance with another embodiment. The venturi crown 50 has a minimum of four radial elements 52 with upwardly diverging inclined tips that extend from the central fuel air cloud zone emerging from the venturi 43 into the annular ring jet portion air stream surrounding the venturi 43 . The key feature here is the protruding inclined elements or radial elements 52 of the venturi crown 50 which serves as a pathway for the rich air fuel mixture to stream out from the central portion 54 and be subjected to the full force of the high velocity oxygen rich preheated annular air curtain.
In the case of oil fired multistage combustion furnace systems, an additional flat disc may be fitted to the crossbars of the venturi crown 50 . In another embodiment, the inclined elements or radial elements 52 have a V-shaped cross section with the apex on the upper side so that the radial elements 52 form an inclined channel to radially distribute the preheated air 13 across the shearing force of the annular air curtain. The venturi crown 50 adds turbulence to the combustion process and positively contributes to the intimate mixing of the centrally rich air fuel cloud with the remainder of the combustion air as supplied by the annular air curtain.
Now referring to FIG. 5 , (photograph) there is shown a conventional furnace. The upwardly curved pipe supplies cold combustion air to the burner head which directs the fuel air mixture vertically upwards across an open atmospheric gap. Notice the hot perlite particles being ejected from the furnace. This normally occurs in pulses notice the color changes in the tuyere: red hot on top and cold black metal on the bottom. The temperature variation exceeds about 1000° F. (about 555° C.). This leads to thermal stress deformation and eventual crack formation to relieve this stress. It is common to replace the tuyere every 6 months and the furnace liner or expansion chamber annually, notwithstanding the use of special heat resistant stainless steels for these critical items. This is a direct result of the excessive amount of cold quenching air entering the conventional furnace through the venturi 46 and reject port fitted to the side of the tuyere 47 .
Now referring to FIG. 6 there is shown another view of the furnace system 12 for the thermal expansion of mineral particles at the flame temperature showing the reject port on the hot tuyere 47 . Notice that the unexpanded or partly expanded ore granules sit in the lower part of the reject port which serves to partially fill the opening. This condition demonstrates the absence of pressure and airflow pulsing so characteristic of conventional furnaces where it is usual for hot gases and hot glowing heavier perlite particles spew out in a positive pulse and cold air enters on the negative side of the pressure pulse.
Now referring to FIG. 7 there is shown the furnace device 45 (or hot air ring device) sitting on the burner head 47 with an oil nozzle 23 . Notice that the well defined steady flame begins at the nozzle 23 tip which is concentrically mounted below the venturi 43 within the body of the hot tuyere 49 .
Now referring to FIG. 8 there is shown the inlets 42 , 44 and 46 of the multistage combustion furnace system, dampers and instrumentation to adjust the split of air between the burner head, the hot air ring device and the hot tuyere. Ore feed rate, burner management and other combustion air settings remain in the control of the operator as they are today. Automatic furnace draft control (not shown) to modulate the draw of air through the furnace with a motorized damper is extremely useful to ensure stable and smooth furnace operation. This is achieved by having a pressure sensor fitted to the top of the furnace reporting to a pressure controller that operates an exhaust air damper modulating the exhaust air flow. The precise control of the static air pressure at the top of the furnace system produces control over the quantity of secondary air admitted to the base of the tuyere in the gap above the burner head and limits the cold air ingress at every opening, especially the open reject port on the side of the tuyere. This absolutely minimizes cold air ingress to a consistent level which is adjusted to be slightly over the stoichiometric requirement and yields a highly responsive efficient operation.
Now referring to FIG. 9 there is shown a heat exchanger 56 of the process 10 for the thermal expansion of mineral particles. It is to be noted that a heat exchanger 56 to pre-heat combustion air 19 for entering the furnace system 12 designed for heat treating or expanding finely divided particles is well-known in the prior art.
The process 10 and the furnace system 12 can be used with both liquid and gaseous fuels however, there are significant differences in the venturi 43 and annulus area 58 and in the velocity through the hot air ring device, or furnace device 45 . The rest of the process 10 and of the furnace system remains the same system as described above.
In the case of the oil-fired multistage combustion furnace system 12 as shown in FIGS. 1 and 10 , metered fuel is atomized in a single or two fluid nozzle 23 centered below the venturi 43 . First it is necessary to use a flow restrictor in the form of a disc (venturi crown 50 ) fitted across the venturi 43 . The venturi crown 50 presents a flat impinging surface where some of the fuel, oil for example, impact the disc, coalesce, and flow to the edges where the accelerating fuel cloud atomizes that portion of the fuel leaving the disc. Various designs of the venturi crowns 50 are shown in FIGS. 4A, 4B, 14A, 14B, 15A, 15B, 16A and 16B . Moreover, with an oil-fired multistage combustion furnace system 12 , combustion takes place above the venturi 43 with little to no flame below it in the atmospheric coupling zone. In the oil-fired furnace system 12 , it is advantageous to split the three pre-heated combustion air inlets 42 , 44 and 46 as follows: 5-15% air to the hot air ring, or furnace device 45 (air inlet 44 ) to fill the atmospheric coupling and the balance split with similar amounts of air through the bottom burner head 47 (inlet 42 ) and top tuyere 49 (inlet 46 ) above the venturi 43 .
The pre-heated air 13 initiates fuel oil evaporation providing a higher energy state before the combustion chamber above the venturi 43 . This method of fuel/air preparation provides excellent conditions for complete combustion. The three stages combustion air inlets (inlet 42 , 44 and 46 ) allows the operator to control the air to fuel ratio at three points; in the traditional burner head 47 , at the atmospheric coupling via the hot air ring (or furnace device 45 ) and above the venturi 43 in the furnace system 12 . It has been found that perlite expansion increases by 10 to 20% when the central air rising up across the atmospheric coupling into the venturi 43 is near half of the air required for complete combustion. This results in an extremely fuel rich and hot fuel cloud entering the furnace system 12 through the venturi 43 (inlet 46 ). Final combustion air enters the final firing zone in a high speed annulus surrounding the fuel cloud as it emerges vertically up from the venturi 43 .
On the other hand, with a gas-fired furnace system 12 , there is no need for any flow restrictor (venturi crown 50 ) across the venturi since the fuel is perfectly miscible in the air by its nature. Also, with gaseous fuel, combustion begins below the venturi 43 (below inlet 46 ) and traditionally this presents operational problems defined as flame spill. With any significant gas burning in the region of the atmospheric coupling, a pressure wave results from the expanding gas that acts in all directions. Flame spilling pushes gas away from the center where it is falling away from the pressure pull of the venturi 43 (inlet 46 ) and is fuel lost to the process 10 .
This problem is alleviated by greatly reducing the amount of air delivered below the venturi 43 (below inlet 46 ). It is advantageous to split the three pre-heated combustion air inlets 42 , 44 and 46 as follows: about 5-15% of the preheated air 13 to the hot air ring device (or furnace device 45 ) to fill the atmospheric coupling (inlet 44 ), about 20-30% through the burner head 47 (inlet 42 ) and the balance, being the major portion, up through the annulus area 58 of the venturi 43 (inlet 46 ). This results in a larger annulus 58 (inlet 46 ) than required for oil fired furnace systems 12 . Additionally, it is advantageous to provide air jets in rings supplying oxygen rich air at the base of the flame inside the tuyere 49 . For example, FIGS. 14A, 14B, 15A, 15B, 16A and 16C depicts two rows of ring jet portions 48 ; the first row ejecting air perpendicular to the fuel cloud at the venturi 43 /tuyere 49 interface while the second row of ring jet portions are positioned on the conical walls of the tuyere 49 just above the venturi 43 . The sum of the area of the one, two or more rows of ring jet portions is small in relation to the annulus area, being about one fifth of the area of the annulus area 58 .
Moreover, flame spills are further abated in gaseous systems by increasing the exit velocity of the air leaving the hot air ring device (or furnace device 45 ) compared to the case when burning fuel oil.
The process 10 and the furnace system 12 provides the ability to keep the air fuel mixture seriously oxygen deficient below the venturi 43 thereby reducing flame spill as an inefficiency factor and reserving the needed oxygen for addition to the burning air/fuel mixture above the venturi inside the tuyere 49 .
It is to be noted that the pre-heated air 13 is returned to the base of the furnace system 12 where it is split into three adjustable streams in the air inlets. The major portion is supplied to the burner head 47 ; secondly a hot air curtain peripherally extends the burner head 47 to replace the ingress of cold air between the burner head 47 and venturi 43 with now preheated air 13 freely obtained via the heat exchanger 56 ; the third air input enters the hot tuyere 49 above the established flame to provide a tertiary combustion stage surrounding the richly burning flame with higher oxygen lean air enveloping the advancing fuel cloud. Together with the automatic pressure control acting on the exhaust air drawn through the furnace system 12 the combustion thus achieved, having three stages of air admission advantageously arranged beginning at the center of the burner head 47 , and peripherally above the burner head 47 and finally above the venturi 43 throat surrounding the rapidly evolving rising flame front is more uniform and complete, burning more powerfully than ever before and this produces a greater expansion effect in the mineral particles. In the case of perlite the expanded material produced is lighter as evidenced by a reduction in bulk density. Production rates go up in consequence. The invention saves fuel, ore and production time.
The furnace exhaust air 17 leaving the heat exchanger will be at a lower air temperature than before, so that the air temperature in the bag house filter will be reduced by a significant degree leading to longer bag life and lower maintenance costs.
Then, it is well known that inputs to any expanded mineral expansion process in order of costs are mineral ore, fuel (typically natural gas, propane or oil) and labour. At the opposite, the major output will be expanded mineral particles measured by volume.
The present invention will be more readily understood by referring to the following examples which are given to illustrate the invention rather than to limit its scope.
Example 1
Perlite Production
The process 10 of FIG. 1 was used to create a first prototype of the furnace device 45 . Moreover, the furnace system 12 , also shown in FIGS. 1 and 10 features a burner head 47 having an atmospheric coupling or open space between the burner head 47 and the venturi 43 has been used to illustrate the characterization of the production of perlite particles. The furnace system comprises a vertical expansion chamber 18 , typically cylindrical, of about 18″ diameter by about 10-12′ tall, a hot tuyere 49 with entry, holding and high velocity annular nozzle zones 23 and a venturi crown 50 that extends from a point above the burner head 47 so as to leave a gap up to the vertical walls of the expansion chamber 18 , a fuel or gas burner head 47 and a hot air ring device or furnace device 45 that can be installed on any vertical furnace system 12 where mineral particles fall down through a tube and meet a rising current of fuel (or gas)/air mixture and combustion gases (preheated air 13 for example). Instead of allowing cold air to freely enter the process, the hot air ring device 45 takes a portion of the pre-heated air 13 from the heat exchanger 56 and forms a hot air ring (or annular air curtain) at the base of the furnace system 12 to offset the quenching effect of the cold air normally drawn in at that point. Surprisingly, only a small amount of pre heated air 13 is required to accomplish this. It has been shown by this first prototype that perlite ore savings present a density of about 10% lower (6.65 lb/ft3 to 6.0 lb/ft3). This prototype also shows that the energy recovery system for thermal expansion of mineral particles provides about 15% to 20% in energy savings. Finally, the feed rate has been augmented from about 1 400 lb/hour to 1 800 lb/hour so then production went from about 222 cubic feet per hour to 275 cubic feet per hour.
While preferred embodiments have been described above and illustrated in the accompanying drawings, it will be evident to those skilled in the art that modifications may be made without departing from this disclosure. Such modifications are considered as possible variants comprised in the scope of the disclosure. | The present document describes a multistages combustion furnace system for thermal expansion of mineral particles which comprises: a furnace having an expansion chamber for receiving the mineral particles; a burner head to be connected at a distance for an atmospheric coupling of the furnace and for operating the multistages combustion furnace system; a furnace device to be connected at a distance for an atmospheric coupling of the burner head to offset the quenching effect of ambient air normally drawn in the furnace; and a tuyere for thermal expansion of mineral particles to be connected between the expansion chamber and the furnace device; wherein the multistage combustion furnace system is to be connected with an inlet of preheated air. | 5 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates an oxygen maintenance and regulation concentrator, especially a portable oxygen maintenance and regulation concentrator apparatus operated under the normal temperature and pressure using the electrochemistry reaction.
[0003] 2. Description of the Prior Art
[0004] The oxygen on the earth is one sort of the widespread application gas, especially for the personnel medical service demand, as inside the hospital or in the battlefield situation, even in the rare oxygen area around the high mountain for the personnel oxygen supplies, all are possible latent demands.
[0005] In the conventional oxygen supply system, the large-scale gas liquefaction way and the gas adsorption procedure are usually applied for providing the pure oxygen and for the large-scale industry demands.
[0006] Furthermore, in the industry technology field, there are many of several oxygen production methods, such as the thin film separation method, the water electrolysis method and so on. However, in the design for the oxygen production method, due to the security and convenience consideration, actually is unable to be developed as the portable oxygen apparatus. The conventional breathing apparatus is unable to be applied to the portable-type equipment, i.e. the portable-type equipment means for the easy carriageable equipment or the simple movement equipment. However, due to the huge occupation for the conventional technology, space so that the conventional technologies are completely not applied to the portable breathing apparatus.
[0007] Therefore, concerning the medical and the special environment demands, portable operated under the normal temperature and atmosphere oxygen mask have become as the important and the quite development potential equipments. Regarding to the prior art, U.S. Pat. No. 6,638,400 “Electrochemical oxygen concentrator” invention patent, although using the electrochemistry reaction, the electrode plate are not the porous type metal plate, also the operating temperature reaches as high as 500° C., being unable to operate under the normal temperature. Moreover, regarding to the prior art, U.S. Pat. No. 5,378,345 “Ceramic solid electrolyte-based electrochemical oxygen concentrator cell” invention patent, using the electrochemistry reaction, and the electrode plate are the multiple electrode plate, however not the porous type metal plate, the operating temperature reaches as high as 800° C., being unable to operate under the normal temperature.
[0008] Therefore, using the electrochemistry oxygen-reduction reaction, the oxygen from the air can be used, and the high-purity oxygen can be obtained to become as the new generation feasible idea and concept. Except decreasing the equipment manufacturing complexity, also the production cost for the equipment can be highly reduced.
SUMMARY OF THE INVENTION
[0009] This invention is related to the assembly apparatus combined by the electrode and the ionic conductor, basically by using the electrochemistry reaction system of the electric potential operation or the electric current operation, as the oxygen maintenance and regulation apparatus.
[0010] As reaction principles for the invention, firstly, using the oxygen from the air in the cathode electrode, carrying out the oxygen reduction reaction, and then the water molecule can be decomposed in the anode electrode for producing the oxygen. By the way of the ionic conductor and the external circuit transmission, the oxygen can be entered to the cathode electrode of this invention apparatus, also the oxygen can be produced in the anode electrode regulating and changing the oxygen of the air, becoming as the oxygen regulation concentrator apparatus.
[0011] By passing of the ionic conductor and the external circuit transmission, the oxygen can enter into the cathode electrode of the invention; also the oxygen can be produced in the anode electrode. The invention will become the controllable apparatus for oxygen production, and as the oxygen concentration controller for changing the oxygen concentration of the air, and for the oxygen of the air entering this invention.
[0012] The electrode of the invention having the different-size hole collection, and respirometric character, provides the oxygen to enter and release the pass way using the hydrophobic material as the hydrophobic interface. This half hydrophilic interface can provide the smooth way for gas entering and leaving, also can avoid the water molecule flood, simultaneously can provide the liquid phase transmission function between the ionic conductor and the electrode surface.
[0013] About the material selection for the electrode of the invention, in the porous cathode electrode, the electricity catalysis catalyst of the oxygen reduction reaction will comprise the noble metal such as platinum, or the metal oxidation LaMnO3, or the M (tmdbta) (Metal-Tetramethyldibenzotetraaza Annulene,) such as CoTMPP. It may cause the oxygen to be adsorbed on the surface, also as the electric conduction materials, can provide the electric potential regulation in order to carry out the chemical reduction reaction.
[0014] About the invention, the porous anode electrode materials will be selected including the Dimensional Stable Anode, DSA, for enhancing the reaction area and being more stable in the oxygen evaluation reaction, OER, also including the metal oxidization such as the ruthenium oxide supported by the titanium oxide. The ion conduction matter for this invention could use the acid solution or the alkali solution, such as KOH, H 2 SO 4 and so on. Under the consideration for the liquid tightness or the gas tightness of the electrode electrolyte combination, also may use the high polymer membrane of the hydrogen ion, or hydroxy ionic conduction using the composite materials pickled with the acid solution or the alkali solution, or the fiber net isolating the anode electrode or the cathode electrode, or the other inert-character materials.
[0015] This invention having the optimization design for the oxygen concentrator, is selected by the hydroxide radical ion conduction materials, also will make the electricity catalysis catalyst of the electrode having the better reaction speed.
[0016] The simple control circuit of the invention, the battery or the other power source all can be used for the oxygen concentrator apparatus of the invention, for conveniently regulating the oxygen supply.
[0017] The design for the oxygen concentrator apparatus of this invention will be the gas diffusible electrode, due to the gas diffusible electrode having the porous structures; therefore, the efficiency reduction caused by the mass transfer can be effective improvement.
[0018] The oxygen concentrator apparatus of this invention using the gas diffusible electrode as the air cathode electrode, the dimensional stable anode (DSA) as the anode producing gas, due to the transition metal having good stability in the anode procedure, therefore selecting the dimensional stable anode as the anode, combined together with the electrolyte.
[0019] This invention is a sort of portable type, can be used under the normal temperature and the atmosphere apparatus, therefore can be applied for the oxygen respirator, the skin covering, the pollution gas isolation and so on, as the oxygen regulation apparatus for the oxygen-need environment.
[0020] The best optimization design for this oxygen concentrator apparatus can be selected by the hydroxide radical ion or the hydrogen conduction materials, carrying out the better reaction speed for the electricity catalysis catalyst of the electrode.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] 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:
[0022] FIG. 1 is schematically illustrating the embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0023] The following is a description of the present invention and the invention will firstly be described with reference to one exemplary structure. Some variations will then be described as well as advantages of the present invention. A preferred method of fabrication will then be discussed; also, an alternate, asymmetric embodiment will then be described along with the variations in the process flow to fabricate this embodiment.
[0024] This invention is the oxygen maintenance and regulation concentrator apparatus, mainly by using an electrochemistry reaction system, combined by the electrode and the ionic conductor, could be operated by the electric potential or the electric current, mainly purpose, also as the apparatus for maintaining oxygen concentration.
[0025] The principle of the invention is an oxygen reduction reaction using the oxygen from the air in the negative pole; also decomposing water molecule in the anode and then producing the oxygen.
[0026] This invention is one sort of portable oxygen maintenance and regulation concentrator apparatus, as FIG. 101 illustrating, using electrochemistry reaction system, including a porous cathode electrode as the first porous electrode, for the oxygen reduction reaction.
[0027] The chemical reaction equation for this porous cathode electrode will be the followings:
[0000] O 2 +2H 2 O+4e − →4OH − ε 0 =0.401V
[0028] As FIG. 102 shows, as the electrolyte hydrogen ionic conductor, could use the alkali or the acid as the ionic conductor, as conducting two of electrodes. Due to the electrode reaction of the invention having the better operation performance in the alkalinity system, thus the organic polymer membrane or the inorganic materials of the hydroxy ionic conductor all can be the electrolyte materials for this system.
[0029] Such as FIG. 103 describing, using a porous anode electrode, as the second porous electrode is provided for the oxygen production reaction. The chemical reaction equation for the porous positive electrode will be the following:
[0000] 4OH − →O 2 +4e − +2H 2 O ε 0 =−0.401V
[0030] As FIG. 101 , the electrode materials for the porous cathode electrode are selected from the oxygen reduction electrode materials that are the sort of compound having the oxygen adsorption function, normally are selected from the noble metal such as the platinum or the carbon supporting metal electricity catalysis catalyst, also could be the metal oxidation having the perovskite-type structure, such as LaMnO3 or its derivational compounds, or the M (tmdbta (Metal-Tetramethyldibenzotetraaza Annulene,) such as FeTMPP, CoTMPP, or FeOEP and so on, as the compound having the oxygen adsorption function.
[0031] In FIG. 103 , the porous anode electrode will be the oxygen reduction electrode structure as the gas respirometric structure, and having the hydrophobic electrode structure as the electrolyte interface of the hydrophilic electrode. Also, this hydrophobic electrode can be the gas entrance access having the hydrophilic-size hole against the water molecule fluid, as the gas porous electrode structure. In addition, as FIG. 103 , the porous anode electrode will be the electrode materials for producing the oxygen, also as the dimensional stable anode. In the oxygen production reaction process, for providing the response electric potential control, as well as due to the structural stability of the materials, the ruthenium oxide supported by the titanium oxide can be selected, or the other electric potential stable metal oxidation produced by the oxygen reaction, including the rutile-type oxidation, the spinel-type oxidation, the perovskite-type oxidation. The previous used titanium oxide can be shaped as mesh shape, or as for the gas dispersing supporting construction for the electrode producing gas. Also, by coating or the other thin film made attachment electrochemistry active materials, or the adherent materials all can be collected, however, the surface character between the different materials must be good electrical conductivity.
[0032] As FIG. 104 shows, the power source control circuit can be used for the oxygen concentrator, and the battery or the other power source can be provided for the power supply and can be processed for the electrochemistry reaction.
[0033] This invention, the previous mentioned cathode electrode and anode electrode can be put on the two sides, as FIG. 102 , the electrolyte ionic conductor can be put into central position between two sides for linking two electrodes, as the whole reaction system. As FIG. 101 , the porous cathode electrode can be the entrance electrode for the oxygen of the air entering. Another electrode, as FIG. 103 , the porous anode electrode can produce the oxygen. FIG. 104 illustrates that power source control circuit can provide the electrical energy and process the electrochemistry reaction, controlling the oxygen amount, as the portable oxygen regulation and support apparatus.
[0034] The oxygen concentration by this invention regulation, at the time the concentration can be maintained either in the higher oxygen concentration or the lower oxygen concentration for the entrance oxygen, so that the ideally regulation effect of the oxygen concentrator can be achieved.
[0035] In the invention, the porous cathode electrode, the porous anode electrode, and the electrolyte material structure must be used by the appropriate manufacturing process and the seal structure, in order to guarantee the surface combination between the electrode materials and the electrolyte materials, as well as the related liquid tightness or the gas tightness structure can be for the gas entering and leaving, and then the isolation electrode electric-circuit for the ionic conductor can be provided for the ion channel function.
[0036] This invention is a sort of portable type apparatus can be used under the normal temperature and atmosphere, therefore can be applied for the oxygen respirator, the skin covering, the pollution gas isolation and so on, as the oxygen regulation apparatus for the oxygen-need environment.
[0037] It is understood that various other modifications will be apparent to and can be readily made by those skilled in the art without departing from the scope and spirit of this invention. Accordingly, it is not intended that the scope of the claims appended hereto be limited to the description as set forth herein, but rather that the claims be construed as encompassing all the features of patentable novelty that reside in the present invention, including all features that would be treated as equivalents thereof by those skilled in the art to which this invention pertains. | The fast and convenient usage of clean and pure oxygen supply devices will meet the requirements of medical application and special environment safety issues. The electrochemical oxygen concentration is a device by using an electrochemical reactor of one electrode of oxygen reduction and another electrode of oxygen generation. The operation of electrochemical reactor can achieve the easy control of air oxygen from one side to another side of this thin mask structure and the materials, design and engineering of this electrochemical oxygen concentration is workable for medical application. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a division of co-pending application Ser. No. 09/704,294, filed Nov. 1, 2000 entitled “PRINTED CIRCUIT BOARD SUPPORT”, and is further related to co-pending application Ser. Nos. 10/375,456, 10/375,275, and 10/375,818, which are all entitled “PRINTED CIRCUIT BOARD SUPPORT”.
BACKGROUND OF THE INVENTION
The present invention relates to printed circuit board handling and manufacturing processes and, more particularly, to an improved printed circuit board support, printed circuit board conveying system, and printed circuit board processing system.
Conventional printed circuit board processing systems, e.g., SMT (surface mount technology) manufacturing systems, typically utilize a conveyor system to move a printed circuit board from station to station within the system. Often, the printed circuit board is supported or held in a manner that is insufficient to prevent the board from warping, twisting, or bending during processing. Accordingly, there is a need in the art of printed circuit board handling and processing for an improved printed circuit board support.
BRIEF SUMMARY OF THE INVENTION
This need is met by the present invention wherein an improved printed circuit board support, an improved printed circuit board conveying system, and an improved printed circuit board processing system are provided. In accordance with one embodiment of the present invention, a printed circuit board support is provided comprising a support base, a spacer, and a spacer securement. The support base defines a support surface. The spacer engages the support surface. The spacer securement includes a projection and a recess. The projection adjoins one of the support base and the spacer. The recess is formed in the other of the support base and the spacer. The projection extends into the recess and the projection and the recess are configured such that the extension of the projection into the recess limits movement of the spacer relative to a plane parallel to the support surface.
The printed circuit board support may comprise two or more spacer securements. The projection may comprise a substantially cylindrical pin and the recess may comprise a cylindrical recess having a diameter slightly larger than the pin. The spacer may define an upper spacer surface spaced from and substantially parallel to the support surface.
In accordance with another embodiment of the present invention, a printed circuit board support assembly is provided comprising a support base and a plurality of spacers. The support base defines a support surface and at least one recess formed therein. The recess defines an opening on the support surface. The plurality of spacers define respective upper spacer surfaces and opposite spacer surfaces. The spacers define a range of respective thickness dimensions between respective ones of the spacer surfaces and corresponding ones of the opposite spacer surfaces. Each of the spacers includes at least one projection extending from the opposite spacer surface. The respective projections and the recess formed in the support base are sized to enable extension of the respective projections into the recess and to limit movement of the spacer relative to a plane parallel to the support surface.
In accordance with yet another embodiment of the present invention, a printed circuit board support is provided comprising a support base. The support base defines a support surface, a leading edge, a trailing edge, and a pair of lateral edges. The support base also defines a cut-out formed therein. The cut-out is positioned between the pair of lateral edges and extends from the leading edge in the direction of the trailing edge to a position between the leading edge and the trailing edge.
The leading edge, the trailing edge, and the pair of lateral edges may be defined in a substantially planar surface of the support base. The cut-out may be formed in the support surface of the support base. The printed circuit board support may further comprise a spacer and a spacer securement. The spacer engaging the support surface and including an additional cut out formed therein and the spacer securement arranged to secure the spacer to the support surface with the additional cut-out aligned with the cut-out formed in the support base. The additional cut-out and the cut-out in the support base may be coextensive. The additional cut out may be formed in an upper spacer surface of the spacer.
In accordance with yet another embodiment of the present invention, a printed circuit board support is provided comprising a support base defining a support surface. A base extension assembly is secured to the support base and is arranged to define a variable extension assembly height dimension and at least a portion of a height dimension of the printed circuit board support, wherein variation of the variable extension assembly height dimension results in variation of the height dimension of the printed circuit board support.
The base extension assembly may be further arranged such that the extension assembly height dimension varies in response to a force applied to the support surface. The base extension assembly comprises a spring-loaded extension including a spring arranged to compress in response to a force applied to the support surface. The base extension assembly may comprise a viscously damped extension arranged to compress in response to a force applied to the support surface. The base extension assembly may comprise a pair of support legs. Each of the pair of support legs may be arranged such that the extension assembly height dimension varies in response to a force applied to the support surface.
In accordance with yet another embodiment of the present invention, a printed circuit board support is provided comprising a support base, a base extension, and a magnetic source. The support base defines a support surface and a lower surface. The base extension is secured to the support base and is arranged to define at least a portion of a height dimension of the printed circuit board support. A magnetic source is secured to the base extension and is positioned such that the lower surface of the support base is arranged to secure the printed circuit board support to an object under magnetic force. The magnetic source may comprise a permanent magnet and may be secured within a cavity formed in the lower surface of the support base.
In accordance with yet another embodiment of the present invention, a printed circuit board conveying system is provided comprising a pair of conveyor rails and a printed circuit board support. The pair of conveyor rails are positioned to engage opposite lateral edge portions of a printed circuit board and are configured to convey the printed circuit board along a conveyor path. The printed circuit board support is positioned to support a portion of the printed circuit board between the lateral edge portions. The printed circuit board support comprises a support base defining a support surface, a spacer engaging the support surface, and a spacer securement including a projection and a recess. The projection adjoins one of the support base and the spacer. The recess is formed in the other of the support base and the spacer. The projection extends into the recess. The projection and the recess are configured such that the extension of the projection into the recess limits movement of the spacer relative to a plane parallel to the support surface. A thickness dimension of the spacer is selected to enable engagement of the spacer with the printed circuit board.
In accordance with yet another embodiment of the present invention, a printed circuit board conveying system is provided comprising a pair of conveyor rails, a printed circuit board support, and a stop mechanism. The pair of conveyor rails are positioned to engage opposite lateral edge portions of a printed circuit board and are configured to convey the printed circuit board along a conveyor path. The printed circuit board support is positioned to support a portion of the printed circuit board between the lateral edge portions and comprises a support base. The support base defines a support surface, a leading edge, a trailing edge, a pair of lateral edges, and a cut-out formed therein. The cut-out is positioned between the pair of lateral edges and extends from the leading edge in the direction of the trailing edge to a position between the leading edge and the trailing edge. The stop mechanism is positioned to engage the printed circuit board support at a point within the cut-out. The stop mechanism may include an actuator and a pin and may be configured to selectively extend and retract the pin to and from a position engaging the printed circuit board support at the point within the cut-out.
In accordance with yet another embodiment of the present invention, a printed circuit board conveying system is provided comprising a pair of conveyor rails and a printed circuit board support. The pair of conveyor rails are positioned to engage opposite lateral edge portions of a printed circuit board and configured to convey the printed circuit board along a conveyor path. The printed circuit board support is positioned to support a portion of the printed circuit board between the lateral edge portions and comprises a support base and a base extension assembly. The support base defines a support surface. The base extension assembly is secured to the support base and is arranged to define a variable extension assembly height dimension and at least a portion of a height dimension of the printed circuit board support.
Variation of the variable extension assembly height dimension results in variation of the height dimension of the printed circuit board support. The base extension assembly is configured such that the height dimension of the printed circuit board support permits engagement of the support surface with the printed circuit board.
In accordance with yet another embodiment of the present invention, a printed circuit board conveying system is provided comprising a pair of conveyor rails, a conveyor platform, and a printed circuit board support. The pair of conveyor rails are positioned to engage opposite lateral edge portions of a printed circuit board and are configured to convey the printed circuit board along a conveyor path. The printed circuit board support is positioned to support a portion of the printed circuit board between the lateral edge portions. The printed circuit board support comprises a magnetic source secured to the base extension assembly and positioned such that the lower surface of the support base secures the printed circuit board support to the conveyor platform under magnetic force, wherein the base extension assembly is configured such that the height dimension of the printed circuit board support permits engagement of the support surface with the printed circuit board.
In accordance with yet another embodiment of the present invention, a printed circuit board processing system is provided. The system includes a printed circuit board conveying system coupling a printed circuit board loader to a stencil printer, a pick and place machine, and a reflow oven. The printed circuit board conveying system comprises a pair of conveyor rails and a printed circuit board support according to the present invention.
In accordance with yet another embodiment of the present invention, a method of conveying a printed circuit board in a printed circuit board conveying system is provided. The conveying system is provided in accordance with the present invention and the conveying method comprises the steps of selecting one of the plurality of spacers as a function of its thickness and a thickness profile of the printed circuit board engaged by the pair of conveyor rails; installing the selected spacer by extending at least one of the respective projections into the recess; and engaging an upper spacer surface of the selected spacer with the printed circuit board.
In accordance with yet another embodiment of the present invention, a method of conveying a printed circuit board in a printed circuit board conveying system is provided. The conveying system is provided in accordance with the present invention and the conveying method comprises the steps of engaging the support surface of the support base with the printed circuit board engaged by the pair of conveyor rails and varying the height dimension of the base extension assembly as a function of a thickness profile of the printed circuit board.
In accordance with yet another embodiment of the present invention, a method of processing a printed circuit board in a processing system including a printed circuit board conveying system coupling a printed circuit board loader to a stencil printer, a pick and place machine, and a reflow oven is provided. The printed circuit board conveying system is provided in accordance with the present invention and the processing method comprises the steps of selecting one of the plurality of spacers as a function of its thickness and a thickness profile of the printed circuit board engaged by the pair of conveyor rails, installing the selected spacer by extending at least one of the respective projections into the recess, and engaging an upper spacer surface of the selected spacer with the printed circuit board within the operating envelope of the pick and place machine.
In accordance with yet another embodiment of the present invention, a method of processing a printed circuit board in a processing system including a printed circuit board conveying system coupling a printed circuit board loader to a stencil printer, a pick and place machine, and a reflow oven is provided. The printed circuit board conveying system is provided in accordance with the present invention and the processing method comprises the steps of engaging the support surface of the support base with the printed circuit board engaged by the pair of conveyor rails within the operating envelope of the pick and place machine and varying the height dimension of the base extension assembly as a function of a thickness profile of the printed circuit board.
Accordingly, it is an object of the present invention to provide an improved printed circuit board support, an improved printed circuit board conveying system, and an improved printed circuit board processing system. Other objects of the present invention will be apparent in light of the description of the invention embodied herein.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
The following detailed description of the preferred embodiments of the present invention can be best understood when read in conjunction with the following drawings, where like structure is indicated with like reference numerals and in which:
FIG. 1 is an illustration of a printed circuit board support according to/one embodiment of the present invention;
FIG. 2 is an illustration of a printed circuit board support according to another embodiment of the present invention;
FIG. 3 is an illustration of a printed circuit board support according to yet another embodiment of the present invention;
FIG. 4 is an illustration of a printed circuit board conveying system according to the present invention; and
FIG. 5 is an illustration of a printed circuit board processing system.
DETAILED DESCRIPTION
Referring now to FIGS. 1-5 a printed circuit board support 5 , printed circuit board conveying system 60 , and a printed circuit board processing system 70 according to the present invention are illustrated. The printed circuit board support 5 illustrated in FIG. 1 comprises a support base 10 defining a support surface 12 . A base extension assembly 20 is secured to the support base 10 . The base extension assembly 20 may be secured to the support base 10 by forming the extension assembly 20 and the support base 10 as a single integral piece or by coupling two separate pieces mechanically, adhesively, magnetically, or otherwise.
The support base 10 defines a leading edge 14 , a trailing edge 16 , and a pair of lateral edges 18 . As is illustrated in FIG. 1 , the leading edge 14 , the trailing edge 16 , and the pair of lateral edges 18 are defined in a substantially planar support surface 12 of the support base 10 . In the illustrated embodiment, the base extension assembly 20 comprises a pair of support legs 22 , 24 .
According to one embodiment of the present invention, a cut-out 15 is formed in the support base 10 . The cut-out 15 is positioned between the pair of lateral edges 18 and extends from the leading edge 14 in the direction of the trailing edge 16 to a position between the leading edge 14 and the trailing edge 16 . In the illustrated embodiment, the cut-out 15 is formed in the support surface 12 of the support base 10 . The purpose of the cut-out 15 is illustrated in further detail herein with reference to the function of the conveying and processing systems of the present invention.
Referring specifically to FIGS. 1 and 2 , the printed circuit board support 5 may further comprise a pair of permanent magnets 30 secured within respective cavities in each of the support legs 22 , 24 of the base extension 20 . The magnets 30 are positioned such that the lower surface of the support base 10 is arranged to secure the printed circuit board support 5 to a conveyor platform or other object 40 under magnetic force. Alternative magnetic sources 30 , e.g., electromagnets, may be provided without departing from the scope of the present invention.
The base extension assembly 20 may comprise a single molded piece with or without attachments or, as is illustrated in FIG. 3 , may comprise a compound assembly arranged to define a variable height dimension a of the extension assembly 20 and at least a portion of a height dimension b of the printed circuit board support 5 . As will be appreciated by those practicing the present invention, variation of the variable extension assembly height dimension a results in variation of the height dimension b of the printed circuit board support 5 .
The extension assembly 20 illustrated in FIG. 3 may comprise a spring arranged to compress in response to a force applied to the support surface 12 , a viscously damped extension arranged to compress in response to a force applied to the support surface 12 , or any other components arranged to enable variation of the height dimension a of the extension assembly 20 . The variation of the height dimension a may be in response to a force applied to the support surface 12 or may be a result of selective control of the height dimension a independent of the force applied to the support surface 12 . In the illustrated embodiment, each of the pair of support legs 22 , 24 are arranged, in the manner described herein, such that the extension assembly height dimension is variable.
Referring further to FIG. 2 , an additional embodiment of the present invention is illustrated. A spacer 50 is provided in engagement with the support surface 12 . A spacer securement 52 includes a recess 54 in the form of a cylindrical bore and a projection 56 in the form of a pin. In the illustrated embodiment, the pin 56 is mounted to or formed integrally with the spacer 50 and the recess 54 is formed in the support base 10 . It is contemplated, however, that the pin 56 may be mounted to the support base 10 and the recess 54 may be formed in the spacer 50 .
In the engaged state, the projection 56 extends into the recess 54 and the projection 56 and the recess 54 are configured such that the extension of the projection 56 into the recess 54 limits movement of the spacer 50 relative to a plane parallel to the support surface 12 . As is illustrated in FIG. 2 , the printed circuit board support 5 may comprise at least two spacer securements 52 .
The spacer 50 functions to provide an upper spacer surface 58 spaced from and substantially parallel to the support surface 12 . As clearly illustrated in FIGS. 2 and 4 , the upper spacer surface 58 is sized and configured to support and engage a major portion of a printed circuit board 80 . Most preferably a plurality of spacers of different thicknesses are made available for engagement with the support base 10 . In this manner, the printed circuit board support 5 may be configured to support a variety of printed circuit boards of varying thickness profiles.
In the embodiment illustrated in FIG. 2 , the spacer 50 engaging the support surface 12 includes an additional cut out 55 formed therein. The spacer securements 52 are arranged to secure the spacer 50 to the support surface 12 with the additional cut-out 55 aligned with the cut-out 15 formed in the support base 10 . Typically, the additional cut-out 55 and the cut-out 15 in the support base 10 are coextensive, i.e., they have substantially the same spatial scope or boundaries. Moreover, as clearly illustrated in FIGS. 1-3 , the cut-out 15 transects the thickness of the support base 10 and, as clearly illustrated in FIG. 2 , the additional cut-out 55 transects the thickness of the spacer 50 . The additional cut out 55 is formed in an upper spacer surface 58 of the spacer 50 . The upper surface 58 of the spacer 50 and the support surface 12 collectively define a pair of supportive extensions 25 which provide additional support for printed circuit boards that extend across the cut-out 15 and the additional cut-out 55 .
Referring now to FIGS. 4 and 5 , a printed circuit board conveying system, a printed circuit board processing system, and their manners of operation are described. A printed circuit board conveying system 60 is incorporated within the processing system 70 and includes a conveyor 62 coupling a printed circuit board loader 72 to a stencil printer 74 , a pick and place machine 76 , and a reflow oven 78 . The printed circuit board conveying system 60 comprises a pair of conveyor rails 64 positioned to engage opposite lateral edge portions 82 of a printed circuit board 80 and is configured to convey the printed circuit board 80 along a conveyor path, as indicated by directional arrow 66 . A printed circuit board support 5 according to the present invention is positioned to support a major portion of the printed circuit board 80 between the lateral edge portions 82 within an operating envelope of the pick and place machine 76 . It is contemplated by the present invention that the printed circuit board support 5 may be positioned to support a major portion of the printed circuit board 80 within the respective operating envelopes of other components of the processing system 70 as well.
A stop mechanism 90 is illustrated in FIG. 4 , and includes an actuator 92 and a pin 94 . The stop mechanism 90 is configured to selectively extend and retract the pin 94 to and from a position engaging the printed circuit board support 5 at a point within the cut-out 15 . In this manner, the stop mechanism 90 may be utilized to control the movement of selected printed circuit board supports 5 along the conveyor path.
In operation, one of a plurality of spacers 50 (See FIG. 2 ) having different thicknesses is selected depending upon the thickness profile of the printed circuit board 80 engaged by the pair of conveyor rails 64 . More specifically, the spacer 50 having a thickness most suitable for optimum supportive engagement of the printed circuit board 80 by the printed circuit board support 5 is selected. The selected spacer 50 is installed by extending or positioning the respective projections 56 into the corresponding recesses 54 . The upper spacer surface 58 of the selected spacer 50 is then utilized to engage the printed circuit board 80 within the operating envelope of the pick and place machine 76 . Alternatively, the spacer 50 may be eliminated and the base extension assembly 20 may be arranged to define a variable extension assembly height dimension a, as discussed herein with reference to FIG. 3 , and the height dimension of the base extension assembly 20 may be varied as a function of a thickness profile of the printed circuit board 80 . In which case the upper surface 12 will engage the printed circuit board 80 . It is contemplated that the variable height base extension assembly 20 and the spacers 50 may be utilized in a cooperative relationship in a single embodiment of the present invention.
Having described the invention in detail and by reference to preferred embodiments thereof, it will be apparent that modifications and variations are possible without departing from the scope of the invention defined in the appended claims. More specifically, although some aspects of the present invention are identified herein as preferred or particularly advantageous, it is contemplated that the present invention is not necessarily limited to these preferred aspects of the invention. | A printed circuit board conveying and processing system. In accordance with the present invention, a printed circuit board conveying system is provided comprising a pair of conveyor rails and a printed circuit board support. The conveyor rails are positioned to engage opposite lateral edge portions of a printed circuit board along a conveyor path. The printed circuit board support is positioned to support a major portion of the printed circuit board between the lateral edge portions. It is emphasized that this abstract is provided to comply with the rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. 37 CFR §1.72(b). | 8 |
BACKGROUND OF THE INVENTION
This invention relates generally to tacky polymeric microspheres, and has particular reference to inherently tacky, elastomeric, solvent-dispersible, solvent-insoluble, polymeric microspheres and a process for preparing same using a non-ionic emulsifier.
In U.S. Pat. No. 4,166,152, granted Aug. 28, 1979 to W. A. Baker et al, there is a disclosure of inherently tacky acrylate homopolymer microspheres prepared by aqueous suspension polymerization techniques utilizing a suspension stabilizer and an anionic emulsifier. The microspheres prepared by this method had an average particle size of 10-60 microns. While the inherently tacky microspheres disclosed by Baker have desirable properties for certain applications, it has been found that anionic emulsifiers retard particle coalescence by surrounding the particle with a charged double layer. This coulombic barrier of the anionic emulsifiers is sensitive to electrolytes and freezing, and sensitivity to freezing can be a disadvantage in cold weather shipments and during storage.
Other pertinent prior patents of which the applicant is aware are U.S. Pat. Nos. 3,513,120; 3,691,140; 3,857,731; 4,049,483 and 4,049,604.
SUMMARY OF THE INVENTION
The present invention is directed to inherently tacky microspheres having similar properties to those disclosed by the Baker patent but which are prepared using a non-ionic emulsifier. The tacky microspheres provided by the invention are particularly adapted for use as a low tack microsphere glue that can be applied to a sheet material substrate whereby the latter is provided with a reusable adhesive surface.
It has been found that the use of non-ionic emulsifiers imparts unique and desirable characteristics to microsphere adhesives. Thus, the utilization of a non-ionic emulsifier in the emulsion operates to surround the microspheres with a hydrated layer of surfactant that acts as a steric barrier to particle coalescence and this in turn results in an end product that is considerably more resistant to freezing than products prepared using an anionic emulsifier. Samples of the inherently tacky microspheres disclosed by the invention have been exposed to freeze/thaw cycles as have samples of the mircospheres taught by the Baker patent. In these tests, the Baker microspheres coagulated upon freezing and did not redisperse when thawing occurred whereas microspheres prepared according to the invention did not coagulate.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In the present invention, the low tack microsphere glue is essentially comprised of inherently tacky, elastomeric, solvent-dispersible, solvent-insoluble, polymeric microspheres (having an average particle size of 20-60 microns) prepared using a non-ionic emulsifier. The microspheres are derived from non-ionic monomers and include a water emulsifiable methacrylate ester or alkyl acrylate. The microspheres are prepared by aqueous suspension polymerization techniques using a suspension stabilizer and, as noted, a non-ionic emulsifier.
In a preferred embodiment of the invention, the monomer is 2-ethylhexyl acrylate, the stabilizer is an aqueous solution of polyacrylic acid, and the non-ionic emulsifier is an oleyl alcohol ethoxylate. A catalyst is also employed in the polymerization of the monomer, the catalyst being a benzoyl peroxide in the preferred embodiment.
EXAMPLE 1
To a five liter, 3-necked flask equipped with thermometer, mechancial stirrer, reflux condenser, and vacuum and nitrogen inlet tube, were added 2820 grams of deionized or distilled water and 54 grams of Carbopol EX-17 (trademark for a 15% active aqueous solution of polyacrylic acid of 300,000-500,000 molecular weight range commercially available from the B. F. Goodrich Co.). The contents of the flask were then mixed to dissolve the EX-17. Concentrated ammonium hydroxide was then added to the mixture until a pH of 7.0 was achieved.
To this solution were added 3.7 grams of Lucidol-70 (trademark for a 70% active benzoyl peroxide in water; granular, bulk density--55 lbs/ft. 3 , freezing point less than 32° F.; commercially available from Lucidol Division, Penwalt Corp.) and 1000 grams of 2-ethylhexyl acrylate. Vacuum was then placed on the contents of the flask, the pressure therein being drawn to approximately 25 inches of mercury, and held for five minutes (while the mixture is stirred via vacuum tight stir assembly) to assure removal of dissolved air and oxygen. The vacuum was then broken with nitrogen. A nitrogen purge was maintained throughout the emulsion and polymerization steps. Added to the mixture was 21.5 grams of "Trycol OAL-23" (trademark for an oleyl alcohol ethoxylate (23 average moles of ethylene oxide), non-ionic surfactant; solid, m.p.--47° C., color gardner--2, cloud point 5% saline--89° C., flash point--440° C.; commercially available from Emery Indusries, Inc.). Agitation for the mixture was set at 300 ppm.
The batch was then heated to 60° C. and maintained for 16 hours. As the temperature initially approached 60° C., a mild exotherm was noted which raised the temperature to approximately 70° C. After the 16 hour period, the suspension was passed through a 250 micron screen. The resultant homopolymer contained approximately 26.9% solids. Upon standing, the polymer spheres creamed to the surface, but were readily dispersed by agitating the mixture. Particle size ranged from 15-60 microns, with the average size approximately 35 microns.
EXAMPLES 2-6
These examples were prepared using the same equipment, monomer, stabilizer and procedures as outlined in Example 1. Each example illustrates the successful use of a non-ionic emulsifier in preparation of the microspheres.
______________________________________ Particle Size.sup.1Example Non-ionic Emulsifier Range Avg. Tack.sup.2______________________________________2 30 g Siponic F-300 20-80 60 85 (Alcolac, Inc.)3 120 g Siponic F-300 10-70 40 954 30 g Brij 98 15-40 30 72 (ICI, Americas, Inc.)5 15 g L-12 10-50 35 83 (Alcolac, Inc.)6 21 g L-12 5-35 20 82______________________________________ .sup.1 Particle sizes were determined by microscopic examination. .sup.2 Tack levels were determined by testing samples of coated microspheres on paper backing with a Polyken, Jr. Probe Tack tester (manufactured by Testing Machines, Inc. under license from the Kendall, Corp.). Coating was accomplished by drawdowns using a No. 20 wirewound rod. Values represented herein are averages obtained from several testing of the coated paper. The conditions of the tack testing are as follows:
Contact time: 1 secondSeparation time: 1 cm/secContact pressure: 100 gm/cm.sup.2Probe type: 1/2 cm diameter 304 stainless steel tip-28 0 grit abrasive finishTemperature: approx. 22.5° C.
Further information on the Polyken probe tack tester may be found in ASTM D29 79 Section 15.06, 1983.
In examples 2-6 above, the SIPONIC F-300 is polyethylene octylphenol ether--30 moles of ethylene oxide, 70% active ingredient, 1.095 spec. gravity at 25° C., cloud point--1% solution--greater than 100° C., 7-9 pH--5% solution, +2° C. pour point, 17.3 HLB value, greater than 150° C. flash point; available from Alcolac, Inc. The BRIJ 98 is polyethylene oleyl ether--20 moles of ethylene oxide, cream solid, 23° C. pour point, 15.3 HLB value; available from ICI Americas Inc. The "L 12" is polyethylene lauryl alcohol ether--12 moles of ethylene oxide, 100% active ingredient, 90° C. cloud point in 1% NaCl, 6.5 pH in 1% solution, 14.5 HLB value; available from Alcolac, Inc.
From the foregoing description it will be apparent that the invention provides an improved low tack microsphere glue having advantages over the prior art. As will be understood by those familiar with the art, the invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. | Inherently tacky, elastomeric, solvent-dispersible, solvent-insoluble, polymeric microspheres prepared using a non-ionic emulsifier. The tacky microspheres are particularly adapted for use as a low tack microsphere glue that can be applied to a sheet material substrate whereby the latter is provided with a reusable adhesive surface. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a U.S. national stage application of International Application No. PCT/EP2006/067612 filed Oct. 20, 2006, which designates the United States of America, and claims priority to German application number 10 2005 051 289.5 filed Oct. 26, 2005, the contents of which are hereby incorporated by reference in their entirety.
TECHNICAL FIELD
[0002] The present invention relates to a piezoelectric actuator, preferably of monolithic multilayer construction, and to a method for producing the same.
BACKGROUND
[0003] Piezoelectric actuators usually consist of a number of piezoelectric elements arranged in a stack. Each of these elements in its turn consists of a piezoceramic layer on both sides of which metallic electrodes are provided. If a voltage is applied to these electrodes, the piezoceramic layer reacts with a lattice distortion, which leads along a main axis to a usable length expansion. Since this in its turn amounts to less than 2 thousandth of the layer thickness along the main axis, to achieve the desired absolute length expansion a correspondingly greater layer thickness of active piezoceramic must be provided. However, as the layer thickness of the piezoceramic layer of an individual piezoelectric element increases, the voltage required for the piezoelectric element to respond also increases. To keep this within manageable limits, the thicknesses of individual elements usually lie between 20 and 200 μm. A multilayer piezoelectric actuator must therefore have a corresponding number of individual elements or layers for a desired length expansion.
[0004] Known multilayer piezoelectric actuators thus generally consist of numerous individual layers in total. To produce said actuators, piezoceramic layers are arranged alternately with electrode material to form a stack and are laminated and sintered together to form a monolithic assembly. Such a method is known for example from European patent EP 0 894 340 B1. In this patent an electrode material is printed onto piezoceramic green tapes. The printing is undertaken in accordance with a pattern, which includes printed areas and non-printed areas left free. The electrode layers are stacked alternately such that a surface printed with electrode material in the next adjacent second electrode layer is arranged over each unprinted area in a first electrode layer. The alternating arrangement means that every second electrode layer covers the same area in relation to its pattern of electrodes. In the intermediate electrode layers, which also cover the same area, the unprinted areas left free are offset diagonally.
[0005] In this approach in accordance with the prior art however the disadvantageous fact has emerged that during sintering, an internal pressure and volume equalization occurs, with for example the unprinted areas left free in the electrode pattern being completely filled by ceramic material of the adjacent ceramic layers. During an electrical contacting of the electrode layers all ceramic layers undergo an expansion, with the exception of the corner areas comprising the unprinted areas, since no effective electrical field strength can be built up in these two diagonally-opposite areas. By contrast with the rest of the ceramic areas, these corner areas thus do not experience any expansion on activation, which means that mechanical stresses occur between the active areas and the inactive areas. These mechanical stresses cause cracks to form which can start from the inactive corner areas and extend into the active ceramic areas. Such cracks can propagate in an unchecked way through the ceramic in a longitudinal direction as well and considerably reduce the service life of the piezoelectric actuator.
[0006] The process of integrating stress-relieving layers into the stack in accordance with a predetermined alternating sequence of ceramic and electrode layers in order to create predetermined separation areas to reduce mechanical stresses is known to the inventor.
[0007] In this approach however the fact that the incorporation of additional stress-relieving layers involves an additional production effort and additional production costs has proved disadvantageous. In addition these stress-relieving layers disadvantageously increase the size of the stack.
[0008] Further measures are also known to the inventor for reducing mechanical stresses in the piezoelectric actuator, which however do not prevent the formation of cracks in general but merely a formation of cracks in a longitudinal direction of the piezoelectric actuator, which means that the function of the piezoelectric actuator is largely preserved. Despite this, there is also the risk with these measures of unchecked crack propagation resulting from residual transverse cracks, which reduces the power of the piezoelectric actuator or can possibly even destroy it.
SUMMARY
[0009] A piezoelectric actuator and a production method for the same can be specified, with polarization cracks being reduced or minimized despite inactive zones in the electrode layers.
[0010] According to an embodiment, a method for producing a piezoelectric actuator, may comprise the following steps: Providing a number of layers of piezoelectric material able to be assembled into a stack; Application of electrode layers comprising a recess in each case to the number of layers of piezoelectric material such that an alternating sequence of layers of piezoelectric material and electrode layers is produced in the stack, with electrode layers being provided alternately in the stack with a recess in a first recess zone and electrode layers with a recess in a second zone differing from the first recess zone; and Provision of a stress-relieving material in the first and second recesses, which, after the stack is sintered, exhibits properties of electrical insulation and properties of preventing the adhesion of the individual material layers.
[0011] According to a further embodiment, a metallization paste containing a noble metal with a low diffusion capability of the electrically-conductive particles during sintering of the stack, for example a paste containing silver-palladium, may be printed as electrode layers onto the number of layers of piezoelectric material in each case. According to a further embodiment, a paste containing noble metals with a very high diffusion capability of the electrically-conductive particles during sintering of the stack, for example a paste containing silver, may be printed into the recesses as stress-relieving material. According to a further embodiment, ceramic green tapes may be used as layers of piezoelectric material. According to a further embodiment, each second electrode layer may be embodied in the stack with a recess in a first corner zone and each electrode layer provided between said layers may be embodied with a recess in a second corner zone lying opposite the first corner zone. According to a further embodiment, the piezoelectric actuator may be embodied with at least two holes running in a longitudinal direction, with the recesses of the first recess zone in the area of the one hole and the recesses of the second recess zone in the area of the other hole in the stack being provided in an alternating sequence, with the holes being able to be linked in each case with an electrical contacting.
[0012] According to another embodiment, a piezoelectric actuator may comprise a number of layers of piezoelectric material assembled into a stack; and electrode layers, which are applied in each case to the number of layers of piezoelectric material such that an alternating sequence of piezoelectric material layers ( 2 ) and electrode layers is produced in the stack; and electrode layers being provided with a stress-relieving recess in a first recess zone and electrode layers with a stress relieving recess in a second recess zone differing from the first recess zone alternating in the stack.
[0013] According to a further embodiment, the electrode layers may consist of a metallization paste containing a noble metal with a low diffusion capability of the electrically-conductive particles during sintering of the stack, for example made of a paste containing silver-palladium. According to a further embodiment, the number of layers of piezoelectric material may be embodied as ceramic green tapes. According to a further embodiment, each second electrode layer in the stack may feature a stress-relieving recess in a first corner area and each electrode layer provided between said layers may features a stress-relieving recess in a second corner area lying opposite the first corner area. According to a further embodiment, the piezoelectric actuator features at least two holes running in a longitudinal direction, with the recesses of the first recess zone in the area of the one hole and the recesses of the second recess zone in the area of the other holes in the stack being provided in alternating sequence, with the holes being able to be linked in each case with an electrical contacting.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The invention is described in more detail below on the basis of the exemplary embodiments specified in the schematic figures of the drawing. The figures show:
[0015] FIG. 1 an exploded view of a number of ceramic layers able to be assembled into a stack with electrode layers applied in accordance with an exemplary embodiment;
[0016] FIG. 2 the exploded view from FIG. 1 with stress-relieving material applied in the recesses in accordance with an exemplary embodiment; and
[0017] FIG. 3 a perspective view of a piezoelectric actuator in assembled monolithic multilayer construction in accordance with an exemplary embodiment.
[0018] In the figures the same reference symbols designate the same components or those with the same functions, unless stated to the contrary.
DETAILED DESCRIPTION
[0019] According to various embodiments, the piezoelectric actuator is constructed from a number of layers of piezoelectric material able to be assembled into a stack, with electrode layers with a recess in each case being applied to the number of layers of piezoelectric material such that in the stack an alternating sequence of layers of piezoelectric material and electrode layers is produced, with electrode layers with a recess in a first recess zone and electrode layers with a recess in a second recess zone differing from the first recess zone being provided alternately in the stack. Further a stress-relieving material is provided in the first and second recesses respectively, which exhibits electrically-insulating properties and properties which cause the individual layers of material not to adhere to each other after the stack is sintered.
[0020] The various embodiments thus have the advantage over the known approaches that the free areas or recesses of the electrode layers provided are not completely filled with ceramic material during sintering of the stack, but because of the non-adhering properties of the stress-relieving material, create a mechanical separation point or stress-relieving recess between two consecutive ceramic layers in the zone of the recesses. In the event of a diffusion of the stress-relieving material having a high diffusion capability during the sintering the separation points are embodied as hollow spaces between adjacent ceramic layers. This means that there is no adhesion between the ceramic layers in this zone, so that no significant mechanical stresses can occur in these inactive zones. The mechanical stresses—if present at all—do not expand further to form damaging cracks.
[0021] Furthermore the various embodiments have the advantage that, in the recess zones, because of the electrically-insulating properties of the stress-relieving material, electrically-insulated areas are produced, which guarantee an external metallization of the piezoelectric actuator for an electrical activation of each second electrode layer in a simple and cost-effective manner.
[0022] In addition no new technology need by introduced for producing the piezoelectric actuator according to various embodiments, for example, the widely-used and previously-known production facilities and production processes can be used with some modifications, for example, the application of the stress-relieving material to the recess zones. This means that overall damaging cracks in the ceramic layers can be prevented or minimized in a simple and cost-effective manner.
[0023] In accordance with a preferred development a metallization paste containing noble metal with low diffusion capabilities of the electrically-conductive particles is printed onto the piezoelectric material layers as electrode layers during sintering of the stack. For example a paste containing silver-palladium is used, with the proportion of palladium ensuring that the silver remains in the paste and the proportion of silver ensuring a good electrical conductivity of the paste.
[0024] In accordance with a further preferred development a paste containing noble metal with a high diffusion capability of the electrically-conductive particles is printed onto the recesses as stress-relieving material during sintering of the stack. For example a paste containing silver is used, with the silver being diffused during sintering into the adjacent electrode areas.
[0025] In accordance with a further preferred exemplary embodiment, each second electrode layer in the stack is embodied with a recess in a first corner area and each electrode layer provided between said layers is embodied with a recess in a second corner area apposite to the first corner area. In this way a cost-effective and simple external contacting can be guaranteed such that a metallization is provided over the entire longitudinal extent of the piezoelectric actuator in the corner areas, with only each second electrode layer being contacted and thus electrically activated.
[0026] In accordance with a further preferred development the piezoelectric actuator is embodied with at least two holes running in a longitudinal direction, with the first recess zone being provided in the area of one hole and the second recess zone being provided in the area of the other hole in the stack in an alternating sequence. For example the individual electrode layers can be coupled via the holes with an electrical contacting such that once again only each second electrode layer is electrically contacted for each hole. The two holes typically, but not necessarily, have a relatively large diameter in the mm range since, because it is too stiff, a massive wire cannot simply be soldered in, but instead a wire featuring very fine wires (e.g. similar to a bottle brush) can be used.
[0027] The piezoelectric actuator according to various embodiments and the method of constructing it are generally independent of the materials used. Any PZT (lead-zirconate-titanate) ceramics can be used for example as piezoelectric material layers. For example so called green tapes are drawn or cast from this material, which have a thickness of for example 20 to 200 μm after drying.
[0028] After the green tapes have been dried these are provided with electrode layers, for example printed with a suitable silver-palladium paste. The paste preferably contains the particles of a silver/palladium alloy in a binder with a printable consistency overall. This screen printing paste, as well as organic aids, typically features fine-grain silver powder and palladium powder. The proportion of silver in the paste guarantees the good electrical conductivity of the electrode layer after sintering, whereas the palladium proportion guarantees that, despite the high diffusion capability of the silver at the temperature occurring during a sintering, this remains in the printed electrode layer. With a diffusion during the sintering, if palladium is present, the silver contained in the paste reaches an even distribution in concentration in the palladium. The diffusion capability of palladium is small enough for this not to require further consideration.
[0029] FIG. 1 illustrates an exploded view of four piezoelectric ceramic layers 2 , which are each printed on one side with an electrode layer 3 , for example made of the silver-palladium paste described above. Although just four ceramic layers are illustrated in FIGS. 1 and 2 by way of example, it is obvious to the person skilled in the art that any number of piezoelectric ceramic layers can be connected to each other in a stack in a similar manner.
[0030] As can also be seen in FIG. 1 , the ceramic layers 2 are printed in accordance with a pattern such that a printed electrode area 3 and an unprinted, recess zone 4 or 4 ′ which remains free is provided on each ceramic layer. For example for the electrode layers 3 as much of the silver-palladium paste is printed onto one side on the assigned ceramic layers 2 for a 2-3 μm thickness of contiguous electrode layer 3 to be produced after the sintering.
[0031] The piezoceramic layers 2 printed with the electrode material are dried if necessary and subsequently stacked above one another in a suitable manner, with an alternating arrangement of piezoceramic layers 2 and electrode layers 3 being produced.
[0032] For the electrode layers 3 the stacking is likewise alternating such that over each recess 4 or 4 ′ in a first electrode layer which corresponds to the unprinted electrode areas 4 or 4 ′, a surface printed with electrode material is arranged in the next adjacent electrode layer, as can be seen in FIG. 1 . In the exemplary embodiment shown in FIG. 1 the recesses 4 or 4 ′ are each provided alternately in diagonally-opposite corner areas. It is however obvious for a person skilled in the art that the recesses 4 or 4 ′ can also be provided at any other point in an alternating sequence on the ceramic layers.
[0033] The alternating arrangement means that each second layer covers the same area as regards its electrode pattern with the recesses 4 provided. In the intermediate layers likewise arranged to cover the same area the recesses 4 ′ are arranged offset in relation to the recesses 4 .
[0034] In this manner a stack is embodied from as many individual layers arranged above one another as to obtain a desired total height of the piezoelectric actuator.
[0035] Subsequently, in accordance with an exemplary embodiment, in addition to each silver-palladium printing, an additional print process is conducted in which a silver paste 5 is printed into the recesses 4 or 4 ′, as illustrated schematically in FIG. 2 . Thus only the recesses 4 or 4 ′ of the recess zones are printed with the silver paste 5 , with the further production process remaining unchanged. Consequently each layer consists of an electrode area 3 printed with a silver-palladium paste and a recess zone printed with a silver paste 5 .
[0036] After a suitable orientation and stacking of the individual layers, a sintering is undertaken for example under light pressure in an oxidizing atmosphere for a predefined period and at a predefined sinter temperature, which can amount to more than 1000° C. for example. During the sintering the silver in the silver-palladium paste reaches an even distribution in concentration in the palladium through diffusion because of the presence of the palladium. This means that the silver stays in the electrode zones 3 which have a proportion of palladium.
[0037] By contrast with this, the silver in the silver paste 5 diffuses into the recesses 4 or 4 ′ because of its high diffusion capabilities almost completely out of the recess zones 4 or 4 ′ and into the adjacent silver-palladium electrode zones 3 . Through the diffusion of the silver from the recess zones 4 or 4 ′ into the adjacent electrode layers 3 stress-relieving recesses 6 or 6 ′ are embodied in the areas of the recesses 4 or 4 ′, as is indicated schematically in FIG. 3 by the broken lines.
[0038] The recess zones which include the recesses 4 or 4 ′, because of the diffusion of the electrically-conductive silver particles, exhibit electrically-insulating or electrically non-conductive characteristics which is required for a subsequent outside contacting of only every second layer. This enables the proven and widely used contacting technology of the piezoelectric actuator to be retained unchanged.
[0039] Furthermore two adjacent electrode layers in the recess zones 4 or 4 ′, because of the stress-relieving recesses 6 and 6 ′ created, do not adhere to each other in this area, since in accordance with the present exemplary embodiment in each of the two diagonally-opposite corner areas after each second layer a separation point occurs caused by the diffused-out silver paste. Consequently no significant mechanical stresses can arise between the inactive recess zones 4 or 4 ′ and the active areas featuring the electrode layers 3 of the piezoceramic during a polarization of the piezoelectric actuator 1 .
[0040] FIG. 3 illustrates a perspective view of a finished piezoelectric actuator 1 , which is contacted in the form of strips with an external metallization 8 for electrical contacting at corners opposite one another. Because of the electrode structure which alternates from individual layer to individual layer this type of external contact 8 only reaches every second electrode layer, whereas the external contact 8 attached at the opposite edge contacts the intermediate electrode layers in each case. This means that an electrically-parallel wiring of the piezoelectric layers of material lying between the electrode layers is possible, which allows an optimum operation of the piezoelectric actuator 1 .
[0041] The present invention thus creates a piezoelectric actuator and a method for producing the same, with, because of the separation points or stress-relieving recesses obtained during the sintering in the areas of the recesses 4 or 4 ′, electrically non-conductive areas as well as mechanically stress-relieving zones to prevent mechanical stresses are obtained. The inventive method guarantees that no new technology need be introduced and no new production facilities are necessary. Furthermore because of the use of the silver paste and the silver-palladium paste, no new connections or elements are introduced into the chemical system of the piezoelectric actuator, which could lead to unknown effects. Furthermore silver is cost effective compared to palladium, so that additional material costs are insignificant. The additional screen printing process to print on the silver paste is simple and cost effective to undertake compared to additional production steps with previous measures for avoiding cracks.
[0042] Although the present invention has been described here on the basis of preferred exemplary embodiments, it is not restricted to them but is able to be modified in numerous ways.
[0043] For example, instead of the silver-palladium paste, another metallization paste containing noble metals can be used with a low diffusion capability of the electrically-conductive particles during sintering of the stack. Furthermore another paste containing noble metals or another suitable stress-relieving material with a very high diffusion capability of the electrically-conductive particles during sintering of the stack can also be used instead of the silver paste as stress-relieving material. Generally any stress-relieving material which guarantees a non-conductive area in the recess zones and prevents an adhesion between adjacent layers is suitable for forming a stress-relieving recess or a stress-relieving area.
[0044] Furthermore the recess zones, instead of being provided at diagonally opposite corner areas, can also be provided within the layer surface, for example such that drilled holes run in the longitudinal direction of the piezoelectric actuator through the individual recess pattern in each case. This advantageously enables contacting to be laid from the outside of the piezoelectric actuator to the inside. For example suitable contacting means are inserted into the at least two holes so that once again each second electrode layer is electrically contacted and the intermediate layers are not contacted because of the recess zones provided. In addition adjacent layers in these recess zones do not adhere to each other because of the stress-relieving recesses. | A method for producing a piezoelectric actuator has the following steps: providing a plurality of piezoelectric material layers ( 2 ) which can be assembled into a stack; applying electrode layers ( 3 ) each having a recess ( 4, 4′ ) to the plurality of piezoelectric material layers, such that an alternating sequence of piezoelectric material layers and electrode layers is formed in the stack, wherein electrode layers with a recess ( 4 ) in a first recess zone and electrode layers with a recess ( 4′ ) in a second recess zone which differs from the first recess zone are alternatingly formed in the stack; and providing a stress-relieving material ( 5 ) in the first and second recesses, the stress-relieving material exhibiting electrically insulating properties after the stack is sintered, and preventing the individual material layers from adhering to one another. | 8 |
FIELD OF THE INVENTION
[0001] The invention relates to a patient support apparatus with a removable foot section. In one of its aspects, the invention relates to a removable foot section provided with a positive locking mechanism provided with a convenient handle for use in attachment and removal of the removable foot section by an operator.
BACKGROUND OF THE INVENTION
[0002] A patient support apparatus with a removable foot section, also known in the field as a birthing bed, provides full support for a patient, namely an expectant mother in labor, until she is ready to give birth. Rather than move the mother to another bed that gives the doctor better access, the birthing bed is provided with a removable foot section. This removable foot section must be capable of ready detachment, but just as importantly must be positively secured to the main bed and incapable of inadvertent detachment. It would further be advantageous to provide a removable foot section with an operating mechanism that does not extend beyond the normal profile of the bed, and is intuitive to the operator in its method of operation.
SUMMARY OF THE INVENTION
[0003] A patient support apparatus includes a patient support having a first patient support deck, a removable section having a second patient support deck, the removable section being configured for movement to a first position wherein the removable section is coupled to the patient support, a second position wherein the removable section is adjacent to but spaced from the first position and a third position spaced apart from the patient support. A handle support mechanism is mounted on one of the patient support and the removable section. A handle is movably mounted on the handle support mechanism and is supported thereby for movement between a first handle position and a second handle position. The handle support mechanism is configured to facilitate movement of the handle from the first handle position toward the second handle position only when the removable section is oriented at and between the first and second positions.
[0004] In a further embodiment of the invention, a patient support apparatus comprises a patient support including a first patient support deck, a removable section having a second patient support deck, the removable section being configured for movement to a first position wherein the removable section is coupled to the patient support, a second position wherein the removable section is adjacent to but spaced from the first position and a third position spaced apart from the patient support. A sensing mechanism is configured for sensing a presence of the removable section at and between the first and second positions thereof. A latch recess mechanism is mounted on the patient support and configured to be engaged by the sensing mechanism in response to the removable section being moved from the third position toward the first position, the latch recess mechanism including at least one recess. A latch mechanism is mounted on the removable section and includes a latch member configured to move into the at least one recess only in response to the sensing mechanism sensing the presence of the removable section at the first position.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] The purposes of the invention will be apparent to persons acquainted with apparatus of this general type upon reading the following specification and inspecting the accompanying drawings, in which:
[0006] FIG. 1 is a perspective view of a patient support apparatus with a removable foot section according to the invention;
[0007] FIG. 2 is a bottom perspective view of the patient support apparatus of FIG. 1 ;
[0008] FIG. 3 is a partial cut-away view of the patient support apparatus of FIG. 2 ;
[0009] FIG. 4 is a partial cut-away view of the removable foot section moving toward an attached position on the patient support apparatus;
[0010] FIG. 5 is a partial cut-away view of the removable foot section of FIGS. 1-4 with a sensing link activated by a patient support apparatus latch mount;
[0011] FIG. 6A is a bottom perspective view of the removable foot section of FIGS. 1-5 with a secondary locking mechanism disengaged;
[0012] FIG. 6B is an enlarged view of a handle pivot mechanism according to FIG. 6A ;
[0013] FIG. 7 is a partial cut-away perspective view of the removable foot section of FIG. 6 ;
[0014] FIG. 8 is a partial cut-away view of the removable foot section of FIGS. 1-7 with the locking mechanism partially engaged;
[0015] FIG. 9 is a partial cut-away perspective view of the removable foot section of FIGS. 1-8 with the locking mechanism fully engaged;
[0016] FIG. 10 is a cross-sectional view of a locking mechanism according to a second embodiment of the invention;
[0017] FIGS. 11-16 are cross-sectional views of the locking mechanism of FIG. 10 sequentially illustrating the locking action of the mechanism;
[0018] FIG. 17 is a bottom perspective view of a removable foot section according to a further embodiment of the invention;
[0019] FIG. 18 is an enlarged cut-away view of a portion of the removable foot section of FIG. 17 ;
[0020] FIG. 19 is a partial cut-away view according to FIG. 18 with a latch mechanism partially engaged;
[0021] FIG. 20 is a partial cut-away view according to FIGS. 18-19 with the latch mechanism engaged;
[0022] FIGS. 21-24 are perspective views of alternative handle configurations of the removable foot section of FIGS. 1-9 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0023] Certain terminology will be used in the following description for convenience in reference only and will not be limiting. The words “up”, “down”, “right” and left” will designate directions in the drawings to which reference is made. The words “in” and “out” will refer to directions toward and away from, respectively, the geometric center of the device and designated parts thereof. The words “proximal” and “distal” will refer to the orientation of an element with respect to the patient support apparatus. Such terminology will include derivatives and words of similar import.
[0024] Referring to FIG. 1 , a patient support apparatus with a removable foot section 100 is illustrated. The patient support apparatus 100 includes a main bed 110 and a removable foot section 150 .
[0025] The main bed 110 includes a support base 115 to which is mounted a main bed patient support deck 116 . The support deck 116 supports a main bed pad or mattress 112 having an upper surface 113 . The main bed 110 further includes an anterior or perineal edge face 114 adapted for receiving the removable foot section 150 .
[0026] A pair of mounting brackets 118 ( FIGS. 1-3 ) is positioned distally from the anterior face 114 and is configured for mounting a pair of latch mounts 120 for securing the removable foot section 150 proximate the anterior face 114 of main bed 110 . The mounting brackets 118 can be configured as disclosed in commonly owned, co-pending U.S. patent application Ser. No. ______, entitled “MATERNITY BED FOOT SUPPORT AND ABDUCTION ASSEMBLY,” filed _ (Atty. Docket: S*M C-299), incorporated herein by reference. The removable foot section 150 can be supported by a pair of abductors as illustrated therein, for alignment of the removable foot section 150 with the latch mounts 120 . In the alternative, the removable foot section 150 and the abductors can be arranged to deliberately preclude support of the removable foot section 150 by the abductors, in order to force an operator to deliberately align the removable foot section 150 with the latch mounts 120 , and to avoid inadvertent placement of the removable foot section 150 adjacent the main bed 110 in a non-engaged condition.
[0027] Each latch mount 120 has a generally upwardly opening “C” shape and includes a distal or nose portion 128 incorporating an upwardly and inwardly directed catch 122 , a flattened central portion 126 and a raised proximal portion including an inwardly directed recess 124 . Referring further to FIG. 2 , each latch mount 120 includes a mounting base 132 for mounting the latch mount 120 to the mounting bracket 118 . Each latch mount 120 further incorporates a pair of parallel opposing side channels 130 forming a narrowed center section or neck 129 for facilitating insertion of the latch mount 120 into the removable foot section 150 as will be further described below.
[0028] Referring to FIGS. 1 and 2 , the removable foot section 150 includes a proximal end 162 and a concave distal end 164 . The removable foot section 150 further includes a pair of tubular side rails 156 , a proximal cross rail 160 and an arcuate distal cross rail 158 . The tubular side rails 156 include a proximal end 157 . A foot section patient support deck 154 is mounted to the rails 156 , 158 , 160 . The patient support deck 154 is further configured for supporting a foot section pad 152 having an upper surface 153 . When the removable foot section 150 is attached to the main bed 110 , the upper surface 153 of the foot section 150 will be contiguous with the upper surface 113 of the main bed pad 112 .
[0029] The removable foot section 150 further includes a brace 166 attached to and depending from the proximal cross rail 160 and the foot section patient support deck 154 . The brace 166 is configured to support the removable foot section 150 in a vertical orientation on a floor surface when the foot section 150 is removed from the main bed 110 . The removable foot section 150 is configured to stand, in the vertical orientation, on the brace 166 and the proximal end 157 of the side rails 156 .
[0030] At the proximal end 157 of the side rails 156 , each side rail 156 includes a mount-receiving slot 168 with a chamfered mouth 170 . A sleeve 224 is secured within the side rail 156 over the mount-receiving slot 168 by a fastener 225 . The mount-receiving slots 168 are adapted for receiving the latch mounts 120 in such a manner that the neck 129 of each latch mount 120 , formed by the side channels 130 , aligns with the respective mount-receiving slot 168 of the side rails 156 . The sleeve 224 is positioned within the side rail 156 for alignment with the recess 124 of the latch mount 120 as the latch mount 120 enters the side rail 156 . The chamfered mouth 170 of each mount-receiving slot 168 aids the operator in guiding the latch mounts 120 into the mount-receiving slots 168 .
[0031] The removable foot section 150 further includes a locking mechanism 180 for releasably locking the removable foot section 150 to the main bed 110 . As seen in FIGS. 1-2 , the locking mechanism 180 presents an operator with a main U-shaped handle 182 and a U-shaped release lever 184 pivotally associated with the main U-shaped handle 182 . The handle 182 and release lever 184 are inverted “U”s straddling the removable foot section 150 in the form of an arch. Each depending leg of the handle 182 and release lever 184 terminate within a handle pivot assembly 186 . The handle pivot assembly 186 is pivotally mounted to a locking mechanism cam housing 188 depending from each side rail 156 . Each cam housing 188 is U-shaped, with each upstanding leg or wall of the cam housing 188 connecting to the tubular side rail 156 so that the cam housing 188 hangs directly beneath the side rail 156 .
[0032] Referring briefly to FIGS. 6A-6B , the cover of the handle pivot assembly 186 has been removed to reveal that the release lever 184 is pivotally attached to the main handle 182 by a pivot pin 244 , and includes a distal portion 246 extending beyond the fulcrum formed by the pivot pin 244 . The main handle 182 is fixedly mounted to a double-D-shaped cam pin 232 which rotatably mounts the main handle 182 to the cam housing 188 . A spring-urged plate 239 having a central elongate slot 237 is slidably mounted on the cam pin 232 . The plate 239 includes a locking lug 240 extending inwardly toward the cam housing 188 , and adapted, under the urging of a spring 241 , for engaging one of a number of notches 242 , 243 formed in the wall of cam housing 188 . In FIGS. 6A-6B , the release lever 184 has been rotated about the pivot pin 244 so that the distal portion 246 of the release lever 184 has countered the urging of the spring 241 on the plate 239 , forcing the locking lug 240 out of the notch 242 . In FIGS. 3-4 , the locking lug 240 is urged by the spring 241 into the notch 242 .
[0033] Referring now to FIG. 3 , a partial cut-away view of the removable foot section 150 , the internal components of the locking mechanism 180 within one side rail 156 are illustrated. The handle pivot assembly 186 , the outer wall of the cam housing 188 and the side rail 156 have been removed to reveal the internal components. The configuration of the locking mechanism 180 of each side rail 156 is the same. In the following description, the components and function of only one side rail 156 will be described, but it is to be understood that the components and function apply to both side rails 156 . It is to be recognized that some portions of the handle pivot assembly 186 will need to be a mirror image of the other for attachment to the outside of the respective side rail 156 .
[0034] The locking mechanism 180 within the tubular side rail 156 includes a locking cam 230 , a carriage assembly 210 connected to the locking cam 230 by an elongate locking mechanism linkage 200 , and an elongate sensing link 190 .
[0035] The locking cam 230 is eccentrically mounted on the double-D-shaped cam pin 232 and is rotatably connected to the cam housing 188 . The locking cam 230 includes a lever arm 231 and a distally extending flat portion 234 .
[0036] The locking mechanism linkage 200 is pivotally connected at its distal end to the lever arm 231 of the locking cam 230 by a pivot pin 202 , and is pivotally connected at its proximal end to the carriage assembly 210 by a pivot pin 204 .
[0037] The carriage 210 is slidably received within the tubular side rail 156 . The carriage 210 carries a U-shaped pivotal locking arm 212 , the bight portion of the “U” forming a locking hook 214 . The legs 212 A (see FIG. 3 ) of the “U” straddle the carriage 210 and are pivotally supported on the carriage 210 by a pivot pin 211 . The locking hook 214 is forced upward as a locking pin 220 , fixed to the respective side rail 156 , pivots the locking arm 212 about the pivot pin 211 by pressing against a distal portion of the locking arm 212 .
[0038] The elongate sensing link 190 is slidably carried within the tubular side rail 156 and includes a proximal end 192 and a distal end 194 . The sensing link 190 is spring-biased in a proximal direction by a spring 195 connecting the sensing link 190 to the carriage assembly 210 , forcing the proximal end 192 of the sensing link 190 toward the proximal end 157 of the side rail 156 . As shown in FIGS. 3-4 , the distal end 194 of sensing link 190 is urged by the bias of the spring 195 against the locking cam 230 and under the flat portion 234 .
Operation
[0039] As shown in FIGS. 1-5 , the main handle 182 is shown locked in an upright “carry” position. The arcuate distal end of the removable foot section 150 can be balanced against the operator's midsection while the operator carries the removable foot section 150 by the upright, locked main handle 182 . It will be intuitive to the operator that the carry handle must be moved from the upright “carry” position to a stowed position so as to not interfere with the use of the patient support apparatus.
[0040] Referring to FIGS. 1-4 , the main handle 182 is prevented from rotating from its upright “carry” position by two mechanisms, the locking cam 230 and the spring-urged plate 239 (see FIGS. 6A and 6B ). The handle 182 , the locking cam 230 , and the plate 239 are all rotatably fixed on the double-D-shaped cam pin 232 . The locking cam 230 is prevented from rotating due to the positioning of the distal end 194 of the sensing link 190 under the flat portion 234 of the locking cam 230 . The plate 239 is urged by the spring 241 so that locking lug 240 is received in the notch 242 . In order to rotate the handle 182 , both of these locking mechanisms must be released.
[0041] To releasably attach the removable foot section 150 to the main bed 110 , the removable foot section 150 must begin at a position removed from the anterior face 114 , with the upper surface 153 of the foot section pad 152 substantially co-planar with the upper surface 113 of the main bed pad 112 . This will align the bottom face of the side rails 156 and therefore the mount receiving slots 168 with the side channels 130 of the latch mounts 120 . The side rails 156 must also be aligned laterally with the latch mounts 120 .
[0042] As the removable foot section 150 is moved toward the main bed 110 , the nose end 128 of each latch mount 120 will enter a respective side rail 156 such that the side channels 130 will be received in the mount receiving slots 168 . Since the nose section 128 of the latch mount 120 is lower than the raised proximal portion of each latch mount 120 , the nose section 128 will clear the sleeve 224 mounted within each side rail 156 (see FIG. 4 ). As each latch mount 120 enters each side rail 156 , the nose section 128 will contact the proximal end 192 of each sensing link 190 .
[0043] Further movement of the foot section 150 toward the main bed 110 will cause the nose section 128 to force the sensing link 190 against the bias of the spring 195 . As the sensing link 190 is displaced against the bias of spring 195 , the distal portion 194 of the sensing link 190 is forced clear of the flat portion 234 of the cam 230 . With the distal portion 194 of the sensing link 190 displaced, as shown in FIGS. 5-9 , the flat 234 can now clear the distal portion 194 of sensing link 190 so that the cam 230 can rotate in a counter clockwise direction.
[0044] Before the handle 182 can be rotated, however, the secondary locking mechanism comprising the lug 240 within the notch 242 must be disengaged. In a natural and intuitive operation, aided by color-coding or instructional wording on the release lever 184 , the operator will squeeze together the release lever 184 and the main handle 182 . The release lever 184 is thereby rotated about the pivot pins 244 , causing the distal portion 246 of the release lever 184 to shift the plate 239 against the urging of spring 241 and extract the locking lug 240 from the notch 242 (see FIGS. 6A-6B ). With the locking lug 240 out of the notch 242 , the double-D-shaped cam pin 232 , the locking cam 230 , the plate 239 , and the main handle 182 are free to rotate together relative to the cam housing 188 . With the removable foot section 150 still supported in the engaged position against the main bed by the operator's midsection, the operator can then draw the main handle 182 distally about the cam pin 232 , thereby engaging the locking mechanism 180 for securing the removable foot section 150 to the main bed 110 .
[0045] With particular reference to FIG. 8 , as the cam pin 232 rotates with the main handle 182 , the lever arm 231 of the cam 230 draws the locking mechanism linkage 200 toward the distal end of removable foot section 150 , drawing the carriage assembly 210 with it. As the carriage assembly 210 traverses distally with respect to the locking pin 220 , the locking hook 214 is urged by sliding contact with the locking pin 220 into the central portion 126 of the latch mount 120 and then is drawn distally against the catch 122 . Further rotation of the cam 230 will result in the foot section 150 being drawn in toward the anterior face 114 of the main bed until the sleeve 224 is received in the recess 124 of the latch mount 120 .
[0046] The cam housing 188 includes a stop 236 positioned such that the flat portion 234 of the cam 230 reaches the stop 236 as the sleeve 224 is fully received in the recess 124 of the latch mount 120 . This coincides with the main handle 182 having rotated approximately 90 degrees so that it is substantially co-planar with the side rails 156 , and no longer interferes with the use of the bed. Upon release of the main handle 182 and the release lever 184 by the operator, the spring 241 acting on the plate 239 will urge the locking lug 240 inwardly to engage the notch 243 in the cam housing 188 . The notch 243 is positioned on the cam housing 188 to correspond to the main handle 182 being in the horizontal position.
[0047] The removable foot section 150 is thereby positively mounted to the main bed 110 until an operator proactively grasps the main handle 182 and the release lever 184 and moves the release lever 184 toward the main handle 182 , thence causing the locking lug 240 to be extracted from the notch 243 . The operator then rotates the main handle 182 in a clockwise rotation, reversing the above-described sequence to disengage the locking mechanism 180 . When main handle 182 reaches the upright position and the release lever 184 is released by the operator, the locking lugs 240 will enter the notches 242 under the urging of the springs 241 to lock the handle 182 in the upright position. The removable foot section 150 can thereafter be lifted away from the main bed 110 . The concave distal end 164 of the removable foot section 150 is configured for resting against the operator's midsection while the operator lifts the removable foot section 150 by the main handle 182 . With the concave distal end 164 resting against the operator's midsection, the center of mass of the removable foot section 150 is advantageously drawn closer to the operator, rendering the removable foot section 150 easier to lift and transport.
Second Embodiment of FIGS. 10 - 16
[0048] Referring now to FIGS. 10-16 , a further embodiment of a locking mechanism 300 for a removable foot section for a patient support apparatus is illustrated. The mechanism 300 includes a plate-like latch mount 310 configured for mounting to a main bed comparable to the main bed 110 described above. The latch mount 310 includes a sensing link receiver 312 , a latch receiver/recess 314 and a catch 316 .
[0049] The removable foot section includes a rail 320 that is substantially rectangular in cross-section. A cross pin 322 is fixedly mounted near the proximal end of the rail 320 . A locking arm 330 is pivotally mounted to the rail 320 by a spring/locking arm pivot 332 . The locking arm 330 is pivotally linked to a spring arm 334 also pivoting about the spring/locking arm pivot 332 and biased in a counter clockwise direction (as shown in FIG. 10 ) by a spring 328 .
[0050] The locking arm 330 includes a locking arm face 335 and is prevented from rotating through the contact of the locking arm face 335 with a sensing link nose 344 . The sensing link nose 344 is part of a sensing link 340 slidably mounted within the rail 320 . The sensing link 340 includes a longitudinal slot 352 for facilitating a relative movement to the spring/locking arm pivot 332 of the locking arm 330 . The sensing link 340 further incorporates a proximal slot/recess 342 for clearing the cross pin 322 of the cross rail 320 .
[0051] Referring sequentially to FIGS. 10-15 , as the foot section is moved or pushed by the attendant proximally toward the main bed, the latch mount 310 enters the proximal end of rail 320 through appropriately provided slots as in the embodiment described above. The first positive engagement occurs between the sensing link receiver 312 of the latch mount 310 and the sensing link nose 344 of the sensing link 340 .
[0052] As the sensing link nose 344 contacts and is displaced distally by the latch mount 310 as shown in FIGS. 12-13 , the sensing link 340 is displaced distally with respect to the rail 320 as the rail 320 continues its movement toward engagement with the latch mount 310 . As the cross pin 322 becomes fully engaged with the latch receiver/recess 314 of the latch mount 310 , the sensing link nose 344 is pushed by the latch mount 310 past the locking arm face 335 of the locking arm 330 . When the sensing link nose 344 has cleared the locking arm face 335 , the locking arm 330 is biased counter clockwise by the spring 328 , forcing the locking hook 336 mounted to the locking arm 330 into the catch 316 of the latch mount 310 . The foot section is thereby locked with the main bed in a positive manner.
[0053] Referring to FIG. 16 , a release mechanism is disclosed whereby a release handle 350 is slidably mounted to the side rail 320 . The release handle 350 includes two angled slots 358 , 360 configured to ride on laterally extending pins 362 , 364 secured to the frame 320 , so that as the release handle 350 is depressed (or lifted), the angled slots 358 , 360 will cause the release handle 350 to be drawn upward and to the right. A link arm 354 is pivotally mounted to the sensing link 340 by a pivot pin 348 . The link arm 354 includes a second pin 356 configured to engage the release handle 350 , and is supported by the laterally extending pin 362 . When the sensing link 340 is in the non-engaged position, i.e. fully extended to the left, the link arm 354 is also drawn to the left. With the link arm 354 drawn to the left, the second pin 356 is drawn into a longitudinal slot 353 formed in the release handle 350 . Therefore, if the release handle is depressed when the sensing link 340 is not engaged by the latch mount 310 , the second pin 356 can slide freely in the slot 353 and the sensing link 340 is not affected. With the sensing link 340 displaced to the right by engagement with the latch mount 310 , the link arm 354 is also displaced to the right, as shown in FIG. 16 . This shifts the second pin 356 out of the slot 353 and into a position to be engaged by a recess wall 355 formed on the release handle 350 . As the release handle 350 is depressed, the second pin is engaged by the recess wall 355 , causing sensing link 340 to be further displaced to the right. As sensing link 340 is displaced distally, a locking arm retracting pin 349 mounted on the sensing link 340 will bear against a locking arm retractor 338 , acting against the bias of the spring 328 and causing the locking arm 330 to rotate clockwise as shown in FIG. 16 . With locking hook 336 withdrawn from the catch 316 , the foot section can be withdrawn distally from the main bed. As the foot section is withdrawn, the handle 350 can be released so that the sensing link nose 344 can engage the locking arm face 335 under the urging of the spring 328 .
Third Embodiment of FIGS. 17 - 20
[0054] FIGS. 17-20 disclose a further embodiment of the patient support apparatus with a removable foot section 450 according to the invention. A pair of latch mounts 420 are provided, mounted to a main bed as described above in the first embodiment. The latch mounts 420 comprise an upwardly directed “C” shape, having an inwardly directed proximal recess 424 and an inwardly directed distal catch 422 . The latch mounts 420 further include an arcuate nose portion 428 .
[0055] The removable foot section 450 includes a foot section patient support deck 454 supported by a pair of longitudinal side rails 456 and cross rails 458 , 460 , and a pad 452 supported by the support deck 454 . The side rails 456 each include a proximal slot 468 having a mouth 470 for receiving each of the latch mounts 420 , as in the first embodiment
[0056] The removable foot section 450 further includes an attachment and locking mechanism 480 . The locking mechanism 480 includes a handle 482 in the form of an inverted “U”. Each of the legs of the handle 482 are connected to a cam bracket 530 . Each cam bracket 530 is pivotally mounted to one of the side rails 456 by a pivot pin 532 . The cam bracket 530 includes an internal cam plate 534 pivotally connecting the cam bracket 530 to a connecting link 500 by a pivot pin 502 , an external mounting plate 536 for mounting the handle 482 and a back plate 538 serving as a rotation stop of the cam bracket 530 with respect to the side rail 456 . Each connecting link 500 is further pivotally connected to a carriage 510 and sensing link 490 . The connecting link 500 is connected to the carriage 510 by a pin 504 passing through a slot (not shown) in the side rail 456 . The slot enables proximal-distal movement of the pin 504 and the carriage 510 within the side rail 456 . The sensing link 490 pivots about the pin 504 .
[0057] FIGS. 18 and 19 are enlarged cut-away views showing the carriage 510 , the sensing link 490 , and a locking arm 512 , which can be of a U-shape straddling the carriage 510 with the bight portion forming a locking hook 514 . The carriage 510 is slidably received in the side rail 456 , and pivotally mounts the locking arm 512 about a pivot pin 506 . The locking arm 512 is held in a raised position by a locking pin 520 after the same fashion as the first embodiment.
[0058] Referring specifically to FIG. 18 , the sensing link 490 includes a catch 496 for receiving the locking pin 520 . In the position shown in FIG. 18 , the catch 496 has received the locking pin 520 therein, which prevents the carriage 510 from moving distally within the side rail 456 . The handle 482 is also thereby prevented from rotating distally about pivot pin 532 .
[0059] Referring to FIG. 19 , the removable foot section 450 has been moved proximally toward the latch mount 420 so that the arcuate nose portion 428 of the latch mount 420 has engaged the leading edge 492 of the sensing link 490 . This causes the sensing link 490 to pivot about the pin 504 , disengaging the catch 496 from the pin 520 . This frees the carriage 510 to slide distally, and therefore frees the cam bracket 530 to be rotated about pivot pin 532 and handle 482 to be rotated distally. Upon rotation of the cam bracket 530 about the pivot pin 532 , the connecting link 500 is drawn distally, and the carriage 510 moves distally.
[0060] As the latch mount 420 is positioned to displace the sensing link 490 , it further aligns the recess 424 with the sleeve 224 , and aligns the locking hook 514 of the locking arm 512 with the catch 422 of the latch mount 420 .
[0061] In much the same fashion as the first embodiment described above, when the handle 482 is rotated counter-clockwise, the link 500 will be pulled distally. As shown in FIG. 20 , the carriage 510 will draw the locking arm 512 to the left and cause the pin 520 to drive the proximal end of the locking arm 512 downward. The locking hook 514 engages the catch 422 while drawing the foot section 450 against the patient support, fully engaging the sleeve 224 in the recess 424 .
[0062] As the handle 482 is rotated distally, the back plate 536 of the cam bracket 530 contacts the bottom of the side rail 456 as the handle 482 reaches a horizontal position. The arrangement is configured such that when the handle 482 is in the horizontal position, the locking mechanism 480 is fully engaged with the sleeve 224 fully seated in the recess 424 and the removable foot section 450 closely drawn against the patient support.
Alternate Embodiments of FIGS. 21 - 24
[0063] Referring now to FIGS. 21-24 , alternative locking mechanism embodiments 1180 , 2180 , 3180 , 4180 are illustrated.
[0064] In FIG. 21 , a removable foot section 1150 is provided with a locking mechanism 1180 . The locking mechanism 1180 is provided on each side rail 156 and includes a main handle 1182 and a release lever 1184 projecting a short distance upwardly from each handle pivot assembly 186 .
[0065] In FIG. 22 , a removable foot section 2150 is provided with a locking mechanism 2180 on each side rail 156 . The locking mechanism 2180 comprises a main handle 2182 and a release lever 2184 . The main handle 2182 includes an inwardly turned portion 2183 , and the release lever includes an inwardly turned portion 2185 , each inwardly turned portion 2183 , 2185 extending over the upper surface 153 of the foot section pad 152 . The inwardly turned portions 2183 , 2185 lack a continuous bight portion therebetween.
[0066] In FIG. 23 , a removable foot section 3150 is provided with a locking mechanism 3180 on each side rail 156 having main handles 3182 and release levers 3184 pivotally connected in a handle pivot assembly 3186 . The release lever 3184 is positioned proximally of the main handle 3182 for grasping by an operator. The main handles 3182 and the release levers 3184 curve proximally.
[0067] In FIG. 24 , a removable foot section 4150 is provided with a locking mechanism 4180 comprising a main handle 4182 . The main handle 4182 is pivotally or slidably mounted to the removable foot section between the side rails 156 , and configured to release the locking mechanism 4180 .
[0068] Although a particular preferred embodiment of the invention has been disclosed in detail for illustrative purposes, it will be recognized the variations or modifications of the disclosed apparatus, including the rearrangement of parts, lie within the scope of the present invention. | A patient support apparatus includes a patient support having a first patient support deck, a removable section having a second patient support deck, the removable section being configured for movement to a first position wherein the removable section is coupled to the patient support, a second position wherein the removable section is adjacent to but spaced from the first position and a third position spaced apart from the patient support. A handle support mechanism is mounted on one of the patient support and the removable section. A handle is movably mounted on the handle support mechanism and is supported thereby for movement between a first handle position and a second handle position. The handle support mechanism is configured to facilitate movement of the handle from the first handle position toward the second handle position only when the removable section is oriented at and between the first and second positions. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a color image forming apparatus such as a color printer, color copying machine, color facsimile apparatus, or the like, which has a plurality of image forming portions using a plurality of laser scanner optical systems, drives a laser element by a pulse-width modulation signal, and draws an image by light emitted from the laser element.
2. Description of Related Art
FIG. 12 is a schematic block diagram showing the arrangement of a portion associated with laser pulse width adjustment of a conventional color image forming apparatus. The image forming apparatus reproduces tones of an image by pulse-width modulation.
An image data generating portion 101 draws an image on, e.g., a page memory on the basis of data supplied from an external apparatus (e.g., a host computer) to generate raster data in a print process, and to generate image data for adjustment upon adjusting the pulse width.
A pulse width modulating portion 102 pulse-width modulates 8-bit image data (density value) supplied from the image data generating portion 101 to generate a pulse-width modulation signal (pulse-width modulated signal). Note that the pulse width modulating portion 102 has a minimum pulse width setting portion 103 for setting a minimum pulse width of the pulse-width modulation signal generated by the pulse width modulating portion 102 , and a maximum pulse width setting portion 104 for setting a maximum pulse width of the pulse-width modulation signal.
A laser driver 106 drives a laser diode 107 a of a light-emitting portion 107 on the basis of the pulse-width modulation signal supplied from the pulse width modulating portion 102 , thereby forming an electrostatic latent image on a photosensitive drum (not shown). Note that the light-emitting portion 107 has a photodiode 107 b used to detect the light amount of a beam emitted by the laser diode 107 a as an electrical signal. A current generated by the photodiode 107 b increases nearly in proportion to an increase in light amount of light emitted by the laser diode 107 a . Since the photodiode 107 b has a low response speed, when the laser diode 107 a repeats emission and putting out of light on the basis of the pulse-width modulation signal, the photodiode 107 b generates a current according to the ratio between the light emitting period of time and the light putting out period of time. That is, the light emitting period of time increases with increasing value of image data, and a current generated by the photodiode 107 b increases. Conversely, the light emitting period of time decreases with decreasing value of image data, and a current generated by the photodiode 107 b decreases.
The current generated by the photodiode 107 b is converted by a resistor 108 into a voltage value, which is buffered and amplified by an OP amplifier 109 . The amplified value is then supplied to a controlling portion 105 . The controlling portion 105 has a CPU 105 a and an A/D converter 105 b . The A/D converter 105 b converts an analog signal (light amount detection signal) input from the OP amplifier 109 into a digital signal. Based on that digital signal, the CPU 105 a adjusts the setting values of the minimum and maximum pulse width setting portions 103 and 104 so that the light amount of a beam emitted by the laser diode 107 a matches a target value.
FIG. 13 shows the relationship between the pulse width of a drive signal (pulse-width modulation signal) of the laser diode 107 a , and the light amount of a beam emitted by the laser diode 107 a . As the characteristics of the laser diode, the pulse width of a beam emitted by the laser diode becomes smaller than that of the drive signal. This is because laser oscillation occurs when the quantity of carriers inside the laser diode has exceeded a predetermined value due to a current supplied to the laser diode, and a certain time period is required until the quantity of carriers inside the laser diode exceeds the predetermined value. Such delay of laser emission is called an emission delay of laser, and is a cause of the pulse width reduction of the laser beam.
In order to obtain an emission waveform with an appropriate pulse width, the pulse width of the drive signal of the laser diode 107 a must be set to be larger than that of a desired emission waveform. This adjustment is called pulse width adjustment. For this reason, when the laser diode 107 a is driven based on 8-bit image data (i.e., 00(hex) to FF(hex)), the pulse width output from the pulse width modulating portion 102 is saturated at a value smaller than FF(hex). On the other hand, the light amount of light emitted by the laser diode 107 a increases abruptly and is saturated while the pulse of the pulse-width modulation signal reaches saturation.
In the aforementioned arrangement example, a method of inputting image data 00 (hex), and adjusting the setting value of the minimum pulse width setting portion 103 based on the light amount detection value corresponding to that data is available. However, in this case, since the minimum pulse width is adjusted by detecting a very small light amount, it is difficult to stably detect a light amount, and it is also difficult to appropriately adjust the minimum pulse width. In the above arrangement example, since the light amount has already been saturated in image data less than FF (hex), linearity of the light amount is impaired. On the other hand, a method of inputting image data FF (hex), and adjusting the setting value of the maximum pulse width setting portion 104 based on the light amount detection value corresponding to that data is available. However, in this case, since the light amount has already been saturated in image data less than FF (hex), linearity of the light amount is impaired.
To solve this problem, Japanese Patent Application Laid-Open No. 10-272801 proposed a method of pulse-width modulating, for example, image data 10(hex) near the minimum value 00(hex) of the image data to drive a light-emitting element, adjusting the minimum pulse width based on the light amount, pulse-width modulating, for example, image data F0(hex) near the maximum value FF(hex) of the image data to drive the light-emitting element, and adjusting the maximum pulse width based on the light amount.
In an electrophotographic color image forming apparatus, various methods of sequentially transferring different color images onto a recording medium retained on a conveying belt or onto an intermediate transfer belt by providing a plurality of image forming portions to attain a high-speed process have been proposed.
However, in the case of the conventional arrangement mentioned above, the following problem is posed. When an image forming apparatus has a plurality of image forming portions (e.g., four image forming portions), and has only one A/D converter for detecting the light amount, analog signals (light amount detection signals) of respective colors must be input to the A/D converter while switching them using a multiplexer. For this reason, light amount detection requires a time corresponding to the number of image forming portions, resulting in that it is time-consuming to adjust the laser pulse width.
On the other hand, when the image forming apparatus has A/D converters in correspondence with the number of image forming portions, the time required to detect the light amounts is the same as that of an image forming apparatus having only one image forming portion. However, the cost increases due to a plurality of A/D converters.
SUMMARY OF THE INVENTION
The present invention has been made in consideration of the above situation, and has as its object to provide a color image forming apparatus which can shorten the time required to adjust the laser pulse width with low cost.
It is an object of the present invention to provide an image forming apparatus comprising:
a plurality of emitting means for emitting light beams;
a plurality of scanning means for respectively scanning the light beams emitted by the plurality of emitting means;
first controlling means for controlling phases of the plurality of scanning means to have a specific phase relationship in an image forming mode; and
second controlling means for controlling the plurality of scanning means in an adjustment mode so that the phases of the plurality of scanning means have a specific phase relationship different from the specific phase relationship in the image forming mode.
It is another object of the present invention to provide an image forming apparatus comprising:
a plurality of emitting means for emitting light beams;
a plurality of scanning means for respectively scanning the light beams emitted by the plurality of emitting means;
modulating means for modulating the light beams in accordance with an image signal;
detecting means for detecting light amounts of the light beams; and
single A/D converting means for sequentially converting analog data indicating the light amounts of the light beams detected by the detecting means into digital data.
It is still another object of the present invention to provide a method of controlling an image forming apparatus, which comprises a plurality of image forming portions for scanning light beams by scanning means, the method comprising:
the first step of controlling the plurality of scanning means so that phases of the plurality of scanning means have a specific phase relationship;
the step of adjusting an image forming condition of the image forming apparatus in an adjustment mode;
the second step of controlling the plurality of scanning means so that the phases of the plurality of scanning means have a specific phase relationship different from the specific phase relationship in the first step; and
the step of forming an image in an image forming mode.
It is still another object of the present invention to provide a method of controlling an image forming apparatus, which comprises a plurality of image forming portions for scanning light beams by scanning means, the method comprising:
the step of modulating the light beams in accordance with an image signal;
the step of detecting light amounts of the light beams; and
the step of sequentially converting analog data indicating the detected light amounts of the light beams into digital data using a single A/D converter.
Other objects, arrangements, and effects of the present invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an explanatory view for explaining the overall arrangement of a color image forming apparatus according to the first embodiment of the present invention;
FIG. 2 is a schematic perspective view of a laser scanner optical system used in the first embodiment;
FIG. 3 is a block diagram for explaining a method of preventing color misregister or misregistration less than one line in the conveying direction;
FIG. 4 is a schematic block diagram showing the arrangement of a laser pulse width adjusting portion in the first embodiment;
FIG. 5 is a flowchart showing the sequence of a pulse width adjustment process;
FIG. 6 is a timing chart showing the timings of BD signals in the pulse width adjustment process in the first embodiment;
FIG. 7 is a flowchart showing the sequence of scanner phase control and laser pulse width adjustment in the first embodiment;
FIG. 8 is a schematic perspective view of a 2-beam scanner optical system used in the second embodiment;
FIG. 9 is a schematic block diagram showing the arrangement of a laser pulse width adjusting portion in the second embodiment;
FIG. 10 is a timing chart showing the timings of BD signals in a laser pulse width adjustment of the second embodiment;
FIG. 11 is a timing chart showing the timings of BD signals in a laser pulse width adjustment of the third embodiment;
FIG. 12 is a schematic block diagram showing the arrangement of a portion associated with a laser pulse width adjustment in a conventional image forming apparatus; and
FIG. 13 is a graph showing the relationship between the pulse width of a drive signal (pulse-width modulation signal) of a laser and the light amount of a beam emitted by the laser.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Preferred embodiments of the present invention will be described in detail hereinafter by way of embodiments of a color image forming apparatus. Note that the present invention is not limited to the form of an apparatus but may be implemented in the form of a method using the descriptions of embodiments.
First Embodiment
In the first embodiment, an arrangement which can complete laser light amount detection of respective image forming portions in a one-line period (1-BD period) in a color image forming apparatus having four image forming portions will be explained.
FIG. 1 is a view for explaining the overall arrangement of a “color image forming apparatus” according to the first embodiment. The embodiment is a color image forming apparatus having image forming portions of four colors, i.e., yellow (Y), magenta (M), cyan (C), and black (K). Referring to FIG. 1 , photosensitive drums 1 (suffices k/c/m/y of reference numerals indicate components for K/C/M/Y) are used to form electrostatic latent images. Laser scanners 2 form electrostatic latent images on the photosensitive drums 1 by exposure in accordance with an image signal. An endless conveying belt 3 conveys a sheet to the image forming portions of respective colors sequentially, and also serves as a transfer belt. A drive roller 4 is driven by a motor (not shown) via a drive means including gears and the like so as to drive the conveying belt 3 . A driven roller 5 is rotated by the movement of the conveying belt 3 , and gives a predetermined tension to the conveying belt 3 .
The operation of the embodiment will be explained below. When data to be printed is sent from, e.g., a host computer to a printer, and the printer is ready to print upon completion of image formation according to a formula of the printer, a sheet is fed from a sheet cassette, and reaches the conveying belt 3 , which conveys the sheet to the image forming portions of respective colors in turn. In synchronism with the sheet convey timing of the conveying belt 3 , an image signal of each color is supplied to the corresponding laser scanner 2 to form an electrostatic latent image on the corresponding photosensitive drum 1 . The latent image is developed with toner by a developing device (not shown) to form a toner image, which is transferred onto the sheet by a transfer portion (not shown). In FIG. 1 , images are formed in turn in the order of Y, M, C, and K. After that, the sheet is separated from the conveying belt, and the toner images are fixed on the sheet by a fixing device (not shown). The sheet is then delivered outside the apparatus.
The scanner optical system of each image forming portion will be explained below. FIG. 2 is a schematic perspective view of the scanner optical system. A laser beam emitted by a laser beam source 11 is collimated by a collimator lens 12 , and is then scanned by a polygonal mirror 13 . The scanning speed of the scanned beam is corrected by an f-? lens 14 , and the beam finally forms a latent image corresponding to an image signal on the photosensitive drum 1 . An image clock is synchronized (to be referred to as “BD-synchronized” hereinafter) with a horizontal sync signal (not shown; to be referred to as a BD signal hereinafter) output from a position detection sensor 16 (to be referred to as a BD sensor hereinafter) for detecting the image signal write timing on the photosensitive drum 1 . After the image clock is BD-synchronized, it is delayed for a predetermined period of time, thus starting an image signal writing process.
Since this arrangement includes a plurality of laser scanner optical systems, positional deviations (color misregister) in the conveying direction may occur in an image due to positional deviations of the respective image forming portions in the conveying direction. Correction for each line can be made by an image process. Correction less than one line is attained by controlling the rotation phase of a scanner motor.
FIG. 3 is a block diagram for explaining the method of preventing color misregister less than one line in the conveying direction. A rotation reference signal generation circuit 200 generates rotation reference signals 201 Y, 201 M, 201 C, and 201 K independent for respective colors Y, M, C, and K in accordance with a measurement result from a color misregister measurement means (not shown).
The rotation reference signals 201 Y, 201 M, 201 C, and 201 K have equal cycle periods, and their phases are controlled to have a specific relationship so as to prevent color misregister less than one line upon image formation.
PLL controlling portions 202 Y, 202 M, 202 C, and 202 K independent for respective colors yellow, magenta, cyan, and black respectively compare the phases of the rotation reference signals 201 Y, 201 M, 201 C, and 201 K with those of detect results (BD signals) 203 Y, 203 M, 203 C, and 203 K of motor rotational position detecting means, and controls to remove their phase differences. Note that the motor rotational position detecting means are the aforementioned BD sensors, and BD signals as their detection results are also used to detect the image signal write timings on the corresponding photosensitive drums.
Outputs 204 Y, 204 M, 204 C, and 204 K from the PLL controlling portions 202 Y, 202 M, 202 C, and 202 K are input to motor drivers 205 Y, 205 M, 205 C, and 205 K to accelerate/decelerate motors 206 Y, 206 M, 206 C, and 206 K.
According to the aforementioned arrangement, the phase relationship among the rotation reference signals 201 Y, 201 M, 201 C, and 201 K is determined to remove color misregister less than one line in the conveying direction, and the scanner motors are controlled based on the phase relationship, thus removing color misregister less than one line in the conveying direction. The phases of the rotation reference signals 201 Y, 201 M, 201 C, and 201 K can be determined using a color misregister detecting sensor (not shown) or based on a user's instruction. Note that color misregister not less than one line in the conveying direction can be removed by controlling the image write timing for each line.
The operation of a pulse width modulating portion will be explained below.
FIG. 4 is a schematic block diagram showing the arrangement of a laser pulse width adjusting portion. In this arrangement, since there are four image forming portions for Y, M, C, and K, four image data generating portions are arranged. In the following description, the image forming portion Y will be explained. The same applies to the remaining image forming portions X, C, and K.
An image data generating portion Y plots an image on, e.g., a page memory on the basis of data supplied from an external apparatus (e.g., a host computer) to generate raster data in a print process, and to generate image data for adjustment upon adjustment of the pulse width.
A pulse width modulating portion Y pulse-width modulates 8-bit image data (density value) supplied from the image data generating portion Y to generate a pulse-width modulation signal (pulse-width modulated signal). Note that the pulse width modulating portion Y has a minimum pulse width setting portion (not shown) for setting a minimum pulse width of the pulse-width modulation signal, and a maximum pulse width setting portion (not shown) for setting a maximum pulse width of the pulse-width modulation signal generated by the pulse width modulating portion Y.
A laser driver Y drives a laser Y on the basis of the pulse-width modulation signal supplied from the pulse width modulating portion Y, thereby forming an electrostatic latent image on a photosensitive drum (not shown). A current generated by a photodiode PDY, which detects the light amount of a beam emitted by the laser Y as an electrical signal, increases nearly in proportion to an increase in the light amount of the beam emitted by the laser Y. Since the photodiode PDY has a low operation speed, when the laser Y repeats emission and putting out of light, the photodiode PDY generates a current according to the ratio between the light emitting period of time and the light putting out period of time. That is, the light emitting period of time increases and a current generated by the photodiode PDY increases with increasing value of image data. Conversely, the light emitting period of time decreases and a current generated by the photodiode PDY decreases with decreasing value of image data.
The current generated by the photodiode PDY is converted by an internal resistor of the laser driver Y into a voltage value, which is buffered and amplified by an OP amplifier Y. The amplified value is then supplied to a CPU. Note that the CPU incorporates one A/D converter. The CPU has four A/D inputs, and a signal to be input to the A/D converter is selected by a switching device in the CPU. The A/D converter converts an analog signal (light amount detection signal) input from the OP amplifier Y into a digital signal. A/D conversion in the A/D converter starts in response to each of A/D trigger signals ADTRGY, ADTRGM, ADTRGC, and ADTRGK input to the CPU. Each A/D trigger signal is generated by generating a positive edge a predetermined period of time after the trailing edge of the BD signal of the corresponding image forming portion, and defines a timing so that A/D conversion is made at nearly the center of an image region.
Based on this digital signal, the CPU adjusts the setting values of the minimum and maximum pulse width setting portions so that the light amount of a beam emitted by the laser diode Y matches a target value.
As has been explained in the paragraphs of “Description of Related Art”, since the laser diode suffers emission delay, the pulse width of the laser beam is reduced. In order to obtain an emission waveform with an appropriate pulse width, the pulse width of the drive signal of the laser diode 107 a must be set to be larger than that of a desired emission waveform. This adjustment is called pulse width adjustment. For this reason, when the laser diode 107 a is driven based on 8-bit image data (i.e., 00(hex) to FF(hex)), the pulse width output from the pulse width modulating portion Y is saturated at a value smaller than FF(hex). On the other hand, the amount of light emitted by the laser diode 107 a increases abruptly and is saturated while the pulse of the pulse-width modulation signal reaches saturation.
In the above arrangement example, image data (e.g., 10(hex)) which is near 00(hex) and has a small light amount is input, and the setting value of the minimum pulse width setting portion 103 is adjusted based on the detection value of the light amount corresponding to that image data. Also, image data (e.g., F0(hex)) which is near FF(hex) and has a large light amount is input, and the setting value of the maximum pulse width setting portion 104 is adjusted based on the detection value of the light amount corresponding to that image data.
FIG. 5 is a flowchart showing the sequence of a pulse width adjustment process based on the program stored in the CPU. In the process shown in the flowchart, image data of 10(hex) and image data of F0(hex) are used as image data for pulse width adjustment. The image data 10(hex) is determined so that the photodiode can stably measure the amount of light emitted by the laser diode based on that image data. On the other hand, the image data F0(hex) is determined to fall within a non-saturation range of the amount of light emitted by the laser diode.
In step 101 (S 101 in FIG. 5 ; the same applies to the following description), the image data generating portion supplies image data with a density value 10(hex) to the pulse width modulating portion, and the laser diode is driven by a pulse-width modulation signal corresponding to this image data.
In step 102 , the amount of light emitted by the laser Y which has been driven based on the image data with the density value 10(hex) is converted into digital data by the A/D converter, and the digital data is stored in an A register in the CPU.
In step 103 , a pre-set target value (a target value of the amount of light to be emitted by the laser diode in correspondence with image data with the density value 10(hex)) is compared with the value (measured light amount) stored in the A register. If the two values do not match (it is considered that they match if their difference falls within a predetermined allowable range), the setting value (minimum pulse width, i.e., the pulse width when the density value=00(hex)) of the minimum pulse width setting portion is adjusted in step 104 so that the amount of light emitted by the laser Y matches the target value, and the flow returns to step 102 .
On the other hand, if the target value matches the value (measured light amount) stored in the A register, the flow advances to step 105 . In step 105 , the image data generating portion supplies image data with a density value F0(hex) to the pulse width modulating portion, and the laser Y is driven by a pulse-width modulation signal corresponding to that image data.
In step 106 , the amount of light emitted by the laser Y, which has been driven based on the image data with the density value F0(hex), is converted into digital data by the A/D converter, and the digital data is stored in a B register in the CPU. In step 107 , a pre-set target value (a target value of the amount of light to be emitted by the laser diode Y in correspondence with image data with the density value F0(hex)) is compared with the value (measured light amount) stored in the B register.
If the two values do not match (it is considered that they match if their difference falls within a predetermined allowable range), the setting value (maximum pulse width, i.e., the pulse width when the density value=FF(hex)) of the maximum pulse width setting portion is adjusted in step 108 so that the amount of light emitted by the laser Y matches the target value, and the flow returns to step 106 .
On the other hand, if the target value matches the value (measured light amount) stored in the B register, the series of processes end.
An arrangement that can complete laser pulse width adjustment within a short period of time using the scanner phase control will be explained below.
FIG. 6 shows scanner phases upon laser pulse width adjustment in the first embodiment. Note that the scanner phases are indicated by BD signals. Signals /BD_Y, /BD_M, /BD_C, and /BD_K shown in FIG. 6 are BD signals of negative logic obtained by the BD sensors for Y, M, C, and K, and are controlled by the PLL controlling portions 202 in FIG. 3 to have constant cycle periods. The phases of the BD signals of the respective scanners are set to have 90° phase differences in turn in the order of Y, M, C, and K. That is, 360°÷(the number of laser scanners)=90°.
Signals ADTRGY, ADTRGM, ADTRGC, and ADTRGK shown in FIG. 6 are generated a predetermined period of time after the negative edges of the signals /BD_Y, /BD_M, /BD_C, and /BD_K, respectively, and A/D conversion is made if they are H. The predetermined period of time is determined so that A/D conversion is made at a specific timing (e.g., at the center of an image region). When the switching device selects the OP amplifier Y, ADTRGY is selected as an A/D conversion timing signal, and A/D conversion is made when ADTRGY=H. Likewise, upon selection of OP amplifiers M, C, and K, ADTRGM, ADTRGC, and ADTRGK are respectively selected as A/D conversion timing signals. Assume that the A/D converter has a speed, which is high enough to complete A/D conversion within a ¼ BD period as well as switching of the switching device.
FIG. 7 shows the sequence of the scanner motor phase control for laser pulse width adjustment. If laser pulse width correction starts, the present phases of the scanner motors of the respective image forming portions are recorded in a memory in step 201 . As described above, the scanner phases of the respective image forming portions are set to have a specific phase relationship that can prevent color misregister upon image formation, and these setting values are recorded. In step 202 , the scanner phases of the respective image forming portions are adjusted to those for laser pulse width adjustment shown in FIG. 6 (so that the BD signals have 90 ? phase differences in turn in the order of Y, M, C, and K). In step 203 , pulse width adjustment is executed. The pulse width adjustment method is as has been described above. Finally, in step 204 the scanner phase is restored to the setting values recorded in step 201 .
As described above, according to the embodiment, since the light amount detection signals are fetched using one A/D converter, an increase in cost can be prevented. Also, since the light amounts of the Y, M, C, and K image forming portions can be measured within one BD period, pulse width adjustment can be done within a short period of time.
Second Embodiment
In the second embodiment, an arrangement which can complete laser amount detection of respective image forming portions within two BD periods in a color image forming apparatus which has four image forming portions each having two lasers will be explained.
An image forming apparatus using laser scanner optical systems often simultaneously scans a plurality of lines using a plurality of beams to attain high-speed image formation.
FIG. 8 is a schematic perspective view of a multi-beam, in particular, a 2-beam, scanner optical system. A laser beam source 81 incorporates two lasers. A plurality of beams 87 a and 87 b emitted by the laser beam source 81 are collimated by a collimator lens 82 , and are scanned by a polygonal mirror 83 . The scanning speeds of the scanned beams 87 a and 87 b are corrected by an f-θ lens 84 , and these beams finally form a latent image corresponding to an image signal on a photosensitive drum 85 .
FIG. 9 is a schematic block diagram of a laser pulse width adjusting portion in the embodiment. The arrangement is substantially the same as that in FIG. 4 , except that each image forming portion has two each pulse width modulating portions and lasers. The difference from the first embodiment will be explained below in association with an image forming portion Y. The same applies to other image forming portions.
An image data generating portion Y generates image data based on data supplied from an external apparatus in a print process, and generates image data for adjustment upon pulse width adjustment.
Pulse width modulating portions Y 1 and Y 2 pulse-width modulate image data (density value) supplied from the image data generating portion Y to generate pulse-width modulation signals. The pulse width modulating portion Y 1 generates a pulse-width modulation signal for a laser Y 1 , and the pulse width modulating portion Y 2 generates a pulse-width modulation signal for a laser Y 2 .
A laser driver Y drives the laser Y 1 on the basis of the pulse-width modulation signal supplied from the pulse width modulating portion Y 1 , thus forming an electrostatic latent image on the photosensitive drum. Likewise, the laser driver Y drives the laser Y 2 on the basis of the pulse-width modulation signal supplied from the pulse width modulating portion Y 2 , thus forming an electrostatic latent image on the photosensitive drum.
A photodiode PDY detects the sum of amounts of beams emitted by the lasers Y 1 and Y 2 as a signal, and generates a current corresponding to the sum of light amounts.
Pulse width adjustment is done in the following sequence. In order to make pulse width adjustment of the laser Y 1 , adjustment is done in the sequence shown in FIG. 5 in the same manner as in the first embodiment, while the laser Y 2 does not emit light. In order to make pulse width adjustment of the laser Y 2 , adjustment is done in the sequence shown in FIG. 5 in the same manner as in the first embodiment, while the laser Y 1 does not emit light. At this time, when the lasers Y 1 and Y 2 emit light alternately, the laser pulse width adjustment processes of the lasers Yl and Y 2 can be done in parallel.
FIG. 10 shows the scanner phases upon laser pulse width adjustment in the embodiment, i.e., the phases of BD signals. Signals /BD_Y, /BD_M, /BD_C, and /BD_K shown in FIG. 10 are BD signals of negative logic obtained by BD sensors of Y, M, C, and K, and are controlled by the PLL controlling portions 202 in FIG. 3 to have constant cycle periods. Since beams emitted by the two lasers enter one BD sensor, as shown in FIG. 8 , the BD signal goes active (LOW) twice per one cycle period.
Each of signals ADTRGY, ADTRGM, ADTRGC, and ADTRGK shown in FIG. 10 is generated a predetermined period of time after the first one of two negative edges of each of the signals /BD_Y, /BD_M, /BD_C, and /BD_K. The predetermined period of time is determined so that A/D conversion is made near the center of an image region. The operations of the A/D converter in response to the signals ADTRGY, ADTRGM, ADTRGC, and ADTRGK are the same as those in the first embodiment.
Signals of light emission of laser Y 1 , light emission of laser Y 2 , light emission of laser M 1 , light emission of laser M 2 , light emission of laser C 1 , light emission of laser C 2 , light emission of laser K 1 , and light emission of laser K 2 shown in FIG. 10 respectively indicate light emission timings for laser pulse width adjustment of lasers Y 1 , Y 2 , M 1 , M 2 , C 1 , C 2 , K 1 , and K 2 . When the signal is HIGH, each laser emits light; when the signal is LOW, each does not emit light.
The scanner motor control sequence for laser pulse width adjustment is shown in FIG. 7 as in the first embodiment. Upon executing pulse width adjustment in step 203 , the light amounts of the two lasers are alternately measured in each image forming portion, as described above.
The order of light amount measurements of the respective lasers will be explained below with reference to FIG. 10 . In the image forming portion Y, the signal ADTRGY goes H near the center of an image region. At this time, since the laser Y 1 emits light for laser pulse width adjustment, and the laser Y 2 is OFF, only the light amount of the laser Y 1 can be measured. After that, the light amounts of the lasers M 1 , C 1 , K 1 , Y 2 , M 2 , C 2 , and K 2 are measured in turn.
As can be seen from the timings shown in FIG. 10 , these light amount measurements are completed within two BD cycle periods. By repeating these light amount measurements a plurality of times, laser pulse width adjustment is done.
With the above arrangement, since the light amounts of the image forming portions Y, M, C, and K can be measured within two BD cycle periods, pulse width adjustment can be done within a short period of time in the apparatus with the 2-beam laser arrangement.
Third Embodiment
In the third embodiment, an arrangement which can complete detection of light amount of lasers of respective image forming portions within two BD cycle periods in a color image forming apparatus having four image forming portions will be explained.
In the third embodiment, the basic arrangement is the same as that in the first embodiment, but the conversion speed of the A/D converter is low and A/D conversion cannot be completed within a ¼ BD cycle period, unlike in the first embodiment.
FIG. 11 shows the scanner phases upon laser pulse width adjustment in the third embodiment. Signals /BD_Y, /BD_M, /BD_C, and /BD_K shown in FIG. 11 are BD signals of negative logic obtained by BD sensors for Y, M, C, and K as in the first embodiment. The signals /BD_Y and /BD_C are in phase, and the signals /BD_M and /BD_K are in phase. The signals /BD_Y and /BD_M are out of phase by 180°.
Signals ADTRGY, ADTRGM, ADTRGC, and ADTRGK shown in FIG. 11 are generated a predetermined period of time after the negative edges of the signals /BD_Y, /BD_M, /BD_C, and /BD_K, respectively. However, unlike in the first embodiment, the signals ADTRGY, ADTRGM, ADTRGC, and ADTRGK are generated once per two negative edges of the BD signals, so that the signals ADTRGY, ADTRGM, ADTRGC, and ADTRGK are out of phase by 180° in the order named. That is, 360°÷(the number of laser scanners)×2=180°. Depending on the processing speed of the A/D converter and the like, an appropriate frequency given by 360° (the number of laser scanners)×n (where n is a natural number) can be selected.
The order of light amount measurements of the respective lasers will be explained below with reference to FIG. 11 . After the signal /BD_Y goes LOW, the signal ADTRGY goes HIGH near the center of the first image region to make A/D conversion. Next, the signal ADTRGM goes HIGH after a ½ BD cycle period to make A/D conversion. After that, light amount measurements of the lasers M and K are done every ½ BD cycle periods. With the above operations, the light amounts of the lasers of the four image forming portions can be measured within two BD cycle periods. By repeating this process a plurality of times, laser pulse width adjustment can be done in the sequence shown in FIG. 7 as in the first embodiment.
In this way, the light amounts of the lasers of the Y, M, C, and K image forming portions can be measured within two BD cycle periods, and pulse width measurements can be done within a short period of time even when the A/D converter has a low conversion speed.
In the embodiments described above, an arrangement having a plurality of photosensitive drums has been explained. Also, the present invention can be practiced in the same manner as described above in a color image forming apparatus which makes multiple development on a single photosensitive drum using a plurality of laser scanner optical system.
As described above, in an image forming apparatus with a plurality of laser scanners, laser pulse width correction can be done within a short period of time using a low-cost arrangement.
Some preferred embodiments of the present invention have been explained. However, the present invention is not limited to such specific embodiments, and various modifications and applications may be made within the scope of the claims. | A color image forming apparatus and laser pulse width adjustment method can shorten the time required for laser pulse width adjustment with low cost. In a color image forming apparatus in which a plurality of laser scanners scan and expose a plurality of photosensitive drums with laser beams pulse-width modulated according to image data, the scanner phases of the laser scanners in which no color misregistration occurs are recorded, the phases of the laser scanners are changed to a specific phase relationship for laser pulse width adjustment, laser pulse width adjustment is executed, and the phases of the laser scanners are then restored to the recorded scanner phases in which no color misregistration occurs. | 1 |
TECHNICAL FIELD
[0001] The present invention relates to an ion diffusing apparatus that includes an ion generator and a fan, more particularly, to an ion diffusing apparatus that facilitates replacement of the ion generator and is able to keep a stable ion supplying capability; and to an ion generating cartridge.
BACKGROUND ART
[0002] In recent years, a function is discovered, in which by means of positive ions and negative ions generated into the air, germs floating in the air are killed and viruses are inactivated; and products such as an air cleaner and the like to which this technology is applied are attracting attention from people.
[0003] Besides, as an ion generating portion that generates the positive ions and the negative ions, a plasma discharge type is known, in which electric discharge is performed between a needle-shape positive discharge electrode and a plate-shape induction electrode, and between a needle-shape negative discharge electrode and the plate-shape induction electrode; thus, the positive ions are generated from the positive discharge electrode and the negative ions are generated from the negative discharge electrode. The plasma discharge is performed at the needle-shape positive and negative discharge electrodes, so that the air and vapors are ionized and the positive ions and negative ions are generated. As the positive ion, H + (H 2 O) m (m is a natural number), in which a plurality of water molecules are bonding to a circumference of a hydrogen ion, is chiefly generated; and as the negative ion, O 2 − (H 2 O) n (n is a natural number), in which a plurality of water molecules are bonding to a circumference of an oxygen ion, is chiefly generated.
[0004] If the above H + (H 2 O) m and O 2 − (H 2 O) n bond to a surface of a floating germ, chemical reaction occurs, thereby generating hydrogen peroxide (H 2 O 2 ) or hydroxyl radical (.OH) that are active species. Because of this, the floating germ is destroyed by the decomposition action of the active species. It is said that in this way, it is possible to kill or inactivate the germ-relatives in the air such as bacteria, viruses and the like to remove them.
[0005] As described above, by supplying H + (H 2 O) m and O 2 − (H 2 O) n into a room at the same time, it becomes possible to kill and inactivate the germ-relatives contained in the air of the room. However, in a case where impurities or dust collects on the needle-shape discharge electrode that is the ion generating portion, the ion generation effect deteriorates, so that it becomes impossible to supply a desired amount of generated ions.
[0006] To kill and inactivate the germ-relatives in the air to remove them, because an amount of the positive ions and of the negative ions are needed, more than a predetermined amount of the positive ions and of the negative ions per unit volume becomes necessary, so that as for an ion generating portion whose ion generation effect deteriorates, it is preferable to eliminate the cause of the deterioration or repair the ion generating portion.
[0007] Because of this, to facilitate demounting, cleaning and maintenance of an air processing unit and an ion diffusing apparatus, an air processing unit and an ion diffusing apparatus which are removably mounted on a base portion for mounting the air processing unit and the ion diffusing apparatus are already proposed (e.g., see patent document 1).
CITATION LIST
Patent Literature
[0008] PLT1: Japanese patent No. 4114602B2
SUMMARY OF INVENTION
Technical Problem
[0009] By supplying the positive ions and negative ions into a room, it is possible to kill and inactivate germ-relatives floating in the air to clean the room; however, the germ-relatives are killed, inactivated and removed by using the positive ions and negative ions at the same time, it is preferable the amounts of positive ions and negative ions remaining in the air are equal to or more than a predetermined amount; and the amounts are approximately equal to each other.
[0010] Moreover, according to a method in which when diffusing, by means of a fan and the like, the positive and negative ions that are generated from an ion generating portion of an ion generating apparatus, the ions are diffused by means of an air flow generated by simply sending a wind to the ion generating portion, the positive and negative ions collide with each other to be neutralized, so that it is hard to evenly disperse the ions into the air without the neutralization. Besides, according to a method in which the positive and negative ions are separately generated and carried by means of a sending wind, it is possible to carry the ions to a distant place by preventing the ions from colliding with each other; however, the amount of the dispersed positive and negative ions does not become even, so that it is impossible to achieve desired killing and inactivating effects.
[0011] Because of this, an ion diffusion apparatus is desired, in which the positive and negative ions are evenly generated; the remaining amount per unit volume of the ions sent out into a room is increased, and the percentages of the respective positive- and negative-ion remaining amounts are substantially the same as each other. Moreover, a structure which facilitates the maintenance of the ion generating portion is desired.
[0012] In light of the above problems, it is an object of the present invention to provide an ion diffusing apparatus and an ion generating cartridge which are so structured as to allow an ion generating apparatus to be freely mounted and demounted; able to generate evenly the positive ions and the negative ions while sending out them far into a room.
Solution to Problem
[0013] To achieve the above object, an ion diffusing apparatus according to the present invention that diffuses positive ions and negative ions generated by plasma discharge into a room, the ion diffusing apparatus comprises:
[0014] a fan that generates an air flow for exhaling air, which is inhaled from an inlet, from an outlet into the room via a flow passage that is formed in the apparatus;
[0015] an ion generating apparatus that includes a positive ion generating portion and a negative ion generating portion; and supplies positive ions generated from the positive ion generating portion and negative ions generated from the negative ion generating portion into the air flowing through the flow passage; and
[0016] an ion generating apparatus housing portion that houses the ion generating apparatus in such a posture that an ion generating surface of the ion generating apparatus is exposed with the ion generating surface matched with a flow surface of one surface which forms a wall surface of the flow passage; wherein
[0017] the ion generating apparatus is able to be inserted and pulled out from an insertion opening that is formed through a side of the outlet, and freely mountable and demountable into and from the ion generating apparatus housing portion.
[0018] According to this structure, the ion generating apparatus, whose ion generating surface is exposed in such a posture that the ion generating surface matches with the flow surface of the flow passage, and which is freely mountable and demountable into and from the ion generating apparatus housing portion, is disposed, so that it is possible to obtain the ion diffusing apparatus, in which the maintenance is easy and it becomes possible to exhale the ions emitted from the ion generating surface by means of a streamline flow along the flow surface, and to send out the positive ions and the negative ions far into the room by curbing the collision between the positive ions and the negative ions and preventing them from being neutralized.
[0019] Besides, in the ion diffusing apparatus having the above structure according to the present invention, the one surface is composed of a lower lateral wind-direction plate that forms a lower wall surface of the flow passage. According to this structure, it is possible to obtain the ion diffusing apparatus that sends out the positive and negative ions in a horizontal direction of the room along a flow surface of the lower lateral wind-direction plate; and it becomes possible to exhale the positive and negative ions into the room region where people are living.
[0020] Besides, the ion diffusing apparatus having the above structure according to the present invention is formed as an ion generating cartridge that includes an ion generator that has the positive ion generating portion and the negative ion generating portion, the ion generating cartridge houses the ion generator and unitarily includes:
[0021] an insertion guide portion;
[0022] a position guide portion; and
[0023] a lever member that engages with an engagement portion disposed in the ion generating apparatus housing portion of the apparatus main body to fix the position of the cartridge;
wherein a structure is employed, in which the ion generating apparatus is inserted from the insertion opening into the ion generating apparatus housing portion via the insertion guide portion and the position guide portion; and fixes the ion generating apparatus in such a posture that the ion generating surface is matched with the flow passage via the position guide portion and the lever member.
[0025] According to this structure, the ion generating apparatus is formed as the cartridge type that unitarily includes: the insertion guide portion; the position guide portion; and the lever member, so that the ion generating apparatus which facilitates the maintenance is obtained. Besides, it is possible to fix the ion generating surface while exposing the ion generating surface, which has the curved surface matching with the flow surface of the lower wind-direction plate, via a cut-away portion formed through the lower wind-direction plate.
[0026] Besides, in the ion diffusing apparatus having the above structure according to the present invention, the ion generating apparatus includes the ion generator in which the positive ion generating portion and the negative ion generating portion are spaced apart in a direction that intersects an air flow direction; and a vertical wind-direction plate, which partitions the flow passage into flow passages for the respective positive ion generating portion and negative ion generating portion, is disposed in the flow passage. According to this structure, it becomes possible to separately carry the positive ions and the negative ions, so that it is possible to curb further effectively the collision between both ions of the positive and negative ions; and to obtain the ion diffusing apparatus that is able to send out the ions far into the room without neutralizing the ions.
[0027] Besides, in the ion diffusing apparatus having the above structure according to the present invention, an intermediate lateral wind-direction plate, which partitions a flow passage between the lower lateral wind-direction plate and an upper lateral wind-direction plate that forms an upper wall surface of the flow passage, is disposed to partition the flow passage that extends from the fan to the outlet into multi-stage streamline flow passages;
[0028] a plurality of the ion generating apparatuses are disposed in parallel with each other to form a continuous-length ion generating surface that has alternately the positive ion generating portion and the negative ion generating portion in a line at a predetermined pitch along the flow passage of the lower lateral wind-direction plate; and
[0029] the vertical wind-direction plate, which partitions the flow passage into the flow passages for the respective positive ion generating portion and negative ion generating portion, is so disposed as to penetrate the multi-stage streamline flow passages.
[0030] According to this structure, each ion generating apparatus, which includes the positive ion generating portion and the negative ion generating potion, becomes freely mountable and demountable, so that not only the maintenance becomes easy but also sophisticated maintenance becomes possible. Besides, the flow passage is disposed for every electrode, so that it becomes possible to send out the positive and negative ions far into the room by curbing the neutralization of the positive and negative ions.
[0031] Besides, in the ion diffusing apparatus having the above structure according to the present invention, the vertical wind-direction plate is angled in such a way that the ions are exhaled at a wide angle with respect to a width direction in which the ion generating apparatuses are disposed in parallel with each other. According to this structure, the flow passage disposed for every ion generating portion is widened in a wide angle, so that it is possible to disperse the ions into a predetermined area of the room.
[0032] Besides, in the ion diffusing apparatus having the above structure according to the present invention, the ion generating cartridge includes:
[0033] an input-output connector portion that connects with an external electrode to perform input and output;
[0034] a control board that controls driving of the positive ion generating portion and the negative ion generating portion by means of electric power obtained via the input-output connector portion; and
[0035] an ion sensor that detects the ions generated by the ion generating portion.
[0036] According to this structure, it is possible to obtain the ion generating apparatus formed as the ion generating cartridge which is able to be connected to an external power supply or an external terminal via the input-output connector portion and is easy to check for normal operation via the ion sensor that is disposed in advance.
[0037] Besides, in the ion diffusing apparatus having the above structure according to the present invention, the ion sensor is a negative ion detection sensor that is disposed on a downwind side with respect to the negative ion generating portion of the ion generating cartridge. According to this structure, the amount of negative ions generated from the negative ion generating portion during an operation time of the ion diffusing apparatus is detected, so that it is possible to detect whether the ion generating cartridge is normally operating or not and how much the ion generating cartridge deteriorates.
[0038] Besides, in the ion diffusing apparatus having the above structure according to the present invention, a positive ion generating electrode of the positive ion generating portion of the ion generator and a negative ion generating electrode of the negative ion generating portion of the ion generator are each of a double electrode type in which two generating electrodes are disposed close to each other. According to this structure, it is possible to increase the amount of generated ions.
[0039] Besides, in the ion diffusing apparatus having the above structure according to the present invention, the ion generating cartridge is formed as a two-stage ion generating type in which the ion generators are disposed in two stages and in parallel with each other; and positive and negative polarities of the positive ion generating electrode and the negative ion generating electrode of the respective ion generators are disposed at reversed positions. According to this structure, it becomes possible to exhale the positive ions and the negative ions into the same flow passage by driving the two-stage ion generators at the same time; and to alternately exhale the positive ions and the negative ions into the same flow passage by alternately driving the two-stage ion generators.
[0040] Besides, in the ion diffusing apparatus having the above structure according to the present invention, the ion generators in the respective stages of the ion generating cartridge of the two-stage ion generating type are alternately operated. According to this structure, it is possible to prolong double the life of the ion generating cartridge.
[0041] Besides, in the ion diffusing apparatus having the above structure according to the present invention, an open-close cover for closing and opening the insertion opening is disposed; the ion generating cartridge is inserted until a predetermined position; when the lever member is rotated to a fix lock position where a hook portion of the lever member is engaged with the engagement portion of the main body, the closing of the open-close cover is possible; and in a state in which the lever member is not rotated to the fix lock position, the lever member hinders the open-close cover from being closed. According to this structure, in a case where the ion generating cartridge is not disposed at a correct position of the ion generating apparatus housing portion and not locked, it is impossible to close the open-close cover, so that it is possible to easily detect the faulty disposition of the ion generating cartridge.
[0042] Besides, in the ion diffusing apparatus having the above structure according to the present invention, a drive start-stop operation portion is disposed on the apparatus main body; the operation portion is provided with: a drive mode set portion that sets a rotation speed of the fan; a cartridge disposition time set portion that sets disposition of a new ion generating cartridge; a timer set portion; a replacement recommendation indication portion that recommends cartridge replacement after elapse of a predetermined time after the new cartridge is disposed and the operation is started; and a level indication portion that indicates whether the amount of the ions generated by each ion generating cartridge is equal to, over or under a predetermined amount. According to this structure, as for an ion generating cartridge whose service life is decided in advance, it is possible to notify that a replacement time is coming by performing indication for recommending the replacement after elapse of a time from the disposition of the new cartridge. Besides, if the amount of generated ions is equal to or under the predetermined amount, the information is indicated, so that it is possible to know the maintenance is necessary.
[0043] Moreover, the ion generating apparatus according to the present invention, which generates the positive ions and negative ions by means of the plasma discharge, is formed as an ion generating cartridge that includes:
[0044] an input-output connector portion that connects with an external electrode and performs input and output of a signal;
[0045] an ion generator in which a positive ion generating electrode and a negative ion generating electrode are disposed;
[0046] an ion sensor that detects ions generated by the ion generator; and
[0047] a control board that controls drive of the ion generator by means of electric power obtained via the input-output connector portion.
[0048] According to this structure, the respective ion generating portions for the positive ions and the negative ions are disposed, so that it becomes easy to handle the ion generating apparatus of the cartridge type that generates the positive and negative ions at the same time. Besides, the ion sensor is disposed, so that it is possible to obtain the ion generating cartridge which is easy to check for normal operation.
[0049] Besides, in the ion generating cartridge having the above structure according to the present invention, the ion sensor is a negative ion detection sensor that detects the negative ions generated from the negative ion generating electrode. According to this structure, when the ion generating electrode portion deteriorates, the amount of the negative ions generated from the negative ion generating electrode also decreases, so that by detecting the amount of the negative ions generated from the negative ion generating electrode during the operation, it is possible to detect whether the ion generating cartridge is normally operating or not and how much the ion generating cartridge deteriorates.
[0050] Besides, the ion generating cartridge having the above structure according to the present invention includes:
[0051] a lever member which has: a handle portion that is held at times of insertion and pulling-out of the cartridge; and a hook member that fixes the cartridge at a predetermined position after the insertion; wherein
[0052] a side portion of a frame body of the cartridge is provided with: a guide protrusion portion, a butt surface and a guide surface that perform a guide function at the time of inserting the cartridge. According to this structure, it is possible to obtain the ion generating cartridge that becomes easily mountable and demountable at the predetermined position of the ion diffusing apparatus via the butt surface, the guide surface that perform the guide function and the lever member that includes the hook member.
[0053] Besides, the ion generating cartridge having the above structure according to the present invention has a rectangular shape when viewing an ion generating surface, from top, on which the positive and negative ion generating portions are disposed;
[0054] the ion generator is formed as a two-stage ion generating type in which positive and negative polarities of the ion generating electrode portions are disposed at reversed positions in two stages and in parallel with each other; and
[0055] the ion generating surface is formed into a curved surface that matches with a flow surface where the ion generating cartridge is disposed.
[0056] According to this structure, the flow surface where the ion generating cartridge is disposed is provided with the rectangular-shape cut-away portion, so that it is possible to obtain the ion generating cartridge which is able to be disposed with the ion generating surface matched with the flow surface. Besides, it becomes possible to send out the positive and negative ions into the partitioned flow passages at the same time and to alternately send out them.
[0057] Besides, in the ion generating cartridge having the above structure according to the present invention, the ion generators in the respective stages of the ion generating cartridge of the two-stage ion generating type are alternately operated. According to this structure, it is possible to obtain the ion generating cartridge which alternately sends out the positive and negative ions into the partitioned flow passages and the life of which becomes double.
Advantageous Effects of Invention
[0058] According to the present invention, the ion generating apparatus is obtained, in which while the ion generating surface is matched with the flow surface of the flow passage that extends from the fan to the outlet, the ion generating apparatus supplies the positive ions and the negative ions into the air flowing through the flow passage, and is freely mountable and demountable into and from the ion generating apparatus housing portion, so that it is possible to obtain the ion diffusing apparatus whose maintenance is easy and which is able to send out the positive ions and the negative ions far into a room by curbing the collision between the positive ions and the negative ions and without neutralizing them. Besides, the ion generating apparatus is formed as the ion generating cartridge that includes: the input-output connector; the ion generators for respectively generating the positive ions and the negative ions; the ion sensor; and the control board, so that it becomes easy to handle the ion generating apparatus of the cartridge type which generates the positive and negative ions at the same time and evenly. Besides, the ion sensor is disposed, so that it is possible to obtain the ion generating cartridge which is easy to check for normal operation.
BRIEF DESCRIPTION OF DRAWINGS
[0059] [ FIG. 1 ] shows an example of an ion diffusing apparatus according to the present invention, of which FIG. 1 ( a ) is a side sectional view; and FIG. 1 ( b ) is a front view.
[0060] [ FIG. 2 ] is a schematic descriptive view showing an insertion procedure of an ion generating cartridge according to the present invention, of which FIG. 2 ( a ) is a side sectional view showing a state in which an insertion is started; FIG. 2 ( b ) is a side sectional view showing a state in which the insertion is being performed; and FIG. 2 ( c ) is a side sectional view showing a state in which the insertion is completed.
[0061] [ FIG. 3 ] is a schematic descriptive view of a lever member of an ion generating cartridge, of which FIG. 3 ( a ) is an enlarged descriptive view showing a fix lock portion; and FIG. 3 ( b ) is a plan view of an entire lever member.
[0062] [ FIG. 4 ] shows an example of an ion generating cartridge according to the present invention, of which FIG. 4 ( a ) is a plan view; and FIG. 4 ( b ) is a side view.
[0063] [ FIG. 5A ] is a schematic descriptive view of a flow passage.
DESCRIPTION OF EMBODIMENTS
[0064] Hereinafter, embodiments of the present invention are described with reference to the drawings. Besides, the same constituent members are indicated by the same reference numbers and detailed description of them is suitably skipped.
[0065] An ion diffusing apparatus according to the present embodiment is an ion diffusing apparatus that includes an ion generating apparatus and a fan, and sends out ions generated by the ion generating apparatus into a room; as shown in FIG. 1 ( a ), an apparatus main body 2 is provided with a fan 3 and an ion generating apparatus 10 that includes an ion generator which has a positive ion generating portion and a negative ion generating portion. Besides, an outlet 4 for sending out the ions generated by the ion generating apparatus 10 to outside is disposed on a front side of the apparatus main body 2 ; and an inlet 5 is disposed on another side (e.g., bottom surface) of the apparatus main body 2 .
[0066] It is also possible to dispose an air filter at the inlet 5 that inhales air; and a stricture is employed, in which the air inhaled from the inlet 5 is sent to the ion generating apparatus 10 that performs plasma discharge via the fan 3 ; and the air and vapors are ionized and sent out from the outlet 4 .
[0067] The ion generating apparatus 10 includes the ion generator that includes a pair of electrodes each of which performs the plasma discharge; as described later, a positive ion generating portion that includes a positive ion generating electrode and a negative ion generating portion that includes a negative ion generating electrode are disposed away from each other by a predetermined distance.
[0068] Besides, a lower lateral wind-direction plate 22 A that serves as a lower wall surface of a flow passage which extends from the fan 3 to the outlet 4 , and an upper lateral wind-direction plate 22 E that serves as an upper wall surface of the flow passage which extends from the fan 3 to the outlet 4 are disposed. And, an ion generating apparatus housing portion, in which the ion generating apparatus 10 is disposed while an ion generating surface where the ion generator is disposed is matched with a flow surface of the lower lateral wind-direction plate 22 A, is formed. Besides, an insertion opening 6 is formed on the outlet side to make it possible to freely mount and demount the ion generating apparatus 10 from the front side of the ion diffusing apparatus 1 . Here, if a structure is employed, in which the ion generating apparatus 10 is formed as a cartridge type and disposed in the ion generating apparatus housing portion that is formed in the apparatus main body, the ion generating apparatus becomes freely mountable and demountable and the replacement becomes easy, which is preferable. Because of this, in the present embodiment, the ion generating apparatus 10 is formed as the cartridge type that unitarily includes: an insertion guide portion; a position guide portion; and a lever member 14 that engages with an engagement portion disposed in the ion generating apparatus housing portion of the apparatus main body to fix the position of the cartridge, so that a structure is obtained, in which the cartridge is freely mountable and demountable in such a posture that the ion generating surface is exposed to the flow surface via the lever member 14 .
[0069] The ion generating apparatus 10 is formed as the cartridge type and freely mountable and demountable in a state in which the ion generating surface is matched with the flow surface that forms the flow passage; accordingly, it is preferable that the ion generating surface, where the positive ion generating portion and the negative ion generating portion are disposed, has a shape that matches with the flow surface. Besides, it is preferable that the positive and negative ion generating portions are disposed away from each other in a direction which intersects a flow direction. According to this structure, it becomes possible to send out the ions emitted from the ion generating surface by means of a streamline flow along the flow surface. Moreover, the positive and negative ion generating portions are disposed in the direction that intersects the flow direction, so that it becomes possible to send out the positive ions and the negative ions far into the room by curbing the collision between the positive ions and the negative ions and by preventing them from being neutralized.
[0070] Because of this, in a case where the flow passage that extends from the fan 3 to the outlet 4 has a bent shape, it is preferable that the ion generating surface of the ion generating apparatus 10 is formed into a curved surface which matches with the flow surface of the lower lateral wind-direction plate 22 A that is bent.
[0071] Besides, the ion generating apparatus 10 of the cartridge type, which unitarily includes: the insertion guide portion; the position guide portion; and the lever member 14 that engages with the engagement portion disposed in the ion generating apparatus housing portion of the main body to fix the position of the cartridge, is inserted from the insertion opening 6 formed through the front surface of the apparatus and disposed, from outside of the flow passage, in such posture that the ion generating surface is exposed to the flow surface, so that the ion generating surface matches with the flow surface and it is possible to supply the ions into the air flowing through the flow passage without disturbing the air flow.
[0072] Because of this, along the streamline flow on the flow surface of the flow passage, it becomes possible to send out the positive and negative ions generated by the positive and negative ion generating portions disposed on the ion generating surface without disturbing the ions. Besides, the ion generating apparatus housing portion is formed under the lower lateral wind-direction plate 22 A that forms the lower wall surface of the flow passage, so that it becomes possible to stably send out the positive and negative ions in a horizontal direction by means of the streamline flow formed on the lower wall surface.
[0073] To partition the flow passage extending from the fan 3 to the outlet 6 into streamline flow passages in a vertical direction, in the present embodiment, as shown in FIG. 1 , between the lower lateral wind-direction plate 22 A and the upper lateral wind-direction plate 22 E, a second lateral wind-direction plate 22 B, a third lateral wind-direction plate 22 C and a fourth lateral wind-direction plate 22 D are disposed as intermediate wind-direction plates; and by disposing these lateral wind-direction plates 22 ( 22 A to 22 E), the flow passage is partitioned into multi-stage streamline flow passages from an inner circumferential surface close to the fan 3 to an outer circumferential surface.
[0074] In the case of the above structure, the ion generating apparatus housing portion is formed in the apparatus main body and under the flow passage along the lower lateral wind-direction plate 22 A, so that it is possible to insert the ion generating apparatus 10 of the cartridge type from the insertion opening 6 formed under the outlet 4 , and freely mount and demount the ion generating apparatus 10 , via an outer side of the lower lateral wind-direction plate 22 A, in such posture that the ion generating surface is exposed to the flow surface.
[0075] Besides, to dispose the ion generating apparatus 10 with the ion generating surface matched with the flow surface of the lateral wind-direction plate 22 , the ion generating surface may be used as part of the flow surface of the lateral wind-direction plate 22 , which is able to be achieved by disposing the ion generating apparatus 10 in parallel with the lateral wind-direction plate 22 ; or by cutting away part of the flow surface of the lateral wind-direction plate 22 and disposing the ion generating apparatus 10 . Accordingly, in the present embodiment, a structure is employed, in which the lower wind-direction plate 22 is provided with a cut-away portion 22 a (see FIG. 2 ( a )) for exposing the ion generating surface; and the ion generating surface of the ion generating apparatus 10 is exposed via the cut-away portion.
[0076] The ion generating apparatus 10 is so structured as to include the pair of the positive ion generating electrode and the negative ion generating electrode each of which performs the plasma discharge; accordingly, to make it possible to evenly send out the positive ions and the negative ions far into the room, it is preferable to carry the generated positive ions and negative ions by means of separate flow passages to prevent the ions from colliding with each other and being neutralized.
[0077] Besides, to mingle the positive ions and the negative ions in the room, the positive and negative ion generating portions may be so disposed as to be successively alternately disposed; by disposing the ion generators that have the pair of positive and negative electrodes in a line at a predetermined pitch, it is possible to alternately dispose the positive ion generating portions and the negative ion generating portions. Besides, the positive and negative ion generating portions are disposed away from each other by the predetermined distance, so that it is possible to curb the collision between the positive and negative ions at a time immediately after the generation of the ions.
[0078] Because of this, as shown in FIG. 1 ( b ), the ion diffusing apparatus 1 is so structured as to have the apparatus main body 2 that is laterally long; and in the inside of the main body 2 , a plurality of the ion generating apparatuses 10 ( 10 A, 10 B, 10 C, 10 D) are disposed. Besides, to send out the ions generated from these ion generating apparatuses, the laterally long fan 3 is used to send out the ions from the laterally long outlet 4 .
[0079] In disposing laterally the plurality of ion generating apparatuses 10 ( 10 A, 10 B, 10 C, 10 D) in parallel with each other, by disposing the ion generating apparatuses 10 that have the positive ion generating portion and the negative ion generating portion in a line and in parallel with each other, it is possible to alternately dispose the positive ion generating portion and the negative ion generating portion. Besides, the positive ion generating portion and the negative ion generating portion are alternately disposed; accordingly, vertical wind-direction plates 21 ( 21 a to 21 j ) for partitioning the flow passage into flow passages for the respective ion generating portions are disposed; and the ions are sent out by means of the respective flow passages.
[0080] Besides, it is possible to angle each of the vertical wind-direction plates to exhale the ions into the room across a wide angle. For example, the angle of a central wind-direction plate 21 d is set at 0°, and the angle is so set as to gradually become wider toward the sides, and the angles of the vertical wind-direction plates 21 a, 21 j at both ends are set at large angles facing outside, so that it is possible to exhale and diffuse the ions into the room across the wide angle.
[0081] For example, as shown in FIG. 5 , the vertical wind-direction plates 21 a to 21 j , which partition the flow passage into the flow passages for the respective positive and negative ions generating portions of the ion generating apparatuses 10 A, 10 B, 10 C and 10 D, are disposed in such a way that the vertical wind-direction plates at the sides are more widely opened, so that it is possible to form the flow passages that exhale the ions across the wide angle.
[0082] According to the above structure, it becomes possible to send out the ions generated by the respective ion generating portions without the collision between the adjacent ions that have different polarities, so that it is possible to evenly send out the ions far into the room. However, by means of a method in which the positive and negative ions are continuously sent out via the same flow passage, it is hard to evenly mingle the positive and negative ions; and a disadvantage that the flow passage is charged with electricity is likely to happen. Because of this, in the present embodiment, ion generators, which are each of a double electrode type that disposes the two generating electrodes, that is, the positive ion generating electrode and the negative ion generating electrode close to each other, are disposed in two stages; and the ion generators are each formed as an ion generating cartridge of a two-stage ion generating type in which the polarities of the ion generating electrodes of the respective ion generators are reversed to each other. In other words, the ion generating apparatuses 10 A, 10 B, 10 C and 10 D are each formed as the ion generating cartridge type.
[0083] For example, in a case where the ion diffusing apparatus 10 having the above ion generating cartridge is operated in a living space of ten tatami mats (about 18 m 2 ), when the two-stage ion generators are alternately driven, it is experimentally confirmed that the average number of ions in the living space is 7,000/cm 3 or more for both of the positive ions and the negative ions. Besides, when the two-stage ion generators are driven at the same time, it is experimentally confirmed that the average number of ions is 50,000/cm 3 or more for both of the positive ions and the negative ions. Because of this, if the ion diffusing apparatus according to the present invention is used, it becomes possible to kill the influenza viruses and the like residing in the room in a short time.
[0084] Conventionally, it is known that the positive ions H + (H 2 O)m (m is an arbitrary integer) and the negative ions O 2 − (H 2 O)n (n is an arbitrary integer) are sent out into the air; and floating germs and the like are killed by the reaction of the ions. However, the ions recombine with each other to disappear, so that even if it is possible to achieve a high concentration in the vicinity of an ion generating element, the longer the distance for which the ions are sent out becomes, the more rapidly the concentration decreases. Accordingly, even if it is possible to achieve an ion concentration of tens of thousands of ions per cm 3 in small-volume spaces such as an experimental apparatus and the like, it is possible to achieve concentrations of 2,000 to 3,000/cm 3 only at best in large spaces such as an actual living space, a working space and the like.
[0085] On the other hand, the inventors have discovered that at a laboratory level, when the ion concentration is 7,000/cm 3 , it is possible to remove 99% of the bird-flu viruses in 10 minutes; and when the ion concentration is 50,000/cm 3 , it is possible to remove 99.9% of the bird-flu viruses in 10 minutes. Both removal rates mean that if it is supposed viruses reside in the air in a concentration of 1,000/cm3, viruses remain in a concentration of 10/cm 3 at the 99% removal rate, and in 1/cm 3 at the 99.9% removal rate. In other words, by increasing the ion concentration from 7,000/cm 3 to 50,000/cm 3 , the remaining viruses become 1/10. From this, it is understood that in a living space where people and the like live and a working space, for prevention of an infectious disease and for environmental cleaning, it is very important not only to send out a high concentration of ions but also to keep the high concentration throughout the spaces.
[0086] Next, the ion generating cartridge having the above structure is described by means on FIG. 4 . This ion generating cartridge is the ion generating apparatus 10 formed as the cartridge type and has the same constituent members, so that the same reference numbers are used to describe the ion generating cartridge 10 . The ion generating cartridge 10 shown in FIG. 4 is of the two-stage ion generating type in which an ion generator 12 A including a positive ion generating portion 13 A of the double electrode type and a negative ion generating portion 13 B of the double electrode type; and an ion generator 12 B including a negative ion generating portion 13 B of the double electrode type and a positive ion generating portion 13 A of the double electrode type are disposed in parallel with each other and in two stages.
[0087] The positive and negative ion generating electrodes each have a needle-shape discharge electrode HD and perform the plasma discharge between a plate-shape induction electrode around them and themselves to generate ions. Besides, if each of the discharge electrodes HD is formed as the double electrode type, the positive ion generating portion 13 A includes two electrodes, that is, positive ion generating electrodes 13 Aa, 13 Ab; and the negative ion generating portion 13 B includes two electrodes, that is, negative ion generating electrodes 13 Ba, 13 Bb, so that each discharge amount becomes double and it is possible to stably generate more than a predetermined amount of ions.
[0088] If a structure is employed to alternately operate the ion generators 12 A, 12 B of the two-stage ion generating type; and if a structure is employed to partition the flow passage by means of the vertical wind-direction plate 21 , a structure is obtained, in which as the ions sent out by an air flow F 1 , the positive ions are sent out during a time the ion generator 12 A operates; and the negative ions are sent out during a time the ion generator 12 B operates.
[0089] Because of this, by setting the operation periods of the ion generator 12 A and the ion generator 12 B at a predetermined time interval, it is possible to intermittently exhale the positive and negative ions into the same air flow at the predetermined time intervals and to mingle both of the positive and negative ions in a predetermined concentration.
[0090] Besides, a structure is obtained, in which as the ions sent out by an air flow F 2 , the ion generator 12 A operates to send out the negative ions; and the ion generator 12 B operates to send out the positive ions. As described above, in the air flow F 1 and the air flow F 2 , the ions having the reverse polarities are intermittently sent out; in time-dependent average, it is possible to evenly exhale the positive ions and the negative ions into the respective flow passages.
[0091] Besides, one ion generating cartridge 10 alternately operates the two ion generators 12 A, 12 B, so that the life of the ion generating cartridge 10 becomes double and it becomes possible to use the ion generating cartridge 10 for a long time.
[0092] The disposition position of the vertical wind-direction plate 21 that partitions the flow passage for the respective ion generating portions may be any position where it is possible to partition the flow passage for the air flow F 1 and the air flow F 2 ; if a fan that generates parallel air flows is used, it is also possible to dispose the vertical wind-direction plate 21 from the vicinity of the front end of the ion generating cartridge 10 .
[0093] In the ion generating cartridge 10 , the shape of a frame body 11 has a rectangular shape when viewing, from top, the ion generating surface from which the positive ion generating portion 13 A and the negative ion generating portion 13 B are exposed; when viewing from side, as shown in FIG. 4 ( b ), the ion generating surface 11 a is formed into a curved surface to match with the flow surface.
[0094] Besides, the frame body 11 includes: an input-output connector portion 19 that connects with an external power supply and performs input/output of a signal; a control board that includes a high-voltage generating circuit for generating a predetermined discharge voltage from electric power obtained via the input-output connector portion, and a drive control circuit, and controls the driving of the positive ion generating electrode and the negative ion generating electrode; the ion generators 12 A, 12 B of the double electrode type in which the two electrodes, that is, the positive ion generating electrode and the negative ion generating electrode are disposed close to each other; and the ion sensor 18 that detects the ions generated by the ion generators.
[0095] Besides, the frame body includes: a lever member 14 that has a handle portion which is held at times of insertion and pulling-out of the cartridge and a hook portion which fixes the cartridge at a predetermined position after the insertion; on sides of the frame body 11 , guide protrusion portions 15 , a butt surface 17 , and guide surfaces 16 that perform a guide function at the time of the cartridge insertion are disposed. The lever member 14 is rotatably disposed on a frame 11 c of a rear surface 11 b of the frame body 11 via a pivotal support portion 14 d.
[0096] The ion sensor 18 is a negative ion detection sensor that is disposed close to the negative ion generating portion 13 B of the ion generator 12 A and in a downstream side with respect to the negative ion generating portion 13 B; and detects the negative ions generated from the negative ion generating portion 13 B. For example, it is possible to convert an ion electric current, which is output in accordance with the concentration of negative ions captured by the electrode portion that captures ions, into a voltage to detect the ions; however, this type is not limiting, and it is possible to use an ion sensor which has a function to detect that more than a predetermined amount of ions are generated.
[0097] In the ion generator 12 A, the positive ion generating portion 13 A always generates the positive ions, while the negative ion generating portion 13 B always generates the negative ions. Besides, the predetermined positive and negative discharge voltages are applied to the respective needle-shape discharge electrodes at the same time, so that the amounts of the positive and negative ions are substantially the same as each other; by measuring the amount of either of the positive ions and the negative ions during the operation of the ion diffusing apparatus, it is possible to check whether the ion generator 12 A is operating normally or not. Besides, it is possible to presume whether the ion generating cartridge 10 which unitarily includes the ion generator 12 A and the ion generator 12 B is normal or not. In other words, by detecting the negative ions generated from the negative ion generating portion 13 B, it is possible to presume the deterioration degree of the ion generating cartridge 10 and to perform the maintenance.
[0098] The guide protrusion portions 15 disposed on the sides of the frame body 11 of the ion generating cartridge 10 are insertion guide portions that at the insertion time of the cartridge, butt against a guide frame 24 b (see FIG. 3 ( a )) which forms the ion generating apparatus housing portion; with the guide protrusion portions 15 on both sides of the frame body 11 butted against the guide frames on both sides, the ion generating cartridge 10 is pushed into.
[0099] The butt surface 17 is a portion that serves as an end surface of the frame body 11 when disposing the ion generating cartridge 10 into the ion generating apparatus housing portion; and is a surface that butts against a housing portion frame 25 , which forms the ion generating apparatus housing portion, to be positioned.
[0100] The guide surface 16 butts against a rear surface frame 23 of the lower lateral wind-direction plate 22 A to be positioned when fixing the cartridge 10 at a predetermined position by engaging the hook portion 14 c of the lever member 14 with an engagement portion 24 a (see FIG. 3 ( a )). As described above, the butt surface 17 for defining the insertion-end position and the guide surface 16 for defining the fix position serve as the position guide portion.
[0101] As described above, the ion generating apparatus housing portion for housing the ion generating cartridge 10 is formed at an inner place from the insertion opening 6 ; and is so structured as to include: the housing portion frame 25 for defining the insertion end of the cartridge; the guide frame 24 b for defining the sides of the cartridge; the cut-away portion 22 a from which the ion generating surface of the cartridge is exposed; the rear surface frame 23 for defining the fix position of the cartridge; and the engagement portion 24 a; wherein a number of the ion generating apparatus housing portions, the number of which is equal to the number of ion generating cartridges 10 , are disposed.
[0102] The lever member 14 , as shown in FIG. 3 ( a ), is rotatably disposed on the ion generating cartridge 10 via the pivotal support portion 14 d; is provided with: an arm 14 b; a handle portion 14 a that is held at the times of the insertion and pulling-out of the cartridge; and the hook portions 14 c that engage with the engagement portions formed on the apparatus main body to fix the cartridge after the insertion. Because of this, by holding and rotating the handle portion 14 a in an arrow direction D 1 in the figure, it is possible to engage the hook portion 14 c with the engagement portion formed on the apparatus main body.
[0103] The handle portion 14 a is bent by a predetermined angle that facilitates the operation and extended from the arm 14 b on which the pivotal support portion 14 d is disposed. Besides, the hook portion 14 c may be disposed on any portion of the lever member 14 that rotates, that is, may be disposed on the arm 14 b or the handle portion 14 a. In the present embodiment, as shown in FIG. 3 ( b ), a structure is employed, in which the handle portion 14 a is extended from the arm 14 b into a protrusion shape; and the arc-shape hook portions 14 c that engage with the engagement portions 24 a formed on the frame 24 of the apparatus main body are disposed at tip end portions of the arm 14 b formed on both sides of the handle portion 14 a.
[0104] Because of this, a structure is obtained, in which the hook portions 14 c are formed at intermediate portions of the lever member 14 : and by means of force smaller than the fit-in force between the hook portion 14 c and the engagement portion 24 a, it is possible to perform: the operation for holding the handle portion 14 a formed at the tip end of the lever member 14 , rotating the lever member 14 , and engaging the hook portions 14 c with the engagement portions 24 a to fix the lever member 14 ; and the operation for disengaging the hook portion 14 c from the engagement portion 24 a to release the lever member 14 , so that the operations become easy.
[0105] As described above, the ion generating cartridge is so structured as to include: the lever member 14 which includes the handle portion 14 a that is held at the times of insertion and pulling-out of the cartridge and the hook portions 14 c that fix the cartridge at the predetermined position after the insertion; the guide portions 15 , the butt surface 17 and the guide surfaces 16 that are formed on the side of the frame body of the cartridge and perform the guide function at the time of the cartridge insertion, so that it is possible to obtain the ion generating apparatus of the cartridge type that is easy to insert and pull out.
[0106] Next, a structure is described by means of FIG. 2 , in which the ion generating cartridge 10 which includes the lever member 14 having the above structure is disposed in the ion diffusing apparatus 1 .
[0107] As shown in FIG. 2 ( a ), an open-close cover 7 is opened to open the insertion opening 6 ; and the ion generating cartridge 10 is inserted from the opened insertion opening 6 . Here, the cartridge is inserted by holding the lever member 14 as if being pushed into until the butt surface 17 butts against the housing portion frame 25 . Besides, a structure is employed, in which in the time of the insertion operation, the guide protrusion portion 15 slides on the guide frame 24 b.
[0108] After the ion generating cartridge 10 is pushed into until the butt surface 17 butts against the housing portion frame 25 , as shown in FIG. 2 ( b ), the lever member 14 is pushed down to engage the hook portion 14 c of the lever member 14 with the engagement portion 24 a of the apparatus main body.
[0109] By means of the operation for pushing down the lever member 14 to engage the hook portion 14 c with the engagement portion 24 a of the apparatus main body, it is possible to fit the ion generating cartridge 10 into the cut-away portion 22 a formed through the lower lateral wind-direction plate 22 A. Besides, the guide surfaces 16 formed on the sides of the frame body of the ion generating cartridge 10 butt against the rear surface frame 23 of the lower lateral wind-direction plate 22 A, so that the fit-in posture is defined.
[0110] When the hook portion 14 c of the lever member 14 is engaged with the engagement portion 24 a of the apparatus main body, as shown in FIG. 2 ( c ), the ion generating cartridge 10 is fixed in such a posture that the ion generating surface of the ion generating cartridge 10 is exposed via the cut-away portion 22 a. This posture is a posture in which the ion generating surface is matched with the flow surface and exposed, so that it is possible to surely exhale the ions generated from the ion generating surface into the air flow.
[0111] Besides, a structure is employed, in which the in the state where the hook portion 14 c of the lever member 14 is engaged with the engagement portion 24 a of the apparatus main body, the opened open-close cover 7 is closable; however, as shown in FIG. 2 ( a ) and FIG. 2 ( b ), in the state where the hook portion 14 c is not fixed, the open-close cover 7 interferes with the handle portion 14 a of the lever member 14 when the open-close cover 7 is being closed. According to this structure, by means of the lever member 14 that is not disposed at the right position, it is possible to hinder the open-close cover 7 from being closed.
[0112] As described above, the structure is employed, in which the lever member 14 hinders the open-close cover 7 from being closed, so that it becomes possible to easily check whether the ion generating cartridge 10 is correctly disposed or not, which is preferable.
[0113] Besides, after the ion generating cartridge 10 is fixed at the predetermined position, the input-output connector portion 19 is connected to a connection terminal disposed in the apparatus main body to complete the disposition working of the ion generating cartridge 10 .
[0114] The ion diffusing apparatus 1 according to the present invention has the laterally long structure to include the plurality of ion generating cartridges 10 ( 10 A, 10 B, 10 C, 10 D); accordingly, it is preferable that the utilised fan 3 is a crossflow fan which has a fan length to send a wind to the line in which the plurality of ion generating cartridges are disposed. A crossflow fan has high quietness, is able to be operated from a breeze range, and is preferable as a fan that is used for the ion diffusing apparatus 1 which is installed in a living room where a quiet operation is required.
[0115] Besides, as shown in FIG. 1 ( a ), the flow passage partitioned into the plurality of streamline flow passages is branched into: a first flow passage 4 A partitioned by the lower lateral wind-direction plate 22 A disposed on the inner circumference side close to the crossflow fan and the next second lateral wind-direction plate 22 B; a second flow passage 4 B partitioned by the second lateral wind-direction plate 22 B and the next third lateral wind-direction plate 22 C; a third flow passage 4 C partitioned by the third lateral wind-direction plate 22 C and the fourth lateral wind-direction plate 22 D; and a fourth flow passage 4 D partitioned by the fourth lateral wind-direction plate 22 D and the upper lateral wind-direction plate 22 E, so that it is possible to adjust the flow speeds in the respective flow passages and carry the ions to a distant place.
[0116] For example, it is possible to set the wind speed K 1 in the first flow passage 4 A on the inner circumference side at the lowest wind speed, increase gradually the wind speed K 2 in the second flow passage and the wind speed K 3 in the third flow passage, and set the wind speed K 4 in the fourth flow passage on the outer circumference side at the fastest wind speed. According to this structure, the first flow passage 4 A having the slowest wind speed carries the ions generated by the ion generating apparatus (ion generating cartridge) 10 , so that the faster air flow that flows over the first flow passage 4 A serves as a wall, which is able to prevent upward diffusion of the ions. Besides, the ions are carried to a distant place by means of the Coanda effect of the air flows having the faster wind speeds, so that it becomes possible to form an ion flow region having a high concentration in a lower predetermined space.
[0117] In other words, by sending out the ions into the flow passage that is one of the flow passages partitioned into the plurality of streamline flow passages and has the lowest wind speed, it becomes possible to keep the ion concentration at a high concentration in a predetermined region of the room into which the air is sent; and becomes possible to effectively remove and kill the germs in the living space where people live. Besides, it is possible to change the wind speeds in the respective flow passages by adjusting the gaps among the upper lateral wind-direction plate, the lower lateral wind-direction plate, an the intermediate wind-direction plates and by adjusting the rotation speed of the crossflow fan.
[0118] An drive start-stop operation portion 8 (see FIG. 1 ( b )) for driving the ion diffusing apparatus 1 by operating the crossflow fan is disposed on the front side of the apparatus main body. In the drive start-stop operation portion 8 , besides an on-off switch, it is possible to dispose, for example: an operation mode setting portion that sets the rotation speed of the crossflow fan; a cartridge disposition time setting portion that sets disposition of a new ion generating cartridge; a timer setting portion; a replacement recommendation indication portion that recommends cartridge replacement after elapse of a predetermined time after the new ion generating cartridge is disposed and the operation is started; and a level indication portion that indicates whether the amounts of the ions generated by the respective ion generating cartridges are equal to, over, or ender the predetermined amounts.
[0119] Accordingly, because the service life of the ion generating cartridge is decided in advance, by setting the disposition of a new ion generating cartridge at the time the new cartridge is disposed, it is possible to perform indication for recommending the cartridge replacement in accordance with the apparatus use time from the disposition and to notify that the replacement time is coming. Besides, if the amount of the ions generated during the apparatus use is equal to or under the predetermined amount, the information is indicated, so that it is possible to know that the maintenance of the ion generating portion is necessary.
[0120] As described above, according to the present invention, the ion generating apparatus is formed as the cartridge type in which the ion generating surface has the curved surface that matches with the flow surface of the wind-direction plate; and which unitarily includes the insertion guide portion; the position guide portion; and the lever member that engages with the engagement portion of the apparatus main body to fix the ion generating cartridge, and it is made possible to insert and pull out the cartridge from the insertion opening that is formed on the outlet side which is formed through the apparatus front side, so that it is possible to obtain the ion generating cartridge that is easy to mount and demount form the apparatus front side. Besides, the ion diffusing apparatus has the structure in which the vertical wind-direction plates for partitioning the flow passage into the flow passages for the respective positive and negative ion generating portions are disposed, so that it is possible to obtain the ion diffusing apparatus that is able to evenly send out the ions far into the room while evenly generating the positive ions and the negative ions.
[0121] Besides, the ion generating cartridge is used, which includes: the ion generator that has the positive ion generating portion and the negative ion generating portion which are of the double electrode type in which the two ion generating electrodes are disposed close to each; and the ion sensor, so that it becomes easy to handle the ion generating apparatus of the cartridge type that generates the positive and negative ions in a large amount and it is possible to easily check whether the ion generating apparatus is operating normally or not. Because of this, it is possible to obtain the ion generating cartridge that is easily replaceable.
[0122] Moreover, the ion generating cartridge is formed as the two-stage ion generating type in which the ion generators including the ion generating portions of the double-electrode type are disposed in the two stages and in parallel with each other while the polarities of the ion generating electrodes of the ion generators are disposed at reversed positions, so that it is possible to exhale the positive ions and the negative ions into the same flow passage at the same time or alternately at the predetermined time intervals to mingle both ions of the positive ions and the negative ions at a predetermined concentration.
[0123] Besides, the structure is employed, in which the flow passage that extends from the fan to the outlet is partitioned into the multi-stage streamline flow passages; the lowest flow passage having the slowest wind speed is used as the streamline flow passage into which the ions are sent out; and the streamline flow passages having the faster wind speeds are formed successively, so that it is possible to form the air wall that prevents the ion diffusion and to form the predetermined space that where the ion concentration is kept. Moreover, the crossflow fan is used as the fan, so that it is possible to obtain the ion diffusing apparatus that has high quietness, is operable from a breeze range, and preferable to a living space where a quite operation is required.
[0124] Here, the target where the ion diffusing apparatus according to the present invention is not limited to a living room; and the ion diffusing apparatus may be used in rooms (e.g., waiting rooms of a station and a hospital, halls, classrooms and the like) where general people stay for some time. Besides, the ion diffusing apparatus may be used in a room which is ventilated by opening a window or by a ventilator if the ventilation rate is equal to or under a predetermined value. Besides, the ion diffusing apparatus may be used in a room which is air-conditioned by means of an air conditioner. Moreover, by disposing a plurality of the ion diffusing apparatuses according to the present embodiments away from each other, it is possible to secure a sufficient ion concentration in wide regions of spaces (e.g., lobbies of hotels, airports and the like) that are not partitioned.
INDUSTRIAL APPLICABILITY
[0125] The ion diffusing apparatus and the ion generating cartridge according to the present invention respectively become an ion diffusing apparatus that is able to keep the remaining amount of positive and negative ions in a living room at a high concentration and become an ion generating cartridge whose maintenance is easy, so that the ion generating cartridge becomes preferably applicable to an ion diffusing apparatus that secures a living room where people want to prevent disease infection.
LIST OF REFERENCE SYMBOLS
[0000]
1 ion diffusing apparatus
2 apparatus main body
3 fan
4 outlet
5 inlet
6 insertion opening
7 open-close cover
8 drive start-stop operation portion
10 ion generating apparatus (ion generating cartridge)
11 a ion generating surface
12 ion generator
13 A positive ion generating portion
13 Aa, 13 Ab positive ion generating electrodes
13 B negative ion generating portion
13 Ba, 13 Bb negative ion generating electrodes
14 lever member
14 a handle portion
14 c hook portion
15 guide protrusion portion
16 guide surface
17 butt surface
18 ion sensor
19 input-output connector portion
21 vertical wind-direction plate
22 lateral wind-direction plate
22 A lower lateral wind-direction plate
22 E upper lateral wind-direction plate | Disclosed is an ion diffusing apparatus that can realize easy replacement of an ion generator and can maintain a stable ion supplying capability. Also disclosed is an ion generating cartridge. In the ion diffusing apparatus, the ion generator is so configured that the generator is detachable for easy maintenance, and can deliver the positive ions and negative ions to a position remote from the apparatus in a room while uniformly generating positive ions and negative ions. An ion diffusing apparatus ( 1 ) includes an ion generator housing part. An ion generator ( 10 ) is housed in the ion generator housing part in such a posture that a positive ion generating part ( 13 A) and a negative ion generating part ( 13 B) are provided separately from each other in a direction crossing a flow direction of a stream from a fan ( 3 ), and an ion generating surface ( 11 a ) is exposed so as to conform to a stream flow surface of a stream flow passage extended from the fan ( 3 ) to a supply opening ( 4 ). The ion generator ( 10 ) is made to be a cartridge such that the ion generating surface ( 11 a ) thereof has a shape conforming to the stream flow surface of the stream flow passage, and the cartridge can be taken in and out from the ion generator housing part through an insertion port ( 6 ) provided on the supply opening ( 4 ) side at the front of the apparatus and is detachably housed in the ion generator housing part in such a posture that the ion generating surface is exposed to the stream flow surface. | 0 |
This application is a continuation of application Ser. No. 07/278,715, filed Dec. 2, 1988, now abandoned.
BACKGROUND OF THE INVENTION
This invention relates to a powder supply element particularly to an element for supplying polycrystalline silicon powder continuously into a crucible for use in a single crystal pulling apparatus.
Silicon single crystals are made by the conventional Czochralski method (CZ method). According to this method, a crucible is provided within a vacuum melting furnace in a single crystal pulling apparatus. Polycrystalline silicon in the crucible is heated into molten silicon by an annular heater which surrounds the crucible With pulling of a single crystal, polycrystalline silicon powder is supplied into the crucible so as to maintain a fixed height of the liquid surface of the molten silicon and to maintain the impurity concentration of the molten silicon constant (For example, the apparatus as described in Japanese Patent Application No. 103918/86 filed on May 8, 1986 may be used).
However, since the silicon polycrystal powder to be supplied has a particle size ranging from about 100 microns to about 3 mm, part of the fine particles after being ejected from a supplying pipe will be suspend in the air and reach the vicinity of the solid-liquid interface of the single crystal without falling directly onto the liquid surface of the molten silicon in the crucible. As a result, the uniformity of the crystal being grown deteriorates. Further, some part of coarse particles of the powder will reach the vicinity of the solid-liquid interface in a solid state without melting promptly.
The heat generated by the heater is transmitted from the side peripheral portion of the crucible and heat convection takes place in the molten crystal component. The current directions of the heat convection are an upward direction near the side peripheral portion of the crucible, an inward direction near the liquid surface of the molten crystal component, a downward direction near the central axis of the crucible and an outward direction near the bottom of the crucible, respectively, whereby the heat transmitted from the heater to the molten crystal component through the side peripheral portion of the crucible can be quickly transmitted toward the center of the crucible. Therefore, a temperature at the liquid surface of the molten crystal component is near a temperature at a solid-liquid interface of the single crystal in the crucible. Thus, the polycrystalline component powder cannot be quickly melted. Non-melted powder is apt to be mixed with the single crystal while it is being pulled so that the quality of the single crystal decreases.
SUMMARY OF THE INVENTION
The object of the present invention is to provide a pulling element whereby a powder to be supplied into a crucible for a single crystal pulling equipment can be dropped directly onto the liquid surface of a molten crystal component in the crucible while preventing the powder from floating in the air up to the vicinity of a solid-liquid interface of a single crystal to be pulled.
And it is also the object of the present invention to provide a separating device for a single crystal pulling apparatus in which a surface portion of the molten crystal component in the crucible can be prevented from flowing in the molten crystal component toward the center of the crucible.
The invention is directed toward an apparatus for supplying powder to a crucible containing a molten crystal component in a single crystal pulling device comprising means for separating the space above the surface of the molten crystal component into a first and second region, means for feeding the powder to the first region, the second region provided for pulling a single crystal from the molten crystal component, and means for supporting the separating means.
Preferably, the separating means and supporting means are made of high pure quartz, and the supporting means comprise plural rods.
More preferably, the separating means comprise a plate member which is rectangular in shape and disposed vertically. The plate member is fixed to a powder supply pipe with the supporting means between the plate member and the pipe. Both side edges of the separating means are close to but spaced from the inner peripheral surface of the crucible. The upper edge of the plate member is positioned above the opening end of the pipe, and the lower edge of the plate member is positioned lower than a height corresponding to the particle diameter of the supplied powder from the liquid surface of the molten crystal component. In this case, the powder supplied from the pipe can be prevented from floating in the air up to the vicinity of the solid-liquid interface, and it is possible to prevent the powder floating on the liquid surface form shifting up to the solid-liquid interface. The lower edge of the plate member may be positioned below or immersed into the liquid surface in the crucible. In this case, powder supplied from the pipe can be prevented from floating in the air and on the liquid surface up to the vicinity of the solid-liquid interface. The liquid surface and the space for supplying the crystal material can be held at a high temperature by the heat generated from a heater disposed along the side peripheral portion of the crucible. Thus, the powder supplied from the pipe can be melted quickly.
The plate member may be a semi-cylindrical member which is cut along a longitudinal plane including the diameter thereof. The semi-cylindrical member has a radius of curvature not larger than 80 mm, preferably 40 mm, if the inside diameter of the crucible is 16 inches.
The plate member may be a semi-elliptical member which is cut along a longitudinal plane including the major axis.
Preferably also, the separating means may comprise an annular wall the inner diameter of which is larger than the diameter of the single crystal to be pulled. The annular wall is placed coaxial with the crucible, has a lower end positioned below the liquid surface of the molten crystal component, and is fixed to the crucible with the supporting means between the annular wall and the crucible.
The inner diameter of the annular wall is larger than the diameter of the single crystal to be pulled, by 160-240 mm, preferably 200 mm.
The annular wall may comprise a plurality of rings, preferably two rings, which are placed coaxial with the crucible in multi-arrangement.
BRIEF DESCRIPTION OF THE DRAWINGS
By way of examples and to make the description more clear, reference is made to the accompanying drawings in which:
FIG. 1 is a perspective view showing a pulling element according to an embodiment of the present invention;
FIG. 2 is a perspective view showing another embodiment of the present invention;
FIG. 3 is a perspective view showing yet another embodiment of the present invention;
FIG. 4 is a vertical sectional view showing the setting of the pulling element according to an embodiment of the present invention; and
FIG. 5 is a partial cutaway view showing a modification of the setting shown in FIG. 4.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings, preferred embodiments of the present invention will be explained in detail.
In FIG. 1, an annular heater (not shown) is disposed around a cylindrical quartz crucible (cup-shaped crucible) 1 which is mounted in a vacuum within a vacuum melting furnace for use in a single crystal pulling apparatus. The inside diameter of the crucible 1 is 16 inches. Polycrystalline silicon contained in the crucible 1 is melted by the heat generated from the heater thereby to provide molten silicon 2 as a molten crystal component. In order to maintain the impurity concentration of the molten silicon 2 constant, a polycrystalline silicon powder supply means (not shown) supplies a polycrystalline silicon powder (crystal material) to a liquid surface 4 of the molten silicon 2 as indicated by arrow 20 through crystal material supplying pipe 3 made of quartz and having a bore diameter of 10 mm. The distal end of the pipe 3 is positioned near the peripheral portion of the crucible 1. The spacing between the open end of the pipe 3 and the liquid surface 4 is 20 mm. The particle size distribution of the powder supplied is from about 100 microns to about 3 mm.
A semi-cylindrical member 6 made of quartz and serving as a separate means is fixed by means of quartz rods 12 to an end portion of the pipe 3 so as to partially enclose the pipe 3 which is disposed above the liquid surface 4. The semi-cylindrical member 6 separates the space above the liquid surface into two. The separated space which includes the pipe 3 is the space for supplying the crystal material and the other separated space is the space for pulling a single crystal. The pipe 3 and the semi-cylindrical member 6 are fixed to the rods 12 by welding.
Preferably, the semi-cylindrical member 6 has a radius of curvature of 40 mm, a height of 50 mm and a plate thickness of 3 mm. The diameter of each rod 12 is 5 mm.
The semi-cylindrical member 6 is disposed in such a manner that a slight spacing is formed between each of both side edges of the semi-cylindrical member 6 and the inner peripheral surface of the crucible 1. The spacing between the lower edge of the semi-cylindrical member 6 and the liquid surface 4 is smaller than the diameter of fine particle contained in the powder supplied. As a result, not only the rotation of the crucible 1 is permitted but also the powder from the pipe 3 can be prevented from floating in the air outside the semi-cylindrical member 6, that is , coming up to the solid-liquid interface of a single crystal (not shown) to be pulled up.
The lower edge of the semi-cylindrical member 6 may be immersed, preferably 5 mm, into the molten crystal component 2. By doing so, not only the rotation of crucible 1 can be permitted but also the powder from the pipe 3 can be prevented from floating in the air or on the liquid surface 4 outside the semi-cylindrical member 6, that is, coming up to the solid-liquid interface of a single crystal (not shown) to be pulled up. In addition, the molten silicon 2 located inside the semi-cylindrical member 6 can be held at a high temperature by the heat generated by the heater. Thus, the powder supplied from the pipe 3 can be melted quickly.
Another embodiment of the invention will now be described with reference to FIG. 2. In FIG. 2, the same members as in FIG. 1 are indicated by the same reference numerals, and explanation on their structure and function will be omitted.
In FIG. 2, a curved plate 8 made of quartz and serving as a separate means has a radius of curvature of about 180 mm, a horizontal length of 150 mm, a height of 40 mm and a plate thickness of 3 mm. It comprises an arcuate plate portion 7 disposed vertically and coaxially with the crucible 1, and two flat plate portions 9 and 9' which are respectively provided at both side ends of the arcuate portion 7 integrally and obliquely toward the outer peripheral side of the arcuate plate portion 7. The flat plate portions 9 and 9' each has a horizontal length of 30 mm, a height of 40 mm and a plate thickness of 3 mm. The arcuate plate portion 7 is fixed to the pipe 3 by means of the rods 12 and separates the space above the liquid surface 4 into two. The separated space which includes the pipe 3 is the space for supplying the crystal material and the other is for pulling the single crystal. Spacing between the crucible 1 and the arcuate plate portion 7 is disposed in such a way that a slight spacing is formed between each of the side edges of the flat plate portions 9, 9' and the inner peripheral surface of the crucible 1. The lower edge of the curved plate 8 is immersed, preferably 5 mm, into the molten crystal component 2.
The embodiment of FIG. 2 has the same effects as those attained by the material supplying pipe of FIG. 1. In addition, the curved plate 8 has a further effect that the molten crystal component 2 can rotate smoothly with respect to the curved plate portion 7 with rotation of the crucible 1, because the arcuate plate portion 7 is provided along the circumference of the crucible 1.
In FIG. 3, an outer ring (annular wall) 10 is made of quartz and has a thickness of 3 mm, an inner diameter of 375 mm and a height of 20 mm. An inner ring (annular wall) 11 is made of quartz and has a thickness of 3 mm, a inner diameter of 325 mm and a height of 20 mm. The inner ring 11 is arranged coaxial with the outer ring 10. The outer ring 10 and the inner ring 11 are fixed by four rods 13 made of quartz which are placed at regular intervals. The diameter of each rod is 5 mm. The rods 13 are fixed to the rings 10, 11 by welding. Four rods 14 are fixed to the outer peripheral surface of the outer ring 10 at the positions corresponding to the rods 13, respectively, by welding means. The rods 13, 14 extend in radial directions. The rods 14 each has a diameter of 5 mm and is made of quartz.
As shown in FIG. 4, the rings 10, 11 are supported in the crucible 1, for example, by fixing the ends of the rods 14 onto the inner peripheral surface of the crucible 1 by welding.
Alternately, as shown in FIG. 5, the ends of the rods 14 can be inserted into a corresponding groove 17 formed in the crucible 1 to thereby be fixed in place.
In any fixing mode of the rods 14, the rings 10, 11 are positioned in a vertical direction such that the liquid surface 4 of the molten crystal component 2 in the crucible comes to a half of the height of the rings 10, 11, and the rings separate the space above the liquid surface 4 into three. The separated space which includes the pipe 3 is the space for supplying the crystal material and another which includes the center of the crucible 1 is for pulling the single crystal.
The liquid surface 4 is controlled so as to be maintained at a constant level thereby to prevent the liquid surface 2 from moving downward while the molten silicon is changed into a solid state in pulling the single crystal 15. For example, a controlled amount of polycrystalline silicon powder 5 is supplied through a pipe 3 into the crucible 1, by means of a polycrystalline silicon powder supply means (not shown). The distance between the bottom of the crucible 1 and the lower end of the rings 10, 11 is set in such a way that the heat convection of molten silicon 2 located below the lower end of the rings 10, 11 can take place without restriction within the whole horizontal sectional area of the molten silicon 2 as denoted by the arrows 18 in FIG. 4. The particle size distribution of the powder 5 ranges between about 100 microns and about 3 mm.
An electric heater 16 is provided near an intermediate portion of the pipe 3 for heating the powder 5 which is being transferred through the pipe 3 whereby the powder 5 can be easily melted in the crucible 1.
The operation of the crucible and its related members will now be explained.
When the annular heater (not shown) around the crucible 1 generates heat, the heat convection current 18 is produced in the molten crystal silicon or component 2 within the crucible 1. Because the rings 10, 11 are immersed in the molten component 2 by about 10 mm, the heat convection in the inward direction at the surface portion of the molten crystal component 2 can be prevented from taking place by means of the rings 10, 11. Therefore, the heat transmitted from the heater to the molten crystal component 2 through the side peripheral portion of the crucible 1 can be prevented from being transmitted to near the solid-liquid interface of the single crystal 15 to be pulled. As a result, the temperature increases particularly at a surface portion of the molten crystal component 2 located between the outer surface of the ring 10 and the inner surface of the crucible Thus, when the powder 5 is supplied through the pipe 3 into a space between the ring 10 and the crucible 1 as shown in FIG. 4, the powder can be easily melted in the surface portion of the molten crystal component.
Having described the invention as related to the embodiment shown in the accompanying drawings, it is clear that the invention is not limited by any of the details of description, unless otherwise specified, but rather the invention is to be construed broadly within its spirit and scope as set out in the accompanying claims. | Apparatus for supplying powder to a crucible containing a molten crystal component ina single crystal pulling device. The apparatus includes a separating member for separating the space above the surface of the molten crystal component into a first and second region, a feeding device for feeding the powder into the first region and a supporting device for supporting the separating device. The single crystal is pulled from the molten crystal component in the second region. | 8 |
This application claims the benefit of the filing date of provisional application Ser. No. 60/013487, filed Mar. 15, 1996.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates in general to a method for incorporating cellulose esters into cellulose, and more particularly to a method of immersing cellulose in a cellulose acetate solution.
2. Description of the Related Art
According to Kirk-Othmer, Concise Encyclopedia of Chemical Technology, (1985), p. 327, "Cellulose is a long linear polymer of anhydroglucose units and this is reflected in the thread-like structures of cellulose found in plant cell walls (elementary fibrils, approximately 3.5 nm in width and indefinite length) which are further laterally associated to provide strength (as microfibrils, generally 10-30 nm in breadth)." Cellulose is used in a number of common products, including facial and toilet tissue, disposable towels and paper. To improve strength and achieve other improved properties, it has been desired to incorporate cellulose acetate into these products.
The following discussion refers at places specifically to cellulose acetate. However, the discussion relates to other cellulose esters, such as cellulose propionate and cellulose butyrate. Additionally, a combination cellulose ester, such as cellulose acetate-butyrate in which one cellulose chain has acetyl and butyryl substitution, may be used. Further, a mixture of cellulose esters is possible.
Each anhydroglucose unit in a cellulose chain has three hydroxyl groups where ester substitution (such as acetate substitution) may occur. Cellulose esters may be formed by reacting cellulose and an acid anhydride yielding a carboxylic acid and a cellulose ester. The number of carbon atoms in the ester substituent is the same as the number of carbon atoms in the carboxylic acid and is one half the number of carbon atoms in the acid anhydride. This of course assumes that the acid anhydride is symmetrical, having the following form: ##STR1## Cellulose acetate-butyrate results from a reaction of cellulose, acetic anhydride and butyric anhydride.
Cellulose acetate is conventionally manufactured by a method shown schematically in FIG. 1. Cellulose pulp 2, derived from wood or cotton fibers, is supplied to a reactor 4. Acetic anhydride and acetic acid are also supplied to the reactor 4, from feed 6. Also present in reactor 4 is an acid catalyst, such as sulfuric acid. The cellulose and acetic anhydride are converted to cellulose acetate and acetic acid which leave reactor 4 in what is known as an "acid dope" 8. The acid dope may have a 20 wt. % to cellulose acetate concentration. The acid dope 8 is fed to a processing step 10. However, before going to the processing step 10, it is possible that the acid dope will be partially hydrolyzed to achieve the desired degree of ester substitution of the cellulose molecule. That is, after reaction in reactor 4, the cellulose molecule may be acylated such that all three hydroxyl groups have been acylated to replace the hydroxyl with an acetate. The cellulose molecule is said to be completely acetylated. To convert a portion of the acetyl groups back to hydroxyl groups, the acid dope may be placed in a reactor with the acid catalyst present and water to convert some of the acetyl groups back to hydroxy groups. As a result of partial hydrolysis, the degree of substitution may be 2.40 to 2.60. In the partial hydrolysis, the water also converts the remaining acetic anhydride to acetic acid. After partial hydrolysis operation, the acid catalyst may be neutralized in a separate reactor with a base. Because the acid catalyst is a strong acid such as sulfuric acid, the base used in neutralization will react preferentially with the acid catalyst without reacting with the acetic acid.
In the processing step 10, water is mixed with the acid dope to precipitate the cellulose acetate out of the acetic acid solution. A solution of water and 30 wt. % acetic acid 12 is fed to a concentrator 14, where the water is separated form the acetic acid, and then the acetic acid is recycled back to reactor 4 where the acetic acid serves as a solvent for the cellulose acetate. The cellulose acetate that is washed and dried in the processing step 10 is then dissolved in another solvent 16 in vessel 18. The other solvent 16 may be acetone. Then, the dissolved cellulose acetate 20 is fed to a spinnerette 22 which removes the solvent and forms a fiber. In paper applications, this acetate fiber could be mixed with cellulose to make paper.
The cellulose acetate achieved from the method shown schematically in FIG. 1 may be combined with cellulose to make paper.
The method shown schematically in FIG. 1 is relatively expensive to perform. To eliminate several of the production steps, it has been proposed to use the cellulose acetate directly after the hydrolysis step. This avoids several expense of process steps, but the process is still expensive.
When the cellulose acetate is combined with cellulose to make paper, the concentration of cellulose acetate must be maintained rather high to ensure that there is a good distribution in the cellulose. This too has resulted in added expense to the product, in this case, paper.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to reduce the processing steps necessary before cellulose acetate can be combined with cellulose.
It is a further object of the present invention to achieve a cellulose-cellulose acetate product having a lower concentration of cellulose acetate.
These and other objects are accomplished by method for producing cellulose containing a cellulose ester in which a cellulose ester-carboxylic acid solution (acid dope) is combined with a low vapor pressure solvent having a boiling point above 75° C. to achieve a mixed product. The ester substituent in the cellulose ester and the carboxylic acid have the same number of carbon atoms. The cellulose ester-acetic acid solution may be a cellulose acetate-acetic acid solution. The mixed product is then combined with cellulose, and water washing is performed to recover the carboxylic acid.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be explained in more detail in connected with the aid of the attached drawings in which like reference numerals represents like elements, wherein:
FIG. 1 is a diagram schematically representing a method of the related art; and
FIG. 2 is a diagram schematically representing a method according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 2, a cellulose ester-carboxylic acid solution (acid dope) 8 is fed to a first mixer 22. The acid dope 8 may be the same acid dope produced in the reactor 4 discussed above, and may have a 20 wt. % cellulose acetate concentration. That is, the acid dope 8 can be used directly without neutralization of the acid catalyst and without washing and drying in processing step 10. However, the cellulose acetate may be partially hydrolyzed to a degree of substitution of 2.40 to 2.60. More highly acylated cellulose acetate can also be used. Mixer 22 mixes the acid dope solution 8 with a solvent having a lower vapor pressure from feed 24 to achieve a "diluted dope" feed 25. The low vapor pressure solvent should have a boiling point above 75° C., more preferably above 95° C., and most preferably above 115° C. Acetic acid may be used as the low vapor pressure solvent. The acetic acid supplied to mixer 22 may be a 75 wt. % percent acetic acid solution in water. The diluted dope 25 is fed from first mixer 22 to a second mixer 26. Fluffed pulp 28 is also fed to the second mixer 26. The fluffed pulp may come from a pulp sheet roll 30, which is fed through a hammer mill 32. The pulp sheet roll 30 is a conventional roll such as that produced in paper making. Although chemical grade pulp sheets are to produce cellulose acetate, this more expensive cellulose should not be necessary. The hammer mill 32 chops up the sheet to make individual fibers. Other similar equipment beside the hammer mill may also be used.
In the second mixer 26, cellulose acetate is coated on the cellulose of the fluffed pulp. The temperature in the second mixer 26 is not critical, and may be between about 100° F. and 200° F., and preferably between 130° F. and 150° F. The time during which the cellulose is in contact with the diluted dope is determined in the continuous process shown based on the volume of the second mixer 26 and the flow rate into and out of the second mixer 26. The contact time is also not critical. In general, sufficient time must be allowed for the diluted dope to thoroughly wet the cellulose fibers. Contact times of from 2 minutes to about 10 minutes will generally be sufficient, although longer times may be used if desired.
From the second mixer 26, pump 34 pumps the contents of the second mixer 26 to a belt filter 36. In the initial portion 38 of belt filter 36 diluted doped is filtered off to a dope tank 40 from which pump 42 recycles the diluted dope back to the first mixer 22.
With the diluted dope being recycled, it is very easy to control the amount of cellulose ester impregnated into the cellulose. For example, if acid dope 8 is fed at a rate of 5 pounds per minute and contains 20 wt. % ester, then 1 pound per minute cellulose ester is being fed to the process. If the cellulose sheet from pulp sheet roll 30 is being supplied at a rate of 100 pounds per minute, then the resulting cellulose acetate content in the cellulose will be 1 weight percent. This is because the only place for the cellulose and cellulose acetate to leave the process is in the final product. Thus, controlling the process is a simple procedure.
After the initial portion 38 of belt filter 36, the impregnated cellulose undergoes a counter current water wash. That is, water is fed in one end through the material about to exit the belt filter 36. Then, the water containing some acetic acid is pumped to upstream portions of the belt until most of the acetic acid is removed. A four stage counter current wash is shown. From the last stage of the washing, the acetic acid solution leaving belt filter 36 may have a 30 wt. % acetic acid concentration. It is preferable that the concentration of acetic acid be sufficient enough so that an acid concentration process is economically feasible. It should be noted that because the solvent (acetic acid) has a low vapor pressure, it cannot easily be removed completely by an evaporation or boiling process.
Washed ester coated cellulose 44, which may be 15-20 wt. % solids, is supplied from the belt filter 36 to a centrifuge 46. The centrifuge 46 removes some of the liquid added in the washing. Although a centrifuge 46 is shown, any piece of equipment, such as a press, which de-waters may be used. This type of equipment is conventionally used in the paper industry.
From centrifuge 46, the de-watered ester coated cellulose 48 may be fed to a dryer 50. For efficiency, the de-watered cellulose 48 fed to dryer 50 should have moisture content of no more than 50 wt. %. The dried cellulose ("treated fiber") can then be subjected to further processing to make circuit boards, laminated products and various paper products. To make paper products, the treated fiber may be combined with untreated cellulose.
As an alternative to the above process, instead of using hammer mill 32 to break-up the pulp sheet, it is conceivable that the diluted dope can be supplied directly to the pulp sheet. In this case, the moisture content after washing may be 50 wt. %, and a centrifuge would not be necessary before drying.
In some instances, it may be desired to use wet ester coated cellulose directly in further processing. If this is desired, the cellulose from belt filter 36 may be shipped directly or the de-watered ester coated cellulose 48 from centrifuge 46 may be shipped.
The concentration of cellulose acetate in the acid dope 8 is not critical, but will depend on some extent upon the desired degree of penetration into of the cellulose microfibrils by the cellulose acetate. In general, the concentration of cellulose acetate in the acid dope 8 should be between 0.5 wt. % and 25 wt. %. Dopes which are too concentrated will result in the excess dope being difficult to remove from the cellulose, particularly at lower temperatures.
EXAMPLES
Example 1
An acid dope was diluted with acetic acid and then heated to 140° F. Finely divided cellulose, prepared by disintegrating a commercial cellulose pulp sheet, was stirred into the diluted dope. The ratio of diluted dope to cellulose was 17:1 in all cases, but the dope dilution (acetic acid to acid dope) was varied. While maintaining the mixture at 140° F., it was stirred for approximately five minutes, then filtered with a vacuum using Buchner filter to remove as much dope as possible. The residue was washed with hot water until it no longer smelled of acetic acid. Then, the residue was filtered and dried. The percentage of cellulose acetate in the treated fiber (cellulose coated/impregnated with cellulose acetate) was determined based on the dry weight of cellulose before and after impregnation with cellulose acetate. The results are shown in the following table. As can be seen, as the doped dilution decreased, the percentage of cellulose acetate in the product treated fiber decreased with increased dope dilution.
______________________________________ Wt. % Cellulose AcetateExperiment Dope Dilution In Treated Fiber______________________________________1 29:1 1.0%2 15:1 1.0%3 7:1 3.5%4 3:1 5.2%5 1:1 50.0%______________________________________
Example 2
The procedure of Example 1 was followed using Weyerhaeuser pulp broken into individual fibers using a hammer mill which had been set to its highest speed setting and slowest cellulose feed to breakup the fibers as much as possible. The acid dope used was taken from cellulose acetate production at the stage at which neutralization of the acid hydrolysis catalyst had been completed. The acid dope was diluted with 75 wt. % acetic acid, and the ratio of acid dope to acetic acid was varied as will be discussed in connection with below table. The ratio of diluted dope to cellulose was 17:1 in all cases.
The diluted dope was placed in a constant temperature bath. After the temperature stabilized, 40 grams of fluffed cellulose pulp was added. The mixture was stirred for approximately 2 minutes, then filtered on a Buchner funnel to remove as much excess dope as possible. Then, the residue was pressed with a rubber dam. The weight of the recovered diluted dope was recorded, and the residue was washed on the Buchner funnel with hot water without applying a vacuum for 10 minutes. Then, applying a vacuum, the residue was further washed until there was no residual odor of acetic acid. The pulp was finally washed with 200 mL of deionized water, sucked as dry as possible, and dried in an oven overnight. The below table shows the dope dilution, that is, the ratio of acid dope to acetic acid. The below table further shows the temperature in the constant temperature bath and the weight of the dry product. The percentage of cellulose acetate in the treated fiber was calculated by subtracting the original weight of the fibers (40 g) from the weight of the treated fiber.
______________________________________ Wt. % Cellulose Temperature Wt. Dry Acetate in TreatedSample Dope Dilution °F. Product g Fiber______________________________________1 1:1 140 64.3 382 1.5:1 140 50.8 213 2:1 140 45.8 134 1:1 130 66.8 405 1.5:1 130 48.3 17______________________________________
Example 3
5 wt. % cellulose acetate treated fiber, prepared as described in the preceding examples, was mixed with 95 wt. % untreated cellulose and cast into paper sheets in a traditional paper making process. The percentage of cellulose acetate in the treated fiber was varied. The below table reflects the percentage of cellulose acetate in the treated fiber, not the percentage of cellulose acetate in the resulting sheets, which would be about 5% of the values in the table. The break-point tensile strength was determined, and is also shown in the below table. It is somewhat remarkable that the paper made from treated fiber having a 1 wt. % cellulose acetate concentration exhibits a substantial increase in tensile strength. This increase the strength of paper at very low levels of cellulose acetate.
______________________________________ Wt. % AcetateSample in Treated Fiber Tensile Strength______________________________________1 0 52862 0 54373 0.3 68614 0.5 52305 0.8 61586 1 64517 1.2 70128 3.5 60969 5.2 582110 5.6 593611 50.0 596112 50.0 5868______________________________________
While the invention has been described in connection with preferred embodiments, it will be understood that modifications thereof within the principles outlined above will be evident to those skilled in the art. Thus, the invention is not limited to the preferred embodiments, but is intended to encompass such modifications. | A method for treating cellulose with cellulose ester for use in various paper products involves reacting cellulose and an acid anhydride to form a cellulose ester-carboxylic acid solution. Acetic anhydride may be used as the acid anhydride, and a cellulose acetate-acetic acid solution may formed as the resulting cellulose ester-acetic acid solution. The cellulose acetate-acetic acid solution is diluted in a mixer, with additional acetic acid. Bulk cellulose is milled into cellulose fibers, and the diluted cellulose acetate-acetic acid solution diluted is combined with the cellulose fibers to achieve a treated fiber. Excess cellulose acetate-acetic acid solution is removed from the treated fiber and recycled to the mixer used in dilution. The treated fiber is water washed followed by removing water from the washed treated fiber. This product can then be used in paper making to produce a sheet for circuit boards, laminated products, and various paper products. | 3 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. provisional patent application Ser. No. 61/786,816 filed Mar. 15, 2013.
FIELD OF THE INVENTION
[0002] The present invention relates generally to a system for managing marketing programs using a web-based computer program to link consultants, advertising agencies, clients and media outlets for the dynamic creation, modification and placement of advertising materials. More particularly, the present invention relates to an interactive system wherein a client and a consultant create a customized marketing plan for the client using a consultation automation wizard.
BACKGROUND OF THE INVENTION
[0003] Advertising programs typically are created by advertising agencies on behalf of clients that desire to advertise products and/or services locally, nationally, or both. The advertising agencies control the “assets” (the advertising materials to be used) and placement with the media. Thus, changes and customization for different local markets can be costly and time consuming since the client must return to the advertising agency each time.
[0004] Ad Giants, LLC is a next-generation marketing services company based in Dallas, Tex. Its flagship product, the Ad Giants ONE System®, is an intuitive, online marketing automation system that enables companies to protect and control their most valuable asset, their brand. It allows users to quickly and easily customize, order, and track corporate-approved marketing materials and campaigns for local use. It streamlines work flow, ensures field-level compliance to brand standards, reduces overhead, eliminates production waste, tracks results and boosts marketing ROI.
[0005] The Ad Giants ONE system provides customized localization for business marketing. The ONE system is a proprietary simple-to-use online system that enables a business user to store, manage, customize, localize, personalize, distribute and fulfill all of the company's marketing content. The system saves valuable time, eliminates waste, reduces field support personnel and, most importantly, helps maintain total brand consistency. The Ad Giants ONE system can meet present and future needs. It is simple to use and requires little to no user training. The system lowers costs and improves the end-to-end workflow. It can manage back-end vendors for fulfillment. The Ad Giants ONE system is continuously improved with the addition of new features.
[0006] U.S. Pat. No. 7,596,561, issued on Sep. 29, 2009, covers a system for marketing management including dynamic advertisement creation and customization. An authorized user connects to a database through the Internet to access and modify any of a plurality of advertisements each including one or more templates for creating a display of the stored advertisement. The system displays a wiseguy for interaction with the authorized user by speaking instructions, helpful hints, and questions and being interactive in response to inputs by the authorized user. U.S. Pat. No. 7,596,561 is incorporated herein by reference in its entirety.
[0007] U.S. Pat. No. 8,271,507, issued on Sep. 18, 2012, relates to a method for marketing management including dynamic advertisement creation and customization by the authorized user. The method enables a personalized message between the authorized user and a prospect, and an online response path for the prospect in the form of a personalized URL (pURL), while tracking and monitoring an activity of the prospect, allowing the authorized user to set qualifying thresholds related to the activity of the prospect and assign the prospect to at least one responder to follow-up and engage the prospect when the qualifying threshold is achieved. U.S. Pat. No. 8,271,507 is incorporated herein by reference in its entirety.
[0008] U.S. Patent Appl. Publ. No. 2011/0126121 A1, relates to a method for marketing management including authorized user modification of advertising assets stored in the database. A fulfillment party can remotely connect to the system for executing a marketing program including a professional advertisement created through the modification of a selected one of the modifiable advertising assets in response to an order from one of an advertising agency and the authorized user. U.S. Patent Appl. Publ. No. 2011/0126121 A1 is incorporated by reference herein in its entirety.
[0009] Users of the foregoing systems sometimes require human intervention to identify, define, plan, design, customize, order and execute marketing campaigns. Conventionally, such human intervention is provided by advertising agencies and personnel employed thereby. Such human consultation is typically inefficient, due to the time required to identify the need for marketing services and to plan and implement advertising campaigns. Such human consultations are also typically expensive and have historically been available only to large companies having the resources available to engage advertising agencies.
[0010] Additionally, human consultants are typically hired on the basis of prior experience and history in marketing, and typically also develop such expertise in limited areas. More than one consultant is typically required to implement different marketing campaigns, which further increases the inefficiency and cost of utilizing an advertising agency. Moreover, there does not exist an easy, repeatable method for augmenting or training human consultants except for investing the time required for the consultant to develop experience and history through design and development of actual marketing campaigns.
[0011] It would be desirable to provide a simple-to-use online system and method that enables a business user to create, store, manage, customize, localize, personalize, distribute and fulfill all of the company's marketing content, while efficiently allowing human intervention supported by the online system. Further, it would be desirable to provide a system and method for efficiently creating sophisticated and qualified individuals to act as qualified human consultants in support of a simple-to-use online marketing system. It would further be desirable to provide a consultative system and method for use by small and mid-size businesses (SMBs) who are looking for the same level of high-quality marketing presence that their larger competitors enjoy, but at a much more affordable cost, and to design a product that would allow SMBs to locate, create, plan, and execute top-of-the-line marketing campaigns that will help them grow their customers and build their businesses, all in one convenient location.
SUMMARY OF THE INVENTION
[0012] In concordance with the instant disclosure, a simple-to-use online system that enables a business user to create, store, manage, customize, localize, personalize, distribute and fulfill all of the company's marketing content, while efficiently allowing human intervention supported by the online system, has surprisingly been discovered.
[0013] In one embodiment, an automated consultative system for marketing management includes a computer program that facilitates a consultation between an authorized user and a human consultant. During the consultation, the human consultant maps a user need to one or more marketing objectives, interacts with the computer program to identify one or more tactics that are relevant to accomplishing the one or more marketing objectives; selects from the one or more tactics identified by the computer program to cause the computer program to identify marketing packages available to implement a selected tactic; selects the desired marketing package to cause the computer program to incorporate the marketing package into a marketing plan; then publishes the marketing plan, allowing the computer program to facilitate selection of a marketing package by the authorized user to implement a selected tactic.
[0014] In another embodiment of the invention, an automated consultative system for marketing management includes a database storing a plurality of marketing packages for implementing a marketing campaign. An administrator server computer is connected to the database and is running a computer program. The system permits a login to the administrator server computer by an authorized user at a remote computer to access the database. The remote computer is a user computer having a processor which is remotely connected to the server computer. The remote computer displays tools for use by the authorized user. The remote computer further provides an interconnection with a human consultant for interaction with the authorized user upon receiving a request by the authorized user. The human consultant maps a user need to one or more marketing objectives, interacts with the computer program on the administrator server computer to identify one or more tactics that are relevant to accomplishing the one or more marketing objectives; selects from the one or more tactics identified by the computer program, the computer program further identifying marketing packages available to implement a selected tactic; selects the desired marketing package to cause the computer program to incorporate the marketing package into a marketing plan; then publishes the marketing plan, allowing the computer program to facilitate selection of a marketing package by the authorized user to implement a selected tactic.
[0015] In other embodiments, the computer program displays tools for use by the consultant for identification or selection of one or more of the objectives, tactics, and marketing packages. The computer program may further allow the consultant to capture information about the authorized user, and may allow the consultant to selectively annotate user information with notes and tasks. The computer program may optionally provide the consultant with information about authorized users assigned to the consultant and may allow the consultant to track execution of a selected marketing package. The computer program may provide a graphical representation of open marketing plans to allow one of the consultant and the authorized user to track marketing package implementation, progress and status.
[0016] The Ad Giants MODsocket® system and method contains a variety of industry-specific marketing, advertising, and interactive direct marketing templates, as well as consultation and other marketing services, and support tools for implementing, tracking and managing marketing campaigns.
[0017] The MODsocket method and system is an embodiment and extension of The ONE system designed to be used by small and mid-size businesses (SMBs) who are looking for the same level of high-quality marketing presence that their larger competitors enjoy, but at a much more affordable cost. Additionally, the MODsocket method and system enables human consultants as an optional new embodiment of the wiseguy feature identified in U.S. Pat. No. 7,596,561, and extends The ONE system to provide a consultation automation feature.
DESCRIPTION OF THE DRAWINGS
[0018] The above, as well as other advantages of the present invention, will become readily apparent to those skilled in the art from the following detailed description of a preferred embodiment when considered in the light of the accompanying drawings in which:
[0019] FIG. 1 is a schematic block diagram of the communication interconnection between parties using the system and method according to the invention;
[0020] FIG. 2 is a flow diagram of the communication interconnection between parties using the system and method according to the invention;
[0021] FIG. 3 is an exemplary screen display of an interface for initiating a human consultation using the system and method according to the invention; and
[0022] FIG. 4 is a schematic block diagram of the automated consultative method and system according to the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0023] The following detailed description and appended drawings describe and illustrate various exemplary embodiments of the invention. The description and drawings serve to enable one skilled in the art to make and use the invention, and are not intended to limit the scope of the invention in any manner. In respect of the methods disclosed, the steps presented are exemplary in nature, and thus, the order of the steps is not necessary or critical.
[0024] The MODsocket method and system allows a User to: 1) Drive sales with professional marketing; 2) Delegate marketing execution so that the User can focus on running the business; and 3) Save time and money while growing the business. The MODsocket method and system provides: 1) Expert marketing advice; 2) A complete set of marketing resources; 3) The User's own convenient, affordable marketing department. By enabling a human consultant within the MODsocket method and system, the present invention allows human intervention supported by the consulting automation tool.
[0025] With reference to FIG. 1 , a User, a Consultant and administrator server computer or terminal communicate through an Ad Giants server 10 connected to a User terminal 12 , a Consultant terminal 14 and an Administrator terminal 16 . The terminals communicate by any suitable means such as Internet connections for the terminals 12 and 14 and an Intranet connection for the terminal 16 . The terminals can be, by way of non-limiting examples, personal computers, tablet computers, cell phones, PDA's.
[0026] A MODsocket website maintained by “Ad Giants” is operated on the server 10 . The MODsocket.com website provides Do-It-Yourself (DIY) marketing resources and implementation assistance. However, a need has been identified wherein some Users of the automated systems require human intervention to identify, define, plan, design, customize, order and execute marketing campaigns. A MODsocket Personal Marketing Consultant is available to provide initial and ongoing consultation and marketing recommendations. The Personal Marketing Consultant is a member of a Virtual Marketing Team that provides turn-key marketing campaign design and execution and periodic campaign reviews and updates. The Consultant can be considered as an extension of the wiseguy described in the above-identified Ad Giants U.S. Pat. No. 7,596,561.
[0027] The method according to the present invention begins with a User login 20 at the MODsocket website. Once the User is identified or has entered information sufficient to be identified, the website displays a set of tools at “Display Tools” 22 that are available to the category of user. If the User desires a Human Consultant, a connection to a Human Consultant through a consultant terminal 14 ( FIG. 1 ) is provided at “Connect to Consultant” request 24 . In one embodiment, the Consultant 26 is quickly provided from an existing queue of qualified consultants trained to use the MODsocket method and system. Alternatively, the “Connect to Consultant” request 24 may initiate an appointment at a date and time selected by the User and a customer call-back by the assigned Consultant 26 , as desired.
[0028] As shown in FIG. 3 , once connected to the MODsocket website, a User may select a meeting with a Personal Consultant 32 , or optionally may select a Do-it-yourself method 30 . To facilitate the process, the User may submit preliminary information via a proprietary, simplified JumpStart Audit form. Once assigned to the User, the Consultant performs a review of the JumpStart submission in preparation for an initial consultation with the User to assess the needs of the User as a preliminary step to generating marketing recommendations.
[0029] Thus, a User starts the MODsocket process for working with a Personal Consultant with an initial consultation with the Personal Consultant. The Consultant may provide, as non-limiting examples, an introduction and presentation of Consultant credentials; an initial marketing review and marketing needs verification (preferably based on the JumpStart submission); an overview of the MODsocket process and services subscription options; and schedule a follow-up call where the marketing plan and recommendations will be provided by the Consultant to the User. The User may select a subscription option at this point and the initial consultation event with notes and To-Dos is captured in the consultation node.
[0030] Alternatively, after the introduction and presentation of the credentials of the Consultant, the MODsocket process proceeds as shown in FIG. 4 . The Consultant develops a marketing plan 40 . The objectives of the marketing plan process are: 1) Review User needs established in the initial consultation; 2) Develop marketing recommendations and tactics; and 3) schedule a follow-call to review and act on the marketing recommendations that the Consultant has developed.
[0031] The MODsocket method and system is built based on a philosophy that all marketing efforts, including the marketing efforts arranged through the MODsocket system, are intended to support a finite number of objectives. Each of the finite number of objectives is supported, in turn, by a finite set of tactics that are capable of meeting the objectives. The MODsocket system includes a plurality of predefined and customizable advertising packages that may be aligned with each of the tactics capable of meeting the finite number of objectives.
[0032] Thus, once the jumpstart evaluation is completed, the Consultant may proceed to inquiries regarding the needs of the User. The Consultant has received training in how to assess the needs of the User and to correlate those needs to a set of pre-defined Objectives, which are finite in number. Accordingly, the Consultant works with the User and user-supplied information supplied via the JumpStart audit to map the needs of the User to the Objectives, indicated at reference 42 . The identified Objectives are fed to the Server 44 , which in turn identifies a set of Tactics at reference 46 that are capable of meeting the Objectives identified at 42 .
[0033] The Consultant selects an applicable Tactic at reference 48 from the Tactics identified at reference 46 , for implementation as a marketing effort. The selected Tactic is received by the server 44 , which further identifies various marketing packages at reference 50 offered through the MODsocket method and system that are available to accomplish the selected tactic. Upon identification of particular marketing packages at reference 50 , the MODsocket method and system may insert a Store Package Content node for identified packages. The Store Package Content node may include key package information as well as the marketing objectives and tactics that the package supports. Information from the Store Package Content node may then be utilized by the Consultant to record and distribute meeting notes, and/or create and distribute marketing recommendations and plans, as further described below.
[0034] At reference 52 , the Consultant selects one or more specific marketing packages to achieve the selected Tactic. The MODsocket consulting process & marketing plan automation stores the selected package data elements. As non-limiting examples, the store package type may include data elements such as: Package Title or Name; Package Description; Package Price; Package Image; Package Link/URL; and Package Objective/Tactic. The server 44 receives the selected marketing package and creates a marketing plan at reference 64 .
[0035] The Consultant thereafter reviews the marketing plan with the User, shown at reference 66 . The Consultant may make the marketing plan available to the User in advance of the marketing plan review, or may present it to the user in real time. The User selects and purchases recommended packages from the marketing plan at reference 68 . Thereafter, the Consultant works with the user to ensure implementation of the selected package, while the MODsocket system and method provides tools for tracking the consultation, as well as for tracking implementation and execution of the marketing plan. In particular, the Consultant may include within the documentation of the MODsocket method and system certain Consultant's Notes 54 visible to only the Consultant and other administrative personnel, which the Consultant can create and edit at any time. Both the Consultant and the User may include a Meeting Notes Node 56 . As a non-limiting example, the Meeting Notes Node 56 may be of the form shown in Table 3 below for display on a computer screen. As shown in Table 3, the MODsocket method and system allows population of the note node with freeform text areas, attachments and follow-up/checklist items. Threaded comments on the notes are also supported. Additionally, the Consultant is empowered to send meeting notes and amend notes after they are sent.
[0036] Additionally, the MODsocket method and system may allow the Consultant and the User to add to or adjust a Schedule 58 for implementing the marketing plan. The Consultant may further have access to Track Execution data 60 that allows the Consultant to track execution of the marketing plan. Optionally, the MODsocket method and system may provide tracking information to both the User and the Consultant 62 . Tracking information 62 may be provided in a graphical format, such as red-yellow-green indicia or a timeline format, to provide an easily readable visual reference that allows both the User and the Consultant to track implementation and execution of the marketing plan.
[0037] The interaction between the User and the Consultant is coordinated by an Administrator through the Administrator terminal 16 ( FIG. 1 ), which may be remote or local. The Administrator view generated by the MODsocket system displays an area for the Administrator to: view and edit all scheduled and historic consultations; view/filter consultations by date, Consultant and by User; view and set/edit consultant booking schedule; and assign/reassign Consultants to certain bookings.
[0038] According to the present invention, the Consultant creates a marketing plan by selecting recommended marketing objectives and tactics from a preset list of key marketing objectives and tactics. The MODsocket system presents the Consultant with a set of applicable MODsocket packages based on the selected objectives and tactics. The Consultant selects applicable packages, often with input from the User. The MODsocket system auto-creates the User's “Marketing Recommendations” based on the Consultant selections and typed explanatory text, then sends the auto-generated marketing plan to the Consultant and/or the User via email or presents the plan directly via the system. Threaded comments on the recommendations are supported.
[0039] The Consultant builds the marketing plan by entering descriptive text and selecting pre-determined objectives, tactics and associated store packages as can be displayed on a computer screen. As a non-limiting example, a template for the Consultant to use in entering text and selecting pre-determined objectives, tactics and associated store packages is shown in Table 1 below.
[0040] The plan is subsequently presented by the Consultant to the Client. During this presentation, the Client may elect to act on the recommendation by clicking the embedded link within the plan and purchasing the associated Package from the MODsocket Store.
[0041] As a non-limiting example, an auto-generated Marketing Plan view/template of the type generated by the MODsocket method and system is shown in Table 2 below.
[0000]
TABLE 1
□ Understanding the Customer (Objective)
□ Primary Research (Tactic)
Recommended Packages
□ Web Survey
□ Focus Group Package 1
□ Focus Group Package 2
□ Secondary Research (Tactic)
Recommended Packages
□ Report 1
□ Report 2
□ Report 3
□ Building the Brand
□ Defining/Improving Business Identity
. . .
□ Developing/Improving Key Messaging
. . .
□ Developing/Improving Visual Brand Elements . . .
□ Building Awareness
□ Traditional advertising
. . .
□ Internet marketing
. . .
□ Social media
. . .
□ Generating Demand
□ Direct Sales
. . .
□ Referral Programs
. . .
□ Lead generation
. . .
□ Supporting Sales
□ Collateral . . .
□ Event Marketing
. . .
□ Customer Engagement Systems . . .
Actions
CREATE RECOMMENDATIONS
AMEND RECOMMENDATIONS
[0000]
TABLE 2
Introduction:
Editable text area with boilerplate text
Recommendation Overview:
Editable text area with boilerplate text
Recommended Objectives & Tactics
Objective 1: Editable text area with boilerplate text
□ Understanding the Customer
Associated MODsocket
Packages
□ Primary Research
Package Name: Focus Group Package 1
Description: This is the package
description . . .
Price: $X
□ Secondary Research
Package Name: Report 3
Description: This is the package
description . . .
Price: $X
Objective 2: Editable text area with boilerplate text
□ Building the Brand
Associated MODsocket Packages
□ Developing/Improving Visual
Package Name:
Custom Logo Package
Brand Elements
Description: This is the package
description . . .
Price: $X
Summary & Next Steps:
Editable text area with boilerplate text
Actions
PREVIEW PLAN
PUBLISH PLAN
[0042] The user view generated by the MODsocket system displays an area for the User to submit jumpstart information and request a consultation. In a “My Marketing Journal” display area the User can view the consultation and recommendation history and the Meeting Notes 56 . Key fields are Date, Item (Title), and Author. The “My Marketing Journal” display area may also permit the submission of a new jumpstart information and request for a new consultation.
[0043] The MODsocket method and system thus automates the consulting process and marketing plan creation. The MODsocket method and system effectively memorializes and communicates User interactions using a Notes feature and associated comments. The User thus has a view that shows all Consultant interactions, including filtered, user-viewable Notes, Plans, and Comments, which is accessible from the “My Marketing Journal” link on the MODsocket.com website. The MODsocket method and system also memorializes and communicates marketing recommendations, including marketing Plans and associated comments provided by the Consultant. Thus, the Consultant view generated by the MODsocket system and method may display an area for the Consultant to view scheduled and historic bookings and associated consultations; view users previously consulted with and their associated consultations; set/edit own booking availability with notification to an Administrator; schedule new/follow-up events/consultations; and create/edit/revise and send notes, next steps, recommendations for marketing plans, etc. to memorialize events/consultations. Additionally, the MODsocket method and system memorializes a User history by providing for a Journal that may include, as non-limiting examples, a chronology of Notes, Plans and associated comments.
[0000]
TABLE 3
Pre-Meeting Notes
This is a pre-meeting note text area. It allows free-form text and
basic wysiwyg formatting. This can be edited with revisions.
The User cannot see this field in their journal.
Meeting Notes
This is a meeting notes text area. It allows free-form text and basic
wysiwyg formatting. This can be edited with revisions. The User
can see this field in their journal.
Follow-up Items
□ Item 1
□ Sub-item (can be checked off when completed) . . .
□ Sub-item 2
. . .
□ Another Sub-item
. . .
Actions
SEND MEETING NOTES
AMEND MEETING NOTES
SCHEDULE NEXT MEETING
[0044] Advantageously, the MODsocket method and system additionally provides a mechanism is to introduce individuals to the skills necessary to become a Consultant, because the MODsocket system itself can be utilized as a training system. As noted previously, the MODsocket method and system is built based on a philosophy that all marketing efforts, including the marketing efforts arranged through the MODsocket system, are intended to support a finite number of objectives. Each of the finite number of objectives is supported, in turn, by a finite set of tactics that are capable of meeting the objectives. The MODsocket method and system, when applied as a method and system to train consultants to provide marketing support, easily and quickly trains consultants to see the world of marketing in light of the finite number of objectives utilized in the MODsocket method and system. Thus, after training using the MODsocket system and method, a Consultant is able to use the training to focus on customer needs, and to map those needs to the objective. Equally as important, Consultants trained using the MODsocket method and system of training are able to quickly apply automated filters to enable the Consultant to filter out things that do not apply, thus ensuring that the Consultant is not distracted and is able to efficiently provide support and assistance. The MODsocket method and system of training Consultants thus provides a way to efficiently and quickly acquire desired marketing experience instead of relying on a long career in which to acquire real-world experience. In fact, the MODsocket method and system of training is able to train Consultants having widely varying backgrounds and produce consultants having a requisite proficiency much faster than relying on real-world experience over a lifetime of practice. Put another way, the MODsocket method and system of training is able to quickly and easily create a qualified and trained Consultant having an augmented communication skillset without relying on a specific individually acquired skill set, which lowers the necessary pre-requisite consultant skill level over the skills needed to conventionally accomplish the same thing
[0045] Additionally, because a Consultant trained using the MODsocket method and system is taught to identify customer needs across every one of the finite objectives, a single Consultant is able to implement significantly different marketing campaigns which normally require multiple consultants to implement, thereby reducing cost and increasing efficiency over using a conventional advertising agency.
[0046] As a result, the MODsocket method and system of training, in combination with application of the MODsocket method and system itself, implements an automation of the consulting and the resource package discovery to enable a trained and qualified consultant to be able to focus on customer needs, to map the customer needs to the objective, and to apply MODsocket training to pick the right tactic. When the consultant function is properly performed, the automation built into the MODsocket method and system identifies packages that satisfy the needs of the client, so that the Consultant need not be continuously aware of new packages and programs capable of implementing a tactic for achieving an objective.
[0047] The MODsocket method and system of training may also be used to continuously improve the services provided to customers. Because all transactions are monitored by an Administrator, additional modules may be implemented to ensure that the quality of the Consultant remains aligned with a desired quality and quantity of marketing program fulfillment. As a non-limiting example, the Administrator may be able to track a Consultant's performance using any applied metric, such as number of consulting meetings, amount of programs sold, speed of program implementation, satisfaction of the customer, and the like.
[0048] The MODsocket method and system thus provides a User with access to a complete team of marketing professionals: strategist, analyst, designer, and copywriter, project manager, and other specialized resources as required. The MODsocket method and system automates the delivery of marketing resources, while at the same time providing a qualified and trained Consultant that assists the User with defining and executing the right marketing program for his/her business. By automating the process for delivering marketing resources, MODsocket Users have efficient access to a host of professional marketing resources, including: expert consultation; libraries of print, email, direct mail, interactive, social media and broadcast campaigns; mobile marketing; and marketing services including custom design, research and more. Additionally, the MODsocket method and system of training ensures that a properly qualified and trained Consultant is sufficiently knowledgeable and experienced to be able to effectively and efficiently assist the User in accessing the proper resources. The MODsocket method and system also continuously improves the delivery of marketing resources in accordance with industry best practices, even as the MODsocket system revolutionizes the industry. The MODsocket system provides the people, processes, and tools the User needs to help his/her business stand out and succeed.
[0049] In accordance with the provisions of the patent statutes, the present invention has been described in what is considered to represent its preferred embodiment. However, it should be noted that the invention can be practiced otherwise than as specifically illustrated and described without departing from its spirit or scope. | A computer program facilitates a consultation between an authorized user and a human consultant. During the consultation, the human consultant maps a user need to one or more marketing objectives. The consultant interacts with the computer program to identify one or more tactics that are relevant to accomplishing the one or more marketing objectives. The consultant or the user selects from the one or more tactics identified by the computer program to cause the computer program to identify marketing packages available to implement a selected tactic. The consultant facilitates selection of a marketing package by the authorized user to implement a selected tactic. | 6 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Divisional of copending U.S. patent application Ser. No. 09/772,800, filed on Jan. 30, 2001.
BACKGROUND
[0002] The present invention generally relates to placing images on textiles, and in particular, to the treatment of textiles for enhancing the definition of the image placed upon the textile.
[0003] Images are placed upon a substrate by various methods such as digital printing. Digital printing is the process of placing various small predetermined quantities of a colorant, known as pixels, in predetermined matrix zones of a substrate. Colorants can include dyes, pigments, polymeric colorants, or combinations thereof. Additionally, colorants can include different types and colors of dyes and/or pigments. The pixels can be placed on the substrate by various methods, such as ink jet printing. Typically, digital printing uses a limited small number of different colorants, and only one of these colorants is used for a particular pixel. Variations in colors and shades in digital printing is generally accomplished in digital printing by positioning different colored pixels in adjacent or near-by matrix zones. Although the actual color of the individual pixels is not changed, the impression to a viewer is that the area containing the different colored pixels is a color or shade that is different than any of the actual pixels in the associated area. The impression is created because the pixels are of such a small nature that the viewer cannot readily perceive the individual pixels, and perceives more of an average of the pixels.
[0004] Placing images on textiles presents various difficulties not experienced in all substrates. It has been discovered by the inventors of the present invention that, due to the nature of the material in a textile, or the construction of the textile, the color medium (such as ink) used to place the image on the textile may not fill the intended zone for the medium, may bleed outside of the intended zone, or may be absorbed into the textile substrate. If the color medium does not fill the intended zone, the image placed on the textile can lose color intensity due to the presence of the underlying textile substrate color. If the color medium is absorbed into the textile, color intensity can be lost due to at least a portion of the color medium being disposed in an area of the textile that cannot be seen, and/or by the color medium failing to fill the intended zone. If the color medium bleeds outside of the intended zone, image acuity and intensity can be impacted.
[0005] These problems are of greater concern with digital printing, where the intended zones for the color medium are smaller and closer together. Furthermore, methods to correct these problems can increase the ability of the textile substrate to lose colorant due to rubbing contact with another surface. Therefore, there is a need for textiles, textile treatments, and methods which reduce the difficulties in placing an image on textiles.
DETAILED DESCRIPTION
[0006] In one embodiment of the present invention, a coating having cationic and repellant characteristics are coated onto the surface of a textile to receive an image by processes such as digital printing. The coating can be a combination of a cationic material and a repellant finish.
[0007] Generally, the textile materials can include banner or sign fabrics, upholstery fabrics, drapery fabrics, napery fabrics, carpeting, and the like. The textile can be a woven, knitted, non-woven material, tufted materials, and the like. Woven textiles can include, but are not limited to, satin, poplin, and crepe weave textiles. In one embodiment, the textile is a woven textile, and has from about 15 to about 75 picks per inch, from about 15 to about 175 ends per inch, and can be a satin weave. Knit textiles can include, but are not limited to, circular knit, warp knit, and warp knit with a microdenier face. In one embodiment, the textile is a warp knit fabric with from about 12 to about 50 wales per inch, and from about 10 to about 60 courses per inch. Such textile materials can be formed of natural or synthetic fibers, such as polyester, nylon, wool and acrylic, including textile materials containing mixtures of such natural and synthetic fibers.
[0008] Cationic material are materials that have a positive charge. It is believed that the cationic material helps hold the color medium on the surface of the intended zone, thereby reducing any bleeding of the color medium into unintended areas or absorption of the color medium into the textile. Cationic materials that can be used for the present invention include, but are not limited to, polymeric, non-polymeric organic compounds, and metal salts. Polymeric cationic materials and non-polymeric organic cationic materials include nitrogen containing materials and phosphorus containing materials. Nitrogen containing cationic materials include, but are not limited to, primary amine (such as polyvinylamine or polyallyamine), secondary amine, tertiary amine, quaternary amine, and amines converted to cationic amines under acidic conditions. Examples of nitrogen containing cationic polymer materials include homopolymers or copolymers of cationic monomers. Cationic monomers can include diallyldimethylammonium chloride, or methacrylamidopropyltrimethyl ammonium chloride, or the like. Phosphorus containing cationic material include, but are not limited to, the phosphonium group. Examples of a phosphonium group cationic material include stearyltributyl phosphonium bromide, or the like.
[0009] Metal salts that can be used for the present invention include water soluble salts of cations from Group II, Group III, or the Transition Metals of the Periodic Table. Examples include magnesium, calcium, aluminum, zinc, and zirconium. In a preferred embodiment, the salts have an anion of a weak acid, such as acetate forming or the like.
[0010] It has been found that the use of a combination of quaternary polymer and a multivalent metal salt as the cationic coating material is particularly effective as a treatment for fabric to receive an image such as from digital printing.
[0011] Repellant finishes include fluorochemicals, silicones, resin-based finishes, waxes, wax-metal emulsions, organometallic complexes, and combinations thereof. It is believed that the repellant properties of the repellant finishes help prevent the color medium from being absorbed into the textile, and facilitates allowing the color medium to fill the entire intended zone for the color medium.
[0012] Fluorochemical repellants include chemicals that contain perfluorocarbon groups. In one embodiment, the fluorochemical repellants are the products of copolymers of perfluoroalkyl acrylates or methacrylates with other comonomers. The comonomers include esters of acrylic or methacrylic acid containing alkyl groups, alkylamide groups, or polyether groups. In one embodiment, the Fluorochemical repellants can be emulsions or solvent solutions for application to the textile material.
[0013] Silicone repellants include polymers of methyl(hydrogen)siloxane and dimethylsiloxane. In one embodiment, the silicones are an aqueous emulsion or a solvent solution for application to the textile material.
[0014] Resin-based finishes include modified melamine formaldehyde resin based finishes, and can be blended with waxes. In one embodiment, the resin-based finishes are a water soluble material such as Aerotex M3 from BF Goodrich for application to the textile material.
[0015] The image on the textile is created by a colorant. The colorant can be dyes, pigments, polymeric colorants, or a combination thereof, and can be a component of a material such as an ink. The ink can be an aqueous and/or non-aqueous solution based material, with the colorant being a dispersion or a solution therein. An example of the aqueous dispersion type ink is the DI Series (Yellow GWL, etc.) from Ciba, Inc. An example of a non-aqueous solvent type ink is the PzO Series (cyan, magenta, yellow etc.) from A.R. Monteith. Inc.
[0016] In a procedure of the present invention, the coating having cationic and repellant properties is applied to the textile and then the image is placed upon the surface of the textile having the coating thereon. In one embodiment, the coating is applied to the textile substrate in an aqueous solution. The aqueous solution can be applied to the surface of the textile to receive the image, or the entire textile can be dipped into the aqueous solution. After the aqueous coating is place on the textile, the textile is typically squeezed between rolls to remove excess aqueous solution, and then dried. The image can be placed on the textile using digital printing, such as from a digital or ink jet printer.
[0017] The present invention can be further understood with reference to the following examples:
EXAMPLES 1-6
[0018] A polyester fabric was dipped into a variety of aqueous baths of the chemical coatings listed below in Table 1. The fabric was a Sateen Weave with 152 ends per inch and 70 picks per inch. The warp yarn was a 1/70/34 polyester, warp drawn yarn. The fill yarn was a 1/150/34 textured polyester yarn. The base fabric weighed about 3.1 oz/sq. yd.
TABLE 1 AR AR AR AR % ΔE ΔE ΔE ΔE Black Black Red Red Example Chemical Formulation add-on Black Red Yellow Blue Warp Fill Warp Fill Control N/A 0% 65.6 53.8 47.5 51.5 1.3 2.3 1.3 3.3 1 15% Polycat M-30 3.2% 69.4 63.5 65.9 58.2 1 1.2 1 1.2 3% Foraperle 501 2 15% Polycat M-30 3.5% 69.5 63.8 65.6 57.3 1 1.2 1 1.2 1% Foraperle 501 3 15% Polycat M-30 3.0% 69.5 63.0 64.6 56.3 1 1.2 1 1.3 0.5% Foraperle 501 4 15% Polycat M-30 3.0% 67.8 60.6 56.7 57.8 1 1 1 1 0.5% Repearl 8025 5 35% Nalco 2010 4.3% 70.6 69.1 77.4 59.5 1 1.3 1 1.2 1% Foraperle 501 6 25% Dow Coming 4.5% 68.4 38.0 45.3 37.4 1 1.3 1 1.3 5700
[0019] In Table 1, the percentages of the chemicals listed in the Chemical Formulation column are by weight of the total aqueous bath of the chemical coatings. In the Chemical Formulation column of Table 1, Polycat M-30 is a quanternary stilbene vinyl copolymer by Peach State Labs; Foraperle 501 is a fluorochemical dispersion by Atofina; Repearl 8025 is a fluorochemical dispersion by Mitsubishi Chemical; and Nalco 2010 is a diallyidimethylammonium chloride (DADMAC) polymer by Nalco. Dow Corning 5700 listed as the Chemical Formulation in Example 6, is a 3-(trimethoxysilyl)propydimethyloctadecyl ammonium chloride by Dow Corning, and demonstrates the present invention utilizing a coating chemical having both cationic and hydrophobic properties. Another coating chemical that can be used for the present invention that have both cationic and hydrophobic properties includes melamine-formaldehyde resin.
[0020] The chemical coatings were applied in aqueous form by dipping the fabric into a water based bath of the chemicals listed in Table 1. After the fabric was coated with the aqueous solution of the chemical coatings, the coated fabric was squeezed between rolls and dried at 360 F for 2 minutes. The % of add-on is the difference between the weight of the fabric before and after the chemical coatings are applied, divided by the weight of the fabric before addition of the chemical coatings and multiplied by 100.
[0021] The coated fabric was printed with an HP 660C digital printer with a test pattern of 1 inch diameter black, red, yellow, and red dots, and 4 pt. black and red lines. The inks used were pigment based (Black), or acid dye based (red, yellow, blue).
[0022] The color of the dots was measured with a HunterLab DP-9000 colorometer. The variations in color intensity between samples and the fabric background was measured with a modification of The Engineering Society for Advancing Mobility Land Sea Air and Space Textile Test method SAE J-1885, “(R) Accelerated Exposure of Automotive Interior Trim Components Using a Controlled Irradiance Water Cooled Xenon-Arc Apparatus”. The modification of the test was that the initial measurement was on the background (or area not printed) and the final measurement was on the printed area. The color intensity, ΔE p , is generally calculated by the following equation:
Δ E p =(( L background −L printed ) 2 +( a background −a printed ) 2 +( b background −b* printed ) 2 ) 1/2
wherein ΔE p represents the difference in color between the background fabric and the fabric after printing. L, a, and b are the color coordinates; wherein L is a measure of the lightness and darkness of the colored fabric; a is a measure of the redness or greenness of the colored fabric; and b is a measure of the yellowness or blueness of the colored fabric. Greater ΔE p value result in a higher intensity of the color.
[0023] The acuity ratio (AR) was calculated by printing the black and red 4 pt. line in both warp and fill directions and measuring the greatest width that the ink wicked away from the line under a light microscope and dividing by the theoretical line width.
[0024] The results in Table 1 demonstrate the effects of changing concentration of repellant finish, type of repellant finish or cationic chemical, and total solids add-on. | A textile coated with a coating having cationic and repellant properties, thereby accepting an image thereon more readily. | 3 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates generally to devices and methods for facilitating intravenous access, and in particular to such devices and methods utilizing various combinations of vacuum, heat and tactile stimulation to dilate peripheral veins and thereby to facilitate their identification for blood sampling or cannulation. Other applications of the present invention, however, are also possible, and are within the scope of what the inventor regards as his invention.
[0003] 2. Related Background Art
[0004] Peripheral intravenous access plays an integral role in treatment of patients with both critical and non-critical conditions. It is routinely accomplished by application of a tourniquet to an extremity with enough pressure to occlude venous drainage, but not arterial inflow, thereby causing dilation of veins distal to the tourniquet. Once a dilated vessel is identified, a cannula is inserted percutaneously. Not infrequently, underlying physiologic states including, but not limited to, dehydration, shock from blood loss or redistribution of blood volume, hypothermia, and even anxiety cause peripheral vasoconstriction by neuroendocrine pathways. This vasoconstriction often impedes the normal venous dilation when a tourniquet is applied, making intravenous access problematic. At this point, medical specialists will often apply heat or tactile stimulation, or place the extremity lower than the heart in an attempt to improve peripheral blood flow and overcome vasoconstriction. More central access, with its greater inherent risk to the patient, is often needed if these efforts fail.
[0005] Various efforts have been made to ameliorate these problems. U.S. Pat. No. 4,299,219 (Norris, Jr.) relates to a device to dilate peripheral veins at the site of application of the device. Suction from the device is created by an operator-activated plunger. The utility of the device appears to be limited by at least two factors: (1) its usefulness presupposes that a target vein can be identified prior to application of the device; and (2) the device only causes a small area of venodilation, which will rapidly collapse on needle entry.
[0006] U.S. Pat. No. 4,747,409 (Silen) relates to a sleeve with heating elements used to enwrap a distal extremity for the purpose of warming, thereby enhancing arterial blood flow. This device would seem to have limited ability to counteract vasoconstriction on the venous side of the circulation.
[0007] U.S. Pat. No. 5,074,285 (Wright) relates to one of a number of known devices for applying a thermal environment to an extremity in the hope of achieving various therapeutic effects. An extremity is placed within a stocking that has pockets placed along its length. Thermal elements are then placed in one or more of the pockets, with the intent of applying heat or cold at one or more specified sites along the extremity. This device also incorporates a series of compartments placed along the length of a tubular body that encases the extremity and stocking with the purpose of applying a pressure gradient along the length of the tubular body. The sequenced pressure gradient is used primarily in treating lymphatic or venous stasis problems in extremities requiring thermal therapy.
[0008] U.S. Pat. No. 5,441,477 (Hargest) relates to an apparatus combining electrotherapy and the massaging action of a thermally energized fluidized bed for treating injured extremities. (Other patents also relate to the use of a fluidized bed for massaging a part of a body, with or without heating or cooling, e.g., U.S. Pat. No. 4,214,576 (Henley).)
[0009] U.S. Pat. No. 5,683,438 (Grahn) relates to a device that combines a heat source with a sustained vacuum to dilate superficial capillary beds with the intent of treating hypothermia.
SUMMARY OF THE PRESENT INVENTION
[0010] It is an object of the present invention to provide a device and method that enable reliable dilation of veins and their subsequent identification and access for venipuncture or the like.
[0011] According to one aspect of the present invention, this object is attained by providing a device which includes a chamber having an interior for receiving a portion of a body, and having at least one inlet for admitting a fluid into the chamber. A fluid supply is connected to the inlet to enable the fluid to be admitted into the chamber. A heater is positioned so as to be able to heat the fluid being supplied to the chamber by the fluid supply. A suction source is connected to the chamber in such manner as to enable application of suction to the interior of the chamber. The chamber may contain particulate matter such that supply of the fluid into the chamber produces a fluidized bed. The chamber preferably contains a partition or sleeve that divides the chamber into two portions, one of which receives an extremity of a patient's body while the other receives the fluid.
[0012] Another aspect of the invention is a method of vasodilation, in which a portion of a body is heated (for example, by means of a fluidized bed), and a vacuum is applied to the portion of the body for a period of time after performance of the heating step. In one embodiment, the heating step may also include massaging of the portion of the body.
[0013] These and other objects, features and advantages of the present invention will be more fully appreciated from a consideration of the following detailed description of the preferred embodiments, taken together with the accompanying drawings.
BRIEF DESCRIPTION OF THE FIGURES
[0014] [0014]FIG. 1 is a perspective view of a preferred embodiment of an apparatus according to the present invention.
[0015] [0015]FIG. 2 is a schematic view of the embodiment of FIG. 1, showing more clearly the functional relation of its components.
[0016] [0016]FIG. 3 is a cross-sectional view of a portion of the embodiment of FIG. 1.
[0017] [0017]FIG. 4 is a flowchart illustrating a method of using the embodiment of FIG. 1, in accordance with the invention.
[0018] [0018]FIG. 5 is a view, partly in section, of another preferred embodiment of an apparatus according to the present invention.
[0019] [0019]FIG. 6 is a flowchart illustrating a method of using the embodiment of FIG. 5, in accordance with the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] In the embodiment shown in FIG. 1, apparatus 100 includes a cabinet 102 mounted on a cart 104 for mobility (in the version illustrated, the cart 104 is a platform on wheels or castors). Also disposed on the cart 104 is a tubular assembly 106 , which is shown as being mounted on the side of the cabinet 102 . A control panel 108 is on the top of the cabinet 102 .
[0021] As shown in detail in FIGS. 2 and 3, the tubular assembly 106 has a cylindrical housing or outer shell 110 , and a cuff 112 of latex rubber mounted airtightly at the upper end of the housing 110 . The upper end 114 of the cuff 112 is open, and is of a size suitable for receiving a portion of a patient's body, typically an arm or a leg. The upper, free end 114 of the cuff 112 is provided with a tourniquet arrangement 116 or the like that permits the formation and maintenance of an airtight seal about the periphery of the portion of the patient's body extending into the chamber defined by the interior of the housing 110 . In the embodiment shown, the cuff 112 is attached to the cylindrical housing 110 by a clamp assembly 118 . The clamp assembly 118 also airtightly secures a tubular plastic barrier or partition 120 in the form of a sleeve, closed at its lower end 122 , which is disposed inside the cylindrical housing 110 , and open at its upper end 124 . In use, the interior of this sleeve or barrier 120 receives a portion of the patient's body.
[0022] The tubular housing 110 also may contain a mass of particulate material 126 , such as plastic or glass beads, capable of being made into a fluidized bed by the introduction of a sufficient stream of a gas. This particulate material 126 is between the tubular housing 110 and the sleeve 120 , and is separated by the latter from the open end of the housing 110 . At the bottom end of the tubular housing 110 is a fixture 128 via which a gas, such as air, can be introduced to fluidize the particulate material 126 .
[0023] In addition, the tubular housing 110 is provided in this embodiment with a suitable number of (one or more) one-way ventholes or valves 130 , which can advantageously be perforations in the sleeve 120 , each covered with its own small flap of material (which may advantageously be similar or identical to the material of the sleeve itself). These valves permit fluid to leave the tubular housing 110 during fluidization of the particulate matter 126 .
[0024] As can be seen from FIG. 2, the gas supply fixture 128 at the bottom of the tubular housing 110 is connected to both a blower and a vacuum pump. (These can be the same element 132 , as illustrated, since neither the quantity or force of the stream of blown air, nor the suction required to operate the apparatus in the intended manner, is particularly great, and it is not necessary to produce a vacuum at the same time as a stream of blown air is being provided; even though a single pneumatic unit of this type is shown, and is within the scope of the invention, however, reference will be made herein to a “blower” and a “vacuum pump”, for simplicity.) When the blower 132 is operating to supply air to the tubular housing 110 to fluidize the particulate matter 126 , the control unit 134 receives a signal from a heat sensor, preferably a thermistor (not shown), located at an appropriate position, and uses a feedback loop to control a heating element 136 located in the gas supply line 138 leading from the blower 132 to the tubular housing 110 , to maintain the blown air at a desired temperature. Preferably, this temperature can be selected by the physician within some limits.
[0025] The operation of this apparatus according to the method of the present invention is as follows.
[0026] A portion of a patient's body, such as an arm or a leg, is inserted through the open end 114 of the cuff 112 into the interior of the sleeve 120 , and the tourniquet assembly 116 is used to seal the cuff 112 airtightly against the patient's skin. The blower 132 is actuated, as is the heating element 136 in the gas supply line 138 , thus providing a flow of warmed gas (air, in the embodiment of FIG. 1) into the tubular housing 110 . This supply of gas is delivered under conditions suitable to fluidize the particulate material 126 (if any) in the tubular housing 110 , producing (in such case) a fluidized bed in the latter. Motion of the particles in the fluidized bed is transmitted through the sleeve 120 to the patient's skin, providing a massaging action to the latter (in the absence of particulate material, there is simply a pressure on the skin due to the inflow of the gas). At the same time, the warmth of the gas heats the patient's limb.
[0027] After a predetermined length of time, the control unit 134 turns off both the heating element 136 and the blower 132 , and actuates the vacuum pump 132 . (Where, as shown, the blower and vacuum pump are the same element 132 , this action involves simply the deactivation of the heating element 136 and the reversal of direction of the action of the pneumatic unit 132 ). A weak vacuum is then drawn on the interior of the tubular housing 110 . This suction forces the one-way valve(s) 130 closed. Because of this, and because the patient's limb is airtightly sealed in the opening of the cuff by the tourniquet assembly 116 , the air pressure in the interior of the sleeve 120 is also reduced below ambient atmospheric pressure, thus applying a mild suction to the patient's skin. The fluidized bed action (if provided) suffices to drive some air our through the cuff 112 even through the otherwise airtight seal. (It is nonetheless within the scope of the invention for the sleeve 120 to be elastic enough to distend in response to the drop in pressure, rather than air being forced out through the seal.) The inventor has found that this combination of mild pressurization with heating, followed by mild suction, produces an advantageous and unexpectedly effective vasodilation in the portion of the patient's body so treated. In the case where a fluidized bed is used, the massaging action also contributes to this effect.
[0028] The exact length of time for each phase can be controlled automatically, or can be varied by the attending physician as deemed appropriate for the particular patient. A time of a few minutes for each phase may be appropriate. The air may usefully be heated to about 102-104° F. during the heating and massaging phase, and the vacuum drawn during the following phase may be on the order of 2 psi, although this value may be suitably varied by as much as 50% in either direction.
[0029] One manner of operation of the embodiment of FIGS. 1 - 3 is illustrated in the flowchart of FIG. 4. As is shown there, in step S 101 , the portion of the patient's body to be treated (for example, an arm) is placed in the chamber inside the sleeve 120 , and an airtight seal between the cuff 112 and the arm is effected. Then, in step S 102 , the heater 136 and the blower 132 are activated, resulting in the fluidization of the particles 126 (if such are provided) in the housing 110 , and in the delivery of both pressure and heat to the arm, with a massaging effect if particles 126 are used. After the passage of a predetermined amount of time during which the arm is subjected to this action, the heater 136 is turned off and the direction of action of the blower 132 is reversed (step S 103 ), to pull a slight vacuum on the air in the housing 110 . Since this reduces the air pressure in the sleeve 120 as well, the arm is also subjected to the slight vacuum. This condition is also maintained for a predetermined length of time, which may or may not be the same length as the duration of the warming treatment, and is then terminated. After this, the patient's arm may be withdrawn from the apparatus to see if an appropriate site for venipuncture now exists. If the attending physician deems it appropriate, the process, including steps S 101 -S 103 , may be repeated.
[0030] [0030]FIG. 5 illustrates a second preferred embodiment 200 of the invention, in which the fluidized bed optionally provided in of the first embodiment 100 is eliminated. In this embodiment, a rigid or semi-rigid outer shell 202 is provided, which contains a flexible, heat-permeable inner liner 204 and has a flexible flange 206 at one end. Gaskets (not shown) attach the flange 206 and the inner liner 204 airtightly to the shell 202 . The shell 202 is sufficiently rigid to maintain its shape even in the presence of a small pressure differential across its thickness, such as a differential of 2 psi. The inner liner 204 , in contrast, is preferably so light that it will collapse under any significant pressure differential at all (many plastics may be suitable for use as the liner).
[0031] The shell 202 has an inlet 208 and an outlet 210 for a fluid, which in this preferred embodiment is water. A pressure-relief valve 212 is provided in one wall of the shell 202 , and is constructed to open to allow ambient air into the shell 202 whenever the pressure inside the shell 20 is less than ambient pressure by more than a predetermined amount (say, 80 mm of Hg). Also, toward the top of the shell 202 is provided a fluid-level detector 214 , to detect when the level of water in the shell 202 has reached the position of the detector 214 , and to send a signal to that effect to a control unit 216 in response to such detection. One simple construction (not shown) of such a detector may be a wire cage provided on the interior of the shell 202 , with an electrically conductive float that, upon the water level rising sufficiently, moves into conductive contact with two electrical terminals or contacts to complete an electrical circuit, thereby to allow emission of an electrical signal to the control unit. Other constructions, within the reach of those of ordinary skill, can be used instead. The power for such signal may be provided either by battery at the shell 202 , or be supplied from elsewhere.
[0032] A reservoir 218 of water is provided, the interior of which communicates via two lines 220 and 222 with two pumps 224 and 226 , which may preferably be roller pumps. Each of these pumps 224 and 226 communicates via a respective second line 228 and 230 with either the inlet 208 or the outlet 210 , respectively, at the shell 202 . Each pump 224 and 226 is controlled by a respective pump regulator 232 and 234 .
[0033] The control unit 216 is preferably located in a cabinet 236 together with the pumps 224 and 226 and the water reservoir 218 . Also, a heating device 238 is provided in the reservoir 218 , under control of a temperature regulator such as a thermostat 240 , to maintain the contents of the reservoir 218 at a desired temperature.
[0034] In operation, the second embodiment 200 of the invention is used as follows. First, the portion of the patient's body to be treated, for example, an arm, is placed through the flexible flange 206 and into the flexible liner 204 (step S 201 ), and an airtight seal against the skin is achieved. The inflow pump 224 is then started, under control of the control unit 216 (step S 202 ). (More exactly, the operator actuates an external switch, responsive to which the control unit 216 emits necessary signals to activate the inflow pump 224 .) Preheated water from the reservoir 218 is pumped through the inflow conduit 228 , through the inlet 208 and into the space 242 between the shell 202 and the liner 204 . Ordinarily, at the beginning of the process, the liner 204 should preferably lie very close against the inner wall of the shell 202 , and consequently, the water is being pumped into a space 242 containing little or no air. As this occurs, the pressure due to the presence of the heated water raises the air pressure in the liner 204 sufficiently to force air out of the liner 204 , passing between the arm and the flange 206 (naturally, the seal of the flange against the patient's skin must not be so tight as to prevent this). Alternatively, if desired, a one-way valve could be provided for this purpose, but is not believed to be necessary as a practical matter. As the water rises, it eventually activates the level detector 214 , which emits a signal that causes the control unit 216 to activate the outflow pump 226 as well (step S 203 ).
[0035] Thus, in this portion of the process, the arm is subjected to a slightly elevated pressure, and is warmed by the heated water.
[0036] Once both pumps 224 and 226 are working, the water is pumped in and out of the shell 202 at a constant rate, maintaining the arm or other portion of the body in a steady condition for a predetermined time, under control of the control unit 216 . (Alternatively, the duration of this portion of the process could be left to manual control by the operator.) Then, the inflow pump 224 is stopped, while the outflow pump 226 continues to operate, and evacuates the water from between the shell 202 and the liner 204 (step S 204 ). This evacuation of the water reduces the pressure of the air remaining inside the liner 204 . The relief valve 212 , however, ensures that the pressure inside the shell 202 (and inside the liner 204 ) does not fall more than a preset amount below ambient atmospheric pressure. In this preferred embodiment, this preset amount or limit is equal to 80 mm of Hg.
[0037] This reduction of pressure also results in the flexible flange 206 being forced, by atmospheric pressure, still more tightly against the arm. (If desired, a strap with Velcro (TM) or other fasteners can be used to make this seal still tighter.) At the proper time, the outflow pump 226 is stopped (step S 205 ). Again, this time can be preset in the control unit 216 , or the operation of the outflow pump 226 can be stopped by the operator manually. A tourniquet is now placed on the arm, the seal of the flange 206 around the arm is broken, and the patient's arm is removed for venipuncture, intravenous access or the like.
[0038] Many variations of the foregoing methods and apparatus are possible without departing from the scope of what the inventors consider to be their invention, broadly construed. For instance, in the first embodiment, instead of one-way valves on the surface of the sleeve or barrier, such valves may instead be provided in a portion (or all) of the lateral surface of the tubular housing. In such case, the heating of the patient's skin is achieved by the conduction of heat through the material of the sleeve, whereas in the arrangement shown, the warming of the skin is partly the result of convection. Also, in all embodiments, the sleeve that receives the limb or other portion of the patient's body may be disposable if for any reason that is desirable. Again, while it is contemplated to provide such sleeve (whether disposable or not), the benefits of the invention may be derived even if no such sleeve is present (at least where no particulate material is used to generate a fluidized bed).
[0039] Again, particularly (but not only) in the second embodiment, the inflow pump could be controlled in such fashion as to provide a pulsating action, to provide the limb with a massaging action, as in the first embodiment. Such pulsation could be delivered during part or all of the treatment.
[0040] Also, the arrangement of the components on and in the cart 104 may be varied in any convenient manner. One useful variation may be to mount the tubular housing such that its position and orientation can be varied according to convenience. Again, the apparatus need not be mounted on a cart at all. For example, it could be mounted on the wall of a room, or mounted to the interior of an ambulance or the like, or could be constructed to be detachably mountable to a bed, or could be provided without a permanent mounting.
[0041] It is also to be understood that the method of the invention, although described above with reference to two preferred embodiments of the apparatus of the invention, could be performed with other, quite different apparatus. Such use of other apparatus to perform the method of the invention, as set out hereafter in the claims, is also within the scope of the invention, with whatever apparatus it may be performed.
[0042] As discussed above, with regard to the first embodiment, the blower and suction unit can be separate units or a combined unit having both functions. As a further variation, it is contemplated to use separate units for the blower and the suction source, and in particular to use as the blower a unit such as those conventionally used to provide heated air to a patient covered with a plastic blanket (such arrangements are used conventionally to prevent hypothermia during or after surgery, for example). In this variation, an adapter is provided to fit such blower, the suction source and the tubular assembly containing the chamber to which both suction and blown air are applied. One example of a structure for such an adapter might be a three-way connector made of polyvinyl chloride tubing, or the like. In this variation, or embodiment, also, the tubular assembly can if desired contain particulate matter, so as to utilize a fluidized bed as in the first embodiment, or the particulate material can be omitted. In any event, the successive steps involving the supply of heated fluid (in this case, air) to the chamber followed by application of suction after termination of the supply of heated fluid, may be performed as with the other structures described herein.
[0043] Again, while it is most preferably conceived that the invention will be used by insertion of a limb of a patient into the sleeve, the apparatus may be constructed on any scale desired. For example, the sleeve could be constructed large enough to receive the entire lower portion of a patient's body, including part or even the entire torso, and used to stimulate blood flow over a large portion of the body.
[0044] Finally, while it is contemplated that the present invention will be used with human patients, veterinary use is also within the scope of the invention.
[0045] While the present invention has been described with specific reference to the presently preferred embodiments and variations thereof, which constitute the inventor's best contemplated mode of practicing the invention, many additional modifications and variations thereof will now be readily apparent to those of skill in the art. Accordingly, it is to be understood that the scope of the present invention is to be limited, not by the details of the foregoing illustrative embodiments, but only by the terms of the appended claims. | A device suitable for vein dilation includes a chamber having an interior for receiving a portion of a body, and having at least one inlet for admitting a fluid into the chamber. A fluid supply is connected to that inlet to enable the fluid to be admitted into the chamber. A suction source is connected to the chamber such as to be able to apply suction to the interior of the chamber, and a heater is positioned to be able to heat the fluid being supplied to the chamber by the fluid supply. In use, a portion of a body may be massaged and heated (one possibility is to use a fluidized bed formed in the chamber while the body portion is in the chamber), and a vacuum is applied to the portion of the body after performance of the massaging and heating step. Alternatively, the massaging may be omitted, and the body portion heated first and then subjected to a period of suction. | 0 |
BACKGROUND OF THE INVENTION
This invention is concerned with an apparatus for laser welding of metals in a pressurized atmosphere.
Oxide Dispersion Strengthened (ODS) alloys, such as those described in U.S. Pat. No. 3,992,161, are generally produced by powder metallurgy techniques. The powdered metals used for mechanically alloyed ODS alloys, as well as a number of other alloys, can be prepared by atomizing a molten metal stream with high velocity jets of argon gas. Some of the argon used for atomization, as well as argon which may be incorporated during a mechanical alloying operation performed in an argon atmosphere, can be entrapped in the powdered metal and retained, albeit in small quantities, in consolidated and sintered shapes prepared from the ODS alloys. Attempts to join ODS alloys by welding have been hampered by gross porosity resulting from entrapped argon.
An additional welding problem resides in the agglomeration and slagging-off of the dispersoid without which the ODS alloy weld deposits are severely limited in elevated temperature strength. Attempts to weld the ODS alloys with a variety of well known fusion welding techniques have generally been unsuccessful in overcoming the dispersoid agglomeration problem.
The advent of LASER (Light Amplification by Stimulated Emission of Radiation) devices useful for welding provides an advantagous tool for attacking the problems inherent in joining ODS alloys. Because a laser beam provides an intense source of radiation in a small area, rapid melting occurs and under appropriate conditions can be followed by rapid solidification so that the dispersoid will have insufficient time to agglomerate and/or slagg off (e.g., melting and solidification during laser welding can occur in 8 milliseconds). Thus, under appropriate welding conditions, it is theoretically possible for the dispersoid to be retained within the weld deposit and to provide the desired strengthening effect during elevated temperature service. However, the problem of argon induced porosity is not avoided by using known laser welding techniques, similar to those described in U.S. Pat. Nos. 3,824,368 and 4,000,392, where inert gas substantially at atmospheric pressure and subject to ingestion of air is used to shield the workpiece.
Porosity, for example, of the type attributed to the presence of argon in ODS alloys, can be largely suppressed by welding in a pressurized atmosphere containing gas of essentially the same composition as that responsible for the porosity, e.g., argon. However, attempts to use a laser beam for welding in a pressurized chamber containing such an argon atmosphere have been thwarted by ionization of the still argon and the formation of a soot-like buildup in the welding chamber which absorb laser power and interrupt welding continuity. In addition, a stream of what is believed to be ionized metal particles travels along the laser beam, impinging on the inside surface of the light transmitting means (sight glass necessary for transmission of the laser beam into the chamber). This action causes absorption of laser energy as well as severe thermal stress and rapid breakage or even melting of the light transmitting means.
The latter problem appears, in many respects, to be unique to laser welding within a chamber, although laserinduced debris problems have been described in several patents dealing with laser cutting and drilling as represented by U.S. Pat. Nos. 3,626,141, 3,866,398 and 4,027,137.
SUMMARY OF THE INVENTION
It has now been discovered that sound laser welds can be prepared in workpieces enclosed within a gas tight vessel by introducing a stream of an appropriate gas into the vessel and directing this gas stream to impinge the surface of a light transmitting means while intersecting the laser beam. The gas stream deflects ionized particles moving countercurrent to the laser beam so that the particles substantially avoid contact with the light transmitting means. In addition, the gas stream cools the light transmitting means. Simultaneously to gas inflow, spent gas is withdrawn to clear the vessel of soot and welding debris. The combined actions of the inflowing gas stream and the exhaust provide improved laser beam efficiency and substantially avoid clouding and breakage or melting of the light transmitting means thereby allowing laser welding within a pressurized environment, particularly of ODS alloys under conditions which substantially avoid porosity. In addition, the apparatus and method of the present invention are generally useful for the laser welding of metals where it is essential that laser welding be performed in a specific gas atmosphere at high as well as sub-atomospheric pressures. The apparatus provides a controllably pure gaseous environment for welding wherein both sides of the weld bead and the surrounding metal are protected. According to the present invention, contamination by specific gaseous ingredients also can be avoided (e.g., oxides and nitrides) and conditions for favorable gas-metal reactions provided (e.g., carbides and nitrides) if desired.
Generally speaking, the present invention is an apparatus for welding with a laser beam comprising: a gas tight vessel enclosing a workpiece to be welded; a light transmitting means for passage of the laser beam into the vessel, the light transmitting means positioned to permit impingement of the laser beam on the workpiece; a gas inlet means for introducing a gas stream into the vessel, the gas inlet means positioned to impinge the gas stream on the light transmitting means and intersect the laser beam; and a gas exhaust means for the removal of gas from the vessel. Preferably, the gas exhaust means is located adjacent to the workpiece. With the preferred arrangement, fumes from the welding operation are extracted from the vessel to provide minimal interference with the laser beam and to maintain cleanliness within the vessel.
BRIEF DESCRIPTION OF THE DRAWING
The FIGURE is a schematic cross section of a preferred embodiment of the apparatus of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the figure, the gas tight vessel 20 is provided with a light transmitting member 22 (preferably located opposite and aligned with the workpiece) prepared from a suitable material (e.g., a borosilicate glass, a methyl methacrylate plastic, germanium, etc.) that is transparent to light having a wave length less than about 11 microns and preferably less than about 2 microns. An appropriate sealing means 23 is used to seal the light transmitting means to the gas tight vessel (e.g., by bolting a metal ring to compress a rubber O-ring between the vessel and the light transmitting means). The laser beam 24 passes through the light transmitting means and a suitable gas within the vessel (e.g., an inert gas such as argon, helium, etc.) to intersect the workpiece 26 contained within the gas tight vessel. The workpiece represents the metal being welded and in the simple configuration shown is representative of a square butt joint between two rectangular pieces of sheet metal. The pieces of metal being joined are generally held down by a clamping means (not shown) to maintain alignment and to limit distortion during welding.
The workpiece is depicted atop a backing plate 28 having a groove 30. The backing plate is generally prepared from copper, or it can be prepared from other metals such as silver or aluminum that provide high reflective properties to the laser beam as well as excellent heat conducting properties. The backing plate serves to protect the region of the gas tight vessel directly in line with the laser beam and also directs weld solidification from the bottom toward the top surface of the workpiece. The groove 30 in the backing plate allows penetration by the laser beam and flow of molten metal at the base of the joint.
A gas inlet means 32 is positioned through a wall of the gas tight vessel adjacent to the light transmitting means. An inert gas introduced through the gas inlet means, in addition to the function of substantially avoiding ionization of the gas stream, strikes the light transmitting means in the region through which the laser beam is transmitted and serves to remove heat from the light transmitting means such as that from the welding process and heat generated by interaction of the laser and the light transmitting means or any metal vapor deposited on the surface of the light transmitting means. The gas flow is also directed to intersect the path of the laser beam. Metal vapors ionized by the laser beam traveling toward the laser beam source are deflected by the stream of inert gas. Deflection of the ionized particles substantially avoids deposition of the particles on the light transmitting means with consequent clouding of this means. Such clouding will cause a substantial decrease in the efficiency with which the laser beam is transmitted. Also, because of the buildup of a metal layer on the surface of the light transmitting means, heat is generated within this means due to interaction with the laser beam. Such heating results in melting of transparent plastics and high thermal stresses which can lead to breakage of glass members with resultant weld stoppage. As will be recognized by those skilled in the art, the effectiveness of the gas stream is dependent on not only the degree of turbulence provided but on the physical properties of the gas used, as well as the positioning and shape of the gas inlet means and vessel. Gas flow rates as low as about 0.3 m 3 /hr. are useful with argon.
A gas exhaust means 34 is provided to allow the inert gas, along with metal vapor and debris formed during welding, to be exhausted from the gas tight vessel. It is preferred to position the gas exhaust means in the immediate vicinity of the workpiece so that fumes generated during the welding operation are removed from the gas tight vessel by the shortest route. That is, the ionized particles that travel along the laser beam toward the light transmitting member represent only a portion of the fumes generated during the welding operation. Since these fumes as well as nonionized fumes would reside in the chamber if not exhausted in the vicinity of the welding operation, they would serve as a filter and act to reduce the efficiency of the laser beam. The gas exhaust means can be any convenient means for providing lower pressure outside the gas tight vessel (e.g., regulator, bubbler, partial vacuum, controlled leak, etc.). It is most preferred to have the shape of the gas exhaust means conform to a particular weld configuration so that it is aligned with and runs the length of the weld. Such a paradromic arrangement most effectively removes fumes during the welding operation.
In the general case of preparing a weld bead requiring relative motion between the workpiece and the laser beam, the chamber can be moved and a stationary laser beam used. Alternatively, the chamber can be maintained stationary and the laser beam moved to prepare the weld.
To illustrate the process of this invention, two pieces of an ODS sheet alloy were joined by laser welding in argon under a pressure of about 50 N/mm 2 . The ODS alloy known as MA956E and available from Huntington Alloys, Inc. nominally contained, in weight percent: 20% Cr, 4% Al, 0.5% Ti, 0.5% Y 2 O 3 , Bal. Fe. Representative pieces of this alloy, 1 mm thick by 38 mm wide by 100 mm long, were butted together along a 38 mm edge. The pieces were clamped to a copper backing plate within a 850 cm 3 vessel representative of a preferred embodiment of the present invention. The vessel was sealed by tightening 8 screws to compress a rubber O-ring placed between a clear methyl methacrylate light transmitting means and the vessel. Argon was introduced to the vessel at a pressure of about 0.50 N/mm 2 at an estimated flow rate of 0.6 M 3 /hr and exhausted through the gas exhaust means at a rate sufficient to maintain the internal argon gas pressure.
A Sylvania 1610 laser having a neodymium doped Yttrium Aluminum Garnet providing light of 1.06 micron wave length was used to prepare the welded joint. The laser device was operated at an energy input of 16 joules/pulse using 10 pulses per second. The vessel containing the pieces to be welded was moved past the stationary laser beam at a travel speed of 7.5 cm/min. The angle of the beam was 85° to the horizontal surface of the workpiece. Continuous welding was achieved under the foregoing conditions and a sound, 38 mm long, weld obtained. By way of contrast, when the chamber was operated at 0.50 N/mm 2 internal pressure with the gas exhaust means closed so that there was no flow of gas from the gas inlet means to intersect the laser beam and to strike the light transmitting means, the welding operation effectively ceased after traveling about 1 mm due to fumes within the chamber and clouding of the light transmitting means. As a result of two attempts to weld under these conditions with the production of about a 2 mm length of weld, the plastic light transmitting means exhibited partial melting and was not useful for further trials.
The apparatus of the present invention is generally suited to welding with laser beams having wave lengths of less than about 11 microns. Any solid light transmitting means can be used as long as it is transparent to the incident laser radiation. To illustrate, the CO 2 laser, which emits coherent light radiation in the far infrared region having a wavelength of 10.6 microns, can be used when the vessel is fitted with a light transmitting means transparent to such light (e.g., zinc selenide, germanium, a barium fluoride, tellurium, etc., sight glasses).
A laser having a wave length less than about 2 microns, such as a pulsed Nd YAG laser of 1.06 micron wave length, is preferred since it can be transmitted through more common transparent materials (e.g., glasses and plastics).
Although the present invention has been described in conjunction with preferred embodiments, it is to be understood that modifications and variations may be resorted to without departing from the spirit and scope of the invention, as those skilled in the art will readily understand. Such modifications and variations are considered to be within the purview and scope of the invention and appended claims. | Apparatus and method for laser welding in a controllably pure gaseous environment at sub-atmospheric as well as high pressures. A workpiece to be welded is contained within a vessel having a light transmitting means which allows passage of a laser beam into the vessel. A gas stream is introduced to the vessel through a gas inlet means and positioned so that the stream deflects ionized particles from impinging on the light transmitting means. The gas stream simultaneously serves to cool the light transmitting means. Weld debris and spent gas are exhausted through a gas exhaust means which preferably is located adjacent to the workpiece. The apparatus is particularly suited to the laser welding of oxide dispersion strengthened alloys. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to devices for cleaning air.
More particularly, the present invention relates to air cleaning devices in close association with toilets, for removing malodor from the air.
In a further and more specific aspect, the present invention concerns retrofitting an air cleaning apparatus onto a toilet for cleaning malodorous air within the toilet bowl.
2. The Prior Art
From early times, people have considered their excremental functions private, and accordingly, have moved this event in from the open outdoors, to small closed rooms. While private, these small rooms lack the cleansing breezes of the more natural setting. Attempts have been made to compensate for this deficiency by providing windows, ventilating fans and the like. It has also been discovered that sulfur tends to counteract the offensive odor. Capitalizing on this phenomena, methods have been developed employing sulfur. Some of the simpler methods include lighting matches, candles, and even firing cap guns, although this would seem to draw unnecessary attention to the problem.
While effective, these techniques are not always possible. Many times, the toilets are placed with no access to the outside. In these situations, ducting is required to exchange fresh air with the tainted air. This can be expensive and the ventilation may be slow since the offensive odor is diffused throughout the room and generally evacuated through a small duct. This is less than ideal, since persons in the room will be subjected to the offensive odors for prolonged periods of time. Other situations which do not permit open windows or the use of matches, is in the very small rest rooms of airplanes. Obviously windows cannot be opened, and due to recent regulations, matches cannot be used. Furthermore, the odoriferous air cannot simply be vented outside the aircraft, and certainly cannot be vented into the passenger compartment.
To overcome the problems associated with venting the closed rooms, commonly referred to as bathrooms, containing the toilet, devices directly associated with the toilet have been developed which filter the malodor from the air. Typically, many of the various devices require extensive modifications to be made to the toilet, or a toilet constructed to specification in order to remove the obnoxious air. These modifications include specially constructed toilet seats with air passages, lids and/or bowls.
After the foul air has been drawn from the bowl, it is then necessary to provide treatment devices packaged in a manner which will not detract from the decor of the bathroom. No matter how attractively the exhaust and deodorizing devices are housed, they remain a distraction and are often a nuisance. Generally, these devices are not esthetically pleasing, being large bulky and positioned on the floor next to the toilet. These devices, so placed are tasteless and detract from the overall decor of a bathroom as well being obstructive. Many require an electrical outlet as a power source, which may or may not be conveniently to hand.
It would be highly advantageous, therefore, to remedy the foregoing and other deficiencies inherent in the prior art.
Accordingly, it is an object of the present invention to provide an improved ventilated and deodorized toilet.
Another object of the present invention is to provide a new and improved apparatus for ventilating and deodorizing a toilet.
And another object of the present invention is to provide a ventilating and deodorizing apparatus which can be retrofitted onto a toilet.
Still another object of the present invention is to provide a ventilating and deodorizing apparatus which is adjustable to allow adaptation to substantially any toilet.
Yet another object of the present invention is to provide a ventilating and deodorizing apparatus which may be mounted to a toilet so as to be substantially unnoticeable.
Yet still another object of the present invention is to provide a self contained toilet ventilating and deodorizing apparatus.
A further object of the present invention is to provide a ventilating and deodorizing apparatus which prevents substantially all of the obnoxious odors from escaping the toilet.
And a further object of the present invention is to provide a ventilating and deodorizing apparatus which is easy to install and to maintain.
Yet a further object of the present invention is to provide a ventilating and deodorizing apparatus which is self contained.
And yet a further object of the present invention is to provide a reliable and relatively inexpensive ventilating and deodorizing apparatus for toilets.
SUMMARY OF THE INVENTION
Briefly, to achieve the desired objects of the present invention in accordance with a preferred embodiment thereof, provided is an odor collector mountable on a toilet bowl, for extracting air from the toilet bowl, a filter assembly for deodorizing the air extracted from the toilet bowl, and a neck adjustably coupling the filter assembly to the odor collector, with the odor collector and the neck supporting the filter assembly adjacent the toilet bowl. Further provided is a switch means carried by the odor collector for activating the filter assembly, a power source for supplying power to the assembly, and a power circuit coupling the power source to the filter assembly and the switch means.
More specifically, the odor collector includes a base attachable to the toilet bowl, an air intake carried by the base and positionable adjacent an interior of the toilet bowl, and a sleeve having an open end, carried by the base in gaseous communication with the air intake. The filter assembly includes an air duct having an inlet, an impeller assembly for providing air flow through the apparatus, the air duct is coupled to the filter assembly, and a filter is carried between the impeller assembly and the air duct. The neck has a first end removably and slidably received through the open end of the sleeve, and a second end coupled to the inlet of the air duct.
In accordance with a preferred embodiment thereof, the impeller assembly includes a housing having an inlet and an outlet, coupled to the air duct with the inlet in gaseous communication with an outlet of the air duct. A fan is carried within the housing for producing an air flow through the apparatus, and actuator means for rotating said fan, is carried within the housing. A socket extends from the housing about the inlet, for receiving the filter and for coupling the housing to the air duct.
Further in accordance with an embodiment thereof, the switch means includes a pressure switch carried by the base within a switch housing and covered by a cap over the switch housing and engaging the switch. The pressure switch includes a first contact member, a second contact member, a resilient member separating the first contact member from the second contact member, and a bridging member which couples the first contact member to the second contact member upon compression of the resilient member.
In yet a more specific embodiment, the power circuit includes internal leads, extending from the actuator means, internally to a battery case, and through the air duct, the neck and the odor collector, to the switch means. A contact assembly is mounted within the sleeve, electrically coupled to the switch and corresponding contacts are mounted on the neck, engagable and disengagable with the contact assembly. The corresponding contacts engage the contact assembly over an extended range, permitting inward and outward adjustments of the neck within the sleeve while maintaining electrical contact. The power circuit further includes a contact carried by the air duct and a corresponding contact carried by the housing of the impeller assembly, engagable and disengagable with the contact carried by the air duct.
In a further, more specific aspect, the power source includes a battery case containing a battery. The battery case is removably mountable to the housing of the impeller assembly by mounting brackets serving as contacts between the battery case and the impeller assembly.
The apparatus of the present invention may also include a filter assembly housing having an inlet, an outlet, and an access port. The outlet of the air duct is coupled to the inlet of the filter assembly housing. The filter assembly housing carries the impeller assembly with the socket engaging the outlet of the air duct. The filter assembly housing also carries the power source.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and further and more specific objects and advantages of the instant invention will become readily apparent to those skilled in the art from the following detailed description of a preferred embodiment thereof, taken in conjunction with the drawings, in which:
FIG. 1 is a partial perspective view, showing a toilet with the lid in a raised position, and a toilet ventilating apparatus constructed in accordance with the teachings of the present invention, mounted thereon;
FIG. 2 is a partial exploded perspective view, illustrating how the toilet ventilating apparatus is mounted on a toilet;
FIG. 3 is a partial top plan illustrating the adjustability of the toilet ventilating apparatus;
FIG. 4 is a partial side plan of the toilet and the toilet ventilating apparatus;
FIG. 5 is a partially cut-away perspective view of an inverted odor collector;
FIG. 6 is an enlarged cross sectional view of a portion of the odor collector of FIG. 5, showing inset wires;
FIG. 7 is an enlarged cut-away view of a portion of the odor collector of FIG. 5, illustrating a contact assembly;
FIG. 8 is a cross-sectional view of the odor collector with a neck of a filter assembly inserted therein;
FIG. 9 is an exploded perspective view of a switch assembly;
FIG. 10 is a cross-sectional view of the switch of FIG. 9 taken along line 10--10 of FIG. 2;
FIG. 11 is a partial cut-away perspective view of the neck of the filter assembly;
FIG. 12 is a cross-sectional side view of the toilet ventilating apparatus, showing air flow directions;
FIG. 13 is a sectional view taken along line 13--13 of FIG. 12;
FIG. 14 is a cross-sectional side view of the filter assembly taken along line 14--14 of FIG. 12;
FIG. 15 is an exploded perspective view, showing the filter assembly;
FIG. 16 is a partial cut-away view of the filter assembly and battery case;
FIG. 17 is a partial view illustrating electrical contact between a impeller assembly and an the air duct;
FIG. 18 is a cross-sectional view of the battery case;
FIG. 19 is a partial perspective view illustrating a first electrical and mechanical coupling between the battery case and the impeller assembly;
FIG. 20 is a partial perspective view illustrating a second electrical and mechanical coupling between the battery case and the impeller assembly;
FIG. 21 is a circuit diagram of the toilet ventilating apparatus;
FIG. 22 is a top plan view of the odor collector;
FIG. 23 is a top plan view of an alternate odor collector;
FIG. 24 if a cross-sectional view taken along line 24--24 of FIG. 23;
FIG. 25 is a partial exploded view of an alternate toilet ventilating apparatus constructed in accordance with the teachings of the present invention;
FIG. 26 is a partial cut-away side view of the toilet ventilating apparatus of FIG. 25, illustrating a battery compartment;
FIG. 27 is an exploded perspective view of a switch assembly;
FIG. 28 is a cross-sectional view of the switch illustrated in FIG. 27;
FIG. 29 is a partial cross-sectional view of the top of the battery compartment of FIG. 26;
FIG. 30 is a partial cross-sectional view of the bottom of the battery compartment of FIG. 26;
FIG. 31 is a perspective view illustrating an alternate neck;
FIG. 32 is a cross-sectional view taken along line 32--32 of FIG. 31;
FIG. 33 is a partial perspective view, showing a toilet with the lid in a raised position, and an alternate embodiment of a toilet ventilating apparatus constructed in accordance with the teachings of the present invention, mounted thereon;
FIG. 34 is a partial exploded perspective view, illustrating how the toilet ventilating apparatus of FIG. 33 is mounted on a toilet;
FIG. 35 is a partial top plan illustrating the adjustability of the toilet ventilating apparatus;
FIG. 36 is a partial side plan of the toilet and the toilet ventilating apparatus;
FIG. 37 is a partially cut-away inverted perspective view of an alternate embodiment of an odor collector;
FIG. 38 is a sectional view taken along line 38--38 of FIG. 37;
FIG. 39 is an enlarged cut-away view of a portion of the odor collector of FIG. 37, illustrating a contact assembly;
FIG. 40 is a cross-sectional view of the contact between the odor collector and the neck of a filter assembly inserted therein;
FIG. 41 is a cross-sectional view of an alternate embodiment of a switch assembly;
FIG. 42 is a partial cut-away perspective view of the neck of the filter assembly;
FIG. 43 is a partial sectional view of the sliding engagement between the neck and the sleeve;
FIG. 44 is a cross-sectional view taken along line 44--44 of FIG. 43;
FIG. 45 is an exploded perspective view of the filter assembly;
FIG. 46 is a sectional view illustrating means for securing the battery case within the housing of filter assembly;
FIG. 47 is a cross-sectional side view of the alternate toilet ventilation apparatus of FIGS. 33-46;
FIG. 48 is a partial sectional view of the impeller assembly;
FIG. 49 is a sectional view taken along line 49--49 of FIG. 47;
FIG. 50 is a perspective view illustrating the housing of the filter assembly; and
FIG. 51 is a circuit diagram of the alternate embodiment of the toilet ventilating apparatus.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Turning now to the drawings in which like reference characters indicate corresponding elements throughout the several views, attention is first directed to FIG. 1 which illustrates a toilet generally designated 10, onto which a toilet ventilating and deodorizing apparatus 12 is mounted. Toilet 10 may be substantially any toilet, and includes a base 13 supporting a toilet bowl 14 having a front 15 and back 17. Front 15 and back 17 of toilet 10 will provide directional reference throughout the ensuing descriptions. A toilet seat 18 and lid 19 are coupled to a top surface 20 of toilet bowl 14 by hinges at back 17 of toilet bowl 14. This hinge arrangement permits seat 18 and lid 19 to be lowered to a horizontal position with respect to top surface 20 of toilet bowl 14 or raised to an upright position with respect to top surface 20. The movement of seat 18 and lid 19 may be accomplished independently. A water tank 22 having a front surface 23, extends upward adjacent back 17 of toilet bowl 14.
Still referring to FIG. 1, toilet ventilating and deodorizing apparatus 12 includes an odor collector 24 mounted on top surface 20 of toilet bowl 14 at back 17, and a filter assembly 25 coupled to odor collector 24 and extending downwardly proximate back 17 of toilet bowl 14, partially concealed by water tank 22. In FIG. 1, seat 18 is in the lowered position wherein it rests on a pair of switches 27 and 28, only one of which is visible, extending from odor collector 24. Lid 19 is shown in the upright position, resting against front surface 23 of water tank 22. To operate toilet ventilating and deodorizing apparatus 12, a person sits on seat 18, compressing at least one of switches 27 and 28, thereby starting operation of filter assembly 25.
The detail of FIG. 2 illustrates the coupling of seat 18, lid 19 and odor collector 24 to toilet bowl 14. A pair of hinge posts 29 and 30 having threaded ends 32 and 33 respectively, are affixed to toilet bowl 14 by inserting threaded ends 32 and 33 through openings 34 and 35 (not visible) in toilet bowl 14 and securing them with nuts (not shown). A pin 37 passes between hinge posts 29 and 30 through a set of seat hinges 38 and a set of lid hinges 39 so that seat 18 and lid 19 may be independently rotated thereabout. The hinge arrangement as depicted is intended to be typical and is not provided as a limitation on the means for practicing the invention.
Still referring to FIG. 2, odor collector 24 includes a base 40, configured to be positioned between top surface 20 of toilet bowl 14 and seat 18. A pair of slots 41 and 42, corresponding to openings 34 and 35 in toilet bowl 14, are formed through base 40 and receive threaded ends 32 and 33 of hinge posts 29 and 30. Shots 41 and 42 are employed to allow forward and rearward adjustments to be made in positioning odor collector 24. Odor collector 24 further includes a pair of opposing legs 43 extending from the front of odor collector 24 and partially along top surface 20 of toilet bowl 14, terminating in switch housings 44 containing switches 27 and 28, an air intake 45 mounted centrally between slots 41 and 42, and a sleeve 47 extending the length of base 40, rearward of and coupled to air intake 45.
Filter assembly 25 is coupled to odor collector 24 by a neck 48 configured to be slidably received by sleeve 47, and includes an air duct 49 extending generally perpendicularly downward from neck 48, an impeller assembly 50 coupled to air duct 49 and a filter 52 (not visible) fitted between impeller assembly 50 and air duct 49. Power is supplied to impeller assembly 50 by batteries contained in a battery case 53 affixed to an outer edge of filter assembly 25.
Toilet ventilating and deodorizing apparatus 12 is intended to be substantially unnoticeable and blend into the overall appearance of toilet 10. To achieve this desired characteristic, filter assembly 25 is intended to be positioned adjacent back 17 of toilet bowl 14 under water tank 22 as can be seen in FIG. 3. Furthermore, the various components are adjustable since toilet ventilating and deodorizing apparatus 12 is intended to be retrofitted to substantially any toilet. Therefore, to accommodate toilets having different shapes and dimensions, neck 48 is slidably received within sleeve 47 to allow filter assembly 25 to be positioned at varying distance from odor collector 24, filter assembly 25 is pivotally attached to neck 48 allowing filter assembly 25 to be pivoted against the side of substantially any toilet, and slots 41 and 42 permit odor collector 24 to be properly positioned, with air intake 45 positioned to withdraw malodorous air from toilet bowl 14.
Toilet ventilating and deodorizing apparatus 12 is illustrated in FIG. 4, showing how it neatly and compactly fits against the side of toilet 10, with a large portion inconspicuously located under water tank 22. Battery case 53 unobtrusively couples to the rearward portion of filter assembly 25 under water tank 22. The coupling of battery case 53 will be described in greater detail below. An air outlet 54 from which deodorized air from toilet bowl 14 is expelled, can be seen extending downward from the bottom of impeller assembly 50.
Referring now to FIG. 5, odor collector 24 is illustrated in an inverted position. Base 40 includes a top 57 and a bottom 58 with a space 59 therebetween. A portion of bottom 58 is cut-away to show the inside of base 40. Sleeve 47 can be seen to be a substantially square tube extending the length of the rear of base 40, having an open end 60 for receiving neck 48 and a closed end 62. Air intake 45 extends from the front of base 40 to the back of base 40, having an inlet port 63, which is positioned to withdraw air from toilet bowl 14, and an outlet port 64 coupled in gaseous communication with sleeve 47. Odor collector 24 further includes a contact assembly 67 mounted within sleeve 47, fixed to a top 68 thereof, and a pair of leads 69 and 70 extending from contact assembly 67 through space 59 of base 40 to each of switch housings 44. While two pair of leads 69 and 70 are employed in this embodiment, each extending between one of switches 27 and 28 and contact assembly 67, it will be understood by one skilled in the art that only a single pair of leads 69 and 70 is required, coupled to a single switch. A redundant switch with associated pair of leads is employed to ensure that toilet ventilating and deodorizing apparatus 12 operates when a person sits on seat 18, even if that person sits off center depressing only one switch.
In order for neck 48 to slide freely within sleeve 47, each pair of leads 69 and 70 must be placed so as to avoid obstructing neck 48. As can be seen with additional reference to FIG. 6, leads 69 and 70 are recessed within a channel 72 formed in top 68. In this manner, leads 69 and 70 extend from contact assembly 67 along sleeve 47 to open end 60 and closed end 62 without interfering with neck 48.
Referring specifically to FIG. 7, contact assembly 67 consists of a contact pad 73 having a top surface 74 and bottom surface 75, constructed of a resilient insulating material such as rubber, and a pair of contacts 77 and 78 coupled to bottom surface 75. A pair of openings 79 and 80 are formed in the front and rear of contact pad 73 underneath contacts 77 and 78. Contact pad 73 is partially recessed into a depression 82 formed in top 68, with top surface 74 of contact pad 73 fastened to top 68 of sleeve 47. Each pair of leads 69 and 70 extend from channels 72 into depression 82. Lead 69 from each pair of leads 69 and 70 is received through one of openings 79 from top surface 74 and attached to contact 77, and lead 70 from each pair of leads 69 and 70 is received through one of openings 80 from top surface 74 and attached to contact 78.
Referring now to FIG. 8, neck 48 is shown inserted within sleeve 47. Neck 48 has a generally square cross-section, with a top surface 83, a rearward side 84, a forward side 85, and a bottom 87. A pair of contacts 88 and 89 corresponding to contacts 77 and 78 respectively, extend along top surface 83 (FIG. 11) and engage contacts 77 and 78 when neck 48 is received by sleeve 47. Contact pad 73 insures adequate engagement between contacts 77, 78 and 88, 89 by extending slightly out of depression 82. As neck 48 is inserted into sleeve 47, contacts 77 and 78 engage contacts 88 and 89 and compress contact pad 73 which, being resilient, forces contacts 77, 78 against contacts 88,89.
When neck 48 is inserted into sleeve 47, and contacts 77 and 78 firmly engage contacts 88 and 89, closing of one of switches 27 and 28 starts apparatus 12. Turning now to FIGS. 9 and 10, switch 27 is illustrated. Since switch 27 and switch 28 are identical, only one is described in detail. Switch 27 is mounted on bottom 58 of base 40 within switch housing 44. Switch housing 44 is a substantially square chamber formed from walls 90 extending upward from top 57 of base 40, terminating in a rim 92 defining an opening 93. Intermediate rim 92 and walls 90 is an inward sloping shoulder 94, whose purpose will be discussed presently.
Referring specifically to FIG. 9, a bottom contact strip 95 is mounted on bottom 58 with lead 69 coupled thereto. A top contact strip 97 with lead 70 coupled thereto, and having a bore 98 formed therethrough, is positioned over bottom contact strip 95, separated therefrom by a resilient ring 99, preferably composed of rubber. A compression member 100 having a threaded bore 102 formed therethrough and an outwardly directed shoulder 103 formed around the periphery thereof, is carried by top contact 97 with threaded bore 102 concentric with bore 98. Inwardly directed shoulder 94 of housing 44 engages outwardly directed shoulder 103 of compression member 100, retaining bottom contact 95, ring 99, top contact 97, and compression member 100 within housing 44. A screw 104 extends through an element 105 of an engagement pair and continues through compression member 100, bore 98 of top contact 97 and ring 99, terminating in a spaced apart relationship with bottom contact 95. The positioning of screw 104 with respect to bottom contact 95 may be adjusted by threading screw 104 farther through or unscrewing screw 104 from threaded bore 102 of compression member 100, but it is desirable that the head of screw 104 extend upward past rim 92 of switch housing 44. A cap 108 containing a complemental element 107 of the engagement pair, fits over switch housing 44 in a sliding engagement, secured to compression member 100 by the engaged element 105 and complemental element 107 of the engagement pair. Preferably the engagement pair consists of the hook and loop elements of Velcro®.
Switch 27 is closed by seat 18 pressing against cap 108 with sufficient force, such as when a person is seated thereon. Turning to FIG. 10, it will be seen that if sufficient force is applied to cap 108, compression member 100 is forced downward, compressing resilient ring 99 and bringing screw 104 into contact with bottom contact 95. When this occurs, the gap between bottom contact 95 and top contact 97 is bridged, closing the switch, and coupled lead 69 to 70, which extend back through space 59 of base 40 to contact assembly 67.
Referring now to FIG. 11, neck 48, as discussed previously in connection with FIG. 8, includes top surface 83 carrying contacts 88 and 89, rearward side 84 and forward side 85. Neck 48 further includes an insert end 110, and a pivot end 112. Insert end 110 is received within sleeve 47 as described previously, and pivot end 112 is pivotally coupled to filter assembly 25 and will be discussed infra. An opening 113 is formed in forward side 85 proximate insert end 110, allowing admittance of malodorous air from air intake 45. Opening 113 is somewhat elongate to allow adjustment of neck 48 while maintaining communication between opening 113 and outlet port 64. An opening 114 is formed in pivot end 112, through which malodorous air leaves neck 48 to enter filter assembly 25. A pair of leads 117 and 118 extend through opening 114 into neck 48 and are coupled to an end of contacts 88 and 89 respectively. An opposing end of contacts 88 and 89, positioned proximate insert end 110, is rounded so that contacts 88 and 89 will easily slide onto contact assembly 67 without catching an edge and causing damage.
Odor collector 24 is coupled in gaseous communication with filter assembly 25 by neck 48 extending between sleeve 47 and an inlet 119 of air duct 49, as can be seen with reference to FIG. 12. Operation of impeller assembly 50 draws offensive air from toilet bowl 14 (not shown) into odor collector 24 through air intake 45, and thence through opening 113 into neck 48. With additional reference to FIG. 13, pivot end 112 of neck 48 is received in a socket 120 formed within inlet 119 of air duct 49. Pivot end 112 of neck 48 is rounded to form a substantially sealing engagement with, and permit some rotation within socket 120. Rotation of pivot end 112 is halted by contact between neck 48 and air duct 49. As discussed supra, the rotation of filter assembly 25 with respect to neck 48 permits adjustment to accommodate a wide variety of toilet configurations.
Still referring to FIG. 12, malodorous air progresses through inlet 119 into air duct 49, out outlet 121 of air duct 49, and is subsequently drawn through filter 52, where the malodor is removed from the air, into impeller assembly 50. With additional reference to FIG. 14, impeller assembly 50 consists of a housing 122 enclosing a fan 123 having a hub 124. Fan 123 is driven by a motor 125 positioned in hub 124, powered by battery case 53 coupled to the outer surface of housing 122. Rotation of fan 123 draws filtered air through an opening 127 in housing 122 positioned adjacent to hub 124, and expels the filtered air through an outlet 128.
Referring now to FIG. 15, impeller assembly 50 further consists of a socket 130 extending from housing 122 and defining a receptacle 132 over opening 127. Socket 130 has an outer wall 133 and an inner wall 134 defining a space 135 therebetween. Inner wall 134 slopes outward to join outer wall 133 at a rim 137, opposite housing 122, and further includes a radially inwardly directed shoulder 138 proximate housing 122 for supporting filter 52, and a radially inwardly directed shoulder 139 proximate rim 137 for supporting air duct 49. Filter 52 is received within receptacle 132 of socket 130, covering opening 127. The slope of inner wall 134 provides a tight fit around the periphery of filter 52, preventing air flow around same. A ridge 140 extends from air duct 49 encircling outlet 121, configured to be received by socket 130 and engage shoulder 139. Air duct 49 is held securely in place by screws 142 inserted through socket 130 into ridge 140.
A battery case 53 is attached to outer wall 133 of socket 130, providing power to operate motor 125. Battery case 53 includes a body 143 for holding batteries, a cover 144 closing body 143, and clips 145 and 146 for coupling battery case 53 to socket 130. With additional reference to FIG. 18, battery case 53 preferably holds four D cell batteries 147, and includes conventional negative and positive terminal contacts 148 and 149 respectively, for receiving batteries 147, with the negative terminal contacts being compression coils to insure a secure fit and connection. Negative and positive terminal contact 148 and 149 are coupled in a conventional manner, and terminate at clips 145 and 146 respectively.
Still referring to FIG. 15, clips 145 and 146 function to mechanically and electrically coupled battery case 53 to impeller assembly 50. Clips 145 and 146 are configured to be received by brackets 150 and 152 carried by outer wall 133 of socket 130 respectively. Details of the connection between battery case 53 and impeller assembly 50 can be seen with additional reference to FIGS. 19 and 20. FIG. 19 illustrates clip 145 extending outward from an end of battery case 53, to be received within bracket 150, substantially parallel to outer wall 133. A lead 153 is coupled to bracket 150, extending through space 135 between inner wall 134 and outer wall 133, and terminating in a contact 154 extending from rim 137 (FIG. 15). FIG. 20 illustrates clip 146, extending parallel to battery case 53, being plugged into bracket 152 through a slot 155 formed in outer walls 133. A lead 157 is coupled to bracket 152, extending through space 135 between inner wall 134 and outer wall 133, and terminating in a contact 158 extending from rim 137 (FIG. 15).
The details of the electrical connections between battery case 53 and impeller assembly 50, and between impeller assembly 50 and air duct 49 are shown in FIG. 16. Battery case 53 is easily attached to impeller assembly 50 by sliding clip 145 into bracket 150, then plugging clip 146 into bracket 152 with battery case 53 flush against outer wall 133. Lead 153 extends from bracket 150 to motor 125 then terminates in contact 154 (FIG. 15). Lead 157 extends from bracket 152 and terminates in contact 158 (FIG. 15). Air duct 49 includes spring contacts 159 and 160, corresponding to contacts 154 and 158 respectively, attached adjacent ridge 140 and placed so as to engage contacts 154 and 158 respectively when air duct 49 is coupled to impeller assembly 50. Details of the connection between contacts 154 and 158 and spring contacts 159 and 160 are shown in FIG. 17. Spring contacts are preferred to insure a solid connection.
A diagrammatic representation of an operating circuit 162 of toilet ventilating and deodorizing apparatus 12 is illustrated in FIG. 21. Switches 27 and 28 having contacts 95 and 98 are coupled in parallel, each having leads 70 extending from contacts 98 which terminate at contact 78, and leads 69 extending from contacts 95 which terminate at contact 77. Progressing from switches 27 and 28 in a clock wise direction, contact 78, found in sleeve 47, is coupled to contact 89 of neck 48 when neck 48 is inserted into sleeve 47. Lead 118 extends from contact 89, terminating in spring contact 160 mounted on air duct 49. Spring contact 160 disengageably engages contact 158 on rim 137 when air duct 49 is fitted to impeller assembly 50. Lead 157 extends from contact 158 and is disengageably coupled to the positive terminal of batteries 147 by mounting battery case 53 onto impeller assembly 50, thereby engaging contacts 152 and 146. The negative terminal of batteries 147 are coupled to motor 125 through lead 153 when battery case 53 is mounted, coupling contacts 145 and 150. Lead 153 then couples motor 125 to switches 27 and 28 by two disengageable couplings. Lead 154 terminates in contact 154 on rim 137 which, when air duct 49 is fitted to impeller assembly 50, engages spring contact 159. Lead 117, extending from contact 159 terminates in contact 88 of neck 48. Contact 88 engages contact 77 of sleeve 47, coupling lead 117 to leads 69. Upon closing of either or both switches 27 and 28, circuit 162 is completed and motor 125 is powered.
Detachable coupling are provided, coupling each of the removable parts, specifically sleeve 47, neck 48, air duct 49, impeller assembly 50 and battery case 53, so that an individual can easily install system 12 with little thought to wiring, battery case 53 can be removed for battery changes, and air duct 49 can be removed to change or clean filter 52 without the need to worry about disconnecting wiring. Furthermore, in this manner, the wiring is entirely contained within system 12 to enhance appearance and prevent accidental disconnections.
Turning now to FIG. 22, an alternate embodiment of an odor collector generally designated 170 is illustrated. Odor collector 170 is generally identical to and shares in common with odor collector 24, elements, including base 40, air intake 45 and slots 41 and 42. In contrast, odor collector 170 differs from odor collector 24 in that a sleeve 172 is substantially straight for receiving a straight neck 173, as opposed to the slightly convex sleeve 47 and corresponding neck 48 of odor collector 24.
Referring now to FIG. 23, a further embodiment of an odor collector generally designated 180 is illustrated. Odor collector 180 is generally identical to and shares in common with odor collector 24, elements, including air intake 45 switches 27 and 28, and slots 41 and 42. In contrast, odor collector 180 differs from odor collector 24 in that a sleeve 182 is concave for receiving a corresponding neck 183, as opposed to the slightly convex sleeve 47 and corresponding neck 48 of odor collector 24. Furthermore, with additional reference to FIG. 24, odor collector 180 includes a base 184 having a raised air dam 185 extending along the inner edge thereof, between switches 27,28 and air intake 45. Air dam 185 prevents air outside bowl 14 from being drawn between seat 18 and top surface 20 into air intake 45.
An alternate embodiment of a toilet ventilating and deodorizing apparatus generally designated 212, is illustrated in FIGS. 25 and 26. Apparatus 212 is substantially similar to apparatus 12 including an odor collector 213 and a filter assembly 214, mounted onto a toilet in a manner generally identical to that discussed above in connection with apparatus 12, and will not be discussed in great detail here.
Odor collector 213 includes a base 215 having a top surface 217, a bottom surface 218, a front edge 219 and a back edge 220. Base 215 is coupled to a toilet by hinge posts (not shown) extending through slots 222 and 223 formed through base 215. Base 215 further includes a sleeve 224 extending along back edge 220 on top surface 217, an air intake 225 extending from front edge 219 between slots 222 and 223 and abutting sleeve 224, and a tab 227 extending from front edge 219 carrying a switch 228. Apparatus 212 employs a single switch 228 instead of two as was employed in apparatus 212 for purposes of illustration. Air intake 225 has an inlet port 229 formed through base 215 from bottom surface 218, and extending upward into air intake 225. One skilled in the art will understand that while inlet port 229 is directed downward in this embodiment, an inlet port may be used extending horizontally inward from the front of the odor collector as was shown in apparatus 12.
Filter assembly 214 is coupled to odor collector 213 by a neck 230 configured to be slidably received by sleeve 224, and includes an air duct 232 extending generally perpendicularly downward from neck 230, an impeller assembly 233 coupled to air duct 232 and a filter (not visible) fitted between impeller assembly 233 and air duct 232 in a manner generally similar to that described above in connection with embodiment 12. Impeller assembly 233 and air duct 232 are generally similar to impeller assembly 50 and air duct 49 of apparatus 12, and are therefore not described in detail.
Air duct 232 includes an inlet (not visible) defined by an extension 237, and an outlet (not visible). Air duct 232 further includes a battery case 239 which will be discussed in more detail below. Impeller assembly 233 includes a fan, and a motor (not visible) which are generally identical to that described above, contained in a housing 243 having an inlet 244 (not visible) and an outlet 245. The motor driving the fan is powered by batteries 247 contained in battery case 239. Air flow through apparatus 212 is generally similar to that described above, and is therefore omitted here.
Sleeve 224 is in gaseous communication with air intake 225, and receives neck 230. Neck 230 is a generally tubular member having a forward side 248, an insert end 249 and a pivot end 250 extending from filter assembly 214. Insert end 249 is received within sleeve 224 as described previously, and pivot end 250 is pivotally coupled to filter assembly 214 and will be discussed infra. An opening 252 is formed in forward side 248 proximate insert end 249, allowing admittance of malodorous air from air intake 225. Opening 252 is somewhat elongate to allow adjustment of neck 230 while maintaining communication between opening 252 and air intake 225. An opening 253 is formed in pivot end 250, through which malodorous air leaves neck 230 to enter filter assembly 214.
Toilet ventilating and deodorizing apparatus 212 is intended to be substantially unnoticeable and blend into the overall appearance of a toilet. To achieve this desired characteristic, filter assembly 214 is intended to be positioned adjacent the back of a toilet bowl under the water tank as was discussed previously in connection with apparatus 12. Furthermore, the various components are adjustable since toilet ventilating and deodorizing system 212 is intended to be retrofitted to substantially any toilet. Therefore, to accommodate toilets having different shapes and dimensions, neck 230 is slidably received within sleeve 224 to allow filter assembly 214 to be positioned at varying distance from odor collector 213, filter assembly 214 is pivotally attached to neck 230 allowing filter assembly 214 to be pivoted against the side of substantially any toilet, and slots 222 and 223 permit odor collector 213 to be properly positioned, with air intake 225 in communication with a toilet bowl.
Operation of impeller assembly 233 draws offensive air from the toilet bowl (not shown) into odor collector 213 through air intake 225, and thence through opening 252 into neck 230. Pivot end 250 of neck 230 is received over extension 237 extending from the top of air duct 232 (visible in FIG. 26), defining an inlet (not visible). Pivot end 250 of neck 230 is rounded to form a substantially sealing engagement with, and permit some rotation about extension 237. Rotation of pivot end 250 is limited by a set screw 254 extending through a slot 255 formed in pivot end 250 into extension 237. Rotation of neck 230 is limited by the length of slot 255 which moves about set screw 254. As discussed supra, the rotation of filter assembly 214 with respect to neck 230 permits adjustment to accommodate a wide variety of toilet configurations. Malodorous air progresses through air duct 232 and is subsequently drawn through the filter, where the malodor is removed from the air, into impeller assembly 233 and is expelled from outlet 245.
Power is supplied to impeller assembly 233 by batteries 247 held in battery case 239 formed along an edge of air duct 232. Battery case 239 consists of a tubular body 258 running vertically along the side of air duct 232 configured to contain batteries 247 stacked end to end. Tubular body 258 preferably includes a top end cap 256 carrying a positive terminal contact 259 and closing the top of tubular body 258, and a bottom end cap 261 carrying a negative terminal contact 260 and closing the bottom of tubular body 258. A lead 262 extends from negative terminal contact 260, and is coupled to the motor in housing 243 by a releasable coupling 263. A lead 264 and 265 extends from the motor (not shown) and positive terminal contact 259 respectively, and terminate in a connector 267. Switch 228 carried on tab 227 of base 215 includes a connector 268 which receives connector 267, coupling switch 228 into the circuit. While external leads are shown in this embodiment, one skilled in the art will understand that internal wiring, such as those described in embodiment 12 above, may be employed.
Referring to FIGS. 27 and 28, switch 228 includes a contact strip 270 mounted onto tab 227. A block 272 of resilient material is carried upon contact strip 270 and extends in a vertical direction. A horseshoe contact 273 is received about the upper portion of block 272 with lower ends 274 spaced apart from contact strip 270 when switch 228 is open. A housing 275 having an opening 277 defined by an upwardly directed rim 278 is mounted onto tab 227, covering contact strip 270, with block 272 and horseshoe contact 273 projecting upward through opening 277. A cover 279 engages horseshoe contact 273 and extends down terminating above housing 275. Application of a downward force to cover 279, such as by engagement with a toilet seat, compresses block 272 allowing contact between lower ends 274 of horseshoe contact 273 and contact strip 270, closing switch 228. Leads 280 and 282 extend from contact strip 270 and horseshoe contact 273 respectively, terminating in connector 268.
In contrast to apparatus 12, an external connection is made between switch 228 and batteries 247. While installation of apparatus 212 requires the additional step of coupling connectors 267 and 268, manufacturing the apparatus with external leads and connections is less costly than internal leads and connectors.
Finally, removal and insertion of batteries 247 in apparatus 212 may be simplified by securing end caps 256 and 261 in tubular body 258 using pins 283 and 284 as illustrated in FIG. 29 and 30. Referring specifically to FIG. 29, pin 283 extends through tubular body 258 into top end cap 256. To install batteries 247, pin 283 is removed, allowing removal of cap 256. Batteries 247 are then simply dropped into tubular body 258 and cap 256 replaced, secured by pin 283. Referring specifically to FIG. 30, pin 284 extends through tubular body 258 into bottom end cap 261. To remove batteries 247, pin 284 is removed, allowing removal of cap 261. Batteries 247 will then simply dropped out of tubular body 258. Cap 261 is then replaced and secured by pin 284.
An alternate embodiment of a neck generally designated 287 is illustrated in FIGS. 31 and 32. In general similarity to previously described embodiment 48, the immediate embodiment includes in common, an insert end 110, a pivot end 112, and a forward side 85 having an opening 113, other commonalties will be readily apparent to one skilled in the art.
In contrast to neck 48, neck 287 includes a top surface 288 in which parallel channels 289 and 290 are formed. A pair of contacts 292 and 293 analogous to contacts 88 and 89 are partially recessed within channels 289 and 290 respectively. Contacts 292 and 293 are constructed of coiled conductive material imparting a rough surface and resilience to the portion extending out of channels 289 and 290, differing from the planar strips of contacts 88 and 89. The roughness helps remove oxidation from the opposing contacts in the sleeve, and the resilience allows compression of the contacts insuring a good connection.
An alternate embodiment of a toilet ventilating and deodorizing apparatus generally designated 312 is illustrated in FIGS. 33. Apparatus 312 is illustrated mounted on toilet 10 replacing apparatus 12. Toilet 10 has been described above as including toilet bowl 14, having front 15 and back 17, toilet seat 18 and lid 19 coupled to top surface 20 of toilet bowl 14 by hinges at back 17 of toilet bowl 14, and a water tank 22 having a front surface 23. Front 15 and back 17 of toilet 10 will again provide directional reference throughout the ensuing descriptions.
Still referring to FIG. 33, toilet ventilating and deodorizing apparatus 312 includes an odor collector 324 mounted on top surface 20 of toilet bowl 14 at back 17, and a filter assembly 325 coupled to odor collector 324 and extending downwardly proximate back 17 of toilet bowl 14, partially concealed by water tank 22. In FIG. 33, seat 18 is in the lowered position wherein it rests on a pair of switches 327 and 328, only one of which is visible, extending from odor collector 324. lid 19 is shown in the upright position, resting against front surface 23 of water tank 22. To operate toilet ventilating and deodorizing apparatus 312, a person sits on seat 18, closing at least one of switches 327 and 328, thereby starting operation of filter assembly 325.
As in FIG. 2, the detail of FIG. 34 illustrates the coupling of seat 18, lid 19 and odor collector 324 to toilet bowl 14. This is accomplished in the same manner as described above, with threaded ends 32 and 33 inserted through openings 34 and 35 in toilet bowl 14 and securing them with nuts (not shown). The hinge arrangement has already been described previously, and will not be described further.
Still referring to FIG. 34, odor collector 324 includes a base 340, configured to be positioned between top surface 20 of toilet bowl 14 and seat 18. A pair of slots 341 and 342, corresponding to openings 34 and 35 in toilet bowl 14, are formed through base 340 and receive threaded ends 32 and 33 of hinge posts 29 and 30. Slots 341 and 342 are employed to allow forward and rearward adjustments to be made in positioning odor collector 324. Odor collector 324 further includes a pair of opposing legs 343 extending from the front of odor collector 324 and partially along top surface 20 of toilet bowl 14, terminating in switch housings 344 containing switches 327 and 328, an air intake 345 mounted centrally between slots 341 and 342, and a sleeve 347 extending the length of base 340, rearward of and coupled to air intake 345.
Filter assembly 325 is coupled to odor collector 324 by a neck 348 configured to be slidably received by sleeve 347, and includes a generally hemispherical air duct 349 coupled to neck 348, an impeller assembly 350 and a filter 352 (not visible) carried within a filter assembly housing 351 and coupled thereby to air duct 349. Power is supplied to impeller assembly 350 by batteries contained in a battery case 353 (not visible) carried within housing 351.
Toilet ventilating and deodorizing apparatus 312 is intended to be substantially unnoticeable and blend into the overall appearance of toilet 10 as is apparatus 12 and 212. To achieve this desired characteristic, filter assembly 325 is intended to be positioned adjacent back 17 of toilet bowl 14 under water tank 22 as can be seen in FIG. 35. Furthermore, the various components are adjustable since toilet ventilating and deodorizing apparatus 312 is intended to be retrofitted to substantially any toilet. Therefore, to accommodate toilets having different shapes and dimensions, neck 348 is slidably received within sleeve 347 to allow filter assembly 325 to be positioned at varying distance from odor collector 324, housing 351 is pivotally attached to air duct 349 allowing filter assembly 325 to be pivoted against the side of substantially any toilet, and slots 341 and 342 permit odor collector 324 to be properly positioned, with air intake 345 positioned to withdraw malodorous air from toilet bowl 14.
Toilet ventilating and deodorizing apparatus 312 is illustrated in FIG. 36, showing how it neatly and compactly fits against the side of toilet 10, with a large portion inconspicuously located under water tank 22. Apparatus 312 closely conforms to the lines of toilet 10 without interfering with the operation of seat 18 and lid 19.
Referring now to FIG. 37, odor collector 324 is illustrated in an inverted position. Base 340 includes a top 357 and a bottom 358 with a space 359 therebetween. A portion of bottom 358 is cut-away to show the inside of base 340. Sleeve 347 can be seen to be a substantially square tube extending the length of the rear of base 340, having an open end 360 for receiving neck 348 and a closed end 362. Air intake 345 extends from the front of base 340 to the back of base 340, having an inlet port 363, which is positioned to withdraw air from toilet bowl 14, and an outlet port 364 coupled in gaseous communication with sleeve 347. Odor collector 324 further includes a contact assembly 367 mounted within sleeve 347, fixed to a top 368 thereof, and a pair of leads 369 and 370 extending from contact assembly 367 through space 359 of base 340 to each of switch housings 344. While two pair of leads 369 and 370 are employed in this embodiment, each extending between one of switches 327 and 328 and contact assembly 367, it will be understood by one skilled in the art that only a single pair of leads 369 and 370 is required, coupled to a single switch. A redundant switch with associated pair of leads is employed to ensure that toilet ventilating and deodorizing apparatus 312 operates when a person sits on seat 18, even if that person sits off center depressing only one switch. While apparatus is shown having internal wiring for purposes of illustration, as is apparatus 312, one skilled in the art will understand that external wiring as employed in embodiment 212 may be used instead.
In order for neck 348 to slide freely within sleeve 347, each pair of leads 369 and 370 must be placed so as to avoid obstructing neck 348. As can be seen with additional reference to FIG. 38, leads 369 and 370 are recessed within a channel 372 formed in top 368. In this manner, leads 369 and 370 extend from contact assembly 367 along sleeve 347 to open end 360 and closed end 362 without interfering with neck 348. At open end 360 and closed end 362, additional channels 371 are formed coupling channel 372 to base 340.
Referring specifically to FIG. 39, contact assembly 367 consists of a contact pad 373 having a top surface 374 and bottom surface 375, constructed of a resilient insulating material such as rubber, and a pair of contacts 377 and 378 coupled to bottom surface 375. Contacts 377 and 378 each have ends angled toward top surface 374. Angled ends of contacts 377 and 378 extend from bottom surface 375 of contact pad 373, terminating adjacent top surface 374. A pair of openings 379 and 380 are formed in the front and rear of contact pad 373 underneath contacts 377 and 378. Contact pad 373 is partially recessed into a depression 382 formed in top 368, with top surface 374 of contact pad 373 fastened to top 368 of sleeve 347. Each pair of leads 369 and 370 extend from channels 372 into depression 382. Lead 369 from each pair of leads 369 and 370 is received through one of openings 379 from top surface 374 and attached to contact 377, and lead 370 from each pair of leads 369 and 370 is received through one of openings 380 from top surface 374 and attached to contact 378.
Referring now to FIG. 40, neck 348 is shown inserted within sleeve 347. Neck 348 has a generally square cross-section, with a top surface 383, a rearward side 384, and a forward side 385. A pair of contacts 388 and 389 corresponding to contacts 377 and 378 respectively, extend along top surface 383 (FIG. 42) and engage contacts 377 and 378 when neck 348 is received by sleeve 347. Contact pad 373 insures adequate engagement between contacts 377, 378 and 388, 389 by extending slightly out of depression 382. As neck 348 is inserted into sleeve 347, contacts 377 and 378 engage contacts 388 and 389 and compress contact pad 373 which, being resilient, forces contacts 377, 378 against contacts 388,389.
When neck 348 is inserted into sleeve 347, and contacts 377 and 378 firmly engage contacts 388 and 389, closing of one of switches 327 and 328 starts apparatus 312. Turning now to FIG. 41, switch 327 is illustrated. Since switch 327 and switch 328 are identical, only one is described in detail. Switch 327 is mounted on top 357 of base 340 within switch housing 344. Switch housing 344 is a substantially square chamber formed from walls 390 extending upward from top 357 of base 340, terminating in an inwardly directed rim 392 defining an opening 393. A bottom contact strip 395 is mounted on top 357 with lead 369 coupled thereto. A top contact 397 with lead 370 coupled thereto, and having a bore 398 formed therethrough, is positioned over bottom contact strip 395, separated therefrom by a resilient ring 399, preferably composed of rubber. A compression member 400 having a threaded bore 402 formed therethrough and an outwardly directed shoulder 403 formed around the periphery thereof, is carried by top contact 397 with threaded bore 402 concentric with bore 398. Inwardly directed rim 392 of housing 344 engages outwardly directed shoulder 403 of compression member 400, retaining bottom contact 395, ring 399, top contact 397, and compression member 400 within housing 344. A screw 404 extends through an element 405 of an engagement pair and continues through compression member 400, bore 398 of top contact 397 and ring 399, terminating in a spaced apart relationship with bottom contact 395. The positioning of screw 404 with respect to bottom contact 395 may be adjusted by threading screw 404 farther through or unscrewing screw 404 from threaded bore 402 of compression member 400. A cap 408 containing a complemental element 407 of the engagement pair, fits over switch housing 344 in a sliding engagement, secured to compression member 400 by the engaged element 405 and complemental element 407 of the engagement pair. Preferably the engagement pair consists of the hook and loop elements of Velcro®.
Switch 327 is closed by seat 18 pressing against cap 408 with sufficient force, such as when a person is seated thereon, to depress compression member 400. It will be seen that if sufficient force is applied to cap 408, compression member 400 is forced downward, compressing resilient ring 399 and bringing screw 404 into contact with bottom contact 395. When this occurs, the gap between bottom contact 395 and top contact 397 is bridged, closing the switch, and coupling lead 369 to 370, which extend back through space 359 of base 340 to contact assembly 367.
Referring now to FIG. 42, neck 348, as discussed previously in connection with FIG. 40, includes top surface 383 carrying contacts 388 and 389, rearward side 384 and forward side 385. Neck 348 further includes an insert end 410 receivable within sleeve 347 as described previously, and an opposing end 412 coupled to air duct 349. An opening 413 is formed in forward side 385 proximate insert end 410, allowing admittance of malodorous air from air intake 345. Opening 413 is somewhat elongate to allow adjustment of neck 348 while maintaining communication between opening 413 and outlet port 364. An opening 414 is formed in opposing end 412, through which malodorous air leaves neck 348 to enter filter assembly 325. A pair of leads 417 and 418 extend through opening 414 into neck 348 and are coupled to an end of contacts 388 and 389 respectively. An opposing end of contacts 388 and 389, positioned proximate insert end 410, is rounded so that contacts 388 and 389 will easily slide onto contact assembly 367 without catching an edge and causing damage.
Odor collector 324 is coupled in gaseous communication with filter assembly 325 by neck 348 extending between sleeve 347 and an inlet 419 of air duct 349, as can be seen with reference to FIG. 43. With additional reference to FIG. 44, neck 348 is shown received within sleeve 347, with leads 417 and 418 passing inside neck 348 to continue on to air duct 349, and leads 369 and 370 depressed within channel 372 avoiding interference with neck 348.
Turning now to FIG. 45, housing 351 of filter assembly 325 includes endwalls 422, sidewalls 423, a top 424, and an open bottom 425, configured to receive impeller assembly 350 and battery case 353. Air duct 349 is rotatably coupled to top 424 of housing 351 the details of which will be described below. Impeller assembly 350 includes a housing 427 containing a fan 428, and has an inlet 429 (not visible) and an outlet 430. A socket 432 extends from housing 427 and defines a receptacle 433 over inlet 429. Filter 352 is received within receptacle 433 of socket 432, covering inlet 429. The walls of socket 432 slope radially outward to provides a tight fit around the periphery of filter 352, preventing air flow around same. A ridge 434 extends from and encircles the top end of filter 352, configured to be received by housing 427, with an o-ring 435 sealing the engagement. A pair of contact posts 437 and 438 extend upward from housing 427, terminating in contacts 439 and 440 respectively. The purpose of posts 437 and 438 will be discussed in greater detail presently. Impeller assembly 350 is held securely in place by screws 442 inserted through housing 351 into housing 427.
Battery case 353 is a box having braces 443 and a center post 444 securely retaining batteries. Battery case 353 preferably holds four D cell batteries 445. Battery case 353 is received within housing 351 adjacent impeller assembly 350 and secured by securing means preferably consisting of an easily engageable and disengageable detent 447 received by a corresponding opening 448 formed in sidewall 423 of housing 351. With additional reference to FIG. 46, means for securing battery case 353 within housing 351 is illustrated. While those skilled in the art will understand that various known securing apparatus may be used, preferably, a biasing member 449 from which detent 447 extends, is attached to the inner surface of battery case 353 with detent 447 extending out through an opening 450. To insert battery case 353 into housing 351, detent 447 is forced inward, back into battery case 353 through opening 450 against the bias of bias member 449 as indicated by broken lines. Battery case 353 will then freely enter housing 351 from open bottom 425. Once properly positioned, opening 450 will align with opening 448 in housing 351 and detent 447 will be forced concurrently through openings 450 and 448 securing battery case 353 in place.
A detailed view of the inner workings of filter assembly 325 is illustrated in FIG. 47. Malodorous air enters filter assembly 325 through neck 348 into air duct 349. Housing 351 further includes an opening 452 defined by in turned lips 453 formed in top 424 which receives o-ring 435 and the upper edge of socket 432 thereagainst. Air duct 349 is constructed of an inner member 454 and an outer member 455 rotatably coupled thereto. Inner member 454 has an outwardly flared lower edge 457 which is inserted through opening 452 and engage inwardly directed lip 453. Outer member 455, from which neck 348 extends, has a lower edge 458 extending outside of housing 351. The malodorous air passes through air duct 349 into filter 352, being drawn by rotation of fan 428. Fan 428 is driven by a motor 459 positioned within a hub 460 thereof, powered by batteries 445 within case 353.
Still referring to FIG. 47, with additional reference to FIGS. 49 and 50, alternating pairs of cross-connected terminal contacts are mounted within battery case 353 and housing 351. Positive terminal contacts 462 alternately mounted within battery case 353 and housing 351 oppose negative terminal contacts 463. Negative and positive terminal contacts 463 and 462 respectively, are conventional terminal contacts for receiving batteries 445, with the negative terminal contacts 463 being compression coils to insure a secure fit and connection. Negative and positive terminal contact 463 and 462 are coupled in a conventional manner, with negative terminals 463 coupled by a lead 464 to a contact 465 mounted inside housing 351 on top 424, and positive terminals 462 coupled to lead 418 extending from contact 389 in neck 348, through air duct 349, between inner and outer members 454 and 455. Lead 417 from neck 348 parallels lead 418 and terminates in a contact 467 mounted inside housing 351 on top 424 spaced apart from contact 465.
FIG. 48 illustrates a lead 468 coupled to motor 459 extending up post 437 and terminating in contact 439. It will be understood that another lead 469 extends from motor 459 up post 438, to terminate in contact 440. Posts 437 and 438 with corresponding leads 468 and 469 respectively, can be seen with additional reference to FIG. 49. When impeller assembly 350 is secured within housing 351, contacts 439 and 440 on posts 437 and 438 engage contacts 465 and 467 respectively. At this point, closing of one of switches 327 and 328 completes the circuit, and starts operation of toilet ventilating and deodorizing apparatus 312.
A diagrammatic representation of an operating circuit 470 of toilet ventilating and deodorizing apparatus 312 is illustrated in FIG. 51. Switches 327 and 328 having contacts 395 and 397 are coupled in parallel, each having leads 370 extending from contacts 397 which terminate at contact 378, and leads 369 extending from contacts 395 which terminate at contact 377. Progressing from switches 327 and 328 in a clock wise direction, contact 378, found in sleeve 347, is coupled to contact 389 of neck 348 when neck 348 is inserted into sleeve 347. Lead 418 extends from contact 389 and is coupled to the positive terminal of batteries 445 by mounting battery case 353 onto impeller assembly 350. The negative terminal of batteries 445 are coupled to motor 459 through leads 464 and 469 when impeller assembly 350 is mounted coupling contacts 465 and 440. Lead 468 then couples motor 459 to switches 327 and 328 by two couplings. Lead 468 terminates in contact 439 on post 437 which, when impeller assembly 350 is fitted to housing 351 engages contact 467. Lead 417, extending from contact 467 terminates in contact 388 of neck 348. Contact 388 engages contact 377 of sleeve 347, coupling lead 417 to leads 369. Upon closing of either or both switches 327 and 328, circuit 470 is completed and motor 459 is powered.
Various changes and modifications to the embodiments herein chosen for purposes of illustration will readily occur to those skilled in the art. To the extent that such modifications and variations do not depart from the spirit of the invention, they are intended to be included within the scope thereof which is assessed only by a fair interpretation of the following claims.
Having fully described the invention in such clear and concise terms as to enable those skilled in the art to understand and practice the same, the invention claimed is: | A toilet bowl ventilating and deodorizing apparatus comprises an odor collector for extracting air from a toilet bowl, a filter assembly for deodorizing the air extracted from the toilet bowl, and a neck coupling the filter assembly to the odor collector, with the odor collector and the neck supporting the filter assembly adjacent the toilet bowl. The odor collector includes a base attachable to the toilet bowl, an air intake carried by the base and positionable adjacent an interior of the toilet bowl, and a sleeve carried by the base in gaseous communication with the air intake. The filter assembly includes an air duct, an impeller assembly for providing air flow through the apparatus, the air duct is coupled to the filter assembly, and a filter is carried between the impeller assembly and the air duct. A switch is carried by the odor collector for activating the filter assembly, a power source for supplying power to the impeller assembly, and a power circuit coupling the power source to the impeller assembly and the switch. | 4 |
[0001] This application is a Continuation of, and claims priority under 35 U.S.C. § 120 to, International application no. PCT/EP2005/051611, filed Apr. 13, 2005, and claims priority therethrough under 35 U.S.C. § 119 to German application no. No 110 2004 020 378.4, filed Apr. 23, 2004, the entireties of which are incorporated by reference herein.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to the field of sealing in rotating machines, and more particularly to a leaf seal.
[0004] 2. Brief Description of the Related Art
[0005] A gas turbine includes a rotor, on which various stages with compressor blades and turbine blades are provided, and a stator housing. The rotor is mounted in bearings at each end of the rotor shaft.
[0006] The control of the gas flow inside the gas turbine is of paramount importance with regard to both the functionality and the effectiveness. Sealing techniques are used at various locations along the rotor shaft in order to reduce the axial gas flow along the shaft. This is especially important next to the bearings in order to prevent the oil which is used in the bearings from overheating due to the hot gases of the gas flow.
[0007] Two types of sealing techniques are traditionally used in this situation—usually alternatively, sometimes also in combination. These are labyrinth seals and brush seals.
[0008] Labyrinth seals have no metal-to-metal contact between the rotor and the stator; the sealing effect is therefore relatively small. However, they offer the advantage of low rotational friction and of a therefore virtually unlimited service life.
[0009] On the other hand, brush seals have higher friction losses on account of the friction between the bristle ends and the rotor shaft. This results in wear, which limits the service life of the seal. However, brush seals stem the axial gas flow more effectively, in particular in the case of higher axial pressure differences.
[0010] The use of these techniques for sealing in gas turbines has numerous restrictions. First, the axial pressure difference that they can withstand is still fairly low. In the case of the brush seals, this is due to the bristles, which have the same stiffness in the axial and circumferential directions: high pressures can cause the bristles to yield in the axial direction. The capability of the seals to allow a significant radial movement and to resist it is also low.
[0011] The design of a brush seal is often a compromise between the use of a supporting plate, which is intended to give sufficient axial support, and the non-restriction of the radial movement.
[0012] In order to avoid the disadvantages of the known brush seals, a leaf seal has been proposed in U.S. Pat. No. B1-6,343,792, this leaf seal performing the same function as either a labyrinth seal or a brush seal but having the advantages of both. Instead of the bristles, which are produced from wires of circular cross section, thin metal leaves are assembled in a certain arrangement (see, for example, FIG. 3 of U.S. Pat. No. B1-6,343,792 or FIG. 1 of the present application). The leaves, which are oriented with their surfaces essentially parallel to the axial direction, are much stiffer in the axial direction than in the circumferential direction. Thus the seal can withstand higher pressure differences without restricting their possibilities for allowing radial movements. The wide region on the rotor, which is swept by the tips of the leaves, provides the opportunity of producing a hydrodynamic force during operation, and this hydrodynamic force can separate the leaf tips from the shaft. In this way, a distance of a few microns can be produced and maintained, so that the wear, the friction heat and the friction losses can be reduced virtually to zero.
[0013] The basic design relates to a number of thin metal leaves which have a controlled air gap between them and are fastened at a predetermined angle to the radius. The air gap is a critical design parameter: it enables an air flow to occur in order thus to produce the hydrodynamic effect; however, it must not be so large as to allow an excessive axial air flow.
[0014] Two variants of leaf spring designs are possible: in the one variant, the leaves are blown downward, but in the other they are blown upward. In the variant having the leaves blown downward, there is a distance between the leaf tips and the shaft during the assembly and start-up, and this gap is reduced to very small values by the use of an air flow between the leaves. On the other hand, in the variant having the upward blowing, there is slight mutual influencing between the leaf tips and the shaft during the start-up, and a distance is produced when the shaft is accelerated. In both cases, the flow of the medium through the air gaps between the leaves is critical, as is the control of the seal's inside diameter, which is produced by the leaf tips.
[0015] The air flow through the leaves can be varied by using a front and a rear plate which leave a narrow gap free between the surfaces of the leaf stack and the plates (see abovementioned FIGS. 1 and 3 ). A careful design of these geometries makes it possible to control the upward or downward blowing effects. It may also be desirable to assist the downward blowing effect by an active pressure feed along the length of the leaves or inward from the front side or from the rear directions.
[0016] One of the other main advantages of the leaf seal concept is a greater tolerance of the radial movement than in labyrinth or brush seals. This requires a large distance there between the inside diameter of the front and rear end plates and the shaft.
[0017] Depending on the geometry selected for the seal and on the diameter of the shaft to be sealed, the number of leaves can be several thousand or many thousand. The accuracy with which said leaves can be produced, assembled and connected, in the course of which a reproducible air gap between each pair of leaves is ensured, is critical for the successful implementation of every possible seal design.
[0018] The joining method for fixing the leaves in their position could be a mechanical technique, such as clamping in place, welding, or brazing or any possible combination thereof. It is quite obviously important that a minimum disturbance of the leaves or of their relative positions occurs during the joining process.
[0019] Various joining methods have already been proposed in the abovementioned publication U.S. Pat. No. 1-6,343,792. In the exemplary embodiments pertaining to FIGS. 1 to 21 of that publication, the leaves, with their top transverse edge, are brazed in place in a housing. In the exemplary embodiments according to FIGS. 22 to 28 , the leaves are fastened in curved segments by a known welding method, such as laser welding, electron beam welding (EBW) or TIG welding, the welding being effected in the radial direction from outside through the segment up to the top transverse edges of the leaves (see FIG. 25 and the description on page 20 , lines 7 - 48 ). The distance between the leaves can be set in this case by positioning elements (FIGS. 22 to 24 ) embossed in the leaves, by separate spacers ( FIG. 27A ), or by integral spacers ( FIG. 27B ). With regard to the use of the electron beam welding, no further details are given in the publication.
[0020] Electron beam welding is a method which is available on an industrial basis for the development or production of devices assembled from components within a wide range of various alloys and geometries.
[0021] The nature of the heat input, focussed to a high degree, and the accuracy with which the method can be controlled make it especially suitable for the welding of leaves, with or without spacers, for leaf seals.
[0022] Electron beam welding involves the use of special equipment in order to generate the electron beam. This equipment includes a cathode in order to emit electrons, which are then accelerated down an evacuated column by means of high voltage and are focussed on the substrate as a narrow beam with accurately controlled energy and position.
[0023] The penetration depth of the beam changes with the beam energy and the density of the target material, but is normally within a range of a few 10 microns right up to a few millimeters. The material volume affected is quickly melted, and a fusion welded joint with the surrounding material is produced.
[0024] For the optimum use of electron beam welding, those surfaces of the parts ( 23 a, b in FIG. 5 of the present application) to be connected to one another which are to be welded should be in close contact (joint 24 ), so that a weld 25 capable of bearing load is obtained. This is different from most welding methods (see FIG. 4 of the present application), in which an intermediate space 21 is normally required between the parts 20 a, b to be connected as filling space for a filler material in order to produce a weld 22 capable of bearing load.
[0025] The lower values of the disturbance in the material which are to be encountered in electron beam welding and are inherent in the method make the method especially suitable for the welding of thin components such as leaves, which are especially susceptible to such disturbances.
[0026] One aspect of present invention proceeds from the application of electron beam welding in the production of leaf seals which are assembled from individual leaves, with or without separate spacers.
[0027] In this case, the leaves must be produced from a suitable material which can easily be welded by electron beam welding. The design of the leaves and the way in which they are put together must be carefully controlled in order to optimize the joining by means of electron beam welding.
[0028] In particular, other aspects of the present invention start from the fact that successful electron beam welding is based on close contact between the surfaces to be connected in order to minimize the disturbances occurring during the welding. This close contact is not ensured in the joining technique as disclosed in publication US-B 1-6,343,792 . The welding there is effected in the radial direction from outside through the curved segment-shaped holding element and includes the top transverse edges of the leaves, which, on account of their arrangement in a circle, are relatively far apart. For the abovementioned reasons, such a configuration of the welding process involves considerable disadvantages for the application of electron beam welding.
SUMMARY OF THE INVENTION
[0029] One aspect of the present invention therefore provides a welded leaf seal which can avoid the disadvantages of known leaf seals and can be distinguished in particular by markedly reduced disturbances in the region of the welded connections, and also includes methods of producing such a leaf seal.
[0030] Another aspect of the present invention includes designing the leaves in such a way and arranging them in the leaf seal in such a way that they abut against one another at the side edges directly or via intermediate spacers along at least one contact line extending over a plurality of leaves, and designing the welded connections as welds directed along the at least one contact line. Owing to the fact that the electron beam welding is carried out along the contact lines at which the elements to be connected abut against one another directly, especially high-grade welded connections which are able to cope, in particular with the loads occurring in a gas turbine, are obtained.
[0031] Spacers are preferably provided in order to set the distance between the leaves, the at least one contact line running in the region of the spacers, and the spacers being arranged in the outer end region of the leaves. The spacers may either be formed on the leaves as regions of greater thickness, the spacers either having a constant thickness or being designed with a thickness decreasing inward.
[0032] However, the spacers may also be designed as elements embossed in the leaves. In this case, the leaves can be produced by a simple stamping and embossing process and can then easily be oriented to one another and connected (welded) to one another.
[0033] Each leaf, in the radial direction, preferably has at least two embossed spacers which are arranged one behind the other and fix the position of the leaves, namely distance and inclination, relative to one another.
[0034] The leaves can be held in their entirety with the outer end in a housing and can be welded to the housing, the leaves being connected to one another and to the housing via laterally arranged welds which run in the axial direction and extend through the housing up to the leaves.
[0035] However, the leaves can also be welded on the outside to an encircling backing ring on the outside, preferably a segmented backing ring, which is then held in a housing.
[0036] A preferred configuration of the method according to the invention is characterized by the fact that the leaves are held in a housing and are welded through the housing to one another and to the housing.
[0037] Spacers integrated in the leaves are preferably used for arranging the leaves, these spacers being embossed in the leaves by an embossing process or an etching process (PCM—Photo-Chemical Machining). After the leaves provided with the spacers have been produced, the leaves are put into a clamping device in which they are firmly oriented in their positions characteristic of the subsequent leaf seal.
BRIEF DESCRIPTION OF THE DRAWINGS
[0038] The invention is to be explained in more detail below with reference to exemplary embodiments in connection with the drawing, in which:
[0039] FIG. 1 shows a perspective side view of the typical construction of a leaf seal as used in a gas turbine;
[0040] FIG. 2 shows, in the axial direction, the side view of the arrangement, inclined from the radial direction, of individual leaves with their intermediate spacers;
[0041] FIG. 3 shows the view of a leaf seal, comparable with FIG. 1 , in the circumferential direction, with a front and a rear end plate;
[0042] FIG. 4 shows the configuration of the welding location in the case of conventional welding with filler material;
[0043] FIG. 5 shows the configuration, comparable with FIG. 4 , of the welding location in the case of electron beam welding, during which the parts to be welded abut against one another with a close joint;
[0044] FIG. 6 shows, as viewed in the axial direction, a stack of leaves with integral spacers of constant thickness, which, on account of the angular offset at the transition between spacer and leaf body, form a continuous, circular contact line, along which they are welded to one another according to the invention;
[0045] FIG. 7 shows, in a representation comparable with FIG. 6 , a stack of leaves with integral, slightly wedge-shaped spacers which, if the wedge angle is equal to the angular offset between adjacent leaves, touch one another over the entire surface of the spacers;
[0046] FIG. 8 shows, in a representation comparable with FIG. 6 , a stack of leaves with integral, embossed pairs of spacers which automatically set and fix the correct distance and angular offset between adjacent leaves and form a multiplicity of concentric contact lines suitable for the welding;
[0047] FIG. 9 shows a section of a leaf seal according to an exemplary embodiment of the invention, in which section the welding of the leaves is executed from the sides through a housing accommodating the leaves; and
[0048] FIG. 10 shows two steps during the welding of a leaf stack with embossed spacers having a backing ring, the leaves first of all being positioned relative to one another by means of the spacers ( FIG. 10 a ) and then the welds being placed for connecting the leaves to one another and to the backing ring.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0049] Shown in FIG. 1 in a perspective side view is the typical construction of a leaf seal as used in a gas turbine. The leaf seal 12 seals a rotor shaft 11 , rotating in the arrow direction, of the gas turbine 10 with respect to a housing 14 . A stack of tightly spaced-apart thin leaves 13 is arranged in a ring in the circular ring-shaped intermediate space between the rotor shaft 11 and the housing 14 . With their surface, the leaves 13 are oriented parallel to the axis of rotation of the machine. According to FIG. 2 , the leaves are tilted from the radial direction by an angle w 1 and have a narrow gap or intermediate space 18 between them, which is preferably established by spacers 17 arranged between the leaves 13 . The spacers 17 of FIG. 2 are shown as separate elements. However, they may also be integrated in the leaves as shown in FIGS. 6-8 .
[0050] According to FIGS. 1 and 3 , the air flow through the leaves 13 can be varied by using a front and a rear end plate 15 and 16 , respectively, which leave a narrow gap free between the surfaces of the leaf stack and the end plates 15 , 16 (distances a and b in FIG. 3 ). A careful design of these geometries makes it possible to control the upward or downward blowing effects mentioned at the beginning. It may also be desirable to assist the downward blowing effect by an active pressure feed along the length of the leaves or inward from the front side or from the rear directions.
[0051] One of the other main advantages of the leaf seal concept shown in FIG. 1 or 3 is a greater tolerance of the radial movement than in labyrinth or brush seals. This requires a large distance between the inside diameter of the front and rear end plates 15 , 16 and the rotor shaft 11 (distances c and d in FIG. 3 ). The gap between the leaves 13 and the rotor shaft (distance e in FIG. 3 ) is only a few microns.
[0052] The successful electron beam welding is based on close contact between the surfaces of the parts 23 a, b to be joined ( FIG. 5 ) in order to minimize the disturbances which occur. These requirements must be fulfilled as effectively as possible in the assembled leaves.
[0053] If the leaves of a stack are joined together directly in their final, circular positions, careful attention must then be paid to the angular offset of each leaf relative to its neighbor. This is shown in FIG. 6 with reference to a first preferred exemplary embodiment of the invention. Here, the leaves 26 have integral spacers 27 in the form of widened end regions of constant thickness. If the individual leaves 26 of the stack are put together with the requisite angular offset, gaps or intermediate spaces 29 are obtained between the leaves 26 , and wedge-shaped gaps 28 are obtained at the outer margin or top margin of the stack, so that the outer margin does not have the close contact between adjacent leaves which is required for optimum electron beam welding. On the contrary, the contact between the adjacent leaves takes place at the transition between the spacers 27 and the leaf body and forms the contact line 36 , depicted as a broken line.
[0054] The contact line 36 shown of the point-to-point contact between the leaves 26 is the preferred line for the electron beam welding. In comparison, electron beam welding which is applied at the outer margin of the leaf stack, where the gaps 28 between the leaves 26 are shown, tends more toward shrinkage disturbance. It is also more difficult to control the penetration depth of the welding, since the electron beam can penetrate into the gap 28 between the leaves 26 without resistance.
[0055] Several possible alternatives for reducing this problem are shown in FIGS. 7 and 8 . In FIG. 7 , the leaves 30 , likewise at their outer ends, have integral spacers 31 in the form of widened regions in order to create the requisite gaps or intermediate spaces 32 between the leaves 30 . In this exemplary embodiment, the angular offset between adjacent leaves is achieved and established by the integral spacers 31 being of wedge-shaped design with a wedge angle w 2 in such a way that their thickness decreases uniformly inward. The result of this is that the leaves 30 are in contact over the entire surface of the integral spacers 31 , i.e., the contact line is widened to form a contact band.
[0056] In FIG. 8 , the leaves 33 also have integral spacers 34 , 35 at their outer ends, these spacers 34 , 35 being in the form of embossed horizontal beads which are arranged one behind the other in the radial direction and are at a distance from one another. Given suitable shaping of the spacers 34 , 35 , both the correct angular offset and the correct distance apart is obtained automatically between adjacent leaves, so that the embossed leaves 33 can be assembled in a simple manner to form stacks and can then be immediately welded. In the case of the spacers 34 , 35 shown in FIG. 8 , four contact lines 37 , depicted as broken lines, are obtained, along which the electron beam welding can be carried out.
[0057] The configurations shown in FIGS. 6-8 relate to leaves having integral spacers. However, similar concepts can be applied just as easily to leaves having separate spacers.
[0058] The use shown in particular in FIG. 8 of spacers designed in this way has a number of advantages. Firstly, the angular offset can be set exactly from leaf to leaf, as a result of which the need for the leaves to be put together exactly is reduced. Secondly, as clearly shown in FIG. 8 , there are numerous lines on which the electron beam welding can be focussed in order to produce acceptable welding with little disturbance.
[0059] As already mentioned, the leaves according to FIG. 8 can be formed by a method such as embossing, for example. The embossing permits the production of features which emerge from the surface, this having more than one advantage: with a suitable design and a suitable development, embossed features such as those shown above can help to accurately position the leaves relative to one another; furthermore, they can produce the requisite angular offset from one leaf to the next; and they can provide contact points in order to increase the effectiveness of the electron beam welding.
[0060] Another possibility shown in FIG. 9 of the electron beam welding consists in the fact that a housing 39 can be welded directly around the outside of the locally fixed ends of the leaves 38 . The T-shaped leaves 38 can be put together and positioned in the housing, and then the electron beam welding penetrates laterally at the predetermined lines through the housing 39 and welds the leaves 38 together in a single step by corresponding welds 40 .
[0061] If—as shown in FIG. 8 —an embossing step is to be used during the production of the leaves, to be precise either independently or in combination with a sheet-forming method, it is possible to allow the leaves to fall directly from the embossing tool into a suitably designed clamping device. This clamping device (not shown in the figures) then orients and positions the leaves relative to one another. This can be with the desired final bending or in a straight section. Such a straight section can be welded in a linear position, and the desired lengths can then be bent to the final curvature, to be precise before the final welding at a backing ring or another structural member.
[0062] Such a process is shown in FIG. 10 in two steps ( FIG. 10 a and FIG. 10 b ). The leaves 33 provided according to FIG. 8 with embossed integral spacers 34 , 35 are put together according to FIG. 10 a to form a stack, the correct distance apart and angular offset being set by the spacers 34 , 35 . Along one of the contact lines 37 , the leaves are then connected with a first weld 41 by electron beam welding. The stack with the leaves 33 welded to one another is then put into a backing ring 43 which can be a whole ring or a segmented ring with, for example, two halves and firmly connected according to FIG. 10 b to the backing ring 43 by means of a second weld 42 . The backing ring 43 provided with the leaves 33 can then be inserted into a recess, provided for this purpose, in the housing.
List of Designations
[0063] 10 Gas turbine
[0064] 11 Rotor shaft
[0065] 12 Leaf seal
[0066] 13 Leaf
[0067] 14 Housing
[0068] 15 , 16 End plate
[0069] 17 Spacer (separate)
[0070] 18 Gap (intermediate space)
[0071] 19 Gas flow
[0072] 20 a, b Part
[0073] 21 Intermediate space (filling space)
[0074] 22 , 25 Weld
[0075] 23 a, b Part
[0076] 24 Joint
[0077] 26 , 30 , 33 Leaf
[0078] 27 , 31 Spacer (integral)
[0079] 28 Gap (wedge-shaped)
[0080] 29 , 32 Gap (intermediate space)
[0081] 34 , 35 Spacer (embossed)
[0082] 36 , 37 Contact line
[0083] 38 Leaf
[0084] 39 Housing
[0085] 40 Weld
[0086] 41 , 42 Weld
[0087] 43 Backing ring
[0088] a, . . . ,e Distance
[0089] w 1 , w 2 Angle
[0090] While the invention has been described in detail with reference to exemplary embodiments thereof, it will be apparent to one skilled in the art that various changes can be made, and equivalents employed, without departing from the scope of the invention. The foregoing description of the preferred embodiments of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and modifications and variations are possible in light of the above teachings or may be acquired from practice of the invention. The embodiments were chosen and described in order to explain the principles of the invention and its practical application to enable one skilled in the art to utilize the invention in various embodiments as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto, and their equivalents. The entirety of each of the aforementioned documents is incorporated by reference herein. | A leaf seal for sealing a shaft rotating about an axis, in particular in a gas turbine, includes a multiplicity of spaced-apart leaves ( 26 ) which are arranged in a concentric circle around the axis and are fixed in their position by welded connections produced by electron beam welding, the leaves ( 26 ), with their surfaces, being oriented essentially parallel to the axis. The welded connections of the leaves are improved by the leaves ( 26 ) being designed in such a way and being arranged in the leaf seal in such a way that they abut against one another at the side edges directly or via intermediate spacers ( 27 ) along at least one contact line ( 36 ) extending over a plurality of leaves ( 26 ), and by the welded connections being designed as welds directed along the at least one contact line ( 36 ) and oriented in axial direction. | 5 |
FIELD OF THE INVENTION
The present invention relates generally to medical treatment of wounds, and more particularly to an improved wound shield and irrigation dressing for treating wounds to promote the overall healing process and to discourage enteric fistula and wound infections.
BACKGROUND OF THE INVENTION
Wound shields for treating enteric fistula and wound infections are known. The express purpose of these prior devices is to provide an irrigation dressing for patients as a replacement for the typical gauze type dressings. It is well known that gauze type dressings are not only messy, but result in constant re-opening of the wounds when the dressings are changed, which could cause infections and delay the healing process. Further, dressing changes usually cannot be performed by the patient alone. They are often quite painful to the patient, expensive, and not conducive to providing frequent irrigation of the wound with medical solutions.
One known prior art irrigation dressing proposed to alleviate the problems associated with gauze type dressings is shown in expired U.S. Pat. No. 3,026,874. The device taught in that patent provides a wound shield that forms a dam around a wound and includes a clear flexible plastic window or cover for observing the healing process. The dam is fabricated of a continuous loop of foam rubber. To facilitate flushing and air control, several holes are provided at selected locations along the perimeter of the shield. The device is held in place using belts and snap fasteners that are rigidly attached to the wound shield.
Although the wound shield described above is preferred over gauze dressings, the foam rubber dam is too rigid for good sealing qualities. Further, the overall wall depth of the device is too shallow to accommodate adequate irrigation solution volumes. Lastly, the dam often comes into contact with the wound thus disrupting the healing process.
A modified wound shield or irrigating dressing is shown in FIG. 1 . Wound shield 2 includes a generally oval shaped dam 20 and a window 18 attached over the top of the dam 20 . The shield is secured to a patient by a first belt 4 and a second belt 6 . The ends of the belts 4 and 6 are rigidly connected to window 18 by snap fasteners. Dam 20 includes an irrigation aperture 3 adapted to receive a tube 10 connected on a remote end to a supply of irrigation solution 12 . Dam 20 includes a drying aperture 3 adapted to receive a tube 8 connected on a remote end to a supply of oxygen, and a draining aperture 7 adapted to receive a tube 14 connected to an associated pump 16 .
In use of the above device, a flow of irrigation solution constantly irrigates the wound on the patient by a timer control, patient control, or care giver control. Oxygen or air is alternately supplied into the shield to dry the wound, while pump 16 removes the irrigation solution from the enclosed area. The wound is visible through window 18 as it heals without being exposed to contaminants. The dressing can be used for about two weeks before changing is required.
The dam of the wound shield described above comprises a hollow, highly flexible tube, which is inflated with air prior to or during use. The desired firmness is obtained by controlling the pressure of air within the dam.
Although the wound dressing is modestly successful in treating patients, the device requires a fair amount of readjustment after it is installed on the patient because the dressing twists and bends with movement of the patient. This is primarily due to a lack of flexibility in the wound shield. Further, the device tends to buckle in the middle due to a lack of cross-sectional rigidity in the inflatable dam section. This causes leakage from under the wound shield as well as undesirable contact between the wound and the window.
Therefore, it would be desirable to provide an irrigation dressing that is less rigid to prevent separation from the skin of the patient as the patient moves. The irrigation dressing should not be too soft so that it crumples with patient movement.
It is also desirable to provide an irrigation dressing that can be readily used with vacuum assist closure (VAC) devices for applying a vacuum to a wound.
It is further desirable to provide an irrigation dressing system that can conform to the shape of a moving patient yet retaining its fluid containment and vacuum integrity.
SUMMARY OF THE INVENTION
In accordance with a preferred embodiment of the invention, a wound shield and irrigation dressing system is provided to be worn on ambulatory patients for protecting and enclosing wounds. The wound shield allows for frequent irrigation of the wound with an irrigation solution and alternate frequent drying of the wound, while also providing for drainage of the irrigation solution and selective application of a vacuum to the wound.
The wound shield includes a hollow inflatable tubular dam formed of an inner peripheral surface defining a central opening adapted to surround the wound of the individual, an outer peripheral surface defining the outermost extremity of the dam, a bottom body-engaging surface and a top surface connecting said inner and outer peripheral surfaces to one another. A somewhat stiff clear plastic window is provided having generally flat front and rear planar surfaces. The flat rear planar surface of the window is attached to the top surface of the dam, so that a central cavity opening is defined under the window and surrounded by the oval dam.
In a preferred aspect of the invention, the wound shield includes an inner peripheral ridge extending from the inner peripheral surface beyond the bottom body-engaging surface of the dam downwardly away from the window. An outer peripheral ridge is formed on the tubular dam extending from the outer peripheral surface beyond the bottom body-engaging surface of the dam downwardly away from the window. The ridges on the bottom or rear side of the device provide an overall elongate “U-shaped” contact surface for contacting the skin, eliminating the need to apply skin adhesives to the patient, while also sealing in fluids and eliminating vacuum loss. The ridges also play an important part in improving the cross-sectional rigidity of the dam and for preventing fluid leakage. Ridges can also extend from the front or top surface of the dam aiding in the adhesion of the dam to the window, and adding to the overall cross-sectional rigidity of the dam.
In another preferred aspect of the invention, the wound shield includes a plurality of connectors attached to the front planar surface of the clear plastic window. Each connector is disposed at different locations outside the central opening of the dam, and each is adapted to be releasably attached to a connecting end of a belt. The connectors are pivotable about an axis parallel to the front planar surface of the window.
In yet another preferred aspect of the invention, the subject wound shield includes a resilient self-sealing plug disposed inside the dam. The plug is adapted to receive a hypodermic needle, whereby air can be forced into the dam through the hypodermic needle causing the dam to inflate. The plug is “self healing” and seals itself upon removal of the hypodermic needle, so that the fluid containment integrity of the dam is not compromised. Precise control over the pressure within the dam is thereby enabled.
An object of the present invention is to provide an improved wound shield with pivoting belt connectors that allow for patient movement without the need for readjustment of the wound shield.
A further object is to provide a wound shield with one or more radial ribs disposed on the perimeter of the dam to prevent fluid leakage from out of the central cavity. It is yet another object of the invention to provide a wound shield with an improved cross-sectional rigidity.
A further object is to provide an airtight dam facilitating vacuum assisted closure (VAC). The irrigating dressing is particularly useful with this technique because the wound can be thoroughly cleaned with fluids and thoroughly dried with air using the device before vacuum is applied. The wound can be treated with VAC without irrigation.
It is another object of the invention to provide a wound shield having an inflatable dam with an improved inflating device for precise control over the fluid pressure within the dam.
Another object of the invention is to provide a wound shield that enables frequent wound cleansing, drying and drainage, while also being easy to use and maintained by care givers and patients.
Another object is to make the patient ambulatory while wearing the device.
These and other objects will become apparent from the following description of the preferred embodiments taken together with the accompanying drawings and appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention may take physical form in certain parts and arrangements of parts, the preferred embodiments of which will be described in detail in this specification and illustrated in the accompanying drawings which form a part hereof, and wherein:
FIG. 1 is a perspective view of a prior art wound dressing device;
FIG. 2 is a top view of a preferred wound shield and a preferred belt arrangement in accordance with the present invention;
FIG. 3 is a cross-sectional view taken along the line A—A of the preferred wound shield shown in FIG. 2 ;
FIG. 4 is a bottom view of the preferred dam of the preferred wound shield shown in FIG. 2 ;
FIG. 5 is a bottom view of an alternative embodiment of the wound shield using cut outs in the window for irrigating, drying, and draining; and,
FIG. 6 is a top view of an alternative embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings wherein the showings are for the purpose of illustrating the preferred embodiments of the invention only, and not for purpose of limiting same, FIGS. 2-4 show a wound shield 30 including a hollow tubular inflatable dam 32 , and a clear plastic window 34 attached to the dam 32 . Dam 32 is formed of an inner peripheral surface or wall 42 which defines and surrounds a central opening 50 . Dam 32 also includes an outer peripheral surface or a wall 44 connected to inner peripheral surface 42 by a rear or bottom body-engaging surface 48 and a front or top surface 46 .
Dam 32 is provided with an irrigation aperture 52 extending from outer peripheral surface 44 through inner peripheral surface 42 . Aperture 52 is adapted to receive or otherwise couple with an irrigation tube for providing communication between an irrigation system and central opening 50 . Typically, the irrigation system provides an irrigation solution with medicinal characteristics for continuous or frequent cleansing of the wound. A drying aperture 54 is provided, which is adapted to receive or otherwise couple with a drying tube connected to an associated air supply. Drying aperture 54 provides communication between the air supply and central opening 50 for continuous or selective intermittent drying of the wound after irrigation. The drying aperture is also useful for connection to an associated source of vacuum (not shown) for use with VAC devices to apply a vacuum to the wound. A drainage aperture 56 is provided, preferably on a side of the dam opposite from the irrigation and drying apertures as shown. The drainage aperture is adapted to receive or otherwise couple with a drainage tube. The drainage tube could be connected to a pump, a collecting device, or a like device, to facilitate the removal of the irrigation solution, and dead skin and blood discharged from the wound. Both apertures 52 and 56 extend through the dam 32 from outer peripheral surface 44 through inner peripheral surface 42 . These apertures can be plugged using suitable stoppers or the like when used as a VAC, when the patient is ambulatory, or as desired. It is to be appreciated that any of the apertures can be adapted for connection with an associated source of vacuum.
Dam 32 is preferably manufactured using a rotational casting or a rotational molding such as slush molding. The mold is typically made of aluminum but could be made of a variety of other metals. Dam 32 is formed from a soft liquid plastic, preferably vinyl, and the apertures are formed by extending a core pin through the mold, and removing the core pin after the liquid plastic cures.
Dam 32 further includes a soft self-sealing plug 40 preferably molded into the outer wall 44 . Self-sealing plug 40 is adapted to receive a hypodermic needle used to inflate the dam 32 with air. The needle is inserted through the self-sealing plug 40 and the bulb is compressed to force air into the dam until the desired firmness of the dam 32 is obtained. The needle can be withdrawn at any time from the self-sealing plug 40 without any leakage of the air after removal. The self-sealing plug also allows for addition or removal of air at any time. Self-sealing plug 40 is preferably made of nitriale rubber.
Window 34 is made of a semi-hard clear plastic vinyl and has a generally flat planar bottom surface 33 and a generally flat top planar surface 35 . In the embodiment illustrated, the window has an overall generally rectangular shape. Preferably, bottom planar surface 33 is attached to front surface 46 of the dam 32 using ultra-violet curable adhesive. However, various other types of adhesives could be used. Window 34 completely encloses central opening 50 of the dam 32 so that central opening 50 can remain airtight when the wound shield 30 is placed on the body of the patient, except for apertures 52 , 54 , and 56 . It is preferred that window 34 encompass outer peripheral surface 44 of the dam 32 to increase the rigidity of the wound shield 30 .
A pair of spaced apart connector assemblies 64 are disposed on top planar surface 35 of window 34 at opposite sides of the window. Connector assemblies 64 include a set of spaced apart co-axial tubes 66 holding a rod 68 that is connected to a set of eyelets 70 . Tubes 66 are preferably made of plastic and could be bonded to top planar surface 35 of the window 34 or could be formed during the molding of window. Rods 68 and eyelets 70 are placed in tubes 66 prior to bonding or molding. Rod 68 and eyelet 70 are pivotable about an axis parallel to top planar surface 35 , so that movement or twisting of the patient does not cause wound shield 30 to move from its position on the body of the patient. Further, connector assemblies are placed at a location outside central opening 50 to ensure that even pressure is applied to the entire perimeter of dam 32 when wound shield 30 is on the body of a patient. Rods 60 and eyelets 70 are preferably made of metal, but could be made of plastic or the like. The rods 68 extend completely across the face of the would shield 30 and in that way help prevent the shield from buckling in the middle during use such as along the line defined by section A—A in FIG. 2 .
A pair of belts 36 and 38 are provided for holding wound shield 30 at a fixed location on the patient, so that central area 50 surrounds the wound. Belts 36 and 38 are preferably made of an elastic material, such as latex or neoprene foam, and are preferably non-absorbent and easy to clean. Each belt includes a first and a second connecting end 58 . Each connecting end 58 includes a connecting portion 60 attached to the belt, and a hook portion 62 adapted to engage eyelet 70 . It should be appreciated that in some circumstances, the wound shield may only need one belt because of the size or location of the wound. Further, the belt could be fixed at one end to a fixed connector on the wound shield, and be pivotable at the other end. It also should be appreciated that the releasable engagement of the belt and the connector assembly could employ connector types other than the preferred eye and hook arrangement.
With particular reference now to FIG. 3 , dam 32 includes a ridge 72 extending angularly from inner peripheral surface 42 beyond and away from the bottom body-engaging surface 48 . Dam 32 also includes a ridge 74 extending angularly from outer peripheral surface 44 beyond and away from the bottom body-engaging surface 48 . Ridges 72 and 74 cooperate in holding wound shield 30 in a fixed position on the patient's body, even during movement and twisting of the patient. Further, ridges 72 and 74 seal central opening 50 and prevent any fluids or vacuum from escaping, and prevent contaminants from entering central area 50 . Ridges 72 and 74 also alleviate the need to apply skin adhesives to the skin of the patient prior to applying the front body-engaging surface of the wound shield, while adding substantially to the cross-sectional rigidity of the dam 32 .
With continued reference to FIG. 3 , dam 32 preferably also includes a ridge 76 extending angularly from inner peripheral surface 42 beyond and away from top surface 46 and a ridge 78 extending angularly from outer peripheral surface 44 beyond and away from top surface 46 . Ridges 76 and 78 aid in the adhesion process of front surface 46 to the back surface 33 of window 34 . Additionally, ridges 76 and 78 increase the cross-sectional rigidity characteristic of dam 32 , which helps prevent the center of the wound shield 30 from buckling after securing wound shield 30 on the body of a patient.
It should be appreciated that in some cases, such as in stubborn wounds, more pressure is necessary for irrigation of the wound. It also should be appreciated that it is not always necessary to place irrigation aperture, drying aperture, and drainage aperture through the dam. For example, FIG. 5 shows a wound shield 77 having a dam 79 attached to a window 81 . A first hole 75 is cut out of window 81 and covered over by a piece of adhesive tape 80 or plug. A second hole 82 is cut out of window 81 and covered by a piece of adhesive tape 84 or plug. The holes 75 , 82 are adapted to receive the tip of an asepto syringe. Adhesive tape 80 or plug can be removed and irrigation solution can be communicated to the wound through hole 75 via large syringe, or the like. Further, an air source could be used to communicate air to the wound through hole 75 for drying the wound. Adhesive tape 84 or plug can be removed to provide drainage of irrigation solution, dead skin, and blood from central area 50 . After cleansing, drying, and drainage, tape 80 and 84 or plug can be placed back over holes 75 and 82 , respectively, protecting the wound from outside dirt or bacteria.
It should be noted that the shape of the wound shield could take on many forms, and the connector assemblies could be disposed on the window in a variety of different orientations. For example, FIG. 6 shows a wound shield 30 ′ having an overall smaller size than the shield 30 shown in FIGS. 2-4 . Only a single belt 36 ′ is needed to receive the shield 30 ′ to a patient. This type of wound shield could be useful for a wound near the groin area of an individual, such as one that would occur in a hernia operation or catheterization procedure. The wound shield 30 ′ is formed and functions substantially identical to the shield 30 described above. Like parts are indicated in FIG. 6 with a primed (′) suffix.
The foregoing descriptions are specific embodiments of the present invention. It should be appreciated that these embodiments are described for purposes of illustration only, and that numerous alterations and modifications may be practiced by those skilled in the art without departing from the spirit and scope of the invention. It is intended that all such modifications and alterations be included insofar as they come within the scope of the invention as claimed or the equivalents thereof. | An irrigation dressing is provided including a hollow inflatable tubulardam with a central opening adapted to surround the wound of the individual. A semi-hard resilient clear plastic window is attached to the dam, such that the central opening is completely enclosed on a front surface of the dam. The dressing includes an inner peripheral ridge and an outer peripheral ridge extending beyond a bottom or back body-engaging surface of the dam which facilitates drawing a vacuum. A plurality of connectors are attached to a front planar face surface of the clear plastic window. At least one connector is pivotable about an axis parallel to the front planar surface of the window. A self-sealing plug is disposed inside the dam so that the dam can be inflated to selected pressures using an associated hypodermic needle or the like. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This is a continuation of International Application No. PCT/EP2011/063537, filed Aug. 5, 2011, which application claims priority to German Patent Application No. 10 2010 033 568.1, filed Aug. 6, 2010 and to U.S. Provisional Application No. 61/371,353, filed Aug. 6, 2010, which are incorporated herein by reference in their entirety.
TECHNICAL FIELD
The technical field relates to cargo loading systems for means of transport. In particular, the technical field relates to a cargo loading system for a cargo compartment of a means of transport. Furthermore, the technical field relates to an aircraft comprising the cargo loading system and to a method for loading and unloading cargo to/from a means of transport by means of the cargo loading system.
BACKGROUND
In cargo loading systems (also called control and conveyance systems) dedicated controllers may be used that process and forward data and control signals from connected devices. In this process, many different ways of communication within the system and the environment of the system may be used, for example in extraneous systems.
From DE 10 2006 047 238 B4 a cargo loading system comprising guide rails and a setting device for aligning bearing parts on tolerance-associated structures is known. EP 1 110 860 A1 describes a cargo loading system for an aircraft for loading and unloading loading units, wherein roller drive units are provided for transporting the cargo, latch units are provided for locking the cargo, and control units are provided for operating the roller drive units and/or the latch units.
In addition, other objects, desirable features and characteristics will become apparent from the subsequent summary and detailed description, and the appended claims, taken in conjunction with the accompanying drawings and this background.
SUMMARY
According to various exemplary embodiments, provided are a cargo loading system/cargo loading control system for a cargo compartment of a means of transport, an aircraft comprising a corresponding cargo loading system, and a method for loading and unloading cargo to/from a means of transport by means of the cargo loading system.
According to an exemplary embodiment of the present disclosure, a cargo loading system for a cargo compartment of a means of transport is stated, which cargo loading system comprises at least one power drive unit for transporting cargo of the means of transport, a control module, and a BUS system comprising a bus. The at least one power drive unit and the control module are connected to the bus by means of data lines. The control module is designed for generating control signals for the at least one power drive unit and maintenance data of the at least one power drive unit for the control and maintenance of the at least one power drive unit. The BUS system is designed for transmitting the control signals and maintenance data of the at least one power drive unit between the control module and the at least one power drive unit.
Such a cargo loading system may make it possible for the control module to be connected to a bus of the BUS system, and to be able to communicate or exchange data, by way of the bus, with one or several power drive units that are also connected to the bus. In this arrangement the data flow is controlled by way of an access method (protocol), which can, for example, take place by means of the control module. All the connected components, for example the control module and the at least one or several power drive units, are cross-linked (networked) through the BUS system. Supplying power to the components and to the bus can take place by way of a direct-current or alternating-current supply.
With the use of such a cargo loading system with a BUS system for transmitting control signals and maintenance signals it is possible to do away with discrete lines between individual components such as the control module, and with the at least one or several power drive units, and consequently the expenditure relating to cabling is minimized, and additional components such as power drive units can be connected in a simple and flexible manner. Furthermore, when compared to conventional cargo loading systems a reduction in weight can be achieved because an already existing hardware platform can be used.
The bus can, for example, be a CAN-bus which by means of the controller area network (CAN) interconnects several components that have equal rights by way of a two-wire bus. Such a CAN-bus may have high resistance to malfunction and a real-time capability; it may also be more cost effective than conventional buses.
Maintenance data that by means of the BUS system can be transmitted between the at least one power drive unit and the control module can, for example, be fault messages of the at least one power drive unit, which fault messages can be transmitted by the control module to external units, for example to a control system.
Such a cargo loading system represents an intelligent network, by means of which network existing hardware platforms such as integrated module avionics (IMA) that are currently present in a means of transport, for example in an aircraft, can be used. In this arrangement the control module can be a cargo loading system (CLS) ATA50 or an ATA25-control module. By means of the BUS system the system components of the cargo loading system can be reduced, when compared with a cargo loading system without a BUS system, in that existing hardware platforms are used, which can result in a reduction in weight. The control module can, for example, be integrated in a central hardware platform.
The means of transport can, for example, be an aircraft such as an airplane, a helicopter or a zeppelin, or a motor vehicle, a rail vehicle, a watercraft or a spacecraft.
According to another exemplary embodiment of the present disclosure, the control module is designed for controlling the BUS system.
Such control of the BUS system by means of the control module may be associated with an advantage in that no further control module needs to be stated for controlling the BUS system, and in that the BUS system can be optimized and efficiently controlled according to the control signals and maintenance data to be transmitted.
According to another exemplary embodiment of the present disclosure, the cargo loading system furthermore comprises a control system, wherein the control module is connected to the control system. The control system is designed for transmitting and receiving the control signals and maintenance data of the at least one power drive unit by means of the control module and of the BUS system. The control system is designed for processing the control signals and maintenance data.
The control module can be connected to the control system by means of a plug-in connection, and according to another exemplary embodiment can be integrated in the control system. The control system can be a hardware platform, a central control system of an aircraft and/or a control system of the type IMA ATA42.
Such connection of a control module of the cargo loading system to a control system can, for example, provide an advantage in that information of the control system, for example relating to a driving state or transport state of the means of transport (for example depending on the flight phase), can be transmitted to the control module. For example it is thus possible, during a journey or during takeoff or landing of the means of transport, to switch off the cargo loading system by means of the control module based on information relating to the driving state or transport state, which information is transmitted to the control system.
According to another exemplary embodiment of the present disclosure, the control system, which can, for example, be a hardware platform, is designed for the connection of further modules apart from the control module. The further modules are, for example, selected from the group comprising a control system module for door systems and an undercarriage module. The cargo loading system is, among other things, designed to be switched on and off by means of at least one of the further modules on the basis of transport phases of the means of transport.
Such a cargo loading system with a control module that is connected to a (central) control system, for example a hardware platform, which cargo loading system comprises further modules, for example a control system module for doors, and an undercarriage module, makes it possible for the cargo loading system to be switched off while the means of transport is engaged in transport, for example during flight of an aircraft. According to requirements of regulatory authorities, cargo loading control systems and drive systems must be switched off during flight. Switch-off cannot be carried out solely by the control module of the aircraft (ATA50-chapter or ATA25-chapter). Data relating to the state of closure of all the doors (for example during takeoff or landing) can easily be tapped by the control system, to which, for example, the control system module for doors is connected, and can be transmitted to the bus system, which subsequently can initiate switch-off, for example by way of the electronic fuse unit or semiconductor fuse unit (for example the secondary power distribution box, SPDB) of the cargo loading system. Furthermore, the control system can detect whether the aircraft is still on the ground, for example by means of the undercarriage module connected to the control system. Thus the cargo loading system can be switched off by means of the control system, by way of the control module during a flight phase and during a takeoff and landing phase of the aircraft, in that information relating to the flight phase or to the takeoff and landing phase is transmitted by means of corresponding modules that are connected to the control system. In this manner less cabling and reduced susceptibility to malfunction can be provided. Such switching-off can also take place by way of a door system that is connected to the control system.
Furthermore, in a control system it is possible to connect modules for identifying the cargo, which modules can then transfer information relating to the cargo, by means of the control system, to the control module, which modules subsequently correspondingly control the at least one power drive unit or several power drive units. In this arrangement the cargo can, for example, be identified by means of a cargo evaluation system (CES).
According to another exemplary embodiment of the present disclosure, the control system further comprises a module interface for connecting the control module and the further modules. The module interface is designed for data exchange between the control module connected to the module interface and to the further modules connected to the module interface.
Such a cargo loading system comprising a control module that is connected to a control system with a module interface makes it possible for information to be exchanged between different modules in the means of transport, which information is relevant to the cargo to be moved or to the cargo loading system, for example, as already mentioned above, information relating to the transport phase of the means of transport, for example to a flight phase or takeoff and landing phase, by way of an undercarriage module.
According to another exemplary embodiment of the present disclosure, the control system further comprises a configuration unit that is designed for configuring the control module that is connected to the control system, wherein said configuration unit is designed for configuring further modules connected to the control system.
Such a cargo loading system with a control system that comprises a configuration unit makes it possible for several modules to be able to be connected in a simple manner to the control system, which can be the central control system of the means of transport, without there being the need to specially and expensively configure each individual module.
According to another exemplary embodiment of the present disclosure, the cargo loading system further comprises a power supply unit, wherein the BUS system is designed for cross-linking the power supply unit with the at least one power drive unit and with the control module for supplying power to the at least one power drive unit and to the control module.
The power supply unit can be designed for providing a voltage, for example about 270 V, in the form of direct voltage or alternating voltage, for the at least one power drive unit.
Such a cargo loading system, connected to a power supply unit for providing a particular voltage, makes it possible for the individual components of the cargo loading system to be able to be supplied with power by means of a single voltage, rather than, as is the case in conventional cargo loading systems, with different voltages of about 115 V and about 28 V.
According to another exemplary embodiment of the present disclosure, the BUS system with the BUS, in particular with the CAN-BUS, is designed for regulating the supply of power to the control device, the control module, the control system and a maintenance system, wherein the maintenance system and the control device can form part of the cargo loading system.
The power supply unit can comprise a fuel cell and/or a battery. According to another exemplary embodiment of the present disclosure, the power supply unit is supplied with power by a generator that is driven by a turbine.
According to another exemplary embodiment of the present disclosure, the power supply unit is connected by means of a line to the BUS system or the BUS and/or directly to the BUS. In this context the term “directly” means without any interruption, for example as a result of data lines, terminals or other electrical connections or BUSES.
According to another exemplary embodiment of the present disclosure, the power supply unit is designed for the requirement-oriented supply of power to the at least one power drive unit on the basis of a control signal of the control module, which control signal is transmitted by means of the BUS system.
In other words, the at least one power drive unit or several power drive units can be supplied with power depending on their individual requirements, wherein the requirement for power can be determined by the control module in that data relating to the power requirement is transmitted, by way of the BUS system, to the control module by the power drive units or by the at least one power drive unit.
Such a cargo loading system with a requirement-oriented supply of the at least one power drive unit makes it possible, for example, to save power and thus costs, and thus ensure an efficient cargo loading system.
According to another exemplary embodiment of the present disclosure, the cargo loading system comprises a safeguard or fuse unit for monitoring the supply of power to the cargo loading system.
In this arrangement according to another exemplary embodiment the safeguard or fuse unit can comprise at least one secondary power distribution box (SPDB), a solid state power controller (SSPC) as well as a power monitoring unit.
Such a safeguard or fuse unit can be associated with an advantage in that in the case of a possible short circuit of a component of the cargo loading system the cargo loading system can be switched off, and thus the other components are not damaged.
According to another exemplary embodiment of the present disclosure, the cargo loading system further comprises a power-supply BUS system, for example a power supply, wherein the at least one power drive unit is connected to the power-supply BUS system. The power-supply BUS system is designed for the requirement-oriented supply of power to the at least one power drive unit.
Such a cargo loading system with a power-supply BUS system for the at least one power drive unit makes it possible that only one connection to the power-supply BUS needs to be established, for example from a power supply source or power supply unit, to which power-supply BUS the at least one power drive unit or several power drive units are connected, thus obviating the need to provide discrete power supply lines from the power supply source to each of the at least one power drive units or to each of the several power drive units.
According to another exemplary embodiment of the present disclosure, the cargo loading system further comprises a maintenance system for receiving and transmitting maintenance data from/to the at least one power drive unit.
The maintenance system can be connected by means of a BUS, for example an aeronautical radio incorporated (ARINC) BUS for communicating with the control system, wherein the maintenance system collects fault messages of the at least one power drive unit, or in the case of several power drive units collects fault messages for each power drive unit, for example relating to which ones of the power drive units were defective at a particular point in time. At particular points in time the maintenance system transmits the maintenance data to a base control station, which can, for example, be arranged outside the means of transport.
Such a cargo loading system with a maintenance system makes it possible for power drive units that for example have become faulty during transport to be identified and switched off.
In this arrangement, maintenance data can be transmitted that is important to the operator and that leads to maintenance action. This data is, for example, displayed on the on-board maintenance system of an aircraft.
According to another exemplary embodiment of the present disclosure, the cargo loading system further comprises a control device that is connected to the BUS system and that is designed for controlling the at least one power drive unit by means of the control module.
The control device can be a portable control panel and can be designed for transmitting and receiving control signals and maintenance data of the at least one power drive unit. The control device can carry out the function of the control module, and can transmit and receive corresponding control signals and maintenance data by way of the BUS system to and from power drive units and further connected components, for example the maintenance and control system. In this arrangement, according to another exemplary embodiment, the control device can wirelessly communicate or exchange data with the control module and/or the BUS.
Such a cargo loading system with a control device, which is, for example, portable, makes it possible for the power drive units to be able to be controlled simply and efficiently from any desirable location in the cargo compartment or outside the cargo compartment.
According to another exemplary embodiment of the present disclosure, the cargo loading system further comprises at least one proximity switch, wherein the at least one proximity switch is designed for switching on and off the at least one power drive unit on the basis of a position of cargo, which cargo can be moved by the at least one power drive unit.
In this arrangement the at least one proximity switch can be supplied with power, independently or separately of the at least one power drive unit, for example by means of a power supply unit, and consequently independent switching on and switching off of the power drive unit is ensured, even if the power supply of the power drive unit is defective. The position of the cargo relative to the fastening device, for example a cargo latch, is determined by the power drive unit and/or the proximity switch, and on the basis of this position the proximity switch switches the power drive unit on or off. For example, when the cargo is locked by means of the fastening unit, and when the power drive unit assumes a corresponding position, the power drive unit is switched off by the proximity switch on the basis of this position.
When the cargo is locked down (with the latch in the upright position) the power drive unit is switched off. When the cargo is unlocked (with the latch in the folded-down position) the power drive unit is enabled/switched on.
Any operation of the power drive unit or of the power drive units when the cargo is locked down is prevented.
According to another exemplary embodiment of the present disclosure, an aircraft comprising a cargo loading system according to any one of the exemplary embodiments described above and below is stated, wherein at least one fastening unit for holding the cargo during cargo transport through the aircraft is stated. In this arrangement the aircraft can be a passenger aircraft or a cargo aircraft.
According to another exemplary embodiment of the present disclosure, a method for loading and unloading cargo to/from a means of transport by means of a cargo loading system according to any one of the exemplary embodiments described above and below is stated, which method comprises generating a control signal for at least one power drive unit by means of a control module; transmitting of the control signal from the control module to the at least one power drive unit by means of a BUS system; and moving cargo by means of the at least one power drive unit on the basis of the control signal transmitted by means of the BUS system.
The individual features of the various exemplary embodiments can also be combined, as a result of which, in part, advantageous effects may arise which exceed the sum of the individual effects even if these effects are not expressly described.
In one example, it should be noted that features or characteristics described so far and below with regard to the means of transport comprising the cargo loading system can also be implemented in the method and vice-versa.
A person skilled in the art can gather other characteristics and advantages of the disclosure from the following description of exemplary embodiments that refers to the attached drawings, wherein the described exemplary embodiments should not be interpreted in a restrictive sense.
BRIEF DESCRIPTION OF THE DRAWINGS
The various embodiments will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and wherein:
FIG. 1 shows a diagrammatic view of a cargo loading system for a cargo compartment of a means of transport, according to an exemplary embodiment of the present disclosure.
FIG. 2 shows a diagrammatic view of a cargo loading system for a cargo compartment of a means of transport, according to another exemplary embodiment of the present disclosure.
FIG. 3 shows a diagrammatic view of an aircraft comprising a cargo loading system according to an exemplary embodiment of the present disclosure.
FIG. 4 shows a diagrammatic view of a flow chart of a method for loading and unloading cargo to/from a means of transport by means of a cargo loading system according to an exemplary embodiment of the present disclosure.
DETAILED DESCRIPTION
The following detailed description is merely exemplary in nature and is not intended to limit the present disclosure or the application and uses of the present disclosure. Furthermore, there is no intention to be bound by any theory presented in the preceding background or the following detailed description.
FIG. 1 describes a cargo loading system 100 for a cargo compartment of a means of transport with three power drive units 101 , 102 , 103 for the transport of cargo in the means of transport. The cargo loading system 100 comprises a control module 106 and a BUS system 108 with a bus 110 , wherein the power drive units 101 , 102 , 103 and the control module 106 are connected to the bus 110 by means of data lines 111 , 112 . The control module 106 is designed for generating control signals for the power drive units 101 , 102 , 103 and maintenance data of the power drive units 101 , 102 , 103 for the control and maintenance of the power drive units 101 , 102 , 103 . The BUS system 108 is designed for transmitting the control signals and maintenance data of the power drive units 101 , 102 , 103 between the control module 106 and the power drive units 101 , 102 , 103 . The bus 110 can be designed as a CAN-bus 110 . The control module 106 is designed for controlling the BUS system 108 .
A control system 130 is stated to or on which the control module 106 is connected or integrated or plugged in, wherein the control system 130 is designed for transmitting and receiving the control signals and maintenance data from the power drive units 101 , 102 , 103 by means of the control module 106 and of the BUS system 108 . The control system 130 is designed for processing the control signals and maintenance data. The control system 130 can be a hardware platform and is designed for the connection of further modules 132 , 134 , 136 that are selected from the group comprising a control system module 132 for doors, a module for supplying electrical power 134 , and an undercarriage module 136 as examples of further modules. The cargo loading system 100 is designed to be switched on and off by means of at least one of the further modules 132 , 134 , 136 on the basis of transport phases of the means of transport. Transport phases of the means of transport can, for example, be the flight phase or the takeoff and landing phase of an aircraft.
The control system 130 comprises a module interface 138 for connecting the control module 106 and the further modules 132 , 134 , 136 , for example by means of lines 137 , that are designed for data exchange between the control module 106 , which is connected to the module interface 138 , and the further modules 132 , 134 , 136 that are connected to the module interface 138 . In this way it is possible, for example, to exchange data relating to the flight phase, takeoff and landing phases as well as relating to the power supply or the undercarriage state by way of the module interface 138 between the corresponding modules 106 , 132 , 134 , 136 and thus, for example, the cargo loading system can be correspondingly switched on or off, for example when an aircraft is in flight, which complies with the requirements of regulatory authorities.
The control system 130 further comprises a configuration unit 140 for configuring the control module 106 connected to the control system 130 and for configuring further modules 132 , 134 , 136 connected to the control system 130 by means of lines or channels 142 . A power supply unit 120 is connected to the bus 110 of the BUS system 108 by means of a data line 115 , wherein the BUS system 108 is designed for networking the power supply unit 120 with the at least one power drive unit 101 , 102 , 103 and with the control module 106 for supplying power to the at least one power drive unit 101 , 102 , 103 , and to the control module 106 . The control module 106 is connected to the bus 110 by means of the data line 112 . The control module 106 can be plugged into the control system 130 , wherein the control system 130 can be connected to the bus 110 by means of the data line 112 .
Supplying power can take place in a requirement-oriented manner according to the requirements of each one of the power drive units 101 , 102 , 103 on the basis of control signals of the control module 106 , which control signals are transmitted by means of the BUS system 108 .
The cargo loading system 100 can further comprise a safeguard or fuse unit 122 for monitoring the power supply of the cargo loading system, which safeguard or fuse unit 122 is connected to the power supply unit 120 by means of a line 117 , which power supply unit can, for example, be a fuel cell or a battery and/or can be supplied with current by means of a generator driven by turbines. In this arrangement the safeguard or fuse unit 122 can comprise at least one SSPC that can be connected to an SPDB, wherein a power monitoring unit is designed for monitoring the power consumption or the supply of power to the cargo loading system 100 for monitoring each of the at least one SPDBs.
By means of a data line 114 a maintenance system 150 is connected to the bus 110 of the BUS system 108 and is designed for receiving and transmitting maintenance data of the at least one power drive unit. In this arrangement the maintenance system 150 collects fault messages of the at least one power drive unit or of each individual power drive unit 101 , 102 , 103 and can, for example, detect which power drive unit 101 , 102 , 103 was defective at a given point in time. The maintenance system 150 can transmit the data, for example wirelessly, to a base control station that can be arranged outside the means of transport.
By means of a line 113 a control device 160 is connected to the bus 110 of the BUS system 108 and is designed for controlling the power drive units 101 , 102 , 103 by means of the control module 106 . The control device 160 can be a portable control panel and can be designed for transmitting and receiving control signals and maintenance data to/from the at least one power drive unit 101 , 103 .
A proximity switch 170 , 171 , 172 is connected to each of the three power drive units 101 , 102 , 103 and is designed for switching on and off the power drive units 101 , 102 , 103 on the basis of the position of cargo that can be moved by means of the at least one power drive unit 101 , 102 , 103 . In this arrangement, each one of the proximity switches is supplied with power independently or separately of the power drive units 101 , 102 by means of the power supply unit 120 . To this effect, in the exemplary embodiment of FIG. 1 , for example, each one of the proximity switches is connected to a power-supply BUS 118 at which power is transmitted, by means of data lines 116 and 117 , from the power supply unit 120 by way of the fuse unit 122 to the power-supply BUS 118 .
FIG. 2 diagrammatically describes the cargo loading system according to FIG. 1 , except that apart from the BUS system 108 with the bus 110 for the transmission of control signals and maintenance data a power-supply BUS system 210 is provided to which several power drive units 101 , 102 , 103 , 104 , 105 are connected to nodal points 213 by means of lines 212 , wherein the power-supply BUS system 210 is supplied with power by way of a power supply line 211 that is connected to the bus 210 at a nodal point 213 . In this arrangement the power supply line 211 is connected to a safeguard unit 122 by way of which safeguard unit 122 power from a power supply unit 120 is transmitted by means of the line 117 to the power supply line 211 , if applicable depending on the requirements of the individual power drive units 101 , 102 , 103 , 104 , 105 .
In a manner that differs from that in the exemplary embodiment of FIG. 1 , in the embodiment of FIG. 2 the supply of power to the proximity switches 170 , 171 , 172 , 173 , 174 does not take place separately of the supply of power to the power drive units 101 , 102 , 103 , 104 , 105 , but instead directly by way of the respective power drive units 101 , 102 , 103 , 104 , 105 .
The BUS system 108 comprises a bus 110 to which the fuse unit 120 is connected to the node 214 by way of the line 115 , and the power drive units 101 , 102 , 103 , 104 , 105 are connected to the nodes 214 and 215 , in each case by means of a line 111 .
When compared to the exemplary embodiment of FIG. 1 , the control system 130 comprises only the control module 106 , the control system module for doors 132 , and the module for supplying electrical power 134 , wherein corresponding signals or data can be exchanged among the modules 106 , 132 , 134 by means of the module interface 138 . The configuration unit 140 is correspondingly designed for configuring the modules 106 , 132 and 134 , which are connected to or integrated in the control system 130 , by means of the channels 142 .
By means of a bus 114 , for example an aeronautical radio incorporated (ARINC) bus, the maintenance system 150 is connected directly to the control system 130 . The control system 130 is, furthermore, directly connected, by way of a bus 112 , to the nodal point 216 of the bus 110 . The control device 160 is connected to a nodal point 217 of the bus 112 by means of a line or a bus 113 .
FIG. 3 shows an aircraft 300 as an exemplary embodiment of a means of transport 300 with a cargo loading system 100 according to FIGS. 1 and/or 2 with corresponding power drive units 101 , 102 , 103 , 104 for moving cargo 304 that is held or fastened by means of the fastening unit 302 during cargo transport through the aircraft 300 .
In FIG. 4 a flow chart of a method 400 for loading and unloading cargo to/from a means of transport by means of the cargo loading system is stated, which method involves generating 401 a control signal for at least one power drive unit by means of a control module; involves transmitting 402 the control signal from the control module 106 to the at least one power drive unit by means of a BUS system; and involves moving 403 cargo by means of the at least one power drive unit on the basis of the control signal transmitted by means of the BUS system.
Although the present disclosure has been described with reference to the exemplary embodiments, various alterations and modifications can be carried out without leaving the protective scope of the present disclosure. A cargo loading system can be used both in a cargo compartment in an aircraft, and in any other means of transport, for example in rail vehicles, watercraft, spacecraft as well as in airplanes and helicopters.
In addition, it should be pointed out that “comprising” does not exclude other elements or steps, and “a” or “an” does not exclude a plural number. In particular, the cargo loading system for a cargo compartment in a means of transport can, for example, comprise more than one power drive unit, more than one control module, more than one BUS system, more than one control system, more than one power supply unit, more than one fuse unit, more than one power-supply BUS system, more than one maintenance system, more than one control device, more than one proximity switch; the control system can comprise more than one module interface, more than one configuration unit, more than one module; and the aircraft can comprise more than one cargo loading system and more than one fastening unit.
While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the present disclosure in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment, it being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope of the present disclosure as set forth in the appended claims and their legal equivalents. | A cargo loading system for a cargo compartment of a means of transport, for example a cargo aircraft or a passenger aircraft, is provided. The system includes at least one power drive unit for transporting cargo of the means of transport. The power drive unit and a control module are coupled to a BUS system. The control module generates control signals for the power drive unit and maintenance data of the power drive unit for the control and maintenance of the power drive unit. The BUS system transmits the control signals and maintenance data of the power drive unit between the control module and the power drive unit. In this manner an existing hardware platform of the means of transport can be used, and weight and cabling as well as the number of control boxes of the means of transport can be reduced. | 1 |
BACKGROUND OF THE INVENTION
Many training devices and games have been invented to motivate toddlers to learn certain desirable habits. One of the earliest of training programs is toilet training. Soon thereafter games, eating training, walking training, speaking training, learning the alphabet, etc., are to be learned by toddlers. It has long been a technique in such training to provide rewards for the toddler upon reaching certain levels of proficiency or an ultimate goal in the training. Those rewards frequently are displayed in such a fashion that the toddler is continually reminded of reaching the levels or goal and of the higher level or goal to be reached.
It is an object of this invention to provide training apparel for use in training a toddler and in providing a positive reward system for use therewith toward desired behavioral goals without any negative punishment involved in such system. It is another object of this invention to provide apparel upon which a removable reward panel can be displayed. Still other objects will become apparent from the more detailed description which follows.
BRIEF SUMMARY OF THE INVENTION
This invention relates to a toddler's training apparel having removably fastened to the front thereof a prize reward and display panel on which are attached a plurality of small figures appealable to toddlers, each such figure being covered with a small releasable patch.
In specific preferred embodiments, the panel is attached to the apparel by cooperating strips of fabric hooks and fabric loops, for example, by VELCRO brand fastener. The preferred apparel also includes an elongated tab attached at one of its sides to the waistband of the panty apparel and having a strip of fabric loops on it permitting it to alternatively be within the panty apparel or to hang outside of a pair of outer shorts or pants and to support the prize reward panel.
BRIEF DESCRIPTION OF THE DRAWINGS
The novel features believed to be characteristic of this invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and method of operation, together with further objects and advantages thereof, may best be understood by reference to the following description taken in connection with the accompanying drawings in which:
FIG. 1 is a perspective view of the panty apparel and reward panel in accord with the first embodiment of this invention;
FIG. 2 is a front elevational view thereof with the panel removed therefrom;
FIG. 3 is a perspective view of the reward panel being displayed over outer shorts;
FIG. 4 is a top plan view of the display panel of this invention;
FIG. 5 is a bottom plan view of the panel of FIG. 4;
FIG. 6 is a perspective view of the reward panel attached to a shirt apparel in accord with a second embodiment of this invention;
FIG. 7 is a top plan view of another reward panel of this invention;
FIG. 8 is a bottom plan view of an additional reward panel shown for use with the panty apparel of FIGS. 11 and 12;
FIG. 9 is a perspective view of the panty apparel and reward panel of FIG. 7 in accord with a third embodiment of this invention;
FIG. 10 is a front elevational view thereof with the panel removed therefrom;
FIG. 11 is a perspective view of the panty apparel and reward panel in accord with a fourth embodiment of this invention; and
FIG. 12 is a front elevational view thereof with the panel removed therefrom.
DETAILED DESCRIPTION OF THE INVENTION
The detailed features of this invention can best be understood by reference to the accompanying drawings. The toddler's panty apparel 11 of this invention may be any commercially available cotton training pants modified in a manner as will be described hereinafter. Panty 11 has a waistband 12 and two leg holes 13. Generally the knitting around the waistband 12 and the leg holes 13 is different from the knitting of the body of the panty so as to provide a certain elastic gathering that will make waistband 12 and leg holes 13 fit snugly around the waist and legs of the toddler. On the front of the panty 11 is a removable panel 20 which serves to hold certain reward symbols. Panel 20 and the symbols will be described in more detail below. There also is an elongated tab 15 fastened to waistband 12 and hanging downward inside panty 11, preferably retained inwardly of and by a loop shown by broken lines 15'.
In FIG. 2 panty or underpants 11 is shown with panel 20 removed and with tab 15 hanging outside of underpants 11. A vertical strip 14 is shown attached vertically on the front of panty 11, but if found desirable, strip 14 may be attached horizontally. This strip 14 is covered with fabric loops to fasten panel 20 thereto. Tab 15 is attached at one of its ends to waistband 12 and may be hung downward inside or outside of underpants 11. Strip 16 also contains fabric loops which are capable of detachably connection to fabric hooks 25 on the back side of the display panel 20. The primary purpose for tab 15 is to provide a support for panel 20 whenever outer shorts or pants are worn over underpants 11. Tab 15 is allowed to hang outside the outer shorts, and panel 20 is attached thereto as seen in FIG. 3. Of course, another display panel may also be attached via tab 15 so that two display panels may be attached to underpants 11, if desired.
In FIGS. 4-5 the details of panel 20 are depicted and preferably panel 20 is a relatively stiff fabric with a soft thread whipping 24 around the outer edges thereof. Initials 17 may be provided in the middle to represent the toddler's name. A series of Figures 18 are sewn or otherwise firmly attached to panel 20 to serve as rewards or prizes for the wearer upon reaching certain training levels or goals. The figures may be in any convenient arrangement and each FIG. 18 initially is covered with a plain, preferably colored, patch 19 sewn onto panel 20 by ordinary stitching or by a quick release type of stitching 23, e.g. basting stitch, darning stitch, tack stitch, or the like. Such stitching should be easily removed by an adult, but not easily removable by the toddler. As a reward is earned stitching 23 is removed along with its patch 19 to uncover a prize Figure 18. On the backside of panel 20, as seen in FIG. 5, there are seen threads 26 which comprise part of release stitching 23. There also is a cooperating strip 25 of fabric hooks that releasably attach to fabric loops on strip 14 or 16 to hold panel 20 in an appropriate display position. It is obvious that Figure 18 may be anything that appeals to toddlers. Shown here are figures of animals, but they may include tin toys, rattles, cartoons, bright colored patches, or any other item of interest to the wearer.
As shown in FIG. 1 panel 20 may be oriented for the toddler to see it, and in FIG. 3 for the outside world to see it, and in FIG. 6 such a panel 20 is shown being worn on a shirt apparel 27. Similarly, panel 20 could be worn on a dress, coat, jacket, pants, or any other wearing apparel. In toilet training a toddler, for example, the system would be that a clean pair of training pants or panty bearing the reward panel would be put on the toddler in the morning. Each time the toddler successfully uses the toilet, another prize Figure 18 would be uncovered by removal of a patch 19 from the panel 20. If the toddler messes up the pants, such pants and the reward panel 20 would be removed and other training pants would be put onto the toddler, but these pants would not have the capability to attach the reward panel 20. Each day, the clean training pants accepting the reward panel 20 with any already achieved prizes exposed would be placed onto the toddler. Of course, more than one panel may be needed for some toddlers for use in prolonged training. The shirt form shown in FIG. 6 may best be used for the training of proper eating habits, for example.
Illustrated in FIGS. 7, 9, and 10 is a third embodiment of the training pants 11' and panel 20' with corresponding numerals being indicative of corresponding parts. However, panel 20' is herein shown as having a generally circular configuration with the prize Figures 18 arranged in a circular fashion and with the figures being shown upright when looking from the center of such panel. In lieu of the loop strips 14 and 16, the pants 11' include two sets of spaced buttons 30 and 31 on the front of the pants 11' and tab 15 respectively. Panel 20 includes spaced buttonholes 32 which cooperate with either set of buttons 30 and 31 to removably attach panel 20' thereto. It is to be understood that buttons 30 may be located horizontally rather than vertically, if desired. Also, snap fasteners may be substituted for the buttons and buttonholes without departing from this invention.
A fourth embodiment of the training pants 11" and panel 20" is shown in FIGS. 8, 11, and 12. Panel 20" includes two pairs of spaced openings 35 and 36 through which suitable pairs of ties 37 and 38, attached to the front of pants 11", are threaded and tied in bows as shown in FIG. 11. Other pairs of ties 39 and 40 are attached to tab 15 for alternate attachment of panel 20" thereto. This embodiment may be particularly appealing to female toddlers where the ties may be of ribbon or the like.
While the invention has been described with respect to certain specific embodiments, it will be appreciated that many modifications and changes may be made by those skilled in the art without departing from the spirit of the invention. It is intended, therefore, by the appended claims to cover all such modifications and changes as fall within the true spirit and scope of the invention. | Training apparel for a toddler with awardable visual prizes available upon successfully reaching selected training stages, the apparel comprising a releasably attachable pad to be worn on the front of the apparel in the vision of the toddler and the toddler's peers and caretakers, the pad containing several figures respectively covered from view by individual releasable patches of overlying fabric. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This is a continuation-in-part of application Ser. No. 635,469, filed July 27, 1984, abandoned, which is a continuation of application Ser. No. 543,369, filed Oct. 19, 1983, abandoned.
FIELD OF THE INVENTION
This invention relates to preparation of suede leather products. A leather product is disclosed which is washable and colorfast along with a process for making the product.
BACKGROUND OF THE INVENTION
Suede products are used in the garment industry for making items of clothing. Finished suede jackets and coats, for example, are fashionable and command a high price in the market.
A major problem affecting suede products is that they are not washable in water. A finished suede product soaked in water generally becomes cracked and brittle upon drying. Moreover, suede products are not colorfast and the dye used to prepare them usually runs out after soaking, which leaves unsightly spots and ruins the garment.
It is therefore necessary to dry clean suede products. Owing to the cost and inconvenience of maintenance, the owner of a suede garment generally is careful not to wear it in the rain or in other inclement weather. This reduces the versatility of the garment. In addition, suede garments are dressy, so it is desirable to wear them for social evenings in places such as nightclubs. The heavy cigarette smoke pervading public places forces the owner to dry clean the garment after most outings.
There is need for a suede garment which is washable and colorfast in ordinary water and which will retain its luster and texture after washing. The need extends to a process for making such a washable suede product.
Another problem affecting the marketing of suede products is the high price of goatskin and kidskin suede. Because of their full grain and smoothness, they command a high price in the market. The process of this invention can obtain from less expensive sheepskin a finished product acceptable to the trade as the equivalent of kidskin, at about half the cost.
SUMMARY OF THE INVENTION
This invention provides a method for tanning an outer suede skin. The finished product can be cared for in a manner similar to a woolen sweater and can be washed in cold water and ironed at a temperature suitable for woolen products. Beginning with the starting material comprising a hide having a flesh side and an epidermis side, one embodiment of the method comprises soaking the leather in cold water for removing impurities and preservatives, applying a paste comprising quicklime, calcium hydrosulfide, and sodium sulfide to the flesh side of the hide essentially without directly contacting the epidermis side of the hide, and removing wool and the paste from the hide to dehair the hide. The hide is soaked in a first solution of sodium sulfide, after which the hide is fleshed with a fleshing machine on the flesh side.
The method continues with scalding the epidermis side of the hide by contacting its surface with a hot roller at a temperature of about 100° C. The preferred scalding step is to contact the surface with a single hot metal roller. The method continues by soaking the hide in a second solution of sodium sulfide; fleshing both sides of the hide with a fleshing machine to remove the flesh from the hide; scalding the epidermis side, as described above, by contacting the surface with the roller only once; soaking the hide in a third solution of sodium sulfide; and fleshing again. The hide is then neutralized by rinsing it in water until all traces of alkalinity have been essentially eliminated.
The hide is then bated with a bating agent, after which the fleshing step can be repeated. The hide is pretanned by tumbling in a pretanning bath containing formaldehyde. Sodium bicarbonate is added to the formaldehyde-containing pretanning bath to fix the hide, and the hide is removed from the bath and allowed to drip essentially without folding.
The hide is tanned by tumbling the hide in a tanning bath containing chromium sulfate in a concentration of up to about 2% of the weight of the hide, after which the hide is allowed to drip again essentially without folding. The hide is neutralized by soaking the hide in a neutralizing bath containing sodium sulfate, followed by drip drying the hide essentially without folding.
The method continues with fulling the hide by dampening the hide and spinning the hide until uniformly damp, shaving the hide on the epidermis side, soaking the hide in a solution containing ammonium sulfate, and degreasing the hide by washing with a soap.
The hide is ammonia treated and them tumbled in a dyeing bath containing a direct color dye at a temperature from about 158° F. to about 176° F. until the dye is absorbed, after which the hide is soaked in a solution containing chromium sulfate and allowed to drip. The hide is buffed to a smooth texture to complete the process. The method continues by greasing the hide with egg yolk, soaking it in hot water, and buffing to a smooth texture to complete the process.
DESCRIPTION OF THE DRAWING
These and other aspects of the invention are best understood by referring to the following detailed description and the accompanying drawing which is a flow diagram illustrating a process for preparing an outer suede product according to principles of this invention.
DETAILED DESCRIPTION
Hides 10 from a slaughterhouse or the like are received and washed at 12 by soaking in cold water for 48 hours in a rotatable drum or in a mill. At the end of 48 hours, the hides are rinsed thoroughly to eliminate any residual blood or other impurities. During later steps in the presently preferred process, the hides will be soaked in a sodium sulfide solution. Any residual blood or foreign matter should be removed during washing or it could later stain the hide.
Hides received from a slaughterhouse usually are stained with blood or other impurities, and have been temporarily preserved with salts and other substances. The preliminary soaking in water eliminates any impurities which may have adhered to the hide or to the flesh, and also eliminates the substances used for preserving the hides. During soaking, the water temperature should be about 50° F. to about 60° F. If the hides are very dirty, the cleansing process can be improved by changing the water after about 12 hours of soaking.
During soaking, the hides absorb a quantity of water almost equal to their dry weight. This causes the hides to inflate and increases the softness of the hides.
Hides received from a slaughterhouse are typically either dried hides, fresh salted hides, or dry salted hides. Dried hides have been left out to dry, often in direct sunlight. Dried hides are rigid because their liquids have evaporated and the albuminoid matter in them has solidified, which binds the skin fibers together as if they were cement. When the drying process has been too violent, for example in direct sunlight, collagens in the hide are affected and resist reabsorption of water. To properly soak dried hides, the skin fibers ideally are given back the water they lost in order to restore the albuminoid matter to the state it was in when the hide was fresh, i.e., when the hide was flayed. The hotter and the brighter it was when the hide was dried, the more difficult it will be to cause it to absorb the necessary quantity of water. However, a 48 hour period of initial immersion in fresh water usually suffices to cleanse and soften most dried hides.
Fresh salted and dry salted hides have to be washed thoroughly to eliminate the salt(s) used in preservation. As salt is a form of antiseptic, the washing must be complete in order that the hide becomes essentially salt free. Any salt which remains could delay the action of the micro-organisms present in the hide which assist in a subsequent dehairing step 15. Since salt has dehydrating properties, the dermis of the hide will not inflate until the water has penetrated thoroughly and eliminated the salt. Hence inflation of the hide can be used to check the progress of salt elimination.
By soaking the hides in a rotatable drum, and by rotating the drum occassionally, the fibers in the hides are loosened, they fill with water and are soon completely soaked. For tough and relatively impenetrable hides, the drum can be rotated intermittently to speed up the washing process. However, the hides should not be soaked in water more than about 48 hours, because there is a risk that the hides will ferment to an undesirable extent with longer periods of immersion.
Animal hides contain an outside layer which is commonly referred to as the "epidermis" side, and an inside layer called the "flesh" side. The outer finished layer of most conventional leather products originates from the flesh side of the hide and is referred to as suede. The process of this invention has the advantage of being flexible, in the sense that the outer layer of the finished product can originate from either side of the hide.
After the washing step 12, the hides are rinsed and dehaired at 15. A flat surface or table is covered with a sheet of plastic and the hide is placed on it with its flesh side uppermost. A liming paste 16 is spread homogeneously with a spatula or other suitable tool over only the flesh surface of the hide. In order to recover the wool from the hide, the paste is not allowed to touch the epidermis side of the hide. The hides are then rolled up with the plastic sheet and covered with a moist canvas and allowed to sit for a day. At the end of one day, the wool or hair should come out easily from the hide when pulled by the fingers. If not, the paste should be left on for sufficient time to loosen the wool. The simplest way to remove the paste and the wool is to dehair the hides with a dehairing machine, and the paste and wool should come off easily.
The presently preferred paste used for dehairing is a compound comprising quicklime, calcium hydrosulfide, and sodium sulfide. In one preferred embodiment of such a paste, 100 grams quicklime is mixed with 150 grams calcium hydrosulfide, in one liter of water. Additional water is added as needed to obtain a paste of creamy consistency. The sulfide present should be limited to a concentration of at most one percent in the paste.
The exposure to the liming paste 16 keeps the leather soft while liquefying the root of the hair follicles so that the hair or wool can be removed easily. In addition, the flesh layer also begins to loosen from the hide.
The element sulfur present in calcium hydrosulfide and sodium sulfide in the paste liquefies collagens situated between fibers in the hide. The sulfide permits the paste chemicals to pass through the dermis layer to reach the follicle bases. Without the presence of sulfide in the paste, the epidermis side of the hide would resist chemical attack during later processing steps.
The paste described is particularly useful because the dehairing step takes only about one day to perform. In previous conventional processes, hides were soaked in vats in caustic lime solutions which helped develop the natural micro-organisms in the hide to loosen the wool. However, these processes generally required a week's time before the wool was removed. As much as five days processing time over such known processes can be gained by using the paste liming 16 as described.
Moreover, in processes where the hide is soaked in a lime solution, the lime solution contacts both sides of the hide and dissolves the wool. In contrast, in a presently preferred process of the present invention, the paste is not permitted to touch the epidermis side of the hides so that the wool can be recovered and sold as a useful product.
The wool can be taken from the hide with a sharp bladed curved knife or with a conventional depilating machine. After removing the wool and the paste, the hides are thoroughly rinsed at 16 in cold water, preferably in a conventional rotatable drum having a screen door on the circumference of the drum on the circumference of the drum. The perforations in the screen allow rinse water to be ejected from the drum, while fresh water is added to the rotating drum through a pipe leading to the center of the drum. In a typical rinsing operation, sufficient water is added continuously to the drum to balance the removal of rinse water. After rinsing, the hide is dripped at 17 by putting it on a stool or other hanger to drip off excess water. After the dripping step, the hide is weighed and the weight is noted as a reference for the following steps.
The hides are soaked at 18 in a sodium sulfide solution to prepare them for fleshing. The sodium sulfide begins to liquefy collagens so that they can be removed during fleshing. Two and one-half liters of water per kilogram of hide are added into a hermetically sealable drum along with a solution of decanted sodium sulfide (previously well dissolved in boiling water) to obtain a concentration of about 1.2 g/cc. The hides are placed in the drum and the drum is turned for two hours, after which the hides are left to soak in the drum for an additional ten to twelve hours, ensuring that they are well immersed in the solution. Before the hides are removed from the drum, the drum is turned several times. Without draining the soaking solution, additional water at room temperature is added to the drum. The drum is rotated for about one minute during which time care is taken not to deflate the hides.
The sodium sulfide used in the soaking step 18 is preferably prepared from cresol and decanted to remove particles from the activated carbon which was used as the cresol carrier. It is important to get a mineral separation of sodium sulfide from the particles of activated carbon or else such particles could stain the leather during later steps.
The hides are now ready for a first fleshing step 20. A conventional fleshing machine can be used for this procedure. Such a machine is well known to those skilled in the art of tanning leather and comprises a pair of closely spaced parallel rollers. One of the rollers has helical blades affixed to its outer surface, while the other roller is a rubber coated right circular cylinder. The clearance between the rollers can be adjusted so that the rollers can be pressed tightly together. The hides are inserted between the rollers and the rollers are pressed together to squeeze the hides. During this "fleshing" step, substances liquefied by the immersion in the solution of sodium sulfide at 18 are removed. The initial fleshing step is carried out on the flesh side only, i.e., only the flesh side contacts the bladed roller, while the epidermis side contacts the rubber coated roller. The flesh is loosened from the hide during this step.
After the first fleshing step, the hide is scalded at 22 by placing it on a table and running a single hot metal roller 23 over its epidermis side. The hot roller preferably comprises a hollow right circular cylindrical roller having gas flame burners. The flame is directed inwardly along the interior longitudinal axis of the roller from one of its end faces. The roller should be prepared by heating to a temperature of about 100° C. for about twenty minutes before using it. The roller is passed quickly three times over the epidermis side of the hide at about 10 cm/sec. No portion of the hide should be permitted to stick to the roller, although the roller contacts the hide surface while passing over it. The table under the roller can be protected from heat by providing a fine coat of asbestos (amianthus) on its upper surface.
As a result of these thermal treatments, the burnt thickness of the fibrous grain layer surface in its swelling state ranges from about 0.5 to about 1.5 mm. In essence, the fibrous grain layer is completely thermally eliminated. The useful finished velvet surface, commonly called "suede", originates from the flesh side of the hide. In the present process, the useful finished smooth texture surface called "outer suede" originates from the upper surface of the corium layer, once the fibrous grain layer has been eliminated.
The scalding operation facilitates removal of the epidermis without affecting the corium layer of the hide, and it permits better penetration of dye into the hide during a subsequent dyeing step at 64.
To prepare the drum for further soaking of the hides at 26, a sodium sulfide solution having a density of about 1.0 g/cc at room temperature in a proportion of about 21/2 liters of water per kilogram of hide is placed in the drum. The sodium sulfide in this solution should also be decanted from cresol with the particles of activated carbon removed. The hides are placed in the drum and allowed to soak for about 12 hours after drum rotation during the first minute of soaking. During this time, the drum should be turned from time to time as needed for uniform soaking of the hide.
If the hide at this point is greasy, as for example, for ram or sheep hides, the hides are allowed to sit in the drum for an additional two to three hours and the drum is rotated slowly (at about 8-12 revolutions per minute) for the initial three hours of the soaking. On the other hand, for hides which are not greasy, rotation during the initial minute of soaking is sufficient.
After the hides are soaked, the solution is removed from the drum and the skins are rinsed briefly at 27, for about 30 seconds, with clean room temperature water. A second fleshing step 28 is then performed on the hides, this time on both the flesh and epidermis sides. During the second fleshing step, the fleshing machine rollers are tightened sufficiently to ensure that the flesh is removed essentially completely from the hide. A thorough elimination of flesh makes the hide more uniform in thickness, which best prepares the hide for a later shaving step at 56 performed after the hide has been chrome tanned.
The fleshing mechanically cleanses the inside of the hide in the manner of a laxative. Many collagens in the hide come out with fleshing. The previous scalding step 22, which burned the epidermis, facilitates removal of the fibrous grain layer during the second fleshing.
In a second scalding step 29, the hot roller is passed over the epidermis sides only once. A one gm/cm 3 sodium sulfide soaking solution is prepared, as described above, and the sides are soaked in it at 30. The drum is rotated for 20 minutes and the hides are left in the solution for a further 10 to 12 hours without rotating the drum during this time. The hides are then rinsed at 31 for about 15 minutes after adding water. A third fleshing step 32 is then carried out on both the flesh and outer side of the skin. The third fleshing step eliminates as much as possible the shreds of flesh left after flaying. The fleshing step is carried out thoroughly in order to facilitate subsequent processing.
After the third fleshing step 32, the hide is deflated at 33. The hide is placed in the drum having the perforated door and is rinsed with water at room temperature, tumbling for about 30 to 40 minutes. New water is added to the drum at a rate which is sufficient to compensate the draining of old water through the perforated door. During rinsing, the drum is rotated, which helps to deflate the hides. The purpose of deflating the hides is to remove the water and sulfide which previously had inflated the hides. The purpose for soaking the hides in the sodium sulfide solutions at 18, 16 and 30 was to liquefy the collagens so that they would be removed by mechanically purging them from the hide during the fleshing steps. If at the end of about 30 to 40 minutes, the hides are not deflated, the rinsing and tumbling is to continue with fresh water at room temperature until deflation occurs.
The hides are next neutralized at 34 to remove all traces of lime. The hides are placed in a drum having a neutralizing bath of warm water at about 100° F. to 102° F. The drum has a hermetically sealed door. The hides are spun and the pH of the hides is checked. For this purpose, a slit can be cut near the head of a hide and the pH checked by inserting indicator solution, such as phenolphthalein, or checked by acetic acid, or litmus papers, in the slit. If there is any indication of alkalinity, a new neutralizing bath of warm water at about 100° F. to 102° F. is prepared and the wash repeated until all traces of alkalinity have been eliminated from the hides. It is necessary to remove all traces of lime from the hides before proceeding.
After the lime has been eliminated in the neutralizing bath, the hides are ready for a bating step 35 which removes all remaining nonfiber type materials from the hide, such as albuminoids and certain collagens. Any conventional bating or macerating agent, which are well-known to those skilled in the art, can be used in a proportion of about two percent agent per weight of the hides. Such agents typically contain bacteria and enzymes. This is why all traces of lime should have been removed before contacting the hide with the bating agent, because lime can interfere with the activity of bacteria and enzymes.
The hides, preferably still warm from the neutralizing bath, are weighed for reference purposes and warm water at about 102° F. to about 104° F. is placed in a hermetically sealable drum in an abundance of no greater than about three liters of water per kilogram of hide. Sufficient bating agent to make up a solution containing about two percent agent per kilogram of hide is mixed in the water. The hides are added and the drum is rotated for an initial half hour, after which time the hides are allowed to steep in the bating solution for an additional 7 to 8 hours. It is advisable to turn the drum once during the bating time. The bating step 35 is finished when the skin of the hide is sticky to the touch.
The bating is preferably carried out in a temperature range of about 100.4° F. to about 102.2° F. The temperature of the water in the drum before the hides are added, about 102.2° F. to about 104° F., is made slightly higher than the preferred range for bating so that the overall temperature of the solution, when the hides have contacted the solution, will be in the preferred range. The solution temperature should be maintained by gentle heating so that the temperature of the hides in the bating solution is not permitted to drop below about 95° F. The preferred range of temperature encourages the bacteria and enzymes in conventional bating agents to function optimally. At such temperatures, the most favorable conditions for bacterial enzymes to act on elastic skin fibers are typically between a pH of about 7.5 and about 8.5. Such conditions can be readily obtained in solutions containing about two percent concentration of conventional bating agents.
After the hides have soaked in the bating solution, the agent is eliminated from the drum and the hides are briefly rinsed in lukewarm water at 36 in a range of about 80° F. to about 100° F.
At this point the quality of the finished product can be improved if an optional fourth fleshing step 37 is performed on both sides of the hides. Most conventional bating agents contain a sawdust which will be eliminated by such an optional fleshing step. Under the pressure of the fleshing machine rollers, the pores in the hide are forced open and certain substances, which have now been loosened, are eliminated. Such unwanted substances, for example, include insoluble lime, fats partially transformed into calcareous soaps and rendered easily emulsionable, and albuminoid substances which have become soluble as a result of the action of the lining paste 16 and sodium sulfide. In effect, the extra fleshing step 37 causes the hides to undergo a slight mechanical purge.
At the end of the fourth fleshing step 37, the hide consists essentially of fibers. Collagens and albuminoids have been essentially removed at this point.
After bating, the hide is pretanned at 38 in a formaldehyde solution. The purpose of this step is to tan the yellow tissue in the hide and make it nonputrifiable. The pretanning step also breaks white fibers into smaller units which, during a later dyeing step at 64, facilitates complete penetration of the dye.
The hides are pretanned by rinsing in lukewarm water, dripped well and weighed for reference purposes. The dripping should not be carried to a point of complete dryness but the weighing should be made on the basis of a well dripped hide. A drum is filled with warm tepid water, about 95° F. to about 102° F., in a quantity of about three liters water for kilogram of dripped hide. The hides are soaked in water and during rotation of the drum, about five grams formaldehyde at 40° Baume per kilogram of hide are added through the hollow axis pipe of the hermetically sealed drum. The drum is rotated about 45 minutes.
After the 45 minutes of drum rotation, a solution of sodium biocarbonate at half the total concentration of the formaldehyde is added at 40. Initially sodium bicarbonate on the basis of 2.5 grams bicarbonate per kologram of hides is added to the pretanning solution of formaldehyde in three 15 minute intervals. For instance, in 100 kg of dripped hide, the total dosage of sodium bicarbonate is 250 grams. The first installment of bicarbonate is added about 15 minutes after the last installment of formaldehyde was added. The sodium bicarbonate neutralizes the formaldehyde pretanning agent and fixes its activity.
The drum is rotated at about 7 to 8 r.p.m. while the hide is soaking in the solution containing both formaldehyde and sodium bicarbonate. The drum is rotated for several hours until a point is reached where, when the leather is tested by folding it and squeezing it tightly between the thumb and index finger, it has become whiter and drier. This result demonstrates that swelling water has been forced out of the fibers. At this point, the hides are removed from the drum and placed on a stool without folding. They are left to drip at 42, avoiding complete drying, which takes about one to three days. It is important for the hides to drip without folding. Folds are undesirable because it will be difficult to later remove any folds formed in this step.
The sodium bicarbonate was added to the pretanning solution as a neutralizing agent to limit or fix the activity of formaldehyde. If the tanning action of formaldehyde were allowed to proceed indefinitely, it would eventually weaken certain fibers and result in an inferior product. While it is desired to limit the extent of formaldehyde tanning, it is also desired to avoid chemically affecting those formaldehyde species which have at that point combined with the fibers. A good neutralizing agent is a salt derived from a strong base and a weak acid, for the weaker the acid, the stronger will salt hydrolysis be. Sodium bicarbonate is the preferred neutralizing agent. Even if an excess of sodium bicarbonate is used, it maintains its equilibrium so that neutralization occurs uniformly. Sodium bicarbonate also causes a slight enlargement of fibers which are to be chrome tanned, which additionally assists the tanning process.
After pretanning with formaldehyde and fixing with sodium bicarbonate, the hides are chrome tanned at 44 in a basic chromium solution and neutralized at 46 in a sodium sulfate solution. A drum, which should be provided with flights for tumbling the hides, is filled with warm water, about 77° F. to about 86° F. (25° C. to 30° C.), in an abundance of about four liters of water per kilogram of hide, weighed during the previous reference--weighing step, prior to the pretanning step. The hides are placed in the drum. A "basic chrome" tanning solution is previously well dissolved in warm water and comprises decanted basic chrome in a proportion of two percent to the weight of the hides. The weight referred to is the hide weight which resulted after the bating step, i.e., before the pretanning step with formaldehyde. It is important to provide at least four liters of water per kilogram of leather as it is critical that the chrome tanning step 44 be performed in a relatively low concentration of chrome (at most about 2%) in order to effect a slow process of chrome diffusion into the hide.
The drum is rotated at about 5-8 revolutions per minute and one half of the basic chrome solution is poured slowly into the drum. The chrome solution should be added slowly so that it is absorbed by the rotating water as it is introduced into the drum. It is important to keep the local concentration of chromium low, at no more than about two percent of the weight of the hides, so that slow diffusion of chromium into the hides will occur. If chromium is added too quickly, it can form extensive chromium-fiber complexes with the outer surfaces of the hide which can hinder diffusion of the dye during a later dyeing step at 64. There should be at least four liters of water per kilogram of leather present in the drum. If insufficient water is present, the leather can become sharp, bitter, and rough. It would then be necessary to repeat the tanning step 44 with sufficient water and new but dilute the basic chrome solution.
The basic chrome solution should be added in two installments over a period of about three hours, or more. By maintaining the water temperature at about 25° C. to about 30° C., the fibers open sufficiently to accept the chromium. The hides are allowed to steep in the basic chrome tanning solution until the chrome is absorbed. This can be determined when the solution turns a markedly paler color, indicating complete absorption of chrome.
During the time the hides are steeping in the chrome tanning solution, one should check that the hides do not bind or twist together. If this occurs, it is possible that diffusion of the chromium tanning agent into portions of the hides could be blocked, in which case the hides should be untwisted. To minimize such a problem, the tanning drum can be provided with flights to tumble the hides slowly, which discourages the hides from twisting together and exposes their full surfaces to the tanning solution.
When the chrome has been absorbed into the hides, the hides are removed from the drum and placed on a stool or other surface to allow dripping at 45 while avoiding folding. Any folding during dripping could cause eventual spotting or discoloration of the finished product.
The following day, the hides are weighed and placed in a neutralizing bath at 46 in a drum which contains a sodium sulfate solution in a proportion of about 10 percent, but no more than about 10 percent, sodium sulfate to the weight of the chrome tanned hides. The concentration of the solution is about one-half liter of water per kilogram of hides. The drum is rotated for about 10 to 15 minutes and the hides are removed and permitted to drip-dry at 47 for up to about 24 hours again avoiding folds. After dripping, the hides are allowed to hang vertically until dry, after which time the hides can be stored on the ground for several days.
The hides are soaked in sodium sulfate at 46 to deacidify the hides and enable the chrome tanned hides to be dyed at 64 in a neutral solution. This operation is essential because sodium sulfate, being hydroscopic, enables the hide to absorb water easily through the proteic fibers and inter-fibrillar spaces which have been closed during the drip-drying step 47. Ideally, a hide should be neutralized at 46 at a relatively low pH, at most about 7, to eliminate free acids present in the hides without contaminating the basic chrome species which have bonded to the proteins in the hide. In this regard, an excess of hydroxylic ions during neutralization would be damaging as it would tend to dissociate chromium from the hide and make the chrome tanning process unstable. To avoid possible reactions of this type alkalinity in any neutralizing bath should be kept as low as possible, because if neutralizing anions are permitted to enter the coordinated chrome-fiber complexes they would tend to destabilize the tanning process.
After chrome tanning, the leather contains free and combined acids in various forms. For example, such free acids can be expected to have formed as a result of direct hydrolysis of chromium salts. Such combined acids typically would be those hydrolytically bonded to protein, or found in chrome-cationic complexes. If neutralization is taken too far, for example with a neutralizing bath of more than about 7 pH, neutralization may bring about a change in the chromium species bonded with fibers and result in partial detanning.
It is therefore important not to increase the alkalinity of the chrome bonded to the fibers, which can be prevented by keeping the hydroxylic ion concentration low in the neutralizing bath. This is why sodium sulfate is the preferred neutralizing agent for tanning with chromium sulfate. If the neutralization step 46 is carried out carelessly, it is possible to spot the color when the hide is exposed to dye in a later step. However, such an undesirable result can be avoided by limiting the concentration of sodium sulfate in the neutralizing bath, as an upper limit, to about 10 percent of the weight of the hides.
It is possible to use sodium chloride as the neutralizing agent for chrome tanning because it, like sodium sulfate, is also deacidifying and hydroscopic. However, the use of sodium chloride is not presently preferred because it does not reinforce the tanning action of chrome as well as does sodium sulfate.
A vat is filled with cold or room temperature water, and the hides are immersed in it at 48 one at a time for about two to four seconds per hide. The hides are then placed on a pile on the ground and allowed to sit for 2 to 3 hours, covered with a moist canvas. The hides are somewhat impervious upon immersion. The residual water on the hides soaks in very slowly. After several hours, however, the soaking has proceeded satisfactorily. The hides are then spun in a drum until they are fulled, i.e., made uniformly moist and soft. Just enough water, if necessary, should be added to the drum to only dampen the hide and not wet it. The hides are tumbled preferably for about 30 minutes at about 8-15 r.p.m. The hides are then placed in a pile on the ground, covered with a moist canvas.
If, after fulling the hides, the hides are not sufficiently soft, the hides can be further softened while still moist by staking the hides at 52 on a conventional lapping wheel. Lapping should be performed only on the flesh side of the hide. The lapping blades or flights lodge into the hides and loosen the skin fibers. This stretches the hides and opens up the fibers, softening the hides.
To remove any residual shreds of flesh which might otherwise pinch the chamois on the epidermis side, the hides are buffed at 54 while still moist on the flesh side. A high speed 180 r.p.m. buffing machine, with 200 or higher grade carborundum powder sprinkled on the glued surface of the wheel, produces a velvet smooth short fiber hide.
The leather of most hides does not have a uniform thickness as it is originally thicker on the rump and on the buttocks of the animal than on the flanks. To make the leather uniformly thick, the leather is preferably shaved at 56 while still moist, on the epidermis side only from head to tail with a lapping machine using a very fine grade abrasive. If the hide is not moist, it should be moistened by dampening it and spinning it as described in the fulling step 50. The hide is shaved as necessary to give the leather a uniform thickness. During this operation, a small portion of the chrome complexes on the surface of the hide is removed. However, these complexes are replaced in a later soaking step at 68.
At this point, the hide contains formalin and chromium salts which, if permitted to act on the hides indefinitely, would eventually weaken the leather. To neutralize such salts, the hides are soaked at 58 in a lukewarm solution, about 85° F. to about 95° F., adding through the axis pipe the six percent ammonium sulfate per hide weight. The hides are spun for one-half hour in the solution. To calculate the correct weight of the hides, the drip-dried weight of the hides after the shaving step 56 is used. After soaking the hides in the lukewarm ammonium sulfate solution, the hides are rinsed at 59 and checked with an indicator solution for any remaining acidity. Should such a litmus test still indicate acidity, the hides should be washed thoroughly again in lukewarm water. After rinsing the hides, they are hung vertically and are allowed to drip-dry at 60 for several days.
After drip-drying the hides, they are degreased at 61 by placing them in a drum with lukewarm water, about 85° F. to about 95° F., with about three liters of water per kilogram of hide. Liquid soap, in a concentration of about two to three percent of the hide weight, is added to the water. The hides are rotated for a half an hour or more, after which time the hides are rinsed well in a drum with a screen door. At this point the hides are somewhat lighter than they were just prior to the soaking in the ammonium sulfate solution at 58 since some grease has been removed from the hide. It is possible to measure how much grease is removed by weighing the difference. This difference in weight serves as an upper limit for the weight of the dye to be added to the leather during the subsequent first dyeing step.
The hides should be degreased or it is possible to spot the skin. The weight of the grease removed should later be compensated by the dye. Any detergent which can be used for washing woolens is suitable for degreasing the hides. Suitable detergent products for degreasing the hides are thepol, soflan, soilax or elan, which are commonly used to wash woolens.
The hides are then placed in hot water at 62 (approximately 140° F. to 158° F.) contained in a drum in a proportion of about six liters per kilogram of well drip-dried hide. An ammonia treatment at 63 is then carried out by adding ammonia at 21/2 percent of the volume of water or 15 grams of liquid ammonia in six liters of water per kilogram of hide. The hides are rotated in the drum for about one-half hour or more while preparing the dye. Upon completion of the tumbling step, the hides are washed in the first washing step in abundant water, using the perforated door to eliminate all traces of ammonia. The second washing step is used with hot water (140° F. to 158° F.), rotating for two minutes so that the hides become warm. Next the hides are removed and allowed to drip and then placed back in the drum while they are still warm.
At this point the hides are next dyed in a dyeing step 64. A direct color dye is prepared in a proportion of about 21/2 percent dye to weight of well drip-dried hide, in four liters of water per kilogram of hide. For example, to prepare a dye bath for a total hide weight of 10 kilograms, one kilogram of dye is added to 20 liters of hot water and simmered for 10 minutes. Half of this solution (10 liters) is diluted in 20 liters of warm water at a temperature of 158° F. to 176° F. to obtain a solution of 30 liters of water and 500 grams of color dye. This solution is poured very slowly into a rotation sealable drum with a funnel through the hollow axis pipe.
The dye used is preferably a direct color dye. Suitable direct color dyes can comprise folloni colors or other acid colors which operate in a neutral bath. Folloni colors are commonly used to dye wools, nylons or animal fibers. The dyeing process 64 is performed under the conditions of hot water and a neutral bath. It is believed that direct color dyes penetrate completely inside the fiber, and, once there, they are prevented from leaving by the chromium-fiber complexes fixed from the tanning steps 44 and 46.
The drum should have flights or pegs and be spun at about 14 r.p.m. so that the hides will intermittently fall from the top of the drum due to the action of gravity and the flights. After about 20 to 30 minutes of rotating the hides in the dyeing solution, the hides are checked to determine whether the dye has been absorbed. The hides are rotated as needed until complete absorption of the dye occurs. To check the extent of absorption, the head of the skin can be cut with a blade and visually examined to insure that the dye has penetrated completely from the flesh side through to the epidermis side. When this happens, the dye water is discarded.
Upon complete absorption of the first half portion of the dye into the hides, the drum is rotated while the other half of the dye solution (10 liters) is added to the drum very slowly, keeping the temperature always in the range between about 158° F. to about 176° F. After another 20 to 30 minutes the hides are checked again for complete absorption of the rest of the dye, and, if necessary, rotation of the hides in the dye is continued until complete absorption occurs. It is necessary to wait until the dye bath is cooler before discarding the dye and rinsing the hides. When this happens, the dye water is discarded and the hides are rinsed at 66 in cold running water.
The best results are obtained when the temperature of the dyeing bath is maintained in the range between about 158° F. to about 176° F. Temperatures above about 178° F. allow the dye to penetrate too quickly into the surface layers of the hide and will hinder deeper diffusion of the dye. Temperatures below about 158° F. cause the dyeing process to slow down considerably. As temperature falls below about 158° F., a point can be reached when the hide will no longer accept the dye.
The drum should be rotated at a sufficient speed, preferably about 14 r.p.m., so that the hides will fall intermittently from the top of the drum and not become bunched and twisted together. The drum should have a diameter of at least 300 centimeters to cause lifting and falling of the hides which helps open up the fibers in the hides to accept the dye. The width of the drum should be less than the diameter of the drum. With the temperature maintained in the hot water range between about 158° F. and about 176° F., the fibers open, the dye responds to the temperature, and the color gets inside the hide.
The previous shaving step 56 which involved the outer surface of the hide, not only produced a leather of uniform thickness, but also improved the absorption of dye inside the fibers of the hide.
In order to establish the saturation point of the dye in the hide, i.e., to determine how much more dye can be added in order to achieve a particular shade, an initial dose of dye is tested. The initial dose is in the proportion of three percent of the weight of the hide, for example, 30 grams dye in four liters of water per kilogram of hide. After processing the sample as described for the first half of the dyeing step, the sample can be dried and the shade checked. If the color is too faint, the operation can be repeated with double the amount of dye, that is, six percent of the weight of the hide, using 60 grams of dye in four liters of water per kilogram of hide.
After dyeing, the hides are soaked once again at 68 in a solution of basic chrome. The hides are placed back in a drum and a new solution of the basic chrome used for the tanning step 44 is prepared. Such a solution has a concentration of basic chrome in about 0.5 percent per kilogram of hide, the referenced weight being the weight prior to the degreasing treatment 62. The drum is rotated and the chrome solution is poured in gradually in three installments at five minute intervals. When the solution pales, indicating that chromium has been absorbed completely into the hides, the hides are removed from the drum and allowed to drip well at 70 completely on a stool.
The prior step of moist shaving 56 after the chrome tanning step 44 removed some chromium complexes and would eventually cause the tanned fibers to fade. The step of soaking at 68 in the basic chrome tanning solution after dyeing replaces the layer of chrome which was removed by the shaving step 56. This additional soaking in a chromium sulfate solution after the dyeing step 64 prevents the running or fading of color from the finished product.
The next day, the hides are weighed and placed in the drum. An egg yolk greasing step 72 is then carried out. Four percent per kilogram of egg yolk is dissolved in tepid water. This mixture is placed in the drum filled with hides and one-half liter of water per kilogram of hide at 77° F. The drum is rotated for 15 minutes and the hides are then hung to dry at 74. When dried, the hides are left in place for a few days. Next, two liters of water per kilogram of hide are placed in a container to soak the hides for about 20 minutes at 76. When completed, the hides are hung to dry at 78 for approximately three to four days.
Greasing smoothens the chamois. Other known tanneries in the world lime hides in pits, but the advantage of this rapid sulfide process is that the hides do not stay in the solution very long, so that the internal part is not affected. After heat removal of the outer stratum and the shaving off of the second stratum of epidermis, the dermis is unharmed and has no horny or resistant substances.
The hides require the egg yolk greasing treatment to obtain the slackening of fibers and a good resistance. The egg yolk treatment is made from an abuminoid substance containing an emulsifying oil which produces a light tan. This fatty matter in its state of emulsion penetrates easily, lubricates the fibers and softens the leather, making it smooth to the touch. It has been observed that the dyed hides, greased with egg yolk, become soaped-water washable and do not loosen the color penetrated inside the conjunctive white fibers through the amorphous areas. This is obtained by coagulating the albuminoid substances contained in the egg yolk which become insoluble with the high temperature.
A second dyeing method 80 consists of the following steps. A dye is prepared with the same amounts that were used for the first dyeing step. The hides are weighed before placing the hides in the drum. The water is heated to approximately 140° F. to 160° F. The water is eliminated without letting the hides cool. The drum is rotated and half the prepared dye is added slowly with a funnel through the tube while the drum is rotating. After 20 to 30 minutes of rotation of the drum, the hides are checked to see whether the dye has been absorbed. If all the dye appears to be absorbed, then the dye may be discarded. The drum is started rotating again, and the other half of the dye is added as before, without putting in any more water. After 20 to 30 minutes of rotation in the drum, the hides are checked to see whether the dye has absorbed. If necessary, the drum is continued turning until all the dye has been absorbed. To ensure that the dye has penetrated from one side of the skin to the other, the head or legs can be cut with a blade. Another indication of the degree of absorption is by comparison of the dye water with the prepared dye. When this step is completed, the rinsing water at 82 is discarded and the hides are placed back into the drum with a small amount of water. A basic chrome solution is prepared for soaking at 84. The chrome solution is in a proportion of two percent per kilogram of hide. The drum is turned again and the chrome solution is added to the drum with a funnel in two installments at five minute intervals. The hides are checked to see whether the chrome has been absorbed. The hides are rinsed at 86 and hung up to dry at 88. As a result of this second dyeing treatment, without subsequent greasing, the color becomes bright, intense and resistant to washing with soap suitable for woolens.
The color combines with the basic color without precipitation. Inasmuch as the skin is permeable, penetration of the dye is facilitated by high speed drumming and waterless dye.
Permeability is due to pretanning with formalin, which splits the fibers and allows in-depth dyeing. Guaranteed washability is only obtained if the dye penetrates deeply.
After drying completely, the hides are moistened, drummed and polished as follows. The hides are placed in slightly damp sawdust overnight at 90. The next morning, the hides are rotated in the drum at 92 for a few minutes. Before these operations, the fibers are momentarily plastered down onto the hide, but the moisture combines with the tractive effect of drumming to raise them easily. Practice is necessary to attain the correct degree of humidity. If the hides are not moist enough, stretching on the felt roller in the subsequent polishing step 94 is laborious. The ideal degree is that which enables the hide to dry with the heat produced by the felt roller on which the hides are to be polished. The best method is to put the necessary amount of sawdust into the drum, then add water to the drum until the humidity is thoroughly distributed. Stop the drum and squeeze a sample of sawdust in the palm of the hand. When the hand opens, the sawdust should just cling together, without wetting the hand. If insufficient water has been added, put in more wet sawdust. In the opposite case, put in more dry sawdust. When the proper degree of moisture has been reached, lay the hides in pairs, flesh sides together, with the layers of damp sawdust between each pair, forming piles about 18 inches high.
The hides are then left overnight. In the morning, they will be ready for drumming. This moistening operation requires practice and care.
The hides are then polished at 94 preferably on a felt roller to obtain smoothness by placing a piece of felt approximately one-third of an inch thick on a motor-driven roller. Both sides of the hide are polished to produce the finished product 96.
The finished hides 96 can be cared for as one would care for a woolen sweater. The hides can be washed in cold water by hand or in a cold water laundry machine cycle. It is best to dry the leather by allowing it to drip dry over a sweater screen, but one can use a low heat cycle dryer if desired. The leather can be washed in cold water and drip dried without spotting the leather, running the dye, or causing the leather to become cracked or brittle. Thus, it is not necessary to dry clean the finished product.
The finished hides can also be ironed and pressed on the flesh side with an iron at a wool temperature setting. The color can be further intensified by briskly pressing the iron without stopping on any point.
A wide range of colors can be applied to dyes using the process of this invention. The finished leather also has a high tear strength and is washable without running of the dye. These properties are believed due to the complete penetration of the dye through the leather which contrasts with many conventional processes where it is believed that the dye is only coated on the outside surface of the leather, similar to a paint spray process.
Collagen in rawhide is known to be ion-bearing and can act on bases and on acids. In this case, the dyeing system depends exclusively on the isoelectric state of the skin, that is according to the collagen's tendency to absorb and assimilate the ions in the dye. The isoelectric point is at 5.2 pH. At a lower pH, anions are bonded, and at a higher pH cations are bonded. Many wool detergents in commerce contain a percentage of soda or similar alkali. Before using the product, it is therefore advisable to test its akalinity with litmus paper. The blue will be more or less intense according to the percentage of soda contained in the wool detergent used.
A direct dye bath may, according to color and mixing method, be a real solution or a colloidal electrolite solution or a poly-dispersed solution, that is, one made up of aggregates of molecules of various sizes in a state of dynamic equilibrium. However, there are free molecules in the dye bath, in the majority of cases at the same time as aggregates of molecules which have been such during the solution process, or which have formed subsequently.
The free molecules are those which are more liable to penetrate into the fibers, because a fiber is not a homogeneous structure; but may be made up of areas arranged in a structure which may be compared to that of a crystal, and areas in which the molecules are less tightly arranged, or even in complete disorder, the latter being known as amorphous areas.
The amorphous areas are those which most affect the dyeing process. When the dye is in the form of single molecules, it can penetrate into the amorphous areas and spread, helped by thermal agitation, which implies not only the molecules making up the amorphous areas themselves, but also the dyeing molecules. Naturally, in order to penetrate, the molecules must be of such a size as to pass through these areas, otherwise the dye is superficial and is liable to rub off. Dye molecules are not all the same size or the same shape, and some therefore penetrate the amorphous areas more easily than others. Once they have entered the fibers, the dye molecules find a suitable environment and stabilize.
Direct dyes are sulphonic acid sodium salts, which dissociate when dissolved into a cation, the sodium, and an anion, the dye. When the fiber is wetted, it acquires a negative potential. There is, therefore, repulsion between the dyeing anion and the negatively charged fiber, which makes absorption of the dye more difficult. The addition of electrolytes reduces this negative potential. At the beginning of the dyeing process, there is an electric barrier between fiber and dye which is greater than the charge of the dyeing anion. Later, due to the presence of electrolytes, the electrical difficulty is overcome. The next stage is the different behavior patterns of various fibers according to their amorphous area content.
In order to ensure good progress on these fibers by the dyes, accurate temperature control is necessary. An increase in temperature accelerates dyeing, but generally decreases the amount of dye absorbed, so that temperature can have two different aspects which influence dyeing times. High temperature encourages color diffusion, i.e., evening of color at the same time reducing dyeing time. An increase of 50° F. may be taken on the average to double dyeing speed.
All direct dyes have their own point of equilibrium. Once the point is reached, dyeing is carried out by slowly cooling the dye bath, ensuring a deep and uniform dye.
The dyeing drum must act in such a way that the hides are lifted by special pins and then dropped so as to obtain maximum action of the dye on the hides. The drum must revolve at the correct speed for this to occur. If the speed is too high, the hides will be held against the walls by centrifugal force.
A 300 cm. diameter drum should not turn at more than about 14 or 15 revolutions per minute, equal to a peripheral speed of about 13,200 cm. per minute. The peripheral speed is the same for all sizes of drums and enables the number of revolutions for any given drum diameter to be calculated as follows:
Number of Revolutions=(Peripheral Speed/Circumference)
where Circumference=diameter×3.14.
The number of revolutions, however, is not an inflexible factor. The important point is that the hides should fall as far as the internal diameter of the drum allows. Brisk drumming greatly facilitates absorption of the dye, and it should be emphasized that a suitable diameter drum should be used. Thickness must always be smaller than diameter of the drum in order not to defeat its purpose. | A process is disclosed for preparing a suede leather product from animal hides. The hide is scalded before tanning and the finished product can be washed and ironed in a manner similar to a woolen garment. The hide is pretanned in formaldehyde, neutralized in sodium bicarbonate, tanned with a basic chrome solution, neutralized with sodium sulfate, and dyed with a direct color dye. More specifically, an outer suede product is obtained from the external corium of the skin, instead of the flesh side, with the result that less expensive sheepskin acceptable to the trade can be used in place of top grade kidskin and goatskin suedes. In a preferred practice of the method, the hide is burnt twice in scalding steps carried out in a swelling state, soon after first and second fleshing steps and, prior to a bating step. The burning affects the entire thickness of the fibrous grain layer by exposing the upper layer of the corium by soaking the hide in the third solution of sodium sulfide after a third fleshing step. The process obtains a soaped-water washable skin capable of maintaining a soft condition and avoiding fading of the dye. The washable condition is obtained by soaking the dyes, greased with egg yolk, in hot water. | 2 |
FIELD OF THE INVENTION
The present invention relates to mechanical tools and, more particularly, to wrenches and other devices designed to apply pressure to an object placed between two jaws of a tool.
BACKGROUND OF THE INVENTION
Wrenches and other hand tools often can not exert enough force to grip an object securely. In the case of wrenches, rusted, frozen and undersized nuts are often difficult to remove and become further deformed by the action of the wrench jaws. Wire cutters and other hand tools that apply an increasing force on an object between jaws of a hand tool often lack sufficient mechanical advantage to function with wire of more than a small gage.
Pliers, socket wrenches, open end wrenches, vise grips type devices and pipe wrenches are well known.
Wrenches which function as an approximation of the nut head, such as open end wrenches and socket wrenches, must by necessity be slightly oversized so that they can accommodate a rusted nut and so that they can be applied and removed easily. This mismatch between the nut head and the wrench face will tend to reduce mechanical efficiency and limit the gripping force exerted upon the faces of the nut. Likewise traditional wire cutters have a limited leverage and force which can be exerted on the wire or other material to be cut when inserted between jaws of the tool.
Vise grip tools enable an adjustable degree of leverage to increase pressure on the object grasped. Problems with the vise grip include high pressure on the handles in order to get a tight grip, a tendency to distort or destroy the surface of the object gripped, high pressure required to release the grip, and lack of any feedback or “mechanic's feel” when using the vise grip.
Traditional pliers are usually made to fit a large range of sizes of nut or object to be gripped. Conventional pliers are severely limited in the amount of mechanical advantage they provide and often strip nut heads because of the mechanical force fed back into the handles when the closed pliers is turned forces the handles open and releases the grip on the nut.
SUMMARY OF THE INVENTION
In accordance with the present invention, there is provided a tool comprising at least one movable arm with an integral or attached cam surface and a second opposing retaining surface to which the cam surface is moveably related such that closing the movable arm causes the cam surface to press against an object set between the cam surface and a retaining surface. The compression force is proportional to the degree of closure of the arm and the cam is angled relative to the retaining surface to apply force perpendicular to the retaining surface.
A feature of the preferred instantiation of the invention is to provide a compression hand tool which can be used to apply variable pressure to an object placed between a retaining surface and of an opposing cam surface.
It is another feature of the preferred instantiation of the invention to provide for regulation of the pressure applied by closing the arms of the tool.
It is another feature of the preferred instantiation of the invention to enable the turning force of the tool to be independent of the amount of compression exerted.
It is another feature of the preferred instantiation of the invention to align the cam surface relative to the retaining surface such that closing the lever arms results in a force vector at an angle to the center line so that the nut or other intervening object is driven into the pocket of the jaw. In the case of a nut, the resulting force tends to form the nut head into the vertex and side shapes of the jaw pocket.
It is another feature of the preferred instantiation of the invention to adjust for a range of sizes of intervening object by the design of the cam surface. In particular a slightly under or over sized nut can be accommodated at one setting of the levers and rounded or stripped nuts will be compressed to restore their original edges by compression of the cam surface against the pocket of the jaw.
It is another feature of the preferred instantiation of the invention to enable the cam arm to be adjustable so that the distance from the cam surface to the opposing surface may be increased or decreased.
In accordance with another feature of the preferred embodiments of the invention an adjustable cam wrench has handles, or lever arms. One lever arm has a retaining surface for a nut or bolt. The retaining surface contacts two or three faces of the nut, depending upon the size of the nut. The other lever arm has a cam surface. Both lever arms rotate about a fixed pivot. One lever arm, most preferably the lever arm with the cam surface is rotatably fixed to a bearing member and the bearing member is rigidly fixed to the fixed pivot. Most important, is that the fixed pivot is positioned off center, that is, non-concentric with respect to the bearing. Accordingly, the bearing and the fixed pivot have an offset center of rotation. A lever arm position adjuster fits over the bearing and locks to it, preferably with a transverse pin that enables the arm position adjuster to rotate in a plane parallel to the plane of the body of the wrench. Rotation of the adjuster arm varies the distance between the cam surface and the fixed pivot.
In accordance with another feature of the present invention one end of the arm position adjuster is fitted with one or more locking pins that fit into engagement holes formed in the lever arm having the cam surface. The arm position adjuster is pivotable about a transverse pin that locks the arm position adjuster to the bearing.
In accordance with another feature of the invention a wrench is provided which has a pair of lever arms that rotate about a fixed pivot. The position of one lever arm is variable relative to the fixed pivot. The lever arm whose position is variable relative to the fixed pivot is provided with a bearing member. The fixed pivot is mounted in the bearing non-concentric with the bearing whereby movement of the position adjuster from the position in which the wrench accommodates a large nut or bolt head to the position in which the wrench accommodates a small nut, increases the distance between the cam surface and the fixed pivot. The cam surface lever arm is in a rotational relationship with the bearing, and accordingly, has an eccentric relationship with fixed pivot. It should be noted that the term “cam surface” refers to a surface which bears against one face of a nut and forces the nut into engagement with a nut retaining region of the other lever arm. The cam or bearing surface of the lever arm forces the nut into the vertex formed by the intersection of the face of the nut retaining region of a lever arm essentially parallel to the cam surface and a second face of the nut retaining region. The nut retaining region has an open end and a closed end and the second face is at the closed end. Thus, a nut is always forced against two nut retaining faces, irrespective of the size of the nut.
In accordance with another feature of the invention a wrench is provided with a tapered relief angle of the distal ends of the lever arms such that nuts attached to a flat surface may be approached by holding the cam compression tool at an angle to the work surface.
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 front view of an adjustable cam compression wrench adjusted to the smallest opening position in accordance with the disclosure;
FIG. 2 is a front view of an adjustable cam wrench with arm position adjuster at a middle opening position in accordance with the disclosure;
FIG. 3 is a front view of an adjustable cam wrench with arm position adjuster at the fully opened position in accordance with the disclosure;
FIG. 4 is a front view of an assembled wrench with arm position adjuster opened to maximum position fully opened in accordance with the disclosure;
FIG. 5 is a front view of a non-adjustable alternate embodiment of a fixed pivot cam wrench in accordance with the disclosure;
FIG. 6 is a side view of the fixed pivot wrench of FIG. 5 in accordance with the disclosure;
FIG. 7 is front view of the cam wrench with a side and top view of the arm position adjuster in accordance with the disclosure;
FIG. 8 is a front view of an adjustable cam wrench having an alternative orientation of the retaining surface and cam surface and showing details of the arm position adjuster in accordance with the disclosure;
FIG. 9 is a front view of an adjustable cam compression tool with the arm position adjuster removed in a fully open position, showing the preferred orientation of the cam surface to the nut and the retaining surface in accordance with the disclosure;
FIG. 10 is a rear exploded view of an adjustable cam wrench in accordance with the disclosure;
FIG. 11 is a perspective view of the lever arm pivot and relief angle of the head in accordance with the disclosure;
FIG. 12 is a perspective view of an adjuster bearing of an adjustable cam wrench in accordance with the disclosure;
FIG. 13 is a front view of a lever arm showing engagement holes and cam surface in accordance with the disclosure;
FIG. 14 is a perspective front view of a lever arm of an adjustable cam wrench with fixed pivot in accordance with the disclosure;
FIG. 15 is a left plan view of an arm position adjuster with pins and spring in accordance with the disclosure;
FIG. 16 is a perspective view of a arm position adjuster of an adjustable cam wrench showing pins, transverse hole and spring in accordance with the disclosure;
FIG. 17 is a perspective view of an adjustable cam wrench partially disassembled in accordance with the disclosure;
FIG. 18 is an exploded left perspective view of a cam wrench showing arm position adjuster and lever arms in accordance with the disclosure; and,
FIG. 19 is an alternate embodiment of the wrench having the retaining surface of the fixed jaw at a 90 degree angle to the centerline of the tool. The cam lever arm is shown in its maximum and minimum travel positions corresponding to the largest and smallest size nut which the embodiment will accept.
For purposes of clarity and brevity, like elements and components will bear the same designations and numbering throughout the Figures.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
It should be noted that the discussion of the theory of operation as presently understood is by way of providing a better understanding and does not limit the scope of the invention.
FIG. 1 is a front view of an adjustable cam wrench with handles, or lever arms, 12 and 14 at their minimum distance from each other. The Figure shows the first lever arm 12 and second lever arm 14 that are configured as well known in the art for user comfort. The retaining surface 32 of the fixed jaw and cam surface 42 extend from lever arm 12 and lever arm 14 respectively and are connected at a fixed pivot 20 with an associated adjuster bearing 30 . The bearing 30 and fixed pivot 20 have an offset center of rotation. The arm position adjuster 26 fits over the bearing 30 and locks to it with a transverse pin (not shown) that enables the arm position adjuster 26 to rotate horizontally relative to the body of the wrench. That is, it rotates in a plane essentially parallel to the plane of the body of the wrench. One end of the arm position adjuster 26 is fitted with one or more locking pins 38 ( FIG. 15 ) that fit into engagement holes 36 formed in lever arm 12 .
Arrow 18 represents the contact region between the cam surface 42 and the nut. The cam surface contact region is on the region of the face of the nut away from the closed region 32 A of the retaining surface 32 of the fixed jaw 21 A of the lever arm 12 . It should be noted that the term “fixed” is used to indicate that it rotates about a fixed pivot 20 , whereas the cam surface 42 path of movement is dependent upon the position of the position adjuster 26 , and thus is not fixed.
While both arms rotate about the fixed pivot 20 the position of lever arm 14 and its cam surface 42 are is variable relative to the fixed pivot 20 . Since the pivot 20 is not concentric with the bearing 30 movement of the position adjuster from the position in which the wrench accommodates a large nut or bolt head to the position in which it accommodates a small nut, increases the distance between the cam surface and the fixed pivot 20 . The terms nut and bolt are used herein interchangeably, and most typical are hexagonal. The term “hex head” is commonly employed to indicate such elements. As evident from FIG. 10 , the bearing 30 is received in hole 30 A. Accordingly, lever arm is in a rotational relationship with bearing 30 , and accordingly, a eccentric relationship with fixed pivot 20 , since pivot 20 is not concentrically positioned with respect to bearing 30 .
The arm position adjuster 26 is utilized by pressing down on the end opposite the locking pins 38 and rotating the arm position adjuster 26 to a point such that the locking pins 38 engage with one or more engagement holes 36 . Rotation of the arm position adjuster 26 serves to reposition lever arm 14 relative to the fixed pivot 20 . In the preferred instantiation the rotation of the bearing adjuster 26 results in the cam surface 42 moving relative to the retaining surface 32 such that the point of contact of the cam surface 42 is maintained in the same relative position for a variety of sizes of hexagonal nuts. The point of contact and the orientation of the retaining surface 32 to the nut is such that closing the handles of the wrench drives the nut into the retaining surface 32 . In order to provide a better grip, the cam surface 42 has a slight convexity on the order of about five (5) degrees, as indicated in FIG. 8 . An opening spring 34 is preferably fitted to aid in “ratcheting” the wrench so that it tends to open when the handles are released to enable a partial rotation of the wrench relative to the nut head without removing the tool from the nut.
It should be noted that any other method known in the art can be used to adjust the position of the cam surface and that the arm position adjuster illustrated herein is for example. The critical feature is the ability to adjust and retain the cam surface, through adjustment of the bearing, in one or more positions relative to the retaining surface.
The caming action, in addition to the slight convexity, serves to enable a user to apply a greater amount of pressure than can be attained using a flat contact surface.
FIG. 2 is a front view of the wrench of FIG. 1 but with the arm position adjuster 26 selecting a medium setting.
FIG. 3 is a front view of the wrench of FIG. 1 with the arm position adjuster 26 selecting the largest setting, enabling the maximum distance between the cam surface 42 and the retaining surface 32 . In FIG. 4 the lever arms 12 and 14 have been opened to their maximum separation enabled by the arm position adjuster 26 setting of FIG. 3 .
FIG. 5 is a non-adjustable variant of the cam compression tool. The cam surface 142 has, in the preferred embodiment, the convexity of about less than five (5) degrees. The lever arms 112 and 114 are, as with other embodiments disclosed herein, configured for user comfort and can be covered with a not-slip material if so desired. In this embodiment the spring 134 forces the lever arms to separate when in a “resting” position. The lever arms 112 and 114 rotate around the fixed pivot 120 .
FIG. 6 is a side view of the wrench of FIG. 5 showing a relief angle 128 of the head enabling the wrench to be held at an angle to the work surface.
FIG. 7 illustrates the adjustable wrench showing the change in cam surface 42 position through rotation of the arm position adjuster 26 .
FIG. 8 is a front view of an alternate adjustable wrench having an alternative orientation of the retaining surface 232 and cam surface 242 . In this version the point of contact of the cam surface 242 and drive the nut into the retaining surface 232 from the vertex of the nut rather than the flat surface.
FIG. 9 is a top view of a partially disassembled cam compression wrench with the arm position adjuster 26 removed to display the engagement holes 36 more fully. The placement of the pivot 20 and bearing 30 in relationship to the engagement holes 36 and also be seen in greater detail.
FIG. 10 illustrates the wrench of FIG. 1 disassembled showing all the elements, including optional spacing washers 50
FIG. 11 is a perspective view of lever arm 12 showing the pivot 20 and a relief angle 28 on the head.
FIG. 12 is a perspective view of the adjuster bearing 30 showing the transverse pin 40 used to maintain the bearing 30 on the pivot 20 .
FIG. 13 is the lever arm 14 of the cam wrench shown in FIG. 1 showing the cam surface 42 and retaining holes 36 .
FIG. 14 is the lever arm 12 of the cam wrench shown in FIG. 1 showing the pivot 20 and retaining surface 32 .
FIG. 15 is a side view of the arm position adjuster 26 showing the retaining pins 38 and receiving holes 41 for the transverse pin 40 . The return spring 44 keeps the arm position adjuster 26 parallel to the surface of the wrench.
FIG. 16 is a perspective view of the arm position adjuster 26 showing the receiving holes 41 for the transverse pin 40 and the locking pins 38 .
FIG. 17 is a perspective view of a partially disassembled led cam wrench of FIG. 1 showing the placement of the transverse pin 40 which serves as a pivot bearing for the adjuster 26 and for locking the adjuster to the bearing 30 .
FIG. 18 is a side view of the cam wrench of FIG. 1 showing the pivot 20 with a groove 22 to accept the transverse pin 40 . Also shown, is the bearing 30 , mounted in the lever arm 14 .
FIG. 19 is a front view of an alternative cam compression tool with the retaining surface of lever arm 314 oriented with the flat retaining surface 332 at a 90 degree angle to the center line 350 of the tool and the lever arm 312 oriented to maintain the cam surface 342 moving through a parallel orientation to said flat retaining surface 332 .
In the figure the lever arm 314 and cam surface 342 are positioned for the largest size nut 370 at the maximum travel position and at the positioning 314 A corresponding to the smallest nut 372 . It should be noted that the separation distance illustrated herein is for example is does not necessarily reflect any proportions or ratios.
It is thus seen that the arm position adjuster mechanism produces a tool that is the equivalent of a tool having a plurality of wrench arms each having a different orientation relative to the fixed pivot.
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.
Broad Scope of the Invention
While illustrative embodiments of the invention have been described herein, the present invention is not limited to the various preferred embodiments described herein, but includes any and all embodiments having equivalent elements, modifications, omissions, combinations (e.g., of aspects across various embodiments), adaptations and/or alterations as would be appreciated by those in the art based on the present disclosure. The limitations in the claims (e.g., including that to be later added) are to be interpreted broadly based on the language employed in the claims and not limited to examples described in the present specification or during the prosecution of the application, which examples are to be construed as non-exclusive. For example, in the present disclosure, the term “preferably” is non-exclusive and means “preferably, but not limited to.” In this disclosure and during the prosecution of this application, means-plus-function or step-plus-function limitations will only be employed where for a specific claim limitation all of the following conditions are present in that limitation: a) “means for” or “step for” is expressly recited; b) a corresponding function is expressly recited; and c) structure, material or acts that support that structure are not recited. In this disclosure and during the prosecution of this application, the terminology “present invention” or “invention” may be used as a reference to one or more aspect within the present disclosure. The language of the present invention or inventions should not be improperly interpreted as an identification of criticality, should not be improperly interpreted as applying across all aspects or embodiments (i.e., it should be understood that the present invention has a number of aspects and embodiments), and should not be improperly interpreted as limiting the scope of the application or claims. In this disclosure and during the prosecution of this application, the terminology “embodiment” can be used to describe any aspect, feature, process or step, any combination thereof, and/or any portion thereof, etc. In some examples, various embodiments may include overlapping features. In this disclosure, the following abbreviated terminology may be employed: “e.g.” which means “for example.” | A variable compression tool comprising a retaining surface attached to a lever arm and a cam surface attached to a second lever arm. The two arms are moveably connected through a fixed pivot point. The profile of the jaw pocket may be of various shapes. In one instantiation, the jaw pocket conforms to at least two sides of a nut. The orientation of the cam surface to the jaw pocket is such that the force generated by closing the jaws forces the nut into the retaining surface. Adjustment of the cam lever arm is regulated by an eccentric cam adjuster bearing which changes the effective center of rotation of lever arm two in two dimensions simultaneously by rotation of the bearing. | 1 |
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of application Ser. No. 924,402, filed Oct. 29, 1986 and now U.S. Pat. No. 4,762,588.
BACKGROUND OF THE INVENTION
This invention relates to a method of manufacturing calcium carbonate single crystal (calcite) widely used as an optical polarizer, etc.
Single crystals of calcium carbonate (CaCO 3 ) are suitable for optical uses and, for this purpose, natural calcite crystals are currently used. Calcite single crystals exhibit double refraction of incident light. Calcite has a high refractive index and is used as a polarizing prism in optical apparatus. Because of recent advances in the design of optical apparatus, such as laser optics and an optical communication apparatus, there is an increased demand for a material with excellent optical characteristics. In this regard, calcite single crystal is an ideal material, and is expected to be more and more in demand.
Calcite single crystal has been obtained only from natural sources because it is not yet being industrially synthesized. For commercial use, natural calcite must be colorless and transparent, must have no bubbles or cracks and no twining and no internal strains, and must be greater than a certain size. However, calcite single crystal that will meet these requirements is found only in limited quantities in the Republic of South Africa, Mexico, etc., and reserves are running low.
There have been experiments to synthesize calcium carbonate single crystal. One method is crystallization from a solvent, another is the synthesizing from a gel, a third is crystallization from a flux or melt, a fourth is hydrothermal synthesis, and recently an FZ method under high pressure have been suggested. However, optical characteristics such as transparency of the resultant crystals have not been entirely satisfactory due to defects such as impurities, mixing, dislocations, inclusions, or internal strains.
Among the methods tried for the manufacture of calcium carbonate single crystal, hydrothermal synthesis is most similar to the process by which natural calcite is grown as a hydrothermal ore deposit. Therefore, hydrothermal synthesis can produce a desired calcium carbonate single crystal with characteristics similar to natural calcite.
The hydrothermal synthesis process for manufacturing calcium carbonate single crystal utilizes an aqueous solvent hold at a predetermined temperature and pressure in an autoclave. Alkaline aqueous solutions such as sodium hydroxide (NaOH) or alkali carbonate aqueous solutions such as sodium carbonate (Na 2 CO 3 ), potassium carbonate (K 2 CO 3 ), etc. are generally used as the aqueous solvent. This method for growth of calcium carbonate single crystal is essentially a modification of conventional growth technology for artificial crystals. Under the following conditions:
Solvent-6 mol K 2 CO 3 aqueous solution
Temperature-410° to 445° C.
Pressure-1720 atmospheres
Growth speed-50 μm/day
about 3 mm growth layer of a calcium carbonate single crystal has been obtained.
The above described hydrothermal synthesis is disclosed in D. R. Kinlock H, R. F. Belt, R. C. Puttbac H, Journal of Crystal Growth 24/25 (1974) 610-613.
A method of manufacturing calcium carbonate single crystal grown by hydrothermal synthesis using a chloride aqueous solution is described and claimed in the commonly assigned U.S. Pat. No. 4,685,995, of Shinichi Hirano and Seiko Instruments & Electronics Ltd., issued Aug. 11, 1987.
In crystal growth method of calcium carbonate utilizing the conventional alkali carbonate aqueous solution, crystal can be grown, but there are problems to be solved as follows:
Firstly, due to the high concentration of solvent, inclusions frequently occur in the resultant crystals. These inclusions will result in inferior optical characteristics. Next, due to a high concentration of solvent, it is impossible to achieve sufficient pressure for quantitative production. In other words, the higher the solvent concentration, the lower the obtained pressure becomes even with the same filling-up rate. In the case of a 6 mol concentration of K 2 CO 3 aqueous solution at 445° C. and a filling-up rate of nearly 100%, it is impossible to obtain a pressure of 1720 atmospheres. Due to this, it is necessary to apply additional pressure from outside the autoclave thereby causing the apparatus and pressure system etc. to be too complicated. Using an alkali carbonate aqueous solution, the growth speed will be very slow, i.e., 50 μm/day, and therefore it will take more or less a year to grow crystals large enough to be used as optical elements.
It is an object of the present invention to provide a simple method to grow relatively quickly excellent calcium carbonate single crystal with good optical characteristics.
According to the present invention, there is provided a method for manufacturing a calcium carbonate single crystal by hydrothermal synthesis at a given temperature and pressure within a nitrate aqueous solution as a solvent.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view of a test tube used in Example 1 according to the present invention; and
FIG. 2 is a sectional view of a pressure vessel used in Example 2 according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The problems encountered in growing calcium carbonate single crystal by the prior art hydrothermal synthesis, namely, inferior optical quality, complicated apparatus, and long growth period, etc. result from having to use a high concentration solvent and high pressure. In other words, the problems stem from the choice of solvent and growth conditions.
A nitrate aqueous solution is now found best to avoid these problems, among various kinds of existing solvent such as alkaline, carbonate acid and chloride solutions.
In the present invention, hydrothermal synthesis initiating material is dissolved in a suitable aqueous solution of solvent at an appropriate temperature and pressure, and crystallization on a substrate is effected by gradual cooling or by transporting nourishment (material) through a temperature differential. The solvent should, therefore, be such that the starting material dissolves well in it and it should have little corrosive action on the apparatus used. A nitrate aqueous solution as a solvent is found to be ideal.
The invention is further described with reference to the following Examples.
EXAMPLE 1
As starting material, commercially available calcium carbonate of high purity was used. For hydrothermal synthesis an autoclaval test tube of stellite quality No. 25 was used. FIG. 1 shows the structure of the test tube having a pressure vessel body 1 shows the structure of the test tube having a pressure vessel body 1 with a cover 3 and a seal 2.
The inside temperature of the pressure vessel body was measured through a temperature measuring hole 4. A gold capsule, 33 mm-5 mm in diameter, was placed in the test tube. The starting material and solvent were poured into the test tube for hydrothermal synthesis. In this case, the pressure between the inside and the outside of the capsule was balanced by filling the inside of the pressure vessel with distilled water.
By using various solvents, the result of growing crystal for each solvent and the hydrothermal treatment conditions are shown in the following table I:
TABLE I______________________________________Hydrothermal synthesis conditions Size* of temperature pressure crystalsolvent [°C] [kg/cm.sup.2 ] obtained______________________________________3 Mol 300 750 0.2-0.3 mmNaNO.sub.33 Mol 300 750 0.2-0.3 mmNaNO.sub.33 Mol 370 750 0.3-0.5 mmNaNO.sub.33 Mol 420 500 0.1-0.2 mmNaNO.sub.33 Mol 450 750 0.8-1.0 mmNaNO.sub.33 Mol 500 750 1.0-1.2 mmNaNO.sub.33 Mol 400 750 0.5-0.6 mmKNO.sub.33 Mol 400 1000 0.6-0.8 mmKNO.sub.33 Mol 380 750 0.3-0.5 mmLiNO.sub.33 Mol 420 750 0.6-1.0 mmLiNO.sub.33.5 Mol 180 1000 not grownCa(NO.sub.3).sub.23.5 Mol 200 750 0.1-0.2 mmCa(NO.sub.3).sub.24.0 Mol 240 750 0.3-0.4 mmCa(NO.sub.3).sub.23.5 Mol 280 1000 0.3-0.5 mmCa(NO.sub.3).sub.23.0 Mol 320 800 0.4-0.5 mmCa(NO.sub.3).sub.23.5 Mol 360 750 0.6-0.7 mmCa(NO.sub.3).sub.23.5 Mol 400 1000 0.8-1.0 mmCa(NO.sub.3).sub.23.0 Mol 440 750 0.8-1.2 mmCa(NO.sub.3).sub.21.0 Mol 100 1000 not grownNH.sub.4 NO.sub.31.0 Mol 120 1000 0.2 mmNH.sub.4 NO.sub.31.0 Mol 140 1000 0.4-0.6 mmNH.sub.4 NO.sub.30.8 Mol 170 1000 0.6-1.0 mmNH.sub.4 NO.sub.30.8 Mol 200 1000 0.8-1.2 mmNH.sub.4 NO.sub.30.5 Mol 240 750 0.8-1.1 mmNH.sub.4 NO.sub.30.5 Mol 280 750 0.9-1.2 mmNH.sub.4 NO.sub.30.5 Mol 320 1000 1.0-1.4 mmNH.sub.4 NO.sub.30.5 Mol 360 750 1.2-1.5 mmNH.sub.4 NO.sub.30.5 Mol 100 1000 0.2 mmNH.sub.4 NO.sub.30.5 Mol 120 1000 0.3 mmNH.sub.4 NO.sub.30.1 Mol 150 1000 0.3 mmNH.sub.4 NO.sub.30.02 Mol 170 1000 0.2 mmNH.sub.4 NO.sub.30.01 Mol 200 1000 0.2 mmNH.sub.4 NO.sub.30.01 Mol 240 800 0.3 mmNH.sub.4 NO.sub.30.01 Mol 280 500 0.4 mmNH.sub.4 NO.sub.30.01 Mol 360 500 0.4-0.6 mmNH.sub.4 NO.sub.30.02 Mol 320 500 0.4-0.7 mmNH.sub.4 NO.sub.33.0 Mol 100 300 0.2 mmNH.sub.4 NO.sub.33.0 Mol 120 300 0.4 mmNH.sub.4 NO.sub.33.0 Mol 140 200 0.3-0.5 mmNH.sub.4 NO.sub.33.0 Mol 170 100 0.3-0.6 mmNH.sub.4 NO.sub.33.0 Mol 200 100 0.3-0.6 mmNH.sub.4 NO.sub.33.0 Mol 240 50 0.4-0.6 mmNH.sub.4 NO.sub.33.0 Mol 280 50 0.5-0.7 mmNH.sub.4 NO.sub.33.0 Mol 320 20 0.5-0.7 mmNH.sub.4 NO.sub.33.0 Mol 360 20 0.7-0.9 mmNH.sub.4 NO.sub.3______________________________________ *All growth periods were 7 days.
As shown in the above table I, it was found that crystals were grown by using any one of NaNO 3 , KNO 3 , LiNO 3 , Ca(NO 3 ) 2 and NH 4 NO 3 as the solvent. In the case of using the alkali nitrate aqueous solutions, namely NaNO 3 , KNO 3 and LiNO 3 , it is possible to grow crystal in the range of 300° to 500° C., and the preferable temperature range of the hydrothermal synthesis is in the range of 370° to 420° C. As for pressure, unlike the case of using an alkali carbonate aqueous solution, it is possible to grow crystals at a pressure lower than 1000 kg/cm 2 , and a very good crystal growth at pressures of around 750 kg/cm 2 is achieved. By making the concentration of each alkali nitrate aqueous solution large, good crystal can be grown, however it is preferable to arrange the molar concentration to about 3 Mol in view of the relation with pressure because it is easier in handling. In the case of using Ca(NO 3 ) 2 aqueous solution, the preferable temperature range of the hydrothermal synthesis is in the range of 200° C. to 400° C. If the temperature is over 400° C., it is still possible to grow crystals, however, there is the possibility of reduced quality. In the case of NH 4 NO 3 aqueous solution, the preferable temperature range of the hydrothermal synthesis is in the range of 100° to 360° C. If the temperature is over 360° C., it is possible to grow crystals, however, there is the possibility of reduced quality and corrosion of the pressure vessel. As for pressure, it is possible to grow crystals at pressure lower than 300 kg/cm 2 by selecting other hydrothermal synthesis conditions, e.g., the concentrations of the solvent or growth temperature. The NH 4 NO 3 aqueous solution comprises preferably 0.01 to 3 Mol aqueous solution of NH 4 NO 3 . It was identified by X-ray diffraction that in each case, the crystals grown were calcium carbonate single crystal.
EXAMPLE 2
FIG. 2 is a sectional view illustrating a typical test tube used in this Example. The test tube was made of stellite 25 as in Example 1, however the inside was lined with platinum in order to avoid contamination by pollutants. A pressure vessel body 5 was sealed with a cover 7 through a sealing ring 6. At the bottom of the pressure vessel body 5, starting material 8 for the crystals to be grown was placed. The starting material was refined and recrystallized in nitrate solvent according to the method of Example 1 and was powdered. A crystal support frame 9 carried thereon a species or seed crystal 10 over the starting material 8 at an upper portion of the pressure vessel. The seed crystal 10 was a calcite with (0001) faces of natural optical grade. As the seed crystal, calcite with (1011) faces of natural optical grade may be used. It was necessary to choose a seed crystal with few internal inclusions, and little lattice displacement, etc. so that defects in the single crystal to be grown thereon may be avoided. A baffle 11 was provided between the starting material 8 and the seed crystal 10 to produce a temperature difference therebetween and was supported on the frame 9. The inside of the pressure vessel body 5 was filled up with nitrite aqueous solution, e.g., NaNO 3 , KNO 3 , LiNO 3 , Ca(NO 3 ) 2 and NH 4 NO 3 , as a solvent at such a filling-up rate as to establish a predetermined temperature and pressure.
By using various solvents, the result of growing crystal for each solvent and the hydrothermal treatment are shown in the following table II:
TABLE II__________________________________________________________________________ Thickness Temperature Temperature of grown of seed of starting Growth layer GrowthSolvent crystal material Pressure period or film rate__________________________________________________________________________3 Mol .sup. 370°C. .sup. 420°C. 750 50 6.6 132NaNO.sub.3 kg/cm.sup.2 day mm μm/day3.5 Mol 360 400 750 50 7.0 140Ca(NO.sub.3).sub.23.5 Mol 280 320 750 50 3.8 76Ca(NO.sub.3).sub.23.5 Mol 200 260 750 50 2.2 44Ca(NO.sub.3).sub.20.5 Mol 280 320 750 50 10 200NH.sub.4 NO .sub.30.5 Mol 220 260 750 50 8.9 178NH.sub.4 NO.sub.30.8 Mol 160 200 1000 50 8.6 172NH.sub.4 NO.sub.33 Mol 280 320 20 50 7.3 146NH.sub.4 NO.sub.33 Mol 220 260 50 50 7.6 152NH.sub.4 NO.sub.33 Mol 160 200 100 50 7.0 140NH.sub.4 NO.sub.30.01 Mol 280 320 500 50 6.5 130NH.sub.4 NO.sub.30.01 Mol 220 260 800 50 5.5 110NH.sub.4 NO.sub.30.02 Mol 160 200 1000 50 4.0 80NH.sub.4 NO.sub.3__________________________________________________________________________
The characteristics of the grown layer or film in each case were those of calcium carbonate single crystal and were identified by X-ray diffraction. Its optical characteristics were the same as those of natural calcite (with respect to permeability rate, compound refractive index, etc.).
Having described a specific embodiment of our invention, it is believed obvious that modification and variation of our invention is possible in light of the above teachings.
From the above discussion, it will be appreciated that it is easier for growth of calcium carbonate single crystals to be industrialized by hydrothermal synthesis because a pressure less than 1000 kg/cm 2 is used and, at the same time, defects inside the grown crystals are reduced as, compared with the prior art growth methods of calcium carbonate single crystal using alkali carbonate aqueous solutions.
The growth rate of the crystals is over twice that achieved by the prior art method and this is a very favorable feature in view of industrialization. In the case of using NH 4 NO 3 aqueous solution, CaCO 3 single crystal is easily industrialized because of growth by lower pressure and lower temperature, e.g., lower than 300 kg/cm 2 pressure and temperature in the range of 100° to 360° C. It is thus possible for calcium carbonate single crystals of optical grade quality equal to that of natural calcite to be made industrially by the same technology as that for the current artificial crystals. To be industrially able to produce such crystals equal in quality to natural optical grade calcite will mean that it will be possible always to provide a market with such crystals with the same quality. Because of the dependence upon natural calcite, there has been no guarantee of either a regular supply or consistent quality. Industrialization of calcium carbonate single crystal will achieve such consistency and enhance their use in optical elements and parts, etc. used in a whole range of apparatus and will enable their characteristics to be improved. | A starting material composed of calcium carbonate is dissolved in a nitrate aqueous solution containing either Ca(NO 3 ) 2 or NH 4 NO 3 under application of heat and pressure. The starting material is hydrothermally synthesized within the nitrate aqueous solution to effect the rapid growth of calcium carbonate single crystal. | 2 |
The present invention relates to sulphonic fluorinated ionomers suitable for the preparation of membranes working from room temperature to high temperatures, of the order of 120° C.-180° C., in electrolytic applications, for example in fuel cells.
Specifically, the invention relates to sulphonic fluorinated ionomers crosslinked without involving the —SO 2 F groups and capable to maintain a high degree of hydration, both at room and at high temperature (up to 120°-180° C.), without substantially compromising the physical integrity of the membrane.
More specifically, in the case of crosslinked sulphonic fluorinated ionomers and having a low equivalent weight, lower than about 750, the obtained membranes show a high capability of water absorption, both at room and at high temperature (up to 120°-180° C.), without substantially compromising the physical integrity of the membrane.
In the case of sulphonic fluorinated ionomers having an equivalent weight higher than about 750 and up to about 1,300, by the crosslinking of the invention it is possible to prepare membranes having an extremely thin thickness, for example in the range 10-80 μm, which maintain a good hydration also at high temperatures, of the order of 120° C.-180° C., still maintaining the physical integrity.
BACKGROUND OF THE INVENTION
It is known in the prior art the use of the class of polymers called by the term “ionomers” in electrochemical applications, such as for example in fuel cells, chloro-alkali cells, lithium batteries, electrodialysis and in reactors in which the ionomer acts as a solid catalyst. These applications imply the contact of the ionomer with an aqueous or polar liquid having affinity with the ionic functional groups of the ionomer.
Generally, the larger the amount of sulphonic groups (ionomers having a low equivalent weight), the better the efficiency of the ionomer in the application, both in terms of ion exchange capability in electrochemical applications, and in terms of the catalyst activity in catalysis applications. From this point of view, an important parameter is the equivalent weight of the ionomer. The lower the equivalent weight, the higher the percentage of ionic groups. Therefore, ionomers having a low equivalent weight are desirable since they give a higher efficiency in the application.
In electrochemical applications, for example in fuel cells, there is a direct correlation between the ionomer conductivity and the retention of water of the ionomer. The ionic conductivity of the polymer, besides being increased by the higher presence of ionic groups in the polymer, results increased, within certain limits, also by the larger amount of water that the polymer is capable to keep (swelling degree). However, the excessive affinity of the ionomer with water has the drawback of an excessive swelling of the ionomer, which takes a gelatinous state thus losing its physical integrity. The ionomer therefore becomes completely unusable in all the applications wherein it is required under a solid form.
Also in the applications wherein the ionomer is mixed with or deposited on a support material, suitable to guarantee the form and the physical integrity of the final membrane, the ionomer must however show a sufficient physical consistency to prevent the release from the support and it must be quite insoluble in water with which it comes into contact during the use. Besides, the ionomer/membrane must be activated before the use, wherefore the chemical transformation of the precursor groups —SO 2 F into the corresponding ionic groups —SO 3 H is necessary. The membrane activation is carried out first by contacting it with an alkaline aqueous solution and then with an acid solution. During this transformation phase, if the ionomer has a high swelling degree, it can partially or completely dissolve in the reaction medium. At this point, it is extremely difficult to recover the ionomer and separate it from the by-products of the transformation reaction.
In the prior art, to obtain a limited hydration of the ionomer and sufficient physical integrity, polymers having a high equivalent weight, of the order of 1,000-1,200, i.e. having a low concentration of sulphonic groups, are used. Ionomers having a high equivalent weight absorb a limited amount of water, which guarantees the polymer insolubility. On the other hand, having few ionic groups, they have the drawback to give membranes with a low ionic conductivity during the application. An example of said membranes is represented by the commercial product NAFION®, used in fuel cells. These membranes to have a good physical integrity must however have a high thickness, generally higher than 100 μm. Besides, if these membranes are used at temperatures higher than 100° C., the water contained in the membrane, due to the limited number of hydrophilic groups —SO 3 H and the high thickness, tends to diminish, wherefore the membrane tends to dehydrate and the membrane conductivity is drastically reduced. Consequently, the NAFION® membranes are not effectively usable at temperatures higher than 100° C.
U.S. Pat. No. 4,940,525 describes sulphonic ionomers having a low equivalent weight, lower than 725, used to obtain unsupported thick membranes for fuel cells, only if the hydration product of the polymer is lower than 22,000. According to this patent so low hydration values are indeed necessary to maintain the polymer physical integrity at equivalent weights lower than 725, provided that the equivalent weight is not lower than 500 (col. 6, 8-16). In this patent no mention is made either to the behaviour of these membranes at high temperatures, up to about 120° C.-180° C., or to the minimum usable thickness maintaining the physical integrity.
The need was therefore felt to have available sulphonic fluorinated ionomers able to give membranes usable both at room and at high temperature (up to 120°-180° C.), without substantially compromising the physical integrity of the ionomeric membrane for sulphonic fluorinated ionomers having a low equivalent weight, lower than 750; in the case of sulphonic fluorinated ionomers having an equivalent weight higher than about 750 and up to about 1,300, to have membranes having an extremely thin thickness, for example in the range 10-80 μm.
The Applicant has surprisingly and unxpectedly found sulphonic fluorinated ionomers able to solve the above mentioned technical problem.
SUMMARY OF THE INVENTION
An object of the present invention are crosslinked sulphonic fluorinated ionomers, where crosslinking does not involve the —SO 2 F groups, having an equivalent weight 380-1,300 g/eq, and comprising:
(A) monomeric units deriving from one or more fluorinated monomers containing at least one ethylene unsaturation;
(B) fluorinated monomeric units containing sulphonyl groups —SO 2 F in an amount such as to give the above equivalent weight.
The fluorinated monomers of type (A) are selected from:
vinylidene fluoride (VDF);
C 2 -C 8 perfluoroolefins, preferably tetrafluoroethylene (TFE);
C 2 -C 8 chloro- and/or bromo- and/or iodo-fluoroolefins, such as chlorotrifluoroethylene (CTFE) and bromotrifluoroethylene;
CF 2 ═CFOR f (per)fluoroalkylvinylethers (PAVE), wherein R f is a C 1 -C 6 (per)fluoroalkyl, for example trifluoromethyl, bromodifluoromethyl, pentafluoropropyl;
CF 2 ═CFOX perfluoro-oxyalkylvinylethers, wherein X is a C 1 -C 12 perfluoro-oxyalkyl having one or more ether groups, for example perfluoro-2-propoxy-propyl.
The fluorinated monomers of type (B) are selected from one or more of the following:
F 2 C═CF—O—CF 2 —CF 2 —SO 2 F;
F 2 C═CF—O—[CF 2 —CXF—O] n —CF 2 —CF 2 —SO 2 F
wherein X═Cl,F or CF 3 ; n=1-10
F 2 C═CF—O—CF 2 —CF 2 —CF 2 —SO 2 F
F 2 C═CF—Ar—SO 2 F wherein Ar is an aryl ring.
Optionally the sulphonic fluorinated ionomers of the invention can contain from 0.01 to 5% by moles of monomeric units deriving from a bis-olefin of formula:
R 1 R 2 C═CH—(CF 2 ) m —CH═CR 5 R 6 (I)
wherein:
m=2-10, preferably 4-8;
R 1 , R 2 , R 5 , R 6 , equal to or different from each other, are H or C 1 -C 5 alkyl groups.
The introduction as comonomer of the bis-olefin of formula (I), having a number of unsaturations higher than the unit, is advantageous since said comonomer has the function to pre-crosslink the ionomer in the polymerization step. The introduction of the bis-olefin has the advantage to increase the length of the primary chains which will form the final network.
Preferably the sulphonic fluorinated ionomers of the present invention are crosslinked by peroxidic route, wherefore they must contain radical attack sites in the chain and/or in the terminal position of the macromolecules, for example iodine and/or bromine atoms.
Preferably the crosslinked fluorinated sulphonic ionomers of the invention comprise:
monomeric units deriving from TFE;
monomeric units deriving from CF 2 ═CF—O—CF 2 CF 2 SO 2 F;
monomeric units deriving from the bis-olefin of formula (I).
iodine atoms in terminal position.
As regards the introduction in the chain of said iodine and/or bromine atoms, it can be carried out by addition, in the reaction mixture, of brominated and/or iodinated “cure-sites” comonomers, such as-bromo and/or iodo olefins having from 2 to 10 carbon atoms (as described for example in U.S. Pat. No. 4,035,565 and U.S. Pat. No. 4,694,045), or iodo and/or bromo fluoroalkylvinylethers (as described in U.S. Pat. No. 4,745,165, U.S. Pat. No. 4,564,662 and EP 199,138), in such amounts whereby the content of “cure-sites” comonomers in the final product is generally in the range 0.05-2 moles for 100 moles of the other base monomeric units.
Alternatively or also in combination with the “cure-site” comonomers, it is possible to introduce in the end groups iodine and/or bromine atoms by addition to the reaction mixture of iodinated and/or brominated chain transfer agents, such as for example the compounds of formula R f (I) x (Br) y , wherein R f is a (per)fluoroalkyl or a (per)fluorochloroalkyl having from 1 to 8 carbon atoms, while x and y are integers in the range 0-2, with 1≦x+y≦2 (see for example U.S. Pat. No. 4,243,770 and U.S. Pat. No. 4,943,622). It is also possible to use as chain transfer agents iodides and/or bromides of alkaline or alkaline-earth metals, according to U.S. Pat. No. 5,173,553.
Preferably the crosslinking of radical type uses ionomers containing units of the bis-olefin of formula (I) and iodine in terminal position.
The sulphonic ionomer of the invention is crosslinked by radical route at a temperature in the range 100° C.-200° C., depending on the type of type used peroxide, by addition of a suitable peroxide capable to generate radicals by heating. Generally, the peroxide amount is in the range 0.1%-5% by weight with respect to the polymer. Among them it can be mentioned: dialkylperoxides, such as for example di-terbutyl-peroxide and 2,5-dimethyl-2,5-di(terbutylperoxy)hexane; dicumyl peroxide; dibenzoyl peroxide; diterbutyl perbenzoate; di-1,3-dimethyl-3-(terbutylperoxy)butylcarbonate. Other peroxidic systems are described, for example in the patent applications EP 136,596 and EP 410,351.
Besides it can be added before the crosslinking:
(a) a crosslinking co-agent, in an amount in the range 0.5-10%, preferably 1-7% by weight with respect to the polymer; among them it can be mentioned: triallyl-cyanurate; triallyl-isocyanurate (TAIC); tris(diallylamine)-s-triazine; triallylphosphite; N,N-diallyl-acrylamide; N,N,N′,N′-tetrallyl-malonamide; trivinyl-isocyanurate; 2,4,6-trivinyl-methyltrisiloxane; N,N′bisallylbicyclo-oct-7-ene-disuccinimide (BOSA); bis olefin of formula (I), triazine;
(b) a metal compound, in amounts in the range 1-15%, preferably 2-10%, by weight with respect to the polymer, selected from oxides or hydroxides of divalent metals, such as for example Mg, Zn, Ca or Pb, optionally combined with a weak acid salt, such as for example stearates, benzoates, carbonates, oxalates or phosphites of Ba, Na, K, Pb, Ca;
(c) other conventional additives, such as thickeners, pigments, antioxidants, stabilizers and the like;
(d) inorganic or polymer reinforcing fillers, preferably optionally fibrillable PTFE. Preferably fillers have a size from 10 to 100 nm, preferably 10-60 nm.
A further object of the present invention is that the sulphonic ionomer can be mixed with a fluoroelastomer, preferably perfluoroelastomer, co-curable with the sulphonic ionomer of the invention. Preferably for the co-curing the fluoroelastomer contains iodine and/or bromine atoms. A TFE-/perfluoromethylvinylether copolymer having a ratio by moles in the range 80:20-60:40 of the type described in EP 661,304 in an amount comprised between 0-50% by weight with respect to the polymer, can for example be mentioned.
The ionomer and fluoroelastomer mixture can for example be a physical blend of solid polymers or of polymerization latexes. In this case the percentages of peroxides are to be referred to the ionomer and fluoroelastomer mixture. Also for the optional agents the percentages are to be referred to said mixture.
The crosslinking blend is prepared by using mechanical mixers.
The sulphonic fluorinated ionomers of the invention can be used for the preparation both of self-supported membranes and membranes supported on suitable support.
The self-supported membranes are obtained by subjecting the blend to a molding, extrusion or calendering process to obtain a film of the desired thickness, at a temperature lower than or equal to the temperature at which crosslinking takes place. When the film is obtained at a temperature lower than the crosslinking temperature, a thermal treatment is necessary to complete the crosslinking.
When the membranes are supported, as support, a fluorinated, preferably perfluorinated, porous material, having the desired size and thickness, can be used. In this case the sulphonic ionomer under the form of latex or of solution is crosslinked as above indicated, after being deposited on the support.
The crosslinked membranes of the invention are subjected to the activation treatment to transform the sulphonyl groups —SO 2 F into sulphonic groups —SO 3 H. For example activation can be carried out in 2 steps:
salification to transform the —SO 2 F form into the —SO 3 K form;
acidification to transform the —SO 3 K form into the —SO 3 H form.
For example the salification is carried out by immersing the membrane obtained after the crosslinking reaction in an aqueous solution containing 10% by weight of KOH at a temperature in the range 60° C.-80° C. for a time higher than 2 hours. When the salification is over, the membrane is immersed into a distilled water bath at room temperature to wash the residual KOH. THe acidification is carried out for example by placing the salified membrane in an aqueous solution containing 20% by weight of HCl at room temperature for at least 2 hours.
The resulting membrane in the —SO 3 H form is suitable to be used in fuel cell applications.
The membranes obtained with ionomers having a low equivalent weight (lower than 750 g/eq) show a high hydration percentage. However this high hydration percentage does not compromise the substantial physical integrity of the membrane. Indeed by immersing the crosslinked membrane of the invention at 100° C. in water the membrane maintains integrity. On the contrary the uncrosslinked membranes subjected to the same treatment disintegrate or dissolve thus losing any physical integrity (see the Examples).
Apart from the preparation of membranes for fuel cells, the sulphonic ionomers of the present invention can successfully be used in the preparation of membranes used in electrochemical applications, such as for example chloro-alkali cells, lithium batteries, and electrodialysis and in reactors in which the ionomeric membrane acts as a superacid catalyst.
With the crosslinking system of the present invention, the crosslinking does not involve the sulphonyl groups —SO 2 F of the various polymer chains. In this way there is no reduction of the sulphonyl groups —SO 2 F available for the conversion into the sulphonic groups —SO 3 H. Consequently, with the crosslinking of the present invention there is not the drawback of a reduction of the sulphonic groups with consequent increase of the equivalent weight and consequent lowering of the ionic conductivity.
After the crosslinking step, the iodine, when present, can optionally be eliminated by a thermal post-treatment. Said post-treatment is carried out at a temperature preferably in the range 200° C.-250° C., temperature at which the break of the C—I bonds takes place with consequent iodine elimination.
The polymerization of the monomers can be carried out in aqueous emulsion according to well known methods of the prior art, in the presence of radical initiators (for example alkaline or ammonium persulphates, perphosphates, perborates or percarbonates), optionally in combination with ferrous, cuprous or silver salts, or other easily oxidizable metals. In the reaction medium also surfactants of various type are usually present, among which the fluorinated surfactants of formula:
R f —X − M +
are particularly preferred, wherein R f is a C 5 -C 16 (per)fluoro-alkyl chain or a (per)fluoropolyoxyalkylene chain, X − is —COO − or —SO 3 − , M + is selected from: H + , NH 4 + , alkaline metal ion. Among the most commonly used we remember: ammonium perfluoro-octanoate, (per)fluoropolyoxyalkylenes ended with one or more carboxyl groups, etc.
When the polymerization is over, the ionomer is isolated by conventional methods, such as coagulation by addition of electrolytes or by cooling.
Alternatively, the polymerization reaction can be carried out in bulk or in suspension, in an organic liquid wherein a suitable radical initiator is present, according to well known techniques.
The polymerization reaction is generally carried out at temperatures in the range 25°-120° C., under pressure up to 3 MPa.
The preparation of the sulphonic ionomers of the present invention is preferably carried out by using a dispersion or microemulsion of perfluoropolyoxyalkylenes, according to U.S. Pat. No. 4,789,717 and U.S. Pat. No. 4,864,006.
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be now better illustrated by the following embodiment Examples, which have a merely indicative but not limitative purpose of the scope of the invention itself.
EXAMPLES
Characterization
Hydration Percentage
After drying the membrane is weighed and subsequently hydrated in distilled water at 100° C. for 30 minutes; then it is extracted from water, dried on the surface and weighed again.
The hydration percentage H % of the membrane is evaluated according to the following formula:
H %=100×(hydrated weight-dried weight)/dried weight
Extractable Substance Percentage
The membrane is first weighed and then placed in a solution of ethanol/water 40/60 by weight at 50° C. for 22 hours. Subsequently the solution is filtered on a Whatman 541 filter. The filtered product is dried at 80° C. and the dry residue is weighed. The percentage E % of extractable substance is determined according to the following formula:
E %=100×(dry residue weight/initial membrane weight)
Release Temperature of Bound Water
The release temperature T r of the water bound to the groups —SO 3 H is evaluated by thermogravimetric analysis (TGA).
An amount of about 10 mg of the hydrated membrane in water, distilled at 100° C. for 30 minutes, is analyzed in a thremogravimetric analyser Perkin Elmer model TGA7. After having been maintained in N 2 flow at room temperature, the sample is heated with a temperature gradient of 10° C./minute up to 80° C., temperature at which it is maintained for 5 minutes. Subsequently the sample is cooled at the same rate until room temperature at which it is maintained for 10 minutes. Then the thermogravimetric analysis starts by heating the sample at a rate of 10° C./minute.
The TGA curve allows to go back to the value of the release temperature T r in correspondence of the first minimum of the derivative of the TGA curve. The higher the temperature T r , the greater the capability of the membrane to keep water and consequently to lead also to high temperatures.
Example 1
In a 2 liter autoclave, the following reactants are introduced:
700 ml of demineralized water;
45 ml of the monomer of formula
CF 2 ═CF—O—CF 2 CF 2 —SO 2 F;
29 g of a perfluoropolyoxyalkylene microemulsion previously obtained by mixing:
11.6 g of a perfluoropolyoxyalkylene having a potassium salified acid end group of formula:
CF 2 ClO(CF 2 —CF(CF 3 )O) n (CF 2 O) m CF 2 COOK
wherein n/m=10 having average molecular weight 527;
5.8 g of a perfluoropolyether oil Galden® D02 of formula
CF 3 O(CF 2 —CF(CF 3 )O) n (CF 2 O) m CF 3
wherein n/m=20 having average molecular weight 450
11.6 g of water;
5.7 ml of a solution at 33% by volume of an iodinated transfer agent of formula
I—(CF 2 ) 6 —I
in a perfluoropolyether solvent Galdens® D02;
1.5 ml of a solution at 1.5% by volume of the bis-olefin of formula
CH 2 ═CH—(CF 2 ) 6 —CH═CH 2
in a solvent Galden® D02.
The autoclave, kept under stirring at 700 rpm, has been heated up to 50° C. 400 ml of an aqueous solution at 20 g/l concentration of potassium persulphate (KPS), are then fed to the autoclave. The pressure is brought to 3 absolute bar by introducing TFE. The reaction starts after 3 minutes. The pressure is maintained at 3 absolute bar by feeding TFE. During the polymerization, 7.5 ml of the sulphonyl monomer of formula
CF 2 ═CF—O—CF 2 CF 2 —SO 2 F
and 1.5 ml of a solution at 1.5% by volume of the bisolefin of formula
CH 2 ═CH—(CF 2 ) 6 —CH═CH 2
in a solvent Galden® D02 are added every 6.5 g of fed TFE. The total TFE mass fed to the reactor is equal to 88 g. The reaction is stopped after 280 minutes from the start, by lessening the stirring, cooling the reactor and venting the TFE. The produced latex has a solid content of 25% by weight. The latex is coagulated by freezing, the polymer is separated from the mother liquors and dried at 100° C. for 8 hours at room pressure. The copolymer composition determined by NMR results to be 69% by moles of TFE and 31% by moles of sulphonyl monomer, corresponding to an equivalent weight of 500 g/eq. The iodine content by weight in the ionomer, measured by X ray fluorescence (XRF) is 0.25%.
For the subsequent crosslinking step, 50 g of the obtained ionomer are mixed in an open mixer with 0.5 g of 2,5-dimethyl-2,5-di(terbutylperoxy)hexane (Luperox®101 XL) and with 0.5 g of TAIC Drymix® both supported on silica. 2% by weight of a mixture silica/metal oxides (Celite® 350) is furthermore added.
About 10 g of blend are molded in press at 150° C. for 20 minutes by applying a pressure of 200 bar.
A portion of the resulting film, weighing 4.90 g, is subjected to a salification treatment for 5 hours 30 minutes at 60° C. in an aqueous solution of KOH at 10% by weight. It is then washed in demineralized water and treated for the acidification for 16 h at room temperature in an aqueous solution of HCl at 20% by weight and washed again in demineralized water. The previous salification and acidification treatment implies the complete transformation, within the limits detectable by the FTIR analysis, of the —SO 2 F groups into sulphonic groups —SO 3 H.
The so obtained ionomeric membrane is dried for 2 hours at 110° C. At the end the membrane has a weight of 4.81 g corresponding to 2% of weight loss with respect to the initial film. The membrane has physical integrity also after immersing it in water at 100° C.
The extractable substance percentage E % is 22%. This measure is repeated a second time confirming the same value.
The release temperature T r of the water bound to the —SO 3 H groups is 164° C.
Example 2
50 g of the ionomer obtained as in Example 1 are mixed in an open mixer with 2.7 g of a perfluoroelastomer copolymer TFE/perfluoromethylvinylether (MVE 32% by moles, bis-olefin of Example 1 0.08% by moles, iodine 0.32% by weight). Luperox® and TAIC both supported on silica are incorporated in the blend in an amount equal to 1.2% and 2% by weight with respect to the total amount of ionomer+perfluoroelastomer. Celite® 350 is added in an amount equal to 1.2% by weight. About 10 g of blend are molded in press at 150° C. for 20 minutes applying a pressure of 200 bar. A rectangle of the resulting film, having 3.6 cm×4.2 cm sides, weight 0.48 g and thickness 150 μm, is salified for 2 hours 40 minutes at 65° C. in an aqueous solution of KOH at 10% by weight, and then washed in demineralized water. Then the film is acidified for 23 hours at room temperature in an aqueous solution of HCl at 20% by weight and at last washed in demineralized water. The activation treatment implies the complete transformation of the —SO 2 F groups into sulphonic groups —SO 3 H.
The obtained membrane is hydrated at 100° C. for 30 minutes and then dried for 2 hours at 110° C. At the end the membrane has a weight of 0.43 g, corresponding to 10% of weight loss with respect to the initial film.
Example 3
50 g of the ionomer obtained as in Example 1 have been mixed in an open mixer with 8.8 g of the perfluoroelastomer of Example 2.
Luperox® and TAIC both supported on silica are incorporated in the blend in an amount equal to 1.2% and 2% by weight with respect to the total amount of ionomer+perfluoroelastomer. Celite® 350 is added in an amount equal to 1.2% by weight.
About 10 g of blend are molded in press at 150° C. for 20 minutes applying a pressure of 200 bar. A rectangle of the resulting film, having 3.8 cm×4.4 cm sides, weight 0.49 g and thickness 140 μm, is salified for 2 hours at 65° C. in an aqueous solution of KOH at 10% by weight, and washed in demineralized water. It is then acidified for 2 hours and 30 minutes at room temperature in an aqueous solution of HCl at 20% by weight and at last washed in demineralized water. The previous activation treatment implies the complete transformation of the —SO 2 F groups into sulphonic groups —SO 3 H.
The obtained membrane is hydrated at 100° C. for 30 minutes and then dried for 2 hours at 110° C. At the end the membrane has a weight of 0.46 g, corresponding to 6% of weight loss with respect to the initial membrane. The membrane has physical integrity also after immersing it in water at 100° C.
The extractable substance percentage E % is 15%.
The release temperature T r of the water bound to the —SO 3 H groups is 169° C.
Example 4
50 g of the ionomer obtained as in Example 1 have been mixed in an open mixer with 16.7 g of the perfluoroelastomer of Example 2.
Luperox® and TAIC both supported on silica are incorporated in the blend in an amount equal to 1.2% and 2% by weight with respect to the total amount of ionomer+perfluoroelastomer. Celite® 350 is added in an amount equal to 1.2% by weight.
About 10 g of blend have been molded in press at 150° C. for 20 minutes applying a pressure of 200 bar. A rectangle of the resulting film, having 3.8 cm×4.0 cm sides, weight 0.55 g and thickness 170 μm, is salified for 2 hours at 65° C. in an aqueous solution of KOH at 10% by weight, and washed in demineralized water. The film is then acidified for 1 hours 40 minutes at room temperature in an aqueous solution of HCl at 20% by weight and at last washed in demineralized water.
The previous activation treatment implies the complete transformation of the —SO 2 F groups into acid sulphonic groups.
The obtained membrane is hydrated at 100° C. for 30 minutes and then dried for 2 hours at 110° C. At the end the membrane has a weight of 0.52 g, corresponding to 5% of weight loss with respect to the initial film. The membrane has physical integrity also after immersing it in water at 100° C.
The extractable substance percentage E % is 4%.
The release temperature T r of the water bound to the —SO 3 H groups is 140° C.
Example 5
About 10 g of the blend containing the same ionomer and the same components of Example 4 have been molded in press at 150° C. for 20 minutes by applying a pressure of 200 bar. A rectangle of the resulting film, having 6.1 cm×9.3 cm sides, weight 2.18 g and thickness 180 μm, is salified for 5 hours at 65° C. in an aqueous solution of KOH at 10% by weight, and washed in demineralized water. The film is subsequently acidified for 17 hours at room temperature in an aqueous solution of HCl at 20% by weight and at last washed in demineralized water.
The obtained membrane is hydrated at 80° C. for 30 minutes. After hydration it results to have a thickness of about 320 μm. It is placed in a test fuel cell, fed at the anode with hydrogen at 3.5 bar and fed at the cathode with air at 4 bar. At a temperature of 70° C., the current corresponding to a voltage of 0.7 V is of 500 mA/cm 2 . The slope of the straight portion of the voltage-current curve (resistance) is of R=0.425 ohm cm 2 . The thickness of the hydrated membrane being known, this resistance value allows to determine a conductivity value for the membrane of 7.5×10 −2 S/cm.
Example 6
About 10 g of the blend containing the same ionomer and the same components of Example 4 have been molded in press at 150° C. for 20 minutes, applying a pressure of 200 bar. The resulting film has been treated in a stove for 22 hours at 230° C. After this treatment iodine is no longer detectable by the XRF analysis. A rectangle of the so treated film, having 5.1 cm×5.9 cm sides, weight 1.00 g and thickness 150 μm, is salified for 3.5 hours at 65° C. in an aqueous solution of KOH at 10% by weight, and washed in demineralized water. The film is subsequently acidified for 10 hours at room temperature in an aqueous solution of HCl at 20% by weight and at last washed in demineralized water.
The obtained membrane is hydrated at 80° C. for 30 minutes. After hydration it results to have a thickness of about 270 μm. It is placed in a test fuel cell, fed at the anode with hydrogen at 3.5 bar and fed at the catode with air at 4 bar. At a temperature of 70° C., the current corresponding to a voltage of 0.7 V is of 580 mA/cm 2 . The slope of the straight portion of the voltage-current curve (resistance) is of R=0.313 ohm cm 2 . The thickness of the hydrated membrane being known, this resistance value allows to determine a conductivity value for the membrane of 8.6×10 −2 S/cm.
Example 7
Comparative
About 10 g of the ionomer of Example 1 are molded in press at 80° C. for 5 minutes, applying a pressure of 200 bar. A rectangle of the resulting film, weighing 2.2 g and having a thickness of 220 μm, is salified for 4 hours at 65° C. in an aqueous solution of KOH at 10% by weight, and washed in demineralized water, then acidified for 8 hours at room temperature in an aqueous solution of HCl at 20% by weight and at last washed in demineralized water. The obtained membrane immersed in water and brought to 50° C., completely dissolves.
The results of the Examples show that the crosslinked membranes of the present invention under the form of —SO 3 H show physical integrity even after immersion in water at 100° C. according to the test indicated in the Examples. | Crosslinked sulphonic fluorinated ionomers having an equivalent weight 380-1300 g/eq, comprising:
(A) monomeric units deriving from one or more fluorinated monomers containing at least one ethylene unsaturation;
(B) fluorinated monomeric units containing sulphonyl groups —SO 2 F in an amount such as to give the above indicated equivalent weight. | 8 |
FIELD OF THE INVENTION
[0001] The present invention relates to base band filters and filtering methods. In particular, the present invention relates to base band filters and methods that filter base band signals in the time domain and include a filter transfer function.
BACKGROUND OF THE INVENTION
[0002] Wireless communication systems typically include transmitters that have to generate signals which are strictly limited to the specified frequency channel in order to avoid interference with other users. For this reason, the transmitters typically have radio frequency filters in order to attenuate interference signals between different communication systems such as GSM (global system for mobile communication) and the transmitting and receiving channels within a system. The interference between different users operating within the same channel is limited by the use of base band filters. Since the maximum data transfer speed is correlated to the performance of the base band filters, they can become a bottleneck of the performance of the whole system and further result in high circuit complexity.
[0003] Current state-of-the-art implementation would be to use in the transmitter a base band filter having a small amplitude variation, e.g. 0.1 dB ripple, in the pass band or the frequency band which is occupied by the wanted signal. The stop band attenuation is usually specified by regulations which define the spectral purity so as to typically limit the maximum out-of-band spectral power which otherwise can harm other radio frequency usage. A main problem is that small amplitude ripple in pass band and typically high requirement for stop band attenuation result in the provision of a filter apparatus having a long impulse response in time domain, which means that the signal energy will be distributed in time domain so that part of the energy which is in one transmitted symbol may leak to the next symbol causing inter-symbol-interference.
[0004] Both digital and analog base band filters have a trade-off between a wanted behavior e.g. with regard to base-band spectral flatness and stop-band attenuation, an unwanted behavior e.g. with regard to a distortion of the signal and the length of the impulse response of the filter apparatus and the complexity of the filter apparatus. High order filters result in low amplitude variation in the pass-band and high stop-band rejection, but also have a long impulse response which spreads the filtered signal energy in time domain, and further require complex circuitry. A system with low order filtering, however, results in poor spectral efficiency, since the separation between different users in frequency domain must be increased to avoid interference. On the other hand, long impulse responses created by high order filtering cause signal spreading in time domain, which results in inter-symbol interference or requires longer guard intervals between transmitted symbols, both of which limit the speed of the data transfer.
SUMMARY OF THE INVENTION
[0005] Aspects of the invention overcome problems and limitations of the prior art by providing systems and methods that provide an improved way for implementation of a base band filtering with better performance and lower circuit complexity.
[0006] In one aspect of the present invention, there is provided a base band filter apparatus comprising filter means for filtering a base band signal in time domain, said filter means having a filter transfer function, further characterized by means for providing the base band signal in frequency domain, multiplying means for multiplying said frequency domain base band signal by an inverse filter transfer function of said filter means, and frequency-to-time domain conversion means for converting the output of said multiplying means from frequency domain to time domain and providing said time domain signal to said filtering means.
[0007] According to a second aspect of the present invention, there is provided a method for base band filtering, comprising the step of: filtering a base band signal in time domain, said filtering including a filter transfer function, characterized by the further steps of: providing the base band signal in frequency domain, multiplying said frequency domain base band signal by an inverse filter transfer function, and converting the signal provided as the result of said multiplying step from frequency domain to time domain and providing said time domain signal to the filtering step.
[0008] With embodiments of the present invention, it is possible to implement base band filtering with equivalent or better amplitude response with lower circuit complexity or with significantly better amplitude response with equivalent circuit complexity, compared to conventional base band filtering. Further, embodiments of the present invention result in a reduction of the impulse response length of a base band with given filtering performance. Moreover, it is possible with various embodiments the present invention to filter in and near band interferences generated e.g. by discontinuity between symbols since the filter can have attenuation on the pass-band, which was not possible with the conventional base band filtering. Finally, embodiments of the present invention offer more degree of freedom in the design since the transfer function can vary a lot in arbitrary ways within the pass band. Hence, it may be possible to generate e.g. special stop band notches which can improve the filtering performance.
[0009] Furthermore, embodiments of the present invention provide for a simpler filtering wherein a significantly greater amplitude response variation in the pass band is allowed while maintaining a large enough attenuation in the stop band. In order to essentially maintain the original frequency response of the base band, the base band signal is wanted in frequency domain and multiplied by the inverse transfer function of the filtering in frequency domain. Namely, it has been found that the multiplication is to be done in frequency domain, e.g. before the frequency-to-time conversion is necessary, in order to prevent a distortion of the signal. The multiplication can be done at any point before the signal is in time domain. In certain embodiments the multiplication is done as close to the frequency-to-time domain conversion as possible.
[0010] Moreover, embodiments of the present invention provide ways to generate a base band frequency domain transfer function equivalent to the case where high order base band digital time domain filters and/or analog filters are used along with the use of lower order filters.
[0011] Filters designed in accordance with at least some of the embodiments of the invention may result in reduced power consumption.
[0012] Embodiments of the present invention can be implemented optionally for digital or analog filtering.
[0013] Embodiments of the present invention can be used in wireless systems and have in particular great benefit in the implementation of WLAN (wireless local area network), WIMAX, EUTRA, UWB and other OFDM (orthogonal frequency division multiplexing) and SC-FDMA (single-carrier frequency division multiple access) based transmitters in mobile terminals, base stations etc. However, the present invention is not limited to such special applications, but can be used, for example, for base band signal generation in general.
[0014] In one embodiment, if the amplitude response of the filtering is to be compensated only, it is sufficient that the inverse filter transfer function includes at least one coefficient being a real number. However, if both the amplitude and phase response need to be compensated, the inverse filter transfer function may include at least one coefficient which is a complex number.
[0015] In addition to simplifying a single filtering by means of embodiments of the present invention, it is also possible to simplify several filters, wherein the filter means comprises a plurality of filters or the filtering step comprises a plurality of filtering processes, each filter/filtering process having an individual filter transfer function, and the frequency domain base band signal is multiplicated by a coefficient vector including the inverse filter transfer functions of all the filters/filtering processes. In the latter embodiments, the frequency domain base band signal may be a vector including a plurality of complex numbers representing a sample or symbol of the base band signal. If the representation of the multiplication result requires more bits than the frequency domain base band signal vector before multiplication, one option is to have the multiplication as close to the frequency-to-time domain conversion as possible.
[0016] The frequency-to-time domain conversion may be carried out by an inverse fast fourier transform process. As pointed out above, the implementation according to at least some embodiments of the present invention requires that the base band signal is represented in frequency domain before the filtering. In systems, where the base band signal is in time domain, a time-to-frequency domain conversion may be utilized in order to provide the base band signal in frequency domain. The time-to-frequency domain conversion may be carried out by a fast fourier transform process.
[0017] Embodiments of the present invention can be implemented in a transmitter using a cyclic prefix, wherein, after a symbol in a signal transmitted by said transmitter is converted from frequency domain to time domain, a part of said signal from the end is copied to the beginning of said symbol.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The present invention will be readily understood by the following detailed description in conjunction with the accompanying drawings, wherein like reference numerals designate like structural elements, and in which
[0019] FIG. 1 is a block diagram of a frequency domain enhanced base band filtering according to a first embodiment of the present invention;
[0020] FIG. 2 shows a portion of FIG. 1 ;
[0021] FIG. 3 is a block diagram of a frequency domain enhanced base band filtering in systems with time domain base band signal generation according to a second embodiment of the present invention;
[0022] FIG. 4 is a graph showing an amplitude versus frequency response of a 65 tap FIR low-pass filter;
[0023] FIG. 5 is a graph showing an amplitude versus frequency response of a 22 tap FIR low-pass filter;
[0024] FIG. 6 is graph showing the impulse response of the 65 tap FIR low-pass filter;
[0025] FIG. 7 is graph showing the impulse response of the 22 tap FIR low-pass filter;
[0026] FIG. 8 is a graph showing an OFDM base band spectrum of 600 sub-carriers with 15 kHz sub-carrier offset at Nyquist frequency using reference filtering with the 65 tap FIR low-pass filter and an enhanced filtering with the 22 tap FIR low-pass filter; and
[0027] FIG. 9 shows an enlarged extract portion of FIG. 8 .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0028] FIG. 1 shows a simplified block diagram of a frequency domain enhanced base band filtering according to an embodiment of the present invention. Starting from the base band signal generation and ending at a radio frequency transmitter. After a modulation, the base band signal is provided in frequency domain. In this embodiment, the way of obtaining a simpler filtering, either in digital or analog domain, is to allow significantly greater amplitude variation in the pass band of the filter while maintaining a large enough attenuation in the stop band. In order to maintain the original frequency response of the base band, the frequency domain base band signal after modulation is multiplied by an inverse transfer function of the simplified filtering in frequency domain. In FIG. 1 , the inverse transfer function is shown as a coefficient vector F −1 ANA (f) (analog domain) and F −1 DIG (f) (digital domain). In the following, the filter used for the simplified filtering will be referred to as “enhanced” or “simplified” filter.
[0029] As further shown in FIG. 1 , the signal which consists of the result of the multiplication is converted from frequency domain to time domain by an inverse fast fourier transform process. This process is carried out in a circuit element IFFT of FIG. 1 . The output of the IFFT is a time domain signal. The process carried out in the embodiment shown in FIG. 1 and described so far has been done in the digital domain.
[0030] According to the embodiment shown in FIG. 1 , a cyclic prefix is added to the output of the IFFT in the time domain. The addition of a cyclic prefix in this part of the base band processing does not have an impact on the transmitter. Namely, the addition of a cyclic prefix to a or each symbol solves both inter-symbol-interferences and inter-channel-interferences. Assuming that the channel impulse response has a known length L, the prefix consists simply of copying the last L-1 values from each symbol and appending them in the same order to the front of the symbol. By doing so, the convolution of the impulse response with the signal at the end of a symbol does not affect any of the actual data at the beginning of the next symbol. The above described enhanced filtering can be implemented in transmitters which use a cyclic prefix, wherein, after a symbol in the transmitted signal is converted from frequency to time domain, a part of the signal from the end is copied to the beginning of the symbol.
[0031] The embodiment of FIG. 1 further comprises a digital low pass filter LPF having a digital filter transfer function F DIG (t) in time domain wherein the time domain output signal of IFFT is input. The output of the low pass filter LPF is converted from digital to analog domain by a digital-to-analog converter DAC and thereafter input into an analog low pass filter LPF having an analog filter transfer function F ANA (t). The output of the analog low pass filter LPF is finally transmitted by the radio frequency transmitter designated in FIG. 1 as RF transmitter.
[0032] In addition to simplifying a filter that includes a single filter element, it is also possible to simplify a filter that consists of several filter elements and multiply the frequency domain signal with a coefficient vector where the inverse transfer function of all filter elements are combined. A digital base band filter that is enhanced can also operate at an oversampled frequency.
[0033] Let Y be a vector with n complex numbers representing a base band signal sample (symbol) in frequency domain. Respectively, A is the coefficient vector to compensate the filter transfer function, with n real or complex numbers. Real numbers can be used if only the amplitude response of the filter is compensated; complex numbers can be used if both the amplitude and phase response need to be compensated. X is the frequency domain compensated base band signal which is generated by multiplication of A and Y, as shown as follows:
[0000]
x
2
=a
1
·y
1
[0000]
x
2
=a
2
·y
2
[0000]
X =Ā· Y
[0000] or
[0000]
x
n−1
=a
n−1
·y
n−1
[0000]
x
n
=a
n
·y
n
[0034] The coefficients x n , a n , and y n are at the same base band frequency; i.e. a n represents the filter inverse transfer function at the same frequency as x n ; and y represents the base band signal. This is shown in FIG. 2 .
[0035] A represents the required samples from the inverse of the filter frequency domain transfer function. In case of multiple filters, A is the product of the transfer functions of those filters.
[0036] The multiplication can be done at any point before the signal is in time domain. It may be best to have the multiplication as close to the signal conversion from frequency to time domain if the representation of X requires more bits than Y.
[0037] The implementation requires that the base band signal is represented in frequency domain before the filtering. In systems where the base band signal is generated in time domain, it is possible to make a time-to-frequency domain conversion such as fast fourier transform process carried out by a circuit element FFT, and then complete the compensation in the same way, as described above, and to convert the signal back to time domain as shown in FIG. 3 .
[0038] The operation of the base band filtering in accordance with embodiments of the invention is demonstrated by two simulations of an OFDM base band signal generation with traditional base band filtering and with the enhanced base band filtering, with reference to FIGS. 4 to 9 . Both cases are using QPSK modulated OFDM with 600 sub-carriers with 15 kHz spacing i.e. the 10 MHz channel bandwidth case of EUTRA downlink transmission. The base band clocking frequency is 15.36 MHz. The reference case uses a 65 tap Nyquist rate FIR (finite impulse response) filter with 0.1 dB pass band variation and 38 dB stop band attenuation. The enhanced case uses a 22 tap Nyquist rate FIR filter with 10 dB pass band variation and 38 dB stop band attenuation. The amplitude response of these filters is shown in FIG. 4 and FIG. 5 . The enhanced filter has not been optimized for this case but was chosen as an example of what could be easily possible to implement.
[0039] The impulse responses of the reference and enhanced filter are shown in FIG. 6 and FIG. 7 . The impulse response of the filter defines how the filtered signal energy spreads in time. The signal spreading is highly unwanted for example in OFDM since it increases the inter-symbol interference and therefore limits the maximum achievable data rates. The impulse response of the enhanced filter is only about one third of the reference case.
[0040] FIG. 8 shows the spectra of the two base band signal cases overlapped in the same figure. The reference signal has a worse performance on the transition region from pass band to stop band. As can be seen, there is no significant difference in the pass band and stop band attenuation so that the performance of the filters is equally good at those areas. The noise in the stop band is larger for the reference case, but the minimum attenuation in the stop band is very similar.
[0041] FIG. 9 shows a close-up of FIG. 8 . In OFDM there are discontinuities of the signal in time domain between the modulated symbols which causes signal spreading which can be regarded as noise or interference occurring both on the transmit channel and the adjacent channel. Since the enhanced filter affects this interference already starting from the pass band, the performance is better in the transition band. As an example, the better filtering in the transition band can be used to increase the number of subcarriers in OFDM.
[0042] The better base band performance achieved by enhanced filtering can be used to improve the spectrum efficiency, i.e. the data transfer speed in communication systems. It is also possible to trade off the good base band performance to ease the implementation of other transmitter parts such as the power amplifier and the clipping algorithms.
[0043] Other base band signal processing, e.g. signal clipping and pre-distortion, should take into account that the base band signal has been altered between the multiplication and the last enhanced filter if it modifies the signal at this part of the base band chain.
[0044] Embodiments of the invention may require an increased number of bits to represent the frequency domain signal after the multiplication with the coefficient vector. The accuracy of the base band signal in time domain depends on the number of used bits after the multiplication.
[0045] Finally, it should be noted that the above preferred descriptions are of preferred examples for implementing embodiments of the present invention, but the scope of the present invention should not necessarily be limited by this description. It will be apparent to those skilled in the art that a person understanding this invention may conceive of changes or other embodiments or variations, which utilize the principles of this invention without departing from the broader spirit and scope of the invention as set forth in the appended claims. All are considered within the sphere, spirit, and scope of the invention. | Disclosed is a base band filter apparatus and a method for base band filtering comprising filtering a base band signal in time domain, said filtering including a filter transfer function (F), wherein the base band signal is provided in frequency domain, the frequency domain base band signal is multiplicated by an inverse filter transfer function (F −1 ), and the signal provided as the result of said multiplication is converted from frequency domain to time domain and provided to said filtering. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. provisional application no. 60/262,154 filed Jan. 17, 2001, and U.S. provisional application no. 60/285,179 filed Apr. 20, 2001.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to protectant application to carpets and fabrics. In one of its aspects, the invention relates to a hand-held nozzle attachment for an upright deep cleaner or extractor. In another of its aspects, the invention relates to an upright deep cleaner or extractor with spray applicator for applying a solution, such as stain repellant or other treatment, to a surface. In another of its aspects, the invention relates to a method for applying a liquid protectant to a carpet or fabric surface.
[0004] 2. Description of the Related Art
[0005] Upright deep cleaners or extractors are disclosed in U.S. Pat. Nos. 6,041,472 and 6,081,962. These prior art upright deep cleaners include an above-floor cleaning nozzle fluidly connected to the cleaner by vacuum and fluid delivery conduits, for applying a cleaning solution to an above-floor surface being cleaned and for extracting fluid from the surface being cleaned after application of the cleaning solution. The cleaning solution applied to the surface being cleaned is generally a mixture of water and a detergent. The mixture is either combined in a mixing valve in the body of the deep cleaner or in a clean solution tank of the deep cleaner. The solution is then pumped through the fluid delivery conduit either to the floor or to an above-floor surface being cleaned. The operator of the upright deep cleaner also has the option of omitting the detergent solution so that only water is pumped through the fluid delivery conduit.
[0006] After deep cleaning of a floor or above-floor surface with a deep cleaner, such as an upright deep cleaner, it is desirable in many cases to apply or refresh a protective coating, such as a stain repellant or other treatment, to the surface cleaned. Scotchgard™ by 3M™ is one such known treatment. Prior art devices, separate from the upright deep cleaner, are known for this purpose.
[0007] It would be advantageous to remove the requirement for a separate protectant-applying machine and take advantage of the capabilities of the upright deep cleaner that is already in use, and already at the location of the surface to be treated, to apply a protectant or other treatment to the cleaned surface.
SUMMARY OF THE INVENTION
[0008] According to the invention, a portable surface cleaning apparatus comprises a base housing adapted for movement along a surface to be cleaned, an upright handle pivotally mounted to the base housing, a liquid dispensing system mounted at least in part to the base housing and including a fluid supply tank, a liquid recovery system including an above-floor hose fluidly connected at one end to a recovery tank and having an open end, the above-floor hose carrying a liquid supply conduit and mounting an above-floor liquid dispenser including a spray nozzle at the open end thereof. According to the invention, a fluid reservoir is mounted to the above-floor liquid dispenser for dispensing a fluid onto a surface and a fluid reservoir pump is mounted to the above-floor liquid dispenser for drawing fluid from the reservoir and for spraying the fluid onto the surface along with fluid from the liquid supply tank.
[0009] The liquid dispensing system typically can be the type that includes a floor liquid dispenser associated with the base housing for applying liquid to a floor surface to be cleaned, a liquid supply tank for holding a supply of cleaning liquid, a liquid supply conduit fluidly connected to the liquid supply tank and to a floor liquid dispenser for supplying a cleaning fluid to the floor dispenser.
[0010] The liquid recovery system is typically of the type that includes a recovery tank mounted on the base housing and having a liquid recovery chamber for holding recovered liquid, a suction nozzle associated with the base housing and adapted to draw dirty liquid from the surface to be cleaned, a working air conduit extending between the recovery chamber and the suction nozzle and a vacuum source in fluid communication with the recovery chamber for generating a flow of working air from the nozzle through the working air conduit, or alternatively from the open end of the above-floor hose, and through the recovery chamber to thereby draw dirty liquid from the surface to be cleaned through the nozzle and working air conduit, or from the open end of the above-floor hose and into the recovery chamber to thereby recover the dirty liquid from the surface to be cleaned.
[0011] In one embodiment, the liquid recovery system further comprises a switch for selectively operating the vacuum source independent of the pump.
[0012] Preferably, the fluid reservoir pump is an aspirator. Further, the above-floor liquid dispenser is without a suction nozzle opening and preferably has a vent opening for venting suction in the hose to the atmosphere.
[0013] In a preferred embodiment, the above-floor liquid dispenser and the reservoir have a quick connect mechanism for removably mounting the reservoir to the second liquid dispenser. The quick connect mechanism includes an open neck on an upper portion of the reservoir. Further, a cap is adapted to mount to the open neck of the reservoir when the reservoir is removed from the above-floor liquid dispenser for sealing the reservoir when the reservoir is removed from the above-floor liquid dispenser. In one embodiment, the neck is threaded and the cap is threaded onto the neck. Further, the reservoir is vented through the threads on the neck. The quick connect can take a number of different forms and in a preferred embodiment is a bayonet connection.
[0014] The invention is designed to spray a liquid surface protectant composition onto a carpet or fabric surface. To this end, a body of a liquid surface protectant composition is in the reservoir. The liquid surface protectant can be a liquid stain repellent composition or a liquid miticide composition.
[0015] Further according to the invention, a spray applicator for attachment to a portable surface cleaning apparatus having a combination vacuum hose and fluid delivery conduit comprises a unitary body having a suction opening at one end adapted to mount to an open end of the vacuum hose and further having a nozzle pressure conduit that is adapted to fluidly connect to a fluid delivery conduit at one end thereof, a reservoir mounted to the unitary body, a spray nozzle connected to another end of the nozzle pressure conduit, and a fluid reservoir pump in the nozzle pressure conduit and connected to the reservoir for drawing fluid from the reservoir and mixing the reservoir fluid with liquid in the nozzle pressure conduit for spraying a mixture of fluid from the reservoir and fluid from the fluid delivery line onto a surface.
[0016] The unitary body preferably includes a vent connected to the suction opening for venting suction in the vacuum hose to atmosphere and is void of a suction nozzle. In a preferred embodiment, the fluid reservoir pump is an aspirator.
[0017] A body of liquid protectant is within the reservoir. The liquid protectant can be a liquid stain repellent composition or a liquid miticide composition.
[0018] The unitary body and the reservoir have a quick connect mechanism for removably mounting the reservoir to the second liquid dispenser. In a preferred embodiment, the quick connect mechanism includes an open neck on an upper portion of the reservoir and the quick connect is a bayonet connection. Further, a cap is adapted to mount to the open neck of the reservoir when the reservoir is removed from the second liquid dispenser for sealing the reservoir when the reservoir is removed from the second liquid dispenser. Desirably, the neck is threaded and the cap is threaded onto the neck. Further, the reservoir is vented through the threads on the neck.
[0019] The reservoir can take a number of different shapes. In one embodiment, the reservoir has a generally cylindrical sidewall, a bottom wall and a top wall. A portion of the bottom wall extends at an acute angle to the side wall at a position beneath the spray nozzle. Preferably, the acute angle is in the range of about 30 to 60 degrees. In a specific embodiment, the acute angle is about 45 degrees.
[0020] Still further according to the invention, a portable surface cleaning apparatus has a housing, a first tank connected to the housing has a body of a liquid protectant composition therein, a second tank mounted to the housing has a body of water therein, and a spray nozzle in fluid communication with each of the first and second tanks for applying a mixture of the liquid protectant and water to a surface. Preferably, a fluid delivery system has an inlet in fluid communication with each of the first and second tanks and an outlet in fluid communication with the spray nozzle spray nozzle for delivering the mixture of protectant and water to the spray nozzle for spraying a mixture of the liquid protectant and water onto the surface to be treated. In one embodiment of the invention, the fluid delivery system is an aspirator
[0021] In a preferred embodiment, a mixing valve has a pair of inlets in fluid communication with each of the first and second tanks and an outlet in fluid communication with the fluid delivery system. In one embodiment, the mixing valve is selectively adjustable to control the relevant amount of protectant composition in the mixture delivered to the spray nozzle.
[0022] The protectant composition can be a stain repellant, a miticide composition or a mildew repellant, or any mixture thereof.
[0023] In one embodiment, the first tank is connected to the housing through a suction hose. In another embodiment of the invention, the first tank is mounted on the housing. In the latter embodiment, the fluid delivery system includes a pump that is mounted on the housing and supplies water under pressure to the spray nozzle.
[0024] The portable surface cleaning apparatus according to one embodiment of the invention is the type that has a fluid recovery system which includes a suction nozzle mounted to the housing, a recovery tank mounted to the housing, a working air conduit extending between the recovery chamber and the suction nozzle; and a vacuum source in fluid communication with the recovery tank for generating a flow of working air from the nozzle through the working air conduit and through the recovery chamber to thereby draw dirty liquid from the surface to be cleaned through the nozzle and working air conduit and into the recovery tank.
[0025] Still further according to the invention a method of applying a liquid protectant solution to a surface comprises the steps of:
[0026] placing the liquid protectant solution into a dispensing tank in an extraction cleaning machine which includes the dispensing tank, a dispenser for applying a fluid to a surface to be cleaned in fluid communication with the dispensing tank, and wherein the extraction cleaning machine further includes a liquid recovery system for recovering soiled liquid from a surface on which a liquid cleaning solution had been applied; and
[0027] dispensing the liquid protectant solution in the dispensing tank onto the surface through the dispenser as the extraction cleaning machine is moved over the surface.
[0028] Preferably, the liquid protectant solution is applied to a carpeted floor. The liquid protectant solution is preferably a liquid stain, mildew repellent composition, a miticide composition or mixtures thereof.
[0029] In one embodiment, the method of applying a liquid protectant solution to a surface further comprises the step of disabling the liquid recovery system prior to the dispensing step. Preferably, the dispensing step comprises spraying. In one embodiment, the dispensing step includes pumping the liquid protectant solution under pressure to the dispenser.
[0030] In yet another embodiment of the invention, a portable surface cleaning apparatus comprises a base housing adapted for movement along a surface to be cleaned, an upright handle pivotally mounted to the base housing, a liquid dispensing system mounted at least in part to the base housing and a liquid recovery system. The liquid dispensing system includes a liquid dispenser associated with the base housing for applying liquid to a surface to be cleaned, a liquid supply tank with a body of a liquid protectant solution and connected to the liquid dispenser for supplying the liquid protectant solution to the liquid dispenser; and a fluid pump for delivering the liquid protectant solution from the liquid supply tank to the liquid dispenser.
[0031] The liquid recovery system comprises a recovery tank mounted on the base housing and having a liquid recovery chamber for holding recovered liquid, a suction nozzle associated with the base housing and adapted to draw dirty liquid from the surface to be cleaned, a working air conduit extending between the recovery chamber and the suction nozzle and a vacuum source in fluid communication with the recovery chamber for generating a flow of working air from the nozzle through the working air conduit through the recovery chamber to thereby draw dirty liquid from the surface to be cleaned through the nozzle and working air conduit, and into the recovery chamber to thereby recover the dirty liquid from the surface to be cleaned.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] In the drawings:
[0033] [0033]FIG. 1 is a spray applicator according to the invention attached to an upright deep cleaner.
[0034] [0034]FIG. 2 is a perspective view of the spray applicator of FIG. 1.
[0035] [0035]FIG. 3 is an exploded perspective view of the spray applicator of FIGS. 1 - 2 .
[0036] [0036]FIG. 4 is a perspective view of a solution reservoir and spray applicator assembly according to a further embodiment of the invention.
[0037] [0037]FIG. 5 is an exploded perspective view of the solution reservoir and spray applicator assembly of FIG. 4.
[0038] [0038]FIG. 6 is a top view of the solution reservoir of FIGS. 4 - 5 .
[0039] [0039]FIG. 7 is a cross-sectional view taken through line 7 - 7 of FIG. 6.
[0040] [0040]FIG. 8 is a top view of a retainer cap for the solution reservoir of FIGS. 6 - 7 .
[0041] [0041]FIG. 9 is a cross-sectional view taken through line 9 - 9 of FIG. 8.
[0042] [0042]FIG. 10 is a side view of the retainer cap of FIGS. 8 - 9 .
[0043] [0043]FIG. 11 is a top view of the solution reservoir assembly with installed retainer cap of FIGS. 4 - 10 .
[0044] [0044]FIG. 12 is a cross-sectional view taken through line 12 - 12 of FIG. 11.
[0045] [0045]FIG. 13 is an enlarged cross-sectional view of the solution reservoir assembly of FIG. 12 assembled to the nozzle assembly of FIGS. 4 - 5 .
[0046] [0046]FIG. 14 is a bottom view of the nozzle assembly of FIGS. 4 - 5 .
[0047] [0047]FIG. 15 is a cross-sectional view of a lower portion of the nozzle assembly taken through line 15 - 15 of FIG. 14.
[0048] [0048]FIG. 16 is a partial cross-sectional view taken through line 16 - 16 of FIG. 13.
[0049] [0049]FIG. 17 is a perspective view of a solution reservoir assembly according to a third embodiment of the invention.
[0050] [0050]FIG. 18 is a plan view of the solution reservoir of FIG. 17.
[0051] [0051]FIG. 19 is a cross-sectional view taken through line 19 - 19 of FIG. 18.
[0052] [0052]FIG. 20 is the cross-sectional view of FIG. 19 with a seal and siphon tube installed in the reservoir.
[0053] [0053]FIG. 21 is an enlarged cross-sectional view of the seal and siphon tube of FIG. 20.
[0054] [0054]FIG. 22 is a cross-sectional view of a nozzle assembly mounted on the solution reservoir of FIGS. 17 - 21 according to the third embodiment of the invention.
[0055] [0055]FIG. 23 is a schematic view of yet another embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0056] Referring to the drawings and to FIG. 1 in particular, an upright deep cleaner 10 has a floor-traveling head 12 with wheels and a floor suction nozzle (not shown) and an upright handle 14 , pivotally mounted to the floor-traveling head 12 . An above-floor cleaning hose 16 includes vacuum and fluid delivery conduits connected to deep cleaner 10 at one end and to a handle 18 of the hose 16 at another end. Accessory tools can be removably mounted onto the handle for selectively cleaning above-floor surfaces, such as upholstery. The deep cleaner has a fluid delivery system, including a cleaning fluid or clean water tank, a pump and a spray nozzle on the floor-traveling head 12 to spray cleaning fluid onto the floor. The deep cleaner further includes a vacuum source, typically a motor and an impeller to draw suction on the floor nozzle and a recovery tank connected to the nozzle and to the vacuum source, typically between the two, to collect soiled liquid recovered from the floor nozzle. A conversion device or valve selectively connects the above-floor hose 16 with the vacuum source and with the spray pump for above-floor cleaning. Deep cleaners of this nature are well known and are disclosed more completely in U.S. Pat. Nos. 6,041,472 and 6,081,962, which are both incorporated herein by reference.
[0057] According to the invention, a spray applicator 100 is mounted to the handle 18 in lieu of an above-floor cleaning tool for selectively spraying onto a floor or upholstery surface a liquid, such as a protectant, stain repellant, and/or other treatment. The treatment can include oxygen bleaching formulas, or one of numerous known solvent/water based miticides, fungicides or mildewcides, to help achieve a cleaner, more protected and/or lower allergen containing home environment. The material of the spray applicator is preferably a polyethylene or a polypropylene, as these provide maximum chemical compatibility. The spray applicator 100 connects to the fluid delivery system of the deep cleaner 10 to spray a liquid onto the floor when the deep cleaner 10 is converted to the above-floor mode. To this end, the spray applicator has a solution reservoir for the protectant and a venturi or other suction device to mix the protectant with the water from the fluid delivery system and spray the mixture on the floor or other surface to be treated.
[0058] Referring now to FIG. 2, the spray applicator 100 comprises a solution reservoir 110 for holding a liquid solution such as a protectant or stain repellant. A nozzle assembly 120 is assembled to the solution reservoir 110 in a removable fashion, the nozzle assembly 120 being fluidly connected to the solution reservoir 110 . The nozzle assembly 120 includes an opening 126 for mounting of the spray applicator 100 to the above-floor handle 18 of the upright deep cleaner 10 . The nozzle assembly 120 also includes a vent opening 134 which vents the suction in the hose 16 from the vacuum source in the deep cleaner 10 . In some known deep cleaners, the vacuum source is selectively operable independent of other power-operated systems of the deep cleaner, such as a solution pump. A spray applicator 100 for use with such a deep cleaner can omit vent opening 134 . The spray applicator 100 is attached at the opening 126 to the above-floor attachment handle 18 in a removable fashion, a resiliently mounted projection (not shown) of the above-floor attachment handle 18 acting as a detent in a retention aperture 132 of the nozzle assembly 120 . A nozzle opening 128 is at the forward end of the nozzle assembly 120 opposite from the opening 126 for projection of a dispensing nozzle tip 162 therefrom.
[0059] Referring now to FIG. 3, the spray applicator 100 according to the invention is shown in exploded form to more definitively show the details of the invention. Solution reservoir 110 includes a reservoir neck 112 for receiving the nozzle assembly 120 . Solution reservoir 110 is enclosed except for the reservoir neck 112 . The reservoir neck 112 includes a pair lugs 114 projecting outwardly from the surface of the neck 112 .
[0060] The nozzle assembly 120 as shown in FIG. 3 includes an upper housing 130 , a lower housing 140 , a water supply tube 122 , a nozzle supply tube 124 , a venturi 150 and a dispensing nozzle 160 . The lower housing 140 includes a first attachment end 146 corresponding to the attachment opening 126 of the overall nozzle assembly 120 and a second dispensing nozzle end 148 corresponding to the nozzle opening 128 of the nozzle assembly 120 . The lower housing 140 further includes a solution suction tube fitting 144 depending from the lower housing 140 within a sleeve 142 . Sleeve 142 is adapted to connect nozzle assembly 120 to reservoir 110 at reservoir neck 112 , such that when the nozzle assembly 120 is assembled to the solution reservoir 110 , the solution suction tube fitting 144 lies within the reservoir neck 112 and a solution suction tube (not shown) fluidly connected to the solution suction tube fitting 144 reaches to the bottom of the solution reservoir 110 for fluidly connecting the lower housing 140 to solution at the bottom of the solution reservoir 110 . The solution suction tube fitting 144 is further fluidly connected to a venturi-receiving well 145 in the interior of the lower housing 140 . Lower housing 140 further includes a number of alignment bosses 143 for aligning lower housing 140 with upper housing 130 .
[0061] The upper housing 130 of the nozzle assembly 120 includes a first end 136 corresponding to the opening 126 , forming the opening 126 in concert with the first end 146 of the lower housing 140 and a second dispensing nozzle opening end 138 . The dispensing nozzle end 138 in concert with the dispensing nozzle end 148 of the lower housing 140 forms the nozzle opening 128 of the nozzle assembly 120 .
[0062] The venturi 150 includes a water supply tube fitting 154 , a nozzle supply tube fitting 156 and a solution suction fitting 152 . The venturi 150 is inserted in the lower housing 140 so that the solution suction fitting 152 is fluidly and sealingly connected to the solution suction tube fitting 144 and thus the solution within the solution reservoir 110 . The solution suction fitting 152 is inserted in the well 145 and includes an outer resilient surface forming a leak-tight seal in the well 145 . The venturi 150 is supported by a pair of support cradles 147 in the lower housing 140 and secured in place by corresponding projections (not shown) in the upper housing 130 .
[0063] The water supply tube fitting 154 is connected to the water supply tube 122 . The nozzle supply tube 124 is fluidly connected to the nozzle supply tube fitting 156 of the venturi 150 in the lower housing 140 . The nozzle supply tube 124 is further fluidly connected to the nozzle supply tube fitting 164 of the dispensing nozzle 160 . The dispensing nozzle 160 is configured to be fixed in the nozzle end 148 of the lower housing 140 so that the dispensing nozzle tip 162 is directed toward the dispensing nozzle opening 128 of the nozzle assembly 120 .
[0064] The water supply tube 122 , fluidly connected to the water supply tube fitting 154 of the venturi 150 , is further affixed to the lower housing 140 so that an opposite end of the water supply tube 122 is presented at the opening 126 of the nozzle assembly 120 . When the nozzle assembly 120 is attached to the handle 18 of the hose 16 , the water supply tube 122 fluidly and sealingly connects to the fluid delivery conduct of the above-floor cleaning hose 16 . The water supply tube 122 , venturi 150 , nozzle supply tube 124 and dispensing nozzle 160 are further mechanically secured by integral projections within the nozzle assembly 120 upon assembly of the upper housing 130 to the lower housing 140 . The upper and lower housing 130 , 140 are configured and contoured to present a continuous outer surface upon assembly of the nozzle assembly 120 .
[0065] The assembled nozzle assembly 120 , including a solution suction tube (not shown) can then be assembled to the solution reservoir 110 (containing a protectant solution). The lugs 114 cooperate with a ramped groove and slots (see, for example, ramped groove 298 and slot 294 in FIG. 5) on an interior surface of sleeve 142 depending from the nozzle assembly 120 for a bayonet connection. The sleeve 142 is lowered over the reservoir neck 112 with the slots aligning with the lugs 114 , with the nozzle assembly 120 aligned at an angle to the left or right of the longitudinal axis of the solution reservoir 110 . As the nozzle assembly 120 is rotated to be in alignment with the solution reservoir 110 , the ramp on the interior surface of the sleeve 142 draws the nozzle assembly 120 down onto the solution reservoir 110 . The end of each ramp engaging the lugs 114 includes a detent portion for engaging the lugs 114 and resisting rotation of the nozzle assembly 120 out of alignment with the solution reservoir 110 . The assembled spray applicator 100 is further adapted to connect to the above-floor attachment handle 18 of the above-floor cleaning attachment of the deep cleaner 10 . The nozzle assembly 120 can also be attached to the above-floor attachment handle 18 without the solution reservoir, with the solution reservoir 110 being attached thereafter.
[0066] Referring now to FIGS. 4 - 16 , a second embodiment of the spray applicator 200 comprises a solution reservoir assembly 210 and a nozzle assembly 220 . Spray applicator 200 connects to and operates with the upright deep cleaner 10 in the same fashion as the first embodiment of the spray applicator 100 , in that opening 226 and water supply tube 122 are fluidly connected to the above-floor attachment handle 18 of the upright deep cleaner 10 , and are held to the handle 18 by a projection on the handle 18 engaging retention aperture 132 .
[0067] Referring to FIG. 5, the spray applicator 200 comprises the nozzle assembly 220 having upper and lower housings 230 , 240 and further comprising a resilient seal 300 . Upper housing 230 displays on an outer face thereof bosses 238 having an internal function of aligning and securing upper housing 230 and lower housing 240 . Upper housing 230 further includes vent openings 234 for venting suction in the hose 16 from the vacuum source of the cleaner 10 . As in the previous embodiment, when used with a deep cleaner having an independently selectively operable suction source, spray applicator 200 can omit vent opening 234 . The solution reservoir assembly 210 includes a solution reservoir 211 having a reservoir neck 212 , a retainer cap 270 and a siphon tube 290 .
[0068] [0068]FIGS. 6 and 7 disclose solution reservoir 211 further including a key 214 projecting from a rear face of reservoir neck 212 on a longitudinal centerline of solution reservoir 211 . Solution reservoir 211 further comprises an over-rotation projection 216 projecting from an upper surface of solution reservoir 211 and aligned on a longitudinal centerline. A lower portion 217 of front face 219 of reservoir 211 is truncated, so that when reservoir 211 is directed downwardly during use, lower portion 217 presents an effectively flat bottom of reservoir 211 to siphon tube 290 . Reservoir 211 is further configured in plan view to conform to the outline of nozzle assembly 210 (see FIGS. 4, 6 and 14 ).
[0069] Turning now to FIGS. 8 - 10 , the retainer cap 270 includes a central body 272 and a collar 274 attached to an upper portion of the body 272 , forming an annular recess 276 therebetween. The body 272 includes first and second well portions 278 , 280 and a depending neck 282 for receiving siphon tube 290 . Depending neck 282 is fluidly connected to second well 280 through aperture 283 . First well 278 is wider than second well 280 , a shoulder 284 being formed therebetween. Shoulder 284 includes a vent aperture 286 passing therethrough.
[0070] Collar 274 includes on an outer surface 292 a standard thread 288 for receiving a sealing cap (not shown) having a matching thread. The sealing cap is threaded onto the collar 274 and tightened to prevent spillage of the liquid contents in the reservoir 211 during storage and transport, and is removed prior to attachment of reservoir assembly 210 to nozzle assembly 220 . Collar 274 further includes a pair of opposing axial grooves 294 extending from an upper surface 296 of the collar 274 to a partial circumferential groove 298 having a detent 302 . Collar 274 further includes a key slot 304 adjacent to recess 276 .
[0071] Referring now to FIGS. 11 - 12 , retainer cap 270 is joined to siphon tube 290 and inserted over neck 212 of solution reservoir 211 . Retainer cap 270 is bonded to solution reservoir 211 . Retainer cap 270 is installed on solution reservoir 211 in a specific orientation, facilitated by the interaction of key 214 on solution reservoir neck 212 (FIG. 7) and key slot 304 on retainer cap 270 (FIG. 9).
[0072] Referring now to FIGS. 14 - 15 , the lower housing 240 of the nozzle assembly 220 includes a venturi well 245 for receiving the solution suction fitting of a venturi (see FIGS. 3, 13, 16 ) for fluidly and sealingly connecting the venturi 150 to a solution suction conduit 252 . The venturi 150 is further supported by a venturi cradle 254 . Lower housing 240 includes a number of alignment bosses 243 for aligning lower housing 240 with upper housing 230 . Dispensing nozzle end 248 is configured to receive a dispensing nozzle 160 . Solution supply tube groove 222 is configured to receive solution supply cube 122 . The solution suction conduit 252 depends from lower housing 240 . Lower housing 240 further includes a depending skirt 242 forming an annular recess 350 between skirt 242 and solution suction conduit 252 on the lower face of lower housing 240 . Annular recess 350 is configured to receive retainer cap 270 of the solution reservoir assembly 210 , so that the solution suction conduit 252 is received in second well 280 and venturi well 245 is received in first well 278 . Lower housing 240 further comprises a pair of opposing radial projections 352 projecting inwardly from skirt 242 and adapted to be axially received in grooves 294 of retainer cap 270 , such that upon full insertion of retainer cap 270 into annular recess 350 , projections 352 are fully engaged in grooves 294 such that rotation of lower housing 240 with respect to retainer cap 270 will direct projections 352 into circumferential grooves 298 . Lower housing 240 further comprises an over-rotation stop 354 having a face parallel to and offset from a longitudinal centerline of lower housing 240 . Over-rotation stop 354 is positioned to align with over-rotation projection 216 to limit the amount of rotation of the solution reservoir 210 with respect to the nozzle assembly 220 .
[0073] Solution suction conduit 252 includes on an outer surface thereof an annular groove 356 and inner recess portion 358 for receiving a retaining seal 300 on the end of suction conduit 252 . Referring to FIG. 13, seal 300 forms a sealed fluid connection between aperture 283 of retainer cap 270 and solution suction conduit 252 . Siphon tube 290 , received in neck 282 of retainer cap 270 , is therefore in fluid communication with venturi 150 through solution suction conduit 252 and aperture 283 .
[0074] Referring now to FIGS. 13 - 16 , the nozzle assembly 220 is mounted to the solution reservoir assembly 210 by lowering the nozzle assembly 220 over the solution reservoir assembly 210 with the annular recess 350 centered over the retainer cap 270 and the solution suction conduit 252 over the second well 280 of the retainer cap 270 . As the nozzle assembly 220 is lowered onto the solution reservoir assembly 210 , the solution suction conduit 252 with attached seal 300 enters the second well 280 in a sealing fashion. The projections 352 are aligned over the axial grooves 294 until the projections 352 reach the circumferential grooves 298 . A relative rotation of the nozzle assembly 220 with respect to the solution reservoir assembly 210 of approximately 40° will direct the projections 352 into the circumferential grooves 298 past detents 302 until projections 352 reach the end of the circumferential grooves 298 . Nozzle assembly 220 is further prevented from rotating past alignment with the solution reservoir assembly 210 by over-rotation stop 354 abutting over-rotation projection 216 . In the preferred embodiment shown, each of the axial grooves 294 is different in length so that the circumferential grooves 298 are at different distances from the top of retainer cap 270 . Projections 352 are likewise placed at different elevations within annular recess 350 to each align with one of the circumferential grooves 298 , thereby preventing incorrect installation of the solution reservoir assembly 210 onto the nozzle assembly 220 . Nozzle assembly 220 and reservoir assembly 210 are configured so that when assembled they present a continuous exterior surface, as a perimeter skirt 246 depends from lower housing 240 to closely conform to an upper edge of reservoir 211 .
[0075] With the solution reservoir assembly 210 assembled to the nozzle assembly 220 , venturi 150 is fluidly connected to the interior of solution reservoir 211 through siphon tube 290 and suction conduit 252 . A fluid is supplied to venturi intake port 155 from supply tube 122 fluidly connected to supply tube fitting 154 . As the fluid passes through the venturi 150 , suction is generated in suction channel 158 and solution suction conduit 252 , thereby drawing fluid through siphon tube 290 from solution reservoir 211 . The mixture of fluids is expelled from venturi 150 at output port 157 through nozzle supply tube 124 fluidly connected to nozzle supply tube fitting 156 .
[0076] A vent aperture 286 passes through the shoulder defined between first well 278 and second well 280 , fluidly connecting the interior of solution reservoir 211 with first well 278 . First well 278 is further fluidly open to the atmosphere through gaps found between retainer cap 270 and annular recess 350 . The interior of solution reservoir 211 is therefore fluidly connected to the atmosphere, so that a vacuum is not created in solution reservoir 211 as fluid is drawn by siphon 150 . It is further anticipated that a notch can be provided in an upper portion of retainer cap 270 to allow a greater flow of air at atmosphere pressure to the vent aperture 286 to prevent formation of a vacuum inside solution reservoir 211 .
[0077] FIGS. 17 - 22 disclose a third embodiment of the solution spray assembly 400 according to the invention. The solution reservoir assembly 410 comprises a unitary blow-molded solution reservoir 411 having an upper surface 414 and a front face 419 having a truncated lower portion 417 . A reservoir neck 412 projects upwardly from upper surface 414 . Solution reservoir 411 is integrally molded with solution reservoir neck 412 . The exterior of solution reservoir neck 412 is molded to include standard threads 488 for receiving a cap for sealing the reservoir assembly 410 during storage and transport. The exterior of solution reservoir neck 412 is further molded to include axial grooves 494 , circumferential grooves 498 , and detent 502 , analogous to the axial grooves 294 , circumferential grooves 498 and detent 302 as described above with reference to FIGS. 8 - 10 depicting retainer cap 270 . Reservoir neck 412 further comprises an integrally formed insert 472 having an upper annular wall 496 flush with the upper end of neck 412 . Annular wall 496 extends inwardly from neck 412 to a depending proximately cylindrical wall 474 that forms a well 480 with a lower annular wall 476 . Insert 472 includes a vent aperture 486 passing through annular wall 496 to the interior of solution reservoir 411 . Solution reservoir 411 further includes an over-rotation projection 416 projecting upwardly from upper surface 414 along a longitudinal axis of reservoir 411 .
[0078] Referring to FIGS. 18 - 20 , the interior of solution reservoir neck 412 comprises a solution reservoir neck channel 470 . Channel 470 is covered at the upper end of reservoir neck 412 by insert 472 , which, in the preferred embodiment, is integrally molded with reservoir neck 412 . Insert 472 includes an upper annular wall 496 , a depending cylindrical wall 474 , a lower annular wall 476 , and an aperture 478 in lower annular surface 476 . Upper annular surface 496 is configured for alignment with the top of solution reservoir neck 412 , with depending cylindrical wall 474 depending into channel 470 . Depending cylindrical wall 474 and lower annular wall 476 define well 480 , centered in solution reservoir neck 412 . Aperture 478 fluidly connects well 480 with the interior of solution reservoir 411 . Insert 472 further includes a vent aperture 486 in upper annular wall 496 fluidly connecting the interior of solution reservoir 411 to atmosphere.
[0079] Referring now to FIGS. 20 - 21 , a siphon tube 490 has a first end 512 and a second end 514 . Annular seal 500 has a lower surface 506 , an upper surface 508 , and a central passage 504 having a perimeter wall 510 . The first end 512 of siphon tube 490 cooperates with perimeter wall 510 of seal 500 to retain siphon tube 490 within central aperture 504 of seal 500 . The assembly comprising siphon tube 490 and seal 500 is inserted into well 480 , with siphon tube 490 passing through aperture 478 and into reservoir 411 such that second end 514 of siphon tube 490 is arranged proximate truncated lower portion 417 of reservoir 411 . Seal 500 is inserted into well 480 such that lower surface 506 sealingly contacts lower annular wall 476 of well 480 . Preferably, an adhesive secures seal 500 to lower annular wall 476 of well 480 to prevent removal. Aperture 478 is thus sealed, fluidly isolating well 480 from the interior of reservoir 411 except through siphon tube 490 .
[0080] Solution reservoir assembly 410 can now be pre-filled with a solution, a standard cap applied to neck 412 , and the sealed assembly 410 transported to the end user. In a further embodiment of the manufacturing process, the solution reservoir 411 can be pre-filled with a solution prior to the insertion of the siphon tube 490 and seal 500 .
[0081] When the user is ready to employ the solution reservoir assembly 410 , the user removes the standard cap from the reservoir neck 412 and attaches the assembly 410 to a nozzle assembly 420 , as shown in FIG. 22. Lower housing 440 of nozzle assembly 420 includes a skirt portion 446 for matching the outer contour of reservoir 411 , as in the second embodiment. Lower housing 440 further includes depending concentric cylindrical walls 442 , 452 , arranged so that cyclindrical wall 452 is lowered into well 480 as nozzle assembly 420 is assembled onto reservoir assembly 420 . Simultaneously, cylindrical wall 442 surrounds reservoir neck 412 so that reservoir neck 412 enters a cavity 550 defined between walls 442 , 452 . Cylindrical wall 442 includes inwardly directed projections (not shown) for engaging axial and circumferential grooves 494 , 498 of the reservoir neck 412 , as in the second embodiment, to prevent displacement of the nozzle assembly 420 from reservoir neck 412 .
[0082] As nozzle assembly 420 is lowered onto reservoir neck 412 , cylindrical wall 452 descends into well 480 until it abuts upper surface 508 of seal 500 . Venturi 150 is mounted within nozzle assembly 420 so that venturi solution suction fitting 152 depends within a cavity 445 formed by cylindrical wall 452 and is flush with the bottom edge thereof. The venturi solution suction fitting 152 therefore abuts upper surface 508 of seal 500 to form a fluid-tight seal with siphon tube 490 and the solution in the solution reservoir 411 . As the nozzle assembly draws solution from the solution reservoir 411 , the interior of solution reservoir 411 is vented through vent aperture 486 to prevent creation of reduced pressure within solution reservoir 411 . The nozzle assembly also includes openings 422 , 426 for connecting the spray assembly 400 to the deep cleaner 10 . The nozzle assembly otherwise functions substantially as described in the previous embodiments illustrated in FIGS. 1 - 16 .
[0083] The operation of the spray applicator 100 , 200 , 400 in combination with the upright deep cleaner 10 (also known as an extractor) will now be further discussed. The spray applicator 100 , 200 , 400 is attached to the above-floor cleaning hose 16 , so that it is fluidly connected to at least the fluid delivery conduit of the above-floor cleaning hose 16 . If the upright deep cleaner 10 is supplying only water, the reservoir of the spray applicator 100 , 200 , 400 can be filled with a surface treatment for mixing with the supplied water. In an alternative method of use, a clean solution tank on the upright deep cleaner 10 can be filled with a pre-mixed surface treatment and the reservoir of the spray applicator 100 , 200 , 400 need not be used.
[0084] The upright deep cleaner 10 is energized to provide a pressurized flow of water or solution through the above-floor cleaning hose 16 , or specifically, the fluid delivery conduit of the above-floor cleaning hose 16 . The above-floor handle 18 of the upright deep cleaner 10 generally includes a dispensing actuator mechanism for the operator to initiate fluid dispensing at the above-floor cleaning attachment 16 . This actuator can take the form of a spring-biased clamp that is releasable by a trigger-like mechanism on the handle 18 . Therefore, the spray applicator 100 , 200 , 400 according to the invention does not require an additional actuation mechanism in the form of a water supply cutoff.
[0085] Upon actuation of the liquid supply from the deep cleaner 10 , the liquid flowing through the water supply tube 122 and venturi 150 creates a low-pressure region in the venturi 150 . The low-pressure region within the venturi 150 draws the surface treatment into the venturi 150 from the solution reservoir of the spray applicator 100 , 200 , 400 . The surface treatment is then mixed in the venturi valve 150 with the water being supplied through the water supply tube 122 for dispensing through the nozzle supply tube 124 and dispensing nozzle 160 for application to a surface being treated.
[0086] Each of the embodiments of the spray applicator 100 , 200 , 400 disclosed includes an opening for receiving the suction conduit of the above-floor cleaning hose 16 . When attached to an upright deep cleaner 10 having a suction source that is activated whenever the deep cleaner is activated, the spray applicator 100 , 200 , 400 must provide venting for the suction conduit to prevent the suction source from overheating. In the alternative, a further embodiment of a spray applicator (not shown) can connect to the fluid supply conduit without engaging the suction conduit of the above-floor cleaning hose 16 . The spray applicator 100 , 200 , 400 is also adapted to be used with an upright deep cleaner 10 having a suction source operable independently of a solution pump.
[0087] Referring now to FIG. 23, there is shown a schematic representation of a solution delivery system which forms a part of an upright water extraction cleaning machine 30 which is disclosed in more detail in U.S. Pat. No. 6,041,472, which is incorporated herewith in its entirety by reference. FIG. 23 shows only the solution distribution portion of that water extraction cleaning machine although the water extraction cleaning machine 30 has all of the features disclosed in the U.S. Pat. No. 6,041,472.
[0088] The solution distribution system comprises a clean water tank 32 having a neck 34 and a valve 36 which dispenses water from the water tank 32 into a receptacle 38 when the clean water tank 32 is mounted on the extraction cleaning machine 30 in a receptacle 38 . A water line 40 extends from the receptacle 38 to an inlet of a mixing valve 42 . The mixing valve has a knob 44 which adjusts the mixing of components in the mixing valve 42 in a manner disclosed in the U.S. Pat. No. 6,041,472.
[0089] A solution tank 46 has a neck 48 and a valve 50 which releases solution in the solution tank 46 to a receptacle 52 when the solution tank is mounted to the receptacle in the extraction cleaning machine 30 . Solution passes from the receptacle 52 through solution line 54 to an input port to the mixing valve 42 . The knob 44 controls the relative amount of clean water in line 40 mixed with solution in line 54 in the mixing valve 42 . The output from the mixing valve 42 passes through line 56 to a pump 58 and from pump 58 through line 60 , branch line 62 , through valve 64 to spray nozzle 66 which applies the water/solution mixture to a floor surface. The valve 64 is controlled by a trigger (not shown) in the handle of the upright extraction cleaning machine 30 .
[0090] A branch line 68 is connected to a spring-biased valve 70 which has a fitting 72 . The foregoing is a description of the upright water extraction cleaning machine as disclosed in the U.S. Pat. No. 6,041,472. According to the invention, a connector 72 is mounted to the fitting 72 to open the valve 70 . The connector 74 is connected to a spray wand 78 through a tube 76 . The spray wand 78 is adapted to spray the solution onto a carpet 80 .
[0091] According to the invention, the solution tank 46 has a protectant solution therein. The protectant solution can be a stain-resistant composition, such as Scotchgard™ protectant, a mildew-resistant composition or can alternatively be a miticide solution. The protectant solution is mixed with clean water in the mixing valve 42 and pumped through pump 58 through the valve 70 , through line 76 and to the spray wand 78 . Alternatively, the protectant solution can be mixed with water and placed directly in the clean water tank 72 and passed through the mixing valve which is set to close off the input port from solution line 54 . The mixture of water and protectant can then pass undiluted through line 56 , pump 58 , line 60 , line 68 , through valve 70 and to the spray wand 78 . In an alternate embodiment, a liquid miticide composition can be added to the solution tank 46 and mixed with water and protectant in the clean water tank 32 by means of the mixing valve 42 and passed to the spray wand 78 for spraying on the carpet.
[0092] While the invention has been specifically described in connection with certain specific embodiments thereof, it is to be understood that this is by way of illustration and not of limitation. Reasonable variation and modification are possible within the scope of the foregoing description and drawings without departing from the spirit of the invention. | A hand-held nozzle is attached to the end of a vacuum and fluid delivery hose of an upright deep cleaner. The nozzle includes a reservoir to contain a solution to be applied to a surface. When a solution delivery system of the deep cleaner is pressurized, water from the upright cleaner clean water tank is routed through the hose to the handheld nozzle. The water is routed through a venturi valve connected to the reservoir, which draws the solution to the valve to mix with the water stream. The resultant mixture flows from the hand-held nozzle for application to a surface being treated. One embodiment of the solution reservoir includes a retainer cap bonded to the reservoir and utilizing a bayonet-type mounting arrangement for mounting the reservoir to a nozzle assembly. | 8 |
BACKGROUND OF THE INVENTION
This invention relates to a vertical blind of the type in which vanes are suspended from a blind head and are capable of traversing the head and rotational movement to control the amount of light passing through the blind.
Vertical blinds are known wherein individual vanes are suspended by carriages traversing a blind head. The carriages in such a blind are linked together by slidable clips that limit the distance between the carriages. A variety of means for rotating the vanes to control the passage of light through the blind are known. Debs, Canadian Patent 1,153,686 and Klenz, U.S. Pat. No. 2,869,636 disclose vertical blinds wherein the vanes are rotated by means of a centrally-disposed rotatable tilt rod, rotation of which effects rotation of the individual vanes. In Klenz, this rotation is effected by way of cooperating edge gears and in Debs said rotation is effected by means of co-operating bevel gears. These gear means have the disadvantage of bulkiness, difficulty of manufacture, and with respect to edge gears, rapid wear and imprecision of fit. Debs discloses in addition a decorative valence clip attaching to rails in the blind head by means of a spring clip that must be fitted with a screwdriver or other tool. It is also known to link the individual vane carriages by means of clips that are fixedly attached at one end thereof to a vane carriage. Said attachment gives rise to the attendant disadvantage of requiring two separate carriage types, mirror images of each other, where it is desired to construct a vertical blind whose vanes are capable of opening from the middle. In addition, replacement of such a clip necessitates replacement of the entire carriage connected thereto.
SUMMARY OF THE INVENTION
The present invention consists of an arrangement for supporting a plurality of vanes of a vertical blind including a novel gear means for effecting rotation of the vanes, consisting of a centrally-disposed rotatable tilt rod, rotation of which effects rotation of a plurality of face gears, each disposed within a slidable vane carrier. Rotation of the face gears effect rotation of corresponding spur gears fixedly mounted to individual vane holders, the teeth of which spur gears are oriented perpendicular to the teeth of said face gears. Another feature of the invention consists of a decorative valence clip adapted to be mounted on a blind head by means of a mounting element of substantially circular shape adapted to be engaged by rails mounted on the blind head and engaged thereby by a cam action. Another aspect of the invention consists of fully-removable flexible clips that serve as slidable spacers for the vane carriages and that may include stop means adapted to allow the user to adjust the spacing between the carriages, and wherein said carriages include means for engaging the stop means. According to another feature of the invention the blind head has a pair of oppositely disposed grooves oriented along the longitudinal axis of the blind head, as well as a pair of oppositely disposed rails parallel to said grooves, the rails being adapted to engage co-operating grooves in a second blind head so as to form a rigid unit comprising linked blind heads for purposes of shipping.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front elevational view of a vertical blind according to the present invention showing the blind in a fully closed position;
FIG. 2 is an exploded view, in perspective, of the blind head;
FIG. 3 is a front view of a vane carrier forming part of the blind head;
FIG. 4 is a cross-sectional side view of a vane carrier;
FIG. 5 is an exploded view, in perspective, of a vane carrier;
FIG. 6 is a perspective view of a vane carrier including the pull cord and spacer strips of the blind head;
FIG. 7 is a perspective view of a portion of the blind head showing a decorative valence and valence clips for securing the valence to the blind head;
FIG. 8 is a frontal view of a valence clip;
FIG. 9 is a cross-sectional view of the blind head with a decorative valence clip in place;
FIG. 10 is a perspective view of a decorative valence clip according to the present invention.
FIG. 11 is a cut-away side view of an end piece of the blind head illustrating the tilt rod turning mechanism;
FIG. 12 is a front view of the end piece shown in FIG. 11.
FIG. 13 is a sectional view of two blind heads connected for storage or transportation.
FIG. 14 is an elevational view of a portion of a vane carrier embodying a further aspect of the present invention.
FIG. 15 is a perspective view of a spacer strip embodying another aspect of the present invention.
FIG. 16 is a perspective view of a vane carrier embodying this further aspect.
FIG. 17 is a top view of a vane carrier and spacer strip embodying this further aspect.
FIG. 18 is a partial cross sectional view of a vane carrier and spacer strips embodying a further aspect of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings in detail, FIG. 1 shows a vertical blind according to the invention in a fully closed position. The blind can be installed inside a window frame or attached to a ceiling or wall. The vertical blind comprises a head 7 adapted to be attached to a window frame, ceiling or wall by brackets, not shown, holders 6 adapted to attach the vanes 2 to carriers within the head, a pull cord 3 to which is attached a counterweight 4, cord 3 being adapted to pull the vanes 2 open and shut; and a pull chain 5 that rotates the individual vanes about vertical axes.
Referring to FIG. 2, the blind head 7 is generally box shaped, with a top wall 33, rear wall 34 and front wall 35. The bottom side of the box is open. Extending outwardly from wall 35, and preferably integral therewith, are parallel, spaced apart, longitudinally extending rails 12. The rails 12 are provided with opposed grooves 100, as best seen in FIG. 9, in which may be secured a decorative strip of metal, plastic, or other suitable material. The decorative strip (not shown) would have a width such that its opposite edges would be secured in the grooves 100 and it would preferably have about the same length as the blind head. The rear wall 34 is also provided with grooved rails 12, which may be identical to the grooved rails 12 on the front wall 35 and may be used for the same purpose.
The grooved rails 12 may also be used to secure valence clips 66 as shown in FIG. 7 and as will be further described below. Each of the vane carriers 9 includes a clip-type holder 10 having resilient arms 102 (see also FIGS. 3 and 4) adapted to grip and hold an end of a vane and has a pair of grooves 74 for engagement with support rails 13 extending inwardly from the front and back walls 35, 34 of head. Slotted clips 8 are connected between adjacent vane carriers 9 which, as aforesaid, are adapted to move slidably within head 7, and to engage the individual vanes by means of holders 10. Clips 8 connect the adjacent vane carriers 9 to each other and limit their travel relative to each other. Clips 8 also provide a means for sequentially sliding all the vane carriers within the head from an open blind position adjacent one end to completely cover most of an underlying window in a closed blind position. Tilt rod 14 is disposed between sides 34 and 35 of head 7 and attaches rotatably to end units 6 and 36. It passes through holes in the vane carriers and, when rotated, causes the holders 10 (and attached vanes) to be "tilted", i.e. rotated about vertical axes to adjust their orientation and hence vary the amount of light entering the window. Tilt rod 14 preferably includes axially extending strengthening ribs. Tilt rod 14 also contains an axially extending groove (wider spacing between two ribs) adapted to engage drive gears in the vane carriers.
Blind head 7 is fitted at one end with an end unit 6 including a gear mechanism 19 for turning tilt rod 14. Opposing end unit 36 contains a sleeve 32 for the free rotation therein of tilt rod 14 and a pulley 29 for engagement of a pull cord 3. End units 6 and 36 may be constructed of plastic or other suitable material and can be snapped into head 7 by squeezing together arms 27 and pushing the units into the open ends of head 7 until pins 28, located on opposite sides of each arm 28, snap into corresponding holes 37 in the walls of head 7.
Referring to FIGS. 11, and 12, end unit 6 has a drive pulley 24 that is adapted to be rotated by chain or cord 5 (FIG. 2). Pully 24 is mounted rotatably on pin 17 and is adapted to engage pinion 19 by means of gear teeth 58. Pinion 19 is coaxially mounted on a shaft 59 carrying a worm gear 57. Worm gear 57 and its associated pinion 19 are removably attached to end unit 6 by means of removable attachment of the ends of shaft 59 within clips 68 and 68'. Worm gear 57 engages with gear 60, which consists of a hollow sleeve encircled by gear teeth adapted for engagement with worm gear 57. Hollow opening 61 within said sleeve includes key member 62 adapted to engage tilt rod 14 for rotatable movement thereof. Additional key members and corresponding slots in tilt rod 14 may be included for additional stability. Pegs 26 extending inwardly into head 7 from end units 6 and 36 serve to keep vane carriers 9 spaced sufficiently from the end of head 7 to prevent the vanes from hitting an abutting wall or window frame. Movable parts including pulley 24 and shaft 59 with gears 19 and 57 are all readily removable for replacement when worn. These parts can be assembled or disassembled without special tools or skills by simply cliping them into their respective slots or engaging them on their respective pegs.
Movement of carriages 9 slidably within head 7 is effected by an endless cord 3 disposed within head 7 and extending through openings in end unit 6 for operation by the user. Cord 3 passes through apertures 38 (FIG. 3) disposed on opposite sides of vane carriers 9. Equal spacing of apertures 38 from tilt rod 14 ensures a minimum of torsional forces affecting carrier movement during opening or closing of the blind. Pulleys 29 and 22 are mounted for rotation on pins 31, 21, respectively in end units 36 and 6 to ensure smooth movement of cord 3.
Referring to FIGS. 3, 4 and 5, each vane carrier 9 is comprised of an upper wall 43 and two side walls 44 adapted to fit within head 7. Internal webs 45 connect walls 44 with a central gear housing 46. Gear housing 46 supports face gear 39 which is adapted to be rotated by tilt rod 14. Face gear 39 includes a circular central opening 40 with a key element 42 adapted to engage a corresponding slot in tilt rod 14. Additional key elements and corresponding slots may be included for additional stability. Face gear 39 is held within housing 46 by holder 49 and spur gear 11. Vane holder 10 which carries pinion 11, is detachably attached to carrier 9 by means of the generally C-shaped clip 47, which is integral with webs 45 and housing 46. Clip 47 releasably engages shank 48 of vane holder 10 having spaced apart legs 102. Spur gear 11 formed at the top end of shank 48 is adapted to engage face gear 39, rotation of which accordingly rotates the vane holder 10 and any attached vane 2. Apertures 38 receive cord 3 as it passes along the length of blind head 7. Carrier 9 includes a t-shaped clip 41 extending above upper wall 43, which clip is adapted to releasably engage sliding clips 8.
Referring to FIG. 6, it will be seen that two sliding clips 8 and 8 1 are attached to t-shaped clip 41. Clip 8 1 overlies clip 8. The end of the lower clip 8 is retained within a shallow indentation 50 in carriage 9. Movement of the lower clip 8 to the right relative to carriage 9, as viewed in FIG. 6, is blocked by wall 51; movement to the left is prevented by t-clip 41. The upper connecting clip 8 1 is free to slide to the left relative to carrier 9 by virtue of longitudinally extending slot 52. The two side legs of clip 8 1 (and clip 8 which is identical thereto) which define slot 52 pass on opposite sides of the support post 110 of t-clips 41 (FIG. 3). As can be seen in FIG. 6, the clip 8 1 has end portions 112 defining end limits for slot 52. Slots 52 allow carriages 9 to abut each other or move apart as far as the length of the slot 52. Connecting clip 8, formed of resilient material such as plastic, can be installed or removed from t-shaped clip 41 by a simple twisting motion to bring the axis of slot 52 in line with the longitudinal axis of t-shaped clip 41. This feature allows easy assembly and repair of the device and provides for the construction of a vertical blind that requires only a single type of carriage and connecting clip, whether the blind opens from the side or from the middle.
The vane carriers 9 are linked by connecting clips 8. Cord 3 is used to effect slidable movement of the carriers 9 sequentially. Where it is desired that the blind opens from one side, the free ends of cord 3 are each tied in a knot, the two knots being disposed on opposite sides of an aperture 38 of end carrier 9 remote from end unit 6. Of course the knots are made large enough that they cannot pass through aperture 38. Where it is desired that the blinds open from the middle, the free ends of cord 3 are tied in a knot as above at one of the middle carriers. The cord is fastened by small metal crimps to an adjacent carrier at the opposite side of the knots. The two carriers thus define the point at which the vanes open. The opposing motions of the two sides of the cable loop cause the vanes on either side of this point to slide in opposing directions.
An additional embodiment is illustrated by FIG. 18. This embodiment consists of a vane carrier 123 as described above with a shallow indentation 121 disposed therein comprising a shallow groove traversing the width of the carrier. Lower clip 122 includes pegs 124 depending downward therefrom on respective sides thereof. Clip 122 is releasably attached to vane carrier 123 by means of pegs 124 which fit within corresponding holes 125 in the vane carrier 123. Clip 126 overlies clip 122. It will be seen that clip 122 may be attached to carrier 123 so as to extend out from the reverse side thereof, by attachment of clip 122 to holes 125' in carrier 123, thereby enabling identical carriers to be used on both sides of a center opening blind. It will be further seen that the present embodiment may comprise a clip and carrier combination as described above wherein two sets of pegs are disposed on the carrier and a set of corresponding holes is disposed within the clip.
Referring to FIGS. 7, 8, 9 and 10, the decorative valence and clip therefore are shown attached to one side of blind head 7. As mentioned above, the user can attach decorative valences to either or both sides of blind head 7. The decorative valence consists of a decorative strip 53, which, can in fact, be a vane identical to those comprising the body of the blind. The decorative strip 53 is retained in grooves 115, 116 in the holder portion 56 of valence clip 54. A number of valence clips 54, as desired, may be attached to the rails 12 extending along the side walls 34 and 35 of the blind head as described above. In the preferred embodiment, the valence clip 54 is molded of rigid plastic. Valence clip 54 includes an essentially circular mounting element 55 having a flat side 120, as best seen in FIG. 8 adapted to engage rails 12. In other words it is in the form of a truncated disc. Dimension "y" is slightly less than the spacing between rails 12 whereas diameter "x" is slightly greater. Engagement of clip 54 is effected by placing mounting element 55 between rails 12 with flat side 120 parallel to rails 12, rotating valence clip 56 90° to its final position and thereby attaching the mounting element firmly behind rails 12 as best seen in FIG. 9. Mounting element 55 comprises an outer portion 67 that is larger than the inner portion 68. This extension creates a rim that flexes slightly inward when the valence clip is turned to the vertical position, thus allowing the clip to be held rigidly in the vertical position as required to hold the decorative valence 53.
Referring to FIG. 13, the blind heads 7 are adapted to be disassembled and linked together to facilitate transportation and storage. Grooves 70 are adapted to be engaged by rails 71 of a second disassembled blind head, which can in turn receive the rails 60 of a third disassembled blind head. Blind heads thus assembled can be readily transported with reduced risk of damage.
In a further embodiment of the present invention illustrated in FIG. 14, face gear 39 includes an inner sleeve 65 rotatable within the circular opening of face gear 39. Inner sleeve 65 is frictionally engaged by face gear 39, and is adapted to allow adjustment to the tilt angle of individual vanes.
In another embodiment of the present invention, illustrated in FIGS. 15 to 17, connecting clips 72 include three or more pairs of pegs 73, all of which are oriented in the same direction, perpendicular to the plane of the connecting clip. Pegs 62 are adapted to engage stop 63 in the corresponding carrier 64.
In use, a blind head may contain a plurality of units, consisting of a carrier and its associated connecting clip, of this alternative embodiment. Such a blind head will have two or more vanes spaced closer together than the standard-sized clip would otherwise allow, thereby allowing a greater range of blind sizes to be constructed.
In the preferred embodiment, all the component parts of the vertical blind can be easily assembled or disassembled without special tools or skills. In addition, the individual vane holders can be removed from the blind head without further disassembly thereof.
In operation, the vanes can be pulled open or shut and rotated about their lengthwise axes by means of cord 3 and chain 5 respectively. In the embodiment disclosed herein, both chain and cable are disposed at the same end of the blind for convenience of operation. If desired, however, these two elements can be located at opposite ends of the blind head.
Although preferred embodiments of the invention have been described and disclosed herein, it is to be remembered that various alterations can be made thereto without departing from the true spirit and scope of the invention as defined by the appended claims. | A vertical blind with an arrangement for supporting a plurality of vanes comprised of an elongate blind head with a plurality of slidable vane carriers disposed therein, each adapted to rotate an individual vane about its vertical axis. Rotational movement of the vanes is effected by providing the blind head with a central rotatable tilt rod that engages a series of face gears disposed within each of the carriers. Each carrier also includes a pinion gear engaged by the face gear and mounted to a vane holder adapted to rotate within a clip provided on the carrier. The vertical blind may also include a plurality of slinding clips linking the carriers, the clips being readily removable from the carriers. The clips may include fastening arrangements which enable adjustment of the spacing between the carriers so as to provide a vertical blind capable of fitting within different dimensions. The vertical blind may also include a plurality of valence clips for attachment of a decorative valence. These valence clips releasably mount to rails attached to the blind head by mounting plates that attach behind an extending portion of the rails. The vertical blind may also include a head with an arrangement of interlocking grooves and rails that allows a plurality of heads to be releasably attached together in order to form a single rigid transportable unit. | 4 |
This application is a continuation application of Ser. No. 07/680,758, filed Apr. 5, 1991, abandoned.
BACKGROUND OF THE INVENTION
This invention relates to an automatic atmosphere conditioner which is capable of adjusting the atmospheric condition in a room. This invention discloses a method and a device to generate and control indoor atmosphere. The so-called atmosphere is not only the weather phenomenon or the air condition, but, more particularly, the environment of physiological and psychological states for the human. For example, we say, "the business negotiation goes under a harmonious atmosphere."
It is generally known that the human body is easily affected by various environments and generates various emotions in response to the environments. People can be in high spirits, or absent-minded or relaxed in response to environmental factors (characteristics) such as temperature (air temperature, wall temperature), humidity, air pressure, wind (air flow) speed, oxygen content, carbon-dioxide content, static electrical ion, sound, odor, light, magnetic field, etc. In consequence, those factors can be regulated to a specified status to make people concentrate on study, work or feel relaxed, drowsy, etc.
The human body, which can be considered as a heat producer is usually exposed to an environment in which the temperature is lower than that of the body, and dissipates heat by continuous radiation, conduction, convection, breath and sweat. When the temperature difference between body and environment is large and the heat generation rate of the body is lower than its heat dissipation rate, people will feel cold; when the temperature difference between the body and its environment reaches a certain degree where the heat generation rate and the heat dissipation rate are in balance, people will feel comfortable; and when temperature difference mentioned is small or the temperature of the environment is higher than that of the body, people will feel irritable because the dissipated heat is not exhausted quickly enough. When people feel cold, the skin pores will naturally shrink to reduce sweat and lower the heat dissipation rate; on the other hand, intense exercise increases body heat, which can be dissipated by profuse sweat; that is, the human body has a self-modulated function of dissipating heat rate to sustain the body temperature. However, in order to easily modulate body heat rate and make people feel comfortable, appropriate air humidity and temperature are two of the most important factors. The indoor wall temperature (includes the temperature of all side walls, the ceiling and the floor) also has an influence, however, since the wall temperature will not be adjusted quickly, it will not be herein considered as a controlled factor of this invention to affect the thermal balance of body. What human the body feels is the so called effective temperature is referred to the dry bulb temperature with 100% relative humidity in still air. With a certain relation between humidity and temperature, people will feel the same effective temperature. For example, with an effective temperature 22° C., the dry bulb temperature of may vary increasingly from 23.6° C. to 26.6° C. if the relative humidity varies decreasingly from 70% to 30% (as shown in the appended FIG. 4-a). The relation of temperature and humidity, which can be controlled to provide a constant heat dissipation rate for the human body to obtain a thermal balance condition, can be explored to generate a favorable regulating response by stimulating skin or other sensory organs (such as shrinkage of skin pores, tension or relaxation of skin) and inspire spirits.
In the past, when people feel sleepy due to environment or excessive fatigue, the ways to keep awake are to wash the face with cold water, stimulate the skin mechanically or get up to exercise. However, these often fail to provide the desired effect due to laziness which is the human nature, short lasting or unavailable conditions.
Furthermore, a traditional air conditioning system is at most able to control temperature or humidity to a certain preset reading (the real control result is the controlled variables that varies slightly around the desired value.) Because of this, the human body will constantly dissipate heat by almost fixedly expanded skin pores (sweat gland). People will feel numb or drowsy as the skin pores keep the same expansion for a long time; and once they leave the controlled environment, to become subject to outdoors' quite different temperature and humidity, they are easily attacked by heat-stroke or catch a cold.
Air pressure and air content also have a great effect on the human body. When the pressure drops or the oxygen content lessens, people will feel sick because of difficulty in breathing. On the other hand, if oxygen is in adequate supply or the indoor pressure is increased adequately, people will breathe smoothly, keep alert and improve their working efficiency. The concentration of carbon dioxide in the natural world is 0.03%˜0.05%. If the indoor carbon dioxide concentration is up to 0.2%˜0.5%, people will feel bored and drowsy; if the concentration exceeds 0.5%, it will cause physiological malfunctions or even lead to death. The conventional air conditioner can not control air pressure or air content. The air exchange design of a conventional air conditioner only opens a valve between the indoor and outdoor environments and can not control the amount and direction of incoming or outgoing air. Therefore, it can not effectively expel the dirty indoor air or induce clean and fresh outdoor air.
Air flow speed also affects the environment. When it is like a gentle breeze, people will feel cozy (comfortable) and drowsy; when it becomes a gusty wind, people will feel nervous and uneasy because it seems that an imminent catastrophe is just ahead.
The human skin not only perceives cold/hot feeling and sense of touch, the body hairs can also be made to stand on end. People may shudder with fear (fright) or feel excitement when the hair is affected by a static electric field or attachment of ions. Besides, a magnetic field may affect a human's body or spirit, but the effect has not been fully understood yet.
The odor also affects one's mood; for example, an offensive smell may cause nausea. People in an environment which simulates a garden or forest will feel pleasant and refreshed.
Noise may also bother one's feelings. For example, soft music makes people feel leisurely, classic music makes people feel elegant, and rock and roll make people eager to dance. Apparently, sound and music affect people's mood quite a bit.
Moreover, indoor light may also affect people's physiological reaction; such as obscure light makes people feel drowsy; soft light and color make people feel romantic; bright light and color make people feel sober; and abundant light makes people concentrate on work or study.
However, there is no atmosphere control system in the present market that can wholly modulate/control the above mentioned atmospheric factors. The indoor environment consequently can not be adjusted to meet the users' respective requirements.
SUMMARY OF THE INVENTION
Based on those reasons, the present invention first provides an atmosphere control system that controls of indoor atmospheric factors so as to generate different atmospheric effects to make people feel cozy, refreshed, able to concentrate, sleepy, uneasy, or even frightened.
The invention secondly provides an atmosphere control system that adjusts the physiological reaction of human body based on the control and adjustment (manipulation) of environmental factors including temperature, humidity, wind speed, etc. and effect on adequate heat dissipation rate of the human body to meet the principles of thermal balance.
The invention thirdly provides an atmosphere control system that modulates/controls the difference between the indoor and outdoor temperature indoor humidity and the indoor wind speed (air flow). It can help persons avoid heat-stroke or catching cold while entering or leaving a room.
The invention fourthly provides an atmosphere control system that controls the indoor air pressure and purifies the air content by drawing in or expelling an adequate amount of air.
The invention fifthly provides an atmosphere control system that provides a specified atmosphere based on an integrated control of such factors as indoor sound, light, odor, static electricity and magnetic field, etc.
The invention sixthly provides an atmosphere control system that generates various odors or kills germs or insects by injecting or expelling various odors, disinfectant or insecticide automatically.
To achieve the above mentioned objects, the indoor atmosphere control system according to the invention comprises sensors to respectively detect/measure indoor/outdoor air temperature, humidity, air pressure, oxygen content, carbon dioxide content, air cleanliness and static electric charge and sensors to respectively detect/measure indoor wall temperature, sound volume and light. Signals from the sensors are sent to a microcomputer through a signal transfer interface. The microcomputer is informed of user requirements through a user interface, calculates a sensed value provided by each sensor, compares the values with prestored data, and outputs adequate control signals through an control interface to actuate a series of actuators which modulate indoor temperature, humidity, air pressure, oxygen content, carbon dioxide content, airflow speed, static electric charge, magnetic field, sound, odor, light, etc. Different indoor atmosphere effects will be generated thereby.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood and further objects and advantages thereof will become more apparent from the ensuing detailed description of a preferred embodiment taken in conjunction with the drawings.
FIG. 1 is a block diagram illustrating the basic construction of the invention.
FIG. 2 is a table listing an example of the modulation of different atmosphere control factors of the invention.
FIG. 3 is a schematic diagram of an embodiment of the invention.
FIG. 4a and 4b are respectively a graph and a pair of curves, showing the indoor temperature and humidity to be controlled based on the physiological functioning of the human body.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows the basic construction of the present invention including: a group of individual sensing devices 1 which consists of sensors for detecting and measuring the values of the environmental characteristics, namely indoor air temperature (sensor 11), outdoor air temperature (sensor 12), humidity (sensor 13), air pressure (sensor 14), indoor oxygen content (sensor 15), outdoor oxygen content (sensor 16) carbon dioxide content (sensor 17), static electric charge (sensor 18), indoor sound volume (sensor 19), brightness of light (sensor 20), number of persons in a room (sensor 21), movement of a human body (sensor 22) and indoor wall temperature (sensor 23). All the output signals of the sensor will be fetched by a microcomputer 3 through a signal transfer interface 2. The requirement input by the user's interface 31 will be received by the microcomputer 3 which will measure/detect the sensed values of the sensing devices 1 based on a prestored program and prestored data in a memory unit 35 and output control signals through an actuation interface 4 to actuate a series of actuation devices 5 which contain various actuators to modulate indoor air temperature, indoor wall temperature (actuator 51), humidity, air pressure, oxygen content, carbon dioxide content, wind speed, (air flow speeds) static electric charge (ion-concentration) magnetic field, sound, odor, brightness (actuator 52), color (actuator 53), etc. The output through microcomputer 3 can also be displayed by a display 39.
The program and data prestored in the memory unit 35 include the ranges of values of various control factors corresponding to various atmosphere requirements for effecting the way people feel with respect to such things as comfort, freshness, concentration, sleep, disturbance, or fear). For example, as shown in FIG. 2, when the indoor temperature is controlled between 22°˜26° C. in the summer or 20°˜24° C. in the winter, the humidity is relatively modulated between 70˜35%, (this provides an effective temperature on the human body of around 19°˜22° C.) and soft music is provided in the meantime, then as a matter of course, a comfortable atmosphere is generated. On the contrary, it will make people feel disturbed if the indoor temperature is kept around 25°˜32° C., humidity around 70˜85%, the air pressure is lowered a little bit and more noise is made. These various items and their ranges can be modified, based on the results of different experiments, to meet the requirements of different persons, jobs, time and locations. Moreover, the monitoring program and data in the memory unit 35 also include switching procedures; for example, while executing a "sleep atmosphere", it can start from "drowsy atmosphere", and then smoothly change to the next adequate modes and finally switch to "awakened atmosphere" to make people wake up.
The modulation of environmental characteristics including temperature, humidity, wind speed, etc. in this invention can be implemented based on the operation of a conventional air conditioner. As an embodiment of this invention shown in FIG. 3, the air conditioner is basically constructed to include a refrigerant (R-22) compressor R, an indoor heat exchanger E1 and its fan F1 and motor M1; an outdoor heat exchanger E2 and its fan F2 and motor M2; a 4-way directional value S, an expansion valve D and unshown refrigerant circulated in the tubes. The 4-way valve S controls the flow directions of high temperature high pressure refrigerant output from compressor R; that is, when the valve S is in the position S1, the refrigerant compressed by compressor R and output through tube L1 will be connected to tube L2 and reach outdoor heat exchanger E2 to be condensed (the outdoor air exhaust A2 is warm air). Then, through expansion valve D, the refrigerant reaches heat exchanger E1 to be evaporated (the indoor air supply A1 is cold air); after that, the low temperature, low pressure refrigerant is connected to tube L4 and drawn back to compressor R. This is the circulation for cooling. On the contrary, when the valve S is in the position S2, tube L1 will be connected to tube L3, tube L2 will be connected to tube L4, and this forms the circulation path for heating. The generation of indoor warm air can also use an unshown electric heating apparatus. The aforesaid construction is of the prior art. This invention further has a humidifier 54 and/or an unshown dehumidifier by which, the indoor humidity can be modulated by mixing original indoor air with the dehumidified indoor air coming through the indoor heat exchanger E1). This invention can also fully control the indoor/outdoor air pressure differential and air intake/exhaust (by exchanging or mixing indoor and outdoor air) based on an inlet valve (flap) V1, an outlet valve (flap) V2 and piping between them. The valve V1 enables the indoor air supply A1 to come from indoor air return A11, outdoor air intake A12, or a mixture of those two in any desired ratio. The valve V2 enables the outdoor air exhaust A2 to come from indoor air A21, outdoor air A22, or a mixture of those two in any desired ratio, and, in consequence, the indoor air pressure can be controlled and the indoor air can be purified (each opening of inlet/outlet air has a filter F to filter out the dirt in the air). Since the air intake/exhaust of indoor/outdoor fans F1 and F2 are controlled by the rotation of motors M1 and M2 respectively, and the humidifier 54 and an oxygen supply device 55 can be actuated, the indoor temperature, humidity, air pressure, air content, etc., can be modulated to any condition conforming to outdoor conditions. For example, when some characteristics of the outdoor air condition (temperature, humidity, oxygen content, carbon dioxide content, etc.) are closer to the required values than those in the present indoor condition, the valve V1 will open appropriately to intake outdoor air A12 by means of fan F1, or the valve V2 will open appropriately at the same time to discharge indoor air A21 by means of fan F2, to give the effect of exchanging air or mixing air. When the indoor air pressure is to be increased, the valve V1 for outdoor air A12 is increasingly opened and the valve V2 for indoor air A21 is shut down gradually, or the motor M1 is sped up at the same time, and the outdoor air will be drawn indoors. On the contrary, when the indoor air is to be exhausted or the indoor air pressure is to be lowered, the valve V2 for indoor air A21 is increasingly opened and the valve V1 for outdoor air A12 is shut down gradually, or the motor M2 sped up at the same time, and the indoor air will be forced outdoors. The temperature of indoor air supply A1 is decided by the temperature of mixed indoor and outdoor air A11, A12 and the heat-exchange rate of indoor heat exchanger E1. The heat-exchange rate is decided by the speed of motor M1 and the opening rate of expansion valve D. The humidity of air supply A1 is decided by the humidity of the mixed indoor and outdoor air A11, A12, and the humidifying rate of humidifier 54 or dehumidifying rate of the indoor heat exchanger E1. Besides, an oxygen supply device 55 can provide the required content of oxygen, and an odor/disinfectant/insecticide supply device 56 can provide a spray or liquid A13 of specified odor or drug, which will be mixed with indoor air supply A1 and generate a specified atmosphere. The microcomputer 3 (as shown in FIG. 1) receives the output signals of the above mentioned indoor and outdoor sensing devices 1 and, based on the requirement, sends out appropriate control signals to the actuation interface 4 to perform the required actuations; for example, the human body sensor 20 of the sensing devices 1 can scan and detect the number of indoor persons and automatically control the amount of air exchange. (The amount of air exchange therefore is in proportion to the number of indoor persons.) The actuators further include an ion generator 57 which provides required static electric charge for the indoor atmosphere, a magnetic field regulator 58 which regulates the intensity and direction of indoor magnetic field, a sound regulator 59, and light intensity (brightness) regulator 52 and color regulator 53 can generate atmosphere of specified sound, light intensity and color, respectively. The humidifier 54 and odor/disinfectant/insecticide supply device 56 can utilize a moisturized net, a nozzle or an ultrasonic humidifier. The oxygen supply device 55 can utilize an air storage tank or an oxygen generator from electrolysis. The static electric charge generator 57 can function with high voltage ionized air to generate negative ions. The magnetic regulator 58 can function with an electromagnet. The sound, light and other regulators can utilize any existing technologies which are not necessary to be described further.
The above mentioned air exchange and odor/disinfectant/insecticide supply device 56 can shoot out and remove odor automatically to generate a different atmosphere or obtain the effect of killing germs or insects; that is, the supply device 56 can generate a required odor based on the time setting and preset amount of odor; or when nobody is home, the disinfectant or the insecticide will be discharged to the room air and hold for a preset period of time until the indoor germs or insects are all dead; the device will then operate indoor/outdoor air exchange automatically, and the indoor air will be kept refreshing when someone returns.
This invention regulates and controls the indoor temperature and humidity based on the principles of sweat dissipation rate and respiration (thermal balance) of the human body: that is, the body temperature, wall temperature, air temperature, humidity and wind speed are regulated with time-variation control to fit the physiological functioning of the human body such as the shrinkage/openness of the skin pores and tense/relaxation of the skin. This invention will modulate differences of indoor temperature, humidity and the air flow based on those outdoor variant factors. In consequence, the human can avoid heat-stroke or catching cold while moving between an outdoor environment and an indoor environment. The characteristics of these controls, with respect to the relationship of domains of temperature and humidity, will be further described with reference to FIG. 4.
FIG. 4-a shows the relationship among dry bulb temperature (D.B.; horizontal axis), wet bulb temperature (W.B.; vertical axis), relative humidity (R.H.; oblique line directed to the upper right) and effective temperature (E.T. curved line directed to the lower right) felt by the human body when the room air flow speed is in the range of 5-8 m/min. Through statistical evaluation, the domain of temperature and humidity in which people feel comfortable is obtained as shown in the figure within the zone surrounded by lines of constant of effective temperature (t 1 and t 2 ) and constant relative humidity (h 1 and h 2 ). (It is of normal distribution. The central value of the comfort zone represents the favorite conditions for most people.) The zone may vary with the seasonal dress, racial custom, etc. This invention is to control temperature, humidity and air flow speed relatively and provides the desired so-called effective temperature felt by the human body. (As shown in FIG. 4-b, there are sinusoidal curves of the same effective temperature tx which may be obtained by increasing temperature C1 with decreasing humidity C2 or decreasing temperature C1 with increasing humidity C2, i.e., the curves are out of phase with each other). This will keep a proper heat dissipation rate for the human body and makes people feel comfortable. Consequently, temperature and humidity can be regulated anytime to stimulate the skin pores of the human body to inspire spirit. On the other hand, as the conventional air conditioner fixes the value of temperature and humidity, the sweat gland and skin of the human body keeps expanding or shrinking all the time. People will feel numb and drowsy, and once they leave the room, they are not able to adapt themselves to the sharp impact of outdoor temperature and humidity and may because to suffer heat-stroke or catch cold. As a result, this invention will gradually adjust the air flow speed that blows on the user while he moves into or out of the room; that is, to help people adapt themselves to the environment, the invention will reduce indoor/outdoor temperature and humidity differences. (The movement of a person into and out of the room can be detected by a sensor of movement of a human body.) The above mentioned modulation of indoor temperature and humidity, does not mean to provided a fixed effective temperature, but to keep the indoor temperature and humidity in a range (such as the shown comfort zone) conforming to the outdoor situation. The skin pores and skin should be stimulated in accordance with the reaction rate of the human body; for example, the period of each sinusoidal variation can be around 10˜60 minutes--practically, the amplitude and frequency can be adjusted based on various requirements.
The invented atmosphere control system can modulate environmental factors to set a specified atmosphere through integrated control of indoor temperature, humidity, air pressure, air content, sound, light, odor, static electricity, magnetic field, etc. It can be applied to many places. For example, in a room for study, the classroom or the working place, it can be controlled to promote concentration so as to give encouragement and improvement of working efficiency; in a restaurant, it can provide a refreshing atmosphere to give an appetite; in an amusement place, it can provide a refreshing or specified atmosphere to make people feel joyful; in a vehicle or boat, it can provide a concentrative or refreshing atmosphere to avoid drowsiness or carsickness; in the bedroom, it can provide a drowsy or comfortable atmosphere to make people feel sleepy or promote romantic feelings; in an interrogation room, it can provide different atmosphere to make a suspect confess without covering up; and in a conference or meeting room, it can provide a refreshing or harmonious atmosphere to enhance the negotiating effect and reduce conflict.
While preferred embodiments of the invention have been described in detail, it is particularly understood that the invention in not limited thereto or thereby, and it is evident to those skilled in the art that various changes and modifications may be made therein without departing from the invention. | An interior atmosphere control system contains a group of sensors to detect/measure indoor and outdoor air temperature, humidity, air pressure, oxygen content, carbon-dioxide content, static electric charge, indoor wall temperature, sound and light. These measured results, through a signal transfer interface, are sent to a microcomputer which also accepts a user's command as input data through a user's interface. The microcomputer, based on a monitor/control program and data prestored in its memory unit, the sensed values, and the user's command, will then execute the necessary calculation, comparison and decision, and output adequate time variant control signals, through an output interface, to actuate a series of actuators to adjust the indoor temperature, humidity, air pressure, oxygen content, carbon-dioxide content, wind speed, static electric charge, magnetic field, sound, odor, and light which will generate different atmospheric modes, for example, to make people feel comfortable, refreshed, awakened, energetic, sleepy, uneasy, or even frightened. Above all, these feelings are promoted on the basis of the natural balance of human body, such as heat release and perspiration, by adjusting, the room temperature, humidity, wind speed and other factors. | 5 |
BACKGROUND OF THE INVENTION
This invention relates to interferometry, and more particularly to an interferometry apparatus and method utilizing a phase-conjugate mirror.
Optical interferometers are known which make use of the interference phenomenon known as the "speckle effect"--the speckled pattern of laser light when reflected from a rough surface. One prior-art speckle interferometer takes the form of a Michelson-type instrument in which the mirror of one arm is replaced by a scattering surface. Provided that the coherence of the laser light is sufficiently high, speckles are formed by interference between light from the reference-beam arm and the light scattered retro-reflectively from the rough surface. Translating the scattering surface in the direction of the incident light causes each speckle to vary in brightness cyclically, from light to dark, independently from its neighbor, in a similar way that points on the equivalent Michelson mirror would appear to fluctuate in brightness as interference fringes sweep across it when the mirror is moved. The visual speckle interferometer can thus be used for detecting movement, but not for measuring the displacement that has taken place. Further, since a plane wave with uniform amplitude serves as the reference for the speckle wave, the plane wave cannot be matched to the random variation of amplitude over the speckle pattern. Thus, the visibility (or contrast) of the interference pattern cannot be made the same throughout the field.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to study the deformation of the surface of an object under stress.
It is a further object of the present invention to measure the relative magnitude of the displacements from the original position at different points on the surface of an object under stress.
It is yet another object of the present invention to provide an improved interferometry apparatus utilizing the speckle effect wherein the contrast of the interference pattern is the same everywhere in the field.
The objects of the present invention are achieved by an interferometer design using optical phase conjugation to yield fringes of good contrast and standard interferometric sensitivity. The speckle interferometer includes a beam splitter, a mirror in the object beam arm, a phase-conjugate mirror in the reference beam arm, a converging lens and a photographic film. Laser light scattered retro-reflectively from a rough surface under investigation and passed through a collimating lens illuminates the interferometer. Fringes occur upon sandwiching a pair of exposures of the interference pattern made before and after deformation of the rough surface. No additional spatial filtering step is necessary. The relative magnitude of the displacements from the original position at different points of the surface can be determined from the position of the fringes.
The foregoing as well as other objects, features and advantages of the present invention will become more apparent from the following detailed description when taken in conjunction with the appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of the apparatus of the invention.
FIG. 2 is a flow chart of the steps in carrying out the method of the invention.
FIG. 3 is a schematic illustration of the n th order band.
FIG. 4 is a schematic illustration of the m th and (m+1) th order bands.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, the apparatus for studying the deformation of the surface of an object under stress, such as a loaded cantilever, includes a monochromatic laser source 11 which illuminates the surface 13 through a beam splitter 15. The surface 13 is assumed to be optically rough and therefore produces a speckle pattern when it is illuminated by the laser light. The light scattered by the points x, y of surface 13 is reflected by the beam splitter 15 into an imaging lens 17 to provide the input beam to the interferometer device. A beam splitter 19 divides the input beam into a reference beam 21 and an object beam 23. The reference beam 21 forms an image of surface 13 in the plane of a phase-conjugate mirror 25 and is reflected back to the beam splitter 19 by the phase-conjugate mirror 25 which reverses the phase of the beam. Suitable phase-conjugate mirrors are well-known in the art, and are discussed, for example, in the article "Phase Conjugate Optics" by J. AuYeung et. al., Optics News (Spring 1979) pp. 13-17. The object beam 23 forms an image of surface 13 in a plane normal to the beam and intersecting a plane mirror 27 tilted at an angle β with respect to the plane and is reflected back to the beam splitter 19 by the mirror 27. The two beams 21 and 23 recombine at the beam splitter 19 and are photographed on film 29 through a converging lens 31 which forms an image of mirrors 25 and 27 at unit magnification onto film 29. At the photographic film 29, the speckle patterns produced by the two beams are allowed to interfere to produce a resultant image, the points x, y of which correspond to the points of surface 13. The recorded intensity in the film plane is given by:
I(x,y)=|u.sub.o +u.sub.r |.sup.2 (1)
where u o and u r are the speckle patterns produced by the object beam 23 and the reference beam 21 respectively and are given by:
u.sub.o =|A(x,y)|exp{i[θ(x,y)+αx]}(2)
u.sub.r =|A(x,y)|exp{i[-θ(x,y)]} (3)
In these expressions, A(x,y) and θ(x,y) are functions of position in the film plane. A(x,y) represents the square root of the intensity of the speckle patterns. The phase of u o is θ(x,y)+αx; the phase of u r is -θ(x,y). It is assumed that the optical path lengths in the interferometer device are matched except for the path difference introduced by the tilt of the mirror 27 which gives rise to a phase difference in the expression for u o of (2π/λ) (2β)x.tbd.αx for small β. The minus sign before θ(x,y) in the expression for u r is due to the operation of the phase-conjugate mirror 25.
Substituting equations (2) and (3) into equation (1), the following expression is obtained for the recorded intensity:
1=2|A(x,y)|.sup.2 {1+cos [2θ(x,y)+αx]}(4)
Note that in equation (4), the intensity of the speckle pattern |A(x,y)| 2 is multiplied by an expression which has a modulation index of unity but depends on the phase of the light. Thus, in applications where one wants to measure the phase variation across the beam of the electric field vector of a light wave of varying amplitude such as a speckle pattern, the phase conjugate of the wave may be used instead of a plane reference wave in the production of interference patterns for the measurement of the phase variation. Since the amplitudes of the light wave and its conjugate are the same, the visibility of the interference pattern is automatically one. This would not be the case if a plane wave with uniform amplitude were used as the reference for the speckle pattern. Because of the random variation of amplitude over the speckle pattern, the plane wave could not be matched to it. Thus, interference with the phase conjugate wave provides a relatively simple way to measure the phase of a speckle pattern.
Referring to the flow chart shown in FIG. 2, the method of studying the deformation of the surface 13 of the object under stress includes a first step 33 of recording the resultant speckle pattern before the relevant deformation of the surface 13. The recorded intensity at the film 29 is then given by:
I.sub.1 =2|A|.sup.2 [1+cos (2θ.sub.i +α.sub.i x)] (5)
where the functional dependence of A and θ on x and y has been suppressed. The expression (2θ i +α i x) is the phase factor with the surface 13 in its initial state (i) and the plane mirror 27 tilted at an angle β i .
Next, the second step 35 is performed hereby the plane mirror 27 is tilted at an angle β d different from β i .
In the third step 37, the resultant speckle pattern is recorded after the relevant deformation of the surface 13. The recorded intensity at the film 29 is then given by:
I.sub.d =2|A|.sup.2 [1+cos (2θ+α.sub.d x)](6)
where the expression (2θ+α d x) is the phase factor with the surface 13 in its deformed state (d) and the plane mirror 27 tilted at the angle β d . The change in θ arises from the altered optical path length due to the deformation of the surface 13. The change in αx arises from the altered optical path length due to rotation of the plane mirror 27.
The fourth step 39 comprises superposing a set of transparencies of the two recordings in front of a source of light to observe the transmitted light intensity. The transmitted light intensity I T is proportional to the product of the separate intensities, i.e., I T =kI i ·I d , where k is the proportionality constant. Substituting equations (5) and (6), I T is given by: ##EQU1## where
B=θ.sub.i +θ.sub.d +1/2(α.sub.i +α.sub.d)x (9)
C=θ.sub.i -θ.sub.d +1/2(α.sub.i -α.sub.d)x (10)
Since the speckles are very small, a local spatial average can be performed on each term in equation (8). In an ensemble average sense, cos 2 B averages to 1/2 assuming a uniform distribution of the phases θ i and θ d between π and -π, while the cross-term 2 cos B cos C averages to zero. Then equation (8) becomes ##EQU2## The transmitted light intensity is a speckle pattern having a series of bands, alternately light and dark, appearing on it. The visibility (or contrast) of the bands is the same throughout the field, namely, the visibility ##EQU3## independent of position. Further, it will be appreciated that the factor of 2 in front of (θ i -θ d ) in the argument of the cosine doubles the sensitivity of the band pattern to a change in phase.
Each of the bright bands corresponds to a locus of points in the film plane for which the cosine term in equation (12) is a maximum. Referring to FIG. 3, the n th order bright band (viz., the one for which the argument of the cosine term equals n 2π) is schematically illustrated as the curve OPQ in the film plane. Point P on the band satisfies the relation
2δθ(x.sub.n (y.sub.n),y.sub.n)+δα·x.sub.n (y.sub.n)=n2π (13)
where δθ=θ-θ d , δα=α i -α d and the subscript n refers to the n th order band. The dependence of δθ on x and y and the dependence of x on y along the band contour has been made explicit. δθ is a function whose amplitude varies in accordance with the normal displacements Δ at different parts of the surface 13 from the original position. δθ is zero at points in the film plane corresponding to points of the surface 13 where the displacement Δ is zero; a value for δθ of 2π radians corresponds to a normal displacement Δ at the surface 13 of one-half the wavelength of the laser light. Equation (13) can be rewritten in terms of Δ as follows:
4Δ(x.sub.n (y.sub.n),y.sub.n)+2δβ·x.sub.n (y.sub.n)=nλ (14)
Here, δα has been replaced by δα=2π/λ(2δβ) where δβ.tbd.β i -β d ; and δθ has been replaced by 2π/λ(2Δ), where the factor of 2 arises because the displacement is seen in reflection.
Point 0 on the band satisfies the relation
4Δ(x.sub.n (0),0)+2δβ·x.sub.n (0)=nλ(15)
Subtracting equation (15) from equation (14), the normal displacement of a point on the surface 13 corresponding to point P on the band relative to the normal displacement of a point on the surface 13 corresponding to point O on the band, is given by:
Δ(x.sub.n (y.sub.n),y.sub.n)-Δ(x.sub.n (0),0)=-(1/2)δβ[x.sub.n (y.sub.n)-x.sub.n (0)] (16)
In the fifth step 41, the difference in tilt angles, δβ is determined. From a region of the film plane where the bands are straight, corresponding to no displacement of the surface 13, i.e., Δ(x,y)=0, one can find the value of δβ from the distance between two bands. Referring to FIG. 4, the m th and (m+1)th order bands for such a region of the film plane are illustrated as lines O'P'Q' and O"P"Q". From equation (14), point P on the m th order band satisfies the relation:
2δβ·x.sub.m =mλ (17)
where x m is the x coordinate of the m th order band. Point P" on the (m+1)th order band satisfies the relation
2δβ·x.sub.m+1 =(m+1)λ (18)
where x m+1 is the x coordinate of the (m+1)th order band. Subtracting equation (18) from equation (17), the difference in tilt angles is given by: ##EQU4## If the bands are not straight anywhere in the field, δβ can in principle be found from a pair of preliminary recordings taken before the surface 13 is deformed.
The sixth step 43 is performed to determine the normal displacement of a point on the surface 13 corresponding to point P on the band, relative to the normal displacement of a point on the surface 13 corresponding to point O on the band from equation (16) by multiplying δβ/2 by the distance between the two points O and P along the x direction.
Obviously, many 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. | A speckle interferometer including a beam splitter, a mirror in the object beam arm, a phase-conjugate mirror in the reference beam arm, a converging lens and a photographic film. Laser light scattered retro-reflectively from a rough surface under investigation and passed through an imaging lens illuminates the interferometer. Fringes occur upon sandwiching a pair of exposures of the interference pattern made before and after deformation of the rough surface. The relative magnitude of the displacements from the original position at different points of the surface can be determined from the position of the fringes. | 6 |
TECHNICAL FIELD
[0001] The present invention is in the field of network interface controllers and, in particular, is related to a switching network interface controller that is configurable for use in a variety of different networking configurations.
BACKGROUND
[0002] There are a variety of networking applications for which, conventionally, various specialized hardware is available. It would be desirable to have a network interface controller solution that is flexibly configured for use in these various applications.
SUMMARY
[0003] A reconfigurable network interface controller circuit is provided for various networking operations. The circuit is scalable, and provides for redundancy in such networking operations.
[0004] The network interface controller includes a plurality of scatter gather circuits connectable to a host via a bus. A packet buffer is configured for communication with the scatter gather circuits. A plurality of access circuits are configured to access external network connections. An optional forwarding engine is selectable to generate routing information corresponding to data received via the access circuits and to provide the routing information to the packet buffer.
BRIEF DESCRIPTION OF FIGURES
[0005] FIG. 1 schematically illustrates an example multipurpose network interface controller circuit.
[0006] FIGS. 2A and 2B illustrate the FIG. 1 circuit in a network interface controller configuration.
[0007] FIGS. 3A and 3B illustrate the FIG. 1 circuit in a switch configuration.
[0008] FIG. 4 illustrate the FIG. 1 circuit in a hybrid configuration.
[0009] FIG. 5 illustrates the FIG. 1 circuit in a network processor configuration.
DETAILED DESCRIPTION
[0010] Turning now to FIG. 1 , an example configurable network interface controller circuit 100 is described. In some embodiments, the FIG. 1 network interface controller circuit is implemented in an application specific integrated circuit (ASIC), such as a field-programmable gate array (FPGA). In one example, the circuit is configurable to implement applications such as:
Multi-Channel Ethernet NIC Controller L2/L3 Ethernet Switch System Controller SOHO Router Network Processor
[0016] The various blocks of the FIG. 1 example are now summarized.
PCI-X Core (PX 102 )
[0017] This is a standard quad-function PCI-X core, with 4 identical Master interfaces to SGE's 104 a through 104 d , and one target interface TI 106 . This block in addition houses the Serial ROM interface logic.
Forwarding Engine (FE 108 )
[0018] This module makes routing decisions based on a vector that it receives from the MAC 110 or the SGE 104 modules. The results of the routing decisions are conveyed to the packet buffer PB 112 via the Route Vector bus 114 .
MAC (Mn 110 )
[0019] This is a 10/100/1000 MAC module. In one example, this module includes VLAN Tag and Station Address logic (which are normally disabled in the presence of a Forwarding Engine).
Packet Buffer (PB 112 )
[0020] This is a general purpose queuing engine core switch fabric, that allows management of arbitrary sized packets. A particular example of the PB 112 is described in U.S. Provisional Patent Application No. 60/283,285 filed Apr. 11, 2001 and incorporated herein by reference in its entirety.
Memory Controller (MC 116 )
[0021] This is a generic memory controller that can control, for example, SSRAM memories 118 .
Lookup Memory Controller (LM 120 )
[0022] This is an SSRAM only memory controller that provides a path to an external memory 122 (e.g., for a forwarding table and/or instruction memory).
CPU Interface (CI 124 )
[0023] This module is a collection of muxes and base addresses that switches various busses and manages the address map of an on-board processor 125 . This module decodes the PL-Bus regions and generates chip selects to various modules.
Scatter Gather Engine (SGn 104 )
[0024] This module handles the Scatter Gather operation in a NIC mode, provides a path to the packet buffer 112 from PX 102 in the Switch mode, and provides a path to the packet buffer 112 from the CPU 125 in the System Controller mode.
Wake up, On Now Logic (ON 124 )
[0025] This module implements power management functions.
Narrow Checksum (NC 126 )
[0026] This module calculates the TCP/IP/HTTP/UDP checksums and provides the result to the packet buffer 112 upon completion of a frame arriving from the MAC 110 .
Wide Checksum (WC)
[0027] This module calculates the TCP/IP/HTTP/UDP checksums and provides the result to the packet buffer PB 112 upon the completion of a frame as it is arriving from the PCI bus 101 via the PX 102 .
[0028] In all modes of the operation (NIC, Switch, etc.), the data is pushed to the SGE 104 by the packet buffer 112 and to the packet buffer 112 by the SGE 104 .
[0029] Clocking within the FIG. 1 example is now described. Specifically, the components of the FIG. 1 example operate in three different clock domains. These clock domains include the core clock domain (which includes the on-board CPU 125 and the memory interfaces (LM 120 and MEMC 116 ); the MAC 110 clock domains (which, in some examples, includes several actual clock regimes); and the PCI-X 101 clock domain. In some examples, no phase lock loops are employed.
[0030] In cases where the FIG. 1 example is an FPGA as opposed to an ASIC, the FPGA clocking is the same as the ASIC clocking except for the MAC clock section. Further, some IO delay lines are inherent to the FPGA IO pads, and are explicitly built in the ASIC configuration.
[0031] In reset, all clock domains are synchronized to the PCI-X clock domain. The PHY chips can be reset individually. In addition, soft reset resources allow the local resetting of the FIG. 1 circuitry by the local processor 125 under control of local firmware.
[0032] In accordance with one example, the FIG. 1 circuit is operable in at least four different modes by reconfiguring the operation of the various modules. Each of these four modes of operation are now described. In the description, the Receive and Transmit nomenclatures are always with reference to the wire (i.e., receive from the wire and transmit to the wire) unless otherwise specified.
[0033] The NIC operation mode is now discussed with reference to FIGS. 2A and 2B . In general, the NIC operation mode is a relatively simple mode of operation of the FIG. 1 example circuit. A simplified block diagram of the NIC mode is represented in FIGS. 2A and 2B . In this mode, the on-chip processor 124 , the forwarding engine 108 and the associated secondary memory 122 are not used (and, in fact, need not be even populated in the ASIC/FPGA) and, thus, are shown as “grayed out” in FIG. 2B . Various NIC operation mode operations are now described.
NIC Receive
[0034] In the NIC receive operation, data is received from the MAC 110 , through the N-Bus, and stored in the PB 112 using, for example, the paging hardware of the packet buffer PB 112 . The Rvec is determined in one example using a stub model, for the packet buffer PB 112 to determine from which queue it should push the data out. Once the data is completely stored in the appropriate queues of the packet buffer, it is then pushed to the appropriate Scatter Gather Engine 104 . While transiting on the N-Bus, checksums are calculated on the incoming data from the MAC 110 by the NCS 126 and stored into the packet buffer PB 112 . In one example, the checksum 110 storage is accomplished by strobing a payload (including the checksum) to the packet buffer PB 112 following the last element of the data being stored. The stored data is then transferred into the host memory from the PB 112 by the Scatter Gather Engine 104 (via the PX 102 and the PCI-X 101 ). In this mode of operation, the packet buffer PB 112 does not perform any broadcast or multicast operations and, as such, looks substantially like an external FIFO per channel.
NIC Transmit
[0035] In the NIC transmit mode, data is gathered from the host memory (via the PCI-X 101 and PX 102 ) by the appropriate SGE 104 and pushed to the packet buffer PB 112 . While transiting the W-Bus, checksums are calculated on the data by the WCS 128 and delivered to the packet buffer PB 112 by strobing a payload (including the checksum) into the packet buffer PB 112 following storage of the last element of data. Once the packet is completely stored in the packet buffer PB 112 , the packet is forwarded onto the N-Bus to the appropriate MAC 110 .
NIC Fail Over
[0036] The link fail over is handled entirely in software.
NIC Multicast and Broadcast
[0037] These features are handled entirely in software.
NIC Flow Control
[0038] In the receive direction, once the descriptor queue of a TAP in the packet buffer PB 112 goes over a high water mark, a signal is asserted to the corresponding MAC 110 to cause the MAC 110 to generate flow control signals to its link partner. Depending on the MAC configuration, the traffic resumes either after a fixed amount of time or after the queue in the packet buffer PB 112 has dropped below the low water mark, the occurrence of which is also transmitted to the MAC 110 . In the transmit direction, once the queue for the TAP, in the packet buffer, becomes full and data “backs up” into an SGE 104 , the transmit function of the packet buffer 112 simply stops. In both directions, once the SGE 104 runs out of resources such as free lists or transmit buffers, traffic simply stops.
[0039] The switch operation mode is now described with reference to FIGS. 3A and 3B . In the switch configuration, the FIG. 1 example circuit employs the local forwarding engine FE 108 to make routing decisions for each packet in each direction. A given packet is examined once upon arrival to the source node and once upon exiting the destination node. The local processor CPU 125 is used for management purposes.
[0040] The switch backplane may be thought of as a virtual backplane. That is, the switch backplane includes multiple virtual channels on top of the PCI bus 101 . Each virtual channel includes a scatter gather engine SGE 104 performing DMA writes to a reserved range of addresses in the host memory. That range of address is programmed into the receiving node's PCI base address register. Therefore, each pairing of the base address value programmed into a node's PCI base address register and the value programmed into another node's scatter gather engine 104 receive DMA address register configures a virtual channel. Each node is effectively a quad-function PCI device and hence has 4 memory base addresses, thus allowing 4 virtual full-duplex links to a node. This virtual back-plane of one example uses three base addresses, leaving the fourth one, corresponding to the node number of the device, unused.
[0041] In the switch mode of operation, the Scatter Gather Engine 104 does not do any linked list operations and simply pushes the data as consecutive data elements to the PCI 101 . The data arriving from the PCI 101 is received on the PCI's target interface 106 which is then muxed to the appropriate SGE 104 . The receive DMA address restarts at the base address at the start of every packet and the lower bits of the address are used to determine the length of a packet. Upper bits of the address, while still within the address range, are used to transfer additional information to the receiver. Each base address range is 256 Mbytes (28 bits). The largest packet that the switch handles is 64 Kbytes (16 bits), allowing 12 bits of payload (e.g., sequence numbers, etc.). Each node can be conceptualized, in some instances, as either a Source Node or a Destination Node. Source Node is the node where a packet initially comes into the system (via the Source Port), and Destination Node is the node through which the packet leaves the switch.
[0042] As data arrives from the MAC 110 , the MAC 110 generates a long vector comprised of the DA, SA, VLAN, QoS fields of the incoming packet. This vector is then submitted to the forwarding engine FE 108 . The packet then bypasses the checksum 126 and wake up 124 blocks before being written into the packet buffer PB 112 . By this time, the forwarding engine 108 computes a routing vector 114 which is provided to the packet buffer 112 for the packet buffer 112 to place on the appropriate destination queue. In one example, a limit of 16 clocks is placed on the forwarding engine 108 for the lookup time per minimum sized packet (64 bytes). During this time, the forwarding engine 108 completes two lookups and a conditional learn operation.
[0043] Once the packet is fully stored in the packet buffer 112 , it is pushed out one of the W-Buses to the SGE module 104 . The SGE module 104 —which operates as a pass through in the switch configuration—simply pushes the data out to the node that was indicated by the forwarding engine 108 . The packet eventually appears on the target interface (T-Bus) of the destination node's PCI bus 101 . Once the data arrives from the PCI bus 101 on the T-Bus of a destination node, the target interface 106 of the destination node routes the packet to the packet buffer 112 of the destination node. Meanwhile, the forwarding engine 108 computes a routing vector 114 for the packet and submits the routing vector 114 to the packet buffer 112 .
[0044] Switch multicast and broadcast are handled in the forwarding engine 108 . In case of a multicast or broadcast packet, the result is flagged to the packet buffer via a routing vector with multiple bits set.
[0045] In one example, the packet buffer 112 and the forwarding engine 108 can each pipeline two messages, to absorb the latency of the forwarding engine 108 . The SGE 104 use flow control PIO writes to its link partner SGE to control the rate of the switch backplane traffic.
[0046] The hybrid mode of operation is now described with reference to FIG. 4 . In the hybrid mode of operation, the FIG. 1 example circuit acts as a 4-port switch combined with a up to a 4-port NIC. The FIG. 1 example circuit can “own” up to eight MAC addresses, four for its switched ports and up to four for its embedded NIC ports. The hybrid mode of operation is handled in the forwarding engine 108 . Although the architecture allows for more, in some examples, the forwarding engine 108 has only enough bandwidth for a single port NIC. Power management logic is used in the hybrid mode to detect “magic packets,” etc. and to generate appropriate power management events.
[0047] Once a packet arrives from the MAC 110 (“receive event”), the received packet is submitted to the forwarding engine 108 . The received packet is concurrently written into the packet buffer 112 followed by checksum information. The Rvec 114 from the forwarding engine 108 indicates if the packet should be switched out of a port (via one of the N-Buses) or delivered to the host (via a W-Bus). Data received into the SGE 104 from the packet buffer 112 is typically delivered to the host.
[0048] For transmit, the data to be transmitted is normally gathered from the host memory into the packet buffer 112 . However, the SGE 104 also submits the packet to the forwarding engine 108 . The forwarding engine 108 in turn indicates to the packet buffer 112 onto which queue of the packet buffer 112 to place the packet. The checksums are calculated in this path. Although unlikely, one NIC port may wish to send a packet to another NIC port.
[0049] In the “system controller” mode of operation, any external host adapter is leveraged for interfacing to other protocols (e.g., SCSI, USB, SONET, USB, etc.). The NIC appear as a PC to the external host adapters. As such, the FIG. 1 example circuit provides a high bandwidth path to the local packet buffer 112 . Further, a section of the packet buffer 112 is allocated as simple passive memory for use by the external host adapters. The external host adapters use this area to scatter and gather their traffic into the local memory 118 . The processor 125 can access this data via the C-Bus path. Thus, in this mode, the FIG. 1 circuit is functioning as a system controller integrated with a processor.
[0050] In the network processor mode of operation, represented in FIG. 5 , firmware effectively “visits” every packet at the wire speed while relieving some of the overhead of packet processing. All the packet processing may then be performed via the firmware. This mode of operation can be thought of as a superset of the system controller mode of operation. In this mode of operation, it is generally desired to transfer data from one MAC 110 to another MAC 110 or to an external host adapter once the processor has had an opportunity to read and write portions of the packet. Once the packet is modified, the FIG. 1 circuit recomputes the checksums. In this configuration, the SGE modules 104 are used by the local processor 125 to access the packets via the queuing system. Thus, the head of the W-Bus FIFO in the SGE module 104 is read by the processor 125 via C-Bus and it is written to via C-Bus.
[0051] The network processor receive operation is now described. As packets arrive from the MAC 110 , the checksums for the packets are computed ( 126 ) and the packets are written into the packet buffer 112 . The packet buffer 112 operates in the NIC mode in this case. That is, there is effectively a hard path between N-Bus- 0 to W-Bus- 0 , etc. The received data is pushed out to the respective SGE 104 via the respective W-Bus. Once the SGE 104 senses the presence of new data, it interrupts the local processor 125 . The processor 125 then performs burst reads of SGE's 104 W-Bus receive FIFO into the data cache of the processor 125 . Once the processor 125 has examined and rewritten the data, the processor 125 scatters the data into a portion of the packet buffer 112 not used for queuing. The data is then gathered by the external host adapter and consumed by the host adapter. Optionally, the data from the local processor 125 is burst written into the SGE's 104 transmit W-Bus FIFO. The checksum is computed ( 128 ) on this data by the FIG. 1 example circuit before being written into the packet buffer 112 . Further, the routing vector from the first element of data is retrieved and submitted to forwarding engine 108 for multiplexing onto the Rvec bus 114 so as to place the packet on the desired N-Bus or W-Bus queue in the PB 112 .
[0052] The network processor transmit operation is now described. When a packet is to be transmitted to the wire by an external host adapter, the packet is first scattered into the local memory 118 by the external host adapter. The packet is then read by the local processor 125 via the C-Bus. Once the local processor 125 has examined and rewritten the packet, the local processor 125 burst writes the packets along with a routing vector 114 into the transmit W-Bus queue of the SGE 104 . The checksum on the packet is then computed ( 128 ) and the packet is forwarded to the N-Bus or W-Bus. If the packet to be transmitted is coming from another port of the same instantiation of the FIG. 1 circuit, the packet is first received by the local processor 125 and is then burst written into the SGE 104 along with a routing vector. | A network interface controller includes a plurality of scatter gather circuits ( 104 a - 104 d ) connectable to a host via a bus ( 101 ). A packet buffer ( 112 ) is configured for communication with the scatter gather circuits ( 104 a - 104 d ). A plurality of access circuits ( 110 a - 110 d ) are configured to access external network connections. An optional forwarding engine ( 108 ) is selectable to generate routing information corresponding to data received via the access circuits ( 110 a - 110 d ) and to provide the routing information to the packet buffer ( 112 ). | 7 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] U.S. Provisional Application No. 60/760,100 for this invention was filed on Jan. 19, 2006 for which the inventor claims domestic priority.
BACKGROUND OF THE INVENTION
[0002] The present invention is broadly directed to a locking assembly for fastening two fluid-transmitting conduits together and, more particularly, to an improved fluid coupling assembly for providing a compression sealed joint that can maintain its preload characteristics without the utilization of lock wire or other externally applied devices or chemical compositions.
[0003] Numerous devices have been utilized to retain the mechanical coupling of fluid-transmitting conduits during use. As is well known, application of stress, vibration, movement, etc. to a coupled connection can cause a loosening and release of a desired seating torque between a pair of fluid-transmitting conduits which have been coupled together. A typical method of connecting two adjacent fluid-transmitting conduits is to utilize a threaded coupling, wherein each respective end of the conduit is attached to a component of the coupling apparatus. The seals of the coupling apparatus are thereafter preloaded by making up the threaded connection between the components of the coupling. However, it is known that various phenomena such as vibration, flexing, or other cyclical or dynamic loading can cause such couplings to work loose potentially resulting in fluid release. Numerous methods and apparatus have been utilized to inhibit the loosening of the coupling after it has been preloaded, including lockwire and adhesive materials have been used to prevent the loosening of the coupling.
[0004] The loosening of the connection can be a particular problem for pneumatic and hydraulic connectors, which are not only subjected to external vibrations and stresses, but also subjected to internal pressure stresses from the fluid that is being conducted through the sealed joint. In past practice in the aircraft industry, a substantial number of fluid coupling joints have consisted of compression fittings secured together with threaded connections, where a nut is lock wired to a mating connecting component in such a manner that the nut cannot turn with respect to the fitting to ensure against loss of fluid tightness in the sealing joint. However, fluid coupling joints are frequently located in areas where vision can be obscured, and the assembling of the joints must be made out of the direct vision of the worker. In such events, lock wiring is an unsatisfactory means of securing the joint against subsequent loosening. As can also be appreciated, inspection of the joint to ensure its integrity is often compromised. In addition, the lock wiring process can be time consuming. It usually requires drilling a hole in one or more corners of the nut (referred to as B-nut in hydraulic and pneumatic applications) and securing the wire to a boss or other tie-down structure to secure the tie-wire. Moreover, the lock wired connection can cause damage to equipment, and injury to personnel because of the twisted wire ends which easily snag on fabric, equipment, and skin.
[0005] While various other lockwireless coupling assemblies have been disclosed, many of these require multiple or complicated parts to achieve the locking of the connection. Many of these assemblies provide for a lock between the connector and the B-nut. The connector length typically has to be increased to incorporate the locking feature. The increased length of the connector results in increased weight of the coupling, and can also complicate the installation where space is limited.
SUMMARY OF THE INVENTION
[0006] The present invention is directed to a self-locking fluid coupling which eliminates the need for lockwiring the coupling nut while providing ease of installation and good torque resistance, and without requiring detachable locking mechanisms such as locking clips or pins or requiring special tools for assembly. The coupling is utilized to connect two fluid conduits together. An internal ferrule member comprises means for preventing the rotation of the nut member of the coupling once the nut member has been made up in sealing engagement with the connector. Among other forms of rotational locking mechanisms, the means for preventing the rotation of the nut member may comprise a plurality of serrations on the ferrule member wherein one or more of the serrations are engaged by complimentary locking means in the nut member, such as one or more inwardly protruding engagement members. The engagement of the serrations of the ferrule with the engagement members of the nut member creates resistance to circular motion, thereby resisting rotation of the nut member and eliminating the requirement for lockwire to resist rotation of the nut member.
[0007] An embodiment of the coupling comprises a ferrule member, a connector member, and a nut member in cooperative engagement, wherein each of these components comprise axial passageways for passing fluid. The ferrule member is adapted at one end to receive and non-rotationally attach to a first fluid conduit. The other end of the ferrule member, identified herein as the first engagement end, has a sealing surface which, when the coupling is engaged, seals against an opposite facing sealing surface on the connector member. The ferrule member further comprises means for rotationally locking the nut member with respect to the ferrule member. Such rotational locking means may comprise a plurality of axially extending and circumferentially spaced serrations disposed between the end receiving the first fluid conduit and the engagement end.
[0008] The connector member is adapted at one end to receive a second fluid conduit. The opposite facing end of the connector, identified herein as the second engagement end, comprises a sealing surface which is adapted to seal against the first sealing surface of the ferrule member. The connector member comprises fastening means disposed adjacent to the second engagement end.
[0009] The nut member internally receives the first engagement end of the ferrule member, the second engagement end of the connector member, and the rotational locking means of the ferrule member. The nut member comprises fastening means, such as threads, which are adapted to engage the fastening means of the connector member. When the nut member is fully made up with the connector member, the sealing surface of the ferrule member is brought into sealing engagement with the sealing surface of the connector member to prevent leakage across the seal. The nut member may further comprise cantilever members which provide a platform for locating locking means for engaging the serrations of the ferrule member. Between adjacent cantilever members are openings which may facilitate visual confirmation that the serrations of the ferrule member are engaged within the nut member thereby resisting the rotation of the nut member.
[0010] The locking means of the nut member may comprise at least one inwardly protruding lock engagement member disposed on a cantilever member, wherein the lock engagement member is adapted to engage the serrations of the ferrule member when the nut member is made up in full engagement with the connector member and the sealing surface of the ferrule member is brought into sealing engagement with the sealing surface of the connector member to prevent leakage across the seal.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a perspective view of an embodiment of the disclosed coupling.
[0012] FIG. 2 is a side view of an embodiment of the disclosed coupling.
[0013] FIG. 3 is a view from the connector end of an embodiment of the disclosed coupling.
[0014] FIG. 4 is a view from the b-nut end of an embodiment of the disclosed coupling.
[0015] FIG. 5 is an exploded view of an embodiment of the disclosed coupling.
[0016] FIG. 6 is a front view of an embodiment of the b-nut showing a possible configuration of the inwardly protruding lock engagement members.
[0017] FIG. 7 is perspective view of an embodiment of the disclosed coupling in an elbow configuration.
[0018] FIG. 8 is a sectional view of the embodiment shown in FIG. 7 .
[0019] FIG. 9 is a view from the b-nut end of the embodiment shown in FIG. 7 .
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0020] FIG. 1 shows the basic components of an embodiment of the disclosed coupling 10 in an assembled configuration, but shown without the connecting fluid conduits. The coupling 10 comprises a nut member 12 , a connector member 14 , and a ferrule member 16 which is only partially shown in FIG. 1 . As shown in FIG. 2 , the coupling 10 is utilized to connect fluid bearing conduit members which may be disposed in an opposite facing configuration as shown in FIG. 2 , that is, where the fluid bearing conduit members are in axial alignment. An alternative embodiment, as shown in FIG. 7 through 9 may be utilized in which the fluid bearing conduit members are in a ninety-degree configuration.
[0021] First fluid conduit 18 is connected by the coupling 10 to a second fluid conduit 20 . The second fluid conduit 20 is attached and sealed to connector member 14 by means known in the art, such as by welding, dynamic seal beam, flaring, flareless connection, crimping, swaging, lock ring, or other means known to those skilled in the art, which may utilize counter-bores, shoulders, or other internal structures within the connector member corresponding with the attachment means of the second fluid conduit 20 .
[0022] The first fluid conduit 18 is likewise attached to ferrule member 16 and coupled with the nut member 12 such that the end of the ferrule member extends through the end of the nut member. The attachment means utilized for attaching ferrule member 16 to first fluid conduit 18 must not allow rotation of the ferrule member 16 with respect to the first fluid conduit 18 . The coupling 10 must be configured such that when the coupling is made up to connect the two fluid conduits together, a leak-tight seal is created between a first seal face 22 of the ferrule member 16 and a second seal face 24 of the connector member 14 . This type of seal, comprising a frusto-conical section in one seal face and matching surface in the opposing seal face is a dynamic seal wherein increased pressure of the fluid within the passageway works to increase the sealing force between the seal faces.
[0023] Ferrule member 16 is generally cylindrical, having an opening extending through its entire length, where the opening is oriented along the longitudinal axis of the ferrule member. The ferrule member 16 is adapted at one end, designated first end 26 , to receive and non-rotationally attach to the first fluid conduit 18 . The other end of the ferrule member 16 , identified herein as the first engagement end 28 , comprises first seal face 22 . Ferrule member 16 further comprises rotational locking means for preventing the rotation of the nut member 12 once the nut member is made up to the connector member 14 and a leak-tight seal is created between the first seal face 22 of the ferrule member 16 and the second seal face 24 of the connector member 14 . The locking means may comprise various interlocking structures located on the ferrule member 16 and the nut member 12 which engage once the nut member is fully made up to the connector member 14 , such as a keyway and spline combination, or similar types of structures.
[0024] The locking means may also comprise, as shown in the Figures, a plurality of axially extending and circumferentially spaced serrations 30 disposed on the ferrule member 16 between the end 26 receiving the first fluid conduit 18 and the engagement end 28 , wherein one or more inwardly protruding lock engagement members 44 of the nut member 12 engage the serrations 30 . The serrations 30 may be configured such that the side of each serration facing the first engagement end 28 forms a right angle with respect to the longitudinal axis of the ferrule member 16 and the side of each serration facing the conduit receiving end 26 forms an angle of 45 degrees or less with respect to the longitudinal axis of the ferrule member.
[0025] While the number of serrations 30 may vary, it has been found that a configuration wherein the number of serrations varies from a range of 14 to 60 serrations circumferentially disposed about the ferrule member 16 is preferable. Ferrule member 16 may comprise various materials known to those practicing in the art, including plastics, composites, or high strength metal alloys, such as titanium.
[0026] Connector member 14 comprises a second conduit receiving end 32 adapted to receive and attach to a second fluid conduit 20 . Opposite second conduit receiving end 32 is second engagement end 34 . Second engagement end 34 comprises a second seal face 24 which is adapted to seal against the first seal face 22 of the ferrule member 16 . The connector member 14 further comprising fastening means, such as external threads 36 which are disposed adjacent to the second engagement end 34 . As also shown in the figures, connector member 14 may comprise wrench flats 38 to facilitate making up the connector member 14 to the nut member 12 . As shown in FIG. 3 , the wrench flats 38 may be configured in a hexagonal profile.
[0027] Nut member (or B-nut) 12 makes up with connector member 14 such that as torque is applied to the nut member, the threads advance the nut member over the ferrule member 16 such that the nut member internally receives the ferrule member 16 . When the nut member 12 is fully made up to the connector member 14 , first end 26 of the ferrule member 16 extends out through sleeve 40 of the nut member. Nut member 12 further comprises fastening means, such as internal threads 42 , which are adapted to engage the fastening means of the connector member 14 , such as external threads 36 , and make up the connection. When the nut member 12 is made up with the connector member 14 , the first seal face 22 of the ferrule member 16 is brought into sealing engagement with the second seal face 24 of the connector member to prevent leakage across the seal.
[0028] When the nut member 12 is made up with the connector member 14 , the first engagement end 28 of the ferrule member 16 and the second engagement end 34 of the connector member 14 will be internally received by the nut member. The nut member further comprises a plurality of cantilever members 48 which provide a beam for locking onto the serrations 30 of the ferrule member 16 . The number of cantilever members may vary from three to eight, with four being the preferred number. As shown in FIG. 6 , the nut member 12 further comprises one or more inwardly protruding lock engagement members 44 located on one or more of the cantilever members 48 wherein the inwardly protruding lock engagement member 44 is adapted to engage the serrations 30 of the ferrule member 16 when the nut member 12 is made up in full engagement with the connector member 14 and the first sealing face 22 of the ferrule member 16 is brought into sealing engagement with the second seal face 24 of the connector member 14 . Between adjacent cantilever members are openings 50 which facilitate visual confirmation that the serrations 30 of the ferrule member 16 are engaged within the nut member 12 thereby resisting the rotation of the nut member 12 .
[0029] As shown in the figures, nut member 12 may comprise wrench flats 46 to facilitate making up the nut member 12 to the connector member 14 . As shown in FIGS. 3 and 4 , the wrench flats 46 of the nut member 12 may be configured in a hexagonal profile.
[0030] While the disclosed coupling may be configured in a number of different dimensions, it has been found that when utilizing fluid conduits having an outside diameter ranging from 0.025 inch to 1.00 inch, a preferable range for the length of ferrule member 16 is from 0.695 inch to 0.760 inch. It has also been found that a preferable length dimension from the first end 26 to the plurality of axially extending and circumferentially spaced serrations 30 is approximately 0.20 inch, where the dimension is greater than 0.15 inch but not larger than 0.30 inch.
[0031] A preferable range of lengths of connector member 14 are 0.798 inch to 1.103 inch. A preferable range of lengths of nut member 12 are 0.679 inch to 1.020 inch.
[0032] FIGS. 7 through 9 show an alternative embodiment of the coupling 10 ′ which show the nut member 12 ′ attached to an elbow assembly 52 , where ferrule member 16 ′ has serrations 30 ′. Lock engagement members 44 ′ engage serrations 30 ′ of the ferrule member 16 ′, thereby resisting the rotation of the nut member 12 ′. Clip wire 54 retains the ferrule member 16 ′ within the nut member 12 ′ prior to making the nut member up to an opposite facing connector member 14 and second fluid conduit 20 (not shown), but does not prevent rotation of nut member 12 ′ to engage the threads of the connector member. In this embodiment the longitudinal axis of the first fluid conduit 18 ′ is at an angle of approximately ninety degrees of the longitudinal axis of the second fluid conduit 20 ′.
[0033] While the above is a description of various embodiments of the present invention, further modifications may be employed without departing from the spirit and scope of the present invention. For example, the size, shape, and/or material of the various components may be changed as desired. Thus the scope of the invention should not be limited by the specific structures disclosed. Instead the true scope of the invention should be determined by the following claims. | A self-locking fluid coupling, utilized to connect two fluid conduits together, does not require the lockwiring of the coupling nut to prevent the rotation of the coupling nut. The locking mechanism comprises a rotational locking means on a ferrule member. The rotational locking means engage one or more inwardly protruding engagement members of the B-nut. The engagement of the rotational locking means of the ferrule with the engagement members of the B-nut creates resistance to circular motion, thereby resisting rotation of the B-nut and eliminating the requirement for lockwire to resist rotation of the B-nut. | 5 |
This is a division of application Ser. No. 944,540, filed 9/21/78 now U.S. Pat. No. 4,477,397.
NATURE OF THE INVENTION
This invention relates to the manufacture of hydrous calcium silicate insulating products from slurried calcareous and siliceous components.
BACKGROUND OF THE INVENTION
The term hydrous calcium silicate denotes a crystalline compound formed by the reaction of lime (CaO), silica (SiO 2 ), and water (H 2 O). The two hydrous calcium silicates that generally are of interest are: tobermorite having the formula 4CaO.5SiO 2 .5H 2 O; and xonotlite, having the formula 5CaO.5SiO 2 .XH 2 O. Hydrous calcium silicate products often are used as heat insulation materials.
Methods for reacting and drying a molded aqueous slurry of reactive cementitious constituents and reinforcing fibers to form hydrous calcium silicate insulation products are known in the art. One such method includes placing a molded slurry of the reactive cementitious constituents and reinforcing fibers in an autoclave, introducing pressurized saturated steam into the autoclave to indurate the slurry, and removing the products from the autoclave. Another such method includes placing a molded slurry of the reactive cementitious constituents and reinforcing fibers in an autoclave, introducing pressurized saturated steam into the autoclave to indurate the slurry, simultaneously further indurating and drying the slurry with superheated steam to convert the slurry to a final product, reducing the pressure in the autoclave to atmospheric pressure and removing of the product.
In practice the principal slurry constituents, i.e. calcareous and siliceous materials, reinforcing fibers and water are mixed to form a slurry which is then molded to impart a predetermined shape to the slurry and final product. The slurry is molded or shaped in any convenient manner. Generally, however, one of two types of molds is employed, i.e. pan molds or filter press molds. In pan molds, the slurry remains in the mold while the cementitious materials are reacted to convert them to a hydrous calcium silicate insulation. A pan mold generally defines a mold cavity of a particular shape and dimension; e.g. a flat rectangular pan is used to form flat ware or blocks, while an arcuate, generally U-shaped mold forms half-section insulation pieces used to form molded pipe covering for insulating pipes, ducts, and the like. The filter press mold generally comprises a perforated molding surface over which the slurry is poured. A perforated mechanical piston, complementary in shape to the mold, compresses the slurry and dewaters it to the point where it is self-supporting. The filter press molding technique is conducted in the absence of any applied heat and under pressure sufficient only to express water from the slurry in the filter press and to form solid articles such as pipe covering nd flat ware. At this point the molded slurry becomes the product defined as "greenware" in this description. The filter press molding technique is described in U.S. Pat. No. 2,699,097.
The greenware is further cured to the desired hydrous calcium silicate product by several methods. One method introduces pressurized, saturated steam into a closed system or autoclave in sufficient amount to bring the pressure in the autoclave from 100 to 350 psi at a temperature ranging from 328°-406° F. in 30 minutes or less and preferably within 15 to 30 minutes after the introduction of the steam begins. (The term "pressure" as used herein refers to gauge pressure (in pounds per square inch), i.e. the pressure above that of the atmosphere.).
The greenware is then maintained under this steam pressure in an autoclave for a period of time sufficient to indurate it. After the product has been removed from the autoclave, it can be dried in an auxiliary drier, if required. The drying temperature in the auxiliary drier must be below the decomposition point of the organic fiber reinforcement to achieve the best possible strength of the product.
The other method disclosed herein introduces pressurized, saturated steam into a closed system or autoclave in sufficient amount to bring the pressure in the autoclave from 100 to 350 psi in 30 minutes or less and preferably within 15 to 30 minutes after the introduction of steam begins. (The term pressure as used herein refers to gauge pressure (in pounds per square inch), i.e. the pressure above that of the atmosphere.) After the introduction of the steam, the temperature in the autoclave is raised by heating coils to a temperature ranging from about 407° to about 600° F. to produce the superheated steam.
The greenware is then maintained in the autoclave until a perdetermined percentage of the moisture (by weight) of the ware has been removed by evaporation into the superheated steam atmosphere. The free moisture is reduced substantially during the cycle, but never drops below 10% by weight of solids during the entire cycle. While continuing to circulate the steam in the system, the pressure in the autoclave is reduced to atmospheric conditions within 60 minutes or less and the final product is removed. The product subsequently can be dried in an auxiliary drier, if required. The drying temperatures in the auxiliary drier must be below the decomposition point of the organic fiber reinforcement, or a brittle product is obtained. The retention of at least 10% by weight-free moisture in the molded slurry allows for simultaneous indurating and drying in an autoclave at temperatures above the decomposition point of the reinforcing organic fibers.
An important step in the overall process is the gel formation step prior to molding the slurry. After a mixture of pulverized siliceous and calcareous materials are suspended in an aqueous slurry sufficient time must be allotted for the slurry to gel before it can be processed further. This period of gelation is necessary to permit the formation of a thickened slurry. Gelation requires alternate quiescent periods for allowing the formation of nucleated solids followed by gentle agitation.
I have now discovered that the addition of pulverized greenware material derived from the initial filter press molding of the slurry in the absence of applied heat substantially decreases the amount of time required for this preliminary gelation step.
SUMMARY OF THE INVENTION
Briefly stated, this invention comprises a process for making hydrous calcium silicate insulation products from aqueous slurries of calcareous and siliceous materials comprising:
(a) preparing a water dispersion of reactive calcareous and siliceous containing materials;
(b) gelling the dispersion by heating at a temperature of approximately 180°-210° F.;
(c) molding said partially gelled dispersion under pressure and expressing water therefrom thereby converting the gelled dispersion to greenware;
(d) unmolding said greenware and selecting those greenware articles to be recycled;
(e) completing the curing of the remaining molded articles;
(f) pulverizing selected greenware articles from step (d) and adding said particulated material to the dispersion of step (a) in a subsequent cycle of the process.
DESCRIPTION OF THE INVENTION
The specific lime to silica ratio of the slurry is dependent primarily upon the desired type of crystalline hydrous silicate desired in the final product. For example, if it is desired to obtain a crystalline product predominantly composed of a crystalline matrix structure of the type commonly referred to as xonotlite (5CaO.5SiO 2 .XH 2 O), a CaO/SiO 2 mol ratio of approximately 1/1 would be utilized in the slurry. If the desired cyrstalline product is tobermorite having the formula 4CaO.5SiO 2 .5H 2 O, a CaO/SiO 2 mol ratio ranging from 0.75/1 to 0.80/1 would be employed in the slurry. In general, the CaO/SiO 2 molar ratio ranges from 0.65/1 to 1.3/1.
Control of the density of the resultant product is primarily accomplished by controlling the relative amount of water utilized in the make-up of the slurry. For example, an apparent density of 11 pounds per cubic foot, which may be considered a nominal apparent density, would be obtained utilizing a slurry having a ratio of water to total dry solids of approximately 6:1.
The siliceous materials employed in this invention include portland cement, siliceous sand, quartz, diatomaceous earth, clays, silica gel, pozzolana, perlite, and the like and mixtures thereof.
The calcareous materials used in this invention include portland cement, quick lime, slaked lime and the like and mixtures thereof.
The organic materials of this invention are cellulosic fibers such as fibers of pulp fiber, cotton, straw, bagasse, wood flour, hemp, rayon and the like. A preferred pulp fiber is bleached softwood pulp. Alkali-resistent glass fibers can be employed with the cellulosic material.
In the method of this invention the cementitious materials noted above in water are mixed in a hydrapulper to form a slurry and the pulverized particulated greenware from a previous cycle is added to the slurry composition. The slurry is transferred to a holding tank fitted with an agitator and preferably maintained at a temperature ranging from 60° to 90° F. The addition of the particulated greenware has the effect of shortening the length of time required for the slurry to reach the proper consistency for further processing. The particulated greenware is added in an amount up to about 30% by weight of the total solids material. Preferably, it is added in an amount between about 10 and 20 percent of the total weight of the solids. A maximum particle size is 1/4 inch mesh size. The incorporation of this material into the gel mixture now reduces the gelation time from an average, for example, of 105 minutes to 70 minutes. This is, of course, a substantial reduction in the gelation time required.
After the slurry has gelled to a proper consistency it is molded into articles by filter press molding techniques. This technique is well known to those skilled in the art and as noted previously comprises molding the slurry under sufficient pressure to express some of the water therefrom and to provide solid articles which are the greenware of this description. These solid articles are inspected and those articles found not to be suitable because of breakage or undesired dimensions are removed and pulverized to a particle size of not greater than 1/4 inch mesh size.
This molded slurry (greenware) is then subjected to pressurized saturated steam in a closed system or autoclave in an amount sufficient to bring the pressure in the autoclave to 100 to 350 psi at a temperature ranging from 328° to 406° F. in 30 minutes or less and preferably within 15 to 30 minutes after the introduction of the steam begins. The term "pressure" is pounds per square inch, gauge. The slurry is maintained under this pressure for a period of time sufficient to indurate the slurry. Curing to form the final desired hydrated calcium silicate product is completed by additional heating, for example with superheated steam at 407° to 600° F., or other temperatures as will be known to those skilled in the art.
EXAMPLE
A low density hydrated calcium silicate heat insulation material is made from the following materials, in parts by weight of solids.
______________________________________MATERIALS PARTS BY WEIGHT (Dry)______________________________________Quick lime 34.78Diatomaceous earth 21.4(86 sq. ft. per gram)Diatomaceous earth 29.96(54 sq. ft. per gram)Wood pulp 6.5Glass and Rayon fibers 1.06Particulated recycled 6.29greenware______________________________________
A dispersion of the various materials is made by dispersing the wood pulp in 350 parts by weight of water heated to 200° F. in a hydrated pulper to produce a dispersion. This dispersion of the wood pulp is then added to a premixer wherein the hydrated lime is added and mixed for 1 minute. Another 900 parts by weight of water at 200° F. is added to another premixer and the diatomaceous earth and pulverized greenware is added thereto and mixed for 1 minute. Thereafter the contents of the two premixers are added to a gel tank wherein the materials are thoroughly mixed for 10 minutes. The resulting slurry or suspension of ingredients is then premitted to gel and a gelation time of only about 70 minutes is required. The gel so produced is then drawn off in small quantities to a volumetric tank in precise quantities for charging a precision type filter mold shaped to make 3 inch annular pipe insulation of 11/2 inch wall thickness and a length of 36 inches. The ram of the mold compresses the gel to force the water out through the cylindrical filter forming the inside surface of the pipe insulation to leave a pipe insulation which is self sustaining and handleable. The block is then removed from the filter mold and now, in its greenware condition is inspected. Unsatisfactory portions are removed. The remaining block is stacked in a rack which when filled is rolled into an autoclave for induration. After the autoclave is sealed, the pressure in the autoclave is raised to 175 psi over a 30-minute cycle and the blocks are subjected to saturated steam at this pressure for 11/2 hours. Thereafter the temperature in the autoclave is raised by heating coils to 600° F. to produce superheated steam which slowly dries the blocks over another 2-hour period. The autoclave is then depressurized over a 1/2-hour period, and the racks which hold the insulation block are removed from the autoclave. The material so produced has a modulus of rupture of 115 psi and a density of 12.5 lbs. per cubic foot.
While the invention has been described in considerable detail I do not wish to be limited to the particular embodiments shown and described and it is my intention to cover hereby all novel adaptations, modifications and arrangements thereof which come within the practice of those skilled in the art to which this invention relates. | Off-size greenware (the product resulting from the initial gelation and filter pressing of calcareous and siliceous materials in an aqueous slurry) is recycled. The greenware is pulverized into a desirable size and combined with new calcareous and siliceous materials in the initial slurrying step. The slurry containing recycled greenware gels at an improved rate. | 2 |
BACKGROUND OF THE INVENTION
The present invention relates to a load condition detection device for an induction motor and a load condition detecting method for the same.
A description will be given herein by taking a load imbalance detection device for a three-phase induction motor driven by an inverter as an example, but the invention is applicable to a variety of induction motors. Further, the variable-frequency, variable-voltage application power supply employed with the invention is also not limited to an inverter.
FIG. 18 shows a block diagram of a conventional load condition detection device for a three-phase induction motor. Here, load imbalance detection of a three-phase induction motor is described by taking a washing machine as an example. In FIG. 18, reference numeral 1 indicates an AC power supply, 51, an inverter; 6, a three-phase induction motor; 7, a load of the three-phase induction motor; and 50, a photosensor which is installed outside the outer peripheral surface of the rotational load.
When the load 7 is balanced, it rotates without eccentricity with respect to the center of rotation, and thus the photosensor 50 does not operate. If though the laundry collects on one side so that the load becomes unbalanced and rotates eccentrically more than a predetermined amount with respect to the center of rotation, the photosensor operates and detects the imbalanced condition of the load.
In the conventional load condition detection device for a three-phase induction motor 6, it is necessary to set the photosensor 50 individually in response to the amount of eccentricity of the load when the load is unbalanced. To detect slight eccentricity, the position of the photosensor 50 needs to be set precisely. Since the position of the photosensor 50 changes with time due to vibration when the three-phase induction motor 6 turns, etc., periodic position adjustment is required.
SUMMARY OF THE INVENTION
It is therefore an object of the invention to provide a load condition detection device for a three-phase induction motor which can easily detect load imbalance without change over time, enables easy change of the imbalance detection level, and eliminates the need for an optical device such as a photosensor, thereby reducing load imbalance detection costs.
According to the invention, there is provided a load condition detection device for an induction motor which causes rotational motion of a load when a predetermined current is input, the load condition detection device comprising a current detection means for detecting the instantaneous value of the input current, average current detection means for detecting an output current average value based on the current instantaneous value and a predetermined average time, current value comparison means for determining the difference between the current instantaneous value and the current average value, counting means for comparing the value obtained by the current value comparison means with a first predetermined value and counting the number of times the obtained value exceeds the predetermined value, and means for stopping motion of the load if the value counted by the counting means within a predetermined time exceeds a second predetermined value.
According to the invention, there is provided a load condition detection device for an induction motor effecting rotation of a load when a predetermined current is input, the load condition detection device comprising a current detection means for detecting a current instantaneous value of the current, average current detection means for determining a current average value based on the current instantaneous value and a predetermined average time, current value comparison means for determining a difference between the current instantaneous value and the current average value, counting means for comparing the value obtained by the current value comparison means with a first predetermined value and counting the number of times the obtained value has exceeded the predetermined value, and alarm means for informing the user that the load is in an imbalanced condition.
According to the invention, there is provided an induction motor load condition detection method comprising the steps of detecting the instantaneous value of a current for a load, determining a current average value of the current instantaneous values for a predetermined average time thereof, determining an absolute value of a difference between the output current instantaneous value and the current average value, detecting the number of times the absolute value exceeds a predetermined value, and outputting a load condition detection signal in response to the detection value.
According to the invention, there is provided an induction motor load condition detection method comprising the steps of detecting a current instantaneous value of q-axis current into which a current for a load is converted by d-q-axis current conversion means, determining a q-axis current average value of the current instantaneous values for a predetermined average time thereof, determining an absolute value of a difference between the q-axis current instantaneous value and the q-axis current average value, detecting the number of times the absolute value exceeds a predetermined value, and outputting a load condition detection signal in response to the detection value.
According to the invention, there is provided an induction motor load condition detection method comprising the steps of detecting a current instantaneous value of a current for a load, determining a first current average value for a first predetermined average time sufficiently short as compared with the load period of the current instantaneous values and a second current average value for a second predetermined average time sufficiently long as compared with the load period, determining an absolute value of a difference between the first and second current average values, detecting the number of times the absolute value exceeds a predetermined value, and outputting a load condition detection signal in response to the detection value.
According to the invention, there is provided an induction motor load condition detection method comprising the steps of detecting a current instantaneous value of a current for a load, determining a current average value of the current instantaneous values for a predetermined average time thereof, determining an absolute value of a difference between the current instantaneous value and the current average value, detecting the number of times a case occurs where the absolute value exceeds a predetermined value and differs in polarity from the preceding difference current exceeding the predetermined value, and outputting a load condition detection signal in response to the detection value.
In the inventive method, the number of times the absolute value exceeds the predetermined value is detected every predetermined time, and only when the predetermined number of times is exceeded within the predetermined time, the load condition detection signal is output.
In the method, the load condition detection signal is output by load condition detection start and end signals.
Also, in the method of the invention, a specified frequency is compared with an output frequency for determining whether-or not running at constant speed is being performed, and if it is determined that running at constant speed is being performed, the load condition detection operation is started by a signal indicating running at constant speed.
The load condition detection device for an induction motor effecting rotation of a load when a predetermined current is input comprises a current detection means for detecting a current instantaneous value of the input current, average current detection means for determining a current average value based on the current instantaneous value and a predetermined average time, current value comparison means for determining a difference between the current instantaneous value and the current average value, counting means for comparing the value obtained by the current value comparison means with a first predetermined value and counting the number of times the obtained value has exceeded the predetermined value, and means for stopping the rotation of the load if the value counted by the counting means within a predetermined time exceeds a second predetermined value.
The load condition detection device for an induction motor effecting rotation of a load when a predetermined current is input comprises a current detection means for detecting a current instantaneous value of the current, average current detection means for determining a current average value based on the current instantaneous value and a predetermined average time, current value comparison means for determining a difference between the current instantaneous value and the current average value, counting means for comparing the value obtained by the current value comparison means with a first predetermined value and counting the number of times the obtained value has exceeded the predetermined value, and alarm means for informing the user that the load is in an imbalanced condition.
The induction motor load condition detection method of the invention comprises the steps of detecting a current instantaneous value of a current for a load, determining a current average value of the current instantaneous values for a predetermined average time thereof, determining an absolute value of the difference between the current instantaneous value and the current average value, detecting the number of times the absolute value exceeds a predetermined value, and outputting a load condition detection signal in response to the detection value.
The induction motor load condition detection method comprises the steps of detecting a current instantaneous value of q-axis current into which a current for a load is converted by d-q axis current conversion means, determining a q-axis current average value of the current instantaneous values for a predetermined average time thereof, determining an absolute value of a difference between the q-axis current instantaneous value and the q-axis current average value, detecting the number of times the absolute value exceeds a predetermined value, and outputting a load condition detection signal in response to the detection value.
The induction motor load condition detection method comprising the steps of detecting a current instantaneous value of a current for a load, determining a first current average value for a first predetermined average time sufficiently short as compared with a load period of the current instantaneous values and a second current average value for a second predetermined average time sufficiently long as compared with the load period, determining an absolute value of a difference between the first and second current average values, detecting the number of times the absolute value exceeds a predetermined value, and outputting a load condition detection signal in response to the detection value.
The induction motor load condition detection method comprises the steps of detecting a current instantaneous value of an input current for a load, determining a current average value of the current instantaneous values for a predetermined average time thereof, determining an absolute value of a difference between the current instantaneous value and the current average value, detecting the number of times a case occurs where the absolute value exceeds a predetermined value and differs in polarity from the preceding difference current exceeding the predetermined value, and outputting a load condition detection signal in response to the detection value.
The number of times the absolute value exceeds the predetermined value is detected every predetermined time, and only when the predetermined number of times is exceeded within predetermined time, the load condition detection signal is output.
The load condition detection signal is output by load condition detection start and end signals.
A specified frequency is compared with an output frequency for determining whether or not running at constant speed is being performed, and if it is determined that running at constant speed is being performed, the load condition detection operation is started by a signal indicating running at constant speed.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings:
FIG. 1 is a block diagram showing a load condition detection device for a three-phase induction motor according to first to fifth embodiments of the invention;
FIG. 2 is a flowchart showing an Operation 1 of the load condition detection device for the three-phase induction motor in FIG. 1;
FIG. 3 is a current waveform diagram showing the operation of a load unbalance detection means of the load condition detection device;
FIG. 4 is a flowchart showing an Operation 2 of the load condition detection device for the three-phase induction motor in FIG. 1;
FIG. 5 is a current waveform diagram showing the operation of a load unbalance detection means of the load condition detection device;
FIG. 6 is a flowchart showing an Operation 3 of the load condition detection device for the three-phase induction motor in FIG. 1;
FIG. 7 is a flowchart showing an Operation 4 of the load condition detection device of the three-phase induction motor in FIG. 1;
FIG. 8 is also a flowchart following the flowchart of FIG. 7;
FIG. 9 is a current waveform diagram showing an Operation 4 of a load unbalance detection means of the load condition detection device;
FIG. 10 is a flowchart showing an Operation 5 of the load condition detection device for the three-phase induction motor in FIG. 1;
FIG. 11 is a block diagram showing a load condition detection device for a three-phase induction motor according to a sixth embodiment of the invention;
FIG. 12 is a flowchart showing the operation of the load condition detection device for the three-phase induction motor in FIG. 11;
FIG. 13 is a block diagram showing a load condition detection device for a three-phase induction motor according to a seventh embodiment of the invention;
FIG. 14 is a flowchart showing the operation of the load condition detection device for the three-phase induction motor in FIG. 13;
FIG. 15 is a current waveform diagram showing an operation of the load condition detection device for FIG. 13;
FIG. 16 is a block diagram showing a load condition detection device for a three-phase induction motor according to an eighth embodiment of the invention;
FIG. 17 is a block diagram showing a load condition detection device for a single-phase induction motor according to a ninth embodiment of the invention; and
FIG. 18 is a block diagram of a conventional load condition detection device for a three-phase induction motor.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is a block diagram showing a load condition detection device for a three-phase induction motor constructed according to first to fifth embodiments of the invention. In FIG. 1, reference numeral 1 is an AC power supply; 2, a converter section of an inverter; 3, a smoothing capacitor of the inverter; 4, an inverter section of the inverter; 5, an electric current detector of the inverter; 6, a three-phase induction motor; 7, a load of the three-phase induction motor; 8, a control section of the inverter; 9, an input section of the inverter for inputting a run command and a setup value; 11, an electric current converter for converting a three-phase current detected by the three-phase current detector 5 into a d-q axis current rotating in synchronization with an output frequency and determining a d-axis current, an excitation phase current in vector control and a q-axis current, and a torque phase current; 12, output frequency and voltage calculation unit for calculating an output frequency and an output voltage from the setup value from the input section 9 and the d-axis current and q-axis current from the current converter 11; 13, load imbalance detector for detecting current fluctuation occurring secondarily as a result of load imbalance from the d-axis current and q-axis current from the current converter 11; 14, an output section for outputting a signal to the external upon detection of load imbalance; 51, the overall inverter.
FIG. 2 is a flowchart showing Operation 1 of the load imbalance detector 13 of the load condition detection device for the three-phase induction motor in FIG. 1. In the figure, reference numeral 201 is a step at which an elapsed time counter t and the number of times, n, imbalance has occurred are cleared to 0, numeral 202 is a step at which averaging time T1, a threshold value I th , and a setup value X of the number of count times are read from the input section 9, numeral 203 is a step at which the elapsed time from detection start is set, numeral 204 is a step at which the d-axis current and q-axis current from the current converter 11 are read, numeral 205 is a step at which an output current instantaneous value is calculated, numeral 206 is a step at which an average current value i calculated, numeral 207 is a step at which whether or not the time elapsed is equal to or greater than the averaging time T1 is determined, numeral 208 is a step at which the absolute value of the difference between the output current instantaneous value and the output current average value, I ab , is calculated, numeral 209 is a step at which whether or not I ab is greater than the threshold value I th is determined, numeral 210 is a step at which 1 is added to the number of times, n, imbalance has occurred, numeral 211 is a step at which whether or not the number of times, n, imbalance has occurred is greater than the setup value, X, of the number of count times is determined, and numeral 212 is a step at which an imbalance detection signal is output.
The operation of the embodiment will now be discussed. In FIG. 1, the inverter 51 executes three-phase full-wave rectification of an AC voltage of the AC power supply 1 by the converter section 2 and smooths the result through the smoothing capacitor 3 for conversion to DC. Then, the inverter section 4 again converts the DC into an AC voltage having the frequency and voltage calculated by the calculation unit 12 based on a command value from the input section 9 and outputs the AC voltage for driving the three-phase induction motor 6 for rotating the load 7. At the time, the three-phase current detector 5 detects the three-phase output current of the inverter and the current converter 11 converts the three-phase output current into the d-q axis rotating in synchronization with the output frequency for determining d-axis current and q-axis current. The output frequency and voltage calculation unit 12 uses the d-axis current and q-axis current to perform primary voltage correction control and slip correction control. The load imbalance detector 13 has an output current calculation section 13a for calculating an output current instantaneous value from a d-axis current instantaneous value, a q-axis current instantaneous value, an average current calculation section 13b for averaging the output current instantaneous values for the predetermined averaging time to determine an average current, a current value comparison section 13c for determining the difference between the output current instantaneous value and the output current average value, and a count section 13d for counting the number of times the current value difference has exceeded a predetermined value. When the count exceeds a predetermined value, the load imbalance detector 13 judges that the load is unbalanced and detects imbalance of the load of the three-phase induction motor, then outputs a signal through the output section 14. When the load is well balanced during normal constant-speed running, the output current is constant; when the load is unbalanced, for example, if laundry collects on one side in the tub of a washing machine, the rotation shaft of the three-phase induction motor 6 is not steady but it moves in the manner of a wooden pestle, causing the output current to fluctuate.
The current fluctuation is detected by the load imbalance detector 13, as shown the flowchart of FIG. 2.
At step 201, the elapsed time counter t and the number of times, n, imbalance has occurred are cleared to 0 as an initial reset. At step 202, the averaging time T1 sufficiently longer than the period of output frequency at constant-speed time, threshold value I th , and setup value, X, of the number of count times set through the input section 9 are read. At step 203, the elapsed time is set in the counter t. At step 204, the d-axis current I d and q-axis current I q are read from the current converter 11. At step 205, an output current instantaneous value I 0UT is calculated by the output current calculation section 13a. The reason why the d-axis current I d and q-axis current I q are used to calculate the output current instantaneous value is that the d-axis current I d and q-axis current I q are already calculated for use by the output frequency and voltage calculation unit 12 and are orthogonal components for facilitating calculation of the output current instantaneous value and that dedicated hardware is not required for determining the output current instantaneous value by executing full-wave rectification of the three-phase output current.
Next, at step 206, an average value of output current until t-T1 before the averaging time T1 from the elapsed time t is calculated by the average current calculation section 13b. The output current average value I av is updated each time t has elapsed. At step 207, whether or not the elapsed time is equal to or greater than the averaging time T1 is determined for judging that calculation of the first output current average value I av is complete. If the elapsed time t is less than the averaging time T1, calculation of the first output current average value I av is not complete. Then, control returns to step 203.
If t>T1, calculation of the first output current average value I av is complete. Then, at step 208 and 209, the absolute value I ab of the difference between the output current instantaneous value I 0UT and the output current average value I av is calculated by the current value comparison section 13c and the threshold value I th read at step 202 is compared with the absolute value of the difference, I ab . In the comparison, if the load is balanced at the constant-speed time, output current instantaneous value I 0UT ≈output current average value I av as shown in FIG. 3 and therefore I ab ≈0; if the load is unbalanced, the output current fluctuates and therefore I ab ≈0 does not result as shown in FIG. 3 and I ab >I th . Here, the threshold value I th is set to detect output current fluctuation when the load is unbalanced without detecting a minute output current instantaneous value when the load is balanced. When the load is balanced, the setup value of I th is increased gradually and is set to a value greater than the value at which the number of times imbalance has occurred is not counted. When I ab >I th by the count section 13d at step 209, 1 is added to the number of times, n, imbalance has occurred at step 210. If I ab ≦I th , the load is judged to be balanced, and control returns to step 203. At step 211, whether or not the number of times, n, imbalance has occurred is greater than the setup value, X, of the number of count times read at step 202 is determined. If n>X, the load is judged to be unbalanced and an imbalance detection signal is output at step 212. If n≦X, control returns to step 203. Since current fluctuation repeatedly occurs when the load is unbalanced, the instantaneous output current I 0UT will change momentarily for a different reason and the number of times, n, imbalance has occurred may be counted, outputting an imbalance detection signal in error. The number-of-count-times setup value X is set to prevent this error from occurring.
Thus, although the conventional detection device detects load imbalance as physical displacement, the detection device according to the embodiment detects load imbalance electrically. Therefore, there is provided a load condition detection device for a three-phase induction motor which enables easy change of load imbalance detection level and has detection precision not changing with time at low costs.
FIG. 4 is a flowchart showing Operation 2 of the load imbalance detector 13 of the load condition detection device for the three-phase induction motor in FIG. 1. In the figure, reference numeral 301 is a step at which an elapsed time counter t and the number of times, n, imbalance has occurred are cleared to 0, numeral 302 is a step at which averaging time T1, a threshold value I th , and a setup value, X, of the number of count times are read from the input section 9, numeral 303 is a step at which the elapsed time from detection start is set, numeral 304 is a step at which the q-axis current instantaneous value is read from the current converter 11, numeral 305 is a step at which a q-axis current average value is calculated, numeral 306 is a step at which whether or not the time elapsed is equal to or greater than the averaging time T1 is determined, numeral 307 is a step at which the absolute value of the difference between the q-axis current instantaneous value and the q-axis current average value, I ab , is calculated, numeral 308 is a step at which whether or not I ab is greater than the threshold value I th is determined, numeral 309 is a step at which 1 is added to the number of times, n, imbalance has occurred, numeral 310 is a step at which whether or not the number of times, n, imbalance has occurred is greater than the setup value, X, of the number of count times is determined, and numeral 311 is a step at which an imbalance detection signal is output.
FIG. 5 is a current waveform diagram showing the Operation 2 of the load unbalance detector 13 shown in FIG. 1.
The operation of the embodiment will now be discussed.
At step 301, the elapsed time counter t and the number of times, n, imbalance has occurred are cleared to 0 as an initial reset. At step 302, the averaging time T1 sufficiently longer than the period of output frequency at constant-speed time, threshold value I th , and setup value, X, of the number of count times set through the input section 9 are read. At step 303, the elapsed time is set in the counter t. At step 304, only the q-axis current instantaneous value I q is read from the current converter 11. The q-axis current instantaneous value I q is a torque component current and output current fluctuation when the load is unbalanced is mainly a torque change. Thus, if the q-axis current instantaneous value I q is used for detection, a large change appears.
Next, at step 305, a q-axis current average value until t-T1 before the averaging time T1 from the elapsed time t is calculated. The q-axis current average value I qav is updated each time the elapsed time t has elapsed. At step 306, whether or not the elapsed time is equal to or greater than the averaging time T1 is determined for judging that calculation of the first q-axis current average value I qav is complete. If the elapsed time t is less than the averaging time T1, calculation of the first q-axis current average value I qav is not complete. Then, control returns to step 303. If t>T1, calculation of the first q-axis current average value I qav is complete. Then, at step 307, the absolute value I ab of the difference between the q-axis current instantaneous value I q and the q-axis current average value I qav is calculated. At step 308, the threshold value I th read at step 302 is compared with the absolute value of the difference, I ab . In the comparison, if the load is balanced at the constant-speed time, the q-axis current instantaneous value I q ≈q-axis current average value I qav , and therefore I ab ≈0; if the load is unbalanced, the q-axis current instantaneous value I q fluctuates and therefore I ab ≈0 does not result and I ab >I th . The threshold value I th is set to detect q-axis current fluctuation when the load is unbalanced without detecting a minute q-axis current instantaneous value I q when the load is balanced. When the load is balanced, the setup value of I th is increased gradually and is set to a value greater than the value at which the number of times imbalance has occurred is not counted.
When I ab >I th at step 308, 1 is added to the number of times, n, imbalance has occurred at step 309. If I ab ≦I th , the load is judged to be balanced, and control returns to step 303. At step 310, whether or not the number of times, n, imbalance has occurred is greater than the setup value, X, of the number of count times read at step 302 is determined. If n>X, the load is judged to be unbalanced and an imbalance detection signal is output at step 311. If n≦X, control returns to step 303. Since current fluctuation repeatedly occurs when the load is unbalanced, the q-axis current instantaneous value I q will change momentarily for a different reason and the number of times, n, imbalance has occurred may be counted, outputting an imbalance detection signal in error. The number-of-count-times setup value X is set to prevent this error from occurring.
Thus, load imbalance can be easily detected stably with high precision by using only the q-axis current instantaneous value without the d-axis current instantaneous value.
FIG. 6 is a flowchart showing Operation 3 of the load imbalance detector 13 of the load condition detection device for the three-phase induction motor in FIG. 1. In the figure, numeral 401 is a step at which an elapsed time counter t and the number of times, n, imbalance has occurred are cleared to 0, numeral 402 is a step at which averaging time T1, second averaging time T2, a threshold value I th , and a setup value, X, of the number of count times are read from the input section 9, numeral 403 is a step at which the elapsed time from detection start is set, numeral 404 is a step at which the d-axis current and q-axis current from the current converter 11 are read, numeral 405 is a step at which an output current instantaneous value is calculated, numeral 406 is a step at which a second output current average value is calculated, numeral 407 is a step at which a first output current average value is calculated, numeral 408 is a step at which whether or not the time elapsed is equal to or greater than the averaging time T1 is determined, numeral 409 is a step at which the absolute value of the difference between the second output current average value and the first output current average value, I ab , is calculated, numeral 410 is a step at which whether or not I ab is greater than the threshold value I th is determined, numeral 411 is a step at which 1 is added to the number of times, n, imbalance has occurred, numeral 412 is a step at which whether or not the number of times, n, imbalance has occurred is greater than the setup value, X, of the number of count times is determined, and numeral 413 is a step at which an imbalance detection signal is output.
The operation of the embodiment will now be discussed.
At step 401, the elapsed time counter t and the number of times, n, imbalance has occurred are cleared to 0 as an initial reset. At step 402, the averaging time T1 sufficiently long as compared with the period of output frequency of the inverter at constant-speed time and therefore the load rotation period, the second averaging time T2 sufficiently short as compared with the load rotation period, current value threshold value I th , and setup value, X, of the number of count times set through the input section 9 are read. At step 403, the elapsed time is set in the counter t. At step 404, the d-axis current I d and q-axis current I q are read from the current converter 11. At step 405, an output current instantaneous value I OUT is calculated.
Next, at step 406, a second output current average value until t-T2 before the second averaging time T2 from the elapsed time t is calculated. The second output current average value I av2 is set to a value sufficiently shorter than the averaging time T1 and longer than the read period of the current value from the current converter 11 at step 404 in order to prevent the threshold value I th from being set too large and load imbalance from being unable to be detected if the output current instantaneous value I 0UT is affected by noise or the like and fluctuations. The second average current value is updated each time the elapsed time t has elapsed.
Next, at step 407, a first output current average value until t-T1 before the averaging time T1 from the elapsed time t is calculated. The first output current average value I av is updated each time the elapsed time t has elapsed. At step 408, whether or not the elapsed time is equal to or greater than the averaging time T1 is determined for judging that calculation of the initial first output current average value I av is complete. If the elapsed time t is less than the averaging time T1, calculation of the initial first output current average value I av is not complete. Then, control returns to step 403. If t>T1, calculation of the initial first output current average value I av is complete. Then, control advances to step 409. Since the average time is shorter than T1, the second output current average value I av2 is calculated at this point in time. Subsequently, at step 409, the absolute value I ab of the difference between the second output current average value I av2 and the first output current average value I av is calculated. At step 410, the threshold value I th read at step 402 is compared with the absolute value of the difference, I ab . In the comparison, if the load is balanced at the constant-speed time, second output current average value I av2 ≈first output current average value I av and therefore I ab ≈0; if the load is unbalanced, the second output current average value I av2 fluctuates and therefore I ab ≈0 does not result, and I ab >I th . Here, the threshold value I th is set to detect output current fluctuation when the load is unbalanced without detecting a minute second output current average value I av2 when the load is balanced. When the load is balanced, the setup value of I th is increased gradually and is set to a value greater than the value at which the number of times imbalance has occurred is not counted.
When I ab >I th at step 410, 1 is added to the number of times, n, imbalance has occurred at step 411. If I ab ≦I th , the load is judged to be balanced, and control returns to step 403. At step 412, whether or not the number of times, n, imbalance has occurred is greater than the setup value, X, of the number of count times read at step 402 is determined. If n>X, the load is judged to be unbalanced and an imbalance detection signal is output at step 413. If n≦X, control returns to step 403. Since current fluctuation repeatedly occurs when the load is unbalanced, the second output current average value I av2 will change momentarily for a different reason and the number of times, n, imbalance has occurred may be counted, outputting an imbalance detection signal in error. The number-of-count-times setup value X is set to prevent this error from occurring.
Thus, erroneous detection caused by the effect of noise, etc., can be prevented and it is not necessary to set the threshold value of the difference current value used to detect load imbalance to a large value more than necessary; load imbalance can be detected with higher precision.
FIGS. 7 and 8 are flowcharts showing Operation 4 of the load imbalance detector 13 of the load condition detection device for the three-phase induction motor in FIG. 1. In the figure, reference numeral 501 is a step at which an elapsed time counter t, the number of times, n, imbalance has occurred and preceding difference current I sua are cleared to 0, numeral 502 is a step at which averaging time T1, a threshold value I th , and a setup value, X, of the number of count times are read from the input section 9, numeral 503 is a Step at which the elapsed time from detection start is set, numeral 504 is a step at which the d-axis current and q-axis current from the current converter 11 are read, numeral 505 is a step at which an output current instantaneous value is calculated, numeral 506 is a step at which an output current average value is calculated, numeral 507 is a step at which whether or not the time elapsed is equal to or greater than the averaging time T1 is determined, numeral 508 is a step at which the difference current between the output current instantaneous value and the output current average value, I sub is calculated, numeral 509 is a step at which the absolute value I ab of the difference current I sub is calculated, numeral 510 is a step at which whether or not I ab is greater than the threshold value I th is determined, numeral 511 is a step at which whether or not the difference current I sub is positive is determined, numeral 512 is a step at which whether or not the preceding difference current I sua is negative is determined, numeral 513 is a step at which whether or not the preceding difference current I sua is positive is determined, numeral 514 is a step at which 1 is added to the number of times, n, imbalance has occurred, numeral 515 is a step at which the difference current I sub is set as the preceding difference current I sua , numeral 516 is a step at which whether or not the number of times, n, imbalance has occurred is greater than the setup value, X, of the number of count times is determined, and numeral 517 is a step at which an imbalance detection signal is output.
FIG. 9 is a current waveform diagram showing Operation 4 of the load imbalance detector 13 of the load condition detection device for the three-phase induction motor in FIG. 1.
The operation of this embodiment will now be discussed.
At step 501, the elapsed time counter t, the number of times, n, imbalance has occurred and the preceding difference current I sua are cleared to 0 as an initial reset. The preceding difference current I sua is the value of difference current exceeding the preceding threshold value I th when the same imbalance is detected. At step 502, the averaging time T1 sufficiently longer than the period of output frequency at constant-speed time, threshold value I th , and setup value, X, of the number of count times set through the input section 9 are read. At step 503, the elapsed time is set in the counter t. At step 504, the d-axis current I d and q-axis current I q are read from the current converter 11. At step 505, an output current instantaneous value I 0UT is calculated. Next, at step 506, an average value of output current until t-T1 before the averaging time T1 from the elapsed time t is calculated. The output current average value I av is updated each time the elapsed time t has elapsed. At step 507, whether or not the elapsed time is equal to or greater than the averaging time T1 is determined for judging that calculation of the first output current average value I av is complete. If the elapsed time t is less than the averaging time T1, calculation of the first output current average value I av is not complete. Then, control returns to step 503. If t>T1, calculation of the first output current average value I av is complete. Then, control goes to step 508 at which the output current average value I av is subtracted from the output current instantaneous value I 0UT to find the difference current I sub . At step 509, the absolute value I ab of the difference current I sub is calculated. At step 510, the threshold value I th read at step 502 is compared with the absolute value of the difference, I ab .
If I ab ≦I th at step 510, the load is judged to be balanced, and control returns to step 503; if I ab >I th , control goes to step 511 at which whether or not the difference current I sub determined at step 509 is positive is determined. If the difference current I sub is positive, control goes to step 512 at which whether or not the preceding difference current with I ab >I th , I sua , is negative is determined. If the preceding difference current I sua is negative at step 512, the load is judged to be unbalanced and 1 is added to the number of times, n, imbalance has occurred at step 514, and the present difference current I sub is set as the preceding difference current I sua at step 515. If the preceding difference current I sua is positive at step 512, step 514 is skipped, and the present difference current I sub is set as the preceding difference current I sua at step 515. On the other hand, if the difference current I sub is not positive at step 511, control goes to step 513 at which whether or not the preceding difference current with I ab >I th , I sua , is positive is determined. If the preceding difference current I sua is positive at step 513, the load is judged to be unbalanced and 1 is added to the number of times, n, imbalance has occurred at step 514, and the present difference current I sub is set as the preceding difference current I sua at step 515. If the preceding difference current I sua is negative at step 512, step 514 is skipped, and the present difference current I sub is set as the preceding difference current I sua at step 515. Steps 511 to 515 are intended to count the time when the upper limit (I ab >I th with I sub >0) and the lower limit (I ab >I th with I sub <0) are exceeded alternately as the number of imbalance occurrence times by giving attention to the fact that load imbalance causes big and small waves to appear in the output current.
At step 516, whether or not the number of times, n, imbalance has occurred is greater than the setup value, X, of the number of count times read at step 502 is determined. If n>X, the load is judged to be unbalanced and an imbalance detection signal is output at step 517. If n>X, control returns to step 503.
Thus, by detecting large and small waves of output current occurring when load imbalance occurs, it is not necessary to set the threshold value of the difference current value used to detect load imbalance to a large value more than necessary; load imbalance can be detected with higher precision.
FIG. 10 is a flowchart showing Operation 5 of the load imbalance detector 13 of the load condition detection device for the three-phase induction motor in FIG. 1. In the figure, reference numeral 601 is a step at which an elapsed time counter t, a second elapsed counter t2, and the number of times, n, imbalance has occurred are cleared to 0, numeral 602 is a step at which averaging time T1, a threshold value I th , a setup value, X, of the number of count times and the number-of-count-times clear time Tc are read from the input section 9, numeral 603 is a step at which the elapsed time from detection start is set and the second elapsed time t2 are also set, numeral 604 is a step at which the d-axis current and q-axis current from the current converter 11 are read, numeral 605 is a step at which an output current instantaneous value is calculated, numeral 606 is a step at which an output current average value is calculated, numeral 607 is a step at which whether or not the time elapsed is equal to or greater than the averaging time T1 is determined, numeral 608 is a step at which whether the second elapsed time t2 exceeds the number-of-count-times clear time Tc or not is determined, numeral 609 is a step at which the second elapsed time t2 and the number of times, n, imbalance has occurred, are cleared to 0, numeral 610 is a step at which the absolute value of the difference between the output current instantaneous value and the output current average value, I ab , is calculated, numeral 611 is a step at which whether or not I ab is greater than the threshold value I th is determined, numeral 612 is a step at which 1 is added to the number of times, n, imbalance has occurred numeral 613 is a step at which whether or not the number of times, n, imbalance has occurred is greater than the setup value, X, of the number of count times is determined, and numeral 614 is a step at which an imbalance detection signal is output.
The operation of this embodiment will now be discussed.
At step 601, the elapsed time counter t, the second elapsed time counter t2, and the number of times, n, imbalance has occurred are cleared to 0 as an initial reset. At step 602, the averaging time T1 sufficiently longer than the period of output frequency at constant-speed time, threshold value I th , setup value, X, of the number of count times and the number-of-count-times clear time Tc set through the input section 9 are read. At step 603, the elapsed time from the detection start is set and the time from the 0 clear is also set in the second elapsed time t2. At step 604, the d-axis current I d and q-axis current I q are read from the current converter 11. At step 605, an instantaneous output current value I 0UT is calculated.
Next, at step 606, an average value of output current until t-T1 before the averaging time T1 from the elapsed time t is calculated. The output current average value I av is updated each time the elapsed time t has elapsed. At step 607, whether or not the elapsed time is equal to or greater than the averaging time T1 is determined for judging that calculation of the first output current average value I av is complete. If the elapsed time t is less than the averaging time T1, calculation of the first output current average value I av is not complete. Then, control returns to step 603.
If t>T1, calculation of the first output current average value I av is complete. Then, control goes to step 608 at which whether the second elapsed time t2 exceeds the number-of-count-times clear time Tc or not is determined. If the former exceeds the latter, the second elapsed time t2 and the number of times, n, imbalance has occurred are cleared to 0 at step 609 and control returns to step 603. If t2 does not exceed Tc, control goes to step 610. The number-of-count-times clear time Tc is set longer than the averaging time T1.
The reason why the number of times, n, imbalance has occurred is cleared to 0 according to the time is as follows: Since instantaneous change of output current repeatedly occurs in a load imbalanced condition, imbalance occurs more than the number of times set in the number-of-count-times setup value X within the number-of-count-times clear time Tc. Therefore, the number of imbalance occurrence times, n, is cleared to 0 each time the time has elapsed, and if the number of imbalance occurrence times, n, is small, it is handled as erroneous detection.
At step 610, the absolute value I ab of the difference between the output current instantaneous value I 0UT and the output current average value I av is calculated. At step 611, the threshold value I th read at step 602 is compared with the absolute value of the difference, I ab . When I ab >I th at step 611, 1 is added to the number of times, n, imbalance has occurred at step 612. If I ab ≦I th , the load is judged to be balanced, and control returns to step 603. At step 613, whether or not the number of times, n, imbalance has occurred is greater than the setup value, X, of the number of count times read at step 602 is determined. If n>X, the load is judged to be unbalanced and an imbalance detection signal is output at step 614. If n≦X, control returns to step 603. Thus, a predetermined time for counting the number of times is set and the number of occurrence times is cleared to 0 every predetermined time and if the number of imbalance occurrence times, n, is small, it is handled as erroneous detection, whereby load imbalance is not detected more than necessary and therefore load of the three-phase induction .motor can be run efficiently.
FIG. 11 is a block diagram showing a load condition detection device for a three-phase induction motor according to a sixth embodiment of the invention. Elements the same as those previously described with reference to FIG. 1 are denoted by the same reference numerals in FIG. 11 and will not be discussed again. In this drawing, reference numeral 15 is detection execution signal input device which is turned on and off from an external input for starting and terminating load imbalance detection.
FIG. 12 is a flowchart showing the operation of the load imbalance detector 13 in FIG. 11. In the figure, reference numeral 801 is a step at which an elapsed time counter t and the number of times, n, imbalance has occurred are cleared to 0, numeral 802 is a step at which averaging time T1, a threshold value I th , and a setup value, X, of the number of count times are read from an input section 9, numeral 803 is a step at which whether or not imbalance detection start input by the detection execution signal input means 15 is on is determined, numeral 804 is a step at which the elapsed time from detection start is set, numeral 805 is a step at which the d-axis current and q-axis current from current converter 11 are read, numeral 806 is a step at which an output current instantaneous value is calculated, numeral 807 is a step at which an output current average value is calculated, numeral 808 is a step at which whether or not the time elapsed is equal to or greater than the averaging time T1 is determined, numeral 809 is a step at which the absolute value of the difference between the output current instantaneous value and the output current average value, I ab , is calculated, numeral 810 is a step at which whether or not I ab is greater than the threshold value I th is determined, numeral 811 is a step at which 1 is added to the number of times, n, imbalance has occurred, numeral 812 is a step at which whether or not the number of times, n, imbalance has occurred is greater than the setup value, X, of the number of count times is determined, numeral 813 is a step at which whether or not imbalance detection start input by the detection execution signal input means 15 is on is determined, and numeral 814 is a step at which an imbalance detection signal is output.
The operation of this embodiment will now be discussed. In FIG. 11, when the detection execution signal input device 15 is on, an inverter 51 detects imbalance of the load of a three-phase induction motor 6 by the load imbalance detector 13 and outputs a signal by an output section 14. When the detection execution signal input device 15 is off, the inverter 51 terminates detection at the load imbalance detector 13. For example assume that when the load is a drum of a fully automatic washing machine, detection is required only in spin-drying and not required in washing or rinsing. If sequence control is performed in which the washing machine stops when an imbalance detection signal is output, it is disadvantageous to output an imbalance detection signal in error in washing or rinsing. Thus, the detection execution signal input device 15 is turned off so as not to detect imbalance. The operation of the imbalance detector 13 is discussed with reference to a flowchart of FIG. 12.
At step 801, the elapsed time counter t and the number of times, n, imbalance has occurred are cleared to 0 as an initial reset. At step 802, the averaging time T1 sufficiently longer than the period of output frequency at constant-speed time, threshold value I th , and setup value, X, of the number of count times set through the input section 9 are read. At step 803, whether or not the detection execution signal input means 15 is on is determined. If it is off, no detection operation is performed and control returns to step 801. If the detection execution signal input means 15 is on, the elapsed time is set in the counter t at step 804. At step 805, the d-axis current I d and q-axis current I q are read from the current converter 11. At step 806, an output current instantaneous value I 0UT is calculated. Next, at step 807, an average value of output current until t-T1 before the averaging time T1 from the elapsed time t is calculated. The output current average value I av is updated each time the elapsed time t has elapsed. At step 808, whether or not the elapsed time is equal to or greater than the averaging time T1 is determined for judging that calculation of the first output current average value I av is complete. If the elapsed time t is less than the averaging time T1, calculation of the first output current average value I av is not complete. Then, control returns to step 803.
If t>T1, calculation of the first output current average value I av is complete. Then, control goes to step 809 at which the absolute value I ab of the difference between the output current instantaneous value I 0UT and the output current average value I av is calculated. At step 810, the threshold value I th read at step 802 is compared with the absolute value of the difference, I ab . When I ab >I th at step 810, 1 is added to the number of times, n, imbalance has occurred at step 811. If I ab ≦I th , the load is judged to be balanced, and control returns to step 803. At step 812, whether or not the number of times, n, imbalance has occurred is greater than the setup value, X, of the number of count times read at step 802 is determined. If n>X, the load is judged to be unbalanced and control goes to step 813 at which again whether or not the detection execution signal input means 15 is on is determined. If it is off, no detection operation is performed and control returns to step 801 at which the elapsed time counter t and the number of times, n, imbalance has occurred are cleared to 0. If the detection execution signal input means 15 is on, an imbalance detection signal is output at step 814. If n≦X at step 812, control returns to step 803.
Thus, imbalance of the load of the three-phase induction motor can be detected only when necessary. For example, with a washing machine, imbalance detection is executed only during spin-drying and not executed in washing or rinsing.
FIG. 13 is a block diagram showing a load condition detection device for a three-phase induction motor according to a seventh embodiment of the invention. Parts the same as those previously described with reference to FIG. 1 are denoted by the same reference numerals in FIG. 13 and will not be discussed again. Reference numeral 16 is run condition determination device for determining a run condition of an inverter from an output frequency from output frequency and voltage calculation unit 12 and a specified frequency through an input section 9 and if the inverter runs at constant speed, for sending a signal to load imbalance detector 13 at the constant-speed time.
FIG. 14 is a flowchart showing the operation of the load imbalance detector 13 in FIG. 13. In the figure, numeral 1001 is a step at which an elapsed time counter t and the number of times, n, imbalance has occurred are cleared to 0, numeral 1002 is a step at which averaging time T1, a threshold value I th , and a setup value, X, of the number of count times are read from the input section 9, numeral 1003 is a step at which whether or not the inverter is running at constant speed is determined, numeral 1004 is a step at which the elapsed time from detection start is set, numeral 1005 is a step at which the d-axis current and q-axis current from current converter 11 are read, numeral 1006 is a step at which an output current instantaneous value is calculated, numeral 1007 is a step at which an output current average value is calculated, numeral 1008 is a step at which whether or not the time elapsed is equal to or greater than the averaging time T1 is determined, numeral 1009 is a step at which the absolute value of the difference between the output current instantaneous value and the output current average value, I ab , is calculated, numeral 1010 is a step at which whether or not I ab is greater than the threshold value I th is determined, numeral 1011 is a step at which 1 is added to the number of times, n, imbalance has occurred numeral, 1012 is a step at which whether or not the number of times, n, imbalance has occurred is greater than the setup value, X, of the number of count times is determined, numeral 1013 is a step at which whether or not the inverter is running at constant speed, and numeral 1014 is a step at which an imbalance detection signal is output.
FIG. 15 is a current waveform diagram for explaining operation of the load unbalance detecting device 13 of FIG. 13.
The operation of this embodiment will now be discussed. In FIG. 13, when the output frequency from the output frequency and voltage calculation unit 12 matches the specified frequency through the input section 9 at the run condition determination device 16, the device 16 determines that the inverter runs at constant speed, and sends a signal indicating that the inverter is running at constant speed to the load imbalance detector 13, which then starts detecting imbalance of a load of a three-phase induction motor 6. Upon detection of load imbalance, the load imbalance detector 13 outputs a load imbalance detection signal from the output section 14. When the output frequency from the output frequency and voltage calculation unit 12 does not match the specified frequency through the input section 9 at the run condition determination device 16, the device 16 determines that the inverter is in acceleration or deceleration, and the load imbalance detector 13 does not operate.
The operation of the imbalance detector 13 is discussed with reference to a flowchart of FIG. 14. At step 1001, the elapsed time counter t and the number of times, n, imbalance has occurred are cleared to 0 as an initial reset. At step 1002, the averaging time T1 sufficiently longer than the period of output frequency at constant-speed time, threshold value I th , and setup value, X, of the number of count times set through the input section 9 are read. At step 1003, whether or not the inverter is running at constant speed is determined depending on the presence or absence of a signal from the run condition determination device 16. No detection operation is performed in the absence of the signal. Then, control returns to step 1001. If the signal from the run condition determination device 16 exists, the elapsed time is set in the counter t at step 1004. At step 1005, the d-axis current I d and q-axis current I q are read from the current converter 11. At step 1006, an output current instantaneous value I 0UT is calculated. Next, at step 1007, an average value of output current until t-T1 before the averaging time T1 from the elapsed time t is calculated. The output current average value I av is updated each time the elapsed time t has elapsed. At step 1008, whether or not the elapsed time is equal to or greater than the averaging time T1 is determined for judging that calculation of the first output current average value I av is complete. If the elapsed time t is less than the averaging time T1, calculation of the first output current average value I av is not complete. Then, control returns to step 1003. If t>T1 calculation of the first output current average value I av is complete. Then, control goes to step 1009 at which the absolute value I ab of the difference between the output current instantaneous value I 0UT and the output current average value I av is calculated. At step 1010, the threshold value I th read at step 1002 is compared with the absolute value of the difference, I ab .
When I ab >I th at step 1010, 1 is added to the number of times, n, imbalance has occurred at step 1011. If I ab ≦I th , the load is judged to be balanced, and control returns to step 1003. At step 1012, whether or not the number of times, n, imbalance has occurred is greater than the setup value, X, of the number of count times read at step 1002 is determined. If n>X, the load is judged to be unbalanced and control goes to step 1013 at which again whether or not the inverter is running at constant speed is determined depending on the presence or absence of a signal from the run condition determination device 16. No detection operation is performed in th absence of the signal. Then, control returns to step 1001 at which the elapsed time counter t and the number of times, n, imbalance has occurred are cleared to 0. If the signal from the run condition determination device 16 exists, an imbalance detection signal is output at step 1014. If n≦X at step 1012, control returns to step 1003.
Thus, even if load imbalance occurs in acceleration or deceleration in FIG. 15, no detection operation is performed, so that load running will not stop unnecessarily. For example, torque imbalance in running at constant steed is only detected and transient torque imbalance in acceleration or deceleration is not detected.
FIG. 16 is a block diagram showing a load condition detection device for a three-phase induction motor according to an eighth embodiment of the invention. Parts the same as those previously described with reference to FIG. 1 are denoted by the same reference numerals in FIG. 16 and will not be discussed again. When load imbalance is detected, an inverter stop signal is sent from the load imbalance detector 13 to the output frequency and voltage calculation unit 12, and the inverter 51 decelerates and stops a three-phase induction motor 8. This eliminates the need for programming an external sequence in sequence control for stopping a washing machine when an imbalance detection signal is output.
When load imbalance occurs, automatically the motor is decelerated and stopped in response to the stop signal from the load imbalance detector. Thus, load imbalance is prevented from causing damage to the machine. For example, the motor shaft of the three-phase induction motor will not be damaged or eccentricity will not cause the load to strike against a wall, damaging the machine; an external sequence for preventing damage is not required either.
FIG. 17 is a block diagram showing an embodiment of applying the load condition detection device to a single-phase induction motor, wherein reference numeral 20 is a single-phase AC power supply, numeral 21 is a converter section of inverter, numeral 3 is a smoothing capacitor of the inverter, numeral 22 is an inverter section of the inverter, numeral 23 is current detector of the inverter, numeral 24 a single-phase induction motor, numeral 25 is a load of the single-phase induction motor, numeral 26 is a control section of the inverter, numeral 9 is an input section of the inverter for inputting a run command setup value, numeral 27 is electric current converter for converting a two-phase current detected by the two-phase current detector 23 into a current in the d-q axis rotating in synchronization with an output frequency and determining a d-axis current, an excitation phase current in vector control and a q-axis current, a torque phase current, numeral 12 is an output frequency and voltage calculation unit for calculating an output frequency and an output voltage from the setup value from the input section 9 and the d-axis current and q-axis current from the current converter 27, numeral 13 is load imbalance detector for detecting current fluctuation occurring secondarily as a result of load imbalance from the d-axis current and q-axis current from the current converter 27, numeral 14 is an output section for outputting a signal to the outside upon detection of load imbalance, and numeral 5 is the entire inverter.
The imbalance detection signal in the first to ninth embodiments may be output as an electric signal such as open collector, relay output, audio output such as a buzzer, or optical output such as LED, for example.
Since the three-phase current sum is 0 in the first to eighth embodiments, if two phases are determined, the remaining phase can be calculated. Therefore, only two of the three phases need be detected for current detection.
Further, a value input to the setting device in the first to eighth embodiments can be changed as desired from the external for changing the level of load imbalance to be detected.
In the first to eighth embodiments, use of an inverter has been discussed, but the invention is applicable to other variable-frequency, variable-voltage output devices, needless to say.
Although use of the d and q axes has been discussed in the description of load detection of the three-phase induction motor in the first to eighth embodiments, a motor load can be detected using only the q axis as discussed in connection with the second embodiment. Therefore, other load condition detection devices can be employed by replacing the control sections of the inverters in the third to eighth embodiments with the control section of the inverter described in the second embodiment.
A description has been given taking the load imbalance detection device for a three-phase induction motor driven by the inverter as an example, but the variable-frequency, variable-voltage application power supply is not limited to the inverter. The description concerning the three-phase induction motor is also applied to other induction motors.
Thus, according to the invention, the load condition detection device for an induction motor effecting rotation of a load when a predetermined current is input comprises a current detector for detecting a current instantaneous value of the current, average current detection means for determining a current average value based on the current instantaneous value and a predetermined average time, current value comparison means for determining a difference between the current instantaneous value and the current average value, counting means for comparing the value obtained by the current value comparison means with a first predetermined value and counting the number of times the obtained value has exceeded the predetermined value, and means for stopping the rotation of the load if the value counted by the counting means within a predetermined time exceeds a second predetermined value, whereby load imbalance is prevented from causing mechanical damage to the device and is detected electrically. Therefore, there is provided a load condition detection device for an induction motor which enables easy change of load imbalance detection level and has detection precision not changing with time at low costs.
The load condition detection device for an induction motor effecting rotation of a load when a predetermined current is input comprises a current detection means for detecting a current instantaneous value, average current detection means for determining a current average value based on the current instantaneous value and a predetermined average time, current value comparison means for determining a difference between the current instantaneous value and the current average value, counting means for comparing the value obtained by the current value comparison means with a first predetermined value and counting the number of times the obtained value has exceeded the predetermined value, and alarm means for informing the user that the load is in an imbalanced condition, whereby load imbalance is prevented from causing mechanical damage to the device and is detected electrically. Therefore, there is provided a load condition detection device for an induction motor which enables easy change of load imbalance detection level and has detection precision not changing with time at low costs.
The instantaneous value of a current for the load is detected, a current average value of the current instantaneous values for a predetermined average time thereof is determined, an absolute value of a difference between the current instantaneous value and the current average value is determined, the number of times the absolute value exceeds a predetermined value is detected, and a load condition detection signal is output in response to the detection value, thereby detecting load imbalance electrically. Therefore, there is provided an induction motor load condition detection method which enables easy change of load imbalance detection level and has detection precision not changing with time at low cost.
A current instantaneous value of q-axis current into which a current for a load is converted by d-q axis current conversion means is detected, a q-axis current average value of the current instantaneous values for a predetermined average time thereof is determined, an absolute value of a difference between the q-axis current instantaneous value and the q-axis current average value is determined, the number of times the absolute value exceeds a predetermined value is detected, and a load condition detection signal is output in response to the detection value, thereby stably and easily detecting load imbalance with high accuracy only with the q-axis current instantaneous value without using the d-axis current instantaneous value.
A current instantaneous value of an input current for a load is detected, a first current average value for a first predetermined average time sufficiently short as compared with a load period of the current instantaneous values and a second current average value for a second predetermined average time sufficiently long as compared with the load period are determined, an absolute value of a difference between the first and second output current average values is determined, the number of times the absolute value exceeds a predetermined value is detected, and a load condition detection signal is output in response to the detection value, thereby preventing the effect of noise, etc., from causing erroneous detection and eliminating the need for setting a large threshold value of difference current value for detecting load imbalance more than necessary. Therefore, load imbalance can be detected with higher accuracy.
A current instantaneous value of a current for a load is detected, a current average value of the current instantaneous values for a predetermined average time thereof is determined, an absolute value of a difference between the current instantaneous value and the current average value is determined, the number of times a case occurs where the absolute value exceeds a predetermined value and differs in polarity from the preceding difference current exceeding the predetermined value is determined, and a load condition detection signal is output in response to the detection value, thereby eliminating the need for setting a large threshold value of difference current value for detecting load imbalance more than necessary. Therefore, load imbalance can be detected with higher accuracy.
The number of times the absolute value exceeds the predetermined value is detected every predetermined time, and only when the predetermined number of times is exceeded within predetermined time, the load condition detection signal is output. If the number of times imbalance has occurred is small, it is handled as erroneous detection, whereby load imbalance is not detected more than necessary. Therefore, induction motor load running can be performed efficiently.
The load condition detection signal can be output, only when necessary, by load condition detection start and end signals.
A specified frequency is compared with an output frequency for determining whether or not running at constant speed is being performed, and if it is determined that running at constant speed is being performed, the load condition detection operation is started by a signal indicating running at constant speed. Therefore, even if load imbalance occurs during accelerating or decelerating, the load condition detection operation is not performed, so that load running is not stopped unnecessarily. | A method and device for detecting an out-of-balance condition of a load which is driven by a motor is disclosed. A present instantaneous value of a current of a motor which is driving a load is detected and an average value of the detected instantaneous value over time is established. The present instantaneous value is compared to the established average value, and the number of times which the instantaneous value differs from the average value by at least a prescribed amount is counted. If this number exceeds a certain number, it is determined that the load which the motor is driving is out of balance. | 3 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present application is a continuation-in-part application of U.S. patent application Ser. No. 11/919,655, filed Oct. 31, 2007, disclosure of which is incorporated herein by reference. This patent application claims the benefit under 35 USC 119 (e) of U.S. Provisional Patent Application No. 60/932,586, filed Jun. 1, 2007.
FIELD OF THE INVENTION
[0002] The present invention is related to a technique for forming a hardened orthopaedic paste in a bone by inserting a perforated balloon in the bone, injecting an orthopaedic paste into said balloon, which will harden in-situ, and rupturing the balloon to leave the hardened paste in the bone, acting as a medical implant. The orthopaedic paste can be any known flowable orthopaedic filling material including, for example, a liquid-powder mixture and a viscous liquid containing a polymeric material.
BACKGROUND OF THE INVENTION
[0003] It is well accepted that bioresorbable orthopedic implants are always the better choice than permanent foreign-body implants, as long as their bioresorption rates, biomechanical properties and variations in biomechanical properties with respect to the resorption processes are appropriately controlled. Among all bioresorbable orthopedic implants, calcium-based implants (calcium phosphate, calcium sulfate, etc), are perhaps the top choice so far.
[0004] For the purpose of filling a bone cavity, especially an irregularly-shaped bone cavity, a bone cement paste (for example, a PMMA, calcium phosphate cement or calcium sulfate cement) is often injected into the cavity, wherein the bone cement paste is hardened in-situ. This hardened cement will remain in bone as a permanent implant if it is a permanent foreign-body implant such as PMMA, or gradually replaced by natural bone if it is a bioresorbable material such as calcium phosphate or calcium sulfate. For load-bearing applications, this hardened cement should provide a sufficient strength to withstand the post-operation routine loadings.
[0005] Most conventional methods of forming a hardened (set) bone cement in bone cavity involve creating a bone cavity, followed by directly injecting a cement paste into the bone cavity. Such an approach suffers the following major drawbacks among others:
(1) Since the cement paste is directly injected into an environment filled with blood/body fluid, the cement particles are easily dispersed in this environment, especially before the paste is fully set. The dispersed cement particles can penetrate into surrounding tissues, cracks, blood vessels, nerve system, etc. and cause various kinds of clinical complications such as potentially fatal cement embolism. (2) Since the cement paste is hardened in blood/body fluid, the predetermined liquid/powder ratio, which is critical to cement properties, is disrupted in-situ, causing the performance/properties of the cement to degrade. Although applying pressure to the cement during its hardening process can improve the cement strength, surgeons usually avoid applying a high pressure directly to the injected cement paste due to the above-mentioned potential risks of complications. (3) Besides the disruption in liquid/powder ratio, the irregular shape of the hardened cement also decreases the biomechanical properties of the cement and increases the uncertainty/risks of the cement performance (depending on the actual shape and filling condition), especially for bioceramic cements such as calcium phosphate cement and calcium sulfate cement. The decreased strength further causes the cement to more easily disperse/disintegrate.
[0009] Another approach to inject an orthopedic implant into a bone cavity involves inserting a container (balloon or pocket) into the cavity; injecting a bone filler (not necessarily a hardenable cement paste) into the container through a tube; and separating the container from the tube with the container and its contained bone filler remaining in bone. One major problem with this approach is that the container left in bone becomes a permanent foreign body which prevents the bone filler from directly interacting with bone tissue to form a biological or even only a chemical or physical bond between the bone filler and bone. Furthermore, most popularly-used containers (balloons) are made from polymers which are not bioactive, bioconductive, or even biocompatible. The negative effects of this permanently implanted container are most obvious when the bone filler is a bioresorbable material, such as a calcium phosphate or calcium sulfate-based material. In this case even a biodegradable polymer container hinders the bioresorption process of the bioresorbable bone filler for a season, especially during the most critical early stage resorption/healing process. Furthermore, most biodegradable polymers do not demonstrate mechanical properties as desired.
[0010] An improved method for forming a hardened cement in a bone cavity involves inserting an inflatable, preferably inflatable and expandable, pocket into a bone being treated; injecting a hardenable cement paste into the pocket through a tube which connects and carries the pocket into the bone; allowing the cement paste to harden within the pocket in the bone cavity; opening the pocket; separating the pocket from the hardened cement, and retrieving the opened pocket from the bone with the hardened cement remaining in the bone. Advantages of this method include allowing the hardened cement implant to directly contact the surrounding bone tissue thus enhancing the healing process, and the much higher strength of the hardened cement compared to that of the cement paste directly injected into the bone cavity. This is especially advantageous for bioresorbable implants. A typical example can be found in U.S. Pat. No. 7,306,610 B2.
[0011] A further improved method for forming a hardened cement in a bone cavity involves inserting an inflatable, preferably inflatable and expandable, pocket into a bone being treated; injecting a hardenable cement paste into the pocket through a tube which connects and carries the pocket into the bone, therein said pocket is made from a material penetrable to liquid but substantially impenetrable to the powder of said cement paste; allowing the cement paste to harden within the pocket in the bone cavity; opening the pocket; separating the pocket from the hardened cement, and retrieving the opened pocket from the bone with the hardened cement remaining in the bone. A primary advantage of this method is allowing a portion of the liquid contained in the cement paste to be expelled out of the pocket, especially when a pressure is applied unto said cement paste before said cement paste is substantially hardened, so that the powder/liquid ratio of said cement paste in said pocket is increased and the strength of the hardened cement is further increased. This further increase in cement strength is especially advantageous for the relatively weak ceramic, calcium-based cement. A typical example can be found in U.S. Pat. No. 7,144,398 B2. Nevertheless, one major difficulty in practicing this method is the accurate control of the selective penetrability (only to liquid) of the pocket, especially during the expansion process, wherein the volume of the pocket continues to increase while the thickness of the pocket continues to decrease.
SUMMARY OF THE INVENTION
[0012] The present invention further improves the existing methods for forming a hardened cement in a bone cavity by disclosing an inflatable and expandable balloon with a designed perforation pattern through the membrane of said balloon, wherein the perforation pattern (perforation size, population, and distribution, etc) can be designed and controlled so that the balloon is penetrable to liquid but substantially impenetrable to the powder of the cement paste under an expanded condition. The present invention further discloses a “forced-feeding” method for opening (rupturing) a balloon after its contained cement paste is substantially hardened. A brief description of the present inventive method and device is given below.
THE METHOD
[0013] 1. A method for treating a bone comprising
(a) preparing a cement paste from a powder and a liquid, so that said cement paste is injectable through a syringe; (b) inserting a perforated balloon into said bone, therein said perforated balloon comprising at least one perforation through the membrane of said balloon; therein the size of said perforation can be controlled so that the balloon is penetrable to liquid but substantially impenetrable to the powder of said cement paste under expanded condition; (c) injecting said cement paste into said perforated balloon, wherein said injecting is carried out with a means which is able to be operated outside said bone cavity; (d) applying a pressure unto said cement paste before said cement paste is substantially hardened, causing a portion of said liquid contained in said cement paste to be expelled out of said perforated balloon, so that the powder/liquid ratio of said cement paste in said perforated balloon is increased; (e) allowing said cement paste at least partially harden in said balloon; (f) rupturing said balloon, wherein said rupturing is carried out with a means which is able to be operated outside said bone cavity, and the resulting ruptured balloon is attached to said means; (g) separating the resulting ruptured balloon from the hardened cement, wherein said separating is carried out by removing the resulting ruptured balloon from said bone cavity with the hardened cement remaining in said bone cavity.
[0021] 2. The method in (1) further comprising preparing a minimally invasively percutaneous path for the balloon to be inserted into the bone being treated.
[0022] 3. The method in (2) further comprising inserting an injection tube into the bone through said percutaneous path, wherein the balloon is connected to or near distal end of said injection tube; through said tube the cement paste is injected into the balloon, wherein the balloon is dilated by the injection of said paste.
[0023] 4. The perforated balloon in (1b) further comprising multiple perforations through the membrane of said balloon; wherein said multiple perforations comprise a first type of perforations capable of functioning as channels through which a portion of the liquid contained in the cement paste inside the expanded balloon can be expelled out of the balloon.
[0024] 5. The perforated balloon in (1b) further comprising multiple perforations through the membrane of said balloon; wherein said multiple perforations comprise a second type of perforations designed for being able to function as weak spots, wherein said rupturing in (1f) can preferentially occur at or along said predetermined (designed) weak spots.
[0025] 6. Said second type of perforations in (5) further comprising at least one perforation array (a “dotted line” of perforations), preferably located at the opposite side to the neck of the balloon (the leading/top portion of the balloon), wherein the rupturing of the balloon can preferentially occur at or along said weak spots when the balloon is dilated and is subjected to an interior or exterior force. Optionally said second type of perforations comprise multiple perforation arrays, preferably located at the opposite side to the neck of the balloon, comprising designed patterns of pores, dents, notches, grooves, cuts, etc. made on the surface of at least a portion of the balloon. Preferably the perforation arrays converge around the apex of the balloon, creating a most weakened area where rupturing cracks would initiate.
[0026] 7. The first type of perforations in (4) and second type of perforations in (5) and (6) are optionally the same perforations, wherein said same perforations are designed to function as both channels through which a portion of the liquid contained in the cement paste inside the balloon can be expelled out of the balloon under expanded condition, and as weak spots wherein said rupturing in (1f) can preferentially occur at or along said weak spots.
[0027] 8. Said rupturing in (1f), (5)-(7) is assisted by means of a forced-feeding mechanism, wherein said forced-feeding is characterized by, after said cement paste is substantially hardened, further injecting a biocompatible fluid (water, oil, etc) into the balloon at a flow rate greater than that of the fluid leaking out of the balloon through the perforations to cause said balloon to swell until it ruptures.
[0028] 9. Said rupturing in (1f), (5)-(7) is assisted by means of a cutting mechanism, wherein said cutting is conducted unto at least a portion of said balloon, preferably located at the opposite side to the neck of the balloon with a cutting means, for example, a thin wire or blade.
[0029] 10. Said rupturing in (1f), (5)-(7) is assisted by means of a thermal softening/melting mechanism, wherein said thermal softening/melting is conducted with an energy directed by an electrically, thermally or optically conductive wire embedded in at least a portion of said balloon, preferably located at the opposite side to the neck of the balloon.
[0030] 11. The method in (1) further comprising, prior to inserting a balloon into the bone, creating a cavity and/or restoring at least a portion of height of the bone being treated, wherein the volume of the first bone filler injected into the balloon can be controlled to either avoid further expanding the bone, or to further expand the bone.
[0031] 12. The balloon is preferably made from an inflatable, preferably inflatable and expandable, polymeric material (PU, rubber, etc), although any other material in any form (fabric, mesh, etc) which may serve the purpose may be used.
[0032] 13. The sizes of the perforations in (1), (4)-(7) are substantially less than the particle size of the powder in the cement paste so that liquid can be squeezed out but cement powder cannot penetrate through the perforations. Preferably the perforation sizes are less than 10 microns, and more preferably less than 1 micron.
[0033] 14. Said powder in said cement paste in (1a) is made from a biocompatible material, preferably a biocompatible and bioconductive material, more preferably a biocompatible, bioconductive and bioresorbable material.
[0034] 15. Optionally a wire or thread can be connected to any part of the balloon, preferably at the opposite side to the neck of the balloon, as a safety device, wherein, in case a portion (piece) of the ruptured balloon is broken off, the broken-off portion can be retrieved by the connected wire/thread independently.
[0035] 16. The bone being treated is preferably a diseased or fractured vertebral body.
THE DEVICE
[0036] A. A perforated balloon for entrapping a cement paste for treating a bone until the paste is hardened inside the balloon in a bone cavity; wherein the perforated balloon is adapted to be mounted on an end of an injection tube of a cement paste delivering tool through which the paste is injected into the balloon and the balloon is dilated by the injection of the cement paste; wherein said perforated balloon comprising at least one perforation through the membrane of said balloon; wherein the size of said perforation can be controlled so that the balloon is penetrable to liquid but substantially impenetrable to the powder of said cement paste under expanded condition.
[0037] B. The perforated balloon in (A) further comprising multiple perforations through the membrane of said balloon; wherein said multiple perforations comprise a first type of perforations capable of functioning as channels through which a portion of the liquid contained in the cement paste inside the expanded balloon can be expelled out of the balloon.
[0038] C. The perforated balloon in (A) further comprising multiple perforations through the membrane of said balloon; wherein said multiple perforations comprise a second type of perforations designed for being able to function as weak spots, wherein said rupturing of the balloon can preferentially occur at or along said predetermined (designed) weak spots.
[0039] D. The second type of perforations in (C) further comprising at least one perforation array (a “dotted line” of perforations), preferably located at the opposite side to the neck of the balloon (the leading/top portion of the balloon), wherein said rupturing of the balloon can preferentially occur at or along said weak spots when the balloon is dilated and is subjected to an interior or exterior force. Optionally said second type of perforations comprise multiple perforation arrays, preferably located at the opposite side to the neck of the balloon, comprising designed patterns of pores, dents, notches, grooves, cuts, etc. made on the surface of at least a portion of the balloon. Preferably the perforation arrays converge around the apex of the balloon, creating a most weakened area where rupturing cracks would initiate.
[0040] E. The first type of perforations in (B) and second type of perforations in (C) and (D) are optionally the same perforations, wherein said same perforations are designed to function as both channels through which a portion of the liquid contained in the cement paste inside the balloon can be expelled out of the expanded balloon, and as weak spots wherein said rupturing of the balloon can preferentially occur at or along said weak spots.
[0041] F. Said rupturing of the balloon in (C)-(E) is assisted by a forced-feeding mechanism, wherein said forced-feeding is characterized by, after said cement paste is substantially hardened, further injecting a biocompatible fluid (water, oil, etc) into the balloon at a flow rate greater than that of the fluid leaking out of the balloon through the perforations to cause said balloon to swell until it ruptures.
[0042] G. Said rupturing of the balloon in (C)-(E) is assisted by pulling or twisting the injection tube while pushing the substantially hardened cement by inserting a stylet into the tube while holding the tube after the cement paste is substantially hardened inside the balloon.
[0043] H. Said rupturing of the balloon in (C)-(E) is assisted by a cutting mechanism, therein said cutting is conducted unto at least a portion of said balloon, preferably located at the opposite side to the neck of the balloon, with a cutting means, for example, a thin wire or blade.
[0044] I. Said rupturing of the balloon in (C)-(E) is assisted by a thermal softening/melting mechanism, therein said thermal softening/melting is conducted with an energy directed by an electrically, thermally or optically conductive wire embedded in at least a portion of said balloon, preferably located at the opposite side to the neck of the balloon.
[0045] J. The sizes of the perforations in (A)-(E) are substantially less than the particle size of the powder in the cement paste so that liquid can be squeezed out but cement powder cannot penetrate through the perforations. Preferably the perforation sizes are less than 10 microns, and more preferably less than 1 micron.
[0046] K. The balloon membrane preferably has a substantially uniform thickness and a predetermined shape.
[0047] L. The balloon is preferably made from an inflatable, preferably inflatable and expandable, polymeric material (PU, rubber, etc), although any other material in any form (fabric, mesh, etc) which may serve the purpose may be used.
[0048] M. Said powder in said cement paste is made from a biocompatible material, preferably a biocompatible and bioconductive material, more preferably a biocompatible, bioconductive and bioresorbable material.
[0049] O. Said biocompatible material in (M) comprising a calcium-based compound comprising calcium phosphate, calcium sulfate, bioactive glass or their composites.
[0050] P. Said cement paste is further doped with a relatively strong and rigid biocompatible phase, such as calcium phosphate particles, calcium sulfate particles, or bioactive glass particles or their composites, for improving strength of said cement.
[0051] Q. Said cement paste is further doped with a BMP, a growth factor (e.g., a bone marrow or blood-derived growth factor), or living cells for enhancing bone resorption/healing processes.
[0052] R. Optionally a wire or thread can be connected to any part of the balloon, preferably at the opposite side to the neck of the balloon, as a safety device, wherein, in case a portion (piece) of the ruptured balloon is broken off, the broken-off portion can be retrieved by the connected wire/thread independently.
BRIEF DESCRIPTION OF THE DRAWINGS
[0053] FIG. 1 is a schematic front view of a perforated balloon for entrapping an orthopaedic paste in a bone cavity until the paste is hardened in a bone cavity disclosed in the present invention.
[0054] FIG. 2 is a schematic side view of the perforated balloon shown in FIG. 1 .
[0055] FIG. 3 is a schematic side view of a cement-filled balloon under forced-feeding by fluid.
[0056] FIG. 4 is a schematic side view showing a representative implementation of forced-feeding by connecting the balloon rear end to a syringe.
DETAILED DESCRIPTION OF THE INVENTION
[0057] As bone cement paste is delivered into a balloon made from elastic material (for example, a polymeric PU), surface tension will be created due to the stretch of the balloon membrane. The pressure differential (ΔP) across membrane is proportional to the surface tension and inversely proportional to the radius of curvature of the balloon:
[0000]
Δ
P
=
P
b
-
P
a
=
2
γ
R
(
1
)
[0000] wherein P b is the pressure inside the balloon, P a is the pressure outside the balloon, r is the diameter of the perforations, and R is the radius of curvature of the balloon. The static equilibrium between the pressure differential across the membrane and the surface tension sets an ideal stage for cement to solidify. In order to expel air or water trapped originally in the balloon before cement delivery, tiny holes/perforations were made as venting flow passages distributed in the membrane wall. These tiny holes serve two major roles for bone cement delivery, one as the air/water filter and another as the crack initiator for the subsequent balloon rupture.
[0058] In order for the balloon to be ruptured in a predetermined (designed) manner (pattern) after the cement is hardened, “perforation array” is designed, for example the perforation array 210 shown in FIGS. 1 and 2 . The perforation array 210 is used mainly to rupture the inflated balloon 200 with predetermined lines/pattern of breakup, although permeability effect is also provided therein when the pore size is carefully controlled. The perforation array is also designed to keep the entire ruptured balloon to remain attached to the injection tube end after being ruptured. Without this design, it is highly likely that some random pieces of the ruptured balloon are detached from the balloon and left permanently in the bone cavity. Ideally the entire balloon should remain attached to the injection tube after being ruptured and can be entirely withdrawn along with the tube.
[0059] The perforation array 210 comprises designed patterns of pores, dents, notches, grooves, cuts, etc. and are made on the surface of at least a portion of the balloon. Such pores, dents, notches, grooves, cuts, etc. can be made by any conventional methods. Preferably, these pores, dents, notches, grooves, cuts, etc. are made at or near the central part of the balloon. Preferably, the “lines of perforation” converge around the apex of the balloon, creating relatively weakened spots where rupturing crack would initiate.
[0060] Such parameters as pore size, population, spacing between perforations, number of perforation array, and the array size are to be controlled and optimized to result in a required structural characteristics of the balloon.
[0061] Although permeability (draining) effect is provided in the design of the perforation array, in order to more effectively drain water and air out of the balloon as the cement paste is injected to fill the bone cavity, micro-pores 220 can be further incorporated over the surface of the balloon 200 . These micro-pores can be distributed randomly or in a designed manner/pattern and will be progressively enlarged as cement mixture is continually delivered into the balloon.
[0062] The perforations of the perforation array 210 and the micro-pores 220 of desired diameters and optionally desired distribution (pattern) can be made mechanically (for example, by needle drilling), chemically (for example, by etching/dissolving) or thermally (for example, by focused heat or laser drilling). The perforations/pores can be made on an empty balloon, a balloon still attached onto a substrate mode (for example, a balloon made by dipping a balloon-shaped substrate mode of a desired size and shape in a PU solution), or a pre-expanded balloon with an infilling material.
[0063] As perforations/pores are made on a pre-expanded balloon, the infilling material can be any material which can be delivered into and expand the balloon, and removed from the balloon after perforations are made on the expanded balloon. The infilling material is preferably a high-viscosity powder-liquid mixture paste which will not set/harden in a short period of time after mixing (for example, a CaO powder/water mixture). The balloon can be pre-expanded to any desired size whereas perforations are made. One advantage for perforations/pores made on a pre-expanded balloon is its easier control in perforation quality, since the balloon surface is enlarged during expansion.
[0064] As a balloon swells to certain critical size, the internal stresses developed in the stretched membrane will reach the balloon fracture stress threshold. The corresponding strain at balloon fracture can be converted into the rupture volume of the balloon. When balloon is filled with any material which expands the balloon to this critical volume, balloon will fracture spontaneously and the fractured balloon membrane will shrink to its zero-stress state size. Balloon extraction can hence be achieved while leaving the solidified cement deployed in the designated bone cavity.
[0065] FIG. 3 shows a cement-filled balloon under forced-feeding by fluid. As the feeding pressure destroys the initial static equilibrium the solidified cement will be lifted up immediately with an inlet flow passage created around the feeding entrance, followed by a filling of the balloon due to the infused fluid volume. Any fluid, gas or liquid, can be used as the filling material so long as it is biocompatible. These fluid fillers first separate the balloon membrane from the solidified cement surface, greatly reducing the contact friction by generating a layer of fluid buffer. Then a further injection of fluid filler will expand the balloon until balloon rupture is accomplished. According to the mass conservation of fluids, the rate of mass increment contained in the balloon closure is equal to the net mass flux convected through the inflow/outflow tracts:
[0000]
ρ
V
t
=
∑
i
ρ
Q
i
in
-
∑
i
ρ
Q
i
in
(
2
)
[0000] in which, V is the volume and ρ is the density of the fluid while Q i in and Q i out are the inflow and outflow volume flowrates, respectively. For the case illustrated in FIG. 3 , Q i in is the forced-feeding influx and
[0000]
∑
i
Q
i
out
[0000] is the net outflux contributed by all the leakage flows across the micro-pores and perforations in the membrane wall. So long as the volume flux of the inflow is greater than that of the outflow, the balloon will keep on swelling until it ruptures.
[0066] FIG. 4 shows a representative implementation by connecting the balloon rear end to a fluid filler such as a syringe 100 having a fluid reservoir 110 . Any decrease of the reservoir volume by pushing the syringe 100 from behind, with sufficiently force and speed, may result in a net volume infusion into the balloon. Balloon will rupture as the accumulated fluid mass increases and the resultant membrane stresses reach the rupture threshold value.
[0067] To reduce the risk that a portion (especially the leading/top portion) of ruptured balloon (especially for rupture occurring around the belly/equator portion of the balloon) being trapped in the cavity when the ruptured balloon is retrieved from the cavity site, a thread can be connected to any part of the balloon as a safety device. Since the leading/top portion is one that most easily breaks off the balloon during rupture, the thread can be connected (for example, by glue) to such location. In case a portion of ruptured balloon is broken off, the broken-off piece can be retrieved by the connected wire/thread independently. | The present invention discloses a technique for forming a hardened orthopaedic paste in a bone cavity, which involves a forced-feeding balloon rupture mechanism. This mechanism includes continuously or intermittently injecting a liquid or gas into a perforated balloon containing a hardened orthopaedic paste therein in a bone cavity until the perforated balloon is dilated to exceed a critical size, and thus ruptures. | 0 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Patent Application No. 60/850,692 filed Oct. 10, 2006, and entitled “Insert for Use in Securing Refractory Members to Heat-Absorptive Elements,” the contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to furnace insulation systems, and more particularly, to means for securing refractory members to a heat-absorptive element in order to better protect the element from the extreme temperatures of the furnace.
[0004] 2. Description of Related Art
[0005] Furnaces for heating metals often operate at extremely high temperatures. Within these furnaces are metal structures that provide structural support. In order to maintain the integrity of these support structures, the structures are insulated from the extreme heat by external refractory members and cooled internally with circulating fluid. These refractory members are connected to the metal support structures in a multitude of ways so as to withstand the high temperatures, thermal shock, vibrations, and other forces to which these support structures are subjected. Because these refractory members must be routinely replaced, ease of installation is also of importance.
[0006] One commonly known refractory member, disclosed in U.S. Pat. No. 4,528,672, comprises a refractory shape having an interconnected, reticulated metal mesh defined by a plurality of spirals embedded within the shape. This refractory member is connected to the heat-absorptive element through the use of an anchor pipe. The anchor pipe is a tubular insert that is inserted through the metal-mesh embedded in the refractory member and then welded to both the metal mesh and the heat-absorptive element. By securing the anchor pipe to both the metal mesh embedded within the refractory member and the heat-absorptive element, the refractory member remains connected to the heat-absorptive element.
[0007] However, the anchor pipe used in this refractory system suffers from several disadvantages. First, it takes considerable time and effort to weld the metal spirals to the anchor pipe to ensure that the anchor pipe remains secure within the refractory member. Second, the anchor pipe must always be secured to the heat-absorptive element by means of welding. Third, a washer must be welded into the anchor pipe to generate a lip which allows the refractory member(s) to be bolted to the heat-absorptive element.
[0008] It is therefore an object of the present invention to allow the operator the option of connecting the refractory member to the heat-absorptive element by either a bolting process or a welding process while also minimizing the steps necessary to secure a tubular insert within the refractory member.
SUMMARY OF THE INVENTION
[0009] The present invention is directed to a protective refractory member for use in a high-temperature furnace. In one embodiment, the present invention comprises a refractory member, a reticulated metal structure embedded within the member and positioned so that there is at least one uninterrupted passageway through the metal structure and the member, a tubular insert located within the passageway wherein the tubular insert is comprised of a hollow tubular body with an outer diameter sized so that the tubular insert fits within the uninterrupted passageway, and two tubular insert ends wherein the outer diameter of the first end is larger than the outer diameter of the second end so that the second end fits within the uninterrupted passageway and the first end engages the metal structure.
[0010] In one variation, the inner diameter of the second end of the tubular insert is smaller than the inner diameter of the tubular body.
[0011] The refractory member of the present invention may additionally comprise a bolt, which is inserted through the tubular insert and secures the refractory member to a heat-absorptive element. Alternatively, the second end of the tubular insert can be connected to the heat-absorptive element by way of a weld.
[0012] In another variation, the invention may additionally comprise a bolt which is inserted through the tubular insert and connects the refractory member to another refractory member and thereby secures both refractory members to a heat-absorptive element within the furnace.
[0013] In another embodiment, the present invention comprises a first refractory member located immediately adjacent to and substantially covering one side of a heat-absorptive element and a second refractory member located immediately adjacent to and substantially covering the opposite side of the heat-absorptive element. In each of the refractory members, a reticulated metal structure is embedded therein and positioned so that there is at least one uninterrupted passageway through the structure and the refractory member. Additionally, in each of the refractory members, a tubular insert is located within the passageway, wherein the tubular insert is comprised of a hollow tubular body with an outer diameter smaller than the diameter of the uninterrupted passageway and two tubular insert ends wherein the outer diameter of the first end is larger than the diameter of said uninterrupted passageway. The first end of the insert engages the metal structure and the second end of the insert contacts the heat-absorptive element. The first and second refractory members are then secured to the heat-absorptive element. The heat-absorptive element can optionally be a water-cooled pipe.
[0014] This embodiment of the present invention may further comprise a bolt for securing the refractory members to the heat-absorptive element. Alternatively, at least one of the tubular inserts can be connected to the heat-absorptive element by way of a weld.
[0015] In another variation, the inner diameter of the second end of the tubular insert is smaller than the inner diameter of the tubular body of the insert.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a longitudinal sectional view of a tubular insert.
[0017] FIG. 2 is a plan view of the body of the tubular insert as it contacts an embedded metal structure.
[0018] FIG. 3 is a plan view of the lip of the tubular insert as it contacts and engages the metal structure.
[0019] FIG. 4 is a sectional view of a complete refractory system which illustrates the manner in which the tubular insert secures refractory members to a pair of heat-absorptive pipes by bolting the tubular insert directly to the heat-absorptive element.
[0020] FIG. 5 is a schematic view of the tubular insert as it engages the metal structure and contacts the heat-absorptive element which is protected by the refractory member.
[0021] FIG. 6 is a sectional view of a complete refractory system which illustrates the manner in which the tubular insert secures refractory members to a pair of heat-absorptive pipes by welding the tubular insert directly to the heat-absorptive element.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0022] A tubular insert is shown in FIG. 1 . The tubular insert 1 is a tubular member with an outer diameter that is consistent throughout its body 2 and includes two ends. At one end of the tubular insert, hereinafter known as the distal end, the outer diameter increases so as to form a lip, or rib, 3 around the outer circumference of the tubular insert 1 . The inner diameter of the tubular insert remains constant from the distal end until the opposite end, hereinafter known as the basal end. At the basal end, the inner diameter narrows, creating a shelf, or inverted lip 4 , around the inner circumference of the tubular insert 1 . The radial extent of this shelf 4 is such that a flat washer can rest on the area between the inner diameter of the tubular insert body 2 and the inner diameter of the shelf 4 . Optionally, this washer is a locking washer. Preferably, the difference between the inner diameter of the tubular insert body 2 and the inner diameter of the shelf 4 is between ¼″ and ½″, and ideally the difference in diameter is 11/32″. However, there remains an opening 5 in the basal end of the tubular insert 1 sufficiently large to allow the necessary angle for a weld rod so that a good structural weld can be obtained between the basal end of the tubular insert 1 and the surface of a heat-absorptive element to be protected. The opening 5 in the basal end of the tubular insert 1 is preferably between ½″ and 1″ in diameter and ideally is 25/32″ in diameter. The tubular insert 1 can be made out of any weldable metal, such as carbon steel, and is preferably constructed of stainless steel pipe, such as 304 stainless. The length of the tubular insert 1 varies depending on the density of the refractory member, with a longer tubular insert being feasible in a less dense, better insulated member. Generally, the tubular insert will be on the order of ½ the thickness of the refractory member, but ¾″ tubular inserts can also be used with 2″ thick refractory shapes.
[0023] The tubular insert of the instant invention is to be used with a refractory member similar to that described in U.S. Pat. No. 4,528,672, which is expressly incorporated herein by reference. Specifically, the tubular insert of the current invention is to be used with a refractory member having a reticulated metal structure, optionally defined by a plurality of spirals, embedded within. The metal structure may, for example, be in the form of a chain mesh, similar to a link fence, or in the form of a plurality of chains.
[0024] When using the tubular insert 1 to secure the refractory member to the heat-absorption element, the tubular insert 1 is positioned within a passageway 6 through the metal structure 8 . The outer diameter of the tubular insert body 2 is specially sized so that it fits securely in this passageway 6 and remains in contact with the metal structure 8 at a plurality of locations 7 , as seen in FIG. 2 . The lip 3 located at the distal end of the tubular insert 1 has an outer diameter that is larger than the passageway 6 so that the lip 3 engages the metal structure 8 , thus preventing the tubular insert from passing completely through the passageway 6 , as seen in FIG. 3 . As illustrated in FIG. 5 , when the tubular insert 1 is forced into contact with the heat-absorptive element 9 , the lip 3 may collect and gather the metal structure 8 , thus increasing the contacts between the tubular insert 1 and the metal structure 8 . This connection between the tubular insert 1 and the metal structure 8 serves both to ensure that the tubular insert 1 remains securely embedded within the refractory member and to dissipate heat from the tubular insert 1 into the refractory member, preventing the rapid deterioration of the tubular insert 1 .
[0025] A typical application of a bolt to connect the tubular insert to the heat-absorptive element is shown in FIG. 4 . Two parallel water cooled metal pipes 10 are connected with a metal web 11 . The metal web 11 has a hole in it sufficient in size to allow, for example, a bolt, screw, nail or other connection device to pass through. A refractory member 12 a and 12 b is positioned on either side of the tandem pipes 10 . A tubular insert 1 a and 1 b is inserted into each of the refractory members 12 a and 12 b until the basal end comes into contact with the metal web 11 . Alternatively, the tubular insert 1 a and 1 b can be integrated into the refractory member 12 a and 12 b , such as by a weld, adhesive, or snap-fit arrangement, for example, before the refractory member 12 a and 12 b is positioned adjacent the heat-absorptive element. The tubular inserts 1 a and 1 b are positioned so that they are in line with the hole in the web 11 allowing an open channel to exist. In one embodiment, a ⅜″ by 1″ (outer diameter) flat washer 13 a and 13 b is positioned on the internal washer ledge 4 of each of the tubular inserts 1 a and 1 b . On the flat washer 13 a is placed a ⅜″ locking washer 14 and a ⅜ screw 15 or bolt is inserted through the tubular insert 1 a containing the lock washer 14 , through the hole in the web 11 , and eventually through the other flat washer 13 b . A ⅜″ hex nut 16 is tightened onto the screw 15 so that the two tubular inserts 1 a and 1 b are each secured against the web 11 of the metal pipes 10 . Because the tubular insert 1 a and 1 b is also securely retained within the metal structure 8 of the refractory members 12 a and 12 b , the refractory members 12 a and 12 b are securely connected to the metal pipes 10 , protecting them from the surrounding environment. Other securing arrangements using the tubular inserts 1 a and 1 b , in addition to the bolt and nut arrangement, will be appreciated to those skilled in the art. For example, a wing nut or expansion nut could be used in securing the tubular inserts 1 a and 1 b to the heat-absorptive element.
[0026] A typical application of the use of a weld to connect the tubular insert to the heat-absorptive element is shown in FIG. 6 . Two parallel water cooled metal pipes 10 are connected with a metal web 11 . A refractory member 12 a and 12 b is positioned on either side of the metal pipes 10 and a tubular insert 1 a and 1 b is inserted into each of the refractory members 12 a and 12 b until the tubular insert 1 a and 1 b comes into contact with the metal web 11 . A weld rod is inserted into the opening in the tubular insert 5 a and 5 b , as will be apparent to those skilled in the art. The basal edge of the tubular insert, which is in contact with the metal web 11 , is welded to the surface of the web 11 . This weld 17 may go around the inside perimeter of the tubular insert 1 a and 1 b or it may be a fillet weld or a pair of such welds. Because the tubular insert 1 a and 1 b is also securely retained within the metal structure 8 of the refractory members 12 a and 12 b , the refractory members 12 a and 12 b are securely connected to the metal pipes 10 , protecting them from the surrounding environment.
[0027] The tubular insert provides many advantages over the prior art. For one, the tubular insert reduces labor and associated costs required to manufacture the refractory member. Additionally, the tubular insert reduces inventory since a single refractory shape can be attached to a heat-absorptive element in several different ways, such as through a bolting or welding process. Other advantages of the invention over the prior art will be apparent to those skilled in the art.
[0028] While specific embodiments of the invention have been described in detail, it will be appreciated by those skilled in the art that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure. The presently preferred embodiments described herein are meant to be illustrative only and not limiting as to the scope of the invention which is to be given the full breadth of the appended claims and any and all equivalents thereof. | An arrangement for protecting heat-absorptive elements in a high-temperature furnace includes a refractory member comprised of an interconnected metal structure embedded within the member and a tubular insert element capable of attaching the refractory member to the heat-absorptive element. The tubular insert has a hollow tubular body that is capable of sliding within a passageway through the embedded metal structure. The tubular insert has a rib or lip with an outer diameter larger than the passageway through the metal structure that engages the structure. When the other end of the tubular insert is connected to the heat-absorptive element, the rib holds the refractory member in place without a need to weld the tubular insert directly to the metal structure. | 5 |
CROSS-REFERENCES TO RELATED APPLICATIONS
This application is a continuation of copending application Ser. No. 88,815 filed on Oct. 26, 1979 now U.S. Pat. No. 4,282,006, which application was a continuation-in-part of copending application Ser. No. 957,166 filed on Nov. 2, 1978, now abandoned, which was a continuation-in-part of copending application Ser. No. 790,337 filed on Apr. 25, 1977 and also now abandoned.
TECHNICAL FIELD
This invention relates to an improved pipeline pumpable high solids content coal-water slurry having a Brookfield viscosity of about 2000 cps or less at 60 rpm at about 75 wgt. %, dry basis, coal content. The slurry is utilized primarily for generation of heat energy in a furnace provided with slurry conveying means and equipped with either a cyclone or a turbulent type of burner.
Further, this invention relates to a method for making such an improved, high solids content coal-water slurry which is suitable for long distance pumpline conveyance to coal-water slurry combustion, gasification or other coal utilization processes, and, which is especially suitable for direct burning in a furnace into which the coal-water slurry is charged by means of a cyclone or a turbulent burner without further treatment, such as dewatering of the slurry.
More particularly, this invention relates to an improved high solids content coal-water slurry having yield pseudoplastic rheological properties suitable for pipeline transport and to a method for its preparation. The coal preferably is partially de-ashed.
Further, this invention relates to a slurry comprising finely divided particles of at least one solid material wherein the particles in the slurry have a particle size range and particle size distribution, and physical, and electrochemical attributes advantageous for transporting the slurry in a pipeline in the presence of a carrier fluid.
BACKGROUND OF THE PRIOR ART
Processes for preparing and utilizing partially de-ashed solid-fuel-water slurries and conveying the slurry by various conveying means, such as pumps, are known. O. Schwartz and H. Merten, Brennstoff Waerme Kraft 18 (10), 474-8 (1966) (Ger) describe a pilot plant in which coal was pulverized dry or wet in ball mills and disk grinders to provide particles up to 77% finer than 0.06 mm (60 μm).
Other processes are described in U.K. Pat. No. 711,105; French Pat. No. 1,581,112; and U.S. Pat. Nos. 3,423,313; 3,682,114; 3,941,552; 3,950,147; and 3,996,026, all of which are discussed in applicant's copending U.S. patent application Ser. No. 790,337, filed Apr. 25, 1977, which portion of said application Ser. No. 790,337 is hereby incorporated by reference herein.
In addition to the above-listed patents, McMurtrie, U.S. Pat. No. 3,019,059, issued Jan. 30, 1962, describes a process for transporting finely divided coal solids by forcing through a conduit an aqueous slurry containing up to 50% solids and containing a minor proportion of coal acids which are added to improve pumpability and to prevent settling during pumping. At the receiving end of the conduit, the slurry is filtered or otherwise processed to remove the water and coal acids and to recover the coal solids for use. Alkali metal and ammonium salts of humic acids are included in the term "coal acids".
Also, Reichl, U.S. Pat. No. 3,073,652, issued Jan. 15, 1963 describes a method of transporting coal over long distances for conversion at distant locations which comprises obtaining coal having a spectrum of sizes and between about 20 and 40 percent by weight of (-)325 mesh particles, (-44 μm), preparing a water slurry comprising between 35 and 60 percent by weight of said coal in water, pumping said slurry through a pipeline at a velocity of between about 3 and 7 feet per second over long distances to a distant location, interrupting the transportation of said slurry at said distant location, thereafter removing a portion of said water from said slurry to provide a concentrated slurry having a solids concentration of between 60 and 75 percent by weight of said coal in said water, pumping said concentrated slurry through a second pipeline over a shorter distance to a second location, and converting the coal in said concentrated slurry at said second location, or burning the concentrated slurry directly, if the burner is suitable for such burning.
Also, Clancey et al., U.S. Pat. No. 3,762,887, issued Oct. 2, 1973, describes a homogeneous composition of matter suitable for use as a liquid fuel consisting essentially of particulate coal and water in the relative proportions of 54 to 69 percent by volume of coal (61.3 to 75.0 wgt %) and 46 to 31 percent by volume of water, said particulate coal having a size distribution substantially as follows: 0 percent by weight on 4 mesh Tyler Standard screen, 18 to 33 percent by weight less than 325 mesh, less than 60 percent by weight between 4 and 28 mesh, and the balance in the size range of 28 to 325 mesh. The coal-water slurry is described as being pumpable, storable and directly burnable in a cyclone burner.
Commercially operated coal-slurry pipelines have been in operation for many years in the United States. Such pipelines and their successes, failures, and problems have been described in various publications, including the following:
"The Black Mesa Story" by F. H. Love, Pipeline Engineer, November 1969;
"Slurry Pipelines, Energy Movers of the Future" by E. J. Wasp, and T. L. Thompson, Oil and Gas Journal, Dec. 24, 1973;
"Research and Development for Slurry Pipeline System Design" by T. C. Aude and R. L. Gandhi, Bechtel, Inc., San Francisco, prepared for delivery at "The Second International Technical Conference on Slurry Transportation", Las Vegas, Nev., Mar. 2-4, 1977;
"Operating Experiences at the 1580 MW Coal Slurry Fired Mohave Generating Station" by M. L. Dina, presented at The International Conference on Slurry Transportation at Battelle Memorial Institute, Columbus, Ohio, Feb. 3, 1976;
"Utilization of Pipeline Delivered Coal", by P. E. Snoek et al., Bechtel, Inc., San Francisco, for ASME Joint Power Generation Conference, Buffalo, N.Y., Sept. 20, 1976; and
"Coal Slurry Pipelines", Van Nostrand Scientific Encyclopedia, fifth edition, 1976, Page 58.
The problem of preparing coal-water slurry for long distance delivery through pipelines ranging in diameter from about 4" to 48" to be burned at the delivery depot is to be distinguished from the problem of preparing a coal-water slurry from which a more concentrated slurry or a coal "cake" is prepared at a use site and burning the concentrated coal-water slurry or "cake" so prepared. Also, the problem of burning coal-water slurry in a turbulent burner is to be distinguished from burning coal-water slurry in a cyclone burner of a furnace. For examples of burners, see Chemical Technology: An Encyclopedic Treatment, J. F. Van Oss, Barnes and Noble Books, Div. Harper & Row, Publ., Inc. N.Y. 1971 Vol. II, Pages 722-725.
BRIEF SUMMARY OF THE INVENTION
This invention relates to a coal-water slurry comprising a high content, e.g. 60-80 wgt. %, dry basis, of finely-divided particles of coal having in combination physical and electrochemical characteristics which provide the slurry with low viscosity and other rheological properties required for transporting the slurry in a pipeline over long distances. The invention further relates to a novel method for making coal-water slurry of the invention.
In one aspect, the invention relates to a coal-water slurry suitable for pipeline transport which comprises:
(i) a coal compact comprising finely-divided coal particles having particle sizes in the range of about 1180 μm to 0.05 μm with at least 5 wgt. % of the particles being of colloidal size, said particles in said compact having a particle size distribution substantially in accordance with the following formula: ##EQU1## where
CPFT=cumulative weight percent, dry basis, of particles finer than a particle μ of stated size,
D.sub.μ =diameter of particle μ,
D L =diameter of largest particle in compact, sieve size or its equivalent,
D S =diameter of smallest particle in compact, SEM size or its equivalent,
n=numerical exponent, with n being in the range of 0.2 to 1.0, and with all diameters sized in μm,
(ii) carrier water in an amount at least sufficient to transport said coal compact in a pipeline,
(iii) counterion charged bound water layers on at least said particles of colloidal size, and
(iv) an effective amount of at least one electrolyte and/or dispersing agent(s) present in said carrier water and providing counter-ions to said bound water layers on said particles in an amount sufficient to maintain the zeta potential at near maximum zeta potential and sufficient to disperse said coal particles.
The particle size distribution of the coal compact according to the above formula for CPFT provides a non-undulating size distribution of particles which permits closer packing of more particles of coal in a specific volume of space in the compact than can be achieved with a particle size distribution which has an undulating distribution of particles. Also, sizes of D L and D S have important effects on the suitability of the particle size distribution for use in the coal-water slurry. When D L is too large, large particles can settle out and cause pumping problems. When D S is too large and less than about 5 wgt. %, dry basis, of particles of colloidal size are present in the coal compact, the stability of the yield stress and the rheological properties of the coal-water slurry are adversely affected and the slurry may segregate or become dilatent or otherwise not pumpable. The value of the numerical exponent n in the formula CPFT is affected by the values of D L and D S . While n will usually range from 0.2 to 1.0, n preferably will be in the range from about 0.2 to 0.7. D L usually will be in the range from 1180 μm to 38 μm and will preferably be in the range of 70 μm (micrometer or micron) to 600 μm, and most preferably will be about 300 μm. D S will be less than 3 μm (<3 μm) and usually will be in the range of 0.05 μm to 0.3 μm, and preferably will be about 0.1 μm.
The counterions provided by the electrolyte and/or dispersing agent(s) are of opposite charge to that of the counterions also cooperate with counterions which already may be present in the bound water layers on aged wetted coal particle surfaces to provide bound water structures which help to provide zeta potential to disperse the coalparticles in the compact in the carrier water, due to the repulsive electrical charges on the particles. These ions also help to affect the structure of the bound water layers to permit closer packing of the particles, and thereby provide the yield pseudoplastic rheological properties to the slurry. When the surfaces of the coal particles are freshly wet milled surfaces, the electrolyte and/or dispersing agent and the carrier water present during milling cooperate to provide the particles immediately with "near maximum zeta potential" required for dispersion of the particles in accordance with the invention. A near maximum zeta Potential is beneficial and must be maintained. Allowing the zeta potential to rise to maximum is detrimental as discussed below.
The amount of coal present in the coal-water slurry usually will range from about 45% to 80%, or even higher, by weight, dry basis. Preferably, the amount of coal will be from about 65% to 80% by weight, dry basis. The amount of electrolyte and/or dispersing agent(s) usually will range up to about 4 wgt. % based on total weight of dry coal, and preferably will range from 0.05 to 2.0 wgt. %, same basis. The amount of carrier water will be an amount sufficient to bring the total weight of coal-water slurry to 100% by weight. Slurry Brookfield viscosity usually will be less than about 3000 cps at 60 rpm. For example, a coal-water slurry made at 76.1 wgt. % coal, dry basis, was found to have a viscosity of about 2000 cps, see FIG. 1, B, and C.
The specific electrolyte and/or dispersing agent(s) present in the slurry and its amount have been found to be peculiar to coal from a particular source and to the carrier water used. Accordingly, the electrolyte and/or dispersing agent(s) and its amount needed for dispersing a particular coal in a particular carrier water in making the coal-water slurry preferably is selected by a method involving a series of laboratory titrations wherein the zeta potential is measured in a standard way. The candidate electrolytes and/or dispersing agent(s) are tested to determine their zeta potential maximizing propensities on a <10 μm sample of particles of coal from the above coal compact from a standard sized mass of the coal stirred in a sample of the carrier water. Optimum amounts of agent or agents are similarly determined.
In an equivalent selection method, the electrolyte and/or dispensing agent is selected by measuring shear rate versus viscosity of a stirred suspension of the coal particles in a sample of the carrier water while titrating with increasing amounts of the agent(s). It has been found that maximum zeta potential values correlate well with a leveling off in Brookfield viscosities of the slurry as increased amounts of a particular agent are added in increments.
In another aspect, the invention relates to an improved method for preparing a coal-water slurry suitable for pipeline transport comprising dispersing finely-divided coal particles in water, characterized by the steps which comprise:
(i) providing a coal compact comprising finely-divided coal particles having particle sizes in the range of about 1180 μm to 0.05 μm with at least 5 wgt. % of the particles being of colloidal size, said particles in said compact having a particle size distribution substantially in accordance with the following formula: ##EQU2## where
CPFT=cumulative weight percent, dry basis, of particles finer than a particle μ of stated size,
D.sub.μ =diameter of particle μ,
D L =diameter of largest particle in compact, sieve size, or its equivalent
D S =diameter of smallest particle in compact, SEM size, or its equivalent
n=numerical exponent, with n being in the range of 0.2 to 1.0, and with all diameters sized in μm,
(ii) providing carrier water in a total amount at least sufficient to transport said coal compact in a pipeline,
(iii) determining the voltage and polarity of the zeta potential of a sample of coal particles from said coal compact when dispersed in a sample of said carrier water,
(iv) determining from the results of step (iii) the type and amount of zeta potential enhancing electrolyte and/or dispersing agent(s) needed to adjust the zeta potential of at least the colloidal particles of said coal compact when mixed with said carrier water to a voltage near maximum zeta potential and sufficient to disperse said coal particles.
(v) providing in said coal compact of step (i), or in said carrier water of step (ii), or in a mixture thereof the type and amount of zeta potential enhancing electroyte and/or dispersing agent(s) determined to be needed from step (iv),
(vi) blending said coal compact, carrier water, and electrolyte and/or dispersing agent(s) together to form said coal-water slurry.
In a preferred embodiment, a novel coal-water slurry containing in the range of 45% to 80% by weight of coal, dry basis, is prepared by the method which comprises:
(i) pulverizing, in the presence of a pre-determined portion of the total amount of at least one electrolyte and/or dispersing agent(s) and in a minor amount of all the carrier water needed to transport said coal-water slurry in a pipeline, a first fraction of coal to prepare a pulverized dispersed coal fraction having particles substantially all finer than about 300 μm,
(ii) providing with a major amount of all said water and in the presence of the remaining portion said predetermined amount of said at least one electrolyte and/or dispersing agent(s) a second fraction of pulverized dispersed coal having coal particles of a fineness such that, when blended with said first fraction of coal particles to form a coal compact, the total blended mass will form a compact which contains a net of about 10 wgt. % of particles which are less than 3 μm in size,
(iii) blending said first and second fractions together in amounts by weight sufficient to provide a coal-water slurry having a coal compact with coal particles having a size in the range of about 300 μm×0.1 μm with at least about 10 wgt. % of said particles less than 3 μm in size and distributed substantially in accordance with the following formula: ##EQU3## where
CPFT=cumulative weight percent, dry basis, of particles finer than a particle μ of stated size,
D.sub.μ =diameter of particle μ,
D L =300 μm, sieve size, or its equivalent
D S =diameter of smallest particle in compact, SEM size, or its equivalent
n=numerical exponent, with n being in the range of 0.3 to 0.5, and with all diameters sized in μm.
In a most preferred embodiment, the above preferred method includes the further improvement wherein: said total amount of said at least one electrolyte and/or dispersing agent(s) being pre-determined by:
(iv) determining the voltage and polarity of the zeta potential of a sample of coal particles milled to <10 μm from said coal and dispersed in a sample of said carrier water, and
(v) determining from the results of step (iv) the type and amount of zeta potential enhancing electrolyte and/or dispersing agent(s) needed to adjust the zeta potential of at least the colloidal particles of said coal compact when mixed with said carrier water to a voltage near maximum zeta potential and sufficient to disperse said coal particles.
Preferably, the electrolyte and/or dispersing agent(s) will be an organic anionic surfactant, or an inorganic salt selected from NaOH, K 2 CO 3 , or Na 2 SiO 3 .9H 2 O. Most preferably, a combination of the organic anionic surfactant and at least one of the above electrolytes is
The coal preferably will be de-ashed to remove a substantial amount of unwanted minerals, such as clays and sulfur.
Definition of Terms
The following definitions of terms are provided for a clearer understanding of the invention.
Particles of solids, their sizes and other characteristics, and methods for determining their sizes and size distributions and other characteristics in a "consist" are well-known. As used herein, and in the prior art, the term "consist" means the particle size distribution of the solid phase of the coal-water slurry. For example, in the prior art, the term "8 mesh ×0" indicates coal with a graded size, or consist, of coal particles distributed in the range of 8 mesh and zero (dust), or 2360 μm×zero (dust). Similarly, as used herein, the term "about 1180 μm×0.05 μm is intended to mean and indicates coal with a nominally measurable graded size, or "consist", of coal particles distributed in the range of from about 1180 microns to a measurable colloidal size, e.g. at least about 0.05 microns. The term "about 1180 microns" is nominally equivalent to a U.S. Series 16 mesh sieve, substantially as defined in Handbook of Chemistry and Physics, 54th Edition 1973-1974 CRC Press, Cleveland, Ohio, page F-143 "Standard Test Sieves (wire cloth)". Unless otherwise stated, the weight of coal is on a moisture free or "dry basis" herein.
The term "coal compact" as used herein defines a mass of finely-divided coal particles which are closely packed in accordance with the invention.
The term "Alfred formula consist" defines a particle size distribution in accordance with the Alfred formula.
The term "Alfred formula compact" defines a coal compact having an "Alfred formula consist".
The term "Alfred formula coal-water slurry" defines a coal-water slurry made with an "Alfred formula compact" and/or a coal-water slurry wherein the coal consist is an "Alfred formula consist".
The term "pulverized coal" or "P.C." as used in the prior art defines coal which has been milled or ground to a "consist" of about 40 mesh×0 as indicated in Handbook of Chemistry and Physics, supra, 51st Edition, 1970 1971, page F-199. Unless otherwise indicated, the term "P.C." has the same meaning herein.
In view of the manner in which coal fractures during milling, coal particles will have irregular shapes which however, are of a body, or maximum side-to-side thickness, such that the sub-sieve sized discrete particles will pass through a specified mesh of a sieve. The size of the discrete particle can be expressed in terms of a spherical diameter which, as used herein, is defined as a U.S. sieve size of from 16 mesh to 400 mesh (38 μm) or its equivalent in microns through which a coal particle from a sample of coal or coal-water slurry will pass. For particles finer than 200 mesh, the size of the particles can be expressed in μm as determined by means of a sieve, or a Sedigraph, or a scanning electron microscope (SEM). Accordingly, both sieve size and SEM sizes or their equivalents, however determined, are used in describing the invention.
Means for crushing, milling, including ball milling and roller milling, disc grinding, screening, recycling, dry (air) and wet (water) separating, and blending or otherwise combining coal fractions to obtain a compact of a desired particle size and consist are well known, as may be ascertained from the above cited prior art.
For measuring particle sizes and for determining particle size distributions of pulverized and fine grind coal particles used for preparing a coal-water slurry of the present invention, the following three means of measuring particle sizes were used and are preferred:
1. U.S. Series sieves Nos. 16, 20, 30, 40, 50, 70, 100, 140, and 200 were used to determine weights of coal particles passing through each sieve in the range of about (-) 1180 μm to (-) 75 μm, including D L where it is at least 75 μm in size in the coal and the coal-water slurry. The cumulative weight percents of coal particles, dry basis, finer than (CPFT) a particular stated sieve size in microns were charted against the sizes in microns on a log-log chart, referred to herein as a "CPFT chart", to indicate the nature of the particle size distribution of 20 mesh×200 mesh particles, substantially as shown in FIGS. 9-12.
2. A Sedigraph 5500L (made by Micromeritics, Co., Georgia, U.S.) was used to measure particle sizes and numbers of particles in coal and in the coal-water slurry in the range of (-) 75 μm to about 0.3 μm. The Sedigraph 5500L uses photo-extinction of settling particles dispersed in water according to Stoke's law as a means for making the above determinations. Although some measure of inaccuracy exists in measuring the range above 30 μm and below 1 μm, the determinations are found to be reasonably accurate and suitable for purposes of the invention in the range of 30 μm to 0.1 μm. Other instruments, such as a Coulter Counter can also be used for similar accuracy. The results were plotted on the above CPFT chart.
3. A scanning electron microscope (SEM) at 40,000×magnification was used to determine D S in the colloidal range below 1.0 μm in the coal compact or in the coal-water slurry. The determination is made by preparing a dilute suspension of coal particles or by diluting a sample of disperse coal-water slurry to a dilution of about 10 wgt. % of coal per weight of solution. The dilute suspension is allowed to settle for two hours, (for example in a 100 ml graduate) and samples of the finest sizes are taken from the top one ml. of the suspension. This sample is further diluted with alcohol, and the diluted suspension or dispersion is examined on a copper pedestal using the SEM in a known way to find and measure the diameter, D S , of the smallest coal particle. This data is also plotted on the above CPFT chart. The plots from the three measurements are connected to obtain a "CPFT chart line", or curve.
It is to be noted that in view of the nature of the measuring means available, the values of D L and D S must be considered as values which are precise only within the limits of the means used for their determination.
In addition to the above particle size measurements can be estimated from methylene blue index measurements to obtain an approximate determination of the wgt % of colloidal particles of size below about 1 μm. Such a procedure is described in A.S.T.M. Standard C837-76.
The term "particle size distribution line" as used herein in relation to a coal particle compact herein means a "CPFT chart line" representative of the consist of the coal compact, (i.e. its particle size distribution) measured as described above. For example, when CPFT, e.g. in wgt %, is plotted against particle sizes, e.g. in microns (μm) on a log-log chart, a smooth line is formed on thechart when the points of the plots are connected by a continuous line. The "CPFT chart line" may be straight or curved and may have a slope of up to 1.0, but should be substantially free of peaks and valleys, referred to herein as "inflections" or "undulations", indicative of irregularities in content of amounts of the various particle sizes required in a compact in order for a non-undulating CPFT chart line to be obtained. Preferably, the CPFT chart plot line should be a smooth, or substantially "non-undulating", line from 100% to 1% CPFT. A "non-undulating line" is defined herein as a CPFT chart line of which the slope of a tangent at any point on the chart line is within the upper and lower values for n in the Alfred formula. Small undulations, within these outer limits for n may be tolerated. Large undulations may render slurry unsuitable for pumping especially at high concentrations, e.g. over 65 wgt. %. The particle size distribution of coal particles in the compact depicted by the non-undulating line of the chart will correlate with a "smooth" distribution of particles of sizes ranging from D L to D S . The significance of this distribution will be discussed later herein in relation to the packing of particles in accordance with the invention.
The term "high solids content slurry" means a coal-water slurry, e.g. over about 60 wgt. %, dry basis, wherein the coal solids are present at a solids loading level at which interparticle reactions would normally prevent fluidity of the slurry, making it unpumpable; the fluidity required for pumping is obtained and maintained by practice of the method of this invention as herein described.
The term "zeta potential", which is used in describing the invention herein, has the meaning given it in the field of colloid chemistry. Concise discussions and descriptions of the zeta potential and methods for its measurement are found in many sources, including, T. M. Riddick, U.S. Pat. No. 3,454,487, issued July, 1969; Douglas et al., U.S. Pat. No. 3,976,582, issued Aug. 24, 1976; Encyclopedia of Chemistry, 2nd edition, Clark et al., Reinbold Publ. Corp. 1966, pages 263-265; Chemical and Process Technology Encyclopedia, D. M. Considine, editor-in-chief, McGraw-Hill Book Company, N.Y., pages 308-309; Chemical Technology: An Encyclopedic Treatment, supra, Vol. VII, pages 27-32; Kirk-Othmer, Encyclopedia of Chemical Technology, 2nd Edition, Vol. 22, pages 90-97; and T. M. Riddick, Control of Colloid Stability Through Zeta Potential, Zeta-Meter, Inc. New York City.
"Zeta potential" may be measured by conventional techniques and apparatus of electroosmosis such as those described, e.g., in Potter, "Electro Chemistry"; Cleaver-Hume Press, Ltd.,; London (1961). Zeta potential can also be determined by measuring electrophoretic mobility (EPM) in any of several commercial apparatuses. In the present invention, a Pen-Kem System 3000 (made by Pen-Kem Co. Inc. of Croton-on-Hudson, N.Y.) was used for determining zeta potential in the examples herein. This instrument is capable of automatically taking samples of coal particles and producing an (EPM) distribution by Fast Fourier Transform Analysis of millivolts from which the zeta potential can be calculated.
The zeta potential is measured using very dilute samples of the <10 μm sized coal particles in the coal compact of the coal-water slurry. The zeta potential is measured both to determine its polarity and charge in millivolts and to determine the effectiveness of a dispersing agent or combinations thereof, such as surfactant combinations, alone or with inorganic electrolytes present, for providing a suitable near maximum zeta potential for the coal particles in the coal-water slurry.
"Near maximum zeta potential", as used herein, means a value of zeta potential, measured at constant electrical conductivity, below the maximum zeta potential as defined and discussed in the references above. It is necessary to normalize the zeta potential values with respect to electrical conductivity, since zeta potential is, itself, a function of the electrical conductivity. This is a function of the above instrument. The term "near maximum zeta potential", as used herein means a zeta potential having a value in the range of about -40 to -70 millivolts, compared to an absolute maximum zeta potential, e.g. of about -80 to -100 millivolts, found to be obtainable in samples of Alfred formula coal-water slurry. The near maximum zeta potential must be of a millivoltage and polarity sufficient to provide coal particles with a repulsive charge great enough to disperse the coal particles in an Alfred formula coal-water slurry. However, the potential should not be allowed to reach a maximum millivoltage zeta potential, because the polarity of the charge on the particles may be reversed, causing the particles to flocculate. The zeta potential, therefore, need only be within close range of the maximum zeta potential to be effective for maintaining a coal-water slurry of the invention in a yield pseudoplastic rheology suitable for pipeline transport.
The term "surface-active agent", or "surfactant", as used in the prior art indicates any substance that alters energy relationships at interfaces, and, in particular, a synthetic organic comound displaying surface activity including wetting agents, detergents, penetrants, spreaders, dispersing agents, foaming agents, etc. Concise Chemical and Technical Dictionary, H. Bennett, Chemical Publ., Inc. N.Y., 1962.
The term "dispersing agent" as used herein is a form of surface-active agent which may be organic or inorganic and which is present on or in or is added to the coal or water or to the coal-water slurry and acts to create or to promote formation of a repulsive electrostatic charge on a coal particle in an aqueous medium at the interface of the bound water layer on a particle and of the diffuse layer of the bulk or "carrier water" surrounding the particle, thereby creating or amplifying the zeta potential, or electrostatic charge at the interface.
The term "wetting" as used herein indicates covering or penetrating the coal particle surface with a bound water layer. The terms "wetting agent" or "surfactant" as used herein indicate a dispersing agent which acts to provide or promote "wetting" of the coal particle surface. The term "surfactant" includes both organic and inorganic surfactants. Some coal surfaces are inherently wetted as mined and milled and may not require the aid of an additional wetting agent for practicing the present invention. As used herein "wetted coal" means both coal which has been wetted with a "wetting agent" and coal which is "wetted" by natural means when mined.
The term "deflocculating" as used herein indicates formation of a colloidal dispersion of colloid sized coal particles. "Colloids" are substances of which at least one component is subdivided physically in such a way that one or more of its dimensions lies in the range of 100 Åand 3 μm. As is known, these are not fixed limits and, occasionally, systems containing larger particles are classed as colloids. See Encyclopedia of Chemistry, supra, page 263. The term "deflocculating agent" as used herein indicates a dispersing agent which promotes formation of a colloidal dispersion of colloidal sized particles in the coal-water slurry.
In accordance with the above definitions, the term "dispersing agent" as used herein includes surface-active agents which also may be "wetting agents", "surfactants" and/or "deflocculating agents", any and/or all of which can be used to create or to amplify the zeta potential on a coal particle in an aqueous medium to a near maximum zeta potential in accordance with known ways in the preparation of a coal-water slurry in accordance with the method of the present invention.
The term "Brookfield viscosity" is used herein to define "viscosity" as measured by the conventional technique used in determining viscosity by means of a Brookfield Synchro-Lectric Viscosimeter (made by the Brookfield Engineering Laboratories, Stoughton, Mass.). The Brookfield viscosity as reported herein, unless stated otherwise, was measured as centipoises (cps) at 60 rpm. Coal-water slurry made according to the present invention usually is non-Newtonian fluid having yield pseuodoplastic rheological properties, and as such has no ordinary viscosity. A "yield pseudoplastic fluid" is a power law fluid with a yield stress, as more fully defined herein.
The term "electrolyte" means any substance which dissolves into electrically charged ions when dissolved in water or other polar solvent in the coal-water slurry. Thus, the substance can be an acid, base, or salt. Certain electrolytes have been found more beneficial than others for the practice of the present invention, as more fully discussed herein.
The term "stability" as used herein includes static and dynamic stability and as applied to a coal-water slurry of this invention means the capability of the slurry to maintain its level of homogenity over a selected period of time, such as, for example, a time measured from formation of the slurry with its particles dispersed at near maximum zeta potential to the time at which the slurry tends to undergo a change in its rheological properties. The term stability implies that the physical state of the slurry will not readily change or undergo fluctuations which would impair its use. For example, it implies that coarser particles will not settle out of the suspension and that neither segregation of coarse from fine particles nor flocculation of the coal particles will occur. Segregation of particles would alter particle packing efficiency and adversely affect the rheological properties of the slurry.
The term "bound water" as used herein means water retained in the "bound water layer" as defined and illustrated at page 91 of Kirk-Othmer, above, and as illustrated in FIG. 8 hereof and includes a fixed water layer adjacent to the surface of a particle.
The term "carrier water" as used herein means the bulk or free water dispersed between the coal particles and contiguous to the bound water layers on the particles. Zeta potential as used herein means the charge present at the interface of the bound water layer and the carrier water.
The term "yield pseudoplastic fluid" as used in describing the invention has the usual meaning associated with it in the field of fluid flow. Specifically, a yield pseudoplastic fluid is one which requires that a yield stress be exceeded before flow commences, and one whose apparent viscosity decreases with increasing rate of shear. In a shear stress vs. shear rate diagram, the curve for a yield pseudoplastic fluid shows a non-linearly increasing shear stress with a linearly increasing rate of shear. In a "pure" pseudoplastic system, no yield stress is observed so that the curve passes through the origin. However, most real systems do exhibit a yield stress indicating some plasticity. For a yield pseudoplastic fluid, the viscosity decreases with increased shear rate. This is an indication that the lower the yield stress, the more pumpable such a fluid will be.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be more fully understood by reference to the following detailed description thereof, when read in conjunction with the attached drawings, wherein like reference numerals refer to like elements and wherein;
FIG. 1 is a chart showing correlations between Brookfield viscosities in centipoises (cps) at 60 rpm and wgt. % of coal, dry basis, content of several Alfred formula consist coal-water slurries. Referring to FIG. 1, FIG. 1, A is a viscosity curve derived from Alfred formula coal-water slurry having a consist according to blend A of FIG. 11; FIG. 1,B is a viscosity curve derived from Alfred formula coal-water slurry having a consist according to blend B of FIG. 11 FIG. 1,D is a viscosity curve derived from Alfred formula coal-water slurry having a consist according to blend C of FIG. 11; FIG. 1, C is a viscosity curve derived from Alfred formula coal-water slurry having a consist according to the Alfred formula milled W. Virginia coal of FIG. 12.
FIG. 2 is a chart showing correlation among Brookfield viscosities in cps at 30 rpm, zeta potentials in millivolts (mv) and percents of dispersing agent used in determining amount of dispersing agent needed to obtain near maximum zeta potential in a 55 wgt. % coal-water slurry as further shown in FIG. 13.
FIGS. 3, 4 and 5 are charts showing titration curves and illustrating correlations between Brookfield viscosities and amounts of electrolyte and/or dispersing agent(s) used in determining optimum amounts of agent(s) to be used to obtain lowest viscosities.
FIG. 6 is a flow diagram illustrating an integrated process for preparing Alfred formula consist coal-water slurry and utilizing the slurry in a furnace.
FIG. 7 is a cross-sectional view of a typical atomizer, or turbulent flow, burner in which Alfred formula consist coal-water slurry can be burned.
FIG. 8 is a chart illustrating effect on solids content of monospheres of solids as adsorbed bound water layer film thickness is increased and showing the significance and importance of the minus 3 μm particle fraction in the Alfred formula consist of a coal compact and its effect on the yield pseudoplastic properties of the coal-water slurry in which the coal compact is present.
FIG. 9 is a chart showing correlations between particle size distributions (consists) by wgt. % and particle sizes in microns of: (A) typical Alfred formula coal compacts of this invention; (B) coal compacts having a theoretical Andreasen distribution, (C) a composite of coal compacts as determined from descriptions of coal-water slurries in prior art patents; and (D) a coal compact used in Black Mesa coal-water slurry, as described by Dina in the literature.
FIG. 10 is a chart showing correlations between particle size distributions (consists) by wgt. % and particle sizes in microns of ranges of coal compacts made according to the Alfred Consist formula at D L =1180 μm and at D L =38 μm with D S <3 μm in each consist, and further compared with a chart line plot of a coal compact representative of a commercial Black Mesa coal-water slurry.
FIG. 11 is a chart showing correlations between consists by wgt. % and particle sizes in microns of coal compacts made according to the Alfred consist formula from blends of coarse and fine fractions of Black Mesa coal and of West Virginia coal, respectively, with D L as shown and with D S <3 μm.
FIG. 12 is a chart showing correlations between consists by wgt. % and particle sizes in microns of a coal compact milled from West Virginia coal to an Alfred consist with D L =300 μm and D S =<1.0 μm and a coal compact representative of Black Mesa coal-water slurry, and further illustrating nominal upper and lower n value limits for the Alfred consist.
FIG. 13 is a chart illustrating titration curves derived in experimentally selecting electrolyte and/or dispersing agent(s) and determining the optimum wgt. % needed for dispersing coal particles in carrier water by addition of incremental amounts of agent, measuring shear rate in rpm after each addition, and correlating the shear rate in rpm with Brookfield viscosity in centipoises. FIG. 2 is based on the data shown in FIG. 13. Negative slope in FIG. 13 indicates yield pseudoplasticity and the lowest 30 rpm viscosity with yield pseudoplasticity indicates an optimum amount of dispersing agent to use to obtain an optimum slurry. Zeta potential measurements can be made at each addition and correlated to the wgt. % of dispersing agent at each reading as shown in the inset.
DETAILED DESCRIPTION OF THE INVENTION
As is well known, pipeline transportation of coal-water slurry may create many mechanical problems, such as, line plugging, settling during shut-down of flow, start-up of flow after shut-down, slope of pipelines, and corrosion and erosion of pipelines. Many of these problems have been overcome by the known processes. However, current technology still requires that the coal-water slurry be pumped in a turbulent regime, at a rate higher than a usual minimum velocity for a fluid of similar viscosity, in order to maintain the coal and water mixed in the slurry. Consequently, the known coal-water slurry pipeline systems must be operated either at a high flow rate or stopped.
Also, coal-water slurry preparation and usage as presently practiced create major economic problems including providing an adequate supply of water for slurry preparation, and involving expensive processing operations, such as, for dewatering and drying of coal, which in prior art processes is recovered as about 75% coal centrifuge cake from the coal-water slurry, at the delivery site for burning in furnaces. A further major economic problem which exists is that "underflow" from the dewatering operation causes a serious disposal problem for effluent coal fines, as well as being a significant economic waste of the coal fines. For example, Dina, supra, reports that to 1976 over 400,000 tons of underflow had not been utilized because of inability to burn it, or to difficulties associated with processing it.
Accordingly, at the time of this invention a great need existed for an improved high solids content coal-water slurry which can be easily prepared, which has static and dynamic stability and can be pumped through a pipeline for long distances at controllable speeds, and which then can be burned directly in a turbulent (atomizer) burner with a minimum amount of NO X formation, as well as in a cyclone burner furnace intended to burn lowgrade coal having a high ash content. The present invention provides such a coal-water slurry and significantly avoids many of the above mentioned mechanical, dewatering, and waste problems. Furthermore, the rheological properties of the coal-water slurry are such that the pumping rate of the slurry in a pipeline can be controlled, i.e. accelerated or decelerated, to accommodate varying demand rates at the user's facilities, without causing flocculation or settling of larger particles in the pipeline.
The present invention relates to a novel coal-water slurry of high solids content and of relatively low viscosity which usually has yield pseudoplastic rheological properties to enhance controllable pumpability, to permit storing prior to use, if desired, and to permit direct burning of the slurry. In the slurry, a compact of comminuted coal particles of an advantageous particle size distribution and having a content of a critical amount of particles of colloidal size is maintained by means of an electrolyte and/or dispersing agent in deflocculated condition with at least the colloidal particles at near maximum zeta potential in the carrier water. The larger coal particles in the slurry thereby are dispersed, and the slurry may be further rendered rheologically yield pseudoplastic by providing in the slurry a further effective amount of the electrolyte and/or dispersing agent(s) which preferably is an organicor inorganic surfactant, an inorganic electrolyte, or a combination of both, and which serves further to maintain the particles at near maximum zeta potential.
The invention also relates to a method for preparing such a novel coal-water slurry having its advantageously distributed coal particles maintained at near maximum zeta potential.
The invention further relates to utilizing coal-water slurry of the invention as a fuel for generation of heat and/or electrical energy in a suitable furnace, and for other uses, such as chemical, gasification and/or metallurgical uses, to all of which uses the slurry can be delivered by pipeline and conveying means for said slurry, such as pumps, at controllable flow rates.
The coal-water slurry of this invention is especially advantageous in that the slurry can be prepared for most uses as a 70-80 wgt % (dry basis) coal-water slurry which can be prepared at a distant location, pumped through suitably sized pipelines, such as those now in commercial use, and used directly in many cases without the need for dewatering of the slurry after pumping or without need for concentration of the slurry, for example, by evaporation, to obtain a burnable product, and/or to remove water which would interfere with the particular use intended.
In the prior art, the efficiency of coal-water slurry transportation is stated to depend upon a number of variables, the most important of which from an hydraulic standpoint are listed as (1) size consist; (2) velocity; and (3) concentration. The selection of a proper consist (size gradation) is stated to be important in order that homogeneous flow can be achieved at economic operating velocities. In the above described commercial Black Mesa 50 wgt % coal-water slurry, such a consist is of 8 mesh by 0 (approximately 0.1 inch particle size to dust). Homogeneous flow (solids evenly distributed across the pipe diameter) is stated to be important if excessive wear in the bottom of the pipe is to be avoided and stable operation achieved.
The prior art further teaches that equally important and directly related to size consist is the proper selection of velocities for transport. The velocity cannot be excessive so as to cause abrasion of pipe wall and high-pressure drops. Conversely, the velocity should not be so low as to cause heterogeneous flow, with resultant excessive wear in the pipe bottom or bed formation which will cause unstable operation. Generally, practical operating velocities with the above 50 wgt % coal-water slurry are taught to be in the range of 4 to 7 feet per second.
Finally, slurry concentration must be considered. The relationship between concentration and viscosity for any given slurry can be determined in laboratory bench testing. Although it varies for different slurries, all prior art systems generally demonstrate a point in inflection where a small increase in concentration causes a large viscosity increase. Hence, with such systems it is important to maintain a concentration range below the inflection point in order to provide good operation without excessive velocities. For coal, the practical concentration range of prior art coal-water slurry appears to be from 45 to 55% solids, according to the above-cited Van Nostrand Scientific Encyclopedia summary of coal slurry pipeline technology.
In contrast to the above limitation of concentration of coal-water slurry solids to 45 to 55 wgt % solids, dry basis, for pipeline transportation, the present invention provides a high solids content coal-water slurry having from 45 to 80 wgt %, or more, dry basis, coal solids concentration for pipeline transportation at velocities which can be less than those needed with the prior art systems, if desired, but which can be at least as high as those of the prior art. Furthermore, an inflection point in flow where a small increase in concentration causes a large increase in viscosity has not been evident in flow of Alfred formula coal-water slurry. Instead, it has been found that the change in viscosity with increase in concentration is a gradual change in keeping with the yield pseudoplastic rheological properties of the slurry.
The invention is also beneficial and advantageous in that the amount of water required to prepare and pump the 75 slurry is about 1/3 that required to prepare and deliver 50 wgt % coal-water slurries via long distance pipelines. For example, a coal-water slurry at 50 wgt % solids requires about 250 gals. of water per ton of dry coal, while slurry of this invention at 75 wgt % solids content requires about 83 gals. of water per ton of dry coal. Moreover, because water in a 70 to 80 wgt % coal-water slurry of this invention does not need to be removed from the slurry in order to be able to burn the coal, a considerable reduction results in the cost of the pipeline-delivered coal-water slurry. Furthermore, no waste "underflow" fines are left over to be dumped into a waste pond with the attendant evaporation of waste water required to form a dry mass. Such "waste water" is defined as brown or black water which for environmental protection purposes may not be allowed to seep into streams or water tables and therefore must be evaporated in order to dispose of the water content of the "underflow".
In summary, the Alfred formula coal-water slurry is a novel combination of coal particles and carrier water wherein the particle sizes and their distribution are controlled in accordance with a particle size distribution formula which is especially beneficial for providing a coal compact with a minimum amount of void space betweenparticles and a maximum amount of particle surface area with an advantageous amount of colloidal sized particles present, all of which features combine to enhance the dispersing effects generated by electrolytes and/or dispersing agents selected to provide a near maximum zeta potential to the particles and are added to disperse them and to thereby provide low viscosity to the resulting yield pseudoplastic coal-water slurry The low viscosities obtained, e.g. 1000 cps at 75 wgt. % coal, dry basis, as shown for example in FIG. 1 C, are so far as is known to the inventor hereof, significantly lower than viscosities of pipeline pumpable coal-water slurries of the prior art at similar solids content. Accordingly, the Alfred formula coal-water slurry hereof represents an advantageous and beneficial improvement in the coal-water slurry art to which the claims hereof are directed.
The coal-water slurry of the invention is prepared by a process which comprises in combination at least three steps which cooperate to achieve production of a high solids content pipeline pumpable coal-water slurry suitable for transport in long distance pipelines. These three steps and their functions may be summarized as follows:
(i) providing a coal compact of finely-divided coal particles wherein the particle size distribution is designed to minimize the void space between particles and to maximize the packing efficiency of coal particles of a broad spectrum of particle sizes in the range from 1180 μm to 0.05 μm, thereby also providing an optimum amount of particle surface area in the compact,
(ii) providing an effective amount of an electrolyte, which may be a dispersing agent, in carrier water to provide advantageous counterions to the bound water layer surrounding each coal particle, thereby to enhance the structure and electrochemistry of the bound water layer and to minimize the total water content of the slurry, and,
(iii) dispersing the coal particles of the coal compact in a sufficient amount of carrier water by means of a dispersing agent which is effective to raise and maintain zeta potential of the coal particles dispersed in the carrier water and which is provided in an amount sufficient, alone or in combination with the electrolyte, to provide the coal particles in the coal-water slurry with a zeta potential which is near, but essentially below, the maximum zeta potential to which the coal particles could be raised in the slurry, thereby promoting yield stress required in a slurry having yield pseudoplastic rheology while avoiding dilatency which could causepumping difficulties.
The particle size distribution, or consist, of the present invention, provides a major means for minimizing the carrier water content of the slurry and minimizes the porosity of the packed coal particles of the coal compact which must be filled with carrier water before adequate fluidity for transportation of the coal-water slurry in a pipeline is obtained. The principle on which this is based may be explained as follows.
In the case of a theoretical powder which consists of mono-sized spheres which pack in a simple orthorhombic array, the volume percent solids is calculated to be 60.51% and the porosity to be 30.49%. By filling the interstices with spheres which exactly fit into the voids, it is calculated that the solids content becomes (0.6051×0.3039+0.6051) 100=84.48% and the porosity is reduced to 15.59%. This procedure can be repeated with still smaller spheres to further reduce the porosity. Andreasen, cited in G. Herdan, Small Particle Statistics, 2nd Edition, Butterworth, London (1960), in 1929 showed a particle size distribution with a power law function which he described by the equation ##EQU4## and which he believed will produce optimum packing of particles when n is between 0.33 and 0.50. In Andreasen's formula,
CPFT=cumulative weight percent of particles finer than a selected particle size in microns
μ=any selected particle size in microns
D=the largest particle size in microns in the mass
n=slope of the plotted line of the values of CPFT vs particle size in microns on a log-log chart.
Andreasen's power law function in effect teaches perfect packing by ignoring the size of the smallest particle size, which therefore can be infinitely small. In comparing chart lines of the particle size distributions of prepared compacts of the present invention with Andreasen CPFT chart lines, it was found that the Andreasen formula did not provide chart lines which properly fit the distributions for the coal compacts found to provide low viscosities. It is believed that the reason for this discrepancy is that, as a practical matter, any particle size distribution must contain a finite smallest size for a particle, which Andreasen's formula does not do.
Therefore, a correction was made in the Andreasen formula to take into account the size of a finite sized smallest particle. Accordingly, a new expression for particle packing was derived which is as follows: ##EQU5## where D S is the smallest particle size, and CPFT and D L are the same as in Andreasen's formula above, D.sub.μ is diameter of a particle μ of a stated size, and n is a numerical exponent. The modified Andreasen formula is referred to herein as the "Alfred consist formula" for particle size distributions. It depicts closely the particle size parameters needed for describing practical particle packing in a coal compact of this invention and in similar compacts.
In the Alfred consist formula, the value of n is dependent on the sizes of D L and D S . The size of D L for a particular coal is a fully controllable function of the grinding operation. It can be controlled by grinding coal until a desired size of D L is obtained. The size of D S is a less controllable function. It is dependent on the grindability of a particular coal, and will usually be the same D S size for that coal ground in the same mill. However, in some cases, it may be advantageous to obtain a larger D S , for example, by screening out fine particles below a selected particle size.
The Alfred formula was used to prepare a series of computer printouts of CPFT values for various stated particles μ over a range of particle sizes for μ ranging from D S to D L for a range of nominal exponent n values in a parameter range which would provide at least 5 wgt. % of particles of size <3 μm for each value of n at selected D L and D S values.
Illustrative typical and preferred values computed for typical consists of coal compacts which can be made in accordance with the Alfred formula while meeting the above limitation of at least 5 wgt. % of (-) 3 μm particles in the compact are shown in Tables 1, 2 and 3.
Table 1 illustrates the compositions of typical and preferred consists of 1180 μm×0.3 μm coal compacts which can be made in accordance with the Alfred formula for coal compacts having D L of about 1180 μm, D S of about 0.3 μm and nominal n values of 0.1, 0.2, 0.35 and 0.4 while providing at least 5 wgt. % of particles of minus μm size. From the data, it is seen that at an n value of 0.1, the consist will have CPFT of about 19.5 wgt. % of a stated particle μ of <3 μm size, and at an n value of 0.4, the consist will have CPFT of about 5.7 wgt. % for a stated particle μ of <3 μm.
Table 2 illustrates the compositions of typical and preferred consists of 300 μm×0.3 μm coal compacts which can be made in accordance with the Alfred formula for coal compacts having D L of about 300 μm, D S of about 0.3 μm and nominal n values of 0.2, 0.3, 0.5 and 0.6 while providing at least 5 wgt. % of particles of minus 3 μm size. As can be seen from the data, at an n value of 0.2, the consist will have CPFT of about 20.5 wgt. % for a stated particle μ of 3 μm size, and at an n value of 0.6. the consist will have CPFT of about 5.0 wgt. % for a stated particle μ of <3 μm size.
Table 3 illustrates a range of coal consists with particle sizes denominated by usually used U.S. sieve mesh sizes as well as corresponding particle sizes in μm. The values for nominal wgt. % of particle μ finer than 3 μm and the nominal n limits where μis (-) 3 μm when CPFT is present at less than 5 wgt. % are tabulated from computer printout tables such as those shown in Tables 1 and 2. Consist Examples No. 1-22 were all computed with decreasing values for D L and a constant Value of 0.3 μm for D S . Consist Examples 23-28 were computed with a constant value of D L =300 μm (about 50 mesh) and values of D S which varied from 0.05 μm to 0.50 μm. It is seen from the nominal n values which correspond to the various D L -D S combinations in consist Examples 23-28 that the lower (on the chart) value of n decreased with increase in size of D S . This information is of value for controlling the yield stress properties of the coal-water slurry by providing a known range of D S which can be used to modify the properties.
As stated above, the data for Tables 1-3 was computed by fixing D S constant at 0.3 μm in the Alfred formula. It is to be understood that D S can be any D S in the range from 3 μm to 0.05 μm. Accordingly, comparable computer printouts of typical consists can be made where D S in the Alfred formula is held constant at any value between 0.05 μm and 3 μm. The data so derived can then be used to prepare an Alfred formula compact and an Alfred formula coal-water slurry having a consist in accordance with the corresponding Alfred formula consist.
Table 4 shows an analysis of the consist of FIG. 12 identified as Consist A, Alfred Formula West Virginia Coal Compact. Referring to FIG. 12, it is seen that the CPFT chart line for Consist A is well within the upper (n=0.2) and lower (n=0.6) parameter lines on the chart.
TABLE 1______________________________________TYPICAL CONSISTS OF 1180 μm × 0.3 μmCOAL COMPACTS NOMINAL n VALUES WHERESTATED CPFT IS AT LEAST 5 WGT.PARTICLE % WHEN μ IS < 3 μmμ, SIZE 0.1 0.2 0.35 0.4IN μm CPFT CPFT CPFT CPFT______________________________________.3 .0 .0 .0 .0.4 3.4 2.1 .9 .7.7 7.0 4.4 2.0 1.51.1 10.8 7.0 3.3 2.61.7 14.7 9.8 4.9 3.82.6 18.8 12.8 6.6 5.24.0 23.1 16.2 8.7 6.96.3 27.6 19.8 11.1 9.09.7 32.3 23.7 13.9 11.415.1 37.2 28.1 17.1 14.323.3 42.3 32.8 20.9 17.836.1 47.7 37.9 25.4 21.955.9 53.3 43.5 30.5 26.886.4 59.1 49.6 36.5 32.6133.6 65.2 56.3 43.5 39.6206.5 71.5 63.6 51.6 47.9319.3 78.2 71.5 61.1 57.7493.7 85.1 80.2 72.1 69.4763.2 92.4 89.6 85.0 83.41179.9 99.9 99.9 99.9 99.9______________________________________
TABLE 2______________________________________TYPICAL CONSISTS OF 300 μm × 0.3 μmCOAL COMPACTS NOMINAL n VALUES WHERESTATED CPFT IS AT LEAST 5 WGT.PARTICLE % WHEN μ IS < 3 μmμ, SIZE 0.2 0.3 0.5 0.6IN μm CPFT CPFT CPFT CPFT______________________________________.3 .0 .0 .0 .0.4 2.5 1.6 .6 .3.6 5.2 3.5 1.4 .8.8 8.1 5.5 2.3 1.41.2 11.3 7.8 3.4 2.21.8 14.7 10.4 4.8 3.12.6 18.3 13.3 6.4 4.33.8 22.2 16.5 8.3 5.85.4 26.4 20.0 10.7 7.67.9 30.9 24.0 13.5 9.811.3 35.8 28.4 16.8 12.616.3 41.0 33.4 20.8 16.123.5 46.7 38.9 25.6 20.433.8 52.7 45.0 31.4 25.848.7 59.2. 51.9 38.3 32.570.0 66.2 59.5 46.6 40.8100.7 73.8 68.0 56.5 51.2144.9 81.9 77.5 68.5 64.0208.5 90.6 88.1 82.8 80.0299.9 99.9 99.9 99.9 99.9______________________________________
TABLE 3__________________________________________________________________________TYPICAL CONSISTS OF VARIOUS COAL COMPACTS NOMINAL NOMINAL n LIMITS U.S. CUM. WGT. WHERE μ IS < 3 μmCONSIST SIEVE, STATED PARTICLE % μ FINER WHEN CPFT IS ATEXAMPLE MESH μ, SIZE IN μm THAN LEAST 5 WGT. %NO. SIZE D.sub.L D.sub.S 3 μm UPPER LOWER__________________________________________________________________________ 1 16 1180 0.3 19.5 0.1 -- 2 16 1180 0.3 5.7 -- 0.4 3 20 850 0.3 20.0 0.1 -- 4 20 850 0.3 5.2 -- 0.45 5 30 600 0.3 18.0 0.15 -- 6 30 600 0.3 5.0 -- 0.5 7 40 425 0.3 17.7 0.2 -- 8 40 425 0.3 5.8 -- 0.5 9 50 300 0.3 20.5 0.2 --10 50 300 0.3 5.0 -- 0.611 70 212 0.3 20.9 0.2 --12 70 212 0.3 5.0 -- 0.6513 100 150 0.3 25.3 0.2 --14 100 150 0.3 6.1 -- 0.6515 140 106 0.3 26.4 0.2 --16 140 106 0.3 5.7 -- 0.817 200 75 0.3 29.3 0.2 --18 200 75 0.3 6.6 -- 0.819 270 53 0.3 32.4 0.2 --20 270 53 0.3 7.7 -- 0.921 400 38 0.3 35.7 0.2 --22 400 38 0.3 7.0 -- 1.023 50 300 0.05 5.0 -- 0.63524 50 300 0.10 5.0 -- 0.62525 50 300 0.20 5.0 -- 0.60726 50 300 0.30 5.0 -- 0.59027 50 300 0.40 5.0 -- 0.57428 50 300 0.50 5.0 -- 0.557__________________________________________________________________________
TABLE 4______________________________________ANALYSIS OF CONSIST OF 300 μ m × <0.52 μmWEST VIRGINIA COAL COMPACTSTATED EXPONENTPARTICLE μ, n VALUE = 0.4SIZE IN μm CPFT______________________________________0.52 1.80.6 2.00.8 2.81.0 3.51.5 5.23.0 9.05.0 13.010.0 20.020.0 30.030.0 38.050.0 48.070.0 56.0100.0 65.0200.0 88.0300.0 99.9______________________________________
When the Alfred formula consist is followed closely, as shown in FIG. 12 and Tables 1-4, for example, optimum practical particle packing with minimum void space volume is obtained for a coal-water slurry. By minimizing void spaces of a compact of coal particles it is obvious that a minimum amount of carrier water is needed to fill those voids. This in turn reduces the total amount of water needed for obtaining system fluidity.
For obtaining maximum fluidity in a prepared Alfred coal-water slurry, the consist of the Alfred formula compact used to make the slurry should follow the Alfred equation from D L to D S as closely as practically possible, and preferably, exactly, with n having a substantially constant value in the formula depicting the acutal distribution size. Some fluctuations are found to commonly occur in the bimodal blends and tend to decrease the packing efficiency. Such fluctuations will cause n values to fluctuate also. However, it is still possible to obtain pipeline pumpable slurries if the actual distribution is relatively close to that required by the Alfred formula for particular values of D L and D S . It has been further found that rapid fluctuations in the values of n over the range of particle sizes from D L to D S are indicative of a non-uniform distribution of particle sizes in a compact in the range between D L and D S .
It has been found that producing in a coal compact a total particle size spectrum described by the Alfred distribution formula will produce a low viscosity slurry in the presence of appropriate electrolyte and/or dispersing agents(s), and unless the size distribution is in accordance with the formula distribution those same agents will not produce a pipeline pumpable, low viscosity slurry.
For practice of this invention, it is important that the coal particles present in the coal compact and in the slurry be provided to have as close a particle size distribution as possible to the Alfred formula. In one method, this can be done by grinding coal under grinding conditions which can be carried out and controlled in a known way until the desired D L , D S and Alfred particle size distribution in a desired n range for the coal compact is obtained. In a second method, a similar coal compact can be provided by blending several grinds of milled powders of coal to make a blend to obtain a similar Alfred particle size distribution in the compact as described by the above values, with a maximum solids content and with minimum void volume. Coal compacts prepared according to the Alfred formula can be used to prepare pipeline pumpable coal-water slurries having a minimum carrier water content and a low viscosity. For example, slurries of this invention have been produced having 77.5 wgt. % of coal, dry basis, and a Brookfield viscosity at 60 rpm less than 2000 cps. (FIG. 1C). Similarly, by using a proper combination of steps (i), (ii), and (iii) as disclosed herein, slurries may be produced having 80% wgt. % of coal, dry basis, and a Brookfield viscosity at 60 rpm less than 4000 cps (FIG. 1C) and be suitable for pumping in a long distance pipeline. In practicing the invention, it has been found that a large yield stress is required in the coal-water slurry when D L is large, e.g. 1180 μm, whereas a small yield stress is required when D L is small, e.g. 100 μm. Also, if low viscosity pumping requirements are more important for a particular use condition than is storage stability, then a lower n Newtonian or pseudoplastic slurry to no yield stress can be produced.
The other two steps required for making the coal-water slurry hereof, i.e. the electrolyte enhancement of the bound water layer to control the water structure, and the dispersing of the coal particles and maintaining them at near maximum zeta potential, are both achieved by chemical treatments of the water present on and between coal particles in the coal-water slurry. Together with the Alfred consist compact, these elements determine the nature of the plasticity, i.e. the rheological properties, of the coal-water slurry. It has been found that efficient packing of coal particles in a compact according to the invention provides a minimum porosity, or free pore space, into which a minimum amount, compared to prior art amounts, of carrier water needs to be provided in order to have sufficient water present to obtain fluidity of the mass and to make it suitable for pipeline transportation. Presence of this minimum amount of carrier water, which may be as little as about 20 wgt. % does not in itself render the mass fluid. However, by use of chemical treatment according to the invention in combination with the carrier water according to the invention, dispersion of the coal particles is achieved to separate the particles by repulsive charges in a known way in accordance with electrochemical principles. This step provides counterions which are believed to minimize the thickness of the bound water layer on a particle, and in effect affects its structure. Furthermore, it provides a zeta potential on the particles which helps maintain the closely packed particles in dispersed form.
More specifically, it has been found advantageous and beneficial in order to enhance the structure of the bound water layer and to control the zeta potential of a particle to take into account and, if necessary, to modify, the type and amount of counterions present in the bound water layer present on the individual coal particles and in the carrier water present between coal particles. This is done by controlling the type and amount of electrolyte needed and used in the coal-water slurry.
The method steps used to provide the coal particles with a zeta potential controlled at near maximum zeta potential will depend in part upon the surface chemistry of the mined coal as it enters the slurry preparation plant, its treatment there in carrier water, and upon the chemistry, or electrolyte content, of the carrier water, and the water associated with the coal in the slurry. The chemistry of the water associated with the coal can vary from that of the moisture inherent in the coal as mined to that of the residue of primary wash water used at the mine mouth to that of the water used in preparing the slurry. In each case, different electrolyte solution ions may be present in the water, with each source providing different electrolyte content and affecting pH of these solutions and zeta potential of the particles.
When water is added to a powder comprising finely divided particles, and provided that the water "wets" the powder, a surface water film is adsorbed on each particle which is know to be structually different from the surrounding "free" or bulk water, in that the film may be described as "semi-rigid", or bound water film. Depending on the fundamental electrical potential of the surface, this "semi-rigid" or bound water film may be of several molecules thickness. For example, on clays, the film has been estimated to about 80° A thick. Although the subject is controversial due to present inability to accurately measure these phenomena, both the thickness and the structure of the bound surface water film on the particle (hence its rigidity or non-mobility) can be influenced by both anionic and cationic additions to the system, depending on the polarity of the charge at the surface of the coal particle. It is well known that adding anions and cations to a dispersion of particles also changes the net residual electrical potential, or zeta potential, at the bound, or surface water film-free water interface. This zeta potential when maximized by counterions formed by ion exchange reactions between surface groups, such as acid groups and salt-like bonds on the surface of the coal particles and a counterion providing electrolyte deflocculates the particles, and when neutralized by other electrolytes allows flocculation of the particles by London-Vander Waals forces.
Coal, by its natural chemistry, may be expected to be hydrophobic (nonwetting), but due probably to its partial oxidation is sometimes hydrophilic. Consequently, for example, it has been found that coal from some mines, e.g. Black Mesa coal, can be deflocculated almost equally well using as the deflocculating agent either a water soluble anionic organic surfactant (Lomar D), believed to provide negative counterions, or a cationic alkali metal base, NaOH, providing positive counterions, or any combination of Lomar D and NaOH. West Virginia coal on the other hand requires the addition of the organic surfactant first to effect the surface water film adsorptivity, which then is deflocculated further by addition of the cationic NaOH.
Another phenomenon which is important is the oxidation state of the surface of the coal particles. Coal, as mined, may exist in various states of oxidation according to the amount and nature of salts dissolved in the bed water in the coal deposit, and the nature of the original flora which formed the precursor of the coal bed. Freshly ground coal is in a lower state of oxidation, compared with coal which has been ground and exposed to air. Therefore, it can be stated that the chemistry, including O 2 , and structure of ground coal and its surface oxidation state will determine the type and exact combination of dispersing agents, such as surfactants, which maximize the effectiveness of deflocculation. Freshly ground coal has been found more advantageous for practicing the process of this invention than older ground coal. Further, different coals may not react the same, because of their chemical constitutions. Thus, some experimentation may be required to determine the optimum combination of oxidation state, fines content and deflocculating agents, required both as to type and amounts for a particular coal. Such experimentation is well within the skills of one working in the coal slurry art.
Accordingly, it is to be expected that coal may require a specific chemical treatment depending on the specific chemical environments in the coal bed from which it is mined. While need for chemical treatment at least of the free water by means of electrolytes and dispersing agents is found to exist, it is to be emphasized that usually the chemical agents used are not critical. However, some agents have been found more advantageous for use with certain coals than have others, and their use is preferred.
In practice of the invention, it is preferred also that addition of any electrolytes and/or surfactants or other dispersing agents be carried out as grinding mill additives during preparation of the coal compact, for two reasons, as follows.
First, the agents serve as grinding aids by maintaining a low slurry viscosity during grinding.
Second, they are immediately available for adsorption on the new surfaces generated during comminuation of the coal. Accordingly, need for later treatment with chemical ion species on the surfaces is minimized or eliminated and saves time, energy, and materials cost.
When the conditions have been satisfied for providing a compact with an Alfred particle size distribution wherein n is between 0.2 and 1.0, and for optimizing the zeta potential, more water is added, as needed to the blend to disperse the particles and produce a desired degree of plasticity or fluidity of the resulting Alfred formual coal-water slurry for transporting the slurry in a pipeline.
At this point two serious problems may arise, which could make the slurry useless for long distance pipeline pumping. These are:
a. the slurry may develop dilatent rheology; and
b. the slurry may be unstable and settle.
Present day coal slurry technology teaches that to overcome these problems, it is necessary to dilute the slurry to approximately 50 wgt. % solids, which dilution separates the particles to minimize particle collision frequency sufficiently to overcome dilatency, and then to pump the slurry in the turbulent regime to avoid settling. It has been found that when the fluid transport velocity falls below the critical Reynolds number into the laminar flow regime, such slurry will exhibit instability and gradually settle out the larger particles. At the use site the prior art coal slurry is dewatered to bring the coal, as nearly as possible, back to its original state of dryness so that it can be burned. Such is the current technolgy in all commerical slurry pipeline systems, including that used in the largest coal pipeline in operation in the U.S. which runs from Black Mesa, Arizona, 273 miles to the Mohave Power Plant at Davis Dam, Nevada.
According to the present invention, it has now been found that the above two problems are avoided provided that a sufficient amount, usually from 5 to 20 wgt %, dry basis, of the coal particles in the slurry are of colloidal size, usually particles of not more than 3 μm size, and further provided that especially the colloidal coal particles are in a deflocculated state. In the present invention, accordingly, preparation of a high solids content, e.g. 60-80 wgt %, slurry which is pumpable for long distances in a pipeline, depends first upon a proper preparation of the size distribution of coal particles in accordance with the Alfred consist formula from the coarsest particles down to colloidal particles of less than about 3 μm size and use of a critical amount of the such particles in the slurry.
It has been found also that to maximize solids content of a coal-water slurry while retaining yield pseudoplastic rheology, all parts, including, broadly, a coarse fraction and a fine fraction, of the particle size distribution of a coal compact must be controlled to provide a substantially non-undulating particle size distribution.
In some cases, depending on the coal and its inherent properties, the desired D L , D S and particle size distribution may be obtained directly by milling the coal, preferably in the presence of a predetermined amount of electrolyte and/or dispersing agent(s), until tests of the grind show that the desired sizes and distribution have been obtained. This is done, for example, as follows:
The particle size distribution or consist, of particles in a sample of the compact from a mill grind of coal particles having a desired D L is determined at grinding intervals for the whole range of particles, preferably in microns. A CPFT plot of log CPFT vs log of particle sizes in μm is then charted in a line plot on a log-log chart. The CPFT chart line then is compared to a selected Alfred formula CPFT chart line having n value preferably in the range of 0.2 to 0.7.
When the test results from the sample show that the desired particle size range and particle size distribution have been attained in accordance with the Alfred CPFT consist formula, the mill can be stopped and the coal compact used directly in preparation of the coal-water slurry by adding carrier water to a desired concentration.
In a coal compact made by this example, the value of n of the CPFT chart line for the mill ground coal compact optimally should be about 0.40 to provide a coal compact having a consist of 100% minus 300 μm (50) mesh having D S of about 0.3 μm and having about 11 wgt. % dry basis, of coal particles of minus 3 μm size. Use of such a mill grind coal compact will result in a nearly ideal, pipeline pumpable, coal-water slurry when further chemically treated if necessary, and mixed with carrier water in accordance with the present invention.
If a coarser pulverized coal can be used directly into a burner, e.g. 40% minus 600 μm (30 mesh), then the value n in the CPFT formula for the coal compact of the above example can be between 0.15 and 0.55, preferably 0.5, with D S =<1.0, preferably about 0.5 μm. Milling then can be carried out to directly obtain a consist of 10 wgt. % particles minus 3 μm. A higher percentage of fines will improve the fluidity of the slurry, but it will also increase the costs of both milling and the dispersing agents required.
It was further found that the coarser the coarse end of the consist of a grind, the more fines are required to optimize fluid properties, and the finer its coarse end, the less fines are required. Stated another way, a "coarser" compact, e.g. all passing 16 mesh, requires a very wide particle size distribution, for example, (D L =1180, D S =<3.0 μm, n=0.1 to 0.4). A "finer" compact, e.g. all passing 400 mesh, requires a narrower distribution, (D L =40 μm, D S =<1.0 μm, n=0.2 to 1.0). Both of these coal compacts or "grinds" will yield consists with 10 wgt. % of particles of (-) 3 μm, but in the finer grinds the (-) 3 μm fraction may vary, and range from 7 to 36 wgt. in the consist.
Pulverized coal (P.C.) as usually commercially ground may be found to form a coal compact with a particle size range which is close to a particular D L and D S desired for preparing a coal-water slurry of the invention. However, the coal particle size distribution of the P. C. may not have the sufficient amount of colloidal sized particles nor the substantially non-undulating particle size distribution of coal particles required for practice of this invention. In such case, it is necessary to further grind the pulverized coal until the sufficient amount of colloidal particles, i.e. at least 5 wgt. %, dry basis, are present, and a consist is obtained in accordance with the Alfred consist formula.
Also, it has been found that such a pulverized coal often can be blended as a coarse fraction with a fines fraction which has a large amount of minus 3 μm particles to prepare a coal compact provided that the blend approximates the Alfred distribution, having an Alfred formula consist. At least 5 wgt. % of all the particles in the resulting blend then should be of colloidal size, usually less than 3 μm in size (SEM). The total amount of fines of colloidal, or of minus 3 μm size, in the blend can range from about 5 to 20 wgt. %, dry basis, and preferably should be about 10 wgt. %. Adding too many fines to the P.C. fraction will increase the viscosity and will reduce the value n of the CPFT chart line of the Alfred formula.
Accordingly, if a given coal cannot be ground in a single milling operation to obtain a particle size distribution conforming to the Alfred CPFT formula chart line, with its n value preferably between 0.3 and 0.5, then a blend of two or more grinds with coarser and finer particle size distributions must be made, or otherwise provided, e.g. using Black Mesa slurry waste, to approximate the desired n value while also maintaining a minimum of 5 wgt % of colloidal particles in the final blend.
Also, in some cases when, due to a pecularity of the grinding characteristics either of a particular coal and/or of a particular milling facility, an unduly undulating particle size distribution is obtained in the coal compact from the milling facility, steps can be taken to provide coarser or finer coal particles to smooth out the particle size distribution at the undulating part or parts of the distribution.
The significance of the colloidal, usually (-) 3 μm size, fraction with regard to pseudoplasticity and dilatency of a slurry is illustrated in FIG. 8 of the drawing. One must consider that monospheres typically pack in an average orthorhombic array at 60.51 volume % solids regardless of size with the particles touching each other.
If a film of semi-rigid water is adsorbed on each particle, then one must consider that the volume percent solids is reduced by moving the particles away from each other by twice the water film thickness (inter-particle spacing, or IPS). As shown in FIG. 8, for particles of size below 3 μm, the adsorbed water film becomes a significant part of the packing volume. FIG. 8 inset further shows that if the interparticle spacing of particles P is equal to or greater than (2-√3) times the particle diameter, then this system can be sheared by merely distorting the rigid water films and not causing particle collisions. This condition would at least avoid dilatency and probably induce yield pseudoplasticity. Therefore, improving the "strength" of the rigid water films of the system by adding advantageous counterions in accordance with above step (ii) of the method of the invention should tend toward true plastic rheology with a yield stress.
The above theory is, of course, distorted by the fact that pulverized coal particles are neither mono nor spheres, and one must work with an actual size distribution of rough, variously shaped particles. Also, there is no simple way of determining precisely how much materialis less than 3 μm in size. However, methods, such as electron microscope measuring techniques, as defined, can be used to make such determinations. In any case, the above concept and step (ii) of ensuring that an adequate amount of advantageous counterions are present in the bound water layer are helpful for obtaining a stable, high solids content slurry having low viscosity and suitable for pumping in a long distance pipeline.
The effect that the presence of a dispersing agent, such as a surfactant, has upon the coal-water slurry to increase its rheological plasticity has also to do with the structure of the bound water film on the colloidal particles in the slurry. Although the dispersing agent affects every particle present, the effect is most important when there are sufficient colloidal sized, i.e. minus 3 μm, particles, present, because the agent influences the particle-particle interactions.
A dispersing agent in a coal-water slurry according to the invention is believed to perform at least three functions, as follows. First, a water soluble dispersing agent which also serves as a wetting agent, such as an organic surfactant, functions and may be necessary and may be used to promote wettability of the coal particles by water. Such an agent may or may not be needed, depending upon the surface chemistry of the coal and the associated electrochemistry of its bound water layers. For example, inherent bed moisture and chemical compounds already present in natural coal deposits may also allow wetting of the ground coal by added water, as discussed above.
Second, a dispersing agent, such as a water soluble surfactant, whether organic or inorganic, functions and may be necessary to promote deflocculation of colloidal and larger sized coal particles in the presence of advantageous electrolytes. According to the DLVO theory (Dejaguim, Landau, Verwey, Overbeek), small monovalent cations such as Na + or K + in proper concentrations will maximize the negative zeta potential of particles, thereby allowing the particles to repulse each other and to slide past one another without bonding. This is the classical concept of deflocculation. Larger, higher valence, cations, such as Ca +2 , Al +3 , and Mg +3 , will tend to reduce the particle charge to zero, allowing flocculation of particles by Vander Waal's forces. Further additions of larger cations can change the polarity of the zeta potential and again increase it. Thus, it is possible for deflocculation to occur at both a negative potential, or at a positive potential. A residual Na + or K + on an organic anionic surfactant which causes wetting therefore, can be a very effective deflocculant.
For practice of the invention, it has been found that a zeta potential at a maximum attainable millivoltage for a particular coal compact in a particular carrier water is undesirable at high solids content, particularly in the range above about 60 wgt. %, for the reason that the yield pseudoplastic rheology of the coal-water slurry may be shifted into a dilatent rheology and become too viscous to be pipeline pumpable. Therefore, zeta potential must be maintained at a near maximum zeta potential as ascertained by millivoltage values obtained relative to maximum attainable millivoltage, substantially as described in the Examples.
Third, the dispersing agent functions in some cases as an electrolyte and is necessary for enhancing pumpability of the coal-water slurry by enhancement or inhibition of the structure of the bound or, semi-rigid water layer. It does this by providing a cation as a counterion for the bound water layer which will affect the yield pseudoplastic index (slope of a plot of log viscosity vs log shear rate) of the mass. Preferably, the cation provided by the agent is NH 4 + , Na + or K + . A counterion, such as Na + , is a structure breaker, whereas a counterion cation, such as Ca +2 , is a structure maker. Therefore, the former are preferably used. The structure making or structure breaking tendencies of each of these counterions is determined by their z/a 2 (valence/ion radius) relationship which increases and decreases entropy, respectively. For further discussion of this principle, see W. G. Lawrence, Chapter in Clay Water Systems, W. G. Lawrence, ed. N.Y.S. College of Ceramics, Alfred, N.Y. (1965). The phenomenon is believed analogous to lowering the melting point of glass by adding alkali to the glass composition. Therefore, by using the DLVO theory in practice of the invention, it has been found that addition of a sufficient amount of an advantageous electrolyte, such as an ammonium or alkali metal base, to a coal-water slurry has been found effective to increase deflocculation of the slurry and thereby to improve its yield pseudoplasticity, whereas addition of an alkaline earth metal base has been found to be less or completely ineffective.
The above steps (i), (ii), and (iii) and the related conditions are taken into consideration for the practice of this invention in order to obtain a stable yield pseudoplastic, high solids content, low viscosity slurry. For example,
1. The consist, or particle size distribution, of coal particles of a coal compact to be used to make the coal-water slurry of the invention must be in accordance with the Alfred consist formula. ##EQU6## as defined above, and as may be represented in a linear plot thereof on a log-log chart and have n value in a range determined from D L and D S , substantially as illustrated in FIG. 12 and Tables 1-4. When at least 10 wgt. % of the particles are (-) 3 μm, pulverized coal (P.C.) at 50 to 70 wgt. % minus 200 mesh (-75 μm) can be used to make coal compact to be used in making coal-water slurry by adding additional fines to the P.C. to raise the total fraction of (-) 3 μm particles present in the P.C. grind to at least 5 wgt. %, and the total distribution to that according to the Alfred consist formula. Any such bimodal blends usually may advantageously be used. Rod milled commercial P.C. coal usually will not contain sufficient fines, and therefore, blending of ball milled fines with such grind of coal may be necessary to obtain a consist in accordance with the Alfred formula.
2. The minus 3 μm fraction is a colloidal fraction and should be between 5 and 20 wgt. %, dry basis, of total particle weight of the coal, with at least 10 wgt. %, preferably 10 to 20 wgt. %, the most desirable.
3. Either the coal must be naturally wetted by its natural surface oxidation or other chemical state, or water soluble surfactants, such as the electrolytes and/or dispersing agent(s) discussed herein, must be added to effect wetting. Between 0.05 and 2 wgt. % of organic or inorganic surfactants of wetting agent capability based on total weight of coal may be necessary, or both types of surfactants may be necessary together, in an amount totaling up to 4 wgt. %, dry basis.
4. The repulsive electrical zeta potential of the colloidal coal particles must be raised to amillivoltage just short of maximum, as discussed above, by addition of an effective amount of zeta potential enhancing dispersingagent to obtain yield stress needed to retain yield pseudoplasticity. The polarity of the zeta potential may be either positive or negative depending on the ions present in the coal particle surface, and in the bound water layer, but usually, and preferably, will be negative.
The kind of water used as carrier water may be any available water, such as mine, well, river, or lake water or desalinated ocean water having a sufficiently low mineral salt content such that the electrochemistry of the bound water layer and carrier water interface can be controlled in accordance with the invention and corrosion of milling facilities, pipelines and furnaces will be minimized and controllable.
The kind of coal used for practice of the invention is not critical. Coals found in the United States, particularly low volatile bituminous coals, from West Virginia, Kentucky, Ohio, Arizona or Montana fields, have been used. However, anthracite, semi-anthracite, medium and high-volatile bituminous, sub-bituminous and lignite coals all may advantageously be used to practice the invention.
The coal used to prepare the coal-water slurry can be obtained in finely-divided form by cleaning and pulverizing larger sized coal to the desired particle sizes. The coal content of the pulverized coal can be enriched by use of known clay and mineral separation processes to obtain a coal of low ash content, e.g. under 5 wgt. %. However, the ash content of the coal may be higher or lower than 5 wgt. %, e.g. from 0% to 20 wgt. % while permitting the benefits of the invention to be obtained.
The coal for use in the process can be obtained in a dry or wet form and mixed with water to form a coal-water slurry. Preferably, the coal for making a fine particle sized fraction is wet milled in known ways to prevent dust and explosion hazards, while adding electrolyte and/or dispersing agent(s) to the water in accordance with this invention. The wet milled coal fraction can be milled with all the water or it can be mixed with sufficient additional water to make a slurry which will be readily pumpable in a pipeline, when it further is mixed with a coarser particle sized pulverized coal fraction to form a yield pseudoplastic coal-water slurry according to the invention. Usually, the water content of the final coal-water slurry product will be in the range of about 20% to 55% by weight of slurry. Preferably, the water content will be from 20% to 45% by weight. The total amount of water must, however, be at least that needed to transport the Alfred coal-water slurry in a pipeline to its destination if the slurry is to be transported in a pipeline. Bulk shipments of the Alfred coal-water slurry can also be made. Further, the Alfred coal compact can be compressed to make a high density coal mass with minimum fluid content particularly in areas where water is scarce and pipeline transport is not feasible.
In carrying out the invention, much work has been expended grinding and blending coals from different fields. As a result of this work it has been found that West Virginia bituminous coal grinds very easily to a particle size distribution in accordance with the Alfred CPFT formula. This ground coal then can be deflocculated using 0.1% Lomar D and NaOH as an electrolyte-dispersing agent combination.
Black Mesa coal is a wetern United States sub-bituminous type coal from Arizona deposits having a dry specific gravity of 1.45 and an equilibrium moisture of about 11 percent. Its ash content is about 10 percent. The consist of coal of typical Black Mesa pipeline coal-water slurry is essentially all minus 14 mesh (1400 μm)×18 to 20% passing 325 mesh (-44 μm). Solids concentration of the Black Mesa slurry averages 48 percent by weight of the above coal.
While it has been found that Black Mesa coal is considerably more difficult to grind than is West Virginia coal, it has also been found that when a coal compact is prepared from the Black Mesa coal to have a consist according to the Alfred consist formula, much less electrolyte and/or dispersing agent(s) is required to provide yield pseudoplastic fluidity.
The dispersing agents used in preparing the Alfred formula coal-water slurry can be any synthetic or natural materials having wetting agent properties and which will maximize the zeta potential of the coal particles to near maximum zeta potential as herein described. For reasons discussed above, the dispersing agent effective for use for a particular coal will be selected on the basis of the surface chemistry of the coal particles. Accordingly, the dispersing agent, preferably a surfactant, will usually be a surfactant which in some cases will be an anionic surfactant, in other cases a cationic surfactant, and in some cases even a non-ionic surfactant. Thus, preferred dispersing agent can be an organic or inorganic material. Preferably the material is an anionic surfactant when the coal is a bituminous coal from a West Virginia, Kentucky, Ohio, or other Appalachian area coal field, and when the coal is a bituminous or sub-bituminous coal from an Arizona or other Western area coal field.
Examples of anionic organic surfactants which have been found particularly advantageous for providing yield pseudoplastic rheological properties to Alfred formula coal-water slurries, particularly those containing about 60 to 80 weight % of West Virginia or Black Mesa, Ariz. coal, are shown in Table 5. In some cases, mixtures of two or more of these surfactants beneficially can be used.
Most preferably the deflocculating agent is selected from the group of anionic organic surfactants consisting of:
(i) 2-ethylhexyl polyphosphoric ester acid anhydride and its potassium salt,
(ii) complex organic polyphosphoric ester acid anhydride and its potassium salt,
(iii) condensed mononaphthalene sulfonic acid and its sodium and ammonium salts, and
(iv) mixtures thereof.
TABLE 5______________________________________Anionic Organic Surfactant Tradename Form % conc.______________________________________2-ethylhexyl polyphosphoric Strodex Liquid 100ester acid anhydride MO-100Potasssium Salt of Strodex Paste 70MO-100 MOK-70Complex organic polyphos- Strodex Liquid 100phoric ester acid MR-100anhydrideComplex organic polyphos- Strodex Liquid 100phoric ester acid SE-100anhydrideComplex organic polyphos- Strodex Liquid 100phoric ester acid P-100anhydrideComplex organic polyphos- Strodex Liquid 90phoric ester acid PK-90anhydridePotassium salt of complex Strodex Liquid 98organic polyacid anhydride MRK-98Potassium salt of complex Strodex Liquid 50organic polyacid anhydride SEK-50Potassium salt of complex Strodex Liquid 58organic polyacid anhydride PSK-58Potassium salt of complex Strodex Liquid 85organic polyacid anhydride V-8Sodium salt of an alkyl Lomar D Powder 86-90mono naphthalene sulfonic Lomar NCOacid Lomar PWSodium salt of an alkyl Lomar LS Powder 95mono naphthalene sulfonicacidAmmonia salt of an alkyl Lomar PWA Powder 89mono naphthalene sulfonicacidSolution of sodium salt Lomar PL Liquid 45of an alkyl mononaphthalene sulfonic acid______________________________________
Strodex is a trademark of Dexter Chemical Corporation.
Lomar is a trademark of Diamond Shamrock Process Chemicals, Inc.
Other suitable anionic organic surfactants can be selected for screening from those listed in McCutcheon's, Detergents & Emulsifiers North American, 1976 annual edition, McCutcheon Division, MC Publishing Co., Ridgewood, N.J. 07451 and in Encyclopedia of Surface-Active Agents, J. P. Sisley, Chemical Publishing Company, Inc., New York (1964, Vol II). Those found to be effective in the environment of a particular coal and its carrier water can then be used for preparing Alfred formula coal-water slurry.
While the use of the sodium and ammonium salts of condensed mononaphthalene sulfonic acid are preferably used, it is to be understood that the condensed mononaphthalene sulfonic acid can be used with the addition of sodium or ammonium alkali to form the corresponding sodium or ammonium salt of that acid in situ.
In contrast to the tested and selected anionic organic surfactants useful in the practice of the invention, many organic and inorganic compounds were tested and found unsuitable as effective deflocculants for forming a pipeline pumpable rheologically plastic coal-water slurry, as disclosed in copending application Ser. No. 957,166 filed Nov. 2, 1978, which disclosure is incorporated herein by reference.
Referring specifically to the electrolytes useful in practice of the invention, some alkali metal inorganic compounds were found effective as electrolytes to enhance the dispersing activity of the screened and selected anionic organic surfactants in the presence of West Virginia and Arizona coals. Alkali metal carbonate, hydroxide or silicate of sodium or potassium are particularly effective. Preferably, the inorganic compound is at least one of K 2 CO 3 , NaOH, and Na 2 SiO 3 .9H 2 O. In the case of Arizona coal, an alkali metal hydroxide, carbonate, or silicate may be used even in the absence of an organic surfactant to adequately deflocculate the coal-water slurry containing at least 5% of minus 3 μm particles. The reason for this may be that the Arizona coal is already effectively wetted by natural surfactants, and addition of the inorganic compound serves to activate and enhance the dispersing effect of the natural material. When used in the presence of a synthetic surfactant, the alkali material preferably is added before the anionic organic surfactant is added to the slurry, but this order is not essential. Mixtures of the above alkali materials also can be used. It is to be understood that the combination of electrolyte and dispersing agent is used to bring the zeta potential of the coal particles to near maximum zeta potential in accordance with the invention as discussed above, and to disperse the coal particles, especially those of colloidal size.
The amount of dispersing agents used can be determined by routine experiments to screen and select agents effective for a particular Alfred formula consist of coal and carrier water to convert it to a pipeline pumpable coal-water slurry having the coal particles at near maximum zeta potential. The amount will vary depending upon such factors as the concentration of the coal in the slurry, the particle size and particle size distribution, the amount of ash, i.e. clays and other minerals present, the temperature of the slurry, the pH, the original zeta potential of the particles, and the particular electrolyte and/or dispersing agent(s), e.g. a deflocculant anionic organic surfactant, and its concentration. In general, the dispersing agent, e.g. the above deflocculant, is present in the slurry at from 0.1 to 0.7 weight percent based on the weight of dry coal. Procedurally, in determining the amount of a specific dispersing agent needed, a series of measurements are made of viscosities versus shear rates versus zeta potential as described in Ex. 1 for a series of coal-water slurries containing a range of amounts of a particular dispersing agent for a constant amount of coal-water slurry. The data can be plotted as shown in FIGS. 2-5 and 13 and used as a guide to the optimum quantities of that agent to use to obtain near maximum zeta potential. The coordinate of the chart at which the viscosity and/or zeta potential is not decreased significantly by adding more agent is selected as an indication of the optimum quantity at maximum zeta potential, and the amount is read from the base line of the chart. The viscosity and amount read from the titrationchart (FIGS. 2-5 and 13) is then compared with an equivalent chart showing a correlation among viscosity amount ard maximum zeta potential (FIG. 2). An amount of electrolyte and/or dispersing agent(s) required to provide a near maximum zeta potential and a selected viscosity is then usedto make the Alfred coal-water slurry. For example, in FIG. 2 near maximum potential of (-) 50 to (-) 63.2 mv were obtained with 0.4 to 0.5 wgt. % of dispersing agent in a 55 wgt. % Alfred coal-water slurry.
Other methods for selecting the type and amount of dispersing agent needed to obtain a near maximum zeta potential in a coal consist made according to this invention will be apparent to those skilled in the coal-water slurry art.
FIG. 3 shows semi-logarithmic plots of deflocculation curves obtained with varying amounts of sodium salt of condensed mono naphthalene sulfonic acid (Lomar PWA and Lomar PW) and of the ammonia salt of said sulfonic acid (Lomar D) dispersed in carrier water in parts of surfactant per 100 parts of ball milled W. Virginia coal (dry basis, 100 wgt. % 325 mesh (-) 45 ηm) and having 10 wgt. % of particles minus 3 μm) in a coal-water-anionic organic surfactant slurry containing 55 wgt. % of coal. From this data it is concluded that rheological plasticity will be provided and retained at near maximum zeta potential when about 0.4 to 0.7 gm of the anionic surfactant is present per 100 gms of dry W. Virginia coal in a dispersed coal-water slurry containing 55 wgt. % of coal with the particle size distribution according to the Alfred formula.
FIG. 4 similarly shows semi-logarithmic plots of deflocculation curves obtained with varying amounts of potassium salt of complex organic polyphosphate ester acid anhydride (Strodex V8 and Strodex PK-90) and of Hydrodyne-Aquadyne, a mixture of non-ionic wetting agents, dispersed in water in ml. of surfactant per 100 parts of ball milled West Virginia coal (dry basis, 100 wgt. % minus 325 mesh ((-) 45 μm), 10 wgt. % minus 3 μm) in a coal-water-anionic organic surfactant slurry containing 55 wgt. % of West Virginia coal slurry. From this data it is concluded that rheological plasticity will be provided and retained when about 1 to 2 mls of liquid anionic surfactant or of non-ionic wetting agents are present per 100 gms of dry coal in a dispersed coal slurry containing 55 wgt. % of coal with the particle size distribution according to the Alfred formula.
Quantities of other dispersing agents to use can be determined similarly. In general, the flow behavior of the slurry is controlled below the solids content or the dispersing agent addition level at which dilatency could begin to occur i.e. below the level at which viscosity increases as shear rate increases. Pumpability of the coal-water slurry is optimum under such rheological conditions but would decrease rapidly as dilatency is approached.
As discussed above, certain electrolytes, such as alkali inorganic compounds, can be added to the slurry to enhance the rheological plasticity of the slurry in the presence of an anionic organic surfactant. The effects of the addition of NaOH to 55% coal-water slurry wherein the coal particles were 100 wgt. % minus 325 mesh and 10 wgt. % minus 3 μm and containing varying amounts of an anionic organic surfactant, Lomar D, are shown in Table 6.
TABLE 6______________________________________ Brookfield Viscosity, cpsNaOH, gms Lomar D at 60 rpm______________________________________0.4 1.15 4501.2 0.75 1752.0 0.80 450______________________________________
Table 6 shows a ratio of NaOH to Lomar D of 1.2:0.75 to provide an optimum low Brookfield viscosity of 176 cps at 60 rpm. From this data it is concluded that rheological plasticity will be provided and retained when the above ratio of amounts of NaOH to Lomar D are used to prepare an Alfred formula coal-water slurry.
FIG. 5 shows deflocculation curves obtained using West Virginia bituminous coal-water slurry (wherein the coal particles were ball milled to provide 100 wgt. % minus 325 mesh and 10 wgt. % minus 3 μm), 67.4 wgt. % solids, deflocculated with from about 0.75 to 1.05 gms of Lomar D per 100 parts of coal (dry basis) and varying amounts of NaOH and K 2 CO 3 . The alkali materials were prepared as 10N solutions in water and added in various amounts by volume to the slurry. In FIG. 5, 0=0 ml; 1N=1 ml of 10N-NaOH; 3N=3 ml 10N-NaOH; 5N=5 ml 10N-NaOH; and 1K=1 ml 10N-K 2 CO 3 . It is concluded from the deflocculation curves that the use of 3 ml of 10N-NaOH should provide optimum low viscosity at about 0.75 gm of Lomar D per 100 gms of coal in Alfred formula coal-water slurry. As each ml of 10N-NaOH equals 0.4 gm of NaOH, dry basis, and each ml of 10N-K equals 0.69 gm of K 2 CO 3 , the amount of alkali present in the slurries from which the data shown in the curves was obtained ranged from 0.4 to 2.0 gm per 100 gm of coal.
EXAMPLE 1 - PROCEDURE FOR SCREENING AND SELECTING DISPERSING AGENTS FOR USE IN MAKING ALFRED FORMULA COAL WATER SLURRY
A surfactant or combination of surfactants effective for use in practicing the invention may be found by either of the two following methods (a) or (b) as applied in (c).
(a) Zeta potential measurement.
In general, a sample of coal is ground in a laboratory size porcelain ball mill with porcelain balls in water at 30 wgt. % solids for approximately 24 hours to insure that all the particles are <10 μm. Small samples of this larger sample are then prepared in a known way by placing them in a vessel equipped with a stirrer with a sample of water to be used as a carrier in the Alfred formula coal-water slurry. Various acidic and basic salts are then added in incremental amounts to vary the ph, and various concentrations of various candidate dispersing agent organic surfactants likewise are added in incremental amounts (e.g. grams per gram coal, both dry basis), alone or in combinations of two or more. These samples are then evaluated in any electrophoretic mobility, electrosomosis, or streaming potential apparatus to measure electrical potentials, from which the zeta potential is calculated in a known way. Plots of zeta potential vs. pH vs. concentration may then be made to indicate candidate surfactants, or combinations thereof to be used to produce the optimum dispersion of coal particles in the carrier water below the amount at which dilatency may be reached. A Pen Kem System 3000 apparatus was used in the determination described and can process 40 samples in about 6 hours.
(b) Alternate method for estimating equivalent zeta potential.
A large sample of coal is ground in water as described in (a) above at 50 wgt. % solids for about 2 to 4 hours to produce a slurry. This slurry is found to have a Brookfield viscosity at 30 rpm of about 10,000 cps.
Smaller samples, about 500 ml, of this slurry are then deflocculated by adding various candidate dispersing agent surfactants and surfactant combinations to the sample of slurry, as above, dry or, preferably, in solution, dropwise, blending gently, and then measuring the viscosity at some constant shear rate (e.g., using a Brookfield LVT viscometer at 30 rpm). A surfactant system which is found to produce an acceptably low, preferably the lowest, viscosity at the lowest amount, e.g. in wgt. % of addition on a dry coal basis is thereby identified as the most effective surfactant.
(c) Reference may now be made to FIGS. 2 and 13, which summarize the results obtained in screening tests carried out in accordance with (a) and (b) of this example using coal from an Eastern Kentucky mine at 55 wgt. concentration and an anionic organic surfactant, sodium salt of an alkyl nono naphthalene sulfonic acid (Lomar D), as a deflocculant dispersing agent.
Referring to FIG. 13, and its inset, it is seen that as the amount of deflocculant was increased from zero to 0.945 wgt. %, the zeta potential increased gradually with each incremental addition of Lomar D from (-) 15.4 mv at 0.079 wgt. % to (-) 70.2 mv at 0.945%. Simultaneously, as the shear rate (rpm) was increased during the time of presence of each incremental amount, the Brookfield viscosity is seen to decrease until it reaches a minimum value at 30 rpm, while the rheology of the system is seen to change from pseuodoplastic to dilatent at a rate between 30 and 60 rpm.
Referring now to FIG. 2, it is seen that the chart line formed from the data from the inset of FIG. 13 forms a distinctive curve. The curve shows that as zeta potential increases from (-) 15.4 to (-) 67.7 mv, the Brookfield viscosity falls from about 7000 cps to about 80 cps, and then levels off at about 75 cps at (-) 70.2 mv. From this data and chart, it is indicated that near maximum zeta potential can be identified as being about (-) 63.2 μm, and the amount of Lomar D to use to make an Alfred formula coal-water slurry will be about 0.5 wgt. % based on the weight of coal, both dry basis. To be on the safer side, the amount of dispersing agent can be decreased slightly, e.g. to about 0.45 wgt. %, or less.
While the above methods have been described using a preferred dispersing agent, Lomar D, it will be clear to one skilled in the art that any material can be similarly screened to find advantageous materials which can be used to practice the invention.
EXAMPLE 2--PREPARATION OF COAL SAMPLES FOR SIZE MEASUREMENTS
(a) Sieve analysis.
Although any standard procedure may be used to measure particle sizes of coal particles from a coal and then to calculate the particle size distribution, the procedure used in obtaining data discussed herein will be described.
A weighed sample, e.g. 50 grams dry wgt. of coal is dispersed in 400 ml of carrier water containing 1.0 wgt. % Lomar D based on a weight of coal, dry basis, and the slurry is mixed for 10 minutes with a Hamilton Beach mixer. The sample is then allowed to stand quiescent for 4 hours, or preferably, overnight. (This step usually is not necessary if the slurry was milled with surfactant).
The sample is then remixed very briefly. is poured slowly on a stack of tared U.S. Standard sieves over a large vessel. The sample is carefully washed with running water through the top sieve with the rest of the stack intact until all sievable material on that sieve is washed through the sieve into the underlying sieves. The top sieve is then removed and each sieve in the stack, as it becomes the top sieve, is successively washed and removed until each sieve has been washed. The sieves are then dried in a dryer at 105° C. and the residue on each is weighed in a known way.
The sample which passed through the finest sieve was collected as a dilute slurry in a container for Sedigraph analysis.
(b) Sedigraph analysis.
The sample finer than the smallest sieve size is carefully stirred and a representative sample (about 200 ml) is taken for analysis. The rest may be discarded.
About 2 eyedroppers of the dilute slurry is further diluted in 30 ml of distilled water with 4 drops of Lomar D added. This sample is stirred overnight with a magnetic stirrer. Measurement is then made with the Sedigraph 5500L.
The Sedigraph 5500L uses photo extinction to measure particles. It essentially measures projected shadows and due to diffraction effects around particles the data must be converted to mass-wgt.-%-finer-than. The data from the sieve and Sedigraph is combined with the D S data obtained by SEM and used to prepare a CPFT chart.
EXAMPLE 3--PREPARATION OF BIMODAL BLENDED 75 WGT. % COAL-WATER SLURRY, D L =150 μm
A 75 wgt. % coal-water slurry hereof is prepared using coal from the Black Mesa mine, as follows. A fine (F.G.) grind portion is prepared by adding to a ball mill 30 parts of carrier water, about 22.5 parts of pulverized coal (P.C.) and further adding, as electrolyte and dispersing agents, 0.075 parts of anionic surfactant, preferably Lomar D, and 0.075 parts of NaOH. The mixture is ball milled until the particle size distribution is about 45 wgt. % finer than 3 μm. Also, about 52.5 parts of dry pulverized coal (P.C.) are milled until the coal has a particle size distribution in accordance with the Alfred consist formula where DL is 150 μm (100 mesh), D S is <0.7 μm, and n is 0.8, as defined above, to obtain a pulverized coal (P.C.) fraction which is about 78 wgt. % (-) 79 μm. A sufficient amount (47.35 parts) of the P.C. fraction is then added to the fine grind coal fraction to form the final 75 wgt. % coal-water slurry having an Alfred formula consist of 150 μm×0.2 μm with about 17.5 wgt. % minus 3 μm. The total amount of electrolyte and dispersing agent(s) used is predetermined by laboratory tests as described herein. It is effective to bring the entire compact of pulverized coal particles to near maximum zeta potential, and also, to maintain the particles in dispersed, or deflocculated, form in the carrier water of the slurry during pipeline pumping storage and pumping to an atomizer of a coal-water slurry burner or to other use means.
The above method can easily be carried out whether using monomodal or multimodal distributions of particle sizes. For a monomodal distribution the electrolyte and dispersing agent preferably are added to the carrier water before it enters the pulverizing mill with the coal. The coal is then ground in the presence of these agents. For multimodal distributions the deflocculant dispersing agent preferably is added in water asdescribed above, while grinding the fine fraction, and no dispersing agent needs to be added to the coarse pulverized (P.C.) fractions. The coarse dry P.C. fraction can then be added to the deflocculated F.G. fraction, as described above.
If a coal cleaning process including use of a filter press to recover solids is incorporated in the process, coarse P.C. grind having a coarse fraction consist suitable for preparing Alfred formula compact is first cleaned, then flocculated using appropriate flocculating chemicals prior to filter pressing and dewatering the coal, which removes these chemicals. An appropriate percentage of P.C. filter cake is then fine ground in the presence of all the deflocculant added as required to prepare the F.G. fraction. The resulting fine ground deflocculated slurry is then blended with an appropriate percentage of the P.C. filter cake in a fine blunger or mixing tank to obtain Alfred formula coal-water slurry ready for pipeline pumping or storage or for burning or otherwise using the coal-water slurry.
EXAMPLE 4--INTEGRATED PROCESS WITH DEASHING AND BLENDING D L =300 μm.
The practice of the invention in an integrated process for plant scale operation with de-ashing of West Virginia coal will now be described with reference to FIGS. 6 and 7 of the drawing.
Bituminous coal from West Virginia, containing about 21% ash as mined or washed is introduced into a crusher 1 wherein it is crushed to about 2" size or less. The term "Ash" is used herein to define non-combustible content of the coal, such as clay and Various minerals. The crushed coal is charged into a mill 2, preferably a ball mill, where it is wet milled to a particle size of about 70%(-)200 mesh ((-)75 μm) with about 7% (-) 3 μm to provide a coarse fraction of coal particles suitable for preparing a coal compact in accordance with the Alfred consist formula with D L =300 μm, D S =<1.0 μm and n=0.5, substantially as shown in FIG. 11, when mixed with the fine grind portion made as described later herein.
The particles of coarse milled coal are then charged to a slurry tank 3 containing carrier water in an amount sufficient to maintain a solids content of about 10% by weight. The pH of the mass in tank 3 is maintained at a pH of 10 or higher by addition of a solution of NaOH to cause deflocculation and separation of ash materials. Tank 3 is provided with a high intensity agitator 4 to effect dispersion of all particles. After about 20 minutes agitation, the slurry is continuously pumped by pump 3a through line 7 through the hydrocyclone 5 and hence back to tank 3. The hydrocyclone 5 removes the higher specific gravity minerals, preferably flocculated, and delivers them to scrap or reprocessing. After a suitable time of cycling the slurry through the hydrocyclone to maximize ash removal, the valve 3B is closed and valve 3C opened to filter press 6 to filter the batch from tank 3. Filtrate from filter press 6 is recycled to tank 3. The pH of the water is adjusted by addition of a solution of caustic soda (NaOH). The partially ash-free coal thus obtained contains from about 0.5 to 10 wgt. % of ash. Treatment of the coal in tank 3 is, however, beneficial to remove at least gross amounts of the ash content of the coal, thereby increasing the net btu value of the coal-water slurry.
A minor fraction of the filter cake from filter 6 containing filtered coal and about 25 wgt. % water is discharged to a second slurry tank 8 where the cake may be diluted with water from line 8a, if water is needed and is agitated by means of a low speed agitator 9a operated as in tank 3. The filter cake is dispersed in tank 8 with sufficient water present to later make a final coal-water slurry of about 75 wgt. % solids after adding a first predetermined amount of deflocculant, further milling this minor fraction of coal to a fine grind and blending it with a major fraction of filtered coal from filter press 6 in a third slurry tank 14. The coal-water slurry from tank 8 is discharged through line 15 into line 16 from which it is fed into lines 17 and 18 leading to ball mills 19 and 20. A final predetermined amount of a solution of mixed deflocculants, usually making a total amount providing about 0.7 wgt. % of Lomar D and 0.7 wgt. % of NaOH and usually sufficient to adjust the zeta potential of the particles to near maximum zeta potential and to disperse the particles, based on the total amount of dry coal in the final coal-water slurry to be made in tank 14, is added to the coal-water slurries in ball mills 19 and 20. The ball mills preferably are steel and are loaded with steel balls. The coal is milled to a fine grind about 95 wgt. % (-) 40 μm×about 10 wgt. % (-) 3 μm. The milled, fine grind coal is discharged from ball mills 19 and 20 through lines 24 and 25 into tank 14 where it is blended and agitated by means of agitator 9 with the major fraction of de-ashed coal from filter press 6. The coarse and fine grind coals are blended in proportions such that the blend has 75 wgt. % of coal, dry basis, and the coal particles have a substantially non-undulating Alfred formula coal consist having about 10 wgt. % of coal particles (-) 3 μm and the particles have a particle size range of about 300 μm×0.1 μm. The resulting final coal-water slurry product is a pipeline pumpable 75 wgt. % low viscosity Alfred formula coal-water slurry usually having a Brookfield viscosity of about 1000 to 2000 cps at 60 rpms.
The deflocculated yield pseudoplastic coal-water slurry is discharged from tank 14 to a storage tank 10. Successive charges of the slurry are blended continuously in tank 10, preferably by pumping it continuously through a recycle pipeline 11 leading from the bottom of tank 10 to the top of tank 10. Uniformity of the slurry is thus maintained and provides slurry of a substantially uniform btu content. The blended Alfred formula coal-water slurry is pumped from storage tank 10 through pipeline 27, which may be a short pipeline or a long distance pipeline, and is fed into an atomizer burner 12 of a furnace 13 used to generate heat energy to heat water in a steam boiler. Details of a typical atomizer burner for burning a coal-water-anionic organic surfactant are shown in FIG. 7.
Aqueous treatment of the coal for ash removal, deflocculation, and concentration also provides a suitable vehicle for sulfur removal. The amount of deflocculant or of a mixture of deflocculants, such as the anionic organic surfactant and NaOH, which must be used to obtain the benefits and advantages of the invention using the Alfred formula consist can be readily predetermined in accordance with the procedures described in Examples 1-3.
EXAMPLE 5 OF INTEGRATED PROCESS, WITH BLENDING BUT WITHOUT DEASHING, D L =425 μm
Practice of the invention in an integrated process without deashing for plant scale operation with Black Mesa, Ariz., coal will now be described with further reference to FIGS. 6 and 7 of the drawing.
Sub-bituminous coal from Black Mesa coal fields containing an average ash content of 9.8 wgt. % (range of 6.5% to 17%) as mined or washed is introduced into crusher 1 and crushed to 2" size or less. The crushed coal is milled in about 10 wgt. % of carrier water to prepare pulverized coal (P.C.) particles 50 to 70 wgt. % substantially all finer than 425 μm and suitable for preparing a coal consist in accordance with the Alfred formula with D L =425 μm, D S =<1.0, and n=about 0.45, substantially as shown in FIG. 11, when mixed with the fine milled portion made as described later herein. The P.C. coal is discharged from mill 2 through line 16. Because of the low ash content of Black Mesa coal, it usually will not be necessary or or desirable to de-ash the coal.
A minor fraction of the milled (P.C.) coal from line 16 is fed through lines 17 and 18 into ball mills 19 and 20. A solution of part of a predetermined amount of deflocculant materials is added to ball mills 19 and 20 and additional carrier water is added to each mill, for example, from line 8a, through tank 8, line 15 and lines 17 and 18, respectively. The amount of water added will depend on the amount of water present in the pulverized coal from ball mill 2. A major fraction of pulverized coal is fed through lines 16, 17, 18, 25 and 26 to tank 14. The total amount of minor and major fractions of pulverized coal will amount to a final amount of coal which when diluted with the water added to ball mills 19 and 20 will make up to a 7.5 wgt. % coal-water slurry and can readily be calculated. The rest of the predetermined amount of deflocculants needed to provide the colloidal particles of coal in the coal-water slurry with near maximum zeta potential is added to the ball mills 19 and 20 to provide a mixture of 1.0 wgt. % of Strodex V8 and 1.0 wgt. % NaOH, based on the total weight of dry coal in the final coal-water slurry to be made up in tank 14. The necessary amount of water needed in mills 19 and 20 is added also. The mills are run for about 30 hours at 60 rpm or until a fine grind of Black Mesa coal is obtained which is 99 wgt. % minus 10 μm and about 46 wgt. % minus 3 μm. The milled, fine grind coal-water slurry is then discharged into tank 14 where it is blended with the major fraction of pulverized coal in proportions such that the blend has 75 wgt. % of coal, dry basis, and the coal particles have a substantially non-undulating coal consist in accordance with the Alfred formula as defined above with n=about 0.45 and particle size of about 7 wgt. % of coal particles minus 3 μm. The resulting Alfred formula coal-water slurry usually will have a Brookfield viscosity of about 4000 cps at 60 rpm, substantially as shown in FIG. 1, A.
The deflocculated, yield pseudoplastic 75 wgt. % coal-water slurry is discharged into tank 10, where it is blended as described in Example 4, and pumped to a use site in short or long distance pipelines for burning in an atomizer burner furnace as described in Example 4.
EXAMPLE 6--INTEGRATED PROCESS, WITH OR WITHOUT DEASHING WITH BLENDING, D L =75 μm
Using substantially the same method as described in Examples 4 and 5, West Virginia or Eastern Kentucky coal, can be milled and dispersed in carrier water to prepare pipeline pumpable Alfred formula coal-water slurry with from about 65 to 77 wgt. % coal, with D L =75 μm, D S =<1.0 μm, and n=0.2 to 0.8 with about 6.6 to 29.3 wgt. % of particles of (-) 3 μm. The slurry will usually have a Brookfield viscosity at 60 rpm of from 300 to 2400 cps.
EXAMPLE 7--INTEGRATED PROCESS, WITHOUT BLENDING, D L =300 μm
In view of the finding that West Virginia coal can be milled directly to prepare an Alfred formula coal compact, this coal usually can be milled and used to make coal-water slurry without need to make a blend from a coarse fraction and a fine fraction as was done in Examples 4-6.
Referring to FIG. 6, 75 wgt. % Alfred formula coal-water slurry having an Alfred formula consist with D L =300, D S =<1.0 and n=0.2 to 0.6, substantially as shown in FIG. 12, can be made as follows:
Crushed coal is charged into mill 2 and wet milled to a particle size of about 50 wgt. % (-) 200 mesh ((-) 75 μm). The coarse grind is discharged through line 16 into ball mill 19 or 20, alternately or simultaneously, as desired. Predetermined total amounts of electrolyte and/or dispersing agent(s), e.g. 1.0 wgt. % of Lomar D and 1.0 wgt. % of NaOH, are added to each of mill 19 and/or 20 as needed from deflocculant tank 21. The coal is then milled in mills 19 and/or 20 until a sample shows that the D L , D S and n values recited above have been attained and that there are at least 5 wgt. % of particles of (-) 3 μm present. Usually the amount of (-) 3 μm particles will be from about 20.5 wgt. % at n=0.2 to about 5.0 wgt. % at n=0.6. The coal-water slurry is tested to confirm that the zeta potential is near maximum zeta potential (e.g. about (-) 50 mv as shown in FIG. 2), and that the Brookfield viscosity is about 1000-1500 cps. The slurry is then discharged into tank 14 for blending of batches. The slurry can be stored in tank 10 and charged from there into the atomizer burner 12 for burning.
EXAMPLE 8--INTEGRATED PROCESS, WITHOUT BLENDING, WITH DEASHING, D L =300 μm
If the West Virginia coal is to be used in a deashed form, the above process can be modified by discharging the 50 wgt. % (-) 200 mesh coal from mill 2 into tank 3 for deashing substantially as described in connection with Example 4. The deashed filter cake from filter press 6 can then be charged to tank 8 for dilution with carrier water and transferred to mills 19 and/or 20 as discussed above for further milling and deflocculation to form the Alfred formula coal-water slurry having the properties as described above.
EXAMPLE 9--INTEGRATED PROCESS--DIRECT MILLING WITHOUT DEASHING, D L ≦1180 μm
In a variation of Example 8, crushed coal could be directly charged into ball mills 19 and 20 by means of charge lines (not shown) leading from the crusher to the ball mills. The electrolyte and/or dispersing agent then can be added directly into ball mills 19 and 20 in the predetermined total amounts with additional carrier water as described in Example 8 and milling carried out to obtain Alfred formula coal-water slurry with D L ≦1180 um. The finished slurry can then be further handled, as described above, in tanks 14 and 10 and burner 12.
Net heat content of the Alfred formula 75 wgt. % coal-water slurries of the above compositions made according to the processes of Examples 1-9 are calculated to be about 105,000 btu/gallon of slurry when burned in the atomizer of a gas supported burner, compared to fuel oil which provides about 130,000 btu/gallon.
The flame produced by the burning of the coal slurry can be radiation stabilized, although it may be possible for self-stabilization to occur at about 75% solids content in a properly designed burner.
Cost calculations which have been made show that Alfred coal-water slurry of the invention can be produced in large quantities to make the slurry competitive with oil on an equivalent heating value basis.
Although the invention has been described in relation to use of the Alfred formula coal-water slurry for heat generation by direct combustion, it is also intended that the slurry of the invention be used in coal gasification or liquification processes to provide fuel gases and other coal byproducts. Besides being useful in conventional heat generating systems, this coal-water slurry may provide unique properties for use in MHD generators (magneto-hydro-dynamic) in as much as the slurry can be prepared to contain alkali ions needed in the combustion process in such generators.
Furthermore, the Alfred formula can be used in preparing Alfred formula compacts of other solid materials which can be milled or otherwise provided in a particle size for preparing a solids compact characterized in that it comprises finely-divided solid particles of at least one solid material having a particle size in the range of about 1180 μm to 0.05 μm with at least 5 wgt. % of the particles being of colloidal size, e.g. (-) 3 μm, and having a particle size distribution in accordance with the Alfred consist formula. The solid material can be any natural or synthetic material. Preferably it will be a mineral, or other similar natural material. Most preferably, the solid material will be an ore, for example, iron ore, or a precious metal ore, such as chromium, nickel, silver or gold ore.
The Alfred formula compact of finely-divided solid material having an Alfred formula consist can be mixed with a fluid, which can be water, or a polar solvent, e.g. a ketone or an alcohol, or a hydrocarbon, e.g. fuel oil or naphtha, or a gas, for example, nitrogen, or inert combustion gases, to make a solids-fluid slurry. The amount of fluid used usually will be in an amount at least sufficient to transport the slurry in a pipeline, as is done with the coal-water slurry of the invention.
When the solids-fluid slurry contains water, and the solid material is not water soluble, electrolyte and/or a dispersing agent can be used to disperse the solids in the fluid substantially in the way used to obtain the coal-water slurry having zeta potential at near maximum zeta potential.
It is to be understood that the foregoing description and Examples are illustrative only and that changes can be made in the ingredients and their proportions and in the sequence and combinations of process steps as well as other aspects of the invention discussed without departing from the scope of the invention as defined in the following claims. | A stabilized coal slurry comprising pulverized and purified coal, water and a dispersing agent, said dispersing agent by selective absorption having produced different charging of particles of coal and particles of other substances to obtain purified coal and maintain the stability of the slurry. | 2 |
TECHNICAL FIELD
This invention relates to suppression of electromagnetic interference (EMI).
BACKGROUND OF THE INVENTION
Use of high-bandwidth transmission lines to implement local area networks (LANs) is becoming increasingly common. An example thereof is the Gigabit Ethernet LAN. The high-frequency transmission affected by such transmission lines make suppression of their radiated emissions a significant challenge, on account of the fact that radiated emissions, and the crosstalk to other signal lines caused thereby, increase as transmission frequency increases.
A notch filter is designed to reject a band of frequencies while passing through all other frequencies. Although the use of notch filters to filter out EMI is known (see, e.g., U.S. Pat. No. 6,539,253), a technical challenge in developing a notch filter for EMI suppression is how to effectively deal with parasitic inductance and capacitance, which can deleteriously affect the intended performance of the filter. At ultra-high transmission frequencies, even small parasitic effects can cause significant problems and therefore must be accounted for in the notch filter design.
SUMMARY OF THE INVENTION
This invention is directed to solving these and other problems and disadvantages of the prior art. According to one aspect of the invention, an apparatus comprises a capacitor having a body and a pair of terminals attached to the body, and a conductor defined on the body and connecting the terminals, the conductor having an inductance defining together with a capacitance of the capacitor a parallel LC circuit. The circuit is tuned by varying the width of the traces. The apparatus is illustratively suited for use as a notch filter. According to another aspect of the invention, a notch filter having a notch center frequency comprises a capacitor that has a body and a pair of terminals attached to the body and that has a self-resonant frequency equal to or greater than the notch center frequency, and further comprises a conductive trace that has an inductance and that extends along the body and connects the terminals. Illustratively, when mounted on a printed circuit board (PCB) in a signal line proximate to a ground plane, the notch filter and the ground plane form a virtual conductive loop the product of whose inductance and capacitance is the notch center frequency. According to yet another aspect of the invention, a PCB comprises a signal conductor comprising a pair of discrete conductor segments defined by the PCB, a ground plane defined by the PCB, a capacitor having a body and a pair of terminals on the body that connect the capacitor between the segments, and a conductor defined on the body and connecting the pair of terminals. The conductor has an inductance and forms with the capacitor a notch filter for the signal conductor such that the product of the inductance and the capacitance of a virtual conductive loop formed by the notch filter and the ground plane equals a center frequency of the notch of the notch filter.
Advantages of the invention include a notch filter that is effective at ultra-high frequencies, that is easy to construct, that is tuneable, that minimizes the number of parts used in its construction, that is compact so that it takes up little real estate on a printed circuit board, and that is compatible with surface-mount circuit-assembly techniques.
BRIEF DESCRIPTION OF THE DRAWING
These and other features and advantages of the invention will become more apparent from the following description of an illustrative embodiment of the invention considered together with the drawing in which:
FIG. 1 is a perspective diagram of a printed-circuit-board-mounted notch filter that includes an illustrative embodiment of the invention;
FIG. 2 is a graph of load lines of capacitors illustratively used to implement a 1 GHz notch filter;
FIG. 3 is a graph of load lines of capacitors illustratively used to implement a 4.8 GHz notch filter; and
FIG. 4 is a graph of load lines of capacitors illustratively used to implement a 6.25 GHz notch filter.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows an illustrative embodiment of a notch filter 100 mounted on a printed-circuit board (PCB) 120 . Notch filter 100 spans two segments 124 a and 124 b of a printed-circuit conductor 124 carrying signals that are to be filtered for EMI. Each segment of conductor 124 terminates in a solder pad 126 to which notch filter 100 is electrically connected, e.g., by a component surface-mounting process.
Notch filter 100 consists of a capacitor 102 , preferably a surface-mount capacitor, and a conductive trace 106 of width w and length l defined by (e.g., plated or printed on) and extending the length of body 103 of capacitor 102 . Capacitor 102 is electrically connected to solder pads 126 by conductive terminals 104 that extend from opposite ends of body 103 of capacitor 102 . Trace 106 is electrically connected to terminals 104 , and acts as an inductor there between. Capacitor 102 and trace 106 together form a parallel inductive-capacitive (LC) circuit between the segments of conductor 124 . PCB 120 has a ground plane 122 as one of its layers, which serves as a return path for signals conducted by conductor 124 . Ground plane 122 , capacitor 102 , and trace 106 together form a virtual conductive loop 130 at the resonant frequency of the structure that is formed by them. Loop 130 has a height h l which is the distance between trace 106 and ground plane 122 . h l consists of the height h c of capacitor 102 and depth h g at which ground plane 122 is buried in PCB 120 . A standard thickness of PCB 120 is 62 mils; consequently, h g is normally anywhere between 1 mil and 61 mils. The product of the capacitance (C) and inductance (L) of loop 130 define the center frequency f n of the notch implemented by filter 100 that will be filtered out of the signals on conductor 124 .
As is known, capacitors have an individual self-resonant frequency f c below which they behave capacitively and above which they behave inductively. Typically, the smaller is the capacitance of a capacitor, the smaller is its physical package, and the higher is its self-resonant frequency f c . For ease of design, it is desirable that self-resonant frequency f c of capacitor 102 equal or exceed f n . At this self-resonant frequency f c , the capacitance C of loop 130 is effectively the capacitance of capacitor 102 . Consequently, the required inductance L of loop 130 is L=1/(4π 2 f n 2 C). Inductance L is provided by loop 130 . Inductance L is related to loop height h l as follows:
L = 5 ( 10 - 3 ) ln ( 4 h l d ) l ,
where L is measured in μH, h l is measured in mils, l is the length of trace 106 in inches, and d is the diameter in mils of an equivalent circular cross-section having a circumference πd equal to twice the sum of the width w and thickness t of trace 106 . L is set by selecting the width w of trace 106 . It is assumed that the thickness t of trace 106 is a standard and unvarying approximately 1 mil (.˜7 to ˜1.4 mil) of copper, aluminum, or other conductor; i.e., the standard thickness of a printed circuit trace. Given the dimensions of conventional surface-mountable capacitors, values of L that are reasonably achievable by varying the width w of trace 106 are between about 0.2 nH and about 1.5 nH.
In this illustrative example, it is assumed that conductor 124 suffers from EMI or crosstalk from a Gigabit Ethernet, i.e., f n =1 GHz. Given f n and the reasonably-achievable values of L, an available suitable capacitor 102 is selected. In this example, an illustrative commercially-available capacitor is a surface-mountable 0603-type capacitor (length of 60 mils, width and height of 30 mils) of 27 pF. The selection of capacitor 102 determines height h l of loop 130 (h g being fixed by PCB 120 ) and length l of trace 106 . The inductance L of loop 130 therefore must be set to produce the desired value of f n by selecting the width w of trace 106 .
The proper width w of trace 106 is determined from the following formulas.
L ( h g , w , t , l ) = 5.0 ( 10 - 6 ) · l · ln { 2 ( h l + h g ) π ( w + t ) } ,
where
L=inductance (in μH) of loop 130
h g =vertical distance from bottom surface of capacitor 102 to the return reference plane 122 (in mils)
h l =height of capacitor 102 (in mils)
w=width of trace 106 (in mils)
t=thickness (height) of trace 106 (in mils)
l=length of trace 106 (in mils)
f n ( h g , w , t , l , C ) = 1 2 π L ( h g , y , t , l ) · C , where
where
f n =center frequency of the notch filter, and
C=capacitance (in farads) of loop 130
The Procedure for Determining w, and h g for Fixed t, l, and C Values is as Follows:
(1) Plot f n (h g ,w,t,l,C) for 1≦h g ≦h pcb (total thickness of PCB 120 in mils) and
h l 5 ≤ w ≤ h l
in mils as a surface plot, with h g as the x-axis and w as the y-axis. The vertical z-axis is then the resonant frequency for a given (h g , w) pair.
(2) Superimpose a “reference” surface plot on top of the surface plot generated from step (1) that represents the desired resonant frequency f n . This surface plot will necessarily be a planar surface and should cover the entire (h g , w) range of values as stated in step (1). (3) The intersection of the surface plot from (1) and the planar surface plot from (2) represents the full range of (h g , w) pairs that will produce the desired resonant frequency. This intersecting contour will be a line, referred to as a load line. Implement the solution by fabricating an electroplated copper trace 106 of length l (mils), and width w (mils). (4) If no intersection results from step (3), alter the value of the capacitance C until an intersecting contour is generated from the two surface plots. Make sure to select C such that this capacitor behaves capacitively slightly beyond the desired resonant frequency. In other words, the selected capacitor must have a resonant frequency f c that exceeds the desired resonant frequency f n of the notch filter. (5) If the variable h g is known a-priori, then select the (h g , w) pair that lies on the load line determined from step (3). Implement the solution by fabricating trace 106 of length l, and width w. Usually h g is known a-priori, since the layer stackup of printed circuit board 120 is known before designing the notch filter.
FIG. 2 shows a load line 204 that defines the value of w as a function of h g at f n =1 GHz for a 27 pF 0603-type capacitor. As described above load line 204 is derived by superimposing two surface plots, with their intersection being the load line for a given notch filter center frequency fn._One of the surface plots is a plot of the achievable resonant frequencies as a function of the width w of trace 106 and the depth h g of the reference return path. This surface plot is for a given fixed capacitance of 27 pF in this example. Also, in this example, h l =(30+h g ) mils. Next, a reference plane is superimposed onto the aforementioned first surface plot. This reference plane is the desired notch filter resonant frequency f n of 1 GHz in this example. The intersection of these two surfaces is line 204 that highlights the needed width of trace 106 as a function of the depth h g of ground plane 122 within printed circuit board 120 . The 27 pF 0603-type capacitor is currently believed to be the only capacitor that will provide a 1 GHz notch filter for any depth of ground plane 122 within a conventional 62 mil thick printed circuit board 120 . There are other capacitor values that can provide a 1 GHz notch filter; however, these other values will prevent the depth h g of ground plane 122 from covering the entire 62 mil thickness of PCB 120 . In these cases, the depth h g of ground plane 122 must be greater than some minimal depth, or will only work within some subset of the entire 62 mil PCB thickness. These constraints are restrictive and limit the practicality of using anything but an 0603-type 27 pF capacitor.
Computer simulations indicate that notch filter 100 constructed as described above produces an attenuation better than 7 dB of the 1 GHz EMI.
Instead of using one capacitor 102 and trace 106 to implement notch filter 100 , a plurality of capacitors can be connected in parallel to form capacitor 102 , and one or more of those capacitors can carry traces that together, in parallel, form trace 106 . If capacitors of slightly-different values are used in parallel, the result is a plurality of slightly-different notch filters—or, equivalently, a notch filter having a wider notch—resulting in improved EMI attenuation. One of the advantages of a notch filter 100 constructed in the illustrative manner is that it occupies a very small amount of PCB real estate. To preserve this advantage in the case of a notch filter constructed from a plurality of capacitors, the capacitors may be vertically stacked, illustratively as described in U.S. patent application Ser. No. 10/292,670, filed on Nov. 12, 2002, now abandoned, and assigned to the same assignee as this application. In this illustrative example of a 1 GHz notch filter, a 23 pF 0603-type capacitor may be used in parallel with the 27 pF capacitor. The load line for the parallel combination of the 23 pF and 27 pF capacitors is shown as load line 202 in FIG. 2 .
Of course, the invention may be used to implement notch filters at frequencies other than 1 GHz. Illustratively, FIG. 3 shows a load line 304 for a surface-mountable 0402-type capacitor (length of 40 mils, width and height of 20 mils) of 1.7 pF used to implement a 4.8 GHz notch filter. The dimension h g is the depth at which a ground plane is buried in a PCB, and the dimension w is the width of a trace. Correspondingly to the example FIG. 2 , the 1.7 pF capacitor may advantageously be used in parallel with a 0402-type capacitor of 1.508 pF to implement the 4.8 GHz notch filter. The load line for the parallel combination of the two capacitors is shown as load line 302 in FIG. 3 . Also illustratively, FIG. 4 shows load line 404 for a surface-mountable 0402-type capacitor of 1.023 pF used to implement a 6.1 GHz notch filter. Again, this capacitor may advantageously be used in parallel with an 0402-type capacitor of 0.9 pF to implement the 6.1 GHz notch filter. The load line for the parallel combination of the two capacitors is shown as load line 402 in FIG. 4 . The dimension h g is the depth at which a ground plane is buried in a PCB, and the dimension w is the width of a trace.
Of course, various changes and modifications to the illustrative embodiment described above will be apparent to those skilled in the art. These changes and modifications can be made without departing from the spirit and the scope of the invention and without diminishing its attendant advantages. It is therefore intended that such changes and modifications be covered by the following claims except insofar as limited by the prior art. | An ultra-high-frequency notch filter ( 100 ) comprises a capacitor ( 102 ) defining a conductive trace ( 106 ) on its body ( 103 ) and extending between its terminals ( 104 ). The trace has an inductance that forms a parallel LC circuit with the capacitance of the capacitor. When mounted on a printed circuit board ( 120 ) to connect two segments of a signal line ( 124 ), the notch filter and a ground plane ( 122 ) of the PCB form a virtual conductive loop having an inductance and a capacitance whose product is the center frequency of the notch of the notch filter. The center frequency is tuned by varying the width of the trace. | 8 |
[0001] Priority is claimed to German Patent Application No. DE 103 53 451.2, filed on Nov. 15, 2003, the entire disclosure of which is incorporated by reference herein.
[0002] The present invention relates generally to steam turbines and particularly to a steam turbine with a rotor rotatable about an axis and surrounded concentrically by a casing.
BACKGROUND
[0003] Steam turbines of the modern type of construction for high efficiencies and high steam inlet temperatures comprise a rotor which is rotatable about an axis of rotation and which is surrounded by a casing. The casing is subdivided into an inner casing, which surrounds the rotor concentrically, and an outer casing, which surrounds the inner casing together with the rotor. Between the rotor and the inner casing is formed a steam duct which is in the form of an annular gap and through which the steam is conducted for the performance of work. The blading of the steam turbine is arranged in the steam duct and consists of alternately arranged rings of stationary guide vanes and of moving blades fastened on the rotor. The guide vanes are arranged on the inner wall of the inner casing, said inner wall delimiting the steam duct (see, for example, EP-A1-0 952 311 or U.S. Pat. No. 5,695,317 or U.S. Pat. No. B1-6,315,520).
[0004] Both the outer casing and the inner casing are conventionally horizontally divided thick-walled castings composed of a comparatively costly high-temperature alloy. For example, a steel casting is used for the outer casing. The inner casing, exposed to especially high pressures and temperatures, mostly consists of a special nickel-based alloy. Steam turbines with steam inlet temperatures of about 700° C. or above are currently in the planning stage. Pressures of several 100 bar, for example 350 bar, occur in this case.
[0005] According to current estimates, the starting time of steam turbines of the type described amounts to several hours, since, because of the large dimensions and wall thicknesses, the rotors and the casing require a long time before they can be heated to the operating temperature, without excessively high thermal stresses being generated. Further disadvantages of a high-mass inner casing are the high costs, since the nickel-based alloy is a very costly material. Also, for such large castings, there are long delivery times of several months. Since the inner casings are divided and the parts are screwed to one another via flanged connections, high-mass parting line flanges are present which make up a considerable proportion of the entire casing weight. Large and costly parting line screws for the flanged screw connection also have to be employed correspondingly.
SUMMARY OF THE INVENTION
[0006] An object of the present invention is to provide a steam turbine that avoids the described disadvantages of known steam turbines and is distinguished, particularly by virtue of a novel casing design, by a reduced starting time during operation and by more cost-effective and quicker production. A further or alternate object of the present invention is to specify a method for the production of such a steam turbine.
[0007] The present invention provides a steam turbine ( 10 , 40 , 50 ) with a rotor ( 18 ) rotatable about an axis ( 47 ) and surrounded concentrically by a casing ( 11 ), characterized in that the casing ( 11 ) comprises a high-mass hollow-cylindrical basic carrier ( 21 ) and a plurality of shells ( 21 , 12 , 22 , 13 , 23 , . . . , 17 , 27 ) which surround the basic carrier ( 21 ) concentrically and are produced from a bent metal sheet and between which interspaces ( 48 ) capable of being filled with steam are provided.
[0008] The casing is constructed from a high-mass hollow-cylindrical basic carrier and a plurality of shells which surround the basic carrier concentrically and are produced from a bent metal sheet, interspaces capable of being filled with steam being provided between these shells. Instead of a high-mass cast inner casing which absorbs both the internal pressure and the shearing force, therefore, sheets, preferably in standard dimensions, are used in a plurality of layers. These absorb essentially only the internal pressure. The guide vanes are mounted in the basic carrier when the casing is an inner casing. Said basic carrier absorbs essentially only the shearing force and the load moment and transmits the shearing force to the axial guide and the load moment to the supports. The casing is mounted and guided via the basic carrier. The basic carrier is subjected to little internal pressure stress and can therefore be constructed with a small wall thickness.
[0009] A preferred embodiment of the present invention is distinguished in that the basic carrier is composed of a plurality of annular carrier segments arranged one behind the other in the axial direction and connected to one another, in that the shells have a barrel-shaped design, the next outer shell in each case surrounding all the further inward-lying shells both in the radial and in the axial direction, and in that the shells are connected on the end faces in each case to one of the carrier segments of the basic carrier in a steamtight manner. By the basic carrier being divided axially into segments connected to one another, the production of the casing is simplified considerably.
[0010] Good accessibility for assembly and maintenance is achieved in that the basic carrier and the shells are subdivided in a horizontal midplane into an upper and a lower part or into upper and lower segment halves and into upper and lower shells which are in each case screwed to one another in pairs via flanged screw connections. Preferably, to form the flanged screw connections, in each case horizontal flanges are attached, in particular welded, to the upper and lower shells.
[0011] Assembly may be further simplified in that the upper shells are in each case screwed to the upper segment halves, preferably via a semiannular flanged connection, and in that the lower shells are in each case welded to the lower segment halves.
[0012] So that the pressure drop from the inside outward can be apportioned correctly to the individual shells, it is advantageous that the carrier segments of the basic carrier are connected to one another in such a way that steam can flow out of the interior of the basic carrier into the interspaces between the shells.
[0013] Another embodiment of the present invention is characterized in that the steam for operating the steam turbine is conducted to the rotor from outside through all the shells of the casing by means of at least one inlet pipe, and in that the at least one inlet pipe, in its passage through a shell, is in each case sealed off by means of a piston ring seal.
[0014] In particular, the casing may be an inner casing or a combined inner and outer casing, there being formed, between the basic carrier and the rotor, a steam duct, in which is arranged a blading comprising guide vanes and moving blades, and the guide vanes of the blading being fastened to the inner wall of the basic carrier. The casing may in this case be of single-flow or double-flow design.
[0015] The casing may, however, also be an outer casing. The basic carrier then carries no blading on the inside, but seals instead.
[0016] Preferably, the shells are produced in each case from a standard metal sheet consisting of a high-temperature nickel-based alloy, in particular of Alloy 617, with a sheet thickness, dependent on the position of the shell in the casing, of several millimeters, in particular of between 3 and 11 millimeters.
[0017] A less costly material, preferably rolled sheet steel, may also be used in the outer shells, in which the steam temperature is markedly lower than in the inner shell.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The present invention will be explained in more detail below by means of exemplary embodiments, with reference to the drawings in which:
[0019] FIG. 1 shows a cross section through the set-up of a multishell inner casing of a steam turbine according to a first preferred exemplary embodiment of the present invention;
[0020] FIG. 2 shows, in the form of an enlarged detail, the flanged connection of an upper and a lower shell of the exemplary inner casing from FIG. 1 ;
[0021] FIG. 3 shows a longitudinal section through a double-flow inner casing of the type illustrated in FIG. 1 , with the central inlet pipes for the steam inlet;
[0022] FIG. 4 shows an illustration, comparable to FIG. 3 , of a single-flow inner casing of the type illustrated in FIG. 1 ;
[0023] FIG. 5 shows, in two views from the side and in the axial direction (part FIGS. 5A and B), two upper segment halves of a basic carrier according to the present invention which are welded to one another via short round bars; and
[0024] FIG. 6 shows, in an illustration comparable to FIG. 5 , the upper half, cast or forged in one piece, of a basic carrier according to the present invention, in which the radial passage of steam between the segments is ensured by means of bores.
DETAILED DESCRIPTION
[0025] The present invention is based on arranging a large number of bent sheets one behind the other instead of a high-mass cast casing or inner casing. Since the sheets are comparatively thin and are effectively insulated from one another thermally by means of the gap lying between them, the thermal stresses are low. The casing is therefore suitable for starting in a very short time. Further advantages are:
[0026] The delivery time is markedly shorter than where cast casings are concerned, since the sheets are commercially available. With standard dimensions, the sheets are already available in commercial depots. Alternatively, a specific depot may be set up.
[0027] A smaller quantity of costly nickel-based material is required, specifically for three reasons:
[0028] On account of the insulation of the sheets from one another, the temperature decreases sharply from the inner shell to the outer shell. A more cost-effective material can therefore be used in the colder outer shells.
[0029] Owing to the sharper temperature drop from the inner shell to the outer shell, as compared with the conventional cast casing, the temperatures in the outer shells are lower. Accordingly, the material strength, which increases with a decrease in temperature, is higher there, so that a smaller wall thickness of the shell is sufficient.
[0030] The high-mass parting line flange of a conventional cast casing forms a considerable proportion of the entire casing weight. In the casings according to the present invention, because of the low pressure difference from shell to shell, only very small flanges, which are very light as compared with the casing shell, are required.
[0031] The parting line screws of the flanged screw connections in the case of the shells divided in a horizontal midplane can have a very small design, as compared with conventional parting line screws. As a result, on the one hand, they can be delivered more quickly, since commercially available thin raw material can be used for manufacture. On the other hand, they can be produced more cost-effectively, since the commercially available raw material is more cost-effective and since they can be manufactured on smaller machines.
[0032] Instead of a high-mass cast inner casing which absorbs both the internal pressure and the shearing force, sheets in standard dimensions are used in a plurality of shells. These absorb essentially only the internal pressure. The guide vanes are mounted in the basic carrier. The latter absorbs essentially only the shearing force and the load moment and transmits the shearing force to the axial guide and the load moment to the supports. The casing is mounted and guided via the basic carrier. The basic carrier is subjected to almost no internal pressure stress and can therefore be constructed with a small wall thickness.
[0033] FIG. 1 shows the basic principle in a cross-sectional illustration by means of an exemplary embodiment: the inner casing 11 of a steam turbine 10 , said inner casing surrounding a rotor 18 concentrically, is illustrated. Between the rotor 18 and the inner casing 11 , a steam duct 20 in the form of an annular gap is left free, in which is arranged a blading 19 comprising guide vanes and moving blades.
[0034] Metal sheets bent into a barrel shape and having a thickness of a few millimeters, preferably of between 2 and 11 millimeters, which consist of the here six upper shells (upper halves) 12 , 13 , 14 , 15 , 16 and 17 and of the six lower shells (lower halves) 22 , 23 , 24 , 25 , 26 and 27 , are laid in the manner of onion skins around the steam duct 20 and the rotor 18 . The upper and lower shells are fixed to one another in each case via a welded-on small horizontal flange 28 , 29 (see also FIG. 2 ) and a flanged screw connection 30 . The guide vanes in the steam duct 20 are mounted on a basic carrier 21 which likewise consists of an upper part 21 a and of a lower part 21 b which are both fixed to one another by means of a small flange (horizontal flange halves 52 , 53 in FIGS. 5 and 6 ) and a flanged screw connection 30 . Between the upper and lower shells 12 , . . . , 17 and 22 , . . . , 27 , interspaces 48 are left free which are filled with steam via orifices in the basic carrier 21 during operation. The steam pressure decreases from the inside outward from interspace to interspace of the upper and lower shells 12 , . . . , 17 and 22 , . . . , 27 .
[0035] FIG. 2 shows, in the form of an enlarged detail, an exemplary horizontal flanged connection of the upper and lower shells from FIG. 1 (flanged screw connection 30 in FIG. 1 ). In FIG. 2 , an upper shell 17 is welded to a flange upper part 28 . The lower shell 27 is welded to the flange lower part 29 . The associated weld seams are given the reference symbol 36 . A screw bolt 32 is inserted through in bores 35 in the flange upper part 28 and lower part 29 , said screw being braced by means of nuts 33 and 34 and sealing off the parting line 31 between the flange upper part 28 and the flange lower part 29 .
[0036] FIG. 3 shows a longitudinal section through a double-flow inner casing 11 of a steam turbine 40 . The inner casing 11 again comprises a basic carrier 21 with an upper part 21 a and lower part 21 b and also upper shells 12 , . . . , 17 and lower shells 22 , . . . , 27 . The rotor 18 rotates about the axis 47 . A flow 44 and 45 together with the corresponding blading 19 is arranged on each of the two sides of central inlet pipes 37 , 38 . The steam flows through the inlet pipes 37 (top) and 38 (bottom) to the rotor 18 and is then apportioned to a left flow 44 with the blading 19 and to a right flow 45 with the blading 19 . The inlet pipes 37 and 38 are led via piston ring seals 39 (top) and 41 (bottom) through the upper shells 12 , 13 , 14 , 15 , 16 , 17 and the lower shells 22 , 23 , 24 , 25 , 26 , 27 and the innermost ring (carrier segment 46 ′) of the basic carrier 21 .
[0037] The basic carrier 21 , on the one hand, is divided horizontally into an upper part 21 a and a lower part 21 b and, on the other hand, is subdivided axially into carrier segments 46 (more precisely, segment halves 46 a, b ) which carry the guide vanes of the blading 19 on the insides and to which the upper and lower shells 12 , . . . , 17 and 22 , . . . , 27 are fastened. In the example of FIG. 3 , six carrier segments 46 (12 segment halves 46 a,b ) are provided on each of the two sides of the innermost carrier segment 46 ′ through which the inlet pipes 37 , 38 are led. The individual carrier segments 46 are connected to one another in such a way that steam can flow out of the steam duct into the interspaces 48 of the upper and lower shells. For mounting the upper shells 12 , 13 , 14 , 15 , 16 , 17 , it is necessary to screw these to the upper segment halves 46 a of the basic carrier 21 by means of a semiannular flanged connection 42 . The lower shells 22 , 23 , 24 , 25 , 26 , 27 can be connected to the lower segment halves 46 b by means of weld seams 43 .
[0038] In FIG. 3 , the connection of the upper and lower shells 12 , 13 , 14 , 15 , 16 , 17 and 22 , 23 , 24 , 25 , 26 , 27 to the basic carrier 21 takes place axially, in each case approximately at the segment center. If, however, this screw or welded connection is formed at that end of the carrier segment 46 which is directed downstream with respect to the steam flow, the carrier segment 46 of the basic carrier 21 is acted upon by an external pressure. The horizontal flange screws which hold together the upper and lower part 21 a, b of the basic carrier 21 may then have a very small design or they may even be dispensed with completely.
[0039] FIG. 4 shows a longitudinal section through a single-flow inner casing 11 of a steam turbine 50 . The steam flows through the inlet pipes 37 (top) and 38 (bottom) to the rotor 18 and then to the left through the blading 19 . A residual steam flows through the casing seal 49 (here, labyrinth seal) arranged on the right side. The inlet pipes 37 and 38 are led via piston ring seals 39 (top) and 41 (bottom) through the upper shells 12 , 13 , 14 , 15 , 16 , 17 and the lower shells 22 , 23 , 24 , 25 , 26 , 27 and the inner carrier segment 46 ′ of the basic carrier 21 . The inner carrier segment 46 ′ carries the first guide vanes of the blading 19 on the left side and the casing seals 49 on the right side. The carrier segments 46 on the right of this inner carrier segment 46 ′ carry the further casing seals, and the carrier segments 46 on the left of this inner carrier segment 46 ′ carry the further guide vanes. Between the carrier segments 46 , 46 ′ are orifices which allow the steam to flow into the interspaces 48 of the upper and lower shells. Between the carrier segments 46 , 46 ′ which carry the casing seals, these orifices may be dispensed with. This rules out the situation where hot steam flows out of the seals into the interspaces 48 of the upper and lower shells. The seals should, however, be designed in such a way that the pressure difference between the interspaces 48 and the seals 49 is low. Preferably, the pressure in the interspaces should be slightly higher, so that, in the event of a leak, colder steam flows out of the interspace into the seal, not vice versa.
[0040] For mounting the upper shells 12 , 13 , 14 , 15 , 16 , 17 , it is necessary to screw these to the upper segment halves 46 a of the basic carrier 21 by means of a semiannular flanged connection 42 . Should the turbine not have to be dismantled again, the upper shells 12 , 13 , 14 , 15 , 16 , 17 may also be connected to the upper segment halves 46 a of the basic carrier 21 by means of a welded connection.
[0041] The lower shells 22 , 23 , 24 , 25 , 26 , 27 may again be connected to the lower segment halves 46 b by means of weld seams 42 .
[0042] FIG. 5 shows two upper segment halves 46 a of a basic carrier 21 . In the example illustrated, the segment halves 46 a are connected to short round bars 51 , for example by welding. The segment halves 46 a themselves may consist, for example, of bent sheet metal or of forged half rings. The round bars 51 for the adjacent segment halves not yet welded on are also illustrated. The voids between the round bars 51 allow the steam to flow into the interspaces 48 of the upper and lower shells (see FIGS. 3 and 4 ). Round flanges 54 with bores 55 distributed over the circumference are attached to the segment halves 46 a , the upper shells ( 12 , . . . , 17 in FIG. 1 to 4 ) being screwed to said round flanges. Furthermore, horizontal flange halves 52 and 53 are attached, by means of which the upper segment halves 46 a illustrated can be screwed to the associated lower segment halves (not illustrated).
[0043] FIG. 6 shows the upper half or the upper part 21 a of a basic carrier 21 . In contrast to FIG. 5 , the segment halves 46 a are connected in that the entire upper part 21 a of the basic carrier 21 is cast or forged in one piece. The permeability of the steam into the interspaces 48 of the upper and lower shells (see FIGS. 3 and 4 ) is ensured by means of bores 56 . The round flanges 54 having the bores 55 are attached to the segment halves 46 a , the upper shells being screwed to said round flanges. Furthermore, horizontal flange halves 52 and 53 are again provided, by means of which the illustrated upper part 21 a of the basic carrier 21 can be screwed to the lower part 21 b (not illustrated).
[0044] The claws and webs for the supports and guides of the casings 11 are not shown in the figures. Claws and webs are attached, for example, to the outermost carrier segments 46 of the basic carrier 21 .
[0045] In the figures, the casing 11 is designed as an inner casing. However, an outer casing, too, may be produced in the multishell design according to the present invention with a stepped pressure reduction. Instead of the basic carrier segments with blading (left side in FIG. 4 ), basic carrier segments with casing seals 49 (right side in FIG. 4 ) are used on both sides.
[0046] The inner and outer casings configured according to the present invention may also be combined. For example, in FIG. 4 , one or more shells are added on the outside, in which only seals are attached to the associated additional carrier segments of the basic carrier. Then, in a similar way to the inlet pipes 37 and 38 , an outlet pipe with piston seals is led through these added shells, the steam being capable of flowing outward through said outlet pipe.
[0047] The bent shells (upper and lower shells) can be produced in a simple and cost-effective way by means of the method of end-controlled bending, as disclosed in German patent specification DE-C2-43 10 773.
[0048] For an exemplary 400-MW steam turbine with an HP and MP part, it is necessary in the HP part to have 5 shells consisting of Alloy 617 which have stepped wall thicknesses of 9 to 10.5 mm. The MP part has 3 shells consisting of Alloy 617 with stepped wall thicknesses of 3.8 to 5.8 mm. In each case 3 stages of the turbine (3 guide vane rings and 3 moving blade rings) are assigned to a carrier segment of the basic carrier.
[0049] Overall, the present invention affords the following advantages:
Starting of a 700° C./720° C. turbine possible within a few minutes (instead of 5 hours at the present time). Reduced delivery time for the casing. Cost saving with regard to the casing and to the casing screws. Casings: standard metal sheets, if appropriate standardized, are used instead of cast iron (conventional design). The standardization results in a cost benefit. There is additionally also a cost benefit because less nickel-based material is required, since a change to the material of the next lower quality is possible directly in the next “onion skin”. Parting line screws: small screws are mass products or in any event can be manufactured everywhere and are therefore inexpensive. As a result of standardization, the sheets and the individual segments of the basic carrier can be kept in stock. Standard sheets may also alternatively be procured from the sheet manufacturer's depot. The delivery time is thereby drastically reduced, since there is no dependence on the long delivery time of a casting foundry. | A steam turbine including a rotor rotatable about an axis and a casing concentrically surrounding the rotor. A reduction in the starting times and reduced production costs may be achieved in that the casing includes a high-mass hollow-cylindrical basic carrier and a plurality of shells concentrically surrounding the basic carrier. The shells are each produced from a bent metal sheet and interspaces capable of being filled with steam are defined between adjacent ones of the plurality of shells. | 5 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. application Ser. No. 11/823,862, now issued as U.S. Pat. No. 7,983,738, which claims priority on U.S. Provisional Patent Application Ser. No. 60/817,623 filed on Jun. 29, 2006, the disclosures of which are incorporated herein by reference. This application is also a continuation in part of U.S. application Ser. No. 11/478,322, also filed on Jun. 29, 2006, which claims priority on U.S. Provisional Patent Application Ser. No. 60/757,704, entitled “Micro Vein Enhancer,” filed on Jan. 10, 2006, which are also incorporated by reference herein
SUMMARY OF THE INVENTION
A laser based imaging system that can image veins, arteries, or other organs containing blood, and can generate three dimensional images representative thereof.
BACKGROUND OF THE INVENTION
It is known in the art to use an apparatus to enhance the visual appearance of the veins and arteries in a patient to facilitate insertion of needles into those veins and arteries as well as other medical practices that require the identification of vein and artery locations. Such a system is described in U.S. Pat. Nos. 5,969,754 and 6,556,858 incorporated herein by reference as well as publication entitled “The Clinical Evaluation of Vein Contrast Enhancement”. Luminetx is currently marketing such a device under the name “Veinviewer Imaging System” and information related thereto is available on their website, which is incorporated herein by reference.
The Luminetx Vein Contrast Enhancer (hereinafter referred to as LVCE) utilizes a light source for flooding the region to be enhanced with near infrared light generated by an array of LEDs. A CCD imager is then used to capture an image of the infrared light reflected off the patient. The resulting captured image is then projected by a visible light projector onto the patient in a position closely aligned with the image capture system. The light source for flooding the region to be enhanced does not deeply penetrate into the patient, and therefore, only the veins on the surface of the patient are imaged. Further, the image representative of the veins which is rendered onto the patient is two dimensional and does not provide any depth information. Still further, there is no method using such technology to display blood flowing at a given depth in the patient.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a perspective view of the optical apparatus for the laser based vein enhancer of the present invention.
FIG. 2 is a control block diagram of the controlling elements of the optical apparatus of FIG. 1 .
FIG. 3A is a side cutaway view of a patient's arm. illustrating. the veins within the patient's arm.
FIG. 3B is a top view of the veins in the arm of the patient in FIG. 3A .
FIG. 3C is a side view of the veins in the arm of the patient in FIG. 3A .
FIG. 4A is a side view of the veins in the arm of the patient in FIG. 3A , showing the scan depth lines from N=1 through N=17.
FIG. 4B shows 17 images for N=1 through N=17 of the arm of the patient in FIG. 3A that are stored in the image memory of laser based vein enhancer of the present invention.
FIG. 5 is a flow chart illustrating an embodiment of the image formatter of the optical apparatus of FIG. 2 .
FIG. 6 is a top view of the veins in the arm of the patient in FIG. 3A . utilizing different patterns to differentiate between the various different veins and arteries. FIG. 7 is a flow chart of another embodiment of the image formatter of the optical apparatus of FIG. 2 .
FIG. 8 is a flow chart of a third embodiment of the image formatter of the optical apparatus of FIG. 2 .
FIG. 9 shows a top front perspective view of an embodiment of the image formatter of the optical apparatus of FIG. 2 .
FIG. 10 shows the projection plane of the laser based vein enhancer of the present invention on a cross section of a patient's arm.
FIG. 11 is an illustration of how an embodiment of the laser based vein enhancer of the present invention accurately projects the correct vein size regardless of the depth of the veins within the patient's arm.
DETAILED DESCRIPTION OF THE INVENTION
Preliminary application 60/757,704, incorporated herein by reference, described a miniature laser based system for imaging a patient's veins and arteries and then rendering them onto the surface of the patient's skin. Tests of such a system has shown that the laser based imaging system can penetrate and image very deeply into the patients body, and in some cases, such as the hand or arm, can image entirely through the hand or arm. Further, it has been found that the depth of penetration of the imaging is a function of the amount of laser power applied. Using these principals, a three dimensional imaging system is now described.
FIG. 1 . shows the optical apparatus for a laser based vein enhancer. A single colored laser 180 , for example a 630 nm semiconductor red laser, is projected into combiner 181 . A semiconductor laser 183 is also projected into the combiner 181 . Laser 183 may have a wavelength from 700 nm to 1000 nm, with a preferred wavelength of 740 nm.
An illustrative example of a semiconductor 740 nm laser is Sacher Lasertechnik's Fabry Perot Diode Laser 740 nm, 10 mw, model number FP-0740-10. The combiner 181 outputs a combined laser beam 184 which is the combination of the 630 nm red and the 740 nm laser beams. Combiners for combining two lasers of different frequencies are well known in the art and will not be further described herein. The combined laser beam 184 is positioned to hit off mirror 172 and then to hit the MEMS scanner 173 . The MEMS scanner moves in a raster pattern thereby causing the combined laser beam to move along optical path 5 forming a raster pattern at the field of view 4 . A photodetector 182 which is responsive to the 740 nm wavelength is provided and receives 740 nm light reflected off objects in the field of view. The photodetector 182 outputs an analog signal representing the amount of 740 nm light received. An illustrative example of a photodetector is Roithner Lasertechnik's model number EPD-740-1.
FIG. 2 shows a control block diagram for controlling the elements in FIG. 1 to form a three dimensional imaging system. An electronic block 192 for driving the MEMS driver and for sensing the position of the raster scanner is provided. This block 192 generates the signals required to drive the MEMS scanner 173 in a raster pattern, and also determines the exact instantaneous location of the MEMS scanner and communicates this information to an image memory array 191 A- 191 N. This electronic block 192 also generates output signals indicating the frame count and communicates such signals to image memory array 191 A- 191 N, image formatter 300 , image memory two 196 , and laser intensity block 301 .
Assuming the frame rate is sixty frames per second, the frame count will cycle from one through sixty. The operation is as follows. The MEMS scanner 173 is driven in a raster pattern. The first full frame after achieving a stable raster pattern will be identified as frame one by the frame counter. Thereafter each subsequent frame will increase the frame counter by one, up to sixty, and thereafter the frame counter will reset to one and then start the cycle again. Laser intensity block 301 drives the laser drivers 195 at a select one of sixty levels depending upon the current frame counter level. More particularly, the laser intensity block 301 drives the laser drivers 195 in such a manner that the power output from the 740 nm laser 183 linearly increases in sixty steps as the frame counter increments from one to sixty. During the first sixty frames of operation the laser drive 194 for the 630 nm laser 180 is turned off. The light from the 740 nm 183 is reflected off the patient and absorbed by the blood in the veins in a patient's body and the reflected light is sensed and converted into an analog signal by 740 nm photo detector 182 . The analog signal is then passed through an A/C converter 190 which outputs a digital representation to image memory 191 A- 191 N, wherein in this example A=1 and N=60. Image memory 191 A- 191 N receives instantaneous position information from the electronic block 192 , and based upon such information, the digital representation for each pixel is stored in a memory location corresponding to a particular pixel. This is repeated for each pixel within a frame. In this manner, each frame is stored in an associated image memory. Upon completion of the first sixty frames, the image memory 191 A- 191 N contains sixty images of the veins within the field of view of the 740 nm laser 183 , wherein each sequential image memory contains an image which has been obtained with increased laser intensity. After the completion of the sixtieth frame, the image memory is forwarded to an image formatter 300 , which in turn forms an image which is transferred to image memory two 196 . During each of the next sixty frames of the cycle, the data in the image memory two 196 is read out as a function of the instantaneous position information provided by the electronic block 192 and provided to a D/A converter 193 which outputs an analog signal to laser drive 194 which drives the 630 nm laser 180 . In this manner, the image that was stored in image memory two 196 is projected by the 630 nm laser 180 onto the patient. In this manner, the veins that are in the field of view become visible to the practitioner.
While in the above embodiment, the frame count (number of slices of images taken) was sixty, the frame count could be more or less than sixty. Also, the laser intensity 301 was indicated to go up linearly. It is also possible to have a look-up table or algorithm which provides for non-linear step-ups in power. To simplify the discussion, the power changes have been described in a “step-up” fashion. The order in which the various steps are taken are unimportant, it is the capture of the vein signal at various intensities is what is important to the process.
The operation of image formatter 300 will now be described in greater detail. To simplify the Figs. shown, a maximum frame count of 17 (N=17) is illustrated as opposed to the frame rate of 60 (N=60) previously described. Accordingly, for the purpose of the illustrations the laser will cycle through 17 frames at 17 different increasing power levels. Referring to FIG. 3A , a three dimension illustration of a patient's arm 309 is shown. The arm has a top vein 310 which is closest to the top surface and bottom vein 312 which is the deepest as viewed from the top surface and middle vein 311 which is between the two. FIG. 3B shows a top view 308 of the veins 310 , 311 and 312 as viewed from the top of the arm if the arm was transparent and the veins were not. FIG. 3C shows a side view 307 of the veins 310 , 311 and 312 as viewed from the side of the arm (assuming again for the moment the arm is transparent and the veins are not).
The laser based vein enhancer of FIG. 1 and FIG. 2 is positioned so that the field of view corresponds with the top view 308 of the patient's arm 309 shown in FIG. 3 . FIG. 4A again shows the side view 307 but also includes along the right edge scan depth lines 314 N=1 through N=17. These scan depth lines 314 indicate how deeply the laser light penetrates into the arm at each respective laser intensity level N=1 through N=17. FIG. 4B shows 17 images N=1 through N=17 that are stored in image memory 191 A- 191 N. Referring to the image memory associated with frame one (N=1), the intensity of the laser only penetrates the patient arm to the depth shown by the N=1 scan depth line 314 .
Since this depth does not reach vein 310 , 311 or 312 as shown in FIG. 4A , the image stored for the first frame N=1 is blank. The same applies to the second frame N=2. The third frame N=3 reaches partly into vein 310 and accordingly the image stored in image memory associated with the third frame (where N=3) begins to faintly show vein 310 . Frames 4 , 5 and 6 each penetrate successively deeper into vein 310 and therefore the image of vein 310 gets successively darker in the image memory 191 A- 191 N associated with frames 4 , 5 and 6 (N=3, 4 and 5). Similarly, starting with frame 7 (N=7), the middle vein 311 begins to appear and then starting with frame 11 (N=11) the deepest vein 312 begins to appear. By frame 14 the laser light penetrates all the way through veins 310 , 311 , and 312 and therefore the images for frames 14 through frame 17 are approximately the same and show all the veins.
If the image for frame 17 (N=17) were to be projected onto the patients arm, there would be no way for the practitioner to determine the relative depths of veins 310 , 311 or 312 . Accordingly the image needs to be reformatted so as to provide additional information to the practitioner before projecting on the patients arm.
Referring to FIG. 5 , an illustrative embodiment of the image formatter 300 of FIG. 2 is flow-charted. The frame counter N is set at 0 in step 2 and all previously stored vein/artery images are cleared. In step 3 the counter N is increased by one. In step 4 the frame counter is tested to see if all 17 frames are completed. Accordingly, step 5 will be reached for each of the 17 successive images (N=1 through N=17). In step 5 the image N is recalled from the appropriate image memory 191 A- 191 N. In step 6 all previously stored vein/artery pattern are subtracted. During the first frame N=1 there will be no previously stored vein/artery pattern to be subtracted since they were cleared at step 2 . At step 7 , image processing is performed to detect whether a vein or artery pattern is found. Since it is know that veins and arteries are tube shaped and have a length much greater than their diameter, relative straightforward computer processing can be used to identify such a pattern. If a new pattern is detected at step 8 the new vein/artery pattern is stored at step 9 and the program returns to step 3 . If there is no new pattern detected in step 8 the program returns to step 3 .
Now applying step 1 through step 8 to the images shown in FIG. 4B , assuming that image N=3 represents the first time step 7 detects a vein 310 , the image of the vein 310 is stored at step 8 . Thereafter, in each subsequent image processed, the image of vein 310 is removed from the image at step 6 . Then assuming when the N=7 the second vein 311 is detected in step 9 , the image of vein 311 is stored and accordingly removed the next time the program reaches step 6 . Finally when the N=11 the deepest vein 312 is detected in step 9 , the image of vein 312 is stored and accordingly removed the next time the program reaches step 6 . After completing the last frame 17 , the program moves to Step 9 wherein each stored vein/artery pattern is replaced with a unique pattern. For example, the pattern of vein 310 can be replaced with a diagonally striped pattern, the pattern of vein 311 can be replaced by a checked pattern, and the pattern of vein 312 can be replaced with a light grey pattern. At step 10 each of the now unique patterns for each of the stored vein/artery patterns are layered on top of each other, with the first found pattern falling on the top, the second pattern in the middle and the third pattern on the bottom. In step 11 , the image of step 10 is transferred to image memory two 196 (See FIG. 2 ). The image of step 10 is then projected by the visible laser onto the patients arm.
FIG. 6 shows the resulting image 320 projected onto the patients arm. As can be seen, vein 310 is represented by the diagonally striped pattern, vein 311 represented by the checked pattern, and vein 312 by a light grey pattern. It is clear to the practitioner that vein 310 is positioned above veins 311 and 312 since the diagonally striped pattern at the intersection points of the respective veins. Similarly it is clear that vein 311 is positioned above vein 312 since the checked pattern appears at the intersection point of veins 311 and 312 .
In FIG. 6 , diagonal striped patterns, checked pattern, and a light grey pattern were utilized for differentiating between the various different veins/arteries, however, the invention is not limited thereto. Varying patterns, such as dotted lines having different dot-space characteristics could have been utilized to represent veins at different depths. Alternatively, solid images having different intensities could have been utilized, wherein, for example, those veins closer to the surface are represented by dark projections and deeper veins by lighter projections. Still further, the red laser 180 could be replaced by multiple color lasers, for example red, green and blue, all arranged so that their projections are aligned coaxially. By mixing the amount of each laser, color images can be projected. Accordingly, each different depth vein can be represented by a different color.
A further embodiment is shown with reference to FIG. 7 . In this embodiment, the capturing of the vein/artery image is the same as shown previously with reference to FIG. 2 and the resulting image gets stored in image memory 191 A- 191 N. However, in this embodiment, the image is not transmitted back onto the patient, but instead is transfer to a computer 325 and is then displayed on a three dimension (3D) display 326 . More specifically, three dimensional computer software is known in the art, such a CAD (computer aid design) software or medical imaging software, for manipulating and outputting 3D images. One example of such CAD software is SolidWorks. An example of medical imaging software is an Advanced 3D Visualization and Volume Modeling software from Amira. See Real Technologies provides a stereo 3D display (Model C-s Display) which receives image information over a DVI connection from a graphics card of a Windows based computer and allows the user to view such 3D image without necessitating special glasses. Such Windows based computer must be fitted with a special graphics card, such as NVidea Open GL Video card, to enable the driving of the display.
Utilizing the computer 325 and 3D display 326 , the practitioner can view the veins in 3 dimensions. The 3 dimensional images can be rotated by the CAD software, and cross-section slices of the 3 dimensional images can be performed. Still further, it is possible to utilize a 2 dimensional display with CAD software converting the 3D image into meaningful 2D displays.
FIG. 8 shows a still further embodiment wherein the visible laser projection onto the patient of FIG. 2 is combined with the 3D display 326 described with reference to FIG. 7 . In this case, the image is projected onto the patient by the 630 nm laser 180 while concurrently being displayed in 3D on screen 326 . In this manner the practitioner can find the exact positioning of the veins as projected on the patient and can also view a 3D representation of the veins/arteries under the surface.
FIG. 9 shows an embodiment similar to that shown in FIG. 15A of preliminary application No. 60/757,704.
In this embodiment the Miniature Vein Enhancer (MVE) 150 includes a small display 325 ; having attached thereto an attachment piece 154 and a Miniature Projection Head (MPH) 2 . Although the attachment is shown at a right angle to the stem extending vertically from the vial, the stem can be at an angle to the vial and the display angle can vary, as well. A needle protector 156 , connects to a vial holder 7 . The attachment piece 154 receives the top of the needle protector and temporarily locks the MVE to the needle protector 156 which in turn attaches to the vial holder 7 . The MPH 2 is attached to the small display 151 and is oriented so that the optical path 5 is such that the field of view 4 covers the point of the needle 14 . The MPH 2 outputs the image of the veins 11 onto the field of view 4 on the patient (not shown). The MPH 2 also provides the image signal to the display 151 to be viewed on the display 151 . The image signal includes both the veins and the needle 14 . The display 151 includes image processing capabilities that detects the position of the tip of the needle and displays a predetermined number of pixels of the image around the tip of the needle on the display. In FIG. 14C , both the image of the needle 153 and the image of the vein 152 are shown.
The unit of FIG. 9 is driven by the electronics (not shown) describe previously in FIG. 8 , wherein the computer 325 , including the graphics card logic and 3D software, are miniaturized and housed in the MVE 150 and wherein the display is a small 3D display 326 attached to the MVE 150 . Accordingly, when this device is used, the practioner can view the projected image on patient, as well as the three dimensional image on the 3D display 326 .
With reference to FIG. 10 , a correction methodology is now described. The projection/imaging optical cone 445 of the MVE unit originates at the mirror of the MVE and diverges from there. The projection angle, for example, could be 60 degrees. A cross section of a patient's arm 446 is shown with a cross section of a first vein 443 shown at a first imaging plane 441 and a cross section of a second vein 444 shown at a second imaging plane 441 . A projection plane 440 is also shown, which is approximately on the top surface of the arm 446 of the patient and represents where the image is displayed on the patient. In this example, the first imaging plane 441 is half way between the projection plane 440 and the second imaging plane 442 . Due to the projection angle, the second imaging plane 442 is wider than the first imaging plane 441 which in turn is wider than the projection plane 440 . In this example, the first vein and the second vein are each the same size. The first vein 443 as viewed at the first imaging plane 441 is one quarter the width of the first image plane 441 . The second vein 444 as viewed at the second imaging plane 442 is one sixth the width of the second image plane 442 . Accordingly when the images of the first and second veins are projected on the arm 446 on projection plane 440 , the first vein 443 will appear to be one quarter the width of the projection plane 440 , and the second vein 444 will appear to be one sixth the width of the projection plane 440 . It should be noted that neither the projected image of the first vein 443 nor the projected image of the second vein 444 is accurately representative of the actual vein size.
In accordance with the present invention, a scaling process can be performed prior to transmitting the image of the veins onto the projection image plane 440 . As previously described, the laser power of the 740 nm laser can be sequentially increased for each frame. A depth table correlating the depth of penetration of the 740 nm laser as a function of laser power can be pre-stored in memory. This depth information can then be used to correct the actual image size of the veins 443 and 444 prior to projecting their images onto projection plane 440 . The correction algorithm can be straight forward trigonometry and therefore is not described herein.
FIG. 11 describes an embodiment which accurately projects the correct vein size regardless of the depth of the veins 443 and 444 within the patients arm. The optical path diverges at an angle 447 and hits a parabolic minor 448 which is arranged to have a shape so that the optical beam 449 exiting off the mirror 448 is parallel and does not diverge. In this manner, the image of the veins. 443 and 444 are both the same size, and when they are projected onto projection plane 440 , the size of the vein images exactly matches that of the actual veins. As an alternative embodiment, a lens could be used instead of a parabolic mirror 448 for converting the diverging optical path to a parallel path.
As yet a further embodiment, it has been determined that increasing the wavelength of the laser light emitted from the laser 183 increases the depth of penetration into the flesh of the patient. This effect can be used to construct three dimensional images by increasing the wavelength of laser light emitted on sequential frames, thereby allowing the system to determine the depth of the veins (this is similar to the previous embodiment where the laser intensity was increased to obtain greater penetrations).
It should be noted that all embodiments herein have been described with a 740 nm laser 183 for imaging the veins/arteries. However, a broader range of wavelengths (700 nm to 1000 nm) could be utilized. Similarly, in the event a broader range of wavelengths are emitted by laser 183 , the 740 nm photo detector 182 could be changed to a different wavelength to receive the associated wavelength (700 nm-1000 nm). Still further, the 630 nm (red) laser 180 has been utilized for displaying the image on a patient. The 630 nm (red) laser 180 could be replaced with any visible laser (generally in the range of 400 nm-700 nm). Still further, the single (red) laser 180 could be replaced with multiple lasers configured so that they project coaxially. For example, if red, green and blue lasers are utilized, full color images can be rendered.
It also should be noted that often description is made of identifying vein, and in some cases veins and/or arteries. The invention is not limited thereto. Any portion of the body containing blood would be appropriately imaged by the devices of this invention. | An apparatus and method for creating a three dimensional imaging system is disclosed. There is a first source of laser light and a second source of laser light having a wavelength different from the wavelength of the laser light of the first source. The laser light from the first and second sources are combined, and the combined laser light is transmitted to a scanner. The scanner further transmits the combined light to a surface to be imaged. | 0 |
FIELD OF THE INVENTION
[0001] Embodiments of the present invention generally relate to the removal of lipopolysaccharides (LPS) from protein-lipopolysaccharide complexes.
BACKGROUND OF THE INVENTION
[0002] Lipopolysaccharide (LPS) is a major component of the outer membrane of gram negative bacteria. The endotoxic component of LPS is the lipid A portion. It comprises 1,6-linked D-glucosamine residues that are substituted with up to six acyl chains and a core polysaccharide structure to which additional polysaccharide repeating units may be attached. Endotoxin is a potent activator of the innate immune system at low doses while at higher doses endotoxin induces a number of other physical reactions including septic shock and death (Heine et al., 2001). Contamination of therapeutic products with endotoxins is therefore a primary concern for the manufacturers of such products.
[0003] Many recombinant proteins are produced in the gram negative bacteria Escherichia coli . The removal of LPS from these recombinant proteins can be a complicated but essential process especially if the proteins are destined for therapeutic uses. Many different processes have been developed for the removal of LPS from proteins based on the unique molecular properties of the endotoxin molecules. These include LPS affinity resins, two-phase extractions, ultrafiltration, hydrophobic interaction chromatography, ion exchange chromatography, and membrane adsorbers (reviewed by Petsch and Anspach, 2000). These procedures have varying degrees of success in the separation of LPS from proteins, which in a large part is dependent on the properties of the protein of interest.
[0004] Often, during the production of recombinant proteins, difficulties in the separation of LPS from proteins are encountered due to protein-LPS interactions. For example, and not by way of limitation, in recombinant proteins produced from an E. Coli expression system. Several of the published procedures for the separation of LPS from proteins have been investigated, including, but not necessarily limited to, denaturing hydrophobic interaction chromatography (Wilson et al., 2001) and the use of ethanol, isopropanol (Franken et al., 2000), or detergent (Fiske et al., 2001) washes while the protein was immobilized on ion-exchange chromatographic media.
[0005] Some experiments have shown that alcohol and detergent washes during ion exchange chromatography are effective in reducing the protein associated LPS levels while poor separation of LPS from the proteins was obtained by the denaturing HIC procedure. The detergents (Zwittergent 3-12 or 3-14) were shown to be more effective washing agents than the alcohols. Improved LPS clearance was also been achieved while the LPS-protein complexes were bound to a cation exchange resin as opposed to an anion exchange resin but the washing procedures used to remove LPS were effective on both matrices. When the wash procedure is performed on a cation exchanger, once the LPS-protein interactions have been disrupted the LPS should be washed out of the column while the protein is retained. During anion exchange chromatography, the LPS, being negatively charged at most pHs, remains bound to the resin along with the protein. Even though the alcohol and detergent washes were successful at reducing the levels of LPS in the LPS-protein complexes, scaling up and implementing any of these procedures in a manufacturing setting would not be practical. The concentrations of ethanol and isopropanol required to effectively reduce the LPS levels of the LPS binding proteins were greater than 50% (v/v). At these concentrations, these solutions are considered flammable liquids and as such impose many safety and operational restrictions.
[0006] The detergents, even though very effective at reducing LPS levels, are relatively expensive and would add significant cost to a manufacturing process and may affect the bioactivity of the protein of interest. Accordingly, Alternative chemicals are desired that could safely and cost effectively be used in place of the alcohols or detergents as washing agents for the separation of LPS from proteins during chromatographic unit operations. Ideally, these chemicals would be relatively inexpensive, well defined chemically, present minimal safety issues, and have minimal impact on the bioactivity of the protein in question when implemented into a process.
SUMMARY OF THE INVENTION
[0007] Embodiments of the present invention generally relate to the ability of alkanediols to separate lipopolysaccharides (LPS) or other endotoxins from proteins. In an embodiment, alkanediols are able to effect the separation of LPS from LPS-protein complexes. Accordingly, embodiments of the present invention generally relate to processes using alkanediols to effect separation of LPS from LPS-protein complexes. In further embodiments, the complexes are immobilized on a resin and the LPS separated therefrom.
BRIEF DESCRIPTION OF THE FIGURES
[0008] FIG. 1 a is an illustration of the SP Sepharose Fast Flow Elution Profile of BODIPY-LPS. The dotted line is UV signal at 280 nm and the solid line corresponds to BODIPY fluorescence expressed in relative fluorescence units (RFU).
[0009] FIG. 1 b is an illustration of the SP Sepharose Fast Flow Elution Profile of BODIPY-LPS-Transferrin Complex. The dotted line is UV signal at 280 nm and the solid line corresponds to BODIPY fluorescence expressed in relative fluorescence units (RFU).
[0010] FIG. 2 is an illustration of BODIPY-LPS Elution Profiles of BODIPY-LPS-Transferrin Complexes on SP Sepharose Fast Flow in Conjunction with Alkanediol Washes. BODIPY-LPS-transferrin complexes were generated, loaded onto a SP Sepharose Fast Flow column and the column washed with 50% solutions of 1,4-butanediol, 1,6-hexanediol, or 1,2-hexanediol.
[0011] FIG. 3 is an illustration of the reduction of BODIPY-LPS from BODIPY-LPS-Transferrin Complexes in SP Sepharose Fast Flow Eluates by Alkanediols. Zero percent reduction corresponds to a control run without an alkanediol wash. 1, 1,2-hexanediol; 2, 1% Zwittergent 3-14; 3, 1,6-hexanediol; 4, ethylene glycol; and 5, 1,4-butanediol.
[0012] FIG. 4 is an illustration of the reduction of BODIPY-LPS from BODIPY-LPS-BSA complexes in SP Sepharose Fast Flow eluates by Alkanediols. Zero percent reduction corresponds to a control run without an alkanediol wash. 1, 1,2-hexanediol; 2, 1% Zwittergent 3-14; 3, 1,2-butanediol; 4, 1,6-hexanediol; 5, 50% isopropanol; 6, 75% ethanol; 7, 1,4-butanediol; and 8, ethylene glycol.
[0013] FIG. 5 is an illustration of viscosities of Alkanediol, Isopropanol, Ethanol, and Zwittergent Solutions in 100 mM Acetate, pH 4.5. All solutions were prepared with 100 mM Acteate buffer, pH 4.5. 1, 50% 1,6-hexanediol; 2, 50% 1,2-hexanediol; 3, 50% 1,4-butanediol; 4, 50% 1,2-butanediol; 5, 50% Ethylene glycol; 6, 50% Isopropanol; 7, 75% Ethanol; 8, 1% Zw 3-14; and 9, 100 mM Acetate, pH 4.5.
DETAILED DESCRIPTION OF THE INVENTION
[0014] As used herein, the term “alkanediol” means and refers to a non-aromatic saturated hydrocarbon with the general formula C n H 2n (OH) 2 .
[0015] As used herein, the terms protein-LPS complex and LPS-protein complex shall be synonymous. The protein-LPS complex may be a loose association, such as, for example and not by way of limitation, by intramolecular forces/intermolecular forces, or binding.
[0016] Generally, embodiments of the present invention relate to processes for separating lipopolysaccharides or endotoxins from protein-lipopolysaccharide (or other endotoxin comprising substance) complexes. In an embodiment, a process for separating lipopolysaccharides from protein-lipopolysaccharide complexes comprises the step of washing a protein-LPS complex with an alkanediol containg solution whereby at least a portion of the LPS is removed and/or separated from the protein.
[0017] In an embodiment, the LPS-protein complex (or other endotoxin complex) is produced and/or formed during the production of proteins, such as, but not limited to recombinant proteins.
[0018] Embodiments of the present invention may use any protein. Various examples include, but are not limited to, Bovine albumin (BSA), bovine holo-transferrin, lactoferrin from bovine milk, lysozyme from chicken egg whites, heat shock proteins, heat shock fusion proteins and the like. The various proteins may be simple or complex, small or large.
[0019] Various processes and/or expression systems may be used for the production of recombinant proteins. Any expression system may be used for the production of recombinant proteins. In an embodiment, the expression system is bacterial. In such embodiments, gram negative bacterial expression systems may be used, such as an E. coli expression system. However, other types of bacterial systems may also be used, for example, and not by way of limitation, Caulobacter crescent and Proteus mirabilis.
[0020] In general, any system comprising endotoxin(s) can use embodiments of the present invention to separate the endotoxin from the protein. For example, in an embodiment endotoxin(s) are an impurity in a system comprising proteins. It is well known in the art that endotoxin(s) can, in some instances, be found as contaminants in raw materials or during processing. Such endotoxins can be removed and/or separated by various embodiments of the present invention.
[0021] Any alkanediol may be used with various embodiments of the present invention. Suitable, non-limiting examples include, 1,5-pentanediol, 1,6-hexanediol, 1,2-hexanediol, 1,2-butanediol, 1,4-butanediol, and 1,7-heptanediol. In an embodiment, alkanediols of the present invention are long chain alkanediols. Alkanediols provide increased safety over the commonly used eluents, like acetonitrile, ethanol, and methanol, since the alkanediols are all nonflammable compounds. Further, alkanediols are soluble in water and they are not cost prohibitive for a large number of processes.
[0022] In other embodiments, various processes are utilized to assist and/or facilitate separation of the protein-LPS complex. In various examples of these embodiments, the protein-LPS complex is attached to a substrate. Various methods of attachment include retaining, attracting, binding, applying, immobilizing and/or removably affixing to a substrate. Either the protein or the LPS may be attached. In an embodiment, the LPS-protein complex is bound or immobilized on a resin. Suitable resin types include, but are not limited to affinity resins, anion exchange resins, cation exchange resins, and the like, such as a SP Sepharose Fast Flow resin (SPSFF resin). However, the choice of resins is a matter of routine skill in the art and can be made to serve the particular needs of the process.
[0023] In an embodiment, the LPS-protein complex is bound to an ion exchange resin under conditions such that the protein binds to the resin of the column. An alkanediol wash solution is then applied to the column whereby at least a portion of the LPS is separated from the LPS-protein complex and elutes with or about the alkanediol. In an embodiment, greater than 50% of the LPS is separated from the LPS-protein complex. In an alternate embodiment, greater than 75% of the LPS is separated from the LPS-protein complex. In another embodiment, greater than 80% of the LPS is separated from the LPS-protein complex. In yet another embodiment, greater than 85% of the LPS is separated from the LPS-protein complex. In an alternate embodiment, greater than 90% of the LPS is separated from the LPS-protein complex. In another embodiment, greater than 95% of the LPS is separated from the LPS-protein complex. In another embodiment, greater than 97% of the LPS is separated from the LPS-protein complex. In another embodiment, greater than 99% of the LPS is separated from the LPS-protein complex. In another embodiment, greater than 99.9% of the LPS is separated from the LPS-protein complex.
[0024] In an embodiment, after separation and/or removal of the LPS, the protein can be eluted from the resin. The protein may eluted by means common in the art and as appropriate for the resin. In an example, for ion exchangers changes in pH and/or increased conductivity can be used to elute the protein.
[0025] In an embodiment, 50% of the protein eluted from the resin is free of LPS or other endotoxin. In an alternate embodiment, 75% of the protein eluted from the resin is free of LPS or other endotoxin. In an alternate embodiment, 80% of the protein eluted from the resin is free of LPS or other endotoxin. In an alternate embodiment, 85% of the protein eluted from the resin is free of LPS or other endotoxin. In an alternate embodiment, 90% of the protein eluted from the resin is free of LPS or other endotoxin. In an alternate embodiment, 95% of the protein eluted from the resin is free of LPS or other endotoxin. In an alternate embodiment, 97% of the protein eluted from the resin is free of LPS or other endotoxin. In an alternate embodiment, 99% of the protein eluted from the resin is free of LPS or other endotoxin. In an alternate embodiment, 99.9% of the protein eluted from the resin is free of LPS or other endotoxin.
[0026] In various embodiments, another wash is utilized to remove/separate the protein from the resin. In an alternate embodiment, the protein elutes without a wash, such that the resin only slowed the protein elution, thereby separating the LPS from the protein. The degree of separation can be varied depending upon the resin used. Likewise, a resin can be constructed to change the elution profile of the LPS-protein complex such that the LPS or protein component elutes at a different time than the other component.
[0027] Accordingly, various embodiments of the present invention comprise processes such as:
[0028] A process for removing an endotoxin from recombinantly produced proteins comprising a Lipopolysaccharide (LPS)-protein complex comprising the steps of:
[0029] immobilizing the complex to an ion exchange resin;
[0030] washing the resin with an alkanediol whereby at least a portion of the LPS is separated from the complex; and,
[0031] eluting at least a portion of the protein from the resin.
[0000] In alternate embodiments, the LPS is affixed to the resin and the protein is first eluted.
[0032] In further embodiments, the present invention comprises a process for disrupting a lipopolysaccharide (LPS)-protein complex comprising washing the complex with an alkanediol.
[0033] In yet further embodiments, the present invention comprises processes for increasing the retention time of a protein on a resin comprising the step of washing the resin with an alkanediol. In an example of such an embodiment, after a wash with a hexanediol, such as 1,2-hexanediol, to remove the LPS, increasing the salt concentration on the resin fails to elute the protein. Such embodiments are useful for high salt environments and where one may wish to alter the selectivity of the resin for proteins.
[0034] Accordingly, embodiments of the present invention further comprise methods of separating LPS from a protein-LPS complex in a high salt, conductivity, environment comprising the steps of:
[0035] immobilizing the complex to an ion exchange resin;
[0036] washing the resin with 1,2-hexanediol whereby at least a portion of the LPS is separated from the complex; and,
[0037] eluting at least a portion of the protein from the resin by modifying the pH. In preferred embodiments of this type, the concentration of alkanediol is greater than about 5%. However, any concentration may be used.
[0038] While the invention has been described in connection with specific embodiments thereof, it will be understood that it is capable of further modifications and the appended Claims are intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains and as may be applied to the essential features hereinbefore set forth whether now existing or after arising. Further, while embodiments of the invention have been described with specific dimensional characteristics and/or measurements, it will be understood that the embodiments are capable of different dimensional characteristics and/or measurements without departing from the principles of the invention and the appended Claims are intended to cover such differences. Furthermore, all patents mentioned herein are herby incorporated by reference.
[0039] For a further understanding of various embodiments of the present invention, reference should be had to the following examples:
EXAMPLES AND EXPERIMENTS
[0000] Materials
[0040] Bovine albumin (BSA), bovine holo-transferrin, lactoferrin from bovine milk, lysozyme from chicken egg whites, lipopolysaccharides from Escherichia coli serotype O55:B5, and BSTFA were purchased from Sigma Chemical Co. (St. Louis, Mont.). Acetic acid, Tris (base), sodium hydroxide (NaOH), hydrochloric acid, sodium chloride (NaCl), ethanol, isopropanol, sodium dodecyl sulfate (SDS), and sodium phosphate dibasic 7-hydrate were purchased from J.T. Baker Chemical Co. (Phillipsburg, N.J.). 1,6-Hexanediol was from BASF Co. (Mount Olive, N.J.). 1,2-Hexanediol, 1,2-butanediol, and Zwittergent 3-14 (Zw 3-14) were purchased from Fluka (Milwaukee, Wis.). 1,4-Butanediol and ethylene glycol were purchased from Aldrich (Milwaukee, Wis.). Phosphate buffered saline (PBS), 10×, was purchased from Bio-Rad Laboratories, Inc. (Hercules, Calif.). Escherichia coli BODIPY® FL conjugate lipopolysaccharide, serotype O55:B5, (BODIPY-LPS) and EnzChek Lysozyme Assay Kit were purchased from Molecular Probes, Inc. (Eugene, Oreg.). Pyrosol, Limulus Amebocyte Lysate (LAL) Pyrotell-T, LAL reagent water (LRW), and control standard endotoxin from E. coli O 113:H10 (CSE), were obtained from Associates of Cape Cod, Inc. (Falmouth, Mass.). SP Sepharose fast flow (SPFF) resin, Q Sepharose fast flow (QFF) resin, and HR 10/10 columns were from Amersham Biosciences (Piscataway, N.J.). Clear polystyrene 96-well microtiter plates were from Associates of Cape Cod, Inc. (Falmouth, Mass.) and black 96-well microtiter plates from NUNC (Rochester, N.Y.). β-Hydroxytetradecanoic acid, β-hydroxytridecanoic acid, β-hydroxyundecanoic acid, β-hydroxytridecanoate, β-hydroxytetradecanoate, and β-hydroxyundecanoate were purchased from Matreya, Inc. (Pleasant Gap, Pa.). Heptane was purchased from Spectrum (New Brunswick, N.J.).
[0000] Methods
[0041] Viscosity Measurements
[0042] A Brookfield Model 1 LVT Viscometer equipped with a ULA-Y adapter (Middleboro, Mass.) was used for viscosity determinations. All measurements were performed at 20° C.
[0043] LPS-Protein Complex Formation
[0044] Protein stock solutions were prepared in the column equilibration buffers to a final concentration of 10 to 11 mg/ml. LPS O55:B5 stock solution was prepared in Milli-Q water and BODIPY-LPS stock solution was prepared in PBS or column equilibration buffers to a final concentration of 1 mg/ml. This is approximately 100 μM final concentration based on a molecular weight of O55:B5 LPS of 10,000 Da.
[0045] The LPS-protein complexes were formed by adding to a polypropylene tube 1 part LPS solution to 9 parts protein solution, v/v. The tube was vortexed, wrapped in aluminum foil, and then incubated at room temperature for 16 to 72 hours for BSA and transferrin or incubated at 37° C. for at least 4 hours for lactoferrin.
[0046] LAL and BODIPY Analysis
[0047] A SpectraMax Gemini XS microplate spectrofluorometer from Molecular Devices Co. (Sunnyvale, Calif.) was used for the BODIPY-LPS fluorescent microplate assay and a SpectraMax 190 microplate spectrophotometer (Molecular Devices) for the LAL kinetic turbidimetric assay (KTA). Reference materials were analyzed in triplicate and samples either in duplicate or triplicate. The results were plotted and analyzed using SOFTmax PRO software version 3.1.1 (Molecular Devices).
[0048] A. BODIPY-LPS Assay
[0049] Three fold serial dilutions of the BODIPY-LPS stock solution were prepared from 0.81 to 0.03 μM. The analytical procedure of the BODIPY-LPS assay was a modification of the assay used by Yu and Wright (1996) as follows. To each well of a black microtiter plate 20 μl of 15% SDS, prepared in Milli-Q water, followed by 180 μl sample or standard were added. The plate was shaken for 10 seconds at 37° C. and read immediately in fluorescence mode. The optimal excitation (490 nm), emission (525 μm), and cutoff wavelengths (515 nm) were determined for the BODIPY-LPS. The assay for BODIPY-LPS demonstrated a linear range from 0.03 to 0.81 μM (54 to 1458 ng) with a limit of detection of/LOQ values less than 0.01 μM (18 ng) and a limit of quantification of 0.03 μM (54 ng).
[0050] B. LAL Kinetic Turbidimetric Assay (KTA)
[0051] Samples were adjusted to a pH between 6 and 8 with Pyrosol, if needed. CSE and Pyrotell-T were reconstituted with LRW. The linear curve of CSE was from 0.03 to 1.00 EU/ml. The analytical procedure of LAL KTA was as follows. To each well of a clear polystyrene microtiter plate 100 μl of sample or standard and 100 μl of Pyrotell-T were added. For spiked samples, 5 μl of 2.00 EU/ml CSE was added to obtain 0.10 EU/ml CSE level. The plate was shaken for 10 seconds and data collected, every minute, in the kinetic mode at 405 nm for 1 hour at 37° C.
[0052] C. LPS Analysis by Gas Chromatography
[0053] Quantitative analysis for the relative level of LPS present in samples by gas chromatography mass spec (GCMS) was based on the method by Mielniczul et al. (1992) and utilized a 6890 gas chromatograph with a 5973 mass selective detector from Agilent (Foster City, Calif.). The column used was a DB-5MS column (30 cm×0.25 mm i.d.×0.25 μm film thickness) from J&W Scientific (Foster City, Calif.). The linear curve for surrogate and target compounds ranged from 1.6 to 100 pg/μl and the internal standard was kept constant at 50 pg/μl. Briefly, the method of sample preparation and GCMS analysis were as follows. Samples and a known amount of surrogate, β-hydroxytridecanoic acid, were added to 5 ml glass reaction vials. Aqueous samples were hydrolyzed in 6 N HCl at 90 to 100° C. overnight to liberate β-hydroxytetradecanoic acid from LPS. The fatty acids were extracted twice from the hydrolysate with heptane and then dried under nitrogen. The fatty acids were methylated by incubation at 80 to 90° C. in 3 N methanolic HCl for 30 minutes. Water was added to quench the reaction and then the methyl esters extracted twice with heptane. The methyl esters were then dried under nitrogen. The methyl esters were derivatized by adding BSTFA/pyridine (2:1, v/v) and incubating at 80 to 90° C. for 15 to 20 minutes before undergoing the final drying step under nitrogen. Samples were reconstituted with a 50 pg/μl internal standard, methyl-3-trimethylsilyl-undecananoic acid, prepared in heptane. Standards and samples were injected in splitless mode and at 1 μl injection volume. Initial oven temperature was held at 90° C. for 4 minutes and then ramped at 20° C. per minute to 250° C. followed by a 10° C. per minute ramp to 300° C. The mass spectrometer was set for an EM offset voltage of 500 and the solvent delay at 5.2 minutes. Selective ion monitoring was used to monitor methyl-3-TMS-undecanoate at ions 175 and 273, methyl-3-TMS-tridecanoate at 11.0 minutes and ions 175 and 301, and methyl-3-TMS-tetradecanoate at 11.7 minutes and ions 175 and 315. Chromatograms were reported using Chemstation for MSD Productivity software.
[0054] Lysozyme Assay
[0055] Lysozyme activity was determined using the EnzChek Lysozyme Assay Kit according to the manufacturers instructions.
[0056] Chromatography
[0057] All chromatography was performed on ÄKTA explorer 100 FPLC systems (Amersham Biosciences) equipped with a gradient pump (P-900), a 500 μl or 2000 μl injection loop, a variable wavelength detector (UV-900), and a pH and conductivity monitor (pH/C-900). All chromatographic experiments were performed at a flow rate of 200 to 300 cm/hr at ambient temperature. During the alkanediol washes the flow rate was dropped to 150 to 200 cm/hr to minimize the increase in system back pressure due to the increased viscosity of the alkanediol solutions. Chromatograms were reported using Unicorn software version 3.21 or 4.0. The resins were packed in 1 cm diameter columns to bed heights of 7 to 11 cm. The ÄKTAs and columns were sanitized either with 0.5 N NaOH for 60 to 120 minutes or 0.1 N NaOH for greater than 16 hours before each chromatographic run. The column and ÄKTAs were then rinsed with Milli-Q water just prior to system equilibration with the appropriate buffers.
[0058] Alkanediols, ethanol, and isopropanol were prepared as v/v solutions with the same chemical compositions and pH as the equilibration buffers, while 1,6-hexanediol and Zwittergent 3-14 were prepared as w/v solutions.
[0059] D. Cation Exchange Chromatography
[0060] For transferrin, a SP Sepharose Fast Flow column was charged with 100 mM Acetate, 1 M NaCl, pH 5, and equilibrated with 100 mM Acetate, pH 5. After loading, the resin was washed with the equilibration buffer and then eluted with 50 mM sodium phosphate, 1 M NaCl, pH 7.5. When an organic or detergent wash was performed, it was applied after the initial wash step and was for 6 CV unless otherwise stated. This wash was followed by a second wash with equilibration buffer to remove the organic or detergent prior to elution.
[0061] The chromatography for BSA was identical to that of transferrin except that the pH of all chromatography buffers was 4.5. When 1,2-hexanediol was used as the washing agent, the eluent was changed to 50 mM sodium phosphate, 1 M NaCl, pH 7.5.
[0062] Lactoferrin chromatography was similar to transferrin except that the resin was charged with 1 M sodium chloride, 20 mM sodium phosphate, pH 7.5, equilibrated in 20 mM sodium phosphate, pH 7.5, and eluted with 1 M sodium chloride, 20 mM sodium phosphate, pH 7.5.
[0063] The chromatography for lysozyme was similar to that for transferrin except that the resin was charged with 1 M NaCl, 20 mM Tris, pH 8.0, equilibrated in 50 mM Tris, pH 8.0 and eluted with 1 M NaCl, 20 mM Tris, pH 8.0.
[0064] E. Anion Exchange Chromatography
[0065] For BSA, a Q Sepharose Fast Flow column was charged with 50 mM Tris, 1 M NaCl, pH 8.0 and equilibrated with 50 mM Tris, pH 8.0. After loading, the resin was washed with equilibration buffer. BSA was eluted with 25 mM Acetate, pH 4.5, and LPS with 25 mM Acetate, 1 M NaCl, pH 4.5. When an alkanediol wash was performed, it was inserted after the initial wash step and was for 6 CV. This wash was followed by a second wash with equilibration buffer to remove the alkanediol.
[0000] Results and Discussion
[0066] Table I summarizes the molecular weights and isoelectric points of the proteins used in this study. BSA, transferrin, and lactoferrin have all been shown to bind LPS (Dzarski, 1994; Berger and Beger, 1987; and Appelmelk et al., 1994). Lysozyme was used to assess the effects of the washing agents on enzyme activity.
TABLE I Molecular Weights and Isoelectric Points of Proteins Used in this Study Protein Molecular Weight pI Albumin, bovine fatty acid free low 66400 5.56 endotoxin Transferrin, bovine holo 75800 6.5 Lactoferrin, bovine 75200 8.52 Lysozyme, chicken egg white 14300 9.65
[0067] Table II summarizes some of the physical properties of the alkanediols used in this study. Also included are ethanol and isopropanol, which have been used for LPS removal in other processes (Franken et al., 2000), for comparison.
TABLE II Physical Properties of Alkanediols Used in this Study 1 Boiling 1 Melting 1 Flash 2 Explosion limits, air 2 Autoignition Compound Point (° C.) Point (° C.) Point (° C.) Lower Upper (° C.) 1,2-hexanediol 223 NA 122 NA NA 390 1,6-hexanediol 250 45 147 6.6% 16% 319 1,5-pentanediol 242 −16 129 1.4% 13.2% NA 1,2-butanediol 194 −50 93 2.4% 13.5% 390 1,4-butanediol 230 16 121 1.95% 18.3% 420 1,3-propanediol 214 −27 131 NA NA 400 1,2-ethanediol 195 −13 111 3.2% 15.3% 400 Ethanol 78.3 −114.1 12 3.3% 19% 363 Isopropanol 82.4 −88.5 12 2.5% 12% 460 1 data obtained from CabridgeSoft Corp. at Chemfinder.com 2 data from Material Data Safety Sheets NA, not available
Separation of LPS-Protein Complexes by Organics and Detergent
[0068] SP Sepharose Fast Flow Chromatography of LPS and LPS-Protein Complexes
[0069] The LPS elution profiles of LPS by itself and LPS-BSA complexes on SP Sepharose Fast Flow resin were determined by LAL-KTA analysis of selected column fractions (Table III). When LPS was chromatographed by itself the LPS was detected primarily in the wash-unbound fraction as expected. Chromatography of the LPS-BSA complexes resulted in the majority of the LPS being detected in the BSA eluate fraction confirming the LPS binding property of BSA (Dziarski, 1994) and demonstrating that the BSA-LPS complexes are stable under cation exchange chromatography conditions employed.
TABLE III SPFF Chromatography Elution Profiles of LPS and LPS-BSA LPS and LPS-BSA complex were chromatographed on SP Sepharose Fast Flow. Column fractions were analyzed for LPS by the LAL KTA as described in the methods. BODIPY-LPS (% Recovery) Sample Load Wash-unbound Elution BODIPY-LPS 100 82 5 BODIPY-LPS-BSA Complex 100 3 90
[0070] The LAL KTA is a laborious and costly assay to use to determine the distribution of LPS in the column fractions. A fluorescent based assay for LPS was developed to monitor the column fractions. This assay used fluorescently tagged LPS, BODIPY-LPS, in place of the non-labeled LPS, which allows for the quick analysis of the column eluates by fluorescence spectroscopy. The fluorescence of the BODIPY maker in the BODIPY-LPS conjugate has been shown to be quenched when the LPS is complexed with itself or protein. Addition of SDS to the sample disrupts the LPS-LPS or LPS-protein complexes and results in an increase in fluorescence (Yu and Wright, 1996). The assay was developed as a microtiter plate based assay that allowed for the quick and quantitative analysis of BODIPY-LPS in the chromatography fractions.
[0071] To determine if the BODIPY marker interfered with BSA-LPS complex formation or behaved differently during cation exchange chromatography the preceding analysis was repeated using BODIPY-LPS and BODIPY-LPS-protein complexes. The elution profiles of BODIPY-LPS and BODIPY-LPS-protein complexes were similar (Table IV) to the elution profiles of LPS and LPS-BSA above. This demonstrates that the BODIPY marker does not interfere with the ability of BSA or transferrin to bind LPS and that the BODIPY group does not alter the chromatographic profile of the LPS. FIG. 1 shows typical SP Sepharose Fast Flow profiles for BODIPY-LPS (A) and the BODIPY-LPS-transferrin complex (B).
TABLE IV SPFF Chromatography Elution Profiles of BODIPY-LPS and BODIPY-LPS-Protein BODIPY-LPS and BODIPY-LPS-protein complex were chromatographed on SP Sepharose Fast Flow. Column fractions were analyzed for BODIPY-LPS by the BODIPY assay as described in the methods. BODIPY-LPS (% Recovery) Sample Load Wash-unbound Elution BODIPY-LPS 100 82 5 BODIPY-LPS-BSA Complex 100 2 90 BODIPY-LPS-Transferrin 100 6 74 Complex
Reduction of LPS from LPS-Protein Complexes by Alkanediols During SP Sepharose Fast Flow Chromatography
[0072] Initial experiments examined the capability of a 50% 1,6-hexanediol wash step to reduce the amount of BODIPY-LPS complexed with BSA during cation exchange chromatography. A 3 column volume (CV) wash with 1,6-hexanediol lowered the amount of BODIPY-LPS complexed with BSA by about 21%. Increasing the length of the 1,6-hexanediol wash step from 3 CV to 6 CV improved the removal of BODIPY-LPS from the BSA complex to about 49%. While an additional 3 CV increase in the 1,6-hexanediol wash step to 9 CV provided improvement (51%) in BODIPY-LPS removal. All additional experiments were carried out with a 6 CV alkanediol wash step.
[0073] The effectiveness of a series of alkanediols to remove LPS from proteins while the proteins were bound to ionic solid supports were compared to those of ethanol, isopropanol, and Zwittergent 3-14, which had been shown to be effective in removing LPS from a LPS binding protein. A SP Sepharose Fast Flow column was loaded with BODIPY-LPS-transferrin complex. The resin was washed with six column volumes of a 50% alkanediol solution and then eluted. Fractions were collected and assayed for BODIPY-LPS ( FIG. 2 ). As the chain length of the alkanediol was increased from four to six carbons, the fluorescence of the alkanediol wash fractions increased while the fluorescence of the eluate fractions decreased. This demonstrated that alkanediols removed BODIPY-LPS from the transferrin complex. FIGS. 3 and 4 illustrate the effects of alkanediol structure on BODIPY-LPS removal from transferrin and BSA, respectively. BODIPY-LPS removal efficiency increased with increasing alkanediol chain length and the 1,2-alkanediol isomers were more effective than the terminal alkanediols at removing the BODIPY-LPS. 1,2-hexanediol was the most efficient compound tested and out performed the detergent and alcohols. 1,2-butanediol and 1,6-hexanediol as well as 50% isopropanol and 75% ethanol reduced the BODIPY-LPS associated with transferrin to similar levels. The removal of BODIPY-LPS by the alkanediols was similar for both the transferrin and BSA complexes.
[0074] Reference to FIG. 2 illustrates BODIPY-LPS Elution Profiles of BODIPY-LPS-Transferrin Complexes on SP Sepharose Fast Flow in Conjunction with Alkanediol Washes.
[0075] FIG. 3 illustrates the Reduction of BODIPY-LPS from BODIPY-LPS Transferrin Complexes in SP Sepharose Fast Flow Eluates by Alkanediols. Chromatography was as described in FIG. 2 . Zero percent reduction corresponds to a control run without an alkanediol wash. 1, 1,2-hexanediol; 2, 1% Zwittergent 3-14; 3, 1,6-hexanediol; 4, ethylene glycol; and 5, 1,4-butanediol. BODIPY-LPS-transferrin complexes were generated, loaded onto a SP Sepharose Fast Flow column and the resin washed with 50% solutions of 1,4-butanediol, 1,6-hexanediol, or 1,2-hexanediol. Following a wash to remove the alkanediol, transferrin was eluted as described in the methods. Sanitization between runs was with 0.5 N NaOH.
[0076] FIG. 4 illustrates The reduction of BODIPY-LPS from BODIPY-LPS-BSA complexes in SP Sepharose Fast Flow eluates by alkanediols. Chromatography was as described in FIG. 2 . Zero percent reduction corresponds to a control run without an alkanediol wash. 1, 1,2-hexanediol; 2, 1% Zwittergent 3-14; 3, 1,2-butanediol; 4, 1,6-hexanediol; 5, 50% isopropanol; 6, 75% ethanol; 7, 1,4-butanediol; and 8, ethylene glycol.
[0077] It was noted during the experiments on transferrin utilizing 1,2-hexanediol in the wash that when the pH of the elution buffer was maintained at a pH of 5, including 1 M NaCl, that the transferrin was not eluted from the resin. Increased retention of transferrin was observed down to a 1,2-hexanediol concentration of 10%. At a 1,2-hexanediol concentration of 5%, transferrin retention was not altered. The alteration in retention times has been observed for other proteins during ion exchange chromatography in the presence of polyethylene glycol and other neutral polymers (Milby et al., 1989 and Gagnon et al., 1996). The changes in protein retention times were dependent on polyethylene glycol size and concentration and the protein itself. Whereas, ethylene glycol up to a concentration of 40% did not effect protein retention times (Tauc et al., 1998). It is worth while to note that in these instances the compound under investigation were included in all the chromatography buffers. For the 1,2-hexanediol, it was only included in a wash buffer that was then removed by an additional wash step prior to elution of the protein.
[0078] Since 1,2-hexanediol was the most effective compound tested for removing BODIPY-LPS from both transferrin and BSA, the concentration dependence of the 1,2-hexanediol wash needed to affect this removal was investigated. The reduction of BODIPY-LPS in the SP Sepharose Fast Flow BSA eluate fraction was determined after 1,2-hexanediol washes containing 5%, 20%, and 50% 1,2-hexanediol. The 5% 1,2-hexanediol wash resulted in about a 55% decrease in the BSA associated BODIPY-LPS while the reduction of BODIPY-LPS by the 20% and 50% 1,2-hexanediol washes were comparable at approximately 96%.
[0079] In addition to transferrin and BSA, the removal of BODIPY-LPS from lactoferrin complexes by 1,6-hexanediol was also examined by the fluorescent BODIPY assay. The results of the analysis were then confirmed by analysis of the samples for the LPS marker compound 3-OH-14:0 fatty acids by GC-MS. Table V summarizes the data and again demonstrates the ability of an alkanediol, in this case 1,6-hexanediol, wash during the chromatography to reduce the levels of BODIPY-LPS in the lactoferrin eluate. Approximately and 87% reduction of BODIPY-LPS was observed by the BODIPY fluorescence assay and a 91% reduction in the LPS marker by the GC-MS assay.
TABLE V SPFF Chromatography Elution Profiles of BODIPY-LPS and BODIPY-LPS-Lactoferrin Complexes BODIPY-LPS-lactoferrin complexes were generated, loaded onto a SP Sepharose Fast Flow column. For runs that included a 50% solution of 1,6-hexanediol, a wash to remove the 1,6-hexanediol was included prior to elution of lactoferrin as described in the methods. Column fractions were assayed for BODIPY and 3-OH-14:0 fatty acids as described in the methods. BODIPY-LPS (% Recovery) GCMS assay/Fluorescence BODIPY assay Sample Load Wash-unbound Diol wash Eluate BODIPY-LPS 100 (GCMS) 94 1 N/A 5 (no diol wash) 100 (fluor) 89 N/A 7 BODIPY-LPS- 100 62 N/A 48 Lactoferrin (no diol wash) 100 60 N/A 46 BODIPY-LPS- 100 63 2 ND 4 Lactoferrin (+ diol wash) 100 66 26 6 1 N/A—Not applicable. 2 ND—Could not be determined by GCMS.
[0080] During the chromatographic runs, a rise in the system back pressure was noted when the alkanediol washes were applied. The viscosity of each organic solutions and the Zwittergent solution, prepared in 100 mM Acetate, pH 4.5, were measured ( FIG. 5 ). The viscosity of the alkanediols increased with carbon chain length while the viscosity of the 1,2-alkanediol isomers were slightly less than the terminal alkanediol isomers. The increased viscosity of the alkanediol solutions may present some difficulties in scale-up. Column flow rates may have to be adjusted to maintain suitable system pressure for the equipment in use. Being able to use lower concentrations of the alkanediols to remove LPS from the protein-LPS complexes would partially alleviate this problem. For example, 20% and 50% 1,2-hexanediol washes effectively reduce the BODIPY-LPS to approximately the same levels for BSA complexes as indicated above. The viscosity of 20% 1,2-hexanediol is about one third that of 50% hexanediol, 2.6 Cp compared to 7.5 Cp.
[0081] Reduction of LPS from LPS-Protein Complexes by Alkanediols during Q Sepharose Fast Flow Chromatography
[0082] Removal of LPS from LPS-protein complexes is more complex on anion exchange resins, especially for basic proteins. During cation exchange chromatography, the LPS, being negatively charged, is not attracted to the functional group of the resin and is washed out of the column during the alkanediol wash while the protein remains bound under the wash conditions. During anion exchange chromatography, the LPS and the protein both are retained by the resin's functional groups. Therefore the complexes need to be disrupted and differential elution of the protein and LPS must occur.
[0083] The ability of 1,6-hexanediol and 1,2-hexanediol to reduce the BODIPY-LPS levels of BSA-LPS complexes during anion exchange chromatography on Q Sepharose Fast Flow resin was investigated. The two isomers, 1,2- and 1,6-, of hexanediol were chosen since these were the most effective compounds at reducing the levels of BODIPY-LPS from protein complexes during cation exchange chromatography.
[0084] The elution of the BSA from the anion exchange resin after the application of a 1,2-hexanediol wash was altered as was observed for transferrin on the cation exchange resin. Increasing the salt concentration of the elution buffer to affect the elution of BSA after the 1,2-hexanediol wash resulted in the coelution of free BODIPY-LPS with the BSA. An alternative elution scheme was chosen based on pH. After the 1,2-hexanediol wash was complete and a wash out of the 1,2hexanediol had occurred, the BSA was eluted at pH 4.5. This was followed by a strip of the resin, which brought off the remaining BODIPY-LPS, with a pH 4.5 buffer containing 1 M NaCl. Table VI summarizes the effect of 1,2-hexanediol on the removal of BODIPY-LPS from BODIPY-LPS-BSA complexes. Inclusion of the 1,2-hexanediol wash reduced the BODIPY-LPS of the BSA eluate by about 29% with an apparent elution of the displaced BODIPY-LPS to the 1,2-hexanediol wash fractions.
TABLE VI The QFF Elution Profiles of BODIPY-LPS and BODIPY-LPS-BSA Complexes. BODIPY-LPS and BODIPY-LPS-BSA complex were chromatographed on Q Sepharose Fast Flow. Column fractions were analyzed for BODIPY-LPS by the BODIPY assay as described in the methods. BODIPY-LPS (% Recovery) Wash- Sample Load unbound Diol wash Elute Strip BODIPY-LPS 100 1 1 NA 0 42 (no diol wash) BODIPY-LPS-BSA 100 7 NA 17 52 (no diol wash) BODIPY-LPS-BSA 100 2 12 5 45 (+ diol wash) 1 NA—Not applicable.
Alkanediol Effect on Enzymatic Activity
[0085] Lysozyme was used to determine the effect of the washing agents on enzymatic activity and thereby, indirectly the denaturing effects of the washing agents during SP Sepharose Fast Flow chromatography. Lysozyme was chromatographed with and without a 6 CV %50 1,6-hexanediol wash or 1,2-hexanediol wash and the column loads and eluates assayed for lysozyme activity using a fluorescence microplate lysozyme activity assay. The hexanediol washes had no detrimental effects on lysozyme activity. 75% ethanol, 50% isopropanol, and 1% Zwittergent 3-14 washes also had no effect on lysozyme activity.
REFERENCES
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13. Appelmelk, B. J., An, Y. Q., Geerts, M., Thijs, B. G., de Boer, H. A., MacLaren, D. M., de Graaff, J., and Nuijens, J. H. (1994) Lactoferrin is a lipid A-binding protein. Infect. Immun, 62, 2628-2632.
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[ i ] T. A. Hauser and K. J. Hayenga, World Intellectual Property Organization , International Publication Number WO02/074791 A1 (2002).
[ ii ] R. L. Fahrner, P. M. Lester, G. S. Blank, and D. H. Reifsnyder, J. Chromatogr. A 830 (1999) 127-134.
[ iii ] R. L. Fahrner and D. Reifsnyder U.S. Pat. No. 6,265,542 B1 (2000). | During the production of recombinant proteins from gram negative bacteria, lipopolysaccharides (LPS, endotoxin) are released along with the protein of interest. In many instances, LPS will copurify with the target protein due to specific or non-specific protein-ILPS interactions. We have investigated the ability of alkanediols to effect the separation of LPS from protein-LPS complexes while the complexes are immobilized on anion or cation exchange chromatographic media. Alkanediols provide a safer alternative to the use of other organics such as alcohols or acetonitrile due to their lower toxicity and decreased flammability. In addition, they are less costly than many of the detergents that have been used for such purposes. LPS removal efficiency increased with increasing alkane chain length. 1,2-alkanediols were more effective than terminal alkanediols in the separation of LPS from protein LPS complexes. | 1 |
RELATED APPLICATION
This application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Application No. 60/540,905, filed Jan. 30, 2004, the entireties of which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention generally relates to the methods through which household appliances can provide intuitive and enhanced interactivity through visual inputs. In particular, the disclosure presents methods relating to control of a household appliance, such as a microwave or a refrigerator, via recognition of visual indicia, such as graphics, text, and the like, using a visual sensor such as a camera.
2. Description of the Related Art
In a typical household environment, consumers interact with a variety of household appliances. Generally, consumers interact with household appliances and provide inputs to the appliances by touching the appliances. For example, a user of a microwave generally sets the mode of the microwave's operation, such as the time and power of the microwave's operation, through the use of a keypad located on the microwave. By way of further example, a user of a washing machine generally sets the mode of the washing machine's operation, such as the time and temperature of the wash, through the use of dials, levers, knobs, and the like located on the washing machine.
Recently, consumers have become able to control household appliances through other input methods. For example, an Internet-enabled washing machine, such as the washing machine from LG Electronics of South Korea, see Williams, Martyn, Surf Among Suds With Web - Enabled Washing Machine , [online], [retrieved on 2004-01-29], retrieved from the Internet <URL: http://www.pcworld.com/news/article/0,aid,32128,00.asp>, can receive operating instructions from an Internet web site, instead of, or in addition to manual input from the user. As another example, the SeasonPass™ service offered by TiVo, Inc., [online], [retrieved on 2004 Jan. 29], retrieved from the Internet <URL: http://www.tivo.com/1.3.1.asp>, can retrieve television programming schedules from an Internet web site or other remote source, instead of, or in addition to receiving operating instructions via manual input from the user.
SUMMARY OF THE INVENTION
Embodiments described herein include methods for controlling and automating household appliances via a camera or other imaging device that is coupled to the appliance. Objects in the environment, such as household objects commonly found in household environments, which include food and drink containers, dishes, utensils, clothing, and the like, can be placed in the field of view of the camera or other imaging-device. Indicia on the objects can be recognized and associated with one or more instructions, commands, or actions to be performed by the household appliance.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features of the invention will now be described with reference to the drawings summarized below. These drawings (not to scale) and the associated descriptions are provided to illustrate preferred embodiments of the invention and are not intended to limit the scope of the invention.
FIG. 1 is a flowchart that generally illustrates a process useful for controlling a household appliance through the use of visual inputs.
FIG. 2 illustrates household appliances and associated actions, instructions to perform household duties.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Although this method will be described in terms of certain preferred embodiments, other embodiments that are apparent to those of ordinary skill in the art, including embodiments that do not provide all of the benefits and features set forth herein, are also within the scope of the method.
Embodiments of the method include methods for controlling and automating household appliances via a camera or other imaging device that is coupled to the appliance. Advantageously, objects in the environment, such objects commonly found in households, can be placed within the field of view of the camera, a visual sensor or other imaging device. Indicia on the objects can be recognized and associated with one or more instructions, commands, or actions to be performed by the appliance.
Examples of embodiments will now be described. Although embodiments of the method will be described in the context of selected appliances, it will be understood by one of ordinary skill in the art that the principles and advantages described herein will also be applicable to a broad variety of appliances. Example household appliances and associated actions and instructions are shown in FIG. 2 . For example, a household appliance 202 can correspond to one of a microwave oven, a conventional oven, a stove, a washing machine, a clothes dryer, a dishwasher, a refuse container, a refrigerator, and an iron. It will be understood that the term “appliance” does not include automated machines typically found in an office, retail, or industrial environment, such as a copy machine, a mail sorting machine, and a hand-held barcode scanner, and does not include audiovisual entertainment devices such as a VCR, a television, a radio, and a DVD player. One or more example instructions or operational parameters 204 are associated with each appliance 202 through a visually-based automation process. It will be understood that the instructions associated with each appliance depend on the nature and the model of the appliance, and the operational parameters associated with a particular appliance may contain parameters that are not shown in FIG. 2 . Additionally, it will be understood that when more than one operational parameter is associated with an appliance, an embodiment that addresses some, but not all, of the operational parameters is still within the scope of the method contemplated herein.
The appliances described may include single-processor or multiprocessor embedded systems. Additionally, these appliances include an addressable storage medium or computer accessible medium, such as random access memory (RAM), an electronically erasable programmable read-only memory (EEPROM), flash memory, hard disks, floppy disks, laser disk players, digital video devices, Compact Disc ROMs, DVD-ROMs, video tapes, audio tapes, magnetic recording tracks, electronic networks, and other techniques to transmit or store electronic content such as, by way of example, programs and data. In one embodiment, the appliances are equipped with a network communication device such as a network interface card, a modem, infra-red (IR) port, or other network connection device suitable for connecting to a network. Furthermore, the appliances may execute an appropriate operating system such as Linux, Unix, VxWorks®, QNX® Neutrino®, Microsoft® Windows®3.1, Microsoft® Windows®95, Microsoft® Windows®98, Microsoft® Windows® NT, Microsoft® Windows®2000, Microsoft® Windows® Me, Microsoft® Windows®, XP, Apple® MacOS®, IBM® OS/2®, Microsoft® Windows® CE, or Palm OS®. In another embodiment, the method is implemented in a dedicated controller or processor, where no operating system is used. As is conventional, the appropriate operating system may advantageously include a communications protocol implementation, which handles incoming and outgoing message traffic passed over the network. In other embodiments, while the operating system may differ depending on the type of appliance, the operating system may continue to provide the appropriate communications protocols necessary to establish communication links with the network.
In one embodiment, the user can train or program the appliance's recognition system on sets of indicia that correspond to previously identified household objects and associate an object with appropriate operating instructions such that when the object is presented to the appliance's imager at a later time, the appliance can recognize the object and retrieve and/or perform the associated operating instructions. The selection of the sets of indicia that correspond to selected objects in the recognition in training or programming a recognition system can be accomplished, for example, through selecting and storing one or more visual measurement representation, such as features corresponding shape, color, size and graphical representation of common household objects. Alternatively, a fair representation of the pixel information associated with object images can be stored in a recognition database for training purpose. The training information can be used by the appliances later to match with visual images received to initiate a series of actions automatically. FIG. 2 shows exemplary natures of instructions 204 of household appliances associated with the corresponding household appliances 202 .
The visual sensor can correspond to a digital camera with a CCD imager, a CMOS imager, an infrared imager, and the like. The visual sensor can include normal lenses or special lenses, such as wide-angle lenses, fish-eye lenses, omni-directional lenses, and the like. Further, the lens can include reflective surfaces, such as planar, parabolic, or conical mirrors, which can be used to provide a relatively large field of view or multiple viewpoints. Another example of a visual sensor is an optical scanner, such as a bar-code scanner, that uses a laser to scan.
DETAILED DESCRIPTIONS OF DRAWINGS
FIG. 1 is a flowchart that generally illustrates a visually-based automated process for controlling and automating an appliance through the use of visual inputs. It will be appreciated by the skilled practitioner that the illustrated process can be modified in a variety of ways without departing from the spirit and scope of the method. For example, in another embodiment, various portions of the illustrated process can be combined, can be rearranged in an alternate sequence, can be removed, and the like.
At the start of the process, the appliance has already been trained or programmed to recognize previously identified household objects and associate operating instructions with the recognized objects.
The process begins in a state 102 . In the state 102 , the process receives or monitors visual data from a visual sensor, such as data from a camera. The visual sensor can also correspond to an optical scanner, such as a barcode scanner. Advantageously, such visual sensors are relatively inexpensive. The process advances from the state 102 to a state 104 .
In the state 104 , the process analyzes the visual data acquired in the state 102 for recognition of indicia. A variety of visual recognition techniques can be used, and it will be understood by one of ordinary skill in the art that an appropriate visual recognition technique can depend on a variety of factors, such as the visual sensor used and/or the visual indicia used. In one example, the indicia are identified using an object recognition process that can identify visual features. In one example, the visual features correspond to scale-invariant (SIFT) features. The concept of SIFT has been extensively described in the literature. See David G. Lowe, Object Recognition from Local Scale - Invariant Features , Proceedings of the International Conference on Computer Vision, Corfu, Greece (September 1999) and David G. Lowe, Local Feature View Clustering for 3 D Object Recognition , Proceedings of the IEEE Conference on Computer Vision and Pattern Recognition, Kauai, Hawaii (December 2001). In another example, the indicia are identified by reading a printed code, such as a bar code or a colored bar code. In yet another example, the indicia are identified by recognizing a color or a range of colors.
The identified indicia are compared to indicia stored in a database that are recognized by the system. In one embodiment, the database that contains indicia that can be recognized is contained within the system. In another embodiment, the database that contains indicia that can be recognized is not contained within the system and can instead be accessed remotely, over a network such as the Internet. The process may find one match, may find multiple matches, or may find no matches. Optionally, if the process finds multiple matches, it can, based on one or measures of the quality of the matches, designate one match, such as the match with the highest value of an associated quality measure, as the best match.
It will be understood that such a process can be embodied in a dedicated hardware circuit. Other appropriate techniques will be readily determined by one of ordinary skill in the art. The process advances from the state 104 to a decision block 106 .
In the decision block 106 , a determination is made as to whether the process found one or more matches in the state 104 . If the process does not identify any matches in the state 104 , the process returns to the state 102 to acquire another image. If the process identifies one or more matches in the state 104 , the process proceeds to a decision block 108 . The process finds a match when at least one feature in a received image match with at least one feature from a previously identified household object in the training or program phase of the appliance. The process, in a preferred embodiment, is a visually-based automated process. The criteria use in the decision block 106 can be a predetermined measurement for a measure of a quality. In one embodiment of this invention, the measurement can be associated with the number of matched features between the previously identified household object and the visual image received by the sensor. Two states can be set up for a measure of a quality for the measurement of quality. The first state can be associated with a higher match quality and the second state is associated a lower match quality. The measurement of quality is representative of a measure of a quality in either state. Additional quality metric can be used to represent the measurement of quality such as probability of identical match and the like.
In the decision block 108 , a determination is made as to whether the match found in the decision block 108 is considered reliable. In one embodiment, when one or more matches are found, the system can optionally wait for one or more extra cycles to compare the matched object from these extra cycles, so that the system can more reliably determine the true object. In one implementation, the system requires that the matched object be identical for two or more cycles. Another implementation computes the statistical probability that each object that can be recognized is present over several cycles. In another embodiment, a match is considered reliable if the value of the associated quality measure exceeds a predetermined threshold. In another embodiment, a match is considered reliable if the number of identified indicia exceeds a predetermined threshold. In yet another embodiment, the identified match, or the best match if multiple matches have been identified, is always considered reliable. The analysis process of using a quality matrix such as the number of cycles for identical results, statistical probability, value of the associated quality measure or multiple matches can include other parameters to set a proper threshold of acceptable actions for an appliance depending on the degree of reliability desired. A two-state measurement metric can be use to filter the lower quality match from higher quality match before the process automates the appliance to execute an operating instruction.
If the decision block 108 determines that the match is not considered reliable, the process returns to the state 102 to acquire another image. If the process determines that the match is considered reliable, the process proceeds to a state 110 .
In the state 110 , the system performs one or more actions that are associated with the matched object. The action or actions can vary in a wide range. For example, the actions can correspond to commencing the appliance's operation in a particular mode, altering the appliance's operation, initiating a communication such as an e-mail message, playing a recorded sound, displaying a prompt that includes graphics and/or text on a screen, enunciating one or words or phrases using machine-generated speech, and the like.
The process then returns to the state 102 to acquire another image. In one embodiment, the system returns to the state 102 immediately after it has initiated the action in the state 110 . In another embodiment, the system waits until the action initiated in the state 110 has been completed before returning to the state 102 . In yet another embodiment, the system waits a pre-determined amount of time before returning to the state 102 . Other appropriate modes of returning to the state 102 will be readily determined by one of ordinary skill in the art.
Example Modes of Operation
Example applications of the interaction method will now be described to further illustrate example system operations.
In one embodiment, the method can advantageously be used to simplify the operation of a microwave. For example, a user of a microwave can present a food container to an imaging system coupled to the microwave, and the microwave can recognize the container by identifying indicia present on the surface of the container. The microwave can then retrieve operating instructions, such as, for example, cook time and cook power, associated with the identified container. The microwave can display or enunciate the retrieved operating instructions to the user and can program itself with the retrieved operating instructions. The database that associates the recognized container with the operating instructions can be, by way of example, stored within the microwave or stored on a network, such as the Internet, and accessed by the microwave as necessary. Optionally, the user can train the microwave's recognition system on selected food containers and associate a food container with appropriate operating instructions such that when the food container is presented to the microwave's imager again, the microwave will recognize the food container and retrieve the associated operating instructions.
In another embodiment, the method can advantageously be used in a refuse container to sort refuse efficiently. For example, a user of the refuse container can present a piece of refuse to an imaging system coupled to the container, and the container can recognize the refuse by identifying indicia present on the surface of the refuse. The refuse container can then retrieve disposal instructions, such as, for example, an indication that the refuse should be recycled rather than discarded as trash. The refuse container can display or enunciate the disposal instructions to the user. The database that associates the recognized refuse with the disposal instructions can be, by way of example, stored within the refuse container or stored on a network, such as the Internet, and accessed by the refuse container as necessary. Optionally, the user can train the refuse container's recognition system on selected refuse objects and associate a refuse object with appropriate disposal instructions such that when the refuse object is presented to the refuse container's imager again, the refuse container will recognize the refuse object and retrieve the associated disposal instructions.
In another embodiment, the method can advantageously be used to clean dishes, such as, for example, utensils, plates, drinking vessels, and the like, efficiently and safely. For example, a user of a dishwasher can present a dish to an imaging system coupled to the dishwasher, and the dishwasher can recognize the dish by identifying indicia present on the surface of the dish. The dishwasher can then retrieve cleaning instructions, such as, for example, an indication that the dish is not dishwasher-safe and should not be cleaned in the dishwasher. The dishwasher can display or enunciate the cleaning instructions to the user. The database that associates the recognized dish with the cleaning instructions can be, by way of example, stored within the dishwasher or stored on a network, such as the Internet, and accessed by the dishwasher as necessary. Optionally, the user can train the dishwasher's recognition system on selected dishes and associate a dish with appropriate cleaning instructions such that when the dish is presented to the dishwasher's imager again, the dishwasher will recognize the dish and retrieve the associated cleaning instructions.
In another embodiment, the method can advantageously be used to wash clothing efficiently and safely. For example, a user of a washing machine can present an article of clothing to an imaging system coupled to the washing machine, and the washing machine can recognize the article by identifying indicia present on the surface of the article or on a label attached to the article. The washing machine can then retrieve washing instructions, such as, for example, an indication that the article of clothing should be washed in cold water or an indication that the article of clothing should be washed only with articles of clothing of similar color. The washing machine can display or enunciate the washing instructions to the user. In another implementation, the washing machine can identify multiple sets of indicia, corresponding to multiple articles of clothing, in the same image and can retrieve washing instructions corresponding to the identified plurality of articles of clothing. By way of example, if the washing machine were to recognize the presence of a red article of clothing and a white article of clothing in the same image, the washing machine can act to enunciate a warning that should it be desired to wash the two identified articles of clothing together, the water temperature should be set to cold water, or the washing machine can automatically set the water temperature to a cold water setting. The database that associates the recognized article or articles of clothing with the washing instructions can be, by way of example, stored within the washing machine or stored on a network, such as the Internet, and accessed by the washing machine as necessary. Optionally, the user can train the washing machine's recognition system on selected articles of clothing and associate an article of clothing and/or combinations of articles of clothing with appropriate washing instructions, such that when the article or articles of clothing are presented to the washing machine's imager again, the washing machine will recognize the article or articles of clothing and retrieve the associated washing instructions.
In yet another embodiment, the invention enhance functionality of a refrigerator through the vision sensor and the method provide herein to inventory what remains in the refrigerator. The inventory can be advantageously displayed on a panel or screen in front of the refrigerator. The information on the screen can advise the household appliance owner of what is missing from the refrigerator. Furthermore, an owner of the automated refrigerator can generate a list of items from the display for shopping. In one preferred embodiment, the list so generated can be automatically sent for a refill order through a website for online grocery shopping for a refill order.
Thus, as described above, embodiments of the method enable users to interact with household appliances by employing familiar modes of interaction, such as visual interaction. Various embodiments of the method have been described above. Although this method has been described with reference to these specific embodiments, the descriptions are intended to be illustrative of the method and are not intended to be limiting. Various modifications and applications may occur to those skilled in the art without departing from the true spirit and scope of the method. | The invention is generally related to the systems and methods through which household appliances can provide intuitive and enhanced interactivity through visual inputs. In particular, the disclosure presents methods relating to control of a household appliance, such as a microwave or a refrigerator, via recognition of visual indicia, such as graphics, text, and the like, using a visual sensor such as a camera. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation application of U.S. patent application Ser. No. 11/955,074, entitled “Desalination Using Low-Grade Thermal Energy”, to Nagamany Nirmalakhandan et al, filed on Dec. 12, 2007, which claims priority to and the benefit of U.S. Provisional Application Ser. No. 60/950,076, entitled “Desalination using Low-Grade Thermal Energy”, to Nagamany Nirmalakhandan et al., filed on Jul. 16, 2007, and the specifications and claims thereof are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention (Technical Field)
[0003] The present invention relates to an apparatus and method for desalination.
[0004] 2. Description of Related Art
[0005] Interest in the use of low grade heat sources and recovery of waste heat is growing due to increasing energy costs and declining energy sources. Examples of low grade energy sources include solar energy and heat rejected by fossil fuel-based power plants, air conditioning/refrigeration systems, and industrial processes. As a consequence of the laws of thermodynamics, thermal systems have to reject large quantities of low grade heat energy to the environment. For example, heat rejection rate of modern combined cycle power plants is almost equal to their output. Approaches to utilize waste heat to produce value added products or services can conserve limited energy sources, reduce adverse environmental impacts, and minimize overall costs.
[0006] The present invention utilizes low grade heat to operate a new desalination process. Traditional desalination processes such as reverse osmosis, electrodialysis, mechanical vapor compression, and multi-effect flash distillation require electrical energy derived from nonrenewable sources, the cost of which has increased by 10 times over the past 20 years. Recently, a new desalination process has been proposed that has the potential to run solely on low grade heat sources at around 50° C. The present invention is a modification to that process, whereby it can run around the clock, using a thermal energy storage (TES) system that enables waste heat sources and renewable energy sources to be used to drive the process with minimum reliance on grid power. TES manages variable energy demand over time, is a continuous heat source, and has a lower specific energy for desalination. The present invention, unlike the process mentioned above, enables solar collectors and photovoltaic panels to provide the energy to drive the process. The TES system can be maintained at the desired temperature using low grade waste heat from any available source.
BRIEF SUMMARY OF THE INVENTION
[0007] A preferred embodiment of the present invention is described below. The embodiment is a desalination system comprising a desalination unit, a low grade heat source for powering the desalination unit and a thermal energy storage system for storing the low grade heat source and maintaining a specified temperature range. The system is able to run continuously within a specified temperature range between approximately 40-50° C. The low-grade heat source is at least partially supplied by an absorption refrigeration unit which maintains the thermal energy storage refrigeration unit at a specified temperature range. The absorption refrigeration unit operates at a pressure range of between approximately 1.4 to 15.75 kPa.
[0008] The desalination unit comprises an evaporation chamber, a condenser, a heat exchanger and one or more columns. The columns comprise a saline water column, a brine withdrawal column and a desalinated water column. The heat input to the evaporation chamber is provided by the thermal energy storage system.
[0009] The desalination system does not have a pump except for an initial starting pump. In addition, the system does not have any other moving parts.
[0010] Another embodiment of the present invention is a method of desalinating comprising the steps of operating a desalination unit, powering the desalination unit using a low grade heat source, storing the low grade heat source in a thermal energy storage unit and maintaining a specified temperature range of the low grade heat source. The desalination unit can run continuously and comprises desalinating saline water at a temperature range of approximately 40-50° C. The method can also comprise supplying the low grade heat source at least partially by an absorption refrigeration unit. The absorption refrigeration unit can also provide a cooling load. The thermal energy storage unit is maintained at a specified temperature range within the absorption refrigeration unit. Finally, the absorption refrigeration unit operates at a pressure range of between approximately 1.4 to 15.75 kPa.
[0011] Further scope of applicability of the present invention will be set forth in part in the detailed description to follow, taken in conjunction with the accompanying drawings, and in part will become apparent to those skilled in the art upon examination of the following, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0012] The accompanying drawings, which are incorporated into and form a part of the specification, illustrate one or more embodiments of the present invention and, together with the description, serve to explain the principles of the invention. The drawings are only for the purpose of illustrating one or more preferred embodiments of the invention and are not to be construed as limiting the invention. In the drawings:
[0013] FIG. 1 is a schematic of a preferred embodiment of the desalination system of the present invention;
[0014] FIG. 2 is a table of model parameters used in an example simulation of mass and energy balances of a preferred embodiment;
[0015] FIG. 3 is a chart showing heat transfers and efficiency for the desalination system of the present invention over 24 hours;
[0016] FIG. 4 is a chart showing variations of desalinated water temperature and saline water temperature with respect to ambient temperature over 24 hours for the desalination system of the present invention;
[0017] FIG. 5 is a comparison of parameters in a typical absorption refrigeration system and in the preferred embodiment;
[0018] FIG. 6 is a chart showing ambient temperature versus thermal energy storage temperature over 24 hours for a typical thermal energy storage and in the preferred embodiment;
[0019] FIG. 7 is a comparison of the preferred embodiment with a multi-stage flash distillation process;
[0020] FIG. 8 is a chart showing solar fraction and optimum solar panel area for a typical absorption refrigeration system and in the preferred embodiment;
[0021] FIG. 9 is a chart showing desalination rates for different cooling loads and solar panel areas for a typical absorption refrigeration system and in the preferred embodiment;
[0022] FIG. 10 is a chart showing the effect of withdrawal rate on desalination efficiency and saline water temperature for the desalination system of the present invention;
[0023] FIG. 11 is a chart showing the effect of withdrawal rate on concentration and desalination efficiency for the desalination system of the present invention;
[0024] FIG. 12A is a chart showing solar panel area versus desalination rate at different withdrawals for the desalination system of the present invention; and
[0025] FIG. 12B is a chart showing cooling load versus desalination rate at different withdrawals for the desalination system of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0026] This invention concerns the feasibility of a new desalination process utilizing low grade thermal energy. The process operates at near-vacuum pressures created by passive means. This allows for the process to operate at low temperatures with higher efficiency. The process utilizes low grade thermal energy rejected by an absorption refrigeration system (ARS). The condenser of the ARS rejects low grade thermal energy at approximately 55° C. which is recovered and stored in a low temperature thermal energy storage (TES) tank. A thermal energy storage tank serves best to manage energy demands of the desalination process by maintaining the source temperature at approximately 50-70° C. as the energy demand to the desalination system is dependent on the ambient temperature.
[0027] Results of this feasibility study show that the thermal energy rejected by an ARS of cooling capacity of approximately 3.25 kW (0.975 tons of refrigeration) along with an additional energy input of approximately 208 kJ/kg of desalinated water is adequate to produce desalinated water at an average rate of approximately 4.5 kg/hr. Energy demand for this process is competitive with well-established Multi Stage Flash distillation processes. An integrated process model and performance curves of the proposed approach are presented below. The effect of process parameters, such as withdrawal rate, are also presented below.
[0028] The preferred embodiment of the desalination system of the present invention is shown schematically in FIG. 1 . The invention comprises desalination unit 10 , absorption refrigeration system 12 , and thermal energy storage 14 . Desalination unit 10 comprises evaporation chamber 16 , condenser 18 , one or more heat exchangers 20 , 22 , and columns 24 , 26 and 28 (e.g. between approximately 10-11 m tall, equivalent to the local barometric head). These three columns are saline water column 24 , brine withdrawal column 26 , and desalinated water column 28 , each with its own constant-level holding tank, saline water tank 30 , brine tank 32 , and desalinated water tank 34 , respectively. The heat input to evaporation chamber 16 is provided by thermal energy storage 14 , which is maintained at a particular temperature or range (e.g. between approximately 50-70° C.) by absorption refrigeration system 12 , preferably powered by solar energy.
[0029] Holding tanks, saline water tank 30 , brine tank 32 , and desalinated water tank 34 are installed at ground level while, evaporation chamber 16 is installed atop three columns 24 , 26 , 28 at a barometric height (e.g. between approximately 10-11 m, equivalent to the local barometric head) above the free surface in holding tanks 30 , 32 , 34 to create a natural vacuum in the headspaces of three columns 24 , 26 , 28 . This configuration enables the desalination process to proceed preferably without any mechanical pumping. There are also preferably no other moving parts needed, except for the pump used to start the system. The temperature of the head space of the feed water column is maintained slightly higher, approximately 45-65° C. than that of the desalinated water column, approximately 15-35° C. Since the head spaces are at near-vacuum level pressures, a temperature differential (e.g. between approximately 10-25° C.) is adequate to evaporate water from the feed water side and condense in the desalinated water side. In this manner, saline water can be desalinated at between approximately 40-50° C., which is in contrast to the 60-100° C. range in traditional solar stills and other distillation processes. Brine is withdrawn continuously from evaporation chamber 16 flowing through tube-in-tube heat exchanger 20 preheating the saline water feed entering evaporation chamber 16 .
[0030] Absorption refrigeration system 12 operates with a refrigerant (e.g. LiBr—H 2 O) in a pressure range of preferably 1 to 16 kPa. Heat energy required by generator 38 of absorption refrigeration system 12 is preferably supplied by solar collector 36 (e.g. flat panel) during sunlight hours and by auxiliary electric or gas heater 40 during non-sunlight hours. Solar collector 36 maintains generator 38 at a specified temperature or range (e.g. between approximately 80-110° C.). Heat rejected by condenser 42 of absorption refrigeration system 12 maintains thermal energy storage 14 at a specified temperature or range (e.g. between approximately 50-70° C.) to serve as the low grade heat source for the desalination process. Evaporator 44 of absorption refrigeration system 12 feeds the cooling load. Thus, the preferred embodiment of the present invention performs two functions of continuous desalination and cooling with minimal amounts of external nonrenewable energy input.
Mass and Energy Balances
[0031] The preferred embodiment was developed based on mass and energy balances. Thermodynamic analysis of the preferred embodiment was performed through computer simulations using Extend®, manufactured by ImagineThat Inc., San Jose, Calif. and EES®, manufactured by F-Chart Software, Madison, Wis. simulation software.
Desalination System
[0032] An evaporator area of 5 m 2 and a height of 0.25 m were considered. In all calculations, the reference temperature was assumed to be 25° C. All heat exchangers were assumed to have 80% efficiency. The following mass and heat balance equations apply to the different components:
[0033] Mass balance on water in the evaporation chamber:
[0000]
t
(
ρ
V
)
=
ρ
i
V
.
i
-
ρ
w
V
.
w
-
ρ
e
V
.
e
(
1
)
[0034] Mass balance on solute in the evaporation chamber:
[0000]
t
(
ρ
CV
)
s
=
ρ
i
C
i
V
.
i
-
ρ
w
C
w
V
.
w
(
2
)
[0035] Heat balance for the evaporation chamber:
[0000]
t
(
ρ
c
p
VT
)
s
=
Q
In
+
(
ρ
c
p
T
)
i
V
.
i
-
(
ρ
c
p
T
)
w
V
.
w
-
Q
E
-
Q
L
(
3
)
[0036] Evaporation rate is expressed by (Bemporad, 1995):
[0000]
q
e
=
α
m
A
ρ
f
[
f
(
C
s
)
p
(
T
s
)
(
T
s
+
273
)
1
/
2
-
p
(
T
f
)
(
T
f
+
273
)
1
/
2
]
(
4
)
[0000] where, p(T)=e (63.042−7139.6/(T+273)−6.2558 ln(T+273)) *10 2 Pa
[0037] In the above equations, subscripts e, i, and w, represent evaporator outlet, inlet, and withdrawal conditions, respectively; f and s represent freshwater and saline water respectively. The variables are defined as follows:
V=volume of water in the evaporation chamber [m 3 ] {dot over (V)}=volumetric flow rate [m 3 /hr] ρ=density [kg/m 3 ] c p =specific heat capacity of saline water [kJ/kg-°C.] C=solute concentration [%] T s =saline water temperature in the evaporator chamber [°C.] T=temperature [°C.] q e =evaporation rate [m 3 /s] A=area of the evaporation chamber [m 2 ] α m =an experimental coefficient [10 −7 -10 −6 kg/m 2 -Pa-s-K 0.5 ] (11) f(C)=correlation factor for the presence of solute concentration [%] Q In =energy input from thermal energy storage [kJ/hr] Q L =energy losses from evaporation chamber [kJ/hr] Q E =energy used for evaporation [kJ/hr]
[0052] Energy used for evaporation is given by:
[0000] Q E =3,600ρ f h L ( T S ) q e (5)
[0000] where, h L (T) is the latent heat of evaporation [kJ/kg] given by:
[0000] h L ( T )=[(3146−2.36( T+ 273° K)]
[0053] The desalination efficiency, η d , is defined as:
[0000]
η
d
=
m
e
h
L
∑
Q
In
Δ
t
(
6
)
[0000] where,
m e =mass of desalinated water produced over a period of time [kg] h L =latent heat of evaporation at saline water temperature [kJ/kg] ΣQ In Δt=energy provided by the thermal energy storage over a period of time [kJ]
[0057] Expressions for density, enthalpy and pressure variations are presented below.
[0058] Density variation with temperature and concentration is given as:
[0000] ρ( T,C )=ρ 0 (1−β T ΔT 0 +β C ΔC 0 )
where, ΔT 0 and ΔC 0 are variations from reference property values, of density. β T =5.10-4 C-1, thermal expansion coefficient β C =8.10-3%-1, solutal expansion coefficient
[0062] Effect of concentration on specific heat is given as:
[0000] c P ( C )=α 2 C+β 2
where, α 2 =−30.10 J kg-1 0C-1
β 2 =4178.4 J kg-1 0C-1
[0065] Evaporation energy is given as:
[0000] Q e =ρ f h fg ( T S ) q e [kJ/hr]
[0066] Latent heat of evaporation is given as:
[0000] h fg ( T )=10 3 *[(3146−2.36( T+ 273° K)] J/kg
[0067] The average heat transfer from the tips of the fins is given by (Rohsenow 1985):
[0000] Nu s =cRa s b where Nu=Nusselt number, Ra=Rayleigh Number and b and c are constants
b=0.29; c=0.44+0.12ε; ε=Dco/Dfin
[0070] This equation is valid for 2<Ras<104 and 1.36<1/ε<3.73
[0071] Rayleigh number is given as (Incropera, 2002):
[0000]
R
a
s
=
g
β
(
T
co
-
T
a
)
S
3
α
γ
S
D
fin
β
=
1
273
+
T
a
where g=local acceleration due to gravity (m/sec 2 )
β=temperature coefficient, 1/° K α=thermal diffusivity, m 2 /s γ=kinematic viscosity, m 2 /s T a and T co =temperatures of the ambient and condenser respectively, ° K S=distance between the successive fins, m
[0078] Condenser Calculations: Average heat transfer through the cylinder surfaces and fins is given by:
[0000]
Nu
s
=
Ra
s
12
π
{
2
-
exp
[
-
(
c
1
Ra
s
)
3
/
4
]
-
exp
[
-
β
(
c
1
Ra
s
)
3
/
4
]
}
where
1.67
<
1
/
ξ
<
∞
β
=
0.17
ξ
+
exp
(
-
4.8
ξ
)
c
1
=
[
23.7
-
1.1
(
1
+
1.52
ξ
2
)
1
/
2
+
β
]
4
/
3
[0079] The rate of heat transferred from the condenser prime surface and fins can be calculated as:
[0000] Q c =[h co,tip NA f,tip η f +h co NA f,sides η f +h co A b ]( T co −T a )
where h co,tip , h co =heat transfer through the tips and base or sides
N=number of fins A b , A f,sides , and A f,tip =areas of base, fin sides and tip respectively η f =efficiency of fins
[0084] For turbulent free convection for Ra>109,
[0000] Nu=c ( Ra ) 0.333 where c=0.10
[0086] For f in efficiency (Donald Q. Kern, 1972):
[0000] φ=( ro−ri )3/2(2 h/kAp )1/2
[0000] ρ=( ri/ro )
where r i and r o =inner and outer radius of fins respectively, m
h=heat transfer coefficient trough the fin, w/m 2 -° K k=heat transfer coefficient trough the surface, w/m-° K A p =Area of the fins η=(φ, ρ)
Absorption Refrigeration System
[0092] Absorption refrigeration system 12 is preferably driven by solar energy during sunlight hours and by auxiliary electric or gas heater 40 during non-sunlight hours, although any type of power may be utilized. The efficiency of solar collectors is expressed in terms of solar fraction, which is the contribution of solar energy to the total load in terms of the fractional reduction in the amount of extra energy that must be supplied. A storage tank volume of approximately 0.125 m 3 /m 2 was considered and the optimum area of solar collectors required was found from a solar fraction graph. The optimum number of collectors was the lowest number of collectors for which a 100% solar fraction was achieved at the hour maximum solar radiation. Additional energy for heating and pumping was required for condenser 42 of absorption refrigeration system 12 to dissipate heat at approximately 55° C. The pumping requirements were calculated using EES® software.
[0093] Heat balance across solar collection system:
[0000]
(
m
S
C
ps
T
S
1
)
t
=
[
F
R
A
p
{
(
τ
α
)
I
S
-
U
L
(
T
gs
-
T
a
)
}
-
U
S
A
S
(
T
S
1
-
T
a
)
-
m
R
C
pr
(
T
S
1
-
T
gs
)
]
(
7
)
where, m s =mass of water in storage tank [kg]
C ps =specific heat of water in storage tank [kJ/kg-° C.] T S1 =temperature of water in storage tank [° C.] F R =heat removal factor [dimensionless] A p =area of solar panels [m 2 ] τ=transmitivity of glass [dimensionless] α=absorptivity of water [dimensionless] I S =solar energy [kJ/hr-m 2 ] U L =heat loss coefficient [kJ/hr-m 2 -° C.] T gs =temperature of the water from the generator [° C.] T a =ambient temperature [° C.] U S =heat losses from the surface of storage tank [kJ/hr-m 2 -° C.] A S =surface area of storage tank [m 2 ] m R =flow rate of recycling water [kg/hr] C pr =specific heat of recycling water [kJ/kg-° C.]
Thermal Energy Storage:
[0109] Sensible heat thermal energy storage 14 stores heat rejected by the absorption refrigeration system-condenser 42 . The optimal volume of thermal energy storage 14 to maintain evaporation chamber 16 at the desired temperature differential was determined by solving the heat balance for thermal energy storage 14 by trial and error.
[0110] Heat balance for thermal energy storage 14 :
[0000]
t
(
ρ
C
p
v
T
)
TES
=
Q
R
-
Q
In
-
Q
L
1
(
8
)
where, Q R =heat rejected by condenser in the absorption refrigeration system [kJ/hr]
Q L1 =energy losses from the thermal energy storage surface [kJ/hr] C p =specific heat of the water in the TES [kJ/kg-° C.] v=volume of the thermal energy storage [m 3 ]
Results:
[0115] The model equations were solved using the fixed parameters listed in FIG. 2 and for a particular site. Previous studies have shown that the effect of water depth in evaporation chamber 16 did not have any significant effect on the evaporation rate. This is in contrast to the traditional solar stills, where the water volume provided energy storage that is required for continued evaporation during non-sunlight hours. Since the preferred embodiment does not depend on solar energy for continuous operation, the effect of water depth was not taken into account.
[0116] First, results of an example case where the model equations were solved for the reference parameters listed in FIG. 2 are presented. In this example case, the withdrawal rate was fixed at approximately 2.5 kg/hr (≈50%). These results demonstrate the effectiveness of the preferred embodiment. Then, the total energy consumption of the preferred embodiment was analyzed and compared to that of a multi-stage flash distillation process. Finally, the effect of withdrawal rate on the design and performance of the preferred embodiment is presented.
Heat Balance for Evaporation Chamber
[0117] The heat balance for evaporation chamber 16 is described by Equation 3. FIG. 3 shows the variations in heat provided by thermal energy storage 14 , the heat consumed for evaporation, and the heat lost over a 24-hr period for a summer day, when the ambient temperature ranged from between approximately 25 to 37° C. The desalination efficiency defined by Equation 6 is also indicated in FIG. 3 by the bold line. As expected, the heat lost by evaporation chamber 16 was higher during non-sunlight hours than that during sunlight hours due to lower ambient temperatures during non-sunlight hours. Under the example conditions, the energy available for desalination was about 12,500 kJ/hr (=3.45 kW) which was the waste heat rejected by condenser 42 in absorption refrigeration system 12 . However, the net heat transfer was dependent on the temperature gradient between the transfer medium and the heat source. The actual mass of water that could be evaporated in evaporation chamber 16 and hence, the desalination efficiency, depended on the heat input from thermal energy storage 14 , the ambient temperature at which the condensation took place, and the brine withdrawal rate. Since the driving force for evaporation is the temperature differential, between evaporation chamber 16 and condenser 42 , the heat input to evaporation chamber 16 during the day is lower than that input during the night. During the night, both the ambient temperature and the freshwater temperature are low, favoring a higher desalination rate, thus resulting in higher heat input and vice versa.
[0118] The temperature variations in the saline water in evaporation chamber 16 and the desalinated water with respect to ambient temperature over a 24-hr period are shown in FIG. 4 . The temperature of saline water varied from between approximately 43.5 to 46° C. and the ambient temperature ranged from between approximately 25 to 37° C. while the fresh water temperatures ranged from between approximately 35 to 40° C. FIG. 4 shows that thermal energy storage 14 was able to maintain the approximately 10° C. temperature differential between the saline water side and the desalinated water side. It is noted that the ambient temperature is an important variable because condensation occurs at the ambient temperature, which indirectly determines the desalination rate in this process.
Operating Conditions of Absorption Refrigeration System
[0119] Absorption refrigeration system 12 is designed for two functions: for maintaining thermal energy storage 14 at the desired temperature and for providing the cooling load. As such, absorption refrigeration system 12 operates under slightly different conditions compared to the traditional systems used for cooling alone. Operating conditions for a typical absorption refrigeration system used in cooling and the conditions for absorption refrigeration system 12 are compared in FIG. 5 , for the same cooling load of approximately 3.25 kW. The notable difference is the pressure ranges between approximately 1 and 6.3 kPa versus about 1.4 to 15.75 kPa respectively.
[0120] Volume of thermal energy storage
[0121] Winter conditions were assumed to determine the volume of thermal energy storage 14 necessary to provide the heat energy to evaporation chamber 16 . Solving Equation 8 by trial and error so that the temperatures at the beginning and the end of a 24-hr period would be within approximately ±0.01° C., the volume of thermal energy storage 14 was found to be approximately 10 m 3 . The heat demand by evaporation chamber 16 on thermal energy storage 14 varied from between approximately 8,700 and 14,200 kJ/hr over a 24-hour period shown in FIG. 2 ; yet, as shown in FIG. 6 , thermal energy storage 14 volume of approximately 10 m 3 was found to be adequate to maintain its temperature at approximately 50° C. throughout the same period to provide the energy needs of evaporation chamber 16 .
Energy Requirements
[0122] An embodiment of the invention may require additional non-renewable energy for the following: auxiliary heat energy for generator 38 (=approximately 192 kJ/kg of desalinated water) plus mechanical energy to circulate heat transfer medium between thermal energy storage 14 and evaporation chamber 16 (=approximately 14 kJ/kg of desalinated water); to circulate the heat transfer medium between thermal energy storage 14 and condenser 18 (=approximately 2 kJ/kg of desalinated water); and to pump the refrigerant in absorption refrigeration system 12 (=approximately 0.04 kJ/kg of desalinated water). Hence, the total additional energy required to maintain thermal energy storage 14 at the desired conditions is approximately 208 kJ/kg of desalinated water produced. In comparison, multi-stage flash distillation process would require a heat energy of approximately 294 kJ/kg of desalinated water plus a mechanical energy of approximately 44 kJ/kg of desalinated water, for a total of approximately 338 kJ/kg of desalinated water. Thus, the present invention requires about 60% of the energy required by the multi-stage flash distillation process. A comparison between the two processes is summarized in FIG. 7 .
Solar Collector for Absorption Refrigeration System
[0123] Solar collector 36 , augmented by auxiliary electric heater 40 , is sized to provide for thermal energy storage 14 and the cooling load. The temperature of storage tank 46 of solar collector 36 is set to a particular temperature or range (e.g. between approximately 110-115° C.) in order to maintain generator 38 temperature at a particular temperature or range (e.g. between approximately 100-110° C.). The energy to be provided by auxiliary heater 40 is equal to the difference between the energy required by generator 38 and that can be collected from solar isolation. FIG. 8 illustrates this difference and the solar fraction, over a 24-hr period. The optimal area of the collectors can be found from Equation 7. For the conditions described herein, solar collector area of approximately 25 m 2 can satisfy a cooling load of approximately 3.25 kW, at an average desalination rate of approximately 4.3 kg/hr. The relationships between desalination rate, solar panel area, and cooling load are presented in FIG. 9 .
[0000] Brine Withdrawal vs. System Performance
[0124] Brine withdrawal rate is the primary control variable in this system, which has positive as well as negative impacts on the performance of the system. At low withdrawal rates, salts build up in evaporation chamber 16 , and evaporation rates decrease as shown by Equation 4. High salt levels also reduce the enthalpy of saline water that can further reduce evaporation. For example, when salinity increases by approximately 1%, evaporation is also reduced by about the same percentage. Even though better salt removal can be achieved with higher withdrawal rates, large amounts of sensible heat are also removed from evaporation chamber 16 , resulting in decline of evaporation chamber 16 temperature. Simulation results presented in FIG. 10 show the decline in evaporation chamber 16 temperature and in desalination efficiency with increasing withdrawal rate. For example, the desalination efficiency dropped from between approximately 90.5% and 80% when the withdrawal rate increased from between approximately 2.5 kg/hr and 25 kg/hr. FIG. 11 shows the salt buildup with time and the resulting decline in desalination rate. Similar observations have been reported previously.
[0125] Further simulations were conducted to evaluate the effect of withdrawal rate on desalination rate, cooling load, solar collector area, and auxiliary heat requirement. As shown in FIG. 12 , cooling load and solar panel area are not sensitive to withdrawal rate in the range of between approximately 50-200%. For a given desalination rate, even though the cooling load at a withdrawal rate of approximately 200% is higher than that at approximately 100%, the auxiliary heat addition is also higher. In addition, the solar collector area is also higher. As discussed before, the desalination efficiency also decreases. Based on these results, a withdrawal rate of approximately 100% is an acceptable rate to minimize salt buildup and maintain system performance.
[0126] In summary, model simulations show that the preferred embodiment can achieve a desalination efficiency of at least approximately 85% and higher (e.g. approximately 85-90%) at a brine withdrawal rate of approximately 70-100% with an energy consumption of less than approximately 250 kJ/kg (e.g. between approximately 150-300 kJ/kg) of freshwater from seawater. The energy requirements for the preferred embodiment are less than that are required for a multi-stage flash distillation process. Based on the results from the example, an approximate 100% withdrawal rate could prevent scale formation that could reduce the evaporation rate. A typical unit with a thermal energy storage volume, the volume calculated by solving a heat balance using trial and error (e.g. between approximately 10-20 m 3 ), can produce fresh water at between approximately 4.5 kg/hr and provide a cooling load of between approximately 3.25 kW with a solar panel area of between approximately 25 m 2 . The preferred embodiment minimizes non-renewable energy usage and may be improved further by incorporating a double or triple-effect configuration.
[0127] Although the invention has been described in detail with particular reference to these preferred embodiments, other embodiments can achieve the same results. Variations and modifications of the present invention will be obvious to those skilled in the art and it is intended to cover in the appended claims all such modifications and equivalents. An example of a configuration that has been demonstrated by a prototype is described in Example 1. The entire disclosures of all references, applications, patents, and publications cited above are hereby incorporated by reference.
EXAMPLE 1
[0128] A prototype unit was constructed and experiments were conducted using direct solar energy and photovoltaic energy as heat sources. Desalination was performed on a continuous basis over 24 hours a day for several months. This prototype comprised of columns that were 10 m, equivalent to the local barometric head. The temperature of the head space of the feed water column was maintained at approximately 40-50° C., while the desalinated water column was maintained at approximately 35-45° C. The pressure in the evaporation chamber remained at approximately 0.085 atm. The specific energy required by this prototype was approximately 3,370 kJ/kg of desalinated. This system was run entirely on solar energy with direct solar heat during sunlight hours and with a 350-W DC heater powered by batteries that were charged by the photovoltaic panels during the day time. This example system was able to recover potable quality water meeting United States Environmental Protection Agency drinking water standards from the effluent of a municipal wastewater treatment plant. | This invention describes a low temperature, self-sustainable desalination process operated under natural vacuum conditions created and maintained by barometric pressure head. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. Ser. No. 11/833,266 filed Aug. 3, 2007, which claims priority to Great Britain Application No. 0615620.2 filed Aug. 5, 2006, each of which is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] This invention relates to processes for the production of optically active 2-(disubstituted aryl)cyclopropylamine derivatives and optically active 2-(disubstituted aryl)cyclopropane carboxamide derivative which are useful intermediates for the preparation of pharmaceutical agents, and in particular the compound [1S-(1α,2α,3β(1S*,2R*),5β)]-3-[7-[2-(3,4-difluorophenyl)-cyclopropyl]amino]-5-(propylthio)-3H-1,2,3-triazolo[4,5-d]pyrimidin-3-yl)-5-(2-hydroxyethoxy)-cyclopentane-1,2-diol. This compound, and similar such compounds, are disclosed in WO 00/34283 and WO 99/05143. These compounds are disclosed as P 2T (which is now usually referred to as P 2 Y 12 ) receptor antagonists. Such antagonists can be used as, inter alia, inhibitors of platelet activation, aggregation or degranulation.
BACKGROUND OF THE INVENTION
[0003] Some processes are known for the production of optically active 2-cyclopropane carboxamide derivatives, optically active 2-aryl cyclopropylamine derivatives, and optically active 2-arylcyclopropane-1-carboxylate ester derivatives.
[0004] Examples of processes for the production of optically active 2-arylcyclopropane carboxamide derivatives are:
[0005] (i) A process wherein excess thionyl chloride is reacted with optically active 2-phenylcyclopropane carboxylic acid in benzene solvent to form corresponding acid chloride, and after concentrating down excess thionyl chloride and benzene under reduced pressure, the acid chloride is isolated and purified by distillation, and, by causing ammonia water to act on this, 2-phenylcyclopropane carboxamide is obtained (J. Am. Chem. Soc. Vol. 109, p. 2311 (1987), Journal of Medicinal Chemistry Vol. 20, p. 771 (1977)); and
[0006] (ii) A Process to obtain optically active 3-aryl-2-dimethylcyclopropane-1-carboxamide by causing ammonia water to act on the corresponding acid chloride formed by reacting thionyl chloride with optically active 3-aryl-2-dimethylcyclopropane-1-carboxylic acid (J. Org. Chem. Vol. 68, p. 621 (2003)).
[0007] Examples of processes for the production of optically active 2-aryl cyclopropylamine derivatives are:
[0008] (iii) A process wherein chlorocarbonic acid ethyl ester is reacted with 2-aryl cyclopropane carboxylic acid to form mixed acid anhydride, and by causing to act sodium azide on this, corresponding acid azide is formed, and 2-aryl cyclopropylamine is obtained by Curtius rearrangement with this (Journal of Medicinal Chemistry Vol. 20, p. 771 (1977), WO01/92263); and
[0009] (iv) A process to obtain corresponding 2,2-dimethyl cyclopropylamine by causing chlorine, bromine or sodium hypochlorite to act on the optically active 2,2-dimethylcyclopropane-1-carboxamide in the presence of base (Kokoku 5-3865);
[0010] Examples of a process for the production of optically active 2-arylcyclopropane carboxylate ester derivatives are:
[0011] (v) A process to obtain optically active cyclopropanecarboxylic acid derivative by cyclopropanation after deriving into optically active ester or amide via several steps using benzaldehyde derivative as the starting material (WO01/92263); and
[0012] (vi) A process to obtain optically active 2-dihydrofuranyl cyclopropanecarboxylate derivative by reacting phosphonoacetic acid ester derivative with optically active dihydrobenzofuranyl ethylene oxide derivative in the presence of base (Organic Process Research & Development, vol 6, p. 618 (2002)).
[0013] Examples of a process to produce optically active 2-aryl cyclopropylamine derivatives from optically active 2-aryl cyclopropanecarboxylic acid are:
[0014] (vii) A process wherein benzaldehydes is used as the starting material and derived into optically active ester or amide via several steps, and thereafter optically active 2-aryl cyclopropane carboxylate ester is obtained by cyclopropanation. This optically active carboxylic acid derivative is formed into acid azide, and optically active 2-aryl cyclopropylamine derivative is produced by Curtius rearrangement (WO01/92263).
[0015] In the process for the production of optically active 2-arylcyclopropane carboxamides referred to in (i) above, only the process to produce 2-phenylcyclopropane carboxamide from 2-phenylcyclopropane carboxylic acid is described and a process for production for 2-(disubstituted aryl)cyclopropane carboxamide derivative is not disclosed. Moreover, in the process (ii) above, there is mentioned the process for production only of 2,2-dimethyl-3-phenylcyclopropane carboxamide and 2,2-dimethyl-3-isopropylidene cyclopropane carboxamide, and a process for production of 2-(disubstituted aryl)cyclopropane carboxamide derivative is not disclosed.
[0016] Secondly, in a process for the production of optically active 2-aryl cyclopropylamine derivative, optically active 2-aryl cyclopropylamine derivative is produced by Curtius rearrangement from optically active 2-arylcyclopropane carboxylic acid in the aforesaid process (iii), however, it is not suitable for a commercial preparation method from the viewpoint of safety because it is via an acid azide intermediate having explosive properties. Moreover, in the process (iv), optically active amine is produced from the optically active carboxamide by a Hofmann rearrangement. However, it is not suitable for a commercial preparation method from the viewpoint of economy because yield is low when the reaction is carried out using the sodium hypochlorite. Moreover, as for the aforesaid process (iv), only the process to produce optically active 2,2-dimethyl cyclopropylamine from optically active 2,2-dimethylcyclopropane carboxamide is mentioned, and a process for production of 2-(disubstituted aryl)cyclopropane carboxamide derivative is not disclosed.
[0017] Thirdly, in a process for the production of optically active 2-arylcyclopropane carboxylate ester derivative, in the aforesaid process (v), optically active 3,4-difluorophenyl cyclopropanecarboxylic derivative is obtained by cyclopropanation after converting 3,4-difluoro benzaldehyde starting material into optically active ester or amide via several steps. However, it is not commercially suitable from the viewpoint of productivity and economy. For example, the starting material is expensive, the stereoselectivity is insufficient in the cyclopropanation and also there are many numbers of steps. Moreover, in process (vi), only an example of preparing optically active dihydrofuranyl cyclopropanecarboxylate ester from optically active dihydrobenzofuranyl ethylene oxide is mentioned. It is not a process for the production of general optical activity 2-arylcyclopropane carboxylate ester.
[0018] Fourthly, a process to produce optically active 2-aryl cyclopropylamine derivative from optically active 2-arylcyclopropane carboxylate ester derivative using (vii) is not commercially viable from a safety standpoint because the acid azide intermediate has expulsion properties. Also, purification is essential due to insufficient stereoselectivity during the cyclopropanation, making this process unsuitable for commercial preparation because of poor productivity.
[0019] Thus, the processes outlined are unsuitable for commercial production. There is a need for a commercial process which addresses areas such as safety, economy, productivity and the like.
SUMMARY OF THE INVENTION
[0020] The present invention provides processes for the production of an optically active cyclopropylamine compound represented by general formula (2), or a salt thereof,
[0000]
[0000] wherein each of R 1 , R 2 , R 3 , and R 4 is, independently, selected from a hydrogen atom, optionally substituted C 1-10 cyclic or acyclic alkyl group, optionally substituted C 6-10 aryl group or optionally substituted C 7-10 aralkyl group, and wherein * denotes an asymmetric carbon centre; characterised by the reaction of an optically active cyclopropane carboxamide compound represented by general formula (1)
[0000]
[0000] wherein each of R 1 , R 2 , R 3 , R 4 and * are the same as for the cyclopropylamine compound represented by general formula (2)) with hypochlorite in water in the presence of 5-30 equivalents of alkali metal hydroxide.
[0021] The present invention also provides processes for the production of an optically active 2-aryl cyclopropylamine compound represented by general formula (9), or a salt thereof,
[0000]
[0000] wherein * denotes an asymmetric carbon centre, and wherein an optically active 2-aryl cyclopropanecarboxylic acid compound represented by general formula (7), wherein * denotes an asymmetric carbon centre, is obtained,
[0000]
[0000] by de-esterifying an optically active 2-arylcyclopropane carboxylate ester compound represented by general formula (6)
[0000]
[0000] wherein R 5 is an optionally substituted C 1-10 cyclic or acyclic alkyl group, optionally substituted C 6-10 aryl group, or optionally substituted C 7-10 aralkyl group, and * denotes an asymmetric carbon centre, and wherein the compound of formula (6) is obtained by reacting an optically active styrene oxide compound represented by general formula (3)
[0000]
[0000] wherein * denotes an asymmetric carbon centre, or optically active halohydrin compound represented by general formula (4)
[0000]
[0000] wherein X denotes a halogen atom, and * denotes an asymmetric carbon centre, with a phosphonoacetic acid ester compound represented by general formula (5)
[0000]
[0000] wherein each R 5 and R 6 is, independently, a substituted C 1-10 cyclic or acyclic alkyl group, optionally substituted C 6-10 aryl group, or optionally substituted C 7-10 aralkyl group, in the presence of base; and thereafter, the 2-aryl cyclopropanecarboxylic acid compound of formula (7) obtained is activated by reaction with a carboxylic acid activator and thereafter reacting with ammonia to give the optically active 2-aryl cyclopropane carboxamide compound represented by obtained general formula (8)
[0000]
[0000] wherein * denotes an asymmetric carbon centre, which is reacted with an oxidant to give the compound of formula (9).
[0022] The present invention also provides processes for the production of optically active 2-aryl cyclopropane carboxamide compound represented by general formula (12)
[0000]
[0000] wherein R 7 is an aryl group substituted by 2 or more halogen atoms, and * denotes an asymmetric carbon centre, characterized in that, an optically active 2-aryl cyclopropanecarboxylic acid compound represented by general formula (10)
[0000]
[0000] wherein R 7 is an aryl group substituted by 2 or more halogen atoms, and * denotes an asymmetric carbon centre, is reacted with a carboxylic acid activator with the formation of an optically active 2-aryl cyclopropanecarboxylic acid compound represented by general formula (11)
[0000]
[0000] wherein R 7 is an aryl group substituted by 2 or more halogen atoms, Y is a carbonyl group activated group, and * denotes an asymmetric carbon centre, and thereafter this optically active 2-aryl cyclopropanecarboxylic acid compound represented by general formula (11) is reacted with ammonia.
[0023] The present invention also provides optically active 2-aryl cyclopropane carboxamide compounds represented by general formula (17)
[0000]
[0000] wherein, R 10 is an aryl group substituted by 2 or more halogen atoms, and * denotes an asymmetric carbon centre.
DESCRIPTION OF EMBODIMENTS
[0024] Efficient processes have now been discovered for the production of optically active 2-aryl cyclopropylamine derivatives or salts thereof. The processes afford high optical purity by using a readily available optically active styrene oxide derivative as the starting material. Efficient processes for the production of optically active cyclopropylamine derivative by a Hofmann rearrangement using sodium hypochlorite have been discovered. These processes can be used safely and inexpensively as commercial preparation methods.
[0025] Thus, according to the present invention there is provided a process for the production of optically active cyclopropylamine derivatives (or compounds) represented by general formula (2) or salts thereof
[0000]
[0026] (wherein R 1 , R 2 , R 3 or R 4 denote a hydrogen atom, optionally substituted C 1-10 cyclic or acyclic alkyl group, optionally substituted C 6-10 aryl group, or optionally substituted C 7-10 aralkyl group, and * denotes an asymmetric carbon centre), characterised by reacting optically active cyclopropane carboxamide derivative (or compound) represented by general formula (1)
[0000]
[0000] (wherein R 1 , R 2 , R 3 , R 4 and * have the same said definitions) with hypochlorite in water in the presence of alkali metal hydroxide of 5-30 equivalent.
[0027] Suitably, the hypochlorite is sodium hypochlorite; and in particular the quantity used of the hypochlorite is 1-5 mole equivalent with respect to compound of the formula (1). In a particular embodiment, there is provided a process for the production of optically active cyclopropylamine derivatives or salts thereof wherein R 1 , R 2 , R 3 is hydrogen atom and R 4 is 3,4-difluorophenyl group.
[0028] In a further embodiment, there is provided is a process for the production of an optically active 2-aryl cyclopropylamine derivative (or compound) represented by general formula (9) or a salt thereof,
[0000]
[0000] (wherein * denotes an asymmetric carbon centre), wherein an optically active 2-aryl cyclopropanecarboxylic acid derivative (or compound) represented by general formula (7)
[0000]
[0000] (wherein * denotes an asymmetric carbon centre) is obtained by de-esterifying the optically active 2-arylcyclopropane carboxylate ester derivative (or compound) represented by general formula (6)
[0000]
[0000] (wherein, R 5 denotes optionally substituted C 1-10 cyclic or acyclic alkyl group, optionally substituted C 6-10 aryl group, or optionally substituted C 7-10 aralkyl group, and * denotes an asymmetric carbon centre) which is obtained by reacting the optically active styrene oxide derivative (or compound) represented by general formula (3)
[0000]
[0029] (wherein * denotes an asymmetric carbon centre) or optically active halohydrin derivative (or compound) represented by or general formula (4)
[0000]
[0000] (wherein X denotes a halogen atom, and * denotes an asymmetric carbon centre) with phosphonoacetic acid ester derivative (or compound) represented by general formula (5)
[0000]
[0000] (wherein R 5 or R 6 denote optionally substituted C 1-10 cyclic or acyclic alkyl group, optionally substituted C 6-10 aryl group or optionally substituted C 7-10 aralkyl group) in the presence of base, and optically active 2-aryl cyclopropane carboxamide derivative (or compound) represented by obtained general formula (8)
[0000]
[0000] (wherein * denotes an asymmetric carbon centre) which is obtained by reacting the obtained aforesaid 2-aryl cyclopropanecarboxylic acid derivative (or compound) with ammonia after being activated with carboxylic acid activator is reacted with oxidant.
[0030] There is also provided a process for the production of optically an active 2-aryl cyclopropane carboxamide derivative (or compound) represented by general formula (12)
[0000]
[0000] (wherein R 7 denotes an aryl group substituted by 2 or more halogen atoms, and * denotes an asymmetric carbon centre) characterized by reacting with ammonia, optically active 2-aryl cyclopropanecarboxylic acid derivative (or compound) represented by general formula (11)
[0000]
[0000] (wherein, R 7 denotes an aryl group substituted by 2 or more halogen atoms, Y denotes carbonyl group activated group, and * denotes an asymmetric carbon centre) which is obtained from an optically active 2-aryl cyclopropanecarboxylic acid derivative (or compound) represented by general formula (10)
[0000]
[0000] (wherein R 7 denotes an aryl group substituted by 2 or more halogen atoms, and * denotes an asymmetric carbon centre) by reacting with a carboxylic acid activator.
[0031] There is also provided a process for the production of an optically active 2-aryl cyclopropane carboxamide derivative (or compound), wherein the reaction is carried out by using the compound of formula (10) obtained by de-esterifying an optically active 2-aryl cyclopropane carboxylate ester derivative (or compound) represented by general formula (13)
[0000]
[0000] (wherein R 8 denotes optionally substituted C 1-10 cyclic or acyclic alkyl group, optionally substituted C 6-10 aryl group, or optionally substituted C 7-10 aralkyl group, and R 7 and * have the same said definitions).
[0032] There is also provided a process for the production of an optically active 2-aryl cyclopropane carboxamide derivative (or compound), wherein the reaction is carried out by using the compound of formula (13) obtained by reacting the optically active styrene oxide derivative represented by general formula (14)
[0000]
[0000] (wherein R 7 and * have the same said definitions) or optically active halohydrin derivative (or compound) represented by general formula (15)
[0000]
[0000] (wherein R 7 and * have the same said definitions) with phosphonoacetic acid ester derivative (or compound) represented by general formula (16)
[0000]
[0000] (wherein R 9 denotes optionally substituted C 1-10 cyclic or acyclic alkyl group, optionally substituted C 6-10 aryl group, or optionally substituted C 7-10 aralkyl group, and R 8 and * have the same said definitions) in the presence of base. There is also provided a process for the production of an optically active 2-aryl cyclopropane carboxamide derivative (or compound) to obtain (1R,2R)-2-aryl cyclopropane carboxamide derivative (or compound) of formula (12) using a (1R,2R)-2-aryl cyclopropanecarboxylic acid derivative (or compound) of formula (10). The present invention also provides a process for the production of an optically active 2-aryl cyclopropane carboxamide derivative (or compound) to obtain a (1R,2R)-2-aryl cyclopropane carboxylic acid derivative (or compound) formula (10) using a (1R,2R)-2-aryl cyclopropane carboxylate ester derivative (or compound) of formula (13).
[0033] There is also provided a process for the production of an optically active 2-aryl cyclopropane carboxamide derivative (or compound) to obtain a (1R,2R)-2-aryl cyclopropane carboxylate ester derivative (or compound) of formula (13) using (S)-styrene oxide derivative formula (14) and (S)-halohydrin derivative (or compound) of formula (15). In particular, there is provided a process for the production of an optically active 2-aryl cyclopropane carboxamide derivative (or compound), wherein R 7 is 3,4-difluorophenyl group.
[0034] The present invention also provides an optically active 2-arylcyclopropane carboxamide derivative (or compound) represented by general formula (17)
[0000]
[0000] (wherein R 10 denotes an aryl group substituted by 2 or more halogen atoms, and * denotes an asymmetric carbon centre).
[0035] In particular, in the optically active 2-arylcyclopropane carboxamide derivative (or compound) of formula (17), R 10 is a 3,4-difluorophenyl group.
[0036] More particularly, the compound of formula (17) is a (1R,2R)-2-aryl cyclopropane carboxamide derivative (or compound).
[0037] The present invention provides a process for preparing an optically active aminocyclopropane derivative (or compound) from inexpensive 3,4-difluorobenzene using a Hoffmann re-arrangement. In general, the process is a safe and inexpensive way of preparing the optically active aminocycloprane derivative which is useful as an intermediate in the manufacture of pharmaceuticals and pesticides.
[0038] The conversion of compounds of formula (14) to (2) comprises 4 steps, namely in total: 1) cyclopropanation process, 2) deesterification process, 3) amidation process and 4) Hofmann rearrangement process. Hereinafter, the invention is described in detail for each process.
[0039] Firstly, there will be described 1) cyclopropanation process.
[0000]
Step 1. Cyclopropanation Process
[0040] In compounds represented by formula (14), R 7 denotes an aryl group substituted by 2 or more halogen atoms. Suitable values for R 7 include, for example, a 2,3-difluorophenyl group, 3,4-difluorophenyl group, 2,4-difluorophenyl group, 2,3,4-trifluorophenyl group, 3,4,5-trifluorophenyl group, 2,3,4,5-tetrafluorophenyl group, 2,3,4,5,6-pentafluorophenyl group, 2,3-dichlorophenyl group, 3,4-dichlorophenyl group, 2,4-dichlorophenyl group, 2,3,4-trichlorophenyl group, 3,4,5-trichlorophenyl group, 2,3,4,5-tetrachlorophenyl group, 2,3,4,5,6-pentachlorophenyl group, 2,3-dibromophenyl group, 3,4-dibromophenyl group, 2,4-dibromophenyl group, 2,3,4-tribromophenyl group, 3,4,5-tribromophenyl group, 2,3,4,5-tetrabromophenyl group, and a 2,3,4,5,6-pentabromo phenyl group. A 3,4-difluorophenyl group is preferred. Moreover, * denotes an asymmetric carbon centre. In other words, a styrene oxide derivative formula (14) contains an asymmetric carbon centre. This invention includes any optically active substance or racemic mixture of the compound of formula (14). Preferably, it is optically active substance, and most preferably it is a compound whose absolute configuration of asymmetric carbon centre is (S).
[0041] In the compound of formula (15), R 7 denotes an aryl group substituted by 2 or more halogen atoms, and X denotes a halogen atom. Suitable values for R 7 include, for example, a 2,3-difluorophenyl group, 3,4-difluorophenyl group, 2,4-difluorophenyl group, 2,3,4-trifluorophenyl group, 3,4,5-trifluorophenyl group, 2,3,4,5-tetrafluorophenyl group, 2,3,4,5,6-pentafluorophenyl group, 2,3-dichlorophenyl group, 3,4-dichlorophenyl group, 2,4-dichlorophenyl group, 2,3,4-trichlorophenyl group, 3,4,5-trichlorophenyl group, 2,3,4,5-tetrachlorophenyl group, 2,3,4,5,6-pentachlorophenyl group, 2,3-dibromophenyl group, 3,4-dibromophenyl group, 2,4-dibromophenyl group, 2,3,4-tribromophenyl group, 3,4,5-tribromophenyl group, 2,3,4,5-tetrabromophenyl group, and a 2,3,4,5,6-pentabromo phenyl group. A 3,4-difluorophenyl group is preferred.
[0042] Moreover, * denotes an asymmetric carbon centre. In other words, the halohydrin derivative represented by general formula (15) contains asymmetric carbon centre. The invention includes any optically active substance or racemic mixture of the compound of formula (15). Preferably it is optically active substance, and most preferably it is a compound whose absolute configuration of asymmetric carbon centre is (S).
[0043] In the compound of formula (16), R 8 denotes an optionally substituted C 1-10 cyclic or acyclic alkyl group, optionally substituted C 6-10 aryl group, or optionally substituted C 7-10 aralkyl group, and R 9 denotes an optionally substituted C 1-10 cyclic or acyclic alkyl group, optionally substituted C 6-10 aryl group, or optionally substituted C 7-10 aralkyl group. Suitable values for a C 1-10 cyclic or acyclic alkyl group include for example, a methyl group, ethyl group, n-propyl group, i-propyl group, cyclopropyl group, n-butyl group, s-butyl group, i-butyl group, t-butyl group, cyclobutyl group, n-pentyl group, neopentyl group, cyclopentyl group, n-hexyl group, cyclohexyl group, n-heptyl group, cyclohexylmethyl group, n-octyl group, and n-decyl group. Suitable values for an optionally substituted C 6-10 aryl group include for example phenyl group, o-methoxyphenyl group, m-methoxyphenyl group, p-methoxy phenyl group, o-nitrophenyl group, m-nitrophenyl group, p-nitrophenyl group, o-chlorophenyl group, m-chlorophenyl group, p-chlorophenyl group, o-methylphenyl group, m-methylphenyl group, and p-methylphenyl group. Suitable values for an optionally substituted C 7-10 aralkyl group include, for example, a benzyl group, o-methoxybenzyl group, m-methoxybenzyl group, p-methoxybenzyl group, o-nitrobenzyl, m-nitrobenzyl, p-nitrobenzyl, o-chlorobenzyl group, m-chlorobenzyl group, p-chlorobenzyl group, o-methylbenzyl group, m-methylbenzyl group, and p-methylbenzyl group.
[0044] In particular one or both of R 8 and R 9 are methyl group or ethyl group, and preferably both of R 8 and R 9 are methyl group or ethyl group.
[0045] In the compound of formula (13), values of substituents R 7 , R 8 originate from respective values in the styrene oxide derivative of formula (14) or a halohydrin derivative represented by the formula (15) and carboxylate ester derivative represented by general formula (16). In other words, R 7 denotes an aryl group substituted by 2 or more halogen atoms, and R 8 denotes optionally substituted C 1-10 cyclic or acyclic alkyl group, optionally substituted C 6-10 aryl group, or optionally substituted C 7-10 aralkyl group, and R 9 denotes optionally substituted C 1-10 cyclic or acyclic alkyl group, optionally substituted C 6-10 aryl group, or optionally substituted C 7-10 aralkyl group. Suitable values for an aryl group substituted by 2 or more halogen atoms, include, for example, a 2,3-difluorophenyl group, 3,4-difluorophenyl group, 2,4-difluorophenyl group, 2,3,4-trifluorophenyl group, 3,4,5-trifluorophenyl group, 2,3,4,5-tetrafluorophenyl group, 2,3,4,5,6-pentafluorophenyl group, 2,3-dichlorophenyl group, 3,4-dichlorophenyl group, 2,4-dichlorophenyl group, 2,3,4-trichlorophenyl group, 3,4,5-trichlorophenyl group, 2,3,4,5-tetrachlorophenyl group, 2,3,4,5,6-pentachlorophenyl group, 2,3-dibromophenyl group, 3,4-dibromophenyl group, 2,4-dibromophenyl group, 2,3,4-tribromophenyl group, 3,4,5-tribromophenyl group, 2,3,4,5-tetrabromophenyl group, and 2,3,4,5,6-pentabromo phenyl group. Suitable values for a C 1-10 cyclic or acyclic alkyl group, include, for example, a methyl group, ethyl group, n-propyl group, i-propyl group, cyclopropyl group, n-butyl group, s-butyl group, i-butyl group, t-butyl group, cyclobutyl group, n-pentyl group, neopentyl group, cyclopentyl group, n-hexyl group, cyclohexyl group, n-heptyl group, cyclohexylmethyl group, n-octyl group, and n-decyl group. Suitable values for an optionally substituted C 6-10 aryl group include, for example, a phenyl group, o-methoxyphenyl group, m-methoxyphenyl group, p-dimethoxy phenyl group, o-nitrophenyl group, m-nitrophenyl group, p-nitrophenyl group, o-chlorophenyl group, m-chlorophenyl group, p-chlorophenyl group, o-methylphenyl group, m-methylphenyl group, and p-methylphenyl group. Suitable values for an optionally substituted C 7-10 aralkyl group include, for example, a benzyl group, o-methoxybenzyl group, m-methoxybenzyl group, p-methoxybenzyl group, o-nitrobenzyl, m-nitrobenzyl, p-nitrobenzyl, o-chlorobenzyl group, m-chlorobenzyl group, p-chlorobenzyl group, o-methylbenzyl group, m-methylbenzyl group, and p-methylbenzyl group. It is generally preferred that R 7 is a 3,4-difluorophenyl group and R 8 is an ethyl group.
[0046] Moreover, * denotes an asymmetric carbon centre. In other words, an ester derivative represented by the formula (13) contains asymmetric carbon centres. The invention includes any optically active substance or racemic mixture of the compound of formula (13). Preferably it is an optically active substance, and most preferably it is a compound whose absolute configuration of asymmetric carbon centre is (1R, 2R).
[0047] The optically active halohydrin derivative represented by the formula (15) which is a starting material of this invention can be readily obtained, for example, by enantioselectively reacting a α-halomethyl arylketone derivative obtained by reacting a benzene derivative with α-halo acetic acid chloride in the presence of aluminum chloride. The optically active styrene oxide derivative of formula (14) can be readily obtained by epoxidation of an optically active α-halohydrin derivative of formula (15).
[0048] A compound of formula (14) or of formula (15) is reacted with a compound of formula (16) in the presence of base and thereby converted to compound of formula (13). Examples of suitable bases include, for example, an organolithium compound such as methyllithium, n-butyllithium, t-butyllithium, phenyl lithium or the like, a Grignard reagent such as n-butylmagnesiumchloride, methyl magnesium bromide or the like; an alkaline earth metal amide or alkali metal amide such as lithium amide, sodium amide, lithium diisopropyl amide, magnesium diisopropyl amide, lithium hexamethyl disilazide, sodium hexamethyl disilazide, potassium hexamethyl disilazide or the like; an alkali metal alkoxide such as sodium methoxide, sodium ethoxide, sodium-t-butoxide, lithium methoxide, lithium ethoxide, lithium-t-butoxide, potassium-t-butoxide or the like; an alkaline earth metal hydride or alkali metal hydride such as lithium hydride, sodium hydride, potassium hydride, calcium hydride or the like.
[0049] A base of an alkali metal-t-butoxide, alkali metal hydride or the like is generally preferred.
[0050] The quantity of base used differs depending on species of base used, species of solvent and reaction conditions. A particular quantity is a 1-5 fold molar ratio, preferably 1-3 fold molar ratio with respect to compound of formula (14) or (15).
[0051] The quantity of compound of formula (16) used differs depending on species of solvent and reaction conditions. A particular quantity is a 1-5 fold molar ratio, preferably 1-3 fold molar ratio with respect to compound of formula (14) or (15).
[0052] In general, a solvent is usually used in the reaction. Examples include, for example, dichloromethane, chloroform, dichloroethane, benzene, toluene, diethyl ether, ethylene glycol dimethylether, methyl-t-butyl ether, diisopropyl ether, tetrahydrofuran, 1,4-dioxane, N,N-dimethylformamide, N-methylpyrrolidone, 1,3-dimethyl imidazolidinone, dimethylsulfoxide, acetone, acetonitrile, ethyl acetate, isopropyl acetate ester, acetic acid-t-butyl, t-butanol, and the like. The solvent may be used alone or as an admixture thereof, and in this case, the mixed proportions thereof are not restricted.
[0053] A solvent of toluene, ethylene glycol dimethylether, tetrahydrofuran or 1,4-dioxane is generally preferred.
[0054] Suitable values of the reaction temperature include values selected from the range of −30° C. to boiling point of solvent used, and a temperature in the range of 20° C.-90° C. Generally, the reaction time required is usually 30 minutes to 24 hours.
[0055] On completion of the reaction, solvent may be removed by distillation. The reaction mixture may then be added to water or water is added to it, and thereafter, it may be neutralized by addition of an appropriate quantity of acid. The compound of formula (13) may be obtained by using procedures such as extraction with an organic solvent such as toluene, ethyl acetate, isopropyl acetate, diethyl ether, dichloromethane, chloroform or the like, washing with water and concentration. The compound obtained may be purified further by column chromatography or distillation.
[0056] Examples of the acid used for neutralization after completion of the reaction include, but are not limited to, organic carboxylic acid such as formic acid, acetic acid, propionic acid, trifluoroacetic acid, chloroacetic acid, dichloroacetic acid, trichloroacetic acid, oxalic acid, benzoic acid, phthalic acid, fumaric acid, mandelic acid or the like; an optically active organic carboxylic acid such as tartaric acid, lactic acid, ascorbic acid, amino acid or the like; an organic sulfonic acid such as methanesulfonic acid, trifluoromethanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, camphor sulfonic acid or the like; an inorganic acid such as hydrochloric acid, sulphuric acid, nitric acid, phosphoric acid, carbonic acid or the like. Hydrochloric acid or sulfuric acid are generally preferred.
[0057] Next, there will be described 2) deesterification process.
[0000]
Step 2. Deesterification Process
[0058] The values of R 7 , R 8 and * in the compound of formula (13), including the suitable and preferred values, are the same as those mentioned above in 1) cyclopropanation process. In the compound of formula (10), the values of substituent R 7 including the suitable and preferred values, originate from the ester derivative of formula (13). In other words, R 7 denotes an aryl group substituted by 2 or more halogen atoms. Suitable values of an aryl group substituted by 2 or more halogen atoms include, for example, a 2,3-difluorophenyl group, 3,4-difluorophenyl group, 2,4-difluorophenyl group, 2,3,4-trifluorophenyl group, 3,4,5-trifluorophenyl group, 2,3,4,5-tetrafluorophenyl group, 2,3,4,5,6-pentafluorophenyl group, 2,3-dichlorophenyl group, 3,4-dichlorophenyl group, 2,4-dichlorophenyl group, 2,3,4-trichlorophenyl group, 3,4,5-trichlorophenyl group, 2,3,4,5-tetrachlorophenyl group, 2,3,4,5,6-pentachlorophenyl group, 2,3-dibromophenyl group, 3,4-dibromophenyl group, 2,4-dibromophenyl group, 2,3,4-tribromophenyl group, 3,4,5-tribromophenyl group, 2,3,4,5-tetrabromophenyl group or 2,3,4,5,6-pentabromophenyl group. A 3,4-difluorophenyl group is generally preferred.
[0059] Moreover, * denotes an asymmetric carbon centre. In other words the carboxylic acid derivative of formulae (10) contains asymmetric carbon centres. The invention includes any optically active substance or racemic mixture of the compound of formula (10). Preferably it is an optically active substance, and most preferably it is a compound whose absolute configuration of asymmetric carbon centre is (1R,2R).
[0060] In this step, the compound of formula (13) is converted to the compound of formula (10) by deesterifying, and reaction conditions of deesterification of Compound (13) are not restricted. The reaction may be carried out using general deesterification conditions. Examples of conditions for deesterification include a process of oxidative elimination of p-methoxybenzyl ester using DDQ (2,3-dichloro-5,6-dicyanobenzoquinone) and CAN (cerium nitrate), a process to eliminate benzyl ester, t-butyl ester using iodotrimethylsilane, a process of reductive elimination of benzyl ester using palladium catalyst under a hydrogen atmosphere, a process to eliminate t-butyl ester using TFA (trifluoroacetic acid), a process to eliminate ester group by acid or alkali hydrolysis, or the like. From the point of inexpensiveness and the point that the process can be applied for most kinds of ester group, the process to eliminate ester group by acid or alkali hydrolysis is preferred, and the process to eliminate ester group by alkali hydrolysis is more preferred.
[0061] Suitable alkalis include an alkali metal hydroxide such as lithium hydroxide, sodium hydroxide, potassium hydroxide, cesium hydroxide or the like; an alkaline earth metal hydroxide such as magnesium hydroxide, calcium hydroxide, barium hydroxide or the like; an alkali metal carbonate such as lithium carbonate, sodium carbonate, potassium carbonate, cesium carbonate or the like. An inorganic acid such as hydrochloric acid, sulphuric acid, nitric acid, phosphoric acid, perchloric acid or the like are generally preferred.
[0062] Suitable reaction solvents for deesterification include, for example, water, tetrahydrofuran, 1,4-dioxane, diethyl ether, methyl-t-butyl ether, toluene, benzene, N,N-dimethylformamide, dimethylsulfoxide, dichloromethane, chloroform, acetone, acetonitrile, butanol, propanol, ethanol, methanol, water and the like. The solvent may be used alone or as a mixture thereof, and in this case, the mixed proportions are not limited in particular.
[0063] In general, a solvent of toluene, tetrahydrofuran, ethanol or methanol is preferred.
[0064] Suitable reaction temperatures, include those selected from the range of −30° C. to boiling point of solvent used, and preferably it is 0° C.-80° C. The reaction time is required usually to be 30 minutes to 27 hours.
[0065] On completion of the reaction, the solvent may be removed by distillation, and thereafter the mixture added to water or water is added to it as required. The mixture is neutralized by addition of acid. The compound of formula (10) may be obtained by procedures such as extraction with an organic solvent such as toluene, ethyl acetate, isopropyl acetate, diethyl ether, dichloromethane, chloroform or the like; washing with water, concentration and the like. The obtained compound may be further purified by column chromatography or crystallisation, or it may be used in the following step without treatment.
[0066] Suitable acids used for neutralization after completion of the reaction include, for example, an organic carboxylic acid such as formic acid, acetic acid, propionic acid, trifluoroacetic acid, chloroacetic acid, dichloroacetic acid, trichloroacetic acid, oxalic acid, benzoic acid, phthalic acid, fumaric acid, mandelic acid or the like; an optically active organic carboxylic acid such as tartaric acid, lactic acid, ascorbic acid, amino acid or the like; an organic sulfonic acid such as methanesulfonic acid, trifluoromethanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, camphor sulfonic acid or the like; an inorganic acid such as hydrochloric acid, sulphuric acid, nitric acid, phosphoric acid, carbonic acid or the like. Hydrochloric acid and sulfuric acid are generally preferred.
[0067] Next, a description will be given of 3) amidation process.
[0000]
Step 3. Amidation Process
[0068] In the compound of formula (10), the values of substituent R 7 and * (including the suitable and preferred values) are the same as those mentioned above in 2) deesterification process.
[0069] In the compound of formula (11), values of substituent R 7 originate from the ester derivative of formula (10). In other words, R 7 may represent an aryl group substituted by 2 or more halogen atoms. Suitable values for an aryl group substituted by 2 or more halogen atoms include a 2,3-difluorophenyl group, 3,4-difluorophenyl group, 2,4-difluorophenyl group, 2,3,4-trifluorophenyl group, 3,4,5-trifluorophenyl group, 2,3,4,5-tetrafluorophenyl group, 2,3,4,5,6-pentafluorophenyl group, 2,3-dichlorophenyl group, 3,4-dichlorophenyl group, 2,4-dichlorophenyl group, 2,3,4-trichlorophenyl group, 3,4,5-trichlorophenyl group, 2,3,4,5-tetrachlorophenyl group, 2,3,4,5,6-pentachlorophenyl group, 2,3-dibromophenyl group, 3,4-dibromophenyl group, 2,4-dibromophenyl group, 2,3,4-tribromophenyl group, 3,4,5-tribromophenyl group, 2,3,4,5-tetrabromophenyl group, 2,3,4,5,6-pentabromo phenyl group or the like. A 3,4-difluorophenyl group is generally preferred. Moreover, Y denotes an activated carbonyl group activated group, and it is derived from the carboxylic acid activator described later.
[0070] Moreover, * denotes an asymmetric carbon centre. In other words the carboxylic acid derivative of formula (11) contains asymmetric carbon centres. The invention includes any optically active substance or racemic mixture of the compound of formula (11). Preferably it is an optically active substance, and most preferably it is a compound whose absolute configuration of asymmetric carbon centre is (1R,2R).
[0071] In the compound of formula (12), values of substituent R 7 originate from the ester derivative of formula (10). In other words, R 7 may denote an aryl group substituted by 2 or more halogen atoms. Suitable values for an aryl group substituted by 2 or more halogen atoms include a 2,3-difluorophenyl group, 3,4-difluorophenyl group, 2,4-difluorophenyl group, 2,3,4-trifluorophenyl group, 3,4,5-trifluorophenyl group, 2,3,4,5-tetrafluorophenyl group, 2,3,4,5,6-pentafluorophenyl group, 2,3-dichlorophenyl group, 3,4-dichlorophenyl group, 2,4-dichlorophenyl group, 2,3,4-trichlorophenyl group, 3,4,5-trichlorophenyl group, 2,3,4,5-tetrachlorophenyl group, 2,3,4,5,6-pentachlorophenyl group, 2,3-dibromophenyl group, 3,4-dibromophenyl group, 2,4-dibromophenyl group, 2,3,4-tribromophenyl group, 3,4,5-tribromophenyl group, 2,3,4,5-tetrabromophenyl group, 2,3,4,5,6-pentabromo phenyl group or the like. A 3,4-difluorophenyl group is generally preferred.
[0072] Moreover, * denotes an asymmetric carbon centre. In other words, the carboxylic acid derivative of formula (12) contains asymmetric carbon centres. The invention includes any optically active substance or racemic mixture of the compound of formula (12). Preferably, it is an optically active substance, and most preferably it is a compound whose absolute configuration of asymmetric carbon centre is (1R,2R).
[0073] The compound of formula (10) may be formed into the compound of formula (11) by reacting with a carboxylic acid activator to activate the carbonyl moiety. The activated compound is converted to the compound of formula (12) by reacting with ammonia. Suitable carboxylic acid activators include, for example, a dehydrocondensation agent such as dicyclohexylcarbodiimide (DCC) and carbonyldiimidazole; chlorocarbonic acid esters such as methyl chlorocarbonate ester, ethyl chlorocarbonate ester, propyl chlorocarbonate ester, isopropyl chlorocarbonate ester, chlorocarbonate butyl ester, t-butyl chlorocarbonate, benzyl chlorocarbonate or the like; an acid anhydride such as acetic anhydride, anhydrous trifluoroacetic acid, anhydrous methanesulfonic acid, anhydrous trifluoromethanesulfonic acid or the like; an carboxylic acid ester species such as carbonic acid di-t-butyl, dimethyl carbonate, diethyl carbonate or the like, acid chloride such as methanesulfonyl chloride, p-toluenesulphonyl chloride, phosphorus pentachloride, phosphorus trichloride, phosphorus oxychloride, acetyl chloride, propionyl chloride, pivaloyl chloride, benzoyl chloride, thionyl chloride, chlorosulfuric acid, oxalyl chloride; phosgene or the like, and a metal chloride such as titanium chloride, aluminum chloride, ferric chloride or the like may be proposed.
[0074] Particular carboxylic acid activators are chlorocarbonate ester, acid anhydride, carboxylic acid ester, acid chloride except phosgene. In general thionyl chloride is preferred particularly as it offers advantages from the point of handling and post-treatment after reaction.
[0075] The quantity used of carboxylic acid activator differs depending on species of base used and species of solvent and of reaction conditions. In particular a 1-3 fold molar ratio may be used, and preferably a 1-1.5 fold molar ratio with respect to compound represented by the aforesaid formula (10).
[0076] When reacting the compound of formula (10) with the carboxylic acid activator, a base may be used in accordance with requirements. Suitable bases include, for example, an organolithium compound such as methyllithium, n-butyllithium, t-butyllithium, phenyl lithium or the like, a Grignard reagent such as n-butyl magnesium chloride, methyl magnesium bromide or the like, alkaline earth metal amide or alkali metal amide such as lithium amide, sodium amide, lithium diisopropyl amide, magnesium diisopropyl amide, lithium hexamethyl disilazide, sodium hexamethyl disilazide, potassium hexamethyl disilazide or the like, alkali metal alkoxide such as sodium methoxide, sodium ethoxide, sodium-t-butoxide, lithium methoxide, lithium ethoxide, lithium-t-butoxide, potassium-t-butoxide or the like, alkaline earth metal hydride or alkali metal hydride such as lithium hydride, sodium hydride, potassium hydride, calcium hydride or the like, alkaline earth metal hydroxide or alkali metal hydroxide such as lithium hydroxide, sodium hydroxide, potassium hydroxide, cesium hydroxide, magnesium hydroxide, calcium hydroxide or the like, alkali metal carbonate such as lithium carbonate, sodium carbonate, potassium carbonate or the like, alkali metal bicarbonate such as lithium bicarbonate, sodium bicarbonate, potassium bicarbonate or the like, organic tertiary amine such as triethylamine, diisopropyl ethylamine, DBU (1,8-diazabicyclo[5,4,0]undecene) or the like, basic organic solvent such as N,N-dimethylformamide or the like.
[0077] In particular, the base may be an alkali metal alkoxide, alkaline earth metal hydride or alkali metal hydride, alkaline earth metal hydroxide or alkali metal hydroxide, alkaline earth carbonate or alkali metal carbonate, alkali metal bicarbonate, or organic tertiary amine. In general an alkaline earth metal hydroxide or alkali metal hydroxide, alkaline earth carbonate or alkali metal carbonate, alkali metal bicarbonate, organic tertiary amine or the like is preferred.
[0078] The quantity used of base differs depending on the species of base used and species of solvent and reaction conditions. In particular a 1-3 fold molar ratio may be used, and preferably a 1-1.5 fold molar ratio with respect to compound represented by the aforesaid formula (10).
[0079] Suitable forms of the ammonia used include, for example, liquid ammonia, ammonia gas, ammonia solution in organic solvent and ammonia water. Particular examples are ammonia gas, ammonia in an organic solvent, ammonia water, and ammonia water is generally preferred.
[0080] When the form of ammonia is ammonia water the concentration of ammonia water used is not limited. In particular 5-30 wt % may be used, and 20-28 wt % is generally preferred.
[0081] The quantity of ammonia used differs depending on the form of used ammonia, species of solvent and reaction conditions. In particular, a 1-6 fold molar ratio may be used, and, preferably, a 3-5 fold molar ratio with respect to compound represented by the aforesaid formula (10).
[0082] Generally a solvent is usually used in the reaction. Suitable solvents include for example dichloromethane, chloroform, dichloroethane, benzene, toluene, diethyl ether, methyl-t-butyl ether, diisopropyl ether, tetrahydrofuran, 1,4-dioxane, N,N-dimethylformamide, N-methylpyrrolidone, 1,3-dimethyl imidazolidinone, dimethylsulfoxide, acetone, acetonitrile, ethyl acetate, isopropyl acetate ester and acetic acid-t-butyl and the like.
[0083] The solvent may be used alone or by mixing, and in this case, the mixing proportion is not limited. Generally a solvent of toluene, ethyl acetate and isopropyl acetate are preferred.
[0084] Suitable reaction temperatures, include those selected from the range of −30° C. to boiling point of solvent used and preferably it is selected from the range of 0° C.-60° C. The reaction time required is usually 10 minutes to 24 hours.
[0085] On completion of the reaction, the solvent is removed by distillation in accordance with requirements, and thereafter the reaction mixture is added to water or water is added to it. The compound of formula (12) is obtained using procedures such as extraction with an organic solvent such as toluene, ethyl acetate, isopropyl acetate ester, diethyl ether, dichloromethane, chloroform or the like, washing with water, and concentration. The obtained compound may be further purified by column chromatography or crystallisation, or it may be used in the following step without treatment.
[0086] The compound of formula (17)
[0000]
[0000] produced by the aforesaid process is a novel compound, and is therefore provided as a further feature of the present invention. In formula (17), R 10 denotes an aryl group substituted by 2 or more halogen atoms. Suitable values for the aryl group substituted by 2 or more halogen atoms include a 2,3-difluorophenyl group, 3,4-difluorophenyl group, 2,4-difluorophenyl group, 2,3,4-trifluorophenyl group, 3,4,5-trifluorophenyl group, 2,3,4,5-tetrafluorophenyl group, 2,3,4,5,6-pentafluorophenyl group, 2,3-dichlorophenyl group, 3,4-dichlorophenyl group, 2,4-dichlorophenyl group, 2,3,4-trichlorophenyl group, 3,4,5-trichlorophenyl group, 2,3,4,5-tetrachlorophenyl group, 2,3,4,5,6-pentachlorophenyl group, 2,3-dibromophenyl group, 3,4-dibromophenyl group, 2,4-dibromophenyl group, 2,3,4-tribromophenyl group, 3,4,5-tribromophenyl group, 2,3,4,5-tetrabromophenyl group, 2,3,4,5,6-pentabromo phenyl group or the like. A 3,4-difluorophenyl group is generally preferred.
[0087] Moreover, * denotes an asymmetric carbon centre. In other words, the carboxamide derivative of formulae (17) contains asymmetric carbon centres. The invention includes any optically active substance or racemic mixture of the compound of formula (17). Preferably it is optically active substance, and most preferably it is a compound whose absolute configuration of asymmetric carbon centre is (1R,2R).
[0088] Next, a description will be given of 4) Hofmann rearrangement process.
[0000]
Step 4. Hofmann Rearrangement Step
[0089] In the compound of formula (1), R 1 , R 2 , R 3 and R 4 each independently denote hydrogen atom, optionally substituted C 1-10 cyclic or acyclic alkyl group, optionally substituted C 6-10 aryl group or optionally substituted C 7-10 aralkyl group, and they may be the same or different to each other. Suitable values of an optionally substituted cyclic or acyclic alkyl group of carbon number 1-10 include a methyl group, ethyl group, n-propyl group, i-propyl group, cyclopropyl group, n-butyl group, s-butyl group, i-butyl group, t-butyl group, cyclobutyl group, n-pentyl group, neopentyl group, cyclopentyl group, n-hexyl group, cyclohexyl group, n-heptyl group, cyclohexylmethyl group, n-octyl group, n-decyl group and the like. Suitable values of an optionally substituted C 6-10 aryl group include a phenyl group, o-methoxyphenyl group, m-methoxyphenyl group, p-dimethoxy phenyl group, o-nitrophenyl group, m-nitrophenyl group, p-nitrophenyl group, o-fluorophenyl group, m-fluorophenyl group, p-fluorophenyl group, o-chlorophenyl group, m-chlorophenyl group, p-chlorophenyl group, 2,3-difluorophenyl group, 3,4-difluorophenyl group, 2,4-difluorophenyl group, 2,3,4-trifluorophenyl group, 3,4,5-trifluorophenyl group, 2,3,4,5-tetrafluorophenyl group, 2,3,4,5,6-pentafluorophenyl group, 2,3-dichlorophenyl group, 3,4-dichlorophenyl group, 2,4-dichlorophenyl group, 2,3,4-trichlorophenyl group, 3,4,5-trichlorophenyl group, 2,3,4,5-tetrachlorophenyl group, 2,3,4,5,6-pentachlorophenyl group, 2,3-dibromophenyl group, 3,4-dibromophenyl group, 2,4-dibromophenyl group, 2,3,4-tribromophenyl group, 3,4,5-tribromophenyl group, 2,3,4,5-tetrabromophenyl group, 2,3,4,5,6-pentabromo phenyl group, o-methylphenyl group, m-methylphenyl group, p-methylphenyl group and the like. Suitable values of an optionally substituted C 7-10 aralkyl group include a benzyl group, o-methoxybenzyl group, m-methoxybenzyl group, p-methoxybenzyl group, o-nitrobenzyl group, m-nitrobenzyl group, p-nitrobenzyl group, o-chlorobenzyl group, m-chlorobenzyl group, p-chlorobenzyl group, o-methylbenzyl group, m-methylbenzyl group, p-methylbenzyl group and the like. Preferably any of R 1 , R 2 , R 3 and R 4 is a 3,4-difluorophenyl group, and more preferably the substituent except 3,4-difluorophenyl group is a hydrogen atom.
[0090] Moreover, * denotes an asymmetric carbon centre. In other words, the compound of formula (1) has asymmetric carbon centre. The invention includes any optically active substance or racemic mixture of the compound of formula (1). Preferably it is optically active substance, and most preferably it is a compound whose absolute configuration of asymmetric carbon centre is (1R,2R).
[0091] In the compound of formula (2), values (including suitable and preferred) for R 1 , R 2 , R 3 and R 4 originate from the compound of formula (1). In other words, R 1 , R 2 , R 3 and R 4 each independently denote a hydrogen atom, an optionally substituted C 1-10 cyclic or an acyclic alkyl group, optionally substituted C 6-10 aryl group, or optionally substituted C 7-10 aralkyl group, and they may be the same or different to each other. Suitable values for an optionally substituted C 1-10 cyclic or acyclic alkyl group include a methyl group, ethyl group, n-propyl group, i-propyl group, cyclopropyl group, n-butyl group, s-butyl group, i-butyl group, t-butyl group, cyclobutyl group, n-pentyl group, neopentyl group, cyclopentyl group, n-hexyl group, cyclohexyl group, n-heptyl group, cyclohexylmethyl group, n-octyl group, n-decyl group and the like. Suitable values for an optionally substituted C 6-10 aryl group include a phenyl group, o-methoxyphenyl group, m-methoxyphenyl group, p-dimethoxy phenyl group, o-nitrophenyl group, m-nitrophenyl group, p-nitrophenyl group, o-fluorophenyl group, m-fluorophenyl group, p-fluorophenyl group, o-chlorophenyl group, m-chlorophenyl group, p-chlorophenyl group, 2,3-difluorophenyl group, 3,4-difluorophenyl group, 2,4-difluorophenyl group, 2,3,4-trifluorophenyl group, 3,4,5-trifluorophenyl group, 2,3,4,5-tetrafluorophenyl group, 2,3,4,5,6-pentafluorophenyl group, 2,3-dichlorophenyl group. 3,4-dichlorophenyl group, 2,4-dichlorophenyl group, 2,3,4-trichlorophenyl group, 3,4,5-trichlorophenyl group, 2,3,4,5-tetrachlorophenyl group, 2,3,4,5,6-pentachlorophenyl group, 2,3-dibromophenyl group, 3,4-dibromophenyl group, 2,4-dibromophenyl group, 2,3,4-tribromophenyl group, 3,4,5-tribromophenyl group, 2,3,4,5-tetrabromophenyl group, 2,3,4,5,6-penta bromo phenyl group, o-methylphenyl group, m-methylphenyl group, p-methylphenyl group and the like. Suitable values for an optionally substituted C 7-10 aralkyl group include a benzyl group, o-methoxybenzyl group, m-methoxybenzyl group, p-methoxybenzyl group, o-nitrobenzyl group, m-nitrobenzyl group, p-nitrobenzyl group, o-chlorobenzyl group, m-chlorobenzyl group, p-chlorobenzyl group, o-methylbenzyl group, m-methylbenzyl group, p-methylbenzyl group and the like. Wherein preferably any of R 1 , R 2 , R 3 and R 4 is a 3,4-difluorophenyl group, and more preferably, the substituent other than 3,4-difluorophenyl group is hydrogen atom.
[0092] Moreover, * denotes an asymmetric carbon centre. In other words, the compound represented by the formula (2) has asymmetric carbon centre. The invention includes any optically active substance or racemic mixture of the compound of formula (2). Preferably it is optically active substance, and most preferably it is a compound whose absolute configuration of asymmetric carbon centre is (1R, 2S).
[0093] When oxidant is caused to act, there proceeds a so-called Hofmann rearrangement, and the compound of formula (1) is converted to the compound of formula (2) while maintaining the stereochemistry of the asymmetric carbon centre represented by *. For example, suitable oxidants include a high valency iodine reagent exemplified by bis (trifluoroacetoxy)phenyl iodide, halide agent such as chlorine, bromine, iodine, N-chlorosuccinimide, N-bromosuccinimide, N-iodosuccinimide, sulphuryl chloride, sulphuryl bromide or the like, hypochlorite species such as lithium hypochlorite, sodium hypochlorite, potassium hypochlorite, magnesium hypochlorite, calcium hypochlorite or the like may be proposed, and chlorine, N-chloro succinimide, hypochlorite species or the like. In general sodium hypochlorite is preferred.
[0094] The quantity of oxidant used differs depending on species of oxidant used, species of reaction solvent and reaction conditions. In particular a 1-5 fold molar ratio may be used and preferably a 2-4 fold molar ratio with respect to the compound of formula (1). Moreover, as regards the quantity used of the aforesaid oxidant, when a hypochlorite species is used as the oxidant, the quantity used is determined by effective chlorine conversion.
[0095] In the reaction of compound of formula (1) and oxidant, a base may be co-present in accordance with requirements. Base may be added after mixing the compound of formulae (1) and oxidant. Suitable bases include, for example, an organolithium compound such as methyllithium, n-butyllithium, t-butyllithium, phenyl lithium or the like, Grignard reagent such as n-butylmagnesium chloride, methyl magnesium bromide or the like, alkaline earth metal amide or alkali metal amide such as lithium amide, sodium amide, lithium diisopropyl amide, magnesium diisopropyl amide, lithium hexamethyl disilazide, sodium hexamethyl disilazide, potassium hexamethyl disilazide or the like, alkali metal alkoxide such as sodium methoxide, sodium ethoxide, sodium-t-butoxide, lithium methoxide, lithium ethoxide, lithium-t-butoxide, potassium-t-butoxide or the like, alkaline earth metal hydride or alkali metal hydride such as lithium hydride, sodium hydride, potassium hydride, calcium hydride or the like, alkaline earth metal hydroxide or alkali metal hydroxide such as lithium hydroxide, sodium hydroxide, potassium hydroxide, cesium hydroxide, magnesium hydroxide, calcium hydroxide or the like, alkali metal carbonate such as lithium carbonate, sodium carbonate, potassium carbonate or the like, alkali metal bicarbonate such as lithium bicarbonate, sodium bicarbonate, potassium bicarbonate or the like, organic tertiary amine such as triethylamine, diisopropyl ethylamine, DBU (1,8-diazabicyclo[5,4,0]undecene) or the like.
[0096] In general an alkali metal hydroxide such as sodium hydroxide is the preferred.
[0097] The quantity of base used differs depending on species of base used, species of solvent and reaction conditions. In particular the reaction may be caused to proceed in high yield by using a 5-30 fold molar ratio, preferably 5-20 fold molar ratio with respect to compound represented by general formula (2).
[0098] In particular the concentration of the base in the reaction may be in the range of 5-30 wt %, more particularly in the range of 15-25 wt %.
[0099] In general a solvent is usually used in the reaction. Suitable solvents include, for example, water, dichloromethane, chloroform, dichloroethane, benzene, toluene, diethyl ether, methyl-t-butyl ether, tetrahydrofuran, 1,4,-dioxane, N,N-dimethylformamide, N-methylpyrrolidone, 1,3-dimethyl imidazolidinone, dimethylsulfoxide, acetone, acetonitrile, ethyl acetate, acetic acid-t-butyl, t-butanol and the like.
[0100] The solvent may be used alone or as a mixture. In the case of a mixture the proportion is not limited. In general, water is preferred.
[0101] Suitable reaction temperatures include those selected from the range of −30° C. to boiling point of solvent used and preferably it is selected from the range of 20° C.-60° C. The reaction time required is usually 30 minutes to 24 hours.
[0102] On completion of the reaction the solvent may be removed by distillation. The reaction mixture may be added to water or water to it, and then the mixture is acidified by addition of acid. The Compound (2) is transferred to the aqueous layer, and after having been caused to undergo liquid separation and washing with organic solvent such as toluene, ethyl acetate, isopropyl acetate, diethyl ether, dichloromethane, chloroform or the like, the aqueous layer is made basic using a base. The Compound of formula (2) is obtained using procedures such as extraction with an organic solvent such as toluene, ethyl acetate, isopropyl acetate, diethyl ether, dichloromethane, chloroform or the like, washing with water and concentration. Usually, on completion of the reaction, solvent is removed by distillation, and the compound of formula (2) may be obtained via procedures such as extraction with organic solvent such as toluene, ethyl acetate, isopropyl acetate, diethyl ether, dichloromethane, chloroform or the like, washing with water and concentration without the step of transfering to the aqueous layer. The compound (2) may be obtained in the form of a salt of an acid. The compound may be further purified by column chromatography, distillation or crystallisation, or it may be separated and purified in the form of a salt of an acid.
[0103] Suitable acids used after completion of the reaction include, for example, an organic carboxylic acid such as formic acid, acetic acid, propionic acid, trifluoroacetic acid, chloroacetic acid, dichloroacetic acid, trichloroacetic acid, oxalic acid, benzoic acid, phthalic acid, fumaric acid, mandelic acid or the like, optically active organic carboxylic acid such as tartaric acid, lactic acid, ascorbic acid, amino acid or the like, organic sulfonic acid such as methanesulfonic acid, trifluoromethanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, camphor sulfonic acid or the like, inorganic acid such as hydrochloric acid, sulphuric acid, nitric acid, phosphoric acid, carbonic acid. Hydrochloric acid or sulfuric acid are generally preferred.
[0104] Suitable bases used after completion of the reaction include, for example, an organolithium compound such as methyllithium, n-butyllithium, t-butyllithium, phenyl lithium or the like, Grignard reagent such as n-butylmagnesium chloride, methyl magnesium bromide or the like, alkaline earth metal amide or alkali metal amide such as lithium amide, sodium amide, lithium diisopropyl amide, magnesium diisopropyl amide, lithium hexamethyl disilazide, sodium hexamethyl disilazide, potassium hexamethyl disilazide or the like, alkali metal alkoxide such as sodium methoxide, sodium ethoxide, sodium-t-butoxide, lithium methoxide, lithium ethoxide, lithium-t-butoxide, potassium-t-butoxide or the like, alkaline earth metal hydride or alkali metal hydride such as lithium hydride, sodium hydride, potassium hydride, calcium hydride or the like, alkaline earth metal hydroxide or alkali metal hydroxide such as lithium hydroxide, sodium hydroxide, potassium hydroxide, cesium hydroxide, magnesium hydroxide, calcium hydroxide or the like, alkali carbonate metal salt such as lithium carbonate, sodium carbonate, potassium carbonate or the like, alkali metal bicarbonate such as lithium bicarbonate, sodium bicarbonate, potassium bicarbonate or the like, organic tertiary amine or the like such as triethylamine, diisopropyl ethylamine, DBU (1,8-diazabicyclo[5,4,0]undecene).
[0105] In general an alkali metal hydroxide, alkaline earth metal hydroxide, alkali carbonate metal salt, alkaline earth metal carbonate, alkali metal bicarbonate alkaline earth metal carbonate, organic tertiary amine are preferred.
[0106] Any of the embodiments described herein can be combined with any of the other embodiments described herein.
[0107] In order that the invention disclosed herein may be more efficiently understood, examples are provided below. It should be understood that these examples are for illustrative purposes only and are not to be construed as limiting the invention in any manner.
EXAMPLES
Example 1
Preparation of (2S)-2-(3,4-difluorophenyl)oxirane
[0108] A mixture of (1S)-2-chloro-1-(3,4-difluorophenyl)-1-ethanol (net 11.47 g, 59.5 mmol), toluene (25.23 g), sodium hydroxide (2.53 g, 1.06 molar equivalents) and water (24.25 g) was stirred and heated at 40° C. for 1 hour. The organic layer was separated, washed with water, and concentrated under reduced pressure. (2S)-2-(3,4-difluorophenyl)oxirane was obtained as resultant concentrate (net 8.94 g, yield: 96%).
[0109] 1 H-NMR in (400 MHz, CDCl3)
[0110] δ 2.71-2.73 (1H, dd, J=2.44 Hz, 5.37 Hz), 3.13-3.15 (1H, m), 3.82-3.83 (1H, m), 7.01-7.27 (4H, m).
Example 2
Preparation of ethyl (1R,2R)-2-(3,4-difluorophenyl)-1-cyclopropanecarboxylate
[0111] Sodium t-butoxide (32.22 g, 1.25 molar equivalents) and toluene (243.0 g) were charged into a reaction vessel. Triethyl phosphonoacetate (78.06 g, 1.04 molar equivalents to sodium t-butoxide) was added to the mixture with stirring. A toluene solution of (2S)-2-(3,4-difluorophenyl)oxirane (32.8 wt % solution, net 41.83 g, 267.9 mmol) was added drop-wise to the mixture keeping the internal temperature between 60 to 80° C. After completion of addition, stirring was continued for 11 hours at 80° C. After cooling to room temperature, the mixture was washed with water, and the organic layer was concentrated under reduced pressure. Ethyl (1R,2R)-2-(3,4-difluorophenyl)-1-cyclopropanecarboxylate was obtained as resultant concentrate (net 49.11 g, yield: 81%).
[0112] 1 H-NMR in (400 MHz, CDCl3)
[0113] δ 1.22-1.26 (1H, m), 1.26-1.30 (3H, t, J=7.1 Hz), 1.57-1.62 (1H, m), 1.82-1.87 (1H, m), 2.45-2.50 (1H, m), 4.14-4.20 (2H, q, J=7.1 Hz), 6.82-6.91 (2H, m), 7.02-7.09 (1H, m)
Example 3
Preparation of (1R,2R)-2-(3,4-difluorophenyl)-1-cyclopropanecarboxylic acid
[0114] Methanol (322.2 g) and 30% sodium hydroxide aqueous solution (65.5 g, 1.8 molar equivalents) were added to a solution of ethyl (1R,2R)-2-(3,4-difluorophenyl)-1-cyclopropanecarboxylate (48.2 wt % toluene solution, net 61.22 g, 270.6 mmol). The mixture was heated at 65° C. with stirring for 2 hours. The resultant mixture was concentrated under reduced pressure, then toluene and water were added to the concentrate. The mixture was acidified with 35% hydrochloric acid. The organic layer was separated and concentrated under reduced pressure. (1R,2R)-2-(3,4-difluorophenyl)-1-cyclopropanecarboxylic acid was obtained as resultant concentrate (net 52.55 g, yield: 98%).
[0115] 1 H-NMR in (400 MHz, CDCl3)
[0116] δ 1.33-1.38 (1H, m), 1.64-1.69 (1H, m), 1.83-1.88 (1H, m), 2.54-2.59 (1H, m), 6.83-6.93 (2H, m), 7.04-7.10 (1H, m).
Example 4
Preparation of (1R,2R)-2-(3,4-difluorophenyl)-1-cyclopropanecarboxamide
[0117] Thionyl chloride (72.65 g, 1.21 molar equivalents) was added to the stirred toluene solution of (1R,2R)-2-(3,4-difluorophenyl)-1-cyclopropanecarboxylic acid (18 wt %, net 100.00 g, 504.62 mmol). The mixture was stirred at 35° C. for 6 hours, then concentrated under reduced pressure to give a solution of (1R,2R)-2-(3,4-difluorophenyl)-1-cyclopropanecarbonyl chloride. To a mixture of 28% ammonia aqueous solution (122.55 g, 4.00 molar equivalents), water (300.4 g) and ethyl acetate (700.2 g), the solution of (1R,2R)-2-(3,4-difluorophenyl)-1-cyclopropanecarbonyl chloride obtained above was gradually added with stirring below 10° C. The reaction mixture was allowed to stir below 10° C. for 1 hour. The mixture was neutralized with 35% hydrochloric acid, then the organic layer was separated and washed with water. The resultant solution was concentrated azeotropically under reduced pressure to give a slurry of (1R,2R)-2-(3,4-difluorophenyl)-1-cyclopropanecarboxamide. The resultant slurry was heated to obtain a clear solution, and cooled for crystallization. Hexane was added to the slurry, then the precipitates were collected by filtration and dried to give (1R,2R)-2-(3,4-difluorophenyl)-1-cyclopropanecarboxamide (net 91.12 g, Yield: 92%).
[0118] 1 H-NMR in (400 MHz, CDCl3)
[0119] δ 1.21-1.27 (1H, m), 1.56-1.64 (3H, m), 2.47-2.49 (1H, m), 5.45 (1H, br), 5.63 (1H, br), 6.83-6.90 (2H, m), 7.03-7.10 (1H, m).
Example 5
Preparation of (1R,2S)-2-(3,4-difluorophenyl)-1-cyclopropanamine
[0120] (1R,2R)-2-(3,4-difluorophenyl)-1-cyclopropanecarboxamide(net 9.00 g, 45.64 mmol) and 30% sodium hydroxide aqueous solution (54.77 g, 9.00 molar equivalents) were charged into a reaction vessel and the mixture was stirred. Aqueous 12% sodium hypochlorite solution (29.53 g, 2.25 mol equivalents) was added to the stirred slurry maintaining the internal temperature at 30° C. The resultant mixture was stirred at 30° C. for 14 hours, then at 40° C. for 2 hours. After completion of the reaction, isopropyl acetate was poured to the resultant mixture, then the organic layer was separated, washed with water, and concentrated under reduced pressure. (1R,2S)-2-(3,4-difluorophenyl)-1-cyclopropanamine was obtained as resultant concentrate (net 6.89 g, yield: 89%).
[0121] 1 H-NMR in (400 MHz, CDCl3)
[0122] δ 0.88-0.93 (1H, m), 1.03-1.08 (1H, m), 1.70 (2H, s), 1.79-1.84 (1H, m), 2.47-2.51 (1H, m), 6.72-6.79 (2H, m), 7.00-7.02 (1H, m).
[0123] Various modifications of the invention, in addition to those described herein, will be apparent to those skilled in the art from the foregoing description. Such modifications are also intended to fall within the scope of the appended claims. Each reference (including, but not limited to, journal articles, U.S. and non-U.S. patents, patent application publications, international patent application publications, gene bank accession numbers, and the like) cited in the present application is incorporated herein by reference in its entirety. | This invention relates to processes for the production of optically active 2-(disubstituted aryl)cyclopropylamine compounds and optically active 2-(disubstituted aryl)cyclopropane carboxamide compounds which are useful intermediates for the preparation of pharmaceutical agents, and in particular the compound [1S-(1α,2α,3β(1S*,2R*),5β)]-3-[7-[2-(3,4-difluorophenyl)-cyclopropyl]amino]-5-(propylthio)-3H-1,2,3-triazolo[4,5-d]pyrimidin-3-yl)-5-(2-hydroxyethoxy)-cyclopentane-1,2-diol. | 2 |
BACKGROUND OF THE INVENTION
This invention is directed to a tent stake, and particularly a tent stake designed for easy installation and removal, together with secure tent rope attachment.
When tents are used, quite often tent ropes are necessary to maintain the tent in the upright, erected position. In addition, the corners of the tent floor must be staked down in order to provide tent stability. In some installations, tent stakes are only necessary around the tent floor; in those tents the structural design is such that the sides, and perhaps tent poles, perform all of the stability functions. It is more usual, however, that a tent require the securement of ropes to maintain the ridge line taut, or to stabilize the tent poles against swaying. When tent ropes must be secured, stakes are often employed. The desirable feature of tent stakes is that they be easily installed, secure for tent rope attachment, and easily removed. In addition, it is desirable that they be light in weight so that they do not unnecessarily add to the total structural weight which must be transported when the tent is moved.
Thus, there is need for an improved tent stake design which meets these criteria.
SUMMARY OF THE DISCLOSURE
In order to aid in the understanding of this invention it can be stated in essentially summary form that it is directed to a tent stake which is formed of a single length of wire-like material. The shank of the stake is formed of a straight section of the wire and the head is formed by bending the wire to present a driving surface in line with the shank, and to form a hook and an open handle, respectively, for tent rope engagement and tent stake removal. Below the hook, the bent end of the wire is preferably secured to the shank.
It is thus an object of this invention to provide a tent stake which is of economical manufacture and convenient use, so that it can be widely and easily used. It is a further object to provide a tent stake made of a single length of wire-like material having a straight shank and a bent head thereon, with the head being for driving of the tent stake, tent rope attachment and tent stake withdrawal.
The features of the present invention which are believed to be novel are set forth with particularity in the appended claims. The present invention, both as to its organization and manner of operation, together with further objects and advantages thereof, may best be understood by reference to the following description, taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an end elevational view of a tent, showing the manner in which the tent stake of this invention is employed to support and stabilize the tent.
FIG. 2 is an enlarged view showing the tent stake of this invention, in its first preferred embodiment, as installed, with parts broken away.
FIG. 3 is a side elevational view of the tent stake of FIG. 2.
FIG. 4 is a side elevational view of the second preferred embodiment of the tent stake of this invention, with the shank thereof broken away.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Tent 10 has a floor 12 on the ground 14 and has peak 16 supported above the ground by poles. Tent sides 18 and 20 stabilize the peak as long as the floor is well secured. Tent stakes 22 and 24 are positioned through rings secured to the edges of the floor fabric to stretch out the floor 12 and secure it to the ground. Some tents are secured in this way. Other tents have tent ropes 26 and 28 attached to the peak and extending either along the length of the peak to keep it taut, or at an angle thereto to stabilize the position of peak 16, or both. The tent ropes must be secured to the ground, and tent stakes 30 and 32 are employed for that purpose. When the tent stakes 30 and 32 are secured in the ground, the tent ropes are engaged thereon and tightened in the usual way. Tent stakes 30 and 32 are of identical construction. Tent stakes 22 and 24 are also of identical construction and may be identical to the tent stake 30, being of the same size or possibly a slightly smaller size, as indicated in FIG. 1. Aside from the size, the remainder of the configuration of tent stake 22 is the same as tent stake 30.
Tent stake 30 is shown in more detail in FIGS. 2 and 3. Tent stake 30 is made of a single piece of wire-like material, preferably circular in cross-section, so that the wire is a solid cylinder. Steel is a suitable material for the wire which forms the body of the tent stake. In this sense, the body is the entire length of the wire including the shank 34 of tent stake 30 and the head 36. The shank is straight and extends from the tip 38 to the striking corner 40 of the head. Striking corner 40 is in line with the straight shank 34 and the bend at striking corner 40 is preferably slightly greater than 90°, as shown in FIGS. 2 and 3. From the bend at striking corner 40 the top 42 extends away from the center line of the straight shank 34. Downward leg 44 is directed at an acute angle with respect to straight shank 34 and is directed away from the straight shank in a downward direction. At the lower end of downward leg 44, hook bend 46 directs the body upward in hook leg 48, which is directed at an acute angle with respect to the center axis of straight shank 34. The hook leg 48 is acute in the same direction as downward leg 44. Final bend 50 directs the final leg 52 parallel to and in contact with the upper portion of straight shank 34. The final leg 52 may be attached to the shank 34 by any appropriate means, such as spot welding.
Another preferred embodiment of the tent stake of this invention is generally indicated at 60 in FIG. 4. The tent stake 60 has the same characteristics, including a body which is of wire-like material. The body includes straight shank 62 which is shown broken off in FIG. 4. Its length is actually the same proportionate length as is shown in FIG. 3. Head 64 of the tent stake is formed by bending the upper end of the body above straight shank 62. In tent stake 60, the head starts at bend 66 to form an offset leg 68 which is at an acute angle with respect to the upward extension of the actual center line of the straight shank 62. Top 70 and downward leg 72 are both angularly oriented with respect to the axial center line. Hook bend 74 directs hook leg 76 at an acute angle with respect to the center line of straight leg 62, while final bend 78 brings final leg 80 down next to straight shank 62 to which it is preferably fastened, as by spot welding. Opening 82 in head 64 permits access by the user's fingers. Like stake 30, stake 60 has all of its bends and legs lying in a single plane. The stake 60 is easier to use in lighter soils because it is easy to manually engage and thrust into such lighter soil.
The body of tent stake 30 is sufficiently stiff that in use it can be driven into the ground. The tent stake is aligned in the position where it is to be driven and a driving force is applied to striking corner 40. If the soil is light, such as sand or sandy loam, quite often the tent stake 30 can be installed simply by hand force on the top 42, with the hand force principally aligned and with shank 34 by applying the hand force at striking corner 40. The manual effort will be enough to install the stake 30 in light soil, particularly because of the thinness of shank 34, which need not displace much soil upon its entry. Even in light soil, the stake 30 can hold a substantial force, particularly when the tent stake 30 is installed with its shank axis approximately at right angles to the force which is expected to be applied. If necessary, particularly in heavier soils, the driving force applied to striking corner 40 may be applied with a hammer, axe, rock, or a block of wood, depending upon the available tools. In that case, the stake 30 may be used in heavier soils.
Stakes 22 and 24 may be the same in size as stake 30 or may be of a smaller size, with the same proportions. Stakes 22 and 24 are driven into the rings at the edges of the tent floor. Stakes 30 and 32 are driven into the soil at the selected locations and orientations, and thereafter the tent ropes 26 and 28 are tied thereto, respectively. The tent ropes are engaged within the hook of the tent stake and appropriately tied, usually back to themselves. In this way, the tent is secured.
When the tent is being taken down, the tent stakes must be removed. The opening 54 in the head 36 is large enough to accept at least several fingers of the user's hand. The user then pulls the tent stake out of the soil by applying manual force to the head by finger engagement in opening 54, with the withdrawal force being directed axially of shank 34. Thus, the tent stake 30, and its companions can be readily withdrawn. Accordingly, the tent stake 30 and its companions are inexpensive to manufacture, are light weight for easy transportation, and yet have a strong head 36 for the driving, the tying to and the withdrawal of stake 30.
This invention has been described in its presently contemplated best mode, and it is clear that it is susceptible to numerous modifications, modes, and embodiments within the ability of those skilled in the art and without the exercise of the inventive faculty. Accordingly, the scope of this invention is defined by the scope of the following claims. | Tent stake has a straight wire shank and has a head formed of the same material. The head has a hook under the side thereof for engagement by a tent rope, has a driving surface on the top thereof, and has an opening therethrough to serve as a handle for the pulling of the tent stake. | 4 |
TECHNICAL FIELD
The present invention relates generally to fan clutch assemblies and more particularly to methods and systems for improving the operation of airactuated cone clutch fan assemblies.
BACKGROUND OF THE INVENTION
Vehicle engines commonly utilize cooling assemblies to remove excess heat from the engine and maintain an optimal operating temperature. The cooling assembly pumps a coolant through the engine and other components in order to control engine temperature. Heat generated within the engine and other components is absorbed by the coolant and dispersed into the surrounding atmosphere through the use of a radiator. In order to improve dispersal by the radiator, it is common to utilize fan assemblies to draw or force air past the radiator to assist in temperature transmission.
It is not always desirable for such fan assemblies to be run continuously. At times, it is desirable for the temperature within the coolant to increase rather than decrease. Additionally, continuous operation when unnecessary places an non-required draw on the engine and thereby reduces efficiency. To compensate for this, present fan assemblies utilize fan clutch assemblies that allow for the selective engagement of the fan to the engine such that the fans are engaged only when necessary. The fan clutch assemblies may be operated in a plurality of configurations including hydraulic and air-pressure actuated. It is common for these systems to be biased towards fan operation such that when failure occurs in the clutch assembly, the fan continuously operates to keep the engine cool.
Airactuated friction clutch assemblies of this type which work well for their intended purpose are found in U.S. Pat. Nos. 7,731,006, 7,055,668, and 7,430,956.
An issue with airactuated fan clutch assemblies relates to situations where the air pressure is too low to adequately cause actuation of the fan drive. This could result, for example, from a leak in the air supply, or a drain of pressure due to constant repeated usage. Without sufficient pneumatic pressure, the friction clutch might not engage solidly causing possible overheating and damage to the friction assembly and clutch.
It would therefore be desirable to have pneumatic clutch fan assembly with a system for protecting the fan assembly by preventing engagement of the friction clutch when a low pressure situation exists.
It would also be desirable to provide a clutch assembly with a pneumatic control mechanism that would prevent slip damage due to low, external operating air pressure.
It would further be desirable for such a clutch assembly to provide optimal performance and operation at all times during operation.
SUMMARY OF THE INVENTION
In one form, the present teachings provide an air-actuated fan clutch that includes a drive shaft, a clutch element, a friction liner, a clutch housing, a clutch spring, a piston, a first directional valve and an actuator. The drive shaft is rotatable about an axis. The clutch element is coupled to the drive shaft for rotation therewith. The friction liner is disposed about the clutch element. The clutch housing is rotatable relative to the drive shaft about the axis and is movable relative to the clutch element along the axis between a first position, in which the clutch element, the friction liner and the clutch housing cooperate to permit transmission of rotary power between the clutch element and the clutch housing, and a second position in which transmission of rotary power between the clutch element and the clutch housing is inhibited. The clutch spring biases the clutch housing toward the first position. The piston is movable along the axis between a piston neutral position and a piston activated position. Movement of the piston from the piston neutral position to the piston activated position causes corresponding movement of the clutch housing into the second position. Movement of the piston from the piston activated position to the piston neutral position causes corresponding movement of the clutch housing into the first position. The first directional valve has a first port, a second port and a first valve element. The first port is configured to be coupled to a source of fluid pressure. The second port is coupled in fluid communication with the piston. The first valve element is movable between a first element position, in which the first and second ports are not in fluid communication with one another, and a second element position in which the first and second ports are in communication with one another. The actuator is coupled to the first directional valve and configured to be coupled to the source of fluid pressure. The actuator provides at least one output that is configured to move the valve element of the first directional valve. The at least one output is at least partly based on a magnitude of a fluid pressure acting on the actuator and is produced when the magnitude is greater than or equal to a predetermined fluid pressure.
In another form, the present teachings provide a method of operating an air-actuated fan clutch. The fan clutch includes a piston, a clutch housing, a clutch element and a clutch spring. The piston is movable under fluid pressure to cause corresponding relative movement between the clutch housing and the clutch element such that rotary power is transmit-able between the clutch element and the clutch housing. The clutch spring biases the clutch housing away from the clutch element. The method includes: providing a first directional valve having a first valve element that is movable between a closed position and an open position, the first valve element being biased into the closed position; providing fluid pressure to a first directional valve while the first valve element is in the closed position; and moving the first valve element from the closed position to the open position to transmit fluid pressure to the piston to disengage the fan clutch in response to determining that a magnitude of the fluid pressure is greater than or equal to a predetermined value.
Other objects and features of the present invention will become apparent when viewed in light of the detailed description and preferred embodiment when taken in conjunction with the attached drawings and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a representative vehicle utilizing a fluidically controlled fan drive system.
FIG. 2 depicts a quarter side cross-sectional view of a friction cone clutch assembly.
FIG. 3 depicts a preferred embodiment of an electro-pneumatic 3-way control system in accordance with the present invention.
FIG. 4 depicts an alternate electronic pneumatic control system.
FIG. 5 depicts another alternate embodiment of the invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
While the present invention is described primarily with respect to a system for a pneumatically controlled fan drive system, the present invention may be adapted and applied to various systems including: hydraulic systems, pneudraulic systems, mechanical systems, pneumatic systems, vehicle systems, cooling systems, fan drive systems, friction drive systems, or other systems.
In the following description, various operating parameters and components are described for preferred embodiments. These specific parameters and components are included only by way of example and are not meant to be limiting the invention to the described embodiment or systems having its particular structure or operational parameters.
Also, in the following description, various fan drive components and assemblies are described as an illustrative example. The fan drive components and assemblies may be modified depending upon the application.
Although the present invention may be used advantageously in various configurations and applications, it is especially advantageous in a coupling device of the type used to drive a radiator cooling fan of an internal combustion engine for an over-the-road truck.
Referring now to FIG. 1 , a perspective view of a representative vehicle 10 utilizing a representative fluidically controlled fan drive system 12 which can incorporate an embodiment of the present invention. The system 12 uses rotational energy from a liquid cooled engine 14 at an increased ratio to turn a radiator cooling fan 16 to provide airflow through a radiator 18 . The system 12 includes a friction clutch assembly 20 that is fixed to one or more pulleys, such as pulley 22 , which is coupled to and rotates relative to a crankshaft (not shown) of the engine 14 . The pulleys rotate via a pair of belts 24 , within an engine compartment 25 . Of course, the present invention may be relatively operative in relation to various components and via any number of belts or other coupling devices, such as a timing chain. The friction clutch assembly 20 is mounted on the engine 14 via a mounting bracket 26 . The friction clutch assembly 20 pneumatically engages the fan 16 during desired cooling intervals to reduce the temperature of the engine 14 .
The fan 16 may be attached to the friction clutch assembly 20 by any suitable means, such as is generally well known in the art. It should be understood, however, that the use of the present invention is not limited to any particular configuration of the system 12 , or fan mounting arrangement, or any particular application for the system 12 .
Referring now to FIG. 2 , a quarter side cross-sectional view of the friction clutch assembly 20 is shown. The assembly 20 includes a translatable clutch housing 30 and a rotating shaft 32 . The clutch housing 30 is attached to an engine cooling fan, such as fan 16 . The rotating shaft 32 is coupled to a drive pulley, such as pulley 22 . A friction liner 34 is coupled to the clutch housing 30 and resides between the clutch housing 30 and the rotating shaft 32 . A clutch spring 35 engages the clutch housing 30 with the rotating shaft 32 . The clutch spring 35 resides on spring carriers or retainers 36 , within a clutch spring area 38 , and within the shaft 32 .
In operation, air, as represented by arrows 39 , is forced in and out of the spring area 38 , through the passages 46 through a piston rod bearing groove 47 , through a rear cavity 49 , through a shaft channel 51 , and into the housing cavity 53 .
The friction clutch assembly 20 also includes a fluidic control circuit that is operated via a main controller 50 . The fluidic control circuit includes a piston rod or pneumatic transfer conduit 54 with a fluid channel 56 residing therein for the transfer of fluid, such as air, into a piston reservoir 58 of an air cylinder 59 . The air cylinder 59 resides over a piston 61 . A fluid pump 60 and corresponding solenoid 57 are fluidically coupled to the fluid channel 56 . The main controller 50 is coupled to the pump 60 and to the solenoid 57 and adjusts the flow of the fluid into and out of the reservoir 58 . The solenoid may be replaced with other types of valves known in the art.
When air pressure is supplied, the reservoir 58 becomes pressurized and the clutch piston member 61 is moved into a piston activated position. In this position, the translatable clutch piston member 61 moves the clutch housing 30 relative to the cone clutch element 28 into a clutch disengaged position. (This position is shown in FIG. 2 .) When in the clutch disengaged position, the clutch housing 30 is disengaged from the cone clutch element 28 and the rotating drive shaft 32 such that the clutch housing 30 is independently rotatable relative to the clutch element 28 and the rotating drive shaft 32 .
The clutch spring member 35 is positioned within the clutch housing 30 and biases the clutch housing 30 relative to the cone clutch element 28 into a clutch engaged position. When pressure within the pressure chamber is released, the clutch spring 35 moves the clutch housing 30 relative to the cone clutch element 28 into the clutch engaged position and the translatable clutch piston 61 moves into the piston neutral position. The clutch spring 35 also provides a maximum spring force which in turn translates into a clutch engagement force between the clutch housing 30 and the cone clutch element 28 . This force prevents slippage between the clutch housing 30 and the cone clutch element 28 .
The main controller 50 may be contained within the system 12 or may be separate from the system 12 as shown. The main controller 50 may be microprocessor based, such as a computer having a central processing unit, memory (RAM and/or ROM), and associated input and output buses. The main controller 50 may also be a portion of a central vehicle main control unit, an interactive vehicle dynamics module, a cooling system controller, or may be a stand-alone controller as shown.
In operation, the friction clutch assembly 20 is frequently engaged. When engaged, no fluid is pumped into the reservoir 58 . In such situations, the piston 61 is in the piston neutral position, the clutch housing 30 is in the clutch engaged position (relative to the clutch element 28 ) and the spring 35 is in an expanded state. When cooling is no longer desired, the main controller 50 pumps fluid into the reservoir 58 , which causes the piston 61 to shift rearward, towards the shaft 32 . As the piston 61 shifts rearward, the housing 30 also shifts rearward, thereby compressing the spring 35 and causing the friction liner 34 and thus the clutch housing 30 to disengage from the clutch element 28 . As the spring 35 compresses, the volume of the spring retainer area 38 decreases, which forces air within the spring retainer area 38 to pass through the passages 46 .
The present invention creates new airactuated controls that add the feature of preventing exposure to low air pressure that could allow slipping damage to the clutch during disengaged operation. For this purpose, an anti-slip valve mechanism 75 is provided.
A first embodiment of a system for preventing the friction clutch from slipping and from possibly becoming damaged if the pneumatic pressure in the vehicle is too low, is shown in FIG. 3 . This system 100 is an electro-pneumatic system which is solenoid based with additive electrical and pneumatic pilot signals operating on a three-way valve biased by a spring. The valve is essentially an on-off valve and is calibrated such that it will not allow air to flow to the friction clutch mechanism until it exceeds a certain value.
In order to prevent burn out of the valve, i.e. overheating and damage, particularly at high differential speeds, the system 100 is calibrated to not allow the passage of air until the air pressure is at least 60 psi and preferably at least 80 psi.
From the compressor or air pump 60 , the pressurized air flows to pilot valve 57 . The main controller 50 is programmed with the logic for operating all of the various systems in the vehicle. In this instance, the electric solenoid pilot valve 125 is an on-off valve which only is actuated when the main controller 50 determines that cooling is not needed. When opened, air can pass through it to valve 130 .
When the valve 57 is opened, the air flows to the second valve 130 which is operated by a pneumatic pilot 135 . Valve 130 is only opened when the air pressure exceeds a certain critical value, such as, for example, 60 psi. The biasing force from spring member 140 prevents the valve 130 from operating until the pilot vehicle air pressure reaches the preset value.
Once the minimum air pressure is reached, the valve 130 is opened allowing the pneumatic pressure to flow to the friction clutch mechanism 20 and operate it as set forth above. As evident from FIG. 3 , both valves 57 and 130 need to be energized in order to provide air pressure to flow to the clutch mechanism 20 .
The main controller or “Electronic Control Unit” (“ECU”) for the vehicle is coupled both to the solenoid valve 57 and the pump 60 .
FIG. 4 depicts an alternate embodiment 150 of the invention. In this embodiment, air supplied from the compressor pump 60 flows to a pneumatic valve 155 which operates a pilot for the on-off valve 160 . The ECU 50 controls the solenoid valve 165 which is an electric pilot. The valve 160 is biased by spring member 140 . Both the electric pilot and pneumatic pilot signals are required to provide air pressure to flow to the clutch mechanism 20 .
When the air pressure through pneumatic pilot valve 155 exceeds the minimum value, such as, for example, 60 psi, and the solenoid valve 165 is energized, the air pressure is allowed to flow to and operate the friction clutch assembly 20 .
In FIG. 4 , the electrical-pneumatic pilot solenoid valve in the vehicle is modified to add the air pilot feature. The connection of the air line to the valve pilot is internal to the valve. This addition insures that the friction clutch would not be subjected to air pressure at such a low pressure that it would result in slippage of the friction liner. In order for the valve to allow air pressure to the clutch, both the signal from the ECU and sufficient air pressure is needed.
The operation of the system to prevent damage to the friction liner can be carried out by types of valves other than electro-pneumatic valves. As shown in system 200 depicted in FIG. 5 , a pressure switch 210 is utilized to prevent low pressure slippage in the friction clutch assembly.
The pressure switch 210 closes at the critical pressure level, such as 60 psi or 80 psi, and allows the electrical signal from the controller to pass through to valve 220 (or solenoid vale 230 ). The valve 220 is an on-off valve and opens to allow or pressure to flow to, and operate, friction clutch assembly 10 . The valve 220 has a biasing spring 225 and an electrical solenoid valve 230 .
In FIG. 5 , the pressure control switch is in series with the air control solenoid valve. The pressure switch 210 monitors the air pressure in the vehicle. This system 200 assures that the friction clutch 20 would not be subjected to a low air pressure that would result in liner slippage. In order for the valve 200 to allow any air pressure to the clutch, both the signal from the ECU and sufficient air pressure would be needed.
While the invention has been described in connection with one or more embodiments, it is to be understood that the specific mechanisms and techniques which have been described are merely illustrative of the principles of the invention, numerous modifications may be made to the methods and apparatus described without departing from the spirit and scope of the invention as defined by the appended claims. | An air-actuated fan clutch having a translatable piston in communication with a pressure chamber and moveable between a piston neutral position and a piston activated position in response to air pressure. A clutch spring biases a clutch housing into engagement with a clutch element that is coupled for rotation with a drive shaft when the piston is in the piston neutral position. Movement of the piston to the piston activated position moves the clutch housing away from the clutch element to inhibit transmission of rotary power through the fan clutch. A valve and an actuator are provided to prevent movement of the piston from the piston neutral position when air pressure acting on the piston would be below a predetermined threshold. | 5 |
FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable.
REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER LISTING APPENDIX
Not applicable.
COPYRIGHT NOTICE
A portion of the disclosure of this patent document contains material that is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or patent disclosure as it appears in the Patent and Trademark Office, patent file or records, but otherwise reserves all copyright rights whatsoever.
FIELD OF THE INVENTION
The present invention relates generally to solar lighting. More particularly, the invention relates to a solar window nightlight that includes a power source and projection lenses.
BACKGROUND OF THE INVENTION
There are several types of currently known nightlights that are typically plugged into a wall outlet. As these nightlights are usually plugged in, they constantly draw from the power grid. Therefore a nightlight that does not need to be plugged into a wall outlet is desirable. Other desirable features for a nightlight include without limitation, enabling the user to direct the light from the nightlight, providing decorative features, and providing various controls to the user such as, but not limited to, brightness control, color control, and speed of lighting.
In view of the foregoing, there is a need for improved techniques for providing nightlights may be powered without being plugged into a wall socket.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings and in which like reference numerals refer to similar elements and in which:
FIGS. 1A , 1 B, 1 C, and 1 D illustrate an exemplary solar window nightlight, in accordance with an embodiment of the present invention. FIG. 1A is a front perspective view; FIG. 1B is a rear perspective view; FIG. 1C is a side view, and FIG. 1D is a front perspective view of a lens separated from a circuit housing;
FIGS. 2A , 2 B and 2 C illustrate an exemplary nightlight where all of the components are built into a specific design, in accordance with an embodiment of the present invention. FIG. 2A is a rear view; FIG. 2B is a front view, and FIG. 2C is a front exploded view; and
FIGS. 3A , 3 B, 3 C, and 3 D illustrate an exemplary nightlight with a multi-part design, in accordance with an embodiment of the present invention. FIG. 3A is a rear view; FIG. 3B is a front view; FIG. 3C is a side view, and FIG. 3D is a bottom view.
Unless otherwise indicated illustrations in the figures are not necessarily drawn to scale.
SUMMARY OF THE INVENTION
To achieve the forgoing and other objects and in accordance with the purpose of the invention, an apparatus for a solar window nightlight is presented.
In one embodiment, an apparatus for a solar window nightlight is presented. The apparatus includes a circuit housing. At least one battery is contained within the circuit housing. A plurality of solar panels are disposed on an outside surface of the circuit housing for charging the at least one battery. A plurality of LED lights are included. Control circuitry connects the at least one battery, the solar panels and the plurality of LED lights to control operations of the LED lights and charging of the at least one battery. A photocell is operative to detect ambient light. The photocell is connected to the control circuitry where when ambient light falls below a predetermined level, the control circuitry activates the plurality of LED lights. A plurality of translucent lenses each includes a generally wedge shape, a bore hole in a base of the wedge shape for receiving a one of the plurality of LED lights and reflective material on outside edges of the wedge shape to direct and contain light. A plurality of suction cups joined to at least the circuit housing retains the apparatus on a window surface where, during day light hours, there is sufficient ambient light to charge the at least one battery and the plurality of translucent lenses capture and reflect sunlight, and, during night hours, the translucent lenses illuminate a desired area.
In another embodiment an apparatus for a solar window nightlight is presented. The apparatus includes means for housing at least one battery and control circuitry, means for charging the at least one battery, means for producing light from the at least one battery, means for detecting a level of ambient light to activate the light producing means, means for lensing light from the light producing means and means for joining the apparatus to a window surface.
In another embodiment an apparatus for a solar window nightlight is presented. The apparatus includes a circuit housing. At least one battery is contained within the circuit housing. At least one solar panel is disposed on an outside surface of the circuit housing for charging the at least one battery. At least one light is included. Control circuitry connects the at least one battery, the at least one solar panel and the at least one light to control operations of the at least one light and charging of the at least one battery. A photocell is operative to detect ambient light. The photocell is connected to the control circuitry where when ambient light falls below a predetermined level, the control circuitry activates the at least one light. At least one translucent lens includes a bore hole for receiving the at least one light. Means retains the apparatus on a generally flat vertical surface where, during day light hours, there is sufficient ambient light to charge the at least one battery, and, during night hours, the translucent lens illuminates a desired area.
Other features, advantages, and object of the present invention will become more apparent and be more readily understood from the following detailed description, which should be read in conjunction with the accompanying drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention is best understood by reference to the detailed figures and description set forth herein.
Embodiments of the invention are discussed below with reference to the Figures. However, those skilled in the art will readily appreciate that the detailed description given herein with respect to these figures is for explanatory purposes as the invention extends beyond these limited embodiments. For example, it should be appreciated that those skilled in the art will, in light of the teachings of the present invention, recognize a multiplicity of alternate and suitable approaches, depending upon the needs of the particular application, to implement the functionality of any given detail described herein, beyond the particular implementation choices in the following embodiments described and shown. That is, there are numerous modifications and variations of the invention that are too numerous to be listed but that all fit within the scope of the invention. Also, singular words should be read as plural and vice versa and masculine as feminine and vice versa, where appropriate, and alternative embodiments do not necessarily imply that the two are mutually exclusive.
The present invention will now be described in detail with reference to embodiments thereof as illustrated in the accompanying drawings.
Preferred embodiments of the present invention provide a solar window nightlight that comprises a power source and projection lenses. Preferred embodiments use solar energy collected during the day to power the nightlight at night thus generally eliminating the need to constantly draw from the power grid. Some preferred embodiments may include a flexible conduit that separates the circuit housing from the projection lenses that enables the user to position the illuminated area. For example, without limitation, separating the two main components enables the user to thread the projection lenses through blinds or shutters and to select the exact position and direction of the lighting. Preferred embodiments may incorporate various types of designs such as, but not limited to, fish, animals, insects, flowers, machinery, letters, numbers, symbols, licensed material, etc. In addition, preferred embodiments may be used during the day to reflect light through translucent lenses like a sun catcher. In addition, preferred embodiments provide additional controls to the user such as, but not limited to, brightness control, color control, and speed of lighting.
One preferred embodiment of the present invention is an all-encompassed translucent print design that can be attached to a projection lens, as shown by way of example in FIGS. 1A through 1D . Another preferred embodiment is an all-encompassing inclusive design that has a decorative shape such as, but not limited to, a flower, an insect, an animal, machinery, a letter, a numeric, a symbol, a licensed design, etc., as shown by way of example in FIGS. 2A through 2C . Yet another preferred embodiment is a multi-component design that enables the user to position the illuminated components (i.e., the projection lenses) independently from the circuit housing via a flexible conduit, as shown by way of example in FIGS. 3A through 3D . In addition, multiple units of the same or different designs may be mixed and matched to make a larger picture or design. For example, without limitation, a spider may be created as a Halloween window night light decoration by taking one encompassed-inclusive design for the body and adding multiple multi-component designs for legs, etc.
Preferred embodiments are typically used by affixing the nightlight to a window via suction cups where the light captures sunlight during the day charging the internal batteries and reflecting light through translucent lenses. Once it becomes dark, the nightlight automatically activates the lighting source illuminating the desired area.
FIGS. 1A , 1 B, 1 C, and 1 D illustrate an exemplary solar window nightlight, in accordance with an embodiment of the present invention. FIG. 1A is a front perspective view; FIG. 1B is a rear perspective view; FIG. 1C is a side view, and FIG. 1D is a front perspective view of a lens 1 a separated from a circuit housing 2 . In the present embodiment, the solar window nightlight comprises projection lens l a that is a translucent material such as, but not limited to, resin, plastic, or glass, which may have various shapes. Projection lens 1 a is a wedge shape to provide more controlled lighting over a projection lens 1 b that is rectangular in shape. Those skilled in the art, in light of the present teachings, will readily recognize that projection lenses in alternate embodiments may be various different shapes such as, but not limited to, circles, spheres, cubes, decorative shapes, etc. Both lenses 1 a and 1 b may be used as a sun capture to reflect light during the day. Projection lenses 1 a and 1 b can be solid material or hollow material depending on the light distribution desired. In the present embodiment, projection lens 1 a is connected to circuit housing 2 that houses a rechargeable battery 3 and internal solar and lighting circuitry 4 . Internal circuitry 4 is protected by a housing cap 5 that is secured to housing 2 with screws 6 . The solar window nightlight also comprises suction cups 7 , which are connected to projection lens 1 a or 1 b through holes 8 .
Referring to FIG. 1B , the rear view of the solar window nightlight illustrates a photocell 10 and solar collection panels 12 on circuit housing 2 . In the present embodiment, reflective tape 13 covers the outside edges of projection lens 1 a to help direct and contain light; however, in alternate embodiments some solar window nightlights that do not need help directing and containing light do not include reflective tape on the projection lens. The solar window nightlight has the option to print designs on a transparent film 14 and use adhesive to apply film 14 to projection lens 1 a . For additional support when attached to a surface, circuit housing 2 comprises an extra suction cup connection 15 . Referring to FIG. 1C , a suction cup 16 is shown attached to suction cup connection 15 . Referring to FIG. 1D , circuit housing 2 comprises LED light sources 21 that are powered by the solar collection circuitry, and projection lens 1 a comprises bored LED inserts 22 into which LED light sources 21 are inserted when projection lens 1 a is connected to circuit housing 2 . LED light sources may be single or multiple colors and may be able to flash, alternate colors, or sparkle. In an alternate embodiment, the nightlight may comprise an additional cover to house a traditional incandescent light bulb.
In typical use of the present embodiment, the solar window nightlight is secured to a window with suction cups 7 and 16 . Photocell 10 and solar collection panels 12 lie flat on the glass of the window charging rechargeable battery 3 any time there is light. In addition, projection lens 1 a acts as a sun capture to reflect light during this time. Once it becomes dark, photocell 10 activates the LED light sources 21 . If a design film 14 is attached to projection lens 1 a , this design is now projected from projection lens 1 a by LED light sources 21 . In an alternate embodiment, the solar collection panels may be located on the front of the circuit housing so that the nightlight may be attached to a surface other than a window such as, but not limited to, a mirror, a wall, a piece of furniture, etc. and still collect light.
FIGS. 2A , 2 B and 2 C illustrate an exemplary nightlight where all of the components are built into a specific design, in accordance with an embodiment of the present invention. FIG. 2A is a rear view; FIG. 2B is a front view, and FIG. 2C is a front exploded view. In the present embodiment, the nightlight is in the design of a flower; however, alternate embodiments may be various different designs such as, but not limited to, cars, stars, fish, animals, licensed designs, etc. Referring to FIG. 2A , the back of the encompassed design is shown exposing solar collection panels 31 that lie flat on a window during use. Referring to FIG. 2B , the front of the encompassed design is shown illustrating petals 40 and a flower center 41 , which act as projection lenses that illuminate once a photocell 47 , is activated. The encompassed design is secured to a window by a suction cup 42 that is attached to a petal projection lens 40 through a hole 43 and suction cups 44 that are attached to decorative leaves 45 through holes 46 .
Referring to FIG. 2C , the internal components of the encompassed design are illustrated. Petal projection lenses 40 each comprise a bored out hole 50 into which LED lights 51 are inserted. LED lights 51 can be single or multiple colors and may also be able to flash, alternate colors or sparkle. Inside a circuit housing 61 is lighting and solar collection circuitry 52 , an additional LED light 53 that is threaded through a cutout 56 of a circuit-housing cap 55 , and a power source 54 , which is a rechargeable battery in the present embodiment. Circuit-housing cap 55 covers circuit housing 61 to protect and conceal internal circuitry 52 and is secured in place using screws threaded through secure points 57 . In the present embodiment, circuit-housing cap 55 comprises cutouts 58 to secure a translucent lens 59 utilizing fittings 60 that thread though cutouts 58 .
In typical use of the present embodiment, the nightlight is secured to a window using suction cups 42 and 44 with solar collection panels 31 facing the outside. Solar collection panels 31 lie flat on the glass of the window charging power source 54 any time there is light. In addition, petal projection lenses 40 act as sun captures to reflect light during this time. Once it becomes dark, the photocell activates LED light sources 51 and 53 to illuminate petals 40 and flower center 41 . In an alternate embodiment, the solar collection panels may be located on the front of the circuit housing so that the nightlight may be attached to a surface other than a window such as, but not limited to, a mirror, a wall, a piece of furniture, etc. and still collect light.
FIGS. 3A , 3 B, 3 C, and 3 D illustrate an exemplary nightlight with a multi-part design, in accordance with an embodiment of the present invention. FIG. 3A is a rear view; FIG. 3B is a front view; FIG. 3C is a side view, and FIG. 3D is a bottom view. In the present embodiment, the nightlight is in the design of a flower; however, alternate embodiments may be various different designs such as, but not limited to, other plants, animals, insects, licensed designs, etc. In the present embodiment the nightlight comprises a circuit housing 70 , a flexible conduit 64 , and a projection lens assembly 72 . In the present embodiment, projection lenses 73 are not part of circuit housing 70 . Instead, wiring 65 from a power source 67 is housed in flexible conduit 64 , which enables a user to position projection lens assembly 72 while maintaining the shaped integrity of flexible conduit 64 . In the present embodiment, flexible conduit 64 is made of plastic that enables flexible conduit 64 to be shaped, bent and adjusted to direct the light of the nightlight; however, in alternate embodiments other materials may be used for the conduit, such as, but not limited to, a rubber hose that encases a metal wire.
Referring to FIG. 3A , the rear of the nightlight comprises solar collection panels 71 and suction cups 68 , which fit into suction cup holes 69 in circuit housing 70 . Referring to FIG. 3B , projection lenses 73 are connected to an additional lighting source 62 and comprise bored out holes 74 into which LED lights 63 are inserted. In the present embodiment, the same circuitry in the previously described embodiments is housed in circuit housing 70 including, but not limited to, lighting and solar collection circuitry 66 and power source 67 . Referring to FIG. 3C , the side view of the nightlight illustrates that flexible conduit 64 can be bent to position projection lens assembly 72 . A photocell 75 on circuit housing 70 measures the amount of ambient light present. Referring to FIG. 3D a brightness dial 73 that controls the brightness of LED lights 63 and a speed control 74 that controls the speed of the rotation of LED lights 63 from slow sparkle to solid lights and everywhere in between are located on the bottom of circuit housing 70 . Other controls that may be included in alternate embodiments include without limitation, a color rotation control when multiple color LED lights are included, a timer, or controls for effects such as, but not limited to, strobe, flash, sparkle, fade and on/off switch. LED lights 63 may be single or multiple colors and may also be able to flash, alternate colors or sparkle.
In typical use of the present embodiment, the nightlight is secured to a window using suctions cups 68 that are attached to circuit housing 70 with solar collection panels 71 lying flat against the window. Flexible conduit 64 can then be bent in any direction allowing for exact positioning of projection lens assembly 72 . For example, without limitation, the user may position projection lens assembly 72 to light a doorway or to slide between slats in window blinds so that circuit housing 70 is attached to the window and projection lens assembly 72 is visible in the room. Solar collection panels 71 charge power source 67 any time there is light. Once it becomes dark, photocell 75 activates LED light sources 62 and 63 to illuminate projection lens assembly 72 . In an alternate embodiment, the solar collection panels may be located on the front of the circuit housing so that the nightlight may be attached to a surface other than a window such as, but not limited to, a mirror, a wall, a piece of furniture, etc. and still collect light.
Having fully described at least one embodiment of the present invention, other equivalent or alternative methods of providing a solar nightlight according to the present invention will be apparent to those skilled in the art. The invention has been described above by way of illustration, and the specific embodiments disclosed are not intended to limit the invention to the particular forms disclosed. For example, the particular implementation of the light may vary depending upon the intended use. The embodiments described in the foregoing were directed to nightlight implementations; however, similar techniques are to implement embodiments of the present invention as different types of lights such as, but not limited to, reading lights, flashlights, accent lights, decorative lights, holiday lights, etc. Non-nightlight implementations of the present invention are contemplated as within the scope of the present invention. The invention is thus to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the following claims. | An apparatus for a solar window nightlight includes at least one battery contained within a circuit housing. Solar panels are disposed on an outside surface of the circuit housing for charging the battery. Control circuitry connects the battery, the solar panels and LED lights to control operations of the LED lights and charging of the at least one battery. A photocell is connected to the control circuitry where when ambient light falls below a predetermined level, the control circuitry activates the LED lights. Translucent lenses include a bore hole in a base for receiving one of the LED lights and reflective material on outside edges. Suction cups retain the apparatus on a window surface where, during day light hours, there is sufficient ambient light to charge the battery and, during night hours, the translucent lenses illuminate a desired area. | 5 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority from and is a continuation-in-part of U.S. Ser. No. 10/431,490 filed on May 6, 2003 entitled “Pet Food Treat and Method of Making Same”, the disclosure of which is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to the production of food products, and more particularly to pet food teats, and methods of making the food products by extrusion of suitable grain.
BACKGROUND OF THE INVENTION
[0003] Pet foods for dogs and cats are typically prepared as either canned or dry meal type rations. These rations are commonly formulated from a combination of proteinaceous and farinaceous materials. Farinaceous materials are derived from various cereal grains, and proteinaceous materials are derived from either vegetable protein sources or from meat and/or meat by-products. It is also well known to add various nutritional supplements to both meal and canned rations such as vitamins, minerals, etc.
[0004] Dry meal type rations typically have a cereal-like texture and a low moisture content around 10%. Dry rations can be produced to provide a completely balanced diet for an animal. Dry rations also have excellent storage characteristics, thus permitting use of relatively inexpensive packaging techniques.
[0005] Canned rations have a meat-like texture and a high moisture content. The elevated moisture content of such canned foods requires thermal processing in sealed containers to obtain a commercially sterile product, thereby adding considerably to product costs. Once a can is opened, it must be quickly consumed since the high moisture content is conducive to supporting microbial growth, and hence the product will deteriorate rapidly unless stored in refrigerated conditions.
[0006] A third type of animal food has become popular more recently which can be characterized as intermediate moisture products, typically having a moisture content in the range of about 15 to 30%. For these intermediate products, in order to prevent microbial decomposition, such products must be specially processed through pasteurization, or must be chemically treated with various preservatives, and/or must be packaged in sealed containers which are commercially sterilized. Another approach to preserving these intermediate moisture products is to disperse an aqueous phase of water-soluble solids throughout the product, the soluble solids being principally sugar at a level high enough to exert a bacteriostatic effect sufficient to stabilizing animal food. Like canned rations, these intermediate products are more expensive to produce because of the need to specially package or preserve the products.
[0007] Conventional methods for producing dry rations involve either extrusion or palletizing techniques wherein the dry rations are formed in a desired size and shape for a particular animal. The mixed farinaceous and/or proteinaceous sources of dry rations in extrusion are subjected to the action of the extruding machine which mixes the materials, and exposes them to heat and elevated pressures thereby converting the materials to a flowable semi-liquid substance. The temperature of the mixed materials passing through the extruder is typically above 212° F. The heated materials are expelled through die in the extruder device to atmospheric pressure, so that the heated moisture within the mixture flashes to steam causing the material to expand into a cellular mass. The cellular mass is then cut into pieces of a desired length, dried to a stable moisture content, and then treated with a flavored coating or with a chemical coating to preserve the product. The materials used to make most dry rations are also mixed prior to extrusion with various chemical preservatives to enhance the stability of the ration, and/or to assist in extrusion of the material. Although dry rations have a relatively long shelf life, depending upon the particular type of cereal grain or protein source used in the extrusion, there is still a need to preserve the ration with some type of chemical preservative.
[0008] It is well known to use various types of cereal grains in an extrusion process to produce feed having characteristics reflective of the particular type of cereal grain which is used. One reference which discloses a method of making a pet snack food, to include disclosure of various of types of cereal grains which may be used to make pet food an extrusion process is the U.S. Pat. No. 5,894,029.
[0009] Another reference disclosing animal feed which is produced through an extrusion process, and composed of proteinaceous and/or farinaceous material, is the U.S. Pat. No. 4,143,169.
[0010] Among the cereal grains used for making pet food or pet treats, corn and wheat are perhaps the most well known. Other types of grains may be added in smaller portions to the larger portions of wheat or corn in those dry food rations which are made by extrusion.
[0011] As pet food and pet food treats continue to develop in sophistication based upon a market which is increasingly conducive to sale of diversified pet products, new techniques for producing the pet foods also continue to develop. Despite pet food product diversification, basic food production still includes the need to provide healthy, inexpensive, and easily packaged food products.
[0012] Sorghum Vulgare is perhaps the oldest domesticated plant known to man. It has been hybridized since early Egyptian years and is very diversified in its hybrid state. Varieties commonly referred to as Milo have few if any uses other than for animal feed. Sorghum Vulgare is widely used in the United States as a less expensive feed grain in comparison to corn or wheat. Other parts of the world, particularly Africa and Asia, use Sorghum for flour and human food. In the United States, Milo as a particular group of hybrids, is a very different type of cereal grain as compared to Sorghum which is grown in other parts of the world. In the United States, a need was established early on for developing a feed grain that was resistant to various growing problems. These problems included drought, insect infestations, migrating birds, and high winds. As a result of these factors, Milo has evolved into special hybrids which are able to withstand the various growth problems. Accordingly, the type of Sorghum available particularly in the United States is a very successful grain, but is not well suited for any use other than standard feed grain.
SUMMARY OF THE INVENTION
[0013] One object of the present invention is to provide an animal food product which utilizes a grain which is inexpensive, easily extrudable, and has high nutrition value.
[0014] Another object of the present invention is to provide an animal food product which may readily accept a flavoring or additive in the extrusion process thereby eliminating the need for a separate processing step in incorporating the additive.
[0015] It is yet another object of the present invention to provide an animal food product which may be varied in its texture, weight, size and density based upon the moisture content of the materials which are extruded to make the food product.
[0016] It is yet another object of the present invention to provide an animal food product which has an extended shelf life, and does not require chemical preservatives or special packaging in order to maintain the extended shelf life.
[0017] It is yet another object of the present invention to provide a process for making an animal food product wherein the process may be easily adapted to produce animal food products of a desired size, density, weight, nutritional value and flavorings.
[0018] The products of the present invention comprise a matrix preferably manufactured from Milo seeds which at least have been decorticated resulting in berry and berry particulates which may then be exposed directly to extrusion. Additives may be added to the processed Milo prior to extrusion. The additives may be nutritional supplements and/or specific flavorings which enhance the nutritional value and palatability of the product.
[0019] In accordance with the method of the present invention, a desired stock of Milo grain is chosen, and the selected grain is cleaned and sized. In the cleaning operation, a destoning operation may be incorporated to remove any hard material of like size and shape, such as small stones or pebbles. The Milo grain is then decorticated in one of several known methods of grain decorticating. The decortication removes the husks or hulls of the Milo seeds. Optionally, the remaining berry and berry particulates are then passed through a scourer to remove the fatty endogerm portion of the berries. De-fatting of the berries can enhance the ability of the Milo grain to be extruded because fat can act as a lubricant in extrusion thereby degrading the ability of an extruder to produce a consistent food product. The next step in production of the food is an extrusion wherein a bake-type extruder is used under preferred heat and pressure ranges. The product produced in the extrusion process can be defined as a matrix of Milo which may carry an additive. One advantage of extrusion is that it also serves to kill bacteria and other microbes thereby helping to provide a product of increased shelf life.
[0020] After extrusion, the matrix may be considered in its final form, with the exception of curing which may be required. The extruded matrix may be light and puffy, or more dense having a crunchy, nugget type consistency, such as in pellet form. For the denser extruded matrix, it may directly cut into desired pellet sizes as the matrix exits the extruder die. The pellets then may be stored for further processing.
[0021] The matrix may be further processed to create a final product. One way in which the matrix may be further processed is to immediately transfer it into a mold cavity wherein the matrix or extrudate is molded into a desired shape. For example, a tube of a desired diameter can directly interconnect the matrix exiting the die of the extruder with a cavity of a mold whereby the matrix is injected into the mold cavity. Alternatively, the tube can be one which allows some expansion of the matrix as it leaves the die of the extruder, yet still maintaining the matrix under pressure so that it maintains a flowable state, thereby ensuring that the matrix can be injected into the mold cavity. Then, the matrix within the mold cavity would be allowed to “set” into the desired form, thereby creating a final product of a desired shape. The molds can be heated or cooled to achieve a product having desired hardness and texture.
[0022] Another option in further processing of the matrix or extrudate after extrusion would be to cure and dry the matrix, and then at some later time introduce the matrix into a mold thereby creating a final product of a desired shape. For this particular option, the matrix may have to be reworked prior to delivering the matrix to an injection molding machine. For example, the matrix could be crushed and/or sheared to place it in a powdered form, and a plasticizer, glycerin, or other ingredients could be added to place the matrix in a form that allows creation of a final product with a desired hardness or texture. Examples of plasticizers include gelatin, tapioca, gluten, starch, or carrageenan. If the matrix was already placed in pellet form as mentioned above, then rework may be unnecessary because the pelletized matrix could be directly added to an injection molding machine.
[0023] Yet another option in creating a final product from the matrix would be to rework the matrix to create a fine powder, thereby having a flour-type consistency. Water could be mixed with the fine powder to provide the matrix in a dough-like form. The dough-like matrix could be pushed or pressurized through a die and cut into desired shapes. The shaped matrix can then be baked or flashed to create a final product.
[0024] Placing the matrix in a pellitized form can occur through the extrusion wherein the matrix is relatively small and dense. As mentioned above, the size of the matrix which result from extrusion depends upon moisture content, heat, and pressure. Accordingly, a pellitized form of the matrix can be achieved without further rework. On the other hand, a pellitized form of the matrix can also be achieved by the subsequent rework process wherein the matrix is crushed or ground, and then the crushed/ground matrix is then introduced into a pellitizing machine. Of course, if it is known that the matrix needs to be in the pellitized form when the Milo grain is first processed, then it would be preferable to create the pellitized matrix directly from the extrusion.
[0025] If the matrix is to be further processed by a subsequent molding or baking process, it has been found that use of a denser matrix with a higher moisture content provides best results.
[0026] As mentioned above, one additional step that may be required in the process is to cure the product, preferably at a room temperature with a minimum of 60% air moisture content, until the product is stable. This curing step is affected by the type of additives which may be added to the matrix.
[0027] In accordance with another aspect of the present invention, other types of grains or even tubers may be used to produce a desired food product wherein the method of production requires an additional step of removing the starch from the grain/tuber. Other grains which may be selected include corn, wheat, rice, and others. The extracted starch is the portion of the grain/tuber which is used, and the remaining portions are discarded. Typically, for starch based products which are extruded, flavorings are not added until after the extrusion process thereby increasing the complexity and overall cost of producing the food product. With the use of other types of grains, this later flavor adding step can be eliminated by directly adding the flavorings prior to extrusion. For most other grain types, an additional processing step is required which is to remove the starch from the rest of the grain or tuber, the removed starch typically being in a powdered form. The starch may be removed in any well-known starch removal process to produce a basic starch powder.
[0028] Other features and advantages of the present invention will become apparent from a review of the following detailed description, taken in conjunction with the drawing, which illustrates the preferred embodiments of the method of the present invention.
BRIEF DESCRIPTION OF THE DRAWING
[0029] [0029]FIG. 1 is a flowchart showing the basic steps used in processing Milo grain to produce a food product according to the present invention.
DETAILED DESCRIPTION
[0030] Referring to FIG. 1, the basic steps in the methods of making the food product of the present invention are illustrated. In a first step at block 10 , a pure stock of grain Milo is selected. Although there is no specific hybrid of Milo which is required for the product and method of the present invention, it is desirable to choose a single pure stock grain because this pure stock grain is advantageous in creating repeatability of the extrusion process. Each hybrid of Milo may contain its own unique protein sequence. Even small differences in protein sequence may alter a particular extrusion. Therefore, by deliberately selecting grains with the same desired protein sequence, extrusion can be more reliably repeated.
[0031] The next step in the process shown at block 12 is to clean and size the Milo grain. Standard cleaning and sizing equipment may be used to process the grain at this step wherein air/water streams may be used to clean the grain, and the grain may be passed through various sieves to obtain the desired grain size. There is no required grain size for the present invention, and it has been found in testing that many different grain sizes can be used with good extrusion results.
[0032] Shown at block 14 is a next step in the process which is an optional destoning operation to remove stones or other similar sized objects which may still remain in the grain after cleaning and sizing. Although a destoning operation is shown as a separate optional step, destoning can be incorporated within a cleaning and sizing operation at step 12 . Therefore, it shall be understood that although destoning is shown separately in the flowchart, is not necessarily required to be a separate step in the method. Any well known destoning operation can be used.
[0033] The next step in the process is shown at block 16 which is the decortication of the Milo grain. Any one of several methods of usual grain decortication may be used to decorticate the Milo. For example, two references which disclose methods for decorticating Milo and which have been found to be particularly effective are the methods described in the U.S. Pat. Nos. 5,713,526 and 5,820,039. These two references are incorporated herein by reference for purposes of disclosing basic methods by which Milo grain may be decorticated. Another common method of decortication involves swirling the grain in a cyclone at a high rate of speed against a rasping surface. The grain contacts the rasping surface and breaks into pieces wherein the lighter, less dense hull is separated from the berry. Yet another common method is to expose the Milo grain to a stream of high-pressure water which separates the berry from the hull of the grain.
[0034] The next step in the method is shown at block 18 which is an optional step of scouring the grain to remove fatty oils or lipids. There are two distinct advantages for de-fatting the Milo grain at this stage. The first is enhancing the consistency and repeatability of the extrusion process because fats in the grain tend to act as a lubricant through the extrusion die, thereby degrading extruder operation. The second advantage is the production of a more nutritional pet food which has less fat content. Well-known grain scouring processes may be used to remove the fatty endogerm from the Milo grain. Although scouring is discussed as a step in the basic method, it shall be understood that scouring is not necessarily required as it may be desirable in some circumstances to have certain levels of fat within the food product. Additionally, scouring may be eliminated to simplify the overall food production process.
[0035] The next step in the method is shown at block 20 which involves introduction of a desired additive(s) to the processed Milo. The Milo and additive(s) may be referred to as a grain mix. For pet food, there are a number of additives which are contemplated within the present invention which may be advantageous for pet food or pet treats. Examples of these additives include, but are not limited to, additives in the form plant or animal protein sources. For example, one particularly advantageous additive is liver meal which is known to be preferred by almost all dogs. To create a pet treat incorporating liver meal having a light and puffy texture, the mixture ratio of the Milo to the liver meal would be from about 7:1 to about 12:1 by weight. Preferably, the ratio of the Milo to the liver meal is about 9:1 by weight. In order to provide an extrudable mixture, it is preferable to maintain the Milo at or around 16% moisture, and the liver meal at or around 20% moisture. Alternatively, to produce a pet treat which is not as puffy but rather is denser, smaller, and has more of a crunchy, nugget consistency, the ratio of Milo to liver meal would be from about 1:2 to about 5:2 by weight. Preferably, the ratio of Milo to liver meal would be about 3:2 by weight. For this denser product, the moisture content prior to extrusion is preferably about 18-22%. Other additives which may be used include vitamins, minerals or other nutritional supplements. These additives can be added at this step in prescribed amounts which do not pose a health risk to the animals even in the event that a particular animal would consume a large number of the treats at a single time. Yet additional types of additives which are also contemplated include medications, peanuts, fish meal, poultry meal, dried fruits or vegetables, flavored oils or other concentrated liquid flavorants, tubers, and even other types of grain such as wheat or bran. Milo is a grain which readily accepts a variety of additives, and there is little segregation or separation between the Milo grain and the additives in the extruded food product.
[0036] It may be desirable to mechanically mix the grain mix in a bin which will then meter the grain mix into the extrusion machine. Mechanical mixing helps to ensure uniform dispersion of the additive. It is also necessary to add water to the decorticated grain in order to create the grain mix with the necessary moisture content. It has been found in testing that Milo has approximately 10-12% moisture content prior to processing. In order to optimize extrusion, it has been found through testing that a moisture content of about 16% is preferable.
[0037] The next step in the method is illustrated at block 22 which involves extrusion of the Milo grain mix. Through testing, it has been found that extrusion can be achieved utilizing a bake-type extruder which exposes the grain mix to heat in the range of about 325° F. to about 400° F., and pressure in the range of about 1500 psi to about 2,000 psi. The particular shape of the die used in the extruding machine may be adapted to produce a food product of a desired shape. One example of a die could include the use of a die having a round shaped hole with a diameter of approximately 0.120 inch. The cutting mechanism used in the extruding machine can be adapted for cutting the extrudate to a length of about three-quarters inch. For a grain mix which is extruded having an overall moisture content of approximately 16%, the resulting extruded product has a light, puffy and cellular consistency at moisture contents between about 5-8%. As moisture content is increased in the grain mix, the resulting food product is smaller and denser as the product will experience less expansion during extrusion. For example, a food product having a more nugget-like consistency can be produced which is still crunchy, but does not have the puffy, cellular consistency. Temperature and pressure can also be adjusted within the extrusion process to produce a food product which is of a desired size, shape and density.
[0038] After extrusion, there are a number of options in providing a final product. If it is desired to simply sell the Milo matrix after extrusion, then one additional step shown at block 24 contemplates curing the food product to thereby stabilize the product prior to shipping. Depending upon the texture and consistency of the food product produced, i.e., one that is very puffed or more dense, a certain amount of curing may be required to allow the food product to reach equilibrium in terms of moisture content. Thus, the cured product could be light and puffy, or could be more dense such as in pellet form.
[0039] Another option after extrusion is to provide a molded product, shown at molding step 40 . A tubular member could directly interconnect the point at which the matrix exits the die of the extrusion device with a mold cavity. This intermediate tube could be sized to allow some or no expansion of the matrix as it exits the die of the extrusion device. In any event, the product must be maintained in somewhat of a flowable or molten state which allows the product to flow into the mold cavity. Once the product enters the mold, it is allowed to set and cool for a prescribed time, the molded product is then removed and is ready for shipping. The product may experience baking in the mold due to heat and pressure added during extrusion and heat added to the mold. Additionally, some curing may be required after the molding step 40 prior to shipping the molded product.
[0040] Yet another option in providing a final product would be to cure the extruded matrix at step 50 , and then sometime later, rework the cured matrix to provide either a molded product, a baked/flashed product, or a pellitized product. As shown in FIG. 1, the matrix would be reworked, as shown at block 52 . For example, the matrix could be crushed, sheared, pulverized, ground, milled, powdered, or combinations thereof. To produce a molded product as shown at step 54 , the matrix could be introduced into a hopper, the hopper then metering a desired amount of matrix into a crushing/shearing device, and the matrix then being forced into a mold under heat and pressure such as by a feed screw. As mentioned above, a plasticizer or other ingredients may be added to the matrix during rework. The reworked matrix in powdered form may also be baked or flashed to provide a final product as shown at step 56 . As necessary, the powdered matrix may receive additional liquid to increase the moisture content wherein a dough like consistency is achieved for baking or flashing. Baking or flushing can be achieved by use of a standard oven. Alternatively, the matrix may be reworked to place the matrix in a pellitized form, as shown at block 58 , assuming the matrix was not already pellitized in extrusion. Thus, the matrix as cured at step 50 could then be introduced to a pellitizing machine to produce pellets.
[0041] In accordance with another aspect of the present invention, other types of grains may be used to produce the food product. For example, corn, wheat and rice can also be used as the basic grains which make the matrix of the present invention. With these grains; however, an additional processing step is required to remove the starch from the remaining part of the grain. The removed starch is typically in powder form. In their natural state, these other grains are very difficult to extrude successfully, and therefore, the part of the grain to be extruded, the amylose starch, is separated from the whole grain prior to extrusion. Milo also contains starch, best characterized as an amylose-pectin starch. However, after decortication, Milo is readily extrudable without also having to first isolate the starch component of the grain.
[0042] In addition to grains in which starch has been removed for use in extrusion, it is also contemplated within the present invention to use the starch extracted from tubers, such as potatoes. As with the Milo grain, these extracted starches must also receive the required amount of water to raise the moisture content to a desired level corresponding to the texture and density of the final product.
[0043] Referring again to FIG. 1, the additional step of separating the starch is shown at block 30 in dotted lines. Additives are added to the starch in step 20 , and then the mixture is extruded at step 22 .
[0044] In accordance with another aspect of the invention, the grain mix can also be mixed with a gelatin prior to extrusion thereby increasing the hardness of the resulting extruded food product.
[0045] There are a number of advantages of utilizing a Milo matrix as a food product. First, there is the relatively low cost of producing such a food product as the processing steps for creating the Milo matrix can be achieved within a relatively simple grain processing method. Milo grain is a relatively high protein, low fat grain which is both palatable and easily digestible by both humans and animals. Processed Milo is generally hydrophobic, therefore very stable in all climates and storing conditions. Accordingly, the food product produced may be packaged and sold within packaging which does not have to be sealed or otherwise specially treated. For example, large bins of the Milo food product can be directly incorporated within retail locations where a consumer measures a desired amount of the food product to be purchased and then places the product into a plastic or paper bag. A Milo food product made by the above-described methods requires no chemical additives to preserve the product for extended shelf life. Another advantage as mentioned above is the ability to produce food products which have a variety of densities. Lighter, puffier products as well as denser, crunchier products may be easily produced. By varying the temperature and pressure of the extrusion, or adjusting the moisture content, the particular size and density of the product can be chosen. For example, extruding the Milo grain mix through a die having a round opening of about 0.120 of an inch in diameter and at about 16% moisture content, can produce a product having a width/diameter of approximately three-quarters inch, which then can also be cut to a desired length. Increasing the moisture to about 18% has been shown to produce a product having a width/diameter of approximately one-half inch. During the extrusion process, the heat and pressure advantageously kill bacteria and other undesirable microorganisms thereby increasing the shelf life of the product. Also during extrusion, the additives become evenly mixed within the decorticated grain thereby producing an evenly dispersed mixture. Accordingly, the additive is evenly distributed throughout each batch of the extruded pet food product in contrast to many other types of pet treats, into which flavorings or additives are incorporated by electrostatic processes which simply coat the exterior surfaces of the product. These electrostatic processes are less desirable because the flavoring/additive is more easily separated from the product. By creating a well dispersed mixture through the extrusion process of the present invention, the desired additive is better delivered to the consuming animal. The Milo matrix may also be reworked after extrusion by directly molding the extrudate, or by allowing the extrudate to cure, and then rework the matrix in a subsequent molding or baking/flashing process. Thus, large quantities of the matrix can be stored during an intermediate period, and then as required, final products may be made from the matrix at a later time. Because of the increased shelf life of the Milo matrix, temporarily storing the matrix after extrusion provides yet another option and ultimately providing a product based upon market demands, which can be seasonal thereby providing a food producer great flexibility as to when final product should be packaged and shipped.
[0046] The above invention has been described with respect to preferred embodiments; however, other changes and modifications may be made within the spirit and scope of the invention. | A food product and method of making the same are disclosed. The food product is preferably made of a processed Sorghum grain, and preferably from hybrids of Milo. The grain is subjected to decortication and extrusion. Additives may be provided to flavor or otherwise nutritionally enhance the processed Milo. The additives are added prior to extrusion. The food product may be made from other grains or tubers by removing the starch and then using the starch to extrude the food product. A final food product may be achieved by further processing of the extruded grain. Further processing may include molding, baking, or pelletizing. | 0 |
RELATED APPLICATIONS
[0001] This application is a continuation-in-part of U.S. patent application Ser. No. 11/581,629 filed Oct. 16, 2006 and U.S. patent application Ser. No. 11/435,906 filed May 17, 2006.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to a single-use medical device and more particularly to an ophthalmic drug delivery device with a mechanical linkage mechanism.
[0003] Several diseases and conditions of the posterior segment of the eye threaten vision. Age related macular degeneration (ARMD), choroidal neovascularization (CNV), retinopathies (e.g., diabetic retinopathy, vitreoretinopathy), retinitis (e.g., cytomegalovirus (CMV) retinitis), uveitis, macular edema, glaucoma, and neuropathies are several examples.
[0004] These, and other diseases, can be treated by injecting a drug into the eye. Such injections are typically manually made using a conventional syringe and needle. FIG. 1 is a perspective view of a prior art syringe used to inject drugs into the eye. In FIG. 1 , the syringe includes a needle 105 , a luer hub 110 , a chamber 115 , a plunger 120 , a plunger shaft 125 , and a thumb rest 130 . As is commonly known, the drug to be injected is located in chamber 115 . Pushing on the thumb rest 130 causes the plunger 120 to expel the drug through needle 105 .
[0005] In using such a syringe, the surgeon is required to puncture the eye tissue with the needle, hold the syringe steady, and actuate the syringe plunger (with or without the help of a nurse) to inject the fluid into the eye. The volume injected is typically not controlled in an accurate manner because the vernier on the syringe is not precise relative to the small injection volume. Fluid flow rates are uncontrolled. Reading the vernier is also subject to parallax error. Tissue damage may occur due to an “unsteady” injection. Reflux of the drug may also occur when the needle is removed from the eye.
[0006] An effort has been made to control the delivery of small amounts of liquids. A commercially available fluid dispenser is the ULTRA™ positive displacement dispenser available from EFD Inc. of Providence, R.I. The ULTRA dispenser is typically used in the dispensing of small volumes of industrial adhesives. It utilizes a conventional syringe and a custom dispensing tip. The syringe plunger is actuated using an electrical stepper motor and an actuating fluid. Parker Hannifin Corporation of Cleveland, Ohio distributes a small volume liquid dispenser for drug discovery applications made by Aurora Instruments LLC of San Diego, Calif. The Parker/Aurora dispenser utilizes a piezo-electric dispensing mechanism. Ypsomed, Inc. of Switzerland produces a line of injection pens and automated injectors primarily for the self-injection of insulin or hormones by a patient. This product line includes simple disposable pens and electronically-controlled motorized injectors.
[0007] U.S. Pat. No. 6,290,690 discloses an ophthalmic system for injecting a viscous fluid (e.g. silicone oil) into the eye while simultaneously aspirating a second viscous fluid (e.g. perflourocarbon liquid) from the eye in a fluid/fluid exchange during surgery to repair a retinal detachment or tear. The system includes a conventional syringe with a plunger. One end of the syringe is fluidly coupled to a source of pneumatic pressure that provides a constant pneumatic pressure to actuate the plunger. The other end of the syringe is fluidly coupled to an infusion cannula via tubing to deliver the viscous fluid to be injected.
[0008] It would be desirable to have a portable hand piece for injecting a drug into the eye that includes reliable technology. A mechanical lever can be utilized to provide accurate translation of a plunger to deliver a substance. The lever configuration can be such that it is activated by a finger or thumb to deliver a precise dosage. The hand piece may be a single piece unit or a two-piece device. Placing the more expensive components, including electronics and a battery, in a reusable assembly, while keeping the sterile components in a disposable assembly, improves the efficiency and cost-effectiveness of a drug delivery system. However, a single piece device with a relatively simple structure is also feasible. Such a system provides numerous benefits over prior art injectors.
SUMMARY OF THE INVENTION
[0009] In one embodiment consistent with the principles of the present invention, the present invention is an ophthalmic injection device having a dispensing chamber housing, a plunger, a needle, a temperature control device, a power source for providing power to the temperature control device, a controller for controlling the temperature control device, and a mechanical linkage mechanism. The dispensing chamber housing has an inner surface and an outer surface. The inner surface partially defines a dispensing chamber for holding a quantity of a substance. The plunger is engaged with the inner surface of the dispensing chamber housing, is capable of sliding in the dispensing chamber housing, and is fluidly sealed to the inner surface of the dispensing chamber housing. A plunger shaft is coupled to the plunger. The needle is fluidly coupled to the dispensing chamber. The temperature control device at least partially surrounds the dispensing chamber housing and is capable of altering the temperature of the substance in the dispensing chamber. The mechanical linkage mechanism has at least two pivots and at least two shafts and transfers force from a lever to the plunger.
[0010] In another embodiment consistent with the principles of the present invention, the present invention is an ophthalmic injection device having a tip segment attachable to and removable from a limited reuse assembly. The tip segment has a dispensing chamber housing, a plunger, a needle, and a temperature control device. The limited reuse assembly has a power source for providing power to the temperature control device, a controller for controlling the temperature control device, and a mechanical linkage mechanism. The dispensing chamber housing has an inner surface and an outer surface. The inner surface partially defines a dispensing chamber for holding a quantity of a substance. The plunger is engaged with the inner surface of the dispensing chamber housing, is capable of sliding in the dispensing chamber housing, and is fluidly sealed to the inner surface of the dispensing chamber housing. The plunger has a plunger interface for coupling with a plunger shaft. The needle is fluidly coupled to the dispensing chamber. The temperature control device at least partially surrounds the dispensing chamber housing and is capable of altering the temperature of the substance in the dispensing chamber. The mechanical linkage mechanism has at least two pivots and at least two shafts and transfers force from a lever to the plunger.
[0011] In another embodiment consistent with the principles of the present invention, the present invention is an ophthalmic injection device having a tip segment attachable to and removable from a limited reuse assembly. The tip segment has a dispensing chamber housing, a plunger, a needle, a temperature control device, and a mechanical linkage mechanism. The dispensing chamber housing has an inner surface and an outer surface. The inner surface partially defines a dispensing chamber for holding a quantity of a substance. The plunger is engaged with the inner surface of the dispensing chamber housing, is capable of sliding in the dispensing chamber housing, and is fluidly sealed to the inner surface of the dispensing chamber housing. The plunger has a plunger interface for coupling with a plunger shaft. The needle is fluidly coupled to the dispensing chamber. The temperature control device at least partially surrounds the dispensing chamber housing and is capable of altering the temperature of the substance in the dispensing chamber. The mechanical linkage mechanism has at least two pivots and at least two shafts and transfers force from a lever to the plunger. The limited reuse assembly has a power source for providing power to the temperature control device and a controller for controlling the temperature control device.
[0012] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are intended to provide further explanation of the invention as claimed. The following description, as well as the practice of the invention, set forth and suggest additional advantages and purposes of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate several embodiments of the invention and together with the description, serve to explain the principles of the invention.
[0014] FIG. 1 is a perspective view of a prior art syringe.
[0015] FIG. 2 is one view of an ophthalmic medical device including a disposable tip segment and a limited reuse assembly according to an embodiment of the present invention.
[0016] FIG. 3 is a cross section view of a disposable tip segment and a limited reuse assembly according to an embodiment of the present invention.
[0017] FIG. 4 is an exploded cross section view of a tip segment for an ophthalmic medical device according to an embodiment of the present invention.
[0018] FIG. 5 is a cross section view of an ophthalmic injection device according to the principles of the present invention.
[0019] FIG. 6 is a cross section view of a disposable tip segment and a limited reuse assembly according to an embodiment of the present invention.
[0020] FIGS. 7A and 7B are cross section views of a mechanical linkage mechanism according to the principles of the present invention.
[0021] FIGS. 8A-8C are diagrams showing the trigonometric relationship of a mechanical linkage mechanism according to the principles of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0022] Reference is now made in detail to the exemplary embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used throughout the drawings to refer to the same or like parts.
[0023] FIG. 2 is one view of an ophthalmic medical device including a disposable tip segment and a limited reuse assembly according to an embodiment of the present invention. In FIG. 2 , the medical device includes a tip segment 205 and a limited reuse assembly 250 . The tip segment 205 includes a needle 210 , a housing 215 , and an optional light 275 . The limited reuse assembly 250 includes a housing 255 , a switch 270 , a lock mechanism 265 , a lever 350 , and a threaded portion 260 .
[0024] Tip segment 205 is capable of being connected to and removed from limited reuse assembly 250 . In this embodiment, tip segment 205 has a threaded portion on an interior surface of housing 215 that screws onto the threaded portion 260 of limited reuse assembly 250 . In addition, lock mechanism 265 secures tip segment 215 to limited reuse assembly 250 . Lock mechanism 265 may be in the form of a button, a sliding switch, or a cantilevered mechanism. Other mechanisms for connecting tip segment 205 to limited reuse assembly 250 , such as those involving structural features that mate with each other, are commonly known in the art and are within the scope of the present invention.
[0025] Needle 210 is adapted to deliver a substance, such as a drug, into an eye. Needle 210 may be of any commonly known configuration. Preferably, needle 210 is designed such that its thermal characteristics are conducive to the particular drug delivery application. For example, when a heated drug is to be delivered, needle 210 may be relatively short (several millimeters) in length to facilitate proper delivery of the drug.
[0026] Switch 270 is adapted to provide an input to the system. For example, switch 270 may be used to activate the system or to turn on a heater. Other switches, buttons, or user-directed control inputs are commonly known and may be employed with limited reuse assembly 250 and/or tip segment 205 .
[0027] Optional light 275 is illuminated when tip segment 205 is ready to be used. Optional light 275 may protrude from housing 215 , or it may be contained within housing 215 , in which case, optional light 275 may be seen through a clear portion of housing 215 . In other embodiments, optional light 275 may be replaced by an indicator, such as a liquid crystal display, segmented display, or other device that indicates a status or condition of disposable tip segment 205 . For example, optional light 275 may also pulse on and off to indicate other states, such as, but not limited to a system error, fully charged battery, insufficiently charged battery or faulty connection between the tip segment 205 and limited use assembly 250 . While shown on tip segment 205 , optional light 275 or other indicator may be located on limited reuse assembly 250 .
[0028] FIG. 3 is cross section view of a disposable tip segment and a limited reuse assembly according to an embodiment of the present invention. FIG. 3 shows how tip segment 205 interfaces with limited reuse assembly 250 . In the embodiment of FIG. 3 , tip segment 205 includes dispensing chamber housing 425 , tip segment housing 215 , thermal sensor 460 , needle 210 , dispensing chamber 405 , plunger 415 , plunger shaft 380 , temperature control device 450 , interface 530 , tip interface connector 453 , and a mechanical linkage mechanism comprising lever 350 , pivot 365 , shaft 355 , coupling 370 , shaft 360 , and pivot 375 . Limited reuse assembly 250 includes power source 505 , controller 305 , limited reuse assembly housing 255 , interface 535 , and limited reuse assembly interface connector 553 .
[0029] In tip segment 205 , plunger 415 is adapted to slide within dispensing chamber 405 . The outer surface of plunger 415 is fluidly sealed to the inner surface of dispensing chamber housing 425 . Dispensing chamber housing 425 surrounds the dispensing chamber 405 . Typically, dispensing chamber housing 425 has a cylindrical shape. As such, dispensing chamber 405 also has a cylindrical shape.
[0030] Needle 210 is fluidly coupled to dispensing chamber 405 . In such a case, a substance contained in dispensing chamber 405 can pass through needle 210 and into an eye. Temperature control device 450 at least partially surrounds dispensing chamber housing 425 . In this case, temperature control device 450 is adapted to heat and/or cool dispensing chamber housing 425 and any substance contained in dispensing chamber 405 . Interface 530 connects temperature control device 450 with tip interface connector 453 .
[0031] Optional thermal sensor 460 provides temperature information to assist in controlling the operation of temperature control device 450 . Thermal sensor 460 may be located near dispensing chamber housing 425 and measure a temperature near dispensing chamber housing 425 or may be located in thermal contact with dispensing chamber housing 425 , in which case it measures a temperature of dispensing chamber housing 425 . Thermal sensor 460 may be any of a number of different devices that can provide temperature information. For example, thermal sensor 460 may be a thermocouple or a resistive device whose resistance varies with temperature. Thermal sensor is also electrically coupled to interface 530 or other similar interface.
[0032] The components of tip segment 205 , including dispensing chamber housing 425 , temperature control device 450 , and plunger 415 are at least partially enclosed by tip segment housing 215 . In one embodiment consistent with the principles of the present invention, plunger 415 is sealed to the interior surface of dispensing chamber housing 425 . This seal prevents contamination of any substance contained in dispensing chamber 405 . For medical purposes, such a seal is desirable. This seal can be located at any point on plunger 415 or dispensing chamber housing 425 .
[0033] In limited reuse assembly 250 , power source 505 is typically a rechargeable battery, such as a lithium ion battery, although other types of batteries may be employed. In addition, any other type of power cell is appropriate for power source 505 . Power source 505 provides current to dispensing chamber housing 425 to heat it and change its shape. Optionally, power source 505 can be removed from housing 255 through a door or other similar feature (not shown).
[0034] Controller 305 is typically an integrated circuit with power, input, and output pins capable of performing logic functions. In various embodiments, controller 305 is a targeted device controller. In such a case, controller 305 performs specific control functions targeted to a specific device or component, such as a temperature control device or a power supply. For example, a temperature control device controller has the basic functionality to control current delivered to dispensing chamber housing 425 . In other embodiments, controller 305 is a microprocessor. In such a case, controller 305 is programmable so that it can function to control more than one component of the device. In other cases, controller 305 is not a programmable microprocessor, but instead is a special purpose controller configured to control different components that perform different functions. While depicted as one component in FIG. 4 , controller 305 may be made of many different components or integrated circuits.
[0035] Controller 305 is connected via interface 535 to limited reuse assembly interface connecter 553 . Limited reuse assembly interface connecter 553 is located on a top surface of limited reuse assembly housing 255 . In this manner, limited reuse assembly interface connector 553 is adapted to be connected with tip interface connector 453 to provide an electrical connection between tip segment 205 and limited reuse assembly 250 .
[0036] An interface between power source 505 and controller 305 allows controller 305 to control operation of power source 505 . In such a case, controller 305 may control the charging and the discharging of power source 505 when power source 505 is a rechargeable battery.
[0037] In operation, when tip segment 205 is connected to limited reuse assembly 250 , the device is ready to be used for an injection. When lever 350 is actuated, coupling 370 moves towards tip segment housing 215 . Shaft 360 is rotated moving pivot 375 and plunger 415 upward toward needle 210 . A substance located in dispensing chamber 405 is then expelled through needle 210 .
[0038] Controller 305 controls the operation of temperature control device 450 . Temperature control device 450 is adapted to heat and/or cool dispensing chamber housing 425 and its contents. Since dispensing chamber housing 425 is at least partially thermally conductive, heating or cooling dispensing chamber housing 425 heats or cools a substance located in dispensing chamber 405 . Temperature information can be transferred from thermal sensor 460 through interface 530 , tip interface connector 453 , limited reuse assembly interface connector 553 , and interface 535 back to controller 305 . This temperature information can be used to control the operation of temperature control device 450 . When temperature control device 450 is a heater, controller 305 controls the amount of current that is sent to temperature control device 450 . The more current sent to temperature control device 450 , the hotter it gets. In such a manner, controller 305 can use a feed back loop utilizing information from thermal sensor 460 to control the operation of temperature control device 450 . Any suitable type of control algorithm, such as a proportional integral derivative (PID) algorithm, can be used to control the operation of temperature control device 450 .
[0039] A substance to be delivered into an eye, typically a drug suspended in a phase transition compound, is located in dispensing chamber 405 . In this manner, the drug and phase transition compound are contacted by the inner surface of dispensing chamber housing 425 . The phase transition compound is in a solid or semi-solid state at lower temperatures and in a more liquid state at higher temperatures. Such a compound can be heated by the application of current to temperature control device 450 to a more liquid state and injected into the eye where it forms a bolus that erodes over time.
[0040] In one embodiment of the present invention, the substance located in dispensing chamber 405 is a drug that is preloaded into the dispensing chamber. In such a case, tip segment 205 is appropriate as a single use consumable product. Such a disposable product can be assembled at a factory with a dosage of a drug installed.
[0041] FIG. 4 is an exploded cross section view of a tip segment for an ophthalmic medical device according to an embodiment of the present invention. In FIG. 4 , tip segment 205 includes dispensing chamber housing 425 , tip segment housing 215 , thermal sensor 460 , needle 210 , dispensing chamber 405 , plunger 415 , plunger shaft 380 , temperature control device 450 , interface 530 , tip interface connector 453 , an optional luer 430 , and a mechanical linkage mechanism comprising lever 350 , pivot 365 , shaft 355 , coupling 370 , shaft 360 , and pivot 375 . Optional luer secures needle 210 to dispensing chamber housing 425 .
[0042] In the embodiment of FIG. 4 , temperature control device 450 is activated to bring a substance in dispensing chamber 405 to the proper temperature. Thermal sensor 460 provides temperature information to controller 305 (not shown) to control temperature control device 450 . After the substance has reached the proper temperature, lever 350 is actuated to drive plunger toward needle 210 to dispense a substance contained in dispensing chamber 405 .
[0043] The mechanical linkage mechanism that includes lever 350 is designed to use a force applied to lever 350 to translate plunger 415 within dispensing chamber housing 425 . Lever 350 is hand actuated with a finger or thumb. In one embodiment, a thumb is used to rotate lever 350 about pivot 365 . Since lever 350 is rigidly connected to shaft 355 , when lever 350 is rotated upward about pivot 365 , shaft 355 rotates downward about pivot 365 . This in turn causes coupling 370 to rotate downward about pivot 365 . Shaft 360 rotates downward about pivot 375 moving plunger shaft 380 (and plunger 415 to which plunger shaft 380 is rigidly connected) toward needle 210 . The movement of plunger 415 dispenses the substance contained in dispensing chamber 405 .
[0044] FIG. 5 is a cross section view of an ophthalmic injection device according to the principles of the present invention. In FIG. 5 , the injection device is integrated into a single unit. The single piece device of FIG. 6 operates in the same manner as the two piece device previously described. In FIG. 6 , the device includes dispensing chamber housing 425 , dispensing chamber 405 , needle 210 , thermal sensor 460 , interface 536 , controller 305 , power source 505 , and housing 216 . In FIG. 6 , a single interface 536 is used instead of two separate interfaces ( 530 and 535 ) and two separate connectors ( 453 and 553 ). Housing 216 encloses the components pictured.
[0045] FIG. 6 is cross section view of a disposable tip segment and a limited reuse assembly according to an embodiment of the present invention. In FIG. 6 , the mechanical linkage mechanism is in limited reuse assembly 250 and not in tip segment 205 as depicted in FIG. 3 . In FIG. 6 , plunger shaft 380 interfaces with plunger 415 at plunger interface 420 . Any number of different interfaces can be used including interfaces that are rigidly connected when engaged or those in which force is only transferred in a single direction (as shown in FIG. 6 ). The embodiment of FIG. 6 has the characteristics and operates in the same manner as the embodiment of FIG. 3 .
[0046] FIGS. 7A and B are cross section views of a mechanical linkage mechanism according to the principles of the present invention. In FIG. 7A , lever 350 has not been actuated. In FIG. 7B , lever 350 has been actuated and a substance 650 has been dispensed from dispensing chamber 405 .
[0047] In FIGS. 7A and 7B , lever 350 is rigidly connected to shaft 355 . Pivot 365 is disposed between lever 350 and shaft 355 so as to provide a first rotation point. Pivot 365 is stationary. A rotatable coupling 370 joins shaft 355 to shaft 360 . In this manner, shaft 355 can rotate with respect to shaft 360 . Pivot 375 connects shaft 360 to plunger shaft 380 . In this manner, shaft 360 rotates about pivot 375 . Pivot 375 moves in a direction along plunger shaft 380 . Since plunger shaft 380 is constrained to move only in a direction along dispensing chamber housing 425 , plunger shaft 380 does not rotate. Instead, when shaft 360 rotates about pivot 375 , plunger shaft 380 moves in dispensing chamber housing 425 .
[0048] When a force is applied to lever 350 , lever 350 and shaft 355 rotate about pivot 365 . When the force rotates lever 350 upward, shaft 355 is rotated downward. Coupling 370 is moved downward along the arc of a circle with a radius equal to the length of shaft 355 and with its center at pivot 365 . As coupling 370 moves, shaft 360 also moves. In this case, shaft 360 moves generally downward and rotates about pivot 375 . Pivot 375 moves along an axis defined by plunger shaft 380 . As shaft 360 moves downward, pivot 375 moves toward needle 210 . Plunger 415 moves in dispensing chamber housing 425 to expel substance 460 as shown in FIG. 6B .
[0049] FIGS. 8A-8C are diagrams showing the trigonometric relationship of a mechanical linkage mechanism according to the principles of the present invention. In FIGS. 8A-8C , Φ measures the angle of the arc through which coupling 370 travels. This is also the angle through which lever 350 and shaft 355 rotates. The point (X 370 , Y 370 ) is the position of coupling 370 . The angle α is the complement of the angle through which shaft 360 travels. In other words, α measures the angle from an axis defined by plunger shaft 380 to shaft 360 . L 1 is the length of shaft 360 , L 2 is the length of plunger shaft 380 , and L 3 is the length of shaft 355 . Pivot 365 is stationary and pivot 375 moves only in a direction along the dashed straight arrow. The point (X 375 , Y 375 ) is the position of coupling 375 . The distance D Y is the distance between pivot 365 and the dashed line along which plunger shaft 380 travels. Given these parameters, a simple trigonometric relationship among the various components is shown.
[0050] From the above, it may be appreciated that the present invention provides an improved system for delivering precise volumes of a substance into an eye. The present invention provides a mechanical linkage mechanism that can be easily actuated by the hand to deliver a substance into an eye. In one embodiment, a disposable tip segment that interfaces with a limited reuse assembly is employed. In another embodiment, a single unit is employed. The present invention is illustrated herein by example, and various modifications may be made by a person of ordinary skill in the art.
[0051] Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims. | An ophthalmic injection device has a dispensing chamber housing, a plunger, a needle fluidly coupled to a dispensing chamber, a temperature control device, a power source for providing power to the temperature control device, a controller for controlling the temperature control device, and a mechanical linkage mechanism. The interior surface of the dispensing chamber housing partially defines a dispensing chamber for holding a quantity of a substance. The plunger is engaged with the inner surface of the dispensing chamber housing, is capable of sliding in the dispensing chamber housing, and is fluidly sealed to the inner surface of the dispensing chamber housing. A plunger shaft is coupled to the plunger. The temperature control device can alter the temperature of the substance contained therein. The mechanical linkage mechanism has at least two pivots and at least two shafts and transfers force from a lever to the plunger. | 0 |
BACKGROUND
[0001] Electric power demand varies greatly during the day. The consumption that generates the demand is at the highest in the day time when industrial activities are also at the highest level. The demand is reduced to its minimum during the night time when less power is needed for lighting and when other industrial activities are also at the lowest level. The wide variations of daily power demand is also influenced by low consumption during weekends when less power is needed due to reduced industrial or business activities. Seasonal effects such as high load for air conditioning during the hot summer seasons or high heating loads in cold winter months also have additional impacts on the levels of power peaks or power off-peaks. This wide fluctuation is well known and utility companies must cope with it by providing spare capacity on the power grid to accommodate higher demand periods, and by having equipment configuration such that power blocks or generating units are capable of being taken off line when demand drops.
[0002] Coal power plants and nuclear power plants, typically low cost fuel power plants, are relatively slow in capacity adjustment and load adaptation due to heavy equipment's inertia or safety constraints. For this reason, they are usually operated as base load plants to satisfy the core of the requirement.
[0003] When power demand increases, backup peak shaving gas turbines, operated on relatively costly natural gas, can be started to keep up with the demand. It is obvious that the backup equipment must be able to get on stream very quickly because the demand peaks can occur quite rapidly and usually, instantaneously. It is also clear that, mainly because of economic reasons, the backup equipment cost must be minimized since they are only needed for short durations and not permanently. Gas turbines for base load plants are usually equipped with combined cycle to maximize the overall cycle efficiency. Steam boiler and condensing steam turbines of the combined cycle are high cost items and require relatively long time, in a matter of several hours, to be fully on stream. Because of those shortcomings, peak shaving gas turbines are simple cycle, not equipped with combined cycle, to yield the lowest investment cost per kW installed. Therefore the efficiency of the peak shaving gas turbine must be compromised.
[0004] The fluctuations of the power demand can be smoothed out by providing an energy storage system: power is stored during the low demand periods and disbursed back to the grid during the high demand periods. A typical example of this setup is a hydraulic water pumping system: the surplus of power during the off-peak periods can be used to drive water pumps to send water from a low basin reservoir to a reservoir located at a higher elevation. When power demand increases, this water is returned to the low elevation reservoir by sending it to hydraulic turbines to generate supplemental electric power. The ramp-up is quite fast for this system. However, this setup is of course not applicable to most power plants since it requires an expensive infrastructure using high and low elevation reservoirs along with multiple large hydraulic turbines. In addition to the high global investment cost, the recovery, defined as the ratio of electricity output over the electricity input, is only in the range of about 60% due to the fact that the reservoirs are likely to be at remote locations such that transmission line losses can be quite high and the efficiencies of the pumps and hydraulic turbines are in the range of only about 70%. Therefore an efficient and economical process of storing energy is desirable to address the issue of power demand fluctuations.
[0005] More and more power generation plants are being built with combustion gas turbine technology. Because of environmental issues, coal based power plants with gasification technology (IGCC Integrated Gasification Combined Cycle) are being built or selected for several projects. In the regions of the world where natural gas is available at relatively low cost, combined cycle natural gas power plant for base load operation is the technology of choice. Gas turbine concept by itself is not very efficient since about 50% of the turbine's power is wasted to compress the air for the combustion and expansion. However, the gas turbine cycle efficiency is improved significantly by adding a steam combined cycle on the turbine's exhaust gas: the waste heat of the exhaust gas is used to heat and vaporized water to form high pressure steam which is then expanded in steam turbines to generate additional power. The combined cycle concept is widely used today in the power generation industry. However, because of the complexity and the high cost of the multiple pressure heat recovery steam generation system (HRSG) and the steam turbines, and the heavy infrastructure of the very large cooling tower for the steam condensing circuit, the steam combined cycle can only be justified economically for plants larger than about 50 MW or even 100 MW. Plant size can be smaller in case of cogeneration when clients are available to purchase steam produced by the facility and to partially pay for the cost of the steam system. Because of this economic constraint, many small plants are operated based on a simple cycle concept, i.e. no combined cycle, with significant penalty on the cycle efficiency. Gas turbine vendors are implementing several improvements to the gas turbine technology in order to reduce the impact of poor efficiency such as increasing pressure ratio thus reducing exhaust temperature, or improving turbine's blade heat resistance to accommodate higher inlet temperature or using recuperated gas turbine approach. However those changes only result in smaller incremental improvement to the process efficiency. Therefore another approach less costly than the steam combined cycle capable of improving the efficiency of the gas turbine power generation system is highly desirable especially for the small and medium size plant application.
[0006] When power demand increases, backup peak shaving gas turbines, operated on relatively costly natural gas, can be started to keep up with the demand. It is obvious that the backup equipment must be able to get on stream very quickly because the demand peaks can occur quite rapidly and usually, instantaneously. It is also clear that, mainly because of economic reasons, the backup equipment cost must be minimized since they are only needed for short durations and not permanently. Gas turbines for base load plants are usually equipped with combined cycle to maximize the overall cycle efficiency. Steam boiler and condensing steam turbines of the combined cycle are high cost items and require relatively long time, in a matter of several hours, to be fully on stream. Because of those shortcomings, peak shaving gas turbines are simple cycle, not equipped with combined cycle, to yield the lowest investment cost per kW installed. Therefore the efficiency of the peak shaving gas turbine must be compromised.
[0007] Atmospheric air is a potential candidate for the medium used for energy storage. For example, air can be compressed during off-peak periods to higher pressure and stored in large underground cavern created by solution mining. During peak load periods, pressurized air of the storage can be heated by combusting natural gas to high temperature then expanded in gas turbine for power recovery. The efficiency of the power recovery depends upon the type of compression used to compress the air: adiabatic, diabatic or isothermal. This concept is simple but, similar to the water pumping scheme, requires important capital expenditure for the infrastructure. Site locations in case of mining solution are usually very remote.
[0008] To minimize the storage size and the associated cost of compressed air system, air can be liquefied by cryogenic technique and stored economically in large quantity in conventional storage tank. This air, in liquid form, can be vaporized and transformed into gaseous form to restore the compressed air needed for power generation. This technique is promising because it facilitates the compress air energy storage approach without the high cost associated with the underground cavern at remote locations. A facility for air liquefaction can be easily deployed near the main users like large cities. The technology of air liquefier and cryogenic storage are very well known and can be implemented quickly and reliably. However, several technical issues must be resolved before this approach can be used economically.
[0009] An object of this invention is to provide a technique of using liquid air to store energy. Liquefaction of air requires energy input, the specific power required to liquefy the air is about 0.5 kWh/Nm3. The liquefaction power can be improved slightly at the expense of higher investment cost for the equipment. This energy input must be recovered efficiently in the vaporization step otherwise the overall process efficiency will suffer. Therefore it is desirable to provide an efficient process for liquid air vaporization.
[0010] Considering that the liquefaction is an energy intensive process, it is advantageous to avoid this liquefaction during the peak load periods where power cost is at the premium. Therefore liquefaction during off-peak periods, for example at night time, will maximize the cost effectiveness of the concept. Power consumption for equipment such as compressors in the vaporization step must be kept at a minimum.
[0011] One potential technique of reducing power consumption of equipment is to utilize the cold or refrigeration supplied by cryogenic liquid of the cold compression process. Cold compression reduces the power consumption of the compressor significantly because the inlet temperature of the compressor is at very low level, usually in the range of −180° C. to −60° C. However, the main penalty of the cold compression is that the heat generated by the compression, even quite low at cryogenic level, must be evacuated at that cryogenic temperature level such that the required refrigeration will adversely effect the overall power consumption. In case the source of refrigeration available for the heat removal is a low cost cryogenic liquid produced inexpensively during off-peaks then cold compression becomes quite attractive.
[0012] This invention relates to an improved technique of using liquid air as the energy storage medium. Liquid air produced and stored in off-peak periods can be restored to compressed air under high pressure by an efficient vaporization process assisted with cold compression technology. The compressed air is then heated and expanded in a compressed air combined cycle to generate additional power in peak periods and to improve the efficiency of the gas turbine without a costly steam combined cycle.
[0013] The use of this invention can extend the concept of combined cycle to medium and small power gas turbine power generating units without the high cost and slow response of the traditional steam turbine combined cycle.
SUMMARY
[0014] A method of liquid air energy storage is described. This method includes liquefying and storing air to form a stored liquid air during a first period of time. The method also includes during a second period of time, introducing a compressed air stream ( 108 ) into a cryogenic system, wherein the cryogenic system comprises at least one cold compressor, and at least one heat exchanger. The method includes cooling the compressed air stream ( 108 ) within the heat exchanger producing a first cooled compressed air stream and a second cooled compressed air stream. The method includes further cooling at least a portion of the first cooled compressed air stream, thereby producing a further cooled compressed air ( 115 ).
[0015] In various combinations, the current method may include removing the further cooled compressed air ( 115 ) and compressing it in either one cold compressor ( 124 ) or two cold compressors in series ( 124 , 126 ); or the current method may include removing the second cold compressed air stream ( 109 ) and compressing it in either one cold compressor ( 110 ) or two cold compressors in series ( 110 , 123 ). Hence, in various embodiments, there may be between one cold compressor and four cold compressors in any possible combination. Illustrative embodiments follow.
[0016] The method includes performing at least one of steps e) and f). Step e) includes compressing at least a portion of the further cooled compressed air by a first cold compressor ( 124 ), or compressing at least a portion of the further cooled compressed air by a first cold compressor ( 124 ) thereby producing a first cold compressor exhaust stream ( 121 ), cooling the first cold compressor exhaust stream in the heat exchanger ( 106 ), thereby producing a first intermediate cooled compressor exhaust stream ( 125 ); introducing the first intermediate cooled compressor exhaust stream into a third cold compressor ( 126 ), in series with the first cold compressor, thereby producing a first exhaust stream ( 121 ). Step f) includes compressing at least a portion of the second cooled compressed air ( 109 ) by a second cold compressor ( 110 ), or compressing at least a portion of the second cooled compressed air ( 109 ) by a second cold compressor ( 110 ) thereby producing a second cold compressor exhaust stream ( 111 ), warming the second cold compressor exhaust stream in the heat exchanger, thereby producing an intermediate warmed compressor exhaust stream ( 112 ); introducing the second warmed compressor exhaust stream into a fourth cold compressor ( 113 ), in series with the second cold compressor, thereby producing a second exhaust stream ( 114 ). The method also includes vaporizing at least part of the stored liquid air stream ( 105 ) in the heat exchanger ( 106 ), thereby producing a first high pressure compressed air stream ( 107 ). The method includes combining the first high pressure compressed air stream ( 107 ), the first exhaust stream ( 121 ) and the second exhaust stream ( 114 ) to form a combined exhaust stream ( 122 ), heating the combined exhaust stream, then expanding the heated combined exhaust stream in an expansion turbine ( 603 ) to produce power.
BRIEF DESCRIPTION OF THE FIGURES
[0017] FIG. 1 illustrates the efficient vaporization of liquid air, in accordance with one embodiment of the present invention.
[0018] FIG. 2 illustrates another arrangement of the cold compressor in the vaporizer block, in accordance with one embodiment of the present invention.
[0019] FIG. 3 illustrates another embodiment of the vaporizer block wherein the cold compression is performed in two compressors in series, in accordance with one embodiment of the present invention.
[0020] FIG. 3 a illustrates another embodiment of the present invention.
[0021] FIG. 3 b illustrates another embodiment of the present invention.
[0022] FIG. 4 illustrates a gas turbine with combined cycle running on compressed air instead of steam.
[0023] FIG. 5 illustrates a liquefaction plant to liquefy air, in accordance with one embodiment of the present invention.
[0024] FIG. 6 illustrates the operation during the peak loads, in accordance with one embodiment of the present invention.
[0025] FIG. 7 illustrates one improvement of the base scheme of FIG. 6 , in accordance with one embodiment of the present invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0026] Illustrative embodiments of the invention are described below. While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the description herein of specific embodiments is not intended to limit the invention to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.
[0027] It will of course be appreciated that in the development of any such actual embodiment, numerous implementation-specific decisions must be made to achieve the developer's specific goals, such as compliance with system-related and business-related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure.
[0028] As used herein, the term “cold compression” means the method of mechanically raising the pressure of a gas stream that is lower in temperature than the ambient level feeds to the cryogenic separation system and returned to the system at a sub ambient temperature or about ambient temperature. The compressor performing the cold compression is called “cold compressor” and can be a single-staged or a multi-staged device.
[0029] The efficient vaporization of liquid air is described in FIG. 1 . Liquid air produced in off-peak periods is stored in tank 101 , which is usually at about atmospheric pressure. During peak loads, liquid air stream 102 is withdrawn from tank 101 to pump 103 and pump 104 to form high pressure liquid air stream 105 . Stream 105 is vaporized and warmed in heat exchanger 106 to form first high pressure compressed air stream 107 , which may be at about 56 bar. A compressed air stream 108 with a molar flow of about 4.3 times higher than the liquid air stream 102 , at about 10.7 bar and about ambient temperature, is fed to exchanger 106 to be cooled down by the refrigeration provided by the vaporizing liquid air stream 105 . Prior to the dew point of air, a second cooled compressed air stream 109 of the cooled air stream 108 is extracted from exchanger 106 , which may be at about −137° C. and fed to second cold compressor 110 which boosted its pressure to about 13 bar to form second cold compressor exhaust stream 111 . Because of compression heat, the temperature of 111 is about −128° C. Stream 111 is then further warmed in exchanger 106 to yield intermediate warmed compressor exhaust stream 112 at about −85° C., which is the compressed by a fourth cold compressor 113 to yield second exhaust stream 114 at about 56 bar and at ambient temperature.
[0030] The remaining portion of the cooled stream 108 is further cooled in exchanger 106 to form further cooled compressed air stream 115 which may be partially condensed. The liquid fraction of stream 115 is quite small at about 6%. After a phase separation in separator 116 , stream 115 at about −164° C. is separated in to a gaseous stream 117 and a liquid stream 118 . Liquid 118 is mixed with the liquid stream 119 of pump 103 to yield stream 120 , which is then pumped to 56 bar by pump 104 to form liquid stream 105 . Stream 117 is compressed by a first cold compressor 124 to 56 bar to form first cold compressor exhaust stream 121 which is then warmed and mixed with the first high pressure compressed air stream from the high pressure liquid air stream 107 to yield exhaust stream 122 at about 56 bar. Therefore, from a liquid air stream 102 and a medium pressure air stream 108 at about 10.7 bar, and with a flow about 4 times larger, the combined stream (about 5 times larger than liquid air flow) is compressed to 56 bar with minimal power input from the 3 cold compressors. It is useful to note that the total power of the cold compressors represents only 34% of the energy required to compress the combined stream from 10.7 bar to 56 bar. It can be seen from this numerical example that the energy contained in the liquid can be restored efficiently by producing a much higher flow gas stream a pressure with approximately a pressure ratio of 5.
[0031] To simplify the next description, the system of pumps, cold compressors, exchangers etc. are grouped in a “vaporizer block” 123 as shown in FIG. 1 . FIG. 2 describes another arrangement of the cold compressor in the vaporizer block 123 . In the interest of clarity, the element numbers are consistent with those used in FIG. 1 . In this case, if the final pressure of the vaporized liquid air is high enough (about 200 bar abs), the discharge flow 121 of first cold compressor 124 can be at about ambient and there is no need to send it through exchanger 106 . Stream 121 rejoins the vaporized liquid air 107 to form the combined exhaust stream 122 .
[0032] FIG. 3 is another embodiment of the vaporizer block 123 . In the interest of clarity, the common element numbers are consistent with those used in FIG. 1 . In this case, the cold compression of stream 117 is performed in 2 compressors in series. The discharge flow 121 of first cold compressor 124 is cooled in exchanger 106 to form first intermediate cooled compressor exhaust stream 125 which is then compressed further in a third cold compressor 126 to the final pressure. Prior to the dew point of air, a portion 112 of the cooled air stream 108 is extracted from exchanger 106 and fed to second cold compressor 110 which boosted its pressure to the final pressure exhaust stream 114 . First exhaust stream 127 at the outlet of third cold compressor 126 rejoins the warmed vaporized liquid air and stream 114 to form the combined exhaust stream 122 .
[0033] The embodiment described in FIG. 3 a can be used at lower pressure level than the other embodiments. Cooled air 117 is cold compressed in a multi-staged compressor 124 . Stream 126 is extracted at an interstage of compressor 124 , warmed in exchanger 126 and further compressed in compressor 125 to the required pressure. Feed air 108 can be at about 6.5 bar, after cooling it is compressed to about 83 bar in compressor 124 with side stream 126 extracted at about 42 bar.
[0034] In another embodiment described in FIG. 3 b , the vaporized liquid can be separated from the compressed air cycle and extracted from the system as a pressurized product. Indeed, in many applications such as back-up vaporization, or peak shaving vaporization wherein the liquid product is vaporized to complement a gaseous production or to continue supplying gaseous product in case of outages. In this embodiment, the liquid 102 from storage tank 101 can be of liquid oxygen, liquid nitrogen or some other cryogenic liquids. This liquid is sent to exchanger 106 for vaporization as in other embodiments, however, this vaporization circuit is kept separated from the compressed air circuit such that the vaporized liquid product can be extracted from the system to supply a gas demand. Such compressed air circuit is then sustained by a closed loop air circuit driven by the recycle compressor as previously described. It is also feasible to replace air of the closed loop circuit with another gas such as nitrogen, argon, helium, or a mixture of gases for example. As such the refrigeration contained in the cryogenic liquid can be recovered and integrated into the energy storage concept even though the molecules of the stored gas are not subjected to the power recovery by expansion.
[0035] FIG. 4 describes a gas turbine with combined cycle running on compressed air instead of steam. In the interest of clarity, the common element numbers are consistent with those used in FIG. 1 . In this case, atmospheric air 401 is compressed by the compressor 402 of the gas turbine to form a pressurized air 403 , which is then mixed with fuel 404 and combusted in combustion chamber 405 to produce hot gas 406 . Stream 406 at about 1200° C. and at a pressure of about 17 bar is then expanded in turbine 407 . The net power produced by this gas turbine is used to drive a generator 408 . The exhaust gas 409 of turbine 407 at about atmospheric pressure and 580° C. is sent to a heat recovery exchanger 410 . A closed loop of compressed air is circulated by an isothermal compressor 411 . Compression heat can be removed by, for example, cooling water or air cooling. Air stream 412 of about 50-60 bar from compressor 411 is first heated in heat exchanger 413 to yield heated air 414 which is then further heated in heat exchanger 410 , be recovering the heat from the exhaust 409 of the gas turbine, to produce a hot compressed air stream 416 . Stream 416 can then be expanded in a hot gas expander 417 to a pressure of about 10-11 bar to recover the energy. Expander 417 can drive a generator 418 to produce power. Exhaust 419 of expander 417 is sent to exchanger 413 wherein it exchanges heat with stream 412 to yield a returned compressed air stream 108 , which is then re-compressed by compressor 411 to complete the loop.
[0036] The thermal efficiency of the compressed air combined cycle as described in FIG. 4 is marginally better (about 1-2%) than the simple cycle gas turbine. The efficiency of this compressed air combined cycle is much lower than the steam combined cycle by about 10%. Of course, the cost of the steam combined cycle is much higher. However, the compressed air combined cycle has a distinct advantage over the steam combine cycle because it can be improved significantly by integrating with a vaporizer block running with liquid air. This improvement is described in the following paragraphs.
[0037] As mentioned above, power during off-peaks is abundant and can be quite inexpensive. This power can be used to drive a liquefaction plant to liquefy air. FIG. 5 shows such an arrangement. In the interest of clarity, the common element numbers are consistent with those used in FIG. 1 and FIG. 4 . In this case, during off-peaks, the gas turbine's power is not needed and it can be shutdown (equipment shown in dotted line). The isothermal compressor 411 of the compressed air combined cycle can be used as recycle compressor for the liquefaction plant. Atmospheric air 501 is compressed by compressor 502 and cleaned in the adsorber 503 for water and CO2 removal. Clean and dry air 504 from adsorber 503 is admitted into the recycle loop and further compressed by compressor 411 to yield the high pressure air stream 505 . Stream 505 is sent to a liquefier unit 506 , which can be of traditional design and equipped with turbo expander-compressor machinery, to produce a liquid air stream 507 . Liquid air 507 is stored in storage tank 101 .
[0038] FIG. 6 describes the operation during the peak loads. In the interest of clarity, the common element numbers are consistent with those used in FIG. 1 and FIG. 4 . In this case, liquid air 102 (produced in off-peak periods) from storage tank 101 is sent to vaporizer block 123 wherein it is combined with the returned stream 108 at 10.7 bar to yield the final compressed air stream 122 at about 56 bar, as described above. The final compressed air stream is then heated in exchangers 413 and 410 to form the hot compressed air stream 416 which is expanded in hot gas expander 417 to produce additional power. A portion 601 of the expanded gas stream 419 of expander 417 , with a flow essentially the same as the liquid air flow 102 , is reheated in exchanger 410 against the expander 407 's exhaust gas to form a second hot gas stream 602 which is then expanded in a second hot gas expander 603 to produce additional power. The remaining portion 604 of stream 419 is cooled in exchanger 413 and returned to the vaporizer block 123 to complete the loop. The isothermal compressor 411 needed during the off-peak liquefaction or during the normal combined cycle mode can be shut down during the peak loads.
[0039] It can be seen that by vaporizing liquid air via the vaporizer block, additional air flow can be generated efficiently and can be used to recover the waste heat of the gas turbine's exhaust stream and to drive additional hot gas expanders for producing more power. This operation can be performed very quickly to respond to the demand changes of the grid. Since only low power input is needed for the cold compressors of the vaporizer block during peak loads, and none for the liquid production, a large fraction of this increase in power production can be fed to the power grid to boost the electricity output. And this without the high cost and slow response of the steam combined cycle. Such arrangement will complement nicely the simple cycle gas turbine setup.
[0040] The embodiment of FIG. 7 is an improvement of the base scheme of FIG. 6 . In the interest of clarity, the common element numbers are consistent with those used in FIGS. 1 , 4 , and 6 . In this case, the final compressed air stream 122 from the vaporizer block 123 can be divided into 2 portions. Portion 701 is sent to a first combined cycle section wherein it is heated in exchangers 702 and 703 to yield a first hot gas stream 704 which is expanded in expander 705 to recover the power. Exhaust 706 of expander 705 is sent to exchanger 702 for heat recovery and yields a first portion 707 of the returned stream 108 . Portion 708 of the final compressed air stream 122 is sent to a second combined cycle, in series with the first combine cycle. Hot exhaust gas 409 of gas turbine 407 is cooled in exchanger 703 after exchanging heat with the first combined cycle. Its temperature is still high and its heat content can be further recovered in the second combined cycle. Stream 708 is heated in exchangers 413 and 410 to yield a second hot gas stream 416 which is expanded in hot gas expander 417 for power recovery. Exhaust gas 419 of expander 417 is divided into 2 portions: the first portion 601 , with a flow essentially the same as the liquid air flow 102 , is heated in exchanger 410 to yield a third hot gas stream 602 , which is expanded in expander 603 for power recovery. The second portion 604 of stream 419 is sent to exchanger 413 for heat recovery and constitutes the second portion 709 of the returned stream 108 . Hence, the heat exchangers that are indirectly exchanging heat with the gas turbine exhaust ( 703 , 410 ) are in series on the hot side, and they are in parallel on the air side. The heat exchangers ( 702 , 413 ) are in parallel. This embodiment can be used to extract more heat from the exhaust gas of the gas turbine and to further increase the power generation of the system.
[0041] It can be seen from the above description of all three embodiments of the FIGS. 1 , 2 and 3 that almost the totality of heat provided for the vaporization of the liquid air comes from the heat of compression of the cold compressors. The heat input of the liquid air pumps is rather small and only represents about 3% of the total power or heat input. The embodiments of the invention all share this vaporization by cold compression's heat as the common feature, which differentiates this invention from the prior art.
[0042] It should be noted that while the invention has been described in several different embodiments, it is obvious that some additional embodiments can be developed or added by the persons skilled in the art or familiar with the technology to further improve the invention without departing from the scope of this disclosure. For example, a portion of the compressed air from the compressed air combined cycle loop can be injected into the gas turbine and heated by the combustion of air and fuel to form a hot gas then expanded in the gas turbine to generate power. | A method of liquid air energy storage is provided. This method includes liquefying and storing air to form a stored liquid air during a first period of time; during a second period of time, introducing a compressed air stream into a cryogenic system, wherein the cryogenic system comprises at least one cold compressor, and at least one heat exchanger. The method includes producing a first exhaust stream and a second exhaust stream. The method also includes vaporizing at least part of the stored liquid air stream in the heat exchanger, thereby producing a first high pressure compressed air stream, then combining the first high pressure compressed air stream, the first exhaust stream and the second exhaust stream to form a combined exhaust stream, heating the combined exhaust stream, then expanding the heated combined exhaust stream in an expansion turbine to produce power. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This is a continuation application of U.S. Ser. No. 11/865,436, filed Oct. 1, 2007, which is a divisional application of U.S. Ser. No. 11/365,366, filed Mar. 1, 2006, now U.S. Pat. No. 7,331,796, issued Feb. 19, 2008, which claims benefit of U.S. Ser. No. 60/715,261, filed Sep. 8, 2005.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
This invention was made with United States Government support under Contract No. NBCH3039004, DARPA, awarded by the Defense, Advanced Research Projects Agency; whereby the United States Government has certain rights in this invention.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the provision of novel and unique Land Grid Array (LGA) interposers, which incorporate the structure of metal-on-elastomer hemi-torus and other geometrically configured electric contacts to facilitate an array of interconnections between diverse electrical components. The invention is further concerned with a method of producing the inventive LGA interposers.
Land Grid Array (LGA) interposers, by way of example, provide an array of interconnections between a printed wiring board (PWB) and a chip module, such as a Multi-Chip Module (MCM), among other kinds of electrical or electronic devices. LGA interposers allow connections to be made in a way which is reversible and do not require soldering as, for instance, in ball grid arrays and column grid arrays. Ball grid arrays are deemed to be somewhat unreliable on larger areas because the lateral thermal coefficients of expansion driven stresses that develop exceed the ball grid array strength. Column grid arrays hold together despite the stresses but are soldered solutions and, thus, do not allow for field replaceability, which is important because it saves the customer or user significant costs in the maintenance and upgrading of high-end computers for which LGAs are typically used.
2. Discussion of the Prior Art
The basic concept of utilizing LGA interposers to provide an array of electrical connections is well known in the technology. In this connection, reference may be made in particular to Hougham, et al., U.S. Patent Publication No. 2005/0106902 A1, which is commonly assigned to the assignee of this application, and the disclosure of which is incorporated herein by reference in its entirety. This publication describes LGA interposers which define structure consisting of metal-on-elastomer type electrical contacts, wherein a compliant contact consists of an elastomeric material structural element partially coated with an electrically conductive material, preferably such as a metal, so as to form the intended electrical contact. However, there is no disclosure nor suggestion of a compliant contact of an LGA interposer type providing multiple points of electrical contact for each gridpoint in a configuration, such as is uniquely provided by the present invention.
Johnescu, et al., U.S. Patent Publication No. 2005/0124189 A1 discloses an LGA-BGA (Land Grid Array-Ball Grid Array) connector housing and electrical contacts which, however, do not in any manner disclose the novel and inventive LGA interposer metal-on-elastomer structure as provided for herein.
Similarly, DelPrete, et al., U.S. Pat. Nos. 6,790,057 B2 and 6,796,810 B2; and Goodwin, et al., U.S. Pat. No. 6,293,810 B2, describe various types of elastomeric electrical contact systems and devices which, however, do not at all disclose the features and concept of the present inventive metal-on-elastomer LGA interposers and arrays pursuant to the present invention.
SUMMARY OF THE INVENTION
Metal-on-elastomer type LGA contacts, as described hereinabove, have been previously described in Hougham, et al. in which a compliant contact consists of a structural element of a non-conductive elastomer that is coated on a part of its surface with electrically conductive material, which resultingly forms the electrical connection. However, a compliant contact with multiple points of electrical contact for each gridpoint is only disclosed by the present invention, wherein several specific geometries and variants are also described. Among these, a hemi-torus shaped element, such as being similar in shape to one-half of a sliced donut in transverse cross-section) may be oriented concentrically with respect to a via (or proximate thereto), the latter of which passes through an insulating carrier plane to the other side thereof. Metal is deposited onto the external portions of the hemi-toroidal elastomer element in order to form a multiplicity of electrically conductive contacts.
There are two general instances of LGA interconnects made with hemi-toroidally shaped, or other kinds of structural contact elements constituted of elastomeric materials. In the first instance, holes or vias in an insulating carrier plane would first be filled with metal to form solid electrically conducting vias with a surrounding pad or dogbone pad. Onto these pads would be molded both top and bottom elastomeric LGA bodies possessing various shapes, for example, hemi-toroidal. Then in a final step, metal strips would be deposited from the via pad on each side up and over the apex or uppermost ridge of the elastomeric hemi-torus. As illustrated in the drawings, this would then form a continuous electrical path from the highest point on the top hemi-torus shape to the lowest point on the bottom hemi-torus shape at several points for an individual I/O.
In the second instance, the insulating carrier is initially unmetallized with open holes on the desired grid pitch. Then, the top and bottom elastomeric bodies, for instance, hemi-toruses are molded and metallization follows to form the electrically conducting path, as illustrated hereinbelow. In case that during molding, the open hole in the insulator were inadvertently (or purposely) filled with elastomer, (e.g. siloxane), this can be removed in a controlled fashion by a coring or punch step to open a continuous pathway from the top surface to the bottom surface. Metallization can then be deposited on the exposed surface, which is produced thereby in a desired pattern so as to form the electrically conductive pathway.
In addition to the standard two-sided LGA interposer, i.e., on both sides of an insulating carrier phone, a one-sided compliant contact is also generally known in the art, and referred to as a “hybrid” LGA in which the contacts are soldered (ball-grid-array or BGA) to the circuit board but form a compression connection with the module, as in Johnescu, et al., this frequently being referred to as a “hybrid BGA/LGA” or a “hybrid LGA/BGA” interposer.
There are several types of hybrid BGA/LGA's commercially available; however, the present invention describes a new type of hybrid BGA/LGA combining a metal-on-elastomer hemi-toroidally shaped top or upper contact with a solderable (BGA) bottom or lower contact. This provides significant advantages over existing technologies, and examples thereof are presented hereinbelow.
In one preferred embodiment, an insulating carrier plane with regularly spaced through-holes is treated to create a metal pad on top to fill the holes with electrically conducting metal for a through via, and a bottom surface, for example, by electroplating followed by photolithography. This produces a bottom surface with a pad for a BGA connecting to a circuit board. Then molded onto the top surface is a hemi-toroidal shape of an elastomeric material, such as siloxane rubber. The hemi-torus is located concentric to the metal via pad and surrounds it either fully or partly so that the elastomeric inside edge of the hemi-torus either touches the metal via and pad or lies outside the boundary of the via and pad. Then, metal is deposited to form a path of a continuous electrical connection leading from the top of the elastomer hemi-torus to the pad, which connects to the electrically conducting via to the bottom side of the insulating carrier plane creating a continuous conductive pathway from top to bottom. The metal on the elastomer may be distributed over the entire surface, or fabricated to consist of one or more strips connecting the top of the hemi-torus to the via pad. In a preferred embodiment there can be employed three strips, separated by 60 degrees from one another, although other quantities and spacing are shown herein. All of the strips start at the top of the torus, or slightly on the outside edge, and terminate on the pad in the center, this then providing multiple contact points, which is deemed electrically desirable.
Entrapment of air in the center of the hemi-torus is of concern as it could interfere with reliable seating of the electrical contact in compression. This potential concern can be mitigated by forming an opening or venting slit in the side of the torus during or after molding. Alternatively, any concern about entrapped air can be overcome by making the metal strips which extend over the top of the hemi-torus thick enough to extend over the elastomer surface, so that the gap produced between the uncoated area of the hemi-torus and the module bottom when the metal is in contact with the module bottom provides sufficient venting to allow a facile escape of air from the center of the hemi-torus upon actuation
Another advantage to having multiple discontinuities in the hemi-torus shape resides in that each segment with its metal strip contact can move independently and better accommodate or compensate for non-uniformities in the mating surfaces.
The hemi-toroidal shape of the interposer can be molded from a compliant (rubbery) material onto each I/O position in an array, and metal strips are fabricated on the top surface of this shape so that they will provide multiple electrical pathways from a single chip module pad to a single printed circuit board pad. When this compliant hemi-torus is thus metalized, and preferably provided with discontinuities in the donut wall so that air would not be trapped preventing good contact, and provided that the compliant button stays well adhered to the insulating substrate or plane by virtue of anchoring holes, surface roughening, or surface treatments or coatings, then a uniquely functioning LGA is readily produced.
A structure pursuant to the invention possesses another advantage. For modules or PCBs that have solder balls or other protruding conductive structures, the LGA interposer array can be actuated into the module/PCB sandwich without the need for any separate alignment step or alignment structures. The ball will nest in the hemi-torus structure and center and stabilize itself with respect to any lateril motion in the x-y directions.
This provides another advantage which may sometimes be invoked, in that a module, which has had solder balls attached thereto, it in preparation for an ordinary BGA solder reflow step could instead be redirected on the assembly line for utilization in an LGA socket. Thus, a single product number part (balled module) could be used in two separate applications: 1) BGA soldering and 2) LGA socketing.
Such torus structures could be made by molding where the molds are made by drilling or machining with a router-like bit. Alternatively, it could be made by chemically or photoetching of the mold material utilizing a mask in the shape of a torus structure. The mask could be made by photolithography directly on the mold die or could consist of a premade physical mask (such as from molybdenum sheet metal) that was separately formed by photolithography and then applied to the mold die.
Another embodiment of this invention utilizes a hemi-torus that has been divided into three or four sections, each of which have been metalized to provide separate electrical paths, and whereby each section can respond mechanically independently when contacted with a pad or solder ball and can thus more reliably form a joint. Moreover, preferably a small space between these sections is created to allow gas to escape freely.
Pursuant to yet another embodiment, a number of the divided sections of a single hemi-torus can be made taller to provide a lateral stop for the case when a balled module is loaded preferably from one side thereof
According to another embodiment, a wall shape of the sectionally-divided hemi-torus curves back in and under to form a nest so that when a solder ball is brought into contact therewith, it can be pressed down into the nest and snapped into place, or the shape could be curved simply to best nest a solder ball held in place there against.
As described in another embodiment, the I/O consists of multiple hemi-toroidal conic sections or domes that are fabricated into a group to service a single I/O. Each of these domes is metalized separately so that when contact is made with a module pad, redundant electrical paths are formed. The different contacts can also act independently mechanically thus being better able to accommodate local non-uniformities. A further modification would be to make a portion of the hemi-toroidal domes in such a group higher in the z-direction, thus providing a mechanical stop for cases where a balled module is loaded in part from one side, and thus able to constitute an alignment feature.
In the above embodiments, the structures and methods described can be applied to either single sided compliant LGAs (aka hybrid LGA), i.e., on one side of the carrier plane only, or to double sided LGAs. Further, they can be applied to hybrid cases where the corresponding metal pad is either directly in line with the center axis of the upper contact or may be offset therefrom:
As shown in another embodiment, the compliant structures are in a linear form rather than based on a torus or groups of domes. From a linear compliant bar, or alternatively a sectioned bar, multiple contact strips can be formed for each I/O. Further, the multiple metal contact strips could be located on different linear bars for a given I/O. Various arrangements could include multiple metal strips on the same linear section of compliant material, or on different adjacent linear bars in a line, or on different linear bars on either side of the central I/O via
BRIEF DESCRIPTION OF THE DRAWINGS
Reference may now be made to the following detailed description of preferred embodiments of the invention, taken in conjunction with the accompanying drawings; in which:
FIG. 1 illustrates generally diagrammatically, a metal-on-elastomer LGA interposer array, shown in a transverse sectional view, pursuant to a first embodiment of the invention;
FIG. 2A illustrates a modified embodiment of the metal-on-elastomer LGA interposers, shown in a transverse enlarged sectional view;
FIG. 2B illustrates a perspective view of the LGA interposer array of FIG. 2A ;
FIG. 3 illustrates a perspective view of metal-on-elastomer LGA interposers;
FIG. 4 illustrates a transverse enlarged cross-sectional view of the LGA interposers of FIG. 3 ;
FIG. 5 illustrates a perspective view of a further embodiment of an LGA interposer array;
FIG. 6 illustrates a transverse enlarged cross-sectional view of the interposer array of FIG. 5 ;
FIG. 7 illustrates a perspective view of a further embodiment of a metal-on-elastomer LGA interposer array;
FIG. 8 illustrates a transverse enlarged cross-sectional view of the LGA interposer array of FIG. 7 ;
FIG. 9 illustrates a perspective view of a still further embodiment of a metal-on-elastomer LGA interposer array;
FIG. 10 illustrates a perspective view of a further embodiment of an LGA interposer array, which is similar to that illustrated in FIG. 7 ;
FIG. 11 illustrates a further embodiment in a perspective view of an LGA interposer array showing a modification relative to that shown in FIG. 10 ;
FIG. 12 illustrates a perspective representation of a further LGA interposer array, which is somewhat similar to that of FIG. 10 ;
FIG. 13 illustrates a transverse enlarged cross-sectional view of the LGA interposer array of FIG. 12 ;
FIG. 14 illustrates a perspective view of a further embodiment of an LGA interposer array,
FIG. 15 illustrates a transverse enlarged cross-sectional view of a portion of the LGA interposer array of FIG. 14 ;
FIG. 16 illustrates a transverse enlarged cross-sectional view of an embodiment which is somewhat similar to that of FIG. 14 ;
FIG. 17 illustrates a perspective view of a further embodiment of an LGA interposer array,
FIG. 18 illustrates a transverse enlarged cross-sectional view of the LGA interposer array of FIG. 17 ;
FIG. 19 illustrates a perspective view of a modified embodiment of the LGA interposer array, relative to that shown in FIG. 17 ;
FIG. 20 illustrates a transverse enlarged cross-sectional view of a portion of the LGA interposer array of FIG. 19 ;
FIG. 21 illustrates a modified arrangement consisting of linear bars of metal-on-elastomer contacts shown in a perspective representation;
FIG. 22 illustrates a transverse enlarged cross-sectional view of a portion of the LGA interposer arrangement of FIG. 21 ; and
FIGS. 23-25 illustrate, respectively, alternative-processing concepts for providing the LGA interposer arrays in accordance with various of the embodiments described hereinabove.
DETAILED DESCRIPTION OF THE INVENTION
In the detailed description of the various embodiments, elements or components, which are substantially similar or identical, are designated with the same reference numerals.
Referring to the embodiment of the metal-on-elastomer LGA interposer array 10 , as illustrated in FIG. 1 of the drawings, there are shown a plurality of the interposers 12 in the form of hemi-toroidally shaped elements or so called buttons (generally simulating the shape of a transversely sliced donut). Each of the LGA interposer buttons 12 includes a plurality of circumferentially spaced flexible strip-like metal elements 14 forming electrical contacts which reach from the topmost surface 16 of each respective LGA button 12 to the via 18 which extends through an insulating carrier pad 20 on which the LGA interposer buttons are mounted, and down through the center of the LGA buttons so as to connect to a conductive pad 22 which surrounds through the through via on both sides of the carrier 20 , and extends out along the insulating carrier surface beneath the LGA so as to make electrical contact at the other side or the lowermost end surface 24 of the inversely positioned lower LGA interposer buttons 26 . The electrically-conductive flexible metal elements are primarily strips 14 which extend from the uppermost end of the respective upper LGA interposer buttons 12 inwardly into an essentially cup shaped portion extending to the hole or via 18 formed in the pad 22 .
Consequently, by means of the pads 22 , which are constituted of electrically conductive material or metal and which surround each of the through vias 18 formed in the dielectric material insulating carrier plane 20 , these contact the ends of each of the metal strips 14 , which extend along the external elastomeric material surface of each respective LGA hemi-toroidally shaped interposer structure or button 12 . Accordingly, electrical contact is made from the uppermost or top end of each respective LGA interposer button to the lowermost end 24 of each of the opposite sided LGA interposer buttons 26 at the opposite or lower side of the insulating carrier plane 20 .
With regard to the embodiment illustrated in FIG. 2A of the drawings, wherein the electrical elements 30 consisting of the strips positioned on the top surface 16 of the respective LGA interposer buttons 12 extend towards the through via 18 , in this instance, there is no electrically conductive pad present as in FIG. 1 , but rather the metallic or electrically conductive strips 30 forming the flexible metal contacts extend from the uppermost end 16 of the upper LGA interposer buttons 12 down through the via 18 , the insulating carrier plane 20 to the lowermost ends or apices 24 of the lower inverted LGA buttons 26 on the opposite or bottom side of the structure 10 .
In essence, in both embodiments, in FIGS. 1 and 2A , both the upper and lower LGA interposer buttons 12 , 26 are mirror images and are symmetrical relative to each other on opposite sides of the insulating carrier plane 20 . With regard to FIG. 2B of the drawings, this illustrates primarily a perspective representation of the array of the upper LGA interposer buttons 12 positioned on the insulating carrier plane 20 .
Reverting to the embodiment of FIG. 3 of the drawings, in this instance, the flexible metal electrical contacts 34 , which are positioned so as to extend from the upper ends 16 of each of the respective LGA interposer buttons 12 through the via 18 in the insulating carrier plane 20 , as also represented in the cross-sectional view of FIG. 4 , are designed to have the electrical metal contacts forming a plurality of flexible strips 34 , which extend each unitarily from the upper ends 16 to the lower ends 24 of the hemi-torus shaped buttons 12 , 26 from above and below the insulating carrier plane 20 in a mirror-image arrangement. Hereby, the multiple, circumferentially spaced metal electrical contact strips 34 extend from the uppermost point on one side of the insulating plane to the lowermost point on the opposite side so as to form electrical through-connections at both upper and lower ends and, in effect, forming a reversible structure 10 .
As shown in FIG. 5 of the drawings, in that instance, each of the hemi-toroidally shaped interposer buttons 12 , 26 , which are essentially identical in construction with those shown in FIGS. 3 and 4 of the drawings, have the metal contacts 40 formed so that they extend in a common annular conductive sleeve structure 42 prior to continuing through the via 18 , which is formed in the insulating carrier plane 20 to the upper and lower ends 16 , 26 of the LGA interposer buttons 24 . In FIG. 6 of the drawings, these contacts 40 separate only into separated strip-like portions 42 at the extreme uppermost and lowermost ends of the LGA interposer buttons 12 , 26 and then join together into the essentially annular structure 44 extending through the via 18 formed in the insulating carrier plane 20 .
Referring to the embodiment of FIGS. 7 and 8 of the drawings, these illustrate essentially a structure 50 wherein LGA interposer buttons 12 are arranged only on the upper surface 52 of the insulating carrier plane 20 in a manner similar to FIG. 1 of the drawings, and wherein the conductive strips 14 contact metallic or electrically-conductive pads 54 extending respectively through each of the through vias 18 formed in the insulating carrier plane 20 . The lower surface of each metal pad 54 , in turn, may have a solder ball 56 attached thereto in preparation for a subsequent joining, as is known in the technology.
As shown in the perspective representation of FIG. 9 of the drawings, in that instance, the LGA interposer array structure 60 , which is mounted on the insulating carrier plane 20 , is similar to that shown in FIGS. 7 and 8 of the drawings; however, a slit 62 is formed in the elastomeric material of each LGA interposer button 12 , communicating with the interior 64 thereof, and with the through via 18 , which is formed in the insulating carrier plane 20 , so as to enable any gasses or pressure generated to vent from the interior thereof to the surroundings.
FIG. 10 of the drawings is also similar to the structure shown in FIG. 7 , however, in this instance, each elastomeric interposer button 12 has a plurality of slits 62 or discontinuities formed in the annular toroidally-shaped walls thereof, preferably intermediate respective flexible metal strips 14 , which are located on the upper and inward downwardly extending surface of each elastomer buttons, so as to enable each separate segment 68 to be able to resiliently or flexibly respond to changes or irregularities in the topography of elements contacting the LGA interposer buttons 12 . Also, each segment 68 between each of respective metal contact strips 14 may respond mechanically or independently, so as not to only accommodate differences in topography with a mating surface or differences in the shape of mating solder balls, but in cases where a solder ball will be pressed against the toroidal contacts to produce an electrical connection. In effect, this will enable a mechanical or physical compensation for encountered differences in contact surfaces.
With regard to the embodiment of FIG. 11 of the drawings, which is somewhat similar to FIG. 10 , in that instance, at least one or more of the segments 68 , which are separated by the intermediate slits extending through the LGA interposer buttons are different in height, so as to have some of the segments 70 higher than others in a z- or vertical direction relative to the plane of the insulating carrier plane 20 . In this instance, two segments 68 of the four independent segments of each respective LGA interposer button 12 are shown to be lower in height than the other segments 70 .
With regard to FIG. 12 of the drawings, in this instance, the array structure 74 of the hemi-toroidal LGA interposer buttons 76 , which are mounted on the insulating carrier plane 20 , the opposite or lower side 78 of which has solder balls 80 connected to electrically-conductive pads 82 extending through the vias 18 , has the centers 84 of the respective LGA interposer buttons 76 , which have electrical strip-like contacts 88 extending downwardly, as shown in FIG. 13 , have a contoured inner wall configuration 90 , which allows for nesting or a snap-fit with a solder ball (not shown), which may be brought into engagement therewith. In this instance, FIG. 13 showing the cross-sectional representation of FIG. 12 , illustrates the knob-shaped interior sidewall profile 90 of the compliant interposer button with the separate metal contact strips 88 extending upwardly along the interior of wall 90 to the topmost end 92 of each respective LGA interposer button 76 .
As illustrated in the embodiment of FIG. 14 of the drawings, in this instance, as also shown in cross-section in FIG. 15 ; multiple metal strip contacts 88 extend from the top surfaces of the compliant LGA button structure 100 , passing over the top surfaces 102 and extending down into the center part of the hole 104 provided in each interposer button 106 , and meeting with a common pad-shaped metal conductor 108 , which extends along the upper surface 110 of the insulating carrier plane 20 under the button in contact with strips 88 and outwardly until reaching a via 112 , which extends the metal pad downwardly through the insulating carrier plane 20 and along the lower surface 114 thereof, so as to contact solder balls 116 . This is illustrated in the cross-sectional representation of FIG. 15 of the drawings, which also shows a filled injection tube 120 extending through the insulating carrier plane 20 and a residue break off point 122 , where an elastomer portion was separated from an injection port on a mold forming the entire LGA button structure. This embodiment, showing the filled injection tube for the plastic material, is adapted for the method in which the injection molding of elastomeric material is implemented from the bottom side of the insulating carrier plane 20 .
As shown in FIG. 16 of the drawings, which is essentially similar to the embodiment of FIG. 15 , in that instance, this illustrates a filler injection tube, the mold (not shown) forming the LGA button structure is implemented by injection molding from the top side of the mold, and a residual mass of elastomer 132 can be ascertained extending from the side 134 of the elastic LGA button structure 100 from which it was separated at the injection port of a mold.
Also indicated in FIG. 16 are two types of anchoring holes in the insulating carrier plane 20 , wherein one hole 136 extends all the way through to the other side thereof, and wherein a blob 138 of residual excess molding material penetrates slightly beyond the bottom surface of the insulating carrier plane 20 . Another type of anchoring hole or cavity 140 does not extend fully through the insulating carrier plane 20 , but is formed as a depression in the top surface of the latter, so as to mechanically anchor the elastomeric material of each LGA interposer button to the structure or plane 20 .
Reverting to the embodiment of FIGS. 17 and 18 of the drawings, these show another aspect of providing an LGA interposer array 150 on an insulating carrier plane 20 , wherein a multiple of LGA interposer buttons 152 of essentially conical configurations and their electrical metallic strip contacts 154 , which extend over the topmost ends 156 thereof, service a common I/O electrical contact 158 in the form of a pad on the upper surface of plane 20 . In this instance, the structure incorporates an electrically conductive via 160 extending through the insulating carrier plane 20 , shown in a center of a group of four LGA interposer buttons 102 , as a common meeting point of the metal contact strips 154 on pad 158 , which extend from respectively one each of the top of each LGA button down the side thereof and into the via metallurgy of the structure, towards the bottom of plane 20 , as shown in cross-section in FIG. 18 of the drawings.
Reverting to the embodiment of FIGS. 19 and 20 of the drawings, which is quite similar to the embodiment of FIGS. 17 and 18 , in that instance, the primary distinction resides in that at least one or two of the LGA interposer buttons 152 of a respective group thereof has or have a height which differs from the remaining interposer buttons of that group. For example, two or more buttons 152 of each group may be taller than the remaining buttons 164 of that group (of four buttons) in order to essentially create a lateral stop mechanism for a side loading of a module, through such groupings of LGA interposer buttons in respective arrays. In essence, the different heights in the LGA interposer button groups enable a module with an associated solder ball to be brought into contact and aligned by means of lateral insertion, rather than only vertical insertion, wherein the higher LGA interposer buttons provide stops for the solder balls in order to register with the essentially hemi-toroidally shaped elastomeric contacts.
Reverting to the embodiment of FIGS. 21 and 22 of the drawings, in this instance, there is provided an LGA interposer array 170 arranged on an insulating carrier plane 20 , wherein multiple points of contact for each I/O are provided by means of linear bars of elastomeric LGA interposers 172 . This provides a compliant structure on which a plurality of spaced metallic electrical contact strip elements 174 may be positioned so as to extend from the top 176 of each respective interposer bar 172 both above and below the insulating carrier plane 20 , as shown in FIG. 22 , into electrically sleeve-like conductive vias 178 formed extending through the insulating carrier plane 20 in contact with respective metal strip contacts 180 above and below the insulating carrier plane 20 . In that instance, the metal contact strips 180 may be formed with different shapes, such as one typical contact joining from two separate ships 182 into a single common strip 184 near the top, as clearly illustrated in FIG. 21 , or joining further down near the via extending through the carrier plane to the other side. Furthermore, three or more contact points for each I/O may be provided and different types of contact elements may be utilized along the bar whereby some types may be more suitable for conduction of signals and others for high amperage power feeds.
As illustrated in FIGS. 23-25 , there are shown alternate process flows for a balled module, wherein a balled module zoo, as shown in FIG. 23 , can be directed either towards a solder reflow line for normal BGA connection to a PWB, as illustrated in FIG. 24 , or alternatively, to an LGA interposer assembly 210 where it is assembled by means of a hemi-toroidal LGA and PWB (wiring board) under pressure to make a field replaceable unit, as shown in FIG. 25 of the drawings.
With regard to the configurations of the LGA interposer buttons, these may be of elastic structural members, which are conical, dome-shaped conic sections or other positive release shapes, such as roughly cylindrical or hemispherical, hemi-toroids, and wherein the metal coating forming the electrically conductive contact members or strips terminate at the apices of each of the multiple buttons.
Moreover, the elastomeric material, which is utilized for each of the LGA interposer buttons or for the linear shaped elastic structural member (as shown in FIGS. 21 and 22 ) may be constituted of any suitable molded polymer from any rubber-like moldable composition, which, for example, among others, may consist of silicon rubber, also known as siloxane or PDMS, polyurethane, polybutadiene and its copolymers, polystyrene and its copolymers, acrylonitrile and its copolymers and epoxides and its copolymers.
The connectors of the inventive LGA structure may be injection molded or transfer molded onto an insulating carrier plane 20 , and may serve the purpose of mechanically anchoring the contact to the insulating carrier plane and in instances can provide a conduit for the electrical connections which pass from the top surface of the connector to the bottom surface thereof.
In addition to connecting chip modules to printed circuit boards, the arrays of the LGA interposer buttons or linear structure may be employed for chip-to-chip connection in chip stacking or for board to board connections, the contacts may be of any shape and produced by injecting the elastomer in the same side as where the elastomer contact will be anchored to the insulating carrier by a hole or holes or vias, which extend through the insulating carrier or by any cavity edge formed into the surface of the insulating carrier.
In essence, the molding of the elastomeric material component or components, such as the hemi-toroidal interposer or interposers may be implemented in that the elastomeric polymer material is ejected from the same side at which the interposer will be positioned on the insulating carrier plane, and will be anchored to the insulating carrier plane by means of a hole or holes, as illustrated in the drawings, which either extend completely through to the opposite side of the insulating carrier plane, or through the intermediary of a cavity which is etched or formed into the surface of the insulating carrier plane, which does not extend all the way through the thickness thereof, and wherein any cavity may have flared undercut sidewalls from maximum anchoring ability or by simple surface roughening of the insulating carrier plane. This is clearly illustrated in the embodiments represented in FIGS. 15 and 16 of the drawings.
While the present invention has been particularly shown and described with respect to preferred embodiments thereof, it will be understood by those skilled in the art that the foregoing and other changes in forms and details may be made without departing from the scope and spirit of the present invention. It is therefore intended that the present invention not be limited to the exact forms and details described and illustrated, but fall within the scope of the appended claims. | A land grid array (LGA) interposer structure, including an electrically insulating carrier plane, and interposer groupings of different height being mounted on a first surface of said carrier plane. Each interposer possesses a hemi-toroidal configuration in transverse cross-section and is constituted of a dielectric elastomeric material. A plurality of electrically-conductive elements are arranged about the surface of each hemi-toroidal interposer and extend radically inwardly and downwardly from an uppermost end thereof into electrical contact with at least one component located on an opposite side of the electrically insulating carrier plane. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority to U.S. Provisional Application 61/900,738 filed on Nov. 6, 2013, the complete contents of which is herein incorporated by reference.
FILED OF THE INVENTION
Aspects for the invention relate to a method of producing chemical-treated fibers using a continuous treatment system. In particular, embodiments of the invention pertain to a method of applying chemicals on loose fibers with substantially even chemical distribution. In some embodiments, chemical formulations collected during the process are sent back to the treatment bath and reused (e.g., recycled for the purpose of protecting the environment, reducing costs, etc.)
BACKGROUND
Textile substrates need various chemical treatments depending on the desired properties of the end-uses. Chemical treatment for textile substrates can be done either by batch or continuous process. For a batch process, a specific amount of textile substrate is treated with chemical formulations for a specific period of time. The amount of chemicals used is normally based on the amount of the substrate being treated or on the amount of formulation being used. In general, in batch processes the exact amount of chemical being used is calculated based on either total amount of the textile substrate or formulation, which is expressed as “% owg (on weight of goods)” or “% owb (on weight of bath)”, respectively.
For continuous textile wet processes, textile substrates are treated continuously by being passed through one or more process steps arranged in tandem. Textile substrates pass through a chemical formulation in a treatment bath and the completely soaked substrates pass through a pair of squeeze rolls to remove excess amounts of the formulation in order to control the amount of chemical formulation on the substrates. Then, the substrates continue to pass through a drying (e.g, heating) stage, such as an oven, to remove residual water and to fix the chemicals on the substrates. The amount of chemicals applied on textile substrates depends on the concentration of chemicals in the formulation and the “wet pickup”. Wet pickup is the amount of the chemical formulation picked up by the substrate and is expressed as a percentage on weight of the dry substrate. The wet pickup on the substrate is controlled by the nip pressure of the squeeze rolls. To give uniform chemical distribution throughout or over the substrate, the wet pickup must be controlled evenly across the width and along the length of the substrate.
Most chemical treatments for textile substrates are performed at the “fabric stage” (e.g., a stage where the fabric has already been produced from fibers). However, chemical treatments are also performed at the “fiber stage” (e.g., when chemical-treated fibers are required for yarn spinning or nonwoven production). For a batch process chemical treatment of fibers, a specified amount of loose fibers is loaded in a perforated basket, and the basket is loaded into a chemical treatment device such as a stock dyeing machine. After loading the basket, a specific amount of chemicals is applied on the fibers using the dyeing machine or other chemical treatment device for a specified period of time. In contrast, in a continuous process, the fibers in a web or batt form are continuously passed through one or more process steps arranged in tandem. The wet pickup control for the fibers is difficult in a continuous process when compared to woven fabrics because the thickness of the fiber web (or batt) is generally uneven across the width and along the length.
If, in a continuous process, the fibers were subjected to scouring, bleaching, and rinsing, the fibers will contain only water after final squeezing. In this case, even though there will be a variation of wet pickup on the fibers, this will generally not pose a problem since there will be no remaining chemical on the fibers after drying. In sharp contrast, when the fibers are subjected to chemical formulation treatment, the wet pickup variation will cause uneven chemical distribution throughout the final dried fibers. This will cause an uneven quality (property) on the final products (yarn or nonwoven) made with these fibers.
U.S. Pat. Nos. 4,213,218, 4,425,842, and 4,944,070, each of which are herein incorporated by reference, describe methods of continuous wet finishing for fibers. These applications require the loose fibers to be converted into a web or batt form before the wet treatment. These applications utilize a squeezing system to control final chemical amount on the treated fibers. In operation, the fiber web (or batt) soaked with a chemical formulation is passed through a pair of squeeze rolls. The amount of the chemical formulation picked up by the fibers is controlled by the pressure of the squeeze rolls. However, in practice, the squeezing system does not provide an even chemical distribution on the final treated fiber because the thickness of the fiber web (or batt) squeezed is not even. The thickness of fiber web (or batt) is much less controllable compared to the thickness of woven fabrics.
SUMMARY
The invention pertains to continuous chemical treatment systems for fibers, and particularly provides a process and system for the continuous chemical treatment of loose fibers which ensures substantially uniform chemical distribution on the treated fibers (e.g., the wet pick up of the chemical formulation from fiber to fiber varies by 10% or less, and more preferably 5% or less for wetted fibers; using squeeze alone typically results in variations of 50% or 100% or more).
An embodiment of the invention is to utilize a continuous centrifuge to control chemical formulation wet pickup on the fibers.
Another embodiment of the invention is to recycle the chemical formulation collected from the centrifuge to provide advantages such as lowering production costs and providing a more environmentally friendly process, etc.
Continuous centrifuges are used in many different industries, such as food, fine chemical, pharmaceutical, and textile industry. For example, continuous centrifuges are used in the textile industry to dewater wet textile fibers. The excess amount of water from bleached or dyed loose fibers from a dyeing machine needs to be removed before drying. Normally the amount of water on bleached cotton fibers, for example, is around 200˜400% on weight of the dried fiber. These wet cotton fibers cannot be dried without removing the excess amount of the water. Prior to this invention, continuous centrifuges were used for dewatering, and the present invention allows for control of the application of chemical formulation to fibers.
It has now been demonstrated herein that loose fibers which have been subjected to a chemical treatment bath (e.g., one that applies fire retardant chemicals, antimicrobials, insect repellants, etc., via a spray or soaking operation), can advantageously be passed through a continuous centrifuge to render the fibers to have a substantially even chemical distribution. That is, in the process chemically treated fibers from a chemical treatment bath are fed into an inlet of the centrifuge continuously and the fibers are released from the outlet of the centrifuge continuously have a substantially even chemical distribution within or on the surface of the fibers (e.g., the wet pick up of the chemical formulation from fiber to fiber varies by 10% or less, and more preferably 5% or less). Often, but not always required, the fibers released from the outlet will be dried in a dryer (e.g., oven or other drying apparatus). The processing proposed herein allows for continuous processing of fibers by ensuring application of chemicals on loose fibers with substantially even chemical distribution such that the fibers produced will have substantially uniform properties. In some embodiments, chemical formulations collected during the process are sent back to the treatment bath and reused (e.g., recycled for the purpose of protecting the environment, reducing costs, etc.)
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic flow diagram that shows a continuous chemical treatment system for loose fibers.
DETAILED DESCRIPTION
The process of the present invention is intended to produce chemical-treated fibers in the most efficient and economical way as well as to produce the fibers with uniform quality in terms of chemical distribution on the fibers. An exemplary process which exploits the present invention is illustrated schematically in FIG. 1 .
Fibers are provided at the beginning of the process, for example as a bale form. The fibers can be natural fibers, man-made fibers, or combination of those. Natural fibers include, but are not limited to, cotton, ramie, coir, hemp, abaca, sisal, kapok, jute, flax, linen, kenaf, coconut fiber, pineapple fiber, wool, cashmere, and silk. Man-made fibers include, but are not limited to, polyester, nylon, acrylics, acetate, polyolefins, melamin fibers, elastomeric fibers, polybenzimidazole, aramid fibers, polyimide fibers, modacrylics, polyphenylene sulfide fibers, oxidized PAN fiber, carbon fibers, novoloid fibers, manufactured cellulosic fibers (e.g., rayon, lyocell, bamboo fiber, Tencel®, and Modal®), and manufactured FR cellulosic fibers (e.g., Visil®, Anti-fcell®, Daiwabo's FR Corona® fibers, Anti-frayon®, Sniace's FR rayon, and Lenzing Fr®).
A conventional fiber opener 10 can be used to open a chunk of compact fibers from a bale into a loose fiber form and spread the opened loose fibers 12 on a conveyer belt or other apparatus which carries the fibers to the next step of the process. A fine opener may be used for better opening of the fibers. A continuous layer of the opened loose fibers is moved into and through a treatment bath 14 containing a chemical formulation (one or more chemicals; both aqueous and non-aqueous formulations being a chemical formulation according to the invention; however, water alone (i.e., without one or more chemicals) not constituting a chemical formulation according to the invention) and the fibers are completely soaked by the chemical formulation to produce treated loose fibers. For the fibers that need a longer time to be wet, the chemical formulation may be sprayed on the fibers before immersing them into the chemical formulation in the treatment bath 14 . Spraying may also occur after exit of the fibers from the immersion at the bath 14 . For the fibers that are relatively easy to be wet, exposure to the chemical spray in the system may be enough, and immersion may not be required. In some embodiments, a spraying system may be installed at the treatment bath 14 and the chemical formulation is supplied either from the bath 14 or a chemical formulation preparation tank 20 . When the spraying system is a part of the treatment bath 14 , excess amounts of chemical formulation sprayed on the fibers can be automatically collected in the treatment bath 14 .
During the chemical formulation treatment, the fibers preferably are stationary (i.e., fibers do not move freely in the chemical bath 14 ). One exemplary method to make fibers generally not to be floated or not to be tumbled in the treatment bath 14 is to utilize two perforated conveyer belts to hold fibers during the chemical treatment. In this case, the fibers are held between, for example, two perforated endless conveyer belts. Such a system prevents the fibers from floating in the bath 14 . This is advantageous since lost fibers left in the bath 14 will cause process issues, such as clogging draining system and sticking inside parts of the treatment bath system. The treatment bath 14 preferably includes a temperature control system to provide a specified temperature when exposing the fibers to the chemical formulation. The specified temperature may be varied depending on the requirements of different chemical formulations.
The soaked, treated loose fibers obtained after immersion or spraying or both in the chemical treatment bath 14 are squeezed by passing through a pair of squeeze rolls to remove excess amounts of chemical formulation to prevent dripping of the chemical formulation from the fibers while the fibers move to next step of the process. Preferred wet pickup after the squeeze rolls is around 200˜300%. But it will vary depending on type of fibers. In an environmental friendly embodiment and cost saving, the squeezed chemical formulation is collected into the treatment bath 14 to be reused for the continuous treatment. For this purpose, the squeeze rolls may preferably be a part of the treatment bath 14 and may be located at the end of the treatment bath 14 , so the squeezed chemical formulation is automatically collected into the bath 14 .
Then the squeezed fibers are moved to a continuous centrifuge 16 to remove additional chemical formulation from the fibers, and to control chemical formulation wet pickup on the fibers and to achieve a substantially even chemical distribution within or on the surface of the fibers. At this step, a conventional fiber opener and fiber distributor may be used to supply better opened fibers and controlled amount of fibers to the continuous centrifuge. The centrifugation step controls the final wet pickup of the chemical formulation on the fibers. Preferred wet pickup after the centrifugation is below 100% and more preferably at 50˜80%, but the final target wet pickup can be varied depending on different type of fibers and their liquid absorption characteristics. For continuous centrifugation, the controlled amount of squeezed fibers is fed into an inlet of the centrifuge continuously and centrifuged fibers are released through an outlet of the centrifuge continuously. The centrifuged fibers released from the outlet of the centrifuge will have substantially even chemical distribution (e.g., a variance of the wet pickup of the chemical formulation of less than 10% from fiber to fiber) such that the fibers produced will have substantially uniform properties. The continuous centrifuge system may include a cyclone and a feeder whereby fibers released from the continuous centrifuge are transferred to a cyclone to remove air flow from the fibers such that at the feeder supply a uniform layer of chemical-treated loose fibers is provided to a dryer continuously.
During the continuous centrifugation, extracted chemical formulation from the fibers may be collected and continuously sent to the treatment bath 14 (or a chemical formulation preparation tank 20 ) for reuse. At the same time a fresh chemical formulation from one or more chemical formulation preparation tanks 20 can be continuously supplied to the treatment bath 14 to replenish the depleted amount of the chemical formulation by fiber treatment and to keep a same level of the chemical formulation in the bath 14 .
The fibers released from the outlet of the continuous centrifuge 16 may be transferred to a conventional fiber dryer 18 continuously. This may be accomplished by first passing the released fibers from the centrifuge 16 through a cyclone and a feeder. A drying step advantageously removes residual water from the fibers and may assist in fixing chemicals on the fibers. The dried chemical-treated fibers may then be baled to be sent to further processes, such as yarn spinning or nonwoven production.
Exemplary chemicals which may be used for the treatment include but are not limited to softeners, hydrophilic agents, hydrophobic agents, water/oil repellents, anti-static agents, soil-release agents, spin finishes, flame retardants, antimicrobials, insect-repellents, UV absorbers, odor absorbers, fragrances, etc. In addition, a plurality of different chemicals (e.g., flame retardants and hydrophobic agents) or different types of chemicals within one category (e.g., two or more antimicrobials) could be used in the treatment.
A particular advantage of the present invention from prior art is that it permits continuous fiber treatment to be performed uniformly. That is, by utilizing a continuous centrifuge, the wet pickup of chemical formulation on the fibers is reliably and reproducibly controlled. This system and process provides for more precise control of wet pickup compared to squeezing system employed by the prior art. Also, the present invention does not require converting the fibers into a web or batt form as required in the prior art. That is, simply opened loose fibers can be treated with the system of the present invention.
While the present invention has been described in terms of preferred embodiments, those skilled in the art will recognize that the invention can be practiced with considerable modification within the spirit and scope of the appended claims. | Repeatable and reliable chemical treatment for loose fibers is achieved by spraying or immersing loose fibers in a chemical treatment bath, and continuously moving the soaked fibers through a continuous centrifuge. The continuous centrifuge controls the wet pickup of the chemical formulation on the fibers and assures a substantially even chemical distribution on the centrifuged fibers. The centrifuged fibers may be dried to fix the chemicals in the chemical formulation to the fibers and/or to remove water from the chemical formulation. Recycling of the chemical formulation from the continuous centrifuge allows for the process to be performed more economically and in a more environmentally friendly fashion. | 3 |
FIELD OF THE INVENTION
This invention relates to cardiac pacemakers and other medical devices and, more specifically, apparatus and methods for use in cardiac pacemakers in filtering sensed signals, and more particularly filtering sensed cardiac signals.
BACKGROUND OF THE INVENTION
In many medical device applications, such as cardiac pacemakers, there is a great need for accurate detection of sensed signals, and in particular a need for discriminating or separating out certain portions of sensed signals. For example, dual chamber pacemakers sense spontaneous P-waves from the patient's atrium, in order to determine whether or not to pace the atrium and/or for timing out a synchronous ventricular pace pulse. In many such applications, filtering on the basis of frequency is inadequate, because of the overlap of frequencies in signal portions to be accepted and signal portions to be rejected. Specifically, in a cardiac pacemaker which senses the atrial electrogram (AEGM), it is difficult to separate out the far field R-wave (FFR-wave) from the desired P-wave portion of the signal, due to the overlap of frequencies in the two different signal portions. In processing sensor signals or other sensed physiological signals, the use of frequency response filters, or even switchable frequency response filters, often cannot solve the problem for certain signals and rhythms.
Many different schemes have been proposed for addressing this problem. For example, for the task of screening out the FFR-wave from the atrial signal, various techniques such as sensitivity adjustment, "window" tracking so as to detect at about the time of the expected signal, etc. have been implemented. In addition to linear high pass filters, other approaches to the problem have adaptive finite impulse response filters (AFIR) and the use of hidden Markov models. However, these approaches have not led to significant acceptance in the pacing environment. The best possible solution remains an approved filter which effectively distinguishes the desired wave portion from the undesired portion or portions.
There thus is presented a continuing and substantial problem, particularized for implantable pacemakers, for providing efficient and unambiguous recognition of different wave portions of a sensed cardiac signal, e.g., QRS, T and P-wave portions; and also a need to adapt the filtering capability to different rates, in order to detect the desired signal portions during specific arrhythmias such as ventricular fibrillation (VF), ventricular tachycardia (VT), sinus tachycardia (ST) and super-ventricular-tachycardia (SVT). Further, due to power limitations in implantable devices, there is a need to achieve the needed improvement while minimizing the hardware and the processing involved.
The approach taken in this invention is based on the recognition that even where the frequency spectra of different wave portions overlap, the shapes of the respective wave portions are distinct. Thus, the far field R (FFR) wave, while it has many of the same spectral components as the QRS, is relatively stretched out, or wider in form, due to the propagation of the signal from the ventricle into the atrial chamber where it is sensed by atrial electrodes. This suggests the use of morphological filtering techniques in filtering and detecting the P-wave and filtering out the FFR-wave. Morphological-type filters have been widely used in image processing, but are relatively new in signal processing. This invention is based on adaptation of morphological filtering in real time signal processing of analog signals for use by pacemakers and other implantable medical devices.
SUMMARY OF THE INVENTION
It is an object of this invention to provide new filtering techniques for use in devices such as cardiac pacemakers, and specifically the use of morphological-type filters for reliable discrimination of desired wave portions and rejection of undesired wave portions. For example, in a preferred embodiment of this invention, morphological filtering is used to operate on the sensed atrial signal, or AEGM, so as to reliably detect P-waves while rejecting FFR-wave portions. For this application, the invention provides the P-wave clearly separated out, and with a substantially zero base line.
In a preferred pacemaker embodiment of this invention, the sensed atrial signal from the patient is sampled to get the sampled signal. The sampled signal is passed through a morphological filter, either an analog or digital embodiment. The morphological filter operates on the signal by analyzing successive sets of samples selected to approximate the width of the P-wave, thereby filtering out the P-wave but leaving signal portions lacking a morphological fit, such as the FFR-wave. The signal that has been thus morphologically filtered to suppress the P-wave peak is then subtracted from the sampled signal, leaving the P-wave portion that was morphologically filtered out, and thereby rejecting the wider FFR-wave. While the morphological filter may have an analog, digital optical or hybrid-type embodiment, analog is presently preferred for the pacemaker environment because of lower power requirements. The filter is set to operate on about 5-10 samples at a time, with a sample rate around 1 kHz, for optimum P-wave detection. The filter is preferably open-close for best operation on P-wave peaks, but may also incorporate just the open operation. The template, which is adjustable and/or programmable, is suitably common to both open and close operations, and may use zeros for a majority of the adding or subtracting operations, for circuit simplicity.
In yet another embodiment, plural wave portions of incoming signals, e.g., P-waves and T waves in a pacemaker, can be morphologically operated on with the same template configuration. Thus, FFR-waves, T-waves, QRS-waves and P-waves can be morphologically identified; and different types of tachycardia can be discriminated. Further, the sampling rate is suitably adjusted as a function of detected R-R rate, to optimize morphological filtering of signals that vary widely in frequency, thereby enabling improved tracking of arrhythmias such as ventricular tachycardia (VT) and ventricular fibrillation (VF).
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a block diagram illustrating the primary components of an implantable cardiac pacemaker in accordance with this invention; FIG. 1B is an illustration showing an atrial lead with an atrial electrode positioned in the patient's right atrium, for sensing the AEGM to be operated on in accordance with the principles of this invention.
FIG. 2 is a diagram illustrating an AEGM which has not only a P-wave portion but a pronounced FFR-wave portion.
FIG. 3A is a schematic representation of a morphological dilation operation; FIG. 3B is a schematic representation of a morphological erosion operation;
FIG. 3C shows a close operation, comprising a dilate operation followed by an erode operation; FIG. 3D shows an open operation, comprising an erode operation followed by a dilate operation; and FIG. 3E shows an open-close operation comprising an open operation followed by a close operation.
FIG. 4A shows the effect of an open operation in suppressing peaks, illustrating the signal after erode and also after dilate; FIG. 4B shows the effect of a close operation in suppressing pits, showing the signal after dilate and after erode; FIG. 4C shows a signal with both peaks and pits suppressed after either an open-close operation or a close-open operation.
FIG. 5 is a circuit diagram illustrating the preferred arrangement of this invention for providing P-wave peaks while filtering FFR-wave portions from an AEGM signal.
FIGS. 6A, 6B and 6C are sets of curves for M=3, 7 and 15 respectively, which illustrate the effect of the chosen value of M in the circuit of FIG. 5 for providing an optimum P-wave peak without any FFR-wave.
FIG. 7 is a circuit block diagram showing the manner of automatically adjusting the sample frequency for maintaining optimized filtering conditions as a function of cardiac rate variations.
FIG. 8 is a circuit block diagram illustrating the use of plural morphological filters for operating on different signal portions.
FIG. 9 is a simplified flow diagram illustrating the method of this invention for carrying out morphological operations on the AEGM to provide P-waves and to filter out FFR-waves.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 1A, there is shown a simplified block diagram of the primary components of a pacemaker as can be used in the system and method of this invention. Although a dual chamber pacemaker is illustrated for completeness, it is to be understood that the invention is applicable to single or dual chamber rate responsive pacemakers. A ventricular pace generator is illustrated at 15 for generating and delivering ventricular pace pulses under control of control unit 20, in a known fashion. The ventricular pace pulses are delivered to one or more ventricular electrodes illustrated at 16. Likewise an atrial pace generator is illustrated at 18, which generates atrial pace pulses under control block 20 and delivers the atrial pace pulses to one or more atrial electrodes as illustrated at 19. Sense signals from the ventricular electrode or electrodes are connected to QRS sense amplifier 24 and T-wave sense amplifier 26, the outputs of which are inputted to control block 20 for processing. Likewise, signals detected in the atrium by electrodes 19 are delivered to P-wave sense amplifier 25, the output of which is connected through to control 20.
Control block 20 suitably incorporates a microprocessor with associated software, the software being stored in memory 21, as indicated. Memory 21 may contain RAM and ROM, and the assignment of pacemaker functions can be divided between hardware and software in any desired manner. One or more sensors 26 may be provided to continuously detect rate-indicating parameters, the parameter signals being inputted to control block 24 to provide rate responsive control, in a known manner. Alternately, the rate responsive parameter is QT interval, which is determined by control 20 by timing the duration between a delivered stimulus (VP) and the following T wave. As illustrated at 27, the pacemaker suitably has a transmitter/receiver for receiving programmer communications from an external programmer 30, and for down loading collected data back to the programmer, in a known fashion.
For the preferred analog embodiment of this invention, the morphological filter or filters are part of the circuitry of block 24-26, under control of control circuit 20. For a digital embodiment, the morphological operations are carried out by the microprocessor of block 20.
Referring now to FIG. 1B, there is shown a diagrammatic representation of the chambers of the heart, with an atrial lead 17 inserted into the right atrium so that atrial electrode 19 is positioned within the right atrium. The signal generated by the sino-atrial node is captured by the electrode (or electrodes in a bipolar system), for purposes of providing P-wave information. As is known, the P-wave is extremely important for dual chamber pacemakers, e.g., DDD or VDD, as the timing of the P-wave enables the pacemaker to time out and deliver a synchronous ventricular pace pulse. Also, the P-wave is used in atrial pacemakers, e.g., AAI, or in a DDD pacemaker, to determine whether or not to stimulate the atrium. Referring to FIG. 2, there is shown a typical AEGM captured by an atrial sensing lead. As is known, the pulse generated by the SA-node depolarizes through the atrial chambers and causes the atrial muscles to contract and pump blood into the ventricular chambers. This pulse is referred to as the P-wave, and is represented by the complex indicated by the letter P in FIG. 2. The P-wave is delayed by the AV-node for about 200 ms, after which the propagation of the wave generates the QRS complex in the ventricular chambers. The QRS complex makes the ventricular muscles contract and pump the blood from the ventricles into the arteries. The magnitude of the QRS complex is much greater than that of the P-wave, such that even though the atrial sensing electrode is placed as close as possible to the AV node, a substantial R-peak from the ventricle still appears in this signal. This appearance of the R-peak is referred to as the far field R-wave (FFR), and when sensed in the atrium is clearly a disturbance. However, as stated above, the FFR-wave is hard to discriminate from the P-wave by simply using linear filters, because of the similarity of the power spectral densities of typical P-and FFR-waves.
The morphological filters used in the practice of this invention are constructed from a combination of a morphological operators. Morphological operators use a separate data set to transform a set of input samples to a set of output samples. The set, known as the structuring element (or simply "template") defines the operation that takes place. As seen in connection with FIGS. 3A and 3B, the degree of complexity of morphological filters is relatively low, because only delay lines, additions, subtractions, and maximum- and minimum functions are used.
There are two morphological operations, namely dilation and erosion. Although these operations appear in tandem, they are defined separately. The dilation of a signal X, of length n samples, by a template m, with a template length M, producing an output is defined as
Yd.sub.n =D(X.sub.n)=MAX.sub.i=0 . . . M-1 {X.sub.n-i +m.sub.i }M-1≦n≦N-1
As can be seen, dilation is an expanding operator, meaning that the outputs are always greater than the corresponding inputs, if the template m i is greater than zero for all i. The X n-i term looks back in time, and once the first M-1 samples have passed by, the operation can give an instantaneous output. Morphological filtering can thus be used as a real time application, although it is to be noted that the output set generated by dilation is M-1 samples shorter than the data set, because the first M-1 output samples cannot be defined. Referring to FIG. 3A, the input signal is shown as X, which is passed through successive delays 31, 32, . . . 33 as illustrated. Thus, when the first M-1 samples have been clocked through to taps 31-33, the first M samples are operated on by the addition operations as indicated. The values of m 0 , m 1 , m 2 . . . m M-1 are provided by the dilation template, indicated at 39. In a simple case, the additions may simply be +0. Block 40 is a maximum circuit, which selects the input which has the maximum value, and provides this max value as the sample output. Thus, the maximum value of X n-i +m i is outputted for each value of n, producing the sample set Yd. It can be seen that the dilation produces a set which is M-1 samples shorter than the data set, because the first M-1 output samples cannot be defined.
The erosion of a function X (length N) by a template m with template length M, (Ye), is defined as:
Ye.sub.n =E(X.sub.n)=MIN.sub.i=0 . . . M-1 {X.sub.n+i -m.sub.i }O≦n≦N-M
The erosion operation subtracts, and thus is a shrinking operation, meaning that the outputs are always smaller than the inputs if the template m i is greater than zero for all i. As opposed to the dilation operation, erosion looks ahead in time, as seen by X n+i . Therefore, in a real time application, the erosion circuit must wait until these future samples have passed by, thus causing a delay of M-1 samples, as shown in FIG. 3B. Also, as with dilation, an erosion operation generates an output set M-1 samples shorter than the data set, the difference being that the samples are lost at the end of the set. The input X, which can be provided by connecting the output Yd from the dilate circuit of FIG. 3A, is clocked into the respective taps 42, 43, 44. The subtractions are performed for each sample, by subtractor circuits 45, 46, 47, 48, having m respective template values determined by the erosion template data T E stored as indicated at 49. Circuit 50 examines the results of the subtraction operations, and outputs the minimum sample for each value of n, yielding Y e . As discussed above, and for reasons made clear by the following illustrations, dilation and erosions are generally combined into filters known respectively as open and close filters. As illustrated in FIG. 3C, a close is made up of a dilate circuit 52 followed by an erode circuit 53. As illustrated in FIG. 3D, an open is made up of an erode 53 followed by a dilate circuit 52. Because a dilation and an erosion are combined in either an open or a close, the first M-1 samples are lost by the dilation and the last M-1 samples by the erosion, such that the output set generated by an open or close is 2(M-1) samples shorter than the data set. When constructing either an open or close filter from a dilation and an erosion, both operators can use the same template; however, the template data connected for the erosion operation is the reverse of that for the dilate operation, as can be seen from the equations and from a comparison of FIGS. 3A and FIGS. 3B. FIG. 3E illustrates an open-close circuit, being an open filter 54 followed by a close filter 55.
The result of opening a data sequence with a flat, or equal valued template, is that all peaks shorter than M-1 samples are eliminated. When closing the same sequence with the same template, all pits shorter than M-1 samples are eliminated. Therefore, an open is generally used to eliminate peaks, and a close is used to eliminate pits. These results are illustrated in FIGS. 4A and 4B. FIG. 4A shows the response of an open, i.e., an erode and then a dilate, with a template length, M of three samples, and m values of 1. After the erode operation, the peak has been suppressed from the output signal, but the pit has been lengthened. Following the dilate operation, the peak remains suppressed but the pit has been returned to its original position, such that the effect of the operation has been simply to suppress the peak which is less than the three samples. FIG. 4B shows the close operation, wherein the dilate operation first suppresses the pit but extends the peak, following which the erode operation returns the peak to its normal form, with the result being simply that the pit has been suppressed. Thus, in both open and close, the first step does the filtering of the either the pit or the peak, whereas the second step substantially recreates the original form of the input signal without the suppressed peak or pit.
When the open and close operations are combined, the two characteristics provide a filter that substantially suppresses both peaks and pits, while leaving the remainder of the signal unaffected. These filters are simply called open-close, e.g., first opening and then closing a signal, or close-open. An open-close is illustrated in FIG. 3E, where an open filter 54 is followed by a close filter 55. Since two dilations and two erosions are performed, the resulting output set has lost 2 (M-1) samples at the beginning and 2 (M-1) at the end, such that the output set is 4 (M-1) samples shorter than the previous set. The results for an open-close or close-open operation are shown in FIG. 4C, illustrating that both open-close and close-open achieve substantially identical results, eliminating the peak and pit. However, for a less ideal data set, bigger differences between the outputs of open-close and close-open may occur, especially for non-flat templates. It can happen where the first step stretches a peak or a pit beyond template length, thus making it impossible for the second to eliminate it. Thus, for a filter that is to primarily eliminate peaks, such as discussed below for use in rejecting FFR-waves from an AEGM, the use of an open-close is advisable, because the first step is better suited for this action.
For the preferred pacemaker embodiment of this invention, both size and energy consumption of the circuit must be minimized as much as possible, in order to preserve battery power. Consequently, the presently preferred embodiment embraces an analog form of morphological filters, with each dilate or erode unit requiring an analog delay line with M taps; an adder for every tap; a memory cell for each adder which is individually programmed; and a connection from each adder to the maximum or minimum circuit. In view of the fact that an extra memory cell per tap is needed, if the template values are variable, this suggests the desirability of using common template values, as otherwise the circuit complexity is at least linearly dependent on the template length; and further the circuit space and the required power consumption are increased with template variability. It has been found that, for processing the AEGM, the common template values (m) can be used without sacrifice of reliability. Of course, for more complex wave forms, variable templates may be required in order to achieve an optimum compromise of accurate filtering and cost. Also, to minimize the complexity of the calculations, and depending on the characteristics of the input signal, certain taps can be left out if the associated template values are small compared to adjacent values. When the rate of change of the input signal is limited that a small template value might be associated with the winner, i.e., either maximum or minimum, is small.
Referring now to the specific problem of capturing the P wave while rejecting the FFR-wave, it is important to recognize that the P wave is shorter in width, or duration than the FFR-wave. In order to filter out the FFR-wave with a morphological filter, it would be required to have a non-flat template with a length approximately the length of one AEGM period, i.e., one P-P interval. However, it is noted that the P wave itself can be suppressed with a template no larger than the length of the P wave, i.e., with a smaller template. Accordingly, the circuit of FIG. 5 is preferred, wherein the AEGM analog signal is inputted into morphological filter 58, which is set to suppress the P wave. The output, namely the input signal less the P wave peak which the pacemaker wants to see, is subtracted from the input signal, leaving only the P wave. The subtraction must involve signals that correspond in time, and since filter 58 introduces a delay, the input is passed through delay circuit 59 to introduce a like delay. The results of this operation, as well as the influence of the choice of M, is seen in FIGS. 6A, 6B and 6C. In FIG. 6A, a template length of three samples, with a clock frequency of 1 kHz, is utilized. As seen in the top curve, the input contains the larger amplitude P wave complex, as well as the FFR-wave. The output of the filter, with a portion of the positive going peak of the P wave subtracted, is different only in the area of the P wave. Consequently, as seen in the bottom curve, the input minus the output results in two peaks occurring around the P wave, one negative and one positive, both of these being three samples long. In FIG. 6B, a template of 7 samples length is utilized, resulting in a final output of just a positive peak which is 7 samples long. This appears to be an optimum result, because the positive P wave peak is clearly defined, and no FFR-wave is present. Note also that there is a clear zero baseline as a result of this operation. In FIG. 6C, a 15 sample long filter generates a larger peak around the P wave, but also yields a small response around the FFR-wave. While, in this specific case, the difference in amplitudes might be used to distinguish the two responses, this is clearly less desirable than the result of FIG. 6B. Additionally the longer template entails more expense and power consumption. Accordingly, the filter with M=7 is chosen as the best tradeoff between output amplitude and circuit complexity. As a general guide, the invention thus directs setting the template to a size compared to the wave portion of interest, so as to yield a clear peak output corresponding to the wave portion.
Referring now to FIG. 7, there is shown a block diagram of a dual chamber pacemaker wherein the clock frequency, F S is adjusted to track variations in the rate of the cardiac signals. As shown, the atrial signal, or AEGM, is inputted into sample block 60, which is sampled by clocks generated at a rate F S by clock circuit 64. At the same time, the ventricular signal derived from the ventricular lead, or VEGM, is sampled at circuit 66, also by clocks at a rate of F S . The AEGM samples are inputted into morphological filter 61, for deriving P wave signals; the VEGM samples are inputted into morphological filter 68 for deriving R-wave signals. The R-wave signals are also passed into peak detector 70, to provide R-wave pulses. The R-wave pulses in turn are inputted into circuit 72, which determines the RR rate, and provides an output control signal which corresponds to the RR rate. Thus, RR variations produce variations in QRS and P wave duration, and the pacemaker adapts by changing the sampling rate accordingly. The sampling rate control signal is connected from circuit 72 to clock circuit 64 in order to accomplish this automatic adjustment.
Referring now to FIG. 8, there is shown a block diagram of a pacemaker, or like device for processing different portions of a signal, or different signals. Thus, in a typical pacemaker application, there may be a first morphological filter for separating out the QRS portion and a second for the T-wave portion; or there may be one morphological filter for separating out the QRS portion of the ventricular signal and another for the P-wave portion of the atrial signal. In such situations, the same template may be used for each morphological filter, with corresponding respective differences in the sample frequency for optimizing the signals which are to be filtered out. As illustrated in FIG. 8, a common analog signal is connected to sample circuits 75 and 77, which provide samples to filters 76 and 78 respectively. Sample circuit 75 is clocked with clock frequency F S , whereas circuit 77 is clocked with clock signals at a frequency F S ÷N, where N may be any chosen number. In the illustrated embodiment, a common template is derived from memory 80, and inputted into both of the filters. Although not shown, memory 80 may be programmable by programming from an external source. In another embodiment, n different templates are used to control n different morphological filters, for identifying n respective wave types.
Referring now to FIG. 9, there is shown a flow diagram which illustrates the primary steps taken in filtering signals in accordance with this invention, and for adjusting the template characteristics for the morphological operation. FIG. 9 specifically illustrates the steps taken in a pacemaker for deriving a P-wave from which the FFR wave has been suppressed. At 84, the length M of the operation; the template (m) numbers; and the clock rate (F S ) are initialized, in accordance with programmed initial data. At 85, the pacemaker gets a continuous atrial analog signal from the atrial lead, and provides it to the morphological filter. At 86, a filter performs the morphological operations, deriving a signal from which the P-wave has been removed, as discussed above. At 88, the filtered signal is subtracted from the analog signal to get the resultant P-wave peak signal. At 89, a decision is made as to whether to adjust the template length, the template or the clock frequency. If yes, at 90 the pacemaker performs an error analysis on stored values of recent P-waves, and prescribes a corresponding adjustment. Such an error analysis may suitably include evaluating variations in the root mean square of recent P-waves as detected. The routine then loops back and continues to perform the morphological operations on the incoming atrial signal.
Although the important application of sensing P-waves and filtering out FFR-waves has been illustrated, the invention is equally applicable for other pacemaker functions. For example, in an AAI pacemaker, it can be extremely useful to sense, i.e., pick out FFR-waves, so as to enable detection of ventricular depolarizations without a lead in the ventricle. This can be done by adjusting the template to the morphology of the FFR-wave. Here, the template width must be comparable to the FFR-wave length. Thus, the operation is the same as presented in FIG. 9, except that at step 88, it is the FFR-wave that is obtained. Likewise, different tachycardias can be discriminated by having respective morphological filters adapted to the shape of the tachycardia, e.g., a supra-ventricular tachycardia (SVT) can be discriminated from ventricular tachycardia (VT), and SVT can be discriminated from sinus tachycardia. | A system and method are provided, particularly useful for an implantable cardiac pacemaker, for morphological filtering of sensed signals to reliably and accurately identify one or more specified wave portions of the sensed signals. In a first pacemaker embodiment, morphological filtering is done on the sensed atrial signal, whereby the P-wave peak is discriminated out, with the resulting signal minus the P-wave peak being then subtracted from the inputted atrial signal to provide the atrial peak, thereby effectively eliminating sensing of FFR-wave portions. By setting the morphological filter length to correspond to about the duration of the P-wave peak, or just slightly larger, and by adjusting sampling frequency to correspond to cardiac rate variations, there is provided optimized filtering consistent with low power consumption in an implantable device. In other embodiments, FFR-waves, T-waves, VT, SVT and sinus tachycardia are identified by using templates matched to the wave to be identified. The invention can be performed with either analog or digital embodiments, analog embodiments providing for lower power consumption. | 0 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 09/555,555, filed Sep. 25, 2000, which is a section 371 National Phase of PCT/GB98/03688, which are incorporated by reference as if fully set forth.
FIELD OF INVENTION
[0002] This invention relates to methods of identifying, targeting and of isolating a group of CD94+ cells, in particular a group of CD94+ cells including natural killer (NK) cells and a subset of T cells. The invention also relates to methods of targeting functional moieties such as toxins to the CD94+ cells. The invention further relates to multimeric complexes of HLA-E for use in the methods.
BACKGROUND
[0003] Human leukocyte antigen-E (HLA-E) is a nonclassical MHC class Ib molecule of very limited polymorphism. Human nonclassical MHC class Ib molecules (which include HLA-E, HLA-F and HLA-G) are homologous to classical MHC class Ia molecules (HLA-A, HLA-B and HLA-C) but are characterised by limited polymorphism and low cell surface expression (reviewed in Shawar et al 1994 Annu. Rev. Immunol. 12: 839). The mouse MHC class Ib molecule Qa-1 shares some characteristics with HLA-E in that it displays a broad tissue distribution and some structural similarities in the peptide-binding groove (reviewed in Soloski et al 1995 Immunol. Rev. 147: 67).
[0004] Whereas the function of the classical MHC class 1 molecules in presenting peptides derived from cytosolic proteins to CD8+ T cells is well-established, the function of nonclassical MHC molecules remains unknown, in particular for HLA-E. HLA-E is transcribed in most tissues. Recently, we have shown that HLA-E is able to bind in its peptide-binding site peptides derived from MHC class I leader sequences at positions 3 to 11 (Braud et al 1997 Eur. J. Immunol. 27: 1164-1169). The optimum binding peptide is a nonamer. Using alanine and glycine substitutions, it was established that there are primary anchor residues at positions 2 and 9 of the peptide and secondary anchor residues at position 7 and possibly position 3. The literature suggests that HLA-E is localised in the endoplasmic reticulum (ER) and might have a role in the loading of peptides onto classical MHC class I molecules in a similar way to HLA-DM for MHC class II molecules. Neither mouse cells transfected with HLA-E and human P2 microglobulin (β2m) nor the 721.221 cell line which only expresses HLA-E and HLA-F, show surface expression of HLA-E (Ulbrecht et al, J. Immunol. 1992 149: 2945-2953 and J. Exp. Med. 1992 176: 1083-1090).
[0005] Assembly of MHC class I molecules occurs in the endoplasmic reticulum (ER) and requires peptide translocation through the transporter associated with antigen processing (TAP) (reviewed in Cerundolo et all 1996 In HLA and MHC genes, molecules and function, Edited by Browning M, McMichael A. Oxford: Bios. Scientific Publisher Ltd; 193-223). In human cells, newly synthesized MHC class I heavy chains associate with calnexin which is later displaced by the association of β2m. Following dissociation of calnexin, class I-β2m heterodimers are stably associated with another ER resident protein, calreticulin. Another molecule, tapasin, which is associated with TAP and with MHC class I calreticulin complexes, acts as a bridge between them. MHC class I association with TAP facilitates peptide binding and the class I molecules are released and exported to the cell surface upon stable loading of peptide.
[0006] Natural killer (NK) cells are cytotoxic cells which have the morphology of large granular lymphocytes and are normally defined by their activity. They use recognition systems which are not yet clearly understood. Recognition of tumour cell lines and virally-infected cells is however driven by the absence of MHC class I at the target cell surface (some MHC class I molecules interact with specific NK receptors). NK cell cytotoxicity is mediated by the interaction between Fas and Fas ligand or by the release of the contents of the intracellular granules including the pore forming protein perforin and the serine protease granzyme B. NK cells are generally but not exclusively CD3- and CD56+. They may also be CD16+ and some are also CD8+. Certain CD8+ T cells have an NK cell-like function, in that they are able to kill MHC class I negative cells.
[0007] NK cells express receptors that interact with MHC class I and serve to inhibit or activate NK cell-mediated cytotoxicity. The killer cell immunoglobulin-like receptors (KIR), which are members of the immunoglobulin superfamily, make up one such group of receptors.
[0008] Another NK cell inhibitory receptor which has a similar effect is the CD94/NKG2A receptor from the C-type lectin superfamily, which is expressed at the cell surface as a heterodimer of CD94 covalently associated with NKG2A. CD94 also associates with other members of the NKG2 family, which consists of four closely related molecules NKG2A, B, C and E and two more distantly related molecules NKG2D and F. CD94/NKG2A and B are both inhibitory NK cell receptors which interact with MHC class I to inhibit NK cell lysis, while CD94/NKG2C is a stimulatory NK cell receptor which interacts with MHC class I to perform an NK cell triggering function.
[0009] The CD94/NKG2C activator receptor contains a third subunit DAP12, which is expressed as a disulphide-bonded homodimer and interacts with NKG2C via charged residues in the transmembrane domains (Lanier, 1998, Nature 391:703; Lanier et al, 1998, Immunity 8:693). DAP12 is necessary for efficient transport of the CD94/NKG2C complex to the cell surface. Ligation of CD94 on CD94/NKG2C/DAP12 transfectants causes tyrosine phosphorylation of DAP12, suggesting that it induces cellular activation via DAP12.
[0010] Four genes encode the NKG2 glycoproteins: NKG2A, NKG2C, NKG2E and NKG2D/F (Houchins et al, 1991, J. Exp. Med. 173:1017; Plougastel et al, 1997, Eur. J. Immunol. 27: 2835). NKG2A and B are alternative splicing products (differing by an 18 amino acid segment immediately outside the transmembrane region). NKG2C is highly homologous to NKG2A and B with 94% homology in the external C terminal domain and 56% homology through the internal and transmembrane regions. NKG2D is distantly but significantly related (21% homology) as too is NKG2F.
[0011] It has recently been discovered that HLA-E is stably expressed at a low level on the surface of cells. Its expression at the surface correlates with co-expression of human MHC class I molecules which possess a peptide in their leader sequence capable of binding to HLA-E. Loading of these signal sequence-derived peptides is TAP and Tapasin-dependent and HLA-E assembly appears to be similar to classical MHC class I assembly (Braud et al 1998 Current Biology 8:1-10).
[0012] It has now also been discovered that HLA-E binds to NK cells expressing receptors CD94/NKG2A, B and C. The majority of NK cells express CD94/NKG2 receptors and the majority of NK cells are capable of binding HLA-E. HLA-E also binds to a small subset of T cells expressing CD94/NKG2 heterodimers.
[0013] Furthermore, surface expression of HLA-E provides protection against killing by CD94/NKG2A+ NK cells.
[0014] In addition, it has been discovered that multimeric HLA-E molecules bind strongly to NK cells and the T cell subset expressing CD94/NKG2.
SUMMARY
[0015] In its broadest sense, the invention provides the use of the interaction between HLA-E and NK cells and/or a subset of T cells, to identify and/or target and/or isolate those cells; and HLA-E in a suitable form for such use.
[0016] The invention provides in one aspect a method of causing an interaction of CD94/NKG2+ cells, which method comprises contacting the cells with HLA-E under binding conditions.
[0017] The invention thus encompasses in one embodiment a method of identifying the presence of CD94/NKG2+ NK cells and T cells in a sample, which method comprises contacting the sample with HLA-E under suitable binding conditions and detecting binding of HLA-E to the cells.
[0018] In another embodiment, the method according to the invention provides a method of selecting for CD94/NKG2+ cells, in particular NK cells and a subset of T cells, from a sample, which method comprises contacting the sample with HLA-E under binding conditions and separating cells bound to the HLA-E from the mixture.
[0019] In still another embodiment there is provided a method of killing or inactivating NK cells and a subset of T cells, which method comprises contacting the cells with HLA-E under binding conditions and carrying out targeted killing on the bound cells. Any targeted killing method may be used, for example NK cells may be identified by detecting bound HLA-E, and then destroyed by use of a laser, or the HLA-E may carry a toxic moiety which kills or inactivates the cells to which the HLA-E binds.
[0020] In yet another embodiment, the invention provides a method of modifying NK cell activity against a potential target cell, by expressing HLA-E at the surface of the target cell. In this embodiment, the binding of the CD94/NKG2 receptors to the cell surface HLA-E thus causes an interaction between the CD94/NKG2+ cells and the HLA-E bearing cells. In the case of CD94/NKG2A or B receptors, this will be an inhibitory interaction the effect of which is to protect the HLA-E bearing cell from killing by the NK cells. In the case of CD94/NKG2C receptors there may be an NK cell stimulatory effect. In the case of NK cells expressing both inhibitory and activator CD94/NKG2 receptors, the overall effect of an interaction with HLA-E at the target cell surface is an inhibitory one, since the inhibitory receptors override the stimulatory receptors.
[0021] Thus, the invention involves the use of the newly discovered HLA-E—CD94/NKG2 receptor binding partnership for a variety of possible purposes. The interaction in the method according to the invention may be simply the binding of the CD94/NKG2 receptors to the HLA-E. Alternatively or additionally the interaction of the CD94/NKG2+ cells with the HLA-E may give rise to an effect on the activity of the CD94/NKG2+ cells, such as an inhibitory effect.
[0022] In further aspects, the invention provides CD94/NKG2+ cells isolated by the method according to the invention; and a population of cells depleted of CD94/NKG2+ cells by the method according to the invention.
[0023] In another aspect the invention provides a non-human mammalian cell which expresses HLA-E at the cell surface by virtue of a nucleic acid encoding HLA-E integrated into the genome of the cell. The nucleic acid encoding HLA-E is a heterologous nucleic acid in the sense that it is not found in those cells in nature. The invention also provides recombinant animals comprising such cells, which animals include transgenic animals which contain HLA-E-encoding nucleic acid material in their somatic and germ cells, as well as animals which are recipients of a transplant from such transgenic animals.
[0024] In another aspect the invention provides a method of testing a compound for biological activity, which method comprises:
(i) providing cells expressing CD94/NKG2 receptors at the cell surface; (ii) contacting the cells with HLA-E in the presence of the test compound; and (iii) determining whether the presence of the compound affects the binding of HLA-E to the cells;
and compounds identified by the method as being compounds which affect the binding of HLA-E to CD94/NKG2 receptors.
[0028] Preferably the cells expressing CD94/NKG2 receptors in the method according to this aspect of the invention do not naturally express the receptors, and most preferably they are non-human cells. The cells are preferably stable transfectants, that is to say they contain nucleic acid material expressing CD94/NKG2 stably integrated into their genome.
[0029] Compounds such as antibodies, in particular monoclonal antibodies, may be screened by the method for a particular desired property. Compounds may be identified by the method which interfere specifically with the interaction between HLA-E and CD94/NKG2A but not CD94/NKG2C, or vice versa. Antibodies with such specificity will be useful, for example to enable CD94/NKG2A NK cells to be distinguished from CD94/NKG2C cells. Therapeutic uses for antibodies which inhibit the binding of HLA-E to CD94/NKG2 receptors are also envisaged, for example in bone marrow transplantation. It can be difficult to find a matched human donor and allogeneic cells might not possess MHC class I ligands that can engage the inhibitory receptors of all NK cells. An antibody which specifically blocks the binding of NK cells to the activator receptor CD94/NKG2C will therefore be useful. Another example of a possible therapeutic use of the antibodies is in the treatment of certain autoimmune diseases.
[0030] In another aspect the invention provides a multimer of HLA-E comprising two or more HLA-E molecules, said multimer having enhanced binding capability compared to non-multimeric HLA-E, optionally labeled with a signal moiety. The multimers of HLA-E contain at least two subunits which have the binding properties of HLA-E receptors (that is they bind CD94/NKG2 receptors), linked together to produce a bi-functional or multifunctional species. Each subunit comprises all or a substantial part of the extracellular region of HLA-E, generally at least the α1, α2 and α3 HLA-E domains, together with β2 microglobulin, and a suitable peptide in the peptide binding groove. Preferred HLA-E multimers are tetramers, but other multimers for example dimers, trimers and multimers containing 5, 6, 7 etc. HLA-E molecules are not excluded.
[0031] In another aspect the invention provides a recombinant HLA-E coupled to a toxic agent. The purpose of the toxic agent is to kill or inactivate cells to which the recombinant HLA-E binds. It is sufficiently toxic for that purpose. The toxic agent preferably has a localised effect, that is it preferably does not affect surrounding cells to which the HLA-E is not bound. Preferably the recombinant HLA-E is in the form of a multimer.
[0032] In another aspect the invention provides a method of preventing HLA-E-mediated inhibition of NK cell activity. The method comprises selecting a compound that interferes with HLA-E-binding to an inhibitory CD94/NKG2 receptor and contacting an NK or T cell expressing an inhibitory CD94/NKG2 receptor with the compound.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0033] The invention is useful for diagnostic purposes and in general for monitoring diseases. Detection and/or quantization of NK cells or a subpopulation of NK cells, or a sub-population of T cells (which may be further identified by co-staining with anti-CD8 or anti-CD4 antibody or antibodies or ligands to other T cell markers) will be useful in a variety of conditions, including the following:
[0034] (i) Cancer, Lymphomas and Leukaemias (Particularly Large Granular Cell Leukaenias).
[0035] NK cells are believed to have an anti-tumour cell activity. A marker for progress of therapy, or simple prognosis, can be provided by monitoring NK cell numbers and optionally their state of activation. This will provide an extremely simple test. The methods described herein can be used to determine or estimate NK cell numbers in a sample taken from a patient. The numbers of NK cells and T cells with an NK-like activity (CD94/NKG2+) can be estimated by the use of antibodies against markers of NK cells (e.g, CD56 or CD16) or antibodies against T cell markers (e.g., CD3). The state of activation of the NK cells can be investigated by containing with antibodies to activation markers. Alternatively, the activation state of NK cells can be assessed in a functional assay in vitro. The NK cells are isolated from the sample and their cytolytic activity and/or ability to produce cytokines (e.g., interferon-γ and/or TNF-α) is assessed, either directly or after a short period in culture.
[0036] (ii) Infections
[0037] NK cell numbers may change during viral or other infections and knowing their numbers could be of great value for example in HIV infected patients. It will be of particular interest to monitor NK cell numbers in cytomegalovirus (CMV) infections. CMV has sequences in its proteins that are capable of affecting HLA-E expression. More specifically, these CMV sequences induce cell surface expression of HLA-E in the virus host cell.
[0038] (iii) Pregnancy
[0039] There is interest in the role of NK cells in the placenta, in the prevention of rejection of the foetus. The invention provides a means to monitor NK cells in the placenta.
[0040] (iv) Transplantation
[0041] NK cells may be involved in transplant rejection and graft-versus-host disease (GVHD) after bone marrow transplantation. Monitoring of NK cells may be of value in patient management.
[0042] (v) Immunodeficiency
[0043] The diagnostic use of HLA-E can be extended to the detection of new immunodeficiency syndromes, either inherited or acquired, which exhibit lower or higher than normal NK cell levels. Some treatments may be toxic or stimulatory to NK cells.
[0044] (vi) Autoimmune Diseases
[0045] It will be useful to monitor NK cells in autoimmune diseases such as systemic lupus erythematosus, diabetes, thyroid diseases, vitiligo, rheumatoid arthritis etc.
[0046] (vii) Following Treatment
[0047] The invention also enables the monitoring of secondary effects of any treatment which could lead to up or down regulation of CD94/NKG2+ NK cells.
[0048] Although NK cells are specifically referred to in the examples of diseases and conditions above, monitoring of the T cell subset expressing receptors recognised by HLA-E is also included.
[0049] The invention also has a range of therapeutic applications. Examples include the following:
[0050] (i) Enhancing NK Levels
[0051] The invention provides a method of selecting HLA-E binding NK cells or T cells from a mixed cell population. The selected cells can be expanded in vitro and returned to the patient. Such treatment may be effective in some serious infections or cancers where a growth deficiency of these cells is associated with poor prognosis.
[0052] (ii) Removing NK Cells
[0053] The invention provides methods and means for removal of HLA-E binding NK cells and T cells, for example from bone marrow to be used as donor bone marrow in transplantation. T cell depletion of bone marrow using other techniques is already known and is effective. HLA-E coupled to a toxin could also be used to destroy HLA-E binding cells in vivo.
[0054] (iii) Expressing HLA-E at the Surface of Cells
[0055] The invention provides a method and means for inhibiting or stimulating NK cell activity, by providing HLA-E at the surface of cells. NK cells play a role in transplant rejection. Therefore, by ensuring that HLA-E is expressed at the cell surface in a xenotransplant organ or tissue, the likelihood of rejection will be reduced and rejection may be avoided altogether.
[0056] Multimers of HLA-E in accordance with the invention can take a variety of possible forms. The HLA-E molecules may be associated with one another via a linker molecule. Alternatively or additionally the HLA-E molecules may be attached to larger entities such as membrane structures, for example liposomes. Suitable linker molecules include multivalent attachment molecules such as avid in, streptavidin and extravidin each of which has four binding sites for biotin. Thus, biotinylated HLA-E molecules can be formed into multimer complexes of HLA-E having up to four HLA-E binding sites. The number of HLA-E molecules in the resulting complex will depend upon the ratio of HLA-E molecules to linker molecules used to make the complexes, and also on the presence or absence of any other biotinylated molecules such as biotinylated signal moieties or toxic moieties. Preferred complexes are trimeric or tetrameric HLA-E complexes.
[0057] Other cross-linking techniques suitable for preparing HLA-E dimers or multimers include, for example, antibody cross-linking to produce dimers, and techniques using cross-linking agents such as fluorogenic compounds or other chemical cross-linking agents.
[0058] Described herein in detail is a method of making HLA-E tetramers by biotinylating recombinant HLA-E heavy chains (α1, α2 and α3 domains) and constructing complexes by refolding the HLA-E heavy chains in vitro with β2m molecules and with a synthetic leader peptide from HLA-B. In the method described, biotinylation sites are engineered into the C terminus of the HLA-E heavy chain and the recombinant HLA-E molecules are biotinylated by means of a suitable biotinylating enzyme. The multivalent linker molecule, in this case extravidin, is then added. Variations of this tetramerisation method are envisaged. For example, the β2m could be chemically biotinylated at its seven lysine residues, four of which are in an appropriate position to allow complexing.
[0059] Whatever form of HLA-E is used, a suitable peptide for binding in the HLA-E peptide groove will be required. Tables 1 and 2 show examples of possible peptides found at residues 3 to 11 of MHC class I leader sequences. The tables indicate which of these are found to bind to HLA-E in vitro. Other peptides which bind to HLA-E may be used, for example peptides from viral proteins which may be the same as or different to MHC class I leader sequence peptides. Although nonamer peptides are usually the optimum size for binding to HLA-E, it is possible that peptides which are slightly shorter or slightly longer, e.g., by one or two residues at one or both ends, will also work. A suitable assay for identifying synthetic peptides which bind to HLA-E is described in Braud et al 1997 Eur. J. Immunol. 27:1164-1169.
[0060] Labeling of the HLA-E may be carried out by any suitable method. Described herein is tetrameric HLA-E labeled with phycoerythrin via the extravidin used to form the tetrameric complex. A variety of other signal moieties may be employed at a variety of possible sites on the HLA-E monomer or multimer, and the HLA-E may be labeled before, during or after multimerisation. Useful signal moieties commonly employed for labeling proteins include radioactive (e.g., 32-P or 33-P or 35-S), fluorescent (e.g. FITC) and enzymatic (e.g. horseradish peroxidase) labels. These and other detectable labels may be employed in the invention.
[0061] HLA-E is also provided according to the invention linked to a support. The HLA-E thus immobilised is particularly useful for capture purposes, that is for capturing and separating CD94/NKG2+ cells. A mixture containing or suspected of containing CD94/NKG2+ cells is brought into contact with the immobilised HLA-E under binding conditions and unbound material is removed. CD94/NKG2+ cells may then be recovered. Examples of suitable solid supports include but are not limited to support bodies or particles which may be for example in the form of beads, wells, tubes and plates. The HLA-E may be immobilised by a variety of means well-known in the art and may be attached to the support by means of a suitable linker molecule.
[0062] HLA-E is also provided according to the invention attached to an effector agent such as a toxic moiety, the purpose of which may be the targeted depletion of CD94/NKG2+ cells in a mixed population of cells in vitro or in vivo. The toxic moiety is preferably a toxin which selectively kills the cells to which the HLA-E is bound. Suitable toxins can be derived from natural sources such as plants (for example ricin, abrin) or bacteria (for example diphtheria toxin, Pseudomonas exotoxin), or they may be synthetic or synthetic versions of naturally occurring toxins. In one particular example, the toxin is coupled to HLA-E by means of a linker molecule that introduces a disulphide bond between the HLA-E and the toxin (Vitetta et al, Biol. Therapy of Cancer, 1991, 482-495; Myers et al, J. Immunol. Methods, 1991, 131: 221-237). Thioether or other related compounds may be used to form non-reducible linkages. In another example, the toxin is expressed as a fusion protein with the HLA-E molecule, by splicing the gene encoding the toxin to the gene encoding the ligand to create a recombinant fusion protein (Pastan et al, Annu. Rev. Biochem., 1992, 61: 331-354). Such fusion proteins may also include a biotinylation site to enable the creation of tetrameric or multimeric complexes of the toxin and HLA-E.
[0063] In general, the HLA-E described herein for use in detecting and separating and targeting toxins to CD94/NKG2+ cells will be a soluble HLA-E molecule. The term “soluble” is used herein in the manner in which it is conventionally used in the art in relation to cell surface receptors. A soluble form of a cell surface receptor is usually derived from the native form by deletion of the transmembrane domain. The protein may be truncated by removing both the cytoplasmic and the transmembrane domains, or there may be deletion of just the transmembrane domain with part or all of the cytoplasmic domain being retained. The important thing is that the desired extracellular function of the receptor is retained, which in this case is the CD94/NKG2-binding capability of the HLA-E binding domain. Wild type HLA-E may be modified to achieve the desired form by proteolytic cleavage, or by expressing a genetically engineered truncated or partially deleted form.
[0064] HLA-E for use in the invention which is present at surface of a cell on the other hand is preferably, although not necessarily, a membrane-bound form of HLA-E containing a transmembrane domain. It may or not also have a cytoplasmic domain. In order to get HLA-E expressed at the surface of a cell which does not normally express HLA-E at its surface, it is necessary to provide a peptide which binds in the HLA-E peptide binding groove. The peptide may be derived either from an HLA leader sequence which is permissive for HLA-E expression, or it may be derived from another source which expresses peptides that bind to HLA-E and induce its expression. Such other sources include viruses which escape NK cell-mediated cytotoxicity by encoding a peptide which binds to HLA-E and induces its expression. For example, the human cytomegalovirus (HCMV) encodes a protein known as UL40 (Accession No. p16780) which possesses a peptide capable of binding to HLA-E (see fourth leader sequence peptide listed in Table 1).
[0065] Thus, HLA-E expression at the surface of a non-human mammalian cell may be achieved for example by co-transfecting the cell with nucleic acid encoding HLA-E and another HLA class I which has a leader sequence peptide capable of binding to HLA-E. Alternatively the cell may be co-transfected with nucleic acids encoding HLA-E and UL40 of HCMV. The inventors have shown that when transfected with UL40, cells expressing HLA-E intracellularly are induced to express HLA-E at the cell surface. Instead of co-transfecting the cells with two different sequences, the cells can be transfected with a single vector containing both sequences, or more conveniently, with a chimeric nucleic acid which encodes a fusion protein of HLA-E with the peptide. This chimeric nucleic acid may be for example a recombinant nucleic acid encoding HLA-E, in which the leader sequence of HLA-B8 replaces the leader sequence of HLA-E. In another example, the nucleic acid encodes HLA-E linked to the peptide via a linker of sufficient length to allow the peptide to locate in the peptide-binding groove while also remaining covalently attached to the HLA-E molecule. In this instance, the peptide is not a part of the leader sequence which is cleaved off, and is instead linked to the mature HLA-E molecule which is expressed at the cell surface. Advantageously, the peptide is linked to the HLA-E heavy chain via the HLA-E N-terminus (the α-1 domain). Such MHC-linked peptides are described in the published literature (see for example Mottez et al., J. Exp. Med., 1995, 181:493-502). It may also be advantageous to express the HLA-E heavy chain and 2m as a fusion protein. Such fusions are described in the literature (see for example Toshitani et al., PNAS, 1996, 93:236). Thus, the HLA-E-peptide molecule may be expressed from a single coding sequence.
[0066] For the provision of HLA-E at the cell surface in organs or tissues to be transplanted into another species, suitable transgenic animals can be produced. Techniques for generating transgenic animals such as transgenic pigs or rats or mice are well known in the art. For the purposes of the invention, nucleic acid material which expresses HLA-E and a suitable HLA-E binding peptide in the recipient organism is introduced into cells of the organism at the appropriate early stage of development. Individual animals which express HLA-E at the surface of their cells are then selected. Organs or tissues from those animals provide xenogeneic material for transplantation.
[0067] The absence of HLA-E in xenogeneic cells makes them susceptible to NK cell-mediated lysis because their MHC class I molecules fail to be recognised by human killer cell inhibitory receptors. This is evident from inducing expression of HLA-Cw0301 on porcine endothelial cells, which protects the porcine cells against xenogeneic cytotoxicity mediated by NK cells expressing the inhibitory NK receptors binding to HLA-Cw0301 (Seebach et al, J. Immunol., 1997, 159:3655). There is evidence that NK cells play a role in the cellular immune response against xenografts (reviewed in Kaufman et al, Ann. Rev. Immunol., 1995, 13:339 and Bach et al, Immunol. Today, 1996, 17:379). The endothelium is the first site of contact between a vascularized xenograft and the recipient immune system. It has been shown that human NK cells adhere to the vascular endothelium and infiltrate into the xenogeneic organs (Kirk et al, Transplantation, 1993, 56:785; Inverardi, Immunol. Rev., 1994 141:71) and that NK cells directly activate porcine endothelial cells (Goodman et al, Transplantation, 1996, 61:763). It has been observed that xenogeneic human anti-porcine cytotoxicity in vitro includes an important MHC unrestricted contribution from polyclonal NK populations (Inverardi, Immunol. Rev., 1994, 141:71; Kirk et al, Transplantation, 1993, 55:294; Seebach et al, Xenotransplantation, 1996, 3:188). It has also been shown that transgenic mice expressing a killer cell inhibitory receptor from the immunoglobulin superfamily, CD158, which recognises HLA-Cw3, are prevented from rejecting H-2 mismatch bone marrow grafts which express the cognate MHC class I HLA-Cw3 allele (Cambiaggi et al, PNAS, 1997, 94(15):8088-92. Thus, an HLA-E transgenic animal can be used to provide organs which will not be prone to attack by human NK cells expressing CD94/NKG2A receptors.
[0068] Xenogeneic transplantation will also involve the use of other mechanisms and/or reagents for the purpose of improving transplant survival. In particular, immunosuppressive agents may be employed. Immunosuppressive drugs are commonly used in transplantation therapy.
[0069] Currently, the primary animal species proposed as sources of xenografts are pigs and baboons (and possibly cows). Examples of particular treatments currently under consideration are:
treatment of Parkinson's disease by implantation of porcine foetal neuronal tissue; treatment of diabetes mellitus by implantation or infusion of encapsulated porcine pancreatic islet cells; treatment of hepatic failure by perfusion through or implantation of whole pigs livers;
(see Deacon, Nat. Med., 1997, 3:350; Tibell, Transplant. Proc., 1994, 26:762; Cramer, Transplant. Proc., 1995, 27:80).
[0073] It will be evident that in addition to any special features such as the absence of transmembrane and/or cytoplasmic domains, or the presence of biotinylation sites required for multimerisation, the recombinant HLA-E used in the invention may have other features which make it different to native HLA-E. For example, the recombinant HLA-E may have deletions or insertions or altered residues compared to native HLA-E, which result in improved properties such as enhanced binding capability or improved stability, for use in accordance with the invention. HLA-E having improved stability at elevated temperatures, such as temperatures over 4° C. and/or over room temperature and/or at or around 37° C., will be of particular interest.
[0074] HLA-E in recombinant form as described herein is also provided in formulations suitable for in vivo use. Such formulations comprise a pharmaceutically acceptable diluent or carrier.
[0075] HLA-E itself exhibits very little polymorphism. The sequences for two different alleles of HLA-E can be found in the following data base locations: E*0101 at M20022 (arg in the residue at position 107); E*01031 at M32507 (glycine residue at position 107).
[0076] Some further, known techniques the principles of which may be additionally applied in the separation, identification or targeted killing methods of the invention are discussed below.
[0077] Some known separation methods will be adaptable for use in the separation or isolation of CD94/NKG2+ cells using HLA-E. For example, T cell populations can be isolated by use of antibody-coated plates. The antibodies are specific for particular cell-surface markers. Cell separation can be a negative selection process or a positive selection process (Wysocki et al, 1978 PNAS 75:2840-2848). HLA-E coated plates may be used to separate CD94/NKG2+ cells.
[0078] Immunomagnetic purification of a T cell subpopulation can also be realised using suitable antibodies coated on magnetic beads, in a negative or a positive selection process (Funderud et al, 1987 in Lymphocytes: A Practical Approach Oxford University Press, New York 5561). HLA-E-coated beads may be similarly employed for selection of CD94/NKG2+ NK cells and T cells.
[0079] FACS (fluorescence activated cell sorting) techniques may also be employed. Cell sorting of fluorescence-labeled cells uses flow cytometry to monitor the expression of specific intracellular and cell surface molecules and sort cell populations (Fleisher et al, 1988 Cytometry 9:309-315).
[0080] Techniques which may be used in accordance with the invention for selective depletion or targeted killing of CD94/NKG2+ cells in a mixed cell population include antibody/complement-mediated cytotoxicity. Using a complement-fixing antibody, the cells expressing the marker recognised by the antibody can be lysed in presence of complement (Bianco et al, 1970 J. Exp. Med. 132:702-720). For example, an anti-HLA-E antibody may be employed to selectively destroy cells to which HLA-E is bound.
[0000]
TABLE 1
Examples of peptides generated from MHC class
I leader sequences at residues 3-11
Leader sequence peptide (3-11)
from MHC class I
Binding to HLA-E in vitro
-VMAPRTLVL
+
-VMAPRTLLL
+
-VMAPRTVLL
+
-VMAPRTLIL
+
-VMAPRTLFL
+
-VMGPRTLVL
+/−
-VTAPRTVLL
−
-VTAPRTLLL
−
-VMPPRTLLL
+
-VMEPRTLIL
−
-VMAPRALLL
−
[SEQ ID NOS: 1-11]
EXAMPLES
Example 1
Construction of HLA-E Tetrameric Complexes
[0081] HLA-E-tetrameric complexes were constructed by refolding recombinant HLA-E and β2m molecules in vitro with a synthetic peptide (VMAPRTVLL) [SEQ ID NO 3] derived from residues 3-11 of the signal sequence of HLA-B*0801. A biotinylation site was engineered in the C terminus of the HLA-E heavy chain, allowing HLA-E/β2 m/peptide complexes to be enzymatically biotinylated using E. coli BirA enzyme and conjugated with phycoerythrin (PE)-labeled Extravidin to create tetrameric complexes. HLA-A and -B tetramic complexes have proved to be very efficient at specifically binding to T cell receptors on antigen-specific CD8+ T cells from peripheral blood in vitro (Altman et al, 1996 Science 274: 94-96).
[0082] Methods
[0083] HLA-E was cloned by RT-PCR with primers C007 and C006 from RNA extracted from monocytes of an HLA-E*0101 homozygous individual. The N terminal nucleotide sequence was synonymously altered by PCR mutagenesis using the primers C017 and C006 to optimise protein expression from the pGMT7 vector in E. coli . The coding sequence for the extracellular portion of HLA-E (residues 1276) was amplified using the primers C017 and C023 and recloned into a pGMT7 derivative to produce the expression plasmid COC092 which contains the BirA recognition and biotinylation site in frame at the 3′ end of the HLA-E heavy chain.
[0000] Primers were:
[0000]
COO6
[SEQ ID NO: 12]
gtgggctaagcttacggcttccatctcagggtgacgggctc
COO7
[SEQ ID NO: 13]
ctacgggcatatggtagatggaaccctccttttactctcc
CO17
[SEQ ID NO: 14]
ccgtacctcgagcatatgggttctcattctttaaaatattttcatacttc
tgtatctagacccggccg
CO23
[SEQ ID NO: 15]
tggtgtctagaggatcctggcttccatctcagggtgacgggctcg
[0084] HLA-E tetrameric complexes were generated essentially as described (Altman et al 1996). Briefly, HLA-E and β2m proteins were over expressed in E. coli strains BL21 (DE3) pLysS and XA90 respectively, purified from inclusion bodies, solubilised into a urea solution, then refolded by dilution in vitro with a synthetic peptide (VMAPRTVLL) [SEQ ID NO 3] from HLA-B*0801 leader sequence (Research Genetics). HLA-E heavy chain/β2 m/peptide complexes were biotinylated with BirA enzyme, purified by FPLC and Mono-Q ion exchange chromatography, then complexed in a 4:1 molar ratio with Extravidin-PE (Sigma).
Example 2
Binding of HLA-E Tetramers
[0085] Peripheral blood mononuclear cells (PBMC) from 9 normal donors were stained with HLA-E tetramer prepared as described in Example 1 and compared to staining observed with an HLA-A2 tetramer refolded with Epstein Barr Virus (EBV) lytic cycle BMLF1 259-267 peptide epitope (Steven et al, 1997 J. Exp. Med. 185: 1605-17). A high frequency of lymphoid cells were stained with the HLA-E tetramer (range 2 to 11%) ( FIG. 1A ), whereas the HLA-A2 tetramer generally stained 0 to 0.8% of the lymphocytes in EBV-seropositive donors ( FIG. 1C ). By setting an electronic gate on the lymphocytes binding HLA-E tetramer, we observed that a large proportion were NK cells (typically 40 to 80% CD3 − , CD56 + ) but a significant subset were T cells (typically 15 to 50% CD3 + ), some of which were also expressing CD56 ( FIG. 1B ). About 2% of the lymphocytes binding HLA-E tetramer were CD4+ T cells, and about 5% were CD19+ B cells, but these could represent non-specific binding because of similar staining with the HLA-A2 tetramer (data not shown). The HLA-A2 tetramer did not bind to CD56+ cells but, in EBV-seropositive donors, bound to EBV specific CD3 + , CD8+ T cells ( FIG. 1D ), confirming previous studies on the specificity of MHC-tetrameric complexes for T cells bearing a specific T cell receptor (Altman et al 1996).
[0086] HLA-E tetramer staining was abolished when the PBMC and the tetramer were incubated in the presence of the antibody HP3D9 (Aramburu et al, 1990 Immunol. 144: 3238-47) against CD94, an NK cell receptor belonging to the C-type lectin superfamily (Chang et al, 1995 Eur J. Immunol. 25: 2433-37) ( FIG. 2A ). As the antibody HP3D9 was diluted, the HLA-E tetramer staining was restored (data not shown). The interaction between HLA-E and CD94 was also confirmed by staining a number of well-characterised CD94 + NK clones with HLA-E tetramer and demonstrating that another anti-CD94 nAb (DX22) (Phillips et al, 1996 Immunity 5:163-172) completely inhibited HLA-E tetramer binding ( FIG. 2B , and data not shown). No staining with HLA-A2 tetramer was found on CD94+NK clones (data not shown).
[0087] To characterise further the NK receptor interacting with HLA-E, we stained P815 and 293T cells transfected with these receptors. No HLA-E tetramer staining was observed on P815 stably transfected with CD94 alone or NKG2B alone ( FIG. 3A ), nor on 293T transiently transfected with CD94 or NKG2A alone (data not shown). In contrast, HLA-E tetramer bound to 293T cells cotransfected with CD94 and NKG2A, CD94 and NKG2B, or CD94 and NKG2C ( FIG. 3B ). Expression of the heterodimers on these transfectants was monitored using a polyclonal rabbit serum that reacts with CD94/NKG2A, NKG2B and NKG2C heterodimers (Lazetic et al, 1996 J. Immunol. 157: 4741-45). This result was confirmed using mouse pre-B Ba/F3 cells stably transfected with CD94/NKG2C or NK clones expressing the inhibitory receptor CD94/NKG2A ( FIG. 2B and data not shown). Carbohydrates on HLA-E are not necessary for binding, as the recombinant HLA-E used to make the tetramer was produced in E. coli . This is quite surprising given that both CD94 and NKG2 proteins are members of the C-type lectin superfamily. Carbohydrate residues may form additional points of interaction increasing the affinity of binding. We have also shown that HLA-E does not interact with other killer cell inhibitory cell receptors (KIR) as no staining with the HLA-E tetramer was observed on Ba/F3 cells transfected with KIR2DL1 (NKAT1 or p58), KIR2DL3 (NKAT2 or p58), KIR3DL1 (NKAT3 or p70), KIR3DL2 (NKAT4 or p70/140), KIR2DS2 (NKAT5 or p50), KIR2DL2 (NKAT6 or p58) or KIR2DS4 (NKAT8 or p50) (Lanier et al, 1997 Immunol. Rev. 155: 145154). Furthermore, staining of PBMC with HLA-E tetramer was not blocked by antibodies against any of these KIR receptors: EB6 (anti-KIR2DL1), GL183 (anti-KIR2DL3, -KIR2DS2, -KIR2DL2), DX9 (anti-KIR3DL1), or 5.133 (anti-KIR3DL1, -KIR3DL2) (data not shown). Thus, the CD94/NKG2 receptors appear to be unique and specific receptors for HLA-E recognition.
[0088] We have previously reported that HLA-E, like the mouse Qa-1 molecule (Aldrich et al, 1994 Cell 79: 649-658; DeCloux et al, 1997 J. Immunol. 158: 2183-2191; Cotterill et al, 1997 Eur. J. Immunol. 27: 21232132) can bind signal sequence-derived peptides from MHC class I molecules in vitro (Braud et al 1997) and recently showed that HLA-E cell surface expression is regulated by the binding of such peptides (Braud et al 1998). Most HLA-A and HLA-C alleles possess a leader peptide 3-11 that binds to HLA-E whereas only a third of HLA-B alleles do. The remaining B alleles have a Threonine at position 2 in the peptide instead of a Methionine. This substitution at a primary anchor residue disrupted peptide binding to HLA-E as measured in an in vitro peptide binding assay previously described (Braud et al 1997) (Table 2). Transfection of MHC class I alleles which have a leader peptide capable of binding to HLA-E into HLA-A, -B, -C, -G negative 721.221 cells resulted in expression of the endogenous HLA-E on the cell surface of 721.221 cells. When the leader sequence peptide was not capable of binding, no such upregulation of HLA-E at the cell surface was observed.
[0089] It has been shown previously that NK cells expressing an inhibitory CD94/NKG2A receptor do not kill 721.221 cells transfected with certain HLA-A, -B, -C, or -G alleles, but are able to lyse these transfectants in the presence of neutralising anti-CD94 or anti class I antibodies (Phillips et al, 1996 Immunity 5: 163-172; Sivori et al, 1996 Eur. J. Immunol. 26:2487-2492; Sivori et al, 1996 Transplant 28: 3199-3203). A striking correlation between the presence of an HLA class I leader sequence peptide capable of binding to HLA-E causing its surface expression and the specificity of the CD94/NKG2A inhibitory receptor is shown in Table 2. All the MHC class I alleles which, upon transfection, protect 721.221 cells from killing by CD94/NKG2A+ NK clones have a peptide capable of binding to HLA-E. Similarly, all HLA alleles incapable of protecting against these clones lack an HLA-E binding leader peptide. Together with the direct evidence for physical interaction between HLA-E and CD94/NKG2A, these results indicate that inhibition by the CD94/NKG2A receptor is mediated by recognition of HLA-E rather than a broad range of HLA-A, -B, and -C molecules. In further support of this, the HLA-A2 tetramer refolded around a Tax peptide epitope of human T-cell lymphotropic virus HTLV1 (Garboczi et al 1996 Nature 384:134-141) did not bind to CD94/NKG2A transfectants or NK cells expressing CD94/NKG2 receptors, despite the fact that HLA-A2 has been shown to have a protective effect against CD94/NKG2A+ NK clones and HLA-A2 target cell protection can be reversed in the presence of anti-CD94 or anti-class I antibodies. Furthermore we confirmed, by immunoprecipitation that the anti-class I antibody DX 17, which inhibits interactions between class I molecules and CD94/NKG2A, also recognizes HLA-E. It has recently been demonstrated that recognition of 721.221 target cells by CD94/NKG2A+ NK clones can be inhibited by transfection of HLA-G, another nonclassical class I molecule mainly expressed on trophoblast cells (Soderstrom et al, 1997 J. Immunol. 159: 1072-1075; Perez Villar et al, 1997 J. Immunol. 158: 5736-5743; Pende et al, 1997 Eur. J. Immunol. 27: 1875-1880). However, HLA-G also possesses a leader sequence peptide capable of binding to HLA-E and 721.221-G transfectants express a significant level of HLA-E. Similarly, Reyburn et al 1997 (Nature 386: 514-517) recently reported that human cytomegalovirus encodes a viral protein (UL18), with similarity to MHC class I, that can protect 721.221 cells from NK cell lysis, possibly involving CD94 receptors. Whether these observations can be explained by binding of HLA-G or UL18 leader peptides to the endogenous HLA-E molecules in 721.221 is under investigation.
[0090] HLA-E also binds to CD94/NKG2C which has been shown to activate cytolytic activity in NK cell transfectants (Houchins et al, 1997 J. Immunol. 158: 3603-3609) indicating that HLA-E is involved in regulating NK cell-mediated cytotoxicity via both CD94/NKG2A and CD94/NKG2B inhibitory NK cell receptors and CD94/NKG2C stimulatory NK cell receptors. Our present results demonstrate a novel role for a non-classical class I molecule HLA-E and identify its predominant receptor. It remains to be determined whether the strong preference of HLA-E for binding signal sequence-derived peptides is simply to permit expression of HLA-E or whether it is implicit in recognition by CD94/NKG2 receptors.
[0000]
TABLE 2
.221 cells
Inhibition of
Presence of leader
Concentration of
tranfected with
killing by
sequence peptide
peptide required to
HLA class I
CD94/NKG2A +
capable of binding
HLA leader sequence
obtain 50% of binding
alleles
NK clones*
to HLA-E§
peptide (residues 3-11)
to HLA-E†
.221
−
−‡
.221-A*0201
+
+
VMAPRTLVL
0.06
μM
.221-A*0211
+
+
VMAPRTLVL
0.06
μM
.221-A*2501
+
+
VMAPRTLVL
0.06
μM
.221-A*2403
+
+
VMAPRTLVL
0.06
μM
.221-A*3601
+
+
VMAPRTLLL
0.3
μM
.221-B*0702
+
+
VMAPRTVLL
0.06
μM
.221-Cw*0102
+
+
VMAPRTLIL
0.3
μM
.221-Cw*0401
+
+
VMAPRTLIL
0.3
μM
.221-Cw*0304
+
+
VMAPRTLIL
0.3
μM
.221-Cw*0801
+
+
VMAPRTLIL
0.3
μM
.221-G
+
+
VMAPRTLFL
0.3
μM
.221-B*1501
−
−
VTAPRTVLL
>100
μM
.221-B*5101
−
−
VTAPRTVLL
>100
μM
.221-B*5801
−
−
VTAPRTVLL
>100
μM
.221-B*4601
−
−
VTAPRTVLL
>100
μM
.221-B*5401
−
−
VTAPRTLLL
>100
μM
.221-B*5501
−
−
VTAPRTLLL
>100
μM
[SEQ ID NOS: 1, 1, 1, 1, 2, 3, 4, 4, 4, 4, 5, 7, 7, 7, 7, 8, 8, respectively]
*Results published by Phillips et al 1996
†A peptide binding assay was developed in vitro. Results are expressed as a ratio of optical densities referred to as percentage of binding to HLA-E (Braud et al 1997).
‡The HLA-A, -B, -C, and -G negative .221 cells express HLA-E and HLA-F which have a shorter leader sequence and lack the appropriate peptide capable of binding to HLA-E.
§The presence of a leader sequence peptide capable of binding to HLA-E upregulates HLA-E surface expression as measured on .221 and .221 cells transfected with HLA-A or -B alleles using the antibody DT9 recognizing HLA-E and HLA-C alleles
[0091] Figure Legends for Example 2
[0092] FIG. 1 HLA-E tetramer binds NK cells and a subset of T cells
[0093] Flow cytometry analysis on gated peripheral blood lymphocytes from normal EBV seropositive donor VB using (A) HLA-E tetramer refolded around the leader sequence peptide residues 3-11 from HLA-B*0801 or (C) HLA-A2 tetramer refolded around the Epstein Barr Virus (EBV) lytic cycle BMLF1 259-267 peptide epitope (Steven et al 1997). The phenotypes of (B) HLA-E tetramer or (D) HLA-A2 tetramer binding lymphocytes were further investigated in triple colour stains as indicated. Percentages in each quadrant are represented by the cross in the upper right. Within the total CD3-, CD56+ NK cell population, 10.3% of cells bound HLA-E tetramer, and within the total CD3+ T cell population, 2.2% of cells bound HLA-E tetramer. In contrast, less than 0.2% of CD3-, CD56+ cells bound HLA-A2 tetramer, whereas 1% of CD3+ T cells bound HLA-A2 tetramer.
[0094] FIG. 2 HLA-E tetramer staining is inhibited by anti-CD94 antibodies
[0095] (A) Peripheral blood lymphocytes from normal donor SRJ were stained with the anti-CD94 antibody HP3D9 (Aramburu et al 1990) (1/50 dilution of ascites) followed by FITC-anti-mouse IgG (Fab′) 2 (Sigma); HLA-E tetramer PE alone; or HLA-E tetramer-PE in the presence of HP3D9 (1/50) which inhibited HLA-E tetramer staining.
[0096] (B) The NK cell line NKL (Robertson et al, 1996 Exp. Haematol. 24: 406-415) expressing the NK receptor CD94/NKG2A but none of the KIR molecules was stained with the anti-CD94 antibody DX22 (Phillips et al 1996) (1 mg) followed by PE-anti-mouse IgG; HLA-E tetramer-PE; or HLA-E tetramer-PE in the presence of 1 mg of DX22 antibody which inhibited HLA-E tetramer staining. Percentages in each quadrant are listed in the upper right. The HLA-A2 tetramer refolded around the HTLV1 Tax peptide (Garbocz et al 1996) did not bind to NKL (data not shown).
[0097] FIG. 3 HLA-E binds to NK cell CD94/NKG2A, CD94/NKG2B and CD94/NKG2C receptors but not to CD94 or NKG2 alone.
[0098] (A) P815 cells were stably transfected with pBJ-neo vector containing human CD94 cDNA (Chang et al 1995) or NKG2B cDNA (Houchins et al 1991 J. Exp. Med. 173: 1017-20). Cells were stained with PE-control mouse IgG1 (cMIgG1) or IgG2b (cMIgG2b), anti-CD94 antibody DX22-PE, anti-NKG2A and B antibody DX20-PE, or HLA-E tetramer-PE. Neither P815 transfectant stained with HLA-E tetramer or HLA-A2 HTLV1 Tax peptide tetramer.
[0099] (B) 293T cells stably transfected with CD94 were transiently transfected with NKG2A, NKG2B, and NKG2C (Lazetic et al 1996). Flow cytometry staining was performed using rabbit preimmune serum (cRIgG) 1/500 final dilution or rabbit anti-CD94/NKG2 heterodimer serum (anti-CD94/NKG2) 1/500 final dilution, both followed by FITC-antirabbit IgG, or with HLA-E tetramer-PE. No staining with HLA-A2-HTLV1 tax peptide tetramer was observed. Staining of 293T-CD94 cells cotransfected with a control plasmid were not stained by HLA-E tetramer or the rabbit anti-CD94/NKG2 serum (data not shown).
Example 3
Transfection of Cells with HLA-E-Binding Leader Sequences to Enable HLA-E Expression and Protection Against NK Cell Clones
[0100] Methods
[0101] Human NK-cell clones were established and cultured as described (Litwin et al, 1993 J. Exp. Med. 178: 1321-1336). Cytotoxicity assays were performed as described (Phillips et al, 1996 Immunity 5: 163172). A chimeric cDNA containing the leader segment of HLA-G and the extracellular, transmembrane, and cytoplasmic domains of HLA-B*5801 was generated by PCR using the following
[0000]
oligonucleotide primers:
sense primer 1,
[SEQ ID NO: 16]
5′-GCGTCTAGAATGGTGGTCATGGCACCCCGA-3′;
antisense primer 1,
[SEQ ID NO: 17]
5′-CATGGAGTGGGAGCCGGCCCAGGTCTCGGT-3′;
sense primer 2,
[SEQ ID NO: 18]
5′-GGCTCCCACTCCATGAGGTAT-3′;
and
antisense primer 2,
[SEQ ID NO: 19]
5′-AAGCTTTCAAGCTGTGAGAGACA-3′.
[0102] PCR was performed using a wild-type HLA-G cDNA as a template with primer set 1 and using wild-type HLA-B*5801 cDNA as a template with primer set 2. Products from these PCR reactions were mixed and used as templates for a subsequent reaction with sense primer 1 and antisense primer 2. The product was digested with XbaI and HindIII and ligated into the pBJneo vector.
[0103] A chimeric cDNA containing the leader segment of HLA-B*0702 and the extracellular, transmembrane and cytoplasmic domains of mouse CD80 (or B7-1) was generated by PCR using the following oligonucleotide primers:
[0000]
sense primer 3,
[SEQ ID NO: 20]
5′-ACCGAGACCTGGGCCGTTGATGAACAACTG-3′;
antisense primer 3,
[SEQ ID NO: 21]
5′-GCAAGCTTCTAAAGGAAGACGGTCTGTTC-3′;
sense primer 4,
[SEQ ID NO: 22]
5′-GGGCGTCGACCCGGACTCAGAATCTCCTCAGACGCCGAG-3′;
and
antisense primer 4,
[SEQ ID NO: 23]
5′-CAGTTGTTCATCAACGGCCCAGGTCTCGGT-3′.
[0104] PCR was performed using a wild-type mouse CD80 cDNA as a template with primer set 3 and using wild-type HLA-B*0702 cDNA as a template with primer set 4. Products from these PCR reactions were mixed and used as templates for a subsequent reaction with sense primer 4 and antisense primer 3. The product was digested with SalI and HindIII and ligated into the pBJneo vector. PCR products were verified by sequencing. 721.221 B-lymphoblastoid cells were transfected with the wild-type and chimeric cDNAs and selected as described (Litwin et al 1993).
[0105] Results
[0106] To determine whether the presence of an HLA-E binding leader peptide that induces surface expression of HLA-E is enough to provide protection against CD94/NKG2A+ NK-cell clones, a chimeric complementary DNA (GLS-B*5801) was generated. It contained the leader segment of HLA-G (from which a peptide can bind to HLA-E; Table 2) and the extracellular, transmembrane and cytoplasmic domains of HLA B*5801 (an HLA molecule that is not implicated in recognition by CD94/NKG2A receptors—Phillips et al, 1996 Immunity 5:163-172). Stable 721.221 cell line transfectants were selected and analysed for susceptibility to lysis by NK-cell clones expressing CD94/NKG2A receptors. As shown in FIG. 4 a , an NK-cell clone expressing a CD94/NKG2A receptor efficiently killed untransfected 721.221 cells as well as 721.221 cells transfected with wild-type HLA-B*5801. However, protection against NK-cell-mediated lysis was conferred by expression of the chimeric GLS-B*5801 molecule but reversed in the presence of antibodies against either CD94 or HLA class I molecules. A chimeric cDNA (B7LS-mCD80) containing the leader segment of HLA-B*0702 (with a peptide that can bind to HLA-E; Table 2) and the extracellular, transmembrane and cytoplasmic domains of mouse CD80 was transfected into 721.221 cells and tested for lysis by CD94/NKG2A+ NK-cell clones. CD80 is an adhesion cell surface molecule expressed on activated B and T cells and macrophages. In this experiment CD80 is used as an irrelevant control molecule to show that only the leader sequence of MHC class I molecules is necessary to upregulate HLA-E and induce a protective effect. There was less lysis of 721.221 cells expressing the B7LS-mCD80 molecule but not of cells expressing wild-type CD80, and protection was reversed by anti-CD94 but not control antibodies ( FIG. 4 b ). These results indicate that an HLA-E binding leader peptide alone is enough to protect 721.221 cells from lysis by NK-cell clones expressing inhibitory CD94/NKG2A-type receptors.
[0107] These results provide further confirmation of HLA-E as a ligand for CD94/NKG2A.
[0108] Figure Legends for Example 3
[0109] FIG. 4 HLA-E mediates inhibition of NK cells through interaction with CD94/N KG2A.
[0110] (A) Lysis of 721.221 cells expressing HLA-B*5801, HLA-G or a chimeric molecule (GLS-B*5801) containing the HLA-G leader sequence and the extracellular, transmembrane, and cytoplasmic domains of HLA-B*5801 by a representative NK-cell clone expressing the CD94/NKG2A receptor. Assays were performed at an effector to target ratio of 0.5:1, in the presence of control immunoglobulin (clg), anti-CD94 (DX22), or anti-HLA class I (DX17) at 5 μg ml −1 .
[0111] (B) Lysis of 721.221 cells expressing mouse CD80 or a chimeric molecule (B7LS-mCD80) containing the HLA-B*0702 leader sequence and the extracellular, transmembrane, and cytoplasmic domains of mouse CD80 by two representative NK-cell clones expressing the CD94/NKG2A receptor. Assays were performed at an effector-to-target ratio of 1:1 in the presence of control immunoglobulin (clg) or anti-CD94 (DX22) at 10 μg ml-1.
Example 4
Isolation of CD94/NKG2+ Cells by Fluorescence Activated Cell Sorting
[0112] Peripheral blood mononuclear cells (PBMC) were obtained from venous blood which had been taken from donors into tubes containing Heparin. Briefly, blood samples were diluted 1:1 with serum free RPMI-1640 and 10 ml of diluted blood was laid onto a 5 ml Ficoll-Hypaque gradient. After a centrifugation at 1200 rpm for 30 minutes, the PBMC at the interface were carefully removed and washed twice in RPM I. The first centrifugation was performed for 10 minutes at 2000 rpm and the second for 10 minutes at 1200 rpm to remove most platelets. PBMC were then diluted in RPM and kept in sterile medium while processed.
[0113] Binding of HLA-E tetramer was monitored by flow cytometry and cells were sorted. PBMC (5×106) were incubated for 15 minutes at 37° C. followed by 15 minutes at 4° C. with 12 μl of HLA-E tetramer labeled with phycoerythrin (PE). CD3 monoclonal antibody labeled with FITC was then added for another 15 minutes at 4° C. Cells were then washed twice and sorted on a FACScan, which measures fluorescent light emission and separates distinct cell populations by electrostatic-deflection (electronic cell sorting). Single cells or subsets of cells stained by HLA-E tetramer were collected in sterile 96 well plates and put in culture. NK cells (CD3−, HLA-E tet+) and T cells (CD3+, HLA-E tet+) were grown in Yssel's medium (Yssel et al, 1984, J. Immunol. Methods, 72:2199) in the presence of irradiated feeder cells (PBMC and JY BCL), 0.1 μg/ml of PHA, and 100 U/ml or 10 U/ml of IL-2 respectively. Autologous cells processed in this way are suitable for reinjection into patients. FACS techniques can also be used to count cells for quantization purposes.
[0114] Suitable methods for culturing NK cells and clones are described in Litwin et al, J. Exp. Med, 1993, 178:1321-1336. Methods for maintaining T cells are described in Dunbar et al, Current Biol., 1998, 8(7) 413 and Nixon et al, Nature, 1988. 336: 484-487.
Example 5
Isolation of CD94/NKG2+ Cells using HLA-E-Coated Beads
[0115] Cells expressing CD94/NKG2 receptors were isolated with HLA-E-streptavidin coated dynabeads. Dynabeads M-280 Streptavidin are magnetic beads coated with streptavidin. Soluble HLA-E was engineered with a biotinylation site for BirA enzyme at the C terminus of HLA-E heavy chain and refolded with P2 microglobulin and a synthetic peptide derived from residues 3-11 of the signal sequence of some HLA molecules (described in Braud et al, 1998, Nature, 391:795). These HLA-E monomers were biotinylated using BirA enzyme and conjugated to Dynabeads M-280 using a standard protocol. Biotinylated HLA-E were incubated with PBS-washed Dynabeads M280 for 30 minutes at 4° C. with bidirectional mixing (2 μg HLA-E/10 7 Dynabeads). The beads were collected by placing the tube in a Dynal Magnetic Particle Concentrator (MPC) and the supernatant was removed. The beads were washed 5 times in the same way. HLA-E coated M-280 dynabeads were then mixed with isolated PBMC (obtained as described in Example 3) (107 beads/ml) and incubated for 20 minutes at 4° C. with gentle rotation. The tube was placed in a Dynal MPC and left to rest for 2 minutes. The supernatant was removed and the cells attached to the beads washed 5 times. Cells were then grown as described in Example 3.
[0116] NB: To deplete PBMC of cells expressing receptors for HLA-E, the supernatant is kept and the beads discarded.
Example 6
Targeted Killing of NK Cells
[0117] Recombinant biotinylated HLA-E is prepared as described in Example 1. A mixture containing biotinylated HLA-E and a biotinylated toxic agent such as the enzyme perforin in a molecular ratio of 3:1 is combined with extravidin to produce multimeric HLA-E linked to the toxic agent. A PBMC sample from a human donor is prepared according to standard techniques and contacted with the HLA-E reagent, resulting in killing of the CD94/NKG2+ cells present in the sample. CD94/NKG2 negative cells are recovered.
Example 7
Xenotransplantation
[0118] A recombinant DNA expressing HLA-E in which the leader sequence of HLA-E was replaced by the leader sequence of HLA-B8 was generated. This chimeric cDNA contains the leader sequence of HLA-B, and the extracellular (α1, α2 and α3), the transmembrane and the cytoplasmic domains of HLA-E. It was generated using the following oligonucleotide primers:
[0000]
sense primer A:
[SEQ ID NO: 24]
5′-CTCGGCGGCCCTGGCCCTGACCGAGACCTGGGCGGGCTCCCACTCCT
TG-3′
antisense primer B:
[SEQ ID NO: 25]
5′-TTCTGTCTAGATTACAAGCTGTGAGACTCAGACCCCTG-3′
sense primer C:
[SEQ ID NO: 26]
5′-CTGACCGAATTCGCCGCCACCATGCTGGTCATGGCGCCCCGAACCGT
CCTCCTGCTGCTCTCGGCGGCCCTGGCC-3′
[0119] The PCR was performed using the cDNA of HLA-E as a template with primers A and B. The product from that PCR was then used as a template for a subsequent reaction with primers B and C. The last product was digested with EcoR1 and Xbal and ligated into the expression vector pcDNA3.
[0120] Transgenic animals are then produced as follows. Females are superovulated, mated to fertile males and sacrificed the following day. Zygotes with two pronuclei are recovered and one of the pronuclei is microinjected with the DNA expressing the HLA-E-HLA-B leader sequence construct. Surviving embryos are reimplanted into pseudopregnant foster females and DNA samples from new borns are evaluated for the presence of the foreign gene (HLA-E construct). These techniques are described in detail in the literature (e.g., Guide to techniques in mouse development, P. Wassarman and M DePamphilis, Methods in Enzymology (Academic Press), Section X: Transgenic animals: pronuclear injection (p747-802) and Section X1: Transgenic animals: embryonic stem cells and gene targeting (p803-932)).
Example 8
Stable Transfection of CD94 and NKG2 Genes into Mammalian Cells
[0121] Mouse cells (P815, L cells) were sequentially transfected by electroporation or calcium phosphate DNA precipitation respectively, with a mammalian expression vector pcDNA3 (neomycin resistance gene) containing CD94 cDNA and either NKG2A or NKG2C with DAP12.
[0122] NKG2A and NKG2C cDNA was cloned into the expression vector pcDNA3.1/hygro vector (containing the hygromycin resistance gene) and DAP12 was cloned into the expression vector pcDNA3.1/zeo (zeomycin resistance). P815 cells were electroporated with 500 μF, 0.25 volt, and selection (G418 and hygromycin and zeomycin) was added 2 days later. Cells expressing a high level of receptors were sorted by flow cytometry. L cells were transfected by calcium phosphate DNA precipitation and selected in the presence of G418, hygromycin and zeomycin. Transfectants were cloned by limiting dilution and cell surface expression of the CD94/NKG2 receptors was monitored using specific antibodies.
[0123] The stable transfectants are useful for the identification of antibodies or other agents that interfere with HLA-E binding to CD94/NKG2. Agents which specifically interfere with HLA-E binding to either inhibitory CD94/NKG2 receptors (e.g., CD94/NKG2A) or stimulatory CD94/NKG2 receptors (e.g., CD94/NKG2C) can be identified by performing binding assays using two different transfectants. A list of known antibodies which interfere with HLA-E binding to CD94/NKG2 is given below:
[0124] Antibodies which block the interaction between HLA-E and CD94/NKG2 receptors:
[0000]
1
Anti-HLA-E:
3D12 (Lee et al, 1998, J. Immunol. 160: 4951
2
Anti-CD94:
HP3D9 (Perez-Villar et al, 1995, J. Immunol.
154: 5779) commercialised by Pharmingen
HP-3B1 (Aramburu et al, 1990, J. Immunol.
144: 3238) commercialised by Immunotech
X1A85 (Sivori et al, 1996, Eur. J. Immunol.
26: 2487)
DX22 (Phillips et al, 1996, Immunity,
5: 163) DNAX
3
Anti-NKG2A:
Z199 (Carreto et al, 1997, Eur. J. Immunol.
27: 563) commercialised by Immunotech
Z270 (Sivori et al, 1996, Eur. J. Immunol.
26: 2487)
[0125] The techniques described in this example may also be used to transfect mammalian cells such as murine L cells with nucleic acids encoding HLA-E as described herein. | The invention relates to a method of testing a compound for biological activity, which method comprises providing cells expressing one of the CD94/NKG2 family of receptors, contacting the cells with recombinant HLA-E under binding conditions in the presence of the test compound, and determining whether the presence of the compound affects the binding of HLA-E to the cells. The HLA-E property of binding to CD94/NKG2 receptors on NK cells and a subset of CD8+ T cells is useful for targeting CD94/NKG2+ cells for a variety of purposes such as identification, isolation, killing or inactivation. | 6 |
The present invention relates generally to chuck jaws for use with a rotatable power tool, such as a drill, for securely retaining a rotatable accessory therein. More particularly, the present invention relates to an insulating chuck jaw that electrically insulates a rotatable accessory (such as a drill bit) from the chuck assembly, and therefore prevents electric current from being conveyed from the rotatable accessory to the user.
BACKGROUND OF THE INVENTION
Rotatable power tools, such as electric drills, are often used in situations where the rotatable accessory may come into contact with a source of electricity. For example, the drill bit of a power drill may sever a wire located within a wall, or the drill may even cut into its own cord. Accordingly, for the safety of the tool operator, it is important to prevent the electric current from reaching the operator.
One known method of preventing electric current from reaching the operator includes the use of an insulating housing with insulated hand grip areas. Another known method, which is described in U.S. Pat. No. 3,685,843 to Anthony Jacyno, involves the use of an insulating member that is positioned within a metal drill chuck, for preventing flow of electric current between the drill chuck and the rotating spindle. A similar type of insulating sleeve is also described in U.S. Pat. No. 3,797,960 to Donald J. McCarthy.
One problem with these known insulating methods is that there is still a danger of electric shock if the operator's hand or other body part contacts the chuck assembly while the rotatable accessory is in contact with the electrical wire. While these prior art insulating methods do insulate between the drill bit and the handle of the device, they usually fail to insulate between the drill bit and the chuck assembly (which holds the drill bit in position). Thus, the electric current is free to flow from the drill bit, to the chuck assembly, and then to the operator if, for example, the operator's hand makes contact with the chuck assembly, which is normally made of metal.
Accordingly, it is an object of the present invention to provide an improved rotatable power tool which provides insulated components therein for preventing electric current from being transferred from the rotatable accessory to the operator.
Another object of the present invention is to provide an improved chuck assembly which is insulated in such a manner that prevents electric current from being transferred from a rotatable accessory to the outer surface of the chuck assembly.
An additional object of the present invention is to provide an improved insulated chuck assembly that is inexpensive and can be utilized with existing chuck assembly configurations.
Yet another object of the present invention is to provide an insulating chuck jaw that can be used, in combination with other similar chuck jaws, in a chuck jaw assembly for providing superior electrical insulation therein.
These and other objects of the present invention will be apparent from the following detailed description of the invention, while referring to the attached drawings in which:
FIG. 1 is a side view of a rotatable power tool including therein several of the present insulating chuck jaws;
FIG. 2 is a partial cross-sectional view of a chuck jaw assembly including therein several of the present insulated chuck jaws;
FIG. 3 is a perspective view of a first embodiment of the present insulating chuck jaw;
FIG. 4 is a front view of the longitudinal end of the first embodiment of the present insulating chuck jaw;
FIG. 5 is a side view of the first embodiment of the present insulating chuck jaw;
FIG. 6 is a cross sectional view of FIG. 5 taken along line VI—VI;
FIG. 7 is a perspective view of a second embodiment of the present insulating chuck jaw;
FIG. 8 is a front view of the longitudinal end of the second embodiment of the present insulating chuck jaw;
FIG. 9 is a side view of the second embodiment of the present insulating chuck jaw;
FIG. 10 is a cross-sectional view of FIG. 9 taken along line X—X;
The above-listed objects are met or exceeded by the present invention, which provides an improved chuck jaw in a chuck assembly of a rotatable power tool that prevents electrical current from being transferred between a rotatable accessory and the operator, even if the operator makes contact with the outer surface of the chuck assembly. One of the main features of the present invention is an insulating chuck jaw that it intended to be used in combination with other similar insulating chuck jaws. Generally, the present invention consists of an insulating chuck jaw with a chuck jaw tip that is preferably made of metal and is configured to make secure contract with a rotatable accessory, such as a drill bit. The chuck jaw tip is at least partially surrounded by an insulating material such that electric current cannot be passed from the chuck jaw tip to the remainder of the chuck assembly.
More specifically, the present invention provides a chuck jaw that is configured and arranged to be used in combination with other chuck jaws for securely retaining a rotatable accessory in position in a chuck assembly, where the chuck jaw includes a chuck jaw body that defines a generally longitudinal axis along the primary extension direction thereof and a chuck jaw tip that is positioned within the chuck jaw body and extends along at least a portion of the generally longitudinal axis of the chuck jaw body. The chuck jaw further includes an insulating material for preventing electrical current from passing between the rotatable accessory and the remainder of the chuck assembly via the chuck jaw.
In a first preferred embodiment, the insulating material consists of a generally channel-shaped component that is situated between the chuck jaw tip and the chuck jaw body. In a second preferred embodiment the insulating material forms the majority of the chuck jaw body, and the chuck jaw tip is embedded, at least partially, therein.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings, the first preferred embodiment of the present invention is shown in FIGS. 1-6, with FIG. 1 showing a power drill 10 . Power drill 10 is one example of the type of rotatable power tool that may employ the present insulated chuck jaw. Briefly, the power drill 10 includes a housing 12 , which is preferably made of plastic, that includes a handle portion 14 and an on/off trigger 16 . Located within the housing 12 is a motor (not shown), which is connected to a rotatable shaft 18 . The rotatable shaft 18 is further rotatably connected to a chuck assembly 20 , which is still further rotatably connected to a drill bit 24 . The drill bit 24 is secured in place within the chuck assembly 20 for rotation therewith via a plurality of chuck jaws 22 .
To operate the drill 10 , the user grips the handle 14 and presses the on/off trigger 16 to start rotation of the motor located within the housing 12 . The motor rotates the rotatable shaft 18 , the chuck assembly 22 , and the drill bit 24 because all of these components are rotatably connected together.
Referring now to FIG. 2, a partially cut-away view of the chuck assembly 20 is shown. The rotatable shaft 18 is externally threaded so that it can be secured to internally threaded body part 26 for rotation therewith. The threaded body part 26 includes therein a central bore 27 for receiving the drill bit 24 . The threaded body part 26 also includes a plurality of equally spaced bores 28 , which are inclined toward the central bore 27 . Preferably, the body part 26 includes three bores 28 . One chuck jaw 22 is seated within each of the bores 28 . An internally threaded nut 30 is configured to surround the chuck jaws 22 . Each of the chuck jaws 22 includes a threaded portion 32 that extends along at least a portion of its outer periphery. The nut 30 is preferably formed in half to facilitate assembly around the chuck jaws 22 , and a sleeve 34 is preferably used to retain the two halves of the nut in position.
The sleeve 34 and the nut 30 are configured to be rotatable together, such as via an interference fit or by having the nut 30 keyed into the sleeve 34 . The threads of the nut 30 are configured to mate with the threads 32 of the chuck jaws 22 . A chuck body 36 in the form of a tapered sleeve is positioned adjacent to the nut 30 and surrounds the chuck jaws 22 .
As known to those skilled in the art, the chuck jaws 22 may be extended (for gripping the drill bit 24 ) or retracted (for releasing the drill bit) through the use of a ratcheted key (not shown) that can be inserted into a key port 38 that is recessed within the chuck body 36 . More specifically, the key is rotated within the key port 38 such that the teeth located on the key contact the key ratchets 40 on the sleeve 34 . When the key is rotated, the sleeve 34 rotates, which in turn causes the nut 30 to rotate, resulting in the extension or retraction of the chuck jaws 22 due to the threaded connection between the nut 30 and the threads 32 of the chuck jaws.
One important aspect of the present invention is the configuration of the chuck jaws 22 . Referring now to FIGS. 3-6, the configuration of a first embodiment of the chuck jaws 22 will now be described. As shown in FIG. 3, the chuck jaw 22 of this embodiment includes a chuck body jaw 42 and a chuck jaw tip 44 . The chuck jaw body 42 includes a cutaway portion 48 which is peaked such that a generally V-shaped cross-section is formed, as can be seen in FIGS. 3, 4 , and 6 .
This embodiment also preferably includes a generally channel-shaped member 46 made of an insulating material such as plastic. Preferably, the chuck jaw body 42 and the chuck jaw tip 44 are both made of metal in order to provide sufficient strength to the chuck jaw 22 . In the preferred embodiment, the chuck jaw tip 44 and the channel shaped member 46 extend the full length of the chuck jaw body 42 . However, it is contemplated that the chuck jaw tip 42 and the channel-shaped member may terminate within the chuck jaw body 42 at a position just past the cutaway portion 48 . For reasons that will become apparent, the chuck jaw tip 44 needs to be completely electrically insulated from the chuck jaw body 42 . Accordingly, if the chuck jaw tip 44 does not extend the full length of the chuck jaw body 42 , the insulating channel-shaped member 46 must include an end cap that prevents the end of the tip 44 from contacting the jaw body 42 . Likewise, if the chuck jaw tip 44 does extend the full length of the chuck jaw body 42 , the top of the tip 44 in the area past the cutaway portion 48 must be fully enclosed within the channel shaped member 46 to prevent contact between the tip 44 and the chuck jaw body 42 .
The chuck jaw tip 44 is preferably adhesively bonded to the channel-shaped member 46 , and the channel-shaped member 46 is preferably adhesively bonded to the chuck jaw body 42 . In order to provide a more secure bond between the channel-shaped member 46 and both the chuck jaw body 42 and the chuck jaw tip 44 , a mechanical interlock may be formed between these components. This mechanical interlock may be used in addition to the adhesive, or in place of the adhesive, if desired. More specifically, as shown in FIG. 6, a mechanical interlock is formed between the channel-shaped member 46 and the chuck jaw body 42 by forming a generally dovetail-shaped interface therebetween. This dovetail-shaped interface includes a seating surface 50 recessed within the chuck jaw body 42 that corresponds to the outer perimeter 52 of the channel-shaped member 46 . The mechanical interlock securing the chuck tip 44 is preferably formed of a similar dovetail-shaped interface between a seating surface 54 recessed within the channel-shaped member 46 that corresponds to the outer periphery 56 of the chuck tip 44 . While one example of corresponding shapes suitable for use as a mechanical interlock has been shown and described, it is contemplated that mechanical interlocks of other shapes may also be utilized, such as those with multiple dovetail-shaped interfaces or with interfaces of complementary teeth of other shapes.
An important feature of the present invention is the manner in which the chuck jaws 22 prevent electric current from being transferred from the drill bit 24 to the remainder of the drill 10 . When the drill bit 24 is secured in position by the chuck jaws 22 , as shown in FIGS. 1 and 2, the metal chuck jaw tips 44 of each jaw 22 are contacting the drill bit 24 . Thus, any current that travels through the drill bit 24 (which is usually metal) will reach the chuck jaw tips 44 . However, because each of the jaw tips 44 are completely insulated from its associated chuck jaw body 42 by its channel-shaped member 46 , the electric current does not pass through to the chuck jaw body 42 . Accordingly, the electric current does not pass through to the remainder of the drill 10 . Thus, even if the operator makes contact with the metal sleeve 34 or metal chuck body 36 of the chuck assembly 20 while the drill bit 24 is conducting an electric current, the operator should not receive that current.
Turning now to FIGS. 7-10, a second preferred embodiment of the present insulated chuck jaws will now be described. For the sale of convenience, corresponding features of this embodiment have been given the same index numbers as those features of the first embodiment, with the addition of the prime symbol to each index number in the second embodiment.
In this embodiment, there is no channel-shaped insulating member (member 46 of the first embodiment). Instead, the entire chuck jaw body 42 ′ is formed of an insulating material. Thus, the chuck tip 44 ′, which is preferably formed of metal, is seated directly within the chuck jaw body 42 ′. Because the chuck jaw body 42 ′ is formed of an insulating material, it prevents electric current from passing through the chuck jaw tip 44 ′ to the remainder of the drill 10 .
As in the first embodiment, the components of this second embodiment are preferably secured together with adhesive, or with a mechanical interlock, or both. More specifically, the mechanical interlock may include a generally dovetail-shaped interface between a seating surface 54 ′ of the chuck body 42 ′ and the outer periphery 56 ′ of the chuck jaw tip 44 ′. Of course, other shapes for surfaces of the mechanical interlock are also contemplated.
In this embodiment, the chuck jaw tip 44 ′, which is preferably made of metal, preferably extends for the full length of the chuck jaw body 42 ′ to provide additional strength to the chuck jaw body 42 ′, which is preferably made of plastic. However, if the chuck jaw body 42 ′ can be made of a material of sufficient strength, while still providing the necessary insulating qualities, the chuck jaw tip 44 ′ need not extend for the full length of the chuck jaw body 42 ′, and instead, for example, may terminate at a point near the end of the cutaway portion 48 ′.
In operation, the second embodiment of the chuck jaw 22 ′ provides the same beneficial insulating properties as the first embodiment. Thus, the insulating chuck jaw body 42 ′ prevents current from being transferred from the chuck tip 44 ′ to the remainder of the drill 10 (or other rotatable power tool).
While various embodiments of the present invention have been shown and described, it should be understood that other modifications, substitutions and alternatives may be apparent to one of ordinary skill in the art. Such modifications, substitutions and alternatives can be made without departing from the spirit and scope of the invention, which should be determined from the appended claims.
Various features of the invention are set forth in the appended claims. | A chuck jaw that is configured and arranged to be used in combination with other chuck jaws for securely retaining a rotatable accessory, such as a drill bit, in position in a chuck assembly, where the chuck jaw includes a chuck jaw body that defines a generally longitudinal axis along the primary extension direction thereof and a chuck jaw tip that is positioned within the chuck jaw body and extends along at least a portion of the generally longitudinal axis of the chuck jaw body. The chuck jaw further includes an insulating material for preventing electrical current from passing between the rotatable accessory and the remainder of the chuck assembly via the chuck jaw. | 8 |
CROSS REFERENCE
This application claims priority under Title 35, United States Code 119(e) from Provisional Application Ser. No. 60/058,246, filed Sep. 9, 1997.
TECHNICAL FIELD
The subject invention relates to certain novel analogs of the naturally occurring prostaglandins. Specifically, the subject invention relates to novel Prostaglandin F analogs. The subject invention further relates to methods of using said novel Prostaglandin F analogs. Preferred uses include methods of treating bone disorders and glaucoma.
BACKGROUND OF THE INVENTION
Naturally occurring prostaglandins (PGA, PGB, PGE, PGF, and PGI) are C-20 unsaturated fatty acids. PGF 2 α, the naturally occurring Prostaglandin F in humans, is characterized by hydroxyl groups at the C 9 and C 11 positions on the alicyclic ring, a cis-double bond between C 5 and C 6 , and a trans-double bond between C 13 and C 14 . Thus PGF 2 α has the following formula: ##STR2##
Analogs of naturally occurring Prostaglandin F have been disclosed in the art. For example, see U.S. Pat. No. 4,024,179 issued to Bindra and Johnson on May 17, 1977; German Patent No. DT-002,460,990 issued to Beck, Lerch, Seeger, and Teufel published on Jul. 1, 1976; U.S. Pat. No. 4,128,720 issued to Hayashi, Kori, and Miyake on Dec. 5, 1978; U.S. Pat. No. 4,011,262 issued to Hess, Johnson, Bindra, and Schaaf on Mar. 8, 1977; U.S. Pat. No. 3,776,938 issued to Bergstrom and Sjovall on Dec. 4, 1973; P. W. Collins and S. W. Djuric, "Synthesis of Therapeutically Useful Prostaglandin and Prostacyclin Analogs", Chem. Rev. Vol. 93 (1993), pp. 1533-1564; G. L. Bundy and F. H. Lincoln, "Synthesis of 17-Phenyl-18,19,20-Trinorprostaglandins: I. The PG 1 Series", Prostaglandins, Vol. 9 No. 1 (1975), pp. 1-4; W. Bartman, G. Beck, U. Lerch, H. Teufel, and B. Scholkens, "Luteolytic Prostaglandins: Synthesis and Biological Activity", Prostaglandins, Vol. 17 No. 2 (1979), pp. 301-311; C. Iiljebris, G. Selen, B. Resul, J. Sternschantz, and U. Hacksell, "Derivatives of 17- Phenyl-18,19,20-trinorprostaglandin F 2 α Isopropyl Ester: Potential Antiglaucoma Agents", Journal of Medicinal Chemistry, Vol. 38 No. 2 (1995), pp. 289-304.
Naturally occurring prostaglandins are known to possess a wide range of pharmacological properties. For example, prostaglandins have been shown to: relax smooth muscle, which results in vasodilatation and bronchodilatation, to inhibit gastric acid secretion, to inhibit platelet aggregation, to reduce intraocular pressure, and to induce labor. Although naturally occurring prostaglandins are characterized by their activity against a particular prostaglandin receptor, they generally are not specific for any one prostaglandin receptor. Therefore, naturally-occurring prostaglandins are known to cause side effects such as inflammation, as well as surface irritation when administered systemically. It is generally believed that the rapid metabolism of the naturally occurring prostaglandins following their release in the body limits some of the effects of the prostaglandin to a local area. This effectively prevents the prostaglandin from stimulating prostaglandin receptors throughout the body and causing the effects seen with the systemic administration of naturally occurring prostaglandins.
Prostaglandins, especially prostaglandins of the E series (PGE), are known to be potent stimulators of bone resorption. PGF 2 α has also been shown to be a stimulator of bone resorption but not as potent as PGE 2 . Also, it has been demonstrated the PGF 2 α has little effect on bone formation. It has been suggested that some of the effects of PGF 2 α on bone resorption, formation and cell replication may be mediated by an increase in endogenous PGE 2 production.
In view of both the wide range of pharmacological properties of naturally occurring prostaglandins and of the side effects seen with the systemic administration of these naturally occurring prostaglandins, attempts have been made to prepare analogs to the naturally occurring prostaglandins that are selective for a specific receptor or receptors. A number of such analogs have been disclosed in the art. Though a variety of prostaglandin analogs have been disclosed, there is a continuing need for potent, selective prostaglandin analogs for the treatment of a variety diseases and conditions.
SUMMARY OF THE INVENTION
The invention provides novel PGF analogs. In particular, the present invention relates to compounds having a structure according to the following formula: ##STR3## wherein R 1 , R 2 , R 3 , R 4 , X, Y, and Z are defined below.
This invention also includes optical isomers, diastereomers and enantiomers of the formula above, and pharmaceutically-acceptable salts, biohydrolyzable amides, esters, and imides thereof.
The compounds of the present invention are useful for the treatment of a variety of diseases and conditions, such as bone disorders and glaucoma. Accordingly, the invention further provides pharmaceutical compositions comprising these compounds. The invention still further provides methods of treatment for bone disorders and glaucoma using theses compounds or the compositions containing them.
DETAILED DESCRIPTION OF THE INVENTION
Terms and Definitions
"Acyl` is a group suitable for acylating a nitrogen atom to form an amide or carbamate or an oxygen atom to form an ester group. Preferred acyl groups include benzoyl, acetyl, tert-butyl acetyl, para-phenyl benzoyl, and trifluoroacetyl. More preferred acyl groups include acetyl and benzoyl. The most preferred acyl group is acetyl.
"Alkyl" is a saturated or unsaturated hydrocarbon chain having 1 to 18 carbon atoms, preferably 1 to 12, more preferably 1 to 6, more preferably still 1 to 4 carbon atoms. Alkyl chains may be straight or branched. Preferred branched alkyl have one or two branches, preferably one branch. Preferred alkyl are saturated. Unsaturated alkyl have one or more double bonds and/or one or more triple bonds. Preferred unsaturated alkyl have one or two double bonds or one triple bond, more preferably one double bond. Alkyl chains may be unsubstituted or substituted with from 1 to about 4 substituents. Preferred alkyl are unsubstituted. Preferred substituted alkyl are mono-, di-, or trisubstituted. Preferred alkyl substituents include methyl, ethyl, propyl and butyl, halo, hydroxy, alkoxy (e.g., methoxy, ethoxy, propoxy, butoxy, pentoxy), aryloxy (e.g., phenoxy, chlorophenoxy, tolyloxy, methoxyphenoxy, benzyloxy, alkyloxycarbonylphenoxy, acyloxyphenoxy), acyloxy (e.g., propionyloxy, benzoyloxy, acetoxy), carbamoyloxy, carboxy, mercapto, alkylthio, acylthio, arylthio (e.g., phenylthio, chlorophenylthio, alkylphenylthio, alkoxyphenylthio, benzylthio, alkyloxycarbonylphenylthio), aryl (e.g., phenyl, tolyl, alkyloxphenyl, alkyloxycarbonylphenyl, halophenyl), heterocyclyl, heteroaryl, amino (e.g., amino, mono- and di- C 1 -C 3 alkanylamino, methylphenylamino, :methylbenzylamino, C 1 -C 3 alkanylamido, carbamamido, ureido, guanidino).
"Aromatic ring" is an aromatic hydrocarbon ring system. Aromatic rings are monocyclic or fused bicyclic ring systems. Monocyclic aromatic rings contain from about 5 to about 10 carbon atoms, preferably from 5 to 7 carbon atoms, and most preferably from 5 to 6 carbon atoms in the ring. Bicyclic aromatic rings contain from 8 to 12 carbon atoms, preferably 9 or 10 carbon atoms in the ring. Aromatic rings may be unsubstituted or substituted with from 1 to about 4 substituents on the ring. Preferred aromatic ring substituents include: halo, cyano, alkyl, heteroalkyl, haloalkyl, phenyl, phenoxy or any combination thereof. More preferred substituents include halo and haloalkyl. Preferred aromatic rings include naphthyl and phenyl. The most preferred aromatic ring is phenyl.
"Bone disorder" means the need for bone repair or replacement. Conditions in which the need for bone repair or replacement may arise include: osteoporosis (including post menopausal osteoporosis, male and female senile osteoporosis and corticosteroid induced osteoporosis), osteoarthritis, Paget's disease, osteomalacia, multiple myeloma and other forms of cancer, prolonged bed rest, chronic disuse of a limb, anorexia, microgravity, exogenous and endogenous gonadal insufficiency, bone fracture, non-union, defect, prosthesis implantation and the like.
"Carbocyclic aliphatic ring" is a saturated or unsaturated hydrocarbon ring. Carbocyclic aliphatic rings are not aromatic. Carbocyclic aliphatic rings are monocyclic, or are fused, spiro, or bridged bicyclic ring systems. Monocyclic carbocyclic aliphatic rings contain from about 4 to about 10 carbon atoms, preferably from 4 to 7 carbon atoms, and most preferably from 5 to 6 carbon atoms in the ring. Bicyclic carbocyclic aliphatic rings contain from 8 to 12 carbon atoms, preferably from 9 to 10 carbon atoms in the ring. Carbocyclic aliphatic rings may be unsubstituted or substituted with from 1 to about 4 substituents on the ring. Preferred carbocyclic aliphatic ring substituents include: halo, cyano, alkyl, heteroalkyl, haloalkyl, phenyl, phenoxy or any combination thereof. More preferred substituents include halo and haloalkyl. Preferred carbocyclic aliphatic rings include cyclopentyl, cyclohexyl, cyclohexenyl, cycloheptyl, and cyclooctyl. More preferred carbocyclic aliphatic rings include cyclohexyl, cycloheptyl, and cyclooctyl. The most preferred carbocyclic aliphatic ring is cycloheptyl.
"Halo" is fluoro, chloro, bromo or iodo. Preferred halo are fluoro, chloro and bromo; more preferred are chloro and fluoro, especially fluoro.
"Haloalkyl" is a straight, branched, or cyclic hydrocarbon substituted with one or more halo substituents. Preferred haloalkyl are C 1 -C 12 ; more preferred are C 1 -C 6 ; more preferred still are C 1 -C 3 . Preferred halo substituents are fluoro and chloro. The most preferred haloalkyl is trifluoromethyl.
"Heteroalkyl" is a saturated or unsaturated chain containing carbon and at least one heteroatom, wherein no two heteroatoms are adjacent. Heteroalkyl chains contain from 1 to 18 member atoms (carbon and heteroatoms) in the chain, preferably 1 to 12, more preferably 1 to 6, more preferably still 1 to 4. Heteroalkyl chains may be straight or branched. Preferred branched heteroalkyl have one or two branches, preferably one branch. Preferred heteroalkyl are saturated. Unsaturated heteroalkyl have one or more double bonds and/or one or more triple bonds. Preferred unsaturated heteroalkyl have one or two double bonds or one triple bond, more preferably one double bond. Heteroalkyl chains may be unsubstituted or substituted with from 1 to about 4 substituents. Preferred heteroalkyl are unsubstituted. Preferred heteroalkyl substituents include methyl, ethyl, propyl and butyl, halo, hydroxy, alkoxy (e.g., methoxy, ethoxy, propoxy, butoxy, pentoxy), aryloxy (e.g., phenoxy, chlorophenoxy, tolyloxy, methoxyphenoxy, benzyloxy, alkyloxycarbonylphenoxy, acyloxyphenoxy), acyloxy (e.g., propionyloxy, benzoyloxy, acetoxy), carbamoyloxy, carboxy, mercapto, alkylthio, acylthio, arylthio (e.g., phenylthio, chlorophenylthio, alkylphenylthio, alkoxyphenylthio, benzylthio, alkyloxycarbonylphenylthio), aryl (e.g., phenyl, tolyl, alkyloxphenyl, alkyloxycarbonylphenyl, halophenyl), heterocyclyl, heteroaryl, amino (e.g., amino, mono- and di- C 1 -C 3 alkanylamino, methylphenylamino, methylbenzylamino, C 1 -C 3 alkanylamido, carbamamido, ureido, guanidino).
"Heteroatom" is a nitrogen, sulfur, or oxygen atom. Groups containing more than one heteroatom may contain different heteroatoms.
"Heterocyclic aliphatic ring" is a saturated or unsaturated ring containing carbon and from 1 to about 4 heteroatoms in the ring, wherein no two heteroatoms are adjacent in the ring and no carbon in the ring that has a heteroatom attached to it also has a hydroxyl, amino, or thiol group attached to it. Heterocyclic aliphatic rings are not aromatic. Heterocyclic aliphatic rings are monocyclic, or are fused or bridged bicyclic ring systems. Monocyclic heterocyclic aliphatic rings contain from about 4 to about 10 member atoms (carbon and heteroatoms), preferably from 4 to 7, and most preferably from 5 to 6 member atoms in the ring. Bicyclic heterocyclic aliphatic rings contain from 8 to 12 member atoms, preferably 9 or 10 member atoms in the ring. Heterocyclic aliphatic rings may be unsubstituted or substituted with from 1 to about 4 substituents on the ring. Preferred heterocyclic aliphatic ring substituents include: halo, cyano, alkyl, heteroalkyl, haloalkyl, phenyl, phenoxy or any combination thereof. More preferred substituents include halo and haloalkyl. Preferred heterocyclic aliphatic rings include piperzyl, morpholinyl, tetrahydrofuranyl, tetrahydropyranyl and piperdyl.
"Heteroaromatic ring" is an aromatic ring system containing carbon and from 1 to about 4 heteroatoms in the ring. Heteroaromatic rings are monocyclic or fused bicyclic ring systems. Monocyclic heteroaromatic rings contain from about 5 to about 10 member atoms (carbon and heteroatoms), preferably from 5 to 7, and most preferably from 5 to 6 member atoms in the ring. Bicyclic heteroaromatic rings contain from 8 to 12 member atoms, preferably 9 or 10 member atoms in the ring. Heteroaromatic rings may be unsubstituted or substituted with from 1 to about 4 substituents on the ring. Preferred heteroaromatic ring substituents include: halo, cyano, alkyl, heteroalkyl, haloalkyl, phenyl, phenoxy or any combination thereof. More preferred substituents include halo, haloalkyl, and phenyl. Preferred heteroaromatic rings include thienyl, thiazolo, purinyl, pyrimidyl, pyridyl, and furanyl. More preferred heteroaromatic rings include thienyl, furanyl, and pyridyl. The most preferred heteroaromatic ring is thienyl.
"Lower alkyl" is an alkyl chain radical comprised of 1 to 6, preferably 1 to 4 carbon atoms.
"Phenyl" is a six-membered monocyclic aromatic ring which may or may not be substituted with from about 1 to about 4 substituents. The substituents may be substituted at the ortho, meta or para position on the phenyl ring, or any combination thereof. Preferred phenyl substituents include: halo, cyano, alkyl, heteroalkyl, haloalkyl, phenyl, phenoxy or any combination thereof. More preferred substituents on the phenyl ring include halo and haloalkyl. The most preferred substituent is halo. The preferred substitution pattern on the phenyl ring is ortho or meta. The most preferred substitution pattern on the phenyl ring is ortho.
Compounds
The subject invention involves compounds having the following structure: ##STR4##
In the above structure, R 1 is CO 2 H, C(O)NHOH, CO 2 R 5 , CH 2 OH, S(O) 2 R 5 , C(O)NHR 5 , C(O)NHS(O) 2 R 5 , or tetrazole; wherein R 5 is alkyl, heteroalkyl, carbocyclic aliphatic ring, heterocyclic aliphatic ring, aromatic ring, or heteroaromatic ring. Preferred R 5 is CH 3 , C 2 H 5 , C 3 H 7 . Preferred R 1 is CO 2 H, C(O)NHOH, CO 2 CH 3 , CO 2 C 2 H 5 , CO 2 C 3 H 7 , CO 2 C 4 H 9 , CO 2 C 3 H 7 O 2 , and C(O)NHS(O) 2 R 5 . More preferred R 1 is CO 2 H, C(O)NHOH, CO 2 CH 3 , and CO 2 C 3 H 5 . Most preferred R 1 is CO 2 H and CO 2 CH 3 .
In the above structure, R 2 is H or lower alkyl. Preferred R 2 is H and CH 3 . Most preferred R 2 is H.
In the above structure, X is NR 6 R 7 , OR 8 , SR 9 , S(O)R 9 , S(O) 2 R 9 , or F; wherein R 6 , R 7 , and R 8 are independently selected from the group consisting of H, acyl, alkyl, heteroalkyl, carbocyclic aliphatic ring, heterocyclic aliphatic ring, aromatic ring, and heteroaromatic ring; and wherein R 9 is alkyl, heteroalkyl, carbocyclic aliphatic ring, heterocyclic aliphatic ring, aromatic ring, or heteroaromatic ring. Preferred R 6 and R 7 are H, CH 3 and C 2 H 5 . Preferred R 8 is H, CH 3 , C 2 H 5 , and C 3 H 7 . Preferred R 9 is CH 3 and C 2 H 5 . Preferred X is NR 6 R 7 and OR 8 . Most preferred X is OH.
In the above structure, R 3 and R 4 are independently H, CH 3 , C 2 H 5 , OR 10 , SR 10 , or OH, except that both R 3 and R 4 are not OH; wherein R 10 is alkyl, heteroalkyl, carbocyclic aliphatic ring, heterocyclic aliphatic ring, aromatic ring, or heteroaromatic ring, R 10 having from 1 to about 8 member atoms. Preferred R 3 and R 4 are H.
In the above structure, Y is (CH 2 ) n ; n being an integer from 0 to about 3. Preferred n is 0,1, and 2. Most preferred n is 1.
In the above structure, Z is carbocyclic aliphatic ring, heterocyclic aliphatic ring, monocyclic heteroaromatic ring, or substituted phenyl when n is 0, 2, or 3; and Z is carbocyclic aliphatic ring, heterocyclic aliphatic ring, or substituted phenyl when n is 1. Preferred Z is monocyclic. More preferred Z is substituted phenyl and monocyclic heteroaromatic ring. The most preferred Z is substituted phenyl and substituted or unsubstituted thienyl.
The invention also includes optical isomers, diastereomers and enantiomers of the above structure. Thus, at all stereocenters where stereochemistry is not defined (C 11 , C 12 , C 15 , and C 16 ), both epimers are envisioned. Preferred stereochemistry at all such stereocenters of the compounds of the invention mimic that of naturally occurring PGF 22 .
It has been discovered that the novel PGF analogs of the subject invention are useful for treating bone disorders, especially those that require a significant increase in bone mass, bone volume, or bone strength. Surprisingly, the compounds of the subject invention have been found to provide the following advantages over known bone disorder therapies: (1) An increase trabecular number through formation of new trabeculae; (2) An increase in bone mass and bone volume while maintaining a more normal bone turnover rate; and (3) An increase in bone formation at the endosteal surface without increasing cortical porosity.
In order to determine and assess pharmacological activity, testing of the subject compounds in animals is carried out using various assays known to those skilled in the art. For example, the bone activity of the subject compounds can be conveniently demonstrated using an assay designed to test the ability of the subject compounds to increase bone volume, mass, or density. An example of such assays is the ovariectomized rat assay.
In the ovariectomized rat assay, six-month old rats are ovariectomized, aged 2 months, and then dosed once a day subcutaneously with a test compound. Upon completion of the study, bone mass and/or density can be measured by dual energy x-ray absorptometry (DXA) or peripheral quantitative computed tomography (pQCT), or micro computed tomography (mCT). Alternatively, static and dynamic histomorphometry can be used to measure the increase in bone volume or formation.
Pharmacological activity for glaucoma can be demonstrated using assays designed to test the ability of the subject compounds to decrease intraocular pressure. Examples of such assays are described in the following reference, incorporated herein: C. Iiljebris, G. Selen, B. Resul, J. Sternschantz, and U. Hacksell, "Derivatives of 17- Phenyl-18,19,20-trinorprostaglandin F 2 α Isopropyl Ester: Potential Antiglaucoma Agents", Journal of Medicinal Chemistry, Vol. 38 No. 2 (1995), pp. 289-304.
Compounds useful in the subject invention can be made using conventional organic syntheses. A particularly preferred synthesis is the following general reaction scheme: ##STR5##
In Scheme 1, R 1 , R 2 , R 3 , R 4 , X, Y, and Z are as defined above. The Corey Lactone (S1a) depicted as starting material for Scheme 1 is commercially available (such as from Sumitomo Chemical or Cayman Chemical).
Compounds depicted by S1f are available from compounds of the type depicted by S1e via standard reduction reactions. Compounds depicted by Formula I are available from compounds of S1f via simultaneous saturation of the double bonds of S1f. Compounds depicted by Formula I are exemplified in Examples 2, 4, 5, 7, 9, 11, 13, 16, 18, 20, 22, 24, 26, and 28. Compounds depicted by Formula II are prepared through a simple deesterification protocol of the compounds of Formula I. Compounds depicted by Formula II are exemplified in Examples 1, 3, 6, 8, 10, 12, 14, 15, 17, 19, 21, 23, 25, 27, and 29. Compounds depicted by Formula III can be prepared from compounds such of S1e via the addition of a carbon nucleophile followed by saturation and saponification. Compounds depicted by Formula III are exemplified in Examples 43 and 44. Compounds depicted by Formula IV can be prepared via imine formation followed by imine reduction, N-alkylation, hydrogenation, and saponification. Additional compounds depicted by Formula IV can be prepared via imine formation, as previously mentioned, followed by nucleophilic addition to the resulting imine followed by double bond saturation and saponification. Compounds depicted by Formula IV are exemplified in Examples 48, 49, and 50.
Compounds depicted by Formula V and Formula VII can be prepared through dihydroxyl protection of compounds of S1e followed by standard nucleophilic reduction of the ketone. The resulting free alcohol can be activated and displaced with nucleophiles such as, but not limited to, fluoride, alkoxide or sulfide to give compounds depicted by Formula V or Formula VII. Compounds depicted by Formula V are exemplified in Examples 36, 37, and 38. Compounds depicted by Formula VII are exemplified in Examples 39, 40, 41, 42, and 45. Compounds depicted by Formula VIII are prepared by the selective oxidation of compounds of Formula VII with the proviso that X must be sulfur. Compounds depicted by Formula VIII are exemplified in Examples 46 and 47. Compounds of the type depicted by Formula VI can be prepared from either compounds of Formula I or Formula II (compounds depicted by Formula II may require carboxylate activation) through nucleophilic addition to an activated carboxylate to produce an amide or new ester linkage to give the resulting hydroxamic acid, sulfonamide, or ester. Compounds depicted by Formula VI are exemplified in Examples 30-35.
The following non-limiting examples illustrate the compounds, compositions, and uses of the present invention.
EXAMPLES
Compounds are analyzed using 1 H and 13 C NMR, Elemental analysis, mass spectra, high resolution mass spectra and/or IR spectra as appropriate.
Typically, inert solvents are used, preferably in dried form. For example, tetrahydrofuran (THF) is distilled from sodium and benzophenone, diisopropylamine is distilled from calcium hydride and all other solvents are purchased as the appropriate grade. Chromatography is performed on silica gel (70-230 mesh; Aldrich) or (230-400 mesh; Merck) as appropriate. Thin layer chromatography analysis is performed on glass mounted silica gel plates (200-300 mesh; Baker) and visualized using UV, 5% phosphomolybdic acid in EtOH, potassium permanganate in water, iodine, p-anisaldehyde in ethanol, or ammonium molybdate/cerric sulfate in 10% aqueous H 2 SO 4 .
Example 1
Preparation of 13,14-dihydro-17-(3-fluorophenyl)-17-trinor-prostaglandin F 1 α ##STR6## a. 7-benzoyloxy-6-(2,5-dioxolanyl)-2-oxabicyclo[3.3.0]octan-3-one (1b):
In a round-bottomed flask equipped with a magnetic stir bar is placed 1,2-bis(trimethylsilyloxy)ethane (1.3 equiv.) in methylene chloride containing trimethysilyltrifluoromethanesulfonate (1 mL) at -78° C. To this is added, within 20 minutes, a solution of 1a (1 equiv) in CH 2 Cl 2 . The reaction is stirred for 1 hour at -78° C. and then slowly warmed to 25° C. for 1 hour. The reaction is quenched at 0° C. with water, extracted with CH 2 Cl 2 , dried over MgSO 4 , and concentrated in vacuo to give crude 1b.
b. 6-(2,5-dioxolanyl)-7-hydroxy-2-oxabicyclo[3.3.0]octan-3-one (1c):
To a well stirred solution of crude 1b (1 equiv) in methanol at 0° C. is added a suspension of sodium methoxide (1.2 equiv) in MeOH. The reaction stirred at 0° C. for 1 hour and then warmed to 25° C. for 1 hour. The reaction is neutralized with acidic ion exchange resin which is washed thoroughly with MeOH. The filtrate is concentrated in vacuo to give a syrup which is subjected to flash chromatography on silica gel eluting with 4:1 hexane:ethyl acetate and 2% MeOH in CH 2 Cl 2 to give 1c as a yellow syrup.
c. 6-(2,5dioxolanyl)-2-oxa-7-(1,1,2,2-tetramethyl-1-silapropoxy) bicyclo[3.3.0]octan-3-one (1d):
In a round-bottomed flask with a magnetic stir bar, is stirred a solution of 1c (1 equiv) in CH 2 Cl 2 . To this solution is added dropwise at -78° C. 2,6-lutidine (1.9 equiv) followed by TBDMSOTf (1.8 eq). The reaction stirred for 30 minutes at -78° C. and then warmed to 25° C. overnight. The reaction is quenched with water. The organic layer is washed with water, dried over MgSO 4 , and concentrated in vacuo to give a yellow oil which is subjected to flash chromatography on silica gel eluting with hexanes then 1% MeOH in CH 2 Cl 2 . The product is then washed with 1N HCl, 0.1N HCl, water, and brine to give 1d.
d. 6-(2,5dioxolanyl)-2-oxa-7-(1,1,2,2-tetramethyl-1-silapropoxy) bicyclo[3.3.0]octan-2-ol (1e):
In a round-bottomed flask with a magnetic stir bar, is stirred a solution of 1d (1 equiv) in dry toluene. To this solution, at -78° C., is slowly added DIBAL (1.24 equiv). The reaction mixture is stirred for 2 hours and then warmed to 0° C. Saturated NH 4 Cl is added to the reaction mixture which is then slowly warmed to 25° C. Diluted with water, the insoluble precipitate is removed by suction filtration and the solid is washed with EtOAc. The liquid phase is extracted with EtOAc and the combined organic phase is dried over MgSO 4 and concentrated in vacuo to give a yellow syrup. The product, 1e, must either be used immediately or stored at -70° C. overnight.
e. methyl 7-(5-(2,5-dioxolanyl)-2-hydroxy-4-(1,1,2,2-tetramethyl-(1-silapropoxy)cyclopentyl)hept-5-enoate (1f):
To a suspension of (4-carboxybutyl)triphenylphosphonium bromide (2.2 equiv) in THF at 0° C. under N 2 is added dropwise a solution of KHMDS (4.4 equiv). The resulting deep orange color reaction mixture is stirred for 1 hour at 25° C. To the reaction mixture above at -78° C. is added a solution of 1e (1 equiv) in THF. The reaction mixture is allowed to warm to 25° C. overnight. The reaction is quenched with water at 0° C. and the pH is adjusted to 3.5-4.0 with 1N HCl. The water phase is extracted with EtOAc and the combined organic phase is dried over MgSO 4 and is concentrated in vacuo to give a reddish-brown syrup containing crude acid. To a well stirred solution of crude acid in ether and MeOH at 0° C. is added TMS-diazomethane until a yellow color persists. The addition of 1 drop of glacial acetic acid, and thin layer chromatography verifies the reaction has gone to completion. The reaction solution is concentrated in vacuo and purified via flash chromatography on silica gel eluting with 30% EtOAc in hexanes yielding 1f.
f. methyl 7-(2,4-dihydroxy-5-formyl-cyclopentyl)hept-5-enoate (1g):
In a round-bottomed flask with a magnetic stir bar is placed an amount of the ketal, 1f. To this flask is added a sufficient amount of a mixture of 2 parts acetone to 1 part 1N HCl to bring the ketal completely into solution. This material is stirred until, by TLC, the starting material is consumed, typically overnight. The crude mixture, containing the product 1g, is extracted with ether, and the ether extract re-esterified in situ with, preferably, TMS-diazomethane. The organic extracts were concentrated under reduced pressure at 0° C. and used immediately without further purification.
g. Methyl 3-(2-fluorophenyl)propionate (1i):
In a Parr vessel is placed 2-fluorocinnamic acid (1h) (1.0 equiv) and palladium on carbon in a 1/1 methanol/ethyl acetate solution. The heterogeneous solution is placed on a Parr shaker and treated with hydrogen (50 psi) until uptake has ceased. The mixture is filtered through Celite and concentrated under reduced pressure. The residue is taken up in diethyl ether and treated with diazomethane until a yellow color persists. The solution is concentrated under reduced pressure to give the crude methyl ester. Purification is effected by column chromatography on silica gel (hexane/ethyl acetate 5/1) to yield Methyl 3-(2-fluorophenyl)propionate (1i) in quantitative yield.
h. Dimethyl-4-(2-fluorophenyl)-2-oxo-butylphosphonate (1j):
In a flame-diried, round-bottomed flask equipped with a stir bar and thermometer is placed dimethylmethyl phosphonate (1.0 equiv.) in anhydrous THF. The solution is cooled to -78° C. and treated with n-butyllithium (1.05 equiv.). The reaction mixture is allowed to stir for 15 minutes. To this solution is added methyl-3-(2-fluorophenyl)propionate (1.1 equiv.) in anhydrous THF. The mixture is allowed to warm to room temperature over the next 6 hours. The mixture is treated with a saturated solution of ammonium chloride and extracted with CH 2 Cl 2 . The organic layer is washed with water followed by brine. The combined aqueous layers are back extracted with CH 2 Cl 2 and the organic layers combined, dried over anhydrous MgSO 4 , filtered, and concentrated under reduced pressure. Purification is effected by silica gel column chromatography (hexane/ethyl acetate/2-propanol 45/50/5 to hexane/ethyl acetate/2-propanol 40/50/10) to yield 1.34 g (70%) of dimethyl-4-(2-fluorophenyl)-2-oxo-butylphosphonate (1j) as an oil.
i. 17-(2-fluorophenyl)-17-trinor-15-oxo-prostaglandin F 2a methyl ester (1k):
In a flame-dried, round-bottomed flask equipped with a magnetic stirbar is placed dimethyl-4-(2-fluorophenyl)-2-oxo-butylphosphonate (1j) (1.43 equiv) in DME and water. To this solution is added lithium bromide (1.65 equiv), triethylamine (1.65 equiv), and methyl 7-(2-formyl-3,5-dihydroxycyclopentyl)hept-5-enoate (1g) (1.0 equiv). The solution is stirred at room temperature for 48 hours. At this point additional triethylamine and water is added and the solution is stirred for an additional hour. The solution is poured into brine and extracted with 3 portions of ethyl acetate. The organic layers are combined, dried over anhydrous MgSO 4 , filtered, and concentrated under reduced pressure. Purification is effected by silica gel column chromatography (dichloromethane/methanol 19/1) to give 17-(2-fluorophenyl)-17-trinor-15-oxo-prostaglandin F 2a methyl ester (1k) as an oil.
j. 15-(R,S)-17-(2-fluorophenyl)-17-trinor-prostaglandin F 2a methyl ester (1l):
In a flame-dried round-bottomed flask equipped with a stir bar is placed 17-(2-fluorophenyl)-17-trinor-15-oxo-prostaglandin F 2a methyl ester (1k) (1.0 equiv), cerium trichloride (1.05 equiv) in methanol. The solution is stirred at room temperature for 5 minutes. The solution is cooled to -10° C. and sodium borohydride (1.02 equiv.) in methanol is added. The solution is stirred at -10° C. for 3 hours. The mixture is treated with water and the pH brought to 6-7 with 1N hydrochloric acid. The mixture is extracted twice with ethyl acetate, and the organic layers combined, dried over anhydrous MgSO 4 , filtered and concentrated under reduced pressure. Purification was effected by silica gel column chromatography (3% methanol in dichloromethane to 5% methanol in dichloromethane) to give (43%) of the 15 (R) epimer and (19.6%) of the 15 (S) epimer as colorless oils.
k. 13,14-dihydro-17-(2-fluorophenyl)-17-trinor-prostaglandin F 1 α methyl ester (1m):
In a flame-dried round-bottomed flask equipped with a stir bar was placed 17-(2-fluorophenyl)-17-trinor-prostaglandin F 2a methyl ester (1l) (1.0 equiv.) and palladium on carbon in ethyl acetate (3 mL). The heterogeneous mixture is treated with hydrogen via a balloon for 18 hours. The mixture is filtered through Celite and concentrated under reduced pressure to give a quantitative yield 13,14-dihydro-17-(2-fluorophenyl)-17-trinor-prostaglandin F 1 α methyl ester (1m).
l. 13,14-dihydro-17-(2-fluorophenyl)-17-trinor-prostaglandin F 1 α methyl ester (1n):
In a round-bottomed flask equipped with a stir bar is placed 13,14-dihydro-17-(2-fluorophenyl)-17-trinor-prostaglandin F 1 α methyl ester (1m) (1.0 equiv) and lithium hydroxide monohydrate (1.8 equiv) in a 50/50 THF water solution. The mixture is stirred at room temperature for 6 hours and then diluted with water and acidified to pH 2-3 with 1N HCl. The aqueous phase is extracted 3 times with ethyl acetate and the organic layers combined. The combined organics were dried over anhydrous MgSO 4 , filtered, and concentrated under reduced pressure to yield the crude acid. Purification was effected by HPLC to yield (41%) of an analytical sample. Utilizing substantially the method of Example 1 (and using the appropriate starting materials), the following subject compounds of Examples 2-29 are obtained.
Example 2
13,14-dihydro-17-(2,4difluorophenyl)-17-trinor prostaglandin F 1 α methyl ester ##STR7##
Example 3
13,14-dihydro-17-(2,4difluorophenyl)-17-trinor prostaglandin F 1 α ##STR8##
Example 4
13,14-dihydro-17-(2-fluorophenyl)-17-trinor prostaglandin F 1 α methyl ester ##STR9##
Example 5
13,14-dihydro-17-(3-fluorophenyl)-17-trinor prostaglandin F 1 α methyl ester ##STR10##
Example 6
13,14-dihydro-17-(3-fluorophenyl-17-trinor prostaglandin F 1 α ##STR11##
Example 7
13,14-dihydro-17-(4-fluorophenyl)-17-trinor prostaglandin F 1 α methyl ester ##STR12##
Example 8
13,14-dihydro-17-(4-fluorophenyl)-17-trinor prostaglandin F 1 α ##STR13##
Example 9
13,14-dihydro-17-(2-methoxyphenyl)-17-trinor prostaglandin F 1 α methyl ester ##STR14##
Example 10
13,14-dihydro-17-(2-methoxyphenyl)-17-trinor prostaglandin F 1 α ##STR15##
Example 11
13,14-dihydro-17-(3-methoxyphenyl)-17-trinor prostaglandin F 1 α methyl ester ##STR16##
Example 12
13,14-dihydro-17-(3-methoxyphenyl)-17-trinor prostaglandin F 1 α ##STR17##
Example 13
13,14-dihydro-17-(4-methoxyphenyl)-17-trinor prostaglandin F 1 α methyl ester ##STR18##
Example 14
13,14-dihydro-17-(4-methoxyphenyl)-17-trinor prostaglandin F 1 α ##STR19##
Example 15
13,14-dihydro-17-(3,5-difluorophenyl)-17-trinor prostaglandin F 1 α ##STR20##
Example 16
13,14-dihydro-18-(2-thienyl)-18-dinor prostaglandin F 1 α methyl ester ##STR21##
Example 17
13,14-dihydro-18-(2-thienyl)-18-dinor prostaglandin F 1 α ##STR22##
Example 18
13,14-dihydro-17-((2-trifluoromethyl)phenyl)-17-trinor prostaglandin F 1 α methyl ester ##STR23##
Example 19
13,14-dihydro-17-((2-trifluoromethyl)phenyl)-17-trinor prostaglandin F 1 α ##STR24##
Example 20
13,14-dihydro-17-((3-trifluoromethyl)phenyl)-17-trinor prostaglandin F 1 α methyl ester ##STR25##
Example 21
13,14-dihydro-17-((3-trifluoromethyl)phenyl)-17trinor prostaglandin F 1 α ##STR26##
Example 22
13,14-dihydro-17-((4-trifluoromethyl)phenyl)-17-trinor prostaglandin F 1 α methyl ester ##STR27##
Example 23
13,14-dihydro-17-((4-trifluoromethyl)phenyl)-17-trinor prostaglandin F 1 α ##STR28##
Example 24
13,14-dihydro-17-(2-methylphenyl-17-trinor prostaglandin F 1 α methyl ester ##STR29##
Example 25
13,14-dihydro-17-(2-methylphenyl)-17-trinor prostaglandin F 1 α ##STR30##
Example 26
13,14-dihydro-17-(3-methylphenyl)-17-trinor prostaglandin F 1 α methyl ester ##STR31##
Example 27
13,14-dihydro-17-(3-methylphenyl)-17-trinor prostaglandin F 1 α ##STR32##
Example 28
13,14-dihydro-17-(4-methylphenyl)-17-trinor prostaglandin F 1 α methyl ester ##STR33##
Example 29
13,14-dihydro-17-(4-methylphenyl)-17-trinor prostaglandin F 1 α ##STR34##
Example 30
13,14-dihydro-17-((3-trifluoromethyl)phenyl)-17-trinor prostaglandin F 1 α -1-hydroxamic acid ##STR35##
To a solution of 13,14-dihydro-17-(3-trifluoromethyl)-phenyl trinor prostaglandin F 1 α methyl ester (Example 20) in methanol is added hydroxylamine in basic methanol (1.25 equiv.). The solution is stirred at room temperature for 18 hours. The solution is treated with 1N hydrochloric acid and extracted with ethyl acetate. The organic layer is washed with brine and dried over anhydrous magnesium sulfate, filtered and concentrated under reduced pressure. The residue is purified by HPLC to yield 13,14-dihydro-17-((3-trifluoromethyl)phenyl)-17-trinor prostaglandin F 1 α -1-hydroxamic acid.
Utilizing substantially the method of Example 30 (and using the appropriate ester), the following subject compounds of Examples 31 and 32 are obtained.
Example 31
13,14-dihydro-17-(2-methoxyphenyl)-17-trinor prostaglandin F 1 α -1-hydroxamic acid ##STR36##
Example 32
13,14-dihydro-18-(2-thienyl)-dinor prostaglandin F 1 α -1-hydroxamic acid ##STR37##
Example 33
13,14-dihydro-17-((4-trifluoromethyl)phenyl)-17-trinor prostaglandin F 1 α -1-sulfonamide ##STR38##
Example 23 is converted to the anhydride followed by treatment with methanesulfonylamide as disclosed in A. D. Kemp and H. Stephen, J. Chem. Soc. (1948) p. 110.
Utilizing substantially the method of Example 33 (and using the appropriate acid), the following subject compounds of Examples 34 and 35 are obtained.
Example 34
13,14-dihydro-17-(4-methylphenyl)-17-trinor prostaglandin F 1 α -1-sulfonamide ##STR39##
Example 35
13,14-dihydro-17-(2,4difluorophenyl)-17-trinor prostaglandin F 1 α -1-sulfonamide ##STR40##
Example 36
13,14-dihydro-15-fluoro-17-(3-methylphenyl)-17-trinor prostaglandin F 1 α ##STR41##
The precursor to Example 27 corresponding to 1k from Example 1 is protected and reduced to give the 9,11-protected bis ether. The resulting compound is treated with diethylaminosulfur trifluoride (DSAT) (as disclosed in the following references: Org. React. Vol. 35 (1988) p. 513; J. Org. Chem. Vol. 40 (1975) p. 574; and references cited therein) to give 13,14-dihydro-15-fluoro-17-(3-methylphenyl)-17-trinor prostaglandin F 1 α after the appropriate transformation as described in Example 1.
Examples 37 and 38 are prepared in a manner substantially similar to Example 36 using the appropriate intermediate corresponding to 1k (from Example 5 and Example 25 respectively) in Example 1 followed by standard esterification with the appropriate alcohol.
Example 37
13,14-dihydro-15-fluoro-17-(3-fluorophenyl)-17-trinor prostaglandin F 1 α ethyl ester ##STR42##
Example 38
13,14-dihydro-15-fluoro-17-(2-methylphenyl)-17-trinor prostaglandin F 1 α isopropyl ester ##STR43##
Example 39
13,14-dihydro-15-methylthio-17-((4-trifluoromethyl)phenyl)-17-trinor prostaglandin F 1 α ##STR44##
The precursor to Example 23 corresponding to 1k from Example 1 is protected and reduced to give the 9,11-protected bis ether. This compound is treated with methanesulfonyl chloride (1.2 equiv) and base (1.2 equiv) (as disclosed in the following references: J.C.S. Chem. Comm. (1975) p. 658; Tetrahedron Lett. (1975) p. 3183; and references cited therein) to generate the intermediate mesylate, which is then treated immediately with nucleophiles (sodium thiomethoxide) (as disclosed in Tetrahedron Lett. Vol. 23 (1982) p. 3463 and references cited therein.) to give the protected thioalkyl ether. Subsequent transformation as described in Example 1 provides 13,14-dihydro-15-methylthio-17-((4-trifluoromethyl)phenyl)-17-trinor prostaglandin F 1 α.
Example 40 is prepared in a manner substantially similar to Example 39 (from a precursor corresponding to 1k from Example 7) followed by conversion to the hydroxamic acid as shown in Example 30.
Example 40
13,14-dihydro-15-methylthio-17-(4-fluorophenyl)-17-trinor prostaglandin F 1 α hydroxamic acid ##STR45##
Example 41 is prepared in a substantially similar manner as Example 39 (from a precursor corresponding to 1k from Example 21) followed by conversion to the sulfonamide as shown in Example 33.
Example 41
13,14-dihydro-15-methylthio-17-((3-trifluoromethyl)phenyl)-17-trinor prostaglandin F 1 α -sulfonamide ##STR46##
Example 42
13,14-dihydro-15-ethoxy-17-((2-trifluoromethyl)phenyl)-17-trinor prostaglandin F 1 α ##STR47##
The precursor to Example 19 corresponding to 1k from Example 1 is protected and reduced to give the 9,11-protected bis ether. This compound is treated with methanesulfonyl chloride (1.2 equiv.) and base (1.2 equiv.) (as disclosed in the following references: J.C.S. Chem. Comm. (1975) p. 658; Tetrahedron Lett. (1975) p. 3183; and references cited therein.) to generate the intermediate mesylate, which is then treated immediately with sodium ethoxide to give the protected alkyl ether. Subsequent transformation as described in Example 1 provides 13,14-dihydro-15-ethoxy-17-((2-trifluoromethyl)phenyl)-17-trinor prostaglandin F 1 α.
Example 43
13,14-dihydro-15-ethyl-18-(2-thienyl)-18-dinor prostaglandin F 1 α ##STR48##
The precursor to Example 17 corresponding to 1k from Example 1 is protected and reduced to give the 9,11-protected bis ether. The resulting protected diol is treated with one of a variety of carbon nucleophiles, such as ethyl magnesium bromide to give the resulting tertiary alcohol. Deprotection followed by the transformation outlined in Example 1 provides 13,14-dihydro-15-ethyl-18-(2-thienyl)-18-dinor prostaglandin F 1 α.
Utilizing substantially the method of Example 43 (and using the appropriate carbon nucleophile), the following subject compound of Example 44 is obtained.
Example 44
13,14-dihydro-15-methyl-17-(3,5-difluorophenyl)-17-trinor prostaglandin F 1 α ##STR49##
Example 45
13,14-dihydro-15-ethyl-15-methoxy-17-(4-methoxyphenyl)-17-trinor prostaglandin F 1 α ##STR50##
The compound of Example 45 is prepared by utilizing the protocol outlined in Example 43 (from the precursor corresponding to 1k for Example 13) followed by O-alkylation of the resulting C 15 alkoxide with a variety of alkyl halides (iodomethane in this example). This is followed by deprotection, hydrogenation, and saponificiation as outlined in Example 43 and Example 1 to give 13,14-dihydro-15-ethyl-15-methoxy-17-(4-methoxyphenyl)-17-trinor prostaglandin F 1 α
Example 46
13,14-dihydro-15-sulfonylmethyl-17-((4-trifluoromethyl)phenyl)-17-trinor prostaglandin F 1 α ##STR51##
The thiomethyl ether of Example 39 is treated with the appropriate oxidizing agent as disclosed in the following references: Tetrahedron Lett. (1982) p. 3467; Prostaglandins Vol. 24 (1982) p. 801; Tetrahedron Lett. Vol. 23 (1982) p. 1023; and references cited therein.
Utilizing substantially the method of Example 46 (and using the appropriate thioether), the following subject compound of Example 47 is obtained.
Example 47
13,14-dihydro-15-sulfoxylmethyl-17-((4-trifluoromethyl)phenyl)-17-trinor prostaglandin F 1 α ##STR52##
Example 48
13,14-dihydro-15-N-methylamino-17-(3-methoxyphenyl)-17-trinor prostaglandin F 1 α ##STR53##
The intermediate of Example 12 corresponding to 1k is condensed with methyl amine followed by reduction with sodium cyanoborohydride to give 13,14-dihydro-15-N-methylamino-17-(3-methoxyphenyl)-17-trinor prostaglandin F 1 α, after saponification and deprotection.
Example 49
13,14-dihydro-15-N,N'-dimethylamino-17-(3-methoxyphenyl)-17-trinor prostaglandin F 1 α ##STR54##
The compound of Example 49 is prepared from the compound of Example 48 by simple alkylation with iodomethane.
Example 50
13,14-dihydro-15-aminomethyl-15-methyl-17-(3-methoxyphenyl)-17-trinor prostaglandin F 1 α ##STR55##
The intermediate imine of Example 48 is treated with methylcerium (excess) (for examples of cerium-mediated nucleophilic additions see the following references: J. Org. Chem., Vol. 49 (1984) p. 3904; J. Am. Chem. Soc., Vol. 111 (1989) p. 4392; and references therein) to give 13,14-dihydro-15-aminomethyl-15-methyl-17-(3-methoxyphenyl)-17-trinor prostaglandin F 1 α after hydrogenation and saponification as described in Example 1.
Compositions
Compositions of the subject invention comprise a safe and effective amount of the subject compounds, and a pharmaceutically-acceptable carrier. As used herein, "safe and effective amount" means an amount of a compound sufficient to significantly induce a positive modification in the condition to be treated, but low enough to avoid serious side effects (at a reasonable benefit/risk ratio), within the scope of sound medical judgment. A safe and effective amount of a compound will vary with the particular condition being treated, the age and physical condition of the patient being treated, the severity of the condition, the duration of the treatment, the nature of concurrent therapy, the particular pharmaceutically-acceptable carrier utilized, and like factors within the knowledge and expertise of the attending physician.
In addition to the compound, the compositions of the subject invention contain a pharmaceutically-acceptable carrier. The term "pharmaceutically-acceptable carrier", as used herein, means one or more compatible solid or liquid filler diluents or encapsulating substances which are suitable for administration to a subject. The term "compatible", as used herein, means that the components of the composition are capable of being commingled with the compound, and with each other, in a manner such that there is no interaction which would substantially reduce the pharmaceutical efficacy of the composition under ordinary use situations. Pharmaceutically-acceptable carriers must, of course, be of sufficiently high purity and sufficiently low toxicity to render them suitable for administration to the subject being treated.
Some examples of substances which can serve as pharmaceutically-acceptable carriers or components thereof are sugars, such as lactose, glucose and sucrose; starches, such as cornstarch and potato starch; cellulose and its derivatives, such as sodium carboxymethyl cellulose, ethyl cellulose, cellulose acetate; powdered tragacanth; malt; gelatin; talc; solid lubricants, such as stearic acid, magnesium stearate; calcium sulfate; vegetable oils, such as peanut oil, cottonseed oil, sesame oil, olive oil, corn oil and oil of theobroma; polyols such as propylene glycol, glycerin, sorbitol, mannitol, and polyethylene glycol; alginic acid; emulsifiers, such as the Tweens®; wetting agents such as sodium lauryl sulfate; coloring agents; flavoring agents, excipients; tableting agents; stabilizers; antioxidants; preservatives; pyrogen-free water; isotonic saline; and phosphate buffer solutions.
The choice of a pharmaceutically-acceptable carrier to be used in conjunction with a compound is basically determined by the way the compound is to be administered. The compounds of the present invention may be administered systemically. Routes of administration include transdermal; oral; parenterally, including subcutaneous or intravenous injection; topical; and/or intranasal.
The appropriate amount of the compound to be used may be determined by routine experimentation with animal models. Such models include, but are not limited to the intact and ovariectomized rat models, the ferret, canine, and non human primate models as well as disuse models.
Preferred unit dosage forms for injection include sterile solutions of water, physiological saline, or mixtures thereof. The pH of said solutions should be adjusted to about 7.4. Suitable carriers for injection or surgical implants include hydrogels, controlled- or sustained release devises, polylactic acid, and collagen matrices.
Suitable pharmaceutically-acceptable carriers for topical application include those suited for use in lotions, creams, gels and the like. If the compound is to be administered perorally, the preferred unit dosage form is tablets, capsules and the like. The pharmaceutically-acceptable carriers suitable for the preparation of unit dosage forms for oral administration are well-known in the art. Their selection will depend on secondary considerations like taste, cost, and shelf stability, which are not critical for the purposes of the subject invention, and can be made without difficulty by those skilled in the art.
Methods of Use
The compounds of the present invention are useful in treating many medical disorders, including for example, ocular disorders, hypertension, fertility control, nasal congestion, neurogenic bladder disorder, gastrointestinal disorders, dermatological disorders, and osteoporosis.
The compounds of the present invention are useful in increasing bone volume and trabecular number through formation of new trabeculae, increasing bone mass while maintaining a normalized bone turnover rate, and formation of bone at the endosteal surface without removing bone from the existing cortex. Thus, these compounds are useful in the treatment and prevention of bone disorders.
The preferred routes of administration for treating bone disorders are transdermal and intranasal. Other preferred routes of administration include rectal, sublingual, and oral.
The dosage range of the compound for systemic administration is from about 0.01 to about 1000 μg/kg body weight, preferably from about 0.1 to about 100 μg/kg per body weight, most preferably from about 1 to about 50 μg/kg body weight per day. The transdermal dosages will be designed to attain similar serum or plasma levels, based upon techniques known to those skilled in the art of pharmacokinetics and transdermal formulations. Plasma levels for systemic administration are expected to be in the range of 0.01 to 100 nanograms/ml, more preferably from 0.05 to 50 ng/ml, and most preferably from 0.1 to 10 ng/ml. While these dosages are based upon a daily administration rate, weekly or monthly accumulated dosages may also be used to calculate the clinical requirements.
Dosages may be varied based on the patient being treated, the condition being treated, the severity of the condition being treated, the route of administration, etc. to achieve the desired effect.
The compounds of the present invention are also useful in decreasing intraocular pressure. Thus, these compounds are useful in the treatment of glaucoma. The preferred route of administration for treating glaucoma is topically.
Composition and Method Examples
The following non-limiting examples illustrate the subject invention. The following composition and method examples do not limit the invention, but provide guidance to the skilled artisan to prepare and use the compounds, compositions and methods of the invention. In each case other compounds within the invention may be substituted for the example compound shown below with similar results. The skilled practitioner will appreciate that the examples provide guidance and may be varied based on the condition being treated and the patient.
Example A
Pharmaceutical compositions in the form of tablets are prepared by conventional methods, such as mixing and direct compaction, formulated as follows:
______________________________________Ingredient Quantity (mg per tablet)______________________________________Compound of Example 1 5Microcrystalline Cellulose 100Sodium Starch Glycollate 30Magnesium Stearate 3______________________________________
When administered orally once daily, the above composition substantially increases bone volume in a patient suffering from osteoporosis.
Example B
Pharmaceutical compositions in liquid form are prepared by conventional methods, formulated as follows:
______________________________________Ingredient Quantity______________________________________Compound of Example 1 5 mgPhosphate buffered physiological saline 10 mllMethyl Paraben 0.05 ml______________________________________
When 1.0 ml of the above composition is administered subcutaneously once daily, the above composition substantially increases bone volume in a patient suffering from osteoporosis.
Example C
Topical pharmaceutical compositions for lowering intraocular pressure are prepared by conventional methods and formulated as follows:
______________________________________Ingredient Amount (wt %)______________________________________Compound of Example 38 0.004Dextran 70 0.1Hydroxypropyl methylcellulose 0.3Sodium Chloride 0.77Potassium chloride 0.12Disodium EDTA (Edetate disodium) 0.05Benzalkonium chloride 0.01HCL and/or NaOH pH 7.2-7.5Purified water q.s. to 100%______________________________________
While particular embodiments of the subject invention have been described, it would be obvious to those skilled in the art that various changes and modifications to the compositions disclosed herein can be made without departing from the spirit and scope of the invention. It is intended to cover, in the appended claims, all such modifications that are within the scope of this invention. | The invention provides novel PGF analogs. In particular, the present invention relates to compounds having a structure according to the following formula: ##STR1## wherein R 1 , R 2 , R 3 , R 4 , X, Y, and Z are defined below. This invention also includes optical isomers, diastereomers and enantiomers of the formula above, and pharmaceutically-acceptable salts, biohydrolyzable amides, esters, and imides thereof.
The compounds of the present invention are useful for the treatment of a variety of diseases and conditions, such as bone disorders and glaucoma. Accordingly, the invention further provides pharmaceutical compositions comprising these compounds. The invention still further provides methods of treatment for bone disorders and glaucoma using theses compounds or the compositions containing them. | 2 |
BACKGROUND AND SUMMARY
[0001] Films for ostomy applications should have good odor barrier properties and produce minimal noise when flexed or wrinkled to avoid embarrassment to users. Typically, films currently in use for ostomy applications utilize polyvinylidene chloride (PVDC) or copolymers of vinylidene chloride with a comonomer such as methylacrylate or vinylchloride as the gas barrier layer of a multilayer film. Such multilayer films have good resistance to odor transmission and are also relatively quiet; however, they are also believed to be hazardous to the environment when disposed of by incineration, a common practice in numerous countries. Chlorinated polymers generate hydrochloric acid as a byproduct of incineration and are believed to be a significant contributor to hydrochloric acid release from incinerator flue gases. Furthermore, chlorinated polymers are believed to form toxic dioxin derivatives as byproducts of incineration which are retained in the ashes and may possibly cause solid waste disposal problems.
[0002] Unfortunately, films formed of chlorine-free barrier resins tend to be stiffer and noisier than films utilizing conventional PVDC-based resins and do not match the quality of conventional chlorinated films for use in ostomy appliances. Thus, a need exists for a multilayer film which is chlorine-free, can be manufactured by coextrusion from readily available raw materials, is heat sealable, has high softness and low noise when flexed or wrinkled, and is, impermeable to fecal odors.
[0003] U.S. Pat. No. 5,567,489 discloses a multilayer barrier film in which a chlorine-free barrier layer is composed of amorphous nylon, crystalline nylon, copolymers of ethylene and vinyl alcohol, or blends thereof. Although data presented in the patent indicate the multilayer films to be comparable in quietness to some chlorinated films in general commercial use, experience has revealed that such chlorine-free films are nevertheless significantly noisier than the chlorine-containing films commonly employed for the fabrication of ostomy pouches. The general observation is that chlorine-free barrier resins are high modulus, stiff materials that do not lend themselves to the production of low noise ostomy films. This is true of all nylon (polyamide) barrier resins, both crystalline and amorphous. It is true also of other known chlorine-free barrier resins such as hydrolyzed ethylene-vinylacetate copolymers, commonly known as ethylene-vinylalcohol copolymers, and copolymers of acrylonitrile or methacrylonitrile of high nitrile content, commonly known as nitrile resins.
[0004] Other references illustrating the current state of the art relating to chlorine-free multilayer films are U.S. Pat. Nos. 5,496,295, 5,643,375, 5,407,713, and 5,895,694.
[0005] An important aspect of this invention lies in the discovery that the noise properties of a multilayer film in which amorphous nylon (polyamide) is utilized for the odor barrier layer may be significantly reduced, without appreciably affecting the barrier properties, by blending the nylon with an anhydride-modified olefinic polymer or copolymer having a density of 0.89 g/cc or lower. The anhydride-modified olef polymer or copolymer should be present in the range of about 10% to 30%, preferably 15% to 25%, per total weight of the barrier layer.
[0006] The multilayer film includes at least one skin layer, preferably two such skin layers, consisting essentially of an ethylene polymer or copolymer, and an adhesive tie layer interposed between each skin layer and the blended amorphous nylon barrier layer. Each adhesive tie layer is primarily composed of an anhydride-modified ethylenic polymer, such as polyethylene or copolymer of ethylene and vinylacetate, containing anhydride groups capable of promoting interfacial adhesion with the polyamide-containing barrier layer.
[0007] The result is a heat-sealable multilayer film that is particularly useful for ostomy appliances because of its exceptional odor barrier properties while at the same time being relatively soft (low modulus) and quiet in relation to known chlorine-free films in which the odor barrier layer is formed entirely of nylon, ethylene-vinylalcohol copolymers, or nitrile resins. With regard to the generation of noise upon flexing, the chlorine-free multilayer films of this invention compare favorably with prior art ostomy films having chlorinated barrier layers. A pouch formed of the multilayer film of this invention therefore has properties comparable to those exhibited by high-quality pouches formed of chlorine-containing compositions but without the environmental shortcomings described above.
[0008] Other features, advantages and objects of the invention will become apparent from the specification and drawings.
DRAWINGS
[0009] [0009]FIG. 1 is a schematic cross-sectional view of an embodiment of the multilayer barrier film of this invention.
[0010] [0010]FIG. 2 is an elevational view of an ostomy pouch formed from the multilayer barrier film of FIG. 1.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0011] The multilayer chlorine-free film of the present invention may be produced using standard coextrusion techniques involving either casting or blowing. Preferably, the multilayer film has five layers—a chlorine-free barrier layer sandwiched between two heat-sealable skin layers with tie layers interposed between the skin and barrier layers—but the advantages of the invention may be at least partially achieved in a three-layer structure having a barrier layer and single skin and tie layers.
[0012] [0012]FIG. 1 schematically illustrates a multilayer chlorine-free film 10 having an odor barrier layer 11 sandwiched between tie layers 12 and 13 and skin layers 14 and 15 . The chlorine-free barrier layer 11 is essentially composed of a blend of amorphous polyamide (nylon) resin and an anhydride-modified olefinic polymer or copolymer. Unlike crystalline polyamides which are entirely aliphatic, amorphous polyamides have a partially aromatic structure and are typically produced by the condensation of an aliphatic diamine with an aromatic diacid, or combination of diacids, in molar amounts equivalent to the diamine used. While it is believed that any amorphous polyamide resin may be used, effective results have been obtained with a polyamide resin marketed as Selar PA3426 by Dupont Company. Selar PA3426 is understood to be substantially amorphous with a density of about 1.19 grams per cubic centimeter (g/cc). It has high melt strength and can be used under a broader range of processing conditions than conventional crystalline nylons. Selar PA3426 5s produced by the condensation of hexamethylenediamine, terephthalic acid, and isophthalic acid such that 65% to 80% of the polymer units are derived from hexamethylene isophthalamide. For further information, reference may be had to 52 Fed. Req. 26,667 (1987), the disclosure of which is incorporated by reference herein.
[0013] The amorphous polyamide resin is the major constituent of the blend, comprising about 70% to 90% by weight of that blend. The anhydride-modified olefinic polymer or copolymer comprises about 10% to 30%, preferably 15% to 25% of the total weight of the barrier layer. The density of the anhydride modified olefinic polymer should be less than 0.89 g/cc, preferably less than 0.87 g/cc. Anhydride-modified olefinic polymers with densities higher than 0.89 g/cc might still be effective as toughening agents but would not provide the reduction in film modulus and noise imparted by lower density polymers. The olefinic polymer or copolymers are functionalized by reactive processing with an unsaturated carboxylic anhydride. Although the mechanism of anhydride modification is not fully understood, it is believed that a grafting reaction occurs between the polymer and the unsaturated anhydride. While it is believed that other unsaturated carboxylic anhydrides may be used to provide the functional groups, maleic anhydride is considered particularly effective for that purpose. The level of maleic anhydride needed to functionalize the olefinic polymer is quite low, less than 2% by weight. The density of the olefinic polymer is essentially unaffected by anhydride modification at these low levels. One example of an anhydride-modified olefinic copolymer is Fusabond MN493D available from DuPont ccrpany. Fusab.cd MN493D is an ethylene oatene c-Folymer that is modified with 0.5% maleic anhydride and has a density of 0.869 g/cc. While it is known to function as a toughening agent for crystalline nylon, rusabond MN493D performs an unexpected function here in decreasing modulus and noise of amorphous nylon without destroying or significantly reducing the odor barrier properties of layer 11 . Similar performance can be achieved with other anhydride-modified olefinic polymers having comparable low density, such as ethylene-propylene copolymers and terpolymers (EPM and EPDM). EPM and EPDM have a density in the 0.85 to 0.86 g/cc range and are suitable for modification with maleic anhydride. Due to the immiscible nature of these blends, mixing of the nylon with the anhydride-modified olefinic polymer is best conducted in a separate step using a twin screw compounder extruder with either corotating or counterrotating screws. This allows an intimate dispersion of the olefinic phase into the nylon phase. The compounded blend is extruded and cut into pellets which can then be used for extrusion into film.
[0014] Skin layers 14 and 15 are formed of an ethylene-based polymer or copolymer with an alpha-olefin such as hexene or octene. A suitable resin is metellocene-catalyzed polyethylene with an octene comonomer such as the ethylene octene copolymer marketed under the designation Exact 8201 by Exxon Chemical.
[0015] Tie layers 12 and 13 must be capable of bonding to both the skin layers and the core barrier layer. Polyethylene, ethylene vinyl acetate copolymers (EVA), or ethylene methyl acrylate copolymers (EKA), modified with functional anhydride groups are believed particularly suitable. EVA-based anhydride-modified resins such as Bynel 3860 or Bynel 3861, or polyethylene-based ahydride-modified resins such as Bynel 4lE557, all available from DuPont company, have been found suitable. The ability of these anhydride-modified resins to act as adhesion promoters is believed to be due to an interfacial reaction between the anhydride groups in the tie layer and the amine groups of nylon in the barrier layer.
[0016] The total thickness of the multilayer film, assuming five layers are present, should fall within the general range of about 2 to 5 mil, preferably about 3 to 4 mil. As to the barrier layer 11 , its thickness should fall generally within the range of 0.1 to 1.0 mil with the lower limit being established by the capability of the extrusion process and the upper limit by the physical properties contributed by the barrier layer in achieving a multilayer film having low modulus and low noise characteristics. Preferably, the barrier layer thickness should fall within the range of about 0.2 to 0.4 mil, with 0.3 mil being considered optimal when factors such as odor barrier properties, softness, quietness, and ease of extrusion are all considered together. By contrast, the skin layers 14 and 15 are each considerably thicker than the barrier layer sandwiched between them. For example, each skin layer may have a thickness within the general range of about 0.5 to 2.5 mil, preferably 1 to 2 mil, which may be nearly one order of magnitude greater than the thickness of the odor barrier layer 11 .
[0017] [0017]FIG. 2 illustrates a typical ostomy pouch 16 having its walls 16 a and 16 b formed from the multilayer film of FIG. 1. The films are arranged with their heat sealable skin layers facing each other and sealed together along the outer periphery of the pouch as indicated at 17 . One wall of the pouch has a stoma-receiving opening 18 formed therein and an adhesive attachment ring 19 is located about that opening for adhesive attachment to the peristomal skin surfaces of a patient. The pouch as shown is of the type generally referred to as a one-piece appliance but, if desired, a mechanical coupling ring may be substituted for adhesive ring 19 , with the pouch therefore becoming one component of a two-piece ostomy appliance, all as well known in the art.
[0018] In order that the invention may be more readily understood, reference is made to the following examples which are intended to be illustrative of the invention, but are not intended to be limiting in scope.
EXAMPLE 1
[0019] This example illustrates the properties of blends of amorphous nylon (Selar PA3426, DuPont Company) with anhydride-modified polyolefin (Fusabond MN493D, DuPont Company). The two resins were compounded and pelletized using a twin screw compounder extruder. The compounded resins were then coextruded using a Killion extruder into a A/B/A three-layer film structure, wherein A was polyethylene and B was the nylon blend. Because of the absence of tie layers, it was possible to strip the polyethylene skin layers A from the nylon blend layer B and to test the resulting monolayer B films against a monolayer film consisting of 100% amorphous nylon (Selar PA3426). Secant modulus at 2% elongation of the monolayer films was measured in the machine and transverse directions according to ASTM D882 at a strain rate of 0.1 in./in.min. Results are shown below in Table 1:
TABLE 1 Monolayer Film Composition Secant Modulus Selar PA3426 Fusabond MN493D psi % % MD TD 100 0 323,500 312,600 85 15 235,600 215,000 75 25 190,000 120,000
[0020] The data in Table 1 shows the reduction in modulus resulting from the addition of Fusabond MN493D to Selar PA3426. The lower modulus values indicate that the compounded resins are considerably softer than the control resin with 100% amorphous nylon. The reduction in modulus allows the production of nylon-based multilayer films which are soft and quiet, as indicated in further examples below.
EXAMPLE 2
[0021] A five-layer film was produced in accordance with this invention by coextrusion casting, resulting in a film with a total thickness of 3.3 mil and a barrier layer thickness of 0.32 mil. The film structure was A/B/C/B/A, where A was a polyethylene-based resin (Exact 8201, Exxon Chemical Co.) modified by the addition of 5% of a slip/antiblock concentrate (EXT4226TSE, A. Schulman Co.) and 3% of a low-density polyethylene (LD200.48, Exxon Chemical Co.). B are tie layers consisting of anhydride-modified ethylene vinyl acetate copolymer (Bynel 3601, DuPont Co.), and C is a blend of amorphous nylon (Selar PA3426) with an anhydride-modified rubbery polyolefin (Fusabond MN493D) at 85% to 15% weight ratio.
[0022] The film was tested for quietness by forming a 4 inch by 4 inch sample into a cylinder and mounting it on a test fixture wherein one end of the cylinder was held fixed and the other was rotated around the cylinder axis at an angle of 15 degrees at 70 cycles per minute. Noise emissions produced by the film's flexing were analyzed with a sound level meter. For comparison, the same test was conducted on a commercial ostomy film with a chlorinated barrier. Results are shown below;
TABLE 2 Sample dBA dB, 8 kHz dB, 16 kHz Film of Example 2 64 49 39 Control Film 74 55 49
[0023] In this table, dBA is a weighted average that takes into account the human perception of noise over the entire frequency range, whereas B values in the 8 and 16 kHz octave bands are indicative of the noise in the higher frequency range and represent the crispness of the noise. The dBA and dB values therefore reveal that the film sample embodying the invention is considerably quieter than the control sample in which the core layer is based on PVDC.
EXAMPLE 3
[0024] A five-layer film was produced in accordance with this invention by coextrusion casting, resulting in a film with a total thickness of 3.2 mil and a barrier layer thickness of 0.28 mil. The film construction was A/B/C/B/A, having the same composition as the film of Example 2 except that the tie layers B were polyethylene-based (Bynel 41E557,DuPont Co.). The film was tested for quietness as described in Example 2. Results are shown in the table below which includes a control sample of a commercial ostomy film having a chlorinated barrier layer of PVDC.
TABLE 3 Sample dBA dB, 8 kHz dB, 16 kHz Film of Example 3 65 51 45 Control Film 74 55 49
[0025] As in Example 2, the dBA and dB values at 8 and 16 kHz reveal that the film sample of Example 3 is considerably quieter than the control sample in which the core layer is PVDC.
EXAMPLE 4
[0026] The films of Examples 2 and 3 were tested for odor transmission using British Standard 7127, Part 101, Appendix G: Method for Determining Odour Transmission of Colostomy and Ileostomy Bag Materials, British Standard Institution, London. Both films passed the test, indicating that the modification of the nylon barrier layer does not have a detrimental effect on odor barrier properties of the films.
[0027] In addition, a quantitative test of the barrier properties of the film of Example 2 was conducted using three model compounds for fecal odor: dimethyldisulfide, indole, and skatole. For comparison, the same test was conducted on a commercial ostomy film with a chlorinated (PVDC) barrier layer. Analysis of effluent gases was conducted by gas chromatography using a flame ionization detector. Table 4 shows breakthrough times and concentration of each component in the effluent stream after 60 hours.
TABLE 4 Breakthrough Concentration at Times, min 60 hours Dimethyl Dimethyl disulfide Indole Skatole disulfide Indole Skatole Film min min min ppm ppb ppb Film of 2680 1880 2180 25 102 51 Example 2 Control 722 1140 1610 137 292 91 Film
[0028] Better barrier properties are expected for films that show longer breakthrough times and lower effluent concentration. The film of Example 2 is superior to the chlorinated control film in both respects, indicating superior performance as a barrier to fecal odorants.
[0029] While in the foregoing, embodiments of the invention have been disclosed in detail for purposes of illustration, it will be understood by those skilled in the art that many of these details may be varied without departing from the spirit and scope of the invention. | A multilayer heat-sealable chlorine-free odor barrier film having relatively low modulus, high interlaminar strength, and low noise upon flexing is provided. The film comprises an odor barrier layer of an amorphous polyamide resin blended with an anhydride-modified olefinic polymer or copolymer. The film also includes at least one heat-sealable skin layer, preferably two such skin layers on opposite sides of said odor barrier layer, composed of an ethylene polymer or copolymer, and an adhesive tie layer between each skin layer and the odor barrier layer. Pouches formed of such multilayer films are also disclosed. | 1 |
CROSS-REFERENCE TO RELATED APPLICATION
This is a continuation-in-part of my copending application Ser. No. 113,896, filed Jan. 21, 1980 which is a continuation-in-part of my copending application Ser. No. 053,672, filed July 2, 1979 both now abandoned.
BACKGROUND OF THE INVENTION
The invention relates to new chemical compounds and particularly to derivatives of aromatic dicarbonyl compounds. These derivatives, more specifically are tetracarboxylic acid derivatives of aromatic dicarbonyl compounds and exhibit utility as synthetic resin intermediates.
DESCRIPTION OF THE PRIOR ART
U.S. Pat. Nos. 3,293,278 and 3,355,464 teach certain derivatives of diphenylethylbenzene, specifically derivatives of the formula ##STR2## wherein Z is a divalent moiety including ##STR3##
V. V. Perekalin et al. in J. Gen. Chem. USSR, Eng. Ed., 28, 1861 (1958) disclosed the synthesis of certain bis(nitroalkyl)benzene compounds and their derivatives. Included were compounds of the formula ##STR4## Hedge and coworkers in J. Org. Chem. 26, 3167 (1961) reported that the condensation of a dicarbonyl compound with a very active methylene compound did not produce the 1:4 condensate, but rather only the 1:3 condensate. Thus, when isophthaldehyde and terephthaldehyde were contacted with excess isopropylidinyl malonate in dimethylformamide the product in either case resulted from both an aldol reaction and a Michael reaction at one aldehyde functionality but only an aldol reaction at the remaining aldehyde functionality.
SUMMARY OF THE INVENTION
The invention comprises certain tetracarboxylic acid compounds of the formula ##STR5## wherein Ar is a C 6-20 arylene radical selected from the group consisting of: ##STR6## wherein w in each occurrence is halo, nitro, or a C 1-10 radical selected from alkyl, aryl, alkaryl, aralkyl, haloalkyl, haloaryl, aryloxy and alkoxy; q is an integer from zero to 4; and w' is oxygen, sulfur, alkylene, oxyalkylene, alkylenedioxy or polyoxyalkylene; R 1 , R 2 individually are hydrogen or alkyl, aryl, aralkyl, or alkaryl radicals containing up to 10 carbon atoms, and both n's are zeros or ones. Also included in the invention is a novel process for producing compounds of formula I wherein both n's are 1. The compounds are useful as precursors in the manufacture of polymeric substances. In particular the compounds may be readily converted to stable dianhydrides having 5 or 6 members in each anhydride ring, which thereafter may be reacted with diamine-containing compounds to form unique polyimide compounds which possess improved physical properties at elevated temperatures.
DETAILED DESCRIPTION OF THE INVENTION
The compounds of formula (I) wherein n is zero are prepared by an initial Knovenagel condensation of an alkyl cyanoacetate and an aromatic dicarbonyl compound, either an aromatic dialdehyde or an aromatic diketone. The aromatic diketone may be symmetrical or unsymmetrical. Suitable alkyl cyanoacetate reactants are methyl cyanoacetate, ethyl cyanoacetate, propyl cyanoacetate, butyl cyanoacetate, pentyl cyanoacetate, hexyl cyanoacetate, heptyl cyanoacetate, octyl cyanoacetate, nonyl cyanoacetate, and decyl cyanoacetate. A preferred alkyl cyanoacetate reactant is ethyl cyanoacetate.
Suitable aromatic dicarbonyl compounds are all compounds of the formula ##STR7## wherein R 1 , R 2 and Ar are as previously defined.
Preferred aromatic dicarbonyl compounds are dialdehyde and diketone derivatives of benzene. Most preferred aromatic dicarbonyl compounds are terephthaldehyde, isophthaldehyde, and p-diacetylbenzene.
The condensation takes place as is known in an inert organic solvent in the presence of a basic catalyst, for example, ethylenediamine, pyridine, piperidine or a buffered catalyst system composed of an amine and the corresponding conjugate acid. Suitable solvents include anhydrous alcohols, e.g., methanol, ethanol, etc. The reaction proceeds smoothly at atmospheric pressure, however, reduced or elevated pressures may also be employed if desired. The condensation may be allowed to proceed at ambient temperature for a sufficient amount of time to produce a precipitate, illustratively about one hour or more. Reaction vessels of ordinary design and construction, e.g., glass flasks may conveniently be used. The product is recovered by filtration or decanting of liquid and may be recrystallized as for example from toluene, benzene or acetone.
The next step of the synthesis is to form the bis-dicyanoester. This may be done in two steps by reacting the bis(2-carbalkoxy-2-cyanoethenyl)arene produced in the initial Knovenagel condensation with an alkali metal cyanide followed by acidification. Alternatively one may contact HCN directly with the bis(2-carbalkoxy-2-cyanoethenyl)arene, as for example by contacting gaseous HCN with the dicyano compound in an inert liquid medium. Again ordinary reaction equipment and parameters may be employed, exercising caution of course when handling the dangerous cyanide reactants.
The bis[(alkoxycarbonyl)dicyanoalkyl]arene compounds are easily recovered as they precipitate from the acidic solution. They may be washed and purified, for example by recrystallization from alcoholic solvents.
Next the bis[(alkoxycarbonyl) dicyanoalkyl]arene compound is subjected to acid hydrolysis. It is not necessary that the bis-dicyano compound be first purified before being subjected to acid hydrolysis, although a recovery and purification step may be employed, if so desired. Preferably, excess concentrated hydrochloric or sulfuric acid is added to the same reaction vessel after the solvent from the above acidification step has been decanted, and the mixture is then refluxed. Because foaming is likely to occur, a defoaming agent should preferably be added to the mixture during the hydrolysis step. I have found a small amount of glacial acetic acid to act as an effective defoaming agent.
Refluxing is continued for several hours, up to ten hours or more. As the reaction progresses, the aromatic bis(dicarboxylic)acid forms and precipitates from solution. The precipitated products are easily recovered, for example, by chilling the solution and then filtering. The compounds may be washed with ice water to remove residual acid and dried under vacuum. Purification by recrystallization may conveniently be accomplished using water as a solvent.
The aromatic tetracarboxylic acid may be used among other utilities as an epoxy curing agent and in the preparation of synthetic resins.
The compounds of formula (I) wherein n is 1 are prepared by an initial Knovenagel condensation of four equivalents of cyanoacetic acid with an aromatic dicarbonyl compound, either an aromatic dialdehyde or an aromatic diketone. The aromatic diketone may be symmetrical or unsymmetrical.
Suitable aromatic dicarbonyl compounds are those compounds previously mentioned. A preferred dicarbonyl compound is terephthaldehyde.
The reactants are combined in at least a 4:1 mole ratio of cyanoacetic acid and aromatic dicarbonyl compound. Preferably, a stoichiometric excess of cyanoacetic acid is present, e.g., the reactants are combined in a mole ratio greater than 4:1.
The condensation takes place in pyridine solvent, preferably in the presence of a catalyst, for example, piperidine. The condensation takes place at an elevated temperature. Preferable are temperatures from about 80° to 200° C., most preferably, from 100° to 150° C. The reaction proceeds smoothly at atmospheric pressure, however, reduced or elevated pressures may also be employed if desired. Reaction times of from several hours to 20 hours or more may be employed. Reaction vessels of ordinary design and construction, e.g., glass flasks may conveniently be used. The resulting product may be recovered by ordinary techniques, for example, by solvent evaporation under reduced pressure, and may be recrystallized if desired.
Next the tetra cyano derivative is hydrolyzed to the tetraacid by refluxing in concentrated acid. It is not necessary that the tetra cyano compound be first purified before being subjected to acid hydrolysis, although a purification step, for example, recrystallization, may be employed if so desired. The acid employed may be concentrated sulfuric or concentrated hydrochloric acid. Because foaming is again likely to occur, a defoaming agent such as glacial acetic acid should preferably be employed.
The reaction conditions and recovery techniques employed are those described previously for the hydrolysis step in producing compounds of formula (I) wherein n is zero.
The tetra acid compound obtained may be recrystallized if desired, although the crude reaction product is generally obtained in sufficiently pure form for further use without a recrystallization step. A suitable solvent for use in recrystallization is a mixture of acetonitrile and dimethylsulfoxide.
SPECIFIC EMBODIMENTS OF THE INVENTION
Having described my invention the following examples are provided as further illustrative of my present invention and are not to be construed as limiting.
EXAMPLE 1 - 1,4-bis(1,2-dicarboxyethyl)benzene
A quantity of 1,4-bis(2-carbethoxy-2-cyanoethenyl)benzene was prepared according to the method of Perekalin and Lerner. Accordingly, a drop of piperidine was added to quantities to ethyl cyanoacetate and terephthaldehyde in an excess of anhydrous ethanol accompanied by stirring at ambient temperature. A clear solution slowly formed yielding a crystalline condensation product upon further reaction. After 10 hours the condensation was terminated, the precipitate collected by filtration, and washed with methanol. The product, in the form of yellowish-green needles was soluble in hot benzene and acetone but insoluble in ethanol.
Next, 32.4 g (0.1 mole) of this diester was stirred with sodium cyanide (19.6 g, 0.4 mole) in 400 ml of 50 percent aqueous ethanol at ambient temperature, in a 1-liter glass flask. After 1.5 hours the solution was acidified by adding excess concentrated HCl. The product, 1,4-bis(2-carbethoxy-1,2-dicyanoethyl)benzene was deposited as a yellow oil which solidified upon standing.
Next, 200 ml of concentrated hydrochloric acid was added to the decanted reaction flask. Approximately 10 ml of glacial acetic acid was added to inhibit foaming and the mixture was refluxed for 10 hours. A white precipitate gradually formed and separated from the mixture. Refluxing was discontinued and the flask and contents chilled in ice. Filtration followed by washing with ice water and oven drying in vacuo gave 30.1 g (97 percent yield) of 1,4-bis(1,2-dicarboxyethyl)benzene.
To identify the product a small sample was recrystallized from water. Analysis by standard analytical techniques gave the following results:
______________________________________ % C % H melting point °C.______________________________________calculated 54.2 4.52 --found 54.2 4.49 228-230.5______________________________________
Analysis by nuclear magnetic resonance (NMR) and infrared absorption (IR) spectroscopy also confirmed the product's identity as 1,4-bis(1,2-dicarboxyethyl)benzene.
EXAMPLE 2 - 1,3-bis(1,2-dicarboxyethyl)benzene
A mixture of isophthaldehyde (2.68 g, 0.02 mole), ethyl cyanoacetate (4.6 g, 0.04 mole), piperidine (2 drops) and anhydrous methanol (50 ml) was stirred at room temperature for 5.5 hours. A white precipitate (5.5 g, 85 percent yield) was collected and identified as 1,3-bis(2-carbethoxy-2-cyanoethenyl)benzene.
The above-prepared product (5.1 g, 0.015 mole) was suspended in 75 ml water. Sodium cyanide (2.36 g, 0.048 mole) was added with stirring at ambient temperature. After 2 hours the clear solution was acidified and the product extracted with methylene chloride. This fraction was washed with water, dried with anhydrous MgSO 4 and then evaporated to dryness yielding 5.1 g of a waxy white solid. Analysis by IR and NMR spectroscopy confirmed the product's identity as 1,3-bis(2-carbethoxy-1,2-dicyanoethyl)benzene.
The product was then hydrolyzed according to the same procedure employed in Example 1. The resulting product, 1,3-bis(1,2-dicarboxyethyl)benzene, was identified by IR and NMR spectroscopy.
EXAMPLE 3 - 1,4-bis(1,2-dicarboxy-1-methylethyl)benzene
A mixture of p-diacetylbenzene (20.25 g, 0.125 mole), ethyl cyanoacetate (28.3 g, 0.25 mole), ammonium acetate (3.85 g) and acetic acid (10 g) was combined in a 500 ml glass round-bottom flask with toluene (150 ml) and refluxed for 12 hours. A Dean-Stark trap was employed to trap water formed during the reaction. Refluxing was discontinued and the solvent evaporated. The residue containing crude product was distilled under reduced pressure. One fraction, boiling point range 177° C.-195° C. (0.6 mm) amounting to 20.6 g was identified as predominately the 1:1 condensation product. A second fraction, boiling point ˜200° C. yielded 18.2 g of 1,4-bis(2-carbethoxy-2-cyano-1-methylethenyl)benzene.
A portion of this second product weighing 9.29 g was heated at 85° C. for 2 hours in 50 ml water having dissolved therein sodium cyanide (5.12 g). After heating, the solution was stirred for 3 hours at room temperature. The diester slowly dissolved resulting in a clear light yellow solution. The solution was then acidified with excess concentrated HCl and the product extracted with chloroform. The product, 1,4-bis(2-carbethoxy-1,2-dicyano-1-methylethyl)benzene was identified by IR and NMR spectroscopy.
The product was then hydrolyzed by refluxing according to the procedure of Example 1 above. The product, 1,4-bis(1,2-dicarboxy-1-methylethyl)benzene, was identified by IR and NMR spectroscopy.
EXAMPLE 4 - 1,4-bis-2-(1,3-dicarboxy)propyl benzene
Terephthaldehyde (53.6 g, 0.4 mole) and cyanoacetic acid (170 g, 2 moles) were combined in a round bottom flask with 350 ml of pyridine containing 20 ml piperidine. The mixture was then refluxed for about 15 hours. A yellow solution remained when refluxing ceased. After the solvent was removed by evaporation under reduced pressure a residue remained. This residue was washed with aqueous HCl followed by methanol and the product dried leaving 84.5 g (80.6% yield) of 1,4-bis-2-(1,3-dicyano)propyl benzene.
A portion of the product was hydrolyzed by adding the tetracyano compound to 200 ml concentrated HCl having added thereto 50 ml glacial acetic acid to inhibit foaming in a glass round bottom flask. Heating was commenced and the mixture refluxed for about 9 hours.
The product obtained upon chilling and filtration of the acid solution followed by washing with ice water had a melting point range of 256°-258° C. Yield was 68 g or 100 percent.
An analytic sample was recrystallized from acetonitrile-dimethyl sulfoxide solution. The recrystallized product had the following analysis:
______________________________________ % C % H melting point °C.______________________________________calculated 56.8 5.33 --found 57.0 5.38 257-259______________________________________
Analysis by IR and NMR spectroscopy confirmed the product's identity as 1,4-bis-2-(1,3-dicarboxy)propylbenzene.
EXAMPLE 5 - 1,3-bis[4-(1,2-dicarboxyethyl)phenoxy]propane
The aldehyde, 1,3-bis(4-formylphenoxy)propane, was prepared by refluxing p-hydroxybenzaldehyde and 1,3-dibromopropane in an aqueous caustic solution. The recovered and recrystallized product (14.2 g, 0.05 mole) was combined with ethyl cyanoacetate (11.3 g, 0.1 mole) in methanol (100 ml) and about 1.0 ml of piperidine catalyst added. The mixture was stirred at room temperature for 24 hours resulting in the formation of white, solid precipitate.
Recovery by filtration and washing with methanol gave 21.1 g (89 percent yield) of the desired product, 1,3-bis[4-(2-carbethoxy-2-cyanoethenyl)phenoxy]propane. The structure was confirmed by NMR and IR analysis.
The desired tetracyanide derivative was formed by adding 100 ml of 2 molar aqueous NaCN to a mixture of the above compound (46.0 g, 0.097 mole), triethylamine (7 g) and ethanol (70 ml). The resulting mixture was stirred for 11/3 hours at 50° C. until the solid biscyanoethenyl ester had dissolved. Upon acidification the desired product separated and was recovered.
This solid was added to 250 ml of concentrated HCl and the mixture refluxed for about 10 hours to effect hydrolysis and decarboxylation. The desired tetracarboxylic acid was isolated by filtration after cooling in an ice bath. Yield was 22.0 g (49 percent).
The product was a tan colored solid. A sample recrystallized from water melted at 221° C.-223° C. Analysis by NMR and IR confirmed the product's identity as 1,3-bis-[4-(1,2-dicarboxyethyl)phenoxy]propane.
EXAMPLE 6 - Polyimide Polymer Formation
A quantity of the product of Example 1, 1,4-bis(1,2-dicarboxyethyl)benzene was converted to the corresponding dianhydride, 1,4-bis(tetrahydrofuran-2,5-dion-3-yl)benzene by refluxing in acetic anhydride solvent for about 2 hours. The acetic anhydride was evaporated under reduced pressure and the residue collected. Recrystallization from methylethylketone gave the dianhydride which was characterized by infrared and nuclear magnetic resonance spectroscopy.
The polyimide was next produced by reacting a small quantity of 1,4-bis(tetrahydrofuran-2,5-dion-3-yl)benzene (2.74 g, 0.01 mole) with 4,4'-oxydianiline (2.0 g, 0.01 mole) in a mixture of 27 ml of m-cresol and 8 ml of toluene in a glass flask. Approximately 1 ml of triisopentylamine catalyst was added and the reaction mixture heated to about 180° C. After about 2 hours a completely homogenous mixture resulted.
The polyimide was isolated by precipitating in acetone. A white, fibrous polyimide-containing polymer was recovered (4.1 g, 94 percent yield). The inherent viscosity as measured in N-methylpyrrolidinone (25° C., 0.5 g/dl) was 0.69. The glass transition temperature as determined by differential scanning calorimetry was determined to be 275° C. | Novel tetracarboxylic acids are described of the formula ##STR1## wherein Ar, R 1 and R 2 are named substituents, and both n's are zeros or ones. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of prior Ser. No. 11/273,195, filed Nov. 14, 2005, entitled “Heat Exchange System”, by the same inventors.
BACKGROUND OF THE INVENTION
[0002] A. Field of the Invention
[0003] This invention relates in general to heat exchange systems and, in particular, to an instantaneous steam fired water heater system.
[0004] B. Description of the Prior Art
[0005] Water heaters are used in a large variety of residential, commercial and industrial settings. For example, large storage tank systems are often found in hospitals and institutions, industrial plants, schools, universities, apartment complexes, and the like. The different types of water heaters which are used to supply hot water to these systems may use various sources of energy, such as gas, oil, electricity or steam. For example, in conventional gas/oil fired water heaters, hot gas flows through a series of vertically mounted tubes which are mounted in vertical fashion between top and bottom support plates within the water heater tank. Water flows into and out of a chamber located between the support plates and contacts and circulates about the exterior of the vertical tubes to effect heat transfer to heat the water.
[0006] U.S. Pat. No. 4,465,024, issued Aug. 14, 1984, and assigned to the assignee of the present invention describes another type of water heater which has a submerged, pressurized combustion chamber so that all combustion occurs in the water heater tank interior in a chamber surrounded by water, thereby reducing heat loss and increasing efficiency. These two examples are merely intended to be illustrative of the various types of gas/oil fired water heaters which exist in the prior art.
[0007] In some of the end applications mentioned above, such as, for example, in a municipal apartment complex or an industrial process, it may be more convenient and economical to utilize an existing source of steam or other hot fluid as the energy source for heating the water, rather than using gas or oil. There are a large number of prior art patents on devices in which liquids have been heated by fluids such as steam or other hot liquids. One of the common apparatus designs is the so called “shell-and-tube” heat exchanger. In conventional shell-and-tube heat exchangers, the tube section of the heat exchanger consists of a bundle of tubes which are open at both ends. At each end, the tubes extend through and are welded to a tube sheet. The shell of the heat exchanger completely encloses the bundle. The tubes within the bundle are spaced apart from each other, and from the shell, to define the shell-side section of the heat exchanger. In a typical heat exchanging operation, one of the fluids (liquid or gas) is passed through the tube section of the heat exchanger. The other fluid is then passed through the shell section, that is, on the outside of the tubes, often in a flow path which is countercurrent to the fluid flowing through the tube section.
[0008] Because the demand for hot water tends to vary over time in most installations, it is generally necessary to provide some sort of control over the heat source or flow rate through the device to accommodate the varying flow rates of the water being heated. In most applications the temperature of the water to be heated varies dramatically according to the time of year, and other factors. For example, a typical domestic hot water system is only under demand about 10-20% of the time. Additionally, in most applications the quantity of water flowing through the heat exchanger varies according to the time of day and use patterns of the application. Thus, the heat exchanger outlet water temperature must be regulated in order to accommodate variability resulting from the inlet water temperature and flow rate changes.
[0009] In the case of hot water storage systems utilizing bulk storage tanks, one type of existing control system is commonly referred to as the “feedback-type” system. These systems operate by sensing the temperature of the water in the storage tank, using a temperature sensing device in the tank to feed back instructions to a steam control valve. Because they respond to what has already happened, feedback systems are by their very nature reactive, i.e., they are a step behind demand. Thus, although they can supply a large volume of water, bulky tank systems are slow to react and waste energy to heat unused water. They also tend to require a large amount of floor space to accommodate the storage tank. Maintaining a leaking tank is expensive and replacement often involves tearing out walls of the surrounding structure.
[0010] A shell-and-tube heat exchanger of the appropriate design in an instantaneous feedback system can eliminate the need for a bulky hot water storage tank which can be subject to leaking and corrosion and can also eliminate the response time problem discussed above. In fact, tankless instantaneous feedback systems, i.e., a shell-and-tube heat exchanger with a temperature regulator, are known in the prior art. However, the typical tankless instantaneous feed back system of the prior art have generally attempted to control outlet water temperature by controlling steam flow through the heat exchanger. Because of the inherent thermal lag in this type control process, outlet water temperatures can vary greatly when faced with wide swings in inlet water temperature and flow. These swings can exceed 50% of the difference between the cold water temperature and the desired hot water temperature when flow through the water heater changes quickly from full water flow capability to zero flow and back to full flow.
[0011] Thus, despite the improvement in the art generally in the area of heat exchangers and water heaters of the above type, a need continues to exist for an improved instantaneous water heater design which utilizes steam from a local boiler or district plant to provide energy to heat water to a desired temperature for a variety of hot water end use applications and which solves the problems of thermal lag discussed above.
[0012] A need also exists for such a heat exchange system which provides redundancy in the case of failure of a major component of the system.
[0013] A need also exists for such a heat exchange system which provides adequate safety features to prevent any danger of scalding should a valve or other component of the system fail.
SUMMARY OF THE INVENTION
[0014] Accordingly, it is an object of the invention to provide an improved shell-and-tube steam fired instantaneous heat exchange system of a closely coupled feedback design which overheats water in the heat exchanger and then blends the water, as needed, with proportional amounts of cold water to achieve the correct outlet temperature for a wide range of flow rates.
[0015] Another object is to provide such a system which acts immediately upon a change of demand so that there is virtually no time lag, providing all the hot water which is needed instantly, up to the unit's capacity.
[0016] Another object of the invention is to provide such a system which has built-in redundancy in case a major component of the system were to fail in use.
[0017] Another object is to provide such an improved water heating system which incorporates appropriate safety features to reduce the risk of scalding should a valve or other component of the system fail.
[0018] Another object is to provide such a system which occupies relatively little floor space and which does not require tearing out walls for installation, repair or replacement.
[0019] Another object is to provide such an improved system which does not waste energy by constantly reheating stored water.
[0020] These and additional objects of the invention are realized by the improved heat exchange system of the invention which includes a first process shell-and-tube heat exchanger having a cold water inlet and at least a second process shell-and-tube heat exchanger also having a cold water inlet. The second process heat exchanger is mounted in a water circulating circuit in parallel fashion with the first process heat exchanger to provide redundancy in case of the failure of either of the first and second heat exchangers. A steam source continuously supplies steam to a selected one of a shell and a tube side of the first and second shell-and-tube heat exchangers. A steam trap is associated with each of the first and second heat exchangers for collecting steam condensate, each of the steam traps having a closed position and an open position for discharging condensate. The discharge of condensate serves to allow more steam to enter the respective heat exchanger to provide additional heat for transfer to the water being heated.
[0021] Each of the first and at least second heat exchangers also has associated therewith a first and a second water tempering valve mounted in series. Each water tempering valve has a cold inlet port and a hot inlet port and a blended water outlet. Water from the blended outlet of the first water tempering valve is directed to the hot inlet port of the second water tempering valve, the first water tempering valve acting to blend cold water and hot water to a predetermined temperature set point which is above a set point of the second water tempering valve, to thereby bias the second water tempering valve and minimize thermal hunting.
[0022] A secondary heat exchanger may also be provided having a first side for receiving hot condensate from the steam traps and having a second side. An additional water circulation circuit circulates a source of relatively colder water through the second side of the secondary heat exchanger to preheat the source of relatively colder water. The preheated water is circulated to the inlet of the first and second process heat exchangers. Preferably, the heat exchange system of the invention is used to supply hot water to a building having an existing building water recirculating circuit and water recirculating pump. The existing building water recirculating pump is used to pump relatively cooler building return water through the secondary heat exchanger to preheat the relatively cooler building water.
[0023] The secondary heat exchanger can also be provided with its own recirculating pump or pumps for building systems which do not have an adequate stand-alone recirculating water system. As an added safety measure, the secondary heat exchanger can also be provided with an appropriately located temperature sensor which detects a steam trap failure in the system. In this case, a by-pass valve or valves redirect the steam/condensate from the steam trap to the condensate out line, thereby preventing an undesirable rise in the temperature at the cold water inlet to the system.
[0024] The system also preferably has a first temperature limiting device associated with the first water tempering valve and a second temperature limiting device associated with the second water tempering valve. The first temperature limiting device senses the water temperature in the blended water outlet of the first water tempering valve and acts to shut off the flow of hot water if the sensed temperature exceeds a predetermined limit. The second temperature limiting device senses the water temperature in the blended water outlet of the second water tempering valve and acts to shut off the flow of hot water if the sensed temperature exceeds a predetermined limit.
[0025] The water circulating circuit leading to the cold inlet of the second water tempering valve has a metering valve mounted therein. Each of the metering valves has a range of open positions and a fully closed position with a fixed orifice. The fixed orifice which is present in the fully closed position serves to maintain a minimum flow of cold water in the fully closed position in order to insure that water exiting the water tempering valve does not become too hot.
[0026] The heat exchange system of the invention also includes a rigid support frame for supporting one or more and preferably at least two, process heat exchangers and associated piping and components. The rigid support frame has a pair of spaced vertical support members connected by an upper and a lower cross member. The upper cross member has one or more angularly oriented support flanges mounted thereon for receiving an upper extent of process heat exchanger to support the heat exchanger. In this way, any load imposed by associated heat exchanger piping and components is transferred to the support stand through the support flange. The stand also includes an adjustable lower mounting bracket for each of the process heat exchangers which mounts on the lower cross member of the support stand for further stabilizing the process heat exchangers on the support stand. The upper cross member of the support stand is appropriately located to provide support for heavy components of the water blending valve and components with the components being approximately balanced on either side of the cross member. The lower cross member of the support stand is appropriately located to serve as a hanger support attachment point to carry the weight of the process heat exchanger associated lower piping, the secondary heat exchanger and associated components. The support stand can easily be expanded to accommodate multiple additional heat exchangers and water blending systems by extending the cross members.
[0027] Each of the vertical support members of the support stand is attached to a runner skid by means of a gusset member, each gusset member being positioned to contact a vertical support member at a planar contact surface. Each of the gusset members is preferably welded across the planar contact surface using a skip welding process to minimize heat deflection on the runner skid.
[0028] Each of the process heat exchangers has a steam side and a water side. Preferably, a backflow preventer valve is installed in a cold water supply conduit leading to the water side of each heat exchanger to maintain pressure on the heat exchanger if system water pressure is lost. Each of the process heat exchangers has a hot water outlet connected to a respective one of the water tempering valves by a portion of downward piping of a hot water conduit. The first water tempering valve of each of the process heat exchangers is mounted on the support stand at a selected horizontal elevation, the selected horizontal elevation being below the respective horizontal elevation of the process heat exchanger hot water outlet, the downward piping serving to act as a heat trap to retain hot water in the respective process heat exchanger during periods of no flow of hot water from the heat exchanger.
[0029] Additional objects, features and advantages will be apparent in the written description which follows.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] FIG. 1 is a simplified, schematic diagram illustrating the operation of the heat exchange system of the invention.
[0031] FIG. 2 is a front elevational view of the heat exchange system of the invention showing the principal components thereof;
[0032] FIG. 3 is a side view of the heat exchange system of FIG. 2 .
[0033] FIG. 4 is an isolated side view of the stand which is used to support the heat exchange components, valving and piping of the heat exchange system of the invention.
[0034] FIG. 5 is an isolated view of a portion of the skid runner and base of the stand of FIG. 4 , showing the weld detail thereof.
[0035] FIG. 6 is a front elevational view of the isolated stand of the invention.
[0036] FIG. 7 is an isolated view of the bottom clamp used to mount a process heat exchanger on the stand of FIG. 6 .
[0037] FIG. 8 is an isolated view of the top heat exchanger mounting flange used with the stand of the invention.
[0038] FIG. 9 is a side view of the flange of FIG. 8 .
[0039] FIG. 10 is an isolated side view of certain of the piping components of the system of the invention.
[0040] FIG. 11 is a top view, similar to FIG. 10 , of the piping components of the system.
[0041] FIG. 12 is an isolated view of the plate heat exchanger and related piping which makeup the secondary heat exchanger of the system of the invention.
[0042] FIG. 13 is an isolated view of the plate heat exchanger of FIG. 12 .
[0043] FIG. 14 is a schematic diagram, similar to FIG. 1 , showing another version of the system of the invention which includes the addition of a steam trap safety feature.
DETAILED DESCRIPTION OF THE INVENTION
[0044] FIG. 1 is a schematic diagram illustrating the operational flow of the heat exchange system of the invention. In one embodiment, this instantaneous water heater system utilizes steam from a local boiler or district plant to provide energy to heat water up to a desired temperature for a variety of hot water end use applications. The water temperature control scheme which is illustrated in FIG. 1 and which will be described in greater detail herein operates with equal precision whether hot water or another hot fluid is used as the energy source to heat the process water up the desired end use temperature, or whether steam is utilized as the energy source.
[0045] The basic building blocks of the heat exchange system are a first process shell-and-tube 11 having a cold water inlet 13 . Preferably, at least a second process shell-and-tube heat exchanger 15 is provided also having a cold water inlet 17 and being mounted in water circulating circuit 19 in parallel fashion with the first process heat exchanger 11 to provide redundancy in the case of the failure of either of the first and at least second heat exchanger systems 11 , 15 .
[0046] Each of the process heat exchangers 11 , 15 are of conventional design. The particular heat exchangers which are illustrated contain a tube coil or bundle within an outer shell and a steam source 21 is provided for continuously supplying steam to a selected one of the shell-and-tube heat exchangers 11 , 15 . Preferably, the steam is supplied to the tube bundle side of the exchanger at about 250° F. with the water to be heated passing around the tube bundle through the heat exchanger shell.
[0047] When steam is used as the energy source, the steam flow through the heat exchangers 11 , 15 is controlled by steam traps 23 , 25 , located in an outlet conduit 24 , 26 from each heat exchanger tube bundle. As relatively colder water enters each heat exchanger 11 , 15 through the heat exchanger shell, heat is transferred from the steam in the tube bundle to the surrounding water in the shell, thus condensing the steam and creating steam condensate. Each steam trap 23 , 25 is set to open when a preset weight of condensate has been collected. As the steam traps 23 , 25 open to discharge a preset amount of condensate, additional steam is able to enter each heat exchangers tube bundle which provides additional heat for transfer to the water in the heat exchanger shell.
[0048] As has been briefly discussed in the Background section of the application, the heat exchangers 11 , 15 are sized to provide the heat transfer capability required to obtain the desired quantity of heated water from the system. The system also provides a unique control system which adapts to changes in demand on the system. In most applications, the temperature of the water to be heated varies dramatically according to the time of year and other factors. Also, in most applications, the quantity of water flowing through the heat exchanger tube bundles varies according to the time of day and use patterns of the application. The heat exchanger outlet water temperature must be regulated in order to accommodate variability resulting from the inlet water temperature and flow rate changes. However, Applicant's system does not attempt to control the outlet water temperature by controlling the steam flow through the heat exchanger using a temperature responsive valve. Systems which attempt to control the steam flow in this manner have an inherent thermal lag. As a result, the outlet water temperatures typically vary greatly when faced with wide swings and inlet water temperature and flow rates. These swings can exceed 50% of the difference between the cold water temperature and the desired hot water temperature when flow through the water heater changes quickly from full water flow capability to zero flow and back to full flow.
[0049] The present system operates upon a different principal in which hot water produced by the heat exchangers 11 , 15 is always hotter than the required outlet temperature. As will be explained in greater detail, the overheated water flows into a series of water tempering valves to blend hot and cold water to achieve the ultimately desired outlet water temperature. The input of the steam from the steam source 21 to the heat exchanger tube bundle is unregulated and only controlled in terms of the condensate trap operation.
[0050] In one embodiment of the invention, the system provides accurate temperature regulation at constant flow rates and also allows temporary temperature excursions as the flow rate varies. This cruder type of control is often acceptable for industrial applications. In another embodiment of the device, the outlet water temperature downstream of the heat exchangers 11 , 15 is controlled to within plus or minus 5° F., or less, at any flow rate exceeding five gallons per minute. Since the five gallons per minute flow rate is easily achieved with a regularly installed building piping loop recirculation pump, the tight water temperature control applies to all flow conditions, including near instantaneous changes between maximum water flow to zero flow and back to maximum flow.
[0051] To obtain this type water temperature control during varying water volume usage, each of the first and at least second heat exchangers 11 , 15 also has associated therewith a first and second water blending valves mounted in series, such as valves 27 , 29 for heat exchanger 11 and valves 31 , 33 for heat exchanger 15 . As can be seen from FIG. 1 , the water blending valves are mounted in series with each water blending valve having a cold inlet port 35 , a hot inlet port 37 and a blended water outlet 39 , using blending valve 27 as an example. Water from the blended outlet 39 of the first water blending valve 27 is directed to the hot inlet port 41 of the second water blending valve 29 . The first water blending valve 27 acts to blend cold water and hot water to a predetermined temperature set point which is above a set point of the second watering blending valve 29 to thereby bias the second water blending valve and minimize thermal hunting. For example, the set point of the first blending valve 27 is preferably set at about 10-30° F., most preferably about 20-25° F. higher than the blending valve 29 . Because the second valve 29 does not see as wide a temperature fluctuation as the first valve 27 , valve fluctuation and thermal hunting is minimized. An additional benefit of using two tempering or blending valves in series is the fact that the failure of a single valve would not allow excessively hot water to discharge from the water heater outlet. If the first water blending valve 27 fails in the full hot open position, the second water blending valve 29 will control the water temperature well below a maximum water temperature set condition. Likewise, a failure of the second water blending valve 29 in the full hot open position would result in water temperature being controlled by the first water blending valve 27 .
[0052] In addition to the redundancy provided by the two water blending valves 27 , 29 for each heat exchanger 11 , 15 a first temperature limiting device 43 is associated with the first water blending valve 27 and a second temperature limiting device 45 is associated with the second water blending valve 29 , for each of the heat exchanger systems. The first temperature limiting device 43 is operable to sense water temperature in the blended water outlet of the first water blending valve 27 and to shut off the flow of hot water if the sensed temperature exceeds a predetermined limit. In similar fashion, the second temperature limiting device 45 is operable to sense water temperature in the blended water outlet of the second water blending valve 29 and to shut off the flow of hot water if the sensed temperature exceeds a predetermined limit.
[0053] As an additional safety measure, the water circulating circuit 19 leading to the cold water inlet 35 of each secondary water blending valve has a metering valve 47 , 49 mounted therein. Each of the metering valves is a gate valve having a range of open positions and a fully closed position which preset a fixed orifice. The fixed orifice serves to maintain a minimum flow of cold water even when the valves 47 , 49 are in the fully closed position, to ensure that water exiting the water blending valve in question does not become too hot. A water backflow preventer in the form of a check valve 51 , 53 is also installed in the cold water supply conduit leading to the cold water inlet 17 of each heat exchanger to maintain pressure on the heat exchanger if the system water pressure is lost.
[0054] As also will be appreciated with respect to FIGS. 1 and 2 , each of the process heat exchangers 11 , 15 have a hot water outlet 55 , 57 which is connected to a respective one of the water blending valves (such as valve 27 in FIG. 1 ) by a portion of downward piping 59 of the hot water conduit. The first water blending valve (for example, valve 27 ) is therefore mounted (see FIG. 2 ) at a selected horizontal elevation, the selected horizontal elevation being below the respective horizontal elevation of the process heat exchanger hot water outlet 55 . The downward piping 59 serves to act as a heat trap to retain hot water in the respective process heat exchanger 11 , 15 during periods of no flow of hot water from the heat exchanger. In other words, the heat trap prevents heat from migrating into the remainder of the plumbing at no flow conditions.
[0055] Returning to FIG. 1 , in one embodiment a secondary heat exchanger 61 is also provided having a first side for receiving hot condensate from the steam traps 23 , 25 and having a second side. An additional water circulation conduit 63 is provided for circulating a source of relatively colder water through the second side of the secondary heat exchanger 61 to preheat the source of relatively colder water. The preheated water exiting the secondary heat exchanger 61 is circulated through the primary cold water circulation circuit 19 to the cold inlet of the first and second heat exchangers 11 , 15 .
[0056] Where the heat exchange system is used to supply hot water to a building having an existing building water recirculating circuit and a water recirculating pump, the existing building water recirculating pump can be used to pump relatively cooler building return water through the secondary heat exchanger 61 to preheat the relatively cooler building water before again passing it through the process heat exchangers 11 , 15 . The building return water is “relatively cooler” than the steam condensate, even though it is a part of the building hot water recirculating circuit.
[0057] FIG. 13 shows the secondary heat exchanger in isolated fashion. In this case, the heat exchanger 61 is a plate type exchanger of conventional design. The heat exchanger receives return water at, for example 108° F., and discharges relatively hotter water at, for example 130° F., after heat exchange with the steam condensate which is typically at about 212° F. The outlet conduit ( 62 in FIG. 10 ) is connected to the cold water inlet conduit ( 64 in FIG. 2 ) by means of a flexible hose 66 which facilitates placement of the plumbing components on the support stand 65 .
[0058] FIG. 14 shows an additional feature of the invention in which the secondary heat exchanger 61 is provided with a safety protection feature which is designed to protect the system in the highly unlikely event that one or both of the steam traps 23 , 25 should fail. In the event of the failure of one of the steam traps 23 , 25 , the trap would essentially blow steam straight through the trap. The normal operation of the trap is to trap the steam and allow only condensate to pass through the trap. If steam were to blow straight through the trap 23 , 25 , it would tend to overheat the entire system due to the blending effect with the cold water inlet, especially in the event that the overall demand on the system is low at the time.
[0059] There are several technologies which can be used to detect a steam trap failure. For example, ultrasonic devices are known for this purpose. However, such devices are relatively expensive and overly complicate the system. Also, mounting a temperature or pressure sensor at the steam trap itself proved to be unworkable, since the failure does not make a large pressure or temperature differential which can be easily detected in this fashion.
[0060] Applicant's solution to the problem is to mount a temperature sensor 91 on the cold water inlet 93 to the system at a point downstream of the T-junction 95 at which the secondary heat exchanger output 97 is blended with the cold water inlet. In the example shown in FIG. 14 , the T-junction follows the check valve 99 . A normally open solenoid valve 101 is located in a first branch 103 of the inlet to the secondary heat exchanger 61 . A normally closed solenoid valve 105 is located in by-pass branch 107 of the circuitry. The temperature sensor 91 is set in a desired range, for example, from about 80-90° F. If a temperature value is sensed which exceeds a preset limit, for example 120° F., the valve 101 closes and the valve 105 opens. This effectively by-passes the secondary heat exchanger 61 so that recirculated water in the recirculation line 63 is not being further heated by steam/condensate passing from the steam traps 23 , 25 . While it might seem logical to sense the temperature in the recirculation line 63 , this line also gets hot in periods of high demand. Thus, sensing the temperature at the particular point 91 in the system (illustrated in FIG. 14 ) has proved to be most efficient. This sensor only sees a significant temperature increase if there is a problem in the system. The increase is also an immediate, dramatic effect which provides a reliable indication of a problem in the system.
[0061] FIG. 14 also shows the system of the invention being provided with its own recirculating water pumps 109 , 110 , each of which has an associated pair of gate valves 111 , 113 . The addition of the independently operable recirculation pumps 109 , 110 frees the system from dependent on the normal building water recirculation system which such system is insufficient or non-existent.
[0062] FIGS. 2-13 illustrate additional structural features of the heat exchange system of the invention. As best seen in FIGS. 2, 4 and 6 , a rigid support frame or stand 65 is provided for supporting the first and second process heat exchangers 11 , 15 and associated piping and components. The rigid support stand 65 has a pair of spaced vertical support members 67 , 69 ( FIG. 6 ) connected by an upper and a lower cross member 71 , 73 , respectively. The upper cross member 71 , as shown in FIGS. 2 and 6 has an angularly oriented support flange ( 75 illustrated in FIG. 6 ) mounted thereon for receiving an upper extent (generally shown as 77 in FIG. 2 ) of a selected one of the process heat exchangers to support the heat exchangers. As shown in FIG. 8 , the support flange 75 has a generally U-shaped opening 79 for engaging and supporting the heat exchanger 11 . This also isolates the weight of the steam inlet 21 and associated piping ( 81 in FIG. 3 ), whereby the load imposed by the associated heat exchanger piping and components is transferred to the support stand 65 through the support flange 75 .
[0063] As shown in FIGS. 2,3 , and 7 , an adjustable lower mounting bracket 83 is provided for each of the process heat exchangers 11 , 15 and mounts on the lower cross member 73 of the support stand 65 for further stabilizing the process heat exchangers on the support stand.
[0064] As will be appreciated, the heat exchanger flange support system provides support for the process heat exchangers 11 , 15 to transfer steam piping angular and support loads to the stand 65 . Traditional heat exchanger mounting arrangements have tended to result in all of the steam piping loads being carried by the flange to shell attachment. These loads can be substantial and can damage the flange to shell connection and cause other piping attached to the heat exchanger to move out of position or incur stress which can result in stress corrosion failure of certain heat exchanger designs and/or materials. Bolts 84 ( FIG. 7 ) are received in a mating slot on the cross member 73 which allow adjustment of the vertical position of the mounting brackets 83 .
[0065] In order to accommodate the position of the heat exchanger after it is mounted to the stand 65 by the flange 75 , the adjustable lower mounting bracket 83 is designed to attach to the heat exchanger in whatever position results from the flange mounting. The traditional strap type mounting method forces the heat exchanger to be held in a fixed position defined by the fixed saddle of the strap system. If the flange mounted heat exchanger of the invention was forced into this fixed saddle location and held in place by the strap position of the strap system, undesirable stress would be applied to the heat exchanger flange to shell connection.
[0066] As will also be appreciated with respect to FIG. 2 , the upper cross member 71 is designed to provide support for the heavy components of the water blending system, such as valve 27 and its associated plumbing, which are approximately balanced on either side of the cross member 71 and which can be attached to it by an adjustable clamping system or other suitable arrangement. Similarly, the lower cross member 73 is designed to serve as a hanger support attachment point to carry the weight of the lower piping, secondary heat exchanger and associated components of the water blending system.
[0067] The steam instantaneous heat exchangers of the invention are designed for single or multiple attachments to the support stand 65 . When provided as a multiple water heater, the individual water heater design accommodates attachment for combined inlet and outlet single point water connections. However, as has been discussed, multiple units can provide redundancy and can provide for higher water delivery. The support stand 65 can be expanded to accommodate multiple heat exchanger and water blending systems through the extension of the cross members 71 , 73 .
[0068] The frame weld design of the stand 65 is also customized in order minimize weld distortion at the frame. With reference to FIGS. 3-5 , each of the vertical support members, such as member 67 in FIG. 5 , is attached to a runner skid 85 by means of a gusset member 87 . Each gusset member 87 is positioned to contact a vertical support member 67 at a planar contact surface. Each gusset member is welded across the planar contact surface using a skip welding pattern, such as the skips illustrated at 89 in FIG. 5 . For example, instead of using a full weld, approximately ½″ skips are provided to minimize the weld that crosses the flat side of the skid 85 in FIG. 5 . This tends to minimize stress on the runner skids 85 and prevents buckling.
[0069] FIGS. 2 and FIGS. 10-13 illustrate additional components of the plumbing, including the plumbing related to the secondary heat exchanger 61 . As briefly discussed, where the building or other structure being serviced has an existing return recirculation pump and water circuit, the significant energy which is contained in the steam condensate in the traps 23 , 25 can be used to preheat the recirculated return water, thereby improving the efficiency of the system. The energy from the steam traps 23 , 25 can be captured and used to preheat the water coming into the heat exchangers 11 , 15 by using the secondary heat exchanger or sub-cooler 61 . Traditionally, the building water circulation system will have a pump added to the system to move a portion of the cold supply water through the secondary heat exchanger 61 , followed by adding this heated water back into the cold water entering the process heat exchanger. In one embodiment of the invention, the existing building recirculation pump (not shown) is used to pump the cooler building return water through the secondary heat exchanger 61 and then into the cold water inlet of the process heat exchanger 11 , simplifying the piping system and avoiding the cost of an independent secondary heat exchanger pump. Other arrangements are also possible. For example, a “T” and balancing valves could be added to the suction side of the existing building recirculation pump so that the one pump can return recirculated water and draw cold supply water through the secondary heat exchanger 61 through separate piping.
[0070] An invention has been provided with several advantages. The system of the invention utilizes steam from any convenient source to provide energy to heat water to a desired temperature for a variety of hot water end use applications. The thermal lag which has tended to characterize the prior art instantaneous systems is eliminated providing near instantaneous water temperature control. Outlet water temperature downstream of the water heater system can be controlled to within plus or minus 5° F., or less at any flow rate exceeding five gallons per minute. The five gallon per minute flow rate is easily achieved with a conventionally installed building pipe loop recirculation pump. The tight water temperature control achieved with the system of the invention applies to all flow conditions, including near instantaneous changes between maximum water flow to zero flow and back to maximum flow. A variety of safety features ensure that no scalding water or steam is delivered through the water outlets in the event of failure of major component of the system.
[0071] While the invention has been shown in several of its forms, it is not thus limited but is susceptible to various changes and modifications without departing from the spirit thereof. | An improved shell-and-tube steam instantaneous heat exchange system of a closely coupled feedback design which overheats water in the heat exchanger portion of the system and then blends the water, as needed, with proportional amounts of cold water to achieve the correct outlet temperature for a wide range of flow rates. The system uses at least two primary heat exchangers to provide redundancy in the case of failure of a major component of the system. Steam flow through the heat exchangers is controlled by the use of steam traps, rather than using a thermostatically controlled valve to vary the supply of steam. To obtain precise temperature control during varying water volume use, water is directed from the blended outlet of a first water tempering valve into the hot inlet port of a second water tempering valve. The first valve is designed to blend cold and hot water to a predetermined temperature which is higher than the second water tempering valve, so as to bias the second tempering valve, thereby minimizing thermal hunting and providing tighter temperature control from the second tempering valve. | 8 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an interior window frame assembly, and more particularly to an aesthetically pleasing interior window frame assembly for anchoring an interior window shutter thereto.
[0003] 2. Background and Related Art
[0004] Window coverings such as shades, blinds and shutters are commonly used to provide privacy in a room as well as to block or reduce incoming sunlight. Window shutters are particularly popular as they provide maximum privacy, versatility, durability and ease of use. Window shutters may be constructed from a variety of materials, although the most commonly used material is wood and/or composites, finished either with a traditional wood finish, paint or by a coating of plastic or other substance.
[0005] Regardless of the material used to construct window shutters, window shutters are typically heavier and more cumbersome than other types of window coverings. Accordingly, proper installation and use of durable supporting frames and hardware are critical to ensure that shutters do not detach upon repeated use.
[0006] Traditionally, wood or wood composite window frames have been implemented for this purpose. Although the type of wood used in frame construction may vary, wood frames are typically soft and bulky as they require a considerable amount of surface area to provide the degree of elasticity and strength needed to properly support the weight of an attached shutter. These characteristics make frame handling and installation difficult, and labor expensive.
[0007] Wood frames are especially difficult to implement where there is a preexisting window molding or irregularities in the dimensions of a window opening. Those skilled in the art have traditionally dealt with this problem by trimming and/or caulking a window frame to accommodate such irregularities. This solution, however, is both time consuming and inexact. Indeed, if a window frame is improperly trimmed or installed out of square with the window opening, it may not be able to support the weight of an attached window covering. Wood frames are also prone to warp, thus further compromising the frame's strength and squareness with respect to a window.
[0008] Further, a standard window frame that has become strained or deformed due to warping or improper positioning may fail to accommodate a standard size window covering. A window covering must then be customized to accommodate the proportions of the window frame. Alternatively, the window frame must be replaced, repositioned and/or re-secured as necessary to retain and support a standard window covering in square with the window opening.
[0009] These inherent characteristics and difficulties of window frame and shutter installation require considerable time and labor of even highly skilled carpenters. When a layman attempts shutter installation, window frame and shutter installation can be dangerous as well. Improper window frame and shutter installation, or use of materials in window framing that are inadequate to support the weight of a shutter may cause the shutter to detach, thereby increasing a likelihood of damage to property and/or personal injury.
[0010] Accordingly, what is needed is an aesthetically pleasing window frame assembly capable of easy installation by those with a minimum of carpentry knowledge. What is also needed is a lightweight, slim profile window frame assembly that may be easily implemented in connection with a preexisting window molding. Further what is needed is a window frame assembly that maintains squareness with a window over time. Finally what is needed is a window frame assembly that compensates for irregularities in the dimensions of the window opening such that the window frame may predictably and reliably accommodate a standard window covering.
[0011] The present invention overcomes the foregoing and other disadvantages of the prior art by providing a novel and improved window frame assembly.
SUMMARY OF THE INVENTION
[0012] The present invention is an aesthetically pleasing, slim profile window frame assembly that is capable of retaining a shutter. Specifically, the window frame assembly of the present invention comprises a core substrate coupled to a flange. Certain embodiments of the present invention comprise a core substrate having a thickness less than {fraction (5/16)} inch (7.9 mm) and having, by volume, an elastic modulus greater than wood. A flange comprises a depth sufficient to retain a hinge attached to a window covering, such as a shutter. Certain embodiments of the present invention provide for a decorative covering to be coupled to the core substrate and/or flange such that a portion of the window frame assembly is thereby concealed. A decorative covering may comprise wood, wood veneer, plastic, cloth and/or paint. The improved strength per volume of the present invention facilitates shutter installation by a “do-it-yourself” homeowner or handyman as well as by a skilled carpenter.
[0013] An object of the present invention is to provide an aesthetically pleasing window frame assembly capable of easy installation by a person with a minimum of carpentry knowledge.
[0014] Another object of the present invention is to provide a lightweight, slim profile window frame assembly that may be easily implemented in connection with a preexisting window molding.
[0015] It is a further object of the present invention to provide a window frame assembly that maintains squareness with respect to a window opening upon installation and over time.
[0016] A further object of the present invention is to provide a window frame assembly that compensates for irregularities in the dimensions of the window opening such that the window frame assembly may predictably and reliably accommodate a standard window covering.
[0017] These and other features and advantages of the present invention will be set forth or will become more fully apparent in the description that follows. The features and advantages may be realized and obtained by means of the instruments and combinations particularly pointed out in the appended claims. Furthermore, the features and advantages of the invention may be learned by the practice of the invention or will be obvious from the description, as set forth hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The foregoing and other objects and features of the present invention will become more fully apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. Understanding that these drawings depict only typical embodiments of the invention and are, therefore, not to be considered limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:
[0019] FIG. 1 is a perspective view of a window opening within a rigid wall structure configured to receive a window frame assembly in accordance with the present invention;
[0020] FIG. 2 is a perspective cut-away view of the perspective view of FIG. 1 , showing the internal wall members in relation to the overall wall structure and window opening, as well as in relation to the window frame assembly of the present invention;
[0021] FIG. 3 is a cross-sectional perspective view of a first embodiment of the core substrate and flange of the present invention;
[0022] FIG. 4 is a cross-sectional perspective view of a second embodiment of the core substrate and flange of the present invention;
[0023] FIG. 5 is a cross-sectional perspective view of a third embodiment of the core substrate and flange of the present invention;
[0024] FIG. 6 is a cross-sectional perspective view of a core substrate, flange and decorative covering in accordance with selected embodiments of the present invention;
[0025] FIG. 7 is a cross-sectional view of a core substrate, flange and decorative covering in accordance with a first embodiment of the present invention;
[0026] FIG. 8 is a cross-sectional view of a core substrate, flange and decorative covering in accordance with a second embodiment of the present invention;
[0027] FIG. 9 is a cross-sectional view of a core substrate, flange and decorative covering in accordance with a third embodiment of the present invention;
[0028] FIG. 10 is a flow chart delineating the steps for the method of installing the window frame assembly of the present invention;
[0029] FIG. 11 is a cut-away view of a method for adjoining perpendicular sections of a window frame in accordance with the present invention; and
[0030] FIG. 12 is a cut-away view of an alternative method for adjoining perpendicular sections of a window frame in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0031] The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope.
[0032] As used in this specification, the term “window covering” refers to any shutter, blind, shade or any other window covering known to those in the art capable of being supported and/or retained by the window frame assembly described herein. The term “window jamb” refers to the supporting wall structure perpendicularly adjoining an outer edge of an installed window. The term “adjacent wall” indicates the supporting wall structure adjoining, generally at a substantially right angle, a window jamb at an edge opposite the edge adjacent a window. The terms “mounting hardware” and “hardware” refer to any hardware or combination of hardware capable of retaining the window frame assembly of the present invention against a window jamb or adjacent wall, including, but not limited to, screws, bolts, rivets, nails, staples, adhesives and cement. “Elasticity” refers to a property of a material in which strains or deformations are recoverable after an applied stress is removed. The term “modulus of elasticity” or “elastic modulus” is the ratio of stress to strain, measured in pounds per square inch (psi). Values corresponding to a modulus of elasticity, abbreviated herein as “E,” are given in terms of million psi. Thus, a board with a modulus of elasticity of 2,100,000 psi may be reported as 2.1 E.
[0033] The present invention comprises a window frame assembly to facilitate the installation of a window covering 14 to cover an interior window 2 . Referring to FIG. 1 , an interior window 2 comprises a window surface 4 , an associated window jamb 6 , an adjacent wall 8 and an edge 12 common to the window jamb 6 and adjacent wall 8 . A preexisting window molding 10 may frame a window 2 proximate the common edge 12 . If, however, a window 2 does not employ a preexisting window molding 10 , the present invention contemplates such a molding 10 as an element of selected embodiments of the present invention.
[0034] FIG. 2 provides a perspective cut-away view of the elements of FIG. 1 . Particularly, FIG. 2 depicts internal wall stud members 18 in relation to an overall wall structure and window opening 2 , as well as in relation to the window covering frame assembly of the present invention. The window covering frame assembly of the present invention may be secured to a window jamb 6 or to an adjacent wall 8 by mounting hardware, or by any other means known to those skilled in the art. Preferably, as depicted in FIG. 7 , an industrial screw 34 is driven through a core substrate 20 into a window jamb 6 or adjacent wall 8 , and further into an internal stud member 18 . This securing technique ensures proper attachment and reliability of the window frame assembly over time. Similarly, it is also preferred to secure a core substrate 20 at relatively small intervals along a window jamb 6 or adjacent wall 8 to provide additional support for the window frame assembly and attached window covering thereby retained.
[0035] Referring now to FIGS. 3-5 , selected embodiments of the present invention comprise a core substrate 20 , wherein the core substrate 20 comprises fiberglass, aluminum, graphite, reinforced plastic, or any other metal or material, or combination thereof, recognized by those skilled in the art as capable of both having a slim profile and having an elastic modulus sufficient to retain an interior window covering 14 (see FIG. 7 ). A core substrate 20 further comprises an elongate lateral plate 22 having a perpendicularly attached flange 26 . Preferably, a thickness corresponding to each of the lateral plate 22 and the attached flange comprises less than {fraction (5/16)} inch (7.9 mm). Such a slim profile enables the window frame assembly of the present invention to be implemented in a variety of window openings 2 without interfering with the dimensions of the window opening 2 or with a preexisting window molding 10 in close proximity to the window opening 2 . In addition, the slim profile aspect of the present invention enables the window frame assembly to be transported and installed with minimal expense and labor.
[0036] A slim profile core substrate 20 preferably comprises a high degree of elasticity to facilitate its ability to retain an interior window covering 14 over time. Indeed, a relatively inelastic substrate requires relatively greater mass to retain any given window covering 14 . Although most presently known window frame assemblies are made of wood, wood is not preferred for use in the present invention due to its characteristically low elasticity. An elastic modulus value for wood varies according to the species of wood. For example, Eastern Red Cedar is very soft softwood having an elastic modulus of 0.88 E. Pignut Hickory, on the other hand, is one of the strongest hardwoods, having an elastic modulus of 2.26 E. As one particularly desirable feature of the window frame assembly of the present invention is its slim profile, the core substrate of the present invention 20 comprises an elastic modulus greater than wood, preferably greater than 2.3 E. In this manner, the core substrate 20 of the present invention may comprise a thickness of less than {fraction (5/16)} inch without compromising its structural integrity or the security of the interior window covering 14 thereby retained.
[0037] Referring now to FIG. 3 , a core substrate 20 may comprise a variety of cross-sectional configurations depending on the conditions, features and desired effects for a particular window opening 2 . Specifically, where a window opening 2 has a preexisting window molding 10 closely aligned with the common edge 12 , it may be desirable to implement a core substrate 20 and associated flange 26 , wherein the cross-sectional shape of the integrally formed or attached substrate 20 and flange 26 resemble an “L.” A flange 26 preferably comprises a width sufficient to retain a hinge 16 pivotably attached to a window covering 14 . An elongate lateral plate 22 of the core substrate 20 may be attached to a window jamb 6 or adjacent wall 8 by mounting hardware or by any other means known to those in the art. According to this embodiment of the present invention, the rigidity of the elongate lateral plate 22 enables the plate 22 to be attached to the window jamb 6 or adjacent wall 8 in such a manner that the plate 22 is parallel the window opening 2 , despite variances in the drywall, paint or other subsequently applied wall applications. In addition, the elongate lateral plate 22 may implement a connecting channel 42 (see FIG. 4 ) along its length that may be connected to a perpendicularly oriented connecting channel 42 along a second elongate lateral plate 22 to form the window frame assembly of the present invention. In this manner, the window frame assembly of the present invention ensures squareness with respect to the window opening 2 . This aspect of the present invention is discussed in more detail with reference to FIGS. 11 and 12 below. This embodiment of the present invention may also implement any one of a variety of decorative coverings 28 to conceal any void between the window frame assembly and existing window molding 10 , as discussed in detail with reference to FIGS. 6-9 below.
[0038] Referring now to FIG. 4 , certain alternative embodiments of the present invention comprise a core substrate 20 and a flange 26 integrally formed or attached to resemble, in cross-section, the shape of a “T”. According to such embodiments, the elongate lateral plate 22 of the core substrate 20 extends beyond the position of the flange 26 to create an extended edge 24 . The extended edge 24 may function to conceal and/or correct irregularities in the common edge 12 , as well as to retain a decorative covering 28 . A decorative covering 28 may comprise wood, plastic, paint, or any other material known to those in the art by which to substantially conceal an exposed portion of the core substrate 20 and/or enhance the appearance of the window opening 2 . Specifically, where a window opening 2 does not have a preexisting window molding 10 , the present invention contemplates implementing a window molding 10 as a decorative covering 28 attached to the core substrate 20 to substantially conceal the core substrate 20 as well as to enhance the overall appearance of the window opening 2 .
[0039] Like the embodiment of the present invention depicted as FIG. 3 above, the “T”-shaped embodiment of FIG. 4 implements a flange 26 wide enough to accommodate a hinge 16 pivotably attached to a window covering 14 , such as a shutter. The embodiment of FIG. 4 may also incorporate a connecting channel 42 aligned with the elongate lateral plate 22 to facilitate adjoining adjacent perpendicularly oriented lateral plates 22 to form a frame assembly in square with a window opening 2 .
[0040] Referring now to FIG. 5 , a core substrate 20 in accordance with the present invention may comprise a flange 26 perpendicularly disposed between two elongate lateral plates 22 and 27 on parallel planes such that a cross-sectional profile of the frame assembly thus formed resembles the shape of a “Z.” According to this embodiment of the present invention, like other embodiments previously discussed, the flange 26 comprises a width sufficient to accommodate a hinge 16 pivotably attached to a window covering 14 , such as a shutter. Further, an elongate lateral plate 22 may comprise a connecting channel 42 longitudinally disposed thereon to facilitate frame assembly as discussed above. Specifically, a corner bracket may be implemented to adjoin the connecting channel 42 of a first elongate lateral plate 22 to a perpendicularly oriented connecting channel 42 of a second elongate lateral plate. The “Z” orientation of the present embodiment enables the window covering to be mounted inside the window opening 2 while enabling a peripheral elongate lateral plate 27 to conceal and/or correct irregularities in the corner edge 12 . Further, the peripheral elongate lateral plate 27 may function to retain a decorative covering 28 of the user's choice.
[0041] Referring now to FIG. 6 , a core substrate 20 and/or flange 26 may incorporate one or more retaining tabs 30 to receive a decorative covering 28 . A decorative covering 28 preferably comprises wood or wood composite decoration resembling a traditional wood molding. Unlike a traditional wood molding, however, the decorative covering 28 may incorporate notches 32 corresponding to retaining tabs 30 provided in the core substrate 20 . The decorative covering 28 may be attached to the core substrate 20 by aligning the notches 32 with the retaining tabs 30 and pressing the decorative covering 28 against the core substrate 20 to ensure a press fit.
[0042] Alternatively, a decorative covering 28 may be retained against a core substrate 20 by traditional fastening means, including but not limited to mounting hardware and/or any other fastening means known to those in the art. A decorative covering 28 may further employ a channel 44 within its underside surface to accommodate any portion of a screw or other hardware that may project from the wall subsequent to its use in securing a core substrate 20 in place.
[0043] In addition, a decorative covering 28 may comprise a plurality of interlocking components. By way of example and not limitation, the decorative covering 28 may comprise a frame base 38 and a concealing strip 40 , where the frame base 38 may further comprise a groove configured to retain a tongue of the concealing strip 40 . When the concealing strip 40 is properly disposed into the frame base 38 , the two components form a locking tongue and groove junction, thereby concealing any hardware used to affix the decorative covering 28 to an adjacent wall 8 . Further, where the frame base 38 is properly positioned in relation to a core substrate 20 , a screw or other mounting hardware known to those in the art may be driven through both the frame base 38 and the core substrate 20 to affix both to an adjacent wall 8 . A concealing strip 40 may then be disposed into the frame base 38 to conceal such screw or other mounting hardware.
[0044] Referring now to FIG. 7 , a core substrate 20 may incorporate a hardware concealing channel 36 into an elongate lateral plate 22 to facilitate installation of the window frame assembly of the present invention. The hardware concealing channel 36 may be premarked or predrilled to receive a screw 34 or other mounting hardware, wherein such screw 34 ultimately engages an internal stud member 18 to fensure that the window frame assembly and attached window covering securely attach to the window opening 2 .
[0045] According to one aspect of the embodiment of the present invention depicted by FIG. 7 , a decorative covering 28 may comprise a substantially rigid insert 46 having dimensions appropriate to accommodate any void resulting between a preexisting window molding 10 and the window frame assembly when the window frame assembly is properly installed in square with the window opening 2 . Such an insert 46 may comprise wood, plastic or any other material known to those in the art capable of decoratively concealing a gap otherwise existing between the window frame assembly and a window molding 10 . According to this aspect of the present invention, a recess may be longitudinally disposed along the depth of the window molding 10 to retain a portion of the insert 36 therein. The core substrate 20 and/or flange 26 may also implement an insert engaging piece 48 to further secure the insert 46 in a substantially fixed position relative to the window frame assembly and preexisting window molding 10 .
[0046] Referring to FIG. 8 , it is not uncommon to witness substantial variation in the dimensions of voids existing between the window frame assembly and a preexisting window molding 10 along a length of a window opening 2 . A deformable material capable of accommodating such variation is thus preferred. According to certain embodiments of the present invention, a decorative covering 28 comprises a deformable material including, but not limited to, foam rubber, flexible plastic or composite fill, which functions to substantially conceal any gap otherwise present between the window frame assembly and a window molding 10 .
[0047] In selected embodiments, a decorative covering 28 comprises deformable plastic. According to this embodiment of the present invention, an edge of a plastic strip 50 attaches to an externally exposed surface of the flange 26 at a point beyond the common edge 12 . The plastic strip 50 may be provided having a width sufficient to enable the plastic strip 50 to be substantially retained in either a flexed or relaxed state between the flange 26 and a window molding 10 to substantially conceal a uniform or non-uniform gap otherwise existing therebetween.
[0048] Referring now to FIG. 9 , a decorative covering 28 may alternatively be implemented as a deformable and substantially resilient material such as foam rubber. Such a decorative covering 28 may optionally comprise a hollow channel to enhance its resiliency. According to one aspect of the present embodiment of the present invention, a window frame assembly may further comprise an engaging member 52 affixed to an externally exposed surface of the attached flange 26 . Alternatively, the engaging member 52 may be integrally formed with the flange 26 . In selected embodiments, the decorative covering 28 comprises an aperture conforming to the engaging member 52 such that the engaging member 52 effectively retains the decorative covering 28 in a substantially fixed position relative to the flange 26 .
[0049] Referring now to FIG. 10 , a method for installing the window frame assembly of the present invention may depend on whether the subject window opening 2 bears industry standard dimensions. If the answer is yes, it will likely be possible to purchase a window frame assembly pre-sized to accommodate the subject window opening 2 , thus circumventing steps one and two of the present method. If the window is irregularly shaped or bears unique dimensions, on the other hand, the first step for installing the window frame assembly of the present invention may be to measure the window opening dimensions 60 , after which a core substrate and decorative covering may be appropriately sized 62 . The third step comprises substantially adjoining adjacent core substrates 64 to form a window frame. This step may be accomplished by any means known in the art, including, but not limited to, mitering and bracketing abutting edges. In addition, the third step 64 may be facilitated by connecting channels 42 longitudinally disposed along each elongate lateral plate 22 , as discussed above. A fourth step comprises securing the window frame adjacent a window opening 66 such that the window frame is substantially in square with the window opening. An optional fifth step 68 provides for affixing a shutter or other window covering to at least a portion of the window frame such that the window covering may be substantially retained thereby. A final step 70 contemplates engaging a decorative covering with at least a portion of the window frame such that the decorative covering may be retained substantially adjacent an adjacent wall and proximate a window opening.
[0050] Referring to FIG. 11 , an external bracket 80 may be used to join and reinforce a mitered joint between lengths of a window frame assembly, as discussed above with reference to the third step of the method of FIG. 10 . The external bracket 80 may be attached to each decorative covering 28 and/or core substrate 20 and flange 26 forming the mitered joint using one or more screws or other suitable means of attachment such as rivets, bolts and the like. In certain embodiments, flat head screws that sit flush with the surface of the external bracket 80 may be used.
[0051] Referring to FIG. 12 , in certain embodiments an internal bracket 82 may be used to reinforce and join a mitered joint between lengths of a window frame assembly. For example, as discussed above, an elongate lateral plate 22 may incorporate a connecting channel 42 longitudinally disposed thereon. An internal bracket 82 may then be affixed to each of two perpendicularly oriented connecting channels 42 disposed upon adjacent lengths of window frame to secure the associated core substrates 20 and/or brackets 26 in square. Screws or other attachment means may extend through any decorative coverings 28 into the internal bracket 82 to further ensure a fixed relationship between adjacent decorative coverings 28 . | An aesthetically pleasing, slim profile window frame assembly that is capable of retaining a shutter. Specifically, the window frame assembly of the present invention comprises a core substrate coupled to a flange. Certain embodiments of the present invention comprise a core substrate having a thickness less than {fraction (5/16)} inch and having, by volume, an elastic modulus greater than wood. A flange comprises a depth sufficient to retain a hinge attached to a window covering, such as a shutter. Certain embodiments of the present invention provide for a decorative covering to be coupled to the core substrate and/or flange such that a portion of the window frame assembly is thereby concealed. The improved strength per volume of the present invention facilitates shutter installation by a “do-it-yourself” homeowner or handyman as well as by a skilled carpenter. | 4 |
PRIORITY UNDER 35 U.S.C SECTION 119(e) & 37 C.F.R. SECTION 1.78
This nonprovisional application claims priority based upon the following prior U.S. Provisional Patent Application entitled: Ironing Board, Application No. 61/766,069 filed Feb. 18, 2013, in the name of Matthew Puckett, which is hereby incorporated by reference for all purposes.
FIELD OF THE INVENTION
The present invention relates to ironing boards, more specifically but not by way of limitation, an ironing board that is operable to provide increased lateral stability and further provide power cord management of a conventional clothes iron. Additionally, the ironing board of the present invention will provide a retention bracket for an iron that will not impede the ironing surface area.
BACKGROUND
As part of a normal caretaking routine, individuals routinely launder their clothes to maintain their cleanliness. During subsequent washing and drying of their clothes some fabrics may develop at least a certain amount of wrinkles Many individuals consider wrinkled clothes undesirable and will utilize an iron to substantially reduce the amount of wrinkles in the article of clothing. Most individuals will utilize a convention ironing board with an iron and manipulate the article of clothing in numerous positions to eliminate most of the wrinkles from the article of clothing.
There are numerous inherent problems with the conventional ironing board that has existed for decades. One major problem is the instability of a conventional ironing board. A conventional ironing board utilizes a pair of pivotal legs that are positioned in an angular manner with respect to each other in underneath and in general axial alignment with the ironing board. This design has shown to promote significant lateral instability. As the legs of a conventional ironing board do not extend beyond the perimeter edge of the board and with most ironing boards being at least four feet in height, the conventional design provides almost no lateral stability.
Another issue with conventional ironing boards is that they provide no cord management for the iron being used therewith. Typically a user will place the ironing board proximate an electrical outlet and plug in the iron. A conventional iron utilizes a power cord that provides power to the iron to heat the heating element. The cord presents a significant safety hazard to those using the ironing board or those walking proximate thereto. Users and/or those walking adjacent to the ironing board and iron often trip on the cord, which can cause significant injury to the individual who has become entangled with the cord. As a person trips on the cord the iron can fall off of the board and impact the person causing injuries ranging from burns to blunt trauma. Additionally, a falling iron can be a fire hazard and/or damage the flooring or nearby objects.
A further issue with a conventional ironing board is the lack of ability to maintain a controlled position of the iron superposed thereon. As a user manipulates the article of clothing being ironed the iron is typically placed on the opposite end of the board. As previously discussed, the inherent lack of lateral stability creates a scenario where the iron is routinely knocked off of the ironing board creating an additional safety hazard.
Accordingly, there is a need for an ironing board that has improved lateral stability, a power cord management system for an iron and a means to maintain the iron in a stable position when a user is manipulating an article of clothing on the ironing board or when the iron is left unattended.
SUMMARY OF THE INVENTION
It is the object of the present invention to provide an ironing board that provides lateral stability and further includes an integrated power supply.
Another object of the present invention is to provide an ironing board that provides lateral stability that includes a leg base wherein the leg base includes rotatably mounted members functioning to be positioned to provide enhanced lateral stability.
Yet another object of the present invention is to provide an ironing board that includes a leg base wherein one section of the leg base has a vertical support member perpendicularly mounted thereto.
Still another object of the present invention is to provide an ironing board that includes a leg base wherein the leg base is operable to be folded for storage when the ironing board is not in use.
An additional object of the present invention is to provide an ironing board including a vertical support member that is adjustable so as to adjust the height of the ironing board.
A further object of the present invention is to provide an ironing board that includes power cord management capabilities, wherein the power cord management capabilities are integrated into the vertical support member.
Yet a further object of the present invention is to provide an ironing board wherein the power cord management capabilities allow a user to operably couple the power plug of an iron into one end of the vertical support member.
Another object of the present invention is to provide an ironing board that includes a horizontal support member, wherein the horizontal support member is generally rod-shaped and is operably coupled to the vertical support member in a perpendicular manner.
A further object of the present invention is to provide an ironing board with improved lateral stability that includes a rod positioned longitudinally underneath the ironing board surface that is configured to receive items such as but not limited to clothes hangars.
Yet another object of the present invention is to provide an ironing board that includes an ironing surface, the ironing surface being planar in manner and rotatably coupled to the horizontal support member wherein the ironing surface is configured to be secured in a plurality of positions for use such as but not limited to a substantially horizontal position.
Still another object of the present invention is to provide an ironing board that is operably coupled to a power outlet wherein a cord is coupled to the power management system disposed within the vertical support member proximate the leg base.
An additional object of the present invention is to provide an ironing board that further includes an iron holding member, the iron holding member being pivotally mounted to the end of the vertical support member distal to the leg base and above the ironing surface and wherein the iron holding member is operable to retain the iron in a stable position as a user manipulates an article of clothing on the ironing surface.
To the accomplishment of the above and related objects the present invention may be embodied in the form illustrated in the accompanying drawings. Attention is called to the fact that the drawings are illustrative only. Variations are contemplated as being a part of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete understanding of the present invention may be had by reference to the following Detailed Description and appended claims when taken in conjunction with the accompanying Drawings wherein:
FIG. 1 is a front view of the preferred embodiment of the present invention in its deployed position; and
FIG. 2 is a rear view of the preferred embodiment of the present invention in its deployed position; and
FIG. 3 is a detailed view of the iron holding member of the present invention; and
FIG. 4 is a rear perspective view of the frame of the present invention; and
FIG. 5 is a side view of the preferred embodiment of the present invention in its folded position.
DETAILED DESCRIPTION
Referring now to the drawings submitted herewith, wherein various elements depicted therein are not necessarily drawn to scale and wherein through the views and figures like elements are referenced with identical reference numerals, there is illustrated an ironing board 100 constructed according to the principles of the present invention.
Referring in particular to FIG. 4 submitted herewith, the ironing board 100 further includes frame 10 . The frame 10 is manufactured from a suitable durable material such as but not limited to metal tubing. The frame 10 functions to provide support for the ironing surface 99 and manipulate the ironing surface 99 intermediate a horizontal and a vertical position. The frame 10 further includes a leg base 15 . The leg base 15 comprises a first portion 17 and a second portion 19 movably mounted to opposing sides of the center support member 20 . The first portion 17 of the leg base includes a first section 21 and a second section 22 . First section 21 is proximate the center support member 20 and is movably secured thereto. The first section 21 includes a first end 24 proximate the center support member 20 . The first end 24 is concave in shape so as to mateably secure with the circumference of the center support member 20 . The concave shape of the first end 24 ensures a stable union exists between the first section 21 and the center support member 20 when the leg base 15 is in its deployed position. Opposite first end 24 is second end 26 . Second end 26 includes a plurality of apertures 27 journaled circumferentially therearound. Second end 26 facilitates the rotatable coupling of the first section 21 and the second section 22 . While not particularly illustrated herein, disposed within the second section 22 is a conventional spring pin or similar device that is operable to engage with on of the apertures 27 to secure the second section 22 in its desired position to the first section 21 . The second section 22 is rotatable one hundred and eighty degrees with respect to the first section 21 . By way of example but not limitation, in FIG. 4 the second section 22 is illustrated wherein the end 29 is pointed away from the viewing perspective. The second section 22 is rotatable such that end 29 can be rotated one hundred and eighty degrees wherein end 29 would be pointed towards the viewing perspective. In this position the leg base 15 has an overall general s-shape, wherein the end 29 is positioned one hundred and eighty degrees opposite of end 39 . In this position the overall ironing board 100 has significantly improved lateral stability in both directions.
The second portion 19 of the leg base 15 is constructed similarly to the first portion 17 and functions identically thereto as described herein. The second portion 19 further includes first section 33 having first end 36 and second end 39 with both first end 36 and second end 39 being constructed similarly to first end 24 and second end 26 respectively. Second end 39 has journaled circumferentially therearound apertures 41 that are operable to receive spring pin or similar mechanical fastener so as to releasably secure the first section 33 to the second section 34 . The first portion 17 and second portion 19 of the leg base are operably coupled to mounting sleeve 40 utilizing fastener 45 . Fastener 45 includes bars 46 , 51 , first rod 47 and second rod 48 operably coupled with first section 21 and first section 33 respectively. Bars 46 , 51 are secured to the mounting sleeve 40 utilizing suitable durable techniques such as but not limited to welding. The mounting sleeve 40 is surroundably mounted to the center support member 20 and slidably coupled thereto. Operably coupled to the mounting sleeve is knob 55 and rod 56 that function to allow the mounting sleeve to be moved intermediate its first position and its second position. The knob 55 and rod 56 are a conventional fastener that includes an inner portion such as but not limited to a nut that is operable to be biased against the interior of the center support member 20 so as to maintain the mounting sleeve 40 in its desired position. In its first position, the mounting sleeve 40 is proximate a support surface on which the ironing board 100 has been superposed and the first portion 17 and second portion 19 of the leg base 15 are in their deployed positions extending outward therefrom and generally perpendicular thereto, as shown in FIG. 4 herein. In its second position the mounting sleeve 40 is proximate the end 61 of channel 60 such that the first portion 17 and second portion 19 of the leg base 15 are in a folded position being generally adjacent to the center support member 20 , as shown in FIG. 5 herein. The channel 60 functions to allow the rod 56 to slidably move therein as the mounting sleeve 40 is traversed intermediate its first position and its second position. Those skilled in the art will recognize that numerous types of fasteners could be utilized to facilitate the movement and securing of the mounting sleeve 40 .
The center support member 20 is substantially hollow and manufactured from a durable rigid material such as but not limited to metal tubing. The center support member 20 includes first end 71 and second end 72 . Mounting sleeve 40 is operably coupled to the center support member 20 proximate the second end 72 as previously described herein. Slidably coupled with the center support member 20 proximate first end 71 is tube member 80 . Tube member 80 engages the center support member 20 such that the tube member 80 slidably travels within the interior volume of the center support member 20 . Tube member 80 is substantially hollow and includes channel 82 . Surroundably mounted to the first end 71 of the center support member 20 is fastener 85 . Fastener 85 includes a mounting sleeve 86 , knob 87 and rod 88 . The fastener 85 facilitates the releasable securing of the tube member 80 in a desired position. The tube member 80 is operable to adjust the height of the ironing surface 99 . Knob 87 is operable to control the tension of rod 88 so as to allow the tube member 80 to be transitioned to a desired position and subsequently secured. While a fastener 85 has been illustrated and discussed herein, it is contemplated within the scope of the present invention that numerous types of conventional fasteners could be utilized to control the functional of the tube member 80 as described herein. The tube member 80 further includes electrical outlet 90 . Electrical outlet 90 is secured within the tube member 80 utilizing suitable durable techniques and is operable to receive a conventional 120/220-volt plug from a conventional clothes iron. While not illustrated herein, the electrical outlet 90 has conventional wiring electrically coupled thereto that is disposed within the center support member 20 and propagating out therefrom proximate end 72 . The electrical outlet 90 functions to provide a power source proximate the ironing surface 99 so as to reduce challenges and safety risks of utilizing a power source that is not operably integrated with the ironing board 100 . Located above the electrical outlet 90 is mounting hole 95 . The mounting hole 95 is journaled through the tube member 80 and is operable to receive the mounting rod 105 of the iron support member 101 as further described herein. Secured to the tube member 80 opposite the mounting hole 95 is support bar 115 . Support bar 115 is secured to tube member 80 utilizing suitable durable techniques and is generally perpendicular thereto. The support bar 115 provides the structural required to support the ironing surface 99 . While not particularly illustrated herein, it is contemplated within the scope of the present invention that an additional support member could be secured intermediate the support bar 115 and tube member 80 . Support bar 115 has rotatably mounted therearound a sleeve 120 . The sleeve 120 is surroundably mounted to the support bar 115 and has secured thereon a pair of brackets 117 , 118 . The brackets 117 , 118 operably coupled the sleeve 120 to the ironing surface 99 so as to facilitate in the positioning thereof. The sleeve 120 is operable to facilitate the positioning of the ironing surface 99 intermediate a vertical position as shown in FIG. 5 and a horizontal position as shown in FIG. 2 . A wingnut 109 is present to releasably secure the sleeve 120 in a fixed position.
Referring in particular to FIG. 3 , a detailed view of the iron support member 101 is illustrated therein. The mounting rod 105 is manufactured from a suitable durable material and functions to operably coupled with mounting hole 95 . Subsequent to being coupled to the mounting hole 95 , the iron support member 101 is positioned such that it is laterally adjacent to the ironing surface 99 . This position eliminates any infringement of the ironing surface 99 so as to provide the full ironing surface 99 to a user for ironing. Pivotally coupled to the mounting rod 105 is brace member 130 . Brace member 130 is pivotally mounted utilizing conventional techniques such as but not limited to welding or mechanical fasteners. Brace member 130 further includes a first portion 131 and a second portion 132 that are contiguously formed. The first portion 131 and second portion 132 are formed in a general v-shape so as to form valley 133 . The v-shape of the brace member 130 functions to promote engagement with the arcuate rear portion of a conventional clothes iron. Secured to the first portion 131 and second portion 132 are the first side member 134 and second side member 135 respectively. The first side member 134 and second side member 135 are generally rod-shaped and are secured utilizing suitable durable techniques such as but not limited to welding. Operably coupled intermediate the first side member 134 and second side member 135 is the receiving member 138 . The receiving member 138 is comprised of four interconnected rods 137 forming a square aperture 139 . The receiving member 138 is pivotally connected to the first side member 134 and second side member 135 so as to facilitate positioning of the square aperture 139 in position to receive a portion of the front of a conventional clothes iron and subsequently pivot so as to allow the rear portion of a conventional clothes iron to engage the brace member 130 wherein the weight of the conventional clothes iron provides the necessary bias force to maintain its position therein. Those skilled in the art will recognize that the iron support member 101 could be formed in numerous different shapes and accomplish the desired functionality herein. While not particularly illustrated herein, it is contemplated within the scope of the present invention that the iron support member 101 further includes a heat resistant coating thereon such as but not limited to silicon. Additionally, it is contemplated within the scope of the present invention that the iron support member 101 could be releasably and/or pivotally secured such that the iron support member 101 could be removed from and/or folded under the ironing surface 99 .
The ironing surface 99 is a formed similarly to a conventional ironing surface having a first tapered end 198 and a flat end 199 . The ironing surface 99 is manufactured from a suitable durable material such as but not limited to metal. Secured to the bottom side 170 of the ironing surface 99 is support bar 185 . Support bar 185 is manufactured from a suitable durable material such as but not limited to metal and is secured utilizing suitable durable techniques intermediate tapered end 198 and flat end 199 . The support bar 185 is secured such that a void 186 is present intermediate the bottom side 170 and the support bar 185 . While no particular size of the void 186 is required, good results have been achieved having a void that is sufficient in size so as to accommodate a hook portion of a conventional clothes hangar. The support bar 185 provides support for a plurality of articles of clothing suspended on conventional clothes hangars. While the support bar 185 is illustrated herein as extending substantially the length of the ironing surface 99 , it is contemplated within the scope of the present invention that the support bar 185 could be manufactured in numerous different lengths.
Referring to the Figures herewith a description of the operation of the ironing board is as follows. In operation, a user will transition the ironing board 100 from its stored position, shown in FIG. 5 to its deployed position, illustrated herein in FIG. 2 . To deploy the leg base 15 , a user will engage knob 55 to release the tension to the mounting sleeve 40 wherein the user will slide the mounting sleeve 40 towards end 72 of the center support member 20 . As the leg base 15 is transitioned downward the first portion 17 and second portion 19 move outwards from the center support member 20 . During this movement the concave shaped first end 24 and first end 36 mateably secure against the center support member 20 as the first portion 17 and second portion 19 are moved such that they are perpendicular to the center support member 20 . Ensuing the tightening of knob 55 to secure the leg base 15 , the user will rotate the ironing surface 99 to a substantially horizontal position wherein the sleeve 120 facilitates the rotatable movement about the support bar 115 . Subsequent to positioning the ironing surface 99 and securing its position, the iron support member 101 is placed adjacent thereto wherein the mounting rod 105 is journaled into mounting hole 95 . A conventional clothes iron is then engaged with the iron support member 101 and electrically coupled with the electrical outlet 90 . If the user desires an alternative configuration of the leg base 15 so as to alter the lateral stability, the user may rotate either the second section 22 or second section 34 such that the leg base 15 is now formed in a general s-shape.
In the preceding detailed description, reference has been made to the accompanying drawings that form a part hereof, and in which are shown by way of illustration specific embodiments in which the invention may be practiced. These embodiments, and certain variants thereof, have been described in sufficient detail to enable those skilled in the art to practice the invention. It is to be understood that other suitable embodiments may be utilized and that logical changes may be made without departing from the spirit or scope of the invention. The description may omit certain information known to those skilled in the art. The preceding detailed description is, therefore, not intended to be limited to the specific forms set forth herein, but on the contrary, it is intended to cover such alternatives, modifications, and equivalents, as can be reasonably included within the spirit and scope of the appended claims. | An ironing board having a leg base operable to provide increased lateral stability and further having an integrated electrical interface. The ironing board includes a support frame having a center support member that is generally cylindrical and hollow. Slidably coupled to the second end of the center support member is a mounting sleeve. The mounting sleeve has pivotally secured thereto opposing and rotatable leg sections. An upper support member is slidably secured to the center support member proximate the first end of the center support member for height adjustment. The upper support member has secured thereto a mounting rod and sleeve. The mounting rod and sleeve are operably coupled with an ironing surface. An iron holding member is releasably secured to the upper support member being configured to retain a clothes iron. Further included is a hanging rod underneath the ironing surface for hanging of clothes. | 3 |
BACKGROUND OF THE INVENTION
This invention relates to machinery used in connection with packing and processing produce, and more particularly, to a novel and improved machine for use in removing or culling undesirable produce from the desirable produce.
In the instant embodiment shown, a device will be described and shown which is useful in culling raisins and specifically for removing raisins that are bad, by excessive mold, from those raisins which are good.
It is known in the prior art that raisins which are subjected to mold have a softer and inferior skin and that the insides of the raisins are very soft. Thus, subjecting these raisins to extremely hot water pressure causes the skin on the inferior raisins to break and leaves a soft, pliable substance from the raisins. Now the soft, pliable raisins are removed sometimes by the water, but in most cases they are very difficult to remove.
Problems occur with the mold is that the bad raisins or moldy raisins become soft and sticky and become subjected to rot. Should these bad raisins be allowed to ramin with the good ones, the entire stock of raisins in the lot may become bad.
The United States Department of Agriculture has set certain standards as to the percentage of bad raisins in the good raisins, and that standard has normally been below 4%. Oftentimes, it has been found that the percentage of bad raisins may reach as high as 60%, but in most cases after considerable rain damage, rain and moisture, they will remain around 40%.
As is known, raisins are made by removing ripe grapes from the vines and placing them on drying trays right in the field. The grapes are then allowed to dry in the sun. In most cases because the grapes are ripe in the dry season, no harm comes to the raisins because of rainfall, but in special unusual weather some of the raisins in some area may be caught in an unusual or early rain. The rainfall or the moisture causes the mold in the raisins while they are drying on trays in the field.
Oftentimes, the farmers find it desirable to wait as long as they can before they harvest the grapes for drying to make the raisins. The reason for allowing the grape to stay on the vine as long as possible is that it improves the sugar content, and hence, the weight of the raisins, causing an economic gain to the farmer. Should the grape be harvested early, the grapes do not have the high sugar content, and thus, they are skinny and do not maintain the desired weight.
The problem of waiting too long for the grape to gain desired sugar content and plumpness for the use in the raisins, is that usually it causes the drying raisins to approach the rainy seasons. When the rainy seasons do come, the moisture causes the mold on the raisins at an undesirable level.
At one time when the raisins were in the unacceptable range, that is above the 4% level, they were discarded and literally plowed under in the fields. Presently the raisins are culled over by hand, and that is, the bad raisins are removed from the good raisins by manual labor.
Yet to discard the good raisins just because there happens to be a high mold content in the entire overall batch is wasteful and creates an economic loss to the farmer.
Heretofore there has been no mechanized and automatic system for removal of the bad raisins from the good ones. Thus, it would be desirable to have a mechanized and automatic system whereby the bad raisins are separated from the sound raisins, so that the crops of raisins can be partially saved, thus saving the farmer from the economic losses created by having to discard his crop.
SUMMARY OF THE INVENTION
Briefly described, the present invention provides equipment for processing produce, and in the particular embodiment shown, equipment for processing raisins to remove therefrom raisins which have become spoiled due to mold. Basically, the invention includes a rotatable screened cylinder being mounted for rotation at an angle wherein one end of the cylinder is adapted to receive the raisins on the upper end and dispose of the raisins on the lower end. A plurality of spaced ribs are longitudinally disposed within the cylinder, on the inner side thereof, which lift the raisins and drop them to the bottom of the cylinder. The dropping of the raisins to the bottom of the cylinder causes the spoiled, soft, sticky raisins, which have heretofore been conditioned by hot water, to stick to the bottom of the screen and the raisins with strong skins remain losse from the screen. A plurality of spray nozzles are disposed on the outside of the cylinder and directed to cause a spray of water along a longitudinal line on the outside of the screen. A chute is disposed inside the cylinder and directly under the longitudinal line of the spray created by the spray nozzles. As the water from the spray nozzles washes the spoiled raisins that have stuck to the screen of the cylinder, they are washed into the chute and disposed of in a suitable manner. Meanwhile, the good raisins, that is, those with the firm skin that do not stick to the screen, are again lifted by the ribs within the cylinder and again dropped to the bottom of the screen.
For each revolution of the cylinder, the raisins are advanced downwardly towards the bottom of the angled cylinder until finally they are removed from the lower end thereof. But, each time that the ribs lift the raisins, they are again dropped firmly to the bottom of the screen. It has been found that with appropriate rotation of the screen, and angle thereof, that a desirable travel of the raisins is one foot per revolution. Thus, the raisins are "processed" on a 12 foot cylinder 12 times, before they are finally disposed of. It has been found that by using this method the raisins can then adhere to the required Department of Agriculture standards, that is, 4% mold per volume.
DESCRIPTION OF THE DRAWINGS
These and other features and advantages will become more apparent to those skilled in the art, when taken into consideration with the following detailed description, wherein like reference numerals indicate like and corresponding parts throughout the several views, and wherein:
FIG. 1 is a block diagram illustrating the present invention in a raisin processing assembly line;
FIG. 2 is a perspective view of the shown embodiment of this invention;
FIG. 3 is a side view of the shown embodiment of this invention;
FIG. 4 is a front view taken along the lines 4--4 of FIG. 3.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1 there is shown, in a somewhat schematic form of a block diagram, the step by step process of a processing system for treating raisins included in the present invention. Raisins are first received in a bin and are lifted on an elevator, 12. Then by rollers, belts or suitable means, they are progressingly moved on to a vibrator 14, where they are then substantially agitated so that the raisins are spread about and certain raisins, which include undesirable portions thereof, can be easily removed. In the next step, the raisins are moved to an overhead spray area where they are sprayed with hot water, this is done in station number 16 and 18 whereby the hot water will soften the skins of the raisins which are affected by mold and cause them to break down and actually tear apart in most cases. The sound raisins have a very tough skin, and will not be damaged by the hot water spray. Next the raisins are dumped into a auger feed 22 which is of the type well known to those skilled in the art, which is a spiral type apparatus which pushes the raisins sideways into a delivery chute 24. Here the raisins are then fed through the separating processor as will herein after be explained in accordance with this invention.
The good raisins are then fed onto a bottom trough 26, which also has a feed auger therein which forces the good raisins received from the bottom of the processing equipment and places them on a return chute 28 whereby they are then sent to the packing line.
Raisins while are affected by mold are then fed from a chute 30 into a receptacle or bin 32 whereby the undesirable collection can be disposed in a suitable manner.
Referring now to FIG. 2, there is shown a cylinder 34, which may be comprised of an elongated stretch of matters, not shown, which will keep the cylinder 34 in a substantially circular elongated construction. The cylinder 34 is mounted on a suitable mounting structure 36, as shown in FIG. 3, whereby an angular relationship of the cylinder 34 is provided so that raisins provided to the input chute 24 by the rotating auger 22, will be fed onto the bottom of the screened cylinder 34.
A pair of tracks 40 and 42 are provided on the outside circumference of the cylinder 34, and encircle the entire outside periphery of the cylinder 34, and are held intact in a suitable manner, specifically such as by the use of the ribs 42. A rotating wheel 44, is provided on two ends of the shaft 46 and driven by a drive motor 48. The drive wheels 44 and 45 are in contact with the tract 40 and as the wheels 44 and 45 rotate, they cause the entire cylinder 34 to rotate accordingly. The shaft 46 is secure to the frame 36 by the journals 50 and 52 which includes bearings therein so that the shaft 46 will rotate therewith.
Stabilizing wheels 54 and 56 are connected by means of the bracket 60 and axial 62 which are placed against a top rib of the tract 40 to, in effect, secure the rotating cylinder 34 thereon, so that, as the rotating cylinder rotates on its axis it will bear against the wheel 54, preventing the forward movement of the cylinder 34. As can be seen, the rotating cylinder 34 more or less is cradled on the four wheels 44, on the bottom half thereof and on wheels 45 on the top half thereof and rotated thereby. The cylinder 34 is held in its angular position, that is, from moving forward, by bearing against the outer periphery of the wheel 44 and 45, by the stabilizing wheels 54 and 56.
Within the cylinder 34, there are a plurality of spaced ribs or shelves 64 which are connected to the inside of the cylinder 34 and extend inwardly towards the center thereof. Each shelf 64 is connected to an angle iron 66 extending the entire inside length of the cylinder 34, thus, as raisins are fed onto the chute 34 and into the bottom of the cylinder 34, raisins are trapped by the shelves or ribs 64 and lifted upwardly until the shelves 64 reach a level. Thereafter the raisins will drop from the top of the cylinder 34 to the bottom and are actually propelled thereagainst. Those raisins which have a hard and somewhat firm skin will again be lifted by the shelves 64 and again propelled towards the bottom. Those raisins which are spoiled due to mold and softened by the hot water of the overhead sprays at station 16 and 18 of FIG. 1 will become stuck and lodged to the screen material wrapped around the cylinder 34. Thus, as the cylinder 34 rotates the raisins are actually lifted a number of times and if the length of the cylinder is sufficient, and the speed is controlled, it has been found that a 12 foot long cylinder will actually lift the raisins approximately 12 times and hurl them towards the bottom of the cylinder, that is, once for every foot.
The good raisins are then dropped out the chute 30, and moved by the auger 33, as best shown in FIG. 2, and placed on the conveyor belt 28, to the packing line.
The next step used herein is to remove the bad raisins from the screen. This is accomplished by the use of a chute 31 which extends the entire distance of the inside of cylinder 34 and positioned to the left of center as dictated by the direction of rotation of cylinder 34. A back plate 68 is connected or positioned substantially near one side of the cylinder and specifically the side closer to the center line and angularly disposed along the entire length of the cylinder 34. A pipe 70 extends along the outside of the entire cylinder 34, and positioned at a location directly in alignment with the chute 31 and back pleate 68. Disposed along the pipe 70, is a plurality of spaced spray nozzles. Water is fed to the pipe under pressure said through and nozzles. The water spray from the nozzle is directed against the outside of the screen and washes the raisins that are stuck thereto against the back plate 62 and into the chute 31. It may be desirous that water or some other means is used at the top of the chute 30 as provided by the pipe 72 to literally wash the bad raisins down the chute and into the bin 32 whereby they can be carted away and discarded.
It may be desirous to provide a second pipe 76 inside of the screened cylinder 34, which also has a plurality of spray nozzles thereon and will spray against the inside of the screen. This spray nozzle may be positioned in the lower right hand corner of the screened cylinder 34, dictated by the direction of rotation thereof which is used to cause the molded raisins to adhere to the screen so that they will not drop off from the shelves 64 as they are lifted. | Herein described is a machine for removing raisins spoiled by mold from good raisins. An angularly disposed rotating screened cylinder causes raisins to be lifted and dropped to the bottom of the cylinder. Because of the fact that the bad raisins are soft and sticky they will stick to the screen. Good raisins will be tumbled towards the bottom of the screened cylinder and out. Spray nozzles force water through the screened cylinder washing the stuck raisins into a trough where they are kept separate from the good raisins. | 8 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates generally to the field of trusses used to support a variety of appliances, such as lights. More specifically, a connector is disclosed for connecting together adjacent trusses.
[0003] 2. Description of the Prior Art
[0004] Trusses typically have fixed lengths which may be of insufficient length to span the required distance. As a result, a multiple trusses are aligned to extend over the particular span. The trusses are connected together such as disclosed in U.S. Pat. No. 8,028,488 wherein identical trusses are connected together at their adjacent ends by mating flanges and removable pins extending through the flanges. Such technique requires the adjacent trusses to be aligned to enable the pins to extend through the end flanges of one truss and the end flanges of the adjacent truss. As a result, time and effort is required to first align the trusses and then hold the trusses in alignment while the removable pins are inserted into the flanges. Disclosed herein is a new connector to be used to connect adjacent trusses which may or may not be in perfect alignment.
SUMMARY OF THE INVENTION
[0005] A connector for connecting a first truss having a tube with a first hollow end to a second truss having a second hollow end. A flanged shank is removably insertable in the tube and has a flange to connect to a flanged end of the second truss thereby connecting the first truss to the second truss. The flanged shank of the first truss may be positioned manually adjacent the flanged end of the second truss.
[0006] It is an object of the present invention to provide a coupling allowing easy connection of adjacent trusses that may or may not be in perfect alignment.
[0007] It is a further object of the present invention is to provide a coupling that may be installed on trusses to allow for a quick connection between trusses.
[0008] Related objects and advantages of the present invention will be apparent from the following description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a side view of a pair of prior art trusses.
[0010] FIG. 2 is a top view thereof.
[0011] FIG. 3A is an exploded perspective view of the preferred embodiment of the male connector incorporating the present invention to secure adjacent trusses together.
[0012] FIG. 3B is a perspective view of the assembled connector of FIG. 3A showing the male flange extending in the vertical direction.
[0013] FIG. 3C is the same view as FIG. 3B only with the flange extending in the horizontal direction.
[0014] FIG. 4A is an exploded perspective view of the preferred embodiment, slidable fork-end female connector.
[0015] FIG. 4B is a perspective view of the connector of FIG. 4A only in the assembled position with the female fork-end extending in the vertical direction and located in an inward position.
[0016] FIG. 4C is the same view as FIG. 4B only showing the female fork-end in an extended position and with the fork-end.
[0017] FIG. 4D is the same view as FIG. 4C only showing the extended female fork-end rotated so that the fork-end extends in the horizontal direction.
[0018] FIG. 5 is a fragmentary, enlarged, cross-sectional view of the end of truss tube 23 showing receiver 72 inserted therein and female fork-end 71 inserted into receiver 72 .
[0019] FIG. 6 is a fragmentary, enlarged, cross-sectional view of the end of truss tube 33 showing receiver 52 inserted therein and male fork-end 51 inserted into receiver 52 .
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0020] For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated device, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates.
[0021] FIGS. 1 and 2 show respectively a side and top view of a pair 19 of prior art identical trusses 20 and 21 securable together. Truss 20 will now be described it being understood that an identical description applies to truss 21 . Truss 20 includes four horizontally extending tubular members connected together. In the top view of FIG. 2 , the horizontally extending members include members 22 and 23 joined together by a plurality of cross-members 24 perpendicularly arranged and having their opposite ends fixedly attached to tubes 22 and 23 . A centrally located horizontally extending tube 25 is parallel to tubes 22 and 23 being joined to cross members 24 . Tubes 22 and 23 along with the cross members 24 and central member 25 form a generally rectangular top frame which is replicated on the bottom of the truss and is identical thereto. In the side view of FIG. 1 , the bottom frame is formed by a pair of horizontally extending tubes one of which is shown as member 26 . The two spaced apart bottom horizontally extending members 26 are fixedly secured to the horizontally extending top members 22 and 23 by a plurality of vertical members 27 and a plurality of angular members 28 . Thus, in FIG. 1 , the two bottom horizontal members 26 are joined to the top horizontal member 23 and 24 by members 27 and 28 .
[0022] Mounted to the opposite ends of the four horizontally extending tubes are flanges to enable one truss to be connected to an adjacent truss. For example, identical prior art connectors 29 and 30 are fixedly secured respectively to tubes 22 and 23 and also to the two bottom tubes 26 with each connector having a pair of spaced apart flanges forming a gap. For example, connector 30 has a pair of flanges 32 and 34 spaced apart to receive the single flange 35 fixedly mounted to the end of horizontally extending member 33 of truss 21 . Likewise, a flange identical to flange 35 is provided on each of the horizontally extending tubes of truss 21 to extend into the gap of the adjacent connectors of truss 20 . The flanges of each truss are provided with an aperture through which a removable pin extends to connect the trusses together. For example, connector 30 has an aperture 39 extending through flanges 32 and 34 that is alienable with aperture 36 extending through the single flange 35 . In a similar manner, the adjacent ends of the horizontally extending tubes of members 20 and 21 are connected together. Such a construction is well known in the industry and forms a part of the prior art.
[0023] FIGS. 3 a - c and 4 a - d disclose connectors incorporating the present invention that replace connectors 29 and 30 and flanges 35 . The connectors of FIGS. 3 and 4 are adjustable and allow for easy connection of adjacent trusses. Such adjustment can be accomplished in the field when the truss is in any position including a lowered position or an elevated position. FIG. 5 illustrates connector 70 mounted to truss 20 whereas FIG. 6 illustrates connector 50 mounted to truss 21 .
[0024] FIG. 3A illustrates an exploded perspective view of connector 50 consisting of a cylindrical tubular receiver 52 into which the shank of the male fork-end 51 is inserted. Fork-end 51 has a cylindrical main body or shank 53 insertable into the hollow interior 54 of receiver 52 with the opposite end of the main body including a single flange 62 having an aperture 56 through which a removable pin may be inserted. Holes 57 extend through the cylindrical main body 53 and are alienable with holes 58 or 59 . In the event flange 62 extends vertically ( FIG. 3B ) and hole 56 extends horizontally, then holes 57 are aligned with holes 58 whereas if flange 62 extends horizontally ( FIG. 3C ) and hole 56 extends vertically then holes 57 are aligned with holes 59 with set screws 60 extending freely through holes 58 or 59 as the set screws are threaded through holes 57 . Thus the flange of the fork-end can extend either horizontal or vertical depending upon the orientation of the gap formed by a pair of spaced apart flanges mounted to the end of an adjacent truss. Holes 61 extend through receiver 52 and are alienable with holes provided in one end of the horizontally extending tubes 33 of truss 21 with set screws 91 ( FIG. 6 ) being provided to secure the receiver fixedly to the horizontally extending tubes.
[0025] Once male fork-end 51 is inserted in receiver 52 , the flange 62 can be manually rotated to extend either vertically as shown in FIG. 3B or horizontal as shown in FIG. 3C . The set screws are then installed securing fork-end 51 to the receiver. An enlarged washer shaped portion 55 is provided on flange 62 providing a stop surface 64 abutable against the end 65 of the receiver. Holes 58 , 59 and 61 extend through the opposite side walls of receiver 52 . The connector shown in FIGS. 3A-3C thereby provides a 90 degree rotatable male fork-end. Receiver 52 is then inserted into the end of one of the horizontally extending tubes 33 ( FIG. 6 ) of truss 21 with set screws 91 extending threadedly through tubes 33 and freely through holes 61 provided in receiver 52 .
[0026] FIGS. 4A-4D disclose a telescopic sliding female fork-end that has the flanges rotatable through 90 degrees. An exploded view of connector 70 has a tubular receiver 72 into which the shank 73 of the female fork-end 71 extends. Fork-end 71 has a cylindrical main body slidable into the hollow interior 74 of receiver 72 . Mounted to the end of main body 73 is the fork-end configuration 75 formed by a pair of spaced apart flanges 76 and 77 forming a gap 78 into which flange 62 of connector 50 is extendable. In the event connector 50 is not utilized then connector 70 may be used to receive the fixed single flange 35 of the prior art connectors depicted in FIG. 1 . In either case, a hole 79 extends through flanges 76 and 77 to receive a removable pin which also extends through an aperture in the single flange 62 or 35 mounted to the adjacent truss. A slot 80 extends through main body 73 and is oriented to extend in the direction of the lengthwise extending longitudinal axis of main body 73 . Set screws 81 ( FIG. 4B ) are threadedly received by internally threaded apertures 84 or 85 that extend through the side walls of the main body of receiver 72 . The set screws extend freely through slot 80 allowing the fork-end 71 to move in telescopic fashion. For example, stop surface 82 of fork-end configuration 75 abuts the outwardly facing edge 83 of receiver 72 when the fork-end 71 is in a non-extended position relative to the receiver illustrated in FIG. 4 b . Fork-end 71 may also be extended so that surface 82 is spaced apart from edge 83 thereby allowing for a different spacing between opposite ends of adjacent trusses.
[0027] As with the case of the connector 50 shown in FIG. 3 , connector 70 has a second pair of internally threaded holes 85 ( FIG. 4A ) that extend through the opposite side walls of receiver 72 to threadedly receive the set screws 81 when the flanges 76 and 79 extend horizontally providing a horizontally extending gap 78 .
[0028] A pair of internally threaded holes 86 extend through the opposite side walls of the receiver and threadedly receive a pair of set screws extending freely through holes provided at the end of the horizontally extending tubes 22 , 23 and 26 of truss 20 . Thus, connector 70 has multiple positions. In the first position, the sliding female fork-end is in a retracted position so that surface 82 abuts edge 83 with the flanges being rotated to either a vertical or horizontal position depending upon whether the gap between the flanges is to extend vertically or horizontally. When the fork-end 71 is extended ( FIGS. 4C and 4D ), the flanges can also be positioned to either extend vertically ( FIG. 4C ) or horizontally ( FIG. 4D ). Holes 86 extend through receiver 72 and are alienable with holes provided in one end of the horizontally extending tubes 22 , 23 , 26 of truss 20 with set screws 90 ( FIG. 5 ) securing the receiver fixedly to the horizontally extending tubes.
[0029] While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiment has been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected. | An adjustable fork connector to connect adjacent trusses. A hollow tube is mountable to the end of a first truss and has a pair of spaced apart flanges to extend vertically or horizontally. The flanges are longitudinally movable to position the flanges a selected distance outward from the first truss. A single flange is rotatably mounted to the second truss and is extendable between the pair of flanges and removably connected thereto. | 4 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to German Patent Application No. 10 2011 106 951.1, filed Jul. 8, 2011, which is incorporated herein by reference in its entirety.
TECHNICAL FIELD
[0002] The technical field relates to a motor vehicle body, namely to the motor vehicle bodywork specifically in the region of the ends of a sill extending under a door opening of the body.
BACKGROUND
[0003] A motor vehicle bodywork specifically in the region of the ends of a sill extending under a door opening of the body is conventionally closed off at the face end by a sill bulkhead at an end facing the front or rear wheel housing of the body. This is to form a hollow space in the interior of the sill that protects against the entry of rainwater or splash water from the wheel housing. A motor vehicle body having such a sill bulkhead is known for example from DE 10 2007 015 394 A1 and DE 2008 049 758 A1.
[0004] At its ends, the sill is conventionally connected to a fender of the body extending above it. A connection of sill and fender by means of screws requires as a prerequisite the presence of openings on the sill, through which the screws can extend; so as not to impair the tightness of the hollow space, these screws are arranged beyond the sill bulkhead. In order to ensure that fender and sill are not twisted relative to one another because of internal stresses and in order to ensure a uniform joint appearance between the two, at least two screws are used for the attachment of which is time consuming
[0005] At least one object herein therefore is to create a body structure which makes possible a quick and economical assembly. In addition, other objects, desirable features and characteristics will become apparent from the subsequent summary and detailed description, and the appended claims, taken in conjunction with the accompanying drawings and this background.
SUMMARY
[0006] In an exemplary embodiment, a motor vehicle body having a sill extending below a door opening is provided. A fender is fastened to the sill and a sill bulkhead closes off an inner hollow space of the sill at the face end. A first fastening point for the fastening of the fender to the sill bulkhead is formed.
[0007] For fastening together, the sill and the fender practically comprise surface regions located opposite each other. The first fastening point can then practically comprise a protrusion engaging through an opening of the surface region of the sill into an opening of the surface region of the fender. It is therefore sufficient for an at least provisional assembly of the fender, to place the latter onto the protrusion of the sill bulkhead.
[0008] If the openings are provided in a top side of the sill and a fastening flange is angled off a lower edge of the fender, the fender is at least provisionally held on the protrusion through its own weight.
[0009] In an embodiment, the cross sections of the protrusion and the opening of the fender are matched to each other so that the fender is fixed on the sill through the engagement of the protrusion in at least one direction that is parallel to the mentioned surface regions.
[0010] The protrusion can be formed unitarily with the sill bulkhead; in order to assemble the sill bulkhead, it can be introduced into the sill via an open inner side, the protrusion introduced into the opening of the sill and then the sill bulkhead pivoted into an upright position about an axis that is substantially oriented in a vehicle transverse direction. However, it is also conceivable to design the sill bulkhead and protrusion in two parts and to attach the protrusion on the sill bulkhead through the opening of the sill only after the pivoting of the sill bulkhead into the upright position.
[0011] If the protrusion is connected to the flange via a preferentially shearable pin, the latter can prevent through shearing off the transmission of a deformation between fender and sill in the event of an accident, and by fixing a new protrusion with a new pin, the prerequisites for a renewed fastening of the repaired or replaced fender can be created in a simple and cost-effective manner.
[0012] In that the surface region of the fender rests on a step of the protrusion, the width of a joint between the sill and the fender can be adjusted in a simple exactly reproducible manner.
[0013] A tip of the protrusion protruding over the step, which engages in the opening of the fender, can guarantee fixing of the fender with respect to the sill at least in a direction that is parallel to the surface regions.
[0014] With the help of fingers of the tip that can spread apart, fixing of the fender is also possible in a direction that is perpendicular to the surface regions.
[0015] Fastening of sill and fender to each other at a second fastening point is desirable in order to ensure that the surface regions of sill and fender located opposite each other cannot rotate against each other about a common surface normal. This second fastening point can comprise in particular a screw connection.
[0016] In an embodiment, the sill bulkhead is not involved in this second fastening point.
[0017] In order to make possible fastening of the sill that is generally approximately U-shaped in cross section also to a bottom side of the sill bulkhead, the sill bulkhead at its bottom side can comprise a hook, which engages through an opening formed on a lower leg of the sill.
[0018] Seen in longitudinal direction of the sill, this opening is preferentially located on a side of the sill bulkhead facing away from the inner hollow space, so as not to impair the tightness of this hollow space.
[0019] Preferentially, the hook acts on an edge of the opening extending in vehicle transverse direction. Thus, the hook can already be brought into engagement at the edge of the opening even when the sill bulkhead within the sill is pivoted into its upright position.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The various embodiments will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and wherein:
[0021] FIG. 1 is a motor vehicle body;
[0022] FIG. 2 is a perspective part view of components of a motor vehicle body according to an exemplary embodiment;
[0023] FIG. 3 is a second perspective view showing the sill and the sill bulkhead of the motor vehicle body, omitting the fender provided for fastening thereto;
[0024] FIG. 4 is a perspective view of the sill bulkhead together with supporting parts of the body, without sill and fender;
[0025] FIG. 5 is a schematic section in a vehicle longitudinal direction through the sill bulkhead and surface regions of the sill and of the fender fastened thereto and located opposite each other;
[0026] FIG. 6 is an expanded sectional representation of the sill, of the sill bulkhead, of a protrusion to be mounted to the sill bulkhead and a pin anchoring the protrusion to the sill bulkhead according to another embodiment; and
[0027] FIG. 7 is a section in a vehicle transverse direction through the parts shown in FIG. 5 and the fender fastened with their help.
DETAILED DESCRIPTION
[0028] The following detailed description is merely exemplary in nature and is not intended to limit the invention or the application and uses of the invention. Furthermore, there is no intention to be bound by any theory presented in the preceding background of the invention or the following detailed description.
[0029] FIG. 1 shows in a lateral view a motor vehicle body. In a manner known per se, a sill 1 extends below doors 2 , 3 between front and rear wheel housings 4 , 5 . About the wheel housings 4 , 5 there extend front and rear fenders 6 , 7 , each of which have a narrow arm 8 fastened with its tip to an end section of the sill 1 .
[0030] FIG. 2 shows the front end section of the sill 1 and the tip of the arm 8 of the front fender 6 fastened thereto and a sill bulkhead 9 , which extends transversely through the inner hollow space of the sill 1 . The sill 1 and the fender 6 are formed of metal sheet cuttings in the usual technical manner. The sill 1 has a U or Ω-like cross section that remains the same or at the most varies slightly in vehicle longitudinal direction with upper and lower legs 11 , 12 which are approximately horizontal or, in the case shown here, slightly rise towards the vehicle interior and diverge at their free ends and a curved intermediate section 13 freely visible on the vehicle outside and connecting the legs 11 , 12 .
[0031] The injection-molded sill bulkhead 9 of plastic has a baseplate 14 that is substantially vertical and oriented in vehicle transverse direction, which is surrounded by a reinforced rim 15 . The sill 1 closely hugs the rim 15 throughout its circumference and a foam material layer that is not visible in FIG. 2 seals any joints between the rim 15 and the sill 1 in a water-tight manner so that a hollow space, which extends beyond sill bulkhead 9 over a large part of the length of the sill 1 , is protected from the entry of water from the sides of the wheel housing 4 . A further sill bulkhead of similar shape that is not shown in the Figures can be provided at the end of the sill 1 facing the rear wheel housing 5 in order to seal off the hollow space also to the back.
[0032] In an upper region of the baseplate 14 , a flange supporting the leg 11 of the sill 1 is formed, here in the shape of a transom 16 protruding on the side of the baseplate 14 adjacent to the wheel housing 4 . The transom 16 carries a protrusion 18 on its top side only partially visible in FIG. 2 , which penetrates an opening (concealed in FIG. 2 ) in the upper leg 11 of the sill 1 and an opening 19 in a fastening flange 17 of the fender 6 angled-off substantially horizontally in an end of the arm 8 of the fender 6 . In that the protrusion 18 contacts the edges of the opening 19 of the fastening flange 17 free of play on three or more points, it fixes the fastening flange 17 at least in directions that are parallel to its surface. In order to prevent a movement of the fastening flange 17 perpendicularly to its surface and a rotation about a rotary axis possibly defined through the engagement of the protrusion 18 in the opening 19 , a screw 20 is screwed into a threaded clamp 21 anchored on a second opening of the leg 11 through a second opening of the fastening flange 17 .
[0033] In the edge region of the lower leg 12 angled off towards the outside, an opening 22 is cut, through which a hook 23 that is unitary with the baseplate 14 , extends.
[0034] FIG. 3 shows a view from a similar perspective as FIG. 2 , wherein however the fender 6 has been omitted and the sill 1 is shown transparently in order to be able to more clearly show the sill bulkhead 9 and its protrusion 18 as well as the threaded clamp 21 . The sill bulkhead 9 is elastically clamped between the legs 11 , 12 of the sill 1 , so that the upper leg 11 rests on the transom 16 round about the opening already mentioned above, designated 24 here. The protrusion 18 engages through the opening 24 with little play in vehicle transverse direction, so that the position of the sill 1 in vehicle transverse direction and in the vertical is substantially fixed via the anchorage of the sill bulkhead 9 on the side wall 10 .
[0035] The protrusion 18 is divided into a compact block 25 , whose base area in this case approximately has the shape of a rectangle with rounded-off corners, and whose flanks in contact with the edges of the opening 24 fix the position of the sill 1 and a tip 27 rising above a top side 26 of the block 25 , the engagement of which in the opening 22 (not visible in FIG. 3 ) fixes the fender 6 relative to the sill 1 .
[0036] The tip 27 in this case consists of a central pin 28 and a plurality of fingers 29 grouped round about the pin 28 , the function of which will still be discussed later on.
[0037] The threaded clamp 21 comprises a rectangular baseplate 31 resting on the leg 11 via an opening 30 cut out therein, from the narrow sides of which four fingers 32 are folded back over the baseplate 31 , in order to delimit a through-hole 33 for the screw 20 in each case to a part of its circumference. In that the fingers 32 are axially deflected by the thread of the screw 20 , they form a thread turn that is complementary to the thread, which holds the screw 20 . Legs 34 angled off the wide sides of the baseplate 31 extend through the opening 30 into the interior of the sill 1 and fix the tip of the screw 20 between its distal ends facing each other. Tongues 35 cut clear and spread apart from the legs 34 contact a bottom side of the leg 11 with their distal ends, thus securing the threaded clamp 21 to the sill 1 .
[0038] FIG. 4 shows the sill bulkhead 9 and the sidewall 10 without sill 1 and fender 6 . This representation does not correspond to any intermediate stage during the assembly of the body, since in fact the sill bulkhead 9 and the sidewall 10 are only indirectly connected to each other via the sill 1 . The protrusion 18 and the pin 28 fixing it are visible once mounted on the transom 16 and once in expanded representation, separated from the latter. For as long as the protrusion 18 is not mounted onto the transom 16 , it does not aggravate the attachment of the sill bulkhead 9 in the sill 1 . This is performed in that the sill bulkhead with baseplate 14 substantially oriented horizontally is introduced into the sill 1 and then pivoted into vertical orientation about an axis that is substantially oriented in vehicle transverse direction. Through this pivot movement, the hook 23 of the sill bulkhead 9 plunges into the opening 22 in the lower leg 12 of the sill 1 , and an edge section 36 (see FIG. 3 ) of the opening 22 extending in vehicle transverse direction engages into a recess 37 of the hook 23 . Teeth 38 of the hook 23 protruding into the recess 37 are slightly deformed in the process, so that the leg 12 is held on the hook 23 free of play.
[0039] In the position now reached, the opening 24 in the upper leg 11 overlaps with the top side of the transom 16 , so that the protrusion 18 can be mounted within it. This can be performed in that the fingers 29 of the protrusion 18 are initially pushed into the opening 19 of the fastening flange 17 and engaged therein, and the fastening flange 17 is subsequently anchored to the sill 1 by means of the screw 20 and through inserting of the pin 28 through a bore 39 of the protrusion 18 as far as into a bore 42 (see FIG. 5 ) of the transom 16 . In that a foamed-out insert 40 , which is attached in a groove of the sill bulkhead 9 extending alongside the rim 15 , expands while the body is passing through a painting oven, a water-tight connection between the rim 15 and the sill 1 is obtained.
[0040] According to another embodiment shown in FIGS. 6 and 7 , the protrusion 18 on its lower side facing the transom 16 , is provided with engagement hooks 41 round about the bore 39 . When, following the attachment of the sill bulkhead 9 in the sill 1 the protrusion 18 is pressed through the opening of the upper leg 11 against the transom 16 , the engagement hooks 41 engage in an undercut 43 of the bore 42 of the transom, so that the protrusion 18 is seated tightly on the transom 16 , provisionally fixing the sill 1 . Following this, the fender 6 is positioned wherein the opening 19 of its fastening flange 17 is put over the fingers 29 of the protrusion 18 and the fastening flange 17 finally comes to rest on the top side 26 of the block 25 .
[0041] The placement of the pin 28 can be carried out before or after the attachment of the screw 20 . In that the pin 28 is pushed into the bores 39 , 42 of the protrusion 18 and of the transom 16 , both the engagement hooks 41 as well as the fingers 29 are fixed in their position, so that the protrusion 18 can merely come loose from the sill bulkhead 9 through a tearing of the engagement hooks 41 and the profile of the fingers 29 , as is evident in particular in FIG. 7 , also prevents a lifting-off of the fastening flange 17 from the top side 26 .
[0042] The pin 28 consists of a plastic material of moderate shearing strength. Horizontal shearing forces, which can occur during an accident between the fastening flange 17 and the leg 11 of the sill 1 , result in a shearing-off of the pin 28 at the height of the top of the transom 16 and to a tearing-off of the engagement hooks 41 . Because of this, the sill 1 and the fender 6 become moveable relative to each other in vehicle longitudinal direction and can evade or yield to deformation forces, without mutually damaging each other. In order to mount a new sill 1 if applicable, it is then sufficient to replace the protrusion 18 and the pin 28 . Thus, a quick and cost-effective repair is possible.
[0043] While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment, it being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope of the invention as set forth in the appended claims and their legal equivalents. | A motor vehicle body is provided. The motor vehicle body includes a sill extending under a door opening and a fender fastened to the sill. A sill bulkhead seals off an inner hollow space of the sill at a face end and a first fastening point on the sill bulkhead fastens the fender to the sill. | 1 |
PRIORITY INFORMATION
This application claims the benefit of U.S. Provisional Application No. 60/591,058, filed on Jul. 26, 2004.
FIELD OF THE INVENTION
The field of this invention related to surface cementing heads for dropping balls and wiper plugs into a wellbore.
BACKGROUND OF THE INVENTION
In cementing casing or liners the procedure typically involves dropping one or more balls for engagement with a downhole seat sized for that ball to allow pressure buildup to set downhole devices such as external casing packers. After the ball is dropped and the downhole equipment is set, the delivery of the cement occurs in conjunction of delivery of one or more wiper plugs or darts down the casing. These plugs separate mud from cement or clean the inside of the casing.
Typically the ball-dropping device is located below the dart-releasing device so that the darts must travel past the ball-releasing device after it has dropped the balls. One problem with this layout is that the ball dropping device, after release of the ball, presents either a large opening or edges that can engage the trailing cups on the dart as it is pumped by. What has happened is that tears can develop in these cups allowing fluid bypass around the dart. This can stop the forward motion of the dart or impede its ability to separate fluids or to clean the inside wall of the casing or tubular as it is forced downhole. Accordingly, as described below with regard to the preferred embodiment, as solution to this problem has been devised to try to minimize the tendency to tear the darts as they pass the ball release device.
In another aspect, a provision is made to prevent the darts from coming back uphole, in the event of a pressure surge. Such darts are retained from traveling above their release mechanism. The release mechanism for the darts features, in the preferred embodiment, individual release barrels for each dart allowing for the darts to be dropped in any order. It further allows observation of what dart is in which barrel without affecting the operation of the other barrels holding other darts. Each barrel is movable between a fully misaligned and fully aligned position with the casing or tubular and can be locked in at least two positions. A handle assembly stays with the dart dropping unit and manipulation of the integrated operating handle acts to defeat the lock and rotate a barrel into an aligned position with the casing for launch of the dart.
U.S. Pat. No. 6,182,752 shows a tool that drops darts by continuing rotation in a fixed direction requiring a predetermined order of dropping once the darts are loaded and no provision for checking which dart is in which barrel after loading.
The above described advantages and other features of the invention will be more readily apparent to those skilled in the art from a review of the description of the preferred embodiment and the claims, which appear below.
SUMMARY OF THE INVENTION
A tool for dropping one or more balls and then one or more darts features a closable ball drop opening that works automatically after the ball release to minimize damage to the subsequently released dart. A retainer keeps the darts from coming back up above the dart launcher in the event of a pressure surge in the well. The dart launcher features a dedicated movable barrel for each dart that can be locked in a fully misaligned and fully aligned position with the casing or tubular. A handle is retained to the dart housing and can be manipulated to defeat the lock and rotate a given barrel. The darts may be inspected in their respective barrels before launch and the launch order is variable.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevation view of the assembly showing the dart dropping housing above the ball dropping housing;
FIG. 2 is a section view of a ball trapped in the dropper before release;
FIG. 3 is the view of FIG. 2 showing the door opened and the ball having been released;
FIG. 4 shows the door to the casing closed before the darts are dropped;
FIG. 5 is the view along line 5 - 5 of FIG. 1 ;
FIG. 6 is the view along line 6 - 6 of FIG. 1 ; and
FIG. 7 is an enlarged view of the dart dropper showing the lock and handle feature.
FIG. 7 a is a view along lines 7 - 7 of FIG. 7 with the handle extended out fully vertically and then rotated into a perpendicular horizontal plane.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1 , the plug or dart dropping housing 10 is mounted above the ball dropping housing 12 . While one of each is illustrated those skilled in the art will appreciate that more than one of each can be used. The housing 12 is shown in greater detail in FIGS. 2-4 . FIG. 4 will be used to describe the components of the housing 12 . A handle 14 is mounted for 360 degree rotation of a cam 16 . The handle 14 is secured by a pin 18 to cam 16 . The casing or tubular 20 has an interior wall 22 . A door 24 has a curved surface 26 designed to approximate the curvature of the interior wall 22 of the casing 20 when in the position shown in FIG. 4 . The cam 16 has a guide rod 28 that extends into the door 24 . A spring 30 surrounds rod 28 to bias the door 24 into a position where curved surface 26 is positioned as close as possible to the interior wall 22 . Door 24 has an upper tapered surface 32 to ease its travel path up the outside wall 34 of the casing 20 when the handle 14 is rotated 180 degrees from the position shown in FIG. 4 . The door 24 moves in tandem with the cam 16 because pin 28 secures the door 24 to the cam 16 .
The operation is best understood by going back to FIG. 2 . There a ball 36 is loaded and retained in a space 37 by an extension 38 of the plug 16 . Note that rod 28 extends into extension 38 for tandem movement. A curved ramp 41 can be seen in the out of contact position from the ball 36 when the handle 14 is pointing left in FIG. 2 . As the handle 14 is rotated, the extension 38 takes rod 28 with it forcing the ramp 32 up the outside wall 34 of the casing 20 and up against the bias of spring 30 that surrounds rod 28 .
The movement of handle 14 180 degrees to the FIG. 3 position takes door 24 away from opening 42 in the casing 20 allowing the curved ramp 41 to push the ball 36 through opening 42 and allow it to fall or be pumped downhole through casing 20 .
After release of ball 36 , the handle 14 is rotated another 180 degrees in either direction to allow door 24 to be again aligned with opening 42 and to allow the spring 30 to bias door 24 so that its curved surface 26 stays as closely aligned as possible with the inner wall 22 . In this position it is selectively locked as shown schematically as 15 in FIG. 4 . What will happen next is that a plug or dart will be dropped from housing 10 . Because the door 24 with its curved surface 26 now sits in actual or near alignment with interior wall 22 , there is a reduced chance of damage to the plug or dart 44 as it clears housing 12 . The dart typically has one or more cups for sealing against the wall 22 of the casing 20 to allow it to be easily pumped down. These cups have caught on openings, sharp edges or ledges presented by the ball droppers of the prior designs and the result has been damage or destruction of the cups on the dart 44 . The assembly described above with door 24 addresses this issue by closing the opening 42 after the ball is released and in a manner that minimizes pinch points that can damage the dart 44 that is subsequently dropped past opening 42 .
FIG. 6 illustrates that housing 10 can have mirror image ball dropping assemblies each having a door 24 that works in the above described manner and closes with surface 26 as nearly flush as possible with the interior surface 22 of the casing 20 so as to minimize subsequent damage to the dart 44 . While reference has been made to a ball 36 those skilled in the art will appreciate that other shapes can be used and that fluid pressure rather than curved ramp 41 can be used to get the ball 36 out.
Referring now to FIGS. 6 and 7 , the details of the dart dropping housing 10 will be explained. Housing 12 has a central bore 45 . For illustrative purposes, there are three barrels 46 , 48 and 50 that are each independently rotatable into or out of alignment with bore 45 and two of which 46 and 48 are shown in FIG. 7 . Each barrel can be locked in either position and features an integral handle assembly that can defeat the lock to facilitate rotation. An open barrier 52 is within the inner wall 22 that continues below as part of the casing 20 , as shown in FIG. 4 . This barrier keeps the darts 44 from going further up beyond housing 10 in the event of a pressure surge in the well. At the same time, because barrier 52 is open, flow can pass through it to allow pumping the dart 44 down the casing 20 . FIG. 5 shows the operating shaft assemblies 54 , 56 and 58 that respectively operate barrels 46 , 48 and 50 . One shaft assembly will be described in detail, as in the preferred embodiment they are all identical. A lower shaft 60 is linked (preferably by meshing gears, not shown) or via arms 61 and 63 for rotation of a barrel such as 46 about an arc 49 as shown in FIG. 5 . Similarly, barrels 48 and 50 are respectively independently rotated about arcs 47 and 51 by their operators 56 and 54 . An upper shaft 62 is keyed to lower shaft 60 at connection 64 . A handle 66 is screwed to bolt 68 in the stowed position. A ball 70 at the lower end of handle 66 keeps the handle within cap 72 after the handle is unthreaded from bolt 68 and lifted away from bolt 68 up to the point where ball 70 is stopped by travel stop 75 . A dog 74 extends into a groove 76 in upper shaft 62 . When the handle 66 is pulled away from bolt 68 until ball 70 stops further outward travel of the handle 66 , the handle 66 is rotated to a position perpendicular to axis 63 while still retained by the shaft 62 to engage the dog 74 to cam it away from groove 76 along mating tapers 78 . While still engaged by shaft 62 , the handle can rotate about axis 63 in an opening 73 , see FIG. 7 a , that is sufficiently wide to allow handle 66 to rotate shaft 62 well under 60 degrees to align or misalign a barrel such as 46 with the central bore 45 . FIG. 7 a has been added to show the handle pulled all the way up along axis 63 and turned to a plane perpendicular to axis 63 and then rotatable in that plane perpendicular to axis 63 to align a barrel in the passage 45 . The bell 70 can be unthreaded from 68 and raised straight up inside shaft 62 along axis 63 . The opening 77 on top of cap 72 is smaller than the receptacle 70 preventing it from coming straight out of shaft 62 along axis 63 . When the handle is fully extended along axis 63 until it hits opening 77 in cap 72 , the handle can be turned 90 degrees into gap 73 in the side of cap 72 . In the position of FIG. 7 a the handle 66 can turn left or right as shown by arrows 79 . Since the top of shaft 62 is also slotted in alignment with slot 73 , the left or right movement 79 of handle 66 will turn shaft 62 and 60 which move in tandem. Handle 66 is not removable from shaft 62 . At this point dog 74 snaps into another groove 76 to lock the barrel 46 in the position of alignment with bore 45 . An indicator 80 of a type known in the art signals the passage of dart 44 out of barrel 46 . The other darts 44 in the other barrels 48 and 50 can then be released in the same way, after barrel 46 is retracted out of alignment with bore 45 .
This arrangement offers advantages over prior dart dropping designs. One is that each barrel can be inspected to be sure there is a dart 44 in it before the cementing procedure starts. The darts 44 can then be dropped in any desired order. The handle 66 that operates an individual barrel cannot be lost as it is made to be retained by the cap 72 . Any of the barrels can be selectively locked in the drop position where there is alignment with bore 45 . The locking is automatic upon rotation into position and dog 74 falling into slot 76 when barrel 46 aligns with bore 45 , for example. By manipulating the handle, after dropping the dart 44 the dog is retracted allowing the reverse movement to occur to fully misalign barrel 46 from bore 45 and lock that position as dog 74 falls into another slot (not shown) on cap 72 . Again the other barrels preferably work in the same manner.
While three barrels in one housing 10 are shown, varying numbers of barrels can be used in each housing. Shafts 60 and 62 can be in one piece and can also be power driven as opposed to manual handle 66 .
Using the combination of equipment described above, one or more objects of the same or different dimensions can be dropped from housing 12 followed by closure of the opening or openings 42 with a door 24 to present a flush or nearly flush surface 26 adjacent the inner wall 22 of the casing 20 . The darts 44 can then be dropped in any order from a given housing 10 with little concern about damage as they pass openings 42 that are covered with a door 24 that is flush or nearly so. If there is a pressure surge as the darts are being dropped, the barrier 52 prevents them from being blown past the housing 10 . The built in handle 66 can't be lost. The barrels 46 , 48 and 50 can be selectively locked in a fully aligned position with bore 45 or in a fully misaligned position or any other desired position. The dog 74 engages a groove such as 76 automatically and can be defeated by permitted movements of the handle 66 within cap 72 .
While the preferred embodiment has been set forth above, those skilled in art will appreciate that the scope of the invention is significantly broader and as outlined in the claims which appear below. | A tool for dropping one or more balls and then one or more darts features a closable ball drop opening that works automatically after the ball release to minimize damage to the subsequently released dart. A retainer keeps the darts from coming back up above the dart launcher in the event of a pressure surge in the well. The dart launcher features a dedicated movable barrel for each dart that can be locked in a fully misaligned and fully aligned position with the casing or tubular. A handle is retained to the dart housing and can be manipulated to defeat the lock and rotate a given barrel. The darts may be inspected in their respective barrels before launch and the launch order is variable. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. patent application Ser. No. 13/720,201, titled “USING TEMPORARY PERFORMANCE OBJECTS FOR ENHANCED QUERY PERFORMANCE” and filed on Dec. 19, 2012, the entire content of which is incorporated herein by reference.
BACKGROUND
The present invention relates to the information management field, and more specifically, to improving processing and optimizing of database queries in a database management system. Databases come in many flavors. One popular form is a relational database management system (RDBMS), such as DB2™ system, which is manufactured by International Business Machines Corporation of Armonk, N.Y.
The RDBMS is responsible for handling all requests for access to the database where the data itself is actually stored, thereby shielding the users from the details of any specific hardware implementation. Using relational techniques, the RDBMS stores, manipulates and retrieves data in the form of table-like relations typically defined by a set of columns or attributes of data types and a set of rows (i.e. records or tuples) of data. The columns may further comprise restrictions on their data content (i.e. valid domains) and may be designated as a primary key or unique identifier for the relation or a foreign key for one or more other relations.
One very common language for dealing with RDBMSs is the Structured Query Language (SQL). SQL includes both data definition operations and data manipulation operations. To maintain data independence a query (i.e. a set of SQL commands) instructs the RDBMS what to do but not how to do it. Thus, the RDBMS includes a query processor for generating various query plans of execution and choosing the least expensive plan with respect to execution costs. Due to the high-level nature of relational expressions and a variety of implementation techniques, automatic query optimization is possible and often necessary to ensure more efficient query processing.
Often, a database application may require the creation of a “view” for the data in given relations or tables. A view provides an alternative way of looking at the data in one or more base tables. It may, for example, contain only selected columns from the table. A materialized query table (MQT) is a table whose definition is based upon the result of a query. The data that is contained in an MQT is derived from one or more tables on which the materialized query table definition is based. One way to think of an MQT is as a kind of materialized view. Both views and MQTs are defined on the basis of a query. The query on which a view is based is run whenever the view is referenced; however, an MQT actually stores the query results as data, and it is possible work with the data that is in the MQT instead of the data that is in the underlying tables.
Materialized query tables can significantly improve the performance of queries, especially complex queries. If the optimizer determines that a query or part of a query could be resolved using an MQT, the query might be rewritten to take advantage of the MQT. Thus, a current dilemma a database query optimizer is faced with regarding query performance is whether to use an existing MQT, or to fetch data directly from the buffer cache (if available) or any other cache/non cache object or perform direct I/O to fetch data from the disks. There are especially no easy solutions if the reporting requirements needs to fetch data from both RDBMS and exogenous unstructured data, such as RSS Feeds, flat files, etc.
Another option is to create a temporary MQT, which can satisfy the query under question. The trade off between the choices of using an existing MQT or temporary MQT may be understood as follows. The existing MQT has no start up time to use it, but using the existing MQT may result in long fetch times because extra I/O's on a table object must typically be performed to determine which records to discard and which to return to the user.
Conversely, the temporary MQT has a start up cost to build, but once built, the fetch time will be faster. The fetch time is faster for a temporary MQT because every record processed in the temporary MQT is one of interest, and thus no time is wasted going to the table object for records that will be discarded immediately. Such decisions need not be made solely based on information internal to the DBMS. External data, such as calendar events, unstructured data (Twitter, Facebook, blogs, etc.) can also be analyzed to predict the likelihood of queries occurring. In a simple example, if weather data indicates the likelihood of a hurricane striking a location, then building stores (e.g., Home Depot) might expect increases in the number of web queries relating to generators available at a particular store sold for less than a given price. The efficiency of answering such queries might be improved by a performance object, such as an MQT. Thus, there is a need for improved mechanisms for processing and optimizing database queries in a database management system.
SUMMARY
According to one embodiment of the present invention, methods are provided for optimizing query performance in a relational database management system. A query is received at the relational database management system. It is determined whether the query is expected to be a long-running query. In response to determining that the query is expected to be a long-running query, a full table scan is started in order to fetch records needed to satisfy the query from the relational database management system. In parallel with conducting the full table scan, a performance object is built, which is capable of satisfying the query in the relational database management system. In response to completing the construction of the performance object prior to completing the full table scan, the full table scan is stopped and the newly built performance object is used instead to satisfy the query.
The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features and advantages of the invention will be apparent from the description and drawings, and from the claims.
DESCRIPTION OF DRAWINGS
FIG. 1 shows a process ( 100 ) for optimizing query performance in accordance with one embodiment.
FIG. 2 shows a task ( 200 ) for building a performance object, which runs in parallel with at least a portion of the process ( 100 ) of FIG. 1 , in accordance with one embodiment.
FIG. 3 shows a switchover from an original query plan used by the process ( 100 ) to a new query plan based on the performance object, in accordance with one embodiment.
FIG. 4 shows a schematic view of two tables ( 400 , 402 ) containing RowIDs retrieved to satisfy the query using the original query plan and the performance object, respectively, in accordance with one embodiment.
Like reference symbols in the various drawings indicate like elements.
DETAILED DESCRIPTION
The various embodiments of the invention provide techniques for improving processing and optimizing of database queries in a RDBMS by combining data from both the database and from exogenous data sources outside the RDBMS. The various embodiments of the invention will be presented below by way of example with respect to MQT. However, it should be realized that the invention is applicable to any type of performance object that can be used to improve the performance of an incoming query. As was described above, performance issues typically arise in complex data scenarios, which include exogenous data sources like social media, RSS feeds, structured files, etc. in addition to including an RDBMS. Thus, the various embodiments of the invention are especially applicable in such scenarios.
In accordance with one embodiment, a temporary MQT is created after taking into consideration various performance implications. Live switchover to the temporary MQT is then implemented for faster query performance and without any negative effect on the currently running queries and/or applications. When no performance enhancement methods like existing MQT, Indexes, Data cached in memory, etc. exists to improve the query under question, then the system can start creating the temporary MQT, since it is confirmed that it must fetch data from the disk using direct I/O.
A first plan using an existing MQT or data cached in buffer pools or other cache locations is used for processing a query. A temporary MQT index is built for the query simultaneously with the first plan processing the query. When the temporary MQT is built, processing the query with the first plan is stopped and a live switchover to the temporary MQT is provided. Then a second query plan using the temporary MQT is used to continue processing the query at a point where processing stopped with the first query plan.
As will be appreciated by one skilled in the art, aspects of the present invention may be embodied as a system, method or computer program product. Accordingly, aspects of the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, micro-code, etc.) or an embodiment combining software and hardware aspects that may all generally be referred to herein as a “circuit,” “module” or “system.” Furthermore, aspects of the present invention may take the form of a computer program product embodied in one or more computer readable medium(s) having computer readable program code embodied thereon.
Any combination of one or more computer readable medium(s) may be utilized. The computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer readable storage medium may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples (a non-exhaustive list) of the computer readable storage medium would include the following: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the context of this document, a computer readable storage medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device.
A computer readable signal medium may include a propagated data signal with computer readable program code embodied therein, for example, in baseband or as part of a carrier wave. Such a propagated signal may take any of a variety of forms, including, but not limited to, electro-magnetic, optical, or any suitable combination thereof. A computer readable signal medium may be any computer readable medium that is not a computer readable storage medium and that can communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device.
Program code embodied on a computer readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.
Computer program code for carrying out operations for aspects of the present invention may be written in any combination of one or more programming languages, including an object oriented programming language such as Java, Smalltalk, C++ or the like and conventional procedural programming languages, such as the “C” programming language or similar programming languages. The program code may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider).
Aspects of the present invention are described below with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer readable medium that can direct a computer, other programmable data processing apparatus, or other devices to function in a particular manner, such that the instructions stored in the computer readable medium produce an article of manufacture including instructions which implement the function/act specified in the flowchart and/or block diagram block or blocks.
The computer program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other devices to cause a series of operational steps to be performed on the computer, other programmable apparatus or other devices to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide processes for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.
The various embodiments of the invention will now be described by way of example and with reference to the drawings. In accordance with one embodiment, when it is not clear whether using an existing MQT or cached data or index or any other performance enhancing methods or creating a temporary MQT will provide the greatest query efficiency, the query optimizer starts running the query using the “best of the lot” access plan, while in the background and in parallel, simultaneously building a temporary MQT for the query. If the query finishes before the temporary MQT is built, the temporary MQT build is terminated. However, when the temporary MQT is built before the query finishes, a live switchover to the temporary MQT will be done and the query will continue at the point it left off at using the existing access plan.
FIG. 1 shows a process ( 100 ) in accordance with one embodiment for optimizing query performance. As can be seen in FIG. 1 , the process starts by receiving an incoming Query (Q 1 ) at the RDBMS server (step 102 ). In some embodiments, the query (Q 1 ) may need to use RDBMS sources, as well as “non-RDBMS sources”, also referred to herein as exogenous sources, to satisfy the query (Q 1 ). Thus, it may be necessary to also analyze exogenous data. Mechanisms for performing such analysis are generally known to those of ordinary skill in the art, and will vary depending on the specific type of exogenous source. For example, various methods for analyzing streams on Twitter can be found at http://socialmediatoday.com/index.php?q=SMC/80437.
Next, it is determined if the received query (Q 1 ) is projected to be long running (step 104 ). This can be determined, for example, by comparing the estimated time required to satisfy the query with a threshold value. The threshold can either be user-defined or be set automatically by the system using known techniques for setting threshold values.
If it is determined in step 104 that the query (Q 1 ) is not projected to be long running, then the process ends. If it is determined that the query is projected to be long-running, then the process continues to determine whether the query will be best run with an MQT (step 106 ). In making this determination, typically both local and exogenous factors are considered. Some examples of local factors include local system resource usage, such as CPU, RAM, I/O, etc. Examples of exogenous factors include network latency accessing a shared file on a shared device, the speed of an Internet connection (e.g., while opening a Facebook account), etc.
If it is determined in step 106 that the query (Q 1 ) will not be best run with an MQT, then the process ends. If it is determined that the query will benefit from being run with an MQT, then the process continues to determine whether the machine on which the query is run has sufficient resources, such as memory, processor speed, etc., to build a temporary MQT without negatively affecting the current running queries or applications (step 108 ). In one embodiment, the determination can be made using existing RDBMS Optimizers, possibly along with non-RDBMS tools, which have the capability to determine the minimum amount of resources needed to build a performance object. These tools take into consideration the current resource utilization and the resources requirement to create and populate a performance object, such as an MQT.
If it is determined in step 108 that there are not sufficient machine resources, then the process ends. If it is determined that there are enough machine resources, then the process continues to determine whether there are any existing methods for improving the current query (step 110 ). Some examples of methods that can be used to improve the query include using an existing MQT, caching data in buffer pools, creating indexes, etc.
If it is determined in step 110 that there are no available methods for improving the query, then the process ends. If it is determined that there are methods for improving the query, then the process continues to determine and build an access plan (A 1 ) using the “best of the lot” methods (step 112 ). In addition, the process spawns a task (T 1 ) to start building alternate performance objects, such as creating a temporary MQT or continuing to populate an existing MQT if one has already been created. This task runs in parallel with the rest of the steps of the process, but will be explained with reference to FIG. 2 , in order not to unnecessarily complicate the explanation of the invention.
Next, the process starts fetching the resultant records (R 1 ) as dictated by the query plan (A 1 ) (step 114 ). The fetching of the records continues until it is determined in step 116 that the query (Q 1 ) is fully executed, at which point the process ends.
Turning now to the parallel process ( 200 ) for building an alternate performance object, shown in FIG. 2 , the parallel process ( 200 ) starts by building a performance object (P 1 ) (step 202 ), such as a temporary MQT. The process monitors the execution of the query (Q 1 ) by the query plan (A 1 ) to determine whether the query is done (step 204 ). If the query is not done, the process checks if the performance object has been completed (step 206 ). If the performance object has not been completed, then the process returns to step 202 and continues building the performance object.
When it is determined in step 204 that the query is done, then there is no need to continue building the performance object, so the building of the performance object is stopped (step 208 ) and the performance object is discarded (step 210 ), which ends the process ( 200 ).
Returning now to step 206 , if it is determined that the building of the performance object has been completed, the process again checks whether the query has been completed (step 212 ). If the query is done, then the performance object is discarded (step 210 ) as it will not be needed, which ends the process ( 200 ).
If it is determined in step 212 that the query is still executing in accordance with the query plan (A 1 ), then the execution of the query plan (A 1 ) will stop and the newly built temporary performance object, such as an MQT will be used instead. The details of this will now be described with reference to FIGS. 3 and 4 .
As can be seen in FIG. 3 , when the query execution plan (A 1 ) is still running and the performance object has been built, then the execution of the query execution plan is stopped and the position in the tables for the last row fetched is held (step 302 ). The process then migrates to a new query plan that uses the performance object (P 1 ) (step 304 ). After migrating to the new query plan, the process continues fetching the remaining records for the query (Q 1 ) using the performance object (i.e., the temporary MQT) (step 306 ) until the query is satisfied. At that point, the final result is returned to the user (step 308 ) and the process ends.
In some embodiments, the created performance object can be stored in storage or memory for a certain time, for example, until it exceeds a threshold age value, which can either be set by a user, or by the system using any known techniques, such as a FIFO queue or a data stack.
FIG. 4 shows a schematic example of what the query result tables might look like, in accordance to one embodiment of the invention. The table ( 400 ) on the left hand side of FIG. 4 shows a set of RowIDs of records fetched for two tables, Table A and Table B, respectively. The upper section ( 404 ) of the table ( 400 ) shows the RowIDs that have been fetched using a full table scan or some “lower performing” option, when trying to satisfy the query. The table on the right hand side shows a performance object in the form of an MQT ( 402 ), which contains not only the RowIDs for Table A and Table B, but also the column data needed for the query for Table A and Table B, respectively. This MQT ( 402 ) is built by the parallel process ( 200 ) described above with respect to FIG. 2 .
FIG. 4 also shows the point of migration from the old query plan to the new query plan, described above with respect to step 304 of FIG. 3 . The last row retrieved from the main query using the old query plan is the one with RowID “igf09820987” for Table A and “kgf09820830” for Table B, as shown in the left hand side table ( 400 ). This corresponds to the hold position described above with respect to FIG. 3 . The rest of the query is satisfied using the MQT ( 402 ), starting at the row having RowID “Bgf09823333” for Table A and “Bnmggf0982083” for Table B, and going through the end of the MQT ( 402 ). Retrieving the remaining rows from the MQT ( 402 ) is faster compared to having to do a full table scan or another low-performing option from Table A and Table B, respectively.
It should be noted that while the performance object has been discussed above with respect to an MQT, the same general principles can be applied to any type of internal or external database object that might enhance the performance and lead to faster processing of the query. A non-exclusive list of other examples of performance objects includes MDC (i.e., a Multi-dimensional clustered table, which is a DB2 performance object), Indexes, Temporary tables, etc. By having the performance object in memory, the I/O overhead can be reduced, and once the initial investment of creating the performance object has been made, it can often help not only existing queries, but also future ones.
The flowchart and block diagrams in the Figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems that perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. 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” and/or “comprising,” 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.
The corresponding structures, materials, acts, and equivalents of all means or step plus function elements in the claims below are intended to include any structure, material, or act for performing the function in combination with other claimed elements as specifically claimed. The description of the present invention has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the invention. The embodiment was chosen and described in order to best explain the principles of the invention and the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated. | Methods for optimizing query performance in a relational database management system. A query is received at the relational database management system. It is determined whether the query is expected to be a long-running query. In response to determining that the query is expected to be a long-running query, a full table scan is started in order to fetch records needed to satisfy the query from the relational database management system. In parallel with conducting the full table scan, a performance object is built, which is capable of satisfying the query in the relational database management system. In response to completing the construction of the performance object prior to completing the full table scan, the full table scan is stopped and the newly built performance object is used instead to satisfy the query. | 6 |
FIELD OF THE INVENTION
The present invention relates to a rotary cutting head for gas or electric powered trimmers and the cutting elements for such trimmers.
BACKGROUND OF THE INVENTION
In recent years, gas or electric powered lawn trimmers have become increasingly popular. Typically, the lawn trimmer will comprise a cutting head operatively associated with a rotating shaft driven by the gas or electric powered motor. Several fishing line cutting elements are secured to the perimeter of the cutting head whereby selective rotation of the cutting head causes the fishing line to flail outwardly and cut or trim the grass as it contacts it.
Although lawn trimmers employing flexible fishing line cutting elements work well enough on conventional grass, they have been found to be not entirely satisfactory. For example, certain types of thick or coarse vegetation cannot be effectively cut or trimmed with a fishing line cutting element. Consequently, it has been proposed to use flexible plastic cutting blades for cutting thick grass or woody growth. For the most part, consumers have found it necessary to own two different trimmers, each adapted to cut the different types of vegetation.
In view of the above, it is desirable to interchange the cutting elements of the cutting head in order to adapt the trimmer to the type of vegetation being trimmed. At the present, trimmers do not permit the cutting elements to be readily changed and in many cases, replacement of the entire cutting head is necessary. Tools must be used to open the cutting head and parts are often lost during disassembly and reassembly. As is apparent, the additional work required to change the cutting head elements prolongs an already laborious chore of cutting the grass.
In addition to the above, the fishing line cutting elements found on prior art cutting heads are prone to fraying and must be routinely replaced.
OBJECTS AND SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a lawn trimmer and in particular a cutting head for a lawn trimmer that permits the metal edge plastic flail blades and the molded cutting lines to be quickly changed without the need for tools.
A still further object of the present invention is to provide a latch mechanism for a cutting head that will secure the flail blades or mold lines without the need for screws, nuts or similar attachment means.
A further object of the present invention is to provide a molded cutting line having improved cutting ability and wearability over prior art fishing line cutting elements.
Another object of the present invention is to provide a cutting head that may be readily installed on preexisting electric or gas powered trimmer devices
Yet another object of the present invention is to provide a cutting head having a cover member for protecting the cutting elements and maintaining the interior of the cutting head free of debris.
A still further object of the present invention is to provide metal edge plastic flail blades that are reversible and readably interchangeable.
Yet another object of the present invention is to provide a cutting head having an improved shape; most notably, a rounded bottom edge that reduces the impact of the cutting head against flowers or other fragile material.
Still a further object of the present invention is to provide a single replacement cutting head that performs a range of trimming needs otherwise required by two separate trimming heads; that is, trimming against foundation, fence lines, trees, and thicker grass and woody growth.
In summary, the present invention is directed to a rotatable cutting head for a powered trimmer comprising top and bottom cover members, the bottom member is adapted to be operably associated with the drive shaft of a trimmer and includes at least one pivot member for receiving a pivoting cutting element, a latch mechanism is provided on the top cover for engaging the pivot member when the top and bottom cover members are mated, the latch member is secured against the pivot member by centrifugal forces acting on the latch during operation of the trimmer. The cutting elements comprise blades or molded lines that are readily adapted to be interchanged within the cutting head without the need for tools or complex disassembly.
These and other objects and advantages of the present invention will become apparent from a consideration of the following detailed description taken in conjunction with the accompanying drawings.
DETAILED DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the assembled trimmer head according to the present invention provided with blade cutting elements and shown with the top cover of the cutting head in a locked position;
FIG. 2 is a perspective view of the cutting head as shown in FIG. 1 but with the latch mechanisms in an open position;
FIG. 3 is an partially exploded view of the cutting head shown in FIG. 2;
FIG. 4 is a cross-sectional view of the molded line cutting element and taken along lines 4--4 of FIG. 9;
FIG. 5 is the device shown in FIG. 1 and further including a guard member attached to the drive shaft of the trimmer;
FIG. 6 is a sectional view taken along lines 6--6 of FIG. 1.
FIG. 7 is a cross-sectional view of the cutting head according to the present invention showing the cover disassembled from the base and without attached cutting elements;
FIG. 8 is a bottom plan view of the cutting head cover member;
FIG. 9 is a molded line cutting element according to the present invention; and
FIG. 10 is a cross-sectional view of the molded line cutting element taken along lines 10--10 of FIG. 9 with portions broken away.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The cutting head H according to the present invention is best shown in FIGS. 1 through 3. The cutting head H generally comprises a cover member 2 that interfits with a base member 4 and each or which are shown to have a generally circular configuration.
The base member 4 includes a raised hub portion 6 extending upwardly from bottom surface 8. As best shown in FIG. 6, the base member is operably secured by a bolt 60 or other device to a drive shaft (not shown) within drive shaft housing 58. A series of arms or reinforcement ribs 10 extend radially and outwardly from the hub member 6 to an upwardly curved rim 12 of the base member. The exterior surface of the base member 4 is relatively smooth, having a gentle curved surface extending from the rim 12 to the underside surface 14. Both the base member and the cover member may be constructed from stiff plastic or other material adapted to provide strength and rigidity.
Three cutting element mounts 16, 18, and 20 are shown to extend perpendicular from the surface 8 of the base member. As is apparent, both the number and position of the mounts may vary within the scope of the present invention. In the embodiment shown in FIGS. 1 through 3, three mounts are provided as are cooperating blade-like cutting elements 22 within each of the respective mounts 16, 18 and 20.
A cutter post 24 is positioned within each of the blade mounts 16, 18 and 20 and secured by bolts 26 and a washer 28 in a substantially vertical manner to the plane of base member 4. This is best illustrated in FIGS. 6 and 7. The cutter post 24 shown in FIG. 7 has a central cavity containing female threads adapted to mate with the male threads provided on the bolts 26. As is apparent, other means for securing the cutter post 24 to the base member 4 are within the scope of the invention. For example, the cutter post could be secured by rivets, adhesive or even integral molding within the base member 4. The cutter post includes a head portion 28 and neck portion 30 which will be discussed in further detail below.
Turning again to FIG. 3, the cover member 2 is shown to have a generally circular configuration defined by an outer rim member 32 having substantially the same diameter as rim member 12 of base member 4. An interior rim member 34 is also provided. A series of support ribs 36 extend between the outer rim member and the interior rim member 34 and along the top surface 38 of the cover member 2. The bottom surface 40 of the cover member 2 is best shown in FIG. 8. A series of pivoting latch members 42 are mounted by respective securing devices 44 shown in the figures to comprise a nut and bolt arrangement. As is apparent, other securing devices 44 are within the scope of the present invention. For example, a rivet or other member could be provided.
The securing device 44 attaches the latch member 42 to the top surface 38 of the cover member 2 and in a manner so as to permit pivoting of the latch member 2 about securing device 44 in either direction of arrow 46. As can be seen, the latch member 42 comprises an elongated L-shaped unit provided at a first end with a slot 48. The cover member 2 is provided with apertures 50 extending through the cover member 2 from top surface 38 through bottom surface 40. Each aperture 50 is provided to receive and be substantially aligned with the head portions 28 of the cutter post 24.
As best shown in FIG. 3, the cutting blade 22 includes at a first end thereof a mount 52 provided with an aperture 54 to receive the head portion 28 of cutter post 24 to thereby permit the cutter blade to freely pivot about a vertical axis shown by line 56. Alignment of the cuter post 24 with each of the cutter blades 22 and apertures 50 of the cover member 2 is best shown in FIG. 2 which further illustrates the latch members 42 in an open position. FIG. 1 illustrates the latch members in a closed or locked position whereby the respective slot members 48 for each of the latch members 42 are engaged against the cutter post 24 and in particular the respective neck portions 30. This is best shown in FIG. 6 which illustrates the alignment between cover member 2 and base member 4 and where the cutter post 24 is shown extending through the aperture 50 of the cover member 2 and aperture 54 of the cutter blade with the slot member 48 of the latch 42 positioned against the neck portion 30 of cutter post 24. The interior rim member 34 of the cover member 2 lies flush against the surface of the hub member 6 of base member 4.
As shown in FIG. 5, the drive shaft housing 58 of the hand held trimmer is operably associated with a drive shaft (not shown) positioned to rotate within the housing 58. The drive shaft is secured by an appropriate nut and bolt means 60 and in a manner that will permit the cutting head H to be rotated by the drive shaft. As shown in FIG. 5, a guard 62 may be provided and secured to the drive shaft housing 58 to prevent debris from injuring an operator during use of the device.
During use, rotation of the drive shaft will cause the cutting head H likewise rotate at a high rate of speed. The centrifugal forces acting upon the cutting head causes the pivoting latch members 42 to be urged outwardly from the open position shown in FIG. 2 into a closed or locked position shown in FIG. 1. Thus, no manual locking is required to hold the latch member in place during use.
The centrifugal forces also cause each of the cutter blades 22 to pivot outwardly and thereby cut grass, vegetation or other material from around and under a fence, shrubbery or various other articles. The free pivot arrangement of the mount 52 for the cutter blade within the cutting head H also minimizes damage to the blades in the event the blades strike a non-moveable object such as a rock fence post or the like. In that instance, the cutting blade will be forced backwards away from the immovable object and thereby cushion the blow against the blade. The use of the cutter post 24 for mounting of the blades thereby provides improved performance of the cutting operation. In addition, a cutting head H comprising both the cover and base member restricts the amount of dirt or other debris which would otherwise function to clog or impair operation of the pivot arrangement. Also, the cover 2 according to the present invention permits an operator to readily access the interior of the cutting head H without the need for tools or complicated latch mechanisms and in turn readily permits the cutting blades 22 to be changed or replaced. All of these features provide a replacement cutting head of improved cutting ability and simplicity of construction.
Turning to FIGS. 4, 9 and 10, an alternative embodiment to the present invention is shown and includes a molded cutting line which may be used in place of the cutting blades discussed earlier. The molded cutting line 64 is shown to comprise a self-supporting, elongated, generally planar line portion 66 having a circular cross section. In a preferred embodiment, the thermoplastic or other material used in the construction of the molded cutting lines 64 is rigid enough to allow grass to be cut yet pliable enough to permit the cutting line 66 to flex somewhat when striking an immovable object. The molded cutting line 64 is provided with a mount 68 substantially similar to the mount 52 shown for cutting blade 22 and positioned about the cutter post 24 in the same manner. An aperture 70 extends through mount 68 and provides a free pivot thereof. The cutting blade 22 and molding cutting line 64 together with the cutting head H of the present invention permit an operator to readily interchange the cutting members depending upon the nature of the vegetation to be cut. This greatly increases the utility of the cutting head of the present invention.
While this invention has been described as having a preferred design, it is understood that it is capable of further modifications, and uses and/or adaptations of the invention and following in general the principle of the invention and including such departures from the present disclosure as come within the known or customary practice in the art to which the invention pertains, and as may be applied to the central features hereinbefore set forth, and fall within the scope of the invention or limits of the claims appended hereto. | The present invention is directed to a rotatable cutting head for a powered trimmer comprising top and bottom cover members, the bottom member is adapted to be operably associated with the drive shaft of a trimmer and includes at least one pivot member for receiving a pivoting cutting element, a latch mechanism is provided on the top cover for engaging the pivot member when the top and bottom cover members are mated, the latch member is secured against the pivot member by centrifugal forces acting on the latch during operation of the trimmer. The cutting elements comprise blades or molded lines that are readily adapted to be interchanged within the cutting head without the need for tools or complex disassembly. | 0 |
FIELD OF THE INVENTION
[0001] The present invention relates generally to an image projection system, and more specifically, to a two-dimensional image projection system comprising an array of micromirror array lenses.
BACKGROUND
[0002] Spatial light modulators (SLM) have been used in projection display systems to increase image resolution and display brightness. For example, a Digital Micromirror Device (DMD) array, as described in U.S. Pat. Nos. 5,535,047 and 6,232,936, was used for two-dimensional image projection devices. According to this teaching, each micromirror of the DMD array has single-degree-of-freedom, rotation about an axis, and works as a simple optical switch. Since the DMD array is merely an array of optical switches, the direction of light is limited. As shown in FIG. 1 , the DMD array has only two positions; one is the “on” position and the other is the “off” position. When the DMD array is applied to a two-dimensional image projection device, such as projectors and projection televisions, simple “on-off” behavior limits its light efficiency and becomes the main reason for its high power consumption. According to the prior art, the DMD array uses at most fifty percent (50%) of incident light because it only has “on” or “off” positions. In that regard, the light is dumped when the mirror is at it “off” position. In order to improve brightness and power efficiency of two-dimensional image projection system, most of the reflected light should be projected onto the screen.
[0003] In the prior art, a lens comprising a micromirror array was proposed by Boyd and G. Cho in their paper entitled, “Fast-response Variable Focusing Micromirror Array Lens”, Proc. SPIE, Vol. 5055, 278-286 (2003). Although micromirror array lens is capable of changing its focal length in a very sort amount of time, the micromirror array lens is not capable of being used in two-dimensional display devices because its optical axis is fixed. Moreover, since the micromirror array lens is a reflective type lens with a fixed optical axis, additional optical components, such as beam splitter, are required. The additional optical components deteriorate the light efficiency, and increase complexity and cost of the optical system.
[0004] Thus, there is a practical need for a two-dimensional image projection system that incorporates the advanced focusing capabilities of micromirror array lenses to improve brightness and power efficiency over existing projection systems. It is desired that such system be easy to manufacture and capable of being used with existing two-dimensional projections systems and devices.
SUMMARY OF THE INVENTION
[0005] The present invention is directed to an image projection device for displaying two-dimensional images. The device comprises an array of micromirror array lenses. Each micromirror array lens is comprised of an arbitrary group of micromirrors. The group of micromirrors vary according to the image displayed. The micromirrors are individually controlled electrostatically and/or electromagnetically by actuating components. The micromirrors are provided with three-degree-of-freedom motion; one translational motion along the normal axis to the plane of lens and two rotational motions about the axes in the plane. The translational motion is required to meet the phase matching condition to compensate for aberrations. The two rotational motions are required to deflect and focus the light, and are essential to the versatility of the array of micromirror array lenses.
[0006] In use, the device comprises a light source that generates collimated light that incidents from the light source to the lens array. The light is reflected from the micromirror array lenses and focused onto a projection plane, where in the resulting image is viewed. Since each micromirror array lens has the ability to scan the in-focused light along the projection plane, any two or more micromirror array lenses can simultaneously focus incident light onto different positions, or the same position along the projection plane. Because each micromirror array lens can scan the whole plane (i.e., focus the incident light at any position along the plane), the projected image can be generated.
[0007] When the array of micromirror array lenses is applied to the conventional two-dimensional display devices, such as projector and/or projection television, the brightness of the projected image and power consumption of the display device are greatly improved by increasing light efficiency over prior art DMD array devices. The array of micromirror array lenses can use most incident light by adopting an optimized Random Scanning Technique. In accordance with this technique, a random scanning processor analyses brightness of each frame, and optimizes the focusing position and scanning speed of each micromirror array lens. For the purposes of the present invention, “random” means scanning is not sequential. Accordingly, in order to optimize the set of micromirror array lens combinations which can minimize the movement, minimize construction and destruction of the micromirror array lens, and the minimize scanning length for a frame rate, each micromirror array lens: (a) has an arbitrary number of micromirors; (b) scans a plane with different speed; and (b) focus light at random positions in the plane.
[0008] The random scanning technique also enables the number of micromirrors to be less than the number of image pixels without deterioration of the resolution of projected images. The gray scale of each pixel is easily achievable by controlling scanning speed and/or by controlling the number of micromirrors of each micromirror array lens.
[0009] Small sized array of micromirror array lenses can be implemented in portable electronic equipments such as mobile phones, personal digital assistants (PDA), camcorder, or even laser pointers. In such devices, the array of micromirror array lenses are combined with a laser diode modules and an automatic focusing unit to provide a very small pocket-sized two-dimensional image projector. Such devices also enable users to view large projected images from their mobile phones, personal digital assistants (PDA), and so on.
[0010] The present invention is also applicable to optical scanners, photo copy machines, laser printers, and other applicable image projection devices. In addition, the present invention may be applied to three-dimensional integrated imaging devices.
[0011] In conclusion, the advantages provided by the present invention over image projection systems of the prior art, are:
[0012] (1) It improves brightness and power consumption of a two-dimensional image projection systems;
[0013] (2) It provides a portable, pocked-sized, high quality two-dimensional image projectors;
[0014] (3) The present invention may be used in a variety of applications because each micromirror array lens of the array of micromirror array lenses can be controlled independently to have different focal length, different optical axis, lens size, and lens shape;
[0015] (4) Each micromirror array lens of the array of micromirror array lenses can be controlled to scan a plane with different speeds to easily control the light intensity of the displayed image; and
[0016] (5) A group of micromirror array lenses of the lens array can be controlled to scan the same point simultaneously to easily control the light intensity of the displayed image.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] These and other features, aspects and advantages of the present invention will be better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings, wherein:
[0018] FIG. 1 is an illustration of the two stable deflected states of a prior art pixel mirror for deflecting incident light in one of two directions;
[0019] FIG. 2 is a schematic view of a two-dimensional image projection device in accordance with the present invention;
[0020] FIG. 3 is a partial top view of a lens array in accordance with the present invention;
[0021] FIGS. 4 ( a ) and ( b ) are top views of the micromirror array lenses comprising the lens array of FIG. 3 ;
[0022] FIG. 5 is a top view of an array of micromirror array lenses at a first point in time, in accordance with principles of the present invention;
[0023] FIG. 6 is a top view of an array of micromirror array lenses at a another point in time, in accordance with principles of the present invention;
[0024] FIG. 7 is a schematic side view of a micromirror array lens in accordance with the present invention;
[0025] FIG. 8 is a perspective view showing the degrees-of-freedom of a micromirror in accordance with the present invention;
[0026] FIG. 9 is a schematic view illustration how a two-dimensional projection device in accordance with the present invention operates;
[0027] FIG. 10 is a block diagram describing the random scanning technique of two-dimensional image projection devices of the present invention;
[0028] FIG. 11 is block diagram describing a self diagnosis and correction process for two-dimensional image projection devices of the present invention; and
[0029] FIG. 12 is a schematic diagram of a portable electronic device comprising a lens array according the principles of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0030] In a particularly preferred embodiment of the invention there is provided a two-dimensional image projection device comprising an array of micromirror array lenses. Each micromirror array lens comprises a plurality of micromirrors, whose configurations may be adjusted to change the focal length, optical axis, lens size, the number of lenses, shape of lens, and others of the micromirror array lens. When applied to conventional two-dimensional display devices, the array of micromirror array lenses greatly improve the brightness of the projected image and the power consumption of the display device by increasing light efficiency.
[0031] FIG. 2 a two-dimensional image projection device 20 comprising a light source 22 , a lens array 30 , and a projection plane 24 . The light source 22 may be any conventional light source, such as a metal halide with a color wheel, a light emitted diode, a three (Red, Green, Blue) laser diode, or any other suitable light source. The light source generates Red, Green, and Blue (“RGB”) light 21 , which is reflected by the lens array 30 according to the image data, and focused onto the projection plane 24 , where the resulting image is displayed.
[0032] Referring now to FIG. 3 , the lens array 30 comprises a planar array of micromirror array lenses 32 , 34 , and 36 . Each micromirror array lens comprises a plurality of micromirrors 38 . The micromirrors 38 have the same function as a mirror and comprise a reflective surface made of metal, metal compound, or other materials with reflectivity. Many known microfabrication processes can used to fabricate a surface having high reflectivity. The micromirrors are individually controlled by actuating components that rotate and translate the micromirrors. The micromirrors are preferably parabolic in cross-section. This parabolic construction increases the focusing efficiency of the micromirror array lens, as discussed in further detail below.
[0033] The lens array 30 may comprise a series of micromirror array lenses 32 , 34 , and 36 arranged to form a substantially rectangular array. The basic configuration and operational principle of such a lens array is described in and U.S. patent application Ser. No. 10/857,714 (filed May, 28, 2004), the entire disclosure of which is incorporated herein by reference.
[0034] As shown in FIGS. 4 ( a ) and 4 ( b ), each micromirror array lens comprise an arbitrary number of micromirrors 38 that may vary in size and shape. However, it is preferred that the micromirrors comprise a hexagonal, rectangular, and/or square shape. These shapes enable the micromirrors to be easily fabricated and controlled.
[0035] In other embodiments, a cylindrical lens array or mixed lens array comprising cylindrical and/or circular lenses may be constructed.
[0036] The relative positions of the micromirror array lens 32 , 34 , and 36 are not fixed in the plane of the lens array 30 . Each micromirror array lens exists for a given time. According to the image signal, many different micromirror array lenses are “constructed” and “destroyed” within the frame speed. For example, one image frame may only require that the lens array 30 comprise only one micromirror array lens 32 , as shown in FIG. 5 . However, another image frame may require that the lens array comprise twelve micromirror array lenses 32 , as shown in FIG. 6 . For the purposes of the present invention, the word “variable” means all optical parameters, focal length, optical axis, lens size, the number of lenses, shape of lens, and others are changed according to the processed image data.
[0037] Even a group of micromirrors, in which the micromirrors are relatively separated or spaced apart, can construct a micromirror array lens so long as each micromirror has corresponding slant and the micromirrors are configured such that phases of the converging light are the same.
[0038] FIG. 7 illustrates how each micromirror array lens 32 , 34 , and 36 works. The micromirror array lens of the present invention is very similar to the prior art micromirror array lens proposed by J. Boyd and G. Cho in their paper entitled, “Fast-response Variable Focusing Micromirror Array Lens”, Proc. SPIE , Vol. 5055, 278-286 (2003), the disclosure of which is hereby incorporated by reference as if set forth in full herein. As described above, the micromirror array lens 32 comprises many micromirrors 38 . Each micromirror corresponds to a segment of a circle or a parabola. Unlike conventional concave mirrors, the micromirror array lens can change its focal length and direction of optical axis by controlling the slant of each segmental micromirror.
[0039] The micromirror array lens 32 produces an in-focus image pixel by converging collimated light 37 into one point M (see FIG. 2 ) on an image plane. This is accomplished by controlling the position of the micromirrors 38 . The phases of the arbitrary light may be adjusted to the same phase by translating each one of the micromirrors. The required translational displacement range of the micromirrors is at least half of the wavelength of light.
[0040] The focal length F of the micromirror array lens 32 is changed by controlling the rotational and/or translational motion of each micromirror 38 . Because the micromirrors can have rotational and translational motion, the micromirror array lens can be a Spatial Light Modulator (SLM). The micromirrors retract or elevate to length or shorten the optical path length of light scattered from the image, to remove phase aberrations from the image.
[0041] The mechanical structures upholding the micromirrors 38 and the actuating components that rotate and translate the micromirrors are located under the micromirrors to enable the micromirrors to be positioned closer to one another. This increases the effective reflective area of the micromirror array lens 32 . Also, electric circuits to operate the micromirrors can be replaced with known microelectronic technologies, such as MOS or CMOS. Applying the circuits under the micromirror array, the effective area can be increased by removing necessary area for the electrode pads and wires used to supply actuating power. Since the micromirrors are small in mass and generate small moments of inertia, their positions and attitudes may be changed at rate of approximately 10 kHz. Therefore, the micromirror array lens becomes a high speed variable focusing lens having a focusing response speed of approximately 10 kHz.
[0042] As discussed above, it is desired that each micromirror 38 have a curvature because the ideal shape of a conventional reflective lens has a curvature. However, since the aberration of the micromirror array lens 32 with flat micromirrors is not much different from a conventional lens with curvature if the size of the micromirrors is small enough, there is not much need to control the curvature of the micromirrors.
[0043] One benefit of the present invention is that it improves the operational method of prior art micromirror array lenses and modifies these lenses for easy implementation with existing two-dimensional image projectors. Accordingly, as shown in FIG. 8 , the present invention provides each micromirror 38 with three degrees-of-freedom motion, one translational motion 54 along the normal axis to the plane of each micromirror array lens, and two rotational motions 52 , 53 about two axes in the plane of each micromirror array lens. The translational motion is required to meet phase matching condition to compensate for aberrations. The two rotational motions are required to deflect light arbitrary direction and are essential for versatility of the array of micromirror array lenses. An array of micromirror array lenses with only two-degree-of-freedom rotational motion is also possible but its image quality may be deteriorated.
[0044] FIG. 9 illustrates the operation of a two-dimensional image projection device 50 , such as a beam projector or a projection television, comprising a lens array 54 in accordance with principles of the present invention. Accordingly, a light source (not shown) generates collimated light 51 that incidents from the light source to the lens array 52 . The light is reflected from the micromirror array lenses 56 and focused onto a projection plane 60 , wherein the resulting image is viewed.
[0045] At any given image frame, the center or optical axis of a micromirror array lens may vary. Similarly, at any given image frame, the number of micromirrors comprising a micromirror array lens, or the focal length of a micromirror array lens may vary. Since each micromirror array lens has the ability to scan the in-focused light along the projection plane, any two or more micromirror array lenses can simultaneously focus incident light onto different positions, or the same position along the projection plane. Because each micromirror array lens can scan the whole plane 60 (i.e., focus the incident light at any position along the plane), the projected image can be generated.
Random Scanning Technique
[0046] Two-dimensional image projection devices of the present invention may apply a random scanning technique (“RST”) to reduce the required number of micromirror array lenses comprising a lens array. FIG. 10 schematically illustrates how the RST is applied to such image projection devices.
[0047] The technique begins with an image signal 110 that is received from an antenna and/or receiving means. The signal is then processed by an image processor that analyses the average brightness of a frame 120 . The image processor then analyses brightness of each pixels 130 . Next, the image processor calculates the required light intensity and exposure time 140 for each pixel. The image processor then performs optimization 150 . Through the optimization, the most optimized set of micromirror array lens combinations which can minimize the movement, minimize construction and destruction of the micromirror array lens, and the minimize scanning length for a frame rate is generated. According to the optimized lens combinations, a control command for a frame is generated 160 . The control signal is sent to lens array to generate images on the screen. Because the response time of micromirror array lens (>10 kHz) is much faster than the frame speed (˜30 Hz), a two-dimensional image projection system using array of micromirror array lenses and the random scanning technique can display much more pixels than the number of micromirror array lenses. By changing the number of micromirrors of each micromirror array lens and/or scanning speed (i.e., the duration of light exposure time) of the micromirror array lenses, the gray scale can be expressed easily. The fact that the required number of micromirror array lens is much smaller than the number of pixels makes the array of micromirror array lenses very small in size. Moreover, the display device can express fine images if the array of micromirrors comprise enough micromirrors.
Self Diagnosis & Correction Technique
[0048] A self diagnosis & correction technique (“SDCT”) may also be applied to a two-dimensional image projection device. During the SDTC, the image processor analyzes the deviations of each spot from a predetermined position and correct the scale factor of the corresponding micromirror. A simplified schematic diagram of the SDCT as applied to a two-dimensional image projection device of the present invention, is shown in FIG. 11 . The SDCT system mainly consists of a light source 210 , an image sensor 250 , an image processor 260 , read only memory (ROM) 270 , a lens array 220 , and controller 240 .
[0049] This technique starts with the controller 240 . The controller generates and sends a set of test signals to the lens array 220 . Each of the micromirrors comprising the array are controlled by the test signal, and incident light from the light source 210 is deflected to several predetermined positions 235 along a projection plane 230 by the controlled micromirrors. The image sensor 250 comprises a photo detector that detects the light spots along the projection plane. The image sensor then sends an electrical signal comprising image data to the image processor 260 . The image processor also decides the pass or failure of each micromirror. This test will be done for all micromirrors in the lens array. Because the response speed of the micromirrors are slightly less than 10 kHz, entire the test can be completed for all micromirrors within a few minutes. The test also can be done while viewers are watching the image device. The test results for all micromirrors in the array is written in the ROM 270 and become reference data for the random signal processing. In the random scanning processing for two-dimensional image displaying, the failed micromirrors are excluded in construction of micromirror array lenses.
[0050] Through the self diagnose process, failed micromirrors are identified. The random signal processor optimizes the control signals to exclude failed micromirrors in operation and to compensate by adjusting the micromirror array lens combination and scanning speed. By the SDCT, the displayed image can be maintained with the same quality even if as many as ten to twenty percent (10˜20%) of micromirrors are failed. By applying SDCT, the reliability and operating lifetime of display device can be much improved.
[0051] When applying the present invention to a conventional two-dimensional display devices, the brightness of the projected image and power consumption of the display device are greatly improved by increasing light efficiency over prior art display devices. According to the prior art, the DMD array uses at most fifty percent (50%) of incident light because it has “on” and “off” positions. The light is dumped when the mirror is at “off” position. On the contrary, the array of micromirror array lenses can use most incident light by adopting the optimized Random Scanning Technique, discussed above. In that regard, the most power consuming element in a two-dimensional display device is projection lamp, and light efficiency is directly related to power consumption.
Other Embodiments
[0052] Another prospective application of present invention is a portable two-dimensional image projector, where the array of micromirror array lenses is incorporated into small electronic devices such as mobile phones, PDAs, camcorders, and other related devices. As mentioned above, the micromirror array lenses may be small in construction, which enables the array to be used with such devices.
[0053] FIG. 12 illustrates an example of a two-dimensional image projector of the present invention implemented within a small portable electronic device. In this embodiment, to miniaturize the two-dimensional image projector, a three (Red, Green, Blue) laser diode module 310 is used as a light source. To minimize undesirable effects, such as speckle and interference from coherent light, a broad band laser is preferable. An image signal 360 received from a broadcasting system, other outside device, or internal storage device is transmitted to a random scanning processing unit 370 , which sends an optimized control signal to construct a lens array 320 . The lens array deflects incident light from the laser diode to display an image. The image can be displayed on a screen, wall, or other suitable projection plane 330 . An image sensor 340 implemented into the portable electronic device, comprises a photo detector that detects scattered light from the screen. The image sensor generates and sends to an automatic focusing image processor 350 an electrical signal carrying image data. The image processor contains an automatic focusing algorithm that analyzes the image data to determine the focusing status. The image processor then sends the focusing status to a random scanning processing unit 370 . Random scanning processing unit sends a control signal to the micromirror array lenses to adjust the focusing of each of the micromirror lenses in the lens array.
[0054] In sum, the present invention improves the brightness and power consumption of conventional two-dimensional image projection systems. The present invention may be adapted to provide portable, pocked-sized, high quality two-dimensional image projection devices. Each of the micromirror array lenses comprising the lens array of the present invention may be controlled independently to have different focal lengths, different optical axes, lens sizes, and lens shapes. This enables the lens array to be applied in many applications. Further, each of the micromirror array lenses of the lens array may be controlled to scan a plane with different speeds, or a group of micromirror array lenses may be controlled to scan the same point on a plane simultaneously. This makes easy to control the light intensity on the screen.
[0055] The preceding description has been presented with reference to presently preferred embodiments of the invention. Workers skilled in the art and technology to which this invention pertains will appreciate that alterations and changes in the described structure may be practiced without meaningfully departing from the principal, spirit and scope of the invention.
[0056] Accordingly, the foregoing description should not be read as pertaining only to the precise structures described and illustrated in the accompanying drawings, but rather should be read consistent with and as support to the following claims, which are to have their fullest and fair scope. | A two-dimensional image projection device using array of micromirror array lenses and a random scanning technique is invented. Using the random scanning technique, the light efficiency is nearly doubled than that of the prior art. The invention makes a brighter and less power consuming display device possible. Because each micromirror array lens of array of micromirror array lenses can scan whole image plane, a fast self diagnosis and correction technique can be introduced in displaying device. The Self diagnosis and correction technique makes display device to maintain image quality even a few tens percent of micromirrors do not work properly. Owing to the scanning characteristics of micromirror array lens, the image projection device can express the same number of pixels image with less number of micromirrors than the prior art. This also enables small sized two-dimensional image projector, which can be incorporated in portable electronic equipments. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a method for stamping a monofilament of synthetic resin for slide fastener coupling elements, and more particularly to a stamping method for continuously providing on the monofilament coupling head portions, leg turnover portions, deformed portions facilitating bending, grooves receptive of sewing threads, etc. of slide fastener coupling elements.
2. Description of the Related Art
A method for stamping a monofilament of synthetic resin for slide fastener coupling element is known from, for example, Japanese Patent Publications 24347/1969 and 8902/1988. In the known method, as shown in FIG. 12 of the accompanying drawings, a monofilament E is continuously stamped by a pair of rotating rollers A, B having circumferential stamping teeth projections C, D as the monofilament E is supplied between the two rollers A, B.
However, in this prior art method, since the stamping teeth bite into the monofilament abruptly, cracks tend to develop in shaped portions. And since the molding teeth are separated from the monofilament suddenly after having compressed the monofilament, the pressing time is not sufficient to cure the individual shaped portion in a correct contour. Therefore it is difficult to obtain the shaped portions always with accuracy.
SUMMARY OF THE INVENTION
It is therefore an object of this invention to provide a method for stamping a monofilament of synthetic resin so as to have shaped portions, such as coupling head portions, leg turnover portions, deformed portions facilitating being, grooves receptive of sewing threads of slide fastener coupling elements, with precision.
According to this invention, there is provided a method for stamping a monofilament, between a pair of mating stamping rollers, to form shaped portions for slide fastener coupling elements, comprising: using an annular outer roller and a cylindrical inner roller for the pair of mating stamping rollers, respectively; positioning the annular outer roller and the cylindrical inner roller in such an arrangement that an outer circumferential surface of the cylindrical inner roller mates partially with an inner circumferential surface of the annular outer roller; rotating the annular outer roller and the cylindrical inner roller in a common direction; and supplying the monofilament to such mating areas of the outer and inner circumferential surfaces continuously while the outer and inner rollers are being rotated.
The above and other advantages, features and additional objects of this invention will be manifest to those versed in the art upon making reference to the following detailed description and the accompanying drawings in which several preferred embodiments incorporating the principle of this invention are shown by way of illustrative examples.
BRIEF DESCRIPTION OF THE INVENTION
FIGS. 1(a) and 1(b) are fragmentary schematic views showing the manner in which a monofilament is stamped according to a first embodiment of this invention;
FIG. 2 is a view similar to FIGS. 1(a) and 1(b), showing a second embodiment of the invention;
FIG. 3 is a perspective view, with parts omitted, of a coiled-coupling-element shaping apparatus for carrying out the invention;
FIG. 4 is a plan view showing the monofilament and 1(b);
FIGS. 5(a) through 5(e) show the manner in which the shaped monofilament is progressively wound around a mandrel to form coiled coupling elements;
FIG. 6 is a fragmentary plan view showing the finished coiled coupling elements;
FIG. 7 is a fragmentary schematic view showing a third embodiment;
FIG. 8 is a view similar to FIG. 7, showing a fourth embodiment;
FIG. 9 shows the manner in which a monofilament shaped according to the third embodiment of FIG. 7 is wound around a mandrel;
FIG. 10 shows the manner in which the shaped monofilament provided according to the invention is progressively formed into a meandering filamentary element;
FIG. 11 is a fragmentary plan view showing a finished zigzag element; and
FIG. 12 is a fragmentary schematic view showing the manner in which a monofilament is stamped according to a prior art method.
DETAILED DESCRIPTION
Various embodiments of this invention will now be described with reference to the accompanying drawings.
FIGS. 1(a) and 1(b) shows the manner in which a monofilamentary starting material (described below) is stamped by a pair of stamping rollers (described below), which is partially broken away, according to a first embodiment of the invention.
In FIGS. 1(a) and 1(b), reference numeral 1 designates a starting material, for forming slide fastener coupling elements, in the form of a monofilament of thermoplastic synthetic resin such as polyamid or polyester. Semi-shaped portions of a prospective slide fastener coupling element, such as a coupling head portion, a leg turnover portion, a deformed portion facilitating bending, and a groove receptive of sewing thread, are successively formed on and along the monofilament 1 as the monofilament 1 is compressed between a pair of mating rotating stamping rollers 2, 3. As shown in FIG. 3, one of the stamping rollers 2 is an annular outer roller having on and around its inner circumferential surface 4 a predetermined number of pressing projections 6 at predetermined distances. The other roller 3 is a cylindrical inner roller having on and along its outer circumferential surface 5 a predetermined number of recesses 7 at predetermined distances. The pressing projections 6 cooperate with the corresponding recesses 7 to perform stamping.
Specifically, these two stamping rollers 2, 3 are positioned in such an arrangement that the inner circumferential surface 4 of the annular outer roller 2 is brought firstly gradually near the outer circumferential surface 5 of the cylindrical inner roller 3 toward the climax point (center of the mating areas of the inner and outer circumferential surfaces 4, 5) and then gradually away from the outer circumferential surface 5 as the outer and inner rollers are rotated in the same direction. While the two stamping rollers 2, 3 are being rotated in the same direction, i.e. clockwise as indicated by arrows a, b in FIGS. 1(a) and 1(b), the monofilament 1 is continuously supplied to the mating areas between the two rollers 2, 3 so that various semi-shaped portions of a prospective slide fastener coupling element are formed on the monofilament 1 by the pressing projections 6 and the coacting recesses 7.
Since the two stamping rollers 2, 3 are located in this arrangement, the pressing projections 6 are progressively brought toward the coacting recesses 7 as the two rollers 2, 3 rotate in the same direction. During that time, the individual semi-shaped portion 8 of the monofilament 1 is progressively formed as shown in FIG. 1(a) and is then completely compressed into a final shape 9 as the pressing projection 6 and the coacting recess 7 come near each other at the climax point as shown in FIG. 1(b), whereupon the pressing projection 6 and the recess 7 are progressively separated away from each other to release the compressing force. Therefore cracks due to a sudden deformation would be prevented, and the curing or hardening time of the completely shaped portion 9 is increased.
The individual pressing projection 8 and the coacting recess 7 have such shapes as to form a coupling head portion, a leg turnover portion, a deformed portion facilitating bending, a groove receptive of a sewing thread, etc. of a prospective slide fastener coupling element. In this embodiment, the pressing projections 8 are disposed on the annular outer roller 2 while the recesses 7 are disposed on the cylindrical inner roller 3. Alternatively, the pressing projections 6a and the recesses 7a may be disposed reversely, i.e., on the cylindrical inner roller 3 and the annular outer roller 2, respectively, as shown in FIG. 2.
FIG. 3 shows one example of a coiled-coupling-element shaping apparatus for carrying out the method of this invention. A mandrel holder 11 is non-rotatably mounted at the center of the apparatus, and a mandrel 10 is fixedly attached on the top of the mandrel holder 11 so that the shaped monofilament is advanced upwardly as bent and wound around the mandrel 10 and thus shaped into coiled coupling elements 15. As shown in FIG. 5, the mandrel 10 has therein a passageway through which a core cord 12 is to be supplied.
A rotary member 13 is disposed about the base of the mandrel holder 11 and is adapted to be rotated, in a direction indicated by an arrow, by a suitable drive means. A pulley 14 for supplying the monofilament 1 is disposed inside the rotary member 13 at a position symmetrical to, i.e., diametrically opposite to the cylindrical inner roller 3. As the rotary member 13 is rotated, the cylindrical inner roller 3 and the pulley 14 are revolved about the mandrel holder 11 and are rotated on their own axes, thereby bending and winding the shaped monofilament 1 around the mandrel 10. The annular outer roller 2 is disposed around the rotary member 13; the cylindrical inner roller 3 is located relative to the annular outer roller 2 in such a manner that the outer circumferential surface 5 of the inner roller 3 is near the inner circumferential surface 4 of the outer roller 2 to stamp the monofilament 1.
In operation, the annular outer roller 2 and the rotary member 13 are rotated in such a manner that the rate of rotations of the annular outer roller 2 is slightly smaller lower than that of the rotary member 13. And while the rotary 13 makes one complete revolution about the mandrel holder 11, the cylindrical inner roller 3 and the pulley 14 are rotated on their own axes in such a manner that the circumferential speed of the pulley 14 meets with that of the inner circumferential surface of the annular outer roller 2. Meanwhile, the monofilament 1 is positively supplied, in a predetermined tension, by a length equal to the distance between an adjacent pair of coupling head portions, namely, the length of a single coiled coupling element 15, during which time the monofilament 1 is stamped and is then wound around the mandrel 10 by a complete turn.
The stamping method of this invention may be carried out, continuously with shaping the monofilament into coiled coupling elements, in the coiled-coupling-element shaping apparatus of FIG. 3, or may be carried out, independently of the step of shaping the monofilament into coiled coupling elements, in a private stamping apparatus.
FIG. 4 shows the monofilament shaped according to the stamping method of this invention; FIGS. 5(a) through 5(e) show the sequence of steps in which the shaped monofilament is progressively wound around the mandrel 10 to provide the individual coiled coupling element; and FIG. 6 shows finished coiled coupling elements 15. The shaped monofilament of FIG. 4 has a coupling head portion 16, a pair of flattened portions 17, 17 facilitating bending at the side of the coupling head portion 16, and a pair of recess portions facilitating bending at the side of the leg turnover portion. This shaped monofilament is progressively bent and wound around the mandrel 10, in which a core cord 12 is received, as shown in FIGS. 5(a) through 5(e). With continued bending and winding, the shaped monofilament is formed into finished coiled coupling elements 15 shown in FIG. 6.
FIGS. 7 and 8 show third and fourth embodiments, respectively, of the stamping method of this invention in which a monofilament is stamped so as to have only coupling head portions 16 or 16a. FIG. 9 shows the manner in which the shaped monofilament of FIG. 7 is wound around a mandrel 10 to form coiled coupling elements.
FIG. 10 shows the manner in which the shaped monofilament having only coupling head portions 16 is bent at regular distances in a meandering pattern such that each coupling head portion 16 is disposed centrally between a pair of adjacent turnover portions on opposite sides and such that the successive coupling head portions 16 are arranged on an imaginary bending line (described below) 19. This meandering monofilament is folded over itself by bending along the bending line 19, thereby providing finished zigzag coupling elements 20 shown in FIG. 11.
According to this invention, partly since the inner circumferential surface of the annular outer roller and the outer circumferential surface of the cylindrical inner roller are curved in a common direction, and partly since as the outer and inner rollers are rotated in the same direction, the inner and outer circumferential surfaces are brought firstly gradually near each other toward the climax point and secondly gradually away from each other from the climax point, the supplied monofilament can be gradually stamped without causing cracks in the stamped and thus shaped portions. And after passing the climax point, the shaped portions can be gradually separated from the shaping teeth, and therefore, the entire pressing time can be increased to minimize chances that the shaped portions would be adversely deformed. Therefore, by the stamping method of this invention, it is possible to form on the monofilament various shaped portions, such as a coupling head portion, with accuracy. | A method for stamping a monofilament between a pair of mating stamping rollers to form shaped portions for slide fastener coupling elements includes using an annular outer roller and a cylindrical inner roller with pressing projections on a mating stamping surface of at least one of the rollers. The rollers are positioned in such an arrangement that an outer circumferential surface of the cylindrical inner roller mates partially with an inner circumferential surface of the annular outer roller. The rollers are rotated in a common direction, and monofilament is supplied continuously to an area where an inner circumferential surface of the annular outer roller and an outer circumferential surface of the cylindrical inner roller mate. The monofilament is thereby pressed for a longer time in order to form accurately coupling head portions of slide fasteners. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to detection systems and is directed more particularly to a system and method for detecting moisture in roofs.
2. Description of the Prior Art
Current non-destructive methods for determining the presence of moisture in roof structures include (1) infrared thermographic, and (2) nuclear moisture meter detection of moist insulation. Both methods require that a team of people go onto the roof, or above the roof, as in the case of aerial thermography. Each method detects moisture indirectly, from the level of heat released, or by the backscatter of slow neutrons from hydrogen atoms. Each method provides no information until the inspection is scheduled and completed.
In U.S. Pat. No. 4,598,273, issued Jul. 1, 1986, in the name of Bynum O. Bryan, et al, there is disclosed a leak detection system in which water-activated batteries power autonomous transmitters mounted on a roof top. When a battery becomes wet, an associated transmitter sends a signal which indicates wetting and identifies the location of the transmitter. However, upon wetting the batteries expend their energy and must be replaced. Further, there is no provision for testing the sensors non-destructively in situ. Therefore, false readings eventually occur. Still further, the batteries have a limited shelf life and must be replaced even when not activated for long periods of time. The number of transmitters involved, and the continuous replacement of batteries, renders the Bryan system unduly expensive.
There is thus a need for a relatively inexpensive moisture sensing system which does not require people on or above the roof to operate, and which does not require continuous attention and/or replacement of parts to be kept in active service, but which does provide for inspection from remote locations to determine whether moisture is present in a roof structure.
There is further a need for an improved method for detecting moisture in a roof structure.
SUMMARY OF THE INVENTION
An object of the invention is, therefore, to provide a roof moisture sensing system which is relatively inexpensive, does not require people on or above the roof to conduct an inspection of the roof, does not require continuous attention and/or replacement of parts, such as batteries, and which recovers to its original condition upon drying; such that the moisture sensors may be used again and again and do not expend themselves when wetted.
A further object of the invention is to provide an improved method for detecting moisture in a roof structure.
With the above and other objects in view, as will hereinafter appear, a feature of the invention is the provision of a roof moisture sensing system comprising a radio frequency pulse transmitter, a moisture sensor disposed on a roof, and a radio receiver adapted to monitor resonance of the moisture sensor activated by a pulse transmitted by the pulse transmitter. The receiver is adapted to analyze the resonance of the sensor to determine the presence of moisture in the sensor. The transmitter and the receiver may be remote from the sensor and from the roof.
In accordance with a further feature of the invention, there is provided a method for determining the presence of moisture in a roof structure. The method comprises the steps of providing a moisture sensor on the roof structure, the moisture sensor comprising an inductor and a capacitor, the capacitor comprising first and second electrodes and water-absorptive material, or air, disposed therebetween, and the inductor comprising an induction coil. The first and second electrodes are in electrical communication with first and second ends of the induction coil. The capacitor is adapted to change the resonant frequency of the sensor in response to wetting of the capacitor water-absorptive material. The method further includes the steps of directing radio frequency power at the sensor to actuate resonance of the sensor, and monitoring resonant frequency signals emitted by the sensor to determine thereby whether the sensor is dry or wet.
The above and other features of the invention, including various novel details of construction and combinations of parts, will now be more particularly described with reference to the accompanying drawings and pointed out in the claims. It will be understood that the particular systems and methods embodying the invention are shown by way of illustration only and not as limitations of the invention. The principles and features of this invention may be employed in various and numerous embodiments without departing from the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
Reference is made to the accompanying drawings in which are shown illustrative embodiments of the invention, from which its novel features and advantages will be apparent.
In the drawings:
FIG. 1 is a diagrammatic representation of one form of roof moisture sensing system illustrative of an embodiment of the invention;
FIG. 2 is a perspective view of a roof moisture sensing sensor comprising a component of the system of FIG. 1;
FIG. 3 is a diagrammatic sectional view of the sensor of FIG. 2 in combination with roof top components; and
FIG. 4 is a diagrammatic representation of another form of roof moisture sensing sensor and system illustrative of an alternative embodiment of sensor, as well as a system which may be used as an alternative system or may be used in combination with the system of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, it will be seen that an illustrative embodiment of the inventive system includes (1) a radio frequency (RF) radio transmitter 10 adapted to transmit pulses of RF signals 12, (2) one or more moisture sensors 14 disposed on a roof structure 16 of a structure 18 and resonantly activatable by the pulses of signals 12, and (3) a radio receiver and analyzer 20 adapted to receive and analyze resonant signals 22 from the sensors 14 to determine whether the roof structure 16 contains a substantial amount of moisture.
Referring to FIG. 2, it will be seen that the moisture sensors 14 each comprise an inductor 24 and a capacitor 26. The capacitor 26 includes first and second electrode plates 28, 30 and a water-absorptive material 32 disposed therebetween. The inductor 24 includes a substantially flat non-conductive plate 34 having an induction coil 36, which may be a printed circuit, covered with a plastic film 40.
Still referring to FIG. 2, it will be seen that the first and second electrode plates 28, 30 of the capacitor 26 are in electrical communication, as by wires 42, 44 with first and second ends 46, 48 of the induction coil 36. A portion 38 of the wire 42, extending to the induction coil first end 46, may comprise a printed circuit bridged through the plate 34 to the coil end 46.
The moisture sensor 14 may include a stem member 50 interconnecting the inductor 24 and the capacitor 26. The stem member 50 is of a rigid material, preferably of a tubular configuration, with the wires 42, 44 passing therethrough.
Referring to FIG. 3, it will be seen that a roof 16, of the type in which the moisture sensing system finds utility, typically is a flat roof, or low-slope roof (not shown) where water sometimes reaches a flaw in the water proof membrane, and seeps into the roof structure. In the illustrative example shown in FIG. 3, the roof structure 16 includes a substrate layer 52, which may be cement, or the like, an insulation layer 54, a membrane layer 56, which may be tar paper, or the like, and a ballast layer, which may be pavers, rock, gravel, or the like (not shown), covering the membrane layer 56. Embedded in the roof structure, as between the insulation layer 54 and the membrane layer 56, or on top of the membrane layer 56, is the inductor plate 34, with the stem member 50 and capacitor 26 extending therefrom and to or through the insulation layer 54 (the latter shown in FIG. 3), with a distal end 58 of the water-absorptive capacitor 26 contacting an upper surface 60 of the roof substrate layer 52, or other water-impermeable element in the roof assembly.
In preparing for operation of the system disclosed herein, a number of the moisture sensors 14 are placed in the roof structure 16, as shown in FIG. 3 and described above. The length of the stem member 50 is selected such that the distal end 58 of the capacitor water absorptive material 32 is brought to bear against the surface 60 upon which moisture may accumulate. In some instances, the stem member 50 is omitted and the capacitor 26 depends directly from the underside of the inductor plate 34.
When an inspection for roof moisture is desired, the transmitter 10 is caused to transmit a series of short pulses of several KW peak power. The pulses 12 are sent at the frequency at which the autonomous sensors 14 are resonant. Upon receiving the pulses 12, the sensors 14 resonate at one frequency when dry and at a distinctly different frequency when wet. Wetting of the absorptive material 32 changes the dielectric constant of the capacitor 26 and shifts the resonant frequency of the sensor circuit. The radio receiver and analyzer 20 detects the resonant signals of the sensors 14 and generates a report, or display, indicating whether there are any sensors 14 that are resonating at a frequency different from that of the dry sensors, thereby indicating probable wetting of the roof. When the roof dries out, the absorptive material 32, in due course, also dries and the affected sensor thereafter resonates "dry" signals, rather than "wet" signals, until the sensor capacitor is again wetted.
The transmitter 10 and receiver 20 may be permanent installations or portable devices, and may be combined into a single unit.
In FIG. 4, there is shown an alternative embodiment in which the capacitor 26 and inductor 24 are both disposed in or on the plate 34. The induction coil is covered by the plastic film 40, but not the capacitor 26. The FIG. 4 embodiment of sensor is well adapted for detection of moisture on or near a roof surface, and operates in the same manner as the embodiment shown in FIGS. 2 and 3.
There is thus provided a roof moisture sensor system facilitating quick and easy inspection from the ground of roof areas for moisture accumulation. There is further provided such a system which can be used time and time again, without requiring continuous replacement of parts and without attention between uses to be maintained in an active condition.
Once it is determined that a portion of the roof structure 16 is wet, a gate dip oscillator 62 (FIG. 4) may be used to pinpoint areas of concern. The gate dip oscillator 62 (GDO) is pre-tuned to emit RF energy at the resonant frequency of a dry roof moisture sensor. However, as sensor absorptive materials 32 become wet, the dielectric constant of the material increases. With the increase in the dielectric constant, the resonant frequency of the sensor decreases from the dry sensor resonant frequency.
In practice, after the receiver analyzer 20 indicates that there is an accumulation of moisture in the roof structure, the oscillator 62 is manually passed in close proximity over individual sensors. A dip in gate current, indicated in a display 64 on the oscillator 62, indicates a dry sensor, while no dip indicates a wet sensor. Rather than a needle-type display 64, as shown in FIG. 4, the display may be a light signal and/or audible signal.
The oscillator 62 may, of course, be used initially to inspect the roof structure 16, at less expense than the transmitter-receiver system, but requires personnel on the roof and requires time for individual checks of each sensor. In practice, it has been found preferable to use the transmitter-receiver system to complete an inspection virtually instantly without having to physically access the roof top, and follow, only when necessary, with an inspection by oscillator of each sensor. The receiver in the first-described system advises as to the presence of a leak and as to the general whereabouts of the sensors indicating the leak. The follow-up oscillator inspection, conducted only when warranted, provides an accurate sensor-by-sensor plot of exactly where the leak is and the path of the water in the roof structure. Thus, the transmitter-receiver system facilitates quick and easy inspections which, in most cases, is all that is needed. Such inspections can be followed by the more precise oscillator-based inspections when required.
While the oscillator 62 is shown in use with the FIG. 4 embodiment of sensor, it will be apparent that the oscillator finds equal utility in combination with the embodiment of sensors shown in FIGS. 2 and 3.
It is to be understood that the present invention is by no means limited to the particular constructions and methods herein disclosed and/or shown in the drawings, but also comprises any modifications or equivalents within the scope of the claims. | A roof moisture sensing system includes (1) a radio frequency pulse transter, (2) a moisture sensor disposed on a roof, and (3) a radio receiver adapted to monitor resonance of the moisture sensor activated by a pulse transmitted by the pulse transmitter. The receiver is adapted to analyze the resonance of the sensor to determine the presence of moisture in the sensor. The transmitter and the receiver can be remote from the sensor and the roof. | 4 |
BACKGROUND ART
[0001] 1. Field of the Invention
[0002] The invention relates to a method for the production of a lighting element including at least one luminescent light source and an inserted light-guiding body. More particularly, the invention relates to a lighting element of uniform construction and a method of making same.
[0003] 2. Description of the Related Art
[0004] Such a method for the production of a lighting element is known from the German patent specification DE 101 63 117. Here, a first LED-partial body is permanently connected to a second, larger light-guiding body by injection molding. However, a special component is used here as the LED-partial body. This solution also results in portions of large material build-ups in the injection mold. This requires inter alia a longer cooling-off time and brings about an uneven cooling.
[0005] Therefore the problem underlying the present invention is to develop a method for the production of light-guiding lighting elements by using at least one inserted light-guiding body, wherein the transparent partial illuminating bodies are connected to one another in a safe, rapid and precise manner with respect to the form thereof with the usual capacity of the known injection methods.
SUMMARY OF THE INVENTION
[0006] A method produces a lighting element that includes at least one luminescent diode and an inserted light-guiding body. The light-guiding body receives light emitted by the luminescent diode. The luminescent diodes are secured to the light-guiding body by an injection molding process of a transparent plastic material such that at least 50% of the surface of the light emitting diode is covered by the injected material during the manufacturing thereof, and that the maximum wall thickness of the injected layer does not exceed three-times the minimum wall-thickness of the layer.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] Advantages of the invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:
[0008] FIG. 1 is a cross-sectional end view of one embodiment of the invention; and
[0009] FIG. 2 is a cross-sectional side view of the embodiment shown in FIG. 1 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0010] FIGS. 1 and 2 show a lighting element 70 . In the embodiment shown, the lighting element 70 is a raised automobile brake light. The lighting element 70 , which is arranged here, for example, with the help of a housing 50 in a trunk lid 60 of a motor vehicle, is made of a group of individual lighting elements 10 , wherein every element 10 includes at least one light source 11 . In the preferred embodiment, the light source 11 is a light emitting diode (LED). The lighting element 70 has a diffusing screen 40 , the outer surface of which is adapted to the shape of the surrounding surface curvature of the trunk lid 60 .
[0011] In this context, the individual LED 11 can be a standard LED or a preliminary stage LED. The latter is produced only for installation in the brake light 70 . The LED 11 usually includes the electrical terminals 1 , 4 located in one plane, the light-emitting chip 6 , a bond wire 2 , and a reflector dish 5 . The latter is a part of the cathode 4 . The chip 6 is seated in the reflector dish 5 . The chip 6 contacts the anode 1 using the bond wire 2 . The bond wire 2 is thereby preferably located in the plane, which is defined by the centerlines of the electrodes 1 , 4 . The zone located above the chip 6 transports the light emitted by the chip 6 losslessly, as far as possible, to the outer surface 12 of the LED 11 .
[0012] The standard LED used in FIG. 1 has a geometric form, which is substantially made of three geometric bodies arranged on top of one another. The first geometric body is a short, at least approximately straight cylinder 13 , which includes, if desired, two planar flat portions, which are aligned generally parallel to the LED centerline 7 . The second geometric body is a truncated cone 15 arranged on the upper end face 14 of the cylinder 13 or a comparable rotational body, which tapers away from the cylinder 13 . The third geometric body is a calotte and/or a comparable rotationally symmetrical cap, which is positioned on the upper, smaller end face of the truncated cone. The surface line of the truncated cone thereby passes tangentially into the contour of the cap. The upper end face 14 of the cylinder 13 is larger than the lower end face of the truncated cone 15 . The centerlines of the cylinder 13 and of the truncated cone 15 are located on the LED centerline 7 .
[0013] If desired, a notch 16 , a channel or a waist, shown as a dashed line in FIG. 2 , which ends on the end face 14 , is present in the lower regions of the truncated cone 15 .
[0014] Should the individual lighting element 10 be used in a group of several individual lighting elements, the LEDs 11 are arranged on a lamellar circuit board 18 . For this purpose, the LEDs 11 are soldered permanently on the circuit board 18 after being previously glued thereon. The circuit board 18 connects the individual LEDs 11 using superimposed conductor tracks. If desired, every other electronic component, such as multipliers, blocking diodes or integrated circuits, are arranged on the circuit board 18 in known manners. The circuit board 18 positions the LEDs 11 in relation to one another and later—during the coating—in the injection molding device. If desired, the electrodes 1 , 4 of the LEDs 11 are also discretely connected electrically using individual cables.
[0015] In the embodiment shown, the inserted light-guiding body 21 located opposite to the respective LED 11 has the shape of a partial paraboloid, which is flattened on both sides and also truncated at the top and at the bottom. The flattened lateral surfaces 26 , 27 are located approximately parallel to a midplane, which is located according to FIG. 1 on the centerline 7 of the respective individual lighting element 10 . The minimum distance of the lateral surfaces 26 , 27 from the midplane amounts, e.g. to 50% of the maximum LED diameter or the maximum LED width. In the example embodiment, the distance between the lateral surfaces 26 , 27 is larger towards the main light exit surface 41 .
[0016] A spherical concave recess 25 is present in the end face 24 of the lower truncation according to FIG. 2 . In this context, the recess 25 is curved in such a way that the gap 19 lying between the recess 25 and the LED 11 has an at substantially constant width.
[0017] The other end face 23 is a top face, planar and oriented normal to the centerline 7 of the individual lighting element 10 . If desired, a short pin 29 , cf. FIG. 2 , is molded in the middle region, e.g. centrally, wherein the short pin 29 facilitates the handling and positioning when coating by means of injection molding. The length of the pin 29 —measured in the longitudinal extension along the centerline 7 —is shorter than the thickness of the diffusing screen 40 in the vicinity of the pin. A transparent, colorless plastic is provided as the material for the diffusing screen.
[0018] Should several individual lighting elements 10 be combined in a group 70 and should these lighting elements 10 be located adjoining one another, each would be connected to one another using at least one web 28 . In this context, each web 28 has a semi-circular cross-section. The webs 28 adjoin flush to the end faces 23 wherein they form a planar or curved surface with the latter.
[0019] For the purpose of coating by means of injection molding, the circuit board 18 is inserted with the LEDs 11 and the group consisting of inserted light-guiding bodies 21 into an injection mold. In this context, the distance of individual LED 11 from the inserted light-guiding body 21 at the narrowest place amounts to between 0.3 mm and 3 mm. The injection mold is designed in such a way that the finished injected layer for each pair of LED and inserted light-guiding body in turn forms a partial paraboloid 30 , which is flattened on both sides and truncated at least at the top. The lower edge of this partial paraboloid rests against the LED 11 below a plane, which extends through the center of gravity of the LED chip 6 and, secondly, is aligned normal to the centerline 7 . In the example embodiment, the lower edge 32 of the injected layer 30 rests against the end face 14 of the cylinder 13 of the LED 11 . For example, the edge 32 is located directly in the geometrical cut edge, which is formed by the penetration of the cylinder 13 and of the rotational body and/or of the truncated cone 15 .
[0020] The surface of the partial paraboloid 30 is located at a distance from the surface of the partial paraboloid of the inserted light-guiding body 21 , said distance corresponding to e.g. two-times the width of the gap 19 . The injected layer 30 has an almost constant wall-thickness over large regions. In zones of strong curvature, the wall-thickness can increase up to three-times the width of the gap. These small differences in the wall-thickness enable a production of the individual lighting element 10 without any problems.
[0021] The injected layer 30 positively engages behind the corresponding LED in case of LEDs having a notch 16 . The inserted light-guiding bodies 21 can also have notches, channels or annular grooves of the same function. The injected layer 30 may be a colorless, transparent plastic is used for the coating by means of injection molding. FIG. 2 illustrates the injected layer 30 only in case of the first inserted light-guiding body 21 .
[0022] In another step, the diffusing screen 40 is sprayed onto the end surfaces 23 of the inserted light-guiding body 21 . In this context, the diffusing screen 40 engages around the injected layer 30 , in the upper fifth part. The diffusing screen 40 accordingly covers the inserted light-guiding body 21 on the end face 23 and the injected layer 30 on the upper edge completely. It has a flange-shaped installation edge 42 , which is parallelly displaced in relation to its main light exit surface 41 and which surrounds the entire brake light 70 . The main light exit surface 41 is designed with a smooth or structured surface. For example, a red, transparent thermoplastic is used as the material.
[0023] The light-guiding and current-carrying components 11 , 21 , 30 , 18 of the middle, raised brake light 70 are surrounded by the housing 50 on the rear side as shown in FIG. 1 . The housing 50 made from a hard substance, e.g., a metal, is a dish which can be closed with a lid. In this context, the lid is a diffusing screen 40 seated tightly on the dish. For this purpose, sealing contours 45 , 51 contacting one another flatly are embodied on the diffusing screen 40 and on the housing 50 . For the protection of these sealing contours 45 , 51 and for holding a sealing ring 48 , the housing 50 is partially guided around the diffusing screen 40 as a supporting edge as shown in FIG. 1 .
[0024] The brake light 70 is installed in the trunk lid, in the tailgate or on the rear roof edge in such a way that the surface of the diffusing screen 40 adjoins tangentially to the surface of the autobody sheet steel 60 carrying the brake light 70 . In this context, the autobody sheet steel 60 can also be manufactured from a non-metallic material. The diffusing screen 40 is inserted from the rear side together with the housing 50 into a recess 61 and is clamped there by means of a leaf spring 63 (with a two-fold curvature here) against a mounting bracket 62 , which is stationary in relation to the autobody sheet steel 60 . In the installed state, the recess 61 is sealed by the diffusing screen 40 and the sealing ring 48 resting on the flange-type edge 42 of the diffusing screen 40 against the intrusion of water and dirt.
[0025] In order to create the typical appearance of a middle brake light, the colors of the individual components 11 , 21 , 30 , 40 can be used in different variations.
[0026] Certain substances, which change the wavelength of the light emitted from the chip 6 can be combined with the materials of the individual transparent components of the brake light 70 , as a result of which the subjectively recognizable luminous color corresponds to that of a typical brake light 70 , although the material of the unlighted brake light has another color, e.g. the color of the surrounding autobody sheet steel 60 .
[0027] An individual lighting element 10 can naturally also be used separately.
[0028] The invention has been described in an illustrative manner. It is to be understood that the terminology, which has been used, is intended to be in the nature of words of description rather than of limitation.
[0029] Many modifications and variations of the invention are possible in light of the above teachings. Therefore, within the scope of the appended claims, the invention may be practiced other than as specifically described. | A method produces a lighting element that includes at least one luminescent diode and an inserted light-guiding body. The light-guiding body receives light emitted by the luminescent diode. The luminescent diodes are secured to the light-guiding body by an injection molding process of a transparent plastic material such that at least 50% of the surface of the light emitting diode is covered by the injected material during the manufacturing thereof, and that the maximum wall thickness of the injected layer does not exceed three-times the minimum wall-thickness of the layer. | 5 |
REFERRAL TO PRIOR APPLICATION
This application is a continuation-in-part of application Ser. No. 08/505,467, filed Jul. 21, 1995, now abandoned, by the same title and same inventor.
BACKGROUND OF THE INVENTION
1) Field of the Invention
The field of this invention relates to a manually operable apparatus which is to be used to drive a boat anchor into the ground without the aid of additional and separate tools, and also can be used for the purpose of driving tent stakes into the ground without the aid of additional and separate tools.
2) Description of the Prior Art
The use of manually operable devices, that are called slide hammers for driving posts into the ground, have long been known. Boats frequently come ashore to areas where there is not located a structure to facilitate tying down of the boat. Common such structures would be a rock, a plurality of rocks, a log or a tree. A common form of tying down is to take a conventional marine anchor and embed it as best as possible within a sandy beach or some other loose soil shoreline. However, upon the boat encountering any significant amount of wind, the boat will almost assuredly be released from its mooring which can result in damage or loss of the boat.
One problem in the past with slide hammers has been that once they are installed to moor a boat and the boat is left unattended, the slide hammer is subject to theft. Generally the slide hammer is a reasonable expensive purchase and therefore its loss requires an expensive replacement. Also, the boat which is moored by the slide hammer is permitted to just float away and is also subject to loss or damage. It would be desirable to find a way to use a slide anchor to anchor a boat, but where the slide anchor itself did not remain embedded within the ground so that it can be removed and stowed away in a safe place, thereby preventing the theft of the slide anchor.
Prior art driving devices have normally been designed for a single purpose. It would be desirable to have a driving device to not only be used as a boat anchor, but could also be used for other useful purposes such as driving tent stakes.
SUMMARY OF THE INVENTION
An anchor for a boat which is constructed to include an elongated, rigid, preferably metal stake which has a sharply pointed lower end and an upper end formed into a head which is polygonal shaped. Fixedly mounted on this stake directly adjacent the head is an upper abutment with a lower abutment being also fixedly mounted on a stake some distance spaced from the upper abutment and also some distance spaced from the sharp pointed lower end of the stake. Slidably mounted on the stake between the upper abutment and the lower abutment is a hammer. This hammer can be manually grasped and repeatedly impacted against the lower abutment to cause penetration of the sharp pointed lower end of the stake into soil or sand. Also fixedly mounted on the stake directly adjacent both the upper abutment and the lower abutment are tie down rings. A finned attachment can be mounted in conjunction with the stake located between the lower abutment and the sharp pointed end of the elongated stake with this finned attachment to provide securement for the stake to be used in conjunction with sand or loose soil. One the finned attachment is installed within the ground, the installing stake and hammer can be removed and replaced by an attaching stake which includes a tie down ring. This attaching stake is to be locked to the finned attachment. The attaching stake may be separately driven into the ground. A tent stake having a polygonal shaped opening in its head is to connect with the polygonal shaped head in a close fitting manner. The anchoring apparatus can then be turned upside down with the hammer to be slidingly impacted against the upper abutment which will result in penetration of the tent stake within a supporting surface. When the tent stake or attaching stake has been fully installed, the head is disengaged from the tent stake.
A primary objective of the present invention is to create the most versatile on-shore anchorage system available providing a secure tie-off location from the sandiest beach to the hardest packed soil for a personal watercraft to a large houseboat.
Another objective of the present invention is to provide a compact anchoring apparatus which can be carried within a boat which can be utilized to form a secure anchoring structure on a beach or other shoreline with conditions from hard pack soil to soft sand without requiring the aid of additional and separate tools.
Another objective of the present invention is to provide a solid anchoring device useful for houseboats, boats, personal watercraft, tents, canopies, tarps, awnings, recreational vehicles, mobile homes and in rescue operations.
Another object of the present invention is to provide a multi-purpose tool for driving, hammering, pulling and prying.
Another objective of the present invention is to construct an anchoring apparatus which can be manufactured at a reasonable cost and thereby sold to the ultimate consumer at a reasonable cost.
Another objective of the present invention is to construct a marine anchoring apparatus which can be installed within a very short period of time, even by people with minimal physical strength.
Another objective of the present invention is to provide an anchoring apparatus that once installed within the ground, only a small portion of the anchoring apparatus is installed within the ground with the installing portion of the anchoring apparatus not being mounted within the ground, thereby not being subject to theft and making available the marine anchoring apparatus for other uses.
Another objective of the present invention is to construct the hammer in such a manner that it minimizes the possibility of injury to the user.
Another objective of the present invention is to construct an anchoring apparatus with a hammer type head which can be utilized for other purposes such as installing tent stakes, attaching stakes and driving, hammering, prying or pulling situations that may occur.
BRIEF DESCRIPTION OF TEE DRAWINGS
FIG. 1 is a side elevational view of the first embodiment of the marine anchoring apparatus of the present invention showing such installed on the beach or other shoreline with a boat being tied to the anchoring apparatus;
FIG. 2 is an enlarged side elevational view of the first embodiment of the marine anchoring apparatus of the present invention;
FIG. 3 is a longitudinal cross-sectional view of the first embodiment of the marine anchoring apparatus of the present invention taken along line 3--3 of FIG. 2;
FIG. 4 is a transverse cross-sectional view through the hammer of the first embodiment of the marine anchoring apparatus of the present invention taken along line 4--4 of FIG. 2;
FIG. 5 is a view similar to FIG. 2 showing the addition of a first finned attachment for the purpose of installation within sandy or loose particulate soil in order to achieve a solid securement within these kinds of supporting surfaces;
FIG. 6 is a transverse cross-sectional view through the first finned attachment taken along line 6--6 of FIG. 5;
FIG. 7 is a side elevational view depicting usage of the first embodiment of the marine anchoring apparatus of the present invention to install a tent stake within ground;
FIG. 8 is an end view of the head portion of the first embodiment of the marine anchoring apparatus when connected with the tent stake taken along line 8--8 of FIG. 7;
FIG. 9 is a cross-sectional view through the tent stake taken along line 9--9 of FIG. 7;
FIG. 10 is a side elevational view of a second embodiment of the marine anchoring apparatus of this invention;
FIG. 11 is a transverse cross-sectional view taken along line 11--11 of FIG. 10;
FIG. 12 is a side elevational view of the second embodiment of the marine anchoring apparatus of this invention showing connection with a second finned attachment for installation within the ground;
FIG. 13 is a cross-sectional view taken along line 13--13 of FIG. 12;
FIG. 14 is a side elevational view of the second embodiment of the marine anchoring apparatus of this invention showing disengagement of the installing structure from the second finned attachment and replacement of an attaching stake in conjunction with the second finned attachment;
FIG. 15 is a side elevational view showing the second finned attachment being connected with the attaching stake;
FIG. 16 is a longitudinal cross-sectional view taken along line 16--16 of FIG. 15;
FIG. 17 is a side elevational view similar to FIG. 12 but showing the second embodiment of the marine anchoring apparatus connecting with a third finned attachment which is designed primarily for use only in sand;
FIG. 18 is a view similar to FIG. 15 but showing the attaching stake being connected with the third finned attachment shown in FIG. 17;
FIG. 19 is a side elevational view showing the second embodiment of the marine anchoring apparatus of this invention being used to install specially designed tent stake;
FIG. 20 is a cross-sectional view taken along line 20--20 of FIG. 19;
FIG. 21 is a cross-sectional view taken along line 21--21 of FIG. 19; and
FIG. 22 is a view depicting usage of the special form of tent stake that has been installed utilizing the second embodiment of the marine anchoring apparatus of this invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring particularly to the drawings, there is shown a hull of a boat 10 which has mounted thereon a tie down ring 12. Extending from the tie down ring 12 are two ends of a rope 14. One end of the rope 14 is connected to tie down ring 16 with the opposite end of the rope 14 being connected to tie down ring 18. It is to be understood that it is within the scope of this invention that only one end of the rope 14 can optionally be connected to either tie down ring 16 or 18.
Tie down ring 16 is fixedly secured to the head 20 of the first embodiment of the marine anchoring apparatus 22 of this invention. The head 20 is fixedly mounted to the upper end of an elongated stake 24. The preferable material for construction of the stake 24 would normally be a metallic material such as steel. Elongated stake 24 terminates in a sharply pointed lower end 26.
The tie down ring 18 is fixedly mounted on a sleeve 28 which is also fixedly mounted to the elongated stake 24. The sleeve 28 is located a spaced distance from the sharpened end 26 and also a spaced distance from the head 20. Fixedly mounted on the elongated stake 24 directly adjacent the head 20 is an upper abutment 30. Fixedly mounted on the elongated stake 24 directly adjacent the sleeve 28 is a lower abutment 32. The lower end of the sleeve 28 terminates in an annular flange 34.
Slidably mounted on elongated stake 24 in between abutments 30 and 32 is a hammer 36. The hammer 36 comprises a weighted object usually constructed of a metallic material. In order to install the marine anchoring apparatus 22 of the present invention, it is only necessary to find an appropriate location on a shore 38 and to place the sharpened end 26 in contact with the shore 38 and then repeatedly move the hammer 36 against the abutment 32 which will cause the sharpened end 26 to penetrate the shore 38 to a predetermined depth. This predetermined depth is the distance between the sharpened point 26 and the annular flange 34. Generally this distance will be in the range of a couple feet. However, it is to be considered within the scope of this invention that this distance could be increased or decreased.
Once the sharpened point 26 is installed to the desired depth, it is only necessary for the user to install the rope 14 in between the tie down rings 12, 16 and 18 as shown in FIG. 1 of the drawings. The boat 10 is now securely moored. The boat 10 may only have a single rope 14 which would be best secured to tie down ring 18 because it is lower in height and directly adjacent to the shore 38. Therefore, the force that is created by the boat against the elongated stake 24 will create less torque tending to dislodge the stake 24 than if the rope 14 is connected to the upper tie down ring 16. The upper tie down ring 16 can then be used with a separate rope (not shown) which in turn can be installed by a separate installing stake (not shown) within the shore 38 some spaced distance from the stake 24. The second rope will function as a brace tending to prevent dislodgement of the elongated stake 24 which might tend to occur if the boat 10 is subjected to windy conditions.
At times the supporting surface of the shore 38 could comprise sand or a loose particulate type of soil. In order to achieve satisfactory securement within this type of shore 38, it is advisable to use a first finned attachment 40 which is composed of three separate fins which are mounted on a sleeve 42 with these fins being equiangularly mounted on the sleeve 42. It is the purpose of the fins of the first finned attachment 40 to provide increased surface area with the shore 38, and it is this increased area that produces the securement to keep the boat 10 securely moored to the marine anchoring device 22. The sleeve 42 is to be inserted on the stake 24 in a slidable manner so as to retain its position against the annular flange 34. A fastener (not shown) is to secure the first finned attachment 40 to the annular flange 34.
The hammer 36 comprises a necked down handle grasping area 44 terminating at opposite ends in bulbous members 46. It is the bulbous members 46 that are to be impacted against the abutments 32 and 30. Typically, the weight of the hammer 36 will be two to five pounds.
The head 20 includes an elongated slot 48. The slot 48 is closed at its inner end forming closed end 60. The slot 48 provides access into an elongated chamber 50 located within the head 20. Locatable within elongated chamber 50 is the head 52 of a threaded fastener 54. The threaded portion of the fastener 54 is to pass through the slot 48 and securely engage with the upper end of a tent stake 56. The lower end of the tent stake 56 is formed into a sharpened point 58. It is to be understood that the tent stake 56 can normally be constructed of a metallic material similar to the elongated stake 24.
With the head 52 slidingly received within elongated chamber 50 with the threaded end 54 located directly in contact with the closed end 60 of the slot 48, the longitudinal center axis of the tent stake 56 will be in alignment with the longitudinal center axis of the elongated stake 24. The sharpened point 58 is to be located against the supporting surface 60 which generally will comprise soil. The user then grasps the necked down area 44 of the hammer 36 and repeatedly impacts the appropriate bulbous member 36 against the abutment 30. This will cause the tent stake 56 to be driven into the ground 61 as is depicted within FIG. 7 of the drawings. A tie down rope 62 of a tent 64 is to be attached to the tent stake 56.
The first embodiment of the marine anchoring apparatus 22 can be used in hard packed soil and even through asphalt. To extract the stakes 24 and 56, it is only necessary to use the hammer 36 in the reverse direction impacting abutment 30. The head 20 is shown in transverse cross section to be circular.
Referring particularly to FIGS. 10 to 16 of the drawings there is shown the second embodiment of the anchoring apparatus 66 of this invention. The second embodiment anchoring apparatus 66 is basically similar to the first embodiment 22 in that there is a head 68, a stake 70 which terminates in a sharply pointed end 72. Mounted on the stake 70 is an upper abutment 74 and a lower abutment 78. Fixedly mounted on the stake 24 between the upper abutment 74 and the head 68 is an upper sleeve 82. Fixedly mounted on the upper sleeve 82 is a first tie down ring 76. Fixedly on the stake 20 directly adjacent the lower abutment 78 is a lower sleeve 84. Fixedly mounted on the lower sleeve 84 is a second tie down ring 80.
The differences between the second embodiment 66 versus the first embodiment 22 is that the tie down rings 76 and 80 extend in opposite directions from each other. The reason for this is generally a tie down rope 92 is connected to the second tie down ring 80 with this rope 92 being connected to a boat or other type of marine vehicle. A separate rope 90 is connected to the tie down ring 76 which extends in an opposite direction from the rope 92. The rope 90 is to be connected to a bracing structure such as another stake that would be driven into the ground some spaced distance from the position of the stake 70. In this way the second embodiment 66 is braced by the rope 90.
Another difference of the second embodiment 66 from the first embodiment 22 is that the head 68, in transverse cross section, is not round, but is actually square. Any polygonal shape would be satisfactory. The reason for making the head 68 of a polygonal shape is to facilitate its connection with an installation of a tent stake which will be explained further on in the specification.
The slide hammer 98 is mounted on the stake 70. The slide hammer 98 is movable between the solid line position and the dotted line position shown in FIG. 10. It has been discovered that a user may possibly cause a finger to be located within the impacting area when using a hammer 98. To avoid possible injury to the user, the necked down area of the hammer 98 is covered with a resilient cover 86 which will normally be of a fabric such as a canvas material. The resilient cover 86 is tightly held in position on the hammer 98 by means of a hook and loop type of fastener 88 (trade name "VELCRO"). The cover 86 also includes a handle strap 94. The handle strap 94 is located so that automatically upon the placing of one's hand in conjunction with the hammer 98 that the hand will be confined by the handle strap 94. This handle strap 94 will thereby prevent any portion of the hand coming into contact with the impact area, hence preventing injury. Also, the fact that the grabbing surface of the hammer 98 includes a soft resilient covering makes it far more comfortable to use the hammer 98.
Fixedly mounted on the stake 70 located directly adjacent the tie down ring 80 is a flange 96. Mounted within the flange 96 is a hole 100. A second finned attachment 102 can be located in conjunction with the stake 70 with the flange 108 of, the second finned attachment 102 being placed directly against the flange 96. Within the flange 108 is located a hole 110. A bolt fastener 112 can be mounted between holes 100 and 110 when they are aligned with the wing nut 114 engaging with the bolt fastener 112. This will result in securely locking together the second finned attachment 102 and the flange 96. It is to be deemed optional to use the bolt fastener 112 as it is not necessary to lock together the second finned attachment 102 and the flange 96 to merely embed the second finned attachment 102 within the ground. The second finned attachment 102 is designed to be used in conjunction with loose soil. When soil is harder, then it would not be necessary to use at all the second finned attachment 102.
The second finned attachment 102 includes two in number of fins 104 and 106. It is to be noted that these fins are located about 120 degrees apart. In comparing the second finned attachment 102 with the first finned attachment used in conjunction with the first finned attachment 40 specifically shown in FIGS. 5 and 6, it can be seen that the primary difference is that the second finned attachment 102 uses only two fins where the first finned attachment 40 uses three in number of fins. It has been discovered that the third fin actually does nothing in providing of lateral support. The fins 104 and 106 are to be located so that such face toward the pulling force. In other words, the fins 104 and 106 should not be located as shown in FIG. 13 but actually located so such face tie down ring 80. When such face the tie down ring 80, the hole 110 will align with hole 100.
The second finned attachment 102 includes a center through opening 116. It is within this center through opening 116 that the stake 70 is located in order to effect the installation of the second finned attachment 102 within the loose soil. It is to be understood that this installation is caused by repeatedly moving and causing the hammer 98 to strike against lower abutment 78.
Once the second finned attachment 102 is installed within the ground, the flange 108 should be located at about the surface 162 of the ground. The stake 70 can then be removed and an attaching stake 118 then mounted in conjunction with the through opening 116 with the tip of the attaching stake 118 occupying the hole that was formed within the ground by the stake 70. In this particular position the flange 120 of the attaching stake 118 will abut against the flange 108. Flange 120 is to include a hole 122. This hole 122 can align with the hole 110 with the bolt fastener 112 with wing nut 114 being used to lock together the attaching stake 118 and the second finned attachment 102. Mounted on the flange 120 is a tie down ring 124. This attaching stake 118 is used in lieu of the anchoring apparatus 66 after the second finned attachment 102 is installed within the ground. This will eliminate possible theft of the anchoring apparatus 66. Theft of the attaching stake 118 could occur. However, the attaching stake 118 should have little use by itself to any thief without the anchoring apparatus 66. The attaching stake 118 can be driven into the ground if necessary by the hammer 98 and stake 70.
When the ground comprises sand, it is desirable to utilize a third finned attachment 126. The third finned attachment 126 is to be connected in the same manner with the anchoring apparatus 66 and installed in the same manner by being embedded within the ground. The third finned attachment 126 includes two in number of fins 128 and 130 which again are located 120 degrees apart. Mounted on the elongated stake member 131 of the third finned attachment 126 is a flange 122. The elongated stake member 131 terminates in its bottom end into a flattened tip 134. A sharp point is not necessary as this third finned attachment 126 is being driven into sand or exceedingly loose soil. The attaching stake 118 is to be utilized and locked in conjunction with the third finned attachment 126 in the same manner as previously discussed in relation to second finned attachment 102. It is to be noted that the length of the elongated stake 131 will be greater in length than the portion of the stake 70 that extends beneath the flange 96. This relationship is clearly shown in FIG. 17.
If necessary, the entire stake 70 and hammer 98 could be used as a driver (not just the hammer 98). The user would locate hammer 98 against lower abutment 78 with one hand and then with the other hand grab head 68. The user would then lift and lower stake 70 and hammer 98 causing flange 96 to impact flange 108 on flange 132. The advantage is that instead of using three or four pounds as the driving force there is being used about thirteen pounds which certainly more quickly installs attachments 102 or 126.
Referring particularly to FIGS. 19 to 22, there is shown a tent stake 136. The tent stake 136 has an elongated body 138 which terminates in a lower sharpened point 140. The upper end of the body 138 is integrally connected to a polygonal shaped head 142. The head 142 is actually formed by a rod which is bent in a manner to produce a polygonal shaped opening 144. The head 68 is locatable in a close fitting manner within the opening 144, as is depicted in FIGS. 19 and 20 of the drawings. The body 138 is oriented to be somewhat aligned with the stake 70 but with the body 138 extending in the opposite direction from the stake 70. The hammer 98 is then moved against the upper abutment 74 to cause the body 138 to penetrate the ground as is clearly shown in FIG. 22. Once the tent stake 136 is installed, a rope 146 is to be attached to the polygonal head 142 with the rope 146 being connected to a wall of a tent 148. The tent stake 135 includes a flange 150 which abuts against the head 68 as the tent stake 136 is being installed within the ground.
The head 68 may include a V-shaped slot 152. The head 68 also includes a through opening 154. The purpose of the V-shaped slot 152 is to remove nail types of fasteners by locating of the head of the nail type fastener (not shown) within the through opening 154 with the sidewall of the V-shaped slot 152 engaging with the sidewalls of the nail type of fastener. By moving of the anchoring apparatus 66 in a manner similar to a conventional crowbar, the nail can then be removed.
Arrow 156 is shown in FIGS. 10 and 12 to depict the extent of movement of the slide hammer 98. Arrow 158 is shown in FIG. 17 to again depict the length of movement of the slide hammer 98. Arrow 160 is shown in FIG. 19 to depict the extent of movement of the slide hammer 98. | An elongated stake having a sharply pointed lower end and a polygonal shaped upper end. A hammer is slidably mounted on the stake and is limited in its travel by an upper abutment located at the upper end and a lower abutment located about midway between the upper end and the lower end. Mounted at the upper end is a first tie down ring with a second tie down ring being mounted at the lower abutment with these tie down rings facing in opposite directions. Repeatedly impactingly moving of the hammer against the lower abutment will result in the lower end of the stake to be driven into a supporting surface. A resilient cover is mounted about the hammer which includes a strap to enclose the user's hand preventing injury to the user during hammer usage. A separate tent stake is to be engageable with the upper end and repeated impacting movements of the hammer against the upper abutment is to result in driving of the tent stake into a supporting surface. | 4 |
CLAIM OF PRIORITY
[0001] This application makes reference to, incorporates the same herein, and claims all benefits accruing under 35 U.S.C. §119 from an application earlier filed in the Korean Intellectual Property Office on the 16 th of Feb. 2010 and there duly assigned Serial No. 10-2010-0013843.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a printer and a printing method, and more particularly, to a printer and a printing method for reducing a deviation between nozzles.
[0004] 2. Description of the Related Art
[0005] Generally, a display device converts data processed by a data processing device into an image. Examples of the display device include a liquid crystal display (LCD) device, an organic electroluminescent (EL) display device, and a plasma display panel (PDP). Such display devices are flat display devices which have smaller volume and weight than cathode-ray tube display devices.
[0006] The flat display devices commonly have a pixel pattern for displaying an image. For example, the LCD device includes various pixel patterns, such as a thin film transistor (TFT), a gate signal line, a data signal line, a pixel electrode, a black matrix, a color filter, and a common electrode. For example, the organic EL display device includes various pixel patterns, such as an anode electrode, an electron injection layer (EIL), a hole injection layer (HIL), a cathode electrode, and an organic layer.
SUMMARY OF THE INVENTION
[0007] The present invention provides a printer and a printer method for reducing a deviation between nozzles during printing.
[0008] According to an aspect of the present invention when a printhead including a first end and a second end sequentially prints a first area and a second area which are adjacent to each other, the printing method comprises the step of performing printing by relatively moving locations of the printhead and a print object in such a way that a surface printed by the second end in the first area and a surface printed by the second end in the second area face each other.
[0009] When the location of the printhead with respect to the print object switches from the first area to the second area, the printhead may rotate with respect to the print object.
[0010] The printhead may rotate around at least one point on the printhead constituting a rotation axis. The printhead may rotate around one end of the printhead constituting the rotation axis. The printhead may rotate around the center of the printhead constituting the rotation axis. The printhead may rotate around both ends of the printhead constituting the rotation axis.
[0011] A method of adjusting the locations of the printhead and the print object may comprise moving the print object with respect to the printhead.
[0012] A method of adjusting the locations of the printhead and the print object may comprise moving the printhead in parallel with the print object.
[0013] The printing method may be an inkjet printing method.
[0014] The printing method may be a nozzle printing method.
[0015] The printhead may spray a light emitting material so as to form a light emitting unit. The printhead may spray a pigment of a color filter layer so as to form a color filter layer. The printing method may be performed by using a plurality of the printheads, each spraying a pigment of a single color.
[0016] The printhead may be formed so as to tilt at a predetermined angle with respect to a moving direction of the print object on a print surface.
[0017] With respect to the print object, the printing method may further include: performing printing while moving the printhead in a first direction; moving the printhead in a second direction; rotating the printhead; performing printing while moving the printhead in a direction opposite to the first direction; moving the printhead in the second direction; and rotating the printhead.
[0018] The printing method may further include: performing printing while moving the print object in a direction opposite to a first direction with respect to the printhead; moving the print object in a direction opposite to a second direction; rotating the printhead; performing printing while moving the print object in the first direction with respect to the printhead; moving the print object in the direction opposite to the second direction; and rotating the printhead.
[0019] When the location of the printhead with respect to the print object switches from the first area to the second area, the printing method may further include controlling a location of the printhead so as to start printing in the second area, wherein the controlling of the location comprises: receiving the location of the printhead with respect to the print object, the location being received by a vision camera; and compensating the location of the printhead.
[0020] According to another aspect of the present invention, when a printhead including a first end and a second end sequentially prints a first area and a second area which are adjacent to each other, the printer performs printing by relatively moving locations of the printhead and a print object in such a way that a surface printed by the second end in the first area and a surface printed by the second end in the second area face each other.
[0021] When the location of the printhead with respect to the print object switches from the first area to the second area, the printhead may rotate with respect to the print object.
[0022] The printhead may rotate around at least one point on the printhead constituting a rotation axis. The printhead may rotate around one end of the printhead constituting the rotation axis. The printhead may rotate around the center of the printhead constituting the rotation axis. The printhead may rotate around both ends of the printhead constituting the rotation axis.
[0023] The printhead may include a plurality of nozzles.
[0024] The printer may perform printing using an inkjet printing method.
[0025] The printer may perform printing using a nozzle printing method.
[0026] When the location of the printhead with respect to the print object switches from the first area to the second area, the printer may further include a control system for controlling a location of the printhead to start printing in the second area, wherein the control system may include: a vision camera for receiving the location of the printhead with respect to the print object; and a compensator for compensating the location of the printhead.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] A more complete appreciation of the invention, and many of the attendant advantages thereof, will be readily apparent as the same becomes better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings, in which like reference symbols indicate the same or similar components, wherein:
[0028] FIG. 1 is a conceptual schematic diagram illustrating movement of a printhead moving with respect to a print object according to a parallel movement when viewed from above according to an embodiment of the present invention;
[0029] FIG. 2 is a conceptual schematic diagram illustrating a printhead switching from a first area to a second area according to a rectilinear movement and a rotary movement according to an embodiment of the present invention;
[0030] FIG. 3 is a diagram comparing discharge rates in a cross-section taken along a line III-III of FIG. 1 and a cross-section taken along a line III-III of FIG. 2 ;
[0031] FIG. 4 is a conceptual schematic diagram illustrating movement of a printhead on a print object when viewed from above according to a modified example of the embodiment of FIG. 2 ;
[0032] FIG. 5 is a schematic perspective view illustrating a printer having a printhead moving with respect to a print object;
[0033] FIG. 6 is a flowchart of movement of the printhead of FIG. 5 ;
[0034] FIG. 7 is a schematic perspective view illustrating a print object in a parallel movement and a printer including a printhead in a rotary movement;
[0035] FIG. 8 is a flowchart of movements of the print object and the printhead of FIG. 7 ;
[0036] FIG. 9 is a schematic perspective view illustrating the printhead of FIG. 5 for describing location compensation of the printhead;
[0037] FIG. 10 is a flowchart of movement and location compensation of the printhead of FIG. 9 ;
[0038] FIG. 11 is a conceptual schematic diagram illustrating movement of a printhead on a print object when viewed from above according to another modified example of the embodiment of FIG. 2 ;
[0039] FIG. 12 is a conceptual schematic diagram illustrating movement of a printhead on a print object when viewed from above according to another modified example of the embodiment of FIG. 2 ;
[0040] FIG. 13 is a conceptual schematic diagram illustrating movement of a printhead on the print object when viewed from above according to another example of the embodiment of FIG. 2 ;
[0041] FIG. 14 is a conceptual schematic diagram illustrating movement of a printhead on a print object when viewed from above according to another example of the embodiment of FIG. 2 ; and
[0042] FIG. 15 is a conceptual schematic diagram illustrating a plurality of printheads used to print red, green, and blue, respectively, on a print object when viewed from above according to the embodiment of FIG. 2 .
DETAILED DESCRIPTION OF THE INVENTION
[0043] Hereinafter, the present invention will be described more fully with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown.
[0044] FIG. 1 is a conceptual schematic diagram illustrating movement of a printhead moving with respect to a print object according to a parallel movement when viewed from above according to an embodiment of the present invention.
[0045] Referring to FIG. 1 , the print object 1 includes a first area and a second area. The printhead H 1 may print the first area while rectilinearly moving in a direction opposite to a Y-axis direction. After printing the first area, the printhead H 1 moves below the print object 1 so as to move to the second area, and then moves to the second area in parallel with an X-axis. After moving to the second area in parallel with the X-axis, the printhead H 1 prints the second area while rectilinearly moving in the Y-axis direction. Here, the printhead H 1 may include a plurality of nozzles. For example, in FIG. 1 , the printhead H 1 includes a total of 6 nozzles, namely from a first nozzle N 1 through a sixth nozzle N 6 .
[0046] The number and locations of the nozzles on the printhead H 1 are not limited to the embodiment of FIG. 1 , and may vary.
[0047] According to the current embodiment of the present invention, the first area is sequentially printed in the X-axis direction from the first nozzle N 1 to the sixth nozzle N 6 , and the second area is also sequentially printed in the X-axis direction from the first nozzle N 1 to the sixth nozzle N 6 . Accordingly, adjacent surfaces of the first and second areas are printed by using different nozzles.
[0048] In other words, referring to FIG. 1 , the adjacent surfaces of the first and second areas are respectively printed by the sixth nozzle N 6 and the first nozzle N 1 .
[0049] At this point, since the printhead H 1 includes the plurality of nozzles N 1 through N 6 , there may be a deviation between nozzles due to different discharge rates, or the like. Such a deviation may occur irregularly or regularly, and if the deviation occurs gradually, a difference between accumulated discharge rates of the first and sixth nozzle N 1 and N 6 , respectively, may be higher than a difference between discharge rates of the adjacent first and second nozzles N 1 and N 2 , respectively. Such a discharge rate deviation between the first and sixth nozzles N 1 and N 6 , respectively, eventually generates a light emitting deviation which is easily perceived.
[0050] In order to decrease a deviation between nozzles, when a printhead H 2 including a first end and a second end sequentially prints a first area and a second area, locations of the printhead H 2 and the print object 1 may be adjusted in such a way that a surface printed by the second end in the first area and a surface printed by the second end by the second area face each other.
[0051] FIG. 2 is a conceptual schematic diagram illustrating the printhead switching from the first area to the second area according to a rectilinear movement and a rotary movement according to an embodiment of the present invention.
[0052] Referring to FIG. 2 , the printhead H 2 includes a first end where a first nozzle N 1 is located and a second end where a sixth nozzle N 6 is located. When the printhead H 2 sequentially prints the first area and the second area, the printhead H 2 may be rotated so that the surface printed by the second end, where the sixth nozzle N 6 is located, in the first area and the surface printed by the second end, where the sixth nozzle N 6 is located, in the second area face each other.
[0053] As shown in FIG. 2 , the printhead H 2 may be rotated based on a predetermined point so that adjacent surfaces of the first and second areas are printed by the same nozzle. Here, a surface printed by the second end denotes a surface on the first or second area which is printed by the second end. Similarly, a surface printed by the first end denotes a surface on the first or second area which is printed by the first end.
[0054] The effect of printing adjacent surfaces by using the same nozzle as shown in FIG. 2 will now be described with reference to FIG. 3 .
[0055] FIG. 3 is a diagram comparing discharge rates in a cross-section taken along a line III-III of FIG. 1 and a cross-section taken along a line III-III of FIG. 2 .
[0056] FIG. 3 illustrates a first straight line I showing discharge rates of the nozzles N 1 thru N 6 of FIG. 1 and a second straight line II showing discharge rates of the nozzles N 1 thru N 6 of FIG. 2 . Here, it is assumed that the discharge rates of the first and sixth nozzles N 1 and N 6 , respectively, of the printhead H 1 or H 2 are different from each other by Δx. In addition, looking at the first straight line I, the difference between the discharge rates is Δx at each adjacent point A.
[0057] On the other hand, looking at the second straight line II, there is no difference between the discharge rates at each adjacent point B, and only a deviation Δn between adjacent nozzles gradually occurs. Accordingly, a printing method or a printer may use the printhead H 2 having the deviation Δn to reduce a deviation between nozzles on adjacent surfaces by printing the adjacent surfaces by using the same nozzle.
[0058] When a printhead including a first end and a second end sequentially prints a first area and a second area, a printing method according to an embodiment of the invention includes performing printing by adjusting locations of the printhead and a print object in such a way that a surface printed by the second end in the first area and a surface printed by the second end in the second area face each other, and this method will now be described with reference to FIGS. 4 thru 6 .
[0059] FIG. 4 is a conceptual schematic diagram illustrating movement of a printhead on a print object when viewed from above according to a modified example of the embodiment of FIG. 2 , FIG. 5 is a schematic perspective view illustrating a printer having the printhead moving with respect to the print object, and FIG. 6 is a flowchart of movement of the printhead of FIG. 5 .
[0060] Referring to FIG. 4 , the printhead H 3 may sequentially include first thru sixth nozzles N 1 thru N 6 , respectively, arranged in a direction from a first end to a second end. Here, in operation S 110 of FIG. 6 , the printhead H 3 may move in a direction opposite to a Y-axis direction while printing the first area. Then, the printhead H 3 may move along an X-axis direction in operation S 120 . Next, the printhead H 3 may rotate based on one point on the printhead H 3 as a central axis P 1 in operation S 130 . For example, the central axis P 1 may be the center of the printhead H 3 , as shown in FIG. 4 . The printhead H 3 , which is rotated based on the central axis P 1 , may print the second area while moving in the Y-axis direction in operation S 140 . When the second area is printed as such, a deviation between the adjacent surfaces of the first and second areas due to different discharge rates is reduced since the adjacent surfaces are printed by the sixth nozzle N 6 . When the printhead H 3 passes through the print object 1 in the Y-axis direction after printing the second area, the printhead H 3 may move in the X-axis direction in operation S 150 . The printhead H 3 may then rotate based on the central axis in operation S 160 .
[0061] Next, operations S 110 thru S 160 of FIG. 6 may be repeated so as to print the print object 1 . In other words, the printhead H 3 may print a third area while moving in the direction opposite to the Y-axis direction. Here, as shown in FIG. 4 , adjacent surfaces of the second and third areas are printed by the first nozzle N 1 , and thus there is no deviation between nozzles in each area. Such a printing method may be performed by the printer 100 of FIG. 5 , wherein the print object 1 is fixed, and the printhead H 3 moves along the X-axis or the Y-axis with respect to the print object 1 or rotates based on the central axis P 1 . However, the device for performing the printing method of FIG. 4 is not limited to the printer 100 .
[0062] A modified example of the printer 100 will now be described with reference to FIGS. 7 and 8 .
[0063] FIG. 7 is a schematic perspective view illustrating a printer which moves a print object in a straight line or rotates a printhead based on a central axis, and FIG. 8 is a flowchart of movements of the print object and the printhead of FIG. 7 .
[0064] The printer 200 of FIG. 7 is configured to move the print object 1 in a straight line and rotate the printhead H 3 based on the central axis P 1 . In order to print a first area of the print object 1 , the print object 1 may move in a Y-axis direction in operation S 210 . Then, the print object 1 may move in a direction opposite to an X-axis direction in operation S 220 . Next, the printhead H 3 may rotate based on the central axis P 1 in operation S 230 . Then, the print object 1 may move in a direction opposite to the Y-axis direction while the printhead H 3 prints a second area in operation S 240 . Next, the print object 1 may move in a direction opposite to the X-axis direction so as to print a third area in operation S 250 . Then, the printhead H 3 may be rotated in operation S 260 . Operations S 210 thru S 260 of FIG. 8 may be repeated to print the print object 1 . In other words, the printhead H 3 may print the third area while moving the print object 1 in the Y-axis direction.
[0065] The structure of the printer 100 or 200 and the printing method are not limited thereto. For example, the printer 100 may adjust a relative distance between the printhead H 3 and the print object 1 by fixing the printhead H 3 and moving the print object 1 in a straight line and rotating the print object 1 based on the central axis P 1 . Alternatively, the relative distance between the printhead H 3 and the print object 1 may be adjusted by moving the printhead H 3 and the print object 1 in a straight line and rotating the printhead H 3 and the print object 1 based on the central axis P 1 . Alternatively, the printer 100 may adjust a relative distance between the printhead H 3 and the print object 1 by fixing the printhead H 3 and moving the print object 1 along a direction perpendicular to printhead.
[0066] A control system for compensating for the location of the printhead H 3 by compensating a rotation angle θ of the printhead H 3 may be used to precisely adjust a relative distance between the printhead H 3 and the print object 1 while changing locations of the nozzles N 1 thru N 6 by rotating the printhead H 3 . Location compensation of the printhead H 3 will now be described with reference to FIGS. 9 and 10 .
[0067] FIG. 9 is a schematic perspective view illustrating the printhead of FIG. 5 for describing location compensation of the printhead, and FIG. 10 is a flowchart of movement and location compensation of the printhead of FIG. 9 .
[0068] When the location of the printhead H 3 switches from a first area to a second area with respect to the print object 1 , the control system controls a location of the printhead H 3 so as to start printing on the second area. Here, the current embodiment of the present invention is described in the situation where the printhead H 3 switches from the first area to the second area, but the invention is not limited thereto, and the printhead H 3 may switch to any adjacent area. Referring to FIG. 9 , the printhead H 3 includes a vision camera C. Also, since an align mark M is marked on the print object 1 or a surrounding stage, the vision camera C may read the align mark M and adjust the rotation angle θ of the printhead H 3 so as to compensate for the location of the printhead H 3 . Accordingly, the control system may receive the location of the printhead H 3 with respect to the print object 1 (operations S 231 and S 261 of FIG. 10 ), and compensate for the location of the printhead H 3 (operations S 232 and S 262 ). Since operations S 231 and S 232 , and operations S 261 and S 262 , are performed before moving the printhead H 3 along a Y-axis direction after rotating the printhead H 3 , operations S 231 and S 232 , and operations S 261 and S 262 , may be performed between rotation of the printhead H 3 and movement of the print object in the Y-axis direction, as illustrated in the flowchart of FIG. 8 . In other words, referring to FIG. 10 , in order to print the first area of the print object 1 , the print object 1 may move in a Y-axis direction in operation S 210 . Then, the print object 1 may move along a direction opposite to an X-axis direction in operation S 220 . Next, the printhead H 3 may be rotated based on a central axis P 1 in operation S 230 . Then, the location of the printhead H 3 with respect to the print object 1 may be received in operation S 231 . Next, the location of the printhead H 3 may be compensated for in operation S 232 . Then, the second area may be printed while moving the print object 1 in a direction opposite to the Y-axis direction in operation S 240 . Next, in order to print a third area, the print object 1 may be moved in the direction opposite to the X-axis direction in operation S 250 . Then, the printhead H 3 may be rotated in operation S 260 . Next, the location of the printhead H 3 with respect to the print object 1 may be received in operation S 261 . Then, the location of the printhead H 3 may be compensated for in operation S 262 . Next, operations S 210 thru S 262 of FIG. 10 may be repeated so as to print the print object 1 . In other words, the third area may be printed while moving the print object 1 in the Y-axis direction.
[0069] FIGS. 11 thru 14 are various modified examples of FIG. 2 .
[0070] In FIGS. 11 thru 14 , a print object 1 is fixed and a print head H 4 , H 5 , H 6 , or H 7 is moved, but an embodiment of the present invention is not limited thereto, and at least one of the print object 1 and the print head H 4 , H 5 , H 6 , or H 7 may be moved. In other words, the print object 1 may move in a straight line and the print head H 4 , H 5 , H 6 , or H 7 may rotate based on the central axis P 1 , or both the print object 1 and the print head H 4 , H 5 , H 6 , or H 7 may move in a straight line and rotate based on the central axis P 1 . Also, when the print head H 4 , H 5 , H 6 , or H 7 or the print object 1 rotates, a location of the print head H 4 , H 5 , H 6 , or H 7 may be additionally compensated as described with reference to FIGS. 9 and 10 .
[0071] FIG. 11 is a conceptual schematic diagram illustrating movement of the printhead on the print object when viewed from above according to another modified example of the embodiment of FIG. 2 .
[0072] Referring to FIG. 11 , the printhead H 4 includes first thru sixth nozzles N 1 thru N 6 , respectively, a first rotation axis P 2 on a first end of the printhead H 4 where the first nozzle N 1 is located, and a second rotation axis P 3 on a second end where the sixth nozzle N 6 is located. A first area may be printed while moving the printhead H 4 in a direction opposite to a Y-axis direction. Then, the printhead H 4 may be rotated based on the second rotation axis P 3 . Next, a second area may be printed while moving the printhead in the Y-axis direction. Then, the printhead H 4 may be rotated based on the first rotation axis P 2 . Next, a third area may be printed while moving the printhead H 4 in the direction opposite to the Y-axis. Such processes may be repeated so as to print the print object 1 .
[0073] FIG. 12 is a conceptual schematic diagram illustrating movement of the printhead on a print object when viewed from above according to another modified example of the embodiment of FIG. 2 .
[0074] Referring to FIG. 12 , the printhead H 5 includes first thru sixth nozzles N 1 through N 6 , respectively, and a first rotation axis P 2 on a first end of the printhead H 5 where the first nozzle N 1 is located. A first area may be printed while moving the printhead H 5 in a direction opposite to a Y-axis direction. Then, the printhead H 5 may be rotated based on the first rotation axis P 2 . Here, the printhead H 5 may rotate clockwise or counterclockwise. Next, the printhead H 5 may move in an X-axis direction. Then, a second area may be printed while moving the printhead H 5 in the Y-axis direction. Next, the printhead H 5 may again be rotated based on the first rotation axis P 2 . Here, the printhead H 5 may not move in the X-axis direction, and a third area may be printed while again moving the printhead H 5 in the direction opposite to the Y-axis direction. The print object 1 may be printed by repeating the above processes. The printhead H 4 of FIG. 11 includes two rotation axes P 2 and P 3 , whereas the printhead H 5 of FIG. 12 includes one rotation axis P 2 to change directions.
[0075] FIG. 13 is a conceptual schematic diagram illustrating movement of the printhead on the print object when viewed from above according to another example of the embodiment of FIG. 2 .
[0076] Referring to FIG. 13 , the printhead H 6 includes first thru sixth nozzles N 1 through N 6 , respectively, and a second rotation axis P 3 on a second end of the printhead H 6 where the sixth nozzle N 6 is located. A first area may be printed while moving the printhead H 6 in a direction opposite to a Y-axis direction. Then, the printhead H 6 may be rotated based on the second rotation axis P 3 . Next, a second area may be printed while moving the printhead H 6 in the Y-axis direction. Then, the printhead H 6 may be rotated again based on the second rotation axis P 3 . Next, the printhead H 6 may be moved in the X-axis direction so as to adjust alignment of the printhead H 6 and the print object 1 . Then, a third area may be printed while moving the printhead H 6 in the direction opposite to the Y-axis direction. The print object 1 may be printed by repeating the above processes.
[0077] FIG. 14 is a conceptual schematic diagram illustrating movement of the printhead on the print object when viewed from above according to another example of the embodiment of FIG. 2 .
[0078] FIG. 14 shows that the printhead H 7 may tilt in any direction. For example, the printhead H 2 of FIG. 2 may have a high right and a low left with respect to a moving direction, and the printhead H 7 of FIG. 14 may have a low right and a high left with respect to a moving direction.
[0079] The print object 1 to be printed according to the printing methods and the printers 100 and 200 of FIGS. 2 thru 14 is not limited, and any printable object may be used. For example, the print object 1 may be a substrate 10 , including a plurality of pixel regions PR.
[0080] A method of printing the substrate 10 will now be described with reference to FIG. 15 .
[0081] FIG. 15 is a conceptual schematic diagram illustrating a plurality of printheads used to print red (R), green (G), and blue (B), respectively, on a print object when viewed from above according to the embodiment of FIG. 2 .
[0082] The plurality of pixel regions PR may be formed in a matrix on the substrate 10 . A pixel pattern may be formed in the pixel region PR so as to display an image. For example, when the resolution of the substrate 10 is 1024×768, about 1024×768×3 pixel regions PR may be formed on the substrate 10 . Here, each pixel region PR may be filled with a light emitting material of R, G, or B. In addition, the printhead H 8 may spray the light emitting material of R. Also, the printhead H 9 may spray the light emitting material of G, and the printhead H 10 may spray the light emitting material of B. Here, the printheads H 8 , H 9 , and H 10 may form a color filter by respectively spraying an R color filter material, a G color filter material, and a B color filter material, wherein the R, G, and B color filter materials each emit a single color light by filtering a white light.
[0083] The printing method may be an inkjet printing method or a nozzle printing method.
[0084] According to the embodiments of the present invention, a light emitting deviation is reduced by reducing a deviation between nozzles during printing.
[0085] While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the present invention as defined by the following claims. | A printing method and a printer for implementing the printing method are disclosed. When a printhead including a first end and a second end sequentially prints a first area and a second area which are adjacent to each other, the method comprises performing printing by means of the printer by relatively moving locations of the printhead and a print object in such a way that a surface printed by the second end in the first area and a surface printed by the second end in the second area face each other. The printhead rotates around a rotational axis comprising at least one point on the printhead, one end of the printhead, a center of the printhead, or both ends of the printhead. | 1 |
FIELD OF THE INVENTION
[0001] The present invention relates to x-rays production. More specifically, the present invention is concerned with a method and system for generating microfocused laser-based x-rays suitable for mammography
BACKGROUND OF THE INVENTION
[0002] Mammographic signs of early cancer include calcifications, small masses (densities), neo-densities and architectural distortions. Screening mammography aims at revealing these signs and is highly sensitive and specific. However, still a notable fraction of mammography produces false positive or false negative results These outcomes most occur in the thick and/or dense breast. False positive results may result in an unnecessary additional imaging and biopsy. False negative results, which occur sometimes even when a cancer is palpable, have a severe adverse effect due to delayed biopsy and delayed cancer diagnosis.
[0003] Presence of calcifications usually helps to detect breast pathology. Although calcifications demonstrate well-pronounced contrast in mammograms, their detection threshold size is a function of x-ray tube focal spot size, radiographic technique factors including radiation quality, signal-to-noise ratio and exposure time, as well as function of detector and display devices. Even though, in early stages of breast disease microcalcifications are present in approximately half of the cases, they are not apparent on regular screening mammographs before reaching the detection threshold size, which is typically around 100 μμm. This especifically applies to punctuate calcifications
[0004] Some of the inherent limitations of the x-ray tube based screen-film mammography include:
[0005] relatively large focal spot (typically nominal ˜100 μm);
[0006] varying effective focal spot size across the imaged breast;
[0007] suboptimal (below 13 lp/mm) spatial resolution in the upper quadrants for breast thickness above 6 cm:
[0008] off-focal radiation;
[0009] a relatively low output (especially with microfocus);
[0010] a suboptimal spectral characteristic of x-rays for imaging dense fibroglandular tissue and/or thick breast;
[0011] restricted latitude of film-screen mammography, and
[0012] restricted contrast of film-screen mammography.
[0013] Regarding the two last restrictions, film-screen mammography utilizes film as a recording medium to properly record and display relatively narrow dynamic range of x-ray exposures. This should be contrasted with specially designed detectors that can correctly record four orders of magnitude of x-ray exposure. This information can be subsequently displayed on specially designed monitors. Moreover, since film-screen mammography aims at obtaining very high contrast images, the slope of the optical density/x-ray exposure curve is very high. As a result, only a very limited range of x-ray exposure is acceptable If exposure is too high or too low, it will produce exceedingly high or low optical density thus rendering the image not useful clinically.
[0014] While the two last restrictions can be alleviated to a great extent by digital mammography, the other limitations stem from the inherent limitations of x-ray tube and are unlikely to be overcome in the framework of this technology.
[0015] New technology for generating x-rays had emerged in recent years It relies on emission of x-rays from laser-produced plasma (LPP). This phenomenon occurs when a visible or infrared laser beam is focused onto the surface of solids or liquids If the optical power density exceeds a material dependent threshold value, continuous bremsstrahlung and characteristic x-ray emission lines result. However, initially very expensive and large laser systems were required to obtain the required optical power and the LPP x-ray sources were rather large (100 μm-1 mm). The invention of chirped-pulse amplification (CPA) in the late 1980's allowed achievement of high optical power density delivered to the target by the laser beam from compact and significantly cheaper table-top terawatt ultra-fast lasers.
[0016] The feasibility of CPA lasers for mammography and angiography has been demonstrated in both “High Magnification Imaging With a Laser-Based Hard X-ray Source”, IEEE Journal of selected topics in Quantum Electron, Special issue on laser in medicine, 5, 911-915 (1999), by J. Yu, Z. Jiang, J. C. Kieffer, A. Krol. and “Laser-Based microfocused X-ray Source for Mammography faisability Study”, Journal of Medical Physics, 24, 725-732 (1997), by A. Krol, A. Ikhlef, J C Kieffer, D. Bassano, C. C. Chamberlain, Z Jiang, H. Pepin, S. C. Parsad. Data in these publications shows the ability to obtain focal spot size of the order of 10 μm necessary to perform high spatial resolution mammographic imaging and confirm system ability to produce x-ray spectra from a number of different target materials, including Mo, Rh, Ag, In and, Sn with characteristic emission energies spanning 17 3 keV to 28.5 keV.
[0017] Even though LLP x-ray source created by CPA lasers can be very small (10 μm or less) and bright, with peak power many order of magnitude higher than conventional x-ray tubes, a drawback of CPA laser sources from the prior art has been their low average power However, in recent years, significant progress has been made in this respect 20 W average power CPA lasers are presently available, and a 50 W CPA laser is in the design stage
[0018] Finally, there have been studies on sub-picosecond laser-solid-matter interaction devoted to investigation of x-rays generation, from the soft x-rays up to the very hard x-ray emission in the MeV range. However, nobody attempted to simultaneously control the emitted x-ray spectrum, the x-ray source size and conversion efficiency from laser to x-rays.
[0019] Method and system for generating microfocused laser-based x-rays allowing to simultaneously optimize the x-ray source size, its spectral distribution, and the conversion efficiency in the 17 3-28.5 keV range is thus desirable.
SUMMARY OF THE INVENTION
[0020] An object of the present invention is therefore to provide an improved system and a method for generating microfocused laser-based x-rays.
[0021] Specifically an object of the present invention is to provide such method and system allowing optimizing the x-ray source size, its spectral distribution, and the conversion efficiency in the 17.3-28 5 keV range (adapted to the breast thickness and/or density) for improved mammography.
[0022] More specifically, in accordance with an aspect of the present invention, there is provided a system for generating microfocused laser-based x-rays comprising an ultra-fast laser; and a solid target with elemental composition positioned in the focal plane of said ultra-fast laser; wherein said ultra-fast laser and solid target are configured so that interaction with said solid target of a laser beam produced by said ultra-fast laser produces suprathermal electrons that penetrate said solid target in a spot whose size is comparable to the ultra-fast laser focal spot size, yielding hard x-rays More specifically, in accordance with another aspect of the present invention, there is provided
[0023] A method for generating microfocused laser-based x-rays using the above system, the method comprising: without The solid target, generating and amplifying from the ultra-fast laser, a first laser beam pulse train so as to control and adjust the laser energy, positioning the target in the focal plane of the ultra-fast laser so as to offer a fresh surface to the ultra-fast laser; generating and amplifying from the ultra-fast laser, a second laser beam pulse train, and releasing and focusing the second laser beam pulse train on the solid target; whereby the interaction of the second laser beam pulse train on the target generates hard x-rays.
[0024] A system and method according to the present Invention allows producing a very small x-ray source with an x-ray spectrum tailored to a specific patient's breast density and thickness suitable to detect pathology in examined breast, for example microcalcifications, with increased sensitivity and specificity, as compared to method and system from the prior-art.
[0025] Compared to systems and methods from the prior art, a system and method according to the present invention allows to lower calcification detection threshold size down to approximately 30 μm, improves visualization of morphology of microcalcifications and marginal characteristics of masses, improves detection of densities (masses), especially in a dense breast tissue, lowers mean grandular dose, especially in a dense and thick breast tissue, and enhances both sensitivity and specificity of mammography.
[0026] A method and system according to the present invention yields very small (below 30 μm) x-ray focal spot size that will results in:
[0027] significantly improved and uniform within field of view spatial resolution of the order of 20 lp/mm. In conventional mammography resolution is non-uniform and do not exceed 13 lp/mm. The upper quadrants of thicker (d>6 cm) breasts are imaged with resolution below 10 lp/mm and there is strong gradient of spatial resolution across field of view (in the cathode-anode direction) in the detector plane,
[0028] better visualization of pathologies, including demonstration of morphology of very small microcalcifications that cannot be imaged with conventional mammography, that will allow earlier detection of breast cancer with significant benefit for women's health; and
[0029] magnification imaging without necessity of moving breast closer to the source This is necessary in conventional mammography and results in decreased field of view
[0030] Moreover a method and system according to the present invention allows x-ray spectrum to be tailored to specific breast thickness/density that will result in:
[0031] lower dose to thicker/denser breast with better contrast, as compared to conventional mammography. Dose saving can be as large as factor of three for very thick/dense breast (d>>4.5 cm); and
[0032] better imaging of thicker/denser breast due to shorter imaging time. It might completely eliminate “white mammograms” presently obtained with radiopaque breast.
[0033] Other objects, advantages and features of the present invention will become more apparent upon reading of the following non-restrictive description of preferred embodiments thereof, given by way of example only with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0034] In the appended drawings:
[0035] [0035]FIG. 1 is a schematic view illustrating an x-ray mammography system including a system for generating microfocused laser-based x-rays according to an embodiment of the present invention;
[0036] [0036]FIG. 2 is a graph illustrating The optimum x-ray energy for imaging various pathologies according to the breast thickness:
[0037] [0037]FIG. 3 is a graph illustrating the energy conversion efficiency from hot electrons into characteristic line emission,
[0038] [0038]FIG. 4 is a graph illustrating the optimum laser intensity as a function of the target material atomic number Z,
[0039] [0039]FIG. 5 is a schematic view illustrating the laser-solid interaction as provided by the x-ray mammography system from FIG. 1 using a flat target, and
[0040] [0040]FIG. 6 is a schematic view illustrating the laser-solid interaction as provided by the x-ray mammography system from FIG. 1 using a shaped target
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0041] Turning to FIG. 1, an x-ray mammography system 10 incorporating a system for generating microfocused laser-based x-rays 12 according to embodiments of the present invention are illustrated.
[0042] The x-ray generator 12 is based on both a stationary ultra-fast CPA (chirped-pulse amplified) laser 14 and a solid target 16 with elemental composition so positioned as to be in the focal plane of The laser 14 .
[0043] As it will be explained hereinbelow in more detail, the ultra-fast laser 14 and solid target 16 are chosen and configured so that interaction of a laser beam produced by the ultra-fast laser 14 with the solid target 16 produces suprathermal electrons that penetrates the solid target 16 in a spot whose size is comparable to the ultra-fast laser 14 focal spot size. This allows simultaneously optimizing the source size, the x-ray yield and the photon energy
[0044] The target 16 is mounted in a movable target chamber 18 provided with rapid target/filter changer (not shown), a precision target positioning system 20 , a target position monitor and feedback system 21 , a target ablation products removal system (not shown), and a vacuum pump 22 for providing vacuum condition in the chamber and more specifically on the target surface. The target chamber 18 allows to precisely positioning a selected area of the target 16 relatively to an x-ray window 24 . The x-ray window is located so as to allow hard x-rays produced by the laser-target interaction out of the target chamber in the direction an image receptor 40 as it will be explained hereinbelow in more detail. The movable target chamber allows obtaining all views required in mammography including cranio-caudal view (CC), the medio lateral oblique view (MLO), the latero media) (LM), the medio lateral (ML) and supplemental views
[0045] The target/filter allows to properly shape the x-ray spectrum A precision target positioning/feedback allows to keep the x-ray focal spot small.
[0046] The precision target positioning system 20 allows mounting and moving, including translation and rotation, the target 16 for reason explained hereinbelow. The target position monitor and feedback system 21 helps precisely position the target relative to the laser focal point and x-ray window 24 As will be explained hereinbelow, the target is to be moved between laser shots so as to expose for each new shot a fresh surface thereof. Since precision positioning systems, and target position monitor and feedback systems are believed to be well known in the art, and for concision purposes, they will not be described herein in more detail
[0047] The x-ray window 24 is preferably made of beryllium. Of course other type of x-ray window may alternatively be used such as Kevlar thin foil
[0048] Of course, the target chamber 18 includes other structures, mechanisms and electronics required for the operation and interactions of the above-mentioned component as it is commonly known in the art. Other features of the movable vacuum target chamber 18 will become more apparent upon reading the following description.
[0049] The x-ray generator 12 also comprises an optical beam transfer system 26 , coupling the stationary ultra-fast CPA laser 14 and the movable target chamber 18 .
[0050] The optical beam transfer system 26 includes adjustable mirrors 28 and an optical beam-focusing device 30 . The optical beam-focusing device 30 advantageously includes optical feed back system (not shown) for stable laser beam aiming at the target 16 , and an adjustable parabolic mirror 32 . The vacuum target chamber 18 includes an optical window 34 allowing a laser beam focused by the parabolic mirror 32 to enter the chamber 18 and hit the target 16 . The optical window 34 is chosen so as to be transparent to the wavelength of the laser 14 and is advantageously made of MgF. Other suitable transmitting material can also be used. The flat and parabolic mirrors 28 , 34 are obviously provided with appropriate mounts (not shown)
[0051] Of course, the optical beam transfer system 26 may alternatively have other configurations than the one depicted on FIG. 1 For example, the CPA laser 14 may be positioned so that its beam directly aims at the target 16 , with the target positioned at the focal point of the laser 14 .
[0052] The target chamber 18 further includes a set of filters 36 that are mounted to the x-ray window 24 , and an x-ray collimator 37 . They allow to properly shape the x-ray spectrum and the x-ray field of view to maximize the image contrast within constrains imposed by the maximum allowable glandular radiation dose and the maximum exposure time.
[0053] The x-ray mammography system 10 further includes conventional compression paddles 38 for breast, an image receptor 40 optionally provided with removable mammographic grid 42 allowing for contact magnification imaging, and an automatic exposure and target selection control 44 . The automatic exposure control is well known in conventional mammography and is used to avoid over- or under-exposure of the imaged breast. The automatic target selection allows perfect match of the x-ray spectrum and a specific patient's breast thickness/density, resulting in the best contrast at the lowest dose Conventional mammographic x-ray units typically use Mo target Some units have an additional Rh target but the maximum load (mAs) for Rh is significantly constrained, as compared to Mo, and Rh is used infrequently. The image receptor 40 is a mammographic film/screen combination or a mammographic digital detector
[0054] The compression paddles 38 are located between the image receptor 40 and the target chamber 18 , and are movable (represented by double-arrow 46 on FIG. 1) so as to advantageously yield an adjustable air-gap between the paddles and the image receptor 40 . Very small x-ray focal spot size allows the possibility to perform mammography in a full field of view magnification mode with the air-gap acting as anti-scatter device and without necessity to move imaged breast closer to the x-ray source Thus, it is possible to simply move away the image receptor from the breast while keeping breast at the same distance from the x-ray source as in the contact mammography (e.g. 65 cm), and obtain good quality magnified images. In conventional mammography only spot magnification (i.e. with very small field of view) images might be obtained and the imaged breast has to be positioned much closer to the source (e.g. at 40 cm), as compared to contact technique (e.g. 65 cm).
[0055] The image receptor 40 may take many forms such as a mammographic film/screen combination or a digital detector. Since digital detectors and mammographic film/screen combination are believed to be well known in the art, and for concision purposes, they will not be explained herein in more detail
[0056] Of course, the x-ray mammography system 10 also includes other well-known non-illustrated components such as optical and x-ray shielding for operator and patient protection, and a system diagnostics
[0057] The operation of the x-ray generator 12 will now be described in more detail.
[0058] Without target 16 , a first sequence of high voltages is triggered for the generation and amplification of a first laser beam pulse train in order to control and adjust the laser energy
[0059] The target 16 is then positioned in the focal plane of the optical beam.
[0060] It is to be noted that the motion of the target (rotation and or translation in a fixed plane) is triggered in order to offer a fresh surface at every laser shot.
[0061] A second sequence of high voltages is then triggered for the generation and amplification of the interacting laser beam pulse train with appropriate energy and pulse number. The pulse number is selected using an adjustable gate
[0062] The pulse is compressed in an optical compressor composed of a set of gratings and mirrors. The shutter is opened at the compressor exit to release the pulse train on the target 16 . The laser pulse 50 (see FIG. 5) is of course focused onto the target 16 by means of the parabola 32 .
[0063] Hard x-rays 54 are produced during the interaction laser beam-target interaction.
[0064] Turning now to FIG. 5, the laser-target interaction is schematically illustrated.
[0065] [0065]FIG. 5 illustrates the laser-solid interaction for the flat target case. In this example, the focal spot size is about 3 μm in diameter and the incidence angle of the laser beam 50 hitting the surface 16 is 45°. The hatched area represents the 2D slab 52 of thermal plasma generated via radiation pressure confinement.
[0066] The angle of incidence of the laser pulse 50 on the target 16 , the laser polarization and the target 16 are so chosen as to match the density gradient scale length set by the radiation pressure confinement. Under these conditions, the resonance absorption mechanism that is at the origin of the hot electrons 48 , and thus the energy transfer from the laser 14 to the hot electron population 48 is optimized As the resulting plasma is a thin two-dimensional slab (as illustrated in FIG. 5) or three-dimensional droplet (not illustrated) (gradient scale length smaller than the laser beam focal spot size), the trajectories of the hot electrons 48 are limited to the laser focal spot, which can be as small as a few micrometers The electrons 48 penetrate the target in a spot whose size is comparable to the laser spot size. The generated hot electron distribution f(e), is Maximilian More specifically:
f ( e )= AE 1/2 exp (− E/kT H ,
[0067] where T H is the hot electron temperature and k is Planck constant.
[0068] A judicious choice of target geometry and composition, of the laser pulse duration, polarization and/or intensity, allows shaping the x-ray spectrum and to maintain and control the hot electron temperature between 10 and 50 keV. The conversion efficiency is drastically reduced for hot electron temperatures lower than 10 keV It has also been found that hot electron temperatures higher than 50 keV induce a degradation of imaging contrast due to the high-energy tail in the x-ray spectrum The emitted x-ray spectrum is composed of continuum bremsstrahlung and discrete emission lines. The K α lines radiation is dominant over bremsstrahlung and can be used, with appropriate filtering for imaging
[0069] As it will be explained hereinbelow in more detail, the laser 14 is configured for providing sufficiently high-contrast sub-picosecond pulses with peak and average power optimized for the imaging task, i.e. breast thickness, composition and imaging time.
[0070] According to the present invention, the radiation pressure of the pulse produced by the laser 14 is used to balance the thermal plasma pressure occurring on the target 16 during the laser pulse. This allows the thermal and hydrodynamic mechanisms tending to spread the plasma to be overcome and thus the plasma size (perpendicularly to the target surface) to remain very small. The trajectories of hot electrons 48 above the target 16 surface are then limited and controlled, thus minimizing the x-ray source size
[0071] The laser parameters are controlled as follows. A very high contrast laser pulse (10 10 ·1), indicative of the intensity peak/background noise ratio, is required to help prevent significant plasma expansion before the arrival of the main pulse The pulse duration is set larger than 300 fs and the laser intensity is selected so as to be in the range 10 18 W/cm 2 -10 19 W/cm 2 . At lower intensity the thermal pressure is dominant and the plasma freely expands during the laser pulse, while at higher intensities the radiation pressure can be so high that plasma profile modification becomes a problem In the optimum intensity range, a still two-dimensional plasma slab 52 having characteristic dimensions of optical laser diameter (typically 3 μm) by thermal penetration depth (typically 0.3 μm) is produced during the laser pulse, resulting in constrained hot electron 48 trajectories above the target surface 55
[0072] The control of the x-ray source size imposes utilization of a well-defined narrow intensity range (10 18 W/cm 2 -10 19 W/cm 2 ). It has been found that this intensity range is also the most appropriate one for the x-ray photon energy adjustment to optimize imaging for a given breast thickness/density It has also been found that the energy conversion efficiency (η k ) from hot electrons into characteristic line emission reaches maximum when the hot electron temperature (kT n ) is about 3 times the photon energy (E k ) of the characteristic line emission (see FIG. 2) Therefore, the photon energy E k is adapted to a specific breast thickness, by adjusting the hot electron temperature so as to yield kT n /E k =3.
[0073] The hot electron temperature can be adjusted by a careful laser intensity control indeed, it has been found through experiments that
kT n =α( lλ 2 ) 1/3 ,
[0074] where l is the laser intensity and λ is the laser wavelength. Radiation Confined Plasmas yields α=5×10 −5 when kT n is in keV, l in W/cm2 and λ in μm as deduced from experiments with a 400 fs laser pulse at 0.53 μm wavelength. This yields the following expression for the optimum intensity (corresponding to kT n /E k =3)
l opt =bE K 3 /λ 2
[0075] This optimum intensity as a function of the target material atomic number Z is shown in FIG. 4 for a 400 fs laser pulse at 0 53 μm wavelength (l opt (W/cm 2 )=7.7×10 14 E K 3 (with E K in keV)). Consequently, energy and yield-optimized x-ray spectra for particular breast thickness and density can be generated by careful selection of both target material and laser intensity.
[0076] The laser intensity window, for example, for a laser having a 400 fs pulse and 0 53 μm wavelength, is in the 2×10 18 W/cm 2 -10 19 W/cm 2 range for production of x-ray spectra suitable for optimized imaging of breast thickness between 2 cm and 8 cm with target atomic number Z between 38 and 50. The use of this intensity range simultaneously allows
[0077] using RCP and thus controlling the hard x-ray source size;
[0078] utilizing targets with the appropriate elemental composition to match the x-ray energy to a patient specific breast thickness/density with an optimized conversion efficiency (η K ).
[0079] It has been found that a pulse duration between 200 fs and 600 fs allows to optimize the plasma confinement effect Through radiation pressure and thus to optimize the x-ray source parameters. Through experiments and calculations, it has also been found that shorter (150 fs) and longer (1 ps) pulse resulted in lower conversion efficiency and/or larger x-ray spot size. According to a preferred embodiment of the present invention, a typical value used for the pulse duration is 400 fs (with no pre-pulse and/or pedestal)
[0080] A theoretical investigation of the optimum monochromatic x-ray energy for imaging various simulated pathologies in the breast for a large range of breast thickness spanning the 2-cm-8-cm range was performed. The following figure of merit (FOM) was evaluated
FOM =(contrast) 2 /dose
[0081] Simulated pathologies included 200-μm calcifications and 5-mm masses.
[0082] It has been confirmed that the shape and the exact location of maximum depend on the imaging object. However in each case the optimum energy shifts towards higher energy for thicker/denser breast for all the investigated pathologies. It has been found that the optimum photon energy increases from ˜15-18 keV for 2 cm Lucite equivalent breast to ˜25-28 keV for 8 cm Lucite equivalent breast. FIG. 2 shows the calculated optimum photon energy corresponding to FOM maximum as a function of the Lucite equivalent breast thickness
[0083] For larger breast thickness/density (d>4.5 cm) imaged with ultra-fast-based laser x-ray source, we expect significant improvement in the dose utilization without loss of contrast, as compared to imaging with a mammographic x-ray tube operating at increased kilovoltage (28-31 kVp)
[0084] The target 16 can be made in many forms including a continuous thin tape with a plastic substrate, rotating cylindrical or planar solid targets. In any case, the target is rapidly moved between each laser shot so that a fresh surface, with possibly different elemental composition (when required), is exposed to every shot. Possible target elemental compositions include Mo, Rh, Ag, In, Sn, with the K α lines in the 17 4-27.4 keV range. Via selection of a suitable laser target elemental composition and matching filter 36 material, x-ray spectrum from the LPP x-ray source can be tailored to a specific breast thickness and composition, as well as to a detector used.
[0085] Preferably, an x-ray generator 12 according to the present invention includes a shaped target 16 ′ as illustrated in FIG. 6.
[0086] In both cases, hot electron 48 trajectories (illustrated in both FIGS. 5 and 6 by full-arrows returning from the slab 52 to into the target 16 ) are constrained but with flat targets 16 only a fraction of the produced hot electrons 48 is coming back inside the target into a very small spot, producing hard x-rays 54
[0087] As illustrated in FIG. 6, shaped targets produced for example by machine indentation, allows increasing the coupling of hot electrons 48 ′ to the target 16 ′ without increasing The source size. It has been found that the x-ray yield increases when the laser beam 50 interacts with preformed craters 56 (with characteristic dimensions: optical laser diameter (3 μm) by a laser ablation depth (1 μm)). The walls 58 of the indentation are capturing electrons that normally escape with a flat target 16 However the shaped target 16 ′ adds a level of complexity since the target 16 ′ positioning has to be controlled with a very high precision level using the precision target positioning system 20 .
[0088] The operation of the overall x-ray mammography system 10 will not be described herein in more detail since it is believed to be well known in the art
[0089] Although the present invention has been described hereinabove by way of preferred embodiments thereof, it can be modified, without departing from the spirit and nature of the subject invention as defined in the appended claims. | The present invention concerns x-ray sources for mammography. A microfocused x-ray source of small size (30 μμm and smaller) with x-ray spectrum optimized for enhanced mammography is obtained with a method and system according to the invention. The proposed x-ray source is based on the use of plasmas created by the energy distribution of suprathermal electrons that are produced during the interaction of the laser beam with a solid target. These hot electrons penetrate the surface layer of cold plasma and interact with the solid core of the target. The method and system according to the present invention allows optimizing the x-ray source size, its spectral distribution, and the conversion efficiency in the 17.3-28 5 keV range (adapted to the breast thickness). | 7 |
TECHNICAL FIELD
[0001] The present invention relates to an electric blower for use in an air conditioner or the like coupled to a duct to supply an airflow necessary to a refrigerating cycle or the like in response to the duct condition.
BACKGROUND ART
[0002] There has been the kind of conventional electric blower that, observing always a fan rotation speed and the PWM (Pulse Width Modulation) signal for an electric motor to calculate the amount of airflow to compare the calculated amount of airflow with an amount of target airflow, corrects the control signal sent to the electric motor if there is a difference between the two, which is so-called a feedback control method. The technology is disclosed for instance in Japanese Patent Unexamined Publication No. H07-301450 (hereafter referred to as patent document 1).
[0003] FIG. 3 shows a process flowchart of a conventional electric blower described in patent-document 1 . As shown in FIG. 3 , the control process of the conventional electric blower comprises; step 135 to recognize the amount of target airflow; step 140 to calculate the amount of airflow by using the PWM signal sent to the electric motor at present and the fan rotational speed; steps 145 and 150 to compare the calculated amount of airflow with the amount of target airflow; steps 155 and 165 to correct the PWM signal according to the comparison results; and step 160 to send the corrected PWM signal to the motor controller, repeating from step 135 to step 160 constantly.
[0004] However, owing to pulsations occurring inevitably in the airflow of electric blowers, conventional electric blowers cannot continue to operate stably matching the amount of target airflow with the calculated amount of airflow, but is operated always fluctuated in the rotation speed. Moreover, elements having big inertia such as the electric motor and fan included in the feedback control system could cause overshooting or depending on conditions the pulsation could be amplified to cause an unstable rotation speed fluctuating largely
SUMMARY OF THE INVENTION
[0005] The present invention aims at providing an electric blower to solve the above-mentioned drawbacks, which can operate stably keeping an amount of target airflow in response to conditions of duct.
[0006] To solve the above-mentioned drawbacks the electric blower of the present invention includes an electric motor, a blower with a fan driven to rotate by the electric motor, and a controller to control the electric motor. The controller comprises: a load-detector to detect output data on the magnitude of the load; a rotation-speed-calculator to calculate output data on the fan rotation speed required for the blower to discharge the amount of target airflow according to the magnitude of the load of the fan output from the load-detector and the given amount of target airflow; a rotation-speed-selector to switch over the rotation speed from the load-detection-rotation-speed determined previously to the rotation speed required for the blower to discharge the amount of target airflow according to the data output from the rotation speed calculator; and a timing-device to determine the operation timing for the load-detector, rotation-speed-calculator and rotation-speed-selector respectively.
[0007] The configuration can perform a stable operation for the controlled airflow without amplifying the pulsation in the rotation speed, because the timing device is allowed to work according to need such as before the operation starts or when a load condition varies to detect the duct condition beforehand and can operate the blower at a rotation speed capable of discharging the amount of target airflow in response to the duct condition detected.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 illustrates a block diagram of the electric blower used in exemplary embodiment 1 of the present invention.
[0009] FIG. 2 illustrates a characteristic showing a relation between the amount of airflow and rotation speed of the electric blower used in exemplary embodiment 1 of the present invention.
[0010] FIG. 3 illustrates a flowchart of a conventional electric blower.
DETAILED DESCRIPTION OF THE INVENTION
Exemplary Embodiment 1
[0011] Generally, an amount of airflow is proportional to a rotation speed of a fan included in a duct when the duct condition is determined and the duct condition affects relative gradients or the like. If, therefore, the duct condition is detected somehow the relation between the amount of airflow and rotation speed can be determined. The duct condition is detectable as a load of the blower and the load of the blower is detectable as an output force of an electric motor as well. Moreover, because the output force of the electric motor is proportional to the product of the rotation speed and torque of the fan, the duct condition can be detected from the torque of the electric motor when the rotation speed is kept constant. In case of a DC motor, whose torque is proportional to the input current, the torque can be detected by measuring the motor input current. Therefore, the duct conditions can be detected by measuring the motor input current.
[0012] The present invention is to detect the duct condition according to a value showing the magnitude of the load of the blower (hereafter referred to as a blower-load-variable) obtained from the input current of the electric motor operating at a predetermined rotation speed. To measure the blower-load-variable, the blower must operate at a predetermined rotation speed.
[0013] Namely, through the operation to detect the load by measuring the input current of the electric motor operating at a predetermined rotation speed, the duct condition is detected as a blower-load-variable. A fan rotation speed to discharge the amount of target airflow in response to the duct condition is calculated according to an empirical formula having been obtained from the characteristics of the blower. Subsequently, controlling the motor to rotate the fan at the given rotation speed can realize an operation for a stable airflow without doing any constant feedback control.
[0014] Now, exemplary embodiment of the present invention is described with reference to the drawings. The present invention is not limited to the exemplary embodiment only.
[0015] FIG. 1 is a block diagram of the electric blower used in exemplary embodiment 1 of the present invention. In FIG. 1 , electric blower 1 of the present invention includes electric motor 25 , blower 20 and controller 10 .
[0016] Electric motor 25 supplies a driving force necessary to rotate blower 20 . A DC brush-less motor is employed in the exemplary embodiment. The driving shaft of electric motor 25 is coupled to blower 20 directly.
[0017] Blower 20 flows air through duct system 15 forming an air-path. A sirocco fan is used in the blower of the exemplary embodiment.
[0018] Controller 10 includes variable-motor-controller 30 , airflow-controller 35 and system-controller 40 .
[0019] Variable-motor-controller 30 controls the rotation speed of the electric motor, in response to control-signal Fo produced in airflow-controller 35 . Additionally, variable-motor-controller 30 detects the motor rotation speed, and sends it to airflow-controller 35 as motor-rotation-speed-signal Rm.
[0020] Airflow-controller 35 includes timing-device 100 , load-detector 105 , rotation-speed-calculator 110 , rotation-speed-selector 120 and control signal feeder 90 .
[0021] Timing-device 100 allows to start load-detector 105 at a prescribed timing.
[0022] Load-detector 105 , receiving signals from timing-device 100 , outputs load-detection-rotation-signal Fra to drive electric motor 25 at a load detection rotation speed. Load-detector 105 , additionally, outputs blower-load-variable Tra according to the electric motor input current Im measured at this time.
[0023] System-controller 40 , varying the operation capacity of a variable compressor (not shown) in response to an air-conditioning capacity required, sends rotation-speed-calculator 110 information on an amount of airflow, as target airflow Q, corresponding to the varied compressor capacity.
[0024] Rotation-speed-calculator 110 calculates the fan rotation speed for the fan to discharge the amount of target airflow Q by substituting blower-load-variable Tra output from load-detector 105 and the amount of target airflow Q sent from system controller 40 into formula (a) described later. The fan-rotation-speed is then output as fan-rotation-speed-signal Fr.
[0025] Rotation-speed-selector 120 switches over rotation-speed-signal Fs input into control signal feeder 90 from load-detection-rotation-signal Fra to fan-rotation-speed-signal Fr according to fan-rotation-speed-signal Fr output from rotation-speed-calculator 110 .
[0026] Control-signal-feeder 90 sends rotation-speed-control-signal Fo to variable-motor-controller 30 so that rotation-speed-signal Fs from rotation-speed-selector 120 matches with motor-rotation-speed-signal Rm from variable-motor-controller 30 .
[0027] Formula (a) is determined according to the following procedure.
[0028] (1) The blower load condition is detected to determine the blower-load-variable by measuring the input current of the electric motor driving the blower at a predetermined rotation speed.
[0029] (2) The fan rotation speed is varied leaving the blower-load-variable kept constant, and then the amount of airflow of the blower is measured in each varied fan rotation speed.
[0030] (3) The empirical formula is determined as formula (a) from the relationship between the amount of airflow of the blower and the fan rotation speed in the above experiment by using the least-square method.
[0031] An input current value of the electric motor can be directly used as the blower-load-variable, or other value determined unambiguously from the input current value of the electric motor such as the ratio of the electric motor input current to the rated current may also be used as the variable.
[0032] Duct system 15 is a conduit tube used to deliver airflow for certain regions to be conditioned. Duct system 15 is for instance installed in a building to supply conditioned airflow to rooms requiring the air. The static air pressure in duct system 15 is affected by form and length of the duct, damper 45 , filter 50 and heat exchanger 55 .
[0033] Now, the work and function of electric blower 1 with aforementioned configuration is described.
[0034] A command from timing device 100 starts electric motor 25 at a predetermined rotation speed, which rotates blower 20 . When blower 20 reaches a stable rotation speed, rotation-speed-calculator 110 measures blower-load-variable Tra output from load-detector 105 . Blower-load-variable Tra thus measured is what reflects the duct conditions determined by the static air pressure in duct system 15 , the form and length of the duct, filter 50 and heat exchanger 55 .
[0035] FIG. 2 illustrates characteristic curves showing relations between the amount of airflow and rotation speed of the blower from the aforementioned formula (a). The amount of airflow of the blower is proportional to the fan rotation speed, and the values of blower-load-variable Tra (Tra 1 to Tra 4 ) affect the gradient of lines as shown in FIG. 2 .
[0036] For example, the rotation speed Fr is given by the following formula (a), using blower-load-variable Tra and amount of target airflow Q at a load detection rotation speed of 600 r/min.
Fr=− 642.75+6.0837 Tra+ 19598.1/ Tra+ (−121.96+1.819 Tra+ 4134.1/ Tra ) Q
Where
Fr: rotation speed in r/min Tra: blower-load-variable Q: amount of airflow
[0040] With stored data of measured blower-load-variable Tra, rotation speed Fr for the amount of target airflow Q can be calculated by substituting the amount of target airflow signal Q sent from system controller 40 into the above formula (a). The amount of target airflow is supplied to the duct when control signal Fo corresponding to the rotation speed is sent to variable motor controller 30 .
[0041] The aforementioned configuration can adjust the airflow to an amount of target airflow in response to the coupled duct conditions stably, because blower 20 operates at a rotation speed corresponding to the amount of target airflow required for a duct condition detected previously.
[0042] Load-detector 105 , rotation-speed-calculator 110 and rotation-speed-selector 120 could start sequentially, and any case such as sequential starting following output from the precedent elements or sequential starting by control means such as timing device or the like could perform the aim of the present invention.
[0043] Timing-device 100 may be a type that starts together with electric blower 1 . In a newly installed air-conditioner, the type of timing device 100 can detect duct conditions automatically at the start of electric blower 1 instead of having to detect the duct conditions separately. For example, when an operation switch is turned on to operate a compressor (not shown), the load detection operation starts automatically to detect the duct condition by measuring blower-load-variable Tra previously.
[0044] Moreover, timing device 100 may be a type that detects the duct condition regularly. For example, by starting a load detection operation at 12 o'clock every day to measure blower-load-variable Tra and to store the data until 12 o'clock next day, the blower can respond to a change of duct conditions in the case of increase in resistance to the airflow owing to a pile of dust on filter 50 in duct system 15 .
[0045] Additionally, timing device 100 may be a type that operates at the change of airflow condition in duct system 15 , and then starts operation of load detector 105 . The configuration can detect open/shut condition of dampers installed in branches coupled to the duct.
[0046] As described above, the electric blower of the present invention can discharge an amount of target airflow in response to the duct condition and is useful for duct type air conditioners or the like accordingly. | The present invention provides an electric blower that performs: measuring an amount of airflow against a fan rotation speed of the blower with a load magnitude detected previously; determining an empirical formula to calculate a fan rotation speed to discharge an amount of target airflow in response to the magnitude of a load of the blower according to the data obtained from the above measurement repeated a plurality of times varying the magnitude of the load on the blower; operating, firstly in practice, the blower to detect the magnitude of the load of the blower, then to calculate the fan rotation speed to discharge the amount of target airflow using the empirical formula; and then changing the blower operation to the fan rotation speed given by the calculation. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Patent Application No. 62/329,862 filed Apr. 29, 2016, the entire contents and disclosure of which are hereby incorporated by this reference.
TECHNICAL FIELD
[0002] Embodiments described in this application relate generally to lighting products, their mechanical features for attachment, and associated means and methods, and more specifically, retrofitting fluorescent tubular style fixtures as well as integrating the disclosed device(s) into new fixtures with a light-emitting diode (“LED”) light bar, in particular linear tubes.
BACKGROUND
[0003] Current light bar technologies for retrofit applications cause businesses to maintain inventory for a multitude of lighting configurations. Cost incurred range from maintaining inventory of similar light bars, sans the mechanical end style for mounting in existing fixtures, can be costly and difficult.
[0004] When upgrading fluorescent tubular lamps to LED tubes or fixtures, there are many electrical utility rebates that offer a wide range of financial benefits to help reduce energy consumption. Many of these rebates have requirements stipulating how the replacement lighting is installed. Depending upon the utility and/or the rebate the requirements of the retrofit vary. For instance, some rebates mandate that the retrofitting lamp cannot utilize the existing receptacle, (i.e., tombstone).
[0005] This wide range of installation requirements (e.g., fluorescent light tombstone socket options) and selection of different lighting options makes it cumbersome for electrical supply houses, distribution centers, installers, etc., to have all the needed items readily available.
[0006] In applications where new lighting is being installed and no longer require the tombstone sockets, a mounting clip can be used instead.
[0007] Overall, it would be advantageous to have a means for variations in mounting option applications such that a single light bar can qualify for different financial rebates in retrofits or reduce inventory while allowing variations in product offerings.
BRIEF SUMMARY
[0008] The disclosed embodiments and device(s) overcome these above-described requirements by offering a single light bar that can easily transform to fit the requirements of both the rebates and function of retrofitting/installing a fixture or light source.
[0009] Having the ability to utilize the same fixture for a multitude of needs provides a larger variety of rebate and use offerings. For instance, a vapor tight fixture, utilizing the clips and/or rotatable end cap base adaptors can distribute the light in various patters based upon the angle of the mounting application. The variation in angle can allow the same fixture to be used in multiple applications.
[0010] Embodiments of the disclosure generally relate to retrofitting LED light bars into fluorescent tubular style lamp fixtures as well as integrating LED light bars into new lamp fixtures. A single light bar can be utilized with multiple style base ends that allows it to retrofit into a variety of existing fixtures. This results in a method for offering multiple mounting options on an LED light bar for an existing lamp fixture so that electrical utilities' rebate requirements can be met with a single LED light bar assembly.
[0011] A major advantage of the disclosed device(s) is offering a single LED light bar source that has the capability of utilizing any existing fixture receptacle and/or can be mounted independent of the receptacle. Electrical Utilities offer rebates for adoption of LED lighting to reduce energy consumption. These rebates have a myriad of technical requirements regarding how the existing lamp receptacle is utilized when the LED light bar replaces a fluorescent light. In some instances, the fluorescent lamps' tombstone receivers must stay in place but in some instances the tombstones can be removed. Removal of the tombstones in a lighting retrofit is sometimes regarded as less labor intensive since the fluorescent ballast, its high voltage wiring, and tombstones can all be removed as a single assembly. These components are then replaced by LED light bars, the LED power supply and dedicated direct current (DC) wiring. When the tombstones must remain in place, the high voltage wiring is cut and the fluorescent lamp ballast is removed. The interchangeability of the end base adaptors allow for either adaptation and installation to the existing fixture. Moreover, if the rebate requirements state that the tombstones must remain in place but the end base adaptors cannot be used, this invention will allow the light bar to fit in between the existing fixture receptacles with the interchangeable base adaptors removed. This ability of the invention helps reduce the additional labor and inventory needed by businesses to meet the rebate requirements in different localities.
[0012] Accordingly, various embodiments of the disclosure and disclosed device(s) have a base cap on both sides. This base cap has a receiving adaptor end base that can either not have any adaptor and be used as a traditional light bar with separate mounting clips or can use an interchangeable base adapter. The interchangeable base offers several adaptors that will fit in the existing light fixtures receptacle. Standard receptacles in the field are G13 for 4-foot tubes and Fa8 for 8-foot tubes. Other standard receptacle options can easily be created to this interchangeable adapter base system.
[0013] Embodiments of the disclosure and device(s) also generally relate to offering the interchangeable base to any size length of light bar. This will allow for the reduction of inventory but create a large array of offerings. Further, they provide the ability to offer an interchangeable and removable end base adaptor which greatly increases the number of stock keeping units (SKU) that can be offered while reducing the quantity of lamps needed to be in stock. These novelties pass the same benefits of additional flexibility in product offerings to distributors. Other advantages, benefits and applications may exist.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Advantages of the various embodiments described in this disclosure will be apparent to those of ordinary skill in the art from the following detailed description and the appended drawings:
[0015] FIG. 1 shows a broken view of an embodiment of the lamp assembly;
[0016] FIG. 2 shows an exploded view of an embodiment of the lamp assembly and various convertible base adapters;
[0017] FIG. 3 shows a side view A-A of an embodiment of adapter base 16 ;
[0018] FIG. 4 shows a perspective broken view of t an embodiment of the lamp assembly along with depicting cutting planes for sections B-B and C-C;
[0019] FIG. 5 shows Section B-B from FIG. 4 ;
[0020] FIG. 6 shows Section C-C from FIG. 4 ;
[0021] FIG. 7 shows an exploded top view of embodiments of the end base and metal extrusion;
[0022] FIG. 8 shows an exploded side view of embodiments the end base and metal extrusion;
[0023] FIG. 9 shows a perspective view of the end base and metal extrusion assembled according to an embodiment of the disclosure;
[0024] FIG. 10 shows the end view of two light bars assembled with an angular mounting clip according to an embodiment of the disclosure;
[0025] FIG. 11 shows a front view of a rotating head of an embodiment of a rotating base adapter;
[0026] FIG. 12 shows a side view of an embodiment of a rotating base adapter;
[0027] FIG. 13 shows an embodiment of the locking feature of the rotating base adapter;
[0028] FIGS. 14 and 15 show an existing light fixture being retrofitted with the LED light bars disclosed herein;
[0029] FIG. 16 shows a front view of a light fixture including an embodiment of an angled clip;
[0030] FIG. 17 shows a right side view of an embodiment of an angled clip;
[0031] FIG. 18 shows a perspective view an embodiment of an angled clip;
[0032] FIG. 19 shows a front view of a light fixture having an embodiment of a vertical clip;
[0033] FIG. 20 shows a right side view of an embodiment of a vertical clip;
[0034] FIG. 21 shows a perspective view of an embodiment of a vertical clip;
[0035] FIGS. 22A and 22B show the insertion of an angled clip into a fixture according to an embodiment of the disclosure; and
[0036] FIG. 23 shows a new light fixture fitted with embodiments of angled and vertical clips supporting light bars.
DETAILED DESCRIPTION
[0037] In the following detailed description, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration specific embodiments in which the disclosure may be practiced. These embodiments are described in sufficient detail to enable those of ordinary skill in the art to practice the disclosure. It should be understood, however, that the detailed description and the specific examples, while indicating examples of embodiments of the disclosure, are given by way of illustration only and not by way of limitation. From this disclosure, various substitutions, modifications, additions rearrangements, or combinations thereof within the scope of the disclosure may be made and will become apparent to those of ordinary skill in the art.
[0038] In accordance with common practice the various features illustrated in the drawings may not be drawn to scale. The illustrations presented herein are not meant to be actual views of any particular method, device, or system, but are merely idealized representations that are employed to describe various embodiments of the disclosure. Accordingly, the dimensions of the various features may be arbitrarily expanded or reduced for clarity. In addition, some of the drawings may be simplified for clarity. Thus, the drawings may not depict all of the components of a given apparatus (e.g., device) or method. In addition, like reference numerals may be used to denote like features throughout the specification and figures.
[0039] Information and signals described herein may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof. Some drawings may illustrate signals as a single signal for clarity of presentation and description.
[0040] Disclosed is a multi-use light bar to ease installation and assembly. More particularly, but not by way of limitation, the disclosure relates to a multi-use light bar that includes interchangeable base adaptors that are designed to be fastened to existing lamp receptacles, e.g., G13 (bi-pin), Fa8 (single pin), R17D (protruding end cap). This allows for a single light bar to readily emulate different mechanical mounts. Other embodiments of the end cap adaptors include rotatable bases, connectors linking one light bar to the next and/or other mounting methods to existing receptacles in fixtures or to ease assembly in new fixtures.
[0041] Also disclosed are mounting clips that may be used if the light bar is not utilizing the existing fixture receptacles. The LED light bar is supportable with mounting clips and/or a receptacle that readily attach to a fixture and/or location via, e.g., self-tapping screws or other affixing methods. Such mounting clips snap into the light bar's (or bars') longitudinal grooves to hold it in place either between the existing receptacles or in other such locations. Additionally, for new fixtures the disclosed device(s) can be easily mounted in the grooved clips or receptacle for the light bar. Light bars may be installed at fixtures to change light output, change beam pattern, or change kelvin options, using the existing fixtures. For example, if an existing fixture is adhered to a specific location and light is provided to a specific target (e.g., a refrigerator door light, a closet light, an oven light a car light, etc.), the devices and techniques described herein may be used to install a light bar that distributes light at different intensities, beam patterns, with more efficient power consumption characteristics, etc.
[0042] With reference to FIG. 1 , an LED light bar 1 is shown that is depicted having a breakaway within its length. Light bar 1 consists of end base 2 , 3 , lens 5 , metal extrusion 9 , and circuit card assembly 11 . In some embodiments, metal extrusion 9 can be of materials other than metal such as plastics.
[0043] Depicted on circuit card 11 and along its length are LEDs 12 that are commonly arranged in a linear pattern. Dimension “L” 8 indicates that the overall length, which can be nearly any practical length required for this type of lighting design. A pair of base adapters 14 , 17 are utilized at each end of light bar 1 enabling it to fit standard light fixtures. Lens 5 is typically a translucent plastic usually of a white color, but could be created in other colors or made water clear.
[0044] Now referring to FIG. 2 , is shown more detail of the end of light bar 1 . Particularly are shown connecting adapters 14 , 15 , and 16 . Each of the adapters have their own respective pins 26 , 27 , and 28 , which are both standard sizes to the lighting industry and are all made of electrically nonconductive materials. End pins 26 could be made of metal, but would not be connected to any electrical circuit. Pins 26 , 27 , and 28 are meant to be both an adaptive element in order to adapt to existing electrical hardware while also forming a structural element to hold the light bar 1 in an existing lamp fixture (not shown). Dovetail 21 is a common geometric detail of end adapters 14 , 15 , and 16 and can be received in the direction of arrow 25 by a mating dovetail 20 which is part of base adapter 2 , 3 . The open side of dovetail 20 is always radially located to the same side as lens 5 so as to maintain the securest attachment when light bar 1 is located overhead using base adapters 14 , 15 , 16 . Base adapters 14 , 15 , and 16 are meant to be used as respective pairs when used with light bar 1 . Light bar 1 is also meant to be used independent of base adapters 14 , 15 , 16 in another embodiment.
[0045] Referring now to FIG. 3 , shown is a side view A-A of adapter base 16 . Common geometry to all interchangeable base adapters 14 , 15 , 16 are dovetail 21 locking boss 22 . As any one of base adapters 14 , 15 , 16 are a mated with base end 2 , 3 via dovetail 20 , 21 locking feature 22 received by notch 27 . Locking feature 22 and notch 27 are created such that the adapter base 14 , 15 , 16 can be released again from end base 2 , 3 by finger pressure pushing them apart.
[0046] Referring now to FIGS. 4, 5, and 6 , shown is a perspective view of LED light bar 1 along with its respective SECTION VIEWS B-B and C-C. Mounting of light bar 1 to an existing light fixture (not shown) is accomplished by the use of mounting clip 6 , 8 in two positions along with threaded fasteners 53 , 54 . Now with regards to FIG. 5 , SECTION B-B is showing geometric details of metal extrusion 9 which embodies symmetric and opposite grooves 31 , 32 and 35 , 36 the purpose of which are then shown in FIG. 6 , SECTION C-C. Clip 6 has legs, 40 , 41 , which can flex slightly in direction of arrow 49 . The flexure of legs 40 , 41 allows these to open as they slide over metal extrusion 9 . Legs 40 , 41 are then biased allowing feet 33 , 34 to engage into grooves 31 , 32 and hold light bar, 1 in place. Grooves 31 , 32 run the length of light bar 1 and allow a pair of mounting clips 6 , 8 to be positioned in any practicable position along metal extrusion 9 in the directions of arrow 50 . Flexibility of legs 40 , 41 also allow for the light bar 1 to be detached from clip 6 , 8 without having to remove threaded fasteners 53 , 54 . To ease overhead installation, holes 108 , 109 in clips 6 , 8 , have a geometric star pattern 110 that protrudes within holes 108 , 109 . Pattern 110 allows fasteners 53 , 54 to be started into holes 108 , 109 and held by their threads as a self-holding method.
[0047] Now referring to FIGS. 7, 8, 9 are shown only the metal extrusion 9 and base cap 2 . Base cap 2 , 3 are used to close the entire light bar assembly 1 without adhesives or threaded fasteners. Fastening of end base 2 to extrusion 9 or end base 3 to extrusion 9 is accomplished using snap geometric features. Legs 63 , 64 , 65 are flexible members allowing them some bias ability. Boss features 60 , 66 , 67 communicate and are received in extrusion holes 61 , 68 , and 69 ( 69 not shown, but exactly opposite of hole 68 , FIG. 8 ) when moved together in the direction shown by arrow 70 . Biasing from legs 63 , 64 , 65 keep boss features 60 , 66 , 67 in their respective holes. Completed mate of end base 2 and extrusion 9 is shown in perspective view FIG. 9 . Opposite end of extrusion 9 of light bar 1 is assembled in exactly the same way between extrusion 9 and end base 3 .
[0048] Referring to FIG. 10 , what is shown in FIG. 10 is multi-clip adapter 90 holding a pair of light bars 1 on angles relative to one another and base feature 96 (end base 2 is not shown on the right side of FIG. 10 ). In one embodiment, the multi-clip 90 is adapted to hold a pair of light bars 1 at a 90° angle relative to one another, 45° relative to the Base features 96 .
[0049] Multi-clip 90 adapts light bar 1 in situations where a direction of light beams are required for best implementation of light bar 1 . Multi-clip 90 has legs 92 , 93 which can flex slightly in direction of arrow 98 . The flexure of legs 92 , 93 allows these to open as they slide over metal extrusion 9 . Legs 92 , 93 are then biased allowing feet 94 , 95 to engage into grooves 31 , 32 of extrusion 9 (see FIG. 5 ) and hold light bar, 1 in place. Grooves 31 , 32 run the length of extrusion 9 of light bar 1 and allow a pair of mounting multi-clips 90 to be positioned in any practicable position along metal extrusion 9 in the direction of its length 8 . Multi-clip 90 has a planar mounting surface 97 that can be attached to any other planar mounting surface with threaded fasteners, adhesives, or similar fasteners known in the art. Base features 96 could be of other geometric shapes (i.e., curved) to allow for mounting to surfaces other than planar ones.
[0050] Referring now to FIGS. 11, 12, and 13 is rotational adapter base 80 comprising base adapter 83 and rotating head 88 . Similar to adapter bases 14 , 15 , 16 , adapter base 83 has dovetail 21 for mating with base adapter 2 , 3 and their dovetail 20 . Rotating head 88 has an integral axle 86 that is received by bore 85 in base adapter 83 . Axle 86 and bearing 85 allows a relative rotation of rotating head 83 to base adapter 83 shown by centerline 81 and curved arrow 84 . When a pair of rotational base adapters 80 is mated with LED light bar 1 , the light can be rotated to a position for optimum lighting of an area. A ball detent 82 enables a temporary locking feature between rotating head 88 and rotational adapter base 83 to predetermined angles relative to one another. Rotation head 88 is held to adapter base 83 by hex threaded fastener 87 along with biasing belleville washer 86 .
[0051] Referring to FIGS. 14 and 15 , they show an existing light fixture 101 with tombstone electrical fitting 102 along with light bar 1 . FIG. 14 and FIG. 15 depict how an existing light fixture 101 can be retrofitted with light bar 1 . Tombstone 102 could be used with a pair of adapter bases 14 , 15 or 16 attached to end base 2 , 3 of light bar 1 . In FIGS. 21 and 22 , tombstones 102 are left in place in fixture 101 , but not utilized. Light bar 1 is installed using clips 6 , 8 and self-tapping hex screws 53 , 54 . Power supply 103 is positioned and DC wires 104 are electrically interconnected to the circuitry in light bar 1 with quick connectors 105 and 106 .
[0052] Referring now to FIGS. 16 through 21 what is shown is an embodiment of a Clip 120 adapted for a wide light distribution and an embodiment of a Clip 130 adapted for a narrow light distribution. Turning to FIG. 16 , Clips 120 are integrated into a fixture 140 and adapted to hold light bars 1 at an angle relative to each other. In this illustrated embodiment the light bars 1 are at a 90° relative to each other, 45° relative to the fixture. Those of ordinary skill in the art will understand that the structure of the Clip 120 may be adapted for other angles as needed.
[0053] FIG. 17 is a side-view of the Clip 120 . The Clip 120 has legs 122 , 123 which are operable to flex slightly in the direction of arrows 129 and open as the legs 122 , 123 slide over metal extrusion 9 . The legs 122 , 123 are then biased allowing feet 124 , 125 to engage into grooves 31 , 32 of extrusion 9 (see FIG. 5 ) and hold light bar 1 in place. In one embodiment the leg 123 is longer than the leg 122 , and includes an extension 123 a such that the area defined by the legs 122 , 123 may receive hold the light bar 1 , though the light bar 1 may not fill a substantial portion of the area defined by the legs 122 , 123 .
[0054] Clip 120 has a Base Feature 126 and fasteners 127 , 128 that are adapted to fasten the Clip 120 to a fixture. In one embodiment the fasteners 127 , 128 are leaf springs. The Clip 120 may be inserted to a through-hole in the fixture 140 such that the back surface of the fixture 140 firmly abuts the top surface of the Base feature 126 , and fasteners 127 , 128 , which flex slightly, bias against the front surface of the fixture 140 , pinching the fixture 140 between the fasteners 127 , 128 and the Base feature 126 . Other fastening techniques known in the art may be used instead of or in addition to those described herein, by way of non-limiting example, adhesives, bolts, screws, and the like.
[0055] FIG. 18 is a perspective-view of the Clip 120 illustrated in FIG. 17 .
[0056] Referring now to FIG. 19 , what is shown is an embodiment of a Clip 130 adapted for a narrow light distribution. Clips 130 are integrated into a fixture 140 and adapted to hold light bars 1 vertically, parallel to each other.
[0057] FIG. 20 is a side-view of the Clip 130 . The Clip 130 has legs 132 , 133 which are operable to flex slightly in the direction of arrows 139 and open as the legs 132 , 133 slide over metal extrusion 9 . The legs 132 , 133 are then biased allowing feet 134 , 135 to engage into grooves 31 , 32 of extrusion 9 (see FIG. 5 ) and hold light bar 1 in place. In one embodiment the legs 132 , 133 are substantially the same length.
[0058] Clip 130 has a Base Feature 136 and fasteners 137 , 138 that are adapted to fasten the Clip 130 to a fixture. In one embodiment the fasteners 137 , 138 are leaf springs. The Clip 130 may be inserted to a through-hole in the fixture 140 such that the back surface of the fixture 140 firmly abuts the top surface of the Base feature 136 , and fasteners 137 , 138 , which flex slightly, bias against the front surface of the fixture 140 , pinching the fixture 140 between the fasteners 137 , 138 and the Base feature 136 . Other fastening techniques known in the art may be used instead of or in addition to those described herein, by way of non-limiting example, adhesives, bolts, screws, and the like.
[0059] FIG. 21 is a perspective-view of the Clip 130 illustrated in FIG. 15 .
[0060] Referring now to FIGS. 22A and 22B , which show the Clip 120 inserting into the through-holes 141 of the Fixture 140 . FIG. 22A is a perspective view of the Clip 120 being inserted into a through-hole 141 along a trajectory 142 . FIG. 22B illustrates the Clip 120 inserted into the through-hole 141 and fastened to the fixture 140 .
[0061] FIG. 23 illustrates a new fixture with an angled clip and a vertical clip installed and retaining LED light bars, according to an embodiment of the disclosure.
[0062] Once being apprised of this disclosure, one of ordinary skill in the art would be readily able to make and use the various embodiments of the disclosure. By way of non-limiting example, various embodiments of the disclosure facilitate ability to install light bars in fixtures to change light output, offer different kelvin options from stock that could be used as an LED light, quickly offer many different fixture types, facilitate procuring fixtures from many different sources, and change the beam pattern to meet utility requirements by utilizing clips without needing to change a fixture.
[0063] Various embodiments of the disclosure include both a method for the practice of replacing fluorescent tubular lamps with LED light bars while also describing the devices that provide the means of adapting the LED light bars into existing lamp fixtures.
[0064] Although operation illustrated by or in connection with FIGS. 1 through 23 and accompanying text recites acts performed in a particular order, embodiments of the present disclosure do not necessarily need to operate in that recited order. One of ordinary skill in the art would recognize many variations, including performing acts in parallel, or in a different order.
[0065] While certain illustrative embodiments have been described in connection with the figures, those of ordinary skill in the art will recognize and appreciate that the scope of this disclosure is not limited to those embodiments explicitly shown and described in this disclosure. Rather, many additions, deletions, rearrangements and other modifications to the embodiments described in this disclosure may be made to produce embodiments within the scope of this disclosure, such as those specifically claimed, including legal equivalents. In addition, features from one disclosed embodiment may be combined with features of another disclosed embodiment while still being within the scope of this disclosure, as contemplated by the inventors. As such, the invention is not to be defined only by the preceding illustrative description, but only by the claims which follow, and legal equivalents thereof. | Embodiments of the disclosure relate to retrofitting LED light bars into fluorescent tubular style lamp fixtures as well as integrating LED light bars into new lamp fixtures. In various embodiments a single light bar may be utilized with multiple style base ends to allow it to retrofit into a variety of existing fixtures. Some embodiments offer multiple mounting options on an LED light bar for existing lamp fixtures so that electrical utilities' rebate requirements can be met with a single LED light bar assembly. | 5 |
This is a division, of application Ser. No. 238,141, filed Mar. 27, 1972, now U.S. Pat. No. 3,826,928, which was a division of application Ser. No. 62,869, filed Aug. 11, 1970, now U.S. Pat. No. 3,678,355, which are both incorporated by reference herein.
BACKGROUND OF THE INVENTION
As disclosed by U.S. Pat. Nos. 3,678,355 and 3,826,928, it is desirable to provide an A.C. motor control using solid state technique to acquire a tight, sophisticated control of motor acceleration, deceleration and programmed speed which, to all intents and purposes, eliminates lag in motor response to change speed signals in the control system. The desired result is instantaneous response in motor power or electrical braking, such as could be advantageously utilized in elevator motors.
The control circuit therefore provides motor directional and speed reference signals as voltages shaped into a smooth linear ramp summed with a feedback signal which is responsive to motor speed and direction. It is desirable for the amplitude and polarity of the amplified error to control the current flow and reversing of phase rotation, respectively, in at least two of the three phase motor inputs through fast responding, solid state trigger circuits controlling thyristor switches. Motor direction and speed conditions are sensed by a special A.C. tachometer and feedback circuit which feeds into the feed control circuit, as described above. The A.C. tachometer with a direction and speed sensing circuit is the subject matter of and is fully disclosed in a copending application Ser. No. 875,193, filed Nov. 10, 1969, now U.S. Pat. No. 3,614,616.
SUMMARY
Accordingly, a primary object of the present invention resides in providing a universal solid state trigger circuit which provides positive going output trigger pulses for turning on an independent thyristor for each half cycle of an alternating phase load channel. The trigger circuit includes a bi-stable, multi-vibrator circuit whose "set" and "reset" inputs are controlled by timing pulses derived from each half-cycle of the phase input to the controlled phase channel Speed signals are compared, shaped and via AND gates and amplifier circuits provide cycle chopping trigger output pulses for each one-half cycle to control current flow through thyristor circuits during each half-cycle of an input phase.
DESCRIPTION OF DRAWINGS
FIG. 1 is a block diagram illustrating a control circuit for a three phase A.C. elevator motor in which the present invention may be utilized.
FIG. 2 is a schematic diagram of the preferred triggering circuit of the present invention.
FIG. 3 is an exemplary wave form chart illustrating timed signals at various points in the trigger circuit.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The invention of U.S. Pat. Nos. 3,826,928 and 3,678,355 is described as incorporated in a control system for use with a three phase A.C. motor elevator drive and eliminates the motor generator set used to convert A.C. power to D.C. power for operating a D.C. elevator drive as is used in most high speed elevators. It is to be understood that the system can be used to control other three phase A.C. motor applications.
The control system for the A.C. motor drive involves starting, running and stopping the elevator lifting motor in a manner which avoids the discomfort of abrupt transitions in speed. The motor control will be described primarily with reference to the block diagram seen in FIG. 1 although specific references will, at times, be made to the triggering circuitry in the schematic drawing FIG. 2 and the timing chart of FIG. 3. A more detailed understanding of the entire circuitry for the motor control is provided in U.S. Pat. Nos. 3,678,355 and 3,826,928 as mentioned hereinabove.
Referring to FIG. 1, an elevator run will be initiated by the supervisory system by depressing a control button (not shown) in the elevator car or at a landing. This actuates the elevator switching logic 20 which produces a predetermined D.C. voltage signal on its output 22, which is connected to and provides an input to the function generator error amplifier 24. The amplitude of the voltage output signal developed by switching logic control 20 will determine the maximum speed to which the car can accelerate during the desired run and the slower levelling speed as the car approaches the selected landing. For multi-floor runs the elevator logic signal will have an amplitude which permits the elevator to accelerate to its highest speed. For single floor run the control voltage amplitude will be less, permitting acceleration to a fraction of the highest speed. The supervisory control also provides an output signal at other predetermined levels indicative of approach or levelling speeds; also provides a signal indicative of zero speed or stop condition and which applies and releases the elevator floor holding brake; and also provides via, up and down relays 26 and 28, a direction control for elevator drive.
The output on line 30 from the function error amplifier 24 is integrated in a function generator 32 at an adjustable preset rate. As the function generator signal on output 33 integrates upward in amplitude, that output signal on a parallel connection 34 is fed back to the function error amplifier 24 to oppose the input signal at a summing junction. The output signal of the function generator then remains at a level indicative of desired until the elevator logic dictates otherwise.
The function generator output signal, designated as the output ramp, is fed on line 33 to the ramp switching circuit 36 which includes relay contacts which, depending upon which of the "up" and "down" relays 26 and 28 is energized, provides a control signal to one or the other input of an amplifier inverter stage 38. Depending on the condition of the "up-down" relay contacts in the ramp switching circuit 36, the inverter output signal will either be a positive ramp or a negative ramp.
Coupled directly to the three phase drive motor shaft is a two phase A.C. tachometer 61 which supplies both motor speed and motor direction information to the system. An output signal proportional to motor speed is obtained by rectifying and combining the two phase tachometer output, as is fully described in the aforedescribed copending application. This signal is positive for one direction of rotation of motor 60 and negative for the other direction of rotation. The polarity reversal is accomplished by the tachometer switching circuit 50. The tachometer feedback signal is fed to a summing junction, at the input to the error regulator amplifier 42.
The system can be best described in conjunction with an example. If the elevator is programmed to go up one floor by the elevator switching logic, that condition will produce a positive going ramp of a predetermined amplitude as the output on line 39 from the amplifier/inverter stage 38. This signal is fed to the summing junction at the input of the regulator amplifier 42. As was previously described, also fed to this same summing junction is a D.C. feedback signal on line 44 from the tachometer switching circuit. The polarity of the tachometer feedback signal is determined by the tachometer direction sensing circuit 48 and tachometer switching circuit 50, such that it will buck out the positive ramp on line 39 from inverter 38 when the elevator is programmed to go up. When the elevator is programmed to run the opposite direction, via the supervisory logic relays 26 and 28, and associated up or down relay switching contacts, the polarity of both of these signals is reversed and the tachometer signal will still buck out the ramp from inverter 38.
The difference signal from this summing process, which can be positive or negative, is amplified and inverted through the regulator amplifier 42. In all cases if the output signal from the regulator amplifier 42 is negative it is an effective up signal and if positive it is an effective down signal to the motor power controlling circuits. It should be noted that an up signal from the regulator 42 will not necessarily drive the elevator up, but can be a braking signal during a downward elevator drive. During a normal run the drive motor 60 might be receiving both up and down signals even though the elevator is moving in one direction. This provides the required control of the system.
A three-phase power source, through suitable circuit brakers and switches, provides A.C. drive power and, via transformers and rectifier circuits provides power and timing for the control system. The main lines for phases A, B and C, designated 62, 64 and 66, are connected through thyristor control and switching circuits to the three-phase input lines 68, 70 and 72 to motor 60. Each of at least two of the main lines, e.g., phases A and C, can be selectively connected to an associated pair of the three input lines to the three-phase motor 60, or can be reversely connected to the same pair of input lines to respectively provide drive or braking power in both directions of motor rotation.
The three phase A.C. input, via the transformers and full wave rectifier circuits, provides a regulated D.C. supply for the control system. Center tapped secondaries in transformer phases A and C provide cycle timing signals used by the thyristor trigger circuits, as will be further described.
Phase A, via power line 62, connects through dual inverse parallel thyristor control circuits 74 and 76 to respective motor input leads 68 and 72 and phase C, via line 66, connects through dual inverse parallel thyristor control circuits 78 and 80 to respective motor input leads 72 and 68. Each dual thyristor control circuit has two thyristors connected in parallel, but in opposed directions to enable controlled current flow in both directions, i.e., during each half cycle, if an appropriately timed trigger pulse is applied to the control electrode of the thyristor for that half cycle of that phase channel.
Circuit 74 includes inverse parallel thyristors 82 and 84 and is designated up control for phase A. Circuit 76 includes inverse parallel thyristors 86 and 88 and is designated the down control for phase A. Circuit 72 includes thyristors 90 and 92 in inverse parallel arrangement and is designated the up control for phase C. Circuit 80 includes thyristors 94 and 96 in inverse parallel arrangement and is designated the down control for phase C.
Each thyristor has trigger (or control) leads connected to associated trigger circuits, as will be more fully described hereinafter.
It is necessary to prevent both the up channel and the down channel in each of the phase A and phase C current supplies to both the A and C phase windings of the motor 60 from being turned on at the same time. If that were to happen, the three-phase input line currents would become excessively large, and possibly damage the thyristors in the up and down phase switching channels. To prevent that from happening, the motor drive or braking current is sensed by current transformers 100 and 102 in the up and down channel of one of input phases A or C. The sensed up or down current flow information is fed via a logic circuit 104 or 106, respectively, to associated safety lockout circuits 108 and 110 which operate to prevent turning on of the down channel while the up channel is turned on and vice versa.
The amplitude of the output signal from the error (or regulator) amplifier 42, the amplitude of which represents the variation in high or low motor speed relative to the desired speed is connected, via line 112, through directional diodes as inputs to one or the other of the lockout circuits 108 and 110 and thence, as permitted by one of the lockouts 108 or 110, to up trigger circuits 114 and 118 of down trigger circuits 116 and 120. A negative or up signal on input 112 provides a signal from the up lockout circuit 110, via its amplifier on parallel connection lines 122 and 124, to drive the two up channel trigger circuits 114 and 120 directly, while a positive or down signal from the regulator amplifier 42 to the down lockout 108 provides a signal on its output which must be inverted through inverter amplifier 128 and thence, via parallel connection lines 130 and 132, to drive the down channel trigger circuits 116 and 118.
Rectified signals from the up and down channel current transformers 100 (up) and 102 (down) ground any incoming signals to respective lockout circuits 108 (down) and 110 (up), so the function error signals on line 112 can have no effect on the signal lockout amplifier if current is sensed in the down channel and vice versa. Each of the lockout amplifiers when subjected to a signal output will provide an amplified output signal between fixed positive and negative levels which, in the exemplary control system, is selected as from +10V to -10V. When either circuit 108 or 110 is locked out, or the error signal on line 112 is zero, the respective amplifier of the circuit will transmit a maximum positive level signal, and for a full power error signal on line 112 (either full negative or full positive) the safety interlock output signal from the appropriate one or the other of amplifiers will be full negative. Adjustable resistors in the input circuits of respective interlock amplifiers enable adjustment of their outputs for a zero signal input.
The safety interlock down output is parallel connected via lines 130 and 132 to the two trigger circuits 116 and 120 of trigger boards 1 and 3 to drive in appropriate timed relationship to the phase cycles, the down thyristors (86 and 88) (94 and 96) in each channel of the respective A and C phase input lines to motor 60, to provide variable down power in two legs of the three-phase line power connection to the motor. Similarly, the safety interlock up output is parallel connected via lines 122 and 124 to the two trigger circuits 114 and 118 of trigger boards 2 and 4 to drive, in appropriate timed relationship to the phase cycles, the up thyristors (82 and 84) (90 and 92) in each channel of the respective A and C phase input lines to motor 60 to provide variable up power in two legs of the three-phase inputs to the motor.
The trigger circuits 118, 120, 116 and 114 of respective trigger boards 1, 2, 3 and 4 are identical and the boards are interchangeable. The circuit components are assembled on a printed circuit board with plug-in terminals. For convenience in drawing disclosure, boards 1, 2 and 3 are shown in block form and the trigger board circuit 114, which is the same as the circuit for all trigger boards, is disclosed in detail for trigger board 4 in FIG. 2. All boards have identical plug-in terminals and similar letter references are shown for comparison purposes on trigger boards 1, 2, 3 and 4. Terminals D, E, F, P, R and T are terminal connections to various voltage levels (as indicated on the drawing) from the power supply. Terminals N and V provide connections to selected phase channels for receiving cycle timing signals corresponding to the A.C. wave forms of the respective phases. Terminal J provides the connection for the input control signal (from the safety interlocks) to the trigger board. Terminals X and Y are isolated output terminals for one-half cycle thyristor triggering, while terminals C and B provide the isolated output circuit for the other half cycle triggering of the opposed thyristor in the associated up or down thyristor switching device for that phase channel.
A wave form timing chart for a trigger board is seen in FIG. 3. The voltage wave form at the top represents the sine wave for a specific A.C. phase channel applied to the thyristor switching device and to the primary windings of the power supply transformer corresponding to that phase. An associated center tap secondary for that phase transformer provides a pair of independent sine wave signals, 180° out of phase with each other, via connections to respective terminals N and V, the input timing terminals for a registor 160 (bi-stable multivibrator) on the trigger board.
Assuming an input signal on terminal N will set the registor, an appropriate input signal applied to terminal V will reset the register. Thus, every time a positive half cycle is applied to terminal N, the register will go to a set condition, its transistor Q1 will be turned on and its output junction A1 will go from positive to ground. Each time the cycle signal applied to terminal V gear positive, transistor Q2 is turned on and transistor Q1 is turned off, causing junction A2 to go from positive to ground and junction A1 to go from ground to positive.
Via differentiating capacitor-diode circuits 162 and 164, the negative going transitions appearing at junction A1 and A2 provide a signal wave form at junction A, having negative going timing spikes corresponding to the beginning of each half cycle of the associated A.C. phase. The negative going timing pulses at junction A are used to control an integrator reset circuit 166 which includes transistor Q3. Viewing FIGS. 2 and 3, each time a negative going spike appears at junction A, the integrator reset transistor Q3 is turned on and provides a positive voltage level (+10V) at junction C which resets the threshold voltage of integrator 168 at that positive level. The integrator integrates from +10 to -10 Volts during the time period for a half cycle. The amplified speed error control signal, from the up interlock circuit 108, which is transmitted on line 124 to terminal J, modifies the integrated saw tooth voltage output from integrator 168 at a summing junction E.
If the control signal applied to terminal J indicates a no power condition, a fully amplified positive signal (e.g., -10V in this specific case) from the safety interlock up circuit 110, that voltage level applied to summing junction E will keep integrated (saw tooth) voltage levels above ground level during the entire integrating period. Junction E is connected to the inverting input of an operational (high gain) amplifier 170 whose output has a range from negative (-10V) to positive (+10V). As long as the voltage signal at junction E is positive, the output of the comparator inverter 170 at junction G is at negative saturation, i.e., -10V. Whenever the signal level at junction E goes below zero to negative, the output of the comparator 170, junction G, goes full positive (+10V).
The wave form at the comparator output (junction G) is a square wave, the widths of the positive periods of which represent the desired conduction angle with the time correlated A.C. half cycles in the associated phase channel.
When the signal on input terminal J represents full power, (right hand portion of FIG. 3), in other words, it is at its -10V level, the effective integrated saw tooth wave form applied to comparator inverter 170 is negative during the entire integrating time period, causing the comparator 170 to provide a fixed positive level output for the entire half cycle time period.
Any intermediate signal level applied to terminal J of the trigger board will modify the saw-tooth wave form at the summing junction E to form somewhere between the full off and full on conditions shown in FIG. 3. The middle portion of the FIG. 3 chart shows an example of such an intermediate condition, a half conducting angle condition, wherein the (0) Volt control signal at terminal J causes a wave form at junction E which is negative during the last half of each half cycle. That negative input to the comparator 170 provides positive square waves on its output to junction G during the last half of each cycle period.
The square wave signals from the trigger circuit comparator 170 are applied through amplifier transistor Q4 and the resulting positive level signals on the emitter of Q4 are used to provide appropriately timed trigger signals to both of the inverse parallel thyristors in an associated thyristor switching device, e.g., device 76. The emitter of Q4 is connected to drive respective power amplifiers 172 (transistor Q5) and 174 (transistor Q6) via a parallel input circuit. Transistor Q5 is inhibited by an Inhibit Gate 176 whenever the junction A 2 is positive (during a negative half cycle of the associated A.C. phase) and transistor Q6 is inhibited by an Inhibit Gate 178 whenever the junction A 1 is positive (during a positive half cycle of the associated A.C. phase). Power transistor Q5 can only be turned on during one (positive) half cycle of the associated A.C. phase and is only turned on during the related period when the output transistor Q4 is on. Similarly, Power transistor Q6 can only be turned on during the other (negative) half cycle of the associated A.C. phase and is only turned on during the related period when the output transistor Q4 is on.
As shown in FIG. 3, the outputs of power amplifiers 172 and 174 are square waves, the positive voltage levels of which occur for desired, controlled periods during associated half cycles and always terminate at the end of a half cycle. As shown in FIG. 2, the collector-emitter circuits of each power amplifier transistor Q5 and Q6 is series connected with the primary winding of an associated isolation square wave transformer. Q5 operates transformer 180 and Q6 operates transformer 182. The two leads of the secondary winding of transformer 180 connect through plug board terminals C and B to the trigger circuit of the half cycle (in the example, the positive half cycle) switching thyristor 92 and the two leads of the secondary winding of transformer 182 connect through plug board terminals x and y to the trigger circuit of the other of the half cycle (e.g., the negative half cycle) switching thyristor 90.
The isolation transformers 180 and 182 are square wave transformers and thus provide square wave trigger signals to turn on the associated thyristors 92 and 90 substantially instantaneously with the positive going transition of the isolation transformer output to its full positive voltage level, providing accurate control over desired conduction angle of the associated phase half cycle.
The foregoing trigger circuit description was made in connection with the up channel of phase C and shown how each half cycle of the A.C. phase wave in that channel will be controlled through its associated thyristor to provide a conduction angle determined by the output signal from the trigger board comparator 170, as driven by the control signal on the up interlock output lines 122 and 124. The same control signal is used to drive the phase A up trigger board circuit which, in accord with phase A cycle timing signals, will trigger the inversed parallel thyristor 82 and 84 of the phase A up channel thyristor switching device 74, at appropriate desired periods, within the positive and negative half cycles. If the interlock output control signal calls for down power the two down trigger board circuits 116 and 118 will trigger their associated thyristor devices in accord with associated phase cycle timing signals.
The various values of voltage resistance and capacitance in the described embodiment are exemplary of an operative circuit and can be changed in known manner by persons skilled in electrical circuitry and remain within the inventive concept.
The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. | A solid state trigger circuit provides variable period output signals within a timed sequence of signals for controlling conduction angle firing of thyratron type switching devices in an A.C. phase line. A bi-stable multivibrator receives timing signals derived from the alternating current in the phase line which are out of phase with each other. The timing signals oscillate the multivibrator at a desired timing rate to produce an output of the multivibrator which has voltage transition spikes at the beginning of each positive circle of the timing signals. A saw tooth wave form with a linear voltage input control signal indicative of a desired time period pulse width provides a square wave trigger output signal with signal pulse periods equal to the desired pulse width. | 1 |
BACKGROUND OF THE INVENTION
The present invention relates to a capacitor discharge ignition system for a multicylinder internal combustion engine.
A conventional capacitor discharge ignition system for a multicylinder internal combustion engine necessitates an exciter coil for charging the capacitor and a signal coil for supplying a turn-on signal to a thyristor which enables discharge of the capacitor. The exciter coil and the signal coil are provided in a multipolar magneto AC generator driven by the engine. The signal coil provided in a multipolar generator produces a turn-on signal a plurality of times during one revolution of the crank shaft of the engine so that a spark occurs at the ignition plug of each cylinder a plurality of times per revolution of the crank shaft. The fact that a spark occurs a plurality of times per revolution is particularly undesirable with a four-cycle engine because such occurrence will reduce the engine output. Another conventional ignition system employs a special signal source which is adapted to produce a signal once per revolution. However, signal output produced by such a signal source is of a short duration, so that it places a limitation to the range of ignition angle variation with engine speed which is often required.
SUMMARY OF THE INVENTION
An object of the present invention is to provide an ignition system wherein a spark occurs once per revolution of the engine, thereby avoiding reduction of the engine output while the range of ignition angle variation can be made sufficient.
An ignition system according to the present invention comprises first to n-th (n being an integer greater than unity) ignition coils respectively provided in conjunction with first to n-th cylinders of the multi-cylinder internal combustion engine, first to n-th capacitors respectively provided on the primary sides of the first to n-th ignition coils, at least one power source for charging the first to n-th capacitors, and first to n-th semiconductor switches with a control terminal provided on the primary sides of said ignition coils and adapted to be turned on for discharging the capacitors through the first to n-th primary windings of the first to n-th ignition coils. The ignition system is characterized by further comprising a turn-on signal source for providing a turn-on signal at least n times per revolution of the engine output shaft at the rotational angles at which ignition is expected in any of the cylinders, first to n-th trigger signal sources for providing a trigger signal in sequence, each of the trigger signal sources being adapted to generate a trigger signal in advance of the maximally advanced ignition angle of the associated one of the first to n-th cylinders, and first to n-th gate circuits, each being adapted to be opened upon receipt of the trigger signal from the associated one of the trigger signal sources to enable the turn-on signal to be applied to the associated one of the semiconductor switches. The turn-on signal source may comprise a signal coil provided in an AC generator rotating in synchronism with the engine to generate an AC signal of a relatively long duration. The combination of the gate circuits, the trigger signal sources and the turn-on signal sources makes it possible to cause ignition only once per revolution of the engine output shaft. The turn-on signal source is capable of producing a turn-on signal at an angle varying with engine speed, and as a result various ignition angle characteristics as desired can be readily obtained.
BRIEF DESCRIPTION OF THE DRAWINGS
Other features and advantages of the present invention will be apparent from the following description taken in conjunction with the accompanying drawings in which;
FIG. 1 schematically shows the general construction of an embodiment of the present invention,
FIG. 2 shows a sectional view showing a preferable example of a generator suitable for the present invention,
FIG. 3 shows a specific embodiment of the present invention,
FIGS. 4(A) through (N) show waveforms of the signals at various portions of the system of FIG. 3,
FIG. 5 shows part of waveforms illustrative of angle advance of the system of FIG. 3,
FIG. 6 shows an example of angle advance characteristic obtained by the system of FIG. 3,
FIG. 7 shows another embodiment of the invention, and
FIGS. 8(A) through (N) show waveforms of signals at various portions of the system of FIG. 7.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Although the invention is applicable to an ignition system having n(n being any integer greater than unity) cylinders, for the sake of simplicity, the following description will be made with reference to an engine with three cylinders.
FIG. 1 schematically shows the general construction of an ignition system according to the present invention. The ignition system comprises first to third ignition coils 101a-101c provided in conjunction with first to third cylinders, not shown, and first to third ignition plugs 102a-102c connected to the secondary of the ignition coil 101a-101c. The primary windings of the ignition coils 101a-101c have first ends thereof grounded and second ends connected to first terminals of first to third capacitors 103a-103c. Second terminals of the capacitors 103a-103c are respectively connected to the anodes of the thyristor 104a-104c, whose cathodes are grounded. Thus, the ignition coils 101a-101c, the capacitors 103a-103c and the thyristors 104a-104c form first to third capacitor discharge ignition circuits 100a-100c. Operation of each of the capacitor discharge ignition circuits comprises, as is known in the art, charging of each of the capacitors by a power source which will be described later, and turn-on of each of the thyristors 104a-104c for discharging the capacitor through the primary of the associated ignition coil, the discharge inducing a high voltage in the secondary and therefore firing of the ignition plug.
The ignition circuits 100a-100c are associated with a power source and turn-on signal source. In the embodiment illustrated, the power source comprises an exciter coil provided in an AC generator which is driven to rotate in synchronism with the engine, the output of the exciter coil being applied through each of first to third diodes 152a-152c across each of the series connection of the capacitors 103a-103c and ignition coils 101a-101c, to charge the capacitors into the polarity as indicated by "+" and "-" in FIG. 1. The turn-on signal source of the embodiment comprises a signal coil 161 also provided in the same generator as the exciter coil 151. The signal coil 161 is designed to produce a signal output of at least 3 cycles (3 being the same number as the number of the cylinders of this embodiment) per revolution of the output shaft of the engine. The output of the signal coil 161 is supplied to a turn-on signal generating circuit 162. The turn-on signal generating circuit 162 preferably generates a turn-on signal once per cycle of the output of the signal coil. The turn-on signal is supplied through first to third gate circuits 163a-163c to the gates of the thyristors 104a-104c. To open each of the gate circuits 163a-163c within selected periods first to third pulser coils 164a-164c are provided to act as trigger signal sources. Each of the pulser coils generates a signal which is applied to the associated gate circuit once per revolution of the output shaft of the engine at an angle slightly advancing the maximally advanced ignition angle of the cylinder. Each of the gate circuits is constructed to be opened or to be enabled for a predetermined period upon receipt of a trigger signal. The turn-on signal from the turn-on signal generating circuit 162 is supplied through the gate circuit which is being enabled to the associated thyristor. By properly determining the sequence of enabling the gate circuits, and more particularly by opening each of the gate circuits at an angle slightly advancing the maximally advanced ignition angle relative to the top dead center of the piston and closing the gate circuit after the turn-on signal has passed, each cylinder will have a spark caused once per revolution.
The turn-on signal generating circuit 162 is adapted to generate a pulsative turn-on signal when the instantaneous value of the output voltage of the turn-on signal coil exceeds a predetermined level. The amplitude of the output of the signal coil provided in a generator rotating in time with the engine becomes larger with increase of the engine speed, so that the turn-on signal is generated at an angle more advanced with increasing engine speed. The thyristors are therefore turned on at an angle more advanced with increasing engine speed, and consequently ignition angle advance is achieved.
The invention will now be described with reference to a specific example. FIG. 2 shows a magneto AC generator suitable for a power source and a turn-on signal source. The generator comprises a substantially cup-shaped flywheel 1 formed of a magnetic material, and arcuate permanent magnets 2,2 . . . mounted and spaced equally from each other on the inner surface of the peripheral wall of the flywheel. The magnets are so polarized that N- and S-poles appear alternately on their inner surfaces. Pole pieces 3,3 . . . are fixed on the inner surfaces. The flywheel, the magnets and the poles pieces form part of a six-polar rotor. The rotor is usually coupled to a crank shaft of the engine. The generator further comprises a stator 4 which comprises a substantially star-shaped core 5 and armature coils 6a-6f. The stator 4 may be fixed, for instance, to the case of the engine. In the embodiment illustrated, the armature coil 6a is utilized as the exciter coil 151, and the armature coil 6e which is positioned 120° (mechanical angle) apart from the armature coil 6a and which therefore produces an output of the same phase as the coil 6a is utilized as the turn-on signal coil 161. The rest of the armature coils 6b-6d and 6f are used to energize head lights of the vehicle and other loads.
The flywheel 1 is provided with an opening 1a in the peripheral wall. A spacer 7 of a non-magnetic material is fitted in the opening. One of the pole pieces 3,3 . . . has an extension 3a extended first in an direction parallel to the flywheel periphery and then radially outward to penetrate through the spacer 7 and to have the end exposed outside the flywheel. Outside the flywheel are so positioned substantially U-shaped cores 8a-8c that a pair of legs of each of the cores simultaneously confront the exposed end of the extension 3a and the outer surface of the flywheel 1, and that the cores are distanced 120° (mechanical angle) apart from each other. The cores 8a-8c have pulser coils 164a-164c mounted thereon respectively.
FIG. 3 shows a specific example of an ignition system generally shown in FIG. 1, and more particularly the specific construction of the turn-on signal generating circuit 162 and the gate circuits 163a-163c. The turn-on signal generating circuit 162 comprises a first transistor 10 having its collector coupled through a resistor 12 to a DC power source Vcc, a second transistor 11 having its collector coupled through a resistor 13 to a DC power source Vcc and its base coupled directly to the collector of the first transistor 10, a capacitor 15 having one of its terminals connected to the base of the first transistor 10, a thyristor 16 having its cathode connected to the other terminal of the capacitor 15 and its anode connected to the emitters of the transistors 10 and 11, a Zener diode 17 having its anode and cathode connected respectively to the gate and anode of the thyristor 16, and a variable resistor 18 connected across the cathode and anode of the thyristor 16, and a diode 19 inserted to rectify the output of the signal coil 161 to enable charging of the capacitor 15 into the polarity as indicated by "+" and "-" in FIG. 3.
The gate circuits 163a-163c comprises first to third flip-flops 165a-165c, respectively, and AND gates 166a-166c, respectively, having one of their input terminals coupled to the Q-terminals of the flip-flops, and the other input terminals coupled to receive the turn-on signal from the turn-on signal generating circuit 162. "Rest" terminals R of the first, second and third flip-flops 165a-165c are coupled to "set" terminal S of the second, third and first flip-flops, respectively.
In the embodiment illustrated, first to third wave shaping circuits 167a-167c are provided to form part of the trigger signal sources to shape the output voltage from the pulser coils 164a-164c into pulsative trigger signals. Each of the wave shaping circuits comprises a first transistor 20 having its collector connected through a resistor 22 to a DC power source Vcc and its base connected through a resistor 24 to the DC power source Vcc, a second transistor 21 having its collector connected through a resistor 23 to the DC power source Vcc and its base connected directly to the collector of the first diode, and a diode 25 connected across the base and emitter of the transistor 20. Each of the pulser coils 164a-164c is connected through a diode 26 across the base and emitter of the first transistor 20.
FIGS. 4(A) through (N) show waveforms of the signals appearing at the portions indicated by a through n in FIG. 3. As the flywheel 1 rotates, for instance in a direction shown by the arrow in FIG. 2, the exciter coil 151 induces an AC voltage Ve having a frequency of 3 cycles per revolution. During the positive half cycle of the voltage Ve, current flows through the diodes 152a-152c and the primary windings of the ignition coils 101a-101c to charge the capacitor 103a-103c. During the negative half cycle, the output of the exciter coil 151 is obstructed by the diodes 152a-152c. The signal coil 161 produces a voltage Vs in phase with the exciter coil. The voltage Vs has a waveform as shown in FIG. 4(A). The positive output of the voltage Vs is obstructed by the diode 19. When the negative output is produced, current flows through a path including the resistor 14 and the diode 19 to charge the capacitor 15 into the polarity as indicated by "+" and "-" in FIG. 3. As the voltage across the capacitor 15 exceeds a certain value the Zener diode 16 breaks down and the thyristor 16 is turned on, so that the capacitor 15 is discharged through two paths, one of which includes the resistor 14 and the thyristor 16 and the other of which includes the base and emitter of the transistor 10 and the thyristor 16. The transistor 10 thereby becomes conductive which in turn makes the transistor 11 non-conductive, with the result that the potential at the collector of the transistor 11 rises. When the discharge of the capacitor 15 is completed the transistor 10 becomes nonconductive to make the transistor 11 conductive, so that the collector potential thereof returns to zero (ground potential). Since the discharge of the capacitor 15 is completed within a short period, a voltage obtained across the collector indicated by b of the transistor 11 and the ground during the discharge has a short duration as shown in FIG. 4(B). The voltage Vb is used as a turn-on signal to turn on the thyristors 104a-104c. The angle at which the voltage Vb rises determines the ignition angle.
In the turn-on signal generating circuit 162, the turn-on signal Vb is produced when the output voltage Vs of the signal coil 161 reaches a certain level necessary to turn on the Zener diode 17.
As is shown in FIG. 5, as the engine speed is increased from N 1 to N 2 , and to N 3 (N 1 <N 2 <N 3 ) the angle at which the signal Vb is produced advances from θ 1 to θ 2 , and to θ 3 . Since the signal Vb determines the angle at which the thyristors 104a-104c conduct, the advance angle in relation to the top dead center of the piston advances with the engine speed as shown in FIG. 6.
In the arrangement of FIG. 3, the pulser coils 164a-164c produce trigger signals V p1 -V p3 , as in FIGS. 4(C)-(E), having short duration at angles in advance of the ignition angles of the associated cylinders. The signals V p1 -V p3 are shaped in the wave shaping circuits 167a-167c. More particularly, when each of the pulser coils produces a positive output indicated by arrows of a solid line, the diode 26 is reverse-biased and the transistor 20 is provided with a base current through the resistor 24 and thereby becomes conductive with the result that the transistor 21 becomes nonconductive, so that the collector potential of the transistor rises. While each of the pulser coils produces no output or negative output the base and emitter of the transistor 20 is effectively shunted, so that the transistor 20 remains nonconductive and the collector potential of the transistor 21 remains at zero. Consequently, the wave shaping circuits 167a-167c produce pulsative signals Vf-Vh as shown in FIGS. 4(F)-(H) while the pulser coils produce positive output. As the pulsative signal is applied to set terminal to either of the flip-flops 165a-165c, the flip-flop which has been set will have the potential at its Q terminal rise to serve as an enabling signal to be supplied to the AND gates.
The flip-flops 165a, 165b and 165c are respectively reset by set signals of the flip-flops 165b, 165c and 165a. As is shown in FIGS. 4(I)-(K) each flip-flop therefore produces an enabling signal for 120° (in mechanical angle) starting at an angle when the associated pulser coil supplies a set signal and ending when the adjacent flip-flop is subsequently set. Each of the AND gates 166a-166c produces output only when it concurrently receives the enabling signal from the associated flip-flop and the turn-on signal Vb. Consequently, each of the thyristor 104a-104c receives a gate signal once per revolution as shown in FIGS. 4(L)-(N), and ignition is effected once per revolution. Since the turn-on signal Vb is provided at more and more advanced angle with increasing engine speed, the ignition angle of each cylinder advances with increasing engine speed as shown in FIG. 6.
It has been described above that the ignition system has an ignition angle characteristic wherein ignition angle simply advances with engine speed. However, the invention is not limited to the embodiment described above, but is applicable to ignition systems having various ignition angle characteristics. For examples, the ignition angle may be retarded with increasing engine speed by having the output of the signal coil shunted to postpone the charging of the capacitor 15, or by inserting a phase shifting circuit between the turn-on signal coil and the turn-on signal generating circuit.
Each of the gates 163a-163c may be composed differently from that shown in FIG. 3, and may comprise any device which opens at an angle slightly advancing the maximally advanced angle of each cylinder and closes in advance of the ignition angle of each cylinder. For example, in place of the flip-flop as in FIG. 3, a mono-stable multivibrator may be employed.
As can been seen in FIG. 7, the output of the signal generating circuit 162 may be supplied to reset terminals R of the flip-flops 165a-165c, and the output at the Q terminals may be transferred to differentiation circuits 168a-168c, and further to diodes 169a-169c. This arrangement eliminates the AND gates of FIG. 3. The waveforms of the signals at various portions a through n of the arrangement of FIG. 7 are shown in FIGS. 8(A)-(N).
In the embodiments described above, the output of the signal coil 161 is supplied to the turn-on signal generating circuit 162 and converted to a pulsative signal there. The output of the signal coil 161 may alternatively be supplied directly to the gate circuits 163a-163c, and further to the thyristors 104a-104c.
In the embodiments described, the thyristors 104a-104c are used to enable the discharge of the capacitors 103a-103c. It should however be noted that any type of semiconductor switches such as transistors may be used.
In the embodiments described, the exciter coil 151 is used as a power source for charging the capacitors, but the invention is also applicable to a system employing batteries as the power source.
In the embodiments described, the signal generator shown in FIG. 2 is used as part of the trigger signal sources, but those skilled art will readily appreciate that other types of signal generators may be substituted. An example of a known type of signal generator is one having an inductor which causes variation of the magnetic flux interlinking with pulser coils.
The wave shaping circuits 167a-167c may be omitted so that the output of the pulser coils is supplied directly to the gates 163a-163c.
It should also be noted that the positioning of the capacitors 103a-103c and the thyristors 104a-104c may be reversed; that is, the capacitors may be positioned where there are thyristors in FIG. 1 and the thyristors may be positioned where there are capacitors in FIG. 1.
While there have been described what are at present considered to be the preferred embodiments of the present invention, it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the invention, and it is aimed, therefore, in the appended claims to cover all such changes and modifications as fall within the true spirit and scope of the invention. | An ignition system for a multicylinder internal combustion engine comprising a turn-on signal source for producing a turn-on signal a plurality of times per revolution of the engine output shaft, a plurality of trigger signal sources each producing a trigger signal once per revolution, and a plurality of gate circuits enabled by the trigger signal to permit the application of the turn-on signal to the associated one of a plurality of capacitor discharge ignition circuits. Thus each ignition circuit operates once per revolution. The turn-on signal is produced at angles varying with the engine speed, and various ignition angle characteristics can be obtained. | 5 |
BACKGROUND OF THE INVENTION
This invention relates to picking tools, and more particularly for a manual picking tool having a changeable head contact portion and improved operation.
Tools for picking up items incorporate an articulatable gripping head portion with an elongate pole portion having an actuator at the end distal from the head, so that a user can hold the tool with one hand and actuate the head to close and clamp onto an item, for picking the item up by use of the same hand. This keeps the other hand free, which can be used to retrieve the item from the picking tool, if desired. Typical uses include picking up items from the ground, such as litter, for example, and for grasping items that would otherwise be out of reach, for example, items stored on shelves.
Some picking tools employ an actuator requiring the user to operation the tool by closing the fingers of one hand as a group, drawing the fingers toward the palm. However, since the same hand is holding the picking tool, this manner of operation puts an amount of strain on the user's wrist, such that long term use is uncomfortable, or such that the weight of items that can be picked up without wrist strain or pain is reduced considerably.
SUMMARY OF THE INVENTION
In accordance with the invention, an improved picking tool employs a trigger style actuator handle, and a head portion having changeable end portions to enable changing of the configuration of the grasping end of the picking tool for different uses.
Accordingly, it is an object of the present invention to provide an improved picking tool having a variable end portion.
It is a further object of the present invention to provide an improved picking tool that is adapted for grasping a variety of items comfortably.
It is yet another object of the present invention to provide an improved picking tool that is easy to use and light weight.
The subject matter of the present invention is particularly pointed out and distinctly claimed in the concluding portion of this specification. However, both the organization and method of operation, together with further advantages and objects thereof, may best be understood by reference to the following description taken in connection with accompanying drawings wherein like reference characters refer to like elements.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 top view of a picking tool according to the invention;
FIG. 2 is a side view of the picking tool of FIG. 1 , with the trigger in the actuated position;
FIG. 3 is a perspective view of the head portion of the picking tool, with one arm removed;
FIG. 4 is an alternate perspective view of the head portion of the picking tool, with one arm removed, with the end effector switched to the alternate configuration;
FIG. 5 is a perspective view of the handle and actuator trigger portion of the picking tool, with the trigger in the position when not actuated;
FIG. 6 is a view of the head portion 16 in a disassembled state;
FIG. 7 is a sectional view of the head portion taken along line 7 - 7 of FIG. 6 ;
FIG. 8 is a perspective view of a link member;
FIG. 9 is a perspective view of arm 18 ;
FIG. 10 is an end view of arm 18 ;
FIG. 11 is a bottom view of arm 18 ;
FIG. 12 is a top view of the picking tool in the open position;
FIG. 13A is a perspective view of a stick member;
FIG. 13 b is a cross sectional view of the shape of the portion 92 of the stick;
FIG. 14 is a perspective view of an end effector;
FIG. 15 is a side view of an end effector;
FIG. 16 is a perspective view of a lock/turning mechanism;
FIG. 17 is a top end view of the lock/turning mechanism of FIG. 16 ;
FIG. 18 is a bottom end view of the lock/turning mechanism of FIG. 16 ;
FIG. 19 is a sectional view of the lock/turning mechanism of FIG. 16 ;
FIG. 20 is a perspective view of the trigger; and
FIG. 21 is a perspective view of a cable guide way employed in the handle member.
DETAILED DESCRIPTION
The system according to a preferred embodiment of the present invention comprises a picking tool with a trigger style actuator to cause 2 arm members to pivot toward each other, to bring corresponding head members together for closing on an item to enable gripping and picking the item.
Referring to FIG. 1 and FIG. 2 , which are top and side views of the picking tool 10 with the tool in the closed position, the tool includes a handle portion 12 , suitably including a TPR rubber covering, for comfort to the user's hand. The handle portion 12 is connected to an elongate extension member 14 , having at the end distal from the handle portion, an actuation head portion 16 . The head portion pivotally mounts arms 18 and 20 , said arms carrying end effectors 22 and 24 thereon. The head portion includes fixed arm members 36 and 38 , having pin member 26 and 28 at the distal ends thereof, the pin member 26 and 28 being engaged with an elongate slot portion 30 , 32 of the respective arms 18 and 20 . End portions of arms 18 and 20 are pivotally held to the head portion 16 by pin 34 through respective holes (not visible in FIGS. 1 and 2 ) in the arms 18 and 20 .
In FIG. 2 , it may be observed that the picking tool handle supports a trigger member 40 which is pivotally carried by the handle portion 12 , pivoting about pivot position 42 . A cable 44 is engaged by the trigger member, the opposite end of the cable being attached to a portion of the head 16 as discussed hereinbelow. Actuation of the trigger to the position show in FIG. 2 , pulls the cable which causes the two arms 18 , 20 and end effectors 22 , 24 , to be in the position shown in FIG. 1 . Cable 44 extends through the elongate extension member 14 , which suitably is in the form of a hollow rod so as to have a space therein to receive the cable along the extent thereof.
Referring now to FIGS. 3 and 4 , perspective views of the head end of the picking tool, with arm portion 20 removed for illustration purposes, it may be observed that the end effector 22 (and also end effector 24 ) may assume 2 different orientations. In FIG. 3 , the end effector is positioned such that a flat face 46 is oriented toward the center, such that on actuation of the trigger, the two flat faces 46 , 48 of the end effectors 22 , 24 will meet, as in FIG. 1 , to provide a flat gripping surface to the end effectors. In FIG. 4 , the end effector 22 is rotated 180 degrees on the axis 50 - 50 , so that the cup-like face 48 is oriented toward the center, so as to provide a cup like grasping shape to the end effectors.
Referring to FIG. 5 , a perspective view of the handle and actuator trigger portion of the picking tool, with the trigger in the position when not actuated, the trigger 40 moves forwardly of the handle portion when in the un-actuated position. The trigger is spring biased by its engagement with the cable, as discussed below, to be in the un-actuated position in absence of being pulled toward the handle by a user.
Referring now to FIG. 6 , a view of the head portion 16 in a disassembled state, extension member 14 (illustrated in phantom) is received into a corresponding shaped receiving portion 52 so as to fit the extension member 14 and head 16 together. The body of head 16 defines a tubular portion that carries arms 36 and 38 , which project forwardly in an arcuate shape, having parallel tangs 54 with holes 56 therein, so as to define the pivot positions 26 and 28 . A through bore 58 is formed in the end of head 16 at the region where extension member 14 is engaged.
FIG. 7 is a sectional view of the head portion 16 , taken along line 7 - 7 of FIG. 6 , wherein it may be observed that the interior of the tube-shaped portion of head 16 includes a space defined therein with a seat portion 60 , and a narrower diameter portion as it approaches the extension member 14 whereby a spring 62 may be received in the narrower portion and, when in its extended configuration, will extend into the wider portion 63 , to provide spring bias to the picking tool to an open position in conjunction with the link member of FIG. 8 .
Referring now to FIG. 8 , a perspective view of a link member 64 , the link member comprises a narrow central extension 66 having a cable engaging portion 68 at the end thereof, for receiving and engaging cable 44 . A tubular portion 70 is provided and of a size so as to slidingly fit within the interior 63 of head 16 where spring 62 is positioned. The spring engages with face 72 of the link member, to bias it towards and extended configuration. A wider head portion 65 has bores 67 therethrough, with parallel tang portions 69 defining an opening therebetween.
When the picking tool is assembled, member 64 fits into opening 63 of head 16 , and portion 66 extends on through opening 58 so as to be accessible to engage cable 44 at portion 68 . Referring to FIG. 3 , which illustrates the picking tool with link portion 64 inserted into head 16 , it may be observed that the link is adapted for translation inwardly and outwardly of the head portion, as noted by arrow 74 .
FIGS. 9 , 10 and 11 are a perspective, end and bottom view of arm 18 . The arm is substantially arcuate, having a cylindrical end post 76 positioned at the distal end of the arm. Elongate slot portion 30 is defined in a portion of the arm closer to the arm end having a bore 78 defined in a tang portion 80 of the arm 18 .
Referring to FIG. 10 , an end view of the arm 18 , end post 76 includes a square central bore 82 extending at least partially into the extent thereof. The exterior of the post is substantially cylindrical in shape, but carries a protrusion 84 on one edge at the distal end of the post, extending a short distance toward the base of the post.
When assembled, two such arm portions, arm 18 and arm 20 (which is substantially identical in configuration to arm 18 ), are positioned, with one arm flipped around such that the corresponding tang portions 80 of the two arms face each other and are positioned in the opening between tang portions 69 of the link member, and a pivot pin 34 is mounted through bores 67 and 78 . The pin is suitably configured to be fixed into place once mounted, so as to be retained in position while still allowing pivoting movement about the pin.
Further, the arm portions are positioned such that slot portions 30 are positioned between respective tangs 54 of the corresponding arms 36 and 38 of head portion 16 , whereupon a pin member 26 ( 28 ) is passed through the openings 56 of the tangs 54 so as to provide a sliding engagement with the arm 36 and slot 30 ( 32 ) of arm 18 ( 20 ).
Now, the cable 44 is engaged at portion 68 of the link member 64 , and is correspondingly engaged with the trigger member 40 , whereupon the interaction of the spring and link member and head portion, will spring bias the link portion outwardly of the head and the arms 18 and 20 will move outwardly in the direction of arrows 21 ( FIG. 1 ). FIG. 12 , a top view, illustrates the picking tool in the open configuration, when the trigger member is in the position of FIG. 5 , not pulled.
FIGS. 13A-19 illustrate the end effectors and the construction and operation thereof.
FIG. 13A is a perspective view of a stick member 86 , which has one end 88 in a square cross section configuration, sized to be received within the square central bore 82 of end post 76 . A seat portion 90 on stick 86 is provided of sufficient diameter to act as a stop to define the extent to which the end 88 of stick 86 will extend into bore 82 . Alternatively, this extent may be defined by the length of portion 88 and the depth of bore 82 . Above seat portion 90 , two flat notch portions 92 are defined on opposite faces of the stick, comprising a first portion 92 A and a second portion 92 B at an angle thereto. FIG. 13B illustrates the cross sectional configuration of the notch portions 92 A and 92 B. Above the notch portions on the stick is a slightly narrower region 94 , ending in a top cap 96 .
Referring to FIG. 14 , a perspective view of an end effector 22 , it may be noted that the end effector includes a bore 99 substantially centrally of the portion defining the flat face 46 thereof. The shape and diameter of the bore corresponds to that shape and diameter of the portion 96 of stick 86 . The length of region 98 may be substantially the same as the length 100 of the end effector as in FIG. 15 , a side view thereof.
FIGS. 16-19 are views of a turning/lock member. FIG. 16 is a perspective view, wherein the lock/turning member 102 is of a hollow cylinder configuration and has indentations on the exterior thereof for gripping by a user. The view in FIG. 16 may be considered as from the “bottom” of the lock member, and left and right slots 104 , 106 are defined 180 degrees apart in the interior of the lock member. The slots 104 , 106 extended a substantial length of the lock member, and near the opposite end of the lock member (but not all the way to the end) a ridge portion 110 is defined radially adjacent the slot 104 and an adjacent divot 112 is positioned radially adjacent the ridge portion 110 . A corresponding ridge and divot are defined on the opposite side, adjacent slot 106 . Inwardly extending tab portions 114 (and 116 ) are defined adjacent slot 104 (and 106 ), positioned on the other side of the slot 104 from ridge and divot 110 and 112 .
The components of FIGS. 13-19 interact, together with end post 76 , to provide multiple configurations to the end effector, which may be desired depending on the particular use for which the picking tool is being employed.
In assembling to tool, the end 96 of stick 86 is inserted into the lock/turning member in the direction of arrow 118 of FIG. 16 , with the two items being positioned such that portions 114 and 116 of the lock/turner are matched to notch portions 92 . Next, the end effector may be positioned onto the stick to cover portion 94 . The end effector operates to maintain the relation of the lock/turner to the stick.
Next, the square cross section portion 98 of the stick may be placed into the corresponding bore 82 of the respective arms 18 or 20 . The square configuration of the bore 82 and stick, together with the protrusion 84 , the slots 102 , 104 and the tab portions 114 , 116 , operate to define two alternate positions in which the stick may be inserted into the bore 82 , the two positions being 180 degrees out of phase.
Once the stick is so inserted into the bore, the user may rotate the turner 102 clockwise so that the protrusion 84 , which has ridden in either slot 104 or 106 , rides over ridge portion 110 so as to rest in divot 112 , operating as a lock to engage the end effector onto the end of the picking tool so as to not fall off thereof. The user may then operate the picking tool to grasp and pick items as desired, by pulling the trigger member, which will cause the arms 18 and 20 to move together from the configuration of FIG. 12 , toward the configuration of FIG. 1 , to grasp the item between the end effectors.
To change to the other style of end effector, the user grasps and rotates lock/turner member 102 counterclockwise so as to rotate the turner such that portion 84 is moved out of divot 112 , over portion 110 , to be aligned again with slot 104 . Then the end effector (including the stick and lock/turner) may be pulled out of engagement with bore 82 , rotated 180 degrees so as to position the other effector face in position, and then the stick portion is re-inserted to bore 82 . It will be understood that having rotated the end effector configuration 180 degrees, it is now the slot 116 on the opposing side of the lock member, and the corresponding adjacent ridge portion and divot, that will interact with protrusion 84 to lock the end effector in place.
FIG. 20 is a perspective view of the trigger member 40 , wherein a bore 42 ′ is formed therein to interact with a pin or the like to define pivot 42 as discussed in connection with FIG. 5 . A cable engaging portion 120 is defined at the bottom front end of the trigger member, with a slot 122 being defined therein and extending up to the top of the front of the trigger, to receive cable 44 therein. Once cable 44 is positioned behind the engaging portion 120 , the rearward portion 122 ′ (for example) may be suitably filled in or otherwise closed up, to prevent the cable from inadvertently becoming detached from the trigger. This may be accomplished by insertion of a wedge or closing piece or by gluing or fusing the opening 122 ′.
Referring to FIG. 21 , a cable guide way 124 is provided to guide the cable from the trigger/handle portion and position it relative to the extension portion 14 . A bore 126 ( FIG. 5 ) in the handle member corresponds to a bore 126 ′ in the guide way, for securing the guide way with a pin, for example, to the handle. Left and right tang member 128 of the guide way operate to engage the guide way with the handle member 16 .
The various components of the picking tool are suitably made of various plastic materials, although extension member 14 is an aluminum tube in a preferred embodiment. The end effectors are of a rubber type material, to provide a flexible aspect to the cup portions thereof and the flat portions, for better gripping of items being picked. The various pivot pins may suitable be metal rivets, for example. Cable 44 is suitably a steel cable, such as stainless steel.
Accordingly, a picking tool is provided that is easy to use with end effectors that can be changed to different configurations to provide varied picking capabilities.
While a preferred embodiment of the present invention has been shown and described, it will be apparent to those skilled in the art that many changes and modifications may be made without departing from the invention in its broader aspects. The appended claims are therefore intended to cover all such changes and modifications as fall within the true spirit and scope of the invention. | A picking tool employs a changeable end effector having first and second operative portions. A changing member allows selection of the first or the second portions for deployment during picking, such that the picking tool can be changed to different configurations of end effectors for varied uses. The changing member provides a locked position where the end effector is locked onto the picking tool for use and an unlocked position whereby the end effector may be removed and repositioned to present a different portion for operative use. | 8 |
This application is a divisional of U.S. application Ser. No. 498,341, filed June 1, 1983, now U.S. Pat. No. 4,489,029.
SUMMARY OF THE INVENTION
The invention disclosed in this application relates to compositions, based on alkylene-alkyl acrylate copolymers and silanol condensation catalysts, which are useful in the preparation of water-curable, silane modified alkylene-alkyl acrylate copolymers. More particularly, this invention relates to a process of extruding water-curable, silane modified alkylene-alkyl acrylate copolymers and compositions based thereon about wires and cables to provide coverings, such as insulation and jacketing, characterized by improved properties.
BACKGROUND OF THE INVENTION
Silane modified alkylene-alkyl acrylate copolymers described in U.S. Pat. Nos. 4,328,323, granted May 4, 1982 and 4,291,136, granted Sept. 22, 1981, are particularly desirable for use in extrusion applications as these polymers and compositions based thereon can be cured by a simple water treatment, as opposed to the more conventional peroxide cure, to crosslinked products of high crosslinked density. As a result, silane modified alkylene-alkyl acrylate copolymers, as described, and compositions based thereon are especially useful in extrusion applications, being capable of extrusion under a wide latitude of processing conditions.
BRIEF DESCRIPTION OF THE INVENTION
The present invention, in one aspect, relates to compositions, based on alkylene-alkyl acrylate copolymers and silanol condensation catalysts, which are particularly useful in an improved process of extruding water-curable, silane modified alkylene-alkyl acrylate copolymers and compositions based thereon about wires and cables.
In the process aspect of this invention, an alkylene-alkyl acrylate copolymer or composition based thereon is admixed with a silanol condensation catalyst, the resultant composition soaked with an organo titanate catalyst and the soaked composition admixed with a polysiloxane or monomeric silane with the result that the alkylene-alkyl acrylate copolymer reacts with the polysiloxane or monomeric silane to form a product, containing a water-curable, silane modified alkylene-alkyl acrylate copolymer, which is then extruded about a wire or cable.
The process, as described, results in coverings, such as insulation and jacketing, about wires and cables which are characterized by a number of improved properties, as shown by the data of the examples of this application.
BRIEF DESCRIPTION OF THE DRAWING
The drawing is a schematic view of the preferred system, including the extrusion apparatus for carrying out the process of this invention using a 21/2 inch extruder.
DETAILED DESCRIPTION OF THE INVENTION
As previously stated, the present invention, in one aspect, relates to compositions based on an alkylene-alkyl acrylate copolymer and a silanol condensation catalyst.
The alkylene-alkyl acrylate copolymers are known copolymers, normally solid at ambient temperatures, produced by reacting an alkene with an alkyl acrylate.
Suitable alkenes include ethylene, propylene, butene-1, isobutylene, pentene-1, 2-methylbutene-1, 3-methylbutene-1, hexene-1, heptene-1, octene-1, vinyl chloride, styrene and the like and mixtures thereof.
The alkylene moiety of the alkylene-alkyl acrylate copolymer generally contains from 2 to 18 carbon atoms inclusive, preferably 2 to 3 carbon atoms inclusive.
Suitable alkyl acrylate monomers which are copolymerized with the alkenes fall within the scope of the following formula: ##STR1## wherein R 4 is hydrogen or methyl and R 5 is alkyl having one to 8 carbon atoms inclusive. Illustrative compounds encompassed by this formula are: methyl acrylate, ethyl acrylate, t-butyl acrylate, methyl methacrylate, n-butyl acrylate, n-butyl methacrylate, 2-ethylhexyl acrylate and the like and mixtures thereof.
Alkylene-alkyl acrylate copolymers generally have a density (ASTM D 1505, with conditioning as in ASTM D 147-72) of about 0.92 to about 0.94 and a melt index (ASTM D 1238 of 44 psi tested pressure) of about 0.5 to about 500 decigrams per minute.
For purposes of the present invention, the preferred copolymer, generally a copolymer of ethylene-ethyl acrylate, has about one to about 50 percent by weight combined alkyl acrylate, preferably has about 2 to about 40 percent by weight combined alkyl acrylate.
Silanol condensation catalysts, that is compounds which accelerate the crosslinking of the water-curable, silane modified alkylene-alkyl acrylate copolymers are also well known compounds. Among such compounds can be noted the metal carboxylates such as dibutyltin dilaurate, stannous acetate, stannous octoate, lead naphthenate, zinc octoate, iron-2-ethyl hexoate and the like, organic bases such as ethylamine, hexylamine, dibutylamine, piperidine and the like, and acids such as mineral acids and fatty acids and the like.
For purposes of this invention, dibutyltin dilaurate is preferred.
Exemplary of organo titanate compounds which catalyze the reaction between the polysiloxane or monomeric silane and the alkylene-alkyl acrylate copolymer, and are used to soak the alKylene-alkyl acrylate compositions, as previously described, are those falling within the scope of Formula II.
ti(OR.sup.2).sub.4 Formula II
wherein each R 2 , which can be the same or different, is hydrogen or a hydrocarbon radical having one to 18 carbon atoms inclusive, preferably one to 14 carbon atoms inclusive. By definition of a titanate, one R 2 must be a hydrocarbon radical.
Exemplary of suitable hydrocarbon radicals are alkyl radicals such as methyl, ethyl, n-propyl, isopropyl, butyl, octyl, lauryl, myristyl, stearyl and the like, cycloaliphatic radicals such as cyclopentyl, cyclohexyl and the like, aryl radicals such as phenyl, methylphenyl, chlorophenyl and the like, alkaryl radicals such as benzyl and the like.
Particularly desirable titanates falling within the scope of Formula II are those wherein each R 2 is alkyl having one to 18 carbon atoms, inclusive, preferably one to 14 carbon atoms inclusive, exemplified by tetrabutyl titanate, tetraisopropyl titanate and the like.
Other suitable organo titanates are the organo titanium chelates such as tetraoctylene glycol titanium, triethanol amine titanate, titanium acetyl acetonate, titanium lactate and the like.
Polysiloxanes, which are suitable for purposes of this invention, contain repeating units of the formula: ##STR2## wherein R is a hydrocarbon radical or oxy substituted hydrocarbon radical, each V, which can be the same or different, is hydrogen, a hydrocarbon radical or a hydrolyzable group; Z is a hydrolyzable group; n is an integer having a value of one to 18 inclusive and x is an integer having a value of at least 2, generally 2 to 1,000 inclusive, preferably 5 to 25 inclusive.
Illustrative of suitable hydrocarbon radicals for R are alkylene radicals having one to 18 carbon atoms inclusive, preferably one to 6 carbon atoms inclusive, such as methylene, ethylene, propylene, butylene, hexylene and the like; alkoxy radicals having one to 18 carbon atoms inclusive, preferably one to 6 carbon atoms inclusive such as methyloxymethyl, methyloxypropyl, ethyloxyethyl, ethyloxypropyl, propyloxypropyl, propyloxybutyl, propyloxyhexyl and the like.
As stated, each V can be hydrogen, a hydrocarbon radical or a hydrolyzable group. Illustrative of suitable radicals are alkyl radicals having one to 18 carbon atoms inclusive, preferably one to 6 carbon atoms inclusive such as methyl, ethyl, n-propyl, isopropyl, n-butyl, n-hexyl and the like; alkoxy radicals having one to 18 carbon atoms inclusive, preferably one to 6 carbon atoms inclusive, such as methoxy, ethoxy, propoxy, hexoxy, dodecyloxy, methoxyethoxy and the like; aryl radicals having 6 to 8 carbon atoms inclusive such as phenyl, methylphenyl, ethylphenyl and the like; cycloaliphatic radicals having 5 to 8 carbon atoms inclusive such as cyclopentyl, cyclohexyl, cyclohexyloxy and the like.
Z, as previously stated, is a hydrolyzable group among which can be noted alkoxy radicals as previously described for V and R; oxy aryl radicals such as oxyphenyl and the like; halogens such as chlorine and the like.
Polysiloxanes containing repeating units falling within the scope of Formula III can be prepared as described in U.S. Pat. No. 4,328,323 by condensing and polymerizing a silane falling within the scope of Formula IV. ##STR3## wherein R 1 is a hydrocarbon radical, as for example, an alkyl radical having one to 18 carbon atoms inclusive, preferably one to four carbon atoms inclusive such as methyl, ethyl, n-propyl, isopropyl, n-butyl and the like; alkylene radicals having two to 18 carbon atoms inclusive, preferably two to 4 carbon atoms inclusive such as ethylene, propylene and the like; aryl radicals having 6 to 10 carbon atoms inclusive such as phenyl, benzyl and the like. Other variables are as previously defined.
Exemplary of suitable silanes falling within the scope of Formula IV are the following: ##STR4##
Preferred polysiloxanes have a viscosity of about 0.5 poise to about 150 poise, preferably about one to about 20 poise as determined by a Gardner-Holdt bubble viscometer at a temperature of 25° C.
As previously stated, monomeric silanes, for instance, silanes falling within the scope of Formula IV can be used in lieu of the polysiloxanes.
Referring now to the accompanying drawing, a pelletized mixture of alkylene-alkyl acrylate copolymer and silanol condensation catalyst is fed from resin feed stock bin (3) to a dryer system (5) by means of a vacuum tube (7) and vacuum loader (9), through conveyor line (1).
The amount of silanol condensation catalyst admixed with the alkylene-alkyl acrylate copolymer is sufficient to accelerate the water-cure of the silane modified alkylene-alkyl acrylate copolymer. As a rule, this amount is about 0.001 to about 0.5, preferably about 0.005 to about 0.1 percent by weight based on the weight of the copolymer.
Admixing of the silanol condensation catalyst, the alkylene-alkyl acrylate copolymer and desired additives is carried out in a compounding system such as a twin screw extruder wherein the ingredients are melted and mixed. The mixture is subsequently pelletized by methods known in the art.
The pelletized mixture of alkylene-alkyl acrylate copolymer and silanol condensation catalyst is dried in dryer system (5) to insure that the water content thereof is below about 500 ppm, preferably below about 300 ppm.
From dryer system (5), the pelletized mixture is fed through conveyor line (11) and into receiver (13) of vertical blender (15) by means of vacuum loader (17).
Vertical blender (15) contains an open helix mixer (19) which aids in dispersing the organo titanate throughout the pelletized mixture. The organo titanate is pumped into the top of vertical blender(15) from reservoir (23). Helix mixer (19), driven by motor (25) through gear reducing driving belt (27) and uplifting agitator (not shown) of vertical blender (15) thoroughly mix the pellets and the organo titanate.
Residence time of the pelletized mixture in vertical blender (15) is sufficient to soak the organo titanate into the pellets as evidenced by absence, essentially, of liquid (wetness) on the surface of the pellets.
The resultant soaked pellets drop directly into the hopper (2) of an extruder assembly and are contacted therein with polysiloxane or monomeric silane pumped from reservoir (21).
The amount of silane "reactant" fed into hopper (2) is generally about 0.05 to about 10, preferably about 0.3 to about 5 percent by weight, based on the weight of the copolymer.
The amount of organo titanate used to soak the pelletized mixture, previously defined, is sufficient to inhibit the adverse effects of moisture, present in the composition or generated therein during processing. Generally, the weight ratio of organo titanate to polysiloxane or monomeric silane is at least about 0.1 to 1, generally about 0.5 to about 10 to one, preferably about 1 to about 5 to one, and most preferably about 1 to about 3 to 1.
The total reaction mixture containing the alkylene-alkyl acrylate copolymer, the silanol condensation catalyst, organo titanate and silane "reactant" passes into the extruder wherein the reaction mixture is mixed, reacted and extruded out of the extruder onto a wire.
In the extruder assembly shown, designed by Geoffrey Brown, the reaction mixture passes through a series of zones of the extruder assembly, being in sequence, a feed zone, a transition zone, a metering zone, a reaction zone defined by a static mixer and is extruded from the extrusion die onto a wire.
Feed zone function is to convey the pellets forward to maintain a constant supply of material to the next section. Typical temperatures are about 100° C. to about 180° C. preferably about 140° C. to about 160° C. for this zone.
Transition zone function is to compress the pellets into a shallower channel. The tightly packed pellets are deformed, sheared, and for the most part, melted in this section due to a combination of mechanical energy input and thermal energy from the hot barrel. Typical temperatures are about 130° C. to about 200° C., preferably about 150° C. to about 175° C. for this zone.
Metering zone function is to complete the melting process, to provide a steady and metered output rate, and to pressurize the melt to force it through the die. Typical temperatures are about 130° C. to about 220° C., preferably about 160° C. to about 190° C. for this zone.
Reaction zone function is to allow sufficient time at the metering zone temperature to insure that complete reaction or grafting has occurred.
To the silane modified copolymers can be added various additives in amounts well known in the art. This is conveniently accomplished by formulating compositions containing additives, alkylene-alkyl acrylate copolymers and silanol condensation catalysts and processing the compositions as described.
Exemplary of such additives are those disclosed in U.S. Pat. No. 4,328,323 and U.S. Pat. No. 4,353,997, among which can be noted halogenated flame retardant additives, antimony oxide, ground calcium carbonate, clay and the like.
Also, the compositions of this invention can contain hydrous and/or water-releasing fillers.
These fillers, which are generally used in amounts of about 1 to about 250 percent by weight based on the total weight of the copolymer can be exemplified by the following: hydrous fillers such as hydrous clay, non-conductive carbon blacks, conductive carbon blacks such as Ketjen Black EC, zinc borate, talc, and the like; water-releasing fillers such as aluminum trihydrate, magnesium hydroxide, calcium hydroxide, barium hydroxide, zinc hydroxide, precipitated calcium carbonate, basic magnesium carbonate and the like.
Particularly desirable compositions contain, as additives, aluminum trihydrate or magnesium hydroxide and a scorch inhibiting compound.
Among suitable scorch inhibiting compounds can be noted alcohols, particularly alcohols having a boiling point higher than 100° C. such as octanol, decanol, dodecanol, myristyl alcohol, stearyl alcohol and the like. Also suitable are esters of such alcohols such as dioctyl phthalate, dioctyl adipate, dioctyl succinate and the like.
Plasticizers for vinyl resins are also suitable as scorch inhibiting compounds. These plasticizers include cyclic plasticizers such as phthalate plasticizers among which can be noted butyl decyl phthalate, butyl octyl phthalate, dibutyl phthalate, dicyclohexyl phthalate, dicyclooctyl phthalate and the like. Phosphate esters such as cresyl diphenyl phosphate, 2-ethylhexyl diphenyl phosphate, triphenyl phosphate and the like; trimellitic acid esters such as the n-octyl and n-decyl ester of trimellitic acid and the like; acyclic plasticizers such as the di(2-(2-butoxyethoxy)ethyl) ester of adipic acid, the di(2-ethylhexyl) ester of adipic acid, the diisodecyl ester of adipic acid and the like; oleic acid esters such as butyl oleate, glyceryl trioleate, methyloleate and the like as further disclosed in a publication entitled Vinyl Plasticizers, Report No. 62, April 1970 Stanford Research Institute, Menlo Park, Calif.
Suitable scorch inhibiting compounds, that is compounds which reduce scorch and do not undergo a crosslinking reaction with the components of the composition to which they are added are used in amounts sufficient to reduce scorch, generally in amounts of about 0.5 to about 20 percent by weight, preferably about 2 to about 10 percent by weight based on the weight of the total composition.
The curing or crosslinking of the silane modified alkylenealkyl acrylate copolymer and compositions based thereon is effected by exposing the copolymer to moisture. The moisture present in the atmosphere is usually sufficient to permit curing to occur over a period of 48 hours.
The rate of curing, in a matter of 30 minutes, can be accelerated by exposure to an artificially humidified atmosphere or immersion in water and heating to elevated temperatures or by exposure to steam.
Generally, curing is effected at temperatures on the order of about 23° C. to about 180° C., preferably about 70° C. to about 100° C.
In Example 1 which follows, the composition was extruded onto a #14 AWG copper wire using a system as shown in the accompanying drawing wherein the extruder had:
1. a 30 to 1 length to diameter grooved barrel (grooved at Feed Zone)
2. a 20 to 1 polyethylene compression screw, having a 2.5 inch diameter, which was tapered and cored, allowing for control of temperature by feeding water into the core
3. four sets of radial mixing pins equally spaced along the metering zone
4. band or cylindrically cast heaters, providing independent temperature control of each zone.
A run, Example 1, was carried out using the system shown in the accompanying drawing wherein the materials used were a pelletized mixture of dibutyltin dilaurate and Formulation I; tetraisopropyl titanate and polysiloxane.
______________________________________Formulation I______________________________________ Percent by WeightCopolymer of Ethylene- 56.15Ethyl AcrylateContaining 15% by Weight CombinedEthyl Acrylate-Melt Index 1.6Talc Coated with Zinc Stearate 21.68Antimony Oxide 2.50Calcium Carbonate 2.50Ethylene (Bis-tetrabromophthalimide) 16.29(Flame Retardant Additive)Polymerized 1,2-dihydro- 0.582,3,4,-trimethylQuinoline (Antioxidant) 0.58Vinyl-tris(2-methoxy-ethoxy) Silane 0.30 Percent by Weight Based On Formulation IDibutyltin Dilaurate 0.04Tetraisopropyl Titanate 0.79Polysiloxane 0.80Weight Ratio of Organo ˜1Titanate to Polysiloxane______________________________________
The polysiloxane used was prepared according to Example 3 of U.S. Pat. No. 4,328,323 with the exception that 235 grams (1.03 moles) of ethyl laurate were substituted for ethyl benzoate.
The polysiloxane can be depicted, ideally, as follows:
______________________________________ ##STR5##Moisture content of pelletized mixture 149 ppmafter dryingSoak time of pelletized mixture of 10 minutesdibutyltin dilaurate and Formulation Iwith organo titanateScrew speed 94 rpmScrew coolingwater fed into core at a temperature of53° C. and rate of 75 gallons per hour -temperature at removal - 68° C.Rate of extrusion 199 lbs. per hourWire speed 500 feed per minute______________________________________Temperature and PressureProfile Feed Transition Metering Reaction Zone Zone Zone Zone Die______________________________________Temperature of 154 150 154-171 160 204Heaters, SetTemperature,(°C.)Material Temper- 153 159 166 163-175 191ature, (°C.)Pressure, -- 3200-4600 5000- 5300- 5200(psi) 5500 5400______________________________________
For purposes of conducting the Rheometer test, described below, insulation was stripped from the wire, placed in a water bath, which was at a temperature of 75° C., for 18 hours and then pressed into 0.150 inch thick plaques under the fo-lowing conditions:
______________________________________Pressure 3 TonsTemperature 125° C.Time of Cycle 5 minutes heating 5 minutes cooling______________________________________Tests and TestResults______________________________________Rheometer-ASTMD-2084-75 reported in inch-lbs and indicates the level of cureNumber of Voids cross-section of uncured insulation was examined under 40X magnification and voids counted per gridThickness of Insulation 37 milsSpark faults test described in Underwriters Laboratories Standard UL-44 "Rubber Insulated Wires And Cables" as revised January 1, 1982, paragraphs 70-72. This test determines if there are any minute holes in the uncured insulation which would allow the current to short to ground. UL specifies that there be no faults in a completed cable, but industry standards allow for a maximum of one per 3000 feet of cable as made in a commercial run. The UL requirement is then met by cutting out the voids or faults from the cable and splicing the cable ends together.Stability calculated from diameter fluctuations and expressed as ± percent of total output. Normal deviation of extrusion lines is ± 2 percent.______________________________________Test Results______________________________________Rheometer inch-lbs.Number of Voids 15 per gridSpark Faults 0 per 13,500 feet of insulationStability ± 1.8 percent______________________________________
A second run, Control 1, was carried out in essentially the same manner as Example 1, using the same materials, with the exception that the dibutyltin dilaurate, tetraisopropyl titanate and polysiloxane were admixed and introduced into the system as a mixture at the hopper (2).
______________________________________Test Results______________________________________Rheometer 37 inch-lbsNumber of Voids 468 per gridSpark Faults 0 per 16,000 feet of insulationStability ± 9.0 percent______________________________________
In order to further show the advantages of adding the silanol condensation catalyst to the alkylene-alkyl acrylate copolymer, three runs were carried out essentially as described with respect to Example 1, using Formulation I and the same extruder system with the following exceptions:
1. Smooth barrel extruder was used.
2. An Acrison Horizontal Blender was used in lieu of the vertical blender shown in the accompanying drawing.
3. Control 2 was carried out by adding a mixture of organo titanate, polysiloxane and silanol condensation catalyst to Formulation I in the Acrison Horizontal Blender
4. Control 3 was carried out by adding a mixture of organo titanate and polysiloxane to a pelletized mixture of silanol condensation catalyst and Formulation I in the Acrison Horizontal Blender
5. Example 2 was carried out in a manner similar to Example 1 by combining the silanol condensation catalyst with Formulation I, soaking the pelletized mixture with organo titanate in the Acrison Horizontal Blender and adding the polysiloxane to the soaked composition at the extruder throat as in Example 1
______________________________________Percent By Weight Based on Formulation I Example Control Control 2 2 3______________________________________Dibutyltin Dilaurate 0.03 0.05 0.04Tetraisopropyl Titanate 0.41 0.36 0.37Polysiloxane (same as 0.90 1.08 1.12Example 1)Moisture Contentof pelletized mixture 233 ppm -- --of Formulation I -- 171 ppm 190 ppm______________________________________
______________________________________Operating Conditions of Extruder Assembly Example Control Control 2 2 3______________________________________Temperaturesset/actualin °C.Feed Zone 138/-- 137/-- 154/--Transition Zone 149/149 154/156 165/162Metering Zone 179/180 177/180 182/184Reaction Zone 176/183 177/189 182/193Die 204/199 204/199 204/203PressurespsiTransition Zone 1200-2400 400-3000 800-2600Metering Zone 3400-4800 2400-5000 2000-4800Reaction Zone -- -- --Die 5000 4400 5100Screw Speed, rpm 118 116 116Output Rate, lbs/hr 183 200 200Wire Speed, fpm 500 500 500Screw Cooling 75 75 75Amount of Water, gphTemperature of 81 81 79Water in, °C.Temperature of 88 91 93Water out, °C.PropertiesRheometer 40 42 55Voids 5 0 per 40Spark Faults 0 per 14 per 0 per 9000 ft. 13,500 ft 1000 ft.Stability (%) ± 7.6 ± 16.8 ± 15.3Thickness of Insulation 33.5 mils 37.5 mils 37.5 mils(average)______________________________________
If desired mixtures of reactants, catalyst, additives and the like can be used if so desired.
Also, it is to be understood that within the essence of the claimed invention, the operating conditions of the extrusion system such as temperatures, pressures and the like can be varied to accommodate the actual composition being extruded, output of the extruder and the like.
The disclosures of all patents noted are incorporated herein by reference. | The disclosure of this application relates to compositions based on alkylene-alkyl acrylates and silanol condensation catalysts which are useful in the preparation of water-curable, silane modified alkylene-alkyl acrylate copolymers, capable of extrusion about wires and cables. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
The present application is a non-provisional application of U.S. Provisional Application Ser. No. 61/295,864, filed on Jan. 18, 2010. The present application also claims priority to German Application No. 102010004884.4, filed on Jan. 18, 2010. The entire contents of each of these applications are incorporated by reference herein.
BACKGROUND OF THE INVENTION
The present invention refers to a fundus camera for an imaging of the eye fundus. In particular, the invention refers to a fundus camera having compact dimensions, which can be offhand held in the hand.
The basic setup of a fundus camera consists of a multistage optical system, in which a wide-angle lens that is positioned in close proximity to the eye creates an intermediate image, which intermediate image is mapped onto a film or a CCD array by further optical components. Here, the necessity of bringing illumination light into the eye is a problem that always occurs, when the eye fundus is observed.
Usually the illumination light will enter the eye through the pupil. However, here the problem is met that there are reflexes at the refracting media in the eye, which reflexes interfere with the observation. U.S. Pat. No. 3,944,341 therefore describes a fundus camera, in which, though the light enters through the pupil, a reflection at the lens of the eye is avoided by choosing a ring-shaped illumination by means of optical fibres such that the edge region of the pupil is used for the illumination. In the document two elaborately designed light fibre rings are used for the illumination. However, as this kind of illumination is elaborate, often the front lens that is positioned close to the eye is also used for introducing the illumination light, as it is for example described in U.S. Pat. No. 3,936,844. Such a design, however, again results in a complex optical design, because the illumination light path and the imaging light path are close to each other. Thereby, the eye fundus observation device and camera become very bulky.
Due to the above described problems when using a trans-pupillary illumination, it was suggested in the prior art such as in U.S. Pat. No. 3,954,329 to illuminate the fundus through the sclera. However, this kind of illumination is rather unusual up to nowadays, though document U.S. Pat. No. 3,954,329 was already published in 1976. This might be related to the fact that for a trans-illumination of the sclera the luminous intensity must be high and out of this reason it is not possible to use a light fibre ring. Hence, in devices of the prior art, in which a trans-scleral illumination is used, usually the light is punctually radiated through the sclera by means of a fibre bundle (see for example U.S. Pat. No. 3,943,329). In doing so, it is necessary to radiate through the sclera at more than one position in order to homogenously illuminate the eye fundus. The necessary installation of more than two fibre bundles that results makes the fundus camera bulky.
In view of the above described problems it is an object of the present invention to provide a fundus camera that has a compact design, so that it can be held freely with one hand.
BRIEF SUMMARY OF THE INVENTION
The object is achieved by a hand camera according to claim 1 . Further improvements of the invention are described in the dependent claims.
By the invention it becomes possible to build a mobile fundus camera having a large angular range of approximately 100° or more. The mobility of the camera, which can be operated with one hand, saves time and costs, in particular when patients have to be examined, who are treated in hospitals outside of the ophthalmological departments. Such a mobile camera, however, has a remarkable advantage also for premature infants: premature infants are difficult to examine, because they can only be transported cost-intensively and with an increased risk due to the incubator. Thus, a re-location of a premature infant to an ophthalmological department, where a stationary fundus camera can be used, turns out to be pretty laboriously. This problem can be solved by the camera according to the invention.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
In the following, preferred embodiments of the invention are described by making reference to the drawings.
FIG. 1 shows a hand camera according to the invention, in which the wide-angle optics has no direct contact to the eye during the recordings, and
FIG. 2 is a hand camera according to the invention, in which the wide-angle optics touches the cornea during the recordings.
DETAILED DESCRIPTION OF THE INVENTION
The camera according to the invention comprises a tube 3 c having a wide-angle lens 2 attached to the end 3 e facing the eye to be examined. A telephoto-lens 5 and a camera 4 are attached at the end 3 d of the tube facing away from the eye to be examined. The telephoto-lens 5 and the camera 4 are surrounded by a housing 3 a , 3 b , which is connected in a light-tight way with the tube 3 c . As can be seen in FIG. 1 , the optics that is used is very simple. Basically the inner space of the tube 3 c is empty. The virtual image that is generated by the wide-angle lens 2 is projected by the telephoto-lens 5 onto a two-dimensional optical sensor such as a CCD (charge coupled device) sensor or an APS sensor (active pixel sensor or CMOS sensor) or else onto a photographic film.
The camera may be a compact digital camera, which is pretty similar to a digital camera that is offered on the market for private consumers. The same applies to the telephoto-lens 5 .
In order to change the focus either a commercially available zoom lens can be used or else a camera housing 3 a , 3 b , as it is represented in FIG. 1 , is used. FIG. 1 shows that the camera may be connected to an upper housing part 3 b , which covers a lower camera housing part 3 a , which is connected to the tube 3 c , like a hood. Here, the lower camera housing part 3 a has the shape of a cylindrical short pipe that is open to the top. When the upper camera housing part 3 b is moved with respect to the lower camera housing part 3 a in a direction of the longitudinal axis of the tube 3 c , then as a result the distance between the telephoto-lens 5 and the wide-angle lens 2 can be changed and thereby the focus can be changed. It should be noted that an operator of the camera can look through a view finder or onto a monitor that is attached to the backside of the camera in a similar way to commercially available cameras, wherein neither a view finder nor a monitor are shown in FIG. 1 out of simplicity reasons.
In the present invention the eye fundus is illuminated trans-sclerically. For this purpose a cylindrical ring attachment 1 out of a trans-luminescent material is attached to the end 3 e of the tube 3 c that is facing the eye. This ring attachment, which serves as a light supplying device, is put onto the eye concentrically to the cornea close to the limbus, so that the attachment rests on the eye on the sclera outside of the pupil. Light can be supplied to the ring attachment 1 from a light source 6 . This may be effected for example by means of optical fibres that are coupled to the sidewall of the ring attachment 1 . For example, a short pipe out of the trans-luminescent material of the ring attachment 1 may protrude from the sidewall of the ring attachment 1 . Then an appropriate coupling device for attaching or screwing a cable that contains the light-conducting fibres is affixed on this short pipe.
As the eye has a curvature and as the ring attachment 1 rests on the eye with its face side on the eye, it is advantageous to have a surface area of the face side, which does not form a right angle with the longitudinal axis of the tube 3 c . For example, the outer edge of the ring may further protrude towards the eye than the inner edge. Ideally, the face surface of the ring attachment additionally has a curvature, which curvature is adapted to the curvature of an average eye.
For the light guidance the ring attachment utilizes a total reflection of the light at the interface between the ring material and the surrounding air. Thus, the light is shone uniformly through the ring attachment and ideally is shone annularly through the sclera.
The ring attachment 1 may be made from a trans-luminescent plastic material or from glass. By using such a ring attachment, which is made from a homogenous material, a higher luminous intensity is obtained compared to a light fibre ring. Among other things this is due to the fact that the light fibres have a total area that is much smaller than the total area of the ring attachment. While light-guiding fibres usually have a diameter of a few 100 μm, the wall thickness of the ring attachment may be a few mm. Furthermore, by the selection of a particular ring material losses in the light conduction can be minimized.
Compared to the use of light-guiding fibres there is still a further advantage when using such a ring attachment:
Light-guiding fibres are known to heat up very much due to the heat conduction of the material. This may lead to a damage of the cells of the connective tissue in the eye, onto which the light-guiding fibres of the prior art are put when the temperature exceeds 42° C. In the invention such a heating-up is avoided already due to the larger contact surface at the eye. Moreover, by a selective choice of the material, a too excessive heating-up of the face surfaces of the ring attachment that are resting on the eye can be avoided. For example, borosilicate glass 3.3 may be used as ring material, which material blocks short-wave and long-wave portions of the radiation. In order to avoid damages, it is in any case advantageous to choose a diameter of the ring attachment 1 such that the ring attachment 1 rests on a position of the sclera that contains as few blood vessels as possible, when the pipe 3 c is centrical to the pupil. For example, the diameter of the ring attachment might be chosen such that the distance between the position at which the ring attachment rests on the sclera and the limbus is approximately 2 mm.
By the fundus camera according to the invention a mobile hand camera is provided. In particular, such a camera might be held by the operator in his hand during the examination without the need of having to use a camera tripod. Ideally, the use of the camera is not much more complicated than the use of an ordinary digital camera. A red cast of the pictures that usually appears in a trans-scleral illumination can be computationally eliminated by the camera software after a digitalization. Thereby, complicated optics or various colour filters in the illumination light path in order to correct the colour are avoided.
The trans-scleral illumination has the decisive advantage that there are no problems with reflections at the lens of the eye. Furthermore, it is also a decisive advantage that examinations are possible even for small pupil diameters or pathological changes of the lens that make a trans-pupillar illumination impossible. For example, the formation of tumors may make impossible an illumination through the edge region of the pupil. As was already mentioned in the beginning, the camera is particularly suitable for an examination of premature infants. In order to make this possible, simply a ring attachment 1 having a smaller diameter and a steeper radius than the diameter and radius that are provided for adults have to be selected. “Steeper radius” here means the following: due to the larger curvature of the small eye of the premature infant the face surface of the ring attachment is formed such that the outer edge of the ring protrudes towards the eye to a larger extent than in the case of the ring attachment for adults.
Finally, the trans-scleral illumination makes it possible to illuminate the whole fundus, which is not possible in that way for a trans-pupillar illumination due to the limited diameter of the pupil. As a result, for a corresponding selection of the wide-angle lens 2 field viewing angles up to 165° are possible. In conjunction with FIG. 1 a ring attachment 1 was described that completely surrounds the pupil. The reason for such a complete surrounding of the pupil is a supply of the illumination light that is as uniform as possible. Of course the illumination light can also be trans-illuminated through the sclera at several positions around the pupil that are separated from each other. For example, the face surface of the ring attachment that is put onto the eye, may have recesses. In an extreme case these recesses may even take up most of the wall surface of the ring attachment. Thereby, the ring attachment 1 can rest on the sclera e.g. at six, five, four, three or even only two positions. Of course, the positions at which the ring attachment 1 touches the sclera preferably should have the same distance to each other in a circumferential direction around the pupil.
Of course, it is also possible to use a lens system or an optics having further elements instead of a wide-angle lens 2 . However, the simpler such a wide-angle optics 2 and the fewer components it has, the smaller is the weight of the hand camera. The term “wide-angle optics” here shall comprise also optics that consist only of a singular wide-angle lens.
The wide-angle optics 2 that is arranged at the end 3 e of the tube 3 c that is facing the eye, may be arranged with respect to the face surface of the ring attachment 1 that shall be put onto the eye in such a way, that the wide-angle optics 2 is put onto the cornea of the eye simultaneously with the ring attachment hitting the sclera (indirect ophthalmoscopy, see FIG. 2 ). However, the wide-angle optics can also be arranged in the tube 3 c such that it has a certain distance to the end 3 e of the tube 3 c that is facing the eye (see FIG. 1 ). In an ideal case the wide-angle optics 2 can be moved along the longitudinal axis of the tube 3 c.
In a further embodiment of the invention there is no ring attachment 1 and the illumination light is supplied via a rod made of a trans-luminescent homogeneous material, wherein the rod is put onto a part of the sclera. Due to the high luminous intensity resulting from the use of such a light rod, provision can be made for a sufficient illumination of the eye fundus, though the sclera is trans-illuminated only at one point. Furthermore, the light rod may consist of the same materials as the ring attachment 1 . The ring attachment 1 as well as the light rod may be covered by a light-reflecting material such as a silver layer or a metal pipe in order to improve the light-conducting ability.
According to a variant of the invention the light rod or the ring attachment can be moved independently from the tube 3 c . In such a case only the light rod or the ring attachment are put onto the eye while the tube 3 c with the wide-angle optics is held at a certain distance to the eye. Here, a mounting of the camera to a cross slide may be advantageous, because one hand is needed for the positioning of the light rod or the ring attachment.
In general it is advantageous, if the hand camera can also be mounted on a cross slide. When the cross slide is mounted at a height-adjustable table, a stationary unit is obtained, when the hand camera is fixed at the cross-slide. With such a stationary unit photos or movies at a sitting patient can be made. For example, for tumor patients it is important that the recordings are made at a sitting patient as well as at a lying patient. The recordings in a lying condition then are made with the hand camera, which is not mounted at a cross-slide. Furthermore, it is possible to connect the camera to a monitor via a cable, so that it is possible to view the camera picture on the monitor.
It is finally noted that the use of the term “cylinder” in the present application is not limited to a circular cylinder. Rather, the term “cylinder” is used in a mathematical sense and generally includes bodies that are limited by two parallel plane surfaces having an arbitrary shape and by a lateral surface that is connecting these surfaces. However, in particular this term shall designate any straight cylinder, in which the lateral surface is perpendicular to the bottom surface and the top surface. | A hand camera for photographing an eye fundus is provided. The camera consists of a tube ( 3 c ), a camera housing ( 3 a, 3 b ), which camera housing is attached to one end ( 3 d ) of the tube in a light-tight way, a camera device ( 4 ) that is able to record images by means of a two-dimensional optical sensor or a photographical film and that is accommodated in the camera housing ( 3 a, 3 b ), a telephoto lens ( 5 ) that is arranged in the beam path of the light that is reflected from the eye fundus, which is accommodated in the camera housing ( 3 a, 3 b ), a wide-angle lens ( 2 ), which is arranged in the beam path of the light that is reflected from the eye fundus at the other end ( 3 e ) of the tube ( 3 c ), and a light supplying device ( 1 ) consisting of a homogeneous trans-luminescent material, wherein the light supplying device ( 1 ) is arranged with respect to the tube ( 3 c ) in such a way that for a sufficient approach of the other end ( 3 e ) of the tube ( 3 c ) to the eye to be examined the light supplying device touches the sclera of the eye, provided that the center of the wide-angle lens is aligned with the center of the pupil. | 0 |
This is a continuation-in-part of application Ser. No. 561,426 filed Aug. 1, 1990 now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method for forming drainage grooves in the surface of a roll which is suitable for processing web-like materials, for example, paper, and a roll machined by said method.
2. Description of the Prior Art
Hereinafter, the procedure with regard to the making of paper will be discussed in more particular detail.
In modern paper making machines a water/fiber mixture having a solid content of about 2% is applied to an endlessly revolving screen. A large part of the water flows through the screen openings so that after a short time, the solid component has increased to about 50%. In the further course of the process, the paper web still of low strength is transferred to an endlessly revolving felt. For further dewatering, the paper web and felt are conducted jointly through the so-called wet press. Such presses are two-roll or multi-roll mills consisting, for example, of a stone roll with one or more pressing rolls. Whereas the stone roll is smooth on the paper side, the pressing rolls are usually grooved on the felt side. Due to the pressure in the roll nip, a further portion of the water is forced into the roll groove and on further rotating of the pressing rolls centrifuged out again. Grooved pressing rolls thus make a decisive contribution to dewatering and consequently, reduce the heating power to be applied in the dry section for further drying the paper.
For corrosion reasons, grooved rolls are made with a special steel covering.
Since this material is very tough and the necessary grooves relatively narrow and deep and although mechanical milling of the grooves is possible, it is very complicated and due to the tool consumption, very expensive.
An alternative method of applying a grooved special steel covering resides in wrapping a specially formed special steel band around a prepared roll body. The profile of this band or strip has a height of about 12 mm and in the region of the groove, a thickness corresponding to the web between the grooves.
At the bottom, the profile is as wide as the web plus groove. When the special steel strip is now coiled under tensile stress and application of pressure onto the roll body, a helically grooved roll surface is formed. Since the starting material is expensive, this method is also very expensive.
Moreover, if after a part of the roll has already been wrapped, the special steel strip tears, the already wrapped part must be freed of the strip again and the winding with a new strip started from the beginning.
SUMMARY OF THE INVENTION
The invention therefore has as its object the elimination of the disadvantages of the prior art outlined above and in particular, to propose a method with which various groove forms can be produced in the surface of such a roll without great expenditure.
The invention therefore proposes in a method for forming grooves in the surface of a roll for processing web-like materials, in particular paper, the improvement that the grooves are formed using a laser beam.
Advantageous forms of embodiment of the method according to the present invention are defined by the feature of the subsidiary claims.
According to the present invention, the focused light beam of a laser source is directed onto the surface of a roll to be grooved. The laser beam very rapidly melts a restricted area of the surface. By blowing the melt point by means of a directed pressurized gas jet, the molten material is blown away. If the roll is now turned, a groove is formed. If the laser source is simultaneously moved in the axial direction of the roll, a helical groove is formed.
By means of the various adjustable parameters of this method, the shape, depth and path of the groove can be adjusted in the manner, for example, necessary for optimizing the dewatering effect of the press roll given by way of example.
As a rule, it is advantageous to generate a protective gas atmosphere preventing, for example, oxidation of the edge regions in the area to be worked at the surface of the roll; thereby, enabling the edge quality of the grooves to be improved. For this purpose, the pressurized gas jet need consist only of inert gases.
In order to reduce the cooling effect of the pressurized gas jet, it is advantageous to heat the pressurized gas.
It is also possible to assist the action of the laser beam by oxidizing gas mixtures. For this purpose, oxygen is admixed with the gas for the pressurized gas jet. The oxidizing gas mixture burns part of the metal and thus, generates additional melting energy.
The grooves should under no circumstances be burnt deeper than 10 mm into the roll cover. Preferably, the groove depth lies in a range between 3 and 7 mm, a groove depth of 5 mm usually being employed.
For certain uses, it may be advantageous to cause the laser beam to strike the roll surface to be worked at an inclined angle. If, for example, the grooves are to intersect, then in the region of the intersecting grooves, the penetration depths of the laser beam into the material would almost summate so that at the groove-intersection points, real holes would be formed. If, however, the laser beam is allowed to impinge on the roll surface at an inclined angle, this effect is largely eliminated. Material-specific reflections of the laser beam may also be positively influenced by angular impinging of the laser beam on the roll surface. In addition, it is easier to remove the vaporized metal from the roll surface which influences very positively the working rate and the groove quality.
The grooves formed using the laser beam in the roll cover should not be wider than 1 mm, preferably 0.3 to 0.7 mm. As a rule, grooves with a width of 0.5 mm are formed.
In the present case, the use of a CO 2 laser is particularly expedient because the technology thereof is sophisticated and proven. Other laser types may also be employed.
Generally, however, laser with energy densities of at least 1 KW, preferably at least 5 KW, should be used for carrying out the method according to the invention.
For forming grooves in the roll surface, the roll to be worked on is disposed in a holder in which the roll can be rotated with a specific uniform velocity about its axis of a rotation. In order to obtain the desired groove depth, the laser beam must have a specific lingering or residence duration in a defined area on the roll surface. This necessary residence duration is taken into account by a correspondingly set rotational speed of the roll. The necessary residence duration can, of course, also be regulated via the energy density of the laser beam.
In order to obtain a helical groove on the roll surface, the operating laser source or the laser beam may be moved along the roll to be worked on. The velocity with which this movement is carried out gives, in conjunction with the rotational velocity of the roll, a certain pitch for the helical groove to be formed.
It is conceivable that under certain conditions, it may be expedient to allow only the roll or alternatively only the laser source or the laser beam to carry out the necessary movements for configuring the groove.
The pitch of the helical groove should be dimensioned so that the distance between two adjacent groove channels is not greater than 10 mm and preferable amount to 5 mm.
For certain uses, it may be advantageous to form in the roll surface not only a helical groove, but, for example, several oppositely running helical grooves which along their path frequently intersect.
It would also be conceivable to form a plurality of radially closed grooves which are interconnected via grooves extending parallel to the roll axis on the roll surface.
It is conceivable to simultaneously introduce two or more parallel grooves by beam splitting to thus shorten the processing time.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described hereinafter in more detail with the aid of the drawings of an example of embodiment from which further advantages features are apparent. In the drawings:
FIG. 1 shows an arrangement for carrying out the method according to the invention in cross-section;
FIG. 2 shows the same arrangement as FIG. 1, but in plan view;
FIG. 3 shows to a larger scale the detail "X" of a roll surface in which grooves are formed by using the method according to the invention; and
FIG. 4 is a sketch to illustrate a principle of the invention for forming grooves.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows schematically a basic arrangement for carrying out the method according to the invention. A roll 10 which is mounted in a holder rotatably and/or displaceably in the direction of the arrow is processed by means of a laser beam 12. The laser beam 12 is generated by a laser source 14. Preferably, a CO 2 laser is used as a laser source 14. Via a supply tube or a hollow needle 20 a protective gas atmosphere or an oxidizing gas atmosphere can be generated in the area momentarily to be processed on the roll surface. If the assisting gas is directed with high pressure to the surface of the roll to be worked on, the gas stream will simultaneously blow the molten, vaporized or burnt materials from the resulting groove and from the processing area of the laser beam 12 on the roll surface.
The roll 10 is turned and simultaneously axially displaced with a certain velocity. By the rotational velocity of the roll, the residence or lingering duration of the laser beam 12 can at a given point of the roll surface be influenced. In other words, for a given set laser-beam-power density of the laser source 14, the depth of the drainage grooves in the roll surface of the roll 10 can be defined by varying the rotational velocity. For a given power of the laser source 14, the roll 10 should not be turned so slowly that the groove depth becomes greater than 10 mm. Preferably, the groove depth should lie between 3 and 7 mm, and, as a rule, should be 5 mm.
The laser beam 12 should act on the surface of the roll 10 over a width of at the most 1 mm, preferably 0.3 to 0.7 mm. As a rule, the laser beam should vaporize the material of the roll surface over a width of 0.5 mm and thus, generate a groove width of 0.5 mm.
By the displacement of the roll in the axial direction, the lateral distance between two adjacent groove channels is defined. The maximum axial displacement velocity of the roll 10 should not form a distance between two adjacent groove channels 18 greater than at most 10 mm, preferably about 5 mm.
Of course, the groove depth can also be set in the intensity of the laser beam 12 is increased or decreased while the roll 10 is rotated with constant velocity.
All the movements may be performed solely by the roll 10 or alternatively, solely by the laser (or laser beam). Preferably, the roll 10 will execute the rotational movement while the laser beam 12 or laser source 14 will execute the axial movement along the axis of the roll 10.
FIG. 2 shows a schematic basic illustration of the arrangement according to FIG. 1 but in plan view. The helical path of the groove 18 can be clearly seen. The groove 18 may, however, also consist of oppositely running helical grooves 18 which intersect. With this configuration, the laser 14 is adjusted so that the laser beam 12 strikes the roll surface perpendicularly. Depending on the use, the laser beam 14 may also be adjusted in such a manner that the laser beam 12 strikes the roll surface at a specific angle between 90° and approximately 0°.
FIG. 3 shows, in an enlarged scale, the detail "X" of FIG. 2. The grooves 18 which have been made by the method according to the invention can be seen clearly. By a corresponding additional inclination angle of the laser beam, the drainage grooves 18 may also be given a path which is not perpendicular to the surface of the roll.
FIG. 4 illustrates a principle of this invention for forming grooves. As illustrated in FIG. 4, a laser beam 22 is used for melting the roll material at the surface of the roll 21 to a depth of 3 mm to 7 mm, and a width of 0.3 mm to 0.7 mm. This laser beam 22 is directed onto the endface 25 of the groove 24 to be formed. Simultaneously, a gas jet is directed onto the endface 25 from a split-shaped nozzle 23, wherein the gas jet completely removes the molten roll material both from the groove 24 and the surface of the roll 21.
As can further be seen in FIG. 4, a first part 26 of the gas jet is deflected from the endface 25 into the groove 24 already formed. The reactive force created by the deflection drives a second part of the gas jet (namely, the gas jet 27) upwardly out of the groove; thereby, transporting by pressure and friction the molten roll material into the second part of the gas jet (i.e., the gas jet 28 blasting the roll material away from the roll 21).
In the above-discussed structural arrangement and method of this invention, the operating parameters thereof are hereinafter set forth.
The surface material of the roll is a non-corrosive steel having the following composition: C<=0.1; Si<=1.0; Mn<=2.0; Cr=16.5-17.5; Mo=2.25; Ni=10.5-13.5; and Fe as the balance.
The laser power is in the range from 5 to 6 KW. The focal distance of the laser beam is 300 mm. The focus of the laser beam is set to a point 1 to 3 mm above the surface of the roll. The operation speed, namely the speed of forming the groove, is set to a value in the range from 1.2 to 1.6 m/min.
The blowing gas has the following composition: 91 Vol. % argon; 5 Vol. % carbon dioxide; and 4 Vol. % oxygen.
A gas amount in the range from 55 to 60 Nm 3 /min. having a blowing pressure of about 10 bar is used. The gas jet impacts the roll surface at a point which is 1 to 2 mm before the point at which the laser beam reaches the roll surface. The gas jet forms an angle of approximately 45° with the surface of the roll. The above operating parameters lead to high quality grooves.
While the invention has been particularly shown and described in reference to preferred embodiments thereof, it will be understood by those skilled in the art that changes in form and details may be made therein without departing from the spirit and scope of the invention. | The present invention is a method for forming grooves in rolls which are suitable for working web-like materials, wherein a laser source directs a laser beam and an aligned conduit directs a pressurized gas jet onto the roll surface, the roll material thus being removed in a sharply defined area and a groove thereby being formed. | 3 |
FIELD OF THE INVENTION
The present invention provides a method and apparatus for substantially sealing a throughbore of a tubular wherein the tubular has a line running therethrough, such that the sealed throughbore can withstand a pressure differential, preferably without any leakage of fluid. The invention also provides a method of substantially filling voids in a line. In particular, the method and apparatus is suitable for use in an oil and gas well in conjunction with a blow-out preventor or wireline valve to effectively seal off a wellbore by filling voids in a wireline in the throughbore.
DESCRIPTION OF RELATED ART
In the oil and gas industry, a “blow-out” is a term used to describe an uncontrolled sudden escape of fluids such as gas, water or oil from a wellbore. A blow-out preventor or wireline valve (hereinafter BOP) is a device used to control formation pressures in a well by sealing the wellbore. BOPs can be provided with a centrally disposed aperture extending parallel to the throughbore of the wellbore to allow tubing or wireline running through the wellbore to remain in position when the wellbore is sealed. Thus, BOPs also allow remedial work to be performed on the tubing or wireline by sealing a wellbore under pressure.
In order to seal the wellbore having a wireline running therethrough, the BOP typically closes a pair of rams to seal around the wireline. However, the BOPs can be required to contain a large pressure differential that may be around 5000-15000 psi (34.5-103.4 MPa) or greater. The wireline usually comprises helically wound strands with voids therebetween. Due to the high pressures that the BOP can be expected to contain, it is desirable to ensure that voids in the wireline do not present potential leak paths for high pressure fluids, such as the produced liquids and gases.
BRIEF SUMMARY OF THE INVENTION
According to a first aspect of the invention, there is provided a method of substantially sealing a throughbore of a tubular, the tubular having a line running therethrough, such that the sealed throughbore can withstand a pressure differential, the method comprising the steps of:
(a) substantially enclosing the line and sealing a portion of the throughbore around the line using an enclosing means; (b) injecting a fluid in the region of the line, wherein the fluid contains solid particles; and (c) substantially sealing a remaining portion of the throughbore using the solid particles such that the sealed throughbore is capable of withstanding a pressure differential.
The method can also include injecting a first fluid in the region of the line and substantially sealing a remaining portion of the throughbore using the first fluid and the solid particles. The method can include injecting the first fluid in the region of the line prior to step (b).
The method can include injecting a greater proportion of the first fluid than the fluid containing solid particles in the region of the line.
The method can include injecting the first fluid and the fluid containing solid particles in series. The method can include injecting the first fluid in the region of the line, followed by injecting the fluid containing solid particles in the region of the line. The method can include injecting between two to five times by volume of the first fluid relative to the second fluid. The method can include filling voids associated with the line using the first fluid and the solid particles. Preferably the throughbore is substantially sealed such that no leak path exists. The pressure differential that the sealed throughbore may be required to withstand can be up to 15000 psi (103.4 MPa) or greater. The pressure differential may be in the range 2000-15000 psi (13.8-103.4 MPa). The pressure differential may be in the range 3000-10000 psi (20.7-68.9 MPa). The pressure differential that the sealed throughbore is arranged to withstand can be in the range 3000-6000 psi (20.7-41.4 MPa).
The method can include settling out solid particles to substantially plug one or more voids in the line. The method can include settling out solid particles from the fluid in response to a drop in pressure of the fluid.
The method can include substantially enclosing the line and sealing a portion of the throughbore around the line by moving a retractable enclosing means into the throughbore. Preferably, the retractable enclosing means are movable into a closed configuration in which the line is centrally disposed and fluids are substantially restricted from flowing through the throughbore. The method can include enclosing the line by moving the enclosing means in a direction perpendicular to an axis of the tubular. The enclosing means can guide the line to and retain the line in the closed configuration. The method can include substantially sealing around an outer profile of the line using a resilient portion provided on the enclosing means.
The method can include providing a pair of axially spaced enclosing means and substantially enclosing the line at two axially spaced locations thereby sealing a portion of the throughbore around the line arranged parallel to one another. The method can include injecting the fluid(s) between the two axially spaced enclosing means. The method can include providing at least one port in selective fluid communication with the throughbore of the tubular, wherein the or each port provides an opening through which the fluid(s) can be injected and wherein the port is located between the axially spaced enclosing means. The method can include injecting the first fluid and the fluid containing solid particles in the region of the line through separate ports and coupling each port to an injection apparatus.
The method can include injecting the fluid(s) at a higher pressure relative to the ambient pressure of the voids such that the fluid(s) are forced into the voids.
The method can include opening one or more apertures between outer elements of the line to allow the fluid(s) access to one or more voids within the line. This can be achieved by forcing the line into an alternative configuration in which the voids are more accessible to the fluids. The method can include twisting the line to open one or more apertures between the outer elements, prior to enclosing the line. The method can include bending the line to open one or more apertures between the outer elements. The method can include shaping a contact surface of the enclosing means to retain the line in a bent or twisted configuration when the enclosing means are in the closed configuration. The method can include inserting one or more protrusions between the outer elements of the line and thereby opening one or more apertures in the outer elements.
According to a second aspect of the invention there is provided an apparatus for substantially sealing a throughbore of a tubular, the tubular having a line running therethrough, such that the sealed throughbore can withstand a pressure differential, the apparatus comprising:
(a) an enclosing means to enclose the line and seal a portion of the throughbore around the line in use; (b) a fluid, wherein the fluid contains solid particles; and (c) at least one injector, wherein the or each injector is capable of injecting the fluid containing solid particles in the region of the line such that the remaining portion of the throughbore is capable of being sealed using the solid particles.
The apparatus can also comprise a first fluid, wherein the at least one injector is capable of injecting the first fluid in the region of the line such that the remaining portion of the throughbore is capable of being sealed using the first fluid and the solid particles.
The line can comprise one or more voids. The line can comprise at least one layer of helically wound elements. The line can comprise an outer layer of helically wound elements and an inner layer of helically wound elements. The elements of the outer layer and the elements of the inner layer can be helically wound in opposing directions. An inner protected portion of the line can comprise one or more cables selected from the group consisting of: hydraulic supply lines; power supply lines; and communications cables. The line may be a wireline.
The first fluid can have a higher viscosity than the fluid containing solid particles. The first fluid can comprise a heavy hydrocarbon, such as grease or glycol.
The solid particles can be in suspension with the fluid. The solids particles in the fluid can be arranged to settle out of the fluid. The solid particles can be arranged to settle out of the fluid in response to a drop in pressure of the fluid. The fluid can comprise solid particles of barite.
The solid particles can have a median grain size between 10 and 250 microns. Preferably, the solid particles can have a median grain size between 25 and 150 microns. The larger median grain size of between 200 to 250 microns is typically suited to use with larger diameter lines.
The fluid(s) can be injected at a pressure higher than the ambient pressure in the region of the voids such that the fluid(s) are forced into the voids.
The enclosing means can be selectively movable into the throughbore to substantially enclose the line and seal a portion of throughbore surrounding the line. The enclosing means can be movable perpendicular to the axis of the tubular to a closed configuration in which the portion of the throughbore surrounding the line is substantially sealed.
A pair of enclosing means can be provided, spaced axially relative to the throughbore. The enclosing means can be a blow-out preventor.
The enclosing means can be provided with a resilient portion that is arranged to substantially seal around an outer profile of the line. The resilient portion can comprise an elastomeric material.
The enclosing means can have a contact surface with a recess therein for engaging the line. The recess in the contact surface of the enclosing means can be shaped so as to at least partially bend the line, or otherwise divert the line from a linear configuration, in order to disrupt the voids and make them more accessible to the fluids. After the line has been treated with the fluids, the bent configuration can optionally be relaxed so that the line assumes its normal configuration once more. The or each enclosing means can be provided in at least two parts and the recess in the contact surface of each part can be profiled to cause the line placed therein to at least partially bend. The contact surface of each part of the enclosing means can be provided with a corresponding substantially S-shaped recess for accommodating the line.
The enclosing means can be provided with one or more protrusions for protruding between one or more elements of an outer layer of the tubular to thereby open an aperture between adjacent elements of the outer armour. The recess in the contact surface of the enclosing means can be provided with one or more protrusions therein for opening adjacent elements of the outer armour.
The apparatus can comprise an opener wherein the opener is arranged to be selectively coupled to the line to grip and twist the outer armour so as to change the pitch of the helix and open apertures and voids between adjacent elements.
The fluid containing solid particles and optionally the first fluid can be injected such that the particles and the fluid(s) fill and thereby seal the one or more voids in the line.
Preferably the method and apparatus are suitable for use in a wellbore.
According to a third aspect of the invention, there is provided a method of substantially filling voids in an apparatus, the method comprising the steps of:
(a) injecting a first fluid in the region of the voids; (b) injecting a second fluid in the region of the voids, wherein the second fluid contains solid particles; and (c) causing the first fluid and the solid particles in the second fluid to fill the voids.
All relevant features and steps of the first and second aspects of the invention are applicable to the third aspect of the invention. The method according to the third aspect of the invention is particularly suited to sealing voids in downhole apparatus.
BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS
Embodiments of the present invention will now be described with reference to and as shown in the accompanying drawings, in which:
FIG. 1 is a part-side, part-sectional view of a blow-out preventor;
FIG. 2 is a perspective view of a pair of rams of the blow-out preventor of FIG. 1 ;
FIG. 3 is a sectional view of the wireline and part of the rams of FIG. 2 ;
FIG. 4 is a close up view of a first alternative ram to those shown in FIG. 2 ; and;
FIG. 5 is a close up view of a second alternative ram to those shown in FIG. 2 and FIG. 4 .
DETAILED DESCRIPTION OF THE INVENTION
A wireline BOP is shown generally at 1 in FIG. 1 . The BOP 1 comprises a body 2 having a throughbore 3 , a pair of upper hydraulic actuators 8 , 9 , and a pair of lower hydraulic actuators 10 , 11 . Each hydraulic actuator in a pair extends radially outwardly from the body 2 and in opposing relation to the other hydraulic actuator in the pair. Each hydraulic actuator 8 - 11 houses an actuator assembly 50 , 51 and a ram 59 , 61 . The actuator assembly 50 , 51 is operable to retractably move the respective ram 59 , 61 provided in the hydraulic actuators 9 , 11 . The rams 59 , 61 are selectively moveable by the associated actuator assembly 50 , 51 between an open configuration as shown for the upper pair of hydraulic actuators 8 , 9 and a closed configuration as shown for the lower pair of hydraulic actuators 10 , 11 . In the open configuration at least part of the throughbore 3 is continuous between the opposing rams 58 , 59 . In the closed configuration, the ram 61 of the hydraulic actuator 11 and the opposing ram associated with the arm 10 engage one another thereby closing the throughbore 3 of the body 2 apart from a centrally disposed aperture. Each hydraulic actuator 8 , 9 is provided with a mechanical backup 8 b , 9 b that can be screwed up behind the actuator assembly 59 to resist separation of the rams 59 once in the closed configuration.
A manifold 14 is provided on the body 2 with a series of inlets 15 , 16 for selectively connecting to pumps (not shown) via conduits (not shown). The inlets 15 , 16 are in fluid communication with the throughbore 3 via openings (not shown) located in the body 2 between the pair of upper hydraulic actuators 8 , 9 and the pair of lower hydraulic actuators 10 , 11 . According to the present embodiment, a first pump suitable for pumping viscous fluid is coupled to a first reservoir (not shown) containing a grease. The first pump is in fluid communication with the inlet 16 . A second pump suitable for use with particle fluids can pump fluid from a second reservoir (not shown) containing a drilling fluid or mud (such as Baracarb™, available from Baroid Drilling Fluids or Enviromul™, available from Halliburton) having finely divided barite particles with a grain size of 25 to 150 microns that settle out of suspension with the fluid in response to a drop in pressure of the fluid. The second pump is in fluid communication with the inlet 15 .
The ram 59 associated with the hydraulic actuator 9 and a ram 58 associated with the hydraulic actuator 8 is shown in the open configuration in FIG. 2 . The rams 58 , 59 are substantially cylindrical in shape with V-shaped guides 58 V, 59 V at a leading end thereof. The rams 58 , 59 also have a contact surface 58 F, 59 F provided with corresponding apertures 5 , 6 and recesses 55 . The rams 58 , 59 are complementary and in the closed configuration (not shown), the rams 58 , 59 interlock with the V-shaped guides 58 V, 59 V overlaid to seal the throughbore 3 . In the closed configuration, the apertures 5 , 6 and recesses align in such a way that a continuous passage is formed for accommodating a wireline. The passage is thus provided in the contact surface 58 F, 59 F of the rams 58 , 59 in order to allow a wireline extending through the bore 3 to remain in position.
A sectional plan view of the rams 58 , 59 in a closed configuration is shown in FIG. 3 . Each ram 58 , 59 has an elastomeric collar 62 , 63 . The elastomeric collars 62 , 63 conform with the outer profile of a wireline shown generally at 88 and therefore form a seal around the outer profile of the wireline 88 when brought into contact therewith.
The wireline 88 is representative of a typical braided wire, but the skilled person will appreciate that there are other configurations of braided wire having differing strand helix arrangements and varying numbers of armour layers.
The wireline 88 comprises an outer armour 82 consisting of a series of helically wound strands 83 and an inner armour 80 consisting of a series of strands 81 helically wound in an opposing direction to the strands 83 of the outer armour 82 . The wireline 88 has a core 86 containing one or more cables 84 . Since the strands 81 , 83 of the inner armour 80 and outer armour 82 respectively are helically wound in opposing directions there is no nesting of the strands 81 in ridges between the strands 83 of the outer armour 82 . As a result, a series of outer voids 90 exist between the inner armour 80 and the outer armour 82 . A number of inner voids 92 also occur between the strands 81 of the inner armour 80 and the core 86 of the wireline 88 .
Before use, the wireline BOP 1 is typically positioned at a wellhead (not shown) with the body 2 arranged such that the throughbore 3 is substantially vertical and co-axial with a throughbore of the wellhead. During normal operation of the wellbore, production fluids are recovered from the well (not shown) in a controlled manner and both pairs of hydraulic actuators 8 - 11 are in the open configuration.
Should the throughbore 3 require to be closed, for example, to resist a blow-out from the well or to conduct remedial work on a portion of wireline 88 downstream of the BOP 1 , the rams 58 , 59 , associated with the hydraulic actuators 8 , 9 are hydraulically activated by the actuator assembly 50 to move into the closed configuration. As the opposing rams 58 , 59 are moved towards one another, the V-shaped guides 58 V, 59 V contact the wireline 88 and guide it towards the centrally disposed passage created by the apertures 5 , 6 and recesses 55 . In this way the throughbore 3 is substantially sealed and the wireline 88 is captured within the passage. The elastomeric collars 62 , 63 seal around the outer profile of the wireline 88 . The mechanical backup 8 b , 9 b can be screwed into position behind the actuator assembly 50 to retain the rams 58 , 59 in their closed configuration in the event of a failure of the hydraulic system. Similarly, the rams housed within the lower pair of hydraulic actuators 10 , 11 are moved into the closed configuration.
The inner and outer voids 92 , 90 remain unsealed within the wireline in the throughbore 3 and therefore pose a potential leak path. Accordingly, viscous grease is first pumped through the inlet 16 of the manifold 14 to the opening between the upper and lower hydraulic actuators 8 - 11 . The grease is injected through the openings at a higher pressure than the well pressure and substantially fills the inner and outer voids 92 , 90 . The pumping continues until a steady leak of the grease is registered and the well pressure is controlled at an acceptable level that enabling the seal to withstand a certain predetermined pressure across the throughbore 3 . The first pump is stroked until the sealed area between the hydraulic actuators 8 - 11 is packed with grease and the voids 90 , 92 are filled with sufficient grease. At this stage, a drilling fluid containing solid barite particles is pumped through the opening located between the pairs of hydraulic actuators via the inlet 15 of the manifold in order to plug the voids 90 , 92 in the wireline 88 . The second pump forces drilling fluid out of the openings at high pressure. However, the pressure of the fluid drops once pumped into the wireline 88 and the energy loss causes, the finely divided barite particles to settle out of suspension with the fluid and plug the voids 90 , 92 thereby blocking the leak path and substantially sealing the voids 90 , 92 within the wireline 88 .
In order to avoid a situation where the outer voids 90 are bridged prior to plugging the inner voids 92 it may be necessary to open gaps between one or more strands 83 of the outer armour 82 to allow the fluids access to the inner voids 92 and avoid initial bridging of the outer armour 82 prior to sealing the inner voids 92 . There are several alternative methods by which this can be achieved.
The contact surface 58 F, 59 F of the rams 58 , 59 in the region of the apertures 5 , 6 or recesses 55 can be provided with one or more small protrusions shown in FIG. 4 . These protrusions can have a pointed end and can be arranged such that the pointed end nests between outer strands 83 to thereby part two or more of the strands 83 and open gaps therebetween.
In an alternative embodiment, the contact surface 58 F, 59 F of the rams 58 , 59 can be provided with corresponding S-shaped recesses (shown in FIG. 5 ) such that the wireline 88 conforms to a bent shape when the wireline BOP 1 occupies the closed configuration. A bending of the wireline 88 has the effect of opening the outer strands 83 on outside edges of the S-bend.
Alternatively, prior to or simultaneous with sealing the BOP 1 an opener (not shown) can be provided to grip around the outer armour 82 and twist the strands 83 to thereby alter the pitch of the wireline 88 helix and open gaps between the strands 83 .
Using the above described method, the throughbore 3 is sealed by the rams 58 , 59 and the voids 90 , 92 can be filled and sealed to eliminate potential leak paths and contain high pressures within the wellbore.
Modifications and improvements can be made without departing from the scope of the invention. In particular, the embodiment described above concerns sealing the wellbore using a wireline BOP 1 . However, the general method of sealing voids within apparatus according to the present invention can be used in other applications. Although the above described embodiment utilises grease in addition to the drilling fluid for sealing the wireline 88 , it will be appreciated that the drilling fluid can be used without the grease for the same purpose of sealing voids in a wireline 88 . The fluid containing solid particles that is the drilling fluid or mud according to the described embodiment can be selected according to the specific application and the diameter of the wireline 88 . For example, wireline 88 having a greater diameter may be used with drilling muds having a larger median grain size of around 200 to 250 microns. | An apparatus and a method of substantially sealing a throughbore of a tubular with a line running therethrough. The method comprises the steps of: (a) substantially enclosing the line and sealing a portion of the throughbore around the line using an enclosing means; (b) injecting a fluid that contains solid particles in the region of the line; and (c) substantially sealing a remaining portion of the throughbore using the solid particles such that the sealed throughbore is capable of withstanding a pressure differential. The method can include settling out the solid particles from the fluid in response to a drop in pressure of the fluid during step (b). The method can include injecting a first fluid in the region of the line prior to step (b). The first fluid can be a heavy hydrocarbon such as a grease and the fluid containing solid particles can be a drilling fluid. | 4 |
BACKGROUND OF THE INVENTION
The invention relates to an x-ray diagnostic generator for operation with falling load with a function generator which, during an x-ray exposure, generates a rated signal value for the x-ray tube output proceeding according to a falling exponential function, which effects the adjustment of the x-ray tube output via control means.
As a function generator, it is known to employ a capacitor which is charged before the beginning of an exposure to a value which corresponds to the peak value of the x-ray tube output and is discharged via a discharging resistor during an exposure corresponding to the temporal course of the highest allowable x-ray tube output (German OS No. 2,122,138). Thereby, the capacitor represents the rated value generator in a control loop for the x-ray tube output. The actual value of the x-ray tube output is thereby independent of disturbances, for example network voltage fluctuations.
In an x-ray diagnostic generator of this type, it is possible that, for instance because of a faulty working of the control means or of the controlled-gain amplifier, an overload of the x-ray tube ensues because the actual value of the x-ray tube output remains constant during an exposure despite the exponential drop of the rated value signal.
SUMMARY OF THE INVENTION
The object of the invention is to design an x-ray diagnostic generator of the type initially cited in such manner that, upon errors in the operation of the control circuit which is to lower the x-ray tube output during an exposure, i.e., when the x-ray tube voltage is not lowered in correspondence with the designed course during an exposure, an overload of the x-ray tube is prevented.
This object is inventively achieved by means of a comparator for the actual and the rated value of the x-ray tube output which is connected to a cut-off element for the x-ray tube and effects cut-off of x-ray tube operation when the difference between the actual and the rated value exceeds a predetermined limit. In the inventive x-ray diagnostic generator, the comparator monitors the difference between actual and rated value of the x-ray tube output. Upon errors in the circuit adjusting the x-ray tube output, the x-ray tube is switched off, and thus, an overload is prevented. A particularly expedient further development of the invention resides in the provision of a time function element which lies between the comparator and the cut-off element, which time function element relays a cut-off signal of the comparator to the cut-off element only when the cut-off signal is present at the input of the time function element during a programmed minimum tube span. Thereby, short-term disturbances and interference pulse spikes are blanked out.
In the following, the invention is explained in greater detail on the basis of a sample embodiment illustrated in the drawing; and other objects, features and advantages will be apparent from this detailed disclosure and from the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows an illustration of the course of the highest allowable x-ray tube output upon operation with falling load; and
FIG. 2 is a circuit diagram showing an x-ray diagnostic generator according to the invention.
DETAILED DESCRIPTION
It proceeds from FIG. 1 that the highest allowable x-ray tube output P decreases exponentially from an initial value P A down to a constant value P D . When the x-ray tube output is lowered during the production of an exposure in correspondence with the curve illustrated in FIG. 1, then the x-ray tube is always operated with its highest allowable output, i.e., the anode temperature is practically constant and has the highest allowable value and, upon termination of an exposure by means of an automatic exposure control, the shortest possible exposure time is thereby attained.
In the x-ray diagnostic generator illustrated in FIG. 2, the lowering of the x-ray tube output ensues in exact correspondence with the optimum course according to FIG. 1. The x-ray diagnostic generator, which supplies and controls an x-ray tube 1 and of which only the parts essential to the invention are illustrated, contains two high voltage rectifiers 2 and 3 which lie in series with one another and are supplied by the secondary windings 4 and 5 of a three-phase high voltage transformer. The x-ray tube current, which is adjustable via the filament current of the x-ray tube 1 via control means 6, traverses a voltage divider resistor 7 at which a voltage proportional to the x-ray tube current is tapped by means of a tap 8. A manually adjustable voltage selector 9 serves for the adjustment of the high voltage at the x-ray tube 1, which voltage selector influences a regulating transformer preconnected to the primary 26 of the high voltage transformer and also shifts the tap 8 corresponding to the respectively selected x-ray tube voltage. Because the x-ray tube voltage is held constant by means of known means not illustrated, a voltage lies between the line 10 and 11 which is proportional to the product of the x-ray tube voltage and the x-ray tube current, i.e., is proportional to the respective actual value of the x-ray tube output.
The actual value generator 7, 8 for the x-ray tube output is a component part of a control loop which contains a rated value generator which consists of a capacitor 12 and a discharging resistor 13 for the capacitor 12. Before the beginning of an exposure, the capacitor 12 is chargeable, with switch 14 in its illustrated upper position by means of a voltage tapped at two voltage dividers 15, 16 and 17, 18. During the production of an exposure, the switch 14 assumes its lower position indicated by a broken line and the capacitor 12 discharges itself via the discharging resistor 13. The voltage dividers 15, 16 and 17, 18 which are fed by a constant voltage source 19 are dimensioned in such manner that the voltage at capacitor 12 corresponds to the difference between the initial output P A and the constant output P D (FIG. 1) when the capacitor 12 is fully charged. The discharging resistor 13 is dimensioned in such manner that the voltage at capacitor 12 decreases during the discharge corresponding to the temporal course of the highest allowable x-ray tube output according to FIG. 1.
A voltage is present at the input of an amplifier 20 which corresponds to the difference between the voltage tapped at the discharging resistor 13 and at the voltage divider resistor 7, i.e., corresponds to the respective deviation of the actual value of the x-ray tube output from its rated value. Via line 21, the amplifier 20 influences the control means 6 for the x-ray tube current and thus for the x-ray tube output in such manner that the actual value of the x-ray tube output is readjusted to the rated value respectively prescribed by the voltage at the discharging resistor 13.
In the x-ray diagnostic generator illustrated in FIG. 2, the x-ray tube output during the production of an exposure proceeds exactly in correspondence with FIG. 1, i.e., it decreases exponentially from the highest allowable initial value P A to the constant value P D and has its highest allowable value at each point in time. With the termination of the exposure by means of an automatic exposure control, thus, the shortest possible exposure time is always attained. Disturbances, particularly network voltage fluctuations, are automatically leveled and practically do not influence the lowering of the x-ray tube output during the production of an exposure.
The divisor ratio of the voltage dividers 15, 16 and 17, 18 is determined once for a specific x-ray tube and then needs not be changed again upon operation of the x-ray diagnostic generator with this x-ray tube.
In the x-ray diagnostic generator according to FIG. 2, it can occur that the controlled-gain amplifier 20 or the control means 6 are defective. In order to prevent an overload of the x-ray tube in this case, a comparator 22 is present to which a signal corresponding to the actual value of the x-ray tube output is applied at its inputs a and a signal corresponding to the rated value of the x-ray tube output is supplied at its inputs b. The comparator has a predetermined threshold for the difference between this actual and rate value. When this difference thus exceeds a predetermined value, the comparator 22 delivers a signal to a time function element 23. The time function element 23 relays this signal when it pends at the input of the time function element 23 during a programmed minimum time span of, for example, 50 ms. In this case, a cut-off element 24 is activated which actuates the switches 25 which disconnects the primary windings 26 of the high voltage transformer 4, 5, 26 from the network and, thus, also switches the x-ray tube 1 off.
The comparator 22 can, for example, be programmed in such manner that it supplies a signal to the time function element 23 for shutting off the x-ray tube when the difference between the actual and the rated value of the x-ray tube output exceeds 2kW. Of course, this switching off only ensues when this transgression is present during the programmed minimum time of, for example, 50 ms in the time function element 23.
By way of example, the time function element 23 may be a timing circuit which requires the presence of the cutoff signal from comparator 22 substantially continuously for the duration of its timing cycle. For example if the timing circuit involves the timing of the discharge of a capacitance to a low voltage value which is reached only after discharge of the capacitor for fifty milliseconds, the discharge circuit may be controlled by a transistor which also shunts the charging source and thus prevents recharging the capacitance only so long as the cut-off signal holds the transistor in the conductive mode. Thus the capacitor is recharged at a predetermined relatively rapid rate if the cut-off signal is interrupted prior to the fifty-millisecond required duration, thereby resetting the timing circuit to its initial condition provided the cut-off signal is interrupted for a sufficient interval to be consistent with safe continued operation of the x-ray tube. When the timing capacitor is discharged to a predetermined low voltage value, an output transistor circuit may be triggered which holds contacts 25 open until manually reset.
It will be apparent that many modifications and variations may be effected without departing from the scope of the novel concepts and teachings of the present invention. | In an exemplary embodiment, a comparator is present which compares the actual value of the x-ray tube output with a time-varying rated value output of the function generator which controls the falling load characteristic, and effects the switching off of the x-ray tube to prevent an overloading thereof if the difference between the actual and the rated value of the x-ray tube output exceeds a predetermined limit for a time interval exceeding a predetermined minimum time span. | 7 |
FIELD OF THE INVENTION
[0001] The invention relates to an alert system and related methods to monitor hydrocarbon production facilities including downhole installations, wellhead, long tie-backs between oil-wells and storage tanks or processing plants.
BACKGROUND
[0002] During the production of hydrocarbons, the hydrocarbons and other by-products flow from the wells drilled into the reservoir to storage facilities or a processing plant. The pipelines and other installations required for this transport are usually referred to as tieback. The flow of hydrocarbon is subject to changing environmental conditions such as changing temperature, pressure, and composition. The changing conditions often cause the precipitation of components out of the main flow.
[0003] In this context, management of changing phases like liquids, gases and solids precipitation can be regarded as being fundamental for the assurance of fluid flow along the production systems. Organic (hydrates, waxes, Asphaltenes, naphthanates) or inorganic solids (BaSO 4 , CaCO 3 , SrCO 3 ) may obstruct the formation pores and deposit on the wellbore or pipeline walls blocking the fluid production.
[0004] In the oil and gas industry, studies are developed to analyze the flow conditions and operations procedures throughout the life of the field. The objective of those studies is to understand the environment, boundary conditions and property changes along the fluid journey from the pore volume of the reservoir to process facilities and point of sales.
[0005] To characterize the production, the oil and gas industry is recently focusing, particularly for large subsea developments, on intelligent field solutions and new systems for production control and monitoring as for example presented in: Gudimetla, A. Carroll, K. Havre, C. Christiansen, and J. Canon, “Gulf of Mexico Field of the Future: Subsea Flow Assurance”, OTC 18388, 2006 and G. G. Lunde, K. Vannes, O. T. McClimans, C. Burns, and K. Wittmeyer, “Advanced Flow Assurance System for the Ormen Lange Subsea Gas Development”, OTC 20084, 2009. These recent systems for production management are designed to assist decision making and to provide guidance for the daily operations and future investments. They can perform model-based simulations to represent the production conditions and address potential issues. Generally these systems attempt to address flow assurance problems.
[0006] The model-based simulations represent reservoirs, wells, pipelines, production networks and facilities. Those models range from “black oil” to compositional and from steady state to transient. When calibrated with available measurement data as proposed for example in J. Ratulowski, A. Amin, A. Hammami, M. Muhammad, M. Riding, “Flow Assurance and Subsea Productivity Closing the Loop with Connectivity and Measurements”, SPE 90244-MS, 2004 or by A. Amin, E. Smedstad, M. Riding, “Role of Surveillance in Improving Subsea Productivity”, SPE 90209-MS, 2004 and laboratory fluid characterization data such as illustrated in: A. K. M. Jamaluddin, J. Nighswander, N. Joshi, “A Systematic Approach in Deepwater Flow Assurance Fluid Characterization”, SPE 71546-MS, 2001, such models can be used to estimate fluid properties throughout the system.
[0007] Software tools to assist the assessment of potential flow assurance problems are commercially available by many vendors and include for example steady-state fluid flow simulators such as PIPESIM™, transient fluid flow simulators such as OLGA™, fluid analysis software designed to predict the thermodynamic precipitation point of waxes and asphaltenes such as dbrSOLIDS™, and integrated asset modeler simulators such as Avocet™ IAM capable of modeling the fluid flow from the reservoir through to refining stages. Those tools allow production engineers to understand potential system problems, such as flow restrictions due to solids precipitation and deposition.
[0008] The use of the model-based simulation to create operation profiles is well known in the industry, these profiles are used to evaluate the risk of solids precipitation and deposition along the flow path. However in the light of the known methods it is seen as an object of the present invention to provide a method of monitoring different types of possible solids from each fluid footprint, and at different timeframes.
SUMMARY OF INVENTION
[0009] The present invention provides a method for monitoring a fluid flow in a flow line from a location in a subterranean reservoir to a surface storage or production facility using the steps of employing sensors located in the wellbore and along the flow line for monitoring flow conditions, establishing parameters which determine the precipitation of solid components from the fluid flow, setting alert parameters relating to the precipitation parameters, and determining an operating profile representative of present conditions along the flow line, wherein the precipitation parameters, the alert parameters and the operating profile and extrapolation of the operating profile are represented in a single parameter space.
[0010] The invention provides in a preferred embodiment a method of representing important flow assurance parameter as linked to the precipitation of organic and/or inorganic flow components in a compact representation. This representation facilitates the setting, the monitoring and the display of alarm thresholds.
[0011] In another preferred embodiment, the invention includes the use of subterranean sensors to update flow models of the reservoir so as to provide a long-term projection or extrapolation of the operating profile. In turn, this extrapolation in combination with the other features of the present invention can be used to define operating guidelines which reduce or avoid precipitation.
[0012] These and other aspects of the invention are described in greater detail below making reference to the following drawings.
BRIEF DESCRIPTION OF THE FIGURES
[0013] FIG. 1 illustrates an schematic example of a production system;
[0014] FIG. 2 is a reduced version of a diagram combining precipitation curves and operating profile;
[0015] FIGS. 3A-D illustrate a more detailed version of a diagram combining precipitation curves, alert curves and real-time and extrapolated operating profiles; and
[0016] FIG. 4 is a block diagram showing elements and steps of an example of the present invention.
DETAILED DESCRIPTION
[0017] In the following example FIG. 1 shows a schematic example of an off-shore subsea production system, which represents the fluid journey from the pore volume of the reservoir 10 to an initial processing facility 17 on an offshore platform 18 . The fluid path includes a subterranean completion 11 , a well head 12 located at the seabed, a subsea manifold 13 , pumping devices 14 and a subsea pipeline or tie-back 15 through a marine riser 17 to the platform 18 . The fluid path is regularly monitored due its changing conditions relating to pressure, temperature and flow rates. Key points of this monitoring system along the production system include the reservoir, the manifold and the production platform are highlighted with circles and referred to in the following figures and plots.
[0018] The system can be implemented using known subsea and surface devices as described in the above cited documents and particularly in G. Deans, R. MacKenzie, “Enabling Subsea Surveillance: Embracing “True Production Control” With An Open Architecture Subsea Monitoring And Control System”, Conference Subsea Controls and Data Acquisition 2006: Controlling the Future Subsea, Jun. 7-8, 2006, Neptune, France SCADA-06-074.
[0019] Using such an infrastructure of sensors and other monitoring devices, different commercial software packages as referred to above can be used to calculate the fluid multiphase envelope and operating profiles. A schematic example of phase envelopes combined with an operating profile in a P-T or thermo-hydraulic plot is shown in FIG. 2 . This plot demonstrates how the flow assurance surveillance and alarm system as proposed by the present invention enables a definition, monitoring and display of alert threshold for solid precipitation. The figure shows the fluid phase envelope 21 , a hydrate precipitation curve 22 , a wax precipitation curve 23 and an operating profile 24 . The circles on the dashed line 24 of the operating profile indicate critical path points (reservoir, manifold, facility) as identified in FIG. 1 above.
[0020] A more complex example is shown in FIG. 3A . This figure include not only the phase envelope or bubble point curve 310 , the wax curve 320 and the hydrate curve 330 as in FIG. 2 , it also includes an asphaltene precipitation curve 350 and further inorganic solids equilibrium curves such as barium sulfate (BaSO 4 ), calcium carbonate (CaCO 3 ) and strontium carbonate (SrCO 3 ). In the example, real-time data acquisition from field instrumentation is combined with laboratory fluid characterization data to run simulation models for monitoring the production system via the operating profiles 340 and their extrapolations 341 , 342 in time. Details of this complex diagram are shown in isolation in the following two figures.
[0021] In FIG. 3B , the precipitation curves of the organic flow hindrance components of FIG. 3A are shown in isolation, i.e., the phase envelope or bubble point curve 310 , the wax curve 320 , the hydrate curve 330 and the asphaltene precipitation curve 350 . Each of the wax curve 320 , the hydrate curve 330 and the asphaltene precipitation curve 350 are shown shadowed by respective alarms boundaries 321 , 331 , 351 shown as dotted lines. The alarm boundaries are set by the operator for example in accordance with the operator's risk management strategy. Taking wax as an example and assuming the produced fluid has a WAT (Wax Appearance Temperature) of 30° C. and the operator consider that 10% above this temperature should be an alert zone, an offset alarm curve 321 as shown is defined. An alarm is triggered if the operating profile reaches the alert curve. Similar procedures can be applied to define the alarm curves 331 , 351 for the other organic solids.
[0022] In FIG. 3C , it is the precipitation curves of the inorganic flow components of FIG. 3A , which are shown in isolation with the bubble point curve 310 , i.e., the barium sulfate (BaSO 4 ), the calcium carbonate (CaCO 3 ) and strontium carbonate (SrCO 3 ) curves. Each of the curves are shown shadowed by respective alarms boundaries BaSO 4 -1, CaCO 3 -1, and SrCO 3 -1 represented by dotted lines. The alarm boundaries can be set by the operator in accordance with a risk management strategy.
[0023] The operating profiles 340 and their extrapolations 341 , 342 in time of FIG. 3A are shown in isolation in FIG. 3D . In the example, the first operating profile 340 is a real-time representation of the operating conditions in the P-T plot. The production system model and fluid modeling combined with the real-time data available from instrumentation for validation are used to generate this real-time model-based simulation curve for the purpose of real-time monitoring.
[0024] The first extrapolated curve 341 can be referred to as a daily production look-ahead operating profile. This profile is taken as an example of a short-term look-ahead scenario for production operations surveillance as generated best by a transient simulation model such as OLGA. It provides an overview of the possible event on the near future. On this profile the look-ahead or extrapolation time step should be relatively short ranging for example from minutes to days. For this short period the conditions on the reservoir pressure and temperature should not change significantly. Hence the model can be limited to the extrapolation of the operating conditions from the wellhead and beyond.
[0025] In case the short-term look-ahead scenario touches the alarm boundaries, the system is capable of indicating the need for remedial action. The alert enables an operator to schedule remedial action ahead of time, hence avoiding or reducing potential bottlenecks or loss of production.
[0026] The second extrapolated curve 342 can be referred as reservoir management look-ahead operating profile. This profile is taken as an example of a long-term look-ahead scenario and is generated from an integrated simulator by coupling a reservoir model with the production system model. The reservoir model is a geological model of the subsurface reservoir 10 and can be built by combining available seismic, logging and other geophysical data using standard software tools such as Petrel™. To model the fluid flow in the reservoir it may be necessary to combine the reservoir model with a flow modeling software such as Eclipse™. The long-term look-ahead scenario seeks to encompass changes in the reservoir and hence its time steps are measured typically in weeks or months or even years. It can be scheduled in line with full field reviews or assessments, which require an extended forecast of the field operations based on the future conditions. A benefit of long-term look-ahead scenario is expected to be the capability of changing production conditions such that precipitation is reduced or avoided without having to resort to remedial actions, hence enabling preventive actions.
[0027] All the data acquired from field instrumentation and sensors and generated by the simulators as described above are fed into a data hub that assures the correct data flow between the software packages to monitor the selected parameters and regulate the surveillance alarms. A flow chart listing components and steps of the above example of the invention is illustrated in FIG. 4 .
[0028] The system as described by FIG. 4 includes interfaces to real-time and other sensors 41 detecting and monitoring changes of external parameters along the path of the fluid from the well to the processing facility. The interfaces link the field sensor output to a data hub 42 , which acts as a data formatting and storage center providing in turn a data flow to the simulation 43 and graphic display unit 44 .
[0029] The simulators 43 used for this example are combining steady-state simulator and transient state simulator.
[0030] The system has three main operating modes. The first monitors the operating profile in real-time to generate alerts, if the real-time operating profiles crosses a precipitation curve. The second mode monitors the crossing of the real-time operating profile with any of the alerts curves or thresholds defined above. In this mode, alarms can be raised by the system and a short-term look-ahead simulation can be initiated.
[0031] Further components include data-driven models such as neural networks 45 to adjust the system based on past conditions and a reservoir simulator 46 to provide a long-term look-ahead simulation of the operating profile. The long-term look-ahead simulation can be part of the decision making process to change well and production parameters such that the operating profile remains within the desired limits as defined by solid precipitation.
[0032] The above system includes a static configuration part which defines an operational space the boundaries of which are at least partly defined by the solid precipitation curves. It defines the parameter space in which the operating profile can change without triggering remedial action. In another variant, the static part can be at least partially replaced by a constant update as provided by sensors performing a real-time compositional flow analysis.
[0033] The system also has a second dynamic component, the monitoring part, which receives field data and updates simulation results to determine real-time and extrapolated operating profiles and display these profiles with the operational space as defined by the configuration part. A third component, the diagnostic part, is initiated or triggered boundary condition violation leading to decisions on short-, medium- or long term remedial action and, if required, to a model re-calibration. By its nature this latter part is invoked sporadically as alert thresholds or precipitation boundaries are approached or crossed by the operating profile.
[0034] While the invention is described through the above exemplary embodiments, it will be understood by those of ordinary skill in the art that modification to and variation of the illustrated embodiments may be made without departing from the inventive concepts herein disclosed. Moreover, while the preferred embodiments are described in connection with various illustrative processes, one skilled in the art will recognize that the system may be embodied using a variety of specific procedures and equipment and could be performed to evaluate widely different types of applications. Accordingly, the invention should not be viewed as limited except by the scope of the appended claims. | A method is described for monitoring a fluid flow in a flow line from a location in a subterranean reservoir to a surface storage or production facility using the steps of employing sensors located in the wellbore, along the flow line and surface systems for monitoring flow conditions, establishing parameters which determine the hydrocarbon phases like liquids and gases, precipitation of solid components from the fluid flow as a result of changes in temperature, pressure and compositions, setting alert parameters relating to the precipitation parameters, and determining an operating profile representative of present conditions along the flow line, wherein the precipitation parameters, the alert parameters and the operating profile and extrapolation of the operating profile are represented in a single parameter space. | 4 |
BACKGROUND OF THE INVENTION
The processing of pulp fibers requires several steps before the fibers can be used to manufacture paper. Some of these processes include pressing, washing and liquor extraction. These steps are performed by presses and washers that contain filtering surfaces with openings large enough for some fibers to pass through. The liquor, while flowing through the filtering surface therefore, carries with it a certain amount of fibers.
It is highly desirable to capture the fibers contained in the filtrate as they would otherwise represent loss of usable product and a source of disposal problems. In order to capture the fibers a filtering surface with openings small enough so that only the liquid can go through is required. This permits the collection of fibers. Such a machine is referred to by the present assignee as a Fibresaver Screen. There is a market demand for a screen with openings of 0.004" in diameter, or even smaller. The filtrate of the other machines described above would be fed into this machine in order to recover as many fibers as possible. Typically such a screen may be formed into the shape of a basket or hollow cylinder. Due to the manufacturing process and the economics of manufacturing a screen basket with very small openings the basket thickness cannot exceed a certain value. Usually the smaller the opening, the thinner the basket. For example, a basket with 0.1 millimeter (0.004") holes would have a thickness of no more than 1 millimeter (0.04"). In a production machine of any size a screen basket of this thickness requires a supporting structure in order to handle the loads acting on it without failing.
The foregoing illustrates limitations known to exist in present devices and methods. Thus, it is apparent that it would be advantageous to provide an alternative directed to overcoming one or more of the limitations set forth above. Accordingly, a suitable alternative is provided including features more fully disclosed hereinafter.
SUMMARY OF THE INVENTION
Our initial objective was to remove individual fibers from process liquor efficiently and cost effectively. This required the use of conventional pressure screens using cylindrical screenplates having very small holes. These small holes are cut by an electron beam or equivalent method and for this method of manufacture the plate must be much thinner than is desirable for strength. The holes are closely spaced to maximize capacity which results in very narrow ligaments between holes. Thus the screenplate has low strength, and for typical operating conditions can sustain only a small span between supports. Typical conventional means of reinforcement obstruct flow area and significantly reduce throughput capacity.
All embodiments of the present invention satisfy the initial objective in providing a strong and rigid screen cylinder assembly having maximum unobstructed area. The most frequent use of this invention will likely be in outward flow screen cylinders as described herein; however, an inward flow screen cylinder may adapt the present invention.
In one aspect of the present invention the above is accomplished by providing a support structure for a screen basket having a screen comprising a thin screen; a screen support means having minimum screen contact area to permit maximum flow through the screen; and means for positioning and supporting the screen support means.
The foregoing and other aspects will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawing figures.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
FIG. 1 is a partial longitudinal cross section of a screen basket according to the present invention showing the screen and a supporting structure according to the present invention;
FIG. 2 is a partial longitudinal cross section of a screen and its supporting structure according to an alternative embodiment of the present invention;
FIG. 3 is a cross section taken at Section 3--3 of FIG. 2;
FIG. 4 is a cross section of a second alternative embodiment of the present invention;
FIG. 5 is a partial longitudinal cross section of a third alternative embodiment of the present invention;
FIG. 6 is a partial cross section taken at Section 6--6 of FIG. 5; and
FIG. 7 is a partial longitudinal cross section of a fourth alternative embodiment of the present invention.
DETAILED DESCRIPTION
According to the present invention a first proposed support structure for a vertically oriented screen basket is; shown in FIG. 1. Please note the screen axis may be horizontal or vertical in use. In the orientation shown, a number of thin horizontal rings 10 are shown evenly spaced longitudinally about the screening basket 20. The screening basket 20 may, for example, be a cylindrical formed structure of screen material. For a Fibresaver Screen the thickness of the screen may be approximately 1 millimeter (0.04") being perforated with closely spaced holes of, for example, 0.1 millimeter (0.004") in diameter or even smaller. The rings 10 circumferentially support the screening basket. A number of vertical slotted-ribs 15 position and further support the horizontal rings. The rings and slotted ribs form a support structure in which the screening basket 20 is positioned. The vertical ribs contain slots 17 which are evenly spaced and into which the rings fit for easy assembly and control of the ring spacing. The ring thickness is maintained to a minimum and the vertical ribs are positioned so that they do not come in contact with the basket 20 in order to maximize the open area. The vertical ribs extend from a top mounting flange 22 to a bottom mounting flange 23 and are also further designed to withstand any vertical compression that the basket may be subjected to. Vertical precompression of the basket is sometimes necessary to prevent torsional vibration.
The top and bottom mounting flanges may also be used to mount the screening basket within the Fibresaver drum (not shown). In typical use the fiber containing liquor is introduced into the Fibresaver drum at the top and passes through the central portion of the screen to an outlet at the bottom of the drum. Liquid filtrate extracted from the liquor passes through the screening basket and generally exits a port in the side of the drum. The recovered fiber exits the bottom of the drum in the conventional manner well known to Fibresaver drum technology.
FIG. 2 shows an alternate embodiment for the support structure wherein a rib 11 of substantially triangular cross section is spot welded to a vertical support rib 16 which in turn is disposed between a top and bottom flange 22, 23 respectively. FIG. 3 shows the cross section taken at Section 3--3 of FIG. 2 and shows a suggested radial spacing of the vertical ribs.
FIG. 4 shows a second alternative embodiment wherein vertical ribs 12 are in contact with the screening basket 20. The vertical ribs of this embodiment are supported and evenly spaced by horizontal slotted rings.
A third alternate embodiment is shown in FIGS. 5 and 6. In this configuration the thin perforated screenplate 20 is supported by a series of vertical support rods 25 which in turn are supported by a perforated cylindrical plate support frame 26. As shown in FIG. 5 the screen is attached at its end to a cylindrical spacer 30 for screen support. Vertical support rods 25 are suitably spaced and disposed within the external gap formed between the screen and the cylindrical support frame or plate 26. The support frame 26 may be constructed from a rolled cylindrical plate having relatively large holes or other shaped openings. These openings would be staggered so that they do not line up vertically. In construction the thin screening plate may be attached by electron beam or resistance welding or the like to the series of support rods. The screenplate 20 and rod 25 assembly can be rolled to the required curvature and assembled to the support frame 26 by means of attaching the rods to the support frame. To facilitate this a vertical strip 27 is provided to locate the screen.
FIG. 7 shows a fourth alternative embodiment wherein: the principle employed is that wire 30 is wound spirally around a cylindrical screenplate 20 such as to resist bursting (and/or buckling) forces in a radial direction. The pitch of the spiral being selected to suit the permissible unsupported span of the perforated plate. The outer strips 35 provide axial stiffness together with torsional stiffness in both directions to resist buckling and twisting.
The spirally reinforced assembly may be manufactured as follows: using a mandrel to ensure accurate dimensions the screenplate is formed into a cylinder around the mandrel and seam welded; then the top mounting flange 22 and bottom mounting ring (not shown) are weld assembled to the cylinder; next, the reinforcing wire may be wound spirally around the apertured length of the screen cylinder and attached by resistance welding; and finally the relatively wide and thin outer reinforcing strips 35, having been preformed to a spiral shape, are resistance welded to the spiral wires 30 at each crossing and welded to the mounting flanges. Note that a single or multiple start helix may be selected formed or wound to any desired pitch to accomplish the degree of stiffness, stability, and support required.
Compared to a conventional rolled and welded thick screenplate having machined fine slots, the overall radial thickness of the spirally reinforced assembly will not be significantly greater, and the radial dimensional accuracy of the screening surface will be significantly better. That is, it can be physically interchangeable with, and be more accurately made than, a conventional screen cylinder.
Additionally, all embodiments may make the practical use of other, novel thin screenplates. For example, a screenplate requiring very fine slots for the mainline screening of papermaking pulp can be made more precisely and cheaply from thin compared with conventional thick material. Further, for many applications thin screenplates may enable economical use of more wear resistant material which is expensive and/or difficult to manufacture from thick plate. Furthermore, for screening operations in which unconventional shape, orientation and/or pattern of apertures may be required, a thin screenplate permits economical machining by ECM and EDM techniques, and also facilitates economical three dimensional press forming when an irregular surface is required.
Having described our invention in terms of several embodiments above we do not wish to be limited in the scope of our invention except as claimed. | A support structure for thin screenplates utilized for fine screens in Fibresaving applications for pulp fiber suspensions or the like wherein a support structure having a screen support in minimum screen contact positioned by a support reinforcement and positioning device, assembled to form an integral structure which reduces the stresses and deflections in the thin screenplates occurring in operation. | 3 |
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